2 # (C) Copyright 2000 - 2013
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
53 on the mailing list - please search the archive before asking FAQ's.
54 Please see http://lists.denx.de/pipermail/u-boot and
55 http://dir.gmane.org/gmane.comp.boot-loaders.u-boot
58 Where to get source code:
59 =========================
61 The U-Boot source code is maintained in the git repository at
62 git://www.denx.de/git/u-boot.git ; you can browse it online at
63 http://www.denx.de/cgi-bin/gitweb.cgi?p=u-boot.git;a=summary
65 The "snapshot" links on this page allow you to download tarballs of
66 any version you might be interested in. Official releases are also
67 available for FTP download from the ftp://ftp.denx.de/pub/u-boot/
70 Pre-built (and tested) images are available from
71 ftp://ftp.denx.de/pub/u-boot/images/
77 - start from 8xxrom sources
78 - create PPCBoot project (http://sourceforge.net/projects/ppcboot)
80 - make it easier to add custom boards
81 - make it possible to add other [PowerPC] CPUs
82 - extend functions, especially:
83 * Provide extended interface to Linux boot loader
86 * PCMCIA / CompactFlash / ATA disk / SCSI ... boot
87 - create ARMBoot project (http://sourceforge.net/projects/armboot)
88 - add other CPU families (starting with ARM)
89 - create U-Boot project (http://sourceforge.net/projects/u-boot)
90 - current project page: see http://www.denx.de/wiki/U-Boot
96 The "official" name of this project is "Das U-Boot". The spelling
97 "U-Boot" shall be used in all written text (documentation, comments
98 in source files etc.). Example:
100 This is the README file for the U-Boot project.
102 File names etc. shall be based on the string "u-boot". Examples:
104 include/asm-ppc/u-boot.h
106 #include <asm/u-boot.h>
108 Variable names, preprocessor constants etc. shall be either based on
109 the string "u_boot" or on "U_BOOT". Example:
111 U_BOOT_VERSION u_boot_logo
112 IH_OS_U_BOOT u_boot_hush_start
118 Starting with the release in October 2008, the names of the releases
119 were changed from numerical release numbers without deeper meaning
120 into a time stamp based numbering. Regular releases are identified by
121 names consisting of the calendar year and month of the release date.
122 Additional fields (if present) indicate release candidates or bug fix
123 releases in "stable" maintenance trees.
126 U-Boot v2009.11 - Release November 2009
127 U-Boot v2009.11.1 - Release 1 in version November 2009 stable tree
128 U-Boot v2010.09-rc1 - Release candiate 1 for September 2010 release
134 /arch Architecture specific files
135 /arc Files generic to ARC architecture
136 /cpu CPU specific files
137 /arc700 Files specific to ARC 700 CPUs
138 /lib Architecture specific library files
139 /arm Files generic to ARM architecture
140 /cpu CPU specific files
141 /arm720t Files specific to ARM 720 CPUs
142 /arm920t Files specific to ARM 920 CPUs
143 /at91 Files specific to Atmel AT91RM9200 CPU
144 /imx Files specific to Freescale MC9328 i.MX CPUs
145 /s3c24x0 Files specific to Samsung S3C24X0 CPUs
146 /arm926ejs Files specific to ARM 926 CPUs
147 /arm1136 Files specific to ARM 1136 CPUs
148 /pxa Files specific to Intel XScale PXA CPUs
149 /sa1100 Files specific to Intel StrongARM SA1100 CPUs
150 /lib Architecture specific library files
151 /avr32 Files generic to AVR32 architecture
152 /cpu CPU specific files
153 /lib Architecture specific library files
154 /blackfin Files generic to Analog Devices Blackfin architecture
155 /cpu CPU specific files
156 /lib Architecture specific library files
157 /m68k Files generic to m68k architecture
158 /cpu CPU specific files
159 /mcf52x2 Files specific to Freescale ColdFire MCF52x2 CPUs
160 /mcf5227x Files specific to Freescale ColdFire MCF5227x CPUs
161 /mcf532x Files specific to Freescale ColdFire MCF5329 CPUs
162 /mcf5445x Files specific to Freescale ColdFire MCF5445x CPUs
163 /mcf547x_8x Files specific to Freescale ColdFire MCF547x_8x CPUs
164 /lib Architecture specific library files
165 /microblaze Files generic to microblaze architecture
166 /cpu CPU specific files
167 /lib Architecture specific library files
168 /mips Files generic to MIPS architecture
169 /cpu CPU specific files
170 /mips32 Files specific to MIPS32 CPUs
171 /mips64 Files specific to MIPS64 CPUs
172 /lib Architecture specific library files
173 /nds32 Files generic to NDS32 architecture
174 /cpu CPU specific files
175 /n1213 Files specific to Andes Technology N1213 CPUs
176 /lib Architecture specific library files
177 /nios2 Files generic to Altera NIOS2 architecture
178 /cpu CPU specific files
179 /lib Architecture specific library files
180 /openrisc Files generic to OpenRISC architecture
181 /cpu CPU specific files
182 /lib Architecture specific library files
183 /powerpc Files generic to PowerPC architecture
184 /cpu CPU specific files
185 /mpc5xx Files specific to Freescale MPC5xx CPUs
186 /mpc5xxx Files specific to Freescale MPC5xxx CPUs
187 /mpc8xx Files specific to Freescale MPC8xx CPUs
188 /mpc8260 Files specific to Freescale MPC8260 CPUs
189 /mpc85xx Files specific to Freescale MPC85xx CPUs
190 /ppc4xx Files specific to AMCC PowerPC 4xx CPUs
191 /lib Architecture specific library files
192 /sh Files generic to SH architecture
193 /cpu CPU specific files
194 /sh2 Files specific to sh2 CPUs
195 /sh3 Files specific to sh3 CPUs
196 /sh4 Files specific to sh4 CPUs
197 /lib Architecture specific library files
198 /sparc Files generic to SPARC architecture
199 /cpu CPU specific files
200 /leon2 Files specific to Gaisler LEON2 SPARC CPU
201 /leon3 Files specific to Gaisler LEON3 SPARC CPU
202 /lib Architecture specific library files
203 /x86 Files generic to x86 architecture
204 /cpu CPU specific files
205 /lib Architecture specific library files
206 /api Machine/arch independent API for external apps
207 /board Board dependent files
208 /common Misc architecture independent functions
209 /disk Code for disk drive partition handling
210 /doc Documentation (don't expect too much)
211 /drivers Commonly used device drivers
212 /dts Contains Makefile for building internal U-Boot fdt.
213 /examples Example code for standalone applications, etc.
214 /fs Filesystem code (cramfs, ext2, jffs2, etc.)
215 /include Header Files
216 /lib Files generic to all architectures
217 /libfdt Library files to support flattened device trees
218 /lzma Library files to support LZMA decompression
219 /lzo Library files to support LZO decompression
221 /post Power On Self Test
222 /spl Secondary Program Loader framework
223 /tools Tools to build S-Record or U-Boot images, etc.
225 Software Configuration:
226 =======================
228 Configuration is usually done using C preprocessor defines; the
229 rationale behind that is to avoid dead code whenever possible.
231 There are two classes of configuration variables:
233 * Configuration _OPTIONS_:
234 These are selectable by the user and have names beginning with
237 * Configuration _SETTINGS_:
238 These depend on the hardware etc. and should not be meddled with if
239 you don't know what you're doing; they have names beginning with
242 Later we will add a configuration tool - probably similar to or even
243 identical to what's used for the Linux kernel. Right now, we have to
244 do the configuration by hand, which means creating some symbolic
245 links and editing some configuration files. We use the TQM8xxL boards
249 Selection of Processor Architecture and Board Type:
250 ---------------------------------------------------
252 For all supported boards there are ready-to-use default
253 configurations available; just type "make <board_name>_defconfig".
255 Example: For a TQM823L module type:
258 make TQM823L_defconfig
260 For the Cogent platform, you need to specify the CPU type as well;
261 e.g. "make cogent_mpc8xx_defconfig". And also configure the cogent
262 directory according to the instructions in cogent/README.
268 U-Boot can be built natively to run on a Linux host using the 'sandbox'
269 board. This allows feature development which is not board- or architecture-
270 specific to be undertaken on a native platform. The sandbox is also used to
271 run some of U-Boot's tests.
273 See board/sandbox/README.sandbox for more details.
276 Board Initialisation Flow:
277 --------------------------
279 This is the intended start-up flow for boards. This should apply for both
280 SPL and U-Boot proper (i.e. they both follow the same rules). At present SPL
281 mostly uses a separate code path, but the funtion names and roles of each
282 function are the same. Some boards or architectures may not conform to this.
283 At least most ARM boards which use CONFIG_SPL_FRAMEWORK conform to this.
285 Execution starts with start.S with three functions called during init after
286 that. The purpose and limitations of each is described below.
289 - purpose: essential init to permit execution to reach board_init_f()
290 - no global_data or BSS
291 - there is no stack (ARMv7 may have one but it will soon be removed)
292 - must not set up SDRAM or use console
293 - must only do the bare minimum to allow execution to continue to
295 - this is almost never needed
296 - return normally from this function
299 - purpose: set up the machine ready for running board_init_r():
300 i.e. SDRAM and serial UART
301 - global_data is available
303 - BSS is not available, so you cannot use global/static variables,
304 only stack variables and global_data
306 Non-SPL-specific notes:
307 - dram_init() is called to set up DRAM. If already done in SPL this
311 - you can override the entire board_init_f() function with your own
313 - preloader_console_init() can be called here in extremis
314 - should set up SDRAM, and anything needed to make the UART work
315 - these is no need to clear BSS, it will be done by crt0.S
316 - must return normally from this function (don't call board_init_r()
319 Here the BSS is cleared. For SPL, if CONFIG_SPL_STACK_R is defined, then at
320 this point the stack and global_data are relocated to below
321 CONFIG_SPL_STACK_R_ADDR. For non-SPL, U-Boot is relocated to run at the top of
325 - purpose: main execution, common code
326 - global_data is available
328 - BSS is available, all static/global variables can be used
329 - execution eventually continues to main_loop()
331 Non-SPL-specific notes:
332 - U-Boot is relocated to the top of memory and is now running from
336 - stack is optionally in SDRAM, if CONFIG_SPL_STACK_R is defined and
337 CONFIG_SPL_STACK_R_ADDR points into SDRAM
338 - preloader_console_init() can be called here - typically this is
339 done by defining CONFIG_SPL_BOARD_INIT and then supplying a
340 spl_board_init() function containing this call
341 - loads U-Boot or (in falcon mode) Linux
345 Configuration Options:
346 ----------------------
348 Configuration depends on the combination of board and CPU type; all
349 such information is kept in a configuration file
350 "include/configs/<board_name>.h".
352 Example: For a TQM823L module, all configuration settings are in
353 "include/configs/TQM823L.h".
356 Many of the options are named exactly as the corresponding Linux
357 kernel configuration options. The intention is to make it easier to
358 build a config tool - later.
361 The following options need to be configured:
363 - CPU Type: Define exactly one, e.g. CONFIG_MPC85XX.
365 - Board Type: Define exactly one, e.g. CONFIG_MPC8540ADS.
367 - CPU Daughterboard Type: (if CONFIG_ATSTK1000 is defined)
368 Define exactly one, e.g. CONFIG_ATSTK1002
370 - CPU Module Type: (if CONFIG_COGENT is defined)
371 Define exactly one of
373 --- FIXME --- not tested yet:
374 CONFIG_CMA286_60, CONFIG_CMA286_21, CONFIG_CMA286_60P,
375 CONFIG_CMA287_23, CONFIG_CMA287_50
377 - Motherboard Type: (if CONFIG_COGENT is defined)
378 Define exactly one of
379 CONFIG_CMA101, CONFIG_CMA102
381 - Motherboard I/O Modules: (if CONFIG_COGENT is defined)
382 Define one or more of
385 - Motherboard Options: (if CONFIG_CMA101 or CONFIG_CMA102 are defined)
386 Define one or more of
387 CONFIG_LCD_HEARTBEAT - update a character position on
388 the LCD display every second with
391 - Marvell Family Member
392 CONFIG_SYS_MVFS - define it if you want to enable
393 multiple fs option at one time
394 for marvell soc family
396 - 8xx CPU Options: (if using an MPC8xx CPU)
397 CONFIG_8xx_GCLK_FREQ - deprecated: CPU clock if
398 get_gclk_freq() cannot work
399 e.g. if there is no 32KHz
400 reference PIT/RTC clock
401 CONFIG_8xx_OSCLK - PLL input clock (either EXTCLK
404 - 859/866/885 CPU options: (if using a MPC859 or MPC866 or MPC885 CPU):
405 CONFIG_SYS_8xx_CPUCLK_MIN
406 CONFIG_SYS_8xx_CPUCLK_MAX
407 CONFIG_8xx_CPUCLK_DEFAULT
408 See doc/README.MPC866
410 CONFIG_SYS_MEASURE_CPUCLK
412 Define this to measure the actual CPU clock instead
413 of relying on the correctness of the configured
414 values. Mostly useful for board bringup to make sure
415 the PLL is locked at the intended frequency. Note
416 that this requires a (stable) reference clock (32 kHz
417 RTC clock or CONFIG_SYS_8XX_XIN)
419 CONFIG_SYS_DELAYED_ICACHE
421 Define this option if you want to enable the
422 ICache only when Code runs from RAM.
427 Specifies that the core is a 64-bit PowerPC implementation (implements
428 the "64" category of the Power ISA). This is necessary for ePAPR
429 compliance, among other possible reasons.
431 CONFIG_SYS_FSL_TBCLK_DIV
433 Defines the core time base clock divider ratio compared to the
434 system clock. On most PQ3 devices this is 8, on newer QorIQ
435 devices it can be 16 or 32. The ratio varies from SoC to Soc.
437 CONFIG_SYS_FSL_PCIE_COMPAT
439 Defines the string to utilize when trying to match PCIe device
440 tree nodes for the given platform.
442 CONFIG_SYS_PPC_E500_DEBUG_TLB
444 Enables a temporary TLB entry to be used during boot to work
445 around limitations in e500v1 and e500v2 external debugger
446 support. This reduces the portions of the boot code where
447 breakpoints and single stepping do not work. The value of this
448 symbol should be set to the TLB1 entry to be used for this
451 CONFIG_SYS_FSL_ERRATUM_A004510
453 Enables a workaround for erratum A004510. If set,
454 then CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV and
455 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY must be set.
457 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV
458 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV2 (optional)
460 Defines one or two SoC revisions (low 8 bits of SVR)
461 for which the A004510 workaround should be applied.
463 The rest of SVR is either not relevant to the decision
464 of whether the erratum is present (e.g. p2040 versus
465 p2041) or is implied by the build target, which controls
466 whether CONFIG_SYS_FSL_ERRATUM_A004510 is set.
468 See Freescale App Note 4493 for more information about
471 CONFIG_A003399_NOR_WORKAROUND
472 Enables a workaround for IFC erratum A003399. It is only
473 required during NOR boot.
475 CONFIG_A008044_WORKAROUND
476 Enables a workaround for T1040/T1042 erratum A008044. It is only
477 required during NAND boot and valid for Rev 1.0 SoC revision
479 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY
481 This is the value to write into CCSR offset 0x18600
482 according to the A004510 workaround.
484 CONFIG_SYS_FSL_DSP_DDR_ADDR
485 This value denotes start offset of DDR memory which is
486 connected exclusively to the DSP cores.
488 CONFIG_SYS_FSL_DSP_M2_RAM_ADDR
489 This value denotes start offset of M2 memory
490 which is directly connected to the DSP core.
492 CONFIG_SYS_FSL_DSP_M3_RAM_ADDR
493 This value denotes start offset of M3 memory which is directly
494 connected to the DSP core.
496 CONFIG_SYS_FSL_DSP_CCSRBAR_DEFAULT
497 This value denotes start offset of DSP CCSR space.
499 CONFIG_SYS_FSL_SINGLE_SOURCE_CLK
500 Single Source Clock is clocking mode present in some of FSL SoC's.
501 In this mode, a single differential clock is used to supply
502 clocks to the sysclock, ddrclock and usbclock.
504 CONFIG_SYS_CPC_REINIT_F
505 This CONFIG is defined when the CPC is configured as SRAM at the
506 time of U-boot entry and is required to be re-initialized.
509 Indicates this SoC supports deep sleep feature. If deep sleep is
510 supported, core will start to execute uboot when wakes up.
512 - Generic CPU options:
513 CONFIG_SYS_GENERIC_GLOBAL_DATA
514 Defines global data is initialized in generic board board_init_f().
515 If this macro is defined, global data is created and cleared in
516 generic board board_init_f(). Without this macro, architecture/board
517 should initialize global data before calling board_init_f().
519 CONFIG_SYS_BIG_ENDIAN, CONFIG_SYS_LITTLE_ENDIAN
521 Defines the endianess of the CPU. Implementation of those
522 values is arch specific.
525 Freescale DDR driver in use. This type of DDR controller is
526 found in mpc83xx, mpc85xx, mpc86xx as well as some ARM core
529 CONFIG_SYS_FSL_DDR_ADDR
530 Freescale DDR memory-mapped register base.
532 CONFIG_SYS_FSL_DDR_EMU
533 Specify emulator support for DDR. Some DDR features such as
534 deskew training are not available.
536 CONFIG_SYS_FSL_DDRC_GEN1
537 Freescale DDR1 controller.
539 CONFIG_SYS_FSL_DDRC_GEN2
540 Freescale DDR2 controller.
542 CONFIG_SYS_FSL_DDRC_GEN3
543 Freescale DDR3 controller.
545 CONFIG_SYS_FSL_DDRC_GEN4
546 Freescale DDR4 controller.
548 CONFIG_SYS_FSL_DDRC_ARM_GEN3
549 Freescale DDR3 controller for ARM-based SoCs.
552 Board config to use DDR1. It can be enabled for SoCs with
553 Freescale DDR1 or DDR2 controllers, depending on the board
557 Board config to use DDR2. It can be eanbeld for SoCs with
558 Freescale DDR2 or DDR3 controllers, depending on the board
562 Board config to use DDR3. It can be enabled for SoCs with
563 Freescale DDR3 or DDR3L controllers.
566 Board config to use DDR3L. It can be enabled for SoCs with
570 Board config to use DDR4. It can be enabled for SoCs with
573 CONFIG_SYS_FSL_IFC_BE
574 Defines the IFC controller register space as Big Endian
576 CONFIG_SYS_FSL_IFC_LE
577 Defines the IFC controller register space as Little Endian
579 CONFIG_SYS_FSL_PBL_PBI
580 It enables addition of RCW (Power on reset configuration) in built image.
581 Please refer doc/README.pblimage for more details
583 CONFIG_SYS_FSL_PBL_RCW
584 It adds PBI(pre-boot instructions) commands in u-boot build image.
585 PBI commands can be used to configure SoC before it starts the execution.
586 Please refer doc/README.pblimage for more details
589 It adds a target to create boot binary having SPL binary in PBI format
590 concatenated with u-boot binary.
592 CONFIG_SYS_FSL_DDR_BE
593 Defines the DDR controller register space as Big Endian
595 CONFIG_SYS_FSL_DDR_LE
596 Defines the DDR controller register space as Little Endian
598 CONFIG_SYS_FSL_DDR_SDRAM_BASE_PHY
599 Physical address from the view of DDR controllers. It is the
600 same as CONFIG_SYS_DDR_SDRAM_BASE for all Power SoCs. But
601 it could be different for ARM SoCs.
603 CONFIG_SYS_FSL_DDR_INTLV_256B
604 DDR controller interleaving on 256-byte. This is a special
605 interleaving mode, handled by Dickens for Freescale layerscape
608 CONFIG_SYS_FSL_DDR_MAIN_NUM_CTRLS
609 Number of controllers used as main memory.
611 CONFIG_SYS_FSL_OTHER_DDR_NUM_CTRLS
612 Number of controllers used for other than main memory.
614 CONFIG_SYS_FSL_SEC_BE
615 Defines the SEC controller register space as Big Endian
617 CONFIG_SYS_FSL_SEC_LE
618 Defines the SEC controller register space as Little Endian
620 - Intel Monahans options:
621 CONFIG_SYS_MONAHANS_RUN_MODE_OSC_RATIO
623 Defines the Monahans run mode to oscillator
624 ratio. Valid values are 8, 16, 24, 31. The core
625 frequency is this value multiplied by 13 MHz.
627 CONFIG_SYS_MONAHANS_TURBO_RUN_MODE_RATIO
629 Defines the Monahans turbo mode to oscillator
630 ratio. Valid values are 1 (default if undefined) and
631 2. The core frequency as calculated above is multiplied
635 CONFIG_SYS_INIT_SP_OFFSET
637 Offset relative to CONFIG_SYS_SDRAM_BASE for initial stack
638 pointer. This is needed for the temporary stack before
641 CONFIG_SYS_MIPS_CACHE_MODE
643 Cache operation mode for the MIPS CPU.
644 See also arch/mips/include/asm/mipsregs.h.
646 CONF_CM_CACHABLE_NO_WA
649 CONF_CM_CACHABLE_NONCOHERENT
653 CONF_CM_CACHABLE_ACCELERATED
655 CONFIG_SYS_XWAY_EBU_BOOTCFG
657 Special option for Lantiq XWAY SoCs for booting from NOR flash.
658 See also arch/mips/cpu/mips32/start.S.
660 CONFIG_XWAY_SWAP_BYTES
662 Enable compilation of tools/xway-swap-bytes needed for Lantiq
663 XWAY SoCs for booting from NOR flash. The U-Boot image needs to
664 be swapped if a flash programmer is used.
667 CONFIG_SYS_EXCEPTION_VECTORS_HIGH
669 Select high exception vectors of the ARM core, e.g., do not
670 clear the V bit of the c1 register of CP15.
672 CONFIG_SYS_THUMB_BUILD
674 Use this flag to build U-Boot using the Thumb instruction
675 set for ARM architectures. Thumb instruction set provides
676 better code density. For ARM architectures that support
677 Thumb2 this flag will result in Thumb2 code generated by
680 CONFIG_ARM_ERRATA_716044
681 CONFIG_ARM_ERRATA_742230
682 CONFIG_ARM_ERRATA_743622
683 CONFIG_ARM_ERRATA_751472
684 CONFIG_ARM_ERRATA_794072
685 CONFIG_ARM_ERRATA_761320
687 If set, the workarounds for these ARM errata are applied early
688 during U-Boot startup. Note that these options force the
689 workarounds to be applied; no CPU-type/version detection
690 exists, unlike the similar options in the Linux kernel. Do not
691 set these options unless they apply!
694 Generic timer clock source frequency.
696 COUNTER_FREQUENCY_REAL
697 Generic timer clock source frequency if the real clock is
698 different from COUNTER_FREQUENCY, and can only be determined
701 NOTE: The following can be machine specific errata. These
702 do have ability to provide rudimentary version and machine
703 specific checks, but expect no product checks.
704 CONFIG_ARM_ERRATA_430973
705 CONFIG_ARM_ERRATA_454179
706 CONFIG_ARM_ERRATA_621766
707 CONFIG_ARM_ERRATA_798870
708 CONFIG_ARM_ERRATA_801819
711 CONFIG_TEGRA_SUPPORT_NON_SECURE
713 Support executing U-Boot in non-secure (NS) mode. Certain
714 impossible actions will be skipped if the CPU is in NS mode,
715 such as ARM architectural timer initialization.
717 - Linux Kernel Interface:
720 U-Boot stores all clock information in Hz
721 internally. For binary compatibility with older Linux
722 kernels (which expect the clocks passed in the
723 bd_info data to be in MHz) the environment variable
724 "clocks_in_mhz" can be defined so that U-Boot
725 converts clock data to MHZ before passing it to the
727 When CONFIG_CLOCKS_IN_MHZ is defined, a definition of
728 "clocks_in_mhz=1" is automatically included in the
731 CONFIG_MEMSIZE_IN_BYTES [relevant for MIPS only]
733 When transferring memsize parameter to Linux, some versions
734 expect it to be in bytes, others in MB.
735 Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes.
739 New kernel versions are expecting firmware settings to be
740 passed using flattened device trees (based on open firmware
744 * New libfdt-based support
745 * Adds the "fdt" command
746 * The bootm command automatically updates the fdt
748 OF_CPU - The proper name of the cpus node (only required for
749 MPC512X and MPC5xxx based boards).
750 OF_SOC - The proper name of the soc node (only required for
751 MPC512X and MPC5xxx based boards).
752 OF_TBCLK - The timebase frequency.
753 OF_STDOUT_PATH - The path to the console device
755 boards with QUICC Engines require OF_QE to set UCC MAC
758 CONFIG_OF_BOARD_SETUP
760 Board code has addition modification that it wants to make
761 to the flat device tree before handing it off to the kernel
763 CONFIG_OF_SYSTEM_SETUP
765 Other code has addition modification that it wants to make
766 to the flat device tree before handing it off to the kernel.
767 This causes ft_system_setup() to be called before booting
772 This define fills in the correct boot CPU in the boot
773 param header, the default value is zero if undefined.
777 U-Boot can detect if an IDE device is present or not.
778 If not, and this new config option is activated, U-Boot
779 removes the ATA node from the DTS before booting Linux,
780 so the Linux IDE driver does not probe the device and
781 crash. This is needed for buggy hardware (uc101) where
782 no pull down resistor is connected to the signal IDE5V_DD7.
784 CONFIG_MACH_TYPE [relevant for ARM only][mandatory]
786 This setting is mandatory for all boards that have only one
787 machine type and must be used to specify the machine type
788 number as it appears in the ARM machine registry
789 (see http://www.arm.linux.org.uk/developer/machines/).
790 Only boards that have multiple machine types supported
791 in a single configuration file and the machine type is
792 runtime discoverable, do not have to use this setting.
794 - vxWorks boot parameters:
796 bootvx constructs a valid bootline using the following
797 environments variables: bootfile, ipaddr, serverip, hostname.
798 It loads the vxWorks image pointed bootfile.
800 CONFIG_SYS_VXWORKS_BOOT_DEVICE - The vxworks device name
801 CONFIG_SYS_VXWORKS_MAC_PTR - Ethernet 6 byte MA -address
802 CONFIG_SYS_VXWORKS_SERVERNAME - Name of the server
803 CONFIG_SYS_VXWORKS_BOOT_ADDR - Address of boot parameters
805 CONFIG_SYS_VXWORKS_ADD_PARAMS
807 Add it at the end of the bootline. E.g "u=username pw=secret"
809 Note: If a "bootargs" environment is defined, it will overwride
810 the defaults discussed just above.
812 - Cache Configuration:
813 CONFIG_SYS_ICACHE_OFF - Do not enable instruction cache in U-Boot
814 CONFIG_SYS_DCACHE_OFF - Do not enable data cache in U-Boot
815 CONFIG_SYS_L2CACHE_OFF- Do not enable L2 cache in U-Boot
817 - Cache Configuration for ARM:
818 CONFIG_SYS_L2_PL310 - Enable support for ARM PL310 L2 cache
820 CONFIG_SYS_PL310_BASE - Physical base address of PL310
821 controller register space
826 Define this if you want support for Amba PrimeCell PL010 UARTs.
830 Define this if you want support for Amba PrimeCell PL011 UARTs.
834 If you have Amba PrimeCell PL011 UARTs, set this variable to
835 the clock speed of the UARTs.
839 If you have Amba PrimeCell PL010 or PL011 UARTs on your board,
840 define this to a list of base addresses for each (supported)
841 port. See e.g. include/configs/versatile.h
843 CONFIG_PL011_SERIAL_RLCR
845 Some vendor versions of PL011 serial ports (e.g. ST-Ericsson U8500)
846 have separate receive and transmit line control registers. Set
847 this variable to initialize the extra register.
849 CONFIG_PL011_SERIAL_FLUSH_ON_INIT
851 On some platforms (e.g. U8500) U-Boot is loaded by a second stage
852 boot loader that has already initialized the UART. Define this
853 variable to flush the UART at init time.
855 CONFIG_SERIAL_HW_FLOW_CONTROL
857 Define this variable to enable hw flow control in serial driver.
858 Current user of this option is drivers/serial/nsl16550.c driver
861 Depending on board, define exactly one serial port
862 (like CONFIG_8xx_CONS_SMC1, CONFIG_8xx_CONS_SMC2,
863 CONFIG_8xx_CONS_SCC1, ...), or switch off the serial
864 console by defining CONFIG_8xx_CONS_NONE
866 Note: if CONFIG_8xx_CONS_NONE is defined, the serial
867 port routines must be defined elsewhere
868 (i.e. serial_init(), serial_getc(), ...)
871 Enables console device for a color framebuffer. Needs following
872 defines (cf. smiLynxEM, i8042)
873 VIDEO_FB_LITTLE_ENDIAN graphic memory organisation
875 VIDEO_HW_RECTFILL graphic chip supports
878 VIDEO_HW_BITBLT graphic chip supports
879 bit-blit (cf. smiLynxEM)
880 VIDEO_VISIBLE_COLS visible pixel columns
882 VIDEO_VISIBLE_ROWS visible pixel rows
883 VIDEO_PIXEL_SIZE bytes per pixel
884 VIDEO_DATA_FORMAT graphic data format
885 (0-5, cf. cfb_console.c)
886 VIDEO_FB_ADRS framebuffer address
887 VIDEO_KBD_INIT_FCT keyboard int fct
888 (i.e. i8042_kbd_init())
889 VIDEO_TSTC_FCT test char fct
891 VIDEO_GETC_FCT get char fct
893 CONFIG_CONSOLE_CURSOR cursor drawing on/off
894 (requires blink timer
896 CONFIG_SYS_CONSOLE_BLINK_COUNT blink interval (cf. i8042.c)
897 CONFIG_CONSOLE_TIME display time/date info in
899 (requires CONFIG_CMD_DATE)
900 CONFIG_VIDEO_LOGO display Linux logo in
902 CONFIG_VIDEO_BMP_LOGO use bmp_logo.h instead of
903 linux_logo.h for logo.
904 Requires CONFIG_VIDEO_LOGO
905 CONFIG_CONSOLE_EXTRA_INFO
906 additional board info beside
909 When CONFIG_CFB_CONSOLE_ANSI is defined, console will support
910 a limited number of ANSI escape sequences (cursor control,
911 erase functions and limited graphics rendition control).
913 When CONFIG_CFB_CONSOLE is defined, video console is
914 default i/o. Serial console can be forced with
915 environment 'console=serial'.
917 When CONFIG_SILENT_CONSOLE is defined, all console
918 messages (by U-Boot and Linux!) can be silenced with
919 the "silent" environment variable. See
920 doc/README.silent for more information.
922 CONFIG_SYS_CONSOLE_BG_COL: define the backgroundcolor, default
924 CONFIG_SYS_CONSOLE_FG_COL: define the foregroundcolor, default
928 CONFIG_BAUDRATE - in bps
929 Select one of the baudrates listed in
930 CONFIG_SYS_BAUDRATE_TABLE, see below.
931 CONFIG_SYS_BRGCLK_PRESCALE, baudrate prescale
933 - Console Rx buffer length
934 With CONFIG_SYS_SMC_RXBUFLEN it is possible to define
935 the maximum receive buffer length for the SMC.
936 This option is actual only for 82xx and 8xx possible.
937 If using CONFIG_SYS_SMC_RXBUFLEN also CONFIG_SYS_MAXIDLE
938 must be defined, to setup the maximum idle timeout for
941 - Pre-Console Buffer:
942 Prior to the console being initialised (i.e. serial UART
943 initialised etc) all console output is silently discarded.
944 Defining CONFIG_PRE_CONSOLE_BUFFER will cause U-Boot to
945 buffer any console messages prior to the console being
946 initialised to a buffer of size CONFIG_PRE_CON_BUF_SZ
947 bytes located at CONFIG_PRE_CON_BUF_ADDR. The buffer is
948 a circular buffer, so if more than CONFIG_PRE_CON_BUF_SZ
949 bytes are output before the console is initialised, the
950 earlier bytes are discarded.
952 Note that when printing the buffer a copy is made on the
953 stack so CONFIG_PRE_CON_BUF_SZ must fit on the stack.
955 'Sane' compilers will generate smaller code if
956 CONFIG_PRE_CON_BUF_SZ is a power of 2
958 - Safe printf() functions
959 Define CONFIG_SYS_VSNPRINTF to compile in safe versions of
960 the printf() functions. These are defined in
961 include/vsprintf.h and include snprintf(), vsnprintf() and
962 so on. Code size increase is approximately 300-500 bytes.
963 If this option is not given then these functions will
964 silently discard their buffer size argument - this means
965 you are not getting any overflow checking in this case.
967 - Boot Delay: CONFIG_BOOTDELAY - in seconds
968 Delay before automatically booting the default image;
969 set to -1 to disable autoboot.
970 set to -2 to autoboot with no delay and not check for abort
971 (even when CONFIG_ZERO_BOOTDELAY_CHECK is defined).
973 See doc/README.autoboot for these options that
974 work with CONFIG_BOOTDELAY. None are required.
975 CONFIG_BOOT_RETRY_TIME
976 CONFIG_BOOT_RETRY_MIN
977 CONFIG_AUTOBOOT_KEYED
978 CONFIG_AUTOBOOT_PROMPT
979 CONFIG_AUTOBOOT_DELAY_STR
980 CONFIG_AUTOBOOT_STOP_STR
981 CONFIG_ZERO_BOOTDELAY_CHECK
982 CONFIG_RESET_TO_RETRY
986 Only needed when CONFIG_BOOTDELAY is enabled;
987 define a command string that is automatically executed
988 when no character is read on the console interface
989 within "Boot Delay" after reset.
992 This can be used to pass arguments to the bootm
993 command. The value of CONFIG_BOOTARGS goes into the
994 environment value "bootargs".
996 CONFIG_RAMBOOT and CONFIG_NFSBOOT
997 The value of these goes into the environment as
998 "ramboot" and "nfsboot" respectively, and can be used
999 as a convenience, when switching between booting from
1003 CONFIG_BOOTCOUNT_LIMIT
1004 Implements a mechanism for detecting a repeating reboot
1006 http://www.denx.de/wiki/view/DULG/UBootBootCountLimit
1008 CONFIG_BOOTCOUNT_ENV
1009 If no softreset save registers are found on the hardware
1010 "bootcount" is stored in the environment. To prevent a
1011 saveenv on all reboots, the environment variable
1012 "upgrade_available" is used. If "upgrade_available" is
1013 0, "bootcount" is always 0, if "upgrade_available" is
1014 1 "bootcount" is incremented in the environment.
1015 So the Userspace Applikation must set the "upgrade_available"
1016 and "bootcount" variable to 0, if a boot was successfully.
1018 - Pre-Boot Commands:
1021 When this option is #defined, the existence of the
1022 environment variable "preboot" will be checked
1023 immediately before starting the CONFIG_BOOTDELAY
1024 countdown and/or running the auto-boot command resp.
1025 entering interactive mode.
1027 This feature is especially useful when "preboot" is
1028 automatically generated or modified. For an example
1029 see the LWMON board specific code: here "preboot" is
1030 modified when the user holds down a certain
1031 combination of keys on the (special) keyboard when
1034 - Serial Download Echo Mode:
1036 If defined to 1, all characters received during a
1037 serial download (using the "loads" command) are
1038 echoed back. This might be needed by some terminal
1039 emulations (like "cu"), but may as well just take
1040 time on others. This setting #define's the initial
1041 value of the "loads_echo" environment variable.
1043 - Kgdb Serial Baudrate: (if CONFIG_CMD_KGDB is defined)
1044 CONFIG_KGDB_BAUDRATE
1045 Select one of the baudrates listed in
1046 CONFIG_SYS_BAUDRATE_TABLE, see below.
1048 - Monitor Functions:
1049 Monitor commands can be included or excluded
1050 from the build by using the #include files
1051 <config_cmd_all.h> and #undef'ing unwanted
1052 commands, or adding #define's for wanted commands.
1054 The default command configuration includes all commands
1055 except those marked below with a "*".
1057 CONFIG_CMD_AES AES 128 CBC encrypt/decrypt
1058 CONFIG_CMD_ASKENV * ask for env variable
1059 CONFIG_CMD_BDI bdinfo
1060 CONFIG_CMD_BEDBUG * Include BedBug Debugger
1061 CONFIG_CMD_BMP * BMP support
1062 CONFIG_CMD_BSP * Board specific commands
1063 CONFIG_CMD_BOOTD bootd
1064 CONFIG_CMD_BOOTI * ARM64 Linux kernel Image support
1065 CONFIG_CMD_CACHE * icache, dcache
1066 CONFIG_CMD_CLK * clock command support
1067 CONFIG_CMD_CONSOLE coninfo
1068 CONFIG_CMD_CRC32 * crc32
1069 CONFIG_CMD_DATE * support for RTC, date/time...
1070 CONFIG_CMD_DHCP * DHCP support
1071 CONFIG_CMD_DIAG * Diagnostics
1072 CONFIG_CMD_DS4510 * ds4510 I2C gpio commands
1073 CONFIG_CMD_DS4510_INFO * ds4510 I2C info command
1074 CONFIG_CMD_DS4510_MEM * ds4510 I2C eeprom/sram commansd
1075 CONFIG_CMD_DS4510_RST * ds4510 I2C rst command
1076 CONFIG_CMD_DTT * Digital Therm and Thermostat
1077 CONFIG_CMD_ECHO echo arguments
1078 CONFIG_CMD_EDITENV edit env variable
1079 CONFIG_CMD_EEPROM * EEPROM read/write support
1080 CONFIG_CMD_ELF * bootelf, bootvx
1081 CONFIG_CMD_ENV_CALLBACK * display details about env callbacks
1082 CONFIG_CMD_ENV_FLAGS * display details about env flags
1083 CONFIG_CMD_ENV_EXISTS * check existence of env variable
1084 CONFIG_CMD_EXPORTENV * export the environment
1085 CONFIG_CMD_EXT2 * ext2 command support
1086 CONFIG_CMD_EXT4 * ext4 command support
1087 CONFIG_CMD_FS_GENERIC * filesystem commands (e.g. load, ls)
1088 that work for multiple fs types
1089 CONFIG_CMD_FS_UUID * Look up a filesystem UUID
1090 CONFIG_CMD_SAVEENV saveenv
1091 CONFIG_CMD_FDC * Floppy Disk Support
1092 CONFIG_CMD_FAT * FAT command support
1093 CONFIG_CMD_FLASH flinfo, erase, protect
1094 CONFIG_CMD_FPGA FPGA device initialization support
1095 CONFIG_CMD_FUSE * Device fuse support
1096 CONFIG_CMD_GETTIME * Get time since boot
1097 CONFIG_CMD_GO * the 'go' command (exec code)
1098 CONFIG_CMD_GREPENV * search environment
1099 CONFIG_CMD_HASH * calculate hash / digest
1100 CONFIG_CMD_HWFLOW * RTS/CTS hw flow control
1101 CONFIG_CMD_I2C * I2C serial bus support
1102 CONFIG_CMD_IDE * IDE harddisk support
1103 CONFIG_CMD_IMI iminfo
1104 CONFIG_CMD_IMLS List all images found in NOR flash
1105 CONFIG_CMD_IMLS_NAND * List all images found in NAND flash
1106 CONFIG_CMD_IMMAP * IMMR dump support
1107 CONFIG_CMD_IOTRACE * I/O tracing for debugging
1108 CONFIG_CMD_IMPORTENV * import an environment
1109 CONFIG_CMD_INI * import data from an ini file into the env
1110 CONFIG_CMD_IRQ * irqinfo
1111 CONFIG_CMD_ITEST Integer/string test of 2 values
1112 CONFIG_CMD_JFFS2 * JFFS2 Support
1113 CONFIG_CMD_KGDB * kgdb
1114 CONFIG_CMD_LDRINFO * ldrinfo (display Blackfin loader)
1115 CONFIG_CMD_LINK_LOCAL * link-local IP address auto-configuration
1117 CONFIG_CMD_LOADB loadb
1118 CONFIG_CMD_LOADS loads
1119 CONFIG_CMD_MD5SUM * print md5 message digest
1120 (requires CONFIG_CMD_MEMORY and CONFIG_MD5)
1121 CONFIG_CMD_MEMINFO * Display detailed memory information
1122 CONFIG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base,
1124 CONFIG_CMD_MEMTEST * mtest
1125 CONFIG_CMD_MISC Misc functions like sleep etc
1126 CONFIG_CMD_MMC * MMC memory mapped support
1127 CONFIG_CMD_MII * MII utility commands
1128 CONFIG_CMD_MTDPARTS * MTD partition support
1129 CONFIG_CMD_NAND * NAND support
1130 CONFIG_CMD_NET bootp, tftpboot, rarpboot
1131 CONFIG_CMD_NFS NFS support
1132 CONFIG_CMD_PCA953X * PCA953x I2C gpio commands
1133 CONFIG_CMD_PCA953X_INFO * PCA953x I2C gpio info command
1134 CONFIG_CMD_PCI * pciinfo
1135 CONFIG_CMD_PCMCIA * PCMCIA support
1136 CONFIG_CMD_PING * send ICMP ECHO_REQUEST to network
1138 CONFIG_CMD_PORTIO * Port I/O
1139 CONFIG_CMD_READ * Read raw data from partition
1140 CONFIG_CMD_REGINFO * Register dump
1141 CONFIG_CMD_RUN run command in env variable
1142 CONFIG_CMD_SANDBOX * sb command to access sandbox features
1143 CONFIG_CMD_SAVES * save S record dump
1144 CONFIG_CMD_SCSI * SCSI Support
1145 CONFIG_CMD_SDRAM * print SDRAM configuration information
1146 (requires CONFIG_CMD_I2C)
1147 CONFIG_CMD_SETGETDCR Support for DCR Register access
1149 CONFIG_CMD_SF * Read/write/erase SPI NOR flash
1150 CONFIG_CMD_SHA1SUM * print sha1 memory digest
1151 (requires CONFIG_CMD_MEMORY)
1152 CONFIG_CMD_SOFTSWITCH * Soft switch setting command for BF60x
1153 CONFIG_CMD_SOURCE "source" command Support
1154 CONFIG_CMD_SPI * SPI serial bus support
1155 CONFIG_CMD_TFTPSRV * TFTP transfer in server mode
1156 CONFIG_CMD_TFTPPUT * TFTP put command (upload)
1157 CONFIG_CMD_TIME * run command and report execution time (ARM specific)
1158 CONFIG_CMD_TIMER * access to the system tick timer
1159 CONFIG_CMD_USB * USB support
1160 CONFIG_CMD_CDP * Cisco Discover Protocol support
1161 CONFIG_CMD_MFSL * Microblaze FSL support
1162 CONFIG_CMD_XIMG Load part of Multi Image
1163 CONFIG_CMD_UUID * Generate random UUID or GUID string
1165 EXAMPLE: If you want all functions except of network
1166 support you can write:
1168 #include "config_cmd_all.h"
1169 #undef CONFIG_CMD_NET
1172 fdt (flattened device tree) command: CONFIG_OF_LIBFDT
1174 Note: Don't enable the "icache" and "dcache" commands
1175 (configuration option CONFIG_CMD_CACHE) unless you know
1176 what you (and your U-Boot users) are doing. Data
1177 cache cannot be enabled on systems like the 8xx or
1178 8260 (where accesses to the IMMR region must be
1179 uncached), and it cannot be disabled on all other
1180 systems where we (mis-) use the data cache to hold an
1181 initial stack and some data.
1184 XXX - this list needs to get updated!
1186 - Regular expression support:
1188 If this variable is defined, U-Boot is linked against
1189 the SLRE (Super Light Regular Expression) library,
1190 which adds regex support to some commands, as for
1191 example "env grep" and "setexpr".
1195 If this variable is defined, U-Boot will use a device tree
1196 to configure its devices, instead of relying on statically
1197 compiled #defines in the board file. This option is
1198 experimental and only available on a few boards. The device
1199 tree is available in the global data as gd->fdt_blob.
1201 U-Boot needs to get its device tree from somewhere. This can
1202 be done using one of the two options below:
1205 If this variable is defined, U-Boot will embed a device tree
1206 binary in its image. This device tree file should be in the
1207 board directory and called <soc>-<board>.dts. The binary file
1208 is then picked up in board_init_f() and made available through
1209 the global data structure as gd->blob.
1212 If this variable is defined, U-Boot will build a device tree
1213 binary. It will be called u-boot.dtb. Architecture-specific
1214 code will locate it at run-time. Generally this works by:
1216 cat u-boot.bin u-boot.dtb >image.bin
1218 and in fact, U-Boot does this for you, creating a file called
1219 u-boot-dtb.bin which is useful in the common case. You can
1220 still use the individual files if you need something more
1225 If this variable is defined, it enables watchdog
1226 support for the SoC. There must be support in the SoC
1227 specific code for a watchdog. For the 8xx and 8260
1228 CPUs, the SIU Watchdog feature is enabled in the SYPCR
1229 register. When supported for a specific SoC is
1230 available, then no further board specific code should
1231 be needed to use it.
1234 When using a watchdog circuitry external to the used
1235 SoC, then define this variable and provide board
1236 specific code for the "hw_watchdog_reset" function.
1238 CONFIG_AT91_HW_WDT_TIMEOUT
1239 specify the timeout in seconds. default 2 seconds.
1242 CONFIG_VERSION_VARIABLE
1243 If this variable is defined, an environment variable
1244 named "ver" is created by U-Boot showing the U-Boot
1245 version as printed by the "version" command.
1246 Any change to this variable will be reverted at the
1251 When CONFIG_CMD_DATE is selected, the type of the RTC
1252 has to be selected, too. Define exactly one of the
1255 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx
1256 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC
1257 CONFIG_RTC_MC13XXX - use MC13783 or MC13892 RTC
1258 CONFIG_RTC_MC146818 - use MC146818 RTC
1259 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC
1260 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC
1261 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC
1262 CONFIG_RTC_DS1339 - use Maxim, Inc. DS1339 RTC
1263 CONFIG_RTC_DS164x - use Dallas DS164x RTC
1264 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC
1265 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC
1266 CONFIG_SYS_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337
1267 CONFIG_SYS_RV3029_TCR - enable trickle charger on
1270 Note that if the RTC uses I2C, then the I2C interface
1271 must also be configured. See I2C Support, below.
1274 CONFIG_PCA953X - use NXP's PCA953X series I2C GPIO
1276 The CONFIG_SYS_I2C_PCA953X_WIDTH option specifies a list of
1277 chip-ngpio pairs that tell the PCA953X driver the number of
1278 pins supported by a particular chip.
1280 Note that if the GPIO device uses I2C, then the I2C interface
1281 must also be configured. See I2C Support, below.
1284 When CONFIG_IO_TRACE is selected, U-Boot intercepts all I/O
1285 accesses and can checksum them or write a list of them out
1286 to memory. See the 'iotrace' command for details. This is
1287 useful for testing device drivers since it can confirm that
1288 the driver behaves the same way before and after a code
1289 change. Currently this is supported on sandbox and arm. To
1290 add support for your architecture, add '#include <iotrace.h>'
1291 to the bottom of arch/<arch>/include/asm/io.h and test.
1293 Example output from the 'iotrace stats' command is below.
1294 Note that if the trace buffer is exhausted, the checksum will
1295 still continue to operate.
1298 Start: 10000000 (buffer start address)
1299 Size: 00010000 (buffer size)
1300 Offset: 00000120 (current buffer offset)
1301 Output: 10000120 (start + offset)
1302 Count: 00000018 (number of trace records)
1303 CRC32: 9526fb66 (CRC32 of all trace records)
1305 - Timestamp Support:
1307 When CONFIG_TIMESTAMP is selected, the timestamp
1308 (date and time) of an image is printed by image
1309 commands like bootm or iminfo. This option is
1310 automatically enabled when you select CONFIG_CMD_DATE .
1312 - Partition Labels (disklabels) Supported:
1313 Zero or more of the following:
1314 CONFIG_MAC_PARTITION Apple's MacOS partition table.
1315 CONFIG_DOS_PARTITION MS Dos partition table, traditional on the
1316 Intel architecture, USB sticks, etc.
1317 CONFIG_ISO_PARTITION ISO partition table, used on CDROM etc.
1318 CONFIG_EFI_PARTITION GPT partition table, common when EFI is the
1319 bootloader. Note 2TB partition limit; see
1321 CONFIG_MTD_PARTITIONS Memory Technology Device partition table.
1323 If IDE or SCSI support is enabled (CONFIG_CMD_IDE or
1324 CONFIG_CMD_SCSI) you must configure support for at
1325 least one non-MTD partition type as well.
1328 CONFIG_IDE_RESET_ROUTINE - this is defined in several
1329 board configurations files but used nowhere!
1331 CONFIG_IDE_RESET - is this is defined, IDE Reset will
1332 be performed by calling the function
1333 ide_set_reset(int reset)
1334 which has to be defined in a board specific file
1339 Set this to enable ATAPI support.
1344 Set this to enable support for disks larger than 137GB
1345 Also look at CONFIG_SYS_64BIT_LBA.
1346 Whithout these , LBA48 support uses 32bit variables and will 'only'
1347 support disks up to 2.1TB.
1349 CONFIG_SYS_64BIT_LBA:
1350 When enabled, makes the IDE subsystem use 64bit sector addresses.
1354 At the moment only there is only support for the
1355 SYM53C8XX SCSI controller; define
1356 CONFIG_SCSI_SYM53C8XX to enable it.
1358 CONFIG_SYS_SCSI_MAX_LUN [8], CONFIG_SYS_SCSI_MAX_SCSI_ID [7] and
1359 CONFIG_SYS_SCSI_MAX_DEVICE [CONFIG_SYS_SCSI_MAX_SCSI_ID *
1360 CONFIG_SYS_SCSI_MAX_LUN] can be adjusted to define the
1361 maximum numbers of LUNs, SCSI ID's and target
1363 CONFIG_SYS_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz)
1365 The environment variable 'scsidevs' is set to the number of
1366 SCSI devices found during the last scan.
1368 - NETWORK Support (PCI):
1370 Support for Intel 8254x/8257x gigabit chips.
1373 Utility code for direct access to the SPI bus on Intel 8257x.
1374 This does not do anything useful unless you set at least one
1375 of CONFIG_CMD_E1000 or CONFIG_E1000_SPI_GENERIC.
1377 CONFIG_E1000_SPI_GENERIC
1378 Allow generic access to the SPI bus on the Intel 8257x, for
1379 example with the "sspi" command.
1382 Management command for E1000 devices. When used on devices
1383 with SPI support you can reprogram the EEPROM from U-Boot.
1385 CONFIG_E1000_FALLBACK_MAC
1386 default MAC for empty EEPROM after production.
1389 Support for Intel 82557/82559/82559ER chips.
1390 Optional CONFIG_EEPRO100_SROM_WRITE enables EEPROM
1391 write routine for first time initialisation.
1394 Support for Digital 2114x chips.
1395 Optional CONFIG_TULIP_SELECT_MEDIA for board specific
1396 modem chip initialisation (KS8761/QS6611).
1399 Support for National dp83815 chips.
1402 Support for National dp8382[01] gigabit chips.
1404 - NETWORK Support (other):
1406 CONFIG_DRIVER_AT91EMAC
1407 Support for AT91RM9200 EMAC.
1410 Define this to use reduced MII inteface
1412 CONFIG_DRIVER_AT91EMAC_QUIET
1413 If this defined, the driver is quiet.
1414 The driver doen't show link status messages.
1416 CONFIG_CALXEDA_XGMAC
1417 Support for the Calxeda XGMAC device
1420 Support for SMSC's LAN91C96 chips.
1422 CONFIG_LAN91C96_BASE
1423 Define this to hold the physical address
1424 of the LAN91C96's I/O space
1426 CONFIG_LAN91C96_USE_32_BIT
1427 Define this to enable 32 bit addressing
1430 Support for SMSC's LAN91C111 chip
1432 CONFIG_SMC91111_BASE
1433 Define this to hold the physical address
1434 of the device (I/O space)
1436 CONFIG_SMC_USE_32_BIT
1437 Define this if data bus is 32 bits
1439 CONFIG_SMC_USE_IOFUNCS
1440 Define this to use i/o functions instead of macros
1441 (some hardware wont work with macros)
1443 CONFIG_DRIVER_TI_EMAC
1444 Support for davinci emac
1446 CONFIG_SYS_DAVINCI_EMAC_PHY_COUNT
1447 Define this if you have more then 3 PHYs.
1450 Support for Faraday's FTGMAC100 Gigabit SoC Ethernet
1452 CONFIG_FTGMAC100_EGIGA
1453 Define this to use GE link update with gigabit PHY.
1454 Define this if FTGMAC100 is connected to gigabit PHY.
1455 If your system has 10/100 PHY only, it might not occur
1456 wrong behavior. Because PHY usually return timeout or
1457 useless data when polling gigabit status and gigabit
1458 control registers. This behavior won't affect the
1459 correctnessof 10/100 link speed update.
1462 Support for SMSC's LAN911x and LAN921x chips
1465 Define this to hold the physical address
1466 of the device (I/O space)
1468 CONFIG_SMC911X_32_BIT
1469 Define this if data bus is 32 bits
1471 CONFIG_SMC911X_16_BIT
1472 Define this if data bus is 16 bits. If your processor
1473 automatically converts one 32 bit word to two 16 bit
1474 words you may also try CONFIG_SMC911X_32_BIT.
1477 Support for Renesas on-chip Ethernet controller
1479 CONFIG_SH_ETHER_USE_PORT
1480 Define the number of ports to be used
1482 CONFIG_SH_ETHER_PHY_ADDR
1483 Define the ETH PHY's address
1485 CONFIG_SH_ETHER_CACHE_WRITEBACK
1486 If this option is set, the driver enables cache flush.
1490 Support for PWM modul on the imx6.
1494 Support TPM devices.
1497 Support for i2c bus TPM devices. Only one device
1498 per system is supported at this time.
1500 CONFIG_TPM_TIS_I2C_BUS_NUMBER
1501 Define the the i2c bus number for the TPM device
1503 CONFIG_TPM_TIS_I2C_SLAVE_ADDRESS
1504 Define the TPM's address on the i2c bus
1506 CONFIG_TPM_TIS_I2C_BURST_LIMITATION
1507 Define the burst count bytes upper limit
1509 CONFIG_TPM_ATMEL_TWI
1510 Support for Atmel TWI TPM device. Requires I2C support.
1513 Support for generic parallel port TPM devices. Only one device
1514 per system is supported at this time.
1516 CONFIG_TPM_TIS_BASE_ADDRESS
1517 Base address where the generic TPM device is mapped
1518 to. Contemporary x86 systems usually map it at
1522 Add tpm monitor functions.
1523 Requires CONFIG_TPM. If CONFIG_TPM_AUTH_SESSIONS is set, also
1524 provides monitor access to authorized functions.
1527 Define this to enable the TPM support library which provides
1528 functional interfaces to some TPM commands.
1529 Requires support for a TPM device.
1531 CONFIG_TPM_AUTH_SESSIONS
1532 Define this to enable authorized functions in the TPM library.
1533 Requires CONFIG_TPM and CONFIG_SHA1.
1536 At the moment only the UHCI host controller is
1537 supported (PIP405, MIP405, MPC5200); define
1538 CONFIG_USB_UHCI to enable it.
1539 define CONFIG_USB_KEYBOARD to enable the USB Keyboard
1540 and define CONFIG_USB_STORAGE to enable the USB
1543 Supported are USB Keyboards and USB Floppy drives
1545 MPC5200 USB requires additional defines:
1547 for 528 MHz Clock: 0x0001bbbb
1551 for differential drivers: 0x00001000
1552 for single ended drivers: 0x00005000
1553 for differential drivers on PSC3: 0x00000100
1554 for single ended drivers on PSC3: 0x00004100
1555 CONFIG_SYS_USB_EVENT_POLL
1556 May be defined to allow interrupt polling
1557 instead of using asynchronous interrupts
1559 CONFIG_USB_EHCI_TXFIFO_THRESH enables setting of the
1560 txfilltuning field in the EHCI controller on reset.
1562 CONFIG_USB_DWC2_REG_ADDR the physical CPU address of the DWC2
1563 HW module registers.
1566 Define the below if you wish to use the USB console.
1567 Once firmware is rebuilt from a serial console issue the
1568 command "setenv stdin usbtty; setenv stdout usbtty" and
1569 attach your USB cable. The Unix command "dmesg" should print
1570 it has found a new device. The environment variable usbtty
1571 can be set to gserial or cdc_acm to enable your device to
1572 appear to a USB host as a Linux gserial device or a
1573 Common Device Class Abstract Control Model serial device.
1574 If you select usbtty = gserial you should be able to enumerate
1576 # modprobe usbserial vendor=0xVendorID product=0xProductID
1577 else if using cdc_acm, simply setting the environment
1578 variable usbtty to be cdc_acm should suffice. The following
1579 might be defined in YourBoardName.h
1582 Define this to build a UDC device
1585 Define this to have a tty type of device available to
1586 talk to the UDC device
1589 Define this to enable the high speed support for usb
1590 device and usbtty. If this feature is enabled, a routine
1591 int is_usbd_high_speed(void)
1592 also needs to be defined by the driver to dynamically poll
1593 whether the enumeration has succeded at high speed or full
1596 CONFIG_SYS_CONSOLE_IS_IN_ENV
1597 Define this if you want stdin, stdout &/or stderr to
1601 CONFIG_SYS_USB_EXTC_CLK 0xBLAH
1602 Derive USB clock from external clock "blah"
1603 - CONFIG_SYS_USB_EXTC_CLK 0x02
1605 CONFIG_SYS_USB_BRG_CLK 0xBLAH
1606 Derive USB clock from brgclk
1607 - CONFIG_SYS_USB_BRG_CLK 0x04
1609 If you have a USB-IF assigned VendorID then you may wish to
1610 define your own vendor specific values either in BoardName.h
1611 or directly in usbd_vendor_info.h. If you don't define
1612 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME,
1613 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot
1614 should pretend to be a Linux device to it's target host.
1616 CONFIG_USBD_MANUFACTURER
1617 Define this string as the name of your company for
1618 - CONFIG_USBD_MANUFACTURER "my company"
1620 CONFIG_USBD_PRODUCT_NAME
1621 Define this string as the name of your product
1622 - CONFIG_USBD_PRODUCT_NAME "acme usb device"
1624 CONFIG_USBD_VENDORID
1625 Define this as your assigned Vendor ID from the USB
1626 Implementors Forum. This *must* be a genuine Vendor ID
1627 to avoid polluting the USB namespace.
1628 - CONFIG_USBD_VENDORID 0xFFFF
1630 CONFIG_USBD_PRODUCTID
1631 Define this as the unique Product ID
1633 - CONFIG_USBD_PRODUCTID 0xFFFF
1635 - ULPI Layer Support:
1636 The ULPI (UTMI Low Pin (count) Interface) PHYs are supported via
1637 the generic ULPI layer. The generic layer accesses the ULPI PHY
1638 via the platform viewport, so you need both the genric layer and
1639 the viewport enabled. Currently only Chipidea/ARC based
1640 viewport is supported.
1641 To enable the ULPI layer support, define CONFIG_USB_ULPI and
1642 CONFIG_USB_ULPI_VIEWPORT in your board configuration file.
1643 If your ULPI phy needs a different reference clock than the
1644 standard 24 MHz then you have to define CONFIG_ULPI_REF_CLK to
1645 the appropriate value in Hz.
1648 The MMC controller on the Intel PXA is supported. To
1649 enable this define CONFIG_MMC. The MMC can be
1650 accessed from the boot prompt by mapping the device
1651 to physical memory similar to flash. Command line is
1652 enabled with CONFIG_CMD_MMC. The MMC driver also works with
1653 the FAT fs. This is enabled with CONFIG_CMD_FAT.
1656 Support for Renesas on-chip MMCIF controller
1658 CONFIG_SH_MMCIF_ADDR
1659 Define the base address of MMCIF registers
1662 Define the clock frequency for MMCIF
1665 Enable the generic MMC driver
1667 CONFIG_SUPPORT_EMMC_BOOT
1668 Enable some additional features of the eMMC boot partitions.
1670 CONFIG_SUPPORT_EMMC_RPMB
1671 Enable the commands for reading, writing and programming the
1672 key for the Replay Protection Memory Block partition in eMMC.
1674 - USB Device Firmware Update (DFU) class support:
1675 CONFIG_USB_FUNCTION_DFU
1676 This enables the USB portion of the DFU USB class
1679 This enables the command "dfu" which is used to have
1680 U-Boot create a DFU class device via USB. This command
1681 requires that the "dfu_alt_info" environment variable be
1682 set and define the alt settings to expose to the host.
1685 This enables support for exposing (e)MMC devices via DFU.
1688 This enables support for exposing NAND devices via DFU.
1691 This enables support for exposing RAM via DFU.
1692 Note: DFU spec refer to non-volatile memory usage, but
1693 allow usages beyond the scope of spec - here RAM usage,
1694 one that would help mostly the developer.
1696 CONFIG_SYS_DFU_DATA_BUF_SIZE
1697 Dfu transfer uses a buffer before writing data to the
1698 raw storage device. Make the size (in bytes) of this buffer
1699 configurable. The size of this buffer is also configurable
1700 through the "dfu_bufsiz" environment variable.
1702 CONFIG_SYS_DFU_MAX_FILE_SIZE
1703 When updating files rather than the raw storage device,
1704 we use a static buffer to copy the file into and then write
1705 the buffer once we've been given the whole file. Define
1706 this to the maximum filesize (in bytes) for the buffer.
1707 Default is 4 MiB if undefined.
1709 DFU_DEFAULT_POLL_TIMEOUT
1710 Poll timeout [ms], is the timeout a device can send to the
1711 host. The host must wait for this timeout before sending
1712 a subsequent DFU_GET_STATUS request to the device.
1714 DFU_MANIFEST_POLL_TIMEOUT
1715 Poll timeout [ms], which the device sends to the host when
1716 entering dfuMANIFEST state. Host waits this timeout, before
1717 sending again an USB request to the device.
1719 - USB Device Android Fastboot support:
1720 CONFIG_USB_FUNCTION_FASTBOOT
1721 This enables the USB part of the fastboot gadget
1724 This enables the command "fastboot" which enables the Android
1725 fastboot mode for the platform's USB device. Fastboot is a USB
1726 protocol for downloading images, flashing and device control
1727 used on Android devices.
1728 See doc/README.android-fastboot for more information.
1730 CONFIG_ANDROID_BOOT_IMAGE
1731 This enables support for booting images which use the Android
1732 image format header.
1734 CONFIG_FASTBOOT_BUF_ADDR
1735 The fastboot protocol requires a large memory buffer for
1736 downloads. Define this to the starting RAM address to use for
1739 CONFIG_FASTBOOT_BUF_SIZE
1740 The fastboot protocol requires a large memory buffer for
1741 downloads. This buffer should be as large as possible for a
1742 platform. Define this to the size available RAM for fastboot.
1744 CONFIG_FASTBOOT_FLASH
1745 The fastboot protocol includes a "flash" command for writing
1746 the downloaded image to a non-volatile storage device. Define
1747 this to enable the "fastboot flash" command.
1749 CONFIG_FASTBOOT_FLASH_MMC_DEV
1750 The fastboot "flash" command requires additional information
1751 regarding the non-volatile storage device. Define this to
1752 the eMMC device that fastboot should use to store the image.
1754 CONFIG_FASTBOOT_GPT_NAME
1755 The fastboot "flash" command supports writing the downloaded
1756 image to the Protective MBR and the Primary GUID Partition
1757 Table. (Additionally, this downloaded image is post-processed
1758 to generate and write the Backup GUID Partition Table.)
1759 This occurs when the specified "partition name" on the
1760 "fastboot flash" command line matches this value.
1761 Default is GPT_ENTRY_NAME (currently "gpt") if undefined.
1763 - Journaling Flash filesystem support:
1764 CONFIG_JFFS2_NAND, CONFIG_JFFS2_NAND_OFF, CONFIG_JFFS2_NAND_SIZE,
1765 CONFIG_JFFS2_NAND_DEV
1766 Define these for a default partition on a NAND device
1768 CONFIG_SYS_JFFS2_FIRST_SECTOR,
1769 CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS
1770 Define these for a default partition on a NOR device
1772 CONFIG_SYS_JFFS_CUSTOM_PART
1773 Define this to create an own partition. You have to provide a
1774 function struct part_info* jffs2_part_info(int part_num)
1776 If you define only one JFFS2 partition you may also want to
1777 #define CONFIG_SYS_JFFS_SINGLE_PART 1
1778 to disable the command chpart. This is the default when you
1779 have not defined a custom partition
1781 - FAT(File Allocation Table) filesystem write function support:
1784 Define this to enable support for saving memory data as a
1785 file in FAT formatted partition.
1787 This will also enable the command "fatwrite" enabling the
1788 user to write files to FAT.
1790 CBFS (Coreboot Filesystem) support
1793 Define this to enable support for reading from a Coreboot
1794 filesystem. Available commands are cbfsinit, cbfsinfo, cbfsls
1797 - FAT(File Allocation Table) filesystem cluster size:
1798 CONFIG_FS_FAT_MAX_CLUSTSIZE
1800 Define the max cluster size for fat operations else
1801 a default value of 65536 will be defined.
1806 Define this to enable standard (PC-Style) keyboard
1810 Standard PC keyboard driver with US (is default) and
1811 GERMAN key layout (switch via environment 'keymap=de') support.
1812 Export function i8042_kbd_init, i8042_tstc and i8042_getc
1813 for cfb_console. Supports cursor blinking.
1816 Enables a Chrome OS keyboard using the CROS_EC interface.
1817 This uses CROS_EC to communicate with a second microcontroller
1818 which provides key scans on request.
1823 Define this to enable video support (for output to
1826 CONFIG_VIDEO_CT69000
1828 Enable Chips & Technologies 69000 Video chip
1830 CONFIG_VIDEO_SMI_LYNXEM
1831 Enable Silicon Motion SMI 712/710/810 Video chip. The
1832 video output is selected via environment 'videoout'
1833 (1 = LCD and 2 = CRT). If videoout is undefined, CRT is
1836 For the CT69000 and SMI_LYNXEM drivers, videomode is
1837 selected via environment 'videomode'. Two different ways
1839 - "videomode=num" 'num' is a standard LiLo mode numbers.
1840 Following standard modes are supported (* is default):
1842 Colors 640x480 800x600 1024x768 1152x864 1280x1024
1843 -------------+---------------------------------------------
1844 8 bits | 0x301* 0x303 0x305 0x161 0x307
1845 15 bits | 0x310 0x313 0x316 0x162 0x319
1846 16 bits | 0x311 0x314 0x317 0x163 0x31A
1847 24 bits | 0x312 0x315 0x318 ? 0x31B
1848 -------------+---------------------------------------------
1849 (i.e. setenv videomode 317; saveenv; reset;)
1851 - "videomode=bootargs" all the video parameters are parsed
1852 from the bootargs. (See drivers/video/videomodes.c)
1855 CONFIG_VIDEO_SED13806
1856 Enable Epson SED13806 driver. This driver supports 8bpp
1857 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP
1858 or CONFIG_VIDEO_SED13806_16BPP
1861 Enable the Freescale DIU video driver. Reference boards for
1862 SOCs that have a DIU should define this macro to enable DIU
1863 support, and should also define these other macros:
1869 CONFIG_VIDEO_SW_CURSOR
1870 CONFIG_VGA_AS_SINGLE_DEVICE
1872 CONFIG_VIDEO_BMP_LOGO
1874 The DIU driver will look for the 'video-mode' environment
1875 variable, and if defined, enable the DIU as a console during
1876 boot. See the documentation file README.video for a
1877 description of this variable.
1883 Define this to enable a custom keyboard support.
1884 This simply calls drv_keyboard_init() which must be
1885 defined in your board-specific files.
1886 The only board using this so far is RBC823.
1888 - LCD Support: CONFIG_LCD
1890 Define this to enable LCD support (for output to LCD
1891 display); also select one of the supported displays
1892 by defining one of these:
1896 HITACHI TX09D70VM1CCA, 3.5", 240x320.
1898 CONFIG_NEC_NL6448AC33:
1900 NEC NL6448AC33-18. Active, color, single scan.
1902 CONFIG_NEC_NL6448BC20
1904 NEC NL6448BC20-08. 6.5", 640x480.
1905 Active, color, single scan.
1907 CONFIG_NEC_NL6448BC33_54
1909 NEC NL6448BC33-54. 10.4", 640x480.
1910 Active, color, single scan.
1914 Sharp 320x240. Active, color, single scan.
1915 It isn't 16x9, and I am not sure what it is.
1917 CONFIG_SHARP_LQ64D341
1919 Sharp LQ64D341 display, 640x480.
1920 Active, color, single scan.
1924 HLD1045 display, 640x480.
1925 Active, color, single scan.
1929 Optrex CBL50840-2 NF-FW 99 22 M5
1931 Hitachi LMG6912RPFC-00T
1935 320x240. Black & white.
1937 Normally display is black on white background; define
1938 CONFIG_SYS_WHITE_ON_BLACK to get it inverted.
1940 CONFIG_LCD_ALIGNMENT
1942 Normally the LCD is page-aligned (typically 4KB). If this is
1943 defined then the LCD will be aligned to this value instead.
1944 For ARM it is sometimes useful to use MMU_SECTION_SIZE
1945 here, since it is cheaper to change data cache settings on
1946 a per-section basis.
1948 CONFIG_CONSOLE_SCROLL_LINES
1950 When the console need to be scrolled, this is the number of
1951 lines to scroll by. It defaults to 1. Increasing this makes
1952 the console jump but can help speed up operation when scrolling
1957 Sometimes, for example if the display is mounted in portrait
1958 mode or even if it's mounted landscape but rotated by 180degree,
1959 we need to rotate our content of the display relative to the
1960 framebuffer, so that user can read the messages which are
1962 Once CONFIG_LCD_ROTATION is defined, the lcd_console will be
1963 initialized with a given rotation from "vl_rot" out of
1964 "vidinfo_t" which is provided by the board specific code.
1965 The value for vl_rot is coded as following (matching to
1966 fbcon=rotate:<n> linux-kernel commandline):
1967 0 = no rotation respectively 0 degree
1968 1 = 90 degree rotation
1969 2 = 180 degree rotation
1970 3 = 270 degree rotation
1972 If CONFIG_LCD_ROTATION is not defined, the console will be
1973 initialized with 0degree rotation.
1977 Support drawing of RLE8-compressed bitmaps on the LCD.
1981 Enables an 'i2c edid' command which can read EDID
1982 information over I2C from an attached LCD display.
1984 - Splash Screen Support: CONFIG_SPLASH_SCREEN
1986 If this option is set, the environment is checked for
1987 a variable "splashimage". If found, the usual display
1988 of logo, copyright and system information on the LCD
1989 is suppressed and the BMP image at the address
1990 specified in "splashimage" is loaded instead. The
1991 console is redirected to the "nulldev", too. This
1992 allows for a "silent" boot where a splash screen is
1993 loaded very quickly after power-on.
1995 CONFIG_SPLASHIMAGE_GUARD
1997 If this option is set, then U-Boot will prevent the environment
1998 variable "splashimage" from being set to a problematic address
1999 (see README.displaying-bmps).
2000 This option is useful for targets where, due to alignment
2001 restrictions, an improperly aligned BMP image will cause a data
2002 abort. If you think you will not have problems with unaligned
2003 accesses (for example because your toolchain prevents them)
2004 there is no need to set this option.
2006 CONFIG_SPLASH_SCREEN_ALIGN
2008 If this option is set the splash image can be freely positioned
2009 on the screen. Environment variable "splashpos" specifies the
2010 position as "x,y". If a positive number is given it is used as
2011 number of pixel from left/top. If a negative number is given it
2012 is used as number of pixel from right/bottom. You can also
2013 specify 'm' for centering the image.
2016 setenv splashpos m,m
2017 => image at center of screen
2019 setenv splashpos 30,20
2020 => image at x = 30 and y = 20
2022 setenv splashpos -10,m
2023 => vertically centered image
2024 at x = dspWidth - bmpWidth - 9
2026 - Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP
2028 If this option is set, additionally to standard BMP
2029 images, gzipped BMP images can be displayed via the
2030 splashscreen support or the bmp command.
2032 - Run length encoded BMP image (RLE8) support: CONFIG_VIDEO_BMP_RLE8
2034 If this option is set, 8-bit RLE compressed BMP images
2035 can be displayed via the splashscreen support or the
2038 - Do compressing for memory range:
2041 If this option is set, it would use zlib deflate method
2042 to compress the specified memory at its best effort.
2044 - Compression support:
2047 Enabled by default to support gzip compressed images.
2051 If this option is set, support for bzip2 compressed
2052 images is included. If not, only uncompressed and gzip
2053 compressed images are supported.
2055 NOTE: the bzip2 algorithm requires a lot of RAM, so
2056 the malloc area (as defined by CONFIG_SYS_MALLOC_LEN) should
2061 If this option is set, support for lzma compressed
2064 Note: The LZMA algorithm adds between 2 and 4KB of code and it
2065 requires an amount of dynamic memory that is given by the
2068 (1846 + 768 << (lc + lp)) * sizeof(uint16)
2070 Where lc and lp stand for, respectively, Literal context bits
2071 and Literal pos bits.
2073 This value is upper-bounded by 14MB in the worst case. Anyway,
2074 for a ~4MB large kernel image, we have lc=3 and lp=0 for a
2075 total amount of (1846 + 768 << (3 + 0)) * 2 = ~41KB... that is
2076 a very small buffer.
2078 Use the lzmainfo tool to determinate the lc and lp values and
2079 then calculate the amount of needed dynamic memory (ensuring
2080 the appropriate CONFIG_SYS_MALLOC_LEN value).
2084 If this option is set, support for LZO compressed images
2090 The address of PHY on MII bus.
2092 CONFIG_PHY_CLOCK_FREQ (ppc4xx)
2094 The clock frequency of the MII bus
2098 If this option is set, support for speed/duplex
2099 detection of gigabit PHY is included.
2101 CONFIG_PHY_RESET_DELAY
2103 Some PHY like Intel LXT971A need extra delay after
2104 reset before any MII register access is possible.
2105 For such PHY, set this option to the usec delay
2106 required. (minimum 300usec for LXT971A)
2108 CONFIG_PHY_CMD_DELAY (ppc4xx)
2110 Some PHY like Intel LXT971A need extra delay after
2111 command issued before MII status register can be read
2116 Define a default value for the IP address to use for
2117 the default Ethernet interface, in case this is not
2118 determined through e.g. bootp.
2119 (Environment variable "ipaddr")
2121 - Server IP address:
2124 Defines a default value for the IP address of a TFTP
2125 server to contact when using the "tftboot" command.
2126 (Environment variable "serverip")
2128 CONFIG_KEEP_SERVERADDR
2130 Keeps the server's MAC address, in the env 'serveraddr'
2131 for passing to bootargs (like Linux's netconsole option)
2133 - Gateway IP address:
2136 Defines a default value for the IP address of the
2137 default router where packets to other networks are
2139 (Environment variable "gatewayip")
2144 Defines a default value for the subnet mask (or
2145 routing prefix) which is used to determine if an IP
2146 address belongs to the local subnet or needs to be
2147 forwarded through a router.
2148 (Environment variable "netmask")
2150 - Multicast TFTP Mode:
2153 Defines whether you want to support multicast TFTP as per
2154 rfc-2090; for example to work with atftp. Lets lots of targets
2155 tftp down the same boot image concurrently. Note: the Ethernet
2156 driver in use must provide a function: mcast() to join/leave a
2159 - BOOTP Recovery Mode:
2160 CONFIG_BOOTP_RANDOM_DELAY
2162 If you have many targets in a network that try to
2163 boot using BOOTP, you may want to avoid that all
2164 systems send out BOOTP requests at precisely the same
2165 moment (which would happen for instance at recovery
2166 from a power failure, when all systems will try to
2167 boot, thus flooding the BOOTP server. Defining
2168 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
2169 inserted before sending out BOOTP requests. The
2170 following delays are inserted then:
2172 1st BOOTP request: delay 0 ... 1 sec
2173 2nd BOOTP request: delay 0 ... 2 sec
2174 3rd BOOTP request: delay 0 ... 4 sec
2176 BOOTP requests: delay 0 ... 8 sec
2178 CONFIG_BOOTP_ID_CACHE_SIZE
2180 BOOTP packets are uniquely identified using a 32-bit ID. The
2181 server will copy the ID from client requests to responses and
2182 U-Boot will use this to determine if it is the destination of
2183 an incoming response. Some servers will check that addresses
2184 aren't in use before handing them out (usually using an ARP
2185 ping) and therefore take up to a few hundred milliseconds to
2186 respond. Network congestion may also influence the time it
2187 takes for a response to make it back to the client. If that
2188 time is too long, U-Boot will retransmit requests. In order
2189 to allow earlier responses to still be accepted after these
2190 retransmissions, U-Boot's BOOTP client keeps a small cache of
2191 IDs. The CONFIG_BOOTP_ID_CACHE_SIZE controls the size of this
2192 cache. The default is to keep IDs for up to four outstanding
2193 requests. Increasing this will allow U-Boot to accept offers
2194 from a BOOTP client in networks with unusually high latency.
2196 - DHCP Advanced Options:
2197 You can fine tune the DHCP functionality by defining
2198 CONFIG_BOOTP_* symbols:
2200 CONFIG_BOOTP_SUBNETMASK
2201 CONFIG_BOOTP_GATEWAY
2202 CONFIG_BOOTP_HOSTNAME
2203 CONFIG_BOOTP_NISDOMAIN
2204 CONFIG_BOOTP_BOOTPATH
2205 CONFIG_BOOTP_BOOTFILESIZE
2208 CONFIG_BOOTP_SEND_HOSTNAME
2209 CONFIG_BOOTP_NTPSERVER
2210 CONFIG_BOOTP_TIMEOFFSET
2211 CONFIG_BOOTP_VENDOREX
2212 CONFIG_BOOTP_MAY_FAIL
2214 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip
2215 environment variable, not the BOOTP server.
2217 CONFIG_BOOTP_MAY_FAIL - If the DHCP server is not found
2218 after the configured retry count, the call will fail
2219 instead of starting over. This can be used to fail over
2220 to Link-local IP address configuration if the DHCP server
2223 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS
2224 serverip from a DHCP server, it is possible that more
2225 than one DNS serverip is offered to the client.
2226 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS
2227 serverip will be stored in the additional environment
2228 variable "dnsip2". The first DNS serverip is always
2229 stored in the variable "dnsip", when CONFIG_BOOTP_DNS
2232 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable
2233 to do a dynamic update of a DNS server. To do this, they
2234 need the hostname of the DHCP requester.
2235 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content
2236 of the "hostname" environment variable is passed as
2237 option 12 to the DHCP server.
2239 CONFIG_BOOTP_DHCP_REQUEST_DELAY
2241 A 32bit value in microseconds for a delay between
2242 receiving a "DHCP Offer" and sending the "DHCP Request".
2243 This fixes a problem with certain DHCP servers that don't
2244 respond 100% of the time to a "DHCP request". E.g. On an
2245 AT91RM9200 processor running at 180MHz, this delay needed
2246 to be *at least* 15,000 usec before a Windows Server 2003
2247 DHCP server would reply 100% of the time. I recommend at
2248 least 50,000 usec to be safe. The alternative is to hope
2249 that one of the retries will be successful but note that
2250 the DHCP timeout and retry process takes a longer than
2253 - Link-local IP address negotiation:
2254 Negotiate with other link-local clients on the local network
2255 for an address that doesn't require explicit configuration.
2256 This is especially useful if a DHCP server cannot be guaranteed
2257 to exist in all environments that the device must operate.
2259 See doc/README.link-local for more information.
2262 CONFIG_CDP_DEVICE_ID
2264 The device id used in CDP trigger frames.
2266 CONFIG_CDP_DEVICE_ID_PREFIX
2268 A two character string which is prefixed to the MAC address
2273 A printf format string which contains the ascii name of
2274 the port. Normally is set to "eth%d" which sets
2275 eth0 for the first Ethernet, eth1 for the second etc.
2277 CONFIG_CDP_CAPABILITIES
2279 A 32bit integer which indicates the device capabilities;
2280 0x00000010 for a normal host which does not forwards.
2284 An ascii string containing the version of the software.
2288 An ascii string containing the name of the platform.
2292 A 32bit integer sent on the trigger.
2294 CONFIG_CDP_POWER_CONSUMPTION
2296 A 16bit integer containing the power consumption of the
2297 device in .1 of milliwatts.
2299 CONFIG_CDP_APPLIANCE_VLAN_TYPE
2301 A byte containing the id of the VLAN.
2303 - Status LED: CONFIG_STATUS_LED
2305 Several configurations allow to display the current
2306 status using a LED. For instance, the LED will blink
2307 fast while running U-Boot code, stop blinking as
2308 soon as a reply to a BOOTP request was received, and
2309 start blinking slow once the Linux kernel is running
2310 (supported by a status LED driver in the Linux
2311 kernel). Defining CONFIG_STATUS_LED enables this
2317 The status LED can be connected to a GPIO pin.
2318 In such cases, the gpio_led driver can be used as a
2319 status LED backend implementation. Define CONFIG_GPIO_LED
2320 to include the gpio_led driver in the U-Boot binary.
2322 CONFIG_GPIO_LED_INVERTED_TABLE
2323 Some GPIO connected LEDs may have inverted polarity in which
2324 case the GPIO high value corresponds to LED off state and
2325 GPIO low value corresponds to LED on state.
2326 In such cases CONFIG_GPIO_LED_INVERTED_TABLE may be defined
2327 with a list of GPIO LEDs that have inverted polarity.
2329 - CAN Support: CONFIG_CAN_DRIVER
2331 Defining CONFIG_CAN_DRIVER enables CAN driver support
2332 on those systems that support this (optional)
2333 feature, like the TQM8xxL modules.
2335 - I2C Support: CONFIG_SYS_I2C
2337 This enable the NEW i2c subsystem, and will allow you to use
2338 i2c commands at the u-boot command line (as long as you set
2339 CONFIG_CMD_I2C in CONFIG_COMMANDS) and communicate with i2c
2340 based realtime clock chips or other i2c devices. See
2341 common/cmd_i2c.c for a description of the command line
2344 ported i2c driver to the new framework:
2345 - drivers/i2c/soft_i2c.c:
2346 - activate first bus with CONFIG_SYS_I2C_SOFT define
2347 CONFIG_SYS_I2C_SOFT_SPEED and CONFIG_SYS_I2C_SOFT_SLAVE
2348 for defining speed and slave address
2349 - activate second bus with I2C_SOFT_DECLARATIONS2 define
2350 CONFIG_SYS_I2C_SOFT_SPEED_2 and CONFIG_SYS_I2C_SOFT_SLAVE_2
2351 for defining speed and slave address
2352 - activate third bus with I2C_SOFT_DECLARATIONS3 define
2353 CONFIG_SYS_I2C_SOFT_SPEED_3 and CONFIG_SYS_I2C_SOFT_SLAVE_3
2354 for defining speed and slave address
2355 - activate fourth bus with I2C_SOFT_DECLARATIONS4 define
2356 CONFIG_SYS_I2C_SOFT_SPEED_4 and CONFIG_SYS_I2C_SOFT_SLAVE_4
2357 for defining speed and slave address
2359 - drivers/i2c/fsl_i2c.c:
2360 - activate i2c driver with CONFIG_SYS_I2C_FSL
2361 define CONFIG_SYS_FSL_I2C_OFFSET for setting the register
2362 offset CONFIG_SYS_FSL_I2C_SPEED for the i2c speed and
2363 CONFIG_SYS_FSL_I2C_SLAVE for the slave addr of the first
2365 - If your board supports a second fsl i2c bus, define
2366 CONFIG_SYS_FSL_I2C2_OFFSET for the register offset
2367 CONFIG_SYS_FSL_I2C2_SPEED for the speed and
2368 CONFIG_SYS_FSL_I2C2_SLAVE for the slave address of the
2371 - drivers/i2c/tegra_i2c.c:
2372 - activate this driver with CONFIG_SYS_I2C_TEGRA
2373 - This driver adds 4 i2c buses with a fix speed from
2374 100000 and the slave addr 0!
2376 - drivers/i2c/ppc4xx_i2c.c
2377 - activate this driver with CONFIG_SYS_I2C_PPC4XX
2378 - CONFIG_SYS_I2C_PPC4XX_CH0 activate hardware channel 0
2379 - CONFIG_SYS_I2C_PPC4XX_CH1 activate hardware channel 1
2381 - drivers/i2c/i2c_mxc.c
2382 - activate this driver with CONFIG_SYS_I2C_MXC
2383 - define speed for bus 1 with CONFIG_SYS_MXC_I2C1_SPEED
2384 - define slave for bus 1 with CONFIG_SYS_MXC_I2C1_SLAVE
2385 - define speed for bus 2 with CONFIG_SYS_MXC_I2C2_SPEED
2386 - define slave for bus 2 with CONFIG_SYS_MXC_I2C2_SLAVE
2387 - define speed for bus 3 with CONFIG_SYS_MXC_I2C3_SPEED
2388 - define slave for bus 3 with CONFIG_SYS_MXC_I2C3_SLAVE
2389 If those defines are not set, default value is 100000
2390 for speed, and 0 for slave.
2391 - enable bus 3 with CONFIG_SYS_I2C_MXC_I2C3
2392 - enable bus 4 with CONFIG_SYS_I2C_MXC_I2C4
2394 - drivers/i2c/rcar_i2c.c:
2395 - activate this driver with CONFIG_SYS_I2C_RCAR
2396 - This driver adds 4 i2c buses
2398 - CONFIG_SYS_RCAR_I2C0_BASE for setting the register channel 0
2399 - CONFIG_SYS_RCAR_I2C0_SPEED for for the speed channel 0
2400 - CONFIG_SYS_RCAR_I2C1_BASE for setting the register channel 1
2401 - CONFIG_SYS_RCAR_I2C1_SPEED for for the speed channel 1
2402 - CONFIG_SYS_RCAR_I2C2_BASE for setting the register channel 2
2403 - CONFIG_SYS_RCAR_I2C2_SPEED for for the speed channel 2
2404 - CONFIG_SYS_RCAR_I2C3_BASE for setting the register channel 3
2405 - CONFIG_SYS_RCAR_I2C3_SPEED for for the speed channel 3
2406 - CONFIF_SYS_RCAR_I2C_NUM_CONTROLLERS for number of i2c buses
2408 - drivers/i2c/sh_i2c.c:
2409 - activate this driver with CONFIG_SYS_I2C_SH
2410 - This driver adds from 2 to 5 i2c buses
2412 - CONFIG_SYS_I2C_SH_BASE0 for setting the register channel 0
2413 - CONFIG_SYS_I2C_SH_SPEED0 for for the speed channel 0
2414 - CONFIG_SYS_I2C_SH_BASE1 for setting the register channel 1
2415 - CONFIG_SYS_I2C_SH_SPEED1 for for the speed channel 1
2416 - CONFIG_SYS_I2C_SH_BASE2 for setting the register channel 2
2417 - CONFIG_SYS_I2C_SH_SPEED2 for for the speed channel 2
2418 - CONFIG_SYS_I2C_SH_BASE3 for setting the register channel 3
2419 - CONFIG_SYS_I2C_SH_SPEED3 for for the speed channel 3
2420 - CONFIG_SYS_I2C_SH_BASE4 for setting the register channel 4
2421 - CONFIG_SYS_I2C_SH_SPEED4 for for the speed channel 4
2422 - CONFIG_SYS_I2C_SH_BASE5 for setting the register channel 5
2423 - CONFIG_SYS_I2C_SH_SPEED5 for for the speed channel 5
2424 - CONFIG_SYS_I2C_SH_NUM_CONTROLLERS for number of i2c buses
2426 - drivers/i2c/omap24xx_i2c.c
2427 - activate this driver with CONFIG_SYS_I2C_OMAP24XX
2428 - CONFIG_SYS_OMAP24_I2C_SPEED speed channel 0
2429 - CONFIG_SYS_OMAP24_I2C_SLAVE slave addr channel 0
2430 - CONFIG_SYS_OMAP24_I2C_SPEED1 speed channel 1
2431 - CONFIG_SYS_OMAP24_I2C_SLAVE1 slave addr channel 1
2432 - CONFIG_SYS_OMAP24_I2C_SPEED2 speed channel 2
2433 - CONFIG_SYS_OMAP24_I2C_SLAVE2 slave addr channel 2
2434 - CONFIG_SYS_OMAP24_I2C_SPEED3 speed channel 3
2435 - CONFIG_SYS_OMAP24_I2C_SLAVE3 slave addr channel 3
2436 - CONFIG_SYS_OMAP24_I2C_SPEED4 speed channel 4
2437 - CONFIG_SYS_OMAP24_I2C_SLAVE4 slave addr channel 4
2439 - drivers/i2c/zynq_i2c.c
2440 - activate this driver with CONFIG_SYS_I2C_ZYNQ
2441 - set CONFIG_SYS_I2C_ZYNQ_SPEED for speed setting
2442 - set CONFIG_SYS_I2C_ZYNQ_SLAVE for slave addr
2444 - drivers/i2c/s3c24x0_i2c.c:
2445 - activate this driver with CONFIG_SYS_I2C_S3C24X0
2446 - This driver adds i2c buses (11 for Exynos5250, Exynos5420
2447 9 i2c buses for Exynos4 and 1 for S3C24X0 SoCs from Samsung)
2448 with a fix speed from 100000 and the slave addr 0!
2450 - drivers/i2c/ihs_i2c.c
2451 - activate this driver with CONFIG_SYS_I2C_IHS
2452 - CONFIG_SYS_I2C_IHS_CH0 activate hardware channel 0
2453 - CONFIG_SYS_I2C_IHS_SPEED_0 speed channel 0
2454 - CONFIG_SYS_I2C_IHS_SLAVE_0 slave addr channel 0
2455 - CONFIG_SYS_I2C_IHS_CH1 activate hardware channel 1
2456 - CONFIG_SYS_I2C_IHS_SPEED_1 speed channel 1
2457 - CONFIG_SYS_I2C_IHS_SLAVE_1 slave addr channel 1
2458 - CONFIG_SYS_I2C_IHS_CH2 activate hardware channel 2
2459 - CONFIG_SYS_I2C_IHS_SPEED_2 speed channel 2
2460 - CONFIG_SYS_I2C_IHS_SLAVE_2 slave addr channel 2
2461 - CONFIG_SYS_I2C_IHS_CH3 activate hardware channel 3
2462 - CONFIG_SYS_I2C_IHS_SPEED_3 speed channel 3
2463 - CONFIG_SYS_I2C_IHS_SLAVE_3 slave addr channel 3
2467 CONFIG_SYS_NUM_I2C_BUSES
2468 Hold the number of i2c buses you want to use. If you
2469 don't use/have i2c muxes on your i2c bus, this
2470 is equal to CONFIG_SYS_NUM_I2C_ADAPTERS, and you can
2473 CONFIG_SYS_I2C_DIRECT_BUS
2474 define this, if you don't use i2c muxes on your hardware.
2475 if CONFIG_SYS_I2C_MAX_HOPS is not defined or == 0 you can
2478 CONFIG_SYS_I2C_MAX_HOPS
2479 define how many muxes are maximal consecutively connected
2480 on one i2c bus. If you not use i2c muxes, omit this
2483 CONFIG_SYS_I2C_BUSES
2484 hold a list of buses you want to use, only used if
2485 CONFIG_SYS_I2C_DIRECT_BUS is not defined, for example
2486 a board with CONFIG_SYS_I2C_MAX_HOPS = 1 and
2487 CONFIG_SYS_NUM_I2C_BUSES = 9:
2489 CONFIG_SYS_I2C_BUSES {{0, {I2C_NULL_HOP}}, \
2490 {0, {{I2C_MUX_PCA9547, 0x70, 1}}}, \
2491 {0, {{I2C_MUX_PCA9547, 0x70, 2}}}, \
2492 {0, {{I2C_MUX_PCA9547, 0x70, 3}}}, \
2493 {0, {{I2C_MUX_PCA9547, 0x70, 4}}}, \
2494 {0, {{I2C_MUX_PCA9547, 0x70, 5}}}, \
2495 {1, {I2C_NULL_HOP}}, \
2496 {1, {{I2C_MUX_PCA9544, 0x72, 1}}}, \
2497 {1, {{I2C_MUX_PCA9544, 0x72, 2}}}, \
2501 bus 0 on adapter 0 without a mux
2502 bus 1 on adapter 0 with a PCA9547 on address 0x70 port 1
2503 bus 2 on adapter 0 with a PCA9547 on address 0x70 port 2
2504 bus 3 on adapter 0 with a PCA9547 on address 0x70 port 3
2505 bus 4 on adapter 0 with a PCA9547 on address 0x70 port 4
2506 bus 5 on adapter 0 with a PCA9547 on address 0x70 port 5
2507 bus 6 on adapter 1 without a mux
2508 bus 7 on adapter 1 with a PCA9544 on address 0x72 port 1
2509 bus 8 on adapter 1 with a PCA9544 on address 0x72 port 2
2511 If you do not have i2c muxes on your board, omit this define.
2513 - Legacy I2C Support: CONFIG_HARD_I2C
2515 NOTE: It is intended to move drivers to CONFIG_SYS_I2C which
2516 provides the following compelling advantages:
2518 - more than one i2c adapter is usable
2519 - approved multibus support
2520 - better i2c mux support
2522 ** Please consider updating your I2C driver now. **
2524 These enable legacy I2C serial bus commands. Defining
2525 CONFIG_HARD_I2C will include the appropriate I2C driver
2526 for the selected CPU.
2528 This will allow you to use i2c commands at the u-boot
2529 command line (as long as you set CONFIG_CMD_I2C in
2530 CONFIG_COMMANDS) and communicate with i2c based realtime
2531 clock chips. See common/cmd_i2c.c for a description of the
2532 command line interface.
2534 CONFIG_HARD_I2C selects a hardware I2C controller.
2536 There are several other quantities that must also be
2537 defined when you define CONFIG_HARD_I2C.
2539 In both cases you will need to define CONFIG_SYS_I2C_SPEED
2540 to be the frequency (in Hz) at which you wish your i2c bus
2541 to run and CONFIG_SYS_I2C_SLAVE to be the address of this node (ie
2542 the CPU's i2c node address).
2544 Now, the u-boot i2c code for the mpc8xx
2545 (arch/powerpc/cpu/mpc8xx/i2c.c) sets the CPU up as a master node
2546 and so its address should therefore be cleared to 0 (See,
2547 eg, MPC823e User's Manual p.16-473). So, set
2548 CONFIG_SYS_I2C_SLAVE to 0.
2550 CONFIG_SYS_I2C_INIT_MPC5XXX
2552 When a board is reset during an i2c bus transfer
2553 chips might think that the current transfer is still
2554 in progress. Reset the slave devices by sending start
2555 commands until the slave device responds.
2557 That's all that's required for CONFIG_HARD_I2C.
2559 If you use the software i2c interface (CONFIG_SYS_I2C_SOFT)
2560 then the following macros need to be defined (examples are
2561 from include/configs/lwmon.h):
2565 (Optional). Any commands necessary to enable the I2C
2566 controller or configure ports.
2568 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
2572 (Only for MPC8260 CPU). The I/O port to use (the code
2573 assumes both bits are on the same port). Valid values
2574 are 0..3 for ports A..D.
2578 The code necessary to make the I2C data line active
2579 (driven). If the data line is open collector, this
2582 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
2586 The code necessary to make the I2C data line tri-stated
2587 (inactive). If the data line is open collector, this
2590 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
2594 Code that returns true if the I2C data line is high,
2597 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
2601 If <bit> is true, sets the I2C data line high. If it
2602 is false, it clears it (low).
2604 eg: #define I2C_SDA(bit) \
2605 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
2606 else immr->im_cpm.cp_pbdat &= ~PB_SDA
2610 If <bit> is true, sets the I2C clock line high. If it
2611 is false, it clears it (low).
2613 eg: #define I2C_SCL(bit) \
2614 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
2615 else immr->im_cpm.cp_pbdat &= ~PB_SCL
2619 This delay is invoked four times per clock cycle so this
2620 controls the rate of data transfer. The data rate thus
2621 is 1 / (I2C_DELAY * 4). Often defined to be something
2624 #define I2C_DELAY udelay(2)
2626 CONFIG_SOFT_I2C_GPIO_SCL / CONFIG_SOFT_I2C_GPIO_SDA
2628 If your arch supports the generic GPIO framework (asm/gpio.h),
2629 then you may alternatively define the two GPIOs that are to be
2630 used as SCL / SDA. Any of the previous I2C_xxx macros will
2631 have GPIO-based defaults assigned to them as appropriate.
2633 You should define these to the GPIO value as given directly to
2634 the generic GPIO functions.
2636 CONFIG_SYS_I2C_INIT_BOARD
2638 When a board is reset during an i2c bus transfer
2639 chips might think that the current transfer is still
2640 in progress. On some boards it is possible to access
2641 the i2c SCLK line directly, either by using the
2642 processor pin as a GPIO or by having a second pin
2643 connected to the bus. If this option is defined a
2644 custom i2c_init_board() routine in boards/xxx/board.c
2645 is run early in the boot sequence.
2647 CONFIG_SYS_I2C_BOARD_LATE_INIT
2649 An alternative to CONFIG_SYS_I2C_INIT_BOARD. If this option is
2650 defined a custom i2c_board_late_init() routine in
2651 boards/xxx/board.c is run AFTER the operations in i2c_init()
2652 is completed. This callpoint can be used to unreset i2c bus
2653 using CPU i2c controller register accesses for CPUs whose i2c
2654 controller provide such a method. It is called at the end of
2655 i2c_init() to allow i2c_init operations to setup the i2c bus
2656 controller on the CPU (e.g. setting bus speed & slave address).
2658 CONFIG_I2CFAST (PPC405GP|PPC405EP only)
2660 This option enables configuration of bi_iic_fast[] flags
2661 in u-boot bd_info structure based on u-boot environment
2662 variable "i2cfast". (see also i2cfast)
2664 CONFIG_I2C_MULTI_BUS
2666 This option allows the use of multiple I2C buses, each of which
2667 must have a controller. At any point in time, only one bus is
2668 active. To switch to a different bus, use the 'i2c dev' command.
2669 Note that bus numbering is zero-based.
2671 CONFIG_SYS_I2C_NOPROBES
2673 This option specifies a list of I2C devices that will be skipped
2674 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS
2675 is set, specify a list of bus-device pairs. Otherwise, specify
2676 a 1D array of device addresses
2679 #undef CONFIG_I2C_MULTI_BUS
2680 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68}
2682 will skip addresses 0x50 and 0x68 on a board with one I2C bus
2684 #define CONFIG_I2C_MULTI_BUS
2685 #define CONFIG_SYS_I2C_MULTI_NOPROBES {{0,0x50},{0,0x68},{1,0x54}}
2687 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1
2689 CONFIG_SYS_SPD_BUS_NUM
2691 If defined, then this indicates the I2C bus number for DDR SPD.
2692 If not defined, then U-Boot assumes that SPD is on I2C bus 0.
2694 CONFIG_SYS_RTC_BUS_NUM
2696 If defined, then this indicates the I2C bus number for the RTC.
2697 If not defined, then U-Boot assumes that RTC is on I2C bus 0.
2699 CONFIG_SYS_DTT_BUS_NUM
2701 If defined, then this indicates the I2C bus number for the DTT.
2702 If not defined, then U-Boot assumes that DTT is on I2C bus 0.
2704 CONFIG_SYS_I2C_DTT_ADDR:
2706 If defined, specifies the I2C address of the DTT device.
2707 If not defined, then U-Boot uses predefined value for
2708 specified DTT device.
2710 CONFIG_SOFT_I2C_READ_REPEATED_START
2712 defining this will force the i2c_read() function in
2713 the soft_i2c driver to perform an I2C repeated start
2714 between writing the address pointer and reading the
2715 data. If this define is omitted the default behaviour
2716 of doing a stop-start sequence will be used. Most I2C
2717 devices can use either method, but some require one or
2720 - SPI Support: CONFIG_SPI
2722 Enables SPI driver (so far only tested with
2723 SPI EEPROM, also an instance works with Crystal A/D and
2724 D/As on the SACSng board)
2728 Enables the driver for SPI controller on SuperH. Currently
2729 only SH7757 is supported.
2733 Enables extended (16-bit) SPI EEPROM addressing.
2734 (symmetrical to CONFIG_I2C_X)
2738 Enables a software (bit-bang) SPI driver rather than
2739 using hardware support. This is a general purpose
2740 driver that only requires three general I/O port pins
2741 (two outputs, one input) to function. If this is
2742 defined, the board configuration must define several
2743 SPI configuration items (port pins to use, etc). For
2744 an example, see include/configs/sacsng.h.
2748 Enables a hardware SPI driver for general-purpose reads
2749 and writes. As with CONFIG_SOFT_SPI, the board configuration
2750 must define a list of chip-select function pointers.
2751 Currently supported on some MPC8xxx processors. For an
2752 example, see include/configs/mpc8349emds.h.
2756 Enables the driver for the SPI controllers on i.MX and MXC
2757 SoCs. Currently i.MX31/35/51 are supported.
2759 CONFIG_SYS_SPI_MXC_WAIT
2760 Timeout for waiting until spi transfer completed.
2761 default: (CONFIG_SYS_HZ/100) /* 10 ms */
2763 - FPGA Support: CONFIG_FPGA
2765 Enables FPGA subsystem.
2767 CONFIG_FPGA_<vendor>
2769 Enables support for specific chip vendors.
2772 CONFIG_FPGA_<family>
2774 Enables support for FPGA family.
2775 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX)
2779 Specify the number of FPGA devices to support.
2781 CONFIG_CMD_FPGA_LOADMK
2783 Enable support for fpga loadmk command
2785 CONFIG_CMD_FPGA_LOADP
2787 Enable support for fpga loadp command - load partial bitstream
2789 CONFIG_CMD_FPGA_LOADBP
2791 Enable support for fpga loadbp command - load partial bitstream
2794 CONFIG_SYS_FPGA_PROG_FEEDBACK
2796 Enable printing of hash marks during FPGA configuration.
2798 CONFIG_SYS_FPGA_CHECK_BUSY
2800 Enable checks on FPGA configuration interface busy
2801 status by the configuration function. This option
2802 will require a board or device specific function to
2807 If defined, a function that provides delays in the FPGA
2808 configuration driver.
2810 CONFIG_SYS_FPGA_CHECK_CTRLC
2811 Allow Control-C to interrupt FPGA configuration
2813 CONFIG_SYS_FPGA_CHECK_ERROR
2815 Check for configuration errors during FPGA bitfile
2816 loading. For example, abort during Virtex II
2817 configuration if the INIT_B line goes low (which
2818 indicated a CRC error).
2820 CONFIG_SYS_FPGA_WAIT_INIT
2822 Maximum time to wait for the INIT_B line to de-assert
2823 after PROB_B has been de-asserted during a Virtex II
2824 FPGA configuration sequence. The default time is 500
2827 CONFIG_SYS_FPGA_WAIT_BUSY
2829 Maximum time to wait for BUSY to de-assert during
2830 Virtex II FPGA configuration. The default is 5 ms.
2832 CONFIG_SYS_FPGA_WAIT_CONFIG
2834 Time to wait after FPGA configuration. The default is
2837 - Configuration Management:
2840 Some SoCs need special image types (e.g. U-Boot binary
2841 with a special header) as build targets. By defining
2842 CONFIG_BUILD_TARGET in the SoC / board header, this
2843 special image will be automatically built upon calling
2848 If defined, this string will be added to the U-Boot
2849 version information (U_BOOT_VERSION)
2851 - Vendor Parameter Protection:
2853 U-Boot considers the values of the environment
2854 variables "serial#" (Board Serial Number) and
2855 "ethaddr" (Ethernet Address) to be parameters that
2856 are set once by the board vendor / manufacturer, and
2857 protects these variables from casual modification by
2858 the user. Once set, these variables are read-only,
2859 and write or delete attempts are rejected. You can
2860 change this behaviour:
2862 If CONFIG_ENV_OVERWRITE is #defined in your config
2863 file, the write protection for vendor parameters is
2864 completely disabled. Anybody can change or delete
2867 Alternatively, if you define _both_ an ethaddr in the
2868 default env _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
2869 Ethernet address is installed in the environment,
2870 which can be changed exactly ONCE by the user. [The
2871 serial# is unaffected by this, i. e. it remains
2874 The same can be accomplished in a more flexible way
2875 for any variable by configuring the type of access
2876 to allow for those variables in the ".flags" variable
2877 or define CONFIG_ENV_FLAGS_LIST_STATIC.
2882 Define this variable to enable the reservation of
2883 "protected RAM", i. e. RAM which is not overwritten
2884 by U-Boot. Define CONFIG_PRAM to hold the number of
2885 kB you want to reserve for pRAM. You can overwrite
2886 this default value by defining an environment
2887 variable "pram" to the number of kB you want to
2888 reserve. Note that the board info structure will
2889 still show the full amount of RAM. If pRAM is
2890 reserved, a new environment variable "mem" will
2891 automatically be defined to hold the amount of
2892 remaining RAM in a form that can be passed as boot
2893 argument to Linux, for instance like that:
2895 setenv bootargs ... mem=\${mem}
2898 This way you can tell Linux not to use this memory,
2899 either, which results in a memory region that will
2900 not be affected by reboots.
2902 *WARNING* If your board configuration uses automatic
2903 detection of the RAM size, you must make sure that
2904 this memory test is non-destructive. So far, the
2905 following board configurations are known to be
2908 IVMS8, IVML24, SPD8xx, TQM8xxL,
2909 HERMES, IP860, RPXlite, LWMON,
2912 - Access to physical memory region (> 4GB)
2913 Some basic support is provided for operations on memory not
2914 normally accessible to U-Boot - e.g. some architectures
2915 support access to more than 4GB of memory on 32-bit
2916 machines using physical address extension or similar.
2917 Define CONFIG_PHYSMEM to access this basic support, which
2918 currently only supports clearing the memory.
2923 Define this variable to stop the system in case of a
2924 fatal error, so that you have to reset it manually.
2925 This is probably NOT a good idea for an embedded
2926 system where you want the system to reboot
2927 automatically as fast as possible, but it may be
2928 useful during development since you can try to debug
2929 the conditions that lead to the situation.
2931 CONFIG_NET_RETRY_COUNT
2933 This variable defines the number of retries for
2934 network operations like ARP, RARP, TFTP, or BOOTP
2935 before giving up the operation. If not defined, a
2936 default value of 5 is used.
2940 Timeout waiting for an ARP reply in milliseconds.
2944 Timeout in milliseconds used in NFS protocol.
2945 If you encounter "ERROR: Cannot umount" in nfs command,
2946 try longer timeout such as
2947 #define CONFIG_NFS_TIMEOUT 10000UL
2949 - Command Interpreter:
2950 CONFIG_AUTO_COMPLETE
2952 Enable auto completion of commands using TAB.
2954 CONFIG_SYS_PROMPT_HUSH_PS2
2956 This defines the secondary prompt string, which is
2957 printed when the command interpreter needs more input
2958 to complete a command. Usually "> ".
2962 In the current implementation, the local variables
2963 space and global environment variables space are
2964 separated. Local variables are those you define by
2965 simply typing `name=value'. To access a local
2966 variable later on, you have write `$name' or
2967 `${name}'; to execute the contents of a variable
2968 directly type `$name' at the command prompt.
2970 Global environment variables are those you use
2971 setenv/printenv to work with. To run a command stored
2972 in such a variable, you need to use the run command,
2973 and you must not use the '$' sign to access them.
2975 To store commands and special characters in a
2976 variable, please use double quotation marks
2977 surrounding the whole text of the variable, instead
2978 of the backslashes before semicolons and special
2981 - Command Line Editing and History:
2982 CONFIG_CMDLINE_EDITING
2984 Enable editing and History functions for interactive
2985 command line input operations
2987 - Default Environment:
2988 CONFIG_EXTRA_ENV_SETTINGS
2990 Define this to contain any number of null terminated
2991 strings (variable = value pairs) that will be part of
2992 the default environment compiled into the boot image.
2994 For example, place something like this in your
2995 board's config file:
2997 #define CONFIG_EXTRA_ENV_SETTINGS \
3001 Warning: This method is based on knowledge about the
3002 internal format how the environment is stored by the
3003 U-Boot code. This is NOT an official, exported
3004 interface! Although it is unlikely that this format
3005 will change soon, there is no guarantee either.
3006 You better know what you are doing here.
3008 Note: overly (ab)use of the default environment is
3009 discouraged. Make sure to check other ways to preset
3010 the environment like the "source" command or the
3013 CONFIG_ENV_VARS_UBOOT_CONFIG
3015 Define this in order to add variables describing the
3016 U-Boot build configuration to the default environment.
3017 These will be named arch, cpu, board, vendor, and soc.
3019 Enabling this option will cause the following to be defined:
3027 CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG
3029 Define this in order to add variables describing certain
3030 run-time determined information about the hardware to the
3031 environment. These will be named board_name, board_rev.
3033 CONFIG_DELAY_ENVIRONMENT
3035 Normally the environment is loaded when the board is
3036 initialised so that it is available to U-Boot. This inhibits
3037 that so that the environment is not available until
3038 explicitly loaded later by U-Boot code. With CONFIG_OF_CONTROL
3039 this is instead controlled by the value of
3040 /config/load-environment.
3042 - Parallel Flash support:
3045 Traditionally U-boot was run on systems with parallel NOR
3046 flash. This option is used to disable support for parallel NOR
3047 flash. This option should be defined if the board does not have
3050 If this option is not defined one of the generic flash drivers
3051 (e.g. CONFIG_FLASH_CFI_DRIVER or CONFIG_ST_SMI) must be
3052 selected or the board must provide an implementation of the
3053 flash API (see include/flash.h).
3055 - DataFlash Support:
3056 CONFIG_HAS_DATAFLASH
3058 Defining this option enables DataFlash features and
3059 allows to read/write in Dataflash via the standard
3062 - Serial Flash support
3065 Defining this option enables SPI flash commands
3066 'sf probe/read/write/erase/update'.
3068 Usage requires an initial 'probe' to define the serial
3069 flash parameters, followed by read/write/erase/update
3072 The following defaults may be provided by the platform
3073 to handle the common case when only a single serial
3074 flash is present on the system.
3076 CONFIG_SF_DEFAULT_BUS Bus identifier
3077 CONFIG_SF_DEFAULT_CS Chip-select
3078 CONFIG_SF_DEFAULT_MODE (see include/spi.h)
3079 CONFIG_SF_DEFAULT_SPEED in Hz
3083 Define this option to include a destructive SPI flash
3086 CONFIG_SF_DUAL_FLASH Dual flash memories
3088 Define this option to use dual flash support where two flash
3089 memories can be connected with a given cs line.
3090 Currently Xilinx Zynq qspi supports these type of connections.
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:
3214 Legacy uImage format:
3217 1 common/cmd_bootm.c before attempting to boot an image
3218 -1 common/cmd_bootm.c Image header has bad magic number
3219 2 common/cmd_bootm.c Image header has correct magic number
3220 -2 common/cmd_bootm.c Image header has bad checksum
3221 3 common/cmd_bootm.c Image header has correct checksum
3222 -3 common/cmd_bootm.c Image data has bad checksum
3223 4 common/cmd_bootm.c Image data has correct checksum
3224 -4 common/cmd_bootm.c Image is for unsupported architecture
3225 5 common/cmd_bootm.c Architecture check OK
3226 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi)
3227 6 common/cmd_bootm.c Image Type check OK
3228 -6 common/cmd_bootm.c gunzip uncompression error
3229 -7 common/cmd_bootm.c Unimplemented compression type
3230 7 common/cmd_bootm.c Uncompression OK
3231 8 common/cmd_bootm.c No uncompress/copy overwrite error
3232 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX)
3234 9 common/image.c Start initial ramdisk verification
3235 -10 common/image.c Ramdisk header has bad magic number
3236 -11 common/image.c Ramdisk header has bad checksum
3237 10 common/image.c Ramdisk header is OK
3238 -12 common/image.c Ramdisk data has bad checksum
3239 11 common/image.c Ramdisk data has correct checksum
3240 12 common/image.c Ramdisk verification complete, start loading
3241 -13 common/image.c Wrong Image Type (not PPC Linux ramdisk)
3242 13 common/image.c Start multifile image verification
3243 14 common/image.c No initial ramdisk, no multifile, continue.
3245 15 arch/<arch>/lib/bootm.c All preparation done, transferring control to OS
3247 -30 arch/powerpc/lib/board.c Fatal error, hang the system
3248 -31 post/post.c POST test failed, detected by post_output_backlog()
3249 -32 post/post.c POST test failed, detected by post_run_single()
3251 34 common/cmd_doc.c before loading a Image from a DOC device
3252 -35 common/cmd_doc.c Bad usage of "doc" command
3253 35 common/cmd_doc.c correct usage of "doc" command
3254 -36 common/cmd_doc.c No boot device
3255 36 common/cmd_doc.c correct boot device
3256 -37 common/cmd_doc.c Unknown Chip ID on boot device
3257 37 common/cmd_doc.c correct chip ID found, device available
3258 -38 common/cmd_doc.c Read Error on boot device
3259 38 common/cmd_doc.c reading Image header from DOC device OK
3260 -39 common/cmd_doc.c Image header has bad magic number
3261 39 common/cmd_doc.c Image header has correct magic number
3262 -40 common/cmd_doc.c Error reading Image from DOC device
3263 40 common/cmd_doc.c Image header has correct magic number
3264 41 common/cmd_ide.c before loading a Image from a IDE device
3265 -42 common/cmd_ide.c Bad usage of "ide" command
3266 42 common/cmd_ide.c correct usage of "ide" command
3267 -43 common/cmd_ide.c No boot device
3268 43 common/cmd_ide.c boot device found
3269 -44 common/cmd_ide.c Device not available
3270 44 common/cmd_ide.c Device available
3271 -45 common/cmd_ide.c wrong partition selected
3272 45 common/cmd_ide.c partition selected
3273 -46 common/cmd_ide.c Unknown partition table
3274 46 common/cmd_ide.c valid partition table found
3275 -47 common/cmd_ide.c Invalid partition type
3276 47 common/cmd_ide.c correct partition type
3277 -48 common/cmd_ide.c Error reading Image Header on boot device
3278 48 common/cmd_ide.c reading Image Header from IDE device OK
3279 -49 common/cmd_ide.c Image header has bad magic number
3280 49 common/cmd_ide.c Image header has correct magic number
3281 -50 common/cmd_ide.c Image header has bad checksum
3282 50 common/cmd_ide.c Image header has correct checksum
3283 -51 common/cmd_ide.c Error reading Image from IDE device
3284 51 common/cmd_ide.c reading Image from IDE device OK
3285 52 common/cmd_nand.c before loading a Image from a NAND device
3286 -53 common/cmd_nand.c Bad usage of "nand" command
3287 53 common/cmd_nand.c correct usage of "nand" command
3288 -54 common/cmd_nand.c No boot device
3289 54 common/cmd_nand.c boot device found
3290 -55 common/cmd_nand.c Unknown Chip ID on boot device
3291 55 common/cmd_nand.c correct chip ID found, device available
3292 -56 common/cmd_nand.c Error reading Image Header on boot device
3293 56 common/cmd_nand.c reading Image Header from NAND device OK
3294 -57 common/cmd_nand.c Image header has bad magic number
3295 57 common/cmd_nand.c Image header has correct magic number
3296 -58 common/cmd_nand.c Error reading Image from NAND device
3297 58 common/cmd_nand.c reading Image from NAND device OK
3299 -60 common/env_common.c Environment has a bad CRC, using default
3301 64 net/eth.c starting with Ethernet configuration.
3302 -64 net/eth.c no Ethernet found.
3303 65 net/eth.c Ethernet found.
3305 -80 common/cmd_net.c usage wrong
3306 80 common/cmd_net.c before calling net_loop()
3307 -81 common/cmd_net.c some error in net_loop() occurred
3308 81 common/cmd_net.c net_loop() back without error
3309 -82 common/cmd_net.c size == 0 (File with size 0 loaded)
3310 82 common/cmd_net.c trying automatic boot
3311 83 common/cmd_net.c running "source" command
3312 -83 common/cmd_net.c some error in automatic boot or "source" command
3313 84 common/cmd_net.c end without errors
3318 100 common/cmd_bootm.c Kernel FIT Image has correct format
3319 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format
3320 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration
3321 -101 common/cmd_bootm.c Can't get configuration for kernel subimage
3322 102 common/cmd_bootm.c Kernel unit name specified
3323 -103 common/cmd_bootm.c Can't get kernel subimage node offset
3324 103 common/cmd_bootm.c Found configuration node
3325 104 common/cmd_bootm.c Got kernel subimage node offset
3326 -104 common/cmd_bootm.c Kernel subimage hash verification failed
3327 105 common/cmd_bootm.c Kernel subimage hash verification OK
3328 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture
3329 106 common/cmd_bootm.c Architecture check OK
3330 -106 common/cmd_bootm.c Kernel subimage has wrong type
3331 107 common/cmd_bootm.c Kernel subimage type OK
3332 -107 common/cmd_bootm.c Can't get kernel subimage data/size
3333 108 common/cmd_bootm.c Got kernel subimage data/size
3334 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT)
3335 -109 common/cmd_bootm.c Can't get kernel subimage type
3336 -110 common/cmd_bootm.c Can't get kernel subimage comp
3337 -111 common/cmd_bootm.c Can't get kernel subimage os
3338 -112 common/cmd_bootm.c Can't get kernel subimage load address
3339 -113 common/cmd_bootm.c Image uncompress/copy overwrite error
3341 120 common/image.c Start initial ramdisk verification
3342 -120 common/image.c Ramdisk FIT image has incorrect format
3343 121 common/image.c Ramdisk FIT image has correct format
3344 122 common/image.c No ramdisk subimage unit name, using configuration
3345 -122 common/image.c Can't get configuration for ramdisk subimage
3346 123 common/image.c Ramdisk unit name specified
3347 -124 common/image.c Can't get ramdisk subimage node offset
3348 125 common/image.c Got ramdisk subimage node offset
3349 -125 common/image.c Ramdisk subimage hash verification failed
3350 126 common/image.c Ramdisk subimage hash verification OK
3351 -126 common/image.c Ramdisk subimage for unsupported architecture
3352 127 common/image.c Architecture check OK
3353 -127 common/image.c Can't get ramdisk subimage data/size
3354 128 common/image.c Got ramdisk subimage data/size
3355 129 common/image.c Can't get ramdisk load address
3356 -129 common/image.c Got ramdisk load address
3358 -130 common/cmd_doc.c Incorrect FIT image format
3359 131 common/cmd_doc.c FIT image format OK
3361 -140 common/cmd_ide.c Incorrect FIT image format
3362 141 common/cmd_ide.c FIT image format OK
3364 -150 common/cmd_nand.c Incorrect FIT image format
3365 151 common/cmd_nand.c FIT image format OK
3367 - legacy image format:
3368 CONFIG_IMAGE_FORMAT_LEGACY
3369 enables the legacy image format support in U-Boot.
3372 enabled if CONFIG_FIT_SIGNATURE is not defined.
3374 CONFIG_DISABLE_IMAGE_LEGACY
3375 disable the legacy image format
3377 This define is introduced, as the legacy image format is
3378 enabled per default for backward compatibility.
3380 - FIT image support:
3382 Enable support for the FIT uImage format.
3384 CONFIG_FIT_BEST_MATCH
3385 When no configuration is explicitly selected, default to the
3386 one whose fdt's compatibility field best matches that of
3387 U-Boot itself. A match is considered "best" if it matches the
3388 most specific compatibility entry of U-Boot's fdt's root node.
3389 The order of entries in the configuration's fdt is ignored.
3391 CONFIG_FIT_SIGNATURE
3392 This option enables signature verification of FIT uImages,
3393 using a hash signed and verified using RSA. If
3394 CONFIG_SHA_PROG_HW_ACCEL is defined, i.e support for progressive
3395 hashing is available using hardware, RSA library will use it.
3396 See doc/uImage.FIT/signature.txt for more details.
3398 WARNING: When relying on signed FIT images with required
3399 signature check the legacy image format is default
3400 disabled. If a board need legacy image format support
3401 enable this through CONFIG_IMAGE_FORMAT_LEGACY
3403 CONFIG_FIT_DISABLE_SHA256
3404 Supporting SHA256 hashes has quite an impact on binary size.
3405 For constrained systems sha256 hash support can be disabled
3408 - Standalone program support:
3409 CONFIG_STANDALONE_LOAD_ADDR
3411 This option defines a board specific value for the
3412 address where standalone program gets loaded, thus
3413 overwriting the architecture dependent default
3416 - Frame Buffer Address:
3419 Define CONFIG_FB_ADDR if you want to use specific
3420 address for frame buffer. This is typically the case
3421 when using a graphics controller has separate video
3422 memory. U-Boot will then place the frame buffer at
3423 the given address instead of dynamically reserving it
3424 in system RAM by calling lcd_setmem(), which grabs
3425 the memory for the frame buffer depending on the
3426 configured panel size.
3428 Please see board_init_f function.
3430 - Automatic software updates via TFTP server
3432 CONFIG_UPDATE_TFTP_CNT_MAX
3433 CONFIG_UPDATE_TFTP_MSEC_MAX
3435 These options enable and control the auto-update feature;
3436 for a more detailed description refer to doc/README.update.
3438 - MTD Support (mtdparts command, UBI support)
3441 Adds the MTD device infrastructure from the Linux kernel.
3442 Needed for mtdparts command support.
3444 CONFIG_MTD_PARTITIONS
3446 Adds the MTD partitioning infrastructure from the Linux
3447 kernel. Needed for UBI support.
3452 Adds commands for interacting with MTD partitions formatted
3453 with the UBI flash translation layer
3455 Requires also defining CONFIG_RBTREE
3457 CONFIG_UBI_SILENCE_MSG
3459 Make the verbose messages from UBI stop printing. This leaves
3460 warnings and errors enabled.
3463 CONFIG_MTD_UBI_WL_THRESHOLD
3464 This parameter defines the maximum difference between the highest
3465 erase counter value and the lowest erase counter value of eraseblocks
3466 of UBI devices. When this threshold is exceeded, UBI starts performing
3467 wear leveling by means of moving data from eraseblock with low erase
3468 counter to eraseblocks with high erase counter.
3470 The default value should be OK for SLC NAND flashes, NOR flashes and
3471 other flashes which have eraseblock life-cycle 100000 or more.
3472 However, in case of MLC NAND flashes which typically have eraseblock
3473 life-cycle less than 10000, the threshold should be lessened (e.g.,
3474 to 128 or 256, although it does not have to be power of 2).
3478 CONFIG_MTD_UBI_BEB_LIMIT
3479 This option specifies the maximum bad physical eraseblocks UBI
3480 expects on the MTD device (per 1024 eraseblocks). If the
3481 underlying flash does not admit of bad eraseblocks (e.g. NOR
3482 flash), this value is ignored.
3484 NAND datasheets often specify the minimum and maximum NVM
3485 (Number of Valid Blocks) for the flashes' endurance lifetime.
3486 The maximum expected bad eraseblocks per 1024 eraseblocks
3487 then can be calculated as "1024 * (1 - MinNVB / MaxNVB)",
3488 which gives 20 for most NANDs (MaxNVB is basically the total
3489 count of eraseblocks on the chip).
3491 To put it differently, if this value is 20, UBI will try to
3492 reserve about 1.9% of physical eraseblocks for bad blocks
3493 handling. And that will be 1.9% of eraseblocks on the entire
3494 NAND chip, not just the MTD partition UBI attaches. This means
3495 that if you have, say, a NAND flash chip admits maximum 40 bad
3496 eraseblocks, and it is split on two MTD partitions of the same
3497 size, UBI will reserve 40 eraseblocks when attaching a
3502 CONFIG_MTD_UBI_FASTMAP
3503 Fastmap is a mechanism which allows attaching an UBI device
3504 in nearly constant time. Instead of scanning the whole MTD device it
3505 only has to locate a checkpoint (called fastmap) on the device.
3506 The on-flash fastmap contains all information needed to attach
3507 the device. Using fastmap makes only sense on large devices where
3508 attaching by scanning takes long. UBI will not automatically install
3509 a fastmap on old images, but you can set the UBI parameter
3510 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT to 1 if you want so. Please note
3511 that fastmap-enabled images are still usable with UBI implementations
3512 without fastmap support. On typical flash devices the whole fastmap
3513 fits into one PEB. UBI will reserve PEBs to hold two fastmaps.
3515 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT
3516 Set this parameter to enable fastmap automatically on images
3523 Adds commands for interacting with UBI volumes formatted as
3524 UBIFS. UBIFS is read-only in u-boot.
3526 Requires UBI support as well as CONFIG_LZO
3528 CONFIG_UBIFS_SILENCE_MSG
3530 Make the verbose messages from UBIFS stop printing. This leaves
3531 warnings and errors enabled.
3535 Enable building of SPL globally.
3538 LDSCRIPT for linking the SPL binary.
3540 CONFIG_SPL_MAX_FOOTPRINT
3541 Maximum size in memory allocated to the SPL, BSS included.
3542 When defined, the linker checks that the actual memory
3543 used by SPL from _start to __bss_end does not exceed it.
3544 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
3545 must not be both defined at the same time.
3548 Maximum size of the SPL image (text, data, rodata, and
3549 linker lists sections), BSS excluded.
3550 When defined, the linker checks that the actual size does
3553 CONFIG_SPL_TEXT_BASE
3554 TEXT_BASE for linking the SPL binary.
3556 CONFIG_SPL_RELOC_TEXT_BASE
3557 Address to relocate to. If unspecified, this is equal to
3558 CONFIG_SPL_TEXT_BASE (i.e. no relocation is done).
3560 CONFIG_SPL_BSS_START_ADDR
3561 Link address for the BSS within the SPL binary.
3563 CONFIG_SPL_BSS_MAX_SIZE
3564 Maximum size in memory allocated to the SPL BSS.
3565 When defined, the linker checks that the actual memory used
3566 by SPL from __bss_start to __bss_end does not exceed it.
3567 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
3568 must not be both defined at the same time.
3571 Adress of the start of the stack SPL will use
3573 CONFIG_SPL_PANIC_ON_RAW_IMAGE
3574 When defined, SPL will panic() if the image it has
3575 loaded does not have a signature.
3576 Defining this is useful when code which loads images
3577 in SPL cannot guarantee that absolutely all read errors
3579 An example is the LPC32XX MLC NAND driver, which will
3580 consider that a completely unreadable NAND block is bad,
3581 and thus should be skipped silently.
3583 CONFIG_SPL_RELOC_STACK
3584 Adress of the start of the stack SPL will use after
3585 relocation. If unspecified, this is equal to
3588 CONFIG_SYS_SPL_MALLOC_START
3589 Starting address of the malloc pool used in SPL.
3591 CONFIG_SYS_SPL_MALLOC_SIZE
3592 The size of the malloc pool used in SPL.
3594 CONFIG_SPL_FRAMEWORK
3595 Enable the SPL framework under common/. This framework
3596 supports MMC, NAND and YMODEM loading of U-Boot and NAND
3597 NAND loading of the Linux Kernel.
3600 Enable booting directly to an OS from SPL.
3601 See also: doc/README.falcon
3603 CONFIG_SPL_DISPLAY_PRINT
3604 For ARM, enable an optional function to print more information
3605 about the running system.
3607 CONFIG_SPL_INIT_MINIMAL
3608 Arch init code should be built for a very small image
3610 CONFIG_SPL_LIBCOMMON_SUPPORT
3611 Support for common/libcommon.o in SPL binary
3613 CONFIG_SPL_LIBDISK_SUPPORT
3614 Support for disk/libdisk.o in SPL binary
3616 CONFIG_SPL_I2C_SUPPORT
3617 Support for drivers/i2c/libi2c.o in SPL binary
3619 CONFIG_SPL_GPIO_SUPPORT
3620 Support for drivers/gpio/libgpio.o in SPL binary
3622 CONFIG_SPL_MMC_SUPPORT
3623 Support for drivers/mmc/libmmc.o in SPL binary
3625 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_SECTOR,
3626 CONFIG_SYS_U_BOOT_MAX_SIZE_SECTORS,
3627 Address and partition on the MMC to load U-Boot from
3628 when the MMC is being used in raw mode.
3630 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_PARTITION
3631 Partition on the MMC to load U-Boot from when the MMC is being
3634 CONFIG_SYS_MMCSD_RAW_MODE_KERNEL_SECTOR
3635 Sector to load kernel uImage from when MMC is being
3636 used in raw mode (for Falcon mode)
3638 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTOR,
3639 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTORS
3640 Sector and number of sectors to load kernel argument
3641 parameters from when MMC is being used in raw mode
3644 CONFIG_SYS_MMCSD_FS_BOOT_PARTITION
3645 Partition on the MMC to load U-Boot from when the MMC is being
3648 CONFIG_SPL_FAT_SUPPORT
3649 Support for fs/fat/libfat.o in SPL binary
3651 CONFIG_SPL_EXT_SUPPORT
3652 Support for EXT filesystem in SPL binary
3654 CONFIG_SPL_FS_LOAD_PAYLOAD_NAME
3655 Filename to read to load U-Boot when reading from filesystem
3657 CONFIG_SPL_FS_LOAD_KERNEL_NAME
3658 Filename to read to load kernel uImage when reading
3659 from filesystem (for Falcon mode)
3661 CONFIG_SPL_FS_LOAD_ARGS_NAME
3662 Filename to read to load kernel argument parameters
3663 when reading from filesystem (for Falcon mode)
3665 CONFIG_SPL_MPC83XX_WAIT_FOR_NAND
3666 Set this for NAND SPL on PPC mpc83xx targets, so that
3667 start.S waits for the rest of the SPL to load before
3668 continuing (the hardware starts execution after just
3669 loading the first page rather than the full 4K).
3671 CONFIG_SPL_SKIP_RELOCATE
3672 Avoid SPL relocation
3674 CONFIG_SPL_NAND_BASE
3675 Include nand_base.c in the SPL. Requires
3676 CONFIG_SPL_NAND_DRIVERS.
3678 CONFIG_SPL_NAND_DRIVERS
3679 SPL uses normal NAND drivers, not minimal drivers.
3682 Include standard software ECC in the SPL
3684 CONFIG_SPL_NAND_SIMPLE
3685 Support for NAND boot using simple NAND drivers that
3686 expose the cmd_ctrl() interface.
3688 CONFIG_SPL_MTD_SUPPORT
3689 Support for the MTD subsystem within SPL. Useful for
3690 environment on NAND support within SPL.
3692 CONFIG_SPL_NAND_RAW_ONLY
3693 Support to boot only raw u-boot.bin images. Use this only
3694 if you need to save space.
3696 CONFIG_SPL_MPC8XXX_INIT_DDR_SUPPORT
3697 Set for the SPL on PPC mpc8xxx targets, support for
3698 drivers/ddr/fsl/libddr.o in SPL binary.
3700 CONFIG_SPL_COMMON_INIT_DDR
3701 Set for common ddr init with serial presence detect in
3704 CONFIG_SYS_NAND_5_ADDR_CYCLE, CONFIG_SYS_NAND_PAGE_COUNT,
3705 CONFIG_SYS_NAND_PAGE_SIZE, CONFIG_SYS_NAND_OOBSIZE,
3706 CONFIG_SYS_NAND_BLOCK_SIZE, CONFIG_SYS_NAND_BAD_BLOCK_POS,
3707 CONFIG_SYS_NAND_ECCPOS, CONFIG_SYS_NAND_ECCSIZE,
3708 CONFIG_SYS_NAND_ECCBYTES
3709 Defines the size and behavior of the NAND that SPL uses
3712 CONFIG_SPL_NAND_BOOT
3713 Add support NAND boot
3715 CONFIG_SYS_NAND_U_BOOT_OFFS
3716 Location in NAND to read U-Boot from
3718 CONFIG_SYS_NAND_U_BOOT_DST
3719 Location in memory to load U-Boot to
3721 CONFIG_SYS_NAND_U_BOOT_SIZE
3722 Size of image to load
3724 CONFIG_SYS_NAND_U_BOOT_START
3725 Entry point in loaded image to jump to
3727 CONFIG_SYS_NAND_HW_ECC_OOBFIRST
3728 Define this if you need to first read the OOB and then the
3729 data. This is used, for example, on davinci platforms.
3731 CONFIG_SPL_OMAP3_ID_NAND
3732 Support for an OMAP3-specific set of functions to return the
3733 ID and MFR of the first attached NAND chip, if present.
3735 CONFIG_SPL_SERIAL_SUPPORT
3736 Support for drivers/serial/libserial.o in SPL binary
3738 CONFIG_SPL_SPI_FLASH_SUPPORT
3739 Support for drivers/mtd/spi/libspi_flash.o in SPL binary
3741 CONFIG_SPL_SPI_SUPPORT
3742 Support for drivers/spi/libspi.o in SPL binary
3744 CONFIG_SPL_RAM_DEVICE
3745 Support for running image already present in ram, in SPL binary
3747 CONFIG_SPL_LIBGENERIC_SUPPORT
3748 Support for lib/libgeneric.o in SPL binary
3750 CONFIG_SPL_ENV_SUPPORT
3751 Support for the environment operating in SPL binary
3753 CONFIG_SPL_NET_SUPPORT
3754 Support for the net/libnet.o in SPL binary.
3755 It conflicts with SPL env from storage medium specified by
3756 CONFIG_ENV_IS_xxx but CONFIG_ENV_IS_NOWHERE
3759 Image offset to which the SPL should be padded before appending
3760 the SPL payload. By default, this is defined as
3761 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3762 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3763 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3766 Final target image containing SPL and payload. Some SPLs
3767 use an arch-specific makefile fragment instead, for
3768 example if more than one image needs to be produced.
3770 CONFIG_FIT_SPL_PRINT
3771 Printing information about a FIT image adds quite a bit of
3772 code to SPL. So this is normally disabled in SPL. Use this
3773 option to re-enable it. This will affect the output of the
3774 bootm command when booting a FIT image.
3778 Enable building of TPL globally.
3781 Image offset to which the TPL should be padded before appending
3782 the TPL payload. By default, this is defined as
3783 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3784 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3785 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3790 [so far only for SMDK2400 boards]
3792 - Modem support enable:
3793 CONFIG_MODEM_SUPPORT
3795 - RTS/CTS Flow control enable:
3798 - Modem debug support:
3799 CONFIG_MODEM_SUPPORT_DEBUG
3801 Enables debugging stuff (char screen[1024], dbg())
3802 for modem support. Useful only with BDI2000.
3804 - Interrupt support (PPC):
3806 There are common interrupt_init() and timer_interrupt()
3807 for all PPC archs. interrupt_init() calls interrupt_init_cpu()
3808 for CPU specific initialization. interrupt_init_cpu()
3809 should set decrementer_count to appropriate value. If
3810 CPU resets decrementer automatically after interrupt
3811 (ppc4xx) it should set decrementer_count to zero.
3812 timer_interrupt() calls timer_interrupt_cpu() for CPU
3813 specific handling. If board has watchdog / status_led
3814 / other_activity_monitor it works automatically from
3815 general timer_interrupt().
3819 In the target system modem support is enabled when a
3820 specific key (key combination) is pressed during
3821 power-on. Otherwise U-Boot will boot normally
3822 (autoboot). The key_pressed() function is called from
3823 board_init(). Currently key_pressed() is a dummy
3824 function, returning 1 and thus enabling modem
3827 If there are no modem init strings in the
3828 environment, U-Boot proceed to autoboot; the
3829 previous output (banner, info printfs) will be
3832 See also: doc/README.Modem
3834 Board initialization settings:
3835 ------------------------------
3837 During Initialization u-boot calls a number of board specific functions
3838 to allow the preparation of board specific prerequisites, e.g. pin setup
3839 before drivers are initialized. To enable these callbacks the
3840 following configuration macros have to be defined. Currently this is
3841 architecture specific, so please check arch/your_architecture/lib/board.c
3842 typically in board_init_f() and board_init_r().
3844 - CONFIG_BOARD_EARLY_INIT_F: Call board_early_init_f()
3845 - CONFIG_BOARD_EARLY_INIT_R: Call board_early_init_r()
3846 - CONFIG_BOARD_LATE_INIT: Call board_late_init()
3847 - CONFIG_BOARD_POSTCLK_INIT: Call board_postclk_init()
3849 Configuration Settings:
3850 -----------------------
3852 - CONFIG_SYS_SUPPORT_64BIT_DATA: Defined automatically if compiled as 64-bit.
3853 Optionally it can be defined to support 64-bit memory commands.
3855 - CONFIG_SYS_LONGHELP: Defined when you want long help messages included;
3856 undefine this when you're short of memory.
3858 - CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default
3859 width of the commands listed in the 'help' command output.
3861 - CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to
3862 prompt for user input.
3864 - CONFIG_SYS_CBSIZE: Buffer size for input from the Console
3866 - CONFIG_SYS_PBSIZE: Buffer size for Console output
3868 - CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands
3870 - CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to
3871 the application (usually a Linux kernel) when it is
3874 - CONFIG_SYS_BAUDRATE_TABLE:
3875 List of legal baudrate settings for this board.
3877 - CONFIG_SYS_CONSOLE_INFO_QUIET
3878 Suppress display of console information at boot.
3880 - CONFIG_SYS_CONSOLE_IS_IN_ENV
3881 If the board specific function
3882 extern int overwrite_console (void);
3883 returns 1, the stdin, stderr and stdout are switched to the
3884 serial port, else the settings in the environment are used.
3886 - CONFIG_SYS_CONSOLE_OVERWRITE_ROUTINE
3887 Enable the call to overwrite_console().
3889 - CONFIG_SYS_CONSOLE_ENV_OVERWRITE
3890 Enable overwrite of previous console environment settings.
3892 - CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END:
3893 Begin and End addresses of the area used by the
3896 - CONFIG_SYS_ALT_MEMTEST:
3897 Enable an alternate, more extensive memory test.
3899 - CONFIG_SYS_MEMTEST_SCRATCH:
3900 Scratch address used by the alternate memory test
3901 You only need to set this if address zero isn't writeable
3903 - CONFIG_SYS_MEM_TOP_HIDE (PPC only):
3904 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header,
3905 this specified memory area will get subtracted from the top
3906 (end) of RAM and won't get "touched" at all by U-Boot. By
3907 fixing up gd->ram_size the Linux kernel should gets passed
3908 the now "corrected" memory size and won't touch it either.
3909 This should work for arch/ppc and arch/powerpc. Only Linux
3910 board ports in arch/powerpc with bootwrapper support that
3911 recalculate the memory size from the SDRAM controller setup
3912 will have to get fixed in Linux additionally.
3914 This option can be used as a workaround for the 440EPx/GRx
3915 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't
3918 WARNING: Please make sure that this value is a multiple of
3919 the Linux page size (normally 4k). If this is not the case,
3920 then the end address of the Linux memory will be located at a
3921 non page size aligned address and this could cause major
3924 - CONFIG_SYS_LOADS_BAUD_CHANGE:
3925 Enable temporary baudrate change while serial download
3927 - CONFIG_SYS_SDRAM_BASE:
3928 Physical start address of SDRAM. _Must_ be 0 here.
3930 - CONFIG_SYS_MBIO_BASE:
3931 Physical start address of Motherboard I/O (if using a
3934 - CONFIG_SYS_FLASH_BASE:
3935 Physical start address of Flash memory.
3937 - CONFIG_SYS_MONITOR_BASE:
3938 Physical start address of boot monitor code (set by
3939 make config files to be same as the text base address
3940 (CONFIG_SYS_TEXT_BASE) used when linking) - same as
3941 CONFIG_SYS_FLASH_BASE when booting from flash.
3943 - CONFIG_SYS_MONITOR_LEN:
3944 Size of memory reserved for monitor code, used to
3945 determine _at_compile_time_ (!) if the environment is
3946 embedded within the U-Boot image, or in a separate
3949 - CONFIG_SYS_MALLOC_LEN:
3950 Size of DRAM reserved for malloc() use.
3952 - CONFIG_SYS_MALLOC_F_LEN
3953 Size of the malloc() pool for use before relocation. If
3954 this is defined, then a very simple malloc() implementation
3955 will become available before relocation. The address is just
3956 below the global data, and the stack is moved down to make
3959 This feature allocates regions with increasing addresses
3960 within the region. calloc() is supported, but realloc()
3961 is not available. free() is supported but does nothing.
3962 The memory will be freed (or in fact just forgotten) when
3963 U-Boot relocates itself.
3965 Pre-relocation malloc() is only supported on ARM and sandbox
3966 at present but is fairly easy to enable for other archs.
3968 - CONFIG_SYS_MALLOC_SIMPLE
3969 Provides a simple and small malloc() and calloc() for those
3970 boards which do not use the full malloc in SPL (which is
3971 enabled with CONFIG_SYS_SPL_MALLOC_START).
3973 - CONFIG_SYS_NONCACHED_MEMORY:
3974 Size of non-cached memory area. This area of memory will be
3975 typically located right below the malloc() area and mapped
3976 uncached in the MMU. This is useful for drivers that would
3977 otherwise require a lot of explicit cache maintenance. For
3978 some drivers it's also impossible to properly maintain the
3979 cache. For example if the regions that need to be flushed
3980 are not a multiple of the cache-line size, *and* padding
3981 cannot be allocated between the regions to align them (i.e.
3982 if the HW requires a contiguous array of regions, and the
3983 size of each region is not cache-aligned), then a flush of
3984 one region may result in overwriting data that hardware has
3985 written to another region in the same cache-line. This can
3986 happen for example in network drivers where descriptors for
3987 buffers are typically smaller than the CPU cache-line (e.g.
3988 16 bytes vs. 32 or 64 bytes).
3990 Non-cached memory is only supported on 32-bit ARM at present.
3992 - CONFIG_SYS_BOOTM_LEN:
3993 Normally compressed uImages are limited to an
3994 uncompressed size of 8 MBytes. If this is not enough,
3995 you can define CONFIG_SYS_BOOTM_LEN in your board config file
3996 to adjust this setting to your needs.
3998 - CONFIG_SYS_BOOTMAPSZ:
3999 Maximum size of memory mapped by the startup code of
4000 the Linux kernel; all data that must be processed by
4001 the Linux kernel (bd_info, boot arguments, FDT blob if
4002 used) must be put below this limit, unless "bootm_low"
4003 environment variable is defined and non-zero. In such case
4004 all data for the Linux kernel must be between "bootm_low"
4005 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ. The environment
4006 variable "bootm_mapsize" will override the value of
4007 CONFIG_SYS_BOOTMAPSZ. If CONFIG_SYS_BOOTMAPSZ is undefined,
4008 then the value in "bootm_size" will be used instead.
4010 - CONFIG_SYS_BOOT_RAMDISK_HIGH:
4011 Enable initrd_high functionality. If defined then the
4012 initrd_high feature is enabled and the bootm ramdisk subcommand
4015 - CONFIG_SYS_BOOT_GET_CMDLINE:
4016 Enables allocating and saving kernel cmdline in space between
4017 "bootm_low" and "bootm_low" + BOOTMAPSZ.
4019 - CONFIG_SYS_BOOT_GET_KBD:
4020 Enables allocating and saving a kernel copy of the bd_info in
4021 space between "bootm_low" and "bootm_low" + BOOTMAPSZ.
4023 - CONFIG_SYS_MAX_FLASH_BANKS:
4024 Max number of Flash memory banks
4026 - CONFIG_SYS_MAX_FLASH_SECT:
4027 Max number of sectors on a Flash chip
4029 - CONFIG_SYS_FLASH_ERASE_TOUT:
4030 Timeout for Flash erase operations (in ms)
4032 - CONFIG_SYS_FLASH_WRITE_TOUT:
4033 Timeout for Flash write operations (in ms)
4035 - CONFIG_SYS_FLASH_LOCK_TOUT
4036 Timeout for Flash set sector lock bit operation (in ms)
4038 - CONFIG_SYS_FLASH_UNLOCK_TOUT
4039 Timeout for Flash clear lock bits operation (in ms)
4041 - CONFIG_SYS_FLASH_PROTECTION
4042 If defined, hardware flash sectors protection is used
4043 instead of U-Boot software protection.
4045 - CONFIG_SYS_DIRECT_FLASH_TFTP:
4047 Enable TFTP transfers directly to flash memory;
4048 without this option such a download has to be
4049 performed in two steps: (1) download to RAM, and (2)
4050 copy from RAM to flash.
4052 The two-step approach is usually more reliable, since
4053 you can check if the download worked before you erase
4054 the flash, but in some situations (when system RAM is
4055 too limited to allow for a temporary copy of the
4056 downloaded image) this option may be very useful.
4058 - CONFIG_SYS_FLASH_CFI:
4059 Define if the flash driver uses extra elements in the
4060 common flash structure for storing flash geometry.
4062 - CONFIG_FLASH_CFI_DRIVER
4063 This option also enables the building of the cfi_flash driver
4064 in the drivers directory
4066 - CONFIG_FLASH_CFI_MTD
4067 This option enables the building of the cfi_mtd driver
4068 in the drivers directory. The driver exports CFI flash
4071 - CONFIG_SYS_FLASH_USE_BUFFER_WRITE
4072 Use buffered writes to flash.
4074 - CONFIG_FLASH_SPANSION_S29WS_N
4075 s29ws-n MirrorBit flash has non-standard addresses for buffered
4078 - CONFIG_SYS_FLASH_QUIET_TEST
4079 If this option is defined, the common CFI flash doesn't
4080 print it's warning upon not recognized FLASH banks. This
4081 is useful, if some of the configured banks are only
4082 optionally available.
4084 - CONFIG_FLASH_SHOW_PROGRESS
4085 If defined (must be an integer), print out countdown
4086 digits and dots. Recommended value: 45 (9..1) for 80
4087 column displays, 15 (3..1) for 40 column displays.
4089 - CONFIG_FLASH_VERIFY
4090 If defined, the content of the flash (destination) is compared
4091 against the source after the write operation. An error message
4092 will be printed when the contents are not identical.
4093 Please note that this option is useless in nearly all cases,
4094 since such flash programming errors usually are detected earlier
4095 while unprotecting/erasing/programming. Please only enable
4096 this option if you really know what you are doing.
4098 - CONFIG_SYS_RX_ETH_BUFFER:
4099 Defines the number of Ethernet receive buffers. On some
4100 Ethernet controllers it is recommended to set this value
4101 to 8 or even higher (EEPRO100 or 405 EMAC), since all
4102 buffers can be full shortly after enabling the interface
4103 on high Ethernet traffic.
4104 Defaults to 4 if not defined.
4106 - CONFIG_ENV_MAX_ENTRIES
4108 Maximum number of entries in the hash table that is used
4109 internally to store the environment settings. The default
4110 setting is supposed to be generous and should work in most
4111 cases. This setting can be used to tune behaviour; see
4112 lib/hashtable.c for details.
4114 - CONFIG_ENV_FLAGS_LIST_DEFAULT
4115 - CONFIG_ENV_FLAGS_LIST_STATIC
4116 Enable validation of the values given to environment variables when
4117 calling env set. Variables can be restricted to only decimal,
4118 hexadecimal, or boolean. If CONFIG_CMD_NET is also defined,
4119 the variables can also be restricted to IP address or MAC address.
4121 The format of the list is:
4122 type_attribute = [s|d|x|b|i|m]
4123 access_attribute = [a|r|o|c]
4124 attributes = type_attribute[access_attribute]
4125 entry = variable_name[:attributes]
4128 The type attributes are:
4129 s - String (default)
4132 b - Boolean ([1yYtT|0nNfF])
4136 The access attributes are:
4142 - CONFIG_ENV_FLAGS_LIST_DEFAULT
4143 Define this to a list (string) to define the ".flags"
4144 environment variable in the default or embedded environment.
4146 - CONFIG_ENV_FLAGS_LIST_STATIC
4147 Define this to a list (string) to define validation that
4148 should be done if an entry is not found in the ".flags"
4149 environment variable. To override a setting in the static
4150 list, simply add an entry for the same variable name to the
4153 If CONFIG_REGEX is defined, the variable_name above is evaluated as a
4154 regular expression. This allows multiple variables to define the same
4155 flags without explicitly listing them for each variable.
4157 - CONFIG_ENV_ACCESS_IGNORE_FORCE
4158 If defined, don't allow the -f switch to env set override variable
4161 - CONFIG_SYS_GENERIC_BOARD
4162 This selects the architecture-generic board system instead of the
4163 architecture-specific board files. It is intended to move boards
4164 to this new framework over time. Defining this will disable the
4165 arch/foo/lib/board.c file and use common/board_f.c and
4166 common/board_r.c instead. To use this option your architecture
4167 must support it (i.e. must select HAVE_GENERIC_BOARD in arch/Kconfig).
4168 If you find problems enabling this option on your board please report
4169 the problem and send patches!
4171 - CONFIG_OMAP_PLATFORM_RESET_TIME_MAX_USEC (OMAP only)
4172 This is set by OMAP boards for the max time that reset should
4173 be asserted. See doc/README.omap-reset-time for details on how
4174 the value can be calculated on a given board.
4177 If stdint.h is available with your toolchain you can define this
4178 option to enable it. You can provide option 'USE_STDINT=1' when
4179 building U-Boot to enable this.
4181 The following definitions that deal with the placement and management
4182 of environment data (variable area); in general, we support the
4183 following configurations:
4185 - CONFIG_BUILD_ENVCRC:
4187 Builds up envcrc with the target environment so that external utils
4188 may easily extract it and embed it in final U-Boot images.
4190 - CONFIG_ENV_IS_IN_FLASH:
4192 Define this if the environment is in flash memory.
4194 a) The environment occupies one whole flash sector, which is
4195 "embedded" in the text segment with the U-Boot code. This
4196 happens usually with "bottom boot sector" or "top boot
4197 sector" type flash chips, which have several smaller
4198 sectors at the start or the end. For instance, such a
4199 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In
4200 such a case you would place the environment in one of the
4201 4 kB sectors - with U-Boot code before and after it. With
4202 "top boot sector" type flash chips, you would put the
4203 environment in one of the last sectors, leaving a gap
4204 between U-Boot and the environment.
4206 - CONFIG_ENV_OFFSET:
4208 Offset of environment data (variable area) to the
4209 beginning of flash memory; for instance, with bottom boot
4210 type flash chips the second sector can be used: the offset
4211 for this sector is given here.
4213 CONFIG_ENV_OFFSET is used relative to CONFIG_SYS_FLASH_BASE.
4217 This is just another way to specify the start address of
4218 the flash sector containing the environment (instead of
4221 - CONFIG_ENV_SECT_SIZE:
4223 Size of the sector containing the environment.
4226 b) Sometimes flash chips have few, equal sized, BIG sectors.
4227 In such a case you don't want to spend a whole sector for
4232 If you use this in combination with CONFIG_ENV_IS_IN_FLASH
4233 and CONFIG_ENV_SECT_SIZE, you can specify to use only a part
4234 of this flash sector for the environment. This saves
4235 memory for the RAM copy of the environment.
4237 It may also save flash memory if you decide to use this
4238 when your environment is "embedded" within U-Boot code,
4239 since then the remainder of the flash sector could be used
4240 for U-Boot code. It should be pointed out that this is
4241 STRONGLY DISCOURAGED from a robustness point of view:
4242 updating the environment in flash makes it always
4243 necessary to erase the WHOLE sector. If something goes
4244 wrong before the contents has been restored from a copy in
4245 RAM, your target system will be dead.
4247 - CONFIG_ENV_ADDR_REDUND
4248 CONFIG_ENV_SIZE_REDUND
4250 These settings describe a second storage area used to hold
4251 a redundant copy of the environment data, so that there is
4252 a valid backup copy in case there is a power failure during
4253 a "saveenv" operation.
4255 BE CAREFUL! Any changes to the flash layout, and some changes to the
4256 source code will make it necessary to adapt <board>/u-boot.lds*
4260 - CONFIG_ENV_IS_IN_NVRAM:
4262 Define this if you have some non-volatile memory device
4263 (NVRAM, battery buffered SRAM) which you want to use for the
4269 These two #defines are used to determine the memory area you
4270 want to use for environment. It is assumed that this memory
4271 can just be read and written to, without any special
4274 BE CAREFUL! The first access to the environment happens quite early
4275 in U-Boot initialization (when we try to get the setting of for the
4276 console baudrate). You *MUST* have mapped your NVRAM area then, or
4279 Please note that even with NVRAM we still use a copy of the
4280 environment in RAM: we could work on NVRAM directly, but we want to
4281 keep settings there always unmodified except somebody uses "saveenv"
4282 to save the current settings.
4285 - CONFIG_ENV_IS_IN_EEPROM:
4287 Use this if you have an EEPROM or similar serial access
4288 device and a driver for it.
4290 - CONFIG_ENV_OFFSET:
4293 These two #defines specify the offset and size of the
4294 environment area within the total memory of your EEPROM.
4296 - CONFIG_SYS_I2C_EEPROM_ADDR:
4297 If defined, specified the chip address of the EEPROM device.
4298 The default address is zero.
4300 - CONFIG_SYS_I2C_EEPROM_BUS:
4301 If defined, specified the i2c bus of the EEPROM device.
4303 - CONFIG_SYS_EEPROM_PAGE_WRITE_BITS:
4304 If defined, the number of bits used to address bytes in a
4305 single page in the EEPROM device. A 64 byte page, for example
4306 would require six bits.
4308 - CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS:
4309 If defined, the number of milliseconds to delay between
4310 page writes. The default is zero milliseconds.
4312 - CONFIG_SYS_I2C_EEPROM_ADDR_LEN:
4313 The length in bytes of the EEPROM memory array address. Note
4314 that this is NOT the chip address length!
4316 - CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW:
4317 EEPROM chips that implement "address overflow" are ones
4318 like Catalyst 24WC04/08/16 which has 9/10/11 bits of
4319 address and the extra bits end up in the "chip address" bit
4320 slots. This makes a 24WC08 (1Kbyte) chip look like four 256
4323 Note that we consider the length of the address field to
4324 still be one byte because the extra address bits are hidden
4325 in the chip address.
4327 - CONFIG_SYS_EEPROM_SIZE:
4328 The size in bytes of the EEPROM device.
4330 - CONFIG_ENV_EEPROM_IS_ON_I2C
4331 define this, if you have I2C and SPI activated, and your
4332 EEPROM, which holds the environment, is on the I2C bus.
4334 - CONFIG_I2C_ENV_EEPROM_BUS
4335 if you have an Environment on an EEPROM reached over
4336 I2C muxes, you can define here, how to reach this
4337 EEPROM. For example:
4339 #define CONFIG_I2C_ENV_EEPROM_BUS 1
4341 EEPROM which holds the environment, is reached over
4342 a pca9547 i2c mux with address 0x70, channel 3.
4344 - CONFIG_ENV_IS_IN_DATAFLASH:
4346 Define this if you have a DataFlash memory device which you
4347 want to use for the environment.
4349 - CONFIG_ENV_OFFSET:
4353 These three #defines specify the offset and size of the
4354 environment area within the total memory of your DataFlash placed
4355 at the specified address.
4357 - CONFIG_ENV_IS_IN_SPI_FLASH:
4359 Define this if you have a SPI Flash memory device which you
4360 want to use for the environment.
4362 - CONFIG_ENV_OFFSET:
4365 These two #defines specify the offset and size of the
4366 environment area within the SPI Flash. CONFIG_ENV_OFFSET must be
4367 aligned to an erase sector boundary.
4369 - CONFIG_ENV_SECT_SIZE:
4371 Define the SPI flash's sector size.
4373 - CONFIG_ENV_OFFSET_REDUND (optional):
4375 This setting describes a second storage area of CONFIG_ENV_SIZE
4376 size used to hold a redundant copy of the environment data, so
4377 that there is a valid backup copy in case there is a power failure
4378 during a "saveenv" operation. CONFIG_ENV_OFFSET_RENDUND must be
4379 aligned to an erase sector boundary.
4381 - CONFIG_ENV_SPI_BUS (optional):
4382 - CONFIG_ENV_SPI_CS (optional):
4384 Define the SPI bus and chip select. If not defined they will be 0.
4386 - CONFIG_ENV_SPI_MAX_HZ (optional):
4388 Define the SPI max work clock. If not defined then use 1MHz.
4390 - CONFIG_ENV_SPI_MODE (optional):
4392 Define the SPI work mode. If not defined then use SPI_MODE_3.
4394 - CONFIG_ENV_IS_IN_REMOTE:
4396 Define this if you have a remote memory space which you
4397 want to use for the local device's environment.
4402 These two #defines specify the address and size of the
4403 environment area within the remote memory space. The
4404 local device can get the environment from remote memory
4405 space by SRIO or PCIE links.
4407 BE CAREFUL! For some special cases, the local device can not use
4408 "saveenv" command. For example, the local device will get the
4409 environment stored in a remote NOR flash by SRIO or PCIE link,
4410 but it can not erase, write this NOR flash by SRIO or PCIE interface.
4412 - CONFIG_ENV_IS_IN_NAND:
4414 Define this if you have a NAND device which you want to use
4415 for the environment.
4417 - CONFIG_ENV_OFFSET:
4420 These two #defines specify the offset and size of the environment
4421 area within the first NAND device. CONFIG_ENV_OFFSET must be
4422 aligned to an erase block boundary.
4424 - CONFIG_ENV_OFFSET_REDUND (optional):
4426 This setting describes a second storage area of CONFIG_ENV_SIZE
4427 size used to hold a redundant copy of the environment data, so
4428 that there is a valid backup copy in case there is a power failure
4429 during a "saveenv" operation. CONFIG_ENV_OFFSET_RENDUND must be
4430 aligned to an erase block boundary.
4432 - CONFIG_ENV_RANGE (optional):
4434 Specifies the length of the region in which the environment
4435 can be written. This should be a multiple of the NAND device's
4436 block size. Specifying a range with more erase blocks than
4437 are needed to hold CONFIG_ENV_SIZE allows bad blocks within
4438 the range to be avoided.
4440 - CONFIG_ENV_OFFSET_OOB (optional):
4442 Enables support for dynamically retrieving the offset of the
4443 environment from block zero's out-of-band data. The
4444 "nand env.oob" command can be used to record this offset.
4445 Currently, CONFIG_ENV_OFFSET_REDUND is not supported when
4446 using CONFIG_ENV_OFFSET_OOB.
4448 - CONFIG_NAND_ENV_DST
4450 Defines address in RAM to which the nand_spl code should copy the
4451 environment. If redundant environment is used, it will be copied to
4452 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE.
4454 - CONFIG_ENV_IS_IN_UBI:
4456 Define this if you have an UBI volume that you want to use for the
4457 environment. This has the benefit of wear-leveling the environment
4458 accesses, which is important on NAND.
4460 - CONFIG_ENV_UBI_PART:
4462 Define this to a string that is the mtd partition containing the UBI.
4464 - CONFIG_ENV_UBI_VOLUME:
4466 Define this to the name of the volume that you want to store the
4469 - CONFIG_ENV_UBI_VOLUME_REDUND:
4471 Define this to the name of another volume to store a second copy of
4472 the environment in. This will enable redundant environments in UBI.
4473 It is assumed that both volumes are in the same MTD partition.
4475 - CONFIG_UBI_SILENCE_MSG
4476 - CONFIG_UBIFS_SILENCE_MSG
4478 You will probably want to define these to avoid a really noisy system
4479 when storing the env in UBI.
4481 - CONFIG_ENV_IS_IN_FAT:
4482 Define this if you want to use the FAT file system for the environment.
4484 - FAT_ENV_INTERFACE:
4486 Define this to a string that is the name of the block device.
4488 - FAT_ENV_DEV_AND_PART:
4490 Define this to a string to specify the partition of the device. It can
4493 "D:P", "D:0", "D", "D:" or "D:auto" (D, P are integers. And P >= 1)
4494 - "D:P": device D partition P. Error occurs if device D has no
4497 - "D" or "D:": device D partition 1 if device D has partition
4498 table, or the whole device D if has no partition
4500 - "D:auto": first partition in device D with bootable flag set.
4501 If none, first valid partition in device D. If no
4502 partition table then means device D.
4506 It's a string of the FAT file name. This file use to store the
4510 This should be defined. Otherwise it cannot save the environment file.
4512 - CONFIG_ENV_IS_IN_MMC:
4514 Define this if you have an MMC device which you want to use for the
4517 - CONFIG_SYS_MMC_ENV_DEV:
4519 Specifies which MMC device the environment is stored in.
4521 - CONFIG_SYS_MMC_ENV_PART (optional):
4523 Specifies which MMC partition the environment is stored in. If not
4524 set, defaults to partition 0, the user area. Common values might be
4525 1 (first MMC boot partition), 2 (second MMC boot partition).
4527 - CONFIG_ENV_OFFSET:
4530 These two #defines specify the offset and size of the environment
4531 area within the specified MMC device.
4533 If offset is positive (the usual case), it is treated as relative to
4534 the start of the MMC partition. If offset is negative, it is treated
4535 as relative to the end of the MMC partition. This can be useful if
4536 your board may be fitted with different MMC devices, which have
4537 different sizes for the MMC partitions, and you always want the
4538 environment placed at the very end of the partition, to leave the
4539 maximum possible space before it, to store other data.
4541 These two values are in units of bytes, but must be aligned to an
4542 MMC sector boundary.
4544 - CONFIG_ENV_OFFSET_REDUND (optional):
4546 Specifies a second storage area, of CONFIG_ENV_SIZE size, used to
4547 hold a redundant copy of the environment data. This provides a
4548 valid backup copy in case the other copy is corrupted, e.g. due
4549 to a power failure during a "saveenv" operation.
4551 This value may also be positive or negative; this is handled in the
4552 same way as CONFIG_ENV_OFFSET.
4554 This value is also in units of bytes, but must also be aligned to
4555 an MMC sector boundary.
4557 - CONFIG_ENV_SIZE_REDUND (optional):
4559 This value need not be set, even when CONFIG_ENV_OFFSET_REDUND is
4560 set. If this value is set, it must be set to the same value as
4563 - CONFIG_SYS_SPI_INIT_OFFSET
4565 Defines offset to the initial SPI buffer area in DPRAM. The
4566 area is used at an early stage (ROM part) if the environment
4567 is configured to reside in the SPI EEPROM: We need a 520 byte
4568 scratch DPRAM area. It is used between the two initialization
4569 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems
4570 to be a good choice since it makes it far enough from the
4571 start of the data area as well as from the stack pointer.
4573 Please note that the environment is read-only until the monitor
4574 has been relocated to RAM and a RAM copy of the environment has been
4575 created; also, when using EEPROM you will have to use getenv_f()
4576 until then to read environment variables.
4578 The environment is protected by a CRC32 checksum. Before the monitor
4579 is relocated into RAM, as a result of a bad CRC you will be working
4580 with the compiled-in default environment - *silently*!!! [This is
4581 necessary, because the first environment variable we need is the
4582 "baudrate" setting for the console - if we have a bad CRC, we don't
4583 have any device yet where we could complain.]
4585 Note: once the monitor has been relocated, then it will complain if
4586 the default environment is used; a new CRC is computed as soon as you
4587 use the "saveenv" command to store a valid environment.
4589 - CONFIG_SYS_FAULT_ECHO_LINK_DOWN:
4590 Echo the inverted Ethernet link state to the fault LED.
4592 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR
4593 also needs to be defined.
4595 - CONFIG_SYS_FAULT_MII_ADDR:
4596 MII address of the PHY to check for the Ethernet link state.
4598 - CONFIG_NS16550_MIN_FUNCTIONS:
4599 Define this if you desire to only have use of the NS16550_init
4600 and NS16550_putc functions for the serial driver located at
4601 drivers/serial/ns16550.c. This option is useful for saving
4602 space for already greatly restricted images, including but not
4603 limited to NAND_SPL configurations.
4605 - CONFIG_DISPLAY_BOARDINFO
4606 Display information about the board that U-Boot is running on
4607 when U-Boot starts up. The board function checkboard() is called
4610 - CONFIG_DISPLAY_BOARDINFO_LATE
4611 Similar to the previous option, but display this information
4612 later, once stdio is running and output goes to the LCD, if
4615 - CONFIG_BOARD_SIZE_LIMIT:
4616 Maximum size of the U-Boot image. When defined, the
4617 build system checks that the actual size does not
4620 Low Level (hardware related) configuration options:
4621 ---------------------------------------------------
4623 - CONFIG_SYS_CACHELINE_SIZE:
4624 Cache Line Size of the CPU.
4626 - CONFIG_SYS_DEFAULT_IMMR:
4627 Default address of the IMMR after system reset.
4629 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU,
4630 and RPXsuper) to be able to adjust the position of
4631 the IMMR register after a reset.
4633 - CONFIG_SYS_CCSRBAR_DEFAULT:
4634 Default (power-on reset) physical address of CCSR on Freescale
4637 - CONFIG_SYS_CCSRBAR:
4638 Virtual address of CCSR. On a 32-bit build, this is typically
4639 the same value as CONFIG_SYS_CCSRBAR_DEFAULT.
4641 CONFIG_SYS_DEFAULT_IMMR must also be set to this value,
4642 for cross-platform code that uses that macro instead.
4644 - CONFIG_SYS_CCSRBAR_PHYS:
4645 Physical address of CCSR. CCSR can be relocated to a new
4646 physical address, if desired. In this case, this macro should
4647 be set to that address. Otherwise, it should be set to the
4648 same value as CONFIG_SYS_CCSRBAR_DEFAULT. For example, CCSR
4649 is typically relocated on 36-bit builds. It is recommended
4650 that this macro be defined via the _HIGH and _LOW macros:
4652 #define CONFIG_SYS_CCSRBAR_PHYS ((CONFIG_SYS_CCSRBAR_PHYS_HIGH
4653 * 1ull) << 32 | CONFIG_SYS_CCSRBAR_PHYS_LOW)
4655 - CONFIG_SYS_CCSRBAR_PHYS_HIGH:
4656 Bits 33-36 of CONFIG_SYS_CCSRBAR_PHYS. This value is typically
4657 either 0 (32-bit build) or 0xF (36-bit build). This macro is
4658 used in assembly code, so it must not contain typecasts or
4659 integer size suffixes (e.g. "ULL").
4661 - CONFIG_SYS_CCSRBAR_PHYS_LOW:
4662 Lower 32-bits of CONFIG_SYS_CCSRBAR_PHYS. This macro is
4663 used in assembly code, so it must not contain typecasts or
4664 integer size suffixes (e.g. "ULL").
4666 - CONFIG_SYS_CCSR_DO_NOT_RELOCATE:
4667 If this macro is defined, then CONFIG_SYS_CCSRBAR_PHYS will be
4668 forced to a value that ensures that CCSR is not relocated.
4670 - Floppy Disk Support:
4671 CONFIG_SYS_FDC_DRIVE_NUMBER
4673 the default drive number (default value 0)
4675 CONFIG_SYS_ISA_IO_STRIDE
4677 defines the spacing between FDC chipset registers
4680 CONFIG_SYS_ISA_IO_OFFSET
4682 defines the offset of register from address. It
4683 depends on which part of the data bus is connected to
4684 the FDC chipset. (default value 0)
4686 If CONFIG_SYS_ISA_IO_STRIDE CONFIG_SYS_ISA_IO_OFFSET and
4687 CONFIG_SYS_FDC_DRIVE_NUMBER are undefined, they take their
4690 if CONFIG_SYS_FDC_HW_INIT is defined, then the function
4691 fdc_hw_init() is called at the beginning of the FDC
4692 setup. fdc_hw_init() must be provided by the board
4693 source code. It is used to make hardware-dependent
4697 Most IDE controllers were designed to be connected with PCI
4698 interface. Only few of them were designed for AHB interface.
4699 When software is doing ATA command and data transfer to
4700 IDE devices through IDE-AHB controller, some additional
4701 registers accessing to these kind of IDE-AHB controller
4704 - CONFIG_SYS_IMMR: Physical address of the Internal Memory.
4705 DO NOT CHANGE unless you know exactly what you're
4706 doing! (11-4) [MPC8xx/82xx systems only]
4708 - CONFIG_SYS_INIT_RAM_ADDR:
4710 Start address of memory area that can be used for
4711 initial data and stack; please note that this must be
4712 writable memory that is working WITHOUT special
4713 initialization, i. e. you CANNOT use normal RAM which
4714 will become available only after programming the
4715 memory controller and running certain initialization
4718 U-Boot uses the following memory types:
4719 - MPC8xx and MPC8260: IMMR (internal memory of the CPU)
4720 - MPC824X: data cache
4721 - PPC4xx: data cache
4723 - CONFIG_SYS_GBL_DATA_OFFSET:
4725 Offset of the initial data structure in the memory
4726 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually
4727 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial
4728 data is located at the end of the available space
4729 (sometimes written as (CONFIG_SYS_INIT_RAM_SIZE -
4730 CONFIG_SYS_INIT_DATA_SIZE), and the initial stack is just
4731 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR +
4732 CONFIG_SYS_GBL_DATA_OFFSET) downward.
4735 On the MPC824X (or other systems that use the data
4736 cache for initial memory) the address chosen for
4737 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must
4738 point to an otherwise UNUSED address space between
4739 the top of RAM and the start of the PCI space.
4741 - CONFIG_SYS_SIUMCR: SIU Module Configuration (11-6)
4743 - CONFIG_SYS_SYPCR: System Protection Control (11-9)
4745 - CONFIG_SYS_TBSCR: Time Base Status and Control (11-26)
4747 - CONFIG_SYS_PISCR: Periodic Interrupt Status and Control (11-31)
4749 - CONFIG_SYS_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30)
4751 - CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27)
4753 - CONFIG_SYS_OR_TIMING_SDRAM:
4756 - CONFIG_SYS_MAMR_PTA:
4757 periodic timer for refresh
4759 - CONFIG_SYS_DER: Debug Event Register (37-47)
4761 - FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM,
4762 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP,
4763 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM,
4764 CONFIG_SYS_BR1_PRELIM:
4765 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
4767 - SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
4768 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM,
4769 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM:
4770 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
4772 - CONFIG_SYS_MAMR_PTA, CONFIG_SYS_MPTPR_2BK_4K, CONFIG_SYS_MPTPR_1BK_4K, CONFIG_SYS_MPTPR_2BK_8K,
4773 CONFIG_SYS_MPTPR_1BK_8K, CONFIG_SYS_MAMR_8COL, CONFIG_SYS_MAMR_9COL:
4774 Machine Mode Register and Memory Periodic Timer
4775 Prescaler definitions (SDRAM timing)
4777 - CONFIG_SYS_I2C_UCODE_PATCH, CONFIG_SYS_I2C_DPMEM_OFFSET [0x1FC0]:
4778 enable I2C microcode relocation patch (MPC8xx);
4779 define relocation offset in DPRAM [DSP2]
4781 - CONFIG_SYS_SMC_UCODE_PATCH, CONFIG_SYS_SMC_DPMEM_OFFSET [0x1FC0]:
4782 enable SMC microcode relocation patch (MPC8xx);
4783 define relocation offset in DPRAM [SMC1]
4785 - CONFIG_SYS_SPI_UCODE_PATCH, CONFIG_SYS_SPI_DPMEM_OFFSET [0x1FC0]:
4786 enable SPI microcode relocation patch (MPC8xx);
4787 define relocation offset in DPRAM [SCC4]
4789 - CONFIG_SYS_USE_OSCCLK:
4790 Use OSCM clock mode on MBX8xx board. Be careful,
4791 wrong setting might damage your board. Read
4792 doc/README.MBX before setting this variable!
4794 - CONFIG_SYS_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only)
4795 Offset of the bootmode word in DPRAM used by post
4796 (Power On Self Tests). This definition overrides
4797 #define'd default value in commproc.h resp.
4800 - CONFIG_SYS_PCI_SLV_MEM_LOCAL, CONFIG_SYS_PCI_SLV_MEM_BUS, CONFIG_SYS_PICMR0_MASK_ATTRIB,
4801 CONFIG_SYS_PCI_MSTR0_LOCAL, CONFIG_SYS_PCIMSK0_MASK, CONFIG_SYS_PCI_MSTR1_LOCAL,
4802 CONFIG_SYS_PCIMSK1_MASK, CONFIG_SYS_PCI_MSTR_MEM_LOCAL, CONFIG_SYS_PCI_MSTR_MEM_BUS,
4803 CONFIG_SYS_CPU_PCI_MEM_START, CONFIG_SYS_PCI_MSTR_MEM_SIZE, CONFIG_SYS_POCMR0_MASK_ATTRIB,
4804 CONFIG_SYS_PCI_MSTR_MEMIO_LOCAL, CONFIG_SYS_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START,
4805 CONFIG_SYS_PCI_MSTR_MEMIO_SIZE, CONFIG_SYS_POCMR1_MASK_ATTRIB, CONFIG_SYS_PCI_MSTR_IO_LOCAL,
4806 CONFIG_SYS_PCI_MSTR_IO_BUS, CONFIG_SYS_CPU_PCI_IO_START, CONFIG_SYS_PCI_MSTR_IO_SIZE,
4807 CONFIG_SYS_POCMR2_MASK_ATTRIB: (MPC826x only)
4808 Overrides the default PCI memory map in arch/powerpc/cpu/mpc8260/pci.c if set.
4810 - CONFIG_PCI_DISABLE_PCIE:
4811 Disable PCI-Express on systems where it is supported but not
4814 - CONFIG_PCI_ENUM_ONLY
4815 Only scan through and get the devices on the buses.
4816 Don't do any setup work, presumably because someone or
4817 something has already done it, and we don't need to do it
4818 a second time. Useful for platforms that are pre-booted
4819 by coreboot or similar.
4821 - CONFIG_PCI_INDIRECT_BRIDGE:
4822 Enable support for indirect PCI bridges.
4825 Chip has SRIO or not
4828 Board has SRIO 1 port available
4831 Board has SRIO 2 port available
4833 - CONFIG_SRIO_PCIE_BOOT_MASTER
4834 Board can support master function for Boot from SRIO and PCIE
4836 - CONFIG_SYS_SRIOn_MEM_VIRT:
4837 Virtual Address of SRIO port 'n' memory region
4839 - CONFIG_SYS_SRIOn_MEM_PHYS:
4840 Physical Address of SRIO port 'n' memory region
4842 - CONFIG_SYS_SRIOn_MEM_SIZE:
4843 Size of SRIO port 'n' memory region
4845 - CONFIG_SYS_NAND_BUSWIDTH_16BIT
4846 Defined to tell the NAND controller that the NAND chip is using
4848 Not all NAND drivers use this symbol.
4849 Example of drivers that use it:
4850 - drivers/mtd/nand/ndfc.c
4851 - drivers/mtd/nand/mxc_nand.c
4853 - CONFIG_SYS_NDFC_EBC0_CFG
4854 Sets the EBC0_CFG register for the NDFC. If not defined
4855 a default value will be used.
4858 Get DDR timing information from an I2C EEPROM. Common
4859 with pluggable memory modules such as SODIMMs
4862 I2C address of the SPD EEPROM
4864 - CONFIG_SYS_SPD_BUS_NUM
4865 If SPD EEPROM is on an I2C bus other than the first
4866 one, specify here. Note that the value must resolve
4867 to something your driver can deal with.
4869 - CONFIG_SYS_DDR_RAW_TIMING
4870 Get DDR timing information from other than SPD. Common with
4871 soldered DDR chips onboard without SPD. DDR raw timing
4872 parameters are extracted from datasheet and hard-coded into
4873 header files or board specific files.
4875 - CONFIG_FSL_DDR_INTERACTIVE
4876 Enable interactive DDR debugging. See doc/README.fsl-ddr.
4878 - CONFIG_FSL_DDR_SYNC_REFRESH
4879 Enable sync of refresh for multiple controllers.
4881 - CONFIG_FSL_DDR_BIST
4882 Enable built-in memory test for Freescale DDR controllers.
4884 - CONFIG_SYS_83XX_DDR_USES_CS0
4885 Only for 83xx systems. If specified, then DDR should
4886 be configured using CS0 and CS1 instead of CS2 and CS3.
4888 - CONFIG_ETHER_ON_FEC[12]
4889 Define to enable FEC[12] on a 8xx series processor.
4891 - CONFIG_FEC[12]_PHY
4892 Define to the hardcoded PHY address which corresponds
4893 to the given FEC; i. e.
4894 #define CONFIG_FEC1_PHY 4
4895 means that the PHY with address 4 is connected to FEC1
4897 When set to -1, means to probe for first available.
4899 - CONFIG_FEC[12]_PHY_NORXERR
4900 The PHY does not have a RXERR line (RMII only).
4901 (so program the FEC to ignore it).
4904 Enable RMII mode for all FECs.
4905 Note that this is a global option, we can't
4906 have one FEC in standard MII mode and another in RMII mode.
4908 - CONFIG_CRC32_VERIFY
4909 Add a verify option to the crc32 command.
4912 => crc32 -v <address> <count> <crc32>
4914 Where address/count indicate a memory area
4915 and crc32 is the correct crc32 which the
4919 Add the "loopw" memory command. This only takes effect if
4920 the memory commands are activated globally (CONFIG_CMD_MEM).
4923 Add the "mdc" and "mwc" memory commands. These are cyclic
4928 This command will print 4 bytes (10,11,12,13) each 500 ms.
4930 => mwc.l 100 12345678 10
4931 This command will write 12345678 to address 100 all 10 ms.
4933 This only takes effect if the memory commands are activated
4934 globally (CONFIG_CMD_MEM).
4936 - CONFIG_SKIP_LOWLEVEL_INIT
4937 [ARM, NDS32, MIPS only] If this variable is defined, then certain
4938 low level initializations (like setting up the memory
4939 controller) are omitted and/or U-Boot does not
4940 relocate itself into RAM.
4942 Normally this variable MUST NOT be defined. The only
4943 exception is when U-Boot is loaded (to RAM) by some
4944 other boot loader or by a debugger which performs
4945 these initializations itself.
4948 Modifies the behaviour of start.S when compiling a loader
4949 that is executed before the actual U-Boot. E.g. when
4950 compiling a NAND SPL.
4953 Modifies the behaviour of start.S when compiling a loader
4954 that is executed after the SPL and before the actual U-Boot.
4955 It is loaded by the SPL.
4957 - CONFIG_SYS_MPC85XX_NO_RESETVEC
4958 Only for 85xx systems. If this variable is specified, the section
4959 .resetvec is not kept and the section .bootpg is placed in the
4960 previous 4k of the .text section.
4962 - CONFIG_ARCH_MAP_SYSMEM
4963 Generally U-Boot (and in particular the md command) uses
4964 effective address. It is therefore not necessary to regard
4965 U-Boot address as virtual addresses that need to be translated
4966 to physical addresses. However, sandbox requires this, since
4967 it maintains its own little RAM buffer which contains all
4968 addressable memory. This option causes some memory accesses
4969 to be mapped through map_sysmem() / unmap_sysmem().
4971 - CONFIG_USE_ARCH_MEMCPY
4972 CONFIG_USE_ARCH_MEMSET
4973 If these options are used a optimized version of memcpy/memset will
4974 be used if available. These functions may be faster under some
4975 conditions but may increase the binary size.
4977 - CONFIG_X86_RESET_VECTOR
4978 If defined, the x86 reset vector code is included. This is not
4979 needed when U-Boot is running from Coreboot.
4982 Defines the MPU clock speed (in MHz).
4984 NOTE : currently only supported on AM335x platforms.
4986 - CONFIG_SPL_AM33XX_ENABLE_RTC32K_OSC:
4987 Enables the RTC32K OSC on AM33xx based plattforms
4989 - CONFIG_SYS_NAND_NO_SUBPAGE_WRITE
4990 Option to disable subpage write in NAND driver
4991 driver that uses this:
4992 drivers/mtd/nand/davinci_nand.c
4994 Freescale QE/FMAN Firmware Support:
4995 -----------------------------------
4997 The Freescale QUICCEngine (QE) and Frame Manager (FMAN) both support the
4998 loading of "firmware", which is encoded in the QE firmware binary format.
4999 This firmware often needs to be loaded during U-Boot booting, so macros
5000 are used to identify the storage device (NOR flash, SPI, etc) and the address
5003 - CONFIG_SYS_FMAN_FW_ADDR
5004 The address in the storage device where the FMAN microcode is located. The
5005 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
5008 - CONFIG_SYS_QE_FW_ADDR
5009 The address in the storage device where the QE microcode is located. The
5010 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
5013 - CONFIG_SYS_QE_FMAN_FW_LENGTH
5014 The maximum possible size of the firmware. The firmware binary format
5015 has a field that specifies the actual size of the firmware, but it
5016 might not be possible to read any part of the firmware unless some
5017 local storage is allocated to hold the entire firmware first.
5019 - CONFIG_SYS_QE_FMAN_FW_IN_NOR
5020 Specifies that QE/FMAN firmware is located in NOR flash, mapped as
5021 normal addressable memory via the LBC. CONFIG_SYS_FMAN_FW_ADDR is the
5022 virtual address in NOR flash.
5024 - CONFIG_SYS_QE_FMAN_FW_IN_NAND
5025 Specifies that QE/FMAN firmware is located in NAND flash.
5026 CONFIG_SYS_FMAN_FW_ADDR is the offset within NAND flash.
5028 - CONFIG_SYS_QE_FMAN_FW_IN_MMC
5029 Specifies that QE/FMAN firmware is located on the primary SD/MMC
5030 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
5032 - CONFIG_SYS_QE_FMAN_FW_IN_SPIFLASH
5033 Specifies that QE/FMAN firmware is located on the primary SPI
5034 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
5036 - CONFIG_SYS_QE_FMAN_FW_IN_REMOTE
5037 Specifies that QE/FMAN firmware is located in the remote (master)
5038 memory space. CONFIG_SYS_FMAN_FW_ADDR is a virtual address which
5039 can be mapped from slave TLB->slave LAW->slave SRIO or PCIE outbound
5040 window->master inbound window->master LAW->the ucode address in
5041 master's memory space.
5043 Freescale Layerscape Management Complex Firmware Support:
5044 ---------------------------------------------------------
5045 The Freescale Layerscape Management Complex (MC) supports the loading of
5047 This firmware often needs to be loaded during U-Boot booting, so macros
5048 are used to identify the storage device (NOR flash, SPI, etc) and the address
5051 - CONFIG_FSL_MC_ENET
5052 Enable the MC driver for Layerscape SoCs.
5054 - CONFIG_SYS_LS_MC_FW_ADDR
5055 The address in the storage device where the firmware is located. The
5056 meaning of this address depends on which CONFIG_SYS_LS_MC_FW_IN_xxx macro
5059 - CONFIG_SYS_LS_MC_FW_LENGTH
5060 The maximum possible size of the firmware. The firmware binary format
5061 has a field that specifies the actual size of the firmware, but it
5062 might not be possible to read any part of the firmware unless some
5063 local storage is allocated to hold the entire firmware first.
5065 - CONFIG_SYS_LS_MC_FW_IN_NOR
5066 Specifies that MC firmware is located in NOR flash, mapped as
5067 normal addressable memory via the LBC. CONFIG_SYS_LS_MC_FW_ADDR is the
5068 virtual address in NOR flash.
5070 Freescale Layerscape Debug Server Support:
5071 -------------------------------------------
5072 The Freescale Layerscape Debug Server Support supports the loading of
5073 "Debug Server firmware" and triggering SP boot-rom.
5074 This firmware often needs to be loaded during U-Boot booting.
5076 - CONFIG_FSL_DEBUG_SERVER
5077 Enable the Debug Server for Layerscape SoCs.
5079 - CONFIG_SYS_DEBUG_SERVER_DRAM_BLOCK_MIN_SIZE
5080 Define minimum DDR size required for debug server image
5082 - CONFIG_SYS_MEM_TOP_HIDE_MIN
5083 Define minimum DDR size to be hided from top of the DDR memory
5088 In order to achieve reproducible builds, timestamps used in the U-Boot build
5089 process have to be set to a fixed value.
5091 This is done using the SOURCE_DATE_EPOCH environment variable.
5092 SOURCE_DATE_EPOCH is to be set on the build host's shell, not as a configuration
5093 option for U-Boot or an environment variable in U-Boot.
5095 SOURCE_DATE_EPOCH should be set to a number of seconds since the epoch, in UTC.
5097 Building the Software:
5098 ======================
5100 Building U-Boot has been tested in several native build environments
5101 and in many different cross environments. Of course we cannot support
5102 all possibly existing versions of cross development tools in all
5103 (potentially obsolete) versions. In case of tool chain problems we
5104 recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK)
5105 which is extensively used to build and test U-Boot.
5107 If you are not using a native environment, it is assumed that you
5108 have GNU cross compiling tools available in your path. In this case,
5109 you must set the environment variable CROSS_COMPILE in your shell.
5110 Note that no changes to the Makefile or any other source files are
5111 necessary. For example using the ELDK on a 4xx CPU, please enter:
5113 $ CROSS_COMPILE=ppc_4xx-
5114 $ export CROSS_COMPILE
5116 Note: If you wish to generate Windows versions of the utilities in
5117 the tools directory you can use the MinGW toolchain
5118 (http://www.mingw.org). Set your HOST tools to the MinGW
5119 toolchain and execute 'make tools'. For example:
5121 $ make HOSTCC=i586-mingw32msvc-gcc HOSTSTRIP=i586-mingw32msvc-strip tools
5123 Binaries such as tools/mkimage.exe will be created which can
5124 be executed on computers running Windows.
5126 U-Boot is intended to be simple to build. After installing the
5127 sources you must configure U-Boot for one specific board type. This
5132 where "NAME_defconfig" is the name of one of the existing configu-
5133 rations; see boards.cfg for supported names.
5135 Note: for some board special configuration names may exist; check if
5136 additional information is available from the board vendor; for
5137 instance, the TQM823L systems are available without (standard)
5138 or with LCD support. You can select such additional "features"
5139 when choosing the configuration, i. e.
5141 make TQM823L_defconfig
5142 - will configure for a plain TQM823L, i. e. no LCD support
5144 make TQM823L_LCD_defconfig
5145 - will configure for a TQM823L with U-Boot console on LCD
5150 Finally, type "make all", and you should get some working U-Boot
5151 images ready for download to / installation on your system:
5153 - "u-boot.bin" is a raw binary image
5154 - "u-boot" is an image in ELF binary format
5155 - "u-boot.srec" is in Motorola S-Record format
5157 By default the build is performed locally and the objects are saved
5158 in the source directory. One of the two methods can be used to change
5159 this behavior and build U-Boot to some external directory:
5161 1. Add O= to the make command line invocations:
5163 make O=/tmp/build distclean
5164 make O=/tmp/build NAME_defconfig
5165 make O=/tmp/build all
5167 2. Set environment variable KBUILD_OUTPUT to point to the desired location:
5169 export KBUILD_OUTPUT=/tmp/build
5174 Note that the command line "O=" setting overrides the KBUILD_OUTPUT environment
5178 Please be aware that the Makefiles assume you are using GNU make, so
5179 for instance on NetBSD you might need to use "gmake" instead of
5183 If the system board that you have is not listed, then you will need
5184 to port U-Boot to your hardware platform. To do this, follow these
5187 1. Add a new configuration option for your board to the toplevel
5188 "boards.cfg" file, using the existing entries as examples.
5189 Follow the instructions there to keep the boards in order.
5190 2. Create a new directory to hold your board specific code. Add any
5191 files you need. In your board directory, you will need at least
5192 the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds".
5193 3. Create a new configuration file "include/configs/<board>.h" for
5195 3. If you're porting U-Boot to a new CPU, then also create a new
5196 directory to hold your CPU specific code. Add any files you need.
5197 4. Run "make <board>_defconfig" with your new name.
5198 5. Type "make", and you should get a working "u-boot.srec" file
5199 to be installed on your target system.
5200 6. Debug and solve any problems that might arise.
5201 [Of course, this last step is much harder than it sounds.]
5204 Testing of U-Boot Modifications, Ports to New Hardware, etc.:
5205 ==============================================================
5207 If you have modified U-Boot sources (for instance added a new board
5208 or support for new devices, a new CPU, etc.) you are expected to
5209 provide feedback to the other developers. The feedback normally takes
5210 the form of a "patch", i. e. a context diff against a certain (latest
5211 official or latest in the git repository) version of U-Boot sources.
5213 But before you submit such a patch, please verify that your modifi-
5214 cation did not break existing code. At least make sure that *ALL* of
5215 the supported boards compile WITHOUT ANY compiler warnings. To do so,
5216 just run the "MAKEALL" script, which will configure and build U-Boot
5217 for ALL supported system. Be warned, this will take a while. You can
5218 select which (cross) compiler to use by passing a `CROSS_COMPILE'
5219 environment variable to the script, i. e. to use the ELDK cross tools
5222 CROSS_COMPILE=ppc_8xx- MAKEALL
5224 or to build on a native PowerPC system you can type
5226 CROSS_COMPILE=' ' MAKEALL
5228 When using the MAKEALL script, the default behaviour is to build
5229 U-Boot in the source directory. This location can be changed by
5230 setting the BUILD_DIR environment variable. Also, for each target
5231 built, the MAKEALL script saves two log files (<target>.ERR and
5232 <target>.MAKEALL) in the <source dir>/LOG directory. This default
5233 location can be changed by setting the MAKEALL_LOGDIR environment
5234 variable. For example:
5236 export BUILD_DIR=/tmp/build
5237 export MAKEALL_LOGDIR=/tmp/log
5238 CROSS_COMPILE=ppc_8xx- MAKEALL
5240 With the above settings build objects are saved in the /tmp/build,
5241 log files are saved in the /tmp/log and the source tree remains clean
5242 during the whole build process.
5245 See also "U-Boot Porting Guide" below.
5248 Monitor Commands - Overview:
5249 ============================
5251 go - start application at address 'addr'
5252 run - run commands in an environment variable
5253 bootm - boot application image from memory
5254 bootp - boot image via network using BootP/TFTP protocol
5255 bootz - boot zImage from memory
5256 tftpboot- boot image via network using TFTP protocol
5257 and env variables "ipaddr" and "serverip"
5258 (and eventually "gatewayip")
5259 tftpput - upload a file via network using TFTP protocol
5260 rarpboot- boot image via network using RARP/TFTP protocol
5261 diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
5262 loads - load S-Record file over serial line
5263 loadb - load binary file over serial line (kermit mode)
5265 mm - memory modify (auto-incrementing)
5266 nm - memory modify (constant address)
5267 mw - memory write (fill)
5269 cmp - memory compare
5270 crc32 - checksum calculation
5271 i2c - I2C sub-system
5272 sspi - SPI utility commands
5273 base - print or set address offset
5274 printenv- print environment variables
5275 setenv - set environment variables
5276 saveenv - save environment variables to persistent storage
5277 protect - enable or disable FLASH write protection
5278 erase - erase FLASH memory
5279 flinfo - print FLASH memory information
5280 nand - NAND memory operations (see doc/README.nand)
5281 bdinfo - print Board Info structure
5282 iminfo - print header information for application image
5283 coninfo - print console devices and informations
5284 ide - IDE sub-system
5285 loop - infinite loop on address range
5286 loopw - infinite write loop on address range
5287 mtest - simple RAM test
5288 icache - enable or disable instruction cache
5289 dcache - enable or disable data cache
5290 reset - Perform RESET of the CPU
5291 echo - echo args to console
5292 version - print monitor version
5293 help - print online help
5294 ? - alias for 'help'
5297 Monitor Commands - Detailed Description:
5298 ========================================
5302 For now: just type "help <command>".
5305 Environment Variables:
5306 ======================
5308 U-Boot supports user configuration using Environment Variables which
5309 can be made persistent by saving to Flash memory.
5311 Environment Variables are set using "setenv", printed using
5312 "printenv", and saved to Flash using "saveenv". Using "setenv"
5313 without a value can be used to delete a variable from the
5314 environment. As long as you don't save the environment you are
5315 working with an in-memory copy. In case the Flash area containing the
5316 environment is erased by accident, a default environment is provided.
5318 Some configuration options can be set using Environment Variables.
5320 List of environment variables (most likely not complete):
5322 baudrate - see CONFIG_BAUDRATE
5324 bootdelay - see CONFIG_BOOTDELAY
5326 bootcmd - see CONFIG_BOOTCOMMAND
5328 bootargs - Boot arguments when booting an RTOS image
5330 bootfile - Name of the image to load with TFTP
5332 bootm_low - Memory range available for image processing in the bootm
5333 command can be restricted. This variable is given as
5334 a hexadecimal number and defines lowest address allowed
5335 for use by the bootm command. See also "bootm_size"
5336 environment variable. Address defined by "bootm_low" is
5337 also the base of the initial memory mapping for the Linux
5338 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ and
5341 bootm_mapsize - Size of the initial memory mapping for the Linux kernel.
5342 This variable is given as a hexadecimal number and it
5343 defines the size of the memory region starting at base
5344 address bootm_low that is accessible by the Linux kernel
5345 during early boot. If unset, CONFIG_SYS_BOOTMAPSZ is used
5346 as the default value if it is defined, and bootm_size is
5349 bootm_size - Memory range available for image processing in the bootm
5350 command can be restricted. This variable is given as
5351 a hexadecimal number and defines the size of the region
5352 allowed for use by the bootm command. See also "bootm_low"
5353 environment variable.
5355 updatefile - Location of the software update file on a TFTP server, used
5356 by the automatic software update feature. Please refer to
5357 documentation in doc/README.update for more details.
5359 autoload - if set to "no" (any string beginning with 'n'),
5360 "bootp" will just load perform a lookup of the
5361 configuration from the BOOTP server, but not try to
5362 load any image using TFTP
5364 autostart - if set to "yes", an image loaded using the "bootp",
5365 "rarpboot", "tftpboot" or "diskboot" commands will
5366 be automatically started (by internally calling
5369 If set to "no", a standalone image passed to the
5370 "bootm" command will be copied to the load address
5371 (and eventually uncompressed), but NOT be started.
5372 This can be used to load and uncompress arbitrary
5375 fdt_high - if set this restricts the maximum address that the
5376 flattened device tree will be copied into upon boot.
5377 For example, if you have a system with 1 GB memory
5378 at physical address 0x10000000, while Linux kernel
5379 only recognizes the first 704 MB as low memory, you
5380 may need to set fdt_high as 0x3C000000 to have the
5381 device tree blob be copied to the maximum address
5382 of the 704 MB low memory, so that Linux kernel can
5383 access it during the boot procedure.
5385 If this is set to the special value 0xFFFFFFFF then
5386 the fdt will not be copied at all on boot. For this
5387 to work it must reside in writable memory, have
5388 sufficient padding on the end of it for u-boot to
5389 add the information it needs into it, and the memory
5390 must be accessible by the kernel.
5392 fdtcontroladdr- if set this is the address of the control flattened
5393 device tree used by U-Boot when CONFIG_OF_CONTROL is
5396 i2cfast - (PPC405GP|PPC405EP only)
5397 if set to 'y' configures Linux I2C driver for fast
5398 mode (400kHZ). This environment variable is used in
5399 initialization code. So, for changes to be effective
5400 it must be saved and board must be reset.
5402 initrd_high - restrict positioning of initrd images:
5403 If this variable is not set, initrd images will be
5404 copied to the highest possible address in RAM; this
5405 is usually what you want since it allows for
5406 maximum initrd size. If for some reason you want to
5407 make sure that the initrd image is loaded below the
5408 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment
5409 variable to a value of "no" or "off" or "0".
5410 Alternatively, you can set it to a maximum upper
5411 address to use (U-Boot will still check that it
5412 does not overwrite the U-Boot stack and data).
5414 For instance, when you have a system with 16 MB
5415 RAM, and want to reserve 4 MB from use by Linux,
5416 you can do this by adding "mem=12M" to the value of
5417 the "bootargs" variable. However, now you must make
5418 sure that the initrd image is placed in the first
5419 12 MB as well - this can be done with
5421 setenv initrd_high 00c00000
5423 If you set initrd_high to 0xFFFFFFFF, this is an
5424 indication to U-Boot that all addresses are legal
5425 for the Linux kernel, including addresses in flash
5426 memory. In this case U-Boot will NOT COPY the
5427 ramdisk at all. This may be useful to reduce the
5428 boot time on your system, but requires that this
5429 feature is supported by your Linux kernel.
5431 ipaddr - IP address; needed for tftpboot command
5433 loadaddr - Default load address for commands like "bootp",
5434 "rarpboot", "tftpboot", "loadb" or "diskboot"
5436 loads_echo - see CONFIG_LOADS_ECHO
5438 serverip - TFTP server IP address; needed for tftpboot command
5440 bootretry - see CONFIG_BOOT_RETRY_TIME
5442 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
5444 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
5446 ethprime - controls which interface is used first.
5448 ethact - controls which interface is currently active.
5449 For example you can do the following
5451 => setenv ethact FEC
5452 => ping 192.168.0.1 # traffic sent on FEC
5453 => setenv ethact SCC
5454 => ping 10.0.0.1 # traffic sent on SCC
5456 ethrotate - When set to "no" U-Boot does not go through all
5457 available network interfaces.
5458 It just stays at the currently selected interface.
5460 netretry - When set to "no" each network operation will
5461 either succeed or fail without retrying.
5462 When set to "once" the network operation will
5463 fail when all the available network interfaces
5464 are tried once without success.
5465 Useful on scripts which control the retry operation
5468 npe_ucode - set load address for the NPE microcode
5470 silent_linux - If set then Linux will be told to boot silently, by
5471 changing the console to be empty. If "yes" it will be
5472 made silent. If "no" it will not be made silent. If
5473 unset, then it will be made silent if the U-Boot console
5476 tftpsrcport - If this is set, the value is used for TFTP's
5479 tftpdstport - If this is set, the value is used for TFTP's UDP
5480 destination port instead of the Well Know Port 69.
5482 tftpblocksize - Block size to use for TFTP transfers; if not set,
5483 we use the TFTP server's default block size
5485 tftptimeout - Retransmission timeout for TFTP packets (in milli-
5486 seconds, minimum value is 1000 = 1 second). Defines
5487 when a packet is considered to be lost so it has to
5488 be retransmitted. The default is 5000 = 5 seconds.
5489 Lowering this value may make downloads succeed
5490 faster in networks with high packet loss rates or
5491 with unreliable TFTP servers.
5493 vlan - When set to a value < 4095 the traffic over
5494 Ethernet is encapsulated/received over 802.1q
5497 The following image location variables contain the location of images
5498 used in booting. The "Image" column gives the role of the image and is
5499 not an environment variable name. The other columns are environment
5500 variable names. "File Name" gives the name of the file on a TFTP
5501 server, "RAM Address" gives the location in RAM the image will be
5502 loaded to, and "Flash Location" gives the image's address in NOR
5503 flash or offset in NAND flash.
5505 *Note* - these variables don't have to be defined for all boards, some
5506 boards currently use other variables for these purposes, and some
5507 boards use these variables for other purposes.
5509 Image File Name RAM Address Flash Location
5510 ----- --------- ----------- --------------
5511 u-boot u-boot u-boot_addr_r u-boot_addr
5512 Linux kernel bootfile kernel_addr_r kernel_addr
5513 device tree blob fdtfile fdt_addr_r fdt_addr
5514 ramdisk ramdiskfile ramdisk_addr_r ramdisk_addr
5516 The following environment variables may be used and automatically
5517 updated by the network boot commands ("bootp" and "rarpboot"),
5518 depending the information provided by your boot server:
5520 bootfile - see above
5521 dnsip - IP address of your Domain Name Server
5522 dnsip2 - IP address of your secondary Domain Name Server
5523 gatewayip - IP address of the Gateway (Router) to use
5524 hostname - Target hostname
5526 netmask - Subnet Mask
5527 rootpath - Pathname of the root filesystem on the NFS server
5528 serverip - see above
5531 There are two special Environment Variables:
5533 serial# - contains hardware identification information such
5534 as type string and/or serial number
5535 ethaddr - Ethernet address
5537 These variables can be set only once (usually during manufacturing of
5538 the board). U-Boot refuses to delete or overwrite these variables
5539 once they have been set once.
5542 Further special Environment Variables:
5544 ver - Contains the U-Boot version string as printed
5545 with the "version" command. This variable is
5546 readonly (see CONFIG_VERSION_VARIABLE).
5549 Please note that changes to some configuration parameters may take
5550 only effect after the next boot (yes, that's just like Windoze :-).
5553 Callback functions for environment variables:
5554 ---------------------------------------------
5556 For some environment variables, the behavior of u-boot needs to change
5557 when their values are changed. This functionality allows functions to
5558 be associated with arbitrary variables. On creation, overwrite, or
5559 deletion, the callback will provide the opportunity for some side
5560 effect to happen or for the change to be rejected.
5562 The callbacks are named and associated with a function using the
5563 U_BOOT_ENV_CALLBACK macro in your board or driver code.
5565 These callbacks are associated with variables in one of two ways. The
5566 static list can be added to by defining CONFIG_ENV_CALLBACK_LIST_STATIC
5567 in the board configuration to a string that defines a list of
5568 associations. The list must be in the following format:
5570 entry = variable_name[:callback_name]
5573 If the callback name is not specified, then the callback is deleted.
5574 Spaces are also allowed anywhere in the list.
5576 Callbacks can also be associated by defining the ".callbacks" variable
5577 with the same list format above. Any association in ".callbacks" will
5578 override any association in the static list. You can define
5579 CONFIG_ENV_CALLBACK_LIST_DEFAULT to a list (string) to define the
5580 ".callbacks" environment variable in the default or embedded environment.
5582 If CONFIG_REGEX is defined, the variable_name above is evaluated as a
5583 regular expression. This allows multiple variables to be connected to
5584 the same callback without explicitly listing them all out.
5587 Command Line Parsing:
5588 =====================
5590 There are two different command line parsers available with U-Boot:
5591 the old "simple" one, and the much more powerful "hush" shell:
5593 Old, simple command line parser:
5594 --------------------------------
5596 - supports environment variables (through setenv / saveenv commands)
5597 - several commands on one line, separated by ';'
5598 - variable substitution using "... ${name} ..." syntax
5599 - special characters ('$', ';') can be escaped by prefixing with '\',
5601 setenv bootcmd bootm \${address}
5602 - You can also escape text by enclosing in single apostrophes, for example:
5603 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
5608 - similar to Bourne shell, with control structures like
5609 if...then...else...fi, for...do...done; while...do...done,
5610 until...do...done, ...
5611 - supports environment ("global") variables (through setenv / saveenv
5612 commands) and local shell variables (through standard shell syntax
5613 "name=value"); only environment variables can be used with "run"
5619 (1) If a command line (or an environment variable executed by a "run"
5620 command) contains several commands separated by semicolon, and
5621 one of these commands fails, then the remaining commands will be
5624 (2) If you execute several variables with one call to run (i. e.
5625 calling run with a list of variables as arguments), any failing
5626 command will cause "run" to terminate, i. e. the remaining
5627 variables are not executed.
5629 Note for Redundant Ethernet Interfaces:
5630 =======================================
5632 Some boards come with redundant Ethernet interfaces; U-Boot supports
5633 such configurations and is capable of automatic selection of a
5634 "working" interface when needed. MAC assignment works as follows:
5636 Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
5637 MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
5638 "eth1addr" (=>eth1), "eth2addr", ...
5640 If the network interface stores some valid MAC address (for instance
5641 in SROM), this is used as default address if there is NO correspon-
5642 ding setting in the environment; if the corresponding environment
5643 variable is set, this overrides the settings in the card; that means:
5645 o If the SROM has a valid MAC address, and there is no address in the
5646 environment, the SROM's address is used.
5648 o If there is no valid address in the SROM, and a definition in the
5649 environment exists, then the value from the environment variable is
5652 o If both the SROM and the environment contain a MAC address, and
5653 both addresses are the same, this MAC address is used.
5655 o If both the SROM and the environment contain a MAC address, and the
5656 addresses differ, the value from the environment is used and a
5659 o If neither SROM nor the environment contain a MAC address, an error
5660 is raised. If CONFIG_NET_RANDOM_ETHADDR is defined, then in this case
5661 a random, locally-assigned MAC is used.
5663 If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses
5664 will be programmed into hardware as part of the initialization process. This
5665 may be skipped by setting the appropriate 'ethmacskip' environment variable.
5666 The naming convention is as follows:
5667 "ethmacskip" (=>eth0), "eth1macskip" (=>eth1) etc.
5672 U-Boot is capable of booting (and performing other auxiliary operations on)
5673 images in two formats:
5675 New uImage format (FIT)
5676 -----------------------
5678 Flexible and powerful format based on Flattened Image Tree -- FIT (similar
5679 to Flattened Device Tree). It allows the use of images with multiple
5680 components (several kernels, ramdisks, etc.), with contents protected by
5681 SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory.
5687 Old image format is based on binary files which can be basically anything,
5688 preceded by a special header; see the definitions in include/image.h for
5689 details; basically, the header defines the following image properties:
5691 * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
5692 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
5693 LynxOS, pSOS, QNX, RTEMS, INTEGRITY;
5694 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS,
5696 * Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86,
5697 IA64, MIPS, NDS32, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
5698 Currently supported: ARM, AVR32, Intel x86, MIPS, NDS32, Nios II, PowerPC).
5699 * Compression Type (uncompressed, gzip, bzip2)
5705 The header is marked by a special Magic Number, and both the header
5706 and the data portions of the image are secured against corruption by
5713 Although U-Boot should support any OS or standalone application
5714 easily, the main focus has always been on Linux during the design of
5717 U-Boot includes many features that so far have been part of some
5718 special "boot loader" code within the Linux kernel. Also, any
5719 "initrd" images to be used are no longer part of one big Linux image;
5720 instead, kernel and "initrd" are separate images. This implementation
5721 serves several purposes:
5723 - the same features can be used for other OS or standalone
5724 applications (for instance: using compressed images to reduce the
5725 Flash memory footprint)
5727 - it becomes much easier to port new Linux kernel versions because
5728 lots of low-level, hardware dependent stuff are done by U-Boot
5730 - the same Linux kernel image can now be used with different "initrd"
5731 images; of course this also means that different kernel images can
5732 be run with the same "initrd". This makes testing easier (you don't
5733 have to build a new "zImage.initrd" Linux image when you just
5734 change a file in your "initrd"). Also, a field-upgrade of the
5735 software is easier now.
5741 Porting Linux to U-Boot based systems:
5742 ---------------------------------------
5744 U-Boot cannot save you from doing all the necessary modifications to
5745 configure the Linux device drivers for use with your target hardware
5746 (no, we don't intend to provide a full virtual machine interface to
5749 But now you can ignore ALL boot loader code (in arch/powerpc/mbxboot).
5751 Just make sure your machine specific header file (for instance
5752 include/asm-ppc/tqm8xx.h) includes the same definition of the Board
5753 Information structure as we define in include/asm-<arch>/u-boot.h,
5754 and make sure that your definition of IMAP_ADDR uses the same value
5755 as your U-Boot configuration in CONFIG_SYS_IMMR.
5757 Note that U-Boot now has a driver model, a unified model for drivers.
5758 If you are adding a new driver, plumb it into driver model. If there
5759 is no uclass available, you are encouraged to create one. See
5763 Configuring the Linux kernel:
5764 -----------------------------
5766 No specific requirements for U-Boot. Make sure you have some root
5767 device (initial ramdisk, NFS) for your target system.
5770 Building a Linux Image:
5771 -----------------------
5773 With U-Boot, "normal" build targets like "zImage" or "bzImage" are
5774 not used. If you use recent kernel source, a new build target
5775 "uImage" will exist which automatically builds an image usable by
5776 U-Boot. Most older kernels also have support for a "pImage" target,
5777 which was introduced for our predecessor project PPCBoot and uses a
5778 100% compatible format.
5782 make TQM850L_defconfig
5787 The "uImage" build target uses a special tool (in 'tools/mkimage') to
5788 encapsulate a compressed Linux kernel image with header information,
5789 CRC32 checksum etc. for use with U-Boot. This is what we are doing:
5791 * build a standard "vmlinux" kernel image (in ELF binary format):
5793 * convert the kernel into a raw binary image:
5795 ${CROSS_COMPILE}-objcopy -O binary \
5796 -R .note -R .comment \
5797 -S vmlinux linux.bin
5799 * compress the binary image:
5803 * package compressed binary image for U-Boot:
5805 mkimage -A ppc -O linux -T kernel -C gzip \
5806 -a 0 -e 0 -n "Linux Kernel Image" \
5807 -d linux.bin.gz uImage
5810 The "mkimage" tool can also be used to create ramdisk images for use
5811 with U-Boot, either separated from the Linux kernel image, or
5812 combined into one file. "mkimage" encapsulates the images with a 64
5813 byte header containing information about target architecture,
5814 operating system, image type, compression method, entry points, time
5815 stamp, CRC32 checksums, etc.
5817 "mkimage" can be called in two ways: to verify existing images and
5818 print the header information, or to build new images.
5820 In the first form (with "-l" option) mkimage lists the information
5821 contained in the header of an existing U-Boot image; this includes
5822 checksum verification:
5824 tools/mkimage -l image
5825 -l ==> list image header information
5827 The second form (with "-d" option) is used to build a U-Boot image
5828 from a "data file" which is used as image payload:
5830 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
5831 -n name -d data_file image
5832 -A ==> set architecture to 'arch'
5833 -O ==> set operating system to 'os'
5834 -T ==> set image type to 'type'
5835 -C ==> set compression type 'comp'
5836 -a ==> set load address to 'addr' (hex)
5837 -e ==> set entry point to 'ep' (hex)
5838 -n ==> set image name to 'name'
5839 -d ==> use image data from 'datafile'
5841 Right now, all Linux kernels for PowerPC systems use the same load
5842 address (0x00000000), but the entry point address depends on the
5845 - 2.2.x kernels have the entry point at 0x0000000C,
5846 - 2.3.x and later kernels have the entry point at 0x00000000.
5848 So a typical call to build a U-Boot image would read:
5850 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
5851 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
5852 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz \
5853 > examples/uImage.TQM850L
5854 Image Name: 2.4.4 kernel for TQM850L
5855 Created: Wed Jul 19 02:34:59 2000
5856 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5857 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
5858 Load Address: 0x00000000
5859 Entry Point: 0x00000000
5861 To verify the contents of the image (or check for corruption):
5863 -> tools/mkimage -l examples/uImage.TQM850L
5864 Image Name: 2.4.4 kernel for TQM850L
5865 Created: Wed Jul 19 02:34:59 2000
5866 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5867 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
5868 Load Address: 0x00000000
5869 Entry Point: 0x00000000
5871 NOTE: for embedded systems where boot time is critical you can trade
5872 speed for memory and install an UNCOMPRESSED image instead: this
5873 needs more space in Flash, but boots much faster since it does not
5874 need to be uncompressed:
5876 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz
5877 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
5878 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
5879 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux \
5880 > examples/uImage.TQM850L-uncompressed
5881 Image Name: 2.4.4 kernel for TQM850L
5882 Created: Wed Jul 19 02:34:59 2000
5883 Image Type: PowerPC Linux Kernel Image (uncompressed)
5884 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
5885 Load Address: 0x00000000
5886 Entry Point: 0x00000000
5889 Similar you can build U-Boot images from a 'ramdisk.image.gz' file
5890 when your kernel is intended to use an initial ramdisk:
5892 -> tools/mkimage -n 'Simple Ramdisk Image' \
5893 > -A ppc -O linux -T ramdisk -C gzip \
5894 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
5895 Image Name: Simple Ramdisk Image
5896 Created: Wed Jan 12 14:01:50 2000
5897 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5898 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
5899 Load Address: 0x00000000
5900 Entry Point: 0x00000000
5902 The "dumpimage" is a tool to disassemble images built by mkimage. Its "-i"
5903 option performs the converse operation of the mkimage's second form (the "-d"
5904 option). Given an image built by mkimage, the dumpimage extracts a "data file"
5907 tools/dumpimage -i image -T type -p position data_file
5908 -i ==> extract from the 'image' a specific 'data_file'
5909 -T ==> set image type to 'type'
5910 -p ==> 'position' (starting at 0) of the 'data_file' inside the 'image'
5913 Installing a Linux Image:
5914 -------------------------
5916 To downloading a U-Boot image over the serial (console) interface,
5917 you must convert the image to S-Record format:
5919 objcopy -I binary -O srec examples/image examples/image.srec
5921 The 'objcopy' does not understand the information in the U-Boot
5922 image header, so the resulting S-Record file will be relative to
5923 address 0x00000000. To load it to a given address, you need to
5924 specify the target address as 'offset' parameter with the 'loads'
5927 Example: install the image to address 0x40100000 (which on the
5928 TQM8xxL is in the first Flash bank):
5930 => erase 40100000 401FFFFF
5936 ## Ready for S-Record download ...
5937 ~>examples/image.srec
5938 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
5940 15989 15990 15991 15992
5941 [file transfer complete]
5943 ## Start Addr = 0x00000000
5946 You can check the success of the download using the 'iminfo' command;
5947 this includes a checksum verification so you can be sure no data
5948 corruption happened:
5952 ## Checking Image at 40100000 ...
5953 Image Name: 2.2.13 for initrd on TQM850L
5954 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5955 Data Size: 335725 Bytes = 327 kB = 0 MB
5956 Load Address: 00000000
5957 Entry Point: 0000000c
5958 Verifying Checksum ... OK
5964 The "bootm" command is used to boot an application that is stored in
5965 memory (RAM or Flash). In case of a Linux kernel image, the contents
5966 of the "bootargs" environment variable is passed to the kernel as
5967 parameters. You can check and modify this variable using the
5968 "printenv" and "setenv" commands:
5971 => printenv bootargs
5972 bootargs=root=/dev/ram
5974 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5976 => printenv bootargs
5977 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5980 ## Booting Linux kernel at 40020000 ...
5981 Image Name: 2.2.13 for NFS on TQM850L
5982 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5983 Data Size: 381681 Bytes = 372 kB = 0 MB
5984 Load Address: 00000000
5985 Entry Point: 0000000c
5986 Verifying Checksum ... OK
5987 Uncompressing Kernel Image ... OK
5988 Linux version 2.2.13 (
[email protected]) (gcc version 2.95.2 19991024 (release)) #1 Wed Jul 19 02:35:17 MEST 2000
5989 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5990 time_init: decrementer frequency = 187500000/60
5991 Calibrating delay loop... 49.77 BogoMIPS
5992 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
5995 If you want to boot a Linux kernel with initial RAM disk, you pass
5996 the memory addresses of both the kernel and the initrd image (PPBCOOT
5997 format!) to the "bootm" command:
5999 => imi 40100000 40200000
6001 ## Checking Image at 40100000 ...
6002 Image Name: 2.2.13 for initrd on TQM850L
6003 Image Type: PowerPC Linux Kernel Image (gzip compressed)
6004 Data Size: 335725 Bytes = 327 kB = 0 MB
6005 Load Address: 00000000
6006 Entry Point: 0000000c
6007 Verifying Checksum ... OK
6009 ## Checking Image at 40200000 ...
6010 Image Name: Simple Ramdisk Image
6011 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
6012 Data Size: 566530 Bytes = 553 kB = 0 MB
6013 Load Address: 00000000
6014 Entry Point: 00000000
6015 Verifying Checksum ... OK
6017 => bootm 40100000 40200000
6018 ## Booting Linux kernel at 40100000 ...
6019 Image Name: 2.2.13 for initrd on TQM850L
6020 Image Type: PowerPC Linux Kernel Image (gzip compressed)
6021 Data Size: 335725 Bytes = 327 kB = 0 MB
6022 Load Address: 00000000
6023 Entry Point: 0000000c
6024 Verifying Checksum ... OK
6025 Uncompressing Kernel Image ... OK
6026 ## Loading RAMDisk Image at 40200000 ...
6027 Image Name: Simple Ramdisk Image
6028 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
6029 Data Size: 566530 Bytes = 553 kB = 0 MB
6030 Load Address: 00000000
6031 Entry Point: 00000000
6032 Verifying Checksum ... OK
6033 Loading Ramdisk ... OK
6034 Linux version 2.2.13 (
[email protected]) (gcc version 2.95.2 19991024 (release)) #1 Wed Jul 19 02:32:08 MEST 2000
6035 Boot arguments: root=/dev/ram
6036 time_init: decrementer frequency = 187500000/60
6037 Calibrating delay loop... 49.77 BogoMIPS
6039 RAMDISK: Compressed image found at block 0
6040 VFS: Mounted root (ext2 filesystem).
6044 Boot Linux and pass a flat device tree:
6047 First, U-Boot must be compiled with the appropriate defines. See the section
6048 titled "Linux Kernel Interface" above for a more in depth explanation. The
6049 following is an example of how to start a kernel and pass an updated
6055 oft=oftrees/mpc8540ads.dtb
6056 => tftp $oftaddr $oft
6057 Speed: 1000, full duplex
6059 TFTP from server 192.168.1.1; our IP address is 192.168.1.101
6060 Filename 'oftrees/mpc8540ads.dtb'.
6061 Load address: 0x300000
6064 Bytes transferred = 4106 (100a hex)
6065 => tftp $loadaddr $bootfile
6066 Speed: 1000, full duplex
6068 TFTP from server 192.168.1.1; our IP address is 192.168.1.2
6070 Load address: 0x200000
6071 Loading:############
6073 Bytes transferred = 1029407 (fb51f hex)
6078 => bootm $loadaddr - $oftaddr
6079 ## Booting image at 00200000 ...
6080 Image Name: Linux-2.6.17-dirty
6081 Image Type: PowerPC Linux Kernel Image (gzip compressed)
6082 Data Size: 1029343 Bytes = 1005.2 kB
6083 Load Address: 00000000
6084 Entry Point: 00000000
6085 Verifying Checksum ... OK
6086 Uncompressing Kernel Image ... OK
6087 Booting using flat device tree at 0x300000
6088 Using MPC85xx ADS machine description
6089 Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb
6093 More About U-Boot Image Types:
6094 ------------------------------
6096 U-Boot supports the following image types:
6098 "Standalone Programs" are directly runnable in the environment
6099 provided by U-Boot; it is expected that (if they behave
6100 well) you can continue to work in U-Boot after return from
6101 the Standalone Program.
6102 "OS Kernel Images" are usually images of some Embedded OS which
6103 will take over control completely. Usually these programs
6104 will install their own set of exception handlers, device
6105 drivers, set up the MMU, etc. - this means, that you cannot
6106 expect to re-enter U-Boot except by resetting the CPU.
6107 "RAMDisk Images" are more or less just data blocks, and their
6108 parameters (address, size) are passed to an OS kernel that is
6110 "Multi-File Images" contain several images, typically an OS
6111 (Linux) kernel image and one or more data images like
6112 RAMDisks. This construct is useful for instance when you want
6113 to boot over the network using BOOTP etc., where the boot
6114 server provides just a single image file, but you want to get
6115 for instance an OS kernel and a RAMDisk image.
6117 "Multi-File Images" start with a list of image sizes, each
6118 image size (in bytes) specified by an "uint32_t" in network
6119 byte order. This list is terminated by an "(uint32_t)0".
6120 Immediately after the terminating 0 follow the images, one by
6121 one, all aligned on "uint32_t" boundaries (size rounded up to
6122 a multiple of 4 bytes).
6124 "Firmware Images" are binary images containing firmware (like
6125 U-Boot or FPGA images) which usually will be programmed to
6128 "Script files" are command sequences that will be executed by
6129 U-Boot's command interpreter; this feature is especially
6130 useful when you configure U-Boot to use a real shell (hush)
6131 as command interpreter.
6133 Booting the Linux zImage:
6134 -------------------------
6136 On some platforms, it's possible to boot Linux zImage. This is done
6137 using the "bootz" command. The syntax of "bootz" command is the same
6138 as the syntax of "bootm" command.
6140 Note, defining the CONFIG_SUPPORT_RAW_INITRD allows user to supply
6141 kernel with raw initrd images. The syntax is slightly different, the
6142 address of the initrd must be augmented by it's size, in the following
6143 format: "<initrd addres>:<initrd size>".
6149 One of the features of U-Boot is that you can dynamically load and
6150 run "standalone" applications, which can use some resources of
6151 U-Boot like console I/O functions or interrupt services.
6153 Two simple examples are included with the sources:
6158 'examples/hello_world.c' contains a small "Hello World" Demo
6159 application; it is automatically compiled when you build U-Boot.
6160 It's configured to run at address 0x00040004, so you can play with it
6164 ## Ready for S-Record download ...
6165 ~>examples/hello_world.srec
6166 1 2 3 4 5 6 7 8 9 10 11 ...
6167 [file transfer complete]
6169 ## Start Addr = 0x00040004
6171 => go 40004 Hello World! This is a test.
6172 ## Starting application at 0x00040004 ...
6183 Hit any key to exit ...
6185 ## Application terminated, rc = 0x0
6187 Another example, which demonstrates how to register a CPM interrupt
6188 handler with the U-Boot code, can be found in 'examples/timer.c'.
6189 Here, a CPM timer is set up to generate an interrupt every second.
6190 The interrupt service routine is trivial, just printing a '.'
6191 character, but this is just a demo program. The application can be
6192 controlled by the following keys:
6194 ? - print current values og the CPM Timer registers
6195 b - enable interrupts and start timer
6196 e - stop timer and disable interrupts
6197 q - quit application
6200 ## Ready for S-Record download ...
6201 ~>examples/timer.srec
6202 1 2 3 4 5 6 7 8 9 10 11 ...
6203 [file transfer complete]
6205 ## Start Addr = 0x00040004
6208 ## Starting application at 0x00040004 ...
6211 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
6214 [q, b, e, ?] Set interval 1000000 us
6217 [q, b, e, ?] ........
6218 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
6221 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
6224 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
6227 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
6229 [q, b, e, ?] ...Stopping timer
6231 [q, b, e, ?] ## Application terminated, rc = 0x0
6237 Over time, many people have reported problems when trying to use the
6238 "minicom" terminal emulation program for serial download. I (wd)
6239 consider minicom to be broken, and recommend not to use it. Under
6240 Unix, I recommend to use C-Kermit for general purpose use (and
6241 especially for kermit binary protocol download ("loadb" command), and
6242 use "cu" for S-Record download ("loads" command). See
6243 http://www.denx.de/wiki/view/DULG/SystemSetup#Section_4.3.
6244 for help with kermit.
6247 Nevertheless, if you absolutely want to use it try adding this
6248 configuration to your "File transfer protocols" section:
6250 Name Program Name U/D FullScr IO-Red. Multi
6251 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
6252 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
6258 Starting at version 0.9.2, U-Boot supports NetBSD both as host
6259 (build U-Boot) and target system (boots NetBSD/mpc8xx).
6261 Building requires a cross environment; it is known to work on
6262 NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
6263 need gmake since the Makefiles are not compatible with BSD make).
6264 Note that the cross-powerpc package does not install include files;
6265 attempting to build U-Boot will fail because <machine/ansi.h> is
6266 missing. This file has to be installed and patched manually:
6268 # cd /usr/pkg/cross/powerpc-netbsd/include
6270 # ln -s powerpc machine
6271 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
6272 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
6274 Native builds *don't* work due to incompatibilities between native
6275 and U-Boot include files.
6277 Booting assumes that (the first part of) the image booted is a
6278 stage-2 loader which in turn loads and then invokes the kernel
6279 proper. Loader sources will eventually appear in the NetBSD source
6280 tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
6281 meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz
6284 Implementation Internals:
6285 =========================
6287 The following is not intended to be a complete description of every
6288 implementation detail. However, it should help to understand the
6289 inner workings of U-Boot and make it easier to port it to custom
6293 Initial Stack, Global Data:
6294 ---------------------------
6296 The implementation of U-Boot is complicated by the fact that U-Boot
6297 starts running out of ROM (flash memory), usually without access to
6298 system RAM (because the memory controller is not initialized yet).
6299 This means that we don't have writable Data or BSS segments, and BSS
6300 is not initialized as zero. To be able to get a C environment working
6301 at all, we have to allocate at least a minimal stack. Implementation
6302 options for this are defined and restricted by the CPU used: Some CPU
6303 models provide on-chip memory (like the IMMR area on MPC8xx and
6304 MPC826x processors), on others (parts of) the data cache can be
6305 locked as (mis-) used as memory, etc.
6307 Chris Hallinan posted a good summary of these issues to the
6308 U-Boot mailing list:
6310 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
6312 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
6315 Correct me if I'm wrong, folks, but the way I understand it
6316 is this: Using DCACHE as initial RAM for Stack, etc, does not
6317 require any physical RAM backing up the cache. The cleverness
6318 is that the cache is being used as a temporary supply of
6319 necessary storage before the SDRAM controller is setup. It's
6320 beyond the scope of this list to explain the details, but you
6321 can see how this works by studying the cache architecture and
6322 operation in the architecture and processor-specific manuals.
6324 OCM is On Chip Memory, which I believe the 405GP has 4K. It
6325 is another option for the system designer to use as an
6326 initial stack/RAM area prior to SDRAM being available. Either
6327 option should work for you. Using CS 4 should be fine if your
6328 board designers haven't used it for something that would
6329 cause you grief during the initial boot! It is frequently not
6332 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere
6333 with your processor/board/system design. The default value
6334 you will find in any recent u-boot distribution in
6335 walnut.h should work for you. I'd set it to a value larger
6336 than your SDRAM module. If you have a 64MB SDRAM module, set
6337 it above 400_0000. Just make sure your board has no resources
6338 that are supposed to respond to that address! That code in
6339 start.S has been around a while and should work as is when
6340 you get the config right.
6345 It is essential to remember this, since it has some impact on the C
6346 code for the initialization procedures:
6348 * Initialized global data (data segment) is read-only. Do not attempt
6351 * Do not use any uninitialized global data (or implicitly initialized
6352 as zero data - BSS segment) at all - this is undefined, initiali-
6353 zation is performed later (when relocating to RAM).
6355 * Stack space is very limited. Avoid big data buffers or things like
6358 Having only the stack as writable memory limits means we cannot use
6359 normal global data to share information between the code. But it
6360 turned out that the implementation of U-Boot can be greatly
6361 simplified by making a global data structure (gd_t) available to all
6362 functions. We could pass a pointer to this data as argument to _all_
6363 functions, but this would bloat the code. Instead we use a feature of
6364 the GCC compiler (Global Register Variables) to share the data: we
6365 place a pointer (gd) to the global data into a register which we
6366 reserve for this purpose.
6368 When choosing a register for such a purpose we are restricted by the
6369 relevant (E)ABI specifications for the current architecture, and by
6370 GCC's implementation.
6372 For PowerPC, the following registers have specific use:
6374 R2: reserved for system use
6375 R3-R4: parameter passing and return values
6376 R5-R10: parameter passing
6377 R13: small data area pointer
6381 (U-Boot also uses R12 as internal GOT pointer. r12
6382 is a volatile register so r12 needs to be reset when
6383 going back and forth between asm and C)
6385 ==> U-Boot will use R2 to hold a pointer to the global data
6387 Note: on PPC, we could use a static initializer (since the
6388 address of the global data structure is known at compile time),
6389 but it turned out that reserving a register results in somewhat
6390 smaller code - although the code savings are not that big (on
6391 average for all boards 752 bytes for the whole U-Boot image,
6392 624 text + 127 data).
6394 On Blackfin, the normal C ABI (except for P3) is followed as documented here:
6395 http://docs.blackfin.uclinux.org/doku.php?id=application_binary_interface
6397 ==> U-Boot will use P3 to hold a pointer to the global data
6399 On ARM, the following registers are used:
6401 R0: function argument word/integer result
6402 R1-R3: function argument word
6403 R9: platform specific
6404 R10: stack limit (used only if stack checking is enabled)
6405 R11: argument (frame) pointer
6406 R12: temporary workspace
6409 R15: program counter
6411 ==> U-Boot will use R9 to hold a pointer to the global data
6413 Note: on ARM, only R_ARM_RELATIVE relocations are supported.
6415 On Nios II, the ABI is documented here:
6416 http://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf
6418 ==> U-Boot will use gp to hold a pointer to the global data
6420 Note: on Nios II, we give "-G0" option to gcc and don't use gp
6421 to access small data sections, so gp is free.
6423 On NDS32, the following registers are used:
6425 R0-R1: argument/return
6427 R15: temporary register for assembler
6428 R16: trampoline register
6429 R28: frame pointer (FP)
6430 R29: global pointer (GP)
6431 R30: link register (LP)
6432 R31: stack pointer (SP)
6433 PC: program counter (PC)
6435 ==> U-Boot will use R10 to hold a pointer to the global data
6437 NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope,
6438 or current versions of GCC may "optimize" the code too much.
6443 U-Boot runs in system state and uses physical addresses, i.e. the
6444 MMU is not used either for address mapping nor for memory protection.
6446 The available memory is mapped to fixed addresses using the memory
6447 controller. In this process, a contiguous block is formed for each
6448 memory type (Flash, SDRAM, SRAM), even when it consists of several
6449 physical memory banks.
6451 U-Boot is installed in the first 128 kB of the first Flash bank (on
6452 TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
6453 booting and sizing and initializing DRAM, the code relocates itself
6454 to the upper end of DRAM. Immediately below the U-Boot code some
6455 memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN
6456 configuration setting]. Below that, a structure with global Board
6457 Info data is placed, followed by the stack (growing downward).
6459 Additionally, some exception handler code is copied to the low 8 kB
6460 of DRAM (0x00000000 ... 0x00001FFF).
6462 So a typical memory configuration with 16 MB of DRAM could look like
6465 0x0000 0000 Exception Vector code
6468 0x0000 2000 Free for Application Use
6474 0x00FB FF20 Monitor Stack (Growing downward)
6475 0x00FB FFAC Board Info Data and permanent copy of global data
6476 0x00FC 0000 Malloc Arena
6479 0x00FE 0000 RAM Copy of Monitor Code
6480 ... eventually: LCD or video framebuffer
6481 ... eventually: pRAM (Protected RAM - unchanged by reset)
6482 0x00FF FFFF [End of RAM]
6485 System Initialization:
6486 ----------------------
6488 In the reset configuration, U-Boot starts at the reset entry point
6489 (on most PowerPC systems at address 0x00000100). Because of the reset
6490 configuration for CS0# this is a mirror of the on board Flash memory.
6491 To be able to re-map memory U-Boot then jumps to its link address.
6492 To be able to implement the initialization code in C, a (small!)
6493 initial stack is set up in the internal Dual Ported RAM (in case CPUs
6494 which provide such a feature like MPC8xx or MPC8260), or in a locked
6495 part of the data cache. After that, U-Boot initializes the CPU core,
6496 the caches and the SIU.
6498 Next, all (potentially) available memory banks are mapped using a
6499 preliminary mapping. For example, we put them on 512 MB boundaries
6500 (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
6501 on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
6502 programmed for SDRAM access. Using the temporary configuration, a
6503 simple memory test is run that determines the size of the SDRAM
6506 When there is more than one SDRAM bank, and the banks are of
6507 different size, the largest is mapped first. For equal size, the first
6508 bank (CS2#) is mapped first. The first mapping is always for address
6509 0x00000000, with any additional banks following immediately to create
6510 contiguous memory starting from 0.
6512 Then, the monitor installs itself at the upper end of the SDRAM area
6513 and allocates memory for use by malloc() and for the global Board
6514 Info data; also, the exception vector code is copied to the low RAM
6515 pages, and the final stack is set up.
6517 Only after this relocation will you have a "normal" C environment;
6518 until that you are restricted in several ways, mostly because you are
6519 running from ROM, and because the code will have to be relocated to a
6523 U-Boot Porting Guide:
6524 ----------------------
6526 [Based on messages by Jerry Van Baren in the U-Boot-Users mailing
6530 int main(int argc, char *argv[])
6532 sighandler_t no_more_time;
6534 signal(SIGALRM, no_more_time);
6535 alarm(PROJECT_DEADLINE - toSec (3 * WEEK));
6537 if (available_money > available_manpower) {
6538 Pay consultant to port U-Boot;
6542 Download latest U-Boot source;
6544 Subscribe to u-boot mailing list;
6547 email("Hi, I am new to U-Boot, how do I get started?");
6550 Read the README file in the top level directory;
6551 Read http://www.denx.de/twiki/bin/view/DULG/Manual;
6552 Read applicable doc/*.README;
6553 Read the source, Luke;
6554 /* find . -name "*.[chS]" | xargs grep -i <keyword> */
6557 if (available_money > toLocalCurrency ($2500))
6560 Add a lot of aggravation and time;
6562 if (a similar board exists) { /* hopefully... */
6563 cp -a board/<similar> board/<myboard>
6564 cp include/configs/<similar>.h include/configs/<myboard>.h
6566 Create your own board support subdirectory;
6567 Create your own board include/configs/<myboard>.h file;
6569 Edit new board/<myboard> files
6570 Edit new include/configs/<myboard>.h
6575 Add / modify source code;
6579 email("Hi, I am having problems...");
6581 Send patch file to the U-Boot email list;
6582 if (reasonable critiques)
6583 Incorporate improvements from email list code review;
6585 Defend code as written;
6591 void no_more_time (int sig)
6600 All contributions to U-Boot should conform to the Linux kernel
6601 coding style; see the file "Documentation/CodingStyle" and the script
6602 "scripts/Lindent" in your Linux kernel source directory.
6604 Source files originating from a different project (for example the
6605 MTD subsystem) are generally exempt from these guidelines and are not
6606 reformatted to ease subsequent migration to newer versions of those
6609 Please note that U-Boot is implemented in C (and to some small parts in
6610 Assembler); no C++ is used, so please do not use C++ style comments (//)
6613 Please also stick to the following formatting rules:
6614 - remove any trailing white space
6615 - use TAB characters for indentation and vertical alignment, not spaces
6616 - make sure NOT to use DOS '\r\n' line feeds
6617 - do not add more than 2 consecutive empty lines to source files
6618 - do not add trailing empty lines to source files
6620 Submissions which do not conform to the standards may be returned
6621 with a request to reformat the changes.
6627 Since the number of patches for U-Boot is growing, we need to
6628 establish some rules. Submissions which do not conform to these rules
6629 may be rejected, even when they contain important and valuable stuff.
6631 Please see http://www.denx.de/wiki/U-Boot/Patches for details.
6634 see http://lists.denx.de/mailman/listinfo/u-boot
6636 When you send a patch, please include the following information with
6639 * For bug fixes: a description of the bug and how your patch fixes
6640 this bug. Please try to include a way of demonstrating that the
6641 patch actually fixes something.
6643 * For new features: a description of the feature and your
6646 * A CHANGELOG entry as plaintext (separate from the patch)
6648 * For major contributions, your entry to the CREDITS file
6650 * When you add support for a new board, don't forget to add a
6651 maintainer e-mail address to the boards.cfg file, too.
6653 * If your patch adds new configuration options, don't forget to
6654 document these in the README file.
6656 * The patch itself. If you are using git (which is *strongly*
6657 recommended) you can easily generate the patch using the
6658 "git format-patch". If you then use "git send-email" to send it to
6659 the U-Boot mailing list, you will avoid most of the common problems
6660 with some other mail clients.
6662 If you cannot use git, use "diff -purN OLD NEW". If your version of
6663 diff does not support these options, then get the latest version of
6666 The current directory when running this command shall be the parent
6667 directory of the U-Boot source tree (i. e. please make sure that
6668 your patch includes sufficient directory information for the
6671 We prefer patches as plain text. MIME attachments are discouraged,
6672 and compressed attachments must not be used.
6674 * If one logical set of modifications affects or creates several
6675 files, all these changes shall be submitted in a SINGLE patch file.
6677 * Changesets that contain different, unrelated modifications shall be
6678 submitted as SEPARATE patches, one patch per changeset.
6683 * Before sending the patch, run the MAKEALL script on your patched
6684 source tree and make sure that no errors or warnings are reported
6685 for any of the boards.
6687 * Keep your modifications to the necessary minimum: A patch
6688 containing several unrelated changes or arbitrary reformats will be
6689 returned with a request to re-formatting / split it.
6691 * If you modify existing code, make sure that your new code does not
6692 add to the memory footprint of the code ;-) Small is beautiful!
6693 When adding new features, these should compile conditionally only
6694 (using #ifdef), and the resulting code with the new feature
6695 disabled must not need more memory than the old code without your
6698 * Remember that there is a size limit of 100 kB per message on the
6699 u-boot mailing list. Bigger patches will be moderated. If they are
6700 reasonable and not too big, they will be acknowledged. But patches
6701 bigger than the size limit should be avoided.
projects / u-boot.git / blob