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!
693 NOTE: The following can be machine specific errata. These
694 do have ability to provide rudimentary version and machine
695 specific checks, but expect no product checks.
696 CONFIG_ARM_ERRATA_430973
697 CONFIG_ARM_ERRATA_454179
698 CONFIG_ARM_ERRATA_621766
699 CONFIG_ARM_ERRATA_798870
702 CONFIG_TEGRA_SUPPORT_NON_SECURE
704 Support executing U-Boot in non-secure (NS) mode. Certain
705 impossible actions will be skipped if the CPU is in NS mode,
706 such as ARM architectural timer initialization.
708 - Linux Kernel Interface:
711 U-Boot stores all clock information in Hz
712 internally. For binary compatibility with older Linux
713 kernels (which expect the clocks passed in the
714 bd_info data to be in MHz) the environment variable
715 "clocks_in_mhz" can be defined so that U-Boot
716 converts clock data to MHZ before passing it to the
718 When CONFIG_CLOCKS_IN_MHZ is defined, a definition of
719 "clocks_in_mhz=1" is automatically included in the
722 CONFIG_MEMSIZE_IN_BYTES [relevant for MIPS only]
724 When transferring memsize parameter to Linux, some versions
725 expect it to be in bytes, others in MB.
726 Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes.
730 New kernel versions are expecting firmware settings to be
731 passed using flattened device trees (based on open firmware
735 * New libfdt-based support
736 * Adds the "fdt" command
737 * The bootm command automatically updates the fdt
739 OF_CPU - The proper name of the cpus node (only required for
740 MPC512X and MPC5xxx based boards).
741 OF_SOC - The proper name of the soc node (only required for
742 MPC512X and MPC5xxx based boards).
743 OF_TBCLK - The timebase frequency.
744 OF_STDOUT_PATH - The path to the console device
746 boards with QUICC Engines require OF_QE to set UCC MAC
749 CONFIG_OF_BOARD_SETUP
751 Board code has addition modification that it wants to make
752 to the flat device tree before handing it off to the kernel
754 CONFIG_OF_SYSTEM_SETUP
756 Other code has addition modification that it wants to make
757 to the flat device tree before handing it off to the kernel.
758 This causes ft_system_setup() to be called before booting
763 This define fills in the correct boot CPU in the boot
764 param header, the default value is zero if undefined.
768 U-Boot can detect if an IDE device is present or not.
769 If not, and this new config option is activated, U-Boot
770 removes the ATA node from the DTS before booting Linux,
771 so the Linux IDE driver does not probe the device and
772 crash. This is needed for buggy hardware (uc101) where
773 no pull down resistor is connected to the signal IDE5V_DD7.
775 CONFIG_MACH_TYPE [relevant for ARM only][mandatory]
777 This setting is mandatory for all boards that have only one
778 machine type and must be used to specify the machine type
779 number as it appears in the ARM machine registry
780 (see http://www.arm.linux.org.uk/developer/machines/).
781 Only boards that have multiple machine types supported
782 in a single configuration file and the machine type is
783 runtime discoverable, do not have to use this setting.
785 - vxWorks boot parameters:
787 bootvx constructs a valid bootline using the following
788 environments variables: bootfile, ipaddr, serverip, hostname.
789 It loads the vxWorks image pointed bootfile.
791 CONFIG_SYS_VXWORKS_BOOT_DEVICE - The vxworks device name
792 CONFIG_SYS_VXWORKS_MAC_PTR - Ethernet 6 byte MA -address
793 CONFIG_SYS_VXWORKS_SERVERNAME - Name of the server
794 CONFIG_SYS_VXWORKS_BOOT_ADDR - Address of boot parameters
796 CONFIG_SYS_VXWORKS_ADD_PARAMS
798 Add it at the end of the bootline. E.g "u=username pw=secret"
800 Note: If a "bootargs" environment is defined, it will overwride
801 the defaults discussed just above.
803 - Cache Configuration:
804 CONFIG_SYS_ICACHE_OFF - Do not enable instruction cache in U-Boot
805 CONFIG_SYS_DCACHE_OFF - Do not enable data cache in U-Boot
806 CONFIG_SYS_L2CACHE_OFF- Do not enable L2 cache in U-Boot
808 - Cache Configuration for ARM:
809 CONFIG_SYS_L2_PL310 - Enable support for ARM PL310 L2 cache
811 CONFIG_SYS_PL310_BASE - Physical base address of PL310
812 controller register space
817 Define this if you want support for Amba PrimeCell PL010 UARTs.
821 Define this if you want support for Amba PrimeCell PL011 UARTs.
825 If you have Amba PrimeCell PL011 UARTs, set this variable to
826 the clock speed of the UARTs.
830 If you have Amba PrimeCell PL010 or PL011 UARTs on your board,
831 define this to a list of base addresses for each (supported)
832 port. See e.g. include/configs/versatile.h
834 CONFIG_PL011_SERIAL_RLCR
836 Some vendor versions of PL011 serial ports (e.g. ST-Ericsson U8500)
837 have separate receive and transmit line control registers. Set
838 this variable to initialize the extra register.
840 CONFIG_PL011_SERIAL_FLUSH_ON_INIT
842 On some platforms (e.g. U8500) U-Boot is loaded by a second stage
843 boot loader that has already initialized the UART. Define this
844 variable to flush the UART at init time.
846 CONFIG_SERIAL_HW_FLOW_CONTROL
848 Define this variable to enable hw flow control in serial driver.
849 Current user of this option is drivers/serial/nsl16550.c driver
852 Depending on board, define exactly one serial port
853 (like CONFIG_8xx_CONS_SMC1, CONFIG_8xx_CONS_SMC2,
854 CONFIG_8xx_CONS_SCC1, ...), or switch off the serial
855 console by defining CONFIG_8xx_CONS_NONE
857 Note: if CONFIG_8xx_CONS_NONE is defined, the serial
858 port routines must be defined elsewhere
859 (i.e. serial_init(), serial_getc(), ...)
862 Enables console device for a color framebuffer. Needs following
863 defines (cf. smiLynxEM, i8042)
864 VIDEO_FB_LITTLE_ENDIAN graphic memory organisation
866 VIDEO_HW_RECTFILL graphic chip supports
869 VIDEO_HW_BITBLT graphic chip supports
870 bit-blit (cf. smiLynxEM)
871 VIDEO_VISIBLE_COLS visible pixel columns
873 VIDEO_VISIBLE_ROWS visible pixel rows
874 VIDEO_PIXEL_SIZE bytes per pixel
875 VIDEO_DATA_FORMAT graphic data format
876 (0-5, cf. cfb_console.c)
877 VIDEO_FB_ADRS framebuffer address
878 VIDEO_KBD_INIT_FCT keyboard int fct
879 (i.e. i8042_kbd_init())
880 VIDEO_TSTC_FCT test char fct
882 VIDEO_GETC_FCT get char fct
884 CONFIG_CONSOLE_CURSOR cursor drawing on/off
885 (requires blink timer
887 CONFIG_SYS_CONSOLE_BLINK_COUNT blink interval (cf. i8042.c)
888 CONFIG_CONSOLE_TIME display time/date info in
890 (requires CONFIG_CMD_DATE)
891 CONFIG_VIDEO_LOGO display Linux logo in
893 CONFIG_VIDEO_BMP_LOGO use bmp_logo.h instead of
894 linux_logo.h for logo.
895 Requires CONFIG_VIDEO_LOGO
896 CONFIG_CONSOLE_EXTRA_INFO
897 additional board info beside
900 When CONFIG_CFB_CONSOLE_ANSI is defined, console will support
901 a limited number of ANSI escape sequences (cursor control,
902 erase functions and limited graphics rendition control).
904 When CONFIG_CFB_CONSOLE is defined, video console is
905 default i/o. Serial console can be forced with
906 environment 'console=serial'.
908 When CONFIG_SILENT_CONSOLE is defined, all console
909 messages (by U-Boot and Linux!) can be silenced with
910 the "silent" environment variable. See
911 doc/README.silent for more information.
913 CONFIG_SYS_CONSOLE_BG_COL: define the backgroundcolor, default
915 CONFIG_SYS_CONSOLE_FG_COL: define the foregroundcolor, default
919 CONFIG_BAUDRATE - in bps
920 Select one of the baudrates listed in
921 CONFIG_SYS_BAUDRATE_TABLE, see below.
922 CONFIG_SYS_BRGCLK_PRESCALE, baudrate prescale
924 - Console Rx buffer length
925 With CONFIG_SYS_SMC_RXBUFLEN it is possible to define
926 the maximum receive buffer length for the SMC.
927 This option is actual only for 82xx and 8xx possible.
928 If using CONFIG_SYS_SMC_RXBUFLEN also CONFIG_SYS_MAXIDLE
929 must be defined, to setup the maximum idle timeout for
932 - Pre-Console Buffer:
933 Prior to the console being initialised (i.e. serial UART
934 initialised etc) all console output is silently discarded.
935 Defining CONFIG_PRE_CONSOLE_BUFFER will cause U-Boot to
936 buffer any console messages prior to the console being
937 initialised to a buffer of size CONFIG_PRE_CON_BUF_SZ
938 bytes located at CONFIG_PRE_CON_BUF_ADDR. The buffer is
939 a circular buffer, so if more than CONFIG_PRE_CON_BUF_SZ
940 bytes are output before the console is initialised, the
941 earlier bytes are discarded.
943 'Sane' compilers will generate smaller code if
944 CONFIG_PRE_CON_BUF_SZ is a power of 2
946 - Safe printf() functions
947 Define CONFIG_SYS_VSNPRINTF to compile in safe versions of
948 the printf() functions. These are defined in
949 include/vsprintf.h and include snprintf(), vsnprintf() and
950 so on. Code size increase is approximately 300-500 bytes.
951 If this option is not given then these functions will
952 silently discard their buffer size argument - this means
953 you are not getting any overflow checking in this case.
955 - Boot Delay: CONFIG_BOOTDELAY - in seconds
956 Delay before automatically booting the default image;
957 set to -1 to disable autoboot.
958 set to -2 to autoboot with no delay and not check for abort
959 (even when CONFIG_ZERO_BOOTDELAY_CHECK is defined).
961 See doc/README.autoboot for these options that
962 work with CONFIG_BOOTDELAY. None are required.
963 CONFIG_BOOT_RETRY_TIME
964 CONFIG_BOOT_RETRY_MIN
965 CONFIG_AUTOBOOT_KEYED
966 CONFIG_AUTOBOOT_PROMPT
967 CONFIG_AUTOBOOT_DELAY_STR
968 CONFIG_AUTOBOOT_STOP_STR
969 CONFIG_AUTOBOOT_DELAY_STR2
970 CONFIG_AUTOBOOT_STOP_STR2
971 CONFIG_ZERO_BOOTDELAY_CHECK
972 CONFIG_RESET_TO_RETRY
976 Only needed when CONFIG_BOOTDELAY is enabled;
977 define a command string that is automatically executed
978 when no character is read on the console interface
979 within "Boot Delay" after reset.
982 This can be used to pass arguments to the bootm
983 command. The value of CONFIG_BOOTARGS goes into the
984 environment value "bootargs".
986 CONFIG_RAMBOOT and CONFIG_NFSBOOT
987 The value of these goes into the environment as
988 "ramboot" and "nfsboot" respectively, and can be used
989 as a convenience, when switching between booting from
993 CONFIG_BOOTCOUNT_LIMIT
994 Implements a mechanism for detecting a repeating reboot
996 http://www.denx.de/wiki/view/DULG/UBootBootCountLimit
999 If no softreset save registers are found on the hardware
1000 "bootcount" is stored in the environment. To prevent a
1001 saveenv on all reboots, the environment variable
1002 "upgrade_available" is used. If "upgrade_available" is
1003 0, "bootcount" is always 0, if "upgrade_available" is
1004 1 "bootcount" is incremented in the environment.
1005 So the Userspace Applikation must set the "upgrade_available"
1006 and "bootcount" variable to 0, if a boot was successfully.
1008 - Pre-Boot Commands:
1011 When this option is #defined, the existence of the
1012 environment variable "preboot" will be checked
1013 immediately before starting the CONFIG_BOOTDELAY
1014 countdown and/or running the auto-boot command resp.
1015 entering interactive mode.
1017 This feature is especially useful when "preboot" is
1018 automatically generated or modified. For an example
1019 see the LWMON board specific code: here "preboot" is
1020 modified when the user holds down a certain
1021 combination of keys on the (special) keyboard when
1024 - Serial Download Echo Mode:
1026 If defined to 1, all characters received during a
1027 serial download (using the "loads" command) are
1028 echoed back. This might be needed by some terminal
1029 emulations (like "cu"), but may as well just take
1030 time on others. This setting #define's the initial
1031 value of the "loads_echo" environment variable.
1033 - Kgdb Serial Baudrate: (if CONFIG_CMD_KGDB is defined)
1034 CONFIG_KGDB_BAUDRATE
1035 Select one of the baudrates listed in
1036 CONFIG_SYS_BAUDRATE_TABLE, see below.
1038 - Monitor Functions:
1039 Monitor commands can be included or excluded
1040 from the build by using the #include files
1041 <config_cmd_all.h> and #undef'ing unwanted
1042 commands, or using <config_cmd_default.h>
1043 and augmenting with additional #define's
1044 for wanted commands.
1046 The default command configuration includes all commands
1047 except those marked below with a "*".
1049 CONFIG_CMD_AES AES 128 CBC encrypt/decrypt
1050 CONFIG_CMD_ASKENV * ask for env variable
1051 CONFIG_CMD_BDI bdinfo
1052 CONFIG_CMD_BEDBUG * Include BedBug Debugger
1053 CONFIG_CMD_BMP * BMP support
1054 CONFIG_CMD_BSP * Board specific commands
1055 CONFIG_CMD_BOOTD bootd
1056 CONFIG_CMD_BOOTI * ARM64 Linux kernel Image support
1057 CONFIG_CMD_CACHE * icache, dcache
1058 CONFIG_CMD_CLK * clock command support
1059 CONFIG_CMD_CONSOLE coninfo
1060 CONFIG_CMD_CRC32 * crc32
1061 CONFIG_CMD_DATE * support for RTC, date/time...
1062 CONFIG_CMD_DHCP * DHCP support
1063 CONFIG_CMD_DIAG * Diagnostics
1064 CONFIG_CMD_DS4510 * ds4510 I2C gpio commands
1065 CONFIG_CMD_DS4510_INFO * ds4510 I2C info command
1066 CONFIG_CMD_DS4510_MEM * ds4510 I2C eeprom/sram commansd
1067 CONFIG_CMD_DS4510_RST * ds4510 I2C rst command
1068 CONFIG_CMD_DTT * Digital Therm and Thermostat
1069 CONFIG_CMD_ECHO echo arguments
1070 CONFIG_CMD_EDITENV edit env variable
1071 CONFIG_CMD_EEPROM * EEPROM read/write support
1072 CONFIG_CMD_ELF * bootelf, bootvx
1073 CONFIG_CMD_ENV_CALLBACK * display details about env callbacks
1074 CONFIG_CMD_ENV_FLAGS * display details about env flags
1075 CONFIG_CMD_ENV_EXISTS * check existence of env variable
1076 CONFIG_CMD_EXPORTENV * export the environment
1077 CONFIG_CMD_EXT2 * ext2 command support
1078 CONFIG_CMD_EXT4 * ext4 command support
1079 CONFIG_CMD_FS_GENERIC * filesystem commands (e.g. load, ls)
1080 that work for multiple fs types
1081 CONFIG_CMD_FS_UUID * Look up a filesystem UUID
1082 CONFIG_CMD_SAVEENV saveenv
1083 CONFIG_CMD_FDC * Floppy Disk Support
1084 CONFIG_CMD_FAT * FAT command support
1085 CONFIG_CMD_FLASH flinfo, erase, protect
1086 CONFIG_CMD_FPGA FPGA device initialization support
1087 CONFIG_CMD_FUSE * Device fuse support
1088 CONFIG_CMD_GETTIME * Get time since boot
1089 CONFIG_CMD_GO * the 'go' command (exec code)
1090 CONFIG_CMD_GREPENV * search environment
1091 CONFIG_CMD_HASH * calculate hash / digest
1092 CONFIG_CMD_HWFLOW * RTS/CTS hw flow control
1093 CONFIG_CMD_I2C * I2C serial bus support
1094 CONFIG_CMD_IDE * IDE harddisk support
1095 CONFIG_CMD_IMI iminfo
1096 CONFIG_CMD_IMLS List all images found in NOR flash
1097 CONFIG_CMD_IMLS_NAND * List all images found in NAND flash
1098 CONFIG_CMD_IMMAP * IMMR dump support
1099 CONFIG_CMD_IOTRACE * I/O tracing for debugging
1100 CONFIG_CMD_IMPORTENV * import an environment
1101 CONFIG_CMD_INI * import data from an ini file into the env
1102 CONFIG_CMD_IRQ * irqinfo
1103 CONFIG_CMD_ITEST Integer/string test of 2 values
1104 CONFIG_CMD_JFFS2 * JFFS2 Support
1105 CONFIG_CMD_KGDB * kgdb
1106 CONFIG_CMD_LDRINFO * ldrinfo (display Blackfin loader)
1107 CONFIG_CMD_LINK_LOCAL * link-local IP address auto-configuration
1109 CONFIG_CMD_LOADB loadb
1110 CONFIG_CMD_LOADS loads
1111 CONFIG_CMD_MD5SUM * print md5 message digest
1112 (requires CONFIG_CMD_MEMORY and CONFIG_MD5)
1113 CONFIG_CMD_MEMINFO * Display detailed memory information
1114 CONFIG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base,
1116 CONFIG_CMD_MEMTEST * mtest
1117 CONFIG_CMD_MISC Misc functions like sleep etc
1118 CONFIG_CMD_MMC * MMC memory mapped support
1119 CONFIG_CMD_MII * MII utility commands
1120 CONFIG_CMD_MTDPARTS * MTD partition support
1121 CONFIG_CMD_NAND * NAND support
1122 CONFIG_CMD_NET bootp, tftpboot, rarpboot
1123 CONFIG_CMD_NFS NFS support
1124 CONFIG_CMD_PCA953X * PCA953x I2C gpio commands
1125 CONFIG_CMD_PCA953X_INFO * PCA953x I2C gpio info command
1126 CONFIG_CMD_PCI * pciinfo
1127 CONFIG_CMD_PCMCIA * PCMCIA support
1128 CONFIG_CMD_PING * send ICMP ECHO_REQUEST to network
1130 CONFIG_CMD_PORTIO * Port I/O
1131 CONFIG_CMD_READ * Read raw data from partition
1132 CONFIG_CMD_REGINFO * Register dump
1133 CONFIG_CMD_RUN run command in env variable
1134 CONFIG_CMD_SANDBOX * sb command to access sandbox features
1135 CONFIG_CMD_SAVES * save S record dump
1136 CONFIG_CMD_SCSI * SCSI Support
1137 CONFIG_CMD_SDRAM * print SDRAM configuration information
1138 (requires CONFIG_CMD_I2C)
1139 CONFIG_CMD_SETGETDCR Support for DCR Register access
1141 CONFIG_CMD_SF * Read/write/erase SPI NOR flash
1142 CONFIG_CMD_SHA1SUM * print sha1 memory digest
1143 (requires CONFIG_CMD_MEMORY)
1144 CONFIG_CMD_SOFTSWITCH * Soft switch setting command for BF60x
1145 CONFIG_CMD_SOURCE "source" command Support
1146 CONFIG_CMD_SPI * SPI serial bus support
1147 CONFIG_CMD_TFTPSRV * TFTP transfer in server mode
1148 CONFIG_CMD_TFTPPUT * TFTP put command (upload)
1149 CONFIG_CMD_TIME * run command and report execution time (ARM specific)
1150 CONFIG_CMD_TIMER * access to the system tick timer
1151 CONFIG_CMD_USB * USB support
1152 CONFIG_CMD_CDP * Cisco Discover Protocol support
1153 CONFIG_CMD_MFSL * Microblaze FSL support
1154 CONFIG_CMD_XIMG Load part of Multi Image
1155 CONFIG_CMD_UUID * Generate random UUID or GUID string
1157 EXAMPLE: If you want all functions except of network
1158 support you can write:
1160 #include "config_cmd_all.h"
1161 #undef CONFIG_CMD_NET
1164 fdt (flattened device tree) command: CONFIG_OF_LIBFDT
1166 Note: Don't enable the "icache" and "dcache" commands
1167 (configuration option CONFIG_CMD_CACHE) unless you know
1168 what you (and your U-Boot users) are doing. Data
1169 cache cannot be enabled on systems like the 8xx or
1170 8260 (where accesses to the IMMR region must be
1171 uncached), and it cannot be disabled on all other
1172 systems where we (mis-) use the data cache to hold an
1173 initial stack and some data.
1176 XXX - this list needs to get updated!
1178 - Regular expression support:
1180 If this variable is defined, U-Boot is linked against
1181 the SLRE (Super Light Regular Expression) library,
1182 which adds regex support to some commands, as for
1183 example "env grep" and "setexpr".
1187 If this variable is defined, U-Boot will use a device tree
1188 to configure its devices, instead of relying on statically
1189 compiled #defines in the board file. This option is
1190 experimental and only available on a few boards. The device
1191 tree is available in the global data as gd->fdt_blob.
1193 U-Boot needs to get its device tree from somewhere. This can
1194 be done using one of the two options below:
1197 If this variable is defined, U-Boot will embed a device tree
1198 binary in its image. This device tree file should be in the
1199 board directory and called <soc>-<board>.dts. The binary file
1200 is then picked up in board_init_f() and made available through
1201 the global data structure as gd->blob.
1204 If this variable is defined, U-Boot will build a device tree
1205 binary. It will be called u-boot.dtb. Architecture-specific
1206 code will locate it at run-time. Generally this works by:
1208 cat u-boot.bin u-boot.dtb >image.bin
1210 and in fact, U-Boot does this for you, creating a file called
1211 u-boot-dtb.bin which is useful in the common case. You can
1212 still use the individual files if you need something more
1217 If this variable is defined, it enables watchdog
1218 support for the SoC. There must be support in the SoC
1219 specific code for a watchdog. For the 8xx and 8260
1220 CPUs, the SIU Watchdog feature is enabled in the SYPCR
1221 register. When supported for a specific SoC is
1222 available, then no further board specific code should
1223 be needed to use it.
1226 When using a watchdog circuitry external to the used
1227 SoC, then define this variable and provide board
1228 specific code for the "hw_watchdog_reset" function.
1230 CONFIG_AT91_HW_WDT_TIMEOUT
1231 specify the timeout in seconds. default 2 seconds.
1234 CONFIG_VERSION_VARIABLE
1235 If this variable is defined, an environment variable
1236 named "ver" is created by U-Boot showing the U-Boot
1237 version as printed by the "version" command.
1238 Any change to this variable will be reverted at the
1243 When CONFIG_CMD_DATE is selected, the type of the RTC
1244 has to be selected, too. Define exactly one of the
1247 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx
1248 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC
1249 CONFIG_RTC_MC13XXX - use MC13783 or MC13892 RTC
1250 CONFIG_RTC_MC146818 - use MC146818 RTC
1251 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC
1252 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC
1253 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC
1254 CONFIG_RTC_DS1339 - use Maxim, Inc. DS1339 RTC
1255 CONFIG_RTC_DS164x - use Dallas DS164x RTC
1256 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC
1257 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC
1258 CONFIG_SYS_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337
1259 CONFIG_SYS_RV3029_TCR - enable trickle charger on
1262 Note that if the RTC uses I2C, then the I2C interface
1263 must also be configured. See I2C Support, below.
1266 CONFIG_PCA953X - use NXP's PCA953X series I2C GPIO
1268 The CONFIG_SYS_I2C_PCA953X_WIDTH option specifies a list of
1269 chip-ngpio pairs that tell the PCA953X driver the number of
1270 pins supported by a particular chip.
1272 Note that if the GPIO device uses I2C, then the I2C interface
1273 must also be configured. See I2C Support, below.
1276 When CONFIG_IO_TRACE is selected, U-Boot intercepts all I/O
1277 accesses and can checksum them or write a list of them out
1278 to memory. See the 'iotrace' command for details. This is
1279 useful for testing device drivers since it can confirm that
1280 the driver behaves the same way before and after a code
1281 change. Currently this is supported on sandbox and arm. To
1282 add support for your architecture, add '#include <iotrace.h>'
1283 to the bottom of arch/<arch>/include/asm/io.h and test.
1285 Example output from the 'iotrace stats' command is below.
1286 Note that if the trace buffer is exhausted, the checksum will
1287 still continue to operate.
1290 Start: 10000000 (buffer start address)
1291 Size: 00010000 (buffer size)
1292 Offset: 00000120 (current buffer offset)
1293 Output: 10000120 (start + offset)
1294 Count: 00000018 (number of trace records)
1295 CRC32: 9526fb66 (CRC32 of all trace records)
1297 - Timestamp Support:
1299 When CONFIG_TIMESTAMP is selected, the timestamp
1300 (date and time) of an image is printed by image
1301 commands like bootm or iminfo. This option is
1302 automatically enabled when you select CONFIG_CMD_DATE .
1304 - Partition Labels (disklabels) Supported:
1305 Zero or more of the following:
1306 CONFIG_MAC_PARTITION Apple's MacOS partition table.
1307 CONFIG_DOS_PARTITION MS Dos partition table, traditional on the
1308 Intel architecture, USB sticks, etc.
1309 CONFIG_ISO_PARTITION ISO partition table, used on CDROM etc.
1310 CONFIG_EFI_PARTITION GPT partition table, common when EFI is the
1311 bootloader. Note 2TB partition limit; see
1313 CONFIG_MTD_PARTITIONS Memory Technology Device partition table.
1315 If IDE or SCSI support is enabled (CONFIG_CMD_IDE or
1316 CONFIG_CMD_SCSI) you must configure support for at
1317 least one non-MTD partition type as well.
1320 CONFIG_IDE_RESET_ROUTINE - this is defined in several
1321 board configurations files but used nowhere!
1323 CONFIG_IDE_RESET - is this is defined, IDE Reset will
1324 be performed by calling the function
1325 ide_set_reset(int reset)
1326 which has to be defined in a board specific file
1331 Set this to enable ATAPI support.
1336 Set this to enable support for disks larger than 137GB
1337 Also look at CONFIG_SYS_64BIT_LBA.
1338 Whithout these , LBA48 support uses 32bit variables and will 'only'
1339 support disks up to 2.1TB.
1341 CONFIG_SYS_64BIT_LBA:
1342 When enabled, makes the IDE subsystem use 64bit sector addresses.
1346 At the moment only there is only support for the
1347 SYM53C8XX SCSI controller; define
1348 CONFIG_SCSI_SYM53C8XX to enable it.
1350 CONFIG_SYS_SCSI_MAX_LUN [8], CONFIG_SYS_SCSI_MAX_SCSI_ID [7] and
1351 CONFIG_SYS_SCSI_MAX_DEVICE [CONFIG_SYS_SCSI_MAX_SCSI_ID *
1352 CONFIG_SYS_SCSI_MAX_LUN] can be adjusted to define the
1353 maximum numbers of LUNs, SCSI ID's and target
1355 CONFIG_SYS_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz)
1357 The environment variable 'scsidevs' is set to the number of
1358 SCSI devices found during the last scan.
1360 - NETWORK Support (PCI):
1362 Support for Intel 8254x/8257x gigabit chips.
1365 Utility code for direct access to the SPI bus on Intel 8257x.
1366 This does not do anything useful unless you set at least one
1367 of CONFIG_CMD_E1000 or CONFIG_E1000_SPI_GENERIC.
1369 CONFIG_E1000_SPI_GENERIC
1370 Allow generic access to the SPI bus on the Intel 8257x, for
1371 example with the "sspi" command.
1374 Management command for E1000 devices. When used on devices
1375 with SPI support you can reprogram the EEPROM from U-Boot.
1377 CONFIG_E1000_FALLBACK_MAC
1378 default MAC for empty EEPROM after production.
1381 Support for Intel 82557/82559/82559ER chips.
1382 Optional CONFIG_EEPRO100_SROM_WRITE enables EEPROM
1383 write routine for first time initialisation.
1386 Support for Digital 2114x chips.
1387 Optional CONFIG_TULIP_SELECT_MEDIA for board specific
1388 modem chip initialisation (KS8761/QS6611).
1391 Support for National dp83815 chips.
1394 Support for National dp8382[01] gigabit chips.
1396 - NETWORK Support (other):
1398 CONFIG_DRIVER_AT91EMAC
1399 Support for AT91RM9200 EMAC.
1402 Define this to use reduced MII inteface
1404 CONFIG_DRIVER_AT91EMAC_QUIET
1405 If this defined, the driver is quiet.
1406 The driver doen't show link status messages.
1408 CONFIG_CALXEDA_XGMAC
1409 Support for the Calxeda XGMAC device
1412 Support for SMSC's LAN91C96 chips.
1414 CONFIG_LAN91C96_BASE
1415 Define this to hold the physical address
1416 of the LAN91C96's I/O space
1418 CONFIG_LAN91C96_USE_32_BIT
1419 Define this to enable 32 bit addressing
1422 Support for SMSC's LAN91C111 chip
1424 CONFIG_SMC91111_BASE
1425 Define this to hold the physical address
1426 of the device (I/O space)
1428 CONFIG_SMC_USE_32_BIT
1429 Define this if data bus is 32 bits
1431 CONFIG_SMC_USE_IOFUNCS
1432 Define this to use i/o functions instead of macros
1433 (some hardware wont work with macros)
1435 CONFIG_DRIVER_TI_EMAC
1436 Support for davinci emac
1438 CONFIG_SYS_DAVINCI_EMAC_PHY_COUNT
1439 Define this if you have more then 3 PHYs.
1442 Support for Faraday's FTGMAC100 Gigabit SoC Ethernet
1444 CONFIG_FTGMAC100_EGIGA
1445 Define this to use GE link update with gigabit PHY.
1446 Define this if FTGMAC100 is connected to gigabit PHY.
1447 If your system has 10/100 PHY only, it might not occur
1448 wrong behavior. Because PHY usually return timeout or
1449 useless data when polling gigabit status and gigabit
1450 control registers. This behavior won't affect the
1451 correctnessof 10/100 link speed update.
1454 Support for SMSC's LAN911x and LAN921x chips
1457 Define this to hold the physical address
1458 of the device (I/O space)
1460 CONFIG_SMC911X_32_BIT
1461 Define this if data bus is 32 bits
1463 CONFIG_SMC911X_16_BIT
1464 Define this if data bus is 16 bits. If your processor
1465 automatically converts one 32 bit word to two 16 bit
1466 words you may also try CONFIG_SMC911X_32_BIT.
1469 Support for Renesas on-chip Ethernet controller
1471 CONFIG_SH_ETHER_USE_PORT
1472 Define the number of ports to be used
1474 CONFIG_SH_ETHER_PHY_ADDR
1475 Define the ETH PHY's address
1477 CONFIG_SH_ETHER_CACHE_WRITEBACK
1478 If this option is set, the driver enables cache flush.
1482 Support for PWM modul on the imx6.
1486 Support TPM devices.
1489 Support for i2c bus TPM devices. Only one device
1490 per system is supported at this time.
1492 CONFIG_TPM_TIS_I2C_BUS_NUMBER
1493 Define the the i2c bus number for the TPM device
1495 CONFIG_TPM_TIS_I2C_SLAVE_ADDRESS
1496 Define the TPM's address on the i2c bus
1498 CONFIG_TPM_TIS_I2C_BURST_LIMITATION
1499 Define the burst count bytes upper limit
1501 CONFIG_TPM_ATMEL_TWI
1502 Support for Atmel TWI TPM device. Requires I2C support.
1505 Support for generic parallel port TPM devices. Only one device
1506 per system is supported at this time.
1508 CONFIG_TPM_TIS_BASE_ADDRESS
1509 Base address where the generic TPM device is mapped
1510 to. Contemporary x86 systems usually map it at
1514 Add tpm monitor functions.
1515 Requires CONFIG_TPM. If CONFIG_TPM_AUTH_SESSIONS is set, also
1516 provides monitor access to authorized functions.
1519 Define this to enable the TPM support library which provides
1520 functional interfaces to some TPM commands.
1521 Requires support for a TPM device.
1523 CONFIG_TPM_AUTH_SESSIONS
1524 Define this to enable authorized functions in the TPM library.
1525 Requires CONFIG_TPM and CONFIG_SHA1.
1528 At the moment only the UHCI host controller is
1529 supported (PIP405, MIP405, MPC5200); define
1530 CONFIG_USB_UHCI to enable it.
1531 define CONFIG_USB_KEYBOARD to enable the USB Keyboard
1532 and define CONFIG_USB_STORAGE to enable the USB
1535 Supported are USB Keyboards and USB Floppy drives
1537 MPC5200 USB requires additional defines:
1539 for 528 MHz Clock: 0x0001bbbb
1543 for differential drivers: 0x00001000
1544 for single ended drivers: 0x00005000
1545 for differential drivers on PSC3: 0x00000100
1546 for single ended drivers on PSC3: 0x00004100
1547 CONFIG_SYS_USB_EVENT_POLL
1548 May be defined to allow interrupt polling
1549 instead of using asynchronous interrupts
1551 CONFIG_USB_EHCI_TXFIFO_THRESH enables setting of the
1552 txfilltuning field in the EHCI controller on reset.
1554 CONFIG_USB_DWC2_REG_ADDR the physical CPU address of the DWC2
1555 HW module registers.
1558 Define the below if you wish to use the USB console.
1559 Once firmware is rebuilt from a serial console issue the
1560 command "setenv stdin usbtty; setenv stdout usbtty" and
1561 attach your USB cable. The Unix command "dmesg" should print
1562 it has found a new device. The environment variable usbtty
1563 can be set to gserial or cdc_acm to enable your device to
1564 appear to a USB host as a Linux gserial device or a
1565 Common Device Class Abstract Control Model serial device.
1566 If you select usbtty = gserial you should be able to enumerate
1568 # modprobe usbserial vendor=0xVendorID product=0xProductID
1569 else if using cdc_acm, simply setting the environment
1570 variable usbtty to be cdc_acm should suffice. The following
1571 might be defined in YourBoardName.h
1574 Define this to build a UDC device
1577 Define this to have a tty type of device available to
1578 talk to the UDC device
1581 Define this to enable the high speed support for usb
1582 device and usbtty. If this feature is enabled, a routine
1583 int is_usbd_high_speed(void)
1584 also needs to be defined by the driver to dynamically poll
1585 whether the enumeration has succeded at high speed or full
1588 CONFIG_SYS_CONSOLE_IS_IN_ENV
1589 Define this if you want stdin, stdout &/or stderr to
1593 CONFIG_SYS_USB_EXTC_CLK 0xBLAH
1594 Derive USB clock from external clock "blah"
1595 - CONFIG_SYS_USB_EXTC_CLK 0x02
1597 CONFIG_SYS_USB_BRG_CLK 0xBLAH
1598 Derive USB clock from brgclk
1599 - CONFIG_SYS_USB_BRG_CLK 0x04
1601 If you have a USB-IF assigned VendorID then you may wish to
1602 define your own vendor specific values either in BoardName.h
1603 or directly in usbd_vendor_info.h. If you don't define
1604 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME,
1605 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot
1606 should pretend to be a Linux device to it's target host.
1608 CONFIG_USBD_MANUFACTURER
1609 Define this string as the name of your company for
1610 - CONFIG_USBD_MANUFACTURER "my company"
1612 CONFIG_USBD_PRODUCT_NAME
1613 Define this string as the name of your product
1614 - CONFIG_USBD_PRODUCT_NAME "acme usb device"
1616 CONFIG_USBD_VENDORID
1617 Define this as your assigned Vendor ID from the USB
1618 Implementors Forum. This *must* be a genuine Vendor ID
1619 to avoid polluting the USB namespace.
1620 - CONFIG_USBD_VENDORID 0xFFFF
1622 CONFIG_USBD_PRODUCTID
1623 Define this as the unique Product ID
1625 - CONFIG_USBD_PRODUCTID 0xFFFF
1627 - ULPI Layer Support:
1628 The ULPI (UTMI Low Pin (count) Interface) PHYs are supported via
1629 the generic ULPI layer. The generic layer accesses the ULPI PHY
1630 via the platform viewport, so you need both the genric layer and
1631 the viewport enabled. Currently only Chipidea/ARC based
1632 viewport is supported.
1633 To enable the ULPI layer support, define CONFIG_USB_ULPI and
1634 CONFIG_USB_ULPI_VIEWPORT in your board configuration file.
1635 If your ULPI phy needs a different reference clock than the
1636 standard 24 MHz then you have to define CONFIG_ULPI_REF_CLK to
1637 the appropriate value in Hz.
1640 The MMC controller on the Intel PXA is supported. To
1641 enable this define CONFIG_MMC. The MMC can be
1642 accessed from the boot prompt by mapping the device
1643 to physical memory similar to flash. Command line is
1644 enabled with CONFIG_CMD_MMC. The MMC driver also works with
1645 the FAT fs. This is enabled with CONFIG_CMD_FAT.
1648 Support for Renesas on-chip MMCIF controller
1650 CONFIG_SH_MMCIF_ADDR
1651 Define the base address of MMCIF registers
1654 Define the clock frequency for MMCIF
1657 Enable the generic MMC driver
1659 CONFIG_SUPPORT_EMMC_BOOT
1660 Enable some additional features of the eMMC boot partitions.
1662 CONFIG_SUPPORT_EMMC_RPMB
1663 Enable the commands for reading, writing and programming the
1664 key for the Replay Protection Memory Block partition in eMMC.
1666 - USB Device Firmware Update (DFU) class support:
1668 This enables the USB portion of the DFU USB class
1671 This enables the command "dfu" which is used to have
1672 U-Boot create a DFU class device via USB. This command
1673 requires that the "dfu_alt_info" environment variable be
1674 set and define the alt settings to expose to the host.
1677 This enables support for exposing (e)MMC devices via DFU.
1680 This enables support for exposing NAND devices via DFU.
1683 This enables support for exposing RAM via DFU.
1684 Note: DFU spec refer to non-volatile memory usage, but
1685 allow usages beyond the scope of spec - here RAM usage,
1686 one that would help mostly the developer.
1688 CONFIG_SYS_DFU_DATA_BUF_SIZE
1689 Dfu transfer uses a buffer before writing data to the
1690 raw storage device. Make the size (in bytes) of this buffer
1691 configurable. The size of this buffer is also configurable
1692 through the "dfu_bufsiz" environment variable.
1694 CONFIG_SYS_DFU_MAX_FILE_SIZE
1695 When updating files rather than the raw storage device,
1696 we use a static buffer to copy the file into and then write
1697 the buffer once we've been given the whole file. Define
1698 this to the maximum filesize (in bytes) for the buffer.
1699 Default is 4 MiB if undefined.
1701 DFU_DEFAULT_POLL_TIMEOUT
1702 Poll timeout [ms], is the timeout a device can send to the
1703 host. The host must wait for this timeout before sending
1704 a subsequent DFU_GET_STATUS request to the device.
1706 DFU_MANIFEST_POLL_TIMEOUT
1707 Poll timeout [ms], which the device sends to the host when
1708 entering dfuMANIFEST state. Host waits this timeout, before
1709 sending again an USB request to the device.
1711 - USB Device Android Fastboot support:
1713 This enables the command "fastboot" which enables the Android
1714 fastboot mode for the platform's USB device. Fastboot is a USB
1715 protocol for downloading images, flashing and device control
1716 used on Android devices.
1717 See doc/README.android-fastboot for more information.
1719 CONFIG_ANDROID_BOOT_IMAGE
1720 This enables support for booting images which use the Android
1721 image format header.
1723 CONFIG_USB_FASTBOOT_BUF_ADDR
1724 The fastboot protocol requires a large memory buffer for
1725 downloads. Define this to the starting RAM address to use for
1728 CONFIG_USB_FASTBOOT_BUF_SIZE
1729 The fastboot protocol requires a large memory buffer for
1730 downloads. This buffer should be as large as possible for a
1731 platform. Define this to the size available RAM for fastboot.
1733 CONFIG_FASTBOOT_FLASH
1734 The fastboot protocol includes a "flash" command for writing
1735 the downloaded image to a non-volatile storage device. Define
1736 this to enable the "fastboot flash" command.
1738 CONFIG_FASTBOOT_FLASH_MMC_DEV
1739 The fastboot "flash" command requires additional information
1740 regarding the non-volatile storage device. Define this to
1741 the eMMC device that fastboot should use to store the image.
1743 CONFIG_FASTBOOT_GPT_NAME
1744 The fastboot "flash" command supports writing the downloaded
1745 image to the Protective MBR and the Primary GUID Partition
1746 Table. (Additionally, this downloaded image is post-processed
1747 to generate and write the Backup GUID Partition Table.)
1748 This occurs when the specified "partition name" on the
1749 "fastboot flash" command line matches this value.
1750 Default is GPT_ENTRY_NAME (currently "gpt") if undefined.
1752 - Journaling Flash filesystem support:
1753 CONFIG_JFFS2_NAND, CONFIG_JFFS2_NAND_OFF, CONFIG_JFFS2_NAND_SIZE,
1754 CONFIG_JFFS2_NAND_DEV
1755 Define these for a default partition on a NAND device
1757 CONFIG_SYS_JFFS2_FIRST_SECTOR,
1758 CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS
1759 Define these for a default partition on a NOR device
1761 CONFIG_SYS_JFFS_CUSTOM_PART
1762 Define this to create an own partition. You have to provide a
1763 function struct part_info* jffs2_part_info(int part_num)
1765 If you define only one JFFS2 partition you may also want to
1766 #define CONFIG_SYS_JFFS_SINGLE_PART 1
1767 to disable the command chpart. This is the default when you
1768 have not defined a custom partition
1770 - FAT(File Allocation Table) filesystem write function support:
1773 Define this to enable support for saving memory data as a
1774 file in FAT formatted partition.
1776 This will also enable the command "fatwrite" enabling the
1777 user to write files to FAT.
1779 CBFS (Coreboot Filesystem) support
1782 Define this to enable support for reading from a Coreboot
1783 filesystem. Available commands are cbfsinit, cbfsinfo, cbfsls
1786 - FAT(File Allocation Table) filesystem cluster size:
1787 CONFIG_FS_FAT_MAX_CLUSTSIZE
1789 Define the max cluster size for fat operations else
1790 a default value of 65536 will be defined.
1795 Define this to enable standard (PC-Style) keyboard
1799 Standard PC keyboard driver with US (is default) and
1800 GERMAN key layout (switch via environment 'keymap=de') support.
1801 Export function i8042_kbd_init, i8042_tstc and i8042_getc
1802 for cfb_console. Supports cursor blinking.
1805 Enables a Chrome OS keyboard using the CROS_EC interface.
1806 This uses CROS_EC to communicate with a second microcontroller
1807 which provides key scans on request.
1812 Define this to enable video support (for output to
1815 CONFIG_VIDEO_CT69000
1817 Enable Chips & Technologies 69000 Video chip
1819 CONFIG_VIDEO_SMI_LYNXEM
1820 Enable Silicon Motion SMI 712/710/810 Video chip. The
1821 video output is selected via environment 'videoout'
1822 (1 = LCD and 2 = CRT). If videoout is undefined, CRT is
1825 For the CT69000 and SMI_LYNXEM drivers, videomode is
1826 selected via environment 'videomode'. Two different ways
1828 - "videomode=num" 'num' is a standard LiLo mode numbers.
1829 Following standard modes are supported (* is default):
1831 Colors 640x480 800x600 1024x768 1152x864 1280x1024
1832 -------------+---------------------------------------------
1833 8 bits | 0x301* 0x303 0x305 0x161 0x307
1834 15 bits | 0x310 0x313 0x316 0x162 0x319
1835 16 bits | 0x311 0x314 0x317 0x163 0x31A
1836 24 bits | 0x312 0x315 0x318 ? 0x31B
1837 -------------+---------------------------------------------
1838 (i.e. setenv videomode 317; saveenv; reset;)
1840 - "videomode=bootargs" all the video parameters are parsed
1841 from the bootargs. (See drivers/video/videomodes.c)
1844 CONFIG_VIDEO_SED13806
1845 Enable Epson SED13806 driver. This driver supports 8bpp
1846 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP
1847 or CONFIG_VIDEO_SED13806_16BPP
1850 Enable the Freescale DIU video driver. Reference boards for
1851 SOCs that have a DIU should define this macro to enable DIU
1852 support, and should also define these other macros:
1858 CONFIG_VIDEO_SW_CURSOR
1859 CONFIG_VGA_AS_SINGLE_DEVICE
1861 CONFIG_VIDEO_BMP_LOGO
1863 The DIU driver will look for the 'video-mode' environment
1864 variable, and if defined, enable the DIU as a console during
1865 boot. See the documentation file README.video for a
1866 description of this variable.
1870 Enable the VGA video / BIOS for x86. The alternative if you
1871 are using coreboot is to use the coreboot frame buffer
1878 Define this to enable a custom keyboard support.
1879 This simply calls drv_keyboard_init() which must be
1880 defined in your board-specific files.
1881 The only board using this so far is RBC823.
1883 - LCD Support: CONFIG_LCD
1885 Define this to enable LCD support (for output to LCD
1886 display); also select one of the supported displays
1887 by defining one of these:
1891 HITACHI TX09D70VM1CCA, 3.5", 240x320.
1893 CONFIG_NEC_NL6448AC33:
1895 NEC NL6448AC33-18. Active, color, single scan.
1897 CONFIG_NEC_NL6448BC20
1899 NEC NL6448BC20-08. 6.5", 640x480.
1900 Active, color, single scan.
1902 CONFIG_NEC_NL6448BC33_54
1904 NEC NL6448BC33-54. 10.4", 640x480.
1905 Active, color, single scan.
1909 Sharp 320x240. Active, color, single scan.
1910 It isn't 16x9, and I am not sure what it is.
1912 CONFIG_SHARP_LQ64D341
1914 Sharp LQ64D341 display, 640x480.
1915 Active, color, single scan.
1919 HLD1045 display, 640x480.
1920 Active, color, single scan.
1924 Optrex CBL50840-2 NF-FW 99 22 M5
1926 Hitachi LMG6912RPFC-00T
1930 320x240. Black & white.
1932 Normally display is black on white background; define
1933 CONFIG_SYS_WHITE_ON_BLACK to get it inverted.
1935 CONFIG_LCD_ALIGNMENT
1937 Normally the LCD is page-aligned (typically 4KB). If this is
1938 defined then the LCD will be aligned to this value instead.
1939 For ARM it is sometimes useful to use MMU_SECTION_SIZE
1940 here, since it is cheaper to change data cache settings on
1941 a per-section basis.
1943 CONFIG_CONSOLE_SCROLL_LINES
1945 When the console need to be scrolled, this is the number of
1946 lines to scroll by. It defaults to 1. Increasing this makes
1947 the console jump but can help speed up operation when scrolling
1952 Support drawing of RLE8-compressed bitmaps on the LCD.
1956 Enables an 'i2c edid' command which can read EDID
1957 information over I2C from an attached LCD display.
1959 - Splash Screen Support: CONFIG_SPLASH_SCREEN
1961 If this option is set, the environment is checked for
1962 a variable "splashimage". If found, the usual display
1963 of logo, copyright and system information on the LCD
1964 is suppressed and the BMP image at the address
1965 specified in "splashimage" is loaded instead. The
1966 console is redirected to the "nulldev", too. This
1967 allows for a "silent" boot where a splash screen is
1968 loaded very quickly after power-on.
1970 CONFIG_SPLASHIMAGE_GUARD
1972 If this option is set, then U-Boot will prevent the environment
1973 variable "splashimage" from being set to a problematic address
1974 (see README.displaying-bmps).
1975 This option is useful for targets where, due to alignment
1976 restrictions, an improperly aligned BMP image will cause a data
1977 abort. If you think you will not have problems with unaligned
1978 accesses (for example because your toolchain prevents them)
1979 there is no need to set this option.
1981 CONFIG_SPLASH_SCREEN_ALIGN
1983 If this option is set the splash image can be freely positioned
1984 on the screen. Environment variable "splashpos" specifies the
1985 position as "x,y". If a positive number is given it is used as
1986 number of pixel from left/top. If a negative number is given it
1987 is used as number of pixel from right/bottom. You can also
1988 specify 'm' for centering the image.
1991 setenv splashpos m,m
1992 => image at center of screen
1994 setenv splashpos 30,20
1995 => image at x = 30 and y = 20
1997 setenv splashpos -10,m
1998 => vertically centered image
1999 at x = dspWidth - bmpWidth - 9
2001 - Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP
2003 If this option is set, additionally to standard BMP
2004 images, gzipped BMP images can be displayed via the
2005 splashscreen support or the bmp command.
2007 - Run length encoded BMP image (RLE8) support: CONFIG_VIDEO_BMP_RLE8
2009 If this option is set, 8-bit RLE compressed BMP images
2010 can be displayed via the splashscreen support or the
2013 - Do compressing for memory range:
2016 If this option is set, it would use zlib deflate method
2017 to compress the specified memory at its best effort.
2019 - Compression support:
2022 Enabled by default to support gzip compressed images.
2026 If this option is set, support for bzip2 compressed
2027 images is included. If not, only uncompressed and gzip
2028 compressed images are supported.
2030 NOTE: the bzip2 algorithm requires a lot of RAM, so
2031 the malloc area (as defined by CONFIG_SYS_MALLOC_LEN) should
2036 If this option is set, support for lzma compressed
2039 Note: The LZMA algorithm adds between 2 and 4KB of code and it
2040 requires an amount of dynamic memory that is given by the
2043 (1846 + 768 << (lc + lp)) * sizeof(uint16)
2045 Where lc and lp stand for, respectively, Literal context bits
2046 and Literal pos bits.
2048 This value is upper-bounded by 14MB in the worst case. Anyway,
2049 for a ~4MB large kernel image, we have lc=3 and lp=0 for a
2050 total amount of (1846 + 768 << (3 + 0)) * 2 = ~41KB... that is
2051 a very small buffer.
2053 Use the lzmainfo tool to determinate the lc and lp values and
2054 then calculate the amount of needed dynamic memory (ensuring
2055 the appropriate CONFIG_SYS_MALLOC_LEN value).
2059 If this option is set, support for LZO compressed images
2065 The address of PHY on MII bus.
2067 CONFIG_PHY_CLOCK_FREQ (ppc4xx)
2069 The clock frequency of the MII bus
2073 If this option is set, support for speed/duplex
2074 detection of gigabit PHY is included.
2076 CONFIG_PHY_RESET_DELAY
2078 Some PHY like Intel LXT971A need extra delay after
2079 reset before any MII register access is possible.
2080 For such PHY, set this option to the usec delay
2081 required. (minimum 300usec for LXT971A)
2083 CONFIG_PHY_CMD_DELAY (ppc4xx)
2085 Some PHY like Intel LXT971A need extra delay after
2086 command issued before MII status register can be read
2096 Define a default value for Ethernet address to use
2097 for the respective Ethernet interface, in case this
2098 is not determined automatically.
2103 Define a default value for the IP address to use for
2104 the default Ethernet interface, in case this is not
2105 determined through e.g. bootp.
2106 (Environment variable "ipaddr")
2108 - Server IP address:
2111 Defines a default value for the IP address of a TFTP
2112 server to contact when using the "tftboot" command.
2113 (Environment variable "serverip")
2115 CONFIG_KEEP_SERVERADDR
2117 Keeps the server's MAC address, in the env 'serveraddr'
2118 for passing to bootargs (like Linux's netconsole option)
2120 - Gateway IP address:
2123 Defines a default value for the IP address of the
2124 default router where packets to other networks are
2126 (Environment variable "gatewayip")
2131 Defines a default value for the subnet mask (or
2132 routing prefix) which is used to determine if an IP
2133 address belongs to the local subnet or needs to be
2134 forwarded through a router.
2135 (Environment variable "netmask")
2137 - Multicast TFTP Mode:
2140 Defines whether you want to support multicast TFTP as per
2141 rfc-2090; for example to work with atftp. Lets lots of targets
2142 tftp down the same boot image concurrently. Note: the Ethernet
2143 driver in use must provide a function: mcast() to join/leave a
2146 - BOOTP Recovery Mode:
2147 CONFIG_BOOTP_RANDOM_DELAY
2149 If you have many targets in a network that try to
2150 boot using BOOTP, you may want to avoid that all
2151 systems send out BOOTP requests at precisely the same
2152 moment (which would happen for instance at recovery
2153 from a power failure, when all systems will try to
2154 boot, thus flooding the BOOTP server. Defining
2155 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
2156 inserted before sending out BOOTP requests. The
2157 following delays are inserted then:
2159 1st BOOTP request: delay 0 ... 1 sec
2160 2nd BOOTP request: delay 0 ... 2 sec
2161 3rd BOOTP request: delay 0 ... 4 sec
2163 BOOTP requests: delay 0 ... 8 sec
2165 CONFIG_BOOTP_ID_CACHE_SIZE
2167 BOOTP packets are uniquely identified using a 32-bit ID. The
2168 server will copy the ID from client requests to responses and
2169 U-Boot will use this to determine if it is the destination of
2170 an incoming response. Some servers will check that addresses
2171 aren't in use before handing them out (usually using an ARP
2172 ping) and therefore take up to a few hundred milliseconds to
2173 respond. Network congestion may also influence the time it
2174 takes for a response to make it back to the client. If that
2175 time is too long, U-Boot will retransmit requests. In order
2176 to allow earlier responses to still be accepted after these
2177 retransmissions, U-Boot's BOOTP client keeps a small cache of
2178 IDs. The CONFIG_BOOTP_ID_CACHE_SIZE controls the size of this
2179 cache. The default is to keep IDs for up to four outstanding
2180 requests. Increasing this will allow U-Boot to accept offers
2181 from a BOOTP client in networks with unusually high latency.
2183 - BOOTP Random transaction ID:
2184 CONFIG_BOOTP_RANDOM_ID
2186 The standard algorithm to generate a DHCP/BOOTP transaction ID
2187 by using the MAC address and the current time stamp may not
2188 quite unlikely produce duplicate transaction IDs from different
2189 clients in the same network. This option creates a transaction
2190 ID using the rand() function. Provided that the RNG has been
2191 seeded well, this should guarantee unique transaction IDs
2194 - DHCP Advanced Options:
2195 You can fine tune the DHCP functionality by defining
2196 CONFIG_BOOTP_* symbols:
2198 CONFIG_BOOTP_SUBNETMASK
2199 CONFIG_BOOTP_GATEWAY
2200 CONFIG_BOOTP_HOSTNAME
2201 CONFIG_BOOTP_NISDOMAIN
2202 CONFIG_BOOTP_BOOTPATH
2203 CONFIG_BOOTP_BOOTFILESIZE
2206 CONFIG_BOOTP_SEND_HOSTNAME
2207 CONFIG_BOOTP_NTPSERVER
2208 CONFIG_BOOTP_TIMEOFFSET
2209 CONFIG_BOOTP_VENDOREX
2210 CONFIG_BOOTP_MAY_FAIL
2212 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip
2213 environment variable, not the BOOTP server.
2215 CONFIG_BOOTP_MAY_FAIL - If the DHCP server is not found
2216 after the configured retry count, the call will fail
2217 instead of starting over. This can be used to fail over
2218 to Link-local IP address configuration if the DHCP server
2221 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS
2222 serverip from a DHCP server, it is possible that more
2223 than one DNS serverip is offered to the client.
2224 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS
2225 serverip will be stored in the additional environment
2226 variable "dnsip2". The first DNS serverip is always
2227 stored in the variable "dnsip", when CONFIG_BOOTP_DNS
2230 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable
2231 to do a dynamic update of a DNS server. To do this, they
2232 need the hostname of the DHCP requester.
2233 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content
2234 of the "hostname" environment variable is passed as
2235 option 12 to the DHCP server.
2237 CONFIG_BOOTP_DHCP_REQUEST_DELAY
2239 A 32bit value in microseconds for a delay between
2240 receiving a "DHCP Offer" and sending the "DHCP Request".
2241 This fixes a problem with certain DHCP servers that don't
2242 respond 100% of the time to a "DHCP request". E.g. On an
2243 AT91RM9200 processor running at 180MHz, this delay needed
2244 to be *at least* 15,000 usec before a Windows Server 2003
2245 DHCP server would reply 100% of the time. I recommend at
2246 least 50,000 usec to be safe. The alternative is to hope
2247 that one of the retries will be successful but note that
2248 the DHCP timeout and retry process takes a longer than
2251 - Link-local IP address negotiation:
2252 Negotiate with other link-local clients on the local network
2253 for an address that doesn't require explicit configuration.
2254 This is especially useful if a DHCP server cannot be guaranteed
2255 to exist in all environments that the device must operate.
2257 See doc/README.link-local for more information.
2260 CONFIG_CDP_DEVICE_ID
2262 The device id used in CDP trigger frames.
2264 CONFIG_CDP_DEVICE_ID_PREFIX
2266 A two character string which is prefixed to the MAC address
2271 A printf format string which contains the ascii name of
2272 the port. Normally is set to "eth%d" which sets
2273 eth0 for the first Ethernet, eth1 for the second etc.
2275 CONFIG_CDP_CAPABILITIES
2277 A 32bit integer which indicates the device capabilities;
2278 0x00000010 for a normal host which does not forwards.
2282 An ascii string containing the version of the software.
2286 An ascii string containing the name of the platform.
2290 A 32bit integer sent on the trigger.
2292 CONFIG_CDP_POWER_CONSUMPTION
2294 A 16bit integer containing the power consumption of the
2295 device in .1 of milliwatts.
2297 CONFIG_CDP_APPLIANCE_VLAN_TYPE
2299 A byte containing the id of the VLAN.
2301 - Status LED: CONFIG_STATUS_LED
2303 Several configurations allow to display the current
2304 status using a LED. For instance, the LED will blink
2305 fast while running U-Boot code, stop blinking as
2306 soon as a reply to a BOOTP request was received, and
2307 start blinking slow once the Linux kernel is running
2308 (supported by a status LED driver in the Linux
2309 kernel). Defining CONFIG_STATUS_LED enables this
2315 The status LED can be connected to a GPIO pin.
2316 In such cases, the gpio_led driver can be used as a
2317 status LED backend implementation. Define CONFIG_GPIO_LED
2318 to include the gpio_led driver in the U-Boot binary.
2320 CONFIG_GPIO_LED_INVERTED_TABLE
2321 Some GPIO connected LEDs may have inverted polarity in which
2322 case the GPIO high value corresponds to LED off state and
2323 GPIO low value corresponds to LED on state.
2324 In such cases CONFIG_GPIO_LED_INVERTED_TABLE may be defined
2325 with a list of GPIO LEDs that have inverted polarity.
2327 - CAN Support: CONFIG_CAN_DRIVER
2329 Defining CONFIG_CAN_DRIVER enables CAN driver support
2330 on those systems that support this (optional)
2331 feature, like the TQM8xxL modules.
2333 - I2C Support: CONFIG_SYS_I2C
2335 This enable the NEW i2c subsystem, and will allow you to use
2336 i2c commands at the u-boot command line (as long as you set
2337 CONFIG_CMD_I2C in CONFIG_COMMANDS) and communicate with i2c
2338 based realtime clock chips or other i2c devices. See
2339 common/cmd_i2c.c for a description of the command line
2342 ported i2c driver to the new framework:
2343 - drivers/i2c/soft_i2c.c:
2344 - activate first bus with CONFIG_SYS_I2C_SOFT define
2345 CONFIG_SYS_I2C_SOFT_SPEED and CONFIG_SYS_I2C_SOFT_SLAVE
2346 for defining speed and slave address
2347 - activate second bus with I2C_SOFT_DECLARATIONS2 define
2348 CONFIG_SYS_I2C_SOFT_SPEED_2 and CONFIG_SYS_I2C_SOFT_SLAVE_2
2349 for defining speed and slave address
2350 - activate third bus with I2C_SOFT_DECLARATIONS3 define
2351 CONFIG_SYS_I2C_SOFT_SPEED_3 and CONFIG_SYS_I2C_SOFT_SLAVE_3
2352 for defining speed and slave address
2353 - activate fourth bus with I2C_SOFT_DECLARATIONS4 define
2354 CONFIG_SYS_I2C_SOFT_SPEED_4 and CONFIG_SYS_I2C_SOFT_SLAVE_4
2355 for defining speed and slave address
2357 - drivers/i2c/fsl_i2c.c:
2358 - activate i2c driver with CONFIG_SYS_I2C_FSL
2359 define CONFIG_SYS_FSL_I2C_OFFSET for setting the register
2360 offset CONFIG_SYS_FSL_I2C_SPEED for the i2c speed and
2361 CONFIG_SYS_FSL_I2C_SLAVE for the slave addr of the first
2363 - If your board supports a second fsl i2c bus, define
2364 CONFIG_SYS_FSL_I2C2_OFFSET for the register offset
2365 CONFIG_SYS_FSL_I2C2_SPEED for the speed and
2366 CONFIG_SYS_FSL_I2C2_SLAVE for the slave address of the
2369 - drivers/i2c/tegra_i2c.c:
2370 - activate this driver with CONFIG_SYS_I2C_TEGRA
2371 - This driver adds 4 i2c buses with a fix speed from
2372 100000 and the slave addr 0!
2374 - drivers/i2c/ppc4xx_i2c.c
2375 - activate this driver with CONFIG_SYS_I2C_PPC4XX
2376 - CONFIG_SYS_I2C_PPC4XX_CH0 activate hardware channel 0
2377 - CONFIG_SYS_I2C_PPC4XX_CH1 activate hardware channel 1
2379 - drivers/i2c/i2c_mxc.c
2380 - activate this driver with CONFIG_SYS_I2C_MXC
2381 - define speed for bus 1 with CONFIG_SYS_MXC_I2C1_SPEED
2382 - define slave for bus 1 with CONFIG_SYS_MXC_I2C1_SLAVE
2383 - define speed for bus 2 with CONFIG_SYS_MXC_I2C2_SPEED
2384 - define slave for bus 2 with CONFIG_SYS_MXC_I2C2_SLAVE
2385 - define speed for bus 3 with CONFIG_SYS_MXC_I2C3_SPEED
2386 - define slave for bus 3 with CONFIG_SYS_MXC_I2C3_SLAVE
2387 If those defines are not set, default value is 100000
2388 for speed, and 0 for slave.
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_ CONFIG_ETHADDR
2864 _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 - DataFlash Support:
3039 CONFIG_HAS_DATAFLASH
3041 Defining this option enables DataFlash features and
3042 allows to read/write in Dataflash via the standard
3045 - Serial Flash support
3048 Defining this option enables SPI flash commands
3049 'sf probe/read/write/erase/update'.
3051 Usage requires an initial 'probe' to define the serial
3052 flash parameters, followed by read/write/erase/update
3055 The following defaults may be provided by the platform
3056 to handle the common case when only a single serial
3057 flash is present on the system.
3059 CONFIG_SF_DEFAULT_BUS Bus identifier
3060 CONFIG_SF_DEFAULT_CS Chip-select
3061 CONFIG_SF_DEFAULT_MODE (see include/spi.h)
3062 CONFIG_SF_DEFAULT_SPEED in Hz
3066 Define this option to include a destructive SPI flash
3069 CONFIG_SPI_FLASH_BAR Ban/Extended Addr Reg
3071 Define this option to use the Bank addr/Extended addr
3072 support on SPI flashes which has size > 16Mbytes.
3074 CONFIG_SF_DUAL_FLASH Dual flash memories
3076 Define this option to use dual flash support where two flash
3077 memories can be connected with a given cs line.
3078 Currently Xilinx Zynq qspi supports these type of connections.
3080 CONFIG_SYS_SPI_ST_ENABLE_WP_PIN
3081 enable the W#/Vpp signal to disable writing to the status
3082 register on ST MICRON flashes like the N25Q128.
3083 The status register write enable/disable bit, combined with
3084 the W#/VPP signal provides hardware data protection for the
3085 device as follows: When the enable/disable bit is set to 1,
3086 and the W#/VPP signal is driven LOW, the status register
3087 nonvolatile bits become read-only and the WRITE STATUS REGISTER
3088 operation will not execute. The only way to exit this
3089 hardware-protected mode is to drive W#/VPP HIGH.
3091 - SystemACE Support:
3094 Adding this option adds support for Xilinx SystemACE
3095 chips attached via some sort of local bus. The address
3096 of the chip must also be defined in the
3097 CONFIG_SYS_SYSTEMACE_BASE macro. For example:
3099 #define CONFIG_SYSTEMACE
3100 #define CONFIG_SYS_SYSTEMACE_BASE 0xf0000000
3102 When SystemACE support is added, the "ace" device type
3103 becomes available to the fat commands, i.e. fatls.
3105 - TFTP Fixed UDP Port:
3108 If this is defined, the environment variable tftpsrcp
3109 is used to supply the TFTP UDP source port value.
3110 If tftpsrcp isn't defined, the normal pseudo-random port
3111 number generator is used.
3113 Also, the environment variable tftpdstp is used to supply
3114 the TFTP UDP destination port value. If tftpdstp isn't
3115 defined, the normal port 69 is used.
3117 The purpose for tftpsrcp is to allow a TFTP server to
3118 blindly start the TFTP transfer using the pre-configured
3119 target IP address and UDP port. This has the effect of
3120 "punching through" the (Windows XP) firewall, allowing
3121 the remainder of the TFTP transfer to proceed normally.
3122 A better solution is to properly configure the firewall,
3123 but sometimes that is not allowed.
3128 This enables a generic 'hash' command which can produce
3129 hashes / digests from a few algorithms (e.g. SHA1, SHA256).
3133 Enable the hash verify command (hash -v). This adds to code
3136 CONFIG_SHA1 - This option enables support of hashing using SHA1
3137 algorithm. The hash is calculated in software.
3138 CONFIG_SHA256 - This option enables support of hashing using
3139 SHA256 algorithm. The hash is calculated in software.
3140 CONFIG_SHA_HW_ACCEL - This option enables hardware acceleration
3141 for SHA1/SHA256 hashing.
3142 This affects the 'hash' command and also the
3143 hash_lookup_algo() function.
3144 CONFIG_SHA_PROG_HW_ACCEL - This option enables
3145 hardware-acceleration for SHA1/SHA256 progressive hashing.
3146 Data can be streamed in a block at a time and the hashing
3147 is performed in hardware.
3149 Note: There is also a sha1sum command, which should perhaps
3150 be deprecated in favour of 'hash sha1'.
3152 - Freescale i.MX specific commands:
3153 CONFIG_CMD_HDMIDETECT
3154 This enables 'hdmidet' command which returns true if an
3155 HDMI monitor is detected. This command is i.MX 6 specific.
3158 This enables the 'bmode' (bootmode) command for forcing
3159 a boot from specific media.
3161 This is useful for forcing the ROM's usb downloader to
3162 activate upon a watchdog reset which is nice when iterating
3163 on U-Boot. Using the reset button or running bmode normal
3164 will set it back to normal. This command currently
3165 supports i.MX53 and i.MX6.
3170 This enables the RSA algorithm used for FIT image verification
3171 in U-Boot. See doc/uImage.FIT/signature.txt for more information.
3173 The Modular Exponentiation algorithm in RSA is implemented using
3174 driver model. So CONFIG_DM needs to be enabled by default for this
3175 library to function.
3177 The signing part is build into mkimage regardless of this
3178 option. The software based modular exponentiation is built into
3179 mkimage irrespective of this option.
3181 - bootcount support:
3182 CONFIG_BOOTCOUNT_LIMIT
3184 This enables the bootcounter support, see:
3185 http://www.denx.de/wiki/DULG/UBootBootCountLimit
3188 enable special bootcounter support on at91sam9xe based boards.
3190 enable special bootcounter support on blackfin based boards.
3192 enable special bootcounter support on da850 based boards.
3193 CONFIG_BOOTCOUNT_RAM
3194 enable support for the bootcounter in RAM
3195 CONFIG_BOOTCOUNT_I2C
3196 enable support for the bootcounter on an i2c (like RTC) device.
3197 CONFIG_SYS_I2C_RTC_ADDR = i2c chip address
3198 CONFIG_SYS_BOOTCOUNT_ADDR = i2c addr which is used for
3200 CONFIG_BOOTCOUNT_ALEN = address len
3202 - Show boot progress:
3203 CONFIG_SHOW_BOOT_PROGRESS
3205 Defining this option allows to add some board-
3206 specific code (calling a user-provided function
3207 "show_boot_progress(int)") that enables you to show
3208 the system's boot progress on some display (for
3209 example, some LED's) on your board. At the moment,
3210 the following checkpoints are implemented:
3212 - Detailed boot stage timing
3214 Define this option to get detailed timing of each stage
3215 of the boot process.
3217 CONFIG_BOOTSTAGE_USER_COUNT
3218 This is the number of available user bootstage records.
3219 Each time you call bootstage_mark(BOOTSTAGE_ID_ALLOC, ...)
3220 a new ID will be allocated from this stash. If you exceed
3221 the limit, recording will stop.
3223 CONFIG_BOOTSTAGE_REPORT
3224 Define this to print a report before boot, similar to this:
3226 Timer summary in microseconds:
3229 3,575,678 3,575,678 board_init_f start
3230 3,575,695 17 arch_cpu_init A9
3231 3,575,777 82 arch_cpu_init done
3232 3,659,598 83,821 board_init_r start
3233 3,910,375 250,777 main_loop
3234 29,916,167 26,005,792 bootm_start
3235 30,361,327 445,160 start_kernel
3237 CONFIG_CMD_BOOTSTAGE
3238 Add a 'bootstage' command which supports printing a report
3239 and un/stashing of bootstage data.
3241 CONFIG_BOOTSTAGE_FDT
3242 Stash the bootstage information in the FDT. A root 'bootstage'
3243 node is created with each bootstage id as a child. Each child
3244 has a 'name' property and either 'mark' containing the
3245 mark time in microsecond, or 'accum' containing the
3246 accumulated time for that bootstage id in microseconds.
3251 name = "board_init_f";
3260 Code in the Linux kernel can find this in /proc/devicetree.
3262 Legacy uImage format:
3265 1 common/cmd_bootm.c before attempting to boot an image
3266 -1 common/cmd_bootm.c Image header has bad magic number
3267 2 common/cmd_bootm.c Image header has correct magic number
3268 -2 common/cmd_bootm.c Image header has bad checksum
3269 3 common/cmd_bootm.c Image header has correct checksum
3270 -3 common/cmd_bootm.c Image data has bad checksum
3271 4 common/cmd_bootm.c Image data has correct checksum
3272 -4 common/cmd_bootm.c Image is for unsupported architecture
3273 5 common/cmd_bootm.c Architecture check OK
3274 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi)
3275 6 common/cmd_bootm.c Image Type check OK
3276 -6 common/cmd_bootm.c gunzip uncompression error
3277 -7 common/cmd_bootm.c Unimplemented compression type
3278 7 common/cmd_bootm.c Uncompression OK
3279 8 common/cmd_bootm.c No uncompress/copy overwrite error
3280 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX)
3282 9 common/image.c Start initial ramdisk verification
3283 -10 common/image.c Ramdisk header has bad magic number
3284 -11 common/image.c Ramdisk header has bad checksum
3285 10 common/image.c Ramdisk header is OK
3286 -12 common/image.c Ramdisk data has bad checksum
3287 11 common/image.c Ramdisk data has correct checksum
3288 12 common/image.c Ramdisk verification complete, start loading
3289 -13 common/image.c Wrong Image Type (not PPC Linux ramdisk)
3290 13 common/image.c Start multifile image verification
3291 14 common/image.c No initial ramdisk, no multifile, continue.
3293 15 arch/<arch>/lib/bootm.c All preparation done, transferring control to OS
3295 -30 arch/powerpc/lib/board.c Fatal error, hang the system
3296 -31 post/post.c POST test failed, detected by post_output_backlog()
3297 -32 post/post.c POST test failed, detected by post_run_single()
3299 34 common/cmd_doc.c before loading a Image from a DOC device
3300 -35 common/cmd_doc.c Bad usage of "doc" command
3301 35 common/cmd_doc.c correct usage of "doc" command
3302 -36 common/cmd_doc.c No boot device
3303 36 common/cmd_doc.c correct boot device
3304 -37 common/cmd_doc.c Unknown Chip ID on boot device
3305 37 common/cmd_doc.c correct chip ID found, device available
3306 -38 common/cmd_doc.c Read Error on boot device
3307 38 common/cmd_doc.c reading Image header from DOC device OK
3308 -39 common/cmd_doc.c Image header has bad magic number
3309 39 common/cmd_doc.c Image header has correct magic number
3310 -40 common/cmd_doc.c Error reading Image from DOC device
3311 40 common/cmd_doc.c Image header has correct magic number
3312 41 common/cmd_ide.c before loading a Image from a IDE device
3313 -42 common/cmd_ide.c Bad usage of "ide" command
3314 42 common/cmd_ide.c correct usage of "ide" command
3315 -43 common/cmd_ide.c No boot device
3316 43 common/cmd_ide.c boot device found
3317 -44 common/cmd_ide.c Device not available
3318 44 common/cmd_ide.c Device available
3319 -45 common/cmd_ide.c wrong partition selected
3320 45 common/cmd_ide.c partition selected
3321 -46 common/cmd_ide.c Unknown partition table
3322 46 common/cmd_ide.c valid partition table found
3323 -47 common/cmd_ide.c Invalid partition type
3324 47 common/cmd_ide.c correct partition type
3325 -48 common/cmd_ide.c Error reading Image Header on boot device
3326 48 common/cmd_ide.c reading Image Header from IDE device OK
3327 -49 common/cmd_ide.c Image header has bad magic number
3328 49 common/cmd_ide.c Image header has correct magic number
3329 -50 common/cmd_ide.c Image header has bad checksum
3330 50 common/cmd_ide.c Image header has correct checksum
3331 -51 common/cmd_ide.c Error reading Image from IDE device
3332 51 common/cmd_ide.c reading Image from IDE device OK
3333 52 common/cmd_nand.c before loading a Image from a NAND device
3334 -53 common/cmd_nand.c Bad usage of "nand" command
3335 53 common/cmd_nand.c correct usage of "nand" command
3336 -54 common/cmd_nand.c No boot device
3337 54 common/cmd_nand.c boot device found
3338 -55 common/cmd_nand.c Unknown Chip ID on boot device
3339 55 common/cmd_nand.c correct chip ID found, device available
3340 -56 common/cmd_nand.c Error reading Image Header on boot device
3341 56 common/cmd_nand.c reading Image Header from NAND device OK
3342 -57 common/cmd_nand.c Image header has bad magic number
3343 57 common/cmd_nand.c Image header has correct magic number
3344 -58 common/cmd_nand.c Error reading Image from NAND device
3345 58 common/cmd_nand.c reading Image from NAND device OK
3347 -60 common/env_common.c Environment has a bad CRC, using default
3349 64 net/eth.c starting with Ethernet configuration.
3350 -64 net/eth.c no Ethernet found.
3351 65 net/eth.c Ethernet found.
3353 -80 common/cmd_net.c usage wrong
3354 80 common/cmd_net.c before calling NetLoop()
3355 -81 common/cmd_net.c some error in NetLoop() occurred
3356 81 common/cmd_net.c NetLoop() back without error
3357 -82 common/cmd_net.c size == 0 (File with size 0 loaded)
3358 82 common/cmd_net.c trying automatic boot
3359 83 common/cmd_net.c running "source" command
3360 -83 common/cmd_net.c some error in automatic boot or "source" command
3361 84 common/cmd_net.c end without errors
3366 100 common/cmd_bootm.c Kernel FIT Image has correct format
3367 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format
3368 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration
3369 -101 common/cmd_bootm.c Can't get configuration for kernel subimage
3370 102 common/cmd_bootm.c Kernel unit name specified
3371 -103 common/cmd_bootm.c Can't get kernel subimage node offset
3372 103 common/cmd_bootm.c Found configuration node
3373 104 common/cmd_bootm.c Got kernel subimage node offset
3374 -104 common/cmd_bootm.c Kernel subimage hash verification failed
3375 105 common/cmd_bootm.c Kernel subimage hash verification OK
3376 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture
3377 106 common/cmd_bootm.c Architecture check OK
3378 -106 common/cmd_bootm.c Kernel subimage has wrong type
3379 107 common/cmd_bootm.c Kernel subimage type OK
3380 -107 common/cmd_bootm.c Can't get kernel subimage data/size
3381 108 common/cmd_bootm.c Got kernel subimage data/size
3382 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT)
3383 -109 common/cmd_bootm.c Can't get kernel subimage type
3384 -110 common/cmd_bootm.c Can't get kernel subimage comp
3385 -111 common/cmd_bootm.c Can't get kernel subimage os
3386 -112 common/cmd_bootm.c Can't get kernel subimage load address
3387 -113 common/cmd_bootm.c Image uncompress/copy overwrite error
3389 120 common/image.c Start initial ramdisk verification
3390 -120 common/image.c Ramdisk FIT image has incorrect format
3391 121 common/image.c Ramdisk FIT image has correct format
3392 122 common/image.c No ramdisk subimage unit name, using configuration
3393 -122 common/image.c Can't get configuration for ramdisk subimage
3394 123 common/image.c Ramdisk unit name specified
3395 -124 common/image.c Can't get ramdisk subimage node offset
3396 125 common/image.c Got ramdisk subimage node offset
3397 -125 common/image.c Ramdisk subimage hash verification failed
3398 126 common/image.c Ramdisk subimage hash verification OK
3399 -126 common/image.c Ramdisk subimage for unsupported architecture
3400 127 common/image.c Architecture check OK
3401 -127 common/image.c Can't get ramdisk subimage data/size
3402 128 common/image.c Got ramdisk subimage data/size
3403 129 common/image.c Can't get ramdisk load address
3404 -129 common/image.c Got ramdisk load address
3406 -130 common/cmd_doc.c Incorrect FIT image format
3407 131 common/cmd_doc.c FIT image format OK
3409 -140 common/cmd_ide.c Incorrect FIT image format
3410 141 common/cmd_ide.c FIT image format OK
3412 -150 common/cmd_nand.c Incorrect FIT image format
3413 151 common/cmd_nand.c FIT image format OK
3415 - legacy image format:
3416 CONFIG_IMAGE_FORMAT_LEGACY
3417 enables the legacy image format support in U-Boot.
3420 enabled if CONFIG_FIT_SIGNATURE is not defined.
3422 CONFIG_DISABLE_IMAGE_LEGACY
3423 disable the legacy image format
3425 This define is introduced, as the legacy image format is
3426 enabled per default for backward compatibility.
3428 - FIT image support:
3430 Enable support for the FIT uImage format.
3432 CONFIG_FIT_BEST_MATCH
3433 When no configuration is explicitly selected, default to the
3434 one whose fdt's compatibility field best matches that of
3435 U-Boot itself. A match is considered "best" if it matches the
3436 most specific compatibility entry of U-Boot's fdt's root node.
3437 The order of entries in the configuration's fdt is ignored.
3439 CONFIG_FIT_SIGNATURE
3440 This option enables signature verification of FIT uImages,
3441 using a hash signed and verified using RSA. If
3442 CONFIG_SHA_PROG_HW_ACCEL is defined, i.e support for progressive
3443 hashing is available using hardware, RSA library will use it.
3444 See doc/uImage.FIT/signature.txt for more details.
3446 WARNING: When relying on signed FIT images with required
3447 signature check the legacy image format is default
3448 disabled. If a board need legacy image format support
3449 enable this through CONFIG_IMAGE_FORMAT_LEGACY
3451 CONFIG_FIT_DISABLE_SHA256
3452 Supporting SHA256 hashes has quite an impact on binary size.
3453 For constrained systems sha256 hash support can be disabled
3456 - Standalone program support:
3457 CONFIG_STANDALONE_LOAD_ADDR
3459 This option defines a board specific value for the
3460 address where standalone program gets loaded, thus
3461 overwriting the architecture dependent default
3464 - Frame Buffer Address:
3467 Define CONFIG_FB_ADDR if you want to use specific
3468 address for frame buffer. This is typically the case
3469 when using a graphics controller has separate video
3470 memory. U-Boot will then place the frame buffer at
3471 the given address instead of dynamically reserving it
3472 in system RAM by calling lcd_setmem(), which grabs
3473 the memory for the frame buffer depending on the
3474 configured panel size.
3476 Please see board_init_f function.
3478 - Automatic software updates via TFTP server
3480 CONFIG_UPDATE_TFTP_CNT_MAX
3481 CONFIG_UPDATE_TFTP_MSEC_MAX
3483 These options enable and control the auto-update feature;
3484 for a more detailed description refer to doc/README.update.
3486 - MTD Support (mtdparts command, UBI support)
3489 Adds the MTD device infrastructure from the Linux kernel.
3490 Needed for mtdparts command support.
3492 CONFIG_MTD_PARTITIONS
3494 Adds the MTD partitioning infrastructure from the Linux
3495 kernel. Needed for UBI support.
3500 Adds commands for interacting with MTD partitions formatted
3501 with the UBI flash translation layer
3503 Requires also defining CONFIG_RBTREE
3505 CONFIG_UBI_SILENCE_MSG
3507 Make the verbose messages from UBI stop printing. This leaves
3508 warnings and errors enabled.
3511 CONFIG_MTD_UBI_WL_THRESHOLD
3512 This parameter defines the maximum difference between the highest
3513 erase counter value and the lowest erase counter value of eraseblocks
3514 of UBI devices. When this threshold is exceeded, UBI starts performing
3515 wear leveling by means of moving data from eraseblock with low erase
3516 counter to eraseblocks with high erase counter.
3518 The default value should be OK for SLC NAND flashes, NOR flashes and
3519 other flashes which have eraseblock life-cycle 100000 or more.
3520 However, in case of MLC NAND flashes which typically have eraseblock
3521 life-cycle less than 10000, the threshold should be lessened (e.g.,
3522 to 128 or 256, although it does not have to be power of 2).
3526 CONFIG_MTD_UBI_BEB_LIMIT
3527 This option specifies the maximum bad physical eraseblocks UBI
3528 expects on the MTD device (per 1024 eraseblocks). If the
3529 underlying flash does not admit of bad eraseblocks (e.g. NOR
3530 flash), this value is ignored.
3532 NAND datasheets often specify the minimum and maximum NVM
3533 (Number of Valid Blocks) for the flashes' endurance lifetime.
3534 The maximum expected bad eraseblocks per 1024 eraseblocks
3535 then can be calculated as "1024 * (1 - MinNVB / MaxNVB)",
3536 which gives 20 for most NANDs (MaxNVB is basically the total
3537 count of eraseblocks on the chip).
3539 To put it differently, if this value is 20, UBI will try to
3540 reserve about 1.9% of physical eraseblocks for bad blocks
3541 handling. And that will be 1.9% of eraseblocks on the entire
3542 NAND chip, not just the MTD partition UBI attaches. This means
3543 that if you have, say, a NAND flash chip admits maximum 40 bad
3544 eraseblocks, and it is split on two MTD partitions of the same
3545 size, UBI will reserve 40 eraseblocks when attaching a
3550 CONFIG_MTD_UBI_FASTMAP
3551 Fastmap is a mechanism which allows attaching an UBI device
3552 in nearly constant time. Instead of scanning the whole MTD device it
3553 only has to locate a checkpoint (called fastmap) on the device.
3554 The on-flash fastmap contains all information needed to attach
3555 the device. Using fastmap makes only sense on large devices where
3556 attaching by scanning takes long. UBI will not automatically install
3557 a fastmap on old images, but you can set the UBI parameter
3558 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT to 1 if you want so. Please note
3559 that fastmap-enabled images are still usable with UBI implementations
3560 without fastmap support. On typical flash devices the whole fastmap
3561 fits into one PEB. UBI will reserve PEBs to hold two fastmaps.
3563 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT
3564 Set this parameter to enable fastmap automatically on images
3571 Adds commands for interacting with UBI volumes formatted as
3572 UBIFS. UBIFS is read-only in u-boot.
3574 Requires UBI support as well as CONFIG_LZO
3576 CONFIG_UBIFS_SILENCE_MSG
3578 Make the verbose messages from UBIFS stop printing. This leaves
3579 warnings and errors enabled.
3583 Enable building of SPL globally.
3586 LDSCRIPT for linking the SPL binary.
3588 CONFIG_SPL_MAX_FOOTPRINT
3589 Maximum size in memory allocated to the SPL, BSS included.
3590 When defined, the linker checks that the actual memory
3591 used by SPL from _start to __bss_end does not exceed it.
3592 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
3593 must not be both defined at the same time.
3596 Maximum size of the SPL image (text, data, rodata, and
3597 linker lists sections), BSS excluded.
3598 When defined, the linker checks that the actual size does
3601 CONFIG_SPL_TEXT_BASE
3602 TEXT_BASE for linking the SPL binary.
3604 CONFIG_SPL_RELOC_TEXT_BASE
3605 Address to relocate to. If unspecified, this is equal to
3606 CONFIG_SPL_TEXT_BASE (i.e. no relocation is done).
3608 CONFIG_SPL_BSS_START_ADDR
3609 Link address for the BSS within the SPL binary.
3611 CONFIG_SPL_BSS_MAX_SIZE
3612 Maximum size in memory allocated to the SPL BSS.
3613 When defined, the linker checks that the actual memory used
3614 by SPL from __bss_start to __bss_end does not exceed it.
3615 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
3616 must not be both defined at the same time.
3619 Adress of the start of the stack SPL will use
3621 CONFIG_SPL_PANIC_ON_RAW_IMAGE
3622 When defined, SPL will panic() if the image it has
3623 loaded does not have a signature.
3624 Defining this is useful when code which loads images
3625 in SPL cannot guarantee that absolutely all read errors
3627 An example is the LPC32XX MLC NAND driver, which will
3628 consider that a completely unreadable NAND block is bad,
3629 and thus should be skipped silently.
3631 CONFIG_SPL_RELOC_STACK
3632 Adress of the start of the stack SPL will use after
3633 relocation. If unspecified, this is equal to
3636 CONFIG_SYS_SPL_MALLOC_START
3637 Starting address of the malloc pool used in SPL.
3639 CONFIG_SYS_SPL_MALLOC_SIZE
3640 The size of the malloc pool used in SPL.
3642 CONFIG_SPL_FRAMEWORK
3643 Enable the SPL framework under common/. This framework
3644 supports MMC, NAND and YMODEM loading of U-Boot and NAND
3645 NAND loading of the Linux Kernel.
3648 Enable booting directly to an OS from SPL.
3649 See also: doc/README.falcon
3651 CONFIG_SPL_DISPLAY_PRINT
3652 For ARM, enable an optional function to print more information
3653 about the running system.
3655 CONFIG_SPL_INIT_MINIMAL
3656 Arch init code should be built for a very small image
3658 CONFIG_SPL_LIBCOMMON_SUPPORT
3659 Support for common/libcommon.o in SPL binary
3661 CONFIG_SPL_LIBDISK_SUPPORT
3662 Support for disk/libdisk.o in SPL binary
3664 CONFIG_SPL_I2C_SUPPORT
3665 Support for drivers/i2c/libi2c.o in SPL binary
3667 CONFIG_SPL_GPIO_SUPPORT
3668 Support for drivers/gpio/libgpio.o in SPL binary
3670 CONFIG_SPL_MMC_SUPPORT
3671 Support for drivers/mmc/libmmc.o in SPL binary
3673 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_SECTOR,
3674 CONFIG_SYS_U_BOOT_MAX_SIZE_SECTORS,
3675 Address and partition on the MMC to load U-Boot from
3676 when the MMC is being used in raw mode.
3678 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_PARTITION
3679 Partition on the MMC to load U-Boot from when the MMC is being
3682 CONFIG_SYS_MMCSD_RAW_MODE_KERNEL_SECTOR
3683 Sector to load kernel uImage from when MMC is being
3684 used in raw mode (for Falcon mode)
3686 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTOR,
3687 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTORS
3688 Sector and number of sectors to load kernel argument
3689 parameters from when MMC is being used in raw mode
3692 CONFIG_SYS_MMCSD_FS_BOOT_PARTITION
3693 Partition on the MMC to load U-Boot from when the MMC is being
3696 CONFIG_SPL_FAT_SUPPORT
3697 Support for fs/fat/libfat.o in SPL binary
3699 CONFIG_SPL_EXT_SUPPORT
3700 Support for EXT filesystem in SPL binary
3702 CONFIG_SPL_FS_LOAD_PAYLOAD_NAME
3703 Filename to read to load U-Boot when reading from filesystem
3705 CONFIG_SPL_FS_LOAD_KERNEL_NAME
3706 Filename to read to load kernel uImage when reading
3707 from filesystem (for Falcon mode)
3709 CONFIG_SPL_FS_LOAD_ARGS_NAME
3710 Filename to read to load kernel argument parameters
3711 when reading from filesystem (for Falcon mode)
3713 CONFIG_SPL_MPC83XX_WAIT_FOR_NAND
3714 Set this for NAND SPL on PPC mpc83xx targets, so that
3715 start.S waits for the rest of the SPL to load before
3716 continuing (the hardware starts execution after just
3717 loading the first page rather than the full 4K).
3719 CONFIG_SPL_SKIP_RELOCATE
3720 Avoid SPL relocation
3722 CONFIG_SPL_NAND_BASE
3723 Include nand_base.c in the SPL. Requires
3724 CONFIG_SPL_NAND_DRIVERS.
3726 CONFIG_SPL_NAND_DRIVERS
3727 SPL uses normal NAND drivers, not minimal drivers.
3730 Include standard software ECC in the SPL
3732 CONFIG_SPL_NAND_SIMPLE
3733 Support for NAND boot using simple NAND drivers that
3734 expose the cmd_ctrl() interface.
3736 CONFIG_SPL_MTD_SUPPORT
3737 Support for the MTD subsystem within SPL. Useful for
3738 environment on NAND support within SPL.
3740 CONFIG_SPL_NAND_RAW_ONLY
3741 Support to boot only raw u-boot.bin images. Use this only
3742 if you need to save space.
3744 CONFIG_SPL_MPC8XXX_INIT_DDR_SUPPORT
3745 Set for the SPL on PPC mpc8xxx targets, support for
3746 drivers/ddr/fsl/libddr.o in SPL binary.
3748 CONFIG_SPL_COMMON_INIT_DDR
3749 Set for common ddr init with serial presence detect in
3752 CONFIG_SYS_NAND_5_ADDR_CYCLE, CONFIG_SYS_NAND_PAGE_COUNT,
3753 CONFIG_SYS_NAND_PAGE_SIZE, CONFIG_SYS_NAND_OOBSIZE,
3754 CONFIG_SYS_NAND_BLOCK_SIZE, CONFIG_SYS_NAND_BAD_BLOCK_POS,
3755 CONFIG_SYS_NAND_ECCPOS, CONFIG_SYS_NAND_ECCSIZE,
3756 CONFIG_SYS_NAND_ECCBYTES
3757 Defines the size and behavior of the NAND that SPL uses
3760 CONFIG_SPL_NAND_BOOT
3761 Add support NAND boot
3763 CONFIG_SYS_NAND_U_BOOT_OFFS
3764 Location in NAND to read U-Boot from
3766 CONFIG_SYS_NAND_U_BOOT_DST
3767 Location in memory to load U-Boot to
3769 CONFIG_SYS_NAND_U_BOOT_SIZE
3770 Size of image to load
3772 CONFIG_SYS_NAND_U_BOOT_START
3773 Entry point in loaded image to jump to
3775 CONFIG_SYS_NAND_HW_ECC_OOBFIRST
3776 Define this if you need to first read the OOB and then the
3777 data. This is used, for example, on davinci platforms.
3779 CONFIG_SPL_OMAP3_ID_NAND
3780 Support for an OMAP3-specific set of functions to return the
3781 ID and MFR of the first attached NAND chip, if present.
3783 CONFIG_SPL_SERIAL_SUPPORT
3784 Support for drivers/serial/libserial.o in SPL binary
3786 CONFIG_SPL_SPI_FLASH_SUPPORT
3787 Support for drivers/mtd/spi/libspi_flash.o in SPL binary
3789 CONFIG_SPL_SPI_SUPPORT
3790 Support for drivers/spi/libspi.o in SPL binary
3792 CONFIG_SPL_RAM_DEVICE
3793 Support for running image already present in ram, in SPL binary
3795 CONFIG_SPL_LIBGENERIC_SUPPORT
3796 Support for lib/libgeneric.o in SPL binary
3798 CONFIG_SPL_ENV_SUPPORT
3799 Support for the environment operating in SPL binary
3801 CONFIG_SPL_NET_SUPPORT
3802 Support for the net/libnet.o in SPL binary.
3803 It conflicts with SPL env from storage medium specified by
3804 CONFIG_ENV_IS_xxx but CONFIG_ENV_IS_NOWHERE
3807 Image offset to which the SPL should be padded before appending
3808 the SPL payload. By default, this is defined as
3809 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3810 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3811 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3814 Final target image containing SPL and payload. Some SPLs
3815 use an arch-specific makefile fragment instead, for
3816 example if more than one image needs to be produced.
3818 CONFIG_FIT_SPL_PRINT
3819 Printing information about a FIT image adds quite a bit of
3820 code to SPL. So this is normally disabled in SPL. Use this
3821 option to re-enable it. This will affect the output of the
3822 bootm command when booting a FIT image.
3826 Enable building of TPL globally.
3829 Image offset to which the TPL should be padded before appending
3830 the TPL payload. By default, this is defined as
3831 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3832 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3833 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3838 [so far only for SMDK2400 boards]
3840 - Modem support enable:
3841 CONFIG_MODEM_SUPPORT
3843 - RTS/CTS Flow control enable:
3846 - Modem debug support:
3847 CONFIG_MODEM_SUPPORT_DEBUG
3849 Enables debugging stuff (char screen[1024], dbg())
3850 for modem support. Useful only with BDI2000.
3852 - Interrupt support (PPC):
3854 There are common interrupt_init() and timer_interrupt()
3855 for all PPC archs. interrupt_init() calls interrupt_init_cpu()
3856 for CPU specific initialization. interrupt_init_cpu()
3857 should set decrementer_count to appropriate value. If
3858 CPU resets decrementer automatically after interrupt
3859 (ppc4xx) it should set decrementer_count to zero.
3860 timer_interrupt() calls timer_interrupt_cpu() for CPU
3861 specific handling. If board has watchdog / status_led
3862 / other_activity_monitor it works automatically from
3863 general timer_interrupt().
3867 In the target system modem support is enabled when a
3868 specific key (key combination) is pressed during
3869 power-on. Otherwise U-Boot will boot normally
3870 (autoboot). The key_pressed() function is called from
3871 board_init(). Currently key_pressed() is a dummy
3872 function, returning 1 and thus enabling modem
3875 If there are no modem init strings in the
3876 environment, U-Boot proceed to autoboot; the
3877 previous output (banner, info printfs) will be
3880 See also: doc/README.Modem
3882 Board initialization settings:
3883 ------------------------------
3885 During Initialization u-boot calls a number of board specific functions
3886 to allow the preparation of board specific prerequisites, e.g. pin setup
3887 before drivers are initialized. To enable these callbacks the
3888 following configuration macros have to be defined. Currently this is
3889 architecture specific, so please check arch/your_architecture/lib/board.c
3890 typically in board_init_f() and board_init_r().
3892 - CONFIG_BOARD_EARLY_INIT_F: Call board_early_init_f()
3893 - CONFIG_BOARD_EARLY_INIT_R: Call board_early_init_r()
3894 - CONFIG_BOARD_LATE_INIT: Call board_late_init()
3895 - CONFIG_BOARD_POSTCLK_INIT: Call board_postclk_init()
3897 Configuration Settings:
3898 -----------------------
3900 - CONFIG_SYS_SUPPORT_64BIT_DATA: Defined automatically if compiled as 64-bit.
3901 Optionally it can be defined to support 64-bit memory commands.
3903 - CONFIG_SYS_LONGHELP: Defined when you want long help messages included;
3904 undefine this when you're short of memory.
3906 - CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default
3907 width of the commands listed in the 'help' command output.
3909 - CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to
3910 prompt for user input.
3912 - CONFIG_SYS_CBSIZE: Buffer size for input from the Console
3914 - CONFIG_SYS_PBSIZE: Buffer size for Console output
3916 - CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands
3918 - CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to
3919 the application (usually a Linux kernel) when it is
3922 - CONFIG_SYS_BAUDRATE_TABLE:
3923 List of legal baudrate settings for this board.
3925 - CONFIG_SYS_CONSOLE_INFO_QUIET
3926 Suppress display of console information at boot.
3928 - CONFIG_SYS_CONSOLE_IS_IN_ENV
3929 If the board specific function
3930 extern int overwrite_console (void);
3931 returns 1, the stdin, stderr and stdout are switched to the
3932 serial port, else the settings in the environment are used.
3934 - CONFIG_SYS_CONSOLE_OVERWRITE_ROUTINE
3935 Enable the call to overwrite_console().
3937 - CONFIG_SYS_CONSOLE_ENV_OVERWRITE
3938 Enable overwrite of previous console environment settings.
3940 - CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END:
3941 Begin and End addresses of the area used by the
3944 - CONFIG_SYS_ALT_MEMTEST:
3945 Enable an alternate, more extensive memory test.
3947 - CONFIG_SYS_MEMTEST_SCRATCH:
3948 Scratch address used by the alternate memory test
3949 You only need to set this if address zero isn't writeable
3951 - CONFIG_SYS_MEM_TOP_HIDE (PPC only):
3952 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header,
3953 this specified memory area will get subtracted from the top
3954 (end) of RAM and won't get "touched" at all by U-Boot. By
3955 fixing up gd->ram_size the Linux kernel should gets passed
3956 the now "corrected" memory size and won't touch it either.
3957 This should work for arch/ppc and arch/powerpc. Only Linux
3958 board ports in arch/powerpc with bootwrapper support that
3959 recalculate the memory size from the SDRAM controller setup
3960 will have to get fixed in Linux additionally.
3962 This option can be used as a workaround for the 440EPx/GRx
3963 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't
3966 WARNING: Please make sure that this value is a multiple of
3967 the Linux page size (normally 4k). If this is not the case,
3968 then the end address of the Linux memory will be located at a
3969 non page size aligned address and this could cause major
3972 - CONFIG_SYS_LOADS_BAUD_CHANGE:
3973 Enable temporary baudrate change while serial download
3975 - CONFIG_SYS_SDRAM_BASE:
3976 Physical start address of SDRAM. _Must_ be 0 here.
3978 - CONFIG_SYS_MBIO_BASE:
3979 Physical start address of Motherboard I/O (if using a
3982 - CONFIG_SYS_FLASH_BASE:
3983 Physical start address of Flash memory.
3985 - CONFIG_SYS_MONITOR_BASE:
3986 Physical start address of boot monitor code (set by
3987 make config files to be same as the text base address
3988 (CONFIG_SYS_TEXT_BASE) used when linking) - same as
3989 CONFIG_SYS_FLASH_BASE when booting from flash.
3991 - CONFIG_SYS_MONITOR_LEN:
3992 Size of memory reserved for monitor code, used to
3993 determine _at_compile_time_ (!) if the environment is
3994 embedded within the U-Boot image, or in a separate
3997 - CONFIG_SYS_MALLOC_LEN:
3998 Size of DRAM reserved for malloc() use.
4000 - CONFIG_SYS_MALLOC_F_LEN
4001 Size of the malloc() pool for use before relocation. If
4002 this is defined, then a very simple malloc() implementation
4003 will become available before relocation. The address is just
4004 below the global data, and the stack is moved down to make
4007 This feature allocates regions with increasing addresses
4008 within the region. calloc() is supported, but realloc()
4009 is not available. free() is supported but does nothing.
4010 The memory will be freed (or in fact just forgotten) when
4011 U-Boot relocates itself.
4013 Pre-relocation malloc() is only supported on ARM and sandbox
4014 at present but is fairly easy to enable for other archs.
4016 - CONFIG_SYS_MALLOC_SIMPLE
4017 Provides a simple and small malloc() and calloc() for those
4018 boards which do not use the full malloc in SPL (which is
4019 enabled with CONFIG_SYS_SPL_MALLOC_START).
4021 - CONFIG_SYS_NONCACHED_MEMORY:
4022 Size of non-cached memory area. This area of memory will be
4023 typically located right below the malloc() area and mapped
4024 uncached in the MMU. This is useful for drivers that would
4025 otherwise require a lot of explicit cache maintenance. For
4026 some drivers it's also impossible to properly maintain the
4027 cache. For example if the regions that need to be flushed
4028 are not a multiple of the cache-line size, *and* padding
4029 cannot be allocated between the regions to align them (i.e.
4030 if the HW requires a contiguous array of regions, and the
4031 size of each region is not cache-aligned), then a flush of
4032 one region may result in overwriting data that hardware has
4033 written to another region in the same cache-line. This can
4034 happen for example in network drivers where descriptors for
4035 buffers are typically smaller than the CPU cache-line (e.g.
4036 16 bytes vs. 32 or 64 bytes).
4038 Non-cached memory is only supported on 32-bit ARM at present.
4040 - CONFIG_SYS_BOOTM_LEN:
4041 Normally compressed uImages are limited to an
4042 uncompressed size of 8 MBytes. If this is not enough,
4043 you can define CONFIG_SYS_BOOTM_LEN in your board config file
4044 to adjust this setting to your needs.
4046 - CONFIG_SYS_BOOTMAPSZ:
4047 Maximum size of memory mapped by the startup code of
4048 the Linux kernel; all data that must be processed by
4049 the Linux kernel (bd_info, boot arguments, FDT blob if
4050 used) must be put below this limit, unless "bootm_low"
4051 environment variable is defined and non-zero. In such case
4052 all data for the Linux kernel must be between "bootm_low"
4053 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ. The environment
4054 variable "bootm_mapsize" will override the value of
4055 CONFIG_SYS_BOOTMAPSZ. If CONFIG_SYS_BOOTMAPSZ is undefined,
4056 then the value in "bootm_size" will be used instead.
4058 - CONFIG_SYS_BOOT_RAMDISK_HIGH:
4059 Enable initrd_high functionality. If defined then the
4060 initrd_high feature is enabled and the bootm ramdisk subcommand
4063 - CONFIG_SYS_BOOT_GET_CMDLINE:
4064 Enables allocating and saving kernel cmdline in space between
4065 "bootm_low" and "bootm_low" + BOOTMAPSZ.
4067 - CONFIG_SYS_BOOT_GET_KBD:
4068 Enables allocating and saving a kernel copy of the bd_info in
4069 space between "bootm_low" and "bootm_low" + BOOTMAPSZ.
4071 - CONFIG_SYS_MAX_FLASH_BANKS:
4072 Max number of Flash memory banks
4074 - CONFIG_SYS_MAX_FLASH_SECT:
4075 Max number of sectors on a Flash chip
4077 - CONFIG_SYS_FLASH_ERASE_TOUT:
4078 Timeout for Flash erase operations (in ms)
4080 - CONFIG_SYS_FLASH_WRITE_TOUT:
4081 Timeout for Flash write operations (in ms)
4083 - CONFIG_SYS_FLASH_LOCK_TOUT
4084 Timeout for Flash set sector lock bit operation (in ms)
4086 - CONFIG_SYS_FLASH_UNLOCK_TOUT
4087 Timeout for Flash clear lock bits operation (in ms)
4089 - CONFIG_SYS_FLASH_PROTECTION
4090 If defined, hardware flash sectors protection is used
4091 instead of U-Boot software protection.
4093 - CONFIG_SYS_DIRECT_FLASH_TFTP:
4095 Enable TFTP transfers directly to flash memory;
4096 without this option such a download has to be
4097 performed in two steps: (1) download to RAM, and (2)
4098 copy from RAM to flash.
4100 The two-step approach is usually more reliable, since
4101 you can check if the download worked before you erase
4102 the flash, but in some situations (when system RAM is
4103 too limited to allow for a temporary copy of the
4104 downloaded image) this option may be very useful.
4106 - CONFIG_SYS_FLASH_CFI:
4107 Define if the flash driver uses extra elements in the
4108 common flash structure for storing flash geometry.
4110 - CONFIG_FLASH_CFI_DRIVER
4111 This option also enables the building of the cfi_flash driver
4112 in the drivers directory
4114 - CONFIG_FLASH_CFI_MTD
4115 This option enables the building of the cfi_mtd driver
4116 in the drivers directory. The driver exports CFI flash
4119 - CONFIG_SYS_FLASH_USE_BUFFER_WRITE
4120 Use buffered writes to flash.
4122 - CONFIG_FLASH_SPANSION_S29WS_N
4123 s29ws-n MirrorBit flash has non-standard addresses for buffered
4126 - CONFIG_SYS_FLASH_QUIET_TEST
4127 If this option is defined, the common CFI flash doesn't
4128 print it's warning upon not recognized FLASH banks. This
4129 is useful, if some of the configured banks are only
4130 optionally available.
4132 - CONFIG_FLASH_SHOW_PROGRESS
4133 If defined (must be an integer), print out countdown
4134 digits and dots. Recommended value: 45 (9..1) for 80
4135 column displays, 15 (3..1) for 40 column displays.
4137 - CONFIG_FLASH_VERIFY
4138 If defined, the content of the flash (destination) is compared
4139 against the source after the write operation. An error message
4140 will be printed when the contents are not identical.
4141 Please note that this option is useless in nearly all cases,
4142 since such flash programming errors usually are detected earlier
4143 while unprotecting/erasing/programming. Please only enable
4144 this option if you really know what you are doing.
4146 - CONFIG_SYS_RX_ETH_BUFFER:
4147 Defines the number of Ethernet receive buffers. On some
4148 Ethernet controllers it is recommended to set this value
4149 to 8 or even higher (EEPRO100 or 405 EMAC), since all
4150 buffers can be full shortly after enabling the interface
4151 on high Ethernet traffic.
4152 Defaults to 4 if not defined.
4154 - CONFIG_ENV_MAX_ENTRIES
4156 Maximum number of entries in the hash table that is used
4157 internally to store the environment settings. The default
4158 setting is supposed to be generous and should work in most
4159 cases. This setting can be used to tune behaviour; see
4160 lib/hashtable.c for details.
4162 - CONFIG_ENV_FLAGS_LIST_DEFAULT
4163 - CONFIG_ENV_FLAGS_LIST_STATIC
4164 Enable validation of the values given to environment variables when
4165 calling env set. Variables can be restricted to only decimal,
4166 hexadecimal, or boolean. If CONFIG_CMD_NET is also defined,
4167 the variables can also be restricted to IP address or MAC address.
4169 The format of the list is:
4170 type_attribute = [s|d|x|b|i|m]
4171 access_attribute = [a|r|o|c]
4172 attributes = type_attribute[access_attribute]
4173 entry = variable_name[:attributes]
4176 The type attributes are:
4177 s - String (default)
4180 b - Boolean ([1yYtT|0nNfF])
4184 The access attributes are:
4190 - CONFIG_ENV_FLAGS_LIST_DEFAULT
4191 Define this to a list (string) to define the ".flags"
4192 environment variable in the default or embedded environment.
4194 - CONFIG_ENV_FLAGS_LIST_STATIC
4195 Define this to a list (string) to define validation that
4196 should be done if an entry is not found in the ".flags"
4197 environment variable. To override a setting in the static
4198 list, simply add an entry for the same variable name to the
4201 - CONFIG_ENV_ACCESS_IGNORE_FORCE
4202 If defined, don't allow the -f switch to env set override variable
4205 - CONFIG_SYS_GENERIC_BOARD
4206 This selects the architecture-generic board system instead of the
4207 architecture-specific board files. It is intended to move boards
4208 to this new framework over time. Defining this will disable the
4209 arch/foo/lib/board.c file and use common/board_f.c and
4210 common/board_r.c instead. To use this option your architecture
4211 must support it (i.e. must select HAVE_GENERIC_BOARD in arch/Kconfig).
4212 If you find problems enabling this option on your board please report
4213 the problem and send patches!
4215 - CONFIG_OMAP_PLATFORM_RESET_TIME_MAX_USEC (OMAP only)
4216 This is set by OMAP boards for the max time that reset should
4217 be asserted. See doc/README.omap-reset-time for details on how
4218 the value can be calculated on a given board.
4221 If stdint.h is available with your toolchain you can define this
4222 option to enable it. You can provide option 'USE_STDINT=1' when
4223 building U-Boot to enable this.
4225 The following definitions that deal with the placement and management
4226 of environment data (variable area); in general, we support the
4227 following configurations:
4229 - CONFIG_BUILD_ENVCRC:
4231 Builds up envcrc with the target environment so that external utils
4232 may easily extract it and embed it in final U-Boot images.
4234 - CONFIG_ENV_IS_IN_FLASH:
4236 Define this if the environment is in flash memory.
4238 a) The environment occupies one whole flash sector, which is
4239 "embedded" in the text segment with the U-Boot code. This
4240 happens usually with "bottom boot sector" or "top boot
4241 sector" type flash chips, which have several smaller
4242 sectors at the start or the end. For instance, such a
4243 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In
4244 such a case you would place the environment in one of the
4245 4 kB sectors - with U-Boot code before and after it. With
4246 "top boot sector" type flash chips, you would put the
4247 environment in one of the last sectors, leaving a gap
4248 between U-Boot and the environment.
4250 - CONFIG_ENV_OFFSET:
4252 Offset of environment data (variable area) to the
4253 beginning of flash memory; for instance, with bottom boot
4254 type flash chips the second sector can be used: the offset
4255 for this sector is given here.
4257 CONFIG_ENV_OFFSET is used relative to CONFIG_SYS_FLASH_BASE.
4261 This is just another way to specify the start address of
4262 the flash sector containing the environment (instead of
4265 - CONFIG_ENV_SECT_SIZE:
4267 Size of the sector containing the environment.
4270 b) Sometimes flash chips have few, equal sized, BIG sectors.
4271 In such a case you don't want to spend a whole sector for
4276 If you use this in combination with CONFIG_ENV_IS_IN_FLASH
4277 and CONFIG_ENV_SECT_SIZE, you can specify to use only a part
4278 of this flash sector for the environment. This saves
4279 memory for the RAM copy of the environment.
4281 It may also save flash memory if you decide to use this
4282 when your environment is "embedded" within U-Boot code,
4283 since then the remainder of the flash sector could be used
4284 for U-Boot code. It should be pointed out that this is
4285 STRONGLY DISCOURAGED from a robustness point of view:
4286 updating the environment in flash makes it always
4287 necessary to erase the WHOLE sector. If something goes
4288 wrong before the contents has been restored from a copy in
4289 RAM, your target system will be dead.
4291 - CONFIG_ENV_ADDR_REDUND
4292 CONFIG_ENV_SIZE_REDUND
4294 These settings describe a second storage area used to hold
4295 a redundant copy of the environment data, so that there is
4296 a valid backup copy in case there is a power failure during
4297 a "saveenv" operation.
4299 BE CAREFUL! Any changes to the flash layout, and some changes to the
4300 source code will make it necessary to adapt <board>/u-boot.lds*
4304 - CONFIG_ENV_IS_IN_NVRAM:
4306 Define this if you have some non-volatile memory device
4307 (NVRAM, battery buffered SRAM) which you want to use for the
4313 These two #defines are used to determine the memory area you
4314 want to use for environment. It is assumed that this memory
4315 can just be read and written to, without any special
4318 BE CAREFUL! The first access to the environment happens quite early
4319 in U-Boot initialization (when we try to get the setting of for the
4320 console baudrate). You *MUST* have mapped your NVRAM area then, or
4323 Please note that even with NVRAM we still use a copy of the
4324 environment in RAM: we could work on NVRAM directly, but we want to
4325 keep settings there always unmodified except somebody uses "saveenv"
4326 to save the current settings.
4329 - CONFIG_ENV_IS_IN_EEPROM:
4331 Use this if you have an EEPROM or similar serial access
4332 device and a driver for it.
4334 - CONFIG_ENV_OFFSET:
4337 These two #defines specify the offset and size of the
4338 environment area within the total memory of your EEPROM.
4340 - CONFIG_SYS_I2C_EEPROM_ADDR:
4341 If defined, specified the chip address of the EEPROM device.
4342 The default address is zero.
4344 - CONFIG_SYS_I2C_EEPROM_BUS:
4345 If defined, specified the i2c bus of the EEPROM device.
4347 - CONFIG_SYS_EEPROM_PAGE_WRITE_BITS:
4348 If defined, the number of bits used to address bytes in a
4349 single page in the EEPROM device. A 64 byte page, for example
4350 would require six bits.
4352 - CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS:
4353 If defined, the number of milliseconds to delay between
4354 page writes. The default is zero milliseconds.
4356 - CONFIG_SYS_I2C_EEPROM_ADDR_LEN:
4357 The length in bytes of the EEPROM memory array address. Note
4358 that this is NOT the chip address length!
4360 - CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW:
4361 EEPROM chips that implement "address overflow" are ones
4362 like Catalyst 24WC04/08/16 which has 9/10/11 bits of
4363 address and the extra bits end up in the "chip address" bit
4364 slots. This makes a 24WC08 (1Kbyte) chip look like four 256
4367 Note that we consider the length of the address field to
4368 still be one byte because the extra address bits are hidden
4369 in the chip address.
4371 - CONFIG_SYS_EEPROM_SIZE:
4372 The size in bytes of the EEPROM device.
4374 - CONFIG_ENV_EEPROM_IS_ON_I2C
4375 define this, if you have I2C and SPI activated, and your
4376 EEPROM, which holds the environment, is on the I2C bus.
4378 - CONFIG_I2C_ENV_EEPROM_BUS
4379 if you have an Environment on an EEPROM reached over
4380 I2C muxes, you can define here, how to reach this
4381 EEPROM. For example:
4383 #define CONFIG_I2C_ENV_EEPROM_BUS 1
4385 EEPROM which holds the environment, is reached over
4386 a pca9547 i2c mux with address 0x70, channel 3.
4388 - CONFIG_ENV_IS_IN_DATAFLASH:
4390 Define this if you have a DataFlash memory device which you
4391 want to use for the environment.
4393 - CONFIG_ENV_OFFSET:
4397 These three #defines specify the offset and size of the
4398 environment area within the total memory of your DataFlash placed
4399 at the specified address.
4401 - CONFIG_ENV_IS_IN_SPI_FLASH:
4403 Define this if you have a SPI Flash memory device which you
4404 want to use for the environment.
4406 - CONFIG_ENV_OFFSET:
4409 These two #defines specify the offset and size of the
4410 environment area within the SPI Flash. CONFIG_ENV_OFFSET must be
4411 aligned to an erase sector boundary.
4413 - CONFIG_ENV_SECT_SIZE:
4415 Define the SPI flash's sector size.
4417 - CONFIG_ENV_OFFSET_REDUND (optional):
4419 This setting describes a second storage area of CONFIG_ENV_SIZE
4420 size used to hold a redundant copy of the environment data, so
4421 that there is a valid backup copy in case there is a power failure
4422 during a "saveenv" operation. CONFIG_ENV_OFFSET_RENDUND must be
4423 aligned to an erase sector boundary.
4425 - CONFIG_ENV_SPI_BUS (optional):
4426 - CONFIG_ENV_SPI_CS (optional):
4428 Define the SPI bus and chip select. If not defined they will be 0.
4430 - CONFIG_ENV_SPI_MAX_HZ (optional):
4432 Define the SPI max work clock. If not defined then use 1MHz.
4434 - CONFIG_ENV_SPI_MODE (optional):
4436 Define the SPI work mode. If not defined then use SPI_MODE_3.
4438 - CONFIG_ENV_IS_IN_REMOTE:
4440 Define this if you have a remote memory space which you
4441 want to use for the local device's environment.
4446 These two #defines specify the address and size of the
4447 environment area within the remote memory space. The
4448 local device can get the environment from remote memory
4449 space by SRIO or PCIE links.
4451 BE CAREFUL! For some special cases, the local device can not use
4452 "saveenv" command. For example, the local device will get the
4453 environment stored in a remote NOR flash by SRIO or PCIE link,
4454 but it can not erase, write this NOR flash by SRIO or PCIE interface.
4456 - CONFIG_ENV_IS_IN_NAND:
4458 Define this if you have a NAND device which you want to use
4459 for the environment.
4461 - CONFIG_ENV_OFFSET:
4464 These two #defines specify the offset and size of the environment
4465 area within the first NAND device. CONFIG_ENV_OFFSET must be
4466 aligned to an erase block boundary.
4468 - CONFIG_ENV_OFFSET_REDUND (optional):
4470 This setting describes a second storage area of CONFIG_ENV_SIZE
4471 size used to hold a redundant copy of the environment data, so
4472 that there is a valid backup copy in case there is a power failure
4473 during a "saveenv" operation. CONFIG_ENV_OFFSET_RENDUND must be
4474 aligned to an erase block boundary.
4476 - CONFIG_ENV_RANGE (optional):
4478 Specifies the length of the region in which the environment
4479 can be written. This should be a multiple of the NAND device's
4480 block size. Specifying a range with more erase blocks than
4481 are needed to hold CONFIG_ENV_SIZE allows bad blocks within
4482 the range to be avoided.
4484 - CONFIG_ENV_OFFSET_OOB (optional):
4486 Enables support for dynamically retrieving the offset of the
4487 environment from block zero's out-of-band data. The
4488 "nand env.oob" command can be used to record this offset.
4489 Currently, CONFIG_ENV_OFFSET_REDUND is not supported when
4490 using CONFIG_ENV_OFFSET_OOB.
4492 - CONFIG_NAND_ENV_DST
4494 Defines address in RAM to which the nand_spl code should copy the
4495 environment. If redundant environment is used, it will be copied to
4496 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE.
4498 - CONFIG_ENV_IS_IN_UBI:
4500 Define this if you have an UBI volume that you want to use for the
4501 environment. This has the benefit of wear-leveling the environment
4502 accesses, which is important on NAND.
4504 - CONFIG_ENV_UBI_PART:
4506 Define this to a string that is the mtd partition containing the UBI.
4508 - CONFIG_ENV_UBI_VOLUME:
4510 Define this to the name of the volume that you want to store the
4513 - CONFIG_ENV_UBI_VOLUME_REDUND:
4515 Define this to the name of another volume to store a second copy of
4516 the environment in. This will enable redundant environments in UBI.
4517 It is assumed that both volumes are in the same MTD partition.
4519 - CONFIG_UBI_SILENCE_MSG
4520 - CONFIG_UBIFS_SILENCE_MSG
4522 You will probably want to define these to avoid a really noisy system
4523 when storing the env in UBI.
4525 - CONFIG_ENV_IS_IN_FAT:
4526 Define this if you want to use the FAT file system for the environment.
4528 - FAT_ENV_INTERFACE:
4530 Define this to a string that is the name of the block device.
4532 - FAT_ENV_DEV_AND_PART:
4534 Define this to a string to specify the partition of the device. It can
4537 "D:P", "D:0", "D", "D:" or "D:auto" (D, P are integers. And P >= 1)
4538 - "D:P": device D partition P. Error occurs if device D has no
4541 - "D" or "D:": device D partition 1 if device D has partition
4542 table, or the whole device D if has no partition
4544 - "D:auto": first partition in device D with bootable flag set.
4545 If none, first valid partition in device D. If no
4546 partition table then means device D.
4550 It's a string of the FAT file name. This file use to store the
4554 This should be defined. Otherwise it cannot save the environment file.
4556 - CONFIG_ENV_IS_IN_MMC:
4558 Define this if you have an MMC device which you want to use for the
4561 - CONFIG_SYS_MMC_ENV_DEV:
4563 Specifies which MMC device the environment is stored in.
4565 - CONFIG_SYS_MMC_ENV_PART (optional):
4567 Specifies which MMC partition the environment is stored in. If not
4568 set, defaults to partition 0, the user area. Common values might be
4569 1 (first MMC boot partition), 2 (second MMC boot partition).
4571 - CONFIG_ENV_OFFSET:
4574 These two #defines specify the offset and size of the environment
4575 area within the specified MMC device.
4577 If offset is positive (the usual case), it is treated as relative to
4578 the start of the MMC partition. If offset is negative, it is treated
4579 as relative to the end of the MMC partition. This can be useful if
4580 your board may be fitted with different MMC devices, which have
4581 different sizes for the MMC partitions, and you always want the
4582 environment placed at the very end of the partition, to leave the
4583 maximum possible space before it, to store other data.
4585 These two values are in units of bytes, but must be aligned to an
4586 MMC sector boundary.
4588 - CONFIG_ENV_OFFSET_REDUND (optional):
4590 Specifies a second storage area, of CONFIG_ENV_SIZE size, used to
4591 hold a redundant copy of the environment data. This provides a
4592 valid backup copy in case the other copy is corrupted, e.g. due
4593 to a power failure during a "saveenv" operation.
4595 This value may also be positive or negative; this is handled in the
4596 same way as CONFIG_ENV_OFFSET.
4598 This value is also in units of bytes, but must also be aligned to
4599 an MMC sector boundary.
4601 - CONFIG_ENV_SIZE_REDUND (optional):
4603 This value need not be set, even when CONFIG_ENV_OFFSET_REDUND is
4604 set. If this value is set, it must be set to the same value as
4607 - CONFIG_SYS_SPI_INIT_OFFSET
4609 Defines offset to the initial SPI buffer area in DPRAM. The
4610 area is used at an early stage (ROM part) if the environment
4611 is configured to reside in the SPI EEPROM: We need a 520 byte
4612 scratch DPRAM area. It is used between the two initialization
4613 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems
4614 to be a good choice since it makes it far enough from the
4615 start of the data area as well as from the stack pointer.
4617 Please note that the environment is read-only until the monitor
4618 has been relocated to RAM and a RAM copy of the environment has been
4619 created; also, when using EEPROM you will have to use getenv_f()
4620 until then to read environment variables.
4622 The environment is protected by a CRC32 checksum. Before the monitor
4623 is relocated into RAM, as a result of a bad CRC you will be working
4624 with the compiled-in default environment - *silently*!!! [This is
4625 necessary, because the first environment variable we need is the
4626 "baudrate" setting for the console - if we have a bad CRC, we don't
4627 have any device yet where we could complain.]
4629 Note: once the monitor has been relocated, then it will complain if
4630 the default environment is used; a new CRC is computed as soon as you
4631 use the "saveenv" command to store a valid environment.
4633 - CONFIG_SYS_FAULT_ECHO_LINK_DOWN:
4634 Echo the inverted Ethernet link state to the fault LED.
4636 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR
4637 also needs to be defined.
4639 - CONFIG_SYS_FAULT_MII_ADDR:
4640 MII address of the PHY to check for the Ethernet link state.
4642 - CONFIG_NS16550_MIN_FUNCTIONS:
4643 Define this if you desire to only have use of the NS16550_init
4644 and NS16550_putc functions for the serial driver located at
4645 drivers/serial/ns16550.c. This option is useful for saving
4646 space for already greatly restricted images, including but not
4647 limited to NAND_SPL configurations.
4649 - CONFIG_DISPLAY_BOARDINFO
4650 Display information about the board that U-Boot is running on
4651 when U-Boot starts up. The board function checkboard() is called
4654 - CONFIG_DISPLAY_BOARDINFO_LATE
4655 Similar to the previous option, but display this information
4656 later, once stdio is running and output goes to the LCD, if
4659 - CONFIG_BOARD_SIZE_LIMIT:
4660 Maximum size of the U-Boot image. When defined, the
4661 build system checks that the actual size does not
4664 Low Level (hardware related) configuration options:
4665 ---------------------------------------------------
4667 - CONFIG_SYS_CACHELINE_SIZE:
4668 Cache Line Size of the CPU.
4670 - CONFIG_SYS_DEFAULT_IMMR:
4671 Default address of the IMMR after system reset.
4673 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU,
4674 and RPXsuper) to be able to adjust the position of
4675 the IMMR register after a reset.
4677 - CONFIG_SYS_CCSRBAR_DEFAULT:
4678 Default (power-on reset) physical address of CCSR on Freescale
4681 - CONFIG_SYS_CCSRBAR:
4682 Virtual address of CCSR. On a 32-bit build, this is typically
4683 the same value as CONFIG_SYS_CCSRBAR_DEFAULT.
4685 CONFIG_SYS_DEFAULT_IMMR must also be set to this value,
4686 for cross-platform code that uses that macro instead.
4688 - CONFIG_SYS_CCSRBAR_PHYS:
4689 Physical address of CCSR. CCSR can be relocated to a new
4690 physical address, if desired. In this case, this macro should
4691 be set to that address. Otherwise, it should be set to the
4692 same value as CONFIG_SYS_CCSRBAR_DEFAULT. For example, CCSR
4693 is typically relocated on 36-bit builds. It is recommended
4694 that this macro be defined via the _HIGH and _LOW macros:
4696 #define CONFIG_SYS_CCSRBAR_PHYS ((CONFIG_SYS_CCSRBAR_PHYS_HIGH
4697 * 1ull) << 32 | CONFIG_SYS_CCSRBAR_PHYS_LOW)
4699 - CONFIG_SYS_CCSRBAR_PHYS_HIGH:
4700 Bits 33-36 of CONFIG_SYS_CCSRBAR_PHYS. This value is typically
4701 either 0 (32-bit build) or 0xF (36-bit build). This macro is
4702 used in assembly code, so it must not contain typecasts or
4703 integer size suffixes (e.g. "ULL").
4705 - CONFIG_SYS_CCSRBAR_PHYS_LOW:
4706 Lower 32-bits of CONFIG_SYS_CCSRBAR_PHYS. This macro is
4707 used in assembly code, so it must not contain typecasts or
4708 integer size suffixes (e.g. "ULL").
4710 - CONFIG_SYS_CCSR_DO_NOT_RELOCATE:
4711 If this macro is defined, then CONFIG_SYS_CCSRBAR_PHYS will be
4712 forced to a value that ensures that CCSR is not relocated.
4714 - Floppy Disk Support:
4715 CONFIG_SYS_FDC_DRIVE_NUMBER
4717 the default drive number (default value 0)
4719 CONFIG_SYS_ISA_IO_STRIDE
4721 defines the spacing between FDC chipset registers
4724 CONFIG_SYS_ISA_IO_OFFSET
4726 defines the offset of register from address. It
4727 depends on which part of the data bus is connected to
4728 the FDC chipset. (default value 0)
4730 If CONFIG_SYS_ISA_IO_STRIDE CONFIG_SYS_ISA_IO_OFFSET and
4731 CONFIG_SYS_FDC_DRIVE_NUMBER are undefined, they take their
4734 if CONFIG_SYS_FDC_HW_INIT is defined, then the function
4735 fdc_hw_init() is called at the beginning of the FDC
4736 setup. fdc_hw_init() must be provided by the board
4737 source code. It is used to make hardware-dependent
4741 Most IDE controllers were designed to be connected with PCI
4742 interface. Only few of them were designed for AHB interface.
4743 When software is doing ATA command and data transfer to
4744 IDE devices through IDE-AHB controller, some additional
4745 registers accessing to these kind of IDE-AHB controller
4748 - CONFIG_SYS_IMMR: Physical address of the Internal Memory.
4749 DO NOT CHANGE unless you know exactly what you're
4750 doing! (11-4) [MPC8xx/82xx systems only]
4752 - CONFIG_SYS_INIT_RAM_ADDR:
4754 Start address of memory area that can be used for
4755 initial data and stack; please note that this must be
4756 writable memory that is working WITHOUT special
4757 initialization, i. e. you CANNOT use normal RAM which
4758 will become available only after programming the
4759 memory controller and running certain initialization
4762 U-Boot uses the following memory types:
4763 - MPC8xx and MPC8260: IMMR (internal memory of the CPU)
4764 - MPC824X: data cache
4765 - PPC4xx: data cache
4767 - CONFIG_SYS_GBL_DATA_OFFSET:
4769 Offset of the initial data structure in the memory
4770 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually
4771 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial
4772 data is located at the end of the available space
4773 (sometimes written as (CONFIG_SYS_INIT_RAM_SIZE -
4774 CONFIG_SYS_INIT_DATA_SIZE), and the initial stack is just
4775 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR +
4776 CONFIG_SYS_GBL_DATA_OFFSET) downward.
4779 On the MPC824X (or other systems that use the data
4780 cache for initial memory) the address chosen for
4781 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must
4782 point to an otherwise UNUSED address space between
4783 the top of RAM and the start of the PCI space.
4785 - CONFIG_SYS_SIUMCR: SIU Module Configuration (11-6)
4787 - CONFIG_SYS_SYPCR: System Protection Control (11-9)
4789 - CONFIG_SYS_TBSCR: Time Base Status and Control (11-26)
4791 - CONFIG_SYS_PISCR: Periodic Interrupt Status and Control (11-31)
4793 - CONFIG_SYS_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30)
4795 - CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27)
4797 - CONFIG_SYS_OR_TIMING_SDRAM:
4800 - CONFIG_SYS_MAMR_PTA:
4801 periodic timer for refresh
4803 - CONFIG_SYS_DER: Debug Event Register (37-47)
4805 - FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM,
4806 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP,
4807 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM,
4808 CONFIG_SYS_BR1_PRELIM:
4809 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
4811 - SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
4812 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM,
4813 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM:
4814 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
4816 - CONFIG_SYS_MAMR_PTA, CONFIG_SYS_MPTPR_2BK_4K, CONFIG_SYS_MPTPR_1BK_4K, CONFIG_SYS_MPTPR_2BK_8K,
4817 CONFIG_SYS_MPTPR_1BK_8K, CONFIG_SYS_MAMR_8COL, CONFIG_SYS_MAMR_9COL:
4818 Machine Mode Register and Memory Periodic Timer
4819 Prescaler definitions (SDRAM timing)
4821 - CONFIG_SYS_I2C_UCODE_PATCH, CONFIG_SYS_I2C_DPMEM_OFFSET [0x1FC0]:
4822 enable I2C microcode relocation patch (MPC8xx);
4823 define relocation offset in DPRAM [DSP2]
4825 - CONFIG_SYS_SMC_UCODE_PATCH, CONFIG_SYS_SMC_DPMEM_OFFSET [0x1FC0]:
4826 enable SMC microcode relocation patch (MPC8xx);
4827 define relocation offset in DPRAM [SMC1]
4829 - CONFIG_SYS_SPI_UCODE_PATCH, CONFIG_SYS_SPI_DPMEM_OFFSET [0x1FC0]:
4830 enable SPI microcode relocation patch (MPC8xx);
4831 define relocation offset in DPRAM [SCC4]
4833 - CONFIG_SYS_USE_OSCCLK:
4834 Use OSCM clock mode on MBX8xx board. Be careful,
4835 wrong setting might damage your board. Read
4836 doc/README.MBX before setting this variable!
4838 - CONFIG_SYS_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only)
4839 Offset of the bootmode word in DPRAM used by post
4840 (Power On Self Tests). This definition overrides
4841 #define'd default value in commproc.h resp.
4844 - CONFIG_SYS_PCI_SLV_MEM_LOCAL, CONFIG_SYS_PCI_SLV_MEM_BUS, CONFIG_SYS_PICMR0_MASK_ATTRIB,
4845 CONFIG_SYS_PCI_MSTR0_LOCAL, CONFIG_SYS_PCIMSK0_MASK, CONFIG_SYS_PCI_MSTR1_LOCAL,
4846 CONFIG_SYS_PCIMSK1_MASK, CONFIG_SYS_PCI_MSTR_MEM_LOCAL, CONFIG_SYS_PCI_MSTR_MEM_BUS,
4847 CONFIG_SYS_CPU_PCI_MEM_START, CONFIG_SYS_PCI_MSTR_MEM_SIZE, CONFIG_SYS_POCMR0_MASK_ATTRIB,
4848 CONFIG_SYS_PCI_MSTR_MEMIO_LOCAL, CONFIG_SYS_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START,
4849 CONFIG_SYS_PCI_MSTR_MEMIO_SIZE, CONFIG_SYS_POCMR1_MASK_ATTRIB, CONFIG_SYS_PCI_MSTR_IO_LOCAL,
4850 CONFIG_SYS_PCI_MSTR_IO_BUS, CONFIG_SYS_CPU_PCI_IO_START, CONFIG_SYS_PCI_MSTR_IO_SIZE,
4851 CONFIG_SYS_POCMR2_MASK_ATTRIB: (MPC826x only)
4852 Overrides the default PCI memory map in arch/powerpc/cpu/mpc8260/pci.c if set.
4854 - CONFIG_PCI_DISABLE_PCIE:
4855 Disable PCI-Express on systems where it is supported but not
4858 - CONFIG_PCI_ENUM_ONLY
4859 Only scan through and get the devices on the buses.
4860 Don't do any setup work, presumably because someone or
4861 something has already done it, and we don't need to do it
4862 a second time. Useful for platforms that are pre-booted
4863 by coreboot or similar.
4865 - CONFIG_PCI_INDIRECT_BRIDGE:
4866 Enable support for indirect PCI bridges.
4869 Chip has SRIO or not
4872 Board has SRIO 1 port available
4875 Board has SRIO 2 port available
4877 - CONFIG_SRIO_PCIE_BOOT_MASTER
4878 Board can support master function for Boot from SRIO and PCIE
4880 - CONFIG_SYS_SRIOn_MEM_VIRT:
4881 Virtual Address of SRIO port 'n' memory region
4883 - CONFIG_SYS_SRIOn_MEM_PHYS:
4884 Physical Address of SRIO port 'n' memory region
4886 - CONFIG_SYS_SRIOn_MEM_SIZE:
4887 Size of SRIO port 'n' memory region
4889 - CONFIG_SYS_NAND_BUSWIDTH_16BIT
4890 Defined to tell the NAND controller that the NAND chip is using
4892 Not all NAND drivers use this symbol.
4893 Example of drivers that use it:
4894 - drivers/mtd/nand/ndfc.c
4895 - drivers/mtd/nand/mxc_nand.c
4897 - CONFIG_SYS_NDFC_EBC0_CFG
4898 Sets the EBC0_CFG register for the NDFC. If not defined
4899 a default value will be used.
4902 Get DDR timing information from an I2C EEPROM. Common
4903 with pluggable memory modules such as SODIMMs
4906 I2C address of the SPD EEPROM
4908 - CONFIG_SYS_SPD_BUS_NUM
4909 If SPD EEPROM is on an I2C bus other than the first
4910 one, specify here. Note that the value must resolve
4911 to something your driver can deal with.
4913 - CONFIG_SYS_DDR_RAW_TIMING
4914 Get DDR timing information from other than SPD. Common with
4915 soldered DDR chips onboard without SPD. DDR raw timing
4916 parameters are extracted from datasheet and hard-coded into
4917 header files or board specific files.
4919 - CONFIG_FSL_DDR_INTERACTIVE
4920 Enable interactive DDR debugging. See doc/README.fsl-ddr.
4922 - CONFIG_FSL_DDR_SYNC_REFRESH
4923 Enable sync of refresh for multiple controllers.
4925 - CONFIG_SYS_83XX_DDR_USES_CS0
4926 Only for 83xx systems. If specified, then DDR should
4927 be configured using CS0 and CS1 instead of CS2 and CS3.
4929 - CONFIG_ETHER_ON_FEC[12]
4930 Define to enable FEC[12] on a 8xx series processor.
4932 - CONFIG_FEC[12]_PHY
4933 Define to the hardcoded PHY address which corresponds
4934 to the given FEC; i. e.
4935 #define CONFIG_FEC1_PHY 4
4936 means that the PHY with address 4 is connected to FEC1
4938 When set to -1, means to probe for first available.
4940 - CONFIG_FEC[12]_PHY_NORXERR
4941 The PHY does not have a RXERR line (RMII only).
4942 (so program the FEC to ignore it).
4945 Enable RMII mode for all FECs.
4946 Note that this is a global option, we can't
4947 have one FEC in standard MII mode and another in RMII mode.
4949 - CONFIG_CRC32_VERIFY
4950 Add a verify option to the crc32 command.
4953 => crc32 -v <address> <count> <crc32>
4955 Where address/count indicate a memory area
4956 and crc32 is the correct crc32 which the
4960 Add the "loopw" memory command. This only takes effect if
4961 the memory commands are activated globally (CONFIG_CMD_MEM).
4964 Add the "mdc" and "mwc" memory commands. These are cyclic
4969 This command will print 4 bytes (10,11,12,13) each 500 ms.
4971 => mwc.l 100 12345678 10
4972 This command will write 12345678 to address 100 all 10 ms.
4974 This only takes effect if the memory commands are activated
4975 globally (CONFIG_CMD_MEM).
4977 - CONFIG_SKIP_LOWLEVEL_INIT
4978 [ARM, NDS32, MIPS only] If this variable is defined, then certain
4979 low level initializations (like setting up the memory
4980 controller) are omitted and/or U-Boot does not
4981 relocate itself into RAM.
4983 Normally this variable MUST NOT be defined. The only
4984 exception is when U-Boot is loaded (to RAM) by some
4985 other boot loader or by a debugger which performs
4986 these initializations itself.
4989 Modifies the behaviour of start.S when compiling a loader
4990 that is executed before the actual U-Boot. E.g. when
4991 compiling a NAND SPL.
4994 Modifies the behaviour of start.S when compiling a loader
4995 that is executed after the SPL and before the actual U-Boot.
4996 It is loaded by the SPL.
4998 - CONFIG_SYS_MPC85XX_NO_RESETVEC
4999 Only for 85xx systems. If this variable is specified, the section
5000 .resetvec is not kept and the section .bootpg is placed in the
5001 previous 4k of the .text section.
5003 - CONFIG_ARCH_MAP_SYSMEM
5004 Generally U-Boot (and in particular the md command) uses
5005 effective address. It is therefore not necessary to regard
5006 U-Boot address as virtual addresses that need to be translated
5007 to physical addresses. However, sandbox requires this, since
5008 it maintains its own little RAM buffer which contains all
5009 addressable memory. This option causes some memory accesses
5010 to be mapped through map_sysmem() / unmap_sysmem().
5012 - CONFIG_USE_ARCH_MEMCPY
5013 CONFIG_USE_ARCH_MEMSET
5014 If these options are used a optimized version of memcpy/memset will
5015 be used if available. These functions may be faster under some
5016 conditions but may increase the binary size.
5018 - CONFIG_X86_RESET_VECTOR
5019 If defined, the x86 reset vector code is included. This is not
5020 needed when U-Boot is running from Coreboot.
5023 Defines the MPU clock speed (in MHz).
5025 NOTE : currently only supported on AM335x platforms.
5027 - CONFIG_SPL_AM33XX_ENABLE_RTC32K_OSC:
5028 Enables the RTC32K OSC on AM33xx based plattforms
5030 - CONFIG_SYS_NAND_NO_SUBPAGE_WRITE
5031 Option to disable subpage write in NAND driver
5032 driver that uses this:
5033 drivers/mtd/nand/davinci_nand.c
5035 Freescale QE/FMAN Firmware Support:
5036 -----------------------------------
5038 The Freescale QUICCEngine (QE) and Frame Manager (FMAN) both support the
5039 loading of "firmware", which is encoded in the QE firmware binary format.
5040 This firmware often needs to be loaded during U-Boot booting, so macros
5041 are used to identify the storage device (NOR flash, SPI, etc) and the address
5044 - CONFIG_SYS_FMAN_FW_ADDR
5045 The address in the storage device where the FMAN microcode is located. The
5046 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
5049 - CONFIG_SYS_QE_FW_ADDR
5050 The address in the storage device where the QE microcode is located. The
5051 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
5054 - CONFIG_SYS_QE_FMAN_FW_LENGTH
5055 The maximum possible size of the firmware. The firmware binary format
5056 has a field that specifies the actual size of the firmware, but it
5057 might not be possible to read any part of the firmware unless some
5058 local storage is allocated to hold the entire firmware first.
5060 - CONFIG_SYS_QE_FMAN_FW_IN_NOR
5061 Specifies that QE/FMAN firmware is located in NOR flash, mapped as
5062 normal addressable memory via the LBC. CONFIG_SYS_FMAN_FW_ADDR is the
5063 virtual address in NOR flash.
5065 - CONFIG_SYS_QE_FMAN_FW_IN_NAND
5066 Specifies that QE/FMAN firmware is located in NAND flash.
5067 CONFIG_SYS_FMAN_FW_ADDR is the offset within NAND flash.
5069 - CONFIG_SYS_QE_FMAN_FW_IN_MMC
5070 Specifies that QE/FMAN firmware is located on the primary SD/MMC
5071 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
5073 - CONFIG_SYS_QE_FMAN_FW_IN_SPIFLASH
5074 Specifies that QE/FMAN firmware is located on the primary SPI
5075 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
5077 - CONFIG_SYS_QE_FMAN_FW_IN_REMOTE
5078 Specifies that QE/FMAN firmware is located in the remote (master)
5079 memory space. CONFIG_SYS_FMAN_FW_ADDR is a virtual address which
5080 can be mapped from slave TLB->slave LAW->slave SRIO or PCIE outbound
5081 window->master inbound window->master LAW->the ucode address in
5082 master's memory space.
5084 Freescale Layerscape Management Complex Firmware Support:
5085 ---------------------------------------------------------
5086 The Freescale Layerscape Management Complex (MC) supports the loading of
5088 This firmware often needs to be loaded during U-Boot booting, so macros
5089 are used to identify the storage device (NOR flash, SPI, etc) and the address
5092 - CONFIG_FSL_MC_ENET
5093 Enable the MC driver for Layerscape SoCs.
5095 - CONFIG_SYS_LS_MC_FW_ADDR
5096 The address in the storage device where the firmware is located. The
5097 meaning of this address depends on which CONFIG_SYS_LS_MC_FW_IN_xxx macro
5100 - CONFIG_SYS_LS_MC_FW_LENGTH
5101 The maximum possible size of the firmware. The firmware binary format
5102 has a field that specifies the actual size of the firmware, but it
5103 might not be possible to read any part of the firmware unless some
5104 local storage is allocated to hold the entire firmware first.
5106 - CONFIG_SYS_LS_MC_FW_IN_NOR
5107 Specifies that MC firmware is located in NOR flash, mapped as
5108 normal addressable memory via the LBC. CONFIG_SYS_LS_MC_FW_ADDR is the
5109 virtual address in NOR flash.
5111 Building the Software:
5112 ======================
5114 Building U-Boot has been tested in several native build environments
5115 and in many different cross environments. Of course we cannot support
5116 all possibly existing versions of cross development tools in all
5117 (potentially obsolete) versions. In case of tool chain problems we
5118 recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK)
5119 which is extensively used to build and test U-Boot.
5121 If you are not using a native environment, it is assumed that you
5122 have GNU cross compiling tools available in your path. In this case,
5123 you must set the environment variable CROSS_COMPILE in your shell.
5124 Note that no changes to the Makefile or any other source files are
5125 necessary. For example using the ELDK on a 4xx CPU, please enter:
5127 $ CROSS_COMPILE=ppc_4xx-
5128 $ export CROSS_COMPILE
5130 Note: If you wish to generate Windows versions of the utilities in
5131 the tools directory you can use the MinGW toolchain
5132 (http://www.mingw.org). Set your HOST tools to the MinGW
5133 toolchain and execute 'make tools'. For example:
5135 $ make HOSTCC=i586-mingw32msvc-gcc HOSTSTRIP=i586-mingw32msvc-strip tools
5137 Binaries such as tools/mkimage.exe will be created which can
5138 be executed on computers running Windows.
5140 U-Boot is intended to be simple to build. After installing the
5141 sources you must configure U-Boot for one specific board type. This
5146 where "NAME_defconfig" is the name of one of the existing configu-
5147 rations; see boards.cfg for supported names.
5149 Note: for some board special configuration names may exist; check if
5150 additional information is available from the board vendor; for
5151 instance, the TQM823L systems are available without (standard)
5152 or with LCD support. You can select such additional "features"
5153 when choosing the configuration, i. e.
5155 make TQM823L_defconfig
5156 - will configure for a plain TQM823L, i. e. no LCD support
5158 make TQM823L_LCD_defconfig
5159 - will configure for a TQM823L with U-Boot console on LCD
5164 Finally, type "make all", and you should get some working U-Boot
5165 images ready for download to / installation on your system:
5167 - "u-boot.bin" is a raw binary image
5168 - "u-boot" is an image in ELF binary format
5169 - "u-boot.srec" is in Motorola S-Record format
5171 By default the build is performed locally and the objects are saved
5172 in the source directory. One of the two methods can be used to change
5173 this behavior and build U-Boot to some external directory:
5175 1. Add O= to the make command line invocations:
5177 make O=/tmp/build distclean
5178 make O=/tmp/build NAME_defconfig
5179 make O=/tmp/build all
5181 2. Set environment variable KBUILD_OUTPUT to point to the desired location:
5183 export KBUILD_OUTPUT=/tmp/build
5188 Note that the command line "O=" setting overrides the KBUILD_OUTPUT environment
5192 Please be aware that the Makefiles assume you are using GNU make, so
5193 for instance on NetBSD you might need to use "gmake" instead of
5197 If the system board that you have is not listed, then you will need
5198 to port U-Boot to your hardware platform. To do this, follow these
5201 1. Add a new configuration option for your board to the toplevel
5202 "boards.cfg" file, using the existing entries as examples.
5203 Follow the instructions there to keep the boards in order.
5204 2. Create a new directory to hold your board specific code. Add any
5205 files you need. In your board directory, you will need at least
5206 the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds".
5207 3. Create a new configuration file "include/configs/<board>.h" for
5209 3. If you're porting U-Boot to a new CPU, then also create a new
5210 directory to hold your CPU specific code. Add any files you need.
5211 4. Run "make <board>_defconfig" with your new name.
5212 5. Type "make", and you should get a working "u-boot.srec" file
5213 to be installed on your target system.
5214 6. Debug and solve any problems that might arise.
5215 [Of course, this last step is much harder than it sounds.]
5218 Testing of U-Boot Modifications, Ports to New Hardware, etc.:
5219 ==============================================================
5221 If you have modified U-Boot sources (for instance added a new board
5222 or support for new devices, a new CPU, etc.) you are expected to
5223 provide feedback to the other developers. The feedback normally takes
5224 the form of a "patch", i. e. a context diff against a certain (latest
5225 official or latest in the git repository) version of U-Boot sources.
5227 But before you submit such a patch, please verify that your modifi-
5228 cation did not break existing code. At least make sure that *ALL* of
5229 the supported boards compile WITHOUT ANY compiler warnings. To do so,
5230 just run the "MAKEALL" script, which will configure and build U-Boot
5231 for ALL supported system. Be warned, this will take a while. You can
5232 select which (cross) compiler to use by passing a `CROSS_COMPILE'
5233 environment variable to the script, i. e. to use the ELDK cross tools
5236 CROSS_COMPILE=ppc_8xx- MAKEALL
5238 or to build on a native PowerPC system you can type
5240 CROSS_COMPILE=' ' MAKEALL
5242 When using the MAKEALL script, the default behaviour is to build
5243 U-Boot in the source directory. This location can be changed by
5244 setting the BUILD_DIR environment variable. Also, for each target
5245 built, the MAKEALL script saves two log files (<target>.ERR and
5246 <target>.MAKEALL) in the <source dir>/LOG directory. This default
5247 location can be changed by setting the MAKEALL_LOGDIR environment
5248 variable. For example:
5250 export BUILD_DIR=/tmp/build
5251 export MAKEALL_LOGDIR=/tmp/log
5252 CROSS_COMPILE=ppc_8xx- MAKEALL
5254 With the above settings build objects are saved in the /tmp/build,
5255 log files are saved in the /tmp/log and the source tree remains clean
5256 during the whole build process.
5259 See also "U-Boot Porting Guide" below.
5262 Monitor Commands - Overview:
5263 ============================
5265 go - start application at address 'addr'
5266 run - run commands in an environment variable
5267 bootm - boot application image from memory
5268 bootp - boot image via network using BootP/TFTP protocol
5269 bootz - boot zImage from memory
5270 tftpboot- boot image via network using TFTP protocol
5271 and env variables "ipaddr" and "serverip"
5272 (and eventually "gatewayip")
5273 tftpput - upload a file via network using TFTP protocol
5274 rarpboot- boot image via network using RARP/TFTP protocol
5275 diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
5276 loads - load S-Record file over serial line
5277 loadb - load binary file over serial line (kermit mode)
5279 mm - memory modify (auto-incrementing)
5280 nm - memory modify (constant address)
5281 mw - memory write (fill)
5283 cmp - memory compare
5284 crc32 - checksum calculation
5285 i2c - I2C sub-system
5286 sspi - SPI utility commands
5287 base - print or set address offset
5288 printenv- print environment variables
5289 setenv - set environment variables
5290 saveenv - save environment variables to persistent storage
5291 protect - enable or disable FLASH write protection
5292 erase - erase FLASH memory
5293 flinfo - print FLASH memory information
5294 nand - NAND memory operations (see doc/README.nand)
5295 bdinfo - print Board Info structure
5296 iminfo - print header information for application image
5297 coninfo - print console devices and informations
5298 ide - IDE sub-system
5299 loop - infinite loop on address range
5300 loopw - infinite write loop on address range
5301 mtest - simple RAM test
5302 icache - enable or disable instruction cache
5303 dcache - enable or disable data cache
5304 reset - Perform RESET of the CPU
5305 echo - echo args to console
5306 version - print monitor version
5307 help - print online help
5308 ? - alias for 'help'
5311 Monitor Commands - Detailed Description:
5312 ========================================
5316 For now: just type "help <command>".
5319 Environment Variables:
5320 ======================
5322 U-Boot supports user configuration using Environment Variables which
5323 can be made persistent by saving to Flash memory.
5325 Environment Variables are set using "setenv", printed using
5326 "printenv", and saved to Flash using "saveenv". Using "setenv"
5327 without a value can be used to delete a variable from the
5328 environment. As long as you don't save the environment you are
5329 working with an in-memory copy. In case the Flash area containing the
5330 environment is erased by accident, a default environment is provided.
5332 Some configuration options can be set using Environment Variables.
5334 List of environment variables (most likely not complete):
5336 baudrate - see CONFIG_BAUDRATE
5338 bootdelay - see CONFIG_BOOTDELAY
5340 bootcmd - see CONFIG_BOOTCOMMAND
5342 bootargs - Boot arguments when booting an RTOS image
5344 bootfile - Name of the image to load with TFTP
5346 bootm_low - Memory range available for image processing in the bootm
5347 command can be restricted. This variable is given as
5348 a hexadecimal number and defines lowest address allowed
5349 for use by the bootm command. See also "bootm_size"
5350 environment variable. Address defined by "bootm_low" is
5351 also the base of the initial memory mapping for the Linux
5352 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ and
5355 bootm_mapsize - Size of the initial memory mapping for the Linux kernel.
5356 This variable is given as a hexadecimal number and it
5357 defines the size of the memory region starting at base
5358 address bootm_low that is accessible by the Linux kernel
5359 during early boot. If unset, CONFIG_SYS_BOOTMAPSZ is used
5360 as the default value if it is defined, and bootm_size is
5363 bootm_size - Memory range available for image processing in the bootm
5364 command can be restricted. This variable is given as
5365 a hexadecimal number and defines the size of the region
5366 allowed for use by the bootm command. See also "bootm_low"
5367 environment variable.
5369 updatefile - Location of the software update file on a TFTP server, used
5370 by the automatic software update feature. Please refer to
5371 documentation in doc/README.update for more details.
5373 autoload - if set to "no" (any string beginning with 'n'),
5374 "bootp" will just load perform a lookup of the
5375 configuration from the BOOTP server, but not try to
5376 load any image using TFTP
5378 autostart - if set to "yes", an image loaded using the "bootp",
5379 "rarpboot", "tftpboot" or "diskboot" commands will
5380 be automatically started (by internally calling
5383 If set to "no", a standalone image passed to the
5384 "bootm" command will be copied to the load address
5385 (and eventually uncompressed), but NOT be started.
5386 This can be used to load and uncompress arbitrary
5389 fdt_high - if set this restricts the maximum address that the
5390 flattened device tree will be copied into upon boot.
5391 For example, if you have a system with 1 GB memory
5392 at physical address 0x10000000, while Linux kernel
5393 only recognizes the first 704 MB as low memory, you
5394 may need to set fdt_high as 0x3C000000 to have the
5395 device tree blob be copied to the maximum address
5396 of the 704 MB low memory, so that Linux kernel can
5397 access it during the boot procedure.
5399 If this is set to the special value 0xFFFFFFFF then
5400 the fdt will not be copied at all on boot. For this
5401 to work it must reside in writable memory, have
5402 sufficient padding on the end of it for u-boot to
5403 add the information it needs into it, and the memory
5404 must be accessible by the kernel.
5406 fdtcontroladdr- if set this is the address of the control flattened
5407 device tree used by U-Boot when CONFIG_OF_CONTROL is
5410 i2cfast - (PPC405GP|PPC405EP only)
5411 if set to 'y' configures Linux I2C driver for fast
5412 mode (400kHZ). This environment variable is used in
5413 initialization code. So, for changes to be effective
5414 it must be saved and board must be reset.
5416 initrd_high - restrict positioning of initrd images:
5417 If this variable is not set, initrd images will be
5418 copied to the highest possible address in RAM; this
5419 is usually what you want since it allows for
5420 maximum initrd size. If for some reason you want to
5421 make sure that the initrd image is loaded below the
5422 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment
5423 variable to a value of "no" or "off" or "0".
5424 Alternatively, you can set it to a maximum upper
5425 address to use (U-Boot will still check that it
5426 does not overwrite the U-Boot stack and data).
5428 For instance, when you have a system with 16 MB
5429 RAM, and want to reserve 4 MB from use by Linux,
5430 you can do this by adding "mem=12M" to the value of
5431 the "bootargs" variable. However, now you must make
5432 sure that the initrd image is placed in the first
5433 12 MB as well - this can be done with
5435 setenv initrd_high 00c00000
5437 If you set initrd_high to 0xFFFFFFFF, this is an
5438 indication to U-Boot that all addresses are legal
5439 for the Linux kernel, including addresses in flash
5440 memory. In this case U-Boot will NOT COPY the
5441 ramdisk at all. This may be useful to reduce the
5442 boot time on your system, but requires that this
5443 feature is supported by your Linux kernel.
5445 ipaddr - IP address; needed for tftpboot command
5447 loadaddr - Default load address for commands like "bootp",
5448 "rarpboot", "tftpboot", "loadb" or "diskboot"
5450 loads_echo - see CONFIG_LOADS_ECHO
5452 serverip - TFTP server IP address; needed for tftpboot command
5454 bootretry - see CONFIG_BOOT_RETRY_TIME
5456 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
5458 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
5460 ethprime - controls which interface is used first.
5462 ethact - controls which interface is currently active.
5463 For example you can do the following
5465 => setenv ethact FEC
5466 => ping 192.168.0.1 # traffic sent on FEC
5467 => setenv ethact SCC
5468 => ping 10.0.0.1 # traffic sent on SCC
5470 ethrotate - When set to "no" U-Boot does not go through all
5471 available network interfaces.
5472 It just stays at the currently selected interface.
5474 netretry - When set to "no" each network operation will
5475 either succeed or fail without retrying.
5476 When set to "once" the network operation will
5477 fail when all the available network interfaces
5478 are tried once without success.
5479 Useful on scripts which control the retry operation
5482 npe_ucode - set load address for the NPE microcode
5484 silent_linux - If set then Linux will be told to boot silently, by
5485 changing the console to be empty. If "yes" it will be
5486 made silent. If "no" it will not be made silent. If
5487 unset, then it will be made silent if the U-Boot console
5490 tftpsrcport - If this is set, the value is used for TFTP's
5493 tftpdstport - If this is set, the value is used for TFTP's UDP
5494 destination port instead of the Well Know Port 69.
5496 tftpblocksize - Block size to use for TFTP transfers; if not set,
5497 we use the TFTP server's default block size
5499 tftptimeout - Retransmission timeout for TFTP packets (in milli-
5500 seconds, minimum value is 1000 = 1 second). Defines
5501 when a packet is considered to be lost so it has to
5502 be retransmitted. The default is 5000 = 5 seconds.
5503 Lowering this value may make downloads succeed
5504 faster in networks with high packet loss rates or
5505 with unreliable TFTP servers.
5507 vlan - When set to a value < 4095 the traffic over
5508 Ethernet is encapsulated/received over 802.1q
5511 The following image location variables contain the location of images
5512 used in booting. The "Image" column gives the role of the image and is
5513 not an environment variable name. The other columns are environment
5514 variable names. "File Name" gives the name of the file on a TFTP
5515 server, "RAM Address" gives the location in RAM the image will be
5516 loaded to, and "Flash Location" gives the image's address in NOR
5517 flash or offset in NAND flash.
5519 *Note* - these variables don't have to be defined for all boards, some
5520 boards currenlty use other variables for these purposes, and some
5521 boards use these variables for other purposes.
5523 Image File Name RAM Address Flash Location
5524 ----- --------- ----------- --------------
5525 u-boot u-boot u-boot_addr_r u-boot_addr
5526 Linux kernel bootfile kernel_addr_r kernel_addr
5527 device tree blob fdtfile fdt_addr_r fdt_addr
5528 ramdisk ramdiskfile ramdisk_addr_r ramdisk_addr
5530 The following environment variables may be used and automatically
5531 updated by the network boot commands ("bootp" and "rarpboot"),
5532 depending the information provided by your boot server:
5534 bootfile - see above
5535 dnsip - IP address of your Domain Name Server
5536 dnsip2 - IP address of your secondary Domain Name Server
5537 gatewayip - IP address of the Gateway (Router) to use
5538 hostname - Target hostname
5540 netmask - Subnet Mask
5541 rootpath - Pathname of the root filesystem on the NFS server
5542 serverip - see above
5545 There are two special Environment Variables:
5547 serial# - contains hardware identification information such
5548 as type string and/or serial number
5549 ethaddr - Ethernet address
5551 These variables can be set only once (usually during manufacturing of
5552 the board). U-Boot refuses to delete or overwrite these variables
5553 once they have been set once.
5556 Further special Environment Variables:
5558 ver - Contains the U-Boot version string as printed
5559 with the "version" command. This variable is
5560 readonly (see CONFIG_VERSION_VARIABLE).
5563 Please note that changes to some configuration parameters may take
5564 only effect after the next boot (yes, that's just like Windoze :-).
5567 Callback functions for environment variables:
5568 ---------------------------------------------
5570 For some environment variables, the behavior of u-boot needs to change
5571 when their values are changed. This functionality allows functions to
5572 be associated with arbitrary variables. On creation, overwrite, or
5573 deletion, the callback will provide the opportunity for some side
5574 effect to happen or for the change to be rejected.
5576 The callbacks are named and associated with a function using the
5577 U_BOOT_ENV_CALLBACK macro in your board or driver code.
5579 These callbacks are associated with variables in one of two ways. The
5580 static list can be added to by defining CONFIG_ENV_CALLBACK_LIST_STATIC
5581 in the board configuration to a string that defines a list of
5582 associations. The list must be in the following format:
5584 entry = variable_name[:callback_name]
5587 If the callback name is not specified, then the callback is deleted.
5588 Spaces are also allowed anywhere in the list.
5590 Callbacks can also be associated by defining the ".callbacks" variable
5591 with the same list format above. Any association in ".callbacks" will
5592 override any association in the static list. You can define
5593 CONFIG_ENV_CALLBACK_LIST_DEFAULT to a list (string) to define the
5594 ".callbacks" environment variable in the default or embedded environment.
5597 Command Line Parsing:
5598 =====================
5600 There are two different command line parsers available with U-Boot:
5601 the old "simple" one, and the much more powerful "hush" shell:
5603 Old, simple command line parser:
5604 --------------------------------
5606 - supports environment variables (through setenv / saveenv commands)
5607 - several commands on one line, separated by ';'
5608 - variable substitution using "... ${name} ..." syntax
5609 - special characters ('$', ';') can be escaped by prefixing with '\',
5611 setenv bootcmd bootm \${address}
5612 - You can also escape text by enclosing in single apostrophes, for example:
5613 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
5618 - similar to Bourne shell, with control structures like
5619 if...then...else...fi, for...do...done; while...do...done,
5620 until...do...done, ...
5621 - supports environment ("global") variables (through setenv / saveenv
5622 commands) and local shell variables (through standard shell syntax
5623 "name=value"); only environment variables can be used with "run"
5629 (1) If a command line (or an environment variable executed by a "run"
5630 command) contains several commands separated by semicolon, and
5631 one of these commands fails, then the remaining commands will be
5634 (2) If you execute several variables with one call to run (i. e.
5635 calling run with a list of variables as arguments), any failing
5636 command will cause "run" to terminate, i. e. the remaining
5637 variables are not executed.
5639 Note for Redundant Ethernet Interfaces:
5640 =======================================
5642 Some boards come with redundant Ethernet interfaces; U-Boot supports
5643 such configurations and is capable of automatic selection of a
5644 "working" interface when needed. MAC assignment works as follows:
5646 Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
5647 MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
5648 "eth1addr" (=>eth1), "eth2addr", ...
5650 If the network interface stores some valid MAC address (for instance
5651 in SROM), this is used as default address if there is NO correspon-
5652 ding setting in the environment; if the corresponding environment
5653 variable is set, this overrides the settings in the card; that means:
5655 o If the SROM has a valid MAC address, and there is no address in the
5656 environment, the SROM's address is used.
5658 o If there is no valid address in the SROM, and a definition in the
5659 environment exists, then the value from the environment variable is
5662 o If both the SROM and the environment contain a MAC address, and
5663 both addresses are the same, this MAC address is used.
5665 o If both the SROM and the environment contain a MAC address, and the
5666 addresses differ, the value from the environment is used and a
5669 o If neither SROM nor the environment contain a MAC address, an error
5672 If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses
5673 will be programmed into hardware as part of the initialization process. This
5674 may be skipped by setting the appropriate 'ethmacskip' environment variable.
5675 The naming convention is as follows:
5676 "ethmacskip" (=>eth0), "eth1macskip" (=>eth1) etc.
5681 U-Boot is capable of booting (and performing other auxiliary operations on)
5682 images in two formats:
5684 New uImage format (FIT)
5685 -----------------------
5687 Flexible and powerful format based on Flattened Image Tree -- FIT (similar
5688 to Flattened Device Tree). It allows the use of images with multiple
5689 components (several kernels, ramdisks, etc.), with contents protected by
5690 SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory.
5696 Old image format is based on binary files which can be basically anything,
5697 preceded by a special header; see the definitions in include/image.h for
5698 details; basically, the header defines the following image properties:
5700 * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
5701 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
5702 LynxOS, pSOS, QNX, RTEMS, INTEGRITY;
5703 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS,
5705 * Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86,
5706 IA64, MIPS, NDS32, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
5707 Currently supported: ARM, AVR32, Intel x86, MIPS, NDS32, Nios II, PowerPC).
5708 * Compression Type (uncompressed, gzip, bzip2)
5714 The header is marked by a special Magic Number, and both the header
5715 and the data portions of the image are secured against corruption by
5722 Although U-Boot should support any OS or standalone application
5723 easily, the main focus has always been on Linux during the design of
5726 U-Boot includes many features that so far have been part of some
5727 special "boot loader" code within the Linux kernel. Also, any
5728 "initrd" images to be used are no longer part of one big Linux image;
5729 instead, kernel and "initrd" are separate images. This implementation
5730 serves several purposes:
5732 - the same features can be used for other OS or standalone
5733 applications (for instance: using compressed images to reduce the
5734 Flash memory footprint)
5736 - it becomes much easier to port new Linux kernel versions because
5737 lots of low-level, hardware dependent stuff are done by U-Boot
5739 - the same Linux kernel image can now be used with different "initrd"
5740 images; of course this also means that different kernel images can
5741 be run with the same "initrd". This makes testing easier (you don't
5742 have to build a new "zImage.initrd" Linux image when you just
5743 change a file in your "initrd"). Also, a field-upgrade of the
5744 software is easier now.
5750 Porting Linux to U-Boot based systems:
5751 ---------------------------------------
5753 U-Boot cannot save you from doing all the necessary modifications to
5754 configure the Linux device drivers for use with your target hardware
5755 (no, we don't intend to provide a full virtual machine interface to
5758 But now you can ignore ALL boot loader code (in arch/powerpc/mbxboot).
5760 Just make sure your machine specific header file (for instance
5761 include/asm-ppc/tqm8xx.h) includes the same definition of the Board
5762 Information structure as we define in include/asm-<arch>/u-boot.h,
5763 and make sure that your definition of IMAP_ADDR uses the same value
5764 as your U-Boot configuration in CONFIG_SYS_IMMR.
5766 Note that U-Boot now has a driver model, a unified model for drivers.
5767 If you are adding a new driver, plumb it into driver model. If there
5768 is no uclass available, you are encouraged to create one. See
5772 Configuring the Linux kernel:
5773 -----------------------------
5775 No specific requirements for U-Boot. Make sure you have some root
5776 device (initial ramdisk, NFS) for your target system.
5779 Building a Linux Image:
5780 -----------------------
5782 With U-Boot, "normal" build targets like "zImage" or "bzImage" are
5783 not used. If you use recent kernel source, a new build target
5784 "uImage" will exist which automatically builds an image usable by
5785 U-Boot. Most older kernels also have support for a "pImage" target,
5786 which was introduced for our predecessor project PPCBoot and uses a
5787 100% compatible format.
5791 make TQM850L_defconfig
5796 The "uImage" build target uses a special tool (in 'tools/mkimage') to
5797 encapsulate a compressed Linux kernel image with header information,
5798 CRC32 checksum etc. for use with U-Boot. This is what we are doing:
5800 * build a standard "vmlinux" kernel image (in ELF binary format):
5802 * convert the kernel into a raw binary image:
5804 ${CROSS_COMPILE}-objcopy -O binary \
5805 -R .note -R .comment \
5806 -S vmlinux linux.bin
5808 * compress the binary image:
5812 * package compressed binary image for U-Boot:
5814 mkimage -A ppc -O linux -T kernel -C gzip \
5815 -a 0 -e 0 -n "Linux Kernel Image" \
5816 -d linux.bin.gz uImage
5819 The "mkimage" tool can also be used to create ramdisk images for use
5820 with U-Boot, either separated from the Linux kernel image, or
5821 combined into one file. "mkimage" encapsulates the images with a 64
5822 byte header containing information about target architecture,
5823 operating system, image type, compression method, entry points, time
5824 stamp, CRC32 checksums, etc.
5826 "mkimage" can be called in two ways: to verify existing images and
5827 print the header information, or to build new images.
5829 In the first form (with "-l" option) mkimage lists the information
5830 contained in the header of an existing U-Boot image; this includes
5831 checksum verification:
5833 tools/mkimage -l image
5834 -l ==> list image header information
5836 The second form (with "-d" option) is used to build a U-Boot image
5837 from a "data file" which is used as image payload:
5839 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
5840 -n name -d data_file image
5841 -A ==> set architecture to 'arch'
5842 -O ==> set operating system to 'os'
5843 -T ==> set image type to 'type'
5844 -C ==> set compression type 'comp'
5845 -a ==> set load address to 'addr' (hex)
5846 -e ==> set entry point to 'ep' (hex)
5847 -n ==> set image name to 'name'
5848 -d ==> use image data from 'datafile'
5850 Right now, all Linux kernels for PowerPC systems use the same load
5851 address (0x00000000), but the entry point address depends on the
5854 - 2.2.x kernels have the entry point at 0x0000000C,
5855 - 2.3.x and later kernels have the entry point at 0x00000000.
5857 So a typical call to build a U-Boot image would read:
5859 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
5860 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
5861 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz \
5862 > examples/uImage.TQM850L
5863 Image Name: 2.4.4 kernel for TQM850L
5864 Created: Wed Jul 19 02:34:59 2000
5865 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5866 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
5867 Load Address: 0x00000000
5868 Entry Point: 0x00000000
5870 To verify the contents of the image (or check for corruption):
5872 -> tools/mkimage -l examples/uImage.TQM850L
5873 Image Name: 2.4.4 kernel for TQM850L
5874 Created: Wed Jul 19 02:34:59 2000
5875 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5876 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
5877 Load Address: 0x00000000
5878 Entry Point: 0x00000000
5880 NOTE: for embedded systems where boot time is critical you can trade
5881 speed for memory and install an UNCOMPRESSED image instead: this
5882 needs more space in Flash, but boots much faster since it does not
5883 need to be uncompressed:
5885 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz
5886 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
5887 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
5888 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux \
5889 > examples/uImage.TQM850L-uncompressed
5890 Image Name: 2.4.4 kernel for TQM850L
5891 Created: Wed Jul 19 02:34:59 2000
5892 Image Type: PowerPC Linux Kernel Image (uncompressed)
5893 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
5894 Load Address: 0x00000000
5895 Entry Point: 0x00000000
5898 Similar you can build U-Boot images from a 'ramdisk.image.gz' file
5899 when your kernel is intended to use an initial ramdisk:
5901 -> tools/mkimage -n 'Simple Ramdisk Image' \
5902 > -A ppc -O linux -T ramdisk -C gzip \
5903 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
5904 Image Name: Simple Ramdisk Image
5905 Created: Wed Jan 12 14:01:50 2000
5906 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5907 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
5908 Load Address: 0x00000000
5909 Entry Point: 0x00000000
5911 The "dumpimage" is a tool to disassemble images built by mkimage. Its "-i"
5912 option performs the converse operation of the mkimage's second form (the "-d"
5913 option). Given an image built by mkimage, the dumpimage extracts a "data file"
5916 tools/dumpimage -i image -T type -p position data_file
5917 -i ==> extract from the 'image' a specific 'data_file'
5918 -T ==> set image type to 'type'
5919 -p ==> 'position' (starting at 0) of the 'data_file' inside the 'image'
5922 Installing a Linux Image:
5923 -------------------------
5925 To downloading a U-Boot image over the serial (console) interface,
5926 you must convert the image to S-Record format:
5928 objcopy -I binary -O srec examples/image examples/image.srec
5930 The 'objcopy' does not understand the information in the U-Boot
5931 image header, so the resulting S-Record file will be relative to
5932 address 0x00000000. To load it to a given address, you need to
5933 specify the target address as 'offset' parameter with the 'loads'
5936 Example: install the image to address 0x40100000 (which on the
5937 TQM8xxL is in the first Flash bank):
5939 => erase 40100000 401FFFFF
5945 ## Ready for S-Record download ...
5946 ~>examples/image.srec
5947 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
5949 15989 15990 15991 15992
5950 [file transfer complete]
5952 ## Start Addr = 0x00000000
5955 You can check the success of the download using the 'iminfo' command;
5956 this includes a checksum verification so you can be sure no data
5957 corruption happened:
5961 ## Checking Image at 40100000 ...
5962 Image Name: 2.2.13 for initrd on TQM850L
5963 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5964 Data Size: 335725 Bytes = 327 kB = 0 MB
5965 Load Address: 00000000
5966 Entry Point: 0000000c
5967 Verifying Checksum ... OK
5973 The "bootm" command is used to boot an application that is stored in
5974 memory (RAM or Flash). In case of a Linux kernel image, the contents
5975 of the "bootargs" environment variable is passed to the kernel as
5976 parameters. You can check and modify this variable using the
5977 "printenv" and "setenv" commands:
5980 => printenv bootargs
5981 bootargs=root=/dev/ram
5983 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5985 => printenv bootargs
5986 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5989 ## Booting Linux kernel at 40020000 ...
5990 Image Name: 2.2.13 for NFS on TQM850L
5991 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5992 Data Size: 381681 Bytes = 372 kB = 0 MB
5993 Load Address: 00000000
5994 Entry Point: 0000000c
5995 Verifying Checksum ... OK
5996 Uncompressing Kernel Image ... OK
5997 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
5998 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5999 time_init: decrementer frequency = 187500000/60
6000 Calibrating delay loop... 49.77 BogoMIPS
6001 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
6004 If you want to boot a Linux kernel with initial RAM disk, you pass
6005 the memory addresses of both the kernel and the initrd image (PPBCOOT
6006 format!) to the "bootm" command:
6008 => imi 40100000 40200000
6010 ## Checking Image at 40100000 ...
6011 Image Name: 2.2.13 for initrd on TQM850L
6012 Image Type: PowerPC Linux Kernel Image (gzip compressed)
6013 Data Size: 335725 Bytes = 327 kB = 0 MB
6014 Load Address: 00000000
6015 Entry Point: 0000000c
6016 Verifying Checksum ... OK
6018 ## Checking Image at 40200000 ...
6019 Image Name: Simple Ramdisk Image
6020 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
6021 Data Size: 566530 Bytes = 553 kB = 0 MB
6022 Load Address: 00000000
6023 Entry Point: 00000000
6024 Verifying Checksum ... OK
6026 => bootm 40100000 40200000
6027 ## Booting Linux kernel at 40100000 ...
6028 Image Name: 2.2.13 for initrd on TQM850L
6029 Image Type: PowerPC Linux Kernel Image (gzip compressed)
6030 Data Size: 335725 Bytes = 327 kB = 0 MB
6031 Load Address: 00000000
6032 Entry Point: 0000000c
6033 Verifying Checksum ... OK
6034 Uncompressing Kernel Image ... OK
6035 ## Loading RAMDisk Image at 40200000 ...
6036 Image Name: Simple Ramdisk Image
6037 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
6038 Data Size: 566530 Bytes = 553 kB = 0 MB
6039 Load Address: 00000000
6040 Entry Point: 00000000
6041 Verifying Checksum ... OK
6042 Loading Ramdisk ... OK
6043 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
6044 Boot arguments: root=/dev/ram
6045 time_init: decrementer frequency = 187500000/60
6046 Calibrating delay loop... 49.77 BogoMIPS
6048 RAMDISK: Compressed image found at block 0
6049 VFS: Mounted root (ext2 filesystem).
6053 Boot Linux and pass a flat device tree:
6056 First, U-Boot must be compiled with the appropriate defines. See the section
6057 titled "Linux Kernel Interface" above for a more in depth explanation. The
6058 following is an example of how to start a kernel and pass an updated
6064 oft=oftrees/mpc8540ads.dtb
6065 => tftp $oftaddr $oft
6066 Speed: 1000, full duplex
6068 TFTP from server 192.168.1.1; our IP address is 192.168.1.101
6069 Filename 'oftrees/mpc8540ads.dtb'.
6070 Load address: 0x300000
6073 Bytes transferred = 4106 (100a hex)
6074 => tftp $loadaddr $bootfile
6075 Speed: 1000, full duplex
6077 TFTP from server 192.168.1.1; our IP address is 192.168.1.2
6079 Load address: 0x200000
6080 Loading:############
6082 Bytes transferred = 1029407 (fb51f hex)
6087 => bootm $loadaddr - $oftaddr
6088 ## Booting image at 00200000 ...
6089 Image Name: Linux-2.6.17-dirty
6090 Image Type: PowerPC Linux Kernel Image (gzip compressed)
6091 Data Size: 1029343 Bytes = 1005.2 kB
6092 Load Address: 00000000
6093 Entry Point: 00000000
6094 Verifying Checksum ... OK
6095 Uncompressing Kernel Image ... OK
6096 Booting using flat device tree at 0x300000
6097 Using MPC85xx ADS machine description
6098 Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb
6102 More About U-Boot Image Types:
6103 ------------------------------
6105 U-Boot supports the following image types:
6107 "Standalone Programs" are directly runnable in the environment
6108 provided by U-Boot; it is expected that (if they behave
6109 well) you can continue to work in U-Boot after return from
6110 the Standalone Program.
6111 "OS Kernel Images" are usually images of some Embedded OS which
6112 will take over control completely. Usually these programs
6113 will install their own set of exception handlers, device
6114 drivers, set up the MMU, etc. - this means, that you cannot
6115 expect to re-enter U-Boot except by resetting the CPU.
6116 "RAMDisk Images" are more or less just data blocks, and their
6117 parameters (address, size) are passed to an OS kernel that is
6119 "Multi-File Images" contain several images, typically an OS
6120 (Linux) kernel image and one or more data images like
6121 RAMDisks. This construct is useful for instance when you want
6122 to boot over the network using BOOTP etc., where the boot
6123 server provides just a single image file, but you want to get
6124 for instance an OS kernel and a RAMDisk image.
6126 "Multi-File Images" start with a list of image sizes, each
6127 image size (in bytes) specified by an "uint32_t" in network
6128 byte order. This list is terminated by an "(uint32_t)0".
6129 Immediately after the terminating 0 follow the images, one by
6130 one, all aligned on "uint32_t" boundaries (size rounded up to
6131 a multiple of 4 bytes).
6133 "Firmware Images" are binary images containing firmware (like
6134 U-Boot or FPGA images) which usually will be programmed to
6137 "Script files" are command sequences that will be executed by
6138 U-Boot's command interpreter; this feature is especially
6139 useful when you configure U-Boot to use a real shell (hush)
6140 as command interpreter.
6142 Booting the Linux zImage:
6143 -------------------------
6145 On some platforms, it's possible to boot Linux zImage. This is done
6146 using the "bootz" command. The syntax of "bootz" command is the same
6147 as the syntax of "bootm" command.
6149 Note, defining the CONFIG_SUPPORT_RAW_INITRD allows user to supply
6150 kernel with raw initrd images. The syntax is slightly different, the
6151 address of the initrd must be augmented by it's size, in the following
6152 format: "<initrd addres>:<initrd size>".
6158 One of the features of U-Boot is that you can dynamically load and
6159 run "standalone" applications, which can use some resources of
6160 U-Boot like console I/O functions or interrupt services.
6162 Two simple examples are included with the sources:
6167 'examples/hello_world.c' contains a small "Hello World" Demo
6168 application; it is automatically compiled when you build U-Boot.
6169 It's configured to run at address 0x00040004, so you can play with it
6173 ## Ready for S-Record download ...
6174 ~>examples/hello_world.srec
6175 1 2 3 4 5 6 7 8 9 10 11 ...
6176 [file transfer complete]
6178 ## Start Addr = 0x00040004
6180 => go 40004 Hello World! This is a test.
6181 ## Starting application at 0x00040004 ...
6192 Hit any key to exit ...
6194 ## Application terminated, rc = 0x0
6196 Another example, which demonstrates how to register a CPM interrupt
6197 handler with the U-Boot code, can be found in 'examples/timer.c'.
6198 Here, a CPM timer is set up to generate an interrupt every second.
6199 The interrupt service routine is trivial, just printing a '.'
6200 character, but this is just a demo program. The application can be
6201 controlled by the following keys:
6203 ? - print current values og the CPM Timer registers
6204 b - enable interrupts and start timer
6205 e - stop timer and disable interrupts
6206 q - quit application
6209 ## Ready for S-Record download ...
6210 ~>examples/timer.srec
6211 1 2 3 4 5 6 7 8 9 10 11 ...
6212 [file transfer complete]
6214 ## Start Addr = 0x00040004
6217 ## Starting application at 0x00040004 ...
6220 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
6223 [q, b, e, ?] Set interval 1000000 us
6226 [q, b, e, ?] ........
6227 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
6230 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
6233 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
6236 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
6238 [q, b, e, ?] ...Stopping timer
6240 [q, b, e, ?] ## Application terminated, rc = 0x0
6246 Over time, many people have reported problems when trying to use the
6247 "minicom" terminal emulation program for serial download. I (wd)
6248 consider minicom to be broken, and recommend not to use it. Under
6249 Unix, I recommend to use C-Kermit for general purpose use (and
6250 especially for kermit binary protocol download ("loadb" command), and
6251 use "cu" for S-Record download ("loads" command). See
6252 http://www.denx.de/wiki/view/DULG/SystemSetup#Section_4.3.
6253 for help with kermit.
6256 Nevertheless, if you absolutely want to use it try adding this
6257 configuration to your "File transfer protocols" section:
6259 Name Program Name U/D FullScr IO-Red. Multi
6260 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
6261 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
6267 Starting at version 0.9.2, U-Boot supports NetBSD both as host
6268 (build U-Boot) and target system (boots NetBSD/mpc8xx).
6270 Building requires a cross environment; it is known to work on
6271 NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
6272 need gmake since the Makefiles are not compatible with BSD make).
6273 Note that the cross-powerpc package does not install include files;
6274 attempting to build U-Boot will fail because <machine/ansi.h> is
6275 missing. This file has to be installed and patched manually:
6277 # cd /usr/pkg/cross/powerpc-netbsd/include
6279 # ln -s powerpc machine
6280 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
6281 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
6283 Native builds *don't* work due to incompatibilities between native
6284 and U-Boot include files.
6286 Booting assumes that (the first part of) the image booted is a
6287 stage-2 loader which in turn loads and then invokes the kernel
6288 proper. Loader sources will eventually appear in the NetBSD source
6289 tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
6290 meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz
6293 Implementation Internals:
6294 =========================
6296 The following is not intended to be a complete description of every
6297 implementation detail. However, it should help to understand the
6298 inner workings of U-Boot and make it easier to port it to custom
6302 Initial Stack, Global Data:
6303 ---------------------------
6305 The implementation of U-Boot is complicated by the fact that U-Boot
6306 starts running out of ROM (flash memory), usually without access to
6307 system RAM (because the memory controller is not initialized yet).
6308 This means that we don't have writable Data or BSS segments, and BSS
6309 is not initialized as zero. To be able to get a C environment working
6310 at all, we have to allocate at least a minimal stack. Implementation
6311 options for this are defined and restricted by the CPU used: Some CPU
6312 models provide on-chip memory (like the IMMR area on MPC8xx and
6313 MPC826x processors), on others (parts of) the data cache can be
6314 locked as (mis-) used as memory, etc.
6316 Chris Hallinan posted a good summary of these issues to the
6317 U-Boot mailing list:
6319 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
6320 From: "Chris Hallinan" <clh@net1plus.com>
6321 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
6324 Correct me if I'm wrong, folks, but the way I understand it
6325 is this: Using DCACHE as initial RAM for Stack, etc, does not
6326 require any physical RAM backing up the cache. The cleverness
6327 is that the cache is being used as a temporary supply of
6328 necessary storage before the SDRAM controller is setup. It's
6329 beyond the scope of this list to explain the details, but you
6330 can see how this works by studying the cache architecture and
6331 operation in the architecture and processor-specific manuals.
6333 OCM is On Chip Memory, which I believe the 405GP has 4K. It
6334 is another option for the system designer to use as an
6335 initial stack/RAM area prior to SDRAM being available. Either
6336 option should work for you. Using CS 4 should be fine if your
6337 board designers haven't used it for something that would
6338 cause you grief during the initial boot! It is frequently not
6341 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere
6342 with your processor/board/system design. The default value
6343 you will find in any recent u-boot distribution in
6344 walnut.h should work for you. I'd set it to a value larger
6345 than your SDRAM module. If you have a 64MB SDRAM module, set
6346 it above 400_0000. Just make sure your board has no resources
6347 that are supposed to respond to that address! That code in
6348 start.S has been around a while and should work as is when
6349 you get the config right.
6354 It is essential to remember this, since it has some impact on the C
6355 code for the initialization procedures:
6357 * Initialized global data (data segment) is read-only. Do not attempt
6360 * Do not use any uninitialized global data (or implicitly initialized
6361 as zero data - BSS segment) at all - this is undefined, initiali-
6362 zation is performed later (when relocating to RAM).
6364 * Stack space is very limited. Avoid big data buffers or things like
6367 Having only the stack as writable memory limits means we cannot use
6368 normal global data to share information between the code. But it
6369 turned out that the implementation of U-Boot can be greatly
6370 simplified by making a global data structure (gd_t) available to all
6371 functions. We could pass a pointer to this data as argument to _all_
6372 functions, but this would bloat the code. Instead we use a feature of
6373 the GCC compiler (Global Register Variables) to share the data: we
6374 place a pointer (gd) to the global data into a register which we
6375 reserve for this purpose.
6377 When choosing a register for such a purpose we are restricted by the
6378 relevant (E)ABI specifications for the current architecture, and by
6379 GCC's implementation.
6381 For PowerPC, the following registers have specific use:
6383 R2: reserved for system use
6384 R3-R4: parameter passing and return values
6385 R5-R10: parameter passing
6386 R13: small data area pointer
6390 (U-Boot also uses R12 as internal GOT pointer. r12
6391 is a volatile register so r12 needs to be reset when
6392 going back and forth between asm and C)
6394 ==> U-Boot will use R2 to hold a pointer to the global data
6396 Note: on PPC, we could use a static initializer (since the
6397 address of the global data structure is known at compile time),
6398 but it turned out that reserving a register results in somewhat
6399 smaller code - although the code savings are not that big (on
6400 average for all boards 752 bytes for the whole U-Boot image,
6401 624 text + 127 data).
6403 On Blackfin, the normal C ABI (except for P3) is followed as documented here:
6404 http://docs.blackfin.uclinux.org/doku.php?id=application_binary_interface
6406 ==> U-Boot will use P3 to hold a pointer to the global data
6408 On ARM, the following registers are used:
6410 R0: function argument word/integer result
6411 R1-R3: function argument word
6412 R9: platform specific
6413 R10: stack limit (used only if stack checking is enabled)
6414 R11: argument (frame) pointer
6415 R12: temporary workspace
6418 R15: program counter
6420 ==> U-Boot will use R9 to hold a pointer to the global data
6422 Note: on ARM, only R_ARM_RELATIVE relocations are supported.
6424 On Nios II, the ABI is documented here:
6425 http://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf
6427 ==> U-Boot will use gp to hold a pointer to the global data
6429 Note: on Nios II, we give "-G0" option to gcc and don't use gp
6430 to access small data sections, so gp is free.
6432 On NDS32, the following registers are used:
6434 R0-R1: argument/return
6436 R15: temporary register for assembler
6437 R16: trampoline register
6438 R28: frame pointer (FP)
6439 R29: global pointer (GP)
6440 R30: link register (LP)
6441 R31: stack pointer (SP)
6442 PC: program counter (PC)
6444 ==> U-Boot will use R10 to hold a pointer to the global data
6446 NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope,
6447 or current versions of GCC may "optimize" the code too much.
6452 U-Boot runs in system state and uses physical addresses, i.e. the
6453 MMU is not used either for address mapping nor for memory protection.
6455 The available memory is mapped to fixed addresses using the memory
6456 controller. In this process, a contiguous block is formed for each
6457 memory type (Flash, SDRAM, SRAM), even when it consists of several
6458 physical memory banks.
6460 U-Boot is installed in the first 128 kB of the first Flash bank (on
6461 TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
6462 booting and sizing and initializing DRAM, the code relocates itself
6463 to the upper end of DRAM. Immediately below the U-Boot code some
6464 memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN
6465 configuration setting]. Below that, a structure with global Board
6466 Info data is placed, followed by the stack (growing downward).
6468 Additionally, some exception handler code is copied to the low 8 kB
6469 of DRAM (0x00000000 ... 0x00001FFF).
6471 So a typical memory configuration with 16 MB of DRAM could look like
6474 0x0000 0000 Exception Vector code
6477 0x0000 2000 Free for Application Use
6483 0x00FB FF20 Monitor Stack (Growing downward)
6484 0x00FB FFAC Board Info Data and permanent copy of global data
6485 0x00FC 0000 Malloc Arena
6488 0x00FE 0000 RAM Copy of Monitor Code
6489 ... eventually: LCD or video framebuffer
6490 ... eventually: pRAM (Protected RAM - unchanged by reset)
6491 0x00FF FFFF [End of RAM]
6494 System Initialization:
6495 ----------------------
6497 In the reset configuration, U-Boot starts at the reset entry point
6498 (on most PowerPC systems at address 0x00000100). Because of the reset
6499 configuration for CS0# this is a mirror of the on board Flash memory.
6500 To be able to re-map memory U-Boot then jumps to its link address.
6501 To be able to implement the initialization code in C, a (small!)
6502 initial stack is set up in the internal Dual Ported RAM (in case CPUs
6503 which provide such a feature like MPC8xx or MPC8260), or in a locked
6504 part of the data cache. After that, U-Boot initializes the CPU core,
6505 the caches and the SIU.
6507 Next, all (potentially) available memory banks are mapped using a
6508 preliminary mapping. For example, we put them on 512 MB boundaries
6509 (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
6510 on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
6511 programmed for SDRAM access. Using the temporary configuration, a
6512 simple memory test is run that determines the size of the SDRAM
6515 When there is more than one SDRAM bank, and the banks are of
6516 different size, the largest is mapped first. For equal size, the first
6517 bank (CS2#) is mapped first. The first mapping is always for address
6518 0x00000000, with any additional banks following immediately to create
6519 contiguous memory starting from 0.
6521 Then, the monitor installs itself at the upper end of the SDRAM area
6522 and allocates memory for use by malloc() and for the global Board
6523 Info data; also, the exception vector code is copied to the low RAM
6524 pages, and the final stack is set up.
6526 Only after this relocation will you have a "normal" C environment;
6527 until that you are restricted in several ways, mostly because you are
6528 running from ROM, and because the code will have to be relocated to a
6532 U-Boot Porting Guide:
6533 ----------------------
6535 [Based on messages by Jerry Van Baren in the U-Boot-Users mailing
6539 int main(int argc, char *argv[])
6541 sighandler_t no_more_time;
6543 signal(SIGALRM, no_more_time);
6544 alarm(PROJECT_DEADLINE - toSec (3 * WEEK));
6546 if (available_money > available_manpower) {
6547 Pay consultant to port U-Boot;
6551 Download latest U-Boot source;
6553 Subscribe to u-boot mailing list;
6556 email("Hi, I am new to U-Boot, how do I get started?");
6559 Read the README file in the top level directory;
6560 Read http://www.denx.de/twiki/bin/view/DULG/Manual;
6561 Read applicable doc/*.README;
6562 Read the source, Luke;
6563 /* find . -name "*.[chS]" | xargs grep -i <keyword> */
6566 if (available_money > toLocalCurrency ($2500))
6569 Add a lot of aggravation and time;
6571 if (a similar board exists) { /* hopefully... */
6572 cp -a board/<similar> board/<myboard>
6573 cp include/configs/<similar>.h include/configs/<myboard>.h
6575 Create your own board support subdirectory;
6576 Create your own board include/configs/<myboard>.h file;
6578 Edit new board/<myboard> files
6579 Edit new include/configs/<myboard>.h
6584 Add / modify source code;
6588 email("Hi, I am having problems...");
6590 Send patch file to the U-Boot email list;
6591 if (reasonable critiques)
6592 Incorporate improvements from email list code review;
6594 Defend code as written;
6600 void no_more_time (int sig)
6609 All contributions to U-Boot should conform to the Linux kernel
6610 coding style; see the file "Documentation/CodingStyle" and the script
6611 "scripts/Lindent" in your Linux kernel source directory.
6613 Source files originating from a different project (for example the
6614 MTD subsystem) are generally exempt from these guidelines and are not
6615 reformatted to ease subsequent migration to newer versions of those
6618 Please note that U-Boot is implemented in C (and to some small parts in
6619 Assembler); no C++ is used, so please do not use C++ style comments (//)
6622 Please also stick to the following formatting rules:
6623 - remove any trailing white space
6624 - use TAB characters for indentation and vertical alignment, not spaces
6625 - make sure NOT to use DOS '\r\n' line feeds
6626 - do not add more than 2 consecutive empty lines to source files
6627 - do not add trailing empty lines to source files
6629 Submissions which do not conform to the standards may be returned
6630 with a request to reformat the changes.
6636 Since the number of patches for U-Boot is growing, we need to
6637 establish some rules. Submissions which do not conform to these rules
6638 may be rejected, even when they contain important and valuable stuff.
6640 Please see http://www.denx.de/wiki/U-Boot/Patches for details.
6642 Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>;
6643 see http://lists.denx.de/mailman/listinfo/u-boot
6645 When you send a patch, please include the following information with
6648 * For bug fixes: a description of the bug and how your patch fixes
6649 this bug. Please try to include a way of demonstrating that the
6650 patch actually fixes something.
6652 * For new features: a description of the feature and your
6655 * A CHANGELOG entry as plaintext (separate from the patch)
6657 * For major contributions, your entry to the CREDITS file
6659 * When you add support for a new board, don't forget to add a
6660 maintainer e-mail address to the boards.cfg file, too.
6662 * If your patch adds new configuration options, don't forget to
6663 document these in the README file.
6665 * The patch itself. If you are using git (which is *strongly*
6666 recommended) you can easily generate the patch using the
6667 "git format-patch". If you then use "git send-email" to send it to
6668 the U-Boot mailing list, you will avoid most of the common problems
6669 with some other mail clients.
6671 If you cannot use git, use "diff -purN OLD NEW". If your version of
6672 diff does not support these options, then get the latest version of
6675 The current directory when running this command shall be the parent
6676 directory of the U-Boot source tree (i. e. please make sure that
6677 your patch includes sufficient directory information for the
6680 We prefer patches as plain text. MIME attachments are discouraged,
6681 and compressed attachments must not be used.
6683 * If one logical set of modifications affects or creates several
6684 files, all these changes shall be submitted in a SINGLE patch file.
6686 * Changesets that contain different, unrelated modifications shall be
6687 submitted as SEPARATE patches, one patch per changeset.
6692 * Before sending the patch, run the MAKEALL script on your patched
6693 source tree and make sure that no errors or warnings are reported
6694 for any of the boards.
6696 * Keep your modifications to the necessary minimum: A patch
6697 containing several unrelated changes or arbitrary reformats will be
6698 returned with a request to re-formatting / split it.
6700 * If you modify existing code, make sure that your new code does not
6701 add to the memory footprint of the code ;-) Small is beautiful!
6702 When adding new features, these should compile conditionally only
6703 (using #ifdef), and the resulting code with the new feature
6704 disabled must not need more memory than the old code without your
6707 * Remember that there is a size limit of 100 kB per message on the
6708 u-boot mailing list. Bigger patches will be moderated. If they are
6709 reasonable and not too big, they will be acknowledged. But patches
6710 bigger than the size limit should be avoided.
projects / karo-tx-uboot.git / blob