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_798870
699 CONFIG_TEGRA_SUPPORT_NON_SECURE
701 Support executing U-Boot in non-secure (NS) mode. Certain
702 impossible actions will be skipped if the CPU is in NS mode,
703 such as ARM architectural timer initialization.
706 - Linux Kernel Interface:
709 U-Boot stores all clock information in Hz
710 internally. For binary compatibility with older Linux
711 kernels (which expect the clocks passed in the
712 bd_info data to be in MHz) the environment variable
713 "clocks_in_mhz" can be defined so that U-Boot
714 converts clock data to MHZ before passing it to the
716 When CONFIG_CLOCKS_IN_MHZ is defined, a definition of
717 "clocks_in_mhz=1" is automatically included in the
720 CONFIG_MEMSIZE_IN_BYTES [relevant for MIPS only]
722 When transferring memsize parameter to Linux, some versions
723 expect it to be in bytes, others in MB.
724 Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes.
728 New kernel versions are expecting firmware settings to be
729 passed using flattened device trees (based on open firmware
733 * New libfdt-based support
734 * Adds the "fdt" command
735 * The bootm command automatically updates the fdt
737 OF_CPU - The proper name of the cpus node (only required for
738 MPC512X and MPC5xxx based boards).
739 OF_SOC - The proper name of the soc node (only required for
740 MPC512X and MPC5xxx based boards).
741 OF_TBCLK - The timebase frequency.
742 OF_STDOUT_PATH - The path to the console device
744 boards with QUICC Engines require OF_QE to set UCC MAC
747 CONFIG_OF_BOARD_SETUP
749 Board code has addition modification that it wants to make
750 to the flat device tree before handing it off to the kernel
752 CONFIG_OF_SYSTEM_SETUP
754 Other code has addition modification that it wants to make
755 to the flat device tree before handing it off to the kernel.
756 This causes ft_system_setup() to be called before booting
761 This define fills in the correct boot CPU in the boot
762 param header, the default value is zero if undefined.
766 U-Boot can detect if an IDE device is present or not.
767 If not, and this new config option is activated, U-Boot
768 removes the ATA node from the DTS before booting Linux,
769 so the Linux IDE driver does not probe the device and
770 crash. This is needed for buggy hardware (uc101) where
771 no pull down resistor is connected to the signal IDE5V_DD7.
773 CONFIG_MACH_TYPE [relevant for ARM only][mandatory]
775 This setting is mandatory for all boards that have only one
776 machine type and must be used to specify the machine type
777 number as it appears in the ARM machine registry
778 (see http://www.arm.linux.org.uk/developer/machines/).
779 Only boards that have multiple machine types supported
780 in a single configuration file and the machine type is
781 runtime discoverable, do not have to use this setting.
783 - vxWorks boot parameters:
785 bootvx constructs a valid bootline using the following
786 environments variables: bootfile, ipaddr, serverip, hostname.
787 It loads the vxWorks image pointed bootfile.
789 CONFIG_SYS_VXWORKS_BOOT_DEVICE - The vxworks device name
790 CONFIG_SYS_VXWORKS_MAC_PTR - Ethernet 6 byte MA -address
791 CONFIG_SYS_VXWORKS_SERVERNAME - Name of the server
792 CONFIG_SYS_VXWORKS_BOOT_ADDR - Address of boot parameters
794 CONFIG_SYS_VXWORKS_ADD_PARAMS
796 Add it at the end of the bootline. E.g "u=username pw=secret"
798 Note: If a "bootargs" environment is defined, it will overwride
799 the defaults discussed just above.
801 - Cache Configuration:
802 CONFIG_SYS_ICACHE_OFF - Do not enable instruction cache in U-Boot
803 CONFIG_SYS_DCACHE_OFF - Do not enable data cache in U-Boot
804 CONFIG_SYS_L2CACHE_OFF- Do not enable L2 cache in U-Boot
806 - Cache Configuration for ARM:
807 CONFIG_SYS_L2_PL310 - Enable support for ARM PL310 L2 cache
809 CONFIG_SYS_PL310_BASE - Physical base address of PL310
810 controller register space
815 Define this if you want support for Amba PrimeCell PL010 UARTs.
819 Define this if you want support for Amba PrimeCell PL011 UARTs.
823 If you have Amba PrimeCell PL011 UARTs, set this variable to
824 the clock speed of the UARTs.
828 If you have Amba PrimeCell PL010 or PL011 UARTs on your board,
829 define this to a list of base addresses for each (supported)
830 port. See e.g. include/configs/versatile.h
832 CONFIG_PL011_SERIAL_RLCR
834 Some vendor versions of PL011 serial ports (e.g. ST-Ericsson U8500)
835 have separate receive and transmit line control registers. Set
836 this variable to initialize the extra register.
838 CONFIG_PL011_SERIAL_FLUSH_ON_INIT
840 On some platforms (e.g. U8500) U-Boot is loaded by a second stage
841 boot loader that has already initialized the UART. Define this
842 variable to flush the UART at init time.
844 CONFIG_SERIAL_HW_FLOW_CONTROL
846 Define this variable to enable hw flow control in serial driver.
847 Current user of this option is drivers/serial/nsl16550.c driver
850 Depending on board, define exactly one serial port
851 (like CONFIG_8xx_CONS_SMC1, CONFIG_8xx_CONS_SMC2,
852 CONFIG_8xx_CONS_SCC1, ...), or switch off the serial
853 console by defining CONFIG_8xx_CONS_NONE
855 Note: if CONFIG_8xx_CONS_NONE is defined, the serial
856 port routines must be defined elsewhere
857 (i.e. serial_init(), serial_getc(), ...)
860 Enables console device for a color framebuffer. Needs following
861 defines (cf. smiLynxEM, i8042)
862 VIDEO_FB_LITTLE_ENDIAN graphic memory organisation
864 VIDEO_HW_RECTFILL graphic chip supports
867 VIDEO_HW_BITBLT graphic chip supports
868 bit-blit (cf. smiLynxEM)
869 VIDEO_VISIBLE_COLS visible pixel columns
871 VIDEO_VISIBLE_ROWS visible pixel rows
872 VIDEO_PIXEL_SIZE bytes per pixel
873 VIDEO_DATA_FORMAT graphic data format
874 (0-5, cf. cfb_console.c)
875 VIDEO_FB_ADRS framebuffer address
876 VIDEO_KBD_INIT_FCT keyboard int fct
877 (i.e. i8042_kbd_init())
878 VIDEO_TSTC_FCT test char fct
880 VIDEO_GETC_FCT get char fct
882 CONFIG_CONSOLE_CURSOR cursor drawing on/off
883 (requires blink timer
885 CONFIG_SYS_CONSOLE_BLINK_COUNT blink interval (cf. i8042.c)
886 CONFIG_CONSOLE_TIME display time/date info in
888 (requires CONFIG_CMD_DATE)
889 CONFIG_VIDEO_LOGO display Linux logo in
891 CONFIG_VIDEO_BMP_LOGO use bmp_logo.h instead of
892 linux_logo.h for logo.
893 Requires CONFIG_VIDEO_LOGO
894 CONFIG_CONSOLE_EXTRA_INFO
895 additional board info beside
898 When CONFIG_CFB_CONSOLE_ANSI is defined, console will support
899 a limited number of ANSI escape sequences (cursor control,
900 erase functions and limited graphics rendition control).
902 When CONFIG_CFB_CONSOLE is defined, video console is
903 default i/o. Serial console can be forced with
904 environment 'console=serial'.
906 When CONFIG_SILENT_CONSOLE is defined, all console
907 messages (by U-Boot and Linux!) can be silenced with
908 the "silent" environment variable. See
909 doc/README.silent for more information.
911 CONFIG_SYS_CONSOLE_BG_COL: define the backgroundcolor, default
913 CONFIG_SYS_CONSOLE_FG_COL: define the foregroundcolor, default
917 CONFIG_BAUDRATE - in bps
918 Select one of the baudrates listed in
919 CONFIG_SYS_BAUDRATE_TABLE, see below.
920 CONFIG_SYS_BRGCLK_PRESCALE, baudrate prescale
922 - Console Rx buffer length
923 With CONFIG_SYS_SMC_RXBUFLEN it is possible to define
924 the maximum receive buffer length for the SMC.
925 This option is actual only for 82xx and 8xx possible.
926 If using CONFIG_SYS_SMC_RXBUFLEN also CONFIG_SYS_MAXIDLE
927 must be defined, to setup the maximum idle timeout for
930 - Pre-Console Buffer:
931 Prior to the console being initialised (i.e. serial UART
932 initialised etc) all console output is silently discarded.
933 Defining CONFIG_PRE_CONSOLE_BUFFER will cause U-Boot to
934 buffer any console messages prior to the console being
935 initialised to a buffer of size CONFIG_PRE_CON_BUF_SZ
936 bytes located at CONFIG_PRE_CON_BUF_ADDR. The buffer is
937 a circular buffer, so if more than CONFIG_PRE_CON_BUF_SZ
938 bytes are output before the console is initialised, the
939 earlier bytes are discarded.
941 'Sane' compilers will generate smaller code if
942 CONFIG_PRE_CON_BUF_SZ is a power of 2
944 - Safe printf() functions
945 Define CONFIG_SYS_VSNPRINTF to compile in safe versions of
946 the printf() functions. These are defined in
947 include/vsprintf.h and include snprintf(), vsnprintf() and
948 so on. Code size increase is approximately 300-500 bytes.
949 If this option is not given then these functions will
950 silently discard their buffer size argument - this means
951 you are not getting any overflow checking in this case.
953 - Boot Delay: CONFIG_BOOTDELAY - in seconds
954 Delay before automatically booting the default image;
955 set to -1 to disable autoboot.
956 set to -2 to autoboot with no delay and not check for abort
957 (even when CONFIG_ZERO_BOOTDELAY_CHECK is defined).
959 See doc/README.autoboot for these options that
960 work with CONFIG_BOOTDELAY. None are required.
961 CONFIG_BOOT_RETRY_TIME
962 CONFIG_BOOT_RETRY_MIN
963 CONFIG_AUTOBOOT_KEYED
964 CONFIG_AUTOBOOT_PROMPT
965 CONFIG_AUTOBOOT_DELAY_STR
966 CONFIG_AUTOBOOT_STOP_STR
967 CONFIG_AUTOBOOT_DELAY_STR2
968 CONFIG_AUTOBOOT_STOP_STR2
969 CONFIG_ZERO_BOOTDELAY_CHECK
970 CONFIG_RESET_TO_RETRY
974 Only needed when CONFIG_BOOTDELAY is enabled;
975 define a command string that is automatically executed
976 when no character is read on the console interface
977 within "Boot Delay" after reset.
980 This can be used to pass arguments to the bootm
981 command. The value of CONFIG_BOOTARGS goes into the
982 environment value "bootargs".
984 CONFIG_RAMBOOT and CONFIG_NFSBOOT
985 The value of these goes into the environment as
986 "ramboot" and "nfsboot" respectively, and can be used
987 as a convenience, when switching between booting from
991 CONFIG_BOOTCOUNT_LIMIT
992 Implements a mechanism for detecting a repeating reboot
994 http://www.denx.de/wiki/view/DULG/UBootBootCountLimit
997 If no softreset save registers are found on the hardware
998 "bootcount" is stored in the environment. To prevent a
999 saveenv on all reboots, the environment variable
1000 "upgrade_available" is used. If "upgrade_available" is
1001 0, "bootcount" is always 0, if "upgrade_available" is
1002 1 "bootcount" is incremented in the environment.
1003 So the Userspace Applikation must set the "upgrade_available"
1004 and "bootcount" variable to 0, if a boot was successfully.
1006 - Pre-Boot Commands:
1009 When this option is #defined, the existence of the
1010 environment variable "preboot" will be checked
1011 immediately before starting the CONFIG_BOOTDELAY
1012 countdown and/or running the auto-boot command resp.
1013 entering interactive mode.
1015 This feature is especially useful when "preboot" is
1016 automatically generated or modified. For an example
1017 see the LWMON board specific code: here "preboot" is
1018 modified when the user holds down a certain
1019 combination of keys on the (special) keyboard when
1022 - Serial Download Echo Mode:
1024 If defined to 1, all characters received during a
1025 serial download (using the "loads" command) are
1026 echoed back. This might be needed by some terminal
1027 emulations (like "cu"), but may as well just take
1028 time on others. This setting #define's the initial
1029 value of the "loads_echo" environment variable.
1031 - Kgdb Serial Baudrate: (if CONFIG_CMD_KGDB is defined)
1032 CONFIG_KGDB_BAUDRATE
1033 Select one of the baudrates listed in
1034 CONFIG_SYS_BAUDRATE_TABLE, see below.
1036 - Monitor Functions:
1037 Monitor commands can be included or excluded
1038 from the build by using the #include files
1039 <config_cmd_all.h> and #undef'ing unwanted
1040 commands, or using <config_cmd_default.h>
1041 and augmenting with additional #define's
1042 for wanted commands.
1044 The default command configuration includes all commands
1045 except those marked below with a "*".
1047 CONFIG_CMD_AES AES 128 CBC encrypt/decrypt
1048 CONFIG_CMD_ASKENV * ask for env variable
1049 CONFIG_CMD_BDI bdinfo
1050 CONFIG_CMD_BEDBUG * Include BedBug Debugger
1051 CONFIG_CMD_BMP * BMP support
1052 CONFIG_CMD_BSP * Board specific commands
1053 CONFIG_CMD_BOOTD bootd
1054 CONFIG_CMD_BOOTI * ARM64 Linux kernel Image support
1055 CONFIG_CMD_CACHE * icache, dcache
1056 CONFIG_CMD_CLK * clock command support
1057 CONFIG_CMD_CONSOLE coninfo
1058 CONFIG_CMD_CRC32 * crc32
1059 CONFIG_CMD_DATE * support for RTC, date/time...
1060 CONFIG_CMD_DHCP * DHCP support
1061 CONFIG_CMD_DIAG * Diagnostics
1062 CONFIG_CMD_DS4510 * ds4510 I2C gpio commands
1063 CONFIG_CMD_DS4510_INFO * ds4510 I2C info command
1064 CONFIG_CMD_DS4510_MEM * ds4510 I2C eeprom/sram commansd
1065 CONFIG_CMD_DS4510_RST * ds4510 I2C rst command
1066 CONFIG_CMD_DTT * Digital Therm and Thermostat
1067 CONFIG_CMD_ECHO echo arguments
1068 CONFIG_CMD_EDITENV edit env variable
1069 CONFIG_CMD_EEPROM * EEPROM read/write support
1070 CONFIG_CMD_ELF * bootelf, bootvx
1071 CONFIG_CMD_ENV_CALLBACK * display details about env callbacks
1072 CONFIG_CMD_ENV_FLAGS * display details about env flags
1073 CONFIG_CMD_ENV_EXISTS * check existence of env variable
1074 CONFIG_CMD_EXPORTENV * export the environment
1075 CONFIG_CMD_EXT2 * ext2 command support
1076 CONFIG_CMD_EXT4 * ext4 command support
1077 CONFIG_CMD_FS_GENERIC * filesystem commands (e.g. load, ls)
1078 that work for multiple fs types
1079 CONFIG_CMD_FS_UUID * Look up a filesystem UUID
1080 CONFIG_CMD_SAVEENV saveenv
1081 CONFIG_CMD_FDC * Floppy Disk Support
1082 CONFIG_CMD_FAT * FAT command support
1083 CONFIG_CMD_FLASH flinfo, erase, protect
1084 CONFIG_CMD_FPGA FPGA device initialization support
1085 CONFIG_CMD_FUSE * Device fuse support
1086 CONFIG_CMD_GETTIME * Get time since boot
1087 CONFIG_CMD_GO * the 'go' command (exec code)
1088 CONFIG_CMD_GREPENV * search environment
1089 CONFIG_CMD_HASH * calculate hash / digest
1090 CONFIG_CMD_HWFLOW * RTS/CTS hw flow control
1091 CONFIG_CMD_I2C * I2C serial bus support
1092 CONFIG_CMD_IDE * IDE harddisk support
1093 CONFIG_CMD_IMI iminfo
1094 CONFIG_CMD_IMLS List all images found in NOR flash
1095 CONFIG_CMD_IMLS_NAND * List all images found in NAND flash
1096 CONFIG_CMD_IMMAP * IMMR dump support
1097 CONFIG_CMD_IOTRACE * I/O tracing for debugging
1098 CONFIG_CMD_IMPORTENV * import an environment
1099 CONFIG_CMD_INI * import data from an ini file into the env
1100 CONFIG_CMD_IRQ * irqinfo
1101 CONFIG_CMD_ITEST Integer/string test of 2 values
1102 CONFIG_CMD_JFFS2 * JFFS2 Support
1103 CONFIG_CMD_KGDB * kgdb
1104 CONFIG_CMD_LDRINFO * ldrinfo (display Blackfin loader)
1105 CONFIG_CMD_LINK_LOCAL * link-local IP address auto-configuration
1107 CONFIG_CMD_LOADB loadb
1108 CONFIG_CMD_LOADS loads
1109 CONFIG_CMD_MD5SUM * print md5 message digest
1110 (requires CONFIG_CMD_MEMORY and CONFIG_MD5)
1111 CONFIG_CMD_MEMINFO * Display detailed memory information
1112 CONFIG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base,
1114 CONFIG_CMD_MEMTEST * mtest
1115 CONFIG_CMD_MISC Misc functions like sleep etc
1116 CONFIG_CMD_MMC * MMC memory mapped support
1117 CONFIG_CMD_MII * MII utility commands
1118 CONFIG_CMD_MTDPARTS * MTD partition support
1119 CONFIG_CMD_NAND * NAND support
1120 CONFIG_CMD_NET bootp, tftpboot, rarpboot
1121 CONFIG_CMD_NFS NFS support
1122 CONFIG_CMD_PCA953X * PCA953x I2C gpio commands
1123 CONFIG_CMD_PCA953X_INFO * PCA953x I2C gpio info command
1124 CONFIG_CMD_PCI * pciinfo
1125 CONFIG_CMD_PCMCIA * PCMCIA support
1126 CONFIG_CMD_PING * send ICMP ECHO_REQUEST to network
1128 CONFIG_CMD_PORTIO * Port I/O
1129 CONFIG_CMD_READ * Read raw data from partition
1130 CONFIG_CMD_REGINFO * Register dump
1131 CONFIG_CMD_RUN run command in env variable
1132 CONFIG_CMD_SANDBOX * sb command to access sandbox features
1133 CONFIG_CMD_SAVES * save S record dump
1134 CONFIG_CMD_SCSI * SCSI Support
1135 CONFIG_CMD_SDRAM * print SDRAM configuration information
1136 (requires CONFIG_CMD_I2C)
1137 CONFIG_CMD_SETGETDCR Support for DCR Register access
1139 CONFIG_CMD_SF * Read/write/erase SPI NOR flash
1140 CONFIG_CMD_SHA1SUM * print sha1 memory digest
1141 (requires CONFIG_CMD_MEMORY)
1142 CONFIG_CMD_SOFTSWITCH * Soft switch setting command for BF60x
1143 CONFIG_CMD_SOURCE "source" command Support
1144 CONFIG_CMD_SPI * SPI serial bus support
1145 CONFIG_CMD_TFTPSRV * TFTP transfer in server mode
1146 CONFIG_CMD_TFTPPUT * TFTP put command (upload)
1147 CONFIG_CMD_TIME * run command and report execution time (ARM specific)
1148 CONFIG_CMD_TIMER * access to the system tick timer
1149 CONFIG_CMD_USB * USB support
1150 CONFIG_CMD_CDP * Cisco Discover Protocol support
1151 CONFIG_CMD_MFSL * Microblaze FSL support
1152 CONFIG_CMD_XIMG Load part of Multi Image
1153 CONFIG_CMD_UUID * Generate random UUID or GUID string
1155 EXAMPLE: If you want all functions except of network
1156 support you can write:
1158 #include "config_cmd_all.h"
1159 #undef CONFIG_CMD_NET
1162 fdt (flattened device tree) command: CONFIG_OF_LIBFDT
1164 Note: Don't enable the "icache" and "dcache" commands
1165 (configuration option CONFIG_CMD_CACHE) unless you know
1166 what you (and your U-Boot users) are doing. Data
1167 cache cannot be enabled on systems like the 8xx or
1168 8260 (where accesses to the IMMR region must be
1169 uncached), and it cannot be disabled on all other
1170 systems where we (mis-) use the data cache to hold an
1171 initial stack and some data.
1174 XXX - this list needs to get updated!
1176 - Regular expression support:
1178 If this variable is defined, U-Boot is linked against
1179 the SLRE (Super Light Regular Expression) library,
1180 which adds regex support to some commands, as for
1181 example "env grep" and "setexpr".
1185 If this variable is defined, U-Boot will use a device tree
1186 to configure its devices, instead of relying on statically
1187 compiled #defines in the board file. This option is
1188 experimental and only available on a few boards. The device
1189 tree is available in the global data as gd->fdt_blob.
1191 U-Boot needs to get its device tree from somewhere. This can
1192 be done using one of the two options below:
1195 If this variable is defined, U-Boot will embed a device tree
1196 binary in its image. This device tree file should be in the
1197 board directory and called <soc>-<board>.dts. The binary file
1198 is then picked up in board_init_f() and made available through
1199 the global data structure as gd->blob.
1202 If this variable is defined, U-Boot will build a device tree
1203 binary. It will be called u-boot.dtb. Architecture-specific
1204 code will locate it at run-time. Generally this works by:
1206 cat u-boot.bin u-boot.dtb >image.bin
1208 and in fact, U-Boot does this for you, creating a file called
1209 u-boot-dtb.bin which is useful in the common case. You can
1210 still use the individual files if you need something more
1215 If this variable is defined, it enables watchdog
1216 support for the SoC. There must be support in the SoC
1217 specific code for a watchdog. For the 8xx and 8260
1218 CPUs, the SIU Watchdog feature is enabled in the SYPCR
1219 register. When supported for a specific SoC is
1220 available, then no further board specific code should
1221 be needed to use it.
1224 When using a watchdog circuitry external to the used
1225 SoC, then define this variable and provide board
1226 specific code for the "hw_watchdog_reset" function.
1228 CONFIG_AT91_HW_WDT_TIMEOUT
1229 specify the timeout in seconds. default 2 seconds.
1232 CONFIG_VERSION_VARIABLE
1233 If this variable is defined, an environment variable
1234 named "ver" is created by U-Boot showing the U-Boot
1235 version as printed by the "version" command.
1236 Any change to this variable will be reverted at the
1241 When CONFIG_CMD_DATE is selected, the type of the RTC
1242 has to be selected, too. Define exactly one of the
1245 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx
1246 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC
1247 CONFIG_RTC_MC13XXX - use MC13783 or MC13892 RTC
1248 CONFIG_RTC_MC146818 - use MC146818 RTC
1249 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC
1250 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC
1251 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC
1252 CONFIG_RTC_DS1339 - use Maxim, Inc. DS1339 RTC
1253 CONFIG_RTC_DS164x - use Dallas DS164x RTC
1254 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC
1255 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC
1256 CONFIG_SYS_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337
1257 CONFIG_SYS_RV3029_TCR - enable trickle charger on
1260 Note that if the RTC uses I2C, then the I2C interface
1261 must also be configured. See I2C Support, below.
1264 CONFIG_PCA953X - use NXP's PCA953X series I2C GPIO
1266 The CONFIG_SYS_I2C_PCA953X_WIDTH option specifies a list of
1267 chip-ngpio pairs that tell the PCA953X driver the number of
1268 pins supported by a particular chip.
1270 Note that if the GPIO device uses I2C, then the I2C interface
1271 must also be configured. See I2C Support, below.
1274 When CONFIG_IO_TRACE is selected, U-Boot intercepts all I/O
1275 accesses and can checksum them or write a list of them out
1276 to memory. See the 'iotrace' command for details. This is
1277 useful for testing device drivers since it can confirm that
1278 the driver behaves the same way before and after a code
1279 change. Currently this is supported on sandbox and arm. To
1280 add support for your architecture, add '#include <iotrace.h>'
1281 to the bottom of arch/<arch>/include/asm/io.h and test.
1283 Example output from the 'iotrace stats' command is below.
1284 Note that if the trace buffer is exhausted, the checksum will
1285 still continue to operate.
1288 Start: 10000000 (buffer start address)
1289 Size: 00010000 (buffer size)
1290 Offset: 00000120 (current buffer offset)
1291 Output: 10000120 (start + offset)
1292 Count: 00000018 (number of trace records)
1293 CRC32: 9526fb66 (CRC32 of all trace records)
1295 - Timestamp Support:
1297 When CONFIG_TIMESTAMP is selected, the timestamp
1298 (date and time) of an image is printed by image
1299 commands like bootm or iminfo. This option is
1300 automatically enabled when you select CONFIG_CMD_DATE .
1302 - Partition Labels (disklabels) Supported:
1303 Zero or more of the following:
1304 CONFIG_MAC_PARTITION Apple's MacOS partition table.
1305 CONFIG_DOS_PARTITION MS Dos partition table, traditional on the
1306 Intel architecture, USB sticks, etc.
1307 CONFIG_ISO_PARTITION ISO partition table, used on CDROM etc.
1308 CONFIG_EFI_PARTITION GPT partition table, common when EFI is the
1309 bootloader. Note 2TB partition limit; see
1311 CONFIG_MTD_PARTITIONS Memory Technology Device partition table.
1313 If IDE or SCSI support is enabled (CONFIG_CMD_IDE or
1314 CONFIG_CMD_SCSI) you must configure support for at
1315 least one non-MTD partition type as well.
1318 CONFIG_IDE_RESET_ROUTINE - this is defined in several
1319 board configurations files but used nowhere!
1321 CONFIG_IDE_RESET - is this is defined, IDE Reset will
1322 be performed by calling the function
1323 ide_set_reset(int reset)
1324 which has to be defined in a board specific file
1329 Set this to enable ATAPI support.
1334 Set this to enable support for disks larger than 137GB
1335 Also look at CONFIG_SYS_64BIT_LBA.
1336 Whithout these , LBA48 support uses 32bit variables and will 'only'
1337 support disks up to 2.1TB.
1339 CONFIG_SYS_64BIT_LBA:
1340 When enabled, makes the IDE subsystem use 64bit sector addresses.
1344 At the moment only there is only support for the
1345 SYM53C8XX SCSI controller; define
1346 CONFIG_SCSI_SYM53C8XX to enable it.
1348 CONFIG_SYS_SCSI_MAX_LUN [8], CONFIG_SYS_SCSI_MAX_SCSI_ID [7] and
1349 CONFIG_SYS_SCSI_MAX_DEVICE [CONFIG_SYS_SCSI_MAX_SCSI_ID *
1350 CONFIG_SYS_SCSI_MAX_LUN] can be adjusted to define the
1351 maximum numbers of LUNs, SCSI ID's and target
1353 CONFIG_SYS_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz)
1355 The environment variable 'scsidevs' is set to the number of
1356 SCSI devices found during the last scan.
1358 - NETWORK Support (PCI):
1360 Support for Intel 8254x/8257x gigabit chips.
1363 Utility code for direct access to the SPI bus on Intel 8257x.
1364 This does not do anything useful unless you set at least one
1365 of CONFIG_CMD_E1000 or CONFIG_E1000_SPI_GENERIC.
1367 CONFIG_E1000_SPI_GENERIC
1368 Allow generic access to the SPI bus on the Intel 8257x, for
1369 example with the "sspi" command.
1372 Management command for E1000 devices. When used on devices
1373 with SPI support you can reprogram the EEPROM from U-Boot.
1375 CONFIG_E1000_FALLBACK_MAC
1376 default MAC for empty EEPROM after production.
1379 Support for Intel 82557/82559/82559ER chips.
1380 Optional CONFIG_EEPRO100_SROM_WRITE enables EEPROM
1381 write routine for first time initialisation.
1384 Support for Digital 2114x chips.
1385 Optional CONFIG_TULIP_SELECT_MEDIA for board specific
1386 modem chip initialisation (KS8761/QS6611).
1389 Support for National dp83815 chips.
1392 Support for National dp8382[01] gigabit chips.
1394 - NETWORK Support (other):
1396 CONFIG_DRIVER_AT91EMAC
1397 Support for AT91RM9200 EMAC.
1400 Define this to use reduced MII inteface
1402 CONFIG_DRIVER_AT91EMAC_QUIET
1403 If this defined, the driver is quiet.
1404 The driver doen't show link status messages.
1406 CONFIG_CALXEDA_XGMAC
1407 Support for the Calxeda XGMAC device
1410 Support for SMSC's LAN91C96 chips.
1412 CONFIG_LAN91C96_BASE
1413 Define this to hold the physical address
1414 of the LAN91C96's I/O space
1416 CONFIG_LAN91C96_USE_32_BIT
1417 Define this to enable 32 bit addressing
1420 Support for SMSC's LAN91C111 chip
1422 CONFIG_SMC91111_BASE
1423 Define this to hold the physical address
1424 of the device (I/O space)
1426 CONFIG_SMC_USE_32_BIT
1427 Define this if data bus is 32 bits
1429 CONFIG_SMC_USE_IOFUNCS
1430 Define this to use i/o functions instead of macros
1431 (some hardware wont work with macros)
1433 CONFIG_DRIVER_TI_EMAC
1434 Support for davinci emac
1436 CONFIG_SYS_DAVINCI_EMAC_PHY_COUNT
1437 Define this if you have more then 3 PHYs.
1440 Support for Faraday's FTGMAC100 Gigabit SoC Ethernet
1442 CONFIG_FTGMAC100_EGIGA
1443 Define this to use GE link update with gigabit PHY.
1444 Define this if FTGMAC100 is connected to gigabit PHY.
1445 If your system has 10/100 PHY only, it might not occur
1446 wrong behavior. Because PHY usually return timeout or
1447 useless data when polling gigabit status and gigabit
1448 control registers. This behavior won't affect the
1449 correctnessof 10/100 link speed update.
1452 Support for SMSC's LAN911x and LAN921x chips
1455 Define this to hold the physical address
1456 of the device (I/O space)
1458 CONFIG_SMC911X_32_BIT
1459 Define this if data bus is 32 bits
1461 CONFIG_SMC911X_16_BIT
1462 Define this if data bus is 16 bits. If your processor
1463 automatically converts one 32 bit word to two 16 bit
1464 words you may also try CONFIG_SMC911X_32_BIT.
1467 Support for Renesas on-chip Ethernet controller
1469 CONFIG_SH_ETHER_USE_PORT
1470 Define the number of ports to be used
1472 CONFIG_SH_ETHER_PHY_ADDR
1473 Define the ETH PHY's address
1475 CONFIG_SH_ETHER_CACHE_WRITEBACK
1476 If this option is set, the driver enables cache flush.
1480 Support for PWM modul on the imx6.
1484 Support TPM devices.
1487 Support for i2c bus TPM devices. Only one device
1488 per system is supported at this time.
1490 CONFIG_TPM_TIS_I2C_BUS_NUMBER
1491 Define the the i2c bus number for the TPM device
1493 CONFIG_TPM_TIS_I2C_SLAVE_ADDRESS
1494 Define the TPM's address on the i2c bus
1496 CONFIG_TPM_TIS_I2C_BURST_LIMITATION
1497 Define the burst count bytes upper limit
1499 CONFIG_TPM_ATMEL_TWI
1500 Support for Atmel TWI TPM device. Requires I2C support.
1503 Support for generic parallel port TPM devices. Only one device
1504 per system is supported at this time.
1506 CONFIG_TPM_TIS_BASE_ADDRESS
1507 Base address where the generic TPM device is mapped
1508 to. Contemporary x86 systems usually map it at
1512 Add tpm monitor functions.
1513 Requires CONFIG_TPM. If CONFIG_TPM_AUTH_SESSIONS is set, also
1514 provides monitor access to authorized functions.
1517 Define this to enable the TPM support library which provides
1518 functional interfaces to some TPM commands.
1519 Requires support for a TPM device.
1521 CONFIG_TPM_AUTH_SESSIONS
1522 Define this to enable authorized functions in the TPM library.
1523 Requires CONFIG_TPM and CONFIG_SHA1.
1526 At the moment only the UHCI host controller is
1527 supported (PIP405, MIP405, MPC5200); define
1528 CONFIG_USB_UHCI to enable it.
1529 define CONFIG_USB_KEYBOARD to enable the USB Keyboard
1530 and define CONFIG_USB_STORAGE to enable the USB
1533 Supported are USB Keyboards and USB Floppy drives
1535 MPC5200 USB requires additional defines:
1537 for 528 MHz Clock: 0x0001bbbb
1541 for differential drivers: 0x00001000
1542 for single ended drivers: 0x00005000
1543 for differential drivers on PSC3: 0x00000100
1544 for single ended drivers on PSC3: 0x00004100
1545 CONFIG_SYS_USB_EVENT_POLL
1546 May be defined to allow interrupt polling
1547 instead of using asynchronous interrupts
1549 CONFIG_USB_EHCI_TXFIFO_THRESH enables setting of the
1550 txfilltuning field in the EHCI controller on reset.
1552 CONFIG_USB_DWC2_REG_ADDR the physical CPU address of the DWC2
1553 HW module registers.
1556 Define the below if you wish to use the USB console.
1557 Once firmware is rebuilt from a serial console issue the
1558 command "setenv stdin usbtty; setenv stdout usbtty" and
1559 attach your USB cable. The Unix command "dmesg" should print
1560 it has found a new device. The environment variable usbtty
1561 can be set to gserial or cdc_acm to enable your device to
1562 appear to a USB host as a Linux gserial device or a
1563 Common Device Class Abstract Control Model serial device.
1564 If you select usbtty = gserial you should be able to enumerate
1566 # modprobe usbserial vendor=0xVendorID product=0xProductID
1567 else if using cdc_acm, simply setting the environment
1568 variable usbtty to be cdc_acm should suffice. The following
1569 might be defined in YourBoardName.h
1572 Define this to build a UDC device
1575 Define this to have a tty type of device available to
1576 talk to the UDC device
1579 Define this to enable the high speed support for usb
1580 device and usbtty. If this feature is enabled, a routine
1581 int is_usbd_high_speed(void)
1582 also needs to be defined by the driver to dynamically poll
1583 whether the enumeration has succeded at high speed or full
1586 CONFIG_SYS_CONSOLE_IS_IN_ENV
1587 Define this if you want stdin, stdout &/or stderr to
1591 CONFIG_SYS_USB_EXTC_CLK 0xBLAH
1592 Derive USB clock from external clock "blah"
1593 - CONFIG_SYS_USB_EXTC_CLK 0x02
1595 CONFIG_SYS_USB_BRG_CLK 0xBLAH
1596 Derive USB clock from brgclk
1597 - CONFIG_SYS_USB_BRG_CLK 0x04
1599 If you have a USB-IF assigned VendorID then you may wish to
1600 define your own vendor specific values either in BoardName.h
1601 or directly in usbd_vendor_info.h. If you don't define
1602 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME,
1603 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot
1604 should pretend to be a Linux device to it's target host.
1606 CONFIG_USBD_MANUFACTURER
1607 Define this string as the name of your company for
1608 - CONFIG_USBD_MANUFACTURER "my company"
1610 CONFIG_USBD_PRODUCT_NAME
1611 Define this string as the name of your product
1612 - CONFIG_USBD_PRODUCT_NAME "acme usb device"
1614 CONFIG_USBD_VENDORID
1615 Define this as your assigned Vendor ID from the USB
1616 Implementors Forum. This *must* be a genuine Vendor ID
1617 to avoid polluting the USB namespace.
1618 - CONFIG_USBD_VENDORID 0xFFFF
1620 CONFIG_USBD_PRODUCTID
1621 Define this as the unique Product ID
1623 - CONFIG_USBD_PRODUCTID 0xFFFF
1625 - ULPI Layer Support:
1626 The ULPI (UTMI Low Pin (count) Interface) PHYs are supported via
1627 the generic ULPI layer. The generic layer accesses the ULPI PHY
1628 via the platform viewport, so you need both the genric layer and
1629 the viewport enabled. Currently only Chipidea/ARC based
1630 viewport is supported.
1631 To enable the ULPI layer support, define CONFIG_USB_ULPI and
1632 CONFIG_USB_ULPI_VIEWPORT in your board configuration file.
1633 If your ULPI phy needs a different reference clock than the
1634 standard 24 MHz then you have to define CONFIG_ULPI_REF_CLK to
1635 the appropriate value in Hz.
1638 The MMC controller on the Intel PXA is supported. To
1639 enable this define CONFIG_MMC. The MMC can be
1640 accessed from the boot prompt by mapping the device
1641 to physical memory similar to flash. Command line is
1642 enabled with CONFIG_CMD_MMC. The MMC driver also works with
1643 the FAT fs. This is enabled with CONFIG_CMD_FAT.
1646 Support for Renesas on-chip MMCIF controller
1648 CONFIG_SH_MMCIF_ADDR
1649 Define the base address of MMCIF registers
1652 Define the clock frequency for MMCIF
1655 Enable the generic MMC driver
1657 CONFIG_SUPPORT_EMMC_BOOT
1658 Enable some additional features of the eMMC boot partitions.
1660 CONFIG_SUPPORT_EMMC_RPMB
1661 Enable the commands for reading, writing and programming the
1662 key for the Replay Protection Memory Block partition in eMMC.
1664 - USB Device Firmware Update (DFU) class support:
1666 This enables the USB portion of the DFU USB class
1669 This enables the command "dfu" which is used to have
1670 U-Boot create a DFU class device via USB. This command
1671 requires that the "dfu_alt_info" environment variable be
1672 set and define the alt settings to expose to the host.
1675 This enables support for exposing (e)MMC devices via DFU.
1678 This enables support for exposing NAND devices via DFU.
1681 This enables support for exposing RAM via DFU.
1682 Note: DFU spec refer to non-volatile memory usage, but
1683 allow usages beyond the scope of spec - here RAM usage,
1684 one that would help mostly the developer.
1686 CONFIG_SYS_DFU_DATA_BUF_SIZE
1687 Dfu transfer uses a buffer before writing data to the
1688 raw storage device. Make the size (in bytes) of this buffer
1689 configurable. The size of this buffer is also configurable
1690 through the "dfu_bufsiz" environment variable.
1692 CONFIG_SYS_DFU_MAX_FILE_SIZE
1693 When updating files rather than the raw storage device,
1694 we use a static buffer to copy the file into and then write
1695 the buffer once we've been given the whole file. Define
1696 this to the maximum filesize (in bytes) for the buffer.
1697 Default is 4 MiB if undefined.
1699 DFU_DEFAULT_POLL_TIMEOUT
1700 Poll timeout [ms], is the timeout a device can send to the
1701 host. The host must wait for this timeout before sending
1702 a subsequent DFU_GET_STATUS request to the device.
1704 DFU_MANIFEST_POLL_TIMEOUT
1705 Poll timeout [ms], which the device sends to the host when
1706 entering dfuMANIFEST state. Host waits this timeout, before
1707 sending again an USB request to the device.
1709 - USB Device Android Fastboot support:
1711 This enables the command "fastboot" which enables the Android
1712 fastboot mode for the platform's USB device. Fastboot is a USB
1713 protocol for downloading images, flashing and device control
1714 used on Android devices.
1715 See doc/README.android-fastboot for more information.
1717 CONFIG_ANDROID_BOOT_IMAGE
1718 This enables support for booting images which use the Android
1719 image format header.
1721 CONFIG_USB_FASTBOOT_BUF_ADDR
1722 The fastboot protocol requires a large memory buffer for
1723 downloads. Define this to the starting RAM address to use for
1726 CONFIG_USB_FASTBOOT_BUF_SIZE
1727 The fastboot protocol requires a large memory buffer for
1728 downloads. This buffer should be as large as possible for a
1729 platform. Define this to the size available RAM for fastboot.
1731 CONFIG_FASTBOOT_FLASH
1732 The fastboot protocol includes a "flash" command for writing
1733 the downloaded image to a non-volatile storage device. Define
1734 this to enable the "fastboot flash" command.
1736 CONFIG_FASTBOOT_FLASH_MMC_DEV
1737 The fastboot "flash" command requires additional information
1738 regarding the non-volatile storage device. Define this to
1739 the eMMC device that fastboot should use to store the image.
1741 CONFIG_FASTBOOT_GPT_NAME
1742 The fastboot "flash" command supports writing the downloaded
1743 image to the Protective MBR and the Primary GUID Partition
1744 Table. (Additionally, this downloaded image is post-processed
1745 to generate and write the Backup GUID Partition Table.)
1746 This occurs when the specified "partition name" on the
1747 "fastboot flash" command line matches this value.
1748 Default is GPT_ENTRY_NAME (currently "gpt") if undefined.
1750 - Journaling Flash filesystem support:
1751 CONFIG_JFFS2_NAND, CONFIG_JFFS2_NAND_OFF, CONFIG_JFFS2_NAND_SIZE,
1752 CONFIG_JFFS2_NAND_DEV
1753 Define these for a default partition on a NAND device
1755 CONFIG_SYS_JFFS2_FIRST_SECTOR,
1756 CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS
1757 Define these for a default partition on a NOR device
1759 CONFIG_SYS_JFFS_CUSTOM_PART
1760 Define this to create an own partition. You have to provide a
1761 function struct part_info* jffs2_part_info(int part_num)
1763 If you define only one JFFS2 partition you may also want to
1764 #define CONFIG_SYS_JFFS_SINGLE_PART 1
1765 to disable the command chpart. This is the default when you
1766 have not defined a custom partition
1768 - FAT(File Allocation Table) filesystem write function support:
1771 Define this to enable support for saving memory data as a
1772 file in FAT formatted partition.
1774 This will also enable the command "fatwrite" enabling the
1775 user to write files to FAT.
1777 CBFS (Coreboot Filesystem) support
1780 Define this to enable support for reading from a Coreboot
1781 filesystem. Available commands are cbfsinit, cbfsinfo, cbfsls
1784 - FAT(File Allocation Table) filesystem cluster size:
1785 CONFIG_FS_FAT_MAX_CLUSTSIZE
1787 Define the max cluster size for fat operations else
1788 a default value of 65536 will be defined.
1793 Define this to enable standard (PC-Style) keyboard
1797 Standard PC keyboard driver with US (is default) and
1798 GERMAN key layout (switch via environment 'keymap=de') support.
1799 Export function i8042_kbd_init, i8042_tstc and i8042_getc
1800 for cfb_console. Supports cursor blinking.
1803 Enables a Chrome OS keyboard using the CROS_EC interface.
1804 This uses CROS_EC to communicate with a second microcontroller
1805 which provides key scans on request.
1810 Define this to enable video support (for output to
1813 CONFIG_VIDEO_CT69000
1815 Enable Chips & Technologies 69000 Video chip
1817 CONFIG_VIDEO_SMI_LYNXEM
1818 Enable Silicon Motion SMI 712/710/810 Video chip. The
1819 video output is selected via environment 'videoout'
1820 (1 = LCD and 2 = CRT). If videoout is undefined, CRT is
1823 For the CT69000 and SMI_LYNXEM drivers, videomode is
1824 selected via environment 'videomode'. Two different ways
1826 - "videomode=num" 'num' is a standard LiLo mode numbers.
1827 Following standard modes are supported (* is default):
1829 Colors 640x480 800x600 1024x768 1152x864 1280x1024
1830 -------------+---------------------------------------------
1831 8 bits | 0x301* 0x303 0x305 0x161 0x307
1832 15 bits | 0x310 0x313 0x316 0x162 0x319
1833 16 bits | 0x311 0x314 0x317 0x163 0x31A
1834 24 bits | 0x312 0x315 0x318 ? 0x31B
1835 -------------+---------------------------------------------
1836 (i.e. setenv videomode 317; saveenv; reset;)
1838 - "videomode=bootargs" all the video parameters are parsed
1839 from the bootargs. (See drivers/video/videomodes.c)
1842 CONFIG_VIDEO_SED13806
1843 Enable Epson SED13806 driver. This driver supports 8bpp
1844 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP
1845 or CONFIG_VIDEO_SED13806_16BPP
1848 Enable the Freescale DIU video driver. Reference boards for
1849 SOCs that have a DIU should define this macro to enable DIU
1850 support, and should also define these other macros:
1856 CONFIG_VIDEO_SW_CURSOR
1857 CONFIG_VGA_AS_SINGLE_DEVICE
1859 CONFIG_VIDEO_BMP_LOGO
1861 The DIU driver will look for the 'video-mode' environment
1862 variable, and if defined, enable the DIU as a console during
1863 boot. See the documentation file README.video for a
1864 description of this variable.
1868 Enable the VGA video / BIOS for x86. The alternative if you
1869 are using coreboot is to use the coreboot frame buffer
1876 Define this to enable a custom keyboard support.
1877 This simply calls drv_keyboard_init() which must be
1878 defined in your board-specific files.
1879 The only board using this so far is RBC823.
1881 - LCD Support: CONFIG_LCD
1883 Define this to enable LCD support (for output to LCD
1884 display); also select one of the supported displays
1885 by defining one of these:
1889 HITACHI TX09D70VM1CCA, 3.5", 240x320.
1891 CONFIG_NEC_NL6448AC33:
1893 NEC NL6448AC33-18. Active, color, single scan.
1895 CONFIG_NEC_NL6448BC20
1897 NEC NL6448BC20-08. 6.5", 640x480.
1898 Active, color, single scan.
1900 CONFIG_NEC_NL6448BC33_54
1902 NEC NL6448BC33-54. 10.4", 640x480.
1903 Active, color, single scan.
1907 Sharp 320x240. Active, color, single scan.
1908 It isn't 16x9, and I am not sure what it is.
1910 CONFIG_SHARP_LQ64D341
1912 Sharp LQ64D341 display, 640x480.
1913 Active, color, single scan.
1917 HLD1045 display, 640x480.
1918 Active, color, single scan.
1922 Optrex CBL50840-2 NF-FW 99 22 M5
1924 Hitachi LMG6912RPFC-00T
1928 320x240. Black & white.
1930 Normally display is black on white background; define
1931 CONFIG_SYS_WHITE_ON_BLACK to get it inverted.
1933 CONFIG_LCD_ALIGNMENT
1935 Normally the LCD is page-aligned (typically 4KB). If this is
1936 defined then the LCD will be aligned to this value instead.
1937 For ARM it is sometimes useful to use MMU_SECTION_SIZE
1938 here, since it is cheaper to change data cache settings on
1939 a per-section basis.
1941 CONFIG_CONSOLE_SCROLL_LINES
1943 When the console need to be scrolled, this is the number of
1944 lines to scroll by. It defaults to 1. Increasing this makes
1945 the console jump but can help speed up operation when scrolling
1950 Support drawing of RLE8-compressed bitmaps on the LCD.
1954 Enables an 'i2c edid' command which can read EDID
1955 information over I2C from an attached LCD display.
1957 - Splash Screen Support: CONFIG_SPLASH_SCREEN
1959 If this option is set, the environment is checked for
1960 a variable "splashimage". If found, the usual display
1961 of logo, copyright and system information on the LCD
1962 is suppressed and the BMP image at the address
1963 specified in "splashimage" is loaded instead. The
1964 console is redirected to the "nulldev", too. This
1965 allows for a "silent" boot where a splash screen is
1966 loaded very quickly after power-on.
1968 CONFIG_SPLASHIMAGE_GUARD
1970 If this option is set, then U-Boot will prevent the environment
1971 variable "splashimage" from being set to a problematic address
1972 (see README.displaying-bmps).
1973 This option is useful for targets where, due to alignment
1974 restrictions, an improperly aligned BMP image will cause a data
1975 abort. If you think you will not have problems with unaligned
1976 accesses (for example because your toolchain prevents them)
1977 there is no need to set this option.
1979 CONFIG_SPLASH_SCREEN_ALIGN
1981 If this option is set the splash image can be freely positioned
1982 on the screen. Environment variable "splashpos" specifies the
1983 position as "x,y". If a positive number is given it is used as
1984 number of pixel from left/top. If a negative number is given it
1985 is used as number of pixel from right/bottom. You can also
1986 specify 'm' for centering the image.
1989 setenv splashpos m,m
1990 => image at center of screen
1992 setenv splashpos 30,20
1993 => image at x = 30 and y = 20
1995 setenv splashpos -10,m
1996 => vertically centered image
1997 at x = dspWidth - bmpWidth - 9
1999 - Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP
2001 If this option is set, additionally to standard BMP
2002 images, gzipped BMP images can be displayed via the
2003 splashscreen support or the bmp command.
2005 - Run length encoded BMP image (RLE8) support: CONFIG_VIDEO_BMP_RLE8
2007 If this option is set, 8-bit RLE compressed BMP images
2008 can be displayed via the splashscreen support or the
2011 - Do compressing for memory range:
2014 If this option is set, it would use zlib deflate method
2015 to compress the specified memory at its best effort.
2017 - Compression support:
2020 Enabled by default to support gzip compressed images.
2024 If this option is set, support for bzip2 compressed
2025 images is included. If not, only uncompressed and gzip
2026 compressed images are supported.
2028 NOTE: the bzip2 algorithm requires a lot of RAM, so
2029 the malloc area (as defined by CONFIG_SYS_MALLOC_LEN) should
2034 If this option is set, support for lzma compressed
2037 Note: The LZMA algorithm adds between 2 and 4KB of code and it
2038 requires an amount of dynamic memory that is given by the
2041 (1846 + 768 << (lc + lp)) * sizeof(uint16)
2043 Where lc and lp stand for, respectively, Literal context bits
2044 and Literal pos bits.
2046 This value is upper-bounded by 14MB in the worst case. Anyway,
2047 for a ~4MB large kernel image, we have lc=3 and lp=0 for a
2048 total amount of (1846 + 768 << (3 + 0)) * 2 = ~41KB... that is
2049 a very small buffer.
2051 Use the lzmainfo tool to determinate the lc and lp values and
2052 then calculate the amount of needed dynamic memory (ensuring
2053 the appropriate CONFIG_SYS_MALLOC_LEN value).
2057 If this option is set, support for LZO compressed images
2063 The address of PHY on MII bus.
2065 CONFIG_PHY_CLOCK_FREQ (ppc4xx)
2067 The clock frequency of the MII bus
2071 If this option is set, support for speed/duplex
2072 detection of gigabit PHY is included.
2074 CONFIG_PHY_RESET_DELAY
2076 Some PHY like Intel LXT971A need extra delay after
2077 reset before any MII register access is possible.
2078 For such PHY, set this option to the usec delay
2079 required. (minimum 300usec for LXT971A)
2081 CONFIG_PHY_CMD_DELAY (ppc4xx)
2083 Some PHY like Intel LXT971A need extra delay after
2084 command issued before MII status register can be read
2094 Define a default value for Ethernet address to use
2095 for the respective Ethernet interface, in case this
2096 is not determined automatically.
2101 Define a default value for the IP address to use for
2102 the default Ethernet interface, in case this is not
2103 determined through e.g. bootp.
2104 (Environment variable "ipaddr")
2106 - Server IP address:
2109 Defines a default value for the IP address of a TFTP
2110 server to contact when using the "tftboot" command.
2111 (Environment variable "serverip")
2113 CONFIG_KEEP_SERVERADDR
2115 Keeps the server's MAC address, in the env 'serveraddr'
2116 for passing to bootargs (like Linux's netconsole option)
2118 - Gateway IP address:
2121 Defines a default value for the IP address of the
2122 default router where packets to other networks are
2124 (Environment variable "gatewayip")
2129 Defines a default value for the subnet mask (or
2130 routing prefix) which is used to determine if an IP
2131 address belongs to the local subnet or needs to be
2132 forwarded through a router.
2133 (Environment variable "netmask")
2135 - Multicast TFTP Mode:
2138 Defines whether you want to support multicast TFTP as per
2139 rfc-2090; for example to work with atftp. Lets lots of targets
2140 tftp down the same boot image concurrently. Note: the Ethernet
2141 driver in use must provide a function: mcast() to join/leave a
2144 - BOOTP Recovery Mode:
2145 CONFIG_BOOTP_RANDOM_DELAY
2147 If you have many targets in a network that try to
2148 boot using BOOTP, you may want to avoid that all
2149 systems send out BOOTP requests at precisely the same
2150 moment (which would happen for instance at recovery
2151 from a power failure, when all systems will try to
2152 boot, thus flooding the BOOTP server. Defining
2153 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
2154 inserted before sending out BOOTP requests. The
2155 following delays are inserted then:
2157 1st BOOTP request: delay 0 ... 1 sec
2158 2nd BOOTP request: delay 0 ... 2 sec
2159 3rd BOOTP request: delay 0 ... 4 sec
2161 BOOTP requests: delay 0 ... 8 sec
2163 CONFIG_BOOTP_ID_CACHE_SIZE
2165 BOOTP packets are uniquely identified using a 32-bit ID. The
2166 server will copy the ID from client requests to responses and
2167 U-Boot will use this to determine if it is the destination of
2168 an incoming response. Some servers will check that addresses
2169 aren't in use before handing them out (usually using an ARP
2170 ping) and therefore take up to a few hundred milliseconds to
2171 respond. Network congestion may also influence the time it
2172 takes for a response to make it back to the client. If that
2173 time is too long, U-Boot will retransmit requests. In order
2174 to allow earlier responses to still be accepted after these
2175 retransmissions, U-Boot's BOOTP client keeps a small cache of
2176 IDs. The CONFIG_BOOTP_ID_CACHE_SIZE controls the size of this
2177 cache. The default is to keep IDs for up to four outstanding
2178 requests. Increasing this will allow U-Boot to accept offers
2179 from a BOOTP client in networks with unusually high latency.
2181 - BOOTP Random transaction ID:
2182 CONFIG_BOOTP_RANDOM_ID
2184 The standard algorithm to generate a DHCP/BOOTP transaction ID
2185 by using the MAC address and the current time stamp may not
2186 quite unlikely produce duplicate transaction IDs from different
2187 clients in the same network. This option creates a transaction
2188 ID using the rand() function. Provided that the RNG has been
2189 seeded well, this should guarantee unique transaction IDs
2192 - DHCP Advanced Options:
2193 You can fine tune the DHCP functionality by defining
2194 CONFIG_BOOTP_* symbols:
2196 CONFIG_BOOTP_SUBNETMASK
2197 CONFIG_BOOTP_GATEWAY
2198 CONFIG_BOOTP_HOSTNAME
2199 CONFIG_BOOTP_NISDOMAIN
2200 CONFIG_BOOTP_BOOTPATH
2201 CONFIG_BOOTP_BOOTFILESIZE
2204 CONFIG_BOOTP_SEND_HOSTNAME
2205 CONFIG_BOOTP_NTPSERVER
2206 CONFIG_BOOTP_TIMEOFFSET
2207 CONFIG_BOOTP_VENDOREX
2208 CONFIG_BOOTP_MAY_FAIL
2210 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip
2211 environment variable, not the BOOTP server.
2213 CONFIG_BOOTP_MAY_FAIL - If the DHCP server is not found
2214 after the configured retry count, the call will fail
2215 instead of starting over. This can be used to fail over
2216 to Link-local IP address configuration if the DHCP server
2219 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS
2220 serverip from a DHCP server, it is possible that more
2221 than one DNS serverip is offered to the client.
2222 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS
2223 serverip will be stored in the additional environment
2224 variable "dnsip2". The first DNS serverip is always
2225 stored in the variable "dnsip", when CONFIG_BOOTP_DNS
2228 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable
2229 to do a dynamic update of a DNS server. To do this, they
2230 need the hostname of the DHCP requester.
2231 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content
2232 of the "hostname" environment variable is passed as
2233 option 12 to the DHCP server.
2235 CONFIG_BOOTP_DHCP_REQUEST_DELAY
2237 A 32bit value in microseconds for a delay between
2238 receiving a "DHCP Offer" and sending the "DHCP Request".
2239 This fixes a problem with certain DHCP servers that don't
2240 respond 100% of the time to a "DHCP request". E.g. On an
2241 AT91RM9200 processor running at 180MHz, this delay needed
2242 to be *at least* 15,000 usec before a Windows Server 2003
2243 DHCP server would reply 100% of the time. I recommend at
2244 least 50,000 usec to be safe. The alternative is to hope
2245 that one of the retries will be successful but note that
2246 the DHCP timeout and retry process takes a longer than
2249 - Link-local IP address negotiation:
2250 Negotiate with other link-local clients on the local network
2251 for an address that doesn't require explicit configuration.
2252 This is especially useful if a DHCP server cannot be guaranteed
2253 to exist in all environments that the device must operate.
2255 See doc/README.link-local for more information.
2258 CONFIG_CDP_DEVICE_ID
2260 The device id used in CDP trigger frames.
2262 CONFIG_CDP_DEVICE_ID_PREFIX
2264 A two character string which is prefixed to the MAC address
2269 A printf format string which contains the ascii name of
2270 the port. Normally is set to "eth%d" which sets
2271 eth0 for the first Ethernet, eth1 for the second etc.
2273 CONFIG_CDP_CAPABILITIES
2275 A 32bit integer which indicates the device capabilities;
2276 0x00000010 for a normal host which does not forwards.
2280 An ascii string containing the version of the software.
2284 An ascii string containing the name of the platform.
2288 A 32bit integer sent on the trigger.
2290 CONFIG_CDP_POWER_CONSUMPTION
2292 A 16bit integer containing the power consumption of the
2293 device in .1 of milliwatts.
2295 CONFIG_CDP_APPLIANCE_VLAN_TYPE
2297 A byte containing the id of the VLAN.
2299 - Status LED: CONFIG_STATUS_LED
2301 Several configurations allow to display the current
2302 status using a LED. For instance, the LED will blink
2303 fast while running U-Boot code, stop blinking as
2304 soon as a reply to a BOOTP request was received, and
2305 start blinking slow once the Linux kernel is running
2306 (supported by a status LED driver in the Linux
2307 kernel). Defining CONFIG_STATUS_LED enables this
2313 The status LED can be connected to a GPIO pin.
2314 In such cases, the gpio_led driver can be used as a
2315 status LED backend implementation. Define CONFIG_GPIO_LED
2316 to include the gpio_led driver in the U-Boot binary.
2318 CONFIG_GPIO_LED_INVERTED_TABLE
2319 Some GPIO connected LEDs may have inverted polarity in which
2320 case the GPIO high value corresponds to LED off state and
2321 GPIO low value corresponds to LED on state.
2322 In such cases CONFIG_GPIO_LED_INVERTED_TABLE may be defined
2323 with a list of GPIO LEDs that have inverted polarity.
2325 - CAN Support: CONFIG_CAN_DRIVER
2327 Defining CONFIG_CAN_DRIVER enables CAN driver support
2328 on those systems that support this (optional)
2329 feature, like the TQM8xxL modules.
2331 - I2C Support: CONFIG_SYS_I2C
2333 This enable the NEW i2c subsystem, and will allow you to use
2334 i2c commands at the u-boot command line (as long as you set
2335 CONFIG_CMD_I2C in CONFIG_COMMANDS) and communicate with i2c
2336 based realtime clock chips or other i2c devices. See
2337 common/cmd_i2c.c for a description of the command line
2340 ported i2c driver to the new framework:
2341 - drivers/i2c/soft_i2c.c:
2342 - activate first bus with CONFIG_SYS_I2C_SOFT define
2343 CONFIG_SYS_I2C_SOFT_SPEED and CONFIG_SYS_I2C_SOFT_SLAVE
2344 for defining speed and slave address
2345 - activate second bus with I2C_SOFT_DECLARATIONS2 define
2346 CONFIG_SYS_I2C_SOFT_SPEED_2 and CONFIG_SYS_I2C_SOFT_SLAVE_2
2347 for defining speed and slave address
2348 - activate third bus with I2C_SOFT_DECLARATIONS3 define
2349 CONFIG_SYS_I2C_SOFT_SPEED_3 and CONFIG_SYS_I2C_SOFT_SLAVE_3
2350 for defining speed and slave address
2351 - activate fourth bus with I2C_SOFT_DECLARATIONS4 define
2352 CONFIG_SYS_I2C_SOFT_SPEED_4 and CONFIG_SYS_I2C_SOFT_SLAVE_4
2353 for defining speed and slave address
2355 - drivers/i2c/fsl_i2c.c:
2356 - activate i2c driver with CONFIG_SYS_I2C_FSL
2357 define CONFIG_SYS_FSL_I2C_OFFSET for setting the register
2358 offset CONFIG_SYS_FSL_I2C_SPEED for the i2c speed and
2359 CONFIG_SYS_FSL_I2C_SLAVE for the slave addr of the first
2361 - If your board supports a second fsl i2c bus, define
2362 CONFIG_SYS_FSL_I2C2_OFFSET for the register offset
2363 CONFIG_SYS_FSL_I2C2_SPEED for the speed and
2364 CONFIG_SYS_FSL_I2C2_SLAVE for the slave address of the
2367 - drivers/i2c/tegra_i2c.c:
2368 - activate this driver with CONFIG_SYS_I2C_TEGRA
2369 - This driver adds 4 i2c buses with a fix speed from
2370 100000 and the slave addr 0!
2372 - drivers/i2c/ppc4xx_i2c.c
2373 - activate this driver with CONFIG_SYS_I2C_PPC4XX
2374 - CONFIG_SYS_I2C_PPC4XX_CH0 activate hardware channel 0
2375 - CONFIG_SYS_I2C_PPC4XX_CH1 activate hardware channel 1
2377 - drivers/i2c/i2c_mxc.c
2378 - activate this driver with CONFIG_SYS_I2C_MXC
2379 - define speed for bus 1 with CONFIG_SYS_MXC_I2C1_SPEED
2380 - define slave for bus 1 with CONFIG_SYS_MXC_I2C1_SLAVE
2381 - define speed for bus 2 with CONFIG_SYS_MXC_I2C2_SPEED
2382 - define slave for bus 2 with CONFIG_SYS_MXC_I2C2_SLAVE
2383 - define speed for bus 3 with CONFIG_SYS_MXC_I2C3_SPEED
2384 - define slave for bus 3 with CONFIG_SYS_MXC_I2C3_SLAVE
2385 If those defines are not set, default value is 100000
2386 for speed, and 0 for slave.
2388 - drivers/i2c/rcar_i2c.c:
2389 - activate this driver with CONFIG_SYS_I2C_RCAR
2390 - This driver adds 4 i2c buses
2392 - CONFIG_SYS_RCAR_I2C0_BASE for setting the register channel 0
2393 - CONFIG_SYS_RCAR_I2C0_SPEED for for the speed channel 0
2394 - CONFIG_SYS_RCAR_I2C1_BASE for setting the register channel 1
2395 - CONFIG_SYS_RCAR_I2C1_SPEED for for the speed channel 1
2396 - CONFIG_SYS_RCAR_I2C2_BASE for setting the register channel 2
2397 - CONFIG_SYS_RCAR_I2C2_SPEED for for the speed channel 2
2398 - CONFIG_SYS_RCAR_I2C3_BASE for setting the register channel 3
2399 - CONFIG_SYS_RCAR_I2C3_SPEED for for the speed channel 3
2400 - CONFIF_SYS_RCAR_I2C_NUM_CONTROLLERS for number of i2c buses
2402 - drivers/i2c/sh_i2c.c:
2403 - activate this driver with CONFIG_SYS_I2C_SH
2404 - This driver adds from 2 to 5 i2c buses
2406 - CONFIG_SYS_I2C_SH_BASE0 for setting the register channel 0
2407 - CONFIG_SYS_I2C_SH_SPEED0 for for the speed channel 0
2408 - CONFIG_SYS_I2C_SH_BASE1 for setting the register channel 1
2409 - CONFIG_SYS_I2C_SH_SPEED1 for for the speed channel 1
2410 - CONFIG_SYS_I2C_SH_BASE2 for setting the register channel 2
2411 - CONFIG_SYS_I2C_SH_SPEED2 for for the speed channel 2
2412 - CONFIG_SYS_I2C_SH_BASE3 for setting the register channel 3
2413 - CONFIG_SYS_I2C_SH_SPEED3 for for the speed channel 3
2414 - CONFIG_SYS_I2C_SH_BASE4 for setting the register channel 4
2415 - CONFIG_SYS_I2C_SH_SPEED4 for for the speed channel 4
2416 - CONFIG_SYS_I2C_SH_BASE5 for setting the register channel 5
2417 - CONFIG_SYS_I2C_SH_SPEED5 for for the speed channel 5
2418 - CONFIG_SYS_I2C_SH_NUM_CONTROLLERS for number of i2c buses
2420 - drivers/i2c/omap24xx_i2c.c
2421 - activate this driver with CONFIG_SYS_I2C_OMAP24XX
2422 - CONFIG_SYS_OMAP24_I2C_SPEED speed channel 0
2423 - CONFIG_SYS_OMAP24_I2C_SLAVE slave addr channel 0
2424 - CONFIG_SYS_OMAP24_I2C_SPEED1 speed channel 1
2425 - CONFIG_SYS_OMAP24_I2C_SLAVE1 slave addr channel 1
2426 - CONFIG_SYS_OMAP24_I2C_SPEED2 speed channel 2
2427 - CONFIG_SYS_OMAP24_I2C_SLAVE2 slave addr channel 2
2428 - CONFIG_SYS_OMAP24_I2C_SPEED3 speed channel 3
2429 - CONFIG_SYS_OMAP24_I2C_SLAVE3 slave addr channel 3
2430 - CONFIG_SYS_OMAP24_I2C_SPEED4 speed channel 4
2431 - CONFIG_SYS_OMAP24_I2C_SLAVE4 slave addr channel 4
2433 - drivers/i2c/zynq_i2c.c
2434 - activate this driver with CONFIG_SYS_I2C_ZYNQ
2435 - set CONFIG_SYS_I2C_ZYNQ_SPEED for speed setting
2436 - set CONFIG_SYS_I2C_ZYNQ_SLAVE for slave addr
2438 - drivers/i2c/s3c24x0_i2c.c:
2439 - activate this driver with CONFIG_SYS_I2C_S3C24X0
2440 - This driver adds i2c buses (11 for Exynos5250, Exynos5420
2441 9 i2c buses for Exynos4 and 1 for S3C24X0 SoCs from Samsung)
2442 with a fix speed from 100000 and the slave addr 0!
2444 - drivers/i2c/ihs_i2c.c
2445 - activate this driver with CONFIG_SYS_I2C_IHS
2446 - CONFIG_SYS_I2C_IHS_CH0 activate hardware channel 0
2447 - CONFIG_SYS_I2C_IHS_SPEED_0 speed channel 0
2448 - CONFIG_SYS_I2C_IHS_SLAVE_0 slave addr channel 0
2449 - CONFIG_SYS_I2C_IHS_CH1 activate hardware channel 1
2450 - CONFIG_SYS_I2C_IHS_SPEED_1 speed channel 1
2451 - CONFIG_SYS_I2C_IHS_SLAVE_1 slave addr channel 1
2452 - CONFIG_SYS_I2C_IHS_CH2 activate hardware channel 2
2453 - CONFIG_SYS_I2C_IHS_SPEED_2 speed channel 2
2454 - CONFIG_SYS_I2C_IHS_SLAVE_2 slave addr channel 2
2455 - CONFIG_SYS_I2C_IHS_CH3 activate hardware channel 3
2456 - CONFIG_SYS_I2C_IHS_SPEED_3 speed channel 3
2457 - CONFIG_SYS_I2C_IHS_SLAVE_3 slave addr channel 3
2461 CONFIG_SYS_NUM_I2C_BUSES
2462 Hold the number of i2c buses you want to use. If you
2463 don't use/have i2c muxes on your i2c bus, this
2464 is equal to CONFIG_SYS_NUM_I2C_ADAPTERS, and you can
2467 CONFIG_SYS_I2C_DIRECT_BUS
2468 define this, if you don't use i2c muxes on your hardware.
2469 if CONFIG_SYS_I2C_MAX_HOPS is not defined or == 0 you can
2472 CONFIG_SYS_I2C_MAX_HOPS
2473 define how many muxes are maximal consecutively connected
2474 on one i2c bus. If you not use i2c muxes, omit this
2477 CONFIG_SYS_I2C_BUSES
2478 hold a list of buses you want to use, only used if
2479 CONFIG_SYS_I2C_DIRECT_BUS is not defined, for example
2480 a board with CONFIG_SYS_I2C_MAX_HOPS = 1 and
2481 CONFIG_SYS_NUM_I2C_BUSES = 9:
2483 CONFIG_SYS_I2C_BUSES {{0, {I2C_NULL_HOP}}, \
2484 {0, {{I2C_MUX_PCA9547, 0x70, 1}}}, \
2485 {0, {{I2C_MUX_PCA9547, 0x70, 2}}}, \
2486 {0, {{I2C_MUX_PCA9547, 0x70, 3}}}, \
2487 {0, {{I2C_MUX_PCA9547, 0x70, 4}}}, \
2488 {0, {{I2C_MUX_PCA9547, 0x70, 5}}}, \
2489 {1, {I2C_NULL_HOP}}, \
2490 {1, {{I2C_MUX_PCA9544, 0x72, 1}}}, \
2491 {1, {{I2C_MUX_PCA9544, 0x72, 2}}}, \
2495 bus 0 on adapter 0 without a mux
2496 bus 1 on adapter 0 with a PCA9547 on address 0x70 port 1
2497 bus 2 on adapter 0 with a PCA9547 on address 0x70 port 2
2498 bus 3 on adapter 0 with a PCA9547 on address 0x70 port 3
2499 bus 4 on adapter 0 with a PCA9547 on address 0x70 port 4
2500 bus 5 on adapter 0 with a PCA9547 on address 0x70 port 5
2501 bus 6 on adapter 1 without a mux
2502 bus 7 on adapter 1 with a PCA9544 on address 0x72 port 1
2503 bus 8 on adapter 1 with a PCA9544 on address 0x72 port 2
2505 If you do not have i2c muxes on your board, omit this define.
2507 - Legacy I2C Support: CONFIG_HARD_I2C
2509 NOTE: It is intended to move drivers to CONFIG_SYS_I2C which
2510 provides the following compelling advantages:
2512 - more than one i2c adapter is usable
2513 - approved multibus support
2514 - better i2c mux support
2516 ** Please consider updating your I2C driver now. **
2518 These enable legacy I2C serial bus commands. Defining
2519 CONFIG_HARD_I2C will include the appropriate I2C driver
2520 for the selected CPU.
2522 This will allow you to use i2c commands at the u-boot
2523 command line (as long as you set CONFIG_CMD_I2C in
2524 CONFIG_COMMANDS) and communicate with i2c based realtime
2525 clock chips. See common/cmd_i2c.c for a description of the
2526 command line interface.
2528 CONFIG_HARD_I2C selects a hardware I2C controller.
2530 There are several other quantities that must also be
2531 defined when you define CONFIG_HARD_I2C.
2533 In both cases you will need to define CONFIG_SYS_I2C_SPEED
2534 to be the frequency (in Hz) at which you wish your i2c bus
2535 to run and CONFIG_SYS_I2C_SLAVE to be the address of this node (ie
2536 the CPU's i2c node address).
2538 Now, the u-boot i2c code for the mpc8xx
2539 (arch/powerpc/cpu/mpc8xx/i2c.c) sets the CPU up as a master node
2540 and so its address should therefore be cleared to 0 (See,
2541 eg, MPC823e User's Manual p.16-473). So, set
2542 CONFIG_SYS_I2C_SLAVE to 0.
2544 CONFIG_SYS_I2C_INIT_MPC5XXX
2546 When a board is reset during an i2c bus transfer
2547 chips might think that the current transfer is still
2548 in progress. Reset the slave devices by sending start
2549 commands until the slave device responds.
2551 That's all that's required for CONFIG_HARD_I2C.
2553 If you use the software i2c interface (CONFIG_SYS_I2C_SOFT)
2554 then the following macros need to be defined (examples are
2555 from include/configs/lwmon.h):
2559 (Optional). Any commands necessary to enable the I2C
2560 controller or configure ports.
2562 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
2566 (Only for MPC8260 CPU). The I/O port to use (the code
2567 assumes both bits are on the same port). Valid values
2568 are 0..3 for ports A..D.
2572 The code necessary to make the I2C data line active
2573 (driven). If the data line is open collector, this
2576 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
2580 The code necessary to make the I2C data line tri-stated
2581 (inactive). If the data line is open collector, this
2584 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
2588 Code that returns true if the I2C data line is high,
2591 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
2595 If <bit> is true, sets the I2C data line high. If it
2596 is false, it clears it (low).
2598 eg: #define I2C_SDA(bit) \
2599 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
2600 else immr->im_cpm.cp_pbdat &= ~PB_SDA
2604 If <bit> is true, sets the I2C clock line high. If it
2605 is false, it clears it (low).
2607 eg: #define I2C_SCL(bit) \
2608 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
2609 else immr->im_cpm.cp_pbdat &= ~PB_SCL
2613 This delay is invoked four times per clock cycle so this
2614 controls the rate of data transfer. The data rate thus
2615 is 1 / (I2C_DELAY * 4). Often defined to be something
2618 #define I2C_DELAY udelay(2)
2620 CONFIG_SOFT_I2C_GPIO_SCL / CONFIG_SOFT_I2C_GPIO_SDA
2622 If your arch supports the generic GPIO framework (asm/gpio.h),
2623 then you may alternatively define the two GPIOs that are to be
2624 used as SCL / SDA. Any of the previous I2C_xxx macros will
2625 have GPIO-based defaults assigned to them as appropriate.
2627 You should define these to the GPIO value as given directly to
2628 the generic GPIO functions.
2630 CONFIG_SYS_I2C_INIT_BOARD
2632 When a board is reset during an i2c bus transfer
2633 chips might think that the current transfer is still
2634 in progress. On some boards it is possible to access
2635 the i2c SCLK line directly, either by using the
2636 processor pin as a GPIO or by having a second pin
2637 connected to the bus. If this option is defined a
2638 custom i2c_init_board() routine in boards/xxx/board.c
2639 is run early in the boot sequence.
2641 CONFIG_SYS_I2C_BOARD_LATE_INIT
2643 An alternative to CONFIG_SYS_I2C_INIT_BOARD. If this option is
2644 defined a custom i2c_board_late_init() routine in
2645 boards/xxx/board.c is run AFTER the operations in i2c_init()
2646 is completed. This callpoint can be used to unreset i2c bus
2647 using CPU i2c controller register accesses for CPUs whose i2c
2648 controller provide such a method. It is called at the end of
2649 i2c_init() to allow i2c_init operations to setup the i2c bus
2650 controller on the CPU (e.g. setting bus speed & slave address).
2652 CONFIG_I2CFAST (PPC405GP|PPC405EP only)
2654 This option enables configuration of bi_iic_fast[] flags
2655 in u-boot bd_info structure based on u-boot environment
2656 variable "i2cfast". (see also i2cfast)
2658 CONFIG_I2C_MULTI_BUS
2660 This option allows the use of multiple I2C buses, each of which
2661 must have a controller. At any point in time, only one bus is
2662 active. To switch to a different bus, use the 'i2c dev' command.
2663 Note that bus numbering is zero-based.
2665 CONFIG_SYS_I2C_NOPROBES
2667 This option specifies a list of I2C devices that will be skipped
2668 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS
2669 is set, specify a list of bus-device pairs. Otherwise, specify
2670 a 1D array of device addresses
2673 #undef CONFIG_I2C_MULTI_BUS
2674 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68}
2676 will skip addresses 0x50 and 0x68 on a board with one I2C bus
2678 #define CONFIG_I2C_MULTI_BUS
2679 #define CONFIG_SYS_I2C_MULTI_NOPROBES {{0,0x50},{0,0x68},{1,0x54}}
2681 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1
2683 CONFIG_SYS_SPD_BUS_NUM
2685 If defined, then this indicates the I2C bus number for DDR SPD.
2686 If not defined, then U-Boot assumes that SPD is on I2C bus 0.
2688 CONFIG_SYS_RTC_BUS_NUM
2690 If defined, then this indicates the I2C bus number for the RTC.
2691 If not defined, then U-Boot assumes that RTC is on I2C bus 0.
2693 CONFIG_SYS_DTT_BUS_NUM
2695 If defined, then this indicates the I2C bus number for the DTT.
2696 If not defined, then U-Boot assumes that DTT is on I2C bus 0.
2698 CONFIG_SYS_I2C_DTT_ADDR:
2700 If defined, specifies the I2C address of the DTT device.
2701 If not defined, then U-Boot uses predefined value for
2702 specified DTT device.
2704 CONFIG_SOFT_I2C_READ_REPEATED_START
2706 defining this will force the i2c_read() function in
2707 the soft_i2c driver to perform an I2C repeated start
2708 between writing the address pointer and reading the
2709 data. If this define is omitted the default behaviour
2710 of doing a stop-start sequence will be used. Most I2C
2711 devices can use either method, but some require one or
2714 - SPI Support: CONFIG_SPI
2716 Enables SPI driver (so far only tested with
2717 SPI EEPROM, also an instance works with Crystal A/D and
2718 D/As on the SACSng board)
2722 Enables the driver for SPI controller on SuperH. Currently
2723 only SH7757 is supported.
2727 Enables extended (16-bit) SPI EEPROM addressing.
2728 (symmetrical to CONFIG_I2C_X)
2732 Enables a software (bit-bang) SPI driver rather than
2733 using hardware support. This is a general purpose
2734 driver that only requires three general I/O port pins
2735 (two outputs, one input) to function. If this is
2736 defined, the board configuration must define several
2737 SPI configuration items (port pins to use, etc). For
2738 an example, see include/configs/sacsng.h.
2742 Enables a hardware SPI driver for general-purpose reads
2743 and writes. As with CONFIG_SOFT_SPI, the board configuration
2744 must define a list of chip-select function pointers.
2745 Currently supported on some MPC8xxx processors. For an
2746 example, see include/configs/mpc8349emds.h.
2750 Enables the driver for the SPI controllers on i.MX and MXC
2751 SoCs. Currently i.MX31/35/51 are supported.
2753 CONFIG_SYS_SPI_MXC_WAIT
2754 Timeout for waiting until spi transfer completed.
2755 default: (CONFIG_SYS_HZ/100) /* 10 ms */
2757 - FPGA Support: CONFIG_FPGA
2759 Enables FPGA subsystem.
2761 CONFIG_FPGA_<vendor>
2763 Enables support for specific chip vendors.
2766 CONFIG_FPGA_<family>
2768 Enables support for FPGA family.
2769 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX)
2773 Specify the number of FPGA devices to support.
2775 CONFIG_CMD_FPGA_LOADMK
2777 Enable support for fpga loadmk command
2779 CONFIG_CMD_FPGA_LOADP
2781 Enable support for fpga loadp command - load partial bitstream
2783 CONFIG_CMD_FPGA_LOADBP
2785 Enable support for fpga loadbp command - load partial bitstream
2788 CONFIG_SYS_FPGA_PROG_FEEDBACK
2790 Enable printing of hash marks during FPGA configuration.
2792 CONFIG_SYS_FPGA_CHECK_BUSY
2794 Enable checks on FPGA configuration interface busy
2795 status by the configuration function. This option
2796 will require a board or device specific function to
2801 If defined, a function that provides delays in the FPGA
2802 configuration driver.
2804 CONFIG_SYS_FPGA_CHECK_CTRLC
2805 Allow Control-C to interrupt FPGA configuration
2807 CONFIG_SYS_FPGA_CHECK_ERROR
2809 Check for configuration errors during FPGA bitfile
2810 loading. For example, abort during Virtex II
2811 configuration if the INIT_B line goes low (which
2812 indicated a CRC error).
2814 CONFIG_SYS_FPGA_WAIT_INIT
2816 Maximum time to wait for the INIT_B line to de-assert
2817 after PROB_B has been de-asserted during a Virtex II
2818 FPGA configuration sequence. The default time is 500
2821 CONFIG_SYS_FPGA_WAIT_BUSY
2823 Maximum time to wait for BUSY to de-assert during
2824 Virtex II FPGA configuration. The default is 5 ms.
2826 CONFIG_SYS_FPGA_WAIT_CONFIG
2828 Time to wait after FPGA configuration. The default is
2831 - Configuration Management:
2834 Some SoCs need special image types (e.g. U-Boot binary
2835 with a special header) as build targets. By defining
2836 CONFIG_BUILD_TARGET in the SoC / board header, this
2837 special image will be automatically built upon calling
2842 If defined, this string will be added to the U-Boot
2843 version information (U_BOOT_VERSION)
2845 - Vendor Parameter Protection:
2847 U-Boot considers the values of the environment
2848 variables "serial#" (Board Serial Number) and
2849 "ethaddr" (Ethernet Address) to be parameters that
2850 are set once by the board vendor / manufacturer, and
2851 protects these variables from casual modification by
2852 the user. Once set, these variables are read-only,
2853 and write or delete attempts are rejected. You can
2854 change this behaviour:
2856 If CONFIG_ENV_OVERWRITE is #defined in your config
2857 file, the write protection for vendor parameters is
2858 completely disabled. Anybody can change or delete
2861 Alternatively, if you #define _both_ CONFIG_ETHADDR
2862 _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
2863 Ethernet address is installed in the environment,
2864 which can be changed exactly ONCE by the user. [The
2865 serial# is unaffected by this, i. e. it remains
2868 The same can be accomplished in a more flexible way
2869 for any variable by configuring the type of access
2870 to allow for those variables in the ".flags" variable
2871 or define CONFIG_ENV_FLAGS_LIST_STATIC.
2876 Define this variable to enable the reservation of
2877 "protected RAM", i. e. RAM which is not overwritten
2878 by U-Boot. Define CONFIG_PRAM to hold the number of
2879 kB you want to reserve for pRAM. You can overwrite
2880 this default value by defining an environment
2881 variable "pram" to the number of kB you want to
2882 reserve. Note that the board info structure will
2883 still show the full amount of RAM. If pRAM is
2884 reserved, a new environment variable "mem" will
2885 automatically be defined to hold the amount of
2886 remaining RAM in a form that can be passed as boot
2887 argument to Linux, for instance like that:
2889 setenv bootargs ... mem=\${mem}
2892 This way you can tell Linux not to use this memory,
2893 either, which results in a memory region that will
2894 not be affected by reboots.
2896 *WARNING* If your board configuration uses automatic
2897 detection of the RAM size, you must make sure that
2898 this memory test is non-destructive. So far, the
2899 following board configurations are known to be
2902 IVMS8, IVML24, SPD8xx, TQM8xxL,
2903 HERMES, IP860, RPXlite, LWMON,
2906 - Access to physical memory region (> 4GB)
2907 Some basic support is provided for operations on memory not
2908 normally accessible to U-Boot - e.g. some architectures
2909 support access to more than 4GB of memory on 32-bit
2910 machines using physical address extension or similar.
2911 Define CONFIG_PHYSMEM to access this basic support, which
2912 currently only supports clearing the memory.
2917 Define this variable to stop the system in case of a
2918 fatal error, so that you have to reset it manually.
2919 This is probably NOT a good idea for an embedded
2920 system where you want the system to reboot
2921 automatically as fast as possible, but it may be
2922 useful during development since you can try to debug
2923 the conditions that lead to the situation.
2925 CONFIG_NET_RETRY_COUNT
2927 This variable defines the number of retries for
2928 network operations like ARP, RARP, TFTP, or BOOTP
2929 before giving up the operation. If not defined, a
2930 default value of 5 is used.
2934 Timeout waiting for an ARP reply in milliseconds.
2938 Timeout in milliseconds used in NFS protocol.
2939 If you encounter "ERROR: Cannot umount" in nfs command,
2940 try longer timeout such as
2941 #define CONFIG_NFS_TIMEOUT 10000UL
2943 - Command Interpreter:
2944 CONFIG_AUTO_COMPLETE
2946 Enable auto completion of commands using TAB.
2948 CONFIG_SYS_PROMPT_HUSH_PS2
2950 This defines the secondary prompt string, which is
2951 printed when the command interpreter needs more input
2952 to complete a command. Usually "> ".
2956 In the current implementation, the local variables
2957 space and global environment variables space are
2958 separated. Local variables are those you define by
2959 simply typing `name=value'. To access a local
2960 variable later on, you have write `$name' or
2961 `${name}'; to execute the contents of a variable
2962 directly type `$name' at the command prompt.
2964 Global environment variables are those you use
2965 setenv/printenv to work with. To run a command stored
2966 in such a variable, you need to use the run command,
2967 and you must not use the '$' sign to access them.
2969 To store commands and special characters in a
2970 variable, please use double quotation marks
2971 surrounding the whole text of the variable, instead
2972 of the backslashes before semicolons and special
2975 - Command Line Editing and History:
2976 CONFIG_CMDLINE_EDITING
2978 Enable editing and History functions for interactive
2979 command line input operations
2981 - Default Environment:
2982 CONFIG_EXTRA_ENV_SETTINGS
2984 Define this to contain any number of null terminated
2985 strings (variable = value pairs) that will be part of
2986 the default environment compiled into the boot image.
2988 For example, place something like this in your
2989 board's config file:
2991 #define CONFIG_EXTRA_ENV_SETTINGS \
2995 Warning: This method is based on knowledge about the
2996 internal format how the environment is stored by the
2997 U-Boot code. This is NOT an official, exported
2998 interface! Although it is unlikely that this format
2999 will change soon, there is no guarantee either.
3000 You better know what you are doing here.
3002 Note: overly (ab)use of the default environment is
3003 discouraged. Make sure to check other ways to preset
3004 the environment like the "source" command or the
3007 CONFIG_ENV_VARS_UBOOT_CONFIG
3009 Define this in order to add variables describing the
3010 U-Boot build configuration to the default environment.
3011 These will be named arch, cpu, board, vendor, and soc.
3013 Enabling this option will cause the following to be defined:
3021 CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG
3023 Define this in order to add variables describing certain
3024 run-time determined information about the hardware to the
3025 environment. These will be named board_name, board_rev.
3027 CONFIG_DELAY_ENVIRONMENT
3029 Normally the environment is loaded when the board is
3030 initialised so that it is available to U-Boot. This inhibits
3031 that so that the environment is not available until
3032 explicitly loaded later by U-Boot code. With CONFIG_OF_CONTROL
3033 this is instead controlled by the value of
3034 /config/load-environment.
3036 - DataFlash Support:
3037 CONFIG_HAS_DATAFLASH
3039 Defining this option enables DataFlash features and
3040 allows to read/write in Dataflash via the standard
3043 - Serial Flash support
3046 Defining this option enables SPI flash commands
3047 'sf probe/read/write/erase/update'.
3049 Usage requires an initial 'probe' to define the serial
3050 flash parameters, followed by read/write/erase/update
3053 The following defaults may be provided by the platform
3054 to handle the common case when only a single serial
3055 flash is present on the system.
3057 CONFIG_SF_DEFAULT_BUS Bus identifier
3058 CONFIG_SF_DEFAULT_CS Chip-select
3059 CONFIG_SF_DEFAULT_MODE (see include/spi.h)
3060 CONFIG_SF_DEFAULT_SPEED in Hz
3064 Define this option to include a destructive SPI flash
3067 CONFIG_SPI_FLASH_BAR Ban/Extended Addr Reg
3069 Define this option to use the Bank addr/Extended addr
3070 support on SPI flashes which has size > 16Mbytes.
3072 CONFIG_SF_DUAL_FLASH Dual flash memories
3074 Define this option to use dual flash support where two flash
3075 memories can be connected with a given cs line.
3076 Currently Xilinx Zynq qspi supports these type of connections.
3078 CONFIG_SYS_SPI_ST_ENABLE_WP_PIN
3079 enable the W#/Vpp signal to disable writing to the status
3080 register on ST MICRON flashes like the N25Q128.
3081 The status register write enable/disable bit, combined with
3082 the W#/VPP signal provides hardware data protection for the
3083 device as follows: When the enable/disable bit is set to 1,
3084 and the W#/VPP signal is driven LOW, the status register
3085 nonvolatile bits become read-only and the WRITE STATUS REGISTER
3086 operation will not execute. The only way to exit this
3087 hardware-protected mode is to drive W#/VPP HIGH.
3089 - SystemACE Support:
3092 Adding this option adds support for Xilinx SystemACE
3093 chips attached via some sort of local bus. The address
3094 of the chip must also be defined in the
3095 CONFIG_SYS_SYSTEMACE_BASE macro. For example:
3097 #define CONFIG_SYSTEMACE
3098 #define CONFIG_SYS_SYSTEMACE_BASE 0xf0000000
3100 When SystemACE support is added, the "ace" device type
3101 becomes available to the fat commands, i.e. fatls.
3103 - TFTP Fixed UDP Port:
3106 If this is defined, the environment variable tftpsrcp
3107 is used to supply the TFTP UDP source port value.
3108 If tftpsrcp isn't defined, the normal pseudo-random port
3109 number generator is used.
3111 Also, the environment variable tftpdstp is used to supply
3112 the TFTP UDP destination port value. If tftpdstp isn't
3113 defined, the normal port 69 is used.
3115 The purpose for tftpsrcp is to allow a TFTP server to
3116 blindly start the TFTP transfer using the pre-configured
3117 target IP address and UDP port. This has the effect of
3118 "punching through" the (Windows XP) firewall, allowing
3119 the remainder of the TFTP transfer to proceed normally.
3120 A better solution is to properly configure the firewall,
3121 but sometimes that is not allowed.
3126 This enables a generic 'hash' command which can produce
3127 hashes / digests from a few algorithms (e.g. SHA1, SHA256).
3131 Enable the hash verify command (hash -v). This adds to code
3134 CONFIG_SHA1 - This option enables support of hashing using SHA1
3135 algorithm. The hash is calculated in software.
3136 CONFIG_SHA256 - This option enables support of hashing using
3137 SHA256 algorithm. The hash is calculated in software.
3138 CONFIG_SHA_HW_ACCEL - This option enables hardware acceleration
3139 for SHA1/SHA256 hashing.
3140 This affects the 'hash' command and also the
3141 hash_lookup_algo() function.
3142 CONFIG_SHA_PROG_HW_ACCEL - This option enables
3143 hardware-acceleration for SHA1/SHA256 progressive hashing.
3144 Data can be streamed in a block at a time and the hashing
3145 is performed in hardware.
3147 Note: There is also a sha1sum command, which should perhaps
3148 be deprecated in favour of 'hash sha1'.
3150 - Freescale i.MX specific commands:
3151 CONFIG_CMD_HDMIDETECT
3152 This enables 'hdmidet' command which returns true if an
3153 HDMI monitor is detected. This command is i.MX 6 specific.
3156 This enables the 'bmode' (bootmode) command for forcing
3157 a boot from specific media.
3159 This is useful for forcing the ROM's usb downloader to
3160 activate upon a watchdog reset which is nice when iterating
3161 on U-Boot. Using the reset button or running bmode normal
3162 will set it back to normal. This command currently
3163 supports i.MX53 and i.MX6.
3168 This enables the RSA algorithm used for FIT image verification
3169 in U-Boot. See doc/uImage.FIT/signature.txt for more information.
3171 The Modular Exponentiation algorithm in RSA is implemented using
3172 driver model. So CONFIG_DM needs to be enabled by default for this
3173 library to function.
3175 The signing part is build into mkimage regardless of this
3176 option. The software based modular exponentiation is built into
3177 mkimage irrespective of this option.
3179 - bootcount support:
3180 CONFIG_BOOTCOUNT_LIMIT
3182 This enables the bootcounter support, see:
3183 http://www.denx.de/wiki/DULG/UBootBootCountLimit
3186 enable special bootcounter support on at91sam9xe based boards.
3188 enable special bootcounter support on blackfin based boards.
3190 enable special bootcounter support on da850 based boards.
3191 CONFIG_BOOTCOUNT_RAM
3192 enable support for the bootcounter in RAM
3193 CONFIG_BOOTCOUNT_I2C
3194 enable support for the bootcounter on an i2c (like RTC) device.
3195 CONFIG_SYS_I2C_RTC_ADDR = i2c chip address
3196 CONFIG_SYS_BOOTCOUNT_ADDR = i2c addr which is used for
3198 CONFIG_BOOTCOUNT_ALEN = address len
3200 - Show boot progress:
3201 CONFIG_SHOW_BOOT_PROGRESS
3203 Defining this option allows to add some board-
3204 specific code (calling a user-provided function
3205 "show_boot_progress(int)") that enables you to show
3206 the system's boot progress on some display (for
3207 example, some LED's) on your board. At the moment,
3208 the following checkpoints are implemented:
3210 - Detailed boot stage timing
3212 Define this option to get detailed timing of each stage
3213 of the boot process.
3215 CONFIG_BOOTSTAGE_USER_COUNT
3216 This is the number of available user bootstage records.
3217 Each time you call bootstage_mark(BOOTSTAGE_ID_ALLOC, ...)
3218 a new ID will be allocated from this stash. If you exceed
3219 the limit, recording will stop.
3221 CONFIG_BOOTSTAGE_REPORT
3222 Define this to print a report before boot, similar to this:
3224 Timer summary in microseconds:
3227 3,575,678 3,575,678 board_init_f start
3228 3,575,695 17 arch_cpu_init A9
3229 3,575,777 82 arch_cpu_init done
3230 3,659,598 83,821 board_init_r start
3231 3,910,375 250,777 main_loop
3232 29,916,167 26,005,792 bootm_start
3233 30,361,327 445,160 start_kernel
3235 CONFIG_CMD_BOOTSTAGE
3236 Add a 'bootstage' command which supports printing a report
3237 and un/stashing of bootstage data.
3239 CONFIG_BOOTSTAGE_FDT
3240 Stash the bootstage information in the FDT. A root 'bootstage'
3241 node is created with each bootstage id as a child. Each child
3242 has a 'name' property and either 'mark' containing the
3243 mark time in microsecond, or 'accum' containing the
3244 accumulated time for that bootstage id in microseconds.
3249 name = "board_init_f";
3258 Code in the Linux kernel can find this in /proc/devicetree.
3260 Legacy uImage format:
3263 1 common/cmd_bootm.c before attempting to boot an image
3264 -1 common/cmd_bootm.c Image header has bad magic number
3265 2 common/cmd_bootm.c Image header has correct magic number
3266 -2 common/cmd_bootm.c Image header has bad checksum
3267 3 common/cmd_bootm.c Image header has correct checksum
3268 -3 common/cmd_bootm.c Image data has bad checksum
3269 4 common/cmd_bootm.c Image data has correct checksum
3270 -4 common/cmd_bootm.c Image is for unsupported architecture
3271 5 common/cmd_bootm.c Architecture check OK
3272 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi)
3273 6 common/cmd_bootm.c Image Type check OK
3274 -6 common/cmd_bootm.c gunzip uncompression error
3275 -7 common/cmd_bootm.c Unimplemented compression type
3276 7 common/cmd_bootm.c Uncompression OK
3277 8 common/cmd_bootm.c No uncompress/copy overwrite error
3278 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX)
3280 9 common/image.c Start initial ramdisk verification
3281 -10 common/image.c Ramdisk header has bad magic number
3282 -11 common/image.c Ramdisk header has bad checksum
3283 10 common/image.c Ramdisk header is OK
3284 -12 common/image.c Ramdisk data has bad checksum
3285 11 common/image.c Ramdisk data has correct checksum
3286 12 common/image.c Ramdisk verification complete, start loading
3287 -13 common/image.c Wrong Image Type (not PPC Linux ramdisk)
3288 13 common/image.c Start multifile image verification
3289 14 common/image.c No initial ramdisk, no multifile, continue.
3291 15 arch/<arch>/lib/bootm.c All preparation done, transferring control to OS
3293 -30 arch/powerpc/lib/board.c Fatal error, hang the system
3294 -31 post/post.c POST test failed, detected by post_output_backlog()
3295 -32 post/post.c POST test failed, detected by post_run_single()
3297 34 common/cmd_doc.c before loading a Image from a DOC device
3298 -35 common/cmd_doc.c Bad usage of "doc" command
3299 35 common/cmd_doc.c correct usage of "doc" command
3300 -36 common/cmd_doc.c No boot device
3301 36 common/cmd_doc.c correct boot device
3302 -37 common/cmd_doc.c Unknown Chip ID on boot device
3303 37 common/cmd_doc.c correct chip ID found, device available
3304 -38 common/cmd_doc.c Read Error on boot device
3305 38 common/cmd_doc.c reading Image header from DOC device OK
3306 -39 common/cmd_doc.c Image header has bad magic number
3307 39 common/cmd_doc.c Image header has correct magic number
3308 -40 common/cmd_doc.c Error reading Image from DOC device
3309 40 common/cmd_doc.c Image header has correct magic number
3310 41 common/cmd_ide.c before loading a Image from a IDE device
3311 -42 common/cmd_ide.c Bad usage of "ide" command
3312 42 common/cmd_ide.c correct usage of "ide" command
3313 -43 common/cmd_ide.c No boot device
3314 43 common/cmd_ide.c boot device found
3315 -44 common/cmd_ide.c Device not available
3316 44 common/cmd_ide.c Device available
3317 -45 common/cmd_ide.c wrong partition selected
3318 45 common/cmd_ide.c partition selected
3319 -46 common/cmd_ide.c Unknown partition table
3320 46 common/cmd_ide.c valid partition table found
3321 -47 common/cmd_ide.c Invalid partition type
3322 47 common/cmd_ide.c correct partition type
3323 -48 common/cmd_ide.c Error reading Image Header on boot device
3324 48 common/cmd_ide.c reading Image Header from IDE device OK
3325 -49 common/cmd_ide.c Image header has bad magic number
3326 49 common/cmd_ide.c Image header has correct magic number
3327 -50 common/cmd_ide.c Image header has bad checksum
3328 50 common/cmd_ide.c Image header has correct checksum
3329 -51 common/cmd_ide.c Error reading Image from IDE device
3330 51 common/cmd_ide.c reading Image from IDE device OK
3331 52 common/cmd_nand.c before loading a Image from a NAND device
3332 -53 common/cmd_nand.c Bad usage of "nand" command
3333 53 common/cmd_nand.c correct usage of "nand" command
3334 -54 common/cmd_nand.c No boot device
3335 54 common/cmd_nand.c boot device found
3336 -55 common/cmd_nand.c Unknown Chip ID on boot device
3337 55 common/cmd_nand.c correct chip ID found, device available
3338 -56 common/cmd_nand.c Error reading Image Header on boot device
3339 56 common/cmd_nand.c reading Image Header from NAND device OK
3340 -57 common/cmd_nand.c Image header has bad magic number
3341 57 common/cmd_nand.c Image header has correct magic number
3342 -58 common/cmd_nand.c Error reading Image from NAND device
3343 58 common/cmd_nand.c reading Image from NAND device OK
3345 -60 common/env_common.c Environment has a bad CRC, using default
3347 64 net/eth.c starting with Ethernet configuration.
3348 -64 net/eth.c no Ethernet found.
3349 65 net/eth.c Ethernet found.
3351 -80 common/cmd_net.c usage wrong
3352 80 common/cmd_net.c before calling NetLoop()
3353 -81 common/cmd_net.c some error in NetLoop() occurred
3354 81 common/cmd_net.c NetLoop() back without error
3355 -82 common/cmd_net.c size == 0 (File with size 0 loaded)
3356 82 common/cmd_net.c trying automatic boot
3357 83 common/cmd_net.c running "source" command
3358 -83 common/cmd_net.c some error in automatic boot or "source" command
3359 84 common/cmd_net.c end without errors
3364 100 common/cmd_bootm.c Kernel FIT Image has correct format
3365 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format
3366 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration
3367 -101 common/cmd_bootm.c Can't get configuration for kernel subimage
3368 102 common/cmd_bootm.c Kernel unit name specified
3369 -103 common/cmd_bootm.c Can't get kernel subimage node offset
3370 103 common/cmd_bootm.c Found configuration node
3371 104 common/cmd_bootm.c Got kernel subimage node offset
3372 -104 common/cmd_bootm.c Kernel subimage hash verification failed
3373 105 common/cmd_bootm.c Kernel subimage hash verification OK
3374 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture
3375 106 common/cmd_bootm.c Architecture check OK
3376 -106 common/cmd_bootm.c Kernel subimage has wrong type
3377 107 common/cmd_bootm.c Kernel subimage type OK
3378 -107 common/cmd_bootm.c Can't get kernel subimage data/size
3379 108 common/cmd_bootm.c Got kernel subimage data/size
3380 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT)
3381 -109 common/cmd_bootm.c Can't get kernel subimage type
3382 -110 common/cmd_bootm.c Can't get kernel subimage comp
3383 -111 common/cmd_bootm.c Can't get kernel subimage os
3384 -112 common/cmd_bootm.c Can't get kernel subimage load address
3385 -113 common/cmd_bootm.c Image uncompress/copy overwrite error
3387 120 common/image.c Start initial ramdisk verification
3388 -120 common/image.c Ramdisk FIT image has incorrect format
3389 121 common/image.c Ramdisk FIT image has correct format
3390 122 common/image.c No ramdisk subimage unit name, using configuration
3391 -122 common/image.c Can't get configuration for ramdisk subimage
3392 123 common/image.c Ramdisk unit name specified
3393 -124 common/image.c Can't get ramdisk subimage node offset
3394 125 common/image.c Got ramdisk subimage node offset
3395 -125 common/image.c Ramdisk subimage hash verification failed
3396 126 common/image.c Ramdisk subimage hash verification OK
3397 -126 common/image.c Ramdisk subimage for unsupported architecture
3398 127 common/image.c Architecture check OK
3399 -127 common/image.c Can't get ramdisk subimage data/size
3400 128 common/image.c Got ramdisk subimage data/size
3401 129 common/image.c Can't get ramdisk load address
3402 -129 common/image.c Got ramdisk load address
3404 -130 common/cmd_doc.c Incorrect FIT image format
3405 131 common/cmd_doc.c FIT image format OK
3407 -140 common/cmd_ide.c Incorrect FIT image format
3408 141 common/cmd_ide.c FIT image format OK
3410 -150 common/cmd_nand.c Incorrect FIT image format
3411 151 common/cmd_nand.c FIT image format OK
3413 - legacy image format:
3414 CONFIG_IMAGE_FORMAT_LEGACY
3415 enables the legacy image format support in U-Boot.
3418 enabled if CONFIG_FIT_SIGNATURE is not defined.
3420 CONFIG_DISABLE_IMAGE_LEGACY
3421 disable the legacy image format
3423 This define is introduced, as the legacy image format is
3424 enabled per default for backward compatibility.
3426 - FIT image support:
3428 Enable support for the FIT uImage format.
3430 CONFIG_FIT_BEST_MATCH
3431 When no configuration is explicitly selected, default to the
3432 one whose fdt's compatibility field best matches that of
3433 U-Boot itself. A match is considered "best" if it matches the
3434 most specific compatibility entry of U-Boot's fdt's root node.
3435 The order of entries in the configuration's fdt is ignored.
3437 CONFIG_FIT_SIGNATURE
3438 This option enables signature verification of FIT uImages,
3439 using a hash signed and verified using RSA. If
3440 CONFIG_SHA_PROG_HW_ACCEL is defined, i.e support for progressive
3441 hashing is available using hardware, RSA library will use it.
3442 See doc/uImage.FIT/signature.txt for more details.
3444 WARNING: When relying on signed FIT images with required
3445 signature check the legacy image format is default
3446 disabled. If a board need legacy image format support
3447 enable this through CONFIG_IMAGE_FORMAT_LEGACY
3449 CONFIG_FIT_DISABLE_SHA256
3450 Supporting SHA256 hashes has quite an impact on binary size.
3451 For constrained systems sha256 hash support can be disabled
3454 - Standalone program support:
3455 CONFIG_STANDALONE_LOAD_ADDR
3457 This option defines a board specific value for the
3458 address where standalone program gets loaded, thus
3459 overwriting the architecture dependent default
3462 - Frame Buffer Address:
3465 Define CONFIG_FB_ADDR if you want to use specific
3466 address for frame buffer. This is typically the case
3467 when using a graphics controller has separate video
3468 memory. U-Boot will then place the frame buffer at
3469 the given address instead of dynamically reserving it
3470 in system RAM by calling lcd_setmem(), which grabs
3471 the memory for the frame buffer depending on the
3472 configured panel size.
3474 Please see board_init_f function.
3476 - Automatic software updates via TFTP server
3478 CONFIG_UPDATE_TFTP_CNT_MAX
3479 CONFIG_UPDATE_TFTP_MSEC_MAX
3481 These options enable and control the auto-update feature;
3482 for a more detailed description refer to doc/README.update.
3484 - MTD Support (mtdparts command, UBI support)
3487 Adds the MTD device infrastructure from the Linux kernel.
3488 Needed for mtdparts command support.
3490 CONFIG_MTD_PARTITIONS
3492 Adds the MTD partitioning infrastructure from the Linux
3493 kernel. Needed for UBI support.
3495 CONFIG_MTD_NAND_VERIFY_WRITE
3496 verify if the written data is correct reread.
3501 Adds commands for interacting with MTD partitions formatted
3502 with the UBI flash translation layer
3504 Requires also defining CONFIG_RBTREE
3506 CONFIG_UBI_SILENCE_MSG
3508 Make the verbose messages from UBI stop printing. This leaves
3509 warnings and errors enabled.
3512 CONFIG_MTD_UBI_WL_THRESHOLD
3513 This parameter defines the maximum difference between the highest
3514 erase counter value and the lowest erase counter value of eraseblocks
3515 of UBI devices. When this threshold is exceeded, UBI starts performing
3516 wear leveling by means of moving data from eraseblock with low erase
3517 counter to eraseblocks with high erase counter.
3519 The default value should be OK for SLC NAND flashes, NOR flashes and
3520 other flashes which have eraseblock life-cycle 100000 or more.
3521 However, in case of MLC NAND flashes which typically have eraseblock
3522 life-cycle less than 10000, the threshold should be lessened (e.g.,
3523 to 128 or 256, although it does not have to be power of 2).
3527 CONFIG_MTD_UBI_BEB_LIMIT
3528 This option specifies the maximum bad physical eraseblocks UBI
3529 expects on the MTD device (per 1024 eraseblocks). If the
3530 underlying flash does not admit of bad eraseblocks (e.g. NOR
3531 flash), this value is ignored.
3533 NAND datasheets often specify the minimum and maximum NVM
3534 (Number of Valid Blocks) for the flashes' endurance lifetime.
3535 The maximum expected bad eraseblocks per 1024 eraseblocks
3536 then can be calculated as "1024 * (1 - MinNVB / MaxNVB)",
3537 which gives 20 for most NANDs (MaxNVB is basically the total
3538 count of eraseblocks on the chip).
3540 To put it differently, if this value is 20, UBI will try to
3541 reserve about 1.9% of physical eraseblocks for bad blocks
3542 handling. And that will be 1.9% of eraseblocks on the entire
3543 NAND chip, not just the MTD partition UBI attaches. This means
3544 that if you have, say, a NAND flash chip admits maximum 40 bad
3545 eraseblocks, and it is split on two MTD partitions of the same
3546 size, UBI will reserve 40 eraseblocks when attaching a
3551 CONFIG_MTD_UBI_FASTMAP
3552 Fastmap is a mechanism which allows attaching an UBI device
3553 in nearly constant time. Instead of scanning the whole MTD device it
3554 only has to locate a checkpoint (called fastmap) on the device.
3555 The on-flash fastmap contains all information needed to attach
3556 the device. Using fastmap makes only sense on large devices where
3557 attaching by scanning takes long. UBI will not automatically install
3558 a fastmap on old images, but you can set the UBI parameter
3559 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT to 1 if you want so. Please note
3560 that fastmap-enabled images are still usable with UBI implementations
3561 without fastmap support. On typical flash devices the whole fastmap
3562 fits into one PEB. UBI will reserve PEBs to hold two fastmaps.
3564 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT
3565 Set this parameter to enable fastmap automatically on images
3572 Adds commands for interacting with UBI volumes formatted as
3573 UBIFS. UBIFS is read-only in u-boot.
3575 Requires UBI support as well as CONFIG_LZO
3577 CONFIG_UBIFS_SILENCE_MSG
3579 Make the verbose messages from UBIFS stop printing. This leaves
3580 warnings and errors enabled.
3584 Enable building of SPL globally.
3587 LDSCRIPT for linking the SPL binary.
3589 CONFIG_SPL_MAX_FOOTPRINT
3590 Maximum size in memory allocated to the SPL, BSS included.
3591 When defined, the linker checks that the actual memory
3592 used by SPL from _start to __bss_end does not exceed it.
3593 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
3594 must not be both defined at the same time.
3597 Maximum size of the SPL image (text, data, rodata, and
3598 linker lists sections), BSS excluded.
3599 When defined, the linker checks that the actual size does
3602 CONFIG_SPL_TEXT_BASE
3603 TEXT_BASE for linking the SPL binary.
3605 CONFIG_SPL_RELOC_TEXT_BASE
3606 Address to relocate to. If unspecified, this is equal to
3607 CONFIG_SPL_TEXT_BASE (i.e. no relocation is done).
3609 CONFIG_SPL_BSS_START_ADDR
3610 Link address for the BSS within the SPL binary.
3612 CONFIG_SPL_BSS_MAX_SIZE
3613 Maximum size in memory allocated to the SPL BSS.
3614 When defined, the linker checks that the actual memory used
3615 by SPL from __bss_start to __bss_end does not exceed it.
3616 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
3617 must not be both defined at the same time.
3620 Adress of the start of the stack SPL will use
3622 CONFIG_SPL_RELOC_STACK
3623 Adress of the start of the stack SPL will use after
3624 relocation. If unspecified, this is equal to
3627 CONFIG_SYS_SPL_MALLOC_START
3628 Starting address of the malloc pool used in SPL.
3630 CONFIG_SYS_SPL_MALLOC_SIZE
3631 The size of the malloc pool used in SPL.
3633 CONFIG_SPL_FRAMEWORK
3634 Enable the SPL framework under common/. This framework
3635 supports MMC, NAND and YMODEM loading of U-Boot and NAND
3636 NAND loading of the Linux Kernel.
3639 Enable booting directly to an OS from SPL.
3640 See also: doc/README.falcon
3642 CONFIG_SPL_DISPLAY_PRINT
3643 For ARM, enable an optional function to print more information
3644 about the running system.
3646 CONFIG_SPL_INIT_MINIMAL
3647 Arch init code should be built for a very small image
3649 CONFIG_SPL_LIBCOMMON_SUPPORT
3650 Support for common/libcommon.o in SPL binary
3652 CONFIG_SPL_LIBDISK_SUPPORT
3653 Support for disk/libdisk.o in SPL binary
3655 CONFIG_SPL_I2C_SUPPORT
3656 Support for drivers/i2c/libi2c.o in SPL binary
3658 CONFIG_SPL_GPIO_SUPPORT
3659 Support for drivers/gpio/libgpio.o in SPL binary
3661 CONFIG_SPL_MMC_SUPPORT
3662 Support for drivers/mmc/libmmc.o in SPL binary
3664 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_SECTOR,
3665 CONFIG_SYS_U_BOOT_MAX_SIZE_SECTORS,
3666 Address and partition on the MMC to load U-Boot from
3667 when the MMC is being used in raw mode.
3669 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_PARTITION
3670 Partition on the MMC to load U-Boot from when the MMC is being
3673 CONFIG_SYS_MMCSD_RAW_MODE_KERNEL_SECTOR
3674 Sector to load kernel uImage from when MMC is being
3675 used in raw mode (for Falcon mode)
3677 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTOR,
3678 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTORS
3679 Sector and number of sectors to load kernel argument
3680 parameters from when MMC is being used in raw mode
3683 CONFIG_SYS_MMCSD_FS_BOOT_PARTITION
3684 Partition on the MMC to load U-Boot from when the MMC is being
3687 CONFIG_SPL_FAT_SUPPORT
3688 Support for fs/fat/libfat.o in SPL binary
3690 CONFIG_SPL_EXT_SUPPORT
3691 Support for EXT filesystem in SPL binary
3693 CONFIG_SPL_FS_LOAD_PAYLOAD_NAME
3694 Filename to read to load U-Boot when reading from filesystem
3696 CONFIG_SPL_FS_LOAD_KERNEL_NAME
3697 Filename to read to load kernel uImage when reading
3698 from filesystem (for Falcon mode)
3700 CONFIG_SPL_FS_LOAD_ARGS_NAME
3701 Filename to read to load kernel argument parameters
3702 when reading from filesystem (for Falcon mode)
3704 CONFIG_SPL_MPC83XX_WAIT_FOR_NAND
3705 Set this for NAND SPL on PPC mpc83xx targets, so that
3706 start.S waits for the rest of the SPL to load before
3707 continuing (the hardware starts execution after just
3708 loading the first page rather than the full 4K).
3710 CONFIG_SPL_SKIP_RELOCATE
3711 Avoid SPL relocation
3713 CONFIG_SPL_NAND_BASE
3714 Include nand_base.c in the SPL. Requires
3715 CONFIG_SPL_NAND_DRIVERS.
3717 CONFIG_SPL_NAND_DRIVERS
3718 SPL uses normal NAND drivers, not minimal drivers.
3721 Include standard software ECC in the SPL
3723 CONFIG_SPL_NAND_SIMPLE
3724 Support for NAND boot using simple NAND drivers that
3725 expose the cmd_ctrl() interface.
3727 CONFIG_SPL_MTD_SUPPORT
3728 Support for the MTD subsystem within SPL. Useful for
3729 environment on NAND support within SPL.
3731 CONFIG_SPL_NAND_RAW_ONLY
3732 Support to boot only raw u-boot.bin images. Use this only
3733 if you need to save space.
3735 CONFIG_SPL_MPC8XXX_INIT_DDR_SUPPORT
3736 Set for the SPL on PPC mpc8xxx targets, support for
3737 drivers/ddr/fsl/libddr.o in SPL binary.
3739 CONFIG_SPL_COMMON_INIT_DDR
3740 Set for common ddr init with serial presence detect in
3743 CONFIG_SYS_NAND_5_ADDR_CYCLE, CONFIG_SYS_NAND_PAGE_COUNT,
3744 CONFIG_SYS_NAND_PAGE_SIZE, CONFIG_SYS_NAND_OOBSIZE,
3745 CONFIG_SYS_NAND_BLOCK_SIZE, CONFIG_SYS_NAND_BAD_BLOCK_POS,
3746 CONFIG_SYS_NAND_ECCPOS, CONFIG_SYS_NAND_ECCSIZE,
3747 CONFIG_SYS_NAND_ECCBYTES
3748 Defines the size and behavior of the NAND that SPL uses
3751 CONFIG_SPL_NAND_BOOT
3752 Add support NAND boot
3754 CONFIG_SYS_NAND_U_BOOT_OFFS
3755 Location in NAND to read U-Boot from
3757 CONFIG_SYS_NAND_U_BOOT_DST
3758 Location in memory to load U-Boot to
3760 CONFIG_SYS_NAND_U_BOOT_SIZE
3761 Size of image to load
3763 CONFIG_SYS_NAND_U_BOOT_START
3764 Entry point in loaded image to jump to
3766 CONFIG_SYS_NAND_HW_ECC_OOBFIRST
3767 Define this if you need to first read the OOB and then the
3768 data. This is used, for example, on davinci platforms.
3770 CONFIG_SPL_OMAP3_ID_NAND
3771 Support for an OMAP3-specific set of functions to return the
3772 ID and MFR of the first attached NAND chip, if present.
3774 CONFIG_SPL_SERIAL_SUPPORT
3775 Support for drivers/serial/libserial.o in SPL binary
3777 CONFIG_SPL_SPI_FLASH_SUPPORT
3778 Support for drivers/mtd/spi/libspi_flash.o in SPL binary
3780 CONFIG_SPL_SPI_SUPPORT
3781 Support for drivers/spi/libspi.o in SPL binary
3783 CONFIG_SPL_RAM_DEVICE
3784 Support for running image already present in ram, in SPL binary
3786 CONFIG_SPL_LIBGENERIC_SUPPORT
3787 Support for lib/libgeneric.o in SPL binary
3789 CONFIG_SPL_ENV_SUPPORT
3790 Support for the environment operating in SPL binary
3792 CONFIG_SPL_NET_SUPPORT
3793 Support for the net/libnet.o in SPL binary.
3794 It conflicts with SPL env from storage medium specified by
3795 CONFIG_ENV_IS_xxx but CONFIG_ENV_IS_NOWHERE
3798 Image offset to which the SPL should be padded before appending
3799 the SPL payload. By default, this is defined as
3800 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3801 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3802 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3805 Final target image containing SPL and payload. Some SPLs
3806 use an arch-specific makefile fragment instead, for
3807 example if more than one image needs to be produced.
3809 CONFIG_FIT_SPL_PRINT
3810 Printing information about a FIT image adds quite a bit of
3811 code to SPL. So this is normally disabled in SPL. Use this
3812 option to re-enable it. This will affect the output of the
3813 bootm command when booting a FIT image.
3817 Enable building of TPL globally.
3820 Image offset to which the TPL should be padded before appending
3821 the TPL payload. By default, this is defined as
3822 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3823 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3824 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3829 [so far only for SMDK2400 boards]
3831 - Modem support enable:
3832 CONFIG_MODEM_SUPPORT
3834 - RTS/CTS Flow control enable:
3837 - Modem debug support:
3838 CONFIG_MODEM_SUPPORT_DEBUG
3840 Enables debugging stuff (char screen[1024], dbg())
3841 for modem support. Useful only with BDI2000.
3843 - Interrupt support (PPC):
3845 There are common interrupt_init() and timer_interrupt()
3846 for all PPC archs. interrupt_init() calls interrupt_init_cpu()
3847 for CPU specific initialization. interrupt_init_cpu()
3848 should set decrementer_count to appropriate value. If
3849 CPU resets decrementer automatically after interrupt
3850 (ppc4xx) it should set decrementer_count to zero.
3851 timer_interrupt() calls timer_interrupt_cpu() for CPU
3852 specific handling. If board has watchdog / status_led
3853 / other_activity_monitor it works automatically from
3854 general timer_interrupt().
3858 In the target system modem support is enabled when a
3859 specific key (key combination) is pressed during
3860 power-on. Otherwise U-Boot will boot normally
3861 (autoboot). The key_pressed() function is called from
3862 board_init(). Currently key_pressed() is a dummy
3863 function, returning 1 and thus enabling modem
3866 If there are no modem init strings in the
3867 environment, U-Boot proceed to autoboot; the
3868 previous output (banner, info printfs) will be
3871 See also: doc/README.Modem
3873 Board initialization settings:
3874 ------------------------------
3876 During Initialization u-boot calls a number of board specific functions
3877 to allow the preparation of board specific prerequisites, e.g. pin setup
3878 before drivers are initialized. To enable these callbacks the
3879 following configuration macros have to be defined. Currently this is
3880 architecture specific, so please check arch/your_architecture/lib/board.c
3881 typically in board_init_f() and board_init_r().
3883 - CONFIG_BOARD_EARLY_INIT_F: Call board_early_init_f()
3884 - CONFIG_BOARD_EARLY_INIT_R: Call board_early_init_r()
3885 - CONFIG_BOARD_LATE_INIT: Call board_late_init()
3886 - CONFIG_BOARD_POSTCLK_INIT: Call board_postclk_init()
3888 Configuration Settings:
3889 -----------------------
3891 - CONFIG_SYS_SUPPORT_64BIT_DATA: Defined automatically if compiled as 64-bit.
3892 Optionally it can be defined to support 64-bit memory commands.
3894 - CONFIG_SYS_LONGHELP: Defined when you want long help messages included;
3895 undefine this when you're short of memory.
3897 - CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default
3898 width of the commands listed in the 'help' command output.
3900 - CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to
3901 prompt for user input.
3903 - CONFIG_SYS_CBSIZE: Buffer size for input from the Console
3905 - CONFIG_SYS_PBSIZE: Buffer size for Console output
3907 - CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands
3909 - CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to
3910 the application (usually a Linux kernel) when it is
3913 - CONFIG_SYS_BAUDRATE_TABLE:
3914 List of legal baudrate settings for this board.
3916 - CONFIG_SYS_CONSOLE_INFO_QUIET
3917 Suppress display of console information at boot.
3919 - CONFIG_SYS_CONSOLE_IS_IN_ENV
3920 If the board specific function
3921 extern int overwrite_console (void);
3922 returns 1, the stdin, stderr and stdout are switched to the
3923 serial port, else the settings in the environment are used.
3925 - CONFIG_SYS_CONSOLE_OVERWRITE_ROUTINE
3926 Enable the call to overwrite_console().
3928 - CONFIG_SYS_CONSOLE_ENV_OVERWRITE
3929 Enable overwrite of previous console environment settings.
3931 - CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END:
3932 Begin and End addresses of the area used by the
3935 - CONFIG_SYS_ALT_MEMTEST:
3936 Enable an alternate, more extensive memory test.
3938 - CONFIG_SYS_MEMTEST_SCRATCH:
3939 Scratch address used by the alternate memory test
3940 You only need to set this if address zero isn't writeable
3942 - CONFIG_SYS_MEM_TOP_HIDE (PPC only):
3943 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header,
3944 this specified memory area will get subtracted from the top
3945 (end) of RAM and won't get "touched" at all by U-Boot. By
3946 fixing up gd->ram_size the Linux kernel should gets passed
3947 the now "corrected" memory size and won't touch it either.
3948 This should work for arch/ppc and arch/powerpc. Only Linux
3949 board ports in arch/powerpc with bootwrapper support that
3950 recalculate the memory size from the SDRAM controller setup
3951 will have to get fixed in Linux additionally.
3953 This option can be used as a workaround for the 440EPx/GRx
3954 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't
3957 WARNING: Please make sure that this value is a multiple of
3958 the Linux page size (normally 4k). If this is not the case,
3959 then the end address of the Linux memory will be located at a
3960 non page size aligned address and this could cause major
3963 - CONFIG_SYS_LOADS_BAUD_CHANGE:
3964 Enable temporary baudrate change while serial download
3966 - CONFIG_SYS_SDRAM_BASE:
3967 Physical start address of SDRAM. _Must_ be 0 here.
3969 - CONFIG_SYS_MBIO_BASE:
3970 Physical start address of Motherboard I/O (if using a
3973 - CONFIG_SYS_FLASH_BASE:
3974 Physical start address of Flash memory.
3976 - CONFIG_SYS_MONITOR_BASE:
3977 Physical start address of boot monitor code (set by
3978 make config files to be same as the text base address
3979 (CONFIG_SYS_TEXT_BASE) used when linking) - same as
3980 CONFIG_SYS_FLASH_BASE when booting from flash.
3982 - CONFIG_SYS_MONITOR_LEN:
3983 Size of memory reserved for monitor code, used to
3984 determine _at_compile_time_ (!) if the environment is
3985 embedded within the U-Boot image, or in a separate
3988 - CONFIG_SYS_MALLOC_LEN:
3989 Size of DRAM reserved for malloc() use.
3991 - CONFIG_SYS_MALLOC_F_LEN
3992 Size of the malloc() pool for use before relocation. If
3993 this is defined, then a very simple malloc() implementation
3994 will become available before relocation. The address is just
3995 below the global data, and the stack is moved down to make
3998 This feature allocates regions with increasing addresses
3999 within the region. calloc() is supported, but realloc()
4000 is not available. free() is supported but does nothing.
4001 The memory will be freed (or in fact just forgotten) when
4002 U-Boot relocates itself.
4004 Pre-relocation malloc() is only supported on ARM and sandbox
4005 at present but is fairly easy to enable for other archs.
4007 - CONFIG_SYS_MALLOC_SIMPLE
4008 Provides a simple and small malloc() and calloc() for those
4009 boards which do not use the full malloc in SPL (which is
4010 enabled with CONFIG_SYS_SPL_MALLOC_START).
4012 - CONFIG_SYS_NONCACHED_MEMORY:
4013 Size of non-cached memory area. This area of memory will be
4014 typically located right below the malloc() area and mapped
4015 uncached in the MMU. This is useful for drivers that would
4016 otherwise require a lot of explicit cache maintenance. For
4017 some drivers it's also impossible to properly maintain the
4018 cache. For example if the regions that need to be flushed
4019 are not a multiple of the cache-line size, *and* padding
4020 cannot be allocated between the regions to align them (i.e.
4021 if the HW requires a contiguous array of regions, and the
4022 size of each region is not cache-aligned), then a flush of
4023 one region may result in overwriting data that hardware has
4024 written to another region in the same cache-line. This can
4025 happen for example in network drivers where descriptors for
4026 buffers are typically smaller than the CPU cache-line (e.g.
4027 16 bytes vs. 32 or 64 bytes).
4029 Non-cached memory is only supported on 32-bit ARM at present.
4031 - CONFIG_SYS_BOOTM_LEN:
4032 Normally compressed uImages are limited to an
4033 uncompressed size of 8 MBytes. If this is not enough,
4034 you can define CONFIG_SYS_BOOTM_LEN in your board config file
4035 to adjust this setting to your needs.
4037 - CONFIG_SYS_BOOTMAPSZ:
4038 Maximum size of memory mapped by the startup code of
4039 the Linux kernel; all data that must be processed by
4040 the Linux kernel (bd_info, boot arguments, FDT blob if
4041 used) must be put below this limit, unless "bootm_low"
4042 environment variable is defined and non-zero. In such case
4043 all data for the Linux kernel must be between "bootm_low"
4044 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ. The environment
4045 variable "bootm_mapsize" will override the value of
4046 CONFIG_SYS_BOOTMAPSZ. If CONFIG_SYS_BOOTMAPSZ is undefined,
4047 then the value in "bootm_size" will be used instead.
4049 - CONFIG_SYS_BOOT_RAMDISK_HIGH:
4050 Enable initrd_high functionality. If defined then the
4051 initrd_high feature is enabled and the bootm ramdisk subcommand
4054 - CONFIG_SYS_BOOT_GET_CMDLINE:
4055 Enables allocating and saving kernel cmdline in space between
4056 "bootm_low" and "bootm_low" + BOOTMAPSZ.
4058 - CONFIG_SYS_BOOT_GET_KBD:
4059 Enables allocating and saving a kernel copy of the bd_info in
4060 space between "bootm_low" and "bootm_low" + BOOTMAPSZ.
4062 - CONFIG_SYS_MAX_FLASH_BANKS:
4063 Max number of Flash memory banks
4065 - CONFIG_SYS_MAX_FLASH_SECT:
4066 Max number of sectors on a Flash chip
4068 - CONFIG_SYS_FLASH_ERASE_TOUT:
4069 Timeout for Flash erase operations (in ms)
4071 - CONFIG_SYS_FLASH_WRITE_TOUT:
4072 Timeout for Flash write operations (in ms)
4074 - CONFIG_SYS_FLASH_LOCK_TOUT
4075 Timeout for Flash set sector lock bit operation (in ms)
4077 - CONFIG_SYS_FLASH_UNLOCK_TOUT
4078 Timeout for Flash clear lock bits operation (in ms)
4080 - CONFIG_SYS_FLASH_PROTECTION
4081 If defined, hardware flash sectors protection is used
4082 instead of U-Boot software protection.
4084 - CONFIG_SYS_DIRECT_FLASH_TFTP:
4086 Enable TFTP transfers directly to flash memory;
4087 without this option such a download has to be
4088 performed in two steps: (1) download to RAM, and (2)
4089 copy from RAM to flash.
4091 The two-step approach is usually more reliable, since
4092 you can check if the download worked before you erase
4093 the flash, but in some situations (when system RAM is
4094 too limited to allow for a temporary copy of the
4095 downloaded image) this option may be very useful.
4097 - CONFIG_SYS_FLASH_CFI:
4098 Define if the flash driver uses extra elements in the
4099 common flash structure for storing flash geometry.
4101 - CONFIG_FLASH_CFI_DRIVER
4102 This option also enables the building of the cfi_flash driver
4103 in the drivers directory
4105 - CONFIG_FLASH_CFI_MTD
4106 This option enables the building of the cfi_mtd driver
4107 in the drivers directory. The driver exports CFI flash
4110 - CONFIG_SYS_FLASH_USE_BUFFER_WRITE
4111 Use buffered writes to flash.
4113 - CONFIG_FLASH_SPANSION_S29WS_N
4114 s29ws-n MirrorBit flash has non-standard addresses for buffered
4117 - CONFIG_SYS_FLASH_QUIET_TEST
4118 If this option is defined, the common CFI flash doesn't
4119 print it's warning upon not recognized FLASH banks. This
4120 is useful, if some of the configured banks are only
4121 optionally available.
4123 - CONFIG_FLASH_SHOW_PROGRESS
4124 If defined (must be an integer), print out countdown
4125 digits and dots. Recommended value: 45 (9..1) for 80
4126 column displays, 15 (3..1) for 40 column displays.
4128 - CONFIG_FLASH_VERIFY
4129 If defined, the content of the flash (destination) is compared
4130 against the source after the write operation. An error message
4131 will be printed when the contents are not identical.
4132 Please note that this option is useless in nearly all cases,
4133 since such flash programming errors usually are detected earlier
4134 while unprotecting/erasing/programming. Please only enable
4135 this option if you really know what you are doing.
4137 - CONFIG_SYS_RX_ETH_BUFFER:
4138 Defines the number of Ethernet receive buffers. On some
4139 Ethernet controllers it is recommended to set this value
4140 to 8 or even higher (EEPRO100 or 405 EMAC), since all
4141 buffers can be full shortly after enabling the interface
4142 on high Ethernet traffic.
4143 Defaults to 4 if not defined.
4145 - CONFIG_ENV_MAX_ENTRIES
4147 Maximum number of entries in the hash table that is used
4148 internally to store the environment settings. The default
4149 setting is supposed to be generous and should work in most
4150 cases. This setting can be used to tune behaviour; see
4151 lib/hashtable.c for details.
4153 - CONFIG_ENV_FLAGS_LIST_DEFAULT
4154 - CONFIG_ENV_FLAGS_LIST_STATIC
4155 Enable validation of the values given to environment variables when
4156 calling env set. Variables can be restricted to only decimal,
4157 hexadecimal, or boolean. If CONFIG_CMD_NET is also defined,
4158 the variables can also be restricted to IP address or MAC address.
4160 The format of the list is:
4161 type_attribute = [s|d|x|b|i|m]
4162 access_attribute = [a|r|o|c]
4163 attributes = type_attribute[access_attribute]
4164 entry = variable_name[:attributes]
4167 The type attributes are:
4168 s - String (default)
4171 b - Boolean ([1yYtT|0nNfF])
4175 The access attributes are:
4181 - CONFIG_ENV_FLAGS_LIST_DEFAULT
4182 Define this to a list (string) to define the ".flags"
4183 environment variable in the default or embedded environment.
4185 - CONFIG_ENV_FLAGS_LIST_STATIC
4186 Define this to a list (string) to define validation that
4187 should be done if an entry is not found in the ".flags"
4188 environment variable. To override a setting in the static
4189 list, simply add an entry for the same variable name to the
4192 - CONFIG_ENV_ACCESS_IGNORE_FORCE
4193 If defined, don't allow the -f switch to env set override variable
4196 - CONFIG_SYS_GENERIC_BOARD
4197 This selects the architecture-generic board system instead of the
4198 architecture-specific board files. It is intended to move boards
4199 to this new framework over time. Defining this will disable the
4200 arch/foo/lib/board.c file and use common/board_f.c and
4201 common/board_r.c instead. To use this option your architecture
4202 must support it (i.e. must define __HAVE_ARCH_GENERIC_BOARD in
4203 its config.mk file). If you find problems enabling this option on
4204 your board please report the problem and send patches!
4206 - CONFIG_OMAP_PLATFORM_RESET_TIME_MAX_USEC (OMAP only)
4207 This is set by OMAP boards for the max time that reset should
4208 be asserted. See doc/README.omap-reset-time for details on how
4209 the value can be calculated on a given board.
4212 If stdint.h is available with your toolchain you can define this
4213 option to enable it. You can provide option 'USE_STDINT=1' when
4214 building U-Boot to enable this.
4216 The following definitions that deal with the placement and management
4217 of environment data (variable area); in general, we support the
4218 following configurations:
4220 - CONFIG_BUILD_ENVCRC:
4222 Builds up envcrc with the target environment so that external utils
4223 may easily extract it and embed it in final U-Boot images.
4225 - CONFIG_ENV_IS_IN_FLASH:
4227 Define this if the environment is in flash memory.
4229 a) The environment occupies one whole flash sector, which is
4230 "embedded" in the text segment with the U-Boot code. This
4231 happens usually with "bottom boot sector" or "top boot
4232 sector" type flash chips, which have several smaller
4233 sectors at the start or the end. For instance, such a
4234 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In
4235 such a case you would place the environment in one of the
4236 4 kB sectors - with U-Boot code before and after it. With
4237 "top boot sector" type flash chips, you would put the
4238 environment in one of the last sectors, leaving a gap
4239 between U-Boot and the environment.
4241 - CONFIG_ENV_OFFSET:
4243 Offset of environment data (variable area) to the
4244 beginning of flash memory; for instance, with bottom boot
4245 type flash chips the second sector can be used: the offset
4246 for this sector is given here.
4248 CONFIG_ENV_OFFSET is used relative to CONFIG_SYS_FLASH_BASE.
4252 This is just another way to specify the start address of
4253 the flash sector containing the environment (instead of
4256 - CONFIG_ENV_SECT_SIZE:
4258 Size of the sector containing the environment.
4261 b) Sometimes flash chips have few, equal sized, BIG sectors.
4262 In such a case you don't want to spend a whole sector for
4267 If you use this in combination with CONFIG_ENV_IS_IN_FLASH
4268 and CONFIG_ENV_SECT_SIZE, you can specify to use only a part
4269 of this flash sector for the environment. This saves
4270 memory for the RAM copy of the environment.
4272 It may also save flash memory if you decide to use this
4273 when your environment is "embedded" within U-Boot code,
4274 since then the remainder of the flash sector could be used
4275 for U-Boot code. It should be pointed out that this is
4276 STRONGLY DISCOURAGED from a robustness point of view:
4277 updating the environment in flash makes it always
4278 necessary to erase the WHOLE sector. If something goes
4279 wrong before the contents has been restored from a copy in
4280 RAM, your target system will be dead.
4282 - CONFIG_ENV_ADDR_REDUND
4283 CONFIG_ENV_SIZE_REDUND
4285 These settings describe a second storage area used to hold
4286 a redundant copy of the environment data, so that there is
4287 a valid backup copy in case there is a power failure during
4288 a "saveenv" operation.
4290 BE CAREFUL! Any changes to the flash layout, and some changes to the
4291 source code will make it necessary to adapt <board>/u-boot.lds*
4295 - CONFIG_ENV_IS_IN_NVRAM:
4297 Define this if you have some non-volatile memory device
4298 (NVRAM, battery buffered SRAM) which you want to use for the
4304 These two #defines are used to determine the memory area you
4305 want to use for environment. It is assumed that this memory
4306 can just be read and written to, without any special
4309 BE CAREFUL! The first access to the environment happens quite early
4310 in U-Boot initialization (when we try to get the setting of for the
4311 console baudrate). You *MUST* have mapped your NVRAM area then, or
4314 Please note that even with NVRAM we still use a copy of the
4315 environment in RAM: we could work on NVRAM directly, but we want to
4316 keep settings there always unmodified except somebody uses "saveenv"
4317 to save the current settings.
4320 - CONFIG_ENV_IS_IN_EEPROM:
4322 Use this if you have an EEPROM or similar serial access
4323 device and a driver for it.
4325 - CONFIG_ENV_OFFSET:
4328 These two #defines specify the offset and size of the
4329 environment area within the total memory of your EEPROM.
4331 - CONFIG_SYS_I2C_EEPROM_ADDR:
4332 If defined, specified the chip address of the EEPROM device.
4333 The default address is zero.
4335 - CONFIG_SYS_I2C_EEPROM_BUS:
4336 If defined, specified the i2c bus of the EEPROM device.
4338 - CONFIG_SYS_EEPROM_PAGE_WRITE_BITS:
4339 If defined, the number of bits used to address bytes in a
4340 single page in the EEPROM device. A 64 byte page, for example
4341 would require six bits.
4343 - CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS:
4344 If defined, the number of milliseconds to delay between
4345 page writes. The default is zero milliseconds.
4347 - CONFIG_SYS_I2C_EEPROM_ADDR_LEN:
4348 The length in bytes of the EEPROM memory array address. Note
4349 that this is NOT the chip address length!
4351 - CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW:
4352 EEPROM chips that implement "address overflow" are ones
4353 like Catalyst 24WC04/08/16 which has 9/10/11 bits of
4354 address and the extra bits end up in the "chip address" bit
4355 slots. This makes a 24WC08 (1Kbyte) chip look like four 256
4358 Note that we consider the length of the address field to
4359 still be one byte because the extra address bits are hidden
4360 in the chip address.
4362 - CONFIG_SYS_EEPROM_SIZE:
4363 The size in bytes of the EEPROM device.
4365 - CONFIG_ENV_EEPROM_IS_ON_I2C
4366 define this, if you have I2C and SPI activated, and your
4367 EEPROM, which holds the environment, is on the I2C bus.
4369 - CONFIG_I2C_ENV_EEPROM_BUS
4370 if you have an Environment on an EEPROM reached over
4371 I2C muxes, you can define here, how to reach this
4372 EEPROM. For example:
4374 #define CONFIG_I2C_ENV_EEPROM_BUS 1
4376 EEPROM which holds the environment, is reached over
4377 a pca9547 i2c mux with address 0x70, channel 3.
4379 - CONFIG_ENV_IS_IN_DATAFLASH:
4381 Define this if you have a DataFlash memory device which you
4382 want to use for the environment.
4384 - CONFIG_ENV_OFFSET:
4388 These three #defines specify the offset and size of the
4389 environment area within the total memory of your DataFlash placed
4390 at the specified address.
4392 - CONFIG_ENV_IS_IN_SPI_FLASH:
4394 Define this if you have a SPI Flash memory device which you
4395 want to use for the environment.
4397 - CONFIG_ENV_OFFSET:
4400 These two #defines specify the offset and size of the
4401 environment area within the SPI Flash. CONFIG_ENV_OFFSET must be
4402 aligned to an erase sector boundary.
4404 - CONFIG_ENV_SECT_SIZE:
4406 Define the SPI flash's sector size.
4408 - CONFIG_ENV_OFFSET_REDUND (optional):
4410 This setting describes a second storage area of CONFIG_ENV_SIZE
4411 size used to hold a redundant copy of the environment data, so
4412 that there is a valid backup copy in case there is a power failure
4413 during a "saveenv" operation. CONFIG_ENV_OFFSET_RENDUND must be
4414 aligned to an erase sector boundary.
4416 - CONFIG_ENV_SPI_BUS (optional):
4417 - CONFIG_ENV_SPI_CS (optional):
4419 Define the SPI bus and chip select. If not defined they will be 0.
4421 - CONFIG_ENV_SPI_MAX_HZ (optional):
4423 Define the SPI max work clock. If not defined then use 1MHz.
4425 - CONFIG_ENV_SPI_MODE (optional):
4427 Define the SPI work mode. If not defined then use SPI_MODE_3.
4429 - CONFIG_ENV_IS_IN_REMOTE:
4431 Define this if you have a remote memory space which you
4432 want to use for the local device's environment.
4437 These two #defines specify the address and size of the
4438 environment area within the remote memory space. The
4439 local device can get the environment from remote memory
4440 space by SRIO or PCIE links.
4442 BE CAREFUL! For some special cases, the local device can not use
4443 "saveenv" command. For example, the local device will get the
4444 environment stored in a remote NOR flash by SRIO or PCIE link,
4445 but it can not erase, write this NOR flash by SRIO or PCIE interface.
4447 - CONFIG_ENV_IS_IN_NAND:
4449 Define this if you have a NAND device which you want to use
4450 for the environment.
4452 - CONFIG_ENV_OFFSET:
4455 These two #defines specify the offset and size of the environment
4456 area within the first NAND device. CONFIG_ENV_OFFSET must be
4457 aligned to an erase block boundary.
4459 - CONFIG_ENV_OFFSET_REDUND (optional):
4461 This setting describes a second storage area of CONFIG_ENV_SIZE
4462 size used to hold a redundant copy of the environment data, so
4463 that there is a valid backup copy in case there is a power failure
4464 during a "saveenv" operation. CONFIG_ENV_OFFSET_RENDUND must be
4465 aligned to an erase block boundary.
4467 - CONFIG_ENV_RANGE (optional):
4469 Specifies the length of the region in which the environment
4470 can be written. This should be a multiple of the NAND device's
4471 block size. Specifying a range with more erase blocks than
4472 are needed to hold CONFIG_ENV_SIZE allows bad blocks within
4473 the range to be avoided.
4475 - CONFIG_ENV_OFFSET_OOB (optional):
4477 Enables support for dynamically retrieving the offset of the
4478 environment from block zero's out-of-band data. The
4479 "nand env.oob" command can be used to record this offset.
4480 Currently, CONFIG_ENV_OFFSET_REDUND is not supported when
4481 using CONFIG_ENV_OFFSET_OOB.
4483 - CONFIG_NAND_ENV_DST
4485 Defines address in RAM to which the nand_spl code should copy the
4486 environment. If redundant environment is used, it will be copied to
4487 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE.
4489 - CONFIG_ENV_IS_IN_UBI:
4491 Define this if you have an UBI volume that you want to use for the
4492 environment. This has the benefit of wear-leveling the environment
4493 accesses, which is important on NAND.
4495 - CONFIG_ENV_UBI_PART:
4497 Define this to a string that is the mtd partition containing the UBI.
4499 - CONFIG_ENV_UBI_VOLUME:
4501 Define this to the name of the volume that you want to store the
4504 - CONFIG_ENV_UBI_VOLUME_REDUND:
4506 Define this to the name of another volume to store a second copy of
4507 the environment in. This will enable redundant environments in UBI.
4508 It is assumed that both volumes are in the same MTD partition.
4510 - CONFIG_UBI_SILENCE_MSG
4511 - CONFIG_UBIFS_SILENCE_MSG
4513 You will probably want to define these to avoid a really noisy system
4514 when storing the env in UBI.
4516 - CONFIG_ENV_IS_IN_FAT:
4517 Define this if you want to use the FAT file system for the environment.
4519 - FAT_ENV_INTERFACE:
4521 Define this to a string that is the name of the block device.
4523 - FAT_ENV_DEV_AND_PART:
4525 Define this to a string to specify the partition of the device. It can
4528 "D:P", "D:0", "D", "D:" or "D:auto" (D, P are integers. And P >= 1)
4529 - "D:P": device D partition P. Error occurs if device D has no
4532 - "D" or "D:": device D partition 1 if device D has partition
4533 table, or the whole device D if has no partition
4535 - "D:auto": first partition in device D with bootable flag set.
4536 If none, first valid partition in device D. If no
4537 partition table then means device D.
4541 It's a string of the FAT file name. This file use to store the
4545 This should be defined. Otherwise it cannot save the environment file.
4547 - CONFIG_ENV_IS_IN_MMC:
4549 Define this if you have an MMC device which you want to use for the
4552 - CONFIG_SYS_MMC_ENV_DEV:
4554 Specifies which MMC device the environment is stored in.
4556 - CONFIG_SYS_MMC_ENV_PART (optional):
4558 Specifies which MMC partition the environment is stored in. If not
4559 set, defaults to partition 0, the user area. Common values might be
4560 1 (first MMC boot partition), 2 (second MMC boot partition).
4562 - CONFIG_ENV_OFFSET:
4565 These two #defines specify the offset and size of the environment
4566 area within the specified MMC device.
4568 If offset is positive (the usual case), it is treated as relative to
4569 the start of the MMC partition. If offset is negative, it is treated
4570 as relative to the end of the MMC partition. This can be useful if
4571 your board may be fitted with different MMC devices, which have
4572 different sizes for the MMC partitions, and you always want the
4573 environment placed at the very end of the partition, to leave the
4574 maximum possible space before it, to store other data.
4576 These two values are in units of bytes, but must be aligned to an
4577 MMC sector boundary.
4579 - CONFIG_ENV_OFFSET_REDUND (optional):
4581 Specifies a second storage area, of CONFIG_ENV_SIZE size, used to
4582 hold a redundant copy of the environment data. This provides a
4583 valid backup copy in case the other copy is corrupted, e.g. due
4584 to a power failure during a "saveenv" operation.
4586 This value may also be positive or negative; this is handled in the
4587 same way as CONFIG_ENV_OFFSET.
4589 This value is also in units of bytes, but must also be aligned to
4590 an MMC sector boundary.
4592 - CONFIG_ENV_SIZE_REDUND (optional):
4594 This value need not be set, even when CONFIG_ENV_OFFSET_REDUND is
4595 set. If this value is set, it must be set to the same value as
4598 - CONFIG_SYS_SPI_INIT_OFFSET
4600 Defines offset to the initial SPI buffer area in DPRAM. The
4601 area is used at an early stage (ROM part) if the environment
4602 is configured to reside in the SPI EEPROM: We need a 520 byte
4603 scratch DPRAM area. It is used between the two initialization
4604 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems
4605 to be a good choice since it makes it far enough from the
4606 start of the data area as well as from the stack pointer.
4608 Please note that the environment is read-only until the monitor
4609 has been relocated to RAM and a RAM copy of the environment has been
4610 created; also, when using EEPROM you will have to use getenv_f()
4611 until then to read environment variables.
4613 The environment is protected by a CRC32 checksum. Before the monitor
4614 is relocated into RAM, as a result of a bad CRC you will be working
4615 with the compiled-in default environment - *silently*!!! [This is
4616 necessary, because the first environment variable we need is the
4617 "baudrate" setting for the console - if we have a bad CRC, we don't
4618 have any device yet where we could complain.]
4620 Note: once the monitor has been relocated, then it will complain if
4621 the default environment is used; a new CRC is computed as soon as you
4622 use the "saveenv" command to store a valid environment.
4624 - CONFIG_SYS_FAULT_ECHO_LINK_DOWN:
4625 Echo the inverted Ethernet link state to the fault LED.
4627 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR
4628 also needs to be defined.
4630 - CONFIG_SYS_FAULT_MII_ADDR:
4631 MII address of the PHY to check for the Ethernet link state.
4633 - CONFIG_NS16550_MIN_FUNCTIONS:
4634 Define this if you desire to only have use of the NS16550_init
4635 and NS16550_putc functions for the serial driver located at
4636 drivers/serial/ns16550.c. This option is useful for saving
4637 space for already greatly restricted images, including but not
4638 limited to NAND_SPL configurations.
4640 - CONFIG_DISPLAY_BOARDINFO
4641 Display information about the board that U-Boot is running on
4642 when U-Boot starts up. The board function checkboard() is called
4645 - CONFIG_DISPLAY_BOARDINFO_LATE
4646 Similar to the previous option, but display this information
4647 later, once stdio is running and output goes to the LCD, if
4650 - CONFIG_BOARD_SIZE_LIMIT:
4651 Maximum size of the U-Boot image. When defined, the
4652 build system checks that the actual size does not
4655 Low Level (hardware related) configuration options:
4656 ---------------------------------------------------
4658 - CONFIG_SYS_CACHELINE_SIZE:
4659 Cache Line Size of the CPU.
4661 - CONFIG_SYS_DEFAULT_IMMR:
4662 Default address of the IMMR after system reset.
4664 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU,
4665 and RPXsuper) to be able to adjust the position of
4666 the IMMR register after a reset.
4668 - CONFIG_SYS_CCSRBAR_DEFAULT:
4669 Default (power-on reset) physical address of CCSR on Freescale
4672 - CONFIG_SYS_CCSRBAR:
4673 Virtual address of CCSR. On a 32-bit build, this is typically
4674 the same value as CONFIG_SYS_CCSRBAR_DEFAULT.
4676 CONFIG_SYS_DEFAULT_IMMR must also be set to this value,
4677 for cross-platform code that uses that macro instead.
4679 - CONFIG_SYS_CCSRBAR_PHYS:
4680 Physical address of CCSR. CCSR can be relocated to a new
4681 physical address, if desired. In this case, this macro should
4682 be set to that address. Otherwise, it should be set to the
4683 same value as CONFIG_SYS_CCSRBAR_DEFAULT. For example, CCSR
4684 is typically relocated on 36-bit builds. It is recommended
4685 that this macro be defined via the _HIGH and _LOW macros:
4687 #define CONFIG_SYS_CCSRBAR_PHYS ((CONFIG_SYS_CCSRBAR_PHYS_HIGH
4688 * 1ull) << 32 | CONFIG_SYS_CCSRBAR_PHYS_LOW)
4690 - CONFIG_SYS_CCSRBAR_PHYS_HIGH:
4691 Bits 33-36 of CONFIG_SYS_CCSRBAR_PHYS. This value is typically
4692 either 0 (32-bit build) or 0xF (36-bit build). This macro is
4693 used in assembly code, so it must not contain typecasts or
4694 integer size suffixes (e.g. "ULL").
4696 - CONFIG_SYS_CCSRBAR_PHYS_LOW:
4697 Lower 32-bits of CONFIG_SYS_CCSRBAR_PHYS. This macro is
4698 used in assembly code, so it must not contain typecasts or
4699 integer size suffixes (e.g. "ULL").
4701 - CONFIG_SYS_CCSR_DO_NOT_RELOCATE:
4702 If this macro is defined, then CONFIG_SYS_CCSRBAR_PHYS will be
4703 forced to a value that ensures that CCSR is not relocated.
4705 - Floppy Disk Support:
4706 CONFIG_SYS_FDC_DRIVE_NUMBER
4708 the default drive number (default value 0)
4710 CONFIG_SYS_ISA_IO_STRIDE
4712 defines the spacing between FDC chipset registers
4715 CONFIG_SYS_ISA_IO_OFFSET
4717 defines the offset of register from address. It
4718 depends on which part of the data bus is connected to
4719 the FDC chipset. (default value 0)
4721 If CONFIG_SYS_ISA_IO_STRIDE CONFIG_SYS_ISA_IO_OFFSET and
4722 CONFIG_SYS_FDC_DRIVE_NUMBER are undefined, they take their
4725 if CONFIG_SYS_FDC_HW_INIT is defined, then the function
4726 fdc_hw_init() is called at the beginning of the FDC
4727 setup. fdc_hw_init() must be provided by the board
4728 source code. It is used to make hardware-dependent
4732 Most IDE controllers were designed to be connected with PCI
4733 interface. Only few of them were designed for AHB interface.
4734 When software is doing ATA command and data transfer to
4735 IDE devices through IDE-AHB controller, some additional
4736 registers accessing to these kind of IDE-AHB controller
4739 - CONFIG_SYS_IMMR: Physical address of the Internal Memory.
4740 DO NOT CHANGE unless you know exactly what you're
4741 doing! (11-4) [MPC8xx/82xx systems only]
4743 - CONFIG_SYS_INIT_RAM_ADDR:
4745 Start address of memory area that can be used for
4746 initial data and stack; please note that this must be
4747 writable memory that is working WITHOUT special
4748 initialization, i. e. you CANNOT use normal RAM which
4749 will become available only after programming the
4750 memory controller and running certain initialization
4753 U-Boot uses the following memory types:
4754 - MPC8xx and MPC8260: IMMR (internal memory of the CPU)
4755 - MPC824X: data cache
4756 - PPC4xx: data cache
4758 - CONFIG_SYS_GBL_DATA_OFFSET:
4760 Offset of the initial data structure in the memory
4761 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually
4762 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial
4763 data is located at the end of the available space
4764 (sometimes written as (CONFIG_SYS_INIT_RAM_SIZE -
4765 CONFIG_SYS_INIT_DATA_SIZE), and the initial stack is just
4766 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR +
4767 CONFIG_SYS_GBL_DATA_OFFSET) downward.
4770 On the MPC824X (or other systems that use the data
4771 cache for initial memory) the address chosen for
4772 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must
4773 point to an otherwise UNUSED address space between
4774 the top of RAM and the start of the PCI space.
4776 - CONFIG_SYS_SIUMCR: SIU Module Configuration (11-6)
4778 - CONFIG_SYS_SYPCR: System Protection Control (11-9)
4780 - CONFIG_SYS_TBSCR: Time Base Status and Control (11-26)
4782 - CONFIG_SYS_PISCR: Periodic Interrupt Status and Control (11-31)
4784 - CONFIG_SYS_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30)
4786 - CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27)
4788 - CONFIG_SYS_OR_TIMING_SDRAM:
4791 - CONFIG_SYS_MAMR_PTA:
4792 periodic timer for refresh
4794 - CONFIG_SYS_DER: Debug Event Register (37-47)
4796 - FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM,
4797 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP,
4798 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM,
4799 CONFIG_SYS_BR1_PRELIM:
4800 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
4802 - SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
4803 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM,
4804 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM:
4805 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
4807 - CONFIG_SYS_MAMR_PTA, CONFIG_SYS_MPTPR_2BK_4K, CONFIG_SYS_MPTPR_1BK_4K, CONFIG_SYS_MPTPR_2BK_8K,
4808 CONFIG_SYS_MPTPR_1BK_8K, CONFIG_SYS_MAMR_8COL, CONFIG_SYS_MAMR_9COL:
4809 Machine Mode Register and Memory Periodic Timer
4810 Prescaler definitions (SDRAM timing)
4812 - CONFIG_SYS_I2C_UCODE_PATCH, CONFIG_SYS_I2C_DPMEM_OFFSET [0x1FC0]:
4813 enable I2C microcode relocation patch (MPC8xx);
4814 define relocation offset in DPRAM [DSP2]
4816 - CONFIG_SYS_SMC_UCODE_PATCH, CONFIG_SYS_SMC_DPMEM_OFFSET [0x1FC0]:
4817 enable SMC microcode relocation patch (MPC8xx);
4818 define relocation offset in DPRAM [SMC1]
4820 - CONFIG_SYS_SPI_UCODE_PATCH, CONFIG_SYS_SPI_DPMEM_OFFSET [0x1FC0]:
4821 enable SPI microcode relocation patch (MPC8xx);
4822 define relocation offset in DPRAM [SCC4]
4824 - CONFIG_SYS_USE_OSCCLK:
4825 Use OSCM clock mode on MBX8xx board. Be careful,
4826 wrong setting might damage your board. Read
4827 doc/README.MBX before setting this variable!
4829 - CONFIG_SYS_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only)
4830 Offset of the bootmode word in DPRAM used by post
4831 (Power On Self Tests). This definition overrides
4832 #define'd default value in commproc.h resp.
4835 - CONFIG_SYS_PCI_SLV_MEM_LOCAL, CONFIG_SYS_PCI_SLV_MEM_BUS, CONFIG_SYS_PICMR0_MASK_ATTRIB,
4836 CONFIG_SYS_PCI_MSTR0_LOCAL, CONFIG_SYS_PCIMSK0_MASK, CONFIG_SYS_PCI_MSTR1_LOCAL,
4837 CONFIG_SYS_PCIMSK1_MASK, CONFIG_SYS_PCI_MSTR_MEM_LOCAL, CONFIG_SYS_PCI_MSTR_MEM_BUS,
4838 CONFIG_SYS_CPU_PCI_MEM_START, CONFIG_SYS_PCI_MSTR_MEM_SIZE, CONFIG_SYS_POCMR0_MASK_ATTRIB,
4839 CONFIG_SYS_PCI_MSTR_MEMIO_LOCAL, CONFIG_SYS_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START,
4840 CONFIG_SYS_PCI_MSTR_MEMIO_SIZE, CONFIG_SYS_POCMR1_MASK_ATTRIB, CONFIG_SYS_PCI_MSTR_IO_LOCAL,
4841 CONFIG_SYS_PCI_MSTR_IO_BUS, CONFIG_SYS_CPU_PCI_IO_START, CONFIG_SYS_PCI_MSTR_IO_SIZE,
4842 CONFIG_SYS_POCMR2_MASK_ATTRIB: (MPC826x only)
4843 Overrides the default PCI memory map in arch/powerpc/cpu/mpc8260/pci.c if set.
4845 - CONFIG_PCI_DISABLE_PCIE:
4846 Disable PCI-Express on systems where it is supported but not
4849 - CONFIG_PCI_ENUM_ONLY
4850 Only scan through and get the devices on the buses.
4851 Don't do any setup work, presumably because someone or
4852 something has already done it, and we don't need to do it
4853 a second time. Useful for platforms that are pre-booted
4854 by coreboot or similar.
4856 - CONFIG_PCI_INDIRECT_BRIDGE:
4857 Enable support for indirect PCI bridges.
4860 Chip has SRIO or not
4863 Board has SRIO 1 port available
4866 Board has SRIO 2 port available
4868 - CONFIG_SRIO_PCIE_BOOT_MASTER
4869 Board can support master function for Boot from SRIO and PCIE
4871 - CONFIG_SYS_SRIOn_MEM_VIRT:
4872 Virtual Address of SRIO port 'n' memory region
4874 - CONFIG_SYS_SRIOn_MEM_PHYS:
4875 Physical Address of SRIO port 'n' memory region
4877 - CONFIG_SYS_SRIOn_MEM_SIZE:
4878 Size of SRIO port 'n' memory region
4880 - CONFIG_SYS_NAND_BUSWIDTH_16BIT
4881 Defined to tell the NAND controller that the NAND chip is using
4883 Not all NAND drivers use this symbol.
4884 Example of drivers that use it:
4885 - drivers/mtd/nand/ndfc.c
4886 - drivers/mtd/nand/mxc_nand.c
4888 - CONFIG_SYS_NDFC_EBC0_CFG
4889 Sets the EBC0_CFG register for the NDFC. If not defined
4890 a default value will be used.
4893 Get DDR timing information from an I2C EEPROM. Common
4894 with pluggable memory modules such as SODIMMs
4897 I2C address of the SPD EEPROM
4899 - CONFIG_SYS_SPD_BUS_NUM
4900 If SPD EEPROM is on an I2C bus other than the first
4901 one, specify here. Note that the value must resolve
4902 to something your driver can deal with.
4904 - CONFIG_SYS_DDR_RAW_TIMING
4905 Get DDR timing information from other than SPD. Common with
4906 soldered DDR chips onboard without SPD. DDR raw timing
4907 parameters are extracted from datasheet and hard-coded into
4908 header files or board specific files.
4910 - CONFIG_FSL_DDR_INTERACTIVE
4911 Enable interactive DDR debugging. See doc/README.fsl-ddr.
4913 - CONFIG_FSL_DDR_SYNC_REFRESH
4914 Enable sync of refresh for multiple controllers.
4916 - CONFIG_SYS_83XX_DDR_USES_CS0
4917 Only for 83xx systems. If specified, then DDR should
4918 be configured using CS0 and CS1 instead of CS2 and CS3.
4920 - CONFIG_ETHER_ON_FEC[12]
4921 Define to enable FEC[12] on a 8xx series processor.
4923 - CONFIG_FEC[12]_PHY
4924 Define to the hardcoded PHY address which corresponds
4925 to the given FEC; i. e.
4926 #define CONFIG_FEC1_PHY 4
4927 means that the PHY with address 4 is connected to FEC1
4929 When set to -1, means to probe for first available.
4931 - CONFIG_FEC[12]_PHY_NORXERR
4932 The PHY does not have a RXERR line (RMII only).
4933 (so program the FEC to ignore it).
4936 Enable RMII mode for all FECs.
4937 Note that this is a global option, we can't
4938 have one FEC in standard MII mode and another in RMII mode.
4940 - CONFIG_CRC32_VERIFY
4941 Add a verify option to the crc32 command.
4944 => crc32 -v <address> <count> <crc32>
4946 Where address/count indicate a memory area
4947 and crc32 is the correct crc32 which the
4951 Add the "loopw" memory command. This only takes effect if
4952 the memory commands are activated globally (CONFIG_CMD_MEM).
4955 Add the "mdc" and "mwc" memory commands. These are cyclic
4960 This command will print 4 bytes (10,11,12,13) each 500 ms.
4962 => mwc.l 100 12345678 10
4963 This command will write 12345678 to address 100 all 10 ms.
4965 This only takes effect if the memory commands are activated
4966 globally (CONFIG_CMD_MEM).
4968 - CONFIG_SKIP_LOWLEVEL_INIT
4969 [ARM, NDS32, MIPS only] If this variable is defined, then certain
4970 low level initializations (like setting up the memory
4971 controller) are omitted and/or U-Boot does not
4972 relocate itself into RAM.
4974 Normally this variable MUST NOT be defined. The only
4975 exception is when U-Boot is loaded (to RAM) by some
4976 other boot loader or by a debugger which performs
4977 these initializations itself.
4980 Modifies the behaviour of start.S when compiling a loader
4981 that is executed before the actual U-Boot. E.g. when
4982 compiling a NAND SPL.
4985 Modifies the behaviour of start.S when compiling a loader
4986 that is executed after the SPL and before the actual U-Boot.
4987 It is loaded by the SPL.
4989 - CONFIG_SYS_MPC85XX_NO_RESETVEC
4990 Only for 85xx systems. If this variable is specified, the section
4991 .resetvec is not kept and the section .bootpg is placed in the
4992 previous 4k of the .text section.
4994 - CONFIG_ARCH_MAP_SYSMEM
4995 Generally U-Boot (and in particular the md command) uses
4996 effective address. It is therefore not necessary to regard
4997 U-Boot address as virtual addresses that need to be translated
4998 to physical addresses. However, sandbox requires this, since
4999 it maintains its own little RAM buffer which contains all
5000 addressable memory. This option causes some memory accesses
5001 to be mapped through map_sysmem() / unmap_sysmem().
5003 - CONFIG_USE_ARCH_MEMCPY
5004 CONFIG_USE_ARCH_MEMSET
5005 If these options are used a optimized version of memcpy/memset will
5006 be used if available. These functions may be faster under some
5007 conditions but may increase the binary size.
5009 - CONFIG_X86_RESET_VECTOR
5010 If defined, the x86 reset vector code is included. This is not
5011 needed when U-Boot is running from Coreboot.
5014 Defines the MPU clock speed (in MHz).
5016 NOTE : currently only supported on AM335x platforms.
5018 - CONFIG_SPL_AM33XX_ENABLE_RTC32K_OSC:
5019 Enables the RTC32K OSC on AM33xx based plattforms
5021 - CONFIG_SYS_NAND_NO_SUBPAGE_WRITE
5022 Option to disable subpage write in NAND driver
5023 driver that uses this:
5024 drivers/mtd/nand/davinci_nand.c
5026 Freescale QE/FMAN Firmware Support:
5027 -----------------------------------
5029 The Freescale QUICCEngine (QE) and Frame Manager (FMAN) both support the
5030 loading of "firmware", which is encoded in the QE firmware binary format.
5031 This firmware often needs to be loaded during U-Boot booting, so macros
5032 are used to identify the storage device (NOR flash, SPI, etc) and the address
5035 - CONFIG_SYS_FMAN_FW_ADDR
5036 The address in the storage device where the FMAN microcode is located. The
5037 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
5040 - CONFIG_SYS_QE_FW_ADDR
5041 The address in the storage device where the QE microcode is located. The
5042 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
5045 - CONFIG_SYS_QE_FMAN_FW_LENGTH
5046 The maximum possible size of the firmware. The firmware binary format
5047 has a field that specifies the actual size of the firmware, but it
5048 might not be possible to read any part of the firmware unless some
5049 local storage is allocated to hold the entire firmware first.
5051 - CONFIG_SYS_QE_FMAN_FW_IN_NOR
5052 Specifies that QE/FMAN firmware is located in NOR flash, mapped as
5053 normal addressable memory via the LBC. CONFIG_SYS_FMAN_FW_ADDR is the
5054 virtual address in NOR flash.
5056 - CONFIG_SYS_QE_FMAN_FW_IN_NAND
5057 Specifies that QE/FMAN firmware is located in NAND flash.
5058 CONFIG_SYS_FMAN_FW_ADDR is the offset within NAND flash.
5060 - CONFIG_SYS_QE_FMAN_FW_IN_MMC
5061 Specifies that QE/FMAN firmware is located on the primary SD/MMC
5062 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
5064 - CONFIG_SYS_QE_FMAN_FW_IN_SPIFLASH
5065 Specifies that QE/FMAN firmware is located on the primary SPI
5066 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
5068 - CONFIG_SYS_QE_FMAN_FW_IN_REMOTE
5069 Specifies that QE/FMAN firmware is located in the remote (master)
5070 memory space. CONFIG_SYS_FMAN_FW_ADDR is a virtual address which
5071 can be mapped from slave TLB->slave LAW->slave SRIO or PCIE outbound
5072 window->master inbound window->master LAW->the ucode address in
5073 master's memory space.
5075 Freescale Layerscape Management Complex Firmware Support:
5076 ---------------------------------------------------------
5077 The Freescale Layerscape Management Complex (MC) supports the loading of
5079 This firmware often needs to be loaded during U-Boot booting, so macros
5080 are used to identify the storage device (NOR flash, SPI, etc) and the address
5083 - CONFIG_FSL_MC_ENET
5084 Enable the MC driver for Layerscape SoCs.
5086 - CONFIG_SYS_LS_MC_FW_ADDR
5087 The address in the storage device where the firmware is located. The
5088 meaning of this address depends on which CONFIG_SYS_LS_MC_FW_IN_xxx macro
5091 - CONFIG_SYS_LS_MC_FW_LENGTH
5092 The maximum possible size of the firmware. The firmware binary format
5093 has a field that specifies the actual size of the firmware, but it
5094 might not be possible to read any part of the firmware unless some
5095 local storage is allocated to hold the entire firmware first.
5097 - CONFIG_SYS_LS_MC_FW_IN_NOR
5098 Specifies that MC firmware is located in NOR flash, mapped as
5099 normal addressable memory via the LBC. CONFIG_SYS_LS_MC_FW_ADDR is the
5100 virtual address in NOR flash.
5102 Building the Software:
5103 ======================
5105 Building U-Boot has been tested in several native build environments
5106 and in many different cross environments. Of course we cannot support
5107 all possibly existing versions of cross development tools in all
5108 (potentially obsolete) versions. In case of tool chain problems we
5109 recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK)
5110 which is extensively used to build and test U-Boot.
5112 If you are not using a native environment, it is assumed that you
5113 have GNU cross compiling tools available in your path. In this case,
5114 you must set the environment variable CROSS_COMPILE in your shell.
5115 Note that no changes to the Makefile or any other source files are
5116 necessary. For example using the ELDK on a 4xx CPU, please enter:
5118 $ CROSS_COMPILE=ppc_4xx-
5119 $ export CROSS_COMPILE
5121 Note: If you wish to generate Windows versions of the utilities in
5122 the tools directory you can use the MinGW toolchain
5123 (http://www.mingw.org). Set your HOST tools to the MinGW
5124 toolchain and execute 'make tools'. For example:
5126 $ make HOSTCC=i586-mingw32msvc-gcc HOSTSTRIP=i586-mingw32msvc-strip tools
5128 Binaries such as tools/mkimage.exe will be created which can
5129 be executed on computers running Windows.
5131 U-Boot is intended to be simple to build. After installing the
5132 sources you must configure U-Boot for one specific board type. This
5137 where "NAME_defconfig" is the name of one of the existing configu-
5138 rations; see boards.cfg for supported names.
5140 Note: for some board special configuration names may exist; check if
5141 additional information is available from the board vendor; for
5142 instance, the TQM823L systems are available without (standard)
5143 or with LCD support. You can select such additional "features"
5144 when choosing the configuration, i. e.
5146 make TQM823L_defconfig
5147 - will configure for a plain TQM823L, i. e. no LCD support
5149 make TQM823L_LCD_defconfig
5150 - will configure for a TQM823L with U-Boot console on LCD
5155 Finally, type "make all", and you should get some working U-Boot
5156 images ready for download to / installation on your system:
5158 - "u-boot.bin" is a raw binary image
5159 - "u-boot" is an image in ELF binary format
5160 - "u-boot.srec" is in Motorola S-Record format
5162 By default the build is performed locally and the objects are saved
5163 in the source directory. One of the two methods can be used to change
5164 this behavior and build U-Boot to some external directory:
5166 1. Add O= to the make command line invocations:
5168 make O=/tmp/build distclean
5169 make O=/tmp/build NAME_defconfig
5170 make O=/tmp/build all
5172 2. Set environment variable KBUILD_OUTPUT to point to the desired location:
5174 export KBUILD_OUTPUT=/tmp/build
5179 Note that the command line "O=" setting overrides the KBUILD_OUTPUT environment
5183 Please be aware that the Makefiles assume you are using GNU make, so
5184 for instance on NetBSD you might need to use "gmake" instead of
5188 If the system board that you have is not listed, then you will need
5189 to port U-Boot to your hardware platform. To do this, follow these
5192 1. Add a new configuration option for your board to the toplevel
5193 "boards.cfg" file, using the existing entries as examples.
5194 Follow the instructions there to keep the boards in order.
5195 2. Create a new directory to hold your board specific code. Add any
5196 files you need. In your board directory, you will need at least
5197 the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds".
5198 3. Create a new configuration file "include/configs/<board>.h" for
5200 3. If you're porting U-Boot to a new CPU, then also create a new
5201 directory to hold your CPU specific code. Add any files you need.
5202 4. Run "make <board>_defconfig" with your new name.
5203 5. Type "make", and you should get a working "u-boot.srec" file
5204 to be installed on your target system.
5205 6. Debug and solve any problems that might arise.
5206 [Of course, this last step is much harder than it sounds.]
5209 Testing of U-Boot Modifications, Ports to New Hardware, etc.:
5210 ==============================================================
5212 If you have modified U-Boot sources (for instance added a new board
5213 or support for new devices, a new CPU, etc.) you are expected to
5214 provide feedback to the other developers. The feedback normally takes
5215 the form of a "patch", i. e. a context diff against a certain (latest
5216 official or latest in the git repository) version of U-Boot sources.
5218 But before you submit such a patch, please verify that your modifi-
5219 cation did not break existing code. At least make sure that *ALL* of
5220 the supported boards compile WITHOUT ANY compiler warnings. To do so,
5221 just run the "MAKEALL" script, which will configure and build U-Boot
5222 for ALL supported system. Be warned, this will take a while. You can
5223 select which (cross) compiler to use by passing a `CROSS_COMPILE'
5224 environment variable to the script, i. e. to use the ELDK cross tools
5227 CROSS_COMPILE=ppc_8xx- MAKEALL
5229 or to build on a native PowerPC system you can type
5231 CROSS_COMPILE=' ' MAKEALL
5233 When using the MAKEALL script, the default behaviour is to build
5234 U-Boot in the source directory. This location can be changed by
5235 setting the BUILD_DIR environment variable. Also, for each target
5236 built, the MAKEALL script saves two log files (<target>.ERR and
5237 <target>.MAKEALL) in the <source dir>/LOG directory. This default
5238 location can be changed by setting the MAKEALL_LOGDIR environment
5239 variable. For example:
5241 export BUILD_DIR=/tmp/build
5242 export MAKEALL_LOGDIR=/tmp/log
5243 CROSS_COMPILE=ppc_8xx- MAKEALL
5245 With the above settings build objects are saved in the /tmp/build,
5246 log files are saved in the /tmp/log and the source tree remains clean
5247 during the whole build process.
5250 See also "U-Boot Porting Guide" below.
5253 Monitor Commands - Overview:
5254 ============================
5256 go - start application at address 'addr'
5257 run - run commands in an environment variable
5258 bootm - boot application image from memory
5259 bootp - boot image via network using BootP/TFTP protocol
5260 bootz - boot zImage from memory
5261 tftpboot- boot image via network using TFTP protocol
5262 and env variables "ipaddr" and "serverip"
5263 (and eventually "gatewayip")
5264 tftpput - upload a file via network using TFTP protocol
5265 rarpboot- boot image via network using RARP/TFTP protocol
5266 diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
5267 loads - load S-Record file over serial line
5268 loadb - load binary file over serial line (kermit mode)
5270 mm - memory modify (auto-incrementing)
5271 nm - memory modify (constant address)
5272 mw - memory write (fill)
5274 cmp - memory compare
5275 crc32 - checksum calculation
5276 i2c - I2C sub-system
5277 sspi - SPI utility commands
5278 base - print or set address offset
5279 printenv- print environment variables
5280 setenv - set environment variables
5281 saveenv - save environment variables to persistent storage
5282 protect - enable or disable FLASH write protection
5283 erase - erase FLASH memory
5284 flinfo - print FLASH memory information
5285 nand - NAND memory operations (see doc/README.nand)
5286 bdinfo - print Board Info structure
5287 iminfo - print header information for application image
5288 coninfo - print console devices and informations
5289 ide - IDE sub-system
5290 loop - infinite loop on address range
5291 loopw - infinite write loop on address range
5292 mtest - simple RAM test
5293 icache - enable or disable instruction cache
5294 dcache - enable or disable data cache
5295 reset - Perform RESET of the CPU
5296 echo - echo args to console
5297 version - print monitor version
5298 help - print online help
5299 ? - alias for 'help'
5302 Monitor Commands - Detailed Description:
5303 ========================================
5307 For now: just type "help <command>".
5310 Environment Variables:
5311 ======================
5313 U-Boot supports user configuration using Environment Variables which
5314 can be made persistent by saving to Flash memory.
5316 Environment Variables are set using "setenv", printed using
5317 "printenv", and saved to Flash using "saveenv". Using "setenv"
5318 without a value can be used to delete a variable from the
5319 environment. As long as you don't save the environment you are
5320 working with an in-memory copy. In case the Flash area containing the
5321 environment is erased by accident, a default environment is provided.
5323 Some configuration options can be set using Environment Variables.
5325 List of environment variables (most likely not complete):
5327 baudrate - see CONFIG_BAUDRATE
5329 bootdelay - see CONFIG_BOOTDELAY
5331 bootcmd - see CONFIG_BOOTCOMMAND
5333 bootargs - Boot arguments when booting an RTOS image
5335 bootfile - Name of the image to load with TFTP
5337 bootm_low - Memory range available for image processing in the bootm
5338 command can be restricted. This variable is given as
5339 a hexadecimal number and defines lowest address allowed
5340 for use by the bootm command. See also "bootm_size"
5341 environment variable. Address defined by "bootm_low" is
5342 also the base of the initial memory mapping for the Linux
5343 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ and
5346 bootm_mapsize - Size of the initial memory mapping for the Linux kernel.
5347 This variable is given as a hexadecimal number and it
5348 defines the size of the memory region starting at base
5349 address bootm_low that is accessible by the Linux kernel
5350 during early boot. If unset, CONFIG_SYS_BOOTMAPSZ is used
5351 as the default value if it is defined, and bootm_size is
5354 bootm_size - Memory range available for image processing in the bootm
5355 command can be restricted. This variable is given as
5356 a hexadecimal number and defines the size of the region
5357 allowed for use by the bootm command. See also "bootm_low"
5358 environment variable.
5360 updatefile - Location of the software update file on a TFTP server, used
5361 by the automatic software update feature. Please refer to
5362 documentation in doc/README.update for more details.
5364 autoload - if set to "no" (any string beginning with 'n'),
5365 "bootp" will just load perform a lookup of the
5366 configuration from the BOOTP server, but not try to
5367 load any image using TFTP
5369 autostart - if set to "yes", an image loaded using the "bootp",
5370 "rarpboot", "tftpboot" or "diskboot" commands will
5371 be automatically started (by internally calling
5374 If set to "no", a standalone image passed to the
5375 "bootm" command will be copied to the load address
5376 (and eventually uncompressed), but NOT be started.
5377 This can be used to load and uncompress arbitrary
5380 fdt_high - if set this restricts the maximum address that the
5381 flattened device tree will be copied into upon boot.
5382 For example, if you have a system with 1 GB memory
5383 at physical address 0x10000000, while Linux kernel
5384 only recognizes the first 704 MB as low memory, you
5385 may need to set fdt_high as 0x3C000000 to have the
5386 device tree blob be copied to the maximum address
5387 of the 704 MB low memory, so that Linux kernel can
5388 access it during the boot procedure.
5390 If this is set to the special value 0xFFFFFFFF then
5391 the fdt will not be copied at all on boot. For this
5392 to work it must reside in writable memory, have
5393 sufficient padding on the end of it for u-boot to
5394 add the information it needs into it, and the memory
5395 must be accessible by the kernel.
5397 fdtcontroladdr- if set this is the address of the control flattened
5398 device tree used by U-Boot when CONFIG_OF_CONTROL is
5401 i2cfast - (PPC405GP|PPC405EP only)
5402 if set to 'y' configures Linux I2C driver for fast
5403 mode (400kHZ). This environment variable is used in
5404 initialization code. So, for changes to be effective
5405 it must be saved and board must be reset.
5407 initrd_high - restrict positioning of initrd images:
5408 If this variable is not set, initrd images will be
5409 copied to the highest possible address in RAM; this
5410 is usually what you want since it allows for
5411 maximum initrd size. If for some reason you want to
5412 make sure that the initrd image is loaded below the
5413 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment
5414 variable to a value of "no" or "off" or "0".
5415 Alternatively, you can set it to a maximum upper
5416 address to use (U-Boot will still check that it
5417 does not overwrite the U-Boot stack and data).
5419 For instance, when you have a system with 16 MB
5420 RAM, and want to reserve 4 MB from use by Linux,
5421 you can do this by adding "mem=12M" to the value of
5422 the "bootargs" variable. However, now you must make
5423 sure that the initrd image is placed in the first
5424 12 MB as well - this can be done with
5426 setenv initrd_high 00c00000
5428 If you set initrd_high to 0xFFFFFFFF, this is an
5429 indication to U-Boot that all addresses are legal
5430 for the Linux kernel, including addresses in flash
5431 memory. In this case U-Boot will NOT COPY the
5432 ramdisk at all. This may be useful to reduce the
5433 boot time on your system, but requires that this
5434 feature is supported by your Linux kernel.
5436 ipaddr - IP address; needed for tftpboot command
5438 loadaddr - Default load address for commands like "bootp",
5439 "rarpboot", "tftpboot", "loadb" or "diskboot"
5441 loads_echo - see CONFIG_LOADS_ECHO
5443 serverip - TFTP server IP address; needed for tftpboot command
5445 bootretry - see CONFIG_BOOT_RETRY_TIME
5447 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
5449 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
5451 ethprime - controls which interface is used first.
5453 ethact - controls which interface is currently active.
5454 For example you can do the following
5456 => setenv ethact FEC
5457 => ping 192.168.0.1 # traffic sent on FEC
5458 => setenv ethact SCC
5459 => ping 10.0.0.1 # traffic sent on SCC
5461 ethrotate - When set to "no" U-Boot does not go through all
5462 available network interfaces.
5463 It just stays at the currently selected interface.
5465 netretry - When set to "no" each network operation will
5466 either succeed or fail without retrying.
5467 When set to "once" the network operation will
5468 fail when all the available network interfaces
5469 are tried once without success.
5470 Useful on scripts which control the retry operation
5473 npe_ucode - set load address for the NPE microcode
5475 silent_linux - If set then Linux will be told to boot silently, by
5476 changing the console to be empty. If "yes" it will be
5477 made silent. If "no" it will not be made silent. If
5478 unset, then it will be made silent if the U-Boot console
5481 tftpsrcport - If this is set, the value is used for TFTP's
5484 tftpdstport - If this is set, the value is used for TFTP's UDP
5485 destination port instead of the Well Know Port 69.
5487 tftpblocksize - Block size to use for TFTP transfers; if not set,
5488 we use the TFTP server's default block size
5490 tftptimeout - Retransmission timeout for TFTP packets (in milli-
5491 seconds, minimum value is 1000 = 1 second). Defines
5492 when a packet is considered to be lost so it has to
5493 be retransmitted. The default is 5000 = 5 seconds.
5494 Lowering this value may make downloads succeed
5495 faster in networks with high packet loss rates or
5496 with unreliable TFTP servers.
5498 vlan - When set to a value < 4095 the traffic over
5499 Ethernet is encapsulated/received over 802.1q
5502 The following image location variables contain the location of images
5503 used in booting. The "Image" column gives the role of the image and is
5504 not an environment variable name. The other columns are environment
5505 variable names. "File Name" gives the name of the file on a TFTP
5506 server, "RAM Address" gives the location in RAM the image will be
5507 loaded to, and "Flash Location" gives the image's address in NOR
5508 flash or offset in NAND flash.
5510 *Note* - these variables don't have to be defined for all boards, some
5511 boards currenlty use other variables for these purposes, and some
5512 boards use these variables for other purposes.
5514 Image File Name RAM Address Flash Location
5515 ----- --------- ----------- --------------
5516 u-boot u-boot u-boot_addr_r u-boot_addr
5517 Linux kernel bootfile kernel_addr_r kernel_addr
5518 device tree blob fdtfile fdt_addr_r fdt_addr
5519 ramdisk ramdiskfile ramdisk_addr_r ramdisk_addr
5521 The following environment variables may be used and automatically
5522 updated by the network boot commands ("bootp" and "rarpboot"),
5523 depending the information provided by your boot server:
5525 bootfile - see above
5526 dnsip - IP address of your Domain Name Server
5527 dnsip2 - IP address of your secondary Domain Name Server
5528 gatewayip - IP address of the Gateway (Router) to use
5529 hostname - Target hostname
5531 netmask - Subnet Mask
5532 rootpath - Pathname of the root filesystem on the NFS server
5533 serverip - see above
5536 There are two special Environment Variables:
5538 serial# - contains hardware identification information such
5539 as type string and/or serial number
5540 ethaddr - Ethernet address
5542 These variables can be set only once (usually during manufacturing of
5543 the board). U-Boot refuses to delete or overwrite these variables
5544 once they have been set once.
5547 Further special Environment Variables:
5549 ver - Contains the U-Boot version string as printed
5550 with the "version" command. This variable is
5551 readonly (see CONFIG_VERSION_VARIABLE).
5554 Please note that changes to some configuration parameters may take
5555 only effect after the next boot (yes, that's just like Windoze :-).
5558 Callback functions for environment variables:
5559 ---------------------------------------------
5561 For some environment variables, the behavior of u-boot needs to change
5562 when their values are changed. This functionality allows functions to
5563 be associated with arbitrary variables. On creation, overwrite, or
5564 deletion, the callback will provide the opportunity for some side
5565 effect to happen or for the change to be rejected.
5567 The callbacks are named and associated with a function using the
5568 U_BOOT_ENV_CALLBACK macro in your board or driver code.
5570 These callbacks are associated with variables in one of two ways. The
5571 static list can be added to by defining CONFIG_ENV_CALLBACK_LIST_STATIC
5572 in the board configuration to a string that defines a list of
5573 associations. The list must be in the following format:
5575 entry = variable_name[:callback_name]
5578 If the callback name is not specified, then the callback is deleted.
5579 Spaces are also allowed anywhere in the list.
5581 Callbacks can also be associated by defining the ".callbacks" variable
5582 with the same list format above. Any association in ".callbacks" will
5583 override any association in the static list. You can define
5584 CONFIG_ENV_CALLBACK_LIST_DEFAULT to a list (string) to define the
5585 ".callbacks" environment variable in the default or embedded environment.
5588 Command Line Parsing:
5589 =====================
5591 There are two different command line parsers available with U-Boot:
5592 the old "simple" one, and the much more powerful "hush" shell:
5594 Old, simple command line parser:
5595 --------------------------------
5597 - supports environment variables (through setenv / saveenv commands)
5598 - several commands on one line, separated by ';'
5599 - variable substitution using "... ${name} ..." syntax
5600 - special characters ('$', ';') can be escaped by prefixing with '\',
5602 setenv bootcmd bootm \${address}
5603 - You can also escape text by enclosing in single apostrophes, for example:
5604 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
5609 - similar to Bourne shell, with control structures like
5610 if...then...else...fi, for...do...done; while...do...done,
5611 until...do...done, ...
5612 - supports environment ("global") variables (through setenv / saveenv
5613 commands) and local shell variables (through standard shell syntax
5614 "name=value"); only environment variables can be used with "run"
5620 (1) If a command line (or an environment variable executed by a "run"
5621 command) contains several commands separated by semicolon, and
5622 one of these commands fails, then the remaining commands will be
5625 (2) If you execute several variables with one call to run (i. e.
5626 calling run with a list of variables as arguments), any failing
5627 command will cause "run" to terminate, i. e. the remaining
5628 variables are not executed.
5630 Note for Redundant Ethernet Interfaces:
5631 =======================================
5633 Some boards come with redundant Ethernet interfaces; U-Boot supports
5634 such configurations and is capable of automatic selection of a
5635 "working" interface when needed. MAC assignment works as follows:
5637 Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
5638 MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
5639 "eth1addr" (=>eth1), "eth2addr", ...
5641 If the network interface stores some valid MAC address (for instance
5642 in SROM), this is used as default address if there is NO correspon-
5643 ding setting in the environment; if the corresponding environment
5644 variable is set, this overrides the settings in the card; that means:
5646 o If the SROM has a valid MAC address, and there is no address in the
5647 environment, the SROM's address is used.
5649 o If there is no valid address in the SROM, and a definition in the
5650 environment exists, then the value from the environment variable is
5653 o If both the SROM and the environment contain a MAC address, and
5654 both addresses are the same, this MAC address is used.
5656 o If both the SROM and the environment contain a MAC address, and the
5657 addresses differ, the value from the environment is used and a
5660 o If neither SROM nor the environment contain a MAC address, an error
5663 If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses
5664 will be programmed into hardware as part of the initialization process. This
5665 may be skipped by setting the appropriate 'ethmacskip' environment variable.
5666 The naming convention is as follows:
5667 "ethmacskip" (=>eth0), "eth1macskip" (=>eth1) etc.
5672 U-Boot is capable of booting (and performing other auxiliary operations on)
5673 images in two formats:
5675 New uImage format (FIT)
5676 -----------------------
5678 Flexible and powerful format based on Flattened Image Tree -- FIT (similar
5679 to Flattened Device Tree). It allows the use of images with multiple
5680 components (several kernels, ramdisks, etc.), with contents protected by
5681 SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory.
5687 Old image format is based on binary files which can be basically anything,
5688 preceded by a special header; see the definitions in include/image.h for
5689 details; basically, the header defines the following image properties:
5691 * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
5692 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
5693 LynxOS, pSOS, QNX, RTEMS, INTEGRITY;
5694 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS,
5696 * Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86,
5697 IA64, MIPS, NDS32, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
5698 Currently supported: ARM, AVR32, Intel x86, MIPS, NDS32, Nios II, PowerPC).
5699 * Compression Type (uncompressed, gzip, bzip2)
5705 The header is marked by a special Magic Number, and both the header
5706 and the data portions of the image are secured against corruption by
5713 Although U-Boot should support any OS or standalone application
5714 easily, the main focus has always been on Linux during the design of
5717 U-Boot includes many features that so far have been part of some
5718 special "boot loader" code within the Linux kernel. Also, any
5719 "initrd" images to be used are no longer part of one big Linux image;
5720 instead, kernel and "initrd" are separate images. This implementation
5721 serves several purposes:
5723 - the same features can be used for other OS or standalone
5724 applications (for instance: using compressed images to reduce the
5725 Flash memory footprint)
5727 - it becomes much easier to port new Linux kernel versions because
5728 lots of low-level, hardware dependent stuff are done by U-Boot
5730 - the same Linux kernel image can now be used with different "initrd"
5731 images; of course this also means that different kernel images can
5732 be run with the same "initrd". This makes testing easier (you don't
5733 have to build a new "zImage.initrd" Linux image when you just
5734 change a file in your "initrd"). Also, a field-upgrade of the
5735 software is easier now.
5741 Porting Linux to U-Boot based systems:
5742 ---------------------------------------
5744 U-Boot cannot save you from doing all the necessary modifications to
5745 configure the Linux device drivers for use with your target hardware
5746 (no, we don't intend to provide a full virtual machine interface to
5749 But now you can ignore ALL boot loader code (in arch/powerpc/mbxboot).
5751 Just make sure your machine specific header file (for instance
5752 include/asm-ppc/tqm8xx.h) includes the same definition of the Board
5753 Information structure as we define in include/asm-<arch>/u-boot.h,
5754 and make sure that your definition of IMAP_ADDR uses the same value
5755 as your U-Boot configuration in CONFIG_SYS_IMMR.
5757 Note that U-Boot now has a driver model, a unified model for drivers.
5758 If you are adding a new driver, plumb it into driver model. If there
5759 is no uclass available, you are encouraged to create one. See
5763 Configuring the Linux kernel:
5764 -----------------------------
5766 No specific requirements for U-Boot. Make sure you have some root
5767 device (initial ramdisk, NFS) for your target system.
5770 Building a Linux Image:
5771 -----------------------
5773 With U-Boot, "normal" build targets like "zImage" or "bzImage" are
5774 not used. If you use recent kernel source, a new build target
5775 "uImage" will exist which automatically builds an image usable by
5776 U-Boot. Most older kernels also have support for a "pImage" target,
5777 which was introduced for our predecessor project PPCBoot and uses a
5778 100% compatible format.
5782 make TQM850L_defconfig
5787 The "uImage" build target uses a special tool (in 'tools/mkimage') to
5788 encapsulate a compressed Linux kernel image with header information,
5789 CRC32 checksum etc. for use with U-Boot. This is what we are doing:
5791 * build a standard "vmlinux" kernel image (in ELF binary format):
5793 * convert the kernel into a raw binary image:
5795 ${CROSS_COMPILE}-objcopy -O binary \
5796 -R .note -R .comment \
5797 -S vmlinux linux.bin
5799 * compress the binary image:
5803 * package compressed binary image for U-Boot:
5805 mkimage -A ppc -O linux -T kernel -C gzip \
5806 -a 0 -e 0 -n "Linux Kernel Image" \
5807 -d linux.bin.gz uImage
5810 The "mkimage" tool can also be used to create ramdisk images for use
5811 with U-Boot, either separated from the Linux kernel image, or
5812 combined into one file. "mkimage" encapsulates the images with a 64
5813 byte header containing information about target architecture,
5814 operating system, image type, compression method, entry points, time
5815 stamp, CRC32 checksums, etc.
5817 "mkimage" can be called in two ways: to verify existing images and
5818 print the header information, or to build new images.
5820 In the first form (with "-l" option) mkimage lists the information
5821 contained in the header of an existing U-Boot image; this includes
5822 checksum verification:
5824 tools/mkimage -l image
5825 -l ==> list image header information
5827 The second form (with "-d" option) is used to build a U-Boot image
5828 from a "data file" which is used as image payload:
5830 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
5831 -n name -d data_file image
5832 -A ==> set architecture to 'arch'
5833 -O ==> set operating system to 'os'
5834 -T ==> set image type to 'type'
5835 -C ==> set compression type 'comp'
5836 -a ==> set load address to 'addr' (hex)
5837 -e ==> set entry point to 'ep' (hex)
5838 -n ==> set image name to 'name'
5839 -d ==> use image data from 'datafile'
5841 Right now, all Linux kernels for PowerPC systems use the same load
5842 address (0x00000000), but the entry point address depends on the
5845 - 2.2.x kernels have the entry point at 0x0000000C,
5846 - 2.3.x and later kernels have the entry point at 0x00000000.
5848 So a typical call to build a U-Boot image would read:
5850 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
5851 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
5852 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz \
5853 > examples/uImage.TQM850L
5854 Image Name: 2.4.4 kernel for TQM850L
5855 Created: Wed Jul 19 02:34:59 2000
5856 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5857 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
5858 Load Address: 0x00000000
5859 Entry Point: 0x00000000
5861 To verify the contents of the image (or check for corruption):
5863 -> tools/mkimage -l examples/uImage.TQM850L
5864 Image Name: 2.4.4 kernel for TQM850L
5865 Created: Wed Jul 19 02:34:59 2000
5866 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5867 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
5868 Load Address: 0x00000000
5869 Entry Point: 0x00000000
5871 NOTE: for embedded systems where boot time is critical you can trade
5872 speed for memory and install an UNCOMPRESSED image instead: this
5873 needs more space in Flash, but boots much faster since it does not
5874 need to be uncompressed:
5876 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz
5877 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
5878 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
5879 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux \
5880 > examples/uImage.TQM850L-uncompressed
5881 Image Name: 2.4.4 kernel for TQM850L
5882 Created: Wed Jul 19 02:34:59 2000
5883 Image Type: PowerPC Linux Kernel Image (uncompressed)
5884 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
5885 Load Address: 0x00000000
5886 Entry Point: 0x00000000
5889 Similar you can build U-Boot images from a 'ramdisk.image.gz' file
5890 when your kernel is intended to use an initial ramdisk:
5892 -> tools/mkimage -n 'Simple Ramdisk Image' \
5893 > -A ppc -O linux -T ramdisk -C gzip \
5894 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
5895 Image Name: Simple Ramdisk Image
5896 Created: Wed Jan 12 14:01:50 2000
5897 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5898 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
5899 Load Address: 0x00000000
5900 Entry Point: 0x00000000
5902 The "dumpimage" is a tool to disassemble images built by mkimage. Its "-i"
5903 option performs the converse operation of the mkimage's second form (the "-d"
5904 option). Given an image built by mkimage, the dumpimage extracts a "data file"
5907 tools/dumpimage -i image -T type -p position data_file
5908 -i ==> extract from the 'image' a specific 'data_file'
5909 -T ==> set image type to 'type'
5910 -p ==> 'position' (starting at 0) of the 'data_file' inside the 'image'
5913 Installing a Linux Image:
5914 -------------------------
5916 To downloading a U-Boot image over the serial (console) interface,
5917 you must convert the image to S-Record format:
5919 objcopy -I binary -O srec examples/image examples/image.srec
5921 The 'objcopy' does not understand the information in the U-Boot
5922 image header, so the resulting S-Record file will be relative to
5923 address 0x00000000. To load it to a given address, you need to
5924 specify the target address as 'offset' parameter with the 'loads'
5927 Example: install the image to address 0x40100000 (which on the
5928 TQM8xxL is in the first Flash bank):
5930 => erase 40100000 401FFFFF
5936 ## Ready for S-Record download ...
5937 ~>examples/image.srec
5938 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
5940 15989 15990 15991 15992
5941 [file transfer complete]
5943 ## Start Addr = 0x00000000
5946 You can check the success of the download using the 'iminfo' command;
5947 this includes a checksum verification so you can be sure no data
5948 corruption happened:
5952 ## Checking Image at 40100000 ...
5953 Image Name: 2.2.13 for initrd on TQM850L
5954 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5955 Data Size: 335725 Bytes = 327 kB = 0 MB
5956 Load Address: 00000000
5957 Entry Point: 0000000c
5958 Verifying Checksum ... OK
5964 The "bootm" command is used to boot an application that is stored in
5965 memory (RAM or Flash). In case of a Linux kernel image, the contents
5966 of the "bootargs" environment variable is passed to the kernel as
5967 parameters. You can check and modify this variable using the
5968 "printenv" and "setenv" commands:
5971 => printenv bootargs
5972 bootargs=root=/dev/ram
5974 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5976 => printenv bootargs
5977 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5980 ## Booting Linux kernel at 40020000 ...
5981 Image Name: 2.2.13 for NFS on TQM850L
5982 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5983 Data Size: 381681 Bytes = 372 kB = 0 MB
5984 Load Address: 00000000
5985 Entry Point: 0000000c
5986 Verifying Checksum ... OK
5987 Uncompressing Kernel Image ... OK
5988 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
5989 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5990 time_init: decrementer frequency = 187500000/60
5991 Calibrating delay loop... 49.77 BogoMIPS
5992 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
5995 If you want to boot a Linux kernel with initial RAM disk, you pass
5996 the memory addresses of both the kernel and the initrd image (PPBCOOT
5997 format!) to the "bootm" command:
5999 => imi 40100000 40200000
6001 ## Checking Image at 40100000 ...
6002 Image Name: 2.2.13 for initrd on TQM850L
6003 Image Type: PowerPC Linux Kernel Image (gzip compressed)
6004 Data Size: 335725 Bytes = 327 kB = 0 MB
6005 Load Address: 00000000
6006 Entry Point: 0000000c
6007 Verifying Checksum ... OK
6009 ## Checking Image at 40200000 ...
6010 Image Name: Simple Ramdisk Image
6011 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
6012 Data Size: 566530 Bytes = 553 kB = 0 MB
6013 Load Address: 00000000
6014 Entry Point: 00000000
6015 Verifying Checksum ... OK
6017 => bootm 40100000 40200000
6018 ## Booting Linux kernel at 40100000 ...
6019 Image Name: 2.2.13 for initrd on TQM850L
6020 Image Type: PowerPC Linux Kernel Image (gzip compressed)
6021 Data Size: 335725 Bytes = 327 kB = 0 MB
6022 Load Address: 00000000
6023 Entry Point: 0000000c
6024 Verifying Checksum ... OK
6025 Uncompressing Kernel Image ... OK
6026 ## Loading RAMDisk Image at 40200000 ...
6027 Image Name: Simple Ramdisk Image
6028 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
6029 Data Size: 566530 Bytes = 553 kB = 0 MB
6030 Load Address: 00000000
6031 Entry Point: 00000000
6032 Verifying Checksum ... OK
6033 Loading Ramdisk ... OK
6034 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
6035 Boot arguments: root=/dev/ram
6036 time_init: decrementer frequency = 187500000/60
6037 Calibrating delay loop... 49.77 BogoMIPS
6039 RAMDISK: Compressed image found at block 0
6040 VFS: Mounted root (ext2 filesystem).
6044 Boot Linux and pass a flat device tree:
6047 First, U-Boot must be compiled with the appropriate defines. See the section
6048 titled "Linux Kernel Interface" above for a more in depth explanation. The
6049 following is an example of how to start a kernel and pass an updated
6055 oft=oftrees/mpc8540ads.dtb
6056 => tftp $oftaddr $oft
6057 Speed: 1000, full duplex
6059 TFTP from server 192.168.1.1; our IP address is 192.168.1.101
6060 Filename 'oftrees/mpc8540ads.dtb'.
6061 Load address: 0x300000
6064 Bytes transferred = 4106 (100a hex)
6065 => tftp $loadaddr $bootfile
6066 Speed: 1000, full duplex
6068 TFTP from server 192.168.1.1; our IP address is 192.168.1.2
6070 Load address: 0x200000
6071 Loading:############
6073 Bytes transferred = 1029407 (fb51f hex)
6078 => bootm $loadaddr - $oftaddr
6079 ## Booting image at 00200000 ...
6080 Image Name: Linux-2.6.17-dirty
6081 Image Type: PowerPC Linux Kernel Image (gzip compressed)
6082 Data Size: 1029343 Bytes = 1005.2 kB
6083 Load Address: 00000000
6084 Entry Point: 00000000
6085 Verifying Checksum ... OK
6086 Uncompressing Kernel Image ... OK
6087 Booting using flat device tree at 0x300000
6088 Using MPC85xx ADS machine description
6089 Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb
6093 More About U-Boot Image Types:
6094 ------------------------------
6096 U-Boot supports the following image types:
6098 "Standalone Programs" are directly runnable in the environment
6099 provided by U-Boot; it is expected that (if they behave
6100 well) you can continue to work in U-Boot after return from
6101 the Standalone Program.
6102 "OS Kernel Images" are usually images of some Embedded OS which
6103 will take over control completely. Usually these programs
6104 will install their own set of exception handlers, device
6105 drivers, set up the MMU, etc. - this means, that you cannot
6106 expect to re-enter U-Boot except by resetting the CPU.
6107 "RAMDisk Images" are more or less just data blocks, and their
6108 parameters (address, size) are passed to an OS kernel that is
6110 "Multi-File Images" contain several images, typically an OS
6111 (Linux) kernel image and one or more data images like
6112 RAMDisks. This construct is useful for instance when you want
6113 to boot over the network using BOOTP etc., where the boot
6114 server provides just a single image file, but you want to get
6115 for instance an OS kernel and a RAMDisk image.
6117 "Multi-File Images" start with a list of image sizes, each
6118 image size (in bytes) specified by an "uint32_t" in network
6119 byte order. This list is terminated by an "(uint32_t)0".
6120 Immediately after the terminating 0 follow the images, one by
6121 one, all aligned on "uint32_t" boundaries (size rounded up to
6122 a multiple of 4 bytes).
6124 "Firmware Images" are binary images containing firmware (like
6125 U-Boot or FPGA images) which usually will be programmed to
6128 "Script files" are command sequences that will be executed by
6129 U-Boot's command interpreter; this feature is especially
6130 useful when you configure U-Boot to use a real shell (hush)
6131 as command interpreter.
6133 Booting the Linux zImage:
6134 -------------------------
6136 On some platforms, it's possible to boot Linux zImage. This is done
6137 using the "bootz" command. The syntax of "bootz" command is the same
6138 as the syntax of "bootm" command.
6140 Note, defining the CONFIG_SUPPORT_RAW_INITRD allows user to supply
6141 kernel with raw initrd images. The syntax is slightly different, the
6142 address of the initrd must be augmented by it's size, in the following
6143 format: "<initrd addres>:<initrd size>".
6149 One of the features of U-Boot is that you can dynamically load and
6150 run "standalone" applications, which can use some resources of
6151 U-Boot like console I/O functions or interrupt services.
6153 Two simple examples are included with the sources:
6158 'examples/hello_world.c' contains a small "Hello World" Demo
6159 application; it is automatically compiled when you build U-Boot.
6160 It's configured to run at address 0x00040004, so you can play with it
6164 ## Ready for S-Record download ...
6165 ~>examples/hello_world.srec
6166 1 2 3 4 5 6 7 8 9 10 11 ...
6167 [file transfer complete]
6169 ## Start Addr = 0x00040004
6171 => go 40004 Hello World! This is a test.
6172 ## Starting application at 0x00040004 ...
6183 Hit any key to exit ...
6185 ## Application terminated, rc = 0x0
6187 Another example, which demonstrates how to register a CPM interrupt
6188 handler with the U-Boot code, can be found in 'examples/timer.c'.
6189 Here, a CPM timer is set up to generate an interrupt every second.
6190 The interrupt service routine is trivial, just printing a '.'
6191 character, but this is just a demo program. The application can be
6192 controlled by the following keys:
6194 ? - print current values og the CPM Timer registers
6195 b - enable interrupts and start timer
6196 e - stop timer and disable interrupts
6197 q - quit application
6200 ## Ready for S-Record download ...
6201 ~>examples/timer.srec
6202 1 2 3 4 5 6 7 8 9 10 11 ...
6203 [file transfer complete]
6205 ## Start Addr = 0x00040004
6208 ## Starting application at 0x00040004 ...
6211 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
6214 [q, b, e, ?] Set interval 1000000 us
6217 [q, b, e, ?] ........
6218 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
6221 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
6224 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
6227 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
6229 [q, b, e, ?] ...Stopping timer
6231 [q, b, e, ?] ## Application terminated, rc = 0x0
6237 Over time, many people have reported problems when trying to use the
6238 "minicom" terminal emulation program for serial download. I (wd)
6239 consider minicom to be broken, and recommend not to use it. Under
6240 Unix, I recommend to use C-Kermit for general purpose use (and
6241 especially for kermit binary protocol download ("loadb" command), and
6242 use "cu" for S-Record download ("loads" command). See
6243 http://www.denx.de/wiki/view/DULG/SystemSetup#Section_4.3.
6244 for help with kermit.
6247 Nevertheless, if you absolutely want to use it try adding this
6248 configuration to your "File transfer protocols" section:
6250 Name Program Name U/D FullScr IO-Red. Multi
6251 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
6252 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
6258 Starting at version 0.9.2, U-Boot supports NetBSD both as host
6259 (build U-Boot) and target system (boots NetBSD/mpc8xx).
6261 Building requires a cross environment; it is known to work on
6262 NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
6263 need gmake since the Makefiles are not compatible with BSD make).
6264 Note that the cross-powerpc package does not install include files;
6265 attempting to build U-Boot will fail because <machine/ansi.h> is
6266 missing. This file has to be installed and patched manually:
6268 # cd /usr/pkg/cross/powerpc-netbsd/include
6270 # ln -s powerpc machine
6271 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
6272 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
6274 Native builds *don't* work due to incompatibilities between native
6275 and U-Boot include files.
6277 Booting assumes that (the first part of) the image booted is a
6278 stage-2 loader which in turn loads and then invokes the kernel
6279 proper. Loader sources will eventually appear in the NetBSD source
6280 tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
6281 meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz
6284 Implementation Internals:
6285 =========================
6287 The following is not intended to be a complete description of every
6288 implementation detail. However, it should help to understand the
6289 inner workings of U-Boot and make it easier to port it to custom
6293 Initial Stack, Global Data:
6294 ---------------------------
6296 The implementation of U-Boot is complicated by the fact that U-Boot
6297 starts running out of ROM (flash memory), usually without access to
6298 system RAM (because the memory controller is not initialized yet).
6299 This means that we don't have writable Data or BSS segments, and BSS
6300 is not initialized as zero. To be able to get a C environment working
6301 at all, we have to allocate at least a minimal stack. Implementation
6302 options for this are defined and restricted by the CPU used: Some CPU
6303 models provide on-chip memory (like the IMMR area on MPC8xx and
6304 MPC826x processors), on others (parts of) the data cache can be
6305 locked as (mis-) used as memory, etc.
6307 Chris Hallinan posted a good summary of these issues to the
6308 U-Boot mailing list:
6310 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
6311 From: "Chris Hallinan" <clh@net1plus.com>
6312 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
6315 Correct me if I'm wrong, folks, but the way I understand it
6316 is this: Using DCACHE as initial RAM for Stack, etc, does not
6317 require any physical RAM backing up the cache. The cleverness
6318 is that the cache is being used as a temporary supply of
6319 necessary storage before the SDRAM controller is setup. It's
6320 beyond the scope of this list to explain the details, but you
6321 can see how this works by studying the cache architecture and
6322 operation in the architecture and processor-specific manuals.
6324 OCM is On Chip Memory, which I believe the 405GP has 4K. It
6325 is another option for the system designer to use as an
6326 initial stack/RAM area prior to SDRAM being available. Either
6327 option should work for you. Using CS 4 should be fine if your
6328 board designers haven't used it for something that would
6329 cause you grief during the initial boot! It is frequently not
6332 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere
6333 with your processor/board/system design. The default value
6334 you will find in any recent u-boot distribution in
6335 walnut.h should work for you. I'd set it to a value larger
6336 than your SDRAM module. If you have a 64MB SDRAM module, set
6337 it above 400_0000. Just make sure your board has no resources
6338 that are supposed to respond to that address! That code in
6339 start.S has been around a while and should work as is when
6340 you get the config right.
6345 It is essential to remember this, since it has some impact on the C
6346 code for the initialization procedures:
6348 * Initialized global data (data segment) is read-only. Do not attempt
6351 * Do not use any uninitialized global data (or implicitly initialized
6352 as zero data - BSS segment) at all - this is undefined, initiali-
6353 zation is performed later (when relocating to RAM).
6355 * Stack space is very limited. Avoid big data buffers or things like
6358 Having only the stack as writable memory limits means we cannot use
6359 normal global data to share information between the code. But it
6360 turned out that the implementation of U-Boot can be greatly
6361 simplified by making a global data structure (gd_t) available to all
6362 functions. We could pass a pointer to this data as argument to _all_
6363 functions, but this would bloat the code. Instead we use a feature of
6364 the GCC compiler (Global Register Variables) to share the data: we
6365 place a pointer (gd) to the global data into a register which we
6366 reserve for this purpose.
6368 When choosing a register for such a purpose we are restricted by the
6369 relevant (E)ABI specifications for the current architecture, and by
6370 GCC's implementation.
6372 For PowerPC, the following registers have specific use:
6374 R2: reserved for system use
6375 R3-R4: parameter passing and return values
6376 R5-R10: parameter passing
6377 R13: small data area pointer
6381 (U-Boot also uses R12 as internal GOT pointer. r12
6382 is a volatile register so r12 needs to be reset when
6383 going back and forth between asm and C)
6385 ==> U-Boot will use R2 to hold a pointer to the global data
6387 Note: on PPC, we could use a static initializer (since the
6388 address of the global data structure is known at compile time),
6389 but it turned out that reserving a register results in somewhat
6390 smaller code - although the code savings are not that big (on
6391 average for all boards 752 bytes for the whole U-Boot image,
6392 624 text + 127 data).
6394 On Blackfin, the normal C ABI (except for P3) is followed as documented here:
6395 http://docs.blackfin.uclinux.org/doku.php?id=application_binary_interface
6397 ==> U-Boot will use P3 to hold a pointer to the global data
6399 On ARM, the following registers are used:
6401 R0: function argument word/integer result
6402 R1-R3: function argument word
6403 R9: platform specific
6404 R10: stack limit (used only if stack checking is enabled)
6405 R11: argument (frame) pointer
6406 R12: temporary workspace
6409 R15: program counter
6411 ==> U-Boot will use R9 to hold a pointer to the global data
6413 Note: on ARM, only R_ARM_RELATIVE relocations are supported.
6415 On Nios II, the ABI is documented here:
6416 http://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf
6418 ==> U-Boot will use gp to hold a pointer to the global data
6420 Note: on Nios II, we give "-G0" option to gcc and don't use gp
6421 to access small data sections, so gp is free.
6423 On NDS32, the following registers are used:
6425 R0-R1: argument/return
6427 R15: temporary register for assembler
6428 R16: trampoline register
6429 R28: frame pointer (FP)
6430 R29: global pointer (GP)
6431 R30: link register (LP)
6432 R31: stack pointer (SP)
6433 PC: program counter (PC)
6435 ==> U-Boot will use R10 to hold a pointer to the global data
6437 NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope,
6438 or current versions of GCC may "optimize" the code too much.
6443 U-Boot runs in system state and uses physical addresses, i.e. the
6444 MMU is not used either for address mapping nor for memory protection.
6446 The available memory is mapped to fixed addresses using the memory
6447 controller. In this process, a contiguous block is formed for each
6448 memory type (Flash, SDRAM, SRAM), even when it consists of several
6449 physical memory banks.
6451 U-Boot is installed in the first 128 kB of the first Flash bank (on
6452 TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
6453 booting and sizing and initializing DRAM, the code relocates itself
6454 to the upper end of DRAM. Immediately below the U-Boot code some
6455 memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN
6456 configuration setting]. Below that, a structure with global Board
6457 Info data is placed, followed by the stack (growing downward).
6459 Additionally, some exception handler code is copied to the low 8 kB
6460 of DRAM (0x00000000 ... 0x00001FFF).
6462 So a typical memory configuration with 16 MB of DRAM could look like
6465 0x0000 0000 Exception Vector code
6468 0x0000 2000 Free for Application Use
6474 0x00FB FF20 Monitor Stack (Growing downward)
6475 0x00FB FFAC Board Info Data and permanent copy of global data
6476 0x00FC 0000 Malloc Arena
6479 0x00FE 0000 RAM Copy of Monitor Code
6480 ... eventually: LCD or video framebuffer
6481 ... eventually: pRAM (Protected RAM - unchanged by reset)
6482 0x00FF FFFF [End of RAM]
6485 System Initialization:
6486 ----------------------
6488 In the reset configuration, U-Boot starts at the reset entry point
6489 (on most PowerPC systems at address 0x00000100). Because of the reset
6490 configuration for CS0# this is a mirror of the on board Flash memory.
6491 To be able to re-map memory U-Boot then jumps to its link address.
6492 To be able to implement the initialization code in C, a (small!)
6493 initial stack is set up in the internal Dual Ported RAM (in case CPUs
6494 which provide such a feature like MPC8xx or MPC8260), or in a locked
6495 part of the data cache. After that, U-Boot initializes the CPU core,
6496 the caches and the SIU.
6498 Next, all (potentially) available memory banks are mapped using a
6499 preliminary mapping. For example, we put them on 512 MB boundaries
6500 (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
6501 on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
6502 programmed for SDRAM access. Using the temporary configuration, a
6503 simple memory test is run that determines the size of the SDRAM
6506 When there is more than one SDRAM bank, and the banks are of
6507 different size, the largest is mapped first. For equal size, the first
6508 bank (CS2#) is mapped first. The first mapping is always for address
6509 0x00000000, with any additional banks following immediately to create
6510 contiguous memory starting from 0.
6512 Then, the monitor installs itself at the upper end of the SDRAM area
6513 and allocates memory for use by malloc() and for the global Board
6514 Info data; also, the exception vector code is copied to the low RAM
6515 pages, and the final stack is set up.
6517 Only after this relocation will you have a "normal" C environment;
6518 until that you are restricted in several ways, mostly because you are
6519 running from ROM, and because the code will have to be relocated to a
6523 U-Boot Porting Guide:
6524 ----------------------
6526 [Based on messages by Jerry Van Baren in the U-Boot-Users mailing
6530 int main(int argc, char *argv[])
6532 sighandler_t no_more_time;
6534 signal(SIGALRM, no_more_time);
6535 alarm(PROJECT_DEADLINE - toSec (3 * WEEK));
6537 if (available_money > available_manpower) {
6538 Pay consultant to port U-Boot;
6542 Download latest U-Boot source;
6544 Subscribe to u-boot mailing list;
6547 email("Hi, I am new to U-Boot, how do I get started?");
6550 Read the README file in the top level directory;
6551 Read http://www.denx.de/twiki/bin/view/DULG/Manual;
6552 Read applicable doc/*.README;
6553 Read the source, Luke;
6554 /* find . -name "*.[chS]" | xargs grep -i <keyword> */
6557 if (available_money > toLocalCurrency ($2500))
6560 Add a lot of aggravation and time;
6562 if (a similar board exists) { /* hopefully... */
6563 cp -a board/<similar> board/<myboard>
6564 cp include/configs/<similar>.h include/configs/<myboard>.h
6566 Create your own board support subdirectory;
6567 Create your own board include/configs/<myboard>.h file;
6569 Edit new board/<myboard> files
6570 Edit new include/configs/<myboard>.h
6575 Add / modify source code;
6579 email("Hi, I am having problems...");
6581 Send patch file to the U-Boot email list;
6582 if (reasonable critiques)
6583 Incorporate improvements from email list code review;
6585 Defend code as written;
6591 void no_more_time (int sig)
6600 All contributions to U-Boot should conform to the Linux kernel
6601 coding style; see the file "Documentation/CodingStyle" and the script
6602 "scripts/Lindent" in your Linux kernel source directory.
6604 Source files originating from a different project (for example the
6605 MTD subsystem) are generally exempt from these guidelines and are not
6606 reformatted to ease subsequent migration to newer versions of those
6609 Please note that U-Boot is implemented in C (and to some small parts in
6610 Assembler); no C++ is used, so please do not use C++ style comments (//)
6613 Please also stick to the following formatting rules:
6614 - remove any trailing white space
6615 - use TAB characters for indentation and vertical alignment, not spaces
6616 - make sure NOT to use DOS '\r\n' line feeds
6617 - do not add more than 2 consecutive empty lines to source files
6618 - do not add trailing empty lines to source files
6620 Submissions which do not conform to the standards may be returned
6621 with a request to reformat the changes.
6627 Since the number of patches for U-Boot is growing, we need to
6628 establish some rules. Submissions which do not conform to these rules
6629 may be rejected, even when they contain important and valuable stuff.
6631 Please see http://www.denx.de/wiki/U-Boot/Patches for details.
6633 Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>;
6634 see http://lists.denx.de/mailman/listinfo/u-boot
6636 When you send a patch, please include the following information with
6639 * For bug fixes: a description of the bug and how your patch fixes
6640 this bug. Please try to include a way of demonstrating that the
6641 patch actually fixes something.
6643 * For new features: a description of the feature and your
6646 * A CHANGELOG entry as plaintext (separate from the patch)
6648 * For major contributions, your entry to the CREDITS file
6650 * When you add support for a new board, don't forget to add a
6651 maintainer e-mail address to the boards.cfg file, too.
6653 * If your patch adds new configuration options, don't forget to
6654 document these in the README file.
6656 * The patch itself. If you are using git (which is *strongly*
6657 recommended) you can easily generate the patch using the
6658 "git format-patch". If you then use "git send-email" to send it to
6659 the U-Boot mailing list, you will avoid most of the common problems
6660 with some other mail clients.
6662 If you cannot use git, use "diff -purN OLD NEW". If your version of
6663 diff does not support these options, then get the latest version of
6666 The current directory when running this command shall be the parent
6667 directory of the U-Boot source tree (i. e. please make sure that
6668 your patch includes sufficient directory information for the
6671 We prefer patches as plain text. MIME attachments are discouraged,
6672 and compressed attachments must not be used.
6674 * If one logical set of modifications affects or creates several
6675 files, all these changes shall be submitted in a SINGLE patch file.
6677 * Changesets that contain different, unrelated modifications shall be
6678 submitted as SEPARATE patches, one patch per changeset.
6683 * Before sending the patch, run the MAKEALL script on your patched
6684 source tree and make sure that no errors or warnings are reported
6685 for any of the boards.
6687 * Keep your modifications to the necessary minimum: A patch
6688 containing several unrelated changes or arbitrary reformats will be
6689 returned with a request to re-formatting / split it.
6691 * If you modify existing code, make sure that your new code does not
6692 add to the memory footprint of the code ;-) Small is beautiful!
6693 When adding new features, these should compile conditionally only
6694 (using #ifdef), and the resulting code with the new feature
6695 disabled must not need more memory than the old code without your
6698 * Remember that there is a size limit of 100 kB per message on the
6699 u-boot mailing list. Bigger patches will be moderated. If they are
6700 reasonable and not too big, they will be acknowledged. But patches
6701 bigger than the size limit should be avoided.
projects / karo-tx-uboot.git / blob