2 # (C) Copyright 2000 - 2013
3 # Wolfgang Denk, DENX Software Engineering, wd@denx.de.
5 # SPDX-License-Identifier: GPL-2.0+
11 This directory contains the source code for U-Boot, a boot loader for
12 Embedded boards based on PowerPC, ARM, MIPS and several other
13 processors, which can be installed in a boot ROM and used to
14 initialize and test the hardware or to download and run application
17 The development of U-Boot is closely related to Linux: some parts of
18 the source code originate in the Linux source tree, we have some
19 header files in common, and special provision has been made to
20 support booting of Linux images.
22 Some attention has been paid to make this software easily
23 configurable and extendable. For instance, all monitor commands are
24 implemented with the same call interface, so that it's very easy to
25 add new commands. Also, instead of permanently adding rarely used
26 code (for instance hardware test utilities) to the monitor, you can
27 load and run it dynamically.
33 In general, all boards for which a configuration option exists in the
34 Makefile have been tested to some extent and can be considered
35 "working". In fact, many of them are used in production systems.
37 In case of problems see the CHANGELOG and CREDITS files to find out
38 who contributed the specific port. The boards.cfg file lists board
41 Note: There is no CHANGELOG file in the actual U-Boot source tree;
42 it can be created dynamically from the Git log using:
50 In case you have questions about, problems with or contributions for
51 U-Boot you should send a message to the U-Boot mailing list at
52 <u-boot@lists.denx.de>. There is also an archive of previous traffic
53 on the mailing list - please search the archive before asking FAQ's.
54 Please see http://lists.denx.de/pipermail/u-boot and
55 http://dir.gmane.org/gmane.comp.boot-loaders.u-boot
58 Where to get source code:
59 =========================
61 The U-Boot source code is maintained in the git repository at
62 git://www.denx.de/git/u-boot.git ; you can browse it online at
63 http://www.denx.de/cgi-bin/gitweb.cgi?p=u-boot.git;a=summary
65 The "snapshot" links on this page allow you to download tarballs of
66 any version you might be interested in. Official releases are also
67 available for FTP download from the ftp://ftp.denx.de/pub/u-boot/
70 Pre-built (and tested) images are available from
71 ftp://ftp.denx.de/pub/u-boot/images/
77 - start from 8xxrom sources
78 - create PPCBoot project (http://sourceforge.net/projects/ppcboot)
80 - make it easier to add custom boards
81 - make it possible to add other [PowerPC] CPUs
82 - extend functions, especially:
83 * Provide extended interface to Linux boot loader
86 * PCMCIA / CompactFlash / ATA disk / SCSI ... boot
87 - create ARMBoot project (http://sourceforge.net/projects/armboot)
88 - add other CPU families (starting with ARM)
89 - create U-Boot project (http://sourceforge.net/projects/u-boot)
90 - current project page: see http://www.denx.de/wiki/U-Boot
96 The "official" name of this project is "Das U-Boot". The spelling
97 "U-Boot" shall be used in all written text (documentation, comments
98 in source files etc.). Example:
100 This is the README file for the U-Boot project.
102 File names etc. shall be based on the string "u-boot". Examples:
104 include/asm-ppc/u-boot.h
106 #include <asm/u-boot.h>
108 Variable names, preprocessor constants etc. shall be either based on
109 the string "u_boot" or on "U_BOOT". Example:
111 U_BOOT_VERSION u_boot_logo
112 IH_OS_U_BOOT u_boot_hush_start
118 Starting with the release in October 2008, the names of the releases
119 were changed from numerical release numbers without deeper meaning
120 into a time stamp based numbering. Regular releases are identified by
121 names consisting of the calendar year and month of the release date.
122 Additional fields (if present) indicate release candidates or bug fix
123 releases in "stable" maintenance trees.
126 U-Boot v2009.11 - Release November 2009
127 U-Boot v2009.11.1 - Release 1 in version November 2009 stable tree
128 U-Boot v2010.09-rc1 - Release candiate 1 for September 2010 release
134 /arch Architecture specific files
135 /arc Files generic to ARC architecture
136 /cpu CPU specific files
137 /arc700 Files specific to ARC 700 CPUs
138 /lib Architecture specific library files
139 /arm Files generic to ARM architecture
140 /cpu CPU specific files
141 /arm720t Files specific to ARM 720 CPUs
142 /arm920t Files specific to ARM 920 CPUs
143 /at91 Files specific to Atmel AT91RM9200 CPU
144 /imx Files specific to Freescale MC9328 i.MX CPUs
145 /s3c24x0 Files specific to Samsung S3C24X0 CPUs
146 /arm926ejs Files specific to ARM 926 CPUs
147 /arm1136 Files specific to ARM 1136 CPUs
148 /pxa Files specific to Intel XScale PXA CPUs
149 /sa1100 Files specific to Intel StrongARM SA1100 CPUs
150 /lib Architecture specific library files
151 /avr32 Files generic to AVR32 architecture
152 /cpu CPU specific files
153 /lib Architecture specific library files
154 /blackfin Files generic to Analog Devices Blackfin architecture
155 /cpu CPU specific files
156 /lib Architecture specific library files
157 /m68k Files generic to m68k architecture
158 /cpu CPU specific files
159 /mcf52x2 Files specific to Freescale ColdFire MCF52x2 CPUs
160 /mcf5227x Files specific to Freescale ColdFire MCF5227x CPUs
161 /mcf532x Files specific to Freescale ColdFire MCF5329 CPUs
162 /mcf5445x Files specific to Freescale ColdFire MCF5445x CPUs
163 /mcf547x_8x Files specific to Freescale ColdFire MCF547x_8x CPUs
164 /lib Architecture specific library files
165 /microblaze Files generic to microblaze architecture
166 /cpu CPU specific files
167 /lib Architecture specific library files
168 /mips Files generic to MIPS architecture
169 /cpu CPU specific files
170 /mips32 Files specific to MIPS32 CPUs
171 /mips64 Files specific to MIPS64 CPUs
172 /lib Architecture specific library files
173 /nds32 Files generic to NDS32 architecture
174 /cpu CPU specific files
175 /n1213 Files specific to Andes Technology N1213 CPUs
176 /lib Architecture specific library files
177 /nios2 Files generic to Altera NIOS2 architecture
178 /cpu CPU specific files
179 /lib Architecture specific library files
180 /openrisc Files generic to OpenRISC architecture
181 /cpu CPU specific files
182 /lib Architecture specific library files
183 /powerpc Files generic to PowerPC architecture
184 /cpu CPU specific files
185 /mpc5xx Files specific to Freescale MPC5xx CPUs
186 /mpc5xxx Files specific to Freescale MPC5xxx CPUs
187 /mpc8xx Files specific to Freescale MPC8xx CPUs
188 /mpc8260 Files specific to Freescale MPC8260 CPUs
189 /mpc85xx Files specific to Freescale MPC85xx CPUs
190 /ppc4xx Files specific to AMCC PowerPC 4xx CPUs
191 /lib Architecture specific library files
192 /sh Files generic to SH architecture
193 /cpu CPU specific files
194 /sh2 Files specific to sh2 CPUs
195 /sh3 Files specific to sh3 CPUs
196 /sh4 Files specific to sh4 CPUs
197 /lib Architecture specific library files
198 /sparc Files generic to SPARC architecture
199 /cpu CPU specific files
200 /leon2 Files specific to Gaisler LEON2 SPARC CPU
201 /leon3 Files specific to Gaisler LEON3 SPARC CPU
202 /lib Architecture specific library files
203 /x86 Files generic to x86 architecture
204 /cpu CPU specific files
205 /lib Architecture specific library files
206 /api Machine/arch independent API for external apps
207 /board Board dependent files
208 /common Misc architecture independent functions
209 /disk Code for disk drive partition handling
210 /doc Documentation (don't expect too much)
211 /drivers Commonly used device drivers
212 /dts Contains Makefile for building internal U-Boot fdt.
213 /examples Example code for standalone applications, etc.
214 /fs Filesystem code (cramfs, ext2, jffs2, etc.)
215 /include Header Files
216 /lib Files generic to all architectures
217 /libfdt Library files to support flattened device trees
218 /lzma Library files to support LZMA decompression
219 /lzo Library files to support LZO decompression
221 /post Power On Self Test
222 /spl Secondary Program Loader framework
223 /tools Tools to build S-Record or U-Boot images, etc.
225 Software Configuration:
226 =======================
228 Configuration is usually done using C preprocessor defines; the
229 rationale behind that is to avoid dead code whenever possible.
231 There are two classes of configuration variables:
233 * Configuration _OPTIONS_:
234 These are selectable by the user and have names beginning with
237 * Configuration _SETTINGS_:
238 These depend on the hardware etc. and should not be meddled with if
239 you don't know what you're doing; they have names beginning with
242 Later we will add a configuration tool - probably similar to or even
243 identical to what's used for the Linux kernel. Right now, we have to
244 do the configuration by hand, which means creating some symbolic
245 links and editing some configuration files. We use the TQM8xxL boards
249 Selection of Processor Architecture and Board Type:
250 ---------------------------------------------------
252 For all supported boards there are ready-to-use default
253 configurations available; just type "make <board_name>_defconfig".
255 Example: For a TQM823L module type:
258 make TQM823L_defconfig
260 For the Cogent platform, you need to specify the CPU type as well;
261 e.g. "make cogent_mpc8xx_defconfig". And also configure the cogent
262 directory according to the instructions in cogent/README.
268 U-Boot can be built natively to run on a Linux host using the 'sandbox'
269 board. This allows feature development which is not board- or architecture-
270 specific to be undertaken on a native platform. The sandbox is also used to
271 run some of U-Boot's tests.
273 See board/sandbox/README.sandbox for more details.
276 Board Initialisation Flow:
277 --------------------------
279 This is the intended start-up flow for boards. This should apply for both
280 SPL and U-Boot proper (i.e. they both follow the same rules). At present SPL
281 mostly uses a separate code path, but the funtion names and roles of each
282 function are the same. Some boards or architectures may not conform to this.
283 At least most ARM boards which use CONFIG_SPL_FRAMEWORK conform to this.
285 Execution starts with start.S with three functions called during init after
286 that. The purpose and limitations of each is described below.
289 - purpose: essential init to permit execution to reach board_init_f()
290 - no global_data or BSS
291 - there is no stack (ARMv7 may have one but it will soon be removed)
292 - must not set up SDRAM or use console
293 - must only do the bare minimum to allow execution to continue to
295 - this is almost never needed
296 - return normally from this function
299 - purpose: set up the machine ready for running board_init_r():
300 i.e. SDRAM and serial UART
301 - global_data is available
303 - BSS is not available, so you cannot use global/static variables,
304 only stack variables and global_data
306 Non-SPL-specific notes:
307 - dram_init() is called to set up DRAM. If already done in SPL this
311 - you can override the entire board_init_f() function with your own
313 - preloader_console_init() can be called here in extremis
314 - should set up SDRAM, and anything needed to make the UART work
315 - these is no need to clear BSS, it will be done by crt0.S
316 - must return normally from this function (don't call board_init_r()
319 Here the BSS is cleared. For SPL, if CONFIG_SPL_STACK_R is defined, then at
320 this point the stack and global_data are relocated to below
321 CONFIG_SPL_STACK_R_ADDR. For non-SPL, U-Boot is relocated to run at the top of
325 - purpose: main execution, common code
326 - global_data is available
328 - BSS is available, all static/global variables can be used
329 - execution eventually continues to main_loop()
331 Non-SPL-specific notes:
332 - U-Boot is relocated to the top of memory and is now running from
336 - stack is optionally in SDRAM, if CONFIG_SPL_STACK_R is defined and
337 CONFIG_SPL_STACK_R_ADDR points into SDRAM
338 - preloader_console_init() can be called here - typically this is
339 done by defining CONFIG_SPL_BOARD_INIT and then supplying a
340 spl_board_init() function containing this call
341 - loads U-Boot or (in falcon mode) Linux
345 Configuration Options:
346 ----------------------
348 Configuration depends on the combination of board and CPU type; all
349 such information is kept in a configuration file
350 "include/configs/<board_name>.h".
352 Example: For a TQM823L module, all configuration settings are in
353 "include/configs/TQM823L.h".
356 Many of the options are named exactly as the corresponding Linux
357 kernel configuration options. The intention is to make it easier to
358 build a config tool - later.
361 The following options need to be configured:
363 - CPU Type: Define exactly one, e.g. CONFIG_MPC85XX.
365 - Board Type: Define exactly one, e.g. CONFIG_MPC8540ADS.
367 - CPU Daughterboard Type: (if CONFIG_ATSTK1000 is defined)
368 Define exactly one, e.g. CONFIG_ATSTK1002
370 - CPU Module Type: (if CONFIG_COGENT is defined)
371 Define exactly one of
373 --- FIXME --- not tested yet:
374 CONFIG_CMA286_60, CONFIG_CMA286_21, CONFIG_CMA286_60P,
375 CONFIG_CMA287_23, CONFIG_CMA287_50
377 - Motherboard Type: (if CONFIG_COGENT is defined)
378 Define exactly one of
379 CONFIG_CMA101, CONFIG_CMA102
381 - Motherboard I/O Modules: (if CONFIG_COGENT is defined)
382 Define one or more of
385 - Motherboard Options: (if CONFIG_CMA101 or CONFIG_CMA102 are defined)
386 Define one or more of
387 CONFIG_LCD_HEARTBEAT - update a character position on
388 the LCD display every second with
391 - Marvell Family Member
392 CONFIG_SYS_MVFS - define it if you want to enable
393 multiple fs option at one time
394 for marvell soc family
396 - 8xx CPU Options: (if using an MPC8xx CPU)
397 CONFIG_8xx_GCLK_FREQ - deprecated: CPU clock if
398 get_gclk_freq() cannot work
399 e.g. if there is no 32KHz
400 reference PIT/RTC clock
401 CONFIG_8xx_OSCLK - PLL input clock (either EXTCLK
404 - 859/866/885 CPU options: (if using a MPC859 or MPC866 or MPC885 CPU):
405 CONFIG_SYS_8xx_CPUCLK_MIN
406 CONFIG_SYS_8xx_CPUCLK_MAX
407 CONFIG_8xx_CPUCLK_DEFAULT
408 See doc/README.MPC866
410 CONFIG_SYS_MEASURE_CPUCLK
412 Define this to measure the actual CPU clock instead
413 of relying on the correctness of the configured
414 values. Mostly useful for board bringup to make sure
415 the PLL is locked at the intended frequency. Note
416 that this requires a (stable) reference clock (32 kHz
417 RTC clock or CONFIG_SYS_8XX_XIN)
419 CONFIG_SYS_DELAYED_ICACHE
421 Define this option if you want to enable the
422 ICache only when Code runs from RAM.
427 Specifies that the core is a 64-bit PowerPC implementation (implements
428 the "64" category of the Power ISA). This is necessary for ePAPR
429 compliance, among other possible reasons.
431 CONFIG_SYS_FSL_TBCLK_DIV
433 Defines the core time base clock divider ratio compared to the
434 system clock. On most PQ3 devices this is 8, on newer QorIQ
435 devices it can be 16 or 32. The ratio varies from SoC to Soc.
437 CONFIG_SYS_FSL_PCIE_COMPAT
439 Defines the string to utilize when trying to match PCIe device
440 tree nodes for the given platform.
442 CONFIG_SYS_PPC_E500_DEBUG_TLB
444 Enables a temporary TLB entry to be used during boot to work
445 around limitations in e500v1 and e500v2 external debugger
446 support. This reduces the portions of the boot code where
447 breakpoints and single stepping do not work. The value of this
448 symbol should be set to the TLB1 entry to be used for this
451 CONFIG_SYS_FSL_ERRATUM_A004510
453 Enables a workaround for erratum A004510. If set,
454 then CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV and
455 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY must be set.
457 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV
458 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV2 (optional)
460 Defines one or two SoC revisions (low 8 bits of SVR)
461 for which the A004510 workaround should be applied.
463 The rest of SVR is either not relevant to the decision
464 of whether the erratum is present (e.g. p2040 versus
465 p2041) or is implied by the build target, which controls
466 whether CONFIG_SYS_FSL_ERRATUM_A004510 is set.
468 See Freescale App Note 4493 for more information about
471 CONFIG_A003399_NOR_WORKAROUND
472 Enables a workaround for IFC erratum A003399. It is only
473 required during NOR boot.
475 CONFIG_A008044_WORKAROUND
476 Enables a workaround for T1040/T1042 erratum A008044. It is only
477 required during NAND boot and valid for Rev 1.0 SoC revision
479 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY
481 This is the value to write into CCSR offset 0x18600
482 according to the A004510 workaround.
484 CONFIG_SYS_FSL_DSP_DDR_ADDR
485 This value denotes start offset of DDR memory which is
486 connected exclusively to the DSP cores.
488 CONFIG_SYS_FSL_DSP_M2_RAM_ADDR
489 This value denotes start offset of M2 memory
490 which is directly connected to the DSP core.
492 CONFIG_SYS_FSL_DSP_M3_RAM_ADDR
493 This value denotes start offset of M3 memory which is directly
494 connected to the DSP core.
496 CONFIG_SYS_FSL_DSP_CCSRBAR_DEFAULT
497 This value denotes start offset of DSP CCSR space.
499 CONFIG_SYS_FSL_SINGLE_SOURCE_CLK
500 Single Source Clock is clocking mode present in some of FSL SoC's.
501 In this mode, a single differential clock is used to supply
502 clocks to the sysclock, ddrclock and usbclock.
504 CONFIG_SYS_CPC_REINIT_F
505 This CONFIG is defined when the CPC is configured as SRAM at the
506 time of U-boot entry and is required to be re-initialized.
509 Indicates this SoC supports deep sleep feature. If deep sleep is
510 supported, core will start to execute uboot when wakes up.
512 - Generic CPU options:
513 CONFIG_SYS_GENERIC_GLOBAL_DATA
514 Defines global data is initialized in generic board board_init_f().
515 If this macro is defined, global data is created and cleared in
516 generic board board_init_f(). Without this macro, architecture/board
517 should initialize global data before calling board_init_f().
519 CONFIG_SYS_BIG_ENDIAN, CONFIG_SYS_LITTLE_ENDIAN
521 Defines the endianess of the CPU. Implementation of those
522 values is arch specific.
525 Freescale DDR driver in use. This type of DDR controller is
526 found in mpc83xx, mpc85xx, mpc86xx as well as some ARM core
529 CONFIG_SYS_FSL_DDR_ADDR
530 Freescale DDR memory-mapped register base.
532 CONFIG_SYS_FSL_DDR_EMU
533 Specify emulator support for DDR. Some DDR features such as
534 deskew training are not available.
536 CONFIG_SYS_FSL_DDRC_GEN1
537 Freescale DDR1 controller.
539 CONFIG_SYS_FSL_DDRC_GEN2
540 Freescale DDR2 controller.
542 CONFIG_SYS_FSL_DDRC_GEN3
543 Freescale DDR3 controller.
545 CONFIG_SYS_FSL_DDRC_GEN4
546 Freescale DDR4 controller.
548 CONFIG_SYS_FSL_DDRC_ARM_GEN3
549 Freescale DDR3 controller for ARM-based SoCs.
552 Board config to use DDR1. It can be enabled for SoCs with
553 Freescale DDR1 or DDR2 controllers, depending on the board
557 Board config to use DDR2. It can be eanbeld for SoCs with
558 Freescale DDR2 or DDR3 controllers, depending on the board
562 Board config to use DDR3. It can be enabled for SoCs with
563 Freescale DDR3 or DDR3L controllers.
566 Board config to use DDR3L. It can be enabled for SoCs with
570 Board config to use DDR4. It can be enabled for SoCs with
573 CONFIG_SYS_FSL_IFC_BE
574 Defines the IFC controller register space as Big Endian
576 CONFIG_SYS_FSL_IFC_LE
577 Defines the IFC controller register space as Little Endian
579 CONFIG_SYS_FSL_PBL_PBI
580 It enables addition of RCW (Power on reset configuration) in built image.
581 Please refer doc/README.pblimage for more details
583 CONFIG_SYS_FSL_PBL_RCW
584 It adds PBI(pre-boot instructions) commands in u-boot build image.
585 PBI commands can be used to configure SoC before it starts the execution.
586 Please refer doc/README.pblimage for more details
589 It adds a target to create boot binary having SPL binary in PBI format
590 concatenated with u-boot binary.
592 CONFIG_SYS_FSL_DDR_BE
593 Defines the DDR controller register space as Big Endian
595 CONFIG_SYS_FSL_DDR_LE
596 Defines the DDR controller register space as Little Endian
598 CONFIG_SYS_FSL_DDR_SDRAM_BASE_PHY
599 Physical address from the view of DDR controllers. It is the
600 same as CONFIG_SYS_DDR_SDRAM_BASE for all Power SoCs. But
601 it could be different for ARM SoCs.
603 CONFIG_SYS_FSL_DDR_INTLV_256B
604 DDR controller interleaving on 256-byte. This is a special
605 interleaving mode, handled by Dickens for Freescale layerscape
608 CONFIG_SYS_FSL_DDR_MAIN_NUM_CTRLS
609 Number of controllers used as main memory.
611 CONFIG_SYS_FSL_OTHER_DDR_NUM_CTRLS
612 Number of controllers used for other than main memory.
614 CONFIG_SYS_FSL_SEC_BE
615 Defines the SEC controller register space as Big Endian
617 CONFIG_SYS_FSL_SEC_LE
618 Defines the SEC controller register space as Little Endian
620 - Intel Monahans options:
621 CONFIG_SYS_MONAHANS_RUN_MODE_OSC_RATIO
623 Defines the Monahans run mode to oscillator
624 ratio. Valid values are 8, 16, 24, 31. The core
625 frequency is this value multiplied by 13 MHz.
627 CONFIG_SYS_MONAHANS_TURBO_RUN_MODE_RATIO
629 Defines the Monahans turbo mode to oscillator
630 ratio. Valid values are 1 (default if undefined) and
631 2. The core frequency as calculated above is multiplied
635 CONFIG_SYS_INIT_SP_OFFSET
637 Offset relative to CONFIG_SYS_SDRAM_BASE for initial stack
638 pointer. This is needed for the temporary stack before
641 CONFIG_SYS_MIPS_CACHE_MODE
643 Cache operation mode for the MIPS CPU.
644 See also arch/mips/include/asm/mipsregs.h.
646 CONF_CM_CACHABLE_NO_WA
649 CONF_CM_CACHABLE_NONCOHERENT
653 CONF_CM_CACHABLE_ACCELERATED
655 CONFIG_SYS_XWAY_EBU_BOOTCFG
657 Special option for Lantiq XWAY SoCs for booting from NOR flash.
658 See also arch/mips/cpu/mips32/start.S.
660 CONFIG_XWAY_SWAP_BYTES
662 Enable compilation of tools/xway-swap-bytes needed for Lantiq
663 XWAY SoCs for booting from NOR flash. The U-Boot image needs to
664 be swapped if a flash programmer is used.
667 CONFIG_SYS_EXCEPTION_VECTORS_HIGH
669 Select high exception vectors of the ARM core, e.g., do not
670 clear the V bit of the c1 register of CP15.
672 CONFIG_SYS_THUMB_BUILD
674 Use this flag to build U-Boot using the Thumb instruction
675 set for ARM architectures. Thumb instruction set provides
676 better code density. For ARM architectures that support
677 Thumb2 this flag will result in Thumb2 code generated by
680 CONFIG_ARM_ERRATA_716044
681 CONFIG_ARM_ERRATA_742230
682 CONFIG_ARM_ERRATA_743622
683 CONFIG_ARM_ERRATA_751472
684 CONFIG_ARM_ERRATA_794072
685 CONFIG_ARM_ERRATA_761320
687 If set, the workarounds for these ARM errata are applied early
688 during U-Boot startup. Note that these options force the
689 workarounds to be applied; no CPU-type/version detection
690 exists, unlike the similar options in the Linux kernel. Do not
691 set these options unless they apply!
694 CONFIG_TEGRA_SUPPORT_NON_SECURE
696 Support executing U-Boot in non-secure (NS) mode. Certain
697 impossible actions will be skipped if the CPU is in NS mode,
698 such as ARM architectural timer initialization.
701 - Linux Kernel Interface:
704 U-Boot stores all clock information in Hz
705 internally. For binary compatibility with older Linux
706 kernels (which expect the clocks passed in the
707 bd_info data to be in MHz) the environment variable
708 "clocks_in_mhz" can be defined so that U-Boot
709 converts clock data to MHZ before passing it to the
711 When CONFIG_CLOCKS_IN_MHZ is defined, a definition of
712 "clocks_in_mhz=1" is automatically included in the
715 CONFIG_MEMSIZE_IN_BYTES [relevant for MIPS only]
717 When transferring memsize parameter to Linux, some versions
718 expect it to be in bytes, others in MB.
719 Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes.
723 New kernel versions are expecting firmware settings to be
724 passed using flattened device trees (based on open firmware
728 * New libfdt-based support
729 * Adds the "fdt" command
730 * The bootm command automatically updates the fdt
732 OF_CPU - The proper name of the cpus node (only required for
733 MPC512X and MPC5xxx based boards).
734 OF_SOC - The proper name of the soc node (only required for
735 MPC512X and MPC5xxx based boards).
736 OF_TBCLK - The timebase frequency.
737 OF_STDOUT_PATH - The path to the console device
739 boards with QUICC Engines require OF_QE to set UCC MAC
742 CONFIG_OF_BOARD_SETUP
744 Board code has addition modification that it wants to make
745 to the flat device tree before handing it off to the kernel
747 CONFIG_OF_SYSTEM_SETUP
749 Other code has addition modification that it wants to make
750 to the flat device tree before handing it off to the kernel.
751 This causes ft_system_setup() to be called before booting
756 This define fills in the correct boot CPU in the boot
757 param header, the default value is zero if undefined.
761 U-Boot can detect if an IDE device is present or not.
762 If not, and this new config option is activated, U-Boot
763 removes the ATA node from the DTS before booting Linux,
764 so the Linux IDE driver does not probe the device and
765 crash. This is needed for buggy hardware (uc101) where
766 no pull down resistor is connected to the signal IDE5V_DD7.
768 CONFIG_MACH_TYPE [relevant for ARM only][mandatory]
770 This setting is mandatory for all boards that have only one
771 machine type and must be used to specify the machine type
772 number as it appears in the ARM machine registry
773 (see http://www.arm.linux.org.uk/developer/machines/).
774 Only boards that have multiple machine types supported
775 in a single configuration file and the machine type is
776 runtime discoverable, do not have to use this setting.
778 - vxWorks boot parameters:
780 bootvx constructs a valid bootline using the following
781 environments variables: bootfile, ipaddr, serverip, hostname.
782 It loads the vxWorks image pointed bootfile.
784 CONFIG_SYS_VXWORKS_BOOT_DEVICE - The vxworks device name
785 CONFIG_SYS_VXWORKS_MAC_PTR - Ethernet 6 byte MA -address
786 CONFIG_SYS_VXWORKS_SERVERNAME - Name of the server
787 CONFIG_SYS_VXWORKS_BOOT_ADDR - Address of boot parameters
789 CONFIG_SYS_VXWORKS_ADD_PARAMS
791 Add it at the end of the bootline. E.g "u=username pw=secret"
793 Note: If a "bootargs" environment is defined, it will overwride
794 the defaults discussed just above.
796 - Cache Configuration:
797 CONFIG_SYS_ICACHE_OFF - Do not enable instruction cache in U-Boot
798 CONFIG_SYS_DCACHE_OFF - Do not enable data cache in U-Boot
799 CONFIG_SYS_L2CACHE_OFF- Do not enable L2 cache in U-Boot
801 - Cache Configuration for ARM:
802 CONFIG_SYS_L2_PL310 - Enable support for ARM PL310 L2 cache
804 CONFIG_SYS_PL310_BASE - Physical base address of PL310
805 controller register space
810 Define this if you want support for Amba PrimeCell PL010 UARTs.
814 Define this if you want support for Amba PrimeCell PL011 UARTs.
818 If you have Amba PrimeCell PL011 UARTs, set this variable to
819 the clock speed of the UARTs.
823 If you have Amba PrimeCell PL010 or PL011 UARTs on your board,
824 define this to a list of base addresses for each (supported)
825 port. See e.g. include/configs/versatile.h
827 CONFIG_PL011_SERIAL_RLCR
829 Some vendor versions of PL011 serial ports (e.g. ST-Ericsson U8500)
830 have separate receive and transmit line control registers. Set
831 this variable to initialize the extra register.
833 CONFIG_PL011_SERIAL_FLUSH_ON_INIT
835 On some platforms (e.g. U8500) U-Boot is loaded by a second stage
836 boot loader that has already initialized the UART. Define this
837 variable to flush the UART at init time.
839 CONFIG_SERIAL_HW_FLOW_CONTROL
841 Define this variable to enable hw flow control in serial driver.
842 Current user of this option is drivers/serial/nsl16550.c driver
845 Depending on board, define exactly one serial port
846 (like CONFIG_8xx_CONS_SMC1, CONFIG_8xx_CONS_SMC2,
847 CONFIG_8xx_CONS_SCC1, ...), or switch off the serial
848 console by defining CONFIG_8xx_CONS_NONE
850 Note: if CONFIG_8xx_CONS_NONE is defined, the serial
851 port routines must be defined elsewhere
852 (i.e. serial_init(), serial_getc(), ...)
855 Enables console device for a color framebuffer. Needs following
856 defines (cf. smiLynxEM, i8042)
857 VIDEO_FB_LITTLE_ENDIAN graphic memory organisation
859 VIDEO_HW_RECTFILL graphic chip supports
862 VIDEO_HW_BITBLT graphic chip supports
863 bit-blit (cf. smiLynxEM)
864 VIDEO_VISIBLE_COLS visible pixel columns
866 VIDEO_VISIBLE_ROWS visible pixel rows
867 VIDEO_PIXEL_SIZE bytes per pixel
868 VIDEO_DATA_FORMAT graphic data format
869 (0-5, cf. cfb_console.c)
870 VIDEO_FB_ADRS framebuffer address
871 VIDEO_KBD_INIT_FCT keyboard int fct
872 (i.e. i8042_kbd_init())
873 VIDEO_TSTC_FCT test char fct
875 VIDEO_GETC_FCT get char fct
877 CONFIG_CONSOLE_CURSOR cursor drawing on/off
878 (requires blink timer
880 CONFIG_SYS_CONSOLE_BLINK_COUNT blink interval (cf. i8042.c)
881 CONFIG_CONSOLE_TIME display time/date info in
883 (requires CONFIG_CMD_DATE)
884 CONFIG_VIDEO_LOGO display Linux logo in
886 CONFIG_VIDEO_BMP_LOGO use bmp_logo.h instead of
887 linux_logo.h for logo.
888 Requires CONFIG_VIDEO_LOGO
889 CONFIG_CONSOLE_EXTRA_INFO
890 additional board info beside
893 When CONFIG_CFB_CONSOLE_ANSI is defined, console will support
894 a limited number of ANSI escape sequences (cursor control,
895 erase functions and limited graphics rendition control).
897 When CONFIG_CFB_CONSOLE is defined, video console is
898 default i/o. Serial console can be forced with
899 environment 'console=serial'.
901 When CONFIG_SILENT_CONSOLE is defined, all console
902 messages (by U-Boot and Linux!) can be silenced with
903 the "silent" environment variable. See
904 doc/README.silent for more information.
906 CONFIG_SYS_CONSOLE_BG_COL: define the backgroundcolor, default
908 CONFIG_SYS_CONSOLE_FG_COL: define the foregroundcolor, default
912 CONFIG_BAUDRATE - in bps
913 Select one of the baudrates listed in
914 CONFIG_SYS_BAUDRATE_TABLE, see below.
915 CONFIG_SYS_BRGCLK_PRESCALE, baudrate prescale
917 - Console Rx buffer length
918 With CONFIG_SYS_SMC_RXBUFLEN it is possible to define
919 the maximum receive buffer length for the SMC.
920 This option is actual only for 82xx and 8xx possible.
921 If using CONFIG_SYS_SMC_RXBUFLEN also CONFIG_SYS_MAXIDLE
922 must be defined, to setup the maximum idle timeout for
925 - Pre-Console Buffer:
926 Prior to the console being initialised (i.e. serial UART
927 initialised etc) all console output is silently discarded.
928 Defining CONFIG_PRE_CONSOLE_BUFFER will cause U-Boot to
929 buffer any console messages prior to the console being
930 initialised to a buffer of size CONFIG_PRE_CON_BUF_SZ
931 bytes located at CONFIG_PRE_CON_BUF_ADDR. The buffer is
932 a circular buffer, so if more than CONFIG_PRE_CON_BUF_SZ
933 bytes are output before the console is initialised, the
934 earlier bytes are discarded.
936 'Sane' compilers will generate smaller code if
937 CONFIG_PRE_CON_BUF_SZ is a power of 2
939 - Safe printf() functions
940 Define CONFIG_SYS_VSNPRINTF to compile in safe versions of
941 the printf() functions. These are defined in
942 include/vsprintf.h and include snprintf(), vsnprintf() and
943 so on. Code size increase is approximately 300-500 bytes.
944 If this option is not given then these functions will
945 silently discard their buffer size argument - this means
946 you are not getting any overflow checking in this case.
948 - Boot Delay: CONFIG_BOOTDELAY - in seconds
949 Delay before automatically booting the default image;
950 set to -1 to disable autoboot.
951 set to -2 to autoboot with no delay and not check for abort
952 (even when CONFIG_ZERO_BOOTDELAY_CHECK is defined).
954 See doc/README.autoboot for these options that
955 work with CONFIG_BOOTDELAY. None are required.
956 CONFIG_BOOT_RETRY_TIME
957 CONFIG_BOOT_RETRY_MIN
958 CONFIG_AUTOBOOT_KEYED
959 CONFIG_AUTOBOOT_PROMPT
960 CONFIG_AUTOBOOT_DELAY_STR
961 CONFIG_AUTOBOOT_STOP_STR
962 CONFIG_AUTOBOOT_DELAY_STR2
963 CONFIG_AUTOBOOT_STOP_STR2
964 CONFIG_ZERO_BOOTDELAY_CHECK
965 CONFIG_RESET_TO_RETRY
969 Only needed when CONFIG_BOOTDELAY is enabled;
970 define a command string that is automatically executed
971 when no character is read on the console interface
972 within "Boot Delay" after reset.
975 This can be used to pass arguments to the bootm
976 command. The value of CONFIG_BOOTARGS goes into the
977 environment value "bootargs".
979 CONFIG_RAMBOOT and CONFIG_NFSBOOT
980 The value of these goes into the environment as
981 "ramboot" and "nfsboot" respectively, and can be used
982 as a convenience, when switching between booting from
986 CONFIG_BOOTCOUNT_LIMIT
987 Implements a mechanism for detecting a repeating reboot
989 http://www.denx.de/wiki/view/DULG/UBootBootCountLimit
992 If no softreset save registers are found on the hardware
993 "bootcount" is stored in the environment. To prevent a
994 saveenv on all reboots, the environment variable
995 "upgrade_available" is used. If "upgrade_available" is
996 0, "bootcount" is always 0, if "upgrade_available" is
997 1 "bootcount" is incremented in the environment.
998 So the Userspace Applikation must set the "upgrade_available"
999 and "bootcount" variable to 0, if a boot was successfully.
1001 - Pre-Boot Commands:
1004 When this option is #defined, the existence of the
1005 environment variable "preboot" will be checked
1006 immediately before starting the CONFIG_BOOTDELAY
1007 countdown and/or running the auto-boot command resp.
1008 entering interactive mode.
1010 This feature is especially useful when "preboot" is
1011 automatically generated or modified. For an example
1012 see the LWMON board specific code: here "preboot" is
1013 modified when the user holds down a certain
1014 combination of keys on the (special) keyboard when
1017 - Serial Download Echo Mode:
1019 If defined to 1, all characters received during a
1020 serial download (using the "loads" command) are
1021 echoed back. This might be needed by some terminal
1022 emulations (like "cu"), but may as well just take
1023 time on others. This setting #define's the initial
1024 value of the "loads_echo" environment variable.
1026 - Kgdb Serial Baudrate: (if CONFIG_CMD_KGDB is defined)
1027 CONFIG_KGDB_BAUDRATE
1028 Select one of the baudrates listed in
1029 CONFIG_SYS_BAUDRATE_TABLE, see below.
1031 - Monitor Functions:
1032 Monitor commands can be included or excluded
1033 from the build by using the #include files
1034 <config_cmd_all.h> and #undef'ing unwanted
1035 commands, or using <config_cmd_default.h>
1036 and augmenting with additional #define's
1037 for wanted commands.
1039 The default command configuration includes all commands
1040 except those marked below with a "*".
1042 CONFIG_CMD_AES AES 128 CBC encrypt/decrypt
1043 CONFIG_CMD_ASKENV * ask for env variable
1044 CONFIG_CMD_BDI bdinfo
1045 CONFIG_CMD_BEDBUG * Include BedBug Debugger
1046 CONFIG_CMD_BMP * BMP support
1047 CONFIG_CMD_BSP * Board specific commands
1048 CONFIG_CMD_BOOTD bootd
1049 CONFIG_CMD_BOOTI * ARM64 Linux kernel Image support
1050 CONFIG_CMD_CACHE * icache, dcache
1051 CONFIG_CMD_CLK * clock command support
1052 CONFIG_CMD_CONSOLE coninfo
1053 CONFIG_CMD_CRC32 * crc32
1054 CONFIG_CMD_DATE * support for RTC, date/time...
1055 CONFIG_CMD_DHCP * DHCP support
1056 CONFIG_CMD_DIAG * Diagnostics
1057 CONFIG_CMD_DS4510 * ds4510 I2C gpio commands
1058 CONFIG_CMD_DS4510_INFO * ds4510 I2C info command
1059 CONFIG_CMD_DS4510_MEM * ds4510 I2C eeprom/sram commansd
1060 CONFIG_CMD_DS4510_RST * ds4510 I2C rst command
1061 CONFIG_CMD_DTT * Digital Therm and Thermostat
1062 CONFIG_CMD_ECHO echo arguments
1063 CONFIG_CMD_EDITENV edit env variable
1064 CONFIG_CMD_EEPROM * EEPROM read/write support
1065 CONFIG_CMD_ELF * bootelf, bootvx
1066 CONFIG_CMD_ENV_CALLBACK * display details about env callbacks
1067 CONFIG_CMD_ENV_FLAGS * display details about env flags
1068 CONFIG_CMD_ENV_EXISTS * check existence of env variable
1069 CONFIG_CMD_EXPORTENV * export the environment
1070 CONFIG_CMD_EXT2 * ext2 command support
1071 CONFIG_CMD_EXT4 * ext4 command support
1072 CONFIG_CMD_FS_GENERIC * filesystem commands (e.g. load, ls)
1073 that work for multiple fs types
1074 CONFIG_CMD_FS_UUID * Look up a filesystem UUID
1075 CONFIG_CMD_SAVEENV saveenv
1076 CONFIG_CMD_FDC * Floppy Disk Support
1077 CONFIG_CMD_FAT * FAT command support
1078 CONFIG_CMD_FLASH flinfo, erase, protect
1079 CONFIG_CMD_FPGA FPGA device initialization support
1080 CONFIG_CMD_FUSE * Device fuse support
1081 CONFIG_CMD_GETTIME * Get time since boot
1082 CONFIG_CMD_GO * the 'go' command (exec code)
1083 CONFIG_CMD_GREPENV * search environment
1084 CONFIG_CMD_HASH * calculate hash / digest
1085 CONFIG_CMD_HWFLOW * RTS/CTS hw flow control
1086 CONFIG_CMD_I2C * I2C serial bus support
1087 CONFIG_CMD_IDE * IDE harddisk support
1088 CONFIG_CMD_IMI iminfo
1089 CONFIG_CMD_IMLS List all images found in NOR flash
1090 CONFIG_CMD_IMLS_NAND * List all images found in NAND flash
1091 CONFIG_CMD_IMMAP * IMMR dump support
1092 CONFIG_CMD_IOTRACE * I/O tracing for debugging
1093 CONFIG_CMD_IMPORTENV * import an environment
1094 CONFIG_CMD_INI * import data from an ini file into the env
1095 CONFIG_CMD_IRQ * irqinfo
1096 CONFIG_CMD_ITEST Integer/string test of 2 values
1097 CONFIG_CMD_JFFS2 * JFFS2 Support
1098 CONFIG_CMD_KGDB * kgdb
1099 CONFIG_CMD_LDRINFO * ldrinfo (display Blackfin loader)
1100 CONFIG_CMD_LINK_LOCAL * link-local IP address auto-configuration
1102 CONFIG_CMD_LOADB loadb
1103 CONFIG_CMD_LOADS loads
1104 CONFIG_CMD_MD5SUM * print md5 message digest
1105 (requires CONFIG_CMD_MEMORY and CONFIG_MD5)
1106 CONFIG_CMD_MEMINFO * Display detailed memory information
1107 CONFIG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base,
1109 CONFIG_CMD_MEMTEST * mtest
1110 CONFIG_CMD_MISC Misc functions like sleep etc
1111 CONFIG_CMD_MMC * MMC memory mapped support
1112 CONFIG_CMD_MII * MII utility commands
1113 CONFIG_CMD_MTDPARTS * MTD partition support
1114 CONFIG_CMD_NAND * NAND support
1115 CONFIG_CMD_NET bootp, tftpboot, rarpboot
1116 CONFIG_CMD_NFS NFS support
1117 CONFIG_CMD_PCA953X * PCA953x I2C gpio commands
1118 CONFIG_CMD_PCA953X_INFO * PCA953x I2C gpio info command
1119 CONFIG_CMD_PCI * pciinfo
1120 CONFIG_CMD_PCMCIA * PCMCIA support
1121 CONFIG_CMD_PING * send ICMP ECHO_REQUEST to network
1123 CONFIG_CMD_PORTIO * Port I/O
1124 CONFIG_CMD_READ * Read raw data from partition
1125 CONFIG_CMD_REGINFO * Register dump
1126 CONFIG_CMD_RUN run command in env variable
1127 CONFIG_CMD_SANDBOX * sb command to access sandbox features
1128 CONFIG_CMD_SAVES * save S record dump
1129 CONFIG_CMD_SCSI * SCSI Support
1130 CONFIG_CMD_SDRAM * print SDRAM configuration information
1131 (requires CONFIG_CMD_I2C)
1132 CONFIG_CMD_SETGETDCR Support for DCR Register access
1134 CONFIG_CMD_SF * Read/write/erase SPI NOR flash
1135 CONFIG_CMD_SHA1SUM * print sha1 memory digest
1136 (requires CONFIG_CMD_MEMORY)
1137 CONFIG_CMD_SOFTSWITCH * Soft switch setting command for BF60x
1138 CONFIG_CMD_SOURCE "source" command Support
1139 CONFIG_CMD_SPI * SPI serial bus support
1140 CONFIG_CMD_TFTPSRV * TFTP transfer in server mode
1141 CONFIG_CMD_TFTPPUT * TFTP put command (upload)
1142 CONFIG_CMD_TIME * run command and report execution time (ARM specific)
1143 CONFIG_CMD_TIMER * access to the system tick timer
1144 CONFIG_CMD_USB * USB support
1145 CONFIG_CMD_CDP * Cisco Discover Protocol support
1146 CONFIG_CMD_MFSL * Microblaze FSL support
1147 CONFIG_CMD_XIMG Load part of Multi Image
1148 CONFIG_CMD_UUID * Generate random UUID or GUID string
1150 EXAMPLE: If you want all functions except of network
1151 support you can write:
1153 #include "config_cmd_all.h"
1154 #undef CONFIG_CMD_NET
1157 fdt (flattened device tree) command: CONFIG_OF_LIBFDT
1159 Note: Don't enable the "icache" and "dcache" commands
1160 (configuration option CONFIG_CMD_CACHE) unless you know
1161 what you (and your U-Boot users) are doing. Data
1162 cache cannot be enabled on systems like the 8xx or
1163 8260 (where accesses to the IMMR region must be
1164 uncached), and it cannot be disabled on all other
1165 systems where we (mis-) use the data cache to hold an
1166 initial stack and some data.
1169 XXX - this list needs to get updated!
1171 - Regular expression support:
1173 If this variable is defined, U-Boot is linked against
1174 the SLRE (Super Light Regular Expression) library,
1175 which adds regex support to some commands, as for
1176 example "env grep" and "setexpr".
1180 If this variable is defined, U-Boot will use a device tree
1181 to configure its devices, instead of relying on statically
1182 compiled #defines in the board file. This option is
1183 experimental and only available on a few boards. The device
1184 tree is available in the global data as gd->fdt_blob.
1186 U-Boot needs to get its device tree from somewhere. This can
1187 be done using one of the two options below:
1190 If this variable is defined, U-Boot will embed a device tree
1191 binary in its image. This device tree file should be in the
1192 board directory and called <soc>-<board>.dts. The binary file
1193 is then picked up in board_init_f() and made available through
1194 the global data structure as gd->blob.
1197 If this variable is defined, U-Boot will build a device tree
1198 binary. It will be called u-boot.dtb. Architecture-specific
1199 code will locate it at run-time. Generally this works by:
1201 cat u-boot.bin u-boot.dtb >image.bin
1203 and in fact, U-Boot does this for you, creating a file called
1204 u-boot-dtb.bin which is useful in the common case. You can
1205 still use the individual files if you need something more
1210 If this variable is defined, it enables watchdog
1211 support for the SoC. There must be support in the SoC
1212 specific code for a watchdog. For the 8xx and 8260
1213 CPUs, the SIU Watchdog feature is enabled in the SYPCR
1214 register. When supported for a specific SoC is
1215 available, then no further board specific code should
1216 be needed to use it.
1219 When using a watchdog circuitry external to the used
1220 SoC, then define this variable and provide board
1221 specific code for the "hw_watchdog_reset" function.
1223 CONFIG_AT91_HW_WDT_TIMEOUT
1224 specify the timeout in seconds. default 2 seconds.
1227 CONFIG_VERSION_VARIABLE
1228 If this variable is defined, an environment variable
1229 named "ver" is created by U-Boot showing the U-Boot
1230 version as printed by the "version" command.
1231 Any change to this variable will be reverted at the
1236 When CONFIG_CMD_DATE is selected, the type of the RTC
1237 has to be selected, too. Define exactly one of the
1240 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx
1241 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC
1242 CONFIG_RTC_MC13XXX - use MC13783 or MC13892 RTC
1243 CONFIG_RTC_MC146818 - use MC146818 RTC
1244 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC
1245 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC
1246 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC
1247 CONFIG_RTC_DS1339 - use Maxim, Inc. DS1339 RTC
1248 CONFIG_RTC_DS164x - use Dallas DS164x RTC
1249 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC
1250 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC
1251 CONFIG_SYS_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337
1252 CONFIG_SYS_RV3029_TCR - enable trickle charger on
1255 Note that if the RTC uses I2C, then the I2C interface
1256 must also be configured. See I2C Support, below.
1259 CONFIG_PCA953X - use NXP's PCA953X series I2C GPIO
1261 The CONFIG_SYS_I2C_PCA953X_WIDTH option specifies a list of
1262 chip-ngpio pairs that tell the PCA953X driver the number of
1263 pins supported by a particular chip.
1265 Note that if the GPIO device uses I2C, then the I2C interface
1266 must also be configured. See I2C Support, below.
1269 When CONFIG_IO_TRACE is selected, U-Boot intercepts all I/O
1270 accesses and can checksum them or write a list of them out
1271 to memory. See the 'iotrace' command for details. This is
1272 useful for testing device drivers since it can confirm that
1273 the driver behaves the same way before and after a code
1274 change. Currently this is supported on sandbox and arm. To
1275 add support for your architecture, add '#include <iotrace.h>'
1276 to the bottom of arch/<arch>/include/asm/io.h and test.
1278 Example output from the 'iotrace stats' command is below.
1279 Note that if the trace buffer is exhausted, the checksum will
1280 still continue to operate.
1283 Start: 10000000 (buffer start address)
1284 Size: 00010000 (buffer size)
1285 Offset: 00000120 (current buffer offset)
1286 Output: 10000120 (start + offset)
1287 Count: 00000018 (number of trace records)
1288 CRC32: 9526fb66 (CRC32 of all trace records)
1290 - Timestamp Support:
1292 When CONFIG_TIMESTAMP is selected, the timestamp
1293 (date and time) of an image is printed by image
1294 commands like bootm or iminfo. This option is
1295 automatically enabled when you select CONFIG_CMD_DATE .
1297 - Partition Labels (disklabels) Supported:
1298 Zero or more of the following:
1299 CONFIG_MAC_PARTITION Apple's MacOS partition table.
1300 CONFIG_DOS_PARTITION MS Dos partition table, traditional on the
1301 Intel architecture, USB sticks, etc.
1302 CONFIG_ISO_PARTITION ISO partition table, used on CDROM etc.
1303 CONFIG_EFI_PARTITION GPT partition table, common when EFI is the
1304 bootloader. Note 2TB partition limit; see
1306 CONFIG_MTD_PARTITIONS Memory Technology Device partition table.
1308 If IDE or SCSI support is enabled (CONFIG_CMD_IDE or
1309 CONFIG_CMD_SCSI) you must configure support for at
1310 least one non-MTD partition type as well.
1313 CONFIG_IDE_RESET_ROUTINE - this is defined in several
1314 board configurations files but used nowhere!
1316 CONFIG_IDE_RESET - is this is defined, IDE Reset will
1317 be performed by calling the function
1318 ide_set_reset(int reset)
1319 which has to be defined in a board specific file
1324 Set this to enable ATAPI support.
1329 Set this to enable support for disks larger than 137GB
1330 Also look at CONFIG_SYS_64BIT_LBA.
1331 Whithout these , LBA48 support uses 32bit variables and will 'only'
1332 support disks up to 2.1TB.
1334 CONFIG_SYS_64BIT_LBA:
1335 When enabled, makes the IDE subsystem use 64bit sector addresses.
1339 At the moment only there is only support for the
1340 SYM53C8XX SCSI controller; define
1341 CONFIG_SCSI_SYM53C8XX to enable it.
1343 CONFIG_SYS_SCSI_MAX_LUN [8], CONFIG_SYS_SCSI_MAX_SCSI_ID [7] and
1344 CONFIG_SYS_SCSI_MAX_DEVICE [CONFIG_SYS_SCSI_MAX_SCSI_ID *
1345 CONFIG_SYS_SCSI_MAX_LUN] can be adjusted to define the
1346 maximum numbers of LUNs, SCSI ID's and target
1348 CONFIG_SYS_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz)
1350 The environment variable 'scsidevs' is set to the number of
1351 SCSI devices found during the last scan.
1353 - NETWORK Support (PCI):
1355 Support for Intel 8254x/8257x gigabit chips.
1358 Utility code for direct access to the SPI bus on Intel 8257x.
1359 This does not do anything useful unless you set at least one
1360 of CONFIG_CMD_E1000 or CONFIG_E1000_SPI_GENERIC.
1362 CONFIG_E1000_SPI_GENERIC
1363 Allow generic access to the SPI bus on the Intel 8257x, for
1364 example with the "sspi" command.
1367 Management command for E1000 devices. When used on devices
1368 with SPI support you can reprogram the EEPROM from U-Boot.
1370 CONFIG_E1000_FALLBACK_MAC
1371 default MAC for empty EEPROM after production.
1374 Support for Intel 82557/82559/82559ER chips.
1375 Optional CONFIG_EEPRO100_SROM_WRITE enables EEPROM
1376 write routine for first time initialisation.
1379 Support for Digital 2114x chips.
1380 Optional CONFIG_TULIP_SELECT_MEDIA for board specific
1381 modem chip initialisation (KS8761/QS6611).
1384 Support for National dp83815 chips.
1387 Support for National dp8382[01] gigabit chips.
1389 - NETWORK Support (other):
1391 CONFIG_DRIVER_AT91EMAC
1392 Support for AT91RM9200 EMAC.
1395 Define this to use reduced MII inteface
1397 CONFIG_DRIVER_AT91EMAC_QUIET
1398 If this defined, the driver is quiet.
1399 The driver doen't show link status messages.
1401 CONFIG_CALXEDA_XGMAC
1402 Support for the Calxeda XGMAC device
1405 Support for SMSC's LAN91C96 chips.
1407 CONFIG_LAN91C96_BASE
1408 Define this to hold the physical address
1409 of the LAN91C96's I/O space
1411 CONFIG_LAN91C96_USE_32_BIT
1412 Define this to enable 32 bit addressing
1415 Support for SMSC's LAN91C111 chip
1417 CONFIG_SMC91111_BASE
1418 Define this to hold the physical address
1419 of the device (I/O space)
1421 CONFIG_SMC_USE_32_BIT
1422 Define this if data bus is 32 bits
1424 CONFIG_SMC_USE_IOFUNCS
1425 Define this to use i/o functions instead of macros
1426 (some hardware wont work with macros)
1428 CONFIG_DRIVER_TI_EMAC
1429 Support for davinci emac
1431 CONFIG_SYS_DAVINCI_EMAC_PHY_COUNT
1432 Define this if you have more then 3 PHYs.
1435 Support for Faraday's FTGMAC100 Gigabit SoC Ethernet
1437 CONFIG_FTGMAC100_EGIGA
1438 Define this to use GE link update with gigabit PHY.
1439 Define this if FTGMAC100 is connected to gigabit PHY.
1440 If your system has 10/100 PHY only, it might not occur
1441 wrong behavior. Because PHY usually return timeout or
1442 useless data when polling gigabit status and gigabit
1443 control registers. This behavior won't affect the
1444 correctnessof 10/100 link speed update.
1447 Support for SMSC's LAN911x and LAN921x chips
1450 Define this to hold the physical address
1451 of the device (I/O space)
1453 CONFIG_SMC911X_32_BIT
1454 Define this if data bus is 32 bits
1456 CONFIG_SMC911X_16_BIT
1457 Define this if data bus is 16 bits. If your processor
1458 automatically converts one 32 bit word to two 16 bit
1459 words you may also try CONFIG_SMC911X_32_BIT.
1462 Support for Renesas on-chip Ethernet controller
1464 CONFIG_SH_ETHER_USE_PORT
1465 Define the number of ports to be used
1467 CONFIG_SH_ETHER_PHY_ADDR
1468 Define the ETH PHY's address
1470 CONFIG_SH_ETHER_CACHE_WRITEBACK
1471 If this option is set, the driver enables cache flush.
1475 Support for PWM modul on the imx6.
1479 Support TPM devices.
1482 Support for i2c bus TPM devices. Only one device
1483 per system is supported at this time.
1485 CONFIG_TPM_TIS_I2C_BUS_NUMBER
1486 Define the the i2c bus number for the TPM device
1488 CONFIG_TPM_TIS_I2C_SLAVE_ADDRESS
1489 Define the TPM's address on the i2c bus
1491 CONFIG_TPM_TIS_I2C_BURST_LIMITATION
1492 Define the burst count bytes upper limit
1494 CONFIG_TPM_ATMEL_TWI
1495 Support for Atmel TWI TPM device. Requires I2C support.
1498 Support for generic parallel port TPM devices. Only one device
1499 per system is supported at this time.
1501 CONFIG_TPM_TIS_BASE_ADDRESS
1502 Base address where the generic TPM device is mapped
1503 to. Contemporary x86 systems usually map it at
1507 Add tpm monitor functions.
1508 Requires CONFIG_TPM. If CONFIG_TPM_AUTH_SESSIONS is set, also
1509 provides monitor access to authorized functions.
1512 Define this to enable the TPM support library which provides
1513 functional interfaces to some TPM commands.
1514 Requires support for a TPM device.
1516 CONFIG_TPM_AUTH_SESSIONS
1517 Define this to enable authorized functions in the TPM library.
1518 Requires CONFIG_TPM and CONFIG_SHA1.
1521 At the moment only the UHCI host controller is
1522 supported (PIP405, MIP405, MPC5200); define
1523 CONFIG_USB_UHCI to enable it.
1524 define CONFIG_USB_KEYBOARD to enable the USB Keyboard
1525 and define CONFIG_USB_STORAGE to enable the USB
1528 Supported are USB Keyboards and USB Floppy drives
1530 MPC5200 USB requires additional defines:
1532 for 528 MHz Clock: 0x0001bbbb
1536 for differential drivers: 0x00001000
1537 for single ended drivers: 0x00005000
1538 for differential drivers on PSC3: 0x00000100
1539 for single ended drivers on PSC3: 0x00004100
1540 CONFIG_SYS_USB_EVENT_POLL
1541 May be defined to allow interrupt polling
1542 instead of using asynchronous interrupts
1544 CONFIG_USB_EHCI_TXFIFO_THRESH enables setting of the
1545 txfilltuning field in the EHCI controller on reset.
1547 CONFIG_USB_DWC2_REG_ADDR the physical CPU address of the DWC2
1548 HW module registers.
1551 Define the below if you wish to use the USB console.
1552 Once firmware is rebuilt from a serial console issue the
1553 command "setenv stdin usbtty; setenv stdout usbtty" and
1554 attach your USB cable. The Unix command "dmesg" should print
1555 it has found a new device. The environment variable usbtty
1556 can be set to gserial or cdc_acm to enable your device to
1557 appear to a USB host as a Linux gserial device or a
1558 Common Device Class Abstract Control Model serial device.
1559 If you select usbtty = gserial you should be able to enumerate
1561 # modprobe usbserial vendor=0xVendorID product=0xProductID
1562 else if using cdc_acm, simply setting the environment
1563 variable usbtty to be cdc_acm should suffice. The following
1564 might be defined in YourBoardName.h
1567 Define this to build a UDC device
1570 Define this to have a tty type of device available to
1571 talk to the UDC device
1574 Define this to enable the high speed support for usb
1575 device and usbtty. If this feature is enabled, a routine
1576 int is_usbd_high_speed(void)
1577 also needs to be defined by the driver to dynamically poll
1578 whether the enumeration has succeded at high speed or full
1581 CONFIG_SYS_CONSOLE_IS_IN_ENV
1582 Define this if you want stdin, stdout &/or stderr to
1586 CONFIG_SYS_USB_EXTC_CLK 0xBLAH
1587 Derive USB clock from external clock "blah"
1588 - CONFIG_SYS_USB_EXTC_CLK 0x02
1590 CONFIG_SYS_USB_BRG_CLK 0xBLAH
1591 Derive USB clock from brgclk
1592 - CONFIG_SYS_USB_BRG_CLK 0x04
1594 If you have a USB-IF assigned VendorID then you may wish to
1595 define your own vendor specific values either in BoardName.h
1596 or directly in usbd_vendor_info.h. If you don't define
1597 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME,
1598 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot
1599 should pretend to be a Linux device to it's target host.
1601 CONFIG_USBD_MANUFACTURER
1602 Define this string as the name of your company for
1603 - CONFIG_USBD_MANUFACTURER "my company"
1605 CONFIG_USBD_PRODUCT_NAME
1606 Define this string as the name of your product
1607 - CONFIG_USBD_PRODUCT_NAME "acme usb device"
1609 CONFIG_USBD_VENDORID
1610 Define this as your assigned Vendor ID from the USB
1611 Implementors Forum. This *must* be a genuine Vendor ID
1612 to avoid polluting the USB namespace.
1613 - CONFIG_USBD_VENDORID 0xFFFF
1615 CONFIG_USBD_PRODUCTID
1616 Define this as the unique Product ID
1618 - CONFIG_USBD_PRODUCTID 0xFFFF
1620 - ULPI Layer Support:
1621 The ULPI (UTMI Low Pin (count) Interface) PHYs are supported via
1622 the generic ULPI layer. The generic layer accesses the ULPI PHY
1623 via the platform viewport, so you need both the genric layer and
1624 the viewport enabled. Currently only Chipidea/ARC based
1625 viewport is supported.
1626 To enable the ULPI layer support, define CONFIG_USB_ULPI and
1627 CONFIG_USB_ULPI_VIEWPORT in your board configuration file.
1628 If your ULPI phy needs a different reference clock than the
1629 standard 24 MHz then you have to define CONFIG_ULPI_REF_CLK to
1630 the appropriate value in Hz.
1633 The MMC controller on the Intel PXA is supported. To
1634 enable this define CONFIG_MMC. The MMC can be
1635 accessed from the boot prompt by mapping the device
1636 to physical memory similar to flash. Command line is
1637 enabled with CONFIG_CMD_MMC. The MMC driver also works with
1638 the FAT fs. This is enabled with CONFIG_CMD_FAT.
1641 Support for Renesas on-chip MMCIF controller
1643 CONFIG_SH_MMCIF_ADDR
1644 Define the base address of MMCIF registers
1647 Define the clock frequency for MMCIF
1650 Enable the generic MMC driver
1652 CONFIG_SUPPORT_EMMC_BOOT
1653 Enable some additional features of the eMMC boot partitions.
1655 CONFIG_SUPPORT_EMMC_RPMB
1656 Enable the commands for reading, writing and programming the
1657 key for the Replay Protection Memory Block partition in eMMC.
1659 - USB Device Firmware Update (DFU) class support:
1661 This enables the USB portion of the DFU USB class
1664 This enables the command "dfu" which is used to have
1665 U-Boot create a DFU class device via USB. This command
1666 requires that the "dfu_alt_info" environment variable be
1667 set and define the alt settings to expose to the host.
1670 This enables support for exposing (e)MMC devices via DFU.
1673 This enables support for exposing NAND devices via DFU.
1676 This enables support for exposing RAM via DFU.
1677 Note: DFU spec refer to non-volatile memory usage, but
1678 allow usages beyond the scope of spec - here RAM usage,
1679 one that would help mostly the developer.
1681 CONFIG_SYS_DFU_DATA_BUF_SIZE
1682 Dfu transfer uses a buffer before writing data to the
1683 raw storage device. Make the size (in bytes) of this buffer
1684 configurable. The size of this buffer is also configurable
1685 through the "dfu_bufsiz" environment variable.
1687 CONFIG_SYS_DFU_MAX_FILE_SIZE
1688 When updating files rather than the raw storage device,
1689 we use a static buffer to copy the file into and then write
1690 the buffer once we've been given the whole file. Define
1691 this to the maximum filesize (in bytes) for the buffer.
1692 Default is 4 MiB if undefined.
1694 DFU_DEFAULT_POLL_TIMEOUT
1695 Poll timeout [ms], is the timeout a device can send to the
1696 host. The host must wait for this timeout before sending
1697 a subsequent DFU_GET_STATUS request to the device.
1699 DFU_MANIFEST_POLL_TIMEOUT
1700 Poll timeout [ms], which the device sends to the host when
1701 entering dfuMANIFEST state. Host waits this timeout, before
1702 sending again an USB request to the device.
1704 - USB Device Android Fastboot support:
1706 This enables the command "fastboot" which enables the Android
1707 fastboot mode for the platform's USB device. Fastboot is a USB
1708 protocol for downloading images, flashing and device control
1709 used on Android devices.
1710 See doc/README.android-fastboot for more information.
1712 CONFIG_ANDROID_BOOT_IMAGE
1713 This enables support for booting images which use the Android
1714 image format header.
1716 CONFIG_USB_FASTBOOT_BUF_ADDR
1717 The fastboot protocol requires a large memory buffer for
1718 downloads. Define this to the starting RAM address to use for
1721 CONFIG_USB_FASTBOOT_BUF_SIZE
1722 The fastboot protocol requires a large memory buffer for
1723 downloads. This buffer should be as large as possible for a
1724 platform. Define this to the size available RAM for fastboot.
1726 CONFIG_FASTBOOT_FLASH
1727 The fastboot protocol includes a "flash" command for writing
1728 the downloaded image to a non-volatile storage device. Define
1729 this to enable the "fastboot flash" command.
1731 CONFIG_FASTBOOT_FLASH_MMC_DEV
1732 The fastboot "flash" command requires additional information
1733 regarding the non-volatile storage device. Define this to
1734 the eMMC device that fastboot should use to store the image.
1736 CONFIG_FASTBOOT_GPT_NAME
1737 The fastboot "flash" command supports writing the downloaded
1738 image to the Protective MBR and the Primary GUID Partition
1739 Table. (Additionally, this downloaded image is post-processed
1740 to generate and write the Backup GUID Partition Table.)
1741 This occurs when the specified "partition name" on the
1742 "fastboot flash" command line matches this value.
1743 Default is GPT_ENTRY_NAME (currently "gpt") if undefined.
1745 - Journaling Flash filesystem support:
1746 CONFIG_JFFS2_NAND, CONFIG_JFFS2_NAND_OFF, CONFIG_JFFS2_NAND_SIZE,
1747 CONFIG_JFFS2_NAND_DEV
1748 Define these for a default partition on a NAND device
1750 CONFIG_SYS_JFFS2_FIRST_SECTOR,
1751 CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS
1752 Define these for a default partition on a NOR device
1754 CONFIG_SYS_JFFS_CUSTOM_PART
1755 Define this to create an own partition. You have to provide a
1756 function struct part_info* jffs2_part_info(int part_num)
1758 If you define only one JFFS2 partition you may also want to
1759 #define CONFIG_SYS_JFFS_SINGLE_PART 1
1760 to disable the command chpart. This is the default when you
1761 have not defined a custom partition
1763 - FAT(File Allocation Table) filesystem write function support:
1766 Define this to enable support for saving memory data as a
1767 file in FAT formatted partition.
1769 This will also enable the command "fatwrite" enabling the
1770 user to write files to FAT.
1772 CBFS (Coreboot Filesystem) support
1775 Define this to enable support for reading from a Coreboot
1776 filesystem. Available commands are cbfsinit, cbfsinfo, cbfsls
1779 - FAT(File Allocation Table) filesystem cluster size:
1780 CONFIG_FS_FAT_MAX_CLUSTSIZE
1782 Define the max cluster size for fat operations else
1783 a default value of 65536 will be defined.
1788 Define this to enable standard (PC-Style) keyboard
1792 Standard PC keyboard driver with US (is default) and
1793 GERMAN key layout (switch via environment 'keymap=de') support.
1794 Export function i8042_kbd_init, i8042_tstc and i8042_getc
1795 for cfb_console. Supports cursor blinking.
1798 Enables a Chrome OS keyboard using the CROS_EC interface.
1799 This uses CROS_EC to communicate with a second microcontroller
1800 which provides key scans on request.
1805 Define this to enable video support (for output to
1808 CONFIG_VIDEO_CT69000
1810 Enable Chips & Technologies 69000 Video chip
1812 CONFIG_VIDEO_SMI_LYNXEM
1813 Enable Silicon Motion SMI 712/710/810 Video chip. The
1814 video output is selected via environment 'videoout'
1815 (1 = LCD and 2 = CRT). If videoout is undefined, CRT is
1818 For the CT69000 and SMI_LYNXEM drivers, videomode is
1819 selected via environment 'videomode'. Two different ways
1821 - "videomode=num" 'num' is a standard LiLo mode numbers.
1822 Following standard modes are supported (* is default):
1824 Colors 640x480 800x600 1024x768 1152x864 1280x1024
1825 -------------+---------------------------------------------
1826 8 bits | 0x301* 0x303 0x305 0x161 0x307
1827 15 bits | 0x310 0x313 0x316 0x162 0x319
1828 16 bits | 0x311 0x314 0x317 0x163 0x31A
1829 24 bits | 0x312 0x315 0x318 ? 0x31B
1830 -------------+---------------------------------------------
1831 (i.e. setenv videomode 317; saveenv; reset;)
1833 - "videomode=bootargs" all the video parameters are parsed
1834 from the bootargs. (See drivers/video/videomodes.c)
1837 CONFIG_VIDEO_SED13806
1838 Enable Epson SED13806 driver. This driver supports 8bpp
1839 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP
1840 or CONFIG_VIDEO_SED13806_16BPP
1843 Enable the Freescale DIU video driver. Reference boards for
1844 SOCs that have a DIU should define this macro to enable DIU
1845 support, and should also define these other macros:
1851 CONFIG_VIDEO_SW_CURSOR
1852 CONFIG_VGA_AS_SINGLE_DEVICE
1854 CONFIG_VIDEO_BMP_LOGO
1856 The DIU driver will look for the 'video-mode' environment
1857 variable, and if defined, enable the DIU as a console during
1858 boot. See the documentation file README.video for a
1859 description of this variable.
1863 Enable the VGA video / BIOS for x86. The alternative if you
1864 are using coreboot is to use the coreboot frame buffer
1871 Define this to enable a custom keyboard support.
1872 This simply calls drv_keyboard_init() which must be
1873 defined in your board-specific files.
1874 The only board using this so far is RBC823.
1876 - LCD Support: CONFIG_LCD
1878 Define this to enable LCD support (for output to LCD
1879 display); also select one of the supported displays
1880 by defining one of these:
1884 HITACHI TX09D70VM1CCA, 3.5", 240x320.
1886 CONFIG_NEC_NL6448AC33:
1888 NEC NL6448AC33-18. Active, color, single scan.
1890 CONFIG_NEC_NL6448BC20
1892 NEC NL6448BC20-08. 6.5", 640x480.
1893 Active, color, single scan.
1895 CONFIG_NEC_NL6448BC33_54
1897 NEC NL6448BC33-54. 10.4", 640x480.
1898 Active, color, single scan.
1902 Sharp 320x240. Active, color, single scan.
1903 It isn't 16x9, and I am not sure what it is.
1905 CONFIG_SHARP_LQ64D341
1907 Sharp LQ64D341 display, 640x480.
1908 Active, color, single scan.
1912 HLD1045 display, 640x480.
1913 Active, color, single scan.
1917 Optrex CBL50840-2 NF-FW 99 22 M5
1919 Hitachi LMG6912RPFC-00T
1923 320x240. Black & white.
1925 Normally display is black on white background; define
1926 CONFIG_SYS_WHITE_ON_BLACK to get it inverted.
1928 CONFIG_LCD_ALIGNMENT
1930 Normally the LCD is page-aligned (typically 4KB). If this is
1931 defined then the LCD will be aligned to this value instead.
1932 For ARM it is sometimes useful to use MMU_SECTION_SIZE
1933 here, since it is cheaper to change data cache settings on
1934 a per-section basis.
1936 CONFIG_CONSOLE_SCROLL_LINES
1938 When the console need to be scrolled, this is the number of
1939 lines to scroll by. It defaults to 1. Increasing this makes
1940 the console jump but can help speed up operation when scrolling
1945 Support drawing of RLE8-compressed bitmaps on the LCD.
1949 Enables an 'i2c edid' command which can read EDID
1950 information over I2C from an attached LCD display.
1952 - Splash Screen Support: CONFIG_SPLASH_SCREEN
1954 If this option is set, the environment is checked for
1955 a variable "splashimage". If found, the usual display
1956 of logo, copyright and system information on the LCD
1957 is suppressed and the BMP image at the address
1958 specified in "splashimage" is loaded instead. The
1959 console is redirected to the "nulldev", too. This
1960 allows for a "silent" boot where a splash screen is
1961 loaded very quickly after power-on.
1963 CONFIG_SPLASHIMAGE_GUARD
1965 If this option is set, then U-Boot will prevent the environment
1966 variable "splashimage" from being set to a problematic address
1967 (see README.displaying-bmps).
1968 This option is useful for targets where, due to alignment
1969 restrictions, an improperly aligned BMP image will cause a data
1970 abort. If you think you will not have problems with unaligned
1971 accesses (for example because your toolchain prevents them)
1972 there is no need to set this option.
1974 CONFIG_SPLASH_SCREEN_ALIGN
1976 If this option is set the splash image can be freely positioned
1977 on the screen. Environment variable "splashpos" specifies the
1978 position as "x,y". If a positive number is given it is used as
1979 number of pixel from left/top. If a negative number is given it
1980 is used as number of pixel from right/bottom. You can also
1981 specify 'm' for centering the image.
1984 setenv splashpos m,m
1985 => image at center of screen
1987 setenv splashpos 30,20
1988 => image at x = 30 and y = 20
1990 setenv splashpos -10,m
1991 => vertically centered image
1992 at x = dspWidth - bmpWidth - 9
1994 - Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP
1996 If this option is set, additionally to standard BMP
1997 images, gzipped BMP images can be displayed via the
1998 splashscreen support or the bmp command.
2000 - Run length encoded BMP image (RLE8) support: CONFIG_VIDEO_BMP_RLE8
2002 If this option is set, 8-bit RLE compressed BMP images
2003 can be displayed via the splashscreen support or the
2006 - Do compressing for memory range:
2009 If this option is set, it would use zlib deflate method
2010 to compress the specified memory at its best effort.
2012 - Compression support:
2015 Enabled by default to support gzip compressed images.
2019 If this option is set, support for bzip2 compressed
2020 images is included. If not, only uncompressed and gzip
2021 compressed images are supported.
2023 NOTE: the bzip2 algorithm requires a lot of RAM, so
2024 the malloc area (as defined by CONFIG_SYS_MALLOC_LEN) should
2029 If this option is set, support for lzma compressed
2032 Note: The LZMA algorithm adds between 2 and 4KB of code and it
2033 requires an amount of dynamic memory that is given by the
2036 (1846 + 768 << (lc + lp)) * sizeof(uint16)
2038 Where lc and lp stand for, respectively, Literal context bits
2039 and Literal pos bits.
2041 This value is upper-bounded by 14MB in the worst case. Anyway,
2042 for a ~4MB large kernel image, we have lc=3 and lp=0 for a
2043 total amount of (1846 + 768 << (3 + 0)) * 2 = ~41KB... that is
2044 a very small buffer.
2046 Use the lzmainfo tool to determinate the lc and lp values and
2047 then calculate the amount of needed dynamic memory (ensuring
2048 the appropriate CONFIG_SYS_MALLOC_LEN value).
2052 If this option is set, support for LZO compressed images
2058 The address of PHY on MII bus.
2060 CONFIG_PHY_CLOCK_FREQ (ppc4xx)
2062 The clock frequency of the MII bus
2066 If this option is set, support for speed/duplex
2067 detection of gigabit PHY is included.
2069 CONFIG_PHY_RESET_DELAY
2071 Some PHY like Intel LXT971A need extra delay after
2072 reset before any MII register access is possible.
2073 For such PHY, set this option to the usec delay
2074 required. (minimum 300usec for LXT971A)
2076 CONFIG_PHY_CMD_DELAY (ppc4xx)
2078 Some PHY like Intel LXT971A need extra delay after
2079 command issued before MII status register can be read
2089 Define a default value for Ethernet address to use
2090 for the respective Ethernet interface, in case this
2091 is not determined automatically.
2096 Define a default value for the IP address to use for
2097 the default Ethernet interface, in case this is not
2098 determined through e.g. bootp.
2099 (Environment variable "ipaddr")
2101 - Server IP address:
2104 Defines a default value for the IP address of a TFTP
2105 server to contact when using the "tftboot" command.
2106 (Environment variable "serverip")
2108 CONFIG_KEEP_SERVERADDR
2110 Keeps the server's MAC address, in the env 'serveraddr'
2111 for passing to bootargs (like Linux's netconsole option)
2113 - Gateway IP address:
2116 Defines a default value for the IP address of the
2117 default router where packets to other networks are
2119 (Environment variable "gatewayip")
2124 Defines a default value for the subnet mask (or
2125 routing prefix) which is used to determine if an IP
2126 address belongs to the local subnet or needs to be
2127 forwarded through a router.
2128 (Environment variable "netmask")
2130 - Multicast TFTP Mode:
2133 Defines whether you want to support multicast TFTP as per
2134 rfc-2090; for example to work with atftp. Lets lots of targets
2135 tftp down the same boot image concurrently. Note: the Ethernet
2136 driver in use must provide a function: mcast() to join/leave a
2139 - BOOTP Recovery Mode:
2140 CONFIG_BOOTP_RANDOM_DELAY
2142 If you have many targets in a network that try to
2143 boot using BOOTP, you may want to avoid that all
2144 systems send out BOOTP requests at precisely the same
2145 moment (which would happen for instance at recovery
2146 from a power failure, when all systems will try to
2147 boot, thus flooding the BOOTP server. Defining
2148 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
2149 inserted before sending out BOOTP requests. The
2150 following delays are inserted then:
2152 1st BOOTP request: delay 0 ... 1 sec
2153 2nd BOOTP request: delay 0 ... 2 sec
2154 3rd BOOTP request: delay 0 ... 4 sec
2156 BOOTP requests: delay 0 ... 8 sec
2158 CONFIG_BOOTP_ID_CACHE_SIZE
2160 BOOTP packets are uniquely identified using a 32-bit ID. The
2161 server will copy the ID from client requests to responses and
2162 U-Boot will use this to determine if it is the destination of
2163 an incoming response. Some servers will check that addresses
2164 aren't in use before handing them out (usually using an ARP
2165 ping) and therefore take up to a few hundred milliseconds to
2166 respond. Network congestion may also influence the time it
2167 takes for a response to make it back to the client. If that
2168 time is too long, U-Boot will retransmit requests. In order
2169 to allow earlier responses to still be accepted after these
2170 retransmissions, U-Boot's BOOTP client keeps a small cache of
2171 IDs. The CONFIG_BOOTP_ID_CACHE_SIZE controls the size of this
2172 cache. The default is to keep IDs for up to four outstanding
2173 requests. Increasing this will allow U-Boot to accept offers
2174 from a BOOTP client in networks with unusually high latency.
2176 - BOOTP Random transaction ID:
2177 CONFIG_BOOTP_RANDOM_ID
2179 The standard algorithm to generate a DHCP/BOOTP transaction ID
2180 by using the MAC address and the current time stamp may not
2181 quite unlikely produce duplicate transaction IDs from different
2182 clients in the same network. This option creates a transaction
2183 ID using the rand() function. Provided that the RNG has been
2184 seeded well, this should guarantee unique transaction IDs
2187 - DHCP Advanced Options:
2188 You can fine tune the DHCP functionality by defining
2189 CONFIG_BOOTP_* symbols:
2191 CONFIG_BOOTP_SUBNETMASK
2192 CONFIG_BOOTP_GATEWAY
2193 CONFIG_BOOTP_HOSTNAME
2194 CONFIG_BOOTP_NISDOMAIN
2195 CONFIG_BOOTP_BOOTPATH
2196 CONFIG_BOOTP_BOOTFILESIZE
2199 CONFIG_BOOTP_SEND_HOSTNAME
2200 CONFIG_BOOTP_NTPSERVER
2201 CONFIG_BOOTP_TIMEOFFSET
2202 CONFIG_BOOTP_VENDOREX
2203 CONFIG_BOOTP_MAY_FAIL
2205 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip
2206 environment variable, not the BOOTP server.
2208 CONFIG_BOOTP_MAY_FAIL - If the DHCP server is not found
2209 after the configured retry count, the call will fail
2210 instead of starting over. This can be used to fail over
2211 to Link-local IP address configuration if the DHCP server
2214 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS
2215 serverip from a DHCP server, it is possible that more
2216 than one DNS serverip is offered to the client.
2217 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS
2218 serverip will be stored in the additional environment
2219 variable "dnsip2". The first DNS serverip is always
2220 stored in the variable "dnsip", when CONFIG_BOOTP_DNS
2223 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable
2224 to do a dynamic update of a DNS server. To do this, they
2225 need the hostname of the DHCP requester.
2226 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content
2227 of the "hostname" environment variable is passed as
2228 option 12 to the DHCP server.
2230 CONFIG_BOOTP_DHCP_REQUEST_DELAY
2232 A 32bit value in microseconds for a delay between
2233 receiving a "DHCP Offer" and sending the "DHCP Request".
2234 This fixes a problem with certain DHCP servers that don't
2235 respond 100% of the time to a "DHCP request". E.g. On an
2236 AT91RM9200 processor running at 180MHz, this delay needed
2237 to be *at least* 15,000 usec before a Windows Server 2003
2238 DHCP server would reply 100% of the time. I recommend at
2239 least 50,000 usec to be safe. The alternative is to hope
2240 that one of the retries will be successful but note that
2241 the DHCP timeout and retry process takes a longer than
2244 - Link-local IP address negotiation:
2245 Negotiate with other link-local clients on the local network
2246 for an address that doesn't require explicit configuration.
2247 This is especially useful if a DHCP server cannot be guaranteed
2248 to exist in all environments that the device must operate.
2250 See doc/README.link-local for more information.
2253 CONFIG_CDP_DEVICE_ID
2255 The device id used in CDP trigger frames.
2257 CONFIG_CDP_DEVICE_ID_PREFIX
2259 A two character string which is prefixed to the MAC address
2264 A printf format string which contains the ascii name of
2265 the port. Normally is set to "eth%d" which sets
2266 eth0 for the first Ethernet, eth1 for the second etc.
2268 CONFIG_CDP_CAPABILITIES
2270 A 32bit integer which indicates the device capabilities;
2271 0x00000010 for a normal host which does not forwards.
2275 An ascii string containing the version of the software.
2279 An ascii string containing the name of the platform.
2283 A 32bit integer sent on the trigger.
2285 CONFIG_CDP_POWER_CONSUMPTION
2287 A 16bit integer containing the power consumption of the
2288 device in .1 of milliwatts.
2290 CONFIG_CDP_APPLIANCE_VLAN_TYPE
2292 A byte containing the id of the VLAN.
2294 - Status LED: CONFIG_STATUS_LED
2296 Several configurations allow to display the current
2297 status using a LED. For instance, the LED will blink
2298 fast while running U-Boot code, stop blinking as
2299 soon as a reply to a BOOTP request was received, and
2300 start blinking slow once the Linux kernel is running
2301 (supported by a status LED driver in the Linux
2302 kernel). Defining CONFIG_STATUS_LED enables this
2308 The status LED can be connected to a GPIO pin.
2309 In such cases, the gpio_led driver can be used as a
2310 status LED backend implementation. Define CONFIG_GPIO_LED
2311 to include the gpio_led driver in the U-Boot binary.
2313 CONFIG_GPIO_LED_INVERTED_TABLE
2314 Some GPIO connected LEDs may have inverted polarity in which
2315 case the GPIO high value corresponds to LED off state and
2316 GPIO low value corresponds to LED on state.
2317 In such cases CONFIG_GPIO_LED_INVERTED_TABLE may be defined
2318 with a list of GPIO LEDs that have inverted polarity.
2320 - CAN Support: CONFIG_CAN_DRIVER
2322 Defining CONFIG_CAN_DRIVER enables CAN driver support
2323 on those systems that support this (optional)
2324 feature, like the TQM8xxL modules.
2326 - I2C Support: CONFIG_SYS_I2C
2328 This enable the NEW i2c subsystem, and will allow you to use
2329 i2c commands at the u-boot command line (as long as you set
2330 CONFIG_CMD_I2C in CONFIG_COMMANDS) and communicate with i2c
2331 based realtime clock chips or other i2c devices. See
2332 common/cmd_i2c.c for a description of the command line
2335 ported i2c driver to the new framework:
2336 - drivers/i2c/soft_i2c.c:
2337 - activate first bus with CONFIG_SYS_I2C_SOFT define
2338 CONFIG_SYS_I2C_SOFT_SPEED and CONFIG_SYS_I2C_SOFT_SLAVE
2339 for defining speed and slave address
2340 - activate second bus with I2C_SOFT_DECLARATIONS2 define
2341 CONFIG_SYS_I2C_SOFT_SPEED_2 and CONFIG_SYS_I2C_SOFT_SLAVE_2
2342 for defining speed and slave address
2343 - activate third bus with I2C_SOFT_DECLARATIONS3 define
2344 CONFIG_SYS_I2C_SOFT_SPEED_3 and CONFIG_SYS_I2C_SOFT_SLAVE_3
2345 for defining speed and slave address
2346 - activate fourth bus with I2C_SOFT_DECLARATIONS4 define
2347 CONFIG_SYS_I2C_SOFT_SPEED_4 and CONFIG_SYS_I2C_SOFT_SLAVE_4
2348 for defining speed and slave address
2350 - drivers/i2c/fsl_i2c.c:
2351 - activate i2c driver with CONFIG_SYS_I2C_FSL
2352 define CONFIG_SYS_FSL_I2C_OFFSET for setting the register
2353 offset CONFIG_SYS_FSL_I2C_SPEED for the i2c speed and
2354 CONFIG_SYS_FSL_I2C_SLAVE for the slave addr of the first
2356 - If your board supports a second fsl i2c bus, define
2357 CONFIG_SYS_FSL_I2C2_OFFSET for the register offset
2358 CONFIG_SYS_FSL_I2C2_SPEED for the speed and
2359 CONFIG_SYS_FSL_I2C2_SLAVE for the slave address of the
2362 - drivers/i2c/tegra_i2c.c:
2363 - activate this driver with CONFIG_SYS_I2C_TEGRA
2364 - This driver adds 4 i2c buses with a fix speed from
2365 100000 and the slave addr 0!
2367 - drivers/i2c/ppc4xx_i2c.c
2368 - activate this driver with CONFIG_SYS_I2C_PPC4XX
2369 - CONFIG_SYS_I2C_PPC4XX_CH0 activate hardware channel 0
2370 - CONFIG_SYS_I2C_PPC4XX_CH1 activate hardware channel 1
2372 - drivers/i2c/i2c_mxc.c
2373 - activate this driver with CONFIG_SYS_I2C_MXC
2374 - define speed for bus 1 with CONFIG_SYS_MXC_I2C1_SPEED
2375 - define slave for bus 1 with CONFIG_SYS_MXC_I2C1_SLAVE
2376 - define speed for bus 2 with CONFIG_SYS_MXC_I2C2_SPEED
2377 - define slave for bus 2 with CONFIG_SYS_MXC_I2C2_SLAVE
2378 - define speed for bus 3 with CONFIG_SYS_MXC_I2C3_SPEED
2379 - define slave for bus 3 with CONFIG_SYS_MXC_I2C3_SLAVE
2380 If those defines are not set, default value is 100000
2381 for speed, and 0 for slave.
2383 - drivers/i2c/rcar_i2c.c:
2384 - activate this driver with CONFIG_SYS_I2C_RCAR
2385 - This driver adds 4 i2c buses
2387 - CONFIG_SYS_RCAR_I2C0_BASE for setting the register channel 0
2388 - CONFIG_SYS_RCAR_I2C0_SPEED for for the speed channel 0
2389 - CONFIG_SYS_RCAR_I2C1_BASE for setting the register channel 1
2390 - CONFIG_SYS_RCAR_I2C1_SPEED for for the speed channel 1
2391 - CONFIG_SYS_RCAR_I2C2_BASE for setting the register channel 2
2392 - CONFIG_SYS_RCAR_I2C2_SPEED for for the speed channel 2
2393 - CONFIG_SYS_RCAR_I2C3_BASE for setting the register channel 3
2394 - CONFIG_SYS_RCAR_I2C3_SPEED for for the speed channel 3
2395 - CONFIF_SYS_RCAR_I2C_NUM_CONTROLLERS for number of i2c buses
2397 - drivers/i2c/sh_i2c.c:
2398 - activate this driver with CONFIG_SYS_I2C_SH
2399 - This driver adds from 2 to 5 i2c buses
2401 - CONFIG_SYS_I2C_SH_BASE0 for setting the register channel 0
2402 - CONFIG_SYS_I2C_SH_SPEED0 for for the speed channel 0
2403 - CONFIG_SYS_I2C_SH_BASE1 for setting the register channel 1
2404 - CONFIG_SYS_I2C_SH_SPEED1 for for the speed channel 1
2405 - CONFIG_SYS_I2C_SH_BASE2 for setting the register channel 2
2406 - CONFIG_SYS_I2C_SH_SPEED2 for for the speed channel 2
2407 - CONFIG_SYS_I2C_SH_BASE3 for setting the register channel 3
2408 - CONFIG_SYS_I2C_SH_SPEED3 for for the speed channel 3
2409 - CONFIG_SYS_I2C_SH_BASE4 for setting the register channel 4
2410 - CONFIG_SYS_I2C_SH_SPEED4 for for the speed channel 4
2411 - CONFIG_SYS_I2C_SH_BASE5 for setting the register channel 5
2412 - CONFIG_SYS_I2C_SH_SPEED5 for for the speed channel 5
2413 - CONFIG_SYS_I2C_SH_NUM_CONTROLLERS for number of i2c buses
2415 - drivers/i2c/omap24xx_i2c.c
2416 - activate this driver with CONFIG_SYS_I2C_OMAP24XX
2417 - CONFIG_SYS_OMAP24_I2C_SPEED speed channel 0
2418 - CONFIG_SYS_OMAP24_I2C_SLAVE slave addr channel 0
2419 - CONFIG_SYS_OMAP24_I2C_SPEED1 speed channel 1
2420 - CONFIG_SYS_OMAP24_I2C_SLAVE1 slave addr channel 1
2421 - CONFIG_SYS_OMAP24_I2C_SPEED2 speed channel 2
2422 - CONFIG_SYS_OMAP24_I2C_SLAVE2 slave addr channel 2
2423 - CONFIG_SYS_OMAP24_I2C_SPEED3 speed channel 3
2424 - CONFIG_SYS_OMAP24_I2C_SLAVE3 slave addr channel 3
2425 - CONFIG_SYS_OMAP24_I2C_SPEED4 speed channel 4
2426 - CONFIG_SYS_OMAP24_I2C_SLAVE4 slave addr channel 4
2428 - drivers/i2c/zynq_i2c.c
2429 - activate this driver with CONFIG_SYS_I2C_ZYNQ
2430 - set CONFIG_SYS_I2C_ZYNQ_SPEED for speed setting
2431 - set CONFIG_SYS_I2C_ZYNQ_SLAVE for slave addr
2433 - drivers/i2c/s3c24x0_i2c.c:
2434 - activate this driver with CONFIG_SYS_I2C_S3C24X0
2435 - This driver adds i2c buses (11 for Exynos5250, Exynos5420
2436 9 i2c buses for Exynos4 and 1 for S3C24X0 SoCs from Samsung)
2437 with a fix speed from 100000 and the slave addr 0!
2439 - drivers/i2c/ihs_i2c.c
2440 - activate this driver with CONFIG_SYS_I2C_IHS
2441 - CONFIG_SYS_I2C_IHS_CH0 activate hardware channel 0
2442 - CONFIG_SYS_I2C_IHS_SPEED_0 speed channel 0
2443 - CONFIG_SYS_I2C_IHS_SLAVE_0 slave addr channel 0
2444 - CONFIG_SYS_I2C_IHS_CH1 activate hardware channel 1
2445 - CONFIG_SYS_I2C_IHS_SPEED_1 speed channel 1
2446 - CONFIG_SYS_I2C_IHS_SLAVE_1 slave addr channel 1
2447 - CONFIG_SYS_I2C_IHS_CH2 activate hardware channel 2
2448 - CONFIG_SYS_I2C_IHS_SPEED_2 speed channel 2
2449 - CONFIG_SYS_I2C_IHS_SLAVE_2 slave addr channel 2
2450 - CONFIG_SYS_I2C_IHS_CH3 activate hardware channel 3
2451 - CONFIG_SYS_I2C_IHS_SPEED_3 speed channel 3
2452 - CONFIG_SYS_I2C_IHS_SLAVE_3 slave addr channel 3
2456 CONFIG_SYS_NUM_I2C_BUSES
2457 Hold the number of i2c buses you want to use. If you
2458 don't use/have i2c muxes on your i2c bus, this
2459 is equal to CONFIG_SYS_NUM_I2C_ADAPTERS, and you can
2462 CONFIG_SYS_I2C_DIRECT_BUS
2463 define this, if you don't use i2c muxes on your hardware.
2464 if CONFIG_SYS_I2C_MAX_HOPS is not defined or == 0 you can
2467 CONFIG_SYS_I2C_MAX_HOPS
2468 define how many muxes are maximal consecutively connected
2469 on one i2c bus. If you not use i2c muxes, omit this
2472 CONFIG_SYS_I2C_BUSES
2473 hold a list of buses you want to use, only used if
2474 CONFIG_SYS_I2C_DIRECT_BUS is not defined, for example
2475 a board with CONFIG_SYS_I2C_MAX_HOPS = 1 and
2476 CONFIG_SYS_NUM_I2C_BUSES = 9:
2478 CONFIG_SYS_I2C_BUSES {{0, {I2C_NULL_HOP}}, \
2479 {0, {{I2C_MUX_PCA9547, 0x70, 1}}}, \
2480 {0, {{I2C_MUX_PCA9547, 0x70, 2}}}, \
2481 {0, {{I2C_MUX_PCA9547, 0x70, 3}}}, \
2482 {0, {{I2C_MUX_PCA9547, 0x70, 4}}}, \
2483 {0, {{I2C_MUX_PCA9547, 0x70, 5}}}, \
2484 {1, {I2C_NULL_HOP}}, \
2485 {1, {{I2C_MUX_PCA9544, 0x72, 1}}}, \
2486 {1, {{I2C_MUX_PCA9544, 0x72, 2}}}, \
2490 bus 0 on adapter 0 without a mux
2491 bus 1 on adapter 0 with a PCA9547 on address 0x70 port 1
2492 bus 2 on adapter 0 with a PCA9547 on address 0x70 port 2
2493 bus 3 on adapter 0 with a PCA9547 on address 0x70 port 3
2494 bus 4 on adapter 0 with a PCA9547 on address 0x70 port 4
2495 bus 5 on adapter 0 with a PCA9547 on address 0x70 port 5
2496 bus 6 on adapter 1 without a mux
2497 bus 7 on adapter 1 with a PCA9544 on address 0x72 port 1
2498 bus 8 on adapter 1 with a PCA9544 on address 0x72 port 2
2500 If you do not have i2c muxes on your board, omit this define.
2502 - Legacy I2C Support: CONFIG_HARD_I2C
2504 NOTE: It is intended to move drivers to CONFIG_SYS_I2C which
2505 provides the following compelling advantages:
2507 - more than one i2c adapter is usable
2508 - approved multibus support
2509 - better i2c mux support
2511 ** Please consider updating your I2C driver now. **
2513 These enable legacy I2C serial bus commands. Defining
2514 CONFIG_HARD_I2C will include the appropriate I2C driver
2515 for the selected CPU.
2517 This will allow you to use i2c commands at the u-boot
2518 command line (as long as you set CONFIG_CMD_I2C in
2519 CONFIG_COMMANDS) and communicate with i2c based realtime
2520 clock chips. See common/cmd_i2c.c for a description of the
2521 command line interface.
2523 CONFIG_HARD_I2C selects a hardware I2C controller.
2525 There are several other quantities that must also be
2526 defined when you define CONFIG_HARD_I2C.
2528 In both cases you will need to define CONFIG_SYS_I2C_SPEED
2529 to be the frequency (in Hz) at which you wish your i2c bus
2530 to run and CONFIG_SYS_I2C_SLAVE to be the address of this node (ie
2531 the CPU's i2c node address).
2533 Now, the u-boot i2c code for the mpc8xx
2534 (arch/powerpc/cpu/mpc8xx/i2c.c) sets the CPU up as a master node
2535 and so its address should therefore be cleared to 0 (See,
2536 eg, MPC823e User's Manual p.16-473). So, set
2537 CONFIG_SYS_I2C_SLAVE to 0.
2539 CONFIG_SYS_I2C_INIT_MPC5XXX
2541 When a board is reset during an i2c bus transfer
2542 chips might think that the current transfer is still
2543 in progress. Reset the slave devices by sending start
2544 commands until the slave device responds.
2546 That's all that's required for CONFIG_HARD_I2C.
2548 If you use the software i2c interface (CONFIG_SYS_I2C_SOFT)
2549 then the following macros need to be defined (examples are
2550 from include/configs/lwmon.h):
2554 (Optional). Any commands necessary to enable the I2C
2555 controller or configure ports.
2557 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
2561 (Only for MPC8260 CPU). The I/O port to use (the code
2562 assumes both bits are on the same port). Valid values
2563 are 0..3 for ports A..D.
2567 The code necessary to make the I2C data line active
2568 (driven). If the data line is open collector, this
2571 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
2575 The code necessary to make the I2C data line tri-stated
2576 (inactive). If the data line is open collector, this
2579 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
2583 Code that returns true if the I2C data line is high,
2586 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
2590 If <bit> is true, sets the I2C data line high. If it
2591 is false, it clears it (low).
2593 eg: #define I2C_SDA(bit) \
2594 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
2595 else immr->im_cpm.cp_pbdat &= ~PB_SDA
2599 If <bit> is true, sets the I2C clock line high. If it
2600 is false, it clears it (low).
2602 eg: #define I2C_SCL(bit) \
2603 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
2604 else immr->im_cpm.cp_pbdat &= ~PB_SCL
2608 This delay is invoked four times per clock cycle so this
2609 controls the rate of data transfer. The data rate thus
2610 is 1 / (I2C_DELAY * 4). Often defined to be something
2613 #define I2C_DELAY udelay(2)
2615 CONFIG_SOFT_I2C_GPIO_SCL / CONFIG_SOFT_I2C_GPIO_SDA
2617 If your arch supports the generic GPIO framework (asm/gpio.h),
2618 then you may alternatively define the two GPIOs that are to be
2619 used as SCL / SDA. Any of the previous I2C_xxx macros will
2620 have GPIO-based defaults assigned to them as appropriate.
2622 You should define these to the GPIO value as given directly to
2623 the generic GPIO functions.
2625 CONFIG_SYS_I2C_INIT_BOARD
2627 When a board is reset during an i2c bus transfer
2628 chips might think that the current transfer is still
2629 in progress. On some boards it is possible to access
2630 the i2c SCLK line directly, either by using the
2631 processor pin as a GPIO or by having a second pin
2632 connected to the bus. If this option is defined a
2633 custom i2c_init_board() routine in boards/xxx/board.c
2634 is run early in the boot sequence.
2636 CONFIG_SYS_I2C_BOARD_LATE_INIT
2638 An alternative to CONFIG_SYS_I2C_INIT_BOARD. If this option is
2639 defined a custom i2c_board_late_init() routine in
2640 boards/xxx/board.c is run AFTER the operations in i2c_init()
2641 is completed. This callpoint can be used to unreset i2c bus
2642 using CPU i2c controller register accesses for CPUs whose i2c
2643 controller provide such a method. It is called at the end of
2644 i2c_init() to allow i2c_init operations to setup the i2c bus
2645 controller on the CPU (e.g. setting bus speed & slave address).
2647 CONFIG_I2CFAST (PPC405GP|PPC405EP only)
2649 This option enables configuration of bi_iic_fast[] flags
2650 in u-boot bd_info structure based on u-boot environment
2651 variable "i2cfast". (see also i2cfast)
2653 CONFIG_I2C_MULTI_BUS
2655 This option allows the use of multiple I2C buses, each of which
2656 must have a controller. At any point in time, only one bus is
2657 active. To switch to a different bus, use the 'i2c dev' command.
2658 Note that bus numbering is zero-based.
2660 CONFIG_SYS_I2C_NOPROBES
2662 This option specifies a list of I2C devices that will be skipped
2663 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS
2664 is set, specify a list of bus-device pairs. Otherwise, specify
2665 a 1D array of device addresses
2668 #undef CONFIG_I2C_MULTI_BUS
2669 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68}
2671 will skip addresses 0x50 and 0x68 on a board with one I2C bus
2673 #define CONFIG_I2C_MULTI_BUS
2674 #define CONFIG_SYS_I2C_MULTI_NOPROBES {{0,0x50},{0,0x68},{1,0x54}}
2676 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1
2678 CONFIG_SYS_SPD_BUS_NUM
2680 If defined, then this indicates the I2C bus number for DDR SPD.
2681 If not defined, then U-Boot assumes that SPD is on I2C bus 0.
2683 CONFIG_SYS_RTC_BUS_NUM
2685 If defined, then this indicates the I2C bus number for the RTC.
2686 If not defined, then U-Boot assumes that RTC is on I2C bus 0.
2688 CONFIG_SYS_DTT_BUS_NUM
2690 If defined, then this indicates the I2C bus number for the DTT.
2691 If not defined, then U-Boot assumes that DTT is on I2C bus 0.
2693 CONFIG_SYS_I2C_DTT_ADDR:
2695 If defined, specifies the I2C address of the DTT device.
2696 If not defined, then U-Boot uses predefined value for
2697 specified DTT device.
2699 CONFIG_SOFT_I2C_READ_REPEATED_START
2701 defining this will force the i2c_read() function in
2702 the soft_i2c driver to perform an I2C repeated start
2703 between writing the address pointer and reading the
2704 data. If this define is omitted the default behaviour
2705 of doing a stop-start sequence will be used. Most I2C
2706 devices can use either method, but some require one or
2709 - SPI Support: CONFIG_SPI
2711 Enables SPI driver (so far only tested with
2712 SPI EEPROM, also an instance works with Crystal A/D and
2713 D/As on the SACSng board)
2717 Enables the driver for SPI controller on SuperH. Currently
2718 only SH7757 is supported.
2722 Enables extended (16-bit) SPI EEPROM addressing.
2723 (symmetrical to CONFIG_I2C_X)
2727 Enables a software (bit-bang) SPI driver rather than
2728 using hardware support. This is a general purpose
2729 driver that only requires three general I/O port pins
2730 (two outputs, one input) to function. If this is
2731 defined, the board configuration must define several
2732 SPI configuration items (port pins to use, etc). For
2733 an example, see include/configs/sacsng.h.
2737 Enables a hardware SPI driver for general-purpose reads
2738 and writes. As with CONFIG_SOFT_SPI, the board configuration
2739 must define a list of chip-select function pointers.
2740 Currently supported on some MPC8xxx processors. For an
2741 example, see include/configs/mpc8349emds.h.
2745 Enables the driver for the SPI controllers on i.MX and MXC
2746 SoCs. Currently i.MX31/35/51 are supported.
2748 CONFIG_SYS_SPI_MXC_WAIT
2749 Timeout for waiting until spi transfer completed.
2750 default: (CONFIG_SYS_HZ/100) /* 10 ms */
2752 - FPGA Support: CONFIG_FPGA
2754 Enables FPGA subsystem.
2756 CONFIG_FPGA_<vendor>
2758 Enables support for specific chip vendors.
2761 CONFIG_FPGA_<family>
2763 Enables support for FPGA family.
2764 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX)
2768 Specify the number of FPGA devices to support.
2770 CONFIG_CMD_FPGA_LOADMK
2772 Enable support for fpga loadmk command
2774 CONFIG_CMD_FPGA_LOADP
2776 Enable support for fpga loadp command - load partial bitstream
2778 CONFIG_CMD_FPGA_LOADBP
2780 Enable support for fpga loadbp command - load partial bitstream
2783 CONFIG_SYS_FPGA_PROG_FEEDBACK
2785 Enable printing of hash marks during FPGA configuration.
2787 CONFIG_SYS_FPGA_CHECK_BUSY
2789 Enable checks on FPGA configuration interface busy
2790 status by the configuration function. This option
2791 will require a board or device specific function to
2796 If defined, a function that provides delays in the FPGA
2797 configuration driver.
2799 CONFIG_SYS_FPGA_CHECK_CTRLC
2800 Allow Control-C to interrupt FPGA configuration
2802 CONFIG_SYS_FPGA_CHECK_ERROR
2804 Check for configuration errors during FPGA bitfile
2805 loading. For example, abort during Virtex II
2806 configuration if the INIT_B line goes low (which
2807 indicated a CRC error).
2809 CONFIG_SYS_FPGA_WAIT_INIT
2811 Maximum time to wait for the INIT_B line to de-assert
2812 after PROB_B has been de-asserted during a Virtex II
2813 FPGA configuration sequence. The default time is 500
2816 CONFIG_SYS_FPGA_WAIT_BUSY
2818 Maximum time to wait for BUSY to de-assert during
2819 Virtex II FPGA configuration. The default is 5 ms.
2821 CONFIG_SYS_FPGA_WAIT_CONFIG
2823 Time to wait after FPGA configuration. The default is
2826 - Configuration Management:
2829 Some SoCs need special image types (e.g. U-Boot binary
2830 with a special header) as build targets. By defining
2831 CONFIG_BUILD_TARGET in the SoC / board header, this
2832 special image will be automatically built upon calling
2837 If defined, this string will be added to the U-Boot
2838 version information (U_BOOT_VERSION)
2840 - Vendor Parameter Protection:
2842 U-Boot considers the values of the environment
2843 variables "serial#" (Board Serial Number) and
2844 "ethaddr" (Ethernet Address) to be parameters that
2845 are set once by the board vendor / manufacturer, and
2846 protects these variables from casual modification by
2847 the user. Once set, these variables are read-only,
2848 and write or delete attempts are rejected. You can
2849 change this behaviour:
2851 If CONFIG_ENV_OVERWRITE is #defined in your config
2852 file, the write protection for vendor parameters is
2853 completely disabled. Anybody can change or delete
2856 Alternatively, if you #define _both_ CONFIG_ETHADDR
2857 _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
2858 Ethernet address is installed in the environment,
2859 which can be changed exactly ONCE by the user. [The
2860 serial# is unaffected by this, i. e. it remains
2863 The same can be accomplished in a more flexible way
2864 for any variable by configuring the type of access
2865 to allow for those variables in the ".flags" variable
2866 or define CONFIG_ENV_FLAGS_LIST_STATIC.
2871 Define this variable to enable the reservation of
2872 "protected RAM", i. e. RAM which is not overwritten
2873 by U-Boot. Define CONFIG_PRAM to hold the number of
2874 kB you want to reserve for pRAM. You can overwrite
2875 this default value by defining an environment
2876 variable "pram" to the number of kB you want to
2877 reserve. Note that the board info structure will
2878 still show the full amount of RAM. If pRAM is
2879 reserved, a new environment variable "mem" will
2880 automatically be defined to hold the amount of
2881 remaining RAM in a form that can be passed as boot
2882 argument to Linux, for instance like that:
2884 setenv bootargs ... mem=\${mem}
2887 This way you can tell Linux not to use this memory,
2888 either, which results in a memory region that will
2889 not be affected by reboots.
2891 *WARNING* If your board configuration uses automatic
2892 detection of the RAM size, you must make sure that
2893 this memory test is non-destructive. So far, the
2894 following board configurations are known to be
2897 IVMS8, IVML24, SPD8xx, TQM8xxL,
2898 HERMES, IP860, RPXlite, LWMON,
2901 - Access to physical memory region (> 4GB)
2902 Some basic support is provided for operations on memory not
2903 normally accessible to U-Boot - e.g. some architectures
2904 support access to more than 4GB of memory on 32-bit
2905 machines using physical address extension or similar.
2906 Define CONFIG_PHYSMEM to access this basic support, which
2907 currently only supports clearing the memory.
2912 Define this variable to stop the system in case of a
2913 fatal error, so that you have to reset it manually.
2914 This is probably NOT a good idea for an embedded
2915 system where you want the system to reboot
2916 automatically as fast as possible, but it may be
2917 useful during development since you can try to debug
2918 the conditions that lead to the situation.
2920 CONFIG_NET_RETRY_COUNT
2922 This variable defines the number of retries for
2923 network operations like ARP, RARP, TFTP, or BOOTP
2924 before giving up the operation. If not defined, a
2925 default value of 5 is used.
2929 Timeout waiting for an ARP reply in milliseconds.
2933 Timeout in milliseconds used in NFS protocol.
2934 If you encounter "ERROR: Cannot umount" in nfs command,
2935 try longer timeout such as
2936 #define CONFIG_NFS_TIMEOUT 10000UL
2938 - Command Interpreter:
2939 CONFIG_AUTO_COMPLETE
2941 Enable auto completion of commands using TAB.
2943 CONFIG_SYS_PROMPT_HUSH_PS2
2945 This defines the secondary prompt string, which is
2946 printed when the command interpreter needs more input
2947 to complete a command. Usually "> ".
2951 In the current implementation, the local variables
2952 space and global environment variables space are
2953 separated. Local variables are those you define by
2954 simply typing `name=value'. To access a local
2955 variable later on, you have write `$name' or
2956 `${name}'; to execute the contents of a variable
2957 directly type `$name' at the command prompt.
2959 Global environment variables are those you use
2960 setenv/printenv to work with. To run a command stored
2961 in such a variable, you need to use the run command,
2962 and you must not use the '$' sign to access them.
2964 To store commands and special characters in a
2965 variable, please use double quotation marks
2966 surrounding the whole text of the variable, instead
2967 of the backslashes before semicolons and special
2970 - Command Line Editing and History:
2971 CONFIG_CMDLINE_EDITING
2973 Enable editing and History functions for interactive
2974 command line input operations
2976 - Default Environment:
2977 CONFIG_EXTRA_ENV_SETTINGS
2979 Define this to contain any number of null terminated
2980 strings (variable = value pairs) that will be part of
2981 the default environment compiled into the boot image.
2983 For example, place something like this in your
2984 board's config file:
2986 #define CONFIG_EXTRA_ENV_SETTINGS \
2990 Warning: This method is based on knowledge about the
2991 internal format how the environment is stored by the
2992 U-Boot code. This is NOT an official, exported
2993 interface! Although it is unlikely that this format
2994 will change soon, there is no guarantee either.
2995 You better know what you are doing here.
2997 Note: overly (ab)use of the default environment is
2998 discouraged. Make sure to check other ways to preset
2999 the environment like the "source" command or the
3002 CONFIG_ENV_VARS_UBOOT_CONFIG
3004 Define this in order to add variables describing the
3005 U-Boot build configuration to the default environment.
3006 These will be named arch, cpu, board, vendor, and soc.
3008 Enabling this option will cause the following to be defined:
3016 CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG
3018 Define this in order to add variables describing certain
3019 run-time determined information about the hardware to the
3020 environment. These will be named board_name, board_rev.
3022 CONFIG_DELAY_ENVIRONMENT
3024 Normally the environment is loaded when the board is
3025 initialised so that it is available to U-Boot. This inhibits
3026 that so that the environment is not available until
3027 explicitly loaded later by U-Boot code. With CONFIG_OF_CONTROL
3028 this is instead controlled by the value of
3029 /config/load-environment.
3031 - DataFlash Support:
3032 CONFIG_HAS_DATAFLASH
3034 Defining this option enables DataFlash features and
3035 allows to read/write in Dataflash via the standard
3038 - Serial Flash support
3041 Defining this option enables SPI flash commands
3042 'sf probe/read/write/erase/update'.
3044 Usage requires an initial 'probe' to define the serial
3045 flash parameters, followed by read/write/erase/update
3048 The following defaults may be provided by the platform
3049 to handle the common case when only a single serial
3050 flash is present on the system.
3052 CONFIG_SF_DEFAULT_BUS Bus identifier
3053 CONFIG_SF_DEFAULT_CS Chip-select
3054 CONFIG_SF_DEFAULT_MODE (see include/spi.h)
3055 CONFIG_SF_DEFAULT_SPEED in Hz
3059 Define this option to include a destructive SPI flash
3062 CONFIG_SPI_FLASH_BAR Ban/Extended Addr Reg
3064 Define this option to use the Bank addr/Extended addr
3065 support on SPI flashes which has size > 16Mbytes.
3067 CONFIG_SF_DUAL_FLASH Dual flash memories
3069 Define this option to use dual flash support where two flash
3070 memories can be connected with a given cs line.
3071 Currently Xilinx Zynq qspi supports these type of connections.
3073 CONFIG_SYS_SPI_ST_ENABLE_WP_PIN
3074 enable the W#/Vpp signal to disable writing to the status
3075 register on ST MICRON flashes like the N25Q128.
3076 The status register write enable/disable bit, combined with
3077 the W#/VPP signal provides hardware data protection for the
3078 device as follows: When the enable/disable bit is set to 1,
3079 and the W#/VPP signal is driven LOW, the status register
3080 nonvolatile bits become read-only and the WRITE STATUS REGISTER
3081 operation will not execute. The only way to exit this
3082 hardware-protected mode is to drive W#/VPP HIGH.
3084 - SystemACE Support:
3087 Adding this option adds support for Xilinx SystemACE
3088 chips attached via some sort of local bus. The address
3089 of the chip must also be defined in the
3090 CONFIG_SYS_SYSTEMACE_BASE macro. For example:
3092 #define CONFIG_SYSTEMACE
3093 #define CONFIG_SYS_SYSTEMACE_BASE 0xf0000000
3095 When SystemACE support is added, the "ace" device type
3096 becomes available to the fat commands, i.e. fatls.
3098 - TFTP Fixed UDP Port:
3101 If this is defined, the environment variable tftpsrcp
3102 is used to supply the TFTP UDP source port value.
3103 If tftpsrcp isn't defined, the normal pseudo-random port
3104 number generator is used.
3106 Also, the environment variable tftpdstp is used to supply
3107 the TFTP UDP destination port value. If tftpdstp isn't
3108 defined, the normal port 69 is used.
3110 The purpose for tftpsrcp is to allow a TFTP server to
3111 blindly start the TFTP transfer using the pre-configured
3112 target IP address and UDP port. This has the effect of
3113 "punching through" the (Windows XP) firewall, allowing
3114 the remainder of the TFTP transfer to proceed normally.
3115 A better solution is to properly configure the firewall,
3116 but sometimes that is not allowed.
3121 This enables a generic 'hash' command which can produce
3122 hashes / digests from a few algorithms (e.g. SHA1, SHA256).
3126 Enable the hash verify command (hash -v). This adds to code
3129 CONFIG_SHA1 - This option enables support of hashing using SHA1
3130 algorithm. The hash is calculated in software.
3131 CONFIG_SHA256 - This option enables support of hashing using
3132 SHA256 algorithm. The hash is calculated in software.
3133 CONFIG_SHA_HW_ACCEL - This option enables hardware acceleration
3134 for SHA1/SHA256 hashing.
3135 This affects the 'hash' command and also the
3136 hash_lookup_algo() function.
3137 CONFIG_SHA_PROG_HW_ACCEL - This option enables
3138 hardware-acceleration for SHA1/SHA256 progressive hashing.
3139 Data can be streamed in a block at a time and the hashing
3140 is performed in hardware.
3142 Note: There is also a sha1sum command, which should perhaps
3143 be deprecated in favour of 'hash sha1'.
3145 - Freescale i.MX specific commands:
3146 CONFIG_CMD_HDMIDETECT
3147 This enables 'hdmidet' command which returns true if an
3148 HDMI monitor is detected. This command is i.MX 6 specific.
3151 This enables the 'bmode' (bootmode) command for forcing
3152 a boot from specific media.
3154 This is useful for forcing the ROM's usb downloader to
3155 activate upon a watchdog reset which is nice when iterating
3156 on U-Boot. Using the reset button or running bmode normal
3157 will set it back to normal. This command currently
3158 supports i.MX53 and i.MX6.
3163 This enables the RSA algorithm used for FIT image verification
3164 in U-Boot. See doc/uImage.FIT/signature.txt for more information.
3166 The Modular Exponentiation algorithm in RSA is implemented using
3167 driver model. So CONFIG_DM needs to be enabled by default for this
3168 library to function.
3170 The signing part is build into mkimage regardless of this
3171 option. The software based modular exponentiation is built into
3172 mkimage irrespective of this option.
3174 - bootcount support:
3175 CONFIG_BOOTCOUNT_LIMIT
3177 This enables the bootcounter support, see:
3178 http://www.denx.de/wiki/DULG/UBootBootCountLimit
3181 enable special bootcounter support on at91sam9xe based boards.
3183 enable special bootcounter support on blackfin based boards.
3185 enable special bootcounter support on da850 based boards.
3186 CONFIG_BOOTCOUNT_RAM
3187 enable support for the bootcounter in RAM
3188 CONFIG_BOOTCOUNT_I2C
3189 enable support for the bootcounter on an i2c (like RTC) device.
3190 CONFIG_SYS_I2C_RTC_ADDR = i2c chip address
3191 CONFIG_SYS_BOOTCOUNT_ADDR = i2c addr which is used for
3193 CONFIG_BOOTCOUNT_ALEN = address len
3195 - Show boot progress:
3196 CONFIG_SHOW_BOOT_PROGRESS
3198 Defining this option allows to add some board-
3199 specific code (calling a user-provided function
3200 "show_boot_progress(int)") that enables you to show
3201 the system's boot progress on some display (for
3202 example, some LED's) on your board. At the moment,
3203 the following checkpoints are implemented:
3205 - Detailed boot stage timing
3207 Define this option to get detailed timing of each stage
3208 of the boot process.
3210 CONFIG_BOOTSTAGE_USER_COUNT
3211 This is the number of available user bootstage records.
3212 Each time you call bootstage_mark(BOOTSTAGE_ID_ALLOC, ...)
3213 a new ID will be allocated from this stash. If you exceed
3214 the limit, recording will stop.
3216 CONFIG_BOOTSTAGE_REPORT
3217 Define this to print a report before boot, similar to this:
3219 Timer summary in microseconds:
3222 3,575,678 3,575,678 board_init_f start
3223 3,575,695 17 arch_cpu_init A9
3224 3,575,777 82 arch_cpu_init done
3225 3,659,598 83,821 board_init_r start
3226 3,910,375 250,777 main_loop
3227 29,916,167 26,005,792 bootm_start
3228 30,361,327 445,160 start_kernel
3230 CONFIG_CMD_BOOTSTAGE
3231 Add a 'bootstage' command which supports printing a report
3232 and un/stashing of bootstage data.
3234 CONFIG_BOOTSTAGE_FDT
3235 Stash the bootstage information in the FDT. A root 'bootstage'
3236 node is created with each bootstage id as a child. Each child
3237 has a 'name' property and either 'mark' containing the
3238 mark time in microsecond, or 'accum' containing the
3239 accumulated time for that bootstage id in microseconds.
3244 name = "board_init_f";
3253 Code in the Linux kernel can find this in /proc/devicetree.
3255 Legacy uImage format:
3258 1 common/cmd_bootm.c before attempting to boot an image
3259 -1 common/cmd_bootm.c Image header has bad magic number
3260 2 common/cmd_bootm.c Image header has correct magic number
3261 -2 common/cmd_bootm.c Image header has bad checksum
3262 3 common/cmd_bootm.c Image header has correct checksum
3263 -3 common/cmd_bootm.c Image data has bad checksum
3264 4 common/cmd_bootm.c Image data has correct checksum
3265 -4 common/cmd_bootm.c Image is for unsupported architecture
3266 5 common/cmd_bootm.c Architecture check OK
3267 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi)
3268 6 common/cmd_bootm.c Image Type check OK
3269 -6 common/cmd_bootm.c gunzip uncompression error
3270 -7 common/cmd_bootm.c Unimplemented compression type
3271 7 common/cmd_bootm.c Uncompression OK
3272 8 common/cmd_bootm.c No uncompress/copy overwrite error
3273 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX)
3275 9 common/image.c Start initial ramdisk verification
3276 -10 common/image.c Ramdisk header has bad magic number
3277 -11 common/image.c Ramdisk header has bad checksum
3278 10 common/image.c Ramdisk header is OK
3279 -12 common/image.c Ramdisk data has bad checksum
3280 11 common/image.c Ramdisk data has correct checksum
3281 12 common/image.c Ramdisk verification complete, start loading
3282 -13 common/image.c Wrong Image Type (not PPC Linux ramdisk)
3283 13 common/image.c Start multifile image verification
3284 14 common/image.c No initial ramdisk, no multifile, continue.
3286 15 arch/<arch>/lib/bootm.c All preparation done, transferring control to OS
3288 -30 arch/powerpc/lib/board.c Fatal error, hang the system
3289 -31 post/post.c POST test failed, detected by post_output_backlog()
3290 -32 post/post.c POST test failed, detected by post_run_single()
3292 34 common/cmd_doc.c before loading a Image from a DOC device
3293 -35 common/cmd_doc.c Bad usage of "doc" command
3294 35 common/cmd_doc.c correct usage of "doc" command
3295 -36 common/cmd_doc.c No boot device
3296 36 common/cmd_doc.c correct boot device
3297 -37 common/cmd_doc.c Unknown Chip ID on boot device
3298 37 common/cmd_doc.c correct chip ID found, device available
3299 -38 common/cmd_doc.c Read Error on boot device
3300 38 common/cmd_doc.c reading Image header from DOC device OK
3301 -39 common/cmd_doc.c Image header has bad magic number
3302 39 common/cmd_doc.c Image header has correct magic number
3303 -40 common/cmd_doc.c Error reading Image from DOC device
3304 40 common/cmd_doc.c Image header has correct magic number
3305 41 common/cmd_ide.c before loading a Image from a IDE device
3306 -42 common/cmd_ide.c Bad usage of "ide" command
3307 42 common/cmd_ide.c correct usage of "ide" command
3308 -43 common/cmd_ide.c No boot device
3309 43 common/cmd_ide.c boot device found
3310 -44 common/cmd_ide.c Device not available
3311 44 common/cmd_ide.c Device available
3312 -45 common/cmd_ide.c wrong partition selected
3313 45 common/cmd_ide.c partition selected
3314 -46 common/cmd_ide.c Unknown partition table
3315 46 common/cmd_ide.c valid partition table found
3316 -47 common/cmd_ide.c Invalid partition type
3317 47 common/cmd_ide.c correct partition type
3318 -48 common/cmd_ide.c Error reading Image Header on boot device
3319 48 common/cmd_ide.c reading Image Header from IDE device OK
3320 -49 common/cmd_ide.c Image header has bad magic number
3321 49 common/cmd_ide.c Image header has correct magic number
3322 -50 common/cmd_ide.c Image header has bad checksum
3323 50 common/cmd_ide.c Image header has correct checksum
3324 -51 common/cmd_ide.c Error reading Image from IDE device
3325 51 common/cmd_ide.c reading Image from IDE device OK
3326 52 common/cmd_nand.c before loading a Image from a NAND device
3327 -53 common/cmd_nand.c Bad usage of "nand" command
3328 53 common/cmd_nand.c correct usage of "nand" command
3329 -54 common/cmd_nand.c No boot device
3330 54 common/cmd_nand.c boot device found
3331 -55 common/cmd_nand.c Unknown Chip ID on boot device
3332 55 common/cmd_nand.c correct chip ID found, device available
3333 -56 common/cmd_nand.c Error reading Image Header on boot device
3334 56 common/cmd_nand.c reading Image Header from NAND device OK
3335 -57 common/cmd_nand.c Image header has bad magic number
3336 57 common/cmd_nand.c Image header has correct magic number
3337 -58 common/cmd_nand.c Error reading Image from NAND device
3338 58 common/cmd_nand.c reading Image from NAND device OK
3340 -60 common/env_common.c Environment has a bad CRC, using default
3342 64 net/eth.c starting with Ethernet configuration.
3343 -64 net/eth.c no Ethernet found.
3344 65 net/eth.c Ethernet found.
3346 -80 common/cmd_net.c usage wrong
3347 80 common/cmd_net.c before calling NetLoop()
3348 -81 common/cmd_net.c some error in NetLoop() occurred
3349 81 common/cmd_net.c NetLoop() back without error
3350 -82 common/cmd_net.c size == 0 (File with size 0 loaded)
3351 82 common/cmd_net.c trying automatic boot
3352 83 common/cmd_net.c running "source" command
3353 -83 common/cmd_net.c some error in automatic boot or "source" command
3354 84 common/cmd_net.c end without errors
3359 100 common/cmd_bootm.c Kernel FIT Image has correct format
3360 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format
3361 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration
3362 -101 common/cmd_bootm.c Can't get configuration for kernel subimage
3363 102 common/cmd_bootm.c Kernel unit name specified
3364 -103 common/cmd_bootm.c Can't get kernel subimage node offset
3365 103 common/cmd_bootm.c Found configuration node
3366 104 common/cmd_bootm.c Got kernel subimage node offset
3367 -104 common/cmd_bootm.c Kernel subimage hash verification failed
3368 105 common/cmd_bootm.c Kernel subimage hash verification OK
3369 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture
3370 106 common/cmd_bootm.c Architecture check OK
3371 -106 common/cmd_bootm.c Kernel subimage has wrong type
3372 107 common/cmd_bootm.c Kernel subimage type OK
3373 -107 common/cmd_bootm.c Can't get kernel subimage data/size
3374 108 common/cmd_bootm.c Got kernel subimage data/size
3375 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT)
3376 -109 common/cmd_bootm.c Can't get kernel subimage type
3377 -110 common/cmd_bootm.c Can't get kernel subimage comp
3378 -111 common/cmd_bootm.c Can't get kernel subimage os
3379 -112 common/cmd_bootm.c Can't get kernel subimage load address
3380 -113 common/cmd_bootm.c Image uncompress/copy overwrite error
3382 120 common/image.c Start initial ramdisk verification
3383 -120 common/image.c Ramdisk FIT image has incorrect format
3384 121 common/image.c Ramdisk FIT image has correct format
3385 122 common/image.c No ramdisk subimage unit name, using configuration
3386 -122 common/image.c Can't get configuration for ramdisk subimage
3387 123 common/image.c Ramdisk unit name specified
3388 -124 common/image.c Can't get ramdisk subimage node offset
3389 125 common/image.c Got ramdisk subimage node offset
3390 -125 common/image.c Ramdisk subimage hash verification failed
3391 126 common/image.c Ramdisk subimage hash verification OK
3392 -126 common/image.c Ramdisk subimage for unsupported architecture
3393 127 common/image.c Architecture check OK
3394 -127 common/image.c Can't get ramdisk subimage data/size
3395 128 common/image.c Got ramdisk subimage data/size
3396 129 common/image.c Can't get ramdisk load address
3397 -129 common/image.c Got ramdisk load address
3399 -130 common/cmd_doc.c Incorrect FIT image format
3400 131 common/cmd_doc.c FIT image format OK
3402 -140 common/cmd_ide.c Incorrect FIT image format
3403 141 common/cmd_ide.c FIT image format OK
3405 -150 common/cmd_nand.c Incorrect FIT image format
3406 151 common/cmd_nand.c FIT image format OK
3408 - legacy image format:
3409 CONFIG_IMAGE_FORMAT_LEGACY
3410 enables the legacy image format support in U-Boot.
3413 enabled if CONFIG_FIT_SIGNATURE is not defined.
3415 CONFIG_DISABLE_IMAGE_LEGACY
3416 disable the legacy image format
3418 This define is introduced, as the legacy image format is
3419 enabled per default for backward compatibility.
3421 - FIT image support:
3423 Enable support for the FIT uImage format.
3425 CONFIG_FIT_BEST_MATCH
3426 When no configuration is explicitly selected, default to the
3427 one whose fdt's compatibility field best matches that of
3428 U-Boot itself. A match is considered "best" if it matches the
3429 most specific compatibility entry of U-Boot's fdt's root node.
3430 The order of entries in the configuration's fdt is ignored.
3432 CONFIG_FIT_SIGNATURE
3433 This option enables signature verification of FIT uImages,
3434 using a hash signed and verified using RSA. If
3435 CONFIG_SHA_PROG_HW_ACCEL is defined, i.e support for progressive
3436 hashing is available using hardware, RSA library will use it.
3437 See doc/uImage.FIT/signature.txt for more details.
3439 WARNING: When relying on signed FIT images with required
3440 signature check the legacy image format is default
3441 disabled. If a board need legacy image format support
3442 enable this through CONFIG_IMAGE_FORMAT_LEGACY
3444 CONFIG_FIT_DISABLE_SHA256
3445 Supporting SHA256 hashes has quite an impact on binary size.
3446 For constrained systems sha256 hash support can be disabled
3449 - Standalone program support:
3450 CONFIG_STANDALONE_LOAD_ADDR
3452 This option defines a board specific value for the
3453 address where standalone program gets loaded, thus
3454 overwriting the architecture dependent default
3457 - Frame Buffer Address:
3460 Define CONFIG_FB_ADDR if you want to use specific
3461 address for frame buffer. This is typically the case
3462 when using a graphics controller has separate video
3463 memory. U-Boot will then place the frame buffer at
3464 the given address instead of dynamically reserving it
3465 in system RAM by calling lcd_setmem(), which grabs
3466 the memory for the frame buffer depending on the
3467 configured panel size.
3469 Please see board_init_f function.
3471 - Automatic software updates via TFTP server
3473 CONFIG_UPDATE_TFTP_CNT_MAX
3474 CONFIG_UPDATE_TFTP_MSEC_MAX
3476 These options enable and control the auto-update feature;
3477 for a more detailed description refer to doc/README.update.
3479 - MTD Support (mtdparts command, UBI support)
3482 Adds the MTD device infrastructure from the Linux kernel.
3483 Needed for mtdparts command support.
3485 CONFIG_MTD_PARTITIONS
3487 Adds the MTD partitioning infrastructure from the Linux
3488 kernel. Needed for UBI support.
3490 CONFIG_MTD_NAND_VERIFY_WRITE
3491 verify if the written data is correct reread.
3496 Adds commands for interacting with MTD partitions formatted
3497 with the UBI flash translation layer
3499 Requires also defining CONFIG_RBTREE
3501 CONFIG_UBI_SILENCE_MSG
3503 Make the verbose messages from UBI stop printing. This leaves
3504 warnings and errors enabled.
3507 CONFIG_MTD_UBI_WL_THRESHOLD
3508 This parameter defines the maximum difference between the highest
3509 erase counter value and the lowest erase counter value of eraseblocks
3510 of UBI devices. When this threshold is exceeded, UBI starts performing
3511 wear leveling by means of moving data from eraseblock with low erase
3512 counter to eraseblocks with high erase counter.
3514 The default value should be OK for SLC NAND flashes, NOR flashes and
3515 other flashes which have eraseblock life-cycle 100000 or more.
3516 However, in case of MLC NAND flashes which typically have eraseblock
3517 life-cycle less than 10000, the threshold should be lessened (e.g.,
3518 to 128 or 256, although it does not have to be power of 2).
3522 CONFIG_MTD_UBI_BEB_LIMIT
3523 This option specifies the maximum bad physical eraseblocks UBI
3524 expects on the MTD device (per 1024 eraseblocks). If the
3525 underlying flash does not admit of bad eraseblocks (e.g. NOR
3526 flash), this value is ignored.
3528 NAND datasheets often specify the minimum and maximum NVM
3529 (Number of Valid Blocks) for the flashes' endurance lifetime.
3530 The maximum expected bad eraseblocks per 1024 eraseblocks
3531 then can be calculated as "1024 * (1 - MinNVB / MaxNVB)",
3532 which gives 20 for most NANDs (MaxNVB is basically the total
3533 count of eraseblocks on the chip).
3535 To put it differently, if this value is 20, UBI will try to
3536 reserve about 1.9% of physical eraseblocks for bad blocks
3537 handling. And that will be 1.9% of eraseblocks on the entire
3538 NAND chip, not just the MTD partition UBI attaches. This means
3539 that if you have, say, a NAND flash chip admits maximum 40 bad
3540 eraseblocks, and it is split on two MTD partitions of the same
3541 size, UBI will reserve 40 eraseblocks when attaching a
3546 CONFIG_MTD_UBI_FASTMAP
3547 Fastmap is a mechanism which allows attaching an UBI device
3548 in nearly constant time. Instead of scanning the whole MTD device it
3549 only has to locate a checkpoint (called fastmap) on the device.
3550 The on-flash fastmap contains all information needed to attach
3551 the device. Using fastmap makes only sense on large devices where
3552 attaching by scanning takes long. UBI will not automatically install
3553 a fastmap on old images, but you can set the UBI parameter
3554 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT to 1 if you want so. Please note
3555 that fastmap-enabled images are still usable with UBI implementations
3556 without fastmap support. On typical flash devices the whole fastmap
3557 fits into one PEB. UBI will reserve PEBs to hold two fastmaps.
3559 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT
3560 Set this parameter to enable fastmap automatically on images
3567 Adds commands for interacting with UBI volumes formatted as
3568 UBIFS. UBIFS is read-only in u-boot.
3570 Requires UBI support as well as CONFIG_LZO
3572 CONFIG_UBIFS_SILENCE_MSG
3574 Make the verbose messages from UBIFS stop printing. This leaves
3575 warnings and errors enabled.
3579 Enable building of SPL globally.
3582 LDSCRIPT for linking the SPL binary.
3584 CONFIG_SPL_MAX_FOOTPRINT
3585 Maximum size in memory allocated to the SPL, BSS included.
3586 When defined, the linker checks that the actual memory
3587 used by SPL from _start to __bss_end does not exceed it.
3588 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
3589 must not be both defined at the same time.
3592 Maximum size of the SPL image (text, data, rodata, and
3593 linker lists sections), BSS excluded.
3594 When defined, the linker checks that the actual size does
3597 CONFIG_SPL_TEXT_BASE
3598 TEXT_BASE for linking the SPL binary.
3600 CONFIG_SPL_RELOC_TEXT_BASE
3601 Address to relocate to. If unspecified, this is equal to
3602 CONFIG_SPL_TEXT_BASE (i.e. no relocation is done).
3604 CONFIG_SPL_BSS_START_ADDR
3605 Link address for the BSS within the SPL binary.
3607 CONFIG_SPL_BSS_MAX_SIZE
3608 Maximum size in memory allocated to the SPL BSS.
3609 When defined, the linker checks that the actual memory used
3610 by SPL from __bss_start to __bss_end does not exceed it.
3611 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
3612 must not be both defined at the same time.
3615 Adress of the start of the stack SPL will use
3617 CONFIG_SPL_RELOC_STACK
3618 Adress of the start of the stack SPL will use after
3619 relocation. If unspecified, this is equal to
3622 CONFIG_SYS_SPL_MALLOC_START
3623 Starting address of the malloc pool used in SPL.
3625 CONFIG_SYS_SPL_MALLOC_SIZE
3626 The size of the malloc pool used in SPL.
3628 CONFIG_SPL_FRAMEWORK
3629 Enable the SPL framework under common/. This framework
3630 supports MMC, NAND and YMODEM loading of U-Boot and NAND
3631 NAND loading of the Linux Kernel.
3634 Enable booting directly to an OS from SPL.
3635 See also: doc/README.falcon
3637 CONFIG_SPL_DISPLAY_PRINT
3638 For ARM, enable an optional function to print more information
3639 about the running system.
3641 CONFIG_SPL_INIT_MINIMAL
3642 Arch init code should be built for a very small image
3644 CONFIG_SPL_LIBCOMMON_SUPPORT
3645 Support for common/libcommon.o in SPL binary
3647 CONFIG_SPL_LIBDISK_SUPPORT
3648 Support for disk/libdisk.o in SPL binary
3650 CONFIG_SPL_I2C_SUPPORT
3651 Support for drivers/i2c/libi2c.o in SPL binary
3653 CONFIG_SPL_GPIO_SUPPORT
3654 Support for drivers/gpio/libgpio.o in SPL binary
3656 CONFIG_SPL_MMC_SUPPORT
3657 Support for drivers/mmc/libmmc.o in SPL binary
3659 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_SECTOR,
3660 CONFIG_SYS_U_BOOT_MAX_SIZE_SECTORS,
3661 Address and partition on the MMC to load U-Boot from
3662 when the MMC is being used in raw mode.
3664 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_PARTITION
3665 Partition on the MMC to load U-Boot from when the MMC is being
3668 CONFIG_SYS_MMCSD_RAW_MODE_KERNEL_SECTOR
3669 Sector to load kernel uImage from when MMC is being
3670 used in raw mode (for Falcon mode)
3672 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTOR,
3673 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTORS
3674 Sector and number of sectors to load kernel argument
3675 parameters from when MMC is being used in raw mode
3678 CONFIG_SYS_MMCSD_FS_BOOT_PARTITION
3679 Partition on the MMC to load U-Boot from when the MMC is being
3682 CONFIG_SPL_FAT_SUPPORT
3683 Support for fs/fat/libfat.o in SPL binary
3685 CONFIG_SPL_EXT_SUPPORT
3686 Support for EXT filesystem in SPL binary
3688 CONFIG_SPL_FS_LOAD_PAYLOAD_NAME
3689 Filename to read to load U-Boot when reading from filesystem
3691 CONFIG_SPL_FS_LOAD_KERNEL_NAME
3692 Filename to read to load kernel uImage when reading
3693 from filesystem (for Falcon mode)
3695 CONFIG_SPL_FS_LOAD_ARGS_NAME
3696 Filename to read to load kernel argument parameters
3697 when reading from filesystem (for Falcon mode)
3699 CONFIG_SPL_MPC83XX_WAIT_FOR_NAND
3700 Set this for NAND SPL on PPC mpc83xx targets, so that
3701 start.S waits for the rest of the SPL to load before
3702 continuing (the hardware starts execution after just
3703 loading the first page rather than the full 4K).
3705 CONFIG_SPL_SKIP_RELOCATE
3706 Avoid SPL relocation
3708 CONFIG_SPL_NAND_BASE
3709 Include nand_base.c in the SPL. Requires
3710 CONFIG_SPL_NAND_DRIVERS.
3712 CONFIG_SPL_NAND_DRIVERS
3713 SPL uses normal NAND drivers, not minimal drivers.
3716 Include standard software ECC in the SPL
3718 CONFIG_SPL_NAND_SIMPLE
3719 Support for NAND boot using simple NAND drivers that
3720 expose the cmd_ctrl() interface.
3722 CONFIG_SPL_MTD_SUPPORT
3723 Support for the MTD subsystem within SPL. Useful for
3724 environment on NAND support within SPL.
3726 CONFIG_SPL_NAND_RAW_ONLY
3727 Support to boot only raw u-boot.bin images. Use this only
3728 if you need to save space.
3730 CONFIG_SPL_MPC8XXX_INIT_DDR_SUPPORT
3731 Set for the SPL on PPC mpc8xxx targets, support for
3732 drivers/ddr/fsl/libddr.o in SPL binary.
3734 CONFIG_SPL_COMMON_INIT_DDR
3735 Set for common ddr init with serial presence detect in
3738 CONFIG_SYS_NAND_5_ADDR_CYCLE, CONFIG_SYS_NAND_PAGE_COUNT,
3739 CONFIG_SYS_NAND_PAGE_SIZE, CONFIG_SYS_NAND_OOBSIZE,
3740 CONFIG_SYS_NAND_BLOCK_SIZE, CONFIG_SYS_NAND_BAD_BLOCK_POS,
3741 CONFIG_SYS_NAND_ECCPOS, CONFIG_SYS_NAND_ECCSIZE,
3742 CONFIG_SYS_NAND_ECCBYTES
3743 Defines the size and behavior of the NAND that SPL uses
3746 CONFIG_SPL_NAND_BOOT
3747 Add support NAND boot
3749 CONFIG_SYS_NAND_U_BOOT_OFFS
3750 Location in NAND to read U-Boot from
3752 CONFIG_SYS_NAND_U_BOOT_DST
3753 Location in memory to load U-Boot to
3755 CONFIG_SYS_NAND_U_BOOT_SIZE
3756 Size of image to load
3758 CONFIG_SYS_NAND_U_BOOT_START
3759 Entry point in loaded image to jump to
3761 CONFIG_SYS_NAND_HW_ECC_OOBFIRST
3762 Define this if you need to first read the OOB and then the
3763 data. This is used, for example, on davinci platforms.
3765 CONFIG_SPL_OMAP3_ID_NAND
3766 Support for an OMAP3-specific set of functions to return the
3767 ID and MFR of the first attached NAND chip, if present.
3769 CONFIG_SPL_SERIAL_SUPPORT
3770 Support for drivers/serial/libserial.o in SPL binary
3772 CONFIG_SPL_SPI_FLASH_SUPPORT
3773 Support for drivers/mtd/spi/libspi_flash.o in SPL binary
3775 CONFIG_SPL_SPI_SUPPORT
3776 Support for drivers/spi/libspi.o in SPL binary
3778 CONFIG_SPL_RAM_DEVICE
3779 Support for running image already present in ram, in SPL binary
3781 CONFIG_SPL_LIBGENERIC_SUPPORT
3782 Support for lib/libgeneric.o in SPL binary
3784 CONFIG_SPL_ENV_SUPPORT
3785 Support for the environment operating in SPL binary
3787 CONFIG_SPL_NET_SUPPORT
3788 Support for the net/libnet.o in SPL binary.
3789 It conflicts with SPL env from storage medium specified by
3790 CONFIG_ENV_IS_xxx but CONFIG_ENV_IS_NOWHERE
3793 Image offset to which the SPL should be padded before appending
3794 the SPL payload. By default, this is defined as
3795 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3796 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3797 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3800 Final target image containing SPL and payload. Some SPLs
3801 use an arch-specific makefile fragment instead, for
3802 example if more than one image needs to be produced.
3804 CONFIG_FIT_SPL_PRINT
3805 Printing information about a FIT image adds quite a bit of
3806 code to SPL. So this is normally disabled in SPL. Use this
3807 option to re-enable it. This will affect the output of the
3808 bootm command when booting a FIT image.
3812 Enable building of TPL globally.
3815 Image offset to which the TPL should be padded before appending
3816 the TPL payload. By default, this is defined as
3817 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3818 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3819 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3824 [so far only for SMDK2400 boards]
3826 - Modem support enable:
3827 CONFIG_MODEM_SUPPORT
3829 - RTS/CTS Flow control enable:
3832 - Modem debug support:
3833 CONFIG_MODEM_SUPPORT_DEBUG
3835 Enables debugging stuff (char screen[1024], dbg())
3836 for modem support. Useful only with BDI2000.
3838 - Interrupt support (PPC):
3840 There are common interrupt_init() and timer_interrupt()
3841 for all PPC archs. interrupt_init() calls interrupt_init_cpu()
3842 for CPU specific initialization. interrupt_init_cpu()
3843 should set decrementer_count to appropriate value. If
3844 CPU resets decrementer automatically after interrupt
3845 (ppc4xx) it should set decrementer_count to zero.
3846 timer_interrupt() calls timer_interrupt_cpu() for CPU
3847 specific handling. If board has watchdog / status_led
3848 / other_activity_monitor it works automatically from
3849 general timer_interrupt().
3853 In the target system modem support is enabled when a
3854 specific key (key combination) is pressed during
3855 power-on. Otherwise U-Boot will boot normally
3856 (autoboot). The key_pressed() function is called from
3857 board_init(). Currently key_pressed() is a dummy
3858 function, returning 1 and thus enabling modem
3861 If there are no modem init strings in the
3862 environment, U-Boot proceed to autoboot; the
3863 previous output (banner, info printfs) will be
3866 See also: doc/README.Modem
3868 Board initialization settings:
3869 ------------------------------
3871 During Initialization u-boot calls a number of board specific functions
3872 to allow the preparation of board specific prerequisites, e.g. pin setup
3873 before drivers are initialized. To enable these callbacks the
3874 following configuration macros have to be defined. Currently this is
3875 architecture specific, so please check arch/your_architecture/lib/board.c
3876 typically in board_init_f() and board_init_r().
3878 - CONFIG_BOARD_EARLY_INIT_F: Call board_early_init_f()
3879 - CONFIG_BOARD_EARLY_INIT_R: Call board_early_init_r()
3880 - CONFIG_BOARD_LATE_INIT: Call board_late_init()
3881 - CONFIG_BOARD_POSTCLK_INIT: Call board_postclk_init()
3883 Configuration Settings:
3884 -----------------------
3886 - CONFIG_SYS_SUPPORT_64BIT_DATA: Defined automatically if compiled as 64-bit.
3887 Optionally it can be defined to support 64-bit memory commands.
3889 - CONFIG_SYS_LONGHELP: Defined when you want long help messages included;
3890 undefine this when you're short of memory.
3892 - CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default
3893 width of the commands listed in the 'help' command output.
3895 - CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to
3896 prompt for user input.
3898 - CONFIG_SYS_CBSIZE: Buffer size for input from the Console
3900 - CONFIG_SYS_PBSIZE: Buffer size for Console output
3902 - CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands
3904 - CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to
3905 the application (usually a Linux kernel) when it is
3908 - CONFIG_SYS_BAUDRATE_TABLE:
3909 List of legal baudrate settings for this board.
3911 - CONFIG_SYS_CONSOLE_INFO_QUIET
3912 Suppress display of console information at boot.
3914 - CONFIG_SYS_CONSOLE_IS_IN_ENV
3915 If the board specific function
3916 extern int overwrite_console (void);
3917 returns 1, the stdin, stderr and stdout are switched to the
3918 serial port, else the settings in the environment are used.
3920 - CONFIG_SYS_CONSOLE_OVERWRITE_ROUTINE
3921 Enable the call to overwrite_console().
3923 - CONFIG_SYS_CONSOLE_ENV_OVERWRITE
3924 Enable overwrite of previous console environment settings.
3926 - CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END:
3927 Begin and End addresses of the area used by the
3930 - CONFIG_SYS_ALT_MEMTEST:
3931 Enable an alternate, more extensive memory test.
3933 - CONFIG_SYS_MEMTEST_SCRATCH:
3934 Scratch address used by the alternate memory test
3935 You only need to set this if address zero isn't writeable
3937 - CONFIG_SYS_MEM_TOP_HIDE (PPC only):
3938 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header,
3939 this specified memory area will get subtracted from the top
3940 (end) of RAM and won't get "touched" at all by U-Boot. By
3941 fixing up gd->ram_size the Linux kernel should gets passed
3942 the now "corrected" memory size and won't touch it either.
3943 This should work for arch/ppc and arch/powerpc. Only Linux
3944 board ports in arch/powerpc with bootwrapper support that
3945 recalculate the memory size from the SDRAM controller setup
3946 will have to get fixed in Linux additionally.
3948 This option can be used as a workaround for the 440EPx/GRx
3949 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't
3952 WARNING: Please make sure that this value is a multiple of
3953 the Linux page size (normally 4k). If this is not the case,
3954 then the end address of the Linux memory will be located at a
3955 non page size aligned address and this could cause major
3958 - CONFIG_SYS_LOADS_BAUD_CHANGE:
3959 Enable temporary baudrate change while serial download
3961 - CONFIG_SYS_SDRAM_BASE:
3962 Physical start address of SDRAM. _Must_ be 0 here.
3964 - CONFIG_SYS_MBIO_BASE:
3965 Physical start address of Motherboard I/O (if using a
3968 - CONFIG_SYS_FLASH_BASE:
3969 Physical start address of Flash memory.
3971 - CONFIG_SYS_MONITOR_BASE:
3972 Physical start address of boot monitor code (set by
3973 make config files to be same as the text base address
3974 (CONFIG_SYS_TEXT_BASE) used when linking) - same as
3975 CONFIG_SYS_FLASH_BASE when booting from flash.
3977 - CONFIG_SYS_MONITOR_LEN:
3978 Size of memory reserved for monitor code, used to
3979 determine _at_compile_time_ (!) if the environment is
3980 embedded within the U-Boot image, or in a separate
3983 - CONFIG_SYS_MALLOC_LEN:
3984 Size of DRAM reserved for malloc() use.
3986 - CONFIG_SYS_MALLOC_F_LEN
3987 Size of the malloc() pool for use before relocation. If
3988 this is defined, then a very simple malloc() implementation
3989 will become available before relocation. The address is just
3990 below the global data, and the stack is moved down to make
3993 This feature allocates regions with increasing addresses
3994 within the region. calloc() is supported, but realloc()
3995 is not available. free() is supported but does nothing.
3996 The memory will be freed (or in fact just forgotten) when
3997 U-Boot relocates itself.
3999 Pre-relocation malloc() is only supported on ARM and sandbox
4000 at present but is fairly easy to enable for other archs.
4002 - CONFIG_SYS_MALLOC_SIMPLE
4003 Provides a simple and small malloc() and calloc() for those
4004 boards which do not use the full malloc in SPL (which is
4005 enabled with CONFIG_SYS_SPL_MALLOC_START).
4007 - CONFIG_SYS_NONCACHED_MEMORY:
4008 Size of non-cached memory area. This area of memory will be
4009 typically located right below the malloc() area and mapped
4010 uncached in the MMU. This is useful for drivers that would
4011 otherwise require a lot of explicit cache maintenance. For
4012 some drivers it's also impossible to properly maintain the
4013 cache. For example if the regions that need to be flushed
4014 are not a multiple of the cache-line size, *and* padding
4015 cannot be allocated between the regions to align them (i.e.
4016 if the HW requires a contiguous array of regions, and the
4017 size of each region is not cache-aligned), then a flush of
4018 one region may result in overwriting data that hardware has
4019 written to another region in the same cache-line. This can
4020 happen for example in network drivers where descriptors for
4021 buffers are typically smaller than the CPU cache-line (e.g.
4022 16 bytes vs. 32 or 64 bytes).
4024 Non-cached memory is only supported on 32-bit ARM at present.
4026 - CONFIG_SYS_BOOTM_LEN:
4027 Normally compressed uImages are limited to an
4028 uncompressed size of 8 MBytes. If this is not enough,
4029 you can define CONFIG_SYS_BOOTM_LEN in your board config file
4030 to adjust this setting to your needs.
4032 - CONFIG_SYS_BOOTMAPSZ:
4033 Maximum size of memory mapped by the startup code of
4034 the Linux kernel; all data that must be processed by
4035 the Linux kernel (bd_info, boot arguments, FDT blob if
4036 used) must be put below this limit, unless "bootm_low"
4037 environment variable is defined and non-zero. In such case
4038 all data for the Linux kernel must be between "bootm_low"
4039 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ. The environment
4040 variable "bootm_mapsize" will override the value of
4041 CONFIG_SYS_BOOTMAPSZ. If CONFIG_SYS_BOOTMAPSZ is undefined,
4042 then the value in "bootm_size" will be used instead.
4044 - CONFIG_SYS_BOOT_RAMDISK_HIGH:
4045 Enable initrd_high functionality. If defined then the
4046 initrd_high feature is enabled and the bootm ramdisk subcommand
4049 - CONFIG_SYS_BOOT_GET_CMDLINE:
4050 Enables allocating and saving kernel cmdline in space between
4051 "bootm_low" and "bootm_low" + BOOTMAPSZ.
4053 - CONFIG_SYS_BOOT_GET_KBD:
4054 Enables allocating and saving a kernel copy of the bd_info in
4055 space between "bootm_low" and "bootm_low" + BOOTMAPSZ.
4057 - CONFIG_SYS_MAX_FLASH_BANKS:
4058 Max number of Flash memory banks
4060 - CONFIG_SYS_MAX_FLASH_SECT:
4061 Max number of sectors on a Flash chip
4063 - CONFIG_SYS_FLASH_ERASE_TOUT:
4064 Timeout for Flash erase operations (in ms)
4066 - CONFIG_SYS_FLASH_WRITE_TOUT:
4067 Timeout for Flash write operations (in ms)
4069 - CONFIG_SYS_FLASH_LOCK_TOUT
4070 Timeout for Flash set sector lock bit operation (in ms)
4072 - CONFIG_SYS_FLASH_UNLOCK_TOUT
4073 Timeout for Flash clear lock bits operation (in ms)
4075 - CONFIG_SYS_FLASH_PROTECTION
4076 If defined, hardware flash sectors protection is used
4077 instead of U-Boot software protection.
4079 - CONFIG_SYS_DIRECT_FLASH_TFTP:
4081 Enable TFTP transfers directly to flash memory;
4082 without this option such a download has to be
4083 performed in two steps: (1) download to RAM, and (2)
4084 copy from RAM to flash.
4086 The two-step approach is usually more reliable, since
4087 you can check if the download worked before you erase
4088 the flash, but in some situations (when system RAM is
4089 too limited to allow for a temporary copy of the
4090 downloaded image) this option may be very useful.
4092 - CONFIG_SYS_FLASH_CFI:
4093 Define if the flash driver uses extra elements in the
4094 common flash structure for storing flash geometry.
4096 - CONFIG_FLASH_CFI_DRIVER
4097 This option also enables the building of the cfi_flash driver
4098 in the drivers directory
4100 - CONFIG_FLASH_CFI_MTD
4101 This option enables the building of the cfi_mtd driver
4102 in the drivers directory. The driver exports CFI flash
4105 - CONFIG_SYS_FLASH_USE_BUFFER_WRITE
4106 Use buffered writes to flash.
4108 - CONFIG_FLASH_SPANSION_S29WS_N
4109 s29ws-n MirrorBit flash has non-standard addresses for buffered
4112 - CONFIG_SYS_FLASH_QUIET_TEST
4113 If this option is defined, the common CFI flash doesn't
4114 print it's warning upon not recognized FLASH banks. This
4115 is useful, if some of the configured banks are only
4116 optionally available.
4118 - CONFIG_FLASH_SHOW_PROGRESS
4119 If defined (must be an integer), print out countdown
4120 digits and dots. Recommended value: 45 (9..1) for 80
4121 column displays, 15 (3..1) for 40 column displays.
4123 - CONFIG_FLASH_VERIFY
4124 If defined, the content of the flash (destination) is compared
4125 against the source after the write operation. An error message
4126 will be printed when the contents are not identical.
4127 Please note that this option is useless in nearly all cases,
4128 since such flash programming errors usually are detected earlier
4129 while unprotecting/erasing/programming. Please only enable
4130 this option if you really know what you are doing.
4132 - CONFIG_SYS_RX_ETH_BUFFER:
4133 Defines the number of Ethernet receive buffers. On some
4134 Ethernet controllers it is recommended to set this value
4135 to 8 or even higher (EEPRO100 or 405 EMAC), since all
4136 buffers can be full shortly after enabling the interface
4137 on high Ethernet traffic.
4138 Defaults to 4 if not defined.
4140 - CONFIG_ENV_MAX_ENTRIES
4142 Maximum number of entries in the hash table that is used
4143 internally to store the environment settings. The default
4144 setting is supposed to be generous and should work in most
4145 cases. This setting can be used to tune behaviour; see
4146 lib/hashtable.c for details.
4148 - CONFIG_ENV_FLAGS_LIST_DEFAULT
4149 - CONFIG_ENV_FLAGS_LIST_STATIC
4150 Enable validation of the values given to environment variables when
4151 calling env set. Variables can be restricted to only decimal,
4152 hexadecimal, or boolean. If CONFIG_CMD_NET is also defined,
4153 the variables can also be restricted to IP address or MAC address.
4155 The format of the list is:
4156 type_attribute = [s|d|x|b|i|m]
4157 access_attribute = [a|r|o|c]
4158 attributes = type_attribute[access_attribute]
4159 entry = variable_name[:attributes]
4162 The type attributes are:
4163 s - String (default)
4166 b - Boolean ([1yYtT|0nNfF])
4170 The access attributes are:
4176 - CONFIG_ENV_FLAGS_LIST_DEFAULT
4177 Define this to a list (string) to define the ".flags"
4178 environment variable in the default or embedded environment.
4180 - CONFIG_ENV_FLAGS_LIST_STATIC
4181 Define this to a list (string) to define validation that
4182 should be done if an entry is not found in the ".flags"
4183 environment variable. To override a setting in the static
4184 list, simply add an entry for the same variable name to the
4187 - CONFIG_ENV_ACCESS_IGNORE_FORCE
4188 If defined, don't allow the -f switch to env set override variable
4191 - CONFIG_SYS_GENERIC_BOARD
4192 This selects the architecture-generic board system instead of the
4193 architecture-specific board files. It is intended to move boards
4194 to this new framework over time. Defining this will disable the
4195 arch/foo/lib/board.c file and use common/board_f.c and
4196 common/board_r.c instead. To use this option your architecture
4197 must support it (i.e. must define __HAVE_ARCH_GENERIC_BOARD in
4198 its config.mk file). If you find problems enabling this option on
4199 your board please report the problem and send patches!
4201 - CONFIG_OMAP_PLATFORM_RESET_TIME_MAX_USEC (OMAP only)
4202 This is set by OMAP boards for the max time that reset should
4203 be asserted. See doc/README.omap-reset-time for details on how
4204 the value can be calculated on a given board.
4207 If stdint.h is available with your toolchain you can define this
4208 option to enable it. You can provide option 'USE_STDINT=1' when
4209 building U-Boot to enable this.
4211 The following definitions that deal with the placement and management
4212 of environment data (variable area); in general, we support the
4213 following configurations:
4215 - CONFIG_BUILD_ENVCRC:
4217 Builds up envcrc with the target environment so that external utils
4218 may easily extract it and embed it in final U-Boot images.
4220 - CONFIG_ENV_IS_IN_FLASH:
4222 Define this if the environment is in flash memory.
4224 a) The environment occupies one whole flash sector, which is
4225 "embedded" in the text segment with the U-Boot code. This
4226 happens usually with "bottom boot sector" or "top boot
4227 sector" type flash chips, which have several smaller
4228 sectors at the start or the end. For instance, such a
4229 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In
4230 such a case you would place the environment in one of the
4231 4 kB sectors - with U-Boot code before and after it. With
4232 "top boot sector" type flash chips, you would put the
4233 environment in one of the last sectors, leaving a gap
4234 between U-Boot and the environment.
4236 - CONFIG_ENV_OFFSET:
4238 Offset of environment data (variable area) to the
4239 beginning of flash memory; for instance, with bottom boot
4240 type flash chips the second sector can be used: the offset
4241 for this sector is given here.
4243 CONFIG_ENV_OFFSET is used relative to CONFIG_SYS_FLASH_BASE.
4247 This is just another way to specify the start address of
4248 the flash sector containing the environment (instead of
4251 - CONFIG_ENV_SECT_SIZE:
4253 Size of the sector containing the environment.
4256 b) Sometimes flash chips have few, equal sized, BIG sectors.
4257 In such a case you don't want to spend a whole sector for
4262 If you use this in combination with CONFIG_ENV_IS_IN_FLASH
4263 and CONFIG_ENV_SECT_SIZE, you can specify to use only a part
4264 of this flash sector for the environment. This saves
4265 memory for the RAM copy of the environment.
4267 It may also save flash memory if you decide to use this
4268 when your environment is "embedded" within U-Boot code,
4269 since then the remainder of the flash sector could be used
4270 for U-Boot code. It should be pointed out that this is
4271 STRONGLY DISCOURAGED from a robustness point of view:
4272 updating the environment in flash makes it always
4273 necessary to erase the WHOLE sector. If something goes
4274 wrong before the contents has been restored from a copy in
4275 RAM, your target system will be dead.
4277 - CONFIG_ENV_ADDR_REDUND
4278 CONFIG_ENV_SIZE_REDUND
4280 These settings describe a second storage area used to hold
4281 a redundant copy of the environment data, so that there is
4282 a valid backup copy in case there is a power failure during
4283 a "saveenv" operation.
4285 BE CAREFUL! Any changes to the flash layout, and some changes to the
4286 source code will make it necessary to adapt <board>/u-boot.lds*
4290 - CONFIG_ENV_IS_IN_NVRAM:
4292 Define this if you have some non-volatile memory device
4293 (NVRAM, battery buffered SRAM) which you want to use for the
4299 These two #defines are used to determine the memory area you
4300 want to use for environment. It is assumed that this memory
4301 can just be read and written to, without any special
4304 BE CAREFUL! The first access to the environment happens quite early
4305 in U-Boot initialization (when we try to get the setting of for the
4306 console baudrate). You *MUST* have mapped your NVRAM area then, or
4309 Please note that even with NVRAM we still use a copy of the
4310 environment in RAM: we could work on NVRAM directly, but we want to
4311 keep settings there always unmodified except somebody uses "saveenv"
4312 to save the current settings.
4315 - CONFIG_ENV_IS_IN_EEPROM:
4317 Use this if you have an EEPROM or similar serial access
4318 device and a driver for it.
4320 - CONFIG_ENV_OFFSET:
4323 These two #defines specify the offset and size of the
4324 environment area within the total memory of your EEPROM.
4326 - CONFIG_SYS_I2C_EEPROM_ADDR:
4327 If defined, specified the chip address of the EEPROM device.
4328 The default address is zero.
4330 - CONFIG_SYS_I2C_EEPROM_BUS:
4331 If defined, specified the i2c bus of the EEPROM device.
4333 - CONFIG_SYS_EEPROM_PAGE_WRITE_BITS:
4334 If defined, the number of bits used to address bytes in a
4335 single page in the EEPROM device. A 64 byte page, for example
4336 would require six bits.
4338 - CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS:
4339 If defined, the number of milliseconds to delay between
4340 page writes. The default is zero milliseconds.
4342 - CONFIG_SYS_I2C_EEPROM_ADDR_LEN:
4343 The length in bytes of the EEPROM memory array address. Note
4344 that this is NOT the chip address length!
4346 - CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW:
4347 EEPROM chips that implement "address overflow" are ones
4348 like Catalyst 24WC04/08/16 which has 9/10/11 bits of
4349 address and the extra bits end up in the "chip address" bit
4350 slots. This makes a 24WC08 (1Kbyte) chip look like four 256
4353 Note that we consider the length of the address field to
4354 still be one byte because the extra address bits are hidden
4355 in the chip address.
4357 - CONFIG_SYS_EEPROM_SIZE:
4358 The size in bytes of the EEPROM device.
4360 - CONFIG_ENV_EEPROM_IS_ON_I2C
4361 define this, if you have I2C and SPI activated, and your
4362 EEPROM, which holds the environment, is on the I2C bus.
4364 - CONFIG_I2C_ENV_EEPROM_BUS
4365 if you have an Environment on an EEPROM reached over
4366 I2C muxes, you can define here, how to reach this
4367 EEPROM. For example:
4369 #define CONFIG_I2C_ENV_EEPROM_BUS 1
4371 EEPROM which holds the environment, is reached over
4372 a pca9547 i2c mux with address 0x70, channel 3.
4374 - CONFIG_ENV_IS_IN_DATAFLASH:
4376 Define this if you have a DataFlash memory device which you
4377 want to use for the environment.
4379 - CONFIG_ENV_OFFSET:
4383 These three #defines specify the offset and size of the
4384 environment area within the total memory of your DataFlash placed
4385 at the specified address.
4387 - CONFIG_ENV_IS_IN_SPI_FLASH:
4389 Define this if you have a SPI Flash memory device which you
4390 want to use for the environment.
4392 - CONFIG_ENV_OFFSET:
4395 These two #defines specify the offset and size of the
4396 environment area within the SPI Flash. CONFIG_ENV_OFFSET must be
4397 aligned to an erase sector boundary.
4399 - CONFIG_ENV_SECT_SIZE:
4401 Define the SPI flash's sector size.
4403 - CONFIG_ENV_OFFSET_REDUND (optional):
4405 This setting describes a second storage area of CONFIG_ENV_SIZE
4406 size used to hold a redundant copy of the environment data, so
4407 that there is a valid backup copy in case there is a power failure
4408 during a "saveenv" operation. CONFIG_ENV_OFFSET_RENDUND must be
4409 aligned to an erase sector boundary.
4411 - CONFIG_ENV_SPI_BUS (optional):
4412 - CONFIG_ENV_SPI_CS (optional):
4414 Define the SPI bus and chip select. If not defined they will be 0.
4416 - CONFIG_ENV_SPI_MAX_HZ (optional):
4418 Define the SPI max work clock. If not defined then use 1MHz.
4420 - CONFIG_ENV_SPI_MODE (optional):
4422 Define the SPI work mode. If not defined then use SPI_MODE_3.
4424 - CONFIG_ENV_IS_IN_REMOTE:
4426 Define this if you have a remote memory space which you
4427 want to use for the local device's environment.
4432 These two #defines specify the address and size of the
4433 environment area within the remote memory space. The
4434 local device can get the environment from remote memory
4435 space by SRIO or PCIE links.
4437 BE CAREFUL! For some special cases, the local device can not use
4438 "saveenv" command. For example, the local device will get the
4439 environment stored in a remote NOR flash by SRIO or PCIE link,
4440 but it can not erase, write this NOR flash by SRIO or PCIE interface.
4442 - CONFIG_ENV_IS_IN_NAND:
4444 Define this if you have a NAND device which you want to use
4445 for the environment.
4447 - CONFIG_ENV_OFFSET:
4450 These two #defines specify the offset and size of the environment
4451 area within the first NAND device. CONFIG_ENV_OFFSET must be
4452 aligned to an erase block boundary.
4454 - CONFIG_ENV_OFFSET_REDUND (optional):
4456 This setting describes a second storage area of CONFIG_ENV_SIZE
4457 size used to hold a redundant copy of the environment data, so
4458 that there is a valid backup copy in case there is a power failure
4459 during a "saveenv" operation. CONFIG_ENV_OFFSET_RENDUND must be
4460 aligned to an erase block boundary.
4462 - CONFIG_ENV_RANGE (optional):
4464 Specifies the length of the region in which the environment
4465 can be written. This should be a multiple of the NAND device's
4466 block size. Specifying a range with more erase blocks than
4467 are needed to hold CONFIG_ENV_SIZE allows bad blocks within
4468 the range to be avoided.
4470 - CONFIG_ENV_OFFSET_OOB (optional):
4472 Enables support for dynamically retrieving the offset of the
4473 environment from block zero's out-of-band data. The
4474 "nand env.oob" command can be used to record this offset.
4475 Currently, CONFIG_ENV_OFFSET_REDUND is not supported when
4476 using CONFIG_ENV_OFFSET_OOB.
4478 - CONFIG_NAND_ENV_DST
4480 Defines address in RAM to which the nand_spl code should copy the
4481 environment. If redundant environment is used, it will be copied to
4482 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE.
4484 - CONFIG_ENV_IS_IN_UBI:
4486 Define this if you have an UBI volume that you want to use for the
4487 environment. This has the benefit of wear-leveling the environment
4488 accesses, which is important on NAND.
4490 - CONFIG_ENV_UBI_PART:
4492 Define this to a string that is the mtd partition containing the UBI.
4494 - CONFIG_ENV_UBI_VOLUME:
4496 Define this to the name of the volume that you want to store the
4499 - CONFIG_ENV_UBI_VOLUME_REDUND:
4501 Define this to the name of another volume to store a second copy of
4502 the environment in. This will enable redundant environments in UBI.
4503 It is assumed that both volumes are in the same MTD partition.
4505 - CONFIG_UBI_SILENCE_MSG
4506 - CONFIG_UBIFS_SILENCE_MSG
4508 You will probably want to define these to avoid a really noisy system
4509 when storing the env in UBI.
4511 - CONFIG_ENV_IS_IN_FAT:
4512 Define this if you want to use the FAT file system for the environment.
4514 - FAT_ENV_INTERFACE:
4516 Define this to a string that is the name of the block device.
4518 - FAT_ENV_DEV_AND_PART:
4520 Define this to a string to specify the partition of the device. It can
4523 "D:P", "D:0", "D", "D:" or "D:auto" (D, P are integers. And P >= 1)
4524 - "D:P": device D partition P. Error occurs if device D has no
4527 - "D" or "D:": device D partition 1 if device D has partition
4528 table, or the whole device D if has no partition
4530 - "D:auto": first partition in device D with bootable flag set.
4531 If none, first valid partition in device D. If no
4532 partition table then means device D.
4536 It's a string of the FAT file name. This file use to store the
4540 This should be defined. Otherwise it cannot save the environment file.
4542 - CONFIG_ENV_IS_IN_MMC:
4544 Define this if you have an MMC device which you want to use for the
4547 - CONFIG_SYS_MMC_ENV_DEV:
4549 Specifies which MMC device the environment is stored in.
4551 - CONFIG_SYS_MMC_ENV_PART (optional):
4553 Specifies which MMC partition the environment is stored in. If not
4554 set, defaults to partition 0, the user area. Common values might be
4555 1 (first MMC boot partition), 2 (second MMC boot partition).
4557 - CONFIG_ENV_OFFSET:
4560 These two #defines specify the offset and size of the environment
4561 area within the specified MMC device.
4563 If offset is positive (the usual case), it is treated as relative to
4564 the start of the MMC partition. If offset is negative, it is treated
4565 as relative to the end of the MMC partition. This can be useful if
4566 your board may be fitted with different MMC devices, which have
4567 different sizes for the MMC partitions, and you always want the
4568 environment placed at the very end of the partition, to leave the
4569 maximum possible space before it, to store other data.
4571 These two values are in units of bytes, but must be aligned to an
4572 MMC sector boundary.
4574 - CONFIG_ENV_OFFSET_REDUND (optional):
4576 Specifies a second storage area, of CONFIG_ENV_SIZE size, used to
4577 hold a redundant copy of the environment data. This provides a
4578 valid backup copy in case the other copy is corrupted, e.g. due
4579 to a power failure during a "saveenv" operation.
4581 This value may also be positive or negative; this is handled in the
4582 same way as CONFIG_ENV_OFFSET.
4584 This value is also in units of bytes, but must also be aligned to
4585 an MMC sector boundary.
4587 - CONFIG_ENV_SIZE_REDUND (optional):
4589 This value need not be set, even when CONFIG_ENV_OFFSET_REDUND is
4590 set. If this value is set, it must be set to the same value as
4593 - CONFIG_SYS_SPI_INIT_OFFSET
4595 Defines offset to the initial SPI buffer area in DPRAM. The
4596 area is used at an early stage (ROM part) if the environment
4597 is configured to reside in the SPI EEPROM: We need a 520 byte
4598 scratch DPRAM area. It is used between the two initialization
4599 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems
4600 to be a good choice since it makes it far enough from the
4601 start of the data area as well as from the stack pointer.
4603 Please note that the environment is read-only until the monitor
4604 has been relocated to RAM and a RAM copy of the environment has been
4605 created; also, when using EEPROM you will have to use getenv_f()
4606 until then to read environment variables.
4608 The environment is protected by a CRC32 checksum. Before the monitor
4609 is relocated into RAM, as a result of a bad CRC you will be working
4610 with the compiled-in default environment - *silently*!!! [This is
4611 necessary, because the first environment variable we need is the
4612 "baudrate" setting for the console - if we have a bad CRC, we don't
4613 have any device yet where we could complain.]
4615 Note: once the monitor has been relocated, then it will complain if
4616 the default environment is used; a new CRC is computed as soon as you
4617 use the "saveenv" command to store a valid environment.
4619 - CONFIG_SYS_FAULT_ECHO_LINK_DOWN:
4620 Echo the inverted Ethernet link state to the fault LED.
4622 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR
4623 also needs to be defined.
4625 - CONFIG_SYS_FAULT_MII_ADDR:
4626 MII address of the PHY to check for the Ethernet link state.
4628 - CONFIG_NS16550_MIN_FUNCTIONS:
4629 Define this if you desire to only have use of the NS16550_init
4630 and NS16550_putc functions for the serial driver located at
4631 drivers/serial/ns16550.c. This option is useful for saving
4632 space for already greatly restricted images, including but not
4633 limited to NAND_SPL configurations.
4635 - CONFIG_DISPLAY_BOARDINFO
4636 Display information about the board that U-Boot is running on
4637 when U-Boot starts up. The board function checkboard() is called
4640 - CONFIG_DISPLAY_BOARDINFO_LATE
4641 Similar to the previous option, but display this information
4642 later, once stdio is running and output goes to the LCD, if
4645 - CONFIG_BOARD_SIZE_LIMIT:
4646 Maximum size of the U-Boot image. When defined, the
4647 build system checks that the actual size does not
4650 Low Level (hardware related) configuration options:
4651 ---------------------------------------------------
4653 - CONFIG_SYS_CACHELINE_SIZE:
4654 Cache Line Size of the CPU.
4656 - CONFIG_SYS_DEFAULT_IMMR:
4657 Default address of the IMMR after system reset.
4659 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU,
4660 and RPXsuper) to be able to adjust the position of
4661 the IMMR register after a reset.
4663 - CONFIG_SYS_CCSRBAR_DEFAULT:
4664 Default (power-on reset) physical address of CCSR on Freescale
4667 - CONFIG_SYS_CCSRBAR:
4668 Virtual address of CCSR. On a 32-bit build, this is typically
4669 the same value as CONFIG_SYS_CCSRBAR_DEFAULT.
4671 CONFIG_SYS_DEFAULT_IMMR must also be set to this value,
4672 for cross-platform code that uses that macro instead.
4674 - CONFIG_SYS_CCSRBAR_PHYS:
4675 Physical address of CCSR. CCSR can be relocated to a new
4676 physical address, if desired. In this case, this macro should
4677 be set to that address. Otherwise, it should be set to the
4678 same value as CONFIG_SYS_CCSRBAR_DEFAULT. For example, CCSR
4679 is typically relocated on 36-bit builds. It is recommended
4680 that this macro be defined via the _HIGH and _LOW macros:
4682 #define CONFIG_SYS_CCSRBAR_PHYS ((CONFIG_SYS_CCSRBAR_PHYS_HIGH
4683 * 1ull) << 32 | CONFIG_SYS_CCSRBAR_PHYS_LOW)
4685 - CONFIG_SYS_CCSRBAR_PHYS_HIGH:
4686 Bits 33-36 of CONFIG_SYS_CCSRBAR_PHYS. This value is typically
4687 either 0 (32-bit build) or 0xF (36-bit build). This macro is
4688 used in assembly code, so it must not contain typecasts or
4689 integer size suffixes (e.g. "ULL").
4691 - CONFIG_SYS_CCSRBAR_PHYS_LOW:
4692 Lower 32-bits of CONFIG_SYS_CCSRBAR_PHYS. This macro is
4693 used in assembly code, so it must not contain typecasts or
4694 integer size suffixes (e.g. "ULL").
4696 - CONFIG_SYS_CCSR_DO_NOT_RELOCATE:
4697 If this macro is defined, then CONFIG_SYS_CCSRBAR_PHYS will be
4698 forced to a value that ensures that CCSR is not relocated.
4700 - Floppy Disk Support:
4701 CONFIG_SYS_FDC_DRIVE_NUMBER
4703 the default drive number (default value 0)
4705 CONFIG_SYS_ISA_IO_STRIDE
4707 defines the spacing between FDC chipset registers
4710 CONFIG_SYS_ISA_IO_OFFSET
4712 defines the offset of register from address. It
4713 depends on which part of the data bus is connected to
4714 the FDC chipset. (default value 0)
4716 If CONFIG_SYS_ISA_IO_STRIDE CONFIG_SYS_ISA_IO_OFFSET and
4717 CONFIG_SYS_FDC_DRIVE_NUMBER are undefined, they take their
4720 if CONFIG_SYS_FDC_HW_INIT is defined, then the function
4721 fdc_hw_init() is called at the beginning of the FDC
4722 setup. fdc_hw_init() must be provided by the board
4723 source code. It is used to make hardware-dependent
4727 Most IDE controllers were designed to be connected with PCI
4728 interface. Only few of them were designed for AHB interface.
4729 When software is doing ATA command and data transfer to
4730 IDE devices through IDE-AHB controller, some additional
4731 registers accessing to these kind of IDE-AHB controller
4734 - CONFIG_SYS_IMMR: Physical address of the Internal Memory.
4735 DO NOT CHANGE unless you know exactly what you're
4736 doing! (11-4) [MPC8xx/82xx systems only]
4738 - CONFIG_SYS_INIT_RAM_ADDR:
4740 Start address of memory area that can be used for
4741 initial data and stack; please note that this must be
4742 writable memory that is working WITHOUT special
4743 initialization, i. e. you CANNOT use normal RAM which
4744 will become available only after programming the
4745 memory controller and running certain initialization
4748 U-Boot uses the following memory types:
4749 - MPC8xx and MPC8260: IMMR (internal memory of the CPU)
4750 - MPC824X: data cache
4751 - PPC4xx: data cache
4753 - CONFIG_SYS_GBL_DATA_OFFSET:
4755 Offset of the initial data structure in the memory
4756 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually
4757 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial
4758 data is located at the end of the available space
4759 (sometimes written as (CONFIG_SYS_INIT_RAM_SIZE -
4760 CONFIG_SYS_INIT_DATA_SIZE), and the initial stack is just
4761 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR +
4762 CONFIG_SYS_GBL_DATA_OFFSET) downward.
4765 On the MPC824X (or other systems that use the data
4766 cache for initial memory) the address chosen for
4767 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must
4768 point to an otherwise UNUSED address space between
4769 the top of RAM and the start of the PCI space.
4771 - CONFIG_SYS_SIUMCR: SIU Module Configuration (11-6)
4773 - CONFIG_SYS_SYPCR: System Protection Control (11-9)
4775 - CONFIG_SYS_TBSCR: Time Base Status and Control (11-26)
4777 - CONFIG_SYS_PISCR: Periodic Interrupt Status and Control (11-31)
4779 - CONFIG_SYS_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30)
4781 - CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27)
4783 - CONFIG_SYS_OR_TIMING_SDRAM:
4786 - CONFIG_SYS_MAMR_PTA:
4787 periodic timer for refresh
4789 - CONFIG_SYS_DER: Debug Event Register (37-47)
4791 - FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM,
4792 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP,
4793 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM,
4794 CONFIG_SYS_BR1_PRELIM:
4795 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
4797 - SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
4798 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM,
4799 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM:
4800 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
4802 - CONFIG_SYS_MAMR_PTA, CONFIG_SYS_MPTPR_2BK_4K, CONFIG_SYS_MPTPR_1BK_4K, CONFIG_SYS_MPTPR_2BK_8K,
4803 CONFIG_SYS_MPTPR_1BK_8K, CONFIG_SYS_MAMR_8COL, CONFIG_SYS_MAMR_9COL:
4804 Machine Mode Register and Memory Periodic Timer
4805 Prescaler definitions (SDRAM timing)
4807 - CONFIG_SYS_I2C_UCODE_PATCH, CONFIG_SYS_I2C_DPMEM_OFFSET [0x1FC0]:
4808 enable I2C microcode relocation patch (MPC8xx);
4809 define relocation offset in DPRAM [DSP2]
4811 - CONFIG_SYS_SMC_UCODE_PATCH, CONFIG_SYS_SMC_DPMEM_OFFSET [0x1FC0]:
4812 enable SMC microcode relocation patch (MPC8xx);
4813 define relocation offset in DPRAM [SMC1]
4815 - CONFIG_SYS_SPI_UCODE_PATCH, CONFIG_SYS_SPI_DPMEM_OFFSET [0x1FC0]:
4816 enable SPI microcode relocation patch (MPC8xx);
4817 define relocation offset in DPRAM [SCC4]
4819 - CONFIG_SYS_USE_OSCCLK:
4820 Use OSCM clock mode on MBX8xx board. Be careful,
4821 wrong setting might damage your board. Read
4822 doc/README.MBX before setting this variable!
4824 - CONFIG_SYS_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only)
4825 Offset of the bootmode word in DPRAM used by post
4826 (Power On Self Tests). This definition overrides
4827 #define'd default value in commproc.h resp.
4830 - CONFIG_SYS_PCI_SLV_MEM_LOCAL, CONFIG_SYS_PCI_SLV_MEM_BUS, CONFIG_SYS_PICMR0_MASK_ATTRIB,
4831 CONFIG_SYS_PCI_MSTR0_LOCAL, CONFIG_SYS_PCIMSK0_MASK, CONFIG_SYS_PCI_MSTR1_LOCAL,
4832 CONFIG_SYS_PCIMSK1_MASK, CONFIG_SYS_PCI_MSTR_MEM_LOCAL, CONFIG_SYS_PCI_MSTR_MEM_BUS,
4833 CONFIG_SYS_CPU_PCI_MEM_START, CONFIG_SYS_PCI_MSTR_MEM_SIZE, CONFIG_SYS_POCMR0_MASK_ATTRIB,
4834 CONFIG_SYS_PCI_MSTR_MEMIO_LOCAL, CONFIG_SYS_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START,
4835 CONFIG_SYS_PCI_MSTR_MEMIO_SIZE, CONFIG_SYS_POCMR1_MASK_ATTRIB, CONFIG_SYS_PCI_MSTR_IO_LOCAL,
4836 CONFIG_SYS_PCI_MSTR_IO_BUS, CONFIG_SYS_CPU_PCI_IO_START, CONFIG_SYS_PCI_MSTR_IO_SIZE,
4837 CONFIG_SYS_POCMR2_MASK_ATTRIB: (MPC826x only)
4838 Overrides the default PCI memory map in arch/powerpc/cpu/mpc8260/pci.c if set.
4840 - CONFIG_PCI_DISABLE_PCIE:
4841 Disable PCI-Express on systems where it is supported but not
4844 - CONFIG_PCI_ENUM_ONLY
4845 Only scan through and get the devices on the buses.
4846 Don't do any setup work, presumably because someone or
4847 something has already done it, and we don't need to do it
4848 a second time. Useful for platforms that are pre-booted
4849 by coreboot or similar.
4851 - CONFIG_PCI_INDIRECT_BRIDGE:
4852 Enable support for indirect PCI bridges.
4855 Chip has SRIO or not
4858 Board has SRIO 1 port available
4861 Board has SRIO 2 port available
4863 - CONFIG_SRIO_PCIE_BOOT_MASTER
4864 Board can support master function for Boot from SRIO and PCIE
4866 - CONFIG_SYS_SRIOn_MEM_VIRT:
4867 Virtual Address of SRIO port 'n' memory region
4869 - CONFIG_SYS_SRIOn_MEM_PHYS:
4870 Physical Address of SRIO port 'n' memory region
4872 - CONFIG_SYS_SRIOn_MEM_SIZE:
4873 Size of SRIO port 'n' memory region
4875 - CONFIG_SYS_NAND_BUSWIDTH_16BIT
4876 Defined to tell the NAND controller that the NAND chip is using
4878 Not all NAND drivers use this symbol.
4879 Example of drivers that use it:
4880 - drivers/mtd/nand/ndfc.c
4881 - drivers/mtd/nand/mxc_nand.c
4883 - CONFIG_SYS_NDFC_EBC0_CFG
4884 Sets the EBC0_CFG register for the NDFC. If not defined
4885 a default value will be used.
4888 Get DDR timing information from an I2C EEPROM. Common
4889 with pluggable memory modules such as SODIMMs
4892 I2C address of the SPD EEPROM
4894 - CONFIG_SYS_SPD_BUS_NUM
4895 If SPD EEPROM is on an I2C bus other than the first
4896 one, specify here. Note that the value must resolve
4897 to something your driver can deal with.
4899 - CONFIG_SYS_DDR_RAW_TIMING
4900 Get DDR timing information from other than SPD. Common with
4901 soldered DDR chips onboard without SPD. DDR raw timing
4902 parameters are extracted from datasheet and hard-coded into
4903 header files or board specific files.
4905 - CONFIG_FSL_DDR_INTERACTIVE
4906 Enable interactive DDR debugging. See doc/README.fsl-ddr.
4908 - CONFIG_FSL_DDR_SYNC_REFRESH
4909 Enable sync of refresh for multiple controllers.
4911 - CONFIG_SYS_83XX_DDR_USES_CS0
4912 Only for 83xx systems. If specified, then DDR should
4913 be configured using CS0 and CS1 instead of CS2 and CS3.
4915 - CONFIG_ETHER_ON_FEC[12]
4916 Define to enable FEC[12] on a 8xx series processor.
4918 - CONFIG_FEC[12]_PHY
4919 Define to the hardcoded PHY address which corresponds
4920 to the given FEC; i. e.
4921 #define CONFIG_FEC1_PHY 4
4922 means that the PHY with address 4 is connected to FEC1
4924 When set to -1, means to probe for first available.
4926 - CONFIG_FEC[12]_PHY_NORXERR
4927 The PHY does not have a RXERR line (RMII only).
4928 (so program the FEC to ignore it).
4931 Enable RMII mode for all FECs.
4932 Note that this is a global option, we can't
4933 have one FEC in standard MII mode and another in RMII mode.
4935 - CONFIG_CRC32_VERIFY
4936 Add a verify option to the crc32 command.
4939 => crc32 -v <address> <count> <crc32>
4941 Where address/count indicate a memory area
4942 and crc32 is the correct crc32 which the
4946 Add the "loopw" memory command. This only takes effect if
4947 the memory commands are activated globally (CONFIG_CMD_MEM).
4950 Add the "mdc" and "mwc" memory commands. These are cyclic
4955 This command will print 4 bytes (10,11,12,13) each 500 ms.
4957 => mwc.l 100 12345678 10
4958 This command will write 12345678 to address 100 all 10 ms.
4960 This only takes effect if the memory commands are activated
4961 globally (CONFIG_CMD_MEM).
4963 - CONFIG_SKIP_LOWLEVEL_INIT
4964 [ARM, NDS32, MIPS only] If this variable is defined, then certain
4965 low level initializations (like setting up the memory
4966 controller) are omitted and/or U-Boot does not
4967 relocate itself into RAM.
4969 Normally this variable MUST NOT be defined. The only
4970 exception is when U-Boot is loaded (to RAM) by some
4971 other boot loader or by a debugger which performs
4972 these initializations itself.
4975 Modifies the behaviour of start.S when compiling a loader
4976 that is executed before the actual U-Boot. E.g. when
4977 compiling a NAND SPL.
4980 Modifies the behaviour of start.S when compiling a loader
4981 that is executed after the SPL and before the actual U-Boot.
4982 It is loaded by the SPL.
4984 - CONFIG_SYS_MPC85XX_NO_RESETVEC
4985 Only for 85xx systems. If this variable is specified, the section
4986 .resetvec is not kept and the section .bootpg is placed in the
4987 previous 4k of the .text section.
4989 - CONFIG_ARCH_MAP_SYSMEM
4990 Generally U-Boot (and in particular the md command) uses
4991 effective address. It is therefore not necessary to regard
4992 U-Boot address as virtual addresses that need to be translated
4993 to physical addresses. However, sandbox requires this, since
4994 it maintains its own little RAM buffer which contains all
4995 addressable memory. This option causes some memory accesses
4996 to be mapped through map_sysmem() / unmap_sysmem().
4998 - CONFIG_USE_ARCH_MEMCPY
4999 CONFIG_USE_ARCH_MEMSET
5000 If these options are used a optimized version of memcpy/memset will
5001 be used if available. These functions may be faster under some
5002 conditions but may increase the binary size.
5004 - CONFIG_X86_RESET_VECTOR
5005 If defined, the x86 reset vector code is included. This is not
5006 needed when U-Boot is running from Coreboot.
5009 Defines the MPU clock speed (in MHz).
5011 NOTE : currently only supported on AM335x platforms.
5013 - CONFIG_SPL_AM33XX_ENABLE_RTC32K_OSC:
5014 Enables the RTC32K OSC on AM33xx based plattforms
5016 - CONFIG_SYS_NAND_NO_SUBPAGE_WRITE
5017 Option to disable subpage write in NAND driver
5018 driver that uses this:
5019 drivers/mtd/nand/davinci_nand.c
5021 Freescale QE/FMAN Firmware Support:
5022 -----------------------------------
5024 The Freescale QUICCEngine (QE) and Frame Manager (FMAN) both support the
5025 loading of "firmware", which is encoded in the QE firmware binary format.
5026 This firmware often needs to be loaded during U-Boot booting, so macros
5027 are used to identify the storage device (NOR flash, SPI, etc) and the address
5030 - CONFIG_SYS_FMAN_FW_ADDR
5031 The address in the storage device where the FMAN microcode is located. The
5032 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
5035 - CONFIG_SYS_QE_FW_ADDR
5036 The address in the storage device where the QE microcode is located. The
5037 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
5040 - CONFIG_SYS_QE_FMAN_FW_LENGTH
5041 The maximum possible size of the firmware. The firmware binary format
5042 has a field that specifies the actual size of the firmware, but it
5043 might not be possible to read any part of the firmware unless some
5044 local storage is allocated to hold the entire firmware first.
5046 - CONFIG_SYS_QE_FMAN_FW_IN_NOR
5047 Specifies that QE/FMAN firmware is located in NOR flash, mapped as
5048 normal addressable memory via the LBC. CONFIG_SYS_FMAN_FW_ADDR is the
5049 virtual address in NOR flash.
5051 - CONFIG_SYS_QE_FMAN_FW_IN_NAND
5052 Specifies that QE/FMAN firmware is located in NAND flash.
5053 CONFIG_SYS_FMAN_FW_ADDR is the offset within NAND flash.
5055 - CONFIG_SYS_QE_FMAN_FW_IN_MMC
5056 Specifies that QE/FMAN firmware is located on the primary SD/MMC
5057 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
5059 - CONFIG_SYS_QE_FMAN_FW_IN_SPIFLASH
5060 Specifies that QE/FMAN firmware is located on the primary SPI
5061 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
5063 - CONFIG_SYS_QE_FMAN_FW_IN_REMOTE
5064 Specifies that QE/FMAN firmware is located in the remote (master)
5065 memory space. CONFIG_SYS_FMAN_FW_ADDR is a virtual address which
5066 can be mapped from slave TLB->slave LAW->slave SRIO or PCIE outbound
5067 window->master inbound window->master LAW->the ucode address in
5068 master's memory space.
5070 Freescale Layerscape Management Complex Firmware Support:
5071 ---------------------------------------------------------
5072 The Freescale Layerscape Management Complex (MC) supports the loading of
5074 This firmware often needs to be loaded during U-Boot booting, so macros
5075 are used to identify the storage device (NOR flash, SPI, etc) and the address
5078 - CONFIG_FSL_MC_ENET
5079 Enable the MC driver for Layerscape SoCs.
5081 - CONFIG_SYS_LS_MC_FW_ADDR
5082 The address in the storage device where the firmware is located. The
5083 meaning of this address depends on which CONFIG_SYS_LS_MC_FW_IN_xxx macro
5086 - CONFIG_SYS_LS_MC_FW_LENGTH
5087 The maximum possible size of the firmware. The firmware binary format
5088 has a field that specifies the actual size of the firmware, but it
5089 might not be possible to read any part of the firmware unless some
5090 local storage is allocated to hold the entire firmware first.
5092 - CONFIG_SYS_LS_MC_FW_IN_NOR
5093 Specifies that MC firmware is located in NOR flash, mapped as
5094 normal addressable memory via the LBC. CONFIG_SYS_LS_MC_FW_ADDR is the
5095 virtual address in NOR flash.
5097 Building the Software:
5098 ======================
5100 Building U-Boot has been tested in several native build environments
5101 and in many different cross environments. Of course we cannot support
5102 all possibly existing versions of cross development tools in all
5103 (potentially obsolete) versions. In case of tool chain problems we
5104 recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK)
5105 which is extensively used to build and test U-Boot.
5107 If you are not using a native environment, it is assumed that you
5108 have GNU cross compiling tools available in your path. In this case,
5109 you must set the environment variable CROSS_COMPILE in your shell.
5110 Note that no changes to the Makefile or any other source files are
5111 necessary. For example using the ELDK on a 4xx CPU, please enter:
5113 $ CROSS_COMPILE=ppc_4xx-
5114 $ export CROSS_COMPILE
5116 Note: If you wish to generate Windows versions of the utilities in
5117 the tools directory you can use the MinGW toolchain
5118 (http://www.mingw.org). Set your HOST tools to the MinGW
5119 toolchain and execute 'make tools'. For example:
5121 $ make HOSTCC=i586-mingw32msvc-gcc HOSTSTRIP=i586-mingw32msvc-strip tools
5123 Binaries such as tools/mkimage.exe will be created which can
5124 be executed on computers running Windows.
5126 U-Boot is intended to be simple to build. After installing the
5127 sources you must configure U-Boot for one specific board type. This
5132 where "NAME_defconfig" is the name of one of the existing configu-
5133 rations; see boards.cfg for supported names.
5135 Note: for some board special configuration names may exist; check if
5136 additional information is available from the board vendor; for
5137 instance, the TQM823L systems are available without (standard)
5138 or with LCD support. You can select such additional "features"
5139 when choosing the configuration, i. e.
5141 make TQM823L_defconfig
5142 - will configure for a plain TQM823L, i. e. no LCD support
5144 make TQM823L_LCD_defconfig
5145 - will configure for a TQM823L with U-Boot console on LCD
5150 Finally, type "make all", and you should get some working U-Boot
5151 images ready for download to / installation on your system:
5153 - "u-boot.bin" is a raw binary image
5154 - "u-boot" is an image in ELF binary format
5155 - "u-boot.srec" is in Motorola S-Record format
5157 By default the build is performed locally and the objects are saved
5158 in the source directory. One of the two methods can be used to change
5159 this behavior and build U-Boot to some external directory:
5161 1. Add O= to the make command line invocations:
5163 make O=/tmp/build distclean
5164 make O=/tmp/build NAME_defconfig
5165 make O=/tmp/build all
5167 2. Set environment variable KBUILD_OUTPUT to point to the desired location:
5169 export KBUILD_OUTPUT=/tmp/build
5174 Note that the command line "O=" setting overrides the KBUILD_OUTPUT environment
5178 Please be aware that the Makefiles assume you are using GNU make, so
5179 for instance on NetBSD you might need to use "gmake" instead of
5183 If the system board that you have is not listed, then you will need
5184 to port U-Boot to your hardware platform. To do this, follow these
5187 1. Add a new configuration option for your board to the toplevel
5188 "boards.cfg" file, using the existing entries as examples.
5189 Follow the instructions there to keep the boards in order.
5190 2. Create a new directory to hold your board specific code. Add any
5191 files you need. In your board directory, you will need at least
5192 the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds".
5193 3. Create a new configuration file "include/configs/<board>.h" for
5195 3. If you're porting U-Boot to a new CPU, then also create a new
5196 directory to hold your CPU specific code. Add any files you need.
5197 4. Run "make <board>_defconfig" with your new name.
5198 5. Type "make", and you should get a working "u-boot.srec" file
5199 to be installed on your target system.
5200 6. Debug and solve any problems that might arise.
5201 [Of course, this last step is much harder than it sounds.]
5204 Testing of U-Boot Modifications, Ports to New Hardware, etc.:
5205 ==============================================================
5207 If you have modified U-Boot sources (for instance added a new board
5208 or support for new devices, a new CPU, etc.) you are expected to
5209 provide feedback to the other developers. The feedback normally takes
5210 the form of a "patch", i. e. a context diff against a certain (latest
5211 official or latest in the git repository) version of U-Boot sources.
5213 But before you submit such a patch, please verify that your modifi-
5214 cation did not break existing code. At least make sure that *ALL* of
5215 the supported boards compile WITHOUT ANY compiler warnings. To do so,
5216 just run the "MAKEALL" script, which will configure and build U-Boot
5217 for ALL supported system. Be warned, this will take a while. You can
5218 select which (cross) compiler to use by passing a `CROSS_COMPILE'
5219 environment variable to the script, i. e. to use the ELDK cross tools
5222 CROSS_COMPILE=ppc_8xx- MAKEALL
5224 or to build on a native PowerPC system you can type
5226 CROSS_COMPILE=' ' MAKEALL
5228 When using the MAKEALL script, the default behaviour is to build
5229 U-Boot in the source directory. This location can be changed by
5230 setting the BUILD_DIR environment variable. Also, for each target
5231 built, the MAKEALL script saves two log files (<target>.ERR and
5232 <target>.MAKEALL) in the <source dir>/LOG directory. This default
5233 location can be changed by setting the MAKEALL_LOGDIR environment
5234 variable. For example:
5236 export BUILD_DIR=/tmp/build
5237 export MAKEALL_LOGDIR=/tmp/log
5238 CROSS_COMPILE=ppc_8xx- MAKEALL
5240 With the above settings build objects are saved in the /tmp/build,
5241 log files are saved in the /tmp/log and the source tree remains clean
5242 during the whole build process.
5245 See also "U-Boot Porting Guide" below.
5248 Monitor Commands - Overview:
5249 ============================
5251 go - start application at address 'addr'
5252 run - run commands in an environment variable
5253 bootm - boot application image from memory
5254 bootp - boot image via network using BootP/TFTP protocol
5255 bootz - boot zImage from memory
5256 tftpboot- boot image via network using TFTP protocol
5257 and env variables "ipaddr" and "serverip"
5258 (and eventually "gatewayip")
5259 tftpput - upload a file via network using TFTP protocol
5260 rarpboot- boot image via network using RARP/TFTP protocol
5261 diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
5262 loads - load S-Record file over serial line
5263 loadb - load binary file over serial line (kermit mode)
5265 mm - memory modify (auto-incrementing)
5266 nm - memory modify (constant address)
5267 mw - memory write (fill)
5269 cmp - memory compare
5270 crc32 - checksum calculation
5271 i2c - I2C sub-system
5272 sspi - SPI utility commands
5273 base - print or set address offset
5274 printenv- print environment variables
5275 setenv - set environment variables
5276 saveenv - save environment variables to persistent storage
5277 protect - enable or disable FLASH write protection
5278 erase - erase FLASH memory
5279 flinfo - print FLASH memory information
5280 nand - NAND memory operations (see doc/README.nand)
5281 bdinfo - print Board Info structure
5282 iminfo - print header information for application image
5283 coninfo - print console devices and informations
5284 ide - IDE sub-system
5285 loop - infinite loop on address range
5286 loopw - infinite write loop on address range
5287 mtest - simple RAM test
5288 icache - enable or disable instruction cache
5289 dcache - enable or disable data cache
5290 reset - Perform RESET of the CPU
5291 echo - echo args to console
5292 version - print monitor version
5293 help - print online help
5294 ? - alias for 'help'
5297 Monitor Commands - Detailed Description:
5298 ========================================
5302 For now: just type "help <command>".
5305 Environment Variables:
5306 ======================
5308 U-Boot supports user configuration using Environment Variables which
5309 can be made persistent by saving to Flash memory.
5311 Environment Variables are set using "setenv", printed using
5312 "printenv", and saved to Flash using "saveenv". Using "setenv"
5313 without a value can be used to delete a variable from the
5314 environment. As long as you don't save the environment you are
5315 working with an in-memory copy. In case the Flash area containing the
5316 environment is erased by accident, a default environment is provided.
5318 Some configuration options can be set using Environment Variables.
5320 List of environment variables (most likely not complete):
5322 baudrate - see CONFIG_BAUDRATE
5324 bootdelay - see CONFIG_BOOTDELAY
5326 bootcmd - see CONFIG_BOOTCOMMAND
5328 bootargs - Boot arguments when booting an RTOS image
5330 bootfile - Name of the image to load with TFTP
5332 bootm_low - Memory range available for image processing in the bootm
5333 command can be restricted. This variable is given as
5334 a hexadecimal number and defines lowest address allowed
5335 for use by the bootm command. See also "bootm_size"
5336 environment variable. Address defined by "bootm_low" is
5337 also the base of the initial memory mapping for the Linux
5338 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ and
5341 bootm_mapsize - Size of the initial memory mapping for the Linux kernel.
5342 This variable is given as a hexadecimal number and it
5343 defines the size of the memory region starting at base
5344 address bootm_low that is accessible by the Linux kernel
5345 during early boot. If unset, CONFIG_SYS_BOOTMAPSZ is used
5346 as the default value if it is defined, and bootm_size is
5349 bootm_size - Memory range available for image processing in the bootm
5350 command can be restricted. This variable is given as
5351 a hexadecimal number and defines the size of the region
5352 allowed for use by the bootm command. See also "bootm_low"
5353 environment variable.
5355 updatefile - Location of the software update file on a TFTP server, used
5356 by the automatic software update feature. Please refer to
5357 documentation in doc/README.update for more details.
5359 autoload - if set to "no" (any string beginning with 'n'),
5360 "bootp" will just load perform a lookup of the
5361 configuration from the BOOTP server, but not try to
5362 load any image using TFTP
5364 autostart - if set to "yes", an image loaded using the "bootp",
5365 "rarpboot", "tftpboot" or "diskboot" commands will
5366 be automatically started (by internally calling
5369 If set to "no", a standalone image passed to the
5370 "bootm" command will be copied to the load address
5371 (and eventually uncompressed), but NOT be started.
5372 This can be used to load and uncompress arbitrary
5375 fdt_high - if set this restricts the maximum address that the
5376 flattened device tree will be copied into upon boot.
5377 For example, if you have a system with 1 GB memory
5378 at physical address 0x10000000, while Linux kernel
5379 only recognizes the first 704 MB as low memory, you
5380 may need to set fdt_high as 0x3C000000 to have the
5381 device tree blob be copied to the maximum address
5382 of the 704 MB low memory, so that Linux kernel can
5383 access it during the boot procedure.
5385 If this is set to the special value 0xFFFFFFFF then
5386 the fdt will not be copied at all on boot. For this
5387 to work it must reside in writable memory, have
5388 sufficient padding on the end of it for u-boot to
5389 add the information it needs into it, and the memory
5390 must be accessible by the kernel.
5392 fdtcontroladdr- if set this is the address of the control flattened
5393 device tree used by U-Boot when CONFIG_OF_CONTROL is
5396 i2cfast - (PPC405GP|PPC405EP only)
5397 if set to 'y' configures Linux I2C driver for fast
5398 mode (400kHZ). This environment variable is used in
5399 initialization code. So, for changes to be effective
5400 it must be saved and board must be reset.
5402 initrd_high - restrict positioning of initrd images:
5403 If this variable is not set, initrd images will be
5404 copied to the highest possible address in RAM; this
5405 is usually what you want since it allows for
5406 maximum initrd size. If for some reason you want to
5407 make sure that the initrd image is loaded below the
5408 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment
5409 variable to a value of "no" or "off" or "0".
5410 Alternatively, you can set it to a maximum upper
5411 address to use (U-Boot will still check that it
5412 does not overwrite the U-Boot stack and data).
5414 For instance, when you have a system with 16 MB
5415 RAM, and want to reserve 4 MB from use by Linux,
5416 you can do this by adding "mem=12M" to the value of
5417 the "bootargs" variable. However, now you must make
5418 sure that the initrd image is placed in the first
5419 12 MB as well - this can be done with
5421 setenv initrd_high 00c00000
5423 If you set initrd_high to 0xFFFFFFFF, this is an
5424 indication to U-Boot that all addresses are legal
5425 for the Linux kernel, including addresses in flash
5426 memory. In this case U-Boot will NOT COPY the
5427 ramdisk at all. This may be useful to reduce the
5428 boot time on your system, but requires that this
5429 feature is supported by your Linux kernel.
5431 ipaddr - IP address; needed for tftpboot command
5433 loadaddr - Default load address for commands like "bootp",
5434 "rarpboot", "tftpboot", "loadb" or "diskboot"
5436 loads_echo - see CONFIG_LOADS_ECHO
5438 serverip - TFTP server IP address; needed for tftpboot command
5440 bootretry - see CONFIG_BOOT_RETRY_TIME
5442 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
5444 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
5446 ethprime - controls which interface is used first.
5448 ethact - controls which interface is currently active.
5449 For example you can do the following
5451 => setenv ethact FEC
5452 => ping 192.168.0.1 # traffic sent on FEC
5453 => setenv ethact SCC
5454 => ping 10.0.0.1 # traffic sent on SCC
5456 ethrotate - When set to "no" U-Boot does not go through all
5457 available network interfaces.
5458 It just stays at the currently selected interface.
5460 netretry - When set to "no" each network operation will
5461 either succeed or fail without retrying.
5462 When set to "once" the network operation will
5463 fail when all the available network interfaces
5464 are tried once without success.
5465 Useful on scripts which control the retry operation
5468 npe_ucode - set load address for the NPE microcode
5470 silent_linux - If set then Linux will be told to boot silently, by
5471 changing the console to be empty. If "yes" it will be
5472 made silent. If "no" it will not be made silent. If
5473 unset, then it will be made silent if the U-Boot console
5476 tftpsrcport - If this is set, the value is used for TFTP's
5479 tftpdstport - If this is set, the value is used for TFTP's UDP
5480 destination port instead of the Well Know Port 69.
5482 tftpblocksize - Block size to use for TFTP transfers; if not set,
5483 we use the TFTP server's default block size
5485 tftptimeout - Retransmission timeout for TFTP packets (in milli-
5486 seconds, minimum value is 1000 = 1 second). Defines
5487 when a packet is considered to be lost so it has to
5488 be retransmitted. The default is 5000 = 5 seconds.
5489 Lowering this value may make downloads succeed
5490 faster in networks with high packet loss rates or
5491 with unreliable TFTP servers.
5493 vlan - When set to a value < 4095 the traffic over
5494 Ethernet is encapsulated/received over 802.1q
5497 The following image location variables contain the location of images
5498 used in booting. The "Image" column gives the role of the image and is
5499 not an environment variable name. The other columns are environment
5500 variable names. "File Name" gives the name of the file on a TFTP
5501 server, "RAM Address" gives the location in RAM the image will be
5502 loaded to, and "Flash Location" gives the image's address in NOR
5503 flash or offset in NAND flash.
5505 *Note* - these variables don't have to be defined for all boards, some
5506 boards currenlty use other variables for these purposes, and some
5507 boards use these variables for other purposes.
5509 Image File Name RAM Address Flash Location
5510 ----- --------- ----------- --------------
5511 u-boot u-boot u-boot_addr_r u-boot_addr
5512 Linux kernel bootfile kernel_addr_r kernel_addr
5513 device tree blob fdtfile fdt_addr_r fdt_addr
5514 ramdisk ramdiskfile ramdisk_addr_r ramdisk_addr
5516 The following environment variables may be used and automatically
5517 updated by the network boot commands ("bootp" and "rarpboot"),
5518 depending the information provided by your boot server:
5520 bootfile - see above
5521 dnsip - IP address of your Domain Name Server
5522 dnsip2 - IP address of your secondary Domain Name Server
5523 gatewayip - IP address of the Gateway (Router) to use
5524 hostname - Target hostname
5526 netmask - Subnet Mask
5527 rootpath - Pathname of the root filesystem on the NFS server
5528 serverip - see above
5531 There are two special Environment Variables:
5533 serial# - contains hardware identification information such
5534 as type string and/or serial number
5535 ethaddr - Ethernet address
5537 These variables can be set only once (usually during manufacturing of
5538 the board). U-Boot refuses to delete or overwrite these variables
5539 once they have been set once.
5542 Further special Environment Variables:
5544 ver - Contains the U-Boot version string as printed
5545 with the "version" command. This variable is
5546 readonly (see CONFIG_VERSION_VARIABLE).
5549 Please note that changes to some configuration parameters may take
5550 only effect after the next boot (yes, that's just like Windoze :-).
5553 Callback functions for environment variables:
5554 ---------------------------------------------
5556 For some environment variables, the behavior of u-boot needs to change
5557 when their values are changed. This functionality allows functions to
5558 be associated with arbitrary variables. On creation, overwrite, or
5559 deletion, the callback will provide the opportunity for some side
5560 effect to happen or for the change to be rejected.
5562 The callbacks are named and associated with a function using the
5563 U_BOOT_ENV_CALLBACK macro in your board or driver code.
5565 These callbacks are associated with variables in one of two ways. The
5566 static list can be added to by defining CONFIG_ENV_CALLBACK_LIST_STATIC
5567 in the board configuration to a string that defines a list of
5568 associations. The list must be in the following format:
5570 entry = variable_name[:callback_name]
5573 If the callback name is not specified, then the callback is deleted.
5574 Spaces are also allowed anywhere in the list.
5576 Callbacks can also be associated by defining the ".callbacks" variable
5577 with the same list format above. Any association in ".callbacks" will
5578 override any association in the static list. You can define
5579 CONFIG_ENV_CALLBACK_LIST_DEFAULT to a list (string) to define the
5580 ".callbacks" environment variable in the default or embedded environment.
5583 Command Line Parsing:
5584 =====================
5586 There are two different command line parsers available with U-Boot:
5587 the old "simple" one, and the much more powerful "hush" shell:
5589 Old, simple command line parser:
5590 --------------------------------
5592 - supports environment variables (through setenv / saveenv commands)
5593 - several commands on one line, separated by ';'
5594 - variable substitution using "... ${name} ..." syntax
5595 - special characters ('$', ';') can be escaped by prefixing with '\',
5597 setenv bootcmd bootm \${address}
5598 - You can also escape text by enclosing in single apostrophes, for example:
5599 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
5604 - similar to Bourne shell, with control structures like
5605 if...then...else...fi, for...do...done; while...do...done,
5606 until...do...done, ...
5607 - supports environment ("global") variables (through setenv / saveenv
5608 commands) and local shell variables (through standard shell syntax
5609 "name=value"); only environment variables can be used with "run"
5615 (1) If a command line (or an environment variable executed by a "run"
5616 command) contains several commands separated by semicolon, and
5617 one of these commands fails, then the remaining commands will be
5620 (2) If you execute several variables with one call to run (i. e.
5621 calling run with a list of variables as arguments), any failing
5622 command will cause "run" to terminate, i. e. the remaining
5623 variables are not executed.
5625 Note for Redundant Ethernet Interfaces:
5626 =======================================
5628 Some boards come with redundant Ethernet interfaces; U-Boot supports
5629 such configurations and is capable of automatic selection of a
5630 "working" interface when needed. MAC assignment works as follows:
5632 Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
5633 MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
5634 "eth1addr" (=>eth1), "eth2addr", ...
5636 If the network interface stores some valid MAC address (for instance
5637 in SROM), this is used as default address if there is NO correspon-
5638 ding setting in the environment; if the corresponding environment
5639 variable is set, this overrides the settings in the card; that means:
5641 o If the SROM has a valid MAC address, and there is no address in the
5642 environment, the SROM's address is used.
5644 o If there is no valid address in the SROM, and a definition in the
5645 environment exists, then the value from the environment variable is
5648 o If both the SROM and the environment contain a MAC address, and
5649 both addresses are the same, this MAC address is used.
5651 o If both the SROM and the environment contain a MAC address, and the
5652 addresses differ, the value from the environment is used and a
5655 o If neither SROM nor the environment contain a MAC address, an error
5658 If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses
5659 will be programmed into hardware as part of the initialization process. This
5660 may be skipped by setting the appropriate 'ethmacskip' environment variable.
5661 The naming convention is as follows:
5662 "ethmacskip" (=>eth0), "eth1macskip" (=>eth1) etc.
5667 U-Boot is capable of booting (and performing other auxiliary operations on)
5668 images in two formats:
5670 New uImage format (FIT)
5671 -----------------------
5673 Flexible and powerful format based on Flattened Image Tree -- FIT (similar
5674 to Flattened Device Tree). It allows the use of images with multiple
5675 components (several kernels, ramdisks, etc.), with contents protected by
5676 SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory.
5682 Old image format is based on binary files which can be basically anything,
5683 preceded by a special header; see the definitions in include/image.h for
5684 details; basically, the header defines the following image properties:
5686 * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
5687 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
5688 LynxOS, pSOS, QNX, RTEMS, INTEGRITY;
5689 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS,
5691 * Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86,
5692 IA64, MIPS, NDS32, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
5693 Currently supported: ARM, AVR32, Intel x86, MIPS, NDS32, Nios II, PowerPC).
5694 * Compression Type (uncompressed, gzip, bzip2)
5700 The header is marked by a special Magic Number, and both the header
5701 and the data portions of the image are secured against corruption by
5708 Although U-Boot should support any OS or standalone application
5709 easily, the main focus has always been on Linux during the design of
5712 U-Boot includes many features that so far have been part of some
5713 special "boot loader" code within the Linux kernel. Also, any
5714 "initrd" images to be used are no longer part of one big Linux image;
5715 instead, kernel and "initrd" are separate images. This implementation
5716 serves several purposes:
5718 - the same features can be used for other OS or standalone
5719 applications (for instance: using compressed images to reduce the
5720 Flash memory footprint)
5722 - it becomes much easier to port new Linux kernel versions because
5723 lots of low-level, hardware dependent stuff are done by U-Boot
5725 - the same Linux kernel image can now be used with different "initrd"
5726 images; of course this also means that different kernel images can
5727 be run with the same "initrd". This makes testing easier (you don't
5728 have to build a new "zImage.initrd" Linux image when you just
5729 change a file in your "initrd"). Also, a field-upgrade of the
5730 software is easier now.
5736 Porting Linux to U-Boot based systems:
5737 ---------------------------------------
5739 U-Boot cannot save you from doing all the necessary modifications to
5740 configure the Linux device drivers for use with your target hardware
5741 (no, we don't intend to provide a full virtual machine interface to
5744 But now you can ignore ALL boot loader code (in arch/powerpc/mbxboot).
5746 Just make sure your machine specific header file (for instance
5747 include/asm-ppc/tqm8xx.h) includes the same definition of the Board
5748 Information structure as we define in include/asm-<arch>/u-boot.h,
5749 and make sure that your definition of IMAP_ADDR uses the same value
5750 as your U-Boot configuration in CONFIG_SYS_IMMR.
5752 Note that U-Boot now has a driver model, a unified model for drivers.
5753 If you are adding a new driver, plumb it into driver model. If there
5754 is no uclass available, you are encouraged to create one. See
5758 Configuring the Linux kernel:
5759 -----------------------------
5761 No specific requirements for U-Boot. Make sure you have some root
5762 device (initial ramdisk, NFS) for your target system.
5765 Building a Linux Image:
5766 -----------------------
5768 With U-Boot, "normal" build targets like "zImage" or "bzImage" are
5769 not used. If you use recent kernel source, a new build target
5770 "uImage" will exist which automatically builds an image usable by
5771 U-Boot. Most older kernels also have support for a "pImage" target,
5772 which was introduced for our predecessor project PPCBoot and uses a
5773 100% compatible format.
5777 make TQM850L_defconfig
5782 The "uImage" build target uses a special tool (in 'tools/mkimage') to
5783 encapsulate a compressed Linux kernel image with header information,
5784 CRC32 checksum etc. for use with U-Boot. This is what we are doing:
5786 * build a standard "vmlinux" kernel image (in ELF binary format):
5788 * convert the kernel into a raw binary image:
5790 ${CROSS_COMPILE}-objcopy -O binary \
5791 -R .note -R .comment \
5792 -S vmlinux linux.bin
5794 * compress the binary image:
5798 * package compressed binary image for U-Boot:
5800 mkimage -A ppc -O linux -T kernel -C gzip \
5801 -a 0 -e 0 -n "Linux Kernel Image" \
5802 -d linux.bin.gz uImage
5805 The "mkimage" tool can also be used to create ramdisk images for use
5806 with U-Boot, either separated from the Linux kernel image, or
5807 combined into one file. "mkimage" encapsulates the images with a 64
5808 byte header containing information about target architecture,
5809 operating system, image type, compression method, entry points, time
5810 stamp, CRC32 checksums, etc.
5812 "mkimage" can be called in two ways: to verify existing images and
5813 print the header information, or to build new images.
5815 In the first form (with "-l" option) mkimage lists the information
5816 contained in the header of an existing U-Boot image; this includes
5817 checksum verification:
5819 tools/mkimage -l image
5820 -l ==> list image header information
5822 The second form (with "-d" option) is used to build a U-Boot image
5823 from a "data file" which is used as image payload:
5825 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
5826 -n name -d data_file image
5827 -A ==> set architecture to 'arch'
5828 -O ==> set operating system to 'os'
5829 -T ==> set image type to 'type'
5830 -C ==> set compression type 'comp'
5831 -a ==> set load address to 'addr' (hex)
5832 -e ==> set entry point to 'ep' (hex)
5833 -n ==> set image name to 'name'
5834 -d ==> use image data from 'datafile'
5836 Right now, all Linux kernels for PowerPC systems use the same load
5837 address (0x00000000), but the entry point address depends on the
5840 - 2.2.x kernels have the entry point at 0x0000000C,
5841 - 2.3.x and later kernels have the entry point at 0x00000000.
5843 So a typical call to build a U-Boot image would read:
5845 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
5846 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
5847 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz \
5848 > examples/uImage.TQM850L
5849 Image Name: 2.4.4 kernel for TQM850L
5850 Created: Wed Jul 19 02:34:59 2000
5851 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5852 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
5853 Load Address: 0x00000000
5854 Entry Point: 0x00000000
5856 To verify the contents of the image (or check for corruption):
5858 -> tools/mkimage -l examples/uImage.TQM850L
5859 Image Name: 2.4.4 kernel for TQM850L
5860 Created: Wed Jul 19 02:34:59 2000
5861 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5862 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
5863 Load Address: 0x00000000
5864 Entry Point: 0x00000000
5866 NOTE: for embedded systems where boot time is critical you can trade
5867 speed for memory and install an UNCOMPRESSED image instead: this
5868 needs more space in Flash, but boots much faster since it does not
5869 need to be uncompressed:
5871 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz
5872 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
5873 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
5874 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux \
5875 > examples/uImage.TQM850L-uncompressed
5876 Image Name: 2.4.4 kernel for TQM850L
5877 Created: Wed Jul 19 02:34:59 2000
5878 Image Type: PowerPC Linux Kernel Image (uncompressed)
5879 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
5880 Load Address: 0x00000000
5881 Entry Point: 0x00000000
5884 Similar you can build U-Boot images from a 'ramdisk.image.gz' file
5885 when your kernel is intended to use an initial ramdisk:
5887 -> tools/mkimage -n 'Simple Ramdisk Image' \
5888 > -A ppc -O linux -T ramdisk -C gzip \
5889 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
5890 Image Name: Simple Ramdisk Image
5891 Created: Wed Jan 12 14:01:50 2000
5892 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5893 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
5894 Load Address: 0x00000000
5895 Entry Point: 0x00000000
5897 The "dumpimage" is a tool to disassemble images built by mkimage. Its "-i"
5898 option performs the converse operation of the mkimage's second form (the "-d"
5899 option). Given an image built by mkimage, the dumpimage extracts a "data file"
5902 tools/dumpimage -i image -T type -p position data_file
5903 -i ==> extract from the 'image' a specific 'data_file'
5904 -T ==> set image type to 'type'
5905 -p ==> 'position' (starting at 0) of the 'data_file' inside the 'image'
5908 Installing a Linux Image:
5909 -------------------------
5911 To downloading a U-Boot image over the serial (console) interface,
5912 you must convert the image to S-Record format:
5914 objcopy -I binary -O srec examples/image examples/image.srec
5916 The 'objcopy' does not understand the information in the U-Boot
5917 image header, so the resulting S-Record file will be relative to
5918 address 0x00000000. To load it to a given address, you need to
5919 specify the target address as 'offset' parameter with the 'loads'
5922 Example: install the image to address 0x40100000 (which on the
5923 TQM8xxL is in the first Flash bank):
5925 => erase 40100000 401FFFFF
5931 ## Ready for S-Record download ...
5932 ~>examples/image.srec
5933 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
5935 15989 15990 15991 15992
5936 [file transfer complete]
5938 ## Start Addr = 0x00000000
5941 You can check the success of the download using the 'iminfo' command;
5942 this includes a checksum verification so you can be sure no data
5943 corruption happened:
5947 ## Checking Image at 40100000 ...
5948 Image Name: 2.2.13 for initrd on TQM850L
5949 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5950 Data Size: 335725 Bytes = 327 kB = 0 MB
5951 Load Address: 00000000
5952 Entry Point: 0000000c
5953 Verifying Checksum ... OK
5959 The "bootm" command is used to boot an application that is stored in
5960 memory (RAM or Flash). In case of a Linux kernel image, the contents
5961 of the "bootargs" environment variable is passed to the kernel as
5962 parameters. You can check and modify this variable using the
5963 "printenv" and "setenv" commands:
5966 => printenv bootargs
5967 bootargs=root=/dev/ram
5969 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5971 => printenv bootargs
5972 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5975 ## Booting Linux kernel at 40020000 ...
5976 Image Name: 2.2.13 for NFS on TQM850L
5977 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5978 Data Size: 381681 Bytes = 372 kB = 0 MB
5979 Load Address: 00000000
5980 Entry Point: 0000000c
5981 Verifying Checksum ... OK
5982 Uncompressing Kernel Image ... OK
5983 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
5984 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5985 time_init: decrementer frequency = 187500000/60
5986 Calibrating delay loop... 49.77 BogoMIPS
5987 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
5990 If you want to boot a Linux kernel with initial RAM disk, you pass
5991 the memory addresses of both the kernel and the initrd image (PPBCOOT
5992 format!) to the "bootm" command:
5994 => imi 40100000 40200000
5996 ## Checking Image at 40100000 ...
5997 Image Name: 2.2.13 for initrd on TQM850L
5998 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5999 Data Size: 335725 Bytes = 327 kB = 0 MB
6000 Load Address: 00000000
6001 Entry Point: 0000000c
6002 Verifying Checksum ... OK
6004 ## Checking Image at 40200000 ...
6005 Image Name: Simple Ramdisk Image
6006 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
6007 Data Size: 566530 Bytes = 553 kB = 0 MB
6008 Load Address: 00000000
6009 Entry Point: 00000000
6010 Verifying Checksum ... OK
6012 => bootm 40100000 40200000
6013 ## Booting Linux kernel at 40100000 ...
6014 Image Name: 2.2.13 for initrd on TQM850L
6015 Image Type: PowerPC Linux Kernel Image (gzip compressed)
6016 Data Size: 335725 Bytes = 327 kB = 0 MB
6017 Load Address: 00000000
6018 Entry Point: 0000000c
6019 Verifying Checksum ... OK
6020 Uncompressing Kernel Image ... OK
6021 ## Loading RAMDisk Image at 40200000 ...
6022 Image Name: Simple Ramdisk Image
6023 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
6024 Data Size: 566530 Bytes = 553 kB = 0 MB
6025 Load Address: 00000000
6026 Entry Point: 00000000
6027 Verifying Checksum ... OK
6028 Loading Ramdisk ... OK
6029 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
6030 Boot arguments: root=/dev/ram
6031 time_init: decrementer frequency = 187500000/60
6032 Calibrating delay loop... 49.77 BogoMIPS
6034 RAMDISK: Compressed image found at block 0
6035 VFS: Mounted root (ext2 filesystem).
6039 Boot Linux and pass a flat device tree:
6042 First, U-Boot must be compiled with the appropriate defines. See the section
6043 titled "Linux Kernel Interface" above for a more in depth explanation. The
6044 following is an example of how to start a kernel and pass an updated
6050 oft=oftrees/mpc8540ads.dtb
6051 => tftp $oftaddr $oft
6052 Speed: 1000, full duplex
6054 TFTP from server 192.168.1.1; our IP address is 192.168.1.101
6055 Filename 'oftrees/mpc8540ads.dtb'.
6056 Load address: 0x300000
6059 Bytes transferred = 4106 (100a hex)
6060 => tftp $loadaddr $bootfile
6061 Speed: 1000, full duplex
6063 TFTP from server 192.168.1.1; our IP address is 192.168.1.2
6065 Load address: 0x200000
6066 Loading:############
6068 Bytes transferred = 1029407 (fb51f hex)
6073 => bootm $loadaddr - $oftaddr
6074 ## Booting image at 00200000 ...
6075 Image Name: Linux-2.6.17-dirty
6076 Image Type: PowerPC Linux Kernel Image (gzip compressed)
6077 Data Size: 1029343 Bytes = 1005.2 kB
6078 Load Address: 00000000
6079 Entry Point: 00000000
6080 Verifying Checksum ... OK
6081 Uncompressing Kernel Image ... OK
6082 Booting using flat device tree at 0x300000
6083 Using MPC85xx ADS machine description
6084 Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb
6088 More About U-Boot Image Types:
6089 ------------------------------
6091 U-Boot supports the following image types:
6093 "Standalone Programs" are directly runnable in the environment
6094 provided by U-Boot; it is expected that (if they behave
6095 well) you can continue to work in U-Boot after return from
6096 the Standalone Program.
6097 "OS Kernel Images" are usually images of some Embedded OS which
6098 will take over control completely. Usually these programs
6099 will install their own set of exception handlers, device
6100 drivers, set up the MMU, etc. - this means, that you cannot
6101 expect to re-enter U-Boot except by resetting the CPU.
6102 "RAMDisk Images" are more or less just data blocks, and their
6103 parameters (address, size) are passed to an OS kernel that is
6105 "Multi-File Images" contain several images, typically an OS
6106 (Linux) kernel image and one or more data images like
6107 RAMDisks. This construct is useful for instance when you want
6108 to boot over the network using BOOTP etc., where the boot
6109 server provides just a single image file, but you want to get
6110 for instance an OS kernel and a RAMDisk image.
6112 "Multi-File Images" start with a list of image sizes, each
6113 image size (in bytes) specified by an "uint32_t" in network
6114 byte order. This list is terminated by an "(uint32_t)0".
6115 Immediately after the terminating 0 follow the images, one by
6116 one, all aligned on "uint32_t" boundaries (size rounded up to
6117 a multiple of 4 bytes).
6119 "Firmware Images" are binary images containing firmware (like
6120 U-Boot or FPGA images) which usually will be programmed to
6123 "Script files" are command sequences that will be executed by
6124 U-Boot's command interpreter; this feature is especially
6125 useful when you configure U-Boot to use a real shell (hush)
6126 as command interpreter.
6128 Booting the Linux zImage:
6129 -------------------------
6131 On some platforms, it's possible to boot Linux zImage. This is done
6132 using the "bootz" command. The syntax of "bootz" command is the same
6133 as the syntax of "bootm" command.
6135 Note, defining the CONFIG_SUPPORT_RAW_INITRD allows user to supply
6136 kernel with raw initrd images. The syntax is slightly different, the
6137 address of the initrd must be augmented by it's size, in the following
6138 format: "<initrd addres>:<initrd size>".
6144 One of the features of U-Boot is that you can dynamically load and
6145 run "standalone" applications, which can use some resources of
6146 U-Boot like console I/O functions or interrupt services.
6148 Two simple examples are included with the sources:
6153 'examples/hello_world.c' contains a small "Hello World" Demo
6154 application; it is automatically compiled when you build U-Boot.
6155 It's configured to run at address 0x00040004, so you can play with it
6159 ## Ready for S-Record download ...
6160 ~>examples/hello_world.srec
6161 1 2 3 4 5 6 7 8 9 10 11 ...
6162 [file transfer complete]
6164 ## Start Addr = 0x00040004
6166 => go 40004 Hello World! This is a test.
6167 ## Starting application at 0x00040004 ...
6178 Hit any key to exit ...
6180 ## Application terminated, rc = 0x0
6182 Another example, which demonstrates how to register a CPM interrupt
6183 handler with the U-Boot code, can be found in 'examples/timer.c'.
6184 Here, a CPM timer is set up to generate an interrupt every second.
6185 The interrupt service routine is trivial, just printing a '.'
6186 character, but this is just a demo program. The application can be
6187 controlled by the following keys:
6189 ? - print current values og the CPM Timer registers
6190 b - enable interrupts and start timer
6191 e - stop timer and disable interrupts
6192 q - quit application
6195 ## Ready for S-Record download ...
6196 ~>examples/timer.srec
6197 1 2 3 4 5 6 7 8 9 10 11 ...
6198 [file transfer complete]
6200 ## Start Addr = 0x00040004
6203 ## Starting application at 0x00040004 ...
6206 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
6209 [q, b, e, ?] Set interval 1000000 us
6212 [q, b, e, ?] ........
6213 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
6216 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
6219 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
6222 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
6224 [q, b, e, ?] ...Stopping timer
6226 [q, b, e, ?] ## Application terminated, rc = 0x0
6232 Over time, many people have reported problems when trying to use the
6233 "minicom" terminal emulation program for serial download. I (wd)
6234 consider minicom to be broken, and recommend not to use it. Under
6235 Unix, I recommend to use C-Kermit for general purpose use (and
6236 especially for kermit binary protocol download ("loadb" command), and
6237 use "cu" for S-Record download ("loads" command). See
6238 http://www.denx.de/wiki/view/DULG/SystemSetup#Section_4.3.
6239 for help with kermit.
6242 Nevertheless, if you absolutely want to use it try adding this
6243 configuration to your "File transfer protocols" section:
6245 Name Program Name U/D FullScr IO-Red. Multi
6246 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
6247 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
6253 Starting at version 0.9.2, U-Boot supports NetBSD both as host
6254 (build U-Boot) and target system (boots NetBSD/mpc8xx).
6256 Building requires a cross environment; it is known to work on
6257 NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
6258 need gmake since the Makefiles are not compatible with BSD make).
6259 Note that the cross-powerpc package does not install include files;
6260 attempting to build U-Boot will fail because <machine/ansi.h> is
6261 missing. This file has to be installed and patched manually:
6263 # cd /usr/pkg/cross/powerpc-netbsd/include
6265 # ln -s powerpc machine
6266 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
6267 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
6269 Native builds *don't* work due to incompatibilities between native
6270 and U-Boot include files.
6272 Booting assumes that (the first part of) the image booted is a
6273 stage-2 loader which in turn loads and then invokes the kernel
6274 proper. Loader sources will eventually appear in the NetBSD source
6275 tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
6276 meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz
6279 Implementation Internals:
6280 =========================
6282 The following is not intended to be a complete description of every
6283 implementation detail. However, it should help to understand the
6284 inner workings of U-Boot and make it easier to port it to custom
6288 Initial Stack, Global Data:
6289 ---------------------------
6291 The implementation of U-Boot is complicated by the fact that U-Boot
6292 starts running out of ROM (flash memory), usually without access to
6293 system RAM (because the memory controller is not initialized yet).
6294 This means that we don't have writable Data or BSS segments, and BSS
6295 is not initialized as zero. To be able to get a C environment working
6296 at all, we have to allocate at least a minimal stack. Implementation
6297 options for this are defined and restricted by the CPU used: Some CPU
6298 models provide on-chip memory (like the IMMR area on MPC8xx and
6299 MPC826x processors), on others (parts of) the data cache can be
6300 locked as (mis-) used as memory, etc.
6302 Chris Hallinan posted a good summary of these issues to the
6303 U-Boot mailing list:
6305 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
6306 From: "Chris Hallinan" <clh@net1plus.com>
6307 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
6310 Correct me if I'm wrong, folks, but the way I understand it
6311 is this: Using DCACHE as initial RAM for Stack, etc, does not
6312 require any physical RAM backing up the cache. The cleverness
6313 is that the cache is being used as a temporary supply of
6314 necessary storage before the SDRAM controller is setup. It's
6315 beyond the scope of this list to explain the details, but you
6316 can see how this works by studying the cache architecture and
6317 operation in the architecture and processor-specific manuals.
6319 OCM is On Chip Memory, which I believe the 405GP has 4K. It
6320 is another option for the system designer to use as an
6321 initial stack/RAM area prior to SDRAM being available. Either
6322 option should work for you. Using CS 4 should be fine if your
6323 board designers haven't used it for something that would
6324 cause you grief during the initial boot! It is frequently not
6327 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere
6328 with your processor/board/system design. The default value
6329 you will find in any recent u-boot distribution in
6330 walnut.h should work for you. I'd set it to a value larger
6331 than your SDRAM module. If you have a 64MB SDRAM module, set
6332 it above 400_0000. Just make sure your board has no resources
6333 that are supposed to respond to that address! That code in
6334 start.S has been around a while and should work as is when
6335 you get the config right.
6340 It is essential to remember this, since it has some impact on the C
6341 code for the initialization procedures:
6343 * Initialized global data (data segment) is read-only. Do not attempt
6346 * Do not use any uninitialized global data (or implicitly initialized
6347 as zero data - BSS segment) at all - this is undefined, initiali-
6348 zation is performed later (when relocating to RAM).
6350 * Stack space is very limited. Avoid big data buffers or things like
6353 Having only the stack as writable memory limits means we cannot use
6354 normal global data to share information between the code. But it
6355 turned out that the implementation of U-Boot can be greatly
6356 simplified by making a global data structure (gd_t) available to all
6357 functions. We could pass a pointer to this data as argument to _all_
6358 functions, but this would bloat the code. Instead we use a feature of
6359 the GCC compiler (Global Register Variables) to share the data: we
6360 place a pointer (gd) to the global data into a register which we
6361 reserve for this purpose.
6363 When choosing a register for such a purpose we are restricted by the
6364 relevant (E)ABI specifications for the current architecture, and by
6365 GCC's implementation.
6367 For PowerPC, the following registers have specific use:
6369 R2: reserved for system use
6370 R3-R4: parameter passing and return values
6371 R5-R10: parameter passing
6372 R13: small data area pointer
6376 (U-Boot also uses R12 as internal GOT pointer. r12
6377 is a volatile register so r12 needs to be reset when
6378 going back and forth between asm and C)
6380 ==> U-Boot will use R2 to hold a pointer to the global data
6382 Note: on PPC, we could use a static initializer (since the
6383 address of the global data structure is known at compile time),
6384 but it turned out that reserving a register results in somewhat
6385 smaller code - although the code savings are not that big (on
6386 average for all boards 752 bytes for the whole U-Boot image,
6387 624 text + 127 data).
6389 On Blackfin, the normal C ABI (except for P3) is followed as documented here:
6390 http://docs.blackfin.uclinux.org/doku.php?id=application_binary_interface
6392 ==> U-Boot will use P3 to hold a pointer to the global data
6394 On ARM, the following registers are used:
6396 R0: function argument word/integer result
6397 R1-R3: function argument word
6398 R9: platform specific
6399 R10: stack limit (used only if stack checking is enabled)
6400 R11: argument (frame) pointer
6401 R12: temporary workspace
6404 R15: program counter
6406 ==> U-Boot will use R9 to hold a pointer to the global data
6408 Note: on ARM, only R_ARM_RELATIVE relocations are supported.
6410 On Nios II, the ABI is documented here:
6411 http://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf
6413 ==> U-Boot will use gp to hold a pointer to the global data
6415 Note: on Nios II, we give "-G0" option to gcc and don't use gp
6416 to access small data sections, so gp is free.
6418 On NDS32, the following registers are used:
6420 R0-R1: argument/return
6422 R15: temporary register for assembler
6423 R16: trampoline register
6424 R28: frame pointer (FP)
6425 R29: global pointer (GP)
6426 R30: link register (LP)
6427 R31: stack pointer (SP)
6428 PC: program counter (PC)
6430 ==> U-Boot will use R10 to hold a pointer to the global data
6432 NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope,
6433 or current versions of GCC may "optimize" the code too much.
6438 U-Boot runs in system state and uses physical addresses, i.e. the
6439 MMU is not used either for address mapping nor for memory protection.
6441 The available memory is mapped to fixed addresses using the memory
6442 controller. In this process, a contiguous block is formed for each
6443 memory type (Flash, SDRAM, SRAM), even when it consists of several
6444 physical memory banks.
6446 U-Boot is installed in the first 128 kB of the first Flash bank (on
6447 TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
6448 booting and sizing and initializing DRAM, the code relocates itself
6449 to the upper end of DRAM. Immediately below the U-Boot code some
6450 memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN
6451 configuration setting]. Below that, a structure with global Board
6452 Info data is placed, followed by the stack (growing downward).
6454 Additionally, some exception handler code is copied to the low 8 kB
6455 of DRAM (0x00000000 ... 0x00001FFF).
6457 So a typical memory configuration with 16 MB of DRAM could look like
6460 0x0000 0000 Exception Vector code
6463 0x0000 2000 Free for Application Use
6469 0x00FB FF20 Monitor Stack (Growing downward)
6470 0x00FB FFAC Board Info Data and permanent copy of global data
6471 0x00FC 0000 Malloc Arena
6474 0x00FE 0000 RAM Copy of Monitor Code
6475 ... eventually: LCD or video framebuffer
6476 ... eventually: pRAM (Protected RAM - unchanged by reset)
6477 0x00FF FFFF [End of RAM]
6480 System Initialization:
6481 ----------------------
6483 In the reset configuration, U-Boot starts at the reset entry point
6484 (on most PowerPC systems at address 0x00000100). Because of the reset
6485 configuration for CS0# this is a mirror of the on board Flash memory.
6486 To be able to re-map memory U-Boot then jumps to its link address.
6487 To be able to implement the initialization code in C, a (small!)
6488 initial stack is set up in the internal Dual Ported RAM (in case CPUs
6489 which provide such a feature like MPC8xx or MPC8260), or in a locked
6490 part of the data cache. After that, U-Boot initializes the CPU core,
6491 the caches and the SIU.
6493 Next, all (potentially) available memory banks are mapped using a
6494 preliminary mapping. For example, we put them on 512 MB boundaries
6495 (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
6496 on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
6497 programmed for SDRAM access. Using the temporary configuration, a
6498 simple memory test is run that determines the size of the SDRAM
6501 When there is more than one SDRAM bank, and the banks are of
6502 different size, the largest is mapped first. For equal size, the first
6503 bank (CS2#) is mapped first. The first mapping is always for address
6504 0x00000000, with any additional banks following immediately to create
6505 contiguous memory starting from 0.
6507 Then, the monitor installs itself at the upper end of the SDRAM area
6508 and allocates memory for use by malloc() and for the global Board
6509 Info data; also, the exception vector code is copied to the low RAM
6510 pages, and the final stack is set up.
6512 Only after this relocation will you have a "normal" C environment;
6513 until that you are restricted in several ways, mostly because you are
6514 running from ROM, and because the code will have to be relocated to a
6518 U-Boot Porting Guide:
6519 ----------------------
6521 [Based on messages by Jerry Van Baren in the U-Boot-Users mailing
6525 int main(int argc, char *argv[])
6527 sighandler_t no_more_time;
6529 signal(SIGALRM, no_more_time);
6530 alarm(PROJECT_DEADLINE - toSec (3 * WEEK));
6532 if (available_money > available_manpower) {
6533 Pay consultant to port U-Boot;
6537 Download latest U-Boot source;
6539 Subscribe to u-boot mailing list;
6542 email("Hi, I am new to U-Boot, how do I get started?");
6545 Read the README file in the top level directory;
6546 Read http://www.denx.de/twiki/bin/view/DULG/Manual;
6547 Read applicable doc/*.README;
6548 Read the source, Luke;
6549 /* find . -name "*.[chS]" | xargs grep -i <keyword> */
6552 if (available_money > toLocalCurrency ($2500))
6555 Add a lot of aggravation and time;
6557 if (a similar board exists) { /* hopefully... */
6558 cp -a board/<similar> board/<myboard>
6559 cp include/configs/<similar>.h include/configs/<myboard>.h
6561 Create your own board support subdirectory;
6562 Create your own board include/configs/<myboard>.h file;
6564 Edit new board/<myboard> files
6565 Edit new include/configs/<myboard>.h
6570 Add / modify source code;
6574 email("Hi, I am having problems...");
6576 Send patch file to the U-Boot email list;
6577 if (reasonable critiques)
6578 Incorporate improvements from email list code review;
6580 Defend code as written;
6586 void no_more_time (int sig)
6595 All contributions to U-Boot should conform to the Linux kernel
6596 coding style; see the file "Documentation/CodingStyle" and the script
6597 "scripts/Lindent" in your Linux kernel source directory.
6599 Source files originating from a different project (for example the
6600 MTD subsystem) are generally exempt from these guidelines and are not
6601 reformatted to ease subsequent migration to newer versions of those
6604 Please note that U-Boot is implemented in C (and to some small parts in
6605 Assembler); no C++ is used, so please do not use C++ style comments (//)
6608 Please also stick to the following formatting rules:
6609 - remove any trailing white space
6610 - use TAB characters for indentation and vertical alignment, not spaces
6611 - make sure NOT to use DOS '\r\n' line feeds
6612 - do not add more than 2 consecutive empty lines to source files
6613 - do not add trailing empty lines to source files
6615 Submissions which do not conform to the standards may be returned
6616 with a request to reformat the changes.
6622 Since the number of patches for U-Boot is growing, we need to
6623 establish some rules. Submissions which do not conform to these rules
6624 may be rejected, even when they contain important and valuable stuff.
6626 Please see http://www.denx.de/wiki/U-Boot/Patches for details.
6628 Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>;
6629 see http://lists.denx.de/mailman/listinfo/u-boot
6631 When you send a patch, please include the following information with
6634 * For bug fixes: a description of the bug and how your patch fixes
6635 this bug. Please try to include a way of demonstrating that the
6636 patch actually fixes something.
6638 * For new features: a description of the feature and your
6641 * A CHANGELOG entry as plaintext (separate from the patch)
6643 * For major contributions, your entry to the CREDITS file
6645 * When you add support for a new board, don't forget to add a
6646 maintainer e-mail address to the boards.cfg file, too.
6648 * If your patch adds new configuration options, don't forget to
6649 document these in the README file.
6651 * The patch itself. If you are using git (which is *strongly*
6652 recommended) you can easily generate the patch using the
6653 "git format-patch". If you then use "git send-email" to send it to
6654 the U-Boot mailing list, you will avoid most of the common problems
6655 with some other mail clients.
6657 If you cannot use git, use "diff -purN OLD NEW". If your version of
6658 diff does not support these options, then get the latest version of
6661 The current directory when running this command shall be the parent
6662 directory of the U-Boot source tree (i. e. please make sure that
6663 your patch includes sufficient directory information for the
6666 We prefer patches as plain text. MIME attachments are discouraged,
6667 and compressed attachments must not be used.
6669 * If one logical set of modifications affects or creates several
6670 files, all these changes shall be submitted in a SINGLE patch file.
6672 * Changesets that contain different, unrelated modifications shall be
6673 submitted as SEPARATE patches, one patch per changeset.
6678 * Before sending the patch, run the MAKEALL script on your patched
6679 source tree and make sure that no errors or warnings are reported
6680 for any of the boards.
6682 * Keep your modifications to the necessary minimum: A patch
6683 containing several unrelated changes or arbitrary reformats will be
6684 returned with a request to re-formatting / split it.
6686 * If you modify existing code, make sure that your new code does not
6687 add to the memory footprint of the code ;-) Small is beautiful!
6688 When adding new features, these should compile conditionally only
6689 (using #ifdef), and the resulting code with the new feature
6690 disabled must not need more memory than the old code without your
6693 * Remember that there is a size limit of 100 kB per message on the
6694 u-boot mailing list. Bigger patches will be moderated. If they are
6695 reasonable and not too big, they will be acknowledged. But patches
6696 bigger than the size limit should be avoided.
projects / karo-tx-uboot.git / blob