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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 candidate 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 /m68k Files generic to m68k architecture
140 /microblaze Files generic to microblaze architecture
141 /mips Files generic to MIPS architecture
142 /nds32 Files generic to NDS32 architecture
143 /nios2 Files generic to Altera NIOS2 architecture
144 /openrisc Files generic to OpenRISC architecture
145 /powerpc Files generic to PowerPC architecture
146 /riscv Files generic to RISC-V architecture
147 /sandbox Files generic to HW-independent "sandbox"
148 /sh Files generic to SH architecture
149 /x86 Files generic to x86 architecture
150 /api Machine/arch independent API for external apps
151 /board Board dependent files
152 /cmd U-Boot commands functions
153 /common Misc architecture independent functions
154 /configs Board default configuration files
155 /disk Code for disk drive partition handling
156 /doc Documentation (don't expect too much)
157 /drivers Commonly used device drivers
158 /dts Contains Makefile for building internal U-Boot fdt.
159 /examples Example code for standalone applications, etc.
160 /fs Filesystem code (cramfs, ext2, jffs2, etc.)
161 /include Header Files
162 /lib Library routines generic to all architectures
163 /Licenses Various license files
164 /net Networking code
165 /post Power On Self Test
166 /scripts Various build scripts and Makefiles
167 /test Various unit test files
168 /tools Tools to build S-Record or U-Boot images, etc.
169
170 Software Configuration:
171 =======================
172
173 Configuration is usually done using C preprocessor defines; the
174 rationale behind that is to avoid dead code whenever possible.
175
176 There are two classes of configuration variables:
177
178 * Configuration _OPTIONS_:
179 These are selectable by the user and have names beginning with
180 "CONFIG_".
181
182 * Configuration _SETTINGS_:
183 These depend on the hardware etc. and should not be meddled with if
184 you don't know what you're doing; they have names beginning with
185 "CONFIG_SYS_".
186
187 Previously, all configuration was done by hand, which involved creating
188 symbolic links and editing configuration files manually. More recently,
189 U-Boot has added the Kbuild infrastructure used by the Linux kernel,
190 allowing you to use the "make menuconfig" command to configure your
191 build.
192
193
194 Selection of Processor Architecture and Board Type:
195 ---------------------------------------------------
196
197 For all supported boards there are ready-to-use default
198 configurations available; just type "make <board_name>_defconfig".
199
200 Example: For a TQM823L module type:
201
202 cd u-boot
203 make TQM823L_defconfig
204
205 Note: If you're looking for the default configuration file for a board
206 you're sure used to be there but is now missing, check the file
207 doc/README.scrapyard for a list of no longer supported boards.
208
209 Sandbox Environment:
210 --------------------
211
212 U-Boot can be built natively to run on a Linux host using the 'sandbox'
213 board. This allows feature development which is not board- or architecture-
214 specific to be undertaken on a native platform. The sandbox is also used to
215 run some of U-Boot's tests.
216
217 See board/sandbox/README.sandbox for more details.
218
219
220 Board Initialisation Flow:
221 --------------------------
222
223 This is the intended start-up flow for boards. This should apply for both
224 SPL and U-Boot proper (i.e. they both follow the same rules).
225
226 Note: "SPL" stands for "Secondary Program Loader," which is explained in
227 more detail later in this file.
228
229 At present, SPL mostly uses a separate code path, but the function names
230 and roles of each function are the same. Some boards or architectures
231 may not conform to this. At least most ARM boards which use
232 CONFIG_SPL_FRAMEWORK conform to this.
233
234 Execution typically starts with an architecture-specific (and possibly
235 CPU-specific) start.S file, such as:
236
237 - arch/arm/cpu/armv7/start.S
238 - arch/powerpc/cpu/mpc83xx/start.S
239 - arch/mips/cpu/start.S
240
241 and so on. From there, three functions are called; the purpose and
242 limitations of each of these functions are described below.
243
244 lowlevel_init():
245 - purpose: essential init to permit execution to reach board_init_f()
246 - no global_data or BSS
247 - there is no stack (ARMv7 may have one but it will soon be removed)
248 - must not set up SDRAM or use console
249 - must only do the bare minimum to allow execution to continue to
250 board_init_f()
251 - this is almost never needed
252 - return normally from this function
253
254 board_init_f():
255 - purpose: set up the machine ready for running board_init_r():
256 i.e. SDRAM and serial UART
257 - global_data is available
258 - stack is in SRAM
259 - BSS is not available, so you cannot use global/static variables,
260 only stack variables and global_data
261
262 Non-SPL-specific notes:
263 - dram_init() is called to set up DRAM. If already done in SPL this
264 can do nothing
265
266 SPL-specific notes:
267 - you can override the entire board_init_f() function with your own
268 version as needed.
269 - preloader_console_init() can be called here in extremis
270 - should set up SDRAM, and anything needed to make the UART work
271 - these is no need to clear BSS, it will be done by crt0.S
272 - must return normally from this function (don't call board_init_r()
273 directly)
274
275 Here the BSS is cleared. For SPL, if CONFIG_SPL_STACK_R is defined, then at
276 this point the stack and global_data are relocated to below
277 CONFIG_SPL_STACK_R_ADDR. For non-SPL, U-Boot is relocated to run at the top of
278 memory.
279
280 board_init_r():
281 - purpose: main execution, common code
282 - global_data is available
283 - SDRAM is available
284 - BSS is available, all static/global variables can be used
285 - execution eventually continues to main_loop()
286
287 Non-SPL-specific notes:
288 - U-Boot is relocated to the top of memory and is now running from
289 there.
290
291 SPL-specific notes:
292 - stack is optionally in SDRAM, if CONFIG_SPL_STACK_R is defined and
293 CONFIG_SPL_STACK_R_ADDR points into SDRAM
294 - preloader_console_init() can be called here - typically this is
295 done by selecting CONFIG_SPL_BOARD_INIT and then supplying a
296 spl_board_init() function containing this call
297 - loads U-Boot or (in falcon mode) Linux
298
299
300
301 Configuration Options:
302 ----------------------
303
304 Configuration depends on the combination of board and CPU type; all
305 such information is kept in a configuration file
306 "include/configs/<board_name>.h".
307
308 Example: For a TQM823L module, all configuration settings are in
309 "include/configs/TQM823L.h".
310
311
312 Many of the options are named exactly as the corresponding Linux
313 kernel configuration options. The intention is to make it easier to
314 build a config tool - later.
315
316 - ARM Platform Bus Type(CCI):
317 CoreLink Cache Coherent Interconnect (CCI) is ARM BUS which
318 provides full cache coherency between two clusters of multi-core
319 CPUs and I/O coherency for devices and I/O masters
320
321 CONFIG_SYS_FSL_HAS_CCI400
322
323 Defined For SoC that has cache coherent interconnect
324 CCN-400
325
326 CONFIG_SYS_FSL_HAS_CCN504
327
328 Defined for SoC that has cache coherent interconnect CCN-504
329
330 The following options need to be configured:
331
332 - CPU Type: Define exactly one, e.g. CONFIG_MPC85XX.
333
334 - Board Type: Define exactly one, e.g. CONFIG_MPC8540ADS.
335
336 - Marvell Family Member
337 CONFIG_SYS_MVFS - define it if you want to enable
338 multiple fs option at one time
339 for marvell soc family
340
341 - 85xx CPU Options:
342 CONFIG_SYS_PPC64
343
344 Specifies that the core is a 64-bit PowerPC implementation (implements
345 the "64" category of the Power ISA). This is necessary for ePAPR
346 compliance, among other possible reasons.
347
348 CONFIG_SYS_FSL_TBCLK_DIV
349
350 Defines the core time base clock divider ratio compared to the
351 system clock. On most PQ3 devices this is 8, on newer QorIQ
352 devices it can be 16 or 32. The ratio varies from SoC to Soc.
353
354 CONFIG_SYS_FSL_PCIE_COMPAT
355
356 Defines the string to utilize when trying to match PCIe device
357 tree nodes for the given platform.
358
359 CONFIG_SYS_FSL_ERRATUM_A004510
360
361 Enables a workaround for erratum A004510. If set,
362 then CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV and
363 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY must be set.
364
365 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV
366 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV2 (optional)
367
368 Defines one or two SoC revisions (low 8 bits of SVR)
369 for which the A004510 workaround should be applied.
370
371 The rest of SVR is either not relevant to the decision
372 of whether the erratum is present (e.g. p2040 versus
373 p2041) or is implied by the build target, which controls
374 whether CONFIG_SYS_FSL_ERRATUM_A004510 is set.
375
376 See Freescale App Note 4493 for more information about
377 this erratum.
378
379 CONFIG_A003399_NOR_WORKAROUND
380 Enables a workaround for IFC erratum A003399. It is only
381 required during NOR boot.
382
383 CONFIG_A008044_WORKAROUND
384 Enables a workaround for T1040/T1042 erratum A008044. It is only
385 required during NAND boot and valid for Rev 1.0 SoC revision
386
387 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY
388
389 This is the value to write into CCSR offset 0x18600
390 according to the A004510 workaround.
391
392 CONFIG_SYS_FSL_DSP_DDR_ADDR
393 This value denotes start offset of DDR memory which is
394 connected exclusively to the DSP cores.
395
396 CONFIG_SYS_FSL_DSP_M2_RAM_ADDR
397 This value denotes start offset of M2 memory
398 which is directly connected to the DSP core.
399
400 CONFIG_SYS_FSL_DSP_M3_RAM_ADDR
401 This value denotes start offset of M3 memory which is directly
402 connected to the DSP core.
403
404 CONFIG_SYS_FSL_DSP_CCSRBAR_DEFAULT
405 This value denotes start offset of DSP CCSR space.
406
407 CONFIG_SYS_FSL_SINGLE_SOURCE_CLK
408 Single Source Clock is clocking mode present in some of FSL SoC's.
409 In this mode, a single differential clock is used to supply
410 clocks to the sysclock, ddrclock and usbclock.
411
412 CONFIG_SYS_CPC_REINIT_F
413 This CONFIG is defined when the CPC is configured as SRAM at the
414 time of U-Boot entry and is required to be re-initialized.
415
416 CONFIG_DEEP_SLEEP
417 Indicates this SoC supports deep sleep feature. If deep sleep is
418 supported, core will start to execute uboot when wakes up.
419
420 - Generic CPU options:
421 CONFIG_SYS_BIG_ENDIAN, CONFIG_SYS_LITTLE_ENDIAN
422
423 Defines the endianess of the CPU. Implementation of those
424 values is arch specific.
425
426 CONFIG_SYS_FSL_DDR
427 Freescale DDR driver in use. This type of DDR controller is
428 found in mpc83xx, mpc85xx, mpc86xx as well as some ARM core
429 SoCs.
430
431 CONFIG_SYS_FSL_DDR_ADDR
432 Freescale DDR memory-mapped register base.
433
434 CONFIG_SYS_FSL_DDR_EMU
435 Specify emulator support for DDR. Some DDR features such as
436 deskew training are not available.
437
438 CONFIG_SYS_FSL_DDRC_GEN1
439 Freescale DDR1 controller.
440
441 CONFIG_SYS_FSL_DDRC_GEN2
442 Freescale DDR2 controller.
443
444 CONFIG_SYS_FSL_DDRC_GEN3
445 Freescale DDR3 controller.
446
447 CONFIG_SYS_FSL_DDRC_GEN4
448 Freescale DDR4 controller.
449
450 CONFIG_SYS_FSL_DDRC_ARM_GEN3
451 Freescale DDR3 controller for ARM-based SoCs.
452
453 CONFIG_SYS_FSL_DDR1
454 Board config to use DDR1. It can be enabled for SoCs with
455 Freescale DDR1 or DDR2 controllers, depending on the board
456 implemetation.
457
458 CONFIG_SYS_FSL_DDR2
459 Board config to use DDR2. It can be enabled for SoCs with
460 Freescale DDR2 or DDR3 controllers, depending on the board
461 implementation.
462
463 CONFIG_SYS_FSL_DDR3
464 Board config to use DDR3. It can be enabled for SoCs with
465 Freescale DDR3 or DDR3L controllers.
466
467 CONFIG_SYS_FSL_DDR3L
468 Board config to use DDR3L. It can be enabled for SoCs with
469 DDR3L controllers.
470
471 CONFIG_SYS_FSL_DDR4
472 Board config to use DDR4. It can be enabled for SoCs with
473 DDR4 controllers.
474
475 CONFIG_SYS_FSL_IFC_BE
476 Defines the IFC controller register space as Big Endian
477
478 CONFIG_SYS_FSL_IFC_LE
479 Defines the IFC controller register space as Little Endian
480
481 CONFIG_SYS_FSL_IFC_CLK_DIV
482 Defines divider of platform clock(clock input to IFC controller).
483
484 CONFIG_SYS_FSL_LBC_CLK_DIV
485 Defines divider of platform clock(clock input to eLBC controller).
486
487 CONFIG_SYS_FSL_PBL_PBI
488 It enables addition of RCW (Power on reset configuration) in built image.
489 Please refer doc/README.pblimage for more details
490
491 CONFIG_SYS_FSL_PBL_RCW
492 It adds PBI(pre-boot instructions) commands in u-boot build image.
493 PBI commands can be used to configure SoC before it starts the execution.
494 Please refer doc/README.pblimage for more details
495
496 CONFIG_SPL_FSL_PBL
497 It adds a target to create boot binary having SPL binary in PBI format
498 concatenated with u-boot binary.
499
500 CONFIG_SYS_FSL_DDR_BE
501 Defines the DDR controller register space as Big Endian
502
503 CONFIG_SYS_FSL_DDR_LE
504 Defines the DDR controller register space as Little Endian
505
506 CONFIG_SYS_FSL_DDR_SDRAM_BASE_PHY
507 Physical address from the view of DDR controllers. It is the
508 same as CONFIG_SYS_DDR_SDRAM_BASE for all Power SoCs. But
509 it could be different for ARM SoCs.
510
511 CONFIG_SYS_FSL_DDR_INTLV_256B
512 DDR controller interleaving on 256-byte. This is a special
513 interleaving mode, handled by Dickens for Freescale layerscape
514 SoCs with ARM core.
515
516 CONFIG_SYS_FSL_DDR_MAIN_NUM_CTRLS
517 Number of controllers used as main memory.
518
519 CONFIG_SYS_FSL_OTHER_DDR_NUM_CTRLS
520 Number of controllers used for other than main memory.
521
522 CONFIG_SYS_FSL_HAS_DP_DDR
523 Defines the SoC has DP-DDR used for DPAA.
524
525 CONFIG_SYS_FSL_SEC_BE
526 Defines the SEC controller register space as Big Endian
527
528 CONFIG_SYS_FSL_SEC_LE
529 Defines the SEC controller register space as Little Endian
530
531 - MIPS CPU options:
532 CONFIG_SYS_INIT_SP_OFFSET
533
534 Offset relative to CONFIG_SYS_SDRAM_BASE for initial stack
535 pointer. This is needed for the temporary stack before
536 relocation.
537
538 CONFIG_SYS_MIPS_CACHE_MODE
539
540 Cache operation mode for the MIPS CPU.
541 See also arch/mips/include/asm/mipsregs.h.
542 Possible values are:
543 CONF_CM_CACHABLE_NO_WA
544 CONF_CM_CACHABLE_WA
545 CONF_CM_UNCACHED
546 CONF_CM_CACHABLE_NONCOHERENT
547 CONF_CM_CACHABLE_CE
548 CONF_CM_CACHABLE_COW
549 CONF_CM_CACHABLE_CUW
550 CONF_CM_CACHABLE_ACCELERATED
551
552 CONFIG_SYS_XWAY_EBU_BOOTCFG
553
554 Special option for Lantiq XWAY SoCs for booting from NOR flash.
555 See also arch/mips/cpu/mips32/start.S.
556
557 CONFIG_XWAY_SWAP_BYTES
558
559 Enable compilation of tools/xway-swap-bytes needed for Lantiq
560 XWAY SoCs for booting from NOR flash. The U-Boot image needs to
561 be swapped if a flash programmer is used.
562
563 - ARM options:
564 CONFIG_SYS_EXCEPTION_VECTORS_HIGH
565
566 Select high exception vectors of the ARM core, e.g., do not
567 clear the V bit of the c1 register of CP15.
568
569 COUNTER_FREQUENCY
570 Generic timer clock source frequency.
571
572 COUNTER_FREQUENCY_REAL
573 Generic timer clock source frequency if the real clock is
574 different from COUNTER_FREQUENCY, and can only be determined
575 at run time.
576
577 - Tegra SoC options:
578 CONFIG_TEGRA_SUPPORT_NON_SECURE
579
580 Support executing U-Boot in non-secure (NS) mode. Certain
581 impossible actions will be skipped if the CPU is in NS mode,
582 such as ARM architectural timer initialization.
583
584 - Linux Kernel Interface:
585 CONFIG_CLOCKS_IN_MHZ
586
587 U-Boot stores all clock information in Hz
588 internally. For binary compatibility with older Linux
589 kernels (which expect the clocks passed in the
590 bd_info data to be in MHz) the environment variable
591 "clocks_in_mhz" can be defined so that U-Boot
592 converts clock data to MHZ before passing it to the
593 Linux kernel.
594 When CONFIG_CLOCKS_IN_MHZ is defined, a definition of
595 "clocks_in_mhz=1" is automatically included in the
596 default environment.
597
598 CONFIG_MEMSIZE_IN_BYTES [relevant for MIPS only]
599
600 When transferring memsize parameter to Linux, some versions
601 expect it to be in bytes, others in MB.
602 Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes.
603
604 CONFIG_OF_LIBFDT
605
606 New kernel versions are expecting firmware settings to be
607 passed using flattened device trees (based on open firmware
608 concepts).
609
610 CONFIG_OF_LIBFDT
611 * New libfdt-based support
612 * Adds the "fdt" command
613 * The bootm command automatically updates the fdt
614
615 OF_TBCLK - The timebase frequency.
616 OF_STDOUT_PATH - The path to the console device
617
618 boards with QUICC Engines require OF_QE to set UCC MAC
619 addresses
620
621 CONFIG_OF_BOARD_SETUP
622
623 Board code has addition modification that it wants to make
624 to the flat device tree before handing it off to the kernel
625
626 CONFIG_OF_SYSTEM_SETUP
627
628 Other code has addition modification that it wants to make
629 to the flat device tree before handing it off to the kernel.
630 This causes ft_system_setup() to be called before booting
631 the kernel.
632
633 CONFIG_OF_IDE_FIXUP
634
635 U-Boot can detect if an IDE device is present or not.
636 If not, and this new config option is activated, U-Boot
637 removes the ATA node from the DTS before booting Linux,
638 so the Linux IDE driver does not probe the device and
639 crash. This is needed for buggy hardware (uc101) where
640 no pull down resistor is connected to the signal IDE5V_DD7.
641
642 CONFIG_MACH_TYPE [relevant for ARM only][mandatory]
643
644 This setting is mandatory for all boards that have only one
645 machine type and must be used to specify the machine type
646 number as it appears in the ARM machine registry
647 (see http://www.arm.linux.org.uk/developer/machines/).
648 Only boards that have multiple machine types supported
649 in a single configuration file and the machine type is
650 runtime discoverable, do not have to use this setting.
651
652 - vxWorks boot parameters:
653
654 bootvx constructs a valid bootline using the following
655 environments variables: bootdev, bootfile, ipaddr, netmask,
656 serverip, gatewayip, hostname, othbootargs.
657 It loads the vxWorks image pointed bootfile.
658
659 Note: If a "bootargs" environment is defined, it will overwride
660 the defaults discussed just above.
661
662 - Cache Configuration:
663 CONFIG_SYS_ICACHE_OFF - Do not enable instruction cache in U-Boot
664 CONFIG_SYS_DCACHE_OFF - Do not enable data cache in U-Boot
665 CONFIG_SYS_L2CACHE_OFF- Do not enable L2 cache in U-Boot
666
667 - Cache Configuration for ARM:
668 CONFIG_SYS_L2_PL310 - Enable support for ARM PL310 L2 cache
669 controller
670 CONFIG_SYS_PL310_BASE - Physical base address of PL310
671 controller register space
672
673 - Serial Ports:
674 CONFIG_PL010_SERIAL
675
676 Define this if you want support for Amba PrimeCell PL010 UARTs.
677
678 CONFIG_PL011_SERIAL
679
680 Define this if you want support for Amba PrimeCell PL011 UARTs.
681
682 CONFIG_PL011_CLOCK
683
684 If you have Amba PrimeCell PL011 UARTs, set this variable to
685 the clock speed of the UARTs.
686
687 CONFIG_PL01x_PORTS
688
689 If you have Amba PrimeCell PL010 or PL011 UARTs on your board,
690 define this to a list of base addresses for each (supported)
691 port. See e.g. include/configs/versatile.h
692
693 CONFIG_SERIAL_HW_FLOW_CONTROL
694
695 Define this variable to enable hw flow control in serial driver.
696 Current user of this option is drivers/serial/nsl16550.c driver
697
698 - Console Baudrate:
699 CONFIG_BAUDRATE - in bps
700 Select one of the baudrates listed in
701 CONFIG_SYS_BAUDRATE_TABLE, see below.
702
703 - Autoboot Command:
704 CONFIG_BOOTCOMMAND
705 Only needed when CONFIG_BOOTDELAY is enabled;
706 define a command string that is automatically executed
707 when no character is read on the console interface
708 within "Boot Delay" after reset.
709
710 CONFIG_RAMBOOT and CONFIG_NFSBOOT
711 The value of these goes into the environment as
712 "ramboot" and "nfsboot" respectively, and can be used
713 as a convenience, when switching between booting from
714 RAM and NFS.
715
716 - Pre-Boot Commands:
717 CONFIG_PREBOOT
718
719 When this option is #defined, the existence of the
720 environment variable "preboot" will be checked
721 immediately before starting the CONFIG_BOOTDELAY
722 countdown and/or running the auto-boot command resp.
723 entering interactive mode.
724
725 This feature is especially useful when "preboot" is
726 automatically generated or modified. For an example
727 see the LWMON board specific code: here "preboot" is
728 modified when the user holds down a certain
729 combination of keys on the (special) keyboard when
730 booting the systems
731
732 - Serial Download Echo Mode:
733 CONFIG_LOADS_ECHO
734 If defined to 1, all characters received during a
735 serial download (using the "loads" command) are
736 echoed back. This might be needed by some terminal
737 emulations (like "cu"), but may as well just take
738 time on others. This setting #define's the initial
739 value of the "loads_echo" environment variable.
740
741 - Kgdb Serial Baudrate: (if CONFIG_CMD_KGDB is defined)
742 CONFIG_KGDB_BAUDRATE
743 Select one of the baudrates listed in
744 CONFIG_SYS_BAUDRATE_TABLE, see below.
745
746 - Removal of commands
747 If no commands are needed to boot, you can disable
748 CONFIG_CMDLINE to remove them. In this case, the command line
749 will not be available, and when U-Boot wants to execute the
750 boot command (on start-up) it will call board_run_command()
751 instead. This can reduce image size significantly for very
752 simple boot procedures.
753
754 - Regular expression support:
755 CONFIG_REGEX
756 If this variable is defined, U-Boot is linked against
757 the SLRE (Super Light Regular Expression) library,
758 which adds regex support to some commands, as for
759 example "env grep" and "setexpr".
760
761 - Device tree:
762 CONFIG_OF_CONTROL
763 If this variable is defined, U-Boot will use a device tree
764 to configure its devices, instead of relying on statically
765 compiled #defines in the board file. This option is
766 experimental and only available on a few boards. The device
767 tree is available in the global data as gd->fdt_blob.
768
769 U-Boot needs to get its device tree from somewhere. This can
770 be done using one of the three options below:
771
772 CONFIG_OF_EMBED
773 If this variable is defined, U-Boot will embed a device tree
774 binary in its image. This device tree file should be in the
775 board directory and called <soc>-<board>.dts. The binary file
776 is then picked up in board_init_f() and made available through
777 the global data structure as gd->fdt_blob.
778
779 CONFIG_OF_SEPARATE
780 If this variable is defined, U-Boot will build a device tree
781 binary. It will be called u-boot.dtb. Architecture-specific
782 code will locate it at run-time. Generally this works by:
783
784 cat u-boot.bin u-boot.dtb >image.bin
785
786 and in fact, U-Boot does this for you, creating a file called
787 u-boot-dtb.bin which is useful in the common case. You can
788 still use the individual files if you need something more
789 exotic.
790
791 CONFIG_OF_BOARD
792 If this variable is defined, U-Boot will use the device tree
793 provided by the board at runtime instead of embedding one with
794 the image. Only boards defining board_fdt_blob_setup() support
795 this option (see include/fdtdec.h file).
796
797 - Watchdog:
798 CONFIG_WATCHDOG
799 If this variable is defined, it enables watchdog
800 support for the SoC. There must be support in the SoC
801 specific code for a watchdog. For the 8xx
802 CPUs, the SIU Watchdog feature is enabled in the SYPCR
803 register. When supported for a specific SoC is
804 available, then no further board specific code should
805 be needed to use it.
806
807 CONFIG_HW_WATCHDOG
808 When using a watchdog circuitry external to the used
809 SoC, then define this variable and provide board
810 specific code for the "hw_watchdog_reset" function.
811
812 CONFIG_AT91_HW_WDT_TIMEOUT
813 specify the timeout in seconds. default 2 seconds.
814
815 - U-Boot Version:
816 CONFIG_VERSION_VARIABLE
817 If this variable is defined, an environment variable
818 named "ver" is created by U-Boot showing the U-Boot
819 version as printed by the "version" command.
820 Any change to this variable will be reverted at the
821 next reset.
822
823 - Real-Time Clock:
824
825 When CONFIG_CMD_DATE is selected, the type of the RTC
826 has to be selected, too. Define exactly one of the
827 following options:
828
829 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC
830 CONFIG_RTC_MC13XXX - use MC13783 or MC13892 RTC
831 CONFIG_RTC_MC146818 - use MC146818 RTC
832 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC
833 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC
834 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC
835 CONFIG_RTC_DS1339 - use Maxim, Inc. DS1339 RTC
836 CONFIG_RTC_DS164x - use Dallas DS164x RTC
837 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC
838 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC
839 CONFIG_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337
840 CONFIG_SYS_RV3029_TCR - enable trickle charger on
841 RV3029 RTC.
842
843 Note that if the RTC uses I2C, then the I2C interface
844 must also be configured. See I2C Support, below.
845
846 - GPIO Support:
847 CONFIG_PCA953X - use NXP's PCA953X series I2C GPIO
848
849 The CONFIG_SYS_I2C_PCA953X_WIDTH option specifies a list of
850 chip-ngpio pairs that tell the PCA953X driver the number of
851 pins supported by a particular chip.
852
853 Note that if the GPIO device uses I2C, then the I2C interface
854 must also be configured. See I2C Support, below.
855
856 - I/O tracing:
857 When CONFIG_IO_TRACE is selected, U-Boot intercepts all I/O
858 accesses and can checksum them or write a list of them out
859 to memory. See the 'iotrace' command for details. This is
860 useful for testing device drivers since it can confirm that
861 the driver behaves the same way before and after a code
862 change. Currently this is supported on sandbox and arm. To
863 add support for your architecture, add '#include <iotrace.h>'
864 to the bottom of arch/<arch>/include/asm/io.h and test.
865
866 Example output from the 'iotrace stats' command is below.
867 Note that if the trace buffer is exhausted, the checksum will
868 still continue to operate.
869
870 iotrace is enabled
871 Start: 10000000 (buffer start address)
872 Size: 00010000 (buffer size)
873 Offset: 00000120 (current buffer offset)
874 Output: 10000120 (start + offset)
875 Count: 00000018 (number of trace records)
876 CRC32: 9526fb66 (CRC32 of all trace records)
877
878 - Timestamp Support:
879
880 When CONFIG_TIMESTAMP is selected, the timestamp
881 (date and time) of an image is printed by image
882 commands like bootm or iminfo. This option is
883 automatically enabled when you select CONFIG_CMD_DATE .
884
885 - Partition Labels (disklabels) Supported:
886 Zero or more of the following:
887 CONFIG_MAC_PARTITION Apple's MacOS partition table.
888 CONFIG_ISO_PARTITION ISO partition table, used on CDROM etc.
889 CONFIG_EFI_PARTITION GPT partition table, common when EFI is the
890 bootloader. Note 2TB partition limit; see
891 disk/part_efi.c
892 CONFIG_MTD_PARTITIONS Memory Technology Device partition table.
893
894 If IDE or SCSI support is enabled (CONFIG_IDE or
895 CONFIG_SCSI) you must configure support for at
896 least one non-MTD partition type as well.
897
898 - IDE Reset method:
899 CONFIG_IDE_RESET_ROUTINE - this is defined in several
900 board configurations files but used nowhere!
901
902 CONFIG_IDE_RESET - is this is defined, IDE Reset will
903 be performed by calling the function
904 ide_set_reset(int reset)
905 which has to be defined in a board specific file
906
907 - ATAPI Support:
908 CONFIG_ATAPI
909
910 Set this to enable ATAPI support.
911
912 - LBA48 Support
913 CONFIG_LBA48
914
915 Set this to enable support for disks larger than 137GB
916 Also look at CONFIG_SYS_64BIT_LBA.
917 Whithout these , LBA48 support uses 32bit variables and will 'only'
918 support disks up to 2.1TB.
919
920 CONFIG_SYS_64BIT_LBA:
921 When enabled, makes the IDE subsystem use 64bit sector addresses.
922 Default is 32bit.
923
924 - SCSI Support:
925 CONFIG_SYS_SCSI_MAX_LUN [8], CONFIG_SYS_SCSI_MAX_SCSI_ID [7] and
926 CONFIG_SYS_SCSI_MAX_DEVICE [CONFIG_SYS_SCSI_MAX_SCSI_ID *
927 CONFIG_SYS_SCSI_MAX_LUN] can be adjusted to define the
928 maximum numbers of LUNs, SCSI ID's and target
929 devices.
930
931 The environment variable 'scsidevs' is set to the number of
932 SCSI devices found during the last scan.
933
934 - NETWORK Support (PCI):
935 CONFIG_E1000
936 Support for Intel 8254x/8257x gigabit chips.
937
938 CONFIG_E1000_SPI
939 Utility code for direct access to the SPI bus on Intel 8257x.
940 This does not do anything useful unless you set at least one
941 of CONFIG_CMD_E1000 or CONFIG_E1000_SPI_GENERIC.
942
943 CONFIG_E1000_SPI_GENERIC
944 Allow generic access to the SPI bus on the Intel 8257x, for
945 example with the "sspi" command.
946
947 CONFIG_EEPRO100
948 Support for Intel 82557/82559/82559ER chips.
949 Optional CONFIG_EEPRO100_SROM_WRITE enables EEPROM
950 write routine for first time initialisation.
951
952 CONFIG_TULIP
953 Support for Digital 2114x chips.
954 Optional CONFIG_TULIP_SELECT_MEDIA for board specific
955 modem chip initialisation (KS8761/QS6611).
956
957 CONFIG_NATSEMI
958 Support for National dp83815 chips.
959
960 CONFIG_NS8382X
961 Support for National dp8382[01] gigabit chips.
962
963 - NETWORK Support (other):
964
965 CONFIG_DRIVER_AT91EMAC
966 Support for AT91RM9200 EMAC.
967
968 CONFIG_RMII
969 Define this to use reduced MII inteface
970
971 CONFIG_DRIVER_AT91EMAC_QUIET
972 If this defined, the driver is quiet.
973 The driver doen't show link status messages.
974
975 CONFIG_CALXEDA_XGMAC
976 Support for the Calxeda XGMAC device
977
978 CONFIG_LAN91C96
979 Support for SMSC's LAN91C96 chips.
980
981 CONFIG_LAN91C96_USE_32_BIT
982 Define this to enable 32 bit addressing
983
984 CONFIG_SMC91111
985 Support for SMSC's LAN91C111 chip
986
987 CONFIG_SMC91111_BASE
988 Define this to hold the physical address
989 of the device (I/O space)
990
991 CONFIG_SMC_USE_32_BIT
992 Define this if data bus is 32 bits
993
994 CONFIG_SMC_USE_IOFUNCS
995 Define this to use i/o functions instead of macros
996 (some hardware wont work with macros)
997
998 CONFIG_DRIVER_TI_EMAC
999 Support for davinci emac
1000
1001 CONFIG_SYS_DAVINCI_EMAC_PHY_COUNT
1002 Define this if you have more then 3 PHYs.
1003
1004 CONFIG_FTGMAC100
1005 Support for Faraday's FTGMAC100 Gigabit SoC Ethernet
1006
1007 CONFIG_FTGMAC100_EGIGA
1008 Define this to use GE link update with gigabit PHY.
1009 Define this if FTGMAC100 is connected to gigabit PHY.
1010 If your system has 10/100 PHY only, it might not occur
1011 wrong behavior. Because PHY usually return timeout or
1012 useless data when polling gigabit status and gigabit
1013 control registers. This behavior won't affect the
1014 correctnessof 10/100 link speed update.
1015
1016 CONFIG_SH_ETHER
1017 Support for Renesas on-chip Ethernet controller
1018
1019 CONFIG_SH_ETHER_USE_PORT
1020 Define the number of ports to be used
1021
1022 CONFIG_SH_ETHER_PHY_ADDR
1023 Define the ETH PHY's address
1024
1025 CONFIG_SH_ETHER_CACHE_WRITEBACK
1026 If this option is set, the driver enables cache flush.
1027
1028 - PWM Support:
1029 CONFIG_PWM_IMX
1030 Support for PWM module on the imx6.
1031
1032 - TPM Support:
1033 CONFIG_TPM
1034 Support TPM devices.
1035
1036 CONFIG_TPM_TIS_INFINEON
1037 Support for Infineon i2c bus TPM devices. Only one device
1038 per system is supported at this time.
1039
1040 CONFIG_TPM_TIS_I2C_BURST_LIMITATION
1041 Define the burst count bytes upper limit
1042
1043 CONFIG_TPM_ST33ZP24
1044 Support for STMicroelectronics TPM devices. Requires DM_TPM support.
1045
1046 CONFIG_TPM_ST33ZP24_I2C
1047 Support for STMicroelectronics ST33ZP24 I2C devices.
1048 Requires TPM_ST33ZP24 and I2C.
1049
1050 CONFIG_TPM_ST33ZP24_SPI
1051 Support for STMicroelectronics ST33ZP24 SPI devices.
1052 Requires TPM_ST33ZP24 and SPI.
1053
1054 CONFIG_TPM_ATMEL_TWI
1055 Support for Atmel TWI TPM device. Requires I2C support.
1056
1057 CONFIG_TPM_TIS_LPC
1058 Support for generic parallel port TPM devices. Only one device
1059 per system is supported at this time.
1060
1061 CONFIG_TPM_TIS_BASE_ADDRESS
1062 Base address where the generic TPM device is mapped
1063 to. Contemporary x86 systems usually map it at
1064 0xfed40000.
1065
1066 CONFIG_TPM
1067 Define this to enable the TPM support library which provides
1068 functional interfaces to some TPM commands.
1069 Requires support for a TPM device.
1070
1071 CONFIG_TPM_AUTH_SESSIONS
1072 Define this to enable authorized functions in the TPM library.
1073 Requires CONFIG_TPM and CONFIG_SHA1.
1074
1075 - USB Support:
1076 At the moment only the UHCI host controller is
1077 supported (PIP405, MIP405); define
1078 CONFIG_USB_UHCI to enable it.
1079 define CONFIG_USB_KEYBOARD to enable the USB Keyboard
1080 and define CONFIG_USB_STORAGE to enable the USB
1081 storage devices.
1082 Note:
1083 Supported are USB Keyboards and USB Floppy drives
1084 (TEAC FD-05PUB).
1085
1086 CONFIG_USB_EHCI_TXFIFO_THRESH enables setting of the
1087 txfilltuning field in the EHCI controller on reset.
1088
1089 CONFIG_USB_DWC2_REG_ADDR the physical CPU address of the DWC2
1090 HW module registers.
1091
1092 - USB Device:
1093 Define the below if you wish to use the USB console.
1094 Once firmware is rebuilt from a serial console issue the
1095 command "setenv stdin usbtty; setenv stdout usbtty" and
1096 attach your USB cable. The Unix command "dmesg" should print
1097 it has found a new device. The environment variable usbtty
1098 can be set to gserial or cdc_acm to enable your device to
1099 appear to a USB host as a Linux gserial device or a
1100 Common Device Class Abstract Control Model serial device.
1101 If you select usbtty = gserial you should be able to enumerate
1102 a Linux host by
1103 # modprobe usbserial vendor=0xVendorID product=0xProductID
1104 else if using cdc_acm, simply setting the environment
1105 variable usbtty to be cdc_acm should suffice. The following
1106 might be defined in YourBoardName.h
1107
1108 CONFIG_USB_DEVICE
1109 Define this to build a UDC device
1110
1111 CONFIG_USB_TTY
1112 Define this to have a tty type of device available to
1113 talk to the UDC device
1114
1115 CONFIG_USBD_HS
1116 Define this to enable the high speed support for usb
1117 device and usbtty. If this feature is enabled, a routine
1118 int is_usbd_high_speed(void)
1119 also needs to be defined by the driver to dynamically poll
1120 whether the enumeration has succeded at high speed or full
1121 speed.
1122
1123 CONFIG_SYS_CONSOLE_IS_IN_ENV
1124 Define this if you want stdin, stdout &/or stderr to
1125 be set to usbtty.
1126
1127 If you have a USB-IF assigned VendorID then you may wish to
1128 define your own vendor specific values either in BoardName.h
1129 or directly in usbd_vendor_info.h. If you don't define
1130 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME,
1131 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot
1132 should pretend to be a Linux device to it's target host.
1133
1134 CONFIG_USBD_MANUFACTURER
1135 Define this string as the name of your company for
1136 - CONFIG_USBD_MANUFACTURER "my company"
1137
1138 CONFIG_USBD_PRODUCT_NAME
1139 Define this string as the name of your product
1140 - CONFIG_USBD_PRODUCT_NAME "acme usb device"
1141
1142 CONFIG_USBD_VENDORID
1143 Define this as your assigned Vendor ID from the USB
1144 Implementors Forum. This *must* be a genuine Vendor ID
1145 to avoid polluting the USB namespace.
1146 - CONFIG_USBD_VENDORID 0xFFFF
1147
1148 CONFIG_USBD_PRODUCTID
1149 Define this as the unique Product ID
1150 for your device
1151 - CONFIG_USBD_PRODUCTID 0xFFFF
1152
1153 - ULPI Layer Support:
1154 The ULPI (UTMI Low Pin (count) Interface) PHYs are supported via
1155 the generic ULPI layer. The generic layer accesses the ULPI PHY
1156 via the platform viewport, so you need both the genric layer and
1157 the viewport enabled. Currently only Chipidea/ARC based
1158 viewport is supported.
1159 To enable the ULPI layer support, define CONFIG_USB_ULPI and
1160 CONFIG_USB_ULPI_VIEWPORT in your board configuration file.
1161 If your ULPI phy needs a different reference clock than the
1162 standard 24 MHz then you have to define CONFIG_ULPI_REF_CLK to
1163 the appropriate value in Hz.
1164
1165 - MMC Support:
1166 The MMC controller on the Intel PXA is supported. To
1167 enable this define CONFIG_MMC. The MMC can be
1168 accessed from the boot prompt by mapping the device
1169 to physical memory similar to flash. Command line is
1170 enabled with CONFIG_CMD_MMC. The MMC driver also works with
1171 the FAT fs. This is enabled with CONFIG_CMD_FAT.
1172
1173 CONFIG_SH_MMCIF
1174 Support for Renesas on-chip MMCIF controller
1175
1176 CONFIG_SH_MMCIF_ADDR
1177 Define the base address of MMCIF registers
1178
1179 CONFIG_SH_MMCIF_CLK
1180 Define the clock frequency for MMCIF
1181
1182 CONFIG_SUPPORT_EMMC_BOOT
1183 Enable some additional features of the eMMC boot partitions.
1184
1185 CONFIG_SUPPORT_EMMC_RPMB
1186 Enable the commands for reading, writing and programming the
1187 key for the Replay Protection Memory Block partition in eMMC.
1188
1189 - USB Device Firmware Update (DFU) class support:
1190 CONFIG_DFU_OVER_USB
1191 This enables the USB portion of the DFU USB class
1192
1193 CONFIG_DFU_MMC
1194 This enables support for exposing (e)MMC devices via DFU.
1195
1196 CONFIG_DFU_NAND
1197 This enables support for exposing NAND devices via DFU.
1198
1199 CONFIG_DFU_RAM
1200 This enables support for exposing RAM via DFU.
1201 Note: DFU spec refer to non-volatile memory usage, but
1202 allow usages beyond the scope of spec - here RAM usage,
1203 one that would help mostly the developer.
1204
1205 CONFIG_SYS_DFU_DATA_BUF_SIZE
1206 Dfu transfer uses a buffer before writing data to the
1207 raw storage device. Make the size (in bytes) of this buffer
1208 configurable. The size of this buffer is also configurable
1209 through the "dfu_bufsiz" environment variable.
1210
1211 CONFIG_SYS_DFU_MAX_FILE_SIZE
1212 When updating files rather than the raw storage device,
1213 we use a static buffer to copy the file into and then write
1214 the buffer once we've been given the whole file. Define
1215 this to the maximum filesize (in bytes) for the buffer.
1216 Default is 4 MiB if undefined.
1217
1218 DFU_DEFAULT_POLL_TIMEOUT
1219 Poll timeout [ms], is the timeout a device can send to the
1220 host. The host must wait for this timeout before sending
1221 a subsequent DFU_GET_STATUS request to the device.
1222
1223 DFU_MANIFEST_POLL_TIMEOUT
1224 Poll timeout [ms], which the device sends to the host when
1225 entering dfuMANIFEST state. Host waits this timeout, before
1226 sending again an USB request to the device.
1227
1228 - Journaling Flash filesystem support:
1229 CONFIG_JFFS2_NAND
1230 Define these for a default partition on a NAND device
1231
1232 CONFIG_SYS_JFFS2_FIRST_SECTOR,
1233 CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS
1234 Define these for a default partition on a NOR device
1235
1236 - Keyboard Support:
1237 See Kconfig help for available keyboard drivers.
1238
1239 CONFIG_KEYBOARD
1240
1241 Define this to enable a custom keyboard support.
1242 This simply calls drv_keyboard_init() which must be
1243 defined in your board-specific files. This option is deprecated
1244 and is only used by novena. For new boards, use driver model
1245 instead.
1246
1247 - Video support:
1248 CONFIG_FSL_DIU_FB
1249 Enable the Freescale DIU video driver. Reference boards for
1250 SOCs that have a DIU should define this macro to enable DIU
1251 support, and should also define these other macros:
1252
1253 CONFIG_SYS_DIU_ADDR
1254 CONFIG_VIDEO
1255 CONFIG_CFB_CONSOLE
1256 CONFIG_VIDEO_SW_CURSOR
1257 CONFIG_VGA_AS_SINGLE_DEVICE
1258 CONFIG_VIDEO_LOGO
1259 CONFIG_VIDEO_BMP_LOGO
1260
1261 The DIU driver will look for the 'video-mode' environment
1262 variable, and if defined, enable the DIU as a console during
1263 boot. See the documentation file doc/README.video for a
1264 description of this variable.
1265
1266 - LCD Support: CONFIG_LCD
1267
1268 Define this to enable LCD support (for output to LCD
1269 display); also select one of the supported displays
1270 by defining one of these:
1271
1272 CONFIG_ATMEL_LCD:
1273
1274 HITACHI TX09D70VM1CCA, 3.5", 240x320.
1275
1276 CONFIG_NEC_NL6448AC33:
1277
1278 NEC NL6448AC33-18. Active, color, single scan.
1279
1280 CONFIG_NEC_NL6448BC20
1281
1282 NEC NL6448BC20-08. 6.5", 640x480.
1283 Active, color, single scan.
1284
1285 CONFIG_NEC_NL6448BC33_54
1286
1287 NEC NL6448BC33-54. 10.4", 640x480.
1288 Active, color, single scan.
1289
1290 CONFIG_SHARP_16x9
1291
1292 Sharp 320x240. Active, color, single scan.
1293 It isn't 16x9, and I am not sure what it is.
1294
1295 CONFIG_SHARP_LQ64D341
1296
1297 Sharp LQ64D341 display, 640x480.
1298 Active, color, single scan.
1299
1300 CONFIG_HLD1045
1301
1302 HLD1045 display, 640x480.
1303 Active, color, single scan.
1304
1305 CONFIG_OPTREX_BW
1306
1307 Optrex CBL50840-2 NF-FW 99 22 M5
1308 or
1309 Hitachi LMG6912RPFC-00T
1310 or
1311 Hitachi SP14Q002
1312
1313 320x240. Black & white.
1314
1315 CONFIG_LCD_ALIGNMENT
1316
1317 Normally the LCD is page-aligned (typically 4KB). If this is
1318 defined then the LCD will be aligned to this value instead.
1319 For ARM it is sometimes useful to use MMU_SECTION_SIZE
1320 here, since it is cheaper to change data cache settings on
1321 a per-section basis.
1322
1323
1324 CONFIG_LCD_ROTATION
1325
1326 Sometimes, for example if the display is mounted in portrait
1327 mode or even if it's mounted landscape but rotated by 180degree,
1328 we need to rotate our content of the display relative to the
1329 framebuffer, so that user can read the messages which are
1330 printed out.
1331 Once CONFIG_LCD_ROTATION is defined, the lcd_console will be
1332 initialized with a given rotation from "vl_rot" out of
1333 "vidinfo_t" which is provided by the board specific code.
1334 The value for vl_rot is coded as following (matching to
1335 fbcon=rotate:<n> linux-kernel commandline):
1336 0 = no rotation respectively 0 degree
1337 1 = 90 degree rotation
1338 2 = 180 degree rotation
1339 3 = 270 degree rotation
1340
1341 If CONFIG_LCD_ROTATION is not defined, the console will be
1342 initialized with 0degree rotation.
1343
1344 CONFIG_LCD_BMP_RLE8
1345
1346 Support drawing of RLE8-compressed bitmaps on the LCD.
1347
1348 CONFIG_I2C_EDID
1349
1350 Enables an 'i2c edid' command which can read EDID
1351 information over I2C from an attached LCD display.
1352
1353 - Splash Screen Support: CONFIG_SPLASH_SCREEN
1354
1355 If this option is set, the environment is checked for
1356 a variable "splashimage". If found, the usual display
1357 of logo, copyright and system information on the LCD
1358 is suppressed and the BMP image at the address
1359 specified in "splashimage" is loaded instead. The
1360 console is redirected to the "nulldev", too. This
1361 allows for a "silent" boot where a splash screen is
1362 loaded very quickly after power-on.
1363
1364 CONFIG_SPLASHIMAGE_GUARD
1365
1366 If this option is set, then U-Boot will prevent the environment
1367 variable "splashimage" from being set to a problematic address
1368 (see doc/README.displaying-bmps).
1369 This option is useful for targets where, due to alignment
1370 restrictions, an improperly aligned BMP image will cause a data
1371 abort. If you think you will not have problems with unaligned
1372 accesses (for example because your toolchain prevents them)
1373 there is no need to set this option.
1374
1375 CONFIG_SPLASH_SCREEN_ALIGN
1376
1377 If this option is set the splash image can be freely positioned
1378 on the screen. Environment variable "splashpos" specifies the
1379 position as "x,y". If a positive number is given it is used as
1380 number of pixel from left/top. If a negative number is given it
1381 is used as number of pixel from right/bottom. You can also
1382 specify 'm' for centering the image.
1383
1384 Example:
1385 setenv splashpos m,m
1386 => image at center of screen
1387
1388 setenv splashpos 30,20
1389 => image at x = 30 and y = 20
1390
1391 setenv splashpos -10,m
1392 => vertically centered image
1393 at x = dspWidth - bmpWidth - 9
1394
1395 - Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP
1396
1397 If this option is set, additionally to standard BMP
1398 images, gzipped BMP images can be displayed via the
1399 splashscreen support or the bmp command.
1400
1401 - Run length encoded BMP image (RLE8) support: CONFIG_VIDEO_BMP_RLE8
1402
1403 If this option is set, 8-bit RLE compressed BMP images
1404 can be displayed via the splashscreen support or the
1405 bmp command.
1406
1407 - Compression support:
1408 CONFIG_GZIP
1409
1410 Enabled by default to support gzip compressed images.
1411
1412 CONFIG_BZIP2
1413
1414 If this option is set, support for bzip2 compressed
1415 images is included. If not, only uncompressed and gzip
1416 compressed images are supported.
1417
1418 NOTE: the bzip2 algorithm requires a lot of RAM, so
1419 the malloc area (as defined by CONFIG_SYS_MALLOC_LEN) should
1420 be at least 4MB.
1421
1422 - MII/PHY support:
1423 CONFIG_PHY_ADDR
1424
1425 The address of PHY on MII bus.
1426
1427 CONFIG_PHY_CLOCK_FREQ (ppc4xx)
1428
1429 The clock frequency of the MII bus
1430
1431 CONFIG_PHY_RESET_DELAY
1432
1433 Some PHY like Intel LXT971A need extra delay after
1434 reset before any MII register access is possible.
1435 For such PHY, set this option to the usec delay
1436 required. (minimum 300usec for LXT971A)
1437
1438 CONFIG_PHY_CMD_DELAY (ppc4xx)
1439
1440 Some PHY like Intel LXT971A need extra delay after
1441 command issued before MII status register can be read
1442
1443 - IP address:
1444 CONFIG_IPADDR
1445
1446 Define a default value for the IP address to use for
1447 the default Ethernet interface, in case this is not
1448 determined through e.g. bootp.
1449 (Environment variable "ipaddr")
1450
1451 - Server IP address:
1452 CONFIG_SERVERIP
1453
1454 Defines a default value for the IP address of a TFTP
1455 server to contact when using the "tftboot" command.
1456 (Environment variable "serverip")
1457
1458 CONFIG_KEEP_SERVERADDR
1459
1460 Keeps the server's MAC address, in the env 'serveraddr'
1461 for passing to bootargs (like Linux's netconsole option)
1462
1463 - Gateway IP address:
1464 CONFIG_GATEWAYIP
1465
1466 Defines a default value for the IP address of the
1467 default router where packets to other networks are
1468 sent to.
1469 (Environment variable "gatewayip")
1470
1471 - Subnet mask:
1472 CONFIG_NETMASK
1473
1474 Defines a default value for the subnet mask (or
1475 routing prefix) which is used to determine if an IP
1476 address belongs to the local subnet or needs to be
1477 forwarded through a router.
1478 (Environment variable "netmask")
1479
1480 - Multicast TFTP Mode:
1481 CONFIG_MCAST_TFTP
1482
1483 Defines whether you want to support multicast TFTP as per
1484 rfc-2090; for example to work with atftp. Lets lots of targets
1485 tftp down the same boot image concurrently. Note: the Ethernet
1486 driver in use must provide a function: mcast() to join/leave a
1487 multicast group.
1488
1489 - BOOTP Recovery Mode:
1490 CONFIG_BOOTP_RANDOM_DELAY
1491
1492 If you have many targets in a network that try to
1493 boot using BOOTP, you may want to avoid that all
1494 systems send out BOOTP requests at precisely the same
1495 moment (which would happen for instance at recovery
1496 from a power failure, when all systems will try to
1497 boot, thus flooding the BOOTP server. Defining
1498 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
1499 inserted before sending out BOOTP requests. The
1500 following delays are inserted then:
1501
1502 1st BOOTP request: delay 0 ... 1 sec
1503 2nd BOOTP request: delay 0 ... 2 sec
1504 3rd BOOTP request: delay 0 ... 4 sec
1505 4th and following
1506 BOOTP requests: delay 0 ... 8 sec
1507
1508 CONFIG_BOOTP_ID_CACHE_SIZE
1509
1510 BOOTP packets are uniquely identified using a 32-bit ID. The
1511 server will copy the ID from client requests to responses and
1512 U-Boot will use this to determine if it is the destination of
1513 an incoming response. Some servers will check that addresses
1514 aren't in use before handing them out (usually using an ARP
1515 ping) and therefore take up to a few hundred milliseconds to
1516 respond. Network congestion may also influence the time it
1517 takes for a response to make it back to the client. If that
1518 time is too long, U-Boot will retransmit requests. In order
1519 to allow earlier responses to still be accepted after these
1520 retransmissions, U-Boot's BOOTP client keeps a small cache of
1521 IDs. The CONFIG_BOOTP_ID_CACHE_SIZE controls the size of this
1522 cache. The default is to keep IDs for up to four outstanding
1523 requests. Increasing this will allow U-Boot to accept offers
1524 from a BOOTP client in networks with unusually high latency.
1525
1526 - DHCP Advanced Options:
1527 You can fine tune the DHCP functionality by defining
1528 CONFIG_BOOTP_* symbols:
1529
1530 CONFIG_BOOTP_NISDOMAIN
1531 CONFIG_BOOTP_BOOTFILESIZE
1532 CONFIG_BOOTP_SEND_HOSTNAME
1533 CONFIG_BOOTP_NTPSERVER
1534 CONFIG_BOOTP_TIMEOFFSET
1535 CONFIG_BOOTP_VENDOREX
1536 CONFIG_BOOTP_MAY_FAIL
1537
1538 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip
1539 environment variable, not the BOOTP server.
1540
1541 CONFIG_BOOTP_MAY_FAIL - If the DHCP server is not found
1542 after the configured retry count, the call will fail
1543 instead of starting over. This can be used to fail over
1544 to Link-local IP address configuration if the DHCP server
1545 is not available.
1546
1547 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable
1548 to do a dynamic update of a DNS server. To do this, they
1549 need the hostname of the DHCP requester.
1550 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content
1551 of the "hostname" environment variable is passed as
1552 option 12 to the DHCP server.
1553
1554 CONFIG_BOOTP_DHCP_REQUEST_DELAY
1555
1556 A 32bit value in microseconds for a delay between
1557 receiving a "DHCP Offer" and sending the "DHCP Request".
1558 This fixes a problem with certain DHCP servers that don't
1559 respond 100% of the time to a "DHCP request". E.g. On an
1560 AT91RM9200 processor running at 180MHz, this delay needed
1561 to be *at least* 15,000 usec before a Windows Server 2003
1562 DHCP server would reply 100% of the time. I recommend at
1563 least 50,000 usec to be safe. The alternative is to hope
1564 that one of the retries will be successful but note that
1565 the DHCP timeout and retry process takes a longer than
1566 this delay.
1567
1568 - Link-local IP address negotiation:
1569 Negotiate with other link-local clients on the local network
1570 for an address that doesn't require explicit configuration.
1571 This is especially useful if a DHCP server cannot be guaranteed
1572 to exist in all environments that the device must operate.
1573
1574 See doc/README.link-local for more information.
1575
1576 - MAC address from environment variables
1577
1578 FDT_SEQ_MACADDR_FROM_ENV
1579
1580 Fix-up device tree with MAC addresses fetched sequentially from
1581 environment variables. This config work on assumption that
1582 non-usable ethernet node of device-tree are either not present
1583 or their status has been marked as "disabled".
1584
1585 - CDP Options:
1586 CONFIG_CDP_DEVICE_ID
1587
1588 The device id used in CDP trigger frames.
1589
1590 CONFIG_CDP_DEVICE_ID_PREFIX
1591
1592 A two character string which is prefixed to the MAC address
1593 of the device.
1594
1595 CONFIG_CDP_PORT_ID
1596
1597 A printf format string which contains the ascii name of
1598 the port. Normally is set to "eth%d" which sets
1599 eth0 for the first Ethernet, eth1 for the second etc.
1600
1601 CONFIG_CDP_CAPABILITIES
1602
1603 A 32bit integer which indicates the device capabilities;
1604 0x00000010 for a normal host which does not forwards.
1605
1606 CONFIG_CDP_VERSION
1607
1608 An ascii string containing the version of the software.
1609
1610 CONFIG_CDP_PLATFORM
1611
1612 An ascii string containing the name of the platform.
1613
1614 CONFIG_CDP_TRIGGER
1615
1616 A 32bit integer sent on the trigger.
1617
1618 CONFIG_CDP_POWER_CONSUMPTION
1619
1620 A 16bit integer containing the power consumption of the
1621 device in .1 of milliwatts.
1622
1623 CONFIG_CDP_APPLIANCE_VLAN_TYPE
1624
1625 A byte containing the id of the VLAN.
1626
1627 - Status LED: CONFIG_LED_STATUS
1628
1629 Several configurations allow to display the current
1630 status using a LED. For instance, the LED will blink
1631 fast while running U-Boot code, stop blinking as
1632 soon as a reply to a BOOTP request was received, and
1633 start blinking slow once the Linux kernel is running
1634 (supported by a status LED driver in the Linux
1635 kernel). Defining CONFIG_LED_STATUS enables this
1636 feature in U-Boot.
1637
1638 Additional options:
1639
1640 CONFIG_LED_STATUS_GPIO
1641 The status LED can be connected to a GPIO pin.
1642 In such cases, the gpio_led driver can be used as a
1643 status LED backend implementation. Define CONFIG_LED_STATUS_GPIO
1644 to include the gpio_led driver in the U-Boot binary.
1645
1646 CONFIG_GPIO_LED_INVERTED_TABLE
1647 Some GPIO connected LEDs may have inverted polarity in which
1648 case the GPIO high value corresponds to LED off state and
1649 GPIO low value corresponds to LED on state.
1650 In such cases CONFIG_GPIO_LED_INVERTED_TABLE may be defined
1651 with a list of GPIO LEDs that have inverted polarity.
1652
1653 - I2C Support: CONFIG_SYS_I2C
1654
1655 This enable the NEW i2c subsystem, and will allow you to use
1656 i2c commands at the u-boot command line (as long as you set
1657 CONFIG_CMD_I2C in CONFIG_COMMANDS) and communicate with i2c
1658 based realtime clock chips or other i2c devices. See
1659 common/cmd_i2c.c for a description of the command line
1660 interface.
1661
1662 ported i2c driver to the new framework:
1663 - drivers/i2c/soft_i2c.c:
1664 - activate first bus with CONFIG_SYS_I2C_SOFT define
1665 CONFIG_SYS_I2C_SOFT_SPEED and CONFIG_SYS_I2C_SOFT_SLAVE
1666 for defining speed and slave address
1667 - activate second bus with I2C_SOFT_DECLARATIONS2 define
1668 CONFIG_SYS_I2C_SOFT_SPEED_2 and CONFIG_SYS_I2C_SOFT_SLAVE_2
1669 for defining speed and slave address
1670 - activate third bus with I2C_SOFT_DECLARATIONS3 define
1671 CONFIG_SYS_I2C_SOFT_SPEED_3 and CONFIG_SYS_I2C_SOFT_SLAVE_3
1672 for defining speed and slave address
1673 - activate fourth bus with I2C_SOFT_DECLARATIONS4 define
1674 CONFIG_SYS_I2C_SOFT_SPEED_4 and CONFIG_SYS_I2C_SOFT_SLAVE_4
1675 for defining speed and slave address
1676
1677 - drivers/i2c/fsl_i2c.c:
1678 - activate i2c driver with CONFIG_SYS_I2C_FSL
1679 define CONFIG_SYS_FSL_I2C_OFFSET for setting the register
1680 offset CONFIG_SYS_FSL_I2C_SPEED for the i2c speed and
1681 CONFIG_SYS_FSL_I2C_SLAVE for the slave addr of the first
1682 bus.
1683 - If your board supports a second fsl i2c bus, define
1684 CONFIG_SYS_FSL_I2C2_OFFSET for the register offset
1685 CONFIG_SYS_FSL_I2C2_SPEED for the speed and
1686 CONFIG_SYS_FSL_I2C2_SLAVE for the slave address of the
1687 second bus.
1688
1689 - drivers/i2c/tegra_i2c.c:
1690 - activate this driver with CONFIG_SYS_I2C_TEGRA
1691 - This driver adds 4 i2c buses with a fix speed from
1692 100000 and the slave addr 0!
1693
1694 - drivers/i2c/ppc4xx_i2c.c
1695 - activate this driver with CONFIG_SYS_I2C_PPC4XX
1696 - CONFIG_SYS_I2C_PPC4XX_CH0 activate hardware channel 0
1697 - CONFIG_SYS_I2C_PPC4XX_CH1 activate hardware channel 1
1698
1699 - drivers/i2c/i2c_mxc.c
1700 - activate this driver with CONFIG_SYS_I2C_MXC
1701 - enable bus 1 with CONFIG_SYS_I2C_MXC_I2C1
1702 - enable bus 2 with CONFIG_SYS_I2C_MXC_I2C2
1703 - enable bus 3 with CONFIG_SYS_I2C_MXC_I2C3
1704 - enable bus 4 with CONFIG_SYS_I2C_MXC_I2C4
1705 - define speed for bus 1 with CONFIG_SYS_MXC_I2C1_SPEED
1706 - define slave for bus 1 with CONFIG_SYS_MXC_I2C1_SLAVE
1707 - define speed for bus 2 with CONFIG_SYS_MXC_I2C2_SPEED
1708 - define slave for bus 2 with CONFIG_SYS_MXC_I2C2_SLAVE
1709 - define speed for bus 3 with CONFIG_SYS_MXC_I2C3_SPEED
1710 - define slave for bus 3 with CONFIG_SYS_MXC_I2C3_SLAVE
1711 - define speed for bus 4 with CONFIG_SYS_MXC_I2C4_SPEED
1712 - define slave for bus 4 with CONFIG_SYS_MXC_I2C4_SLAVE
1713 If those defines are not set, default value is 100000
1714 for speed, and 0 for slave.
1715
1716 - drivers/i2c/rcar_i2c.c:
1717 - activate this driver with CONFIG_SYS_I2C_RCAR
1718 - This driver adds 4 i2c buses
1719
1720 - CONFIG_SYS_RCAR_I2C0_BASE for setting the register channel 0
1721 - CONFIG_SYS_RCAR_I2C0_SPEED for for the speed channel 0
1722 - CONFIG_SYS_RCAR_I2C1_BASE for setting the register channel 1
1723 - CONFIG_SYS_RCAR_I2C1_SPEED for for the speed channel 1
1724 - CONFIG_SYS_RCAR_I2C2_BASE for setting the register channel 2
1725 - CONFIG_SYS_RCAR_I2C2_SPEED for for the speed channel 2
1726 - CONFIG_SYS_RCAR_I2C3_BASE for setting the register channel 3
1727 - CONFIG_SYS_RCAR_I2C3_SPEED for for the speed channel 3
1728 - CONFIF_SYS_RCAR_I2C_NUM_CONTROLLERS for number of i2c buses
1729
1730 - drivers/i2c/sh_i2c.c:
1731 - activate this driver with CONFIG_SYS_I2C_SH
1732 - This driver adds from 2 to 5 i2c buses
1733
1734 - CONFIG_SYS_I2C_SH_BASE0 for setting the register channel 0
1735 - CONFIG_SYS_I2C_SH_SPEED0 for for the speed channel 0
1736 - CONFIG_SYS_I2C_SH_BASE1 for setting the register channel 1
1737 - CONFIG_SYS_I2C_SH_SPEED1 for for the speed channel 1
1738 - CONFIG_SYS_I2C_SH_BASE2 for setting the register channel 2
1739 - CONFIG_SYS_I2C_SH_SPEED2 for for the speed channel 2
1740 - CONFIG_SYS_I2C_SH_BASE3 for setting the register channel 3
1741 - CONFIG_SYS_I2C_SH_SPEED3 for for the speed channel 3
1742 - CONFIG_SYS_I2C_SH_BASE4 for setting the register channel 4
1743 - CONFIG_SYS_I2C_SH_SPEED4 for for the speed channel 4
1744 - CONFIG_SYS_I2C_SH_NUM_CONTROLLERS for number of i2c buses
1745
1746 - drivers/i2c/omap24xx_i2c.c
1747 - activate this driver with CONFIG_SYS_I2C_OMAP24XX
1748 - CONFIG_SYS_OMAP24_I2C_SPEED speed channel 0
1749 - CONFIG_SYS_OMAP24_I2C_SLAVE slave addr channel 0
1750 - CONFIG_SYS_OMAP24_I2C_SPEED1 speed channel 1
1751 - CONFIG_SYS_OMAP24_I2C_SLAVE1 slave addr channel 1
1752 - CONFIG_SYS_OMAP24_I2C_SPEED2 speed channel 2
1753 - CONFIG_SYS_OMAP24_I2C_SLAVE2 slave addr channel 2
1754 - CONFIG_SYS_OMAP24_I2C_SPEED3 speed channel 3
1755 - CONFIG_SYS_OMAP24_I2C_SLAVE3 slave addr channel 3
1756 - CONFIG_SYS_OMAP24_I2C_SPEED4 speed channel 4
1757 - CONFIG_SYS_OMAP24_I2C_SLAVE4 slave addr channel 4
1758
1759 - drivers/i2c/zynq_i2c.c
1760 - activate this driver with CONFIG_SYS_I2C_ZYNQ
1761 - set CONFIG_SYS_I2C_ZYNQ_SPEED for speed setting
1762 - set CONFIG_SYS_I2C_ZYNQ_SLAVE for slave addr
1763
1764 - drivers/i2c/s3c24x0_i2c.c:
1765 - activate this driver with CONFIG_SYS_I2C_S3C24X0
1766 - This driver adds i2c buses (11 for Exynos5250, Exynos5420
1767 9 i2c buses for Exynos4 and 1 for S3C24X0 SoCs from Samsung)
1768 with a fix speed from 100000 and the slave addr 0!
1769
1770 - drivers/i2c/ihs_i2c.c
1771 - activate this driver with CONFIG_SYS_I2C_IHS
1772 - CONFIG_SYS_I2C_IHS_CH0 activate hardware channel 0
1773 - CONFIG_SYS_I2C_IHS_SPEED_0 speed channel 0
1774 - CONFIG_SYS_I2C_IHS_SLAVE_0 slave addr channel 0
1775 - CONFIG_SYS_I2C_IHS_CH1 activate hardware channel 1
1776 - CONFIG_SYS_I2C_IHS_SPEED_1 speed channel 1
1777 - CONFIG_SYS_I2C_IHS_SLAVE_1 slave addr channel 1
1778 - CONFIG_SYS_I2C_IHS_CH2 activate hardware channel 2
1779 - CONFIG_SYS_I2C_IHS_SPEED_2 speed channel 2
1780 - CONFIG_SYS_I2C_IHS_SLAVE_2 slave addr channel 2
1781 - CONFIG_SYS_I2C_IHS_CH3 activate hardware channel 3
1782 - CONFIG_SYS_I2C_IHS_SPEED_3 speed channel 3
1783 - CONFIG_SYS_I2C_IHS_SLAVE_3 slave addr channel 3
1784 - activate dual channel with CONFIG_SYS_I2C_IHS_DUAL
1785 - CONFIG_SYS_I2C_IHS_SPEED_0_1 speed channel 0_1
1786 - CONFIG_SYS_I2C_IHS_SLAVE_0_1 slave addr channel 0_1
1787 - CONFIG_SYS_I2C_IHS_SPEED_1_1 speed channel 1_1
1788 - CONFIG_SYS_I2C_IHS_SLAVE_1_1 slave addr channel 1_1
1789 - CONFIG_SYS_I2C_IHS_SPEED_2_1 speed channel 2_1
1790 - CONFIG_SYS_I2C_IHS_SLAVE_2_1 slave addr channel 2_1
1791 - CONFIG_SYS_I2C_IHS_SPEED_3_1 speed channel 3_1
1792 - CONFIG_SYS_I2C_IHS_SLAVE_3_1 slave addr channel 3_1
1793
1794 additional defines:
1795
1796 CONFIG_SYS_NUM_I2C_BUSES
1797 Hold the number of i2c buses you want to use.
1798
1799 CONFIG_SYS_I2C_DIRECT_BUS
1800 define this, if you don't use i2c muxes on your hardware.
1801 if CONFIG_SYS_I2C_MAX_HOPS is not defined or == 0 you can
1802 omit this define.
1803
1804 CONFIG_SYS_I2C_MAX_HOPS
1805 define how many muxes are maximal consecutively connected
1806 on one i2c bus. If you not use i2c muxes, omit this
1807 define.
1808
1809 CONFIG_SYS_I2C_BUSES
1810 hold a list of buses you want to use, only used if
1811 CONFIG_SYS_I2C_DIRECT_BUS is not defined, for example
1812 a board with CONFIG_SYS_I2C_MAX_HOPS = 1 and
1813 CONFIG_SYS_NUM_I2C_BUSES = 9:
1814
1815 CONFIG_SYS_I2C_BUSES {{0, {I2C_NULL_HOP}}, \
1816 {0, {{I2C_MUX_PCA9547, 0x70, 1}}}, \
1817 {0, {{I2C_MUX_PCA9547, 0x70, 2}}}, \
1818 {0, {{I2C_MUX_PCA9547, 0x70, 3}}}, \
1819 {0, {{I2C_MUX_PCA9547, 0x70, 4}}}, \
1820 {0, {{I2C_MUX_PCA9547, 0x70, 5}}}, \
1821 {1, {I2C_NULL_HOP}}, \
1822 {1, {{I2C_MUX_PCA9544, 0x72, 1}}}, \
1823 {1, {{I2C_MUX_PCA9544, 0x72, 2}}}, \
1824 }
1825
1826 which defines
1827 bus 0 on adapter 0 without a mux
1828 bus 1 on adapter 0 with a PCA9547 on address 0x70 port 1
1829 bus 2 on adapter 0 with a PCA9547 on address 0x70 port 2
1830 bus 3 on adapter 0 with a PCA9547 on address 0x70 port 3
1831 bus 4 on adapter 0 with a PCA9547 on address 0x70 port 4
1832 bus 5 on adapter 0 with a PCA9547 on address 0x70 port 5
1833 bus 6 on adapter 1 without a mux
1834 bus 7 on adapter 1 with a PCA9544 on address 0x72 port 1
1835 bus 8 on adapter 1 with a PCA9544 on address 0x72 port 2
1836
1837 If you do not have i2c muxes on your board, omit this define.
1838
1839 - Legacy I2C Support:
1840 If you use the software i2c interface (CONFIG_SYS_I2C_SOFT)
1841 then the following macros need to be defined (examples are
1842 from include/configs/lwmon.h):
1843
1844 I2C_INIT
1845
1846 (Optional). Any commands necessary to enable the I2C
1847 controller or configure ports.
1848
1849 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
1850
1851 I2C_ACTIVE
1852
1853 The code necessary to make the I2C data line active
1854 (driven). If the data line is open collector, this
1855 define can be null.
1856
1857 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
1858
1859 I2C_TRISTATE
1860
1861 The code necessary to make the I2C data line tri-stated
1862 (inactive). If the data line is open collector, this
1863 define can be null.
1864
1865 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
1866
1867 I2C_READ
1868
1869 Code that returns true if the I2C data line is high,
1870 false if it is low.
1871
1872 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
1873
1874 I2C_SDA(bit)
1875
1876 If <bit> is true, sets the I2C data line high. If it
1877 is false, it clears it (low).
1878
1879 eg: #define I2C_SDA(bit) \
1880 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
1881 else immr->im_cpm.cp_pbdat &= ~PB_SDA
1882
1883 I2C_SCL(bit)
1884
1885 If <bit> is true, sets the I2C clock line high. If it
1886 is false, it clears it (low).
1887
1888 eg: #define I2C_SCL(bit) \
1889 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
1890 else immr->im_cpm.cp_pbdat &= ~PB_SCL
1891
1892 I2C_DELAY
1893
1894 This delay is invoked four times per clock cycle so this
1895 controls the rate of data transfer. The data rate thus
1896 is 1 / (I2C_DELAY * 4). Often defined to be something
1897 like:
1898
1899 #define I2C_DELAY udelay(2)
1900
1901 CONFIG_SOFT_I2C_GPIO_SCL / CONFIG_SOFT_I2C_GPIO_SDA
1902
1903 If your arch supports the generic GPIO framework (asm/gpio.h),
1904 then you may alternatively define the two GPIOs that are to be
1905 used as SCL / SDA. Any of the previous I2C_xxx macros will
1906 have GPIO-based defaults assigned to them as appropriate.
1907
1908 You should define these to the GPIO value as given directly to
1909 the generic GPIO functions.
1910
1911 CONFIG_SYS_I2C_INIT_BOARD
1912
1913 When a board is reset during an i2c bus transfer
1914 chips might think that the current transfer is still
1915 in progress. On some boards it is possible to access
1916 the i2c SCLK line directly, either by using the
1917 processor pin as a GPIO or by having a second pin
1918 connected to the bus. If this option is defined a
1919 custom i2c_init_board() routine in boards/xxx/board.c
1920 is run early in the boot sequence.
1921
1922 CONFIG_I2C_MULTI_BUS
1923
1924 This option allows the use of multiple I2C buses, each of which
1925 must have a controller. At any point in time, only one bus is
1926 active. To switch to a different bus, use the 'i2c dev' command.
1927 Note that bus numbering is zero-based.
1928
1929 CONFIG_SYS_I2C_NOPROBES
1930
1931 This option specifies a list of I2C devices that will be skipped
1932 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS
1933 is set, specify a list of bus-device pairs. Otherwise, specify
1934 a 1D array of device addresses
1935
1936 e.g.
1937 #undef CONFIG_I2C_MULTI_BUS
1938 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68}
1939
1940 will skip addresses 0x50 and 0x68 on a board with one I2C bus
1941
1942 #define CONFIG_I2C_MULTI_BUS
1943 #define CONFIG_SYS_I2C_NOPROBES {{0,0x50},{0,0x68},{1,0x54}}
1944
1945 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1
1946
1947 CONFIG_SYS_SPD_BUS_NUM
1948
1949 If defined, then this indicates the I2C bus number for DDR SPD.
1950 If not defined, then U-Boot assumes that SPD is on I2C bus 0.
1951
1952 CONFIG_SYS_RTC_BUS_NUM
1953
1954 If defined, then this indicates the I2C bus number for the RTC.
1955 If not defined, then U-Boot assumes that RTC is on I2C bus 0.
1956
1957 CONFIG_SOFT_I2C_READ_REPEATED_START
1958
1959 defining this will force the i2c_read() function in
1960 the soft_i2c driver to perform an I2C repeated start
1961 between writing the address pointer and reading the
1962 data. If this define is omitted the default behaviour
1963 of doing a stop-start sequence will be used. Most I2C
1964 devices can use either method, but some require one or
1965 the other.
1966
1967 - SPI Support: CONFIG_SPI
1968
1969 Enables SPI driver (so far only tested with
1970 SPI EEPROM, also an instance works with Crystal A/D and
1971 D/As on the SACSng board)
1972
1973 CONFIG_SOFT_SPI
1974
1975 Enables a software (bit-bang) SPI driver rather than
1976 using hardware support. This is a general purpose
1977 driver that only requires three general I/O port pins
1978 (two outputs, one input) to function. If this is
1979 defined, the board configuration must define several
1980 SPI configuration items (port pins to use, etc). For
1981 an example, see include/configs/sacsng.h.
1982
1983 CONFIG_HARD_SPI
1984
1985 Enables a hardware SPI driver for general-purpose reads
1986 and writes. As with CONFIG_SOFT_SPI, the board configuration
1987 must define a list of chip-select function pointers.
1988 Currently supported on some MPC8xxx processors. For an
1989 example, see include/configs/mpc8349emds.h.
1990
1991 CONFIG_SYS_SPI_MXC_WAIT
1992 Timeout for waiting until spi transfer completed.
1993 default: (CONFIG_SYS_HZ/100) /* 10 ms */
1994
1995 - FPGA Support: CONFIG_FPGA
1996
1997 Enables FPGA subsystem.
1998
1999 CONFIG_FPGA_<vendor>
2000
2001 Enables support for specific chip vendors.
2002 (ALTERA, XILINX)
2003
2004 CONFIG_FPGA_<family>
2005
2006 Enables support for FPGA family.
2007 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX)
2008
2009 CONFIG_FPGA_COUNT
2010
2011 Specify the number of FPGA devices to support.
2012
2013 CONFIG_SYS_FPGA_PROG_FEEDBACK
2014
2015 Enable printing of hash marks during FPGA configuration.
2016
2017 CONFIG_SYS_FPGA_CHECK_BUSY
2018
2019 Enable checks on FPGA configuration interface busy
2020 status by the configuration function. This option
2021 will require a board or device specific function to
2022 be written.
2023
2024 CONFIG_FPGA_DELAY
2025
2026 If defined, a function that provides delays in the FPGA
2027 configuration driver.
2028
2029 CONFIG_SYS_FPGA_CHECK_CTRLC
2030 Allow Control-C to interrupt FPGA configuration
2031
2032 CONFIG_SYS_FPGA_CHECK_ERROR
2033
2034 Check for configuration errors during FPGA bitfile
2035 loading. For example, abort during Virtex II
2036 configuration if the INIT_B line goes low (which
2037 indicated a CRC error).
2038
2039 CONFIG_SYS_FPGA_WAIT_INIT
2040
2041 Maximum time to wait for the INIT_B line to de-assert
2042 after PROB_B has been de-asserted during a Virtex II
2043 FPGA configuration sequence. The default time is 500
2044 ms.
2045
2046 CONFIG_SYS_FPGA_WAIT_BUSY
2047
2048 Maximum time to wait for BUSY to de-assert during
2049 Virtex II FPGA configuration. The default is 5 ms.
2050
2051 CONFIG_SYS_FPGA_WAIT_CONFIG
2052
2053 Time to wait after FPGA configuration. The default is
2054 200 ms.
2055
2056 - Configuration Management:
2057 CONFIG_BUILD_TARGET
2058
2059 Some SoCs need special image types (e.g. U-Boot binary
2060 with a special header) as build targets. By defining
2061 CONFIG_BUILD_TARGET in the SoC / board header, this
2062 special image will be automatically built upon calling
2063 make / buildman.
2064
2065 CONFIG_IDENT_STRING
2066
2067 If defined, this string will be added to the U-Boot
2068 version information (U_BOOT_VERSION)
2069
2070 - Vendor Parameter Protection:
2071
2072 U-Boot considers the values of the environment
2073 variables "serial#" (Board Serial Number) and
2074 "ethaddr" (Ethernet Address) to be parameters that
2075 are set once by the board vendor / manufacturer, and
2076 protects these variables from casual modification by
2077 the user. Once set, these variables are read-only,
2078 and write or delete attempts are rejected. You can
2079 change this behaviour:
2080
2081 If CONFIG_ENV_OVERWRITE is #defined in your config
2082 file, the write protection for vendor parameters is
2083 completely disabled. Anybody can change or delete
2084 these parameters.
2085
2086 Alternatively, if you define _both_ an ethaddr in the
2087 default env _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
2088 Ethernet address is installed in the environment,
2089 which can be changed exactly ONCE by the user. [The
2090 serial# is unaffected by this, i. e. it remains
2091 read-only.]
2092
2093 The same can be accomplished in a more flexible way
2094 for any variable by configuring the type of access
2095 to allow for those variables in the ".flags" variable
2096 or define CONFIG_ENV_FLAGS_LIST_STATIC.
2097
2098 - Protected RAM:
2099 CONFIG_PRAM
2100
2101 Define this variable to enable the reservation of
2102 "protected RAM", i. e. RAM which is not overwritten
2103 by U-Boot. Define CONFIG_PRAM to hold the number of
2104 kB you want to reserve for pRAM. You can overwrite
2105 this default value by defining an environment
2106 variable "pram" to the number of kB you want to
2107 reserve. Note that the board info structure will
2108 still show the full amount of RAM. If pRAM is
2109 reserved, a new environment variable "mem" will
2110 automatically be defined to hold the amount of
2111 remaining RAM in a form that can be passed as boot
2112 argument to Linux, for instance like that:
2113
2114 setenv bootargs ... mem=\${mem}
2115 saveenv
2116
2117 This way you can tell Linux not to use this memory,
2118 either, which results in a memory region that will
2119 not be affected by reboots.
2120
2121 *WARNING* If your board configuration uses automatic
2122 detection of the RAM size, you must make sure that
2123 this memory test is non-destructive. So far, the
2124 following board configurations are known to be
2125 "pRAM-clean":
2126
2127 IVMS8, IVML24, SPD8xx,
2128 HERMES, IP860, RPXlite, LWMON,
2129 FLAGADM
2130
2131 - Access to physical memory region (> 4GB)
2132 Some basic support is provided for operations on memory not
2133 normally accessible to U-Boot - e.g. some architectures
2134 support access to more than 4GB of memory on 32-bit
2135 machines using physical address extension or similar.
2136 Define CONFIG_PHYSMEM to access this basic support, which
2137 currently only supports clearing the memory.
2138
2139 - Error Recovery:
2140 CONFIG_NET_RETRY_COUNT
2141
2142 This variable defines the number of retries for
2143 network operations like ARP, RARP, TFTP, or BOOTP
2144 before giving up the operation. If not defined, a
2145 default value of 5 is used.
2146
2147 CONFIG_ARP_TIMEOUT
2148
2149 Timeout waiting for an ARP reply in milliseconds.
2150
2151 CONFIG_NFS_TIMEOUT
2152
2153 Timeout in milliseconds used in NFS protocol.
2154 If you encounter "ERROR: Cannot umount" in nfs command,
2155 try longer timeout such as
2156 #define CONFIG_NFS_TIMEOUT 10000UL
2157
2158 - Command Interpreter:
2159 CONFIG_SYS_PROMPT_HUSH_PS2
2160
2161 This defines the secondary prompt string, which is
2162 printed when the command interpreter needs more input
2163 to complete a command. Usually "> ".
2164
2165 Note:
2166
2167 In the current implementation, the local variables
2168 space and global environment variables space are
2169 separated. Local variables are those you define by
2170 simply typing `name=value'. To access a local
2171 variable later on, you have write `$name' or
2172 `${name}'; to execute the contents of a variable
2173 directly type `$name' at the command prompt.
2174
2175 Global environment variables are those you use
2176 setenv/printenv to work with. To run a command stored
2177 in such a variable, you need to use the run command,
2178 and you must not use the '$' sign to access them.
2179
2180 To store commands and special characters in a
2181 variable, please use double quotation marks
2182 surrounding the whole text of the variable, instead
2183 of the backslashes before semicolons and special
2184 symbols.
2185
2186 - Command Line Editing and History:
2187 CONFIG_CMDLINE_PS_SUPPORT
2188
2189 Enable support for changing the command prompt string
2190 at run-time. Only static string is supported so far.
2191 The string is obtained from environment variables PS1
2192 and PS2.
2193
2194 - Default Environment:
2195 CONFIG_EXTRA_ENV_SETTINGS
2196
2197 Define this to contain any number of null terminated
2198 strings (variable = value pairs) that will be part of
2199 the default environment compiled into the boot image.
2200
2201 For example, place something like this in your
2202 board's config file:
2203
2204 #define CONFIG_EXTRA_ENV_SETTINGS \
2205 "myvar1=value1\0" \
2206 "myvar2=value2\0"
2207
2208 Warning: This method is based on knowledge about the
2209 internal format how the environment is stored by the
2210 U-Boot code. This is NOT an official, exported
2211 interface! Although it is unlikely that this format
2212 will change soon, there is no guarantee either.
2213 You better know what you are doing here.
2214
2215 Note: overly (ab)use of the default environment is
2216 discouraged. Make sure to check other ways to preset
2217 the environment like the "source" command or the
2218 boot command first.
2219
2220 CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG
2221
2222 Define this in order to add variables describing certain
2223 run-time determined information about the hardware to the
2224 environment. These will be named board_name, board_rev.
2225
2226 CONFIG_DELAY_ENVIRONMENT
2227
2228 Normally the environment is loaded when the board is
2229 initialised so that it is available to U-Boot. This inhibits
2230 that so that the environment is not available until
2231 explicitly loaded later by U-Boot code. With CONFIG_OF_CONTROL
2232 this is instead controlled by the value of
2233 /config/load-environment.
2234
2235 - Serial Flash support
2236 Usage requires an initial 'sf probe' to define the serial
2237 flash parameters, followed by read/write/erase/update
2238 commands.
2239
2240 The following defaults may be provided by the platform
2241 to handle the common case when only a single serial
2242 flash is present on the system.
2243
2244 CONFIG_SF_DEFAULT_BUS Bus identifier
2245 CONFIG_SF_DEFAULT_CS Chip-select
2246 CONFIG_SF_DEFAULT_MODE (see include/spi.h)
2247 CONFIG_SF_DEFAULT_SPEED in Hz
2248
2249
2250 - TFTP Fixed UDP Port:
2251 CONFIG_TFTP_PORT
2252
2253 If this is defined, the environment variable tftpsrcp
2254 is used to supply the TFTP UDP source port value.
2255 If tftpsrcp isn't defined, the normal pseudo-random port
2256 number generator is used.
2257
2258 Also, the environment variable tftpdstp is used to supply
2259 the TFTP UDP destination port value. If tftpdstp isn't
2260 defined, the normal port 69 is used.
2261
2262 The purpose for tftpsrcp is to allow a TFTP server to
2263 blindly start the TFTP transfer using the pre-configured
2264 target IP address and UDP port. This has the effect of
2265 "punching through" the (Windows XP) firewall, allowing
2266 the remainder of the TFTP transfer to proceed normally.
2267 A better solution is to properly configure the firewall,
2268 but sometimes that is not allowed.
2269
2270 - bootcount support:
2271 CONFIG_AT91SAM9XE
2272 enable special bootcounter support on at91sam9xe based boards.
2273 CONFIG_BOOTCOUNT_EXT
2274 enable support for the bootcounter in EXT filesystem
2275 CONFIG_SYS_BOOTCOUNT_ADDR = RAM address used for read
2276 and write.
2277 CONFIG_SYS_BOOTCOUNT_EXT_INTERFACE = interface
2278 CONFIG_SYS_BOOTCOUNT_EXT_DEVPART = device and part
2279 CONFIG_SYS_BOOTCOUNT_EXT_NAME = filename
2280
2281 - Show boot progress:
2282 CONFIG_SHOW_BOOT_PROGRESS
2283
2284 Defining this option allows to add some board-
2285 specific code (calling a user-provided function
2286 "show_boot_progress(int)") that enables you to show
2287 the system's boot progress on some display (for
2288 example, some LED's) on your board. At the moment,
2289 the following checkpoints are implemented:
2290
2291
2292 Legacy uImage format:
2293
2294 Arg Where When
2295 1 common/cmd_bootm.c before attempting to boot an image
2296 -1 common/cmd_bootm.c Image header has bad magic number
2297 2 common/cmd_bootm.c Image header has correct magic number
2298 -2 common/cmd_bootm.c Image header has bad checksum
2299 3 common/cmd_bootm.c Image header has correct checksum
2300 -3 common/cmd_bootm.c Image data has bad checksum
2301 4 common/cmd_bootm.c Image data has correct checksum
2302 -4 common/cmd_bootm.c Image is for unsupported architecture
2303 5 common/cmd_bootm.c Architecture check OK
2304 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi)
2305 6 common/cmd_bootm.c Image Type check OK
2306 -6 common/cmd_bootm.c gunzip uncompression error
2307 -7 common/cmd_bootm.c Unimplemented compression type
2308 7 common/cmd_bootm.c Uncompression OK
2309 8 common/cmd_bootm.c No uncompress/copy overwrite error
2310 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX)
2311
2312 9 common/image.c Start initial ramdisk verification
2313 -10 common/image.c Ramdisk header has bad magic number
2314 -11 common/image.c Ramdisk header has bad checksum
2315 10 common/image.c Ramdisk header is OK
2316 -12 common/image.c Ramdisk data has bad checksum
2317 11 common/image.c Ramdisk data has correct checksum
2318 12 common/image.c Ramdisk verification complete, start loading
2319 -13 common/image.c Wrong Image Type (not PPC Linux ramdisk)
2320 13 common/image.c Start multifile image verification
2321 14 common/image.c No initial ramdisk, no multifile, continue.
2322
2323 15 arch/<arch>/lib/bootm.c All preparation done, transferring control to OS
2324
2325 -30 arch/powerpc/lib/board.c Fatal error, hang the system
2326 -31 post/post.c POST test failed, detected by post_output_backlog()
2327 -32 post/post.c POST test failed, detected by post_run_single()
2328
2329 34 common/cmd_doc.c before loading a Image from a DOC device
2330 -35 common/cmd_doc.c Bad usage of "doc" command
2331 35 common/cmd_doc.c correct usage of "doc" command
2332 -36 common/cmd_doc.c No boot device
2333 36 common/cmd_doc.c correct boot device
2334 -37 common/cmd_doc.c Unknown Chip ID on boot device
2335 37 common/cmd_doc.c correct chip ID found, device available
2336 -38 common/cmd_doc.c Read Error on boot device
2337 38 common/cmd_doc.c reading Image header from DOC device OK
2338 -39 common/cmd_doc.c Image header has bad magic number
2339 39 common/cmd_doc.c Image header has correct magic number
2340 -40 common/cmd_doc.c Error reading Image from DOC device
2341 40 common/cmd_doc.c Image header has correct magic number
2342 41 common/cmd_ide.c before loading a Image from a IDE device
2343 -42 common/cmd_ide.c Bad usage of "ide" command
2344 42 common/cmd_ide.c correct usage of "ide" command
2345 -43 common/cmd_ide.c No boot device
2346 43 common/cmd_ide.c boot device found
2347 -44 common/cmd_ide.c Device not available
2348 44 common/cmd_ide.c Device available
2349 -45 common/cmd_ide.c wrong partition selected
2350 45 common/cmd_ide.c partition selected
2351 -46 common/cmd_ide.c Unknown partition table
2352 46 common/cmd_ide.c valid partition table found
2353 -47 common/cmd_ide.c Invalid partition type
2354 47 common/cmd_ide.c correct partition type
2355 -48 common/cmd_ide.c Error reading Image Header on boot device
2356 48 common/cmd_ide.c reading Image Header from IDE device OK
2357 -49 common/cmd_ide.c Image header has bad magic number
2358 49 common/cmd_ide.c Image header has correct magic number
2359 -50 common/cmd_ide.c Image header has bad checksum
2360 50 common/cmd_ide.c Image header has correct checksum
2361 -51 common/cmd_ide.c Error reading Image from IDE device
2362 51 common/cmd_ide.c reading Image from IDE device OK
2363 52 common/cmd_nand.c before loading a Image from a NAND device
2364 -53 common/cmd_nand.c Bad usage of "nand" command
2365 53 common/cmd_nand.c correct usage of "nand" command
2366 -54 common/cmd_nand.c No boot device
2367 54 common/cmd_nand.c boot device found
2368 -55 common/cmd_nand.c Unknown Chip ID on boot device
2369 55 common/cmd_nand.c correct chip ID found, device available
2370 -56 common/cmd_nand.c Error reading Image Header on boot device
2371 56 common/cmd_nand.c reading Image Header from NAND device OK
2372 -57 common/cmd_nand.c Image header has bad magic number
2373 57 common/cmd_nand.c Image header has correct magic number
2374 -58 common/cmd_nand.c Error reading Image from NAND device
2375 58 common/cmd_nand.c reading Image from NAND device OK
2376
2377 -60 common/env_common.c Environment has a bad CRC, using default
2378
2379 64 net/eth.c starting with Ethernet configuration.
2380 -64 net/eth.c no Ethernet found.
2381 65 net/eth.c Ethernet found.
2382
2383 -80 common/cmd_net.c usage wrong
2384 80 common/cmd_net.c before calling net_loop()
2385 -81 common/cmd_net.c some error in net_loop() occurred
2386 81 common/cmd_net.c net_loop() back without error
2387 -82 common/cmd_net.c size == 0 (File with size 0 loaded)
2388 82 common/cmd_net.c trying automatic boot
2389 83 common/cmd_net.c running "source" command
2390 -83 common/cmd_net.c some error in automatic boot or "source" command
2391 84 common/cmd_net.c end without errors
2392
2393 FIT uImage format:
2394
2395 Arg Where When
2396 100 common/cmd_bootm.c Kernel FIT Image has correct format
2397 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format
2398 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration
2399 -101 common/cmd_bootm.c Can't get configuration for kernel subimage
2400 102 common/cmd_bootm.c Kernel unit name specified
2401 -103 common/cmd_bootm.c Can't get kernel subimage node offset
2402 103 common/cmd_bootm.c Found configuration node
2403 104 common/cmd_bootm.c Got kernel subimage node offset
2404 -104 common/cmd_bootm.c Kernel subimage hash verification failed
2405 105 common/cmd_bootm.c Kernel subimage hash verification OK
2406 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture
2407 106 common/cmd_bootm.c Architecture check OK
2408 -106 common/cmd_bootm.c Kernel subimage has wrong type
2409 107 common/cmd_bootm.c Kernel subimage type OK
2410 -107 common/cmd_bootm.c Can't get kernel subimage data/size
2411 108 common/cmd_bootm.c Got kernel subimage data/size
2412 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT)
2413 -109 common/cmd_bootm.c Can't get kernel subimage type
2414 -110 common/cmd_bootm.c Can't get kernel subimage comp
2415 -111 common/cmd_bootm.c Can't get kernel subimage os
2416 -112 common/cmd_bootm.c Can't get kernel subimage load address
2417 -113 common/cmd_bootm.c Image uncompress/copy overwrite error
2418
2419 120 common/image.c Start initial ramdisk verification
2420 -120 common/image.c Ramdisk FIT image has incorrect format
2421 121 common/image.c Ramdisk FIT image has correct format
2422 122 common/image.c No ramdisk subimage unit name, using configuration
2423 -122 common/image.c Can't get configuration for ramdisk subimage
2424 123 common/image.c Ramdisk unit name specified
2425 -124 common/image.c Can't get ramdisk subimage node offset
2426 125 common/image.c Got ramdisk subimage node offset
2427 -125 common/image.c Ramdisk subimage hash verification failed
2428 126 common/image.c Ramdisk subimage hash verification OK
2429 -126 common/image.c Ramdisk subimage for unsupported architecture
2430 127 common/image.c Architecture check OK
2431 -127 common/image.c Can't get ramdisk subimage data/size
2432 128 common/image.c Got ramdisk subimage data/size
2433 129 common/image.c Can't get ramdisk load address
2434 -129 common/image.c Got ramdisk load address
2435
2436 -130 common/cmd_doc.c Incorrect FIT image format
2437 131 common/cmd_doc.c FIT image format OK
2438
2439 -140 common/cmd_ide.c Incorrect FIT image format
2440 141 common/cmd_ide.c FIT image format OK
2441
2442 -150 common/cmd_nand.c Incorrect FIT image format
2443 151 common/cmd_nand.c FIT image format OK
2444
2445 - legacy image format:
2446 CONFIG_IMAGE_FORMAT_LEGACY
2447 enables the legacy image format support in U-Boot.
2448
2449 Default:
2450 enabled if CONFIG_FIT_SIGNATURE is not defined.
2451
2452 CONFIG_DISABLE_IMAGE_LEGACY
2453 disable the legacy image format
2454
2455 This define is introduced, as the legacy image format is
2456 enabled per default for backward compatibility.
2457
2458 - Standalone program support:
2459 CONFIG_STANDALONE_LOAD_ADDR
2460
2461 This option defines a board specific value for the
2462 address where standalone program gets loaded, thus
2463 overwriting the architecture dependent default
2464 settings.
2465
2466 - Frame Buffer Address:
2467 CONFIG_FB_ADDR
2468
2469 Define CONFIG_FB_ADDR if you want to use specific
2470 address for frame buffer. This is typically the case
2471 when using a graphics controller has separate video
2472 memory. U-Boot will then place the frame buffer at
2473 the given address instead of dynamically reserving it
2474 in system RAM by calling lcd_setmem(), which grabs
2475 the memory for the frame buffer depending on the
2476 configured panel size.
2477
2478 Please see board_init_f function.
2479
2480 - Automatic software updates via TFTP server
2481 CONFIG_UPDATE_TFTP
2482 CONFIG_UPDATE_TFTP_CNT_MAX
2483 CONFIG_UPDATE_TFTP_MSEC_MAX
2484
2485 These options enable and control the auto-update feature;
2486 for a more detailed description refer to doc/README.update.
2487
2488 - MTD Support (mtdparts command, UBI support)
2489 CONFIG_MTD_DEVICE
2490
2491 Adds the MTD device infrastructure from the Linux kernel.
2492 Needed for mtdparts command support.
2493
2494 CONFIG_MTD_PARTITIONS
2495
2496 Adds the MTD partitioning infrastructure from the Linux
2497 kernel. Needed for UBI support.
2498
2499 - UBI support
2500 CONFIG_UBI_SILENCE_MSG
2501
2502 Make the verbose messages from UBI stop printing. This leaves
2503 warnings and errors enabled.
2504
2505
2506 CONFIG_MTD_UBI_WL_THRESHOLD
2507 This parameter defines the maximum difference between the highest
2508 erase counter value and the lowest erase counter value of eraseblocks
2509 of UBI devices. When this threshold is exceeded, UBI starts performing
2510 wear leveling by means of moving data from eraseblock with low erase
2511 counter to eraseblocks with high erase counter.
2512
2513 The default value should be OK for SLC NAND flashes, NOR flashes and
2514 other flashes which have eraseblock life-cycle 100000 or more.
2515 However, in case of MLC NAND flashes which typically have eraseblock
2516 life-cycle less than 10000, the threshold should be lessened (e.g.,
2517 to 128 or 256, although it does not have to be power of 2).
2518
2519 default: 4096
2520
2521 CONFIG_MTD_UBI_BEB_LIMIT
2522 This option specifies the maximum bad physical eraseblocks UBI
2523 expects on the MTD device (per 1024 eraseblocks). If the
2524 underlying flash does not admit of bad eraseblocks (e.g. NOR
2525 flash), this value is ignored.
2526
2527 NAND datasheets often specify the minimum and maximum NVM
2528 (Number of Valid Blocks) for the flashes' endurance lifetime.
2529 The maximum expected bad eraseblocks per 1024 eraseblocks
2530 then can be calculated as "1024 * (1 - MinNVB / MaxNVB)",
2531 which gives 20 for most NANDs (MaxNVB is basically the total
2532 count of eraseblocks on the chip).
2533
2534 To put it differently, if this value is 20, UBI will try to
2535 reserve about 1.9% of physical eraseblocks for bad blocks
2536 handling. And that will be 1.9% of eraseblocks on the entire
2537 NAND chip, not just the MTD partition UBI attaches. This means
2538 that if you have, say, a NAND flash chip admits maximum 40 bad
2539 eraseblocks, and it is split on two MTD partitions of the same
2540 size, UBI will reserve 40 eraseblocks when attaching a
2541 partition.
2542
2543 default: 20
2544
2545 CONFIG_MTD_UBI_FASTMAP
2546 Fastmap is a mechanism which allows attaching an UBI device
2547 in nearly constant time. Instead of scanning the whole MTD device it
2548 only has to locate a checkpoint (called fastmap) on the device.
2549 The on-flash fastmap contains all information needed to attach
2550 the device. Using fastmap makes only sense on large devices where
2551 attaching by scanning takes long. UBI will not automatically install
2552 a fastmap on old images, but you can set the UBI parameter
2553 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT to 1 if you want so. Please note
2554 that fastmap-enabled images are still usable with UBI implementations
2555 without fastmap support. On typical flash devices the whole fastmap
2556 fits into one PEB. UBI will reserve PEBs to hold two fastmaps.
2557
2558 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT
2559 Set this parameter to enable fastmap automatically on images
2560 without a fastmap.
2561 default: 0
2562
2563 CONFIG_MTD_UBI_FM_DEBUG
2564 Enable UBI fastmap debug
2565 default: 0
2566
2567 - UBIFS support
2568 CONFIG_UBIFS_SILENCE_MSG
2569
2570 Make the verbose messages from UBIFS stop printing. This leaves
2571 warnings and errors enabled.
2572
2573 - SPL framework
2574 CONFIG_SPL
2575 Enable building of SPL globally.
2576
2577 CONFIG_SPL_LDSCRIPT
2578 LDSCRIPT for linking the SPL binary.
2579
2580 CONFIG_SPL_MAX_FOOTPRINT
2581 Maximum size in memory allocated to the SPL, BSS included.
2582 When defined, the linker checks that the actual memory
2583 used by SPL from _start to __bss_end does not exceed it.
2584 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
2585 must not be both defined at the same time.
2586
2587 CONFIG_SPL_MAX_SIZE
2588 Maximum size of the SPL image (text, data, rodata, and
2589 linker lists sections), BSS excluded.
2590 When defined, the linker checks that the actual size does
2591 not exceed it.
2592
2593 CONFIG_SPL_TEXT_BASE
2594 TEXT_BASE for linking the SPL binary.
2595
2596 CONFIG_SPL_RELOC_TEXT_BASE
2597 Address to relocate to. If unspecified, this is equal to
2598 CONFIG_SPL_TEXT_BASE (i.e. no relocation is done).
2599
2600 CONFIG_SPL_BSS_START_ADDR
2601 Link address for the BSS within the SPL binary.
2602
2603 CONFIG_SPL_BSS_MAX_SIZE
2604 Maximum size in memory allocated to the SPL BSS.
2605 When defined, the linker checks that the actual memory used
2606 by SPL from __bss_start to __bss_end does not exceed it.
2607 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
2608 must not be both defined at the same time.
2609
2610 CONFIG_SPL_STACK
2611 Adress of the start of the stack SPL will use
2612
2613 CONFIG_SPL_PANIC_ON_RAW_IMAGE
2614 When defined, SPL will panic() if the image it has
2615 loaded does not have a signature.
2616 Defining this is useful when code which loads images
2617 in SPL cannot guarantee that absolutely all read errors
2618 will be caught.
2619 An example is the LPC32XX MLC NAND driver, which will
2620 consider that a completely unreadable NAND block is bad,
2621 and thus should be skipped silently.
2622
2623 CONFIG_SPL_RELOC_STACK
2624 Adress of the start of the stack SPL will use after
2625 relocation. If unspecified, this is equal to
2626 CONFIG_SPL_STACK.
2627
2628 CONFIG_SYS_SPL_MALLOC_START
2629 Starting address of the malloc pool used in SPL.
2630 When this option is set the full malloc is used in SPL and
2631 it is set up by spl_init() and before that, the simple malloc()
2632 can be used if CONFIG_SYS_MALLOC_F is defined.
2633
2634 CONFIG_SYS_SPL_MALLOC_SIZE
2635 The size of the malloc pool used in SPL.
2636
2637 CONFIG_SPL_OS_BOOT
2638 Enable booting directly to an OS from SPL.
2639 See also: doc/README.falcon
2640
2641 CONFIG_SPL_DISPLAY_PRINT
2642 For ARM, enable an optional function to print more information
2643 about the running system.
2644
2645 CONFIG_SPL_INIT_MINIMAL
2646 Arch init code should be built for a very small image
2647
2648 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_PARTITION
2649 Partition on the MMC to load U-Boot from when the MMC is being
2650 used in raw mode
2651
2652 CONFIG_SYS_MMCSD_RAW_MODE_KERNEL_SECTOR
2653 Sector to load kernel uImage from when MMC is being
2654 used in raw mode (for Falcon mode)
2655
2656 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTOR,
2657 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTORS
2658 Sector and number of sectors to load kernel argument
2659 parameters from when MMC is being used in raw mode
2660 (for falcon mode)
2661
2662 CONFIG_SYS_MMCSD_FS_BOOT_PARTITION
2663 Partition on the MMC to load U-Boot from when the MMC is being
2664 used in fs mode
2665
2666 CONFIG_SPL_FS_LOAD_PAYLOAD_NAME
2667 Filename to read to load U-Boot when reading from filesystem
2668
2669 CONFIG_SPL_FS_LOAD_KERNEL_NAME
2670 Filename to read to load kernel uImage when reading
2671 from filesystem (for Falcon mode)
2672
2673 CONFIG_SPL_FS_LOAD_ARGS_NAME
2674 Filename to read to load kernel argument parameters
2675 when reading from filesystem (for Falcon mode)
2676
2677 CONFIG_SPL_MPC83XX_WAIT_FOR_NAND
2678 Set this for NAND SPL on PPC mpc83xx targets, so that
2679 start.S waits for the rest of the SPL to load before
2680 continuing (the hardware starts execution after just
2681 loading the first page rather than the full 4K).
2682
2683 CONFIG_SPL_SKIP_RELOCATE
2684 Avoid SPL relocation
2685
2686 CONFIG_SPL_NAND_BASE
2687 Include nand_base.c in the SPL. Requires
2688 CONFIG_SPL_NAND_DRIVERS.
2689
2690 CONFIG_SPL_NAND_DRIVERS
2691 SPL uses normal NAND drivers, not minimal drivers.
2692
2693 CONFIG_SPL_NAND_ECC
2694 Include standard software ECC in the SPL
2695
2696 CONFIG_SPL_NAND_SIMPLE
2697 Support for NAND boot using simple NAND drivers that
2698 expose the cmd_ctrl() interface.
2699
2700 CONFIG_SPL_UBI
2701 Support for a lightweight UBI (fastmap) scanner and
2702 loader
2703
2704 CONFIG_SPL_NAND_RAW_ONLY
2705 Support to boot only raw u-boot.bin images. Use this only
2706 if you need to save space.
2707
2708 CONFIG_SPL_COMMON_INIT_DDR
2709 Set for common ddr init with serial presence detect in
2710 SPL binary.
2711
2712 CONFIG_SYS_NAND_5_ADDR_CYCLE, CONFIG_SYS_NAND_PAGE_COUNT,
2713 CONFIG_SYS_NAND_PAGE_SIZE, CONFIG_SYS_NAND_OOBSIZE,
2714 CONFIG_SYS_NAND_BLOCK_SIZE, CONFIG_SYS_NAND_BAD_BLOCK_POS,
2715 CONFIG_SYS_NAND_ECCPOS, CONFIG_SYS_NAND_ECCSIZE,
2716 CONFIG_SYS_NAND_ECCBYTES
2717 Defines the size and behavior of the NAND that SPL uses
2718 to read U-Boot
2719
2720 CONFIG_SPL_NAND_BOOT
2721 Add support NAND boot
2722
2723 CONFIG_SYS_NAND_U_BOOT_OFFS
2724 Location in NAND to read U-Boot from
2725
2726 CONFIG_SYS_NAND_U_BOOT_DST
2727 Location in memory to load U-Boot to
2728
2729 CONFIG_SYS_NAND_U_BOOT_SIZE
2730 Size of image to load
2731
2732 CONFIG_SYS_NAND_U_BOOT_START
2733 Entry point in loaded image to jump to
2734
2735 CONFIG_SYS_NAND_HW_ECC_OOBFIRST
2736 Define this if you need to first read the OOB and then the
2737 data. This is used, for example, on davinci platforms.
2738
2739 CONFIG_SPL_RAM_DEVICE
2740 Support for running image already present in ram, in SPL binary
2741
2742 CONFIG_SPL_PAD_TO
2743 Image offset to which the SPL should be padded before appending
2744 the SPL payload. By default, this is defined as
2745 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
2746 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
2747 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
2748
2749 CONFIG_SPL_TARGET
2750 Final target image containing SPL and payload. Some SPLs
2751 use an arch-specific makefile fragment instead, for
2752 example if more than one image needs to be produced.
2753
2754 CONFIG_FIT_SPL_PRINT
2755 Printing information about a FIT image adds quite a bit of
2756 code to SPL. So this is normally disabled in SPL. Use this
2757 option to re-enable it. This will affect the output of the
2758 bootm command when booting a FIT image.
2759
2760 - TPL framework
2761 CONFIG_TPL
2762 Enable building of TPL globally.
2763
2764 CONFIG_TPL_PAD_TO
2765 Image offset to which the TPL should be padded before appending
2766 the TPL payload. By default, this is defined as
2767 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
2768 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
2769 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
2770
2771 - Interrupt support (PPC):
2772
2773 There are common interrupt_init() and timer_interrupt()
2774 for all PPC archs. interrupt_init() calls interrupt_init_cpu()
2775 for CPU specific initialization. interrupt_init_cpu()
2776 should set decrementer_count to appropriate value. If
2777 CPU resets decrementer automatically after interrupt
2778 (ppc4xx) it should set decrementer_count to zero.
2779 timer_interrupt() calls timer_interrupt_cpu() for CPU
2780 specific handling. If board has watchdog / status_led
2781 / other_activity_monitor it works automatically from
2782 general timer_interrupt().
2783
2784
2785 Board initialization settings:
2786 ------------------------------
2787
2788 During Initialization u-boot calls a number of board specific functions
2789 to allow the preparation of board specific prerequisites, e.g. pin setup
2790 before drivers are initialized. To enable these callbacks the
2791 following configuration macros have to be defined. Currently this is
2792 architecture specific, so please check arch/your_architecture/lib/board.c
2793 typically in board_init_f() and board_init_r().
2794
2795 - CONFIG_BOARD_EARLY_INIT_F: Call board_early_init_f()
2796 - CONFIG_BOARD_EARLY_INIT_R: Call board_early_init_r()
2797 - CONFIG_BOARD_LATE_INIT: Call board_late_init()
2798 - CONFIG_BOARD_POSTCLK_INIT: Call board_postclk_init()
2799
2800 Configuration Settings:
2801 -----------------------
2802
2803 - CONFIG_SYS_SUPPORT_64BIT_DATA: Defined automatically if compiled as 64-bit.
2804 Optionally it can be defined to support 64-bit memory commands.
2805
2806 - CONFIG_SYS_LONGHELP: Defined when you want long help messages included;
2807 undefine this when you're short of memory.
2808
2809 - CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default
2810 width of the commands listed in the 'help' command output.
2811
2812 - CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to
2813 prompt for user input.
2814
2815 - CONFIG_SYS_CBSIZE: Buffer size for input from the Console
2816
2817 - CONFIG_SYS_PBSIZE: Buffer size for Console output
2818
2819 - CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands
2820
2821 - CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to
2822 the application (usually a Linux kernel) when it is
2823 booted
2824
2825 - CONFIG_SYS_BAUDRATE_TABLE:
2826 List of legal baudrate settings for this board.
2827
2828 - CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END:
2829 Begin and End addresses of the area used by the
2830 simple memory test.
2831
2832 - CONFIG_SYS_ALT_MEMTEST:
2833 Enable an alternate, more extensive memory test.
2834
2835 - CONFIG_SYS_MEMTEST_SCRATCH:
2836 Scratch address used by the alternate memory test
2837 You only need to set this if address zero isn't writeable
2838
2839 - CONFIG_SYS_MEM_RESERVE_SECURE
2840 Only implemented for ARMv8 for now.
2841 If defined, the size of CONFIG_SYS_MEM_RESERVE_SECURE memory
2842 is substracted from total RAM and won't be reported to OS.
2843 This memory can be used as secure memory. A variable
2844 gd->arch.secure_ram is used to track the location. In systems
2845 the RAM base is not zero, or RAM is divided into banks,
2846 this variable needs to be recalcuated to get the address.
2847
2848 - CONFIG_SYS_MEM_TOP_HIDE:
2849 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header,
2850 this specified memory area will get subtracted from the top
2851 (end) of RAM and won't get "touched" at all by U-Boot. By
2852 fixing up gd->ram_size the Linux kernel should gets passed
2853 the now "corrected" memory size and won't touch it either.
2854 This should work for arch/ppc and arch/powerpc. Only Linux
2855 board ports in arch/powerpc with bootwrapper support that
2856 recalculate the memory size from the SDRAM controller setup
2857 will have to get fixed in Linux additionally.
2858
2859 This option can be used as a workaround for the 440EPx/GRx
2860 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't
2861 be touched.
2862
2863 WARNING: Please make sure that this value is a multiple of
2864 the Linux page size (normally 4k). If this is not the case,
2865 then the end address of the Linux memory will be located at a
2866 non page size aligned address and this could cause major
2867 problems.
2868
2869 - CONFIG_SYS_LOADS_BAUD_CHANGE:
2870 Enable temporary baudrate change while serial download
2871
2872 - CONFIG_SYS_SDRAM_BASE:
2873 Physical start address of SDRAM. _Must_ be 0 here.
2874
2875 - CONFIG_SYS_FLASH_BASE:
2876 Physical start address of Flash memory.
2877
2878 - CONFIG_SYS_MONITOR_BASE:
2879 Physical start address of boot monitor code (set by
2880 make config files to be same as the text base address
2881 (CONFIG_SYS_TEXT_BASE) used when linking) - same as
2882 CONFIG_SYS_FLASH_BASE when booting from flash.
2883
2884 - CONFIG_SYS_MONITOR_LEN:
2885 Size of memory reserved for monitor code, used to
2886 determine _at_compile_time_ (!) if the environment is
2887 embedded within the U-Boot image, or in a separate
2888 flash sector.
2889
2890 - CONFIG_SYS_MALLOC_LEN:
2891 Size of DRAM reserved for malloc() use.
2892
2893 - CONFIG_SYS_MALLOC_F_LEN
2894 Size of the malloc() pool for use before relocation. If
2895 this is defined, then a very simple malloc() implementation
2896 will become available before relocation. The address is just
2897 below the global data, and the stack is moved down to make
2898 space.
2899
2900 This feature allocates regions with increasing addresses
2901 within the region. calloc() is supported, but realloc()
2902 is not available. free() is supported but does nothing.
2903 The memory will be freed (or in fact just forgotten) when
2904 U-Boot relocates itself.
2905
2906 - CONFIG_SYS_MALLOC_SIMPLE
2907 Provides a simple and small malloc() and calloc() for those
2908 boards which do not use the full malloc in SPL (which is
2909 enabled with CONFIG_SYS_SPL_MALLOC_START).
2910
2911 - CONFIG_SYS_NONCACHED_MEMORY:
2912 Size of non-cached memory area. This area of memory will be
2913 typically located right below the malloc() area and mapped
2914 uncached in the MMU. This is useful for drivers that would
2915 otherwise require a lot of explicit cache maintenance. For
2916 some drivers it's also impossible to properly maintain the
2917 cache. For example if the regions that need to be flushed
2918 are not a multiple of the cache-line size, *and* padding
2919 cannot be allocated between the regions to align them (i.e.
2920 if the HW requires a contiguous array of regions, and the
2921 size of each region is not cache-aligned), then a flush of
2922 one region may result in overwriting data that hardware has
2923 written to another region in the same cache-line. This can
2924 happen for example in network drivers where descriptors for
2925 buffers are typically smaller than the CPU cache-line (e.g.
2926 16 bytes vs. 32 or 64 bytes).
2927
2928 Non-cached memory is only supported on 32-bit ARM at present.
2929
2930 - CONFIG_SYS_BOOTM_LEN:
2931 Normally compressed uImages are limited to an
2932 uncompressed size of 8 MBytes. If this is not enough,
2933 you can define CONFIG_SYS_BOOTM_LEN in your board config file
2934 to adjust this setting to your needs.
2935
2936 - CONFIG_SYS_BOOTMAPSZ:
2937 Maximum size of memory mapped by the startup code of
2938 the Linux kernel; all data that must be processed by
2939 the Linux kernel (bd_info, boot arguments, FDT blob if
2940 used) must be put below this limit, unless "bootm_low"
2941 environment variable is defined and non-zero. In such case
2942 all data for the Linux kernel must be between "bootm_low"
2943 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ. The environment
2944 variable "bootm_mapsize" will override the value of
2945 CONFIG_SYS_BOOTMAPSZ. If CONFIG_SYS_BOOTMAPSZ is undefined,
2946 then the value in "bootm_size" will be used instead.
2947
2948 - CONFIG_SYS_BOOT_RAMDISK_HIGH:
2949 Enable initrd_high functionality. If defined then the
2950 initrd_high feature is enabled and the bootm ramdisk subcommand
2951 is enabled.
2952
2953 - CONFIG_SYS_BOOT_GET_CMDLINE:
2954 Enables allocating and saving kernel cmdline in space between
2955 "bootm_low" and "bootm_low" + BOOTMAPSZ.
2956
2957 - CONFIG_SYS_BOOT_GET_KBD:
2958 Enables allocating and saving a kernel copy of the bd_info in
2959 space between "bootm_low" and "bootm_low" + BOOTMAPSZ.
2960
2961 - CONFIG_SYS_MAX_FLASH_BANKS:
2962 Max number of Flash memory banks
2963
2964 - CONFIG_SYS_MAX_FLASH_SECT:
2965 Max number of sectors on a Flash chip
2966
2967 - CONFIG_SYS_FLASH_ERASE_TOUT:
2968 Timeout for Flash erase operations (in ms)
2969
2970 - CONFIG_SYS_FLASH_WRITE_TOUT:
2971 Timeout for Flash write operations (in ms)
2972
2973 - CONFIG_SYS_FLASH_LOCK_TOUT
2974 Timeout for Flash set sector lock bit operation (in ms)
2975
2976 - CONFIG_SYS_FLASH_UNLOCK_TOUT
2977 Timeout for Flash clear lock bits operation (in ms)
2978
2979 - CONFIG_SYS_FLASH_PROTECTION
2980 If defined, hardware flash sectors protection is used
2981 instead of U-Boot software protection.
2982
2983 - CONFIG_SYS_DIRECT_FLASH_TFTP:
2984
2985 Enable TFTP transfers directly to flash memory;
2986 without this option such a download has to be
2987 performed in two steps: (1) download to RAM, and (2)
2988 copy from RAM to flash.
2989
2990 The two-step approach is usually more reliable, since
2991 you can check if the download worked before you erase
2992 the flash, but in some situations (when system RAM is
2993 too limited to allow for a temporary copy of the
2994 downloaded image) this option may be very useful.
2995
2996 - CONFIG_SYS_FLASH_CFI:
2997 Define if the flash driver uses extra elements in the
2998 common flash structure for storing flash geometry.
2999
3000 - CONFIG_FLASH_CFI_DRIVER
3001 This option also enables the building of the cfi_flash driver
3002 in the drivers directory
3003
3004 - CONFIG_FLASH_CFI_MTD
3005 This option enables the building of the cfi_mtd driver
3006 in the drivers directory. The driver exports CFI flash
3007 to the MTD layer.
3008
3009 - CONFIG_SYS_FLASH_USE_BUFFER_WRITE
3010 Use buffered writes to flash.
3011
3012 - CONFIG_FLASH_SPANSION_S29WS_N
3013 s29ws-n MirrorBit flash has non-standard addresses for buffered
3014 write commands.
3015
3016 - CONFIG_SYS_FLASH_QUIET_TEST
3017 If this option is defined, the common CFI flash doesn't
3018 print it's warning upon not recognized FLASH banks. This
3019 is useful, if some of the configured banks are only
3020 optionally available.
3021
3022 - CONFIG_FLASH_SHOW_PROGRESS
3023 If defined (must be an integer), print out countdown
3024 digits and dots. Recommended value: 45 (9..1) for 80
3025 column displays, 15 (3..1) for 40 column displays.
3026
3027 - CONFIG_FLASH_VERIFY
3028 If defined, the content of the flash (destination) is compared
3029 against the source after the write operation. An error message
3030 will be printed when the contents are not identical.
3031 Please note that this option is useless in nearly all cases,
3032 since such flash programming errors usually are detected earlier
3033 while unprotecting/erasing/programming. Please only enable
3034 this option if you really know what you are doing.
3035
3036 - CONFIG_SYS_RX_ETH_BUFFER:
3037 Defines the number of Ethernet receive buffers. On some
3038 Ethernet controllers it is recommended to set this value
3039 to 8 or even higher (EEPRO100 or 405 EMAC), since all
3040 buffers can be full shortly after enabling the interface
3041 on high Ethernet traffic.
3042 Defaults to 4 if not defined.
3043
3044 - CONFIG_ENV_MAX_ENTRIES
3045
3046 Maximum number of entries in the hash table that is used
3047 internally to store the environment settings. The default
3048 setting is supposed to be generous and should work in most
3049 cases. This setting can be used to tune behaviour; see
3050 lib/hashtable.c for details.
3051
3052 - CONFIG_ENV_FLAGS_LIST_DEFAULT
3053 - CONFIG_ENV_FLAGS_LIST_STATIC
3054 Enable validation of the values given to environment variables when
3055 calling env set. Variables can be restricted to only decimal,
3056 hexadecimal, or boolean. If CONFIG_CMD_NET is also defined,
3057 the variables can also be restricted to IP address or MAC address.
3058
3059 The format of the list is:
3060 type_attribute = [s|d|x|b|i|m]
3061 access_attribute = [a|r|o|c]
3062 attributes = type_attribute[access_attribute]
3063 entry = variable_name[:attributes]
3064 list = entry[,list]
3065
3066 The type attributes are:
3067 s - String (default)
3068 d - Decimal
3069 x - Hexadecimal
3070 b - Boolean ([1yYtT|0nNfF])
3071 i - IP address
3072 m - MAC address
3073
3074 The access attributes are:
3075 a - Any (default)
3076 r - Read-only
3077 o - Write-once
3078 c - Change-default
3079
3080 - CONFIG_ENV_FLAGS_LIST_DEFAULT
3081 Define this to a list (string) to define the ".flags"
3082 environment variable in the default or embedded environment.
3083
3084 - CONFIG_ENV_FLAGS_LIST_STATIC
3085 Define this to a list (string) to define validation that
3086 should be done if an entry is not found in the ".flags"
3087 environment variable. To override a setting in the static
3088 list, simply add an entry for the same variable name to the
3089 ".flags" variable.
3090
3091 If CONFIG_REGEX is defined, the variable_name above is evaluated as a
3092 regular expression. This allows multiple variables to define the same
3093 flags without explicitly listing them for each variable.
3094
3095 - CONFIG_ENV_ACCESS_IGNORE_FORCE
3096 If defined, don't allow the -f switch to env set override variable
3097 access flags.
3098
3099 - CONFIG_USE_STDINT
3100 If stdint.h is available with your toolchain you can define this
3101 option to enable it. You can provide option 'USE_STDINT=1' when
3102 building U-Boot to enable this.
3103
3104 The following definitions that deal with the placement and management
3105 of environment data (variable area); in general, we support the
3106 following configurations:
3107
3108 - CONFIG_BUILD_ENVCRC:
3109
3110 Builds up envcrc with the target environment so that external utils
3111 may easily extract it and embed it in final U-Boot images.
3112
3113 BE CAREFUL! The first access to the environment happens quite early
3114 in U-Boot initialization (when we try to get the setting of for the
3115 console baudrate). You *MUST* have mapped your NVRAM area then, or
3116 U-Boot will hang.
3117
3118 Please note that even with NVRAM we still use a copy of the
3119 environment in RAM: we could work on NVRAM directly, but we want to
3120 keep settings there always unmodified except somebody uses "saveenv"
3121 to save the current settings.
3122
3123 BE CAREFUL! For some special cases, the local device can not use
3124 "saveenv" command. For example, the local device will get the
3125 environment stored in a remote NOR flash by SRIO or PCIE link,
3126 but it can not erase, write this NOR flash by SRIO or PCIE interface.
3127
3128 - CONFIG_NAND_ENV_DST
3129
3130 Defines address in RAM to which the nand_spl code should copy the
3131 environment. If redundant environment is used, it will be copied to
3132 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE.
3133
3134 Please note that the environment is read-only until the monitor
3135 has been relocated to RAM and a RAM copy of the environment has been
3136 created; also, when using EEPROM you will have to use env_get_f()
3137 until then to read environment variables.
3138
3139 The environment is protected by a CRC32 checksum. Before the monitor
3140 is relocated into RAM, as a result of a bad CRC you will be working
3141 with the compiled-in default environment - *silently*!!! [This is
3142 necessary, because the first environment variable we need is the
3143 "baudrate" setting for the console - if we have a bad CRC, we don't
3144 have any device yet where we could complain.]
3145
3146 Note: once the monitor has been relocated, then it will complain if
3147 the default environment is used; a new CRC is computed as soon as you
3148 use the "saveenv" command to store a valid environment.
3149
3150 - CONFIG_SYS_FAULT_ECHO_LINK_DOWN:
3151 Echo the inverted Ethernet link state to the fault LED.
3152
3153 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR
3154 also needs to be defined.
3155
3156 - CONFIG_SYS_FAULT_MII_ADDR:
3157 MII address of the PHY to check for the Ethernet link state.
3158
3159 - CONFIG_NS16550_MIN_FUNCTIONS:
3160 Define this if you desire to only have use of the NS16550_init
3161 and NS16550_putc functions for the serial driver located at
3162 drivers/serial/ns16550.c. This option is useful for saving
3163 space for already greatly restricted images, including but not
3164 limited to NAND_SPL configurations.
3165
3166 - CONFIG_DISPLAY_BOARDINFO
3167 Display information about the board that U-Boot is running on
3168 when U-Boot starts up. The board function checkboard() is called
3169 to do this.
3170
3171 - CONFIG_DISPLAY_BOARDINFO_LATE
3172 Similar to the previous option, but display this information
3173 later, once stdio is running and output goes to the LCD, if
3174 present.
3175
3176 - CONFIG_BOARD_SIZE_LIMIT:
3177 Maximum size of the U-Boot image. When defined, the
3178 build system checks that the actual size does not
3179 exceed it.
3180
3181 Low Level (hardware related) configuration options:
3182 ---------------------------------------------------
3183
3184 - CONFIG_SYS_CACHELINE_SIZE:
3185 Cache Line Size of the CPU.
3186
3187 - CONFIG_SYS_CCSRBAR_DEFAULT:
3188 Default (power-on reset) physical address of CCSR on Freescale
3189 PowerPC SOCs.
3190
3191 - CONFIG_SYS_CCSRBAR:
3192 Virtual address of CCSR. On a 32-bit build, this is typically
3193 the same value as CONFIG_SYS_CCSRBAR_DEFAULT.
3194
3195 - CONFIG_SYS_CCSRBAR_PHYS:
3196 Physical address of CCSR. CCSR can be relocated to a new
3197 physical address, if desired. In this case, this macro should
3198 be set to that address. Otherwise, it should be set to the
3199 same value as CONFIG_SYS_CCSRBAR_DEFAULT. For example, CCSR
3200 is typically relocated on 36-bit builds. It is recommended
3201 that this macro be defined via the _HIGH and _LOW macros:
3202
3203 #define CONFIG_SYS_CCSRBAR_PHYS ((CONFIG_SYS_CCSRBAR_PHYS_HIGH
3204 * 1ull) << 32 | CONFIG_SYS_CCSRBAR_PHYS_LOW)
3205
3206 - CONFIG_SYS_CCSRBAR_PHYS_HIGH:
3207 Bits 33-36 of CONFIG_SYS_CCSRBAR_PHYS. This value is typically
3208 either 0 (32-bit build) or 0xF (36-bit build). This macro is
3209 used in assembly code, so it must not contain typecasts or
3210 integer size suffixes (e.g. "ULL").
3211
3212 - CONFIG_SYS_CCSRBAR_PHYS_LOW:
3213 Lower 32-bits of CONFIG_SYS_CCSRBAR_PHYS. This macro is
3214 used in assembly code, so it must not contain typecasts or
3215 integer size suffixes (e.g. "ULL").
3216
3217 - CONFIG_SYS_CCSR_DO_NOT_RELOCATE:
3218 If this macro is defined, then CONFIG_SYS_CCSRBAR_PHYS will be
3219 forced to a value that ensures that CCSR is not relocated.
3220
3221 - Floppy Disk Support:
3222 CONFIG_SYS_FDC_DRIVE_NUMBER
3223
3224 the default drive number (default value 0)
3225
3226 CONFIG_SYS_ISA_IO_STRIDE
3227
3228 defines the spacing between FDC chipset registers
3229 (default value 1)
3230
3231 CONFIG_SYS_ISA_IO_OFFSET
3232
3233 defines the offset of register from address. It
3234 depends on which part of the data bus is connected to
3235 the FDC chipset. (default value 0)
3236
3237 If CONFIG_SYS_ISA_IO_STRIDE CONFIG_SYS_ISA_IO_OFFSET and
3238 CONFIG_SYS_FDC_DRIVE_NUMBER are undefined, they take their
3239 default value.
3240
3241 if CONFIG_SYS_FDC_HW_INIT is defined, then the function
3242 fdc_hw_init() is called at the beginning of the FDC
3243 setup. fdc_hw_init() must be provided by the board
3244 source code. It is used to make hardware-dependent
3245 initializations.
3246
3247 - CONFIG_IDE_AHB:
3248 Most IDE controllers were designed to be connected with PCI
3249 interface. Only few of them were designed for AHB interface.
3250 When software is doing ATA command and data transfer to
3251 IDE devices through IDE-AHB controller, some additional
3252 registers accessing to these kind of IDE-AHB controller
3253 is required.
3254
3255 - CONFIG_SYS_IMMR: Physical address of the Internal Memory.
3256 DO NOT CHANGE unless you know exactly what you're
3257 doing! (11-4) [MPC8xx systems only]
3258
3259 - CONFIG_SYS_INIT_RAM_ADDR:
3260
3261 Start address of memory area that can be used for
3262 initial data and stack; please note that this must be
3263 writable memory that is working WITHOUT special
3264 initialization, i. e. you CANNOT use normal RAM which
3265 will become available only after programming the
3266 memory controller and running certain initialization
3267 sequences.
3268
3269 U-Boot uses the following memory types:
3270 - MPC8xx: IMMR (internal memory of the CPU)
3271
3272 - CONFIG_SYS_GBL_DATA_OFFSET:
3273
3274 Offset of the initial data structure in the memory
3275 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually
3276 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial
3277 data is located at the end of the available space
3278 (sometimes written as (CONFIG_SYS_INIT_RAM_SIZE -
3279 GENERATED_GBL_DATA_SIZE), and the initial stack is just
3280 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR +
3281 CONFIG_SYS_GBL_DATA_OFFSET) downward.
3282
3283 Note:
3284 On the MPC824X (or other systems that use the data
3285 cache for initial memory) the address chosen for
3286 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must
3287 point to an otherwise UNUSED address space between
3288 the top of RAM and the start of the PCI space.
3289
3290 - CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27)
3291
3292 - CONFIG_SYS_OR_TIMING_SDRAM:
3293 SDRAM timing
3294
3295 - CONFIG_SYS_MAMR_PTA:
3296 periodic timer for refresh
3297
3298 - FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM,
3299 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP,
3300 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM,
3301 CONFIG_SYS_BR1_PRELIM:
3302 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
3303
3304 - SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
3305 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM,
3306 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM:
3307 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
3308
3309 - CONFIG_PCI_ENUM_ONLY
3310 Only scan through and get the devices on the buses.
3311 Don't do any setup work, presumably because someone or
3312 something has already done it, and we don't need to do it
3313 a second time. Useful for platforms that are pre-booted
3314 by coreboot or similar.
3315
3316 - CONFIG_PCI_INDIRECT_BRIDGE:
3317 Enable support for indirect PCI bridges.
3318
3319 - CONFIG_SYS_SRIO:
3320 Chip has SRIO or not
3321
3322 - CONFIG_SRIO1:
3323 Board has SRIO 1 port available
3324
3325 - CONFIG_SRIO2:
3326 Board has SRIO 2 port available
3327
3328 - CONFIG_SRIO_PCIE_BOOT_MASTER
3329 Board can support master function for Boot from SRIO and PCIE
3330
3331 - CONFIG_SYS_SRIOn_MEM_VIRT:
3332 Virtual Address of SRIO port 'n' memory region
3333
3334 - CONFIG_SYS_SRIOn_MEM_PHYS:
3335 Physical Address of SRIO port 'n' memory region
3336
3337 - CONFIG_SYS_SRIOn_MEM_SIZE:
3338 Size of SRIO port 'n' memory region
3339
3340 - CONFIG_SYS_NAND_BUSWIDTH_16BIT
3341 Defined to tell the NAND controller that the NAND chip is using
3342 a 16 bit bus.
3343 Not all NAND drivers use this symbol.
3344 Example of drivers that use it:
3345 - drivers/mtd/nand/ndfc.c
3346 - drivers/mtd/nand/mxc_nand.c
3347
3348 - CONFIG_SYS_NDFC_EBC0_CFG
3349 Sets the EBC0_CFG register for the NDFC. If not defined
3350 a default value will be used.
3351
3352 - CONFIG_SPD_EEPROM
3353 Get DDR timing information from an I2C EEPROM. Common
3354 with pluggable memory modules such as SODIMMs
3355
3356 SPD_EEPROM_ADDRESS
3357 I2C address of the SPD EEPROM
3358
3359 - CONFIG_SYS_SPD_BUS_NUM
3360 If SPD EEPROM is on an I2C bus other than the first
3361 one, specify here. Note that the value must resolve
3362 to something your driver can deal with.
3363
3364 - CONFIG_SYS_DDR_RAW_TIMING
3365 Get DDR timing information from other than SPD. Common with
3366 soldered DDR chips onboard without SPD. DDR raw timing
3367 parameters are extracted from datasheet and hard-coded into
3368 header files or board specific files.
3369
3370 - CONFIG_FSL_DDR_INTERACTIVE
3371 Enable interactive DDR debugging. See doc/README.fsl-ddr.
3372
3373 - CONFIG_FSL_DDR_SYNC_REFRESH
3374 Enable sync of refresh for multiple controllers.
3375
3376 - CONFIG_FSL_DDR_BIST
3377 Enable built-in memory test for Freescale DDR controllers.
3378
3379 - CONFIG_SYS_83XX_DDR_USES_CS0
3380 Only for 83xx systems. If specified, then DDR should
3381 be configured using CS0 and CS1 instead of CS2 and CS3.
3382
3383 - CONFIG_RMII
3384 Enable RMII mode for all FECs.
3385 Note that this is a global option, we can't
3386 have one FEC in standard MII mode and another in RMII mode.
3387
3388 - CONFIG_CRC32_VERIFY
3389 Add a verify option to the crc32 command.
3390 The syntax is:
3391
3392 => crc32 -v <address> <count> <crc32>
3393
3394 Where address/count indicate a memory area
3395 and crc32 is the correct crc32 which the
3396 area should have.
3397
3398 - CONFIG_LOOPW
3399 Add the "loopw" memory command. This only takes effect if
3400 the memory commands are activated globally (CONFIG_CMD_MEMORY).
3401
3402 - CONFIG_MX_CYCLIC
3403 Add the "mdc" and "mwc" memory commands. These are cyclic
3404 "md/mw" commands.
3405 Examples:
3406
3407 => mdc.b 10 4 500
3408 This command will print 4 bytes (10,11,12,13) each 500 ms.
3409
3410 => mwc.l 100 12345678 10
3411 This command will write 12345678 to address 100 all 10 ms.
3412
3413 This only takes effect if the memory commands are activated
3414 globally (CONFIG_CMD_MEMORY).
3415
3416 - CONFIG_SKIP_LOWLEVEL_INIT
3417 [ARM, NDS32, MIPS, RISC-V only] If this variable is defined, then certain
3418 low level initializations (like setting up the memory
3419 controller) are omitted and/or U-Boot does not
3420 relocate itself into RAM.
3421
3422 Normally this variable MUST NOT be defined. The only
3423 exception is when U-Boot is loaded (to RAM) by some
3424 other boot loader or by a debugger which performs
3425 these initializations itself.
3426
3427 - CONFIG_SKIP_LOWLEVEL_INIT_ONLY
3428 [ARM926EJ-S only] This allows just the call to lowlevel_init()
3429 to be skipped. The normal CP15 init (such as enabling the
3430 instruction cache) is still performed.
3431
3432 - CONFIG_SPL_BUILD
3433 Modifies the behaviour of start.S when compiling a loader
3434 that is executed before the actual U-Boot. E.g. when
3435 compiling a NAND SPL.
3436
3437 - CONFIG_TPL_BUILD
3438 Modifies the behaviour of start.S when compiling a loader
3439 that is executed after the SPL and before the actual U-Boot.
3440 It is loaded by the SPL.
3441
3442 - CONFIG_SYS_MPC85XX_NO_RESETVEC
3443 Only for 85xx systems. If this variable is specified, the section
3444 .resetvec is not kept and the section .bootpg is placed in the
3445 previous 4k of the .text section.
3446
3447 - CONFIG_ARCH_MAP_SYSMEM
3448 Generally U-Boot (and in particular the md command) uses
3449 effective address. It is therefore not necessary to regard
3450 U-Boot address as virtual addresses that need to be translated
3451 to physical addresses. However, sandbox requires this, since
3452 it maintains its own little RAM buffer which contains all
3453 addressable memory. This option causes some memory accesses
3454 to be mapped through map_sysmem() / unmap_sysmem().
3455
3456 - CONFIG_X86_RESET_VECTOR
3457 If defined, the x86 reset vector code is included. This is not
3458 needed when U-Boot is running from Coreboot.
3459
3460 - CONFIG_SPL_AM33XX_ENABLE_RTC32K_OSC:
3461 Enables the RTC32K OSC on AM33xx based plattforms
3462
3463 - CONFIG_SYS_NAND_NO_SUBPAGE_WRITE
3464 Option to disable subpage write in NAND driver
3465 driver that uses this:
3466 drivers/mtd/nand/davinci_nand.c
3467
3468 Freescale QE/FMAN Firmware Support:
3469 -----------------------------------
3470
3471 The Freescale QUICCEngine (QE) and Frame Manager (FMAN) both support the
3472 loading of "firmware", which is encoded in the QE firmware binary format.
3473 This firmware often needs to be loaded during U-Boot booting, so macros
3474 are used to identify the storage device (NOR flash, SPI, etc) and the address
3475 within that device.
3476
3477 - CONFIG_SYS_FMAN_FW_ADDR
3478 The address in the storage device where the FMAN microcode is located. The
3479 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
3480 is also specified.
3481
3482 - CONFIG_SYS_QE_FW_ADDR
3483 The address in the storage device where the QE microcode is located. The
3484 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
3485 is also specified.
3486
3487 - CONFIG_SYS_QE_FMAN_FW_LENGTH
3488 The maximum possible size of the firmware. The firmware binary format
3489 has a field that specifies the actual size of the firmware, but it
3490 might not be possible to read any part of the firmware unless some
3491 local storage is allocated to hold the entire firmware first.
3492
3493 - CONFIG_SYS_QE_FMAN_FW_IN_NOR
3494 Specifies that QE/FMAN firmware is located in NOR flash, mapped as
3495 normal addressable memory via the LBC. CONFIG_SYS_FMAN_FW_ADDR is the
3496 virtual address in NOR flash.
3497
3498 - CONFIG_SYS_QE_FMAN_FW_IN_NAND
3499 Specifies that QE/FMAN firmware is located in NAND flash.
3500 CONFIG_SYS_FMAN_FW_ADDR is the offset within NAND flash.
3501
3502 - CONFIG_SYS_QE_FMAN_FW_IN_MMC
3503 Specifies that QE/FMAN firmware is located on the primary SD/MMC
3504 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
3505
3506 - CONFIG_SYS_QE_FMAN_FW_IN_REMOTE
3507 Specifies that QE/FMAN firmware is located in the remote (master)
3508 memory space. CONFIG_SYS_FMAN_FW_ADDR is a virtual address which
3509 can be mapped from slave TLB->slave LAW->slave SRIO or PCIE outbound
3510 window->master inbound window->master LAW->the ucode address in
3511 master's memory space.
3512
3513 Freescale Layerscape Management Complex Firmware Support:
3514 ---------------------------------------------------------
3515 The Freescale Layerscape Management Complex (MC) supports the loading of
3516 "firmware".
3517 This firmware often needs to be loaded during U-Boot booting, so macros
3518 are used to identify the storage device (NOR flash, SPI, etc) and the address
3519 within that device.
3520
3521 - CONFIG_FSL_MC_ENET
3522 Enable the MC driver for Layerscape SoCs.
3523
3524 Freescale Layerscape Debug Server Support:
3525 -------------------------------------------
3526 The Freescale Layerscape Debug Server Support supports the loading of
3527 "Debug Server firmware" and triggering SP boot-rom.
3528 This firmware often needs to be loaded during U-Boot booting.
3529
3530 - CONFIG_SYS_MC_RSV_MEM_ALIGN
3531 Define alignment of reserved memory MC requires
3532
3533 Reproducible builds
3534 -------------------
3535
3536 In order to achieve reproducible builds, timestamps used in the U-Boot build
3537 process have to be set to a fixed value.
3538
3539 This is done using the SOURCE_DATE_EPOCH environment variable.
3540 SOURCE_DATE_EPOCH is to be set on the build host's shell, not as a configuration
3541 option for U-Boot or an environment variable in U-Boot.
3542
3543 SOURCE_DATE_EPOCH should be set to a number of seconds since the epoch, in UTC.
3544
3545 Building the Software:
3546 ======================
3547
3548 Building U-Boot has been tested in several native build environments
3549 and in many different cross environments. Of course we cannot support
3550 all possibly existing versions of cross development tools in all
3551 (potentially obsolete) versions. In case of tool chain problems we
3552 recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK)
3553 which is extensively used to build and test U-Boot.
3554
3555 If you are not using a native environment, it is assumed that you
3556 have GNU cross compiling tools available in your path. In this case,
3557 you must set the environment variable CROSS_COMPILE in your shell.
3558 Note that no changes to the Makefile or any other source files are
3559 necessary. For example using the ELDK on a 4xx CPU, please enter:
3560
3561 $ CROSS_COMPILE=ppc_4xx-
3562 $ export CROSS_COMPILE
3563
3564 Note: If you wish to generate Windows versions of the utilities in
3565 the tools directory you can use the MinGW toolchain
3566 (http://www.mingw.org). Set your HOST tools to the MinGW
3567 toolchain and execute 'make tools'. For example:
3568
3569 $ make HOSTCC=i586-mingw32msvc-gcc HOSTSTRIP=i586-mingw32msvc-strip tools
3570
3571 Binaries such as tools/mkimage.exe will be created which can
3572 be executed on computers running Windows.
3573
3574 U-Boot is intended to be simple to build. After installing the
3575 sources you must configure U-Boot for one specific board type. This
3576 is done by typing:
3577
3578 make NAME_defconfig
3579
3580 where "NAME_defconfig" is the name of one of the existing configu-
3581 rations; see boards.cfg for supported names.
3582
3583 Note: for some board special configuration names may exist; check if
3584 additional information is available from the board vendor; for
3585 instance, the TQM823L systems are available without (standard)
3586 or with LCD support. You can select such additional "features"
3587 when choosing the configuration, i. e.
3588
3589 make TQM823L_defconfig
3590 - will configure for a plain TQM823L, i. e. no LCD support
3591
3592 make TQM823L_LCD_defconfig
3593 - will configure for a TQM823L with U-Boot console on LCD
3594
3595 etc.
3596
3597
3598 Finally, type "make all", and you should get some working U-Boot
3599 images ready for download to / installation on your system:
3600
3601 - "u-boot.bin" is a raw binary image
3602 - "u-boot" is an image in ELF binary format
3603 - "u-boot.srec" is in Motorola S-Record format
3604
3605 By default the build is performed locally and the objects are saved
3606 in the source directory. One of the two methods can be used to change
3607 this behavior and build U-Boot to some external directory:
3608
3609 1. Add O= to the make command line invocations:
3610
3611 make O=/tmp/build distclean
3612 make O=/tmp/build NAME_defconfig
3613 make O=/tmp/build all
3614
3615 2. Set environment variable KBUILD_OUTPUT to point to the desired location:
3616
3617 export KBUILD_OUTPUT=/tmp/build
3618 make distclean
3619 make NAME_defconfig
3620 make all
3621
3622 Note that the command line "O=" setting overrides the KBUILD_OUTPUT environment
3623 variable.
3624
3625 User specific CPPFLAGS, AFLAGS and CFLAGS can be passed to the compiler by
3626 setting the according environment variables KCPPFLAGS, KAFLAGS and KCFLAGS.
3627 For example to treat all compiler warnings as errors:
3628
3629 make KCFLAGS=-Werror
3630
3631 Please be aware that the Makefiles assume you are using GNU make, so
3632 for instance on NetBSD you might need to use "gmake" instead of
3633 native "make".
3634
3635
3636 If the system board that you have is not listed, then you will need
3637 to port U-Boot to your hardware platform. To do this, follow these
3638 steps:
3639
3640 1. Create a new directory to hold your board specific code. Add any
3641 files you need. In your board directory, you will need at least
3642 the "Makefile" and a "<board>.c".
3643 2. Create a new configuration file "include/configs/<board>.h" for
3644 your board.
3645 3. If you're porting U-Boot to a new CPU, then also create a new
3646 directory to hold your CPU specific code. Add any files you need.
3647 4. Run "make <board>_defconfig" with your new name.
3648 5. Type "make", and you should get a working "u-boot.srec" file
3649 to be installed on your target system.
3650 6. Debug and solve any problems that might arise.
3651 [Of course, this last step is much harder than it sounds.]
3652
3653
3654 Testing of U-Boot Modifications, Ports to New Hardware, etc.:
3655 ==============================================================
3656
3657 If you have modified U-Boot sources (for instance added a new board
3658 or support for new devices, a new CPU, etc.) you are expected to
3659 provide feedback to the other developers. The feedback normally takes
3660 the form of a "patch", i. e. a context diff against a certain (latest
3661 official or latest in the git repository) version of U-Boot sources.
3662
3663 But before you submit such a patch, please verify that your modifi-
3664 cation did not break existing code. At least make sure that *ALL* of
3665 the supported boards compile WITHOUT ANY compiler warnings. To do so,
3666 just run the buildman script (tools/buildman/buildman), which will
3667 configure and build U-Boot for ALL supported system. Be warned, this
3668 will take a while. Please see the buildman README, or run 'buildman -H'
3669 for documentation.
3670
3671
3672 See also "U-Boot Porting Guide" below.
3673
3674
3675 Monitor Commands - Overview:
3676 ============================
3677
3678 go - start application at address 'addr'
3679 run - run commands in an environment variable
3680 bootm - boot application image from memory
3681 bootp - boot image via network using BootP/TFTP protocol
3682 bootz - boot zImage from memory
3683 tftpboot- boot image via network using TFTP protocol
3684 and env variables "ipaddr" and "serverip"
3685 (and eventually "gatewayip")
3686 tftpput - upload a file via network using TFTP protocol
3687 rarpboot- boot image via network using RARP/TFTP protocol
3688 diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
3689 loads - load S-Record file over serial line
3690 loadb - load binary file over serial line (kermit mode)
3691 md - memory display
3692 mm - memory modify (auto-incrementing)
3693 nm - memory modify (constant address)
3694 mw - memory write (fill)
3695 cp - memory copy
3696 cmp - memory compare
3697 crc32 - checksum calculation
3698 i2c - I2C sub-system
3699 sspi - SPI utility commands
3700 base - print or set address offset
3701 printenv- print environment variables
3702 setenv - set environment variables
3703 saveenv - save environment variables to persistent storage
3704 protect - enable or disable FLASH write protection
3705 erase - erase FLASH memory
3706 flinfo - print FLASH memory information
3707 nand - NAND memory operations (see doc/README.nand)
3708 bdinfo - print Board Info structure
3709 iminfo - print header information for application image
3710 coninfo - print console devices and informations
3711 ide - IDE sub-system
3712 loop - infinite loop on address range
3713 loopw - infinite write loop on address range
3714 mtest - simple RAM test
3715 icache - enable or disable instruction cache
3716 dcache - enable or disable data cache
3717 reset - Perform RESET of the CPU
3718 echo - echo args to console
3719 version - print monitor version
3720 help - print online help
3721 ? - alias for 'help'
3722
3723
3724 Monitor Commands - Detailed Description:
3725 ========================================
3726
3727 TODO.
3728
3729 For now: just type "help <command>".
3730
3731
3732 Environment Variables:
3733 ======================
3734
3735 U-Boot supports user configuration using Environment Variables which
3736 can be made persistent by saving to Flash memory.
3737
3738 Environment Variables are set using "setenv", printed using
3739 "printenv", and saved to Flash using "saveenv". Using "setenv"
3740 without a value can be used to delete a variable from the
3741 environment. As long as you don't save the environment you are
3742 working with an in-memory copy. In case the Flash area containing the
3743 environment is erased by accident, a default environment is provided.
3744
3745 Some configuration options can be set using Environment Variables.
3746
3747 List of environment variables (most likely not complete):
3748
3749 baudrate - see CONFIG_BAUDRATE
3750
3751 bootdelay - see CONFIG_BOOTDELAY
3752
3753 bootcmd - see CONFIG_BOOTCOMMAND
3754
3755 bootargs - Boot arguments when booting an RTOS image
3756
3757 bootfile - Name of the image to load with TFTP
3758
3759 bootm_low - Memory range available for image processing in the bootm
3760 command can be restricted. This variable is given as
3761 a hexadecimal number and defines lowest address allowed
3762 for use by the bootm command. See also "bootm_size"
3763 environment variable. Address defined by "bootm_low" is
3764 also the base of the initial memory mapping for the Linux
3765 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ and
3766 bootm_mapsize.
3767
3768 bootm_mapsize - Size of the initial memory mapping for the Linux kernel.
3769 This variable is given as a hexadecimal number and it
3770 defines the size of the memory region starting at base
3771 address bootm_low that is accessible by the Linux kernel
3772 during early boot. If unset, CONFIG_SYS_BOOTMAPSZ is used
3773 as the default value if it is defined, and bootm_size is
3774 used otherwise.
3775
3776 bootm_size - Memory range available for image processing in the bootm
3777 command can be restricted. This variable is given as
3778 a hexadecimal number and defines the size of the region
3779 allowed for use by the bootm command. See also "bootm_low"
3780 environment variable.
3781
3782 updatefile - Location of the software update file on a TFTP server, used
3783 by the automatic software update feature. Please refer to
3784 documentation in doc/README.update for more details.
3785
3786 autoload - if set to "no" (any string beginning with 'n'),
3787 "bootp" will just load perform a lookup of the
3788 configuration from the BOOTP server, but not try to
3789 load any image using TFTP
3790
3791 autostart - if set to "yes", an image loaded using the "bootp",
3792 "rarpboot", "tftpboot" or "diskboot" commands will
3793 be automatically started (by internally calling
3794 "bootm")
3795
3796 If set to "no", a standalone image passed to the
3797 "bootm" command will be copied to the load address
3798 (and eventually uncompressed), but NOT be started.
3799 This can be used to load and uncompress arbitrary
3800 data.
3801
3802 fdt_high - if set this restricts the maximum address that the
3803 flattened device tree will be copied into upon boot.
3804 For example, if you have a system with 1 GB memory
3805 at physical address 0x10000000, while Linux kernel
3806 only recognizes the first 704 MB as low memory, you
3807 may need to set fdt_high as 0x3C000000 to have the
3808 device tree blob be copied to the maximum address
3809 of the 704 MB low memory, so that Linux kernel can
3810 access it during the boot procedure.
3811
3812 If this is set to the special value 0xFFFFFFFF then
3813 the fdt will not be copied at all on boot. For this
3814 to work it must reside in writable memory, have
3815 sufficient padding on the end of it for u-boot to
3816 add the information it needs into it, and the memory
3817 must be accessible by the kernel.
3818
3819 fdtcontroladdr- if set this is the address of the control flattened
3820 device tree used by U-Boot when CONFIG_OF_CONTROL is
3821 defined.
3822
3823 i2cfast - (PPC405GP|PPC405EP only)
3824 if set to 'y' configures Linux I2C driver for fast
3825 mode (400kHZ). This environment variable is used in
3826 initialization code. So, for changes to be effective
3827 it must be saved and board must be reset.
3828
3829 initrd_high - restrict positioning of initrd images:
3830 If this variable is not set, initrd images will be
3831 copied to the highest possible address in RAM; this
3832 is usually what you want since it allows for
3833 maximum initrd size. If for some reason you want to
3834 make sure that the initrd image is loaded below the
3835 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment
3836 variable to a value of "no" or "off" or "0".
3837 Alternatively, you can set it to a maximum upper
3838 address to use (U-Boot will still check that it
3839 does not overwrite the U-Boot stack and data).
3840
3841 For instance, when you have a system with 16 MB
3842 RAM, and want to reserve 4 MB from use by Linux,
3843 you can do this by adding "mem=12M" to the value of
3844 the "bootargs" variable. However, now you must make
3845 sure that the initrd image is placed in the first
3846 12 MB as well - this can be done with
3847
3848 setenv initrd_high 00c00000
3849
3850 If you set initrd_high to 0xFFFFFFFF, this is an
3851 indication to U-Boot that all addresses are legal
3852 for the Linux kernel, including addresses in flash
3853 memory. In this case U-Boot will NOT COPY the
3854 ramdisk at all. This may be useful to reduce the
3855 boot time on your system, but requires that this
3856 feature is supported by your Linux kernel.
3857
3858 ipaddr - IP address; needed for tftpboot command
3859
3860 loadaddr - Default load address for commands like "bootp",
3861 "rarpboot", "tftpboot", "loadb" or "diskboot"
3862
3863 loads_echo - see CONFIG_LOADS_ECHO
3864
3865 serverip - TFTP server IP address; needed for tftpboot command
3866
3867 bootretry - see CONFIG_BOOT_RETRY_TIME
3868
3869 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
3870
3871 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
3872
3873 ethprime - controls which interface is used first.
3874
3875 ethact - controls which interface is currently active.
3876 For example you can do the following
3877
3878 => setenv ethact FEC
3879 => ping 192.168.0.1 # traffic sent on FEC
3880 => setenv ethact SCC
3881 => ping 10.0.0.1 # traffic sent on SCC
3882
3883 ethrotate - When set to "no" U-Boot does not go through all
3884 available network interfaces.
3885 It just stays at the currently selected interface.
3886
3887 netretry - When set to "no" each network operation will
3888 either succeed or fail without retrying.
3889 When set to "once" the network operation will
3890 fail when all the available network interfaces
3891 are tried once without success.
3892 Useful on scripts which control the retry operation
3893 themselves.
3894
3895 npe_ucode - set load address for the NPE microcode
3896
3897 silent_linux - If set then Linux will be told to boot silently, by
3898 changing the console to be empty. If "yes" it will be
3899 made silent. If "no" it will not be made silent. If
3900 unset, then it will be made silent if the U-Boot console
3901 is silent.
3902
3903 tftpsrcp - If this is set, the value is used for TFTP's
3904 UDP source port.
3905
3906 tftpdstp - If this is set, the value is used for TFTP's UDP
3907 destination port instead of the Well Know Port 69.
3908
3909 tftpblocksize - Block size to use for TFTP transfers; if not set,
3910 we use the TFTP server's default block size
3911
3912 tftptimeout - Retransmission timeout for TFTP packets (in milli-
3913 seconds, minimum value is 1000 = 1 second). Defines
3914 when a packet is considered to be lost so it has to
3915 be retransmitted. The default is 5000 = 5 seconds.
3916 Lowering this value may make downloads succeed
3917 faster in networks with high packet loss rates or
3918 with unreliable TFTP servers.
3919
3920 tftptimeoutcountmax - maximum count of TFTP timeouts (no
3921 unit, minimum value = 0). Defines how many timeouts
3922 can happen during a single file transfer before that
3923 transfer is aborted. The default is 10, and 0 means
3924 'no timeouts allowed'. Increasing this value may help
3925 downloads succeed with high packet loss rates, or with
3926 unreliable TFTP servers or client hardware.
3927
3928 vlan - When set to a value < 4095 the traffic over
3929 Ethernet is encapsulated/received over 802.1q
3930 VLAN tagged frames.
3931
3932 bootpretryperiod - Period during which BOOTP/DHCP sends retries.
3933 Unsigned value, in milliseconds. If not set, the period will
3934 be either the default (28000), or a value based on
3935 CONFIG_NET_RETRY_COUNT, if defined. This value has
3936 precedence over the valu based on CONFIG_NET_RETRY_COUNT.
3937
3938 The following image location variables contain the location of images
3939 used in booting. The "Image" column gives the role of the image and is
3940 not an environment variable name. The other columns are environment
3941 variable names. "File Name" gives the name of the file on a TFTP
3942 server, "RAM Address" gives the location in RAM the image will be
3943 loaded to, and "Flash Location" gives the image's address in NOR
3944 flash or offset in NAND flash.
3945
3946 *Note* - these variables don't have to be defined for all boards, some
3947 boards currently use other variables for these purposes, and some
3948 boards use these variables for other purposes.
3949
3950 Image File Name RAM Address Flash Location
3951 ----- --------- ----------- --------------
3952 u-boot u-boot u-boot_addr_r u-boot_addr
3953 Linux kernel bootfile kernel_addr_r kernel_addr
3954 device tree blob fdtfile fdt_addr_r fdt_addr
3955 ramdisk ramdiskfile ramdisk_addr_r ramdisk_addr
3956
3957 The following environment variables may be used and automatically
3958 updated by the network boot commands ("bootp" and "rarpboot"),
3959 depending the information provided by your boot server:
3960
3961 bootfile - see above
3962 dnsip - IP address of your Domain Name Server
3963 dnsip2 - IP address of your secondary Domain Name Server
3964 gatewayip - IP address of the Gateway (Router) to use
3965 hostname - Target hostname
3966 ipaddr - see above
3967 netmask - Subnet Mask
3968 rootpath - Pathname of the root filesystem on the NFS server
3969 serverip - see above
3970
3971
3972 There are two special Environment Variables:
3973
3974 serial# - contains hardware identification information such
3975 as type string and/or serial number
3976 ethaddr - Ethernet address
3977
3978 These variables can be set only once (usually during manufacturing of
3979 the board). U-Boot refuses to delete or overwrite these variables
3980 once they have been set once.
3981
3982
3983 Further special Environment Variables:
3984
3985 ver - Contains the U-Boot version string as printed
3986 with the "version" command. This variable is
3987 readonly (see CONFIG_VERSION_VARIABLE).
3988
3989
3990 Please note that changes to some configuration parameters may take
3991 only effect after the next boot (yes, that's just like Windoze :-).
3992
3993
3994 Callback functions for environment variables:
3995 ---------------------------------------------
3996
3997 For some environment variables, the behavior of u-boot needs to change
3998 when their values are changed. This functionality allows functions to
3999 be associated with arbitrary variables. On creation, overwrite, or
4000 deletion, the callback will provide the opportunity for some side
4001 effect to happen or for the change to be rejected.
4002
4003 The callbacks are named and associated with a function using the
4004 U_BOOT_ENV_CALLBACK macro in your board or driver code.
4005
4006 These callbacks are associated with variables in one of two ways. The
4007 static list can be added to by defining CONFIG_ENV_CALLBACK_LIST_STATIC
4008 in the board configuration to a string that defines a list of
4009 associations. The list must be in the following format:
4010
4011 entry = variable_name[:callback_name]
4012 list = entry[,list]
4013
4014 If the callback name is not specified, then the callback is deleted.
4015 Spaces are also allowed anywhere in the list.
4016
4017 Callbacks can also be associated by defining the ".callbacks" variable
4018 with the same list format above. Any association in ".callbacks" will
4019 override any association in the static list. You can define
4020 CONFIG_ENV_CALLBACK_LIST_DEFAULT to a list (string) to define the
4021 ".callbacks" environment variable in the default or embedded environment.
4022
4023 If CONFIG_REGEX is defined, the variable_name above is evaluated as a
4024 regular expression. This allows multiple variables to be connected to
4025 the same callback without explicitly listing them all out.
4026
4027
4028 Command Line Parsing:
4029 =====================
4030
4031 There are two different command line parsers available with U-Boot:
4032 the old "simple" one, and the much more powerful "hush" shell:
4033
4034 Old, simple command line parser:
4035 --------------------------------
4036
4037 - supports environment variables (through setenv / saveenv commands)
4038 - several commands on one line, separated by ';'
4039 - variable substitution using "... ${name} ..." syntax
4040 - special characters ('$', ';') can be escaped by prefixing with '\',
4041 for example:
4042 setenv bootcmd bootm \${address}
4043 - You can also escape text by enclosing in single apostrophes, for example:
4044 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
4045
4046 Hush shell:
4047 -----------
4048
4049 - similar to Bourne shell, with control structures like
4050 if...then...else...fi, for...do...done; while...do...done,
4051 until...do...done, ...
4052 - supports environment ("global") variables (through setenv / saveenv
4053 commands) and local shell variables (through standard shell syntax
4054 "name=value"); only environment variables can be used with "run"
4055 command
4056
4057 General rules:
4058 --------------
4059
4060 (1) If a command line (or an environment variable executed by a "run"
4061 command) contains several commands separated by semicolon, and
4062 one of these commands fails, then the remaining commands will be
4063 executed anyway.
4064
4065 (2) If you execute several variables with one call to run (i. e.
4066 calling run with a list of variables as arguments), any failing
4067 command will cause "run" to terminate, i. e. the remaining
4068 variables are not executed.
4069
4070 Note for Redundant Ethernet Interfaces:
4071 =======================================
4072
4073 Some boards come with redundant Ethernet interfaces; U-Boot supports
4074 such configurations and is capable of automatic selection of a
4075 "working" interface when needed. MAC assignment works as follows:
4076
4077 Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
4078 MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
4079 "eth1addr" (=>eth1), "eth2addr", ...
4080
4081 If the network interface stores some valid MAC address (for instance
4082 in SROM), this is used as default address if there is NO correspon-
4083 ding setting in the environment; if the corresponding environment
4084 variable is set, this overrides the settings in the card; that means:
4085
4086 o If the SROM has a valid MAC address, and there is no address in the
4087 environment, the SROM's address is used.
4088
4089 o If there is no valid address in the SROM, and a definition in the
4090 environment exists, then the value from the environment variable is
4091 used.
4092
4093 o If both the SROM and the environment contain a MAC address, and
4094 both addresses are the same, this MAC address is used.
4095
4096 o If both the SROM and the environment contain a MAC address, and the
4097 addresses differ, the value from the environment is used and a
4098 warning is printed.
4099
4100 o If neither SROM nor the environment contain a MAC address, an error
4101 is raised. If CONFIG_NET_RANDOM_ETHADDR is defined, then in this case
4102 a random, locally-assigned MAC is used.
4103
4104 If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses
4105 will be programmed into hardware as part of the initialization process. This
4106 may be skipped by setting the appropriate 'ethmacskip' environment variable.
4107 The naming convention is as follows:
4108 "ethmacskip" (=>eth0), "eth1macskip" (=>eth1) etc.
4109
4110 Image Formats:
4111 ==============
4112
4113 U-Boot is capable of booting (and performing other auxiliary operations on)
4114 images in two formats:
4115
4116 New uImage format (FIT)
4117 -----------------------
4118
4119 Flexible and powerful format based on Flattened Image Tree -- FIT (similar
4120 to Flattened Device Tree). It allows the use of images with multiple
4121 components (several kernels, ramdisks, etc.), with contents protected by
4122 SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory.
4123
4124
4125 Old uImage format
4126 -----------------
4127
4128 Old image format is based on binary files which can be basically anything,
4129 preceded by a special header; see the definitions in include/image.h for
4130 details; basically, the header defines the following image properties:
4131
4132 * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
4133 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
4134 LynxOS, pSOS, QNX, RTEMS, INTEGRITY;
4135 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS,
4136 INTEGRITY).
4137 * Target CPU Architecture (Provisions for Alpha, ARM, Intel x86,
4138 IA64, MIPS, NDS32, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
4139 Currently supported: ARM, Intel x86, MIPS, NDS32, Nios II, PowerPC).
4140 * Compression Type (uncompressed, gzip, bzip2)
4141 * Load Address
4142 * Entry Point
4143 * Image Name
4144 * Image Timestamp
4145
4146 The header is marked by a special Magic Number, and both the header
4147 and the data portions of the image are secured against corruption by
4148 CRC32 checksums.
4149
4150
4151 Linux Support:
4152 ==============
4153
4154 Although U-Boot should support any OS or standalone application
4155 easily, the main focus has always been on Linux during the design of
4156 U-Boot.
4157
4158 U-Boot includes many features that so far have been part of some
4159 special "boot loader" code within the Linux kernel. Also, any
4160 "initrd" images to be used are no longer part of one big Linux image;
4161 instead, kernel and "initrd" are separate images. This implementation
4162 serves several purposes:
4163
4164 - the same features can be used for other OS or standalone
4165 applications (for instance: using compressed images to reduce the
4166 Flash memory footprint)
4167
4168 - it becomes much easier to port new Linux kernel versions because
4169 lots of low-level, hardware dependent stuff are done by U-Boot
4170
4171 - the same Linux kernel image can now be used with different "initrd"
4172 images; of course this also means that different kernel images can
4173 be run with the same "initrd". This makes testing easier (you don't
4174 have to build a new "zImage.initrd" Linux image when you just
4175 change a file in your "initrd"). Also, a field-upgrade of the
4176 software is easier now.
4177
4178
4179 Linux HOWTO:
4180 ============
4181
4182 Porting Linux to U-Boot based systems:
4183 ---------------------------------------
4184
4185 U-Boot cannot save you from doing all the necessary modifications to
4186 configure the Linux device drivers for use with your target hardware
4187 (no, we don't intend to provide a full virtual machine interface to
4188 Linux :-).
4189
4190 But now you can ignore ALL boot loader code (in arch/powerpc/mbxboot).
4191
4192 Just make sure your machine specific header file (for instance
4193 include/asm-ppc/tqm8xx.h) includes the same definition of the Board
4194 Information structure as we define in include/asm-<arch>/u-boot.h,
4195 and make sure that your definition of IMAP_ADDR uses the same value
4196 as your U-Boot configuration in CONFIG_SYS_IMMR.
4197
4198 Note that U-Boot now has a driver model, a unified model for drivers.
4199 If you are adding a new driver, plumb it into driver model. If there
4200 is no uclass available, you are encouraged to create one. See
4201 doc/driver-model.
4202
4203
4204 Configuring the Linux kernel:
4205 -----------------------------
4206
4207 No specific requirements for U-Boot. Make sure you have some root
4208 device (initial ramdisk, NFS) for your target system.
4209
4210
4211 Building a Linux Image:
4212 -----------------------
4213
4214 With U-Boot, "normal" build targets like "zImage" or "bzImage" are
4215 not used. If you use recent kernel source, a new build target
4216 "uImage" will exist which automatically builds an image usable by
4217 U-Boot. Most older kernels also have support for a "pImage" target,
4218 which was introduced for our predecessor project PPCBoot and uses a
4219 100% compatible format.
4220
4221 Example:
4222
4223 make TQM850L_defconfig
4224 make oldconfig
4225 make dep
4226 make uImage
4227
4228 The "uImage" build target uses a special tool (in 'tools/mkimage') to
4229 encapsulate a compressed Linux kernel image with header information,
4230 CRC32 checksum etc. for use with U-Boot. This is what we are doing:
4231
4232 * build a standard "vmlinux" kernel image (in ELF binary format):
4233
4234 * convert the kernel into a raw binary image:
4235
4236 ${CROSS_COMPILE}-objcopy -O binary \
4237 -R .note -R .comment \
4238 -S vmlinux linux.bin
4239
4240 * compress the binary image:
4241
4242 gzip -9 linux.bin
4243
4244 * package compressed binary image for U-Boot:
4245
4246 mkimage -A ppc -O linux -T kernel -C gzip \
4247 -a 0 -e 0 -n "Linux Kernel Image" \
4248 -d linux.bin.gz uImage
4249
4250
4251 The "mkimage" tool can also be used to create ramdisk images for use
4252 with U-Boot, either separated from the Linux kernel image, or
4253 combined into one file. "mkimage" encapsulates the images with a 64
4254 byte header containing information about target architecture,
4255 operating system, image type, compression method, entry points, time
4256 stamp, CRC32 checksums, etc.
4257
4258 "mkimage" can be called in two ways: to verify existing images and
4259 print the header information, or to build new images.
4260
4261 In the first form (with "-l" option) mkimage lists the information
4262 contained in the header of an existing U-Boot image; this includes
4263 checksum verification:
4264
4265 tools/mkimage -l image
4266 -l ==> list image header information
4267
4268 The second form (with "-d" option) is used to build a U-Boot image
4269 from a "data file" which is used as image payload:
4270
4271 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
4272 -n name -d data_file image
4273 -A ==> set architecture to 'arch'
4274 -O ==> set operating system to 'os'
4275 -T ==> set image type to 'type'
4276 -C ==> set compression type 'comp'
4277 -a ==> set load address to 'addr' (hex)
4278 -e ==> set entry point to 'ep' (hex)
4279 -n ==> set image name to 'name'
4280 -d ==> use image data from 'datafile'
4281
4282 Right now, all Linux kernels for PowerPC systems use the same load
4283 address (0x00000000), but the entry point address depends on the
4284 kernel version:
4285
4286 - 2.2.x kernels have the entry point at 0x0000000C,
4287 - 2.3.x and later kernels have the entry point at 0x00000000.
4288
4289 So a typical call to build a U-Boot image would read:
4290
4291 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
4292 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
4293 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz \
4294 > examples/uImage.TQM850L
4295 Image Name: 2.4.4 kernel for TQM850L
4296 Created: Wed Jul 19 02:34:59 2000
4297 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4298 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
4299 Load Address: 0x00000000
4300 Entry Point: 0x00000000
4301
4302 To verify the contents of the image (or check for corruption):
4303
4304 -> tools/mkimage -l examples/uImage.TQM850L
4305 Image Name: 2.4.4 kernel for TQM850L
4306 Created: Wed Jul 19 02:34:59 2000
4307 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4308 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
4309 Load Address: 0x00000000
4310 Entry Point: 0x00000000
4311
4312 NOTE: for embedded systems where boot time is critical you can trade
4313 speed for memory and install an UNCOMPRESSED image instead: this
4314 needs more space in Flash, but boots much faster since it does not
4315 need to be uncompressed:
4316
4317 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz
4318 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
4319 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
4320 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux \
4321 > examples/uImage.TQM850L-uncompressed
4322 Image Name: 2.4.4 kernel for TQM850L
4323 Created: Wed Jul 19 02:34:59 2000
4324 Image Type: PowerPC Linux Kernel Image (uncompressed)
4325 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
4326 Load Address: 0x00000000
4327 Entry Point: 0x00000000
4328
4329
4330 Similar you can build U-Boot images from a 'ramdisk.image.gz' file
4331 when your kernel is intended to use an initial ramdisk:
4332
4333 -> tools/mkimage -n 'Simple Ramdisk Image' \
4334 > -A ppc -O linux -T ramdisk -C gzip \
4335 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
4336 Image Name: Simple Ramdisk Image
4337 Created: Wed Jan 12 14:01:50 2000
4338 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
4339 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
4340 Load Address: 0x00000000
4341 Entry Point: 0x00000000
4342
4343 The "dumpimage" is a tool to disassemble images built by mkimage. Its "-i"
4344 option performs the converse operation of the mkimage's second form (the "-d"
4345 option). Given an image built by mkimage, the dumpimage extracts a "data file"
4346 from the image:
4347
4348 tools/dumpimage -i image -T type -p position data_file
4349 -i ==> extract from the 'image' a specific 'data_file'
4350 -T ==> set image type to 'type'
4351 -p ==> 'position' (starting at 0) of the 'data_file' inside the 'image'
4352
4353
4354 Installing a Linux Image:
4355 -------------------------
4356
4357 To downloading a U-Boot image over the serial (console) interface,
4358 you must convert the image to S-Record format:
4359
4360 objcopy -I binary -O srec examples/image examples/image.srec
4361
4362 The 'objcopy' does not understand the information in the U-Boot
4363 image header, so the resulting S-Record file will be relative to
4364 address 0x00000000. To load it to a given address, you need to
4365 specify the target address as 'offset' parameter with the 'loads'
4366 command.
4367
4368 Example: install the image to address 0x40100000 (which on the
4369 TQM8xxL is in the first Flash bank):
4370
4371 => erase 40100000 401FFFFF
4372
4373 .......... done
4374 Erased 8 sectors
4375
4376 => loads 40100000
4377 ## Ready for S-Record download ...
4378 ~>examples/image.srec
4379 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
4380 ...
4381 15989 15990 15991 15992
4382 [file transfer complete]
4383 [connected]
4384 ## Start Addr = 0x00000000
4385
4386
4387 You can check the success of the download using the 'iminfo' command;
4388 this includes a checksum verification so you can be sure no data
4389 corruption happened:
4390
4391 => imi 40100000
4392
4393 ## Checking Image at 40100000 ...
4394 Image Name: 2.2.13 for initrd on TQM850L
4395 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4396 Data Size: 335725 Bytes = 327 kB = 0 MB
4397 Load Address: 00000000
4398 Entry Point: 0000000c
4399 Verifying Checksum ... OK
4400
4401
4402 Boot Linux:
4403 -----------
4404
4405 The "bootm" command is used to boot an application that is stored in
4406 memory (RAM or Flash). In case of a Linux kernel image, the contents
4407 of the "bootargs" environment variable is passed to the kernel as
4408 parameters. You can check and modify this variable using the
4409 "printenv" and "setenv" commands:
4410
4411
4412 => printenv bootargs
4413 bootargs=root=/dev/ram
4414
4415 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
4416
4417 => printenv bootargs
4418 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
4419
4420 => bootm 40020000
4421 ## Booting Linux kernel at 40020000 ...
4422 Image Name: 2.2.13 for NFS on TQM850L
4423 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4424 Data Size: 381681 Bytes = 372 kB = 0 MB
4425 Load Address: 00000000
4426 Entry Point: 0000000c
4427 Verifying Checksum ... OK
4428 Uncompressing Kernel Image ... OK
4429 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
4430 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
4431 time_init: decrementer frequency = 187500000/60
4432 Calibrating delay loop... 49.77 BogoMIPS
4433 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
4434 ...
4435
4436 If you want to boot a Linux kernel with initial RAM disk, you pass
4437 the memory addresses of both the kernel and the initrd image (PPBCOOT
4438 format!) to the "bootm" command:
4439
4440 => imi 40100000 40200000
4441
4442 ## Checking Image at 40100000 ...
4443 Image Name: 2.2.13 for initrd on TQM850L
4444 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4445 Data Size: 335725 Bytes = 327 kB = 0 MB
4446 Load Address: 00000000
4447 Entry Point: 0000000c
4448 Verifying Checksum ... OK
4449
4450 ## Checking Image at 40200000 ...
4451 Image Name: Simple Ramdisk Image
4452 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
4453 Data Size: 566530 Bytes = 553 kB = 0 MB
4454 Load Address: 00000000
4455 Entry Point: 00000000
4456 Verifying Checksum ... OK
4457
4458 => bootm 40100000 40200000
4459 ## Booting Linux kernel at 40100000 ...
4460 Image Name: 2.2.13 for initrd on TQM850L
4461 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4462 Data Size: 335725 Bytes = 327 kB = 0 MB
4463 Load Address: 00000000
4464 Entry Point: 0000000c
4465 Verifying Checksum ... OK
4466 Uncompressing Kernel Image ... OK
4467 ## Loading RAMDisk Image at 40200000 ...
4468 Image Name: Simple Ramdisk Image
4469 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
4470 Data Size: 566530 Bytes = 553 kB = 0 MB
4471 Load Address: 00000000
4472 Entry Point: 00000000
4473 Verifying Checksum ... OK
4474 Loading Ramdisk ... OK
4475 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
4476 Boot arguments: root=/dev/ram
4477 time_init: decrementer frequency = 187500000/60
4478 Calibrating delay loop... 49.77 BogoMIPS
4479 ...
4480 RAMDISK: Compressed image found at block 0
4481 VFS: Mounted root (ext2 filesystem).
4482
4483 bash#
4484
4485 Boot Linux and pass a flat device tree:
4486 -----------
4487
4488 First, U-Boot must be compiled with the appropriate defines. See the section
4489 titled "Linux Kernel Interface" above for a more in depth explanation. The
4490 following is an example of how to start a kernel and pass an updated
4491 flat device tree:
4492
4493 => print oftaddr
4494 oftaddr=0x300000
4495 => print oft
4496 oft=oftrees/mpc8540ads.dtb
4497 => tftp $oftaddr $oft
4498 Speed: 1000, full duplex
4499 Using TSEC0 device
4500 TFTP from server 192.168.1.1; our IP address is 192.168.1.101
4501 Filename 'oftrees/mpc8540ads.dtb'.
4502 Load address: 0x300000
4503 Loading: #
4504 done
4505 Bytes transferred = 4106 (100a hex)
4506 => tftp $loadaddr $bootfile
4507 Speed: 1000, full duplex
4508 Using TSEC0 device
4509 TFTP from server 192.168.1.1; our IP address is 192.168.1.2
4510 Filename 'uImage'.
4511 Load address: 0x200000
4512 Loading:############
4513 done
4514 Bytes transferred = 1029407 (fb51f hex)
4515 => print loadaddr
4516 loadaddr=200000
4517 => print oftaddr
4518 oftaddr=0x300000
4519 => bootm $loadaddr - $oftaddr
4520 ## Booting image at 00200000 ...
4521 Image Name: Linux-2.6.17-dirty
4522 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4523 Data Size: 1029343 Bytes = 1005.2 kB
4524 Load Address: 00000000
4525 Entry Point: 00000000
4526 Verifying Checksum ... OK
4527 Uncompressing Kernel Image ... OK
4528 Booting using flat device tree at 0x300000
4529 Using MPC85xx ADS machine description
4530 Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb
4531 [snip]
4532
4533
4534 More About U-Boot Image Types:
4535 ------------------------------
4536
4537 U-Boot supports the following image types:
4538
4539 "Standalone Programs" are directly runnable in the environment
4540 provided by U-Boot; it is expected that (if they behave
4541 well) you can continue to work in U-Boot after return from
4542 the Standalone Program.
4543 "OS Kernel Images" are usually images of some Embedded OS which
4544 will take over control completely. Usually these programs
4545 will install their own set of exception handlers, device
4546 drivers, set up the MMU, etc. - this means, that you cannot
4547 expect to re-enter U-Boot except by resetting the CPU.
4548 "RAMDisk Images" are more or less just data blocks, and their
4549 parameters (address, size) are passed to an OS kernel that is
4550 being started.
4551 "Multi-File Images" contain several images, typically an OS
4552 (Linux) kernel image and one or more data images like
4553 RAMDisks. This construct is useful for instance when you want
4554 to boot over the network using BOOTP etc., where the boot
4555 server provides just a single image file, but you want to get
4556 for instance an OS kernel and a RAMDisk image.
4557
4558 "Multi-File Images" start with a list of image sizes, each
4559 image size (in bytes) specified by an "uint32_t" in network
4560 byte order. This list is terminated by an "(uint32_t)0".
4561 Immediately after the terminating 0 follow the images, one by
4562 one, all aligned on "uint32_t" boundaries (size rounded up to
4563 a multiple of 4 bytes).
4564
4565 "Firmware Images" are binary images containing firmware (like
4566 U-Boot or FPGA images) which usually will be programmed to
4567 flash memory.
4568
4569 "Script files" are command sequences that will be executed by
4570 U-Boot's command interpreter; this feature is especially
4571 useful when you configure U-Boot to use a real shell (hush)
4572 as command interpreter.
4573
4574 Booting the Linux zImage:
4575 -------------------------
4576
4577 On some platforms, it's possible to boot Linux zImage. This is done
4578 using the "bootz" command. The syntax of "bootz" command is the same
4579 as the syntax of "bootm" command.
4580
4581 Note, defining the CONFIG_SUPPORT_RAW_INITRD allows user to supply
4582 kernel with raw initrd images. The syntax is slightly different, the
4583 address of the initrd must be augmented by it's size, in the following
4584 format: "<initrd addres>:<initrd size>".
4585
4586
4587 Standalone HOWTO:
4588 =================
4589
4590 One of the features of U-Boot is that you can dynamically load and
4591 run "standalone" applications, which can use some resources of
4592 U-Boot like console I/O functions or interrupt services.
4593
4594 Two simple examples are included with the sources:
4595
4596 "Hello World" Demo:
4597 -------------------
4598
4599 'examples/hello_world.c' contains a small "Hello World" Demo
4600 application; it is automatically compiled when you build U-Boot.
4601 It's configured to run at address 0x00040004, so you can play with it
4602 like that:
4603
4604 => loads
4605 ## Ready for S-Record download ...
4606 ~>examples/hello_world.srec
4607 1 2 3 4 5 6 7 8 9 10 11 ...
4608 [file transfer complete]
4609 [connected]
4610 ## Start Addr = 0x00040004
4611
4612 => go 40004 Hello World! This is a test.
4613 ## Starting application at 0x00040004 ...
4614 Hello World
4615 argc = 7
4616 argv[0] = "40004"
4617 argv[1] = "Hello"
4618 argv[2] = "World!"
4619 argv[3] = "This"
4620 argv[4] = "is"
4621 argv[5] = "a"
4622 argv[6] = "test."
4623 argv[7] = "<NULL>"
4624 Hit any key to exit ...
4625
4626 ## Application terminated, rc = 0x0
4627
4628 Another example, which demonstrates how to register a CPM interrupt
4629 handler with the U-Boot code, can be found in 'examples/timer.c'.
4630 Here, a CPM timer is set up to generate an interrupt every second.
4631 The interrupt service routine is trivial, just printing a '.'
4632 character, but this is just a demo program. The application can be
4633 controlled by the following keys:
4634
4635 ? - print current values og the CPM Timer registers
4636 b - enable interrupts and start timer
4637 e - stop timer and disable interrupts
4638 q - quit application
4639
4640 => loads
4641 ## Ready for S-Record download ...
4642 ~>examples/timer.srec
4643 1 2 3 4 5 6 7 8 9 10 11 ...
4644 [file transfer complete]
4645 [connected]
4646 ## Start Addr = 0x00040004
4647
4648 => go 40004
4649 ## Starting application at 0x00040004 ...
4650 TIMERS=0xfff00980
4651 Using timer 1
4652 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
4653
4654 Hit 'b':
4655 [q, b, e, ?] Set interval 1000000 us
4656 Enabling timer
4657 Hit '?':
4658 [q, b, e, ?] ........
4659 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
4660 Hit '?':
4661 [q, b, e, ?] .
4662 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
4663 Hit '?':
4664 [q, b, e, ?] .
4665 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
4666 Hit '?':
4667 [q, b, e, ?] .
4668 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
4669 Hit 'e':
4670 [q, b, e, ?] ...Stopping timer
4671 Hit 'q':
4672 [q, b, e, ?] ## Application terminated, rc = 0x0
4673
4674
4675 Minicom warning:
4676 ================
4677
4678 Over time, many people have reported problems when trying to use the
4679 "minicom" terminal emulation program for serial download. I (wd)
4680 consider minicom to be broken, and recommend not to use it. Under
4681 Unix, I recommend to use C-Kermit for general purpose use (and
4682 especially for kermit binary protocol download ("loadb" command), and
4683 use "cu" for S-Record download ("loads" command). See
4684 http://www.denx.de/wiki/view/DULG/SystemSetup#Section_4.3.
4685 for help with kermit.
4686
4687
4688 Nevertheless, if you absolutely want to use it try adding this
4689 configuration to your "File transfer protocols" section:
4690
4691 Name Program Name U/D FullScr IO-Red. Multi
4692 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
4693 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
4694
4695
4696 NetBSD Notes:
4697 =============
4698
4699 Starting at version 0.9.2, U-Boot supports NetBSD both as host
4700 (build U-Boot) and target system (boots NetBSD/mpc8xx).
4701
4702 Building requires a cross environment; it is known to work on
4703 NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
4704 need gmake since the Makefiles are not compatible with BSD make).
4705 Note that the cross-powerpc package does not install include files;
4706 attempting to build U-Boot will fail because <machine/ansi.h> is
4707 missing. This file has to be installed and patched manually:
4708
4709 # cd /usr/pkg/cross/powerpc-netbsd/include
4710 # mkdir powerpc
4711 # ln -s powerpc machine
4712 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
4713 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
4714
4715 Native builds *don't* work due to incompatibilities between native
4716 and U-Boot include files.
4717
4718 Booting assumes that (the first part of) the image booted is a
4719 stage-2 loader which in turn loads and then invokes the kernel
4720 proper. Loader sources will eventually appear in the NetBSD source
4721 tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
4722 meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz
4723
4724
4725 Implementation Internals:
4726 =========================
4727
4728 The following is not intended to be a complete description of every
4729 implementation detail. However, it should help to understand the
4730 inner workings of U-Boot and make it easier to port it to custom
4731 hardware.
4732
4733
4734 Initial Stack, Global Data:
4735 ---------------------------
4736
4737 The implementation of U-Boot is complicated by the fact that U-Boot
4738 starts running out of ROM (flash memory), usually without access to
4739 system RAM (because the memory controller is not initialized yet).
4740 This means that we don't have writable Data or BSS segments, and BSS
4741 is not initialized as zero. To be able to get a C environment working
4742 at all, we have to allocate at least a minimal stack. Implementation
4743 options for this are defined and restricted by the CPU used: Some CPU
4744 models provide on-chip memory (like the IMMR area on MPC8xx and
4745 MPC826x processors), on others (parts of) the data cache can be
4746 locked as (mis-) used as memory, etc.
4747
4748 Chris Hallinan posted a good summary of these issues to the
4749 U-Boot mailing list:
4750
4751 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
4752 From: "Chris Hallinan" <clh@net1plus.com>
4753 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
4754 ...
4755
4756 Correct me if I'm wrong, folks, but the way I understand it
4757 is this: Using DCACHE as initial RAM for Stack, etc, does not
4758 require any physical RAM backing up the cache. The cleverness
4759 is that the cache is being used as a temporary supply of
4760 necessary storage before the SDRAM controller is setup. It's
4761 beyond the scope of this list to explain the details, but you
4762 can see how this works by studying the cache architecture and
4763 operation in the architecture and processor-specific manuals.
4764
4765 OCM is On Chip Memory, which I believe the 405GP has 4K. It
4766 is another option for the system designer to use as an
4767 initial stack/RAM area prior to SDRAM being available. Either
4768 option should work for you. Using CS 4 should be fine if your
4769 board designers haven't used it for something that would
4770 cause you grief during the initial boot! It is frequently not
4771 used.
4772
4773 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere
4774 with your processor/board/system design. The default value
4775 you will find in any recent u-boot distribution in
4776 walnut.h should work for you. I'd set it to a value larger
4777 than your SDRAM module. If you have a 64MB SDRAM module, set
4778 it above 400_0000. Just make sure your board has no resources
4779 that are supposed to respond to that address! That code in
4780 start.S has been around a while and should work as is when
4781 you get the config right.
4782
4783 -Chris Hallinan
4784 DS4.COM, Inc.
4785
4786 It is essential to remember this, since it has some impact on the C
4787 code for the initialization procedures:
4788
4789 * Initialized global data (data segment) is read-only. Do not attempt
4790 to write it.
4791
4792 * Do not use any uninitialized global data (or implicitly initialized
4793 as zero data - BSS segment) at all - this is undefined, initiali-
4794 zation is performed later (when relocating to RAM).
4795
4796 * Stack space is very limited. Avoid big data buffers or things like
4797 that.
4798
4799 Having only the stack as writable memory limits means we cannot use
4800 normal global data to share information between the code. But it
4801 turned out that the implementation of U-Boot can be greatly
4802 simplified by making a global data structure (gd_t) available to all
4803 functions. We could pass a pointer to this data as argument to _all_
4804 functions, but this would bloat the code. Instead we use a feature of
4805 the GCC compiler (Global Register Variables) to share the data: we
4806 place a pointer (gd) to the global data into a register which we
4807 reserve for this purpose.
4808
4809 When choosing a register for such a purpose we are restricted by the
4810 relevant (E)ABI specifications for the current architecture, and by
4811 GCC's implementation.
4812
4813 For PowerPC, the following registers have specific use:
4814 R1: stack pointer
4815 R2: reserved for system use
4816 R3-R4: parameter passing and return values
4817 R5-R10: parameter passing
4818 R13: small data area pointer
4819 R30: GOT pointer
4820 R31: frame pointer
4821
4822 (U-Boot also uses R12 as internal GOT pointer. r12
4823 is a volatile register so r12 needs to be reset when
4824 going back and forth between asm and C)
4825
4826 ==> U-Boot will use R2 to hold a pointer to the global data
4827
4828 Note: on PPC, we could use a static initializer (since the
4829 address of the global data structure is known at compile time),
4830 but it turned out that reserving a register results in somewhat
4831 smaller code - although the code savings are not that big (on
4832 average for all boards 752 bytes for the whole U-Boot image,
4833 624 text + 127 data).
4834
4835 On ARM, the following registers are used:
4836
4837 R0: function argument word/integer result
4838 R1-R3: function argument word
4839 R9: platform specific
4840 R10: stack limit (used only if stack checking is enabled)
4841 R11: argument (frame) pointer
4842 R12: temporary workspace
4843 R13: stack pointer
4844 R14: link register
4845 R15: program counter
4846
4847 ==> U-Boot will use R9 to hold a pointer to the global data
4848
4849 Note: on ARM, only R_ARM_RELATIVE relocations are supported.
4850
4851 On Nios II, the ABI is documented here:
4852 http://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf
4853
4854 ==> U-Boot will use gp to hold a pointer to the global data
4855
4856 Note: on Nios II, we give "-G0" option to gcc and don't use gp
4857 to access small data sections, so gp is free.
4858
4859 On NDS32, the following registers are used:
4860
4861 R0-R1: argument/return
4862 R2-R5: argument
4863 R15: temporary register for assembler
4864 R16: trampoline register
4865 R28: frame pointer (FP)
4866 R29: global pointer (GP)
4867 R30: link register (LP)
4868 R31: stack pointer (SP)
4869 PC: program counter (PC)
4870
4871 ==> U-Boot will use R10 to hold a pointer to the global data
4872
4873 NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope,
4874 or current versions of GCC may "optimize" the code too much.
4875
4876 On RISC-V, the following registers are used:
4877
4878 x0: hard-wired zero (zero)
4879 x1: return address (ra)
4880 x2: stack pointer (sp)
4881 x3: global pointer (gp)
4882 x4: thread pointer (tp)
4883 x5: link register (t0)
4884 x8: frame pointer (fp)
4885 x10-x11: arguments/return values (a0-1)
4886 x12-x17: arguments (a2-7)
4887 x28-31: temporaries (t3-6)
4888 pc: program counter (pc)
4889
4890 ==> U-Boot will use gp to hold a pointer to the global data
4891
4892 Memory Management:
4893 ------------------
4894
4895 U-Boot runs in system state and uses physical addresses, i.e. the
4896 MMU is not used either for address mapping nor for memory protection.
4897
4898 The available memory is mapped to fixed addresses using the memory
4899 controller. In this process, a contiguous block is formed for each
4900 memory type (Flash, SDRAM, SRAM), even when it consists of several
4901 physical memory banks.
4902
4903 U-Boot is installed in the first 128 kB of the first Flash bank (on
4904 TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
4905 booting and sizing and initializing DRAM, the code relocates itself
4906 to the upper end of DRAM. Immediately below the U-Boot code some
4907 memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN
4908 configuration setting]. Below that, a structure with global Board
4909 Info data is placed, followed by the stack (growing downward).
4910
4911 Additionally, some exception handler code is copied to the low 8 kB
4912 of DRAM (0x00000000 ... 0x00001FFF).
4913
4914 So a typical memory configuration with 16 MB of DRAM could look like
4915 this:
4916
4917 0x0000 0000 Exception Vector code
4918 :
4919 0x0000 1FFF
4920 0x0000 2000 Free for Application Use
4921 :
4922 :
4923
4924 :
4925 :
4926 0x00FB FF20 Monitor Stack (Growing downward)
4927 0x00FB FFAC Board Info Data and permanent copy of global data
4928 0x00FC 0000 Malloc Arena
4929 :
4930 0x00FD FFFF
4931 0x00FE 0000 RAM Copy of Monitor Code
4932 ... eventually: LCD or video framebuffer
4933 ... eventually: pRAM (Protected RAM - unchanged by reset)
4934 0x00FF FFFF [End of RAM]
4935
4936
4937 System Initialization:
4938 ----------------------
4939
4940 In the reset configuration, U-Boot starts at the reset entry point
4941 (on most PowerPC systems at address 0x00000100). Because of the reset
4942 configuration for CS0# this is a mirror of the on board Flash memory.
4943 To be able to re-map memory U-Boot then jumps to its link address.
4944 To be able to implement the initialization code in C, a (small!)
4945 initial stack is set up in the internal Dual Ported RAM (in case CPUs
4946 which provide such a feature like), or in a locked part of the data
4947 cache. After that, U-Boot initializes the CPU core, the caches and
4948 the SIU.
4949
4950 Next, all (potentially) available memory banks are mapped using a
4951 preliminary mapping. For example, we put them on 512 MB boundaries
4952 (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
4953 on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
4954 programmed for SDRAM access. Using the temporary configuration, a
4955 simple memory test is run that determines the size of the SDRAM
4956 banks.
4957
4958 When there is more than one SDRAM bank, and the banks are of
4959 different size, the largest is mapped first. For equal size, the first
4960 bank (CS2#) is mapped first. The first mapping is always for address
4961 0x00000000, with any additional banks following immediately to create
4962 contiguous memory starting from 0.
4963
4964 Then, the monitor installs itself at the upper end of the SDRAM area
4965 and allocates memory for use by malloc() and for the global Board
4966 Info data; also, the exception vector code is copied to the low RAM
4967 pages, and the final stack is set up.
4968
4969 Only after this relocation will you have a "normal" C environment;
4970 until that you are restricted in several ways, mostly because you are
4971 running from ROM, and because the code will have to be relocated to a
4972 new address in RAM.
4973
4974
4975 U-Boot Porting Guide:
4976 ----------------------
4977
4978 [Based on messages by Jerry Van Baren in the U-Boot-Users mailing
4979 list, October 2002]
4980
4981
4982 int main(int argc, char *argv[])
4983 {
4984 sighandler_t no_more_time;
4985
4986 signal(SIGALRM, no_more_time);
4987 alarm(PROJECT_DEADLINE - toSec (3 * WEEK));
4988
4989 if (available_money > available_manpower) {
4990 Pay consultant to port U-Boot;
4991 return 0;
4992 }
4993
4994 Download latest U-Boot source;
4995
4996 Subscribe to u-boot mailing list;
4997
4998 if (clueless)
4999 email("Hi, I am new to U-Boot, how do I get started?");
5000
5001 while (learning) {
5002 Read the README file in the top level directory;
5003 Read http://www.denx.de/twiki/bin/view/DULG/Manual;
5004 Read applicable doc/*.README;
5005 Read the source, Luke;
5006 /* find . -name "*.[chS]" | xargs grep -i <keyword> */
5007 }
5008
5009 if (available_money > toLocalCurrency ($2500))
5010 Buy a BDI3000;
5011 else
5012 Add a lot of aggravation and time;
5013
5014 if (a similar board exists) { /* hopefully... */
5015 cp -a board/<similar> board/<myboard>
5016 cp include/configs/<similar>.h include/configs/<myboard>.h
5017 } else {
5018 Create your own board support subdirectory;
5019 Create your own board include/configs/<myboard>.h file;
5020 }
5021 Edit new board/<myboard> files
5022 Edit new include/configs/<myboard>.h
5023
5024 while (!accepted) {
5025 while (!running) {
5026 do {
5027 Add / modify source code;
5028 } until (compiles);
5029 Debug;
5030 if (clueless)
5031 email("Hi, I am having problems...");
5032 }
5033 Send patch file to the U-Boot email list;
5034 if (reasonable critiques)
5035 Incorporate improvements from email list code review;
5036 else
5037 Defend code as written;
5038 }
5039
5040 return 0;
5041 }
5042
5043 void no_more_time (int sig)
5044 {
5045 hire_a_guru();
5046 }
5047
5048
5049 Coding Standards:
5050 -----------------
5051
5052 All contributions to U-Boot should conform to the Linux kernel
5053 coding style; see the kernel coding style guide at
5054 https://www.kernel.org/doc/html/latest/process/coding-style.html, and the
5055 script "scripts/Lindent" in your Linux kernel source directory.
5056
5057 Source files originating from a different project (for example the
5058 MTD subsystem) are generally exempt from these guidelines and are not
5059 reformatted to ease subsequent migration to newer versions of those
5060 sources.
5061
5062 Please note that U-Boot is implemented in C (and to some small parts in
5063 Assembler); no C++ is used, so please do not use C++ style comments (//)
5064 in your code.
5065
5066 Please also stick to the following formatting rules:
5067 - remove any trailing white space
5068 - use TAB characters for indentation and vertical alignment, not spaces
5069 - make sure NOT to use DOS '\r\n' line feeds
5070 - do not add more than 2 consecutive empty lines to source files
5071 - do not add trailing empty lines to source files
5072
5073 Submissions which do not conform to the standards may be returned
5074 with a request to reformat the changes.
5075
5076
5077 Submitting Patches:
5078 -------------------
5079
5080 Since the number of patches for U-Boot is growing, we need to
5081 establish some rules. Submissions which do not conform to these rules
5082 may be rejected, even when they contain important and valuable stuff.
5083
5084 Please see http://www.denx.de/wiki/U-Boot/Patches for details.
5085
5086 Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>;
5087 see https://lists.denx.de/listinfo/u-boot
5088
5089 When you send a patch, please include the following information with
5090 it:
5091
5092 * For bug fixes: a description of the bug and how your patch fixes
5093 this bug. Please try to include a way of demonstrating that the
5094 patch actually fixes something.
5095
5096 * For new features: a description of the feature and your
5097 implementation.
5098
5099 * A CHANGELOG entry as plaintext (separate from the patch)
5100
5101 * For major contributions, add a MAINTAINERS file with your
5102 information and associated file and directory references.
5103
5104 * When you add support for a new board, don't forget to add a
5105 maintainer e-mail address to the boards.cfg file, too.
5106
5107 * If your patch adds new configuration options, don't forget to
5108 document these in the README file.
5109
5110 * The patch itself. If you are using git (which is *strongly*
5111 recommended) you can easily generate the patch using the
5112 "git format-patch". If you then use "git send-email" to send it to
5113 the U-Boot mailing list, you will avoid most of the common problems
5114 with some other mail clients.
5115
5116 If you cannot use git, use "diff -purN OLD NEW". If your version of
5117 diff does not support these options, then get the latest version of
5118 GNU diff.
5119
5120 The current directory when running this command shall be the parent
5121 directory of the U-Boot source tree (i. e. please make sure that
5122 your patch includes sufficient directory information for the
5123 affected files).
5124
5125 We prefer patches as plain text. MIME attachments are discouraged,
5126 and compressed attachments must not be used.
5127
5128 * If one logical set of modifications affects or creates several
5129 files, all these changes shall be submitted in a SINGLE patch file.
5130
5131 * Changesets that contain different, unrelated modifications shall be
5132 submitted as SEPARATE patches, one patch per changeset.
5133
5134
5135 Notes:
5136
5137 * Before sending the patch, run the buildman script on your patched
5138 source tree and make sure that no errors or warnings are reported
5139 for any of the boards.
5140
5141 * Keep your modifications to the necessary minimum: A patch
5142 containing several unrelated changes or arbitrary reformats will be
5143 returned with a request to re-formatting / split it.
5144
5145 * If you modify existing code, make sure that your new code does not
5146 add to the memory footprint of the code ;-) Small is beautiful!
5147 When adding new features, these should compile conditionally only
5148 (using #ifdef), and the resulting code with the new feature
5149 disabled must not need more memory than the old code without your
5150 modification.
5151
5152 * Remember that there is a size limit of 100 kB per message on the
5153 u-boot mailing list. Bigger patches will be moderated. If they are
5154 reasonable and not too big, they will be acknowledged. But patches
5155 bigger than the size limit should be avoided.