2 # (C) Copyright 2000 - 2013
3 # Wolfgang Denk, DENX Software Engineering, wd@denx.de.
5 # SPDX-License-Identifier: GPL-2.0+
11 This directory contains the source code for U-Boot, a boot loader for
12 Embedded boards based on PowerPC, ARM, MIPS and several other
13 processors, which can be installed in a boot ROM and used to
14 initialize and test the hardware or to download and run application
17 The development of U-Boot is closely related to Linux: some parts of
18 the source code originate in the Linux source tree, we have some
19 header files in common, and special provision has been made to
20 support booting of Linux images.
22 Some attention has been paid to make this software easily
23 configurable and extendable. For instance, all monitor commands are
24 implemented with the same call interface, so that it's very easy to
25 add new commands. Also, instead of permanently adding rarely used
26 code (for instance hardware test utilities) to the monitor, you can
27 load and run it dynamically.
33 In general, all boards for which a configuration option exists in the
34 Makefile have been tested to some extent and can be considered
35 "working". In fact, many of them are used in production systems.
37 In case of problems see the CHANGELOG and CREDITS files to find out
38 who contributed the specific port. The boards.cfg file lists board
41 Note: There is no CHANGELOG file in the actual U-Boot source tree;
42 it can be created dynamically from the Git log using:
50 In case you have questions about, problems with or contributions for
51 U-Boot you should send a message to the U-Boot mailing list at
52 <u-boot@lists.denx.de>. There is also an archive of previous traffic
53 on the mailing list - please search the archive before asking FAQ's.
54 Please see http://lists.denx.de/pipermail/u-boot and
55 http://dir.gmane.org/gmane.comp.boot-loaders.u-boot
58 Where to get source code:
59 =========================
61 The U-Boot source code is maintained in the git repository at
62 git://www.denx.de/git/u-boot.git ; you can browse it online at
63 http://www.denx.de/cgi-bin/gitweb.cgi?p=u-boot.git;a=summary
65 The "snapshot" links on this page allow you to download tarballs of
66 any version you might be interested in. Official releases are also
67 available for FTP download from the ftp://ftp.denx.de/pub/u-boot/
70 Pre-built (and tested) images are available from
71 ftp://ftp.denx.de/pub/u-boot/images/
77 - start from 8xxrom sources
78 - create PPCBoot project (http://sourceforge.net/projects/ppcboot)
80 - make it easier to add custom boards
81 - make it possible to add other [PowerPC] CPUs
82 - extend functions, especially:
83 * Provide extended interface to Linux boot loader
86 * PCMCIA / CompactFlash / ATA disk / SCSI ... boot
87 - create ARMBoot project (http://sourceforge.net/projects/armboot)
88 - add other CPU families (starting with ARM)
89 - create U-Boot project (http://sourceforge.net/projects/u-boot)
90 - current project page: see http://www.denx.de/wiki/U-Boot
96 The "official" name of this project is "Das U-Boot". The spelling
97 "U-Boot" shall be used in all written text (documentation, comments
98 in source files etc.). Example:
100 This is the README file for the U-Boot project.
102 File names etc. shall be based on the string "u-boot". Examples:
104 include/asm-ppc/u-boot.h
106 #include <asm/u-boot.h>
108 Variable names, preprocessor constants etc. shall be either based on
109 the string "u_boot" or on "U_BOOT". Example:
111 U_BOOT_VERSION u_boot_logo
112 IH_OS_U_BOOT u_boot_hush_start
118 Starting with the release in October 2008, the names of the releases
119 were changed from numerical release numbers without deeper meaning
120 into a time stamp based numbering. Regular releases are identified by
121 names consisting of the calendar year and month of the release date.
122 Additional fields (if present) indicate release candidates or bug fix
123 releases in "stable" maintenance trees.
126 U-Boot v2009.11 - Release November 2009
127 U-Boot v2009.11.1 - Release 1 in version November 2009 stable tree
128 U-Boot v2010.09-rc1 - Release candiate 1 for September 2010 release
134 /arch Architecture specific files
135 /arc Files generic to ARC architecture
136 /cpu CPU specific files
137 /arc700 Files specific to ARC 700 CPUs
138 /lib Architecture specific library files
139 /arm Files generic to ARM architecture
140 /cpu CPU specific files
141 /arm720t Files specific to ARM 720 CPUs
142 /arm920t Files specific to ARM 920 CPUs
143 /at91 Files specific to Atmel AT91RM9200 CPU
144 /imx Files specific to Freescale MC9328 i.MX CPUs
145 /s3c24x0 Files specific to Samsung S3C24X0 CPUs
146 /arm926ejs Files specific to ARM 926 CPUs
147 /arm1136 Files specific to ARM 1136 CPUs
148 /pxa Files specific to Intel XScale PXA CPUs
149 /sa1100 Files specific to Intel StrongARM SA1100 CPUs
150 /lib Architecture specific library files
151 /avr32 Files generic to AVR32 architecture
152 /cpu CPU specific files
153 /lib Architecture specific library files
154 /blackfin Files generic to Analog Devices Blackfin architecture
155 /cpu CPU specific files
156 /lib Architecture specific library files
157 /m68k Files generic to m68k architecture
158 /cpu CPU specific files
159 /mcf52x2 Files specific to Freescale ColdFire MCF52x2 CPUs
160 /mcf5227x Files specific to Freescale ColdFire MCF5227x CPUs
161 /mcf532x Files specific to Freescale ColdFire MCF5329 CPUs
162 /mcf5445x Files specific to Freescale ColdFire MCF5445x CPUs
163 /mcf547x_8x Files specific to Freescale ColdFire MCF547x_8x CPUs
164 /lib Architecture specific library files
165 /microblaze Files generic to microblaze architecture
166 /cpu CPU specific files
167 /lib Architecture specific library files
168 /mips Files generic to MIPS architecture
169 /cpu CPU specific files
170 /mips32 Files specific to MIPS32 CPUs
171 /mips64 Files specific to MIPS64 CPUs
172 /lib Architecture specific library files
173 /nds32 Files generic to NDS32 architecture
174 /cpu CPU specific files
175 /n1213 Files specific to Andes Technology N1213 CPUs
176 /lib Architecture specific library files
177 /nios2 Files generic to Altera NIOS2 architecture
178 /cpu CPU specific files
179 /lib Architecture specific library files
180 /openrisc Files generic to OpenRISC architecture
181 /cpu CPU specific files
182 /lib Architecture specific library files
183 /powerpc Files generic to PowerPC architecture
184 /cpu CPU specific files
185 /mpc5xx Files specific to Freescale MPC5xx CPUs
186 /mpc5xxx Files specific to Freescale MPC5xxx CPUs
187 /mpc8xx Files specific to Freescale MPC8xx CPUs
188 /mpc8260 Files specific to Freescale MPC8260 CPUs
189 /mpc85xx Files specific to Freescale MPC85xx CPUs
190 /ppc4xx Files specific to AMCC PowerPC 4xx CPUs
191 /lib Architecture specific library files
192 /sh Files generic to SH architecture
193 /cpu CPU specific files
194 /sh2 Files specific to sh2 CPUs
195 /sh3 Files specific to sh3 CPUs
196 /sh4 Files specific to sh4 CPUs
197 /lib Architecture specific library files
198 /sparc Files generic to SPARC architecture
199 /cpu CPU specific files
200 /leon2 Files specific to Gaisler LEON2 SPARC CPU
201 /leon3 Files specific to Gaisler LEON3 SPARC CPU
202 /lib Architecture specific library files
203 /x86 Files generic to x86 architecture
204 /cpu CPU specific files
205 /lib Architecture specific library files
206 /api Machine/arch independent API for external apps
207 /board Board dependent files
208 /common Misc architecture independent functions
209 /disk Code for disk drive partition handling
210 /doc Documentation (don't expect too much)
211 /drivers Commonly used device drivers
212 /dts Contains Makefile for building internal U-Boot fdt.
213 /examples Example code for standalone applications, etc.
214 /fs Filesystem code (cramfs, ext2, jffs2, etc.)
215 /include Header Files
216 /lib Files generic to all architectures
217 /libfdt Library files to support flattened device trees
218 /lzma Library files to support LZMA decompression
219 /lzo Library files to support LZO decompression
221 /post Power On Self Test
222 /spl Secondary Program Loader framework
223 /tools Tools to build S-Record or U-Boot images, etc.
225 Software Configuration:
226 =======================
228 Configuration is usually done using C preprocessor defines; the
229 rationale behind that is to avoid dead code whenever possible.
231 There are two classes of configuration variables:
233 * Configuration _OPTIONS_:
234 These are selectable by the user and have names beginning with
237 * Configuration _SETTINGS_:
238 These depend on the hardware etc. and should not be meddled with if
239 you don't know what you're doing; they have names beginning with
242 Later we will add a configuration tool - probably similar to or even
243 identical to what's used for the Linux kernel. Right now, we have to
244 do the configuration by hand, which means creating some symbolic
245 links and editing some configuration files. We use the TQM8xxL boards
249 Selection of Processor Architecture and Board Type:
250 ---------------------------------------------------
252 For all supported boards there are ready-to-use default
253 configurations available; just type "make <board_name>_defconfig".
255 Example: For a TQM823L module type:
258 make TQM823L_defconfig
260 For the Cogent platform, you need to specify the CPU type as well;
261 e.g. "make cogent_mpc8xx_defconfig". And also configure the cogent
262 directory according to the instructions in cogent/README.
268 U-Boot can be built natively to run on a Linux host using the 'sandbox'
269 board. This allows feature development which is not board- or architecture-
270 specific to be undertaken on a native platform. The sandbox is also used to
271 run some of U-Boot's tests.
273 See board/sandbox/README.sandbox for more details.
276 Board Initialisation Flow:
277 --------------------------
279 This is the intended start-up flow for boards. This should apply for both
280 SPL and U-Boot proper (i.e. they both follow the same rules). At present SPL
281 mostly uses a separate code path, but the funtion names and roles of each
282 function are the same. Some boards or architectures may not conform to this.
283 At least most ARM boards which use CONFIG_SPL_FRAMEWORK conform to this.
285 Execution starts with start.S with three functions called during init after
286 that. The purpose and limitations of each is described below.
289 - purpose: essential init to permit execution to reach board_init_f()
290 - no global_data or BSS
291 - there is no stack (ARMv7 may have one but it will soon be removed)
292 - must not set up SDRAM or use console
293 - must only do the bare minimum to allow execution to continue to
295 - this is almost never needed
296 - return normally from this function
299 - purpose: set up the machine ready for running board_init_r():
300 i.e. SDRAM and serial UART
301 - global_data is available
303 - BSS is not available, so you cannot use global/static variables,
304 only stack variables and global_data
306 Non-SPL-specific notes:
307 - dram_init() is called to set up DRAM. If already done in SPL this
311 - you can override the entire board_init_f() function with your own
313 - preloader_console_init() can be called here in extremis
314 - should set up SDRAM, and anything needed to make the UART work
315 - these is no need to clear BSS, it will be done by crt0.S
316 - must return normally from this function (don't call board_init_r()
319 Here the BSS is cleared. For SPL, if CONFIG_SPL_STACK_R is defined, then at
320 this point the stack and global_data are relocated to below
321 CONFIG_SPL_STACK_R_ADDR. For non-SPL, U-Boot is relocated to run at the top of
325 - purpose: main execution, common code
326 - global_data is available
328 - BSS is available, all static/global variables can be used
329 - execution eventually continues to main_loop()
331 Non-SPL-specific notes:
332 - U-Boot is relocated to the top of memory and is now running from
336 - stack is optionally in SDRAM, if CONFIG_SPL_STACK_R is defined and
337 CONFIG_SPL_STACK_R_ADDR points into SDRAM
338 - preloader_console_init() can be called here - typically this is
339 done by defining CONFIG_SPL_BOARD_INIT and then supplying a
340 spl_board_init() function containing this call
341 - loads U-Boot or (in falcon mode) Linux
345 Configuration Options:
346 ----------------------
348 Configuration depends on the combination of board and CPU type; all
349 such information is kept in a configuration file
350 "include/configs/<board_name>.h".
352 Example: For a TQM823L module, all configuration settings are in
353 "include/configs/TQM823L.h".
356 Many of the options are named exactly as the corresponding Linux
357 kernel configuration options. The intention is to make it easier to
358 build a config tool - later.
361 The following options need to be configured:
363 - CPU Type: Define exactly one, e.g. CONFIG_MPC85XX.
365 - Board Type: Define exactly one, e.g. CONFIG_MPC8540ADS.
367 - CPU Daughterboard Type: (if CONFIG_ATSTK1000 is defined)
368 Define exactly one, e.g. CONFIG_ATSTK1002
370 - CPU Module Type: (if CONFIG_COGENT is defined)
371 Define exactly one of
373 --- FIXME --- not tested yet:
374 CONFIG_CMA286_60, CONFIG_CMA286_21, CONFIG_CMA286_60P,
375 CONFIG_CMA287_23, CONFIG_CMA287_50
377 - Motherboard Type: (if CONFIG_COGENT is defined)
378 Define exactly one of
379 CONFIG_CMA101, CONFIG_CMA102
381 - Motherboard I/O Modules: (if CONFIG_COGENT is defined)
382 Define one or more of
385 - Motherboard Options: (if CONFIG_CMA101 or CONFIG_CMA102 are defined)
386 Define one or more of
387 CONFIG_LCD_HEARTBEAT - update a character position on
388 the LCD display every second with
391 - Marvell Family Member
392 CONFIG_SYS_MVFS - define it if you want to enable
393 multiple fs option at one time
394 for marvell soc family
396 - 8xx CPU Options: (if using an MPC8xx CPU)
397 CONFIG_8xx_GCLK_FREQ - deprecated: CPU clock if
398 get_gclk_freq() cannot work
399 e.g. if there is no 32KHz
400 reference PIT/RTC clock
401 CONFIG_8xx_OSCLK - PLL input clock (either EXTCLK
404 - 859/866/885 CPU options: (if using a MPC859 or MPC866 or MPC885 CPU):
405 CONFIG_SYS_8xx_CPUCLK_MIN
406 CONFIG_SYS_8xx_CPUCLK_MAX
407 CONFIG_8xx_CPUCLK_DEFAULT
408 See doc/README.MPC866
410 CONFIG_SYS_MEASURE_CPUCLK
412 Define this to measure the actual CPU clock instead
413 of relying on the correctness of the configured
414 values. Mostly useful for board bringup to make sure
415 the PLL is locked at the intended frequency. Note
416 that this requires a (stable) reference clock (32 kHz
417 RTC clock or CONFIG_SYS_8XX_XIN)
419 CONFIG_SYS_DELAYED_ICACHE
421 Define this option if you want to enable the
422 ICache only when Code runs from RAM.
427 Specifies that the core is a 64-bit PowerPC implementation (implements
428 the "64" category of the Power ISA). This is necessary for ePAPR
429 compliance, among other possible reasons.
431 CONFIG_SYS_FSL_TBCLK_DIV
433 Defines the core time base clock divider ratio compared to the
434 system clock. On most PQ3 devices this is 8, on newer QorIQ
435 devices it can be 16 or 32. The ratio varies from SoC to Soc.
437 CONFIG_SYS_FSL_PCIE_COMPAT
439 Defines the string to utilize when trying to match PCIe device
440 tree nodes for the given platform.
442 CONFIG_SYS_PPC_E500_DEBUG_TLB
444 Enables a temporary TLB entry to be used during boot to work
445 around limitations in e500v1 and e500v2 external debugger
446 support. This reduces the portions of the boot code where
447 breakpoints and single stepping do not work. The value of this
448 symbol should be set to the TLB1 entry to be used for this
451 CONFIG_SYS_FSL_ERRATUM_A004510
453 Enables a workaround for erratum A004510. If set,
454 then CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV and
455 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY must be set.
457 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV
458 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV2 (optional)
460 Defines one or two SoC revisions (low 8 bits of SVR)
461 for which the A004510 workaround should be applied.
463 The rest of SVR is either not relevant to the decision
464 of whether the erratum is present (e.g. p2040 versus
465 p2041) or is implied by the build target, which controls
466 whether CONFIG_SYS_FSL_ERRATUM_A004510 is set.
468 See Freescale App Note 4493 for more information about
471 CONFIG_A003399_NOR_WORKAROUND
472 Enables a workaround for IFC erratum A003399. It is only
473 required during NOR boot.
475 CONFIG_A008044_WORKAROUND
476 Enables a workaround for T1040/T1042 erratum A008044. It is only
477 required during NAND boot and valid for Rev 1.0 SoC revision
479 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY
481 This is the value to write into CCSR offset 0x18600
482 according to the A004510 workaround.
484 CONFIG_SYS_FSL_DSP_DDR_ADDR
485 This value denotes start offset of DDR memory which is
486 connected exclusively to the DSP cores.
488 CONFIG_SYS_FSL_DSP_M2_RAM_ADDR
489 This value denotes start offset of M2 memory
490 which is directly connected to the DSP core.
492 CONFIG_SYS_FSL_DSP_M3_RAM_ADDR
493 This value denotes start offset of M3 memory which is directly
494 connected to the DSP core.
496 CONFIG_SYS_FSL_DSP_CCSRBAR_DEFAULT
497 This value denotes start offset of DSP CCSR space.
499 CONFIG_SYS_FSL_SINGLE_SOURCE_CLK
500 Single Source Clock is clocking mode present in some of FSL SoC's.
501 In this mode, a single differential clock is used to supply
502 clocks to the sysclock, ddrclock and usbclock.
504 CONFIG_SYS_CPC_REINIT_F
505 This CONFIG is defined when the CPC is configured as SRAM at the
506 time of U-boot entry and is required to be re-initialized.
509 Indicates this SoC supports deep sleep feature. If deep sleep is
510 supported, core will start to execute uboot when wakes up.
512 - Generic CPU options:
513 CONFIG_SYS_GENERIC_GLOBAL_DATA
514 Defines global data is initialized in generic board board_init_f().
515 If this macro is defined, global data is created and cleared in
516 generic board board_init_f(). Without this macro, architecture/board
517 should initialize global data before calling board_init_f().
519 CONFIG_SYS_BIG_ENDIAN, CONFIG_SYS_LITTLE_ENDIAN
521 Defines the endianess of the CPU. Implementation of those
522 values is arch specific.
525 Freescale DDR driver in use. This type of DDR controller is
526 found in mpc83xx, mpc85xx, mpc86xx as well as some ARM core
529 CONFIG_SYS_FSL_DDR_ADDR
530 Freescale DDR memory-mapped register base.
532 CONFIG_SYS_FSL_DDR_EMU
533 Specify emulator support for DDR. Some DDR features such as
534 deskew training are not available.
536 CONFIG_SYS_FSL_DDRC_GEN1
537 Freescale DDR1 controller.
539 CONFIG_SYS_FSL_DDRC_GEN2
540 Freescale DDR2 controller.
542 CONFIG_SYS_FSL_DDRC_GEN3
543 Freescale DDR3 controller.
545 CONFIG_SYS_FSL_DDRC_GEN4
546 Freescale DDR4 controller.
548 CONFIG_SYS_FSL_DDRC_ARM_GEN3
549 Freescale DDR3 controller for ARM-based SoCs.
552 Board config to use DDR1. It can be enabled for SoCs with
553 Freescale DDR1 or DDR2 controllers, depending on the board
557 Board config to use DDR2. It can be eanbeld for SoCs with
558 Freescale DDR2 or DDR3 controllers, depending on the board
562 Board config to use DDR3. It can be enabled for SoCs with
563 Freescale DDR3 or DDR3L controllers.
566 Board config to use DDR3L. It can be enabled for SoCs with
570 Board config to use DDR4. It can be enabled for SoCs with
573 CONFIG_SYS_FSL_IFC_BE
574 Defines the IFC controller register space as Big Endian
576 CONFIG_SYS_FSL_IFC_LE
577 Defines the IFC controller register space as Little Endian
579 CONFIG_SYS_FSL_PBL_PBI
580 It enables addition of RCW (Power on reset configuration) in built image.
581 Please refer doc/README.pblimage for more details
583 CONFIG_SYS_FSL_PBL_RCW
584 It adds PBI(pre-boot instructions) commands in u-boot build image.
585 PBI commands can be used to configure SoC before it starts the execution.
586 Please refer doc/README.pblimage for more details
589 It adds a target to create boot binary having SPL binary in PBI format
590 concatenated with u-boot binary.
592 CONFIG_SYS_FSL_DDR_BE
593 Defines the DDR controller register space as Big Endian
595 CONFIG_SYS_FSL_DDR_LE
596 Defines the DDR controller register space as Little Endian
598 CONFIG_SYS_FSL_DDR_SDRAM_BASE_PHY
599 Physical address from the view of DDR controllers. It is the
600 same as CONFIG_SYS_DDR_SDRAM_BASE for all Power SoCs. But
601 it could be different for ARM SoCs.
603 CONFIG_SYS_FSL_DDR_INTLV_256B
604 DDR controller interleaving on 256-byte. This is a special
605 interleaving mode, handled by Dickens for Freescale layerscape
608 CONFIG_SYS_FSL_DDR_MAIN_NUM_CTRLS
609 Number of controllers used as main memory.
611 CONFIG_SYS_FSL_OTHER_DDR_NUM_CTRLS
612 Number of controllers used for other than main memory.
614 CONFIG_SYS_FSL_SEC_BE
615 Defines the SEC controller register space as Big Endian
617 CONFIG_SYS_FSL_SEC_LE
618 Defines the SEC controller register space as Little Endian
620 - Intel Monahans options:
621 CONFIG_SYS_MONAHANS_RUN_MODE_OSC_RATIO
623 Defines the Monahans run mode to oscillator
624 ratio. Valid values are 8, 16, 24, 31. The core
625 frequency is this value multiplied by 13 MHz.
627 CONFIG_SYS_MONAHANS_TURBO_RUN_MODE_RATIO
629 Defines the Monahans turbo mode to oscillator
630 ratio. Valid values are 1 (default if undefined) and
631 2. The core frequency as calculated above is multiplied
635 CONFIG_SYS_INIT_SP_OFFSET
637 Offset relative to CONFIG_SYS_SDRAM_BASE for initial stack
638 pointer. This is needed for the temporary stack before
641 CONFIG_SYS_MIPS_CACHE_MODE
643 Cache operation mode for the MIPS CPU.
644 See also arch/mips/include/asm/mipsregs.h.
646 CONF_CM_CACHABLE_NO_WA
649 CONF_CM_CACHABLE_NONCOHERENT
653 CONF_CM_CACHABLE_ACCELERATED
655 CONFIG_SYS_XWAY_EBU_BOOTCFG
657 Special option for Lantiq XWAY SoCs for booting from NOR flash.
658 See also arch/mips/cpu/mips32/start.S.
660 CONFIG_XWAY_SWAP_BYTES
662 Enable compilation of tools/xway-swap-bytes needed for Lantiq
663 XWAY SoCs for booting from NOR flash. The U-Boot image needs to
664 be swapped if a flash programmer is used.
667 CONFIG_SYS_EXCEPTION_VECTORS_HIGH
669 Select high exception vectors of the ARM core, e.g., do not
670 clear the V bit of the c1 register of CP15.
672 CONFIG_SYS_THUMB_BUILD
674 Use this flag to build U-Boot using the Thumb instruction
675 set for ARM architectures. Thumb instruction set provides
676 better code density. For ARM architectures that support
677 Thumb2 this flag will result in Thumb2 code generated by
680 CONFIG_ARM_ERRATA_716044
681 CONFIG_ARM_ERRATA_742230
682 CONFIG_ARM_ERRATA_743622
683 CONFIG_ARM_ERRATA_751472
684 CONFIG_ARM_ERRATA_794072
685 CONFIG_ARM_ERRATA_761320
687 If set, the workarounds for these ARM errata are applied early
688 during U-Boot startup. Note that these options force the
689 workarounds to be applied; no CPU-type/version detection
690 exists, unlike the similar options in the Linux kernel. Do not
691 set these options unless they apply!
693 NOTE: The following can be machine specific errata. These
694 do have ability to provide rudimentary version and machine
695 specific checks, but expect no product checks.
696 CONFIG_ARM_ERRATA_454179
697 CONFIG_ARM_ERRATA_798870
700 CONFIG_TEGRA_SUPPORT_NON_SECURE
702 Support executing U-Boot in non-secure (NS) mode. Certain
703 impossible actions will be skipped if the CPU is in NS mode,
704 such as ARM architectural timer initialization.
707 - Linux Kernel Interface:
710 U-Boot stores all clock information in Hz
711 internally. For binary compatibility with older Linux
712 kernels (which expect the clocks passed in the
713 bd_info data to be in MHz) the environment variable
714 "clocks_in_mhz" can be defined so that U-Boot
715 converts clock data to MHZ before passing it to the
717 When CONFIG_CLOCKS_IN_MHZ is defined, a definition of
718 "clocks_in_mhz=1" is automatically included in the
721 CONFIG_MEMSIZE_IN_BYTES [relevant for MIPS only]
723 When transferring memsize parameter to Linux, some versions
724 expect it to be in bytes, others in MB.
725 Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes.
729 New kernel versions are expecting firmware settings to be
730 passed using flattened device trees (based on open firmware
734 * New libfdt-based support
735 * Adds the "fdt" command
736 * The bootm command automatically updates the fdt
738 OF_CPU - The proper name of the cpus node (only required for
739 MPC512X and MPC5xxx based boards).
740 OF_SOC - The proper name of the soc node (only required for
741 MPC512X and MPC5xxx based boards).
742 OF_TBCLK - The timebase frequency.
743 OF_STDOUT_PATH - The path to the console device
745 boards with QUICC Engines require OF_QE to set UCC MAC
748 CONFIG_OF_BOARD_SETUP
750 Board code has addition modification that it wants to make
751 to the flat device tree before handing it off to the kernel
753 CONFIG_OF_SYSTEM_SETUP
755 Other code has addition modification that it wants to make
756 to the flat device tree before handing it off to the kernel.
757 This causes ft_system_setup() to be called before booting
762 This define fills in the correct boot CPU in the boot
763 param header, the default value is zero if undefined.
767 U-Boot can detect if an IDE device is present or not.
768 If not, and this new config option is activated, U-Boot
769 removes the ATA node from the DTS before booting Linux,
770 so the Linux IDE driver does not probe the device and
771 crash. This is needed for buggy hardware (uc101) where
772 no pull down resistor is connected to the signal IDE5V_DD7.
774 CONFIG_MACH_TYPE [relevant for ARM only][mandatory]
776 This setting is mandatory for all boards that have only one
777 machine type and must be used to specify the machine type
778 number as it appears in the ARM machine registry
779 (see http://www.arm.linux.org.uk/developer/machines/).
780 Only boards that have multiple machine types supported
781 in a single configuration file and the machine type is
782 runtime discoverable, do not have to use this setting.
784 - vxWorks boot parameters:
786 bootvx constructs a valid bootline using the following
787 environments variables: bootfile, ipaddr, serverip, hostname.
788 It loads the vxWorks image pointed bootfile.
790 CONFIG_SYS_VXWORKS_BOOT_DEVICE - The vxworks device name
791 CONFIG_SYS_VXWORKS_MAC_PTR - Ethernet 6 byte MA -address
792 CONFIG_SYS_VXWORKS_SERVERNAME - Name of the server
793 CONFIG_SYS_VXWORKS_BOOT_ADDR - Address of boot parameters
795 CONFIG_SYS_VXWORKS_ADD_PARAMS
797 Add it at the end of the bootline. E.g "u=username pw=secret"
799 Note: If a "bootargs" environment is defined, it will overwride
800 the defaults discussed just above.
802 - Cache Configuration:
803 CONFIG_SYS_ICACHE_OFF - Do not enable instruction cache in U-Boot
804 CONFIG_SYS_DCACHE_OFF - Do not enable data cache in U-Boot
805 CONFIG_SYS_L2CACHE_OFF- Do not enable L2 cache in U-Boot
807 - Cache Configuration for ARM:
808 CONFIG_SYS_L2_PL310 - Enable support for ARM PL310 L2 cache
810 CONFIG_SYS_PL310_BASE - Physical base address of PL310
811 controller register space
816 Define this if you want support for Amba PrimeCell PL010 UARTs.
820 Define this if you want support for Amba PrimeCell PL011 UARTs.
824 If you have Amba PrimeCell PL011 UARTs, set this variable to
825 the clock speed of the UARTs.
829 If you have Amba PrimeCell PL010 or PL011 UARTs on your board,
830 define this to a list of base addresses for each (supported)
831 port. See e.g. include/configs/versatile.h
833 CONFIG_PL011_SERIAL_RLCR
835 Some vendor versions of PL011 serial ports (e.g. ST-Ericsson U8500)
836 have separate receive and transmit line control registers. Set
837 this variable to initialize the extra register.
839 CONFIG_PL011_SERIAL_FLUSH_ON_INIT
841 On some platforms (e.g. U8500) U-Boot is loaded by a second stage
842 boot loader that has already initialized the UART. Define this
843 variable to flush the UART at init time.
845 CONFIG_SERIAL_HW_FLOW_CONTROL
847 Define this variable to enable hw flow control in serial driver.
848 Current user of this option is drivers/serial/nsl16550.c driver
851 Depending on board, define exactly one serial port
852 (like CONFIG_8xx_CONS_SMC1, CONFIG_8xx_CONS_SMC2,
853 CONFIG_8xx_CONS_SCC1, ...), or switch off the serial
854 console by defining CONFIG_8xx_CONS_NONE
856 Note: if CONFIG_8xx_CONS_NONE is defined, the serial
857 port routines must be defined elsewhere
858 (i.e. serial_init(), serial_getc(), ...)
861 Enables console device for a color framebuffer. Needs following
862 defines (cf. smiLynxEM, i8042)
863 VIDEO_FB_LITTLE_ENDIAN graphic memory organisation
865 VIDEO_HW_RECTFILL graphic chip supports
868 VIDEO_HW_BITBLT graphic chip supports
869 bit-blit (cf. smiLynxEM)
870 VIDEO_VISIBLE_COLS visible pixel columns
872 VIDEO_VISIBLE_ROWS visible pixel rows
873 VIDEO_PIXEL_SIZE bytes per pixel
874 VIDEO_DATA_FORMAT graphic data format
875 (0-5, cf. cfb_console.c)
876 VIDEO_FB_ADRS framebuffer address
877 VIDEO_KBD_INIT_FCT keyboard int fct
878 (i.e. i8042_kbd_init())
879 VIDEO_TSTC_FCT test char fct
881 VIDEO_GETC_FCT get char fct
883 CONFIG_CONSOLE_CURSOR cursor drawing on/off
884 (requires blink timer
886 CONFIG_SYS_CONSOLE_BLINK_COUNT blink interval (cf. i8042.c)
887 CONFIG_CONSOLE_TIME display time/date info in
889 (requires CONFIG_CMD_DATE)
890 CONFIG_VIDEO_LOGO display Linux logo in
892 CONFIG_VIDEO_BMP_LOGO use bmp_logo.h instead of
893 linux_logo.h for logo.
894 Requires CONFIG_VIDEO_LOGO
895 CONFIG_CONSOLE_EXTRA_INFO
896 additional board info beside
899 When CONFIG_CFB_CONSOLE_ANSI is defined, console will support
900 a limited number of ANSI escape sequences (cursor control,
901 erase functions and limited graphics rendition control).
903 When CONFIG_CFB_CONSOLE is defined, video console is
904 default i/o. Serial console can be forced with
905 environment 'console=serial'.
907 When CONFIG_SILENT_CONSOLE is defined, all console
908 messages (by U-Boot and Linux!) can be silenced with
909 the "silent" environment variable. See
910 doc/README.silent for more information.
912 CONFIG_SYS_CONSOLE_BG_COL: define the backgroundcolor, default
914 CONFIG_SYS_CONSOLE_FG_COL: define the foregroundcolor, default
918 CONFIG_BAUDRATE - in bps
919 Select one of the baudrates listed in
920 CONFIG_SYS_BAUDRATE_TABLE, see below.
921 CONFIG_SYS_BRGCLK_PRESCALE, baudrate prescale
923 - Console Rx buffer length
924 With CONFIG_SYS_SMC_RXBUFLEN it is possible to define
925 the maximum receive buffer length for the SMC.
926 This option is actual only for 82xx and 8xx possible.
927 If using CONFIG_SYS_SMC_RXBUFLEN also CONFIG_SYS_MAXIDLE
928 must be defined, to setup the maximum idle timeout for
931 - Pre-Console Buffer:
932 Prior to the console being initialised (i.e. serial UART
933 initialised etc) all console output is silently discarded.
934 Defining CONFIG_PRE_CONSOLE_BUFFER will cause U-Boot to
935 buffer any console messages prior to the console being
936 initialised to a buffer of size CONFIG_PRE_CON_BUF_SZ
937 bytes located at CONFIG_PRE_CON_BUF_ADDR. The buffer is
938 a circular buffer, so if more than CONFIG_PRE_CON_BUF_SZ
939 bytes are output before the console is initialised, the
940 earlier bytes are discarded.
942 'Sane' compilers will generate smaller code if
943 CONFIG_PRE_CON_BUF_SZ is a power of 2
945 - Safe printf() functions
946 Define CONFIG_SYS_VSNPRINTF to compile in safe versions of
947 the printf() functions. These are defined in
948 include/vsprintf.h and include snprintf(), vsnprintf() and
949 so on. Code size increase is approximately 300-500 bytes.
950 If this option is not given then these functions will
951 silently discard their buffer size argument - this means
952 you are not getting any overflow checking in this case.
954 - Boot Delay: CONFIG_BOOTDELAY - in seconds
955 Delay before automatically booting the default image;
956 set to -1 to disable autoboot.
957 set to -2 to autoboot with no delay and not check for abort
958 (even when CONFIG_ZERO_BOOTDELAY_CHECK is defined).
960 See doc/README.autoboot for these options that
961 work with CONFIG_BOOTDELAY. None are required.
962 CONFIG_BOOT_RETRY_TIME
963 CONFIG_BOOT_RETRY_MIN
964 CONFIG_AUTOBOOT_KEYED
965 CONFIG_AUTOBOOT_PROMPT
966 CONFIG_AUTOBOOT_DELAY_STR
967 CONFIG_AUTOBOOT_STOP_STR
968 CONFIG_AUTOBOOT_DELAY_STR2
969 CONFIG_AUTOBOOT_STOP_STR2
970 CONFIG_ZERO_BOOTDELAY_CHECK
971 CONFIG_RESET_TO_RETRY
975 Only needed when CONFIG_BOOTDELAY is enabled;
976 define a command string that is automatically executed
977 when no character is read on the console interface
978 within "Boot Delay" after reset.
981 This can be used to pass arguments to the bootm
982 command. The value of CONFIG_BOOTARGS goes into the
983 environment value "bootargs".
985 CONFIG_RAMBOOT and CONFIG_NFSBOOT
986 The value of these goes into the environment as
987 "ramboot" and "nfsboot" respectively, and can be used
988 as a convenience, when switching between booting from
992 CONFIG_BOOTCOUNT_LIMIT
993 Implements a mechanism for detecting a repeating reboot
995 http://www.denx.de/wiki/view/DULG/UBootBootCountLimit
998 If no softreset save registers are found on the hardware
999 "bootcount" is stored in the environment. To prevent a
1000 saveenv on all reboots, the environment variable
1001 "upgrade_available" is used. If "upgrade_available" is
1002 0, "bootcount" is always 0, if "upgrade_available" is
1003 1 "bootcount" is incremented in the environment.
1004 So the Userspace Applikation must set the "upgrade_available"
1005 and "bootcount" variable to 0, if a boot was successfully.
1007 - Pre-Boot Commands:
1010 When this option is #defined, the existence of the
1011 environment variable "preboot" will be checked
1012 immediately before starting the CONFIG_BOOTDELAY
1013 countdown and/or running the auto-boot command resp.
1014 entering interactive mode.
1016 This feature is especially useful when "preboot" is
1017 automatically generated or modified. For an example
1018 see the LWMON board specific code: here "preboot" is
1019 modified when the user holds down a certain
1020 combination of keys on the (special) keyboard when
1023 - Serial Download Echo Mode:
1025 If defined to 1, all characters received during a
1026 serial download (using the "loads" command) are
1027 echoed back. This might be needed by some terminal
1028 emulations (like "cu"), but may as well just take
1029 time on others. This setting #define's the initial
1030 value of the "loads_echo" environment variable.
1032 - Kgdb Serial Baudrate: (if CONFIG_CMD_KGDB is defined)
1033 CONFIG_KGDB_BAUDRATE
1034 Select one of the baudrates listed in
1035 CONFIG_SYS_BAUDRATE_TABLE, see below.
1037 - Monitor Functions:
1038 Monitor commands can be included or excluded
1039 from the build by using the #include files
1040 <config_cmd_all.h> and #undef'ing unwanted
1041 commands, or using <config_cmd_default.h>
1042 and augmenting with additional #define's
1043 for wanted commands.
1045 The default command configuration includes all commands
1046 except those marked below with a "*".
1048 CONFIG_CMD_AES AES 128 CBC encrypt/decrypt
1049 CONFIG_CMD_ASKENV * ask for env variable
1050 CONFIG_CMD_BDI bdinfo
1051 CONFIG_CMD_BEDBUG * Include BedBug Debugger
1052 CONFIG_CMD_BMP * BMP support
1053 CONFIG_CMD_BSP * Board specific commands
1054 CONFIG_CMD_BOOTD bootd
1055 CONFIG_CMD_BOOTI * ARM64 Linux kernel Image support
1056 CONFIG_CMD_CACHE * icache, dcache
1057 CONFIG_CMD_CLK * clock command support
1058 CONFIG_CMD_CONSOLE coninfo
1059 CONFIG_CMD_CRC32 * crc32
1060 CONFIG_CMD_DATE * support for RTC, date/time...
1061 CONFIG_CMD_DHCP * DHCP support
1062 CONFIG_CMD_DIAG * Diagnostics
1063 CONFIG_CMD_DS4510 * ds4510 I2C gpio commands
1064 CONFIG_CMD_DS4510_INFO * ds4510 I2C info command
1065 CONFIG_CMD_DS4510_MEM * ds4510 I2C eeprom/sram commansd
1066 CONFIG_CMD_DS4510_RST * ds4510 I2C rst command
1067 CONFIG_CMD_DTT * Digital Therm and Thermostat
1068 CONFIG_CMD_ECHO echo arguments
1069 CONFIG_CMD_EDITENV edit env variable
1070 CONFIG_CMD_EEPROM * EEPROM read/write support
1071 CONFIG_CMD_ELF * bootelf, bootvx
1072 CONFIG_CMD_ENV_CALLBACK * display details about env callbacks
1073 CONFIG_CMD_ENV_FLAGS * display details about env flags
1074 CONFIG_CMD_ENV_EXISTS * check existence of env variable
1075 CONFIG_CMD_EXPORTENV * export the environment
1076 CONFIG_CMD_EXT2 * ext2 command support
1077 CONFIG_CMD_EXT4 * ext4 command support
1078 CONFIG_CMD_FS_GENERIC * filesystem commands (e.g. load, ls)
1079 that work for multiple fs types
1080 CONFIG_CMD_FS_UUID * Look up a filesystem UUID
1081 CONFIG_CMD_SAVEENV saveenv
1082 CONFIG_CMD_FDC * Floppy Disk Support
1083 CONFIG_CMD_FAT * FAT command support
1084 CONFIG_CMD_FLASH flinfo, erase, protect
1085 CONFIG_CMD_FPGA FPGA device initialization support
1086 CONFIG_CMD_FUSE * Device fuse support
1087 CONFIG_CMD_GETTIME * Get time since boot
1088 CONFIG_CMD_GO * the 'go' command (exec code)
1089 CONFIG_CMD_GREPENV * search environment
1090 CONFIG_CMD_HASH * calculate hash / digest
1091 CONFIG_CMD_HWFLOW * RTS/CTS hw flow control
1092 CONFIG_CMD_I2C * I2C serial bus support
1093 CONFIG_CMD_IDE * IDE harddisk support
1094 CONFIG_CMD_IMI iminfo
1095 CONFIG_CMD_IMLS List all images found in NOR flash
1096 CONFIG_CMD_IMLS_NAND * List all images found in NAND flash
1097 CONFIG_CMD_IMMAP * IMMR dump support
1098 CONFIG_CMD_IOTRACE * I/O tracing for debugging
1099 CONFIG_CMD_IMPORTENV * import an environment
1100 CONFIG_CMD_INI * import data from an ini file into the env
1101 CONFIG_CMD_IRQ * irqinfo
1102 CONFIG_CMD_ITEST Integer/string test of 2 values
1103 CONFIG_CMD_JFFS2 * JFFS2 Support
1104 CONFIG_CMD_KGDB * kgdb
1105 CONFIG_CMD_LDRINFO * ldrinfo (display Blackfin loader)
1106 CONFIG_CMD_LINK_LOCAL * link-local IP address auto-configuration
1108 CONFIG_CMD_LOADB loadb
1109 CONFIG_CMD_LOADS loads
1110 CONFIG_CMD_MD5SUM * print md5 message digest
1111 (requires CONFIG_CMD_MEMORY and CONFIG_MD5)
1112 CONFIG_CMD_MEMINFO * Display detailed memory information
1113 CONFIG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base,
1115 CONFIG_CMD_MEMTEST * mtest
1116 CONFIG_CMD_MISC Misc functions like sleep etc
1117 CONFIG_CMD_MMC * MMC memory mapped support
1118 CONFIG_CMD_MII * MII utility commands
1119 CONFIG_CMD_MTDPARTS * MTD partition support
1120 CONFIG_CMD_NAND * NAND support
1121 CONFIG_CMD_NET bootp, tftpboot, rarpboot
1122 CONFIG_CMD_NFS NFS support
1123 CONFIG_CMD_PCA953X * PCA953x I2C gpio commands
1124 CONFIG_CMD_PCA953X_INFO * PCA953x I2C gpio info command
1125 CONFIG_CMD_PCI * pciinfo
1126 CONFIG_CMD_PCMCIA * PCMCIA support
1127 CONFIG_CMD_PING * send ICMP ECHO_REQUEST to network
1129 CONFIG_CMD_PORTIO * Port I/O
1130 CONFIG_CMD_READ * Read raw data from partition
1131 CONFIG_CMD_REGINFO * Register dump
1132 CONFIG_CMD_RUN run command in env variable
1133 CONFIG_CMD_SANDBOX * sb command to access sandbox features
1134 CONFIG_CMD_SAVES * save S record dump
1135 CONFIG_CMD_SCSI * SCSI Support
1136 CONFIG_CMD_SDRAM * print SDRAM configuration information
1137 (requires CONFIG_CMD_I2C)
1138 CONFIG_CMD_SETGETDCR Support for DCR Register access
1140 CONFIG_CMD_SF * Read/write/erase SPI NOR flash
1141 CONFIG_CMD_SHA1SUM * print sha1 memory digest
1142 (requires CONFIG_CMD_MEMORY)
1143 CONFIG_CMD_SOFTSWITCH * Soft switch setting command for BF60x
1144 CONFIG_CMD_SOURCE "source" command Support
1145 CONFIG_CMD_SPI * SPI serial bus support
1146 CONFIG_CMD_TFTPSRV * TFTP transfer in server mode
1147 CONFIG_CMD_TFTPPUT * TFTP put command (upload)
1148 CONFIG_CMD_TIME * run command and report execution time (ARM specific)
1149 CONFIG_CMD_TIMER * access to the system tick timer
1150 CONFIG_CMD_USB * USB support
1151 CONFIG_CMD_CDP * Cisco Discover Protocol support
1152 CONFIG_CMD_MFSL * Microblaze FSL support
1153 CONFIG_CMD_XIMG Load part of Multi Image
1154 CONFIG_CMD_UUID * Generate random UUID or GUID string
1156 EXAMPLE: If you want all functions except of network
1157 support you can write:
1159 #include "config_cmd_all.h"
1160 #undef CONFIG_CMD_NET
1163 fdt (flattened device tree) command: CONFIG_OF_LIBFDT
1165 Note: Don't enable the "icache" and "dcache" commands
1166 (configuration option CONFIG_CMD_CACHE) unless you know
1167 what you (and your U-Boot users) are doing. Data
1168 cache cannot be enabled on systems like the 8xx or
1169 8260 (where accesses to the IMMR region must be
1170 uncached), and it cannot be disabled on all other
1171 systems where we (mis-) use the data cache to hold an
1172 initial stack and some data.
1175 XXX - this list needs to get updated!
1177 - Regular expression support:
1179 If this variable is defined, U-Boot is linked against
1180 the SLRE (Super Light Regular Expression) library,
1181 which adds regex support to some commands, as for
1182 example "env grep" and "setexpr".
1186 If this variable is defined, U-Boot will use a device tree
1187 to configure its devices, instead of relying on statically
1188 compiled #defines in the board file. This option is
1189 experimental and only available on a few boards. The device
1190 tree is available in the global data as gd->fdt_blob.
1192 U-Boot needs to get its device tree from somewhere. This can
1193 be done using one of the two options below:
1196 If this variable is defined, U-Boot will embed a device tree
1197 binary in its image. This device tree file should be in the
1198 board directory and called <soc>-<board>.dts. The binary file
1199 is then picked up in board_init_f() and made available through
1200 the global data structure as gd->blob.
1203 If this variable is defined, U-Boot will build a device tree
1204 binary. It will be called u-boot.dtb. Architecture-specific
1205 code will locate it at run-time. Generally this works by:
1207 cat u-boot.bin u-boot.dtb >image.bin
1209 and in fact, U-Boot does this for you, creating a file called
1210 u-boot-dtb.bin which is useful in the common case. You can
1211 still use the individual files if you need something more
1216 If this variable is defined, it enables watchdog
1217 support for the SoC. There must be support in the SoC
1218 specific code for a watchdog. For the 8xx and 8260
1219 CPUs, the SIU Watchdog feature is enabled in the SYPCR
1220 register. When supported for a specific SoC is
1221 available, then no further board specific code should
1222 be needed to use it.
1225 When using a watchdog circuitry external to the used
1226 SoC, then define this variable and provide board
1227 specific code for the "hw_watchdog_reset" function.
1229 CONFIG_AT91_HW_WDT_TIMEOUT
1230 specify the timeout in seconds. default 2 seconds.
1233 CONFIG_VERSION_VARIABLE
1234 If this variable is defined, an environment variable
1235 named "ver" is created by U-Boot showing the U-Boot
1236 version as printed by the "version" command.
1237 Any change to this variable will be reverted at the
1242 When CONFIG_CMD_DATE is selected, the type of the RTC
1243 has to be selected, too. Define exactly one of the
1246 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx
1247 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC
1248 CONFIG_RTC_MC13XXX - use MC13783 or MC13892 RTC
1249 CONFIG_RTC_MC146818 - use MC146818 RTC
1250 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC
1251 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC
1252 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC
1253 CONFIG_RTC_DS1339 - use Maxim, Inc. DS1339 RTC
1254 CONFIG_RTC_DS164x - use Dallas DS164x RTC
1255 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC
1256 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC
1257 CONFIG_SYS_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337
1258 CONFIG_SYS_RV3029_TCR - enable trickle charger on
1261 Note that if the RTC uses I2C, then the I2C interface
1262 must also be configured. See I2C Support, below.
1265 CONFIG_PCA953X - use NXP's PCA953X series I2C GPIO
1267 The CONFIG_SYS_I2C_PCA953X_WIDTH option specifies a list of
1268 chip-ngpio pairs that tell the PCA953X driver the number of
1269 pins supported by a particular chip.
1271 Note that if the GPIO device uses I2C, then the I2C interface
1272 must also be configured. See I2C Support, below.
1275 When CONFIG_IO_TRACE is selected, U-Boot intercepts all I/O
1276 accesses and can checksum them or write a list of them out
1277 to memory. See the 'iotrace' command for details. This is
1278 useful for testing device drivers since it can confirm that
1279 the driver behaves the same way before and after a code
1280 change. Currently this is supported on sandbox and arm. To
1281 add support for your architecture, add '#include <iotrace.h>'
1282 to the bottom of arch/<arch>/include/asm/io.h and test.
1284 Example output from the 'iotrace stats' command is below.
1285 Note that if the trace buffer is exhausted, the checksum will
1286 still continue to operate.
1289 Start: 10000000 (buffer start address)
1290 Size: 00010000 (buffer size)
1291 Offset: 00000120 (current buffer offset)
1292 Output: 10000120 (start + offset)
1293 Count: 00000018 (number of trace records)
1294 CRC32: 9526fb66 (CRC32 of all trace records)
1296 - Timestamp Support:
1298 When CONFIG_TIMESTAMP is selected, the timestamp
1299 (date and time) of an image is printed by image
1300 commands like bootm or iminfo. This option is
1301 automatically enabled when you select CONFIG_CMD_DATE .
1303 - Partition Labels (disklabels) Supported:
1304 Zero or more of the following:
1305 CONFIG_MAC_PARTITION Apple's MacOS partition table.
1306 CONFIG_DOS_PARTITION MS Dos partition table, traditional on the
1307 Intel architecture, USB sticks, etc.
1308 CONFIG_ISO_PARTITION ISO partition table, used on CDROM etc.
1309 CONFIG_EFI_PARTITION GPT partition table, common when EFI is the
1310 bootloader. Note 2TB partition limit; see
1312 CONFIG_MTD_PARTITIONS Memory Technology Device partition table.
1314 If IDE or SCSI support is enabled (CONFIG_CMD_IDE or
1315 CONFIG_CMD_SCSI) you must configure support for at
1316 least one non-MTD partition type as well.
1319 CONFIG_IDE_RESET_ROUTINE - this is defined in several
1320 board configurations files but used nowhere!
1322 CONFIG_IDE_RESET - is this is defined, IDE Reset will
1323 be performed by calling the function
1324 ide_set_reset(int reset)
1325 which has to be defined in a board specific file
1330 Set this to enable ATAPI support.
1335 Set this to enable support for disks larger than 137GB
1336 Also look at CONFIG_SYS_64BIT_LBA.
1337 Whithout these , LBA48 support uses 32bit variables and will 'only'
1338 support disks up to 2.1TB.
1340 CONFIG_SYS_64BIT_LBA:
1341 When enabled, makes the IDE subsystem use 64bit sector addresses.
1345 At the moment only there is only support for the
1346 SYM53C8XX SCSI controller; define
1347 CONFIG_SCSI_SYM53C8XX to enable it.
1349 CONFIG_SYS_SCSI_MAX_LUN [8], CONFIG_SYS_SCSI_MAX_SCSI_ID [7] and
1350 CONFIG_SYS_SCSI_MAX_DEVICE [CONFIG_SYS_SCSI_MAX_SCSI_ID *
1351 CONFIG_SYS_SCSI_MAX_LUN] can be adjusted to define the
1352 maximum numbers of LUNs, SCSI ID's and target
1354 CONFIG_SYS_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz)
1356 The environment variable 'scsidevs' is set to the number of
1357 SCSI devices found during the last scan.
1359 - NETWORK Support (PCI):
1361 Support for Intel 8254x/8257x gigabit chips.
1364 Utility code for direct access to the SPI bus on Intel 8257x.
1365 This does not do anything useful unless you set at least one
1366 of CONFIG_CMD_E1000 or CONFIG_E1000_SPI_GENERIC.
1368 CONFIG_E1000_SPI_GENERIC
1369 Allow generic access to the SPI bus on the Intel 8257x, for
1370 example with the "sspi" command.
1373 Management command for E1000 devices. When used on devices
1374 with SPI support you can reprogram the EEPROM from U-Boot.
1376 CONFIG_E1000_FALLBACK_MAC
1377 default MAC for empty EEPROM after production.
1380 Support for Intel 82557/82559/82559ER chips.
1381 Optional CONFIG_EEPRO100_SROM_WRITE enables EEPROM
1382 write routine for first time initialisation.
1385 Support for Digital 2114x chips.
1386 Optional CONFIG_TULIP_SELECT_MEDIA for board specific
1387 modem chip initialisation (KS8761/QS6611).
1390 Support for National dp83815 chips.
1393 Support for National dp8382[01] gigabit chips.
1395 - NETWORK Support (other):
1397 CONFIG_DRIVER_AT91EMAC
1398 Support for AT91RM9200 EMAC.
1401 Define this to use reduced MII inteface
1403 CONFIG_DRIVER_AT91EMAC_QUIET
1404 If this defined, the driver is quiet.
1405 The driver doen't show link status messages.
1407 CONFIG_CALXEDA_XGMAC
1408 Support for the Calxeda XGMAC device
1411 Support for SMSC's LAN91C96 chips.
1413 CONFIG_LAN91C96_BASE
1414 Define this to hold the physical address
1415 of the LAN91C96's I/O space
1417 CONFIG_LAN91C96_USE_32_BIT
1418 Define this to enable 32 bit addressing
1421 Support for SMSC's LAN91C111 chip
1423 CONFIG_SMC91111_BASE
1424 Define this to hold the physical address
1425 of the device (I/O space)
1427 CONFIG_SMC_USE_32_BIT
1428 Define this if data bus is 32 bits
1430 CONFIG_SMC_USE_IOFUNCS
1431 Define this to use i/o functions instead of macros
1432 (some hardware wont work with macros)
1434 CONFIG_DRIVER_TI_EMAC
1435 Support for davinci emac
1437 CONFIG_SYS_DAVINCI_EMAC_PHY_COUNT
1438 Define this if you have more then 3 PHYs.
1441 Support for Faraday's FTGMAC100 Gigabit SoC Ethernet
1443 CONFIG_FTGMAC100_EGIGA
1444 Define this to use GE link update with gigabit PHY.
1445 Define this if FTGMAC100 is connected to gigabit PHY.
1446 If your system has 10/100 PHY only, it might not occur
1447 wrong behavior. Because PHY usually return timeout or
1448 useless data when polling gigabit status and gigabit
1449 control registers. This behavior won't affect the
1450 correctnessof 10/100 link speed update.
1453 Support for SMSC's LAN911x and LAN921x chips
1456 Define this to hold the physical address
1457 of the device (I/O space)
1459 CONFIG_SMC911X_32_BIT
1460 Define this if data bus is 32 bits
1462 CONFIG_SMC911X_16_BIT
1463 Define this if data bus is 16 bits. If your processor
1464 automatically converts one 32 bit word to two 16 bit
1465 words you may also try CONFIG_SMC911X_32_BIT.
1468 Support for Renesas on-chip Ethernet controller
1470 CONFIG_SH_ETHER_USE_PORT
1471 Define the number of ports to be used
1473 CONFIG_SH_ETHER_PHY_ADDR
1474 Define the ETH PHY's address
1476 CONFIG_SH_ETHER_CACHE_WRITEBACK
1477 If this option is set, the driver enables cache flush.
1481 Support for PWM modul on the imx6.
1485 Support TPM devices.
1488 Support for i2c bus TPM devices. Only one device
1489 per system is supported at this time.
1491 CONFIG_TPM_TIS_I2C_BUS_NUMBER
1492 Define the the i2c bus number for the TPM device
1494 CONFIG_TPM_TIS_I2C_SLAVE_ADDRESS
1495 Define the TPM's address on the i2c bus
1497 CONFIG_TPM_TIS_I2C_BURST_LIMITATION
1498 Define the burst count bytes upper limit
1500 CONFIG_TPM_ATMEL_TWI
1501 Support for Atmel TWI TPM device. Requires I2C support.
1504 Support for generic parallel port TPM devices. Only one device
1505 per system is supported at this time.
1507 CONFIG_TPM_TIS_BASE_ADDRESS
1508 Base address where the generic TPM device is mapped
1509 to. Contemporary x86 systems usually map it at
1513 Add tpm monitor functions.
1514 Requires CONFIG_TPM. If CONFIG_TPM_AUTH_SESSIONS is set, also
1515 provides monitor access to authorized functions.
1518 Define this to enable the TPM support library which provides
1519 functional interfaces to some TPM commands.
1520 Requires support for a TPM device.
1522 CONFIG_TPM_AUTH_SESSIONS
1523 Define this to enable authorized functions in the TPM library.
1524 Requires CONFIG_TPM and CONFIG_SHA1.
1527 At the moment only the UHCI host controller is
1528 supported (PIP405, MIP405, MPC5200); define
1529 CONFIG_USB_UHCI to enable it.
1530 define CONFIG_USB_KEYBOARD to enable the USB Keyboard
1531 and define CONFIG_USB_STORAGE to enable the USB
1534 Supported are USB Keyboards and USB Floppy drives
1536 MPC5200 USB requires additional defines:
1538 for 528 MHz Clock: 0x0001bbbb
1542 for differential drivers: 0x00001000
1543 for single ended drivers: 0x00005000
1544 for differential drivers on PSC3: 0x00000100
1545 for single ended drivers on PSC3: 0x00004100
1546 CONFIG_SYS_USB_EVENT_POLL
1547 May be defined to allow interrupt polling
1548 instead of using asynchronous interrupts
1550 CONFIG_USB_EHCI_TXFIFO_THRESH enables setting of the
1551 txfilltuning field in the EHCI controller on reset.
1553 CONFIG_USB_DWC2_REG_ADDR the physical CPU address of the DWC2
1554 HW module registers.
1557 Define the below if you wish to use the USB console.
1558 Once firmware is rebuilt from a serial console issue the
1559 command "setenv stdin usbtty; setenv stdout usbtty" and
1560 attach your USB cable. The Unix command "dmesg" should print
1561 it has found a new device. The environment variable usbtty
1562 can be set to gserial or cdc_acm to enable your device to
1563 appear to a USB host as a Linux gserial device or a
1564 Common Device Class Abstract Control Model serial device.
1565 If you select usbtty = gserial you should be able to enumerate
1567 # modprobe usbserial vendor=0xVendorID product=0xProductID
1568 else if using cdc_acm, simply setting the environment
1569 variable usbtty to be cdc_acm should suffice. The following
1570 might be defined in YourBoardName.h
1573 Define this to build a UDC device
1576 Define this to have a tty type of device available to
1577 talk to the UDC device
1580 Define this to enable the high speed support for usb
1581 device and usbtty. If this feature is enabled, a routine
1582 int is_usbd_high_speed(void)
1583 also needs to be defined by the driver to dynamically poll
1584 whether the enumeration has succeded at high speed or full
1587 CONFIG_SYS_CONSOLE_IS_IN_ENV
1588 Define this if you want stdin, stdout &/or stderr to
1592 CONFIG_SYS_USB_EXTC_CLK 0xBLAH
1593 Derive USB clock from external clock "blah"
1594 - CONFIG_SYS_USB_EXTC_CLK 0x02
1596 CONFIG_SYS_USB_BRG_CLK 0xBLAH
1597 Derive USB clock from brgclk
1598 - CONFIG_SYS_USB_BRG_CLK 0x04
1600 If you have a USB-IF assigned VendorID then you may wish to
1601 define your own vendor specific values either in BoardName.h
1602 or directly in usbd_vendor_info.h. If you don't define
1603 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME,
1604 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot
1605 should pretend to be a Linux device to it's target host.
1607 CONFIG_USBD_MANUFACTURER
1608 Define this string as the name of your company for
1609 - CONFIG_USBD_MANUFACTURER "my company"
1611 CONFIG_USBD_PRODUCT_NAME
1612 Define this string as the name of your product
1613 - CONFIG_USBD_PRODUCT_NAME "acme usb device"
1615 CONFIG_USBD_VENDORID
1616 Define this as your assigned Vendor ID from the USB
1617 Implementors Forum. This *must* be a genuine Vendor ID
1618 to avoid polluting the USB namespace.
1619 - CONFIG_USBD_VENDORID 0xFFFF
1621 CONFIG_USBD_PRODUCTID
1622 Define this as the unique Product ID
1624 - CONFIG_USBD_PRODUCTID 0xFFFF
1626 - ULPI Layer Support:
1627 The ULPI (UTMI Low Pin (count) Interface) PHYs are supported via
1628 the generic ULPI layer. The generic layer accesses the ULPI PHY
1629 via the platform viewport, so you need both the genric layer and
1630 the viewport enabled. Currently only Chipidea/ARC based
1631 viewport is supported.
1632 To enable the ULPI layer support, define CONFIG_USB_ULPI and
1633 CONFIG_USB_ULPI_VIEWPORT in your board configuration file.
1634 If your ULPI phy needs a different reference clock than the
1635 standard 24 MHz then you have to define CONFIG_ULPI_REF_CLK to
1636 the appropriate value in Hz.
1639 The MMC controller on the Intel PXA is supported. To
1640 enable this define CONFIG_MMC. The MMC can be
1641 accessed from the boot prompt by mapping the device
1642 to physical memory similar to flash. Command line is
1643 enabled with CONFIG_CMD_MMC. The MMC driver also works with
1644 the FAT fs. This is enabled with CONFIG_CMD_FAT.
1647 Support for Renesas on-chip MMCIF controller
1649 CONFIG_SH_MMCIF_ADDR
1650 Define the base address of MMCIF registers
1653 Define the clock frequency for MMCIF
1656 Enable the generic MMC driver
1658 CONFIG_SUPPORT_EMMC_BOOT
1659 Enable some additional features of the eMMC boot partitions.
1661 CONFIG_SUPPORT_EMMC_RPMB
1662 Enable the commands for reading, writing and programming the
1663 key for the Replay Protection Memory Block partition in eMMC.
1665 - USB Device Firmware Update (DFU) class support:
1667 This enables the USB portion of the DFU USB class
1670 This enables the command "dfu" which is used to have
1671 U-Boot create a DFU class device via USB. This command
1672 requires that the "dfu_alt_info" environment variable be
1673 set and define the alt settings to expose to the host.
1676 This enables support for exposing (e)MMC devices via DFU.
1679 This enables support for exposing NAND devices via DFU.
1682 This enables support for exposing RAM via DFU.
1683 Note: DFU spec refer to non-volatile memory usage, but
1684 allow usages beyond the scope of spec - here RAM usage,
1685 one that would help mostly the developer.
1687 CONFIG_SYS_DFU_DATA_BUF_SIZE
1688 Dfu transfer uses a buffer before writing data to the
1689 raw storage device. Make the size (in bytes) of this buffer
1690 configurable. The size of this buffer is also configurable
1691 through the "dfu_bufsiz" environment variable.
1693 CONFIG_SYS_DFU_MAX_FILE_SIZE
1694 When updating files rather than the raw storage device,
1695 we use a static buffer to copy the file into and then write
1696 the buffer once we've been given the whole file. Define
1697 this to the maximum filesize (in bytes) for the buffer.
1698 Default is 4 MiB if undefined.
1700 DFU_DEFAULT_POLL_TIMEOUT
1701 Poll timeout [ms], is the timeout a device can send to the
1702 host. The host must wait for this timeout before sending
1703 a subsequent DFU_GET_STATUS request to the device.
1705 DFU_MANIFEST_POLL_TIMEOUT
1706 Poll timeout [ms], which the device sends to the host when
1707 entering dfuMANIFEST state. Host waits this timeout, before
1708 sending again an USB request to the device.
1710 - USB Device Android Fastboot support:
1712 This enables the command "fastboot" which enables the Android
1713 fastboot mode for the platform's USB device. Fastboot is a USB
1714 protocol for downloading images, flashing and device control
1715 used on Android devices.
1716 See doc/README.android-fastboot for more information.
1718 CONFIG_ANDROID_BOOT_IMAGE
1719 This enables support for booting images which use the Android
1720 image format header.
1722 CONFIG_USB_FASTBOOT_BUF_ADDR
1723 The fastboot protocol requires a large memory buffer for
1724 downloads. Define this to the starting RAM address to use for
1727 CONFIG_USB_FASTBOOT_BUF_SIZE
1728 The fastboot protocol requires a large memory buffer for
1729 downloads. This buffer should be as large as possible for a
1730 platform. Define this to the size available RAM for fastboot.
1732 CONFIG_FASTBOOT_FLASH
1733 The fastboot protocol includes a "flash" command for writing
1734 the downloaded image to a non-volatile storage device. Define
1735 this to enable the "fastboot flash" command.
1737 CONFIG_FASTBOOT_FLASH_MMC_DEV
1738 The fastboot "flash" command requires additional information
1739 regarding the non-volatile storage device. Define this to
1740 the eMMC device that fastboot should use to store the image.
1742 CONFIG_FASTBOOT_GPT_NAME
1743 The fastboot "flash" command supports writing the downloaded
1744 image to the Protective MBR and the Primary GUID Partition
1745 Table. (Additionally, this downloaded image is post-processed
1746 to generate and write the Backup GUID Partition Table.)
1747 This occurs when the specified "partition name" on the
1748 "fastboot flash" command line matches this value.
1749 Default is GPT_ENTRY_NAME (currently "gpt") if undefined.
1751 - Journaling Flash filesystem support:
1752 CONFIG_JFFS2_NAND, CONFIG_JFFS2_NAND_OFF, CONFIG_JFFS2_NAND_SIZE,
1753 CONFIG_JFFS2_NAND_DEV
1754 Define these for a default partition on a NAND device
1756 CONFIG_SYS_JFFS2_FIRST_SECTOR,
1757 CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS
1758 Define these for a default partition on a NOR device
1760 CONFIG_SYS_JFFS_CUSTOM_PART
1761 Define this to create an own partition. You have to provide a
1762 function struct part_info* jffs2_part_info(int part_num)
1764 If you define only one JFFS2 partition you may also want to
1765 #define CONFIG_SYS_JFFS_SINGLE_PART 1
1766 to disable the command chpart. This is the default when you
1767 have not defined a custom partition
1769 - FAT(File Allocation Table) filesystem write function support:
1772 Define this to enable support for saving memory data as a
1773 file in FAT formatted partition.
1775 This will also enable the command "fatwrite" enabling the
1776 user to write files to FAT.
1778 CBFS (Coreboot Filesystem) support
1781 Define this to enable support for reading from a Coreboot
1782 filesystem. Available commands are cbfsinit, cbfsinfo, cbfsls
1785 - FAT(File Allocation Table) filesystem cluster size:
1786 CONFIG_FS_FAT_MAX_CLUSTSIZE
1788 Define the max cluster size for fat operations else
1789 a default value of 65536 will be defined.
1794 Define this to enable standard (PC-Style) keyboard
1798 Standard PC keyboard driver with US (is default) and
1799 GERMAN key layout (switch via environment 'keymap=de') support.
1800 Export function i8042_kbd_init, i8042_tstc and i8042_getc
1801 for cfb_console. Supports cursor blinking.
1804 Enables a Chrome OS keyboard using the CROS_EC interface.
1805 This uses CROS_EC to communicate with a second microcontroller
1806 which provides key scans on request.
1811 Define this to enable video support (for output to
1814 CONFIG_VIDEO_CT69000
1816 Enable Chips & Technologies 69000 Video chip
1818 CONFIG_VIDEO_SMI_LYNXEM
1819 Enable Silicon Motion SMI 712/710/810 Video chip. The
1820 video output is selected via environment 'videoout'
1821 (1 = LCD and 2 = CRT). If videoout is undefined, CRT is
1824 For the CT69000 and SMI_LYNXEM drivers, videomode is
1825 selected via environment 'videomode'. Two different ways
1827 - "videomode=num" 'num' is a standard LiLo mode numbers.
1828 Following standard modes are supported (* is default):
1830 Colors 640x480 800x600 1024x768 1152x864 1280x1024
1831 -------------+---------------------------------------------
1832 8 bits | 0x301* 0x303 0x305 0x161 0x307
1833 15 bits | 0x310 0x313 0x316 0x162 0x319
1834 16 bits | 0x311 0x314 0x317 0x163 0x31A
1835 24 bits | 0x312 0x315 0x318 ? 0x31B
1836 -------------+---------------------------------------------
1837 (i.e. setenv videomode 317; saveenv; reset;)
1839 - "videomode=bootargs" all the video parameters are parsed
1840 from the bootargs. (See drivers/video/videomodes.c)
1843 CONFIG_VIDEO_SED13806
1844 Enable Epson SED13806 driver. This driver supports 8bpp
1845 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP
1846 or CONFIG_VIDEO_SED13806_16BPP
1849 Enable the Freescale DIU video driver. Reference boards for
1850 SOCs that have a DIU should define this macro to enable DIU
1851 support, and should also define these other macros:
1857 CONFIG_VIDEO_SW_CURSOR
1858 CONFIG_VGA_AS_SINGLE_DEVICE
1860 CONFIG_VIDEO_BMP_LOGO
1862 The DIU driver will look for the 'video-mode' environment
1863 variable, and if defined, enable the DIU as a console during
1864 boot. See the documentation file README.video for a
1865 description of this variable.
1869 Enable the VGA video / BIOS for x86. The alternative if you
1870 are using coreboot is to use the coreboot frame buffer
1877 Define this to enable a custom keyboard support.
1878 This simply calls drv_keyboard_init() which must be
1879 defined in your board-specific files.
1880 The only board using this so far is RBC823.
1882 - LCD Support: CONFIG_LCD
1884 Define this to enable LCD support (for output to LCD
1885 display); also select one of the supported displays
1886 by defining one of these:
1890 HITACHI TX09D70VM1CCA, 3.5", 240x320.
1892 CONFIG_NEC_NL6448AC33:
1894 NEC NL6448AC33-18. Active, color, single scan.
1896 CONFIG_NEC_NL6448BC20
1898 NEC NL6448BC20-08. 6.5", 640x480.
1899 Active, color, single scan.
1901 CONFIG_NEC_NL6448BC33_54
1903 NEC NL6448BC33-54. 10.4", 640x480.
1904 Active, color, single scan.
1908 Sharp 320x240. Active, color, single scan.
1909 It isn't 16x9, and I am not sure what it is.
1911 CONFIG_SHARP_LQ64D341
1913 Sharp LQ64D341 display, 640x480.
1914 Active, color, single scan.
1918 HLD1045 display, 640x480.
1919 Active, color, single scan.
1923 Optrex CBL50840-2 NF-FW 99 22 M5
1925 Hitachi LMG6912RPFC-00T
1929 320x240. Black & white.
1931 Normally display is black on white background; define
1932 CONFIG_SYS_WHITE_ON_BLACK to get it inverted.
1934 CONFIG_LCD_ALIGNMENT
1936 Normally the LCD is page-aligned (typically 4KB). If this is
1937 defined then the LCD will be aligned to this value instead.
1938 For ARM it is sometimes useful to use MMU_SECTION_SIZE
1939 here, since it is cheaper to change data cache settings on
1940 a per-section basis.
1942 CONFIG_CONSOLE_SCROLL_LINES
1944 When the console need to be scrolled, this is the number of
1945 lines to scroll by. It defaults to 1. Increasing this makes
1946 the console jump but can help speed up operation when scrolling
1951 Support drawing of RLE8-compressed bitmaps on the LCD.
1955 Enables an 'i2c edid' command which can read EDID
1956 information over I2C from an attached LCD display.
1958 - Splash Screen Support: CONFIG_SPLASH_SCREEN
1960 If this option is set, the environment is checked for
1961 a variable "splashimage". If found, the usual display
1962 of logo, copyright and system information on the LCD
1963 is suppressed and the BMP image at the address
1964 specified in "splashimage" is loaded instead. The
1965 console is redirected to the "nulldev", too. This
1966 allows for a "silent" boot where a splash screen is
1967 loaded very quickly after power-on.
1969 CONFIG_SPLASHIMAGE_GUARD
1971 If this option is set, then U-Boot will prevent the environment
1972 variable "splashimage" from being set to a problematic address
1973 (see README.displaying-bmps).
1974 This option is useful for targets where, due to alignment
1975 restrictions, an improperly aligned BMP image will cause a data
1976 abort. If you think you will not have problems with unaligned
1977 accesses (for example because your toolchain prevents them)
1978 there is no need to set this option.
1980 CONFIG_SPLASH_SCREEN_ALIGN
1982 If this option is set the splash image can be freely positioned
1983 on the screen. Environment variable "splashpos" specifies the
1984 position as "x,y". If a positive number is given it is used as
1985 number of pixel from left/top. If a negative number is given it
1986 is used as number of pixel from right/bottom. You can also
1987 specify 'm' for centering the image.
1990 setenv splashpos m,m
1991 => image at center of screen
1993 setenv splashpos 30,20
1994 => image at x = 30 and y = 20
1996 setenv splashpos -10,m
1997 => vertically centered image
1998 at x = dspWidth - bmpWidth - 9
2000 - Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP
2002 If this option is set, additionally to standard BMP
2003 images, gzipped BMP images can be displayed via the
2004 splashscreen support or the bmp command.
2006 - Run length encoded BMP image (RLE8) support: CONFIG_VIDEO_BMP_RLE8
2008 If this option is set, 8-bit RLE compressed BMP images
2009 can be displayed via the splashscreen support or the
2012 - Do compressing for memory range:
2015 If this option is set, it would use zlib deflate method
2016 to compress the specified memory at its best effort.
2018 - Compression support:
2021 Enabled by default to support gzip compressed images.
2025 If this option is set, support for bzip2 compressed
2026 images is included. If not, only uncompressed and gzip
2027 compressed images are supported.
2029 NOTE: the bzip2 algorithm requires a lot of RAM, so
2030 the malloc area (as defined by CONFIG_SYS_MALLOC_LEN) should
2035 If this option is set, support for lzma compressed
2038 Note: The LZMA algorithm adds between 2 and 4KB of code and it
2039 requires an amount of dynamic memory that is given by the
2042 (1846 + 768 << (lc + lp)) * sizeof(uint16)
2044 Where lc and lp stand for, respectively, Literal context bits
2045 and Literal pos bits.
2047 This value is upper-bounded by 14MB in the worst case. Anyway,
2048 for a ~4MB large kernel image, we have lc=3 and lp=0 for a
2049 total amount of (1846 + 768 << (3 + 0)) * 2 = ~41KB... that is
2050 a very small buffer.
2052 Use the lzmainfo tool to determinate the lc and lp values and
2053 then calculate the amount of needed dynamic memory (ensuring
2054 the appropriate CONFIG_SYS_MALLOC_LEN value).
2058 If this option is set, support for LZO compressed images
2064 The address of PHY on MII bus.
2066 CONFIG_PHY_CLOCK_FREQ (ppc4xx)
2068 The clock frequency of the MII bus
2072 If this option is set, support for speed/duplex
2073 detection of gigabit PHY is included.
2075 CONFIG_PHY_RESET_DELAY
2077 Some PHY like Intel LXT971A need extra delay after
2078 reset before any MII register access is possible.
2079 For such PHY, set this option to the usec delay
2080 required. (minimum 300usec for LXT971A)
2082 CONFIG_PHY_CMD_DELAY (ppc4xx)
2084 Some PHY like Intel LXT971A need extra delay after
2085 command issued before MII status register can be read
2095 Define a default value for Ethernet address to use
2096 for the respective Ethernet interface, in case this
2097 is not determined automatically.
2102 Define a default value for the IP address to use for
2103 the default Ethernet interface, in case this is not
2104 determined through e.g. bootp.
2105 (Environment variable "ipaddr")
2107 - Server IP address:
2110 Defines a default value for the IP address of a TFTP
2111 server to contact when using the "tftboot" command.
2112 (Environment variable "serverip")
2114 CONFIG_KEEP_SERVERADDR
2116 Keeps the server's MAC address, in the env 'serveraddr'
2117 for passing to bootargs (like Linux's netconsole option)
2119 - Gateway IP address:
2122 Defines a default value for the IP address of the
2123 default router where packets to other networks are
2125 (Environment variable "gatewayip")
2130 Defines a default value for the subnet mask (or
2131 routing prefix) which is used to determine if an IP
2132 address belongs to the local subnet or needs to be
2133 forwarded through a router.
2134 (Environment variable "netmask")
2136 - Multicast TFTP Mode:
2139 Defines whether you want to support multicast TFTP as per
2140 rfc-2090; for example to work with atftp. Lets lots of targets
2141 tftp down the same boot image concurrently. Note: the Ethernet
2142 driver in use must provide a function: mcast() to join/leave a
2145 - BOOTP Recovery Mode:
2146 CONFIG_BOOTP_RANDOM_DELAY
2148 If you have many targets in a network that try to
2149 boot using BOOTP, you may want to avoid that all
2150 systems send out BOOTP requests at precisely the same
2151 moment (which would happen for instance at recovery
2152 from a power failure, when all systems will try to
2153 boot, thus flooding the BOOTP server. Defining
2154 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
2155 inserted before sending out BOOTP requests. The
2156 following delays are inserted then:
2158 1st BOOTP request: delay 0 ... 1 sec
2159 2nd BOOTP request: delay 0 ... 2 sec
2160 3rd BOOTP request: delay 0 ... 4 sec
2162 BOOTP requests: delay 0 ... 8 sec
2164 CONFIG_BOOTP_ID_CACHE_SIZE
2166 BOOTP packets are uniquely identified using a 32-bit ID. The
2167 server will copy the ID from client requests to responses and
2168 U-Boot will use this to determine if it is the destination of
2169 an incoming response. Some servers will check that addresses
2170 aren't in use before handing them out (usually using an ARP
2171 ping) and therefore take up to a few hundred milliseconds to
2172 respond. Network congestion may also influence the time it
2173 takes for a response to make it back to the client. If that
2174 time is too long, U-Boot will retransmit requests. In order
2175 to allow earlier responses to still be accepted after these
2176 retransmissions, U-Boot's BOOTP client keeps a small cache of
2177 IDs. The CONFIG_BOOTP_ID_CACHE_SIZE controls the size of this
2178 cache. The default is to keep IDs for up to four outstanding
2179 requests. Increasing this will allow U-Boot to accept offers
2180 from a BOOTP client in networks with unusually high latency.
2182 - BOOTP Random transaction ID:
2183 CONFIG_BOOTP_RANDOM_ID
2185 The standard algorithm to generate a DHCP/BOOTP transaction ID
2186 by using the MAC address and the current time stamp may not
2187 quite unlikely produce duplicate transaction IDs from different
2188 clients in the same network. This option creates a transaction
2189 ID using the rand() function. Provided that the RNG has been
2190 seeded well, this should guarantee unique transaction IDs
2193 - DHCP Advanced Options:
2194 You can fine tune the DHCP functionality by defining
2195 CONFIG_BOOTP_* symbols:
2197 CONFIG_BOOTP_SUBNETMASK
2198 CONFIG_BOOTP_GATEWAY
2199 CONFIG_BOOTP_HOSTNAME
2200 CONFIG_BOOTP_NISDOMAIN
2201 CONFIG_BOOTP_BOOTPATH
2202 CONFIG_BOOTP_BOOTFILESIZE
2205 CONFIG_BOOTP_SEND_HOSTNAME
2206 CONFIG_BOOTP_NTPSERVER
2207 CONFIG_BOOTP_TIMEOFFSET
2208 CONFIG_BOOTP_VENDOREX
2209 CONFIG_BOOTP_MAY_FAIL
2211 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip
2212 environment variable, not the BOOTP server.
2214 CONFIG_BOOTP_MAY_FAIL - If the DHCP server is not found
2215 after the configured retry count, the call will fail
2216 instead of starting over. This can be used to fail over
2217 to Link-local IP address configuration if the DHCP server
2220 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS
2221 serverip from a DHCP server, it is possible that more
2222 than one DNS serverip is offered to the client.
2223 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS
2224 serverip will be stored in the additional environment
2225 variable "dnsip2". The first DNS serverip is always
2226 stored in the variable "dnsip", when CONFIG_BOOTP_DNS
2229 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable
2230 to do a dynamic update of a DNS server. To do this, they
2231 need the hostname of the DHCP requester.
2232 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content
2233 of the "hostname" environment variable is passed as
2234 option 12 to the DHCP server.
2236 CONFIG_BOOTP_DHCP_REQUEST_DELAY
2238 A 32bit value in microseconds for a delay between
2239 receiving a "DHCP Offer" and sending the "DHCP Request".
2240 This fixes a problem with certain DHCP servers that don't
2241 respond 100% of the time to a "DHCP request". E.g. On an
2242 AT91RM9200 processor running at 180MHz, this delay needed
2243 to be *at least* 15,000 usec before a Windows Server 2003
2244 DHCP server would reply 100% of the time. I recommend at
2245 least 50,000 usec to be safe. The alternative is to hope
2246 that one of the retries will be successful but note that
2247 the DHCP timeout and retry process takes a longer than
2250 - Link-local IP address negotiation:
2251 Negotiate with other link-local clients on the local network
2252 for an address that doesn't require explicit configuration.
2253 This is especially useful if a DHCP server cannot be guaranteed
2254 to exist in all environments that the device must operate.
2256 See doc/README.link-local for more information.
2259 CONFIG_CDP_DEVICE_ID
2261 The device id used in CDP trigger frames.
2263 CONFIG_CDP_DEVICE_ID_PREFIX
2265 A two character string which is prefixed to the MAC address
2270 A printf format string which contains the ascii name of
2271 the port. Normally is set to "eth%d" which sets
2272 eth0 for the first Ethernet, eth1 for the second etc.
2274 CONFIG_CDP_CAPABILITIES
2276 A 32bit integer which indicates the device capabilities;
2277 0x00000010 for a normal host which does not forwards.
2281 An ascii string containing the version of the software.
2285 An ascii string containing the name of the platform.
2289 A 32bit integer sent on the trigger.
2291 CONFIG_CDP_POWER_CONSUMPTION
2293 A 16bit integer containing the power consumption of the
2294 device in .1 of milliwatts.
2296 CONFIG_CDP_APPLIANCE_VLAN_TYPE
2298 A byte containing the id of the VLAN.
2300 - Status LED: CONFIG_STATUS_LED
2302 Several configurations allow to display the current
2303 status using a LED. For instance, the LED will blink
2304 fast while running U-Boot code, stop blinking as
2305 soon as a reply to a BOOTP request was received, and
2306 start blinking slow once the Linux kernel is running
2307 (supported by a status LED driver in the Linux
2308 kernel). Defining CONFIG_STATUS_LED enables this
2314 The status LED can be connected to a GPIO pin.
2315 In such cases, the gpio_led driver can be used as a
2316 status LED backend implementation. Define CONFIG_GPIO_LED
2317 to include the gpio_led driver in the U-Boot binary.
2319 CONFIG_GPIO_LED_INVERTED_TABLE
2320 Some GPIO connected LEDs may have inverted polarity in which
2321 case the GPIO high value corresponds to LED off state and
2322 GPIO low value corresponds to LED on state.
2323 In such cases CONFIG_GPIO_LED_INVERTED_TABLE may be defined
2324 with a list of GPIO LEDs that have inverted polarity.
2326 - CAN Support: CONFIG_CAN_DRIVER
2328 Defining CONFIG_CAN_DRIVER enables CAN driver support
2329 on those systems that support this (optional)
2330 feature, like the TQM8xxL modules.
2332 - I2C Support: CONFIG_SYS_I2C
2334 This enable the NEW i2c subsystem, and will allow you to use
2335 i2c commands at the u-boot command line (as long as you set
2336 CONFIG_CMD_I2C in CONFIG_COMMANDS) and communicate with i2c
2337 based realtime clock chips or other i2c devices. See
2338 common/cmd_i2c.c for a description of the command line
2341 ported i2c driver to the new framework:
2342 - drivers/i2c/soft_i2c.c:
2343 - activate first bus with CONFIG_SYS_I2C_SOFT define
2344 CONFIG_SYS_I2C_SOFT_SPEED and CONFIG_SYS_I2C_SOFT_SLAVE
2345 for defining speed and slave address
2346 - activate second bus with I2C_SOFT_DECLARATIONS2 define
2347 CONFIG_SYS_I2C_SOFT_SPEED_2 and CONFIG_SYS_I2C_SOFT_SLAVE_2
2348 for defining speed and slave address
2349 - activate third bus with I2C_SOFT_DECLARATIONS3 define
2350 CONFIG_SYS_I2C_SOFT_SPEED_3 and CONFIG_SYS_I2C_SOFT_SLAVE_3
2351 for defining speed and slave address
2352 - activate fourth bus with I2C_SOFT_DECLARATIONS4 define
2353 CONFIG_SYS_I2C_SOFT_SPEED_4 and CONFIG_SYS_I2C_SOFT_SLAVE_4
2354 for defining speed and slave address
2356 - drivers/i2c/fsl_i2c.c:
2357 - activate i2c driver with CONFIG_SYS_I2C_FSL
2358 define CONFIG_SYS_FSL_I2C_OFFSET for setting the register
2359 offset CONFIG_SYS_FSL_I2C_SPEED for the i2c speed and
2360 CONFIG_SYS_FSL_I2C_SLAVE for the slave addr of the first
2362 - If your board supports a second fsl i2c bus, define
2363 CONFIG_SYS_FSL_I2C2_OFFSET for the register offset
2364 CONFIG_SYS_FSL_I2C2_SPEED for the speed and
2365 CONFIG_SYS_FSL_I2C2_SLAVE for the slave address of the
2368 - drivers/i2c/tegra_i2c.c:
2369 - activate this driver with CONFIG_SYS_I2C_TEGRA
2370 - This driver adds 4 i2c buses with a fix speed from
2371 100000 and the slave addr 0!
2373 - drivers/i2c/ppc4xx_i2c.c
2374 - activate this driver with CONFIG_SYS_I2C_PPC4XX
2375 - CONFIG_SYS_I2C_PPC4XX_CH0 activate hardware channel 0
2376 - CONFIG_SYS_I2C_PPC4XX_CH1 activate hardware channel 1
2378 - drivers/i2c/i2c_mxc.c
2379 - activate this driver with CONFIG_SYS_I2C_MXC
2380 - define speed for bus 1 with CONFIG_SYS_MXC_I2C1_SPEED
2381 - define slave for bus 1 with CONFIG_SYS_MXC_I2C1_SLAVE
2382 - define speed for bus 2 with CONFIG_SYS_MXC_I2C2_SPEED
2383 - define slave for bus 2 with CONFIG_SYS_MXC_I2C2_SLAVE
2384 - define speed for bus 3 with CONFIG_SYS_MXC_I2C3_SPEED
2385 - define slave for bus 3 with CONFIG_SYS_MXC_I2C3_SLAVE
2386 If those defines are not set, default value is 100000
2387 for speed, and 0 for slave.
2389 - drivers/i2c/rcar_i2c.c:
2390 - activate this driver with CONFIG_SYS_I2C_RCAR
2391 - This driver adds 4 i2c buses
2393 - CONFIG_SYS_RCAR_I2C0_BASE for setting the register channel 0
2394 - CONFIG_SYS_RCAR_I2C0_SPEED for for the speed channel 0
2395 - CONFIG_SYS_RCAR_I2C1_BASE for setting the register channel 1
2396 - CONFIG_SYS_RCAR_I2C1_SPEED for for the speed channel 1
2397 - CONFIG_SYS_RCAR_I2C2_BASE for setting the register channel 2
2398 - CONFIG_SYS_RCAR_I2C2_SPEED for for the speed channel 2
2399 - CONFIG_SYS_RCAR_I2C3_BASE for setting the register channel 3
2400 - CONFIG_SYS_RCAR_I2C3_SPEED for for the speed channel 3
2401 - CONFIF_SYS_RCAR_I2C_NUM_CONTROLLERS for number of i2c buses
2403 - drivers/i2c/sh_i2c.c:
2404 - activate this driver with CONFIG_SYS_I2C_SH
2405 - This driver adds from 2 to 5 i2c buses
2407 - CONFIG_SYS_I2C_SH_BASE0 for setting the register channel 0
2408 - CONFIG_SYS_I2C_SH_SPEED0 for for the speed channel 0
2409 - CONFIG_SYS_I2C_SH_BASE1 for setting the register channel 1
2410 - CONFIG_SYS_I2C_SH_SPEED1 for for the speed channel 1
2411 - CONFIG_SYS_I2C_SH_BASE2 for setting the register channel 2
2412 - CONFIG_SYS_I2C_SH_SPEED2 for for the speed channel 2
2413 - CONFIG_SYS_I2C_SH_BASE3 for setting the register channel 3
2414 - CONFIG_SYS_I2C_SH_SPEED3 for for the speed channel 3
2415 - CONFIG_SYS_I2C_SH_BASE4 for setting the register channel 4
2416 - CONFIG_SYS_I2C_SH_SPEED4 for for the speed channel 4
2417 - CONFIG_SYS_I2C_SH_BASE5 for setting the register channel 5
2418 - CONFIG_SYS_I2C_SH_SPEED5 for for the speed channel 5
2419 - CONFIG_SYS_I2C_SH_NUM_CONTROLLERS for number of i2c buses
2421 - drivers/i2c/omap24xx_i2c.c
2422 - activate this driver with CONFIG_SYS_I2C_OMAP24XX
2423 - CONFIG_SYS_OMAP24_I2C_SPEED speed channel 0
2424 - CONFIG_SYS_OMAP24_I2C_SLAVE slave addr channel 0
2425 - CONFIG_SYS_OMAP24_I2C_SPEED1 speed channel 1
2426 - CONFIG_SYS_OMAP24_I2C_SLAVE1 slave addr channel 1
2427 - CONFIG_SYS_OMAP24_I2C_SPEED2 speed channel 2
2428 - CONFIG_SYS_OMAP24_I2C_SLAVE2 slave addr channel 2
2429 - CONFIG_SYS_OMAP24_I2C_SPEED3 speed channel 3
2430 - CONFIG_SYS_OMAP24_I2C_SLAVE3 slave addr channel 3
2431 - CONFIG_SYS_OMAP24_I2C_SPEED4 speed channel 4
2432 - CONFIG_SYS_OMAP24_I2C_SLAVE4 slave addr channel 4
2434 - drivers/i2c/zynq_i2c.c
2435 - activate this driver with CONFIG_SYS_I2C_ZYNQ
2436 - set CONFIG_SYS_I2C_ZYNQ_SPEED for speed setting
2437 - set CONFIG_SYS_I2C_ZYNQ_SLAVE for slave addr
2439 - drivers/i2c/s3c24x0_i2c.c:
2440 - activate this driver with CONFIG_SYS_I2C_S3C24X0
2441 - This driver adds i2c buses (11 for Exynos5250, Exynos5420
2442 9 i2c buses for Exynos4 and 1 for S3C24X0 SoCs from Samsung)
2443 with a fix speed from 100000 and the slave addr 0!
2445 - drivers/i2c/ihs_i2c.c
2446 - activate this driver with CONFIG_SYS_I2C_IHS
2447 - CONFIG_SYS_I2C_IHS_CH0 activate hardware channel 0
2448 - CONFIG_SYS_I2C_IHS_SPEED_0 speed channel 0
2449 - CONFIG_SYS_I2C_IHS_SLAVE_0 slave addr channel 0
2450 - CONFIG_SYS_I2C_IHS_CH1 activate hardware channel 1
2451 - CONFIG_SYS_I2C_IHS_SPEED_1 speed channel 1
2452 - CONFIG_SYS_I2C_IHS_SLAVE_1 slave addr channel 1
2453 - CONFIG_SYS_I2C_IHS_CH2 activate hardware channel 2
2454 - CONFIG_SYS_I2C_IHS_SPEED_2 speed channel 2
2455 - CONFIG_SYS_I2C_IHS_SLAVE_2 slave addr channel 2
2456 - CONFIG_SYS_I2C_IHS_CH3 activate hardware channel 3
2457 - CONFIG_SYS_I2C_IHS_SPEED_3 speed channel 3
2458 - CONFIG_SYS_I2C_IHS_SLAVE_3 slave addr channel 3
2462 CONFIG_SYS_NUM_I2C_BUSES
2463 Hold the number of i2c buses you want to use. If you
2464 don't use/have i2c muxes on your i2c bus, this
2465 is equal to CONFIG_SYS_NUM_I2C_ADAPTERS, and you can
2468 CONFIG_SYS_I2C_DIRECT_BUS
2469 define this, if you don't use i2c muxes on your hardware.
2470 if CONFIG_SYS_I2C_MAX_HOPS is not defined or == 0 you can
2473 CONFIG_SYS_I2C_MAX_HOPS
2474 define how many muxes are maximal consecutively connected
2475 on one i2c bus. If you not use i2c muxes, omit this
2478 CONFIG_SYS_I2C_BUSES
2479 hold a list of buses you want to use, only used if
2480 CONFIG_SYS_I2C_DIRECT_BUS is not defined, for example
2481 a board with CONFIG_SYS_I2C_MAX_HOPS = 1 and
2482 CONFIG_SYS_NUM_I2C_BUSES = 9:
2484 CONFIG_SYS_I2C_BUSES {{0, {I2C_NULL_HOP}}, \
2485 {0, {{I2C_MUX_PCA9547, 0x70, 1}}}, \
2486 {0, {{I2C_MUX_PCA9547, 0x70, 2}}}, \
2487 {0, {{I2C_MUX_PCA9547, 0x70, 3}}}, \
2488 {0, {{I2C_MUX_PCA9547, 0x70, 4}}}, \
2489 {0, {{I2C_MUX_PCA9547, 0x70, 5}}}, \
2490 {1, {I2C_NULL_HOP}}, \
2491 {1, {{I2C_MUX_PCA9544, 0x72, 1}}}, \
2492 {1, {{I2C_MUX_PCA9544, 0x72, 2}}}, \
2496 bus 0 on adapter 0 without a mux
2497 bus 1 on adapter 0 with a PCA9547 on address 0x70 port 1
2498 bus 2 on adapter 0 with a PCA9547 on address 0x70 port 2
2499 bus 3 on adapter 0 with a PCA9547 on address 0x70 port 3
2500 bus 4 on adapter 0 with a PCA9547 on address 0x70 port 4
2501 bus 5 on adapter 0 with a PCA9547 on address 0x70 port 5
2502 bus 6 on adapter 1 without a mux
2503 bus 7 on adapter 1 with a PCA9544 on address 0x72 port 1
2504 bus 8 on adapter 1 with a PCA9544 on address 0x72 port 2
2506 If you do not have i2c muxes on your board, omit this define.
2508 - Legacy I2C Support: CONFIG_HARD_I2C
2510 NOTE: It is intended to move drivers to CONFIG_SYS_I2C which
2511 provides the following compelling advantages:
2513 - more than one i2c adapter is usable
2514 - approved multibus support
2515 - better i2c mux support
2517 ** Please consider updating your I2C driver now. **
2519 These enable legacy I2C serial bus commands. Defining
2520 CONFIG_HARD_I2C will include the appropriate I2C driver
2521 for the selected CPU.
2523 This will allow you to use i2c commands at the u-boot
2524 command line (as long as you set CONFIG_CMD_I2C in
2525 CONFIG_COMMANDS) and communicate with i2c based realtime
2526 clock chips. See common/cmd_i2c.c for a description of the
2527 command line interface.
2529 CONFIG_HARD_I2C selects a hardware I2C controller.
2531 There are several other quantities that must also be
2532 defined when you define CONFIG_HARD_I2C.
2534 In both cases you will need to define CONFIG_SYS_I2C_SPEED
2535 to be the frequency (in Hz) at which you wish your i2c bus
2536 to run and CONFIG_SYS_I2C_SLAVE to be the address of this node (ie
2537 the CPU's i2c node address).
2539 Now, the u-boot i2c code for the mpc8xx
2540 (arch/powerpc/cpu/mpc8xx/i2c.c) sets the CPU up as a master node
2541 and so its address should therefore be cleared to 0 (See,
2542 eg, MPC823e User's Manual p.16-473). So, set
2543 CONFIG_SYS_I2C_SLAVE to 0.
2545 CONFIG_SYS_I2C_INIT_MPC5XXX
2547 When a board is reset during an i2c bus transfer
2548 chips might think that the current transfer is still
2549 in progress. Reset the slave devices by sending start
2550 commands until the slave device responds.
2552 That's all that's required for CONFIG_HARD_I2C.
2554 If you use the software i2c interface (CONFIG_SYS_I2C_SOFT)
2555 then the following macros need to be defined (examples are
2556 from include/configs/lwmon.h):
2560 (Optional). Any commands necessary to enable the I2C
2561 controller or configure ports.
2563 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
2567 (Only for MPC8260 CPU). The I/O port to use (the code
2568 assumes both bits are on the same port). Valid values
2569 are 0..3 for ports A..D.
2573 The code necessary to make the I2C data line active
2574 (driven). If the data line is open collector, this
2577 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
2581 The code necessary to make the I2C data line tri-stated
2582 (inactive). If the data line is open collector, this
2585 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
2589 Code that returns true if the I2C data line is high,
2592 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
2596 If <bit> is true, sets the I2C data line high. If it
2597 is false, it clears it (low).
2599 eg: #define I2C_SDA(bit) \
2600 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
2601 else immr->im_cpm.cp_pbdat &= ~PB_SDA
2605 If <bit> is true, sets the I2C clock line high. If it
2606 is false, it clears it (low).
2608 eg: #define I2C_SCL(bit) \
2609 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
2610 else immr->im_cpm.cp_pbdat &= ~PB_SCL
2614 This delay is invoked four times per clock cycle so this
2615 controls the rate of data transfer. The data rate thus
2616 is 1 / (I2C_DELAY * 4). Often defined to be something
2619 #define I2C_DELAY udelay(2)
2621 CONFIG_SOFT_I2C_GPIO_SCL / CONFIG_SOFT_I2C_GPIO_SDA
2623 If your arch supports the generic GPIO framework (asm/gpio.h),
2624 then you may alternatively define the two GPIOs that are to be
2625 used as SCL / SDA. Any of the previous I2C_xxx macros will
2626 have GPIO-based defaults assigned to them as appropriate.
2628 You should define these to the GPIO value as given directly to
2629 the generic GPIO functions.
2631 CONFIG_SYS_I2C_INIT_BOARD
2633 When a board is reset during an i2c bus transfer
2634 chips might think that the current transfer is still
2635 in progress. On some boards it is possible to access
2636 the i2c SCLK line directly, either by using the
2637 processor pin as a GPIO or by having a second pin
2638 connected to the bus. If this option is defined a
2639 custom i2c_init_board() routine in boards/xxx/board.c
2640 is run early in the boot sequence.
2642 CONFIG_SYS_I2C_BOARD_LATE_INIT
2644 An alternative to CONFIG_SYS_I2C_INIT_BOARD. If this option is
2645 defined a custom i2c_board_late_init() routine in
2646 boards/xxx/board.c is run AFTER the operations in i2c_init()
2647 is completed. This callpoint can be used to unreset i2c bus
2648 using CPU i2c controller register accesses for CPUs whose i2c
2649 controller provide such a method. It is called at the end of
2650 i2c_init() to allow i2c_init operations to setup the i2c bus
2651 controller on the CPU (e.g. setting bus speed & slave address).
2653 CONFIG_I2CFAST (PPC405GP|PPC405EP only)
2655 This option enables configuration of bi_iic_fast[] flags
2656 in u-boot bd_info structure based on u-boot environment
2657 variable "i2cfast". (see also i2cfast)
2659 CONFIG_I2C_MULTI_BUS
2661 This option allows the use of multiple I2C buses, each of which
2662 must have a controller. At any point in time, only one bus is
2663 active. To switch to a different bus, use the 'i2c dev' command.
2664 Note that bus numbering is zero-based.
2666 CONFIG_SYS_I2C_NOPROBES
2668 This option specifies a list of I2C devices that will be skipped
2669 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS
2670 is set, specify a list of bus-device pairs. Otherwise, specify
2671 a 1D array of device addresses
2674 #undef CONFIG_I2C_MULTI_BUS
2675 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68}
2677 will skip addresses 0x50 and 0x68 on a board with one I2C bus
2679 #define CONFIG_I2C_MULTI_BUS
2680 #define CONFIG_SYS_I2C_MULTI_NOPROBES {{0,0x50},{0,0x68},{1,0x54}}
2682 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1
2684 CONFIG_SYS_SPD_BUS_NUM
2686 If defined, then this indicates the I2C bus number for DDR SPD.
2687 If not defined, then U-Boot assumes that SPD is on I2C bus 0.
2689 CONFIG_SYS_RTC_BUS_NUM
2691 If defined, then this indicates the I2C bus number for the RTC.
2692 If not defined, then U-Boot assumes that RTC is on I2C bus 0.
2694 CONFIG_SYS_DTT_BUS_NUM
2696 If defined, then this indicates the I2C bus number for the DTT.
2697 If not defined, then U-Boot assumes that DTT is on I2C bus 0.
2699 CONFIG_SYS_I2C_DTT_ADDR:
2701 If defined, specifies the I2C address of the DTT device.
2702 If not defined, then U-Boot uses predefined value for
2703 specified DTT device.
2705 CONFIG_SOFT_I2C_READ_REPEATED_START
2707 defining this will force the i2c_read() function in
2708 the soft_i2c driver to perform an I2C repeated start
2709 between writing the address pointer and reading the
2710 data. If this define is omitted the default behaviour
2711 of doing a stop-start sequence will be used. Most I2C
2712 devices can use either method, but some require one or
2715 - SPI Support: CONFIG_SPI
2717 Enables SPI driver (so far only tested with
2718 SPI EEPROM, also an instance works with Crystal A/D and
2719 D/As on the SACSng board)
2723 Enables the driver for SPI controller on SuperH. Currently
2724 only SH7757 is supported.
2728 Enables extended (16-bit) SPI EEPROM addressing.
2729 (symmetrical to CONFIG_I2C_X)
2733 Enables a software (bit-bang) SPI driver rather than
2734 using hardware support. This is a general purpose
2735 driver that only requires three general I/O port pins
2736 (two outputs, one input) to function. If this is
2737 defined, the board configuration must define several
2738 SPI configuration items (port pins to use, etc). For
2739 an example, see include/configs/sacsng.h.
2743 Enables a hardware SPI driver for general-purpose reads
2744 and writes. As with CONFIG_SOFT_SPI, the board configuration
2745 must define a list of chip-select function pointers.
2746 Currently supported on some MPC8xxx processors. For an
2747 example, see include/configs/mpc8349emds.h.
2751 Enables the driver for the SPI controllers on i.MX and MXC
2752 SoCs. Currently i.MX31/35/51 are supported.
2754 CONFIG_SYS_SPI_MXC_WAIT
2755 Timeout for waiting until spi transfer completed.
2756 default: (CONFIG_SYS_HZ/100) /* 10 ms */
2758 - FPGA Support: CONFIG_FPGA
2760 Enables FPGA subsystem.
2762 CONFIG_FPGA_<vendor>
2764 Enables support for specific chip vendors.
2767 CONFIG_FPGA_<family>
2769 Enables support for FPGA family.
2770 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX)
2774 Specify the number of FPGA devices to support.
2776 CONFIG_CMD_FPGA_LOADMK
2778 Enable support for fpga loadmk command
2780 CONFIG_CMD_FPGA_LOADP
2782 Enable support for fpga loadp command - load partial bitstream
2784 CONFIG_CMD_FPGA_LOADBP
2786 Enable support for fpga loadbp command - load partial bitstream
2789 CONFIG_SYS_FPGA_PROG_FEEDBACK
2791 Enable printing of hash marks during FPGA configuration.
2793 CONFIG_SYS_FPGA_CHECK_BUSY
2795 Enable checks on FPGA configuration interface busy
2796 status by the configuration function. This option
2797 will require a board or device specific function to
2802 If defined, a function that provides delays in the FPGA
2803 configuration driver.
2805 CONFIG_SYS_FPGA_CHECK_CTRLC
2806 Allow Control-C to interrupt FPGA configuration
2808 CONFIG_SYS_FPGA_CHECK_ERROR
2810 Check for configuration errors during FPGA bitfile
2811 loading. For example, abort during Virtex II
2812 configuration if the INIT_B line goes low (which
2813 indicated a CRC error).
2815 CONFIG_SYS_FPGA_WAIT_INIT
2817 Maximum time to wait for the INIT_B line to de-assert
2818 after PROB_B has been de-asserted during a Virtex II
2819 FPGA configuration sequence. The default time is 500
2822 CONFIG_SYS_FPGA_WAIT_BUSY
2824 Maximum time to wait for BUSY to de-assert during
2825 Virtex II FPGA configuration. The default is 5 ms.
2827 CONFIG_SYS_FPGA_WAIT_CONFIG
2829 Time to wait after FPGA configuration. The default is
2832 - Configuration Management:
2835 Some SoCs need special image types (e.g. U-Boot binary
2836 with a special header) as build targets. By defining
2837 CONFIG_BUILD_TARGET in the SoC / board header, this
2838 special image will be automatically built upon calling
2843 If defined, this string will be added to the U-Boot
2844 version information (U_BOOT_VERSION)
2846 - Vendor Parameter Protection:
2848 U-Boot considers the values of the environment
2849 variables "serial#" (Board Serial Number) and
2850 "ethaddr" (Ethernet Address) to be parameters that
2851 are set once by the board vendor / manufacturer, and
2852 protects these variables from casual modification by
2853 the user. Once set, these variables are read-only,
2854 and write or delete attempts are rejected. You can
2855 change this behaviour:
2857 If CONFIG_ENV_OVERWRITE is #defined in your config
2858 file, the write protection for vendor parameters is
2859 completely disabled. Anybody can change or delete
2862 Alternatively, if you #define _both_ CONFIG_ETHADDR
2863 _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
2864 Ethernet address is installed in the environment,
2865 which can be changed exactly ONCE by the user. [The
2866 serial# is unaffected by this, i. e. it remains
2869 The same can be accomplished in a more flexible way
2870 for any variable by configuring the type of access
2871 to allow for those variables in the ".flags" variable
2872 or define CONFIG_ENV_FLAGS_LIST_STATIC.
2877 Define this variable to enable the reservation of
2878 "protected RAM", i. e. RAM which is not overwritten
2879 by U-Boot. Define CONFIG_PRAM to hold the number of
2880 kB you want to reserve for pRAM. You can overwrite
2881 this default value by defining an environment
2882 variable "pram" to the number of kB you want to
2883 reserve. Note that the board info structure will
2884 still show the full amount of RAM. If pRAM is
2885 reserved, a new environment variable "mem" will
2886 automatically be defined to hold the amount of
2887 remaining RAM in a form that can be passed as boot
2888 argument to Linux, for instance like that:
2890 setenv bootargs ... mem=\${mem}
2893 This way you can tell Linux not to use this memory,
2894 either, which results in a memory region that will
2895 not be affected by reboots.
2897 *WARNING* If your board configuration uses automatic
2898 detection of the RAM size, you must make sure that
2899 this memory test is non-destructive. So far, the
2900 following board configurations are known to be
2903 IVMS8, IVML24, SPD8xx, TQM8xxL,
2904 HERMES, IP860, RPXlite, LWMON,
2907 - Access to physical memory region (> 4GB)
2908 Some basic support is provided for operations on memory not
2909 normally accessible to U-Boot - e.g. some architectures
2910 support access to more than 4GB of memory on 32-bit
2911 machines using physical address extension or similar.
2912 Define CONFIG_PHYSMEM to access this basic support, which
2913 currently only supports clearing the memory.
2918 Define this variable to stop the system in case of a
2919 fatal error, so that you have to reset it manually.
2920 This is probably NOT a good idea for an embedded
2921 system where you want the system to reboot
2922 automatically as fast as possible, but it may be
2923 useful during development since you can try to debug
2924 the conditions that lead to the situation.
2926 CONFIG_NET_RETRY_COUNT
2928 This variable defines the number of retries for
2929 network operations like ARP, RARP, TFTP, or BOOTP
2930 before giving up the operation. If not defined, a
2931 default value of 5 is used.
2935 Timeout waiting for an ARP reply in milliseconds.
2939 Timeout in milliseconds used in NFS protocol.
2940 If you encounter "ERROR: Cannot umount" in nfs command,
2941 try longer timeout such as
2942 #define CONFIG_NFS_TIMEOUT 10000UL
2944 - Command Interpreter:
2945 CONFIG_AUTO_COMPLETE
2947 Enable auto completion of commands using TAB.
2949 CONFIG_SYS_PROMPT_HUSH_PS2
2951 This defines the secondary prompt string, which is
2952 printed when the command interpreter needs more input
2953 to complete a command. Usually "> ".
2957 In the current implementation, the local variables
2958 space and global environment variables space are
2959 separated. Local variables are those you define by
2960 simply typing `name=value'. To access a local
2961 variable later on, you have write `$name' or
2962 `${name}'; to execute the contents of a variable
2963 directly type `$name' at the command prompt.
2965 Global environment variables are those you use
2966 setenv/printenv to work with. To run a command stored
2967 in such a variable, you need to use the run command,
2968 and you must not use the '$' sign to access them.
2970 To store commands and special characters in a
2971 variable, please use double quotation marks
2972 surrounding the whole text of the variable, instead
2973 of the backslashes before semicolons and special
2976 - Command Line Editing and History:
2977 CONFIG_CMDLINE_EDITING
2979 Enable editing and History functions for interactive
2980 command line input operations
2982 - Default Environment:
2983 CONFIG_EXTRA_ENV_SETTINGS
2985 Define this to contain any number of null terminated
2986 strings (variable = value pairs) that will be part of
2987 the default environment compiled into the boot image.
2989 For example, place something like this in your
2990 board's config file:
2992 #define CONFIG_EXTRA_ENV_SETTINGS \
2996 Warning: This method is based on knowledge about the
2997 internal format how the environment is stored by the
2998 U-Boot code. This is NOT an official, exported
2999 interface! Although it is unlikely that this format
3000 will change soon, there is no guarantee either.
3001 You better know what you are doing here.
3003 Note: overly (ab)use of the default environment is
3004 discouraged. Make sure to check other ways to preset
3005 the environment like the "source" command or the
3008 CONFIG_ENV_VARS_UBOOT_CONFIG
3010 Define this in order to add variables describing the
3011 U-Boot build configuration to the default environment.
3012 These will be named arch, cpu, board, vendor, and soc.
3014 Enabling this option will cause the following to be defined:
3022 CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG
3024 Define this in order to add variables describing certain
3025 run-time determined information about the hardware to the
3026 environment. These will be named board_name, board_rev.
3028 CONFIG_DELAY_ENVIRONMENT
3030 Normally the environment is loaded when the board is
3031 initialised so that it is available to U-Boot. This inhibits
3032 that so that the environment is not available until
3033 explicitly loaded later by U-Boot code. With CONFIG_OF_CONTROL
3034 this is instead controlled by the value of
3035 /config/load-environment.
3037 - DataFlash Support:
3038 CONFIG_HAS_DATAFLASH
3040 Defining this option enables DataFlash features and
3041 allows to read/write in Dataflash via the standard
3044 - Serial Flash support
3047 Defining this option enables SPI flash commands
3048 'sf probe/read/write/erase/update'.
3050 Usage requires an initial 'probe' to define the serial
3051 flash parameters, followed by read/write/erase/update
3054 The following defaults may be provided by the platform
3055 to handle the common case when only a single serial
3056 flash is present on the system.
3058 CONFIG_SF_DEFAULT_BUS Bus identifier
3059 CONFIG_SF_DEFAULT_CS Chip-select
3060 CONFIG_SF_DEFAULT_MODE (see include/spi.h)
3061 CONFIG_SF_DEFAULT_SPEED in Hz
3065 Define this option to include a destructive SPI flash
3068 CONFIG_SPI_FLASH_BAR Ban/Extended Addr Reg
3070 Define this option to use the Bank addr/Extended addr
3071 support on SPI flashes which has size > 16Mbytes.
3073 CONFIG_SF_DUAL_FLASH Dual flash memories
3075 Define this option to use dual flash support where two flash
3076 memories can be connected with a given cs line.
3077 Currently Xilinx Zynq qspi supports these type of connections.
3079 CONFIG_SYS_SPI_ST_ENABLE_WP_PIN
3080 enable the W#/Vpp signal to disable writing to the status
3081 register on ST MICRON flashes like the N25Q128.
3082 The status register write enable/disable bit, combined with
3083 the W#/VPP signal provides hardware data protection for the
3084 device as follows: When the enable/disable bit is set to 1,
3085 and the W#/VPP signal is driven LOW, the status register
3086 nonvolatile bits become read-only and the WRITE STATUS REGISTER
3087 operation will not execute. The only way to exit this
3088 hardware-protected mode is to drive W#/VPP HIGH.
3090 - SystemACE Support:
3093 Adding this option adds support for Xilinx SystemACE
3094 chips attached via some sort of local bus. The address
3095 of the chip must also be defined in the
3096 CONFIG_SYS_SYSTEMACE_BASE macro. For example:
3098 #define CONFIG_SYSTEMACE
3099 #define CONFIG_SYS_SYSTEMACE_BASE 0xf0000000
3101 When SystemACE support is added, the "ace" device type
3102 becomes available to the fat commands, i.e. fatls.
3104 - TFTP Fixed UDP Port:
3107 If this is defined, the environment variable tftpsrcp
3108 is used to supply the TFTP UDP source port value.
3109 If tftpsrcp isn't defined, the normal pseudo-random port
3110 number generator is used.
3112 Also, the environment variable tftpdstp is used to supply
3113 the TFTP UDP destination port value. If tftpdstp isn't
3114 defined, the normal port 69 is used.
3116 The purpose for tftpsrcp is to allow a TFTP server to
3117 blindly start the TFTP transfer using the pre-configured
3118 target IP address and UDP port. This has the effect of
3119 "punching through" the (Windows XP) firewall, allowing
3120 the remainder of the TFTP transfer to proceed normally.
3121 A better solution is to properly configure the firewall,
3122 but sometimes that is not allowed.
3127 This enables a generic 'hash' command which can produce
3128 hashes / digests from a few algorithms (e.g. SHA1, SHA256).
3132 Enable the hash verify command (hash -v). This adds to code
3135 CONFIG_SHA1 - This option enables support of hashing using SHA1
3136 algorithm. The hash is calculated in software.
3137 CONFIG_SHA256 - This option enables support of hashing using
3138 SHA256 algorithm. The hash is calculated in software.
3139 CONFIG_SHA_HW_ACCEL - This option enables hardware acceleration
3140 for SHA1/SHA256 hashing.
3141 This affects the 'hash' command and also the
3142 hash_lookup_algo() function.
3143 CONFIG_SHA_PROG_HW_ACCEL - This option enables
3144 hardware-acceleration for SHA1/SHA256 progressive hashing.
3145 Data can be streamed in a block at a time and the hashing
3146 is performed in hardware.
3148 Note: There is also a sha1sum command, which should perhaps
3149 be deprecated in favour of 'hash sha1'.
3151 - Freescale i.MX specific commands:
3152 CONFIG_CMD_HDMIDETECT
3153 This enables 'hdmidet' command which returns true if an
3154 HDMI monitor is detected. This command is i.MX 6 specific.
3157 This enables the 'bmode' (bootmode) command for forcing
3158 a boot from specific media.
3160 This is useful for forcing the ROM's usb downloader to
3161 activate upon a watchdog reset which is nice when iterating
3162 on U-Boot. Using the reset button or running bmode normal
3163 will set it back to normal. This command currently
3164 supports i.MX53 and i.MX6.
3169 This enables the RSA algorithm used for FIT image verification
3170 in U-Boot. See doc/uImage.FIT/signature.txt for more information.
3172 The Modular Exponentiation algorithm in RSA is implemented using
3173 driver model. So CONFIG_DM needs to be enabled by default for this
3174 library to function.
3176 The signing part is build into mkimage regardless of this
3177 option. The software based modular exponentiation is built into
3178 mkimage irrespective of this option.
3180 - bootcount support:
3181 CONFIG_BOOTCOUNT_LIMIT
3183 This enables the bootcounter support, see:
3184 http://www.denx.de/wiki/DULG/UBootBootCountLimit
3187 enable special bootcounter support on at91sam9xe based boards.
3189 enable special bootcounter support on blackfin based boards.
3191 enable special bootcounter support on da850 based boards.
3192 CONFIG_BOOTCOUNT_RAM
3193 enable support for the bootcounter in RAM
3194 CONFIG_BOOTCOUNT_I2C
3195 enable support for the bootcounter on an i2c (like RTC) device.
3196 CONFIG_SYS_I2C_RTC_ADDR = i2c chip address
3197 CONFIG_SYS_BOOTCOUNT_ADDR = i2c addr which is used for
3199 CONFIG_BOOTCOUNT_ALEN = address len
3201 - Show boot progress:
3202 CONFIG_SHOW_BOOT_PROGRESS
3204 Defining this option allows to add some board-
3205 specific code (calling a user-provided function
3206 "show_boot_progress(int)") that enables you to show
3207 the system's boot progress on some display (for
3208 example, some LED's) on your board. At the moment,
3209 the following checkpoints are implemented:
3211 - Detailed boot stage timing
3213 Define this option to get detailed timing of each stage
3214 of the boot process.
3216 CONFIG_BOOTSTAGE_USER_COUNT
3217 This is the number of available user bootstage records.
3218 Each time you call bootstage_mark(BOOTSTAGE_ID_ALLOC, ...)
3219 a new ID will be allocated from this stash. If you exceed
3220 the limit, recording will stop.
3222 CONFIG_BOOTSTAGE_REPORT
3223 Define this to print a report before boot, similar to this:
3225 Timer summary in microseconds:
3228 3,575,678 3,575,678 board_init_f start
3229 3,575,695 17 arch_cpu_init A9
3230 3,575,777 82 arch_cpu_init done
3231 3,659,598 83,821 board_init_r start
3232 3,910,375 250,777 main_loop
3233 29,916,167 26,005,792 bootm_start
3234 30,361,327 445,160 start_kernel
3236 CONFIG_CMD_BOOTSTAGE
3237 Add a 'bootstage' command which supports printing a report
3238 and un/stashing of bootstage data.
3240 CONFIG_BOOTSTAGE_FDT
3241 Stash the bootstage information in the FDT. A root 'bootstage'
3242 node is created with each bootstage id as a child. Each child
3243 has a 'name' property and either 'mark' containing the
3244 mark time in microsecond, or 'accum' containing the
3245 accumulated time for that bootstage id in microseconds.
3250 name = "board_init_f";
3259 Code in the Linux kernel can find this in /proc/devicetree.
3261 Legacy uImage format:
3264 1 common/cmd_bootm.c before attempting to boot an image
3265 -1 common/cmd_bootm.c Image header has bad magic number
3266 2 common/cmd_bootm.c Image header has correct magic number
3267 -2 common/cmd_bootm.c Image header has bad checksum
3268 3 common/cmd_bootm.c Image header has correct checksum
3269 -3 common/cmd_bootm.c Image data has bad checksum
3270 4 common/cmd_bootm.c Image data has correct checksum
3271 -4 common/cmd_bootm.c Image is for unsupported architecture
3272 5 common/cmd_bootm.c Architecture check OK
3273 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi)
3274 6 common/cmd_bootm.c Image Type check OK
3275 -6 common/cmd_bootm.c gunzip uncompression error
3276 -7 common/cmd_bootm.c Unimplemented compression type
3277 7 common/cmd_bootm.c Uncompression OK
3278 8 common/cmd_bootm.c No uncompress/copy overwrite error
3279 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX)
3281 9 common/image.c Start initial ramdisk verification
3282 -10 common/image.c Ramdisk header has bad magic number
3283 -11 common/image.c Ramdisk header has bad checksum
3284 10 common/image.c Ramdisk header is OK
3285 -12 common/image.c Ramdisk data has bad checksum
3286 11 common/image.c Ramdisk data has correct checksum
3287 12 common/image.c Ramdisk verification complete, start loading
3288 -13 common/image.c Wrong Image Type (not PPC Linux ramdisk)
3289 13 common/image.c Start multifile image verification
3290 14 common/image.c No initial ramdisk, no multifile, continue.
3292 15 arch/<arch>/lib/bootm.c All preparation done, transferring control to OS
3294 -30 arch/powerpc/lib/board.c Fatal error, hang the system
3295 -31 post/post.c POST test failed, detected by post_output_backlog()
3296 -32 post/post.c POST test failed, detected by post_run_single()
3298 34 common/cmd_doc.c before loading a Image from a DOC device
3299 -35 common/cmd_doc.c Bad usage of "doc" command
3300 35 common/cmd_doc.c correct usage of "doc" command
3301 -36 common/cmd_doc.c No boot device
3302 36 common/cmd_doc.c correct boot device
3303 -37 common/cmd_doc.c Unknown Chip ID on boot device
3304 37 common/cmd_doc.c correct chip ID found, device available
3305 -38 common/cmd_doc.c Read Error on boot device
3306 38 common/cmd_doc.c reading Image header from DOC device OK
3307 -39 common/cmd_doc.c Image header has bad magic number
3308 39 common/cmd_doc.c Image header has correct magic number
3309 -40 common/cmd_doc.c Error reading Image from DOC device
3310 40 common/cmd_doc.c Image header has correct magic number
3311 41 common/cmd_ide.c before loading a Image from a IDE device
3312 -42 common/cmd_ide.c Bad usage of "ide" command
3313 42 common/cmd_ide.c correct usage of "ide" command
3314 -43 common/cmd_ide.c No boot device
3315 43 common/cmd_ide.c boot device found
3316 -44 common/cmd_ide.c Device not available
3317 44 common/cmd_ide.c Device available
3318 -45 common/cmd_ide.c wrong partition selected
3319 45 common/cmd_ide.c partition selected
3320 -46 common/cmd_ide.c Unknown partition table
3321 46 common/cmd_ide.c valid partition table found
3322 -47 common/cmd_ide.c Invalid partition type
3323 47 common/cmd_ide.c correct partition type
3324 -48 common/cmd_ide.c Error reading Image Header on boot device
3325 48 common/cmd_ide.c reading Image Header from IDE device OK
3326 -49 common/cmd_ide.c Image header has bad magic number
3327 49 common/cmd_ide.c Image header has correct magic number
3328 -50 common/cmd_ide.c Image header has bad checksum
3329 50 common/cmd_ide.c Image header has correct checksum
3330 -51 common/cmd_ide.c Error reading Image from IDE device
3331 51 common/cmd_ide.c reading Image from IDE device OK
3332 52 common/cmd_nand.c before loading a Image from a NAND device
3333 -53 common/cmd_nand.c Bad usage of "nand" command
3334 53 common/cmd_nand.c correct usage of "nand" command
3335 -54 common/cmd_nand.c No boot device
3336 54 common/cmd_nand.c boot device found
3337 -55 common/cmd_nand.c Unknown Chip ID on boot device
3338 55 common/cmd_nand.c correct chip ID found, device available
3339 -56 common/cmd_nand.c Error reading Image Header on boot device
3340 56 common/cmd_nand.c reading Image Header from NAND device OK
3341 -57 common/cmd_nand.c Image header has bad magic number
3342 57 common/cmd_nand.c Image header has correct magic number
3343 -58 common/cmd_nand.c Error reading Image from NAND device
3344 58 common/cmd_nand.c reading Image from NAND device OK
3346 -60 common/env_common.c Environment has a bad CRC, using default
3348 64 net/eth.c starting with Ethernet configuration.
3349 -64 net/eth.c no Ethernet found.
3350 65 net/eth.c Ethernet found.
3352 -80 common/cmd_net.c usage wrong
3353 80 common/cmd_net.c before calling NetLoop()
3354 -81 common/cmd_net.c some error in NetLoop() occurred
3355 81 common/cmd_net.c NetLoop() back without error
3356 -82 common/cmd_net.c size == 0 (File with size 0 loaded)
3357 82 common/cmd_net.c trying automatic boot
3358 83 common/cmd_net.c running "source" command
3359 -83 common/cmd_net.c some error in automatic boot or "source" command
3360 84 common/cmd_net.c end without errors
3365 100 common/cmd_bootm.c Kernel FIT Image has correct format
3366 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format
3367 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration
3368 -101 common/cmd_bootm.c Can't get configuration for kernel subimage
3369 102 common/cmd_bootm.c Kernel unit name specified
3370 -103 common/cmd_bootm.c Can't get kernel subimage node offset
3371 103 common/cmd_bootm.c Found configuration node
3372 104 common/cmd_bootm.c Got kernel subimage node offset
3373 -104 common/cmd_bootm.c Kernel subimage hash verification failed
3374 105 common/cmd_bootm.c Kernel subimage hash verification OK
3375 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture
3376 106 common/cmd_bootm.c Architecture check OK
3377 -106 common/cmd_bootm.c Kernel subimage has wrong type
3378 107 common/cmd_bootm.c Kernel subimage type OK
3379 -107 common/cmd_bootm.c Can't get kernel subimage data/size
3380 108 common/cmd_bootm.c Got kernel subimage data/size
3381 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT)
3382 -109 common/cmd_bootm.c Can't get kernel subimage type
3383 -110 common/cmd_bootm.c Can't get kernel subimage comp
3384 -111 common/cmd_bootm.c Can't get kernel subimage os
3385 -112 common/cmd_bootm.c Can't get kernel subimage load address
3386 -113 common/cmd_bootm.c Image uncompress/copy overwrite error
3388 120 common/image.c Start initial ramdisk verification
3389 -120 common/image.c Ramdisk FIT image has incorrect format
3390 121 common/image.c Ramdisk FIT image has correct format
3391 122 common/image.c No ramdisk subimage unit name, using configuration
3392 -122 common/image.c Can't get configuration for ramdisk subimage
3393 123 common/image.c Ramdisk unit name specified
3394 -124 common/image.c Can't get ramdisk subimage node offset
3395 125 common/image.c Got ramdisk subimage node offset
3396 -125 common/image.c Ramdisk subimage hash verification failed
3397 126 common/image.c Ramdisk subimage hash verification OK
3398 -126 common/image.c Ramdisk subimage for unsupported architecture
3399 127 common/image.c Architecture check OK
3400 -127 common/image.c Can't get ramdisk subimage data/size
3401 128 common/image.c Got ramdisk subimage data/size
3402 129 common/image.c Can't get ramdisk load address
3403 -129 common/image.c Got ramdisk load address
3405 -130 common/cmd_doc.c Incorrect FIT image format
3406 131 common/cmd_doc.c FIT image format OK
3408 -140 common/cmd_ide.c Incorrect FIT image format
3409 141 common/cmd_ide.c FIT image format OK
3411 -150 common/cmd_nand.c Incorrect FIT image format
3412 151 common/cmd_nand.c FIT image format OK
3414 - legacy image format:
3415 CONFIG_IMAGE_FORMAT_LEGACY
3416 enables the legacy image format support in U-Boot.
3419 enabled if CONFIG_FIT_SIGNATURE is not defined.
3421 CONFIG_DISABLE_IMAGE_LEGACY
3422 disable the legacy image format
3424 This define is introduced, as the legacy image format is
3425 enabled per default for backward compatibility.
3427 - FIT image support:
3429 Enable support for the FIT uImage format.
3431 CONFIG_FIT_BEST_MATCH
3432 When no configuration is explicitly selected, default to the
3433 one whose fdt's compatibility field best matches that of
3434 U-Boot itself. A match is considered "best" if it matches the
3435 most specific compatibility entry of U-Boot's fdt's root node.
3436 The order of entries in the configuration's fdt is ignored.
3438 CONFIG_FIT_SIGNATURE
3439 This option enables signature verification of FIT uImages,
3440 using a hash signed and verified using RSA. If
3441 CONFIG_SHA_PROG_HW_ACCEL is defined, i.e support for progressive
3442 hashing is available using hardware, RSA library will use it.
3443 See doc/uImage.FIT/signature.txt for more details.
3445 WARNING: When relying on signed FIT images with required
3446 signature check the legacy image format is default
3447 disabled. If a board need legacy image format support
3448 enable this through CONFIG_IMAGE_FORMAT_LEGACY
3450 CONFIG_FIT_DISABLE_SHA256
3451 Supporting SHA256 hashes has quite an impact on binary size.
3452 For constrained systems sha256 hash support can be disabled
3455 - Standalone program support:
3456 CONFIG_STANDALONE_LOAD_ADDR
3458 This option defines a board specific value for the
3459 address where standalone program gets loaded, thus
3460 overwriting the architecture dependent default
3463 - Frame Buffer Address:
3466 Define CONFIG_FB_ADDR if you want to use specific
3467 address for frame buffer. This is typically the case
3468 when using a graphics controller has separate video
3469 memory. U-Boot will then place the frame buffer at
3470 the given address instead of dynamically reserving it
3471 in system RAM by calling lcd_setmem(), which grabs
3472 the memory for the frame buffer depending on the
3473 configured panel size.
3475 Please see board_init_f function.
3477 - Automatic software updates via TFTP server
3479 CONFIG_UPDATE_TFTP_CNT_MAX
3480 CONFIG_UPDATE_TFTP_MSEC_MAX
3482 These options enable and control the auto-update feature;
3483 for a more detailed description refer to doc/README.update.
3485 - MTD Support (mtdparts command, UBI support)
3488 Adds the MTD device infrastructure from the Linux kernel.
3489 Needed for mtdparts command support.
3491 CONFIG_MTD_PARTITIONS
3493 Adds the MTD partitioning infrastructure from the Linux
3494 kernel. Needed for UBI support.
3496 CONFIG_MTD_NAND_VERIFY_WRITE
3497 verify if the written data is correct reread.
3502 Adds commands for interacting with MTD partitions formatted
3503 with the UBI flash translation layer
3505 Requires also defining CONFIG_RBTREE
3507 CONFIG_UBI_SILENCE_MSG
3509 Make the verbose messages from UBI stop printing. This leaves
3510 warnings and errors enabled.
3513 CONFIG_MTD_UBI_WL_THRESHOLD
3514 This parameter defines the maximum difference between the highest
3515 erase counter value and the lowest erase counter value of eraseblocks
3516 of UBI devices. When this threshold is exceeded, UBI starts performing
3517 wear leveling by means of moving data from eraseblock with low erase
3518 counter to eraseblocks with high erase counter.
3520 The default value should be OK for SLC NAND flashes, NOR flashes and
3521 other flashes which have eraseblock life-cycle 100000 or more.
3522 However, in case of MLC NAND flashes which typically have eraseblock
3523 life-cycle less than 10000, the threshold should be lessened (e.g.,
3524 to 128 or 256, although it does not have to be power of 2).
3528 CONFIG_MTD_UBI_BEB_LIMIT
3529 This option specifies the maximum bad physical eraseblocks UBI
3530 expects on the MTD device (per 1024 eraseblocks). If the
3531 underlying flash does not admit of bad eraseblocks (e.g. NOR
3532 flash), this value is ignored.
3534 NAND datasheets often specify the minimum and maximum NVM
3535 (Number of Valid Blocks) for the flashes' endurance lifetime.
3536 The maximum expected bad eraseblocks per 1024 eraseblocks
3537 then can be calculated as "1024 * (1 - MinNVB / MaxNVB)",
3538 which gives 20 for most NANDs (MaxNVB is basically the total
3539 count of eraseblocks on the chip).
3541 To put it differently, if this value is 20, UBI will try to
3542 reserve about 1.9% of physical eraseblocks for bad blocks
3543 handling. And that will be 1.9% of eraseblocks on the entire
3544 NAND chip, not just the MTD partition UBI attaches. This means
3545 that if you have, say, a NAND flash chip admits maximum 40 bad
3546 eraseblocks, and it is split on two MTD partitions of the same
3547 size, UBI will reserve 40 eraseblocks when attaching a
3552 CONFIG_MTD_UBI_FASTMAP
3553 Fastmap is a mechanism which allows attaching an UBI device
3554 in nearly constant time. Instead of scanning the whole MTD device it
3555 only has to locate a checkpoint (called fastmap) on the device.
3556 The on-flash fastmap contains all information needed to attach
3557 the device. Using fastmap makes only sense on large devices where
3558 attaching by scanning takes long. UBI will not automatically install
3559 a fastmap on old images, but you can set the UBI parameter
3560 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT to 1 if you want so. Please note
3561 that fastmap-enabled images are still usable with UBI implementations
3562 without fastmap support. On typical flash devices the whole fastmap
3563 fits into one PEB. UBI will reserve PEBs to hold two fastmaps.
3565 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT
3566 Set this parameter to enable fastmap automatically on images
3573 Adds commands for interacting with UBI volumes formatted as
3574 UBIFS. UBIFS is read-only in u-boot.
3576 Requires UBI support as well as CONFIG_LZO
3578 CONFIG_UBIFS_SILENCE_MSG
3580 Make the verbose messages from UBIFS stop printing. This leaves
3581 warnings and errors enabled.
3585 Enable building of SPL globally.
3588 LDSCRIPT for linking the SPL binary.
3590 CONFIG_SPL_MAX_FOOTPRINT
3591 Maximum size in memory allocated to the SPL, BSS included.
3592 When defined, the linker checks that the actual memory
3593 used by SPL from _start to __bss_end does not exceed it.
3594 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
3595 must not be both defined at the same time.
3598 Maximum size of the SPL image (text, data, rodata, and
3599 linker lists sections), BSS excluded.
3600 When defined, the linker checks that the actual size does
3603 CONFIG_SPL_TEXT_BASE
3604 TEXT_BASE for linking the SPL binary.
3606 CONFIG_SPL_RELOC_TEXT_BASE
3607 Address to relocate to. If unspecified, this is equal to
3608 CONFIG_SPL_TEXT_BASE (i.e. no relocation is done).
3610 CONFIG_SPL_BSS_START_ADDR
3611 Link address for the BSS within the SPL binary.
3613 CONFIG_SPL_BSS_MAX_SIZE
3614 Maximum size in memory allocated to the SPL BSS.
3615 When defined, the linker checks that the actual memory used
3616 by SPL from __bss_start to __bss_end does not exceed it.
3617 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
3618 must not be both defined at the same time.
3621 Adress of the start of the stack SPL will use
3623 CONFIG_SPL_RELOC_STACK
3624 Adress of the start of the stack SPL will use after
3625 relocation. If unspecified, this is equal to
3628 CONFIG_SYS_SPL_MALLOC_START
3629 Starting address of the malloc pool used in SPL.
3631 CONFIG_SYS_SPL_MALLOC_SIZE
3632 The size of the malloc pool used in SPL.
3634 CONFIG_SPL_FRAMEWORK
3635 Enable the SPL framework under common/. This framework
3636 supports MMC, NAND and YMODEM loading of U-Boot and NAND
3637 NAND loading of the Linux Kernel.
3640 Enable booting directly to an OS from SPL.
3641 See also: doc/README.falcon
3643 CONFIG_SPL_DISPLAY_PRINT
3644 For ARM, enable an optional function to print more information
3645 about the running system.
3647 CONFIG_SPL_INIT_MINIMAL
3648 Arch init code should be built for a very small image
3650 CONFIG_SPL_LIBCOMMON_SUPPORT
3651 Support for common/libcommon.o in SPL binary
3653 CONFIG_SPL_LIBDISK_SUPPORT
3654 Support for disk/libdisk.o in SPL binary
3656 CONFIG_SPL_I2C_SUPPORT
3657 Support for drivers/i2c/libi2c.o in SPL binary
3659 CONFIG_SPL_GPIO_SUPPORT
3660 Support for drivers/gpio/libgpio.o in SPL binary
3662 CONFIG_SPL_MMC_SUPPORT
3663 Support for drivers/mmc/libmmc.o in SPL binary
3665 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_SECTOR,
3666 CONFIG_SYS_U_BOOT_MAX_SIZE_SECTORS,
3667 Address and partition on the MMC to load U-Boot from
3668 when the MMC is being used in raw mode.
3670 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_PARTITION
3671 Partition on the MMC to load U-Boot from when the MMC is being
3674 CONFIG_SYS_MMCSD_RAW_MODE_KERNEL_SECTOR
3675 Sector to load kernel uImage from when MMC is being
3676 used in raw mode (for Falcon mode)
3678 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTOR,
3679 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTORS
3680 Sector and number of sectors to load kernel argument
3681 parameters from when MMC is being used in raw mode
3684 CONFIG_SYS_MMCSD_FS_BOOT_PARTITION
3685 Partition on the MMC to load U-Boot from when the MMC is being
3688 CONFIG_SPL_FAT_SUPPORT
3689 Support for fs/fat/libfat.o in SPL binary
3691 CONFIG_SPL_EXT_SUPPORT
3692 Support for EXT filesystem in SPL binary
3694 CONFIG_SPL_FS_LOAD_PAYLOAD_NAME
3695 Filename to read to load U-Boot when reading from filesystem
3697 CONFIG_SPL_FS_LOAD_KERNEL_NAME
3698 Filename to read to load kernel uImage when reading
3699 from filesystem (for Falcon mode)
3701 CONFIG_SPL_FS_LOAD_ARGS_NAME
3702 Filename to read to load kernel argument parameters
3703 when reading from filesystem (for Falcon mode)
3705 CONFIG_SPL_MPC83XX_WAIT_FOR_NAND
3706 Set this for NAND SPL on PPC mpc83xx targets, so that
3707 start.S waits for the rest of the SPL to load before
3708 continuing (the hardware starts execution after just
3709 loading the first page rather than the full 4K).
3711 CONFIG_SPL_SKIP_RELOCATE
3712 Avoid SPL relocation
3714 CONFIG_SPL_NAND_BASE
3715 Include nand_base.c in the SPL. Requires
3716 CONFIG_SPL_NAND_DRIVERS.
3718 CONFIG_SPL_NAND_DRIVERS
3719 SPL uses normal NAND drivers, not minimal drivers.
3722 Include standard software ECC in the SPL
3724 CONFIG_SPL_NAND_SIMPLE
3725 Support for NAND boot using simple NAND drivers that
3726 expose the cmd_ctrl() interface.
3728 CONFIG_SPL_MTD_SUPPORT
3729 Support for the MTD subsystem within SPL. Useful for
3730 environment on NAND support within SPL.
3732 CONFIG_SPL_NAND_RAW_ONLY
3733 Support to boot only raw u-boot.bin images. Use this only
3734 if you need to save space.
3736 CONFIG_SPL_MPC8XXX_INIT_DDR_SUPPORT
3737 Set for the SPL on PPC mpc8xxx targets, support for
3738 drivers/ddr/fsl/libddr.o in SPL binary.
3740 CONFIG_SPL_COMMON_INIT_DDR
3741 Set for common ddr init with serial presence detect in
3744 CONFIG_SYS_NAND_5_ADDR_CYCLE, CONFIG_SYS_NAND_PAGE_COUNT,
3745 CONFIG_SYS_NAND_PAGE_SIZE, CONFIG_SYS_NAND_OOBSIZE,
3746 CONFIG_SYS_NAND_BLOCK_SIZE, CONFIG_SYS_NAND_BAD_BLOCK_POS,
3747 CONFIG_SYS_NAND_ECCPOS, CONFIG_SYS_NAND_ECCSIZE,
3748 CONFIG_SYS_NAND_ECCBYTES
3749 Defines the size and behavior of the NAND that SPL uses
3752 CONFIG_SPL_NAND_BOOT
3753 Add support NAND boot
3755 CONFIG_SYS_NAND_U_BOOT_OFFS
3756 Location in NAND to read U-Boot from
3758 CONFIG_SYS_NAND_U_BOOT_DST
3759 Location in memory to load U-Boot to
3761 CONFIG_SYS_NAND_U_BOOT_SIZE
3762 Size of image to load
3764 CONFIG_SYS_NAND_U_BOOT_START
3765 Entry point in loaded image to jump to
3767 CONFIG_SYS_NAND_HW_ECC_OOBFIRST
3768 Define this if you need to first read the OOB and then the
3769 data. This is used, for example, on davinci platforms.
3771 CONFIG_SPL_OMAP3_ID_NAND
3772 Support for an OMAP3-specific set of functions to return the
3773 ID and MFR of the first attached NAND chip, if present.
3775 CONFIG_SPL_SERIAL_SUPPORT
3776 Support for drivers/serial/libserial.o in SPL binary
3778 CONFIG_SPL_SPI_FLASH_SUPPORT
3779 Support for drivers/mtd/spi/libspi_flash.o in SPL binary
3781 CONFIG_SPL_SPI_SUPPORT
3782 Support for drivers/spi/libspi.o in SPL binary
3784 CONFIG_SPL_RAM_DEVICE
3785 Support for running image already present in ram, in SPL binary
3787 CONFIG_SPL_LIBGENERIC_SUPPORT
3788 Support for lib/libgeneric.o in SPL binary
3790 CONFIG_SPL_ENV_SUPPORT
3791 Support for the environment operating in SPL binary
3793 CONFIG_SPL_NET_SUPPORT
3794 Support for the net/libnet.o in SPL binary.
3795 It conflicts with SPL env from storage medium specified by
3796 CONFIG_ENV_IS_xxx but CONFIG_ENV_IS_NOWHERE
3799 Image offset to which the SPL should be padded before appending
3800 the SPL payload. By default, this is defined as
3801 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3802 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3803 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3806 Final target image containing SPL and payload. Some SPLs
3807 use an arch-specific makefile fragment instead, for
3808 example if more than one image needs to be produced.
3810 CONFIG_FIT_SPL_PRINT
3811 Printing information about a FIT image adds quite a bit of
3812 code to SPL. So this is normally disabled in SPL. Use this
3813 option to re-enable it. This will affect the output of the
3814 bootm command when booting a FIT image.
3818 Enable building of TPL globally.
3821 Image offset to which the TPL should be padded before appending
3822 the TPL payload. By default, this is defined as
3823 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3824 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3825 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3830 [so far only for SMDK2400 boards]
3832 - Modem support enable:
3833 CONFIG_MODEM_SUPPORT
3835 - RTS/CTS Flow control enable:
3838 - Modem debug support:
3839 CONFIG_MODEM_SUPPORT_DEBUG
3841 Enables debugging stuff (char screen[1024], dbg())
3842 for modem support. Useful only with BDI2000.
3844 - Interrupt support (PPC):
3846 There are common interrupt_init() and timer_interrupt()
3847 for all PPC archs. interrupt_init() calls interrupt_init_cpu()
3848 for CPU specific initialization. interrupt_init_cpu()
3849 should set decrementer_count to appropriate value. If
3850 CPU resets decrementer automatically after interrupt
3851 (ppc4xx) it should set decrementer_count to zero.
3852 timer_interrupt() calls timer_interrupt_cpu() for CPU
3853 specific handling. If board has watchdog / status_led
3854 / other_activity_monitor it works automatically from
3855 general timer_interrupt().
3859 In the target system modem support is enabled when a
3860 specific key (key combination) is pressed during
3861 power-on. Otherwise U-Boot will boot normally
3862 (autoboot). The key_pressed() function is called from
3863 board_init(). Currently key_pressed() is a dummy
3864 function, returning 1 and thus enabling modem
3867 If there are no modem init strings in the
3868 environment, U-Boot proceed to autoboot; the
3869 previous output (banner, info printfs) will be
3872 See also: doc/README.Modem
3874 Board initialization settings:
3875 ------------------------------
3877 During Initialization u-boot calls a number of board specific functions
3878 to allow the preparation of board specific prerequisites, e.g. pin setup
3879 before drivers are initialized. To enable these callbacks the
3880 following configuration macros have to be defined. Currently this is
3881 architecture specific, so please check arch/your_architecture/lib/board.c
3882 typically in board_init_f() and board_init_r().
3884 - CONFIG_BOARD_EARLY_INIT_F: Call board_early_init_f()
3885 - CONFIG_BOARD_EARLY_INIT_R: Call board_early_init_r()
3886 - CONFIG_BOARD_LATE_INIT: Call board_late_init()
3887 - CONFIG_BOARD_POSTCLK_INIT: Call board_postclk_init()
3889 Configuration Settings:
3890 -----------------------
3892 - CONFIG_SYS_SUPPORT_64BIT_DATA: Defined automatically if compiled as 64-bit.
3893 Optionally it can be defined to support 64-bit memory commands.
3895 - CONFIG_SYS_LONGHELP: Defined when you want long help messages included;
3896 undefine this when you're short of memory.
3898 - CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default
3899 width of the commands listed in the 'help' command output.
3901 - CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to
3902 prompt for user input.
3904 - CONFIG_SYS_CBSIZE: Buffer size for input from the Console
3906 - CONFIG_SYS_PBSIZE: Buffer size for Console output
3908 - CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands
3910 - CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to
3911 the application (usually a Linux kernel) when it is
3914 - CONFIG_SYS_BAUDRATE_TABLE:
3915 List of legal baudrate settings for this board.
3917 - CONFIG_SYS_CONSOLE_INFO_QUIET
3918 Suppress display of console information at boot.
3920 - CONFIG_SYS_CONSOLE_IS_IN_ENV
3921 If the board specific function
3922 extern int overwrite_console (void);
3923 returns 1, the stdin, stderr and stdout are switched to the
3924 serial port, else the settings in the environment are used.
3926 - CONFIG_SYS_CONSOLE_OVERWRITE_ROUTINE
3927 Enable the call to overwrite_console().
3929 - CONFIG_SYS_CONSOLE_ENV_OVERWRITE
3930 Enable overwrite of previous console environment settings.
3932 - CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END:
3933 Begin and End addresses of the area used by the
3936 - CONFIG_SYS_ALT_MEMTEST:
3937 Enable an alternate, more extensive memory test.
3939 - CONFIG_SYS_MEMTEST_SCRATCH:
3940 Scratch address used by the alternate memory test
3941 You only need to set this if address zero isn't writeable
3943 - CONFIG_SYS_MEM_TOP_HIDE (PPC only):
3944 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header,
3945 this specified memory area will get subtracted from the top
3946 (end) of RAM and won't get "touched" at all by U-Boot. By
3947 fixing up gd->ram_size the Linux kernel should gets passed
3948 the now "corrected" memory size and won't touch it either.
3949 This should work for arch/ppc and arch/powerpc. Only Linux
3950 board ports in arch/powerpc with bootwrapper support that
3951 recalculate the memory size from the SDRAM controller setup
3952 will have to get fixed in Linux additionally.
3954 This option can be used as a workaround for the 440EPx/GRx
3955 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't
3958 WARNING: Please make sure that this value is a multiple of
3959 the Linux page size (normally 4k). If this is not the case,
3960 then the end address of the Linux memory will be located at a
3961 non page size aligned address and this could cause major
3964 - CONFIG_SYS_LOADS_BAUD_CHANGE:
3965 Enable temporary baudrate change while serial download
3967 - CONFIG_SYS_SDRAM_BASE:
3968 Physical start address of SDRAM. _Must_ be 0 here.
3970 - CONFIG_SYS_MBIO_BASE:
3971 Physical start address of Motherboard I/O (if using a
3974 - CONFIG_SYS_FLASH_BASE:
3975 Physical start address of Flash memory.
3977 - CONFIG_SYS_MONITOR_BASE:
3978 Physical start address of boot monitor code (set by
3979 make config files to be same as the text base address
3980 (CONFIG_SYS_TEXT_BASE) used when linking) - same as
3981 CONFIG_SYS_FLASH_BASE when booting from flash.
3983 - CONFIG_SYS_MONITOR_LEN:
3984 Size of memory reserved for monitor code, used to
3985 determine _at_compile_time_ (!) if the environment is
3986 embedded within the U-Boot image, or in a separate
3989 - CONFIG_SYS_MALLOC_LEN:
3990 Size of DRAM reserved for malloc() use.
3992 - CONFIG_SYS_MALLOC_F_LEN
3993 Size of the malloc() pool for use before relocation. If
3994 this is defined, then a very simple malloc() implementation
3995 will become available before relocation. The address is just
3996 below the global data, and the stack is moved down to make
3999 This feature allocates regions with increasing addresses
4000 within the region. calloc() is supported, but realloc()
4001 is not available. free() is supported but does nothing.
4002 The memory will be freed (or in fact just forgotten) when
4003 U-Boot relocates itself.
4005 Pre-relocation malloc() is only supported on ARM and sandbox
4006 at present but is fairly easy to enable for other archs.
4008 - CONFIG_SYS_MALLOC_SIMPLE
4009 Provides a simple and small malloc() and calloc() for those
4010 boards which do not use the full malloc in SPL (which is
4011 enabled with CONFIG_SYS_SPL_MALLOC_START).
4013 - CONFIG_SYS_NONCACHED_MEMORY:
4014 Size of non-cached memory area. This area of memory will be
4015 typically located right below the malloc() area and mapped
4016 uncached in the MMU. This is useful for drivers that would
4017 otherwise require a lot of explicit cache maintenance. For
4018 some drivers it's also impossible to properly maintain the
4019 cache. For example if the regions that need to be flushed
4020 are not a multiple of the cache-line size, *and* padding
4021 cannot be allocated between the regions to align them (i.e.
4022 if the HW requires a contiguous array of regions, and the
4023 size of each region is not cache-aligned), then a flush of
4024 one region may result in overwriting data that hardware has
4025 written to another region in the same cache-line. This can
4026 happen for example in network drivers where descriptors for
4027 buffers are typically smaller than the CPU cache-line (e.g.
4028 16 bytes vs. 32 or 64 bytes).
4030 Non-cached memory is only supported on 32-bit ARM at present.
4032 - CONFIG_SYS_BOOTM_LEN:
4033 Normally compressed uImages are limited to an
4034 uncompressed size of 8 MBytes. If this is not enough,
4035 you can define CONFIG_SYS_BOOTM_LEN in your board config file
4036 to adjust this setting to your needs.
4038 - CONFIG_SYS_BOOTMAPSZ:
4039 Maximum size of memory mapped by the startup code of
4040 the Linux kernel; all data that must be processed by
4041 the Linux kernel (bd_info, boot arguments, FDT blob if
4042 used) must be put below this limit, unless "bootm_low"
4043 environment variable is defined and non-zero. In such case
4044 all data for the Linux kernel must be between "bootm_low"
4045 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ. The environment
4046 variable "bootm_mapsize" will override the value of
4047 CONFIG_SYS_BOOTMAPSZ. If CONFIG_SYS_BOOTMAPSZ is undefined,
4048 then the value in "bootm_size" will be used instead.
4050 - CONFIG_SYS_BOOT_RAMDISK_HIGH:
4051 Enable initrd_high functionality. If defined then the
4052 initrd_high feature is enabled and the bootm ramdisk subcommand
4055 - CONFIG_SYS_BOOT_GET_CMDLINE:
4056 Enables allocating and saving kernel cmdline in space between
4057 "bootm_low" and "bootm_low" + BOOTMAPSZ.
4059 - CONFIG_SYS_BOOT_GET_KBD:
4060 Enables allocating and saving a kernel copy of the bd_info in
4061 space between "bootm_low" and "bootm_low" + BOOTMAPSZ.
4063 - CONFIG_SYS_MAX_FLASH_BANKS:
4064 Max number of Flash memory banks
4066 - CONFIG_SYS_MAX_FLASH_SECT:
4067 Max number of sectors on a Flash chip
4069 - CONFIG_SYS_FLASH_ERASE_TOUT:
4070 Timeout for Flash erase operations (in ms)
4072 - CONFIG_SYS_FLASH_WRITE_TOUT:
4073 Timeout for Flash write operations (in ms)
4075 - CONFIG_SYS_FLASH_LOCK_TOUT
4076 Timeout for Flash set sector lock bit operation (in ms)
4078 - CONFIG_SYS_FLASH_UNLOCK_TOUT
4079 Timeout for Flash clear lock bits operation (in ms)
4081 - CONFIG_SYS_FLASH_PROTECTION
4082 If defined, hardware flash sectors protection is used
4083 instead of U-Boot software protection.
4085 - CONFIG_SYS_DIRECT_FLASH_TFTP:
4087 Enable TFTP transfers directly to flash memory;
4088 without this option such a download has to be
4089 performed in two steps: (1) download to RAM, and (2)
4090 copy from RAM to flash.
4092 The two-step approach is usually more reliable, since
4093 you can check if the download worked before you erase
4094 the flash, but in some situations (when system RAM is
4095 too limited to allow for a temporary copy of the
4096 downloaded image) this option may be very useful.
4098 - CONFIG_SYS_FLASH_CFI:
4099 Define if the flash driver uses extra elements in the
4100 common flash structure for storing flash geometry.
4102 - CONFIG_FLASH_CFI_DRIVER
4103 This option also enables the building of the cfi_flash driver
4104 in the drivers directory
4106 - CONFIG_FLASH_CFI_MTD
4107 This option enables the building of the cfi_mtd driver
4108 in the drivers directory. The driver exports CFI flash
4111 - CONFIG_SYS_FLASH_USE_BUFFER_WRITE
4112 Use buffered writes to flash.
4114 - CONFIG_FLASH_SPANSION_S29WS_N
4115 s29ws-n MirrorBit flash has non-standard addresses for buffered
4118 - CONFIG_SYS_FLASH_QUIET_TEST
4119 If this option is defined, the common CFI flash doesn't
4120 print it's warning upon not recognized FLASH banks. This
4121 is useful, if some of the configured banks are only
4122 optionally available.
4124 - CONFIG_FLASH_SHOW_PROGRESS
4125 If defined (must be an integer), print out countdown
4126 digits and dots. Recommended value: 45 (9..1) for 80
4127 column displays, 15 (3..1) for 40 column displays.
4129 - CONFIG_FLASH_VERIFY
4130 If defined, the content of the flash (destination) is compared
4131 against the source after the write operation. An error message
4132 will be printed when the contents are not identical.
4133 Please note that this option is useless in nearly all cases,
4134 since such flash programming errors usually are detected earlier
4135 while unprotecting/erasing/programming. Please only enable
4136 this option if you really know what you are doing.
4138 - CONFIG_SYS_RX_ETH_BUFFER:
4139 Defines the number of Ethernet receive buffers. On some
4140 Ethernet controllers it is recommended to set this value
4141 to 8 or even higher (EEPRO100 or 405 EMAC), since all
4142 buffers can be full shortly after enabling the interface
4143 on high Ethernet traffic.
4144 Defaults to 4 if not defined.
4146 - CONFIG_ENV_MAX_ENTRIES
4148 Maximum number of entries in the hash table that is used
4149 internally to store the environment settings. The default
4150 setting is supposed to be generous and should work in most
4151 cases. This setting can be used to tune behaviour; see
4152 lib/hashtable.c for details.
4154 - CONFIG_ENV_FLAGS_LIST_DEFAULT
4155 - CONFIG_ENV_FLAGS_LIST_STATIC
4156 Enable validation of the values given to environment variables when
4157 calling env set. Variables can be restricted to only decimal,
4158 hexadecimal, or boolean. If CONFIG_CMD_NET is also defined,
4159 the variables can also be restricted to IP address or MAC address.
4161 The format of the list is:
4162 type_attribute = [s|d|x|b|i|m]
4163 access_attribute = [a|r|o|c]
4164 attributes = type_attribute[access_attribute]
4165 entry = variable_name[:attributes]
4168 The type attributes are:
4169 s - String (default)
4172 b - Boolean ([1yYtT|0nNfF])
4176 The access attributes are:
4182 - CONFIG_ENV_FLAGS_LIST_DEFAULT
4183 Define this to a list (string) to define the ".flags"
4184 environment variable in the default or embedded environment.
4186 - CONFIG_ENV_FLAGS_LIST_STATIC
4187 Define this to a list (string) to define validation that
4188 should be done if an entry is not found in the ".flags"
4189 environment variable. To override a setting in the static
4190 list, simply add an entry for the same variable name to the
4193 - CONFIG_ENV_ACCESS_IGNORE_FORCE
4194 If defined, don't allow the -f switch to env set override variable
4197 - CONFIG_SYS_GENERIC_BOARD
4198 This selects the architecture-generic board system instead of the
4199 architecture-specific board files. It is intended to move boards
4200 to this new framework over time. Defining this will disable the
4201 arch/foo/lib/board.c file and use common/board_f.c and
4202 common/board_r.c instead. To use this option your architecture
4203 must support it (i.e. must define __HAVE_ARCH_GENERIC_BOARD in
4204 its config.mk file). If you find problems enabling this option on
4205 your board please report the problem and send patches!
4207 - CONFIG_OMAP_PLATFORM_RESET_TIME_MAX_USEC (OMAP only)
4208 This is set by OMAP boards for the max time that reset should
4209 be asserted. See doc/README.omap-reset-time for details on how
4210 the value can be calculated on a given board.
4213 If stdint.h is available with your toolchain you can define this
4214 option to enable it. You can provide option 'USE_STDINT=1' when
4215 building U-Boot to enable this.
4217 The following definitions that deal with the placement and management
4218 of environment data (variable area); in general, we support the
4219 following configurations:
4221 - CONFIG_BUILD_ENVCRC:
4223 Builds up envcrc with the target environment so that external utils
4224 may easily extract it and embed it in final U-Boot images.
4226 - CONFIG_ENV_IS_IN_FLASH:
4228 Define this if the environment is in flash memory.
4230 a) The environment occupies one whole flash sector, which is
4231 "embedded" in the text segment with the U-Boot code. This
4232 happens usually with "bottom boot sector" or "top boot
4233 sector" type flash chips, which have several smaller
4234 sectors at the start or the end. For instance, such a
4235 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In
4236 such a case you would place the environment in one of the
4237 4 kB sectors - with U-Boot code before and after it. With
4238 "top boot sector" type flash chips, you would put the
4239 environment in one of the last sectors, leaving a gap
4240 between U-Boot and the environment.
4242 - CONFIG_ENV_OFFSET:
4244 Offset of environment data (variable area) to the
4245 beginning of flash memory; for instance, with bottom boot
4246 type flash chips the second sector can be used: the offset
4247 for this sector is given here.
4249 CONFIG_ENV_OFFSET is used relative to CONFIG_SYS_FLASH_BASE.
4253 This is just another way to specify the start address of
4254 the flash sector containing the environment (instead of
4257 - CONFIG_ENV_SECT_SIZE:
4259 Size of the sector containing the environment.
4262 b) Sometimes flash chips have few, equal sized, BIG sectors.
4263 In such a case you don't want to spend a whole sector for
4268 If you use this in combination with CONFIG_ENV_IS_IN_FLASH
4269 and CONFIG_ENV_SECT_SIZE, you can specify to use only a part
4270 of this flash sector for the environment. This saves
4271 memory for the RAM copy of the environment.
4273 It may also save flash memory if you decide to use this
4274 when your environment is "embedded" within U-Boot code,
4275 since then the remainder of the flash sector could be used
4276 for U-Boot code. It should be pointed out that this is
4277 STRONGLY DISCOURAGED from a robustness point of view:
4278 updating the environment in flash makes it always
4279 necessary to erase the WHOLE sector. If something goes
4280 wrong before the contents has been restored from a copy in
4281 RAM, your target system will be dead.
4283 - CONFIG_ENV_ADDR_REDUND
4284 CONFIG_ENV_SIZE_REDUND
4286 These settings describe a second storage area used to hold
4287 a redundant copy of the environment data, so that there is
4288 a valid backup copy in case there is a power failure during
4289 a "saveenv" operation.
4291 BE CAREFUL! Any changes to the flash layout, and some changes to the
4292 source code will make it necessary to adapt <board>/u-boot.lds*
4296 - CONFIG_ENV_IS_IN_NVRAM:
4298 Define this if you have some non-volatile memory device
4299 (NVRAM, battery buffered SRAM) which you want to use for the
4305 These two #defines are used to determine the memory area you
4306 want to use for environment. It is assumed that this memory
4307 can just be read and written to, without any special
4310 BE CAREFUL! The first access to the environment happens quite early
4311 in U-Boot initialization (when we try to get the setting of for the
4312 console baudrate). You *MUST* have mapped your NVRAM area then, or
4315 Please note that even with NVRAM we still use a copy of the
4316 environment in RAM: we could work on NVRAM directly, but we want to
4317 keep settings there always unmodified except somebody uses "saveenv"
4318 to save the current settings.
4321 - CONFIG_ENV_IS_IN_EEPROM:
4323 Use this if you have an EEPROM or similar serial access
4324 device and a driver for it.
4326 - CONFIG_ENV_OFFSET:
4329 These two #defines specify the offset and size of the
4330 environment area within the total memory of your EEPROM.
4332 - CONFIG_SYS_I2C_EEPROM_ADDR:
4333 If defined, specified the chip address of the EEPROM device.
4334 The default address is zero.
4336 - CONFIG_SYS_I2C_EEPROM_BUS:
4337 If defined, specified the i2c bus of the EEPROM device.
4339 - CONFIG_SYS_EEPROM_PAGE_WRITE_BITS:
4340 If defined, the number of bits used to address bytes in a
4341 single page in the EEPROM device. A 64 byte page, for example
4342 would require six bits.
4344 - CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS:
4345 If defined, the number of milliseconds to delay between
4346 page writes. The default is zero milliseconds.
4348 - CONFIG_SYS_I2C_EEPROM_ADDR_LEN:
4349 The length in bytes of the EEPROM memory array address. Note
4350 that this is NOT the chip address length!
4352 - CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW:
4353 EEPROM chips that implement "address overflow" are ones
4354 like Catalyst 24WC04/08/16 which has 9/10/11 bits of
4355 address and the extra bits end up in the "chip address" bit
4356 slots. This makes a 24WC08 (1Kbyte) chip look like four 256
4359 Note that we consider the length of the address field to
4360 still be one byte because the extra address bits are hidden
4361 in the chip address.
4363 - CONFIG_SYS_EEPROM_SIZE:
4364 The size in bytes of the EEPROM device.
4366 - CONFIG_ENV_EEPROM_IS_ON_I2C
4367 define this, if you have I2C and SPI activated, and your
4368 EEPROM, which holds the environment, is on the I2C bus.
4370 - CONFIG_I2C_ENV_EEPROM_BUS
4371 if you have an Environment on an EEPROM reached over
4372 I2C muxes, you can define here, how to reach this
4373 EEPROM. For example:
4375 #define CONFIG_I2C_ENV_EEPROM_BUS 1
4377 EEPROM which holds the environment, is reached over
4378 a pca9547 i2c mux with address 0x70, channel 3.
4380 - CONFIG_ENV_IS_IN_DATAFLASH:
4382 Define this if you have a DataFlash memory device which you
4383 want to use for the environment.
4385 - CONFIG_ENV_OFFSET:
4389 These three #defines specify the offset and size of the
4390 environment area within the total memory of your DataFlash placed
4391 at the specified address.
4393 - CONFIG_ENV_IS_IN_SPI_FLASH:
4395 Define this if you have a SPI Flash memory device which you
4396 want to use for the environment.
4398 - CONFIG_ENV_OFFSET:
4401 These two #defines specify the offset and size of the
4402 environment area within the SPI Flash. CONFIG_ENV_OFFSET must be
4403 aligned to an erase sector boundary.
4405 - CONFIG_ENV_SECT_SIZE:
4407 Define the SPI flash's sector size.
4409 - CONFIG_ENV_OFFSET_REDUND (optional):
4411 This setting describes a second storage area of CONFIG_ENV_SIZE
4412 size used to hold a redundant copy of the environment data, so
4413 that there is a valid backup copy in case there is a power failure
4414 during a "saveenv" operation. CONFIG_ENV_OFFSET_RENDUND must be
4415 aligned to an erase sector boundary.
4417 - CONFIG_ENV_SPI_BUS (optional):
4418 - CONFIG_ENV_SPI_CS (optional):
4420 Define the SPI bus and chip select. If not defined they will be 0.
4422 - CONFIG_ENV_SPI_MAX_HZ (optional):
4424 Define the SPI max work clock. If not defined then use 1MHz.
4426 - CONFIG_ENV_SPI_MODE (optional):
4428 Define the SPI work mode. If not defined then use SPI_MODE_3.
4430 - CONFIG_ENV_IS_IN_REMOTE:
4432 Define this if you have a remote memory space which you
4433 want to use for the local device's environment.
4438 These two #defines specify the address and size of the
4439 environment area within the remote memory space. The
4440 local device can get the environment from remote memory
4441 space by SRIO or PCIE links.
4443 BE CAREFUL! For some special cases, the local device can not use
4444 "saveenv" command. For example, the local device will get the
4445 environment stored in a remote NOR flash by SRIO or PCIE link,
4446 but it can not erase, write this NOR flash by SRIO or PCIE interface.
4448 - CONFIG_ENV_IS_IN_NAND:
4450 Define this if you have a NAND device which you want to use
4451 for the environment.
4453 - CONFIG_ENV_OFFSET:
4456 These two #defines specify the offset and size of the environment
4457 area within the first NAND device. CONFIG_ENV_OFFSET must be
4458 aligned to an erase block boundary.
4460 - CONFIG_ENV_OFFSET_REDUND (optional):
4462 This setting describes a second storage area of CONFIG_ENV_SIZE
4463 size used to hold a redundant copy of the environment data, so
4464 that there is a valid backup copy in case there is a power failure
4465 during a "saveenv" operation. CONFIG_ENV_OFFSET_RENDUND must be
4466 aligned to an erase block boundary.
4468 - CONFIG_ENV_RANGE (optional):
4470 Specifies the length of the region in which the environment
4471 can be written. This should be a multiple of the NAND device's
4472 block size. Specifying a range with more erase blocks than
4473 are needed to hold CONFIG_ENV_SIZE allows bad blocks within
4474 the range to be avoided.
4476 - CONFIG_ENV_OFFSET_OOB (optional):
4478 Enables support for dynamically retrieving the offset of the
4479 environment from block zero's out-of-band data. The
4480 "nand env.oob" command can be used to record this offset.
4481 Currently, CONFIG_ENV_OFFSET_REDUND is not supported when
4482 using CONFIG_ENV_OFFSET_OOB.
4484 - CONFIG_NAND_ENV_DST
4486 Defines address in RAM to which the nand_spl code should copy the
4487 environment. If redundant environment is used, it will be copied to
4488 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE.
4490 - CONFIG_ENV_IS_IN_UBI:
4492 Define this if you have an UBI volume that you want to use for the
4493 environment. This has the benefit of wear-leveling the environment
4494 accesses, which is important on NAND.
4496 - CONFIG_ENV_UBI_PART:
4498 Define this to a string that is the mtd partition containing the UBI.
4500 - CONFIG_ENV_UBI_VOLUME:
4502 Define this to the name of the volume that you want to store the
4505 - CONFIG_ENV_UBI_VOLUME_REDUND:
4507 Define this to the name of another volume to store a second copy of
4508 the environment in. This will enable redundant environments in UBI.
4509 It is assumed that both volumes are in the same MTD partition.
4511 - CONFIG_UBI_SILENCE_MSG
4512 - CONFIG_UBIFS_SILENCE_MSG
4514 You will probably want to define these to avoid a really noisy system
4515 when storing the env in UBI.
4517 - CONFIG_ENV_IS_IN_FAT:
4518 Define this if you want to use the FAT file system for the environment.
4520 - FAT_ENV_INTERFACE:
4522 Define this to a string that is the name of the block device.
4524 - FAT_ENV_DEV_AND_PART:
4526 Define this to a string to specify the partition of the device. It can
4529 "D:P", "D:0", "D", "D:" or "D:auto" (D, P are integers. And P >= 1)
4530 - "D:P": device D partition P. Error occurs if device D has no
4533 - "D" or "D:": device D partition 1 if device D has partition
4534 table, or the whole device D if has no partition
4536 - "D:auto": first partition in device D with bootable flag set.
4537 If none, first valid partition in device D. If no
4538 partition table then means device D.
4542 It's a string of the FAT file name. This file use to store the
4546 This should be defined. Otherwise it cannot save the environment file.
4548 - CONFIG_ENV_IS_IN_MMC:
4550 Define this if you have an MMC device which you want to use for the
4553 - CONFIG_SYS_MMC_ENV_DEV:
4555 Specifies which MMC device the environment is stored in.
4557 - CONFIG_SYS_MMC_ENV_PART (optional):
4559 Specifies which MMC partition the environment is stored in. If not
4560 set, defaults to partition 0, the user area. Common values might be
4561 1 (first MMC boot partition), 2 (second MMC boot partition).
4563 - CONFIG_ENV_OFFSET:
4566 These two #defines specify the offset and size of the environment
4567 area within the specified MMC device.
4569 If offset is positive (the usual case), it is treated as relative to
4570 the start of the MMC partition. If offset is negative, it is treated
4571 as relative to the end of the MMC partition. This can be useful if
4572 your board may be fitted with different MMC devices, which have
4573 different sizes for the MMC partitions, and you always want the
4574 environment placed at the very end of the partition, to leave the
4575 maximum possible space before it, to store other data.
4577 These two values are in units of bytes, but must be aligned to an
4578 MMC sector boundary.
4580 - CONFIG_ENV_OFFSET_REDUND (optional):
4582 Specifies a second storage area, of CONFIG_ENV_SIZE size, used to
4583 hold a redundant copy of the environment data. This provides a
4584 valid backup copy in case the other copy is corrupted, e.g. due
4585 to a power failure during a "saveenv" operation.
4587 This value may also be positive or negative; this is handled in the
4588 same way as CONFIG_ENV_OFFSET.
4590 This value is also in units of bytes, but must also be aligned to
4591 an MMC sector boundary.
4593 - CONFIG_ENV_SIZE_REDUND (optional):
4595 This value need not be set, even when CONFIG_ENV_OFFSET_REDUND is
4596 set. If this value is set, it must be set to the same value as
4599 - CONFIG_SYS_SPI_INIT_OFFSET
4601 Defines offset to the initial SPI buffer area in DPRAM. The
4602 area is used at an early stage (ROM part) if the environment
4603 is configured to reside in the SPI EEPROM: We need a 520 byte
4604 scratch DPRAM area. It is used between the two initialization
4605 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems
4606 to be a good choice since it makes it far enough from the
4607 start of the data area as well as from the stack pointer.
4609 Please note that the environment is read-only until the monitor
4610 has been relocated to RAM and a RAM copy of the environment has been
4611 created; also, when using EEPROM you will have to use getenv_f()
4612 until then to read environment variables.
4614 The environment is protected by a CRC32 checksum. Before the monitor
4615 is relocated into RAM, as a result of a bad CRC you will be working
4616 with the compiled-in default environment - *silently*!!! [This is
4617 necessary, because the first environment variable we need is the
4618 "baudrate" setting for the console - if we have a bad CRC, we don't
4619 have any device yet where we could complain.]
4621 Note: once the monitor has been relocated, then it will complain if
4622 the default environment is used; a new CRC is computed as soon as you
4623 use the "saveenv" command to store a valid environment.
4625 - CONFIG_SYS_FAULT_ECHO_LINK_DOWN:
4626 Echo the inverted Ethernet link state to the fault LED.
4628 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR
4629 also needs to be defined.
4631 - CONFIG_SYS_FAULT_MII_ADDR:
4632 MII address of the PHY to check for the Ethernet link state.
4634 - CONFIG_NS16550_MIN_FUNCTIONS:
4635 Define this if you desire to only have use of the NS16550_init
4636 and NS16550_putc functions for the serial driver located at
4637 drivers/serial/ns16550.c. This option is useful for saving
4638 space for already greatly restricted images, including but not
4639 limited to NAND_SPL configurations.
4641 - CONFIG_DISPLAY_BOARDINFO
4642 Display information about the board that U-Boot is running on
4643 when U-Boot starts up. The board function checkboard() is called
4646 - CONFIG_DISPLAY_BOARDINFO_LATE
4647 Similar to the previous option, but display this information
4648 later, once stdio is running and output goes to the LCD, if
4651 - CONFIG_BOARD_SIZE_LIMIT:
4652 Maximum size of the U-Boot image. When defined, the
4653 build system checks that the actual size does not
4656 Low Level (hardware related) configuration options:
4657 ---------------------------------------------------
4659 - CONFIG_SYS_CACHELINE_SIZE:
4660 Cache Line Size of the CPU.
4662 - CONFIG_SYS_DEFAULT_IMMR:
4663 Default address of the IMMR after system reset.
4665 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU,
4666 and RPXsuper) to be able to adjust the position of
4667 the IMMR register after a reset.
4669 - CONFIG_SYS_CCSRBAR_DEFAULT:
4670 Default (power-on reset) physical address of CCSR on Freescale
4673 - CONFIG_SYS_CCSRBAR:
4674 Virtual address of CCSR. On a 32-bit build, this is typically
4675 the same value as CONFIG_SYS_CCSRBAR_DEFAULT.
4677 CONFIG_SYS_DEFAULT_IMMR must also be set to this value,
4678 for cross-platform code that uses that macro instead.
4680 - CONFIG_SYS_CCSRBAR_PHYS:
4681 Physical address of CCSR. CCSR can be relocated to a new
4682 physical address, if desired. In this case, this macro should
4683 be set to that address. Otherwise, it should be set to the
4684 same value as CONFIG_SYS_CCSRBAR_DEFAULT. For example, CCSR
4685 is typically relocated on 36-bit builds. It is recommended
4686 that this macro be defined via the _HIGH and _LOW macros:
4688 #define CONFIG_SYS_CCSRBAR_PHYS ((CONFIG_SYS_CCSRBAR_PHYS_HIGH
4689 * 1ull) << 32 | CONFIG_SYS_CCSRBAR_PHYS_LOW)
4691 - CONFIG_SYS_CCSRBAR_PHYS_HIGH:
4692 Bits 33-36 of CONFIG_SYS_CCSRBAR_PHYS. This value is typically
4693 either 0 (32-bit build) or 0xF (36-bit build). This macro is
4694 used in assembly code, so it must not contain typecasts or
4695 integer size suffixes (e.g. "ULL").
4697 - CONFIG_SYS_CCSRBAR_PHYS_LOW:
4698 Lower 32-bits of CONFIG_SYS_CCSRBAR_PHYS. This macro is
4699 used in assembly code, so it must not contain typecasts or
4700 integer size suffixes (e.g. "ULL").
4702 - CONFIG_SYS_CCSR_DO_NOT_RELOCATE:
4703 If this macro is defined, then CONFIG_SYS_CCSRBAR_PHYS will be
4704 forced to a value that ensures that CCSR is not relocated.
4706 - Floppy Disk Support:
4707 CONFIG_SYS_FDC_DRIVE_NUMBER
4709 the default drive number (default value 0)
4711 CONFIG_SYS_ISA_IO_STRIDE
4713 defines the spacing between FDC chipset registers
4716 CONFIG_SYS_ISA_IO_OFFSET
4718 defines the offset of register from address. It
4719 depends on which part of the data bus is connected to
4720 the FDC chipset. (default value 0)
4722 If CONFIG_SYS_ISA_IO_STRIDE CONFIG_SYS_ISA_IO_OFFSET and
4723 CONFIG_SYS_FDC_DRIVE_NUMBER are undefined, they take their
4726 if CONFIG_SYS_FDC_HW_INIT is defined, then the function
4727 fdc_hw_init() is called at the beginning of the FDC
4728 setup. fdc_hw_init() must be provided by the board
4729 source code. It is used to make hardware-dependent
4733 Most IDE controllers were designed to be connected with PCI
4734 interface. Only few of them were designed for AHB interface.
4735 When software is doing ATA command and data transfer to
4736 IDE devices through IDE-AHB controller, some additional
4737 registers accessing to these kind of IDE-AHB controller
4740 - CONFIG_SYS_IMMR: Physical address of the Internal Memory.
4741 DO NOT CHANGE unless you know exactly what you're
4742 doing! (11-4) [MPC8xx/82xx systems only]
4744 - CONFIG_SYS_INIT_RAM_ADDR:
4746 Start address of memory area that can be used for
4747 initial data and stack; please note that this must be
4748 writable memory that is working WITHOUT special
4749 initialization, i. e. you CANNOT use normal RAM which
4750 will become available only after programming the
4751 memory controller and running certain initialization
4754 U-Boot uses the following memory types:
4755 - MPC8xx and MPC8260: IMMR (internal memory of the CPU)
4756 - MPC824X: data cache
4757 - PPC4xx: data cache
4759 - CONFIG_SYS_GBL_DATA_OFFSET:
4761 Offset of the initial data structure in the memory
4762 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually
4763 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial
4764 data is located at the end of the available space
4765 (sometimes written as (CONFIG_SYS_INIT_RAM_SIZE -
4766 CONFIG_SYS_INIT_DATA_SIZE), and the initial stack is just
4767 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR +
4768 CONFIG_SYS_GBL_DATA_OFFSET) downward.
4771 On the MPC824X (or other systems that use the data
4772 cache for initial memory) the address chosen for
4773 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must
4774 point to an otherwise UNUSED address space between
4775 the top of RAM and the start of the PCI space.
4777 - CONFIG_SYS_SIUMCR: SIU Module Configuration (11-6)
4779 - CONFIG_SYS_SYPCR: System Protection Control (11-9)
4781 - CONFIG_SYS_TBSCR: Time Base Status and Control (11-26)
4783 - CONFIG_SYS_PISCR: Periodic Interrupt Status and Control (11-31)
4785 - CONFIG_SYS_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30)
4787 - CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27)
4789 - CONFIG_SYS_OR_TIMING_SDRAM:
4792 - CONFIG_SYS_MAMR_PTA:
4793 periodic timer for refresh
4795 - CONFIG_SYS_DER: Debug Event Register (37-47)
4797 - FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM,
4798 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP,
4799 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM,
4800 CONFIG_SYS_BR1_PRELIM:
4801 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
4803 - SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
4804 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM,
4805 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM:
4806 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
4808 - CONFIG_SYS_MAMR_PTA, CONFIG_SYS_MPTPR_2BK_4K, CONFIG_SYS_MPTPR_1BK_4K, CONFIG_SYS_MPTPR_2BK_8K,
4809 CONFIG_SYS_MPTPR_1BK_8K, CONFIG_SYS_MAMR_8COL, CONFIG_SYS_MAMR_9COL:
4810 Machine Mode Register and Memory Periodic Timer
4811 Prescaler definitions (SDRAM timing)
4813 - CONFIG_SYS_I2C_UCODE_PATCH, CONFIG_SYS_I2C_DPMEM_OFFSET [0x1FC0]:
4814 enable I2C microcode relocation patch (MPC8xx);
4815 define relocation offset in DPRAM [DSP2]
4817 - CONFIG_SYS_SMC_UCODE_PATCH, CONFIG_SYS_SMC_DPMEM_OFFSET [0x1FC0]:
4818 enable SMC microcode relocation patch (MPC8xx);
4819 define relocation offset in DPRAM [SMC1]
4821 - CONFIG_SYS_SPI_UCODE_PATCH, CONFIG_SYS_SPI_DPMEM_OFFSET [0x1FC0]:
4822 enable SPI microcode relocation patch (MPC8xx);
4823 define relocation offset in DPRAM [SCC4]
4825 - CONFIG_SYS_USE_OSCCLK:
4826 Use OSCM clock mode on MBX8xx board. Be careful,
4827 wrong setting might damage your board. Read
4828 doc/README.MBX before setting this variable!
4830 - CONFIG_SYS_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only)
4831 Offset of the bootmode word in DPRAM used by post
4832 (Power On Self Tests). This definition overrides
4833 #define'd default value in commproc.h resp.
4836 - CONFIG_SYS_PCI_SLV_MEM_LOCAL, CONFIG_SYS_PCI_SLV_MEM_BUS, CONFIG_SYS_PICMR0_MASK_ATTRIB,
4837 CONFIG_SYS_PCI_MSTR0_LOCAL, CONFIG_SYS_PCIMSK0_MASK, CONFIG_SYS_PCI_MSTR1_LOCAL,
4838 CONFIG_SYS_PCIMSK1_MASK, CONFIG_SYS_PCI_MSTR_MEM_LOCAL, CONFIG_SYS_PCI_MSTR_MEM_BUS,
4839 CONFIG_SYS_CPU_PCI_MEM_START, CONFIG_SYS_PCI_MSTR_MEM_SIZE, CONFIG_SYS_POCMR0_MASK_ATTRIB,
4840 CONFIG_SYS_PCI_MSTR_MEMIO_LOCAL, CONFIG_SYS_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START,
4841 CONFIG_SYS_PCI_MSTR_MEMIO_SIZE, CONFIG_SYS_POCMR1_MASK_ATTRIB, CONFIG_SYS_PCI_MSTR_IO_LOCAL,
4842 CONFIG_SYS_PCI_MSTR_IO_BUS, CONFIG_SYS_CPU_PCI_IO_START, CONFIG_SYS_PCI_MSTR_IO_SIZE,
4843 CONFIG_SYS_POCMR2_MASK_ATTRIB: (MPC826x only)
4844 Overrides the default PCI memory map in arch/powerpc/cpu/mpc8260/pci.c if set.
4846 - CONFIG_PCI_DISABLE_PCIE:
4847 Disable PCI-Express on systems where it is supported but not
4850 - CONFIG_PCI_ENUM_ONLY
4851 Only scan through and get the devices on the buses.
4852 Don't do any setup work, presumably because someone or
4853 something has already done it, and we don't need to do it
4854 a second time. Useful for platforms that are pre-booted
4855 by coreboot or similar.
4857 - CONFIG_PCI_INDIRECT_BRIDGE:
4858 Enable support for indirect PCI bridges.
4861 Chip has SRIO or not
4864 Board has SRIO 1 port available
4867 Board has SRIO 2 port available
4869 - CONFIG_SRIO_PCIE_BOOT_MASTER
4870 Board can support master function for Boot from SRIO and PCIE
4872 - CONFIG_SYS_SRIOn_MEM_VIRT:
4873 Virtual Address of SRIO port 'n' memory region
4875 - CONFIG_SYS_SRIOn_MEM_PHYS:
4876 Physical Address of SRIO port 'n' memory region
4878 - CONFIG_SYS_SRIOn_MEM_SIZE:
4879 Size of SRIO port 'n' memory region
4881 - CONFIG_SYS_NAND_BUSWIDTH_16BIT
4882 Defined to tell the NAND controller that the NAND chip is using
4884 Not all NAND drivers use this symbol.
4885 Example of drivers that use it:
4886 - drivers/mtd/nand/ndfc.c
4887 - drivers/mtd/nand/mxc_nand.c
4889 - CONFIG_SYS_NDFC_EBC0_CFG
4890 Sets the EBC0_CFG register for the NDFC. If not defined
4891 a default value will be used.
4894 Get DDR timing information from an I2C EEPROM. Common
4895 with pluggable memory modules such as SODIMMs
4898 I2C address of the SPD EEPROM
4900 - CONFIG_SYS_SPD_BUS_NUM
4901 If SPD EEPROM is on an I2C bus other than the first
4902 one, specify here. Note that the value must resolve
4903 to something your driver can deal with.
4905 - CONFIG_SYS_DDR_RAW_TIMING
4906 Get DDR timing information from other than SPD. Common with
4907 soldered DDR chips onboard without SPD. DDR raw timing
4908 parameters are extracted from datasheet and hard-coded into
4909 header files or board specific files.
4911 - CONFIG_FSL_DDR_INTERACTIVE
4912 Enable interactive DDR debugging. See doc/README.fsl-ddr.
4914 - CONFIG_FSL_DDR_SYNC_REFRESH
4915 Enable sync of refresh for multiple controllers.
4917 - CONFIG_SYS_83XX_DDR_USES_CS0
4918 Only for 83xx systems. If specified, then DDR should
4919 be configured using CS0 and CS1 instead of CS2 and CS3.
4921 - CONFIG_ETHER_ON_FEC[12]
4922 Define to enable FEC[12] on a 8xx series processor.
4924 - CONFIG_FEC[12]_PHY
4925 Define to the hardcoded PHY address which corresponds
4926 to the given FEC; i. e.
4927 #define CONFIG_FEC1_PHY 4
4928 means that the PHY with address 4 is connected to FEC1
4930 When set to -1, means to probe for first available.
4932 - CONFIG_FEC[12]_PHY_NORXERR
4933 The PHY does not have a RXERR line (RMII only).
4934 (so program the FEC to ignore it).
4937 Enable RMII mode for all FECs.
4938 Note that this is a global option, we can't
4939 have one FEC in standard MII mode and another in RMII mode.
4941 - CONFIG_CRC32_VERIFY
4942 Add a verify option to the crc32 command.
4945 => crc32 -v <address> <count> <crc32>
4947 Where address/count indicate a memory area
4948 and crc32 is the correct crc32 which the
4952 Add the "loopw" memory command. This only takes effect if
4953 the memory commands are activated globally (CONFIG_CMD_MEM).
4956 Add the "mdc" and "mwc" memory commands. These are cyclic
4961 This command will print 4 bytes (10,11,12,13) each 500 ms.
4963 => mwc.l 100 12345678 10
4964 This command will write 12345678 to address 100 all 10 ms.
4966 This only takes effect if the memory commands are activated
4967 globally (CONFIG_CMD_MEM).
4969 - CONFIG_SKIP_LOWLEVEL_INIT
4970 [ARM, NDS32, MIPS only] If this variable is defined, then certain
4971 low level initializations (like setting up the memory
4972 controller) are omitted and/or U-Boot does not
4973 relocate itself into RAM.
4975 Normally this variable MUST NOT be defined. The only
4976 exception is when U-Boot is loaded (to RAM) by some
4977 other boot loader or by a debugger which performs
4978 these initializations itself.
4981 Modifies the behaviour of start.S when compiling a loader
4982 that is executed before the actual U-Boot. E.g. when
4983 compiling a NAND SPL.
4986 Modifies the behaviour of start.S when compiling a loader
4987 that is executed after the SPL and before the actual U-Boot.
4988 It is loaded by the SPL.
4990 - CONFIG_SYS_MPC85XX_NO_RESETVEC
4991 Only for 85xx systems. If this variable is specified, the section
4992 .resetvec is not kept and the section .bootpg is placed in the
4993 previous 4k of the .text section.
4995 - CONFIG_ARCH_MAP_SYSMEM
4996 Generally U-Boot (and in particular the md command) uses
4997 effective address. It is therefore not necessary to regard
4998 U-Boot address as virtual addresses that need to be translated
4999 to physical addresses. However, sandbox requires this, since
5000 it maintains its own little RAM buffer which contains all
5001 addressable memory. This option causes some memory accesses
5002 to be mapped through map_sysmem() / unmap_sysmem().
5004 - CONFIG_USE_ARCH_MEMCPY
5005 CONFIG_USE_ARCH_MEMSET
5006 If these options are used a optimized version of memcpy/memset will
5007 be used if available. These functions may be faster under some
5008 conditions but may increase the binary size.
5010 - CONFIG_X86_RESET_VECTOR
5011 If defined, the x86 reset vector code is included. This is not
5012 needed when U-Boot is running from Coreboot.
5015 Defines the MPU clock speed (in MHz).
5017 NOTE : currently only supported on AM335x platforms.
5019 - CONFIG_SPL_AM33XX_ENABLE_RTC32K_OSC:
5020 Enables the RTC32K OSC on AM33xx based plattforms
5022 - CONFIG_SYS_NAND_NO_SUBPAGE_WRITE
5023 Option to disable subpage write in NAND driver
5024 driver that uses this:
5025 drivers/mtd/nand/davinci_nand.c
5027 Freescale QE/FMAN Firmware Support:
5028 -----------------------------------
5030 The Freescale QUICCEngine (QE) and Frame Manager (FMAN) both support the
5031 loading of "firmware", which is encoded in the QE firmware binary format.
5032 This firmware often needs to be loaded during U-Boot booting, so macros
5033 are used to identify the storage device (NOR flash, SPI, etc) and the address
5036 - CONFIG_SYS_FMAN_FW_ADDR
5037 The address in the storage device where the FMAN microcode is located. The
5038 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
5041 - CONFIG_SYS_QE_FW_ADDR
5042 The address in the storage device where the QE microcode is located. The
5043 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
5046 - CONFIG_SYS_QE_FMAN_FW_LENGTH
5047 The maximum possible size of the firmware. The firmware binary format
5048 has a field that specifies the actual size of the firmware, but it
5049 might not be possible to read any part of the firmware unless some
5050 local storage is allocated to hold the entire firmware first.
5052 - CONFIG_SYS_QE_FMAN_FW_IN_NOR
5053 Specifies that QE/FMAN firmware is located in NOR flash, mapped as
5054 normal addressable memory via the LBC. CONFIG_SYS_FMAN_FW_ADDR is the
5055 virtual address in NOR flash.
5057 - CONFIG_SYS_QE_FMAN_FW_IN_NAND
5058 Specifies that QE/FMAN firmware is located in NAND flash.
5059 CONFIG_SYS_FMAN_FW_ADDR is the offset within NAND flash.
5061 - CONFIG_SYS_QE_FMAN_FW_IN_MMC
5062 Specifies that QE/FMAN firmware is located on the primary SD/MMC
5063 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
5065 - CONFIG_SYS_QE_FMAN_FW_IN_SPIFLASH
5066 Specifies that QE/FMAN firmware is located on the primary SPI
5067 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
5069 - CONFIG_SYS_QE_FMAN_FW_IN_REMOTE
5070 Specifies that QE/FMAN firmware is located in the remote (master)
5071 memory space. CONFIG_SYS_FMAN_FW_ADDR is a virtual address which
5072 can be mapped from slave TLB->slave LAW->slave SRIO or PCIE outbound
5073 window->master inbound window->master LAW->the ucode address in
5074 master's memory space.
5076 Freescale Layerscape Management Complex Firmware Support:
5077 ---------------------------------------------------------
5078 The Freescale Layerscape Management Complex (MC) supports the loading of
5080 This firmware often needs to be loaded during U-Boot booting, so macros
5081 are used to identify the storage device (NOR flash, SPI, etc) and the address
5084 - CONFIG_FSL_MC_ENET
5085 Enable the MC driver for Layerscape SoCs.
5087 - CONFIG_SYS_LS_MC_FW_ADDR
5088 The address in the storage device where the firmware is located. The
5089 meaning of this address depends on which CONFIG_SYS_LS_MC_FW_IN_xxx macro
5092 - CONFIG_SYS_LS_MC_FW_LENGTH
5093 The maximum possible size of the firmware. The firmware binary format
5094 has a field that specifies the actual size of the firmware, but it
5095 might not be possible to read any part of the firmware unless some
5096 local storage is allocated to hold the entire firmware first.
5098 - CONFIG_SYS_LS_MC_FW_IN_NOR
5099 Specifies that MC firmware is located in NOR flash, mapped as
5100 normal addressable memory via the LBC. CONFIG_SYS_LS_MC_FW_ADDR is the
5101 virtual address in NOR flash.
5103 Building the Software:
5104 ======================
5106 Building U-Boot has been tested in several native build environments
5107 and in many different cross environments. Of course we cannot support
5108 all possibly existing versions of cross development tools in all
5109 (potentially obsolete) versions. In case of tool chain problems we
5110 recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK)
5111 which is extensively used to build and test U-Boot.
5113 If you are not using a native environment, it is assumed that you
5114 have GNU cross compiling tools available in your path. In this case,
5115 you must set the environment variable CROSS_COMPILE in your shell.
5116 Note that no changes to the Makefile or any other source files are
5117 necessary. For example using the ELDK on a 4xx CPU, please enter:
5119 $ CROSS_COMPILE=ppc_4xx-
5120 $ export CROSS_COMPILE
5122 Note: If you wish to generate Windows versions of the utilities in
5123 the tools directory you can use the MinGW toolchain
5124 (http://www.mingw.org). Set your HOST tools to the MinGW
5125 toolchain and execute 'make tools'. For example:
5127 $ make HOSTCC=i586-mingw32msvc-gcc HOSTSTRIP=i586-mingw32msvc-strip tools
5129 Binaries such as tools/mkimage.exe will be created which can
5130 be executed on computers running Windows.
5132 U-Boot is intended to be simple to build. After installing the
5133 sources you must configure U-Boot for one specific board type. This
5138 where "NAME_defconfig" is the name of one of the existing configu-
5139 rations; see boards.cfg for supported names.
5141 Note: for some board special configuration names may exist; check if
5142 additional information is available from the board vendor; for
5143 instance, the TQM823L systems are available without (standard)
5144 or with LCD support. You can select such additional "features"
5145 when choosing the configuration, i. e.
5147 make TQM823L_defconfig
5148 - will configure for a plain TQM823L, i. e. no LCD support
5150 make TQM823L_LCD_defconfig
5151 - will configure for a TQM823L with U-Boot console on LCD
5156 Finally, type "make all", and you should get some working U-Boot
5157 images ready for download to / installation on your system:
5159 - "u-boot.bin" is a raw binary image
5160 - "u-boot" is an image in ELF binary format
5161 - "u-boot.srec" is in Motorola S-Record format
5163 By default the build is performed locally and the objects are saved
5164 in the source directory. One of the two methods can be used to change
5165 this behavior and build U-Boot to some external directory:
5167 1. Add O= to the make command line invocations:
5169 make O=/tmp/build distclean
5170 make O=/tmp/build NAME_defconfig
5171 make O=/tmp/build all
5173 2. Set environment variable KBUILD_OUTPUT to point to the desired location:
5175 export KBUILD_OUTPUT=/tmp/build
5180 Note that the command line "O=" setting overrides the KBUILD_OUTPUT environment
5184 Please be aware that the Makefiles assume you are using GNU make, so
5185 for instance on NetBSD you might need to use "gmake" instead of
5189 If the system board that you have is not listed, then you will need
5190 to port U-Boot to your hardware platform. To do this, follow these
5193 1. Add a new configuration option for your board to the toplevel
5194 "boards.cfg" file, using the existing entries as examples.
5195 Follow the instructions there to keep the boards in order.
5196 2. Create a new directory to hold your board specific code. Add any
5197 files you need. In your board directory, you will need at least
5198 the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds".
5199 3. Create a new configuration file "include/configs/<board>.h" for
5201 3. If you're porting U-Boot to a new CPU, then also create a new
5202 directory to hold your CPU specific code. Add any files you need.
5203 4. Run "make <board>_defconfig" with your new name.
5204 5. Type "make", and you should get a working "u-boot.srec" file
5205 to be installed on your target system.
5206 6. Debug and solve any problems that might arise.
5207 [Of course, this last step is much harder than it sounds.]
5210 Testing of U-Boot Modifications, Ports to New Hardware, etc.:
5211 ==============================================================
5213 If you have modified U-Boot sources (for instance added a new board
5214 or support for new devices, a new CPU, etc.) you are expected to
5215 provide feedback to the other developers. The feedback normally takes
5216 the form of a "patch", i. e. a context diff against a certain (latest
5217 official or latest in the git repository) version of U-Boot sources.
5219 But before you submit such a patch, please verify that your modifi-
5220 cation did not break existing code. At least make sure that *ALL* of
5221 the supported boards compile WITHOUT ANY compiler warnings. To do so,
5222 just run the "MAKEALL" script, which will configure and build U-Boot
5223 for ALL supported system. Be warned, this will take a while. You can
5224 select which (cross) compiler to use by passing a `CROSS_COMPILE'
5225 environment variable to the script, i. e. to use the ELDK cross tools
5228 CROSS_COMPILE=ppc_8xx- MAKEALL
5230 or to build on a native PowerPC system you can type
5232 CROSS_COMPILE=' ' MAKEALL
5234 When using the MAKEALL script, the default behaviour is to build
5235 U-Boot in the source directory. This location can be changed by
5236 setting the BUILD_DIR environment variable. Also, for each target
5237 built, the MAKEALL script saves two log files (<target>.ERR and
5238 <target>.MAKEALL) in the <source dir>/LOG directory. This default
5239 location can be changed by setting the MAKEALL_LOGDIR environment
5240 variable. For example:
5242 export BUILD_DIR=/tmp/build
5243 export MAKEALL_LOGDIR=/tmp/log
5244 CROSS_COMPILE=ppc_8xx- MAKEALL
5246 With the above settings build objects are saved in the /tmp/build,
5247 log files are saved in the /tmp/log and the source tree remains clean
5248 during the whole build process.
5251 See also "U-Boot Porting Guide" below.
5254 Monitor Commands - Overview:
5255 ============================
5257 go - start application at address 'addr'
5258 run - run commands in an environment variable
5259 bootm - boot application image from memory
5260 bootp - boot image via network using BootP/TFTP protocol
5261 bootz - boot zImage from memory
5262 tftpboot- boot image via network using TFTP protocol
5263 and env variables "ipaddr" and "serverip"
5264 (and eventually "gatewayip")
5265 tftpput - upload a file via network using TFTP protocol
5266 rarpboot- boot image via network using RARP/TFTP protocol
5267 diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
5268 loads - load S-Record file over serial line
5269 loadb - load binary file over serial line (kermit mode)
5271 mm - memory modify (auto-incrementing)
5272 nm - memory modify (constant address)
5273 mw - memory write (fill)
5275 cmp - memory compare
5276 crc32 - checksum calculation
5277 i2c - I2C sub-system
5278 sspi - SPI utility commands
5279 base - print or set address offset
5280 printenv- print environment variables
5281 setenv - set environment variables
5282 saveenv - save environment variables to persistent storage
5283 protect - enable or disable FLASH write protection
5284 erase - erase FLASH memory
5285 flinfo - print FLASH memory information
5286 nand - NAND memory operations (see doc/README.nand)
5287 bdinfo - print Board Info structure
5288 iminfo - print header information for application image
5289 coninfo - print console devices and informations
5290 ide - IDE sub-system
5291 loop - infinite loop on address range
5292 loopw - infinite write loop on address range
5293 mtest - simple RAM test
5294 icache - enable or disable instruction cache
5295 dcache - enable or disable data cache
5296 reset - Perform RESET of the CPU
5297 echo - echo args to console
5298 version - print monitor version
5299 help - print online help
5300 ? - alias for 'help'
5303 Monitor Commands - Detailed Description:
5304 ========================================
5308 For now: just type "help <command>".
5311 Environment Variables:
5312 ======================
5314 U-Boot supports user configuration using Environment Variables which
5315 can be made persistent by saving to Flash memory.
5317 Environment Variables are set using "setenv", printed using
5318 "printenv", and saved to Flash using "saveenv". Using "setenv"
5319 without a value can be used to delete a variable from the
5320 environment. As long as you don't save the environment you are
5321 working with an in-memory copy. In case the Flash area containing the
5322 environment is erased by accident, a default environment is provided.
5324 Some configuration options can be set using Environment Variables.
5326 List of environment variables (most likely not complete):
5328 baudrate - see CONFIG_BAUDRATE
5330 bootdelay - see CONFIG_BOOTDELAY
5332 bootcmd - see CONFIG_BOOTCOMMAND
5334 bootargs - Boot arguments when booting an RTOS image
5336 bootfile - Name of the image to load with TFTP
5338 bootm_low - Memory range available for image processing in the bootm
5339 command can be restricted. This variable is given as
5340 a hexadecimal number and defines lowest address allowed
5341 for use by the bootm command. See also "bootm_size"
5342 environment variable. Address defined by "bootm_low" is
5343 also the base of the initial memory mapping for the Linux
5344 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ and
5347 bootm_mapsize - Size of the initial memory mapping for the Linux kernel.
5348 This variable is given as a hexadecimal number and it
5349 defines the size of the memory region starting at base
5350 address bootm_low that is accessible by the Linux kernel
5351 during early boot. If unset, CONFIG_SYS_BOOTMAPSZ is used
5352 as the default value if it is defined, and bootm_size is
5355 bootm_size - Memory range available for image processing in the bootm
5356 command can be restricted. This variable is given as
5357 a hexadecimal number and defines the size of the region
5358 allowed for use by the bootm command. See also "bootm_low"
5359 environment variable.
5361 updatefile - Location of the software update file on a TFTP server, used
5362 by the automatic software update feature. Please refer to
5363 documentation in doc/README.update for more details.
5365 autoload - if set to "no" (any string beginning with 'n'),
5366 "bootp" will just load perform a lookup of the
5367 configuration from the BOOTP server, but not try to
5368 load any image using TFTP
5370 autostart - if set to "yes", an image loaded using the "bootp",
5371 "rarpboot", "tftpboot" or "diskboot" commands will
5372 be automatically started (by internally calling
5375 If set to "no", a standalone image passed to the
5376 "bootm" command will be copied to the load address
5377 (and eventually uncompressed), but NOT be started.
5378 This can be used to load and uncompress arbitrary
5381 fdt_high - if set this restricts the maximum address that the
5382 flattened device tree will be copied into upon boot.
5383 For example, if you have a system with 1 GB memory
5384 at physical address 0x10000000, while Linux kernel
5385 only recognizes the first 704 MB as low memory, you
5386 may need to set fdt_high as 0x3C000000 to have the
5387 device tree blob be copied to the maximum address
5388 of the 704 MB low memory, so that Linux kernel can
5389 access it during the boot procedure.
5391 If this is set to the special value 0xFFFFFFFF then
5392 the fdt will not be copied at all on boot. For this
5393 to work it must reside in writable memory, have
5394 sufficient padding on the end of it for u-boot to
5395 add the information it needs into it, and the memory
5396 must be accessible by the kernel.
5398 fdtcontroladdr- if set this is the address of the control flattened
5399 device tree used by U-Boot when CONFIG_OF_CONTROL is
5402 i2cfast - (PPC405GP|PPC405EP only)
5403 if set to 'y' configures Linux I2C driver for fast
5404 mode (400kHZ). This environment variable is used in
5405 initialization code. So, for changes to be effective
5406 it must be saved and board must be reset.
5408 initrd_high - restrict positioning of initrd images:
5409 If this variable is not set, initrd images will be
5410 copied to the highest possible address in RAM; this
5411 is usually what you want since it allows for
5412 maximum initrd size. If for some reason you want to
5413 make sure that the initrd image is loaded below the
5414 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment
5415 variable to a value of "no" or "off" or "0".
5416 Alternatively, you can set it to a maximum upper
5417 address to use (U-Boot will still check that it
5418 does not overwrite the U-Boot stack and data).
5420 For instance, when you have a system with 16 MB
5421 RAM, and want to reserve 4 MB from use by Linux,
5422 you can do this by adding "mem=12M" to the value of
5423 the "bootargs" variable. However, now you must make
5424 sure that the initrd image is placed in the first
5425 12 MB as well - this can be done with
5427 setenv initrd_high 00c00000
5429 If you set initrd_high to 0xFFFFFFFF, this is an
5430 indication to U-Boot that all addresses are legal
5431 for the Linux kernel, including addresses in flash
5432 memory. In this case U-Boot will NOT COPY the
5433 ramdisk at all. This may be useful to reduce the
5434 boot time on your system, but requires that this
5435 feature is supported by your Linux kernel.
5437 ipaddr - IP address; needed for tftpboot command
5439 loadaddr - Default load address for commands like "bootp",
5440 "rarpboot", "tftpboot", "loadb" or "diskboot"
5442 loads_echo - see CONFIG_LOADS_ECHO
5444 serverip - TFTP server IP address; needed for tftpboot command
5446 bootretry - see CONFIG_BOOT_RETRY_TIME
5448 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
5450 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
5452 ethprime - controls which interface is used first.
5454 ethact - controls which interface is currently active.
5455 For example you can do the following
5457 => setenv ethact FEC
5458 => ping 192.168.0.1 # traffic sent on FEC
5459 => setenv ethact SCC
5460 => ping 10.0.0.1 # traffic sent on SCC
5462 ethrotate - When set to "no" U-Boot does not go through all
5463 available network interfaces.
5464 It just stays at the currently selected interface.
5466 netretry - When set to "no" each network operation will
5467 either succeed or fail without retrying.
5468 When set to "once" the network operation will
5469 fail when all the available network interfaces
5470 are tried once without success.
5471 Useful on scripts which control the retry operation
5474 npe_ucode - set load address for the NPE microcode
5476 silent_linux - If set then Linux will be told to boot silently, by
5477 changing the console to be empty. If "yes" it will be
5478 made silent. If "no" it will not be made silent. If
5479 unset, then it will be made silent if the U-Boot console
5482 tftpsrcport - If this is set, the value is used for TFTP's
5485 tftpdstport - If this is set, the value is used for TFTP's UDP
5486 destination port instead of the Well Know Port 69.
5488 tftpblocksize - Block size to use for TFTP transfers; if not set,
5489 we use the TFTP server's default block size
5491 tftptimeout - Retransmission timeout for TFTP packets (in milli-
5492 seconds, minimum value is 1000 = 1 second). Defines
5493 when a packet is considered to be lost so it has to
5494 be retransmitted. The default is 5000 = 5 seconds.
5495 Lowering this value may make downloads succeed
5496 faster in networks with high packet loss rates or
5497 with unreliable TFTP servers.
5499 vlan - When set to a value < 4095 the traffic over
5500 Ethernet is encapsulated/received over 802.1q
5503 The following image location variables contain the location of images
5504 used in booting. The "Image" column gives the role of the image and is
5505 not an environment variable name. The other columns are environment
5506 variable names. "File Name" gives the name of the file on a TFTP
5507 server, "RAM Address" gives the location in RAM the image will be
5508 loaded to, and "Flash Location" gives the image's address in NOR
5509 flash or offset in NAND flash.
5511 *Note* - these variables don't have to be defined for all boards, some
5512 boards currenlty use other variables for these purposes, and some
5513 boards use these variables for other purposes.
5515 Image File Name RAM Address Flash Location
5516 ----- --------- ----------- --------------
5517 u-boot u-boot u-boot_addr_r u-boot_addr
5518 Linux kernel bootfile kernel_addr_r kernel_addr
5519 device tree blob fdtfile fdt_addr_r fdt_addr
5520 ramdisk ramdiskfile ramdisk_addr_r ramdisk_addr
5522 The following environment variables may be used and automatically
5523 updated by the network boot commands ("bootp" and "rarpboot"),
5524 depending the information provided by your boot server:
5526 bootfile - see above
5527 dnsip - IP address of your Domain Name Server
5528 dnsip2 - IP address of your secondary Domain Name Server
5529 gatewayip - IP address of the Gateway (Router) to use
5530 hostname - Target hostname
5532 netmask - Subnet Mask
5533 rootpath - Pathname of the root filesystem on the NFS server
5534 serverip - see above
5537 There are two special Environment Variables:
5539 serial# - contains hardware identification information such
5540 as type string and/or serial number
5541 ethaddr - Ethernet address
5543 These variables can be set only once (usually during manufacturing of
5544 the board). U-Boot refuses to delete or overwrite these variables
5545 once they have been set once.
5548 Further special Environment Variables:
5550 ver - Contains the U-Boot version string as printed
5551 with the "version" command. This variable is
5552 readonly (see CONFIG_VERSION_VARIABLE).
5555 Please note that changes to some configuration parameters may take
5556 only effect after the next boot (yes, that's just like Windoze :-).
5559 Callback functions for environment variables:
5560 ---------------------------------------------
5562 For some environment variables, the behavior of u-boot needs to change
5563 when their values are changed. This functionality allows functions to
5564 be associated with arbitrary variables. On creation, overwrite, or
5565 deletion, the callback will provide the opportunity for some side
5566 effect to happen or for the change to be rejected.
5568 The callbacks are named and associated with a function using the
5569 U_BOOT_ENV_CALLBACK macro in your board or driver code.
5571 These callbacks are associated with variables in one of two ways. The
5572 static list can be added to by defining CONFIG_ENV_CALLBACK_LIST_STATIC
5573 in the board configuration to a string that defines a list of
5574 associations. The list must be in the following format:
5576 entry = variable_name[:callback_name]
5579 If the callback name is not specified, then the callback is deleted.
5580 Spaces are also allowed anywhere in the list.
5582 Callbacks can also be associated by defining the ".callbacks" variable
5583 with the same list format above. Any association in ".callbacks" will
5584 override any association in the static list. You can define
5585 CONFIG_ENV_CALLBACK_LIST_DEFAULT to a list (string) to define the
5586 ".callbacks" environment variable in the default or embedded environment.
5589 Command Line Parsing:
5590 =====================
5592 There are two different command line parsers available with U-Boot:
5593 the old "simple" one, and the much more powerful "hush" shell:
5595 Old, simple command line parser:
5596 --------------------------------
5598 - supports environment variables (through setenv / saveenv commands)
5599 - several commands on one line, separated by ';'
5600 - variable substitution using "... ${name} ..." syntax
5601 - special characters ('$', ';') can be escaped by prefixing with '\',
5603 setenv bootcmd bootm \${address}
5604 - You can also escape text by enclosing in single apostrophes, for example:
5605 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
5610 - similar to Bourne shell, with control structures like
5611 if...then...else...fi, for...do...done; while...do...done,
5612 until...do...done, ...
5613 - supports environment ("global") variables (through setenv / saveenv
5614 commands) and local shell variables (through standard shell syntax
5615 "name=value"); only environment variables can be used with "run"
5621 (1) If a command line (or an environment variable executed by a "run"
5622 command) contains several commands separated by semicolon, and
5623 one of these commands fails, then the remaining commands will be
5626 (2) If you execute several variables with one call to run (i. e.
5627 calling run with a list of variables as arguments), any failing
5628 command will cause "run" to terminate, i. e. the remaining
5629 variables are not executed.
5631 Note for Redundant Ethernet Interfaces:
5632 =======================================
5634 Some boards come with redundant Ethernet interfaces; U-Boot supports
5635 such configurations and is capable of automatic selection of a
5636 "working" interface when needed. MAC assignment works as follows:
5638 Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
5639 MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
5640 "eth1addr" (=>eth1), "eth2addr", ...
5642 If the network interface stores some valid MAC address (for instance
5643 in SROM), this is used as default address if there is NO correspon-
5644 ding setting in the environment; if the corresponding environment
5645 variable is set, this overrides the settings in the card; that means:
5647 o If the SROM has a valid MAC address, and there is no address in the
5648 environment, the SROM's address is used.
5650 o If there is no valid address in the SROM, and a definition in the
5651 environment exists, then the value from the environment variable is
5654 o If both the SROM and the environment contain a MAC address, and
5655 both addresses are the same, this MAC address is used.
5657 o If both the SROM and the environment contain a MAC address, and the
5658 addresses differ, the value from the environment is used and a
5661 o If neither SROM nor the environment contain a MAC address, an error
5664 If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses
5665 will be programmed into hardware as part of the initialization process. This
5666 may be skipped by setting the appropriate 'ethmacskip' environment variable.
5667 The naming convention is as follows:
5668 "ethmacskip" (=>eth0), "eth1macskip" (=>eth1) etc.
5673 U-Boot is capable of booting (and performing other auxiliary operations on)
5674 images in two formats:
5676 New uImage format (FIT)
5677 -----------------------
5679 Flexible and powerful format based on Flattened Image Tree -- FIT (similar
5680 to Flattened Device Tree). It allows the use of images with multiple
5681 components (several kernels, ramdisks, etc.), with contents protected by
5682 SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory.
5688 Old image format is based on binary files which can be basically anything,
5689 preceded by a special header; see the definitions in include/image.h for
5690 details; basically, the header defines the following image properties:
5692 * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
5693 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
5694 LynxOS, pSOS, QNX, RTEMS, INTEGRITY;
5695 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS,
5697 * Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86,
5698 IA64, MIPS, NDS32, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
5699 Currently supported: ARM, AVR32, Intel x86, MIPS, NDS32, Nios II, PowerPC).
5700 * Compression Type (uncompressed, gzip, bzip2)
5706 The header is marked by a special Magic Number, and both the header
5707 and the data portions of the image are secured against corruption by
5714 Although U-Boot should support any OS or standalone application
5715 easily, the main focus has always been on Linux during the design of
5718 U-Boot includes many features that so far have been part of some
5719 special "boot loader" code within the Linux kernel. Also, any
5720 "initrd" images to be used are no longer part of one big Linux image;
5721 instead, kernel and "initrd" are separate images. This implementation
5722 serves several purposes:
5724 - the same features can be used for other OS or standalone
5725 applications (for instance: using compressed images to reduce the
5726 Flash memory footprint)
5728 - it becomes much easier to port new Linux kernel versions because
5729 lots of low-level, hardware dependent stuff are done by U-Boot
5731 - the same Linux kernel image can now be used with different "initrd"
5732 images; of course this also means that different kernel images can
5733 be run with the same "initrd". This makes testing easier (you don't
5734 have to build a new "zImage.initrd" Linux image when you just
5735 change a file in your "initrd"). Also, a field-upgrade of the
5736 software is easier now.
5742 Porting Linux to U-Boot based systems:
5743 ---------------------------------------
5745 U-Boot cannot save you from doing all the necessary modifications to
5746 configure the Linux device drivers for use with your target hardware
5747 (no, we don't intend to provide a full virtual machine interface to
5750 But now you can ignore ALL boot loader code (in arch/powerpc/mbxboot).
5752 Just make sure your machine specific header file (for instance
5753 include/asm-ppc/tqm8xx.h) includes the same definition of the Board
5754 Information structure as we define in include/asm-<arch>/u-boot.h,
5755 and make sure that your definition of IMAP_ADDR uses the same value
5756 as your U-Boot configuration in CONFIG_SYS_IMMR.
5758 Note that U-Boot now has a driver model, a unified model for drivers.
5759 If you are adding a new driver, plumb it into driver model. If there
5760 is no uclass available, you are encouraged to create one. See
5764 Configuring the Linux kernel:
5765 -----------------------------
5767 No specific requirements for U-Boot. Make sure you have some root
5768 device (initial ramdisk, NFS) for your target system.
5771 Building a Linux Image:
5772 -----------------------
5774 With U-Boot, "normal" build targets like "zImage" or "bzImage" are
5775 not used. If you use recent kernel source, a new build target
5776 "uImage" will exist which automatically builds an image usable by
5777 U-Boot. Most older kernels also have support for a "pImage" target,
5778 which was introduced for our predecessor project PPCBoot and uses a
5779 100% compatible format.
5783 make TQM850L_defconfig
5788 The "uImage" build target uses a special tool (in 'tools/mkimage') to
5789 encapsulate a compressed Linux kernel image with header information,
5790 CRC32 checksum etc. for use with U-Boot. This is what we are doing:
5792 * build a standard "vmlinux" kernel image (in ELF binary format):
5794 * convert the kernel into a raw binary image:
5796 ${CROSS_COMPILE}-objcopy -O binary \
5797 -R .note -R .comment \
5798 -S vmlinux linux.bin
5800 * compress the binary image:
5804 * package compressed binary image for U-Boot:
5806 mkimage -A ppc -O linux -T kernel -C gzip \
5807 -a 0 -e 0 -n "Linux Kernel Image" \
5808 -d linux.bin.gz uImage
5811 The "mkimage" tool can also be used to create ramdisk images for use
5812 with U-Boot, either separated from the Linux kernel image, or
5813 combined into one file. "mkimage" encapsulates the images with a 64
5814 byte header containing information about target architecture,
5815 operating system, image type, compression method, entry points, time
5816 stamp, CRC32 checksums, etc.
5818 "mkimage" can be called in two ways: to verify existing images and
5819 print the header information, or to build new images.
5821 In the first form (with "-l" option) mkimage lists the information
5822 contained in the header of an existing U-Boot image; this includes
5823 checksum verification:
5825 tools/mkimage -l image
5826 -l ==> list image header information
5828 The second form (with "-d" option) is used to build a U-Boot image
5829 from a "data file" which is used as image payload:
5831 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
5832 -n name -d data_file image
5833 -A ==> set architecture to 'arch'
5834 -O ==> set operating system to 'os'
5835 -T ==> set image type to 'type'
5836 -C ==> set compression type 'comp'
5837 -a ==> set load address to 'addr' (hex)
5838 -e ==> set entry point to 'ep' (hex)
5839 -n ==> set image name to 'name'
5840 -d ==> use image data from 'datafile'
5842 Right now, all Linux kernels for PowerPC systems use the same load
5843 address (0x00000000), but the entry point address depends on the
5846 - 2.2.x kernels have the entry point at 0x0000000C,
5847 - 2.3.x and later kernels have the entry point at 0x00000000.
5849 So a typical call to build a U-Boot image would read:
5851 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
5852 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
5853 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz \
5854 > examples/uImage.TQM850L
5855 Image Name: 2.4.4 kernel for TQM850L
5856 Created: Wed Jul 19 02:34:59 2000
5857 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5858 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
5859 Load Address: 0x00000000
5860 Entry Point: 0x00000000
5862 To verify the contents of the image (or check for corruption):
5864 -> tools/mkimage -l examples/uImage.TQM850L
5865 Image Name: 2.4.4 kernel for TQM850L
5866 Created: Wed Jul 19 02:34:59 2000
5867 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5868 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
5869 Load Address: 0x00000000
5870 Entry Point: 0x00000000
5872 NOTE: for embedded systems where boot time is critical you can trade
5873 speed for memory and install an UNCOMPRESSED image instead: this
5874 needs more space in Flash, but boots much faster since it does not
5875 need to be uncompressed:
5877 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz
5878 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
5879 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
5880 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux \
5881 > examples/uImage.TQM850L-uncompressed
5882 Image Name: 2.4.4 kernel for TQM850L
5883 Created: Wed Jul 19 02:34:59 2000
5884 Image Type: PowerPC Linux Kernel Image (uncompressed)
5885 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
5886 Load Address: 0x00000000
5887 Entry Point: 0x00000000
5890 Similar you can build U-Boot images from a 'ramdisk.image.gz' file
5891 when your kernel is intended to use an initial ramdisk:
5893 -> tools/mkimage -n 'Simple Ramdisk Image' \
5894 > -A ppc -O linux -T ramdisk -C gzip \
5895 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
5896 Image Name: Simple Ramdisk Image
5897 Created: Wed Jan 12 14:01:50 2000
5898 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5899 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
5900 Load Address: 0x00000000
5901 Entry Point: 0x00000000
5903 The "dumpimage" is a tool to disassemble images built by mkimage. Its "-i"
5904 option performs the converse operation of the mkimage's second form (the "-d"
5905 option). Given an image built by mkimage, the dumpimage extracts a "data file"
5908 tools/dumpimage -i image -T type -p position data_file
5909 -i ==> extract from the 'image' a specific 'data_file'
5910 -T ==> set image type to 'type'
5911 -p ==> 'position' (starting at 0) of the 'data_file' inside the 'image'
5914 Installing a Linux Image:
5915 -------------------------
5917 To downloading a U-Boot image over the serial (console) interface,
5918 you must convert the image to S-Record format:
5920 objcopy -I binary -O srec examples/image examples/image.srec
5922 The 'objcopy' does not understand the information in the U-Boot
5923 image header, so the resulting S-Record file will be relative to
5924 address 0x00000000. To load it to a given address, you need to
5925 specify the target address as 'offset' parameter with the 'loads'
5928 Example: install the image to address 0x40100000 (which on the
5929 TQM8xxL is in the first Flash bank):
5931 => erase 40100000 401FFFFF
5937 ## Ready for S-Record download ...
5938 ~>examples/image.srec
5939 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
5941 15989 15990 15991 15992
5942 [file transfer complete]
5944 ## Start Addr = 0x00000000
5947 You can check the success of the download using the 'iminfo' command;
5948 this includes a checksum verification so you can be sure no data
5949 corruption happened:
5953 ## Checking Image at 40100000 ...
5954 Image Name: 2.2.13 for initrd on TQM850L
5955 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5956 Data Size: 335725 Bytes = 327 kB = 0 MB
5957 Load Address: 00000000
5958 Entry Point: 0000000c
5959 Verifying Checksum ... OK
5965 The "bootm" command is used to boot an application that is stored in
5966 memory (RAM or Flash). In case of a Linux kernel image, the contents
5967 of the "bootargs" environment variable is passed to the kernel as
5968 parameters. You can check and modify this variable using the
5969 "printenv" and "setenv" commands:
5972 => printenv bootargs
5973 bootargs=root=/dev/ram
5975 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5977 => printenv bootargs
5978 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5981 ## Booting Linux kernel at 40020000 ...
5982 Image Name: 2.2.13 for NFS on TQM850L
5983 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5984 Data Size: 381681 Bytes = 372 kB = 0 MB
5985 Load Address: 00000000
5986 Entry Point: 0000000c
5987 Verifying Checksum ... OK
5988 Uncompressing Kernel Image ... OK
5989 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
5990 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5991 time_init: decrementer frequency = 187500000/60
5992 Calibrating delay loop... 49.77 BogoMIPS
5993 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
5996 If you want to boot a Linux kernel with initial RAM disk, you pass
5997 the memory addresses of both the kernel and the initrd image (PPBCOOT
5998 format!) to the "bootm" command:
6000 => imi 40100000 40200000
6002 ## Checking Image at 40100000 ...
6003 Image Name: 2.2.13 for initrd on TQM850L
6004 Image Type: PowerPC Linux Kernel Image (gzip compressed)
6005 Data Size: 335725 Bytes = 327 kB = 0 MB
6006 Load Address: 00000000
6007 Entry Point: 0000000c
6008 Verifying Checksum ... OK
6010 ## Checking Image at 40200000 ...
6011 Image Name: Simple Ramdisk Image
6012 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
6013 Data Size: 566530 Bytes = 553 kB = 0 MB
6014 Load Address: 00000000
6015 Entry Point: 00000000
6016 Verifying Checksum ... OK
6018 => bootm 40100000 40200000
6019 ## Booting Linux kernel at 40100000 ...
6020 Image Name: 2.2.13 for initrd on TQM850L
6021 Image Type: PowerPC Linux Kernel Image (gzip compressed)
6022 Data Size: 335725 Bytes = 327 kB = 0 MB
6023 Load Address: 00000000
6024 Entry Point: 0000000c
6025 Verifying Checksum ... OK
6026 Uncompressing Kernel Image ... OK
6027 ## Loading RAMDisk Image at 40200000 ...
6028 Image Name: Simple Ramdisk Image
6029 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
6030 Data Size: 566530 Bytes = 553 kB = 0 MB
6031 Load Address: 00000000
6032 Entry Point: 00000000
6033 Verifying Checksum ... OK
6034 Loading Ramdisk ... OK
6035 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
6036 Boot arguments: root=/dev/ram
6037 time_init: decrementer frequency = 187500000/60
6038 Calibrating delay loop... 49.77 BogoMIPS
6040 RAMDISK: Compressed image found at block 0
6041 VFS: Mounted root (ext2 filesystem).
6045 Boot Linux and pass a flat device tree:
6048 First, U-Boot must be compiled with the appropriate defines. See the section
6049 titled "Linux Kernel Interface" above for a more in depth explanation. The
6050 following is an example of how to start a kernel and pass an updated
6056 oft=oftrees/mpc8540ads.dtb
6057 => tftp $oftaddr $oft
6058 Speed: 1000, full duplex
6060 TFTP from server 192.168.1.1; our IP address is 192.168.1.101
6061 Filename 'oftrees/mpc8540ads.dtb'.
6062 Load address: 0x300000
6065 Bytes transferred = 4106 (100a hex)
6066 => tftp $loadaddr $bootfile
6067 Speed: 1000, full duplex
6069 TFTP from server 192.168.1.1; our IP address is 192.168.1.2
6071 Load address: 0x200000
6072 Loading:############
6074 Bytes transferred = 1029407 (fb51f hex)
6079 => bootm $loadaddr - $oftaddr
6080 ## Booting image at 00200000 ...
6081 Image Name: Linux-2.6.17-dirty
6082 Image Type: PowerPC Linux Kernel Image (gzip compressed)
6083 Data Size: 1029343 Bytes = 1005.2 kB
6084 Load Address: 00000000
6085 Entry Point: 00000000
6086 Verifying Checksum ... OK
6087 Uncompressing Kernel Image ... OK
6088 Booting using flat device tree at 0x300000
6089 Using MPC85xx ADS machine description
6090 Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb
6094 More About U-Boot Image Types:
6095 ------------------------------
6097 U-Boot supports the following image types:
6099 "Standalone Programs" are directly runnable in the environment
6100 provided by U-Boot; it is expected that (if they behave
6101 well) you can continue to work in U-Boot after return from
6102 the Standalone Program.
6103 "OS Kernel Images" are usually images of some Embedded OS which
6104 will take over control completely. Usually these programs
6105 will install their own set of exception handlers, device
6106 drivers, set up the MMU, etc. - this means, that you cannot
6107 expect to re-enter U-Boot except by resetting the CPU.
6108 "RAMDisk Images" are more or less just data blocks, and their
6109 parameters (address, size) are passed to an OS kernel that is
6111 "Multi-File Images" contain several images, typically an OS
6112 (Linux) kernel image and one or more data images like
6113 RAMDisks. This construct is useful for instance when you want
6114 to boot over the network using BOOTP etc., where the boot
6115 server provides just a single image file, but you want to get
6116 for instance an OS kernel and a RAMDisk image.
6118 "Multi-File Images" start with a list of image sizes, each
6119 image size (in bytes) specified by an "uint32_t" in network
6120 byte order. This list is terminated by an "(uint32_t)0".
6121 Immediately after the terminating 0 follow the images, one by
6122 one, all aligned on "uint32_t" boundaries (size rounded up to
6123 a multiple of 4 bytes).
6125 "Firmware Images" are binary images containing firmware (like
6126 U-Boot or FPGA images) which usually will be programmed to
6129 "Script files" are command sequences that will be executed by
6130 U-Boot's command interpreter; this feature is especially
6131 useful when you configure U-Boot to use a real shell (hush)
6132 as command interpreter.
6134 Booting the Linux zImage:
6135 -------------------------
6137 On some platforms, it's possible to boot Linux zImage. This is done
6138 using the "bootz" command. The syntax of "bootz" command is the same
6139 as the syntax of "bootm" command.
6141 Note, defining the CONFIG_SUPPORT_RAW_INITRD allows user to supply
6142 kernel with raw initrd images. The syntax is slightly different, the
6143 address of the initrd must be augmented by it's size, in the following
6144 format: "<initrd addres>:<initrd size>".
6150 One of the features of U-Boot is that you can dynamically load and
6151 run "standalone" applications, which can use some resources of
6152 U-Boot like console I/O functions or interrupt services.
6154 Two simple examples are included with the sources:
6159 'examples/hello_world.c' contains a small "Hello World" Demo
6160 application; it is automatically compiled when you build U-Boot.
6161 It's configured to run at address 0x00040004, so you can play with it
6165 ## Ready for S-Record download ...
6166 ~>examples/hello_world.srec
6167 1 2 3 4 5 6 7 8 9 10 11 ...
6168 [file transfer complete]
6170 ## Start Addr = 0x00040004
6172 => go 40004 Hello World! This is a test.
6173 ## Starting application at 0x00040004 ...
6184 Hit any key to exit ...
6186 ## Application terminated, rc = 0x0
6188 Another example, which demonstrates how to register a CPM interrupt
6189 handler with the U-Boot code, can be found in 'examples/timer.c'.
6190 Here, a CPM timer is set up to generate an interrupt every second.
6191 The interrupt service routine is trivial, just printing a '.'
6192 character, but this is just a demo program. The application can be
6193 controlled by the following keys:
6195 ? - print current values og the CPM Timer registers
6196 b - enable interrupts and start timer
6197 e - stop timer and disable interrupts
6198 q - quit application
6201 ## Ready for S-Record download ...
6202 ~>examples/timer.srec
6203 1 2 3 4 5 6 7 8 9 10 11 ...
6204 [file transfer complete]
6206 ## Start Addr = 0x00040004
6209 ## Starting application at 0x00040004 ...
6212 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
6215 [q, b, e, ?] Set interval 1000000 us
6218 [q, b, e, ?] ........
6219 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
6222 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
6225 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
6228 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
6230 [q, b, e, ?] ...Stopping timer
6232 [q, b, e, ?] ## Application terminated, rc = 0x0
6238 Over time, many people have reported problems when trying to use the
6239 "minicom" terminal emulation program for serial download. I (wd)
6240 consider minicom to be broken, and recommend not to use it. Under
6241 Unix, I recommend to use C-Kermit for general purpose use (and
6242 especially for kermit binary protocol download ("loadb" command), and
6243 use "cu" for S-Record download ("loads" command). See
6244 http://www.denx.de/wiki/view/DULG/SystemSetup#Section_4.3.
6245 for help with kermit.
6248 Nevertheless, if you absolutely want to use it try adding this
6249 configuration to your "File transfer protocols" section:
6251 Name Program Name U/D FullScr IO-Red. Multi
6252 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
6253 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
6259 Starting at version 0.9.2, U-Boot supports NetBSD both as host
6260 (build U-Boot) and target system (boots NetBSD/mpc8xx).
6262 Building requires a cross environment; it is known to work on
6263 NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
6264 need gmake since the Makefiles are not compatible with BSD make).
6265 Note that the cross-powerpc package does not install include files;
6266 attempting to build U-Boot will fail because <machine/ansi.h> is
6267 missing. This file has to be installed and patched manually:
6269 # cd /usr/pkg/cross/powerpc-netbsd/include
6271 # ln -s powerpc machine
6272 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
6273 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
6275 Native builds *don't* work due to incompatibilities between native
6276 and U-Boot include files.
6278 Booting assumes that (the first part of) the image booted is a
6279 stage-2 loader which in turn loads and then invokes the kernel
6280 proper. Loader sources will eventually appear in the NetBSD source
6281 tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
6282 meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz
6285 Implementation Internals:
6286 =========================
6288 The following is not intended to be a complete description of every
6289 implementation detail. However, it should help to understand the
6290 inner workings of U-Boot and make it easier to port it to custom
6294 Initial Stack, Global Data:
6295 ---------------------------
6297 The implementation of U-Boot is complicated by the fact that U-Boot
6298 starts running out of ROM (flash memory), usually without access to
6299 system RAM (because the memory controller is not initialized yet).
6300 This means that we don't have writable Data or BSS segments, and BSS
6301 is not initialized as zero. To be able to get a C environment working
6302 at all, we have to allocate at least a minimal stack. Implementation
6303 options for this are defined and restricted by the CPU used: Some CPU
6304 models provide on-chip memory (like the IMMR area on MPC8xx and
6305 MPC826x processors), on others (parts of) the data cache can be
6306 locked as (mis-) used as memory, etc.
6308 Chris Hallinan posted a good summary of these issues to the
6309 U-Boot mailing list:
6311 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
6312 From: "Chris Hallinan" <clh@net1plus.com>
6313 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
6316 Correct me if I'm wrong, folks, but the way I understand it
6317 is this: Using DCACHE as initial RAM for Stack, etc, does not
6318 require any physical RAM backing up the cache. The cleverness
6319 is that the cache is being used as a temporary supply of
6320 necessary storage before the SDRAM controller is setup. It's
6321 beyond the scope of this list to explain the details, but you
6322 can see how this works by studying the cache architecture and
6323 operation in the architecture and processor-specific manuals.
6325 OCM is On Chip Memory, which I believe the 405GP has 4K. It
6326 is another option for the system designer to use as an
6327 initial stack/RAM area prior to SDRAM being available. Either
6328 option should work for you. Using CS 4 should be fine if your
6329 board designers haven't used it for something that would
6330 cause you grief during the initial boot! It is frequently not
6333 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere
6334 with your processor/board/system design. The default value
6335 you will find in any recent u-boot distribution in
6336 walnut.h should work for you. I'd set it to a value larger
6337 than your SDRAM module. If you have a 64MB SDRAM module, set
6338 it above 400_0000. Just make sure your board has no resources
6339 that are supposed to respond to that address! That code in
6340 start.S has been around a while and should work as is when
6341 you get the config right.
6346 It is essential to remember this, since it has some impact on the C
6347 code for the initialization procedures:
6349 * Initialized global data (data segment) is read-only. Do not attempt
6352 * Do not use any uninitialized global data (or implicitly initialized
6353 as zero data - BSS segment) at all - this is undefined, initiali-
6354 zation is performed later (when relocating to RAM).
6356 * Stack space is very limited. Avoid big data buffers or things like
6359 Having only the stack as writable memory limits means we cannot use
6360 normal global data to share information between the code. But it
6361 turned out that the implementation of U-Boot can be greatly
6362 simplified by making a global data structure (gd_t) available to all
6363 functions. We could pass a pointer to this data as argument to _all_
6364 functions, but this would bloat the code. Instead we use a feature of
6365 the GCC compiler (Global Register Variables) to share the data: we
6366 place a pointer (gd) to the global data into a register which we
6367 reserve for this purpose.
6369 When choosing a register for such a purpose we are restricted by the
6370 relevant (E)ABI specifications for the current architecture, and by
6371 GCC's implementation.
6373 For PowerPC, the following registers have specific use:
6375 R2: reserved for system use
6376 R3-R4: parameter passing and return values
6377 R5-R10: parameter passing
6378 R13: small data area pointer
6382 (U-Boot also uses R12 as internal GOT pointer. r12
6383 is a volatile register so r12 needs to be reset when
6384 going back and forth between asm and C)
6386 ==> U-Boot will use R2 to hold a pointer to the global data
6388 Note: on PPC, we could use a static initializer (since the
6389 address of the global data structure is known at compile time),
6390 but it turned out that reserving a register results in somewhat
6391 smaller code - although the code savings are not that big (on
6392 average for all boards 752 bytes for the whole U-Boot image,
6393 624 text + 127 data).
6395 On Blackfin, the normal C ABI (except for P3) is followed as documented here:
6396 http://docs.blackfin.uclinux.org/doku.php?id=application_binary_interface
6398 ==> U-Boot will use P3 to hold a pointer to the global data
6400 On ARM, the following registers are used:
6402 R0: function argument word/integer result
6403 R1-R3: function argument word
6404 R9: platform specific
6405 R10: stack limit (used only if stack checking is enabled)
6406 R11: argument (frame) pointer
6407 R12: temporary workspace
6410 R15: program counter
6412 ==> U-Boot will use R9 to hold a pointer to the global data
6414 Note: on ARM, only R_ARM_RELATIVE relocations are supported.
6416 On Nios II, the ABI is documented here:
6417 http://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf
6419 ==> U-Boot will use gp to hold a pointer to the global data
6421 Note: on Nios II, we give "-G0" option to gcc and don't use gp
6422 to access small data sections, so gp is free.
6424 On NDS32, the following registers are used:
6426 R0-R1: argument/return
6428 R15: temporary register for assembler
6429 R16: trampoline register
6430 R28: frame pointer (FP)
6431 R29: global pointer (GP)
6432 R30: link register (LP)
6433 R31: stack pointer (SP)
6434 PC: program counter (PC)
6436 ==> U-Boot will use R10 to hold a pointer to the global data
6438 NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope,
6439 or current versions of GCC may "optimize" the code too much.
6444 U-Boot runs in system state and uses physical addresses, i.e. the
6445 MMU is not used either for address mapping nor for memory protection.
6447 The available memory is mapped to fixed addresses using the memory
6448 controller. In this process, a contiguous block is formed for each
6449 memory type (Flash, SDRAM, SRAM), even when it consists of several
6450 physical memory banks.
6452 U-Boot is installed in the first 128 kB of the first Flash bank (on
6453 TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
6454 booting and sizing and initializing DRAM, the code relocates itself
6455 to the upper end of DRAM. Immediately below the U-Boot code some
6456 memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN
6457 configuration setting]. Below that, a structure with global Board
6458 Info data is placed, followed by the stack (growing downward).
6460 Additionally, some exception handler code is copied to the low 8 kB
6461 of DRAM (0x00000000 ... 0x00001FFF).
6463 So a typical memory configuration with 16 MB of DRAM could look like
6466 0x0000 0000 Exception Vector code
6469 0x0000 2000 Free for Application Use
6475 0x00FB FF20 Monitor Stack (Growing downward)
6476 0x00FB FFAC Board Info Data and permanent copy of global data
6477 0x00FC 0000 Malloc Arena
6480 0x00FE 0000 RAM Copy of Monitor Code
6481 ... eventually: LCD or video framebuffer
6482 ... eventually: pRAM (Protected RAM - unchanged by reset)
6483 0x00FF FFFF [End of RAM]
6486 System Initialization:
6487 ----------------------
6489 In the reset configuration, U-Boot starts at the reset entry point
6490 (on most PowerPC systems at address 0x00000100). Because of the reset
6491 configuration for CS0# this is a mirror of the on board Flash memory.
6492 To be able to re-map memory U-Boot then jumps to its link address.
6493 To be able to implement the initialization code in C, a (small!)
6494 initial stack is set up in the internal Dual Ported RAM (in case CPUs
6495 which provide such a feature like MPC8xx or MPC8260), or in a locked
6496 part of the data cache. After that, U-Boot initializes the CPU core,
6497 the caches and the SIU.
6499 Next, all (potentially) available memory banks are mapped using a
6500 preliminary mapping. For example, we put them on 512 MB boundaries
6501 (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
6502 on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
6503 programmed for SDRAM access. Using the temporary configuration, a
6504 simple memory test is run that determines the size of the SDRAM
6507 When there is more than one SDRAM bank, and the banks are of
6508 different size, the largest is mapped first. For equal size, the first
6509 bank (CS2#) is mapped first. The first mapping is always for address
6510 0x00000000, with any additional banks following immediately to create
6511 contiguous memory starting from 0.
6513 Then, the monitor installs itself at the upper end of the SDRAM area
6514 and allocates memory for use by malloc() and for the global Board
6515 Info data; also, the exception vector code is copied to the low RAM
6516 pages, and the final stack is set up.
6518 Only after this relocation will you have a "normal" C environment;
6519 until that you are restricted in several ways, mostly because you are
6520 running from ROM, and because the code will have to be relocated to a
6524 U-Boot Porting Guide:
6525 ----------------------
6527 [Based on messages by Jerry Van Baren in the U-Boot-Users mailing
6531 int main(int argc, char *argv[])
6533 sighandler_t no_more_time;
6535 signal(SIGALRM, no_more_time);
6536 alarm(PROJECT_DEADLINE - toSec (3 * WEEK));
6538 if (available_money > available_manpower) {
6539 Pay consultant to port U-Boot;
6543 Download latest U-Boot source;
6545 Subscribe to u-boot mailing list;
6548 email("Hi, I am new to U-Boot, how do I get started?");
6551 Read the README file in the top level directory;
6552 Read http://www.denx.de/twiki/bin/view/DULG/Manual;
6553 Read applicable doc/*.README;
6554 Read the source, Luke;
6555 /* find . -name "*.[chS]" | xargs grep -i <keyword> */
6558 if (available_money > toLocalCurrency ($2500))
6561 Add a lot of aggravation and time;
6563 if (a similar board exists) { /* hopefully... */
6564 cp -a board/<similar> board/<myboard>
6565 cp include/configs/<similar>.h include/configs/<myboard>.h
6567 Create your own board support subdirectory;
6568 Create your own board include/configs/<myboard>.h file;
6570 Edit new board/<myboard> files
6571 Edit new include/configs/<myboard>.h
6576 Add / modify source code;
6580 email("Hi, I am having problems...");
6582 Send patch file to the U-Boot email list;
6583 if (reasonable critiques)
6584 Incorporate improvements from email list code review;
6586 Defend code as written;
6592 void no_more_time (int sig)
6601 All contributions to U-Boot should conform to the Linux kernel
6602 coding style; see the file "Documentation/CodingStyle" and the script
6603 "scripts/Lindent" in your Linux kernel source directory.
6605 Source files originating from a different project (for example the
6606 MTD subsystem) are generally exempt from these guidelines and are not
6607 reformatted to ease subsequent migration to newer versions of those
6610 Please note that U-Boot is implemented in C (and to some small parts in
6611 Assembler); no C++ is used, so please do not use C++ style comments (//)
6614 Please also stick to the following formatting rules:
6615 - remove any trailing white space
6616 - use TAB characters for indentation and vertical alignment, not spaces
6617 - make sure NOT to use DOS '\r\n' line feeds
6618 - do not add more than 2 consecutive empty lines to source files
6619 - do not add trailing empty lines to source files
6621 Submissions which do not conform to the standards may be returned
6622 with a request to reformat the changes.
6628 Since the number of patches for U-Boot is growing, we need to
6629 establish some rules. Submissions which do not conform to these rules
6630 may be rejected, even when they contain important and valuable stuff.
6632 Please see http://www.denx.de/wiki/U-Boot/Patches for details.
6634 Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>;
6635 see http://lists.denx.de/mailman/listinfo/u-boot
6637 When you send a patch, please include the following information with
6640 * For bug fixes: a description of the bug and how your patch fixes
6641 this bug. Please try to include a way of demonstrating that the
6642 patch actually fixes something.
6644 * For new features: a description of the feature and your
6647 * A CHANGELOG entry as plaintext (separate from the patch)
6649 * For major contributions, your entry to the CREDITS file
6651 * When you add support for a new board, don't forget to add a
6652 maintainer e-mail address to the boards.cfg file, too.
6654 * If your patch adds new configuration options, don't forget to
6655 document these in the README file.
6657 * The patch itself. If you are using git (which is *strongly*
6658 recommended) you can easily generate the patch using the
6659 "git format-patch". If you then use "git send-email" to send it to
6660 the U-Boot mailing list, you will avoid most of the common problems
6661 with some other mail clients.
6663 If you cannot use git, use "diff -purN OLD NEW". If your version of
6664 diff does not support these options, then get the latest version of
6667 The current directory when running this command shall be the parent
6668 directory of the U-Boot source tree (i. e. please make sure that
6669 your patch includes sufficient directory information for the
6672 We prefer patches as plain text. MIME attachments are discouraged,
6673 and compressed attachments must not be used.
6675 * If one logical set of modifications affects or creates several
6676 files, all these changes shall be submitted in a SINGLE patch file.
6678 * Changesets that contain different, unrelated modifications shall be
6679 submitted as SEPARATE patches, one patch per changeset.
6684 * Before sending the patch, run the MAKEALL script on your patched
6685 source tree and make sure that no errors or warnings are reported
6686 for any of the boards.
6688 * Keep your modifications to the necessary minimum: A patch
6689 containing several unrelated changes or arbitrary reformats will be
6690 returned with a request to re-formatting / split it.
6692 * If you modify existing code, make sure that your new code does not
6693 add to the memory footprint of the code ;-) Small is beautiful!
6694 When adding new features, these should compile conditionally only
6695 (using #ifdef), and the resulting code with the new feature
6696 disabled must not need more memory than the old code without your
6699 * Remember that there is a size limit of 100 kB per message on the
6700 u-boot mailing list. Bigger patches will be moderated. If they are
6701 reasonable and not too big, they will be acknowledged. But patches
6702 bigger than the size limit should be avoided.
projects / karo-tx-uboot.git / blob