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_430973
697 CONFIG_ARM_ERRATA_454179
698 CONFIG_ARM_ERRATA_621766
699 CONFIG_ARM_ERRATA_798870
702 CONFIG_TEGRA_SUPPORT_NON_SECURE
704 Support executing U-Boot in non-secure (NS) mode. Certain
705 impossible actions will be skipped if the CPU is in NS mode,
706 such as ARM architectural timer initialization.
709 - Linux Kernel Interface:
712 U-Boot stores all clock information in Hz
713 internally. For binary compatibility with older Linux
714 kernels (which expect the clocks passed in the
715 bd_info data to be in MHz) the environment variable
716 "clocks_in_mhz" can be defined so that U-Boot
717 converts clock data to MHZ before passing it to the
719 When CONFIG_CLOCKS_IN_MHZ is defined, a definition of
720 "clocks_in_mhz=1" is automatically included in the
723 CONFIG_MEMSIZE_IN_BYTES [relevant for MIPS only]
725 When transferring memsize parameter to Linux, some versions
726 expect it to be in bytes, others in MB.
727 Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes.
731 New kernel versions are expecting firmware settings to be
732 passed using flattened device trees (based on open firmware
736 * New libfdt-based support
737 * Adds the "fdt" command
738 * The bootm command automatically updates the fdt
740 OF_CPU - The proper name of the cpus node (only required for
741 MPC512X and MPC5xxx based boards).
742 OF_SOC - The proper name of the soc node (only required for
743 MPC512X and MPC5xxx based boards).
744 OF_TBCLK - The timebase frequency.
745 OF_STDOUT_PATH - The path to the console device
747 boards with QUICC Engines require OF_QE to set UCC MAC
750 CONFIG_OF_BOARD_SETUP
752 Board code has addition modification that it wants to make
753 to the flat device tree before handing it off to the kernel
755 CONFIG_OF_SYSTEM_SETUP
757 Other code has addition modification that it wants to make
758 to the flat device tree before handing it off to the kernel.
759 This causes ft_system_setup() to be called before booting
764 This define fills in the correct boot CPU in the boot
765 param header, the default value is zero if undefined.
769 U-Boot can detect if an IDE device is present or not.
770 If not, and this new config option is activated, U-Boot
771 removes the ATA node from the DTS before booting Linux,
772 so the Linux IDE driver does not probe the device and
773 crash. This is needed for buggy hardware (uc101) where
774 no pull down resistor is connected to the signal IDE5V_DD7.
776 CONFIG_MACH_TYPE [relevant for ARM only][mandatory]
778 This setting is mandatory for all boards that have only one
779 machine type and must be used to specify the machine type
780 number as it appears in the ARM machine registry
781 (see http://www.arm.linux.org.uk/developer/machines/).
782 Only boards that have multiple machine types supported
783 in a single configuration file and the machine type is
784 runtime discoverable, do not have to use this setting.
786 - vxWorks boot parameters:
788 bootvx constructs a valid bootline using the following
789 environments variables: bootfile, ipaddr, serverip, hostname.
790 It loads the vxWorks image pointed bootfile.
792 CONFIG_SYS_VXWORKS_BOOT_DEVICE - The vxworks device name
793 CONFIG_SYS_VXWORKS_MAC_PTR - Ethernet 6 byte MA -address
794 CONFIG_SYS_VXWORKS_SERVERNAME - Name of the server
795 CONFIG_SYS_VXWORKS_BOOT_ADDR - Address of boot parameters
797 CONFIG_SYS_VXWORKS_ADD_PARAMS
799 Add it at the end of the bootline. E.g "u=username pw=secret"
801 Note: If a "bootargs" environment is defined, it will overwride
802 the defaults discussed just above.
804 - Cache Configuration:
805 CONFIG_SYS_ICACHE_OFF - Do not enable instruction cache in U-Boot
806 CONFIG_SYS_DCACHE_OFF - Do not enable data cache in U-Boot
807 CONFIG_SYS_L2CACHE_OFF- Do not enable L2 cache in U-Boot
809 - Cache Configuration for ARM:
810 CONFIG_SYS_L2_PL310 - Enable support for ARM PL310 L2 cache
812 CONFIG_SYS_PL310_BASE - Physical base address of PL310
813 controller register space
818 Define this if you want support for Amba PrimeCell PL010 UARTs.
822 Define this if you want support for Amba PrimeCell PL011 UARTs.
826 If you have Amba PrimeCell PL011 UARTs, set this variable to
827 the clock speed of the UARTs.
831 If you have Amba PrimeCell PL010 or PL011 UARTs on your board,
832 define this to a list of base addresses for each (supported)
833 port. See e.g. include/configs/versatile.h
835 CONFIG_PL011_SERIAL_RLCR
837 Some vendor versions of PL011 serial ports (e.g. ST-Ericsson U8500)
838 have separate receive and transmit line control registers. Set
839 this variable to initialize the extra register.
841 CONFIG_PL011_SERIAL_FLUSH_ON_INIT
843 On some platforms (e.g. U8500) U-Boot is loaded by a second stage
844 boot loader that has already initialized the UART. Define this
845 variable to flush the UART at init time.
847 CONFIG_SERIAL_HW_FLOW_CONTROL
849 Define this variable to enable hw flow control in serial driver.
850 Current user of this option is drivers/serial/nsl16550.c driver
853 Depending on board, define exactly one serial port
854 (like CONFIG_8xx_CONS_SMC1, CONFIG_8xx_CONS_SMC2,
855 CONFIG_8xx_CONS_SCC1, ...), or switch off the serial
856 console by defining CONFIG_8xx_CONS_NONE
858 Note: if CONFIG_8xx_CONS_NONE is defined, the serial
859 port routines must be defined elsewhere
860 (i.e. serial_init(), serial_getc(), ...)
863 Enables console device for a color framebuffer. Needs following
864 defines (cf. smiLynxEM, i8042)
865 VIDEO_FB_LITTLE_ENDIAN graphic memory organisation
867 VIDEO_HW_RECTFILL graphic chip supports
870 VIDEO_HW_BITBLT graphic chip supports
871 bit-blit (cf. smiLynxEM)
872 VIDEO_VISIBLE_COLS visible pixel columns
874 VIDEO_VISIBLE_ROWS visible pixel rows
875 VIDEO_PIXEL_SIZE bytes per pixel
876 VIDEO_DATA_FORMAT graphic data format
877 (0-5, cf. cfb_console.c)
878 VIDEO_FB_ADRS framebuffer address
879 VIDEO_KBD_INIT_FCT keyboard int fct
880 (i.e. i8042_kbd_init())
881 VIDEO_TSTC_FCT test char fct
883 VIDEO_GETC_FCT get char fct
885 CONFIG_CONSOLE_CURSOR cursor drawing on/off
886 (requires blink timer
888 CONFIG_SYS_CONSOLE_BLINK_COUNT blink interval (cf. i8042.c)
889 CONFIG_CONSOLE_TIME display time/date info in
891 (requires CONFIG_CMD_DATE)
892 CONFIG_VIDEO_LOGO display Linux logo in
894 CONFIG_VIDEO_BMP_LOGO use bmp_logo.h instead of
895 linux_logo.h for logo.
896 Requires CONFIG_VIDEO_LOGO
897 CONFIG_CONSOLE_EXTRA_INFO
898 additional board info beside
901 When CONFIG_CFB_CONSOLE_ANSI is defined, console will support
902 a limited number of ANSI escape sequences (cursor control,
903 erase functions and limited graphics rendition control).
905 When CONFIG_CFB_CONSOLE is defined, video console is
906 default i/o. Serial console can be forced with
907 environment 'console=serial'.
909 When CONFIG_SILENT_CONSOLE is defined, all console
910 messages (by U-Boot and Linux!) can be silenced with
911 the "silent" environment variable. See
912 doc/README.silent for more information.
914 CONFIG_SYS_CONSOLE_BG_COL: define the backgroundcolor, default
916 CONFIG_SYS_CONSOLE_FG_COL: define the foregroundcolor, default
920 CONFIG_BAUDRATE - in bps
921 Select one of the baudrates listed in
922 CONFIG_SYS_BAUDRATE_TABLE, see below.
923 CONFIG_SYS_BRGCLK_PRESCALE, baudrate prescale
925 - Console Rx buffer length
926 With CONFIG_SYS_SMC_RXBUFLEN it is possible to define
927 the maximum receive buffer length for the SMC.
928 This option is actual only for 82xx and 8xx possible.
929 If using CONFIG_SYS_SMC_RXBUFLEN also CONFIG_SYS_MAXIDLE
930 must be defined, to setup the maximum idle timeout for
933 - Pre-Console Buffer:
934 Prior to the console being initialised (i.e. serial UART
935 initialised etc) all console output is silently discarded.
936 Defining CONFIG_PRE_CONSOLE_BUFFER will cause U-Boot to
937 buffer any console messages prior to the console being
938 initialised to a buffer of size CONFIG_PRE_CON_BUF_SZ
939 bytes located at CONFIG_PRE_CON_BUF_ADDR. The buffer is
940 a circular buffer, so if more than CONFIG_PRE_CON_BUF_SZ
941 bytes are output before the console is initialised, the
942 earlier bytes are discarded.
944 'Sane' compilers will generate smaller code if
945 CONFIG_PRE_CON_BUF_SZ is a power of 2
947 - Safe printf() functions
948 Define CONFIG_SYS_VSNPRINTF to compile in safe versions of
949 the printf() functions. These are defined in
950 include/vsprintf.h and include snprintf(), vsnprintf() and
951 so on. Code size increase is approximately 300-500 bytes.
952 If this option is not given then these functions will
953 silently discard their buffer size argument - this means
954 you are not getting any overflow checking in this case.
956 - Boot Delay: CONFIG_BOOTDELAY - in seconds
957 Delay before automatically booting the default image;
958 set to -1 to disable autoboot.
959 set to -2 to autoboot with no delay and not check for abort
960 (even when CONFIG_ZERO_BOOTDELAY_CHECK is defined).
962 See doc/README.autoboot for these options that
963 work with CONFIG_BOOTDELAY. None are required.
964 CONFIG_BOOT_RETRY_TIME
965 CONFIG_BOOT_RETRY_MIN
966 CONFIG_AUTOBOOT_KEYED
967 CONFIG_AUTOBOOT_PROMPT
968 CONFIG_AUTOBOOT_DELAY_STR
969 CONFIG_AUTOBOOT_STOP_STR
970 CONFIG_AUTOBOOT_DELAY_STR2
971 CONFIG_AUTOBOOT_STOP_STR2
972 CONFIG_ZERO_BOOTDELAY_CHECK
973 CONFIG_RESET_TO_RETRY
977 Only needed when CONFIG_BOOTDELAY is enabled;
978 define a command string that is automatically executed
979 when no character is read on the console interface
980 within "Boot Delay" after reset.
983 This can be used to pass arguments to the bootm
984 command. The value of CONFIG_BOOTARGS goes into the
985 environment value "bootargs".
987 CONFIG_RAMBOOT and CONFIG_NFSBOOT
988 The value of these goes into the environment as
989 "ramboot" and "nfsboot" respectively, and can be used
990 as a convenience, when switching between booting from
994 CONFIG_BOOTCOUNT_LIMIT
995 Implements a mechanism for detecting a repeating reboot
997 http://www.denx.de/wiki/view/DULG/UBootBootCountLimit
1000 If no softreset save registers are found on the hardware
1001 "bootcount" is stored in the environment. To prevent a
1002 saveenv on all reboots, the environment variable
1003 "upgrade_available" is used. If "upgrade_available" is
1004 0, "bootcount" is always 0, if "upgrade_available" is
1005 1 "bootcount" is incremented in the environment.
1006 So the Userspace Applikation must set the "upgrade_available"
1007 and "bootcount" variable to 0, if a boot was successfully.
1009 - Pre-Boot Commands:
1012 When this option is #defined, the existence of the
1013 environment variable "preboot" will be checked
1014 immediately before starting the CONFIG_BOOTDELAY
1015 countdown and/or running the auto-boot command resp.
1016 entering interactive mode.
1018 This feature is especially useful when "preboot" is
1019 automatically generated or modified. For an example
1020 see the LWMON board specific code: here "preboot" is
1021 modified when the user holds down a certain
1022 combination of keys on the (special) keyboard when
1025 - Serial Download Echo Mode:
1027 If defined to 1, all characters received during a
1028 serial download (using the "loads" command) are
1029 echoed back. This might be needed by some terminal
1030 emulations (like "cu"), but may as well just take
1031 time on others. This setting #define's the initial
1032 value of the "loads_echo" environment variable.
1034 - Kgdb Serial Baudrate: (if CONFIG_CMD_KGDB is defined)
1035 CONFIG_KGDB_BAUDRATE
1036 Select one of the baudrates listed in
1037 CONFIG_SYS_BAUDRATE_TABLE, see below.
1039 - Monitor Functions:
1040 Monitor commands can be included or excluded
1041 from the build by using the #include files
1042 <config_cmd_all.h> and #undef'ing unwanted
1043 commands, or using <config_cmd_default.h>
1044 and augmenting with additional #define's
1045 for wanted commands.
1047 The default command configuration includes all commands
1048 except those marked below with a "*".
1050 CONFIG_CMD_AES AES 128 CBC encrypt/decrypt
1051 CONFIG_CMD_ASKENV * ask for env variable
1052 CONFIG_CMD_BDI bdinfo
1053 CONFIG_CMD_BEDBUG * Include BedBug Debugger
1054 CONFIG_CMD_BMP * BMP support
1055 CONFIG_CMD_BSP * Board specific commands
1056 CONFIG_CMD_BOOTD bootd
1057 CONFIG_CMD_BOOTI * ARM64 Linux kernel Image support
1058 CONFIG_CMD_CACHE * icache, dcache
1059 CONFIG_CMD_CLK * clock command support
1060 CONFIG_CMD_CONSOLE coninfo
1061 CONFIG_CMD_CRC32 * crc32
1062 CONFIG_CMD_DATE * support for RTC, date/time...
1063 CONFIG_CMD_DHCP * DHCP support
1064 CONFIG_CMD_DIAG * Diagnostics
1065 CONFIG_CMD_DS4510 * ds4510 I2C gpio commands
1066 CONFIG_CMD_DS4510_INFO * ds4510 I2C info command
1067 CONFIG_CMD_DS4510_MEM * ds4510 I2C eeprom/sram commansd
1068 CONFIG_CMD_DS4510_RST * ds4510 I2C rst command
1069 CONFIG_CMD_DTT * Digital Therm and Thermostat
1070 CONFIG_CMD_ECHO echo arguments
1071 CONFIG_CMD_EDITENV edit env variable
1072 CONFIG_CMD_EEPROM * EEPROM read/write support
1073 CONFIG_CMD_ELF * bootelf, bootvx
1074 CONFIG_CMD_ENV_CALLBACK * display details about env callbacks
1075 CONFIG_CMD_ENV_FLAGS * display details about env flags
1076 CONFIG_CMD_ENV_EXISTS * check existence of env variable
1077 CONFIG_CMD_EXPORTENV * export the environment
1078 CONFIG_CMD_EXT2 * ext2 command support
1079 CONFIG_CMD_EXT4 * ext4 command support
1080 CONFIG_CMD_FS_GENERIC * filesystem commands (e.g. load, ls)
1081 that work for multiple fs types
1082 CONFIG_CMD_FS_UUID * Look up a filesystem UUID
1083 CONFIG_CMD_SAVEENV saveenv
1084 CONFIG_CMD_FDC * Floppy Disk Support
1085 CONFIG_CMD_FAT * FAT command support
1086 CONFIG_CMD_FLASH flinfo, erase, protect
1087 CONFIG_CMD_FPGA FPGA device initialization support
1088 CONFIG_CMD_FUSE * Device fuse support
1089 CONFIG_CMD_GETTIME * Get time since boot
1090 CONFIG_CMD_GO * the 'go' command (exec code)
1091 CONFIG_CMD_GREPENV * search environment
1092 CONFIG_CMD_HASH * calculate hash / digest
1093 CONFIG_CMD_HWFLOW * RTS/CTS hw flow control
1094 CONFIG_CMD_I2C * I2C serial bus support
1095 CONFIG_CMD_IDE * IDE harddisk support
1096 CONFIG_CMD_IMI iminfo
1097 CONFIG_CMD_IMLS List all images found in NOR flash
1098 CONFIG_CMD_IMLS_NAND * List all images found in NAND flash
1099 CONFIG_CMD_IMMAP * IMMR dump support
1100 CONFIG_CMD_IOTRACE * I/O tracing for debugging
1101 CONFIG_CMD_IMPORTENV * import an environment
1102 CONFIG_CMD_INI * import data from an ini file into the env
1103 CONFIG_CMD_IRQ * irqinfo
1104 CONFIG_CMD_ITEST Integer/string test of 2 values
1105 CONFIG_CMD_JFFS2 * JFFS2 Support
1106 CONFIG_CMD_KGDB * kgdb
1107 CONFIG_CMD_LDRINFO * ldrinfo (display Blackfin loader)
1108 CONFIG_CMD_LINK_LOCAL * link-local IP address auto-configuration
1110 CONFIG_CMD_LOADB loadb
1111 CONFIG_CMD_LOADS loads
1112 CONFIG_CMD_MD5SUM * print md5 message digest
1113 (requires CONFIG_CMD_MEMORY and CONFIG_MD5)
1114 CONFIG_CMD_MEMINFO * Display detailed memory information
1115 CONFIG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base,
1117 CONFIG_CMD_MEMTEST * mtest
1118 CONFIG_CMD_MISC Misc functions like sleep etc
1119 CONFIG_CMD_MMC * MMC memory mapped support
1120 CONFIG_CMD_MII * MII utility commands
1121 CONFIG_CMD_MTDPARTS * MTD partition support
1122 CONFIG_CMD_NAND * NAND support
1123 CONFIG_CMD_NET bootp, tftpboot, rarpboot
1124 CONFIG_CMD_NFS NFS support
1125 CONFIG_CMD_PCA953X * PCA953x I2C gpio commands
1126 CONFIG_CMD_PCA953X_INFO * PCA953x I2C gpio info command
1127 CONFIG_CMD_PCI * pciinfo
1128 CONFIG_CMD_PCMCIA * PCMCIA support
1129 CONFIG_CMD_PING * send ICMP ECHO_REQUEST to network
1131 CONFIG_CMD_PORTIO * Port I/O
1132 CONFIG_CMD_READ * Read raw data from partition
1133 CONFIG_CMD_REGINFO * Register dump
1134 CONFIG_CMD_RUN run command in env variable
1135 CONFIG_CMD_SANDBOX * sb command to access sandbox features
1136 CONFIG_CMD_SAVES * save S record dump
1137 CONFIG_CMD_SCSI * SCSI Support
1138 CONFIG_CMD_SDRAM * print SDRAM configuration information
1139 (requires CONFIG_CMD_I2C)
1140 CONFIG_CMD_SETGETDCR Support for DCR Register access
1142 CONFIG_CMD_SF * Read/write/erase SPI NOR flash
1143 CONFIG_CMD_SHA1SUM * print sha1 memory digest
1144 (requires CONFIG_CMD_MEMORY)
1145 CONFIG_CMD_SOFTSWITCH * Soft switch setting command for BF60x
1146 CONFIG_CMD_SOURCE "source" command Support
1147 CONFIG_CMD_SPI * SPI serial bus support
1148 CONFIG_CMD_TFTPSRV * TFTP transfer in server mode
1149 CONFIG_CMD_TFTPPUT * TFTP put command (upload)
1150 CONFIG_CMD_TIME * run command and report execution time (ARM specific)
1151 CONFIG_CMD_TIMER * access to the system tick timer
1152 CONFIG_CMD_USB * USB support
1153 CONFIG_CMD_CDP * Cisco Discover Protocol support
1154 CONFIG_CMD_MFSL * Microblaze FSL support
1155 CONFIG_CMD_XIMG Load part of Multi Image
1156 CONFIG_CMD_UUID * Generate random UUID or GUID string
1158 EXAMPLE: If you want all functions except of network
1159 support you can write:
1161 #include "config_cmd_all.h"
1162 #undef CONFIG_CMD_NET
1165 fdt (flattened device tree) command: CONFIG_OF_LIBFDT
1167 Note: Don't enable the "icache" and "dcache" commands
1168 (configuration option CONFIG_CMD_CACHE) unless you know
1169 what you (and your U-Boot users) are doing. Data
1170 cache cannot be enabled on systems like the 8xx or
1171 8260 (where accesses to the IMMR region must be
1172 uncached), and it cannot be disabled on all other
1173 systems where we (mis-) use the data cache to hold an
1174 initial stack and some data.
1177 XXX - this list needs to get updated!
1179 - Regular expression support:
1181 If this variable is defined, U-Boot is linked against
1182 the SLRE (Super Light Regular Expression) library,
1183 which adds regex support to some commands, as for
1184 example "env grep" and "setexpr".
1188 If this variable is defined, U-Boot will use a device tree
1189 to configure its devices, instead of relying on statically
1190 compiled #defines in the board file. This option is
1191 experimental and only available on a few boards. The device
1192 tree is available in the global data as gd->fdt_blob.
1194 U-Boot needs to get its device tree from somewhere. This can
1195 be done using one of the two options below:
1198 If this variable is defined, U-Boot will embed a device tree
1199 binary in its image. This device tree file should be in the
1200 board directory and called <soc>-<board>.dts. The binary file
1201 is then picked up in board_init_f() and made available through
1202 the global data structure as gd->blob.
1205 If this variable is defined, U-Boot will build a device tree
1206 binary. It will be called u-boot.dtb. Architecture-specific
1207 code will locate it at run-time. Generally this works by:
1209 cat u-boot.bin u-boot.dtb >image.bin
1211 and in fact, U-Boot does this for you, creating a file called
1212 u-boot-dtb.bin which is useful in the common case. You can
1213 still use the individual files if you need something more
1218 If this variable is defined, it enables watchdog
1219 support for the SoC. There must be support in the SoC
1220 specific code for a watchdog. For the 8xx and 8260
1221 CPUs, the SIU Watchdog feature is enabled in the SYPCR
1222 register. When supported for a specific SoC is
1223 available, then no further board specific code should
1224 be needed to use it.
1227 When using a watchdog circuitry external to the used
1228 SoC, then define this variable and provide board
1229 specific code for the "hw_watchdog_reset" function.
1231 CONFIG_AT91_HW_WDT_TIMEOUT
1232 specify the timeout in seconds. default 2 seconds.
1235 CONFIG_VERSION_VARIABLE
1236 If this variable is defined, an environment variable
1237 named "ver" is created by U-Boot showing the U-Boot
1238 version as printed by the "version" command.
1239 Any change to this variable will be reverted at the
1244 When CONFIG_CMD_DATE is selected, the type of the RTC
1245 has to be selected, too. Define exactly one of the
1248 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx
1249 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC
1250 CONFIG_RTC_MC13XXX - use MC13783 or MC13892 RTC
1251 CONFIG_RTC_MC146818 - use MC146818 RTC
1252 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC
1253 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC
1254 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC
1255 CONFIG_RTC_DS1339 - use Maxim, Inc. DS1339 RTC
1256 CONFIG_RTC_DS164x - use Dallas DS164x RTC
1257 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC
1258 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC
1259 CONFIG_SYS_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337
1260 CONFIG_SYS_RV3029_TCR - enable trickle charger on
1263 Note that if the RTC uses I2C, then the I2C interface
1264 must also be configured. See I2C Support, below.
1267 CONFIG_PCA953X - use NXP's PCA953X series I2C GPIO
1269 The CONFIG_SYS_I2C_PCA953X_WIDTH option specifies a list of
1270 chip-ngpio pairs that tell the PCA953X driver the number of
1271 pins supported by a particular chip.
1273 Note that if the GPIO device uses I2C, then the I2C interface
1274 must also be configured. See I2C Support, below.
1277 When CONFIG_IO_TRACE is selected, U-Boot intercepts all I/O
1278 accesses and can checksum them or write a list of them out
1279 to memory. See the 'iotrace' command for details. This is
1280 useful for testing device drivers since it can confirm that
1281 the driver behaves the same way before and after a code
1282 change. Currently this is supported on sandbox and arm. To
1283 add support for your architecture, add '#include <iotrace.h>'
1284 to the bottom of arch/<arch>/include/asm/io.h and test.
1286 Example output from the 'iotrace stats' command is below.
1287 Note that if the trace buffer is exhausted, the checksum will
1288 still continue to operate.
1291 Start: 10000000 (buffer start address)
1292 Size: 00010000 (buffer size)
1293 Offset: 00000120 (current buffer offset)
1294 Output: 10000120 (start + offset)
1295 Count: 00000018 (number of trace records)
1296 CRC32: 9526fb66 (CRC32 of all trace records)
1298 - Timestamp Support:
1300 When CONFIG_TIMESTAMP is selected, the timestamp
1301 (date and time) of an image is printed by image
1302 commands like bootm or iminfo. This option is
1303 automatically enabled when you select CONFIG_CMD_DATE .
1305 - Partition Labels (disklabels) Supported:
1306 Zero or more of the following:
1307 CONFIG_MAC_PARTITION Apple's MacOS partition table.
1308 CONFIG_DOS_PARTITION MS Dos partition table, traditional on the
1309 Intel architecture, USB sticks, etc.
1310 CONFIG_ISO_PARTITION ISO partition table, used on CDROM etc.
1311 CONFIG_EFI_PARTITION GPT partition table, common when EFI is the
1312 bootloader. Note 2TB partition limit; see
1314 CONFIG_MTD_PARTITIONS Memory Technology Device partition table.
1316 If IDE or SCSI support is enabled (CONFIG_CMD_IDE or
1317 CONFIG_CMD_SCSI) you must configure support for at
1318 least one non-MTD partition type as well.
1321 CONFIG_IDE_RESET_ROUTINE - this is defined in several
1322 board configurations files but used nowhere!
1324 CONFIG_IDE_RESET - is this is defined, IDE Reset will
1325 be performed by calling the function
1326 ide_set_reset(int reset)
1327 which has to be defined in a board specific file
1332 Set this to enable ATAPI support.
1337 Set this to enable support for disks larger than 137GB
1338 Also look at CONFIG_SYS_64BIT_LBA.
1339 Whithout these , LBA48 support uses 32bit variables and will 'only'
1340 support disks up to 2.1TB.
1342 CONFIG_SYS_64BIT_LBA:
1343 When enabled, makes the IDE subsystem use 64bit sector addresses.
1347 At the moment only there is only support for the
1348 SYM53C8XX SCSI controller; define
1349 CONFIG_SCSI_SYM53C8XX to enable it.
1351 CONFIG_SYS_SCSI_MAX_LUN [8], CONFIG_SYS_SCSI_MAX_SCSI_ID [7] and
1352 CONFIG_SYS_SCSI_MAX_DEVICE [CONFIG_SYS_SCSI_MAX_SCSI_ID *
1353 CONFIG_SYS_SCSI_MAX_LUN] can be adjusted to define the
1354 maximum numbers of LUNs, SCSI ID's and target
1356 CONFIG_SYS_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz)
1358 The environment variable 'scsidevs' is set to the number of
1359 SCSI devices found during the last scan.
1361 - NETWORK Support (PCI):
1363 Support for Intel 8254x/8257x gigabit chips.
1366 Utility code for direct access to the SPI bus on Intel 8257x.
1367 This does not do anything useful unless you set at least one
1368 of CONFIG_CMD_E1000 or CONFIG_E1000_SPI_GENERIC.
1370 CONFIG_E1000_SPI_GENERIC
1371 Allow generic access to the SPI bus on the Intel 8257x, for
1372 example with the "sspi" command.
1375 Management command for E1000 devices. When used on devices
1376 with SPI support you can reprogram the EEPROM from U-Boot.
1378 CONFIG_E1000_FALLBACK_MAC
1379 default MAC for empty EEPROM after production.
1382 Support for Intel 82557/82559/82559ER chips.
1383 Optional CONFIG_EEPRO100_SROM_WRITE enables EEPROM
1384 write routine for first time initialisation.
1387 Support for Digital 2114x chips.
1388 Optional CONFIG_TULIP_SELECT_MEDIA for board specific
1389 modem chip initialisation (KS8761/QS6611).
1392 Support for National dp83815 chips.
1395 Support for National dp8382[01] gigabit chips.
1397 - NETWORK Support (other):
1399 CONFIG_DRIVER_AT91EMAC
1400 Support for AT91RM9200 EMAC.
1403 Define this to use reduced MII inteface
1405 CONFIG_DRIVER_AT91EMAC_QUIET
1406 If this defined, the driver is quiet.
1407 The driver doen't show link status messages.
1409 CONFIG_CALXEDA_XGMAC
1410 Support for the Calxeda XGMAC device
1413 Support for SMSC's LAN91C96 chips.
1415 CONFIG_LAN91C96_BASE
1416 Define this to hold the physical address
1417 of the LAN91C96's I/O space
1419 CONFIG_LAN91C96_USE_32_BIT
1420 Define this to enable 32 bit addressing
1423 Support for SMSC's LAN91C111 chip
1425 CONFIG_SMC91111_BASE
1426 Define this to hold the physical address
1427 of the device (I/O space)
1429 CONFIG_SMC_USE_32_BIT
1430 Define this if data bus is 32 bits
1432 CONFIG_SMC_USE_IOFUNCS
1433 Define this to use i/o functions instead of macros
1434 (some hardware wont work with macros)
1436 CONFIG_DRIVER_TI_EMAC
1437 Support for davinci emac
1439 CONFIG_SYS_DAVINCI_EMAC_PHY_COUNT
1440 Define this if you have more then 3 PHYs.
1443 Support for Faraday's FTGMAC100 Gigabit SoC Ethernet
1445 CONFIG_FTGMAC100_EGIGA
1446 Define this to use GE link update with gigabit PHY.
1447 Define this if FTGMAC100 is connected to gigabit PHY.
1448 If your system has 10/100 PHY only, it might not occur
1449 wrong behavior. Because PHY usually return timeout or
1450 useless data when polling gigabit status and gigabit
1451 control registers. This behavior won't affect the
1452 correctnessof 10/100 link speed update.
1455 Support for SMSC's LAN911x and LAN921x chips
1458 Define this to hold the physical address
1459 of the device (I/O space)
1461 CONFIG_SMC911X_32_BIT
1462 Define this if data bus is 32 bits
1464 CONFIG_SMC911X_16_BIT
1465 Define this if data bus is 16 bits. If your processor
1466 automatically converts one 32 bit word to two 16 bit
1467 words you may also try CONFIG_SMC911X_32_BIT.
1470 Support for Renesas on-chip Ethernet controller
1472 CONFIG_SH_ETHER_USE_PORT
1473 Define the number of ports to be used
1475 CONFIG_SH_ETHER_PHY_ADDR
1476 Define the ETH PHY's address
1478 CONFIG_SH_ETHER_CACHE_WRITEBACK
1479 If this option is set, the driver enables cache flush.
1483 Support for PWM modul on the imx6.
1487 Support TPM devices.
1490 Support for i2c bus TPM devices. Only one device
1491 per system is supported at this time.
1493 CONFIG_TPM_TIS_I2C_BUS_NUMBER
1494 Define the the i2c bus number for the TPM device
1496 CONFIG_TPM_TIS_I2C_SLAVE_ADDRESS
1497 Define the TPM's address on the i2c bus
1499 CONFIG_TPM_TIS_I2C_BURST_LIMITATION
1500 Define the burst count bytes upper limit
1502 CONFIG_TPM_ATMEL_TWI
1503 Support for Atmel TWI TPM device. Requires I2C support.
1506 Support for generic parallel port TPM devices. Only one device
1507 per system is supported at this time.
1509 CONFIG_TPM_TIS_BASE_ADDRESS
1510 Base address where the generic TPM device is mapped
1511 to. Contemporary x86 systems usually map it at
1515 Add tpm monitor functions.
1516 Requires CONFIG_TPM. If CONFIG_TPM_AUTH_SESSIONS is set, also
1517 provides monitor access to authorized functions.
1520 Define this to enable the TPM support library which provides
1521 functional interfaces to some TPM commands.
1522 Requires support for a TPM device.
1524 CONFIG_TPM_AUTH_SESSIONS
1525 Define this to enable authorized functions in the TPM library.
1526 Requires CONFIG_TPM and CONFIG_SHA1.
1529 At the moment only the UHCI host controller is
1530 supported (PIP405, MIP405, MPC5200); define
1531 CONFIG_USB_UHCI to enable it.
1532 define CONFIG_USB_KEYBOARD to enable the USB Keyboard
1533 and define CONFIG_USB_STORAGE to enable the USB
1536 Supported are USB Keyboards and USB Floppy drives
1538 MPC5200 USB requires additional defines:
1540 for 528 MHz Clock: 0x0001bbbb
1544 for differential drivers: 0x00001000
1545 for single ended drivers: 0x00005000
1546 for differential drivers on PSC3: 0x00000100
1547 for single ended drivers on PSC3: 0x00004100
1548 CONFIG_SYS_USB_EVENT_POLL
1549 May be defined to allow interrupt polling
1550 instead of using asynchronous interrupts
1552 CONFIG_USB_EHCI_TXFIFO_THRESH enables setting of the
1553 txfilltuning field in the EHCI controller on reset.
1555 CONFIG_USB_DWC2_REG_ADDR the physical CPU address of the DWC2
1556 HW module registers.
1559 Define the below if you wish to use the USB console.
1560 Once firmware is rebuilt from a serial console issue the
1561 command "setenv stdin usbtty; setenv stdout usbtty" and
1562 attach your USB cable. The Unix command "dmesg" should print
1563 it has found a new device. The environment variable usbtty
1564 can be set to gserial or cdc_acm to enable your device to
1565 appear to a USB host as a Linux gserial device or a
1566 Common Device Class Abstract Control Model serial device.
1567 If you select usbtty = gserial you should be able to enumerate
1569 # modprobe usbserial vendor=0xVendorID product=0xProductID
1570 else if using cdc_acm, simply setting the environment
1571 variable usbtty to be cdc_acm should suffice. The following
1572 might be defined in YourBoardName.h
1575 Define this to build a UDC device
1578 Define this to have a tty type of device available to
1579 talk to the UDC device
1582 Define this to enable the high speed support for usb
1583 device and usbtty. If this feature is enabled, a routine
1584 int is_usbd_high_speed(void)
1585 also needs to be defined by the driver to dynamically poll
1586 whether the enumeration has succeded at high speed or full
1589 CONFIG_SYS_CONSOLE_IS_IN_ENV
1590 Define this if you want stdin, stdout &/or stderr to
1594 CONFIG_SYS_USB_EXTC_CLK 0xBLAH
1595 Derive USB clock from external clock "blah"
1596 - CONFIG_SYS_USB_EXTC_CLK 0x02
1598 CONFIG_SYS_USB_BRG_CLK 0xBLAH
1599 Derive USB clock from brgclk
1600 - CONFIG_SYS_USB_BRG_CLK 0x04
1602 If you have a USB-IF assigned VendorID then you may wish to
1603 define your own vendor specific values either in BoardName.h
1604 or directly in usbd_vendor_info.h. If you don't define
1605 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME,
1606 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot
1607 should pretend to be a Linux device to it's target host.
1609 CONFIG_USBD_MANUFACTURER
1610 Define this string as the name of your company for
1611 - CONFIG_USBD_MANUFACTURER "my company"
1613 CONFIG_USBD_PRODUCT_NAME
1614 Define this string as the name of your product
1615 - CONFIG_USBD_PRODUCT_NAME "acme usb device"
1617 CONFIG_USBD_VENDORID
1618 Define this as your assigned Vendor ID from the USB
1619 Implementors Forum. This *must* be a genuine Vendor ID
1620 to avoid polluting the USB namespace.
1621 - CONFIG_USBD_VENDORID 0xFFFF
1623 CONFIG_USBD_PRODUCTID
1624 Define this as the unique Product ID
1626 - CONFIG_USBD_PRODUCTID 0xFFFF
1628 - ULPI Layer Support:
1629 The ULPI (UTMI Low Pin (count) Interface) PHYs are supported via
1630 the generic ULPI layer. The generic layer accesses the ULPI PHY
1631 via the platform viewport, so you need both the genric layer and
1632 the viewport enabled. Currently only Chipidea/ARC based
1633 viewport is supported.
1634 To enable the ULPI layer support, define CONFIG_USB_ULPI and
1635 CONFIG_USB_ULPI_VIEWPORT in your board configuration file.
1636 If your ULPI phy needs a different reference clock than the
1637 standard 24 MHz then you have to define CONFIG_ULPI_REF_CLK to
1638 the appropriate value in Hz.
1641 The MMC controller on the Intel PXA is supported. To
1642 enable this define CONFIG_MMC. The MMC can be
1643 accessed from the boot prompt by mapping the device
1644 to physical memory similar to flash. Command line is
1645 enabled with CONFIG_CMD_MMC. The MMC driver also works with
1646 the FAT fs. This is enabled with CONFIG_CMD_FAT.
1649 Support for Renesas on-chip MMCIF controller
1651 CONFIG_SH_MMCIF_ADDR
1652 Define the base address of MMCIF registers
1655 Define the clock frequency for MMCIF
1658 Enable the generic MMC driver
1660 CONFIG_SUPPORT_EMMC_BOOT
1661 Enable some additional features of the eMMC boot partitions.
1663 CONFIG_SUPPORT_EMMC_RPMB
1664 Enable the commands for reading, writing and programming the
1665 key for the Replay Protection Memory Block partition in eMMC.
1667 - USB Device Firmware Update (DFU) class support:
1669 This enables the USB portion of the DFU USB class
1672 This enables the command "dfu" which is used to have
1673 U-Boot create a DFU class device via USB. This command
1674 requires that the "dfu_alt_info" environment variable be
1675 set and define the alt settings to expose to the host.
1678 This enables support for exposing (e)MMC devices via DFU.
1681 This enables support for exposing NAND devices via DFU.
1684 This enables support for exposing RAM via DFU.
1685 Note: DFU spec refer to non-volatile memory usage, but
1686 allow usages beyond the scope of spec - here RAM usage,
1687 one that would help mostly the developer.
1689 CONFIG_SYS_DFU_DATA_BUF_SIZE
1690 Dfu transfer uses a buffer before writing data to the
1691 raw storage device. Make the size (in bytes) of this buffer
1692 configurable. The size of this buffer is also configurable
1693 through the "dfu_bufsiz" environment variable.
1695 CONFIG_SYS_DFU_MAX_FILE_SIZE
1696 When updating files rather than the raw storage device,
1697 we use a static buffer to copy the file into and then write
1698 the buffer once we've been given the whole file. Define
1699 this to the maximum filesize (in bytes) for the buffer.
1700 Default is 4 MiB if undefined.
1702 DFU_DEFAULT_POLL_TIMEOUT
1703 Poll timeout [ms], is the timeout a device can send to the
1704 host. The host must wait for this timeout before sending
1705 a subsequent DFU_GET_STATUS request to the device.
1707 DFU_MANIFEST_POLL_TIMEOUT
1708 Poll timeout [ms], which the device sends to the host when
1709 entering dfuMANIFEST state. Host waits this timeout, before
1710 sending again an USB request to the device.
1712 - USB Device Android Fastboot support:
1714 This enables the command "fastboot" which enables the Android
1715 fastboot mode for the platform's USB device. Fastboot is a USB
1716 protocol for downloading images, flashing and device control
1717 used on Android devices.
1718 See doc/README.android-fastboot for more information.
1720 CONFIG_ANDROID_BOOT_IMAGE
1721 This enables support for booting images which use the Android
1722 image format header.
1724 CONFIG_USB_FASTBOOT_BUF_ADDR
1725 The fastboot protocol requires a large memory buffer for
1726 downloads. Define this to the starting RAM address to use for
1729 CONFIG_USB_FASTBOOT_BUF_SIZE
1730 The fastboot protocol requires a large memory buffer for
1731 downloads. This buffer should be as large as possible for a
1732 platform. Define this to the size available RAM for fastboot.
1734 CONFIG_FASTBOOT_FLASH
1735 The fastboot protocol includes a "flash" command for writing
1736 the downloaded image to a non-volatile storage device. Define
1737 this to enable the "fastboot flash" command.
1739 CONFIG_FASTBOOT_FLASH_MMC_DEV
1740 The fastboot "flash" command requires additional information
1741 regarding the non-volatile storage device. Define this to
1742 the eMMC device that fastboot should use to store the image.
1744 CONFIG_FASTBOOT_GPT_NAME
1745 The fastboot "flash" command supports writing the downloaded
1746 image to the Protective MBR and the Primary GUID Partition
1747 Table. (Additionally, this downloaded image is post-processed
1748 to generate and write the Backup GUID Partition Table.)
1749 This occurs when the specified "partition name" on the
1750 "fastboot flash" command line matches this value.
1751 Default is GPT_ENTRY_NAME (currently "gpt") if undefined.
1753 - Journaling Flash filesystem support:
1754 CONFIG_JFFS2_NAND, CONFIG_JFFS2_NAND_OFF, CONFIG_JFFS2_NAND_SIZE,
1755 CONFIG_JFFS2_NAND_DEV
1756 Define these for a default partition on a NAND device
1758 CONFIG_SYS_JFFS2_FIRST_SECTOR,
1759 CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS
1760 Define these for a default partition on a NOR device
1762 CONFIG_SYS_JFFS_CUSTOM_PART
1763 Define this to create an own partition. You have to provide a
1764 function struct part_info* jffs2_part_info(int part_num)
1766 If you define only one JFFS2 partition you may also want to
1767 #define CONFIG_SYS_JFFS_SINGLE_PART 1
1768 to disable the command chpart. This is the default when you
1769 have not defined a custom partition
1771 - FAT(File Allocation Table) filesystem write function support:
1774 Define this to enable support for saving memory data as a
1775 file in FAT formatted partition.
1777 This will also enable the command "fatwrite" enabling the
1778 user to write files to FAT.
1780 CBFS (Coreboot Filesystem) support
1783 Define this to enable support for reading from a Coreboot
1784 filesystem. Available commands are cbfsinit, cbfsinfo, cbfsls
1787 - FAT(File Allocation Table) filesystem cluster size:
1788 CONFIG_FS_FAT_MAX_CLUSTSIZE
1790 Define the max cluster size for fat operations else
1791 a default value of 65536 will be defined.
1796 Define this to enable standard (PC-Style) keyboard
1800 Standard PC keyboard driver with US (is default) and
1801 GERMAN key layout (switch via environment 'keymap=de') support.
1802 Export function i8042_kbd_init, i8042_tstc and i8042_getc
1803 for cfb_console. Supports cursor blinking.
1806 Enables a Chrome OS keyboard using the CROS_EC interface.
1807 This uses CROS_EC to communicate with a second microcontroller
1808 which provides key scans on request.
1813 Define this to enable video support (for output to
1816 CONFIG_VIDEO_CT69000
1818 Enable Chips & Technologies 69000 Video chip
1820 CONFIG_VIDEO_SMI_LYNXEM
1821 Enable Silicon Motion SMI 712/710/810 Video chip. The
1822 video output is selected via environment 'videoout'
1823 (1 = LCD and 2 = CRT). If videoout is undefined, CRT is
1826 For the CT69000 and SMI_LYNXEM drivers, videomode is
1827 selected via environment 'videomode'. Two different ways
1829 - "videomode=num" 'num' is a standard LiLo mode numbers.
1830 Following standard modes are supported (* is default):
1832 Colors 640x480 800x600 1024x768 1152x864 1280x1024
1833 -------------+---------------------------------------------
1834 8 bits | 0x301* 0x303 0x305 0x161 0x307
1835 15 bits | 0x310 0x313 0x316 0x162 0x319
1836 16 bits | 0x311 0x314 0x317 0x163 0x31A
1837 24 bits | 0x312 0x315 0x318 ? 0x31B
1838 -------------+---------------------------------------------
1839 (i.e. setenv videomode 317; saveenv; reset;)
1841 - "videomode=bootargs" all the video parameters are parsed
1842 from the bootargs. (See drivers/video/videomodes.c)
1845 CONFIG_VIDEO_SED13806
1846 Enable Epson SED13806 driver. This driver supports 8bpp
1847 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP
1848 or CONFIG_VIDEO_SED13806_16BPP
1851 Enable the Freescale DIU video driver. Reference boards for
1852 SOCs that have a DIU should define this macro to enable DIU
1853 support, and should also define these other macros:
1859 CONFIG_VIDEO_SW_CURSOR
1860 CONFIG_VGA_AS_SINGLE_DEVICE
1862 CONFIG_VIDEO_BMP_LOGO
1864 The DIU driver will look for the 'video-mode' environment
1865 variable, and if defined, enable the DIU as a console during
1866 boot. See the documentation file README.video for a
1867 description of this variable.
1871 Enable the VGA video / BIOS for x86. The alternative if you
1872 are using coreboot is to use the coreboot frame buffer
1879 Define this to enable a custom keyboard support.
1880 This simply calls drv_keyboard_init() which must be
1881 defined in your board-specific files.
1882 The only board using this so far is RBC823.
1884 - LCD Support: CONFIG_LCD
1886 Define this to enable LCD support (for output to LCD
1887 display); also select one of the supported displays
1888 by defining one of these:
1892 HITACHI TX09D70VM1CCA, 3.5", 240x320.
1894 CONFIG_NEC_NL6448AC33:
1896 NEC NL6448AC33-18. Active, color, single scan.
1898 CONFIG_NEC_NL6448BC20
1900 NEC NL6448BC20-08. 6.5", 640x480.
1901 Active, color, single scan.
1903 CONFIG_NEC_NL6448BC33_54
1905 NEC NL6448BC33-54. 10.4", 640x480.
1906 Active, color, single scan.
1910 Sharp 320x240. Active, color, single scan.
1911 It isn't 16x9, and I am not sure what it is.
1913 CONFIG_SHARP_LQ64D341
1915 Sharp LQ64D341 display, 640x480.
1916 Active, color, single scan.
1920 HLD1045 display, 640x480.
1921 Active, color, single scan.
1925 Optrex CBL50840-2 NF-FW 99 22 M5
1927 Hitachi LMG6912RPFC-00T
1931 320x240. Black & white.
1933 Normally display is black on white background; define
1934 CONFIG_SYS_WHITE_ON_BLACK to get it inverted.
1936 CONFIG_LCD_ALIGNMENT
1938 Normally the LCD is page-aligned (typically 4KB). If this is
1939 defined then the LCD will be aligned to this value instead.
1940 For ARM it is sometimes useful to use MMU_SECTION_SIZE
1941 here, since it is cheaper to change data cache settings on
1942 a per-section basis.
1944 CONFIG_CONSOLE_SCROLL_LINES
1946 When the console need to be scrolled, this is the number of
1947 lines to scroll by. It defaults to 1. Increasing this makes
1948 the console jump but can help speed up operation when scrolling
1953 Support drawing of RLE8-compressed bitmaps on the LCD.
1957 Enables an 'i2c edid' command which can read EDID
1958 information over I2C from an attached LCD display.
1960 - Splash Screen Support: CONFIG_SPLASH_SCREEN
1962 If this option is set, the environment is checked for
1963 a variable "splashimage". If found, the usual display
1964 of logo, copyright and system information on the LCD
1965 is suppressed and the BMP image at the address
1966 specified in "splashimage" is loaded instead. The
1967 console is redirected to the "nulldev", too. This
1968 allows for a "silent" boot where a splash screen is
1969 loaded very quickly after power-on.
1971 CONFIG_SPLASHIMAGE_GUARD
1973 If this option is set, then U-Boot will prevent the environment
1974 variable "splashimage" from being set to a problematic address
1975 (see README.displaying-bmps).
1976 This option is useful for targets where, due to alignment
1977 restrictions, an improperly aligned BMP image will cause a data
1978 abort. If you think you will not have problems with unaligned
1979 accesses (for example because your toolchain prevents them)
1980 there is no need to set this option.
1982 CONFIG_SPLASH_SCREEN_ALIGN
1984 If this option is set the splash image can be freely positioned
1985 on the screen. Environment variable "splashpos" specifies the
1986 position as "x,y". If a positive number is given it is used as
1987 number of pixel from left/top. If a negative number is given it
1988 is used as number of pixel from right/bottom. You can also
1989 specify 'm' for centering the image.
1992 setenv splashpos m,m
1993 => image at center of screen
1995 setenv splashpos 30,20
1996 => image at x = 30 and y = 20
1998 setenv splashpos -10,m
1999 => vertically centered image
2000 at x = dspWidth - bmpWidth - 9
2002 - Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP
2004 If this option is set, additionally to standard BMP
2005 images, gzipped BMP images can be displayed via the
2006 splashscreen support or the bmp command.
2008 - Run length encoded BMP image (RLE8) support: CONFIG_VIDEO_BMP_RLE8
2010 If this option is set, 8-bit RLE compressed BMP images
2011 can be displayed via the splashscreen support or the
2014 - Do compressing for memory range:
2017 If this option is set, it would use zlib deflate method
2018 to compress the specified memory at its best effort.
2020 - Compression support:
2023 Enabled by default to support gzip compressed images.
2027 If this option is set, support for bzip2 compressed
2028 images is included. If not, only uncompressed and gzip
2029 compressed images are supported.
2031 NOTE: the bzip2 algorithm requires a lot of RAM, so
2032 the malloc area (as defined by CONFIG_SYS_MALLOC_LEN) should
2037 If this option is set, support for lzma compressed
2040 Note: The LZMA algorithm adds between 2 and 4KB of code and it
2041 requires an amount of dynamic memory that is given by the
2044 (1846 + 768 << (lc + lp)) * sizeof(uint16)
2046 Where lc and lp stand for, respectively, Literal context bits
2047 and Literal pos bits.
2049 This value is upper-bounded by 14MB in the worst case. Anyway,
2050 for a ~4MB large kernel image, we have lc=3 and lp=0 for a
2051 total amount of (1846 + 768 << (3 + 0)) * 2 = ~41KB... that is
2052 a very small buffer.
2054 Use the lzmainfo tool to determinate the lc and lp values and
2055 then calculate the amount of needed dynamic memory (ensuring
2056 the appropriate CONFIG_SYS_MALLOC_LEN value).
2060 If this option is set, support for LZO compressed images
2066 The address of PHY on MII bus.
2068 CONFIG_PHY_CLOCK_FREQ (ppc4xx)
2070 The clock frequency of the MII bus
2074 If this option is set, support for speed/duplex
2075 detection of gigabit PHY is included.
2077 CONFIG_PHY_RESET_DELAY
2079 Some PHY like Intel LXT971A need extra delay after
2080 reset before any MII register access is possible.
2081 For such PHY, set this option to the usec delay
2082 required. (minimum 300usec for LXT971A)
2084 CONFIG_PHY_CMD_DELAY (ppc4xx)
2086 Some PHY like Intel LXT971A need extra delay after
2087 command issued before MII status register can be read
2097 Define a default value for Ethernet address to use
2098 for the respective Ethernet interface, in case this
2099 is not determined automatically.
2104 Define a default value for the IP address to use for
2105 the default Ethernet interface, in case this is not
2106 determined through e.g. bootp.
2107 (Environment variable "ipaddr")
2109 - Server IP address:
2112 Defines a default value for the IP address of a TFTP
2113 server to contact when using the "tftboot" command.
2114 (Environment variable "serverip")
2116 CONFIG_KEEP_SERVERADDR
2118 Keeps the server's MAC address, in the env 'serveraddr'
2119 for passing to bootargs (like Linux's netconsole option)
2121 - Gateway IP address:
2124 Defines a default value for the IP address of the
2125 default router where packets to other networks are
2127 (Environment variable "gatewayip")
2132 Defines a default value for the subnet mask (or
2133 routing prefix) which is used to determine if an IP
2134 address belongs to the local subnet or needs to be
2135 forwarded through a router.
2136 (Environment variable "netmask")
2138 - Multicast TFTP Mode:
2141 Defines whether you want to support multicast TFTP as per
2142 rfc-2090; for example to work with atftp. Lets lots of targets
2143 tftp down the same boot image concurrently. Note: the Ethernet
2144 driver in use must provide a function: mcast() to join/leave a
2147 - BOOTP Recovery Mode:
2148 CONFIG_BOOTP_RANDOM_DELAY
2150 If you have many targets in a network that try to
2151 boot using BOOTP, you may want to avoid that all
2152 systems send out BOOTP requests at precisely the same
2153 moment (which would happen for instance at recovery
2154 from a power failure, when all systems will try to
2155 boot, thus flooding the BOOTP server. Defining
2156 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
2157 inserted before sending out BOOTP requests. The
2158 following delays are inserted then:
2160 1st BOOTP request: delay 0 ... 1 sec
2161 2nd BOOTP request: delay 0 ... 2 sec
2162 3rd BOOTP request: delay 0 ... 4 sec
2164 BOOTP requests: delay 0 ... 8 sec
2166 CONFIG_BOOTP_ID_CACHE_SIZE
2168 BOOTP packets are uniquely identified using a 32-bit ID. The
2169 server will copy the ID from client requests to responses and
2170 U-Boot will use this to determine if it is the destination of
2171 an incoming response. Some servers will check that addresses
2172 aren't in use before handing them out (usually using an ARP
2173 ping) and therefore take up to a few hundred milliseconds to
2174 respond. Network congestion may also influence the time it
2175 takes for a response to make it back to the client. If that
2176 time is too long, U-Boot will retransmit requests. In order
2177 to allow earlier responses to still be accepted after these
2178 retransmissions, U-Boot's BOOTP client keeps a small cache of
2179 IDs. The CONFIG_BOOTP_ID_CACHE_SIZE controls the size of this
2180 cache. The default is to keep IDs for up to four outstanding
2181 requests. Increasing this will allow U-Boot to accept offers
2182 from a BOOTP client in networks with unusually high latency.
2184 - BOOTP Random transaction ID:
2185 CONFIG_BOOTP_RANDOM_ID
2187 The standard algorithm to generate a DHCP/BOOTP transaction ID
2188 by using the MAC address and the current time stamp may not
2189 quite unlikely produce duplicate transaction IDs from different
2190 clients in the same network. This option creates a transaction
2191 ID using the rand() function. Provided that the RNG has been
2192 seeded well, this should guarantee unique transaction IDs
2195 - DHCP Advanced Options:
2196 You can fine tune the DHCP functionality by defining
2197 CONFIG_BOOTP_* symbols:
2199 CONFIG_BOOTP_SUBNETMASK
2200 CONFIG_BOOTP_GATEWAY
2201 CONFIG_BOOTP_HOSTNAME
2202 CONFIG_BOOTP_NISDOMAIN
2203 CONFIG_BOOTP_BOOTPATH
2204 CONFIG_BOOTP_BOOTFILESIZE
2207 CONFIG_BOOTP_SEND_HOSTNAME
2208 CONFIG_BOOTP_NTPSERVER
2209 CONFIG_BOOTP_TIMEOFFSET
2210 CONFIG_BOOTP_VENDOREX
2211 CONFIG_BOOTP_MAY_FAIL
2213 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip
2214 environment variable, not the BOOTP server.
2216 CONFIG_BOOTP_MAY_FAIL - If the DHCP server is not found
2217 after the configured retry count, the call will fail
2218 instead of starting over. This can be used to fail over
2219 to Link-local IP address configuration if the DHCP server
2222 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS
2223 serverip from a DHCP server, it is possible that more
2224 than one DNS serverip is offered to the client.
2225 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS
2226 serverip will be stored in the additional environment
2227 variable "dnsip2". The first DNS serverip is always
2228 stored in the variable "dnsip", when CONFIG_BOOTP_DNS
2231 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable
2232 to do a dynamic update of a DNS server. To do this, they
2233 need the hostname of the DHCP requester.
2234 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content
2235 of the "hostname" environment variable is passed as
2236 option 12 to the DHCP server.
2238 CONFIG_BOOTP_DHCP_REQUEST_DELAY
2240 A 32bit value in microseconds for a delay between
2241 receiving a "DHCP Offer" and sending the "DHCP Request".
2242 This fixes a problem with certain DHCP servers that don't
2243 respond 100% of the time to a "DHCP request". E.g. On an
2244 AT91RM9200 processor running at 180MHz, this delay needed
2245 to be *at least* 15,000 usec before a Windows Server 2003
2246 DHCP server would reply 100% of the time. I recommend at
2247 least 50,000 usec to be safe. The alternative is to hope
2248 that one of the retries will be successful but note that
2249 the DHCP timeout and retry process takes a longer than
2252 - Link-local IP address negotiation:
2253 Negotiate with other link-local clients on the local network
2254 for an address that doesn't require explicit configuration.
2255 This is especially useful if a DHCP server cannot be guaranteed
2256 to exist in all environments that the device must operate.
2258 See doc/README.link-local for more information.
2261 CONFIG_CDP_DEVICE_ID
2263 The device id used in CDP trigger frames.
2265 CONFIG_CDP_DEVICE_ID_PREFIX
2267 A two character string which is prefixed to the MAC address
2272 A printf format string which contains the ascii name of
2273 the port. Normally is set to "eth%d" which sets
2274 eth0 for the first Ethernet, eth1 for the second etc.
2276 CONFIG_CDP_CAPABILITIES
2278 A 32bit integer which indicates the device capabilities;
2279 0x00000010 for a normal host which does not forwards.
2283 An ascii string containing the version of the software.
2287 An ascii string containing the name of the platform.
2291 A 32bit integer sent on the trigger.
2293 CONFIG_CDP_POWER_CONSUMPTION
2295 A 16bit integer containing the power consumption of the
2296 device in .1 of milliwatts.
2298 CONFIG_CDP_APPLIANCE_VLAN_TYPE
2300 A byte containing the id of the VLAN.
2302 - Status LED: CONFIG_STATUS_LED
2304 Several configurations allow to display the current
2305 status using a LED. For instance, the LED will blink
2306 fast while running U-Boot code, stop blinking as
2307 soon as a reply to a BOOTP request was received, and
2308 start blinking slow once the Linux kernel is running
2309 (supported by a status LED driver in the Linux
2310 kernel). Defining CONFIG_STATUS_LED enables this
2316 The status LED can be connected to a GPIO pin.
2317 In such cases, the gpio_led driver can be used as a
2318 status LED backend implementation. Define CONFIG_GPIO_LED
2319 to include the gpio_led driver in the U-Boot binary.
2321 CONFIG_GPIO_LED_INVERTED_TABLE
2322 Some GPIO connected LEDs may have inverted polarity in which
2323 case the GPIO high value corresponds to LED off state and
2324 GPIO low value corresponds to LED on state.
2325 In such cases CONFIG_GPIO_LED_INVERTED_TABLE may be defined
2326 with a list of GPIO LEDs that have inverted polarity.
2328 - CAN Support: CONFIG_CAN_DRIVER
2330 Defining CONFIG_CAN_DRIVER enables CAN driver support
2331 on those systems that support this (optional)
2332 feature, like the TQM8xxL modules.
2334 - I2C Support: CONFIG_SYS_I2C
2336 This enable the NEW i2c subsystem, and will allow you to use
2337 i2c commands at the u-boot command line (as long as you set
2338 CONFIG_CMD_I2C in CONFIG_COMMANDS) and communicate with i2c
2339 based realtime clock chips or other i2c devices. See
2340 common/cmd_i2c.c for a description of the command line
2343 ported i2c driver to the new framework:
2344 - drivers/i2c/soft_i2c.c:
2345 - activate first bus with CONFIG_SYS_I2C_SOFT define
2346 CONFIG_SYS_I2C_SOFT_SPEED and CONFIG_SYS_I2C_SOFT_SLAVE
2347 for defining speed and slave address
2348 - activate second bus with I2C_SOFT_DECLARATIONS2 define
2349 CONFIG_SYS_I2C_SOFT_SPEED_2 and CONFIG_SYS_I2C_SOFT_SLAVE_2
2350 for defining speed and slave address
2351 - activate third bus with I2C_SOFT_DECLARATIONS3 define
2352 CONFIG_SYS_I2C_SOFT_SPEED_3 and CONFIG_SYS_I2C_SOFT_SLAVE_3
2353 for defining speed and slave address
2354 - activate fourth bus with I2C_SOFT_DECLARATIONS4 define
2355 CONFIG_SYS_I2C_SOFT_SPEED_4 and CONFIG_SYS_I2C_SOFT_SLAVE_4
2356 for defining speed and slave address
2358 - drivers/i2c/fsl_i2c.c:
2359 - activate i2c driver with CONFIG_SYS_I2C_FSL
2360 define CONFIG_SYS_FSL_I2C_OFFSET for setting the register
2361 offset CONFIG_SYS_FSL_I2C_SPEED for the i2c speed and
2362 CONFIG_SYS_FSL_I2C_SLAVE for the slave addr of the first
2364 - If your board supports a second fsl i2c bus, define
2365 CONFIG_SYS_FSL_I2C2_OFFSET for the register offset
2366 CONFIG_SYS_FSL_I2C2_SPEED for the speed and
2367 CONFIG_SYS_FSL_I2C2_SLAVE for the slave address of the
2370 - drivers/i2c/tegra_i2c.c:
2371 - activate this driver with CONFIG_SYS_I2C_TEGRA
2372 - This driver adds 4 i2c buses with a fix speed from
2373 100000 and the slave addr 0!
2375 - drivers/i2c/ppc4xx_i2c.c
2376 - activate this driver with CONFIG_SYS_I2C_PPC4XX
2377 - CONFIG_SYS_I2C_PPC4XX_CH0 activate hardware channel 0
2378 - CONFIG_SYS_I2C_PPC4XX_CH1 activate hardware channel 1
2380 - drivers/i2c/i2c_mxc.c
2381 - activate this driver with CONFIG_SYS_I2C_MXC
2382 - define speed for bus 1 with CONFIG_SYS_MXC_I2C1_SPEED
2383 - define slave for bus 1 with CONFIG_SYS_MXC_I2C1_SLAVE
2384 - define speed for bus 2 with CONFIG_SYS_MXC_I2C2_SPEED
2385 - define slave for bus 2 with CONFIG_SYS_MXC_I2C2_SLAVE
2386 - define speed for bus 3 with CONFIG_SYS_MXC_I2C3_SPEED
2387 - define slave for bus 3 with CONFIG_SYS_MXC_I2C3_SLAVE
2388 If those defines are not set, default value is 100000
2389 for speed, and 0 for slave.
2391 - drivers/i2c/rcar_i2c.c:
2392 - activate this driver with CONFIG_SYS_I2C_RCAR
2393 - This driver adds 4 i2c buses
2395 - CONFIG_SYS_RCAR_I2C0_BASE for setting the register channel 0
2396 - CONFIG_SYS_RCAR_I2C0_SPEED for for the speed channel 0
2397 - CONFIG_SYS_RCAR_I2C1_BASE for setting the register channel 1
2398 - CONFIG_SYS_RCAR_I2C1_SPEED for for the speed channel 1
2399 - CONFIG_SYS_RCAR_I2C2_BASE for setting the register channel 2
2400 - CONFIG_SYS_RCAR_I2C2_SPEED for for the speed channel 2
2401 - CONFIG_SYS_RCAR_I2C3_BASE for setting the register channel 3
2402 - CONFIG_SYS_RCAR_I2C3_SPEED for for the speed channel 3
2403 - CONFIF_SYS_RCAR_I2C_NUM_CONTROLLERS for number of i2c buses
2405 - drivers/i2c/sh_i2c.c:
2406 - activate this driver with CONFIG_SYS_I2C_SH
2407 - This driver adds from 2 to 5 i2c buses
2409 - CONFIG_SYS_I2C_SH_BASE0 for setting the register channel 0
2410 - CONFIG_SYS_I2C_SH_SPEED0 for for the speed channel 0
2411 - CONFIG_SYS_I2C_SH_BASE1 for setting the register channel 1
2412 - CONFIG_SYS_I2C_SH_SPEED1 for for the speed channel 1
2413 - CONFIG_SYS_I2C_SH_BASE2 for setting the register channel 2
2414 - CONFIG_SYS_I2C_SH_SPEED2 for for the speed channel 2
2415 - CONFIG_SYS_I2C_SH_BASE3 for setting the register channel 3
2416 - CONFIG_SYS_I2C_SH_SPEED3 for for the speed channel 3
2417 - CONFIG_SYS_I2C_SH_BASE4 for setting the register channel 4
2418 - CONFIG_SYS_I2C_SH_SPEED4 for for the speed channel 4
2419 - CONFIG_SYS_I2C_SH_BASE5 for setting the register channel 5
2420 - CONFIG_SYS_I2C_SH_SPEED5 for for the speed channel 5
2421 - CONFIG_SYS_I2C_SH_NUM_CONTROLLERS for number of i2c buses
2423 - drivers/i2c/omap24xx_i2c.c
2424 - activate this driver with CONFIG_SYS_I2C_OMAP24XX
2425 - CONFIG_SYS_OMAP24_I2C_SPEED speed channel 0
2426 - CONFIG_SYS_OMAP24_I2C_SLAVE slave addr channel 0
2427 - CONFIG_SYS_OMAP24_I2C_SPEED1 speed channel 1
2428 - CONFIG_SYS_OMAP24_I2C_SLAVE1 slave addr channel 1
2429 - CONFIG_SYS_OMAP24_I2C_SPEED2 speed channel 2
2430 - CONFIG_SYS_OMAP24_I2C_SLAVE2 slave addr channel 2
2431 - CONFIG_SYS_OMAP24_I2C_SPEED3 speed channel 3
2432 - CONFIG_SYS_OMAP24_I2C_SLAVE3 slave addr channel 3
2433 - CONFIG_SYS_OMAP24_I2C_SPEED4 speed channel 4
2434 - CONFIG_SYS_OMAP24_I2C_SLAVE4 slave addr channel 4
2436 - drivers/i2c/zynq_i2c.c
2437 - activate this driver with CONFIG_SYS_I2C_ZYNQ
2438 - set CONFIG_SYS_I2C_ZYNQ_SPEED for speed setting
2439 - set CONFIG_SYS_I2C_ZYNQ_SLAVE for slave addr
2441 - drivers/i2c/s3c24x0_i2c.c:
2442 - activate this driver with CONFIG_SYS_I2C_S3C24X0
2443 - This driver adds i2c buses (11 for Exynos5250, Exynos5420
2444 9 i2c buses for Exynos4 and 1 for S3C24X0 SoCs from Samsung)
2445 with a fix speed from 100000 and the slave addr 0!
2447 - drivers/i2c/ihs_i2c.c
2448 - activate this driver with CONFIG_SYS_I2C_IHS
2449 - CONFIG_SYS_I2C_IHS_CH0 activate hardware channel 0
2450 - CONFIG_SYS_I2C_IHS_SPEED_0 speed channel 0
2451 - CONFIG_SYS_I2C_IHS_SLAVE_0 slave addr channel 0
2452 - CONFIG_SYS_I2C_IHS_CH1 activate hardware channel 1
2453 - CONFIG_SYS_I2C_IHS_SPEED_1 speed channel 1
2454 - CONFIG_SYS_I2C_IHS_SLAVE_1 slave addr channel 1
2455 - CONFIG_SYS_I2C_IHS_CH2 activate hardware channel 2
2456 - CONFIG_SYS_I2C_IHS_SPEED_2 speed channel 2
2457 - CONFIG_SYS_I2C_IHS_SLAVE_2 slave addr channel 2
2458 - CONFIG_SYS_I2C_IHS_CH3 activate hardware channel 3
2459 - CONFIG_SYS_I2C_IHS_SPEED_3 speed channel 3
2460 - CONFIG_SYS_I2C_IHS_SLAVE_3 slave addr channel 3
2464 CONFIG_SYS_NUM_I2C_BUSES
2465 Hold the number of i2c buses you want to use. If you
2466 don't use/have i2c muxes on your i2c bus, this
2467 is equal to CONFIG_SYS_NUM_I2C_ADAPTERS, and you can
2470 CONFIG_SYS_I2C_DIRECT_BUS
2471 define this, if you don't use i2c muxes on your hardware.
2472 if CONFIG_SYS_I2C_MAX_HOPS is not defined or == 0 you can
2475 CONFIG_SYS_I2C_MAX_HOPS
2476 define how many muxes are maximal consecutively connected
2477 on one i2c bus. If you not use i2c muxes, omit this
2480 CONFIG_SYS_I2C_BUSES
2481 hold a list of buses you want to use, only used if
2482 CONFIG_SYS_I2C_DIRECT_BUS is not defined, for example
2483 a board with CONFIG_SYS_I2C_MAX_HOPS = 1 and
2484 CONFIG_SYS_NUM_I2C_BUSES = 9:
2486 CONFIG_SYS_I2C_BUSES {{0, {I2C_NULL_HOP}}, \
2487 {0, {{I2C_MUX_PCA9547, 0x70, 1}}}, \
2488 {0, {{I2C_MUX_PCA9547, 0x70, 2}}}, \
2489 {0, {{I2C_MUX_PCA9547, 0x70, 3}}}, \
2490 {0, {{I2C_MUX_PCA9547, 0x70, 4}}}, \
2491 {0, {{I2C_MUX_PCA9547, 0x70, 5}}}, \
2492 {1, {I2C_NULL_HOP}}, \
2493 {1, {{I2C_MUX_PCA9544, 0x72, 1}}}, \
2494 {1, {{I2C_MUX_PCA9544, 0x72, 2}}}, \
2498 bus 0 on adapter 0 without a mux
2499 bus 1 on adapter 0 with a PCA9547 on address 0x70 port 1
2500 bus 2 on adapter 0 with a PCA9547 on address 0x70 port 2
2501 bus 3 on adapter 0 with a PCA9547 on address 0x70 port 3
2502 bus 4 on adapter 0 with a PCA9547 on address 0x70 port 4
2503 bus 5 on adapter 0 with a PCA9547 on address 0x70 port 5
2504 bus 6 on adapter 1 without a mux
2505 bus 7 on adapter 1 with a PCA9544 on address 0x72 port 1
2506 bus 8 on adapter 1 with a PCA9544 on address 0x72 port 2
2508 If you do not have i2c muxes on your board, omit this define.
2510 - Legacy I2C Support: CONFIG_HARD_I2C
2512 NOTE: It is intended to move drivers to CONFIG_SYS_I2C which
2513 provides the following compelling advantages:
2515 - more than one i2c adapter is usable
2516 - approved multibus support
2517 - better i2c mux support
2519 ** Please consider updating your I2C driver now. **
2521 These enable legacy I2C serial bus commands. Defining
2522 CONFIG_HARD_I2C will include the appropriate I2C driver
2523 for the selected CPU.
2525 This will allow you to use i2c commands at the u-boot
2526 command line (as long as you set CONFIG_CMD_I2C in
2527 CONFIG_COMMANDS) and communicate with i2c based realtime
2528 clock chips. See common/cmd_i2c.c for a description of the
2529 command line interface.
2531 CONFIG_HARD_I2C selects a hardware I2C controller.
2533 There are several other quantities that must also be
2534 defined when you define CONFIG_HARD_I2C.
2536 In both cases you will need to define CONFIG_SYS_I2C_SPEED
2537 to be the frequency (in Hz) at which you wish your i2c bus
2538 to run and CONFIG_SYS_I2C_SLAVE to be the address of this node (ie
2539 the CPU's i2c node address).
2541 Now, the u-boot i2c code for the mpc8xx
2542 (arch/powerpc/cpu/mpc8xx/i2c.c) sets the CPU up as a master node
2543 and so its address should therefore be cleared to 0 (See,
2544 eg, MPC823e User's Manual p.16-473). So, set
2545 CONFIG_SYS_I2C_SLAVE to 0.
2547 CONFIG_SYS_I2C_INIT_MPC5XXX
2549 When a board is reset during an i2c bus transfer
2550 chips might think that the current transfer is still
2551 in progress. Reset the slave devices by sending start
2552 commands until the slave device responds.
2554 That's all that's required for CONFIG_HARD_I2C.
2556 If you use the software i2c interface (CONFIG_SYS_I2C_SOFT)
2557 then the following macros need to be defined (examples are
2558 from include/configs/lwmon.h):
2562 (Optional). Any commands necessary to enable the I2C
2563 controller or configure ports.
2565 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
2569 (Only for MPC8260 CPU). The I/O port to use (the code
2570 assumes both bits are on the same port). Valid values
2571 are 0..3 for ports A..D.
2575 The code necessary to make the I2C data line active
2576 (driven). If the data line is open collector, this
2579 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
2583 The code necessary to make the I2C data line tri-stated
2584 (inactive). If the data line is open collector, this
2587 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
2591 Code that returns true if the I2C data line is high,
2594 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
2598 If <bit> is true, sets the I2C data line high. If it
2599 is false, it clears it (low).
2601 eg: #define I2C_SDA(bit) \
2602 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
2603 else immr->im_cpm.cp_pbdat &= ~PB_SDA
2607 If <bit> is true, sets the I2C clock line high. If it
2608 is false, it clears it (low).
2610 eg: #define I2C_SCL(bit) \
2611 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
2612 else immr->im_cpm.cp_pbdat &= ~PB_SCL
2616 This delay is invoked four times per clock cycle so this
2617 controls the rate of data transfer. The data rate thus
2618 is 1 / (I2C_DELAY * 4). Often defined to be something
2621 #define I2C_DELAY udelay(2)
2623 CONFIG_SOFT_I2C_GPIO_SCL / CONFIG_SOFT_I2C_GPIO_SDA
2625 If your arch supports the generic GPIO framework (asm/gpio.h),
2626 then you may alternatively define the two GPIOs that are to be
2627 used as SCL / SDA. Any of the previous I2C_xxx macros will
2628 have GPIO-based defaults assigned to them as appropriate.
2630 You should define these to the GPIO value as given directly to
2631 the generic GPIO functions.
2633 CONFIG_SYS_I2C_INIT_BOARD
2635 When a board is reset during an i2c bus transfer
2636 chips might think that the current transfer is still
2637 in progress. On some boards it is possible to access
2638 the i2c SCLK line directly, either by using the
2639 processor pin as a GPIO or by having a second pin
2640 connected to the bus. If this option is defined a
2641 custom i2c_init_board() routine in boards/xxx/board.c
2642 is run early in the boot sequence.
2644 CONFIG_SYS_I2C_BOARD_LATE_INIT
2646 An alternative to CONFIG_SYS_I2C_INIT_BOARD. If this option is
2647 defined a custom i2c_board_late_init() routine in
2648 boards/xxx/board.c is run AFTER the operations in i2c_init()
2649 is completed. This callpoint can be used to unreset i2c bus
2650 using CPU i2c controller register accesses for CPUs whose i2c
2651 controller provide such a method. It is called at the end of
2652 i2c_init() to allow i2c_init operations to setup the i2c bus
2653 controller on the CPU (e.g. setting bus speed & slave address).
2655 CONFIG_I2CFAST (PPC405GP|PPC405EP only)
2657 This option enables configuration of bi_iic_fast[] flags
2658 in u-boot bd_info structure based on u-boot environment
2659 variable "i2cfast". (see also i2cfast)
2661 CONFIG_I2C_MULTI_BUS
2663 This option allows the use of multiple I2C buses, each of which
2664 must have a controller. At any point in time, only one bus is
2665 active. To switch to a different bus, use the 'i2c dev' command.
2666 Note that bus numbering is zero-based.
2668 CONFIG_SYS_I2C_NOPROBES
2670 This option specifies a list of I2C devices that will be skipped
2671 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS
2672 is set, specify a list of bus-device pairs. Otherwise, specify
2673 a 1D array of device addresses
2676 #undef CONFIG_I2C_MULTI_BUS
2677 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68}
2679 will skip addresses 0x50 and 0x68 on a board with one I2C bus
2681 #define CONFIG_I2C_MULTI_BUS
2682 #define CONFIG_SYS_I2C_MULTI_NOPROBES {{0,0x50},{0,0x68},{1,0x54}}
2684 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1
2686 CONFIG_SYS_SPD_BUS_NUM
2688 If defined, then this indicates the I2C bus number for DDR SPD.
2689 If not defined, then U-Boot assumes that SPD is on I2C bus 0.
2691 CONFIG_SYS_RTC_BUS_NUM
2693 If defined, then this indicates the I2C bus number for the RTC.
2694 If not defined, then U-Boot assumes that RTC is on I2C bus 0.
2696 CONFIG_SYS_DTT_BUS_NUM
2698 If defined, then this indicates the I2C bus number for the DTT.
2699 If not defined, then U-Boot assumes that DTT is on I2C bus 0.
2701 CONFIG_SYS_I2C_DTT_ADDR:
2703 If defined, specifies the I2C address of the DTT device.
2704 If not defined, then U-Boot uses predefined value for
2705 specified DTT device.
2707 CONFIG_SOFT_I2C_READ_REPEATED_START
2709 defining this will force the i2c_read() function in
2710 the soft_i2c driver to perform an I2C repeated start
2711 between writing the address pointer and reading the
2712 data. If this define is omitted the default behaviour
2713 of doing a stop-start sequence will be used. Most I2C
2714 devices can use either method, but some require one or
2717 - SPI Support: CONFIG_SPI
2719 Enables SPI driver (so far only tested with
2720 SPI EEPROM, also an instance works with Crystal A/D and
2721 D/As on the SACSng board)
2725 Enables the driver for SPI controller on SuperH. Currently
2726 only SH7757 is supported.
2730 Enables extended (16-bit) SPI EEPROM addressing.
2731 (symmetrical to CONFIG_I2C_X)
2735 Enables a software (bit-bang) SPI driver rather than
2736 using hardware support. This is a general purpose
2737 driver that only requires three general I/O port pins
2738 (two outputs, one input) to function. If this is
2739 defined, the board configuration must define several
2740 SPI configuration items (port pins to use, etc). For
2741 an example, see include/configs/sacsng.h.
2745 Enables a hardware SPI driver for general-purpose reads
2746 and writes. As with CONFIG_SOFT_SPI, the board configuration
2747 must define a list of chip-select function pointers.
2748 Currently supported on some MPC8xxx processors. For an
2749 example, see include/configs/mpc8349emds.h.
2753 Enables the driver for the SPI controllers on i.MX and MXC
2754 SoCs. Currently i.MX31/35/51 are supported.
2756 CONFIG_SYS_SPI_MXC_WAIT
2757 Timeout for waiting until spi transfer completed.
2758 default: (CONFIG_SYS_HZ/100) /* 10 ms */
2760 - FPGA Support: CONFIG_FPGA
2762 Enables FPGA subsystem.
2764 CONFIG_FPGA_<vendor>
2766 Enables support for specific chip vendors.
2769 CONFIG_FPGA_<family>
2771 Enables support for FPGA family.
2772 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX)
2776 Specify the number of FPGA devices to support.
2778 CONFIG_CMD_FPGA_LOADMK
2780 Enable support for fpga loadmk command
2782 CONFIG_CMD_FPGA_LOADP
2784 Enable support for fpga loadp command - load partial bitstream
2786 CONFIG_CMD_FPGA_LOADBP
2788 Enable support for fpga loadbp command - load partial bitstream
2791 CONFIG_SYS_FPGA_PROG_FEEDBACK
2793 Enable printing of hash marks during FPGA configuration.
2795 CONFIG_SYS_FPGA_CHECK_BUSY
2797 Enable checks on FPGA configuration interface busy
2798 status by the configuration function. This option
2799 will require a board or device specific function to
2804 If defined, a function that provides delays in the FPGA
2805 configuration driver.
2807 CONFIG_SYS_FPGA_CHECK_CTRLC
2808 Allow Control-C to interrupt FPGA configuration
2810 CONFIG_SYS_FPGA_CHECK_ERROR
2812 Check for configuration errors during FPGA bitfile
2813 loading. For example, abort during Virtex II
2814 configuration if the INIT_B line goes low (which
2815 indicated a CRC error).
2817 CONFIG_SYS_FPGA_WAIT_INIT
2819 Maximum time to wait for the INIT_B line to de-assert
2820 after PROB_B has been de-asserted during a Virtex II
2821 FPGA configuration sequence. The default time is 500
2824 CONFIG_SYS_FPGA_WAIT_BUSY
2826 Maximum time to wait for BUSY to de-assert during
2827 Virtex II FPGA configuration. The default is 5 ms.
2829 CONFIG_SYS_FPGA_WAIT_CONFIG
2831 Time to wait after FPGA configuration. The default is
2834 - Configuration Management:
2837 Some SoCs need special image types (e.g. U-Boot binary
2838 with a special header) as build targets. By defining
2839 CONFIG_BUILD_TARGET in the SoC / board header, this
2840 special image will be automatically built upon calling
2845 If defined, this string will be added to the U-Boot
2846 version information (U_BOOT_VERSION)
2848 - Vendor Parameter Protection:
2850 U-Boot considers the values of the environment
2851 variables "serial#" (Board Serial Number) and
2852 "ethaddr" (Ethernet Address) to be parameters that
2853 are set once by the board vendor / manufacturer, and
2854 protects these variables from casual modification by
2855 the user. Once set, these variables are read-only,
2856 and write or delete attempts are rejected. You can
2857 change this behaviour:
2859 If CONFIG_ENV_OVERWRITE is #defined in your config
2860 file, the write protection for vendor parameters is
2861 completely disabled. Anybody can change or delete
2864 Alternatively, if you #define _both_ CONFIG_ETHADDR
2865 _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
2866 Ethernet address is installed in the environment,
2867 which can be changed exactly ONCE by the user. [The
2868 serial# is unaffected by this, i. e. it remains
2871 The same can be accomplished in a more flexible way
2872 for any variable by configuring the type of access
2873 to allow for those variables in the ".flags" variable
2874 or define CONFIG_ENV_FLAGS_LIST_STATIC.
2879 Define this variable to enable the reservation of
2880 "protected RAM", i. e. RAM which is not overwritten
2881 by U-Boot. Define CONFIG_PRAM to hold the number of
2882 kB you want to reserve for pRAM. You can overwrite
2883 this default value by defining an environment
2884 variable "pram" to the number of kB you want to
2885 reserve. Note that the board info structure will
2886 still show the full amount of RAM. If pRAM is
2887 reserved, a new environment variable "mem" will
2888 automatically be defined to hold the amount of
2889 remaining RAM in a form that can be passed as boot
2890 argument to Linux, for instance like that:
2892 setenv bootargs ... mem=\${mem}
2895 This way you can tell Linux not to use this memory,
2896 either, which results in a memory region that will
2897 not be affected by reboots.
2899 *WARNING* If your board configuration uses automatic
2900 detection of the RAM size, you must make sure that
2901 this memory test is non-destructive. So far, the
2902 following board configurations are known to be
2905 IVMS8, IVML24, SPD8xx, TQM8xxL,
2906 HERMES, IP860, RPXlite, LWMON,
2909 - Access to physical memory region (> 4GB)
2910 Some basic support is provided for operations on memory not
2911 normally accessible to U-Boot - e.g. some architectures
2912 support access to more than 4GB of memory on 32-bit
2913 machines using physical address extension or similar.
2914 Define CONFIG_PHYSMEM to access this basic support, which
2915 currently only supports clearing the memory.
2920 Define this variable to stop the system in case of a
2921 fatal error, so that you have to reset it manually.
2922 This is probably NOT a good idea for an embedded
2923 system where you want the system to reboot
2924 automatically as fast as possible, but it may be
2925 useful during development since you can try to debug
2926 the conditions that lead to the situation.
2928 CONFIG_NET_RETRY_COUNT
2930 This variable defines the number of retries for
2931 network operations like ARP, RARP, TFTP, or BOOTP
2932 before giving up the operation. If not defined, a
2933 default value of 5 is used.
2937 Timeout waiting for an ARP reply in milliseconds.
2941 Timeout in milliseconds used in NFS protocol.
2942 If you encounter "ERROR: Cannot umount" in nfs command,
2943 try longer timeout such as
2944 #define CONFIG_NFS_TIMEOUT 10000UL
2946 - Command Interpreter:
2947 CONFIG_AUTO_COMPLETE
2949 Enable auto completion of commands using TAB.
2951 CONFIG_SYS_PROMPT_HUSH_PS2
2953 This defines the secondary prompt string, which is
2954 printed when the command interpreter needs more input
2955 to complete a command. Usually "> ".
2959 In the current implementation, the local variables
2960 space and global environment variables space are
2961 separated. Local variables are those you define by
2962 simply typing `name=value'. To access a local
2963 variable later on, you have write `$name' or
2964 `${name}'; to execute the contents of a variable
2965 directly type `$name' at the command prompt.
2967 Global environment variables are those you use
2968 setenv/printenv to work with. To run a command stored
2969 in such a variable, you need to use the run command,
2970 and you must not use the '$' sign to access them.
2972 To store commands and special characters in a
2973 variable, please use double quotation marks
2974 surrounding the whole text of the variable, instead
2975 of the backslashes before semicolons and special
2978 - Command Line Editing and History:
2979 CONFIG_CMDLINE_EDITING
2981 Enable editing and History functions for interactive
2982 command line input operations
2984 - Default Environment:
2985 CONFIG_EXTRA_ENV_SETTINGS
2987 Define this to contain any number of null terminated
2988 strings (variable = value pairs) that will be part of
2989 the default environment compiled into the boot image.
2991 For example, place something like this in your
2992 board's config file:
2994 #define CONFIG_EXTRA_ENV_SETTINGS \
2998 Warning: This method is based on knowledge about the
2999 internal format how the environment is stored by the
3000 U-Boot code. This is NOT an official, exported
3001 interface! Although it is unlikely that this format
3002 will change soon, there is no guarantee either.
3003 You better know what you are doing here.
3005 Note: overly (ab)use of the default environment is
3006 discouraged. Make sure to check other ways to preset
3007 the environment like the "source" command or the
3010 CONFIG_ENV_VARS_UBOOT_CONFIG
3012 Define this in order to add variables describing the
3013 U-Boot build configuration to the default environment.
3014 These will be named arch, cpu, board, vendor, and soc.
3016 Enabling this option will cause the following to be defined:
3024 CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG
3026 Define this in order to add variables describing certain
3027 run-time determined information about the hardware to the
3028 environment. These will be named board_name, board_rev.
3030 CONFIG_DELAY_ENVIRONMENT
3032 Normally the environment is loaded when the board is
3033 initialised so that it is available to U-Boot. This inhibits
3034 that so that the environment is not available until
3035 explicitly loaded later by U-Boot code. With CONFIG_OF_CONTROL
3036 this is instead controlled by the value of
3037 /config/load-environment.
3039 - DataFlash Support:
3040 CONFIG_HAS_DATAFLASH
3042 Defining this option enables DataFlash features and
3043 allows to read/write in Dataflash via the standard
3046 - Serial Flash support
3049 Defining this option enables SPI flash commands
3050 'sf probe/read/write/erase/update'.
3052 Usage requires an initial 'probe' to define the serial
3053 flash parameters, followed by read/write/erase/update
3056 The following defaults may be provided by the platform
3057 to handle the common case when only a single serial
3058 flash is present on the system.
3060 CONFIG_SF_DEFAULT_BUS Bus identifier
3061 CONFIG_SF_DEFAULT_CS Chip-select
3062 CONFIG_SF_DEFAULT_MODE (see include/spi.h)
3063 CONFIG_SF_DEFAULT_SPEED in Hz
3067 Define this option to include a destructive SPI flash
3070 CONFIG_SPI_FLASH_BAR Ban/Extended Addr Reg
3072 Define this option to use the Bank addr/Extended addr
3073 support on SPI flashes which has size > 16Mbytes.
3075 CONFIG_SF_DUAL_FLASH Dual flash memories
3077 Define this option to use dual flash support where two flash
3078 memories can be connected with a given cs line.
3079 Currently Xilinx Zynq qspi supports these type of connections.
3081 CONFIG_SYS_SPI_ST_ENABLE_WP_PIN
3082 enable the W#/Vpp signal to disable writing to the status
3083 register on ST MICRON flashes like the N25Q128.
3084 The status register write enable/disable bit, combined with
3085 the W#/VPP signal provides hardware data protection for the
3086 device as follows: When the enable/disable bit is set to 1,
3087 and the W#/VPP signal is driven LOW, the status register
3088 nonvolatile bits become read-only and the WRITE STATUS REGISTER
3089 operation will not execute. The only way to exit this
3090 hardware-protected mode is to drive W#/VPP HIGH.
3092 - SystemACE Support:
3095 Adding this option adds support for Xilinx SystemACE
3096 chips attached via some sort of local bus. The address
3097 of the chip must also be defined in the
3098 CONFIG_SYS_SYSTEMACE_BASE macro. For example:
3100 #define CONFIG_SYSTEMACE
3101 #define CONFIG_SYS_SYSTEMACE_BASE 0xf0000000
3103 When SystemACE support is added, the "ace" device type
3104 becomes available to the fat commands, i.e. fatls.
3106 - TFTP Fixed UDP Port:
3109 If this is defined, the environment variable tftpsrcp
3110 is used to supply the TFTP UDP source port value.
3111 If tftpsrcp isn't defined, the normal pseudo-random port
3112 number generator is used.
3114 Also, the environment variable tftpdstp is used to supply
3115 the TFTP UDP destination port value. If tftpdstp isn't
3116 defined, the normal port 69 is used.
3118 The purpose for tftpsrcp is to allow a TFTP server to
3119 blindly start the TFTP transfer using the pre-configured
3120 target IP address and UDP port. This has the effect of
3121 "punching through" the (Windows XP) firewall, allowing
3122 the remainder of the TFTP transfer to proceed normally.
3123 A better solution is to properly configure the firewall,
3124 but sometimes that is not allowed.
3129 This enables a generic 'hash' command which can produce
3130 hashes / digests from a few algorithms (e.g. SHA1, SHA256).
3134 Enable the hash verify command (hash -v). This adds to code
3137 CONFIG_SHA1 - This option enables support of hashing using SHA1
3138 algorithm. The hash is calculated in software.
3139 CONFIG_SHA256 - This option enables support of hashing using
3140 SHA256 algorithm. The hash is calculated in software.
3141 CONFIG_SHA_HW_ACCEL - This option enables hardware acceleration
3142 for SHA1/SHA256 hashing.
3143 This affects the 'hash' command and also the
3144 hash_lookup_algo() function.
3145 CONFIG_SHA_PROG_HW_ACCEL - This option enables
3146 hardware-acceleration for SHA1/SHA256 progressive hashing.
3147 Data can be streamed in a block at a time and the hashing
3148 is performed in hardware.
3150 Note: There is also a sha1sum command, which should perhaps
3151 be deprecated in favour of 'hash sha1'.
3153 - Freescale i.MX specific commands:
3154 CONFIG_CMD_HDMIDETECT
3155 This enables 'hdmidet' command which returns true if an
3156 HDMI monitor is detected. This command is i.MX 6 specific.
3159 This enables the 'bmode' (bootmode) command for forcing
3160 a boot from specific media.
3162 This is useful for forcing the ROM's usb downloader to
3163 activate upon a watchdog reset which is nice when iterating
3164 on U-Boot. Using the reset button or running bmode normal
3165 will set it back to normal. This command currently
3166 supports i.MX53 and i.MX6.
3171 This enables the RSA algorithm used for FIT image verification
3172 in U-Boot. See doc/uImage.FIT/signature.txt for more information.
3174 The Modular Exponentiation algorithm in RSA is implemented using
3175 driver model. So CONFIG_DM needs to be enabled by default for this
3176 library to function.
3178 The signing part is build into mkimage regardless of this
3179 option. The software based modular exponentiation is built into
3180 mkimage irrespective of this option.
3182 - bootcount support:
3183 CONFIG_BOOTCOUNT_LIMIT
3185 This enables the bootcounter support, see:
3186 http://www.denx.de/wiki/DULG/UBootBootCountLimit
3189 enable special bootcounter support on at91sam9xe based boards.
3191 enable special bootcounter support on blackfin based boards.
3193 enable special bootcounter support on da850 based boards.
3194 CONFIG_BOOTCOUNT_RAM
3195 enable support for the bootcounter in RAM
3196 CONFIG_BOOTCOUNT_I2C
3197 enable support for the bootcounter on an i2c (like RTC) device.
3198 CONFIG_SYS_I2C_RTC_ADDR = i2c chip address
3199 CONFIG_SYS_BOOTCOUNT_ADDR = i2c addr which is used for
3201 CONFIG_BOOTCOUNT_ALEN = address len
3203 - Show boot progress:
3204 CONFIG_SHOW_BOOT_PROGRESS
3206 Defining this option allows to add some board-
3207 specific code (calling a user-provided function
3208 "show_boot_progress(int)") that enables you to show
3209 the system's boot progress on some display (for
3210 example, some LED's) on your board. At the moment,
3211 the following checkpoints are implemented:
3213 - Detailed boot stage timing
3215 Define this option to get detailed timing of each stage
3216 of the boot process.
3218 CONFIG_BOOTSTAGE_USER_COUNT
3219 This is the number of available user bootstage records.
3220 Each time you call bootstage_mark(BOOTSTAGE_ID_ALLOC, ...)
3221 a new ID will be allocated from this stash. If you exceed
3222 the limit, recording will stop.
3224 CONFIG_BOOTSTAGE_REPORT
3225 Define this to print a report before boot, similar to this:
3227 Timer summary in microseconds:
3230 3,575,678 3,575,678 board_init_f start
3231 3,575,695 17 arch_cpu_init A9
3232 3,575,777 82 arch_cpu_init done
3233 3,659,598 83,821 board_init_r start
3234 3,910,375 250,777 main_loop
3235 29,916,167 26,005,792 bootm_start
3236 30,361,327 445,160 start_kernel
3238 CONFIG_CMD_BOOTSTAGE
3239 Add a 'bootstage' command which supports printing a report
3240 and un/stashing of bootstage data.
3242 CONFIG_BOOTSTAGE_FDT
3243 Stash the bootstage information in the FDT. A root 'bootstage'
3244 node is created with each bootstage id as a child. Each child
3245 has a 'name' property and either 'mark' containing the
3246 mark time in microsecond, or 'accum' containing the
3247 accumulated time for that bootstage id in microseconds.
3252 name = "board_init_f";
3261 Code in the Linux kernel can find this in /proc/devicetree.
3263 Legacy uImage format:
3266 1 common/cmd_bootm.c before attempting to boot an image
3267 -1 common/cmd_bootm.c Image header has bad magic number
3268 2 common/cmd_bootm.c Image header has correct magic number
3269 -2 common/cmd_bootm.c Image header has bad checksum
3270 3 common/cmd_bootm.c Image header has correct checksum
3271 -3 common/cmd_bootm.c Image data has bad checksum
3272 4 common/cmd_bootm.c Image data has correct checksum
3273 -4 common/cmd_bootm.c Image is for unsupported architecture
3274 5 common/cmd_bootm.c Architecture check OK
3275 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi)
3276 6 common/cmd_bootm.c Image Type check OK
3277 -6 common/cmd_bootm.c gunzip uncompression error
3278 -7 common/cmd_bootm.c Unimplemented compression type
3279 7 common/cmd_bootm.c Uncompression OK
3280 8 common/cmd_bootm.c No uncompress/copy overwrite error
3281 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX)
3283 9 common/image.c Start initial ramdisk verification
3284 -10 common/image.c Ramdisk header has bad magic number
3285 -11 common/image.c Ramdisk header has bad checksum
3286 10 common/image.c Ramdisk header is OK
3287 -12 common/image.c Ramdisk data has bad checksum
3288 11 common/image.c Ramdisk data has correct checksum
3289 12 common/image.c Ramdisk verification complete, start loading
3290 -13 common/image.c Wrong Image Type (not PPC Linux ramdisk)
3291 13 common/image.c Start multifile image verification
3292 14 common/image.c No initial ramdisk, no multifile, continue.
3294 15 arch/<arch>/lib/bootm.c All preparation done, transferring control to OS
3296 -30 arch/powerpc/lib/board.c Fatal error, hang the system
3297 -31 post/post.c POST test failed, detected by post_output_backlog()
3298 -32 post/post.c POST test failed, detected by post_run_single()
3300 34 common/cmd_doc.c before loading a Image from a DOC device
3301 -35 common/cmd_doc.c Bad usage of "doc" command
3302 35 common/cmd_doc.c correct usage of "doc" command
3303 -36 common/cmd_doc.c No boot device
3304 36 common/cmd_doc.c correct boot device
3305 -37 common/cmd_doc.c Unknown Chip ID on boot device
3306 37 common/cmd_doc.c correct chip ID found, device available
3307 -38 common/cmd_doc.c Read Error on boot device
3308 38 common/cmd_doc.c reading Image header from DOC device OK
3309 -39 common/cmd_doc.c Image header has bad magic number
3310 39 common/cmd_doc.c Image header has correct magic number
3311 -40 common/cmd_doc.c Error reading Image from DOC device
3312 40 common/cmd_doc.c Image header has correct magic number
3313 41 common/cmd_ide.c before loading a Image from a IDE device
3314 -42 common/cmd_ide.c Bad usage of "ide" command
3315 42 common/cmd_ide.c correct usage of "ide" command
3316 -43 common/cmd_ide.c No boot device
3317 43 common/cmd_ide.c boot device found
3318 -44 common/cmd_ide.c Device not available
3319 44 common/cmd_ide.c Device available
3320 -45 common/cmd_ide.c wrong partition selected
3321 45 common/cmd_ide.c partition selected
3322 -46 common/cmd_ide.c Unknown partition table
3323 46 common/cmd_ide.c valid partition table found
3324 -47 common/cmd_ide.c Invalid partition type
3325 47 common/cmd_ide.c correct partition type
3326 -48 common/cmd_ide.c Error reading Image Header on boot device
3327 48 common/cmd_ide.c reading Image Header from IDE device OK
3328 -49 common/cmd_ide.c Image header has bad magic number
3329 49 common/cmd_ide.c Image header has correct magic number
3330 -50 common/cmd_ide.c Image header has bad checksum
3331 50 common/cmd_ide.c Image header has correct checksum
3332 -51 common/cmd_ide.c Error reading Image from IDE device
3333 51 common/cmd_ide.c reading Image from IDE device OK
3334 52 common/cmd_nand.c before loading a Image from a NAND device
3335 -53 common/cmd_nand.c Bad usage of "nand" command
3336 53 common/cmd_nand.c correct usage of "nand" command
3337 -54 common/cmd_nand.c No boot device
3338 54 common/cmd_nand.c boot device found
3339 -55 common/cmd_nand.c Unknown Chip ID on boot device
3340 55 common/cmd_nand.c correct chip ID found, device available
3341 -56 common/cmd_nand.c Error reading Image Header on boot device
3342 56 common/cmd_nand.c reading Image Header from NAND device OK
3343 -57 common/cmd_nand.c Image header has bad magic number
3344 57 common/cmd_nand.c Image header has correct magic number
3345 -58 common/cmd_nand.c Error reading Image from NAND device
3346 58 common/cmd_nand.c reading Image from NAND device OK
3348 -60 common/env_common.c Environment has a bad CRC, using default
3350 64 net/eth.c starting with Ethernet configuration.
3351 -64 net/eth.c no Ethernet found.
3352 65 net/eth.c Ethernet found.
3354 -80 common/cmd_net.c usage wrong
3355 80 common/cmd_net.c before calling NetLoop()
3356 -81 common/cmd_net.c some error in NetLoop() occurred
3357 81 common/cmd_net.c NetLoop() back without error
3358 -82 common/cmd_net.c size == 0 (File with size 0 loaded)
3359 82 common/cmd_net.c trying automatic boot
3360 83 common/cmd_net.c running "source" command
3361 -83 common/cmd_net.c some error in automatic boot or "source" command
3362 84 common/cmd_net.c end without errors
3367 100 common/cmd_bootm.c Kernel FIT Image has correct format
3368 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format
3369 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration
3370 -101 common/cmd_bootm.c Can't get configuration for kernel subimage
3371 102 common/cmd_bootm.c Kernel unit name specified
3372 -103 common/cmd_bootm.c Can't get kernel subimage node offset
3373 103 common/cmd_bootm.c Found configuration node
3374 104 common/cmd_bootm.c Got kernel subimage node offset
3375 -104 common/cmd_bootm.c Kernel subimage hash verification failed
3376 105 common/cmd_bootm.c Kernel subimage hash verification OK
3377 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture
3378 106 common/cmd_bootm.c Architecture check OK
3379 -106 common/cmd_bootm.c Kernel subimage has wrong type
3380 107 common/cmd_bootm.c Kernel subimage type OK
3381 -107 common/cmd_bootm.c Can't get kernel subimage data/size
3382 108 common/cmd_bootm.c Got kernel subimage data/size
3383 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT)
3384 -109 common/cmd_bootm.c Can't get kernel subimage type
3385 -110 common/cmd_bootm.c Can't get kernel subimage comp
3386 -111 common/cmd_bootm.c Can't get kernel subimage os
3387 -112 common/cmd_bootm.c Can't get kernel subimage load address
3388 -113 common/cmd_bootm.c Image uncompress/copy overwrite error
3390 120 common/image.c Start initial ramdisk verification
3391 -120 common/image.c Ramdisk FIT image has incorrect format
3392 121 common/image.c Ramdisk FIT image has correct format
3393 122 common/image.c No ramdisk subimage unit name, using configuration
3394 -122 common/image.c Can't get configuration for ramdisk subimage
3395 123 common/image.c Ramdisk unit name specified
3396 -124 common/image.c Can't get ramdisk subimage node offset
3397 125 common/image.c Got ramdisk subimage node offset
3398 -125 common/image.c Ramdisk subimage hash verification failed
3399 126 common/image.c Ramdisk subimage hash verification OK
3400 -126 common/image.c Ramdisk subimage for unsupported architecture
3401 127 common/image.c Architecture check OK
3402 -127 common/image.c Can't get ramdisk subimage data/size
3403 128 common/image.c Got ramdisk subimage data/size
3404 129 common/image.c Can't get ramdisk load address
3405 -129 common/image.c Got ramdisk load address
3407 -130 common/cmd_doc.c Incorrect FIT image format
3408 131 common/cmd_doc.c FIT image format OK
3410 -140 common/cmd_ide.c Incorrect FIT image format
3411 141 common/cmd_ide.c FIT image format OK
3413 -150 common/cmd_nand.c Incorrect FIT image format
3414 151 common/cmd_nand.c FIT image format OK
3416 - legacy image format:
3417 CONFIG_IMAGE_FORMAT_LEGACY
3418 enables the legacy image format support in U-Boot.
3421 enabled if CONFIG_FIT_SIGNATURE is not defined.
3423 CONFIG_DISABLE_IMAGE_LEGACY
3424 disable the legacy image format
3426 This define is introduced, as the legacy image format is
3427 enabled per default for backward compatibility.
3429 - FIT image support:
3431 Enable support for the FIT uImage format.
3433 CONFIG_FIT_BEST_MATCH
3434 When no configuration is explicitly selected, default to the
3435 one whose fdt's compatibility field best matches that of
3436 U-Boot itself. A match is considered "best" if it matches the
3437 most specific compatibility entry of U-Boot's fdt's root node.
3438 The order of entries in the configuration's fdt is ignored.
3440 CONFIG_FIT_SIGNATURE
3441 This option enables signature verification of FIT uImages,
3442 using a hash signed and verified using RSA. If
3443 CONFIG_SHA_PROG_HW_ACCEL is defined, i.e support for progressive
3444 hashing is available using hardware, RSA library will use it.
3445 See doc/uImage.FIT/signature.txt for more details.
3447 WARNING: When relying on signed FIT images with required
3448 signature check the legacy image format is default
3449 disabled. If a board need legacy image format support
3450 enable this through CONFIG_IMAGE_FORMAT_LEGACY
3452 CONFIG_FIT_DISABLE_SHA256
3453 Supporting SHA256 hashes has quite an impact on binary size.
3454 For constrained systems sha256 hash support can be disabled
3457 - Standalone program support:
3458 CONFIG_STANDALONE_LOAD_ADDR
3460 This option defines a board specific value for the
3461 address where standalone program gets loaded, thus
3462 overwriting the architecture dependent default
3465 - Frame Buffer Address:
3468 Define CONFIG_FB_ADDR if you want to use specific
3469 address for frame buffer. This is typically the case
3470 when using a graphics controller has separate video
3471 memory. U-Boot will then place the frame buffer at
3472 the given address instead of dynamically reserving it
3473 in system RAM by calling lcd_setmem(), which grabs
3474 the memory for the frame buffer depending on the
3475 configured panel size.
3477 Please see board_init_f function.
3479 - Automatic software updates via TFTP server
3481 CONFIG_UPDATE_TFTP_CNT_MAX
3482 CONFIG_UPDATE_TFTP_MSEC_MAX
3484 These options enable and control the auto-update feature;
3485 for a more detailed description refer to doc/README.update.
3487 - MTD Support (mtdparts command, UBI support)
3490 Adds the MTD device infrastructure from the Linux kernel.
3491 Needed for mtdparts command support.
3493 CONFIG_MTD_PARTITIONS
3495 Adds the MTD partitioning infrastructure from the Linux
3496 kernel. Needed for UBI support.
3498 CONFIG_MTD_NAND_VERIFY_WRITE
3499 verify if the written data is correct reread.
3504 Adds commands for interacting with MTD partitions formatted
3505 with the UBI flash translation layer
3507 Requires also defining CONFIG_RBTREE
3509 CONFIG_UBI_SILENCE_MSG
3511 Make the verbose messages from UBI stop printing. This leaves
3512 warnings and errors enabled.
3515 CONFIG_MTD_UBI_WL_THRESHOLD
3516 This parameter defines the maximum difference between the highest
3517 erase counter value and the lowest erase counter value of eraseblocks
3518 of UBI devices. When this threshold is exceeded, UBI starts performing
3519 wear leveling by means of moving data from eraseblock with low erase
3520 counter to eraseblocks with high erase counter.
3522 The default value should be OK for SLC NAND flashes, NOR flashes and
3523 other flashes which have eraseblock life-cycle 100000 or more.
3524 However, in case of MLC NAND flashes which typically have eraseblock
3525 life-cycle less than 10000, the threshold should be lessened (e.g.,
3526 to 128 or 256, although it does not have to be power of 2).
3530 CONFIG_MTD_UBI_BEB_LIMIT
3531 This option specifies the maximum bad physical eraseblocks UBI
3532 expects on the MTD device (per 1024 eraseblocks). If the
3533 underlying flash does not admit of bad eraseblocks (e.g. NOR
3534 flash), this value is ignored.
3536 NAND datasheets often specify the minimum and maximum NVM
3537 (Number of Valid Blocks) for the flashes' endurance lifetime.
3538 The maximum expected bad eraseblocks per 1024 eraseblocks
3539 then can be calculated as "1024 * (1 - MinNVB / MaxNVB)",
3540 which gives 20 for most NANDs (MaxNVB is basically the total
3541 count of eraseblocks on the chip).
3543 To put it differently, if this value is 20, UBI will try to
3544 reserve about 1.9% of physical eraseblocks for bad blocks
3545 handling. And that will be 1.9% of eraseblocks on the entire
3546 NAND chip, not just the MTD partition UBI attaches. This means
3547 that if you have, say, a NAND flash chip admits maximum 40 bad
3548 eraseblocks, and it is split on two MTD partitions of the same
3549 size, UBI will reserve 40 eraseblocks when attaching a
3554 CONFIG_MTD_UBI_FASTMAP
3555 Fastmap is a mechanism which allows attaching an UBI device
3556 in nearly constant time. Instead of scanning the whole MTD device it
3557 only has to locate a checkpoint (called fastmap) on the device.
3558 The on-flash fastmap contains all information needed to attach
3559 the device. Using fastmap makes only sense on large devices where
3560 attaching by scanning takes long. UBI will not automatically install
3561 a fastmap on old images, but you can set the UBI parameter
3562 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT to 1 if you want so. Please note
3563 that fastmap-enabled images are still usable with UBI implementations
3564 without fastmap support. On typical flash devices the whole fastmap
3565 fits into one PEB. UBI will reserve PEBs to hold two fastmaps.
3567 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT
3568 Set this parameter to enable fastmap automatically on images
3575 Adds commands for interacting with UBI volumes formatted as
3576 UBIFS. UBIFS is read-only in u-boot.
3578 Requires UBI support as well as CONFIG_LZO
3580 CONFIG_UBIFS_SILENCE_MSG
3582 Make the verbose messages from UBIFS stop printing. This leaves
3583 warnings and errors enabled.
3587 Enable building of SPL globally.
3590 LDSCRIPT for linking the SPL binary.
3592 CONFIG_SPL_MAX_FOOTPRINT
3593 Maximum size in memory allocated to the SPL, BSS included.
3594 When defined, the linker checks that the actual memory
3595 used by SPL from _start to __bss_end does not exceed it.
3596 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
3597 must not be both defined at the same time.
3600 Maximum size of the SPL image (text, data, rodata, and
3601 linker lists sections), BSS excluded.
3602 When defined, the linker checks that the actual size does
3605 CONFIG_SPL_TEXT_BASE
3606 TEXT_BASE for linking the SPL binary.
3608 CONFIG_SPL_RELOC_TEXT_BASE
3609 Address to relocate to. If unspecified, this is equal to
3610 CONFIG_SPL_TEXT_BASE (i.e. no relocation is done).
3612 CONFIG_SPL_BSS_START_ADDR
3613 Link address for the BSS within the SPL binary.
3615 CONFIG_SPL_BSS_MAX_SIZE
3616 Maximum size in memory allocated to the SPL BSS.
3617 When defined, the linker checks that the actual memory used
3618 by SPL from __bss_start to __bss_end does not exceed it.
3619 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
3620 must not be both defined at the same time.
3623 Adress of the start of the stack SPL will use
3625 CONFIG_SPL_RELOC_STACK
3626 Adress of the start of the stack SPL will use after
3627 relocation. If unspecified, this is equal to
3630 CONFIG_SYS_SPL_MALLOC_START
3631 Starting address of the malloc pool used in SPL.
3633 CONFIG_SYS_SPL_MALLOC_SIZE
3634 The size of the malloc pool used in SPL.
3636 CONFIG_SPL_FRAMEWORK
3637 Enable the SPL framework under common/. This framework
3638 supports MMC, NAND and YMODEM loading of U-Boot and NAND
3639 NAND loading of the Linux Kernel.
3642 Enable booting directly to an OS from SPL.
3643 See also: doc/README.falcon
3645 CONFIG_SPL_DISPLAY_PRINT
3646 For ARM, enable an optional function to print more information
3647 about the running system.
3649 CONFIG_SPL_INIT_MINIMAL
3650 Arch init code should be built for a very small image
3652 CONFIG_SPL_LIBCOMMON_SUPPORT
3653 Support for common/libcommon.o in SPL binary
3655 CONFIG_SPL_LIBDISK_SUPPORT
3656 Support for disk/libdisk.o in SPL binary
3658 CONFIG_SPL_I2C_SUPPORT
3659 Support for drivers/i2c/libi2c.o in SPL binary
3661 CONFIG_SPL_GPIO_SUPPORT
3662 Support for drivers/gpio/libgpio.o in SPL binary
3664 CONFIG_SPL_MMC_SUPPORT
3665 Support for drivers/mmc/libmmc.o in SPL binary
3667 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_SECTOR,
3668 CONFIG_SYS_U_BOOT_MAX_SIZE_SECTORS,
3669 Address and partition on the MMC to load U-Boot from
3670 when the MMC is being used in raw mode.
3672 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_PARTITION
3673 Partition on the MMC to load U-Boot from when the MMC is being
3676 CONFIG_SYS_MMCSD_RAW_MODE_KERNEL_SECTOR
3677 Sector to load kernel uImage from when MMC is being
3678 used in raw mode (for Falcon mode)
3680 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTOR,
3681 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTORS
3682 Sector and number of sectors to load kernel argument
3683 parameters from when MMC is being used in raw mode
3686 CONFIG_SYS_MMCSD_FS_BOOT_PARTITION
3687 Partition on the MMC to load U-Boot from when the MMC is being
3690 CONFIG_SPL_FAT_SUPPORT
3691 Support for fs/fat/libfat.o in SPL binary
3693 CONFIG_SPL_EXT_SUPPORT
3694 Support for EXT filesystem in SPL binary
3696 CONFIG_SPL_FS_LOAD_PAYLOAD_NAME
3697 Filename to read to load U-Boot when reading from filesystem
3699 CONFIG_SPL_FS_LOAD_KERNEL_NAME
3700 Filename to read to load kernel uImage when reading
3701 from filesystem (for Falcon mode)
3703 CONFIG_SPL_FS_LOAD_ARGS_NAME
3704 Filename to read to load kernel argument parameters
3705 when reading from filesystem (for Falcon mode)
3707 CONFIG_SPL_MPC83XX_WAIT_FOR_NAND
3708 Set this for NAND SPL on PPC mpc83xx targets, so that
3709 start.S waits for the rest of the SPL to load before
3710 continuing (the hardware starts execution after just
3711 loading the first page rather than the full 4K).
3713 CONFIG_SPL_SKIP_RELOCATE
3714 Avoid SPL relocation
3716 CONFIG_SPL_NAND_BASE
3717 Include nand_base.c in the SPL. Requires
3718 CONFIG_SPL_NAND_DRIVERS.
3720 CONFIG_SPL_NAND_DRIVERS
3721 SPL uses normal NAND drivers, not minimal drivers.
3724 Include standard software ECC in the SPL
3726 CONFIG_SPL_NAND_SIMPLE
3727 Support for NAND boot using simple NAND drivers that
3728 expose the cmd_ctrl() interface.
3730 CONFIG_SPL_MTD_SUPPORT
3731 Support for the MTD subsystem within SPL. Useful for
3732 environment on NAND support within SPL.
3734 CONFIG_SPL_NAND_RAW_ONLY
3735 Support to boot only raw u-boot.bin images. Use this only
3736 if you need to save space.
3738 CONFIG_SPL_MPC8XXX_INIT_DDR_SUPPORT
3739 Set for the SPL on PPC mpc8xxx targets, support for
3740 drivers/ddr/fsl/libddr.o in SPL binary.
3742 CONFIG_SPL_COMMON_INIT_DDR
3743 Set for common ddr init with serial presence detect in
3746 CONFIG_SYS_NAND_5_ADDR_CYCLE, CONFIG_SYS_NAND_PAGE_COUNT,
3747 CONFIG_SYS_NAND_PAGE_SIZE, CONFIG_SYS_NAND_OOBSIZE,
3748 CONFIG_SYS_NAND_BLOCK_SIZE, CONFIG_SYS_NAND_BAD_BLOCK_POS,
3749 CONFIG_SYS_NAND_ECCPOS, CONFIG_SYS_NAND_ECCSIZE,
3750 CONFIG_SYS_NAND_ECCBYTES
3751 Defines the size and behavior of the NAND that SPL uses
3754 CONFIG_SPL_NAND_BOOT
3755 Add support NAND boot
3757 CONFIG_SYS_NAND_U_BOOT_OFFS
3758 Location in NAND to read U-Boot from
3760 CONFIG_SYS_NAND_U_BOOT_DST
3761 Location in memory to load U-Boot to
3763 CONFIG_SYS_NAND_U_BOOT_SIZE
3764 Size of image to load
3766 CONFIG_SYS_NAND_U_BOOT_START
3767 Entry point in loaded image to jump to
3769 CONFIG_SYS_NAND_HW_ECC_OOBFIRST
3770 Define this if you need to first read the OOB and then the
3771 data. This is used, for example, on davinci platforms.
3773 CONFIG_SPL_OMAP3_ID_NAND
3774 Support for an OMAP3-specific set of functions to return the
3775 ID and MFR of the first attached NAND chip, if present.
3777 CONFIG_SPL_SERIAL_SUPPORT
3778 Support for drivers/serial/libserial.o in SPL binary
3780 CONFIG_SPL_SPI_FLASH_SUPPORT
3781 Support for drivers/mtd/spi/libspi_flash.o in SPL binary
3783 CONFIG_SPL_SPI_SUPPORT
3784 Support for drivers/spi/libspi.o in SPL binary
3786 CONFIG_SPL_RAM_DEVICE
3787 Support for running image already present in ram, in SPL binary
3789 CONFIG_SPL_LIBGENERIC_SUPPORT
3790 Support for lib/libgeneric.o in SPL binary
3792 CONFIG_SPL_ENV_SUPPORT
3793 Support for the environment operating in SPL binary
3795 CONFIG_SPL_NET_SUPPORT
3796 Support for the net/libnet.o in SPL binary.
3797 It conflicts with SPL env from storage medium specified by
3798 CONFIG_ENV_IS_xxx but CONFIG_ENV_IS_NOWHERE
3801 Image offset to which the SPL should be padded before appending
3802 the SPL payload. By default, this is defined as
3803 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3804 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3805 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3808 Final target image containing SPL and payload. Some SPLs
3809 use an arch-specific makefile fragment instead, for
3810 example if more than one image needs to be produced.
3812 CONFIG_FIT_SPL_PRINT
3813 Printing information about a FIT image adds quite a bit of
3814 code to SPL. So this is normally disabled in SPL. Use this
3815 option to re-enable it. This will affect the output of the
3816 bootm command when booting a FIT image.
3820 Enable building of TPL globally.
3823 Image offset to which the TPL should be padded before appending
3824 the TPL payload. By default, this is defined as
3825 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3826 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3827 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3832 [so far only for SMDK2400 boards]
3834 - Modem support enable:
3835 CONFIG_MODEM_SUPPORT
3837 - RTS/CTS Flow control enable:
3840 - Modem debug support:
3841 CONFIG_MODEM_SUPPORT_DEBUG
3843 Enables debugging stuff (char screen[1024], dbg())
3844 for modem support. Useful only with BDI2000.
3846 - Interrupt support (PPC):
3848 There are common interrupt_init() and timer_interrupt()
3849 for all PPC archs. interrupt_init() calls interrupt_init_cpu()
3850 for CPU specific initialization. interrupt_init_cpu()
3851 should set decrementer_count to appropriate value. If
3852 CPU resets decrementer automatically after interrupt
3853 (ppc4xx) it should set decrementer_count to zero.
3854 timer_interrupt() calls timer_interrupt_cpu() for CPU
3855 specific handling. If board has watchdog / status_led
3856 / other_activity_monitor it works automatically from
3857 general timer_interrupt().
3861 In the target system modem support is enabled when a
3862 specific key (key combination) is pressed during
3863 power-on. Otherwise U-Boot will boot normally
3864 (autoboot). The key_pressed() function is called from
3865 board_init(). Currently key_pressed() is a dummy
3866 function, returning 1 and thus enabling modem
3869 If there are no modem init strings in the
3870 environment, U-Boot proceed to autoboot; the
3871 previous output (banner, info printfs) will be
3874 See also: doc/README.Modem
3876 Board initialization settings:
3877 ------------------------------
3879 During Initialization u-boot calls a number of board specific functions
3880 to allow the preparation of board specific prerequisites, e.g. pin setup
3881 before drivers are initialized. To enable these callbacks the
3882 following configuration macros have to be defined. Currently this is
3883 architecture specific, so please check arch/your_architecture/lib/board.c
3884 typically in board_init_f() and board_init_r().
3886 - CONFIG_BOARD_EARLY_INIT_F: Call board_early_init_f()
3887 - CONFIG_BOARD_EARLY_INIT_R: Call board_early_init_r()
3888 - CONFIG_BOARD_LATE_INIT: Call board_late_init()
3889 - CONFIG_BOARD_POSTCLK_INIT: Call board_postclk_init()
3891 Configuration Settings:
3892 -----------------------
3894 - CONFIG_SYS_SUPPORT_64BIT_DATA: Defined automatically if compiled as 64-bit.
3895 Optionally it can be defined to support 64-bit memory commands.
3897 - CONFIG_SYS_LONGHELP: Defined when you want long help messages included;
3898 undefine this when you're short of memory.
3900 - CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default
3901 width of the commands listed in the 'help' command output.
3903 - CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to
3904 prompt for user input.
3906 - CONFIG_SYS_CBSIZE: Buffer size for input from the Console
3908 - CONFIG_SYS_PBSIZE: Buffer size for Console output
3910 - CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands
3912 - CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to
3913 the application (usually a Linux kernel) when it is
3916 - CONFIG_SYS_BAUDRATE_TABLE:
3917 List of legal baudrate settings for this board.
3919 - CONFIG_SYS_CONSOLE_INFO_QUIET
3920 Suppress display of console information at boot.
3922 - CONFIG_SYS_CONSOLE_IS_IN_ENV
3923 If the board specific function
3924 extern int overwrite_console (void);
3925 returns 1, the stdin, stderr and stdout are switched to the
3926 serial port, else the settings in the environment are used.
3928 - CONFIG_SYS_CONSOLE_OVERWRITE_ROUTINE
3929 Enable the call to overwrite_console().
3931 - CONFIG_SYS_CONSOLE_ENV_OVERWRITE
3932 Enable overwrite of previous console environment settings.
3934 - CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END:
3935 Begin and End addresses of the area used by the
3938 - CONFIG_SYS_ALT_MEMTEST:
3939 Enable an alternate, more extensive memory test.
3941 - CONFIG_SYS_MEMTEST_SCRATCH:
3942 Scratch address used by the alternate memory test
3943 You only need to set this if address zero isn't writeable
3945 - CONFIG_SYS_MEM_TOP_HIDE (PPC only):
3946 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header,
3947 this specified memory area will get subtracted from the top
3948 (end) of RAM and won't get "touched" at all by U-Boot. By
3949 fixing up gd->ram_size the Linux kernel should gets passed
3950 the now "corrected" memory size and won't touch it either.
3951 This should work for arch/ppc and arch/powerpc. Only Linux
3952 board ports in arch/powerpc with bootwrapper support that
3953 recalculate the memory size from the SDRAM controller setup
3954 will have to get fixed in Linux additionally.
3956 This option can be used as a workaround for the 440EPx/GRx
3957 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't
3960 WARNING: Please make sure that this value is a multiple of
3961 the Linux page size (normally 4k). If this is not the case,
3962 then the end address of the Linux memory will be located at a
3963 non page size aligned address and this could cause major
3966 - CONFIG_SYS_LOADS_BAUD_CHANGE:
3967 Enable temporary baudrate change while serial download
3969 - CONFIG_SYS_SDRAM_BASE:
3970 Physical start address of SDRAM. _Must_ be 0 here.
3972 - CONFIG_SYS_MBIO_BASE:
3973 Physical start address of Motherboard I/O (if using a
3976 - CONFIG_SYS_FLASH_BASE:
3977 Physical start address of Flash memory.
3979 - CONFIG_SYS_MONITOR_BASE:
3980 Physical start address of boot monitor code (set by
3981 make config files to be same as the text base address
3982 (CONFIG_SYS_TEXT_BASE) used when linking) - same as
3983 CONFIG_SYS_FLASH_BASE when booting from flash.
3985 - CONFIG_SYS_MONITOR_LEN:
3986 Size of memory reserved for monitor code, used to
3987 determine _at_compile_time_ (!) if the environment is
3988 embedded within the U-Boot image, or in a separate
3991 - CONFIG_SYS_MALLOC_LEN:
3992 Size of DRAM reserved for malloc() use.
3994 - CONFIG_SYS_MALLOC_F_LEN
3995 Size of the malloc() pool for use before relocation. If
3996 this is defined, then a very simple malloc() implementation
3997 will become available before relocation. The address is just
3998 below the global data, and the stack is moved down to make
4001 This feature allocates regions with increasing addresses
4002 within the region. calloc() is supported, but realloc()
4003 is not available. free() is supported but does nothing.
4004 The memory will be freed (or in fact just forgotten) when
4005 U-Boot relocates itself.
4007 Pre-relocation malloc() is only supported on ARM and sandbox
4008 at present but is fairly easy to enable for other archs.
4010 - CONFIG_SYS_MALLOC_SIMPLE
4011 Provides a simple and small malloc() and calloc() for those
4012 boards which do not use the full malloc in SPL (which is
4013 enabled with CONFIG_SYS_SPL_MALLOC_START).
4015 - CONFIG_SYS_NONCACHED_MEMORY:
4016 Size of non-cached memory area. This area of memory will be
4017 typically located right below the malloc() area and mapped
4018 uncached in the MMU. This is useful for drivers that would
4019 otherwise require a lot of explicit cache maintenance. For
4020 some drivers it's also impossible to properly maintain the
4021 cache. For example if the regions that need to be flushed
4022 are not a multiple of the cache-line size, *and* padding
4023 cannot be allocated between the regions to align them (i.e.
4024 if the HW requires a contiguous array of regions, and the
4025 size of each region is not cache-aligned), then a flush of
4026 one region may result in overwriting data that hardware has
4027 written to another region in the same cache-line. This can
4028 happen for example in network drivers where descriptors for
4029 buffers are typically smaller than the CPU cache-line (e.g.
4030 16 bytes vs. 32 or 64 bytes).
4032 Non-cached memory is only supported on 32-bit ARM at present.
4034 - CONFIG_SYS_BOOTM_LEN:
4035 Normally compressed uImages are limited to an
4036 uncompressed size of 8 MBytes. If this is not enough,
4037 you can define CONFIG_SYS_BOOTM_LEN in your board config file
4038 to adjust this setting to your needs.
4040 - CONFIG_SYS_BOOTMAPSZ:
4041 Maximum size of memory mapped by the startup code of
4042 the Linux kernel; all data that must be processed by
4043 the Linux kernel (bd_info, boot arguments, FDT blob if
4044 used) must be put below this limit, unless "bootm_low"
4045 environment variable is defined and non-zero. In such case
4046 all data for the Linux kernel must be between "bootm_low"
4047 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ. The environment
4048 variable "bootm_mapsize" will override the value of
4049 CONFIG_SYS_BOOTMAPSZ. If CONFIG_SYS_BOOTMAPSZ is undefined,
4050 then the value in "bootm_size" will be used instead.
4052 - CONFIG_SYS_BOOT_RAMDISK_HIGH:
4053 Enable initrd_high functionality. If defined then the
4054 initrd_high feature is enabled and the bootm ramdisk subcommand
4057 - CONFIG_SYS_BOOT_GET_CMDLINE:
4058 Enables allocating and saving kernel cmdline in space between
4059 "bootm_low" and "bootm_low" + BOOTMAPSZ.
4061 - CONFIG_SYS_BOOT_GET_KBD:
4062 Enables allocating and saving a kernel copy of the bd_info in
4063 space between "bootm_low" and "bootm_low" + BOOTMAPSZ.
4065 - CONFIG_SYS_MAX_FLASH_BANKS:
4066 Max number of Flash memory banks
4068 - CONFIG_SYS_MAX_FLASH_SECT:
4069 Max number of sectors on a Flash chip
4071 - CONFIG_SYS_FLASH_ERASE_TOUT:
4072 Timeout for Flash erase operations (in ms)
4074 - CONFIG_SYS_FLASH_WRITE_TOUT:
4075 Timeout for Flash write operations (in ms)
4077 - CONFIG_SYS_FLASH_LOCK_TOUT
4078 Timeout for Flash set sector lock bit operation (in ms)
4080 - CONFIG_SYS_FLASH_UNLOCK_TOUT
4081 Timeout for Flash clear lock bits operation (in ms)
4083 - CONFIG_SYS_FLASH_PROTECTION
4084 If defined, hardware flash sectors protection is used
4085 instead of U-Boot software protection.
4087 - CONFIG_SYS_DIRECT_FLASH_TFTP:
4089 Enable TFTP transfers directly to flash memory;
4090 without this option such a download has to be
4091 performed in two steps: (1) download to RAM, and (2)
4092 copy from RAM to flash.
4094 The two-step approach is usually more reliable, since
4095 you can check if the download worked before you erase
4096 the flash, but in some situations (when system RAM is
4097 too limited to allow for a temporary copy of the
4098 downloaded image) this option may be very useful.
4100 - CONFIG_SYS_FLASH_CFI:
4101 Define if the flash driver uses extra elements in the
4102 common flash structure for storing flash geometry.
4104 - CONFIG_FLASH_CFI_DRIVER
4105 This option also enables the building of the cfi_flash driver
4106 in the drivers directory
4108 - CONFIG_FLASH_CFI_MTD
4109 This option enables the building of the cfi_mtd driver
4110 in the drivers directory. The driver exports CFI flash
4113 - CONFIG_SYS_FLASH_USE_BUFFER_WRITE
4114 Use buffered writes to flash.
4116 - CONFIG_FLASH_SPANSION_S29WS_N
4117 s29ws-n MirrorBit flash has non-standard addresses for buffered
4120 - CONFIG_SYS_FLASH_QUIET_TEST
4121 If this option is defined, the common CFI flash doesn't
4122 print it's warning upon not recognized FLASH banks. This
4123 is useful, if some of the configured banks are only
4124 optionally available.
4126 - CONFIG_FLASH_SHOW_PROGRESS
4127 If defined (must be an integer), print out countdown
4128 digits and dots. Recommended value: 45 (9..1) for 80
4129 column displays, 15 (3..1) for 40 column displays.
4131 - CONFIG_FLASH_VERIFY
4132 If defined, the content of the flash (destination) is compared
4133 against the source after the write operation. An error message
4134 will be printed when the contents are not identical.
4135 Please note that this option is useless in nearly all cases,
4136 since such flash programming errors usually are detected earlier
4137 while unprotecting/erasing/programming. Please only enable
4138 this option if you really know what you are doing.
4140 - CONFIG_SYS_RX_ETH_BUFFER:
4141 Defines the number of Ethernet receive buffers. On some
4142 Ethernet controllers it is recommended to set this value
4143 to 8 or even higher (EEPRO100 or 405 EMAC), since all
4144 buffers can be full shortly after enabling the interface
4145 on high Ethernet traffic.
4146 Defaults to 4 if not defined.
4148 - CONFIG_ENV_MAX_ENTRIES
4150 Maximum number of entries in the hash table that is used
4151 internally to store the environment settings. The default
4152 setting is supposed to be generous and should work in most
4153 cases. This setting can be used to tune behaviour; see
4154 lib/hashtable.c for details.
4156 - CONFIG_ENV_FLAGS_LIST_DEFAULT
4157 - CONFIG_ENV_FLAGS_LIST_STATIC
4158 Enable validation of the values given to environment variables when
4159 calling env set. Variables can be restricted to only decimal,
4160 hexadecimal, or boolean. If CONFIG_CMD_NET is also defined,
4161 the variables can also be restricted to IP address or MAC address.
4163 The format of the list is:
4164 type_attribute = [s|d|x|b|i|m]
4165 access_attribute = [a|r|o|c]
4166 attributes = type_attribute[access_attribute]
4167 entry = variable_name[:attributes]
4170 The type attributes are:
4171 s - String (default)
4174 b - Boolean ([1yYtT|0nNfF])
4178 The access attributes are:
4184 - CONFIG_ENV_FLAGS_LIST_DEFAULT
4185 Define this to a list (string) to define the ".flags"
4186 environment variable in the default or embedded environment.
4188 - CONFIG_ENV_FLAGS_LIST_STATIC
4189 Define this to a list (string) to define validation that
4190 should be done if an entry is not found in the ".flags"
4191 environment variable. To override a setting in the static
4192 list, simply add an entry for the same variable name to the
4195 - CONFIG_ENV_ACCESS_IGNORE_FORCE
4196 If defined, don't allow the -f switch to env set override variable
4199 - CONFIG_SYS_GENERIC_BOARD
4200 This selects the architecture-generic board system instead of the
4201 architecture-specific board files. It is intended to move boards
4202 to this new framework over time. Defining this will disable the
4203 arch/foo/lib/board.c file and use common/board_f.c and
4204 common/board_r.c instead. To use this option your architecture
4205 must support it (i.e. must define __HAVE_ARCH_GENERIC_BOARD in
4206 its config.mk file). If you find problems enabling this option on
4207 your board please report the problem and send patches!
4209 - CONFIG_OMAP_PLATFORM_RESET_TIME_MAX_USEC (OMAP only)
4210 This is set by OMAP boards for the max time that reset should
4211 be asserted. See doc/README.omap-reset-time for details on how
4212 the value can be calculated on a given board.
4215 If stdint.h is available with your toolchain you can define this
4216 option to enable it. You can provide option 'USE_STDINT=1' when
4217 building U-Boot to enable this.
4219 The following definitions that deal with the placement and management
4220 of environment data (variable area); in general, we support the
4221 following configurations:
4223 - CONFIG_BUILD_ENVCRC:
4225 Builds up envcrc with the target environment so that external utils
4226 may easily extract it and embed it in final U-Boot images.
4228 - CONFIG_ENV_IS_IN_FLASH:
4230 Define this if the environment is in flash memory.
4232 a) The environment occupies one whole flash sector, which is
4233 "embedded" in the text segment with the U-Boot code. This
4234 happens usually with "bottom boot sector" or "top boot
4235 sector" type flash chips, which have several smaller
4236 sectors at the start or the end. For instance, such a
4237 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In
4238 such a case you would place the environment in one of the
4239 4 kB sectors - with U-Boot code before and after it. With
4240 "top boot sector" type flash chips, you would put the
4241 environment in one of the last sectors, leaving a gap
4242 between U-Boot and the environment.
4244 - CONFIG_ENV_OFFSET:
4246 Offset of environment data (variable area) to the
4247 beginning of flash memory; for instance, with bottom boot
4248 type flash chips the second sector can be used: the offset
4249 for this sector is given here.
4251 CONFIG_ENV_OFFSET is used relative to CONFIG_SYS_FLASH_BASE.
4255 This is just another way to specify the start address of
4256 the flash sector containing the environment (instead of
4259 - CONFIG_ENV_SECT_SIZE:
4261 Size of the sector containing the environment.
4264 b) Sometimes flash chips have few, equal sized, BIG sectors.
4265 In such a case you don't want to spend a whole sector for
4270 If you use this in combination with CONFIG_ENV_IS_IN_FLASH
4271 and CONFIG_ENV_SECT_SIZE, you can specify to use only a part
4272 of this flash sector for the environment. This saves
4273 memory for the RAM copy of the environment.
4275 It may also save flash memory if you decide to use this
4276 when your environment is "embedded" within U-Boot code,
4277 since then the remainder of the flash sector could be used
4278 for U-Boot code. It should be pointed out that this is
4279 STRONGLY DISCOURAGED from a robustness point of view:
4280 updating the environment in flash makes it always
4281 necessary to erase the WHOLE sector. If something goes
4282 wrong before the contents has been restored from a copy in
4283 RAM, your target system will be dead.
4285 - CONFIG_ENV_ADDR_REDUND
4286 CONFIG_ENV_SIZE_REDUND
4288 These settings describe a second storage area used to hold
4289 a redundant copy of the environment data, so that there is
4290 a valid backup copy in case there is a power failure during
4291 a "saveenv" operation.
4293 BE CAREFUL! Any changes to the flash layout, and some changes to the
4294 source code will make it necessary to adapt <board>/u-boot.lds*
4298 - CONFIG_ENV_IS_IN_NVRAM:
4300 Define this if you have some non-volatile memory device
4301 (NVRAM, battery buffered SRAM) which you want to use for the
4307 These two #defines are used to determine the memory area you
4308 want to use for environment. It is assumed that this memory
4309 can just be read and written to, without any special
4312 BE CAREFUL! The first access to the environment happens quite early
4313 in U-Boot initialization (when we try to get the setting of for the
4314 console baudrate). You *MUST* have mapped your NVRAM area then, or
4317 Please note that even with NVRAM we still use a copy of the
4318 environment in RAM: we could work on NVRAM directly, but we want to
4319 keep settings there always unmodified except somebody uses "saveenv"
4320 to save the current settings.
4323 - CONFIG_ENV_IS_IN_EEPROM:
4325 Use this if you have an EEPROM or similar serial access
4326 device and a driver for it.
4328 - CONFIG_ENV_OFFSET:
4331 These two #defines specify the offset and size of the
4332 environment area within the total memory of your EEPROM.
4334 - CONFIG_SYS_I2C_EEPROM_ADDR:
4335 If defined, specified the chip address of the EEPROM device.
4336 The default address is zero.
4338 - CONFIG_SYS_I2C_EEPROM_BUS:
4339 If defined, specified the i2c bus of the EEPROM device.
4341 - CONFIG_SYS_EEPROM_PAGE_WRITE_BITS:
4342 If defined, the number of bits used to address bytes in a
4343 single page in the EEPROM device. A 64 byte page, for example
4344 would require six bits.
4346 - CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS:
4347 If defined, the number of milliseconds to delay between
4348 page writes. The default is zero milliseconds.
4350 - CONFIG_SYS_I2C_EEPROM_ADDR_LEN:
4351 The length in bytes of the EEPROM memory array address. Note
4352 that this is NOT the chip address length!
4354 - CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW:
4355 EEPROM chips that implement "address overflow" are ones
4356 like Catalyst 24WC04/08/16 which has 9/10/11 bits of
4357 address and the extra bits end up in the "chip address" bit
4358 slots. This makes a 24WC08 (1Kbyte) chip look like four 256
4361 Note that we consider the length of the address field to
4362 still be one byte because the extra address bits are hidden
4363 in the chip address.
4365 - CONFIG_SYS_EEPROM_SIZE:
4366 The size in bytes of the EEPROM device.
4368 - CONFIG_ENV_EEPROM_IS_ON_I2C
4369 define this, if you have I2C and SPI activated, and your
4370 EEPROM, which holds the environment, is on the I2C bus.
4372 - CONFIG_I2C_ENV_EEPROM_BUS
4373 if you have an Environment on an EEPROM reached over
4374 I2C muxes, you can define here, how to reach this
4375 EEPROM. For example:
4377 #define CONFIG_I2C_ENV_EEPROM_BUS 1
4379 EEPROM which holds the environment, is reached over
4380 a pca9547 i2c mux with address 0x70, channel 3.
4382 - CONFIG_ENV_IS_IN_DATAFLASH:
4384 Define this if you have a DataFlash memory device which you
4385 want to use for the environment.
4387 - CONFIG_ENV_OFFSET:
4391 These three #defines specify the offset and size of the
4392 environment area within the total memory of your DataFlash placed
4393 at the specified address.
4395 - CONFIG_ENV_IS_IN_SPI_FLASH:
4397 Define this if you have a SPI Flash memory device which you
4398 want to use for the environment.
4400 - CONFIG_ENV_OFFSET:
4403 These two #defines specify the offset and size of the
4404 environment area within the SPI Flash. CONFIG_ENV_OFFSET must be
4405 aligned to an erase sector boundary.
4407 - CONFIG_ENV_SECT_SIZE:
4409 Define the SPI flash's sector size.
4411 - CONFIG_ENV_OFFSET_REDUND (optional):
4413 This setting describes a second storage area of CONFIG_ENV_SIZE
4414 size used to hold a redundant copy of the environment data, so
4415 that there is a valid backup copy in case there is a power failure
4416 during a "saveenv" operation. CONFIG_ENV_OFFSET_RENDUND must be
4417 aligned to an erase sector boundary.
4419 - CONFIG_ENV_SPI_BUS (optional):
4420 - CONFIG_ENV_SPI_CS (optional):
4422 Define the SPI bus and chip select. If not defined they will be 0.
4424 - CONFIG_ENV_SPI_MAX_HZ (optional):
4426 Define the SPI max work clock. If not defined then use 1MHz.
4428 - CONFIG_ENV_SPI_MODE (optional):
4430 Define the SPI work mode. If not defined then use SPI_MODE_3.
4432 - CONFIG_ENV_IS_IN_REMOTE:
4434 Define this if you have a remote memory space which you
4435 want to use for the local device's environment.
4440 These two #defines specify the address and size of the
4441 environment area within the remote memory space. The
4442 local device can get the environment from remote memory
4443 space by SRIO or PCIE links.
4445 BE CAREFUL! For some special cases, the local device can not use
4446 "saveenv" command. For example, the local device will get the
4447 environment stored in a remote NOR flash by SRIO or PCIE link,
4448 but it can not erase, write this NOR flash by SRIO or PCIE interface.
4450 - CONFIG_ENV_IS_IN_NAND:
4452 Define this if you have a NAND device which you want to use
4453 for the environment.
4455 - CONFIG_ENV_OFFSET:
4458 These two #defines specify the offset and size of the environment
4459 area within the first NAND device. CONFIG_ENV_OFFSET must be
4460 aligned to an erase block boundary.
4462 - CONFIG_ENV_OFFSET_REDUND (optional):
4464 This setting describes a second storage area of CONFIG_ENV_SIZE
4465 size used to hold a redundant copy of the environment data, so
4466 that there is a valid backup copy in case there is a power failure
4467 during a "saveenv" operation. CONFIG_ENV_OFFSET_RENDUND must be
4468 aligned to an erase block boundary.
4470 - CONFIG_ENV_RANGE (optional):
4472 Specifies the length of the region in which the environment
4473 can be written. This should be a multiple of the NAND device's
4474 block size. Specifying a range with more erase blocks than
4475 are needed to hold CONFIG_ENV_SIZE allows bad blocks within
4476 the range to be avoided.
4478 - CONFIG_ENV_OFFSET_OOB (optional):
4480 Enables support for dynamically retrieving the offset of the
4481 environment from block zero's out-of-band data. The
4482 "nand env.oob" command can be used to record this offset.
4483 Currently, CONFIG_ENV_OFFSET_REDUND is not supported when
4484 using CONFIG_ENV_OFFSET_OOB.
4486 - CONFIG_NAND_ENV_DST
4488 Defines address in RAM to which the nand_spl code should copy the
4489 environment. If redundant environment is used, it will be copied to
4490 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE.
4492 - CONFIG_ENV_IS_IN_UBI:
4494 Define this if you have an UBI volume that you want to use for the
4495 environment. This has the benefit of wear-leveling the environment
4496 accesses, which is important on NAND.
4498 - CONFIG_ENV_UBI_PART:
4500 Define this to a string that is the mtd partition containing the UBI.
4502 - CONFIG_ENV_UBI_VOLUME:
4504 Define this to the name of the volume that you want to store the
4507 - CONFIG_ENV_UBI_VOLUME_REDUND:
4509 Define this to the name of another volume to store a second copy of
4510 the environment in. This will enable redundant environments in UBI.
4511 It is assumed that both volumes are in the same MTD partition.
4513 - CONFIG_UBI_SILENCE_MSG
4514 - CONFIG_UBIFS_SILENCE_MSG
4516 You will probably want to define these to avoid a really noisy system
4517 when storing the env in UBI.
4519 - CONFIG_ENV_IS_IN_FAT:
4520 Define this if you want to use the FAT file system for the environment.
4522 - FAT_ENV_INTERFACE:
4524 Define this to a string that is the name of the block device.
4526 - FAT_ENV_DEV_AND_PART:
4528 Define this to a string to specify the partition of the device. It can
4531 "D:P", "D:0", "D", "D:" or "D:auto" (D, P are integers. And P >= 1)
4532 - "D:P": device D partition P. Error occurs if device D has no
4535 - "D" or "D:": device D partition 1 if device D has partition
4536 table, or the whole device D if has no partition
4538 - "D:auto": first partition in device D with bootable flag set.
4539 If none, first valid partition in device D. If no
4540 partition table then means device D.
4544 It's a string of the FAT file name. This file use to store the
4548 This should be defined. Otherwise it cannot save the environment file.
4550 - CONFIG_ENV_IS_IN_MMC:
4552 Define this if you have an MMC device which you want to use for the
4555 - CONFIG_SYS_MMC_ENV_DEV:
4557 Specifies which MMC device the environment is stored in.
4559 - CONFIG_SYS_MMC_ENV_PART (optional):
4561 Specifies which MMC partition the environment is stored in. If not
4562 set, defaults to partition 0, the user area. Common values might be
4563 1 (first MMC boot partition), 2 (second MMC boot partition).
4565 - CONFIG_ENV_OFFSET:
4568 These two #defines specify the offset and size of the environment
4569 area within the specified MMC device.
4571 If offset is positive (the usual case), it is treated as relative to
4572 the start of the MMC partition. If offset is negative, it is treated
4573 as relative to the end of the MMC partition. This can be useful if
4574 your board may be fitted with different MMC devices, which have
4575 different sizes for the MMC partitions, and you always want the
4576 environment placed at the very end of the partition, to leave the
4577 maximum possible space before it, to store other data.
4579 These two values are in units of bytes, but must be aligned to an
4580 MMC sector boundary.
4582 - CONFIG_ENV_OFFSET_REDUND (optional):
4584 Specifies a second storage area, of CONFIG_ENV_SIZE size, used to
4585 hold a redundant copy of the environment data. This provides a
4586 valid backup copy in case the other copy is corrupted, e.g. due
4587 to a power failure during a "saveenv" operation.
4589 This value may also be positive or negative; this is handled in the
4590 same way as CONFIG_ENV_OFFSET.
4592 This value is also in units of bytes, but must also be aligned to
4593 an MMC sector boundary.
4595 - CONFIG_ENV_SIZE_REDUND (optional):
4597 This value need not be set, even when CONFIG_ENV_OFFSET_REDUND is
4598 set. If this value is set, it must be set to the same value as
4601 - CONFIG_SYS_SPI_INIT_OFFSET
4603 Defines offset to the initial SPI buffer area in DPRAM. The
4604 area is used at an early stage (ROM part) if the environment
4605 is configured to reside in the SPI EEPROM: We need a 520 byte
4606 scratch DPRAM area. It is used between the two initialization
4607 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems
4608 to be a good choice since it makes it far enough from the
4609 start of the data area as well as from the stack pointer.
4611 Please note that the environment is read-only until the monitor
4612 has been relocated to RAM and a RAM copy of the environment has been
4613 created; also, when using EEPROM you will have to use getenv_f()
4614 until then to read environment variables.
4616 The environment is protected by a CRC32 checksum. Before the monitor
4617 is relocated into RAM, as a result of a bad CRC you will be working
4618 with the compiled-in default environment - *silently*!!! [This is
4619 necessary, because the first environment variable we need is the
4620 "baudrate" setting for the console - if we have a bad CRC, we don't
4621 have any device yet where we could complain.]
4623 Note: once the monitor has been relocated, then it will complain if
4624 the default environment is used; a new CRC is computed as soon as you
4625 use the "saveenv" command to store a valid environment.
4627 - CONFIG_SYS_FAULT_ECHO_LINK_DOWN:
4628 Echo the inverted Ethernet link state to the fault LED.
4630 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR
4631 also needs to be defined.
4633 - CONFIG_SYS_FAULT_MII_ADDR:
4634 MII address of the PHY to check for the Ethernet link state.
4636 - CONFIG_NS16550_MIN_FUNCTIONS:
4637 Define this if you desire to only have use of the NS16550_init
4638 and NS16550_putc functions for the serial driver located at
4639 drivers/serial/ns16550.c. This option is useful for saving
4640 space for already greatly restricted images, including but not
4641 limited to NAND_SPL configurations.
4643 - CONFIG_DISPLAY_BOARDINFO
4644 Display information about the board that U-Boot is running on
4645 when U-Boot starts up. The board function checkboard() is called
4648 - CONFIG_DISPLAY_BOARDINFO_LATE
4649 Similar to the previous option, but display this information
4650 later, once stdio is running and output goes to the LCD, if
4653 - CONFIG_BOARD_SIZE_LIMIT:
4654 Maximum size of the U-Boot image. When defined, the
4655 build system checks that the actual size does not
4658 Low Level (hardware related) configuration options:
4659 ---------------------------------------------------
4661 - CONFIG_SYS_CACHELINE_SIZE:
4662 Cache Line Size of the CPU.
4664 - CONFIG_SYS_DEFAULT_IMMR:
4665 Default address of the IMMR after system reset.
4667 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU,
4668 and RPXsuper) to be able to adjust the position of
4669 the IMMR register after a reset.
4671 - CONFIG_SYS_CCSRBAR_DEFAULT:
4672 Default (power-on reset) physical address of CCSR on Freescale
4675 - CONFIG_SYS_CCSRBAR:
4676 Virtual address of CCSR. On a 32-bit build, this is typically
4677 the same value as CONFIG_SYS_CCSRBAR_DEFAULT.
4679 CONFIG_SYS_DEFAULT_IMMR must also be set to this value,
4680 for cross-platform code that uses that macro instead.
4682 - CONFIG_SYS_CCSRBAR_PHYS:
4683 Physical address of CCSR. CCSR can be relocated to a new
4684 physical address, if desired. In this case, this macro should
4685 be set to that address. Otherwise, it should be set to the
4686 same value as CONFIG_SYS_CCSRBAR_DEFAULT. For example, CCSR
4687 is typically relocated on 36-bit builds. It is recommended
4688 that this macro be defined via the _HIGH and _LOW macros:
4690 #define CONFIG_SYS_CCSRBAR_PHYS ((CONFIG_SYS_CCSRBAR_PHYS_HIGH
4691 * 1ull) << 32 | CONFIG_SYS_CCSRBAR_PHYS_LOW)
4693 - CONFIG_SYS_CCSRBAR_PHYS_HIGH:
4694 Bits 33-36 of CONFIG_SYS_CCSRBAR_PHYS. This value is typically
4695 either 0 (32-bit build) or 0xF (36-bit build). This macro is
4696 used in assembly code, so it must not contain typecasts or
4697 integer size suffixes (e.g. "ULL").
4699 - CONFIG_SYS_CCSRBAR_PHYS_LOW:
4700 Lower 32-bits of CONFIG_SYS_CCSRBAR_PHYS. This macro is
4701 used in assembly code, so it must not contain typecasts or
4702 integer size suffixes (e.g. "ULL").
4704 - CONFIG_SYS_CCSR_DO_NOT_RELOCATE:
4705 If this macro is defined, then CONFIG_SYS_CCSRBAR_PHYS will be
4706 forced to a value that ensures that CCSR is not relocated.
4708 - Floppy Disk Support:
4709 CONFIG_SYS_FDC_DRIVE_NUMBER
4711 the default drive number (default value 0)
4713 CONFIG_SYS_ISA_IO_STRIDE
4715 defines the spacing between FDC chipset registers
4718 CONFIG_SYS_ISA_IO_OFFSET
4720 defines the offset of register from address. It
4721 depends on which part of the data bus is connected to
4722 the FDC chipset. (default value 0)
4724 If CONFIG_SYS_ISA_IO_STRIDE CONFIG_SYS_ISA_IO_OFFSET and
4725 CONFIG_SYS_FDC_DRIVE_NUMBER are undefined, they take their
4728 if CONFIG_SYS_FDC_HW_INIT is defined, then the function
4729 fdc_hw_init() is called at the beginning of the FDC
4730 setup. fdc_hw_init() must be provided by the board
4731 source code. It is used to make hardware-dependent
4735 Most IDE controllers were designed to be connected with PCI
4736 interface. Only few of them were designed for AHB interface.
4737 When software is doing ATA command and data transfer to
4738 IDE devices through IDE-AHB controller, some additional
4739 registers accessing to these kind of IDE-AHB controller
4742 - CONFIG_SYS_IMMR: Physical address of the Internal Memory.
4743 DO NOT CHANGE unless you know exactly what you're
4744 doing! (11-4) [MPC8xx/82xx systems only]
4746 - CONFIG_SYS_INIT_RAM_ADDR:
4748 Start address of memory area that can be used for
4749 initial data and stack; please note that this must be
4750 writable memory that is working WITHOUT special
4751 initialization, i. e. you CANNOT use normal RAM which
4752 will become available only after programming the
4753 memory controller and running certain initialization
4756 U-Boot uses the following memory types:
4757 - MPC8xx and MPC8260: IMMR (internal memory of the CPU)
4758 - MPC824X: data cache
4759 - PPC4xx: data cache
4761 - CONFIG_SYS_GBL_DATA_OFFSET:
4763 Offset of the initial data structure in the memory
4764 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually
4765 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial
4766 data is located at the end of the available space
4767 (sometimes written as (CONFIG_SYS_INIT_RAM_SIZE -
4768 CONFIG_SYS_INIT_DATA_SIZE), and the initial stack is just
4769 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR +
4770 CONFIG_SYS_GBL_DATA_OFFSET) downward.
4773 On the MPC824X (or other systems that use the data
4774 cache for initial memory) the address chosen for
4775 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must
4776 point to an otherwise UNUSED address space between
4777 the top of RAM and the start of the PCI space.
4779 - CONFIG_SYS_SIUMCR: SIU Module Configuration (11-6)
4781 - CONFIG_SYS_SYPCR: System Protection Control (11-9)
4783 - CONFIG_SYS_TBSCR: Time Base Status and Control (11-26)
4785 - CONFIG_SYS_PISCR: Periodic Interrupt Status and Control (11-31)
4787 - CONFIG_SYS_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30)
4789 - CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27)
4791 - CONFIG_SYS_OR_TIMING_SDRAM:
4794 - CONFIG_SYS_MAMR_PTA:
4795 periodic timer for refresh
4797 - CONFIG_SYS_DER: Debug Event Register (37-47)
4799 - FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM,
4800 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP,
4801 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM,
4802 CONFIG_SYS_BR1_PRELIM:
4803 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
4805 - SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
4806 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM,
4807 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM:
4808 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
4810 - CONFIG_SYS_MAMR_PTA, CONFIG_SYS_MPTPR_2BK_4K, CONFIG_SYS_MPTPR_1BK_4K, CONFIG_SYS_MPTPR_2BK_8K,
4811 CONFIG_SYS_MPTPR_1BK_8K, CONFIG_SYS_MAMR_8COL, CONFIG_SYS_MAMR_9COL:
4812 Machine Mode Register and Memory Periodic Timer
4813 Prescaler definitions (SDRAM timing)
4815 - CONFIG_SYS_I2C_UCODE_PATCH, CONFIG_SYS_I2C_DPMEM_OFFSET [0x1FC0]:
4816 enable I2C microcode relocation patch (MPC8xx);
4817 define relocation offset in DPRAM [DSP2]
4819 - CONFIG_SYS_SMC_UCODE_PATCH, CONFIG_SYS_SMC_DPMEM_OFFSET [0x1FC0]:
4820 enable SMC microcode relocation patch (MPC8xx);
4821 define relocation offset in DPRAM [SMC1]
4823 - CONFIG_SYS_SPI_UCODE_PATCH, CONFIG_SYS_SPI_DPMEM_OFFSET [0x1FC0]:
4824 enable SPI microcode relocation patch (MPC8xx);
4825 define relocation offset in DPRAM [SCC4]
4827 - CONFIG_SYS_USE_OSCCLK:
4828 Use OSCM clock mode on MBX8xx board. Be careful,
4829 wrong setting might damage your board. Read
4830 doc/README.MBX before setting this variable!
4832 - CONFIG_SYS_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only)
4833 Offset of the bootmode word in DPRAM used by post
4834 (Power On Self Tests). This definition overrides
4835 #define'd default value in commproc.h resp.
4838 - CONFIG_SYS_PCI_SLV_MEM_LOCAL, CONFIG_SYS_PCI_SLV_MEM_BUS, CONFIG_SYS_PICMR0_MASK_ATTRIB,
4839 CONFIG_SYS_PCI_MSTR0_LOCAL, CONFIG_SYS_PCIMSK0_MASK, CONFIG_SYS_PCI_MSTR1_LOCAL,
4840 CONFIG_SYS_PCIMSK1_MASK, CONFIG_SYS_PCI_MSTR_MEM_LOCAL, CONFIG_SYS_PCI_MSTR_MEM_BUS,
4841 CONFIG_SYS_CPU_PCI_MEM_START, CONFIG_SYS_PCI_MSTR_MEM_SIZE, CONFIG_SYS_POCMR0_MASK_ATTRIB,
4842 CONFIG_SYS_PCI_MSTR_MEMIO_LOCAL, CONFIG_SYS_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START,
4843 CONFIG_SYS_PCI_MSTR_MEMIO_SIZE, CONFIG_SYS_POCMR1_MASK_ATTRIB, CONFIG_SYS_PCI_MSTR_IO_LOCAL,
4844 CONFIG_SYS_PCI_MSTR_IO_BUS, CONFIG_SYS_CPU_PCI_IO_START, CONFIG_SYS_PCI_MSTR_IO_SIZE,
4845 CONFIG_SYS_POCMR2_MASK_ATTRIB: (MPC826x only)
4846 Overrides the default PCI memory map in arch/powerpc/cpu/mpc8260/pci.c if set.
4848 - CONFIG_PCI_DISABLE_PCIE:
4849 Disable PCI-Express on systems where it is supported but not
4852 - CONFIG_PCI_ENUM_ONLY
4853 Only scan through and get the devices on the buses.
4854 Don't do any setup work, presumably because someone or
4855 something has already done it, and we don't need to do it
4856 a second time. Useful for platforms that are pre-booted
4857 by coreboot or similar.
4859 - CONFIG_PCI_INDIRECT_BRIDGE:
4860 Enable support for indirect PCI bridges.
4863 Chip has SRIO or not
4866 Board has SRIO 1 port available
4869 Board has SRIO 2 port available
4871 - CONFIG_SRIO_PCIE_BOOT_MASTER
4872 Board can support master function for Boot from SRIO and PCIE
4874 - CONFIG_SYS_SRIOn_MEM_VIRT:
4875 Virtual Address of SRIO port 'n' memory region
4877 - CONFIG_SYS_SRIOn_MEM_PHYS:
4878 Physical Address of SRIO port 'n' memory region
4880 - CONFIG_SYS_SRIOn_MEM_SIZE:
4881 Size of SRIO port 'n' memory region
4883 - CONFIG_SYS_NAND_BUSWIDTH_16BIT
4884 Defined to tell the NAND controller that the NAND chip is using
4886 Not all NAND drivers use this symbol.
4887 Example of drivers that use it:
4888 - drivers/mtd/nand/ndfc.c
4889 - drivers/mtd/nand/mxc_nand.c
4891 - CONFIG_SYS_NDFC_EBC0_CFG
4892 Sets the EBC0_CFG register for the NDFC. If not defined
4893 a default value will be used.
4896 Get DDR timing information from an I2C EEPROM. Common
4897 with pluggable memory modules such as SODIMMs
4900 I2C address of the SPD EEPROM
4902 - CONFIG_SYS_SPD_BUS_NUM
4903 If SPD EEPROM is on an I2C bus other than the first
4904 one, specify here. Note that the value must resolve
4905 to something your driver can deal with.
4907 - CONFIG_SYS_DDR_RAW_TIMING
4908 Get DDR timing information from other than SPD. Common with
4909 soldered DDR chips onboard without SPD. DDR raw timing
4910 parameters are extracted from datasheet and hard-coded into
4911 header files or board specific files.
4913 - CONFIG_FSL_DDR_INTERACTIVE
4914 Enable interactive DDR debugging. See doc/README.fsl-ddr.
4916 - CONFIG_FSL_DDR_SYNC_REFRESH
4917 Enable sync of refresh for multiple controllers.
4919 - CONFIG_SYS_83XX_DDR_USES_CS0
4920 Only for 83xx systems. If specified, then DDR should
4921 be configured using CS0 and CS1 instead of CS2 and CS3.
4923 - CONFIG_ETHER_ON_FEC[12]
4924 Define to enable FEC[12] on a 8xx series processor.
4926 - CONFIG_FEC[12]_PHY
4927 Define to the hardcoded PHY address which corresponds
4928 to the given FEC; i. e.
4929 #define CONFIG_FEC1_PHY 4
4930 means that the PHY with address 4 is connected to FEC1
4932 When set to -1, means to probe for first available.
4934 - CONFIG_FEC[12]_PHY_NORXERR
4935 The PHY does not have a RXERR line (RMII only).
4936 (so program the FEC to ignore it).
4939 Enable RMII mode for all FECs.
4940 Note that this is a global option, we can't
4941 have one FEC in standard MII mode and another in RMII mode.
4943 - CONFIG_CRC32_VERIFY
4944 Add a verify option to the crc32 command.
4947 => crc32 -v <address> <count> <crc32>
4949 Where address/count indicate a memory area
4950 and crc32 is the correct crc32 which the
4954 Add the "loopw" memory command. This only takes effect if
4955 the memory commands are activated globally (CONFIG_CMD_MEM).
4958 Add the "mdc" and "mwc" memory commands. These are cyclic
4963 This command will print 4 bytes (10,11,12,13) each 500 ms.
4965 => mwc.l 100 12345678 10
4966 This command will write 12345678 to address 100 all 10 ms.
4968 This only takes effect if the memory commands are activated
4969 globally (CONFIG_CMD_MEM).
4971 - CONFIG_SKIP_LOWLEVEL_INIT
4972 [ARM, NDS32, MIPS only] If this variable is defined, then certain
4973 low level initializations (like setting up the memory
4974 controller) are omitted and/or U-Boot does not
4975 relocate itself into RAM.
4977 Normally this variable MUST NOT be defined. The only
4978 exception is when U-Boot is loaded (to RAM) by some
4979 other boot loader or by a debugger which performs
4980 these initializations itself.
4983 Modifies the behaviour of start.S when compiling a loader
4984 that is executed before the actual U-Boot. E.g. when
4985 compiling a NAND SPL.
4988 Modifies the behaviour of start.S when compiling a loader
4989 that is executed after the SPL and before the actual U-Boot.
4990 It is loaded by the SPL.
4992 - CONFIG_SYS_MPC85XX_NO_RESETVEC
4993 Only for 85xx systems. If this variable is specified, the section
4994 .resetvec is not kept and the section .bootpg is placed in the
4995 previous 4k of the .text section.
4997 - CONFIG_ARCH_MAP_SYSMEM
4998 Generally U-Boot (and in particular the md command) uses
4999 effective address. It is therefore not necessary to regard
5000 U-Boot address as virtual addresses that need to be translated
5001 to physical addresses. However, sandbox requires this, since
5002 it maintains its own little RAM buffer which contains all
5003 addressable memory. This option causes some memory accesses
5004 to be mapped through map_sysmem() / unmap_sysmem().
5006 - CONFIG_USE_ARCH_MEMCPY
5007 CONFIG_USE_ARCH_MEMSET
5008 If these options are used a optimized version of memcpy/memset will
5009 be used if available. These functions may be faster under some
5010 conditions but may increase the binary size.
5012 - CONFIG_X86_RESET_VECTOR
5013 If defined, the x86 reset vector code is included. This is not
5014 needed when U-Boot is running from Coreboot.
5017 Defines the MPU clock speed (in MHz).
5019 NOTE : currently only supported on AM335x platforms.
5021 - CONFIG_SPL_AM33XX_ENABLE_RTC32K_OSC:
5022 Enables the RTC32K OSC on AM33xx based plattforms
5024 - CONFIG_SYS_NAND_NO_SUBPAGE_WRITE
5025 Option to disable subpage write in NAND driver
5026 driver that uses this:
5027 drivers/mtd/nand/davinci_nand.c
5029 Freescale QE/FMAN Firmware Support:
5030 -----------------------------------
5032 The Freescale QUICCEngine (QE) and Frame Manager (FMAN) both support the
5033 loading of "firmware", which is encoded in the QE firmware binary format.
5034 This firmware often needs to be loaded during U-Boot booting, so macros
5035 are used to identify the storage device (NOR flash, SPI, etc) and the address
5038 - CONFIG_SYS_FMAN_FW_ADDR
5039 The address in the storage device where the FMAN microcode is located. The
5040 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
5043 - CONFIG_SYS_QE_FW_ADDR
5044 The address in the storage device where the QE microcode is located. The
5045 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
5048 - CONFIG_SYS_QE_FMAN_FW_LENGTH
5049 The maximum possible size of the firmware. The firmware binary format
5050 has a field that specifies the actual size of the firmware, but it
5051 might not be possible to read any part of the firmware unless some
5052 local storage is allocated to hold the entire firmware first.
5054 - CONFIG_SYS_QE_FMAN_FW_IN_NOR
5055 Specifies that QE/FMAN firmware is located in NOR flash, mapped as
5056 normal addressable memory via the LBC. CONFIG_SYS_FMAN_FW_ADDR is the
5057 virtual address in NOR flash.
5059 - CONFIG_SYS_QE_FMAN_FW_IN_NAND
5060 Specifies that QE/FMAN firmware is located in NAND flash.
5061 CONFIG_SYS_FMAN_FW_ADDR is the offset within NAND flash.
5063 - CONFIG_SYS_QE_FMAN_FW_IN_MMC
5064 Specifies that QE/FMAN firmware is located on the primary SD/MMC
5065 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
5067 - CONFIG_SYS_QE_FMAN_FW_IN_SPIFLASH
5068 Specifies that QE/FMAN firmware is located on the primary SPI
5069 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
5071 - CONFIG_SYS_QE_FMAN_FW_IN_REMOTE
5072 Specifies that QE/FMAN firmware is located in the remote (master)
5073 memory space. CONFIG_SYS_FMAN_FW_ADDR is a virtual address which
5074 can be mapped from slave TLB->slave LAW->slave SRIO or PCIE outbound
5075 window->master inbound window->master LAW->the ucode address in
5076 master's memory space.
5078 Freescale Layerscape Management Complex Firmware Support:
5079 ---------------------------------------------------------
5080 The Freescale Layerscape Management Complex (MC) supports the loading of
5082 This firmware often needs to be loaded during U-Boot booting, so macros
5083 are used to identify the storage device (NOR flash, SPI, etc) and the address
5086 - CONFIG_FSL_MC_ENET
5087 Enable the MC driver for Layerscape SoCs.
5089 - CONFIG_SYS_LS_MC_FW_ADDR
5090 The address in the storage device where the firmware is located. The
5091 meaning of this address depends on which CONFIG_SYS_LS_MC_FW_IN_xxx macro
5094 - CONFIG_SYS_LS_MC_FW_LENGTH
5095 The maximum possible size of the firmware. The firmware binary format
5096 has a field that specifies the actual size of the firmware, but it
5097 might not be possible to read any part of the firmware unless some
5098 local storage is allocated to hold the entire firmware first.
5100 - CONFIG_SYS_LS_MC_FW_IN_NOR
5101 Specifies that MC firmware is located in NOR flash, mapped as
5102 normal addressable memory via the LBC. CONFIG_SYS_LS_MC_FW_ADDR is the
5103 virtual address in NOR flash.
5105 Building the Software:
5106 ======================
5108 Building U-Boot has been tested in several native build environments
5109 and in many different cross environments. Of course we cannot support
5110 all possibly existing versions of cross development tools in all
5111 (potentially obsolete) versions. In case of tool chain problems we
5112 recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK)
5113 which is extensively used to build and test U-Boot.
5115 If you are not using a native environment, it is assumed that you
5116 have GNU cross compiling tools available in your path. In this case,
5117 you must set the environment variable CROSS_COMPILE in your shell.
5118 Note that no changes to the Makefile or any other source files are
5119 necessary. For example using the ELDK on a 4xx CPU, please enter:
5121 $ CROSS_COMPILE=ppc_4xx-
5122 $ export CROSS_COMPILE
5124 Note: If you wish to generate Windows versions of the utilities in
5125 the tools directory you can use the MinGW toolchain
5126 (http://www.mingw.org). Set your HOST tools to the MinGW
5127 toolchain and execute 'make tools'. For example:
5129 $ make HOSTCC=i586-mingw32msvc-gcc HOSTSTRIP=i586-mingw32msvc-strip tools
5131 Binaries such as tools/mkimage.exe will be created which can
5132 be executed on computers running Windows.
5134 U-Boot is intended to be simple to build. After installing the
5135 sources you must configure U-Boot for one specific board type. This
5140 where "NAME_defconfig" is the name of one of the existing configu-
5141 rations; see boards.cfg for supported names.
5143 Note: for some board special configuration names may exist; check if
5144 additional information is available from the board vendor; for
5145 instance, the TQM823L systems are available without (standard)
5146 or with LCD support. You can select such additional "features"
5147 when choosing the configuration, i. e.
5149 make TQM823L_defconfig
5150 - will configure for a plain TQM823L, i. e. no LCD support
5152 make TQM823L_LCD_defconfig
5153 - will configure for a TQM823L with U-Boot console on LCD
5158 Finally, type "make all", and you should get some working U-Boot
5159 images ready for download to / installation on your system:
5161 - "u-boot.bin" is a raw binary image
5162 - "u-boot" is an image in ELF binary format
5163 - "u-boot.srec" is in Motorola S-Record format
5165 By default the build is performed locally and the objects are saved
5166 in the source directory. One of the two methods can be used to change
5167 this behavior and build U-Boot to some external directory:
5169 1. Add O= to the make command line invocations:
5171 make O=/tmp/build distclean
5172 make O=/tmp/build NAME_defconfig
5173 make O=/tmp/build all
5175 2. Set environment variable KBUILD_OUTPUT to point to the desired location:
5177 export KBUILD_OUTPUT=/tmp/build
5182 Note that the command line "O=" setting overrides the KBUILD_OUTPUT environment
5186 Please be aware that the Makefiles assume you are using GNU make, so
5187 for instance on NetBSD you might need to use "gmake" instead of
5191 If the system board that you have is not listed, then you will need
5192 to port U-Boot to your hardware platform. To do this, follow these
5195 1. Add a new configuration option for your board to the toplevel
5196 "boards.cfg" file, using the existing entries as examples.
5197 Follow the instructions there to keep the boards in order.
5198 2. Create a new directory to hold your board specific code. Add any
5199 files you need. In your board directory, you will need at least
5200 the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds".
5201 3. Create a new configuration file "include/configs/<board>.h" for
5203 3. If you're porting U-Boot to a new CPU, then also create a new
5204 directory to hold your CPU specific code. Add any files you need.
5205 4. Run "make <board>_defconfig" with your new name.
5206 5. Type "make", and you should get a working "u-boot.srec" file
5207 to be installed on your target system.
5208 6. Debug and solve any problems that might arise.
5209 [Of course, this last step is much harder than it sounds.]
5212 Testing of U-Boot Modifications, Ports to New Hardware, etc.:
5213 ==============================================================
5215 If you have modified U-Boot sources (for instance added a new board
5216 or support for new devices, a new CPU, etc.) you are expected to
5217 provide feedback to the other developers. The feedback normally takes
5218 the form of a "patch", i. e. a context diff against a certain (latest
5219 official or latest in the git repository) version of U-Boot sources.
5221 But before you submit such a patch, please verify that your modifi-
5222 cation did not break existing code. At least make sure that *ALL* of
5223 the supported boards compile WITHOUT ANY compiler warnings. To do so,
5224 just run the "MAKEALL" script, which will configure and build U-Boot
5225 for ALL supported system. Be warned, this will take a while. You can
5226 select which (cross) compiler to use by passing a `CROSS_COMPILE'
5227 environment variable to the script, i. e. to use the ELDK cross tools
5230 CROSS_COMPILE=ppc_8xx- MAKEALL
5232 or to build on a native PowerPC system you can type
5234 CROSS_COMPILE=' ' MAKEALL
5236 When using the MAKEALL script, the default behaviour is to build
5237 U-Boot in the source directory. This location can be changed by
5238 setting the BUILD_DIR environment variable. Also, for each target
5239 built, the MAKEALL script saves two log files (<target>.ERR and
5240 <target>.MAKEALL) in the <source dir>/LOG directory. This default
5241 location can be changed by setting the MAKEALL_LOGDIR environment
5242 variable. For example:
5244 export BUILD_DIR=/tmp/build
5245 export MAKEALL_LOGDIR=/tmp/log
5246 CROSS_COMPILE=ppc_8xx- MAKEALL
5248 With the above settings build objects are saved in the /tmp/build,
5249 log files are saved in the /tmp/log and the source tree remains clean
5250 during the whole build process.
5253 See also "U-Boot Porting Guide" below.
5256 Monitor Commands - Overview:
5257 ============================
5259 go - start application at address 'addr'
5260 run - run commands in an environment variable
5261 bootm - boot application image from memory
5262 bootp - boot image via network using BootP/TFTP protocol
5263 bootz - boot zImage from memory
5264 tftpboot- boot image via network using TFTP protocol
5265 and env variables "ipaddr" and "serverip"
5266 (and eventually "gatewayip")
5267 tftpput - upload a file via network using TFTP protocol
5268 rarpboot- boot image via network using RARP/TFTP protocol
5269 diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
5270 loads - load S-Record file over serial line
5271 loadb - load binary file over serial line (kermit mode)
5273 mm - memory modify (auto-incrementing)
5274 nm - memory modify (constant address)
5275 mw - memory write (fill)
5277 cmp - memory compare
5278 crc32 - checksum calculation
5279 i2c - I2C sub-system
5280 sspi - SPI utility commands
5281 base - print or set address offset
5282 printenv- print environment variables
5283 setenv - set environment variables
5284 saveenv - save environment variables to persistent storage
5285 protect - enable or disable FLASH write protection
5286 erase - erase FLASH memory
5287 flinfo - print FLASH memory information
5288 nand - NAND memory operations (see doc/README.nand)
5289 bdinfo - print Board Info structure
5290 iminfo - print header information for application image
5291 coninfo - print console devices and informations
5292 ide - IDE sub-system
5293 loop - infinite loop on address range
5294 loopw - infinite write loop on address range
5295 mtest - simple RAM test
5296 icache - enable or disable instruction cache
5297 dcache - enable or disable data cache
5298 reset - Perform RESET of the CPU
5299 echo - echo args to console
5300 version - print monitor version
5301 help - print online help
5302 ? - alias for 'help'
5305 Monitor Commands - Detailed Description:
5306 ========================================
5310 For now: just type "help <command>".
5313 Environment Variables:
5314 ======================
5316 U-Boot supports user configuration using Environment Variables which
5317 can be made persistent by saving to Flash memory.
5319 Environment Variables are set using "setenv", printed using
5320 "printenv", and saved to Flash using "saveenv". Using "setenv"
5321 without a value can be used to delete a variable from the
5322 environment. As long as you don't save the environment you are
5323 working with an in-memory copy. In case the Flash area containing the
5324 environment is erased by accident, a default environment is provided.
5326 Some configuration options can be set using Environment Variables.
5328 List of environment variables (most likely not complete):
5330 baudrate - see CONFIG_BAUDRATE
5332 bootdelay - see CONFIG_BOOTDELAY
5334 bootcmd - see CONFIG_BOOTCOMMAND
5336 bootargs - Boot arguments when booting an RTOS image
5338 bootfile - Name of the image to load with TFTP
5340 bootm_low - Memory range available for image processing in the bootm
5341 command can be restricted. This variable is given as
5342 a hexadecimal number and defines lowest address allowed
5343 for use by the bootm command. See also "bootm_size"
5344 environment variable. Address defined by "bootm_low" is
5345 also the base of the initial memory mapping for the Linux
5346 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ and
5349 bootm_mapsize - Size of the initial memory mapping for the Linux kernel.
5350 This variable is given as a hexadecimal number and it
5351 defines the size of the memory region starting at base
5352 address bootm_low that is accessible by the Linux kernel
5353 during early boot. If unset, CONFIG_SYS_BOOTMAPSZ is used
5354 as the default value if it is defined, and bootm_size is
5357 bootm_size - Memory range available for image processing in the bootm
5358 command can be restricted. This variable is given as
5359 a hexadecimal number and defines the size of the region
5360 allowed for use by the bootm command. See also "bootm_low"
5361 environment variable.
5363 updatefile - Location of the software update file on a TFTP server, used
5364 by the automatic software update feature. Please refer to
5365 documentation in doc/README.update for more details.
5367 autoload - if set to "no" (any string beginning with 'n'),
5368 "bootp" will just load perform a lookup of the
5369 configuration from the BOOTP server, but not try to
5370 load any image using TFTP
5372 autostart - if set to "yes", an image loaded using the "bootp",
5373 "rarpboot", "tftpboot" or "diskboot" commands will
5374 be automatically started (by internally calling
5377 If set to "no", a standalone image passed to the
5378 "bootm" command will be copied to the load address
5379 (and eventually uncompressed), but NOT be started.
5380 This can be used to load and uncompress arbitrary
5383 fdt_high - if set this restricts the maximum address that the
5384 flattened device tree will be copied into upon boot.
5385 For example, if you have a system with 1 GB memory
5386 at physical address 0x10000000, while Linux kernel
5387 only recognizes the first 704 MB as low memory, you
5388 may need to set fdt_high as 0x3C000000 to have the
5389 device tree blob be copied to the maximum address
5390 of the 704 MB low memory, so that Linux kernel can
5391 access it during the boot procedure.
5393 If this is set to the special value 0xFFFFFFFF then
5394 the fdt will not be copied at all on boot. For this
5395 to work it must reside in writable memory, have
5396 sufficient padding on the end of it for u-boot to
5397 add the information it needs into it, and the memory
5398 must be accessible by the kernel.
5400 fdtcontroladdr- if set this is the address of the control flattened
5401 device tree used by U-Boot when CONFIG_OF_CONTROL is
5404 i2cfast - (PPC405GP|PPC405EP only)
5405 if set to 'y' configures Linux I2C driver for fast
5406 mode (400kHZ). This environment variable is used in
5407 initialization code. So, for changes to be effective
5408 it must be saved and board must be reset.
5410 initrd_high - restrict positioning of initrd images:
5411 If this variable is not set, initrd images will be
5412 copied to the highest possible address in RAM; this
5413 is usually what you want since it allows for
5414 maximum initrd size. If for some reason you want to
5415 make sure that the initrd image is loaded below the
5416 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment
5417 variable to a value of "no" or "off" or "0".
5418 Alternatively, you can set it to a maximum upper
5419 address to use (U-Boot will still check that it
5420 does not overwrite the U-Boot stack and data).
5422 For instance, when you have a system with 16 MB
5423 RAM, and want to reserve 4 MB from use by Linux,
5424 you can do this by adding "mem=12M" to the value of
5425 the "bootargs" variable. However, now you must make
5426 sure that the initrd image is placed in the first
5427 12 MB as well - this can be done with
5429 setenv initrd_high 00c00000
5431 If you set initrd_high to 0xFFFFFFFF, this is an
5432 indication to U-Boot that all addresses are legal
5433 for the Linux kernel, including addresses in flash
5434 memory. In this case U-Boot will NOT COPY the
5435 ramdisk at all. This may be useful to reduce the
5436 boot time on your system, but requires that this
5437 feature is supported by your Linux kernel.
5439 ipaddr - IP address; needed for tftpboot command
5441 loadaddr - Default load address for commands like "bootp",
5442 "rarpboot", "tftpboot", "loadb" or "diskboot"
5444 loads_echo - see CONFIG_LOADS_ECHO
5446 serverip - TFTP server IP address; needed for tftpboot command
5448 bootretry - see CONFIG_BOOT_RETRY_TIME
5450 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
5452 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
5454 ethprime - controls which interface is used first.
5456 ethact - controls which interface is currently active.
5457 For example you can do the following
5459 => setenv ethact FEC
5460 => ping 192.168.0.1 # traffic sent on FEC
5461 => setenv ethact SCC
5462 => ping 10.0.0.1 # traffic sent on SCC
5464 ethrotate - When set to "no" U-Boot does not go through all
5465 available network interfaces.
5466 It just stays at the currently selected interface.
5468 netretry - When set to "no" each network operation will
5469 either succeed or fail without retrying.
5470 When set to "once" the network operation will
5471 fail when all the available network interfaces
5472 are tried once without success.
5473 Useful on scripts which control the retry operation
5476 npe_ucode - set load address for the NPE microcode
5478 silent_linux - If set then Linux will be told to boot silently, by
5479 changing the console to be empty. If "yes" it will be
5480 made silent. If "no" it will not be made silent. If
5481 unset, then it will be made silent if the U-Boot console
5484 tftpsrcport - If this is set, the value is used for TFTP's
5487 tftpdstport - If this is set, the value is used for TFTP's UDP
5488 destination port instead of the Well Know Port 69.
5490 tftpblocksize - Block size to use for TFTP transfers; if not set,
5491 we use the TFTP server's default block size
5493 tftptimeout - Retransmission timeout for TFTP packets (in milli-
5494 seconds, minimum value is 1000 = 1 second). Defines
5495 when a packet is considered to be lost so it has to
5496 be retransmitted. The default is 5000 = 5 seconds.
5497 Lowering this value may make downloads succeed
5498 faster in networks with high packet loss rates or
5499 with unreliable TFTP servers.
5501 vlan - When set to a value < 4095 the traffic over
5502 Ethernet is encapsulated/received over 802.1q
5505 The following image location variables contain the location of images
5506 used in booting. The "Image" column gives the role of the image and is
5507 not an environment variable name. The other columns are environment
5508 variable names. "File Name" gives the name of the file on a TFTP
5509 server, "RAM Address" gives the location in RAM the image will be
5510 loaded to, and "Flash Location" gives the image's address in NOR
5511 flash or offset in NAND flash.
5513 *Note* - these variables don't have to be defined for all boards, some
5514 boards currenlty use other variables for these purposes, and some
5515 boards use these variables for other purposes.
5517 Image File Name RAM Address Flash Location
5518 ----- --------- ----------- --------------
5519 u-boot u-boot u-boot_addr_r u-boot_addr
5520 Linux kernel bootfile kernel_addr_r kernel_addr
5521 device tree blob fdtfile fdt_addr_r fdt_addr
5522 ramdisk ramdiskfile ramdisk_addr_r ramdisk_addr
5524 The following environment variables may be used and automatically
5525 updated by the network boot commands ("bootp" and "rarpboot"),
5526 depending the information provided by your boot server:
5528 bootfile - see above
5529 dnsip - IP address of your Domain Name Server
5530 dnsip2 - IP address of your secondary Domain Name Server
5531 gatewayip - IP address of the Gateway (Router) to use
5532 hostname - Target hostname
5534 netmask - Subnet Mask
5535 rootpath - Pathname of the root filesystem on the NFS server
5536 serverip - see above
5539 There are two special Environment Variables:
5541 serial# - contains hardware identification information such
5542 as type string and/or serial number
5543 ethaddr - Ethernet address
5545 These variables can be set only once (usually during manufacturing of
5546 the board). U-Boot refuses to delete or overwrite these variables
5547 once they have been set once.
5550 Further special Environment Variables:
5552 ver - Contains the U-Boot version string as printed
5553 with the "version" command. This variable is
5554 readonly (see CONFIG_VERSION_VARIABLE).
5557 Please note that changes to some configuration parameters may take
5558 only effect after the next boot (yes, that's just like Windoze :-).
5561 Callback functions for environment variables:
5562 ---------------------------------------------
5564 For some environment variables, the behavior of u-boot needs to change
5565 when their values are changed. This functionality allows functions to
5566 be associated with arbitrary variables. On creation, overwrite, or
5567 deletion, the callback will provide the opportunity for some side
5568 effect to happen or for the change to be rejected.
5570 The callbacks are named and associated with a function using the
5571 U_BOOT_ENV_CALLBACK macro in your board or driver code.
5573 These callbacks are associated with variables in one of two ways. The
5574 static list can be added to by defining CONFIG_ENV_CALLBACK_LIST_STATIC
5575 in the board configuration to a string that defines a list of
5576 associations. The list must be in the following format:
5578 entry = variable_name[:callback_name]
5581 If the callback name is not specified, then the callback is deleted.
5582 Spaces are also allowed anywhere in the list.
5584 Callbacks can also be associated by defining the ".callbacks" variable
5585 with the same list format above. Any association in ".callbacks" will
5586 override any association in the static list. You can define
5587 CONFIG_ENV_CALLBACK_LIST_DEFAULT to a list (string) to define the
5588 ".callbacks" environment variable in the default or embedded environment.
5591 Command Line Parsing:
5592 =====================
5594 There are two different command line parsers available with U-Boot:
5595 the old "simple" one, and the much more powerful "hush" shell:
5597 Old, simple command line parser:
5598 --------------------------------
5600 - supports environment variables (through setenv / saveenv commands)
5601 - several commands on one line, separated by ';'
5602 - variable substitution using "... ${name} ..." syntax
5603 - special characters ('$', ';') can be escaped by prefixing with '\',
5605 setenv bootcmd bootm \${address}
5606 - You can also escape text by enclosing in single apostrophes, for example:
5607 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
5612 - similar to Bourne shell, with control structures like
5613 if...then...else...fi, for...do...done; while...do...done,
5614 until...do...done, ...
5615 - supports environment ("global") variables (through setenv / saveenv
5616 commands) and local shell variables (through standard shell syntax
5617 "name=value"); only environment variables can be used with "run"
5623 (1) If a command line (or an environment variable executed by a "run"
5624 command) contains several commands separated by semicolon, and
5625 one of these commands fails, then the remaining commands will be
5628 (2) If you execute several variables with one call to run (i. e.
5629 calling run with a list of variables as arguments), any failing
5630 command will cause "run" to terminate, i. e. the remaining
5631 variables are not executed.
5633 Note for Redundant Ethernet Interfaces:
5634 =======================================
5636 Some boards come with redundant Ethernet interfaces; U-Boot supports
5637 such configurations and is capable of automatic selection of a
5638 "working" interface when needed. MAC assignment works as follows:
5640 Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
5641 MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
5642 "eth1addr" (=>eth1), "eth2addr", ...
5644 If the network interface stores some valid MAC address (for instance
5645 in SROM), this is used as default address if there is NO correspon-
5646 ding setting in the environment; if the corresponding environment
5647 variable is set, this overrides the settings in the card; that means:
5649 o If the SROM has a valid MAC address, and there is no address in the
5650 environment, the SROM's address is used.
5652 o If there is no valid address in the SROM, and a definition in the
5653 environment exists, then the value from the environment variable is
5656 o If both the SROM and the environment contain a MAC address, and
5657 both addresses are the same, this MAC address is used.
5659 o If both the SROM and the environment contain a MAC address, and the
5660 addresses differ, the value from the environment is used and a
5663 o If neither SROM nor the environment contain a MAC address, an error
5666 If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses
5667 will be programmed into hardware as part of the initialization process. This
5668 may be skipped by setting the appropriate 'ethmacskip' environment variable.
5669 The naming convention is as follows:
5670 "ethmacskip" (=>eth0), "eth1macskip" (=>eth1) etc.
5675 U-Boot is capable of booting (and performing other auxiliary operations on)
5676 images in two formats:
5678 New uImage format (FIT)
5679 -----------------------
5681 Flexible and powerful format based on Flattened Image Tree -- FIT (similar
5682 to Flattened Device Tree). It allows the use of images with multiple
5683 components (several kernels, ramdisks, etc.), with contents protected by
5684 SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory.
5690 Old image format is based on binary files which can be basically anything,
5691 preceded by a special header; see the definitions in include/image.h for
5692 details; basically, the header defines the following image properties:
5694 * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
5695 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
5696 LynxOS, pSOS, QNX, RTEMS, INTEGRITY;
5697 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS,
5699 * Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86,
5700 IA64, MIPS, NDS32, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
5701 Currently supported: ARM, AVR32, Intel x86, MIPS, NDS32, Nios II, PowerPC).
5702 * Compression Type (uncompressed, gzip, bzip2)
5708 The header is marked by a special Magic Number, and both the header
5709 and the data portions of the image are secured against corruption by
5716 Although U-Boot should support any OS or standalone application
5717 easily, the main focus has always been on Linux during the design of
5720 U-Boot includes many features that so far have been part of some
5721 special "boot loader" code within the Linux kernel. Also, any
5722 "initrd" images to be used are no longer part of one big Linux image;
5723 instead, kernel and "initrd" are separate images. This implementation
5724 serves several purposes:
5726 - the same features can be used for other OS or standalone
5727 applications (for instance: using compressed images to reduce the
5728 Flash memory footprint)
5730 - it becomes much easier to port new Linux kernel versions because
5731 lots of low-level, hardware dependent stuff are done by U-Boot
5733 - the same Linux kernel image can now be used with different "initrd"
5734 images; of course this also means that different kernel images can
5735 be run with the same "initrd". This makes testing easier (you don't
5736 have to build a new "zImage.initrd" Linux image when you just
5737 change a file in your "initrd"). Also, a field-upgrade of the
5738 software is easier now.
5744 Porting Linux to U-Boot based systems:
5745 ---------------------------------------
5747 U-Boot cannot save you from doing all the necessary modifications to
5748 configure the Linux device drivers for use with your target hardware
5749 (no, we don't intend to provide a full virtual machine interface to
5752 But now you can ignore ALL boot loader code (in arch/powerpc/mbxboot).
5754 Just make sure your machine specific header file (for instance
5755 include/asm-ppc/tqm8xx.h) includes the same definition of the Board
5756 Information structure as we define in include/asm-<arch>/u-boot.h,
5757 and make sure that your definition of IMAP_ADDR uses the same value
5758 as your U-Boot configuration in CONFIG_SYS_IMMR.
5760 Note that U-Boot now has a driver model, a unified model for drivers.
5761 If you are adding a new driver, plumb it into driver model. If there
5762 is no uclass available, you are encouraged to create one. See
5766 Configuring the Linux kernel:
5767 -----------------------------
5769 No specific requirements for U-Boot. Make sure you have some root
5770 device (initial ramdisk, NFS) for your target system.
5773 Building a Linux Image:
5774 -----------------------
5776 With U-Boot, "normal" build targets like "zImage" or "bzImage" are
5777 not used. If you use recent kernel source, a new build target
5778 "uImage" will exist which automatically builds an image usable by
5779 U-Boot. Most older kernels also have support for a "pImage" target,
5780 which was introduced for our predecessor project PPCBoot and uses a
5781 100% compatible format.
5785 make TQM850L_defconfig
5790 The "uImage" build target uses a special tool (in 'tools/mkimage') to
5791 encapsulate a compressed Linux kernel image with header information,
5792 CRC32 checksum etc. for use with U-Boot. This is what we are doing:
5794 * build a standard "vmlinux" kernel image (in ELF binary format):
5796 * convert the kernel into a raw binary image:
5798 ${CROSS_COMPILE}-objcopy -O binary \
5799 -R .note -R .comment \
5800 -S vmlinux linux.bin
5802 * compress the binary image:
5806 * package compressed binary image for U-Boot:
5808 mkimage -A ppc -O linux -T kernel -C gzip \
5809 -a 0 -e 0 -n "Linux Kernel Image" \
5810 -d linux.bin.gz uImage
5813 The "mkimage" tool can also be used to create ramdisk images for use
5814 with U-Boot, either separated from the Linux kernel image, or
5815 combined into one file. "mkimage" encapsulates the images with a 64
5816 byte header containing information about target architecture,
5817 operating system, image type, compression method, entry points, time
5818 stamp, CRC32 checksums, etc.
5820 "mkimage" can be called in two ways: to verify existing images and
5821 print the header information, or to build new images.
5823 In the first form (with "-l" option) mkimage lists the information
5824 contained in the header of an existing U-Boot image; this includes
5825 checksum verification:
5827 tools/mkimage -l image
5828 -l ==> list image header information
5830 The second form (with "-d" option) is used to build a U-Boot image
5831 from a "data file" which is used as image payload:
5833 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
5834 -n name -d data_file image
5835 -A ==> set architecture to 'arch'
5836 -O ==> set operating system to 'os'
5837 -T ==> set image type to 'type'
5838 -C ==> set compression type 'comp'
5839 -a ==> set load address to 'addr' (hex)
5840 -e ==> set entry point to 'ep' (hex)
5841 -n ==> set image name to 'name'
5842 -d ==> use image data from 'datafile'
5844 Right now, all Linux kernels for PowerPC systems use the same load
5845 address (0x00000000), but the entry point address depends on the
5848 - 2.2.x kernels have the entry point at 0x0000000C,
5849 - 2.3.x and later kernels have the entry point at 0x00000000.
5851 So a typical call to build a U-Boot image would read:
5853 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
5854 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
5855 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz \
5856 > examples/uImage.TQM850L
5857 Image Name: 2.4.4 kernel for TQM850L
5858 Created: Wed Jul 19 02:34:59 2000
5859 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5860 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
5861 Load Address: 0x00000000
5862 Entry Point: 0x00000000
5864 To verify the contents of the image (or check for corruption):
5866 -> tools/mkimage -l examples/uImage.TQM850L
5867 Image Name: 2.4.4 kernel for TQM850L
5868 Created: Wed Jul 19 02:34:59 2000
5869 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5870 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
5871 Load Address: 0x00000000
5872 Entry Point: 0x00000000
5874 NOTE: for embedded systems where boot time is critical you can trade
5875 speed for memory and install an UNCOMPRESSED image instead: this
5876 needs more space in Flash, but boots much faster since it does not
5877 need to be uncompressed:
5879 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz
5880 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
5881 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
5882 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux \
5883 > examples/uImage.TQM850L-uncompressed
5884 Image Name: 2.4.4 kernel for TQM850L
5885 Created: Wed Jul 19 02:34:59 2000
5886 Image Type: PowerPC Linux Kernel Image (uncompressed)
5887 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
5888 Load Address: 0x00000000
5889 Entry Point: 0x00000000
5892 Similar you can build U-Boot images from a 'ramdisk.image.gz' file
5893 when your kernel is intended to use an initial ramdisk:
5895 -> tools/mkimage -n 'Simple Ramdisk Image' \
5896 > -A ppc -O linux -T ramdisk -C gzip \
5897 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
5898 Image Name: Simple Ramdisk Image
5899 Created: Wed Jan 12 14:01:50 2000
5900 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5901 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
5902 Load Address: 0x00000000
5903 Entry Point: 0x00000000
5905 The "dumpimage" is a tool to disassemble images built by mkimage. Its "-i"
5906 option performs the converse operation of the mkimage's second form (the "-d"
5907 option). Given an image built by mkimage, the dumpimage extracts a "data file"
5910 tools/dumpimage -i image -T type -p position data_file
5911 -i ==> extract from the 'image' a specific 'data_file'
5912 -T ==> set image type to 'type'
5913 -p ==> 'position' (starting at 0) of the 'data_file' inside the 'image'
5916 Installing a Linux Image:
5917 -------------------------
5919 To downloading a U-Boot image over the serial (console) interface,
5920 you must convert the image to S-Record format:
5922 objcopy -I binary -O srec examples/image examples/image.srec
5924 The 'objcopy' does not understand the information in the U-Boot
5925 image header, so the resulting S-Record file will be relative to
5926 address 0x00000000. To load it to a given address, you need to
5927 specify the target address as 'offset' parameter with the 'loads'
5930 Example: install the image to address 0x40100000 (which on the
5931 TQM8xxL is in the first Flash bank):
5933 => erase 40100000 401FFFFF
5939 ## Ready for S-Record download ...
5940 ~>examples/image.srec
5941 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
5943 15989 15990 15991 15992
5944 [file transfer complete]
5946 ## Start Addr = 0x00000000
5949 You can check the success of the download using the 'iminfo' command;
5950 this includes a checksum verification so you can be sure no data
5951 corruption happened:
5955 ## Checking Image at 40100000 ...
5956 Image Name: 2.2.13 for initrd on TQM850L
5957 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5958 Data Size: 335725 Bytes = 327 kB = 0 MB
5959 Load Address: 00000000
5960 Entry Point: 0000000c
5961 Verifying Checksum ... OK
5967 The "bootm" command is used to boot an application that is stored in
5968 memory (RAM or Flash). In case of a Linux kernel image, the contents
5969 of the "bootargs" environment variable is passed to the kernel as
5970 parameters. You can check and modify this variable using the
5971 "printenv" and "setenv" commands:
5974 => printenv bootargs
5975 bootargs=root=/dev/ram
5977 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5979 => printenv bootargs
5980 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5983 ## Booting Linux kernel at 40020000 ...
5984 Image Name: 2.2.13 for NFS on TQM850L
5985 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5986 Data Size: 381681 Bytes = 372 kB = 0 MB
5987 Load Address: 00000000
5988 Entry Point: 0000000c
5989 Verifying Checksum ... OK
5990 Uncompressing Kernel Image ... OK
5991 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
5992 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5993 time_init: decrementer frequency = 187500000/60
5994 Calibrating delay loop... 49.77 BogoMIPS
5995 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
5998 If you want to boot a Linux kernel with initial RAM disk, you pass
5999 the memory addresses of both the kernel and the initrd image (PPBCOOT
6000 format!) to the "bootm" command:
6002 => imi 40100000 40200000
6004 ## Checking Image at 40100000 ...
6005 Image Name: 2.2.13 for initrd on TQM850L
6006 Image Type: PowerPC Linux Kernel Image (gzip compressed)
6007 Data Size: 335725 Bytes = 327 kB = 0 MB
6008 Load Address: 00000000
6009 Entry Point: 0000000c
6010 Verifying Checksum ... OK
6012 ## Checking Image at 40200000 ...
6013 Image Name: Simple Ramdisk Image
6014 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
6015 Data Size: 566530 Bytes = 553 kB = 0 MB
6016 Load Address: 00000000
6017 Entry Point: 00000000
6018 Verifying Checksum ... OK
6020 => bootm 40100000 40200000
6021 ## Booting Linux kernel at 40100000 ...
6022 Image Name: 2.2.13 for initrd on TQM850L
6023 Image Type: PowerPC Linux Kernel Image (gzip compressed)
6024 Data Size: 335725 Bytes = 327 kB = 0 MB
6025 Load Address: 00000000
6026 Entry Point: 0000000c
6027 Verifying Checksum ... OK
6028 Uncompressing Kernel Image ... OK
6029 ## Loading RAMDisk Image at 40200000 ...
6030 Image Name: Simple Ramdisk Image
6031 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
6032 Data Size: 566530 Bytes = 553 kB = 0 MB
6033 Load Address: 00000000
6034 Entry Point: 00000000
6035 Verifying Checksum ... OK
6036 Loading Ramdisk ... OK
6037 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
6038 Boot arguments: root=/dev/ram
6039 time_init: decrementer frequency = 187500000/60
6040 Calibrating delay loop... 49.77 BogoMIPS
6042 RAMDISK: Compressed image found at block 0
6043 VFS: Mounted root (ext2 filesystem).
6047 Boot Linux and pass a flat device tree:
6050 First, U-Boot must be compiled with the appropriate defines. See the section
6051 titled "Linux Kernel Interface" above for a more in depth explanation. The
6052 following is an example of how to start a kernel and pass an updated
6058 oft=oftrees/mpc8540ads.dtb
6059 => tftp $oftaddr $oft
6060 Speed: 1000, full duplex
6062 TFTP from server 192.168.1.1; our IP address is 192.168.1.101
6063 Filename 'oftrees/mpc8540ads.dtb'.
6064 Load address: 0x300000
6067 Bytes transferred = 4106 (100a hex)
6068 => tftp $loadaddr $bootfile
6069 Speed: 1000, full duplex
6071 TFTP from server 192.168.1.1; our IP address is 192.168.1.2
6073 Load address: 0x200000
6074 Loading:############
6076 Bytes transferred = 1029407 (fb51f hex)
6081 => bootm $loadaddr - $oftaddr
6082 ## Booting image at 00200000 ...
6083 Image Name: Linux-2.6.17-dirty
6084 Image Type: PowerPC Linux Kernel Image (gzip compressed)
6085 Data Size: 1029343 Bytes = 1005.2 kB
6086 Load Address: 00000000
6087 Entry Point: 00000000
6088 Verifying Checksum ... OK
6089 Uncompressing Kernel Image ... OK
6090 Booting using flat device tree at 0x300000
6091 Using MPC85xx ADS machine description
6092 Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb
6096 More About U-Boot Image Types:
6097 ------------------------------
6099 U-Boot supports the following image types:
6101 "Standalone Programs" are directly runnable in the environment
6102 provided by U-Boot; it is expected that (if they behave
6103 well) you can continue to work in U-Boot after return from
6104 the Standalone Program.
6105 "OS Kernel Images" are usually images of some Embedded OS which
6106 will take over control completely. Usually these programs
6107 will install their own set of exception handlers, device
6108 drivers, set up the MMU, etc. - this means, that you cannot
6109 expect to re-enter U-Boot except by resetting the CPU.
6110 "RAMDisk Images" are more or less just data blocks, and their
6111 parameters (address, size) are passed to an OS kernel that is
6113 "Multi-File Images" contain several images, typically an OS
6114 (Linux) kernel image and one or more data images like
6115 RAMDisks. This construct is useful for instance when you want
6116 to boot over the network using BOOTP etc., where the boot
6117 server provides just a single image file, but you want to get
6118 for instance an OS kernel and a RAMDisk image.
6120 "Multi-File Images" start with a list of image sizes, each
6121 image size (in bytes) specified by an "uint32_t" in network
6122 byte order. This list is terminated by an "(uint32_t)0".
6123 Immediately after the terminating 0 follow the images, one by
6124 one, all aligned on "uint32_t" boundaries (size rounded up to
6125 a multiple of 4 bytes).
6127 "Firmware Images" are binary images containing firmware (like
6128 U-Boot or FPGA images) which usually will be programmed to
6131 "Script files" are command sequences that will be executed by
6132 U-Boot's command interpreter; this feature is especially
6133 useful when you configure U-Boot to use a real shell (hush)
6134 as command interpreter.
6136 Booting the Linux zImage:
6137 -------------------------
6139 On some platforms, it's possible to boot Linux zImage. This is done
6140 using the "bootz" command. The syntax of "bootz" command is the same
6141 as the syntax of "bootm" command.
6143 Note, defining the CONFIG_SUPPORT_RAW_INITRD allows user to supply
6144 kernel with raw initrd images. The syntax is slightly different, the
6145 address of the initrd must be augmented by it's size, in the following
6146 format: "<initrd addres>:<initrd size>".
6152 One of the features of U-Boot is that you can dynamically load and
6153 run "standalone" applications, which can use some resources of
6154 U-Boot like console I/O functions or interrupt services.
6156 Two simple examples are included with the sources:
6161 'examples/hello_world.c' contains a small "Hello World" Demo
6162 application; it is automatically compiled when you build U-Boot.
6163 It's configured to run at address 0x00040004, so you can play with it
6167 ## Ready for S-Record download ...
6168 ~>examples/hello_world.srec
6169 1 2 3 4 5 6 7 8 9 10 11 ...
6170 [file transfer complete]
6172 ## Start Addr = 0x00040004
6174 => go 40004 Hello World! This is a test.
6175 ## Starting application at 0x00040004 ...
6186 Hit any key to exit ...
6188 ## Application terminated, rc = 0x0
6190 Another example, which demonstrates how to register a CPM interrupt
6191 handler with the U-Boot code, can be found in 'examples/timer.c'.
6192 Here, a CPM timer is set up to generate an interrupt every second.
6193 The interrupt service routine is trivial, just printing a '.'
6194 character, but this is just a demo program. The application can be
6195 controlled by the following keys:
6197 ? - print current values og the CPM Timer registers
6198 b - enable interrupts and start timer
6199 e - stop timer and disable interrupts
6200 q - quit application
6203 ## Ready for S-Record download ...
6204 ~>examples/timer.srec
6205 1 2 3 4 5 6 7 8 9 10 11 ...
6206 [file transfer complete]
6208 ## Start Addr = 0x00040004
6211 ## Starting application at 0x00040004 ...
6214 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
6217 [q, b, e, ?] Set interval 1000000 us
6220 [q, b, e, ?] ........
6221 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
6224 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
6227 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
6230 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
6232 [q, b, e, ?] ...Stopping timer
6234 [q, b, e, ?] ## Application terminated, rc = 0x0
6240 Over time, many people have reported problems when trying to use the
6241 "minicom" terminal emulation program for serial download. I (wd)
6242 consider minicom to be broken, and recommend not to use it. Under
6243 Unix, I recommend to use C-Kermit for general purpose use (and
6244 especially for kermit binary protocol download ("loadb" command), and
6245 use "cu" for S-Record download ("loads" command). See
6246 http://www.denx.de/wiki/view/DULG/SystemSetup#Section_4.3.
6247 for help with kermit.
6250 Nevertheless, if you absolutely want to use it try adding this
6251 configuration to your "File transfer protocols" section:
6253 Name Program Name U/D FullScr IO-Red. Multi
6254 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
6255 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
6261 Starting at version 0.9.2, U-Boot supports NetBSD both as host
6262 (build U-Boot) and target system (boots NetBSD/mpc8xx).
6264 Building requires a cross environment; it is known to work on
6265 NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
6266 need gmake since the Makefiles are not compatible with BSD make).
6267 Note that the cross-powerpc package does not install include files;
6268 attempting to build U-Boot will fail because <machine/ansi.h> is
6269 missing. This file has to be installed and patched manually:
6271 # cd /usr/pkg/cross/powerpc-netbsd/include
6273 # ln -s powerpc machine
6274 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
6275 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
6277 Native builds *don't* work due to incompatibilities between native
6278 and U-Boot include files.
6280 Booting assumes that (the first part of) the image booted is a
6281 stage-2 loader which in turn loads and then invokes the kernel
6282 proper. Loader sources will eventually appear in the NetBSD source
6283 tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
6284 meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz
6287 Implementation Internals:
6288 =========================
6290 The following is not intended to be a complete description of every
6291 implementation detail. However, it should help to understand the
6292 inner workings of U-Boot and make it easier to port it to custom
6296 Initial Stack, Global Data:
6297 ---------------------------
6299 The implementation of U-Boot is complicated by the fact that U-Boot
6300 starts running out of ROM (flash memory), usually without access to
6301 system RAM (because the memory controller is not initialized yet).
6302 This means that we don't have writable Data or BSS segments, and BSS
6303 is not initialized as zero. To be able to get a C environment working
6304 at all, we have to allocate at least a minimal stack. Implementation
6305 options for this are defined and restricted by the CPU used: Some CPU
6306 models provide on-chip memory (like the IMMR area on MPC8xx and
6307 MPC826x processors), on others (parts of) the data cache can be
6308 locked as (mis-) used as memory, etc.
6310 Chris Hallinan posted a good summary of these issues to the
6311 U-Boot mailing list:
6313 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
6314 From: "Chris Hallinan" <clh@net1plus.com>
6315 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
6318 Correct me if I'm wrong, folks, but the way I understand it
6319 is this: Using DCACHE as initial RAM for Stack, etc, does not
6320 require any physical RAM backing up the cache. The cleverness
6321 is that the cache is being used as a temporary supply of
6322 necessary storage before the SDRAM controller is setup. It's
6323 beyond the scope of this list to explain the details, but you
6324 can see how this works by studying the cache architecture and
6325 operation in the architecture and processor-specific manuals.
6327 OCM is On Chip Memory, which I believe the 405GP has 4K. It
6328 is another option for the system designer to use as an
6329 initial stack/RAM area prior to SDRAM being available. Either
6330 option should work for you. Using CS 4 should be fine if your
6331 board designers haven't used it for something that would
6332 cause you grief during the initial boot! It is frequently not
6335 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere
6336 with your processor/board/system design. The default value
6337 you will find in any recent u-boot distribution in
6338 walnut.h should work for you. I'd set it to a value larger
6339 than your SDRAM module. If you have a 64MB SDRAM module, set
6340 it above 400_0000. Just make sure your board has no resources
6341 that are supposed to respond to that address! That code in
6342 start.S has been around a while and should work as is when
6343 you get the config right.
6348 It is essential to remember this, since it has some impact on the C
6349 code for the initialization procedures:
6351 * Initialized global data (data segment) is read-only. Do not attempt
6354 * Do not use any uninitialized global data (or implicitly initialized
6355 as zero data - BSS segment) at all - this is undefined, initiali-
6356 zation is performed later (when relocating to RAM).
6358 * Stack space is very limited. Avoid big data buffers or things like
6361 Having only the stack as writable memory limits means we cannot use
6362 normal global data to share information between the code. But it
6363 turned out that the implementation of U-Boot can be greatly
6364 simplified by making a global data structure (gd_t) available to all
6365 functions. We could pass a pointer to this data as argument to _all_
6366 functions, but this would bloat the code. Instead we use a feature of
6367 the GCC compiler (Global Register Variables) to share the data: we
6368 place a pointer (gd) to the global data into a register which we
6369 reserve for this purpose.
6371 When choosing a register for such a purpose we are restricted by the
6372 relevant (E)ABI specifications for the current architecture, and by
6373 GCC's implementation.
6375 For PowerPC, the following registers have specific use:
6377 R2: reserved for system use
6378 R3-R4: parameter passing and return values
6379 R5-R10: parameter passing
6380 R13: small data area pointer
6384 (U-Boot also uses R12 as internal GOT pointer. r12
6385 is a volatile register so r12 needs to be reset when
6386 going back and forth between asm and C)
6388 ==> U-Boot will use R2 to hold a pointer to the global data
6390 Note: on PPC, we could use a static initializer (since the
6391 address of the global data structure is known at compile time),
6392 but it turned out that reserving a register results in somewhat
6393 smaller code - although the code savings are not that big (on
6394 average for all boards 752 bytes for the whole U-Boot image,
6395 624 text + 127 data).
6397 On Blackfin, the normal C ABI (except for P3) is followed as documented here:
6398 http://docs.blackfin.uclinux.org/doku.php?id=application_binary_interface
6400 ==> U-Boot will use P3 to hold a pointer to the global data
6402 On ARM, the following registers are used:
6404 R0: function argument word/integer result
6405 R1-R3: function argument word
6406 R9: platform specific
6407 R10: stack limit (used only if stack checking is enabled)
6408 R11: argument (frame) pointer
6409 R12: temporary workspace
6412 R15: program counter
6414 ==> U-Boot will use R9 to hold a pointer to the global data
6416 Note: on ARM, only R_ARM_RELATIVE relocations are supported.
6418 On Nios II, the ABI is documented here:
6419 http://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf
6421 ==> U-Boot will use gp to hold a pointer to the global data
6423 Note: on Nios II, we give "-G0" option to gcc and don't use gp
6424 to access small data sections, so gp is free.
6426 On NDS32, the following registers are used:
6428 R0-R1: argument/return
6430 R15: temporary register for assembler
6431 R16: trampoline register
6432 R28: frame pointer (FP)
6433 R29: global pointer (GP)
6434 R30: link register (LP)
6435 R31: stack pointer (SP)
6436 PC: program counter (PC)
6438 ==> U-Boot will use R10 to hold a pointer to the global data
6440 NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope,
6441 or current versions of GCC may "optimize" the code too much.
6446 U-Boot runs in system state and uses physical addresses, i.e. the
6447 MMU is not used either for address mapping nor for memory protection.
6449 The available memory is mapped to fixed addresses using the memory
6450 controller. In this process, a contiguous block is formed for each
6451 memory type (Flash, SDRAM, SRAM), even when it consists of several
6452 physical memory banks.
6454 U-Boot is installed in the first 128 kB of the first Flash bank (on
6455 TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
6456 booting and sizing and initializing DRAM, the code relocates itself
6457 to the upper end of DRAM. Immediately below the U-Boot code some
6458 memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN
6459 configuration setting]. Below that, a structure with global Board
6460 Info data is placed, followed by the stack (growing downward).
6462 Additionally, some exception handler code is copied to the low 8 kB
6463 of DRAM (0x00000000 ... 0x00001FFF).
6465 So a typical memory configuration with 16 MB of DRAM could look like
6468 0x0000 0000 Exception Vector code
6471 0x0000 2000 Free for Application Use
6477 0x00FB FF20 Monitor Stack (Growing downward)
6478 0x00FB FFAC Board Info Data and permanent copy of global data
6479 0x00FC 0000 Malloc Arena
6482 0x00FE 0000 RAM Copy of Monitor Code
6483 ... eventually: LCD or video framebuffer
6484 ... eventually: pRAM (Protected RAM - unchanged by reset)
6485 0x00FF FFFF [End of RAM]
6488 System Initialization:
6489 ----------------------
6491 In the reset configuration, U-Boot starts at the reset entry point
6492 (on most PowerPC systems at address 0x00000100). Because of the reset
6493 configuration for CS0# this is a mirror of the on board Flash memory.
6494 To be able to re-map memory U-Boot then jumps to its link address.
6495 To be able to implement the initialization code in C, a (small!)
6496 initial stack is set up in the internal Dual Ported RAM (in case CPUs
6497 which provide such a feature like MPC8xx or MPC8260), or in a locked
6498 part of the data cache. After that, U-Boot initializes the CPU core,
6499 the caches and the SIU.
6501 Next, all (potentially) available memory banks are mapped using a
6502 preliminary mapping. For example, we put them on 512 MB boundaries
6503 (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
6504 on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
6505 programmed for SDRAM access. Using the temporary configuration, a
6506 simple memory test is run that determines the size of the SDRAM
6509 When there is more than one SDRAM bank, and the banks are of
6510 different size, the largest is mapped first. For equal size, the first
6511 bank (CS2#) is mapped first. The first mapping is always for address
6512 0x00000000, with any additional banks following immediately to create
6513 contiguous memory starting from 0.
6515 Then, the monitor installs itself at the upper end of the SDRAM area
6516 and allocates memory for use by malloc() and for the global Board
6517 Info data; also, the exception vector code is copied to the low RAM
6518 pages, and the final stack is set up.
6520 Only after this relocation will you have a "normal" C environment;
6521 until that you are restricted in several ways, mostly because you are
6522 running from ROM, and because the code will have to be relocated to a
6526 U-Boot Porting Guide:
6527 ----------------------
6529 [Based on messages by Jerry Van Baren in the U-Boot-Users mailing
6533 int main(int argc, char *argv[])
6535 sighandler_t no_more_time;
6537 signal(SIGALRM, no_more_time);
6538 alarm(PROJECT_DEADLINE - toSec (3 * WEEK));
6540 if (available_money > available_manpower) {
6541 Pay consultant to port U-Boot;
6545 Download latest U-Boot source;
6547 Subscribe to u-boot mailing list;
6550 email("Hi, I am new to U-Boot, how do I get started?");
6553 Read the README file in the top level directory;
6554 Read http://www.denx.de/twiki/bin/view/DULG/Manual;
6555 Read applicable doc/*.README;
6556 Read the source, Luke;
6557 /* find . -name "*.[chS]" | xargs grep -i <keyword> */
6560 if (available_money > toLocalCurrency ($2500))
6563 Add a lot of aggravation and time;
6565 if (a similar board exists) { /* hopefully... */
6566 cp -a board/<similar> board/<myboard>
6567 cp include/configs/<similar>.h include/configs/<myboard>.h
6569 Create your own board support subdirectory;
6570 Create your own board include/configs/<myboard>.h file;
6572 Edit new board/<myboard> files
6573 Edit new include/configs/<myboard>.h
6578 Add / modify source code;
6582 email("Hi, I am having problems...");
6584 Send patch file to the U-Boot email list;
6585 if (reasonable critiques)
6586 Incorporate improvements from email list code review;
6588 Defend code as written;
6594 void no_more_time (int sig)
6603 All contributions to U-Boot should conform to the Linux kernel
6604 coding style; see the file "Documentation/CodingStyle" and the script
6605 "scripts/Lindent" in your Linux kernel source directory.
6607 Source files originating from a different project (for example the
6608 MTD subsystem) are generally exempt from these guidelines and are not
6609 reformatted to ease subsequent migration to newer versions of those
6612 Please note that U-Boot is implemented in C (and to some small parts in
6613 Assembler); no C++ is used, so please do not use C++ style comments (//)
6616 Please also stick to the following formatting rules:
6617 - remove any trailing white space
6618 - use TAB characters for indentation and vertical alignment, not spaces
6619 - make sure NOT to use DOS '\r\n' line feeds
6620 - do not add more than 2 consecutive empty lines to source files
6621 - do not add trailing empty lines to source files
6623 Submissions which do not conform to the standards may be returned
6624 with a request to reformat the changes.
6630 Since the number of patches for U-Boot is growing, we need to
6631 establish some rules. Submissions which do not conform to these rules
6632 may be rejected, even when they contain important and valuable stuff.
6634 Please see http://www.denx.de/wiki/U-Boot/Patches for details.
6636 Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>;
6637 see http://lists.denx.de/mailman/listinfo/u-boot
6639 When you send a patch, please include the following information with
6642 * For bug fixes: a description of the bug and how your patch fixes
6643 this bug. Please try to include a way of demonstrating that the
6644 patch actually fixes something.
6646 * For new features: a description of the feature and your
6649 * A CHANGELOG entry as plaintext (separate from the patch)
6651 * For major contributions, your entry to the CREDITS file
6653 * When you add support for a new board, don't forget to add a
6654 maintainer e-mail address to the boards.cfg file, too.
6656 * If your patch adds new configuration options, don't forget to
6657 document these in the README file.
6659 * The patch itself. If you are using git (which is *strongly*
6660 recommended) you can easily generate the patch using the
6661 "git format-patch". If you then use "git send-email" to send it to
6662 the U-Boot mailing list, you will avoid most of the common problems
6663 with some other mail clients.
6665 If you cannot use git, use "diff -purN OLD NEW". If your version of
6666 diff does not support these options, then get the latest version of
6669 The current directory when running this command shall be the parent
6670 directory of the U-Boot source tree (i. e. please make sure that
6671 your patch includes sufficient directory information for the
6674 We prefer patches as plain text. MIME attachments are discouraged,
6675 and compressed attachments must not be used.
6677 * If one logical set of modifications affects or creates several
6678 files, all these changes shall be submitted in a SINGLE patch file.
6680 * Changesets that contain different, unrelated modifications shall be
6681 submitted as SEPARATE patches, one patch per changeset.
6686 * Before sending the patch, run the MAKEALL script on your patched
6687 source tree and make sure that no errors or warnings are reported
6688 for any of the boards.
6690 * Keep your modifications to the necessary minimum: A patch
6691 containing several unrelated changes or arbitrary reformats will be
6692 returned with a request to re-formatting / split it.
6694 * If you modify existing code, make sure that your new code does not
6695 add to the memory footprint of the code ;-) Small is beautiful!
6696 When adding new features, these should compile conditionally only
6697 (using #ifdef), and the resulting code with the new feature
6698 disabled must not need more memory than the old code without your
6701 * Remember that there is a size limit of 100 kB per message on the
6702 u-boot mailing list. Bigger patches will be moderated. If they are
6703 reasonable and not too big, they will be acknowledged. But patches
6704 bigger than the size limit should be avoided.
projects / karo-tx-uboot.git / blob