2 # (C) Copyright 2000 - 2013
3 # Wolfgang Denk, DENX Software Engineering, wd@denx.de.
5 # SPDX-License-Identifier: GPL-2.0+
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
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.
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.
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.
37 In case of problems see the CHANGELOG and CREDITS files to find out
38 who contributed the specific port. The boards.cfg file lists board
41 Note: There is no CHANGELOG file in the actual U-Boot source tree;
42 it can be created dynamically from the Git log using:
50 In case you have questions about, problems with or contributions for
51 U-Boot you should send a message to the U-Boot mailing list at
52 <u-boot@lists.denx.de>. There is also an archive of previous traffic
53 on the mailing list - please search the archive before asking FAQ's.
54 Please see http://lists.denx.de/pipermail/u-boot and
55 http://dir.gmane.org/gmane.comp.boot-loaders.u-boot
58 Where to get source code:
59 =========================
61 The U-Boot source code is maintained in the git repository at
62 git://www.denx.de/git/u-boot.git ; you can browse it online at
63 http://www.denx.de/cgi-bin/gitweb.cgi?p=u-boot.git;a=summary
65 The "snapshot" links on this page allow you to download tarballs of
66 any version you might be interested in. Official releases are also
67 available for FTP download from the ftp://ftp.denx.de/pub/u-boot/
70 Pre-built (and tested) images are available from
71 ftp://ftp.denx.de/pub/u-boot/images/
77 - start from 8xxrom sources
78 - create PPCBoot project (http://sourceforge.net/projects/ppcboot)
80 - make it easier to add custom boards
81 - make it possible to add other [PowerPC] CPUs
82 - extend functions, especially:
83 * Provide extended interface to Linux boot loader
86 * PCMCIA / CompactFlash / ATA disk / SCSI ... boot
87 - create ARMBoot project (http://sourceforge.net/projects/armboot)
88 - add other CPU families (starting with ARM)
89 - create U-Boot project (http://sourceforge.net/projects/u-boot)
90 - current project page: see http://www.denx.de/wiki/U-Boot
96 The "official" name of this project is "Das U-Boot". The spelling
97 "U-Boot" shall be used in all written text (documentation, comments
98 in source files etc.). Example:
100 This is the README file for the U-Boot project.
102 File names etc. shall be based on the string "u-boot". Examples:
104 include/asm-ppc/u-boot.h
106 #include <asm/u-boot.h>
108 Variable names, preprocessor constants etc. shall be either based on
109 the string "u_boot" or on "U_BOOT". Example:
111 U_BOOT_VERSION u_boot_logo
112 IH_OS_U_BOOT u_boot_hush_start
118 Starting with the release in October 2008, the names of the releases
119 were changed from numerical release numbers without deeper meaning
120 into a time stamp based numbering. Regular releases are identified by
121 names consisting of the calendar year and month of the release date.
122 Additional fields (if present) indicate release candidates or bug fix
123 releases in "stable" maintenance trees.
126 U-Boot v2009.11 - Release November 2009
127 U-Boot v2009.11.1 - Release 1 in version November 2009 stable tree
128 U-Boot v2010.09-rc1 - Release candiate 1 for September 2010 release
134 /arch Architecture specific files
135 /arc Files generic to ARC architecture
136 /cpu CPU specific files
137 /arc700 Files specific to ARC 700 CPUs
138 /lib Architecture specific library files
139 /arm Files generic to ARM architecture
140 /cpu CPU specific files
141 /arm720t Files specific to ARM 720 CPUs
142 /arm920t Files specific to ARM 920 CPUs
143 /at91 Files specific to Atmel AT91RM9200 CPU
144 /imx Files specific to Freescale MC9328 i.MX CPUs
145 /s3c24x0 Files specific to Samsung S3C24X0 CPUs
146 /arm926ejs Files specific to ARM 926 CPUs
147 /arm1136 Files specific to ARM 1136 CPUs
148 /pxa Files specific to Intel XScale PXA CPUs
149 /sa1100 Files specific to Intel StrongARM SA1100 CPUs
150 /lib Architecture specific library files
151 /avr32 Files generic to AVR32 architecture
152 /cpu CPU specific files
153 /lib Architecture specific library files
154 /blackfin Files generic to Analog Devices Blackfin architecture
155 /cpu CPU specific files
156 /lib Architecture specific library files
157 /m68k Files generic to m68k architecture
158 /cpu CPU specific files
159 /mcf52x2 Files specific to Freescale ColdFire MCF52x2 CPUs
160 /mcf5227x Files specific to Freescale ColdFire MCF5227x CPUs
161 /mcf532x Files specific to Freescale ColdFire MCF5329 CPUs
162 /mcf5445x Files specific to Freescale ColdFire MCF5445x CPUs
163 /mcf547x_8x Files specific to Freescale ColdFire MCF547x_8x CPUs
164 /lib Architecture specific library files
165 /microblaze Files generic to microblaze architecture
166 /cpu CPU specific files
167 /lib Architecture specific library files
168 /mips Files generic to MIPS architecture
169 /cpu CPU specific files
170 /mips32 Files specific to MIPS32 CPUs
171 /mips64 Files specific to MIPS64 CPUs
172 /lib Architecture specific library files
173 /nds32 Files generic to NDS32 architecture
174 /cpu CPU specific files
175 /n1213 Files specific to Andes Technology N1213 CPUs
176 /lib Architecture specific library files
177 /nios2 Files generic to Altera NIOS2 architecture
178 /cpu CPU specific files
179 /lib Architecture specific library files
180 /openrisc Files generic to OpenRISC architecture
181 /cpu CPU specific files
182 /lib Architecture specific library files
183 /powerpc Files generic to PowerPC architecture
184 /cpu CPU specific files
185 /mpc5xx Files specific to Freescale MPC5xx CPUs
186 /mpc5xxx Files specific to Freescale MPC5xxx CPUs
187 /mpc8xx Files specific to Freescale MPC8xx CPUs
188 /mpc8260 Files specific to Freescale MPC8260 CPUs
189 /mpc85xx Files specific to Freescale MPC85xx CPUs
190 /ppc4xx Files specific to AMCC PowerPC 4xx CPUs
191 /lib Architecture specific library files
192 /sh Files generic to SH architecture
193 /cpu CPU specific files
194 /sh2 Files specific to sh2 CPUs
195 /sh3 Files specific to sh3 CPUs
196 /sh4 Files specific to sh4 CPUs
197 /lib Architecture specific library files
198 /sparc Files generic to SPARC architecture
199 /cpu CPU specific files
200 /leon2 Files specific to Gaisler LEON2 SPARC CPU
201 /leon3 Files specific to Gaisler LEON3 SPARC CPU
202 /lib Architecture specific library files
203 /x86 Files generic to x86 architecture
204 /cpu CPU specific files
205 /lib Architecture specific library files
206 /api Machine/arch independent API for external apps
207 /board Board dependent files
208 /common Misc architecture independent functions
209 /disk Code for disk drive partition handling
210 /doc Documentation (don't expect too much)
211 /drivers Commonly used device drivers
212 /dts Contains Makefile for building internal U-Boot fdt.
213 /examples Example code for standalone applications, etc.
214 /fs Filesystem code (cramfs, ext2, jffs2, etc.)
215 /include Header Files
216 /lib Files generic to all architectures
217 /libfdt Library files to support flattened device trees
218 /lzma Library files to support LZMA decompression
219 /lzo Library files to support LZO decompression
221 /post Power On Self Test
222 /spl Secondary Program Loader framework
223 /tools Tools to build S-Record or U-Boot images, etc.
225 Software Configuration:
226 =======================
228 Configuration is usually done using C preprocessor defines; the
229 rationale behind that is to avoid dead code whenever possible.
231 There are two classes of configuration variables:
233 * Configuration _OPTIONS_:
234 These are selectable by the user and have names beginning with
237 * Configuration _SETTINGS_:
238 These depend on the hardware etc. and should not be meddled with if
239 you don't know what you're doing; they have names beginning with
242 Later we will add a configuration tool - probably similar to or even
243 identical to what's used for the Linux kernel. Right now, we have to
244 do the configuration by hand, which means creating some symbolic
245 links and editing some configuration files. We use the TQM8xxL boards
249 Selection of Processor Architecture and Board Type:
250 ---------------------------------------------------
252 For all supported boards there are ready-to-use default
253 configurations available; just type "make <board_name>_defconfig".
255 Example: For a TQM823L module type:
258 make TQM823L_defconfig
260 For the Cogent platform, you need to specify the CPU type as well;
261 e.g. "make cogent_mpc8xx_defconfig". And also configure the cogent
262 directory according to the instructions in cogent/README.
268 U-Boot can be built natively to run on a Linux host using the 'sandbox'
269 board. This allows feature development which is not board- or architecture-
270 specific to be undertaken on a native platform. The sandbox is also used to
271 run some of U-Boot's tests.
273 See board/sandbox/README.sandbox for more details.
276 Board Initialisation Flow:
277 --------------------------
279 This is the intended start-up flow for boards. This should apply for both
280 SPL and U-Boot proper (i.e. they both follow the same rules). At present SPL
281 mostly uses a separate code path, but the funtion names and roles of each
282 function are the same. Some boards or architectures may not conform to this.
283 At least most ARM boards which use CONFIG_SPL_FRAMEWORK conform to this.
285 Execution starts with start.S with three functions called during init after
286 that. The purpose and limitations of each is described below.
289 - purpose: essential init to permit execution to reach board_init_f()
290 - no global_data or BSS
291 - there is no stack (ARMv7 may have one but it will soon be removed)
292 - must not set up SDRAM or use console
293 - must only do the bare minimum to allow execution to continue to
295 - this is almost never needed
296 - return normally from this function
299 - purpose: set up the machine ready for running board_init_r():
300 i.e. SDRAM and serial UART
301 - global_data is available
303 - BSS is not available, so you cannot use global/static variables,
304 only stack variables and global_data
306 Non-SPL-specific notes:
307 - dram_init() is called to set up DRAM. If already done in SPL this
311 - you can override the entire board_init_f() function with your own
313 - preloader_console_init() can be called here in extremis
314 - should set up SDRAM, and anything needed to make the UART work
315 - these is no need to clear BSS, it will be done by crt0.S
316 - must return normally from this function (don't call board_init_r()
319 Here the BSS is cleared. For SPL, if CONFIG_SPL_STACK_R is defined, then at
320 this point the stack and global_data are relocated to below
321 CONFIG_SPL_STACK_R_ADDR. For non-SPL, U-Boot is relocated to run at the top of
325 - purpose: main execution, common code
326 - global_data is available
328 - BSS is available, all static/global variables can be used
329 - execution eventually continues to main_loop()
331 Non-SPL-specific notes:
332 - U-Boot is relocated to the top of memory and is now running from
336 - stack is optionally in SDRAM, if CONFIG_SPL_STACK_R is defined and
337 CONFIG_SPL_STACK_R_ADDR points into SDRAM
338 - preloader_console_init() can be called here - typically this is
339 done by defining CONFIG_SPL_BOARD_INIT and then supplying a
340 spl_board_init() function containing this call
341 - loads U-Boot or (in falcon mode) Linux
345 Configuration Options:
346 ----------------------
348 Configuration depends on the combination of board and CPU type; all
349 such information is kept in a configuration file
350 "include/configs/<board_name>.h".
352 Example: For a TQM823L module, all configuration settings are in
353 "include/configs/TQM823L.h".
356 Many of the options are named exactly as the corresponding Linux
357 kernel configuration options. The intention is to make it easier to
358 build a config tool - later.
361 The following options need to be configured:
363 - CPU Type: Define exactly one, e.g. CONFIG_MPC85XX.
365 - Board Type: Define exactly one, e.g. CONFIG_MPC8540ADS.
367 - CPU Daughterboard Type: (if CONFIG_ATSTK1000 is defined)
368 Define exactly one, e.g. CONFIG_ATSTK1002
370 - CPU Module Type: (if CONFIG_COGENT is defined)
371 Define exactly one of
373 --- FIXME --- not tested yet:
374 CONFIG_CMA286_60, CONFIG_CMA286_21, CONFIG_CMA286_60P,
375 CONFIG_CMA287_23, CONFIG_CMA287_50
377 - Motherboard Type: (if CONFIG_COGENT is defined)
378 Define exactly one of
379 CONFIG_CMA101, CONFIG_CMA102
381 - Motherboard I/O Modules: (if CONFIG_COGENT is defined)
382 Define one or more of
385 - Motherboard Options: (if CONFIG_CMA101 or CONFIG_CMA102 are defined)
386 Define one or more of
387 CONFIG_LCD_HEARTBEAT - update a character position on
388 the LCD display every second with
391 - Marvell Family Member
392 CONFIG_SYS_MVFS - define it if you want to enable
393 multiple fs option at one time
394 for marvell soc family
396 - 8xx CPU Options: (if using an MPC8xx CPU)
397 CONFIG_8xx_GCLK_FREQ - deprecated: CPU clock if
398 get_gclk_freq() cannot work
399 e.g. if there is no 32KHz
400 reference PIT/RTC clock
401 CONFIG_8xx_OSCLK - PLL input clock (either EXTCLK
404 - 859/866/885 CPU options: (if using a MPC859 or MPC866 or MPC885 CPU):
405 CONFIG_SYS_8xx_CPUCLK_MIN
406 CONFIG_SYS_8xx_CPUCLK_MAX
407 CONFIG_8xx_CPUCLK_DEFAULT
408 See doc/README.MPC866
410 CONFIG_SYS_MEASURE_CPUCLK
412 Define this to measure the actual CPU clock instead
413 of relying on the correctness of the configured
414 values. Mostly useful for board bringup to make sure
415 the PLL is locked at the intended frequency. Note
416 that this requires a (stable) reference clock (32 kHz
417 RTC clock or CONFIG_SYS_8XX_XIN)
419 CONFIG_SYS_DELAYED_ICACHE
421 Define this option if you want to enable the
422 ICache only when Code runs from RAM.
427 Specifies that the core is a 64-bit PowerPC implementation (implements
428 the "64" category of the Power ISA). This is necessary for ePAPR
429 compliance, among other possible reasons.
431 CONFIG_SYS_FSL_TBCLK_DIV
433 Defines the core time base clock divider ratio compared to the
434 system clock. On most PQ3 devices this is 8, on newer QorIQ
435 devices it can be 16 or 32. The ratio varies from SoC to Soc.
437 CONFIG_SYS_FSL_PCIE_COMPAT
439 Defines the string to utilize when trying to match PCIe device
440 tree nodes for the given platform.
442 CONFIG_SYS_PPC_E500_DEBUG_TLB
444 Enables a temporary TLB entry to be used during boot to work
445 around limitations in e500v1 and e500v2 external debugger
446 support. This reduces the portions of the boot code where
447 breakpoints and single stepping do not work. The value of this
448 symbol should be set to the TLB1 entry to be used for this
451 CONFIG_SYS_FSL_ERRATUM_A004510
453 Enables a workaround for erratum A004510. If set,
454 then CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV and
455 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY must be set.
457 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV
458 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV2 (optional)
460 Defines one or two SoC revisions (low 8 bits of SVR)
461 for which the A004510 workaround should be applied.
463 The rest of SVR is either not relevant to the decision
464 of whether the erratum is present (e.g. p2040 versus
465 p2041) or is implied by the build target, which controls
466 whether CONFIG_SYS_FSL_ERRATUM_A004510 is set.
468 See Freescale App Note 4493 for more information about
471 CONFIG_A003399_NOR_WORKAROUND
472 Enables a workaround for IFC erratum A003399. It is only
473 required during NOR boot.
475 CONFIG_A008044_WORKAROUND
476 Enables a workaround for T1040/T1042 erratum A008044. It is only
477 required during NAND boot and valid for Rev 1.0 SoC revision
479 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY
481 This is the value to write into CCSR offset 0x18600
482 according to the A004510 workaround.
484 CONFIG_SYS_FSL_DSP_DDR_ADDR
485 This value denotes start offset of DDR memory which is
486 connected exclusively to the DSP cores.
488 CONFIG_SYS_FSL_DSP_M2_RAM_ADDR
489 This value denotes start offset of M2 memory
490 which is directly connected to the DSP core.
492 CONFIG_SYS_FSL_DSP_M3_RAM_ADDR
493 This value denotes start offset of M3 memory which is directly
494 connected to the DSP core.
496 CONFIG_SYS_FSL_DSP_CCSRBAR_DEFAULT
497 This value denotes start offset of DSP CCSR space.
499 CONFIG_SYS_FSL_SINGLE_SOURCE_CLK
500 Single Source Clock is clocking mode present in some of FSL SoC's.
501 In this mode, a single differential clock is used to supply
502 clocks to the sysclock, ddrclock and usbclock.
504 CONFIG_SYS_CPC_REINIT_F
505 This CONFIG is defined when the CPC is configured as SRAM at the
506 time of U-boot entry and is required to be re-initialized.
509 Indicates this SoC supports deep sleep feature. If deep sleep is
510 supported, core will start to execute uboot when wakes up.
512 - Generic CPU options:
513 CONFIG_SYS_GENERIC_GLOBAL_DATA
514 Defines global data is initialized in generic board board_init_f().
515 If this macro is defined, global data is created and cleared in
516 generic board board_init_f(). Without this macro, architecture/board
517 should initialize global data before calling board_init_f().
519 CONFIG_SYS_BIG_ENDIAN, CONFIG_SYS_LITTLE_ENDIAN
521 Defines the endianess of the CPU. Implementation of those
522 values is arch specific.
525 Freescale DDR driver in use. This type of DDR controller is
526 found in mpc83xx, mpc85xx, mpc86xx as well as some ARM core
529 CONFIG_SYS_FSL_DDR_ADDR
530 Freescale DDR memory-mapped register base.
532 CONFIG_SYS_FSL_DDR_EMU
533 Specify emulator support for DDR. Some DDR features such as
534 deskew training are not available.
536 CONFIG_SYS_FSL_DDRC_GEN1
537 Freescale DDR1 controller.
539 CONFIG_SYS_FSL_DDRC_GEN2
540 Freescale DDR2 controller.
542 CONFIG_SYS_FSL_DDRC_GEN3
543 Freescale DDR3 controller.
545 CONFIG_SYS_FSL_DDRC_GEN4
546 Freescale DDR4 controller.
548 CONFIG_SYS_FSL_DDRC_ARM_GEN3
549 Freescale DDR3 controller for ARM-based SoCs.
552 Board config to use DDR1. It can be enabled for SoCs with
553 Freescale DDR1 or DDR2 controllers, depending on the board
557 Board config to use DDR2. It can be eanbeld for SoCs with
558 Freescale DDR2 or DDR3 controllers, depending on the board
562 Board config to use DDR3. It can be enabled for SoCs with
563 Freescale DDR3 or DDR3L controllers.
566 Board config to use DDR3L. It can be enabled for SoCs with
570 Board config to use DDR4. It can be enabled for SoCs with
573 CONFIG_SYS_FSL_IFC_BE
574 Defines the IFC controller register space as Big Endian
576 CONFIG_SYS_FSL_IFC_LE
577 Defines the IFC controller register space as Little Endian
579 CONFIG_SYS_FSL_PBL_PBI
580 It enables addition of RCW (Power on reset configuration) in built image.
581 Please refer doc/README.pblimage for more details
583 CONFIG_SYS_FSL_PBL_RCW
584 It adds PBI(pre-boot instructions) commands in u-boot build image.
585 PBI commands can be used to configure SoC before it starts the execution.
586 Please refer doc/README.pblimage for more details
589 It adds a target to create boot binary having SPL binary in PBI format
590 concatenated with u-boot binary.
592 CONFIG_SYS_FSL_DDR_BE
593 Defines the DDR controller register space as Big Endian
595 CONFIG_SYS_FSL_DDR_LE
596 Defines the DDR controller register space as Little Endian
598 CONFIG_SYS_FSL_DDR_SDRAM_BASE_PHY
599 Physical address from the view of DDR controllers. It is the
600 same as CONFIG_SYS_DDR_SDRAM_BASE for all Power SoCs. But
601 it could be different for ARM SoCs.
603 CONFIG_SYS_FSL_DDR_INTLV_256B
604 DDR controller interleaving on 256-byte. This is a special
605 interleaving mode, handled by Dickens for Freescale layerscape
608 CONFIG_SYS_FSL_DDR_MAIN_NUM_CTRLS
609 Number of controllers used as main memory.
611 CONFIG_SYS_FSL_OTHER_DDR_NUM_CTRLS
612 Number of controllers used for other than main memory.
614 CONFIG_SYS_FSL_SEC_BE
615 Defines the SEC controller register space as Big Endian
617 CONFIG_SYS_FSL_SEC_LE
618 Defines the SEC controller register space as Little Endian
620 - Intel Monahans options:
621 CONFIG_SYS_MONAHANS_RUN_MODE_OSC_RATIO
623 Defines the Monahans run mode to oscillator
624 ratio. Valid values are 8, 16, 24, 31. The core
625 frequency is this value multiplied by 13 MHz.
627 CONFIG_SYS_MONAHANS_TURBO_RUN_MODE_RATIO
629 Defines the Monahans turbo mode to oscillator
630 ratio. Valid values are 1 (default if undefined) and
631 2. The core frequency as calculated above is multiplied
635 CONFIG_SYS_INIT_SP_OFFSET
637 Offset relative to CONFIG_SYS_SDRAM_BASE for initial stack
638 pointer. This is needed for the temporary stack before
641 CONFIG_SYS_MIPS_CACHE_MODE
643 Cache operation mode for the MIPS CPU.
644 See also arch/mips/include/asm/mipsregs.h.
646 CONF_CM_CACHABLE_NO_WA
649 CONF_CM_CACHABLE_NONCOHERENT
653 CONF_CM_CACHABLE_ACCELERATED
655 CONFIG_SYS_XWAY_EBU_BOOTCFG
657 Special option for Lantiq XWAY SoCs for booting from NOR flash.
658 See also arch/mips/cpu/mips32/start.S.
660 CONFIG_XWAY_SWAP_BYTES
662 Enable compilation of tools/xway-swap-bytes needed for Lantiq
663 XWAY SoCs for booting from NOR flash. The U-Boot image needs to
664 be swapped if a flash programmer is used.
667 CONFIG_SYS_EXCEPTION_VECTORS_HIGH
669 Select high exception vectors of the ARM core, e.g., do not
670 clear the V bit of the c1 register of CP15.
672 CONFIG_SYS_THUMB_BUILD
674 Use this flag to build U-Boot using the Thumb instruction
675 set for ARM architectures. Thumb instruction set provides
676 better code density. For ARM architectures that support
677 Thumb2 this flag will result in Thumb2 code generated by
680 CONFIG_ARM_ERRATA_716044
681 CONFIG_ARM_ERRATA_742230
682 CONFIG_ARM_ERRATA_743622
683 CONFIG_ARM_ERRATA_751472
684 CONFIG_ARM_ERRATA_794072
685 CONFIG_ARM_ERRATA_761320
687 If set, the workarounds for these ARM errata are applied early
688 during U-Boot startup. Note that these options force the
689 workarounds to be applied; no CPU-type/version detection
690 exists, unlike the similar options in the Linux kernel. Do not
691 set these options unless they apply!
694 Generic timer clock source frequency.
696 COUNTER_FREQUENCY_REAL
697 Generic timer clock source frequency if the real clock is
698 different from COUNTER_FREQUENCY, and can only be determined
701 NOTE: The following can be machine specific errata. These
702 do have ability to provide rudimentary version and machine
703 specific checks, but expect no product checks.
704 CONFIG_ARM_ERRATA_430973
705 CONFIG_ARM_ERRATA_454179
706 CONFIG_ARM_ERRATA_621766
707 CONFIG_ARM_ERRATA_798870
710 CONFIG_TEGRA_SUPPORT_NON_SECURE
712 Support executing U-Boot in non-secure (NS) mode. Certain
713 impossible actions will be skipped if the CPU is in NS mode,
714 such as ARM architectural timer initialization.
716 - Linux Kernel Interface:
719 U-Boot stores all clock information in Hz
720 internally. For binary compatibility with older Linux
721 kernels (which expect the clocks passed in the
722 bd_info data to be in MHz) the environment variable
723 "clocks_in_mhz" can be defined so that U-Boot
724 converts clock data to MHZ before passing it to the
726 When CONFIG_CLOCKS_IN_MHZ is defined, a definition of
727 "clocks_in_mhz=1" is automatically included in the
730 CONFIG_MEMSIZE_IN_BYTES [relevant for MIPS only]
732 When transferring memsize parameter to Linux, some versions
733 expect it to be in bytes, others in MB.
734 Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes.
738 New kernel versions are expecting firmware settings to be
739 passed using flattened device trees (based on open firmware
743 * New libfdt-based support
744 * Adds the "fdt" command
745 * The bootm command automatically updates the fdt
747 OF_CPU - The proper name of the cpus node (only required for
748 MPC512X and MPC5xxx based boards).
749 OF_SOC - The proper name of the soc node (only required for
750 MPC512X and MPC5xxx based boards).
751 OF_TBCLK - The timebase frequency.
752 OF_STDOUT_PATH - The path to the console device
754 boards with QUICC Engines require OF_QE to set UCC MAC
757 CONFIG_OF_BOARD_SETUP
759 Board code has addition modification that it wants to make
760 to the flat device tree before handing it off to the kernel
762 CONFIG_OF_SYSTEM_SETUP
764 Other code has addition modification that it wants to make
765 to the flat device tree before handing it off to the kernel.
766 This causes ft_system_setup() to be called before booting
771 This define fills in the correct boot CPU in the boot
772 param header, the default value is zero if undefined.
776 U-Boot can detect if an IDE device is present or not.
777 If not, and this new config option is activated, U-Boot
778 removes the ATA node from the DTS before booting Linux,
779 so the Linux IDE driver does not probe the device and
780 crash. This is needed for buggy hardware (uc101) where
781 no pull down resistor is connected to the signal IDE5V_DD7.
783 CONFIG_MACH_TYPE [relevant for ARM only][mandatory]
785 This setting is mandatory for all boards that have only one
786 machine type and must be used to specify the machine type
787 number as it appears in the ARM machine registry
788 (see http://www.arm.linux.org.uk/developer/machines/).
789 Only boards that have multiple machine types supported
790 in a single configuration file and the machine type is
791 runtime discoverable, do not have to use this setting.
793 - vxWorks boot parameters:
795 bootvx constructs a valid bootline using the following
796 environments variables: bootfile, ipaddr, serverip, hostname.
797 It loads the vxWorks image pointed bootfile.
799 CONFIG_SYS_VXWORKS_BOOT_DEVICE - The vxworks device name
800 CONFIG_SYS_VXWORKS_MAC_PTR - Ethernet 6 byte MA -address
801 CONFIG_SYS_VXWORKS_SERVERNAME - Name of the server
802 CONFIG_SYS_VXWORKS_BOOT_ADDR - Address of boot parameters
804 CONFIG_SYS_VXWORKS_ADD_PARAMS
806 Add it at the end of the bootline. E.g "u=username pw=secret"
808 Note: If a "bootargs" environment is defined, it will overwride
809 the defaults discussed just above.
811 - Cache Configuration:
812 CONFIG_SYS_ICACHE_OFF - Do not enable instruction cache in U-Boot
813 CONFIG_SYS_DCACHE_OFF - Do not enable data cache in U-Boot
814 CONFIG_SYS_L2CACHE_OFF- Do not enable L2 cache in U-Boot
816 - Cache Configuration for ARM:
817 CONFIG_SYS_L2_PL310 - Enable support for ARM PL310 L2 cache
819 CONFIG_SYS_PL310_BASE - Physical base address of PL310
820 controller register space
825 Define this if you want support for Amba PrimeCell PL010 UARTs.
829 Define this if you want support for Amba PrimeCell PL011 UARTs.
833 If you have Amba PrimeCell PL011 UARTs, set this variable to
834 the clock speed of the UARTs.
838 If you have Amba PrimeCell PL010 or PL011 UARTs on your board,
839 define this to a list of base addresses for each (supported)
840 port. See e.g. include/configs/versatile.h
842 CONFIG_PL011_SERIAL_RLCR
844 Some vendor versions of PL011 serial ports (e.g. ST-Ericsson U8500)
845 have separate receive and transmit line control registers. Set
846 this variable to initialize the extra register.
848 CONFIG_PL011_SERIAL_FLUSH_ON_INIT
850 On some platforms (e.g. U8500) U-Boot is loaded by a second stage
851 boot loader that has already initialized the UART. Define this
852 variable to flush the UART at init time.
854 CONFIG_SERIAL_HW_FLOW_CONTROL
856 Define this variable to enable hw flow control in serial driver.
857 Current user of this option is drivers/serial/nsl16550.c driver
860 Depending on board, define exactly one serial port
861 (like CONFIG_8xx_CONS_SMC1, CONFIG_8xx_CONS_SMC2,
862 CONFIG_8xx_CONS_SCC1, ...), or switch off the serial
863 console by defining CONFIG_8xx_CONS_NONE
865 Note: if CONFIG_8xx_CONS_NONE is defined, the serial
866 port routines must be defined elsewhere
867 (i.e. serial_init(), serial_getc(), ...)
870 Enables console device for a color framebuffer. Needs following
871 defines (cf. smiLynxEM, i8042)
872 VIDEO_FB_LITTLE_ENDIAN graphic memory organisation
874 VIDEO_HW_RECTFILL graphic chip supports
877 VIDEO_HW_BITBLT graphic chip supports
878 bit-blit (cf. smiLynxEM)
879 VIDEO_VISIBLE_COLS visible pixel columns
881 VIDEO_VISIBLE_ROWS visible pixel rows
882 VIDEO_PIXEL_SIZE bytes per pixel
883 VIDEO_DATA_FORMAT graphic data format
884 (0-5, cf. cfb_console.c)
885 VIDEO_FB_ADRS framebuffer address
886 VIDEO_KBD_INIT_FCT keyboard int fct
887 (i.e. i8042_kbd_init())
888 VIDEO_TSTC_FCT test char fct
890 VIDEO_GETC_FCT get char fct
892 CONFIG_CONSOLE_CURSOR cursor drawing on/off
893 (requires blink timer
895 CONFIG_SYS_CONSOLE_BLINK_COUNT blink interval (cf. i8042.c)
896 CONFIG_CONSOLE_TIME display time/date info in
898 (requires CONFIG_CMD_DATE)
899 CONFIG_VIDEO_LOGO display Linux logo in
901 CONFIG_VIDEO_BMP_LOGO use bmp_logo.h instead of
902 linux_logo.h for logo.
903 Requires CONFIG_VIDEO_LOGO
904 CONFIG_CONSOLE_EXTRA_INFO
905 additional board info beside
908 When CONFIG_CFB_CONSOLE_ANSI is defined, console will support
909 a limited number of ANSI escape sequences (cursor control,
910 erase functions and limited graphics rendition control).
912 When CONFIG_CFB_CONSOLE is defined, video console is
913 default i/o. Serial console can be forced with
914 environment 'console=serial'.
916 When CONFIG_SILENT_CONSOLE is defined, all console
917 messages (by U-Boot and Linux!) can be silenced with
918 the "silent" environment variable. See
919 doc/README.silent for more information.
921 CONFIG_SYS_CONSOLE_BG_COL: define the backgroundcolor, default
923 CONFIG_SYS_CONSOLE_FG_COL: define the foregroundcolor, default
927 CONFIG_BAUDRATE - in bps
928 Select one of the baudrates listed in
929 CONFIG_SYS_BAUDRATE_TABLE, see below.
930 CONFIG_SYS_BRGCLK_PRESCALE, baudrate prescale
932 - Console Rx buffer length
933 With CONFIG_SYS_SMC_RXBUFLEN it is possible to define
934 the maximum receive buffer length for the SMC.
935 This option is actual only for 82xx and 8xx possible.
936 If using CONFIG_SYS_SMC_RXBUFLEN also CONFIG_SYS_MAXIDLE
937 must be defined, to setup the maximum idle timeout for
940 - Pre-Console Buffer:
941 Prior to the console being initialised (i.e. serial UART
942 initialised etc) all console output is silently discarded.
943 Defining CONFIG_PRE_CONSOLE_BUFFER will cause U-Boot to
944 buffer any console messages prior to the console being
945 initialised to a buffer of size CONFIG_PRE_CON_BUF_SZ
946 bytes located at CONFIG_PRE_CON_BUF_ADDR. The buffer is
947 a circular buffer, so if more than CONFIG_PRE_CON_BUF_SZ
948 bytes are output before the console is initialised, the
949 earlier bytes are discarded.
951 Note that when printing the buffer a copy is made on the
952 stack so CONFIG_PRE_CON_BUF_SZ must fit on the stack.
954 'Sane' compilers will generate smaller code if
955 CONFIG_PRE_CON_BUF_SZ is a power of 2
957 - Safe printf() functions
958 Define CONFIG_SYS_VSNPRINTF to compile in safe versions of
959 the printf() functions. These are defined in
960 include/vsprintf.h and include snprintf(), vsnprintf() and
961 so on. Code size increase is approximately 300-500 bytes.
962 If this option is not given then these functions will
963 silently discard their buffer size argument - this means
964 you are not getting any overflow checking in this case.
966 - Boot Delay: CONFIG_BOOTDELAY - in seconds
967 Delay before automatically booting the default image;
968 set to -1 to disable autoboot.
969 set to -2 to autoboot with no delay and not check for abort
970 (even when CONFIG_ZERO_BOOTDELAY_CHECK is defined).
972 See doc/README.autoboot for these options that
973 work with CONFIG_BOOTDELAY. None are required.
974 CONFIG_BOOT_RETRY_TIME
975 CONFIG_BOOT_RETRY_MIN
976 CONFIG_AUTOBOOT_KEYED
977 CONFIG_AUTOBOOT_PROMPT
978 CONFIG_AUTOBOOT_DELAY_STR
979 CONFIG_AUTOBOOT_STOP_STR
980 CONFIG_ZERO_BOOTDELAY_CHECK
981 CONFIG_RESET_TO_RETRY
985 Only needed when CONFIG_BOOTDELAY is enabled;
986 define a command string that is automatically executed
987 when no character is read on the console interface
988 within "Boot Delay" after reset.
991 This can be used to pass arguments to the bootm
992 command. The value of CONFIG_BOOTARGS goes into the
993 environment value "bootargs".
995 CONFIG_RAMBOOT and CONFIG_NFSBOOT
996 The value of these goes into the environment as
997 "ramboot" and "nfsboot" respectively, and can be used
998 as a convenience, when switching between booting from
1002 CONFIG_BOOTCOUNT_LIMIT
1003 Implements a mechanism for detecting a repeating reboot
1005 http://www.denx.de/wiki/view/DULG/UBootBootCountLimit
1007 CONFIG_BOOTCOUNT_ENV
1008 If no softreset save registers are found on the hardware
1009 "bootcount" is stored in the environment. To prevent a
1010 saveenv on all reboots, the environment variable
1011 "upgrade_available" is used. If "upgrade_available" is
1012 0, "bootcount" is always 0, if "upgrade_available" is
1013 1 "bootcount" is incremented in the environment.
1014 So the Userspace Applikation must set the "upgrade_available"
1015 and "bootcount" variable to 0, if a boot was successfully.
1017 - Pre-Boot Commands:
1020 When this option is #defined, the existence of the
1021 environment variable "preboot" will be checked
1022 immediately before starting the CONFIG_BOOTDELAY
1023 countdown and/or running the auto-boot command resp.
1024 entering interactive mode.
1026 This feature is especially useful when "preboot" is
1027 automatically generated or modified. For an example
1028 see the LWMON board specific code: here "preboot" is
1029 modified when the user holds down a certain
1030 combination of keys on the (special) keyboard when
1033 - Serial Download Echo Mode:
1035 If defined to 1, all characters received during a
1036 serial download (using the "loads" command) are
1037 echoed back. This might be needed by some terminal
1038 emulations (like "cu"), but may as well just take
1039 time on others. This setting #define's the initial
1040 value of the "loads_echo" environment variable.
1042 - Kgdb Serial Baudrate: (if CONFIG_CMD_KGDB is defined)
1043 CONFIG_KGDB_BAUDRATE
1044 Select one of the baudrates listed in
1045 CONFIG_SYS_BAUDRATE_TABLE, see below.
1047 - Monitor Functions:
1048 Monitor commands can be included or excluded
1049 from the build by using the #include files
1050 <config_cmd_all.h> and #undef'ing unwanted
1051 commands, or adding #define's for wanted commands.
1053 The default command configuration includes all commands
1054 except those marked below with a "*".
1056 CONFIG_CMD_AES AES 128 CBC encrypt/decrypt
1057 CONFIG_CMD_ASKENV * ask for env variable
1058 CONFIG_CMD_BDI bdinfo
1059 CONFIG_CMD_BEDBUG * Include BedBug Debugger
1060 CONFIG_CMD_BMP * BMP support
1061 CONFIG_CMD_BSP * Board specific commands
1062 CONFIG_CMD_BOOTD bootd
1063 CONFIG_CMD_BOOTI * ARM64 Linux kernel Image support
1064 CONFIG_CMD_CACHE * icache, dcache
1065 CONFIG_CMD_CLK * clock command support
1066 CONFIG_CMD_CONSOLE coninfo
1067 CONFIG_CMD_CRC32 * crc32
1068 CONFIG_CMD_DATE * support for RTC, date/time...
1069 CONFIG_CMD_DHCP * DHCP support
1070 CONFIG_CMD_DIAG * Diagnostics
1071 CONFIG_CMD_DS4510 * ds4510 I2C gpio commands
1072 CONFIG_CMD_DS4510_INFO * ds4510 I2C info command
1073 CONFIG_CMD_DS4510_MEM * ds4510 I2C eeprom/sram commansd
1074 CONFIG_CMD_DS4510_RST * ds4510 I2C rst command
1075 CONFIG_CMD_DTT * Digital Therm and Thermostat
1076 CONFIG_CMD_ECHO echo arguments
1077 CONFIG_CMD_EDITENV edit env variable
1078 CONFIG_CMD_EEPROM * EEPROM read/write support
1079 CONFIG_CMD_ELF * bootelf, bootvx
1080 CONFIG_CMD_ENV_CALLBACK * display details about env callbacks
1081 CONFIG_CMD_ENV_FLAGS * display details about env flags
1082 CONFIG_CMD_ENV_EXISTS * check existence of env variable
1083 CONFIG_CMD_EXPORTENV * export the environment
1084 CONFIG_CMD_EXT2 * ext2 command support
1085 CONFIG_CMD_EXT4 * ext4 command support
1086 CONFIG_CMD_FS_GENERIC * filesystem commands (e.g. load, ls)
1087 that work for multiple fs types
1088 CONFIG_CMD_FS_UUID * Look up a filesystem UUID
1089 CONFIG_CMD_SAVEENV saveenv
1090 CONFIG_CMD_FDC * Floppy Disk Support
1091 CONFIG_CMD_FAT * FAT command support
1092 CONFIG_CMD_FLASH flinfo, erase, protect
1093 CONFIG_CMD_FPGA FPGA device initialization support
1094 CONFIG_CMD_FUSE * Device fuse support
1095 CONFIG_CMD_GETTIME * Get time since boot
1096 CONFIG_CMD_GO * the 'go' command (exec code)
1097 CONFIG_CMD_GREPENV * search environment
1098 CONFIG_CMD_HASH * calculate hash / digest
1099 CONFIG_CMD_HWFLOW * RTS/CTS hw flow control
1100 CONFIG_CMD_I2C * I2C serial bus support
1101 CONFIG_CMD_IDE * IDE harddisk support
1102 CONFIG_CMD_IMI iminfo
1103 CONFIG_CMD_IMLS List all images found in NOR flash
1104 CONFIG_CMD_IMLS_NAND * List all images found in NAND flash
1105 CONFIG_CMD_IMMAP * IMMR dump support
1106 CONFIG_CMD_IOTRACE * I/O tracing for debugging
1107 CONFIG_CMD_IMPORTENV * import an environment
1108 CONFIG_CMD_INI * import data from an ini file into the env
1109 CONFIG_CMD_IRQ * irqinfo
1110 CONFIG_CMD_ITEST Integer/string test of 2 values
1111 CONFIG_CMD_JFFS2 * JFFS2 Support
1112 CONFIG_CMD_KGDB * kgdb
1113 CONFIG_CMD_LDRINFO * ldrinfo (display Blackfin loader)
1114 CONFIG_CMD_LINK_LOCAL * link-local IP address auto-configuration
1116 CONFIG_CMD_LOADB loadb
1117 CONFIG_CMD_LOADS loads
1118 CONFIG_CMD_MD5SUM * print md5 message digest
1119 (requires CONFIG_CMD_MEMORY and CONFIG_MD5)
1120 CONFIG_CMD_MEMINFO * Display detailed memory information
1121 CONFIG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base,
1123 CONFIG_CMD_MEMTEST * mtest
1124 CONFIG_CMD_MISC Misc functions like sleep etc
1125 CONFIG_CMD_MMC * MMC memory mapped support
1126 CONFIG_CMD_MII * MII utility commands
1127 CONFIG_CMD_MTDPARTS * MTD partition support
1128 CONFIG_CMD_NAND * NAND support
1129 CONFIG_CMD_NET bootp, tftpboot, rarpboot
1130 CONFIG_CMD_NFS NFS support
1131 CONFIG_CMD_PCA953X * PCA953x I2C gpio commands
1132 CONFIG_CMD_PCA953X_INFO * PCA953x I2C gpio info command
1133 CONFIG_CMD_PCI * pciinfo
1134 CONFIG_CMD_PCMCIA * PCMCIA support
1135 CONFIG_CMD_PING * send ICMP ECHO_REQUEST to network
1137 CONFIG_CMD_PORTIO * Port I/O
1138 CONFIG_CMD_READ * Read raw data from partition
1139 CONFIG_CMD_REGINFO * Register dump
1140 CONFIG_CMD_RUN run command in env variable
1141 CONFIG_CMD_SANDBOX * sb command to access sandbox features
1142 CONFIG_CMD_SAVES * save S record dump
1143 CONFIG_CMD_SCSI * SCSI Support
1144 CONFIG_CMD_SDRAM * print SDRAM configuration information
1145 (requires CONFIG_CMD_I2C)
1146 CONFIG_CMD_SETGETDCR Support for DCR Register access
1148 CONFIG_CMD_SF * Read/write/erase SPI NOR flash
1149 CONFIG_CMD_SHA1SUM * print sha1 memory digest
1150 (requires CONFIG_CMD_MEMORY)
1151 CONFIG_CMD_SOFTSWITCH * Soft switch setting command for BF60x
1152 CONFIG_CMD_SOURCE "source" command Support
1153 CONFIG_CMD_SPI * SPI serial bus support
1154 CONFIG_CMD_TFTPSRV * TFTP transfer in server mode
1155 CONFIG_CMD_TFTPPUT * TFTP put command (upload)
1156 CONFIG_CMD_TIME * run command and report execution time (ARM specific)
1157 CONFIG_CMD_TIMER * access to the system tick timer
1158 CONFIG_CMD_USB * USB support
1159 CONFIG_CMD_CDP * Cisco Discover Protocol support
1160 CONFIG_CMD_MFSL * Microblaze FSL support
1161 CONFIG_CMD_XIMG Load part of Multi Image
1162 CONFIG_CMD_UUID * Generate random UUID or GUID string
1164 EXAMPLE: If you want all functions except of network
1165 support you can write:
1167 #include "config_cmd_all.h"
1168 #undef CONFIG_CMD_NET
1171 fdt (flattened device tree) command: CONFIG_OF_LIBFDT
1173 Note: Don't enable the "icache" and "dcache" commands
1174 (configuration option CONFIG_CMD_CACHE) unless you know
1175 what you (and your U-Boot users) are doing. Data
1176 cache cannot be enabled on systems like the 8xx or
1177 8260 (where accesses to the IMMR region must be
1178 uncached), and it cannot be disabled on all other
1179 systems where we (mis-) use the data cache to hold an
1180 initial stack and some data.
1183 XXX - this list needs to get updated!
1185 - Regular expression support:
1187 If this variable is defined, U-Boot is linked against
1188 the SLRE (Super Light Regular Expression) library,
1189 which adds regex support to some commands, as for
1190 example "env grep" and "setexpr".
1194 If this variable is defined, U-Boot will use a device tree
1195 to configure its devices, instead of relying on statically
1196 compiled #defines in the board file. This option is
1197 experimental and only available on a few boards. The device
1198 tree is available in the global data as gd->fdt_blob.
1200 U-Boot needs to get its device tree from somewhere. This can
1201 be done using one of the two options below:
1204 If this variable is defined, U-Boot will embed a device tree
1205 binary in its image. This device tree file should be in the
1206 board directory and called <soc>-<board>.dts. The binary file
1207 is then picked up in board_init_f() and made available through
1208 the global data structure as gd->blob.
1211 If this variable is defined, U-Boot will build a device tree
1212 binary. It will be called u-boot.dtb. Architecture-specific
1213 code will locate it at run-time. Generally this works by:
1215 cat u-boot.bin u-boot.dtb >image.bin
1217 and in fact, U-Boot does this for you, creating a file called
1218 u-boot-dtb.bin which is useful in the common case. You can
1219 still use the individual files if you need something more
1224 If this variable is defined, it enables watchdog
1225 support for the SoC. There must be support in the SoC
1226 specific code for a watchdog. For the 8xx and 8260
1227 CPUs, the SIU Watchdog feature is enabled in the SYPCR
1228 register. When supported for a specific SoC is
1229 available, then no further board specific code should
1230 be needed to use it.
1233 When using a watchdog circuitry external to the used
1234 SoC, then define this variable and provide board
1235 specific code for the "hw_watchdog_reset" function.
1237 CONFIG_AT91_HW_WDT_TIMEOUT
1238 specify the timeout in seconds. default 2 seconds.
1241 CONFIG_VERSION_VARIABLE
1242 If this variable is defined, an environment variable
1243 named "ver" is created by U-Boot showing the U-Boot
1244 version as printed by the "version" command.
1245 Any change to this variable will be reverted at the
1250 When CONFIG_CMD_DATE is selected, the type of the RTC
1251 has to be selected, too. Define exactly one of the
1254 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx
1255 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC
1256 CONFIG_RTC_MC13XXX - use MC13783 or MC13892 RTC
1257 CONFIG_RTC_MC146818 - use MC146818 RTC
1258 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC
1259 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC
1260 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC
1261 CONFIG_RTC_DS1339 - use Maxim, Inc. DS1339 RTC
1262 CONFIG_RTC_DS164x - use Dallas DS164x RTC
1263 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC
1264 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC
1265 CONFIG_SYS_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337
1266 CONFIG_SYS_RV3029_TCR - enable trickle charger on
1269 Note that if the RTC uses I2C, then the I2C interface
1270 must also be configured. See I2C Support, below.
1273 CONFIG_PCA953X - use NXP's PCA953X series I2C GPIO
1275 The CONFIG_SYS_I2C_PCA953X_WIDTH option specifies a list of
1276 chip-ngpio pairs that tell the PCA953X driver the number of
1277 pins supported by a particular chip.
1279 Note that if the GPIO device uses I2C, then the I2C interface
1280 must also be configured. See I2C Support, below.
1283 When CONFIG_IO_TRACE is selected, U-Boot intercepts all I/O
1284 accesses and can checksum them or write a list of them out
1285 to memory. See the 'iotrace' command for details. This is
1286 useful for testing device drivers since it can confirm that
1287 the driver behaves the same way before and after a code
1288 change. Currently this is supported on sandbox and arm. To
1289 add support for your architecture, add '#include <iotrace.h>'
1290 to the bottom of arch/<arch>/include/asm/io.h and test.
1292 Example output from the 'iotrace stats' command is below.
1293 Note that if the trace buffer is exhausted, the checksum will
1294 still continue to operate.
1297 Start: 10000000 (buffer start address)
1298 Size: 00010000 (buffer size)
1299 Offset: 00000120 (current buffer offset)
1300 Output: 10000120 (start + offset)
1301 Count: 00000018 (number of trace records)
1302 CRC32: 9526fb66 (CRC32 of all trace records)
1304 - Timestamp Support:
1306 When CONFIG_TIMESTAMP is selected, the timestamp
1307 (date and time) of an image is printed by image
1308 commands like bootm or iminfo. This option is
1309 automatically enabled when you select CONFIG_CMD_DATE .
1311 - Partition Labels (disklabels) Supported:
1312 Zero or more of the following:
1313 CONFIG_MAC_PARTITION Apple's MacOS partition table.
1314 CONFIG_DOS_PARTITION MS Dos partition table, traditional on the
1315 Intel architecture, USB sticks, etc.
1316 CONFIG_ISO_PARTITION ISO partition table, used on CDROM etc.
1317 CONFIG_EFI_PARTITION GPT partition table, common when EFI is the
1318 bootloader. Note 2TB partition limit; see
1320 CONFIG_MTD_PARTITIONS Memory Technology Device partition table.
1322 If IDE or SCSI support is enabled (CONFIG_CMD_IDE or
1323 CONFIG_CMD_SCSI) you must configure support for at
1324 least one non-MTD partition type as well.
1327 CONFIG_IDE_RESET_ROUTINE - this is defined in several
1328 board configurations files but used nowhere!
1330 CONFIG_IDE_RESET - is this is defined, IDE Reset will
1331 be performed by calling the function
1332 ide_set_reset(int reset)
1333 which has to be defined in a board specific file
1338 Set this to enable ATAPI support.
1343 Set this to enable support for disks larger than 137GB
1344 Also look at CONFIG_SYS_64BIT_LBA.
1345 Whithout these , LBA48 support uses 32bit variables and will 'only'
1346 support disks up to 2.1TB.
1348 CONFIG_SYS_64BIT_LBA:
1349 When enabled, makes the IDE subsystem use 64bit sector addresses.
1353 At the moment only there is only support for the
1354 SYM53C8XX SCSI controller; define
1355 CONFIG_SCSI_SYM53C8XX to enable it.
1357 CONFIG_SYS_SCSI_MAX_LUN [8], CONFIG_SYS_SCSI_MAX_SCSI_ID [7] and
1358 CONFIG_SYS_SCSI_MAX_DEVICE [CONFIG_SYS_SCSI_MAX_SCSI_ID *
1359 CONFIG_SYS_SCSI_MAX_LUN] can be adjusted to define the
1360 maximum numbers of LUNs, SCSI ID's and target
1362 CONFIG_SYS_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz)
1364 The environment variable 'scsidevs' is set to the number of
1365 SCSI devices found during the last scan.
1367 - NETWORK Support (PCI):
1369 Support for Intel 8254x/8257x gigabit chips.
1372 Utility code for direct access to the SPI bus on Intel 8257x.
1373 This does not do anything useful unless you set at least one
1374 of CONFIG_CMD_E1000 or CONFIG_E1000_SPI_GENERIC.
1376 CONFIG_E1000_SPI_GENERIC
1377 Allow generic access to the SPI bus on the Intel 8257x, for
1378 example with the "sspi" command.
1381 Management command for E1000 devices. When used on devices
1382 with SPI support you can reprogram the EEPROM from U-Boot.
1384 CONFIG_E1000_FALLBACK_MAC
1385 default MAC for empty EEPROM after production.
1388 Support for Intel 82557/82559/82559ER chips.
1389 Optional CONFIG_EEPRO100_SROM_WRITE enables EEPROM
1390 write routine for first time initialisation.
1393 Support for Digital 2114x chips.
1394 Optional CONFIG_TULIP_SELECT_MEDIA for board specific
1395 modem chip initialisation (KS8761/QS6611).
1398 Support for National dp83815 chips.
1401 Support for National dp8382[01] gigabit chips.
1403 - NETWORK Support (other):
1405 CONFIG_DRIVER_AT91EMAC
1406 Support for AT91RM9200 EMAC.
1409 Define this to use reduced MII inteface
1411 CONFIG_DRIVER_AT91EMAC_QUIET
1412 If this defined, the driver is quiet.
1413 The driver doen't show link status messages.
1415 CONFIG_CALXEDA_XGMAC
1416 Support for the Calxeda XGMAC device
1419 Support for SMSC's LAN91C96 chips.
1421 CONFIG_LAN91C96_BASE
1422 Define this to hold the physical address
1423 of the LAN91C96's I/O space
1425 CONFIG_LAN91C96_USE_32_BIT
1426 Define this to enable 32 bit addressing
1429 Support for SMSC's LAN91C111 chip
1431 CONFIG_SMC91111_BASE
1432 Define this to hold the physical address
1433 of the device (I/O space)
1435 CONFIG_SMC_USE_32_BIT
1436 Define this if data bus is 32 bits
1438 CONFIG_SMC_USE_IOFUNCS
1439 Define this to use i/o functions instead of macros
1440 (some hardware wont work with macros)
1442 CONFIG_DRIVER_TI_EMAC
1443 Support for davinci emac
1445 CONFIG_SYS_DAVINCI_EMAC_PHY_COUNT
1446 Define this if you have more then 3 PHYs.
1449 Support for Faraday's FTGMAC100 Gigabit SoC Ethernet
1451 CONFIG_FTGMAC100_EGIGA
1452 Define this to use GE link update with gigabit PHY.
1453 Define this if FTGMAC100 is connected to gigabit PHY.
1454 If your system has 10/100 PHY only, it might not occur
1455 wrong behavior. Because PHY usually return timeout or
1456 useless data when polling gigabit status and gigabit
1457 control registers. This behavior won't affect the
1458 correctnessof 10/100 link speed update.
1461 Support for SMSC's LAN911x and LAN921x chips
1464 Define this to hold the physical address
1465 of the device (I/O space)
1467 CONFIG_SMC911X_32_BIT
1468 Define this if data bus is 32 bits
1470 CONFIG_SMC911X_16_BIT
1471 Define this if data bus is 16 bits. If your processor
1472 automatically converts one 32 bit word to two 16 bit
1473 words you may also try CONFIG_SMC911X_32_BIT.
1476 Support for Renesas on-chip Ethernet controller
1478 CONFIG_SH_ETHER_USE_PORT
1479 Define the number of ports to be used
1481 CONFIG_SH_ETHER_PHY_ADDR
1482 Define the ETH PHY's address
1484 CONFIG_SH_ETHER_CACHE_WRITEBACK
1485 If this option is set, the driver enables cache flush.
1489 Support for PWM modul on the imx6.
1493 Support TPM devices.
1496 Support for i2c bus TPM devices. Only one device
1497 per system is supported at this time.
1499 CONFIG_TPM_TIS_I2C_BUS_NUMBER
1500 Define the the i2c bus number for the TPM device
1502 CONFIG_TPM_TIS_I2C_SLAVE_ADDRESS
1503 Define the TPM's address on the i2c bus
1505 CONFIG_TPM_TIS_I2C_BURST_LIMITATION
1506 Define the burst count bytes upper limit
1508 CONFIG_TPM_ATMEL_TWI
1509 Support for Atmel TWI TPM device. Requires I2C support.
1512 Support for generic parallel port TPM devices. Only one device
1513 per system is supported at this time.
1515 CONFIG_TPM_TIS_BASE_ADDRESS
1516 Base address where the generic TPM device is mapped
1517 to. Contemporary x86 systems usually map it at
1521 Add tpm monitor functions.
1522 Requires CONFIG_TPM. If CONFIG_TPM_AUTH_SESSIONS is set, also
1523 provides monitor access to authorized functions.
1526 Define this to enable the TPM support library which provides
1527 functional interfaces to some TPM commands.
1528 Requires support for a TPM device.
1530 CONFIG_TPM_AUTH_SESSIONS
1531 Define this to enable authorized functions in the TPM library.
1532 Requires CONFIG_TPM and CONFIG_SHA1.
1535 At the moment only the UHCI host controller is
1536 supported (PIP405, MIP405, MPC5200); define
1537 CONFIG_USB_UHCI to enable it.
1538 define CONFIG_USB_KEYBOARD to enable the USB Keyboard
1539 and define CONFIG_USB_STORAGE to enable the USB
1542 Supported are USB Keyboards and USB Floppy drives
1544 MPC5200 USB requires additional defines:
1546 for 528 MHz Clock: 0x0001bbbb
1550 for differential drivers: 0x00001000
1551 for single ended drivers: 0x00005000
1552 for differential drivers on PSC3: 0x00000100
1553 for single ended drivers on PSC3: 0x00004100
1554 CONFIG_SYS_USB_EVENT_POLL
1555 May be defined to allow interrupt polling
1556 instead of using asynchronous interrupts
1558 CONFIG_USB_EHCI_TXFIFO_THRESH enables setting of the
1559 txfilltuning field in the EHCI controller on reset.
1561 CONFIG_USB_DWC2_REG_ADDR the physical CPU address of the DWC2
1562 HW module registers.
1565 Define the below if you wish to use the USB console.
1566 Once firmware is rebuilt from a serial console issue the
1567 command "setenv stdin usbtty; setenv stdout usbtty" and
1568 attach your USB cable. The Unix command "dmesg" should print
1569 it has found a new device. The environment variable usbtty
1570 can be set to gserial or cdc_acm to enable your device to
1571 appear to a USB host as a Linux gserial device or a
1572 Common Device Class Abstract Control Model serial device.
1573 If you select usbtty = gserial you should be able to enumerate
1575 # modprobe usbserial vendor=0xVendorID product=0xProductID
1576 else if using cdc_acm, simply setting the environment
1577 variable usbtty to be cdc_acm should suffice. The following
1578 might be defined in YourBoardName.h
1581 Define this to build a UDC device
1584 Define this to have a tty type of device available to
1585 talk to the UDC device
1588 Define this to enable the high speed support for usb
1589 device and usbtty. If this feature is enabled, a routine
1590 int is_usbd_high_speed(void)
1591 also needs to be defined by the driver to dynamically poll
1592 whether the enumeration has succeded at high speed or full
1595 CONFIG_SYS_CONSOLE_IS_IN_ENV
1596 Define this if you want stdin, stdout &/or stderr to
1600 CONFIG_SYS_USB_EXTC_CLK 0xBLAH
1601 Derive USB clock from external clock "blah"
1602 - CONFIG_SYS_USB_EXTC_CLK 0x02
1604 CONFIG_SYS_USB_BRG_CLK 0xBLAH
1605 Derive USB clock from brgclk
1606 - CONFIG_SYS_USB_BRG_CLK 0x04
1608 If you have a USB-IF assigned VendorID then you may wish to
1609 define your own vendor specific values either in BoardName.h
1610 or directly in usbd_vendor_info.h. If you don't define
1611 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME,
1612 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot
1613 should pretend to be a Linux device to it's target host.
1615 CONFIG_USBD_MANUFACTURER
1616 Define this string as the name of your company for
1617 - CONFIG_USBD_MANUFACTURER "my company"
1619 CONFIG_USBD_PRODUCT_NAME
1620 Define this string as the name of your product
1621 - CONFIG_USBD_PRODUCT_NAME "acme usb device"
1623 CONFIG_USBD_VENDORID
1624 Define this as your assigned Vendor ID from the USB
1625 Implementors Forum. This *must* be a genuine Vendor ID
1626 to avoid polluting the USB namespace.
1627 - CONFIG_USBD_VENDORID 0xFFFF
1629 CONFIG_USBD_PRODUCTID
1630 Define this as the unique Product ID
1632 - CONFIG_USBD_PRODUCTID 0xFFFF
1634 - ULPI Layer Support:
1635 The ULPI (UTMI Low Pin (count) Interface) PHYs are supported via
1636 the generic ULPI layer. The generic layer accesses the ULPI PHY
1637 via the platform viewport, so you need both the genric layer and
1638 the viewport enabled. Currently only Chipidea/ARC based
1639 viewport is supported.
1640 To enable the ULPI layer support, define CONFIG_USB_ULPI and
1641 CONFIG_USB_ULPI_VIEWPORT in your board configuration file.
1642 If your ULPI phy needs a different reference clock than the
1643 standard 24 MHz then you have to define CONFIG_ULPI_REF_CLK to
1644 the appropriate value in Hz.
1647 The MMC controller on the Intel PXA is supported. To
1648 enable this define CONFIG_MMC. The MMC can be
1649 accessed from the boot prompt by mapping the device
1650 to physical memory similar to flash. Command line is
1651 enabled with CONFIG_CMD_MMC. The MMC driver also works with
1652 the FAT fs. This is enabled with CONFIG_CMD_FAT.
1655 Support for Renesas on-chip MMCIF controller
1657 CONFIG_SH_MMCIF_ADDR
1658 Define the base address of MMCIF registers
1661 Define the clock frequency for MMCIF
1664 Enable the generic MMC driver
1666 CONFIG_SUPPORT_EMMC_BOOT
1667 Enable some additional features of the eMMC boot partitions.
1669 CONFIG_SUPPORT_EMMC_RPMB
1670 Enable the commands for reading, writing and programming the
1671 key for the Replay Protection Memory Block partition in eMMC.
1673 - USB Device Firmware Update (DFU) class support:
1675 This enables the USB portion of the DFU USB class
1678 This enables the command "dfu" which is used to have
1679 U-Boot create a DFU class device via USB. This command
1680 requires that the "dfu_alt_info" environment variable be
1681 set and define the alt settings to expose to the host.
1684 This enables support for exposing (e)MMC devices via DFU.
1687 This enables support for exposing NAND devices via DFU.
1690 This enables support for exposing RAM via DFU.
1691 Note: DFU spec refer to non-volatile memory usage, but
1692 allow usages beyond the scope of spec - here RAM usage,
1693 one that would help mostly the developer.
1695 CONFIG_SYS_DFU_DATA_BUF_SIZE
1696 Dfu transfer uses a buffer before writing data to the
1697 raw storage device. Make the size (in bytes) of this buffer
1698 configurable. The size of this buffer is also configurable
1699 through the "dfu_bufsiz" environment variable.
1701 CONFIG_SYS_DFU_MAX_FILE_SIZE
1702 When updating files rather than the raw storage device,
1703 we use a static buffer to copy the file into and then write
1704 the buffer once we've been given the whole file. Define
1705 this to the maximum filesize (in bytes) for the buffer.
1706 Default is 4 MiB if undefined.
1708 DFU_DEFAULT_POLL_TIMEOUT
1709 Poll timeout [ms], is the timeout a device can send to the
1710 host. The host must wait for this timeout before sending
1711 a subsequent DFU_GET_STATUS request to the device.
1713 DFU_MANIFEST_POLL_TIMEOUT
1714 Poll timeout [ms], which the device sends to the host when
1715 entering dfuMANIFEST state. Host waits this timeout, before
1716 sending again an USB request to the device.
1718 - USB Device Android Fastboot support:
1720 This enables the command "fastboot" which enables the Android
1721 fastboot mode for the platform's USB device. Fastboot is a USB
1722 protocol for downloading images, flashing and device control
1723 used on Android devices.
1724 See doc/README.android-fastboot for more information.
1726 CONFIG_ANDROID_BOOT_IMAGE
1727 This enables support for booting images which use the Android
1728 image format header.
1730 CONFIG_USB_FASTBOOT_BUF_ADDR
1731 The fastboot protocol requires a large memory buffer for
1732 downloads. Define this to the starting RAM address to use for
1735 CONFIG_USB_FASTBOOT_BUF_SIZE
1736 The fastboot protocol requires a large memory buffer for
1737 downloads. This buffer should be as large as possible for a
1738 platform. Define this to the size available RAM for fastboot.
1740 CONFIG_FASTBOOT_FLASH
1741 The fastboot protocol includes a "flash" command for writing
1742 the downloaded image to a non-volatile storage device. Define
1743 this to enable the "fastboot flash" command.
1745 CONFIG_FASTBOOT_FLASH_MMC_DEV
1746 The fastboot "flash" command requires additional information
1747 regarding the non-volatile storage device. Define this to
1748 the eMMC device that fastboot should use to store the image.
1750 CONFIG_FASTBOOT_GPT_NAME
1751 The fastboot "flash" command supports writing the downloaded
1752 image to the Protective MBR and the Primary GUID Partition
1753 Table. (Additionally, this downloaded image is post-processed
1754 to generate and write the Backup GUID Partition Table.)
1755 This occurs when the specified "partition name" on the
1756 "fastboot flash" command line matches this value.
1757 Default is GPT_ENTRY_NAME (currently "gpt") if undefined.
1759 - Journaling Flash filesystem support:
1760 CONFIG_JFFS2_NAND, CONFIG_JFFS2_NAND_OFF, CONFIG_JFFS2_NAND_SIZE,
1761 CONFIG_JFFS2_NAND_DEV
1762 Define these for a default partition on a NAND device
1764 CONFIG_SYS_JFFS2_FIRST_SECTOR,
1765 CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS
1766 Define these for a default partition on a NOR device
1768 CONFIG_SYS_JFFS_CUSTOM_PART
1769 Define this to create an own partition. You have to provide a
1770 function struct part_info* jffs2_part_info(int part_num)
1772 If you define only one JFFS2 partition you may also want to
1773 #define CONFIG_SYS_JFFS_SINGLE_PART 1
1774 to disable the command chpart. This is the default when you
1775 have not defined a custom partition
1777 - FAT(File Allocation Table) filesystem write function support:
1780 Define this to enable support for saving memory data as a
1781 file in FAT formatted partition.
1783 This will also enable the command "fatwrite" enabling the
1784 user to write files to FAT.
1786 CBFS (Coreboot Filesystem) support
1789 Define this to enable support for reading from a Coreboot
1790 filesystem. Available commands are cbfsinit, cbfsinfo, cbfsls
1793 - FAT(File Allocation Table) filesystem cluster size:
1794 CONFIG_FS_FAT_MAX_CLUSTSIZE
1796 Define the max cluster size for fat operations else
1797 a default value of 65536 will be defined.
1802 Define this to enable standard (PC-Style) keyboard
1806 Standard PC keyboard driver with US (is default) and
1807 GERMAN key layout (switch via environment 'keymap=de') support.
1808 Export function i8042_kbd_init, i8042_tstc and i8042_getc
1809 for cfb_console. Supports cursor blinking.
1812 Enables a Chrome OS keyboard using the CROS_EC interface.
1813 This uses CROS_EC to communicate with a second microcontroller
1814 which provides key scans on request.
1819 Define this to enable video support (for output to
1822 CONFIG_VIDEO_CT69000
1824 Enable Chips & Technologies 69000 Video chip
1826 CONFIG_VIDEO_SMI_LYNXEM
1827 Enable Silicon Motion SMI 712/710/810 Video chip. The
1828 video output is selected via environment 'videoout'
1829 (1 = LCD and 2 = CRT). If videoout is undefined, CRT is
1832 For the CT69000 and SMI_LYNXEM drivers, videomode is
1833 selected via environment 'videomode'. Two different ways
1835 - "videomode=num" 'num' is a standard LiLo mode numbers.
1836 Following standard modes are supported (* is default):
1838 Colors 640x480 800x600 1024x768 1152x864 1280x1024
1839 -------------+---------------------------------------------
1840 8 bits | 0x301* 0x303 0x305 0x161 0x307
1841 15 bits | 0x310 0x313 0x316 0x162 0x319
1842 16 bits | 0x311 0x314 0x317 0x163 0x31A
1843 24 bits | 0x312 0x315 0x318 ? 0x31B
1844 -------------+---------------------------------------------
1845 (i.e. setenv videomode 317; saveenv; reset;)
1847 - "videomode=bootargs" all the video parameters are parsed
1848 from the bootargs. (See drivers/video/videomodes.c)
1851 CONFIG_VIDEO_SED13806
1852 Enable Epson SED13806 driver. This driver supports 8bpp
1853 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP
1854 or CONFIG_VIDEO_SED13806_16BPP
1857 Enable the Freescale DIU video driver. Reference boards for
1858 SOCs that have a DIU should define this macro to enable DIU
1859 support, and should also define these other macros:
1865 CONFIG_VIDEO_SW_CURSOR
1866 CONFIG_VGA_AS_SINGLE_DEVICE
1868 CONFIG_VIDEO_BMP_LOGO
1870 The DIU driver will look for the 'video-mode' environment
1871 variable, and if defined, enable the DIU as a console during
1872 boot. See the documentation file README.video for a
1873 description of this variable.
1879 Define this to enable a custom keyboard support.
1880 This simply calls drv_keyboard_init() which must be
1881 defined in your board-specific files.
1882 The only board using this so far is RBC823.
1884 - LCD Support: CONFIG_LCD
1886 Define this to enable LCD support (for output to LCD
1887 display); also select one of the supported displays
1888 by defining one of these:
1892 HITACHI TX09D70VM1CCA, 3.5", 240x320.
1894 CONFIG_NEC_NL6448AC33:
1896 NEC NL6448AC33-18. Active, color, single scan.
1898 CONFIG_NEC_NL6448BC20
1900 NEC NL6448BC20-08. 6.5", 640x480.
1901 Active, color, single scan.
1903 CONFIG_NEC_NL6448BC33_54
1905 NEC NL6448BC33-54. 10.4", 640x480.
1906 Active, color, single scan.
1910 Sharp 320x240. Active, color, single scan.
1911 It isn't 16x9, and I am not sure what it is.
1913 CONFIG_SHARP_LQ64D341
1915 Sharp LQ64D341 display, 640x480.
1916 Active, color, single scan.
1920 HLD1045 display, 640x480.
1921 Active, color, single scan.
1925 Optrex CBL50840-2 NF-FW 99 22 M5
1927 Hitachi LMG6912RPFC-00T
1931 320x240. Black & white.
1933 Normally display is black on white background; define
1934 CONFIG_SYS_WHITE_ON_BLACK to get it inverted.
1936 CONFIG_LCD_ALIGNMENT
1938 Normally the LCD is page-aligned (typically 4KB). If this is
1939 defined then the LCD will be aligned to this value instead.
1940 For ARM it is sometimes useful to use MMU_SECTION_SIZE
1941 here, since it is cheaper to change data cache settings on
1942 a per-section basis.
1944 CONFIG_CONSOLE_SCROLL_LINES
1946 When the console need to be scrolled, this is the number of
1947 lines to scroll by. It defaults to 1. Increasing this makes
1948 the console jump but can help speed up operation when scrolling
1953 Sometimes, for example if the display is mounted in portrait
1954 mode or even if it's mounted landscape but rotated by 180degree,
1955 we need to rotate our content of the display relative to the
1956 framebuffer, so that user can read the messages which are
1958 Once CONFIG_LCD_ROTATION is defined, the lcd_console will be
1959 initialized with a given rotation from "vl_rot" out of
1960 "vidinfo_t" which is provided by the board specific code.
1961 The value for vl_rot is coded as following (matching to
1962 fbcon=rotate:<n> linux-kernel commandline):
1963 0 = no rotation respectively 0 degree
1964 1 = 90 degree rotation
1965 2 = 180 degree rotation
1966 3 = 270 degree rotation
1968 If CONFIG_LCD_ROTATION is not defined, the console will be
1969 initialized with 0degree rotation.
1973 Support drawing of RLE8-compressed bitmaps on the LCD.
1977 Enables an 'i2c edid' command which can read EDID
1978 information over I2C from an attached LCD display.
1980 - Splash Screen Support: CONFIG_SPLASH_SCREEN
1982 If this option is set, the environment is checked for
1983 a variable "splashimage". If found, the usual display
1984 of logo, copyright and system information on the LCD
1985 is suppressed and the BMP image at the address
1986 specified in "splashimage" is loaded instead. The
1987 console is redirected to the "nulldev", too. This
1988 allows for a "silent" boot where a splash screen is
1989 loaded very quickly after power-on.
1991 CONFIG_SPLASHIMAGE_GUARD
1993 If this option is set, then U-Boot will prevent the environment
1994 variable "splashimage" from being set to a problematic address
1995 (see README.displaying-bmps).
1996 This option is useful for targets where, due to alignment
1997 restrictions, an improperly aligned BMP image will cause a data
1998 abort. If you think you will not have problems with unaligned
1999 accesses (for example because your toolchain prevents them)
2000 there is no need to set this option.
2002 CONFIG_SPLASH_SCREEN_ALIGN
2004 If this option is set the splash image can be freely positioned
2005 on the screen. Environment variable "splashpos" specifies the
2006 position as "x,y". If a positive number is given it is used as
2007 number of pixel from left/top. If a negative number is given it
2008 is used as number of pixel from right/bottom. You can also
2009 specify 'm' for centering the image.
2012 setenv splashpos m,m
2013 => image at center of screen
2015 setenv splashpos 30,20
2016 => image at x = 30 and y = 20
2018 setenv splashpos -10,m
2019 => vertically centered image
2020 at x = dspWidth - bmpWidth - 9
2022 - Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP
2024 If this option is set, additionally to standard BMP
2025 images, gzipped BMP images can be displayed via the
2026 splashscreen support or the bmp command.
2028 - Run length encoded BMP image (RLE8) support: CONFIG_VIDEO_BMP_RLE8
2030 If this option is set, 8-bit RLE compressed BMP images
2031 can be displayed via the splashscreen support or the
2034 - Do compressing for memory range:
2037 If this option is set, it would use zlib deflate method
2038 to compress the specified memory at its best effort.
2040 - Compression support:
2043 Enabled by default to support gzip compressed images.
2047 If this option is set, support for bzip2 compressed
2048 images is included. If not, only uncompressed and gzip
2049 compressed images are supported.
2051 NOTE: the bzip2 algorithm requires a lot of RAM, so
2052 the malloc area (as defined by CONFIG_SYS_MALLOC_LEN) should
2057 If this option is set, support for lzma compressed
2060 Note: The LZMA algorithm adds between 2 and 4KB of code and it
2061 requires an amount of dynamic memory that is given by the
2064 (1846 + 768 << (lc + lp)) * sizeof(uint16)
2066 Where lc and lp stand for, respectively, Literal context bits
2067 and Literal pos bits.
2069 This value is upper-bounded by 14MB in the worst case. Anyway,
2070 for a ~4MB large kernel image, we have lc=3 and lp=0 for a
2071 total amount of (1846 + 768 << (3 + 0)) * 2 = ~41KB... that is
2072 a very small buffer.
2074 Use the lzmainfo tool to determinate the lc and lp values and
2075 then calculate the amount of needed dynamic memory (ensuring
2076 the appropriate CONFIG_SYS_MALLOC_LEN value).
2080 If this option is set, support for LZO compressed images
2086 The address of PHY on MII bus.
2088 CONFIG_PHY_CLOCK_FREQ (ppc4xx)
2090 The clock frequency of the MII bus
2094 If this option is set, support for speed/duplex
2095 detection of gigabit PHY is included.
2097 CONFIG_PHY_RESET_DELAY
2099 Some PHY like Intel LXT971A need extra delay after
2100 reset before any MII register access is possible.
2101 For such PHY, set this option to the usec delay
2102 required. (minimum 300usec for LXT971A)
2104 CONFIG_PHY_CMD_DELAY (ppc4xx)
2106 Some PHY like Intel LXT971A need extra delay after
2107 command issued before MII status register can be read
2112 Define a default value for the IP address to use for
2113 the default Ethernet interface, in case this is not
2114 determined through e.g. bootp.
2115 (Environment variable "ipaddr")
2117 - Server IP address:
2120 Defines a default value for the IP address of a TFTP
2121 server to contact when using the "tftboot" command.
2122 (Environment variable "serverip")
2124 CONFIG_KEEP_SERVERADDR
2126 Keeps the server's MAC address, in the env 'serveraddr'
2127 for passing to bootargs (like Linux's netconsole option)
2129 - Gateway IP address:
2132 Defines a default value for the IP address of the
2133 default router where packets to other networks are
2135 (Environment variable "gatewayip")
2140 Defines a default value for the subnet mask (or
2141 routing prefix) which is used to determine if an IP
2142 address belongs to the local subnet or needs to be
2143 forwarded through a router.
2144 (Environment variable "netmask")
2146 - Multicast TFTP Mode:
2149 Defines whether you want to support multicast TFTP as per
2150 rfc-2090; for example to work with atftp. Lets lots of targets
2151 tftp down the same boot image concurrently. Note: the Ethernet
2152 driver in use must provide a function: mcast() to join/leave a
2155 - BOOTP Recovery Mode:
2156 CONFIG_BOOTP_RANDOM_DELAY
2158 If you have many targets in a network that try to
2159 boot using BOOTP, you may want to avoid that all
2160 systems send out BOOTP requests at precisely the same
2161 moment (which would happen for instance at recovery
2162 from a power failure, when all systems will try to
2163 boot, thus flooding the BOOTP server. Defining
2164 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
2165 inserted before sending out BOOTP requests. The
2166 following delays are inserted then:
2168 1st BOOTP request: delay 0 ... 1 sec
2169 2nd BOOTP request: delay 0 ... 2 sec
2170 3rd BOOTP request: delay 0 ... 4 sec
2172 BOOTP requests: delay 0 ... 8 sec
2174 CONFIG_BOOTP_ID_CACHE_SIZE
2176 BOOTP packets are uniquely identified using a 32-bit ID. The
2177 server will copy the ID from client requests to responses and
2178 U-Boot will use this to determine if it is the destination of
2179 an incoming response. Some servers will check that addresses
2180 aren't in use before handing them out (usually using an ARP
2181 ping) and therefore take up to a few hundred milliseconds to
2182 respond. Network congestion may also influence the time it
2183 takes for a response to make it back to the client. If that
2184 time is too long, U-Boot will retransmit requests. In order
2185 to allow earlier responses to still be accepted after these
2186 retransmissions, U-Boot's BOOTP client keeps a small cache of
2187 IDs. The CONFIG_BOOTP_ID_CACHE_SIZE controls the size of this
2188 cache. The default is to keep IDs for up to four outstanding
2189 requests. Increasing this will allow U-Boot to accept offers
2190 from a BOOTP client in networks with unusually high latency.
2192 - DHCP Advanced Options:
2193 You can fine tune the DHCP functionality by defining
2194 CONFIG_BOOTP_* symbols:
2196 CONFIG_BOOTP_SUBNETMASK
2197 CONFIG_BOOTP_GATEWAY
2198 CONFIG_BOOTP_HOSTNAME
2199 CONFIG_BOOTP_NISDOMAIN
2200 CONFIG_BOOTP_BOOTPATH
2201 CONFIG_BOOTP_BOOTFILESIZE
2204 CONFIG_BOOTP_SEND_HOSTNAME
2205 CONFIG_BOOTP_NTPSERVER
2206 CONFIG_BOOTP_TIMEOFFSET
2207 CONFIG_BOOTP_VENDOREX
2208 CONFIG_BOOTP_MAY_FAIL
2210 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip
2211 environment variable, not the BOOTP server.
2213 CONFIG_BOOTP_MAY_FAIL - If the DHCP server is not found
2214 after the configured retry count, the call will fail
2215 instead of starting over. This can be used to fail over
2216 to Link-local IP address configuration if the DHCP server
2219 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS
2220 serverip from a DHCP server, it is possible that more
2221 than one DNS serverip is offered to the client.
2222 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS
2223 serverip will be stored in the additional environment
2224 variable "dnsip2". The first DNS serverip is always
2225 stored in the variable "dnsip", when CONFIG_BOOTP_DNS
2228 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable
2229 to do a dynamic update of a DNS server. To do this, they
2230 need the hostname of the DHCP requester.
2231 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content
2232 of the "hostname" environment variable is passed as
2233 option 12 to the DHCP server.
2235 CONFIG_BOOTP_DHCP_REQUEST_DELAY
2237 A 32bit value in microseconds for a delay between
2238 receiving a "DHCP Offer" and sending the "DHCP Request".
2239 This fixes a problem with certain DHCP servers that don't
2240 respond 100% of the time to a "DHCP request". E.g. On an
2241 AT91RM9200 processor running at 180MHz, this delay needed
2242 to be *at least* 15,000 usec before a Windows Server 2003
2243 DHCP server would reply 100% of the time. I recommend at
2244 least 50,000 usec to be safe. The alternative is to hope
2245 that one of the retries will be successful but note that
2246 the DHCP timeout and retry process takes a longer than
2249 - Link-local IP address negotiation:
2250 Negotiate with other link-local clients on the local network
2251 for an address that doesn't require explicit configuration.
2252 This is especially useful if a DHCP server cannot be guaranteed
2253 to exist in all environments that the device must operate.
2255 See doc/README.link-local for more information.
2258 CONFIG_CDP_DEVICE_ID
2260 The device id used in CDP trigger frames.
2262 CONFIG_CDP_DEVICE_ID_PREFIX
2264 A two character string which is prefixed to the MAC address
2269 A printf format string which contains the ascii name of
2270 the port. Normally is set to "eth%d" which sets
2271 eth0 for the first Ethernet, eth1 for the second etc.
2273 CONFIG_CDP_CAPABILITIES
2275 A 32bit integer which indicates the device capabilities;
2276 0x00000010 for a normal host which does not forwards.
2280 An ascii string containing the version of the software.
2284 An ascii string containing the name of the platform.
2288 A 32bit integer sent on the trigger.
2290 CONFIG_CDP_POWER_CONSUMPTION
2292 A 16bit integer containing the power consumption of the
2293 device in .1 of milliwatts.
2295 CONFIG_CDP_APPLIANCE_VLAN_TYPE
2297 A byte containing the id of the VLAN.
2299 - Status LED: CONFIG_STATUS_LED
2301 Several configurations allow to display the current
2302 status using a LED. For instance, the LED will blink
2303 fast while running U-Boot code, stop blinking as
2304 soon as a reply to a BOOTP request was received, and
2305 start blinking slow once the Linux kernel is running
2306 (supported by a status LED driver in the Linux
2307 kernel). Defining CONFIG_STATUS_LED enables this
2313 The status LED can be connected to a GPIO pin.
2314 In such cases, the gpio_led driver can be used as a
2315 status LED backend implementation. Define CONFIG_GPIO_LED
2316 to include the gpio_led driver in the U-Boot binary.
2318 CONFIG_GPIO_LED_INVERTED_TABLE
2319 Some GPIO connected LEDs may have inverted polarity in which
2320 case the GPIO high value corresponds to LED off state and
2321 GPIO low value corresponds to LED on state.
2322 In such cases CONFIG_GPIO_LED_INVERTED_TABLE may be defined
2323 with a list of GPIO LEDs that have inverted polarity.
2325 - CAN Support: CONFIG_CAN_DRIVER
2327 Defining CONFIG_CAN_DRIVER enables CAN driver support
2328 on those systems that support this (optional)
2329 feature, like the TQM8xxL modules.
2331 - I2C Support: CONFIG_SYS_I2C
2333 This enable the NEW i2c subsystem, and will allow you to use
2334 i2c commands at the u-boot command line (as long as you set
2335 CONFIG_CMD_I2C in CONFIG_COMMANDS) and communicate with i2c
2336 based realtime clock chips or other i2c devices. See
2337 common/cmd_i2c.c for a description of the command line
2340 ported i2c driver to the new framework:
2341 - drivers/i2c/soft_i2c.c:
2342 - activate first bus with CONFIG_SYS_I2C_SOFT define
2343 CONFIG_SYS_I2C_SOFT_SPEED and CONFIG_SYS_I2C_SOFT_SLAVE
2344 for defining speed and slave address
2345 - activate second bus with I2C_SOFT_DECLARATIONS2 define
2346 CONFIG_SYS_I2C_SOFT_SPEED_2 and CONFIG_SYS_I2C_SOFT_SLAVE_2
2347 for defining speed and slave address
2348 - activate third bus with I2C_SOFT_DECLARATIONS3 define
2349 CONFIG_SYS_I2C_SOFT_SPEED_3 and CONFIG_SYS_I2C_SOFT_SLAVE_3
2350 for defining speed and slave address
2351 - activate fourth bus with I2C_SOFT_DECLARATIONS4 define
2352 CONFIG_SYS_I2C_SOFT_SPEED_4 and CONFIG_SYS_I2C_SOFT_SLAVE_4
2353 for defining speed and slave address
2355 - drivers/i2c/fsl_i2c.c:
2356 - activate i2c driver with CONFIG_SYS_I2C_FSL
2357 define CONFIG_SYS_FSL_I2C_OFFSET for setting the register
2358 offset CONFIG_SYS_FSL_I2C_SPEED for the i2c speed and
2359 CONFIG_SYS_FSL_I2C_SLAVE for the slave addr of the first
2361 - If your board supports a second fsl i2c bus, define
2362 CONFIG_SYS_FSL_I2C2_OFFSET for the register offset
2363 CONFIG_SYS_FSL_I2C2_SPEED for the speed and
2364 CONFIG_SYS_FSL_I2C2_SLAVE for the slave address of the
2367 - drivers/i2c/tegra_i2c.c:
2368 - activate this driver with CONFIG_SYS_I2C_TEGRA
2369 - This driver adds 4 i2c buses with a fix speed from
2370 100000 and the slave addr 0!
2372 - drivers/i2c/ppc4xx_i2c.c
2373 - activate this driver with CONFIG_SYS_I2C_PPC4XX
2374 - CONFIG_SYS_I2C_PPC4XX_CH0 activate hardware channel 0
2375 - CONFIG_SYS_I2C_PPC4XX_CH1 activate hardware channel 1
2377 - drivers/i2c/i2c_mxc.c
2378 - activate this driver with CONFIG_SYS_I2C_MXC
2379 - define speed for bus 1 with CONFIG_SYS_MXC_I2C1_SPEED
2380 - define slave for bus 1 with CONFIG_SYS_MXC_I2C1_SLAVE
2381 - define speed for bus 2 with CONFIG_SYS_MXC_I2C2_SPEED
2382 - define slave for bus 2 with CONFIG_SYS_MXC_I2C2_SLAVE
2383 - define speed for bus 3 with CONFIG_SYS_MXC_I2C3_SPEED
2384 - define slave for bus 3 with CONFIG_SYS_MXC_I2C3_SLAVE
2385 If those defines are not set, default value is 100000
2386 for speed, and 0 for slave.
2387 - enable bus 3 with CONFIG_SYS_I2C_MXC_I2C3
2388 - enable bus 4 with CONFIG_SYS_I2C_MXC_I2C4
2390 - drivers/i2c/rcar_i2c.c:
2391 - activate this driver with CONFIG_SYS_I2C_RCAR
2392 - This driver adds 4 i2c buses
2394 - CONFIG_SYS_RCAR_I2C0_BASE for setting the register channel 0
2395 - CONFIG_SYS_RCAR_I2C0_SPEED for for the speed channel 0
2396 - CONFIG_SYS_RCAR_I2C1_BASE for setting the register channel 1
2397 - CONFIG_SYS_RCAR_I2C1_SPEED for for the speed channel 1
2398 - CONFIG_SYS_RCAR_I2C2_BASE for setting the register channel 2
2399 - CONFIG_SYS_RCAR_I2C2_SPEED for for the speed channel 2
2400 - CONFIG_SYS_RCAR_I2C3_BASE for setting the register channel 3
2401 - CONFIG_SYS_RCAR_I2C3_SPEED for for the speed channel 3
2402 - CONFIF_SYS_RCAR_I2C_NUM_CONTROLLERS for number of i2c buses
2404 - drivers/i2c/sh_i2c.c:
2405 - activate this driver with CONFIG_SYS_I2C_SH
2406 - This driver adds from 2 to 5 i2c buses
2408 - CONFIG_SYS_I2C_SH_BASE0 for setting the register channel 0
2409 - CONFIG_SYS_I2C_SH_SPEED0 for for the speed channel 0
2410 - CONFIG_SYS_I2C_SH_BASE1 for setting the register channel 1
2411 - CONFIG_SYS_I2C_SH_SPEED1 for for the speed channel 1
2412 - CONFIG_SYS_I2C_SH_BASE2 for setting the register channel 2
2413 - CONFIG_SYS_I2C_SH_SPEED2 for for the speed channel 2
2414 - CONFIG_SYS_I2C_SH_BASE3 for setting the register channel 3
2415 - CONFIG_SYS_I2C_SH_SPEED3 for for the speed channel 3
2416 - CONFIG_SYS_I2C_SH_BASE4 for setting the register channel 4
2417 - CONFIG_SYS_I2C_SH_SPEED4 for for the speed channel 4
2418 - CONFIG_SYS_I2C_SH_BASE5 for setting the register channel 5
2419 - CONFIG_SYS_I2C_SH_SPEED5 for for the speed channel 5
2420 - CONFIG_SYS_I2C_SH_NUM_CONTROLLERS for number of i2c buses
2422 - drivers/i2c/omap24xx_i2c.c
2423 - activate this driver with CONFIG_SYS_I2C_OMAP24XX
2424 - CONFIG_SYS_OMAP24_I2C_SPEED speed channel 0
2425 - CONFIG_SYS_OMAP24_I2C_SLAVE slave addr channel 0
2426 - CONFIG_SYS_OMAP24_I2C_SPEED1 speed channel 1
2427 - CONFIG_SYS_OMAP24_I2C_SLAVE1 slave addr channel 1
2428 - CONFIG_SYS_OMAP24_I2C_SPEED2 speed channel 2
2429 - CONFIG_SYS_OMAP24_I2C_SLAVE2 slave addr channel 2
2430 - CONFIG_SYS_OMAP24_I2C_SPEED3 speed channel 3
2431 - CONFIG_SYS_OMAP24_I2C_SLAVE3 slave addr channel 3
2432 - CONFIG_SYS_OMAP24_I2C_SPEED4 speed channel 4
2433 - CONFIG_SYS_OMAP24_I2C_SLAVE4 slave addr channel 4
2435 - drivers/i2c/zynq_i2c.c
2436 - activate this driver with CONFIG_SYS_I2C_ZYNQ
2437 - set CONFIG_SYS_I2C_ZYNQ_SPEED for speed setting
2438 - set CONFIG_SYS_I2C_ZYNQ_SLAVE for slave addr
2440 - drivers/i2c/s3c24x0_i2c.c:
2441 - activate this driver with CONFIG_SYS_I2C_S3C24X0
2442 - This driver adds i2c buses (11 for Exynos5250, Exynos5420
2443 9 i2c buses for Exynos4 and 1 for S3C24X0 SoCs from Samsung)
2444 with a fix speed from 100000 and the slave addr 0!
2446 - drivers/i2c/ihs_i2c.c
2447 - activate this driver with CONFIG_SYS_I2C_IHS
2448 - CONFIG_SYS_I2C_IHS_CH0 activate hardware channel 0
2449 - CONFIG_SYS_I2C_IHS_SPEED_0 speed channel 0
2450 - CONFIG_SYS_I2C_IHS_SLAVE_0 slave addr channel 0
2451 - CONFIG_SYS_I2C_IHS_CH1 activate hardware channel 1
2452 - CONFIG_SYS_I2C_IHS_SPEED_1 speed channel 1
2453 - CONFIG_SYS_I2C_IHS_SLAVE_1 slave addr channel 1
2454 - CONFIG_SYS_I2C_IHS_CH2 activate hardware channel 2
2455 - CONFIG_SYS_I2C_IHS_SPEED_2 speed channel 2
2456 - CONFIG_SYS_I2C_IHS_SLAVE_2 slave addr channel 2
2457 - CONFIG_SYS_I2C_IHS_CH3 activate hardware channel 3
2458 - CONFIG_SYS_I2C_IHS_SPEED_3 speed channel 3
2459 - CONFIG_SYS_I2C_IHS_SLAVE_3 slave addr channel 3
2463 CONFIG_SYS_NUM_I2C_BUSES
2464 Hold the number of i2c buses you want to use. If you
2465 don't use/have i2c muxes on your i2c bus, this
2466 is equal to CONFIG_SYS_NUM_I2C_ADAPTERS, and you can
2469 CONFIG_SYS_I2C_DIRECT_BUS
2470 define this, if you don't use i2c muxes on your hardware.
2471 if CONFIG_SYS_I2C_MAX_HOPS is not defined or == 0 you can
2474 CONFIG_SYS_I2C_MAX_HOPS
2475 define how many muxes are maximal consecutively connected
2476 on one i2c bus. If you not use i2c muxes, omit this
2479 CONFIG_SYS_I2C_BUSES
2480 hold a list of buses you want to use, only used if
2481 CONFIG_SYS_I2C_DIRECT_BUS is not defined, for example
2482 a board with CONFIG_SYS_I2C_MAX_HOPS = 1 and
2483 CONFIG_SYS_NUM_I2C_BUSES = 9:
2485 CONFIG_SYS_I2C_BUSES {{0, {I2C_NULL_HOP}}, \
2486 {0, {{I2C_MUX_PCA9547, 0x70, 1}}}, \
2487 {0, {{I2C_MUX_PCA9547, 0x70, 2}}}, \
2488 {0, {{I2C_MUX_PCA9547, 0x70, 3}}}, \
2489 {0, {{I2C_MUX_PCA9547, 0x70, 4}}}, \
2490 {0, {{I2C_MUX_PCA9547, 0x70, 5}}}, \
2491 {1, {I2C_NULL_HOP}}, \
2492 {1, {{I2C_MUX_PCA9544, 0x72, 1}}}, \
2493 {1, {{I2C_MUX_PCA9544, 0x72, 2}}}, \
2497 bus 0 on adapter 0 without a mux
2498 bus 1 on adapter 0 with a PCA9547 on address 0x70 port 1
2499 bus 2 on adapter 0 with a PCA9547 on address 0x70 port 2
2500 bus 3 on adapter 0 with a PCA9547 on address 0x70 port 3
2501 bus 4 on adapter 0 with a PCA9547 on address 0x70 port 4
2502 bus 5 on adapter 0 with a PCA9547 on address 0x70 port 5
2503 bus 6 on adapter 1 without a mux
2504 bus 7 on adapter 1 with a PCA9544 on address 0x72 port 1
2505 bus 8 on adapter 1 with a PCA9544 on address 0x72 port 2
2507 If you do not have i2c muxes on your board, omit this define.
2509 - Legacy I2C Support: CONFIG_HARD_I2C
2511 NOTE: It is intended to move drivers to CONFIG_SYS_I2C which
2512 provides the following compelling advantages:
2514 - more than one i2c adapter is usable
2515 - approved multibus support
2516 - better i2c mux support
2518 ** Please consider updating your I2C driver now. **
2520 These enable legacy I2C serial bus commands. Defining
2521 CONFIG_HARD_I2C will include the appropriate I2C driver
2522 for the selected CPU.
2524 This will allow you to use i2c commands at the u-boot
2525 command line (as long as you set CONFIG_CMD_I2C in
2526 CONFIG_COMMANDS) and communicate with i2c based realtime
2527 clock chips. See common/cmd_i2c.c for a description of the
2528 command line interface.
2530 CONFIG_HARD_I2C selects a hardware I2C controller.
2532 There are several other quantities that must also be
2533 defined when you define CONFIG_HARD_I2C.
2535 In both cases you will need to define CONFIG_SYS_I2C_SPEED
2536 to be the frequency (in Hz) at which you wish your i2c bus
2537 to run and CONFIG_SYS_I2C_SLAVE to be the address of this node (ie
2538 the CPU's i2c node address).
2540 Now, the u-boot i2c code for the mpc8xx
2541 (arch/powerpc/cpu/mpc8xx/i2c.c) sets the CPU up as a master node
2542 and so its address should therefore be cleared to 0 (See,
2543 eg, MPC823e User's Manual p.16-473). So, set
2544 CONFIG_SYS_I2C_SLAVE to 0.
2546 CONFIG_SYS_I2C_INIT_MPC5XXX
2548 When a board is reset during an i2c bus transfer
2549 chips might think that the current transfer is still
2550 in progress. Reset the slave devices by sending start
2551 commands until the slave device responds.
2553 That's all that's required for CONFIG_HARD_I2C.
2555 If you use the software i2c interface (CONFIG_SYS_I2C_SOFT)
2556 then the following macros need to be defined (examples are
2557 from include/configs/lwmon.h):
2561 (Optional). Any commands necessary to enable the I2C
2562 controller or configure ports.
2564 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
2568 (Only for MPC8260 CPU). The I/O port to use (the code
2569 assumes both bits are on the same port). Valid values
2570 are 0..3 for ports A..D.
2574 The code necessary to make the I2C data line active
2575 (driven). If the data line is open collector, this
2578 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
2582 The code necessary to make the I2C data line tri-stated
2583 (inactive). If the data line is open collector, this
2586 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
2590 Code that returns true if the I2C data line is high,
2593 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
2597 If <bit> is true, sets the I2C data line high. If it
2598 is false, it clears it (low).
2600 eg: #define I2C_SDA(bit) \
2601 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
2602 else immr->im_cpm.cp_pbdat &= ~PB_SDA
2606 If <bit> is true, sets the I2C clock line high. If it
2607 is false, it clears it (low).
2609 eg: #define I2C_SCL(bit) \
2610 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
2611 else immr->im_cpm.cp_pbdat &= ~PB_SCL
2615 This delay is invoked four times per clock cycle so this
2616 controls the rate of data transfer. The data rate thus
2617 is 1 / (I2C_DELAY * 4). Often defined to be something
2620 #define I2C_DELAY udelay(2)
2622 CONFIG_SOFT_I2C_GPIO_SCL / CONFIG_SOFT_I2C_GPIO_SDA
2624 If your arch supports the generic GPIO framework (asm/gpio.h),
2625 then you may alternatively define the two GPIOs that are to be
2626 used as SCL / SDA. Any of the previous I2C_xxx macros will
2627 have GPIO-based defaults assigned to them as appropriate.
2629 You should define these to the GPIO value as given directly to
2630 the generic GPIO functions.
2632 CONFIG_SYS_I2C_INIT_BOARD
2634 When a board is reset during an i2c bus transfer
2635 chips might think that the current transfer is still
2636 in progress. On some boards it is possible to access
2637 the i2c SCLK line directly, either by using the
2638 processor pin as a GPIO or by having a second pin
2639 connected to the bus. If this option is defined a
2640 custom i2c_init_board() routine in boards/xxx/board.c
2641 is run early in the boot sequence.
2643 CONFIG_SYS_I2C_BOARD_LATE_INIT
2645 An alternative to CONFIG_SYS_I2C_INIT_BOARD. If this option is
2646 defined a custom i2c_board_late_init() routine in
2647 boards/xxx/board.c is run AFTER the operations in i2c_init()
2648 is completed. This callpoint can be used to unreset i2c bus
2649 using CPU i2c controller register accesses for CPUs whose i2c
2650 controller provide such a method. It is called at the end of
2651 i2c_init() to allow i2c_init operations to setup the i2c bus
2652 controller on the CPU (e.g. setting bus speed & slave address).
2654 CONFIG_I2CFAST (PPC405GP|PPC405EP only)
2656 This option enables configuration of bi_iic_fast[] flags
2657 in u-boot bd_info structure based on u-boot environment
2658 variable "i2cfast". (see also i2cfast)
2660 CONFIG_I2C_MULTI_BUS
2662 This option allows the use of multiple I2C buses, each of which
2663 must have a controller. At any point in time, only one bus is
2664 active. To switch to a different bus, use the 'i2c dev' command.
2665 Note that bus numbering is zero-based.
2667 CONFIG_SYS_I2C_NOPROBES
2669 This option specifies a list of I2C devices that will be skipped
2670 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS
2671 is set, specify a list of bus-device pairs. Otherwise, specify
2672 a 1D array of device addresses
2675 #undef CONFIG_I2C_MULTI_BUS
2676 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68}
2678 will skip addresses 0x50 and 0x68 on a board with one I2C bus
2680 #define CONFIG_I2C_MULTI_BUS
2681 #define CONFIG_SYS_I2C_MULTI_NOPROBES {{0,0x50},{0,0x68},{1,0x54}}
2683 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1
2685 CONFIG_SYS_SPD_BUS_NUM
2687 If defined, then this indicates the I2C bus number for DDR SPD.
2688 If not defined, then U-Boot assumes that SPD is on I2C bus 0.
2690 CONFIG_SYS_RTC_BUS_NUM
2692 If defined, then this indicates the I2C bus number for the RTC.
2693 If not defined, then U-Boot assumes that RTC is on I2C bus 0.
2695 CONFIG_SYS_DTT_BUS_NUM
2697 If defined, then this indicates the I2C bus number for the DTT.
2698 If not defined, then U-Boot assumes that DTT is on I2C bus 0.
2700 CONFIG_SYS_I2C_DTT_ADDR:
2702 If defined, specifies the I2C address of the DTT device.
2703 If not defined, then U-Boot uses predefined value for
2704 specified DTT device.
2706 CONFIG_SOFT_I2C_READ_REPEATED_START
2708 defining this will force the i2c_read() function in
2709 the soft_i2c driver to perform an I2C repeated start
2710 between writing the address pointer and reading the
2711 data. If this define is omitted the default behaviour
2712 of doing a stop-start sequence will be used. Most I2C
2713 devices can use either method, but some require one or
2716 - SPI Support: CONFIG_SPI
2718 Enables SPI driver (so far only tested with
2719 SPI EEPROM, also an instance works with Crystal A/D and
2720 D/As on the SACSng board)
2724 Enables the driver for SPI controller on SuperH. Currently
2725 only SH7757 is supported.
2729 Enables extended (16-bit) SPI EEPROM addressing.
2730 (symmetrical to CONFIG_I2C_X)
2734 Enables a software (bit-bang) SPI driver rather than
2735 using hardware support. This is a general purpose
2736 driver that only requires three general I/O port pins
2737 (two outputs, one input) to function. If this is
2738 defined, the board configuration must define several
2739 SPI configuration items (port pins to use, etc). For
2740 an example, see include/configs/sacsng.h.
2744 Enables a hardware SPI driver for general-purpose reads
2745 and writes. As with CONFIG_SOFT_SPI, the board configuration
2746 must define a list of chip-select function pointers.
2747 Currently supported on some MPC8xxx processors. For an
2748 example, see include/configs/mpc8349emds.h.
2752 Enables the driver for the SPI controllers on i.MX and MXC
2753 SoCs. Currently i.MX31/35/51 are supported.
2755 CONFIG_SYS_SPI_MXC_WAIT
2756 Timeout for waiting until spi transfer completed.
2757 default: (CONFIG_SYS_HZ/100) /* 10 ms */
2759 - FPGA Support: CONFIG_FPGA
2761 Enables FPGA subsystem.
2763 CONFIG_FPGA_<vendor>
2765 Enables support for specific chip vendors.
2768 CONFIG_FPGA_<family>
2770 Enables support for FPGA family.
2771 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX)
2775 Specify the number of FPGA devices to support.
2777 CONFIG_CMD_FPGA_LOADMK
2779 Enable support for fpga loadmk command
2781 CONFIG_CMD_FPGA_LOADP
2783 Enable support for fpga loadp command - load partial bitstream
2785 CONFIG_CMD_FPGA_LOADBP
2787 Enable support for fpga loadbp command - load partial bitstream
2790 CONFIG_SYS_FPGA_PROG_FEEDBACK
2792 Enable printing of hash marks during FPGA configuration.
2794 CONFIG_SYS_FPGA_CHECK_BUSY
2796 Enable checks on FPGA configuration interface busy
2797 status by the configuration function. This option
2798 will require a board or device specific function to
2803 If defined, a function that provides delays in the FPGA
2804 configuration driver.
2806 CONFIG_SYS_FPGA_CHECK_CTRLC
2807 Allow Control-C to interrupt FPGA configuration
2809 CONFIG_SYS_FPGA_CHECK_ERROR
2811 Check for configuration errors during FPGA bitfile
2812 loading. For example, abort during Virtex II
2813 configuration if the INIT_B line goes low (which
2814 indicated a CRC error).
2816 CONFIG_SYS_FPGA_WAIT_INIT
2818 Maximum time to wait for the INIT_B line to de-assert
2819 after PROB_B has been de-asserted during a Virtex II
2820 FPGA configuration sequence. The default time is 500
2823 CONFIG_SYS_FPGA_WAIT_BUSY
2825 Maximum time to wait for BUSY to de-assert during
2826 Virtex II FPGA configuration. The default is 5 ms.
2828 CONFIG_SYS_FPGA_WAIT_CONFIG
2830 Time to wait after FPGA configuration. The default is
2833 - Configuration Management:
2836 Some SoCs need special image types (e.g. U-Boot binary
2837 with a special header) as build targets. By defining
2838 CONFIG_BUILD_TARGET in the SoC / board header, this
2839 special image will be automatically built upon calling
2844 If defined, this string will be added to the U-Boot
2845 version information (U_BOOT_VERSION)
2847 - Vendor Parameter Protection:
2849 U-Boot considers the values of the environment
2850 variables "serial#" (Board Serial Number) and
2851 "ethaddr" (Ethernet Address) to be parameters that
2852 are set once by the board vendor / manufacturer, and
2853 protects these variables from casual modification by
2854 the user. Once set, these variables are read-only,
2855 and write or delete attempts are rejected. You can
2856 change this behaviour:
2858 If CONFIG_ENV_OVERWRITE is #defined in your config
2859 file, the write protection for vendor parameters is
2860 completely disabled. Anybody can change or delete
2863 Alternatively, if you define _both_ an ethaddr in the
2864 default env _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
2865 Ethernet address is installed in the environment,
2866 which can be changed exactly ONCE by the user. [The
2867 serial# is unaffected by this, i. e. it remains
2870 The same can be accomplished in a more flexible way
2871 for any variable by configuring the type of access
2872 to allow for those variables in the ".flags" variable
2873 or define CONFIG_ENV_FLAGS_LIST_STATIC.
2878 Define this variable to enable the reservation of
2879 "protected RAM", i. e. RAM which is not overwritten
2880 by U-Boot. Define CONFIG_PRAM to hold the number of
2881 kB you want to reserve for pRAM. You can overwrite
2882 this default value by defining an environment
2883 variable "pram" to the number of kB you want to
2884 reserve. Note that the board info structure will
2885 still show the full amount of RAM. If pRAM is
2886 reserved, a new environment variable "mem" will
2887 automatically be defined to hold the amount of
2888 remaining RAM in a form that can be passed as boot
2889 argument to Linux, for instance like that:
2891 setenv bootargs ... mem=\${mem}
2894 This way you can tell Linux not to use this memory,
2895 either, which results in a memory region that will
2896 not be affected by reboots.
2898 *WARNING* If your board configuration uses automatic
2899 detection of the RAM size, you must make sure that
2900 this memory test is non-destructive. So far, the
2901 following board configurations are known to be
2904 IVMS8, IVML24, SPD8xx, TQM8xxL,
2905 HERMES, IP860, RPXlite, LWMON,
2908 - Access to physical memory region (> 4GB)
2909 Some basic support is provided for operations on memory not
2910 normally accessible to U-Boot - e.g. some architectures
2911 support access to more than 4GB of memory on 32-bit
2912 machines using physical address extension or similar.
2913 Define CONFIG_PHYSMEM to access this basic support, which
2914 currently only supports clearing the memory.
2919 Define this variable to stop the system in case of a
2920 fatal error, so that you have to reset it manually.
2921 This is probably NOT a good idea for an embedded
2922 system where you want the system to reboot
2923 automatically as fast as possible, but it may be
2924 useful during development since you can try to debug
2925 the conditions that lead to the situation.
2927 CONFIG_NET_RETRY_COUNT
2929 This variable defines the number of retries for
2930 network operations like ARP, RARP, TFTP, or BOOTP
2931 before giving up the operation. If not defined, a
2932 default value of 5 is used.
2936 Timeout waiting for an ARP reply in milliseconds.
2940 Timeout in milliseconds used in NFS protocol.
2941 If you encounter "ERROR: Cannot umount" in nfs command,
2942 try longer timeout such as
2943 #define CONFIG_NFS_TIMEOUT 10000UL
2945 - Command Interpreter:
2946 CONFIG_AUTO_COMPLETE
2948 Enable auto completion of commands using TAB.
2950 CONFIG_SYS_PROMPT_HUSH_PS2
2952 This defines the secondary prompt string, which is
2953 printed when the command interpreter needs more input
2954 to complete a command. Usually "> ".
2958 In the current implementation, the local variables
2959 space and global environment variables space are
2960 separated. Local variables are those you define by
2961 simply typing `name=value'. To access a local
2962 variable later on, you have write `$name' or
2963 `${name}'; to execute the contents of a variable
2964 directly type `$name' at the command prompt.
2966 Global environment variables are those you use
2967 setenv/printenv to work with. To run a command stored
2968 in such a variable, you need to use the run command,
2969 and you must not use the '$' sign to access them.
2971 To store commands and special characters in a
2972 variable, please use double quotation marks
2973 surrounding the whole text of the variable, instead
2974 of the backslashes before semicolons and special
2977 - Command Line Editing and History:
2978 CONFIG_CMDLINE_EDITING
2980 Enable editing and History functions for interactive
2981 command line input operations
2983 - Default Environment:
2984 CONFIG_EXTRA_ENV_SETTINGS
2986 Define this to contain any number of null terminated
2987 strings (variable = value pairs) that will be part of
2988 the default environment compiled into the boot image.
2990 For example, place something like this in your
2991 board's config file:
2993 #define CONFIG_EXTRA_ENV_SETTINGS \
2997 Warning: This method is based on knowledge about the
2998 internal format how the environment is stored by the
2999 U-Boot code. This is NOT an official, exported
3000 interface! Although it is unlikely that this format
3001 will change soon, there is no guarantee either.
3002 You better know what you are doing here.
3004 Note: overly (ab)use of the default environment is
3005 discouraged. Make sure to check other ways to preset
3006 the environment like the "source" command or the
3009 CONFIG_ENV_VARS_UBOOT_CONFIG
3011 Define this in order to add variables describing the
3012 U-Boot build configuration to the default environment.
3013 These will be named arch, cpu, board, vendor, and soc.
3015 Enabling this option will cause the following to be defined:
3023 CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG
3025 Define this in order to add variables describing certain
3026 run-time determined information about the hardware to the
3027 environment. These will be named board_name, board_rev.
3029 CONFIG_DELAY_ENVIRONMENT
3031 Normally the environment is loaded when the board is
3032 initialised so that it is available to U-Boot. This inhibits
3033 that so that the environment is not available until
3034 explicitly loaded later by U-Boot code. With CONFIG_OF_CONTROL
3035 this is instead controlled by the value of
3036 /config/load-environment.
3038 - Parallel Flash support:
3041 Traditionally U-boot was run on systems with parallel NOR
3042 flash. This option is used to disable support for parallel NOR
3043 flash. This option should be defined if the board does not have
3046 If this option is not defined one of the generic flash drivers
3047 (e.g. CONFIG_FLASH_CFI_DRIVER or CONFIG_ST_SMI) must be
3048 selected or the board must provide an implementation of the
3049 flash API (see include/flash.h).
3051 - DataFlash Support:
3052 CONFIG_HAS_DATAFLASH
3054 Defining this option enables DataFlash features and
3055 allows to read/write in Dataflash via the standard
3058 - Serial Flash support
3061 Defining this option enables SPI flash commands
3062 'sf probe/read/write/erase/update'.
3064 Usage requires an initial 'probe' to define the serial
3065 flash parameters, followed by read/write/erase/update
3068 The following defaults may be provided by the platform
3069 to handle the common case when only a single serial
3070 flash is present on the system.
3072 CONFIG_SF_DEFAULT_BUS Bus identifier
3073 CONFIG_SF_DEFAULT_CS Chip-select
3074 CONFIG_SF_DEFAULT_MODE (see include/spi.h)
3075 CONFIG_SF_DEFAULT_SPEED in Hz
3079 Define this option to include a destructive SPI flash
3082 CONFIG_SPI_FLASH_BAR Ban/Extended Addr Reg
3084 Define this option to use the Bank addr/Extended addr
3085 support on SPI flashes which has size > 16Mbytes.
3087 CONFIG_SF_DUAL_FLASH Dual flash memories
3089 Define this option to use dual flash support where two flash
3090 memories can be connected with a given cs line.
3091 Currently Xilinx Zynq qspi supports these type of connections.
3093 CONFIG_SPI_FLASH_MTD spi-flash MTD layer
3095 Define this option to use mtd support for spi flash layer, this
3096 adapter is for translating mtd_read/mtd_write commands into
3097 spi_flash_read/spi_flash_write commands. It is not intended to
3098 use it within sf_cmd or the SPI flash subsystem. Such an adapter
3099 is needed for subsystems like UBI which can only operate on top
3102 - SystemACE Support:
3105 Adding this option adds support for Xilinx SystemACE
3106 chips attached via some sort of local bus. The address
3107 of the chip must also be defined in the
3108 CONFIG_SYS_SYSTEMACE_BASE macro. For example:
3110 #define CONFIG_SYSTEMACE
3111 #define CONFIG_SYS_SYSTEMACE_BASE 0xf0000000
3113 When SystemACE support is added, the "ace" device type
3114 becomes available to the fat commands, i.e. fatls.
3116 - TFTP Fixed UDP Port:
3119 If this is defined, the environment variable tftpsrcp
3120 is used to supply the TFTP UDP source port value.
3121 If tftpsrcp isn't defined, the normal pseudo-random port
3122 number generator is used.
3124 Also, the environment variable tftpdstp is used to supply
3125 the TFTP UDP destination port value. If tftpdstp isn't
3126 defined, the normal port 69 is used.
3128 The purpose for tftpsrcp is to allow a TFTP server to
3129 blindly start the TFTP transfer using the pre-configured
3130 target IP address and UDP port. This has the effect of
3131 "punching through" the (Windows XP) firewall, allowing
3132 the remainder of the TFTP transfer to proceed normally.
3133 A better solution is to properly configure the firewall,
3134 but sometimes that is not allowed.
3139 This enables a generic 'hash' command which can produce
3140 hashes / digests from a few algorithms (e.g. SHA1, SHA256).
3144 Enable the hash verify command (hash -v). This adds to code
3147 CONFIG_SHA1 - This option enables support of hashing using SHA1
3148 algorithm. The hash is calculated in software.
3149 CONFIG_SHA256 - This option enables support of hashing using
3150 SHA256 algorithm. The hash is calculated in software.
3151 CONFIG_SHA_HW_ACCEL - This option enables hardware acceleration
3152 for SHA1/SHA256 hashing.
3153 This affects the 'hash' command and also the
3154 hash_lookup_algo() function.
3155 CONFIG_SHA_PROG_HW_ACCEL - This option enables
3156 hardware-acceleration for SHA1/SHA256 progressive hashing.
3157 Data can be streamed in a block at a time and the hashing
3158 is performed in hardware.
3160 Note: There is also a sha1sum command, which should perhaps
3161 be deprecated in favour of 'hash sha1'.
3163 - Freescale i.MX specific commands:
3164 CONFIG_CMD_HDMIDETECT
3165 This enables 'hdmidet' command which returns true if an
3166 HDMI monitor is detected. This command is i.MX 6 specific.
3169 This enables the 'bmode' (bootmode) command for forcing
3170 a boot from specific media.
3172 This is useful for forcing the ROM's usb downloader to
3173 activate upon a watchdog reset which is nice when iterating
3174 on U-Boot. Using the reset button or running bmode normal
3175 will set it back to normal. This command currently
3176 supports i.MX53 and i.MX6.
3181 This enables the RSA algorithm used for FIT image verification
3182 in U-Boot. See doc/uImage.FIT/signature.txt for more information.
3184 The Modular Exponentiation algorithm in RSA is implemented using
3185 driver model. So CONFIG_DM needs to be enabled by default for this
3186 library to function.
3188 The signing part is build into mkimage regardless of this
3189 option. The software based modular exponentiation is built into
3190 mkimage irrespective of this option.
3192 - bootcount support:
3193 CONFIG_BOOTCOUNT_LIMIT
3195 This enables the bootcounter support, see:
3196 http://www.denx.de/wiki/DULG/UBootBootCountLimit
3199 enable special bootcounter support on at91sam9xe based boards.
3201 enable special bootcounter support on blackfin based boards.
3203 enable special bootcounter support on da850 based boards.
3204 CONFIG_BOOTCOUNT_RAM
3205 enable support for the bootcounter in RAM
3206 CONFIG_BOOTCOUNT_I2C
3207 enable support for the bootcounter on an i2c (like RTC) device.
3208 CONFIG_SYS_I2C_RTC_ADDR = i2c chip address
3209 CONFIG_SYS_BOOTCOUNT_ADDR = i2c addr which is used for
3211 CONFIG_BOOTCOUNT_ALEN = address len
3213 - Show boot progress:
3214 CONFIG_SHOW_BOOT_PROGRESS
3216 Defining this option allows to add some board-
3217 specific code (calling a user-provided function
3218 "show_boot_progress(int)") that enables you to show
3219 the system's boot progress on some display (for
3220 example, some LED's) on your board. At the moment,
3221 the following checkpoints are implemented:
3224 Legacy uImage format:
3227 1 common/cmd_bootm.c before attempting to boot an image
3228 -1 common/cmd_bootm.c Image header has bad magic number
3229 2 common/cmd_bootm.c Image header has correct magic number
3230 -2 common/cmd_bootm.c Image header has bad checksum
3231 3 common/cmd_bootm.c Image header has correct checksum
3232 -3 common/cmd_bootm.c Image data has bad checksum
3233 4 common/cmd_bootm.c Image data has correct checksum
3234 -4 common/cmd_bootm.c Image is for unsupported architecture
3235 5 common/cmd_bootm.c Architecture check OK
3236 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi)
3237 6 common/cmd_bootm.c Image Type check OK
3238 -6 common/cmd_bootm.c gunzip uncompression error
3239 -7 common/cmd_bootm.c Unimplemented compression type
3240 7 common/cmd_bootm.c Uncompression OK
3241 8 common/cmd_bootm.c No uncompress/copy overwrite error
3242 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX)
3244 9 common/image.c Start initial ramdisk verification
3245 -10 common/image.c Ramdisk header has bad magic number
3246 -11 common/image.c Ramdisk header has bad checksum
3247 10 common/image.c Ramdisk header is OK
3248 -12 common/image.c Ramdisk data has bad checksum
3249 11 common/image.c Ramdisk data has correct checksum
3250 12 common/image.c Ramdisk verification complete, start loading
3251 -13 common/image.c Wrong Image Type (not PPC Linux ramdisk)
3252 13 common/image.c Start multifile image verification
3253 14 common/image.c No initial ramdisk, no multifile, continue.
3255 15 arch/<arch>/lib/bootm.c All preparation done, transferring control to OS
3257 -30 arch/powerpc/lib/board.c Fatal error, hang the system
3258 -31 post/post.c POST test failed, detected by post_output_backlog()
3259 -32 post/post.c POST test failed, detected by post_run_single()
3261 34 common/cmd_doc.c before loading a Image from a DOC device
3262 -35 common/cmd_doc.c Bad usage of "doc" command
3263 35 common/cmd_doc.c correct usage of "doc" command
3264 -36 common/cmd_doc.c No boot device
3265 36 common/cmd_doc.c correct boot device
3266 -37 common/cmd_doc.c Unknown Chip ID on boot device
3267 37 common/cmd_doc.c correct chip ID found, device available
3268 -38 common/cmd_doc.c Read Error on boot device
3269 38 common/cmd_doc.c reading Image header from DOC device OK
3270 -39 common/cmd_doc.c Image header has bad magic number
3271 39 common/cmd_doc.c Image header has correct magic number
3272 -40 common/cmd_doc.c Error reading Image from DOC device
3273 40 common/cmd_doc.c Image header has correct magic number
3274 41 common/cmd_ide.c before loading a Image from a IDE device
3275 -42 common/cmd_ide.c Bad usage of "ide" command
3276 42 common/cmd_ide.c correct usage of "ide" command
3277 -43 common/cmd_ide.c No boot device
3278 43 common/cmd_ide.c boot device found
3279 -44 common/cmd_ide.c Device not available
3280 44 common/cmd_ide.c Device available
3281 -45 common/cmd_ide.c wrong partition selected
3282 45 common/cmd_ide.c partition selected
3283 -46 common/cmd_ide.c Unknown partition table
3284 46 common/cmd_ide.c valid partition table found
3285 -47 common/cmd_ide.c Invalid partition type
3286 47 common/cmd_ide.c correct partition type
3287 -48 common/cmd_ide.c Error reading Image Header on boot device
3288 48 common/cmd_ide.c reading Image Header from IDE device OK
3289 -49 common/cmd_ide.c Image header has bad magic number
3290 49 common/cmd_ide.c Image header has correct magic number
3291 -50 common/cmd_ide.c Image header has bad checksum
3292 50 common/cmd_ide.c Image header has correct checksum
3293 -51 common/cmd_ide.c Error reading Image from IDE device
3294 51 common/cmd_ide.c reading Image from IDE device OK
3295 52 common/cmd_nand.c before loading a Image from a NAND device
3296 -53 common/cmd_nand.c Bad usage of "nand" command
3297 53 common/cmd_nand.c correct usage of "nand" command
3298 -54 common/cmd_nand.c No boot device
3299 54 common/cmd_nand.c boot device found
3300 -55 common/cmd_nand.c Unknown Chip ID on boot device
3301 55 common/cmd_nand.c correct chip ID found, device available
3302 -56 common/cmd_nand.c Error reading Image Header on boot device
3303 56 common/cmd_nand.c reading Image Header from NAND device OK
3304 -57 common/cmd_nand.c Image header has bad magic number
3305 57 common/cmd_nand.c Image header has correct magic number
3306 -58 common/cmd_nand.c Error reading Image from NAND device
3307 58 common/cmd_nand.c reading Image from NAND device OK
3309 -60 common/env_common.c Environment has a bad CRC, using default
3311 64 net/eth.c starting with Ethernet configuration.
3312 -64 net/eth.c no Ethernet found.
3313 65 net/eth.c Ethernet found.
3315 -80 common/cmd_net.c usage wrong
3316 80 common/cmd_net.c before calling net_loop()
3317 -81 common/cmd_net.c some error in net_loop() occurred
3318 81 common/cmd_net.c net_loop() back without error
3319 -82 common/cmd_net.c size == 0 (File with size 0 loaded)
3320 82 common/cmd_net.c trying automatic boot
3321 83 common/cmd_net.c running "source" command
3322 -83 common/cmd_net.c some error in automatic boot or "source" command
3323 84 common/cmd_net.c end without errors
3328 100 common/cmd_bootm.c Kernel FIT Image has correct format
3329 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format
3330 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration
3331 -101 common/cmd_bootm.c Can't get configuration for kernel subimage
3332 102 common/cmd_bootm.c Kernel unit name specified
3333 -103 common/cmd_bootm.c Can't get kernel subimage node offset
3334 103 common/cmd_bootm.c Found configuration node
3335 104 common/cmd_bootm.c Got kernel subimage node offset
3336 -104 common/cmd_bootm.c Kernel subimage hash verification failed
3337 105 common/cmd_bootm.c Kernel subimage hash verification OK
3338 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture
3339 106 common/cmd_bootm.c Architecture check OK
3340 -106 common/cmd_bootm.c Kernel subimage has wrong type
3341 107 common/cmd_bootm.c Kernel subimage type OK
3342 -107 common/cmd_bootm.c Can't get kernel subimage data/size
3343 108 common/cmd_bootm.c Got kernel subimage data/size
3344 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT)
3345 -109 common/cmd_bootm.c Can't get kernel subimage type
3346 -110 common/cmd_bootm.c Can't get kernel subimage comp
3347 -111 common/cmd_bootm.c Can't get kernel subimage os
3348 -112 common/cmd_bootm.c Can't get kernel subimage load address
3349 -113 common/cmd_bootm.c Image uncompress/copy overwrite error
3351 120 common/image.c Start initial ramdisk verification
3352 -120 common/image.c Ramdisk FIT image has incorrect format
3353 121 common/image.c Ramdisk FIT image has correct format
3354 122 common/image.c No ramdisk subimage unit name, using configuration
3355 -122 common/image.c Can't get configuration for ramdisk subimage
3356 123 common/image.c Ramdisk unit name specified
3357 -124 common/image.c Can't get ramdisk subimage node offset
3358 125 common/image.c Got ramdisk subimage node offset
3359 -125 common/image.c Ramdisk subimage hash verification failed
3360 126 common/image.c Ramdisk subimage hash verification OK
3361 -126 common/image.c Ramdisk subimage for unsupported architecture
3362 127 common/image.c Architecture check OK
3363 -127 common/image.c Can't get ramdisk subimage data/size
3364 128 common/image.c Got ramdisk subimage data/size
3365 129 common/image.c Can't get ramdisk load address
3366 -129 common/image.c Got ramdisk load address
3368 -130 common/cmd_doc.c Incorrect FIT image format
3369 131 common/cmd_doc.c FIT image format OK
3371 -140 common/cmd_ide.c Incorrect FIT image format
3372 141 common/cmd_ide.c FIT image format OK
3374 -150 common/cmd_nand.c Incorrect FIT image format
3375 151 common/cmd_nand.c FIT image format OK
3377 - legacy image format:
3378 CONFIG_IMAGE_FORMAT_LEGACY
3379 enables the legacy image format support in U-Boot.
3382 enabled if CONFIG_FIT_SIGNATURE is not defined.
3384 CONFIG_DISABLE_IMAGE_LEGACY
3385 disable the legacy image format
3387 This define is introduced, as the legacy image format is
3388 enabled per default for backward compatibility.
3390 - FIT image support:
3392 Enable support for the FIT uImage format.
3394 CONFIG_FIT_BEST_MATCH
3395 When no configuration is explicitly selected, default to the
3396 one whose fdt's compatibility field best matches that of
3397 U-Boot itself. A match is considered "best" if it matches the
3398 most specific compatibility entry of U-Boot's fdt's root node.
3399 The order of entries in the configuration's fdt is ignored.
3401 CONFIG_FIT_SIGNATURE
3402 This option enables signature verification of FIT uImages,
3403 using a hash signed and verified using RSA. If
3404 CONFIG_SHA_PROG_HW_ACCEL is defined, i.e support for progressive
3405 hashing is available using hardware, RSA library will use it.
3406 See doc/uImage.FIT/signature.txt for more details.
3408 WARNING: When relying on signed FIT images with required
3409 signature check the legacy image format is default
3410 disabled. If a board need legacy image format support
3411 enable this through CONFIG_IMAGE_FORMAT_LEGACY
3413 CONFIG_FIT_DISABLE_SHA256
3414 Supporting SHA256 hashes has quite an impact on binary size.
3415 For constrained systems sha256 hash support can be disabled
3418 - Standalone program support:
3419 CONFIG_STANDALONE_LOAD_ADDR
3421 This option defines a board specific value for the
3422 address where standalone program gets loaded, thus
3423 overwriting the architecture dependent default
3426 - Frame Buffer Address:
3429 Define CONFIG_FB_ADDR if you want to use specific
3430 address for frame buffer. This is typically the case
3431 when using a graphics controller has separate video
3432 memory. U-Boot will then place the frame buffer at
3433 the given address instead of dynamically reserving it
3434 in system RAM by calling lcd_setmem(), which grabs
3435 the memory for the frame buffer depending on the
3436 configured panel size.
3438 Please see board_init_f function.
3440 - Automatic software updates via TFTP server
3442 CONFIG_UPDATE_TFTP_CNT_MAX
3443 CONFIG_UPDATE_TFTP_MSEC_MAX
3445 These options enable and control the auto-update feature;
3446 for a more detailed description refer to doc/README.update.
3448 - MTD Support (mtdparts command, UBI support)
3451 Adds the MTD device infrastructure from the Linux kernel.
3452 Needed for mtdparts command support.
3454 CONFIG_MTD_PARTITIONS
3456 Adds the MTD partitioning infrastructure from the Linux
3457 kernel. Needed for UBI support.
3462 Adds commands for interacting with MTD partitions formatted
3463 with the UBI flash translation layer
3465 Requires also defining CONFIG_RBTREE
3467 CONFIG_UBI_SILENCE_MSG
3469 Make the verbose messages from UBI stop printing. This leaves
3470 warnings and errors enabled.
3473 CONFIG_MTD_UBI_WL_THRESHOLD
3474 This parameter defines the maximum difference between the highest
3475 erase counter value and the lowest erase counter value of eraseblocks
3476 of UBI devices. When this threshold is exceeded, UBI starts performing
3477 wear leveling by means of moving data from eraseblock with low erase
3478 counter to eraseblocks with high erase counter.
3480 The default value should be OK for SLC NAND flashes, NOR flashes and
3481 other flashes which have eraseblock life-cycle 100000 or more.
3482 However, in case of MLC NAND flashes which typically have eraseblock
3483 life-cycle less than 10000, the threshold should be lessened (e.g.,
3484 to 128 or 256, although it does not have to be power of 2).
3488 CONFIG_MTD_UBI_BEB_LIMIT
3489 This option specifies the maximum bad physical eraseblocks UBI
3490 expects on the MTD device (per 1024 eraseblocks). If the
3491 underlying flash does not admit of bad eraseblocks (e.g. NOR
3492 flash), this value is ignored.
3494 NAND datasheets often specify the minimum and maximum NVM
3495 (Number of Valid Blocks) for the flashes' endurance lifetime.
3496 The maximum expected bad eraseblocks per 1024 eraseblocks
3497 then can be calculated as "1024 * (1 - MinNVB / MaxNVB)",
3498 which gives 20 for most NANDs (MaxNVB is basically the total
3499 count of eraseblocks on the chip).
3501 To put it differently, if this value is 20, UBI will try to
3502 reserve about 1.9% of physical eraseblocks for bad blocks
3503 handling. And that will be 1.9% of eraseblocks on the entire
3504 NAND chip, not just the MTD partition UBI attaches. This means
3505 that if you have, say, a NAND flash chip admits maximum 40 bad
3506 eraseblocks, and it is split on two MTD partitions of the same
3507 size, UBI will reserve 40 eraseblocks when attaching a
3512 CONFIG_MTD_UBI_FASTMAP
3513 Fastmap is a mechanism which allows attaching an UBI device
3514 in nearly constant time. Instead of scanning the whole MTD device it
3515 only has to locate a checkpoint (called fastmap) on the device.
3516 The on-flash fastmap contains all information needed to attach
3517 the device. Using fastmap makes only sense on large devices where
3518 attaching by scanning takes long. UBI will not automatically install
3519 a fastmap on old images, but you can set the UBI parameter
3520 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT to 1 if you want so. Please note
3521 that fastmap-enabled images are still usable with UBI implementations
3522 without fastmap support. On typical flash devices the whole fastmap
3523 fits into one PEB. UBI will reserve PEBs to hold two fastmaps.
3525 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT
3526 Set this parameter to enable fastmap automatically on images
3533 Adds commands for interacting with UBI volumes formatted as
3534 UBIFS. UBIFS is read-only in u-boot.
3536 Requires UBI support as well as CONFIG_LZO
3538 CONFIG_UBIFS_SILENCE_MSG
3540 Make the verbose messages from UBIFS stop printing. This leaves
3541 warnings and errors enabled.
3545 Enable building of SPL globally.
3548 LDSCRIPT for linking the SPL binary.
3550 CONFIG_SPL_MAX_FOOTPRINT
3551 Maximum size in memory allocated to the SPL, BSS included.
3552 When defined, the linker checks that the actual memory
3553 used by SPL from _start to __bss_end does not exceed it.
3554 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
3555 must not be both defined at the same time.
3558 Maximum size of the SPL image (text, data, rodata, and
3559 linker lists sections), BSS excluded.
3560 When defined, the linker checks that the actual size does
3563 CONFIG_SPL_TEXT_BASE
3564 TEXT_BASE for linking the SPL binary.
3566 CONFIG_SPL_RELOC_TEXT_BASE
3567 Address to relocate to. If unspecified, this is equal to
3568 CONFIG_SPL_TEXT_BASE (i.e. no relocation is done).
3570 CONFIG_SPL_BSS_START_ADDR
3571 Link address for the BSS within the SPL binary.
3573 CONFIG_SPL_BSS_MAX_SIZE
3574 Maximum size in memory allocated to the SPL BSS.
3575 When defined, the linker checks that the actual memory used
3576 by SPL from __bss_start to __bss_end does not exceed it.
3577 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
3578 must not be both defined at the same time.
3581 Adress of the start of the stack SPL will use
3583 CONFIG_SPL_PANIC_ON_RAW_IMAGE
3584 When defined, SPL will panic() if the image it has
3585 loaded does not have a signature.
3586 Defining this is useful when code which loads images
3587 in SPL cannot guarantee that absolutely all read errors
3589 An example is the LPC32XX MLC NAND driver, which will
3590 consider that a completely unreadable NAND block is bad,
3591 and thus should be skipped silently.
3593 CONFIG_SPL_RELOC_STACK
3594 Adress of the start of the stack SPL will use after
3595 relocation. If unspecified, this is equal to
3598 CONFIG_SYS_SPL_MALLOC_START
3599 Starting address of the malloc pool used in SPL.
3601 CONFIG_SYS_SPL_MALLOC_SIZE
3602 The size of the malloc pool used in SPL.
3604 CONFIG_SPL_FRAMEWORK
3605 Enable the SPL framework under common/. This framework
3606 supports MMC, NAND and YMODEM loading of U-Boot and NAND
3607 NAND loading of the Linux Kernel.
3610 Enable booting directly to an OS from SPL.
3611 See also: doc/README.falcon
3613 CONFIG_SPL_DISPLAY_PRINT
3614 For ARM, enable an optional function to print more information
3615 about the running system.
3617 CONFIG_SPL_INIT_MINIMAL
3618 Arch init code should be built for a very small image
3620 CONFIG_SPL_LIBCOMMON_SUPPORT
3621 Support for common/libcommon.o in SPL binary
3623 CONFIG_SPL_LIBDISK_SUPPORT
3624 Support for disk/libdisk.o in SPL binary
3626 CONFIG_SPL_I2C_SUPPORT
3627 Support for drivers/i2c/libi2c.o in SPL binary
3629 CONFIG_SPL_GPIO_SUPPORT
3630 Support for drivers/gpio/libgpio.o in SPL binary
3632 CONFIG_SPL_MMC_SUPPORT
3633 Support for drivers/mmc/libmmc.o in SPL binary
3635 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_SECTOR,
3636 CONFIG_SYS_U_BOOT_MAX_SIZE_SECTORS,
3637 Address and partition on the MMC to load U-Boot from
3638 when the MMC is being used in raw mode.
3640 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_PARTITION
3641 Partition on the MMC to load U-Boot from when the MMC is being
3644 CONFIG_SYS_MMCSD_RAW_MODE_KERNEL_SECTOR
3645 Sector to load kernel uImage from when MMC is being
3646 used in raw mode (for Falcon mode)
3648 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTOR,
3649 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTORS
3650 Sector and number of sectors to load kernel argument
3651 parameters from when MMC is being used in raw mode
3654 CONFIG_SYS_MMCSD_FS_BOOT_PARTITION
3655 Partition on the MMC to load U-Boot from when the MMC is being
3658 CONFIG_SPL_FAT_SUPPORT
3659 Support for fs/fat/libfat.o in SPL binary
3661 CONFIG_SPL_EXT_SUPPORT
3662 Support for EXT filesystem in SPL binary
3664 CONFIG_SPL_FS_LOAD_PAYLOAD_NAME
3665 Filename to read to load U-Boot when reading from filesystem
3667 CONFIG_SPL_FS_LOAD_KERNEL_NAME
3668 Filename to read to load kernel uImage when reading
3669 from filesystem (for Falcon mode)
3671 CONFIG_SPL_FS_LOAD_ARGS_NAME
3672 Filename to read to load kernel argument parameters
3673 when reading from filesystem (for Falcon mode)
3675 CONFIG_SPL_MPC83XX_WAIT_FOR_NAND
3676 Set this for NAND SPL on PPC mpc83xx targets, so that
3677 start.S waits for the rest of the SPL to load before
3678 continuing (the hardware starts execution after just
3679 loading the first page rather than the full 4K).
3681 CONFIG_SPL_SKIP_RELOCATE
3682 Avoid SPL relocation
3684 CONFIG_SPL_NAND_BASE
3685 Include nand_base.c in the SPL. Requires
3686 CONFIG_SPL_NAND_DRIVERS.
3688 CONFIG_SPL_NAND_DRIVERS
3689 SPL uses normal NAND drivers, not minimal drivers.
3692 Include standard software ECC in the SPL
3694 CONFIG_SPL_NAND_SIMPLE
3695 Support for NAND boot using simple NAND drivers that
3696 expose the cmd_ctrl() interface.
3698 CONFIG_SPL_MTD_SUPPORT
3699 Support for the MTD subsystem within SPL. Useful for
3700 environment on NAND support within SPL.
3702 CONFIG_SPL_NAND_RAW_ONLY
3703 Support to boot only raw u-boot.bin images. Use this only
3704 if you need to save space.
3706 CONFIG_SPL_MPC8XXX_INIT_DDR_SUPPORT
3707 Set for the SPL on PPC mpc8xxx targets, support for
3708 drivers/ddr/fsl/libddr.o in SPL binary.
3710 CONFIG_SPL_COMMON_INIT_DDR
3711 Set for common ddr init with serial presence detect in
3714 CONFIG_SYS_NAND_5_ADDR_CYCLE, CONFIG_SYS_NAND_PAGE_COUNT,
3715 CONFIG_SYS_NAND_PAGE_SIZE, CONFIG_SYS_NAND_OOBSIZE,
3716 CONFIG_SYS_NAND_BLOCK_SIZE, CONFIG_SYS_NAND_BAD_BLOCK_POS,
3717 CONFIG_SYS_NAND_ECCPOS, CONFIG_SYS_NAND_ECCSIZE,
3718 CONFIG_SYS_NAND_ECCBYTES
3719 Defines the size and behavior of the NAND that SPL uses
3722 CONFIG_SPL_NAND_BOOT
3723 Add support NAND boot
3725 CONFIG_SYS_NAND_U_BOOT_OFFS
3726 Location in NAND to read U-Boot from
3728 CONFIG_SYS_NAND_U_BOOT_DST
3729 Location in memory to load U-Boot to
3731 CONFIG_SYS_NAND_U_BOOT_SIZE
3732 Size of image to load
3734 CONFIG_SYS_NAND_U_BOOT_START
3735 Entry point in loaded image to jump to
3737 CONFIG_SYS_NAND_HW_ECC_OOBFIRST
3738 Define this if you need to first read the OOB and then the
3739 data. This is used, for example, on davinci platforms.
3741 CONFIG_SPL_OMAP3_ID_NAND
3742 Support for an OMAP3-specific set of functions to return the
3743 ID and MFR of the first attached NAND chip, if present.
3745 CONFIG_SPL_SERIAL_SUPPORT
3746 Support for drivers/serial/libserial.o in SPL binary
3748 CONFIG_SPL_SPI_FLASH_SUPPORT
3749 Support for drivers/mtd/spi/libspi_flash.o in SPL binary
3751 CONFIG_SPL_SPI_SUPPORT
3752 Support for drivers/spi/libspi.o in SPL binary
3754 CONFIG_SPL_RAM_DEVICE
3755 Support for running image already present in ram, in SPL binary
3757 CONFIG_SPL_LIBGENERIC_SUPPORT
3758 Support for lib/libgeneric.o in SPL binary
3760 CONFIG_SPL_ENV_SUPPORT
3761 Support for the environment operating in SPL binary
3763 CONFIG_SPL_NET_SUPPORT
3764 Support for the net/libnet.o in SPL binary.
3765 It conflicts with SPL env from storage medium specified by
3766 CONFIG_ENV_IS_xxx but CONFIG_ENV_IS_NOWHERE
3769 Image offset to which the SPL should be padded before appending
3770 the SPL payload. By default, this is defined as
3771 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3772 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3773 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3776 Final target image containing SPL and payload. Some SPLs
3777 use an arch-specific makefile fragment instead, for
3778 example if more than one image needs to be produced.
3780 CONFIG_FIT_SPL_PRINT
3781 Printing information about a FIT image adds quite a bit of
3782 code to SPL. So this is normally disabled in SPL. Use this
3783 option to re-enable it. This will affect the output of the
3784 bootm command when booting a FIT image.
3788 Enable building of TPL globally.
3791 Image offset to which the TPL should be padded before appending
3792 the TPL payload. By default, this is defined as
3793 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3794 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3795 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3800 [so far only for SMDK2400 boards]
3802 - Modem support enable:
3803 CONFIG_MODEM_SUPPORT
3805 - RTS/CTS Flow control enable:
3808 - Modem debug support:
3809 CONFIG_MODEM_SUPPORT_DEBUG
3811 Enables debugging stuff (char screen[1024], dbg())
3812 for modem support. Useful only with BDI2000.
3814 - Interrupt support (PPC):
3816 There are common interrupt_init() and timer_interrupt()
3817 for all PPC archs. interrupt_init() calls interrupt_init_cpu()
3818 for CPU specific initialization. interrupt_init_cpu()
3819 should set decrementer_count to appropriate value. If
3820 CPU resets decrementer automatically after interrupt
3821 (ppc4xx) it should set decrementer_count to zero.
3822 timer_interrupt() calls timer_interrupt_cpu() for CPU
3823 specific handling. If board has watchdog / status_led
3824 / other_activity_monitor it works automatically from
3825 general timer_interrupt().
3829 In the target system modem support is enabled when a
3830 specific key (key combination) is pressed during
3831 power-on. Otherwise U-Boot will boot normally
3832 (autoboot). The key_pressed() function is called from
3833 board_init(). Currently key_pressed() is a dummy
3834 function, returning 1 and thus enabling modem
3837 If there are no modem init strings in the
3838 environment, U-Boot proceed to autoboot; the
3839 previous output (banner, info printfs) will be
3842 See also: doc/README.Modem
3844 Board initialization settings:
3845 ------------------------------
3847 During Initialization u-boot calls a number of board specific functions
3848 to allow the preparation of board specific prerequisites, e.g. pin setup
3849 before drivers are initialized. To enable these callbacks the
3850 following configuration macros have to be defined. Currently this is
3851 architecture specific, so please check arch/your_architecture/lib/board.c
3852 typically in board_init_f() and board_init_r().
3854 - CONFIG_BOARD_EARLY_INIT_F: Call board_early_init_f()
3855 - CONFIG_BOARD_EARLY_INIT_R: Call board_early_init_r()
3856 - CONFIG_BOARD_LATE_INIT: Call board_late_init()
3857 - CONFIG_BOARD_POSTCLK_INIT: Call board_postclk_init()
3859 Configuration Settings:
3860 -----------------------
3862 - CONFIG_SYS_SUPPORT_64BIT_DATA: Defined automatically if compiled as 64-bit.
3863 Optionally it can be defined to support 64-bit memory commands.
3865 - CONFIG_SYS_LONGHELP: Defined when you want long help messages included;
3866 undefine this when you're short of memory.
3868 - CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default
3869 width of the commands listed in the 'help' command output.
3871 - CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to
3872 prompt for user input.
3874 - CONFIG_SYS_CBSIZE: Buffer size for input from the Console
3876 - CONFIG_SYS_PBSIZE: Buffer size for Console output
3878 - CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands
3880 - CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to
3881 the application (usually a Linux kernel) when it is
3884 - CONFIG_SYS_BAUDRATE_TABLE:
3885 List of legal baudrate settings for this board.
3887 - CONFIG_SYS_CONSOLE_INFO_QUIET
3888 Suppress display of console information at boot.
3890 - CONFIG_SYS_CONSOLE_IS_IN_ENV
3891 If the board specific function
3892 extern int overwrite_console (void);
3893 returns 1, the stdin, stderr and stdout are switched to the
3894 serial port, else the settings in the environment are used.
3896 - CONFIG_SYS_CONSOLE_OVERWRITE_ROUTINE
3897 Enable the call to overwrite_console().
3899 - CONFIG_SYS_CONSOLE_ENV_OVERWRITE
3900 Enable overwrite of previous console environment settings.
3902 - CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END:
3903 Begin and End addresses of the area used by the
3906 - CONFIG_SYS_ALT_MEMTEST:
3907 Enable an alternate, more extensive memory test.
3909 - CONFIG_SYS_MEMTEST_SCRATCH:
3910 Scratch address used by the alternate memory test
3911 You only need to set this if address zero isn't writeable
3913 - CONFIG_SYS_MEM_TOP_HIDE (PPC only):
3914 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header,
3915 this specified memory area will get subtracted from the top
3916 (end) of RAM and won't get "touched" at all by U-Boot. By
3917 fixing up gd->ram_size the Linux kernel should gets passed
3918 the now "corrected" memory size and won't touch it either.
3919 This should work for arch/ppc and arch/powerpc. Only Linux
3920 board ports in arch/powerpc with bootwrapper support that
3921 recalculate the memory size from the SDRAM controller setup
3922 will have to get fixed in Linux additionally.
3924 This option can be used as a workaround for the 440EPx/GRx
3925 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't
3928 WARNING: Please make sure that this value is a multiple of
3929 the Linux page size (normally 4k). If this is not the case,
3930 then the end address of the Linux memory will be located at a
3931 non page size aligned address and this could cause major
3934 - CONFIG_SYS_LOADS_BAUD_CHANGE:
3935 Enable temporary baudrate change while serial download
3937 - CONFIG_SYS_SDRAM_BASE:
3938 Physical start address of SDRAM. _Must_ be 0 here.
3940 - CONFIG_SYS_MBIO_BASE:
3941 Physical start address of Motherboard I/O (if using a
3944 - CONFIG_SYS_FLASH_BASE:
3945 Physical start address of Flash memory.
3947 - CONFIG_SYS_MONITOR_BASE:
3948 Physical start address of boot monitor code (set by
3949 make config files to be same as the text base address
3950 (CONFIG_SYS_TEXT_BASE) used when linking) - same as
3951 CONFIG_SYS_FLASH_BASE when booting from flash.
3953 - CONFIG_SYS_MONITOR_LEN:
3954 Size of memory reserved for monitor code, used to
3955 determine _at_compile_time_ (!) if the environment is
3956 embedded within the U-Boot image, or in a separate
3959 - CONFIG_SYS_MALLOC_LEN:
3960 Size of DRAM reserved for malloc() use.
3962 - CONFIG_SYS_MALLOC_F_LEN
3963 Size of the malloc() pool for use before relocation. If
3964 this is defined, then a very simple malloc() implementation
3965 will become available before relocation. The address is just
3966 below the global data, and the stack is moved down to make
3969 This feature allocates regions with increasing addresses
3970 within the region. calloc() is supported, but realloc()
3971 is not available. free() is supported but does nothing.
3972 The memory will be freed (or in fact just forgotten) when
3973 U-Boot relocates itself.
3975 Pre-relocation malloc() is only supported on ARM and sandbox
3976 at present but is fairly easy to enable for other archs.
3978 - CONFIG_SYS_MALLOC_SIMPLE
3979 Provides a simple and small malloc() and calloc() for those
3980 boards which do not use the full malloc in SPL (which is
3981 enabled with CONFIG_SYS_SPL_MALLOC_START).
3983 - CONFIG_SYS_NONCACHED_MEMORY:
3984 Size of non-cached memory area. This area of memory will be
3985 typically located right below the malloc() area and mapped
3986 uncached in the MMU. This is useful for drivers that would
3987 otherwise require a lot of explicit cache maintenance. For
3988 some drivers it's also impossible to properly maintain the
3989 cache. For example if the regions that need to be flushed
3990 are not a multiple of the cache-line size, *and* padding
3991 cannot be allocated between the regions to align them (i.e.
3992 if the HW requires a contiguous array of regions, and the
3993 size of each region is not cache-aligned), then a flush of
3994 one region may result in overwriting data that hardware has
3995 written to another region in the same cache-line. This can
3996 happen for example in network drivers where descriptors for
3997 buffers are typically smaller than the CPU cache-line (e.g.
3998 16 bytes vs. 32 or 64 bytes).
4000 Non-cached memory is only supported on 32-bit ARM at present.
4002 - CONFIG_SYS_BOOTM_LEN:
4003 Normally compressed uImages are limited to an
4004 uncompressed size of 8 MBytes. If this is not enough,
4005 you can define CONFIG_SYS_BOOTM_LEN in your board config file
4006 to adjust this setting to your needs.
4008 - CONFIG_SYS_BOOTMAPSZ:
4009 Maximum size of memory mapped by the startup code of
4010 the Linux kernel; all data that must be processed by
4011 the Linux kernel (bd_info, boot arguments, FDT blob if
4012 used) must be put below this limit, unless "bootm_low"
4013 environment variable is defined and non-zero. In such case
4014 all data for the Linux kernel must be between "bootm_low"
4015 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ. The environment
4016 variable "bootm_mapsize" will override the value of
4017 CONFIG_SYS_BOOTMAPSZ. If CONFIG_SYS_BOOTMAPSZ is undefined,
4018 then the value in "bootm_size" will be used instead.
4020 - CONFIG_SYS_BOOT_RAMDISK_HIGH:
4021 Enable initrd_high functionality. If defined then the
4022 initrd_high feature is enabled and the bootm ramdisk subcommand
4025 - CONFIG_SYS_BOOT_GET_CMDLINE:
4026 Enables allocating and saving kernel cmdline in space between
4027 "bootm_low" and "bootm_low" + BOOTMAPSZ.
4029 - CONFIG_SYS_BOOT_GET_KBD:
4030 Enables allocating and saving a kernel copy of the bd_info in
4031 space between "bootm_low" and "bootm_low" + BOOTMAPSZ.
4033 - CONFIG_SYS_MAX_FLASH_BANKS:
4034 Max number of Flash memory banks
4036 - CONFIG_SYS_MAX_FLASH_SECT:
4037 Max number of sectors on a Flash chip
4039 - CONFIG_SYS_FLASH_ERASE_TOUT:
4040 Timeout for Flash erase operations (in ms)
4042 - CONFIG_SYS_FLASH_WRITE_TOUT:
4043 Timeout for Flash write operations (in ms)
4045 - CONFIG_SYS_FLASH_LOCK_TOUT
4046 Timeout for Flash set sector lock bit operation (in ms)
4048 - CONFIG_SYS_FLASH_UNLOCK_TOUT
4049 Timeout for Flash clear lock bits operation (in ms)
4051 - CONFIG_SYS_FLASH_PROTECTION
4052 If defined, hardware flash sectors protection is used
4053 instead of U-Boot software protection.
4055 - CONFIG_SYS_DIRECT_FLASH_TFTP:
4057 Enable TFTP transfers directly to flash memory;
4058 without this option such a download has to be
4059 performed in two steps: (1) download to RAM, and (2)
4060 copy from RAM to flash.
4062 The two-step approach is usually more reliable, since
4063 you can check if the download worked before you erase
4064 the flash, but in some situations (when system RAM is
4065 too limited to allow for a temporary copy of the
4066 downloaded image) this option may be very useful.
4068 - CONFIG_SYS_FLASH_CFI:
4069 Define if the flash driver uses extra elements in the
4070 common flash structure for storing flash geometry.
4072 - CONFIG_FLASH_CFI_DRIVER
4073 This option also enables the building of the cfi_flash driver
4074 in the drivers directory
4076 - CONFIG_FLASH_CFI_MTD
4077 This option enables the building of the cfi_mtd driver
4078 in the drivers directory. The driver exports CFI flash
4081 - CONFIG_SYS_FLASH_USE_BUFFER_WRITE
4082 Use buffered writes to flash.
4084 - CONFIG_FLASH_SPANSION_S29WS_N
4085 s29ws-n MirrorBit flash has non-standard addresses for buffered
4088 - CONFIG_SYS_FLASH_QUIET_TEST
4089 If this option is defined, the common CFI flash doesn't
4090 print it's warning upon not recognized FLASH banks. This
4091 is useful, if some of the configured banks are only
4092 optionally available.
4094 - CONFIG_FLASH_SHOW_PROGRESS
4095 If defined (must be an integer), print out countdown
4096 digits and dots. Recommended value: 45 (9..1) for 80
4097 column displays, 15 (3..1) for 40 column displays.
4099 - CONFIG_FLASH_VERIFY
4100 If defined, the content of the flash (destination) is compared
4101 against the source after the write operation. An error message
4102 will be printed when the contents are not identical.
4103 Please note that this option is useless in nearly all cases,
4104 since such flash programming errors usually are detected earlier
4105 while unprotecting/erasing/programming. Please only enable
4106 this option if you really know what you are doing.
4108 - CONFIG_SYS_RX_ETH_BUFFER:
4109 Defines the number of Ethernet receive buffers. On some
4110 Ethernet controllers it is recommended to set this value
4111 to 8 or even higher (EEPRO100 or 405 EMAC), since all
4112 buffers can be full shortly after enabling the interface
4113 on high Ethernet traffic.
4114 Defaults to 4 if not defined.
4116 - CONFIG_ENV_MAX_ENTRIES
4118 Maximum number of entries in the hash table that is used
4119 internally to store the environment settings. The default
4120 setting is supposed to be generous and should work in most
4121 cases. This setting can be used to tune behaviour; see
4122 lib/hashtable.c for details.
4124 - CONFIG_ENV_FLAGS_LIST_DEFAULT
4125 - CONFIG_ENV_FLAGS_LIST_STATIC
4126 Enable validation of the values given to environment variables when
4127 calling env set. Variables can be restricted to only decimal,
4128 hexadecimal, or boolean. If CONFIG_CMD_NET is also defined,
4129 the variables can also be restricted to IP address or MAC address.
4131 The format of the list is:
4132 type_attribute = [s|d|x|b|i|m]
4133 access_attribute = [a|r|o|c]
4134 attributes = type_attribute[access_attribute]
4135 entry = variable_name[:attributes]
4138 The type attributes are:
4139 s - String (default)
4142 b - Boolean ([1yYtT|0nNfF])
4146 The access attributes are:
4152 - CONFIG_ENV_FLAGS_LIST_DEFAULT
4153 Define this to a list (string) to define the ".flags"
4154 environment variable in the default or embedded environment.
4156 - CONFIG_ENV_FLAGS_LIST_STATIC
4157 Define this to a list (string) to define validation that
4158 should be done if an entry is not found in the ".flags"
4159 environment variable. To override a setting in the static
4160 list, simply add an entry for the same variable name to the
4163 If CONFIG_REGEX is defined, the variable_name above is evaluated as a
4164 regular expression. This allows multiple variables to define the same
4165 flags without explicitly listing them for each variable.
4167 - CONFIG_ENV_ACCESS_IGNORE_FORCE
4168 If defined, don't allow the -f switch to env set override variable
4171 - CONFIG_SYS_GENERIC_BOARD
4172 This selects the architecture-generic board system instead of the
4173 architecture-specific board files. It is intended to move boards
4174 to this new framework over time. Defining this will disable the
4175 arch/foo/lib/board.c file and use common/board_f.c and
4176 common/board_r.c instead. To use this option your architecture
4177 must support it (i.e. must select HAVE_GENERIC_BOARD in arch/Kconfig).
4178 If you find problems enabling this option on your board please report
4179 the problem and send patches!
4181 - CONFIG_OMAP_PLATFORM_RESET_TIME_MAX_USEC (OMAP only)
4182 This is set by OMAP boards for the max time that reset should
4183 be asserted. See doc/README.omap-reset-time for details on how
4184 the value can be calculated on a given board.
4187 If stdint.h is available with your toolchain you can define this
4188 option to enable it. You can provide option 'USE_STDINT=1' when
4189 building U-Boot to enable this.
4191 The following definitions that deal with the placement and management
4192 of environment data (variable area); in general, we support the
4193 following configurations:
4195 - CONFIG_BUILD_ENVCRC:
4197 Builds up envcrc with the target environment so that external utils
4198 may easily extract it and embed it in final U-Boot images.
4200 - CONFIG_ENV_IS_IN_FLASH:
4202 Define this if the environment is in flash memory.
4204 a) The environment occupies one whole flash sector, which is
4205 "embedded" in the text segment with the U-Boot code. This
4206 happens usually with "bottom boot sector" or "top boot
4207 sector" type flash chips, which have several smaller
4208 sectors at the start or the end. For instance, such a
4209 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In
4210 such a case you would place the environment in one of the
4211 4 kB sectors - with U-Boot code before and after it. With
4212 "top boot sector" type flash chips, you would put the
4213 environment in one of the last sectors, leaving a gap
4214 between U-Boot and the environment.
4216 - CONFIG_ENV_OFFSET:
4218 Offset of environment data (variable area) to the
4219 beginning of flash memory; for instance, with bottom boot
4220 type flash chips the second sector can be used: the offset
4221 for this sector is given here.
4223 CONFIG_ENV_OFFSET is used relative to CONFIG_SYS_FLASH_BASE.
4227 This is just another way to specify the start address of
4228 the flash sector containing the environment (instead of
4231 - CONFIG_ENV_SECT_SIZE:
4233 Size of the sector containing the environment.
4236 b) Sometimes flash chips have few, equal sized, BIG sectors.
4237 In such a case you don't want to spend a whole sector for
4242 If you use this in combination with CONFIG_ENV_IS_IN_FLASH
4243 and CONFIG_ENV_SECT_SIZE, you can specify to use only a part
4244 of this flash sector for the environment. This saves
4245 memory for the RAM copy of the environment.
4247 It may also save flash memory if you decide to use this
4248 when your environment is "embedded" within U-Boot code,
4249 since then the remainder of the flash sector could be used
4250 for U-Boot code. It should be pointed out that this is
4251 STRONGLY DISCOURAGED from a robustness point of view:
4252 updating the environment in flash makes it always
4253 necessary to erase the WHOLE sector. If something goes
4254 wrong before the contents has been restored from a copy in
4255 RAM, your target system will be dead.
4257 - CONFIG_ENV_ADDR_REDUND
4258 CONFIG_ENV_SIZE_REDUND
4260 These settings describe a second storage area used to hold
4261 a redundant copy of the environment data, so that there is
4262 a valid backup copy in case there is a power failure during
4263 a "saveenv" operation.
4265 BE CAREFUL! Any changes to the flash layout, and some changes to the
4266 source code will make it necessary to adapt <board>/u-boot.lds*
4270 - CONFIG_ENV_IS_IN_NVRAM:
4272 Define this if you have some non-volatile memory device
4273 (NVRAM, battery buffered SRAM) which you want to use for the
4279 These two #defines are used to determine the memory area you
4280 want to use for environment. It is assumed that this memory
4281 can just be read and written to, without any special
4284 BE CAREFUL! The first access to the environment happens quite early
4285 in U-Boot initialization (when we try to get the setting of for the
4286 console baudrate). You *MUST* have mapped your NVRAM area then, or
4289 Please note that even with NVRAM we still use a copy of the
4290 environment in RAM: we could work on NVRAM directly, but we want to
4291 keep settings there always unmodified except somebody uses "saveenv"
4292 to save the current settings.
4295 - CONFIG_ENV_IS_IN_EEPROM:
4297 Use this if you have an EEPROM or similar serial access
4298 device and a driver for it.
4300 - CONFIG_ENV_OFFSET:
4303 These two #defines specify the offset and size of the
4304 environment area within the total memory of your EEPROM.
4306 - CONFIG_SYS_I2C_EEPROM_ADDR:
4307 If defined, specified the chip address of the EEPROM device.
4308 The default address is zero.
4310 - CONFIG_SYS_I2C_EEPROM_BUS:
4311 If defined, specified the i2c bus of the EEPROM device.
4313 - CONFIG_SYS_EEPROM_PAGE_WRITE_BITS:
4314 If defined, the number of bits used to address bytes in a
4315 single page in the EEPROM device. A 64 byte page, for example
4316 would require six bits.
4318 - CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS:
4319 If defined, the number of milliseconds to delay between
4320 page writes. The default is zero milliseconds.
4322 - CONFIG_SYS_I2C_EEPROM_ADDR_LEN:
4323 The length in bytes of the EEPROM memory array address. Note
4324 that this is NOT the chip address length!
4326 - CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW:
4327 EEPROM chips that implement "address overflow" are ones
4328 like Catalyst 24WC04/08/16 which has 9/10/11 bits of
4329 address and the extra bits end up in the "chip address" bit
4330 slots. This makes a 24WC08 (1Kbyte) chip look like four 256
4333 Note that we consider the length of the address field to
4334 still be one byte because the extra address bits are hidden
4335 in the chip address.
4337 - CONFIG_SYS_EEPROM_SIZE:
4338 The size in bytes of the EEPROM device.
4340 - CONFIG_ENV_EEPROM_IS_ON_I2C
4341 define this, if you have I2C and SPI activated, and your
4342 EEPROM, which holds the environment, is on the I2C bus.
4344 - CONFIG_I2C_ENV_EEPROM_BUS
4345 if you have an Environment on an EEPROM reached over
4346 I2C muxes, you can define here, how to reach this
4347 EEPROM. For example:
4349 #define CONFIG_I2C_ENV_EEPROM_BUS 1
4351 EEPROM which holds the environment, is reached over
4352 a pca9547 i2c mux with address 0x70, channel 3.
4354 - CONFIG_ENV_IS_IN_DATAFLASH:
4356 Define this if you have a DataFlash memory device which you
4357 want to use for the environment.
4359 - CONFIG_ENV_OFFSET:
4363 These three #defines specify the offset and size of the
4364 environment area within the total memory of your DataFlash placed
4365 at the specified address.
4367 - CONFIG_ENV_IS_IN_SPI_FLASH:
4369 Define this if you have a SPI Flash memory device which you
4370 want to use for the environment.
4372 - CONFIG_ENV_OFFSET:
4375 These two #defines specify the offset and size of the
4376 environment area within the SPI Flash. CONFIG_ENV_OFFSET must be
4377 aligned to an erase sector boundary.
4379 - CONFIG_ENV_SECT_SIZE:
4381 Define the SPI flash's sector size.
4383 - CONFIG_ENV_OFFSET_REDUND (optional):
4385 This setting describes a second storage area of CONFIG_ENV_SIZE
4386 size used to hold a redundant copy of the environment data, so
4387 that there is a valid backup copy in case there is a power failure
4388 during a "saveenv" operation. CONFIG_ENV_OFFSET_RENDUND must be
4389 aligned to an erase sector boundary.
4391 - CONFIG_ENV_SPI_BUS (optional):
4392 - CONFIG_ENV_SPI_CS (optional):
4394 Define the SPI bus and chip select. If not defined they will be 0.
4396 - CONFIG_ENV_SPI_MAX_HZ (optional):
4398 Define the SPI max work clock. If not defined then use 1MHz.
4400 - CONFIG_ENV_SPI_MODE (optional):
4402 Define the SPI work mode. If not defined then use SPI_MODE_3.
4404 - CONFIG_ENV_IS_IN_REMOTE:
4406 Define this if you have a remote memory space which you
4407 want to use for the local device's environment.
4412 These two #defines specify the address and size of the
4413 environment area within the remote memory space. The
4414 local device can get the environment from remote memory
4415 space by SRIO or PCIE links.
4417 BE CAREFUL! For some special cases, the local device can not use
4418 "saveenv" command. For example, the local device will get the
4419 environment stored in a remote NOR flash by SRIO or PCIE link,
4420 but it can not erase, write this NOR flash by SRIO or PCIE interface.
4422 - CONFIG_ENV_IS_IN_NAND:
4424 Define this if you have a NAND device which you want to use
4425 for the environment.
4427 - CONFIG_ENV_OFFSET:
4430 These two #defines specify the offset and size of the environment
4431 area within the first NAND device. CONFIG_ENV_OFFSET must be
4432 aligned to an erase block boundary.
4434 - CONFIG_ENV_OFFSET_REDUND (optional):
4436 This setting describes a second storage area of CONFIG_ENV_SIZE
4437 size used to hold a redundant copy of the environment data, so
4438 that there is a valid backup copy in case there is a power failure
4439 during a "saveenv" operation. CONFIG_ENV_OFFSET_RENDUND must be
4440 aligned to an erase block boundary.
4442 - CONFIG_ENV_RANGE (optional):
4444 Specifies the length of the region in which the environment
4445 can be written. This should be a multiple of the NAND device's
4446 block size. Specifying a range with more erase blocks than
4447 are needed to hold CONFIG_ENV_SIZE allows bad blocks within
4448 the range to be avoided.
4450 - CONFIG_ENV_OFFSET_OOB (optional):
4452 Enables support for dynamically retrieving the offset of the
4453 environment from block zero's out-of-band data. The
4454 "nand env.oob" command can be used to record this offset.
4455 Currently, CONFIG_ENV_OFFSET_REDUND is not supported when
4456 using CONFIG_ENV_OFFSET_OOB.
4458 - CONFIG_NAND_ENV_DST
4460 Defines address in RAM to which the nand_spl code should copy the
4461 environment. If redundant environment is used, it will be copied to
4462 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE.
4464 - CONFIG_ENV_IS_IN_UBI:
4466 Define this if you have an UBI volume that you want to use for the
4467 environment. This has the benefit of wear-leveling the environment
4468 accesses, which is important on NAND.
4470 - CONFIG_ENV_UBI_PART:
4472 Define this to a string that is the mtd partition containing the UBI.
4474 - CONFIG_ENV_UBI_VOLUME:
4476 Define this to the name of the volume that you want to store the
4479 - CONFIG_ENV_UBI_VOLUME_REDUND:
4481 Define this to the name of another volume to store a second copy of
4482 the environment in. This will enable redundant environments in UBI.
4483 It is assumed that both volumes are in the same MTD partition.
4485 - CONFIG_UBI_SILENCE_MSG
4486 - CONFIG_UBIFS_SILENCE_MSG
4488 You will probably want to define these to avoid a really noisy system
4489 when storing the env in UBI.
4491 - CONFIG_ENV_IS_IN_FAT:
4492 Define this if you want to use the FAT file system for the environment.
4494 - FAT_ENV_INTERFACE:
4496 Define this to a string that is the name of the block device.
4498 - FAT_ENV_DEV_AND_PART:
4500 Define this to a string to specify the partition of the device. It can
4503 "D:P", "D:0", "D", "D:" or "D:auto" (D, P are integers. And P >= 1)
4504 - "D:P": device D partition P. Error occurs if device D has no
4507 - "D" or "D:": device D partition 1 if device D has partition
4508 table, or the whole device D if has no partition
4510 - "D:auto": first partition in device D with bootable flag set.
4511 If none, first valid partition in device D. If no
4512 partition table then means device D.
4516 It's a string of the FAT file name. This file use to store the
4520 This should be defined. Otherwise it cannot save the environment file.
4522 - CONFIG_ENV_IS_IN_MMC:
4524 Define this if you have an MMC device which you want to use for the
4527 - CONFIG_SYS_MMC_ENV_DEV:
4529 Specifies which MMC device the environment is stored in.
4531 - CONFIG_SYS_MMC_ENV_PART (optional):
4533 Specifies which MMC partition the environment is stored in. If not
4534 set, defaults to partition 0, the user area. Common values might be
4535 1 (first MMC boot partition), 2 (second MMC boot partition).
4537 - CONFIG_ENV_OFFSET:
4540 These two #defines specify the offset and size of the environment
4541 area within the specified MMC device.
4543 If offset is positive (the usual case), it is treated as relative to
4544 the start of the MMC partition. If offset is negative, it is treated
4545 as relative to the end of the MMC partition. This can be useful if
4546 your board may be fitted with different MMC devices, which have
4547 different sizes for the MMC partitions, and you always want the
4548 environment placed at the very end of the partition, to leave the
4549 maximum possible space before it, to store other data.
4551 These two values are in units of bytes, but must be aligned to an
4552 MMC sector boundary.
4554 - CONFIG_ENV_OFFSET_REDUND (optional):
4556 Specifies a second storage area, of CONFIG_ENV_SIZE size, used to
4557 hold a redundant copy of the environment data. This provides a
4558 valid backup copy in case the other copy is corrupted, e.g. due
4559 to a power failure during a "saveenv" operation.
4561 This value may also be positive or negative; this is handled in the
4562 same way as CONFIG_ENV_OFFSET.
4564 This value is also in units of bytes, but must also be aligned to
4565 an MMC sector boundary.
4567 - CONFIG_ENV_SIZE_REDUND (optional):
4569 This value need not be set, even when CONFIG_ENV_OFFSET_REDUND is
4570 set. If this value is set, it must be set to the same value as
4573 - CONFIG_SYS_SPI_INIT_OFFSET
4575 Defines offset to the initial SPI buffer area in DPRAM. The
4576 area is used at an early stage (ROM part) if the environment
4577 is configured to reside in the SPI EEPROM: We need a 520 byte
4578 scratch DPRAM area. It is used between the two initialization
4579 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems
4580 to be a good choice since it makes it far enough from the
4581 start of the data area as well as from the stack pointer.
4583 Please note that the environment is read-only until the monitor
4584 has been relocated to RAM and a RAM copy of the environment has been
4585 created; also, when using EEPROM you will have to use getenv_f()
4586 until then to read environment variables.
4588 The environment is protected by a CRC32 checksum. Before the monitor
4589 is relocated into RAM, as a result of a bad CRC you will be working
4590 with the compiled-in default environment - *silently*!!! [This is
4591 necessary, because the first environment variable we need is the
4592 "baudrate" setting for the console - if we have a bad CRC, we don't
4593 have any device yet where we could complain.]
4595 Note: once the monitor has been relocated, then it will complain if
4596 the default environment is used; a new CRC is computed as soon as you
4597 use the "saveenv" command to store a valid environment.
4599 - CONFIG_SYS_FAULT_ECHO_LINK_DOWN:
4600 Echo the inverted Ethernet link state to the fault LED.
4602 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR
4603 also needs to be defined.
4605 - CONFIG_SYS_FAULT_MII_ADDR:
4606 MII address of the PHY to check for the Ethernet link state.
4608 - CONFIG_NS16550_MIN_FUNCTIONS:
4609 Define this if you desire to only have use of the NS16550_init
4610 and NS16550_putc functions for the serial driver located at
4611 drivers/serial/ns16550.c. This option is useful for saving
4612 space for already greatly restricted images, including but not
4613 limited to NAND_SPL configurations.
4615 - CONFIG_DISPLAY_BOARDINFO
4616 Display information about the board that U-Boot is running on
4617 when U-Boot starts up. The board function checkboard() is called
4620 - CONFIG_DISPLAY_BOARDINFO_LATE
4621 Similar to the previous option, but display this information
4622 later, once stdio is running and output goes to the LCD, if
4625 - CONFIG_BOARD_SIZE_LIMIT:
4626 Maximum size of the U-Boot image. When defined, the
4627 build system checks that the actual size does not
4630 Low Level (hardware related) configuration options:
4631 ---------------------------------------------------
4633 - CONFIG_SYS_CACHELINE_SIZE:
4634 Cache Line Size of the CPU.
4636 - CONFIG_SYS_DEFAULT_IMMR:
4637 Default address of the IMMR after system reset.
4639 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU,
4640 and RPXsuper) to be able to adjust the position of
4641 the IMMR register after a reset.
4643 - CONFIG_SYS_CCSRBAR_DEFAULT:
4644 Default (power-on reset) physical address of CCSR on Freescale
4647 - CONFIG_SYS_CCSRBAR:
4648 Virtual address of CCSR. On a 32-bit build, this is typically
4649 the same value as CONFIG_SYS_CCSRBAR_DEFAULT.
4651 CONFIG_SYS_DEFAULT_IMMR must also be set to this value,
4652 for cross-platform code that uses that macro instead.
4654 - CONFIG_SYS_CCSRBAR_PHYS:
4655 Physical address of CCSR. CCSR can be relocated to a new
4656 physical address, if desired. In this case, this macro should
4657 be set to that address. Otherwise, it should be set to the
4658 same value as CONFIG_SYS_CCSRBAR_DEFAULT. For example, CCSR
4659 is typically relocated on 36-bit builds. It is recommended
4660 that this macro be defined via the _HIGH and _LOW macros:
4662 #define CONFIG_SYS_CCSRBAR_PHYS ((CONFIG_SYS_CCSRBAR_PHYS_HIGH
4663 * 1ull) << 32 | CONFIG_SYS_CCSRBAR_PHYS_LOW)
4665 - CONFIG_SYS_CCSRBAR_PHYS_HIGH:
4666 Bits 33-36 of CONFIG_SYS_CCSRBAR_PHYS. This value is typically
4667 either 0 (32-bit build) or 0xF (36-bit build). This macro is
4668 used in assembly code, so it must not contain typecasts or
4669 integer size suffixes (e.g. "ULL").
4671 - CONFIG_SYS_CCSRBAR_PHYS_LOW:
4672 Lower 32-bits of CONFIG_SYS_CCSRBAR_PHYS. This macro is
4673 used in assembly code, so it must not contain typecasts or
4674 integer size suffixes (e.g. "ULL").
4676 - CONFIG_SYS_CCSR_DO_NOT_RELOCATE:
4677 If this macro is defined, then CONFIG_SYS_CCSRBAR_PHYS will be
4678 forced to a value that ensures that CCSR is not relocated.
4680 - Floppy Disk Support:
4681 CONFIG_SYS_FDC_DRIVE_NUMBER
4683 the default drive number (default value 0)
4685 CONFIG_SYS_ISA_IO_STRIDE
4687 defines the spacing between FDC chipset registers
4690 CONFIG_SYS_ISA_IO_OFFSET
4692 defines the offset of register from address. It
4693 depends on which part of the data bus is connected to
4694 the FDC chipset. (default value 0)
4696 If CONFIG_SYS_ISA_IO_STRIDE CONFIG_SYS_ISA_IO_OFFSET and
4697 CONFIG_SYS_FDC_DRIVE_NUMBER are undefined, they take their
4700 if CONFIG_SYS_FDC_HW_INIT is defined, then the function
4701 fdc_hw_init() is called at the beginning of the FDC
4702 setup. fdc_hw_init() must be provided by the board
4703 source code. It is used to make hardware-dependent
4707 Most IDE controllers were designed to be connected with PCI
4708 interface. Only few of them were designed for AHB interface.
4709 When software is doing ATA command and data transfer to
4710 IDE devices through IDE-AHB controller, some additional
4711 registers accessing to these kind of IDE-AHB controller
4714 - CONFIG_SYS_IMMR: Physical address of the Internal Memory.
4715 DO NOT CHANGE unless you know exactly what you're
4716 doing! (11-4) [MPC8xx/82xx systems only]
4718 - CONFIG_SYS_INIT_RAM_ADDR:
4720 Start address of memory area that can be used for
4721 initial data and stack; please note that this must be
4722 writable memory that is working WITHOUT special
4723 initialization, i. e. you CANNOT use normal RAM which
4724 will become available only after programming the
4725 memory controller and running certain initialization
4728 U-Boot uses the following memory types:
4729 - MPC8xx and MPC8260: IMMR (internal memory of the CPU)
4730 - MPC824X: data cache
4731 - PPC4xx: data cache
4733 - CONFIG_SYS_GBL_DATA_OFFSET:
4735 Offset of the initial data structure in the memory
4736 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually
4737 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial
4738 data is located at the end of the available space
4739 (sometimes written as (CONFIG_SYS_INIT_RAM_SIZE -
4740 CONFIG_SYS_INIT_DATA_SIZE), and the initial stack is just
4741 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR +
4742 CONFIG_SYS_GBL_DATA_OFFSET) downward.
4745 On the MPC824X (or other systems that use the data
4746 cache for initial memory) the address chosen for
4747 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must
4748 point to an otherwise UNUSED address space between
4749 the top of RAM and the start of the PCI space.
4751 - CONFIG_SYS_SIUMCR: SIU Module Configuration (11-6)
4753 - CONFIG_SYS_SYPCR: System Protection Control (11-9)
4755 - CONFIG_SYS_TBSCR: Time Base Status and Control (11-26)
4757 - CONFIG_SYS_PISCR: Periodic Interrupt Status and Control (11-31)
4759 - CONFIG_SYS_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30)
4761 - CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27)
4763 - CONFIG_SYS_OR_TIMING_SDRAM:
4766 - CONFIG_SYS_MAMR_PTA:
4767 periodic timer for refresh
4769 - CONFIG_SYS_DER: Debug Event Register (37-47)
4771 - FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM,
4772 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP,
4773 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM,
4774 CONFIG_SYS_BR1_PRELIM:
4775 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
4777 - SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
4778 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM,
4779 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM:
4780 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
4782 - CONFIG_SYS_MAMR_PTA, CONFIG_SYS_MPTPR_2BK_4K, CONFIG_SYS_MPTPR_1BK_4K, CONFIG_SYS_MPTPR_2BK_8K,
4783 CONFIG_SYS_MPTPR_1BK_8K, CONFIG_SYS_MAMR_8COL, CONFIG_SYS_MAMR_9COL:
4784 Machine Mode Register and Memory Periodic Timer
4785 Prescaler definitions (SDRAM timing)
4787 - CONFIG_SYS_I2C_UCODE_PATCH, CONFIG_SYS_I2C_DPMEM_OFFSET [0x1FC0]:
4788 enable I2C microcode relocation patch (MPC8xx);
4789 define relocation offset in DPRAM [DSP2]
4791 - CONFIG_SYS_SMC_UCODE_PATCH, CONFIG_SYS_SMC_DPMEM_OFFSET [0x1FC0]:
4792 enable SMC microcode relocation patch (MPC8xx);
4793 define relocation offset in DPRAM [SMC1]
4795 - CONFIG_SYS_SPI_UCODE_PATCH, CONFIG_SYS_SPI_DPMEM_OFFSET [0x1FC0]:
4796 enable SPI microcode relocation patch (MPC8xx);
4797 define relocation offset in DPRAM [SCC4]
4799 - CONFIG_SYS_USE_OSCCLK:
4800 Use OSCM clock mode on MBX8xx board. Be careful,
4801 wrong setting might damage your board. Read
4802 doc/README.MBX before setting this variable!
4804 - CONFIG_SYS_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only)
4805 Offset of the bootmode word in DPRAM used by post
4806 (Power On Self Tests). This definition overrides
4807 #define'd default value in commproc.h resp.
4810 - CONFIG_SYS_PCI_SLV_MEM_LOCAL, CONFIG_SYS_PCI_SLV_MEM_BUS, CONFIG_SYS_PICMR0_MASK_ATTRIB,
4811 CONFIG_SYS_PCI_MSTR0_LOCAL, CONFIG_SYS_PCIMSK0_MASK, CONFIG_SYS_PCI_MSTR1_LOCAL,
4812 CONFIG_SYS_PCIMSK1_MASK, CONFIG_SYS_PCI_MSTR_MEM_LOCAL, CONFIG_SYS_PCI_MSTR_MEM_BUS,
4813 CONFIG_SYS_CPU_PCI_MEM_START, CONFIG_SYS_PCI_MSTR_MEM_SIZE, CONFIG_SYS_POCMR0_MASK_ATTRIB,
4814 CONFIG_SYS_PCI_MSTR_MEMIO_LOCAL, CONFIG_SYS_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START,
4815 CONFIG_SYS_PCI_MSTR_MEMIO_SIZE, CONFIG_SYS_POCMR1_MASK_ATTRIB, CONFIG_SYS_PCI_MSTR_IO_LOCAL,
4816 CONFIG_SYS_PCI_MSTR_IO_BUS, CONFIG_SYS_CPU_PCI_IO_START, CONFIG_SYS_PCI_MSTR_IO_SIZE,
4817 CONFIG_SYS_POCMR2_MASK_ATTRIB: (MPC826x only)
4818 Overrides the default PCI memory map in arch/powerpc/cpu/mpc8260/pci.c if set.
4820 - CONFIG_PCI_DISABLE_PCIE:
4821 Disable PCI-Express on systems where it is supported but not
4824 - CONFIG_PCI_ENUM_ONLY
4825 Only scan through and get the devices on the buses.
4826 Don't do any setup work, presumably because someone or
4827 something has already done it, and we don't need to do it
4828 a second time. Useful for platforms that are pre-booted
4829 by coreboot or similar.
4831 - CONFIG_PCI_INDIRECT_BRIDGE:
4832 Enable support for indirect PCI bridges.
4835 Chip has SRIO or not
4838 Board has SRIO 1 port available
4841 Board has SRIO 2 port available
4843 - CONFIG_SRIO_PCIE_BOOT_MASTER
4844 Board can support master function for Boot from SRIO and PCIE
4846 - CONFIG_SYS_SRIOn_MEM_VIRT:
4847 Virtual Address of SRIO port 'n' memory region
4849 - CONFIG_SYS_SRIOn_MEM_PHYS:
4850 Physical Address of SRIO port 'n' memory region
4852 - CONFIG_SYS_SRIOn_MEM_SIZE:
4853 Size of SRIO port 'n' memory region
4855 - CONFIG_SYS_NAND_BUSWIDTH_16BIT
4856 Defined to tell the NAND controller that the NAND chip is using
4858 Not all NAND drivers use this symbol.
4859 Example of drivers that use it:
4860 - drivers/mtd/nand/ndfc.c
4861 - drivers/mtd/nand/mxc_nand.c
4863 - CONFIG_SYS_NDFC_EBC0_CFG
4864 Sets the EBC0_CFG register for the NDFC. If not defined
4865 a default value will be used.
4868 Get DDR timing information from an I2C EEPROM. Common
4869 with pluggable memory modules such as SODIMMs
4872 I2C address of the SPD EEPROM
4874 - CONFIG_SYS_SPD_BUS_NUM
4875 If SPD EEPROM is on an I2C bus other than the first
4876 one, specify here. Note that the value must resolve
4877 to something your driver can deal with.
4879 - CONFIG_SYS_DDR_RAW_TIMING
4880 Get DDR timing information from other than SPD. Common with
4881 soldered DDR chips onboard without SPD. DDR raw timing
4882 parameters are extracted from datasheet and hard-coded into
4883 header files or board specific files.
4885 - CONFIG_FSL_DDR_INTERACTIVE
4886 Enable interactive DDR debugging. See doc/README.fsl-ddr.
4888 - CONFIG_FSL_DDR_SYNC_REFRESH
4889 Enable sync of refresh for multiple controllers.
4891 - CONFIG_FSL_DDR_BIST
4892 Enable built-in memory test for Freescale DDR controllers.
4894 - CONFIG_SYS_83XX_DDR_USES_CS0
4895 Only for 83xx systems. If specified, then DDR should
4896 be configured using CS0 and CS1 instead of CS2 and CS3.
4898 - CONFIG_ETHER_ON_FEC[12]
4899 Define to enable FEC[12] on a 8xx series processor.
4901 - CONFIG_FEC[12]_PHY
4902 Define to the hardcoded PHY address which corresponds
4903 to the given FEC; i. e.
4904 #define CONFIG_FEC1_PHY 4
4905 means that the PHY with address 4 is connected to FEC1
4907 When set to -1, means to probe for first available.
4909 - CONFIG_FEC[12]_PHY_NORXERR
4910 The PHY does not have a RXERR line (RMII only).
4911 (so program the FEC to ignore it).
4914 Enable RMII mode for all FECs.
4915 Note that this is a global option, we can't
4916 have one FEC in standard MII mode and another in RMII mode.
4918 - CONFIG_CRC32_VERIFY
4919 Add a verify option to the crc32 command.
4922 => crc32 -v <address> <count> <crc32>
4924 Where address/count indicate a memory area
4925 and crc32 is the correct crc32 which the
4929 Add the "loopw" memory command. This only takes effect if
4930 the memory commands are activated globally (CONFIG_CMD_MEM).
4933 Add the "mdc" and "mwc" memory commands. These are cyclic
4938 This command will print 4 bytes (10,11,12,13) each 500 ms.
4940 => mwc.l 100 12345678 10
4941 This command will write 12345678 to address 100 all 10 ms.
4943 This only takes effect if the memory commands are activated
4944 globally (CONFIG_CMD_MEM).
4946 - CONFIG_SKIP_LOWLEVEL_INIT
4947 [ARM, NDS32, MIPS only] If this variable is defined, then certain
4948 low level initializations (like setting up the memory
4949 controller) are omitted and/or U-Boot does not
4950 relocate itself into RAM.
4952 Normally this variable MUST NOT be defined. The only
4953 exception is when U-Boot is loaded (to RAM) by some
4954 other boot loader or by a debugger which performs
4955 these initializations itself.
4958 Modifies the behaviour of start.S when compiling a loader
4959 that is executed before the actual U-Boot. E.g. when
4960 compiling a NAND SPL.
4963 Modifies the behaviour of start.S when compiling a loader
4964 that is executed after the SPL and before the actual U-Boot.
4965 It is loaded by the SPL.
4967 - CONFIG_SYS_MPC85XX_NO_RESETVEC
4968 Only for 85xx systems. If this variable is specified, the section
4969 .resetvec is not kept and the section .bootpg is placed in the
4970 previous 4k of the .text section.
4972 - CONFIG_ARCH_MAP_SYSMEM
4973 Generally U-Boot (and in particular the md command) uses
4974 effective address. It is therefore not necessary to regard
4975 U-Boot address as virtual addresses that need to be translated
4976 to physical addresses. However, sandbox requires this, since
4977 it maintains its own little RAM buffer which contains all
4978 addressable memory. This option causes some memory accesses
4979 to be mapped through map_sysmem() / unmap_sysmem().
4981 - CONFIG_USE_ARCH_MEMCPY
4982 CONFIG_USE_ARCH_MEMSET
4983 If these options are used a optimized version of memcpy/memset will
4984 be used if available. These functions may be faster under some
4985 conditions but may increase the binary size.
4987 - CONFIG_X86_RESET_VECTOR
4988 If defined, the x86 reset vector code is included. This is not
4989 needed when U-Boot is running from Coreboot.
4992 Defines the MPU clock speed (in MHz).
4994 NOTE : currently only supported on AM335x platforms.
4996 - CONFIG_SPL_AM33XX_ENABLE_RTC32K_OSC:
4997 Enables the RTC32K OSC on AM33xx based plattforms
4999 - CONFIG_SYS_NAND_NO_SUBPAGE_WRITE
5000 Option to disable subpage write in NAND driver
5001 driver that uses this:
5002 drivers/mtd/nand/davinci_nand.c
5004 Freescale QE/FMAN Firmware Support:
5005 -----------------------------------
5007 The Freescale QUICCEngine (QE) and Frame Manager (FMAN) both support the
5008 loading of "firmware", which is encoded in the QE firmware binary format.
5009 This firmware often needs to be loaded during U-Boot booting, so macros
5010 are used to identify the storage device (NOR flash, SPI, etc) and the address
5013 - CONFIG_SYS_FMAN_FW_ADDR
5014 The address in the storage device where the FMAN microcode is located. The
5015 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
5018 - CONFIG_SYS_QE_FW_ADDR
5019 The address in the storage device where the QE microcode is located. The
5020 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
5023 - CONFIG_SYS_QE_FMAN_FW_LENGTH
5024 The maximum possible size of the firmware. The firmware binary format
5025 has a field that specifies the actual size of the firmware, but it
5026 might not be possible to read any part of the firmware unless some
5027 local storage is allocated to hold the entire firmware first.
5029 - CONFIG_SYS_QE_FMAN_FW_IN_NOR
5030 Specifies that QE/FMAN firmware is located in NOR flash, mapped as
5031 normal addressable memory via the LBC. CONFIG_SYS_FMAN_FW_ADDR is the
5032 virtual address in NOR flash.
5034 - CONFIG_SYS_QE_FMAN_FW_IN_NAND
5035 Specifies that QE/FMAN firmware is located in NAND flash.
5036 CONFIG_SYS_FMAN_FW_ADDR is the offset within NAND flash.
5038 - CONFIG_SYS_QE_FMAN_FW_IN_MMC
5039 Specifies that QE/FMAN firmware is located on the primary SD/MMC
5040 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
5042 - CONFIG_SYS_QE_FMAN_FW_IN_SPIFLASH
5043 Specifies that QE/FMAN firmware is located on the primary SPI
5044 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
5046 - CONFIG_SYS_QE_FMAN_FW_IN_REMOTE
5047 Specifies that QE/FMAN firmware is located in the remote (master)
5048 memory space. CONFIG_SYS_FMAN_FW_ADDR is a virtual address which
5049 can be mapped from slave TLB->slave LAW->slave SRIO or PCIE outbound
5050 window->master inbound window->master LAW->the ucode address in
5051 master's memory space.
5053 Freescale Layerscape Management Complex Firmware Support:
5054 ---------------------------------------------------------
5055 The Freescale Layerscape Management Complex (MC) supports the loading of
5057 This firmware often needs to be loaded during U-Boot booting, so macros
5058 are used to identify the storage device (NOR flash, SPI, etc) and the address
5061 - CONFIG_FSL_MC_ENET
5062 Enable the MC driver for Layerscape SoCs.
5064 - CONFIG_SYS_LS_MC_FW_ADDR
5065 The address in the storage device where the firmware is located. The
5066 meaning of this address depends on which CONFIG_SYS_LS_MC_FW_IN_xxx macro
5069 - CONFIG_SYS_LS_MC_FW_LENGTH
5070 The maximum possible size of the firmware. The firmware binary format
5071 has a field that specifies the actual size of the firmware, but it
5072 might not be possible to read any part of the firmware unless some
5073 local storage is allocated to hold the entire firmware first.
5075 - CONFIG_SYS_LS_MC_FW_IN_NOR
5076 Specifies that MC firmware is located in NOR flash, mapped as
5077 normal addressable memory via the LBC. CONFIG_SYS_LS_MC_FW_ADDR is the
5078 virtual address in NOR flash.
5080 Building the Software:
5081 ======================
5083 Building U-Boot has been tested in several native build environments
5084 and in many different cross environments. Of course we cannot support
5085 all possibly existing versions of cross development tools in all
5086 (potentially obsolete) versions. In case of tool chain problems we
5087 recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK)
5088 which is extensively used to build and test U-Boot.
5090 If you are not using a native environment, it is assumed that you
5091 have GNU cross compiling tools available in your path. In this case,
5092 you must set the environment variable CROSS_COMPILE in your shell.
5093 Note that no changes to the Makefile or any other source files are
5094 necessary. For example using the ELDK on a 4xx CPU, please enter:
5096 $ CROSS_COMPILE=ppc_4xx-
5097 $ export CROSS_COMPILE
5099 Note: If you wish to generate Windows versions of the utilities in
5100 the tools directory you can use the MinGW toolchain
5101 (http://www.mingw.org). Set your HOST tools to the MinGW
5102 toolchain and execute 'make tools'. For example:
5104 $ make HOSTCC=i586-mingw32msvc-gcc HOSTSTRIP=i586-mingw32msvc-strip tools
5106 Binaries such as tools/mkimage.exe will be created which can
5107 be executed on computers running Windows.
5109 U-Boot is intended to be simple to build. After installing the
5110 sources you must configure U-Boot for one specific board type. This
5115 where "NAME_defconfig" is the name of one of the existing configu-
5116 rations; see boards.cfg for supported names.
5118 Note: for some board special configuration names may exist; check if
5119 additional information is available from the board vendor; for
5120 instance, the TQM823L systems are available without (standard)
5121 or with LCD support. You can select such additional "features"
5122 when choosing the configuration, i. e.
5124 make TQM823L_defconfig
5125 - will configure for a plain TQM823L, i. e. no LCD support
5127 make TQM823L_LCD_defconfig
5128 - will configure for a TQM823L with U-Boot console on LCD
5133 Finally, type "make all", and you should get some working U-Boot
5134 images ready for download to / installation on your system:
5136 - "u-boot.bin" is a raw binary image
5137 - "u-boot" is an image in ELF binary format
5138 - "u-boot.srec" is in Motorola S-Record format
5140 By default the build is performed locally and the objects are saved
5141 in the source directory. One of the two methods can be used to change
5142 this behavior and build U-Boot to some external directory:
5144 1. Add O= to the make command line invocations:
5146 make O=/tmp/build distclean
5147 make O=/tmp/build NAME_defconfig
5148 make O=/tmp/build all
5150 2. Set environment variable KBUILD_OUTPUT to point to the desired location:
5152 export KBUILD_OUTPUT=/tmp/build
5157 Note that the command line "O=" setting overrides the KBUILD_OUTPUT environment
5161 Please be aware that the Makefiles assume you are using GNU make, so
5162 for instance on NetBSD you might need to use "gmake" instead of
5166 If the system board that you have is not listed, then you will need
5167 to port U-Boot to your hardware platform. To do this, follow these
5170 1. Add a new configuration option for your board to the toplevel
5171 "boards.cfg" file, using the existing entries as examples.
5172 Follow the instructions there to keep the boards in order.
5173 2. Create a new directory to hold your board specific code. Add any
5174 files you need. In your board directory, you will need at least
5175 the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds".
5176 3. Create a new configuration file "include/configs/<board>.h" for
5178 3. If you're porting U-Boot to a new CPU, then also create a new
5179 directory to hold your CPU specific code. Add any files you need.
5180 4. Run "make <board>_defconfig" with your new name.
5181 5. Type "make", and you should get a working "u-boot.srec" file
5182 to be installed on your target system.
5183 6. Debug and solve any problems that might arise.
5184 [Of course, this last step is much harder than it sounds.]
5187 Testing of U-Boot Modifications, Ports to New Hardware, etc.:
5188 ==============================================================
5190 If you have modified U-Boot sources (for instance added a new board
5191 or support for new devices, a new CPU, etc.) you are expected to
5192 provide feedback to the other developers. The feedback normally takes
5193 the form of a "patch", i. e. a context diff against a certain (latest
5194 official or latest in the git repository) version of U-Boot sources.
5196 But before you submit such a patch, please verify that your modifi-
5197 cation did not break existing code. At least make sure that *ALL* of
5198 the supported boards compile WITHOUT ANY compiler warnings. To do so,
5199 just run the "MAKEALL" script, which will configure and build U-Boot
5200 for ALL supported system. Be warned, this will take a while. You can
5201 select which (cross) compiler to use by passing a `CROSS_COMPILE'
5202 environment variable to the script, i. e. to use the ELDK cross tools
5205 CROSS_COMPILE=ppc_8xx- MAKEALL
5207 or to build on a native PowerPC system you can type
5209 CROSS_COMPILE=' ' MAKEALL
5211 When using the MAKEALL script, the default behaviour is to build
5212 U-Boot in the source directory. This location can be changed by
5213 setting the BUILD_DIR environment variable. Also, for each target
5214 built, the MAKEALL script saves two log files (<target>.ERR and
5215 <target>.MAKEALL) in the <source dir>/LOG directory. This default
5216 location can be changed by setting the MAKEALL_LOGDIR environment
5217 variable. For example:
5219 export BUILD_DIR=/tmp/build
5220 export MAKEALL_LOGDIR=/tmp/log
5221 CROSS_COMPILE=ppc_8xx- MAKEALL
5223 With the above settings build objects are saved in the /tmp/build,
5224 log files are saved in the /tmp/log and the source tree remains clean
5225 during the whole build process.
5228 See also "U-Boot Porting Guide" below.
5231 Monitor Commands - Overview:
5232 ============================
5234 go - start application at address 'addr'
5235 run - run commands in an environment variable
5236 bootm - boot application image from memory
5237 bootp - boot image via network using BootP/TFTP protocol
5238 bootz - boot zImage from memory
5239 tftpboot- boot image via network using TFTP protocol
5240 and env variables "ipaddr" and "serverip"
5241 (and eventually "gatewayip")
5242 tftpput - upload a file via network using TFTP protocol
5243 rarpboot- boot image via network using RARP/TFTP protocol
5244 diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
5245 loads - load S-Record file over serial line
5246 loadb - load binary file over serial line (kermit mode)
5248 mm - memory modify (auto-incrementing)
5249 nm - memory modify (constant address)
5250 mw - memory write (fill)
5252 cmp - memory compare
5253 crc32 - checksum calculation
5254 i2c - I2C sub-system
5255 sspi - SPI utility commands
5256 base - print or set address offset
5257 printenv- print environment variables
5258 setenv - set environment variables
5259 saveenv - save environment variables to persistent storage
5260 protect - enable or disable FLASH write protection
5261 erase - erase FLASH memory
5262 flinfo - print FLASH memory information
5263 nand - NAND memory operations (see doc/README.nand)
5264 bdinfo - print Board Info structure
5265 iminfo - print header information for application image
5266 coninfo - print console devices and informations
5267 ide - IDE sub-system
5268 loop - infinite loop on address range
5269 loopw - infinite write loop on address range
5270 mtest - simple RAM test
5271 icache - enable or disable instruction cache
5272 dcache - enable or disable data cache
5273 reset - Perform RESET of the CPU
5274 echo - echo args to console
5275 version - print monitor version
5276 help - print online help
5277 ? - alias for 'help'
5280 Monitor Commands - Detailed Description:
5281 ========================================
5285 For now: just type "help <command>".
5288 Environment Variables:
5289 ======================
5291 U-Boot supports user configuration using Environment Variables which
5292 can be made persistent by saving to Flash memory.
5294 Environment Variables are set using "setenv", printed using
5295 "printenv", and saved to Flash using "saveenv". Using "setenv"
5296 without a value can be used to delete a variable from the
5297 environment. As long as you don't save the environment you are
5298 working with an in-memory copy. In case the Flash area containing the
5299 environment is erased by accident, a default environment is provided.
5301 Some configuration options can be set using Environment Variables.
5303 List of environment variables (most likely not complete):
5305 baudrate - see CONFIG_BAUDRATE
5307 bootdelay - see CONFIG_BOOTDELAY
5309 bootcmd - see CONFIG_BOOTCOMMAND
5311 bootargs - Boot arguments when booting an RTOS image
5313 bootfile - Name of the image to load with TFTP
5315 bootm_low - Memory range available for image processing in the bootm
5316 command can be restricted. This variable is given as
5317 a hexadecimal number and defines lowest address allowed
5318 for use by the bootm command. See also "bootm_size"
5319 environment variable. Address defined by "bootm_low" is
5320 also the base of the initial memory mapping for the Linux
5321 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ and
5324 bootm_mapsize - Size of the initial memory mapping for the Linux kernel.
5325 This variable is given as a hexadecimal number and it
5326 defines the size of the memory region starting at base
5327 address bootm_low that is accessible by the Linux kernel
5328 during early boot. If unset, CONFIG_SYS_BOOTMAPSZ is used
5329 as the default value if it is defined, and bootm_size is
5332 bootm_size - Memory range available for image processing in the bootm
5333 command can be restricted. This variable is given as
5334 a hexadecimal number and defines the size of the region
5335 allowed for use by the bootm command. See also "bootm_low"
5336 environment variable.
5338 updatefile - Location of the software update file on a TFTP server, used
5339 by the automatic software update feature. Please refer to
5340 documentation in doc/README.update for more details.
5342 autoload - if set to "no" (any string beginning with 'n'),
5343 "bootp" will just load perform a lookup of the
5344 configuration from the BOOTP server, but not try to
5345 load any image using TFTP
5347 autostart - if set to "yes", an image loaded using the "bootp",
5348 "rarpboot", "tftpboot" or "diskboot" commands will
5349 be automatically started (by internally calling
5352 If set to "no", a standalone image passed to the
5353 "bootm" command will be copied to the load address
5354 (and eventually uncompressed), but NOT be started.
5355 This can be used to load and uncompress arbitrary
5358 fdt_high - if set this restricts the maximum address that the
5359 flattened device tree will be copied into upon boot.
5360 For example, if you have a system with 1 GB memory
5361 at physical address 0x10000000, while Linux kernel
5362 only recognizes the first 704 MB as low memory, you
5363 may need to set fdt_high as 0x3C000000 to have the
5364 device tree blob be copied to the maximum address
5365 of the 704 MB low memory, so that Linux kernel can
5366 access it during the boot procedure.
5368 If this is set to the special value 0xFFFFFFFF then
5369 the fdt will not be copied at all on boot. For this
5370 to work it must reside in writable memory, have
5371 sufficient padding on the end of it for u-boot to
5372 add the information it needs into it, and the memory
5373 must be accessible by the kernel.
5375 fdtcontroladdr- if set this is the address of the control flattened
5376 device tree used by U-Boot when CONFIG_OF_CONTROL is
5379 i2cfast - (PPC405GP|PPC405EP only)
5380 if set to 'y' configures Linux I2C driver for fast
5381 mode (400kHZ). This environment variable is used in
5382 initialization code. So, for changes to be effective
5383 it must be saved and board must be reset.
5385 initrd_high - restrict positioning of initrd images:
5386 If this variable is not set, initrd images will be
5387 copied to the highest possible address in RAM; this
5388 is usually what you want since it allows for
5389 maximum initrd size. If for some reason you want to
5390 make sure that the initrd image is loaded below the
5391 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment
5392 variable to a value of "no" or "off" or "0".
5393 Alternatively, you can set it to a maximum upper
5394 address to use (U-Boot will still check that it
5395 does not overwrite the U-Boot stack and data).
5397 For instance, when you have a system with 16 MB
5398 RAM, and want to reserve 4 MB from use by Linux,
5399 you can do this by adding "mem=12M" to the value of
5400 the "bootargs" variable. However, now you must make
5401 sure that the initrd image is placed in the first
5402 12 MB as well - this can be done with
5404 setenv initrd_high 00c00000
5406 If you set initrd_high to 0xFFFFFFFF, this is an
5407 indication to U-Boot that all addresses are legal
5408 for the Linux kernel, including addresses in flash
5409 memory. In this case U-Boot will NOT COPY the
5410 ramdisk at all. This may be useful to reduce the
5411 boot time on your system, but requires that this
5412 feature is supported by your Linux kernel.
5414 ipaddr - IP address; needed for tftpboot command
5416 loadaddr - Default load address for commands like "bootp",
5417 "rarpboot", "tftpboot", "loadb" or "diskboot"
5419 loads_echo - see CONFIG_LOADS_ECHO
5421 serverip - TFTP server IP address; needed for tftpboot command
5423 bootretry - see CONFIG_BOOT_RETRY_TIME
5425 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
5427 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
5429 ethprime - controls which interface is used first.
5431 ethact - controls which interface is currently active.
5432 For example you can do the following
5434 => setenv ethact FEC
5435 => ping 192.168.0.1 # traffic sent on FEC
5436 => setenv ethact SCC
5437 => ping 10.0.0.1 # traffic sent on SCC
5439 ethrotate - When set to "no" U-Boot does not go through all
5440 available network interfaces.
5441 It just stays at the currently selected interface.
5443 netretry - When set to "no" each network operation will
5444 either succeed or fail without retrying.
5445 When set to "once" the network operation will
5446 fail when all the available network interfaces
5447 are tried once without success.
5448 Useful on scripts which control the retry operation
5451 npe_ucode - set load address for the NPE microcode
5453 silent_linux - If set then Linux will be told to boot silently, by
5454 changing the console to be empty. If "yes" it will be
5455 made silent. If "no" it will not be made silent. If
5456 unset, then it will be made silent if the U-Boot console
5459 tftpsrcport - If this is set, the value is used for TFTP's
5462 tftpdstport - If this is set, the value is used for TFTP's UDP
5463 destination port instead of the Well Know Port 69.
5465 tftpblocksize - Block size to use for TFTP transfers; if not set,
5466 we use the TFTP server's default block size
5468 tftptimeout - Retransmission timeout for TFTP packets (in milli-
5469 seconds, minimum value is 1000 = 1 second). Defines
5470 when a packet is considered to be lost so it has to
5471 be retransmitted. The default is 5000 = 5 seconds.
5472 Lowering this value may make downloads succeed
5473 faster in networks with high packet loss rates or
5474 with unreliable TFTP servers.
5476 vlan - When set to a value < 4095 the traffic over
5477 Ethernet is encapsulated/received over 802.1q
5480 The following image location variables contain the location of images
5481 used in booting. The "Image" column gives the role of the image and is
5482 not an environment variable name. The other columns are environment
5483 variable names. "File Name" gives the name of the file on a TFTP
5484 server, "RAM Address" gives the location in RAM the image will be
5485 loaded to, and "Flash Location" gives the image's address in NOR
5486 flash or offset in NAND flash.
5488 *Note* - these variables don't have to be defined for all boards, some
5489 boards currently use other variables for these purposes, and some
5490 boards use these variables for other purposes.
5492 Image File Name RAM Address Flash Location
5493 ----- --------- ----------- --------------
5494 u-boot u-boot u-boot_addr_r u-boot_addr
5495 Linux kernel bootfile kernel_addr_r kernel_addr
5496 device tree blob fdtfile fdt_addr_r fdt_addr
5497 ramdisk ramdiskfile ramdisk_addr_r ramdisk_addr
5499 The following environment variables may be used and automatically
5500 updated by the network boot commands ("bootp" and "rarpboot"),
5501 depending the information provided by your boot server:
5503 bootfile - see above
5504 dnsip - IP address of your Domain Name Server
5505 dnsip2 - IP address of your secondary Domain Name Server
5506 gatewayip - IP address of the Gateway (Router) to use
5507 hostname - Target hostname
5509 netmask - Subnet Mask
5510 rootpath - Pathname of the root filesystem on the NFS server
5511 serverip - see above
5514 There are two special Environment Variables:
5516 serial# - contains hardware identification information such
5517 as type string and/or serial number
5518 ethaddr - Ethernet address
5520 These variables can be set only once (usually during manufacturing of
5521 the board). U-Boot refuses to delete or overwrite these variables
5522 once they have been set once.
5525 Further special Environment Variables:
5527 ver - Contains the U-Boot version string as printed
5528 with the "version" command. This variable is
5529 readonly (see CONFIG_VERSION_VARIABLE).
5532 Please note that changes to some configuration parameters may take
5533 only effect after the next boot (yes, that's just like Windoze :-).
5536 Callback functions for environment variables:
5537 ---------------------------------------------
5539 For some environment variables, the behavior of u-boot needs to change
5540 when their values are changed. This functionality allows functions to
5541 be associated with arbitrary variables. On creation, overwrite, or
5542 deletion, the callback will provide the opportunity for some side
5543 effect to happen or for the change to be rejected.
5545 The callbacks are named and associated with a function using the
5546 U_BOOT_ENV_CALLBACK macro in your board or driver code.
5548 These callbacks are associated with variables in one of two ways. The
5549 static list can be added to by defining CONFIG_ENV_CALLBACK_LIST_STATIC
5550 in the board configuration to a string that defines a list of
5551 associations. The list must be in the following format:
5553 entry = variable_name[:callback_name]
5556 If the callback name is not specified, then the callback is deleted.
5557 Spaces are also allowed anywhere in the list.
5559 Callbacks can also be associated by defining the ".callbacks" variable
5560 with the same list format above. Any association in ".callbacks" will
5561 override any association in the static list. You can define
5562 CONFIG_ENV_CALLBACK_LIST_DEFAULT to a list (string) to define the
5563 ".callbacks" environment variable in the default or embedded environment.
5565 If CONFIG_REGEX is defined, the variable_name above is evaluated as a
5566 regular expression. This allows multiple variables to be connected to
5567 the same callback without explicitly listing them all out.
5570 Command Line Parsing:
5571 =====================
5573 There are two different command line parsers available with U-Boot:
5574 the old "simple" one, and the much more powerful "hush" shell:
5576 Old, simple command line parser:
5577 --------------------------------
5579 - supports environment variables (through setenv / saveenv commands)
5580 - several commands on one line, separated by ';'
5581 - variable substitution using "... ${name} ..." syntax
5582 - special characters ('$', ';') can be escaped by prefixing with '\',
5584 setenv bootcmd bootm \${address}
5585 - You can also escape text by enclosing in single apostrophes, for example:
5586 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
5591 - similar to Bourne shell, with control structures like
5592 if...then...else...fi, for...do...done; while...do...done,
5593 until...do...done, ...
5594 - supports environment ("global") variables (through setenv / saveenv
5595 commands) and local shell variables (through standard shell syntax
5596 "name=value"); only environment variables can be used with "run"
5602 (1) If a command line (or an environment variable executed by a "run"
5603 command) contains several commands separated by semicolon, and
5604 one of these commands fails, then the remaining commands will be
5607 (2) If you execute several variables with one call to run (i. e.
5608 calling run with a list of variables as arguments), any failing
5609 command will cause "run" to terminate, i. e. the remaining
5610 variables are not executed.
5612 Note for Redundant Ethernet Interfaces:
5613 =======================================
5615 Some boards come with redundant Ethernet interfaces; U-Boot supports
5616 such configurations and is capable of automatic selection of a
5617 "working" interface when needed. MAC assignment works as follows:
5619 Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
5620 MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
5621 "eth1addr" (=>eth1), "eth2addr", ...
5623 If the network interface stores some valid MAC address (for instance
5624 in SROM), this is used as default address if there is NO correspon-
5625 ding setting in the environment; if the corresponding environment
5626 variable is set, this overrides the settings in the card; that means:
5628 o If the SROM has a valid MAC address, and there is no address in the
5629 environment, the SROM's address is used.
5631 o If there is no valid address in the SROM, and a definition in the
5632 environment exists, then the value from the environment variable is
5635 o If both the SROM and the environment contain a MAC address, and
5636 both addresses are the same, this MAC address is used.
5638 o If both the SROM and the environment contain a MAC address, and the
5639 addresses differ, the value from the environment is used and a
5642 o If neither SROM nor the environment contain a MAC address, an error
5643 is raised. If CONFIG_NET_RANDOM_ETHADDR is defined, then in this case
5644 a random, locally-assigned MAC is used.
5646 If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses
5647 will be programmed into hardware as part of the initialization process. This
5648 may be skipped by setting the appropriate 'ethmacskip' environment variable.
5649 The naming convention is as follows:
5650 "ethmacskip" (=>eth0), "eth1macskip" (=>eth1) etc.
5655 U-Boot is capable of booting (and performing other auxiliary operations on)
5656 images in two formats:
5658 New uImage format (FIT)
5659 -----------------------
5661 Flexible and powerful format based on Flattened Image Tree -- FIT (similar
5662 to Flattened Device Tree). It allows the use of images with multiple
5663 components (several kernels, ramdisks, etc.), with contents protected by
5664 SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory.
5670 Old image format is based on binary files which can be basically anything,
5671 preceded by a special header; see the definitions in include/image.h for
5672 details; basically, the header defines the following image properties:
5674 * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
5675 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
5676 LynxOS, pSOS, QNX, RTEMS, INTEGRITY;
5677 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS,
5679 * Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86,
5680 IA64, MIPS, NDS32, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
5681 Currently supported: ARM, AVR32, Intel x86, MIPS, NDS32, Nios II, PowerPC).
5682 * Compression Type (uncompressed, gzip, bzip2)
5688 The header is marked by a special Magic Number, and both the header
5689 and the data portions of the image are secured against corruption by
5696 Although U-Boot should support any OS or standalone application
5697 easily, the main focus has always been on Linux during the design of
5700 U-Boot includes many features that so far have been part of some
5701 special "boot loader" code within the Linux kernel. Also, any
5702 "initrd" images to be used are no longer part of one big Linux image;
5703 instead, kernel and "initrd" are separate images. This implementation
5704 serves several purposes:
5706 - the same features can be used for other OS or standalone
5707 applications (for instance: using compressed images to reduce the
5708 Flash memory footprint)
5710 - it becomes much easier to port new Linux kernel versions because
5711 lots of low-level, hardware dependent stuff are done by U-Boot
5713 - the same Linux kernel image can now be used with different "initrd"
5714 images; of course this also means that different kernel images can
5715 be run with the same "initrd". This makes testing easier (you don't
5716 have to build a new "zImage.initrd" Linux image when you just
5717 change a file in your "initrd"). Also, a field-upgrade of the
5718 software is easier now.
5724 Porting Linux to U-Boot based systems:
5725 ---------------------------------------
5727 U-Boot cannot save you from doing all the necessary modifications to
5728 configure the Linux device drivers for use with your target hardware
5729 (no, we don't intend to provide a full virtual machine interface to
5732 But now you can ignore ALL boot loader code (in arch/powerpc/mbxboot).
5734 Just make sure your machine specific header file (for instance
5735 include/asm-ppc/tqm8xx.h) includes the same definition of the Board
5736 Information structure as we define in include/asm-<arch>/u-boot.h,
5737 and make sure that your definition of IMAP_ADDR uses the same value
5738 as your U-Boot configuration in CONFIG_SYS_IMMR.
5740 Note that U-Boot now has a driver model, a unified model for drivers.
5741 If you are adding a new driver, plumb it into driver model. If there
5742 is no uclass available, you are encouraged to create one. See
5746 Configuring the Linux kernel:
5747 -----------------------------
5749 No specific requirements for U-Boot. Make sure you have some root
5750 device (initial ramdisk, NFS) for your target system.
5753 Building a Linux Image:
5754 -----------------------
5756 With U-Boot, "normal" build targets like "zImage" or "bzImage" are
5757 not used. If you use recent kernel source, a new build target
5758 "uImage" will exist which automatically builds an image usable by
5759 U-Boot. Most older kernels also have support for a "pImage" target,
5760 which was introduced for our predecessor project PPCBoot and uses a
5761 100% compatible format.
5765 make TQM850L_defconfig
5770 The "uImage" build target uses a special tool (in 'tools/mkimage') to
5771 encapsulate a compressed Linux kernel image with header information,
5772 CRC32 checksum etc. for use with U-Boot. This is what we are doing:
5774 * build a standard "vmlinux" kernel image (in ELF binary format):
5776 * convert the kernel into a raw binary image:
5778 ${CROSS_COMPILE}-objcopy -O binary \
5779 -R .note -R .comment \
5780 -S vmlinux linux.bin
5782 * compress the binary image:
5786 * package compressed binary image for U-Boot:
5788 mkimage -A ppc -O linux -T kernel -C gzip \
5789 -a 0 -e 0 -n "Linux Kernel Image" \
5790 -d linux.bin.gz uImage
5793 The "mkimage" tool can also be used to create ramdisk images for use
5794 with U-Boot, either separated from the Linux kernel image, or
5795 combined into one file. "mkimage" encapsulates the images with a 64
5796 byte header containing information about target architecture,
5797 operating system, image type, compression method, entry points, time
5798 stamp, CRC32 checksums, etc.
5800 "mkimage" can be called in two ways: to verify existing images and
5801 print the header information, or to build new images.
5803 In the first form (with "-l" option) mkimage lists the information
5804 contained in the header of an existing U-Boot image; this includes
5805 checksum verification:
5807 tools/mkimage -l image
5808 -l ==> list image header information
5810 The second form (with "-d" option) is used to build a U-Boot image
5811 from a "data file" which is used as image payload:
5813 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
5814 -n name -d data_file image
5815 -A ==> set architecture to 'arch'
5816 -O ==> set operating system to 'os'
5817 -T ==> set image type to 'type'
5818 -C ==> set compression type 'comp'
5819 -a ==> set load address to 'addr' (hex)
5820 -e ==> set entry point to 'ep' (hex)
5821 -n ==> set image name to 'name'
5822 -d ==> use image data from 'datafile'
5824 Right now, all Linux kernels for PowerPC systems use the same load
5825 address (0x00000000), but the entry point address depends on the
5828 - 2.2.x kernels have the entry point at 0x0000000C,
5829 - 2.3.x and later kernels have the entry point at 0x00000000.
5831 So a typical call to build a U-Boot image would read:
5833 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
5834 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
5835 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz \
5836 > examples/uImage.TQM850L
5837 Image Name: 2.4.4 kernel for TQM850L
5838 Created: Wed Jul 19 02:34:59 2000
5839 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5840 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
5841 Load Address: 0x00000000
5842 Entry Point: 0x00000000
5844 To verify the contents of the image (or check for corruption):
5846 -> tools/mkimage -l examples/uImage.TQM850L
5847 Image Name: 2.4.4 kernel for TQM850L
5848 Created: Wed Jul 19 02:34:59 2000
5849 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5850 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
5851 Load Address: 0x00000000
5852 Entry Point: 0x00000000
5854 NOTE: for embedded systems where boot time is critical you can trade
5855 speed for memory and install an UNCOMPRESSED image instead: this
5856 needs more space in Flash, but boots much faster since it does not
5857 need to be uncompressed:
5859 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz
5860 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
5861 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
5862 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux \
5863 > examples/uImage.TQM850L-uncompressed
5864 Image Name: 2.4.4 kernel for TQM850L
5865 Created: Wed Jul 19 02:34:59 2000
5866 Image Type: PowerPC Linux Kernel Image (uncompressed)
5867 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
5868 Load Address: 0x00000000
5869 Entry Point: 0x00000000
5872 Similar you can build U-Boot images from a 'ramdisk.image.gz' file
5873 when your kernel is intended to use an initial ramdisk:
5875 -> tools/mkimage -n 'Simple Ramdisk Image' \
5876 > -A ppc -O linux -T ramdisk -C gzip \
5877 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
5878 Image Name: Simple Ramdisk Image
5879 Created: Wed Jan 12 14:01:50 2000
5880 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5881 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
5882 Load Address: 0x00000000
5883 Entry Point: 0x00000000
5885 The "dumpimage" is a tool to disassemble images built by mkimage. Its "-i"
5886 option performs the converse operation of the mkimage's second form (the "-d"
5887 option). Given an image built by mkimage, the dumpimage extracts a "data file"
5890 tools/dumpimage -i image -T type -p position data_file
5891 -i ==> extract from the 'image' a specific 'data_file'
5892 -T ==> set image type to 'type'
5893 -p ==> 'position' (starting at 0) of the 'data_file' inside the 'image'
5896 Installing a Linux Image:
5897 -------------------------
5899 To downloading a U-Boot image over the serial (console) interface,
5900 you must convert the image to S-Record format:
5902 objcopy -I binary -O srec examples/image examples/image.srec
5904 The 'objcopy' does not understand the information in the U-Boot
5905 image header, so the resulting S-Record file will be relative to
5906 address 0x00000000. To load it to a given address, you need to
5907 specify the target address as 'offset' parameter with the 'loads'
5910 Example: install the image to address 0x40100000 (which on the
5911 TQM8xxL is in the first Flash bank):
5913 => erase 40100000 401FFFFF
5919 ## Ready for S-Record download ...
5920 ~>examples/image.srec
5921 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
5923 15989 15990 15991 15992
5924 [file transfer complete]
5926 ## Start Addr = 0x00000000
5929 You can check the success of the download using the 'iminfo' command;
5930 this includes a checksum verification so you can be sure no data
5931 corruption happened:
5935 ## Checking Image at 40100000 ...
5936 Image Name: 2.2.13 for initrd on TQM850L
5937 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5938 Data Size: 335725 Bytes = 327 kB = 0 MB
5939 Load Address: 00000000
5940 Entry Point: 0000000c
5941 Verifying Checksum ... OK
5947 The "bootm" command is used to boot an application that is stored in
5948 memory (RAM or Flash). In case of a Linux kernel image, the contents
5949 of the "bootargs" environment variable is passed to the kernel as
5950 parameters. You can check and modify this variable using the
5951 "printenv" and "setenv" commands:
5954 => printenv bootargs
5955 bootargs=root=/dev/ram
5957 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5959 => printenv bootargs
5960 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5963 ## Booting Linux kernel at 40020000 ...
5964 Image Name: 2.2.13 for NFS on TQM850L
5965 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5966 Data Size: 381681 Bytes = 372 kB = 0 MB
5967 Load Address: 00000000
5968 Entry Point: 0000000c
5969 Verifying Checksum ... OK
5970 Uncompressing Kernel Image ... OK
5971 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
5972 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5973 time_init: decrementer frequency = 187500000/60
5974 Calibrating delay loop... 49.77 BogoMIPS
5975 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
5978 If you want to boot a Linux kernel with initial RAM disk, you pass
5979 the memory addresses of both the kernel and the initrd image (PPBCOOT
5980 format!) to the "bootm" command:
5982 => imi 40100000 40200000
5984 ## Checking Image at 40100000 ...
5985 Image Name: 2.2.13 for initrd on TQM850L
5986 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5987 Data Size: 335725 Bytes = 327 kB = 0 MB
5988 Load Address: 00000000
5989 Entry Point: 0000000c
5990 Verifying Checksum ... OK
5992 ## Checking Image at 40200000 ...
5993 Image Name: Simple Ramdisk Image
5994 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5995 Data Size: 566530 Bytes = 553 kB = 0 MB
5996 Load Address: 00000000
5997 Entry Point: 00000000
5998 Verifying Checksum ... OK
6000 => bootm 40100000 40200000
6001 ## Booting Linux kernel at 40100000 ...
6002 Image Name: 2.2.13 for initrd on TQM850L
6003 Image Type: PowerPC Linux Kernel Image (gzip compressed)
6004 Data Size: 335725 Bytes = 327 kB = 0 MB
6005 Load Address: 00000000
6006 Entry Point: 0000000c
6007 Verifying Checksum ... OK
6008 Uncompressing Kernel Image ... OK
6009 ## Loading RAMDisk Image at 40200000 ...
6010 Image Name: Simple Ramdisk Image
6011 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
6012 Data Size: 566530 Bytes = 553 kB = 0 MB
6013 Load Address: 00000000
6014 Entry Point: 00000000
6015 Verifying Checksum ... OK
6016 Loading Ramdisk ... OK
6017 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
6018 Boot arguments: root=/dev/ram
6019 time_init: decrementer frequency = 187500000/60
6020 Calibrating delay loop... 49.77 BogoMIPS
6022 RAMDISK: Compressed image found at block 0
6023 VFS: Mounted root (ext2 filesystem).
6027 Boot Linux and pass a flat device tree:
6030 First, U-Boot must be compiled with the appropriate defines. See the section
6031 titled "Linux Kernel Interface" above for a more in depth explanation. The
6032 following is an example of how to start a kernel and pass an updated
6038 oft=oftrees/mpc8540ads.dtb
6039 => tftp $oftaddr $oft
6040 Speed: 1000, full duplex
6042 TFTP from server 192.168.1.1; our IP address is 192.168.1.101
6043 Filename 'oftrees/mpc8540ads.dtb'.
6044 Load address: 0x300000
6047 Bytes transferred = 4106 (100a hex)
6048 => tftp $loadaddr $bootfile
6049 Speed: 1000, full duplex
6051 TFTP from server 192.168.1.1; our IP address is 192.168.1.2
6053 Load address: 0x200000
6054 Loading:############
6056 Bytes transferred = 1029407 (fb51f hex)
6061 => bootm $loadaddr - $oftaddr
6062 ## Booting image at 00200000 ...
6063 Image Name: Linux-2.6.17-dirty
6064 Image Type: PowerPC Linux Kernel Image (gzip compressed)
6065 Data Size: 1029343 Bytes = 1005.2 kB
6066 Load Address: 00000000
6067 Entry Point: 00000000
6068 Verifying Checksum ... OK
6069 Uncompressing Kernel Image ... OK
6070 Booting using flat device tree at 0x300000
6071 Using MPC85xx ADS machine description
6072 Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb
6076 More About U-Boot Image Types:
6077 ------------------------------
6079 U-Boot supports the following image types:
6081 "Standalone Programs" are directly runnable in the environment
6082 provided by U-Boot; it is expected that (if they behave
6083 well) you can continue to work in U-Boot after return from
6084 the Standalone Program.
6085 "OS Kernel Images" are usually images of some Embedded OS which
6086 will take over control completely. Usually these programs
6087 will install their own set of exception handlers, device
6088 drivers, set up the MMU, etc. - this means, that you cannot
6089 expect to re-enter U-Boot except by resetting the CPU.
6090 "RAMDisk Images" are more or less just data blocks, and their
6091 parameters (address, size) are passed to an OS kernel that is
6093 "Multi-File Images" contain several images, typically an OS
6094 (Linux) kernel image and one or more data images like
6095 RAMDisks. This construct is useful for instance when you want
6096 to boot over the network using BOOTP etc., where the boot
6097 server provides just a single image file, but you want to get
6098 for instance an OS kernel and a RAMDisk image.
6100 "Multi-File Images" start with a list of image sizes, each
6101 image size (in bytes) specified by an "uint32_t" in network
6102 byte order. This list is terminated by an "(uint32_t)0".
6103 Immediately after the terminating 0 follow the images, one by
6104 one, all aligned on "uint32_t" boundaries (size rounded up to
6105 a multiple of 4 bytes).
6107 "Firmware Images" are binary images containing firmware (like
6108 U-Boot or FPGA images) which usually will be programmed to
6111 "Script files" are command sequences that will be executed by
6112 U-Boot's command interpreter; this feature is especially
6113 useful when you configure U-Boot to use a real shell (hush)
6114 as command interpreter.
6116 Booting the Linux zImage:
6117 -------------------------
6119 On some platforms, it's possible to boot Linux zImage. This is done
6120 using the "bootz" command. The syntax of "bootz" command is the same
6121 as the syntax of "bootm" command.
6123 Note, defining the CONFIG_SUPPORT_RAW_INITRD allows user to supply
6124 kernel with raw initrd images. The syntax is slightly different, the
6125 address of the initrd must be augmented by it's size, in the following
6126 format: "<initrd addres>:<initrd size>".
6132 One of the features of U-Boot is that you can dynamically load and
6133 run "standalone" applications, which can use some resources of
6134 U-Boot like console I/O functions or interrupt services.
6136 Two simple examples are included with the sources:
6141 'examples/hello_world.c' contains a small "Hello World" Demo
6142 application; it is automatically compiled when you build U-Boot.
6143 It's configured to run at address 0x00040004, so you can play with it
6147 ## Ready for S-Record download ...
6148 ~>examples/hello_world.srec
6149 1 2 3 4 5 6 7 8 9 10 11 ...
6150 [file transfer complete]
6152 ## Start Addr = 0x00040004
6154 => go 40004 Hello World! This is a test.
6155 ## Starting application at 0x00040004 ...
6166 Hit any key to exit ...
6168 ## Application terminated, rc = 0x0
6170 Another example, which demonstrates how to register a CPM interrupt
6171 handler with the U-Boot code, can be found in 'examples/timer.c'.
6172 Here, a CPM timer is set up to generate an interrupt every second.
6173 The interrupt service routine is trivial, just printing a '.'
6174 character, but this is just a demo program. The application can be
6175 controlled by the following keys:
6177 ? - print current values og the CPM Timer registers
6178 b - enable interrupts and start timer
6179 e - stop timer and disable interrupts
6180 q - quit application
6183 ## Ready for S-Record download ...
6184 ~>examples/timer.srec
6185 1 2 3 4 5 6 7 8 9 10 11 ...
6186 [file transfer complete]
6188 ## Start Addr = 0x00040004
6191 ## Starting application at 0x00040004 ...
6194 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
6197 [q, b, e, ?] Set interval 1000000 us
6200 [q, b, e, ?] ........
6201 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
6204 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
6207 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
6210 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
6212 [q, b, e, ?] ...Stopping timer
6214 [q, b, e, ?] ## Application terminated, rc = 0x0
6220 Over time, many people have reported problems when trying to use the
6221 "minicom" terminal emulation program for serial download. I (wd)
6222 consider minicom to be broken, and recommend not to use it. Under
6223 Unix, I recommend to use C-Kermit for general purpose use (and
6224 especially for kermit binary protocol download ("loadb" command), and
6225 use "cu" for S-Record download ("loads" command). See
6226 http://www.denx.de/wiki/view/DULG/SystemSetup#Section_4.3.
6227 for help with kermit.
6230 Nevertheless, if you absolutely want to use it try adding this
6231 configuration to your "File transfer protocols" section:
6233 Name Program Name U/D FullScr IO-Red. Multi
6234 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
6235 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
6241 Starting at version 0.9.2, U-Boot supports NetBSD both as host
6242 (build U-Boot) and target system (boots NetBSD/mpc8xx).
6244 Building requires a cross environment; it is known to work on
6245 NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
6246 need gmake since the Makefiles are not compatible with BSD make).
6247 Note that the cross-powerpc package does not install include files;
6248 attempting to build U-Boot will fail because <machine/ansi.h> is
6249 missing. This file has to be installed and patched manually:
6251 # cd /usr/pkg/cross/powerpc-netbsd/include
6253 # ln -s powerpc machine
6254 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
6255 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
6257 Native builds *don't* work due to incompatibilities between native
6258 and U-Boot include files.
6260 Booting assumes that (the first part of) the image booted is a
6261 stage-2 loader which in turn loads and then invokes the kernel
6262 proper. Loader sources will eventually appear in the NetBSD source
6263 tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
6264 meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz
6267 Implementation Internals:
6268 =========================
6270 The following is not intended to be a complete description of every
6271 implementation detail. However, it should help to understand the
6272 inner workings of U-Boot and make it easier to port it to custom
6276 Initial Stack, Global Data:
6277 ---------------------------
6279 The implementation of U-Boot is complicated by the fact that U-Boot
6280 starts running out of ROM (flash memory), usually without access to
6281 system RAM (because the memory controller is not initialized yet).
6282 This means that we don't have writable Data or BSS segments, and BSS
6283 is not initialized as zero. To be able to get a C environment working
6284 at all, we have to allocate at least a minimal stack. Implementation
6285 options for this are defined and restricted by the CPU used: Some CPU
6286 models provide on-chip memory (like the IMMR area on MPC8xx and
6287 MPC826x processors), on others (parts of) the data cache can be
6288 locked as (mis-) used as memory, etc.
6290 Chris Hallinan posted a good summary of these issues to the
6291 U-Boot mailing list:
6293 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
6294 From: "Chris Hallinan" <clh@net1plus.com>
6295 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
6298 Correct me if I'm wrong, folks, but the way I understand it
6299 is this: Using DCACHE as initial RAM for Stack, etc, does not
6300 require any physical RAM backing up the cache. The cleverness
6301 is that the cache is being used as a temporary supply of
6302 necessary storage before the SDRAM controller is setup. It's
6303 beyond the scope of this list to explain the details, but you
6304 can see how this works by studying the cache architecture and
6305 operation in the architecture and processor-specific manuals.
6307 OCM is On Chip Memory, which I believe the 405GP has 4K. It
6308 is another option for the system designer to use as an
6309 initial stack/RAM area prior to SDRAM being available. Either
6310 option should work for you. Using CS 4 should be fine if your
6311 board designers haven't used it for something that would
6312 cause you grief during the initial boot! It is frequently not
6315 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere
6316 with your processor/board/system design. The default value
6317 you will find in any recent u-boot distribution in
6318 walnut.h should work for you. I'd set it to a value larger
6319 than your SDRAM module. If you have a 64MB SDRAM module, set
6320 it above 400_0000. Just make sure your board has no resources
6321 that are supposed to respond to that address! That code in
6322 start.S has been around a while and should work as is when
6323 you get the config right.
6328 It is essential to remember this, since it has some impact on the C
6329 code for the initialization procedures:
6331 * Initialized global data (data segment) is read-only. Do not attempt
6334 * Do not use any uninitialized global data (or implicitly initialized
6335 as zero data - BSS segment) at all - this is undefined, initiali-
6336 zation is performed later (when relocating to RAM).
6338 * Stack space is very limited. Avoid big data buffers or things like
6341 Having only the stack as writable memory limits means we cannot use
6342 normal global data to share information between the code. But it
6343 turned out that the implementation of U-Boot can be greatly
6344 simplified by making a global data structure (gd_t) available to all
6345 functions. We could pass a pointer to this data as argument to _all_
6346 functions, but this would bloat the code. Instead we use a feature of
6347 the GCC compiler (Global Register Variables) to share the data: we
6348 place a pointer (gd) to the global data into a register which we
6349 reserve for this purpose.
6351 When choosing a register for such a purpose we are restricted by the
6352 relevant (E)ABI specifications for the current architecture, and by
6353 GCC's implementation.
6355 For PowerPC, the following registers have specific use:
6357 R2: reserved for system use
6358 R3-R4: parameter passing and return values
6359 R5-R10: parameter passing
6360 R13: small data area pointer
6364 (U-Boot also uses R12 as internal GOT pointer. r12
6365 is a volatile register so r12 needs to be reset when
6366 going back and forth between asm and C)
6368 ==> U-Boot will use R2 to hold a pointer to the global data
6370 Note: on PPC, we could use a static initializer (since the
6371 address of the global data structure is known at compile time),
6372 but it turned out that reserving a register results in somewhat
6373 smaller code - although the code savings are not that big (on
6374 average for all boards 752 bytes for the whole U-Boot image,
6375 624 text + 127 data).
6377 On Blackfin, the normal C ABI (except for P3) is followed as documented here:
6378 http://docs.blackfin.uclinux.org/doku.php?id=application_binary_interface
6380 ==> U-Boot will use P3 to hold a pointer to the global data
6382 On ARM, the following registers are used:
6384 R0: function argument word/integer result
6385 R1-R3: function argument word
6386 R9: platform specific
6387 R10: stack limit (used only if stack checking is enabled)
6388 R11: argument (frame) pointer
6389 R12: temporary workspace
6392 R15: program counter
6394 ==> U-Boot will use R9 to hold a pointer to the global data
6396 Note: on ARM, only R_ARM_RELATIVE relocations are supported.
6398 On Nios II, the ABI is documented here:
6399 http://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf
6401 ==> U-Boot will use gp to hold a pointer to the global data
6403 Note: on Nios II, we give "-G0" option to gcc and don't use gp
6404 to access small data sections, so gp is free.
6406 On NDS32, the following registers are used:
6408 R0-R1: argument/return
6410 R15: temporary register for assembler
6411 R16: trampoline register
6412 R28: frame pointer (FP)
6413 R29: global pointer (GP)
6414 R30: link register (LP)
6415 R31: stack pointer (SP)
6416 PC: program counter (PC)
6418 ==> U-Boot will use R10 to hold a pointer to the global data
6420 NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope,
6421 or current versions of GCC may "optimize" the code too much.
6426 U-Boot runs in system state and uses physical addresses, i.e. the
6427 MMU is not used either for address mapping nor for memory protection.
6429 The available memory is mapped to fixed addresses using the memory
6430 controller. In this process, a contiguous block is formed for each
6431 memory type (Flash, SDRAM, SRAM), even when it consists of several
6432 physical memory banks.
6434 U-Boot is installed in the first 128 kB of the first Flash bank (on
6435 TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
6436 booting and sizing and initializing DRAM, the code relocates itself
6437 to the upper end of DRAM. Immediately below the U-Boot code some
6438 memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN
6439 configuration setting]. Below that, a structure with global Board
6440 Info data is placed, followed by the stack (growing downward).
6442 Additionally, some exception handler code is copied to the low 8 kB
6443 of DRAM (0x00000000 ... 0x00001FFF).
6445 So a typical memory configuration with 16 MB of DRAM could look like
6448 0x0000 0000 Exception Vector code
6451 0x0000 2000 Free for Application Use
6457 0x00FB FF20 Monitor Stack (Growing downward)
6458 0x00FB FFAC Board Info Data and permanent copy of global data
6459 0x00FC 0000 Malloc Arena
6462 0x00FE 0000 RAM Copy of Monitor Code
6463 ... eventually: LCD or video framebuffer
6464 ... eventually: pRAM (Protected RAM - unchanged by reset)
6465 0x00FF FFFF [End of RAM]
6468 System Initialization:
6469 ----------------------
6471 In the reset configuration, U-Boot starts at the reset entry point
6472 (on most PowerPC systems at address 0x00000100). Because of the reset
6473 configuration for CS0# this is a mirror of the on board Flash memory.
6474 To be able to re-map memory U-Boot then jumps to its link address.
6475 To be able to implement the initialization code in C, a (small!)
6476 initial stack is set up in the internal Dual Ported RAM (in case CPUs
6477 which provide such a feature like MPC8xx or MPC8260), or in a locked
6478 part of the data cache. After that, U-Boot initializes the CPU core,
6479 the caches and the SIU.
6481 Next, all (potentially) available memory banks are mapped using a
6482 preliminary mapping. For example, we put them on 512 MB boundaries
6483 (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
6484 on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
6485 programmed for SDRAM access. Using the temporary configuration, a
6486 simple memory test is run that determines the size of the SDRAM
6489 When there is more than one SDRAM bank, and the banks are of
6490 different size, the largest is mapped first. For equal size, the first
6491 bank (CS2#) is mapped first. The first mapping is always for address
6492 0x00000000, with any additional banks following immediately to create
6493 contiguous memory starting from 0.
6495 Then, the monitor installs itself at the upper end of the SDRAM area
6496 and allocates memory for use by malloc() and for the global Board
6497 Info data; also, the exception vector code is copied to the low RAM
6498 pages, and the final stack is set up.
6500 Only after this relocation will you have a "normal" C environment;
6501 until that you are restricted in several ways, mostly because you are
6502 running from ROM, and because the code will have to be relocated to a
6506 U-Boot Porting Guide:
6507 ----------------------
6509 [Based on messages by Jerry Van Baren in the U-Boot-Users mailing
6513 int main(int argc, char *argv[])
6515 sighandler_t no_more_time;
6517 signal(SIGALRM, no_more_time);
6518 alarm(PROJECT_DEADLINE - toSec (3 * WEEK));
6520 if (available_money > available_manpower) {
6521 Pay consultant to port U-Boot;
6525 Download latest U-Boot source;
6527 Subscribe to u-boot mailing list;
6530 email("Hi, I am new to U-Boot, how do I get started?");
6533 Read the README file in the top level directory;
6534 Read http://www.denx.de/twiki/bin/view/DULG/Manual;
6535 Read applicable doc/*.README;
6536 Read the source, Luke;
6537 /* find . -name "*.[chS]" | xargs grep -i <keyword> */
6540 if (available_money > toLocalCurrency ($2500))
6543 Add a lot of aggravation and time;
6545 if (a similar board exists) { /* hopefully... */
6546 cp -a board/<similar> board/<myboard>
6547 cp include/configs/<similar>.h include/configs/<myboard>.h
6549 Create your own board support subdirectory;
6550 Create your own board include/configs/<myboard>.h file;
6552 Edit new board/<myboard> files
6553 Edit new include/configs/<myboard>.h
6558 Add / modify source code;
6562 email("Hi, I am having problems...");
6564 Send patch file to the U-Boot email list;
6565 if (reasonable critiques)
6566 Incorporate improvements from email list code review;
6568 Defend code as written;
6574 void no_more_time (int sig)
6583 All contributions to U-Boot should conform to the Linux kernel
6584 coding style; see the file "Documentation/CodingStyle" and the script
6585 "scripts/Lindent" in your Linux kernel source directory.
6587 Source files originating from a different project (for example the
6588 MTD subsystem) are generally exempt from these guidelines and are not
6589 reformatted to ease subsequent migration to newer versions of those
6592 Please note that U-Boot is implemented in C (and to some small parts in
6593 Assembler); no C++ is used, so please do not use C++ style comments (//)
6596 Please also stick to the following formatting rules:
6597 - remove any trailing white space
6598 - use TAB characters for indentation and vertical alignment, not spaces
6599 - make sure NOT to use DOS '\r\n' line feeds
6600 - do not add more than 2 consecutive empty lines to source files
6601 - do not add trailing empty lines to source files
6603 Submissions which do not conform to the standards may be returned
6604 with a request to reformat the changes.
6610 Since the number of patches for U-Boot is growing, we need to
6611 establish some rules. Submissions which do not conform to these rules
6612 may be rejected, even when they contain important and valuable stuff.
6614 Please see http://www.denx.de/wiki/U-Boot/Patches for details.
6616 Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>;
6617 see http://lists.denx.de/mailman/listinfo/u-boot
6619 When you send a patch, please include the following information with
6622 * For bug fixes: a description of the bug and how your patch fixes
6623 this bug. Please try to include a way of demonstrating that the
6624 patch actually fixes something.
6626 * For new features: a description of the feature and your
6629 * A CHANGELOG entry as plaintext (separate from the patch)
6631 * For major contributions, your entry to the CREDITS file
6633 * When you add support for a new board, don't forget to add a
6634 maintainer e-mail address to the boards.cfg file, too.
6636 * If your patch adds new configuration options, don't forget to
6637 document these in the README file.
6639 * The patch itself. If you are using git (which is *strongly*
6640 recommended) you can easily generate the patch using the
6641 "git format-patch". If you then use "git send-email" to send it to
6642 the U-Boot mailing list, you will avoid most of the common problems
6643 with some other mail clients.
6645 If you cannot use git, use "diff -purN OLD NEW". If your version of
6646 diff does not support these options, then get the latest version of
6649 The current directory when running this command shall be the parent
6650 directory of the U-Boot source tree (i. e. please make sure that
6651 your patch includes sufficient directory information for the
6654 We prefer patches as plain text. MIME attachments are discouraged,
6655 and compressed attachments must not be used.
6657 * If one logical set of modifications affects or creates several
6658 files, all these changes shall be submitted in a SINGLE patch file.
6660 * Changesets that contain different, unrelated modifications shall be
6661 submitted as SEPARATE patches, one patch per changeset.
6666 * Before sending the patch, run the MAKEALL script on your patched
6667 source tree and make sure that no errors or warnings are reported
6668 for any of the boards.
6670 * Keep your modifications to the necessary minimum: A patch
6671 containing several unrelated changes or arbitrary reformats will be
6672 returned with a request to re-formatting / split it.
6674 * If you modify existing code, make sure that your new code does not
6675 add to the memory footprint of the code ;-) Small is beautiful!
6676 When adding new features, these should compile conditionally only
6677 (using #ifdef), and the resulting code with the new feature
6678 disabled must not need more memory than the old code without your
6681 * Remember that there is a size limit of 100 kB per message on the
6682 u-boot mailing list. Bigger patches will be moderated. If they are
6683 reasonable and not too big, they will be acknowledged. But patches
6684 bigger than the size limit should be avoided.
projects / people / ms / u-boot.git / blob