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1 #
2 # (C) Copyright 2000 - 2013
3 # Wolfgang Denk, DENX Software Engineering, wd@denx.de.
4 #
5 # SPDX-License-Identifier: GPL-2.0+
6 #
7
8 Summary:
9 ========
10
11 This directory contains the source code for U-Boot, a boot loader for
12 Embedded boards based on PowerPC, ARM, MIPS and several other
13 processors, which can be installed in a boot ROM and used to
14 initialize and test the hardware or to download and run application
15 code.
16
17 The development of U-Boot is closely related to Linux: some parts of
18 the source code originate in the Linux source tree, we have some
19 header files in common, and special provision has been made to
20 support booting of Linux images.
21
22 Some attention has been paid to make this software easily
23 configurable and extendable. For instance, all monitor commands are
24 implemented with the same call interface, so that it's very easy to
25 add new commands. Also, instead of permanently adding rarely used
26 code (for instance hardware test utilities) to the monitor, you can
27 load and run it dynamically.
28
29
30 Status:
31 =======
32
33 In general, all boards for which a configuration option exists in the
34 Makefile have been tested to some extent and can be considered
35 "working". In fact, many of them are used in production systems.
36
37 In case of problems see the CHANGELOG file to find out who contributed
38 the specific port. In addition, there are various MAINTAINERS files
39 scattered throughout the U-Boot source identifying the people or
40 companies responsible for various boards and subsystems.
41
42 Note: As of August, 2010, there is no longer a CHANGELOG file in the
43 actual U-Boot source tree; however, it can be created dynamically
44 from the Git log using:
45
46 make CHANGELOG
47
48
49 Where to get help:
50 ==================
51
52 In case you have questions about, problems with or contributions for
53 U-Boot, you should send a message to the U-Boot mailing list at
54 <u-boot@lists.denx.de>. There is also an archive of previous traffic
55 on the mailing list - please search the archive before asking FAQ's.
56 Please see http://lists.denx.de/pipermail/u-boot and
57 http://dir.gmane.org/gmane.comp.boot-loaders.u-boot
58
59
60 Where to get source code:
61 =========================
62
63 The U-Boot source code is maintained in the Git repository at
64 git://www.denx.de/git/u-boot.git ; you can browse it online at
65 http://www.denx.de/cgi-bin/gitweb.cgi?p=u-boot.git;a=summary
66
67 The "snapshot" links on this page allow you to download tarballs of
68 any version you might be interested in. Official releases are also
69 available for FTP download from the ftp://ftp.denx.de/pub/u-boot/
70 directory.
71
72 Pre-built (and tested) images are available from
73 ftp://ftp.denx.de/pub/u-boot/images/
74
75
76 Where we come from:
77 ===================
78
79 - start from 8xxrom sources
80 - create PPCBoot project (http://sourceforge.net/projects/ppcboot)
81 - clean up code
82 - make it easier to add custom boards
83 - make it possible to add other [PowerPC] CPUs
84 - extend functions, especially:
85 * Provide extended interface to Linux boot loader
86 * S-Record download
87 * network boot
88 * PCMCIA / CompactFlash / ATA disk / SCSI ... boot
89 - create ARMBoot project (http://sourceforge.net/projects/armboot)
90 - add other CPU families (starting with ARM)
91 - create U-Boot project (http://sourceforge.net/projects/u-boot)
92 - current project page: see http://www.denx.de/wiki/U-Boot
93
94
95 Names and Spelling:
96 ===================
97
98 The "official" name of this project is "Das U-Boot". The spelling
99 "U-Boot" shall be used in all written text (documentation, comments
100 in source files etc.). Example:
101
102 This is the README file for the U-Boot project.
103
104 File names etc. shall be based on the string "u-boot". Examples:
105
106 include/asm-ppc/u-boot.h
107
108 #include <asm/u-boot.h>
109
110 Variable names, preprocessor constants etc. shall be either based on
111 the string "u_boot" or on "U_BOOT". Example:
112
113 U_BOOT_VERSION u_boot_logo
114 IH_OS_U_BOOT u_boot_hush_start
115
116
117 Versioning:
118 ===========
119
120 Starting with the release in October 2008, the names of the releases
121 were changed from numerical release numbers without deeper meaning
122 into a time stamp based numbering. Regular releases are identified by
123 names consisting of the calendar year and month of the release date.
124 Additional fields (if present) indicate release candidates or bug fix
125 releases in "stable" maintenance trees.
126
127 Examples:
128 U-Boot v2009.11 - Release November 2009
129 U-Boot v2009.11.1 - Release 1 in version November 2009 stable tree
130 U-Boot v2010.09-rc1 - Release candiate 1 for September 2010 release
131
132
133 Directory Hierarchy:
134 ====================
135
136 /arch Architecture specific files
137 /arc Files generic to ARC architecture
138 /arm Files generic to ARM architecture
139 /avr32 Files generic to AVR32 architecture
140 /blackfin Files generic to Analog Devices Blackfin architecture
141 /m68k Files generic to m68k architecture
142 /microblaze Files generic to microblaze architecture
143 /mips Files generic to MIPS architecture
144 /nds32 Files generic to NDS32 architecture
145 /nios2 Files generic to Altera NIOS2 architecture
146 /openrisc Files generic to OpenRISC architecture
147 /powerpc Files generic to PowerPC architecture
148 /sandbox Files generic to HW-independent "sandbox"
149 /sh Files generic to SH architecture
150 /sparc Files generic to SPARC architecture
151 /x86 Files generic to x86 architecture
152 /api Machine/arch independent API for external apps
153 /board Board dependent files
154 /cmd U-Boot commands functions
155 /common Misc architecture independent functions
156 /configs Board default configuration files
157 /disk Code for disk drive partition handling
158 /doc Documentation (don't expect too much)
159 /drivers Commonly used device drivers
160 /dts Contains Makefile for building internal U-Boot fdt.
161 /examples Example code for standalone applications, etc.
162 /fs Filesystem code (cramfs, ext2, jffs2, etc.)
163 /include Header Files
164 /lib Library routines generic to all architectures
165 /Licenses Various license files
166 /net Networking code
167 /post Power On Self Test
168 /scripts Various build scripts and Makefiles
169 /test Various unit test files
170 /tools Tools to build S-Record or U-Boot images, etc.
171
172 Software Configuration:
173 =======================
174
175 Configuration is usually done using C preprocessor defines; the
176 rationale behind that is to avoid dead code whenever possible.
177
178 There are two classes of configuration variables:
179
180 * Configuration _OPTIONS_:
181 These are selectable by the user and have names beginning with
182 "CONFIG_".
183
184 * Configuration _SETTINGS_:
185 These depend on the hardware etc. and should not be meddled with if
186 you don't know what you're doing; they have names beginning with
187 "CONFIG_SYS_".
188
189 Previously, all configuration was done by hand, which involved creating
190 symbolic links and editing configuration files manually. More recently,
191 U-Boot has added the Kbuild infrastructure used by the Linux kernel,
192 allowing you to use the "make menuconfig" command to configure your
193 build.
194
195
196 Selection of Processor Architecture and Board Type:
197 ---------------------------------------------------
198
199 For all supported boards there are ready-to-use default
200 configurations available; just type "make <board_name>_defconfig".
201
202 Example: For a TQM823L module type:
203
204 cd u-boot
205 make TQM823L_defconfig
206
207 Note: If you're looking for the default configuration file for a board
208 you're sure used to be there but is now missing, check the file
209 doc/README.scrapyard for a list of no longer supported boards.
210
211 Sandbox Environment:
212 --------------------
213
214 U-Boot can be built natively to run on a Linux host using the 'sandbox'
215 board. This allows feature development which is not board- or architecture-
216 specific to be undertaken on a native platform. The sandbox is also used to
217 run some of U-Boot's tests.
218
219 See board/sandbox/README.sandbox for more details.
220
221
222 Board Initialisation Flow:
223 --------------------------
224
225 This is the intended start-up flow for boards. This should apply for both
226 SPL and U-Boot proper (i.e. they both follow the same rules).
227
228 Note: "SPL" stands for "Secondary Program Loader," which is explained in
229 more detail later in this file.
230
231 At present, SPL mostly uses a separate code path, but the function names
232 and roles of each function are the same. Some boards or architectures
233 may not conform to this. At least most ARM boards which use
234 CONFIG_SPL_FRAMEWORK conform to this.
235
236 Execution typically starts with an architecture-specific (and possibly
237 CPU-specific) start.S file, such as:
238
239 - arch/arm/cpu/armv7/start.S
240 - arch/powerpc/cpu/mpc83xx/start.S
241 - arch/mips/cpu/start.S
242
243 and so on. From there, three functions are called; the purpose and
244 limitations of each of these functions are described below.
245
246 lowlevel_init():
247 - purpose: essential init to permit execution to reach board_init_f()
248 - no global_data or BSS
249 - there is no stack (ARMv7 may have one but it will soon be removed)
250 - must not set up SDRAM or use console
251 - must only do the bare minimum to allow execution to continue to
252 board_init_f()
253 - this is almost never needed
254 - return normally from this function
255
256 board_init_f():
257 - purpose: set up the machine ready for running board_init_r():
258 i.e. SDRAM and serial UART
259 - global_data is available
260 - stack is in SRAM
261 - BSS is not available, so you cannot use global/static variables,
262 only stack variables and global_data
263
264 Non-SPL-specific notes:
265 - dram_init() is called to set up DRAM. If already done in SPL this
266 can do nothing
267
268 SPL-specific notes:
269 - you can override the entire board_init_f() function with your own
270 version as needed.
271 - preloader_console_init() can be called here in extremis
272 - should set up SDRAM, and anything needed to make the UART work
273 - these is no need to clear BSS, it will be done by crt0.S
274 - must return normally from this function (don't call board_init_r()
275 directly)
276
277 Here the BSS is cleared. For SPL, if CONFIG_SPL_STACK_R is defined, then at
278 this point the stack and global_data are relocated to below
279 CONFIG_SPL_STACK_R_ADDR. For non-SPL, U-Boot is relocated to run at the top of
280 memory.
281
282 board_init_r():
283 - purpose: main execution, common code
284 - global_data is available
285 - SDRAM is available
286 - BSS is available, all static/global variables can be used
287 - execution eventually continues to main_loop()
288
289 Non-SPL-specific notes:
290 - U-Boot is relocated to the top of memory and is now running from
291 there.
292
293 SPL-specific notes:
294 - stack is optionally in SDRAM, if CONFIG_SPL_STACK_R is defined and
295 CONFIG_SPL_STACK_R_ADDR points into SDRAM
296 - preloader_console_init() can be called here - typically this is
297 done by defining CONFIG_SPL_BOARD_INIT and then supplying a
298 spl_board_init() function containing this call
299 - loads U-Boot or (in falcon mode) Linux
300
301
302
303 Configuration Options:
304 ----------------------
305
306 Configuration depends on the combination of board and CPU type; all
307 such information is kept in a configuration file
308 "include/configs/<board_name>.h".
309
310 Example: For a TQM823L module, all configuration settings are in
311 "include/configs/TQM823L.h".
312
313
314 Many of the options are named exactly as the corresponding Linux
315 kernel configuration options. The intention is to make it easier to
316 build a config tool - later.
317
318
319 The following options need to be configured:
320
321 - CPU Type: Define exactly one, e.g. CONFIG_MPC85XX.
322
323 - Board Type: Define exactly one, e.g. CONFIG_MPC8540ADS.
324
325 - CPU Daughterboard Type: (if CONFIG_ATSTK1000 is defined)
326 Define exactly one, e.g. CONFIG_ATSTK1002
327
328 - Marvell Family Member
329 CONFIG_SYS_MVFS - define it if you want to enable
330 multiple fs option at one time
331 for marvell soc family
332
333 - 8xx CPU Options: (if using an MPC8xx CPU)
334 CONFIG_8xx_GCLK_FREQ - deprecated: CPU clock if
335 get_gclk_freq() cannot work
336 e.g. if there is no 32KHz
337 reference PIT/RTC clock
338 CONFIG_8xx_OSCLK - PLL input clock (either EXTCLK
339 or XTAL/EXTAL)
340
341 - 859/866/885 CPU options: (if using a MPC859 or MPC866 or MPC885 CPU):
342 CONFIG_SYS_8xx_CPUCLK_MIN
343 CONFIG_SYS_8xx_CPUCLK_MAX
344 CONFIG_8xx_CPUCLK_DEFAULT
345 See doc/README.MPC866
346
347 CONFIG_SYS_MEASURE_CPUCLK
348
349 Define this to measure the actual CPU clock instead
350 of relying on the correctness of the configured
351 values. Mostly useful for board bringup to make sure
352 the PLL is locked at the intended frequency. Note
353 that this requires a (stable) reference clock (32 kHz
354 RTC clock or CONFIG_SYS_8XX_XIN)
355
356 CONFIG_SYS_DELAYED_ICACHE
357
358 Define this option if you want to enable the
359 ICache only when Code runs from RAM.
360
361 - 85xx CPU Options:
362 CONFIG_SYS_PPC64
363
364 Specifies that the core is a 64-bit PowerPC implementation (implements
365 the "64" category of the Power ISA). This is necessary for ePAPR
366 compliance, among other possible reasons.
367
368 CONFIG_SYS_FSL_TBCLK_DIV
369
370 Defines the core time base clock divider ratio compared to the
371 system clock. On most PQ3 devices this is 8, on newer QorIQ
372 devices it can be 16 or 32. The ratio varies from SoC to Soc.
373
374 CONFIG_SYS_FSL_PCIE_COMPAT
375
376 Defines the string to utilize when trying to match PCIe device
377 tree nodes for the given platform.
378
379 CONFIG_SYS_PPC_E500_DEBUG_TLB
380
381 Enables a temporary TLB entry to be used during boot to work
382 around limitations in e500v1 and e500v2 external debugger
383 support. This reduces the portions of the boot code where
384 breakpoints and single stepping do not work. The value of this
385 symbol should be set to the TLB1 entry to be used for this
386 purpose.
387
388 CONFIG_SYS_FSL_ERRATUM_A004510
389
390 Enables a workaround for erratum A004510. If set,
391 then CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV and
392 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY must be set.
393
394 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV
395 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV2 (optional)
396
397 Defines one or two SoC revisions (low 8 bits of SVR)
398 for which the A004510 workaround should be applied.
399
400 The rest of SVR is either not relevant to the decision
401 of whether the erratum is present (e.g. p2040 versus
402 p2041) or is implied by the build target, which controls
403 whether CONFIG_SYS_FSL_ERRATUM_A004510 is set.
404
405 See Freescale App Note 4493 for more information about
406 this erratum.
407
408 CONFIG_A003399_NOR_WORKAROUND
409 Enables a workaround for IFC erratum A003399. It is only
410 required during NOR boot.
411
412 CONFIG_A008044_WORKAROUND
413 Enables a workaround for T1040/T1042 erratum A008044. It is only
414 required during NAND boot and valid for Rev 1.0 SoC revision
415
416 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY
417
418 This is the value to write into CCSR offset 0x18600
419 according to the A004510 workaround.
420
421 CONFIG_SYS_FSL_DSP_DDR_ADDR
422 This value denotes start offset of DDR memory which is
423 connected exclusively to the DSP cores.
424
425 CONFIG_SYS_FSL_DSP_M2_RAM_ADDR
426 This value denotes start offset of M2 memory
427 which is directly connected to the DSP core.
428
429 CONFIG_SYS_FSL_DSP_M3_RAM_ADDR
430 This value denotes start offset of M3 memory which is directly
431 connected to the DSP core.
432
433 CONFIG_SYS_FSL_DSP_CCSRBAR_DEFAULT
434 This value denotes start offset of DSP CCSR space.
435
436 CONFIG_SYS_FSL_SINGLE_SOURCE_CLK
437 Single Source Clock is clocking mode present in some of FSL SoC's.
438 In this mode, a single differential clock is used to supply
439 clocks to the sysclock, ddrclock and usbclock.
440
441 CONFIG_SYS_CPC_REINIT_F
442 This CONFIG is defined when the CPC is configured as SRAM at the
443 time of U-Boot entry and is required to be re-initialized.
444
445 CONFIG_DEEP_SLEEP
446 Indicates this SoC supports deep sleep feature. If deep sleep is
447 supported, core will start to execute uboot when wakes up.
448
449 - Generic CPU options:
450 CONFIG_SYS_GENERIC_GLOBAL_DATA
451 Defines global data is initialized in generic board board_init_f().
452 If this macro is defined, global data is created and cleared in
453 generic board board_init_f(). Without this macro, architecture/board
454 should initialize global data before calling board_init_f().
455
456 CONFIG_SYS_BIG_ENDIAN, CONFIG_SYS_LITTLE_ENDIAN
457
458 Defines the endianess of the CPU. Implementation of those
459 values is arch specific.
460
461 CONFIG_SYS_FSL_DDR
462 Freescale DDR driver in use. This type of DDR controller is
463 found in mpc83xx, mpc85xx, mpc86xx as well as some ARM core
464 SoCs.
465
466 CONFIG_SYS_FSL_DDR_ADDR
467 Freescale DDR memory-mapped register base.
468
469 CONFIG_SYS_FSL_DDR_EMU
470 Specify emulator support for DDR. Some DDR features such as
471 deskew training are not available.
472
473 CONFIG_SYS_FSL_DDRC_GEN1
474 Freescale DDR1 controller.
475
476 CONFIG_SYS_FSL_DDRC_GEN2
477 Freescale DDR2 controller.
478
479 CONFIG_SYS_FSL_DDRC_GEN3
480 Freescale DDR3 controller.
481
482 CONFIG_SYS_FSL_DDRC_GEN4
483 Freescale DDR4 controller.
484
485 CONFIG_SYS_FSL_DDRC_ARM_GEN3
486 Freescale DDR3 controller for ARM-based SoCs.
487
488 CONFIG_SYS_FSL_DDR1
489 Board config to use DDR1. It can be enabled for SoCs with
490 Freescale DDR1 or DDR2 controllers, depending on the board
491 implemetation.
492
493 CONFIG_SYS_FSL_DDR2
494 Board config to use DDR2. It can be enabled for SoCs with
495 Freescale DDR2 or DDR3 controllers, depending on the board
496 implementation.
497
498 CONFIG_SYS_FSL_DDR3
499 Board config to use DDR3. It can be enabled for SoCs with
500 Freescale DDR3 or DDR3L controllers.
501
502 CONFIG_SYS_FSL_DDR3L
503 Board config to use DDR3L. It can be enabled for SoCs with
504 DDR3L controllers.
505
506 CONFIG_SYS_FSL_DDR4
507 Board config to use DDR4. It can be enabled for SoCs with
508 DDR4 controllers.
509
510 CONFIG_SYS_FSL_IFC_BE
511 Defines the IFC controller register space as Big Endian
512
513 CONFIG_SYS_FSL_IFC_LE
514 Defines the IFC controller register space as Little Endian
515
516 CONFIG_SYS_FSL_PBL_PBI
517 It enables addition of RCW (Power on reset configuration) in built image.
518 Please refer doc/README.pblimage for more details
519
520 CONFIG_SYS_FSL_PBL_RCW
521 It adds PBI(pre-boot instructions) commands in u-boot build image.
522 PBI commands can be used to configure SoC before it starts the execution.
523 Please refer doc/README.pblimage for more details
524
525 CONFIG_SPL_FSL_PBL
526 It adds a target to create boot binary having SPL binary in PBI format
527 concatenated with u-boot binary.
528
529 CONFIG_SYS_FSL_DDR_BE
530 Defines the DDR controller register space as Big Endian
531
532 CONFIG_SYS_FSL_DDR_LE
533 Defines the DDR controller register space as Little Endian
534
535 CONFIG_SYS_FSL_DDR_SDRAM_BASE_PHY
536 Physical address from the view of DDR controllers. It is the
537 same as CONFIG_SYS_DDR_SDRAM_BASE for all Power SoCs. But
538 it could be different for ARM SoCs.
539
540 CONFIG_SYS_FSL_DDR_INTLV_256B
541 DDR controller interleaving on 256-byte. This is a special
542 interleaving mode, handled by Dickens for Freescale layerscape
543 SoCs with ARM core.
544
545 CONFIG_SYS_FSL_DDR_MAIN_NUM_CTRLS
546 Number of controllers used as main memory.
547
548 CONFIG_SYS_FSL_OTHER_DDR_NUM_CTRLS
549 Number of controllers used for other than main memory.
550
551 CONFIG_SYS_FSL_HAS_DP_DDR
552 Defines the SoC has DP-DDR used for DPAA.
553
554 CONFIG_SYS_FSL_SEC_BE
555 Defines the SEC controller register space as Big Endian
556
557 CONFIG_SYS_FSL_SEC_LE
558 Defines the SEC controller register space as Little Endian
559
560 - MIPS CPU options:
561 CONFIG_SYS_INIT_SP_OFFSET
562
563 Offset relative to CONFIG_SYS_SDRAM_BASE for initial stack
564 pointer. This is needed for the temporary stack before
565 relocation.
566
567 CONFIG_SYS_MIPS_CACHE_MODE
568
569 Cache operation mode for the MIPS CPU.
570 See also arch/mips/include/asm/mipsregs.h.
571 Possible values are:
572 CONF_CM_CACHABLE_NO_WA
573 CONF_CM_CACHABLE_WA
574 CONF_CM_UNCACHED
575 CONF_CM_CACHABLE_NONCOHERENT
576 CONF_CM_CACHABLE_CE
577 CONF_CM_CACHABLE_COW
578 CONF_CM_CACHABLE_CUW
579 CONF_CM_CACHABLE_ACCELERATED
580
581 CONFIG_SYS_XWAY_EBU_BOOTCFG
582
583 Special option for Lantiq XWAY SoCs for booting from NOR flash.
584 See also arch/mips/cpu/mips32/start.S.
585
586 CONFIG_XWAY_SWAP_BYTES
587
588 Enable compilation of tools/xway-swap-bytes needed for Lantiq
589 XWAY SoCs for booting from NOR flash. The U-Boot image needs to
590 be swapped if a flash programmer is used.
591
592 - ARM options:
593 CONFIG_SYS_EXCEPTION_VECTORS_HIGH
594
595 Select high exception vectors of the ARM core, e.g., do not
596 clear the V bit of the c1 register of CP15.
597
598 CONFIG_SYS_THUMB_BUILD
599
600 Use this flag to build U-Boot using the Thumb instruction
601 set for ARM architectures. Thumb instruction set provides
602 better code density. For ARM architectures that support
603 Thumb2 this flag will result in Thumb2 code generated by
604 GCC.
605
606 CONFIG_ARM_ERRATA_716044
607 CONFIG_ARM_ERRATA_742230
608 CONFIG_ARM_ERRATA_743622
609 CONFIG_ARM_ERRATA_751472
610 CONFIG_ARM_ERRATA_761320
611 CONFIG_ARM_ERRATA_773022
612 CONFIG_ARM_ERRATA_774769
613 CONFIG_ARM_ERRATA_794072
614
615 If set, the workarounds for these ARM errata are applied early
616 during U-Boot startup. Note that these options force the
617 workarounds to be applied; no CPU-type/version detection
618 exists, unlike the similar options in the Linux kernel. Do not
619 set these options unless they apply!
620
621 COUNTER_FREQUENCY
622 Generic timer clock source frequency.
623
624 COUNTER_FREQUENCY_REAL
625 Generic timer clock source frequency if the real clock is
626 different from COUNTER_FREQUENCY, and can only be determined
627 at run time.
628
629 NOTE: The following can be machine specific errata. These
630 do have ability to provide rudimentary version and machine
631 specific checks, but expect no product checks.
632 CONFIG_ARM_ERRATA_430973
633 CONFIG_ARM_ERRATA_454179
634 CONFIG_ARM_ERRATA_621766
635 CONFIG_ARM_ERRATA_798870
636 CONFIG_ARM_ERRATA_801819
637
638 - Tegra SoC options:
639 CONFIG_TEGRA_SUPPORT_NON_SECURE
640
641 Support executing U-Boot in non-secure (NS) mode. Certain
642 impossible actions will be skipped if the CPU is in NS mode,
643 such as ARM architectural timer initialization.
644
645 - Linux Kernel Interface:
646 CONFIG_CLOCKS_IN_MHZ
647
648 U-Boot stores all clock information in Hz
649 internally. For binary compatibility with older Linux
650 kernels (which expect the clocks passed in the
651 bd_info data to be in MHz) the environment variable
652 "clocks_in_mhz" can be defined so that U-Boot
653 converts clock data to MHZ before passing it to the
654 Linux kernel.
655 When CONFIG_CLOCKS_IN_MHZ is defined, a definition of
656 "clocks_in_mhz=1" is automatically included in the
657 default environment.
658
659 CONFIG_MEMSIZE_IN_BYTES [relevant for MIPS only]
660
661 When transferring memsize parameter to Linux, some versions
662 expect it to be in bytes, others in MB.
663 Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes.
664
665 CONFIG_OF_LIBFDT
666
667 New kernel versions are expecting firmware settings to be
668 passed using flattened device trees (based on open firmware
669 concepts).
670
671 CONFIG_OF_LIBFDT
672 * New libfdt-based support
673 * Adds the "fdt" command
674 * The bootm command automatically updates the fdt
675
676 OF_CPU - The proper name of the cpus node (only required for
677 MPC512X and MPC5xxx based boards).
678 OF_SOC - The proper name of the soc node (only required for
679 MPC512X and MPC5xxx based boards).
680 OF_TBCLK - The timebase frequency.
681 OF_STDOUT_PATH - The path to the console device
682
683 boards with QUICC Engines require OF_QE to set UCC MAC
684 addresses
685
686 CONFIG_OF_BOARD_SETUP
687
688 Board code has addition modification that it wants to make
689 to the flat device tree before handing it off to the kernel
690
691 CONFIG_OF_SYSTEM_SETUP
692
693 Other code has addition modification that it wants to make
694 to the flat device tree before handing it off to the kernel.
695 This causes ft_system_setup() to be called before booting
696 the kernel.
697
698 CONFIG_OF_IDE_FIXUP
699
700 U-Boot can detect if an IDE device is present or not.
701 If not, and this new config option is activated, U-Boot
702 removes the ATA node from the DTS before booting Linux,
703 so the Linux IDE driver does not probe the device and
704 crash. This is needed for buggy hardware (uc101) where
705 no pull down resistor is connected to the signal IDE5V_DD7.
706
707 CONFIG_MACH_TYPE [relevant for ARM only][mandatory]
708
709 This setting is mandatory for all boards that have only one
710 machine type and must be used to specify the machine type
711 number as it appears in the ARM machine registry
712 (see http://www.arm.linux.org.uk/developer/machines/).
713 Only boards that have multiple machine types supported
714 in a single configuration file and the machine type is
715 runtime discoverable, do not have to use this setting.
716
717 - vxWorks boot parameters:
718
719 bootvx constructs a valid bootline using the following
720 environments variables: bootdev, bootfile, ipaddr, netmask,
721 serverip, gatewayip, hostname, othbootargs.
722 It loads the vxWorks image pointed bootfile.
723
724 Note: If a "bootargs" environment is defined, it will overwride
725 the defaults discussed just above.
726
727 - Cache Configuration:
728 CONFIG_SYS_ICACHE_OFF - Do not enable instruction cache in U-Boot
729 CONFIG_SYS_DCACHE_OFF - Do not enable data cache in U-Boot
730 CONFIG_SYS_L2CACHE_OFF- Do not enable L2 cache in U-Boot
731
732 - Cache Configuration for ARM:
733 CONFIG_SYS_L2_PL310 - Enable support for ARM PL310 L2 cache
734 controller
735 CONFIG_SYS_PL310_BASE - Physical base address of PL310
736 controller register space
737
738 - Serial Ports:
739 CONFIG_PL010_SERIAL
740
741 Define this if you want support for Amba PrimeCell PL010 UARTs.
742
743 CONFIG_PL011_SERIAL
744
745 Define this if you want support for Amba PrimeCell PL011 UARTs.
746
747 CONFIG_PL011_CLOCK
748
749 If you have Amba PrimeCell PL011 UARTs, set this variable to
750 the clock speed of the UARTs.
751
752 CONFIG_PL01x_PORTS
753
754 If you have Amba PrimeCell PL010 or PL011 UARTs on your board,
755 define this to a list of base addresses for each (supported)
756 port. See e.g. include/configs/versatile.h
757
758 CONFIG_SERIAL_HW_FLOW_CONTROL
759
760 Define this variable to enable hw flow control in serial driver.
761 Current user of this option is drivers/serial/nsl16550.c driver
762
763 - Console Interface:
764 Depending on board, define exactly one serial port
765 (like CONFIG_8xx_CONS_SMC1, CONFIG_8xx_CONS_SMC2,
766 CONFIG_8xx_CONS_SCC1, ...), or switch off the serial
767 console by defining CONFIG_8xx_CONS_NONE
768
769 Note: if CONFIG_8xx_CONS_NONE is defined, the serial
770 port routines must be defined elsewhere
771 (i.e. serial_init(), serial_getc(), ...)
772
773 CONFIG_CFB_CONSOLE
774 Enables console device for a color framebuffer. Needs following
775 defines (cf. smiLynxEM, i8042)
776 VIDEO_FB_LITTLE_ENDIAN graphic memory organisation
777 (default big endian)
778 VIDEO_HW_RECTFILL graphic chip supports
779 rectangle fill
780 (cf. smiLynxEM)
781 VIDEO_HW_BITBLT graphic chip supports
782 bit-blit (cf. smiLynxEM)
783 VIDEO_VISIBLE_COLS visible pixel columns
784 (cols=pitch)
785 VIDEO_VISIBLE_ROWS visible pixel rows
786 VIDEO_PIXEL_SIZE bytes per pixel
787 VIDEO_DATA_FORMAT graphic data format
788 (0-5, cf. cfb_console.c)
789 VIDEO_FB_ADRS framebuffer address
790 VIDEO_KBD_INIT_FCT keyboard int fct
791 (i.e. rx51_kp_init())
792 VIDEO_TSTC_FCT test char fct
793 (i.e. rx51_kp_tstc)
794 VIDEO_GETC_FCT get char fct
795 (i.e. rx51_kp_getc)
796 CONFIG_VIDEO_LOGO display Linux logo in
797 upper left corner
798 CONFIG_VIDEO_BMP_LOGO use bmp_logo.h instead of
799 linux_logo.h for logo.
800 Requires CONFIG_VIDEO_LOGO
801 CONFIG_CONSOLE_EXTRA_INFO
802 additional board info beside
803 the logo
804 CONFIG_HIDE_LOGO_VERSION
805 do not display bootloader
806 version string
807
808 When CONFIG_CFB_CONSOLE_ANSI is defined, console will support
809 a limited number of ANSI escape sequences (cursor control,
810 erase functions and limited graphics rendition control).
811
812 When CONFIG_CFB_CONSOLE is defined, video console is
813 default i/o. Serial console can be forced with
814 environment 'console=serial'.
815
816 CONFIG_SYS_CONSOLE_BG_COL: define the backgroundcolor, default
817 is 0x00.
818 CONFIG_SYS_CONSOLE_FG_COL: define the foregroundcolor, default
819 is 0xa0.
820
821 - Console Baudrate:
822 CONFIG_BAUDRATE - in bps
823 Select one of the baudrates listed in
824 CONFIG_SYS_BAUDRATE_TABLE, see below.
825 CONFIG_SYS_BRGCLK_PRESCALE, baudrate prescale
826
827 - Console Rx buffer length
828 With CONFIG_SYS_SMC_RXBUFLEN it is possible to define
829 the maximum receive buffer length for the SMC.
830 This option is actual only for 82xx and 8xx possible.
831 If using CONFIG_SYS_SMC_RXBUFLEN also CONFIG_SYS_MAXIDLE
832 must be defined, to setup the maximum idle timeout for
833 the SMC.
834
835 - Autoboot Command:
836 CONFIG_BOOTCOMMAND
837 Only needed when CONFIG_BOOTDELAY is enabled;
838 define a command string that is automatically executed
839 when no character is read on the console interface
840 within "Boot Delay" after reset.
841
842 CONFIG_BOOTARGS
843 This can be used to pass arguments to the bootm
844 command. The value of CONFIG_BOOTARGS goes into the
845 environment value "bootargs".
846
847 CONFIG_RAMBOOT and CONFIG_NFSBOOT
848 The value of these goes into the environment as
849 "ramboot" and "nfsboot" respectively, and can be used
850 as a convenience, when switching between booting from
851 RAM and NFS.
852
853 - Bootcount:
854 CONFIG_BOOTCOUNT_LIMIT
855 Implements a mechanism for detecting a repeating reboot
856 cycle, see:
857 http://www.denx.de/wiki/view/DULG/UBootBootCountLimit
858
859 CONFIG_BOOTCOUNT_ENV
860 If no softreset save registers are found on the hardware
861 "bootcount" is stored in the environment. To prevent a
862 saveenv on all reboots, the environment variable
863 "upgrade_available" is used. If "upgrade_available" is
864 0, "bootcount" is always 0, if "upgrade_available" is
865 1 "bootcount" is incremented in the environment.
866 So the Userspace Applikation must set the "upgrade_available"
867 and "bootcount" variable to 0, if a boot was successfully.
868
869 - Pre-Boot Commands:
870 CONFIG_PREBOOT
871
872 When this option is #defined, the existence of the
873 environment variable "preboot" will be checked
874 immediately before starting the CONFIG_BOOTDELAY
875 countdown and/or running the auto-boot command resp.
876 entering interactive mode.
877
878 This feature is especially useful when "preboot" is
879 automatically generated or modified. For an example
880 see the LWMON board specific code: here "preboot" is
881 modified when the user holds down a certain
882 combination of keys on the (special) keyboard when
883 booting the systems
884
885 - Serial Download Echo Mode:
886 CONFIG_LOADS_ECHO
887 If defined to 1, all characters received during a
888 serial download (using the "loads" command) are
889 echoed back. This might be needed by some terminal
890 emulations (like "cu"), but may as well just take
891 time on others. This setting #define's the initial
892 value of the "loads_echo" environment variable.
893
894 - Kgdb Serial Baudrate: (if CONFIG_CMD_KGDB is defined)
895 CONFIG_KGDB_BAUDRATE
896 Select one of the baudrates listed in
897 CONFIG_SYS_BAUDRATE_TABLE, see below.
898
899 - Monitor Functions:
900 Monitor commands can be included or excluded
901 from the build by using the #include files
902 <config_cmd_all.h> and #undef'ing unwanted
903 commands, or adding #define's for wanted commands.
904
905 The default command configuration includes all commands
906 except those marked below with a "*".
907
908 CONFIG_CMD_AES AES 128 CBC encrypt/decrypt
909 CONFIG_CMD_ASKENV * ask for env variable
910 CONFIG_CMD_BDI bdinfo
911 CONFIG_CMD_BEDBUG * Include BedBug Debugger
912 CONFIG_CMD_BMP * BMP support
913 CONFIG_CMD_BSP * Board specific commands
914 CONFIG_CMD_BOOTD bootd
915 CONFIG_CMD_BOOTI * ARM64 Linux kernel Image support
916 CONFIG_CMD_CACHE * icache, dcache
917 CONFIG_CMD_CLK * clock command support
918 CONFIG_CMD_CONSOLE coninfo
919 CONFIG_CMD_CRC32 * crc32
920 CONFIG_CMD_DATE * support for RTC, date/time...
921 CONFIG_CMD_DHCP * DHCP support
922 CONFIG_CMD_DIAG * Diagnostics
923 CONFIG_CMD_DS4510 * ds4510 I2C gpio commands
924 CONFIG_CMD_DS4510_INFO * ds4510 I2C info command
925 CONFIG_CMD_DS4510_MEM * ds4510 I2C eeprom/sram commansd
926 CONFIG_CMD_DS4510_RST * ds4510 I2C rst command
927 CONFIG_CMD_DTT * Digital Therm and Thermostat
928 CONFIG_CMD_ECHO echo arguments
929 CONFIG_CMD_EDITENV edit env variable
930 CONFIG_CMD_EEPROM * EEPROM read/write support
931 CONFIG_CMD_EEPROM_LAYOUT* EEPROM layout aware commands
932 CONFIG_CMD_ELF * bootelf, bootvx
933 CONFIG_CMD_ENV_CALLBACK * display details about env callbacks
934 CONFIG_CMD_ENV_FLAGS * display details about env flags
935 CONFIG_CMD_ENV_EXISTS * check existence of env variable
936 CONFIG_CMD_EXPORTENV * export the environment
937 CONFIG_CMD_EXT2 * ext2 command support
938 CONFIG_CMD_EXT4 * ext4 command support
939 CONFIG_CMD_FS_GENERIC * filesystem commands (e.g. load, ls)
940 that work for multiple fs types
941 CONFIG_CMD_FS_UUID * Look up a filesystem UUID
942 CONFIG_CMD_SAVEENV saveenv
943 CONFIG_CMD_FDC * Floppy Disk Support
944 CONFIG_CMD_FAT * FAT command support
945 CONFIG_CMD_FLASH flinfo, erase, protect
946 CONFIG_CMD_FPGA FPGA device initialization support
947 CONFIG_CMD_FUSE * Device fuse support
948 CONFIG_CMD_GETTIME * Get time since boot
949 CONFIG_CMD_GO * the 'go' command (exec code)
950 CONFIG_CMD_GREPENV * search environment
951 CONFIG_CMD_HASH * calculate hash / digest
952 CONFIG_CMD_I2C * I2C serial bus support
953 CONFIG_CMD_IDE * IDE harddisk support
954 CONFIG_CMD_IMI iminfo
955 CONFIG_CMD_IMLS List all images found in NOR flash
956 CONFIG_CMD_IMLS_NAND * List all images found in NAND flash
957 CONFIG_CMD_IMMAP * IMMR dump support
958 CONFIG_CMD_IOTRACE * I/O tracing for debugging
959 CONFIG_CMD_IMPORTENV * import an environment
960 CONFIG_CMD_INI * import data from an ini file into the env
961 CONFIG_CMD_IRQ * irqinfo
962 CONFIG_CMD_ITEST Integer/string test of 2 values
963 CONFIG_CMD_JFFS2 * JFFS2 Support
964 CONFIG_CMD_KGDB * kgdb
965 CONFIG_CMD_LDRINFO * ldrinfo (display Blackfin loader)
966 CONFIG_CMD_LINK_LOCAL * link-local IP address auto-configuration
967 (169.254.*.*)
968 CONFIG_CMD_LOADB loadb
969 CONFIG_CMD_LOADS loads
970 CONFIG_CMD_MD5SUM * print md5 message digest
971 (requires CONFIG_CMD_MEMORY and CONFIG_MD5)
972 CONFIG_CMD_MEMINFO * Display detailed memory information
973 CONFIG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base,
974 loop, loopw
975 CONFIG_CMD_MEMTEST * mtest
976 CONFIG_CMD_MISC Misc functions like sleep etc
977 CONFIG_CMD_MMC * MMC memory mapped support
978 CONFIG_CMD_MII * MII utility commands
979 CONFIG_CMD_MTDPARTS * MTD partition support
980 CONFIG_CMD_NAND * NAND support
981 CONFIG_CMD_NET bootp, tftpboot, rarpboot
982 CONFIG_CMD_NFS NFS support
983 CONFIG_CMD_PCA953X * PCA953x I2C gpio commands
984 CONFIG_CMD_PCA953X_INFO * PCA953x I2C gpio info command
985 CONFIG_CMD_PCI * pciinfo
986 CONFIG_CMD_PCMCIA * PCMCIA support
987 CONFIG_CMD_PING * send ICMP ECHO_REQUEST to network
988 host
989 CONFIG_CMD_PORTIO * Port I/O
990 CONFIG_CMD_READ * Read raw data from partition
991 CONFIG_CMD_REGINFO * Register dump
992 CONFIG_CMD_RUN run command in env variable
993 CONFIG_CMD_SANDBOX * sb command to access sandbox features
994 CONFIG_CMD_SAVES * save S record dump
995 CONFIG_SCSI * SCSI Support
996 CONFIG_CMD_SDRAM * print SDRAM configuration information
997 (requires CONFIG_CMD_I2C)
998 CONFIG_CMD_SETGETDCR Support for DCR Register access
999 (4xx only)
1000 CONFIG_CMD_SF * Read/write/erase SPI NOR flash
1001 CONFIG_CMD_SHA1SUM * print sha1 memory digest
1002 (requires CONFIG_CMD_MEMORY)
1003 CONFIG_CMD_SOFTSWITCH * Soft switch setting command for BF60x
1004 CONFIG_CMD_SOURCE "source" command Support
1005 CONFIG_CMD_SPI * SPI serial bus support
1006 CONFIG_CMD_TFTPSRV * TFTP transfer in server mode
1007 CONFIG_CMD_TFTPPUT * TFTP put command (upload)
1008 CONFIG_CMD_TIME * run command and report execution time (ARM specific)
1009 CONFIG_CMD_TIMER * access to the system tick timer
1010 CONFIG_CMD_USB * USB support
1011 CONFIG_CMD_CDP * Cisco Discover Protocol support
1012 CONFIG_CMD_MFSL * Microblaze FSL support
1013 CONFIG_CMD_XIMG Load part of Multi Image
1014 CONFIG_CMD_UUID * Generate random UUID or GUID string
1015
1016 EXAMPLE: If you want all functions except of network
1017 support you can write:
1018
1019 #include "config_cmd_all.h"
1020 #undef CONFIG_CMD_NET
1021
1022 Other Commands:
1023 fdt (flattened device tree) command: CONFIG_OF_LIBFDT
1024
1025 Note: Don't enable the "icache" and "dcache" commands
1026 (configuration option CONFIG_CMD_CACHE) unless you know
1027 what you (and your U-Boot users) are doing. Data
1028 cache cannot be enabled on systems like the 8xx or
1029 8260 (where accesses to the IMMR region must be
1030 uncached), and it cannot be disabled on all other
1031 systems where we (mis-) use the data cache to hold an
1032 initial stack and some data.
1033
1034
1035 XXX - this list needs to get updated!
1036
1037 - Removal of commands
1038 If no commands are needed to boot, you can disable
1039 CONFIG_CMDLINE to remove them. In this case, the command line
1040 will not be available, and when U-Boot wants to execute the
1041 boot command (on start-up) it will call board_run_command()
1042 instead. This can reduce image size significantly for very
1043 simple boot procedures.
1044
1045 - Regular expression support:
1046 CONFIG_REGEX
1047 If this variable is defined, U-Boot is linked against
1048 the SLRE (Super Light Regular Expression) library,
1049 which adds regex support to some commands, as for
1050 example "env grep" and "setexpr".
1051
1052 - Device tree:
1053 CONFIG_OF_CONTROL
1054 If this variable is defined, U-Boot will use a device tree
1055 to configure its devices, instead of relying on statically
1056 compiled #defines in the board file. This option is
1057 experimental and only available on a few boards. The device
1058 tree is available in the global data as gd->fdt_blob.
1059
1060 U-Boot needs to get its device tree from somewhere. This can
1061 be done using one of the two options below:
1062
1063 CONFIG_OF_EMBED
1064 If this variable is defined, U-Boot will embed a device tree
1065 binary in its image. This device tree file should be in the
1066 board directory and called <soc>-<board>.dts. The binary file
1067 is then picked up in board_init_f() and made available through
1068 the global data structure as gd->blob.
1069
1070 CONFIG_OF_SEPARATE
1071 If this variable is defined, U-Boot will build a device tree
1072 binary. It will be called u-boot.dtb. Architecture-specific
1073 code will locate it at run-time. Generally this works by:
1074
1075 cat u-boot.bin u-boot.dtb >image.bin
1076
1077 and in fact, U-Boot does this for you, creating a file called
1078 u-boot-dtb.bin which is useful in the common case. You can
1079 still use the individual files if you need something more
1080 exotic.
1081
1082 - Watchdog:
1083 CONFIG_WATCHDOG
1084 If this variable is defined, it enables watchdog
1085 support for the SoC. There must be support in the SoC
1086 specific code for a watchdog. For the 8xx and 8260
1087 CPUs, the SIU Watchdog feature is enabled in the SYPCR
1088 register. When supported for a specific SoC is
1089 available, then no further board specific code should
1090 be needed to use it.
1091
1092 CONFIG_HW_WATCHDOG
1093 When using a watchdog circuitry external to the used
1094 SoC, then define this variable and provide board
1095 specific code for the "hw_watchdog_reset" function.
1096
1097 CONFIG_AT91_HW_WDT_TIMEOUT
1098 specify the timeout in seconds. default 2 seconds.
1099
1100 - U-Boot Version:
1101 CONFIG_VERSION_VARIABLE
1102 If this variable is defined, an environment variable
1103 named "ver" is created by U-Boot showing the U-Boot
1104 version as printed by the "version" command.
1105 Any change to this variable will be reverted at the
1106 next reset.
1107
1108 - Real-Time Clock:
1109
1110 When CONFIG_CMD_DATE is selected, the type of the RTC
1111 has to be selected, too. Define exactly one of the
1112 following options:
1113
1114 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx
1115 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC
1116 CONFIG_RTC_MC13XXX - use MC13783 or MC13892 RTC
1117 CONFIG_RTC_MC146818 - use MC146818 RTC
1118 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC
1119 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC
1120 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC
1121 CONFIG_RTC_DS1339 - use Maxim, Inc. DS1339 RTC
1122 CONFIG_RTC_DS164x - use Dallas DS164x RTC
1123 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC
1124 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC
1125 CONFIG_SYS_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337
1126 CONFIG_SYS_RV3029_TCR - enable trickle charger on
1127 RV3029 RTC.
1128
1129 Note that if the RTC uses I2C, then the I2C interface
1130 must also be configured. See I2C Support, below.
1131
1132 - GPIO Support:
1133 CONFIG_PCA953X - use NXP's PCA953X series I2C GPIO
1134
1135 The CONFIG_SYS_I2C_PCA953X_WIDTH option specifies a list of
1136 chip-ngpio pairs that tell the PCA953X driver the number of
1137 pins supported by a particular chip.
1138
1139 Note that if the GPIO device uses I2C, then the I2C interface
1140 must also be configured. See I2C Support, below.
1141
1142 - I/O tracing:
1143 When CONFIG_IO_TRACE is selected, U-Boot intercepts all I/O
1144 accesses and can checksum them or write a list of them out
1145 to memory. See the 'iotrace' command for details. This is
1146 useful for testing device drivers since it can confirm that
1147 the driver behaves the same way before and after a code
1148 change. Currently this is supported on sandbox and arm. To
1149 add support for your architecture, add '#include <iotrace.h>'
1150 to the bottom of arch/<arch>/include/asm/io.h and test.
1151
1152 Example output from the 'iotrace stats' command is below.
1153 Note that if the trace buffer is exhausted, the checksum will
1154 still continue to operate.
1155
1156 iotrace is enabled
1157 Start: 10000000 (buffer start address)
1158 Size: 00010000 (buffer size)
1159 Offset: 00000120 (current buffer offset)
1160 Output: 10000120 (start + offset)
1161 Count: 00000018 (number of trace records)
1162 CRC32: 9526fb66 (CRC32 of all trace records)
1163
1164 - Timestamp Support:
1165
1166 When CONFIG_TIMESTAMP is selected, the timestamp
1167 (date and time) of an image is printed by image
1168 commands like bootm or iminfo. This option is
1169 automatically enabled when you select CONFIG_CMD_DATE .
1170
1171 - Partition Labels (disklabels) Supported:
1172 Zero or more of the following:
1173 CONFIG_MAC_PARTITION Apple's MacOS partition table.
1174 CONFIG_DOS_PARTITION MS Dos partition table, traditional on the
1175 Intel architecture, USB sticks, etc.
1176 CONFIG_ISO_PARTITION ISO partition table, used on CDROM etc.
1177 CONFIG_EFI_PARTITION GPT partition table, common when EFI is the
1178 bootloader. Note 2TB partition limit; see
1179 disk/part_efi.c
1180 CONFIG_MTD_PARTITIONS Memory Technology Device partition table.
1181
1182 If IDE or SCSI support is enabled (CONFIG_CMD_IDE or
1183 CONFIG_SCSI) you must configure support for at
1184 least one non-MTD partition type as well.
1185
1186 - IDE Reset method:
1187 CONFIG_IDE_RESET_ROUTINE - this is defined in several
1188 board configurations files but used nowhere!
1189
1190 CONFIG_IDE_RESET - is this is defined, IDE Reset will
1191 be performed by calling the function
1192 ide_set_reset(int reset)
1193 which has to be defined in a board specific file
1194
1195 - ATAPI Support:
1196 CONFIG_ATAPI
1197
1198 Set this to enable ATAPI support.
1199
1200 - LBA48 Support
1201 CONFIG_LBA48
1202
1203 Set this to enable support for disks larger than 137GB
1204 Also look at CONFIG_SYS_64BIT_LBA.
1205 Whithout these , LBA48 support uses 32bit variables and will 'only'
1206 support disks up to 2.1TB.
1207
1208 CONFIG_SYS_64BIT_LBA:
1209 When enabled, makes the IDE subsystem use 64bit sector addresses.
1210 Default is 32bit.
1211
1212 - SCSI Support:
1213 At the moment only there is only support for the
1214 SYM53C8XX SCSI controller; define
1215 CONFIG_SCSI_SYM53C8XX to enable it.
1216
1217 CONFIG_SYS_SCSI_MAX_LUN [8], CONFIG_SYS_SCSI_MAX_SCSI_ID [7] and
1218 CONFIG_SYS_SCSI_MAX_DEVICE [CONFIG_SYS_SCSI_MAX_SCSI_ID *
1219 CONFIG_SYS_SCSI_MAX_LUN] can be adjusted to define the
1220 maximum numbers of LUNs, SCSI ID's and target
1221 devices.
1222 CONFIG_SYS_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz)
1223
1224 The environment variable 'scsidevs' is set to the number of
1225 SCSI devices found during the last scan.
1226
1227 - NETWORK Support (PCI):
1228 CONFIG_E1000
1229 Support for Intel 8254x/8257x gigabit chips.
1230
1231 CONFIG_E1000_SPI
1232 Utility code for direct access to the SPI bus on Intel 8257x.
1233 This does not do anything useful unless you set at least one
1234 of CONFIG_CMD_E1000 or CONFIG_E1000_SPI_GENERIC.
1235
1236 CONFIG_E1000_SPI_GENERIC
1237 Allow generic access to the SPI bus on the Intel 8257x, for
1238 example with the "sspi" command.
1239
1240 CONFIG_CMD_E1000
1241 Management command for E1000 devices. When used on devices
1242 with SPI support you can reprogram the EEPROM from U-Boot.
1243
1244 CONFIG_EEPRO100
1245 Support for Intel 82557/82559/82559ER chips.
1246 Optional CONFIG_EEPRO100_SROM_WRITE enables EEPROM
1247 write routine for first time initialisation.
1248
1249 CONFIG_TULIP
1250 Support for Digital 2114x chips.
1251 Optional CONFIG_TULIP_SELECT_MEDIA for board specific
1252 modem chip initialisation (KS8761/QS6611).
1253
1254 CONFIG_NATSEMI
1255 Support for National dp83815 chips.
1256
1257 CONFIG_NS8382X
1258 Support for National dp8382[01] gigabit chips.
1259
1260 - NETWORK Support (other):
1261
1262 CONFIG_DRIVER_AT91EMAC
1263 Support for AT91RM9200 EMAC.
1264
1265 CONFIG_RMII
1266 Define this to use reduced MII inteface
1267
1268 CONFIG_DRIVER_AT91EMAC_QUIET
1269 If this defined, the driver is quiet.
1270 The driver doen't show link status messages.
1271
1272 CONFIG_CALXEDA_XGMAC
1273 Support for the Calxeda XGMAC device
1274
1275 CONFIG_LAN91C96
1276 Support for SMSC's LAN91C96 chips.
1277
1278 CONFIG_LAN91C96_USE_32_BIT
1279 Define this to enable 32 bit addressing
1280
1281 CONFIG_SMC91111
1282 Support for SMSC's LAN91C111 chip
1283
1284 CONFIG_SMC91111_BASE
1285 Define this to hold the physical address
1286 of the device (I/O space)
1287
1288 CONFIG_SMC_USE_32_BIT
1289 Define this if data bus is 32 bits
1290
1291 CONFIG_SMC_USE_IOFUNCS
1292 Define this to use i/o functions instead of macros
1293 (some hardware wont work with macros)
1294
1295 CONFIG_DRIVER_TI_EMAC
1296 Support for davinci emac
1297
1298 CONFIG_SYS_DAVINCI_EMAC_PHY_COUNT
1299 Define this if you have more then 3 PHYs.
1300
1301 CONFIG_FTGMAC100
1302 Support for Faraday's FTGMAC100 Gigabit SoC Ethernet
1303
1304 CONFIG_FTGMAC100_EGIGA
1305 Define this to use GE link update with gigabit PHY.
1306 Define this if FTGMAC100 is connected to gigabit PHY.
1307 If your system has 10/100 PHY only, it might not occur
1308 wrong behavior. Because PHY usually return timeout or
1309 useless data when polling gigabit status and gigabit
1310 control registers. This behavior won't affect the
1311 correctnessof 10/100 link speed update.
1312
1313 CONFIG_SMC911X
1314 Support for SMSC's LAN911x and LAN921x chips
1315
1316 CONFIG_SMC911X_BASE
1317 Define this to hold the physical address
1318 of the device (I/O space)
1319
1320 CONFIG_SMC911X_32_BIT
1321 Define this if data bus is 32 bits
1322
1323 CONFIG_SMC911X_16_BIT
1324 Define this if data bus is 16 bits. If your processor
1325 automatically converts one 32 bit word to two 16 bit
1326 words you may also try CONFIG_SMC911X_32_BIT.
1327
1328 CONFIG_SH_ETHER
1329 Support for Renesas on-chip Ethernet controller
1330
1331 CONFIG_SH_ETHER_USE_PORT
1332 Define the number of ports to be used
1333
1334 CONFIG_SH_ETHER_PHY_ADDR
1335 Define the ETH PHY's address
1336
1337 CONFIG_SH_ETHER_CACHE_WRITEBACK
1338 If this option is set, the driver enables cache flush.
1339
1340 - PWM Support:
1341 CONFIG_PWM_IMX
1342 Support for PWM module on the imx6.
1343
1344 - TPM Support:
1345 CONFIG_TPM
1346 Support TPM devices.
1347
1348 CONFIG_TPM_TIS_INFINEON
1349 Support for Infineon i2c bus TPM devices. Only one device
1350 per system is supported at this time.
1351
1352 CONFIG_TPM_TIS_I2C_BURST_LIMITATION
1353 Define the burst count bytes upper limit
1354
1355 CONFIG_TPM_ST33ZP24
1356 Support for STMicroelectronics TPM devices. Requires DM_TPM support.
1357
1358 CONFIG_TPM_ST33ZP24_I2C
1359 Support for STMicroelectronics ST33ZP24 I2C devices.
1360 Requires TPM_ST33ZP24 and I2C.
1361
1362 CONFIG_TPM_ST33ZP24_SPI
1363 Support for STMicroelectronics ST33ZP24 SPI devices.
1364 Requires TPM_ST33ZP24 and SPI.
1365
1366 CONFIG_TPM_ATMEL_TWI
1367 Support for Atmel TWI TPM device. Requires I2C support.
1368
1369 CONFIG_TPM_TIS_LPC
1370 Support for generic parallel port TPM devices. Only one device
1371 per system is supported at this time.
1372
1373 CONFIG_TPM_TIS_BASE_ADDRESS
1374 Base address where the generic TPM device is mapped
1375 to. Contemporary x86 systems usually map it at
1376 0xfed40000.
1377
1378 CONFIG_CMD_TPM
1379 Add tpm monitor functions.
1380 Requires CONFIG_TPM. If CONFIG_TPM_AUTH_SESSIONS is set, also
1381 provides monitor access to authorized functions.
1382
1383 CONFIG_TPM
1384 Define this to enable the TPM support library which provides
1385 functional interfaces to some TPM commands.
1386 Requires support for a TPM device.
1387
1388 CONFIG_TPM_AUTH_SESSIONS
1389 Define this to enable authorized functions in the TPM library.
1390 Requires CONFIG_TPM and CONFIG_SHA1.
1391
1392 - USB Support:
1393 At the moment only the UHCI host controller is
1394 supported (PIP405, MIP405, MPC5200); define
1395 CONFIG_USB_UHCI to enable it.
1396 define CONFIG_USB_KEYBOARD to enable the USB Keyboard
1397 and define CONFIG_USB_STORAGE to enable the USB
1398 storage devices.
1399 Note:
1400 Supported are USB Keyboards and USB Floppy drives
1401 (TEAC FD-05PUB).
1402 MPC5200 USB requires additional defines:
1403 CONFIG_USB_CLOCK
1404 for 528 MHz Clock: 0x0001bbbb
1405 CONFIG_PSC3_USB
1406 for USB on PSC3
1407 CONFIG_USB_CONFIG
1408 for differential drivers: 0x00001000
1409 for single ended drivers: 0x00005000
1410 for differential drivers on PSC3: 0x00000100
1411 for single ended drivers on PSC3: 0x00004100
1412 CONFIG_SYS_USB_EVENT_POLL
1413 May be defined to allow interrupt polling
1414 instead of using asynchronous interrupts
1415
1416 CONFIG_USB_EHCI_TXFIFO_THRESH enables setting of the
1417 txfilltuning field in the EHCI controller on reset.
1418
1419 CONFIG_USB_DWC2_REG_ADDR the physical CPU address of the DWC2
1420 HW module registers.
1421
1422 - USB Device:
1423 Define the below if you wish to use the USB console.
1424 Once firmware is rebuilt from a serial console issue the
1425 command "setenv stdin usbtty; setenv stdout usbtty" and
1426 attach your USB cable. The Unix command "dmesg" should print
1427 it has found a new device. The environment variable usbtty
1428 can be set to gserial or cdc_acm to enable your device to
1429 appear to a USB host as a Linux gserial device or a
1430 Common Device Class Abstract Control Model serial device.
1431 If you select usbtty = gserial you should be able to enumerate
1432 a Linux host by
1433 # modprobe usbserial vendor=0xVendorID product=0xProductID
1434 else if using cdc_acm, simply setting the environment
1435 variable usbtty to be cdc_acm should suffice. The following
1436 might be defined in YourBoardName.h
1437
1438 CONFIG_USB_DEVICE
1439 Define this to build a UDC device
1440
1441 CONFIG_USB_TTY
1442 Define this to have a tty type of device available to
1443 talk to the UDC device
1444
1445 CONFIG_USBD_HS
1446 Define this to enable the high speed support for usb
1447 device and usbtty. If this feature is enabled, a routine
1448 int is_usbd_high_speed(void)
1449 also needs to be defined by the driver to dynamically poll
1450 whether the enumeration has succeded at high speed or full
1451 speed.
1452
1453 CONFIG_SYS_CONSOLE_IS_IN_ENV
1454 Define this if you want stdin, stdout &/or stderr to
1455 be set to usbtty.
1456
1457 mpc8xx:
1458 CONFIG_SYS_USB_EXTC_CLK 0xBLAH
1459 Derive USB clock from external clock "blah"
1460 - CONFIG_SYS_USB_EXTC_CLK 0x02
1461
1462 If you have a USB-IF assigned VendorID then you may wish to
1463 define your own vendor specific values either in BoardName.h
1464 or directly in usbd_vendor_info.h. If you don't define
1465 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME,
1466 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot
1467 should pretend to be a Linux device to it's target host.
1468
1469 CONFIG_USBD_MANUFACTURER
1470 Define this string as the name of your company for
1471 - CONFIG_USBD_MANUFACTURER "my company"
1472
1473 CONFIG_USBD_PRODUCT_NAME
1474 Define this string as the name of your product
1475 - CONFIG_USBD_PRODUCT_NAME "acme usb device"
1476
1477 CONFIG_USBD_VENDORID
1478 Define this as your assigned Vendor ID from the USB
1479 Implementors Forum. This *must* be a genuine Vendor ID
1480 to avoid polluting the USB namespace.
1481 - CONFIG_USBD_VENDORID 0xFFFF
1482
1483 CONFIG_USBD_PRODUCTID
1484 Define this as the unique Product ID
1485 for your device
1486 - CONFIG_USBD_PRODUCTID 0xFFFF
1487
1488 - ULPI Layer Support:
1489 The ULPI (UTMI Low Pin (count) Interface) PHYs are supported via
1490 the generic ULPI layer. The generic layer accesses the ULPI PHY
1491 via the platform viewport, so you need both the genric layer and
1492 the viewport enabled. Currently only Chipidea/ARC based
1493 viewport is supported.
1494 To enable the ULPI layer support, define CONFIG_USB_ULPI and
1495 CONFIG_USB_ULPI_VIEWPORT in your board configuration file.
1496 If your ULPI phy needs a different reference clock than the
1497 standard 24 MHz then you have to define CONFIG_ULPI_REF_CLK to
1498 the appropriate value in Hz.
1499
1500 - MMC Support:
1501 The MMC controller on the Intel PXA is supported. To
1502 enable this define CONFIG_MMC. The MMC can be
1503 accessed from the boot prompt by mapping the device
1504 to physical memory similar to flash. Command line is
1505 enabled with CONFIG_CMD_MMC. The MMC driver also works with
1506 the FAT fs. This is enabled with CONFIG_CMD_FAT.
1507
1508 CONFIG_SH_MMCIF
1509 Support for Renesas on-chip MMCIF controller
1510
1511 CONFIG_SH_MMCIF_ADDR
1512 Define the base address of MMCIF registers
1513
1514 CONFIG_SH_MMCIF_CLK
1515 Define the clock frequency for MMCIF
1516
1517 CONFIG_GENERIC_MMC
1518 Enable the generic MMC driver
1519
1520 CONFIG_SUPPORT_EMMC_BOOT
1521 Enable some additional features of the eMMC boot partitions.
1522
1523 CONFIG_SUPPORT_EMMC_RPMB
1524 Enable the commands for reading, writing and programming the
1525 key for the Replay Protection Memory Block partition in eMMC.
1526
1527 - USB Device Firmware Update (DFU) class support:
1528 CONFIG_USB_FUNCTION_DFU
1529 This enables the USB portion of the DFU USB class
1530
1531 CONFIG_CMD_DFU
1532 This enables the command "dfu" which is used to have
1533 U-Boot create a DFU class device via USB. This command
1534 requires that the "dfu_alt_info" environment variable be
1535 set and define the alt settings to expose to the host.
1536
1537 CONFIG_DFU_MMC
1538 This enables support for exposing (e)MMC devices via DFU.
1539
1540 CONFIG_DFU_NAND
1541 This enables support for exposing NAND devices via DFU.
1542
1543 CONFIG_DFU_RAM
1544 This enables support for exposing RAM via DFU.
1545 Note: DFU spec refer to non-volatile memory usage, but
1546 allow usages beyond the scope of spec - here RAM usage,
1547 one that would help mostly the developer.
1548
1549 CONFIG_SYS_DFU_DATA_BUF_SIZE
1550 Dfu transfer uses a buffer before writing data to the
1551 raw storage device. Make the size (in bytes) of this buffer
1552 configurable. The size of this buffer is also configurable
1553 through the "dfu_bufsiz" environment variable.
1554
1555 CONFIG_SYS_DFU_MAX_FILE_SIZE
1556 When updating files rather than the raw storage device,
1557 we use a static buffer to copy the file into and then write
1558 the buffer once we've been given the whole file. Define
1559 this to the maximum filesize (in bytes) for the buffer.
1560 Default is 4 MiB if undefined.
1561
1562 DFU_DEFAULT_POLL_TIMEOUT
1563 Poll timeout [ms], is the timeout a device can send to the
1564 host. The host must wait for this timeout before sending
1565 a subsequent DFU_GET_STATUS request to the device.
1566
1567 DFU_MANIFEST_POLL_TIMEOUT
1568 Poll timeout [ms], which the device sends to the host when
1569 entering dfuMANIFEST state. Host waits this timeout, before
1570 sending again an USB request to the device.
1571
1572 - USB Device Android Fastboot support:
1573 CONFIG_USB_FUNCTION_FASTBOOT
1574 This enables the USB part of the fastboot gadget
1575
1576 CONFIG_CMD_FASTBOOT
1577 This enables the command "fastboot" which enables the Android
1578 fastboot mode for the platform's USB device. Fastboot is a USB
1579 protocol for downloading images, flashing and device control
1580 used on Android devices.
1581 See doc/README.android-fastboot for more information.
1582
1583 CONFIG_ANDROID_BOOT_IMAGE
1584 This enables support for booting images which use the Android
1585 image format header.
1586
1587 CONFIG_FASTBOOT_BUF_ADDR
1588 The fastboot protocol requires a large memory buffer for
1589 downloads. Define this to the starting RAM address to use for
1590 downloaded images.
1591
1592 CONFIG_FASTBOOT_BUF_SIZE
1593 The fastboot protocol requires a large memory buffer for
1594 downloads. This buffer should be as large as possible for a
1595 platform. Define this to the size available RAM for fastboot.
1596
1597 CONFIG_FASTBOOT_FLASH
1598 The fastboot protocol includes a "flash" command for writing
1599 the downloaded image to a non-volatile storage device. Define
1600 this to enable the "fastboot flash" command.
1601
1602 CONFIG_FASTBOOT_FLASH_MMC_DEV
1603 The fastboot "flash" command requires additional information
1604 regarding the non-volatile storage device. Define this to
1605 the eMMC device that fastboot should use to store the image.
1606
1607 CONFIG_FASTBOOT_GPT_NAME
1608 The fastboot "flash" command supports writing the downloaded
1609 image to the Protective MBR and the Primary GUID Partition
1610 Table. (Additionally, this downloaded image is post-processed
1611 to generate and write the Backup GUID Partition Table.)
1612 This occurs when the specified "partition name" on the
1613 "fastboot flash" command line matches this value.
1614 The default is "gpt" if undefined.
1615
1616 CONFIG_FASTBOOT_MBR_NAME
1617 The fastboot "flash" command supports writing the downloaded
1618 image to DOS MBR.
1619 This occurs when the "partition name" specified on the
1620 "fastboot flash" command line matches this value.
1621 If not defined the default value "mbr" is used.
1622
1623 - Journaling Flash filesystem support:
1624 CONFIG_JFFS2_NAND
1625 Define these for a default partition on a NAND device
1626
1627 CONFIG_SYS_JFFS2_FIRST_SECTOR,
1628 CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS
1629 Define these for a default partition on a NOR device
1630
1631 - FAT(File Allocation Table) filesystem write function support:
1632 CONFIG_FAT_WRITE
1633
1634 Define this to enable support for saving memory data as a
1635 file in FAT formatted partition.
1636
1637 This will also enable the command "fatwrite" enabling the
1638 user to write files to FAT.
1639
1640 CBFS (Coreboot Filesystem) support
1641 CONFIG_CMD_CBFS
1642
1643 Define this to enable support for reading from a Coreboot
1644 filesystem. Available commands are cbfsinit, cbfsinfo, cbfsls
1645 and cbfsload.
1646
1647 - FAT(File Allocation Table) filesystem cluster size:
1648 CONFIG_FS_FAT_MAX_CLUSTSIZE
1649
1650 Define the max cluster size for fat operations else
1651 a default value of 65536 will be defined.
1652
1653 - Keyboard Support:
1654 See Kconfig help for available keyboard drivers.
1655
1656 CONFIG_KEYBOARD
1657
1658 Define this to enable a custom keyboard support.
1659 This simply calls drv_keyboard_init() which must be
1660 defined in your board-specific files. This option is deprecated
1661 and is only used by novena. For new boards, use driver model
1662 instead.
1663
1664 - Video support:
1665 CONFIG_VIDEO
1666
1667 Define this to enable video support (for output to
1668 video).
1669
1670 CONFIG_VIDEO_CT69000
1671
1672 Enable Chips & Technologies 69000 Video chip
1673
1674 CONFIG_VIDEO_SMI_LYNXEM
1675 Enable Silicon Motion SMI 712/710/810 Video chip. The
1676 video output is selected via environment 'videoout'
1677 (1 = LCD and 2 = CRT). If videoout is undefined, CRT is
1678 assumed.
1679
1680 For the CT69000 and SMI_LYNXEM drivers, videomode is
1681 selected via environment 'videomode'. Two different ways
1682 are possible:
1683 - "videomode=num" 'num' is a standard LiLo mode numbers.
1684 Following standard modes are supported (* is default):
1685
1686 Colors 640x480 800x600 1024x768 1152x864 1280x1024
1687 -------------+---------------------------------------------
1688 8 bits | 0x301* 0x303 0x305 0x161 0x307
1689 15 bits | 0x310 0x313 0x316 0x162 0x319
1690 16 bits | 0x311 0x314 0x317 0x163 0x31A
1691 24 bits | 0x312 0x315 0x318 ? 0x31B
1692 -------------+---------------------------------------------
1693 (i.e. setenv videomode 317; saveenv; reset;)
1694
1695 - "videomode=bootargs" all the video parameters are parsed
1696 from the bootargs. (See drivers/video/videomodes.c)
1697
1698
1699 CONFIG_VIDEO_SED13806
1700 Enable Epson SED13806 driver. This driver supports 8bpp
1701 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP
1702 or CONFIG_VIDEO_SED13806_16BPP
1703
1704 CONFIG_FSL_DIU_FB
1705 Enable the Freescale DIU video driver. Reference boards for
1706 SOCs that have a DIU should define this macro to enable DIU
1707 support, and should also define these other macros:
1708
1709 CONFIG_SYS_DIU_ADDR
1710 CONFIG_VIDEO
1711 CONFIG_CMD_BMP
1712 CONFIG_CFB_CONSOLE
1713 CONFIG_VIDEO_SW_CURSOR
1714 CONFIG_VGA_AS_SINGLE_DEVICE
1715 CONFIG_VIDEO_LOGO
1716 CONFIG_VIDEO_BMP_LOGO
1717
1718 The DIU driver will look for the 'video-mode' environment
1719 variable, and if defined, enable the DIU as a console during
1720 boot. See the documentation file doc/README.video for a
1721 description of this variable.
1722
1723 - LCD Support: CONFIG_LCD
1724
1725 Define this to enable LCD support (for output to LCD
1726 display); also select one of the supported displays
1727 by defining one of these:
1728
1729 CONFIG_ATMEL_LCD:
1730
1731 HITACHI TX09D70VM1CCA, 3.5", 240x320.
1732
1733 CONFIG_NEC_NL6448AC33:
1734
1735 NEC NL6448AC33-18. Active, color, single scan.
1736
1737 CONFIG_NEC_NL6448BC20
1738
1739 NEC NL6448BC20-08. 6.5", 640x480.
1740 Active, color, single scan.
1741
1742 CONFIG_NEC_NL6448BC33_54
1743
1744 NEC NL6448BC33-54. 10.4", 640x480.
1745 Active, color, single scan.
1746
1747 CONFIG_SHARP_16x9
1748
1749 Sharp 320x240. Active, color, single scan.
1750 It isn't 16x9, and I am not sure what it is.
1751
1752 CONFIG_SHARP_LQ64D341
1753
1754 Sharp LQ64D341 display, 640x480.
1755 Active, color, single scan.
1756
1757 CONFIG_HLD1045
1758
1759 HLD1045 display, 640x480.
1760 Active, color, single scan.
1761
1762 CONFIG_OPTREX_BW
1763
1764 Optrex CBL50840-2 NF-FW 99 22 M5
1765 or
1766 Hitachi LMG6912RPFC-00T
1767 or
1768 Hitachi SP14Q002
1769
1770 320x240. Black & white.
1771
1772 Normally display is black on white background; define
1773 CONFIG_SYS_WHITE_ON_BLACK to get it inverted.
1774
1775 CONFIG_LCD_ALIGNMENT
1776
1777 Normally the LCD is page-aligned (typically 4KB). If this is
1778 defined then the LCD will be aligned to this value instead.
1779 For ARM it is sometimes useful to use MMU_SECTION_SIZE
1780 here, since it is cheaper to change data cache settings on
1781 a per-section basis.
1782
1783 CONFIG_CONSOLE_SCROLL_LINES
1784
1785 When the console need to be scrolled, this is the number of
1786 lines to scroll by. It defaults to 1. Increasing this makes
1787 the console jump but can help speed up operation when scrolling
1788 is slow.
1789
1790 CONFIG_LCD_ROTATION
1791
1792 Sometimes, for example if the display is mounted in portrait
1793 mode or even if it's mounted landscape but rotated by 180degree,
1794 we need to rotate our content of the display relative to the
1795 framebuffer, so that user can read the messages which are
1796 printed out.
1797 Once CONFIG_LCD_ROTATION is defined, the lcd_console will be
1798 initialized with a given rotation from "vl_rot" out of
1799 "vidinfo_t" which is provided by the board specific code.
1800 The value for vl_rot is coded as following (matching to
1801 fbcon=rotate:<n> linux-kernel commandline):
1802 0 = no rotation respectively 0 degree
1803 1 = 90 degree rotation
1804 2 = 180 degree rotation
1805 3 = 270 degree rotation
1806
1807 If CONFIG_LCD_ROTATION is not defined, the console will be
1808 initialized with 0degree rotation.
1809
1810 CONFIG_LCD_BMP_RLE8
1811
1812 Support drawing of RLE8-compressed bitmaps on the LCD.
1813
1814 CONFIG_I2C_EDID
1815
1816 Enables an 'i2c edid' command which can read EDID
1817 information over I2C from an attached LCD display.
1818
1819 - Splash Screen Support: CONFIG_SPLASH_SCREEN
1820
1821 If this option is set, the environment is checked for
1822 a variable "splashimage". If found, the usual display
1823 of logo, copyright and system information on the LCD
1824 is suppressed and the BMP image at the address
1825 specified in "splashimage" is loaded instead. The
1826 console is redirected to the "nulldev", too. This
1827 allows for a "silent" boot where a splash screen is
1828 loaded very quickly after power-on.
1829
1830 CONFIG_SPLASHIMAGE_GUARD
1831
1832 If this option is set, then U-Boot will prevent the environment
1833 variable "splashimage" from being set to a problematic address
1834 (see doc/README.displaying-bmps).
1835 This option is useful for targets where, due to alignment
1836 restrictions, an improperly aligned BMP image will cause a data
1837 abort. If you think you will not have problems with unaligned
1838 accesses (for example because your toolchain prevents them)
1839 there is no need to set this option.
1840
1841 CONFIG_SPLASH_SCREEN_ALIGN
1842
1843 If this option is set the splash image can be freely positioned
1844 on the screen. Environment variable "splashpos" specifies the
1845 position as "x,y". If a positive number is given it is used as
1846 number of pixel from left/top. If a negative number is given it
1847 is used as number of pixel from right/bottom. You can also
1848 specify 'm' for centering the image.
1849
1850 Example:
1851 setenv splashpos m,m
1852 => image at center of screen
1853
1854 setenv splashpos 30,20
1855 => image at x = 30 and y = 20
1856
1857 setenv splashpos -10,m
1858 => vertically centered image
1859 at x = dspWidth - bmpWidth - 9
1860
1861 - Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP
1862
1863 If this option is set, additionally to standard BMP
1864 images, gzipped BMP images can be displayed via the
1865 splashscreen support or the bmp command.
1866
1867 - Run length encoded BMP image (RLE8) support: CONFIG_VIDEO_BMP_RLE8
1868
1869 If this option is set, 8-bit RLE compressed BMP images
1870 can be displayed via the splashscreen support or the
1871 bmp command.
1872
1873 - Do compressing for memory range:
1874 CONFIG_CMD_ZIP
1875
1876 If this option is set, it would use zlib deflate method
1877 to compress the specified memory at its best effort.
1878
1879 - Compression support:
1880 CONFIG_GZIP
1881
1882 Enabled by default to support gzip compressed images.
1883
1884 CONFIG_BZIP2
1885
1886 If this option is set, support for bzip2 compressed
1887 images is included. If not, only uncompressed and gzip
1888 compressed images are supported.
1889
1890 NOTE: the bzip2 algorithm requires a lot of RAM, so
1891 the malloc area (as defined by CONFIG_SYS_MALLOC_LEN) should
1892 be at least 4MB.
1893
1894 CONFIG_LZMA
1895
1896 If this option is set, support for lzma compressed
1897 images is included.
1898
1899 Note: The LZMA algorithm adds between 2 and 4KB of code and it
1900 requires an amount of dynamic memory that is given by the
1901 formula:
1902
1903 (1846 + 768 << (lc + lp)) * sizeof(uint16)
1904
1905 Where lc and lp stand for, respectively, Literal context bits
1906 and Literal pos bits.
1907
1908 This value is upper-bounded by 14MB in the worst case. Anyway,
1909 for a ~4MB large kernel image, we have lc=3 and lp=0 for a
1910 total amount of (1846 + 768 << (3 + 0)) * 2 = ~41KB... that is
1911 a very small buffer.
1912
1913 Use the lzmainfo tool to determinate the lc and lp values and
1914 then calculate the amount of needed dynamic memory (ensuring
1915 the appropriate CONFIG_SYS_MALLOC_LEN value).
1916
1917 CONFIG_LZO
1918
1919 If this option is set, support for LZO compressed images
1920 is included.
1921
1922 - MII/PHY support:
1923 CONFIG_PHY_ADDR
1924
1925 The address of PHY on MII bus.
1926
1927 CONFIG_PHY_CLOCK_FREQ (ppc4xx)
1928
1929 The clock frequency of the MII bus
1930
1931 CONFIG_PHY_GIGE
1932
1933 If this option is set, support for speed/duplex
1934 detection of gigabit PHY is included.
1935
1936 CONFIG_PHY_RESET_DELAY
1937
1938 Some PHY like Intel LXT971A need extra delay after
1939 reset before any MII register access is possible.
1940 For such PHY, set this option to the usec delay
1941 required. (minimum 300usec for LXT971A)
1942
1943 CONFIG_PHY_CMD_DELAY (ppc4xx)
1944
1945 Some PHY like Intel LXT971A need extra delay after
1946 command issued before MII status register can be read
1947
1948 - IP address:
1949 CONFIG_IPADDR
1950
1951 Define a default value for the IP address to use for
1952 the default Ethernet interface, in case this is not
1953 determined through e.g. bootp.
1954 (Environment variable "ipaddr")
1955
1956 - Server IP address:
1957 CONFIG_SERVERIP
1958
1959 Defines a default value for the IP address of a TFTP
1960 server to contact when using the "tftboot" command.
1961 (Environment variable "serverip")
1962
1963 CONFIG_KEEP_SERVERADDR
1964
1965 Keeps the server's MAC address, in the env 'serveraddr'
1966 for passing to bootargs (like Linux's netconsole option)
1967
1968 - Gateway IP address:
1969 CONFIG_GATEWAYIP
1970
1971 Defines a default value for the IP address of the
1972 default router where packets to other networks are
1973 sent to.
1974 (Environment variable "gatewayip")
1975
1976 - Subnet mask:
1977 CONFIG_NETMASK
1978
1979 Defines a default value for the subnet mask (or
1980 routing prefix) which is used to determine if an IP
1981 address belongs to the local subnet or needs to be
1982 forwarded through a router.
1983 (Environment variable "netmask")
1984
1985 - Multicast TFTP Mode:
1986 CONFIG_MCAST_TFTP
1987
1988 Defines whether you want to support multicast TFTP as per
1989 rfc-2090; for example to work with atftp. Lets lots of targets
1990 tftp down the same boot image concurrently. Note: the Ethernet
1991 driver in use must provide a function: mcast() to join/leave a
1992 multicast group.
1993
1994 - BOOTP Recovery Mode:
1995 CONFIG_BOOTP_RANDOM_DELAY
1996
1997 If you have many targets in a network that try to
1998 boot using BOOTP, you may want to avoid that all
1999 systems send out BOOTP requests at precisely the same
2000 moment (which would happen for instance at recovery
2001 from a power failure, when all systems will try to
2002 boot, thus flooding the BOOTP server. Defining
2003 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
2004 inserted before sending out BOOTP requests. The
2005 following delays are inserted then:
2006
2007 1st BOOTP request: delay 0 ... 1 sec
2008 2nd BOOTP request: delay 0 ... 2 sec
2009 3rd BOOTP request: delay 0 ... 4 sec
2010 4th and following
2011 BOOTP requests: delay 0 ... 8 sec
2012
2013 CONFIG_BOOTP_ID_CACHE_SIZE
2014
2015 BOOTP packets are uniquely identified using a 32-bit ID. The
2016 server will copy the ID from client requests to responses and
2017 U-Boot will use this to determine if it is the destination of
2018 an incoming response. Some servers will check that addresses
2019 aren't in use before handing them out (usually using an ARP
2020 ping) and therefore take up to a few hundred milliseconds to
2021 respond. Network congestion may also influence the time it
2022 takes for a response to make it back to the client. If that
2023 time is too long, U-Boot will retransmit requests. In order
2024 to allow earlier responses to still be accepted after these
2025 retransmissions, U-Boot's BOOTP client keeps a small cache of
2026 IDs. The CONFIG_BOOTP_ID_CACHE_SIZE controls the size of this
2027 cache. The default is to keep IDs for up to four outstanding
2028 requests. Increasing this will allow U-Boot to accept offers
2029 from a BOOTP client in networks with unusually high latency.
2030
2031 - DHCP Advanced Options:
2032 You can fine tune the DHCP functionality by defining
2033 CONFIG_BOOTP_* symbols:
2034
2035 CONFIG_BOOTP_SUBNETMASK
2036 CONFIG_BOOTP_GATEWAY
2037 CONFIG_BOOTP_HOSTNAME
2038 CONFIG_BOOTP_NISDOMAIN
2039 CONFIG_BOOTP_BOOTPATH
2040 CONFIG_BOOTP_BOOTFILESIZE
2041 CONFIG_BOOTP_DNS
2042 CONFIG_BOOTP_DNS2
2043 CONFIG_BOOTP_SEND_HOSTNAME
2044 CONFIG_BOOTP_NTPSERVER
2045 CONFIG_BOOTP_TIMEOFFSET
2046 CONFIG_BOOTP_VENDOREX
2047 CONFIG_BOOTP_MAY_FAIL
2048
2049 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip
2050 environment variable, not the BOOTP server.
2051
2052 CONFIG_BOOTP_MAY_FAIL - If the DHCP server is not found
2053 after the configured retry count, the call will fail
2054 instead of starting over. This can be used to fail over
2055 to Link-local IP address configuration if the DHCP server
2056 is not available.
2057
2058 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS
2059 serverip from a DHCP server, it is possible that more
2060 than one DNS serverip is offered to the client.
2061 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS
2062 serverip will be stored in the additional environment
2063 variable "dnsip2". The first DNS serverip is always
2064 stored in the variable "dnsip", when CONFIG_BOOTP_DNS
2065 is defined.
2066
2067 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable
2068 to do a dynamic update of a DNS server. To do this, they
2069 need the hostname of the DHCP requester.
2070 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content
2071 of the "hostname" environment variable is passed as
2072 option 12 to the DHCP server.
2073
2074 CONFIG_BOOTP_DHCP_REQUEST_DELAY
2075
2076 A 32bit value in microseconds for a delay between
2077 receiving a "DHCP Offer" and sending the "DHCP Request".
2078 This fixes a problem with certain DHCP servers that don't
2079 respond 100% of the time to a "DHCP request". E.g. On an
2080 AT91RM9200 processor running at 180MHz, this delay needed
2081 to be *at least* 15,000 usec before a Windows Server 2003
2082 DHCP server would reply 100% of the time. I recommend at
2083 least 50,000 usec to be safe. The alternative is to hope
2084 that one of the retries will be successful but note that
2085 the DHCP timeout and retry process takes a longer than
2086 this delay.
2087
2088 - Link-local IP address negotiation:
2089 Negotiate with other link-local clients on the local network
2090 for an address that doesn't require explicit configuration.
2091 This is especially useful if a DHCP server cannot be guaranteed
2092 to exist in all environments that the device must operate.
2093
2094 See doc/README.link-local for more information.
2095
2096 - CDP Options:
2097 CONFIG_CDP_DEVICE_ID
2098
2099 The device id used in CDP trigger frames.
2100
2101 CONFIG_CDP_DEVICE_ID_PREFIX
2102
2103 A two character string which is prefixed to the MAC address
2104 of the device.
2105
2106 CONFIG_CDP_PORT_ID
2107
2108 A printf format string which contains the ascii name of
2109 the port. Normally is set to "eth%d" which sets
2110 eth0 for the first Ethernet, eth1 for the second etc.
2111
2112 CONFIG_CDP_CAPABILITIES
2113
2114 A 32bit integer which indicates the device capabilities;
2115 0x00000010 for a normal host which does not forwards.
2116
2117 CONFIG_CDP_VERSION
2118
2119 An ascii string containing the version of the software.
2120
2121 CONFIG_CDP_PLATFORM
2122
2123 An ascii string containing the name of the platform.
2124
2125 CONFIG_CDP_TRIGGER
2126
2127 A 32bit integer sent on the trigger.
2128
2129 CONFIG_CDP_POWER_CONSUMPTION
2130
2131 A 16bit integer containing the power consumption of the
2132 device in .1 of milliwatts.
2133
2134 CONFIG_CDP_APPLIANCE_VLAN_TYPE
2135
2136 A byte containing the id of the VLAN.
2137
2138 - Status LED: CONFIG_STATUS_LED
2139
2140 Several configurations allow to display the current
2141 status using a LED. For instance, the LED will blink
2142 fast while running U-Boot code, stop blinking as
2143 soon as a reply to a BOOTP request was received, and
2144 start blinking slow once the Linux kernel is running
2145 (supported by a status LED driver in the Linux
2146 kernel). Defining CONFIG_STATUS_LED enables this
2147 feature in U-Boot.
2148
2149 Additional options:
2150
2151 CONFIG_GPIO_LED
2152 The status LED can be connected to a GPIO pin.
2153 In such cases, the gpio_led driver can be used as a
2154 status LED backend implementation. Define CONFIG_GPIO_LED
2155 to include the gpio_led driver in the U-Boot binary.
2156
2157 CONFIG_GPIO_LED_INVERTED_TABLE
2158 Some GPIO connected LEDs may have inverted polarity in which
2159 case the GPIO high value corresponds to LED off state and
2160 GPIO low value corresponds to LED on state.
2161 In such cases CONFIG_GPIO_LED_INVERTED_TABLE may be defined
2162 with a list of GPIO LEDs that have inverted polarity.
2163
2164 - CAN Support: CONFIG_CAN_DRIVER
2165
2166 Defining CONFIG_CAN_DRIVER enables CAN driver support
2167 on those systems that support this (optional)
2168 feature, like the TQM8xxL modules.
2169
2170 - I2C Support: CONFIG_SYS_I2C
2171
2172 This enable the NEW i2c subsystem, and will allow you to use
2173 i2c commands at the u-boot command line (as long as you set
2174 CONFIG_CMD_I2C in CONFIG_COMMANDS) and communicate with i2c
2175 based realtime clock chips or other i2c devices. See
2176 common/cmd_i2c.c for a description of the command line
2177 interface.
2178
2179 ported i2c driver to the new framework:
2180 - drivers/i2c/soft_i2c.c:
2181 - activate first bus with CONFIG_SYS_I2C_SOFT define
2182 CONFIG_SYS_I2C_SOFT_SPEED and CONFIG_SYS_I2C_SOFT_SLAVE
2183 for defining speed and slave address
2184 - activate second bus with I2C_SOFT_DECLARATIONS2 define
2185 CONFIG_SYS_I2C_SOFT_SPEED_2 and CONFIG_SYS_I2C_SOFT_SLAVE_2
2186 for defining speed and slave address
2187 - activate third bus with I2C_SOFT_DECLARATIONS3 define
2188 CONFIG_SYS_I2C_SOFT_SPEED_3 and CONFIG_SYS_I2C_SOFT_SLAVE_3
2189 for defining speed and slave address
2190 - activate fourth bus with I2C_SOFT_DECLARATIONS4 define
2191 CONFIG_SYS_I2C_SOFT_SPEED_4 and CONFIG_SYS_I2C_SOFT_SLAVE_4
2192 for defining speed and slave address
2193
2194 - drivers/i2c/fsl_i2c.c:
2195 - activate i2c driver with CONFIG_SYS_I2C_FSL
2196 define CONFIG_SYS_FSL_I2C_OFFSET for setting the register
2197 offset CONFIG_SYS_FSL_I2C_SPEED for the i2c speed and
2198 CONFIG_SYS_FSL_I2C_SLAVE for the slave addr of the first
2199 bus.
2200 - If your board supports a second fsl i2c bus, define
2201 CONFIG_SYS_FSL_I2C2_OFFSET for the register offset
2202 CONFIG_SYS_FSL_I2C2_SPEED for the speed and
2203 CONFIG_SYS_FSL_I2C2_SLAVE for the slave address of the
2204 second bus.
2205
2206 - drivers/i2c/tegra_i2c.c:
2207 - activate this driver with CONFIG_SYS_I2C_TEGRA
2208 - This driver adds 4 i2c buses with a fix speed from
2209 100000 and the slave addr 0!
2210
2211 - drivers/i2c/ppc4xx_i2c.c
2212 - activate this driver with CONFIG_SYS_I2C_PPC4XX
2213 - CONFIG_SYS_I2C_PPC4XX_CH0 activate hardware channel 0
2214 - CONFIG_SYS_I2C_PPC4XX_CH1 activate hardware channel 1
2215
2216 - drivers/i2c/i2c_mxc.c
2217 - activate this driver with CONFIG_SYS_I2C_MXC
2218 - enable bus 1 with CONFIG_SYS_I2C_MXC_I2C1
2219 - enable bus 2 with CONFIG_SYS_I2C_MXC_I2C2
2220 - enable bus 3 with CONFIG_SYS_I2C_MXC_I2C3
2221 - enable bus 4 with CONFIG_SYS_I2C_MXC_I2C4
2222 - define speed for bus 1 with CONFIG_SYS_MXC_I2C1_SPEED
2223 - define slave for bus 1 with CONFIG_SYS_MXC_I2C1_SLAVE
2224 - define speed for bus 2 with CONFIG_SYS_MXC_I2C2_SPEED
2225 - define slave for bus 2 with CONFIG_SYS_MXC_I2C2_SLAVE
2226 - define speed for bus 3 with CONFIG_SYS_MXC_I2C3_SPEED
2227 - define slave for bus 3 with CONFIG_SYS_MXC_I2C3_SLAVE
2228 - define speed for bus 4 with CONFIG_SYS_MXC_I2C4_SPEED
2229 - define slave for bus 4 with CONFIG_SYS_MXC_I2C4_SLAVE
2230 If those defines are not set, default value is 100000
2231 for speed, and 0 for slave.
2232
2233 - drivers/i2c/rcar_i2c.c:
2234 - activate this driver with CONFIG_SYS_I2C_RCAR
2235 - This driver adds 4 i2c buses
2236
2237 - CONFIG_SYS_RCAR_I2C0_BASE for setting the register channel 0
2238 - CONFIG_SYS_RCAR_I2C0_SPEED for for the speed channel 0
2239 - CONFIG_SYS_RCAR_I2C1_BASE for setting the register channel 1
2240 - CONFIG_SYS_RCAR_I2C1_SPEED for for the speed channel 1
2241 - CONFIG_SYS_RCAR_I2C2_BASE for setting the register channel 2
2242 - CONFIG_SYS_RCAR_I2C2_SPEED for for the speed channel 2
2243 - CONFIG_SYS_RCAR_I2C3_BASE for setting the register channel 3
2244 - CONFIG_SYS_RCAR_I2C3_SPEED for for the speed channel 3
2245 - CONFIF_SYS_RCAR_I2C_NUM_CONTROLLERS for number of i2c buses
2246
2247 - drivers/i2c/sh_i2c.c:
2248 - activate this driver with CONFIG_SYS_I2C_SH
2249 - This driver adds from 2 to 5 i2c buses
2250
2251 - CONFIG_SYS_I2C_SH_BASE0 for setting the register channel 0
2252 - CONFIG_SYS_I2C_SH_SPEED0 for for the speed channel 0
2253 - CONFIG_SYS_I2C_SH_BASE1 for setting the register channel 1
2254 - CONFIG_SYS_I2C_SH_SPEED1 for for the speed channel 1
2255 - CONFIG_SYS_I2C_SH_BASE2 for setting the register channel 2
2256 - CONFIG_SYS_I2C_SH_SPEED2 for for the speed channel 2
2257 - CONFIG_SYS_I2C_SH_BASE3 for setting the register channel 3
2258 - CONFIG_SYS_I2C_SH_SPEED3 for for the speed channel 3
2259 - CONFIG_SYS_I2C_SH_BASE4 for setting the register channel 4
2260 - CONFIG_SYS_I2C_SH_SPEED4 for for the speed channel 4
2261 - CONFIG_SYS_I2C_SH_NUM_CONTROLLERS for number of i2c buses
2262
2263 - drivers/i2c/omap24xx_i2c.c
2264 - activate this driver with CONFIG_SYS_I2C_OMAP24XX
2265 - CONFIG_SYS_OMAP24_I2C_SPEED speed channel 0
2266 - CONFIG_SYS_OMAP24_I2C_SLAVE slave addr channel 0
2267 - CONFIG_SYS_OMAP24_I2C_SPEED1 speed channel 1
2268 - CONFIG_SYS_OMAP24_I2C_SLAVE1 slave addr channel 1
2269 - CONFIG_SYS_OMAP24_I2C_SPEED2 speed channel 2
2270 - CONFIG_SYS_OMAP24_I2C_SLAVE2 slave addr channel 2
2271 - CONFIG_SYS_OMAP24_I2C_SPEED3 speed channel 3
2272 - CONFIG_SYS_OMAP24_I2C_SLAVE3 slave addr channel 3
2273 - CONFIG_SYS_OMAP24_I2C_SPEED4 speed channel 4
2274 - CONFIG_SYS_OMAP24_I2C_SLAVE4 slave addr channel 4
2275
2276 - drivers/i2c/zynq_i2c.c
2277 - activate this driver with CONFIG_SYS_I2C_ZYNQ
2278 - set CONFIG_SYS_I2C_ZYNQ_SPEED for speed setting
2279 - set CONFIG_SYS_I2C_ZYNQ_SLAVE for slave addr
2280
2281 - drivers/i2c/s3c24x0_i2c.c:
2282 - activate this driver with CONFIG_SYS_I2C_S3C24X0
2283 - This driver adds i2c buses (11 for Exynos5250, Exynos5420
2284 9 i2c buses for Exynos4 and 1 for S3C24X0 SoCs from Samsung)
2285 with a fix speed from 100000 and the slave addr 0!
2286
2287 - drivers/i2c/ihs_i2c.c
2288 - activate this driver with CONFIG_SYS_I2C_IHS
2289 - CONFIG_SYS_I2C_IHS_CH0 activate hardware channel 0
2290 - CONFIG_SYS_I2C_IHS_SPEED_0 speed channel 0
2291 - CONFIG_SYS_I2C_IHS_SLAVE_0 slave addr channel 0
2292 - CONFIG_SYS_I2C_IHS_CH1 activate hardware channel 1
2293 - CONFIG_SYS_I2C_IHS_SPEED_1 speed channel 1
2294 - CONFIG_SYS_I2C_IHS_SLAVE_1 slave addr channel 1
2295 - CONFIG_SYS_I2C_IHS_CH2 activate hardware channel 2
2296 - CONFIG_SYS_I2C_IHS_SPEED_2 speed channel 2
2297 - CONFIG_SYS_I2C_IHS_SLAVE_2 slave addr channel 2
2298 - CONFIG_SYS_I2C_IHS_CH3 activate hardware channel 3
2299 - CONFIG_SYS_I2C_IHS_SPEED_3 speed channel 3
2300 - CONFIG_SYS_I2C_IHS_SLAVE_3 slave addr channel 3
2301 - activate dual channel with CONFIG_SYS_I2C_IHS_DUAL
2302 - CONFIG_SYS_I2C_IHS_SPEED_0_1 speed channel 0_1
2303 - CONFIG_SYS_I2C_IHS_SLAVE_0_1 slave addr channel 0_1
2304 - CONFIG_SYS_I2C_IHS_SPEED_1_1 speed channel 1_1
2305 - CONFIG_SYS_I2C_IHS_SLAVE_1_1 slave addr channel 1_1
2306 - CONFIG_SYS_I2C_IHS_SPEED_2_1 speed channel 2_1
2307 - CONFIG_SYS_I2C_IHS_SLAVE_2_1 slave addr channel 2_1
2308 - CONFIG_SYS_I2C_IHS_SPEED_3_1 speed channel 3_1
2309 - CONFIG_SYS_I2C_IHS_SLAVE_3_1 slave addr channel 3_1
2310
2311 additional defines:
2312
2313 CONFIG_SYS_NUM_I2C_BUSES
2314 Hold the number of i2c buses you want to use.
2315
2316 CONFIG_SYS_I2C_DIRECT_BUS
2317 define this, if you don't use i2c muxes on your hardware.
2318 if CONFIG_SYS_I2C_MAX_HOPS is not defined or == 0 you can
2319 omit this define.
2320
2321 CONFIG_SYS_I2C_MAX_HOPS
2322 define how many muxes are maximal consecutively connected
2323 on one i2c bus. If you not use i2c muxes, omit this
2324 define.
2325
2326 CONFIG_SYS_I2C_BUSES
2327 hold a list of buses you want to use, only used if
2328 CONFIG_SYS_I2C_DIRECT_BUS is not defined, for example
2329 a board with CONFIG_SYS_I2C_MAX_HOPS = 1 and
2330 CONFIG_SYS_NUM_I2C_BUSES = 9:
2331
2332 CONFIG_SYS_I2C_BUSES {{0, {I2C_NULL_HOP}}, \
2333 {0, {{I2C_MUX_PCA9547, 0x70, 1}}}, \
2334 {0, {{I2C_MUX_PCA9547, 0x70, 2}}}, \
2335 {0, {{I2C_MUX_PCA9547, 0x70, 3}}}, \
2336 {0, {{I2C_MUX_PCA9547, 0x70, 4}}}, \
2337 {0, {{I2C_MUX_PCA9547, 0x70, 5}}}, \
2338 {1, {I2C_NULL_HOP}}, \
2339 {1, {{I2C_MUX_PCA9544, 0x72, 1}}}, \
2340 {1, {{I2C_MUX_PCA9544, 0x72, 2}}}, \
2341 }
2342
2343 which defines
2344 bus 0 on adapter 0 without a mux
2345 bus 1 on adapter 0 with a PCA9547 on address 0x70 port 1
2346 bus 2 on adapter 0 with a PCA9547 on address 0x70 port 2
2347 bus 3 on adapter 0 with a PCA9547 on address 0x70 port 3
2348 bus 4 on adapter 0 with a PCA9547 on address 0x70 port 4
2349 bus 5 on adapter 0 with a PCA9547 on address 0x70 port 5
2350 bus 6 on adapter 1 without a mux
2351 bus 7 on adapter 1 with a PCA9544 on address 0x72 port 1
2352 bus 8 on adapter 1 with a PCA9544 on address 0x72 port 2
2353
2354 If you do not have i2c muxes on your board, omit this define.
2355
2356 - Legacy I2C Support: CONFIG_HARD_I2C
2357
2358 NOTE: It is intended to move drivers to CONFIG_SYS_I2C which
2359 provides the following compelling advantages:
2360
2361 - more than one i2c adapter is usable
2362 - approved multibus support
2363 - better i2c mux support
2364
2365 ** Please consider updating your I2C driver now. **
2366
2367 These enable legacy I2C serial bus commands. Defining
2368 CONFIG_HARD_I2C will include the appropriate I2C driver
2369 for the selected CPU.
2370
2371 This will allow you to use i2c commands at the u-boot
2372 command line (as long as you set CONFIG_CMD_I2C in
2373 CONFIG_COMMANDS) and communicate with i2c based realtime
2374 clock chips. See common/cmd_i2c.c for a description of the
2375 command line interface.
2376
2377 CONFIG_HARD_I2C selects a hardware I2C controller.
2378
2379 There are several other quantities that must also be
2380 defined when you define CONFIG_HARD_I2C.
2381
2382 In both cases you will need to define CONFIG_SYS_I2C_SPEED
2383 to be the frequency (in Hz) at which you wish your i2c bus
2384 to run and CONFIG_SYS_I2C_SLAVE to be the address of this node (ie
2385 the CPU's i2c node address).
2386
2387 Now, the u-boot i2c code for the mpc8xx
2388 (arch/powerpc/cpu/mpc8xx/i2c.c) sets the CPU up as a master node
2389 and so its address should therefore be cleared to 0 (See,
2390 eg, MPC823e User's Manual p.16-473). So, set
2391 CONFIG_SYS_I2C_SLAVE to 0.
2392
2393 CONFIG_SYS_I2C_INIT_MPC5XXX
2394
2395 When a board is reset during an i2c bus transfer
2396 chips might think that the current transfer is still
2397 in progress. Reset the slave devices by sending start
2398 commands until the slave device responds.
2399
2400 That's all that's required for CONFIG_HARD_I2C.
2401
2402 If you use the software i2c interface (CONFIG_SYS_I2C_SOFT)
2403 then the following macros need to be defined (examples are
2404 from include/configs/lwmon.h):
2405
2406 I2C_INIT
2407
2408 (Optional). Any commands necessary to enable the I2C
2409 controller or configure ports.
2410
2411 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
2412
2413 I2C_PORT
2414
2415 (Only for MPC8260 CPU). The I/O port to use (the code
2416 assumes both bits are on the same port). Valid values
2417 are 0..3 for ports A..D.
2418
2419 I2C_ACTIVE
2420
2421 The code necessary to make the I2C data line active
2422 (driven). If the data line is open collector, this
2423 define can be null.
2424
2425 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
2426
2427 I2C_TRISTATE
2428
2429 The code necessary to make the I2C data line tri-stated
2430 (inactive). If the data line is open collector, this
2431 define can be null.
2432
2433 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
2434
2435 I2C_READ
2436
2437 Code that returns true if the I2C data line is high,
2438 false if it is low.
2439
2440 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
2441
2442 I2C_SDA(bit)
2443
2444 If <bit> is true, sets the I2C data line high. If it
2445 is false, it clears it (low).
2446
2447 eg: #define I2C_SDA(bit) \
2448 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
2449 else immr->im_cpm.cp_pbdat &= ~PB_SDA
2450
2451 I2C_SCL(bit)
2452
2453 If <bit> is true, sets the I2C clock line high. If it
2454 is false, it clears it (low).
2455
2456 eg: #define I2C_SCL(bit) \
2457 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
2458 else immr->im_cpm.cp_pbdat &= ~PB_SCL
2459
2460 I2C_DELAY
2461
2462 This delay is invoked four times per clock cycle so this
2463 controls the rate of data transfer. The data rate thus
2464 is 1 / (I2C_DELAY * 4). Often defined to be something
2465 like:
2466
2467 #define I2C_DELAY udelay(2)
2468
2469 CONFIG_SOFT_I2C_GPIO_SCL / CONFIG_SOFT_I2C_GPIO_SDA
2470
2471 If your arch supports the generic GPIO framework (asm/gpio.h),
2472 then you may alternatively define the two GPIOs that are to be
2473 used as SCL / SDA. Any of the previous I2C_xxx macros will
2474 have GPIO-based defaults assigned to them as appropriate.
2475
2476 You should define these to the GPIO value as given directly to
2477 the generic GPIO functions.
2478
2479 CONFIG_SYS_I2C_INIT_BOARD
2480
2481 When a board is reset during an i2c bus transfer
2482 chips might think that the current transfer is still
2483 in progress. On some boards it is possible to access
2484 the i2c SCLK line directly, either by using the
2485 processor pin as a GPIO or by having a second pin
2486 connected to the bus. If this option is defined a
2487 custom i2c_init_board() routine in boards/xxx/board.c
2488 is run early in the boot sequence.
2489
2490 CONFIG_SYS_I2C_BOARD_LATE_INIT
2491
2492 An alternative to CONFIG_SYS_I2C_INIT_BOARD. If this option is
2493 defined a custom i2c_board_late_init() routine in
2494 boards/xxx/board.c is run AFTER the operations in i2c_init()
2495 is completed. This callpoint can be used to unreset i2c bus
2496 using CPU i2c controller register accesses for CPUs whose i2c
2497 controller provide such a method. It is called at the end of
2498 i2c_init() to allow i2c_init operations to setup the i2c bus
2499 controller on the CPU (e.g. setting bus speed & slave address).
2500
2501 CONFIG_I2CFAST (PPC405GP|PPC405EP only)
2502
2503 This option enables configuration of bi_iic_fast[] flags
2504 in u-boot bd_info structure based on u-boot environment
2505 variable "i2cfast". (see also i2cfast)
2506
2507 CONFIG_I2C_MULTI_BUS
2508
2509 This option allows the use of multiple I2C buses, each of which
2510 must have a controller. At any point in time, only one bus is
2511 active. To switch to a different bus, use the 'i2c dev' command.
2512 Note that bus numbering is zero-based.
2513
2514 CONFIG_SYS_I2C_NOPROBES
2515
2516 This option specifies a list of I2C devices that will be skipped
2517 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS
2518 is set, specify a list of bus-device pairs. Otherwise, specify
2519 a 1D array of device addresses
2520
2521 e.g.
2522 #undef CONFIG_I2C_MULTI_BUS
2523 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68}
2524
2525 will skip addresses 0x50 and 0x68 on a board with one I2C bus
2526
2527 #define CONFIG_I2C_MULTI_BUS
2528 #define CONFIG_SYS_I2C_NOPROBES {{0,0x50},{0,0x68},{1,0x54}}
2529
2530 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1
2531
2532 CONFIG_SYS_SPD_BUS_NUM
2533
2534 If defined, then this indicates the I2C bus number for DDR SPD.
2535 If not defined, then U-Boot assumes that SPD is on I2C bus 0.
2536
2537 CONFIG_SYS_RTC_BUS_NUM
2538
2539 If defined, then this indicates the I2C bus number for the RTC.
2540 If not defined, then U-Boot assumes that RTC is on I2C bus 0.
2541
2542 CONFIG_SYS_DTT_BUS_NUM
2543
2544 If defined, then this indicates the I2C bus number for the DTT.
2545 If not defined, then U-Boot assumes that DTT is on I2C bus 0.
2546
2547 CONFIG_SYS_I2C_DTT_ADDR:
2548
2549 If defined, specifies the I2C address of the DTT device.
2550 If not defined, then U-Boot uses predefined value for
2551 specified DTT device.
2552
2553 CONFIG_SOFT_I2C_READ_REPEATED_START
2554
2555 defining this will force the i2c_read() function in
2556 the soft_i2c driver to perform an I2C repeated start
2557 between writing the address pointer and reading the
2558 data. If this define is omitted the default behaviour
2559 of doing a stop-start sequence will be used. Most I2C
2560 devices can use either method, but some require one or
2561 the other.
2562
2563 - SPI Support: CONFIG_SPI
2564
2565 Enables SPI driver (so far only tested with
2566 SPI EEPROM, also an instance works with Crystal A/D and
2567 D/As on the SACSng board)
2568
2569 CONFIG_SH_SPI
2570
2571 Enables the driver for SPI controller on SuperH. Currently
2572 only SH7757 is supported.
2573
2574 CONFIG_SOFT_SPI
2575
2576 Enables a software (bit-bang) SPI driver rather than
2577 using hardware support. This is a general purpose
2578 driver that only requires three general I/O port pins
2579 (two outputs, one input) to function. If this is
2580 defined, the board configuration must define several
2581 SPI configuration items (port pins to use, etc). For
2582 an example, see include/configs/sacsng.h.
2583
2584 CONFIG_HARD_SPI
2585
2586 Enables a hardware SPI driver for general-purpose reads
2587 and writes. As with CONFIG_SOFT_SPI, the board configuration
2588 must define a list of chip-select function pointers.
2589 Currently supported on some MPC8xxx processors. For an
2590 example, see include/configs/mpc8349emds.h.
2591
2592 CONFIG_MXC_SPI
2593
2594 Enables the driver for the SPI controllers on i.MX and MXC
2595 SoCs. Currently i.MX31/35/51 are supported.
2596
2597 CONFIG_SYS_SPI_MXC_WAIT
2598 Timeout for waiting until spi transfer completed.
2599 default: (CONFIG_SYS_HZ/100) /* 10 ms */
2600
2601 - FPGA Support: CONFIG_FPGA
2602
2603 Enables FPGA subsystem.
2604
2605 CONFIG_FPGA_<vendor>
2606
2607 Enables support for specific chip vendors.
2608 (ALTERA, XILINX)
2609
2610 CONFIG_FPGA_<family>
2611
2612 Enables support for FPGA family.
2613 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX)
2614
2615 CONFIG_FPGA_COUNT
2616
2617 Specify the number of FPGA devices to support.
2618
2619 CONFIG_CMD_FPGA_LOADMK
2620
2621 Enable support for fpga loadmk command
2622
2623 CONFIG_CMD_FPGA_LOADP
2624
2625 Enable support for fpga loadp command - load partial bitstream
2626
2627 CONFIG_CMD_FPGA_LOADBP
2628
2629 Enable support for fpga loadbp command - load partial bitstream
2630 (Xilinx only)
2631
2632 CONFIG_SYS_FPGA_PROG_FEEDBACK
2633
2634 Enable printing of hash marks during FPGA configuration.
2635
2636 CONFIG_SYS_FPGA_CHECK_BUSY
2637
2638 Enable checks on FPGA configuration interface busy
2639 status by the configuration function. This option
2640 will require a board or device specific function to
2641 be written.
2642
2643 CONFIG_FPGA_DELAY
2644
2645 If defined, a function that provides delays in the FPGA
2646 configuration driver.
2647
2648 CONFIG_SYS_FPGA_CHECK_CTRLC
2649 Allow Control-C to interrupt FPGA configuration
2650
2651 CONFIG_SYS_FPGA_CHECK_ERROR
2652
2653 Check for configuration errors during FPGA bitfile
2654 loading. For example, abort during Virtex II
2655 configuration if the INIT_B line goes low (which
2656 indicated a CRC error).
2657
2658 CONFIG_SYS_FPGA_WAIT_INIT
2659
2660 Maximum time to wait for the INIT_B line to de-assert
2661 after PROB_B has been de-asserted during a Virtex II
2662 FPGA configuration sequence. The default time is 500
2663 ms.
2664
2665 CONFIG_SYS_FPGA_WAIT_BUSY
2666
2667 Maximum time to wait for BUSY to de-assert during
2668 Virtex II FPGA configuration. The default is 5 ms.
2669
2670 CONFIG_SYS_FPGA_WAIT_CONFIG
2671
2672 Time to wait after FPGA configuration. The default is
2673 200 ms.
2674
2675 - Configuration Management:
2676 CONFIG_BUILD_TARGET
2677
2678 Some SoCs need special image types (e.g. U-Boot binary
2679 with a special header) as build targets. By defining
2680 CONFIG_BUILD_TARGET in the SoC / board header, this
2681 special image will be automatically built upon calling
2682 make / buildman.
2683
2684 CONFIG_IDENT_STRING
2685
2686 If defined, this string will be added to the U-Boot
2687 version information (U_BOOT_VERSION)
2688
2689 - Vendor Parameter Protection:
2690
2691 U-Boot considers the values of the environment
2692 variables "serial#" (Board Serial Number) and
2693 "ethaddr" (Ethernet Address) to be parameters that
2694 are set once by the board vendor / manufacturer, and
2695 protects these variables from casual modification by
2696 the user. Once set, these variables are read-only,
2697 and write or delete attempts are rejected. You can
2698 change this behaviour:
2699
2700 If CONFIG_ENV_OVERWRITE is #defined in your config
2701 file, the write protection for vendor parameters is
2702 completely disabled. Anybody can change or delete
2703 these parameters.
2704
2705 Alternatively, if you define _both_ an ethaddr in the
2706 default env _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
2707 Ethernet address is installed in the environment,
2708 which can be changed exactly ONCE by the user. [The
2709 serial# is unaffected by this, i. e. it remains
2710 read-only.]
2711
2712 The same can be accomplished in a more flexible way
2713 for any variable by configuring the type of access
2714 to allow for those variables in the ".flags" variable
2715 or define CONFIG_ENV_FLAGS_LIST_STATIC.
2716
2717 - Protected RAM:
2718 CONFIG_PRAM
2719
2720 Define this variable to enable the reservation of
2721 "protected RAM", i. e. RAM which is not overwritten
2722 by U-Boot. Define CONFIG_PRAM to hold the number of
2723 kB you want to reserve for pRAM. You can overwrite
2724 this default value by defining an environment
2725 variable "pram" to the number of kB you want to
2726 reserve. Note that the board info structure will
2727 still show the full amount of RAM. If pRAM is
2728 reserved, a new environment variable "mem" will
2729 automatically be defined to hold the amount of
2730 remaining RAM in a form that can be passed as boot
2731 argument to Linux, for instance like that:
2732
2733 setenv bootargs ... mem=\${mem}
2734 saveenv
2735
2736 This way you can tell Linux not to use this memory,
2737 either, which results in a memory region that will
2738 not be affected by reboots.
2739
2740 *WARNING* If your board configuration uses automatic
2741 detection of the RAM size, you must make sure that
2742 this memory test is non-destructive. So far, the
2743 following board configurations are known to be
2744 "pRAM-clean":
2745
2746 IVMS8, IVML24, SPD8xx, TQM8xxL,
2747 HERMES, IP860, RPXlite, LWMON,
2748 FLAGADM, TQM8260
2749
2750 - Access to physical memory region (> 4GB)
2751 Some basic support is provided for operations on memory not
2752 normally accessible to U-Boot - e.g. some architectures
2753 support access to more than 4GB of memory on 32-bit
2754 machines using physical address extension or similar.
2755 Define CONFIG_PHYSMEM to access this basic support, which
2756 currently only supports clearing the memory.
2757
2758 - Error Recovery:
2759 CONFIG_PANIC_HANG
2760
2761 Define this variable to stop the system in case of a
2762 fatal error, so that you have to reset it manually.
2763 This is probably NOT a good idea for an embedded
2764 system where you want the system to reboot
2765 automatically as fast as possible, but it may be
2766 useful during development since you can try to debug
2767 the conditions that lead to the situation.
2768
2769 CONFIG_NET_RETRY_COUNT
2770
2771 This variable defines the number of retries for
2772 network operations like ARP, RARP, TFTP, or BOOTP
2773 before giving up the operation. If not defined, a
2774 default value of 5 is used.
2775
2776 CONFIG_ARP_TIMEOUT
2777
2778 Timeout waiting for an ARP reply in milliseconds.
2779
2780 CONFIG_NFS_TIMEOUT
2781
2782 Timeout in milliseconds used in NFS protocol.
2783 If you encounter "ERROR: Cannot umount" in nfs command,
2784 try longer timeout such as
2785 #define CONFIG_NFS_TIMEOUT 10000UL
2786
2787 - Command Interpreter:
2788 CONFIG_AUTO_COMPLETE
2789
2790 Enable auto completion of commands using TAB.
2791
2792 CONFIG_SYS_PROMPT_HUSH_PS2
2793
2794 This defines the secondary prompt string, which is
2795 printed when the command interpreter needs more input
2796 to complete a command. Usually "> ".
2797
2798 Note:
2799
2800 In the current implementation, the local variables
2801 space and global environment variables space are
2802 separated. Local variables are those you define by
2803 simply typing `name=value'. To access a local
2804 variable later on, you have write `$name' or
2805 `${name}'; to execute the contents of a variable
2806 directly type `$name' at the command prompt.
2807
2808 Global environment variables are those you use
2809 setenv/printenv to work with. To run a command stored
2810 in such a variable, you need to use the run command,
2811 and you must not use the '$' sign to access them.
2812
2813 To store commands and special characters in a
2814 variable, please use double quotation marks
2815 surrounding the whole text of the variable, instead
2816 of the backslashes before semicolons and special
2817 symbols.
2818
2819 - Command Line Editing and History:
2820 CONFIG_CMDLINE_EDITING
2821
2822 Enable editing and History functions for interactive
2823 command line input operations
2824
2825 - Command Line PS1/PS2 support:
2826 CONFIG_CMDLINE_PS_SUPPORT
2827
2828 Enable support for changing the command prompt string
2829 at run-time. Only static string is supported so far.
2830 The string is obtained from environment variables PS1
2831 and PS2.
2832
2833 - Default Environment:
2834 CONFIG_EXTRA_ENV_SETTINGS
2835
2836 Define this to contain any number of null terminated
2837 strings (variable = value pairs) that will be part of
2838 the default environment compiled into the boot image.
2839
2840 For example, place something like this in your
2841 board's config file:
2842
2843 #define CONFIG_EXTRA_ENV_SETTINGS \
2844 "myvar1=value1\0" \
2845 "myvar2=value2\0"
2846
2847 Warning: This method is based on knowledge about the
2848 internal format how the environment is stored by the
2849 U-Boot code. This is NOT an official, exported
2850 interface! Although it is unlikely that this format
2851 will change soon, there is no guarantee either.
2852 You better know what you are doing here.
2853
2854 Note: overly (ab)use of the default environment is
2855 discouraged. Make sure to check other ways to preset
2856 the environment like the "source" command or the
2857 boot command first.
2858
2859 CONFIG_ENV_VARS_UBOOT_CONFIG
2860
2861 Define this in order to add variables describing the
2862 U-Boot build configuration to the default environment.
2863 These will be named arch, cpu, board, vendor, and soc.
2864
2865 Enabling this option will cause the following to be defined:
2866
2867 - CONFIG_SYS_ARCH
2868 - CONFIG_SYS_CPU
2869 - CONFIG_SYS_BOARD
2870 - CONFIG_SYS_VENDOR
2871 - CONFIG_SYS_SOC
2872
2873 CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG
2874
2875 Define this in order to add variables describing certain
2876 run-time determined information about the hardware to the
2877 environment. These will be named board_name, board_rev.
2878
2879 CONFIG_DELAY_ENVIRONMENT
2880
2881 Normally the environment is loaded when the board is
2882 initialised so that it is available to U-Boot. This inhibits
2883 that so that the environment is not available until
2884 explicitly loaded later by U-Boot code. With CONFIG_OF_CONTROL
2885 this is instead controlled by the value of
2886 /config/load-environment.
2887
2888 - Parallel Flash support:
2889 CONFIG_SYS_NO_FLASH
2890
2891 Traditionally U-Boot was run on systems with parallel NOR
2892 flash. This option is used to disable support for parallel NOR
2893 flash. This option should be defined if the board does not have
2894 parallel flash.
2895
2896 If this option is not defined one of the generic flash drivers
2897 (e.g. CONFIG_FLASH_CFI_DRIVER or CONFIG_ST_SMI) must be
2898 selected or the board must provide an implementation of the
2899 flash API (see include/flash.h).
2900
2901 - DataFlash Support:
2902 CONFIG_HAS_DATAFLASH
2903
2904 Defining this option enables DataFlash features and
2905 allows to read/write in Dataflash via the standard
2906 commands cp, md...
2907
2908 - Serial Flash support
2909 CONFIG_CMD_SF
2910
2911 Defining this option enables SPI flash commands
2912 'sf probe/read/write/erase/update'.
2913
2914 Usage requires an initial 'probe' to define the serial
2915 flash parameters, followed by read/write/erase/update
2916 commands.
2917
2918 The following defaults may be provided by the platform
2919 to handle the common case when only a single serial
2920 flash is present on the system.
2921
2922 CONFIG_SF_DEFAULT_BUS Bus identifier
2923 CONFIG_SF_DEFAULT_CS Chip-select
2924 CONFIG_SF_DEFAULT_MODE (see include/spi.h)
2925 CONFIG_SF_DEFAULT_SPEED in Hz
2926
2927 CONFIG_CMD_SF_TEST
2928
2929 Define this option to include a destructive SPI flash
2930 test ('sf test').
2931
2932 CONFIG_SF_DUAL_FLASH Dual flash memories
2933
2934 Define this option to use dual flash support where two flash
2935 memories can be connected with a given cs line.
2936 Currently Xilinx Zynq qspi supports these type of connections.
2937
2938 - SystemACE Support:
2939 CONFIG_SYSTEMACE
2940
2941 Adding this option adds support for Xilinx SystemACE
2942 chips attached via some sort of local bus. The address
2943 of the chip must also be defined in the
2944 CONFIG_SYS_SYSTEMACE_BASE macro. For example:
2945
2946 #define CONFIG_SYSTEMACE
2947 #define CONFIG_SYS_SYSTEMACE_BASE 0xf0000000
2948
2949 When SystemACE support is added, the "ace" device type
2950 becomes available to the fat commands, i.e. fatls.
2951
2952 - TFTP Fixed UDP Port:
2953 CONFIG_TFTP_PORT
2954
2955 If this is defined, the environment variable tftpsrcp
2956 is used to supply the TFTP UDP source port value.
2957 If tftpsrcp isn't defined, the normal pseudo-random port
2958 number generator is used.
2959
2960 Also, the environment variable tftpdstp is used to supply
2961 the TFTP UDP destination port value. If tftpdstp isn't
2962 defined, the normal port 69 is used.
2963
2964 The purpose for tftpsrcp is to allow a TFTP server to
2965 blindly start the TFTP transfer using the pre-configured
2966 target IP address and UDP port. This has the effect of
2967 "punching through" the (Windows XP) firewall, allowing
2968 the remainder of the TFTP transfer to proceed normally.
2969 A better solution is to properly configure the firewall,
2970 but sometimes that is not allowed.
2971
2972 - Hashing support:
2973 CONFIG_CMD_HASH
2974
2975 This enables a generic 'hash' command which can produce
2976 hashes / digests from a few algorithms (e.g. SHA1, SHA256).
2977
2978 CONFIG_HASH_VERIFY
2979
2980 Enable the hash verify command (hash -v). This adds to code
2981 size a little.
2982
2983 CONFIG_SHA1 - This option enables support of hashing using SHA1
2984 algorithm. The hash is calculated in software.
2985 CONFIG_SHA256 - This option enables support of hashing using
2986 SHA256 algorithm. The hash is calculated in software.
2987 CONFIG_SHA_HW_ACCEL - This option enables hardware acceleration
2988 for SHA1/SHA256 hashing.
2989 This affects the 'hash' command and also the
2990 hash_lookup_algo() function.
2991 CONFIG_SHA_PROG_HW_ACCEL - This option enables
2992 hardware-acceleration for SHA1/SHA256 progressive hashing.
2993 Data can be streamed in a block at a time and the hashing
2994 is performed in hardware.
2995
2996 Note: There is also a sha1sum command, which should perhaps
2997 be deprecated in favour of 'hash sha1'.
2998
2999 - Freescale i.MX specific commands:
3000 CONFIG_CMD_HDMIDETECT
3001 This enables 'hdmidet' command which returns true if an
3002 HDMI monitor is detected. This command is i.MX 6 specific.
3003
3004 CONFIG_CMD_BMODE
3005 This enables the 'bmode' (bootmode) command for forcing
3006 a boot from specific media.
3007
3008 This is useful for forcing the ROM's usb downloader to
3009 activate upon a watchdog reset which is nice when iterating
3010 on U-Boot. Using the reset button or running bmode normal
3011 will set it back to normal. This command currently
3012 supports i.MX53 and i.MX6.
3013
3014 - bootcount support:
3015 CONFIG_BOOTCOUNT_LIMIT
3016
3017 This enables the bootcounter support, see:
3018 http://www.denx.de/wiki/DULG/UBootBootCountLimit
3019
3020 CONFIG_AT91SAM9XE
3021 enable special bootcounter support on at91sam9xe based boards.
3022 CONFIG_BLACKFIN
3023 enable special bootcounter support on blackfin based boards.
3024 CONFIG_SOC_DA8XX
3025 enable special bootcounter support on da850 based boards.
3026 CONFIG_BOOTCOUNT_RAM
3027 enable support for the bootcounter in RAM
3028 CONFIG_BOOTCOUNT_I2C
3029 enable support for the bootcounter on an i2c (like RTC) device.
3030 CONFIG_SYS_I2C_RTC_ADDR = i2c chip address
3031 CONFIG_SYS_BOOTCOUNT_ADDR = i2c addr which is used for
3032 the bootcounter.
3033 CONFIG_BOOTCOUNT_ALEN = address len
3034
3035 - Show boot progress:
3036 CONFIG_SHOW_BOOT_PROGRESS
3037
3038 Defining this option allows to add some board-
3039 specific code (calling a user-provided function
3040 "show_boot_progress(int)") that enables you to show
3041 the system's boot progress on some display (for
3042 example, some LED's) on your board. At the moment,
3043 the following checkpoints are implemented:
3044
3045
3046 Legacy uImage format:
3047
3048 Arg Where When
3049 1 common/cmd_bootm.c before attempting to boot an image
3050 -1 common/cmd_bootm.c Image header has bad magic number
3051 2 common/cmd_bootm.c Image header has correct magic number
3052 -2 common/cmd_bootm.c Image header has bad checksum
3053 3 common/cmd_bootm.c Image header has correct checksum
3054 -3 common/cmd_bootm.c Image data has bad checksum
3055 4 common/cmd_bootm.c Image data has correct checksum
3056 -4 common/cmd_bootm.c Image is for unsupported architecture
3057 5 common/cmd_bootm.c Architecture check OK
3058 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi)
3059 6 common/cmd_bootm.c Image Type check OK
3060 -6 common/cmd_bootm.c gunzip uncompression error
3061 -7 common/cmd_bootm.c Unimplemented compression type
3062 7 common/cmd_bootm.c Uncompression OK
3063 8 common/cmd_bootm.c No uncompress/copy overwrite error
3064 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX)
3065
3066 9 common/image.c Start initial ramdisk verification
3067 -10 common/image.c Ramdisk header has bad magic number
3068 -11 common/image.c Ramdisk header has bad checksum
3069 10 common/image.c Ramdisk header is OK
3070 -12 common/image.c Ramdisk data has bad checksum
3071 11 common/image.c Ramdisk data has correct checksum
3072 12 common/image.c Ramdisk verification complete, start loading
3073 -13 common/image.c Wrong Image Type (not PPC Linux ramdisk)
3074 13 common/image.c Start multifile image verification
3075 14 common/image.c No initial ramdisk, no multifile, continue.
3076
3077 15 arch/<arch>/lib/bootm.c All preparation done, transferring control to OS
3078
3079 -30 arch/powerpc/lib/board.c Fatal error, hang the system
3080 -31 post/post.c POST test failed, detected by post_output_backlog()
3081 -32 post/post.c POST test failed, detected by post_run_single()
3082
3083 34 common/cmd_doc.c before loading a Image from a DOC device
3084 -35 common/cmd_doc.c Bad usage of "doc" command
3085 35 common/cmd_doc.c correct usage of "doc" command
3086 -36 common/cmd_doc.c No boot device
3087 36 common/cmd_doc.c correct boot device
3088 -37 common/cmd_doc.c Unknown Chip ID on boot device
3089 37 common/cmd_doc.c correct chip ID found, device available
3090 -38 common/cmd_doc.c Read Error on boot device
3091 38 common/cmd_doc.c reading Image header from DOC device OK
3092 -39 common/cmd_doc.c Image header has bad magic number
3093 39 common/cmd_doc.c Image header has correct magic number
3094 -40 common/cmd_doc.c Error reading Image from DOC device
3095 40 common/cmd_doc.c Image header has correct magic number
3096 41 common/cmd_ide.c before loading a Image from a IDE device
3097 -42 common/cmd_ide.c Bad usage of "ide" command
3098 42 common/cmd_ide.c correct usage of "ide" command
3099 -43 common/cmd_ide.c No boot device
3100 43 common/cmd_ide.c boot device found
3101 -44 common/cmd_ide.c Device not available
3102 44 common/cmd_ide.c Device available
3103 -45 common/cmd_ide.c wrong partition selected
3104 45 common/cmd_ide.c partition selected
3105 -46 common/cmd_ide.c Unknown partition table
3106 46 common/cmd_ide.c valid partition table found
3107 -47 common/cmd_ide.c Invalid partition type
3108 47 common/cmd_ide.c correct partition type
3109 -48 common/cmd_ide.c Error reading Image Header on boot device
3110 48 common/cmd_ide.c reading Image Header from IDE device OK
3111 -49 common/cmd_ide.c Image header has bad magic number
3112 49 common/cmd_ide.c Image header has correct magic number
3113 -50 common/cmd_ide.c Image header has bad checksum
3114 50 common/cmd_ide.c Image header has correct checksum
3115 -51 common/cmd_ide.c Error reading Image from IDE device
3116 51 common/cmd_ide.c reading Image from IDE device OK
3117 52 common/cmd_nand.c before loading a Image from a NAND device
3118 -53 common/cmd_nand.c Bad usage of "nand" command
3119 53 common/cmd_nand.c correct usage of "nand" command
3120 -54 common/cmd_nand.c No boot device
3121 54 common/cmd_nand.c boot device found
3122 -55 common/cmd_nand.c Unknown Chip ID on boot device
3123 55 common/cmd_nand.c correct chip ID found, device available
3124 -56 common/cmd_nand.c Error reading Image Header on boot device
3125 56 common/cmd_nand.c reading Image Header from NAND device OK
3126 -57 common/cmd_nand.c Image header has bad magic number
3127 57 common/cmd_nand.c Image header has correct magic number
3128 -58 common/cmd_nand.c Error reading Image from NAND device
3129 58 common/cmd_nand.c reading Image from NAND device OK
3130
3131 -60 common/env_common.c Environment has a bad CRC, using default
3132
3133 64 net/eth.c starting with Ethernet configuration.
3134 -64 net/eth.c no Ethernet found.
3135 65 net/eth.c Ethernet found.
3136
3137 -80 common/cmd_net.c usage wrong
3138 80 common/cmd_net.c before calling net_loop()
3139 -81 common/cmd_net.c some error in net_loop() occurred
3140 81 common/cmd_net.c net_loop() back without error
3141 -82 common/cmd_net.c size == 0 (File with size 0 loaded)
3142 82 common/cmd_net.c trying automatic boot
3143 83 common/cmd_net.c running "source" command
3144 -83 common/cmd_net.c some error in automatic boot or "source" command
3145 84 common/cmd_net.c end without errors
3146
3147 FIT uImage format:
3148
3149 Arg Where When
3150 100 common/cmd_bootm.c Kernel FIT Image has correct format
3151 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format
3152 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration
3153 -101 common/cmd_bootm.c Can't get configuration for kernel subimage
3154 102 common/cmd_bootm.c Kernel unit name specified
3155 -103 common/cmd_bootm.c Can't get kernel subimage node offset
3156 103 common/cmd_bootm.c Found configuration node
3157 104 common/cmd_bootm.c Got kernel subimage node offset
3158 -104 common/cmd_bootm.c Kernel subimage hash verification failed
3159 105 common/cmd_bootm.c Kernel subimage hash verification OK
3160 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture
3161 106 common/cmd_bootm.c Architecture check OK
3162 -106 common/cmd_bootm.c Kernel subimage has wrong type
3163 107 common/cmd_bootm.c Kernel subimage type OK
3164 -107 common/cmd_bootm.c Can't get kernel subimage data/size
3165 108 common/cmd_bootm.c Got kernel subimage data/size
3166 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT)
3167 -109 common/cmd_bootm.c Can't get kernel subimage type
3168 -110 common/cmd_bootm.c Can't get kernel subimage comp
3169 -111 common/cmd_bootm.c Can't get kernel subimage os
3170 -112 common/cmd_bootm.c Can't get kernel subimage load address
3171 -113 common/cmd_bootm.c Image uncompress/copy overwrite error
3172
3173 120 common/image.c Start initial ramdisk verification
3174 -120 common/image.c Ramdisk FIT image has incorrect format
3175 121 common/image.c Ramdisk FIT image has correct format
3176 122 common/image.c No ramdisk subimage unit name, using configuration
3177 -122 common/image.c Can't get configuration for ramdisk subimage
3178 123 common/image.c Ramdisk unit name specified
3179 -124 common/image.c Can't get ramdisk subimage node offset
3180 125 common/image.c Got ramdisk subimage node offset
3181 -125 common/image.c Ramdisk subimage hash verification failed
3182 126 common/image.c Ramdisk subimage hash verification OK
3183 -126 common/image.c Ramdisk subimage for unsupported architecture
3184 127 common/image.c Architecture check OK
3185 -127 common/image.c Can't get ramdisk subimage data/size
3186 128 common/image.c Got ramdisk subimage data/size
3187 129 common/image.c Can't get ramdisk load address
3188 -129 common/image.c Got ramdisk load address
3189
3190 -130 common/cmd_doc.c Incorrect FIT image format
3191 131 common/cmd_doc.c FIT image format OK
3192
3193 -140 common/cmd_ide.c Incorrect FIT image format
3194 141 common/cmd_ide.c FIT image format OK
3195
3196 -150 common/cmd_nand.c Incorrect FIT image format
3197 151 common/cmd_nand.c FIT image format OK
3198
3199 - legacy image format:
3200 CONFIG_IMAGE_FORMAT_LEGACY
3201 enables the legacy image format support in U-Boot.
3202
3203 Default:
3204 enabled if CONFIG_FIT_SIGNATURE is not defined.
3205
3206 CONFIG_DISABLE_IMAGE_LEGACY
3207 disable the legacy image format
3208
3209 This define is introduced, as the legacy image format is
3210 enabled per default for backward compatibility.
3211
3212 - FIT image support:
3213 CONFIG_FIT_DISABLE_SHA256
3214 Supporting SHA256 hashes has quite an impact on binary size.
3215 For constrained systems sha256 hash support can be disabled
3216 with this option.
3217
3218 TODO(sjg@chromium.org): Adjust this option to be positive,
3219 and move it to Kconfig
3220
3221 - Standalone program support:
3222 CONFIG_STANDALONE_LOAD_ADDR
3223
3224 This option defines a board specific value for the
3225 address where standalone program gets loaded, thus
3226 overwriting the architecture dependent default
3227 settings.
3228
3229 - Frame Buffer Address:
3230 CONFIG_FB_ADDR
3231
3232 Define CONFIG_FB_ADDR if you want to use specific
3233 address for frame buffer. This is typically the case
3234 when using a graphics controller has separate video
3235 memory. U-Boot will then place the frame buffer at
3236 the given address instead of dynamically reserving it
3237 in system RAM by calling lcd_setmem(), which grabs
3238 the memory for the frame buffer depending on the
3239 configured panel size.
3240
3241 Please see board_init_f function.
3242
3243 - Automatic software updates via TFTP server
3244 CONFIG_UPDATE_TFTP
3245 CONFIG_UPDATE_TFTP_CNT_MAX
3246 CONFIG_UPDATE_TFTP_MSEC_MAX
3247
3248 These options enable and control the auto-update feature;
3249 for a more detailed description refer to doc/README.update.
3250
3251 - MTD Support (mtdparts command, UBI support)
3252 CONFIG_MTD_DEVICE
3253
3254 Adds the MTD device infrastructure from the Linux kernel.
3255 Needed for mtdparts command support.
3256
3257 CONFIG_MTD_PARTITIONS
3258
3259 Adds the MTD partitioning infrastructure from the Linux
3260 kernel. Needed for UBI support.
3261
3262 - UBI support
3263 CONFIG_CMD_UBI
3264
3265 Adds commands for interacting with MTD partitions formatted
3266 with the UBI flash translation layer
3267
3268 Requires also defining CONFIG_RBTREE
3269
3270 CONFIG_UBI_SILENCE_MSG
3271
3272 Make the verbose messages from UBI stop printing. This leaves
3273 warnings and errors enabled.
3274
3275
3276 CONFIG_MTD_UBI_WL_THRESHOLD
3277 This parameter defines the maximum difference between the highest
3278 erase counter value and the lowest erase counter value of eraseblocks
3279 of UBI devices. When this threshold is exceeded, UBI starts performing
3280 wear leveling by means of moving data from eraseblock with low erase
3281 counter to eraseblocks with high erase counter.
3282
3283 The default value should be OK for SLC NAND flashes, NOR flashes and
3284 other flashes which have eraseblock life-cycle 100000 or more.
3285 However, in case of MLC NAND flashes which typically have eraseblock
3286 life-cycle less than 10000, the threshold should be lessened (e.g.,
3287 to 128 or 256, although it does not have to be power of 2).
3288
3289 default: 4096
3290
3291 CONFIG_MTD_UBI_BEB_LIMIT
3292 This option specifies the maximum bad physical eraseblocks UBI
3293 expects on the MTD device (per 1024 eraseblocks). If the
3294 underlying flash does not admit of bad eraseblocks (e.g. NOR
3295 flash), this value is ignored.
3296
3297 NAND datasheets often specify the minimum and maximum NVM
3298 (Number of Valid Blocks) for the flashes' endurance lifetime.
3299 The maximum expected bad eraseblocks per 1024 eraseblocks
3300 then can be calculated as "1024 * (1 - MinNVB / MaxNVB)",
3301 which gives 20 for most NANDs (MaxNVB is basically the total
3302 count of eraseblocks on the chip).
3303
3304 To put it differently, if this value is 20, UBI will try to
3305 reserve about 1.9% of physical eraseblocks for bad blocks
3306 handling. And that will be 1.9% of eraseblocks on the entire
3307 NAND chip, not just the MTD partition UBI attaches. This means
3308 that if you have, say, a NAND flash chip admits maximum 40 bad
3309 eraseblocks, and it is split on two MTD partitions of the same
3310 size, UBI will reserve 40 eraseblocks when attaching a
3311 partition.
3312
3313 default: 20
3314
3315 CONFIG_MTD_UBI_FASTMAP
3316 Fastmap is a mechanism which allows attaching an UBI device
3317 in nearly constant time. Instead of scanning the whole MTD device it
3318 only has to locate a checkpoint (called fastmap) on the device.
3319 The on-flash fastmap contains all information needed to attach
3320 the device. Using fastmap makes only sense on large devices where
3321 attaching by scanning takes long. UBI will not automatically install
3322 a fastmap on old images, but you can set the UBI parameter
3323 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT to 1 if you want so. Please note
3324 that fastmap-enabled images are still usable with UBI implementations
3325 without fastmap support. On typical flash devices the whole fastmap
3326 fits into one PEB. UBI will reserve PEBs to hold two fastmaps.
3327
3328 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT
3329 Set this parameter to enable fastmap automatically on images
3330 without a fastmap.
3331 default: 0
3332
3333 CONFIG_MTD_UBI_FM_DEBUG
3334 Enable UBI fastmap debug
3335 default: 0
3336
3337 - UBIFS support
3338 CONFIG_CMD_UBIFS
3339
3340 Adds commands for interacting with UBI volumes formatted as
3341 UBIFS. UBIFS is read-only in u-boot.
3342
3343 Requires UBI support as well as CONFIG_LZO
3344
3345 CONFIG_UBIFS_SILENCE_MSG
3346
3347 Make the verbose messages from UBIFS stop printing. This leaves
3348 warnings and errors enabled.
3349
3350 - SPL framework
3351 CONFIG_SPL
3352 Enable building of SPL globally.
3353
3354 CONFIG_SPL_LDSCRIPT
3355 LDSCRIPT for linking the SPL binary.
3356
3357 CONFIG_SPL_MAX_FOOTPRINT
3358 Maximum size in memory allocated to the SPL, BSS included.
3359 When defined, the linker checks that the actual memory
3360 used by SPL from _start to __bss_end does not exceed it.
3361 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
3362 must not be both defined at the same time.
3363
3364 CONFIG_SPL_MAX_SIZE
3365 Maximum size of the SPL image (text, data, rodata, and
3366 linker lists sections), BSS excluded.
3367 When defined, the linker checks that the actual size does
3368 not exceed it.
3369
3370 CONFIG_SPL_TEXT_BASE
3371 TEXT_BASE for linking the SPL binary.
3372
3373 CONFIG_SPL_RELOC_TEXT_BASE
3374 Address to relocate to. If unspecified, this is equal to
3375 CONFIG_SPL_TEXT_BASE (i.e. no relocation is done).
3376
3377 CONFIG_SPL_BSS_START_ADDR
3378 Link address for the BSS within the SPL binary.
3379
3380 CONFIG_SPL_BSS_MAX_SIZE
3381 Maximum size in memory allocated to the SPL BSS.
3382 When defined, the linker checks that the actual memory used
3383 by SPL from __bss_start to __bss_end does not exceed it.
3384 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
3385 must not be both defined at the same time.
3386
3387 CONFIG_SPL_STACK
3388 Adress of the start of the stack SPL will use
3389
3390 CONFIG_SPL_PANIC_ON_RAW_IMAGE
3391 When defined, SPL will panic() if the image it has
3392 loaded does not have a signature.
3393 Defining this is useful when code which loads images
3394 in SPL cannot guarantee that absolutely all read errors
3395 will be caught.
3396 An example is the LPC32XX MLC NAND driver, which will
3397 consider that a completely unreadable NAND block is bad,
3398 and thus should be skipped silently.
3399
3400 CONFIG_SPL_ABORT_ON_RAW_IMAGE
3401 When defined, SPL will proceed to another boot method
3402 if the image it has loaded does not have a signature.
3403
3404 CONFIG_SPL_RELOC_STACK
3405 Adress of the start of the stack SPL will use after
3406 relocation. If unspecified, this is equal to
3407 CONFIG_SPL_STACK.
3408
3409 CONFIG_SYS_SPL_MALLOC_START
3410 Starting address of the malloc pool used in SPL.
3411 When this option is set the full malloc is used in SPL and
3412 it is set up by spl_init() and before that, the simple malloc()
3413 can be used if CONFIG_SYS_MALLOC_F is defined.
3414
3415 CONFIG_SYS_SPL_MALLOC_SIZE
3416 The size of the malloc pool used in SPL.
3417
3418 CONFIG_SPL_FRAMEWORK
3419 Enable the SPL framework under common/. This framework
3420 supports MMC, NAND and YMODEM loading of U-Boot and NAND
3421 NAND loading of the Linux Kernel.
3422
3423 CONFIG_SPL_OS_BOOT
3424 Enable booting directly to an OS from SPL.
3425 See also: doc/README.falcon
3426
3427 CONFIG_SPL_DISPLAY_PRINT
3428 For ARM, enable an optional function to print more information
3429 about the running system.
3430
3431 CONFIG_SPL_INIT_MINIMAL
3432 Arch init code should be built for a very small image
3433
3434 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_SECTOR,
3435 CONFIG_SYS_U_BOOT_MAX_SIZE_SECTORS,
3436 Address and partition on the MMC to load U-Boot from
3437 when the MMC is being used in raw mode.
3438
3439 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_PARTITION
3440 Partition on the MMC to load U-Boot from when the MMC is being
3441 used in raw mode
3442
3443 CONFIG_SYS_MMCSD_RAW_MODE_KERNEL_SECTOR
3444 Sector to load kernel uImage from when MMC is being
3445 used in raw mode (for Falcon mode)
3446
3447 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTOR,
3448 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTORS
3449 Sector and number of sectors to load kernel argument
3450 parameters from when MMC is being used in raw mode
3451 (for falcon mode)
3452
3453 CONFIG_SYS_MMCSD_FS_BOOT_PARTITION
3454 Partition on the MMC to load U-Boot from when the MMC is being
3455 used in fs mode
3456
3457 CONFIG_SPL_FS_LOAD_PAYLOAD_NAME
3458 Filename to read to load U-Boot when reading from filesystem
3459
3460 CONFIG_SPL_FS_LOAD_KERNEL_NAME
3461 Filename to read to load kernel uImage when reading
3462 from filesystem (for Falcon mode)
3463
3464 CONFIG_SPL_FS_LOAD_ARGS_NAME
3465 Filename to read to load kernel argument parameters
3466 when reading from filesystem (for Falcon mode)
3467
3468 CONFIG_SPL_MPC83XX_WAIT_FOR_NAND
3469 Set this for NAND SPL on PPC mpc83xx targets, so that
3470 start.S waits for the rest of the SPL to load before
3471 continuing (the hardware starts execution after just
3472 loading the first page rather than the full 4K).
3473
3474 CONFIG_SPL_SKIP_RELOCATE
3475 Avoid SPL relocation
3476
3477 CONFIG_SPL_NAND_BASE
3478 Include nand_base.c in the SPL. Requires
3479 CONFIG_SPL_NAND_DRIVERS.
3480
3481 CONFIG_SPL_NAND_DRIVERS
3482 SPL uses normal NAND drivers, not minimal drivers.
3483
3484 CONFIG_SPL_NAND_ECC
3485 Include standard software ECC in the SPL
3486
3487 CONFIG_SPL_NAND_SIMPLE
3488 Support for NAND boot using simple NAND drivers that
3489 expose the cmd_ctrl() interface.
3490
3491 CONFIG_SPL_UBI
3492 Support for a lightweight UBI (fastmap) scanner and
3493 loader
3494
3495 CONFIG_SPL_NAND_RAW_ONLY
3496 Support to boot only raw u-boot.bin images. Use this only
3497 if you need to save space.
3498
3499 CONFIG_SPL_COMMON_INIT_DDR
3500 Set for common ddr init with serial presence detect in
3501 SPL binary.
3502
3503 CONFIG_SYS_NAND_5_ADDR_CYCLE, CONFIG_SYS_NAND_PAGE_COUNT,
3504 CONFIG_SYS_NAND_PAGE_SIZE, CONFIG_SYS_NAND_OOBSIZE,
3505 CONFIG_SYS_NAND_BLOCK_SIZE, CONFIG_SYS_NAND_BAD_BLOCK_POS,
3506 CONFIG_SYS_NAND_ECCPOS, CONFIG_SYS_NAND_ECCSIZE,
3507 CONFIG_SYS_NAND_ECCBYTES
3508 Defines the size and behavior of the NAND that SPL uses
3509 to read U-Boot
3510
3511 CONFIG_SPL_NAND_BOOT
3512 Add support NAND boot
3513
3514 CONFIG_SYS_NAND_U_BOOT_OFFS
3515 Location in NAND to read U-Boot from
3516
3517 CONFIG_SYS_NAND_U_BOOT_DST
3518 Location in memory to load U-Boot to
3519
3520 CONFIG_SYS_NAND_U_BOOT_SIZE
3521 Size of image to load
3522
3523 CONFIG_SYS_NAND_U_BOOT_START
3524 Entry point in loaded image to jump to
3525
3526 CONFIG_SYS_NAND_HW_ECC_OOBFIRST
3527 Define this if you need to first read the OOB and then the
3528 data. This is used, for example, on davinci platforms.
3529
3530 CONFIG_SPL_OMAP3_ID_NAND
3531 Support for an OMAP3-specific set of functions to return the
3532 ID and MFR of the first attached NAND chip, if present.
3533
3534 CONFIG_SPL_RAM_DEVICE
3535 Support for running image already present in ram, in SPL binary
3536
3537 CONFIG_SPL_PAD_TO
3538 Image offset to which the SPL should be padded before appending
3539 the SPL payload. By default, this is defined as
3540 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3541 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3542 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3543
3544 CONFIG_SPL_TARGET
3545 Final target image containing SPL and payload. Some SPLs
3546 use an arch-specific makefile fragment instead, for
3547 example if more than one image needs to be produced.
3548
3549 CONFIG_FIT_SPL_PRINT
3550 Printing information about a FIT image adds quite a bit of
3551 code to SPL. So this is normally disabled in SPL. Use this
3552 option to re-enable it. This will affect the output of the
3553 bootm command when booting a FIT image.
3554
3555 - TPL framework
3556 CONFIG_TPL
3557 Enable building of TPL globally.
3558
3559 CONFIG_TPL_PAD_TO
3560 Image offset to which the TPL should be padded before appending
3561 the TPL payload. By default, this is defined as
3562 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3563 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3564 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3565
3566 - Interrupt support (PPC):
3567
3568 There are common interrupt_init() and timer_interrupt()
3569 for all PPC archs. interrupt_init() calls interrupt_init_cpu()
3570 for CPU specific initialization. interrupt_init_cpu()
3571 should set decrementer_count to appropriate value. If
3572 CPU resets decrementer automatically after interrupt
3573 (ppc4xx) it should set decrementer_count to zero.
3574 timer_interrupt() calls timer_interrupt_cpu() for CPU
3575 specific handling. If board has watchdog / status_led
3576 / other_activity_monitor it works automatically from
3577 general timer_interrupt().
3578
3579
3580 Board initialization settings:
3581 ------------------------------
3582
3583 During Initialization u-boot calls a number of board specific functions
3584 to allow the preparation of board specific prerequisites, e.g. pin setup
3585 before drivers are initialized. To enable these callbacks the
3586 following configuration macros have to be defined. Currently this is
3587 architecture specific, so please check arch/your_architecture/lib/board.c
3588 typically in board_init_f() and board_init_r().
3589
3590 - CONFIG_BOARD_EARLY_INIT_F: Call board_early_init_f()
3591 - CONFIG_BOARD_EARLY_INIT_R: Call board_early_init_r()
3592 - CONFIG_BOARD_LATE_INIT: Call board_late_init()
3593 - CONFIG_BOARD_POSTCLK_INIT: Call board_postclk_init()
3594
3595 Configuration Settings:
3596 -----------------------
3597
3598 - CONFIG_SYS_SUPPORT_64BIT_DATA: Defined automatically if compiled as 64-bit.
3599 Optionally it can be defined to support 64-bit memory commands.
3600
3601 - CONFIG_SYS_LONGHELP: Defined when you want long help messages included;
3602 undefine this when you're short of memory.
3603
3604 - CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default
3605 width of the commands listed in the 'help' command output.
3606
3607 - CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to
3608 prompt for user input.
3609
3610 - CONFIG_SYS_CBSIZE: Buffer size for input from the Console
3611
3612 - CONFIG_SYS_PBSIZE: Buffer size for Console output
3613
3614 - CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands
3615
3616 - CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to
3617 the application (usually a Linux kernel) when it is
3618 booted
3619
3620 - CONFIG_SYS_BAUDRATE_TABLE:
3621 List of legal baudrate settings for this board.
3622
3623 - CONFIG_SYS_CONSOLE_INFO_QUIET
3624 Suppress display of console information at boot.
3625
3626 - CONFIG_SYS_CONSOLE_IS_IN_ENV
3627 If the board specific function
3628 extern int overwrite_console (void);
3629 returns 1, the stdin, stderr and stdout are switched to the
3630 serial port, else the settings in the environment are used.
3631
3632 - CONFIG_SYS_CONSOLE_OVERWRITE_ROUTINE
3633 Enable the call to overwrite_console().
3634
3635 - CONFIG_SYS_CONSOLE_ENV_OVERWRITE
3636 Enable overwrite of previous console environment settings.
3637
3638 - CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END:
3639 Begin and End addresses of the area used by the
3640 simple memory test.
3641
3642 - CONFIG_SYS_ALT_MEMTEST:
3643 Enable an alternate, more extensive memory test.
3644
3645 - CONFIG_SYS_MEMTEST_SCRATCH:
3646 Scratch address used by the alternate memory test
3647 You only need to set this if address zero isn't writeable
3648
3649 - CONFIG_SYS_MEM_RESERVE_SECURE
3650 Only implemented for ARMv8 for now.
3651 If defined, the size of CONFIG_SYS_MEM_RESERVE_SECURE memory
3652 is substracted from total RAM and won't be reported to OS.
3653 This memory can be used as secure memory. A variable
3654 gd->arch.secure_ram is used to track the location. In systems
3655 the RAM base is not zero, or RAM is divided into banks,
3656 this variable needs to be recalcuated to get the address.
3657
3658 - CONFIG_SYS_MEM_TOP_HIDE:
3659 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header,
3660 this specified memory area will get subtracted from the top
3661 (end) of RAM and won't get "touched" at all by U-Boot. By
3662 fixing up gd->ram_size the Linux kernel should gets passed
3663 the now "corrected" memory size and won't touch it either.
3664 This should work for arch/ppc and arch/powerpc. Only Linux
3665 board ports in arch/powerpc with bootwrapper support that
3666 recalculate the memory size from the SDRAM controller setup
3667 will have to get fixed in Linux additionally.
3668
3669 This option can be used as a workaround for the 440EPx/GRx
3670 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't
3671 be touched.
3672
3673 WARNING: Please make sure that this value is a multiple of
3674 the Linux page size (normally 4k). If this is not the case,
3675 then the end address of the Linux memory will be located at a
3676 non page size aligned address and this could cause major
3677 problems.
3678
3679 - CONFIG_SYS_LOADS_BAUD_CHANGE:
3680 Enable temporary baudrate change while serial download
3681
3682 - CONFIG_SYS_SDRAM_BASE:
3683 Physical start address of SDRAM. _Must_ be 0 here.
3684
3685 - CONFIG_SYS_FLASH_BASE:
3686 Physical start address of Flash memory.
3687
3688 - CONFIG_SYS_MONITOR_BASE:
3689 Physical start address of boot monitor code (set by
3690 make config files to be same as the text base address
3691 (CONFIG_SYS_TEXT_BASE) used when linking) - same as
3692 CONFIG_SYS_FLASH_BASE when booting from flash.
3693
3694 - CONFIG_SYS_MONITOR_LEN:
3695 Size of memory reserved for monitor code, used to
3696 determine _at_compile_time_ (!) if the environment is
3697 embedded within the U-Boot image, or in a separate
3698 flash sector.
3699
3700 - CONFIG_SYS_MALLOC_LEN:
3701 Size of DRAM reserved for malloc() use.
3702
3703 - CONFIG_SYS_MALLOC_F_LEN
3704 Size of the malloc() pool for use before relocation. If
3705 this is defined, then a very simple malloc() implementation
3706 will become available before relocation. The address is just
3707 below the global data, and the stack is moved down to make
3708 space.
3709
3710 This feature allocates regions with increasing addresses
3711 within the region. calloc() is supported, but realloc()
3712 is not available. free() is supported but does nothing.
3713 The memory will be freed (or in fact just forgotten) when
3714 U-Boot relocates itself.
3715
3716 - CONFIG_SYS_MALLOC_SIMPLE
3717 Provides a simple and small malloc() and calloc() for those
3718 boards which do not use the full malloc in SPL (which is
3719 enabled with CONFIG_SYS_SPL_MALLOC_START).
3720
3721 - CONFIG_SYS_NONCACHED_MEMORY:
3722 Size of non-cached memory area. This area of memory will be
3723 typically located right below the malloc() area and mapped
3724 uncached in the MMU. This is useful for drivers that would
3725 otherwise require a lot of explicit cache maintenance. For
3726 some drivers it's also impossible to properly maintain the
3727 cache. For example if the regions that need to be flushed
3728 are not a multiple of the cache-line size, *and* padding
3729 cannot be allocated between the regions to align them (i.e.
3730 if the HW requires a contiguous array of regions, and the
3731 size of each region is not cache-aligned), then a flush of
3732 one region may result in overwriting data that hardware has
3733 written to another region in the same cache-line. This can
3734 happen for example in network drivers where descriptors for
3735 buffers are typically smaller than the CPU cache-line (e.g.
3736 16 bytes vs. 32 or 64 bytes).
3737
3738 Non-cached memory is only supported on 32-bit ARM at present.
3739
3740 - CONFIG_SYS_BOOTM_LEN:
3741 Normally compressed uImages are limited to an
3742 uncompressed size of 8 MBytes. If this is not enough,
3743 you can define CONFIG_SYS_BOOTM_LEN in your board config file
3744 to adjust this setting to your needs.
3745
3746 - CONFIG_SYS_BOOTMAPSZ:
3747 Maximum size of memory mapped by the startup code of
3748 the Linux kernel; all data that must be processed by
3749 the Linux kernel (bd_info, boot arguments, FDT blob if
3750 used) must be put below this limit, unless "bootm_low"
3751 environment variable is defined and non-zero. In such case
3752 all data for the Linux kernel must be between "bootm_low"
3753 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ. The environment
3754 variable "bootm_mapsize" will override the value of
3755 CONFIG_SYS_BOOTMAPSZ. If CONFIG_SYS_BOOTMAPSZ is undefined,
3756 then the value in "bootm_size" will be used instead.
3757
3758 - CONFIG_SYS_BOOT_RAMDISK_HIGH:
3759 Enable initrd_high functionality. If defined then the
3760 initrd_high feature is enabled and the bootm ramdisk subcommand
3761 is enabled.
3762
3763 - CONFIG_SYS_BOOT_GET_CMDLINE:
3764 Enables allocating and saving kernel cmdline in space between
3765 "bootm_low" and "bootm_low" + BOOTMAPSZ.
3766
3767 - CONFIG_SYS_BOOT_GET_KBD:
3768 Enables allocating and saving a kernel copy of the bd_info in
3769 space between "bootm_low" and "bootm_low" + BOOTMAPSZ.
3770
3771 - CONFIG_SYS_MAX_FLASH_BANKS:
3772 Max number of Flash memory banks
3773
3774 - CONFIG_SYS_MAX_FLASH_SECT:
3775 Max number of sectors on a Flash chip
3776
3777 - CONFIG_SYS_FLASH_ERASE_TOUT:
3778 Timeout for Flash erase operations (in ms)
3779
3780 - CONFIG_SYS_FLASH_WRITE_TOUT:
3781 Timeout for Flash write operations (in ms)
3782
3783 - CONFIG_SYS_FLASH_LOCK_TOUT
3784 Timeout for Flash set sector lock bit operation (in ms)
3785
3786 - CONFIG_SYS_FLASH_UNLOCK_TOUT
3787 Timeout for Flash clear lock bits operation (in ms)
3788
3789 - CONFIG_SYS_FLASH_PROTECTION
3790 If defined, hardware flash sectors protection is used
3791 instead of U-Boot software protection.
3792
3793 - CONFIG_SYS_DIRECT_FLASH_TFTP:
3794
3795 Enable TFTP transfers directly to flash memory;
3796 without this option such a download has to be
3797 performed in two steps: (1) download to RAM, and (2)
3798 copy from RAM to flash.
3799
3800 The two-step approach is usually more reliable, since
3801 you can check if the download worked before you erase
3802 the flash, but in some situations (when system RAM is
3803 too limited to allow for a temporary copy of the
3804 downloaded image) this option may be very useful.
3805
3806 - CONFIG_SYS_FLASH_CFI:
3807 Define if the flash driver uses extra elements in the
3808 common flash structure for storing flash geometry.
3809
3810 - CONFIG_FLASH_CFI_DRIVER
3811 This option also enables the building of the cfi_flash driver
3812 in the drivers directory
3813
3814 - CONFIG_FLASH_CFI_MTD
3815 This option enables the building of the cfi_mtd driver
3816 in the drivers directory. The driver exports CFI flash
3817 to the MTD layer.
3818
3819 - CONFIG_SYS_FLASH_USE_BUFFER_WRITE
3820 Use buffered writes to flash.
3821
3822 - CONFIG_FLASH_SPANSION_S29WS_N
3823 s29ws-n MirrorBit flash has non-standard addresses for buffered
3824 write commands.
3825
3826 - CONFIG_SYS_FLASH_QUIET_TEST
3827 If this option is defined, the common CFI flash doesn't
3828 print it's warning upon not recognized FLASH banks. This
3829 is useful, if some of the configured banks are only
3830 optionally available.
3831
3832 - CONFIG_FLASH_SHOW_PROGRESS
3833 If defined (must be an integer), print out countdown
3834 digits and dots. Recommended value: 45 (9..1) for 80
3835 column displays, 15 (3..1) for 40 column displays.
3836
3837 - CONFIG_FLASH_VERIFY
3838 If defined, the content of the flash (destination) is compared
3839 against the source after the write operation. An error message
3840 will be printed when the contents are not identical.
3841 Please note that this option is useless in nearly all cases,
3842 since such flash programming errors usually are detected earlier
3843 while unprotecting/erasing/programming. Please only enable
3844 this option if you really know what you are doing.
3845
3846 - CONFIG_SYS_RX_ETH_BUFFER:
3847 Defines the number of Ethernet receive buffers. On some
3848 Ethernet controllers it is recommended to set this value
3849 to 8 or even higher (EEPRO100 or 405 EMAC), since all
3850 buffers can be full shortly after enabling the interface
3851 on high Ethernet traffic.
3852 Defaults to 4 if not defined.
3853
3854 - CONFIG_ENV_MAX_ENTRIES
3855
3856 Maximum number of entries in the hash table that is used
3857 internally to store the environment settings. The default
3858 setting is supposed to be generous and should work in most
3859 cases. This setting can be used to tune behaviour; see
3860 lib/hashtable.c for details.
3861
3862 - CONFIG_ENV_FLAGS_LIST_DEFAULT
3863 - CONFIG_ENV_FLAGS_LIST_STATIC
3864 Enable validation of the values given to environment variables when
3865 calling env set. Variables can be restricted to only decimal,
3866 hexadecimal, or boolean. If CONFIG_CMD_NET is also defined,
3867 the variables can also be restricted to IP address or MAC address.
3868
3869 The format of the list is:
3870 type_attribute = [s|d|x|b|i|m]
3871 access_attribute = [a|r|o|c]
3872 attributes = type_attribute[access_attribute]
3873 entry = variable_name[:attributes]
3874 list = entry[,list]
3875
3876 The type attributes are:
3877 s - String (default)
3878 d - Decimal
3879 x - Hexadecimal
3880 b - Boolean ([1yYtT|0nNfF])
3881 i - IP address
3882 m - MAC address
3883
3884 The access attributes are:
3885 a - Any (default)
3886 r - Read-only
3887 o - Write-once
3888 c - Change-default
3889
3890 - CONFIG_ENV_FLAGS_LIST_DEFAULT
3891 Define this to a list (string) to define the ".flags"
3892 environment variable in the default or embedded environment.
3893
3894 - CONFIG_ENV_FLAGS_LIST_STATIC
3895 Define this to a list (string) to define validation that
3896 should be done if an entry is not found in the ".flags"
3897 environment variable. To override a setting in the static
3898 list, simply add an entry for the same variable name to the
3899 ".flags" variable.
3900
3901 If CONFIG_REGEX is defined, the variable_name above is evaluated as a
3902 regular expression. This allows multiple variables to define the same
3903 flags without explicitly listing them for each variable.
3904
3905 - CONFIG_ENV_ACCESS_IGNORE_FORCE
3906 If defined, don't allow the -f switch to env set override variable
3907 access flags.
3908
3909 - CONFIG_OMAP_PLATFORM_RESET_TIME_MAX_USEC (OMAP only)
3910 This is set by OMAP boards for the max time that reset should
3911 be asserted. See doc/README.omap-reset-time for details on how
3912 the value can be calculated on a given board.
3913
3914 - CONFIG_USE_STDINT
3915 If stdint.h is available with your toolchain you can define this
3916 option to enable it. You can provide option 'USE_STDINT=1' when
3917 building U-Boot to enable this.
3918
3919 The following definitions that deal with the placement and management
3920 of environment data (variable area); in general, we support the
3921 following configurations:
3922
3923 - CONFIG_BUILD_ENVCRC:
3924
3925 Builds up envcrc with the target environment so that external utils
3926 may easily extract it and embed it in final U-Boot images.
3927
3928 - CONFIG_ENV_IS_IN_FLASH:
3929
3930 Define this if the environment is in flash memory.
3931
3932 a) The environment occupies one whole flash sector, which is
3933 "embedded" in the text segment with the U-Boot code. This
3934 happens usually with "bottom boot sector" or "top boot
3935 sector" type flash chips, which have several smaller
3936 sectors at the start or the end. For instance, such a
3937 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In
3938 such a case you would place the environment in one of the
3939 4 kB sectors - with U-Boot code before and after it. With
3940 "top boot sector" type flash chips, you would put the
3941 environment in one of the last sectors, leaving a gap
3942 between U-Boot and the environment.
3943
3944 - CONFIG_ENV_OFFSET:
3945
3946 Offset of environment data (variable area) to the
3947 beginning of flash memory; for instance, with bottom boot
3948 type flash chips the second sector can be used: the offset
3949 for this sector is given here.
3950
3951 CONFIG_ENV_OFFSET is used relative to CONFIG_SYS_FLASH_BASE.
3952
3953 - CONFIG_ENV_ADDR:
3954
3955 This is just another way to specify the start address of
3956 the flash sector containing the environment (instead of
3957 CONFIG_ENV_OFFSET).
3958
3959 - CONFIG_ENV_SECT_SIZE:
3960
3961 Size of the sector containing the environment.
3962
3963
3964 b) Sometimes flash chips have few, equal sized, BIG sectors.
3965 In such a case you don't want to spend a whole sector for
3966 the environment.
3967
3968 - CONFIG_ENV_SIZE:
3969
3970 If you use this in combination with CONFIG_ENV_IS_IN_FLASH
3971 and CONFIG_ENV_SECT_SIZE, you can specify to use only a part
3972 of this flash sector for the environment. This saves
3973 memory for the RAM copy of the environment.
3974
3975 It may also save flash memory if you decide to use this
3976 when your environment is "embedded" within U-Boot code,
3977 since then the remainder of the flash sector could be used
3978 for U-Boot code. It should be pointed out that this is
3979 STRONGLY DISCOURAGED from a robustness point of view:
3980 updating the environment in flash makes it always
3981 necessary to erase the WHOLE sector. If something goes
3982 wrong before the contents has been restored from a copy in
3983 RAM, your target system will be dead.
3984
3985 - CONFIG_ENV_ADDR_REDUND
3986 CONFIG_ENV_SIZE_REDUND
3987
3988 These settings describe a second storage area used to hold
3989 a redundant copy of the environment data, so that there is
3990 a valid backup copy in case there is a power failure during
3991 a "saveenv" operation.
3992
3993 BE CAREFUL! Any changes to the flash layout, and some changes to the
3994 source code will make it necessary to adapt <board>/u-boot.lds*
3995 accordingly!
3996
3997
3998 - CONFIG_ENV_IS_IN_NVRAM:
3999
4000 Define this if you have some non-volatile memory device
4001 (NVRAM, battery buffered SRAM) which you want to use for the
4002 environment.
4003
4004 - CONFIG_ENV_ADDR:
4005 - CONFIG_ENV_SIZE:
4006
4007 These two #defines are used to determine the memory area you
4008 want to use for environment. It is assumed that this memory
4009 can just be read and written to, without any special
4010 provision.
4011
4012 BE CAREFUL! The first access to the environment happens quite early
4013 in U-Boot initialization (when we try to get the setting of for the
4014 console baudrate). You *MUST* have mapped your NVRAM area then, or
4015 U-Boot will hang.
4016
4017 Please note that even with NVRAM we still use a copy of the
4018 environment in RAM: we could work on NVRAM directly, but we want to
4019 keep settings there always unmodified except somebody uses "saveenv"
4020 to save the current settings.
4021
4022
4023 - CONFIG_ENV_IS_IN_EEPROM:
4024
4025 Use this if you have an EEPROM or similar serial access
4026 device and a driver for it.
4027
4028 - CONFIG_ENV_OFFSET:
4029 - CONFIG_ENV_SIZE:
4030
4031 These two #defines specify the offset and size of the
4032 environment area within the total memory of your EEPROM.
4033
4034 - CONFIG_SYS_I2C_EEPROM_ADDR:
4035 If defined, specified the chip address of the EEPROM device.
4036 The default address is zero.
4037
4038 - CONFIG_SYS_I2C_EEPROM_BUS:
4039 If defined, specified the i2c bus of the EEPROM device.
4040
4041 - CONFIG_SYS_EEPROM_PAGE_WRITE_BITS:
4042 If defined, the number of bits used to address bytes in a
4043 single page in the EEPROM device. A 64 byte page, for example
4044 would require six bits.
4045
4046 - CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS:
4047 If defined, the number of milliseconds to delay between
4048 page writes. The default is zero milliseconds.
4049
4050 - CONFIG_SYS_I2C_EEPROM_ADDR_LEN:
4051 The length in bytes of the EEPROM memory array address. Note
4052 that this is NOT the chip address length!
4053
4054 - CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW:
4055 EEPROM chips that implement "address overflow" are ones
4056 like Catalyst 24WC04/08/16 which has 9/10/11 bits of
4057 address and the extra bits end up in the "chip address" bit
4058 slots. This makes a 24WC08 (1Kbyte) chip look like four 256
4059 byte chips.
4060
4061 Note that we consider the length of the address field to
4062 still be one byte because the extra address bits are hidden
4063 in the chip address.
4064
4065 - CONFIG_SYS_EEPROM_SIZE:
4066 The size in bytes of the EEPROM device.
4067
4068 - CONFIG_ENV_EEPROM_IS_ON_I2C
4069 define this, if you have I2C and SPI activated, and your
4070 EEPROM, which holds the environment, is on the I2C bus.
4071
4072 - CONFIG_I2C_ENV_EEPROM_BUS
4073 if you have an Environment on an EEPROM reached over
4074 I2C muxes, you can define here, how to reach this
4075 EEPROM. For example:
4076
4077 #define CONFIG_I2C_ENV_EEPROM_BUS 1
4078
4079 EEPROM which holds the environment, is reached over
4080 a pca9547 i2c mux with address 0x70, channel 3.
4081
4082 - CONFIG_ENV_IS_IN_DATAFLASH:
4083
4084 Define this if you have a DataFlash memory device which you
4085 want to use for the environment.
4086
4087 - CONFIG_ENV_OFFSET:
4088 - CONFIG_ENV_ADDR:
4089 - CONFIG_ENV_SIZE:
4090
4091 These three #defines specify the offset and size of the
4092 environment area within the total memory of your DataFlash placed
4093 at the specified address.
4094
4095 - CONFIG_ENV_IS_IN_SPI_FLASH:
4096
4097 Define this if you have a SPI Flash memory device which you
4098 want to use for the environment.
4099
4100 - CONFIG_ENV_OFFSET:
4101 - CONFIG_ENV_SIZE:
4102
4103 These two #defines specify the offset and size of the
4104 environment area within the SPI Flash. CONFIG_ENV_OFFSET must be
4105 aligned to an erase sector boundary.
4106
4107 - CONFIG_ENV_SECT_SIZE:
4108
4109 Define the SPI flash's sector size.
4110
4111 - CONFIG_ENV_OFFSET_REDUND (optional):
4112
4113 This setting describes a second storage area of CONFIG_ENV_SIZE
4114 size used to hold a redundant copy of the environment data, so
4115 that there is a valid backup copy in case there is a power failure
4116 during a "saveenv" operation. CONFIG_ENV_OFFSET_REDUND must be
4117 aligned to an erase sector boundary.
4118
4119 - CONFIG_ENV_SPI_BUS (optional):
4120 - CONFIG_ENV_SPI_CS (optional):
4121
4122 Define the SPI bus and chip select. If not defined they will be 0.
4123
4124 - CONFIG_ENV_SPI_MAX_HZ (optional):
4125
4126 Define the SPI max work clock. If not defined then use 1MHz.
4127
4128 - CONFIG_ENV_SPI_MODE (optional):
4129
4130 Define the SPI work mode. If not defined then use SPI_MODE_3.
4131
4132 - CONFIG_ENV_IS_IN_REMOTE:
4133
4134 Define this if you have a remote memory space which you
4135 want to use for the local device's environment.
4136
4137 - CONFIG_ENV_ADDR:
4138 - CONFIG_ENV_SIZE:
4139
4140 These two #defines specify the address and size of the
4141 environment area within the remote memory space. The
4142 local device can get the environment from remote memory
4143 space by SRIO or PCIE links.
4144
4145 BE CAREFUL! For some special cases, the local device can not use
4146 "saveenv" command. For example, the local device will get the
4147 environment stored in a remote NOR flash by SRIO or PCIE link,
4148 but it can not erase, write this NOR flash by SRIO or PCIE interface.
4149
4150 - CONFIG_ENV_IS_IN_NAND:
4151
4152 Define this if you have a NAND device which you want to use
4153 for the environment.
4154
4155 - CONFIG_ENV_OFFSET:
4156 - CONFIG_ENV_SIZE:
4157
4158 These two #defines specify the offset and size of the environment
4159 area within the first NAND device. CONFIG_ENV_OFFSET must be
4160 aligned to an erase block boundary.
4161
4162 - CONFIG_ENV_OFFSET_REDUND (optional):
4163
4164 This setting describes a second storage area of CONFIG_ENV_SIZE
4165 size used to hold a redundant copy of the environment data, so
4166 that there is a valid backup copy in case there is a power failure
4167 during a "saveenv" operation. CONFIG_ENV_OFFSET_REDUND must be
4168 aligned to an erase block boundary.
4169
4170 - CONFIG_ENV_RANGE (optional):
4171
4172 Specifies the length of the region in which the environment
4173 can be written. This should be a multiple of the NAND device's
4174 block size. Specifying a range with more erase blocks than
4175 are needed to hold CONFIG_ENV_SIZE allows bad blocks within
4176 the range to be avoided.
4177
4178 - CONFIG_ENV_OFFSET_OOB (optional):
4179
4180 Enables support for dynamically retrieving the offset of the
4181 environment from block zero's out-of-band data. The
4182 "nand env.oob" command can be used to record this offset.
4183 Currently, CONFIG_ENV_OFFSET_REDUND is not supported when
4184 using CONFIG_ENV_OFFSET_OOB.
4185
4186 - CONFIG_NAND_ENV_DST
4187
4188 Defines address in RAM to which the nand_spl code should copy the
4189 environment. If redundant environment is used, it will be copied to
4190 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE.
4191
4192 - CONFIG_ENV_IS_IN_UBI:
4193
4194 Define this if you have an UBI volume that you want to use for the
4195 environment. This has the benefit of wear-leveling the environment
4196 accesses, which is important on NAND.
4197
4198 - CONFIG_ENV_UBI_PART:
4199
4200 Define this to a string that is the mtd partition containing the UBI.
4201
4202 - CONFIG_ENV_UBI_VOLUME:
4203
4204 Define this to the name of the volume that you want to store the
4205 environment in.
4206
4207 - CONFIG_ENV_UBI_VOLUME_REDUND:
4208
4209 Define this to the name of another volume to store a second copy of
4210 the environment in. This will enable redundant environments in UBI.
4211 It is assumed that both volumes are in the same MTD partition.
4212
4213 - CONFIG_UBI_SILENCE_MSG
4214 - CONFIG_UBIFS_SILENCE_MSG
4215
4216 You will probably want to define these to avoid a really noisy system
4217 when storing the env in UBI.
4218
4219 - CONFIG_ENV_IS_IN_FAT:
4220 Define this if you want to use the FAT file system for the environment.
4221
4222 - FAT_ENV_INTERFACE:
4223
4224 Define this to a string that is the name of the block device.
4225
4226 - FAT_ENV_DEV_AND_PART:
4227
4228 Define this to a string to specify the partition of the device. It can
4229 be as following:
4230
4231 "D:P", "D:0", "D", "D:" or "D:auto" (D, P are integers. And P >= 1)
4232 - "D:P": device D partition P. Error occurs if device D has no
4233 partition table.
4234 - "D:0": device D.
4235 - "D" or "D:": device D partition 1 if device D has partition
4236 table, or the whole device D if has no partition
4237 table.
4238 - "D:auto": first partition in device D with bootable flag set.
4239 If none, first valid partition in device D. If no
4240 partition table then means device D.
4241
4242 - FAT_ENV_FILE:
4243
4244 It's a string of the FAT file name. This file use to store the
4245 environment.
4246
4247 - CONFIG_FAT_WRITE:
4248 This should be defined. Otherwise it cannot save the environment file.
4249
4250 - CONFIG_ENV_IS_IN_MMC:
4251
4252 Define this if you have an MMC device which you want to use for the
4253 environment.
4254
4255 - CONFIG_SYS_MMC_ENV_DEV:
4256
4257 Specifies which MMC device the environment is stored in.
4258
4259 - CONFIG_SYS_MMC_ENV_PART (optional):
4260
4261 Specifies which MMC partition the environment is stored in. If not
4262 set, defaults to partition 0, the user area. Common values might be
4263 1 (first MMC boot partition), 2 (second MMC boot partition).
4264
4265 - CONFIG_ENV_OFFSET:
4266 - CONFIG_ENV_SIZE:
4267
4268 These two #defines specify the offset and size of the environment
4269 area within the specified MMC device.
4270
4271 If offset is positive (the usual case), it is treated as relative to
4272 the start of the MMC partition. If offset is negative, it is treated
4273 as relative to the end of the MMC partition. This can be useful if
4274 your board may be fitted with different MMC devices, which have
4275 different sizes for the MMC partitions, and you always want the
4276 environment placed at the very end of the partition, to leave the
4277 maximum possible space before it, to store other data.
4278
4279 These two values are in units of bytes, but must be aligned to an
4280 MMC sector boundary.
4281
4282 - CONFIG_ENV_OFFSET_REDUND (optional):
4283
4284 Specifies a second storage area, of CONFIG_ENV_SIZE size, used to
4285 hold a redundant copy of the environment data. This provides a
4286 valid backup copy in case the other copy is corrupted, e.g. due
4287 to a power failure during a "saveenv" operation.
4288
4289 This value may also be positive or negative; this is handled in the
4290 same way as CONFIG_ENV_OFFSET.
4291
4292 This value is also in units of bytes, but must also be aligned to
4293 an MMC sector boundary.
4294
4295 - CONFIG_ENV_SIZE_REDUND (optional):
4296
4297 This value need not be set, even when CONFIG_ENV_OFFSET_REDUND is
4298 set. If this value is set, it must be set to the same value as
4299 CONFIG_ENV_SIZE.
4300
4301 - CONFIG_SYS_SPI_INIT_OFFSET
4302
4303 Defines offset to the initial SPI buffer area in DPRAM. The
4304 area is used at an early stage (ROM part) if the environment
4305 is configured to reside in the SPI EEPROM: We need a 520 byte
4306 scratch DPRAM area. It is used between the two initialization
4307 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems
4308 to be a good choice since it makes it far enough from the
4309 start of the data area as well as from the stack pointer.
4310
4311 Please note that the environment is read-only until the monitor
4312 has been relocated to RAM and a RAM copy of the environment has been
4313 created; also, when using EEPROM you will have to use getenv_f()
4314 until then to read environment variables.
4315
4316 The environment is protected by a CRC32 checksum. Before the monitor
4317 is relocated into RAM, as a result of a bad CRC you will be working
4318 with the compiled-in default environment - *silently*!!! [This is
4319 necessary, because the first environment variable we need is the
4320 "baudrate" setting for the console - if we have a bad CRC, we don't
4321 have any device yet where we could complain.]
4322
4323 Note: once the monitor has been relocated, then it will complain if
4324 the default environment is used; a new CRC is computed as soon as you
4325 use the "saveenv" command to store a valid environment.
4326
4327 - CONFIG_SYS_FAULT_ECHO_LINK_DOWN:
4328 Echo the inverted Ethernet link state to the fault LED.
4329
4330 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR
4331 also needs to be defined.
4332
4333 - CONFIG_SYS_FAULT_MII_ADDR:
4334 MII address of the PHY to check for the Ethernet link state.
4335
4336 - CONFIG_NS16550_MIN_FUNCTIONS:
4337 Define this if you desire to only have use of the NS16550_init
4338 and NS16550_putc functions for the serial driver located at
4339 drivers/serial/ns16550.c. This option is useful for saving
4340 space for already greatly restricted images, including but not
4341 limited to NAND_SPL configurations.
4342
4343 - CONFIG_DISPLAY_BOARDINFO
4344 Display information about the board that U-Boot is running on
4345 when U-Boot starts up. The board function checkboard() is called
4346 to do this.
4347
4348 - CONFIG_DISPLAY_BOARDINFO_LATE
4349 Similar to the previous option, but display this information
4350 later, once stdio is running and output goes to the LCD, if
4351 present.
4352
4353 - CONFIG_BOARD_SIZE_LIMIT:
4354 Maximum size of the U-Boot image. When defined, the
4355 build system checks that the actual size does not
4356 exceed it.
4357
4358 Low Level (hardware related) configuration options:
4359 ---------------------------------------------------
4360
4361 - CONFIG_SYS_CACHELINE_SIZE:
4362 Cache Line Size of the CPU.
4363
4364 - CONFIG_SYS_DEFAULT_IMMR:
4365 Default address of the IMMR after system reset.
4366
4367 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU,
4368 and RPXsuper) to be able to adjust the position of
4369 the IMMR register after a reset.
4370
4371 - CONFIG_SYS_CCSRBAR_DEFAULT:
4372 Default (power-on reset) physical address of CCSR on Freescale
4373 PowerPC SOCs.
4374
4375 - CONFIG_SYS_CCSRBAR:
4376 Virtual address of CCSR. On a 32-bit build, this is typically
4377 the same value as CONFIG_SYS_CCSRBAR_DEFAULT.
4378
4379 CONFIG_SYS_DEFAULT_IMMR must also be set to this value,
4380 for cross-platform code that uses that macro instead.
4381
4382 - CONFIG_SYS_CCSRBAR_PHYS:
4383 Physical address of CCSR. CCSR can be relocated to a new
4384 physical address, if desired. In this case, this macro should
4385 be set to that address. Otherwise, it should be set to the
4386 same value as CONFIG_SYS_CCSRBAR_DEFAULT. For example, CCSR
4387 is typically relocated on 36-bit builds. It is recommended
4388 that this macro be defined via the _HIGH and _LOW macros:
4389
4390 #define CONFIG_SYS_CCSRBAR_PHYS ((CONFIG_SYS_CCSRBAR_PHYS_HIGH
4391 * 1ull) << 32 | CONFIG_SYS_CCSRBAR_PHYS_LOW)
4392
4393 - CONFIG_SYS_CCSRBAR_PHYS_HIGH:
4394 Bits 33-36 of CONFIG_SYS_CCSRBAR_PHYS. This value is typically
4395 either 0 (32-bit build) or 0xF (36-bit build). This macro is
4396 used in assembly code, so it must not contain typecasts or
4397 integer size suffixes (e.g. "ULL").
4398
4399 - CONFIG_SYS_CCSRBAR_PHYS_LOW:
4400 Lower 32-bits of CONFIG_SYS_CCSRBAR_PHYS. This macro is
4401 used in assembly code, so it must not contain typecasts or
4402 integer size suffixes (e.g. "ULL").
4403
4404 - CONFIG_SYS_CCSR_DO_NOT_RELOCATE:
4405 If this macro is defined, then CONFIG_SYS_CCSRBAR_PHYS will be
4406 forced to a value that ensures that CCSR is not relocated.
4407
4408 - Floppy Disk Support:
4409 CONFIG_SYS_FDC_DRIVE_NUMBER
4410
4411 the default drive number (default value 0)
4412
4413 CONFIG_SYS_ISA_IO_STRIDE
4414
4415 defines the spacing between FDC chipset registers
4416 (default value 1)
4417
4418 CONFIG_SYS_ISA_IO_OFFSET
4419
4420 defines the offset of register from address. It
4421 depends on which part of the data bus is connected to
4422 the FDC chipset. (default value 0)
4423
4424 If CONFIG_SYS_ISA_IO_STRIDE CONFIG_SYS_ISA_IO_OFFSET and
4425 CONFIG_SYS_FDC_DRIVE_NUMBER are undefined, they take their
4426 default value.
4427
4428 if CONFIG_SYS_FDC_HW_INIT is defined, then the function
4429 fdc_hw_init() is called at the beginning of the FDC
4430 setup. fdc_hw_init() must be provided by the board
4431 source code. It is used to make hardware-dependent
4432 initializations.
4433
4434 - CONFIG_IDE_AHB:
4435 Most IDE controllers were designed to be connected with PCI
4436 interface. Only few of them were designed for AHB interface.
4437 When software is doing ATA command and data transfer to
4438 IDE devices through IDE-AHB controller, some additional
4439 registers accessing to these kind of IDE-AHB controller
4440 is required.
4441
4442 - CONFIG_SYS_IMMR: Physical address of the Internal Memory.
4443 DO NOT CHANGE unless you know exactly what you're
4444 doing! (11-4) [MPC8xx/82xx systems only]
4445
4446 - CONFIG_SYS_INIT_RAM_ADDR:
4447
4448 Start address of memory area that can be used for
4449 initial data and stack; please note that this must be
4450 writable memory that is working WITHOUT special
4451 initialization, i. e. you CANNOT use normal RAM which
4452 will become available only after programming the
4453 memory controller and running certain initialization
4454 sequences.
4455
4456 U-Boot uses the following memory types:
4457 - MPC8xx and MPC8260: IMMR (internal memory of the CPU)
4458 - MPC824X: data cache
4459 - PPC4xx: data cache
4460
4461 - CONFIG_SYS_GBL_DATA_OFFSET:
4462
4463 Offset of the initial data structure in the memory
4464 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually
4465 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial
4466 data is located at the end of the available space
4467 (sometimes written as (CONFIG_SYS_INIT_RAM_SIZE -
4468 GENERATED_GBL_DATA_SIZE), and the initial stack is just
4469 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR +
4470 CONFIG_SYS_GBL_DATA_OFFSET) downward.
4471
4472 Note:
4473 On the MPC824X (or other systems that use the data
4474 cache for initial memory) the address chosen for
4475 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must
4476 point to an otherwise UNUSED address space between
4477 the top of RAM and the start of the PCI space.
4478
4479 - CONFIG_SYS_SIUMCR: SIU Module Configuration (11-6)
4480
4481 - CONFIG_SYS_SYPCR: System Protection Control (11-9)
4482
4483 - CONFIG_SYS_TBSCR: Time Base Status and Control (11-26)
4484
4485 - CONFIG_SYS_PISCR: Periodic Interrupt Status and Control (11-31)
4486
4487 - CONFIG_SYS_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30)
4488
4489 - CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27)
4490
4491 - CONFIG_SYS_OR_TIMING_SDRAM:
4492 SDRAM timing
4493
4494 - CONFIG_SYS_MAMR_PTA:
4495 periodic timer for refresh
4496
4497 - CONFIG_SYS_DER: Debug Event Register (37-47)
4498
4499 - FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM,
4500 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP,
4501 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM,
4502 CONFIG_SYS_BR1_PRELIM:
4503 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
4504
4505 - SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
4506 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM,
4507 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM:
4508 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
4509
4510 - CONFIG_SYS_MAMR_PTA, CONFIG_SYS_MPTPR_2BK_4K, CONFIG_SYS_MPTPR_1BK_4K, CONFIG_SYS_MPTPR_2BK_8K,
4511 CONFIG_SYS_MPTPR_1BK_8K, CONFIG_SYS_MAMR_8COL, CONFIG_SYS_MAMR_9COL:
4512 Machine Mode Register and Memory Periodic Timer
4513 Prescaler definitions (SDRAM timing)
4514
4515 - CONFIG_SYS_I2C_UCODE_PATCH, CONFIG_SYS_I2C_DPMEM_OFFSET [0x1FC0]:
4516 enable I2C microcode relocation patch (MPC8xx);
4517 define relocation offset in DPRAM [DSP2]
4518
4519 - CONFIG_SYS_SMC_UCODE_PATCH, CONFIG_SYS_SMC_DPMEM_OFFSET [0x1FC0]:
4520 enable SMC microcode relocation patch (MPC8xx);
4521 define relocation offset in DPRAM [SMC1]
4522
4523 - CONFIG_SYS_SPI_UCODE_PATCH, CONFIG_SYS_SPI_DPMEM_OFFSET [0x1FC0]:
4524 enable SPI microcode relocation patch (MPC8xx);
4525 define relocation offset in DPRAM [SCC4]
4526
4527 - CONFIG_SYS_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only)
4528 Offset of the bootmode word in DPRAM used by post
4529 (Power On Self Tests). This definition overrides
4530 #define'd default value in commproc.h resp.
4531 cpm_8260.h.
4532
4533 - CONFIG_SYS_PCI_SLV_MEM_LOCAL, CONFIG_SYS_PCI_SLV_MEM_BUS, CONFIG_SYS_PICMR0_MASK_ATTRIB,
4534 CONFIG_SYS_PCI_MSTR0_LOCAL, CONFIG_SYS_PCIMSK0_MASK, CONFIG_SYS_PCI_MSTR1_LOCAL,
4535 CONFIG_SYS_PCIMSK1_MASK, CONFIG_SYS_PCI_MSTR_MEM_LOCAL, CONFIG_SYS_PCI_MSTR_MEM_BUS,
4536 CONFIG_SYS_CPU_PCI_MEM_START, CONFIG_SYS_PCI_MSTR_MEM_SIZE, CONFIG_SYS_POCMR0_MASK_ATTRIB,
4537 CONFIG_SYS_PCI_MSTR_MEMIO_LOCAL, CONFIG_SYS_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START,
4538 CONFIG_SYS_PCI_MSTR_MEMIO_SIZE, CONFIG_SYS_POCMR1_MASK_ATTRIB, CONFIG_SYS_PCI_MSTR_IO_LOCAL,
4539 CONFIG_SYS_PCI_MSTR_IO_BUS, CONFIG_SYS_CPU_PCI_IO_START, CONFIG_SYS_PCI_MSTR_IO_SIZE,
4540 CONFIG_SYS_POCMR2_MASK_ATTRIB: (MPC826x only)
4541 Overrides the default PCI memory map in arch/powerpc/cpu/mpc8260/pci.c if set.
4542
4543 - CONFIG_PCI_DISABLE_PCIE:
4544 Disable PCI-Express on systems where it is supported but not
4545 required.
4546
4547 - CONFIG_PCI_ENUM_ONLY
4548 Only scan through and get the devices on the buses.
4549 Don't do any setup work, presumably because someone or
4550 something has already done it, and we don't need to do it
4551 a second time. Useful for platforms that are pre-booted
4552 by coreboot or similar.
4553
4554 - CONFIG_PCI_INDIRECT_BRIDGE:
4555 Enable support for indirect PCI bridges.
4556
4557 - CONFIG_SYS_SRIO:
4558 Chip has SRIO or not
4559
4560 - CONFIG_SRIO1:
4561 Board has SRIO 1 port available
4562
4563 - CONFIG_SRIO2:
4564 Board has SRIO 2 port available
4565
4566 - CONFIG_SRIO_PCIE_BOOT_MASTER
4567 Board can support master function for Boot from SRIO and PCIE
4568
4569 - CONFIG_SYS_SRIOn_MEM_VIRT:
4570 Virtual Address of SRIO port 'n' memory region
4571
4572 - CONFIG_SYS_SRIOn_MEM_PHYS:
4573 Physical Address of SRIO port 'n' memory region
4574
4575 - CONFIG_SYS_SRIOn_MEM_SIZE:
4576 Size of SRIO port 'n' memory region
4577
4578 - CONFIG_SYS_NAND_BUSWIDTH_16BIT
4579 Defined to tell the NAND controller that the NAND chip is using
4580 a 16 bit bus.
4581 Not all NAND drivers use this symbol.
4582 Example of drivers that use it:
4583 - drivers/mtd/nand/ndfc.c
4584 - drivers/mtd/nand/mxc_nand.c
4585
4586 - CONFIG_SYS_NDFC_EBC0_CFG
4587 Sets the EBC0_CFG register for the NDFC. If not defined
4588 a default value will be used.
4589
4590 - CONFIG_SPD_EEPROM
4591 Get DDR timing information from an I2C EEPROM. Common
4592 with pluggable memory modules such as SODIMMs
4593
4594 SPD_EEPROM_ADDRESS
4595 I2C address of the SPD EEPROM
4596
4597 - CONFIG_SYS_SPD_BUS_NUM
4598 If SPD EEPROM is on an I2C bus other than the first
4599 one, specify here. Note that the value must resolve
4600 to something your driver can deal with.
4601
4602 - CONFIG_SYS_DDR_RAW_TIMING
4603 Get DDR timing information from other than SPD. Common with
4604 soldered DDR chips onboard without SPD. DDR raw timing
4605 parameters are extracted from datasheet and hard-coded into
4606 header files or board specific files.
4607
4608 - CONFIG_FSL_DDR_INTERACTIVE
4609 Enable interactive DDR debugging. See doc/README.fsl-ddr.
4610
4611 - CONFIG_FSL_DDR_SYNC_REFRESH
4612 Enable sync of refresh for multiple controllers.
4613
4614 - CONFIG_FSL_DDR_BIST
4615 Enable built-in memory test for Freescale DDR controllers.
4616
4617 - CONFIG_SYS_83XX_DDR_USES_CS0
4618 Only for 83xx systems. If specified, then DDR should
4619 be configured using CS0 and CS1 instead of CS2 and CS3.
4620
4621 - CONFIG_ETHER_ON_FEC[12]
4622 Define to enable FEC[12] on a 8xx series processor.
4623
4624 - CONFIG_FEC[12]_PHY
4625 Define to the hardcoded PHY address which corresponds
4626 to the given FEC; i. e.
4627 #define CONFIG_FEC1_PHY 4
4628 means that the PHY with address 4 is connected to FEC1
4629
4630 When set to -1, means to probe for first available.
4631
4632 - CONFIG_FEC[12]_PHY_NORXERR
4633 The PHY does not have a RXERR line (RMII only).
4634 (so program the FEC to ignore it).
4635
4636 - CONFIG_RMII
4637 Enable RMII mode for all FECs.
4638 Note that this is a global option, we can't
4639 have one FEC in standard MII mode and another in RMII mode.
4640
4641 - CONFIG_CRC32_VERIFY
4642 Add a verify option to the crc32 command.
4643 The syntax is:
4644
4645 => crc32 -v <address> <count> <crc32>
4646
4647 Where address/count indicate a memory area
4648 and crc32 is the correct crc32 which the
4649 area should have.
4650
4651 - CONFIG_LOOPW
4652 Add the "loopw" memory command. This only takes effect if
4653 the memory commands are activated globally (CONFIG_CMD_MEM).
4654
4655 - CONFIG_MX_CYCLIC
4656 Add the "mdc" and "mwc" memory commands. These are cyclic
4657 "md/mw" commands.
4658 Examples:
4659
4660 => mdc.b 10 4 500
4661 This command will print 4 bytes (10,11,12,13) each 500 ms.
4662
4663 => mwc.l 100 12345678 10
4664 This command will write 12345678 to address 100 all 10 ms.
4665
4666 This only takes effect if the memory commands are activated
4667 globally (CONFIG_CMD_MEM).
4668
4669 - CONFIG_SKIP_LOWLEVEL_INIT
4670 [ARM, NDS32, MIPS only] If this variable is defined, then certain
4671 low level initializations (like setting up the memory
4672 controller) are omitted and/or U-Boot does not
4673 relocate itself into RAM.
4674
4675 Normally this variable MUST NOT be defined. The only
4676 exception is when U-Boot is loaded (to RAM) by some
4677 other boot loader or by a debugger which performs
4678 these initializations itself.
4679
4680 - CONFIG_SKIP_LOWLEVEL_INIT_ONLY
4681 [ARM926EJ-S only] This allows just the call to lowlevel_init()
4682 to be skipped. The normal CP15 init (such as enabling the
4683 instruction cache) is still performed.
4684
4685 - CONFIG_SPL_BUILD
4686 Modifies the behaviour of start.S when compiling a loader
4687 that is executed before the actual U-Boot. E.g. when
4688 compiling a NAND SPL.
4689
4690 - CONFIG_TPL_BUILD
4691 Modifies the behaviour of start.S when compiling a loader
4692 that is executed after the SPL and before the actual U-Boot.
4693 It is loaded by the SPL.
4694
4695 - CONFIG_SYS_MPC85XX_NO_RESETVEC
4696 Only for 85xx systems. If this variable is specified, the section
4697 .resetvec is not kept and the section .bootpg is placed in the
4698 previous 4k of the .text section.
4699
4700 - CONFIG_ARCH_MAP_SYSMEM
4701 Generally U-Boot (and in particular the md command) uses
4702 effective address. It is therefore not necessary to regard
4703 U-Boot address as virtual addresses that need to be translated
4704 to physical addresses. However, sandbox requires this, since
4705 it maintains its own little RAM buffer which contains all
4706 addressable memory. This option causes some memory accesses
4707 to be mapped through map_sysmem() / unmap_sysmem().
4708
4709 - CONFIG_USE_ARCH_MEMCPY
4710 CONFIG_USE_ARCH_MEMSET
4711 If these options are used a optimized version of memcpy/memset will
4712 be used if available. These functions may be faster under some
4713 conditions but may increase the binary size.
4714
4715 - CONFIG_X86_RESET_VECTOR
4716 If defined, the x86 reset vector code is included. This is not
4717 needed when U-Boot is running from Coreboot.
4718
4719 - CONFIG_SYS_MPUCLK
4720 Defines the MPU clock speed (in MHz).
4721
4722 NOTE : currently only supported on AM335x platforms.
4723
4724 - CONFIG_SPL_AM33XX_ENABLE_RTC32K_OSC:
4725 Enables the RTC32K OSC on AM33xx based plattforms
4726
4727 - CONFIG_SYS_NAND_NO_SUBPAGE_WRITE
4728 Option to disable subpage write in NAND driver
4729 driver that uses this:
4730 drivers/mtd/nand/davinci_nand.c
4731
4732 Freescale QE/FMAN Firmware Support:
4733 -----------------------------------
4734
4735 The Freescale QUICCEngine (QE) and Frame Manager (FMAN) both support the
4736 loading of "firmware", which is encoded in the QE firmware binary format.
4737 This firmware often needs to be loaded during U-Boot booting, so macros
4738 are used to identify the storage device (NOR flash, SPI, etc) and the address
4739 within that device.
4740
4741 - CONFIG_SYS_FMAN_FW_ADDR
4742 The address in the storage device where the FMAN microcode is located. The
4743 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
4744 is also specified.
4745
4746 - CONFIG_SYS_QE_FW_ADDR
4747 The address in the storage device where the QE microcode is located. The
4748 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
4749 is also specified.
4750
4751 - CONFIG_SYS_QE_FMAN_FW_LENGTH
4752 The maximum possible size of the firmware. The firmware binary format
4753 has a field that specifies the actual size of the firmware, but it
4754 might not be possible to read any part of the firmware unless some
4755 local storage is allocated to hold the entire firmware first.
4756
4757 - CONFIG_SYS_QE_FMAN_FW_IN_NOR
4758 Specifies that QE/FMAN firmware is located in NOR flash, mapped as
4759 normal addressable memory via the LBC. CONFIG_SYS_FMAN_FW_ADDR is the
4760 virtual address in NOR flash.
4761
4762 - CONFIG_SYS_QE_FMAN_FW_IN_NAND
4763 Specifies that QE/FMAN firmware is located in NAND flash.
4764 CONFIG_SYS_FMAN_FW_ADDR is the offset within NAND flash.
4765
4766 - CONFIG_SYS_QE_FMAN_FW_IN_MMC
4767 Specifies that QE/FMAN firmware is located on the primary SD/MMC
4768 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
4769
4770 - CONFIG_SYS_QE_FMAN_FW_IN_REMOTE
4771 Specifies that QE/FMAN firmware is located in the remote (master)
4772 memory space. CONFIG_SYS_FMAN_FW_ADDR is a virtual address which
4773 can be mapped from slave TLB->slave LAW->slave SRIO or PCIE outbound
4774 window->master inbound window->master LAW->the ucode address in
4775 master's memory space.
4776
4777 Freescale Layerscape Management Complex Firmware Support:
4778 ---------------------------------------------------------
4779 The Freescale Layerscape Management Complex (MC) supports the loading of
4780 "firmware".
4781 This firmware often needs to be loaded during U-Boot booting, so macros
4782 are used to identify the storage device (NOR flash, SPI, etc) and the address
4783 within that device.
4784
4785 - CONFIG_FSL_MC_ENET
4786 Enable the MC driver for Layerscape SoCs.
4787
4788 Freescale Layerscape Debug Server Support:
4789 -------------------------------------------
4790 The Freescale Layerscape Debug Server Support supports the loading of
4791 "Debug Server firmware" and triggering SP boot-rom.
4792 This firmware often needs to be loaded during U-Boot booting.
4793
4794 - CONFIG_SYS_MC_RSV_MEM_ALIGN
4795 Define alignment of reserved memory MC requires
4796
4797 Reproducible builds
4798 -------------------
4799
4800 In order to achieve reproducible builds, timestamps used in the U-Boot build
4801 process have to be set to a fixed value.
4802
4803 This is done using the SOURCE_DATE_EPOCH environment variable.
4804 SOURCE_DATE_EPOCH is to be set on the build host's shell, not as a configuration
4805 option for U-Boot or an environment variable in U-Boot.
4806
4807 SOURCE_DATE_EPOCH should be set to a number of seconds since the epoch, in UTC.
4808
4809 Building the Software:
4810 ======================
4811
4812 Building U-Boot has been tested in several native build environments
4813 and in many different cross environments. Of course we cannot support
4814 all possibly existing versions of cross development tools in all
4815 (potentially obsolete) versions. In case of tool chain problems we
4816 recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK)
4817 which is extensively used to build and test U-Boot.
4818
4819 If you are not using a native environment, it is assumed that you
4820 have GNU cross compiling tools available in your path. In this case,
4821 you must set the environment variable CROSS_COMPILE in your shell.
4822 Note that no changes to the Makefile or any other source files are
4823 necessary. For example using the ELDK on a 4xx CPU, please enter:
4824
4825 $ CROSS_COMPILE=ppc_4xx-
4826 $ export CROSS_COMPILE
4827
4828 Note: If you wish to generate Windows versions of the utilities in
4829 the tools directory you can use the MinGW toolchain
4830 (http://www.mingw.org). Set your HOST tools to the MinGW
4831 toolchain and execute 'make tools'. For example:
4832
4833 $ make HOSTCC=i586-mingw32msvc-gcc HOSTSTRIP=i586-mingw32msvc-strip tools
4834
4835 Binaries such as tools/mkimage.exe will be created which can
4836 be executed on computers running Windows.
4837
4838 U-Boot is intended to be simple to build. After installing the
4839 sources you must configure U-Boot for one specific board type. This
4840 is done by typing:
4841
4842 make NAME_defconfig
4843
4844 where "NAME_defconfig" is the name of one of the existing configu-
4845 rations; see boards.cfg for supported names.
4846
4847 Note: for some board special configuration names may exist; check if
4848 additional information is available from the board vendor; for
4849 instance, the TQM823L systems are available without (standard)
4850 or with LCD support. You can select such additional "features"
4851 when choosing the configuration, i. e.
4852
4853 make TQM823L_defconfig
4854 - will configure for a plain TQM823L, i. e. no LCD support
4855
4856 make TQM823L_LCD_defconfig
4857 - will configure for a TQM823L with U-Boot console on LCD
4858
4859 etc.
4860
4861
4862 Finally, type "make all", and you should get some working U-Boot
4863 images ready for download to / installation on your system:
4864
4865 - "u-boot.bin" is a raw binary image
4866 - "u-boot" is an image in ELF binary format
4867 - "u-boot.srec" is in Motorola S-Record format
4868
4869 By default the build is performed locally and the objects are saved
4870 in the source directory. One of the two methods can be used to change
4871 this behavior and build U-Boot to some external directory:
4872
4873 1. Add O= to the make command line invocations:
4874
4875 make O=/tmp/build distclean
4876 make O=/tmp/build NAME_defconfig
4877 make O=/tmp/build all
4878
4879 2. Set environment variable KBUILD_OUTPUT to point to the desired location:
4880
4881 export KBUILD_OUTPUT=/tmp/build
4882 make distclean
4883 make NAME_defconfig
4884 make all
4885
4886 Note that the command line "O=" setting overrides the KBUILD_OUTPUT environment
4887 variable.
4888
4889
4890 Please be aware that the Makefiles assume you are using GNU make, so
4891 for instance on NetBSD you might need to use "gmake" instead of
4892 native "make".
4893
4894
4895 If the system board that you have is not listed, then you will need
4896 to port U-Boot to your hardware platform. To do this, follow these
4897 steps:
4898
4899 1. Create a new directory to hold your board specific code. Add any
4900 files you need. In your board directory, you will need at least
4901 the "Makefile" and a "<board>.c".
4902 2. Create a new configuration file "include/configs/<board>.h" for
4903 your board.
4904 3. If you're porting U-Boot to a new CPU, then also create a new
4905 directory to hold your CPU specific code. Add any files you need.
4906 4. Run "make <board>_defconfig" with your new name.
4907 5. Type "make", and you should get a working "u-boot.srec" file
4908 to be installed on your target system.
4909 6. Debug and solve any problems that might arise.
4910 [Of course, this last step is much harder than it sounds.]
4911
4912
4913 Testing of U-Boot Modifications, Ports to New Hardware, etc.:
4914 ==============================================================
4915
4916 If you have modified U-Boot sources (for instance added a new board
4917 or support for new devices, a new CPU, etc.) you are expected to
4918 provide feedback to the other developers. The feedback normally takes
4919 the form of a "patch", i. e. a context diff against a certain (latest
4920 official or latest in the git repository) version of U-Boot sources.
4921
4922 But before you submit such a patch, please verify that your modifi-
4923 cation did not break existing code. At least make sure that *ALL* of
4924 the supported boards compile WITHOUT ANY compiler warnings. To do so,
4925 just run the buildman script (tools/buildman/buildman), which will
4926 configure and build U-Boot for ALL supported system. Be warned, this
4927 will take a while. Please see the buildman README, or run 'buildman -H'
4928 for documentation.
4929
4930
4931 See also "U-Boot Porting Guide" below.
4932
4933
4934 Monitor Commands - Overview:
4935 ============================
4936
4937 go - start application at address 'addr'
4938 run - run commands in an environment variable
4939 bootm - boot application image from memory
4940 bootp - boot image via network using BootP/TFTP protocol
4941 bootz - boot zImage from memory
4942 tftpboot- boot image via network using TFTP protocol
4943 and env variables "ipaddr" and "serverip"
4944 (and eventually "gatewayip")
4945 tftpput - upload a file via network using TFTP protocol
4946 rarpboot- boot image via network using RARP/TFTP protocol
4947 diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
4948 loads - load S-Record file over serial line
4949 loadb - load binary file over serial line (kermit mode)
4950 md - memory display
4951 mm - memory modify (auto-incrementing)
4952 nm - memory modify (constant address)
4953 mw - memory write (fill)
4954 cp - memory copy
4955 cmp - memory compare
4956 crc32 - checksum calculation
4957 i2c - I2C sub-system
4958 sspi - SPI utility commands
4959 base - print or set address offset
4960 printenv- print environment variables
4961 setenv - set environment variables
4962 saveenv - save environment variables to persistent storage
4963 protect - enable or disable FLASH write protection
4964 erase - erase FLASH memory
4965 flinfo - print FLASH memory information
4966 nand - NAND memory operations (see doc/README.nand)
4967 bdinfo - print Board Info structure
4968 iminfo - print header information for application image
4969 coninfo - print console devices and informations
4970 ide - IDE sub-system
4971 loop - infinite loop on address range
4972 loopw - infinite write loop on address range
4973 mtest - simple RAM test
4974 icache - enable or disable instruction cache
4975 dcache - enable or disable data cache
4976 reset - Perform RESET of the CPU
4977 echo - echo args to console
4978 version - print monitor version
4979 help - print online help
4980 ? - alias for 'help'
4981
4982
4983 Monitor Commands - Detailed Description:
4984 ========================================
4985
4986 TODO.
4987
4988 For now: just type "help <command>".
4989
4990
4991 Environment Variables:
4992 ======================
4993
4994 U-Boot supports user configuration using Environment Variables which
4995 can be made persistent by saving to Flash memory.
4996
4997 Environment Variables are set using "setenv", printed using
4998 "printenv", and saved to Flash using "saveenv". Using "setenv"
4999 without a value can be used to delete a variable from the
5000 environment. As long as you don't save the environment you are
5001 working with an in-memory copy. In case the Flash area containing the
5002 environment is erased by accident, a default environment is provided.
5003
5004 Some configuration options can be set using Environment Variables.
5005
5006 List of environment variables (most likely not complete):
5007
5008 baudrate - see CONFIG_BAUDRATE
5009
5010 bootdelay - see CONFIG_BOOTDELAY
5011
5012 bootcmd - see CONFIG_BOOTCOMMAND
5013
5014 bootargs - Boot arguments when booting an RTOS image
5015
5016 bootfile - Name of the image to load with TFTP
5017
5018 bootm_low - Memory range available for image processing in the bootm
5019 command can be restricted. This variable is given as
5020 a hexadecimal number and defines lowest address allowed
5021 for use by the bootm command. See also "bootm_size"
5022 environment variable. Address defined by "bootm_low" is
5023 also the base of the initial memory mapping for the Linux
5024 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ and
5025 bootm_mapsize.
5026
5027 bootm_mapsize - Size of the initial memory mapping for the Linux kernel.
5028 This variable is given as a hexadecimal number and it
5029 defines the size of the memory region starting at base
5030 address bootm_low that is accessible by the Linux kernel
5031 during early boot. If unset, CONFIG_SYS_BOOTMAPSZ is used
5032 as the default value if it is defined, and bootm_size is
5033 used otherwise.
5034
5035 bootm_size - Memory range available for image processing in the bootm
5036 command can be restricted. This variable is given as
5037 a hexadecimal number and defines the size of the region
5038 allowed for use by the bootm command. See also "bootm_low"
5039 environment variable.
5040
5041 updatefile - Location of the software update file on a TFTP server, used
5042 by the automatic software update feature. Please refer to
5043 documentation in doc/README.update for more details.
5044
5045 autoload - if set to "no" (any string beginning with 'n'),
5046 "bootp" will just load perform a lookup of the
5047 configuration from the BOOTP server, but not try to
5048 load any image using TFTP
5049
5050 autostart - if set to "yes", an image loaded using the "bootp",
5051 "rarpboot", "tftpboot" or "diskboot" commands will
5052 be automatically started (by internally calling
5053 "bootm")
5054
5055 If set to "no", a standalone image passed to the
5056 "bootm" command will be copied to the load address
5057 (and eventually uncompressed), but NOT be started.
5058 This can be used to load and uncompress arbitrary
5059 data.
5060
5061 fdt_high - if set this restricts the maximum address that the
5062 flattened device tree will be copied into upon boot.
5063 For example, if you have a system with 1 GB memory
5064 at physical address 0x10000000, while Linux kernel
5065 only recognizes the first 704 MB as low memory, you
5066 may need to set fdt_high as 0x3C000000 to have the
5067 device tree blob be copied to the maximum address
5068 of the 704 MB low memory, so that Linux kernel can
5069 access it during the boot procedure.
5070
5071 If this is set to the special value 0xFFFFFFFF then
5072 the fdt will not be copied at all on boot. For this
5073 to work it must reside in writable memory, have
5074 sufficient padding on the end of it for u-boot to
5075 add the information it needs into it, and the memory
5076 must be accessible by the kernel.
5077
5078 fdtcontroladdr- if set this is the address of the control flattened
5079 device tree used by U-Boot when CONFIG_OF_CONTROL is
5080 defined.
5081
5082 i2cfast - (PPC405GP|PPC405EP only)
5083 if set to 'y' configures Linux I2C driver for fast
5084 mode (400kHZ). This environment variable is used in
5085 initialization code. So, for changes to be effective
5086 it must be saved and board must be reset.
5087
5088 initrd_high - restrict positioning of initrd images:
5089 If this variable is not set, initrd images will be
5090 copied to the highest possible address in RAM; this
5091 is usually what you want since it allows for
5092 maximum initrd size. If for some reason you want to
5093 make sure that the initrd image is loaded below the
5094 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment
5095 variable to a value of "no" or "off" or "0".
5096 Alternatively, you can set it to a maximum upper
5097 address to use (U-Boot will still check that it
5098 does not overwrite the U-Boot stack and data).
5099
5100 For instance, when you have a system with 16 MB
5101 RAM, and want to reserve 4 MB from use by Linux,
5102 you can do this by adding "mem=12M" to the value of
5103 the "bootargs" variable. However, now you must make
5104 sure that the initrd image is placed in the first
5105 12 MB as well - this can be done with
5106
5107 setenv initrd_high 00c00000
5108
5109 If you set initrd_high to 0xFFFFFFFF, this is an
5110 indication to U-Boot that all addresses are legal
5111 for the Linux kernel, including addresses in flash
5112 memory. In this case U-Boot will NOT COPY the
5113 ramdisk at all. This may be useful to reduce the
5114 boot time on your system, but requires that this
5115 feature is supported by your Linux kernel.
5116
5117 ipaddr - IP address; needed for tftpboot command
5118
5119 loadaddr - Default load address for commands like "bootp",
5120 "rarpboot", "tftpboot", "loadb" or "diskboot"
5121
5122 loads_echo - see CONFIG_LOADS_ECHO
5123
5124 serverip - TFTP server IP address; needed for tftpboot command
5125
5126 bootretry - see CONFIG_BOOT_RETRY_TIME
5127
5128 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
5129
5130 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
5131
5132 ethprime - controls which interface is used first.
5133
5134 ethact - controls which interface is currently active.
5135 For example you can do the following
5136
5137 => setenv ethact FEC
5138 => ping 192.168.0.1 # traffic sent on FEC
5139 => setenv ethact SCC
5140 => ping 10.0.0.1 # traffic sent on SCC
5141
5142 ethrotate - When set to "no" U-Boot does not go through all
5143 available network interfaces.
5144 It just stays at the currently selected interface.
5145
5146 netretry - When set to "no" each network operation will
5147 either succeed or fail without retrying.
5148 When set to "once" the network operation will
5149 fail when all the available network interfaces
5150 are tried once without success.
5151 Useful on scripts which control the retry operation
5152 themselves.
5153
5154 npe_ucode - set load address for the NPE microcode
5155
5156 silent_linux - If set then Linux will be told to boot silently, by
5157 changing the console to be empty. If "yes" it will be
5158 made silent. If "no" it will not be made silent. If
5159 unset, then it will be made silent if the U-Boot console
5160 is silent.
5161
5162 tftpsrcp - If this is set, the value is used for TFTP's
5163 UDP source port.
5164
5165 tftpdstp - If this is set, the value is used for TFTP's UDP
5166 destination port instead of the Well Know Port 69.
5167
5168 tftpblocksize - Block size to use for TFTP transfers; if not set,
5169 we use the TFTP server's default block size
5170
5171 tftptimeout - Retransmission timeout for TFTP packets (in milli-
5172 seconds, minimum value is 1000 = 1 second). Defines
5173 when a packet is considered to be lost so it has to
5174 be retransmitted. The default is 5000 = 5 seconds.
5175 Lowering this value may make downloads succeed
5176 faster in networks with high packet loss rates or
5177 with unreliable TFTP servers.
5178
5179 tftptimeoutcountmax - maximum count of TFTP timeouts (no
5180 unit, minimum value = 0). Defines how many timeouts
5181 can happen during a single file transfer before that
5182 transfer is aborted. The default is 10, and 0 means
5183 'no timeouts allowed'. Increasing this value may help
5184 downloads succeed with high packet loss rates, or with
5185 unreliable TFTP servers or client hardware.
5186
5187 vlan - When set to a value < 4095 the traffic over
5188 Ethernet is encapsulated/received over 802.1q
5189 VLAN tagged frames.
5190
5191 bootpretryperiod - Period during which BOOTP/DHCP sends retries.
5192 Unsigned value, in milliseconds. If not set, the period will
5193 be either the default (28000), or a value based on
5194 CONFIG_NET_RETRY_COUNT, if defined. This value has
5195 precedence over the valu based on CONFIG_NET_RETRY_COUNT.
5196
5197 The following image location variables contain the location of images
5198 used in booting. The "Image" column gives the role of the image and is
5199 not an environment variable name. The other columns are environment
5200 variable names. "File Name" gives the name of the file on a TFTP
5201 server, "RAM Address" gives the location in RAM the image will be
5202 loaded to, and "Flash Location" gives the image's address in NOR
5203 flash or offset in NAND flash.
5204
5205 *Note* - these variables don't have to be defined for all boards, some
5206 boards currently use other variables for these purposes, and some
5207 boards use these variables for other purposes.
5208
5209 Image File Name RAM Address Flash Location
5210 ----- --------- ----------- --------------
5211 u-boot u-boot u-boot_addr_r u-boot_addr
5212 Linux kernel bootfile kernel_addr_r kernel_addr
5213 device tree blob fdtfile fdt_addr_r fdt_addr
5214 ramdisk ramdiskfile ramdisk_addr_r ramdisk_addr
5215
5216 The following environment variables may be used and automatically
5217 updated by the network boot commands ("bootp" and "rarpboot"),
5218 depending the information provided by your boot server:
5219
5220 bootfile - see above
5221 dnsip - IP address of your Domain Name Server
5222 dnsip2 - IP address of your secondary Domain Name Server
5223 gatewayip - IP address of the Gateway (Router) to use
5224 hostname - Target hostname
5225 ipaddr - see above
5226 netmask - Subnet Mask
5227 rootpath - Pathname of the root filesystem on the NFS server
5228 serverip - see above
5229
5230
5231 There are two special Environment Variables:
5232
5233 serial# - contains hardware identification information such
5234 as type string and/or serial number
5235 ethaddr - Ethernet address
5236
5237 These variables can be set only once (usually during manufacturing of
5238 the board). U-Boot refuses to delete or overwrite these variables
5239 once they have been set once.
5240
5241
5242 Further special Environment Variables:
5243
5244 ver - Contains the U-Boot version string as printed
5245 with the "version" command. This variable is
5246 readonly (see CONFIG_VERSION_VARIABLE).
5247
5248
5249 Please note that changes to some configuration parameters may take
5250 only effect after the next boot (yes, that's just like Windoze :-).
5251
5252
5253 Callback functions for environment variables:
5254 ---------------------------------------------
5255
5256 For some environment variables, the behavior of u-boot needs to change
5257 when their values are changed. This functionality allows functions to
5258 be associated with arbitrary variables. On creation, overwrite, or
5259 deletion, the callback will provide the opportunity for some side
5260 effect to happen or for the change to be rejected.
5261
5262 The callbacks are named and associated with a function using the
5263 U_BOOT_ENV_CALLBACK macro in your board or driver code.
5264
5265 These callbacks are associated with variables in one of two ways. The
5266 static list can be added to by defining CONFIG_ENV_CALLBACK_LIST_STATIC
5267 in the board configuration to a string that defines a list of
5268 associations. The list must be in the following format:
5269
5270 entry = variable_name[:callback_name]
5271 list = entry[,list]
5272
5273 If the callback name is not specified, then the callback is deleted.
5274 Spaces are also allowed anywhere in the list.
5275
5276 Callbacks can also be associated by defining the ".callbacks" variable
5277 with the same list format above. Any association in ".callbacks" will
5278 override any association in the static list. You can define
5279 CONFIG_ENV_CALLBACK_LIST_DEFAULT to a list (string) to define the
5280 ".callbacks" environment variable in the default or embedded environment.
5281
5282 If CONFIG_REGEX is defined, the variable_name above is evaluated as a
5283 regular expression. This allows multiple variables to be connected to
5284 the same callback without explicitly listing them all out.
5285
5286
5287 Command Line Parsing:
5288 =====================
5289
5290 There are two different command line parsers available with U-Boot:
5291 the old "simple" one, and the much more powerful "hush" shell:
5292
5293 Old, simple command line parser:
5294 --------------------------------
5295
5296 - supports environment variables (through setenv / saveenv commands)
5297 - several commands on one line, separated by ';'
5298 - variable substitution using "... ${name} ..." syntax
5299 - special characters ('$', ';') can be escaped by prefixing with '\',
5300 for example:
5301 setenv bootcmd bootm \${address}
5302 - You can also escape text by enclosing in single apostrophes, for example:
5303 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
5304
5305 Hush shell:
5306 -----------
5307
5308 - similar to Bourne shell, with control structures like
5309 if...then...else...fi, for...do...done; while...do...done,
5310 until...do...done, ...
5311 - supports environment ("global") variables (through setenv / saveenv
5312 commands) and local shell variables (through standard shell syntax
5313 "name=value"); only environment variables can be used with "run"
5314 command
5315
5316 General rules:
5317 --------------
5318
5319 (1) If a command line (or an environment variable executed by a "run"
5320 command) contains several commands separated by semicolon, and
5321 one of these commands fails, then the remaining commands will be
5322 executed anyway.
5323
5324 (2) If you execute several variables with one call to run (i. e.
5325 calling run with a list of variables as arguments), any failing
5326 command will cause "run" to terminate, i. e. the remaining
5327 variables are not executed.
5328
5329 Note for Redundant Ethernet Interfaces:
5330 =======================================
5331
5332 Some boards come with redundant Ethernet interfaces; U-Boot supports
5333 such configurations and is capable of automatic selection of a
5334 "working" interface when needed. MAC assignment works as follows:
5335
5336 Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
5337 MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
5338 "eth1addr" (=>eth1), "eth2addr", ...
5339
5340 If the network interface stores some valid MAC address (for instance
5341 in SROM), this is used as default address if there is NO correspon-
5342 ding setting in the environment; if the corresponding environment
5343 variable is set, this overrides the settings in the card; that means:
5344
5345 o If the SROM has a valid MAC address, and there is no address in the
5346 environment, the SROM's address is used.
5347
5348 o If there is no valid address in the SROM, and a definition in the
5349 environment exists, then the value from the environment variable is
5350 used.
5351
5352 o If both the SROM and the environment contain a MAC address, and
5353 both addresses are the same, this MAC address is used.
5354
5355 o If both the SROM and the environment contain a MAC address, and the
5356 addresses differ, the value from the environment is used and a
5357 warning is printed.
5358
5359 o If neither SROM nor the environment contain a MAC address, an error
5360 is raised. If CONFIG_NET_RANDOM_ETHADDR is defined, then in this case
5361 a random, locally-assigned MAC is used.
5362
5363 If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses
5364 will be programmed into hardware as part of the initialization process. This
5365 may be skipped by setting the appropriate 'ethmacskip' environment variable.
5366 The naming convention is as follows:
5367 "ethmacskip" (=>eth0), "eth1macskip" (=>eth1) etc.
5368
5369 Image Formats:
5370 ==============
5371
5372 U-Boot is capable of booting (and performing other auxiliary operations on)
5373 images in two formats:
5374
5375 New uImage format (FIT)
5376 -----------------------
5377
5378 Flexible and powerful format based on Flattened Image Tree -- FIT (similar
5379 to Flattened Device Tree). It allows the use of images with multiple
5380 components (several kernels, ramdisks, etc.), with contents protected by
5381 SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory.
5382
5383
5384 Old uImage format
5385 -----------------
5386
5387 Old image format is based on binary files which can be basically anything,
5388 preceded by a special header; see the definitions in include/image.h for
5389 details; basically, the header defines the following image properties:
5390
5391 * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
5392 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
5393 LynxOS, pSOS, QNX, RTEMS, INTEGRITY;
5394 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS,
5395 INTEGRITY).
5396 * Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86,
5397 IA64, MIPS, NDS32, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
5398 Currently supported: ARM, AVR32, Intel x86, MIPS, NDS32, Nios II, PowerPC).
5399 * Compression Type (uncompressed, gzip, bzip2)
5400 * Load Address
5401 * Entry Point
5402 * Image Name
5403 * Image Timestamp
5404
5405 The header is marked by a special Magic Number, and both the header
5406 and the data portions of the image are secured against corruption by
5407 CRC32 checksums.
5408
5409
5410 Linux Support:
5411 ==============
5412
5413 Although U-Boot should support any OS or standalone application
5414 easily, the main focus has always been on Linux during the design of
5415 U-Boot.
5416
5417 U-Boot includes many features that so far have been part of some
5418 special "boot loader" code within the Linux kernel. Also, any
5419 "initrd" images to be used are no longer part of one big Linux image;
5420 instead, kernel and "initrd" are separate images. This implementation
5421 serves several purposes:
5422
5423 - the same features can be used for other OS or standalone
5424 applications (for instance: using compressed images to reduce the
5425 Flash memory footprint)
5426
5427 - it becomes much easier to port new Linux kernel versions because
5428 lots of low-level, hardware dependent stuff are done by U-Boot
5429
5430 - the same Linux kernel image can now be used with different "initrd"
5431 images; of course this also means that different kernel images can
5432 be run with the same "initrd". This makes testing easier (you don't
5433 have to build a new "zImage.initrd" Linux image when you just
5434 change a file in your "initrd"). Also, a field-upgrade of the
5435 software is easier now.
5436
5437
5438 Linux HOWTO:
5439 ============
5440
5441 Porting Linux to U-Boot based systems:
5442 ---------------------------------------
5443
5444 U-Boot cannot save you from doing all the necessary modifications to
5445 configure the Linux device drivers for use with your target hardware
5446 (no, we don't intend to provide a full virtual machine interface to
5447 Linux :-).
5448
5449 But now you can ignore ALL boot loader code (in arch/powerpc/mbxboot).
5450
5451 Just make sure your machine specific header file (for instance
5452 include/asm-ppc/tqm8xx.h) includes the same definition of the Board
5453 Information structure as we define in include/asm-<arch>/u-boot.h,
5454 and make sure that your definition of IMAP_ADDR uses the same value
5455 as your U-Boot configuration in CONFIG_SYS_IMMR.
5456
5457 Note that U-Boot now has a driver model, a unified model for drivers.
5458 If you are adding a new driver, plumb it into driver model. If there
5459 is no uclass available, you are encouraged to create one. See
5460 doc/driver-model.
5461
5462
5463 Configuring the Linux kernel:
5464 -----------------------------
5465
5466 No specific requirements for U-Boot. Make sure you have some root
5467 device (initial ramdisk, NFS) for your target system.
5468
5469
5470 Building a Linux Image:
5471 -----------------------
5472
5473 With U-Boot, "normal" build targets like "zImage" or "bzImage" are
5474 not used. If you use recent kernel source, a new build target
5475 "uImage" will exist which automatically builds an image usable by
5476 U-Boot. Most older kernels also have support for a "pImage" target,
5477 which was introduced for our predecessor project PPCBoot and uses a
5478 100% compatible format.
5479
5480 Example:
5481
5482 make TQM850L_defconfig
5483 make oldconfig
5484 make dep
5485 make uImage
5486
5487 The "uImage" build target uses a special tool (in 'tools/mkimage') to
5488 encapsulate a compressed Linux kernel image with header information,
5489 CRC32 checksum etc. for use with U-Boot. This is what we are doing:
5490
5491 * build a standard "vmlinux" kernel image (in ELF binary format):
5492
5493 * convert the kernel into a raw binary image:
5494
5495 ${CROSS_COMPILE}-objcopy -O binary \
5496 -R .note -R .comment \
5497 -S vmlinux linux.bin
5498
5499 * compress the binary image:
5500
5501 gzip -9 linux.bin
5502
5503 * package compressed binary image for U-Boot:
5504
5505 mkimage -A ppc -O linux -T kernel -C gzip \
5506 -a 0 -e 0 -n "Linux Kernel Image" \
5507 -d linux.bin.gz uImage
5508
5509
5510 The "mkimage" tool can also be used to create ramdisk images for use
5511 with U-Boot, either separated from the Linux kernel image, or
5512 combined into one file. "mkimage" encapsulates the images with a 64
5513 byte header containing information about target architecture,
5514 operating system, image type, compression method, entry points, time
5515 stamp, CRC32 checksums, etc.
5516
5517 "mkimage" can be called in two ways: to verify existing images and
5518 print the header information, or to build new images.
5519
5520 In the first form (with "-l" option) mkimage lists the information
5521 contained in the header of an existing U-Boot image; this includes
5522 checksum verification:
5523
5524 tools/mkimage -l image
5525 -l ==> list image header information
5526
5527 The second form (with "-d" option) is used to build a U-Boot image
5528 from a "data file" which is used as image payload:
5529
5530 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
5531 -n name -d data_file image
5532 -A ==> set architecture to 'arch'
5533 -O ==> set operating system to 'os'
5534 -T ==> set image type to 'type'
5535 -C ==> set compression type 'comp'
5536 -a ==> set load address to 'addr' (hex)
5537 -e ==> set entry point to 'ep' (hex)
5538 -n ==> set image name to 'name'
5539 -d ==> use image data from 'datafile'
5540
5541 Right now, all Linux kernels for PowerPC systems use the same load
5542 address (0x00000000), but the entry point address depends on the
5543 kernel version:
5544
5545 - 2.2.x kernels have the entry point at 0x0000000C,
5546 - 2.3.x and later kernels have the entry point at 0x00000000.
5547
5548 So a typical call to build a U-Boot image would read:
5549
5550 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
5551 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
5552 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz \
5553 > examples/uImage.TQM850L
5554 Image Name: 2.4.4 kernel for TQM850L
5555 Created: Wed Jul 19 02:34:59 2000
5556 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5557 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
5558 Load Address: 0x00000000
5559 Entry Point: 0x00000000
5560
5561 To verify the contents of the image (or check for corruption):
5562
5563 -> tools/mkimage -l examples/uImage.TQM850L
5564 Image Name: 2.4.4 kernel for TQM850L
5565 Created: Wed Jul 19 02:34:59 2000
5566 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5567 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
5568 Load Address: 0x00000000
5569 Entry Point: 0x00000000
5570
5571 NOTE: for embedded systems where boot time is critical you can trade
5572 speed for memory and install an UNCOMPRESSED image instead: this
5573 needs more space in Flash, but boots much faster since it does not
5574 need to be uncompressed:
5575
5576 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz
5577 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
5578 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
5579 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux \
5580 > examples/uImage.TQM850L-uncompressed
5581 Image Name: 2.4.4 kernel for TQM850L
5582 Created: Wed Jul 19 02:34:59 2000
5583 Image Type: PowerPC Linux Kernel Image (uncompressed)
5584 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
5585 Load Address: 0x00000000
5586 Entry Point: 0x00000000
5587
5588
5589 Similar you can build U-Boot images from a 'ramdisk.image.gz' file
5590 when your kernel is intended to use an initial ramdisk:
5591
5592 -> tools/mkimage -n 'Simple Ramdisk Image' \
5593 > -A ppc -O linux -T ramdisk -C gzip \
5594 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
5595 Image Name: Simple Ramdisk Image
5596 Created: Wed Jan 12 14:01:50 2000
5597 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5598 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
5599 Load Address: 0x00000000
5600 Entry Point: 0x00000000
5601
5602 The "dumpimage" is a tool to disassemble images built by mkimage. Its "-i"
5603 option performs the converse operation of the mkimage's second form (the "-d"
5604 option). Given an image built by mkimage, the dumpimage extracts a "data file"
5605 from the image:
5606
5607 tools/dumpimage -i image -T type -p position data_file
5608 -i ==> extract from the 'image' a specific 'data_file'
5609 -T ==> set image type to 'type'
5610 -p ==> 'position' (starting at 0) of the 'data_file' inside the 'image'
5611
5612
5613 Installing a Linux Image:
5614 -------------------------
5615
5616 To downloading a U-Boot image over the serial (console) interface,
5617 you must convert the image to S-Record format:
5618
5619 objcopy -I binary -O srec examples/image examples/image.srec
5620
5621 The 'objcopy' does not understand the information in the U-Boot
5622 image header, so the resulting S-Record file will be relative to
5623 address 0x00000000. To load it to a given address, you need to
5624 specify the target address as 'offset' parameter with the 'loads'
5625 command.
5626
5627 Example: install the image to address 0x40100000 (which on the
5628 TQM8xxL is in the first Flash bank):
5629
5630 => erase 40100000 401FFFFF
5631
5632 .......... done
5633 Erased 8 sectors
5634
5635 => loads 40100000
5636 ## Ready for S-Record download ...
5637 ~>examples/image.srec
5638 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
5639 ...
5640 15989 15990 15991 15992
5641 [file transfer complete]
5642 [connected]
5643 ## Start Addr = 0x00000000
5644
5645
5646 You can check the success of the download using the 'iminfo' command;
5647 this includes a checksum verification so you can be sure no data
5648 corruption happened:
5649
5650 => imi 40100000
5651
5652 ## Checking Image at 40100000 ...
5653 Image Name: 2.2.13 for initrd on TQM850L
5654 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5655 Data Size: 335725 Bytes = 327 kB = 0 MB
5656 Load Address: 00000000
5657 Entry Point: 0000000c
5658 Verifying Checksum ... OK
5659
5660
5661 Boot Linux:
5662 -----------
5663
5664 The "bootm" command is used to boot an application that is stored in
5665 memory (RAM or Flash). In case of a Linux kernel image, the contents
5666 of the "bootargs" environment variable is passed to the kernel as
5667 parameters. You can check and modify this variable using the
5668 "printenv" and "setenv" commands:
5669
5670
5671 => printenv bootargs
5672 bootargs=root=/dev/ram
5673
5674 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5675
5676 => printenv bootargs
5677 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5678
5679 => bootm 40020000
5680 ## Booting Linux kernel at 40020000 ...
5681 Image Name: 2.2.13 for NFS on TQM850L
5682 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5683 Data Size: 381681 Bytes = 372 kB = 0 MB
5684 Load Address: 00000000
5685 Entry Point: 0000000c
5686 Verifying Checksum ... OK
5687 Uncompressing Kernel Image ... OK
5688 Linux version 2.2.13 (wd@denx.local.net) (gcc version 2.95.2 19991024 (release)) #1 Wed Jul 19 02:35:17 MEST 2000
5689 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5690 time_init: decrementer frequency = 187500000/60
5691 Calibrating delay loop... 49.77 BogoMIPS
5692 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
5693 ...
5694
5695 If you want to boot a Linux kernel with initial RAM disk, you pass
5696 the memory addresses of both the kernel and the initrd image (PPBCOOT
5697 format!) to the "bootm" command:
5698
5699 => imi 40100000 40200000
5700
5701 ## Checking Image at 40100000 ...
5702 Image Name: 2.2.13 for initrd on TQM850L
5703 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5704 Data Size: 335725 Bytes = 327 kB = 0 MB
5705 Load Address: 00000000
5706 Entry Point: 0000000c
5707 Verifying Checksum ... OK
5708
5709 ## Checking Image at 40200000 ...
5710 Image Name: Simple Ramdisk Image
5711 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5712 Data Size: 566530 Bytes = 553 kB = 0 MB
5713 Load Address: 00000000
5714 Entry Point: 00000000
5715 Verifying Checksum ... OK
5716
5717 => bootm 40100000 40200000
5718 ## Booting Linux kernel at 40100000 ...
5719 Image Name: 2.2.13 for initrd on TQM850L
5720 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5721 Data Size: 335725 Bytes = 327 kB = 0 MB
5722 Load Address: 00000000
5723 Entry Point: 0000000c
5724 Verifying Checksum ... OK
5725 Uncompressing Kernel Image ... OK
5726 ## Loading RAMDisk Image at 40200000 ...
5727 Image Name: Simple Ramdisk Image
5728 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5729 Data Size: 566530 Bytes = 553 kB = 0 MB
5730 Load Address: 00000000
5731 Entry Point: 00000000
5732 Verifying Checksum ... OK
5733 Loading Ramdisk ... OK
5734 Linux version 2.2.13 (wd@denx.local.net) (gcc version 2.95.2 19991024 (release)) #1 Wed Jul 19 02:32:08 MEST 2000
5735 Boot arguments: root=/dev/ram
5736 time_init: decrementer frequency = 187500000/60
5737 Calibrating delay loop... 49.77 BogoMIPS
5738 ...
5739 RAMDISK: Compressed image found at block 0
5740 VFS: Mounted root (ext2 filesystem).
5741
5742 bash#
5743
5744 Boot Linux and pass a flat device tree:
5745 -----------
5746
5747 First, U-Boot must be compiled with the appropriate defines. See the section
5748 titled "Linux Kernel Interface" above for a more in depth explanation. The
5749 following is an example of how to start a kernel and pass an updated
5750 flat device tree:
5751
5752 => print oftaddr
5753 oftaddr=0x300000
5754 => print oft
5755 oft=oftrees/mpc8540ads.dtb
5756 => tftp $oftaddr $oft
5757 Speed: 1000, full duplex
5758 Using TSEC0 device
5759 TFTP from server 192.168.1.1; our IP address is 192.168.1.101
5760 Filename 'oftrees/mpc8540ads.dtb'.
5761 Load address: 0x300000
5762 Loading: #
5763 done
5764 Bytes transferred = 4106 (100a hex)
5765 => tftp $loadaddr $bootfile
5766 Speed: 1000, full duplex
5767 Using TSEC0 device
5768 TFTP from server 192.168.1.1; our IP address is 192.168.1.2
5769 Filename 'uImage'.
5770 Load address: 0x200000
5771 Loading:############
5772 done
5773 Bytes transferred = 1029407 (fb51f hex)
5774 => print loadaddr
5775 loadaddr=200000
5776 => print oftaddr
5777 oftaddr=0x300000
5778 => bootm $loadaddr - $oftaddr
5779 ## Booting image at 00200000 ...
5780 Image Name: Linux-2.6.17-dirty
5781 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5782 Data Size: 1029343 Bytes = 1005.2 kB
5783 Load Address: 00000000
5784 Entry Point: 00000000
5785 Verifying Checksum ... OK
5786 Uncompressing Kernel Image ... OK
5787 Booting using flat device tree at 0x300000
5788 Using MPC85xx ADS machine description
5789 Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb
5790 [snip]
5791
5792
5793 More About U-Boot Image Types:
5794 ------------------------------
5795
5796 U-Boot supports the following image types:
5797
5798 "Standalone Programs" are directly runnable in the environment
5799 provided by U-Boot; it is expected that (if they behave
5800 well) you can continue to work in U-Boot after return from
5801 the Standalone Program.
5802 "OS Kernel Images" are usually images of some Embedded OS which
5803 will take over control completely. Usually these programs
5804 will install their own set of exception handlers, device
5805 drivers, set up the MMU, etc. - this means, that you cannot
5806 expect to re-enter U-Boot except by resetting the CPU.
5807 "RAMDisk Images" are more or less just data blocks, and their
5808 parameters (address, size) are passed to an OS kernel that is
5809 being started.
5810 "Multi-File Images" contain several images, typically an OS
5811 (Linux) kernel image and one or more data images like
5812 RAMDisks. This construct is useful for instance when you want
5813 to boot over the network using BOOTP etc., where the boot
5814 server provides just a single image file, but you want to get
5815 for instance an OS kernel and a RAMDisk image.
5816
5817 "Multi-File Images" start with a list of image sizes, each
5818 image size (in bytes) specified by an "uint32_t" in network
5819 byte order. This list is terminated by an "(uint32_t)0".
5820 Immediately after the terminating 0 follow the images, one by
5821 one, all aligned on "uint32_t" boundaries (size rounded up to
5822 a multiple of 4 bytes).
5823
5824 "Firmware Images" are binary images containing firmware (like
5825 U-Boot or FPGA images) which usually will be programmed to
5826 flash memory.
5827
5828 "Script files" are command sequences that will be executed by
5829 U-Boot's command interpreter; this feature is especially
5830 useful when you configure U-Boot to use a real shell (hush)
5831 as command interpreter.
5832
5833 Booting the Linux zImage:
5834 -------------------------
5835
5836 On some platforms, it's possible to boot Linux zImage. This is done
5837 using the "bootz" command. The syntax of "bootz" command is the same
5838 as the syntax of "bootm" command.
5839
5840 Note, defining the CONFIG_SUPPORT_RAW_INITRD allows user to supply
5841 kernel with raw initrd images. The syntax is slightly different, the
5842 address of the initrd must be augmented by it's size, in the following
5843 format: "<initrd addres>:<initrd size>".
5844
5845
5846 Standalone HOWTO:
5847 =================
5848
5849 One of the features of U-Boot is that you can dynamically load and
5850 run "standalone" applications, which can use some resources of
5851 U-Boot like console I/O functions or interrupt services.
5852
5853 Two simple examples are included with the sources:
5854
5855 "Hello World" Demo:
5856 -------------------
5857
5858 'examples/hello_world.c' contains a small "Hello World" Demo
5859 application; it is automatically compiled when you build U-Boot.
5860 It's configured to run at address 0x00040004, so you can play with it
5861 like that:
5862
5863 => loads
5864 ## Ready for S-Record download ...
5865 ~>examples/hello_world.srec
5866 1 2 3 4 5 6 7 8 9 10 11 ...
5867 [file transfer complete]
5868 [connected]
5869 ## Start Addr = 0x00040004
5870
5871 => go 40004 Hello World! This is a test.
5872 ## Starting application at 0x00040004 ...
5873 Hello World
5874 argc = 7
5875 argv[0] = "40004"
5876 argv[1] = "Hello"
5877 argv[2] = "World!"
5878 argv[3] = "This"
5879 argv[4] = "is"
5880 argv[5] = "a"
5881 argv[6] = "test."
5882 argv[7] = "<NULL>"
5883 Hit any key to exit ...
5884
5885 ## Application terminated, rc = 0x0
5886
5887 Another example, which demonstrates how to register a CPM interrupt
5888 handler with the U-Boot code, can be found in 'examples/timer.c'.
5889 Here, a CPM timer is set up to generate an interrupt every second.
5890 The interrupt service routine is trivial, just printing a '.'
5891 character, but this is just a demo program. The application can be
5892 controlled by the following keys:
5893
5894 ? - print current values og the CPM Timer registers
5895 b - enable interrupts and start timer
5896 e - stop timer and disable interrupts
5897 q - quit application
5898
5899 => loads
5900 ## Ready for S-Record download ...
5901 ~>examples/timer.srec
5902 1 2 3 4 5 6 7 8 9 10 11 ...
5903 [file transfer complete]
5904 [connected]
5905 ## Start Addr = 0x00040004
5906
5907 => go 40004
5908 ## Starting application at 0x00040004 ...
5909 TIMERS=0xfff00980
5910 Using timer 1
5911 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
5912
5913 Hit 'b':
5914 [q, b, e, ?] Set interval 1000000 us
5915 Enabling timer
5916 Hit '?':
5917 [q, b, e, ?] ........
5918 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
5919 Hit '?':
5920 [q, b, e, ?] .
5921 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
5922 Hit '?':
5923 [q, b, e, ?] .
5924 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
5925 Hit '?':
5926 [q, b, e, ?] .
5927 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
5928 Hit 'e':
5929 [q, b, e, ?] ...Stopping timer
5930 Hit 'q':
5931 [q, b, e, ?] ## Application terminated, rc = 0x0
5932
5933
5934 Minicom warning:
5935 ================
5936
5937 Over time, many people have reported problems when trying to use the
5938 "minicom" terminal emulation program for serial download. I (wd)
5939 consider minicom to be broken, and recommend not to use it. Under
5940 Unix, I recommend to use C-Kermit for general purpose use (and
5941 especially for kermit binary protocol download ("loadb" command), and
5942 use "cu" for S-Record download ("loads" command). See
5943 http://www.denx.de/wiki/view/DULG/SystemSetup#Section_4.3.
5944 for help with kermit.
5945
5946
5947 Nevertheless, if you absolutely want to use it try adding this
5948 configuration to your "File transfer protocols" section:
5949
5950 Name Program Name U/D FullScr IO-Red. Multi
5951 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
5952 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
5953
5954
5955 NetBSD Notes:
5956 =============
5957
5958 Starting at version 0.9.2, U-Boot supports NetBSD both as host
5959 (build U-Boot) and target system (boots NetBSD/mpc8xx).
5960
5961 Building requires a cross environment; it is known to work on
5962 NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
5963 need gmake since the Makefiles are not compatible with BSD make).
5964 Note that the cross-powerpc package does not install include files;
5965 attempting to build U-Boot will fail because <machine/ansi.h> is
5966 missing. This file has to be installed and patched manually:
5967
5968 # cd /usr/pkg/cross/powerpc-netbsd/include
5969 # mkdir powerpc
5970 # ln -s powerpc machine
5971 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
5972 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
5973
5974 Native builds *don't* work due to incompatibilities between native
5975 and U-Boot include files.
5976
5977 Booting assumes that (the first part of) the image booted is a
5978 stage-2 loader which in turn loads and then invokes the kernel
5979 proper. Loader sources will eventually appear in the NetBSD source
5980 tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
5981 meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz
5982
5983
5984 Implementation Internals:
5985 =========================
5986
5987 The following is not intended to be a complete description of every
5988 implementation detail. However, it should help to understand the
5989 inner workings of U-Boot and make it easier to port it to custom
5990 hardware.
5991
5992
5993 Initial Stack, Global Data:
5994 ---------------------------
5995
5996 The implementation of U-Boot is complicated by the fact that U-Boot
5997 starts running out of ROM (flash memory), usually without access to
5998 system RAM (because the memory controller is not initialized yet).
5999 This means that we don't have writable Data or BSS segments, and BSS
6000 is not initialized as zero. To be able to get a C environment working
6001 at all, we have to allocate at least a minimal stack. Implementation
6002 options for this are defined and restricted by the CPU used: Some CPU
6003 models provide on-chip memory (like the IMMR area on MPC8xx and
6004 MPC826x processors), on others (parts of) the data cache can be
6005 locked as (mis-) used as memory, etc.
6006
6007 Chris Hallinan posted a good summary of these issues to the
6008 U-Boot mailing list:
6009
6010 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
6011 From: "Chris Hallinan" <clh@net1plus.com>
6012 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
6013 ...
6014
6015 Correct me if I'm wrong, folks, but the way I understand it
6016 is this: Using DCACHE as initial RAM for Stack, etc, does not
6017 require any physical RAM backing up the cache. The cleverness
6018 is that the cache is being used as a temporary supply of
6019 necessary storage before the SDRAM controller is setup. It's
6020 beyond the scope of this list to explain the details, but you
6021 can see how this works by studying the cache architecture and
6022 operation in the architecture and processor-specific manuals.
6023
6024 OCM is On Chip Memory, which I believe the 405GP has 4K. It
6025 is another option for the system designer to use as an
6026 initial stack/RAM area prior to SDRAM being available. Either
6027 option should work for you. Using CS 4 should be fine if your
6028 board designers haven't used it for something that would
6029 cause you grief during the initial boot! It is frequently not
6030 used.
6031
6032 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere
6033 with your processor/board/system design. The default value
6034 you will find in any recent u-boot distribution in
6035 walnut.h should work for you. I'd set it to a value larger
6036 than your SDRAM module. If you have a 64MB SDRAM module, set
6037 it above 400_0000. Just make sure your board has no resources
6038 that are supposed to respond to that address! That code in
6039 start.S has been around a while and should work as is when
6040 you get the config right.
6041
6042 -Chris Hallinan
6043 DS4.COM, Inc.
6044
6045 It is essential to remember this, since it has some impact on the C
6046 code for the initialization procedures:
6047
6048 * Initialized global data (data segment) is read-only. Do not attempt
6049 to write it.
6050
6051 * Do not use any uninitialized global data (or implicitly initialized
6052 as zero data - BSS segment) at all - this is undefined, initiali-
6053 zation is performed later (when relocating to RAM).
6054
6055 * Stack space is very limited. Avoid big data buffers or things like
6056 that.
6057
6058 Having only the stack as writable memory limits means we cannot use
6059 normal global data to share information between the code. But it
6060 turned out that the implementation of U-Boot can be greatly
6061 simplified by making a global data structure (gd_t) available to all
6062 functions. We could pass a pointer to this data as argument to _all_
6063 functions, but this would bloat the code. Instead we use a feature of
6064 the GCC compiler (Global Register Variables) to share the data: we
6065 place a pointer (gd) to the global data into a register which we
6066 reserve for this purpose.
6067
6068 When choosing a register for such a purpose we are restricted by the
6069 relevant (E)ABI specifications for the current architecture, and by
6070 GCC's implementation.
6071
6072 For PowerPC, the following registers have specific use:
6073 R1: stack pointer
6074 R2: reserved for system use
6075 R3-R4: parameter passing and return values
6076 R5-R10: parameter passing
6077 R13: small data area pointer
6078 R30: GOT pointer
6079 R31: frame pointer
6080
6081 (U-Boot also uses R12 as internal GOT pointer. r12
6082 is a volatile register so r12 needs to be reset when
6083 going back and forth between asm and C)
6084
6085 ==> U-Boot will use R2 to hold a pointer to the global data
6086
6087 Note: on PPC, we could use a static initializer (since the
6088 address of the global data structure is known at compile time),
6089 but it turned out that reserving a register results in somewhat
6090 smaller code - although the code savings are not that big (on
6091 average for all boards 752 bytes for the whole U-Boot image,
6092 624 text + 127 data).
6093
6094 On Blackfin, the normal C ABI (except for P3) is followed as documented here:
6095 http://docs.blackfin.uclinux.org/doku.php?id=application_binary_interface
6096
6097 ==> U-Boot will use P3 to hold a pointer to the global data
6098
6099 On ARM, the following registers are used:
6100
6101 R0: function argument word/integer result
6102 R1-R3: function argument word
6103 R9: platform specific
6104 R10: stack limit (used only if stack checking is enabled)
6105 R11: argument (frame) pointer
6106 R12: temporary workspace
6107 R13: stack pointer
6108 R14: link register
6109 R15: program counter
6110
6111 ==> U-Boot will use R9 to hold a pointer to the global data
6112
6113 Note: on ARM, only R_ARM_RELATIVE relocations are supported.
6114
6115 On Nios II, the ABI is documented here:
6116 http://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf
6117
6118 ==> U-Boot will use gp to hold a pointer to the global data
6119
6120 Note: on Nios II, we give "-G0" option to gcc and don't use gp
6121 to access small data sections, so gp is free.
6122
6123 On NDS32, the following registers are used:
6124
6125 R0-R1: argument/return
6126 R2-R5: argument
6127 R15: temporary register for assembler
6128 R16: trampoline register
6129 R28: frame pointer (FP)
6130 R29: global pointer (GP)
6131 R30: link register (LP)
6132 R31: stack pointer (SP)
6133 PC: program counter (PC)
6134
6135 ==> U-Boot will use R10 to hold a pointer to the global data
6136
6137 NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope,
6138 or current versions of GCC may "optimize" the code too much.
6139
6140 Memory Management:
6141 ------------------
6142
6143 U-Boot runs in system state and uses physical addresses, i.e. the
6144 MMU is not used either for address mapping nor for memory protection.
6145
6146 The available memory is mapped to fixed addresses using the memory
6147 controller. In this process, a contiguous block is formed for each
6148 memory type (Flash, SDRAM, SRAM), even when it consists of several
6149 physical memory banks.
6150
6151 U-Boot is installed in the first 128 kB of the first Flash bank (on
6152 TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
6153 booting and sizing and initializing DRAM, the code relocates itself
6154 to the upper end of DRAM. Immediately below the U-Boot code some
6155 memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN
6156 configuration setting]. Below that, a structure with global Board
6157 Info data is placed, followed by the stack (growing downward).
6158
6159 Additionally, some exception handler code is copied to the low 8 kB
6160 of DRAM (0x00000000 ... 0x00001FFF).
6161
6162 So a typical memory configuration with 16 MB of DRAM could look like
6163 this:
6164
6165 0x0000 0000 Exception Vector code
6166 :
6167 0x0000 1FFF
6168 0x0000 2000 Free for Application Use
6169 :
6170 :
6171
6172 :
6173 :
6174 0x00FB FF20 Monitor Stack (Growing downward)
6175 0x00FB FFAC Board Info Data and permanent copy of global data
6176 0x00FC 0000 Malloc Arena
6177 :
6178 0x00FD FFFF
6179 0x00FE 0000 RAM Copy of Monitor Code
6180 ... eventually: LCD or video framebuffer
6181 ... eventually: pRAM (Protected RAM - unchanged by reset)
6182 0x00FF FFFF [End of RAM]
6183
6184
6185 System Initialization:
6186 ----------------------
6187
6188 In the reset configuration, U-Boot starts at the reset entry point
6189 (on most PowerPC systems at address 0x00000100). Because of the reset
6190 configuration for CS0# this is a mirror of the on board Flash memory.
6191 To be able to re-map memory U-Boot then jumps to its link address.
6192 To be able to implement the initialization code in C, a (small!)
6193 initial stack is set up in the internal Dual Ported RAM (in case CPUs
6194 which provide such a feature like MPC8xx or MPC8260), or in a locked
6195 part of the data cache. After that, U-Boot initializes the CPU core,
6196 the caches and the SIU.
6197
6198 Next, all (potentially) available memory banks are mapped using a
6199 preliminary mapping. For example, we put them on 512 MB boundaries
6200 (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
6201 on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
6202 programmed for SDRAM access. Using the temporary configuration, a
6203 simple memory test is run that determines the size of the SDRAM
6204 banks.
6205
6206 When there is more than one SDRAM bank, and the banks are of
6207 different size, the largest is mapped first. For equal size, the first
6208 bank (CS2#) is mapped first. The first mapping is always for address
6209 0x00000000, with any additional banks following immediately to create
6210 contiguous memory starting from 0.
6211
6212 Then, the monitor installs itself at the upper end of the SDRAM area
6213 and allocates memory for use by malloc() and for the global Board
6214 Info data; also, the exception vector code is copied to the low RAM
6215 pages, and the final stack is set up.
6216
6217 Only after this relocation will you have a "normal" C environment;
6218 until that you are restricted in several ways, mostly because you are
6219 running from ROM, and because the code will have to be relocated to a
6220 new address in RAM.
6221
6222
6223 U-Boot Porting Guide:
6224 ----------------------
6225
6226 [Based on messages by Jerry Van Baren in the U-Boot-Users mailing
6227 list, October 2002]
6228
6229
6230 int main(int argc, char *argv[])
6231 {
6232 sighandler_t no_more_time;
6233
6234 signal(SIGALRM, no_more_time);
6235 alarm(PROJECT_DEADLINE - toSec (3 * WEEK));
6236
6237 if (available_money > available_manpower) {
6238 Pay consultant to port U-Boot;
6239 return 0;
6240 }
6241
6242 Download latest U-Boot source;
6243
6244 Subscribe to u-boot mailing list;
6245
6246 if (clueless)
6247 email("Hi, I am new to U-Boot, how do I get started?");
6248
6249 while (learning) {
6250 Read the README file in the top level directory;
6251 Read http://www.denx.de/twiki/bin/view/DULG/Manual;
6252 Read applicable doc/*.README;
6253 Read the source, Luke;
6254 /* find . -name "*.[chS]" | xargs grep -i <keyword> */
6255 }
6256
6257 if (available_money > toLocalCurrency ($2500))
6258 Buy a BDI3000;
6259 else
6260 Add a lot of aggravation and time;
6261
6262 if (a similar board exists) { /* hopefully... */
6263 cp -a board/<similar> board/<myboard>
6264 cp include/configs/<similar>.h include/configs/<myboard>.h
6265 } else {
6266 Create your own board support subdirectory;
6267 Create your own board include/configs/<myboard>.h file;
6268 }
6269 Edit new board/<myboard> files
6270 Edit new include/configs/<myboard>.h
6271
6272 while (!accepted) {
6273 while (!running) {
6274 do {
6275 Add / modify source code;
6276 } until (compiles);
6277 Debug;
6278 if (clueless)
6279 email("Hi, I am having problems...");
6280 }
6281 Send patch file to the U-Boot email list;
6282 if (reasonable critiques)
6283 Incorporate improvements from email list code review;
6284 else
6285 Defend code as written;
6286 }
6287
6288 return 0;
6289 }
6290
6291 void no_more_time (int sig)
6292 {
6293 hire_a_guru();
6294 }
6295
6296
6297 Coding Standards:
6298 -----------------
6299
6300 All contributions to U-Boot should conform to the Linux kernel
6301 coding style; see the file "Documentation/CodingStyle" and the script
6302 "scripts/Lindent" in your Linux kernel source directory.
6303
6304 Source files originating from a different project (for example the
6305 MTD subsystem) are generally exempt from these guidelines and are not
6306 reformatted to ease subsequent migration to newer versions of those
6307 sources.
6308
6309 Please note that U-Boot is implemented in C (and to some small parts in
6310 Assembler); no C++ is used, so please do not use C++ style comments (//)
6311 in your code.
6312
6313 Please also stick to the following formatting rules:
6314 - remove any trailing white space
6315 - use TAB characters for indentation and vertical alignment, not spaces
6316 - make sure NOT to use DOS '\r\n' line feeds
6317 - do not add more than 2 consecutive empty lines to source files
6318 - do not add trailing empty lines to source files
6319
6320 Submissions which do not conform to the standards may be returned
6321 with a request to reformat the changes.
6322
6323
6324 Submitting Patches:
6325 -------------------
6326
6327 Since the number of patches for U-Boot is growing, we need to
6328 establish some rules. Submissions which do not conform to these rules
6329 may be rejected, even when they contain important and valuable stuff.
6330
6331 Please see http://www.denx.de/wiki/U-Boot/Patches for details.
6332
6333 Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>;
6334 see http://lists.denx.de/mailman/listinfo/u-boot
6335
6336 When you send a patch, please include the following information with
6337 it:
6338
6339 * For bug fixes: a description of the bug and how your patch fixes
6340 this bug. Please try to include a way of demonstrating that the
6341 patch actually fixes something.
6342
6343 * For new features: a description of the feature and your
6344 implementation.
6345
6346 * A CHANGELOG entry as plaintext (separate from the patch)
6347
6348 * For major contributions, add a MAINTAINERS file with your
6349 information and associated file and directory references.
6350
6351 * When you add support for a new board, don't forget to add a
6352 maintainer e-mail address to the boards.cfg file, too.
6353
6354 * If your patch adds new configuration options, don't forget to
6355 document these in the README file.
6356
6357 * The patch itself. If you are using git (which is *strongly*
6358 recommended) you can easily generate the patch using the
6359 "git format-patch". If you then use "git send-email" to send it to
6360 the U-Boot mailing list, you will avoid most of the common problems
6361 with some other mail clients.
6362
6363 If you cannot use git, use "diff -purN OLD NEW". If your version of
6364 diff does not support these options, then get the latest version of
6365 GNU diff.
6366
6367 The current directory when running this command shall be the parent
6368 directory of the U-Boot source tree (i. e. please make sure that
6369 your patch includes sufficient directory information for the
6370 affected files).
6371
6372 We prefer patches as plain text. MIME attachments are discouraged,
6373 and compressed attachments must not be used.
6374
6375 * If one logical set of modifications affects or creates several
6376 files, all these changes shall be submitted in a SINGLE patch file.
6377
6378 * Changesets that contain different, unrelated modifications shall be
6379 submitted as SEPARATE patches, one patch per changeset.
6380
6381
6382 Notes:
6383
6384 * Before sending the patch, run the buildman script on your patched
6385 source tree and make sure that no errors or warnings are reported
6386 for any of the boards.
6387
6388 * Keep your modifications to the necessary minimum: A patch
6389 containing several unrelated changes or arbitrary reformats will be
6390 returned with a request to re-formatting / split it.
6391
6392 * If you modify existing code, make sure that your new code does not
6393 add to the memory footprint of the code ;-) Small is beautiful!
6394 When adding new features, these should compile conditionally only
6395 (using #ifdef), and the resulting code with the new feature
6396 disabled must not need more memory than the old code without your
6397 modification.
6398
6399 * Remember that there is a size limit of 100 kB per message on the
6400 u-boot mailing list. Bigger patches will be moderated. If they are
6401 reasonable and not too big, they will be acknowledged. But patches
6402 bigger than the size limit should be avoided.