2 # (C) Copyright 2000 - 2013
3 # Wolfgang Denk, DENX Software Engineering, wd@denx.de.
5 # SPDX-License-Identifier: GPL-2.0+
11 This directory contains the source code for U-Boot, a boot loader for
12 Embedded boards based on PowerPC, ARM, MIPS and several other
13 processors, which can be installed in a boot ROM and used to
14 initialize and test the hardware or to download and run application
17 The development of U-Boot is closely related to Linux: some parts of
18 the source code originate in the Linux source tree, we have some
19 header files in common, and special provision has been made to
20 support booting of Linux images.
22 Some attention has been paid to make this software easily
23 configurable and extendable. For instance, all monitor commands are
24 implemented with the same call interface, so that it's very easy to
25 add new commands. Also, instead of permanently adding rarely used
26 code (for instance hardware test utilities) to the monitor, you can
27 load and run it dynamically.
33 In general, all boards for which a configuration option exists in the
34 Makefile have been tested to some extent and can be considered
35 "working". In fact, many of them are used in production systems.
37 In case of problems see the CHANGELOG and CREDITS files to find out
38 who contributed the specific port. The boards.cfg file lists board
41 Note: There is no CHANGELOG file in the actual U-Boot source tree;
42 it can be created dynamically from the Git log using:
50 In case you have questions about, problems with or contributions for
51 U-Boot you should send a message to the U-Boot mailing list at
52 <u-boot@lists.denx.de>. There is also an archive of previous traffic
53 on the mailing list - please search the archive before asking FAQ's.
54 Please see http://lists.denx.de/pipermail/u-boot and
55 http://dir.gmane.org/gmane.comp.boot-loaders.u-boot
58 Where to get source code:
59 =========================
61 The U-Boot source code is maintained in the git repository at
62 git://www.denx.de/git/u-boot.git ; you can browse it online at
63 http://www.denx.de/cgi-bin/gitweb.cgi?p=u-boot.git;a=summary
65 The "snapshot" links on this page allow you to download tarballs of
66 any version you might be interested in. Official releases are also
67 available for FTP download from the ftp://ftp.denx.de/pub/u-boot/
70 Pre-built (and tested) images are available from
71 ftp://ftp.denx.de/pub/u-boot/images/
77 - start from 8xxrom sources
78 - create PPCBoot project (http://sourceforge.net/projects/ppcboot)
80 - make it easier to add custom boards
81 - make it possible to add other [PowerPC] CPUs
82 - extend functions, especially:
83 * Provide extended interface to Linux boot loader
86 * PCMCIA / CompactFlash / ATA disk / SCSI ... boot
87 - create ARMBoot project (http://sourceforge.net/projects/armboot)
88 - add other CPU families (starting with ARM)
89 - create U-Boot project (http://sourceforge.net/projects/u-boot)
90 - current project page: see http://www.denx.de/wiki/U-Boot
96 The "official" name of this project is "Das U-Boot". The spelling
97 "U-Boot" shall be used in all written text (documentation, comments
98 in source files etc.). Example:
100 This is the README file for the U-Boot project.
102 File names etc. shall be based on the string "u-boot". Examples:
104 include/asm-ppc/u-boot.h
106 #include <asm/u-boot.h>
108 Variable names, preprocessor constants etc. shall be either based on
109 the string "u_boot" or on "U_BOOT". Example:
111 U_BOOT_VERSION u_boot_logo
112 IH_OS_U_BOOT u_boot_hush_start
118 Starting with the release in October 2008, the names of the releases
119 were changed from numerical release numbers without deeper meaning
120 into a time stamp based numbering. Regular releases are identified by
121 names consisting of the calendar year and month of the release date.
122 Additional fields (if present) indicate release candidates or bug fix
123 releases in "stable" maintenance trees.
126 U-Boot v2009.11 - Release November 2009
127 U-Boot v2009.11.1 - Release 1 in version November 2009 stable tree
128 U-Boot v2010.09-rc1 - Release candiate 1 for September 2010 release
134 /arch Architecture specific files
135 /arc Files generic to ARC architecture
136 /cpu CPU specific files
137 /arc700 Files specific to ARC 700 CPUs
138 /lib Architecture specific library files
139 /arm Files generic to ARM architecture
140 /cpu CPU specific files
141 /arm720t Files specific to ARM 720 CPUs
142 /arm920t Files specific to ARM 920 CPUs
143 /at91 Files specific to Atmel AT91RM9200 CPU
144 /imx Files specific to Freescale MC9328 i.MX CPUs
145 /s3c24x0 Files specific to Samsung S3C24X0 CPUs
146 /arm926ejs Files specific to ARM 926 CPUs
147 /arm1136 Files specific to ARM 1136 CPUs
148 /pxa Files specific to Intel XScale PXA CPUs
149 /sa1100 Files specific to Intel StrongARM SA1100 CPUs
150 /lib Architecture specific library files
151 /avr32 Files generic to AVR32 architecture
152 /cpu CPU specific files
153 /lib Architecture specific library files
154 /blackfin Files generic to Analog Devices Blackfin architecture
155 /cpu CPU specific files
156 /lib Architecture specific library files
157 /m68k Files generic to m68k architecture
158 /cpu CPU specific files
159 /mcf52x2 Files specific to Freescale ColdFire MCF52x2 CPUs
160 /mcf5227x Files specific to Freescale ColdFire MCF5227x CPUs
161 /mcf532x Files specific to Freescale ColdFire MCF5329 CPUs
162 /mcf5445x Files specific to Freescale ColdFire MCF5445x CPUs
163 /mcf547x_8x Files specific to Freescale ColdFire MCF547x_8x CPUs
164 /lib Architecture specific library files
165 /microblaze Files generic to microblaze architecture
166 /cpu CPU specific files
167 /lib Architecture specific library files
168 /mips Files generic to MIPS architecture
169 /cpu CPU specific files
170 /mips32 Files specific to MIPS32 CPUs
171 /mips64 Files specific to MIPS64 CPUs
172 /lib Architecture specific library files
173 /nds32 Files generic to NDS32 architecture
174 /cpu CPU specific files
175 /n1213 Files specific to Andes Technology N1213 CPUs
176 /lib Architecture specific library files
177 /nios2 Files generic to Altera NIOS2 architecture
178 /cpu CPU specific files
179 /lib Architecture specific library files
180 /openrisc Files generic to OpenRISC architecture
181 /cpu CPU specific files
182 /lib Architecture specific library files
183 /powerpc Files generic to PowerPC architecture
184 /cpu CPU specific files
185 /mpc5xx Files specific to Freescale MPC5xx CPUs
186 /mpc5xxx Files specific to Freescale MPC5xxx CPUs
187 /mpc8xx Files specific to Freescale MPC8xx CPUs
188 /mpc8260 Files specific to Freescale MPC8260 CPUs
189 /mpc85xx Files specific to Freescale MPC85xx CPUs
190 /ppc4xx Files specific to AMCC PowerPC 4xx CPUs
191 /lib Architecture specific library files
192 /sh Files generic to SH architecture
193 /cpu CPU specific files
194 /sh2 Files specific to sh2 CPUs
195 /sh3 Files specific to sh3 CPUs
196 /sh4 Files specific to sh4 CPUs
197 /lib Architecture specific library files
198 /sparc Files generic to SPARC architecture
199 /cpu CPU specific files
200 /leon2 Files specific to Gaisler LEON2 SPARC CPU
201 /leon3 Files specific to Gaisler LEON3 SPARC CPU
202 /lib Architecture specific library files
203 /x86 Files generic to x86 architecture
204 /cpu CPU specific files
205 /lib Architecture specific library files
206 /api Machine/arch independent API for external apps
207 /board Board dependent files
208 /common Misc architecture independent functions
209 /disk Code for disk drive partition handling
210 /doc Documentation (don't expect too much)
211 /drivers Commonly used device drivers
212 /dts Contains Makefile for building internal U-Boot fdt.
213 /examples Example code for standalone applications, etc.
214 /fs Filesystem code (cramfs, ext2, jffs2, etc.)
215 /include Header Files
216 /lib Files generic to all architectures
217 /libfdt Library files to support flattened device trees
218 /lzma Library files to support LZMA decompression
219 /lzo Library files to support LZO decompression
221 /post Power On Self Test
222 /spl Secondary Program Loader framework
223 /tools Tools to build S-Record or U-Boot images, etc.
225 Software Configuration:
226 =======================
228 Configuration is usually done using C preprocessor defines; the
229 rationale behind that is to avoid dead code whenever possible.
231 There are two classes of configuration variables:
233 * Configuration _OPTIONS_:
234 These are selectable by the user and have names beginning with
237 * Configuration _SETTINGS_:
238 These depend on the hardware etc. and should not be meddled with if
239 you don't know what you're doing; they have names beginning with
242 Later we will add a configuration tool - probably similar to or even
243 identical to what's used for the Linux kernel. Right now, we have to
244 do the configuration by hand, which means creating some symbolic
245 links and editing some configuration files. We use the TQM8xxL boards
249 Selection of Processor Architecture and Board Type:
250 ---------------------------------------------------
252 For all supported boards there are ready-to-use default
253 configurations available; just type "make <board_name>_defconfig".
255 Example: For a TQM823L module type:
258 make TQM823L_defconfig
260 For the Cogent platform, you need to specify the CPU type as well;
261 e.g. "make cogent_mpc8xx_defconfig". And also configure the cogent
262 directory according to the instructions in cogent/README.
268 U-Boot can be built natively to run on a Linux host using the 'sandbox'
269 board. This allows feature development which is not board- or architecture-
270 specific to be undertaken on a native platform. The sandbox is also used to
271 run some of U-Boot's tests.
273 See board/sandbox/README.sandbox for more details.
276 Board Initialisation Flow:
277 --------------------------
279 This is the intended start-up flow for boards. This should apply for both
280 SPL and U-Boot proper (i.e. they both follow the same rules). At present SPL
281 mostly uses a separate code path, but the funtion names and roles of each
282 function are the same. Some boards or architectures may not conform to this.
283 At least most ARM boards which use CONFIG_SPL_FRAMEWORK conform to this.
285 Execution starts with start.S with three functions called during init after
286 that. The purpose and limitations of each is described below.
289 - purpose: essential init to permit execution to reach board_init_f()
290 - no global_data or BSS
291 - there is no stack (ARMv7 may have one but it will soon be removed)
292 - must not set up SDRAM or use console
293 - must only do the bare minimum to allow execution to continue to
295 - this is almost never needed
296 - return normally from this function
299 - purpose: set up the machine ready for running board_init_r():
300 i.e. SDRAM and serial UART
301 - global_data is available
303 - BSS is not available, so you cannot use global/static variables,
304 only stack variables and global_data
306 Non-SPL-specific notes:
307 - dram_init() is called to set up DRAM. If already done in SPL this
311 - you can override the entire board_init_f() function with your own
313 - preloader_console_init() can be called here in extremis
314 - should set up SDRAM, and anything needed to make the UART work
315 - these is no need to clear BSS, it will be done by crt0.S
316 - must return normally from this function (don't call board_init_r()
319 Here the BSS is cleared. For SPL, if CONFIG_SPL_STACK_R is defined, then at
320 this point the stack and global_data are relocated to below
321 CONFIG_SPL_STACK_R_ADDR. For non-SPL, U-Boot is relocated to run at the top of
325 - purpose: main execution, common code
326 - global_data is available
328 - BSS is available, all static/global variables can be used
329 - execution eventually continues to main_loop()
331 Non-SPL-specific notes:
332 - U-Boot is relocated to the top of memory and is now running from
336 - stack is optionally in SDRAM, if CONFIG_SPL_STACK_R is defined and
337 CONFIG_SPL_STACK_R_ADDR points into SDRAM
338 - preloader_console_init() can be called here - typically this is
339 done by defining CONFIG_SPL_BOARD_INIT and then supplying a
340 spl_board_init() function containing this call
341 - loads U-Boot or (in falcon mode) Linux
345 Configuration Options:
346 ----------------------
348 Configuration depends on the combination of board and CPU type; all
349 such information is kept in a configuration file
350 "include/configs/<board_name>.h".
352 Example: For a TQM823L module, all configuration settings are in
353 "include/configs/TQM823L.h".
356 Many of the options are named exactly as the corresponding Linux
357 kernel configuration options. The intention is to make it easier to
358 build a config tool - later.
361 The following options need to be configured:
363 - CPU Type: Define exactly one, e.g. CONFIG_MPC85XX.
365 - Board Type: Define exactly one, e.g. CONFIG_MPC8540ADS.
367 - CPU Daughterboard Type: (if CONFIG_ATSTK1000 is defined)
368 Define exactly one, e.g. CONFIG_ATSTK1002
370 - CPU Module Type: (if CONFIG_COGENT is defined)
371 Define exactly one of
373 --- FIXME --- not tested yet:
374 CONFIG_CMA286_60, CONFIG_CMA286_21, CONFIG_CMA286_60P,
375 CONFIG_CMA287_23, CONFIG_CMA287_50
377 - Motherboard Type: (if CONFIG_COGENT is defined)
378 Define exactly one of
379 CONFIG_CMA101, CONFIG_CMA102
381 - Motherboard I/O Modules: (if CONFIG_COGENT is defined)
382 Define one or more of
385 - Motherboard Options: (if CONFIG_CMA101 or CONFIG_CMA102 are defined)
386 Define one or more of
387 CONFIG_LCD_HEARTBEAT - update a character position on
388 the LCD display every second with
391 - Marvell Family Member
392 CONFIG_SYS_MVFS - define it if you want to enable
393 multiple fs option at one time
394 for marvell soc family
396 - 8xx CPU Options: (if using an MPC8xx CPU)
397 CONFIG_8xx_GCLK_FREQ - deprecated: CPU clock if
398 get_gclk_freq() cannot work
399 e.g. if there is no 32KHz
400 reference PIT/RTC clock
401 CONFIG_8xx_OSCLK - PLL input clock (either EXTCLK
404 - 859/866/885 CPU options: (if using a MPC859 or MPC866 or MPC885 CPU):
405 CONFIG_SYS_8xx_CPUCLK_MIN
406 CONFIG_SYS_8xx_CPUCLK_MAX
407 CONFIG_8xx_CPUCLK_DEFAULT
408 See doc/README.MPC866
410 CONFIG_SYS_MEASURE_CPUCLK
412 Define this to measure the actual CPU clock instead
413 of relying on the correctness of the configured
414 values. Mostly useful for board bringup to make sure
415 the PLL is locked at the intended frequency. Note
416 that this requires a (stable) reference clock (32 kHz
417 RTC clock or CONFIG_SYS_8XX_XIN)
419 CONFIG_SYS_DELAYED_ICACHE
421 Define this option if you want to enable the
422 ICache only when Code runs from RAM.
427 Specifies that the core is a 64-bit PowerPC implementation (implements
428 the "64" category of the Power ISA). This is necessary for ePAPR
429 compliance, among other possible reasons.
431 CONFIG_SYS_FSL_TBCLK_DIV
433 Defines the core time base clock divider ratio compared to the
434 system clock. On most PQ3 devices this is 8, on newer QorIQ
435 devices it can be 16 or 32. The ratio varies from SoC to Soc.
437 CONFIG_SYS_FSL_PCIE_COMPAT
439 Defines the string to utilize when trying to match PCIe device
440 tree nodes for the given platform.
442 CONFIG_SYS_PPC_E500_DEBUG_TLB
444 Enables a temporary TLB entry to be used during boot to work
445 around limitations in e500v1 and e500v2 external debugger
446 support. This reduces the portions of the boot code where
447 breakpoints and single stepping do not work. The value of this
448 symbol should be set to the TLB1 entry to be used for this
451 CONFIG_SYS_FSL_ERRATUM_A004510
453 Enables a workaround for erratum A004510. If set,
454 then CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV and
455 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY must be set.
457 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV
458 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV2 (optional)
460 Defines one or two SoC revisions (low 8 bits of SVR)
461 for which the A004510 workaround should be applied.
463 The rest of SVR is either not relevant to the decision
464 of whether the erratum is present (e.g. p2040 versus
465 p2041) or is implied by the build target, which controls
466 whether CONFIG_SYS_FSL_ERRATUM_A004510 is set.
468 See Freescale App Note 4493 for more information about
471 CONFIG_A003399_NOR_WORKAROUND
472 Enables a workaround for IFC erratum A003399. It is only
473 required during NOR boot.
475 CONFIG_A008044_WORKAROUND
476 Enables a workaround for T1040/T1042 erratum A008044. It is only
477 required during NAND boot and valid for Rev 1.0 SoC revision
479 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY
481 This is the value to write into CCSR offset 0x18600
482 according to the A004510 workaround.
484 CONFIG_SYS_FSL_DSP_DDR_ADDR
485 This value denotes start offset of DDR memory which is
486 connected exclusively to the DSP cores.
488 CONFIG_SYS_FSL_DSP_M2_RAM_ADDR
489 This value denotes start offset of M2 memory
490 which is directly connected to the DSP core.
492 CONFIG_SYS_FSL_DSP_M3_RAM_ADDR
493 This value denotes start offset of M3 memory which is directly
494 connected to the DSP core.
496 CONFIG_SYS_FSL_DSP_CCSRBAR_DEFAULT
497 This value denotes start offset of DSP CCSR space.
499 CONFIG_SYS_FSL_SINGLE_SOURCE_CLK
500 Single Source Clock is clocking mode present in some of FSL SoC's.
501 In this mode, a single differential clock is used to supply
502 clocks to the sysclock, ddrclock and usbclock.
504 CONFIG_SYS_CPC_REINIT_F
505 This CONFIG is defined when the CPC is configured as SRAM at the
506 time of U-boot entry and is required to be re-initialized.
509 Indicates this SoC supports deep sleep feature. If deep sleep is
510 supported, core will start to execute uboot when wakes up.
512 - Generic CPU options:
513 CONFIG_SYS_GENERIC_GLOBAL_DATA
514 Defines global data is initialized in generic board board_init_f().
515 If this macro is defined, global data is created and cleared in
516 generic board board_init_f(). Without this macro, architecture/board
517 should initialize global data before calling board_init_f().
519 CONFIG_SYS_BIG_ENDIAN, CONFIG_SYS_LITTLE_ENDIAN
521 Defines the endianess of the CPU. Implementation of those
522 values is arch specific.
525 Freescale DDR driver in use. This type of DDR controller is
526 found in mpc83xx, mpc85xx, mpc86xx as well as some ARM core
529 CONFIG_SYS_FSL_DDR_ADDR
530 Freescale DDR memory-mapped register base.
532 CONFIG_SYS_FSL_DDR_EMU
533 Specify emulator support for DDR. Some DDR features such as
534 deskew training are not available.
536 CONFIG_SYS_FSL_DDRC_GEN1
537 Freescale DDR1 controller.
539 CONFIG_SYS_FSL_DDRC_GEN2
540 Freescale DDR2 controller.
542 CONFIG_SYS_FSL_DDRC_GEN3
543 Freescale DDR3 controller.
545 CONFIG_SYS_FSL_DDRC_GEN4
546 Freescale DDR4 controller.
548 CONFIG_SYS_FSL_DDRC_ARM_GEN3
549 Freescale DDR3 controller for ARM-based SoCs.
552 Board config to use DDR1. It can be enabled for SoCs with
553 Freescale DDR1 or DDR2 controllers, depending on the board
557 Board config to use DDR2. It can be eanbeld for SoCs with
558 Freescale DDR2 or DDR3 controllers, depending on the board
562 Board config to use DDR3. It can be enabled for SoCs with
563 Freescale DDR3 or DDR3L controllers.
566 Board config to use DDR3L. It can be enabled for SoCs with
570 Board config to use DDR4. It can be enabled for SoCs with
573 CONFIG_SYS_FSL_IFC_BE
574 Defines the IFC controller register space as Big Endian
576 CONFIG_SYS_FSL_IFC_LE
577 Defines the IFC controller register space as Little Endian
579 CONFIG_SYS_FSL_PBL_PBI
580 It enables addition of RCW (Power on reset configuration) in built image.
581 Please refer doc/README.pblimage for more details
583 CONFIG_SYS_FSL_PBL_RCW
584 It adds PBI(pre-boot instructions) commands in u-boot build image.
585 PBI commands can be used to configure SoC before it starts the execution.
586 Please refer doc/README.pblimage for more details
589 It adds a target to create boot binary having SPL binary in PBI format
590 concatenated with u-boot binary.
592 CONFIG_SYS_FSL_DDR_BE
593 Defines the DDR controller register space as Big Endian
595 CONFIG_SYS_FSL_DDR_LE
596 Defines the DDR controller register space as Little Endian
598 CONFIG_SYS_FSL_DDR_SDRAM_BASE_PHY
599 Physical address from the view of DDR controllers. It is the
600 same as CONFIG_SYS_DDR_SDRAM_BASE for all Power SoCs. But
601 it could be different for ARM SoCs.
603 CONFIG_SYS_FSL_DDR_INTLV_256B
604 DDR controller interleaving on 256-byte. This is a special
605 interleaving mode, handled by Dickens for Freescale layerscape
608 CONFIG_SYS_FSL_DDR_MAIN_NUM_CTRLS
609 Number of controllers used as main memory.
611 CONFIG_SYS_FSL_OTHER_DDR_NUM_CTRLS
612 Number of controllers used for other than main memory.
614 CONFIG_SYS_FSL_SEC_BE
615 Defines the SEC controller register space as Big Endian
617 CONFIG_SYS_FSL_SEC_LE
618 Defines the SEC controller register space as Little Endian
620 - Intel Monahans options:
621 CONFIG_SYS_MONAHANS_RUN_MODE_OSC_RATIO
623 Defines the Monahans run mode to oscillator
624 ratio. Valid values are 8, 16, 24, 31. The core
625 frequency is this value multiplied by 13 MHz.
627 CONFIG_SYS_MONAHANS_TURBO_RUN_MODE_RATIO
629 Defines the Monahans turbo mode to oscillator
630 ratio. Valid values are 1 (default if undefined) and
631 2. The core frequency as calculated above is multiplied
635 CONFIG_SYS_INIT_SP_OFFSET
637 Offset relative to CONFIG_SYS_SDRAM_BASE for initial stack
638 pointer. This is needed for the temporary stack before
641 CONFIG_SYS_MIPS_CACHE_MODE
643 Cache operation mode for the MIPS CPU.
644 See also arch/mips/include/asm/mipsregs.h.
646 CONF_CM_CACHABLE_NO_WA
649 CONF_CM_CACHABLE_NONCOHERENT
653 CONF_CM_CACHABLE_ACCELERATED
655 CONFIG_SYS_XWAY_EBU_BOOTCFG
657 Special option for Lantiq XWAY SoCs for booting from NOR flash.
658 See also arch/mips/cpu/mips32/start.S.
660 CONFIG_XWAY_SWAP_BYTES
662 Enable compilation of tools/xway-swap-bytes needed for Lantiq
663 XWAY SoCs for booting from NOR flash. The U-Boot image needs to
664 be swapped if a flash programmer is used.
667 CONFIG_SYS_EXCEPTION_VECTORS_HIGH
669 Select high exception vectors of the ARM core, e.g., do not
670 clear the V bit of the c1 register of CP15.
672 CONFIG_SYS_THUMB_BUILD
674 Use this flag to build U-Boot using the Thumb instruction
675 set for ARM architectures. Thumb instruction set provides
676 better code density. For ARM architectures that support
677 Thumb2 this flag will result in Thumb2 code generated by
680 CONFIG_ARM_ERRATA_716044
681 CONFIG_ARM_ERRATA_742230
682 CONFIG_ARM_ERRATA_743622
683 CONFIG_ARM_ERRATA_751472
684 CONFIG_ARM_ERRATA_794072
685 CONFIG_ARM_ERRATA_761320
687 If set, the workarounds for these ARM errata are applied early
688 during U-Boot startup. Note that these options force the
689 workarounds to be applied; no CPU-type/version detection
690 exists, unlike the similar options in the Linux kernel. Do not
691 set these options unless they apply!
694 Generic timer clock source frequency.
696 COUNTER_FREQUENCY_REAL
697 Generic timer clock source frequency if the real clock is
698 different from COUNTER_FREQUENCY, and can only be determined
701 NOTE: The following can be machine specific errata. These
702 do have ability to provide rudimentary version and machine
703 specific checks, but expect no product checks.
704 CONFIG_ARM_ERRATA_430973
705 CONFIG_ARM_ERRATA_454179
706 CONFIG_ARM_ERRATA_621766
707 CONFIG_ARM_ERRATA_798870
710 CONFIG_TEGRA_SUPPORT_NON_SECURE
712 Support executing U-Boot in non-secure (NS) mode. Certain
713 impossible actions will be skipped if the CPU is in NS mode,
714 such as ARM architectural timer initialization.
716 - Linux Kernel Interface:
719 U-Boot stores all clock information in Hz
720 internally. For binary compatibility with older Linux
721 kernels (which expect the clocks passed in the
722 bd_info data to be in MHz) the environment variable
723 "clocks_in_mhz" can be defined so that U-Boot
724 converts clock data to MHZ before passing it to the
726 When CONFIG_CLOCKS_IN_MHZ is defined, a definition of
727 "clocks_in_mhz=1" is automatically included in the
730 CONFIG_MEMSIZE_IN_BYTES [relevant for MIPS only]
732 When transferring memsize parameter to Linux, some versions
733 expect it to be in bytes, others in MB.
734 Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes.
738 New kernel versions are expecting firmware settings to be
739 passed using flattened device trees (based on open firmware
743 * New libfdt-based support
744 * Adds the "fdt" command
745 * The bootm command automatically updates the fdt
747 OF_CPU - The proper name of the cpus node (only required for
748 MPC512X and MPC5xxx based boards).
749 OF_SOC - The proper name of the soc node (only required for
750 MPC512X and MPC5xxx based boards).
751 OF_TBCLK - The timebase frequency.
752 OF_STDOUT_PATH - The path to the console device
754 boards with QUICC Engines require OF_QE to set UCC MAC
757 CONFIG_OF_BOARD_SETUP
759 Board code has addition modification that it wants to make
760 to the flat device tree before handing it off to the kernel
762 CONFIG_OF_SYSTEM_SETUP
764 Other code has addition modification that it wants to make
765 to the flat device tree before handing it off to the kernel.
766 This causes ft_system_setup() to be called before booting
771 This define fills in the correct boot CPU in the boot
772 param header, the default value is zero if undefined.
776 U-Boot can detect if an IDE device is present or not.
777 If not, and this new config option is activated, U-Boot
778 removes the ATA node from the DTS before booting Linux,
779 so the Linux IDE driver does not probe the device and
780 crash. This is needed for buggy hardware (uc101) where
781 no pull down resistor is connected to the signal IDE5V_DD7.
783 CONFIG_MACH_TYPE [relevant for ARM only][mandatory]
785 This setting is mandatory for all boards that have only one
786 machine type and must be used to specify the machine type
787 number as it appears in the ARM machine registry
788 (see http://www.arm.linux.org.uk/developer/machines/).
789 Only boards that have multiple machine types supported
790 in a single configuration file and the machine type is
791 runtime discoverable, do not have to use this setting.
793 - vxWorks boot parameters:
795 bootvx constructs a valid bootline using the following
796 environments variables: bootfile, ipaddr, serverip, hostname.
797 It loads the vxWorks image pointed bootfile.
799 CONFIG_SYS_VXWORKS_BOOT_DEVICE - The vxworks device name
800 CONFIG_SYS_VXWORKS_MAC_PTR - Ethernet 6 byte MA -address
801 CONFIG_SYS_VXWORKS_SERVERNAME - Name of the server
802 CONFIG_SYS_VXWORKS_BOOT_ADDR - Address of boot parameters
804 CONFIG_SYS_VXWORKS_ADD_PARAMS
806 Add it at the end of the bootline. E.g "u=username pw=secret"
808 Note: If a "bootargs" environment is defined, it will overwride
809 the defaults discussed just above.
811 - Cache Configuration:
812 CONFIG_SYS_ICACHE_OFF - Do not enable instruction cache in U-Boot
813 CONFIG_SYS_DCACHE_OFF - Do not enable data cache in U-Boot
814 CONFIG_SYS_L2CACHE_OFF- Do not enable L2 cache in U-Boot
816 - Cache Configuration for ARM:
817 CONFIG_SYS_L2_PL310 - Enable support for ARM PL310 L2 cache
819 CONFIG_SYS_PL310_BASE - Physical base address of PL310
820 controller register space
825 Define this if you want support for Amba PrimeCell PL010 UARTs.
829 Define this if you want support for Amba PrimeCell PL011 UARTs.
833 If you have Amba PrimeCell PL011 UARTs, set this variable to
834 the clock speed of the UARTs.
838 If you have Amba PrimeCell PL010 or PL011 UARTs on your board,
839 define this to a list of base addresses for each (supported)
840 port. See e.g. include/configs/versatile.h
842 CONFIG_PL011_SERIAL_RLCR
844 Some vendor versions of PL011 serial ports (e.g. ST-Ericsson U8500)
845 have separate receive and transmit line control registers. Set
846 this variable to initialize the extra register.
848 CONFIG_PL011_SERIAL_FLUSH_ON_INIT
850 On some platforms (e.g. U8500) U-Boot is loaded by a second stage
851 boot loader that has already initialized the UART. Define this
852 variable to flush the UART at init time.
854 CONFIG_SERIAL_HW_FLOW_CONTROL
856 Define this variable to enable hw flow control in serial driver.
857 Current user of this option is drivers/serial/nsl16550.c driver
860 Depending on board, define exactly one serial port
861 (like CONFIG_8xx_CONS_SMC1, CONFIG_8xx_CONS_SMC2,
862 CONFIG_8xx_CONS_SCC1, ...), or switch off the serial
863 console by defining CONFIG_8xx_CONS_NONE
865 Note: if CONFIG_8xx_CONS_NONE is defined, the serial
866 port routines must be defined elsewhere
867 (i.e. serial_init(), serial_getc(), ...)
870 Enables console device for a color framebuffer. Needs following
871 defines (cf. smiLynxEM, i8042)
872 VIDEO_FB_LITTLE_ENDIAN graphic memory organisation
874 VIDEO_HW_RECTFILL graphic chip supports
877 VIDEO_HW_BITBLT graphic chip supports
878 bit-blit (cf. smiLynxEM)
879 VIDEO_VISIBLE_COLS visible pixel columns
881 VIDEO_VISIBLE_ROWS visible pixel rows
882 VIDEO_PIXEL_SIZE bytes per pixel
883 VIDEO_DATA_FORMAT graphic data format
884 (0-5, cf. cfb_console.c)
885 VIDEO_FB_ADRS framebuffer address
886 VIDEO_KBD_INIT_FCT keyboard int fct
887 (i.e. i8042_kbd_init())
888 VIDEO_TSTC_FCT test char fct
890 VIDEO_GETC_FCT get char fct
892 CONFIG_CONSOLE_CURSOR cursor drawing on/off
893 (requires blink timer
895 CONFIG_SYS_CONSOLE_BLINK_COUNT blink interval (cf. i8042.c)
896 CONFIG_CONSOLE_TIME display time/date info in
898 (requires CONFIG_CMD_DATE)
899 CONFIG_VIDEO_LOGO display Linux logo in
901 CONFIG_VIDEO_BMP_LOGO use bmp_logo.h instead of
902 linux_logo.h for logo.
903 Requires CONFIG_VIDEO_LOGO
904 CONFIG_CONSOLE_EXTRA_INFO
905 additional board info beside
908 When CONFIG_CFB_CONSOLE_ANSI is defined, console will support
909 a limited number of ANSI escape sequences (cursor control,
910 erase functions and limited graphics rendition control).
912 When CONFIG_CFB_CONSOLE is defined, video console is
913 default i/o. Serial console can be forced with
914 environment 'console=serial'.
916 When CONFIG_SILENT_CONSOLE is defined, all console
917 messages (by U-Boot and Linux!) can be silenced with
918 the "silent" environment variable. See
919 doc/README.silent for more information.
921 CONFIG_SYS_CONSOLE_BG_COL: define the backgroundcolor, default
923 CONFIG_SYS_CONSOLE_FG_COL: define the foregroundcolor, default
927 CONFIG_BAUDRATE - in bps
928 Select one of the baudrates listed in
929 CONFIG_SYS_BAUDRATE_TABLE, see below.
930 CONFIG_SYS_BRGCLK_PRESCALE, baudrate prescale
932 - Console Rx buffer length
933 With CONFIG_SYS_SMC_RXBUFLEN it is possible to define
934 the maximum receive buffer length for the SMC.
935 This option is actual only for 82xx and 8xx possible.
936 If using CONFIG_SYS_SMC_RXBUFLEN also CONFIG_SYS_MAXIDLE
937 must be defined, to setup the maximum idle timeout for
940 - Pre-Console Buffer:
941 Prior to the console being initialised (i.e. serial UART
942 initialised etc) all console output is silently discarded.
943 Defining CONFIG_PRE_CONSOLE_BUFFER will cause U-Boot to
944 buffer any console messages prior to the console being
945 initialised to a buffer of size CONFIG_PRE_CON_BUF_SZ
946 bytes located at CONFIG_PRE_CON_BUF_ADDR. The buffer is
947 a circular buffer, so if more than CONFIG_PRE_CON_BUF_SZ
948 bytes are output before the console is initialised, the
949 earlier bytes are discarded.
951 Note that when printing the buffer a copy is made on the
952 stack so CONFIG_PRE_CON_BUF_SZ must fit on the stack.
954 'Sane' compilers will generate smaller code if
955 CONFIG_PRE_CON_BUF_SZ is a power of 2
957 - Safe printf() functions
958 Define CONFIG_SYS_VSNPRINTF to compile in safe versions of
959 the printf() functions. These are defined in
960 include/vsprintf.h and include snprintf(), vsnprintf() and
961 so on. Code size increase is approximately 300-500 bytes.
962 If this option is not given then these functions will
963 silently discard their buffer size argument - this means
964 you are not getting any overflow checking in this case.
966 - Boot Delay: CONFIG_BOOTDELAY - in seconds
967 Delay before automatically booting the default image;
968 set to -1 to disable autoboot.
969 set to -2 to autoboot with no delay and not check for abort
970 (even when CONFIG_ZERO_BOOTDELAY_CHECK is defined).
972 See doc/README.autoboot for these options that
973 work with CONFIG_BOOTDELAY. None are required.
974 CONFIG_BOOT_RETRY_TIME
975 CONFIG_BOOT_RETRY_MIN
976 CONFIG_AUTOBOOT_KEYED
977 CONFIG_AUTOBOOT_PROMPT
978 CONFIG_AUTOBOOT_DELAY_STR
979 CONFIG_AUTOBOOT_STOP_STR
980 CONFIG_ZERO_BOOTDELAY_CHECK
981 CONFIG_RESET_TO_RETRY
985 Only needed when CONFIG_BOOTDELAY is enabled;
986 define a command string that is automatically executed
987 when no character is read on the console interface
988 within "Boot Delay" after reset.
991 This can be used to pass arguments to the bootm
992 command. The value of CONFIG_BOOTARGS goes into the
993 environment value "bootargs".
995 CONFIG_RAMBOOT and CONFIG_NFSBOOT
996 The value of these goes into the environment as
997 "ramboot" and "nfsboot" respectively, and can be used
998 as a convenience, when switching between booting from
1002 CONFIG_BOOTCOUNT_LIMIT
1003 Implements a mechanism for detecting a repeating reboot
1005 http://www.denx.de/wiki/view/DULG/UBootBootCountLimit
1007 CONFIG_BOOTCOUNT_ENV
1008 If no softreset save registers are found on the hardware
1009 "bootcount" is stored in the environment. To prevent a
1010 saveenv on all reboots, the environment variable
1011 "upgrade_available" is used. If "upgrade_available" is
1012 0, "bootcount" is always 0, if "upgrade_available" is
1013 1 "bootcount" is incremented in the environment.
1014 So the Userspace Applikation must set the "upgrade_available"
1015 and "bootcount" variable to 0, if a boot was successfully.
1017 - Pre-Boot Commands:
1020 When this option is #defined, the existence of the
1021 environment variable "preboot" will be checked
1022 immediately before starting the CONFIG_BOOTDELAY
1023 countdown and/or running the auto-boot command resp.
1024 entering interactive mode.
1026 This feature is especially useful when "preboot" is
1027 automatically generated or modified. For an example
1028 see the LWMON board specific code: here "preboot" is
1029 modified when the user holds down a certain
1030 combination of keys on the (special) keyboard when
1033 - Serial Download Echo Mode:
1035 If defined to 1, all characters received during a
1036 serial download (using the "loads" command) are
1037 echoed back. This might be needed by some terminal
1038 emulations (like "cu"), but may as well just take
1039 time on others. This setting #define's the initial
1040 value of the "loads_echo" environment variable.
1042 - Kgdb Serial Baudrate: (if CONFIG_CMD_KGDB is defined)
1043 CONFIG_KGDB_BAUDRATE
1044 Select one of the baudrates listed in
1045 CONFIG_SYS_BAUDRATE_TABLE, see below.
1047 - Monitor Functions:
1048 Monitor commands can be included or excluded
1049 from the build by using the #include files
1050 <config_cmd_all.h> and #undef'ing unwanted
1051 commands, or using <config_cmd_default.h>
1052 and augmenting with additional #define's
1053 for wanted commands.
1055 The default command configuration includes all commands
1056 except those marked below with a "*".
1058 CONFIG_CMD_AES AES 128 CBC encrypt/decrypt
1059 CONFIG_CMD_ASKENV * ask for env variable
1060 CONFIG_CMD_BDI bdinfo
1061 CONFIG_CMD_BEDBUG * Include BedBug Debugger
1062 CONFIG_CMD_BMP * BMP support
1063 CONFIG_CMD_BSP * Board specific commands
1064 CONFIG_CMD_BOOTD bootd
1065 CONFIG_CMD_BOOTI * ARM64 Linux kernel Image support
1066 CONFIG_CMD_CACHE * icache, dcache
1067 CONFIG_CMD_CLK * clock command support
1068 CONFIG_CMD_CONSOLE coninfo
1069 CONFIG_CMD_CRC32 * crc32
1070 CONFIG_CMD_DATE * support for RTC, date/time...
1071 CONFIG_CMD_DHCP * DHCP support
1072 CONFIG_CMD_DIAG * Diagnostics
1073 CONFIG_CMD_DS4510 * ds4510 I2C gpio commands
1074 CONFIG_CMD_DS4510_INFO * ds4510 I2C info command
1075 CONFIG_CMD_DS4510_MEM * ds4510 I2C eeprom/sram commansd
1076 CONFIG_CMD_DS4510_RST * ds4510 I2C rst command
1077 CONFIG_CMD_DTT * Digital Therm and Thermostat
1078 CONFIG_CMD_ECHO echo arguments
1079 CONFIG_CMD_EDITENV edit env variable
1080 CONFIG_CMD_EEPROM * EEPROM read/write support
1081 CONFIG_CMD_ELF * bootelf, bootvx
1082 CONFIG_CMD_ENV_CALLBACK * display details about env callbacks
1083 CONFIG_CMD_ENV_FLAGS * display details about env flags
1084 CONFIG_CMD_ENV_EXISTS * check existence of env variable
1085 CONFIG_CMD_EXPORTENV * export the environment
1086 CONFIG_CMD_EXT2 * ext2 command support
1087 CONFIG_CMD_EXT4 * ext4 command support
1088 CONFIG_CMD_FS_GENERIC * filesystem commands (e.g. load, ls)
1089 that work for multiple fs types
1090 CONFIG_CMD_FS_UUID * Look up a filesystem UUID
1091 CONFIG_CMD_SAVEENV saveenv
1092 CONFIG_CMD_FDC * Floppy Disk Support
1093 CONFIG_CMD_FAT * FAT command support
1094 CONFIG_CMD_FLASH flinfo, erase, protect
1095 CONFIG_CMD_FPGA FPGA device initialization support
1096 CONFIG_CMD_FUSE * Device fuse support
1097 CONFIG_CMD_GETTIME * Get time since boot
1098 CONFIG_CMD_GO * the 'go' command (exec code)
1099 CONFIG_CMD_GREPENV * search environment
1100 CONFIG_CMD_HASH * calculate hash / digest
1101 CONFIG_CMD_HWFLOW * RTS/CTS hw flow control
1102 CONFIG_CMD_I2C * I2C serial bus support
1103 CONFIG_CMD_IDE * IDE harddisk support
1104 CONFIG_CMD_IMI iminfo
1105 CONFIG_CMD_IMLS List all images found in NOR flash
1106 CONFIG_CMD_IMLS_NAND * List all images found in NAND flash
1107 CONFIG_CMD_IMMAP * IMMR dump support
1108 CONFIG_CMD_IOTRACE * I/O tracing for debugging
1109 CONFIG_CMD_IMPORTENV * import an environment
1110 CONFIG_CMD_INI * import data from an ini file into the env
1111 CONFIG_CMD_IRQ * irqinfo
1112 CONFIG_CMD_ITEST Integer/string test of 2 values
1113 CONFIG_CMD_JFFS2 * JFFS2 Support
1114 CONFIG_CMD_KGDB * kgdb
1115 CONFIG_CMD_LDRINFO * ldrinfo (display Blackfin loader)
1116 CONFIG_CMD_LINK_LOCAL * link-local IP address auto-configuration
1118 CONFIG_CMD_LOADB loadb
1119 CONFIG_CMD_LOADS loads
1120 CONFIG_CMD_MD5SUM * print md5 message digest
1121 (requires CONFIG_CMD_MEMORY and CONFIG_MD5)
1122 CONFIG_CMD_MEMINFO * Display detailed memory information
1123 CONFIG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base,
1125 CONFIG_CMD_MEMTEST * mtest
1126 CONFIG_CMD_MISC Misc functions like sleep etc
1127 CONFIG_CMD_MMC * MMC memory mapped support
1128 CONFIG_CMD_MII * MII utility commands
1129 CONFIG_CMD_MTDPARTS * MTD partition support
1130 CONFIG_CMD_NAND * NAND support
1131 CONFIG_CMD_NET bootp, tftpboot, rarpboot
1132 CONFIG_CMD_NFS NFS support
1133 CONFIG_CMD_PCA953X * PCA953x I2C gpio commands
1134 CONFIG_CMD_PCA953X_INFO * PCA953x I2C gpio info command
1135 CONFIG_CMD_PCI * pciinfo
1136 CONFIG_CMD_PCMCIA * PCMCIA support
1137 CONFIG_CMD_PING * send ICMP ECHO_REQUEST to network
1139 CONFIG_CMD_PORTIO * Port I/O
1140 CONFIG_CMD_READ * Read raw data from partition
1141 CONFIG_CMD_REGINFO * Register dump
1142 CONFIG_CMD_RUN run command in env variable
1143 CONFIG_CMD_SANDBOX * sb command to access sandbox features
1144 CONFIG_CMD_SAVES * save S record dump
1145 CONFIG_CMD_SCSI * SCSI Support
1146 CONFIG_CMD_SDRAM * print SDRAM configuration information
1147 (requires CONFIG_CMD_I2C)
1148 CONFIG_CMD_SETGETDCR Support for DCR Register access
1150 CONFIG_CMD_SF * Read/write/erase SPI NOR flash
1151 CONFIG_CMD_SHA1SUM * print sha1 memory digest
1152 (requires CONFIG_CMD_MEMORY)
1153 CONFIG_CMD_SOFTSWITCH * Soft switch setting command for BF60x
1154 CONFIG_CMD_SOURCE "source" command Support
1155 CONFIG_CMD_SPI * SPI serial bus support
1156 CONFIG_CMD_TFTPSRV * TFTP transfer in server mode
1157 CONFIG_CMD_TFTPPUT * TFTP put command (upload)
1158 CONFIG_CMD_TIME * run command and report execution time (ARM specific)
1159 CONFIG_CMD_TIMER * access to the system tick timer
1160 CONFIG_CMD_USB * USB support
1161 CONFIG_CMD_CDP * Cisco Discover Protocol support
1162 CONFIG_CMD_MFSL * Microblaze FSL support
1163 CONFIG_CMD_XIMG Load part of Multi Image
1164 CONFIG_CMD_UUID * Generate random UUID or GUID string
1166 EXAMPLE: If you want all functions except of network
1167 support you can write:
1169 #include "config_cmd_all.h"
1170 #undef CONFIG_CMD_NET
1173 fdt (flattened device tree) command: CONFIG_OF_LIBFDT
1175 Note: Don't enable the "icache" and "dcache" commands
1176 (configuration option CONFIG_CMD_CACHE) unless you know
1177 what you (and your U-Boot users) are doing. Data
1178 cache cannot be enabled on systems like the 8xx or
1179 8260 (where accesses to the IMMR region must be
1180 uncached), and it cannot be disabled on all other
1181 systems where we (mis-) use the data cache to hold an
1182 initial stack and some data.
1185 XXX - this list needs to get updated!
1187 - Regular expression support:
1189 If this variable is defined, U-Boot is linked against
1190 the SLRE (Super Light Regular Expression) library,
1191 which adds regex support to some commands, as for
1192 example "env grep" and "setexpr".
1196 If this variable is defined, U-Boot will use a device tree
1197 to configure its devices, instead of relying on statically
1198 compiled #defines in the board file. This option is
1199 experimental and only available on a few boards. The device
1200 tree is available in the global data as gd->fdt_blob.
1202 U-Boot needs to get its device tree from somewhere. This can
1203 be done using one of the two options below:
1206 If this variable is defined, U-Boot will embed a device tree
1207 binary in its image. This device tree file should be in the
1208 board directory and called <soc>-<board>.dts. The binary file
1209 is then picked up in board_init_f() and made available through
1210 the global data structure as gd->blob.
1213 If this variable is defined, U-Boot will build a device tree
1214 binary. It will be called u-boot.dtb. Architecture-specific
1215 code will locate it at run-time. Generally this works by:
1217 cat u-boot.bin u-boot.dtb >image.bin
1219 and in fact, U-Boot does this for you, creating a file called
1220 u-boot-dtb.bin which is useful in the common case. You can
1221 still use the individual files if you need something more
1226 If this variable is defined, it enables watchdog
1227 support for the SoC. There must be support in the SoC
1228 specific code for a watchdog. For the 8xx and 8260
1229 CPUs, the SIU Watchdog feature is enabled in the SYPCR
1230 register. When supported for a specific SoC is
1231 available, then no further board specific code should
1232 be needed to use it.
1235 When using a watchdog circuitry external to the used
1236 SoC, then define this variable and provide board
1237 specific code for the "hw_watchdog_reset" function.
1239 CONFIG_AT91_HW_WDT_TIMEOUT
1240 specify the timeout in seconds. default 2 seconds.
1243 CONFIG_VERSION_VARIABLE
1244 If this variable is defined, an environment variable
1245 named "ver" is created by U-Boot showing the U-Boot
1246 version as printed by the "version" command.
1247 Any change to this variable will be reverted at the
1252 When CONFIG_CMD_DATE is selected, the type of the RTC
1253 has to be selected, too. Define exactly one of the
1256 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx
1257 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC
1258 CONFIG_RTC_MC13XXX - use MC13783 or MC13892 RTC
1259 CONFIG_RTC_MC146818 - use MC146818 RTC
1260 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC
1261 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC
1262 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC
1263 CONFIG_RTC_DS1339 - use Maxim, Inc. DS1339 RTC
1264 CONFIG_RTC_DS164x - use Dallas DS164x RTC
1265 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC
1266 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC
1267 CONFIG_SYS_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337
1268 CONFIG_SYS_RV3029_TCR - enable trickle charger on
1271 Note that if the RTC uses I2C, then the I2C interface
1272 must also be configured. See I2C Support, below.
1275 CONFIG_PCA953X - use NXP's PCA953X series I2C GPIO
1277 The CONFIG_SYS_I2C_PCA953X_WIDTH option specifies a list of
1278 chip-ngpio pairs that tell the PCA953X driver the number of
1279 pins supported by a particular chip.
1281 Note that if the GPIO device uses I2C, then the I2C interface
1282 must also be configured. See I2C Support, below.
1285 When CONFIG_IO_TRACE is selected, U-Boot intercepts all I/O
1286 accesses and can checksum them or write a list of them out
1287 to memory. See the 'iotrace' command for details. This is
1288 useful for testing device drivers since it can confirm that
1289 the driver behaves the same way before and after a code
1290 change. Currently this is supported on sandbox and arm. To
1291 add support for your architecture, add '#include <iotrace.h>'
1292 to the bottom of arch/<arch>/include/asm/io.h and test.
1294 Example output from the 'iotrace stats' command is below.
1295 Note that if the trace buffer is exhausted, the checksum will
1296 still continue to operate.
1299 Start: 10000000 (buffer start address)
1300 Size: 00010000 (buffer size)
1301 Offset: 00000120 (current buffer offset)
1302 Output: 10000120 (start + offset)
1303 Count: 00000018 (number of trace records)
1304 CRC32: 9526fb66 (CRC32 of all trace records)
1306 - Timestamp Support:
1308 When CONFIG_TIMESTAMP is selected, the timestamp
1309 (date and time) of an image is printed by image
1310 commands like bootm or iminfo. This option is
1311 automatically enabled when you select CONFIG_CMD_DATE .
1313 - Partition Labels (disklabels) Supported:
1314 Zero or more of the following:
1315 CONFIG_MAC_PARTITION Apple's MacOS partition table.
1316 CONFIG_DOS_PARTITION MS Dos partition table, traditional on the
1317 Intel architecture, USB sticks, etc.
1318 CONFIG_ISO_PARTITION ISO partition table, used on CDROM etc.
1319 CONFIG_EFI_PARTITION GPT partition table, common when EFI is the
1320 bootloader. Note 2TB partition limit; see
1322 CONFIG_MTD_PARTITIONS Memory Technology Device partition table.
1324 If IDE or SCSI support is enabled (CONFIG_CMD_IDE or
1325 CONFIG_CMD_SCSI) you must configure support for at
1326 least one non-MTD partition type as well.
1329 CONFIG_IDE_RESET_ROUTINE - this is defined in several
1330 board configurations files but used nowhere!
1332 CONFIG_IDE_RESET - is this is defined, IDE Reset will
1333 be performed by calling the function
1334 ide_set_reset(int reset)
1335 which has to be defined in a board specific file
1340 Set this to enable ATAPI support.
1345 Set this to enable support for disks larger than 137GB
1346 Also look at CONFIG_SYS_64BIT_LBA.
1347 Whithout these , LBA48 support uses 32bit variables and will 'only'
1348 support disks up to 2.1TB.
1350 CONFIG_SYS_64BIT_LBA:
1351 When enabled, makes the IDE subsystem use 64bit sector addresses.
1355 At the moment only there is only support for the
1356 SYM53C8XX SCSI controller; define
1357 CONFIG_SCSI_SYM53C8XX to enable it.
1359 CONFIG_SYS_SCSI_MAX_LUN [8], CONFIG_SYS_SCSI_MAX_SCSI_ID [7] and
1360 CONFIG_SYS_SCSI_MAX_DEVICE [CONFIG_SYS_SCSI_MAX_SCSI_ID *
1361 CONFIG_SYS_SCSI_MAX_LUN] can be adjusted to define the
1362 maximum numbers of LUNs, SCSI ID's and target
1364 CONFIG_SYS_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz)
1366 The environment variable 'scsidevs' is set to the number of
1367 SCSI devices found during the last scan.
1369 - NETWORK Support (PCI):
1371 Support for Intel 8254x/8257x gigabit chips.
1374 Utility code for direct access to the SPI bus on Intel 8257x.
1375 This does not do anything useful unless you set at least one
1376 of CONFIG_CMD_E1000 or CONFIG_E1000_SPI_GENERIC.
1378 CONFIG_E1000_SPI_GENERIC
1379 Allow generic access to the SPI bus on the Intel 8257x, for
1380 example with the "sspi" command.
1383 Management command for E1000 devices. When used on devices
1384 with SPI support you can reprogram the EEPROM from U-Boot.
1386 CONFIG_E1000_FALLBACK_MAC
1387 default MAC for empty EEPROM after production.
1390 Support for Intel 82557/82559/82559ER chips.
1391 Optional CONFIG_EEPRO100_SROM_WRITE enables EEPROM
1392 write routine for first time initialisation.
1395 Support for Digital 2114x chips.
1396 Optional CONFIG_TULIP_SELECT_MEDIA for board specific
1397 modem chip initialisation (KS8761/QS6611).
1400 Support for National dp83815 chips.
1403 Support for National dp8382[01] gigabit chips.
1405 - NETWORK Support (other):
1407 CONFIG_DRIVER_AT91EMAC
1408 Support for AT91RM9200 EMAC.
1411 Define this to use reduced MII inteface
1413 CONFIG_DRIVER_AT91EMAC_QUIET
1414 If this defined, the driver is quiet.
1415 The driver doen't show link status messages.
1417 CONFIG_CALXEDA_XGMAC
1418 Support for the Calxeda XGMAC device
1421 Support for SMSC's LAN91C96 chips.
1423 CONFIG_LAN91C96_BASE
1424 Define this to hold the physical address
1425 of the LAN91C96's I/O space
1427 CONFIG_LAN91C96_USE_32_BIT
1428 Define this to enable 32 bit addressing
1431 Support for SMSC's LAN91C111 chip
1433 CONFIG_SMC91111_BASE
1434 Define this to hold the physical address
1435 of the device (I/O space)
1437 CONFIG_SMC_USE_32_BIT
1438 Define this if data bus is 32 bits
1440 CONFIG_SMC_USE_IOFUNCS
1441 Define this to use i/o functions instead of macros
1442 (some hardware wont work with macros)
1444 CONFIG_DRIVER_TI_EMAC
1445 Support for davinci emac
1447 CONFIG_SYS_DAVINCI_EMAC_PHY_COUNT
1448 Define this if you have more then 3 PHYs.
1451 Support for Faraday's FTGMAC100 Gigabit SoC Ethernet
1453 CONFIG_FTGMAC100_EGIGA
1454 Define this to use GE link update with gigabit PHY.
1455 Define this if FTGMAC100 is connected to gigabit PHY.
1456 If your system has 10/100 PHY only, it might not occur
1457 wrong behavior. Because PHY usually return timeout or
1458 useless data when polling gigabit status and gigabit
1459 control registers. This behavior won't affect the
1460 correctnessof 10/100 link speed update.
1463 Support for SMSC's LAN911x and LAN921x chips
1466 Define this to hold the physical address
1467 of the device (I/O space)
1469 CONFIG_SMC911X_32_BIT
1470 Define this if data bus is 32 bits
1472 CONFIG_SMC911X_16_BIT
1473 Define this if data bus is 16 bits. If your processor
1474 automatically converts one 32 bit word to two 16 bit
1475 words you may also try CONFIG_SMC911X_32_BIT.
1478 Support for Renesas on-chip Ethernet controller
1480 CONFIG_SH_ETHER_USE_PORT
1481 Define the number of ports to be used
1483 CONFIG_SH_ETHER_PHY_ADDR
1484 Define the ETH PHY's address
1486 CONFIG_SH_ETHER_CACHE_WRITEBACK
1487 If this option is set, the driver enables cache flush.
1491 Support for PWM modul on the imx6.
1495 Support TPM devices.
1498 Support for i2c bus TPM devices. Only one device
1499 per system is supported at this time.
1501 CONFIG_TPM_TIS_I2C_BUS_NUMBER
1502 Define the the i2c bus number for the TPM device
1504 CONFIG_TPM_TIS_I2C_SLAVE_ADDRESS
1505 Define the TPM's address on the i2c bus
1507 CONFIG_TPM_TIS_I2C_BURST_LIMITATION
1508 Define the burst count bytes upper limit
1510 CONFIG_TPM_ATMEL_TWI
1511 Support for Atmel TWI TPM device. Requires I2C support.
1514 Support for generic parallel port TPM devices. Only one device
1515 per system is supported at this time.
1517 CONFIG_TPM_TIS_BASE_ADDRESS
1518 Base address where the generic TPM device is mapped
1519 to. Contemporary x86 systems usually map it at
1523 Add tpm monitor functions.
1524 Requires CONFIG_TPM. If CONFIG_TPM_AUTH_SESSIONS is set, also
1525 provides monitor access to authorized functions.
1528 Define this to enable the TPM support library which provides
1529 functional interfaces to some TPM commands.
1530 Requires support for a TPM device.
1532 CONFIG_TPM_AUTH_SESSIONS
1533 Define this to enable authorized functions in the TPM library.
1534 Requires CONFIG_TPM and CONFIG_SHA1.
1537 At the moment only the UHCI host controller is
1538 supported (PIP405, MIP405, MPC5200); define
1539 CONFIG_USB_UHCI to enable it.
1540 define CONFIG_USB_KEYBOARD to enable the USB Keyboard
1541 and define CONFIG_USB_STORAGE to enable the USB
1544 Supported are USB Keyboards and USB Floppy drives
1546 MPC5200 USB requires additional defines:
1548 for 528 MHz Clock: 0x0001bbbb
1552 for differential drivers: 0x00001000
1553 for single ended drivers: 0x00005000
1554 for differential drivers on PSC3: 0x00000100
1555 for single ended drivers on PSC3: 0x00004100
1556 CONFIG_SYS_USB_EVENT_POLL
1557 May be defined to allow interrupt polling
1558 instead of using asynchronous interrupts
1560 CONFIG_USB_EHCI_TXFIFO_THRESH enables setting of the
1561 txfilltuning field in the EHCI controller on reset.
1563 CONFIG_USB_DWC2_REG_ADDR the physical CPU address of the DWC2
1564 HW module registers.
1567 Define the below if you wish to use the USB console.
1568 Once firmware is rebuilt from a serial console issue the
1569 command "setenv stdin usbtty; setenv stdout usbtty" and
1570 attach your USB cable. The Unix command "dmesg" should print
1571 it has found a new device. The environment variable usbtty
1572 can be set to gserial or cdc_acm to enable your device to
1573 appear to a USB host as a Linux gserial device or a
1574 Common Device Class Abstract Control Model serial device.
1575 If you select usbtty = gserial you should be able to enumerate
1577 # modprobe usbserial vendor=0xVendorID product=0xProductID
1578 else if using cdc_acm, simply setting the environment
1579 variable usbtty to be cdc_acm should suffice. The following
1580 might be defined in YourBoardName.h
1583 Define this to build a UDC device
1586 Define this to have a tty type of device available to
1587 talk to the UDC device
1590 Define this to enable the high speed support for usb
1591 device and usbtty. If this feature is enabled, a routine
1592 int is_usbd_high_speed(void)
1593 also needs to be defined by the driver to dynamically poll
1594 whether the enumeration has succeded at high speed or full
1597 CONFIG_SYS_CONSOLE_IS_IN_ENV
1598 Define this if you want stdin, stdout &/or stderr to
1602 CONFIG_SYS_USB_EXTC_CLK 0xBLAH
1603 Derive USB clock from external clock "blah"
1604 - CONFIG_SYS_USB_EXTC_CLK 0x02
1606 CONFIG_SYS_USB_BRG_CLK 0xBLAH
1607 Derive USB clock from brgclk
1608 - CONFIG_SYS_USB_BRG_CLK 0x04
1610 If you have a USB-IF assigned VendorID then you may wish to
1611 define your own vendor specific values either in BoardName.h
1612 or directly in usbd_vendor_info.h. If you don't define
1613 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME,
1614 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot
1615 should pretend to be a Linux device to it's target host.
1617 CONFIG_USBD_MANUFACTURER
1618 Define this string as the name of your company for
1619 - CONFIG_USBD_MANUFACTURER "my company"
1621 CONFIG_USBD_PRODUCT_NAME
1622 Define this string as the name of your product
1623 - CONFIG_USBD_PRODUCT_NAME "acme usb device"
1625 CONFIG_USBD_VENDORID
1626 Define this as your assigned Vendor ID from the USB
1627 Implementors Forum. This *must* be a genuine Vendor ID
1628 to avoid polluting the USB namespace.
1629 - CONFIG_USBD_VENDORID 0xFFFF
1631 CONFIG_USBD_PRODUCTID
1632 Define this as the unique Product ID
1634 - CONFIG_USBD_PRODUCTID 0xFFFF
1636 - ULPI Layer Support:
1637 The ULPI (UTMI Low Pin (count) Interface) PHYs are supported via
1638 the generic ULPI layer. The generic layer accesses the ULPI PHY
1639 via the platform viewport, so you need both the genric layer and
1640 the viewport enabled. Currently only Chipidea/ARC based
1641 viewport is supported.
1642 To enable the ULPI layer support, define CONFIG_USB_ULPI and
1643 CONFIG_USB_ULPI_VIEWPORT in your board configuration file.
1644 If your ULPI phy needs a different reference clock than the
1645 standard 24 MHz then you have to define CONFIG_ULPI_REF_CLK to
1646 the appropriate value in Hz.
1649 The MMC controller on the Intel PXA is supported. To
1650 enable this define CONFIG_MMC. The MMC can be
1651 accessed from the boot prompt by mapping the device
1652 to physical memory similar to flash. Command line is
1653 enabled with CONFIG_CMD_MMC. The MMC driver also works with
1654 the FAT fs. This is enabled with CONFIG_CMD_FAT.
1657 Support for Renesas on-chip MMCIF controller
1659 CONFIG_SH_MMCIF_ADDR
1660 Define the base address of MMCIF registers
1663 Define the clock frequency for MMCIF
1666 Enable the generic MMC driver
1668 CONFIG_SUPPORT_EMMC_BOOT
1669 Enable some additional features of the eMMC boot partitions.
1671 CONFIG_SUPPORT_EMMC_RPMB
1672 Enable the commands for reading, writing and programming the
1673 key for the Replay Protection Memory Block partition in eMMC.
1675 - USB Device Firmware Update (DFU) class support:
1677 This enables the USB portion of the DFU USB class
1680 This enables the command "dfu" which is used to have
1681 U-Boot create a DFU class device via USB. This command
1682 requires that the "dfu_alt_info" environment variable be
1683 set and define the alt settings to expose to the host.
1686 This enables support for exposing (e)MMC devices via DFU.
1689 This enables support for exposing NAND devices via DFU.
1692 This enables support for exposing RAM via DFU.
1693 Note: DFU spec refer to non-volatile memory usage, but
1694 allow usages beyond the scope of spec - here RAM usage,
1695 one that would help mostly the developer.
1697 CONFIG_SYS_DFU_DATA_BUF_SIZE
1698 Dfu transfer uses a buffer before writing data to the
1699 raw storage device. Make the size (in bytes) of this buffer
1700 configurable. The size of this buffer is also configurable
1701 through the "dfu_bufsiz" environment variable.
1703 CONFIG_SYS_DFU_MAX_FILE_SIZE
1704 When updating files rather than the raw storage device,
1705 we use a static buffer to copy the file into and then write
1706 the buffer once we've been given the whole file. Define
1707 this to the maximum filesize (in bytes) for the buffer.
1708 Default is 4 MiB if undefined.
1710 DFU_DEFAULT_POLL_TIMEOUT
1711 Poll timeout [ms], is the timeout a device can send to the
1712 host. The host must wait for this timeout before sending
1713 a subsequent DFU_GET_STATUS request to the device.
1715 DFU_MANIFEST_POLL_TIMEOUT
1716 Poll timeout [ms], which the device sends to the host when
1717 entering dfuMANIFEST state. Host waits this timeout, before
1718 sending again an USB request to the device.
1720 - USB Device Android Fastboot support:
1722 This enables the command "fastboot" which enables the Android
1723 fastboot mode for the platform's USB device. Fastboot is a USB
1724 protocol for downloading images, flashing and device control
1725 used on Android devices.
1726 See doc/README.android-fastboot for more information.
1728 CONFIG_ANDROID_BOOT_IMAGE
1729 This enables support for booting images which use the Android
1730 image format header.
1732 CONFIG_USB_FASTBOOT_BUF_ADDR
1733 The fastboot protocol requires a large memory buffer for
1734 downloads. Define this to the starting RAM address to use for
1737 CONFIG_USB_FASTBOOT_BUF_SIZE
1738 The fastboot protocol requires a large memory buffer for
1739 downloads. This buffer should be as large as possible for a
1740 platform. Define this to the size available RAM for fastboot.
1742 CONFIG_FASTBOOT_FLASH
1743 The fastboot protocol includes a "flash" command for writing
1744 the downloaded image to a non-volatile storage device. Define
1745 this to enable the "fastboot flash" command.
1747 CONFIG_FASTBOOT_FLASH_MMC_DEV
1748 The fastboot "flash" command requires additional information
1749 regarding the non-volatile storage device. Define this to
1750 the eMMC device that fastboot should use to store the image.
1752 CONFIG_FASTBOOT_GPT_NAME
1753 The fastboot "flash" command supports writing the downloaded
1754 image to the Protective MBR and the Primary GUID Partition
1755 Table. (Additionally, this downloaded image is post-processed
1756 to generate and write the Backup GUID Partition Table.)
1757 This occurs when the specified "partition name" on the
1758 "fastboot flash" command line matches this value.
1759 Default is GPT_ENTRY_NAME (currently "gpt") if undefined.
1761 - Journaling Flash filesystem support:
1762 CONFIG_JFFS2_NAND, CONFIG_JFFS2_NAND_OFF, CONFIG_JFFS2_NAND_SIZE,
1763 CONFIG_JFFS2_NAND_DEV
1764 Define these for a default partition on a NAND device
1766 CONFIG_SYS_JFFS2_FIRST_SECTOR,
1767 CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS
1768 Define these for a default partition on a NOR device
1770 CONFIG_SYS_JFFS_CUSTOM_PART
1771 Define this to create an own partition. You have to provide a
1772 function struct part_info* jffs2_part_info(int part_num)
1774 If you define only one JFFS2 partition you may also want to
1775 #define CONFIG_SYS_JFFS_SINGLE_PART 1
1776 to disable the command chpart. This is the default when you
1777 have not defined a custom partition
1779 - FAT(File Allocation Table) filesystem write function support:
1782 Define this to enable support for saving memory data as a
1783 file in FAT formatted partition.
1785 This will also enable the command "fatwrite" enabling the
1786 user to write files to FAT.
1788 CBFS (Coreboot Filesystem) support
1791 Define this to enable support for reading from a Coreboot
1792 filesystem. Available commands are cbfsinit, cbfsinfo, cbfsls
1795 - FAT(File Allocation Table) filesystem cluster size:
1796 CONFIG_FS_FAT_MAX_CLUSTSIZE
1798 Define the max cluster size for fat operations else
1799 a default value of 65536 will be defined.
1804 Define this to enable standard (PC-Style) keyboard
1808 Standard PC keyboard driver with US (is default) and
1809 GERMAN key layout (switch via environment 'keymap=de') support.
1810 Export function i8042_kbd_init, i8042_tstc and i8042_getc
1811 for cfb_console. Supports cursor blinking.
1814 Enables a Chrome OS keyboard using the CROS_EC interface.
1815 This uses CROS_EC to communicate with a second microcontroller
1816 which provides key scans on request.
1821 Define this to enable video support (for output to
1824 CONFIG_VIDEO_CT69000
1826 Enable Chips & Technologies 69000 Video chip
1828 CONFIG_VIDEO_SMI_LYNXEM
1829 Enable Silicon Motion SMI 712/710/810 Video chip. The
1830 video output is selected via environment 'videoout'
1831 (1 = LCD and 2 = CRT). If videoout is undefined, CRT is
1834 For the CT69000 and SMI_LYNXEM drivers, videomode is
1835 selected via environment 'videomode'. Two different ways
1837 - "videomode=num" 'num' is a standard LiLo mode numbers.
1838 Following standard modes are supported (* is default):
1840 Colors 640x480 800x600 1024x768 1152x864 1280x1024
1841 -------------+---------------------------------------------
1842 8 bits | 0x301* 0x303 0x305 0x161 0x307
1843 15 bits | 0x310 0x313 0x316 0x162 0x319
1844 16 bits | 0x311 0x314 0x317 0x163 0x31A
1845 24 bits | 0x312 0x315 0x318 ? 0x31B
1846 -------------+---------------------------------------------
1847 (i.e. setenv videomode 317; saveenv; reset;)
1849 - "videomode=bootargs" all the video parameters are parsed
1850 from the bootargs. (See drivers/video/videomodes.c)
1853 CONFIG_VIDEO_SED13806
1854 Enable Epson SED13806 driver. This driver supports 8bpp
1855 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP
1856 or CONFIG_VIDEO_SED13806_16BPP
1859 Enable the Freescale DIU video driver. Reference boards for
1860 SOCs that have a DIU should define this macro to enable DIU
1861 support, and should also define these other macros:
1867 CONFIG_VIDEO_SW_CURSOR
1868 CONFIG_VGA_AS_SINGLE_DEVICE
1870 CONFIG_VIDEO_BMP_LOGO
1872 The DIU driver will look for the 'video-mode' environment
1873 variable, and if defined, enable the DIU as a console during
1874 boot. See the documentation file README.video for a
1875 description of this variable.
1881 Define this to enable a custom keyboard support.
1882 This simply calls drv_keyboard_init() which must be
1883 defined in your board-specific files.
1884 The only board using this so far is RBC823.
1886 - LCD Support: CONFIG_LCD
1888 Define this to enable LCD support (for output to LCD
1889 display); also select one of the supported displays
1890 by defining one of these:
1894 HITACHI TX09D70VM1CCA, 3.5", 240x320.
1896 CONFIG_NEC_NL6448AC33:
1898 NEC NL6448AC33-18. Active, color, single scan.
1900 CONFIG_NEC_NL6448BC20
1902 NEC NL6448BC20-08. 6.5", 640x480.
1903 Active, color, single scan.
1905 CONFIG_NEC_NL6448BC33_54
1907 NEC NL6448BC33-54. 10.4", 640x480.
1908 Active, color, single scan.
1912 Sharp 320x240. Active, color, single scan.
1913 It isn't 16x9, and I am not sure what it is.
1915 CONFIG_SHARP_LQ64D341
1917 Sharp LQ64D341 display, 640x480.
1918 Active, color, single scan.
1922 HLD1045 display, 640x480.
1923 Active, color, single scan.
1927 Optrex CBL50840-2 NF-FW 99 22 M5
1929 Hitachi LMG6912RPFC-00T
1933 320x240. Black & white.
1935 Normally display is black on white background; define
1936 CONFIG_SYS_WHITE_ON_BLACK to get it inverted.
1938 CONFIG_LCD_ALIGNMENT
1940 Normally the LCD is page-aligned (typically 4KB). If this is
1941 defined then the LCD will be aligned to this value instead.
1942 For ARM it is sometimes useful to use MMU_SECTION_SIZE
1943 here, since it is cheaper to change data cache settings on
1944 a per-section basis.
1946 CONFIG_CONSOLE_SCROLL_LINES
1948 When the console need to be scrolled, this is the number of
1949 lines to scroll by. It defaults to 1. Increasing this makes
1950 the console jump but can help speed up operation when scrolling
1955 Sometimes, for example if the display is mounted in portrait
1956 mode or even if it's mounted landscape but rotated by 180degree,
1957 we need to rotate our content of the display relative to the
1958 framebuffer, so that user can read the messages which are
1960 Once CONFIG_LCD_ROTATION is defined, the lcd_console will be
1961 initialized with a given rotation from "vl_rot" out of
1962 "vidinfo_t" which is provided by the board specific code.
1963 The value for vl_rot is coded as following (matching to
1964 fbcon=rotate:<n> linux-kernel commandline):
1965 0 = no rotation respectively 0 degree
1966 1 = 90 degree rotation
1967 2 = 180 degree rotation
1968 3 = 270 degree rotation
1970 If CONFIG_LCD_ROTATION is not defined, the console will be
1971 initialized with 0degree rotation.
1975 Support drawing of RLE8-compressed bitmaps on the LCD.
1979 Enables an 'i2c edid' command which can read EDID
1980 information over I2C from an attached LCD display.
1982 - Splash Screen Support: CONFIG_SPLASH_SCREEN
1984 If this option is set, the environment is checked for
1985 a variable "splashimage". If found, the usual display
1986 of logo, copyright and system information on the LCD
1987 is suppressed and the BMP image at the address
1988 specified in "splashimage" is loaded instead. The
1989 console is redirected to the "nulldev", too. This
1990 allows for a "silent" boot where a splash screen is
1991 loaded very quickly after power-on.
1993 CONFIG_SPLASHIMAGE_GUARD
1995 If this option is set, then U-Boot will prevent the environment
1996 variable "splashimage" from being set to a problematic address
1997 (see README.displaying-bmps).
1998 This option is useful for targets where, due to alignment
1999 restrictions, an improperly aligned BMP image will cause a data
2000 abort. If you think you will not have problems with unaligned
2001 accesses (for example because your toolchain prevents them)
2002 there is no need to set this option.
2004 CONFIG_SPLASH_SCREEN_ALIGN
2006 If this option is set the splash image can be freely positioned
2007 on the screen. Environment variable "splashpos" specifies the
2008 position as "x,y". If a positive number is given it is used as
2009 number of pixel from left/top. If a negative number is given it
2010 is used as number of pixel from right/bottom. You can also
2011 specify 'm' for centering the image.
2014 setenv splashpos m,m
2015 => image at center of screen
2017 setenv splashpos 30,20
2018 => image at x = 30 and y = 20
2020 setenv splashpos -10,m
2021 => vertically centered image
2022 at x = dspWidth - bmpWidth - 9
2024 - Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP
2026 If this option is set, additionally to standard BMP
2027 images, gzipped BMP images can be displayed via the
2028 splashscreen support or the bmp command.
2030 - Run length encoded BMP image (RLE8) support: CONFIG_VIDEO_BMP_RLE8
2032 If this option is set, 8-bit RLE compressed BMP images
2033 can be displayed via the splashscreen support or the
2036 - Do compressing for memory range:
2039 If this option is set, it would use zlib deflate method
2040 to compress the specified memory at its best effort.
2042 - Compression support:
2045 Enabled by default to support gzip compressed images.
2049 If this option is set, support for bzip2 compressed
2050 images is included. If not, only uncompressed and gzip
2051 compressed images are supported.
2053 NOTE: the bzip2 algorithm requires a lot of RAM, so
2054 the malloc area (as defined by CONFIG_SYS_MALLOC_LEN) should
2059 If this option is set, support for lzma compressed
2062 Note: The LZMA algorithm adds between 2 and 4KB of code and it
2063 requires an amount of dynamic memory that is given by the
2066 (1846 + 768 << (lc + lp)) * sizeof(uint16)
2068 Where lc and lp stand for, respectively, Literal context bits
2069 and Literal pos bits.
2071 This value is upper-bounded by 14MB in the worst case. Anyway,
2072 for a ~4MB large kernel image, we have lc=3 and lp=0 for a
2073 total amount of (1846 + 768 << (3 + 0)) * 2 = ~41KB... that is
2074 a very small buffer.
2076 Use the lzmainfo tool to determinate the lc and lp values and
2077 then calculate the amount of needed dynamic memory (ensuring
2078 the appropriate CONFIG_SYS_MALLOC_LEN value).
2082 If this option is set, support for LZO compressed images
2088 The address of PHY on MII bus.
2090 CONFIG_PHY_CLOCK_FREQ (ppc4xx)
2092 The clock frequency of the MII bus
2096 If this option is set, support for speed/duplex
2097 detection of gigabit PHY is included.
2099 CONFIG_PHY_RESET_DELAY
2101 Some PHY like Intel LXT971A need extra delay after
2102 reset before any MII register access is possible.
2103 For such PHY, set this option to the usec delay
2104 required. (minimum 300usec for LXT971A)
2106 CONFIG_PHY_CMD_DELAY (ppc4xx)
2108 Some PHY like Intel LXT971A need extra delay after
2109 command issued before MII status register can be read
2114 Define a default value for the IP address to use for
2115 the default Ethernet interface, in case this is not
2116 determined through e.g. bootp.
2117 (Environment variable "ipaddr")
2119 - Server IP address:
2122 Defines a default value for the IP address of a TFTP
2123 server to contact when using the "tftboot" command.
2124 (Environment variable "serverip")
2126 CONFIG_KEEP_SERVERADDR
2128 Keeps the server's MAC address, in the env 'serveraddr'
2129 for passing to bootargs (like Linux's netconsole option)
2131 - Gateway IP address:
2134 Defines a default value for the IP address of the
2135 default router where packets to other networks are
2137 (Environment variable "gatewayip")
2142 Defines a default value for the subnet mask (or
2143 routing prefix) which is used to determine if an IP
2144 address belongs to the local subnet or needs to be
2145 forwarded through a router.
2146 (Environment variable "netmask")
2148 - Multicast TFTP Mode:
2151 Defines whether you want to support multicast TFTP as per
2152 rfc-2090; for example to work with atftp. Lets lots of targets
2153 tftp down the same boot image concurrently. Note: the Ethernet
2154 driver in use must provide a function: mcast() to join/leave a
2157 - BOOTP Recovery Mode:
2158 CONFIG_BOOTP_RANDOM_DELAY
2160 If you have many targets in a network that try to
2161 boot using BOOTP, you may want to avoid that all
2162 systems send out BOOTP requests at precisely the same
2163 moment (which would happen for instance at recovery
2164 from a power failure, when all systems will try to
2165 boot, thus flooding the BOOTP server. Defining
2166 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
2167 inserted before sending out BOOTP requests. The
2168 following delays are inserted then:
2170 1st BOOTP request: delay 0 ... 1 sec
2171 2nd BOOTP request: delay 0 ... 2 sec
2172 3rd BOOTP request: delay 0 ... 4 sec
2174 BOOTP requests: delay 0 ... 8 sec
2176 CONFIG_BOOTP_ID_CACHE_SIZE
2178 BOOTP packets are uniquely identified using a 32-bit ID. The
2179 server will copy the ID from client requests to responses and
2180 U-Boot will use this to determine if it is the destination of
2181 an incoming response. Some servers will check that addresses
2182 aren't in use before handing them out (usually using an ARP
2183 ping) and therefore take up to a few hundred milliseconds to
2184 respond. Network congestion may also influence the time it
2185 takes for a response to make it back to the client. If that
2186 time is too long, U-Boot will retransmit requests. In order
2187 to allow earlier responses to still be accepted after these
2188 retransmissions, U-Boot's BOOTP client keeps a small cache of
2189 IDs. The CONFIG_BOOTP_ID_CACHE_SIZE controls the size of this
2190 cache. The default is to keep IDs for up to four outstanding
2191 requests. Increasing this will allow U-Boot to accept offers
2192 from a BOOTP client in networks with unusually high latency.
2194 - DHCP Advanced Options:
2195 You can fine tune the DHCP functionality by defining
2196 CONFIG_BOOTP_* symbols:
2198 CONFIG_BOOTP_SUBNETMASK
2199 CONFIG_BOOTP_GATEWAY
2200 CONFIG_BOOTP_HOSTNAME
2201 CONFIG_BOOTP_NISDOMAIN
2202 CONFIG_BOOTP_BOOTPATH
2203 CONFIG_BOOTP_BOOTFILESIZE
2206 CONFIG_BOOTP_SEND_HOSTNAME
2207 CONFIG_BOOTP_NTPSERVER
2208 CONFIG_BOOTP_TIMEOFFSET
2209 CONFIG_BOOTP_VENDOREX
2210 CONFIG_BOOTP_MAY_FAIL
2212 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip
2213 environment variable, not the BOOTP server.
2215 CONFIG_BOOTP_MAY_FAIL - If the DHCP server is not found
2216 after the configured retry count, the call will fail
2217 instead of starting over. This can be used to fail over
2218 to Link-local IP address configuration if the DHCP server
2221 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS
2222 serverip from a DHCP server, it is possible that more
2223 than one DNS serverip is offered to the client.
2224 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS
2225 serverip will be stored in the additional environment
2226 variable "dnsip2". The first DNS serverip is always
2227 stored in the variable "dnsip", when CONFIG_BOOTP_DNS
2230 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable
2231 to do a dynamic update of a DNS server. To do this, they
2232 need the hostname of the DHCP requester.
2233 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content
2234 of the "hostname" environment variable is passed as
2235 option 12 to the DHCP server.
2237 CONFIG_BOOTP_DHCP_REQUEST_DELAY
2239 A 32bit value in microseconds for a delay between
2240 receiving a "DHCP Offer" and sending the "DHCP Request".
2241 This fixes a problem with certain DHCP servers that don't
2242 respond 100% of the time to a "DHCP request". E.g. On an
2243 AT91RM9200 processor running at 180MHz, this delay needed
2244 to be *at least* 15,000 usec before a Windows Server 2003
2245 DHCP server would reply 100% of the time. I recommend at
2246 least 50,000 usec to be safe. The alternative is to hope
2247 that one of the retries will be successful but note that
2248 the DHCP timeout and retry process takes a longer than
2251 - Link-local IP address negotiation:
2252 Negotiate with other link-local clients on the local network
2253 for an address that doesn't require explicit configuration.
2254 This is especially useful if a DHCP server cannot be guaranteed
2255 to exist in all environments that the device must operate.
2257 See doc/README.link-local for more information.
2260 CONFIG_CDP_DEVICE_ID
2262 The device id used in CDP trigger frames.
2264 CONFIG_CDP_DEVICE_ID_PREFIX
2266 A two character string which is prefixed to the MAC address
2271 A printf format string which contains the ascii name of
2272 the port. Normally is set to "eth%d" which sets
2273 eth0 for the first Ethernet, eth1 for the second etc.
2275 CONFIG_CDP_CAPABILITIES
2277 A 32bit integer which indicates the device capabilities;
2278 0x00000010 for a normal host which does not forwards.
2282 An ascii string containing the version of the software.
2286 An ascii string containing the name of the platform.
2290 A 32bit integer sent on the trigger.
2292 CONFIG_CDP_POWER_CONSUMPTION
2294 A 16bit integer containing the power consumption of the
2295 device in .1 of milliwatts.
2297 CONFIG_CDP_APPLIANCE_VLAN_TYPE
2299 A byte containing the id of the VLAN.
2301 - Status LED: CONFIG_STATUS_LED
2303 Several configurations allow to display the current
2304 status using a LED. For instance, the LED will blink
2305 fast while running U-Boot code, stop blinking as
2306 soon as a reply to a BOOTP request was received, and
2307 start blinking slow once the Linux kernel is running
2308 (supported by a status LED driver in the Linux
2309 kernel). Defining CONFIG_STATUS_LED enables this
2315 The status LED can be connected to a GPIO pin.
2316 In such cases, the gpio_led driver can be used as a
2317 status LED backend implementation. Define CONFIG_GPIO_LED
2318 to include the gpio_led driver in the U-Boot binary.
2320 CONFIG_GPIO_LED_INVERTED_TABLE
2321 Some GPIO connected LEDs may have inverted polarity in which
2322 case the GPIO high value corresponds to LED off state and
2323 GPIO low value corresponds to LED on state.
2324 In such cases CONFIG_GPIO_LED_INVERTED_TABLE may be defined
2325 with a list of GPIO LEDs that have inverted polarity.
2327 - CAN Support: CONFIG_CAN_DRIVER
2329 Defining CONFIG_CAN_DRIVER enables CAN driver support
2330 on those systems that support this (optional)
2331 feature, like the TQM8xxL modules.
2333 - I2C Support: CONFIG_SYS_I2C
2335 This enable the NEW i2c subsystem, and will allow you to use
2336 i2c commands at the u-boot command line (as long as you set
2337 CONFIG_CMD_I2C in CONFIG_COMMANDS) and communicate with i2c
2338 based realtime clock chips or other i2c devices. See
2339 common/cmd_i2c.c for a description of the command line
2342 ported i2c driver to the new framework:
2343 - drivers/i2c/soft_i2c.c:
2344 - activate first bus with CONFIG_SYS_I2C_SOFT define
2345 CONFIG_SYS_I2C_SOFT_SPEED and CONFIG_SYS_I2C_SOFT_SLAVE
2346 for defining speed and slave address
2347 - activate second bus with I2C_SOFT_DECLARATIONS2 define
2348 CONFIG_SYS_I2C_SOFT_SPEED_2 and CONFIG_SYS_I2C_SOFT_SLAVE_2
2349 for defining speed and slave address
2350 - activate third bus with I2C_SOFT_DECLARATIONS3 define
2351 CONFIG_SYS_I2C_SOFT_SPEED_3 and CONFIG_SYS_I2C_SOFT_SLAVE_3
2352 for defining speed and slave address
2353 - activate fourth bus with I2C_SOFT_DECLARATIONS4 define
2354 CONFIG_SYS_I2C_SOFT_SPEED_4 and CONFIG_SYS_I2C_SOFT_SLAVE_4
2355 for defining speed and slave address
2357 - drivers/i2c/fsl_i2c.c:
2358 - activate i2c driver with CONFIG_SYS_I2C_FSL
2359 define CONFIG_SYS_FSL_I2C_OFFSET for setting the register
2360 offset CONFIG_SYS_FSL_I2C_SPEED for the i2c speed and
2361 CONFIG_SYS_FSL_I2C_SLAVE for the slave addr of the first
2363 - If your board supports a second fsl i2c bus, define
2364 CONFIG_SYS_FSL_I2C2_OFFSET for the register offset
2365 CONFIG_SYS_FSL_I2C2_SPEED for the speed and
2366 CONFIG_SYS_FSL_I2C2_SLAVE for the slave address of the
2369 - drivers/i2c/tegra_i2c.c:
2370 - activate this driver with CONFIG_SYS_I2C_TEGRA
2371 - This driver adds 4 i2c buses with a fix speed from
2372 100000 and the slave addr 0!
2374 - drivers/i2c/ppc4xx_i2c.c
2375 - activate this driver with CONFIG_SYS_I2C_PPC4XX
2376 - CONFIG_SYS_I2C_PPC4XX_CH0 activate hardware channel 0
2377 - CONFIG_SYS_I2C_PPC4XX_CH1 activate hardware channel 1
2379 - drivers/i2c/i2c_mxc.c
2380 - activate this driver with CONFIG_SYS_I2C_MXC
2381 - define speed for bus 1 with CONFIG_SYS_MXC_I2C1_SPEED
2382 - define slave for bus 1 with CONFIG_SYS_MXC_I2C1_SLAVE
2383 - define speed for bus 2 with CONFIG_SYS_MXC_I2C2_SPEED
2384 - define slave for bus 2 with CONFIG_SYS_MXC_I2C2_SLAVE
2385 - define speed for bus 3 with CONFIG_SYS_MXC_I2C3_SPEED
2386 - define slave for bus 3 with CONFIG_SYS_MXC_I2C3_SLAVE
2387 If those defines are not set, default value is 100000
2388 for speed, and 0 for slave.
2389 - enable bus 3 with CONFIG_SYS_I2C_MXC_I2C3
2390 - enable bus 4 with CONFIG_SYS_I2C_MXC_I2C4
2392 - drivers/i2c/rcar_i2c.c:
2393 - activate this driver with CONFIG_SYS_I2C_RCAR
2394 - This driver adds 4 i2c buses
2396 - CONFIG_SYS_RCAR_I2C0_BASE for setting the register channel 0
2397 - CONFIG_SYS_RCAR_I2C0_SPEED for for the speed channel 0
2398 - CONFIG_SYS_RCAR_I2C1_BASE for setting the register channel 1
2399 - CONFIG_SYS_RCAR_I2C1_SPEED for for the speed channel 1
2400 - CONFIG_SYS_RCAR_I2C2_BASE for setting the register channel 2
2401 - CONFIG_SYS_RCAR_I2C2_SPEED for for the speed channel 2
2402 - CONFIG_SYS_RCAR_I2C3_BASE for setting the register channel 3
2403 - CONFIG_SYS_RCAR_I2C3_SPEED for for the speed channel 3
2404 - CONFIF_SYS_RCAR_I2C_NUM_CONTROLLERS for number of i2c buses
2406 - drivers/i2c/sh_i2c.c:
2407 - activate this driver with CONFIG_SYS_I2C_SH
2408 - This driver adds from 2 to 5 i2c buses
2410 - CONFIG_SYS_I2C_SH_BASE0 for setting the register channel 0
2411 - CONFIG_SYS_I2C_SH_SPEED0 for for the speed channel 0
2412 - CONFIG_SYS_I2C_SH_BASE1 for setting the register channel 1
2413 - CONFIG_SYS_I2C_SH_SPEED1 for for the speed channel 1
2414 - CONFIG_SYS_I2C_SH_BASE2 for setting the register channel 2
2415 - CONFIG_SYS_I2C_SH_SPEED2 for for the speed channel 2
2416 - CONFIG_SYS_I2C_SH_BASE3 for setting the register channel 3
2417 - CONFIG_SYS_I2C_SH_SPEED3 for for the speed channel 3
2418 - CONFIG_SYS_I2C_SH_BASE4 for setting the register channel 4
2419 - CONFIG_SYS_I2C_SH_SPEED4 for for the speed channel 4
2420 - CONFIG_SYS_I2C_SH_BASE5 for setting the register channel 5
2421 - CONFIG_SYS_I2C_SH_SPEED5 for for the speed channel 5
2422 - CONFIG_SYS_I2C_SH_NUM_CONTROLLERS for number of i2c buses
2424 - drivers/i2c/omap24xx_i2c.c
2425 - activate this driver with CONFIG_SYS_I2C_OMAP24XX
2426 - CONFIG_SYS_OMAP24_I2C_SPEED speed channel 0
2427 - CONFIG_SYS_OMAP24_I2C_SLAVE slave addr channel 0
2428 - CONFIG_SYS_OMAP24_I2C_SPEED1 speed channel 1
2429 - CONFIG_SYS_OMAP24_I2C_SLAVE1 slave addr channel 1
2430 - CONFIG_SYS_OMAP24_I2C_SPEED2 speed channel 2
2431 - CONFIG_SYS_OMAP24_I2C_SLAVE2 slave addr channel 2
2432 - CONFIG_SYS_OMAP24_I2C_SPEED3 speed channel 3
2433 - CONFIG_SYS_OMAP24_I2C_SLAVE3 slave addr channel 3
2434 - CONFIG_SYS_OMAP24_I2C_SPEED4 speed channel 4
2435 - CONFIG_SYS_OMAP24_I2C_SLAVE4 slave addr channel 4
2437 - drivers/i2c/zynq_i2c.c
2438 - activate this driver with CONFIG_SYS_I2C_ZYNQ
2439 - set CONFIG_SYS_I2C_ZYNQ_SPEED for speed setting
2440 - set CONFIG_SYS_I2C_ZYNQ_SLAVE for slave addr
2442 - drivers/i2c/s3c24x0_i2c.c:
2443 - activate this driver with CONFIG_SYS_I2C_S3C24X0
2444 - This driver adds i2c buses (11 for Exynos5250, Exynos5420
2445 9 i2c buses for Exynos4 and 1 for S3C24X0 SoCs from Samsung)
2446 with a fix speed from 100000 and the slave addr 0!
2448 - drivers/i2c/ihs_i2c.c
2449 - activate this driver with CONFIG_SYS_I2C_IHS
2450 - CONFIG_SYS_I2C_IHS_CH0 activate hardware channel 0
2451 - CONFIG_SYS_I2C_IHS_SPEED_0 speed channel 0
2452 - CONFIG_SYS_I2C_IHS_SLAVE_0 slave addr channel 0
2453 - CONFIG_SYS_I2C_IHS_CH1 activate hardware channel 1
2454 - CONFIG_SYS_I2C_IHS_SPEED_1 speed channel 1
2455 - CONFIG_SYS_I2C_IHS_SLAVE_1 slave addr channel 1
2456 - CONFIG_SYS_I2C_IHS_CH2 activate hardware channel 2
2457 - CONFIG_SYS_I2C_IHS_SPEED_2 speed channel 2
2458 - CONFIG_SYS_I2C_IHS_SLAVE_2 slave addr channel 2
2459 - CONFIG_SYS_I2C_IHS_CH3 activate hardware channel 3
2460 - CONFIG_SYS_I2C_IHS_SPEED_3 speed channel 3
2461 - CONFIG_SYS_I2C_IHS_SLAVE_3 slave addr channel 3
2465 CONFIG_SYS_NUM_I2C_BUSES
2466 Hold the number of i2c buses you want to use. If you
2467 don't use/have i2c muxes on your i2c bus, this
2468 is equal to CONFIG_SYS_NUM_I2C_ADAPTERS, and you can
2471 CONFIG_SYS_I2C_DIRECT_BUS
2472 define this, if you don't use i2c muxes on your hardware.
2473 if CONFIG_SYS_I2C_MAX_HOPS is not defined or == 0 you can
2476 CONFIG_SYS_I2C_MAX_HOPS
2477 define how many muxes are maximal consecutively connected
2478 on one i2c bus. If you not use i2c muxes, omit this
2481 CONFIG_SYS_I2C_BUSES
2482 hold a list of buses you want to use, only used if
2483 CONFIG_SYS_I2C_DIRECT_BUS is not defined, for example
2484 a board with CONFIG_SYS_I2C_MAX_HOPS = 1 and
2485 CONFIG_SYS_NUM_I2C_BUSES = 9:
2487 CONFIG_SYS_I2C_BUSES {{0, {I2C_NULL_HOP}}, \
2488 {0, {{I2C_MUX_PCA9547, 0x70, 1}}}, \
2489 {0, {{I2C_MUX_PCA9547, 0x70, 2}}}, \
2490 {0, {{I2C_MUX_PCA9547, 0x70, 3}}}, \
2491 {0, {{I2C_MUX_PCA9547, 0x70, 4}}}, \
2492 {0, {{I2C_MUX_PCA9547, 0x70, 5}}}, \
2493 {1, {I2C_NULL_HOP}}, \
2494 {1, {{I2C_MUX_PCA9544, 0x72, 1}}}, \
2495 {1, {{I2C_MUX_PCA9544, 0x72, 2}}}, \
2499 bus 0 on adapter 0 without a mux
2500 bus 1 on adapter 0 with a PCA9547 on address 0x70 port 1
2501 bus 2 on adapter 0 with a PCA9547 on address 0x70 port 2
2502 bus 3 on adapter 0 with a PCA9547 on address 0x70 port 3
2503 bus 4 on adapter 0 with a PCA9547 on address 0x70 port 4
2504 bus 5 on adapter 0 with a PCA9547 on address 0x70 port 5
2505 bus 6 on adapter 1 without a mux
2506 bus 7 on adapter 1 with a PCA9544 on address 0x72 port 1
2507 bus 8 on adapter 1 with a PCA9544 on address 0x72 port 2
2509 If you do not have i2c muxes on your board, omit this define.
2511 - Legacy I2C Support: CONFIG_HARD_I2C
2513 NOTE: It is intended to move drivers to CONFIG_SYS_I2C which
2514 provides the following compelling advantages:
2516 - more than one i2c adapter is usable
2517 - approved multibus support
2518 - better i2c mux support
2520 ** Please consider updating your I2C driver now. **
2522 These enable legacy I2C serial bus commands. Defining
2523 CONFIG_HARD_I2C will include the appropriate I2C driver
2524 for the selected CPU.
2526 This will allow you to use i2c commands at the u-boot
2527 command line (as long as you set CONFIG_CMD_I2C in
2528 CONFIG_COMMANDS) and communicate with i2c based realtime
2529 clock chips. See common/cmd_i2c.c for a description of the
2530 command line interface.
2532 CONFIG_HARD_I2C selects a hardware I2C controller.
2534 There are several other quantities that must also be
2535 defined when you define CONFIG_HARD_I2C.
2537 In both cases you will need to define CONFIG_SYS_I2C_SPEED
2538 to be the frequency (in Hz) at which you wish your i2c bus
2539 to run and CONFIG_SYS_I2C_SLAVE to be the address of this node (ie
2540 the CPU's i2c node address).
2542 Now, the u-boot i2c code for the mpc8xx
2543 (arch/powerpc/cpu/mpc8xx/i2c.c) sets the CPU up as a master node
2544 and so its address should therefore be cleared to 0 (See,
2545 eg, MPC823e User's Manual p.16-473). So, set
2546 CONFIG_SYS_I2C_SLAVE to 0.
2548 CONFIG_SYS_I2C_INIT_MPC5XXX
2550 When a board is reset during an i2c bus transfer
2551 chips might think that the current transfer is still
2552 in progress. Reset the slave devices by sending start
2553 commands until the slave device responds.
2555 That's all that's required for CONFIG_HARD_I2C.
2557 If you use the software i2c interface (CONFIG_SYS_I2C_SOFT)
2558 then the following macros need to be defined (examples are
2559 from include/configs/lwmon.h):
2563 (Optional). Any commands necessary to enable the I2C
2564 controller or configure ports.
2566 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
2570 (Only for MPC8260 CPU). The I/O port to use (the code
2571 assumes both bits are on the same port). Valid values
2572 are 0..3 for ports A..D.
2576 The code necessary to make the I2C data line active
2577 (driven). If the data line is open collector, this
2580 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
2584 The code necessary to make the I2C data line tri-stated
2585 (inactive). If the data line is open collector, this
2588 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
2592 Code that returns true if the I2C data line is high,
2595 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
2599 If <bit> is true, sets the I2C data line high. If it
2600 is false, it clears it (low).
2602 eg: #define I2C_SDA(bit) \
2603 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
2604 else immr->im_cpm.cp_pbdat &= ~PB_SDA
2608 If <bit> is true, sets the I2C clock line high. If it
2609 is false, it clears it (low).
2611 eg: #define I2C_SCL(bit) \
2612 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
2613 else immr->im_cpm.cp_pbdat &= ~PB_SCL
2617 This delay is invoked four times per clock cycle so this
2618 controls the rate of data transfer. The data rate thus
2619 is 1 / (I2C_DELAY * 4). Often defined to be something
2622 #define I2C_DELAY udelay(2)
2624 CONFIG_SOFT_I2C_GPIO_SCL / CONFIG_SOFT_I2C_GPIO_SDA
2626 If your arch supports the generic GPIO framework (asm/gpio.h),
2627 then you may alternatively define the two GPIOs that are to be
2628 used as SCL / SDA. Any of the previous I2C_xxx macros will
2629 have GPIO-based defaults assigned to them as appropriate.
2631 You should define these to the GPIO value as given directly to
2632 the generic GPIO functions.
2634 CONFIG_SYS_I2C_INIT_BOARD
2636 When a board is reset during an i2c bus transfer
2637 chips might think that the current transfer is still
2638 in progress. On some boards it is possible to access
2639 the i2c SCLK line directly, either by using the
2640 processor pin as a GPIO or by having a second pin
2641 connected to the bus. If this option is defined a
2642 custom i2c_init_board() routine in boards/xxx/board.c
2643 is run early in the boot sequence.
2645 CONFIG_SYS_I2C_BOARD_LATE_INIT
2647 An alternative to CONFIG_SYS_I2C_INIT_BOARD. If this option is
2648 defined a custom i2c_board_late_init() routine in
2649 boards/xxx/board.c is run AFTER the operations in i2c_init()
2650 is completed. This callpoint can be used to unreset i2c bus
2651 using CPU i2c controller register accesses for CPUs whose i2c
2652 controller provide such a method. It is called at the end of
2653 i2c_init() to allow i2c_init operations to setup the i2c bus
2654 controller on the CPU (e.g. setting bus speed & slave address).
2656 CONFIG_I2CFAST (PPC405GP|PPC405EP only)
2658 This option enables configuration of bi_iic_fast[] flags
2659 in u-boot bd_info structure based on u-boot environment
2660 variable "i2cfast". (see also i2cfast)
2662 CONFIG_I2C_MULTI_BUS
2664 This option allows the use of multiple I2C buses, each of which
2665 must have a controller. At any point in time, only one bus is
2666 active. To switch to a different bus, use the 'i2c dev' command.
2667 Note that bus numbering is zero-based.
2669 CONFIG_SYS_I2C_NOPROBES
2671 This option specifies a list of I2C devices that will be skipped
2672 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS
2673 is set, specify a list of bus-device pairs. Otherwise, specify
2674 a 1D array of device addresses
2677 #undef CONFIG_I2C_MULTI_BUS
2678 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68}
2680 will skip addresses 0x50 and 0x68 on a board with one I2C bus
2682 #define CONFIG_I2C_MULTI_BUS
2683 #define CONFIG_SYS_I2C_MULTI_NOPROBES {{0,0x50},{0,0x68},{1,0x54}}
2685 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1
2687 CONFIG_SYS_SPD_BUS_NUM
2689 If defined, then this indicates the I2C bus number for DDR SPD.
2690 If not defined, then U-Boot assumes that SPD is on I2C bus 0.
2692 CONFIG_SYS_RTC_BUS_NUM
2694 If defined, then this indicates the I2C bus number for the RTC.
2695 If not defined, then U-Boot assumes that RTC is on I2C bus 0.
2697 CONFIG_SYS_DTT_BUS_NUM
2699 If defined, then this indicates the I2C bus number for the DTT.
2700 If not defined, then U-Boot assumes that DTT is on I2C bus 0.
2702 CONFIG_SYS_I2C_DTT_ADDR:
2704 If defined, specifies the I2C address of the DTT device.
2705 If not defined, then U-Boot uses predefined value for
2706 specified DTT device.
2708 CONFIG_SOFT_I2C_READ_REPEATED_START
2710 defining this will force the i2c_read() function in
2711 the soft_i2c driver to perform an I2C repeated start
2712 between writing the address pointer and reading the
2713 data. If this define is omitted the default behaviour
2714 of doing a stop-start sequence will be used. Most I2C
2715 devices can use either method, but some require one or
2718 - SPI Support: CONFIG_SPI
2720 Enables SPI driver (so far only tested with
2721 SPI EEPROM, also an instance works with Crystal A/D and
2722 D/As on the SACSng board)
2726 Enables the driver for SPI controller on SuperH. Currently
2727 only SH7757 is supported.
2731 Enables extended (16-bit) SPI EEPROM addressing.
2732 (symmetrical to CONFIG_I2C_X)
2736 Enables a software (bit-bang) SPI driver rather than
2737 using hardware support. This is a general purpose
2738 driver that only requires three general I/O port pins
2739 (two outputs, one input) to function. If this is
2740 defined, the board configuration must define several
2741 SPI configuration items (port pins to use, etc). For
2742 an example, see include/configs/sacsng.h.
2746 Enables a hardware SPI driver for general-purpose reads
2747 and writes. As with CONFIG_SOFT_SPI, the board configuration
2748 must define a list of chip-select function pointers.
2749 Currently supported on some MPC8xxx processors. For an
2750 example, see include/configs/mpc8349emds.h.
2754 Enables the driver for the SPI controllers on i.MX and MXC
2755 SoCs. Currently i.MX31/35/51 are supported.
2757 CONFIG_SYS_SPI_MXC_WAIT
2758 Timeout for waiting until spi transfer completed.
2759 default: (CONFIG_SYS_HZ/100) /* 10 ms */
2761 - FPGA Support: CONFIG_FPGA
2763 Enables FPGA subsystem.
2765 CONFIG_FPGA_<vendor>
2767 Enables support for specific chip vendors.
2770 CONFIG_FPGA_<family>
2772 Enables support for FPGA family.
2773 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX)
2777 Specify the number of FPGA devices to support.
2779 CONFIG_CMD_FPGA_LOADMK
2781 Enable support for fpga loadmk command
2783 CONFIG_CMD_FPGA_LOADP
2785 Enable support for fpga loadp command - load partial bitstream
2787 CONFIG_CMD_FPGA_LOADBP
2789 Enable support for fpga loadbp command - load partial bitstream
2792 CONFIG_SYS_FPGA_PROG_FEEDBACK
2794 Enable printing of hash marks during FPGA configuration.
2796 CONFIG_SYS_FPGA_CHECK_BUSY
2798 Enable checks on FPGA configuration interface busy
2799 status by the configuration function. This option
2800 will require a board or device specific function to
2805 If defined, a function that provides delays in the FPGA
2806 configuration driver.
2808 CONFIG_SYS_FPGA_CHECK_CTRLC
2809 Allow Control-C to interrupt FPGA configuration
2811 CONFIG_SYS_FPGA_CHECK_ERROR
2813 Check for configuration errors during FPGA bitfile
2814 loading. For example, abort during Virtex II
2815 configuration if the INIT_B line goes low (which
2816 indicated a CRC error).
2818 CONFIG_SYS_FPGA_WAIT_INIT
2820 Maximum time to wait for the INIT_B line to de-assert
2821 after PROB_B has been de-asserted during a Virtex II
2822 FPGA configuration sequence. The default time is 500
2825 CONFIG_SYS_FPGA_WAIT_BUSY
2827 Maximum time to wait for BUSY to de-assert during
2828 Virtex II FPGA configuration. The default is 5 ms.
2830 CONFIG_SYS_FPGA_WAIT_CONFIG
2832 Time to wait after FPGA configuration. The default is
2835 - Configuration Management:
2838 Some SoCs need special image types (e.g. U-Boot binary
2839 with a special header) as build targets. By defining
2840 CONFIG_BUILD_TARGET in the SoC / board header, this
2841 special image will be automatically built upon calling
2846 If defined, this string will be added to the U-Boot
2847 version information (U_BOOT_VERSION)
2849 - Vendor Parameter Protection:
2851 U-Boot considers the values of the environment
2852 variables "serial#" (Board Serial Number) and
2853 "ethaddr" (Ethernet Address) to be parameters that
2854 are set once by the board vendor / manufacturer, and
2855 protects these variables from casual modification by
2856 the user. Once set, these variables are read-only,
2857 and write or delete attempts are rejected. You can
2858 change this behaviour:
2860 If CONFIG_ENV_OVERWRITE is #defined in your config
2861 file, the write protection for vendor parameters is
2862 completely disabled. Anybody can change or delete
2865 Alternatively, if you define _both_ an ethaddr in the
2866 default env _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
2867 Ethernet address is installed in the environment,
2868 which can be changed exactly ONCE by the user. [The
2869 serial# is unaffected by this, i. e. it remains
2872 The same can be accomplished in a more flexible way
2873 for any variable by configuring the type of access
2874 to allow for those variables in the ".flags" variable
2875 or define CONFIG_ENV_FLAGS_LIST_STATIC.
2880 Define this variable to enable the reservation of
2881 "protected RAM", i. e. RAM which is not overwritten
2882 by U-Boot. Define CONFIG_PRAM to hold the number of
2883 kB you want to reserve for pRAM. You can overwrite
2884 this default value by defining an environment
2885 variable "pram" to the number of kB you want to
2886 reserve. Note that the board info structure will
2887 still show the full amount of RAM. If pRAM is
2888 reserved, a new environment variable "mem" will
2889 automatically be defined to hold the amount of
2890 remaining RAM in a form that can be passed as boot
2891 argument to Linux, for instance like that:
2893 setenv bootargs ... mem=\${mem}
2896 This way you can tell Linux not to use this memory,
2897 either, which results in a memory region that will
2898 not be affected by reboots.
2900 *WARNING* If your board configuration uses automatic
2901 detection of the RAM size, you must make sure that
2902 this memory test is non-destructive. So far, the
2903 following board configurations are known to be
2906 IVMS8, IVML24, SPD8xx, TQM8xxL,
2907 HERMES, IP860, RPXlite, LWMON,
2910 - Access to physical memory region (> 4GB)
2911 Some basic support is provided for operations on memory not
2912 normally accessible to U-Boot - e.g. some architectures
2913 support access to more than 4GB of memory on 32-bit
2914 machines using physical address extension or similar.
2915 Define CONFIG_PHYSMEM to access this basic support, which
2916 currently only supports clearing the memory.
2921 Define this variable to stop the system in case of a
2922 fatal error, so that you have to reset it manually.
2923 This is probably NOT a good idea for an embedded
2924 system where you want the system to reboot
2925 automatically as fast as possible, but it may be
2926 useful during development since you can try to debug
2927 the conditions that lead to the situation.
2929 CONFIG_NET_RETRY_COUNT
2931 This variable defines the number of retries for
2932 network operations like ARP, RARP, TFTP, or BOOTP
2933 before giving up the operation. If not defined, a
2934 default value of 5 is used.
2938 Timeout waiting for an ARP reply in milliseconds.
2942 Timeout in milliseconds used in NFS protocol.
2943 If you encounter "ERROR: Cannot umount" in nfs command,
2944 try longer timeout such as
2945 #define CONFIG_NFS_TIMEOUT 10000UL
2947 - Command Interpreter:
2948 CONFIG_AUTO_COMPLETE
2950 Enable auto completion of commands using TAB.
2952 CONFIG_SYS_PROMPT_HUSH_PS2
2954 This defines the secondary prompt string, which is
2955 printed when the command interpreter needs more input
2956 to complete a command. Usually "> ".
2960 In the current implementation, the local variables
2961 space and global environment variables space are
2962 separated. Local variables are those you define by
2963 simply typing `name=value'. To access a local
2964 variable later on, you have write `$name' or
2965 `${name}'; to execute the contents of a variable
2966 directly type `$name' at the command prompt.
2968 Global environment variables are those you use
2969 setenv/printenv to work with. To run a command stored
2970 in such a variable, you need to use the run command,
2971 and you must not use the '$' sign to access them.
2973 To store commands and special characters in a
2974 variable, please use double quotation marks
2975 surrounding the whole text of the variable, instead
2976 of the backslashes before semicolons and special
2979 - Command Line Editing and History:
2980 CONFIG_CMDLINE_EDITING
2982 Enable editing and History functions for interactive
2983 command line input operations
2985 - Default Environment:
2986 CONFIG_EXTRA_ENV_SETTINGS
2988 Define this to contain any number of null terminated
2989 strings (variable = value pairs) that will be part of
2990 the default environment compiled into the boot image.
2992 For example, place something like this in your
2993 board's config file:
2995 #define CONFIG_EXTRA_ENV_SETTINGS \
2999 Warning: This method is based on knowledge about the
3000 internal format how the environment is stored by the
3001 U-Boot code. This is NOT an official, exported
3002 interface! Although it is unlikely that this format
3003 will change soon, there is no guarantee either.
3004 You better know what you are doing here.
3006 Note: overly (ab)use of the default environment is
3007 discouraged. Make sure to check other ways to preset
3008 the environment like the "source" command or the
3011 CONFIG_ENV_VARS_UBOOT_CONFIG
3013 Define this in order to add variables describing the
3014 U-Boot build configuration to the default environment.
3015 These will be named arch, cpu, board, vendor, and soc.
3017 Enabling this option will cause the following to be defined:
3025 CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG
3027 Define this in order to add variables describing certain
3028 run-time determined information about the hardware to the
3029 environment. These will be named board_name, board_rev.
3031 CONFIG_DELAY_ENVIRONMENT
3033 Normally the environment is loaded when the board is
3034 initialised so that it is available to U-Boot. This inhibits
3035 that so that the environment is not available until
3036 explicitly loaded later by U-Boot code. With CONFIG_OF_CONTROL
3037 this is instead controlled by the value of
3038 /config/load-environment.
3040 - Parallel Flash support:
3043 Traditionally U-boot was run on systems with parallel NOR
3044 flash. This option is used to disable support for parallel NOR
3045 flash. This option should be defined if the board does not have
3048 If this option is not defined one of the generic flash drivers
3049 (e.g. CONFIG_FLASH_CFI_DRIVER or CONFIG_ST_SMI) must be
3050 selected or the board must provide an implementation of the
3051 flash API (see include/flash.h).
3053 - DataFlash Support:
3054 CONFIG_HAS_DATAFLASH
3056 Defining this option enables DataFlash features and
3057 allows to read/write in Dataflash via the standard
3060 - Serial Flash support
3063 Defining this option enables SPI flash commands
3064 'sf probe/read/write/erase/update'.
3066 Usage requires an initial 'probe' to define the serial
3067 flash parameters, followed by read/write/erase/update
3070 The following defaults may be provided by the platform
3071 to handle the common case when only a single serial
3072 flash is present on the system.
3074 CONFIG_SF_DEFAULT_BUS Bus identifier
3075 CONFIG_SF_DEFAULT_CS Chip-select
3076 CONFIG_SF_DEFAULT_MODE (see include/spi.h)
3077 CONFIG_SF_DEFAULT_SPEED in Hz
3081 Define this option to include a destructive SPI flash
3084 CONFIG_SPI_FLASH_BAR Ban/Extended Addr Reg
3086 Define this option to use the Bank addr/Extended addr
3087 support on SPI flashes which has size > 16Mbytes.
3089 CONFIG_SF_DUAL_FLASH Dual flash memories
3091 Define this option to use dual flash support where two flash
3092 memories can be connected with a given cs line.
3093 Currently Xilinx Zynq qspi supports these type of connections.
3095 - SystemACE Support:
3098 Adding this option adds support for Xilinx SystemACE
3099 chips attached via some sort of local bus. The address
3100 of the chip must also be defined in the
3101 CONFIG_SYS_SYSTEMACE_BASE macro. For example:
3103 #define CONFIG_SYSTEMACE
3104 #define CONFIG_SYS_SYSTEMACE_BASE 0xf0000000
3106 When SystemACE support is added, the "ace" device type
3107 becomes available to the fat commands, i.e. fatls.
3109 - TFTP Fixed UDP Port:
3112 If this is defined, the environment variable tftpsrcp
3113 is used to supply the TFTP UDP source port value.
3114 If tftpsrcp isn't defined, the normal pseudo-random port
3115 number generator is used.
3117 Also, the environment variable tftpdstp is used to supply
3118 the TFTP UDP destination port value. If tftpdstp isn't
3119 defined, the normal port 69 is used.
3121 The purpose for tftpsrcp is to allow a TFTP server to
3122 blindly start the TFTP transfer using the pre-configured
3123 target IP address and UDP port. This has the effect of
3124 "punching through" the (Windows XP) firewall, allowing
3125 the remainder of the TFTP transfer to proceed normally.
3126 A better solution is to properly configure the firewall,
3127 but sometimes that is not allowed.
3132 This enables a generic 'hash' command which can produce
3133 hashes / digests from a few algorithms (e.g. SHA1, SHA256).
3137 Enable the hash verify command (hash -v). This adds to code
3140 CONFIG_SHA1 - This option enables support of hashing using SHA1
3141 algorithm. The hash is calculated in software.
3142 CONFIG_SHA256 - This option enables support of hashing using
3143 SHA256 algorithm. The hash is calculated in software.
3144 CONFIG_SHA_HW_ACCEL - This option enables hardware acceleration
3145 for SHA1/SHA256 hashing.
3146 This affects the 'hash' command and also the
3147 hash_lookup_algo() function.
3148 CONFIG_SHA_PROG_HW_ACCEL - This option enables
3149 hardware-acceleration for SHA1/SHA256 progressive hashing.
3150 Data can be streamed in a block at a time and the hashing
3151 is performed in hardware.
3153 Note: There is also a sha1sum command, which should perhaps
3154 be deprecated in favour of 'hash sha1'.
3156 - Freescale i.MX specific commands:
3157 CONFIG_CMD_HDMIDETECT
3158 This enables 'hdmidet' command which returns true if an
3159 HDMI monitor is detected. This command is i.MX 6 specific.
3162 This enables the 'bmode' (bootmode) command for forcing
3163 a boot from specific media.
3165 This is useful for forcing the ROM's usb downloader to
3166 activate upon a watchdog reset which is nice when iterating
3167 on U-Boot. Using the reset button or running bmode normal
3168 will set it back to normal. This command currently
3169 supports i.MX53 and i.MX6.
3174 This enables the RSA algorithm used for FIT image verification
3175 in U-Boot. See doc/uImage.FIT/signature.txt for more information.
3177 The Modular Exponentiation algorithm in RSA is implemented using
3178 driver model. So CONFIG_DM needs to be enabled by default for this
3179 library to function.
3181 The signing part is build into mkimage regardless of this
3182 option. The software based modular exponentiation is built into
3183 mkimage irrespective of this option.
3185 - bootcount support:
3186 CONFIG_BOOTCOUNT_LIMIT
3188 This enables the bootcounter support, see:
3189 http://www.denx.de/wiki/DULG/UBootBootCountLimit
3192 enable special bootcounter support on at91sam9xe based boards.
3194 enable special bootcounter support on blackfin based boards.
3196 enable special bootcounter support on da850 based boards.
3197 CONFIG_BOOTCOUNT_RAM
3198 enable support for the bootcounter in RAM
3199 CONFIG_BOOTCOUNT_I2C
3200 enable support for the bootcounter on an i2c (like RTC) device.
3201 CONFIG_SYS_I2C_RTC_ADDR = i2c chip address
3202 CONFIG_SYS_BOOTCOUNT_ADDR = i2c addr which is used for
3204 CONFIG_BOOTCOUNT_ALEN = address len
3206 - Show boot progress:
3207 CONFIG_SHOW_BOOT_PROGRESS
3209 Defining this option allows to add some board-
3210 specific code (calling a user-provided function
3211 "show_boot_progress(int)") that enables you to show
3212 the system's boot progress on some display (for
3213 example, some LED's) on your board. At the moment,
3214 the following checkpoints are implemented:
3217 Legacy uImage format:
3220 1 common/cmd_bootm.c before attempting to boot an image
3221 -1 common/cmd_bootm.c Image header has bad magic number
3222 2 common/cmd_bootm.c Image header has correct magic number
3223 -2 common/cmd_bootm.c Image header has bad checksum
3224 3 common/cmd_bootm.c Image header has correct checksum
3225 -3 common/cmd_bootm.c Image data has bad checksum
3226 4 common/cmd_bootm.c Image data has correct checksum
3227 -4 common/cmd_bootm.c Image is for unsupported architecture
3228 5 common/cmd_bootm.c Architecture check OK
3229 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi)
3230 6 common/cmd_bootm.c Image Type check OK
3231 -6 common/cmd_bootm.c gunzip uncompression error
3232 -7 common/cmd_bootm.c Unimplemented compression type
3233 7 common/cmd_bootm.c Uncompression OK
3234 8 common/cmd_bootm.c No uncompress/copy overwrite error
3235 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX)
3237 9 common/image.c Start initial ramdisk verification
3238 -10 common/image.c Ramdisk header has bad magic number
3239 -11 common/image.c Ramdisk header has bad checksum
3240 10 common/image.c Ramdisk header is OK
3241 -12 common/image.c Ramdisk data has bad checksum
3242 11 common/image.c Ramdisk data has correct checksum
3243 12 common/image.c Ramdisk verification complete, start loading
3244 -13 common/image.c Wrong Image Type (not PPC Linux ramdisk)
3245 13 common/image.c Start multifile image verification
3246 14 common/image.c No initial ramdisk, no multifile, continue.
3248 15 arch/<arch>/lib/bootm.c All preparation done, transferring control to OS
3250 -30 arch/powerpc/lib/board.c Fatal error, hang the system
3251 -31 post/post.c POST test failed, detected by post_output_backlog()
3252 -32 post/post.c POST test failed, detected by post_run_single()
3254 34 common/cmd_doc.c before loading a Image from a DOC device
3255 -35 common/cmd_doc.c Bad usage of "doc" command
3256 35 common/cmd_doc.c correct usage of "doc" command
3257 -36 common/cmd_doc.c No boot device
3258 36 common/cmd_doc.c correct boot device
3259 -37 common/cmd_doc.c Unknown Chip ID on boot device
3260 37 common/cmd_doc.c correct chip ID found, device available
3261 -38 common/cmd_doc.c Read Error on boot device
3262 38 common/cmd_doc.c reading Image header from DOC device OK
3263 -39 common/cmd_doc.c Image header has bad magic number
3264 39 common/cmd_doc.c Image header has correct magic number
3265 -40 common/cmd_doc.c Error reading Image from DOC device
3266 40 common/cmd_doc.c Image header has correct magic number
3267 41 common/cmd_ide.c before loading a Image from a IDE device
3268 -42 common/cmd_ide.c Bad usage of "ide" command
3269 42 common/cmd_ide.c correct usage of "ide" command
3270 -43 common/cmd_ide.c No boot device
3271 43 common/cmd_ide.c boot device found
3272 -44 common/cmd_ide.c Device not available
3273 44 common/cmd_ide.c Device available
3274 -45 common/cmd_ide.c wrong partition selected
3275 45 common/cmd_ide.c partition selected
3276 -46 common/cmd_ide.c Unknown partition table
3277 46 common/cmd_ide.c valid partition table found
3278 -47 common/cmd_ide.c Invalid partition type
3279 47 common/cmd_ide.c correct partition type
3280 -48 common/cmd_ide.c Error reading Image Header on boot device
3281 48 common/cmd_ide.c reading Image Header from IDE device OK
3282 -49 common/cmd_ide.c Image header has bad magic number
3283 49 common/cmd_ide.c Image header has correct magic number
3284 -50 common/cmd_ide.c Image header has bad checksum
3285 50 common/cmd_ide.c Image header has correct checksum
3286 -51 common/cmd_ide.c Error reading Image from IDE device
3287 51 common/cmd_ide.c reading Image from IDE device OK
3288 52 common/cmd_nand.c before loading a Image from a NAND device
3289 -53 common/cmd_nand.c Bad usage of "nand" command
3290 53 common/cmd_nand.c correct usage of "nand" command
3291 -54 common/cmd_nand.c No boot device
3292 54 common/cmd_nand.c boot device found
3293 -55 common/cmd_nand.c Unknown Chip ID on boot device
3294 55 common/cmd_nand.c correct chip ID found, device available
3295 -56 common/cmd_nand.c Error reading Image Header on boot device
3296 56 common/cmd_nand.c reading Image Header from NAND device OK
3297 -57 common/cmd_nand.c Image header has bad magic number
3298 57 common/cmd_nand.c Image header has correct magic number
3299 -58 common/cmd_nand.c Error reading Image from NAND device
3300 58 common/cmd_nand.c reading Image from NAND device OK
3302 -60 common/env_common.c Environment has a bad CRC, using default
3304 64 net/eth.c starting with Ethernet configuration.
3305 -64 net/eth.c no Ethernet found.
3306 65 net/eth.c Ethernet found.
3308 -80 common/cmd_net.c usage wrong
3309 80 common/cmd_net.c before calling net_loop()
3310 -81 common/cmd_net.c some error in net_loop() occurred
3311 81 common/cmd_net.c net_loop() back without error
3312 -82 common/cmd_net.c size == 0 (File with size 0 loaded)
3313 82 common/cmd_net.c trying automatic boot
3314 83 common/cmd_net.c running "source" command
3315 -83 common/cmd_net.c some error in automatic boot or "source" command
3316 84 common/cmd_net.c end without errors
3321 100 common/cmd_bootm.c Kernel FIT Image has correct format
3322 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format
3323 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration
3324 -101 common/cmd_bootm.c Can't get configuration for kernel subimage
3325 102 common/cmd_bootm.c Kernel unit name specified
3326 -103 common/cmd_bootm.c Can't get kernel subimage node offset
3327 103 common/cmd_bootm.c Found configuration node
3328 104 common/cmd_bootm.c Got kernel subimage node offset
3329 -104 common/cmd_bootm.c Kernel subimage hash verification failed
3330 105 common/cmd_bootm.c Kernel subimage hash verification OK
3331 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture
3332 106 common/cmd_bootm.c Architecture check OK
3333 -106 common/cmd_bootm.c Kernel subimage has wrong type
3334 107 common/cmd_bootm.c Kernel subimage type OK
3335 -107 common/cmd_bootm.c Can't get kernel subimage data/size
3336 108 common/cmd_bootm.c Got kernel subimage data/size
3337 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT)
3338 -109 common/cmd_bootm.c Can't get kernel subimage type
3339 -110 common/cmd_bootm.c Can't get kernel subimage comp
3340 -111 common/cmd_bootm.c Can't get kernel subimage os
3341 -112 common/cmd_bootm.c Can't get kernel subimage load address
3342 -113 common/cmd_bootm.c Image uncompress/copy overwrite error
3344 120 common/image.c Start initial ramdisk verification
3345 -120 common/image.c Ramdisk FIT image has incorrect format
3346 121 common/image.c Ramdisk FIT image has correct format
3347 122 common/image.c No ramdisk subimage unit name, using configuration
3348 -122 common/image.c Can't get configuration for ramdisk subimage
3349 123 common/image.c Ramdisk unit name specified
3350 -124 common/image.c Can't get ramdisk subimage node offset
3351 125 common/image.c Got ramdisk subimage node offset
3352 -125 common/image.c Ramdisk subimage hash verification failed
3353 126 common/image.c Ramdisk subimage hash verification OK
3354 -126 common/image.c Ramdisk subimage for unsupported architecture
3355 127 common/image.c Architecture check OK
3356 -127 common/image.c Can't get ramdisk subimage data/size
3357 128 common/image.c Got ramdisk subimage data/size
3358 129 common/image.c Can't get ramdisk load address
3359 -129 common/image.c Got ramdisk load address
3361 -130 common/cmd_doc.c Incorrect FIT image format
3362 131 common/cmd_doc.c FIT image format OK
3364 -140 common/cmd_ide.c Incorrect FIT image format
3365 141 common/cmd_ide.c FIT image format OK
3367 -150 common/cmd_nand.c Incorrect FIT image format
3368 151 common/cmd_nand.c FIT image format OK
3370 - legacy image format:
3371 CONFIG_IMAGE_FORMAT_LEGACY
3372 enables the legacy image format support in U-Boot.
3375 enabled if CONFIG_FIT_SIGNATURE is not defined.
3377 CONFIG_DISABLE_IMAGE_LEGACY
3378 disable the legacy image format
3380 This define is introduced, as the legacy image format is
3381 enabled per default for backward compatibility.
3383 - FIT image support:
3385 Enable support for the FIT uImage format.
3387 CONFIG_FIT_BEST_MATCH
3388 When no configuration is explicitly selected, default to the
3389 one whose fdt's compatibility field best matches that of
3390 U-Boot itself. A match is considered "best" if it matches the
3391 most specific compatibility entry of U-Boot's fdt's root node.
3392 The order of entries in the configuration's fdt is ignored.
3394 CONFIG_FIT_SIGNATURE
3395 This option enables signature verification of FIT uImages,
3396 using a hash signed and verified using RSA. If
3397 CONFIG_SHA_PROG_HW_ACCEL is defined, i.e support for progressive
3398 hashing is available using hardware, RSA library will use it.
3399 See doc/uImage.FIT/signature.txt for more details.
3401 WARNING: When relying on signed FIT images with required
3402 signature check the legacy image format is default
3403 disabled. If a board need legacy image format support
3404 enable this through CONFIG_IMAGE_FORMAT_LEGACY
3406 CONFIG_FIT_DISABLE_SHA256
3407 Supporting SHA256 hashes has quite an impact on binary size.
3408 For constrained systems sha256 hash support can be disabled
3411 - Standalone program support:
3412 CONFIG_STANDALONE_LOAD_ADDR
3414 This option defines a board specific value for the
3415 address where standalone program gets loaded, thus
3416 overwriting the architecture dependent default
3419 - Frame Buffer Address:
3422 Define CONFIG_FB_ADDR if you want to use specific
3423 address for frame buffer. This is typically the case
3424 when using a graphics controller has separate video
3425 memory. U-Boot will then place the frame buffer at
3426 the given address instead of dynamically reserving it
3427 in system RAM by calling lcd_setmem(), which grabs
3428 the memory for the frame buffer depending on the
3429 configured panel size.
3431 Please see board_init_f function.
3433 - Automatic software updates via TFTP server
3435 CONFIG_UPDATE_TFTP_CNT_MAX
3436 CONFIG_UPDATE_TFTP_MSEC_MAX
3438 These options enable and control the auto-update feature;
3439 for a more detailed description refer to doc/README.update.
3441 - MTD Support (mtdparts command, UBI support)
3444 Adds the MTD device infrastructure from the Linux kernel.
3445 Needed for mtdparts command support.
3447 CONFIG_MTD_PARTITIONS
3449 Adds the MTD partitioning infrastructure from the Linux
3450 kernel. Needed for UBI support.
3455 Adds commands for interacting with MTD partitions formatted
3456 with the UBI flash translation layer
3458 Requires also defining CONFIG_RBTREE
3460 CONFIG_UBI_SILENCE_MSG
3462 Make the verbose messages from UBI stop printing. This leaves
3463 warnings and errors enabled.
3466 CONFIG_MTD_UBI_WL_THRESHOLD
3467 This parameter defines the maximum difference between the highest
3468 erase counter value and the lowest erase counter value of eraseblocks
3469 of UBI devices. When this threshold is exceeded, UBI starts performing
3470 wear leveling by means of moving data from eraseblock with low erase
3471 counter to eraseblocks with high erase counter.
3473 The default value should be OK for SLC NAND flashes, NOR flashes and
3474 other flashes which have eraseblock life-cycle 100000 or more.
3475 However, in case of MLC NAND flashes which typically have eraseblock
3476 life-cycle less than 10000, the threshold should be lessened (e.g.,
3477 to 128 or 256, although it does not have to be power of 2).
3481 CONFIG_MTD_UBI_BEB_LIMIT
3482 This option specifies the maximum bad physical eraseblocks UBI
3483 expects on the MTD device (per 1024 eraseblocks). If the
3484 underlying flash does not admit of bad eraseblocks (e.g. NOR
3485 flash), this value is ignored.
3487 NAND datasheets often specify the minimum and maximum NVM
3488 (Number of Valid Blocks) for the flashes' endurance lifetime.
3489 The maximum expected bad eraseblocks per 1024 eraseblocks
3490 then can be calculated as "1024 * (1 - MinNVB / MaxNVB)",
3491 which gives 20 for most NANDs (MaxNVB is basically the total
3492 count of eraseblocks on the chip).
3494 To put it differently, if this value is 20, UBI will try to
3495 reserve about 1.9% of physical eraseblocks for bad blocks
3496 handling. And that will be 1.9% of eraseblocks on the entire
3497 NAND chip, not just the MTD partition UBI attaches. This means
3498 that if you have, say, a NAND flash chip admits maximum 40 bad
3499 eraseblocks, and it is split on two MTD partitions of the same
3500 size, UBI will reserve 40 eraseblocks when attaching a
3505 CONFIG_MTD_UBI_FASTMAP
3506 Fastmap is a mechanism which allows attaching an UBI device
3507 in nearly constant time. Instead of scanning the whole MTD device it
3508 only has to locate a checkpoint (called fastmap) on the device.
3509 The on-flash fastmap contains all information needed to attach
3510 the device. Using fastmap makes only sense on large devices where
3511 attaching by scanning takes long. UBI will not automatically install
3512 a fastmap on old images, but you can set the UBI parameter
3513 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT to 1 if you want so. Please note
3514 that fastmap-enabled images are still usable with UBI implementations
3515 without fastmap support. On typical flash devices the whole fastmap
3516 fits into one PEB. UBI will reserve PEBs to hold two fastmaps.
3518 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT
3519 Set this parameter to enable fastmap automatically on images
3526 Adds commands for interacting with UBI volumes formatted as
3527 UBIFS. UBIFS is read-only in u-boot.
3529 Requires UBI support as well as CONFIG_LZO
3531 CONFIG_UBIFS_SILENCE_MSG
3533 Make the verbose messages from UBIFS stop printing. This leaves
3534 warnings and errors enabled.
3538 Enable building of SPL globally.
3541 LDSCRIPT for linking the SPL binary.
3543 CONFIG_SPL_MAX_FOOTPRINT
3544 Maximum size in memory allocated to the SPL, BSS included.
3545 When defined, the linker checks that the actual memory
3546 used by SPL from _start to __bss_end does not exceed it.
3547 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
3548 must not be both defined at the same time.
3551 Maximum size of the SPL image (text, data, rodata, and
3552 linker lists sections), BSS excluded.
3553 When defined, the linker checks that the actual size does
3556 CONFIG_SPL_TEXT_BASE
3557 TEXT_BASE for linking the SPL binary.
3559 CONFIG_SPL_RELOC_TEXT_BASE
3560 Address to relocate to. If unspecified, this is equal to
3561 CONFIG_SPL_TEXT_BASE (i.e. no relocation is done).
3563 CONFIG_SPL_BSS_START_ADDR
3564 Link address for the BSS within the SPL binary.
3566 CONFIG_SPL_BSS_MAX_SIZE
3567 Maximum size in memory allocated to the SPL BSS.
3568 When defined, the linker checks that the actual memory used
3569 by SPL from __bss_start to __bss_end does not exceed it.
3570 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
3571 must not be both defined at the same time.
3574 Adress of the start of the stack SPL will use
3576 CONFIG_SPL_PANIC_ON_RAW_IMAGE
3577 When defined, SPL will panic() if the image it has
3578 loaded does not have a signature.
3579 Defining this is useful when code which loads images
3580 in SPL cannot guarantee that absolutely all read errors
3582 An example is the LPC32XX MLC NAND driver, which will
3583 consider that a completely unreadable NAND block is bad,
3584 and thus should be skipped silently.
3586 CONFIG_SPL_RELOC_STACK
3587 Adress of the start of the stack SPL will use after
3588 relocation. If unspecified, this is equal to
3591 CONFIG_SYS_SPL_MALLOC_START
3592 Starting address of the malloc pool used in SPL.
3594 CONFIG_SYS_SPL_MALLOC_SIZE
3595 The size of the malloc pool used in SPL.
3597 CONFIG_SPL_FRAMEWORK
3598 Enable the SPL framework under common/. This framework
3599 supports MMC, NAND and YMODEM loading of U-Boot and NAND
3600 NAND loading of the Linux Kernel.
3603 Enable booting directly to an OS from SPL.
3604 See also: doc/README.falcon
3606 CONFIG_SPL_DISPLAY_PRINT
3607 For ARM, enable an optional function to print more information
3608 about the running system.
3610 CONFIG_SPL_INIT_MINIMAL
3611 Arch init code should be built for a very small image
3613 CONFIG_SPL_LIBCOMMON_SUPPORT
3614 Support for common/libcommon.o in SPL binary
3616 CONFIG_SPL_LIBDISK_SUPPORT
3617 Support for disk/libdisk.o in SPL binary
3619 CONFIG_SPL_I2C_SUPPORT
3620 Support for drivers/i2c/libi2c.o in SPL binary
3622 CONFIG_SPL_GPIO_SUPPORT
3623 Support for drivers/gpio/libgpio.o in SPL binary
3625 CONFIG_SPL_MMC_SUPPORT
3626 Support for drivers/mmc/libmmc.o in SPL binary
3628 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_SECTOR,
3629 CONFIG_SYS_U_BOOT_MAX_SIZE_SECTORS,
3630 Address and partition on the MMC to load U-Boot from
3631 when the MMC is being used in raw mode.
3633 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_PARTITION
3634 Partition on the MMC to load U-Boot from when the MMC is being
3637 CONFIG_SYS_MMCSD_RAW_MODE_KERNEL_SECTOR
3638 Sector to load kernel uImage from when MMC is being
3639 used in raw mode (for Falcon mode)
3641 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTOR,
3642 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTORS
3643 Sector and number of sectors to load kernel argument
3644 parameters from when MMC is being used in raw mode
3647 CONFIG_SYS_MMCSD_FS_BOOT_PARTITION
3648 Partition on the MMC to load U-Boot from when the MMC is being
3651 CONFIG_SPL_FAT_SUPPORT
3652 Support for fs/fat/libfat.o in SPL binary
3654 CONFIG_SPL_EXT_SUPPORT
3655 Support for EXT filesystem in SPL binary
3657 CONFIG_SPL_FS_LOAD_PAYLOAD_NAME
3658 Filename to read to load U-Boot when reading from filesystem
3660 CONFIG_SPL_FS_LOAD_KERNEL_NAME
3661 Filename to read to load kernel uImage when reading
3662 from filesystem (for Falcon mode)
3664 CONFIG_SPL_FS_LOAD_ARGS_NAME
3665 Filename to read to load kernel argument parameters
3666 when reading from filesystem (for Falcon mode)
3668 CONFIG_SPL_MPC83XX_WAIT_FOR_NAND
3669 Set this for NAND SPL on PPC mpc83xx targets, so that
3670 start.S waits for the rest of the SPL to load before
3671 continuing (the hardware starts execution after just
3672 loading the first page rather than the full 4K).
3674 CONFIG_SPL_SKIP_RELOCATE
3675 Avoid SPL relocation
3677 CONFIG_SPL_NAND_BASE
3678 Include nand_base.c in the SPL. Requires
3679 CONFIG_SPL_NAND_DRIVERS.
3681 CONFIG_SPL_NAND_DRIVERS
3682 SPL uses normal NAND drivers, not minimal drivers.
3685 Include standard software ECC in the SPL
3687 CONFIG_SPL_NAND_SIMPLE
3688 Support for NAND boot using simple NAND drivers that
3689 expose the cmd_ctrl() interface.
3691 CONFIG_SPL_MTD_SUPPORT
3692 Support for the MTD subsystem within SPL. Useful for
3693 environment on NAND support within SPL.
3695 CONFIG_SPL_NAND_RAW_ONLY
3696 Support to boot only raw u-boot.bin images. Use this only
3697 if you need to save space.
3699 CONFIG_SPL_MPC8XXX_INIT_DDR_SUPPORT
3700 Set for the SPL on PPC mpc8xxx targets, support for
3701 drivers/ddr/fsl/libddr.o in SPL binary.
3703 CONFIG_SPL_COMMON_INIT_DDR
3704 Set for common ddr init with serial presence detect in
3707 CONFIG_SYS_NAND_5_ADDR_CYCLE, CONFIG_SYS_NAND_PAGE_COUNT,
3708 CONFIG_SYS_NAND_PAGE_SIZE, CONFIG_SYS_NAND_OOBSIZE,
3709 CONFIG_SYS_NAND_BLOCK_SIZE, CONFIG_SYS_NAND_BAD_BLOCK_POS,
3710 CONFIG_SYS_NAND_ECCPOS, CONFIG_SYS_NAND_ECCSIZE,
3711 CONFIG_SYS_NAND_ECCBYTES
3712 Defines the size and behavior of the NAND that SPL uses
3715 CONFIG_SPL_NAND_BOOT
3716 Add support NAND boot
3718 CONFIG_SYS_NAND_U_BOOT_OFFS
3719 Location in NAND to read U-Boot from
3721 CONFIG_SYS_NAND_U_BOOT_DST
3722 Location in memory to load U-Boot to
3724 CONFIG_SYS_NAND_U_BOOT_SIZE
3725 Size of image to load
3727 CONFIG_SYS_NAND_U_BOOT_START
3728 Entry point in loaded image to jump to
3730 CONFIG_SYS_NAND_HW_ECC_OOBFIRST
3731 Define this if you need to first read the OOB and then the
3732 data. This is used, for example, on davinci platforms.
3734 CONFIG_SPL_OMAP3_ID_NAND
3735 Support for an OMAP3-specific set of functions to return the
3736 ID and MFR of the first attached NAND chip, if present.
3738 CONFIG_SPL_SERIAL_SUPPORT
3739 Support for drivers/serial/libserial.o in SPL binary
3741 CONFIG_SPL_SPI_FLASH_SUPPORT
3742 Support for drivers/mtd/spi/libspi_flash.o in SPL binary
3744 CONFIG_SPL_SPI_SUPPORT
3745 Support for drivers/spi/libspi.o in SPL binary
3747 CONFIG_SPL_RAM_DEVICE
3748 Support for running image already present in ram, in SPL binary
3750 CONFIG_SPL_LIBGENERIC_SUPPORT
3751 Support for lib/libgeneric.o in SPL binary
3753 CONFIG_SPL_ENV_SUPPORT
3754 Support for the environment operating in SPL binary
3756 CONFIG_SPL_NET_SUPPORT
3757 Support for the net/libnet.o in SPL binary.
3758 It conflicts with SPL env from storage medium specified by
3759 CONFIG_ENV_IS_xxx but CONFIG_ENV_IS_NOWHERE
3762 Image offset to which the SPL should be padded before appending
3763 the SPL payload. By default, this is defined as
3764 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3765 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3766 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3769 Final target image containing SPL and payload. Some SPLs
3770 use an arch-specific makefile fragment instead, for
3771 example if more than one image needs to be produced.
3773 CONFIG_FIT_SPL_PRINT
3774 Printing information about a FIT image adds quite a bit of
3775 code to SPL. So this is normally disabled in SPL. Use this
3776 option to re-enable it. This will affect the output of the
3777 bootm command when booting a FIT image.
3781 Enable building of TPL globally.
3784 Image offset to which the TPL should be padded before appending
3785 the TPL payload. By default, this is defined as
3786 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3787 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3788 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3793 [so far only for SMDK2400 boards]
3795 - Modem support enable:
3796 CONFIG_MODEM_SUPPORT
3798 - RTS/CTS Flow control enable:
3801 - Modem debug support:
3802 CONFIG_MODEM_SUPPORT_DEBUG
3804 Enables debugging stuff (char screen[1024], dbg())
3805 for modem support. Useful only with BDI2000.
3807 - Interrupt support (PPC):
3809 There are common interrupt_init() and timer_interrupt()
3810 for all PPC archs. interrupt_init() calls interrupt_init_cpu()
3811 for CPU specific initialization. interrupt_init_cpu()
3812 should set decrementer_count to appropriate value. If
3813 CPU resets decrementer automatically after interrupt
3814 (ppc4xx) it should set decrementer_count to zero.
3815 timer_interrupt() calls timer_interrupt_cpu() for CPU
3816 specific handling. If board has watchdog / status_led
3817 / other_activity_monitor it works automatically from
3818 general timer_interrupt().
3822 In the target system modem support is enabled when a
3823 specific key (key combination) is pressed during
3824 power-on. Otherwise U-Boot will boot normally
3825 (autoboot). The key_pressed() function is called from
3826 board_init(). Currently key_pressed() is a dummy
3827 function, returning 1 and thus enabling modem
3830 If there are no modem init strings in the
3831 environment, U-Boot proceed to autoboot; the
3832 previous output (banner, info printfs) will be
3835 See also: doc/README.Modem
3837 Board initialization settings:
3838 ------------------------------
3840 During Initialization u-boot calls a number of board specific functions
3841 to allow the preparation of board specific prerequisites, e.g. pin setup
3842 before drivers are initialized. To enable these callbacks the
3843 following configuration macros have to be defined. Currently this is
3844 architecture specific, so please check arch/your_architecture/lib/board.c
3845 typically in board_init_f() and board_init_r().
3847 - CONFIG_BOARD_EARLY_INIT_F: Call board_early_init_f()
3848 - CONFIG_BOARD_EARLY_INIT_R: Call board_early_init_r()
3849 - CONFIG_BOARD_LATE_INIT: Call board_late_init()
3850 - CONFIG_BOARD_POSTCLK_INIT: Call board_postclk_init()
3852 Configuration Settings:
3853 -----------------------
3855 - CONFIG_SYS_SUPPORT_64BIT_DATA: Defined automatically if compiled as 64-bit.
3856 Optionally it can be defined to support 64-bit memory commands.
3858 - CONFIG_SYS_LONGHELP: Defined when you want long help messages included;
3859 undefine this when you're short of memory.
3861 - CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default
3862 width of the commands listed in the 'help' command output.
3864 - CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to
3865 prompt for user input.
3867 - CONFIG_SYS_CBSIZE: Buffer size for input from the Console
3869 - CONFIG_SYS_PBSIZE: Buffer size for Console output
3871 - CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands
3873 - CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to
3874 the application (usually a Linux kernel) when it is
3877 - CONFIG_SYS_BAUDRATE_TABLE:
3878 List of legal baudrate settings for this board.
3880 - CONFIG_SYS_CONSOLE_INFO_QUIET
3881 Suppress display of console information at boot.
3883 - CONFIG_SYS_CONSOLE_IS_IN_ENV
3884 If the board specific function
3885 extern int overwrite_console (void);
3886 returns 1, the stdin, stderr and stdout are switched to the
3887 serial port, else the settings in the environment are used.
3889 - CONFIG_SYS_CONSOLE_OVERWRITE_ROUTINE
3890 Enable the call to overwrite_console().
3892 - CONFIG_SYS_CONSOLE_ENV_OVERWRITE
3893 Enable overwrite of previous console environment settings.
3895 - CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END:
3896 Begin and End addresses of the area used by the
3899 - CONFIG_SYS_ALT_MEMTEST:
3900 Enable an alternate, more extensive memory test.
3902 - CONFIG_SYS_MEMTEST_SCRATCH:
3903 Scratch address used by the alternate memory test
3904 You only need to set this if address zero isn't writeable
3906 - CONFIG_SYS_MEM_TOP_HIDE (PPC only):
3907 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header,
3908 this specified memory area will get subtracted from the top
3909 (end) of RAM and won't get "touched" at all by U-Boot. By
3910 fixing up gd->ram_size the Linux kernel should gets passed
3911 the now "corrected" memory size and won't touch it either.
3912 This should work for arch/ppc and arch/powerpc. Only Linux
3913 board ports in arch/powerpc with bootwrapper support that
3914 recalculate the memory size from the SDRAM controller setup
3915 will have to get fixed in Linux additionally.
3917 This option can be used as a workaround for the 440EPx/GRx
3918 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't
3921 WARNING: Please make sure that this value is a multiple of
3922 the Linux page size (normally 4k). If this is not the case,
3923 then the end address of the Linux memory will be located at a
3924 non page size aligned address and this could cause major
3927 - CONFIG_SYS_LOADS_BAUD_CHANGE:
3928 Enable temporary baudrate change while serial download
3930 - CONFIG_SYS_SDRAM_BASE:
3931 Physical start address of SDRAM. _Must_ be 0 here.
3933 - CONFIG_SYS_MBIO_BASE:
3934 Physical start address of Motherboard I/O (if using a
3937 - CONFIG_SYS_FLASH_BASE:
3938 Physical start address of Flash memory.
3940 - CONFIG_SYS_MONITOR_BASE:
3941 Physical start address of boot monitor code (set by
3942 make config files to be same as the text base address
3943 (CONFIG_SYS_TEXT_BASE) used when linking) - same as
3944 CONFIG_SYS_FLASH_BASE when booting from flash.
3946 - CONFIG_SYS_MONITOR_LEN:
3947 Size of memory reserved for monitor code, used to
3948 determine _at_compile_time_ (!) if the environment is
3949 embedded within the U-Boot image, or in a separate
3952 - CONFIG_SYS_MALLOC_LEN:
3953 Size of DRAM reserved for malloc() use.
3955 - CONFIG_SYS_MALLOC_F_LEN
3956 Size of the malloc() pool for use before relocation. If
3957 this is defined, then a very simple malloc() implementation
3958 will become available before relocation. The address is just
3959 below the global data, and the stack is moved down to make
3962 This feature allocates regions with increasing addresses
3963 within the region. calloc() is supported, but realloc()
3964 is not available. free() is supported but does nothing.
3965 The memory will be freed (or in fact just forgotten) when
3966 U-Boot relocates itself.
3968 Pre-relocation malloc() is only supported on ARM and sandbox
3969 at present but is fairly easy to enable for other archs.
3971 - CONFIG_SYS_MALLOC_SIMPLE
3972 Provides a simple and small malloc() and calloc() for those
3973 boards which do not use the full malloc in SPL (which is
3974 enabled with CONFIG_SYS_SPL_MALLOC_START).
3976 - CONFIG_SYS_NONCACHED_MEMORY:
3977 Size of non-cached memory area. This area of memory will be
3978 typically located right below the malloc() area and mapped
3979 uncached in the MMU. This is useful for drivers that would
3980 otherwise require a lot of explicit cache maintenance. For
3981 some drivers it's also impossible to properly maintain the
3982 cache. For example if the regions that need to be flushed
3983 are not a multiple of the cache-line size, *and* padding
3984 cannot be allocated between the regions to align them (i.e.
3985 if the HW requires a contiguous array of regions, and the
3986 size of each region is not cache-aligned), then a flush of
3987 one region may result in overwriting data that hardware has
3988 written to another region in the same cache-line. This can
3989 happen for example in network drivers where descriptors for
3990 buffers are typically smaller than the CPU cache-line (e.g.
3991 16 bytes vs. 32 or 64 bytes).
3993 Non-cached memory is only supported on 32-bit ARM at present.
3995 - CONFIG_SYS_BOOTM_LEN:
3996 Normally compressed uImages are limited to an
3997 uncompressed size of 8 MBytes. If this is not enough,
3998 you can define CONFIG_SYS_BOOTM_LEN in your board config file
3999 to adjust this setting to your needs.
4001 - CONFIG_SYS_BOOTMAPSZ:
4002 Maximum size of memory mapped by the startup code of
4003 the Linux kernel; all data that must be processed by
4004 the Linux kernel (bd_info, boot arguments, FDT blob if
4005 used) must be put below this limit, unless "bootm_low"
4006 environment variable is defined and non-zero. In such case
4007 all data for the Linux kernel must be between "bootm_low"
4008 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ. The environment
4009 variable "bootm_mapsize" will override the value of
4010 CONFIG_SYS_BOOTMAPSZ. If CONFIG_SYS_BOOTMAPSZ is undefined,
4011 then the value in "bootm_size" will be used instead.
4013 - CONFIG_SYS_BOOT_RAMDISK_HIGH:
4014 Enable initrd_high functionality. If defined then the
4015 initrd_high feature is enabled and the bootm ramdisk subcommand
4018 - CONFIG_SYS_BOOT_GET_CMDLINE:
4019 Enables allocating and saving kernel cmdline in space between
4020 "bootm_low" and "bootm_low" + BOOTMAPSZ.
4022 - CONFIG_SYS_BOOT_GET_KBD:
4023 Enables allocating and saving a kernel copy of the bd_info in
4024 space between "bootm_low" and "bootm_low" + BOOTMAPSZ.
4026 - CONFIG_SYS_MAX_FLASH_BANKS:
4027 Max number of Flash memory banks
4029 - CONFIG_SYS_MAX_FLASH_SECT:
4030 Max number of sectors on a Flash chip
4032 - CONFIG_SYS_FLASH_ERASE_TOUT:
4033 Timeout for Flash erase operations (in ms)
4035 - CONFIG_SYS_FLASH_WRITE_TOUT:
4036 Timeout for Flash write operations (in ms)
4038 - CONFIG_SYS_FLASH_LOCK_TOUT
4039 Timeout for Flash set sector lock bit operation (in ms)
4041 - CONFIG_SYS_FLASH_UNLOCK_TOUT
4042 Timeout for Flash clear lock bits operation (in ms)
4044 - CONFIG_SYS_FLASH_PROTECTION
4045 If defined, hardware flash sectors protection is used
4046 instead of U-Boot software protection.
4048 - CONFIG_SYS_DIRECT_FLASH_TFTP:
4050 Enable TFTP transfers directly to flash memory;
4051 without this option such a download has to be
4052 performed in two steps: (1) download to RAM, and (2)
4053 copy from RAM to flash.
4055 The two-step approach is usually more reliable, since
4056 you can check if the download worked before you erase
4057 the flash, but in some situations (when system RAM is
4058 too limited to allow for a temporary copy of the
4059 downloaded image) this option may be very useful.
4061 - CONFIG_SYS_FLASH_CFI:
4062 Define if the flash driver uses extra elements in the
4063 common flash structure for storing flash geometry.
4065 - CONFIG_FLASH_CFI_DRIVER
4066 This option also enables the building of the cfi_flash driver
4067 in the drivers directory
4069 - CONFIG_FLASH_CFI_MTD
4070 This option enables the building of the cfi_mtd driver
4071 in the drivers directory. The driver exports CFI flash
4074 - CONFIG_SYS_FLASH_USE_BUFFER_WRITE
4075 Use buffered writes to flash.
4077 - CONFIG_FLASH_SPANSION_S29WS_N
4078 s29ws-n MirrorBit flash has non-standard addresses for buffered
4081 - CONFIG_SYS_FLASH_QUIET_TEST
4082 If this option is defined, the common CFI flash doesn't
4083 print it's warning upon not recognized FLASH banks. This
4084 is useful, if some of the configured banks are only
4085 optionally available.
4087 - CONFIG_FLASH_SHOW_PROGRESS
4088 If defined (must be an integer), print out countdown
4089 digits and dots. Recommended value: 45 (9..1) for 80
4090 column displays, 15 (3..1) for 40 column displays.
4092 - CONFIG_FLASH_VERIFY
4093 If defined, the content of the flash (destination) is compared
4094 against the source after the write operation. An error message
4095 will be printed when the contents are not identical.
4096 Please note that this option is useless in nearly all cases,
4097 since such flash programming errors usually are detected earlier
4098 while unprotecting/erasing/programming. Please only enable
4099 this option if you really know what you are doing.
4101 - CONFIG_SYS_RX_ETH_BUFFER:
4102 Defines the number of Ethernet receive buffers. On some
4103 Ethernet controllers it is recommended to set this value
4104 to 8 or even higher (EEPRO100 or 405 EMAC), since all
4105 buffers can be full shortly after enabling the interface
4106 on high Ethernet traffic.
4107 Defaults to 4 if not defined.
4109 - CONFIG_ENV_MAX_ENTRIES
4111 Maximum number of entries in the hash table that is used
4112 internally to store the environment settings. The default
4113 setting is supposed to be generous and should work in most
4114 cases. This setting can be used to tune behaviour; see
4115 lib/hashtable.c for details.
4117 - CONFIG_ENV_FLAGS_LIST_DEFAULT
4118 - CONFIG_ENV_FLAGS_LIST_STATIC
4119 Enable validation of the values given to environment variables when
4120 calling env set. Variables can be restricted to only decimal,
4121 hexadecimal, or boolean. If CONFIG_CMD_NET is also defined,
4122 the variables can also be restricted to IP address or MAC address.
4124 The format of the list is:
4125 type_attribute = [s|d|x|b|i|m]
4126 access_attribute = [a|r|o|c]
4127 attributes = type_attribute[access_attribute]
4128 entry = variable_name[:attributes]
4131 The type attributes are:
4132 s - String (default)
4135 b - Boolean ([1yYtT|0nNfF])
4139 The access attributes are:
4145 - CONFIG_ENV_FLAGS_LIST_DEFAULT
4146 Define this to a list (string) to define the ".flags"
4147 environment variable in the default or embedded environment.
4149 - CONFIG_ENV_FLAGS_LIST_STATIC
4150 Define this to a list (string) to define validation that
4151 should be done if an entry is not found in the ".flags"
4152 environment variable. To override a setting in the static
4153 list, simply add an entry for the same variable name to the
4156 If CONFIG_REGEX is defined, the variable_name above is evaluated as a
4157 regular expression. This allows multiple variables to define the same
4158 flags without explicitly listing them for each variable.
4160 - CONFIG_ENV_ACCESS_IGNORE_FORCE
4161 If defined, don't allow the -f switch to env set override variable
4164 - CONFIG_SYS_GENERIC_BOARD
4165 This selects the architecture-generic board system instead of the
4166 architecture-specific board files. It is intended to move boards
4167 to this new framework over time. Defining this will disable the
4168 arch/foo/lib/board.c file and use common/board_f.c and
4169 common/board_r.c instead. To use this option your architecture
4170 must support it (i.e. must select HAVE_GENERIC_BOARD in arch/Kconfig).
4171 If you find problems enabling this option on your board please report
4172 the problem and send patches!
4174 - CONFIG_OMAP_PLATFORM_RESET_TIME_MAX_USEC (OMAP only)
4175 This is set by OMAP boards for the max time that reset should
4176 be asserted. See doc/README.omap-reset-time for details on how
4177 the value can be calculated on a given board.
4180 If stdint.h is available with your toolchain you can define this
4181 option to enable it. You can provide option 'USE_STDINT=1' when
4182 building U-Boot to enable this.
4184 The following definitions that deal with the placement and management
4185 of environment data (variable area); in general, we support the
4186 following configurations:
4188 - CONFIG_BUILD_ENVCRC:
4190 Builds up envcrc with the target environment so that external utils
4191 may easily extract it and embed it in final U-Boot images.
4193 - CONFIG_ENV_IS_IN_FLASH:
4195 Define this if the environment is in flash memory.
4197 a) The environment occupies one whole flash sector, which is
4198 "embedded" in the text segment with the U-Boot code. This
4199 happens usually with "bottom boot sector" or "top boot
4200 sector" type flash chips, which have several smaller
4201 sectors at the start or the end. For instance, such a
4202 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In
4203 such a case you would place the environment in one of the
4204 4 kB sectors - with U-Boot code before and after it. With
4205 "top boot sector" type flash chips, you would put the
4206 environment in one of the last sectors, leaving a gap
4207 between U-Boot and the environment.
4209 - CONFIG_ENV_OFFSET:
4211 Offset of environment data (variable area) to the
4212 beginning of flash memory; for instance, with bottom boot
4213 type flash chips the second sector can be used: the offset
4214 for this sector is given here.
4216 CONFIG_ENV_OFFSET is used relative to CONFIG_SYS_FLASH_BASE.
4220 This is just another way to specify the start address of
4221 the flash sector containing the environment (instead of
4224 - CONFIG_ENV_SECT_SIZE:
4226 Size of the sector containing the environment.
4229 b) Sometimes flash chips have few, equal sized, BIG sectors.
4230 In such a case you don't want to spend a whole sector for
4235 If you use this in combination with CONFIG_ENV_IS_IN_FLASH
4236 and CONFIG_ENV_SECT_SIZE, you can specify to use only a part
4237 of this flash sector for the environment. This saves
4238 memory for the RAM copy of the environment.
4240 It may also save flash memory if you decide to use this
4241 when your environment is "embedded" within U-Boot code,
4242 since then the remainder of the flash sector could be used
4243 for U-Boot code. It should be pointed out that this is
4244 STRONGLY DISCOURAGED from a robustness point of view:
4245 updating the environment in flash makes it always
4246 necessary to erase the WHOLE sector. If something goes
4247 wrong before the contents has been restored from a copy in
4248 RAM, your target system will be dead.
4250 - CONFIG_ENV_ADDR_REDUND
4251 CONFIG_ENV_SIZE_REDUND
4253 These settings describe a second storage area used to hold
4254 a redundant copy of the environment data, so that there is
4255 a valid backup copy in case there is a power failure during
4256 a "saveenv" operation.
4258 BE CAREFUL! Any changes to the flash layout, and some changes to the
4259 source code will make it necessary to adapt <board>/u-boot.lds*
4263 - CONFIG_ENV_IS_IN_NVRAM:
4265 Define this if you have some non-volatile memory device
4266 (NVRAM, battery buffered SRAM) which you want to use for the
4272 These two #defines are used to determine the memory area you
4273 want to use for environment. It is assumed that this memory
4274 can just be read and written to, without any special
4277 BE CAREFUL! The first access to the environment happens quite early
4278 in U-Boot initialization (when we try to get the setting of for the
4279 console baudrate). You *MUST* have mapped your NVRAM area then, or
4282 Please note that even with NVRAM we still use a copy of the
4283 environment in RAM: we could work on NVRAM directly, but we want to
4284 keep settings there always unmodified except somebody uses "saveenv"
4285 to save the current settings.
4288 - CONFIG_ENV_IS_IN_EEPROM:
4290 Use this if you have an EEPROM or similar serial access
4291 device and a driver for it.
4293 - CONFIG_ENV_OFFSET:
4296 These two #defines specify the offset and size of the
4297 environment area within the total memory of your EEPROM.
4299 - CONFIG_SYS_I2C_EEPROM_ADDR:
4300 If defined, specified the chip address of the EEPROM device.
4301 The default address is zero.
4303 - CONFIG_SYS_I2C_EEPROM_BUS:
4304 If defined, specified the i2c bus of the EEPROM device.
4306 - CONFIG_SYS_EEPROM_PAGE_WRITE_BITS:
4307 If defined, the number of bits used to address bytes in a
4308 single page in the EEPROM device. A 64 byte page, for example
4309 would require six bits.
4311 - CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS:
4312 If defined, the number of milliseconds to delay between
4313 page writes. The default is zero milliseconds.
4315 - CONFIG_SYS_I2C_EEPROM_ADDR_LEN:
4316 The length in bytes of the EEPROM memory array address. Note
4317 that this is NOT the chip address length!
4319 - CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW:
4320 EEPROM chips that implement "address overflow" are ones
4321 like Catalyst 24WC04/08/16 which has 9/10/11 bits of
4322 address and the extra bits end up in the "chip address" bit
4323 slots. This makes a 24WC08 (1Kbyte) chip look like four 256
4326 Note that we consider the length of the address field to
4327 still be one byte because the extra address bits are hidden
4328 in the chip address.
4330 - CONFIG_SYS_EEPROM_SIZE:
4331 The size in bytes of the EEPROM device.
4333 - CONFIG_ENV_EEPROM_IS_ON_I2C
4334 define this, if you have I2C and SPI activated, and your
4335 EEPROM, which holds the environment, is on the I2C bus.
4337 - CONFIG_I2C_ENV_EEPROM_BUS
4338 if you have an Environment on an EEPROM reached over
4339 I2C muxes, you can define here, how to reach this
4340 EEPROM. For example:
4342 #define CONFIG_I2C_ENV_EEPROM_BUS 1
4344 EEPROM which holds the environment, is reached over
4345 a pca9547 i2c mux with address 0x70, channel 3.
4347 - CONFIG_ENV_IS_IN_DATAFLASH:
4349 Define this if you have a DataFlash memory device which you
4350 want to use for the environment.
4352 - CONFIG_ENV_OFFSET:
4356 These three #defines specify the offset and size of the
4357 environment area within the total memory of your DataFlash placed
4358 at the specified address.
4360 - CONFIG_ENV_IS_IN_SPI_FLASH:
4362 Define this if you have a SPI Flash memory device which you
4363 want to use for the environment.
4365 - CONFIG_ENV_OFFSET:
4368 These two #defines specify the offset and size of the
4369 environment area within the SPI Flash. CONFIG_ENV_OFFSET must be
4370 aligned to an erase sector boundary.
4372 - CONFIG_ENV_SECT_SIZE:
4374 Define the SPI flash's sector size.
4376 - CONFIG_ENV_OFFSET_REDUND (optional):
4378 This setting describes a second storage area of CONFIG_ENV_SIZE
4379 size used to hold a redundant copy of the environment data, so
4380 that there is a valid backup copy in case there is a power failure
4381 during a "saveenv" operation. CONFIG_ENV_OFFSET_RENDUND must be
4382 aligned to an erase sector boundary.
4384 - CONFIG_ENV_SPI_BUS (optional):
4385 - CONFIG_ENV_SPI_CS (optional):
4387 Define the SPI bus and chip select. If not defined they will be 0.
4389 - CONFIG_ENV_SPI_MAX_HZ (optional):
4391 Define the SPI max work clock. If not defined then use 1MHz.
4393 - CONFIG_ENV_SPI_MODE (optional):
4395 Define the SPI work mode. If not defined then use SPI_MODE_3.
4397 - CONFIG_ENV_IS_IN_REMOTE:
4399 Define this if you have a remote memory space which you
4400 want to use for the local device's environment.
4405 These two #defines specify the address and size of the
4406 environment area within the remote memory space. The
4407 local device can get the environment from remote memory
4408 space by SRIO or PCIE links.
4410 BE CAREFUL! For some special cases, the local device can not use
4411 "saveenv" command. For example, the local device will get the
4412 environment stored in a remote NOR flash by SRIO or PCIE link,
4413 but it can not erase, write this NOR flash by SRIO or PCIE interface.
4415 - CONFIG_ENV_IS_IN_NAND:
4417 Define this if you have a NAND device which you want to use
4418 for the environment.
4420 - CONFIG_ENV_OFFSET:
4423 These two #defines specify the offset and size of the environment
4424 area within the first NAND device. CONFIG_ENV_OFFSET must be
4425 aligned to an erase block boundary.
4427 - CONFIG_ENV_OFFSET_REDUND (optional):
4429 This setting describes a second storage area of CONFIG_ENV_SIZE
4430 size used to hold a redundant copy of the environment data, so
4431 that there is a valid backup copy in case there is a power failure
4432 during a "saveenv" operation. CONFIG_ENV_OFFSET_RENDUND must be
4433 aligned to an erase block boundary.
4435 - CONFIG_ENV_RANGE (optional):
4437 Specifies the length of the region in which the environment
4438 can be written. This should be a multiple of the NAND device's
4439 block size. Specifying a range with more erase blocks than
4440 are needed to hold CONFIG_ENV_SIZE allows bad blocks within
4441 the range to be avoided.
4443 - CONFIG_ENV_OFFSET_OOB (optional):
4445 Enables support for dynamically retrieving the offset of the
4446 environment from block zero's out-of-band data. The
4447 "nand env.oob" command can be used to record this offset.
4448 Currently, CONFIG_ENV_OFFSET_REDUND is not supported when
4449 using CONFIG_ENV_OFFSET_OOB.
4451 - CONFIG_NAND_ENV_DST
4453 Defines address in RAM to which the nand_spl code should copy the
4454 environment. If redundant environment is used, it will be copied to
4455 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE.
4457 - CONFIG_ENV_IS_IN_UBI:
4459 Define this if you have an UBI volume that you want to use for the
4460 environment. This has the benefit of wear-leveling the environment
4461 accesses, which is important on NAND.
4463 - CONFIG_ENV_UBI_PART:
4465 Define this to a string that is the mtd partition containing the UBI.
4467 - CONFIG_ENV_UBI_VOLUME:
4469 Define this to the name of the volume that you want to store the
4472 - CONFIG_ENV_UBI_VOLUME_REDUND:
4474 Define this to the name of another volume to store a second copy of
4475 the environment in. This will enable redundant environments in UBI.
4476 It is assumed that both volumes are in the same MTD partition.
4478 - CONFIG_UBI_SILENCE_MSG
4479 - CONFIG_UBIFS_SILENCE_MSG
4481 You will probably want to define these to avoid a really noisy system
4482 when storing the env in UBI.
4484 - CONFIG_ENV_IS_IN_FAT:
4485 Define this if you want to use the FAT file system for the environment.
4487 - FAT_ENV_INTERFACE:
4489 Define this to a string that is the name of the block device.
4491 - FAT_ENV_DEV_AND_PART:
4493 Define this to a string to specify the partition of the device. It can
4496 "D:P", "D:0", "D", "D:" or "D:auto" (D, P are integers. And P >= 1)
4497 - "D:P": device D partition P. Error occurs if device D has no
4500 - "D" or "D:": device D partition 1 if device D has partition
4501 table, or the whole device D if has no partition
4503 - "D:auto": first partition in device D with bootable flag set.
4504 If none, first valid partition in device D. If no
4505 partition table then means device D.
4509 It's a string of the FAT file name. This file use to store the
4513 This should be defined. Otherwise it cannot save the environment file.
4515 - CONFIG_ENV_IS_IN_MMC:
4517 Define this if you have an MMC device which you want to use for the
4520 - CONFIG_SYS_MMC_ENV_DEV:
4522 Specifies which MMC device the environment is stored in.
4524 - CONFIG_SYS_MMC_ENV_PART (optional):
4526 Specifies which MMC partition the environment is stored in. If not
4527 set, defaults to partition 0, the user area. Common values might be
4528 1 (first MMC boot partition), 2 (second MMC boot partition).
4530 - CONFIG_ENV_OFFSET:
4533 These two #defines specify the offset and size of the environment
4534 area within the specified MMC device.
4536 If offset is positive (the usual case), it is treated as relative to
4537 the start of the MMC partition. If offset is negative, it is treated
4538 as relative to the end of the MMC partition. This can be useful if
4539 your board may be fitted with different MMC devices, which have
4540 different sizes for the MMC partitions, and you always want the
4541 environment placed at the very end of the partition, to leave the
4542 maximum possible space before it, to store other data.
4544 These two values are in units of bytes, but must be aligned to an
4545 MMC sector boundary.
4547 - CONFIG_ENV_OFFSET_REDUND (optional):
4549 Specifies a second storage area, of CONFIG_ENV_SIZE size, used to
4550 hold a redundant copy of the environment data. This provides a
4551 valid backup copy in case the other copy is corrupted, e.g. due
4552 to a power failure during a "saveenv" operation.
4554 This value may also be positive or negative; this is handled in the
4555 same way as CONFIG_ENV_OFFSET.
4557 This value is also in units of bytes, but must also be aligned to
4558 an MMC sector boundary.
4560 - CONFIG_ENV_SIZE_REDUND (optional):
4562 This value need not be set, even when CONFIG_ENV_OFFSET_REDUND is
4563 set. If this value is set, it must be set to the same value as
4566 - CONFIG_SYS_SPI_INIT_OFFSET
4568 Defines offset to the initial SPI buffer area in DPRAM. The
4569 area is used at an early stage (ROM part) if the environment
4570 is configured to reside in the SPI EEPROM: We need a 520 byte
4571 scratch DPRAM area. It is used between the two initialization
4572 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems
4573 to be a good choice since it makes it far enough from the
4574 start of the data area as well as from the stack pointer.
4576 Please note that the environment is read-only until the monitor
4577 has been relocated to RAM and a RAM copy of the environment has been
4578 created; also, when using EEPROM you will have to use getenv_f()
4579 until then to read environment variables.
4581 The environment is protected by a CRC32 checksum. Before the monitor
4582 is relocated into RAM, as a result of a bad CRC you will be working
4583 with the compiled-in default environment - *silently*!!! [This is
4584 necessary, because the first environment variable we need is the
4585 "baudrate" setting for the console - if we have a bad CRC, we don't
4586 have any device yet where we could complain.]
4588 Note: once the monitor has been relocated, then it will complain if
4589 the default environment is used; a new CRC is computed as soon as you
4590 use the "saveenv" command to store a valid environment.
4592 - CONFIG_SYS_FAULT_ECHO_LINK_DOWN:
4593 Echo the inverted Ethernet link state to the fault LED.
4595 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR
4596 also needs to be defined.
4598 - CONFIG_SYS_FAULT_MII_ADDR:
4599 MII address of the PHY to check for the Ethernet link state.
4601 - CONFIG_NS16550_MIN_FUNCTIONS:
4602 Define this if you desire to only have use of the NS16550_init
4603 and NS16550_putc functions for the serial driver located at
4604 drivers/serial/ns16550.c. This option is useful for saving
4605 space for already greatly restricted images, including but not
4606 limited to NAND_SPL configurations.
4608 - CONFIG_DISPLAY_BOARDINFO
4609 Display information about the board that U-Boot is running on
4610 when U-Boot starts up. The board function checkboard() is called
4613 - CONFIG_DISPLAY_BOARDINFO_LATE
4614 Similar to the previous option, but display this information
4615 later, once stdio is running and output goes to the LCD, if
4618 - CONFIG_BOARD_SIZE_LIMIT:
4619 Maximum size of the U-Boot image. When defined, the
4620 build system checks that the actual size does not
4623 Low Level (hardware related) configuration options:
4624 ---------------------------------------------------
4626 - CONFIG_SYS_CACHELINE_SIZE:
4627 Cache Line Size of the CPU.
4629 - CONFIG_SYS_DEFAULT_IMMR:
4630 Default address of the IMMR after system reset.
4632 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU,
4633 and RPXsuper) to be able to adjust the position of
4634 the IMMR register after a reset.
4636 - CONFIG_SYS_CCSRBAR_DEFAULT:
4637 Default (power-on reset) physical address of CCSR on Freescale
4640 - CONFIG_SYS_CCSRBAR:
4641 Virtual address of CCSR. On a 32-bit build, this is typically
4642 the same value as CONFIG_SYS_CCSRBAR_DEFAULT.
4644 CONFIG_SYS_DEFAULT_IMMR must also be set to this value,
4645 for cross-platform code that uses that macro instead.
4647 - CONFIG_SYS_CCSRBAR_PHYS:
4648 Physical address of CCSR. CCSR can be relocated to a new
4649 physical address, if desired. In this case, this macro should
4650 be set to that address. Otherwise, it should be set to the
4651 same value as CONFIG_SYS_CCSRBAR_DEFAULT. For example, CCSR
4652 is typically relocated on 36-bit builds. It is recommended
4653 that this macro be defined via the _HIGH and _LOW macros:
4655 #define CONFIG_SYS_CCSRBAR_PHYS ((CONFIG_SYS_CCSRBAR_PHYS_HIGH
4656 * 1ull) << 32 | CONFIG_SYS_CCSRBAR_PHYS_LOW)
4658 - CONFIG_SYS_CCSRBAR_PHYS_HIGH:
4659 Bits 33-36 of CONFIG_SYS_CCSRBAR_PHYS. This value is typically
4660 either 0 (32-bit build) or 0xF (36-bit build). This macro is
4661 used in assembly code, so it must not contain typecasts or
4662 integer size suffixes (e.g. "ULL").
4664 - CONFIG_SYS_CCSRBAR_PHYS_LOW:
4665 Lower 32-bits of CONFIG_SYS_CCSRBAR_PHYS. This macro is
4666 used in assembly code, so it must not contain typecasts or
4667 integer size suffixes (e.g. "ULL").
4669 - CONFIG_SYS_CCSR_DO_NOT_RELOCATE:
4670 If this macro is defined, then CONFIG_SYS_CCSRBAR_PHYS will be
4671 forced to a value that ensures that CCSR is not relocated.
4673 - Floppy Disk Support:
4674 CONFIG_SYS_FDC_DRIVE_NUMBER
4676 the default drive number (default value 0)
4678 CONFIG_SYS_ISA_IO_STRIDE
4680 defines the spacing between FDC chipset registers
4683 CONFIG_SYS_ISA_IO_OFFSET
4685 defines the offset of register from address. It
4686 depends on which part of the data bus is connected to
4687 the FDC chipset. (default value 0)
4689 If CONFIG_SYS_ISA_IO_STRIDE CONFIG_SYS_ISA_IO_OFFSET and
4690 CONFIG_SYS_FDC_DRIVE_NUMBER are undefined, they take their
4693 if CONFIG_SYS_FDC_HW_INIT is defined, then the function
4694 fdc_hw_init() is called at the beginning of the FDC
4695 setup. fdc_hw_init() must be provided by the board
4696 source code. It is used to make hardware-dependent
4700 Most IDE controllers were designed to be connected with PCI
4701 interface. Only few of them were designed for AHB interface.
4702 When software is doing ATA command and data transfer to
4703 IDE devices through IDE-AHB controller, some additional
4704 registers accessing to these kind of IDE-AHB controller
4707 - CONFIG_SYS_IMMR: Physical address of the Internal Memory.
4708 DO NOT CHANGE unless you know exactly what you're
4709 doing! (11-4) [MPC8xx/82xx systems only]
4711 - CONFIG_SYS_INIT_RAM_ADDR:
4713 Start address of memory area that can be used for
4714 initial data and stack; please note that this must be
4715 writable memory that is working WITHOUT special
4716 initialization, i. e. you CANNOT use normal RAM which
4717 will become available only after programming the
4718 memory controller and running certain initialization
4721 U-Boot uses the following memory types:
4722 - MPC8xx and MPC8260: IMMR (internal memory of the CPU)
4723 - MPC824X: data cache
4724 - PPC4xx: data cache
4726 - CONFIG_SYS_GBL_DATA_OFFSET:
4728 Offset of the initial data structure in the memory
4729 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually
4730 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial
4731 data is located at the end of the available space
4732 (sometimes written as (CONFIG_SYS_INIT_RAM_SIZE -
4733 CONFIG_SYS_INIT_DATA_SIZE), and the initial stack is just
4734 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR +
4735 CONFIG_SYS_GBL_DATA_OFFSET) downward.
4738 On the MPC824X (or other systems that use the data
4739 cache for initial memory) the address chosen for
4740 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must
4741 point to an otherwise UNUSED address space between
4742 the top of RAM and the start of the PCI space.
4744 - CONFIG_SYS_SIUMCR: SIU Module Configuration (11-6)
4746 - CONFIG_SYS_SYPCR: System Protection Control (11-9)
4748 - CONFIG_SYS_TBSCR: Time Base Status and Control (11-26)
4750 - CONFIG_SYS_PISCR: Periodic Interrupt Status and Control (11-31)
4752 - CONFIG_SYS_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30)
4754 - CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27)
4756 - CONFIG_SYS_OR_TIMING_SDRAM:
4759 - CONFIG_SYS_MAMR_PTA:
4760 periodic timer for refresh
4762 - CONFIG_SYS_DER: Debug Event Register (37-47)
4764 - FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM,
4765 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP,
4766 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM,
4767 CONFIG_SYS_BR1_PRELIM:
4768 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
4770 - SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
4771 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM,
4772 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM:
4773 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
4775 - CONFIG_SYS_MAMR_PTA, CONFIG_SYS_MPTPR_2BK_4K, CONFIG_SYS_MPTPR_1BK_4K, CONFIG_SYS_MPTPR_2BK_8K,
4776 CONFIG_SYS_MPTPR_1BK_8K, CONFIG_SYS_MAMR_8COL, CONFIG_SYS_MAMR_9COL:
4777 Machine Mode Register and Memory Periodic Timer
4778 Prescaler definitions (SDRAM timing)
4780 - CONFIG_SYS_I2C_UCODE_PATCH, CONFIG_SYS_I2C_DPMEM_OFFSET [0x1FC0]:
4781 enable I2C microcode relocation patch (MPC8xx);
4782 define relocation offset in DPRAM [DSP2]
4784 - CONFIG_SYS_SMC_UCODE_PATCH, CONFIG_SYS_SMC_DPMEM_OFFSET [0x1FC0]:
4785 enable SMC microcode relocation patch (MPC8xx);
4786 define relocation offset in DPRAM [SMC1]
4788 - CONFIG_SYS_SPI_UCODE_PATCH, CONFIG_SYS_SPI_DPMEM_OFFSET [0x1FC0]:
4789 enable SPI microcode relocation patch (MPC8xx);
4790 define relocation offset in DPRAM [SCC4]
4792 - CONFIG_SYS_USE_OSCCLK:
4793 Use OSCM clock mode on MBX8xx board. Be careful,
4794 wrong setting might damage your board. Read
4795 doc/README.MBX before setting this variable!
4797 - CONFIG_SYS_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only)
4798 Offset of the bootmode word in DPRAM used by post
4799 (Power On Self Tests). This definition overrides
4800 #define'd default value in commproc.h resp.
4803 - CONFIG_SYS_PCI_SLV_MEM_LOCAL, CONFIG_SYS_PCI_SLV_MEM_BUS, CONFIG_SYS_PICMR0_MASK_ATTRIB,
4804 CONFIG_SYS_PCI_MSTR0_LOCAL, CONFIG_SYS_PCIMSK0_MASK, CONFIG_SYS_PCI_MSTR1_LOCAL,
4805 CONFIG_SYS_PCIMSK1_MASK, CONFIG_SYS_PCI_MSTR_MEM_LOCAL, CONFIG_SYS_PCI_MSTR_MEM_BUS,
4806 CONFIG_SYS_CPU_PCI_MEM_START, CONFIG_SYS_PCI_MSTR_MEM_SIZE, CONFIG_SYS_POCMR0_MASK_ATTRIB,
4807 CONFIG_SYS_PCI_MSTR_MEMIO_LOCAL, CONFIG_SYS_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START,
4808 CONFIG_SYS_PCI_MSTR_MEMIO_SIZE, CONFIG_SYS_POCMR1_MASK_ATTRIB, CONFIG_SYS_PCI_MSTR_IO_LOCAL,
4809 CONFIG_SYS_PCI_MSTR_IO_BUS, CONFIG_SYS_CPU_PCI_IO_START, CONFIG_SYS_PCI_MSTR_IO_SIZE,
4810 CONFIG_SYS_POCMR2_MASK_ATTRIB: (MPC826x only)
4811 Overrides the default PCI memory map in arch/powerpc/cpu/mpc8260/pci.c if set.
4813 - CONFIG_PCI_DISABLE_PCIE:
4814 Disable PCI-Express on systems where it is supported but not
4817 - CONFIG_PCI_ENUM_ONLY
4818 Only scan through and get the devices on the buses.
4819 Don't do any setup work, presumably because someone or
4820 something has already done it, and we don't need to do it
4821 a second time. Useful for platforms that are pre-booted
4822 by coreboot or similar.
4824 - CONFIG_PCI_INDIRECT_BRIDGE:
4825 Enable support for indirect PCI bridges.
4828 Chip has SRIO or not
4831 Board has SRIO 1 port available
4834 Board has SRIO 2 port available
4836 - CONFIG_SRIO_PCIE_BOOT_MASTER
4837 Board can support master function for Boot from SRIO and PCIE
4839 - CONFIG_SYS_SRIOn_MEM_VIRT:
4840 Virtual Address of SRIO port 'n' memory region
4842 - CONFIG_SYS_SRIOn_MEM_PHYS:
4843 Physical Address of SRIO port 'n' memory region
4845 - CONFIG_SYS_SRIOn_MEM_SIZE:
4846 Size of SRIO port 'n' memory region
4848 - CONFIG_SYS_NAND_BUSWIDTH_16BIT
4849 Defined to tell the NAND controller that the NAND chip is using
4851 Not all NAND drivers use this symbol.
4852 Example of drivers that use it:
4853 - drivers/mtd/nand/ndfc.c
4854 - drivers/mtd/nand/mxc_nand.c
4856 - CONFIG_SYS_NDFC_EBC0_CFG
4857 Sets the EBC0_CFG register for the NDFC. If not defined
4858 a default value will be used.
4861 Get DDR timing information from an I2C EEPROM. Common
4862 with pluggable memory modules such as SODIMMs
4865 I2C address of the SPD EEPROM
4867 - CONFIG_SYS_SPD_BUS_NUM
4868 If SPD EEPROM is on an I2C bus other than the first
4869 one, specify here. Note that the value must resolve
4870 to something your driver can deal with.
4872 - CONFIG_SYS_DDR_RAW_TIMING
4873 Get DDR timing information from other than SPD. Common with
4874 soldered DDR chips onboard without SPD. DDR raw timing
4875 parameters are extracted from datasheet and hard-coded into
4876 header files or board specific files.
4878 - CONFIG_FSL_DDR_INTERACTIVE
4879 Enable interactive DDR debugging. See doc/README.fsl-ddr.
4881 - CONFIG_FSL_DDR_SYNC_REFRESH
4882 Enable sync of refresh for multiple controllers.
4884 - CONFIG_FSL_DDR_BIST
4885 Enable built-in memory test for Freescale DDR controllers.
4887 - CONFIG_SYS_83XX_DDR_USES_CS0
4888 Only for 83xx systems. If specified, then DDR should
4889 be configured using CS0 and CS1 instead of CS2 and CS3.
4891 - CONFIG_ETHER_ON_FEC[12]
4892 Define to enable FEC[12] on a 8xx series processor.
4894 - CONFIG_FEC[12]_PHY
4895 Define to the hardcoded PHY address which corresponds
4896 to the given FEC; i. e.
4897 #define CONFIG_FEC1_PHY 4
4898 means that the PHY with address 4 is connected to FEC1
4900 When set to -1, means to probe for first available.
4902 - CONFIG_FEC[12]_PHY_NORXERR
4903 The PHY does not have a RXERR line (RMII only).
4904 (so program the FEC to ignore it).
4907 Enable RMII mode for all FECs.
4908 Note that this is a global option, we can't
4909 have one FEC in standard MII mode and another in RMII mode.
4911 - CONFIG_CRC32_VERIFY
4912 Add a verify option to the crc32 command.
4915 => crc32 -v <address> <count> <crc32>
4917 Where address/count indicate a memory area
4918 and crc32 is the correct crc32 which the
4922 Add the "loopw" memory command. This only takes effect if
4923 the memory commands are activated globally (CONFIG_CMD_MEM).
4926 Add the "mdc" and "mwc" memory commands. These are cyclic
4931 This command will print 4 bytes (10,11,12,13) each 500 ms.
4933 => mwc.l 100 12345678 10
4934 This command will write 12345678 to address 100 all 10 ms.
4936 This only takes effect if the memory commands are activated
4937 globally (CONFIG_CMD_MEM).
4939 - CONFIG_SKIP_LOWLEVEL_INIT
4940 [ARM, NDS32, MIPS only] If this variable is defined, then certain
4941 low level initializations (like setting up the memory
4942 controller) are omitted and/or U-Boot does not
4943 relocate itself into RAM.
4945 Normally this variable MUST NOT be defined. The only
4946 exception is when U-Boot is loaded (to RAM) by some
4947 other boot loader or by a debugger which performs
4948 these initializations itself.
4951 Modifies the behaviour of start.S when compiling a loader
4952 that is executed before the actual U-Boot. E.g. when
4953 compiling a NAND SPL.
4956 Modifies the behaviour of start.S when compiling a loader
4957 that is executed after the SPL and before the actual U-Boot.
4958 It is loaded by the SPL.
4960 - CONFIG_SYS_MPC85XX_NO_RESETVEC
4961 Only for 85xx systems. If this variable is specified, the section
4962 .resetvec is not kept and the section .bootpg is placed in the
4963 previous 4k of the .text section.
4965 - CONFIG_ARCH_MAP_SYSMEM
4966 Generally U-Boot (and in particular the md command) uses
4967 effective address. It is therefore not necessary to regard
4968 U-Boot address as virtual addresses that need to be translated
4969 to physical addresses. However, sandbox requires this, since
4970 it maintains its own little RAM buffer which contains all
4971 addressable memory. This option causes some memory accesses
4972 to be mapped through map_sysmem() / unmap_sysmem().
4974 - CONFIG_USE_ARCH_MEMCPY
4975 CONFIG_USE_ARCH_MEMSET
4976 If these options are used a optimized version of memcpy/memset will
4977 be used if available. These functions may be faster under some
4978 conditions but may increase the binary size.
4980 - CONFIG_X86_RESET_VECTOR
4981 If defined, the x86 reset vector code is included. This is not
4982 needed when U-Boot is running from Coreboot.
4985 Defines the MPU clock speed (in MHz).
4987 NOTE : currently only supported on AM335x platforms.
4989 - CONFIG_SPL_AM33XX_ENABLE_RTC32K_OSC:
4990 Enables the RTC32K OSC on AM33xx based plattforms
4992 - CONFIG_SYS_NAND_NO_SUBPAGE_WRITE
4993 Option to disable subpage write in NAND driver
4994 driver that uses this:
4995 drivers/mtd/nand/davinci_nand.c
4997 Freescale QE/FMAN Firmware Support:
4998 -----------------------------------
5000 The Freescale QUICCEngine (QE) and Frame Manager (FMAN) both support the
5001 loading of "firmware", which is encoded in the QE firmware binary format.
5002 This firmware often needs to be loaded during U-Boot booting, so macros
5003 are used to identify the storage device (NOR flash, SPI, etc) and the address
5006 - CONFIG_SYS_FMAN_FW_ADDR
5007 The address in the storage device where the FMAN microcode is located. The
5008 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
5011 - CONFIG_SYS_QE_FW_ADDR
5012 The address in the storage device where the QE microcode is located. The
5013 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
5016 - CONFIG_SYS_QE_FMAN_FW_LENGTH
5017 The maximum possible size of the firmware. The firmware binary format
5018 has a field that specifies the actual size of the firmware, but it
5019 might not be possible to read any part of the firmware unless some
5020 local storage is allocated to hold the entire firmware first.
5022 - CONFIG_SYS_QE_FMAN_FW_IN_NOR
5023 Specifies that QE/FMAN firmware is located in NOR flash, mapped as
5024 normal addressable memory via the LBC. CONFIG_SYS_FMAN_FW_ADDR is the
5025 virtual address in NOR flash.
5027 - CONFIG_SYS_QE_FMAN_FW_IN_NAND
5028 Specifies that QE/FMAN firmware is located in NAND flash.
5029 CONFIG_SYS_FMAN_FW_ADDR is the offset within NAND flash.
5031 - CONFIG_SYS_QE_FMAN_FW_IN_MMC
5032 Specifies that QE/FMAN firmware is located on the primary SD/MMC
5033 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
5035 - CONFIG_SYS_QE_FMAN_FW_IN_SPIFLASH
5036 Specifies that QE/FMAN firmware is located on the primary SPI
5037 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
5039 - CONFIG_SYS_QE_FMAN_FW_IN_REMOTE
5040 Specifies that QE/FMAN firmware is located in the remote (master)
5041 memory space. CONFIG_SYS_FMAN_FW_ADDR is a virtual address which
5042 can be mapped from slave TLB->slave LAW->slave SRIO or PCIE outbound
5043 window->master inbound window->master LAW->the ucode address in
5044 master's memory space.
5046 Freescale Layerscape Management Complex Firmware Support:
5047 ---------------------------------------------------------
5048 The Freescale Layerscape Management Complex (MC) supports the loading of
5050 This firmware often needs to be loaded during U-Boot booting, so macros
5051 are used to identify the storage device (NOR flash, SPI, etc) and the address
5054 - CONFIG_FSL_MC_ENET
5055 Enable the MC driver for Layerscape SoCs.
5057 - CONFIG_SYS_LS_MC_FW_ADDR
5058 The address in the storage device where the firmware is located. The
5059 meaning of this address depends on which CONFIG_SYS_LS_MC_FW_IN_xxx macro
5062 - CONFIG_SYS_LS_MC_FW_LENGTH
5063 The maximum possible size of the firmware. The firmware binary format
5064 has a field that specifies the actual size of the firmware, but it
5065 might not be possible to read any part of the firmware unless some
5066 local storage is allocated to hold the entire firmware first.
5068 - CONFIG_SYS_LS_MC_FW_IN_NOR
5069 Specifies that MC firmware is located in NOR flash, mapped as
5070 normal addressable memory via the LBC. CONFIG_SYS_LS_MC_FW_ADDR is the
5071 virtual address in NOR flash.
5073 Building the Software:
5074 ======================
5076 Building U-Boot has been tested in several native build environments
5077 and in many different cross environments. Of course we cannot support
5078 all possibly existing versions of cross development tools in all
5079 (potentially obsolete) versions. In case of tool chain problems we
5080 recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK)
5081 which is extensively used to build and test U-Boot.
5083 If you are not using a native environment, it is assumed that you
5084 have GNU cross compiling tools available in your path. In this case,
5085 you must set the environment variable CROSS_COMPILE in your shell.
5086 Note that no changes to the Makefile or any other source files are
5087 necessary. For example using the ELDK on a 4xx CPU, please enter:
5089 $ CROSS_COMPILE=ppc_4xx-
5090 $ export CROSS_COMPILE
5092 Note: If you wish to generate Windows versions of the utilities in
5093 the tools directory you can use the MinGW toolchain
5094 (http://www.mingw.org). Set your HOST tools to the MinGW
5095 toolchain and execute 'make tools'. For example:
5097 $ make HOSTCC=i586-mingw32msvc-gcc HOSTSTRIP=i586-mingw32msvc-strip tools
5099 Binaries such as tools/mkimage.exe will be created which can
5100 be executed on computers running Windows.
5102 U-Boot is intended to be simple to build. After installing the
5103 sources you must configure U-Boot for one specific board type. This
5108 where "NAME_defconfig" is the name of one of the existing configu-
5109 rations; see boards.cfg for supported names.
5111 Note: for some board special configuration names may exist; check if
5112 additional information is available from the board vendor; for
5113 instance, the TQM823L systems are available without (standard)
5114 or with LCD support. You can select such additional "features"
5115 when choosing the configuration, i. e.
5117 make TQM823L_defconfig
5118 - will configure for a plain TQM823L, i. e. no LCD support
5120 make TQM823L_LCD_defconfig
5121 - will configure for a TQM823L with U-Boot console on LCD
5126 Finally, type "make all", and you should get some working U-Boot
5127 images ready for download to / installation on your system:
5129 - "u-boot.bin" is a raw binary image
5130 - "u-boot" is an image in ELF binary format
5131 - "u-boot.srec" is in Motorola S-Record format
5133 By default the build is performed locally and the objects are saved
5134 in the source directory. One of the two methods can be used to change
5135 this behavior and build U-Boot to some external directory:
5137 1. Add O= to the make command line invocations:
5139 make O=/tmp/build distclean
5140 make O=/tmp/build NAME_defconfig
5141 make O=/tmp/build all
5143 2. Set environment variable KBUILD_OUTPUT to point to the desired location:
5145 export KBUILD_OUTPUT=/tmp/build
5150 Note that the command line "O=" setting overrides the KBUILD_OUTPUT environment
5154 Please be aware that the Makefiles assume you are using GNU make, so
5155 for instance on NetBSD you might need to use "gmake" instead of
5159 If the system board that you have is not listed, then you will need
5160 to port U-Boot to your hardware platform. To do this, follow these
5163 1. Add a new configuration option for your board to the toplevel
5164 "boards.cfg" file, using the existing entries as examples.
5165 Follow the instructions there to keep the boards in order.
5166 2. Create a new directory to hold your board specific code. Add any
5167 files you need. In your board directory, you will need at least
5168 the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds".
5169 3. Create a new configuration file "include/configs/<board>.h" for
5171 3. If you're porting U-Boot to a new CPU, then also create a new
5172 directory to hold your CPU specific code. Add any files you need.
5173 4. Run "make <board>_defconfig" with your new name.
5174 5. Type "make", and you should get a working "u-boot.srec" file
5175 to be installed on your target system.
5176 6. Debug and solve any problems that might arise.
5177 [Of course, this last step is much harder than it sounds.]
5180 Testing of U-Boot Modifications, Ports to New Hardware, etc.:
5181 ==============================================================
5183 If you have modified U-Boot sources (for instance added a new board
5184 or support for new devices, a new CPU, etc.) you are expected to
5185 provide feedback to the other developers. The feedback normally takes
5186 the form of a "patch", i. e. a context diff against a certain (latest
5187 official or latest in the git repository) version of U-Boot sources.
5189 But before you submit such a patch, please verify that your modifi-
5190 cation did not break existing code. At least make sure that *ALL* of
5191 the supported boards compile WITHOUT ANY compiler warnings. To do so,
5192 just run the "MAKEALL" script, which will configure and build U-Boot
5193 for ALL supported system. Be warned, this will take a while. You can
5194 select which (cross) compiler to use by passing a `CROSS_COMPILE'
5195 environment variable to the script, i. e. to use the ELDK cross tools
5198 CROSS_COMPILE=ppc_8xx- MAKEALL
5200 or to build on a native PowerPC system you can type
5202 CROSS_COMPILE=' ' MAKEALL
5204 When using the MAKEALL script, the default behaviour is to build
5205 U-Boot in the source directory. This location can be changed by
5206 setting the BUILD_DIR environment variable. Also, for each target
5207 built, the MAKEALL script saves two log files (<target>.ERR and
5208 <target>.MAKEALL) in the <source dir>/LOG directory. This default
5209 location can be changed by setting the MAKEALL_LOGDIR environment
5210 variable. For example:
5212 export BUILD_DIR=/tmp/build
5213 export MAKEALL_LOGDIR=/tmp/log
5214 CROSS_COMPILE=ppc_8xx- MAKEALL
5216 With the above settings build objects are saved in the /tmp/build,
5217 log files are saved in the /tmp/log and the source tree remains clean
5218 during the whole build process.
5221 See also "U-Boot Porting Guide" below.
5224 Monitor Commands - Overview:
5225 ============================
5227 go - start application at address 'addr'
5228 run - run commands in an environment variable
5229 bootm - boot application image from memory
5230 bootp - boot image via network using BootP/TFTP protocol
5231 bootz - boot zImage from memory
5232 tftpboot- boot image via network using TFTP protocol
5233 and env variables "ipaddr" and "serverip"
5234 (and eventually "gatewayip")
5235 tftpput - upload a file via network using TFTP protocol
5236 rarpboot- boot image via network using RARP/TFTP protocol
5237 diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
5238 loads - load S-Record file over serial line
5239 loadb - load binary file over serial line (kermit mode)
5241 mm - memory modify (auto-incrementing)
5242 nm - memory modify (constant address)
5243 mw - memory write (fill)
5245 cmp - memory compare
5246 crc32 - checksum calculation
5247 i2c - I2C sub-system
5248 sspi - SPI utility commands
5249 base - print or set address offset
5250 printenv- print environment variables
5251 setenv - set environment variables
5252 saveenv - save environment variables to persistent storage
5253 protect - enable or disable FLASH write protection
5254 erase - erase FLASH memory
5255 flinfo - print FLASH memory information
5256 nand - NAND memory operations (see doc/README.nand)
5257 bdinfo - print Board Info structure
5258 iminfo - print header information for application image
5259 coninfo - print console devices and informations
5260 ide - IDE sub-system
5261 loop - infinite loop on address range
5262 loopw - infinite write loop on address range
5263 mtest - simple RAM test
5264 icache - enable or disable instruction cache
5265 dcache - enable or disable data cache
5266 reset - Perform RESET of the CPU
5267 echo - echo args to console
5268 version - print monitor version
5269 help - print online help
5270 ? - alias for 'help'
5273 Monitor Commands - Detailed Description:
5274 ========================================
5278 For now: just type "help <command>".
5281 Environment Variables:
5282 ======================
5284 U-Boot supports user configuration using Environment Variables which
5285 can be made persistent by saving to Flash memory.
5287 Environment Variables are set using "setenv", printed using
5288 "printenv", and saved to Flash using "saveenv". Using "setenv"
5289 without a value can be used to delete a variable from the
5290 environment. As long as you don't save the environment you are
5291 working with an in-memory copy. In case the Flash area containing the
5292 environment is erased by accident, a default environment is provided.
5294 Some configuration options can be set using Environment Variables.
5296 List of environment variables (most likely not complete):
5298 baudrate - see CONFIG_BAUDRATE
5300 bootdelay - see CONFIG_BOOTDELAY
5302 bootcmd - see CONFIG_BOOTCOMMAND
5304 bootargs - Boot arguments when booting an RTOS image
5306 bootfile - Name of the image to load with TFTP
5308 bootm_low - Memory range available for image processing in the bootm
5309 command can be restricted. This variable is given as
5310 a hexadecimal number and defines lowest address allowed
5311 for use by the bootm command. See also "bootm_size"
5312 environment variable. Address defined by "bootm_low" is
5313 also the base of the initial memory mapping for the Linux
5314 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ and
5317 bootm_mapsize - Size of the initial memory mapping for the Linux kernel.
5318 This variable is given as a hexadecimal number and it
5319 defines the size of the memory region starting at base
5320 address bootm_low that is accessible by the Linux kernel
5321 during early boot. If unset, CONFIG_SYS_BOOTMAPSZ is used
5322 as the default value if it is defined, and bootm_size is
5325 bootm_size - Memory range available for image processing in the bootm
5326 command can be restricted. This variable is given as
5327 a hexadecimal number and defines the size of the region
5328 allowed for use by the bootm command. See also "bootm_low"
5329 environment variable.
5331 updatefile - Location of the software update file on a TFTP server, used
5332 by the automatic software update feature. Please refer to
5333 documentation in doc/README.update for more details.
5335 autoload - if set to "no" (any string beginning with 'n'),
5336 "bootp" will just load perform a lookup of the
5337 configuration from the BOOTP server, but not try to
5338 load any image using TFTP
5340 autostart - if set to "yes", an image loaded using the "bootp",
5341 "rarpboot", "tftpboot" or "diskboot" commands will
5342 be automatically started (by internally calling
5345 If set to "no", a standalone image passed to the
5346 "bootm" command will be copied to the load address
5347 (and eventually uncompressed), but NOT be started.
5348 This can be used to load and uncompress arbitrary
5351 fdt_high - if set this restricts the maximum address that the
5352 flattened device tree will be copied into upon boot.
5353 For example, if you have a system with 1 GB memory
5354 at physical address 0x10000000, while Linux kernel
5355 only recognizes the first 704 MB as low memory, you
5356 may need to set fdt_high as 0x3C000000 to have the
5357 device tree blob be copied to the maximum address
5358 of the 704 MB low memory, so that Linux kernel can
5359 access it during the boot procedure.
5361 If this is set to the special value 0xFFFFFFFF then
5362 the fdt will not be copied at all on boot. For this
5363 to work it must reside in writable memory, have
5364 sufficient padding on the end of it for u-boot to
5365 add the information it needs into it, and the memory
5366 must be accessible by the kernel.
5368 fdtcontroladdr- if set this is the address of the control flattened
5369 device tree used by U-Boot when CONFIG_OF_CONTROL is
5372 i2cfast - (PPC405GP|PPC405EP only)
5373 if set to 'y' configures Linux I2C driver for fast
5374 mode (400kHZ). This environment variable is used in
5375 initialization code. So, for changes to be effective
5376 it must be saved and board must be reset.
5378 initrd_high - restrict positioning of initrd images:
5379 If this variable is not set, initrd images will be
5380 copied to the highest possible address in RAM; this
5381 is usually what you want since it allows for
5382 maximum initrd size. If for some reason you want to
5383 make sure that the initrd image is loaded below the
5384 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment
5385 variable to a value of "no" or "off" or "0".
5386 Alternatively, you can set it to a maximum upper
5387 address to use (U-Boot will still check that it
5388 does not overwrite the U-Boot stack and data).
5390 For instance, when you have a system with 16 MB
5391 RAM, and want to reserve 4 MB from use by Linux,
5392 you can do this by adding "mem=12M" to the value of
5393 the "bootargs" variable. However, now you must make
5394 sure that the initrd image is placed in the first
5395 12 MB as well - this can be done with
5397 setenv initrd_high 00c00000
5399 If you set initrd_high to 0xFFFFFFFF, this is an
5400 indication to U-Boot that all addresses are legal
5401 for the Linux kernel, including addresses in flash
5402 memory. In this case U-Boot will NOT COPY the
5403 ramdisk at all. This may be useful to reduce the
5404 boot time on your system, but requires that this
5405 feature is supported by your Linux kernel.
5407 ipaddr - IP address; needed for tftpboot command
5409 loadaddr - Default load address for commands like "bootp",
5410 "rarpboot", "tftpboot", "loadb" or "diskboot"
5412 loads_echo - see CONFIG_LOADS_ECHO
5414 serverip - TFTP server IP address; needed for tftpboot command
5416 bootretry - see CONFIG_BOOT_RETRY_TIME
5418 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
5420 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
5422 ethprime - controls which interface is used first.
5424 ethact - controls which interface is currently active.
5425 For example you can do the following
5427 => setenv ethact FEC
5428 => ping 192.168.0.1 # traffic sent on FEC
5429 => setenv ethact SCC
5430 => ping 10.0.0.1 # traffic sent on SCC
5432 ethrotate - When set to "no" U-Boot does not go through all
5433 available network interfaces.
5434 It just stays at the currently selected interface.
5436 netretry - When set to "no" each network operation will
5437 either succeed or fail without retrying.
5438 When set to "once" the network operation will
5439 fail when all the available network interfaces
5440 are tried once without success.
5441 Useful on scripts which control the retry operation
5444 npe_ucode - set load address for the NPE microcode
5446 silent_linux - If set then Linux will be told to boot silently, by
5447 changing the console to be empty. If "yes" it will be
5448 made silent. If "no" it will not be made silent. If
5449 unset, then it will be made silent if the U-Boot console
5452 tftpsrcport - If this is set, the value is used for TFTP's
5455 tftpdstport - If this is set, the value is used for TFTP's UDP
5456 destination port instead of the Well Know Port 69.
5458 tftpblocksize - Block size to use for TFTP transfers; if not set,
5459 we use the TFTP server's default block size
5461 tftptimeout - Retransmission timeout for TFTP packets (in milli-
5462 seconds, minimum value is 1000 = 1 second). Defines
5463 when a packet is considered to be lost so it has to
5464 be retransmitted. The default is 5000 = 5 seconds.
5465 Lowering this value may make downloads succeed
5466 faster in networks with high packet loss rates or
5467 with unreliable TFTP servers.
5469 vlan - When set to a value < 4095 the traffic over
5470 Ethernet is encapsulated/received over 802.1q
5473 The following image location variables contain the location of images
5474 used in booting. The "Image" column gives the role of the image and is
5475 not an environment variable name. The other columns are environment
5476 variable names. "File Name" gives the name of the file on a TFTP
5477 server, "RAM Address" gives the location in RAM the image will be
5478 loaded to, and "Flash Location" gives the image's address in NOR
5479 flash or offset in NAND flash.
5481 *Note* - these variables don't have to be defined for all boards, some
5482 boards currently use other variables for these purposes, and some
5483 boards use these variables for other purposes.
5485 Image File Name RAM Address Flash Location
5486 ----- --------- ----------- --------------
5487 u-boot u-boot u-boot_addr_r u-boot_addr
5488 Linux kernel bootfile kernel_addr_r kernel_addr
5489 device tree blob fdtfile fdt_addr_r fdt_addr
5490 ramdisk ramdiskfile ramdisk_addr_r ramdisk_addr
5492 The following environment variables may be used and automatically
5493 updated by the network boot commands ("bootp" and "rarpboot"),
5494 depending the information provided by your boot server:
5496 bootfile - see above
5497 dnsip - IP address of your Domain Name Server
5498 dnsip2 - IP address of your secondary Domain Name Server
5499 gatewayip - IP address of the Gateway (Router) to use
5500 hostname - Target hostname
5502 netmask - Subnet Mask
5503 rootpath - Pathname of the root filesystem on the NFS server
5504 serverip - see above
5507 There are two special Environment Variables:
5509 serial# - contains hardware identification information such
5510 as type string and/or serial number
5511 ethaddr - Ethernet address
5513 These variables can be set only once (usually during manufacturing of
5514 the board). U-Boot refuses to delete or overwrite these variables
5515 once they have been set once.
5518 Further special Environment Variables:
5520 ver - Contains the U-Boot version string as printed
5521 with the "version" command. This variable is
5522 readonly (see CONFIG_VERSION_VARIABLE).
5525 Please note that changes to some configuration parameters may take
5526 only effect after the next boot (yes, that's just like Windoze :-).
5529 Callback functions for environment variables:
5530 ---------------------------------------------
5532 For some environment variables, the behavior of u-boot needs to change
5533 when their values are changed. This functionality allows functions to
5534 be associated with arbitrary variables. On creation, overwrite, or
5535 deletion, the callback will provide the opportunity for some side
5536 effect to happen or for the change to be rejected.
5538 The callbacks are named and associated with a function using the
5539 U_BOOT_ENV_CALLBACK macro in your board or driver code.
5541 These callbacks are associated with variables in one of two ways. The
5542 static list can be added to by defining CONFIG_ENV_CALLBACK_LIST_STATIC
5543 in the board configuration to a string that defines a list of
5544 associations. The list must be in the following format:
5546 entry = variable_name[:callback_name]
5549 If the callback name is not specified, then the callback is deleted.
5550 Spaces are also allowed anywhere in the list.
5552 Callbacks can also be associated by defining the ".callbacks" variable
5553 with the same list format above. Any association in ".callbacks" will
5554 override any association in the static list. You can define
5555 CONFIG_ENV_CALLBACK_LIST_DEFAULT to a list (string) to define the
5556 ".callbacks" environment variable in the default or embedded environment.
5558 If CONFIG_REGEX is defined, the variable_name above is evaluated as a
5559 regular expression. This allows multiple variables to be connected to
5560 the same callback without explicitly listing them all out.
5563 Command Line Parsing:
5564 =====================
5566 There are two different command line parsers available with U-Boot:
5567 the old "simple" one, and the much more powerful "hush" shell:
5569 Old, simple command line parser:
5570 --------------------------------
5572 - supports environment variables (through setenv / saveenv commands)
5573 - several commands on one line, separated by ';'
5574 - variable substitution using "... ${name} ..." syntax
5575 - special characters ('$', ';') can be escaped by prefixing with '\',
5577 setenv bootcmd bootm \${address}
5578 - You can also escape text by enclosing in single apostrophes, for example:
5579 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
5584 - similar to Bourne shell, with control structures like
5585 if...then...else...fi, for...do...done; while...do...done,
5586 until...do...done, ...
5587 - supports environment ("global") variables (through setenv / saveenv
5588 commands) and local shell variables (through standard shell syntax
5589 "name=value"); only environment variables can be used with "run"
5595 (1) If a command line (or an environment variable executed by a "run"
5596 command) contains several commands separated by semicolon, and
5597 one of these commands fails, then the remaining commands will be
5600 (2) If you execute several variables with one call to run (i. e.
5601 calling run with a list of variables as arguments), any failing
5602 command will cause "run" to terminate, i. e. the remaining
5603 variables are not executed.
5605 Note for Redundant Ethernet Interfaces:
5606 =======================================
5608 Some boards come with redundant Ethernet interfaces; U-Boot supports
5609 such configurations and is capable of automatic selection of a
5610 "working" interface when needed. MAC assignment works as follows:
5612 Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
5613 MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
5614 "eth1addr" (=>eth1), "eth2addr", ...
5616 If the network interface stores some valid MAC address (for instance
5617 in SROM), this is used as default address if there is NO correspon-
5618 ding setting in the environment; if the corresponding environment
5619 variable is set, this overrides the settings in the card; that means:
5621 o If the SROM has a valid MAC address, and there is no address in the
5622 environment, the SROM's address is used.
5624 o If there is no valid address in the SROM, and a definition in the
5625 environment exists, then the value from the environment variable is
5628 o If both the SROM and the environment contain a MAC address, and
5629 both addresses are the same, this MAC address is used.
5631 o If both the SROM and the environment contain a MAC address, and the
5632 addresses differ, the value from the environment is used and a
5635 o If neither SROM nor the environment contain a MAC address, an error
5636 is raised. If CONFIG_NET_RANDOM_ETHADDR is defined, then in this case
5637 a random, locally-assigned MAC is used.
5639 If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses
5640 will be programmed into hardware as part of the initialization process. This
5641 may be skipped by setting the appropriate 'ethmacskip' environment variable.
5642 The naming convention is as follows:
5643 "ethmacskip" (=>eth0), "eth1macskip" (=>eth1) etc.
5648 U-Boot is capable of booting (and performing other auxiliary operations on)
5649 images in two formats:
5651 New uImage format (FIT)
5652 -----------------------
5654 Flexible and powerful format based on Flattened Image Tree -- FIT (similar
5655 to Flattened Device Tree). It allows the use of images with multiple
5656 components (several kernels, ramdisks, etc.), with contents protected by
5657 SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory.
5663 Old image format is based on binary files which can be basically anything,
5664 preceded by a special header; see the definitions in include/image.h for
5665 details; basically, the header defines the following image properties:
5667 * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
5668 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
5669 LynxOS, pSOS, QNX, RTEMS, INTEGRITY;
5670 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS,
5672 * Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86,
5673 IA64, MIPS, NDS32, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
5674 Currently supported: ARM, AVR32, Intel x86, MIPS, NDS32, Nios II, PowerPC).
5675 * Compression Type (uncompressed, gzip, bzip2)
5681 The header is marked by a special Magic Number, and both the header
5682 and the data portions of the image are secured against corruption by
5689 Although U-Boot should support any OS or standalone application
5690 easily, the main focus has always been on Linux during the design of
5693 U-Boot includes many features that so far have been part of some
5694 special "boot loader" code within the Linux kernel. Also, any
5695 "initrd" images to be used are no longer part of one big Linux image;
5696 instead, kernel and "initrd" are separate images. This implementation
5697 serves several purposes:
5699 - the same features can be used for other OS or standalone
5700 applications (for instance: using compressed images to reduce the
5701 Flash memory footprint)
5703 - it becomes much easier to port new Linux kernel versions because
5704 lots of low-level, hardware dependent stuff are done by U-Boot
5706 - the same Linux kernel image can now be used with different "initrd"
5707 images; of course this also means that different kernel images can
5708 be run with the same "initrd". This makes testing easier (you don't
5709 have to build a new "zImage.initrd" Linux image when you just
5710 change a file in your "initrd"). Also, a field-upgrade of the
5711 software is easier now.
5717 Porting Linux to U-Boot based systems:
5718 ---------------------------------------
5720 U-Boot cannot save you from doing all the necessary modifications to
5721 configure the Linux device drivers for use with your target hardware
5722 (no, we don't intend to provide a full virtual machine interface to
5725 But now you can ignore ALL boot loader code (in arch/powerpc/mbxboot).
5727 Just make sure your machine specific header file (for instance
5728 include/asm-ppc/tqm8xx.h) includes the same definition of the Board
5729 Information structure as we define in include/asm-<arch>/u-boot.h,
5730 and make sure that your definition of IMAP_ADDR uses the same value
5731 as your U-Boot configuration in CONFIG_SYS_IMMR.
5733 Note that U-Boot now has a driver model, a unified model for drivers.
5734 If you are adding a new driver, plumb it into driver model. If there
5735 is no uclass available, you are encouraged to create one. See
5739 Configuring the Linux kernel:
5740 -----------------------------
5742 No specific requirements for U-Boot. Make sure you have some root
5743 device (initial ramdisk, NFS) for your target system.
5746 Building a Linux Image:
5747 -----------------------
5749 With U-Boot, "normal" build targets like "zImage" or "bzImage" are
5750 not used. If you use recent kernel source, a new build target
5751 "uImage" will exist which automatically builds an image usable by
5752 U-Boot. Most older kernels also have support for a "pImage" target,
5753 which was introduced for our predecessor project PPCBoot and uses a
5754 100% compatible format.
5758 make TQM850L_defconfig
5763 The "uImage" build target uses a special tool (in 'tools/mkimage') to
5764 encapsulate a compressed Linux kernel image with header information,
5765 CRC32 checksum etc. for use with U-Boot. This is what we are doing:
5767 * build a standard "vmlinux" kernel image (in ELF binary format):
5769 * convert the kernel into a raw binary image:
5771 ${CROSS_COMPILE}-objcopy -O binary \
5772 -R .note -R .comment \
5773 -S vmlinux linux.bin
5775 * compress the binary image:
5779 * package compressed binary image for U-Boot:
5781 mkimage -A ppc -O linux -T kernel -C gzip \
5782 -a 0 -e 0 -n "Linux Kernel Image" \
5783 -d linux.bin.gz uImage
5786 The "mkimage" tool can also be used to create ramdisk images for use
5787 with U-Boot, either separated from the Linux kernel image, or
5788 combined into one file. "mkimage" encapsulates the images with a 64
5789 byte header containing information about target architecture,
5790 operating system, image type, compression method, entry points, time
5791 stamp, CRC32 checksums, etc.
5793 "mkimage" can be called in two ways: to verify existing images and
5794 print the header information, or to build new images.
5796 In the first form (with "-l" option) mkimage lists the information
5797 contained in the header of an existing U-Boot image; this includes
5798 checksum verification:
5800 tools/mkimage -l image
5801 -l ==> list image header information
5803 The second form (with "-d" option) is used to build a U-Boot image
5804 from a "data file" which is used as image payload:
5806 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
5807 -n name -d data_file image
5808 -A ==> set architecture to 'arch'
5809 -O ==> set operating system to 'os'
5810 -T ==> set image type to 'type'
5811 -C ==> set compression type 'comp'
5812 -a ==> set load address to 'addr' (hex)
5813 -e ==> set entry point to 'ep' (hex)
5814 -n ==> set image name to 'name'
5815 -d ==> use image data from 'datafile'
5817 Right now, all Linux kernels for PowerPC systems use the same load
5818 address (0x00000000), but the entry point address depends on the
5821 - 2.2.x kernels have the entry point at 0x0000000C,
5822 - 2.3.x and later kernels have the entry point at 0x00000000.
5824 So a typical call to build a U-Boot image would read:
5826 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
5827 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
5828 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz \
5829 > examples/uImage.TQM850L
5830 Image Name: 2.4.4 kernel for TQM850L
5831 Created: Wed Jul 19 02:34:59 2000
5832 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5833 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
5834 Load Address: 0x00000000
5835 Entry Point: 0x00000000
5837 To verify the contents of the image (or check for corruption):
5839 -> tools/mkimage -l examples/uImage.TQM850L
5840 Image Name: 2.4.4 kernel for TQM850L
5841 Created: Wed Jul 19 02:34:59 2000
5842 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5843 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
5844 Load Address: 0x00000000
5845 Entry Point: 0x00000000
5847 NOTE: for embedded systems where boot time is critical you can trade
5848 speed for memory and install an UNCOMPRESSED image instead: this
5849 needs more space in Flash, but boots much faster since it does not
5850 need to be uncompressed:
5852 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz
5853 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
5854 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
5855 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux \
5856 > examples/uImage.TQM850L-uncompressed
5857 Image Name: 2.4.4 kernel for TQM850L
5858 Created: Wed Jul 19 02:34:59 2000
5859 Image Type: PowerPC Linux Kernel Image (uncompressed)
5860 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
5861 Load Address: 0x00000000
5862 Entry Point: 0x00000000
5865 Similar you can build U-Boot images from a 'ramdisk.image.gz' file
5866 when your kernel is intended to use an initial ramdisk:
5868 -> tools/mkimage -n 'Simple Ramdisk Image' \
5869 > -A ppc -O linux -T ramdisk -C gzip \
5870 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
5871 Image Name: Simple Ramdisk Image
5872 Created: Wed Jan 12 14:01:50 2000
5873 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5874 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
5875 Load Address: 0x00000000
5876 Entry Point: 0x00000000
5878 The "dumpimage" is a tool to disassemble images built by mkimage. Its "-i"
5879 option performs the converse operation of the mkimage's second form (the "-d"
5880 option). Given an image built by mkimage, the dumpimage extracts a "data file"
5883 tools/dumpimage -i image -T type -p position data_file
5884 -i ==> extract from the 'image' a specific 'data_file'
5885 -T ==> set image type to 'type'
5886 -p ==> 'position' (starting at 0) of the 'data_file' inside the 'image'
5889 Installing a Linux Image:
5890 -------------------------
5892 To downloading a U-Boot image over the serial (console) interface,
5893 you must convert the image to S-Record format:
5895 objcopy -I binary -O srec examples/image examples/image.srec
5897 The 'objcopy' does not understand the information in the U-Boot
5898 image header, so the resulting S-Record file will be relative to
5899 address 0x00000000. To load it to a given address, you need to
5900 specify the target address as 'offset' parameter with the 'loads'
5903 Example: install the image to address 0x40100000 (which on the
5904 TQM8xxL is in the first Flash bank):
5906 => erase 40100000 401FFFFF
5912 ## Ready for S-Record download ...
5913 ~>examples/image.srec
5914 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
5916 15989 15990 15991 15992
5917 [file transfer complete]
5919 ## Start Addr = 0x00000000
5922 You can check the success of the download using the 'iminfo' command;
5923 this includes a checksum verification so you can be sure no data
5924 corruption happened:
5928 ## Checking Image at 40100000 ...
5929 Image Name: 2.2.13 for initrd on TQM850L
5930 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5931 Data Size: 335725 Bytes = 327 kB = 0 MB
5932 Load Address: 00000000
5933 Entry Point: 0000000c
5934 Verifying Checksum ... OK
5940 The "bootm" command is used to boot an application that is stored in
5941 memory (RAM or Flash). In case of a Linux kernel image, the contents
5942 of the "bootargs" environment variable is passed to the kernel as
5943 parameters. You can check and modify this variable using the
5944 "printenv" and "setenv" commands:
5947 => printenv bootargs
5948 bootargs=root=/dev/ram
5950 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5952 => printenv bootargs
5953 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5956 ## Booting Linux kernel at 40020000 ...
5957 Image Name: 2.2.13 for NFS on TQM850L
5958 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5959 Data Size: 381681 Bytes = 372 kB = 0 MB
5960 Load Address: 00000000
5961 Entry Point: 0000000c
5962 Verifying Checksum ... OK
5963 Uncompressing Kernel Image ... OK
5964 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
5965 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5966 time_init: decrementer frequency = 187500000/60
5967 Calibrating delay loop... 49.77 BogoMIPS
5968 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
5971 If you want to boot a Linux kernel with initial RAM disk, you pass
5972 the memory addresses of both the kernel and the initrd image (PPBCOOT
5973 format!) to the "bootm" command:
5975 => imi 40100000 40200000
5977 ## Checking Image at 40100000 ...
5978 Image Name: 2.2.13 for initrd on TQM850L
5979 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5980 Data Size: 335725 Bytes = 327 kB = 0 MB
5981 Load Address: 00000000
5982 Entry Point: 0000000c
5983 Verifying Checksum ... OK
5985 ## Checking Image at 40200000 ...
5986 Image Name: Simple Ramdisk Image
5987 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5988 Data Size: 566530 Bytes = 553 kB = 0 MB
5989 Load Address: 00000000
5990 Entry Point: 00000000
5991 Verifying Checksum ... OK
5993 => bootm 40100000 40200000
5994 ## Booting Linux kernel at 40100000 ...
5995 Image Name: 2.2.13 for initrd on TQM850L
5996 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5997 Data Size: 335725 Bytes = 327 kB = 0 MB
5998 Load Address: 00000000
5999 Entry Point: 0000000c
6000 Verifying Checksum ... OK
6001 Uncompressing Kernel Image ... OK
6002 ## Loading RAMDisk Image at 40200000 ...
6003 Image Name: Simple Ramdisk Image
6004 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
6005 Data Size: 566530 Bytes = 553 kB = 0 MB
6006 Load Address: 00000000
6007 Entry Point: 00000000
6008 Verifying Checksum ... OK
6009 Loading Ramdisk ... OK
6010 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
6011 Boot arguments: root=/dev/ram
6012 time_init: decrementer frequency = 187500000/60
6013 Calibrating delay loop... 49.77 BogoMIPS
6015 RAMDISK: Compressed image found at block 0
6016 VFS: Mounted root (ext2 filesystem).
6020 Boot Linux and pass a flat device tree:
6023 First, U-Boot must be compiled with the appropriate defines. See the section
6024 titled "Linux Kernel Interface" above for a more in depth explanation. The
6025 following is an example of how to start a kernel and pass an updated
6031 oft=oftrees/mpc8540ads.dtb
6032 => tftp $oftaddr $oft
6033 Speed: 1000, full duplex
6035 TFTP from server 192.168.1.1; our IP address is 192.168.1.101
6036 Filename 'oftrees/mpc8540ads.dtb'.
6037 Load address: 0x300000
6040 Bytes transferred = 4106 (100a hex)
6041 => tftp $loadaddr $bootfile
6042 Speed: 1000, full duplex
6044 TFTP from server 192.168.1.1; our IP address is 192.168.1.2
6046 Load address: 0x200000
6047 Loading:############
6049 Bytes transferred = 1029407 (fb51f hex)
6054 => bootm $loadaddr - $oftaddr
6055 ## Booting image at 00200000 ...
6056 Image Name: Linux-2.6.17-dirty
6057 Image Type: PowerPC Linux Kernel Image (gzip compressed)
6058 Data Size: 1029343 Bytes = 1005.2 kB
6059 Load Address: 00000000
6060 Entry Point: 00000000
6061 Verifying Checksum ... OK
6062 Uncompressing Kernel Image ... OK
6063 Booting using flat device tree at 0x300000
6064 Using MPC85xx ADS machine description
6065 Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb
6069 More About U-Boot Image Types:
6070 ------------------------------
6072 U-Boot supports the following image types:
6074 "Standalone Programs" are directly runnable in the environment
6075 provided by U-Boot; it is expected that (if they behave
6076 well) you can continue to work in U-Boot after return from
6077 the Standalone Program.
6078 "OS Kernel Images" are usually images of some Embedded OS which
6079 will take over control completely. Usually these programs
6080 will install their own set of exception handlers, device
6081 drivers, set up the MMU, etc. - this means, that you cannot
6082 expect to re-enter U-Boot except by resetting the CPU.
6083 "RAMDisk Images" are more or less just data blocks, and their
6084 parameters (address, size) are passed to an OS kernel that is
6086 "Multi-File Images" contain several images, typically an OS
6087 (Linux) kernel image and one or more data images like
6088 RAMDisks. This construct is useful for instance when you want
6089 to boot over the network using BOOTP etc., where the boot
6090 server provides just a single image file, but you want to get
6091 for instance an OS kernel and a RAMDisk image.
6093 "Multi-File Images" start with a list of image sizes, each
6094 image size (in bytes) specified by an "uint32_t" in network
6095 byte order. This list is terminated by an "(uint32_t)0".
6096 Immediately after the terminating 0 follow the images, one by
6097 one, all aligned on "uint32_t" boundaries (size rounded up to
6098 a multiple of 4 bytes).
6100 "Firmware Images" are binary images containing firmware (like
6101 U-Boot or FPGA images) which usually will be programmed to
6104 "Script files" are command sequences that will be executed by
6105 U-Boot's command interpreter; this feature is especially
6106 useful when you configure U-Boot to use a real shell (hush)
6107 as command interpreter.
6109 Booting the Linux zImage:
6110 -------------------------
6112 On some platforms, it's possible to boot Linux zImage. This is done
6113 using the "bootz" command. The syntax of "bootz" command is the same
6114 as the syntax of "bootm" command.
6116 Note, defining the CONFIG_SUPPORT_RAW_INITRD allows user to supply
6117 kernel with raw initrd images. The syntax is slightly different, the
6118 address of the initrd must be augmented by it's size, in the following
6119 format: "<initrd addres>:<initrd size>".
6125 One of the features of U-Boot is that you can dynamically load and
6126 run "standalone" applications, which can use some resources of
6127 U-Boot like console I/O functions or interrupt services.
6129 Two simple examples are included with the sources:
6134 'examples/hello_world.c' contains a small "Hello World" Demo
6135 application; it is automatically compiled when you build U-Boot.
6136 It's configured to run at address 0x00040004, so you can play with it
6140 ## Ready for S-Record download ...
6141 ~>examples/hello_world.srec
6142 1 2 3 4 5 6 7 8 9 10 11 ...
6143 [file transfer complete]
6145 ## Start Addr = 0x00040004
6147 => go 40004 Hello World! This is a test.
6148 ## Starting application at 0x00040004 ...
6159 Hit any key to exit ...
6161 ## Application terminated, rc = 0x0
6163 Another example, which demonstrates how to register a CPM interrupt
6164 handler with the U-Boot code, can be found in 'examples/timer.c'.
6165 Here, a CPM timer is set up to generate an interrupt every second.
6166 The interrupt service routine is trivial, just printing a '.'
6167 character, but this is just a demo program. The application can be
6168 controlled by the following keys:
6170 ? - print current values og the CPM Timer registers
6171 b - enable interrupts and start timer
6172 e - stop timer and disable interrupts
6173 q - quit application
6176 ## Ready for S-Record download ...
6177 ~>examples/timer.srec
6178 1 2 3 4 5 6 7 8 9 10 11 ...
6179 [file transfer complete]
6181 ## Start Addr = 0x00040004
6184 ## Starting application at 0x00040004 ...
6187 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
6190 [q, b, e, ?] Set interval 1000000 us
6193 [q, b, e, ?] ........
6194 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
6197 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
6200 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
6203 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
6205 [q, b, e, ?] ...Stopping timer
6207 [q, b, e, ?] ## Application terminated, rc = 0x0
6213 Over time, many people have reported problems when trying to use the
6214 "minicom" terminal emulation program for serial download. I (wd)
6215 consider minicom to be broken, and recommend not to use it. Under
6216 Unix, I recommend to use C-Kermit for general purpose use (and
6217 especially for kermit binary protocol download ("loadb" command), and
6218 use "cu" for S-Record download ("loads" command). See
6219 http://www.denx.de/wiki/view/DULG/SystemSetup#Section_4.3.
6220 for help with kermit.
6223 Nevertheless, if you absolutely want to use it try adding this
6224 configuration to your "File transfer protocols" section:
6226 Name Program Name U/D FullScr IO-Red. Multi
6227 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
6228 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
6234 Starting at version 0.9.2, U-Boot supports NetBSD both as host
6235 (build U-Boot) and target system (boots NetBSD/mpc8xx).
6237 Building requires a cross environment; it is known to work on
6238 NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
6239 need gmake since the Makefiles are not compatible with BSD make).
6240 Note that the cross-powerpc package does not install include files;
6241 attempting to build U-Boot will fail because <machine/ansi.h> is
6242 missing. This file has to be installed and patched manually:
6244 # cd /usr/pkg/cross/powerpc-netbsd/include
6246 # ln -s powerpc machine
6247 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
6248 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
6250 Native builds *don't* work due to incompatibilities between native
6251 and U-Boot include files.
6253 Booting assumes that (the first part of) the image booted is a
6254 stage-2 loader which in turn loads and then invokes the kernel
6255 proper. Loader sources will eventually appear in the NetBSD source
6256 tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
6257 meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz
6260 Implementation Internals:
6261 =========================
6263 The following is not intended to be a complete description of every
6264 implementation detail. However, it should help to understand the
6265 inner workings of U-Boot and make it easier to port it to custom
6269 Initial Stack, Global Data:
6270 ---------------------------
6272 The implementation of U-Boot is complicated by the fact that U-Boot
6273 starts running out of ROM (flash memory), usually without access to
6274 system RAM (because the memory controller is not initialized yet).
6275 This means that we don't have writable Data or BSS segments, and BSS
6276 is not initialized as zero. To be able to get a C environment working
6277 at all, we have to allocate at least a minimal stack. Implementation
6278 options for this are defined and restricted by the CPU used: Some CPU
6279 models provide on-chip memory (like the IMMR area on MPC8xx and
6280 MPC826x processors), on others (parts of) the data cache can be
6281 locked as (mis-) used as memory, etc.
6283 Chris Hallinan posted a good summary of these issues to the
6284 U-Boot mailing list:
6286 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
6287 From: "Chris Hallinan" <clh@net1plus.com>
6288 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
6291 Correct me if I'm wrong, folks, but the way I understand it
6292 is this: Using DCACHE as initial RAM for Stack, etc, does not
6293 require any physical RAM backing up the cache. The cleverness
6294 is that the cache is being used as a temporary supply of
6295 necessary storage before the SDRAM controller is setup. It's
6296 beyond the scope of this list to explain the details, but you
6297 can see how this works by studying the cache architecture and
6298 operation in the architecture and processor-specific manuals.
6300 OCM is On Chip Memory, which I believe the 405GP has 4K. It
6301 is another option for the system designer to use as an
6302 initial stack/RAM area prior to SDRAM being available. Either
6303 option should work for you. Using CS 4 should be fine if your
6304 board designers haven't used it for something that would
6305 cause you grief during the initial boot! It is frequently not
6308 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere
6309 with your processor/board/system design. The default value
6310 you will find in any recent u-boot distribution in
6311 walnut.h should work for you. I'd set it to a value larger
6312 than your SDRAM module. If you have a 64MB SDRAM module, set
6313 it above 400_0000. Just make sure your board has no resources
6314 that are supposed to respond to that address! That code in
6315 start.S has been around a while and should work as is when
6316 you get the config right.
6321 It is essential to remember this, since it has some impact on the C
6322 code for the initialization procedures:
6324 * Initialized global data (data segment) is read-only. Do not attempt
6327 * Do not use any uninitialized global data (or implicitly initialized
6328 as zero data - BSS segment) at all - this is undefined, initiali-
6329 zation is performed later (when relocating to RAM).
6331 * Stack space is very limited. Avoid big data buffers or things like
6334 Having only the stack as writable memory limits means we cannot use
6335 normal global data to share information between the code. But it
6336 turned out that the implementation of U-Boot can be greatly
6337 simplified by making a global data structure (gd_t) available to all
6338 functions. We could pass a pointer to this data as argument to _all_
6339 functions, but this would bloat the code. Instead we use a feature of
6340 the GCC compiler (Global Register Variables) to share the data: we
6341 place a pointer (gd) to the global data into a register which we
6342 reserve for this purpose.
6344 When choosing a register for such a purpose we are restricted by the
6345 relevant (E)ABI specifications for the current architecture, and by
6346 GCC's implementation.
6348 For PowerPC, the following registers have specific use:
6350 R2: reserved for system use
6351 R3-R4: parameter passing and return values
6352 R5-R10: parameter passing
6353 R13: small data area pointer
6357 (U-Boot also uses R12 as internal GOT pointer. r12
6358 is a volatile register so r12 needs to be reset when
6359 going back and forth between asm and C)
6361 ==> U-Boot will use R2 to hold a pointer to the global data
6363 Note: on PPC, we could use a static initializer (since the
6364 address of the global data structure is known at compile time),
6365 but it turned out that reserving a register results in somewhat
6366 smaller code - although the code savings are not that big (on
6367 average for all boards 752 bytes for the whole U-Boot image,
6368 624 text + 127 data).
6370 On Blackfin, the normal C ABI (except for P3) is followed as documented here:
6371 http://docs.blackfin.uclinux.org/doku.php?id=application_binary_interface
6373 ==> U-Boot will use P3 to hold a pointer to the global data
6375 On ARM, the following registers are used:
6377 R0: function argument word/integer result
6378 R1-R3: function argument word
6379 R9: platform specific
6380 R10: stack limit (used only if stack checking is enabled)
6381 R11: argument (frame) pointer
6382 R12: temporary workspace
6385 R15: program counter
6387 ==> U-Boot will use R9 to hold a pointer to the global data
6389 Note: on ARM, only R_ARM_RELATIVE relocations are supported.
6391 On Nios II, the ABI is documented here:
6392 http://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf
6394 ==> U-Boot will use gp to hold a pointer to the global data
6396 Note: on Nios II, we give "-G0" option to gcc and don't use gp
6397 to access small data sections, so gp is free.
6399 On NDS32, the following registers are used:
6401 R0-R1: argument/return
6403 R15: temporary register for assembler
6404 R16: trampoline register
6405 R28: frame pointer (FP)
6406 R29: global pointer (GP)
6407 R30: link register (LP)
6408 R31: stack pointer (SP)
6409 PC: program counter (PC)
6411 ==> U-Boot will use R10 to hold a pointer to the global data
6413 NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope,
6414 or current versions of GCC may "optimize" the code too much.
6419 U-Boot runs in system state and uses physical addresses, i.e. the
6420 MMU is not used either for address mapping nor for memory protection.
6422 The available memory is mapped to fixed addresses using the memory
6423 controller. In this process, a contiguous block is formed for each
6424 memory type (Flash, SDRAM, SRAM), even when it consists of several
6425 physical memory banks.
6427 U-Boot is installed in the first 128 kB of the first Flash bank (on
6428 TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
6429 booting and sizing and initializing DRAM, the code relocates itself
6430 to the upper end of DRAM. Immediately below the U-Boot code some
6431 memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN
6432 configuration setting]. Below that, a structure with global Board
6433 Info data is placed, followed by the stack (growing downward).
6435 Additionally, some exception handler code is copied to the low 8 kB
6436 of DRAM (0x00000000 ... 0x00001FFF).
6438 So a typical memory configuration with 16 MB of DRAM could look like
6441 0x0000 0000 Exception Vector code
6444 0x0000 2000 Free for Application Use
6450 0x00FB FF20 Monitor Stack (Growing downward)
6451 0x00FB FFAC Board Info Data and permanent copy of global data
6452 0x00FC 0000 Malloc Arena
6455 0x00FE 0000 RAM Copy of Monitor Code
6456 ... eventually: LCD or video framebuffer
6457 ... eventually: pRAM (Protected RAM - unchanged by reset)
6458 0x00FF FFFF [End of RAM]
6461 System Initialization:
6462 ----------------------
6464 In the reset configuration, U-Boot starts at the reset entry point
6465 (on most PowerPC systems at address 0x00000100). Because of the reset
6466 configuration for CS0# this is a mirror of the on board Flash memory.
6467 To be able to re-map memory U-Boot then jumps to its link address.
6468 To be able to implement the initialization code in C, a (small!)
6469 initial stack is set up in the internal Dual Ported RAM (in case CPUs
6470 which provide such a feature like MPC8xx or MPC8260), or in a locked
6471 part of the data cache. After that, U-Boot initializes the CPU core,
6472 the caches and the SIU.
6474 Next, all (potentially) available memory banks are mapped using a
6475 preliminary mapping. For example, we put them on 512 MB boundaries
6476 (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
6477 on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
6478 programmed for SDRAM access. Using the temporary configuration, a
6479 simple memory test is run that determines the size of the SDRAM
6482 When there is more than one SDRAM bank, and the banks are of
6483 different size, the largest is mapped first. For equal size, the first
6484 bank (CS2#) is mapped first. The first mapping is always for address
6485 0x00000000, with any additional banks following immediately to create
6486 contiguous memory starting from 0.
6488 Then, the monitor installs itself at the upper end of the SDRAM area
6489 and allocates memory for use by malloc() and for the global Board
6490 Info data; also, the exception vector code is copied to the low RAM
6491 pages, and the final stack is set up.
6493 Only after this relocation will you have a "normal" C environment;
6494 until that you are restricted in several ways, mostly because you are
6495 running from ROM, and because the code will have to be relocated to a
6499 U-Boot Porting Guide:
6500 ----------------------
6502 [Based on messages by Jerry Van Baren in the U-Boot-Users mailing
6506 int main(int argc, char *argv[])
6508 sighandler_t no_more_time;
6510 signal(SIGALRM, no_more_time);
6511 alarm(PROJECT_DEADLINE - toSec (3 * WEEK));
6513 if (available_money > available_manpower) {
6514 Pay consultant to port U-Boot;
6518 Download latest U-Boot source;
6520 Subscribe to u-boot mailing list;
6523 email("Hi, I am new to U-Boot, how do I get started?");
6526 Read the README file in the top level directory;
6527 Read http://www.denx.de/twiki/bin/view/DULG/Manual;
6528 Read applicable doc/*.README;
6529 Read the source, Luke;
6530 /* find . -name "*.[chS]" | xargs grep -i <keyword> */
6533 if (available_money > toLocalCurrency ($2500))
6536 Add a lot of aggravation and time;
6538 if (a similar board exists) { /* hopefully... */
6539 cp -a board/<similar> board/<myboard>
6540 cp include/configs/<similar>.h include/configs/<myboard>.h
6542 Create your own board support subdirectory;
6543 Create your own board include/configs/<myboard>.h file;
6545 Edit new board/<myboard> files
6546 Edit new include/configs/<myboard>.h
6551 Add / modify source code;
6555 email("Hi, I am having problems...");
6557 Send patch file to the U-Boot email list;
6558 if (reasonable critiques)
6559 Incorporate improvements from email list code review;
6561 Defend code as written;
6567 void no_more_time (int sig)
6576 All contributions to U-Boot should conform to the Linux kernel
6577 coding style; see the file "Documentation/CodingStyle" and the script
6578 "scripts/Lindent" in your Linux kernel source directory.
6580 Source files originating from a different project (for example the
6581 MTD subsystem) are generally exempt from these guidelines and are not
6582 reformatted to ease subsequent migration to newer versions of those
6585 Please note that U-Boot is implemented in C (and to some small parts in
6586 Assembler); no C++ is used, so please do not use C++ style comments (//)
6589 Please also stick to the following formatting rules:
6590 - remove any trailing white space
6591 - use TAB characters for indentation and vertical alignment, not spaces
6592 - make sure NOT to use DOS '\r\n' line feeds
6593 - do not add more than 2 consecutive empty lines to source files
6594 - do not add trailing empty lines to source files
6596 Submissions which do not conform to the standards may be returned
6597 with a request to reformat the changes.
6603 Since the number of patches for U-Boot is growing, we need to
6604 establish some rules. Submissions which do not conform to these rules
6605 may be rejected, even when they contain important and valuable stuff.
6607 Please see http://www.denx.de/wiki/U-Boot/Patches for details.
6609 Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>;
6610 see http://lists.denx.de/mailman/listinfo/u-boot
6612 When you send a patch, please include the following information with
6615 * For bug fixes: a description of the bug and how your patch fixes
6616 this bug. Please try to include a way of demonstrating that the
6617 patch actually fixes something.
6619 * For new features: a description of the feature and your
6622 * A CHANGELOG entry as plaintext (separate from the patch)
6624 * For major contributions, your entry to the CREDITS file
6626 * When you add support for a new board, don't forget to add a
6627 maintainer e-mail address to the boards.cfg file, too.
6629 * If your patch adds new configuration options, don't forget to
6630 document these in the README file.
6632 * The patch itself. If you are using git (which is *strongly*
6633 recommended) you can easily generate the patch using the
6634 "git format-patch". If you then use "git send-email" to send it to
6635 the U-Boot mailing list, you will avoid most of the common problems
6636 with some other mail clients.
6638 If you cannot use git, use "diff -purN OLD NEW". If your version of
6639 diff does not support these options, then get the latest version of
6642 The current directory when running this command shall be the parent
6643 directory of the U-Boot source tree (i. e. please make sure that
6644 your patch includes sufficient directory information for the
6647 We prefer patches as plain text. MIME attachments are discouraged,
6648 and compressed attachments must not be used.
6650 * If one logical set of modifications affects or creates several
6651 files, all these changes shall be submitted in a SINGLE patch file.
6653 * Changesets that contain different, unrelated modifications shall be
6654 submitted as SEPARATE patches, one patch per changeset.
6659 * Before sending the patch, run the MAKEALL script on your patched
6660 source tree and make sure that no errors or warnings are reported
6661 for any of the boards.
6663 * Keep your modifications to the necessary minimum: A patch
6664 containing several unrelated changes or arbitrary reformats will be
6665 returned with a request to re-formatting / split it.
6667 * If you modify existing code, make sure that your new code does not
6668 add to the memory footprint of the code ;-) Small is beautiful!
6669 When adding new features, these should compile conditionally only
6670 (using #ifdef), and the resulting code with the new feature
6671 disabled must not need more memory than the old code without your
6674 * Remember that there is a size limit of 100 kB per message on the
6675 u-boot mailing list. Bigger patches will be moderated. If they are
6676 reasonable and not too big, they will be acknowledged. But patches
6677 bigger than the size limit should be avoided.
projects / u-boot / blob