2 # (C) Copyright 2000 - 2013
3 # Wolfgang Denk, DENX Software Engineering, wd@denx.de.
5 # SPDX-License-Identifier: GPL-2.0+
11 This directory contains the source code for U-Boot, a boot loader for
12 Embedded boards based on PowerPC, ARM, MIPS and several other
13 processors, which can be installed in a boot ROM and used to
14 initialize and test the hardware or to download and run application
17 The development of U-Boot is closely related to Linux: some parts of
18 the source code originate in the Linux source tree, we have some
19 header files in common, and special provision has been made to
20 support booting of Linux images.
22 Some attention has been paid to make this software easily
23 configurable and extendable. For instance, all monitor commands are
24 implemented with the same call interface, so that it's very easy to
25 add new commands. Also, instead of permanently adding rarely used
26 code (for instance hardware test utilities) to the monitor, you can
27 load and run it dynamically.
33 In general, all boards for which a configuration option exists in the
34 Makefile have been tested to some extent and can be considered
35 "working". In fact, many of them are used in production systems.
37 In case of problems see the CHANGELOG and CREDITS files to find out
38 who contributed the specific port. The boards.cfg file lists board
41 Note: There is no CHANGELOG file in the actual U-Boot source tree;
42 it can be created dynamically from the Git log using:
50 In case you have questions about, problems with or contributions for
51 U-Boot you should send a message to the U-Boot mailing list at
52 <u-boot@lists.denx.de>. There is also an archive of previous traffic
53 on the mailing list - please search the archive before asking FAQ's.
54 Please see http://lists.denx.de/pipermail/u-boot and
55 http://dir.gmane.org/gmane.comp.boot-loaders.u-boot
58 Where to get source code:
59 =========================
61 The U-Boot source code is maintained in the git repository at
62 git://www.denx.de/git/u-boot.git ; you can browse it online at
63 http://www.denx.de/cgi-bin/gitweb.cgi?p=u-boot.git;a=summary
65 The "snapshot" links on this page allow you to download tarballs of
66 any version you might be interested in. Official releases are also
67 available for FTP download from the ftp://ftp.denx.de/pub/u-boot/
70 Pre-built (and tested) images are available from
71 ftp://ftp.denx.de/pub/u-boot/images/
77 - start from 8xxrom sources
78 - create PPCBoot project (http://sourceforge.net/projects/ppcboot)
80 - make it easier to add custom boards
81 - make it possible to add other [PowerPC] CPUs
82 - extend functions, especially:
83 * Provide extended interface to Linux boot loader
86 * PCMCIA / CompactFlash / ATA disk / SCSI ... boot
87 - create ARMBoot project (http://sourceforge.net/projects/armboot)
88 - add other CPU families (starting with ARM)
89 - create U-Boot project (http://sourceforge.net/projects/u-boot)
90 - current project page: see http://www.denx.de/wiki/U-Boot
96 The "official" name of this project is "Das U-Boot". The spelling
97 "U-Boot" shall be used in all written text (documentation, comments
98 in source files etc.). Example:
100 This is the README file for the U-Boot project.
102 File names etc. shall be based on the string "u-boot". Examples:
104 include/asm-ppc/u-boot.h
106 #include <asm/u-boot.h>
108 Variable names, preprocessor constants etc. shall be either based on
109 the string "u_boot" or on "U_BOOT". Example:
111 U_BOOT_VERSION u_boot_logo
112 IH_OS_U_BOOT u_boot_hush_start
118 Starting with the release in October 2008, the names of the releases
119 were changed from numerical release numbers without deeper meaning
120 into a time stamp based numbering. Regular releases are identified by
121 names consisting of the calendar year and month of the release date.
122 Additional fields (if present) indicate release candidates or bug fix
123 releases in "stable" maintenance trees.
126 U-Boot v2009.11 - Release November 2009
127 U-Boot v2009.11.1 - Release 1 in version November 2009 stable tree
128 U-Boot v2010.09-rc1 - Release candiate 1 for September 2010 release
134 /arch Architecture specific files
135 /arc Files generic to ARC architecture
136 /cpu CPU specific files
137 /arc700 Files specific to ARC 700 CPUs
138 /lib Architecture specific library files
139 /arm Files generic to ARM architecture
140 /cpu CPU specific files
141 /arm720t Files specific to ARM 720 CPUs
142 /arm920t Files specific to ARM 920 CPUs
143 /at91 Files specific to Atmel AT91RM9200 CPU
144 /imx Files specific to Freescale MC9328 i.MX CPUs
145 /s3c24x0 Files specific to Samsung S3C24X0 CPUs
146 /arm926ejs Files specific to ARM 926 CPUs
147 /arm1136 Files specific to ARM 1136 CPUs
148 /pxa Files specific to Intel XScale PXA CPUs
149 /sa1100 Files specific to Intel StrongARM SA1100 CPUs
150 /lib Architecture specific library files
151 /avr32 Files generic to AVR32 architecture
152 /cpu CPU specific files
153 /lib Architecture specific library files
154 /blackfin Files generic to Analog Devices Blackfin architecture
155 /cpu CPU specific files
156 /lib Architecture specific library files
157 /m68k Files generic to m68k architecture
158 /cpu CPU specific files
159 /mcf52x2 Files specific to Freescale ColdFire MCF52x2 CPUs
160 /mcf5227x Files specific to Freescale ColdFire MCF5227x CPUs
161 /mcf532x Files specific to Freescale ColdFire MCF5329 CPUs
162 /mcf5445x Files specific to Freescale ColdFire MCF5445x CPUs
163 /mcf547x_8x Files specific to Freescale ColdFire MCF547x_8x CPUs
164 /lib Architecture specific library files
165 /microblaze Files generic to microblaze architecture
166 /cpu CPU specific files
167 /lib Architecture specific library files
168 /mips Files generic to MIPS architecture
169 /cpu CPU specific files
170 /mips32 Files specific to MIPS32 CPUs
171 /mips64 Files specific to MIPS64 CPUs
172 /lib Architecture specific library files
173 /nds32 Files generic to NDS32 architecture
174 /cpu CPU specific files
175 /n1213 Files specific to Andes Technology N1213 CPUs
176 /lib Architecture specific library files
177 /nios2 Files generic to Altera NIOS2 architecture
178 /cpu CPU specific files
179 /lib Architecture specific library files
180 /openrisc Files generic to OpenRISC architecture
181 /cpu CPU specific files
182 /lib Architecture specific library files
183 /powerpc Files generic to PowerPC architecture
184 /cpu CPU specific files
185 /mpc5xx Files specific to Freescale MPC5xx CPUs
186 /mpc5xxx Files specific to Freescale MPC5xxx CPUs
187 /mpc8xx Files specific to Freescale MPC8xx CPUs
188 /mpc8260 Files specific to Freescale MPC8260 CPUs
189 /mpc85xx Files specific to Freescale MPC85xx CPUs
190 /ppc4xx Files specific to AMCC PowerPC 4xx CPUs
191 /lib Architecture specific library files
192 /sh Files generic to SH architecture
193 /cpu CPU specific files
194 /sh2 Files specific to sh2 CPUs
195 /sh3 Files specific to sh3 CPUs
196 /sh4 Files specific to sh4 CPUs
197 /lib Architecture specific library files
198 /sparc Files generic to SPARC architecture
199 /cpu CPU specific files
200 /leon2 Files specific to Gaisler LEON2 SPARC CPU
201 /leon3 Files specific to Gaisler LEON3 SPARC CPU
202 /lib Architecture specific library files
203 /x86 Files generic to x86 architecture
204 /cpu CPU specific files
205 /lib Architecture specific library files
206 /api Machine/arch independent API for external apps
207 /board Board dependent files
208 /common Misc architecture independent functions
209 /disk Code for disk drive partition handling
210 /doc Documentation (don't expect too much)
211 /drivers Commonly used device drivers
212 /dts Contains Makefile for building internal U-Boot fdt.
213 /examples Example code for standalone applications, etc.
214 /fs Filesystem code (cramfs, ext2, jffs2, etc.)
215 /include Header Files
216 /lib Files generic to all architectures
217 /libfdt Library files to support flattened device trees
218 /lzma Library files to support LZMA decompression
219 /lzo Library files to support LZO decompression
221 /post Power On Self Test
222 /spl Secondary Program Loader framework
223 /tools Tools to build S-Record or U-Boot images, etc.
225 Software Configuration:
226 =======================
228 Configuration is usually done using C preprocessor defines; the
229 rationale behind that is to avoid dead code whenever possible.
231 There are two classes of configuration variables:
233 * Configuration _OPTIONS_:
234 These are selectable by the user and have names beginning with
237 * Configuration _SETTINGS_:
238 These depend on the hardware etc. and should not be meddled with if
239 you don't know what you're doing; they have names beginning with
242 Later we will add a configuration tool - probably similar to or even
243 identical to what's used for the Linux kernel. Right now, we have to
244 do the configuration by hand, which means creating some symbolic
245 links and editing some configuration files. We use the TQM8xxL boards
249 Selection of Processor Architecture and Board Type:
250 ---------------------------------------------------
252 For all supported boards there are ready-to-use default
253 configurations available; just type "make <board_name>_defconfig".
255 Example: For a TQM823L module type:
258 make TQM823L_defconfig
260 For the Cogent platform, you need to specify the CPU type as well;
261 e.g. "make cogent_mpc8xx_defconfig". And also configure the cogent
262 directory according to the instructions in cogent/README.
268 U-Boot can be built natively to run on a Linux host using the 'sandbox'
269 board. This allows feature development which is not board- or architecture-
270 specific to be undertaken on a native platform. The sandbox is also used to
271 run some of U-Boot's tests.
273 See board/sandbox/README.sandbox for more details.
276 Board Initialisation Flow:
277 --------------------------
279 This is the intended start-up flow for boards. This should apply for both
280 SPL and U-Boot proper (i.e. they both follow the same rules). At present SPL
281 mostly uses a separate code path, but the funtion names and roles of each
282 function are the same. Some boards or architectures may not conform to this.
283 At least most ARM boards which use CONFIG_SPL_FRAMEWORK conform to this.
285 Execution starts with start.S with three functions called during init after
286 that. The purpose and limitations of each is described below.
289 - purpose: essential init to permit execution to reach board_init_f()
290 - no global_data or BSS
291 - there is no stack (ARMv7 may have one but it will soon be removed)
292 - must not set up SDRAM or use console
293 - must only do the bare minimum to allow execution to continue to
295 - this is almost never needed
296 - return normally from this function
299 - purpose: set up the machine ready for running board_init_r():
300 i.e. SDRAM and serial UART
301 - global_data is available
303 - BSS is not available, so you cannot use global/static variables,
304 only stack variables and global_data
306 Non-SPL-specific notes:
307 - dram_init() is called to set up DRAM. If already done in SPL this
311 - you can override the entire board_init_f() function with your own
313 - preloader_console_init() can be called here in extremis
314 - should set up SDRAM, and anything needed to make the UART work
315 - these is no need to clear BSS, it will be done by crt0.S
316 - must return normally from this function (don't call board_init_r()
319 Here the BSS is cleared. For SPL, if CONFIG_SPL_STACK_R is defined, then at
320 this point the stack and global_data are relocated to below
321 CONFIG_SPL_STACK_R_ADDR. For non-SPL, U-Boot is relocated to run at the top of
325 - purpose: main execution, common code
326 - global_data is available
328 - BSS is available, all static/global variables can be used
329 - execution eventually continues to main_loop()
331 Non-SPL-specific notes:
332 - U-Boot is relocated to the top of memory and is now running from
336 - stack is optionally in SDRAM, if CONFIG_SPL_STACK_R is defined and
337 CONFIG_SPL_STACK_R_ADDR points into SDRAM
338 - preloader_console_init() can be called here - typically this is
339 done by defining CONFIG_SPL_BOARD_INIT and then supplying a
340 spl_board_init() function containing this call
341 - loads U-Boot or (in falcon mode) Linux
345 Configuration Options:
346 ----------------------
348 Configuration depends on the combination of board and CPU type; all
349 such information is kept in a configuration file
350 "include/configs/<board_name>.h".
352 Example: For a TQM823L module, all configuration settings are in
353 "include/configs/TQM823L.h".
356 Many of the options are named exactly as the corresponding Linux
357 kernel configuration options. The intention is to make it easier to
358 build a config tool - later.
361 The following options need to be configured:
363 - CPU Type: Define exactly one, e.g. CONFIG_MPC85XX.
365 - Board Type: Define exactly one, e.g. CONFIG_MPC8540ADS.
367 - CPU Daughterboard Type: (if CONFIG_ATSTK1000 is defined)
368 Define exactly one, e.g. CONFIG_ATSTK1002
370 - CPU Module Type: (if CONFIG_COGENT is defined)
371 Define exactly one of
373 --- FIXME --- not tested yet:
374 CONFIG_CMA286_60, CONFIG_CMA286_21, CONFIG_CMA286_60P,
375 CONFIG_CMA287_23, CONFIG_CMA287_50
377 - Motherboard Type: (if CONFIG_COGENT is defined)
378 Define exactly one of
379 CONFIG_CMA101, CONFIG_CMA102
381 - Motherboard I/O Modules: (if CONFIG_COGENT is defined)
382 Define one or more of
385 - Motherboard Options: (if CONFIG_CMA101 or CONFIG_CMA102 are defined)
386 Define one or more of
387 CONFIG_LCD_HEARTBEAT - update a character position on
388 the LCD display every second with
391 - Marvell Family Member
392 CONFIG_SYS_MVFS - define it if you want to enable
393 multiple fs option at one time
394 for marvell soc family
396 - 8xx CPU Options: (if using an MPC8xx CPU)
397 CONFIG_8xx_GCLK_FREQ - deprecated: CPU clock if
398 get_gclk_freq() cannot work
399 e.g. if there is no 32KHz
400 reference PIT/RTC clock
401 CONFIG_8xx_OSCLK - PLL input clock (either EXTCLK
404 - 859/866/885 CPU options: (if using a MPC859 or MPC866 or MPC885 CPU):
405 CONFIG_SYS_8xx_CPUCLK_MIN
406 CONFIG_SYS_8xx_CPUCLK_MAX
407 CONFIG_8xx_CPUCLK_DEFAULT
408 See doc/README.MPC866
410 CONFIG_SYS_MEASURE_CPUCLK
412 Define this to measure the actual CPU clock instead
413 of relying on the correctness of the configured
414 values. Mostly useful for board bringup to make sure
415 the PLL is locked at the intended frequency. Note
416 that this requires a (stable) reference clock (32 kHz
417 RTC clock or CONFIG_SYS_8XX_XIN)
419 CONFIG_SYS_DELAYED_ICACHE
421 Define this option if you want to enable the
422 ICache only when Code runs from RAM.
427 Specifies that the core is a 64-bit PowerPC implementation (implements
428 the "64" category of the Power ISA). This is necessary for ePAPR
429 compliance, among other possible reasons.
431 CONFIG_SYS_FSL_TBCLK_DIV
433 Defines the core time base clock divider ratio compared to the
434 system clock. On most PQ3 devices this is 8, on newer QorIQ
435 devices it can be 16 or 32. The ratio varies from SoC to Soc.
437 CONFIG_SYS_FSL_PCIE_COMPAT
439 Defines the string to utilize when trying to match PCIe device
440 tree nodes for the given platform.
442 CONFIG_SYS_PPC_E500_DEBUG_TLB
444 Enables a temporary TLB entry to be used during boot to work
445 around limitations in e500v1 and e500v2 external debugger
446 support. This reduces the portions of the boot code where
447 breakpoints and single stepping do not work. The value of this
448 symbol should be set to the TLB1 entry to be used for this
451 CONFIG_SYS_FSL_ERRATUM_A004510
453 Enables a workaround for erratum A004510. If set,
454 then CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV and
455 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY must be set.
457 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV
458 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV2 (optional)
460 Defines one or two SoC revisions (low 8 bits of SVR)
461 for which the A004510 workaround should be applied.
463 The rest of SVR is either not relevant to the decision
464 of whether the erratum is present (e.g. p2040 versus
465 p2041) or is implied by the build target, which controls
466 whether CONFIG_SYS_FSL_ERRATUM_A004510 is set.
468 See Freescale App Note 4493 for more information about
471 CONFIG_A003399_NOR_WORKAROUND
472 Enables a workaround for IFC erratum A003399. It is only
473 required during NOR boot.
475 CONFIG_A008044_WORKAROUND
476 Enables a workaround for T1040/T1042 erratum A008044. It is only
477 required during NAND boot and valid for Rev 1.0 SoC revision
479 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY
481 This is the value to write into CCSR offset 0x18600
482 according to the A004510 workaround.
484 CONFIG_SYS_FSL_DSP_DDR_ADDR
485 This value denotes start offset of DDR memory which is
486 connected exclusively to the DSP cores.
488 CONFIG_SYS_FSL_DSP_M2_RAM_ADDR
489 This value denotes start offset of M2 memory
490 which is directly connected to the DSP core.
492 CONFIG_SYS_FSL_DSP_M3_RAM_ADDR
493 This value denotes start offset of M3 memory which is directly
494 connected to the DSP core.
496 CONFIG_SYS_FSL_DSP_CCSRBAR_DEFAULT
497 This value denotes start offset of DSP CCSR space.
499 CONFIG_SYS_FSL_SINGLE_SOURCE_CLK
500 Single Source Clock is clocking mode present in some of FSL SoC's.
501 In this mode, a single differential clock is used to supply
502 clocks to the sysclock, ddrclock and usbclock.
504 CONFIG_SYS_CPC_REINIT_F
505 This CONFIG is defined when the CPC is configured as SRAM at the
506 time of U-boot entry and is required to be re-initialized.
509 Indicates this SoC supports deep sleep feature. If deep sleep is
510 supported, core will start to execute uboot when wakes up.
512 - Generic CPU options:
513 CONFIG_SYS_GENERIC_GLOBAL_DATA
514 Defines global data is initialized in generic board board_init_f().
515 If this macro is defined, global data is created and cleared in
516 generic board board_init_f(). Without this macro, architecture/board
517 should initialize global data before calling board_init_f().
519 CONFIG_SYS_BIG_ENDIAN, CONFIG_SYS_LITTLE_ENDIAN
521 Defines the endianess of the CPU. Implementation of those
522 values is arch specific.
525 Freescale DDR driver in use. This type of DDR controller is
526 found in mpc83xx, mpc85xx, mpc86xx as well as some ARM core
529 CONFIG_SYS_FSL_DDR_ADDR
530 Freescale DDR memory-mapped register base.
532 CONFIG_SYS_FSL_DDR_EMU
533 Specify emulator support for DDR. Some DDR features such as
534 deskew training are not available.
536 CONFIG_SYS_FSL_DDRC_GEN1
537 Freescale DDR1 controller.
539 CONFIG_SYS_FSL_DDRC_GEN2
540 Freescale DDR2 controller.
542 CONFIG_SYS_FSL_DDRC_GEN3
543 Freescale DDR3 controller.
545 CONFIG_SYS_FSL_DDRC_GEN4
546 Freescale DDR4 controller.
548 CONFIG_SYS_FSL_DDRC_ARM_GEN3
549 Freescale DDR3 controller for ARM-based SoCs.
552 Board config to use DDR1. It can be enabled for SoCs with
553 Freescale DDR1 or DDR2 controllers, depending on the board
557 Board config to use DDR2. It can be eanbeld for SoCs with
558 Freescale DDR2 or DDR3 controllers, depending on the board
562 Board config to use DDR3. It can be enabled for SoCs with
563 Freescale DDR3 or DDR3L controllers.
566 Board config to use DDR3L. It can be enabled for SoCs with
570 Board config to use DDR4. It can be enabled for SoCs with
573 CONFIG_SYS_FSL_IFC_BE
574 Defines the IFC controller register space as Big Endian
576 CONFIG_SYS_FSL_IFC_LE
577 Defines the IFC controller register space as Little Endian
579 CONFIG_SYS_FSL_PBL_PBI
580 It enables addition of RCW (Power on reset configuration) in built image.
581 Please refer doc/README.pblimage for more details
583 CONFIG_SYS_FSL_PBL_RCW
584 It adds PBI(pre-boot instructions) commands in u-boot build image.
585 PBI commands can be used to configure SoC before it starts the execution.
586 Please refer doc/README.pblimage for more details
589 It adds a target to create boot binary having SPL binary in PBI format
590 concatenated with u-boot binary.
592 CONFIG_SYS_FSL_DDR_BE
593 Defines the DDR controller register space as Big Endian
595 CONFIG_SYS_FSL_DDR_LE
596 Defines the DDR controller register space as Little Endian
598 CONFIG_SYS_FSL_DDR_SDRAM_BASE_PHY
599 Physical address from the view of DDR controllers. It is the
600 same as CONFIG_SYS_DDR_SDRAM_BASE for all Power SoCs. But
601 it could be different for ARM SoCs.
603 CONFIG_SYS_FSL_DDR_INTLV_256B
604 DDR controller interleaving on 256-byte. This is a special
605 interleaving mode, handled by Dickens for Freescale layerscape
608 CONFIG_SYS_FSL_DDR_MAIN_NUM_CTRLS
609 Number of controllers used as main memory.
611 CONFIG_SYS_FSL_OTHER_DDR_NUM_CTRLS
612 Number of controllers used for other than main memory.
614 CONFIG_SYS_FSL_SEC_BE
615 Defines the SEC controller register space as Big Endian
617 CONFIG_SYS_FSL_SEC_LE
618 Defines the SEC controller register space as Little Endian
620 - Intel Monahans options:
621 CONFIG_SYS_MONAHANS_RUN_MODE_OSC_RATIO
623 Defines the Monahans run mode to oscillator
624 ratio. Valid values are 8, 16, 24, 31. The core
625 frequency is this value multiplied by 13 MHz.
627 CONFIG_SYS_MONAHANS_TURBO_RUN_MODE_RATIO
629 Defines the Monahans turbo mode to oscillator
630 ratio. Valid values are 1 (default if undefined) and
631 2. The core frequency as calculated above is multiplied
635 CONFIG_SYS_INIT_SP_OFFSET
637 Offset relative to CONFIG_SYS_SDRAM_BASE for initial stack
638 pointer. This is needed for the temporary stack before
641 CONFIG_SYS_MIPS_CACHE_MODE
643 Cache operation mode for the MIPS CPU.
644 See also arch/mips/include/asm/mipsregs.h.
646 CONF_CM_CACHABLE_NO_WA
649 CONF_CM_CACHABLE_NONCOHERENT
653 CONF_CM_CACHABLE_ACCELERATED
655 CONFIG_SYS_XWAY_EBU_BOOTCFG
657 Special option for Lantiq XWAY SoCs for booting from NOR flash.
658 See also arch/mips/cpu/mips32/start.S.
660 CONFIG_XWAY_SWAP_BYTES
662 Enable compilation of tools/xway-swap-bytes needed for Lantiq
663 XWAY SoCs for booting from NOR flash. The U-Boot image needs to
664 be swapped if a flash programmer is used.
667 CONFIG_SYS_EXCEPTION_VECTORS_HIGH
669 Select high exception vectors of the ARM core, e.g., do not
670 clear the V bit of the c1 register of CP15.
672 CONFIG_SYS_THUMB_BUILD
674 Use this flag to build U-Boot using the Thumb instruction
675 set for ARM architectures. Thumb instruction set provides
676 better code density. For ARM architectures that support
677 Thumb2 this flag will result in Thumb2 code generated by
680 CONFIG_ARM_ERRATA_716044
681 CONFIG_ARM_ERRATA_742230
682 CONFIG_ARM_ERRATA_743622
683 CONFIG_ARM_ERRATA_751472
684 CONFIG_ARM_ERRATA_794072
685 CONFIG_ARM_ERRATA_761320
687 If set, the workarounds for these ARM errata are applied early
688 during U-Boot startup. Note that these options force the
689 workarounds to be applied; no CPU-type/version detection
690 exists, unlike the similar options in the Linux kernel. Do not
691 set these options unless they apply!
694 Generic timer clock source frequency.
696 COUNTER_FREQUENCY_REAL
697 Generic timer clock source frequency if the real clock is
698 different from COUNTER_FREQUENCY, and can only be determined
701 NOTE: The following can be machine specific errata. These
702 do have ability to provide rudimentary version and machine
703 specific checks, but expect no product checks.
704 CONFIG_ARM_ERRATA_430973
705 CONFIG_ARM_ERRATA_454179
706 CONFIG_ARM_ERRATA_621766
707 CONFIG_ARM_ERRATA_798870
710 CONFIG_TEGRA_SUPPORT_NON_SECURE
712 Support executing U-Boot in non-secure (NS) mode. Certain
713 impossible actions will be skipped if the CPU is in NS mode,
714 such as ARM architectural timer initialization.
716 - Linux Kernel Interface:
719 U-Boot stores all clock information in Hz
720 internally. For binary compatibility with older Linux
721 kernels (which expect the clocks passed in the
722 bd_info data to be in MHz) the environment variable
723 "clocks_in_mhz" can be defined so that U-Boot
724 converts clock data to MHZ before passing it to the
726 When CONFIG_CLOCKS_IN_MHZ is defined, a definition of
727 "clocks_in_mhz=1" is automatically included in the
730 CONFIG_MEMSIZE_IN_BYTES [relevant for MIPS only]
732 When transferring memsize parameter to Linux, some versions
733 expect it to be in bytes, others in MB.
734 Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes.
738 New kernel versions are expecting firmware settings to be
739 passed using flattened device trees (based on open firmware
743 * New libfdt-based support
744 * Adds the "fdt" command
745 * The bootm command automatically updates the fdt
747 OF_CPU - The proper name of the cpus node (only required for
748 MPC512X and MPC5xxx based boards).
749 OF_SOC - The proper name of the soc node (only required for
750 MPC512X and MPC5xxx based boards).
751 OF_TBCLK - The timebase frequency.
752 OF_STDOUT_PATH - The path to the console device
754 boards with QUICC Engines require OF_QE to set UCC MAC
757 CONFIG_OF_BOARD_SETUP
759 Board code has addition modification that it wants to make
760 to the flat device tree before handing it off to the kernel
762 CONFIG_OF_SYSTEM_SETUP
764 Other code has addition modification that it wants to make
765 to the flat device tree before handing it off to the kernel.
766 This causes ft_system_setup() to be called before booting
771 This define fills in the correct boot CPU in the boot
772 param header, the default value is zero if undefined.
776 U-Boot can detect if an IDE device is present or not.
777 If not, and this new config option is activated, U-Boot
778 removes the ATA node from the DTS before booting Linux,
779 so the Linux IDE driver does not probe the device and
780 crash. This is needed for buggy hardware (uc101) where
781 no pull down resistor is connected to the signal IDE5V_DD7.
783 CONFIG_MACH_TYPE [relevant for ARM only][mandatory]
785 This setting is mandatory for all boards that have only one
786 machine type and must be used to specify the machine type
787 number as it appears in the ARM machine registry
788 (see http://www.arm.linux.org.uk/developer/machines/).
789 Only boards that have multiple machine types supported
790 in a single configuration file and the machine type is
791 runtime discoverable, do not have to use this setting.
793 - vxWorks boot parameters:
795 bootvx constructs a valid bootline using the following
796 environments variables: bootfile, ipaddr, serverip, hostname.
797 It loads the vxWorks image pointed bootfile.
799 CONFIG_SYS_VXWORKS_BOOT_DEVICE - The vxworks device name
800 CONFIG_SYS_VXWORKS_MAC_PTR - Ethernet 6 byte MA -address
801 CONFIG_SYS_VXWORKS_SERVERNAME - Name of the server
802 CONFIG_SYS_VXWORKS_BOOT_ADDR - Address of boot parameters
804 CONFIG_SYS_VXWORKS_ADD_PARAMS
806 Add it at the end of the bootline. E.g "u=username pw=secret"
808 Note: If a "bootargs" environment is defined, it will overwride
809 the defaults discussed just above.
811 - Cache Configuration:
812 CONFIG_SYS_ICACHE_OFF - Do not enable instruction cache in U-Boot
813 CONFIG_SYS_DCACHE_OFF - Do not enable data cache in U-Boot
814 CONFIG_SYS_L2CACHE_OFF- Do not enable L2 cache in U-Boot
816 - Cache Configuration for ARM:
817 CONFIG_SYS_L2_PL310 - Enable support for ARM PL310 L2 cache
819 CONFIG_SYS_PL310_BASE - Physical base address of PL310
820 controller register space
825 Define this if you want support for Amba PrimeCell PL010 UARTs.
829 Define this if you want support for Amba PrimeCell PL011 UARTs.
833 If you have Amba PrimeCell PL011 UARTs, set this variable to
834 the clock speed of the UARTs.
838 If you have Amba PrimeCell PL010 or PL011 UARTs on your board,
839 define this to a list of base addresses for each (supported)
840 port. See e.g. include/configs/versatile.h
842 CONFIG_PL011_SERIAL_RLCR
844 Some vendor versions of PL011 serial ports (e.g. ST-Ericsson U8500)
845 have separate receive and transmit line control registers. Set
846 this variable to initialize the extra register.
848 CONFIG_PL011_SERIAL_FLUSH_ON_INIT
850 On some platforms (e.g. U8500) U-Boot is loaded by a second stage
851 boot loader that has already initialized the UART. Define this
852 variable to flush the UART at init time.
854 CONFIG_SERIAL_HW_FLOW_CONTROL
856 Define this variable to enable hw flow control in serial driver.
857 Current user of this option is drivers/serial/nsl16550.c driver
860 Depending on board, define exactly one serial port
861 (like CONFIG_8xx_CONS_SMC1, CONFIG_8xx_CONS_SMC2,
862 CONFIG_8xx_CONS_SCC1, ...), or switch off the serial
863 console by defining CONFIG_8xx_CONS_NONE
865 Note: if CONFIG_8xx_CONS_NONE is defined, the serial
866 port routines must be defined elsewhere
867 (i.e. serial_init(), serial_getc(), ...)
870 Enables console device for a color framebuffer. Needs following
871 defines (cf. smiLynxEM, i8042)
872 VIDEO_FB_LITTLE_ENDIAN graphic memory organisation
874 VIDEO_HW_RECTFILL graphic chip supports
877 VIDEO_HW_BITBLT graphic chip supports
878 bit-blit (cf. smiLynxEM)
879 VIDEO_VISIBLE_COLS visible pixel columns
881 VIDEO_VISIBLE_ROWS visible pixel rows
882 VIDEO_PIXEL_SIZE bytes per pixel
883 VIDEO_DATA_FORMAT graphic data format
884 (0-5, cf. cfb_console.c)
885 VIDEO_FB_ADRS framebuffer address
886 VIDEO_KBD_INIT_FCT keyboard int fct
887 (i.e. i8042_kbd_init())
888 VIDEO_TSTC_FCT test char fct
890 VIDEO_GETC_FCT get char fct
892 CONFIG_CONSOLE_CURSOR cursor drawing on/off
893 (requires blink timer
895 CONFIG_SYS_CONSOLE_BLINK_COUNT blink interval (cf. i8042.c)
896 CONFIG_CONSOLE_TIME display time/date info in
898 (requires CONFIG_CMD_DATE)
899 CONFIG_VIDEO_LOGO display Linux logo in
901 CONFIG_VIDEO_BMP_LOGO use bmp_logo.h instead of
902 linux_logo.h for logo.
903 Requires CONFIG_VIDEO_LOGO
904 CONFIG_CONSOLE_EXTRA_INFO
905 additional board info beside
908 When CONFIG_CFB_CONSOLE_ANSI is defined, console will support
909 a limited number of ANSI escape sequences (cursor control,
910 erase functions and limited graphics rendition control).
912 When CONFIG_CFB_CONSOLE is defined, video console is
913 default i/o. Serial console can be forced with
914 environment 'console=serial'.
916 When CONFIG_SILENT_CONSOLE is defined, all console
917 messages (by U-Boot and Linux!) can be silenced with
918 the "silent" environment variable. See
919 doc/README.silent for more information.
921 CONFIG_SYS_CONSOLE_BG_COL: define the backgroundcolor, default
923 CONFIG_SYS_CONSOLE_FG_COL: define the foregroundcolor, default
927 CONFIG_BAUDRATE - in bps
928 Select one of the baudrates listed in
929 CONFIG_SYS_BAUDRATE_TABLE, see below.
930 CONFIG_SYS_BRGCLK_PRESCALE, baudrate prescale
932 - Console Rx buffer length
933 With CONFIG_SYS_SMC_RXBUFLEN it is possible to define
934 the maximum receive buffer length for the SMC.
935 This option is actual only for 82xx and 8xx possible.
936 If using CONFIG_SYS_SMC_RXBUFLEN also CONFIG_SYS_MAXIDLE
937 must be defined, to setup the maximum idle timeout for
940 - Pre-Console Buffer:
941 Prior to the console being initialised (i.e. serial UART
942 initialised etc) all console output is silently discarded.
943 Defining CONFIG_PRE_CONSOLE_BUFFER will cause U-Boot to
944 buffer any console messages prior to the console being
945 initialised to a buffer of size CONFIG_PRE_CON_BUF_SZ
946 bytes located at CONFIG_PRE_CON_BUF_ADDR. The buffer is
947 a circular buffer, so if more than CONFIG_PRE_CON_BUF_SZ
948 bytes are output before the console is initialised, the
949 earlier bytes are discarded.
951 Note that when printing the buffer a copy is made on the
952 stack so CONFIG_PRE_CON_BUF_SZ must fit on the stack.
954 'Sane' compilers will generate smaller code if
955 CONFIG_PRE_CON_BUF_SZ is a power of 2
957 - Safe printf() functions
958 Define CONFIG_SYS_VSNPRINTF to compile in safe versions of
959 the printf() functions. These are defined in
960 include/vsprintf.h and include snprintf(), vsnprintf() and
961 so on. Code size increase is approximately 300-500 bytes.
962 If this option is not given then these functions will
963 silently discard their buffer size argument - this means
964 you are not getting any overflow checking in this case.
966 - Boot Delay: CONFIG_BOOTDELAY - in seconds
967 Delay before automatically booting the default image;
968 set to -1 to disable autoboot.
969 set to -2 to autoboot with no delay and not check for abort
970 (even when CONFIG_ZERO_BOOTDELAY_CHECK is defined).
972 See doc/README.autoboot for these options that
973 work with CONFIG_BOOTDELAY. None are required.
974 CONFIG_BOOT_RETRY_TIME
975 CONFIG_BOOT_RETRY_MIN
976 CONFIG_AUTOBOOT_KEYED
977 CONFIG_AUTOBOOT_PROMPT
978 CONFIG_AUTOBOOT_DELAY_STR
979 CONFIG_AUTOBOOT_STOP_STR
980 CONFIG_ZERO_BOOTDELAY_CHECK
981 CONFIG_RESET_TO_RETRY
985 Only needed when CONFIG_BOOTDELAY is enabled;
986 define a command string that is automatically executed
987 when no character is read on the console interface
988 within "Boot Delay" after reset.
991 This can be used to pass arguments to the bootm
992 command. The value of CONFIG_BOOTARGS goes into the
993 environment value "bootargs".
995 CONFIG_RAMBOOT and CONFIG_NFSBOOT
996 The value of these goes into the environment as
997 "ramboot" and "nfsboot" respectively, and can be used
998 as a convenience, when switching between booting from
1002 CONFIG_BOOTCOUNT_LIMIT
1003 Implements a mechanism for detecting a repeating reboot
1005 http://www.denx.de/wiki/view/DULG/UBootBootCountLimit
1007 CONFIG_BOOTCOUNT_ENV
1008 If no softreset save registers are found on the hardware
1009 "bootcount" is stored in the environment. To prevent a
1010 saveenv on all reboots, the environment variable
1011 "upgrade_available" is used. If "upgrade_available" is
1012 0, "bootcount" is always 0, if "upgrade_available" is
1013 1 "bootcount" is incremented in the environment.
1014 So the Userspace Applikation must set the "upgrade_available"
1015 and "bootcount" variable to 0, if a boot was successfully.
1017 - Pre-Boot Commands:
1020 When this option is #defined, the existence of the
1021 environment variable "preboot" will be checked
1022 immediately before starting the CONFIG_BOOTDELAY
1023 countdown and/or running the auto-boot command resp.
1024 entering interactive mode.
1026 This feature is especially useful when "preboot" is
1027 automatically generated or modified. For an example
1028 see the LWMON board specific code: here "preboot" is
1029 modified when the user holds down a certain
1030 combination of keys on the (special) keyboard when
1033 - Serial Download Echo Mode:
1035 If defined to 1, all characters received during a
1036 serial download (using the "loads" command) are
1037 echoed back. This might be needed by some terminal
1038 emulations (like "cu"), but may as well just take
1039 time on others. This setting #define's the initial
1040 value of the "loads_echo" environment variable.
1042 - Kgdb Serial Baudrate: (if CONFIG_CMD_KGDB is defined)
1043 CONFIG_KGDB_BAUDRATE
1044 Select one of the baudrates listed in
1045 CONFIG_SYS_BAUDRATE_TABLE, see below.
1047 - Monitor Functions:
1048 Monitor commands can be included or excluded
1049 from the build by using the #include files
1050 <config_cmd_all.h> and #undef'ing unwanted
1051 commands, or adding #define's for wanted commands.
1053 The default command configuration includes all commands
1054 except those marked below with a "*".
1056 CONFIG_CMD_AES AES 128 CBC encrypt/decrypt
1057 CONFIG_CMD_ASKENV * ask for env variable
1058 CONFIG_CMD_BDI bdinfo
1059 CONFIG_CMD_BEDBUG * Include BedBug Debugger
1060 CONFIG_CMD_BMP * BMP support
1061 CONFIG_CMD_BSP * Board specific commands
1062 CONFIG_CMD_BOOTD bootd
1063 CONFIG_CMD_BOOTI * ARM64 Linux kernel Image support
1064 CONFIG_CMD_CACHE * icache, dcache
1065 CONFIG_CMD_CLK * clock command support
1066 CONFIG_CMD_CONSOLE coninfo
1067 CONFIG_CMD_CRC32 * crc32
1068 CONFIG_CMD_DATE * support for RTC, date/time...
1069 CONFIG_CMD_DHCP * DHCP support
1070 CONFIG_CMD_DIAG * Diagnostics
1071 CONFIG_CMD_DS4510 * ds4510 I2C gpio commands
1072 CONFIG_CMD_DS4510_INFO * ds4510 I2C info command
1073 CONFIG_CMD_DS4510_MEM * ds4510 I2C eeprom/sram commansd
1074 CONFIG_CMD_DS4510_RST * ds4510 I2C rst command
1075 CONFIG_CMD_DTT * Digital Therm and Thermostat
1076 CONFIG_CMD_ECHO echo arguments
1077 CONFIG_CMD_EDITENV edit env variable
1078 CONFIG_CMD_EEPROM * EEPROM read/write support
1079 CONFIG_CMD_ELF * bootelf, bootvx
1080 CONFIG_CMD_ENV_CALLBACK * display details about env callbacks
1081 CONFIG_CMD_ENV_FLAGS * display details about env flags
1082 CONFIG_CMD_ENV_EXISTS * check existence of env variable
1083 CONFIG_CMD_EXPORTENV * export the environment
1084 CONFIG_CMD_EXT2 * ext2 command support
1085 CONFIG_CMD_EXT4 * ext4 command support
1086 CONFIG_CMD_FS_GENERIC * filesystem commands (e.g. load, ls)
1087 that work for multiple fs types
1088 CONFIG_CMD_FS_UUID * Look up a filesystem UUID
1089 CONFIG_CMD_SAVEENV saveenv
1090 CONFIG_CMD_FDC * Floppy Disk Support
1091 CONFIG_CMD_FAT * FAT command support
1092 CONFIG_CMD_FLASH flinfo, erase, protect
1093 CONFIG_CMD_FPGA FPGA device initialization support
1094 CONFIG_CMD_FUSE * Device fuse support
1095 CONFIG_CMD_GETTIME * Get time since boot
1096 CONFIG_CMD_GO * the 'go' command (exec code)
1097 CONFIG_CMD_GREPENV * search environment
1098 CONFIG_CMD_HASH * calculate hash / digest
1099 CONFIG_CMD_HWFLOW * RTS/CTS hw flow control
1100 CONFIG_CMD_I2C * I2C serial bus support
1101 CONFIG_CMD_IDE * IDE harddisk support
1102 CONFIG_CMD_IMI iminfo
1103 CONFIG_CMD_IMLS List all images found in NOR flash
1104 CONFIG_CMD_IMLS_NAND * List all images found in NAND flash
1105 CONFIG_CMD_IMMAP * IMMR dump support
1106 CONFIG_CMD_IOTRACE * I/O tracing for debugging
1107 CONFIG_CMD_IMPORTENV * import an environment
1108 CONFIG_CMD_INI * import data from an ini file into the env
1109 CONFIG_CMD_IRQ * irqinfo
1110 CONFIG_CMD_ITEST Integer/string test of 2 values
1111 CONFIG_CMD_JFFS2 * JFFS2 Support
1112 CONFIG_CMD_KGDB * kgdb
1113 CONFIG_CMD_LDRINFO * ldrinfo (display Blackfin loader)
1114 CONFIG_CMD_LINK_LOCAL * link-local IP address auto-configuration
1116 CONFIG_CMD_LOADB loadb
1117 CONFIG_CMD_LOADS loads
1118 CONFIG_CMD_MD5SUM * print md5 message digest
1119 (requires CONFIG_CMD_MEMORY and CONFIG_MD5)
1120 CONFIG_CMD_MEMINFO * Display detailed memory information
1121 CONFIG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base,
1123 CONFIG_CMD_MEMTEST * mtest
1124 CONFIG_CMD_MISC Misc functions like sleep etc
1125 CONFIG_CMD_MMC * MMC memory mapped support
1126 CONFIG_CMD_MII * MII utility commands
1127 CONFIG_CMD_MTDPARTS * MTD partition support
1128 CONFIG_CMD_NAND * NAND support
1129 CONFIG_CMD_NET bootp, tftpboot, rarpboot
1130 CONFIG_CMD_NFS NFS support
1131 CONFIG_CMD_PCA953X * PCA953x I2C gpio commands
1132 CONFIG_CMD_PCA953X_INFO * PCA953x I2C gpio info command
1133 CONFIG_CMD_PCI * pciinfo
1134 CONFIG_CMD_PCMCIA * PCMCIA support
1135 CONFIG_CMD_PING * send ICMP ECHO_REQUEST to network
1137 CONFIG_CMD_PORTIO * Port I/O
1138 CONFIG_CMD_READ * Read raw data from partition
1139 CONFIG_CMD_REGINFO * Register dump
1140 CONFIG_CMD_RUN run command in env variable
1141 CONFIG_CMD_SANDBOX * sb command to access sandbox features
1142 CONFIG_CMD_SAVES * save S record dump
1143 CONFIG_CMD_SCSI * SCSI Support
1144 CONFIG_CMD_SDRAM * print SDRAM configuration information
1145 (requires CONFIG_CMD_I2C)
1146 CONFIG_CMD_SETGETDCR Support for DCR Register access
1148 CONFIG_CMD_SF * Read/write/erase SPI NOR flash
1149 CONFIG_CMD_SHA1SUM * print sha1 memory digest
1150 (requires CONFIG_CMD_MEMORY)
1151 CONFIG_CMD_SOFTSWITCH * Soft switch setting command for BF60x
1152 CONFIG_CMD_SOURCE "source" command Support
1153 CONFIG_CMD_SPI * SPI serial bus support
1154 CONFIG_CMD_TFTPSRV * TFTP transfer in server mode
1155 CONFIG_CMD_TFTPPUT * TFTP put command (upload)
1156 CONFIG_CMD_TIME * run command and report execution time (ARM specific)
1157 CONFIG_CMD_TIMER * access to the system tick timer
1158 CONFIG_CMD_USB * USB support
1159 CONFIG_CMD_CDP * Cisco Discover Protocol support
1160 CONFIG_CMD_MFSL * Microblaze FSL support
1161 CONFIG_CMD_XIMG Load part of Multi Image
1162 CONFIG_CMD_UUID * Generate random UUID or GUID string
1164 EXAMPLE: If you want all functions except of network
1165 support you can write:
1167 #include "config_cmd_all.h"
1168 #undef CONFIG_CMD_NET
1171 fdt (flattened device tree) command: CONFIG_OF_LIBFDT
1173 Note: Don't enable the "icache" and "dcache" commands
1174 (configuration option CONFIG_CMD_CACHE) unless you know
1175 what you (and your U-Boot users) are doing. Data
1176 cache cannot be enabled on systems like the 8xx or
1177 8260 (where accesses to the IMMR region must be
1178 uncached), and it cannot be disabled on all other
1179 systems where we (mis-) use the data cache to hold an
1180 initial stack and some data.
1183 XXX - this list needs to get updated!
1185 - Regular expression support:
1187 If this variable is defined, U-Boot is linked against
1188 the SLRE (Super Light Regular Expression) library,
1189 which adds regex support to some commands, as for
1190 example "env grep" and "setexpr".
1194 If this variable is defined, U-Boot will use a device tree
1195 to configure its devices, instead of relying on statically
1196 compiled #defines in the board file. This option is
1197 experimental and only available on a few boards. The device
1198 tree is available in the global data as gd->fdt_blob.
1200 U-Boot needs to get its device tree from somewhere. This can
1201 be done using one of the two options below:
1204 If this variable is defined, U-Boot will embed a device tree
1205 binary in its image. This device tree file should be in the
1206 board directory and called <soc>-<board>.dts. The binary file
1207 is then picked up in board_init_f() and made available through
1208 the global data structure as gd->blob.
1211 If this variable is defined, U-Boot will build a device tree
1212 binary. It will be called u-boot.dtb. Architecture-specific
1213 code will locate it at run-time. Generally this works by:
1215 cat u-boot.bin u-boot.dtb >image.bin
1217 and in fact, U-Boot does this for you, creating a file called
1218 u-boot-dtb.bin which is useful in the common case. You can
1219 still use the individual files if you need something more
1224 If this variable is defined, it enables watchdog
1225 support for the SoC. There must be support in the SoC
1226 specific code for a watchdog. For the 8xx and 8260
1227 CPUs, the SIU Watchdog feature is enabled in the SYPCR
1228 register. When supported for a specific SoC is
1229 available, then no further board specific code should
1230 be needed to use it.
1233 When using a watchdog circuitry external to the used
1234 SoC, then define this variable and provide board
1235 specific code for the "hw_watchdog_reset" function.
1237 CONFIG_AT91_HW_WDT_TIMEOUT
1238 specify the timeout in seconds. default 2 seconds.
1241 CONFIG_VERSION_VARIABLE
1242 If this variable is defined, an environment variable
1243 named "ver" is created by U-Boot showing the U-Boot
1244 version as printed by the "version" command.
1245 Any change to this variable will be reverted at the
1250 When CONFIG_CMD_DATE is selected, the type of the RTC
1251 has to be selected, too. Define exactly one of the
1254 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx
1255 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC
1256 CONFIG_RTC_MC13XXX - use MC13783 or MC13892 RTC
1257 CONFIG_RTC_MC146818 - use MC146818 RTC
1258 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC
1259 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC
1260 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC
1261 CONFIG_RTC_DS1339 - use Maxim, Inc. DS1339 RTC
1262 CONFIG_RTC_DS164x - use Dallas DS164x RTC
1263 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC
1264 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC
1265 CONFIG_SYS_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337
1266 CONFIG_SYS_RV3029_TCR - enable trickle charger on
1269 Note that if the RTC uses I2C, then the I2C interface
1270 must also be configured. See I2C Support, below.
1273 CONFIG_PCA953X - use NXP's PCA953X series I2C GPIO
1275 The CONFIG_SYS_I2C_PCA953X_WIDTH option specifies a list of
1276 chip-ngpio pairs that tell the PCA953X driver the number of
1277 pins supported by a particular chip.
1279 Note that if the GPIO device uses I2C, then the I2C interface
1280 must also be configured. See I2C Support, below.
1283 When CONFIG_IO_TRACE is selected, U-Boot intercepts all I/O
1284 accesses and can checksum them or write a list of them out
1285 to memory. See the 'iotrace' command for details. This is
1286 useful for testing device drivers since it can confirm that
1287 the driver behaves the same way before and after a code
1288 change. Currently this is supported on sandbox and arm. To
1289 add support for your architecture, add '#include <iotrace.h>'
1290 to the bottom of arch/<arch>/include/asm/io.h and test.
1292 Example output from the 'iotrace stats' command is below.
1293 Note that if the trace buffer is exhausted, the checksum will
1294 still continue to operate.
1297 Start: 10000000 (buffer start address)
1298 Size: 00010000 (buffer size)
1299 Offset: 00000120 (current buffer offset)
1300 Output: 10000120 (start + offset)
1301 Count: 00000018 (number of trace records)
1302 CRC32: 9526fb66 (CRC32 of all trace records)
1304 - Timestamp Support:
1306 When CONFIG_TIMESTAMP is selected, the timestamp
1307 (date and time) of an image is printed by image
1308 commands like bootm or iminfo. This option is
1309 automatically enabled when you select CONFIG_CMD_DATE .
1311 - Partition Labels (disklabels) Supported:
1312 Zero or more of the following:
1313 CONFIG_MAC_PARTITION Apple's MacOS partition table.
1314 CONFIG_DOS_PARTITION MS Dos partition table, traditional on the
1315 Intel architecture, USB sticks, etc.
1316 CONFIG_ISO_PARTITION ISO partition table, used on CDROM etc.
1317 CONFIG_EFI_PARTITION GPT partition table, common when EFI is the
1318 bootloader. Note 2TB partition limit; see
1320 CONFIG_MTD_PARTITIONS Memory Technology Device partition table.
1322 If IDE or SCSI support is enabled (CONFIG_CMD_IDE or
1323 CONFIG_CMD_SCSI) you must configure support for at
1324 least one non-MTD partition type as well.
1327 CONFIG_IDE_RESET_ROUTINE - this is defined in several
1328 board configurations files but used nowhere!
1330 CONFIG_IDE_RESET - is this is defined, IDE Reset will
1331 be performed by calling the function
1332 ide_set_reset(int reset)
1333 which has to be defined in a board specific file
1338 Set this to enable ATAPI support.
1343 Set this to enable support for disks larger than 137GB
1344 Also look at CONFIG_SYS_64BIT_LBA.
1345 Whithout these , LBA48 support uses 32bit variables and will 'only'
1346 support disks up to 2.1TB.
1348 CONFIG_SYS_64BIT_LBA:
1349 When enabled, makes the IDE subsystem use 64bit sector addresses.
1353 At the moment only there is only support for the
1354 SYM53C8XX SCSI controller; define
1355 CONFIG_SCSI_SYM53C8XX to enable it.
1357 CONFIG_SYS_SCSI_MAX_LUN [8], CONFIG_SYS_SCSI_MAX_SCSI_ID [7] and
1358 CONFIG_SYS_SCSI_MAX_DEVICE [CONFIG_SYS_SCSI_MAX_SCSI_ID *
1359 CONFIG_SYS_SCSI_MAX_LUN] can be adjusted to define the
1360 maximum numbers of LUNs, SCSI ID's and target
1362 CONFIG_SYS_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz)
1364 The environment variable 'scsidevs' is set to the number of
1365 SCSI devices found during the last scan.
1367 - NETWORK Support (PCI):
1369 Support for Intel 8254x/8257x gigabit chips.
1372 Utility code for direct access to the SPI bus on Intel 8257x.
1373 This does not do anything useful unless you set at least one
1374 of CONFIG_CMD_E1000 or CONFIG_E1000_SPI_GENERIC.
1376 CONFIG_E1000_SPI_GENERIC
1377 Allow generic access to the SPI bus on the Intel 8257x, for
1378 example with the "sspi" command.
1381 Management command for E1000 devices. When used on devices
1382 with SPI support you can reprogram the EEPROM from U-Boot.
1384 CONFIG_E1000_FALLBACK_MAC
1385 default MAC for empty EEPROM after production.
1388 Support for Intel 82557/82559/82559ER chips.
1389 Optional CONFIG_EEPRO100_SROM_WRITE enables EEPROM
1390 write routine for first time initialisation.
1393 Support for Digital 2114x chips.
1394 Optional CONFIG_TULIP_SELECT_MEDIA for board specific
1395 modem chip initialisation (KS8761/QS6611).
1398 Support for National dp83815 chips.
1401 Support for National dp8382[01] gigabit chips.
1403 - NETWORK Support (other):
1405 CONFIG_DRIVER_AT91EMAC
1406 Support for AT91RM9200 EMAC.
1409 Define this to use reduced MII inteface
1411 CONFIG_DRIVER_AT91EMAC_QUIET
1412 If this defined, the driver is quiet.
1413 The driver doen't show link status messages.
1415 CONFIG_CALXEDA_XGMAC
1416 Support for the Calxeda XGMAC device
1419 Support for SMSC's LAN91C96 chips.
1421 CONFIG_LAN91C96_BASE
1422 Define this to hold the physical address
1423 of the LAN91C96's I/O space
1425 CONFIG_LAN91C96_USE_32_BIT
1426 Define this to enable 32 bit addressing
1429 Support for SMSC's LAN91C111 chip
1431 CONFIG_SMC91111_BASE
1432 Define this to hold the physical address
1433 of the device (I/O space)
1435 CONFIG_SMC_USE_32_BIT
1436 Define this if data bus is 32 bits
1438 CONFIG_SMC_USE_IOFUNCS
1439 Define this to use i/o functions instead of macros
1440 (some hardware wont work with macros)
1442 CONFIG_DRIVER_TI_EMAC
1443 Support for davinci emac
1445 CONFIG_SYS_DAVINCI_EMAC_PHY_COUNT
1446 Define this if you have more then 3 PHYs.
1449 Support for Faraday's FTGMAC100 Gigabit SoC Ethernet
1451 CONFIG_FTGMAC100_EGIGA
1452 Define this to use GE link update with gigabit PHY.
1453 Define this if FTGMAC100 is connected to gigabit PHY.
1454 If your system has 10/100 PHY only, it might not occur
1455 wrong behavior. Because PHY usually return timeout or
1456 useless data when polling gigabit status and gigabit
1457 control registers. This behavior won't affect the
1458 correctnessof 10/100 link speed update.
1461 Support for SMSC's LAN911x and LAN921x chips
1464 Define this to hold the physical address
1465 of the device (I/O space)
1467 CONFIG_SMC911X_32_BIT
1468 Define this if data bus is 32 bits
1470 CONFIG_SMC911X_16_BIT
1471 Define this if data bus is 16 bits. If your processor
1472 automatically converts one 32 bit word to two 16 bit
1473 words you may also try CONFIG_SMC911X_32_BIT.
1476 Support for Renesas on-chip Ethernet controller
1478 CONFIG_SH_ETHER_USE_PORT
1479 Define the number of ports to be used
1481 CONFIG_SH_ETHER_PHY_ADDR
1482 Define the ETH PHY's address
1484 CONFIG_SH_ETHER_CACHE_WRITEBACK
1485 If this option is set, the driver enables cache flush.
1489 Support for PWM modul on the imx6.
1493 Support TPM devices.
1496 Support for i2c bus TPM devices. Only one device
1497 per system is supported at this time.
1499 CONFIG_TPM_TIS_I2C_BUS_NUMBER
1500 Define the the i2c bus number for the TPM device
1502 CONFIG_TPM_TIS_I2C_SLAVE_ADDRESS
1503 Define the TPM's address on the i2c bus
1505 CONFIG_TPM_TIS_I2C_BURST_LIMITATION
1506 Define the burst count bytes upper limit
1508 CONFIG_TPM_ATMEL_TWI
1509 Support for Atmel TWI TPM device. Requires I2C support.
1512 Support for generic parallel port TPM devices. Only one device
1513 per system is supported at this time.
1515 CONFIG_TPM_TIS_BASE_ADDRESS
1516 Base address where the generic TPM device is mapped
1517 to. Contemporary x86 systems usually map it at
1521 Add tpm monitor functions.
1522 Requires CONFIG_TPM. If CONFIG_TPM_AUTH_SESSIONS is set, also
1523 provides monitor access to authorized functions.
1526 Define this to enable the TPM support library which provides
1527 functional interfaces to some TPM commands.
1528 Requires support for a TPM device.
1530 CONFIG_TPM_AUTH_SESSIONS
1531 Define this to enable authorized functions in the TPM library.
1532 Requires CONFIG_TPM and CONFIG_SHA1.
1535 At the moment only the UHCI host controller is
1536 supported (PIP405, MIP405, MPC5200); define
1537 CONFIG_USB_UHCI to enable it.
1538 define CONFIG_USB_KEYBOARD to enable the USB Keyboard
1539 and define CONFIG_USB_STORAGE to enable the USB
1542 Supported are USB Keyboards and USB Floppy drives
1544 MPC5200 USB requires additional defines:
1546 for 528 MHz Clock: 0x0001bbbb
1550 for differential drivers: 0x00001000
1551 for single ended drivers: 0x00005000
1552 for differential drivers on PSC3: 0x00000100
1553 for single ended drivers on PSC3: 0x00004100
1554 CONFIG_SYS_USB_EVENT_POLL
1555 May be defined to allow interrupt polling
1556 instead of using asynchronous interrupts
1558 CONFIG_USB_EHCI_TXFIFO_THRESH enables setting of the
1559 txfilltuning field in the EHCI controller on reset.
1561 CONFIG_USB_DWC2_REG_ADDR the physical CPU address of the DWC2
1562 HW module registers.
1565 Define the below if you wish to use the USB console.
1566 Once firmware is rebuilt from a serial console issue the
1567 command "setenv stdin usbtty; setenv stdout usbtty" and
1568 attach your USB cable. The Unix command "dmesg" should print
1569 it has found a new device. The environment variable usbtty
1570 can be set to gserial or cdc_acm to enable your device to
1571 appear to a USB host as a Linux gserial device or a
1572 Common Device Class Abstract Control Model serial device.
1573 If you select usbtty = gserial you should be able to enumerate
1575 # modprobe usbserial vendor=0xVendorID product=0xProductID
1576 else if using cdc_acm, simply setting the environment
1577 variable usbtty to be cdc_acm should suffice. The following
1578 might be defined in YourBoardName.h
1581 Define this to build a UDC device
1584 Define this to have a tty type of device available to
1585 talk to the UDC device
1588 Define this to enable the high speed support for usb
1589 device and usbtty. If this feature is enabled, a routine
1590 int is_usbd_high_speed(void)
1591 also needs to be defined by the driver to dynamically poll
1592 whether the enumeration has succeded at high speed or full
1595 CONFIG_SYS_CONSOLE_IS_IN_ENV
1596 Define this if you want stdin, stdout &/or stderr to
1600 CONFIG_SYS_USB_EXTC_CLK 0xBLAH
1601 Derive USB clock from external clock "blah"
1602 - CONFIG_SYS_USB_EXTC_CLK 0x02
1604 CONFIG_SYS_USB_BRG_CLK 0xBLAH
1605 Derive USB clock from brgclk
1606 - CONFIG_SYS_USB_BRG_CLK 0x04
1608 If you have a USB-IF assigned VendorID then you may wish to
1609 define your own vendor specific values either in BoardName.h
1610 or directly in usbd_vendor_info.h. If you don't define
1611 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME,
1612 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot
1613 should pretend to be a Linux device to it's target host.
1615 CONFIG_USBD_MANUFACTURER
1616 Define this string as the name of your company for
1617 - CONFIG_USBD_MANUFACTURER "my company"
1619 CONFIG_USBD_PRODUCT_NAME
1620 Define this string as the name of your product
1621 - CONFIG_USBD_PRODUCT_NAME "acme usb device"
1623 CONFIG_USBD_VENDORID
1624 Define this as your assigned Vendor ID from the USB
1625 Implementors Forum. This *must* be a genuine Vendor ID
1626 to avoid polluting the USB namespace.
1627 - CONFIG_USBD_VENDORID 0xFFFF
1629 CONFIG_USBD_PRODUCTID
1630 Define this as the unique Product ID
1632 - CONFIG_USBD_PRODUCTID 0xFFFF
1634 - ULPI Layer Support:
1635 The ULPI (UTMI Low Pin (count) Interface) PHYs are supported via
1636 the generic ULPI layer. The generic layer accesses the ULPI PHY
1637 via the platform viewport, so you need both the genric layer and
1638 the viewport enabled. Currently only Chipidea/ARC based
1639 viewport is supported.
1640 To enable the ULPI layer support, define CONFIG_USB_ULPI and
1641 CONFIG_USB_ULPI_VIEWPORT in your board configuration file.
1642 If your ULPI phy needs a different reference clock than the
1643 standard 24 MHz then you have to define CONFIG_ULPI_REF_CLK to
1644 the appropriate value in Hz.
1647 The MMC controller on the Intel PXA is supported. To
1648 enable this define CONFIG_MMC. The MMC can be
1649 accessed from the boot prompt by mapping the device
1650 to physical memory similar to flash. Command line is
1651 enabled with CONFIG_CMD_MMC. The MMC driver also works with
1652 the FAT fs. This is enabled with CONFIG_CMD_FAT.
1655 Support for Renesas on-chip MMCIF controller
1657 CONFIG_SH_MMCIF_ADDR
1658 Define the base address of MMCIF registers
1661 Define the clock frequency for MMCIF
1664 Enable the generic MMC driver
1666 CONFIG_SUPPORT_EMMC_BOOT
1667 Enable some additional features of the eMMC boot partitions.
1669 CONFIG_SUPPORT_EMMC_RPMB
1670 Enable the commands for reading, writing and programming the
1671 key for the Replay Protection Memory Block partition in eMMC.
1673 - USB Device Firmware Update (DFU) class support:
1674 CONFIG_USB_FUNCTION_DFU
1675 This enables the USB portion of the DFU USB class
1678 This enables the command "dfu" which is used to have
1679 U-Boot create a DFU class device via USB. This command
1680 requires that the "dfu_alt_info" environment variable be
1681 set and define the alt settings to expose to the host.
1684 This enables support for exposing (e)MMC devices via DFU.
1687 This enables support for exposing NAND devices via DFU.
1690 This enables support for exposing RAM via DFU.
1691 Note: DFU spec refer to non-volatile memory usage, but
1692 allow usages beyond the scope of spec - here RAM usage,
1693 one that would help mostly the developer.
1695 CONFIG_SYS_DFU_DATA_BUF_SIZE
1696 Dfu transfer uses a buffer before writing data to the
1697 raw storage device. Make the size (in bytes) of this buffer
1698 configurable. The size of this buffer is also configurable
1699 through the "dfu_bufsiz" environment variable.
1701 CONFIG_SYS_DFU_MAX_FILE_SIZE
1702 When updating files rather than the raw storage device,
1703 we use a static buffer to copy the file into and then write
1704 the buffer once we've been given the whole file. Define
1705 this to the maximum filesize (in bytes) for the buffer.
1706 Default is 4 MiB if undefined.
1708 DFU_DEFAULT_POLL_TIMEOUT
1709 Poll timeout [ms], is the timeout a device can send to the
1710 host. The host must wait for this timeout before sending
1711 a subsequent DFU_GET_STATUS request to the device.
1713 DFU_MANIFEST_POLL_TIMEOUT
1714 Poll timeout [ms], which the device sends to the host when
1715 entering dfuMANIFEST state. Host waits this timeout, before
1716 sending again an USB request to the device.
1718 - USB Device Android Fastboot support:
1719 CONFIG_USB_FUNCTION_FASTBOOT
1720 This enables the USB part of the fastboot gadget
1723 This enables the command "fastboot" which enables the Android
1724 fastboot mode for the platform's USB device. Fastboot is a USB
1725 protocol for downloading images, flashing and device control
1726 used on Android devices.
1727 See doc/README.android-fastboot for more information.
1729 CONFIG_ANDROID_BOOT_IMAGE
1730 This enables support for booting images which use the Android
1731 image format header.
1733 CONFIG_FASTBOOT_BUF_ADDR
1734 The fastboot protocol requires a large memory buffer for
1735 downloads. Define this to the starting RAM address to use for
1738 CONFIG_FASTBOOT_BUF_SIZE
1739 The fastboot protocol requires a large memory buffer for
1740 downloads. This buffer should be as large as possible for a
1741 platform. Define this to the size available RAM for fastboot.
1743 CONFIG_FASTBOOT_FLASH
1744 The fastboot protocol includes a "flash" command for writing
1745 the downloaded image to a non-volatile storage device. Define
1746 this to enable the "fastboot flash" command.
1748 CONFIG_FASTBOOT_FLASH_MMC_DEV
1749 The fastboot "flash" command requires additional information
1750 regarding the non-volatile storage device. Define this to
1751 the eMMC device that fastboot should use to store the image.
1753 CONFIG_FASTBOOT_GPT_NAME
1754 The fastboot "flash" command supports writing the downloaded
1755 image to the Protective MBR and the Primary GUID Partition
1756 Table. (Additionally, this downloaded image is post-processed
1757 to generate and write the Backup GUID Partition Table.)
1758 This occurs when the specified "partition name" on the
1759 "fastboot flash" command line matches this value.
1760 Default is GPT_ENTRY_NAME (currently "gpt") if undefined.
1762 - Journaling Flash filesystem support:
1763 CONFIG_JFFS2_NAND, CONFIG_JFFS2_NAND_OFF, CONFIG_JFFS2_NAND_SIZE,
1764 CONFIG_JFFS2_NAND_DEV
1765 Define these for a default partition on a NAND device
1767 CONFIG_SYS_JFFS2_FIRST_SECTOR,
1768 CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS
1769 Define these for a default partition on a NOR device
1771 CONFIG_SYS_JFFS_CUSTOM_PART
1772 Define this to create an own partition. You have to provide a
1773 function struct part_info* jffs2_part_info(int part_num)
1775 If you define only one JFFS2 partition you may also want to
1776 #define CONFIG_SYS_JFFS_SINGLE_PART 1
1777 to disable the command chpart. This is the default when you
1778 have not defined a custom partition
1780 - FAT(File Allocation Table) filesystem write function support:
1783 Define this to enable support for saving memory data as a
1784 file in FAT formatted partition.
1786 This will also enable the command "fatwrite" enabling the
1787 user to write files to FAT.
1789 CBFS (Coreboot Filesystem) support
1792 Define this to enable support for reading from a Coreboot
1793 filesystem. Available commands are cbfsinit, cbfsinfo, cbfsls
1796 - FAT(File Allocation Table) filesystem cluster size:
1797 CONFIG_FS_FAT_MAX_CLUSTSIZE
1799 Define the max cluster size for fat operations else
1800 a default value of 65536 will be defined.
1805 Define this to enable standard (PC-Style) keyboard
1809 Standard PC keyboard driver with US (is default) and
1810 GERMAN key layout (switch via environment 'keymap=de') support.
1811 Export function i8042_kbd_init, i8042_tstc and i8042_getc
1812 for cfb_console. Supports cursor blinking.
1815 Enables a Chrome OS keyboard using the CROS_EC interface.
1816 This uses CROS_EC to communicate with a second microcontroller
1817 which provides key scans on request.
1822 Define this to enable video support (for output to
1825 CONFIG_VIDEO_CT69000
1827 Enable Chips & Technologies 69000 Video chip
1829 CONFIG_VIDEO_SMI_LYNXEM
1830 Enable Silicon Motion SMI 712/710/810 Video chip. The
1831 video output is selected via environment 'videoout'
1832 (1 = LCD and 2 = CRT). If videoout is undefined, CRT is
1835 For the CT69000 and SMI_LYNXEM drivers, videomode is
1836 selected via environment 'videomode'. Two different ways
1838 - "videomode=num" 'num' is a standard LiLo mode numbers.
1839 Following standard modes are supported (* is default):
1841 Colors 640x480 800x600 1024x768 1152x864 1280x1024
1842 -------------+---------------------------------------------
1843 8 bits | 0x301* 0x303 0x305 0x161 0x307
1844 15 bits | 0x310 0x313 0x316 0x162 0x319
1845 16 bits | 0x311 0x314 0x317 0x163 0x31A
1846 24 bits | 0x312 0x315 0x318 ? 0x31B
1847 -------------+---------------------------------------------
1848 (i.e. setenv videomode 317; saveenv; reset;)
1850 - "videomode=bootargs" all the video parameters are parsed
1851 from the bootargs. (See drivers/video/videomodes.c)
1854 CONFIG_VIDEO_SED13806
1855 Enable Epson SED13806 driver. This driver supports 8bpp
1856 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP
1857 or CONFIG_VIDEO_SED13806_16BPP
1860 Enable the Freescale DIU video driver. Reference boards for
1861 SOCs that have a DIU should define this macro to enable DIU
1862 support, and should also define these other macros:
1868 CONFIG_VIDEO_SW_CURSOR
1869 CONFIG_VGA_AS_SINGLE_DEVICE
1871 CONFIG_VIDEO_BMP_LOGO
1873 The DIU driver will look for the 'video-mode' environment
1874 variable, and if defined, enable the DIU as a console during
1875 boot. See the documentation file README.video for a
1876 description of this variable.
1882 Define this to enable a custom keyboard support.
1883 This simply calls drv_keyboard_init() which must be
1884 defined in your board-specific files.
1885 The only board using this so far is RBC823.
1887 - LCD Support: CONFIG_LCD
1889 Define this to enable LCD support (for output to LCD
1890 display); also select one of the supported displays
1891 by defining one of these:
1895 HITACHI TX09D70VM1CCA, 3.5", 240x320.
1897 CONFIG_NEC_NL6448AC33:
1899 NEC NL6448AC33-18. Active, color, single scan.
1901 CONFIG_NEC_NL6448BC20
1903 NEC NL6448BC20-08. 6.5", 640x480.
1904 Active, color, single scan.
1906 CONFIG_NEC_NL6448BC33_54
1908 NEC NL6448BC33-54. 10.4", 640x480.
1909 Active, color, single scan.
1913 Sharp 320x240. Active, color, single scan.
1914 It isn't 16x9, and I am not sure what it is.
1916 CONFIG_SHARP_LQ64D341
1918 Sharp LQ64D341 display, 640x480.
1919 Active, color, single scan.
1923 HLD1045 display, 640x480.
1924 Active, color, single scan.
1928 Optrex CBL50840-2 NF-FW 99 22 M5
1930 Hitachi LMG6912RPFC-00T
1934 320x240. Black & white.
1936 Normally display is black on white background; define
1937 CONFIG_SYS_WHITE_ON_BLACK to get it inverted.
1939 CONFIG_LCD_ALIGNMENT
1941 Normally the LCD is page-aligned (typically 4KB). If this is
1942 defined then the LCD will be aligned to this value instead.
1943 For ARM it is sometimes useful to use MMU_SECTION_SIZE
1944 here, since it is cheaper to change data cache settings on
1945 a per-section basis.
1947 CONFIG_CONSOLE_SCROLL_LINES
1949 When the console need to be scrolled, this is the number of
1950 lines to scroll by. It defaults to 1. Increasing this makes
1951 the console jump but can help speed up operation when scrolling
1956 Sometimes, for example if the display is mounted in portrait
1957 mode or even if it's mounted landscape but rotated by 180degree,
1958 we need to rotate our content of the display relative to the
1959 framebuffer, so that user can read the messages which are
1961 Once CONFIG_LCD_ROTATION is defined, the lcd_console will be
1962 initialized with a given rotation from "vl_rot" out of
1963 "vidinfo_t" which is provided by the board specific code.
1964 The value for vl_rot is coded as following (matching to
1965 fbcon=rotate:<n> linux-kernel commandline):
1966 0 = no rotation respectively 0 degree
1967 1 = 90 degree rotation
1968 2 = 180 degree rotation
1969 3 = 270 degree rotation
1971 If CONFIG_LCD_ROTATION is not defined, the console will be
1972 initialized with 0degree rotation.
1976 Support drawing of RLE8-compressed bitmaps on the LCD.
1980 Enables an 'i2c edid' command which can read EDID
1981 information over I2C from an attached LCD display.
1983 - Splash Screen Support: CONFIG_SPLASH_SCREEN
1985 If this option is set, the environment is checked for
1986 a variable "splashimage". If found, the usual display
1987 of logo, copyright and system information on the LCD
1988 is suppressed and the BMP image at the address
1989 specified in "splashimage" is loaded instead. The
1990 console is redirected to the "nulldev", too. This
1991 allows for a "silent" boot where a splash screen is
1992 loaded very quickly after power-on.
1994 CONFIG_SPLASHIMAGE_GUARD
1996 If this option is set, then U-Boot will prevent the environment
1997 variable "splashimage" from being set to a problematic address
1998 (see README.displaying-bmps).
1999 This option is useful for targets where, due to alignment
2000 restrictions, an improperly aligned BMP image will cause a data
2001 abort. If you think you will not have problems with unaligned
2002 accesses (for example because your toolchain prevents them)
2003 there is no need to set this option.
2005 CONFIG_SPLASH_SCREEN_ALIGN
2007 If this option is set the splash image can be freely positioned
2008 on the screen. Environment variable "splashpos" specifies the
2009 position as "x,y". If a positive number is given it is used as
2010 number of pixel from left/top. If a negative number is given it
2011 is used as number of pixel from right/bottom. You can also
2012 specify 'm' for centering the image.
2015 setenv splashpos m,m
2016 => image at center of screen
2018 setenv splashpos 30,20
2019 => image at x = 30 and y = 20
2021 setenv splashpos -10,m
2022 => vertically centered image
2023 at x = dspWidth - bmpWidth - 9
2025 - Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP
2027 If this option is set, additionally to standard BMP
2028 images, gzipped BMP images can be displayed via the
2029 splashscreen support or the bmp command.
2031 - Run length encoded BMP image (RLE8) support: CONFIG_VIDEO_BMP_RLE8
2033 If this option is set, 8-bit RLE compressed BMP images
2034 can be displayed via the splashscreen support or the
2037 - Do compressing for memory range:
2040 If this option is set, it would use zlib deflate method
2041 to compress the specified memory at its best effort.
2043 - Compression support:
2046 Enabled by default to support gzip compressed images.
2050 If this option is set, support for bzip2 compressed
2051 images is included. If not, only uncompressed and gzip
2052 compressed images are supported.
2054 NOTE: the bzip2 algorithm requires a lot of RAM, so
2055 the malloc area (as defined by CONFIG_SYS_MALLOC_LEN) should
2060 If this option is set, support for lzma compressed
2063 Note: The LZMA algorithm adds between 2 and 4KB of code and it
2064 requires an amount of dynamic memory that is given by the
2067 (1846 + 768 << (lc + lp)) * sizeof(uint16)
2069 Where lc and lp stand for, respectively, Literal context bits
2070 and Literal pos bits.
2072 This value is upper-bounded by 14MB in the worst case. Anyway,
2073 for a ~4MB large kernel image, we have lc=3 and lp=0 for a
2074 total amount of (1846 + 768 << (3 + 0)) * 2 = ~41KB... that is
2075 a very small buffer.
2077 Use the lzmainfo tool to determinate the lc and lp values and
2078 then calculate the amount of needed dynamic memory (ensuring
2079 the appropriate CONFIG_SYS_MALLOC_LEN value).
2083 If this option is set, support for LZO compressed images
2089 The address of PHY on MII bus.
2091 CONFIG_PHY_CLOCK_FREQ (ppc4xx)
2093 The clock frequency of the MII bus
2097 If this option is set, support for speed/duplex
2098 detection of gigabit PHY is included.
2100 CONFIG_PHY_RESET_DELAY
2102 Some PHY like Intel LXT971A need extra delay after
2103 reset before any MII register access is possible.
2104 For such PHY, set this option to the usec delay
2105 required. (minimum 300usec for LXT971A)
2107 CONFIG_PHY_CMD_DELAY (ppc4xx)
2109 Some PHY like Intel LXT971A need extra delay after
2110 command issued before MII status register can be read
2115 Define a default value for the IP address to use for
2116 the default Ethernet interface, in case this is not
2117 determined through e.g. bootp.
2118 (Environment variable "ipaddr")
2120 - Server IP address:
2123 Defines a default value for the IP address of a TFTP
2124 server to contact when using the "tftboot" command.
2125 (Environment variable "serverip")
2127 CONFIG_KEEP_SERVERADDR
2129 Keeps the server's MAC address, in the env 'serveraddr'
2130 for passing to bootargs (like Linux's netconsole option)
2132 - Gateway IP address:
2135 Defines a default value for the IP address of the
2136 default router where packets to other networks are
2138 (Environment variable "gatewayip")
2143 Defines a default value for the subnet mask (or
2144 routing prefix) which is used to determine if an IP
2145 address belongs to the local subnet or needs to be
2146 forwarded through a router.
2147 (Environment variable "netmask")
2149 - Multicast TFTP Mode:
2152 Defines whether you want to support multicast TFTP as per
2153 rfc-2090; for example to work with atftp. Lets lots of targets
2154 tftp down the same boot image concurrently. Note: the Ethernet
2155 driver in use must provide a function: mcast() to join/leave a
2158 - BOOTP Recovery Mode:
2159 CONFIG_BOOTP_RANDOM_DELAY
2161 If you have many targets in a network that try to
2162 boot using BOOTP, you may want to avoid that all
2163 systems send out BOOTP requests at precisely the same
2164 moment (which would happen for instance at recovery
2165 from a power failure, when all systems will try to
2166 boot, thus flooding the BOOTP server. Defining
2167 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
2168 inserted before sending out BOOTP requests. The
2169 following delays are inserted then:
2171 1st BOOTP request: delay 0 ... 1 sec
2172 2nd BOOTP request: delay 0 ... 2 sec
2173 3rd BOOTP request: delay 0 ... 4 sec
2175 BOOTP requests: delay 0 ... 8 sec
2177 CONFIG_BOOTP_ID_CACHE_SIZE
2179 BOOTP packets are uniquely identified using a 32-bit ID. The
2180 server will copy the ID from client requests to responses and
2181 U-Boot will use this to determine if it is the destination of
2182 an incoming response. Some servers will check that addresses
2183 aren't in use before handing them out (usually using an ARP
2184 ping) and therefore take up to a few hundred milliseconds to
2185 respond. Network congestion may also influence the time it
2186 takes for a response to make it back to the client. If that
2187 time is too long, U-Boot will retransmit requests. In order
2188 to allow earlier responses to still be accepted after these
2189 retransmissions, U-Boot's BOOTP client keeps a small cache of
2190 IDs. The CONFIG_BOOTP_ID_CACHE_SIZE controls the size of this
2191 cache. The default is to keep IDs for up to four outstanding
2192 requests. Increasing this will allow U-Boot to accept offers
2193 from a BOOTP client in networks with unusually high latency.
2195 - DHCP Advanced Options:
2196 You can fine tune the DHCP functionality by defining
2197 CONFIG_BOOTP_* symbols:
2199 CONFIG_BOOTP_SUBNETMASK
2200 CONFIG_BOOTP_GATEWAY
2201 CONFIG_BOOTP_HOSTNAME
2202 CONFIG_BOOTP_NISDOMAIN
2203 CONFIG_BOOTP_BOOTPATH
2204 CONFIG_BOOTP_BOOTFILESIZE
2207 CONFIG_BOOTP_SEND_HOSTNAME
2208 CONFIG_BOOTP_NTPSERVER
2209 CONFIG_BOOTP_TIMEOFFSET
2210 CONFIG_BOOTP_VENDOREX
2211 CONFIG_BOOTP_MAY_FAIL
2213 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip
2214 environment variable, not the BOOTP server.
2216 CONFIG_BOOTP_MAY_FAIL - If the DHCP server is not found
2217 after the configured retry count, the call will fail
2218 instead of starting over. This can be used to fail over
2219 to Link-local IP address configuration if the DHCP server
2222 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS
2223 serverip from a DHCP server, it is possible that more
2224 than one DNS serverip is offered to the client.
2225 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS
2226 serverip will be stored in the additional environment
2227 variable "dnsip2". The first DNS serverip is always
2228 stored in the variable "dnsip", when CONFIG_BOOTP_DNS
2231 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable
2232 to do a dynamic update of a DNS server. To do this, they
2233 need the hostname of the DHCP requester.
2234 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content
2235 of the "hostname" environment variable is passed as
2236 option 12 to the DHCP server.
2238 CONFIG_BOOTP_DHCP_REQUEST_DELAY
2240 A 32bit value in microseconds for a delay between
2241 receiving a "DHCP Offer" and sending the "DHCP Request".
2242 This fixes a problem with certain DHCP servers that don't
2243 respond 100% of the time to a "DHCP request". E.g. On an
2244 AT91RM9200 processor running at 180MHz, this delay needed
2245 to be *at least* 15,000 usec before a Windows Server 2003
2246 DHCP server would reply 100% of the time. I recommend at
2247 least 50,000 usec to be safe. The alternative is to hope
2248 that one of the retries will be successful but note that
2249 the DHCP timeout and retry process takes a longer than
2252 - Link-local IP address negotiation:
2253 Negotiate with other link-local clients on the local network
2254 for an address that doesn't require explicit configuration.
2255 This is especially useful if a DHCP server cannot be guaranteed
2256 to exist in all environments that the device must operate.
2258 See doc/README.link-local for more information.
2261 CONFIG_CDP_DEVICE_ID
2263 The device id used in CDP trigger frames.
2265 CONFIG_CDP_DEVICE_ID_PREFIX
2267 A two character string which is prefixed to the MAC address
2272 A printf format string which contains the ascii name of
2273 the port. Normally is set to "eth%d" which sets
2274 eth0 for the first Ethernet, eth1 for the second etc.
2276 CONFIG_CDP_CAPABILITIES
2278 A 32bit integer which indicates the device capabilities;
2279 0x00000010 for a normal host which does not forwards.
2283 An ascii string containing the version of the software.
2287 An ascii string containing the name of the platform.
2291 A 32bit integer sent on the trigger.
2293 CONFIG_CDP_POWER_CONSUMPTION
2295 A 16bit integer containing the power consumption of the
2296 device in .1 of milliwatts.
2298 CONFIG_CDP_APPLIANCE_VLAN_TYPE
2300 A byte containing the id of the VLAN.
2302 - Status LED: CONFIG_STATUS_LED
2304 Several configurations allow to display the current
2305 status using a LED. For instance, the LED will blink
2306 fast while running U-Boot code, stop blinking as
2307 soon as a reply to a BOOTP request was received, and
2308 start blinking slow once the Linux kernel is running
2309 (supported by a status LED driver in the Linux
2310 kernel). Defining CONFIG_STATUS_LED enables this
2316 The status LED can be connected to a GPIO pin.
2317 In such cases, the gpio_led driver can be used as a
2318 status LED backend implementation. Define CONFIG_GPIO_LED
2319 to include the gpio_led driver in the U-Boot binary.
2321 CONFIG_GPIO_LED_INVERTED_TABLE
2322 Some GPIO connected LEDs may have inverted polarity in which
2323 case the GPIO high value corresponds to LED off state and
2324 GPIO low value corresponds to LED on state.
2325 In such cases CONFIG_GPIO_LED_INVERTED_TABLE may be defined
2326 with a list of GPIO LEDs that have inverted polarity.
2328 - CAN Support: CONFIG_CAN_DRIVER
2330 Defining CONFIG_CAN_DRIVER enables CAN driver support
2331 on those systems that support this (optional)
2332 feature, like the TQM8xxL modules.
2334 - I2C Support: CONFIG_SYS_I2C
2336 This enable the NEW i2c subsystem, and will allow you to use
2337 i2c commands at the u-boot command line (as long as you set
2338 CONFIG_CMD_I2C in CONFIG_COMMANDS) and communicate with i2c
2339 based realtime clock chips or other i2c devices. See
2340 common/cmd_i2c.c for a description of the command line
2343 ported i2c driver to the new framework:
2344 - drivers/i2c/soft_i2c.c:
2345 - activate first bus with CONFIG_SYS_I2C_SOFT define
2346 CONFIG_SYS_I2C_SOFT_SPEED and CONFIG_SYS_I2C_SOFT_SLAVE
2347 for defining speed and slave address
2348 - activate second bus with I2C_SOFT_DECLARATIONS2 define
2349 CONFIG_SYS_I2C_SOFT_SPEED_2 and CONFIG_SYS_I2C_SOFT_SLAVE_2
2350 for defining speed and slave address
2351 - activate third bus with I2C_SOFT_DECLARATIONS3 define
2352 CONFIG_SYS_I2C_SOFT_SPEED_3 and CONFIG_SYS_I2C_SOFT_SLAVE_3
2353 for defining speed and slave address
2354 - activate fourth bus with I2C_SOFT_DECLARATIONS4 define
2355 CONFIG_SYS_I2C_SOFT_SPEED_4 and CONFIG_SYS_I2C_SOFT_SLAVE_4
2356 for defining speed and slave address
2358 - drivers/i2c/fsl_i2c.c:
2359 - activate i2c driver with CONFIG_SYS_I2C_FSL
2360 define CONFIG_SYS_FSL_I2C_OFFSET for setting the register
2361 offset CONFIG_SYS_FSL_I2C_SPEED for the i2c speed and
2362 CONFIG_SYS_FSL_I2C_SLAVE for the slave addr of the first
2364 - If your board supports a second fsl i2c bus, define
2365 CONFIG_SYS_FSL_I2C2_OFFSET for the register offset
2366 CONFIG_SYS_FSL_I2C2_SPEED for the speed and
2367 CONFIG_SYS_FSL_I2C2_SLAVE for the slave address of the
2370 - drivers/i2c/tegra_i2c.c:
2371 - activate this driver with CONFIG_SYS_I2C_TEGRA
2372 - This driver adds 4 i2c buses with a fix speed from
2373 100000 and the slave addr 0!
2375 - drivers/i2c/ppc4xx_i2c.c
2376 - activate this driver with CONFIG_SYS_I2C_PPC4XX
2377 - CONFIG_SYS_I2C_PPC4XX_CH0 activate hardware channel 0
2378 - CONFIG_SYS_I2C_PPC4XX_CH1 activate hardware channel 1
2380 - drivers/i2c/i2c_mxc.c
2381 - activate this driver with CONFIG_SYS_I2C_MXC
2382 - define speed for bus 1 with CONFIG_SYS_MXC_I2C1_SPEED
2383 - define slave for bus 1 with CONFIG_SYS_MXC_I2C1_SLAVE
2384 - define speed for bus 2 with CONFIG_SYS_MXC_I2C2_SPEED
2385 - define slave for bus 2 with CONFIG_SYS_MXC_I2C2_SLAVE
2386 - define speed for bus 3 with CONFIG_SYS_MXC_I2C3_SPEED
2387 - define slave for bus 3 with CONFIG_SYS_MXC_I2C3_SLAVE
2388 If those defines are not set, default value is 100000
2389 for speed, and 0 for slave.
2390 - enable bus 3 with CONFIG_SYS_I2C_MXC_I2C3
2391 - enable bus 4 with CONFIG_SYS_I2C_MXC_I2C4
2393 - drivers/i2c/rcar_i2c.c:
2394 - activate this driver with CONFIG_SYS_I2C_RCAR
2395 - This driver adds 4 i2c buses
2397 - CONFIG_SYS_RCAR_I2C0_BASE for setting the register channel 0
2398 - CONFIG_SYS_RCAR_I2C0_SPEED for for the speed channel 0
2399 - CONFIG_SYS_RCAR_I2C1_BASE for setting the register channel 1
2400 - CONFIG_SYS_RCAR_I2C1_SPEED for for the speed channel 1
2401 - CONFIG_SYS_RCAR_I2C2_BASE for setting the register channel 2
2402 - CONFIG_SYS_RCAR_I2C2_SPEED for for the speed channel 2
2403 - CONFIG_SYS_RCAR_I2C3_BASE for setting the register channel 3
2404 - CONFIG_SYS_RCAR_I2C3_SPEED for for the speed channel 3
2405 - CONFIF_SYS_RCAR_I2C_NUM_CONTROLLERS for number of i2c buses
2407 - drivers/i2c/sh_i2c.c:
2408 - activate this driver with CONFIG_SYS_I2C_SH
2409 - This driver adds from 2 to 5 i2c buses
2411 - CONFIG_SYS_I2C_SH_BASE0 for setting the register channel 0
2412 - CONFIG_SYS_I2C_SH_SPEED0 for for the speed channel 0
2413 - CONFIG_SYS_I2C_SH_BASE1 for setting the register channel 1
2414 - CONFIG_SYS_I2C_SH_SPEED1 for for the speed channel 1
2415 - CONFIG_SYS_I2C_SH_BASE2 for setting the register channel 2
2416 - CONFIG_SYS_I2C_SH_SPEED2 for for the speed channel 2
2417 - CONFIG_SYS_I2C_SH_BASE3 for setting the register channel 3
2418 - CONFIG_SYS_I2C_SH_SPEED3 for for the speed channel 3
2419 - CONFIG_SYS_I2C_SH_BASE4 for setting the register channel 4
2420 - CONFIG_SYS_I2C_SH_SPEED4 for for the speed channel 4
2421 - CONFIG_SYS_I2C_SH_BASE5 for setting the register channel 5
2422 - CONFIG_SYS_I2C_SH_SPEED5 for for the speed channel 5
2423 - CONFIG_SYS_I2C_SH_NUM_CONTROLLERS for number of i2c buses
2425 - drivers/i2c/omap24xx_i2c.c
2426 - activate this driver with CONFIG_SYS_I2C_OMAP24XX
2427 - CONFIG_SYS_OMAP24_I2C_SPEED speed channel 0
2428 - CONFIG_SYS_OMAP24_I2C_SLAVE slave addr channel 0
2429 - CONFIG_SYS_OMAP24_I2C_SPEED1 speed channel 1
2430 - CONFIG_SYS_OMAP24_I2C_SLAVE1 slave addr channel 1
2431 - CONFIG_SYS_OMAP24_I2C_SPEED2 speed channel 2
2432 - CONFIG_SYS_OMAP24_I2C_SLAVE2 slave addr channel 2
2433 - CONFIG_SYS_OMAP24_I2C_SPEED3 speed channel 3
2434 - CONFIG_SYS_OMAP24_I2C_SLAVE3 slave addr channel 3
2435 - CONFIG_SYS_OMAP24_I2C_SPEED4 speed channel 4
2436 - CONFIG_SYS_OMAP24_I2C_SLAVE4 slave addr channel 4
2438 - drivers/i2c/zynq_i2c.c
2439 - activate this driver with CONFIG_SYS_I2C_ZYNQ
2440 - set CONFIG_SYS_I2C_ZYNQ_SPEED for speed setting
2441 - set CONFIG_SYS_I2C_ZYNQ_SLAVE for slave addr
2443 - drivers/i2c/s3c24x0_i2c.c:
2444 - activate this driver with CONFIG_SYS_I2C_S3C24X0
2445 - This driver adds i2c buses (11 for Exynos5250, Exynos5420
2446 9 i2c buses for Exynos4 and 1 for S3C24X0 SoCs from Samsung)
2447 with a fix speed from 100000 and the slave addr 0!
2449 - drivers/i2c/ihs_i2c.c
2450 - activate this driver with CONFIG_SYS_I2C_IHS
2451 - CONFIG_SYS_I2C_IHS_CH0 activate hardware channel 0
2452 - CONFIG_SYS_I2C_IHS_SPEED_0 speed channel 0
2453 - CONFIG_SYS_I2C_IHS_SLAVE_0 slave addr channel 0
2454 - CONFIG_SYS_I2C_IHS_CH1 activate hardware channel 1
2455 - CONFIG_SYS_I2C_IHS_SPEED_1 speed channel 1
2456 - CONFIG_SYS_I2C_IHS_SLAVE_1 slave addr channel 1
2457 - CONFIG_SYS_I2C_IHS_CH2 activate hardware channel 2
2458 - CONFIG_SYS_I2C_IHS_SPEED_2 speed channel 2
2459 - CONFIG_SYS_I2C_IHS_SLAVE_2 slave addr channel 2
2460 - CONFIG_SYS_I2C_IHS_CH3 activate hardware channel 3
2461 - CONFIG_SYS_I2C_IHS_SPEED_3 speed channel 3
2462 - CONFIG_SYS_I2C_IHS_SLAVE_3 slave addr channel 3
2466 CONFIG_SYS_NUM_I2C_BUSES
2467 Hold the number of i2c buses you want to use. If you
2468 don't use/have i2c muxes on your i2c bus, this
2469 is equal to CONFIG_SYS_NUM_I2C_ADAPTERS, and you can
2472 CONFIG_SYS_I2C_DIRECT_BUS
2473 define this, if you don't use i2c muxes on your hardware.
2474 if CONFIG_SYS_I2C_MAX_HOPS is not defined or == 0 you can
2477 CONFIG_SYS_I2C_MAX_HOPS
2478 define how many muxes are maximal consecutively connected
2479 on one i2c bus. If you not use i2c muxes, omit this
2482 CONFIG_SYS_I2C_BUSES
2483 hold a list of buses you want to use, only used if
2484 CONFIG_SYS_I2C_DIRECT_BUS is not defined, for example
2485 a board with CONFIG_SYS_I2C_MAX_HOPS = 1 and
2486 CONFIG_SYS_NUM_I2C_BUSES = 9:
2488 CONFIG_SYS_I2C_BUSES {{0, {I2C_NULL_HOP}}, \
2489 {0, {{I2C_MUX_PCA9547, 0x70, 1}}}, \
2490 {0, {{I2C_MUX_PCA9547, 0x70, 2}}}, \
2491 {0, {{I2C_MUX_PCA9547, 0x70, 3}}}, \
2492 {0, {{I2C_MUX_PCA9547, 0x70, 4}}}, \
2493 {0, {{I2C_MUX_PCA9547, 0x70, 5}}}, \
2494 {1, {I2C_NULL_HOP}}, \
2495 {1, {{I2C_MUX_PCA9544, 0x72, 1}}}, \
2496 {1, {{I2C_MUX_PCA9544, 0x72, 2}}}, \
2500 bus 0 on adapter 0 without a mux
2501 bus 1 on adapter 0 with a PCA9547 on address 0x70 port 1
2502 bus 2 on adapter 0 with a PCA9547 on address 0x70 port 2
2503 bus 3 on adapter 0 with a PCA9547 on address 0x70 port 3
2504 bus 4 on adapter 0 with a PCA9547 on address 0x70 port 4
2505 bus 5 on adapter 0 with a PCA9547 on address 0x70 port 5
2506 bus 6 on adapter 1 without a mux
2507 bus 7 on adapter 1 with a PCA9544 on address 0x72 port 1
2508 bus 8 on adapter 1 with a PCA9544 on address 0x72 port 2
2510 If you do not have i2c muxes on your board, omit this define.
2512 - Legacy I2C Support: CONFIG_HARD_I2C
2514 NOTE: It is intended to move drivers to CONFIG_SYS_I2C which
2515 provides the following compelling advantages:
2517 - more than one i2c adapter is usable
2518 - approved multibus support
2519 - better i2c mux support
2521 ** Please consider updating your I2C driver now. **
2523 These enable legacy I2C serial bus commands. Defining
2524 CONFIG_HARD_I2C will include the appropriate I2C driver
2525 for the selected CPU.
2527 This will allow you to use i2c commands at the u-boot
2528 command line (as long as you set CONFIG_CMD_I2C in
2529 CONFIG_COMMANDS) and communicate with i2c based realtime
2530 clock chips. See common/cmd_i2c.c for a description of the
2531 command line interface.
2533 CONFIG_HARD_I2C selects a hardware I2C controller.
2535 There are several other quantities that must also be
2536 defined when you define CONFIG_HARD_I2C.
2538 In both cases you will need to define CONFIG_SYS_I2C_SPEED
2539 to be the frequency (in Hz) at which you wish your i2c bus
2540 to run and CONFIG_SYS_I2C_SLAVE to be the address of this node (ie
2541 the CPU's i2c node address).
2543 Now, the u-boot i2c code for the mpc8xx
2544 (arch/powerpc/cpu/mpc8xx/i2c.c) sets the CPU up as a master node
2545 and so its address should therefore be cleared to 0 (See,
2546 eg, MPC823e User's Manual p.16-473). So, set
2547 CONFIG_SYS_I2C_SLAVE to 0.
2549 CONFIG_SYS_I2C_INIT_MPC5XXX
2551 When a board is reset during an i2c bus transfer
2552 chips might think that the current transfer is still
2553 in progress. Reset the slave devices by sending start
2554 commands until the slave device responds.
2556 That's all that's required for CONFIG_HARD_I2C.
2558 If you use the software i2c interface (CONFIG_SYS_I2C_SOFT)
2559 then the following macros need to be defined (examples are
2560 from include/configs/lwmon.h):
2564 (Optional). Any commands necessary to enable the I2C
2565 controller or configure ports.
2567 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
2571 (Only for MPC8260 CPU). The I/O port to use (the code
2572 assumes both bits are on the same port). Valid values
2573 are 0..3 for ports A..D.
2577 The code necessary to make the I2C data line active
2578 (driven). If the data line is open collector, this
2581 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
2585 The code necessary to make the I2C data line tri-stated
2586 (inactive). If the data line is open collector, this
2589 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
2593 Code that returns true if the I2C data line is high,
2596 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
2600 If <bit> is true, sets the I2C data line high. If it
2601 is false, it clears it (low).
2603 eg: #define I2C_SDA(bit) \
2604 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
2605 else immr->im_cpm.cp_pbdat &= ~PB_SDA
2609 If <bit> is true, sets the I2C clock line high. If it
2610 is false, it clears it (low).
2612 eg: #define I2C_SCL(bit) \
2613 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
2614 else immr->im_cpm.cp_pbdat &= ~PB_SCL
2618 This delay is invoked four times per clock cycle so this
2619 controls the rate of data transfer. The data rate thus
2620 is 1 / (I2C_DELAY * 4). Often defined to be something
2623 #define I2C_DELAY udelay(2)
2625 CONFIG_SOFT_I2C_GPIO_SCL / CONFIG_SOFT_I2C_GPIO_SDA
2627 If your arch supports the generic GPIO framework (asm/gpio.h),
2628 then you may alternatively define the two GPIOs that are to be
2629 used as SCL / SDA. Any of the previous I2C_xxx macros will
2630 have GPIO-based defaults assigned to them as appropriate.
2632 You should define these to the GPIO value as given directly to
2633 the generic GPIO functions.
2635 CONFIG_SYS_I2C_INIT_BOARD
2637 When a board is reset during an i2c bus transfer
2638 chips might think that the current transfer is still
2639 in progress. On some boards it is possible to access
2640 the i2c SCLK line directly, either by using the
2641 processor pin as a GPIO or by having a second pin
2642 connected to the bus. If this option is defined a
2643 custom i2c_init_board() routine in boards/xxx/board.c
2644 is run early in the boot sequence.
2646 CONFIG_SYS_I2C_BOARD_LATE_INIT
2648 An alternative to CONFIG_SYS_I2C_INIT_BOARD. If this option is
2649 defined a custom i2c_board_late_init() routine in
2650 boards/xxx/board.c is run AFTER the operations in i2c_init()
2651 is completed. This callpoint can be used to unreset i2c bus
2652 using CPU i2c controller register accesses for CPUs whose i2c
2653 controller provide such a method. It is called at the end of
2654 i2c_init() to allow i2c_init operations to setup the i2c bus
2655 controller on the CPU (e.g. setting bus speed & slave address).
2657 CONFIG_I2CFAST (PPC405GP|PPC405EP only)
2659 This option enables configuration of bi_iic_fast[] flags
2660 in u-boot bd_info structure based on u-boot environment
2661 variable "i2cfast". (see also i2cfast)
2663 CONFIG_I2C_MULTI_BUS
2665 This option allows the use of multiple I2C buses, each of which
2666 must have a controller. At any point in time, only one bus is
2667 active. To switch to a different bus, use the 'i2c dev' command.
2668 Note that bus numbering is zero-based.
2670 CONFIG_SYS_I2C_NOPROBES
2672 This option specifies a list of I2C devices that will be skipped
2673 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS
2674 is set, specify a list of bus-device pairs. Otherwise, specify
2675 a 1D array of device addresses
2678 #undef CONFIG_I2C_MULTI_BUS
2679 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68}
2681 will skip addresses 0x50 and 0x68 on a board with one I2C bus
2683 #define CONFIG_I2C_MULTI_BUS
2684 #define CONFIG_SYS_I2C_MULTI_NOPROBES {{0,0x50},{0,0x68},{1,0x54}}
2686 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1
2688 CONFIG_SYS_SPD_BUS_NUM
2690 If defined, then this indicates the I2C bus number for DDR SPD.
2691 If not defined, then U-Boot assumes that SPD is on I2C bus 0.
2693 CONFIG_SYS_RTC_BUS_NUM
2695 If defined, then this indicates the I2C bus number for the RTC.
2696 If not defined, then U-Boot assumes that RTC is on I2C bus 0.
2698 CONFIG_SYS_DTT_BUS_NUM
2700 If defined, then this indicates the I2C bus number for the DTT.
2701 If not defined, then U-Boot assumes that DTT is on I2C bus 0.
2703 CONFIG_SYS_I2C_DTT_ADDR:
2705 If defined, specifies the I2C address of the DTT device.
2706 If not defined, then U-Boot uses predefined value for
2707 specified DTT device.
2709 CONFIG_SOFT_I2C_READ_REPEATED_START
2711 defining this will force the i2c_read() function in
2712 the soft_i2c driver to perform an I2C repeated start
2713 between writing the address pointer and reading the
2714 data. If this define is omitted the default behaviour
2715 of doing a stop-start sequence will be used. Most I2C
2716 devices can use either method, but some require one or
2719 - SPI Support: CONFIG_SPI
2721 Enables SPI driver (so far only tested with
2722 SPI EEPROM, also an instance works with Crystal A/D and
2723 D/As on the SACSng board)
2727 Enables the driver for SPI controller on SuperH. Currently
2728 only SH7757 is supported.
2732 Enables extended (16-bit) SPI EEPROM addressing.
2733 (symmetrical to CONFIG_I2C_X)
2737 Enables a software (bit-bang) SPI driver rather than
2738 using hardware support. This is a general purpose
2739 driver that only requires three general I/O port pins
2740 (two outputs, one input) to function. If this is
2741 defined, the board configuration must define several
2742 SPI configuration items (port pins to use, etc). For
2743 an example, see include/configs/sacsng.h.
2747 Enables a hardware SPI driver for general-purpose reads
2748 and writes. As with CONFIG_SOFT_SPI, the board configuration
2749 must define a list of chip-select function pointers.
2750 Currently supported on some MPC8xxx processors. For an
2751 example, see include/configs/mpc8349emds.h.
2755 Enables the driver for the SPI controllers on i.MX and MXC
2756 SoCs. Currently i.MX31/35/51 are supported.
2758 CONFIG_SYS_SPI_MXC_WAIT
2759 Timeout for waiting until spi transfer completed.
2760 default: (CONFIG_SYS_HZ/100) /* 10 ms */
2762 - FPGA Support: CONFIG_FPGA
2764 Enables FPGA subsystem.
2766 CONFIG_FPGA_<vendor>
2768 Enables support for specific chip vendors.
2771 CONFIG_FPGA_<family>
2773 Enables support for FPGA family.
2774 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX)
2778 Specify the number of FPGA devices to support.
2780 CONFIG_CMD_FPGA_LOADMK
2782 Enable support for fpga loadmk command
2784 CONFIG_CMD_FPGA_LOADP
2786 Enable support for fpga loadp command - load partial bitstream
2788 CONFIG_CMD_FPGA_LOADBP
2790 Enable support for fpga loadbp command - load partial bitstream
2793 CONFIG_SYS_FPGA_PROG_FEEDBACK
2795 Enable printing of hash marks during FPGA configuration.
2797 CONFIG_SYS_FPGA_CHECK_BUSY
2799 Enable checks on FPGA configuration interface busy
2800 status by the configuration function. This option
2801 will require a board or device specific function to
2806 If defined, a function that provides delays in the FPGA
2807 configuration driver.
2809 CONFIG_SYS_FPGA_CHECK_CTRLC
2810 Allow Control-C to interrupt FPGA configuration
2812 CONFIG_SYS_FPGA_CHECK_ERROR
2814 Check for configuration errors during FPGA bitfile
2815 loading. For example, abort during Virtex II
2816 configuration if the INIT_B line goes low (which
2817 indicated a CRC error).
2819 CONFIG_SYS_FPGA_WAIT_INIT
2821 Maximum time to wait for the INIT_B line to de-assert
2822 after PROB_B has been de-asserted during a Virtex II
2823 FPGA configuration sequence. The default time is 500
2826 CONFIG_SYS_FPGA_WAIT_BUSY
2828 Maximum time to wait for BUSY to de-assert during
2829 Virtex II FPGA configuration. The default is 5 ms.
2831 CONFIG_SYS_FPGA_WAIT_CONFIG
2833 Time to wait after FPGA configuration. The default is
2836 - Configuration Management:
2839 Some SoCs need special image types (e.g. U-Boot binary
2840 with a special header) as build targets. By defining
2841 CONFIG_BUILD_TARGET in the SoC / board header, this
2842 special image will be automatically built upon calling
2847 If defined, this string will be added to the U-Boot
2848 version information (U_BOOT_VERSION)
2850 - Vendor Parameter Protection:
2852 U-Boot considers the values of the environment
2853 variables "serial#" (Board Serial Number) and
2854 "ethaddr" (Ethernet Address) to be parameters that
2855 are set once by the board vendor / manufacturer, and
2856 protects these variables from casual modification by
2857 the user. Once set, these variables are read-only,
2858 and write or delete attempts are rejected. You can
2859 change this behaviour:
2861 If CONFIG_ENV_OVERWRITE is #defined in your config
2862 file, the write protection for vendor parameters is
2863 completely disabled. Anybody can change or delete
2866 Alternatively, if you define _both_ an ethaddr in the
2867 default env _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
2868 Ethernet address is installed in the environment,
2869 which can be changed exactly ONCE by the user. [The
2870 serial# is unaffected by this, i. e. it remains
2873 The same can be accomplished in a more flexible way
2874 for any variable by configuring the type of access
2875 to allow for those variables in the ".flags" variable
2876 or define CONFIG_ENV_FLAGS_LIST_STATIC.
2881 Define this variable to enable the reservation of
2882 "protected RAM", i. e. RAM which is not overwritten
2883 by U-Boot. Define CONFIG_PRAM to hold the number of
2884 kB you want to reserve for pRAM. You can overwrite
2885 this default value by defining an environment
2886 variable "pram" to the number of kB you want to
2887 reserve. Note that the board info structure will
2888 still show the full amount of RAM. If pRAM is
2889 reserved, a new environment variable "mem" will
2890 automatically be defined to hold the amount of
2891 remaining RAM in a form that can be passed as boot
2892 argument to Linux, for instance like that:
2894 setenv bootargs ... mem=\${mem}
2897 This way you can tell Linux not to use this memory,
2898 either, which results in a memory region that will
2899 not be affected by reboots.
2901 *WARNING* If your board configuration uses automatic
2902 detection of the RAM size, you must make sure that
2903 this memory test is non-destructive. So far, the
2904 following board configurations are known to be
2907 IVMS8, IVML24, SPD8xx, TQM8xxL,
2908 HERMES, IP860, RPXlite, LWMON,
2911 - Access to physical memory region (> 4GB)
2912 Some basic support is provided for operations on memory not
2913 normally accessible to U-Boot - e.g. some architectures
2914 support access to more than 4GB of memory on 32-bit
2915 machines using physical address extension or similar.
2916 Define CONFIG_PHYSMEM to access this basic support, which
2917 currently only supports clearing the memory.
2922 Define this variable to stop the system in case of a
2923 fatal error, so that you have to reset it manually.
2924 This is probably NOT a good idea for an embedded
2925 system where you want the system to reboot
2926 automatically as fast as possible, but it may be
2927 useful during development since you can try to debug
2928 the conditions that lead to the situation.
2930 CONFIG_NET_RETRY_COUNT
2932 This variable defines the number of retries for
2933 network operations like ARP, RARP, TFTP, or BOOTP
2934 before giving up the operation. If not defined, a
2935 default value of 5 is used.
2939 Timeout waiting for an ARP reply in milliseconds.
2943 Timeout in milliseconds used in NFS protocol.
2944 If you encounter "ERROR: Cannot umount" in nfs command,
2945 try longer timeout such as
2946 #define CONFIG_NFS_TIMEOUT 10000UL
2948 - Command Interpreter:
2949 CONFIG_AUTO_COMPLETE
2951 Enable auto completion of commands using TAB.
2953 CONFIG_SYS_PROMPT_HUSH_PS2
2955 This defines the secondary prompt string, which is
2956 printed when the command interpreter needs more input
2957 to complete a command. Usually "> ".
2961 In the current implementation, the local variables
2962 space and global environment variables space are
2963 separated. Local variables are those you define by
2964 simply typing `name=value'. To access a local
2965 variable later on, you have write `$name' or
2966 `${name}'; to execute the contents of a variable
2967 directly type `$name' at the command prompt.
2969 Global environment variables are those you use
2970 setenv/printenv to work with. To run a command stored
2971 in such a variable, you need to use the run command,
2972 and you must not use the '$' sign to access them.
2974 To store commands and special characters in a
2975 variable, please use double quotation marks
2976 surrounding the whole text of the variable, instead
2977 of the backslashes before semicolons and special
2980 - Command Line Editing and History:
2981 CONFIG_CMDLINE_EDITING
2983 Enable editing and History functions for interactive
2984 command line input operations
2986 - Default Environment:
2987 CONFIG_EXTRA_ENV_SETTINGS
2989 Define this to contain any number of null terminated
2990 strings (variable = value pairs) that will be part of
2991 the default environment compiled into the boot image.
2993 For example, place something like this in your
2994 board's config file:
2996 #define CONFIG_EXTRA_ENV_SETTINGS \
3000 Warning: This method is based on knowledge about the
3001 internal format how the environment is stored by the
3002 U-Boot code. This is NOT an official, exported
3003 interface! Although it is unlikely that this format
3004 will change soon, there is no guarantee either.
3005 You better know what you are doing here.
3007 Note: overly (ab)use of the default environment is
3008 discouraged. Make sure to check other ways to preset
3009 the environment like the "source" command or the
3012 CONFIG_ENV_VARS_UBOOT_CONFIG
3014 Define this in order to add variables describing the
3015 U-Boot build configuration to the default environment.
3016 These will be named arch, cpu, board, vendor, and soc.
3018 Enabling this option will cause the following to be defined:
3026 CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG
3028 Define this in order to add variables describing certain
3029 run-time determined information about the hardware to the
3030 environment. These will be named board_name, board_rev.
3032 CONFIG_DELAY_ENVIRONMENT
3034 Normally the environment is loaded when the board is
3035 initialised so that it is available to U-Boot. This inhibits
3036 that so that the environment is not available until
3037 explicitly loaded later by U-Boot code. With CONFIG_OF_CONTROL
3038 this is instead controlled by the value of
3039 /config/load-environment.
3041 - Parallel Flash support:
3044 Traditionally U-boot was run on systems with parallel NOR
3045 flash. This option is used to disable support for parallel NOR
3046 flash. This option should be defined if the board does not have
3049 If this option is not defined one of the generic flash drivers
3050 (e.g. CONFIG_FLASH_CFI_DRIVER or CONFIG_ST_SMI) must be
3051 selected or the board must provide an implementation of the
3052 flash API (see include/flash.h).
3054 - DataFlash Support:
3055 CONFIG_HAS_DATAFLASH
3057 Defining this option enables DataFlash features and
3058 allows to read/write in Dataflash via the standard
3061 - Serial Flash support
3064 Defining this option enables SPI flash commands
3065 'sf probe/read/write/erase/update'.
3067 Usage requires an initial 'probe' to define the serial
3068 flash parameters, followed by read/write/erase/update
3071 The following defaults may be provided by the platform
3072 to handle the common case when only a single serial
3073 flash is present on the system.
3075 CONFIG_SF_DEFAULT_BUS Bus identifier
3076 CONFIG_SF_DEFAULT_CS Chip-select
3077 CONFIG_SF_DEFAULT_MODE (see include/spi.h)
3078 CONFIG_SF_DEFAULT_SPEED in Hz
3082 Define this option to include a destructive SPI flash
3085 CONFIG_SF_DUAL_FLASH Dual flash memories
3087 Define this option to use dual flash support where two flash
3088 memories can be connected with a given cs line.
3089 Currently Xilinx Zynq qspi supports these type of connections.
3091 - SystemACE Support:
3094 Adding this option adds support for Xilinx SystemACE
3095 chips attached via some sort of local bus. The address
3096 of the chip must also be defined in the
3097 CONFIG_SYS_SYSTEMACE_BASE macro. For example:
3099 #define CONFIG_SYSTEMACE
3100 #define CONFIG_SYS_SYSTEMACE_BASE 0xf0000000
3102 When SystemACE support is added, the "ace" device type
3103 becomes available to the fat commands, i.e. fatls.
3105 - TFTP Fixed UDP Port:
3108 If this is defined, the environment variable tftpsrcp
3109 is used to supply the TFTP UDP source port value.
3110 If tftpsrcp isn't defined, the normal pseudo-random port
3111 number generator is used.
3113 Also, the environment variable tftpdstp is used to supply
3114 the TFTP UDP destination port value. If tftpdstp isn't
3115 defined, the normal port 69 is used.
3117 The purpose for tftpsrcp is to allow a TFTP server to
3118 blindly start the TFTP transfer using the pre-configured
3119 target IP address and UDP port. This has the effect of
3120 "punching through" the (Windows XP) firewall, allowing
3121 the remainder of the TFTP transfer to proceed normally.
3122 A better solution is to properly configure the firewall,
3123 but sometimes that is not allowed.
3128 This enables a generic 'hash' command which can produce
3129 hashes / digests from a few algorithms (e.g. SHA1, SHA256).
3133 Enable the hash verify command (hash -v). This adds to code
3136 CONFIG_SHA1 - This option enables support of hashing using SHA1
3137 algorithm. The hash is calculated in software.
3138 CONFIG_SHA256 - This option enables support of hashing using
3139 SHA256 algorithm. The hash is calculated in software.
3140 CONFIG_SHA_HW_ACCEL - This option enables hardware acceleration
3141 for SHA1/SHA256 hashing.
3142 This affects the 'hash' command and also the
3143 hash_lookup_algo() function.
3144 CONFIG_SHA_PROG_HW_ACCEL - This option enables
3145 hardware-acceleration for SHA1/SHA256 progressive hashing.
3146 Data can be streamed in a block at a time and the hashing
3147 is performed in hardware.
3149 Note: There is also a sha1sum command, which should perhaps
3150 be deprecated in favour of 'hash sha1'.
3152 - Freescale i.MX specific commands:
3153 CONFIG_CMD_HDMIDETECT
3154 This enables 'hdmidet' command which returns true if an
3155 HDMI monitor is detected. This command is i.MX 6 specific.
3158 This enables the 'bmode' (bootmode) command for forcing
3159 a boot from specific media.
3161 This is useful for forcing the ROM's usb downloader to
3162 activate upon a watchdog reset which is nice when iterating
3163 on U-Boot. Using the reset button or running bmode normal
3164 will set it back to normal. This command currently
3165 supports i.MX53 and i.MX6.
3170 This enables the RSA algorithm used for FIT image verification
3171 in U-Boot. See doc/uImage.FIT/signature.txt for more information.
3173 The Modular Exponentiation algorithm in RSA is implemented using
3174 driver model. So CONFIG_DM needs to be enabled by default for this
3175 library to function.
3177 The signing part is build into mkimage regardless of this
3178 option. The software based modular exponentiation is built into
3179 mkimage irrespective of this option.
3181 - bootcount support:
3182 CONFIG_BOOTCOUNT_LIMIT
3184 This enables the bootcounter support, see:
3185 http://www.denx.de/wiki/DULG/UBootBootCountLimit
3188 enable special bootcounter support on at91sam9xe based boards.
3190 enable special bootcounter support on blackfin based boards.
3192 enable special bootcounter support on da850 based boards.
3193 CONFIG_BOOTCOUNT_RAM
3194 enable support for the bootcounter in RAM
3195 CONFIG_BOOTCOUNT_I2C
3196 enable support for the bootcounter on an i2c (like RTC) device.
3197 CONFIG_SYS_I2C_RTC_ADDR = i2c chip address
3198 CONFIG_SYS_BOOTCOUNT_ADDR = i2c addr which is used for
3200 CONFIG_BOOTCOUNT_ALEN = address len
3202 - Show boot progress:
3203 CONFIG_SHOW_BOOT_PROGRESS
3205 Defining this option allows to add some board-
3206 specific code (calling a user-provided function
3207 "show_boot_progress(int)") that enables you to show
3208 the system's boot progress on some display (for
3209 example, some LED's) on your board. At the moment,
3210 the following checkpoints are implemented:
3213 Legacy uImage format:
3216 1 common/cmd_bootm.c before attempting to boot an image
3217 -1 common/cmd_bootm.c Image header has bad magic number
3218 2 common/cmd_bootm.c Image header has correct magic number
3219 -2 common/cmd_bootm.c Image header has bad checksum
3220 3 common/cmd_bootm.c Image header has correct checksum
3221 -3 common/cmd_bootm.c Image data has bad checksum
3222 4 common/cmd_bootm.c Image data has correct checksum
3223 -4 common/cmd_bootm.c Image is for unsupported architecture
3224 5 common/cmd_bootm.c Architecture check OK
3225 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi)
3226 6 common/cmd_bootm.c Image Type check OK
3227 -6 common/cmd_bootm.c gunzip uncompression error
3228 -7 common/cmd_bootm.c Unimplemented compression type
3229 7 common/cmd_bootm.c Uncompression OK
3230 8 common/cmd_bootm.c No uncompress/copy overwrite error
3231 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX)
3233 9 common/image.c Start initial ramdisk verification
3234 -10 common/image.c Ramdisk header has bad magic number
3235 -11 common/image.c Ramdisk header has bad checksum
3236 10 common/image.c Ramdisk header is OK
3237 -12 common/image.c Ramdisk data has bad checksum
3238 11 common/image.c Ramdisk data has correct checksum
3239 12 common/image.c Ramdisk verification complete, start loading
3240 -13 common/image.c Wrong Image Type (not PPC Linux ramdisk)
3241 13 common/image.c Start multifile image verification
3242 14 common/image.c No initial ramdisk, no multifile, continue.
3244 15 arch/<arch>/lib/bootm.c All preparation done, transferring control to OS
3246 -30 arch/powerpc/lib/board.c Fatal error, hang the system
3247 -31 post/post.c POST test failed, detected by post_output_backlog()
3248 -32 post/post.c POST test failed, detected by post_run_single()
3250 34 common/cmd_doc.c before loading a Image from a DOC device
3251 -35 common/cmd_doc.c Bad usage of "doc" command
3252 35 common/cmd_doc.c correct usage of "doc" command
3253 -36 common/cmd_doc.c No boot device
3254 36 common/cmd_doc.c correct boot device
3255 -37 common/cmd_doc.c Unknown Chip ID on boot device
3256 37 common/cmd_doc.c correct chip ID found, device available
3257 -38 common/cmd_doc.c Read Error on boot device
3258 38 common/cmd_doc.c reading Image header from DOC device OK
3259 -39 common/cmd_doc.c Image header has bad magic number
3260 39 common/cmd_doc.c Image header has correct magic number
3261 -40 common/cmd_doc.c Error reading Image from DOC device
3262 40 common/cmd_doc.c Image header has correct magic number
3263 41 common/cmd_ide.c before loading a Image from a IDE device
3264 -42 common/cmd_ide.c Bad usage of "ide" command
3265 42 common/cmd_ide.c correct usage of "ide" command
3266 -43 common/cmd_ide.c No boot device
3267 43 common/cmd_ide.c boot device found
3268 -44 common/cmd_ide.c Device not available
3269 44 common/cmd_ide.c Device available
3270 -45 common/cmd_ide.c wrong partition selected
3271 45 common/cmd_ide.c partition selected
3272 -46 common/cmd_ide.c Unknown partition table
3273 46 common/cmd_ide.c valid partition table found
3274 -47 common/cmd_ide.c Invalid partition type
3275 47 common/cmd_ide.c correct partition type
3276 -48 common/cmd_ide.c Error reading Image Header on boot device
3277 48 common/cmd_ide.c reading Image Header from IDE device OK
3278 -49 common/cmd_ide.c Image header has bad magic number
3279 49 common/cmd_ide.c Image header has correct magic number
3280 -50 common/cmd_ide.c Image header has bad checksum
3281 50 common/cmd_ide.c Image header has correct checksum
3282 -51 common/cmd_ide.c Error reading Image from IDE device
3283 51 common/cmd_ide.c reading Image from IDE device OK
3284 52 common/cmd_nand.c before loading a Image from a NAND device
3285 -53 common/cmd_nand.c Bad usage of "nand" command
3286 53 common/cmd_nand.c correct usage of "nand" command
3287 -54 common/cmd_nand.c No boot device
3288 54 common/cmd_nand.c boot device found
3289 -55 common/cmd_nand.c Unknown Chip ID on boot device
3290 55 common/cmd_nand.c correct chip ID found, device available
3291 -56 common/cmd_nand.c Error reading Image Header on boot device
3292 56 common/cmd_nand.c reading Image Header from NAND device OK
3293 -57 common/cmd_nand.c Image header has bad magic number
3294 57 common/cmd_nand.c Image header has correct magic number
3295 -58 common/cmd_nand.c Error reading Image from NAND device
3296 58 common/cmd_nand.c reading Image from NAND device OK
3298 -60 common/env_common.c Environment has a bad CRC, using default
3300 64 net/eth.c starting with Ethernet configuration.
3301 -64 net/eth.c no Ethernet found.
3302 65 net/eth.c Ethernet found.
3304 -80 common/cmd_net.c usage wrong
3305 80 common/cmd_net.c before calling net_loop()
3306 -81 common/cmd_net.c some error in net_loop() occurred
3307 81 common/cmd_net.c net_loop() back without error
3308 -82 common/cmd_net.c size == 0 (File with size 0 loaded)
3309 82 common/cmd_net.c trying automatic boot
3310 83 common/cmd_net.c running "source" command
3311 -83 common/cmd_net.c some error in automatic boot or "source" command
3312 84 common/cmd_net.c end without errors
3317 100 common/cmd_bootm.c Kernel FIT Image has correct format
3318 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format
3319 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration
3320 -101 common/cmd_bootm.c Can't get configuration for kernel subimage
3321 102 common/cmd_bootm.c Kernel unit name specified
3322 -103 common/cmd_bootm.c Can't get kernel subimage node offset
3323 103 common/cmd_bootm.c Found configuration node
3324 104 common/cmd_bootm.c Got kernel subimage node offset
3325 -104 common/cmd_bootm.c Kernel subimage hash verification failed
3326 105 common/cmd_bootm.c Kernel subimage hash verification OK
3327 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture
3328 106 common/cmd_bootm.c Architecture check OK
3329 -106 common/cmd_bootm.c Kernel subimage has wrong type
3330 107 common/cmd_bootm.c Kernel subimage type OK
3331 -107 common/cmd_bootm.c Can't get kernel subimage data/size
3332 108 common/cmd_bootm.c Got kernel subimage data/size
3333 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT)
3334 -109 common/cmd_bootm.c Can't get kernel subimage type
3335 -110 common/cmd_bootm.c Can't get kernel subimage comp
3336 -111 common/cmd_bootm.c Can't get kernel subimage os
3337 -112 common/cmd_bootm.c Can't get kernel subimage load address
3338 -113 common/cmd_bootm.c Image uncompress/copy overwrite error
3340 120 common/image.c Start initial ramdisk verification
3341 -120 common/image.c Ramdisk FIT image has incorrect format
3342 121 common/image.c Ramdisk FIT image has correct format
3343 122 common/image.c No ramdisk subimage unit name, using configuration
3344 -122 common/image.c Can't get configuration for ramdisk subimage
3345 123 common/image.c Ramdisk unit name specified
3346 -124 common/image.c Can't get ramdisk subimage node offset
3347 125 common/image.c Got ramdisk subimage node offset
3348 -125 common/image.c Ramdisk subimage hash verification failed
3349 126 common/image.c Ramdisk subimage hash verification OK
3350 -126 common/image.c Ramdisk subimage for unsupported architecture
3351 127 common/image.c Architecture check OK
3352 -127 common/image.c Can't get ramdisk subimage data/size
3353 128 common/image.c Got ramdisk subimage data/size
3354 129 common/image.c Can't get ramdisk load address
3355 -129 common/image.c Got ramdisk load address
3357 -130 common/cmd_doc.c Incorrect FIT image format
3358 131 common/cmd_doc.c FIT image format OK
3360 -140 common/cmd_ide.c Incorrect FIT image format
3361 141 common/cmd_ide.c FIT image format OK
3363 -150 common/cmd_nand.c Incorrect FIT image format
3364 151 common/cmd_nand.c FIT image format OK
3366 - legacy image format:
3367 CONFIG_IMAGE_FORMAT_LEGACY
3368 enables the legacy image format support in U-Boot.
3371 enabled if CONFIG_FIT_SIGNATURE is not defined.
3373 CONFIG_DISABLE_IMAGE_LEGACY
3374 disable the legacy image format
3376 This define is introduced, as the legacy image format is
3377 enabled per default for backward compatibility.
3379 - FIT image support:
3381 Enable support for the FIT uImage format.
3383 CONFIG_FIT_BEST_MATCH
3384 When no configuration is explicitly selected, default to the
3385 one whose fdt's compatibility field best matches that of
3386 U-Boot itself. A match is considered "best" if it matches the
3387 most specific compatibility entry of U-Boot's fdt's root node.
3388 The order of entries in the configuration's fdt is ignored.
3390 CONFIG_FIT_SIGNATURE
3391 This option enables signature verification of FIT uImages,
3392 using a hash signed and verified using RSA. If
3393 CONFIG_SHA_PROG_HW_ACCEL is defined, i.e support for progressive
3394 hashing is available using hardware, RSA library will use it.
3395 See doc/uImage.FIT/signature.txt for more details.
3397 WARNING: When relying on signed FIT images with required
3398 signature check the legacy image format is default
3399 disabled. If a board need legacy image format support
3400 enable this through CONFIG_IMAGE_FORMAT_LEGACY
3402 CONFIG_FIT_DISABLE_SHA256
3403 Supporting SHA256 hashes has quite an impact on binary size.
3404 For constrained systems sha256 hash support can be disabled
3407 - Standalone program support:
3408 CONFIG_STANDALONE_LOAD_ADDR
3410 This option defines a board specific value for the
3411 address where standalone program gets loaded, thus
3412 overwriting the architecture dependent default
3415 - Frame Buffer Address:
3418 Define CONFIG_FB_ADDR if you want to use specific
3419 address for frame buffer. This is typically the case
3420 when using a graphics controller has separate video
3421 memory. U-Boot will then place the frame buffer at
3422 the given address instead of dynamically reserving it
3423 in system RAM by calling lcd_setmem(), which grabs
3424 the memory for the frame buffer depending on the
3425 configured panel size.
3427 Please see board_init_f function.
3429 - Automatic software updates via TFTP server
3431 CONFIG_UPDATE_TFTP_CNT_MAX
3432 CONFIG_UPDATE_TFTP_MSEC_MAX
3434 These options enable and control the auto-update feature;
3435 for a more detailed description refer to doc/README.update.
3437 - MTD Support (mtdparts command, UBI support)
3440 Adds the MTD device infrastructure from the Linux kernel.
3441 Needed for mtdparts command support.
3443 CONFIG_MTD_PARTITIONS
3445 Adds the MTD partitioning infrastructure from the Linux
3446 kernel. Needed for UBI support.
3451 Adds commands for interacting with MTD partitions formatted
3452 with the UBI flash translation layer
3454 Requires also defining CONFIG_RBTREE
3456 CONFIG_UBI_SILENCE_MSG
3458 Make the verbose messages from UBI stop printing. This leaves
3459 warnings and errors enabled.
3462 CONFIG_MTD_UBI_WL_THRESHOLD
3463 This parameter defines the maximum difference between the highest
3464 erase counter value and the lowest erase counter value of eraseblocks
3465 of UBI devices. When this threshold is exceeded, UBI starts performing
3466 wear leveling by means of moving data from eraseblock with low erase
3467 counter to eraseblocks with high erase counter.
3469 The default value should be OK for SLC NAND flashes, NOR flashes and
3470 other flashes which have eraseblock life-cycle 100000 or more.
3471 However, in case of MLC NAND flashes which typically have eraseblock
3472 life-cycle less than 10000, the threshold should be lessened (e.g.,
3473 to 128 or 256, although it does not have to be power of 2).
3477 CONFIG_MTD_UBI_BEB_LIMIT
3478 This option specifies the maximum bad physical eraseblocks UBI
3479 expects on the MTD device (per 1024 eraseblocks). If the
3480 underlying flash does not admit of bad eraseblocks (e.g. NOR
3481 flash), this value is ignored.
3483 NAND datasheets often specify the minimum and maximum NVM
3484 (Number of Valid Blocks) for the flashes' endurance lifetime.
3485 The maximum expected bad eraseblocks per 1024 eraseblocks
3486 then can be calculated as "1024 * (1 - MinNVB / MaxNVB)",
3487 which gives 20 for most NANDs (MaxNVB is basically the total
3488 count of eraseblocks on the chip).
3490 To put it differently, if this value is 20, UBI will try to
3491 reserve about 1.9% of physical eraseblocks for bad blocks
3492 handling. And that will be 1.9% of eraseblocks on the entire
3493 NAND chip, not just the MTD partition UBI attaches. This means
3494 that if you have, say, a NAND flash chip admits maximum 40 bad
3495 eraseblocks, and it is split on two MTD partitions of the same
3496 size, UBI will reserve 40 eraseblocks when attaching a
3501 CONFIG_MTD_UBI_FASTMAP
3502 Fastmap is a mechanism which allows attaching an UBI device
3503 in nearly constant time. Instead of scanning the whole MTD device it
3504 only has to locate a checkpoint (called fastmap) on the device.
3505 The on-flash fastmap contains all information needed to attach
3506 the device. Using fastmap makes only sense on large devices where
3507 attaching by scanning takes long. UBI will not automatically install
3508 a fastmap on old images, but you can set the UBI parameter
3509 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT to 1 if you want so. Please note
3510 that fastmap-enabled images are still usable with UBI implementations
3511 without fastmap support. On typical flash devices the whole fastmap
3512 fits into one PEB. UBI will reserve PEBs to hold two fastmaps.
3514 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT
3515 Set this parameter to enable fastmap automatically on images
3522 Adds commands for interacting with UBI volumes formatted as
3523 UBIFS. UBIFS is read-only in u-boot.
3525 Requires UBI support as well as CONFIG_LZO
3527 CONFIG_UBIFS_SILENCE_MSG
3529 Make the verbose messages from UBIFS stop printing. This leaves
3530 warnings and errors enabled.
3534 Enable building of SPL globally.
3537 LDSCRIPT for linking the SPL binary.
3539 CONFIG_SPL_MAX_FOOTPRINT
3540 Maximum size in memory allocated to the SPL, BSS included.
3541 When defined, the linker checks that the actual memory
3542 used by SPL from _start to __bss_end does not exceed it.
3543 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
3544 must not be both defined at the same time.
3547 Maximum size of the SPL image (text, data, rodata, and
3548 linker lists sections), BSS excluded.
3549 When defined, the linker checks that the actual size does
3552 CONFIG_SPL_TEXT_BASE
3553 TEXT_BASE for linking the SPL binary.
3555 CONFIG_SPL_RELOC_TEXT_BASE
3556 Address to relocate to. If unspecified, this is equal to
3557 CONFIG_SPL_TEXT_BASE (i.e. no relocation is done).
3559 CONFIG_SPL_BSS_START_ADDR
3560 Link address for the BSS within the SPL binary.
3562 CONFIG_SPL_BSS_MAX_SIZE
3563 Maximum size in memory allocated to the SPL BSS.
3564 When defined, the linker checks that the actual memory used
3565 by SPL from __bss_start to __bss_end does not exceed it.
3566 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
3567 must not be both defined at the same time.
3570 Adress of the start of the stack SPL will use
3572 CONFIG_SPL_PANIC_ON_RAW_IMAGE
3573 When defined, SPL will panic() if the image it has
3574 loaded does not have a signature.
3575 Defining this is useful when code which loads images
3576 in SPL cannot guarantee that absolutely all read errors
3578 An example is the LPC32XX MLC NAND driver, which will
3579 consider that a completely unreadable NAND block is bad,
3580 and thus should be skipped silently.
3582 CONFIG_SPL_RELOC_STACK
3583 Adress of the start of the stack SPL will use after
3584 relocation. If unspecified, this is equal to
3587 CONFIG_SYS_SPL_MALLOC_START
3588 Starting address of the malloc pool used in SPL.
3590 CONFIG_SYS_SPL_MALLOC_SIZE
3591 The size of the malloc pool used in SPL.
3593 CONFIG_SPL_FRAMEWORK
3594 Enable the SPL framework under common/. This framework
3595 supports MMC, NAND and YMODEM loading of U-Boot and NAND
3596 NAND loading of the Linux Kernel.
3599 Enable booting directly to an OS from SPL.
3600 See also: doc/README.falcon
3602 CONFIG_SPL_DISPLAY_PRINT
3603 For ARM, enable an optional function to print more information
3604 about the running system.
3606 CONFIG_SPL_INIT_MINIMAL
3607 Arch init code should be built for a very small image
3609 CONFIG_SPL_LIBCOMMON_SUPPORT
3610 Support for common/libcommon.o in SPL binary
3612 CONFIG_SPL_LIBDISK_SUPPORT
3613 Support for disk/libdisk.o in SPL binary
3615 CONFIG_SPL_I2C_SUPPORT
3616 Support for drivers/i2c/libi2c.o in SPL binary
3618 CONFIG_SPL_GPIO_SUPPORT
3619 Support for drivers/gpio/libgpio.o in SPL binary
3621 CONFIG_SPL_MMC_SUPPORT
3622 Support for drivers/mmc/libmmc.o in SPL binary
3624 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_SECTOR,
3625 CONFIG_SYS_U_BOOT_MAX_SIZE_SECTORS,
3626 Address and partition on the MMC to load U-Boot from
3627 when the MMC is being used in raw mode.
3629 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_PARTITION
3630 Partition on the MMC to load U-Boot from when the MMC is being
3633 CONFIG_SYS_MMCSD_RAW_MODE_KERNEL_SECTOR
3634 Sector to load kernel uImage from when MMC is being
3635 used in raw mode (for Falcon mode)
3637 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTOR,
3638 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTORS
3639 Sector and number of sectors to load kernel argument
3640 parameters from when MMC is being used in raw mode
3643 CONFIG_SYS_MMCSD_FS_BOOT_PARTITION
3644 Partition on the MMC to load U-Boot from when the MMC is being
3647 CONFIG_SPL_FAT_SUPPORT
3648 Support for fs/fat/libfat.o in SPL binary
3650 CONFIG_SPL_EXT_SUPPORT
3651 Support for EXT filesystem in SPL binary
3653 CONFIG_SPL_FS_LOAD_PAYLOAD_NAME
3654 Filename to read to load U-Boot when reading from filesystem
3656 CONFIG_SPL_FS_LOAD_KERNEL_NAME
3657 Filename to read to load kernel uImage when reading
3658 from filesystem (for Falcon mode)
3660 CONFIG_SPL_FS_LOAD_ARGS_NAME
3661 Filename to read to load kernel argument parameters
3662 when reading from filesystem (for Falcon mode)
3664 CONFIG_SPL_MPC83XX_WAIT_FOR_NAND
3665 Set this for NAND SPL on PPC mpc83xx targets, so that
3666 start.S waits for the rest of the SPL to load before
3667 continuing (the hardware starts execution after just
3668 loading the first page rather than the full 4K).
3670 CONFIG_SPL_SKIP_RELOCATE
3671 Avoid SPL relocation
3673 CONFIG_SPL_NAND_BASE
3674 Include nand_base.c in the SPL. Requires
3675 CONFIG_SPL_NAND_DRIVERS.
3677 CONFIG_SPL_NAND_DRIVERS
3678 SPL uses normal NAND drivers, not minimal drivers.
3681 Include standard software ECC in the SPL
3683 CONFIG_SPL_NAND_SIMPLE
3684 Support for NAND boot using simple NAND drivers that
3685 expose the cmd_ctrl() interface.
3687 CONFIG_SPL_MTD_SUPPORT
3688 Support for the MTD subsystem within SPL. Useful for
3689 environment on NAND support within SPL.
3691 CONFIG_SPL_NAND_RAW_ONLY
3692 Support to boot only raw u-boot.bin images. Use this only
3693 if you need to save space.
3695 CONFIG_SPL_MPC8XXX_INIT_DDR_SUPPORT
3696 Set for the SPL on PPC mpc8xxx targets, support for
3697 drivers/ddr/fsl/libddr.o in SPL binary.
3699 CONFIG_SPL_COMMON_INIT_DDR
3700 Set for common ddr init with serial presence detect in
3703 CONFIG_SYS_NAND_5_ADDR_CYCLE, CONFIG_SYS_NAND_PAGE_COUNT,
3704 CONFIG_SYS_NAND_PAGE_SIZE, CONFIG_SYS_NAND_OOBSIZE,
3705 CONFIG_SYS_NAND_BLOCK_SIZE, CONFIG_SYS_NAND_BAD_BLOCK_POS,
3706 CONFIG_SYS_NAND_ECCPOS, CONFIG_SYS_NAND_ECCSIZE,
3707 CONFIG_SYS_NAND_ECCBYTES
3708 Defines the size and behavior of the NAND that SPL uses
3711 CONFIG_SPL_NAND_BOOT
3712 Add support NAND boot
3714 CONFIG_SYS_NAND_U_BOOT_OFFS
3715 Location in NAND to read U-Boot from
3717 CONFIG_SYS_NAND_U_BOOT_DST
3718 Location in memory to load U-Boot to
3720 CONFIG_SYS_NAND_U_BOOT_SIZE
3721 Size of image to load
3723 CONFIG_SYS_NAND_U_BOOT_START
3724 Entry point in loaded image to jump to
3726 CONFIG_SYS_NAND_HW_ECC_OOBFIRST
3727 Define this if you need to first read the OOB and then the
3728 data. This is used, for example, on davinci platforms.
3730 CONFIG_SPL_OMAP3_ID_NAND
3731 Support for an OMAP3-specific set of functions to return the
3732 ID and MFR of the first attached NAND chip, if present.
3734 CONFIG_SPL_SERIAL_SUPPORT
3735 Support for drivers/serial/libserial.o in SPL binary
3737 CONFIG_SPL_SPI_FLASH_SUPPORT
3738 Support for drivers/mtd/spi/libspi_flash.o in SPL binary
3740 CONFIG_SPL_SPI_SUPPORT
3741 Support for drivers/spi/libspi.o in SPL binary
3743 CONFIG_SPL_RAM_DEVICE
3744 Support for running image already present in ram, in SPL binary
3746 CONFIG_SPL_LIBGENERIC_SUPPORT
3747 Support for lib/libgeneric.o in SPL binary
3749 CONFIG_SPL_ENV_SUPPORT
3750 Support for the environment operating in SPL binary
3752 CONFIG_SPL_NET_SUPPORT
3753 Support for the net/libnet.o in SPL binary.
3754 It conflicts with SPL env from storage medium specified by
3755 CONFIG_ENV_IS_xxx but CONFIG_ENV_IS_NOWHERE
3758 Image offset to which the SPL should be padded before appending
3759 the SPL payload. By default, this is defined as
3760 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3761 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3762 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3765 Final target image containing SPL and payload. Some SPLs
3766 use an arch-specific makefile fragment instead, for
3767 example if more than one image needs to be produced.
3769 CONFIG_FIT_SPL_PRINT
3770 Printing information about a FIT image adds quite a bit of
3771 code to SPL. So this is normally disabled in SPL. Use this
3772 option to re-enable it. This will affect the output of the
3773 bootm command when booting a FIT image.
3777 Enable building of TPL globally.
3780 Image offset to which the TPL should be padded before appending
3781 the TPL payload. By default, this is defined as
3782 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3783 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3784 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3789 [so far only for SMDK2400 boards]
3791 - Modem support enable:
3792 CONFIG_MODEM_SUPPORT
3794 - RTS/CTS Flow control enable:
3797 - Modem debug support:
3798 CONFIG_MODEM_SUPPORT_DEBUG
3800 Enables debugging stuff (char screen[1024], dbg())
3801 for modem support. Useful only with BDI2000.
3803 - Interrupt support (PPC):
3805 There are common interrupt_init() and timer_interrupt()
3806 for all PPC archs. interrupt_init() calls interrupt_init_cpu()
3807 for CPU specific initialization. interrupt_init_cpu()
3808 should set decrementer_count to appropriate value. If
3809 CPU resets decrementer automatically after interrupt
3810 (ppc4xx) it should set decrementer_count to zero.
3811 timer_interrupt() calls timer_interrupt_cpu() for CPU
3812 specific handling. If board has watchdog / status_led
3813 / other_activity_monitor it works automatically from
3814 general timer_interrupt().
3818 In the target system modem support is enabled when a
3819 specific key (key combination) is pressed during
3820 power-on. Otherwise U-Boot will boot normally
3821 (autoboot). The key_pressed() function is called from
3822 board_init(). Currently key_pressed() is a dummy
3823 function, returning 1 and thus enabling modem
3826 If there are no modem init strings in the
3827 environment, U-Boot proceed to autoboot; the
3828 previous output (banner, info printfs) will be
3831 See also: doc/README.Modem
3833 Board initialization settings:
3834 ------------------------------
3836 During Initialization u-boot calls a number of board specific functions
3837 to allow the preparation of board specific prerequisites, e.g. pin setup
3838 before drivers are initialized. To enable these callbacks the
3839 following configuration macros have to be defined. Currently this is
3840 architecture specific, so please check arch/your_architecture/lib/board.c
3841 typically in board_init_f() and board_init_r().
3843 - CONFIG_BOARD_EARLY_INIT_F: Call board_early_init_f()
3844 - CONFIG_BOARD_EARLY_INIT_R: Call board_early_init_r()
3845 - CONFIG_BOARD_LATE_INIT: Call board_late_init()
3846 - CONFIG_BOARD_POSTCLK_INIT: Call board_postclk_init()
3848 Configuration Settings:
3849 -----------------------
3851 - CONFIG_SYS_SUPPORT_64BIT_DATA: Defined automatically if compiled as 64-bit.
3852 Optionally it can be defined to support 64-bit memory commands.
3854 - CONFIG_SYS_LONGHELP: Defined when you want long help messages included;
3855 undefine this when you're short of memory.
3857 - CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default
3858 width of the commands listed in the 'help' command output.
3860 - CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to
3861 prompt for user input.
3863 - CONFIG_SYS_CBSIZE: Buffer size for input from the Console
3865 - CONFIG_SYS_PBSIZE: Buffer size for Console output
3867 - CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands
3869 - CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to
3870 the application (usually a Linux kernel) when it is
3873 - CONFIG_SYS_BAUDRATE_TABLE:
3874 List of legal baudrate settings for this board.
3876 - CONFIG_SYS_CONSOLE_INFO_QUIET
3877 Suppress display of console information at boot.
3879 - CONFIG_SYS_CONSOLE_IS_IN_ENV
3880 If the board specific function
3881 extern int overwrite_console (void);
3882 returns 1, the stdin, stderr and stdout are switched to the
3883 serial port, else the settings in the environment are used.
3885 - CONFIG_SYS_CONSOLE_OVERWRITE_ROUTINE
3886 Enable the call to overwrite_console().
3888 - CONFIG_SYS_CONSOLE_ENV_OVERWRITE
3889 Enable overwrite of previous console environment settings.
3891 - CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END:
3892 Begin and End addresses of the area used by the
3895 - CONFIG_SYS_ALT_MEMTEST:
3896 Enable an alternate, more extensive memory test.
3898 - CONFIG_SYS_MEMTEST_SCRATCH:
3899 Scratch address used by the alternate memory test
3900 You only need to set this if address zero isn't writeable
3902 - CONFIG_SYS_MEM_TOP_HIDE (PPC only):
3903 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header,
3904 this specified memory area will get subtracted from the top
3905 (end) of RAM and won't get "touched" at all by U-Boot. By
3906 fixing up gd->ram_size the Linux kernel should gets passed
3907 the now "corrected" memory size and won't touch it either.
3908 This should work for arch/ppc and arch/powerpc. Only Linux
3909 board ports in arch/powerpc with bootwrapper support that
3910 recalculate the memory size from the SDRAM controller setup
3911 will have to get fixed in Linux additionally.
3913 This option can be used as a workaround for the 440EPx/GRx
3914 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't
3917 WARNING: Please make sure that this value is a multiple of
3918 the Linux page size (normally 4k). If this is not the case,
3919 then the end address of the Linux memory will be located at a
3920 non page size aligned address and this could cause major
3923 - CONFIG_SYS_LOADS_BAUD_CHANGE:
3924 Enable temporary baudrate change while serial download
3926 - CONFIG_SYS_SDRAM_BASE:
3927 Physical start address of SDRAM. _Must_ be 0 here.
3929 - CONFIG_SYS_MBIO_BASE:
3930 Physical start address of Motherboard I/O (if using a
3933 - CONFIG_SYS_FLASH_BASE:
3934 Physical start address of Flash memory.
3936 - CONFIG_SYS_MONITOR_BASE:
3937 Physical start address of boot monitor code (set by
3938 make config files to be same as the text base address
3939 (CONFIG_SYS_TEXT_BASE) used when linking) - same as
3940 CONFIG_SYS_FLASH_BASE when booting from flash.
3942 - CONFIG_SYS_MONITOR_LEN:
3943 Size of memory reserved for monitor code, used to
3944 determine _at_compile_time_ (!) if the environment is
3945 embedded within the U-Boot image, or in a separate
3948 - CONFIG_SYS_MALLOC_LEN:
3949 Size of DRAM reserved for malloc() use.
3951 - CONFIG_SYS_MALLOC_F_LEN
3952 Size of the malloc() pool for use before relocation. If
3953 this is defined, then a very simple malloc() implementation
3954 will become available before relocation. The address is just
3955 below the global data, and the stack is moved down to make
3958 This feature allocates regions with increasing addresses
3959 within the region. calloc() is supported, but realloc()
3960 is not available. free() is supported but does nothing.
3961 The memory will be freed (or in fact just forgotten) when
3962 U-Boot relocates itself.
3964 Pre-relocation malloc() is only supported on ARM and sandbox
3965 at present but is fairly easy to enable for other archs.
3967 - CONFIG_SYS_MALLOC_SIMPLE
3968 Provides a simple and small malloc() and calloc() for those
3969 boards which do not use the full malloc in SPL (which is
3970 enabled with CONFIG_SYS_SPL_MALLOC_START).
3972 - CONFIG_SYS_NONCACHED_MEMORY:
3973 Size of non-cached memory area. This area of memory will be
3974 typically located right below the malloc() area and mapped
3975 uncached in the MMU. This is useful for drivers that would
3976 otherwise require a lot of explicit cache maintenance. For
3977 some drivers it's also impossible to properly maintain the
3978 cache. For example if the regions that need to be flushed
3979 are not a multiple of the cache-line size, *and* padding
3980 cannot be allocated between the regions to align them (i.e.
3981 if the HW requires a contiguous array of regions, and the
3982 size of each region is not cache-aligned), then a flush of
3983 one region may result in overwriting data that hardware has
3984 written to another region in the same cache-line. This can
3985 happen for example in network drivers where descriptors for
3986 buffers are typically smaller than the CPU cache-line (e.g.
3987 16 bytes vs. 32 or 64 bytes).
3989 Non-cached memory is only supported on 32-bit ARM at present.
3991 - CONFIG_SYS_BOOTM_LEN:
3992 Normally compressed uImages are limited to an
3993 uncompressed size of 8 MBytes. If this is not enough,
3994 you can define CONFIG_SYS_BOOTM_LEN in your board config file
3995 to adjust this setting to your needs.
3997 - CONFIG_SYS_BOOTMAPSZ:
3998 Maximum size of memory mapped by the startup code of
3999 the Linux kernel; all data that must be processed by
4000 the Linux kernel (bd_info, boot arguments, FDT blob if
4001 used) must be put below this limit, unless "bootm_low"
4002 environment variable is defined and non-zero. In such case
4003 all data for the Linux kernel must be between "bootm_low"
4004 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ. The environment
4005 variable "bootm_mapsize" will override the value of
4006 CONFIG_SYS_BOOTMAPSZ. If CONFIG_SYS_BOOTMAPSZ is undefined,
4007 then the value in "bootm_size" will be used instead.
4009 - CONFIG_SYS_BOOT_RAMDISK_HIGH:
4010 Enable initrd_high functionality. If defined then the
4011 initrd_high feature is enabled and the bootm ramdisk subcommand
4014 - CONFIG_SYS_BOOT_GET_CMDLINE:
4015 Enables allocating and saving kernel cmdline in space between
4016 "bootm_low" and "bootm_low" + BOOTMAPSZ.
4018 - CONFIG_SYS_BOOT_GET_KBD:
4019 Enables allocating and saving a kernel copy of the bd_info in
4020 space between "bootm_low" and "bootm_low" + BOOTMAPSZ.
4022 - CONFIG_SYS_MAX_FLASH_BANKS:
4023 Max number of Flash memory banks
4025 - CONFIG_SYS_MAX_FLASH_SECT:
4026 Max number of sectors on a Flash chip
4028 - CONFIG_SYS_FLASH_ERASE_TOUT:
4029 Timeout for Flash erase operations (in ms)
4031 - CONFIG_SYS_FLASH_WRITE_TOUT:
4032 Timeout for Flash write operations (in ms)
4034 - CONFIG_SYS_FLASH_LOCK_TOUT
4035 Timeout for Flash set sector lock bit operation (in ms)
4037 - CONFIG_SYS_FLASH_UNLOCK_TOUT
4038 Timeout for Flash clear lock bits operation (in ms)
4040 - CONFIG_SYS_FLASH_PROTECTION
4041 If defined, hardware flash sectors protection is used
4042 instead of U-Boot software protection.
4044 - CONFIG_SYS_DIRECT_FLASH_TFTP:
4046 Enable TFTP transfers directly to flash memory;
4047 without this option such a download has to be
4048 performed in two steps: (1) download to RAM, and (2)
4049 copy from RAM to flash.
4051 The two-step approach is usually more reliable, since
4052 you can check if the download worked before you erase
4053 the flash, but in some situations (when system RAM is
4054 too limited to allow for a temporary copy of the
4055 downloaded image) this option may be very useful.
4057 - CONFIG_SYS_FLASH_CFI:
4058 Define if the flash driver uses extra elements in the
4059 common flash structure for storing flash geometry.
4061 - CONFIG_FLASH_CFI_DRIVER
4062 This option also enables the building of the cfi_flash driver
4063 in the drivers directory
4065 - CONFIG_FLASH_CFI_MTD
4066 This option enables the building of the cfi_mtd driver
4067 in the drivers directory. The driver exports CFI flash
4070 - CONFIG_SYS_FLASH_USE_BUFFER_WRITE
4071 Use buffered writes to flash.
4073 - CONFIG_FLASH_SPANSION_S29WS_N
4074 s29ws-n MirrorBit flash has non-standard addresses for buffered
4077 - CONFIG_SYS_FLASH_QUIET_TEST
4078 If this option is defined, the common CFI flash doesn't
4079 print it's warning upon not recognized FLASH banks. This
4080 is useful, if some of the configured banks are only
4081 optionally available.
4083 - CONFIG_FLASH_SHOW_PROGRESS
4084 If defined (must be an integer), print out countdown
4085 digits and dots. Recommended value: 45 (9..1) for 80
4086 column displays, 15 (3..1) for 40 column displays.
4088 - CONFIG_FLASH_VERIFY
4089 If defined, the content of the flash (destination) is compared
4090 against the source after the write operation. An error message
4091 will be printed when the contents are not identical.
4092 Please note that this option is useless in nearly all cases,
4093 since such flash programming errors usually are detected earlier
4094 while unprotecting/erasing/programming. Please only enable
4095 this option if you really know what you are doing.
4097 - CONFIG_SYS_RX_ETH_BUFFER:
4098 Defines the number of Ethernet receive buffers. On some
4099 Ethernet controllers it is recommended to set this value
4100 to 8 or even higher (EEPRO100 or 405 EMAC), since all
4101 buffers can be full shortly after enabling the interface
4102 on high Ethernet traffic.
4103 Defaults to 4 if not defined.
4105 - CONFIG_ENV_MAX_ENTRIES
4107 Maximum number of entries in the hash table that is used
4108 internally to store the environment settings. The default
4109 setting is supposed to be generous and should work in most
4110 cases. This setting can be used to tune behaviour; see
4111 lib/hashtable.c for details.
4113 - CONFIG_ENV_FLAGS_LIST_DEFAULT
4114 - CONFIG_ENV_FLAGS_LIST_STATIC
4115 Enable validation of the values given to environment variables when
4116 calling env set. Variables can be restricted to only decimal,
4117 hexadecimal, or boolean. If CONFIG_CMD_NET is also defined,
4118 the variables can also be restricted to IP address or MAC address.
4120 The format of the list is:
4121 type_attribute = [s|d|x|b|i|m]
4122 access_attribute = [a|r|o|c]
4123 attributes = type_attribute[access_attribute]
4124 entry = variable_name[:attributes]
4127 The type attributes are:
4128 s - String (default)
4131 b - Boolean ([1yYtT|0nNfF])
4135 The access attributes are:
4141 - CONFIG_ENV_FLAGS_LIST_DEFAULT
4142 Define this to a list (string) to define the ".flags"
4143 environment variable in the default or embedded environment.
4145 - CONFIG_ENV_FLAGS_LIST_STATIC
4146 Define this to a list (string) to define validation that
4147 should be done if an entry is not found in the ".flags"
4148 environment variable. To override a setting in the static
4149 list, simply add an entry for the same variable name to the
4152 If CONFIG_REGEX is defined, the variable_name above is evaluated as a
4153 regular expression. This allows multiple variables to define the same
4154 flags without explicitly listing them for each variable.
4156 - CONFIG_ENV_ACCESS_IGNORE_FORCE
4157 If defined, don't allow the -f switch to env set override variable
4160 - CONFIG_SYS_GENERIC_BOARD
4161 This selects the architecture-generic board system instead of the
4162 architecture-specific board files. It is intended to move boards
4163 to this new framework over time. Defining this will disable the
4164 arch/foo/lib/board.c file and use common/board_f.c and
4165 common/board_r.c instead. To use this option your architecture
4166 must support it (i.e. must select HAVE_GENERIC_BOARD in arch/Kconfig).
4167 If you find problems enabling this option on your board please report
4168 the problem and send patches!
4170 - CONFIG_OMAP_PLATFORM_RESET_TIME_MAX_USEC (OMAP only)
4171 This is set by OMAP boards for the max time that reset should
4172 be asserted. See doc/README.omap-reset-time for details on how
4173 the value can be calculated on a given board.
4176 If stdint.h is available with your toolchain you can define this
4177 option to enable it. You can provide option 'USE_STDINT=1' when
4178 building U-Boot to enable this.
4180 The following definitions that deal with the placement and management
4181 of environment data (variable area); in general, we support the
4182 following configurations:
4184 - CONFIG_BUILD_ENVCRC:
4186 Builds up envcrc with the target environment so that external utils
4187 may easily extract it and embed it in final U-Boot images.
4189 - CONFIG_ENV_IS_IN_FLASH:
4191 Define this if the environment is in flash memory.
4193 a) The environment occupies one whole flash sector, which is
4194 "embedded" in the text segment with the U-Boot code. This
4195 happens usually with "bottom boot sector" or "top boot
4196 sector" type flash chips, which have several smaller
4197 sectors at the start or the end. For instance, such a
4198 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In
4199 such a case you would place the environment in one of the
4200 4 kB sectors - with U-Boot code before and after it. With
4201 "top boot sector" type flash chips, you would put the
4202 environment in one of the last sectors, leaving a gap
4203 between U-Boot and the environment.
4205 - CONFIG_ENV_OFFSET:
4207 Offset of environment data (variable area) to the
4208 beginning of flash memory; for instance, with bottom boot
4209 type flash chips the second sector can be used: the offset
4210 for this sector is given here.
4212 CONFIG_ENV_OFFSET is used relative to CONFIG_SYS_FLASH_BASE.
4216 This is just another way to specify the start address of
4217 the flash sector containing the environment (instead of
4220 - CONFIG_ENV_SECT_SIZE:
4222 Size of the sector containing the environment.
4225 b) Sometimes flash chips have few, equal sized, BIG sectors.
4226 In such a case you don't want to spend a whole sector for
4231 If you use this in combination with CONFIG_ENV_IS_IN_FLASH
4232 and CONFIG_ENV_SECT_SIZE, you can specify to use only a part
4233 of this flash sector for the environment. This saves
4234 memory for the RAM copy of the environment.
4236 It may also save flash memory if you decide to use this
4237 when your environment is "embedded" within U-Boot code,
4238 since then the remainder of the flash sector could be used
4239 for U-Boot code. It should be pointed out that this is
4240 STRONGLY DISCOURAGED from a robustness point of view:
4241 updating the environment in flash makes it always
4242 necessary to erase the WHOLE sector. If something goes
4243 wrong before the contents has been restored from a copy in
4244 RAM, your target system will be dead.
4246 - CONFIG_ENV_ADDR_REDUND
4247 CONFIG_ENV_SIZE_REDUND
4249 These settings describe a second storage area used to hold
4250 a redundant copy of the environment data, so that there is
4251 a valid backup copy in case there is a power failure during
4252 a "saveenv" operation.
4254 BE CAREFUL! Any changes to the flash layout, and some changes to the
4255 source code will make it necessary to adapt <board>/u-boot.lds*
4259 - CONFIG_ENV_IS_IN_NVRAM:
4261 Define this if you have some non-volatile memory device
4262 (NVRAM, battery buffered SRAM) which you want to use for the
4268 These two #defines are used to determine the memory area you
4269 want to use for environment. It is assumed that this memory
4270 can just be read and written to, without any special
4273 BE CAREFUL! The first access to the environment happens quite early
4274 in U-Boot initialization (when we try to get the setting of for the
4275 console baudrate). You *MUST* have mapped your NVRAM area then, or
4278 Please note that even with NVRAM we still use a copy of the
4279 environment in RAM: we could work on NVRAM directly, but we want to
4280 keep settings there always unmodified except somebody uses "saveenv"
4281 to save the current settings.
4284 - CONFIG_ENV_IS_IN_EEPROM:
4286 Use this if you have an EEPROM or similar serial access
4287 device and a driver for it.
4289 - CONFIG_ENV_OFFSET:
4292 These two #defines specify the offset and size of the
4293 environment area within the total memory of your EEPROM.
4295 - CONFIG_SYS_I2C_EEPROM_ADDR:
4296 If defined, specified the chip address of the EEPROM device.
4297 The default address is zero.
4299 - CONFIG_SYS_I2C_EEPROM_BUS:
4300 If defined, specified the i2c bus of the EEPROM device.
4302 - CONFIG_SYS_EEPROM_PAGE_WRITE_BITS:
4303 If defined, the number of bits used to address bytes in a
4304 single page in the EEPROM device. A 64 byte page, for example
4305 would require six bits.
4307 - CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS:
4308 If defined, the number of milliseconds to delay between
4309 page writes. The default is zero milliseconds.
4311 - CONFIG_SYS_I2C_EEPROM_ADDR_LEN:
4312 The length in bytes of the EEPROM memory array address. Note
4313 that this is NOT the chip address length!
4315 - CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW:
4316 EEPROM chips that implement "address overflow" are ones
4317 like Catalyst 24WC04/08/16 which has 9/10/11 bits of
4318 address and the extra bits end up in the "chip address" bit
4319 slots. This makes a 24WC08 (1Kbyte) chip look like four 256
4322 Note that we consider the length of the address field to
4323 still be one byte because the extra address bits are hidden
4324 in the chip address.
4326 - CONFIG_SYS_EEPROM_SIZE:
4327 The size in bytes of the EEPROM device.
4329 - CONFIG_ENV_EEPROM_IS_ON_I2C
4330 define this, if you have I2C and SPI activated, and your
4331 EEPROM, which holds the environment, is on the I2C bus.
4333 - CONFIG_I2C_ENV_EEPROM_BUS
4334 if you have an Environment on an EEPROM reached over
4335 I2C muxes, you can define here, how to reach this
4336 EEPROM. For example:
4338 #define CONFIG_I2C_ENV_EEPROM_BUS 1
4340 EEPROM which holds the environment, is reached over
4341 a pca9547 i2c mux with address 0x70, channel 3.
4343 - CONFIG_ENV_IS_IN_DATAFLASH:
4345 Define this if you have a DataFlash memory device which you
4346 want to use for the environment.
4348 - CONFIG_ENV_OFFSET:
4352 These three #defines specify the offset and size of the
4353 environment area within the total memory of your DataFlash placed
4354 at the specified address.
4356 - CONFIG_ENV_IS_IN_SPI_FLASH:
4358 Define this if you have a SPI Flash memory device which you
4359 want to use for the environment.
4361 - CONFIG_ENV_OFFSET:
4364 These two #defines specify the offset and size of the
4365 environment area within the SPI Flash. CONFIG_ENV_OFFSET must be
4366 aligned to an erase sector boundary.
4368 - CONFIG_ENV_SECT_SIZE:
4370 Define the SPI flash's sector size.
4372 - CONFIG_ENV_OFFSET_REDUND (optional):
4374 This setting describes a second storage area of CONFIG_ENV_SIZE
4375 size used to hold a redundant copy of the environment data, so
4376 that there is a valid backup copy in case there is a power failure
4377 during a "saveenv" operation. CONFIG_ENV_OFFSET_RENDUND must be
4378 aligned to an erase sector boundary.
4380 - CONFIG_ENV_SPI_BUS (optional):
4381 - CONFIG_ENV_SPI_CS (optional):
4383 Define the SPI bus and chip select. If not defined they will be 0.
4385 - CONFIG_ENV_SPI_MAX_HZ (optional):
4387 Define the SPI max work clock. If not defined then use 1MHz.
4389 - CONFIG_ENV_SPI_MODE (optional):
4391 Define the SPI work mode. If not defined then use SPI_MODE_3.
4393 - CONFIG_ENV_IS_IN_REMOTE:
4395 Define this if you have a remote memory space which you
4396 want to use for the local device's environment.
4401 These two #defines specify the address and size of the
4402 environment area within the remote memory space. The
4403 local device can get the environment from remote memory
4404 space by SRIO or PCIE links.
4406 BE CAREFUL! For some special cases, the local device can not use
4407 "saveenv" command. For example, the local device will get the
4408 environment stored in a remote NOR flash by SRIO or PCIE link,
4409 but it can not erase, write this NOR flash by SRIO or PCIE interface.
4411 - CONFIG_ENV_IS_IN_NAND:
4413 Define this if you have a NAND device which you want to use
4414 for the environment.
4416 - CONFIG_ENV_OFFSET:
4419 These two #defines specify the offset and size of the environment
4420 area within the first NAND device. CONFIG_ENV_OFFSET must be
4421 aligned to an erase block boundary.
4423 - CONFIG_ENV_OFFSET_REDUND (optional):
4425 This setting describes a second storage area of CONFIG_ENV_SIZE
4426 size used to hold a redundant copy of the environment data, so
4427 that there is a valid backup copy in case there is a power failure
4428 during a "saveenv" operation. CONFIG_ENV_OFFSET_RENDUND must be
4429 aligned to an erase block boundary.
4431 - CONFIG_ENV_RANGE (optional):
4433 Specifies the length of the region in which the environment
4434 can be written. This should be a multiple of the NAND device's
4435 block size. Specifying a range with more erase blocks than
4436 are needed to hold CONFIG_ENV_SIZE allows bad blocks within
4437 the range to be avoided.
4439 - CONFIG_ENV_OFFSET_OOB (optional):
4441 Enables support for dynamically retrieving the offset of the
4442 environment from block zero's out-of-band data. The
4443 "nand env.oob" command can be used to record this offset.
4444 Currently, CONFIG_ENV_OFFSET_REDUND is not supported when
4445 using CONFIG_ENV_OFFSET_OOB.
4447 - CONFIG_NAND_ENV_DST
4449 Defines address in RAM to which the nand_spl code should copy the
4450 environment. If redundant environment is used, it will be copied to
4451 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE.
4453 - CONFIG_ENV_IS_IN_UBI:
4455 Define this if you have an UBI volume that you want to use for the
4456 environment. This has the benefit of wear-leveling the environment
4457 accesses, which is important on NAND.
4459 - CONFIG_ENV_UBI_PART:
4461 Define this to a string that is the mtd partition containing the UBI.
4463 - CONFIG_ENV_UBI_VOLUME:
4465 Define this to the name of the volume that you want to store the
4468 - CONFIG_ENV_UBI_VOLUME_REDUND:
4470 Define this to the name of another volume to store a second copy of
4471 the environment in. This will enable redundant environments in UBI.
4472 It is assumed that both volumes are in the same MTD partition.
4474 - CONFIG_UBI_SILENCE_MSG
4475 - CONFIG_UBIFS_SILENCE_MSG
4477 You will probably want to define these to avoid a really noisy system
4478 when storing the env in UBI.
4480 - CONFIG_ENV_IS_IN_FAT:
4481 Define this if you want to use the FAT file system for the environment.
4483 - FAT_ENV_INTERFACE:
4485 Define this to a string that is the name of the block device.
4487 - FAT_ENV_DEV_AND_PART:
4489 Define this to a string to specify the partition of the device. It can
4492 "D:P", "D:0", "D", "D:" or "D:auto" (D, P are integers. And P >= 1)
4493 - "D:P": device D partition P. Error occurs if device D has no
4496 - "D" or "D:": device D partition 1 if device D has partition
4497 table, or the whole device D if has no partition
4499 - "D:auto": first partition in device D with bootable flag set.
4500 If none, first valid partition in device D. If no
4501 partition table then means device D.
4505 It's a string of the FAT file name. This file use to store the
4509 This should be defined. Otherwise it cannot save the environment file.
4511 - CONFIG_ENV_IS_IN_MMC:
4513 Define this if you have an MMC device which you want to use for the
4516 - CONFIG_SYS_MMC_ENV_DEV:
4518 Specifies which MMC device the environment is stored in.
4520 - CONFIG_SYS_MMC_ENV_PART (optional):
4522 Specifies which MMC partition the environment is stored in. If not
4523 set, defaults to partition 0, the user area. Common values might be
4524 1 (first MMC boot partition), 2 (second MMC boot partition).
4526 - CONFIG_ENV_OFFSET:
4529 These two #defines specify the offset and size of the environment
4530 area within the specified MMC device.
4532 If offset is positive (the usual case), it is treated as relative to
4533 the start of the MMC partition. If offset is negative, it is treated
4534 as relative to the end of the MMC partition. This can be useful if
4535 your board may be fitted with different MMC devices, which have
4536 different sizes for the MMC partitions, and you always want the
4537 environment placed at the very end of the partition, to leave the
4538 maximum possible space before it, to store other data.
4540 These two values are in units of bytes, but must be aligned to an
4541 MMC sector boundary.
4543 - CONFIG_ENV_OFFSET_REDUND (optional):
4545 Specifies a second storage area, of CONFIG_ENV_SIZE size, used to
4546 hold a redundant copy of the environment data. This provides a
4547 valid backup copy in case the other copy is corrupted, e.g. due
4548 to a power failure during a "saveenv" operation.
4550 This value may also be positive or negative; this is handled in the
4551 same way as CONFIG_ENV_OFFSET.
4553 This value is also in units of bytes, but must also be aligned to
4554 an MMC sector boundary.
4556 - CONFIG_ENV_SIZE_REDUND (optional):
4558 This value need not be set, even when CONFIG_ENV_OFFSET_REDUND is
4559 set. If this value is set, it must be set to the same value as
4562 - CONFIG_SYS_SPI_INIT_OFFSET
4564 Defines offset to the initial SPI buffer area in DPRAM. The
4565 area is used at an early stage (ROM part) if the environment
4566 is configured to reside in the SPI EEPROM: We need a 520 byte
4567 scratch DPRAM area. It is used between the two initialization
4568 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems
4569 to be a good choice since it makes it far enough from the
4570 start of the data area as well as from the stack pointer.
4572 Please note that the environment is read-only until the monitor
4573 has been relocated to RAM and a RAM copy of the environment has been
4574 created; also, when using EEPROM you will have to use getenv_f()
4575 until then to read environment variables.
4577 The environment is protected by a CRC32 checksum. Before the monitor
4578 is relocated into RAM, as a result of a bad CRC you will be working
4579 with the compiled-in default environment - *silently*!!! [This is
4580 necessary, because the first environment variable we need is the
4581 "baudrate" setting for the console - if we have a bad CRC, we don't
4582 have any device yet where we could complain.]
4584 Note: once the monitor has been relocated, then it will complain if
4585 the default environment is used; a new CRC is computed as soon as you
4586 use the "saveenv" command to store a valid environment.
4588 - CONFIG_SYS_FAULT_ECHO_LINK_DOWN:
4589 Echo the inverted Ethernet link state to the fault LED.
4591 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR
4592 also needs to be defined.
4594 - CONFIG_SYS_FAULT_MII_ADDR:
4595 MII address of the PHY to check for the Ethernet link state.
4597 - CONFIG_NS16550_MIN_FUNCTIONS:
4598 Define this if you desire to only have use of the NS16550_init
4599 and NS16550_putc functions for the serial driver located at
4600 drivers/serial/ns16550.c. This option is useful for saving
4601 space for already greatly restricted images, including but not
4602 limited to NAND_SPL configurations.
4604 - CONFIG_DISPLAY_BOARDINFO
4605 Display information about the board that U-Boot is running on
4606 when U-Boot starts up. The board function checkboard() is called
4609 - CONFIG_DISPLAY_BOARDINFO_LATE
4610 Similar to the previous option, but display this information
4611 later, once stdio is running and output goes to the LCD, if
4614 - CONFIG_BOARD_SIZE_LIMIT:
4615 Maximum size of the U-Boot image. When defined, the
4616 build system checks that the actual size does not
4619 Low Level (hardware related) configuration options:
4620 ---------------------------------------------------
4622 - CONFIG_SYS_CACHELINE_SIZE:
4623 Cache Line Size of the CPU.
4625 - CONFIG_SYS_DEFAULT_IMMR:
4626 Default address of the IMMR after system reset.
4628 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU,
4629 and RPXsuper) to be able to adjust the position of
4630 the IMMR register after a reset.
4632 - CONFIG_SYS_CCSRBAR_DEFAULT:
4633 Default (power-on reset) physical address of CCSR on Freescale
4636 - CONFIG_SYS_CCSRBAR:
4637 Virtual address of CCSR. On a 32-bit build, this is typically
4638 the same value as CONFIG_SYS_CCSRBAR_DEFAULT.
4640 CONFIG_SYS_DEFAULT_IMMR must also be set to this value,
4641 for cross-platform code that uses that macro instead.
4643 - CONFIG_SYS_CCSRBAR_PHYS:
4644 Physical address of CCSR. CCSR can be relocated to a new
4645 physical address, if desired. In this case, this macro should
4646 be set to that address. Otherwise, it should be set to the
4647 same value as CONFIG_SYS_CCSRBAR_DEFAULT. For example, CCSR
4648 is typically relocated on 36-bit builds. It is recommended
4649 that this macro be defined via the _HIGH and _LOW macros:
4651 #define CONFIG_SYS_CCSRBAR_PHYS ((CONFIG_SYS_CCSRBAR_PHYS_HIGH
4652 * 1ull) << 32 | CONFIG_SYS_CCSRBAR_PHYS_LOW)
4654 - CONFIG_SYS_CCSRBAR_PHYS_HIGH:
4655 Bits 33-36 of CONFIG_SYS_CCSRBAR_PHYS. This value is typically
4656 either 0 (32-bit build) or 0xF (36-bit build). This macro is
4657 used in assembly code, so it must not contain typecasts or
4658 integer size suffixes (e.g. "ULL").
4660 - CONFIG_SYS_CCSRBAR_PHYS_LOW:
4661 Lower 32-bits of CONFIG_SYS_CCSRBAR_PHYS. This macro is
4662 used in assembly code, so it must not contain typecasts or
4663 integer size suffixes (e.g. "ULL").
4665 - CONFIG_SYS_CCSR_DO_NOT_RELOCATE:
4666 If this macro is defined, then CONFIG_SYS_CCSRBAR_PHYS will be
4667 forced to a value that ensures that CCSR is not relocated.
4669 - Floppy Disk Support:
4670 CONFIG_SYS_FDC_DRIVE_NUMBER
4672 the default drive number (default value 0)
4674 CONFIG_SYS_ISA_IO_STRIDE
4676 defines the spacing between FDC chipset registers
4679 CONFIG_SYS_ISA_IO_OFFSET
4681 defines the offset of register from address. It
4682 depends on which part of the data bus is connected to
4683 the FDC chipset. (default value 0)
4685 If CONFIG_SYS_ISA_IO_STRIDE CONFIG_SYS_ISA_IO_OFFSET and
4686 CONFIG_SYS_FDC_DRIVE_NUMBER are undefined, they take their
4689 if CONFIG_SYS_FDC_HW_INIT is defined, then the function
4690 fdc_hw_init() is called at the beginning of the FDC
4691 setup. fdc_hw_init() must be provided by the board
4692 source code. It is used to make hardware-dependent
4696 Most IDE controllers were designed to be connected with PCI
4697 interface. Only few of them were designed for AHB interface.
4698 When software is doing ATA command and data transfer to
4699 IDE devices through IDE-AHB controller, some additional
4700 registers accessing to these kind of IDE-AHB controller
4703 - CONFIG_SYS_IMMR: Physical address of the Internal Memory.
4704 DO NOT CHANGE unless you know exactly what you're
4705 doing! (11-4) [MPC8xx/82xx systems only]
4707 - CONFIG_SYS_INIT_RAM_ADDR:
4709 Start address of memory area that can be used for
4710 initial data and stack; please note that this must be
4711 writable memory that is working WITHOUT special
4712 initialization, i. e. you CANNOT use normal RAM which
4713 will become available only after programming the
4714 memory controller and running certain initialization
4717 U-Boot uses the following memory types:
4718 - MPC8xx and MPC8260: IMMR (internal memory of the CPU)
4719 - MPC824X: data cache
4720 - PPC4xx: data cache
4722 - CONFIG_SYS_GBL_DATA_OFFSET:
4724 Offset of the initial data structure in the memory
4725 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually
4726 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial
4727 data is located at the end of the available space
4728 (sometimes written as (CONFIG_SYS_INIT_RAM_SIZE -
4729 CONFIG_SYS_INIT_DATA_SIZE), and the initial stack is just
4730 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR +
4731 CONFIG_SYS_GBL_DATA_OFFSET) downward.
4734 On the MPC824X (or other systems that use the data
4735 cache for initial memory) the address chosen for
4736 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must
4737 point to an otherwise UNUSED address space between
4738 the top of RAM and the start of the PCI space.
4740 - CONFIG_SYS_SIUMCR: SIU Module Configuration (11-6)
4742 - CONFIG_SYS_SYPCR: System Protection Control (11-9)
4744 - CONFIG_SYS_TBSCR: Time Base Status and Control (11-26)
4746 - CONFIG_SYS_PISCR: Periodic Interrupt Status and Control (11-31)
4748 - CONFIG_SYS_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30)
4750 - CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27)
4752 - CONFIG_SYS_OR_TIMING_SDRAM:
4755 - CONFIG_SYS_MAMR_PTA:
4756 periodic timer for refresh
4758 - CONFIG_SYS_DER: Debug Event Register (37-47)
4760 - FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM,
4761 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP,
4762 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM,
4763 CONFIG_SYS_BR1_PRELIM:
4764 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
4766 - SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
4767 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM,
4768 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM:
4769 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
4771 - CONFIG_SYS_MAMR_PTA, CONFIG_SYS_MPTPR_2BK_4K, CONFIG_SYS_MPTPR_1BK_4K, CONFIG_SYS_MPTPR_2BK_8K,
4772 CONFIG_SYS_MPTPR_1BK_8K, CONFIG_SYS_MAMR_8COL, CONFIG_SYS_MAMR_9COL:
4773 Machine Mode Register and Memory Periodic Timer
4774 Prescaler definitions (SDRAM timing)
4776 - CONFIG_SYS_I2C_UCODE_PATCH, CONFIG_SYS_I2C_DPMEM_OFFSET [0x1FC0]:
4777 enable I2C microcode relocation patch (MPC8xx);
4778 define relocation offset in DPRAM [DSP2]
4780 - CONFIG_SYS_SMC_UCODE_PATCH, CONFIG_SYS_SMC_DPMEM_OFFSET [0x1FC0]:
4781 enable SMC microcode relocation patch (MPC8xx);
4782 define relocation offset in DPRAM [SMC1]
4784 - CONFIG_SYS_SPI_UCODE_PATCH, CONFIG_SYS_SPI_DPMEM_OFFSET [0x1FC0]:
4785 enable SPI microcode relocation patch (MPC8xx);
4786 define relocation offset in DPRAM [SCC4]
4788 - CONFIG_SYS_USE_OSCCLK:
4789 Use OSCM clock mode on MBX8xx board. Be careful,
4790 wrong setting might damage your board. Read
4791 doc/README.MBX before setting this variable!
4793 - CONFIG_SYS_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only)
4794 Offset of the bootmode word in DPRAM used by post
4795 (Power On Self Tests). This definition overrides
4796 #define'd default value in commproc.h resp.
4799 - CONFIG_SYS_PCI_SLV_MEM_LOCAL, CONFIG_SYS_PCI_SLV_MEM_BUS, CONFIG_SYS_PICMR0_MASK_ATTRIB,
4800 CONFIG_SYS_PCI_MSTR0_LOCAL, CONFIG_SYS_PCIMSK0_MASK, CONFIG_SYS_PCI_MSTR1_LOCAL,
4801 CONFIG_SYS_PCIMSK1_MASK, CONFIG_SYS_PCI_MSTR_MEM_LOCAL, CONFIG_SYS_PCI_MSTR_MEM_BUS,
4802 CONFIG_SYS_CPU_PCI_MEM_START, CONFIG_SYS_PCI_MSTR_MEM_SIZE, CONFIG_SYS_POCMR0_MASK_ATTRIB,
4803 CONFIG_SYS_PCI_MSTR_MEMIO_LOCAL, CONFIG_SYS_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START,
4804 CONFIG_SYS_PCI_MSTR_MEMIO_SIZE, CONFIG_SYS_POCMR1_MASK_ATTRIB, CONFIG_SYS_PCI_MSTR_IO_LOCAL,
4805 CONFIG_SYS_PCI_MSTR_IO_BUS, CONFIG_SYS_CPU_PCI_IO_START, CONFIG_SYS_PCI_MSTR_IO_SIZE,
4806 CONFIG_SYS_POCMR2_MASK_ATTRIB: (MPC826x only)
4807 Overrides the default PCI memory map in arch/powerpc/cpu/mpc8260/pci.c if set.
4809 - CONFIG_PCI_DISABLE_PCIE:
4810 Disable PCI-Express on systems where it is supported but not
4813 - CONFIG_PCI_ENUM_ONLY
4814 Only scan through and get the devices on the buses.
4815 Don't do any setup work, presumably because someone or
4816 something has already done it, and we don't need to do it
4817 a second time. Useful for platforms that are pre-booted
4818 by coreboot or similar.
4820 - CONFIG_PCI_INDIRECT_BRIDGE:
4821 Enable support for indirect PCI bridges.
4824 Chip has SRIO or not
4827 Board has SRIO 1 port available
4830 Board has SRIO 2 port available
4832 - CONFIG_SRIO_PCIE_BOOT_MASTER
4833 Board can support master function for Boot from SRIO and PCIE
4835 - CONFIG_SYS_SRIOn_MEM_VIRT:
4836 Virtual Address of SRIO port 'n' memory region
4838 - CONFIG_SYS_SRIOn_MEM_PHYS:
4839 Physical Address of SRIO port 'n' memory region
4841 - CONFIG_SYS_SRIOn_MEM_SIZE:
4842 Size of SRIO port 'n' memory region
4844 - CONFIG_SYS_NAND_BUSWIDTH_16BIT
4845 Defined to tell the NAND controller that the NAND chip is using
4847 Not all NAND drivers use this symbol.
4848 Example of drivers that use it:
4849 - drivers/mtd/nand/ndfc.c
4850 - drivers/mtd/nand/mxc_nand.c
4852 - CONFIG_SYS_NDFC_EBC0_CFG
4853 Sets the EBC0_CFG register for the NDFC. If not defined
4854 a default value will be used.
4857 Get DDR timing information from an I2C EEPROM. Common
4858 with pluggable memory modules such as SODIMMs
4861 I2C address of the SPD EEPROM
4863 - CONFIG_SYS_SPD_BUS_NUM
4864 If SPD EEPROM is on an I2C bus other than the first
4865 one, specify here. Note that the value must resolve
4866 to something your driver can deal with.
4868 - CONFIG_SYS_DDR_RAW_TIMING
4869 Get DDR timing information from other than SPD. Common with
4870 soldered DDR chips onboard without SPD. DDR raw timing
4871 parameters are extracted from datasheet and hard-coded into
4872 header files or board specific files.
4874 - CONFIG_FSL_DDR_INTERACTIVE
4875 Enable interactive DDR debugging. See doc/README.fsl-ddr.
4877 - CONFIG_FSL_DDR_SYNC_REFRESH
4878 Enable sync of refresh for multiple controllers.
4880 - CONFIG_FSL_DDR_BIST
4881 Enable built-in memory test for Freescale DDR controllers.
4883 - CONFIG_SYS_83XX_DDR_USES_CS0
4884 Only for 83xx systems. If specified, then DDR should
4885 be configured using CS0 and CS1 instead of CS2 and CS3.
4887 - CONFIG_ETHER_ON_FEC[12]
4888 Define to enable FEC[12] on a 8xx series processor.
4890 - CONFIG_FEC[12]_PHY
4891 Define to the hardcoded PHY address which corresponds
4892 to the given FEC; i. e.
4893 #define CONFIG_FEC1_PHY 4
4894 means that the PHY with address 4 is connected to FEC1
4896 When set to -1, means to probe for first available.
4898 - CONFIG_FEC[12]_PHY_NORXERR
4899 The PHY does not have a RXERR line (RMII only).
4900 (so program the FEC to ignore it).
4903 Enable RMII mode for all FECs.
4904 Note that this is a global option, we can't
4905 have one FEC in standard MII mode and another in RMII mode.
4907 - CONFIG_CRC32_VERIFY
4908 Add a verify option to the crc32 command.
4911 => crc32 -v <address> <count> <crc32>
4913 Where address/count indicate a memory area
4914 and crc32 is the correct crc32 which the
4918 Add the "loopw" memory command. This only takes effect if
4919 the memory commands are activated globally (CONFIG_CMD_MEM).
4922 Add the "mdc" and "mwc" memory commands. These are cyclic
4927 This command will print 4 bytes (10,11,12,13) each 500 ms.
4929 => mwc.l 100 12345678 10
4930 This command will write 12345678 to address 100 all 10 ms.
4932 This only takes effect if the memory commands are activated
4933 globally (CONFIG_CMD_MEM).
4935 - CONFIG_SKIP_LOWLEVEL_INIT
4936 [ARM, NDS32, MIPS only] If this variable is defined, then certain
4937 low level initializations (like setting up the memory
4938 controller) are omitted and/or U-Boot does not
4939 relocate itself into RAM.
4941 Normally this variable MUST NOT be defined. The only
4942 exception is when U-Boot is loaded (to RAM) by some
4943 other boot loader or by a debugger which performs
4944 these initializations itself.
4947 Modifies the behaviour of start.S when compiling a loader
4948 that is executed before the actual U-Boot. E.g. when
4949 compiling a NAND SPL.
4952 Modifies the behaviour of start.S when compiling a loader
4953 that is executed after the SPL and before the actual U-Boot.
4954 It is loaded by the SPL.
4956 - CONFIG_SYS_MPC85XX_NO_RESETVEC
4957 Only for 85xx systems. If this variable is specified, the section
4958 .resetvec is not kept and the section .bootpg is placed in the
4959 previous 4k of the .text section.
4961 - CONFIG_ARCH_MAP_SYSMEM
4962 Generally U-Boot (and in particular the md command) uses
4963 effective address. It is therefore not necessary to regard
4964 U-Boot address as virtual addresses that need to be translated
4965 to physical addresses. However, sandbox requires this, since
4966 it maintains its own little RAM buffer which contains all
4967 addressable memory. This option causes some memory accesses
4968 to be mapped through map_sysmem() / unmap_sysmem().
4970 - CONFIG_USE_ARCH_MEMCPY
4971 CONFIG_USE_ARCH_MEMSET
4972 If these options are used a optimized version of memcpy/memset will
4973 be used if available. These functions may be faster under some
4974 conditions but may increase the binary size.
4976 - CONFIG_X86_RESET_VECTOR
4977 If defined, the x86 reset vector code is included. This is not
4978 needed when U-Boot is running from Coreboot.
4981 Defines the MPU clock speed (in MHz).
4983 NOTE : currently only supported on AM335x platforms.
4985 - CONFIG_SPL_AM33XX_ENABLE_RTC32K_OSC:
4986 Enables the RTC32K OSC on AM33xx based plattforms
4988 - CONFIG_SYS_NAND_NO_SUBPAGE_WRITE
4989 Option to disable subpage write in NAND driver
4990 driver that uses this:
4991 drivers/mtd/nand/davinci_nand.c
4993 Freescale QE/FMAN Firmware Support:
4994 -----------------------------------
4996 The Freescale QUICCEngine (QE) and Frame Manager (FMAN) both support the
4997 loading of "firmware", which is encoded in the QE firmware binary format.
4998 This firmware often needs to be loaded during U-Boot booting, so macros
4999 are used to identify the storage device (NOR flash, SPI, etc) and the address
5002 - CONFIG_SYS_FMAN_FW_ADDR
5003 The address in the storage device where the FMAN microcode is located. The
5004 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
5007 - CONFIG_SYS_QE_FW_ADDR
5008 The address in the storage device where the QE microcode is located. The
5009 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
5012 - CONFIG_SYS_QE_FMAN_FW_LENGTH
5013 The maximum possible size of the firmware. The firmware binary format
5014 has a field that specifies the actual size of the firmware, but it
5015 might not be possible to read any part of the firmware unless some
5016 local storage is allocated to hold the entire firmware first.
5018 - CONFIG_SYS_QE_FMAN_FW_IN_NOR
5019 Specifies that QE/FMAN firmware is located in NOR flash, mapped as
5020 normal addressable memory via the LBC. CONFIG_SYS_FMAN_FW_ADDR is the
5021 virtual address in NOR flash.
5023 - CONFIG_SYS_QE_FMAN_FW_IN_NAND
5024 Specifies that QE/FMAN firmware is located in NAND flash.
5025 CONFIG_SYS_FMAN_FW_ADDR is the offset within NAND flash.
5027 - CONFIG_SYS_QE_FMAN_FW_IN_MMC
5028 Specifies that QE/FMAN firmware is located on the primary SD/MMC
5029 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
5031 - CONFIG_SYS_QE_FMAN_FW_IN_SPIFLASH
5032 Specifies that QE/FMAN firmware is located on the primary SPI
5033 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
5035 - CONFIG_SYS_QE_FMAN_FW_IN_REMOTE
5036 Specifies that QE/FMAN firmware is located in the remote (master)
5037 memory space. CONFIG_SYS_FMAN_FW_ADDR is a virtual address which
5038 can be mapped from slave TLB->slave LAW->slave SRIO or PCIE outbound
5039 window->master inbound window->master LAW->the ucode address in
5040 master's memory space.
5042 Freescale Layerscape Management Complex Firmware Support:
5043 ---------------------------------------------------------
5044 The Freescale Layerscape Management Complex (MC) supports the loading of
5046 This firmware often needs to be loaded during U-Boot booting, so macros
5047 are used to identify the storage device (NOR flash, SPI, etc) and the address
5050 - CONFIG_FSL_MC_ENET
5051 Enable the MC driver for Layerscape SoCs.
5053 - CONFIG_SYS_LS_MC_FW_ADDR
5054 The address in the storage device where the firmware is located. The
5055 meaning of this address depends on which CONFIG_SYS_LS_MC_FW_IN_xxx macro
5058 - CONFIG_SYS_LS_MC_FW_LENGTH
5059 The maximum possible size of the firmware. The firmware binary format
5060 has a field that specifies the actual size of the firmware, but it
5061 might not be possible to read any part of the firmware unless some
5062 local storage is allocated to hold the entire firmware first.
5064 - CONFIG_SYS_LS_MC_FW_IN_NOR
5065 Specifies that MC firmware is located in NOR flash, mapped as
5066 normal addressable memory via the LBC. CONFIG_SYS_LS_MC_FW_ADDR is the
5067 virtual address in NOR flash.
5069 Freescale Layerscape Debug Server Support:
5070 -------------------------------------------
5071 The Freescale Layerscape Debug Server Support supports the loading of
5072 "Debug Server firmware" and triggering SP boot-rom.
5073 This firmware often needs to be loaded during U-Boot booting.
5075 - CONFIG_FSL_DEBUG_SERVER
5076 Enable the Debug Server for Layerscape SoCs.
5078 - CONFIG_SYS_DEBUG_SERVER_DRAM_BLOCK_MIN_SIZE
5079 Define minimum DDR size required for debug server image
5081 - CONFIG_SYS_MEM_TOP_HIDE_MIN
5082 Define minimum DDR size to be hided from top of the DDR memory
5087 In order to achieve reproducible builds, timestamps used in the U-Boot build
5088 process have to be set to a fixed value.
5090 This is done using the SOURCE_DATE_EPOCH environment variable.
5091 SOURCE_DATE_EPOCH is to be set on the build host's shell, not as a configuration
5092 option for U-Boot or an environment variable in U-Boot.
5094 SOURCE_DATE_EPOCH should be set to a number of seconds since the epoch, in UTC.
5096 Building the Software:
5097 ======================
5099 Building U-Boot has been tested in several native build environments
5100 and in many different cross environments. Of course we cannot support
5101 all possibly existing versions of cross development tools in all
5102 (potentially obsolete) versions. In case of tool chain problems we
5103 recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK)
5104 which is extensively used to build and test U-Boot.
5106 If you are not using a native environment, it is assumed that you
5107 have GNU cross compiling tools available in your path. In this case,
5108 you must set the environment variable CROSS_COMPILE in your shell.
5109 Note that no changes to the Makefile or any other source files are
5110 necessary. For example using the ELDK on a 4xx CPU, please enter:
5112 $ CROSS_COMPILE=ppc_4xx-
5113 $ export CROSS_COMPILE
5115 Note: If you wish to generate Windows versions of the utilities in
5116 the tools directory you can use the MinGW toolchain
5117 (http://www.mingw.org). Set your HOST tools to the MinGW
5118 toolchain and execute 'make tools'. For example:
5120 $ make HOSTCC=i586-mingw32msvc-gcc HOSTSTRIP=i586-mingw32msvc-strip tools
5122 Binaries such as tools/mkimage.exe will be created which can
5123 be executed on computers running Windows.
5125 U-Boot is intended to be simple to build. After installing the
5126 sources you must configure U-Boot for one specific board type. This
5131 where "NAME_defconfig" is the name of one of the existing configu-
5132 rations; see boards.cfg for supported names.
5134 Note: for some board special configuration names may exist; check if
5135 additional information is available from the board vendor; for
5136 instance, the TQM823L systems are available without (standard)
5137 or with LCD support. You can select such additional "features"
5138 when choosing the configuration, i. e.
5140 make TQM823L_defconfig
5141 - will configure for a plain TQM823L, i. e. no LCD support
5143 make TQM823L_LCD_defconfig
5144 - will configure for a TQM823L with U-Boot console on LCD
5149 Finally, type "make all", and you should get some working U-Boot
5150 images ready for download to / installation on your system:
5152 - "u-boot.bin" is a raw binary image
5153 - "u-boot" is an image in ELF binary format
5154 - "u-boot.srec" is in Motorola S-Record format
5156 By default the build is performed locally and the objects are saved
5157 in the source directory. One of the two methods can be used to change
5158 this behavior and build U-Boot to some external directory:
5160 1. Add O= to the make command line invocations:
5162 make O=/tmp/build distclean
5163 make O=/tmp/build NAME_defconfig
5164 make O=/tmp/build all
5166 2. Set environment variable KBUILD_OUTPUT to point to the desired location:
5168 export KBUILD_OUTPUT=/tmp/build
5173 Note that the command line "O=" setting overrides the KBUILD_OUTPUT environment
5177 Please be aware that the Makefiles assume you are using GNU make, so
5178 for instance on NetBSD you might need to use "gmake" instead of
5182 If the system board that you have is not listed, then you will need
5183 to port U-Boot to your hardware platform. To do this, follow these
5186 1. Add a new configuration option for your board to the toplevel
5187 "boards.cfg" file, using the existing entries as examples.
5188 Follow the instructions there to keep the boards in order.
5189 2. Create a new directory to hold your board specific code. Add any
5190 files you need. In your board directory, you will need at least
5191 the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds".
5192 3. Create a new configuration file "include/configs/<board>.h" for
5194 3. If you're porting U-Boot to a new CPU, then also create a new
5195 directory to hold your CPU specific code. Add any files you need.
5196 4. Run "make <board>_defconfig" with your new name.
5197 5. Type "make", and you should get a working "u-boot.srec" file
5198 to be installed on your target system.
5199 6. Debug and solve any problems that might arise.
5200 [Of course, this last step is much harder than it sounds.]
5203 Testing of U-Boot Modifications, Ports to New Hardware, etc.:
5204 ==============================================================
5206 If you have modified U-Boot sources (for instance added a new board
5207 or support for new devices, a new CPU, etc.) you are expected to
5208 provide feedback to the other developers. The feedback normally takes
5209 the form of a "patch", i. e. a context diff against a certain (latest
5210 official or latest in the git repository) version of U-Boot sources.
5212 But before you submit such a patch, please verify that your modifi-
5213 cation did not break existing code. At least make sure that *ALL* of
5214 the supported boards compile WITHOUT ANY compiler warnings. To do so,
5215 just run the "MAKEALL" script, which will configure and build U-Boot
5216 for ALL supported system. Be warned, this will take a while. You can
5217 select which (cross) compiler to use by passing a `CROSS_COMPILE'
5218 environment variable to the script, i. e. to use the ELDK cross tools
5221 CROSS_COMPILE=ppc_8xx- MAKEALL
5223 or to build on a native PowerPC system you can type
5225 CROSS_COMPILE=' ' MAKEALL
5227 When using the MAKEALL script, the default behaviour is to build
5228 U-Boot in the source directory. This location can be changed by
5229 setting the BUILD_DIR environment variable. Also, for each target
5230 built, the MAKEALL script saves two log files (<target>.ERR and
5231 <target>.MAKEALL) in the <source dir>/LOG directory. This default
5232 location can be changed by setting the MAKEALL_LOGDIR environment
5233 variable. For example:
5235 export BUILD_DIR=/tmp/build
5236 export MAKEALL_LOGDIR=/tmp/log
5237 CROSS_COMPILE=ppc_8xx- MAKEALL
5239 With the above settings build objects are saved in the /tmp/build,
5240 log files are saved in the /tmp/log and the source tree remains clean
5241 during the whole build process.
5244 See also "U-Boot Porting Guide" below.
5247 Monitor Commands - Overview:
5248 ============================
5250 go - start application at address 'addr'
5251 run - run commands in an environment variable
5252 bootm - boot application image from memory
5253 bootp - boot image via network using BootP/TFTP protocol
5254 bootz - boot zImage from memory
5255 tftpboot- boot image via network using TFTP protocol
5256 and env variables "ipaddr" and "serverip"
5257 (and eventually "gatewayip")
5258 tftpput - upload a file via network using TFTP protocol
5259 rarpboot- boot image via network using RARP/TFTP protocol
5260 diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
5261 loads - load S-Record file over serial line
5262 loadb - load binary file over serial line (kermit mode)
5264 mm - memory modify (auto-incrementing)
5265 nm - memory modify (constant address)
5266 mw - memory write (fill)
5268 cmp - memory compare
5269 crc32 - checksum calculation
5270 i2c - I2C sub-system
5271 sspi - SPI utility commands
5272 base - print or set address offset
5273 printenv- print environment variables
5274 setenv - set environment variables
5275 saveenv - save environment variables to persistent storage
5276 protect - enable or disable FLASH write protection
5277 erase - erase FLASH memory
5278 flinfo - print FLASH memory information
5279 nand - NAND memory operations (see doc/README.nand)
5280 bdinfo - print Board Info structure
5281 iminfo - print header information for application image
5282 coninfo - print console devices and informations
5283 ide - IDE sub-system
5284 loop - infinite loop on address range
5285 loopw - infinite write loop on address range
5286 mtest - simple RAM test
5287 icache - enable or disable instruction cache
5288 dcache - enable or disable data cache
5289 reset - Perform RESET of the CPU
5290 echo - echo args to console
5291 version - print monitor version
5292 help - print online help
5293 ? - alias for 'help'
5296 Monitor Commands - Detailed Description:
5297 ========================================
5301 For now: just type "help <command>".
5304 Environment Variables:
5305 ======================
5307 U-Boot supports user configuration using Environment Variables which
5308 can be made persistent by saving to Flash memory.
5310 Environment Variables are set using "setenv", printed using
5311 "printenv", and saved to Flash using "saveenv". Using "setenv"
5312 without a value can be used to delete a variable from the
5313 environment. As long as you don't save the environment you are
5314 working with an in-memory copy. In case the Flash area containing the
5315 environment is erased by accident, a default environment is provided.
5317 Some configuration options can be set using Environment Variables.
5319 List of environment variables (most likely not complete):
5321 baudrate - see CONFIG_BAUDRATE
5323 bootdelay - see CONFIG_BOOTDELAY
5325 bootcmd - see CONFIG_BOOTCOMMAND
5327 bootargs - Boot arguments when booting an RTOS image
5329 bootfile - Name of the image to load with TFTP
5331 bootm_low - Memory range available for image processing in the bootm
5332 command can be restricted. This variable is given as
5333 a hexadecimal number and defines lowest address allowed
5334 for use by the bootm command. See also "bootm_size"
5335 environment variable. Address defined by "bootm_low" is
5336 also the base of the initial memory mapping for the Linux
5337 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ and
5340 bootm_mapsize - Size of the initial memory mapping for the Linux kernel.
5341 This variable is given as a hexadecimal number and it
5342 defines the size of the memory region starting at base
5343 address bootm_low that is accessible by the Linux kernel
5344 during early boot. If unset, CONFIG_SYS_BOOTMAPSZ is used
5345 as the default value if it is defined, and bootm_size is
5348 bootm_size - Memory range available for image processing in the bootm
5349 command can be restricted. This variable is given as
5350 a hexadecimal number and defines the size of the region
5351 allowed for use by the bootm command. See also "bootm_low"
5352 environment variable.
5354 updatefile - Location of the software update file on a TFTP server, used
5355 by the automatic software update feature. Please refer to
5356 documentation in doc/README.update for more details.
5358 autoload - if set to "no" (any string beginning with 'n'),
5359 "bootp" will just load perform a lookup of the
5360 configuration from the BOOTP server, but not try to
5361 load any image using TFTP
5363 autostart - if set to "yes", an image loaded using the "bootp",
5364 "rarpboot", "tftpboot" or "diskboot" commands will
5365 be automatically started (by internally calling
5368 If set to "no", a standalone image passed to the
5369 "bootm" command will be copied to the load address
5370 (and eventually uncompressed), but NOT be started.
5371 This can be used to load and uncompress arbitrary
5374 fdt_high - if set this restricts the maximum address that the
5375 flattened device tree will be copied into upon boot.
5376 For example, if you have a system with 1 GB memory
5377 at physical address 0x10000000, while Linux kernel
5378 only recognizes the first 704 MB as low memory, you
5379 may need to set fdt_high as 0x3C000000 to have the
5380 device tree blob be copied to the maximum address
5381 of the 704 MB low memory, so that Linux kernel can
5382 access it during the boot procedure.
5384 If this is set to the special value 0xFFFFFFFF then
5385 the fdt will not be copied at all on boot. For this
5386 to work it must reside in writable memory, have
5387 sufficient padding on the end of it for u-boot to
5388 add the information it needs into it, and the memory
5389 must be accessible by the kernel.
5391 fdtcontroladdr- if set this is the address of the control flattened
5392 device tree used by U-Boot when CONFIG_OF_CONTROL is
5395 i2cfast - (PPC405GP|PPC405EP only)
5396 if set to 'y' configures Linux I2C driver for fast
5397 mode (400kHZ). This environment variable is used in
5398 initialization code. So, for changes to be effective
5399 it must be saved and board must be reset.
5401 initrd_high - restrict positioning of initrd images:
5402 If this variable is not set, initrd images will be
5403 copied to the highest possible address in RAM; this
5404 is usually what you want since it allows for
5405 maximum initrd size. If for some reason you want to
5406 make sure that the initrd image is loaded below the
5407 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment
5408 variable to a value of "no" or "off" or "0".
5409 Alternatively, you can set it to a maximum upper
5410 address to use (U-Boot will still check that it
5411 does not overwrite the U-Boot stack and data).
5413 For instance, when you have a system with 16 MB
5414 RAM, and want to reserve 4 MB from use by Linux,
5415 you can do this by adding "mem=12M" to the value of
5416 the "bootargs" variable. However, now you must make
5417 sure that the initrd image is placed in the first
5418 12 MB as well - this can be done with
5420 setenv initrd_high 00c00000
5422 If you set initrd_high to 0xFFFFFFFF, this is an
5423 indication to U-Boot that all addresses are legal
5424 for the Linux kernel, including addresses in flash
5425 memory. In this case U-Boot will NOT COPY the
5426 ramdisk at all. This may be useful to reduce the
5427 boot time on your system, but requires that this
5428 feature is supported by your Linux kernel.
5430 ipaddr - IP address; needed for tftpboot command
5432 loadaddr - Default load address for commands like "bootp",
5433 "rarpboot", "tftpboot", "loadb" or "diskboot"
5435 loads_echo - see CONFIG_LOADS_ECHO
5437 serverip - TFTP server IP address; needed for tftpboot command
5439 bootretry - see CONFIG_BOOT_RETRY_TIME
5441 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
5443 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
5445 ethprime - controls which interface is used first.
5447 ethact - controls which interface is currently active.
5448 For example you can do the following
5450 => setenv ethact FEC
5451 => ping 192.168.0.1 # traffic sent on FEC
5452 => setenv ethact SCC
5453 => ping 10.0.0.1 # traffic sent on SCC
5455 ethrotate - When set to "no" U-Boot does not go through all
5456 available network interfaces.
5457 It just stays at the currently selected interface.
5459 netretry - When set to "no" each network operation will
5460 either succeed or fail without retrying.
5461 When set to "once" the network operation will
5462 fail when all the available network interfaces
5463 are tried once without success.
5464 Useful on scripts which control the retry operation
5467 npe_ucode - set load address for the NPE microcode
5469 silent_linux - If set then Linux will be told to boot silently, by
5470 changing the console to be empty. If "yes" it will be
5471 made silent. If "no" it will not be made silent. If
5472 unset, then it will be made silent if the U-Boot console
5475 tftpsrcport - If this is set, the value is used for TFTP's
5478 tftpdstport - If this is set, the value is used for TFTP's UDP
5479 destination port instead of the Well Know Port 69.
5481 tftpblocksize - Block size to use for TFTP transfers; if not set,
5482 we use the TFTP server's default block size
5484 tftptimeout - Retransmission timeout for TFTP packets (in milli-
5485 seconds, minimum value is 1000 = 1 second). Defines
5486 when a packet is considered to be lost so it has to
5487 be retransmitted. The default is 5000 = 5 seconds.
5488 Lowering this value may make downloads succeed
5489 faster in networks with high packet loss rates or
5490 with unreliable TFTP servers.
5492 vlan - When set to a value < 4095 the traffic over
5493 Ethernet is encapsulated/received over 802.1q
5496 The following image location variables contain the location of images
5497 used in booting. The "Image" column gives the role of the image and is
5498 not an environment variable name. The other columns are environment
5499 variable names. "File Name" gives the name of the file on a TFTP
5500 server, "RAM Address" gives the location in RAM the image will be
5501 loaded to, and "Flash Location" gives the image's address in NOR
5502 flash or offset in NAND flash.
5504 *Note* - these variables don't have to be defined for all boards, some
5505 boards currently use other variables for these purposes, and some
5506 boards use these variables for other purposes.
5508 Image File Name RAM Address Flash Location
5509 ----- --------- ----------- --------------
5510 u-boot u-boot u-boot_addr_r u-boot_addr
5511 Linux kernel bootfile kernel_addr_r kernel_addr
5512 device tree blob fdtfile fdt_addr_r fdt_addr
5513 ramdisk ramdiskfile ramdisk_addr_r ramdisk_addr
5515 The following environment variables may be used and automatically
5516 updated by the network boot commands ("bootp" and "rarpboot"),
5517 depending the information provided by your boot server:
5519 bootfile - see above
5520 dnsip - IP address of your Domain Name Server
5521 dnsip2 - IP address of your secondary Domain Name Server
5522 gatewayip - IP address of the Gateway (Router) to use
5523 hostname - Target hostname
5525 netmask - Subnet Mask
5526 rootpath - Pathname of the root filesystem on the NFS server
5527 serverip - see above
5530 There are two special Environment Variables:
5532 serial# - contains hardware identification information such
5533 as type string and/or serial number
5534 ethaddr - Ethernet address
5536 These variables can be set only once (usually during manufacturing of
5537 the board). U-Boot refuses to delete or overwrite these variables
5538 once they have been set once.
5541 Further special Environment Variables:
5543 ver - Contains the U-Boot version string as printed
5544 with the "version" command. This variable is
5545 readonly (see CONFIG_VERSION_VARIABLE).
5548 Please note that changes to some configuration parameters may take
5549 only effect after the next boot (yes, that's just like Windoze :-).
5552 Callback functions for environment variables:
5553 ---------------------------------------------
5555 For some environment variables, the behavior of u-boot needs to change
5556 when their values are changed. This functionality allows functions to
5557 be associated with arbitrary variables. On creation, overwrite, or
5558 deletion, the callback will provide the opportunity for some side
5559 effect to happen or for the change to be rejected.
5561 The callbacks are named and associated with a function using the
5562 U_BOOT_ENV_CALLBACK macro in your board or driver code.
5564 These callbacks are associated with variables in one of two ways. The
5565 static list can be added to by defining CONFIG_ENV_CALLBACK_LIST_STATIC
5566 in the board configuration to a string that defines a list of
5567 associations. The list must be in the following format:
5569 entry = variable_name[:callback_name]
5572 If the callback name is not specified, then the callback is deleted.
5573 Spaces are also allowed anywhere in the list.
5575 Callbacks can also be associated by defining the ".callbacks" variable
5576 with the same list format above. Any association in ".callbacks" will
5577 override any association in the static list. You can define
5578 CONFIG_ENV_CALLBACK_LIST_DEFAULT to a list (string) to define the
5579 ".callbacks" environment variable in the default or embedded environment.
5581 If CONFIG_REGEX is defined, the variable_name above is evaluated as a
5582 regular expression. This allows multiple variables to be connected to
5583 the same callback without explicitly listing them all out.
5586 Command Line Parsing:
5587 =====================
5589 There are two different command line parsers available with U-Boot:
5590 the old "simple" one, and the much more powerful "hush" shell:
5592 Old, simple command line parser:
5593 --------------------------------
5595 - supports environment variables (through setenv / saveenv commands)
5596 - several commands on one line, separated by ';'
5597 - variable substitution using "... ${name} ..." syntax
5598 - special characters ('$', ';') can be escaped by prefixing with '\',
5600 setenv bootcmd bootm \${address}
5601 - You can also escape text by enclosing in single apostrophes, for example:
5602 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
5607 - similar to Bourne shell, with control structures like
5608 if...then...else...fi, for...do...done; while...do...done,
5609 until...do...done, ...
5610 - supports environment ("global") variables (through setenv / saveenv
5611 commands) and local shell variables (through standard shell syntax
5612 "name=value"); only environment variables can be used with "run"
5618 (1) If a command line (or an environment variable executed by a "run"
5619 command) contains several commands separated by semicolon, and
5620 one of these commands fails, then the remaining commands will be
5623 (2) If you execute several variables with one call to run (i. e.
5624 calling run with a list of variables as arguments), any failing
5625 command will cause "run" to terminate, i. e. the remaining
5626 variables are not executed.
5628 Note for Redundant Ethernet Interfaces:
5629 =======================================
5631 Some boards come with redundant Ethernet interfaces; U-Boot supports
5632 such configurations and is capable of automatic selection of a
5633 "working" interface when needed. MAC assignment works as follows:
5635 Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
5636 MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
5637 "eth1addr" (=>eth1), "eth2addr", ...
5639 If the network interface stores some valid MAC address (for instance
5640 in SROM), this is used as default address if there is NO correspon-
5641 ding setting in the environment; if the corresponding environment
5642 variable is set, this overrides the settings in the card; that means:
5644 o If the SROM has a valid MAC address, and there is no address in the
5645 environment, the SROM's address is used.
5647 o If there is no valid address in the SROM, and a definition in the
5648 environment exists, then the value from the environment variable is
5651 o If both the SROM and the environment contain a MAC address, and
5652 both addresses are the same, this MAC address is used.
5654 o If both the SROM and the environment contain a MAC address, and the
5655 addresses differ, the value from the environment is used and a
5658 o If neither SROM nor the environment contain a MAC address, an error
5659 is raised. If CONFIG_NET_RANDOM_ETHADDR is defined, then in this case
5660 a random, locally-assigned MAC is used.
5662 If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses
5663 will be programmed into hardware as part of the initialization process. This
5664 may be skipped by setting the appropriate 'ethmacskip' environment variable.
5665 The naming convention is as follows:
5666 "ethmacskip" (=>eth0), "eth1macskip" (=>eth1) etc.
5671 U-Boot is capable of booting (and performing other auxiliary operations on)
5672 images in two formats:
5674 New uImage format (FIT)
5675 -----------------------
5677 Flexible and powerful format based on Flattened Image Tree -- FIT (similar
5678 to Flattened Device Tree). It allows the use of images with multiple
5679 components (several kernels, ramdisks, etc.), with contents protected by
5680 SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory.
5686 Old image format is based on binary files which can be basically anything,
5687 preceded by a special header; see the definitions in include/image.h for
5688 details; basically, the header defines the following image properties:
5690 * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
5691 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
5692 LynxOS, pSOS, QNX, RTEMS, INTEGRITY;
5693 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS,
5695 * Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86,
5696 IA64, MIPS, NDS32, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
5697 Currently supported: ARM, AVR32, Intel x86, MIPS, NDS32, Nios II, PowerPC).
5698 * Compression Type (uncompressed, gzip, bzip2)
5704 The header is marked by a special Magic Number, and both the header
5705 and the data portions of the image are secured against corruption by
5712 Although U-Boot should support any OS or standalone application
5713 easily, the main focus has always been on Linux during the design of
5716 U-Boot includes many features that so far have been part of some
5717 special "boot loader" code within the Linux kernel. Also, any
5718 "initrd" images to be used are no longer part of one big Linux image;
5719 instead, kernel and "initrd" are separate images. This implementation
5720 serves several purposes:
5722 - the same features can be used for other OS or standalone
5723 applications (for instance: using compressed images to reduce the
5724 Flash memory footprint)
5726 - it becomes much easier to port new Linux kernel versions because
5727 lots of low-level, hardware dependent stuff are done by U-Boot
5729 - the same Linux kernel image can now be used with different "initrd"
5730 images; of course this also means that different kernel images can
5731 be run with the same "initrd". This makes testing easier (you don't
5732 have to build a new "zImage.initrd" Linux image when you just
5733 change a file in your "initrd"). Also, a field-upgrade of the
5734 software is easier now.
5740 Porting Linux to U-Boot based systems:
5741 ---------------------------------------
5743 U-Boot cannot save you from doing all the necessary modifications to
5744 configure the Linux device drivers for use with your target hardware
5745 (no, we don't intend to provide a full virtual machine interface to
5748 But now you can ignore ALL boot loader code (in arch/powerpc/mbxboot).
5750 Just make sure your machine specific header file (for instance
5751 include/asm-ppc/tqm8xx.h) includes the same definition of the Board
5752 Information structure as we define in include/asm-<arch>/u-boot.h,
5753 and make sure that your definition of IMAP_ADDR uses the same value
5754 as your U-Boot configuration in CONFIG_SYS_IMMR.
5756 Note that U-Boot now has a driver model, a unified model for drivers.
5757 If you are adding a new driver, plumb it into driver model. If there
5758 is no uclass available, you are encouraged to create one. See
5762 Configuring the Linux kernel:
5763 -----------------------------
5765 No specific requirements for U-Boot. Make sure you have some root
5766 device (initial ramdisk, NFS) for your target system.
5769 Building a Linux Image:
5770 -----------------------
5772 With U-Boot, "normal" build targets like "zImage" or "bzImage" are
5773 not used. If you use recent kernel source, a new build target
5774 "uImage" will exist which automatically builds an image usable by
5775 U-Boot. Most older kernels also have support for a "pImage" target,
5776 which was introduced for our predecessor project PPCBoot and uses a
5777 100% compatible format.
5781 make TQM850L_defconfig
5786 The "uImage" build target uses a special tool (in 'tools/mkimage') to
5787 encapsulate a compressed Linux kernel image with header information,
5788 CRC32 checksum etc. for use with U-Boot. This is what we are doing:
5790 * build a standard "vmlinux" kernel image (in ELF binary format):
5792 * convert the kernel into a raw binary image:
5794 ${CROSS_COMPILE}-objcopy -O binary \
5795 -R .note -R .comment \
5796 -S vmlinux linux.bin
5798 * compress the binary image:
5802 * package compressed binary image for U-Boot:
5804 mkimage -A ppc -O linux -T kernel -C gzip \
5805 -a 0 -e 0 -n "Linux Kernel Image" \
5806 -d linux.bin.gz uImage
5809 The "mkimage" tool can also be used to create ramdisk images for use
5810 with U-Boot, either separated from the Linux kernel image, or
5811 combined into one file. "mkimage" encapsulates the images with a 64
5812 byte header containing information about target architecture,
5813 operating system, image type, compression method, entry points, time
5814 stamp, CRC32 checksums, etc.
5816 "mkimage" can be called in two ways: to verify existing images and
5817 print the header information, or to build new images.
5819 In the first form (with "-l" option) mkimage lists the information
5820 contained in the header of an existing U-Boot image; this includes
5821 checksum verification:
5823 tools/mkimage -l image
5824 -l ==> list image header information
5826 The second form (with "-d" option) is used to build a U-Boot image
5827 from a "data file" which is used as image payload:
5829 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
5830 -n name -d data_file image
5831 -A ==> set architecture to 'arch'
5832 -O ==> set operating system to 'os'
5833 -T ==> set image type to 'type'
5834 -C ==> set compression type 'comp'
5835 -a ==> set load address to 'addr' (hex)
5836 -e ==> set entry point to 'ep' (hex)
5837 -n ==> set image name to 'name'
5838 -d ==> use image data from 'datafile'
5840 Right now, all Linux kernels for PowerPC systems use the same load
5841 address (0x00000000), but the entry point address depends on the
5844 - 2.2.x kernels have the entry point at 0x0000000C,
5845 - 2.3.x and later kernels have the entry point at 0x00000000.
5847 So a typical call to build a U-Boot image would read:
5849 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
5850 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
5851 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz \
5852 > examples/uImage.TQM850L
5853 Image Name: 2.4.4 kernel for TQM850L
5854 Created: Wed Jul 19 02:34:59 2000
5855 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5856 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
5857 Load Address: 0x00000000
5858 Entry Point: 0x00000000
5860 To verify the contents of the image (or check for corruption):
5862 -> tools/mkimage -l examples/uImage.TQM850L
5863 Image Name: 2.4.4 kernel for TQM850L
5864 Created: Wed Jul 19 02:34:59 2000
5865 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5866 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
5867 Load Address: 0x00000000
5868 Entry Point: 0x00000000
5870 NOTE: for embedded systems where boot time is critical you can trade
5871 speed for memory and install an UNCOMPRESSED image instead: this
5872 needs more space in Flash, but boots much faster since it does not
5873 need to be uncompressed:
5875 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz
5876 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
5877 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
5878 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux \
5879 > examples/uImage.TQM850L-uncompressed
5880 Image Name: 2.4.4 kernel for TQM850L
5881 Created: Wed Jul 19 02:34:59 2000
5882 Image Type: PowerPC Linux Kernel Image (uncompressed)
5883 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
5884 Load Address: 0x00000000
5885 Entry Point: 0x00000000
5888 Similar you can build U-Boot images from a 'ramdisk.image.gz' file
5889 when your kernel is intended to use an initial ramdisk:
5891 -> tools/mkimage -n 'Simple Ramdisk Image' \
5892 > -A ppc -O linux -T ramdisk -C gzip \
5893 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
5894 Image Name: Simple Ramdisk Image
5895 Created: Wed Jan 12 14:01:50 2000
5896 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5897 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
5898 Load Address: 0x00000000
5899 Entry Point: 0x00000000
5901 The "dumpimage" is a tool to disassemble images built by mkimage. Its "-i"
5902 option performs the converse operation of the mkimage's second form (the "-d"
5903 option). Given an image built by mkimage, the dumpimage extracts a "data file"
5906 tools/dumpimage -i image -T type -p position data_file
5907 -i ==> extract from the 'image' a specific 'data_file'
5908 -T ==> set image type to 'type'
5909 -p ==> 'position' (starting at 0) of the 'data_file' inside the 'image'
5912 Installing a Linux Image:
5913 -------------------------
5915 To downloading a U-Boot image over the serial (console) interface,
5916 you must convert the image to S-Record format:
5918 objcopy -I binary -O srec examples/image examples/image.srec
5920 The 'objcopy' does not understand the information in the U-Boot
5921 image header, so the resulting S-Record file will be relative to
5922 address 0x00000000. To load it to a given address, you need to
5923 specify the target address as 'offset' parameter with the 'loads'
5926 Example: install the image to address 0x40100000 (which on the
5927 TQM8xxL is in the first Flash bank):
5929 => erase 40100000 401FFFFF
5935 ## Ready for S-Record download ...
5936 ~>examples/image.srec
5937 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
5939 15989 15990 15991 15992
5940 [file transfer complete]
5942 ## Start Addr = 0x00000000
5945 You can check the success of the download using the 'iminfo' command;
5946 this includes a checksum verification so you can be sure no data
5947 corruption happened:
5951 ## Checking Image at 40100000 ...
5952 Image Name: 2.2.13 for initrd on TQM850L
5953 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5954 Data Size: 335725 Bytes = 327 kB = 0 MB
5955 Load Address: 00000000
5956 Entry Point: 0000000c
5957 Verifying Checksum ... OK
5963 The "bootm" command is used to boot an application that is stored in
5964 memory (RAM or Flash). In case of a Linux kernel image, the contents
5965 of the "bootargs" environment variable is passed to the kernel as
5966 parameters. You can check and modify this variable using the
5967 "printenv" and "setenv" commands:
5970 => printenv bootargs
5971 bootargs=root=/dev/ram
5973 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5975 => printenv bootargs
5976 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5979 ## Booting Linux kernel at 40020000 ...
5980 Image Name: 2.2.13 for NFS on TQM850L
5981 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5982 Data Size: 381681 Bytes = 372 kB = 0 MB
5983 Load Address: 00000000
5984 Entry Point: 0000000c
5985 Verifying Checksum ... OK
5986 Uncompressing Kernel Image ... OK
5987 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
5988 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5989 time_init: decrementer frequency = 187500000/60
5990 Calibrating delay loop... 49.77 BogoMIPS
5991 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
5994 If you want to boot a Linux kernel with initial RAM disk, you pass
5995 the memory addresses of both the kernel and the initrd image (PPBCOOT
5996 format!) to the "bootm" command:
5998 => imi 40100000 40200000
6000 ## Checking Image at 40100000 ...
6001 Image Name: 2.2.13 for initrd on TQM850L
6002 Image Type: PowerPC Linux Kernel Image (gzip compressed)
6003 Data Size: 335725 Bytes = 327 kB = 0 MB
6004 Load Address: 00000000
6005 Entry Point: 0000000c
6006 Verifying Checksum ... OK
6008 ## Checking Image at 40200000 ...
6009 Image Name: Simple Ramdisk Image
6010 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
6011 Data Size: 566530 Bytes = 553 kB = 0 MB
6012 Load Address: 00000000
6013 Entry Point: 00000000
6014 Verifying Checksum ... OK
6016 => bootm 40100000 40200000
6017 ## Booting Linux kernel at 40100000 ...
6018 Image Name: 2.2.13 for initrd on TQM850L
6019 Image Type: PowerPC Linux Kernel Image (gzip compressed)
6020 Data Size: 335725 Bytes = 327 kB = 0 MB
6021 Load Address: 00000000
6022 Entry Point: 0000000c
6023 Verifying Checksum ... OK
6024 Uncompressing Kernel Image ... OK
6025 ## Loading RAMDisk Image at 40200000 ...
6026 Image Name: Simple Ramdisk Image
6027 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
6028 Data Size: 566530 Bytes = 553 kB = 0 MB
6029 Load Address: 00000000
6030 Entry Point: 00000000
6031 Verifying Checksum ... OK
6032 Loading Ramdisk ... OK
6033 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
6034 Boot arguments: root=/dev/ram
6035 time_init: decrementer frequency = 187500000/60
6036 Calibrating delay loop... 49.77 BogoMIPS
6038 RAMDISK: Compressed image found at block 0
6039 VFS: Mounted root (ext2 filesystem).
6043 Boot Linux and pass a flat device tree:
6046 First, U-Boot must be compiled with the appropriate defines. See the section
6047 titled "Linux Kernel Interface" above for a more in depth explanation. The
6048 following is an example of how to start a kernel and pass an updated
6054 oft=oftrees/mpc8540ads.dtb
6055 => tftp $oftaddr $oft
6056 Speed: 1000, full duplex
6058 TFTP from server 192.168.1.1; our IP address is 192.168.1.101
6059 Filename 'oftrees/mpc8540ads.dtb'.
6060 Load address: 0x300000
6063 Bytes transferred = 4106 (100a hex)
6064 => tftp $loadaddr $bootfile
6065 Speed: 1000, full duplex
6067 TFTP from server 192.168.1.1; our IP address is 192.168.1.2
6069 Load address: 0x200000
6070 Loading:############
6072 Bytes transferred = 1029407 (fb51f hex)
6077 => bootm $loadaddr - $oftaddr
6078 ## Booting image at 00200000 ...
6079 Image Name: Linux-2.6.17-dirty
6080 Image Type: PowerPC Linux Kernel Image (gzip compressed)
6081 Data Size: 1029343 Bytes = 1005.2 kB
6082 Load Address: 00000000
6083 Entry Point: 00000000
6084 Verifying Checksum ... OK
6085 Uncompressing Kernel Image ... OK
6086 Booting using flat device tree at 0x300000
6087 Using MPC85xx ADS machine description
6088 Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb
6092 More About U-Boot Image Types:
6093 ------------------------------
6095 U-Boot supports the following image types:
6097 "Standalone Programs" are directly runnable in the environment
6098 provided by U-Boot; it is expected that (if they behave
6099 well) you can continue to work in U-Boot after return from
6100 the Standalone Program.
6101 "OS Kernel Images" are usually images of some Embedded OS which
6102 will take over control completely. Usually these programs
6103 will install their own set of exception handlers, device
6104 drivers, set up the MMU, etc. - this means, that you cannot
6105 expect to re-enter U-Boot except by resetting the CPU.
6106 "RAMDisk Images" are more or less just data blocks, and their
6107 parameters (address, size) are passed to an OS kernel that is
6109 "Multi-File Images" contain several images, typically an OS
6110 (Linux) kernel image and one or more data images like
6111 RAMDisks. This construct is useful for instance when you want
6112 to boot over the network using BOOTP etc., where the boot
6113 server provides just a single image file, but you want to get
6114 for instance an OS kernel and a RAMDisk image.
6116 "Multi-File Images" start with a list of image sizes, each
6117 image size (in bytes) specified by an "uint32_t" in network
6118 byte order. This list is terminated by an "(uint32_t)0".
6119 Immediately after the terminating 0 follow the images, one by
6120 one, all aligned on "uint32_t" boundaries (size rounded up to
6121 a multiple of 4 bytes).
6123 "Firmware Images" are binary images containing firmware (like
6124 U-Boot or FPGA images) which usually will be programmed to
6127 "Script files" are command sequences that will be executed by
6128 U-Boot's command interpreter; this feature is especially
6129 useful when you configure U-Boot to use a real shell (hush)
6130 as command interpreter.
6132 Booting the Linux zImage:
6133 -------------------------
6135 On some platforms, it's possible to boot Linux zImage. This is done
6136 using the "bootz" command. The syntax of "bootz" command is the same
6137 as the syntax of "bootm" command.
6139 Note, defining the CONFIG_SUPPORT_RAW_INITRD allows user to supply
6140 kernel with raw initrd images. The syntax is slightly different, the
6141 address of the initrd must be augmented by it's size, in the following
6142 format: "<initrd addres>:<initrd size>".
6148 One of the features of U-Boot is that you can dynamically load and
6149 run "standalone" applications, which can use some resources of
6150 U-Boot like console I/O functions or interrupt services.
6152 Two simple examples are included with the sources:
6157 'examples/hello_world.c' contains a small "Hello World" Demo
6158 application; it is automatically compiled when you build U-Boot.
6159 It's configured to run at address 0x00040004, so you can play with it
6163 ## Ready for S-Record download ...
6164 ~>examples/hello_world.srec
6165 1 2 3 4 5 6 7 8 9 10 11 ...
6166 [file transfer complete]
6168 ## Start Addr = 0x00040004
6170 => go 40004 Hello World! This is a test.
6171 ## Starting application at 0x00040004 ...
6182 Hit any key to exit ...
6184 ## Application terminated, rc = 0x0
6186 Another example, which demonstrates how to register a CPM interrupt
6187 handler with the U-Boot code, can be found in 'examples/timer.c'.
6188 Here, a CPM timer is set up to generate an interrupt every second.
6189 The interrupt service routine is trivial, just printing a '.'
6190 character, but this is just a demo program. The application can be
6191 controlled by the following keys:
6193 ? - print current values og the CPM Timer registers
6194 b - enable interrupts and start timer
6195 e - stop timer and disable interrupts
6196 q - quit application
6199 ## Ready for S-Record download ...
6200 ~>examples/timer.srec
6201 1 2 3 4 5 6 7 8 9 10 11 ...
6202 [file transfer complete]
6204 ## Start Addr = 0x00040004
6207 ## Starting application at 0x00040004 ...
6210 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
6213 [q, b, e, ?] Set interval 1000000 us
6216 [q, b, e, ?] ........
6217 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
6220 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
6223 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
6226 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
6228 [q, b, e, ?] ...Stopping timer
6230 [q, b, e, ?] ## Application terminated, rc = 0x0
6236 Over time, many people have reported problems when trying to use the
6237 "minicom" terminal emulation program for serial download. I (wd)
6238 consider minicom to be broken, and recommend not to use it. Under
6239 Unix, I recommend to use C-Kermit for general purpose use (and
6240 especially for kermit binary protocol download ("loadb" command), and
6241 use "cu" for S-Record download ("loads" command). See
6242 http://www.denx.de/wiki/view/DULG/SystemSetup#Section_4.3.
6243 for help with kermit.
6246 Nevertheless, if you absolutely want to use it try adding this
6247 configuration to your "File transfer protocols" section:
6249 Name Program Name U/D FullScr IO-Red. Multi
6250 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
6251 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
6257 Starting at version 0.9.2, U-Boot supports NetBSD both as host
6258 (build U-Boot) and target system (boots NetBSD/mpc8xx).
6260 Building requires a cross environment; it is known to work on
6261 NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
6262 need gmake since the Makefiles are not compatible with BSD make).
6263 Note that the cross-powerpc package does not install include files;
6264 attempting to build U-Boot will fail because <machine/ansi.h> is
6265 missing. This file has to be installed and patched manually:
6267 # cd /usr/pkg/cross/powerpc-netbsd/include
6269 # ln -s powerpc machine
6270 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
6271 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
6273 Native builds *don't* work due to incompatibilities between native
6274 and U-Boot include files.
6276 Booting assumes that (the first part of) the image booted is a
6277 stage-2 loader which in turn loads and then invokes the kernel
6278 proper. Loader sources will eventually appear in the NetBSD source
6279 tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
6280 meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz
6283 Implementation Internals:
6284 =========================
6286 The following is not intended to be a complete description of every
6287 implementation detail. However, it should help to understand the
6288 inner workings of U-Boot and make it easier to port it to custom
6292 Initial Stack, Global Data:
6293 ---------------------------
6295 The implementation of U-Boot is complicated by the fact that U-Boot
6296 starts running out of ROM (flash memory), usually without access to
6297 system RAM (because the memory controller is not initialized yet).
6298 This means that we don't have writable Data or BSS segments, and BSS
6299 is not initialized as zero. To be able to get a C environment working
6300 at all, we have to allocate at least a minimal stack. Implementation
6301 options for this are defined and restricted by the CPU used: Some CPU
6302 models provide on-chip memory (like the IMMR area on MPC8xx and
6303 MPC826x processors), on others (parts of) the data cache can be
6304 locked as (mis-) used as memory, etc.
6306 Chris Hallinan posted a good summary of these issues to the
6307 U-Boot mailing list:
6309 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
6310 From: "Chris Hallinan" <clh@net1plus.com>
6311 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
6314 Correct me if I'm wrong, folks, but the way I understand it
6315 is this: Using DCACHE as initial RAM for Stack, etc, does not
6316 require any physical RAM backing up the cache. The cleverness
6317 is that the cache is being used as a temporary supply of
6318 necessary storage before the SDRAM controller is setup. It's
6319 beyond the scope of this list to explain the details, but you
6320 can see how this works by studying the cache architecture and
6321 operation in the architecture and processor-specific manuals.
6323 OCM is On Chip Memory, which I believe the 405GP has 4K. It
6324 is another option for the system designer to use as an
6325 initial stack/RAM area prior to SDRAM being available. Either
6326 option should work for you. Using CS 4 should be fine if your
6327 board designers haven't used it for something that would
6328 cause you grief during the initial boot! It is frequently not
6331 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere
6332 with your processor/board/system design. The default value
6333 you will find in any recent u-boot distribution in
6334 walnut.h should work for you. I'd set it to a value larger
6335 than your SDRAM module. If you have a 64MB SDRAM module, set
6336 it above 400_0000. Just make sure your board has no resources
6337 that are supposed to respond to that address! That code in
6338 start.S has been around a while and should work as is when
6339 you get the config right.
6344 It is essential to remember this, since it has some impact on the C
6345 code for the initialization procedures:
6347 * Initialized global data (data segment) is read-only. Do not attempt
6350 * Do not use any uninitialized global data (or implicitly initialized
6351 as zero data - BSS segment) at all - this is undefined, initiali-
6352 zation is performed later (when relocating to RAM).
6354 * Stack space is very limited. Avoid big data buffers or things like
6357 Having only the stack as writable memory limits means we cannot use
6358 normal global data to share information between the code. But it
6359 turned out that the implementation of U-Boot can be greatly
6360 simplified by making a global data structure (gd_t) available to all
6361 functions. We could pass a pointer to this data as argument to _all_
6362 functions, but this would bloat the code. Instead we use a feature of
6363 the GCC compiler (Global Register Variables) to share the data: we
6364 place a pointer (gd) to the global data into a register which we
6365 reserve for this purpose.
6367 When choosing a register for such a purpose we are restricted by the
6368 relevant (E)ABI specifications for the current architecture, and by
6369 GCC's implementation.
6371 For PowerPC, the following registers have specific use:
6373 R2: reserved for system use
6374 R3-R4: parameter passing and return values
6375 R5-R10: parameter passing
6376 R13: small data area pointer
6380 (U-Boot also uses R12 as internal GOT pointer. r12
6381 is a volatile register so r12 needs to be reset when
6382 going back and forth between asm and C)
6384 ==> U-Boot will use R2 to hold a pointer to the global data
6386 Note: on PPC, we could use a static initializer (since the
6387 address of the global data structure is known at compile time),
6388 but it turned out that reserving a register results in somewhat
6389 smaller code - although the code savings are not that big (on
6390 average for all boards 752 bytes for the whole U-Boot image,
6391 624 text + 127 data).
6393 On Blackfin, the normal C ABI (except for P3) is followed as documented here:
6394 http://docs.blackfin.uclinux.org/doku.php?id=application_binary_interface
6396 ==> U-Boot will use P3 to hold a pointer to the global data
6398 On ARM, the following registers are used:
6400 R0: function argument word/integer result
6401 R1-R3: function argument word
6402 R9: platform specific
6403 R10: stack limit (used only if stack checking is enabled)
6404 R11: argument (frame) pointer
6405 R12: temporary workspace
6408 R15: program counter
6410 ==> U-Boot will use R9 to hold a pointer to the global data
6412 Note: on ARM, only R_ARM_RELATIVE relocations are supported.
6414 On Nios II, the ABI is documented here:
6415 http://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf
6417 ==> U-Boot will use gp to hold a pointer to the global data
6419 Note: on Nios II, we give "-G0" option to gcc and don't use gp
6420 to access small data sections, so gp is free.
6422 On NDS32, the following registers are used:
6424 R0-R1: argument/return
6426 R15: temporary register for assembler
6427 R16: trampoline register
6428 R28: frame pointer (FP)
6429 R29: global pointer (GP)
6430 R30: link register (LP)
6431 R31: stack pointer (SP)
6432 PC: program counter (PC)
6434 ==> U-Boot will use R10 to hold a pointer to the global data
6436 NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope,
6437 or current versions of GCC may "optimize" the code too much.
6442 U-Boot runs in system state and uses physical addresses, i.e. the
6443 MMU is not used either for address mapping nor for memory protection.
6445 The available memory is mapped to fixed addresses using the memory
6446 controller. In this process, a contiguous block is formed for each
6447 memory type (Flash, SDRAM, SRAM), even when it consists of several
6448 physical memory banks.
6450 U-Boot is installed in the first 128 kB of the first Flash bank (on
6451 TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
6452 booting and sizing and initializing DRAM, the code relocates itself
6453 to the upper end of DRAM. Immediately below the U-Boot code some
6454 memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN
6455 configuration setting]. Below that, a structure with global Board
6456 Info data is placed, followed by the stack (growing downward).
6458 Additionally, some exception handler code is copied to the low 8 kB
6459 of DRAM (0x00000000 ... 0x00001FFF).
6461 So a typical memory configuration with 16 MB of DRAM could look like
6464 0x0000 0000 Exception Vector code
6467 0x0000 2000 Free for Application Use
6473 0x00FB FF20 Monitor Stack (Growing downward)
6474 0x00FB FFAC Board Info Data and permanent copy of global data
6475 0x00FC 0000 Malloc Arena
6478 0x00FE 0000 RAM Copy of Monitor Code
6479 ... eventually: LCD or video framebuffer
6480 ... eventually: pRAM (Protected RAM - unchanged by reset)
6481 0x00FF FFFF [End of RAM]
6484 System Initialization:
6485 ----------------------
6487 In the reset configuration, U-Boot starts at the reset entry point
6488 (on most PowerPC systems at address 0x00000100). Because of the reset
6489 configuration for CS0# this is a mirror of the on board Flash memory.
6490 To be able to re-map memory U-Boot then jumps to its link address.
6491 To be able to implement the initialization code in C, a (small!)
6492 initial stack is set up in the internal Dual Ported RAM (in case CPUs
6493 which provide such a feature like MPC8xx or MPC8260), or in a locked
6494 part of the data cache. After that, U-Boot initializes the CPU core,
6495 the caches and the SIU.
6497 Next, all (potentially) available memory banks are mapped using a
6498 preliminary mapping. For example, we put them on 512 MB boundaries
6499 (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
6500 on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
6501 programmed for SDRAM access. Using the temporary configuration, a
6502 simple memory test is run that determines the size of the SDRAM
6505 When there is more than one SDRAM bank, and the banks are of
6506 different size, the largest is mapped first. For equal size, the first
6507 bank (CS2#) is mapped first. The first mapping is always for address
6508 0x00000000, with any additional banks following immediately to create
6509 contiguous memory starting from 0.
6511 Then, the monitor installs itself at the upper end of the SDRAM area
6512 and allocates memory for use by malloc() and for the global Board
6513 Info data; also, the exception vector code is copied to the low RAM
6514 pages, and the final stack is set up.
6516 Only after this relocation will you have a "normal" C environment;
6517 until that you are restricted in several ways, mostly because you are
6518 running from ROM, and because the code will have to be relocated to a
6522 U-Boot Porting Guide:
6523 ----------------------
6525 [Based on messages by Jerry Van Baren in the U-Boot-Users mailing
6529 int main(int argc, char *argv[])
6531 sighandler_t no_more_time;
6533 signal(SIGALRM, no_more_time);
6534 alarm(PROJECT_DEADLINE - toSec (3 * WEEK));
6536 if (available_money > available_manpower) {
6537 Pay consultant to port U-Boot;
6541 Download latest U-Boot source;
6543 Subscribe to u-boot mailing list;
6546 email("Hi, I am new to U-Boot, how do I get started?");
6549 Read the README file in the top level directory;
6550 Read http://www.denx.de/twiki/bin/view/DULG/Manual;
6551 Read applicable doc/*.README;
6552 Read the source, Luke;
6553 /* find . -name "*.[chS]" | xargs grep -i <keyword> */
6556 if (available_money > toLocalCurrency ($2500))
6559 Add a lot of aggravation and time;
6561 if (a similar board exists) { /* hopefully... */
6562 cp -a board/<similar> board/<myboard>
6563 cp include/configs/<similar>.h include/configs/<myboard>.h
6565 Create your own board support subdirectory;
6566 Create your own board include/configs/<myboard>.h file;
6568 Edit new board/<myboard> files
6569 Edit new include/configs/<myboard>.h
6574 Add / modify source code;
6578 email("Hi, I am having problems...");
6580 Send patch file to the U-Boot email list;
6581 if (reasonable critiques)
6582 Incorporate improvements from email list code review;
6584 Defend code as written;
6590 void no_more_time (int sig)
6599 All contributions to U-Boot should conform to the Linux kernel
6600 coding style; see the file "Documentation/CodingStyle" and the script
6601 "scripts/Lindent" in your Linux kernel source directory.
6603 Source files originating from a different project (for example the
6604 MTD subsystem) are generally exempt from these guidelines and are not
6605 reformatted to ease subsequent migration to newer versions of those
6608 Please note that U-Boot is implemented in C (and to some small parts in
6609 Assembler); no C++ is used, so please do not use C++ style comments (//)
6612 Please also stick to the following formatting rules:
6613 - remove any trailing white space
6614 - use TAB characters for indentation and vertical alignment, not spaces
6615 - make sure NOT to use DOS '\r\n' line feeds
6616 - do not add more than 2 consecutive empty lines to source files
6617 - do not add trailing empty lines to source files
6619 Submissions which do not conform to the standards may be returned
6620 with a request to reformat the changes.
6626 Since the number of patches for U-Boot is growing, we need to
6627 establish some rules. Submissions which do not conform to these rules
6628 may be rejected, even when they contain important and valuable stuff.
6630 Please see http://www.denx.de/wiki/U-Boot/Patches for details.
6632 Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>;
6633 see http://lists.denx.de/mailman/listinfo/u-boot
6635 When you send a patch, please include the following information with
6638 * For bug fixes: a description of the bug and how your patch fixes
6639 this bug. Please try to include a way of demonstrating that the
6640 patch actually fixes something.
6642 * For new features: a description of the feature and your
6645 * A CHANGELOG entry as plaintext (separate from the patch)
6647 * For major contributions, your entry to the CREDITS file
6649 * When you add support for a new board, don't forget to add a
6650 maintainer e-mail address to the boards.cfg file, too.
6652 * If your patch adds new configuration options, don't forget to
6653 document these in the README file.
6655 * The patch itself. If you are using git (which is *strongly*
6656 recommended) you can easily generate the patch using the
6657 "git format-patch". If you then use "git send-email" to send it to
6658 the U-Boot mailing list, you will avoid most of the common problems
6659 with some other mail clients.
6661 If you cannot use git, use "diff -purN OLD NEW". If your version of
6662 diff does not support these options, then get the latest version of
6665 The current directory when running this command shall be the parent
6666 directory of the U-Boot source tree (i. e. please make sure that
6667 your patch includes sufficient directory information for the
6670 We prefer patches as plain text. MIME attachments are discouraged,
6671 and compressed attachments must not be used.
6673 * If one logical set of modifications affects or creates several
6674 files, all these changes shall be submitted in a SINGLE patch file.
6676 * Changesets that contain different, unrelated modifications shall be
6677 submitted as SEPARATE patches, one patch per changeset.
6682 * Before sending the patch, run the MAKEALL script on your patched
6683 source tree and make sure that no errors or warnings are reported
6684 for any of the boards.
6686 * Keep your modifications to the necessary minimum: A patch
6687 containing several unrelated changes or arbitrary reformats will be
6688 returned with a request to re-formatting / split it.
6690 * If you modify existing code, make sure that your new code does not
6691 add to the memory footprint of the code ;-) Small is beautiful!
6692 When adding new features, these should compile conditionally only
6693 (using #ifdef), and the resulting code with the new feature
6694 disabled must not need more memory than the old code without your
6697 * Remember that there is a size limit of 100 kB per message on the
6698 u-boot mailing list. Bigger patches will be moderated. If they are
6699 reasonable and not too big, they will be acknowledged. But patches
6700 bigger than the size limit should be avoided.
projects / platform / kernel / u-boot.git / blob