2 # (C) Copyright 2000 - 2013
3 # Wolfgang Denk, DENX Software Engineering, wd@denx.de.
5 # SPDX-License-Identifier: GPL-2.0+
11 This directory contains the source code for U-Boot, a boot loader for
12 Embedded boards based on PowerPC, ARM, MIPS and several other
13 processors, which can be installed in a boot ROM and used to
14 initialize and test the hardware or to download and run application
17 The development of U-Boot is closely related to Linux: some parts of
18 the source code originate in the Linux source tree, we have some
19 header files in common, and special provision has been made to
20 support booting of Linux images.
22 Some attention has been paid to make this software easily
23 configurable and extendable. For instance, all monitor commands are
24 implemented with the same call interface, so that it's very easy to
25 add new commands. Also, instead of permanently adding rarely used
26 code (for instance hardware test utilities) to the monitor, you can
27 load and run it dynamically.
33 In general, all boards for which a configuration option exists in the
34 Makefile have been tested to some extent and can be considered
35 "working". In fact, many of them are used in production systems.
37 In case of problems see the CHANGELOG and CREDITS files to find out
38 who contributed the specific port. The boards.cfg file lists board
41 Note: There is no CHANGELOG file in the actual U-Boot source tree;
42 it can be created dynamically from the Git log using:
50 In case you have questions about, problems with or contributions for
51 U-Boot you should send a message to the U-Boot mailing list at
52 <u-boot@lists.denx.de>. There is also an archive of previous traffic
53 on the mailing list - please search the archive before asking FAQ's.
54 Please see http://lists.denx.de/pipermail/u-boot and
55 http://dir.gmane.org/gmane.comp.boot-loaders.u-boot
58 Where to get source code:
59 =========================
61 The U-Boot source code is maintained in the git repository at
62 git://www.denx.de/git/u-boot.git ; you can browse it online at
63 http://www.denx.de/cgi-bin/gitweb.cgi?p=u-boot.git;a=summary
65 The "snapshot" links on this page allow you to download tarballs of
66 any version you might be interested in. Official releases are also
67 available for FTP download from the ftp://ftp.denx.de/pub/u-boot/
70 Pre-built (and tested) images are available from
71 ftp://ftp.denx.de/pub/u-boot/images/
77 - start from 8xxrom sources
78 - create PPCBoot project (http://sourceforge.net/projects/ppcboot)
80 - make it easier to add custom boards
81 - make it possible to add other [PowerPC] CPUs
82 - extend functions, especially:
83 * Provide extended interface to Linux boot loader
86 * PCMCIA / CompactFlash / ATA disk / SCSI ... boot
87 - create ARMBoot project (http://sourceforge.net/projects/armboot)
88 - add other CPU families (starting with ARM)
89 - create U-Boot project (http://sourceforge.net/projects/u-boot)
90 - current project page: see http://www.denx.de/wiki/U-Boot
96 The "official" name of this project is "Das U-Boot". The spelling
97 "U-Boot" shall be used in all written text (documentation, comments
98 in source files etc.). Example:
100 This is the README file for the U-Boot project.
102 File names etc. shall be based on the string "u-boot". Examples:
104 include/asm-ppc/u-boot.h
106 #include <asm/u-boot.h>
108 Variable names, preprocessor constants etc. shall be either based on
109 the string "u_boot" or on "U_BOOT". Example:
111 U_BOOT_VERSION u_boot_logo
112 IH_OS_U_BOOT u_boot_hush_start
118 Starting with the release in October 2008, the names of the releases
119 were changed from numerical release numbers without deeper meaning
120 into a time stamp based numbering. Regular releases are identified by
121 names consisting of the calendar year and month of the release date.
122 Additional fields (if present) indicate release candidates or bug fix
123 releases in "stable" maintenance trees.
126 U-Boot v2009.11 - Release November 2009
127 U-Boot v2009.11.1 - Release 1 in version November 2009 stable tree
128 U-Boot v2010.09-rc1 - Release candiate 1 for September 2010 release
134 /arch Architecture specific files
135 /arc Files generic to ARC architecture
136 /cpu CPU specific files
137 /arc700 Files specific to ARC 700 CPUs
138 /lib Architecture specific library files
139 /arm Files generic to ARM architecture
140 /cpu CPU specific files
141 /arm720t Files specific to ARM 720 CPUs
142 /arm920t Files specific to ARM 920 CPUs
143 /at91 Files specific to Atmel AT91RM9200 CPU
144 /imx Files specific to Freescale MC9328 i.MX CPUs
145 /s3c24x0 Files specific to Samsung S3C24X0 CPUs
146 /arm926ejs Files specific to ARM 926 CPUs
147 /arm1136 Files specific to ARM 1136 CPUs
148 /pxa Files specific to Intel XScale PXA CPUs
149 /sa1100 Files specific to Intel StrongARM SA1100 CPUs
150 /lib Architecture specific library files
151 /avr32 Files generic to AVR32 architecture
152 /cpu CPU specific files
153 /lib Architecture specific library files
154 /blackfin Files generic to Analog Devices Blackfin architecture
155 /cpu CPU specific files
156 /lib Architecture specific library files
157 /m68k Files generic to m68k architecture
158 /cpu CPU specific files
159 /mcf52x2 Files specific to Freescale ColdFire MCF52x2 CPUs
160 /mcf5227x Files specific to Freescale ColdFire MCF5227x CPUs
161 /mcf532x Files specific to Freescale ColdFire MCF5329 CPUs
162 /mcf5445x Files specific to Freescale ColdFire MCF5445x CPUs
163 /mcf547x_8x Files specific to Freescale ColdFire MCF547x_8x CPUs
164 /lib Architecture specific library files
165 /microblaze Files generic to microblaze architecture
166 /cpu CPU specific files
167 /lib Architecture specific library files
168 /mips Files generic to MIPS architecture
169 /cpu CPU specific files
170 /mips32 Files specific to MIPS32 CPUs
171 /mips64 Files specific to MIPS64 CPUs
172 /lib Architecture specific library files
173 /nds32 Files generic to NDS32 architecture
174 /cpu CPU specific files
175 /n1213 Files specific to Andes Technology N1213 CPUs
176 /lib Architecture specific library files
177 /nios2 Files generic to Altera NIOS2 architecture
178 /cpu CPU specific files
179 /lib Architecture specific library files
180 /openrisc Files generic to OpenRISC architecture
181 /cpu CPU specific files
182 /lib Architecture specific library files
183 /powerpc Files generic to PowerPC architecture
184 /cpu CPU specific files
185 /mpc5xx Files specific to Freescale MPC5xx CPUs
186 /mpc5xxx Files specific to Freescale MPC5xxx CPUs
187 /mpc8xx Files specific to Freescale MPC8xx CPUs
188 /mpc8260 Files specific to Freescale MPC8260 CPUs
189 /mpc85xx Files specific to Freescale MPC85xx CPUs
190 /ppc4xx Files specific to AMCC PowerPC 4xx CPUs
191 /lib Architecture specific library files
192 /sh Files generic to SH architecture
193 /cpu CPU specific files
194 /sh2 Files specific to sh2 CPUs
195 /sh3 Files specific to sh3 CPUs
196 /sh4 Files specific to sh4 CPUs
197 /lib Architecture specific library files
198 /sparc Files generic to SPARC architecture
199 /cpu CPU specific files
200 /leon2 Files specific to Gaisler LEON2 SPARC CPU
201 /leon3 Files specific to Gaisler LEON3 SPARC CPU
202 /lib Architecture specific library files
203 /x86 Files generic to x86 architecture
204 /cpu CPU specific files
205 /lib Architecture specific library files
206 /api Machine/arch independent API for external apps
207 /board Board dependent files
208 /common Misc architecture independent functions
209 /disk Code for disk drive partition handling
210 /doc Documentation (don't expect too much)
211 /drivers Commonly used device drivers
212 /dts Contains Makefile for building internal U-Boot fdt.
213 /examples Example code for standalone applications, etc.
214 /fs Filesystem code (cramfs, ext2, jffs2, etc.)
215 /include Header Files
216 /lib Files generic to all architectures
217 /libfdt Library files to support flattened device trees
218 /lzma Library files to support LZMA decompression
219 /lzo Library files to support LZO decompression
221 /post Power On Self Test
222 /spl Secondary Program Loader framework
223 /tools Tools to build S-Record or U-Boot images, etc.
225 Software Configuration:
226 =======================
228 Configuration is usually done using C preprocessor defines; the
229 rationale behind that is to avoid dead code whenever possible.
231 There are two classes of configuration variables:
233 * Configuration _OPTIONS_:
234 These are selectable by the user and have names beginning with
237 * Configuration _SETTINGS_:
238 These depend on the hardware etc. and should not be meddled with if
239 you don't know what you're doing; they have names beginning with
242 Later we will add a configuration tool - probably similar to or even
243 identical to what's used for the Linux kernel. Right now, we have to
244 do the configuration by hand, which means creating some symbolic
245 links and editing some configuration files. We use the TQM8xxL boards
249 Selection of Processor Architecture and Board Type:
250 ---------------------------------------------------
252 For all supported boards there are ready-to-use default
253 configurations available; just type "make <board_name>_defconfig".
255 Example: For a TQM823L module type:
258 make TQM823L_defconfig
260 For the Cogent platform, you need to specify the CPU type as well;
261 e.g. "make cogent_mpc8xx_defconfig". And also configure the cogent
262 directory according to the instructions in cogent/README.
268 U-Boot can be built natively to run on a Linux host using the 'sandbox'
269 board. This allows feature development which is not board- or architecture-
270 specific to be undertaken on a native platform. The sandbox is also used to
271 run some of U-Boot's tests.
273 See board/sandbox/README.sandbox for more details.
276 Board Initialisation Flow:
277 --------------------------
279 This is the intended start-up flow for boards. This should apply for both
280 SPL and U-Boot proper (i.e. they both follow the same rules). At present SPL
281 mostly uses a separate code path, but the funtion names and roles of each
282 function are the same. Some boards or architectures may not conform to this.
283 At least most ARM boards which use CONFIG_SPL_FRAMEWORK conform to this.
285 Execution starts with start.S with three functions called during init after
286 that. The purpose and limitations of each is described below.
289 - purpose: essential init to permit execution to reach board_init_f()
290 - no global_data or BSS
291 - there is no stack (ARMv7 may have one but it will soon be removed)
292 - must not set up SDRAM or use console
293 - must only do the bare minimum to allow execution to continue to
295 - this is almost never needed
296 - return normally from this function
299 - purpose: set up the machine ready for running board_init_r():
300 i.e. SDRAM and serial UART
301 - global_data is available
303 - BSS is not available, so you cannot use global/static variables,
304 only stack variables and global_data
306 Non-SPL-specific notes:
307 - dram_init() is called to set up DRAM. If already done in SPL this
311 - you can override the entire board_init_f() function with your own
313 - preloader_console_init() can be called here in extremis
314 - should set up SDRAM, and anything needed to make the UART work
315 - these is no need to clear BSS, it will be done by crt0.S
316 - must return normally from this function (don't call board_init_r()
319 Here the BSS is cleared. For SPL, if CONFIG_SPL_STACK_R is defined, then at
320 this point the stack and global_data are relocated to below
321 CONFIG_SPL_STACK_R_ADDR. For non-SPL, U-Boot is relocated to run at the top of
325 - purpose: main execution, common code
326 - global_data is available
328 - BSS is available, all static/global variables can be used
329 - execution eventually continues to main_loop()
331 Non-SPL-specific notes:
332 - U-Boot is relocated to the top of memory and is now running from
336 - stack is optionally in SDRAM, if CONFIG_SPL_STACK_R is defined and
337 CONFIG_SPL_STACK_R_ADDR points into SDRAM
338 - preloader_console_init() can be called here - typically this is
339 done by defining CONFIG_SPL_BOARD_INIT and then supplying a
340 spl_board_init() function containing this call
341 - loads U-Boot or (in falcon mode) Linux
345 Configuration Options:
346 ----------------------
348 Configuration depends on the combination of board and CPU type; all
349 such information is kept in a configuration file
350 "include/configs/<board_name>.h".
352 Example: For a TQM823L module, all configuration settings are in
353 "include/configs/TQM823L.h".
356 Many of the options are named exactly as the corresponding Linux
357 kernel configuration options. The intention is to make it easier to
358 build a config tool - later.
361 The following options need to be configured:
363 - CPU Type: Define exactly one, e.g. CONFIG_MPC85XX.
365 - Board Type: Define exactly one, e.g. CONFIG_MPC8540ADS.
367 - CPU Daughterboard Type: (if CONFIG_ATSTK1000 is defined)
368 Define exactly one, e.g. CONFIG_ATSTK1002
370 - CPU Module Type: (if CONFIG_COGENT is defined)
371 Define exactly one of
373 --- FIXME --- not tested yet:
374 CONFIG_CMA286_60, CONFIG_CMA286_21, CONFIG_CMA286_60P,
375 CONFIG_CMA287_23, CONFIG_CMA287_50
377 - Motherboard Type: (if CONFIG_COGENT is defined)
378 Define exactly one of
379 CONFIG_CMA101, CONFIG_CMA102
381 - Motherboard I/O Modules: (if CONFIG_COGENT is defined)
382 Define one or more of
385 - Motherboard Options: (if CONFIG_CMA101 or CONFIG_CMA102 are defined)
386 Define one or more of
387 CONFIG_LCD_HEARTBEAT - update a character position on
388 the LCD display every second with
391 - Marvell Family Member
392 CONFIG_SYS_MVFS - define it if you want to enable
393 multiple fs option at one time
394 for marvell soc family
396 - 8xx CPU Options: (if using an MPC8xx CPU)
397 CONFIG_8xx_GCLK_FREQ - deprecated: CPU clock if
398 get_gclk_freq() cannot work
399 e.g. if there is no 32KHz
400 reference PIT/RTC clock
401 CONFIG_8xx_OSCLK - PLL input clock (either EXTCLK
404 - 859/866/885 CPU options: (if using a MPC859 or MPC866 or MPC885 CPU):
405 CONFIG_SYS_8xx_CPUCLK_MIN
406 CONFIG_SYS_8xx_CPUCLK_MAX
407 CONFIG_8xx_CPUCLK_DEFAULT
408 See doc/README.MPC866
410 CONFIG_SYS_MEASURE_CPUCLK
412 Define this to measure the actual CPU clock instead
413 of relying on the correctness of the configured
414 values. Mostly useful for board bringup to make sure
415 the PLL is locked at the intended frequency. Note
416 that this requires a (stable) reference clock (32 kHz
417 RTC clock or CONFIG_SYS_8XX_XIN)
419 CONFIG_SYS_DELAYED_ICACHE
421 Define this option if you want to enable the
422 ICache only when Code runs from RAM.
427 Specifies that the core is a 64-bit PowerPC implementation (implements
428 the "64" category of the Power ISA). This is necessary for ePAPR
429 compliance, among other possible reasons.
431 CONFIG_SYS_FSL_TBCLK_DIV
433 Defines the core time base clock divider ratio compared to the
434 system clock. On most PQ3 devices this is 8, on newer QorIQ
435 devices it can be 16 or 32. The ratio varies from SoC to Soc.
437 CONFIG_SYS_FSL_PCIE_COMPAT
439 Defines the string to utilize when trying to match PCIe device
440 tree nodes for the given platform.
442 CONFIG_SYS_PPC_E500_DEBUG_TLB
444 Enables a temporary TLB entry to be used during boot to work
445 around limitations in e500v1 and e500v2 external debugger
446 support. This reduces the portions of the boot code where
447 breakpoints and single stepping do not work. The value of this
448 symbol should be set to the TLB1 entry to be used for this
451 CONFIG_SYS_FSL_ERRATUM_A004510
453 Enables a workaround for erratum A004510. If set,
454 then CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV and
455 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY must be set.
457 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV
458 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV2 (optional)
460 Defines one or two SoC revisions (low 8 bits of SVR)
461 for which the A004510 workaround should be applied.
463 The rest of SVR is either not relevant to the decision
464 of whether the erratum is present (e.g. p2040 versus
465 p2041) or is implied by the build target, which controls
466 whether CONFIG_SYS_FSL_ERRATUM_A004510 is set.
468 See Freescale App Note 4493 for more information about
471 CONFIG_A003399_NOR_WORKAROUND
472 Enables a workaround for IFC erratum A003399. It is only
473 required during NOR boot.
475 CONFIG_A008044_WORKAROUND
476 Enables a workaround for T1040/T1042 erratum A008044. It is only
477 required during NAND boot and valid for Rev 1.0 SoC revision
479 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY
481 This is the value to write into CCSR offset 0x18600
482 according to the A004510 workaround.
484 CONFIG_SYS_FSL_DSP_DDR_ADDR
485 This value denotes start offset of DDR memory which is
486 connected exclusively to the DSP cores.
488 CONFIG_SYS_FSL_DSP_M2_RAM_ADDR
489 This value denotes start offset of M2 memory
490 which is directly connected to the DSP core.
492 CONFIG_SYS_FSL_DSP_M3_RAM_ADDR
493 This value denotes start offset of M3 memory which is directly
494 connected to the DSP core.
496 CONFIG_SYS_FSL_DSP_CCSRBAR_DEFAULT
497 This value denotes start offset of DSP CCSR space.
499 CONFIG_SYS_FSL_SINGLE_SOURCE_CLK
500 Single Source Clock is clocking mode present in some of FSL SoC's.
501 In this mode, a single differential clock is used to supply
502 clocks to the sysclock, ddrclock and usbclock.
504 CONFIG_SYS_CPC_REINIT_F
505 This CONFIG is defined when the CPC is configured as SRAM at the
506 time of U-boot entry and is required to be re-initialized.
509 Indicates this SoC supports deep sleep feature. If deep sleep is
510 supported, core will start to execute uboot when wakes up.
512 - Generic CPU options:
513 CONFIG_SYS_GENERIC_GLOBAL_DATA
514 Defines global data is initialized in generic board board_init_f().
515 If this macro is defined, global data is created and cleared in
516 generic board board_init_f(). Without this macro, architecture/board
517 should initialize global data before calling board_init_f().
519 CONFIG_SYS_BIG_ENDIAN, CONFIG_SYS_LITTLE_ENDIAN
521 Defines the endianess of the CPU. Implementation of those
522 values is arch specific.
525 Freescale DDR driver in use. This type of DDR controller is
526 found in mpc83xx, mpc85xx, mpc86xx as well as some ARM core
529 CONFIG_SYS_FSL_DDR_ADDR
530 Freescale DDR memory-mapped register base.
532 CONFIG_SYS_FSL_DDR_EMU
533 Specify emulator support for DDR. Some DDR features such as
534 deskew training are not available.
536 CONFIG_SYS_FSL_DDRC_GEN1
537 Freescale DDR1 controller.
539 CONFIG_SYS_FSL_DDRC_GEN2
540 Freescale DDR2 controller.
542 CONFIG_SYS_FSL_DDRC_GEN3
543 Freescale DDR3 controller.
545 CONFIG_SYS_FSL_DDRC_GEN4
546 Freescale DDR4 controller.
548 CONFIG_SYS_FSL_DDRC_ARM_GEN3
549 Freescale DDR3 controller for ARM-based SoCs.
552 Board config to use DDR1. It can be enabled for SoCs with
553 Freescale DDR1 or DDR2 controllers, depending on the board
557 Board config to use DDR2. It can be eanbeld for SoCs with
558 Freescale DDR2 or DDR3 controllers, depending on the board
562 Board config to use DDR3. It can be enabled for SoCs with
563 Freescale DDR3 or DDR3L controllers.
566 Board config to use DDR3L. It can be enabled for SoCs with
570 Board config to use DDR4. It can be enabled for SoCs with
573 CONFIG_SYS_FSL_IFC_BE
574 Defines the IFC controller register space as Big Endian
576 CONFIG_SYS_FSL_IFC_LE
577 Defines the IFC controller register space as Little Endian
579 CONFIG_SYS_FSL_PBL_PBI
580 It enables addition of RCW (Power on reset configuration) in built image.
581 Please refer doc/README.pblimage for more details
583 CONFIG_SYS_FSL_PBL_RCW
584 It adds PBI(pre-boot instructions) commands in u-boot build image.
585 PBI commands can be used to configure SoC before it starts the execution.
586 Please refer doc/README.pblimage for more details
589 It adds a target to create boot binary having SPL binary in PBI format
590 concatenated with u-boot binary.
592 CONFIG_SYS_FSL_DDR_BE
593 Defines the DDR controller register space as Big Endian
595 CONFIG_SYS_FSL_DDR_LE
596 Defines the DDR controller register space as Little Endian
598 CONFIG_SYS_FSL_DDR_SDRAM_BASE_PHY
599 Physical address from the view of DDR controllers. It is the
600 same as CONFIG_SYS_DDR_SDRAM_BASE for all Power SoCs. But
601 it could be different for ARM SoCs.
603 CONFIG_SYS_FSL_DDR_INTLV_256B
604 DDR controller interleaving on 256-byte. This is a special
605 interleaving mode, handled by Dickens for Freescale layerscape
608 CONFIG_SYS_FSL_DDR_MAIN_NUM_CTRLS
609 Number of controllers used as main memory.
611 CONFIG_SYS_FSL_OTHER_DDR_NUM_CTRLS
612 Number of controllers used for other than main memory.
614 CONFIG_SYS_FSL_SEC_BE
615 Defines the SEC controller register space as Big Endian
617 CONFIG_SYS_FSL_SEC_LE
618 Defines the SEC controller register space as Little Endian
620 - Intel Monahans options:
621 CONFIG_SYS_MONAHANS_RUN_MODE_OSC_RATIO
623 Defines the Monahans run mode to oscillator
624 ratio. Valid values are 8, 16, 24, 31. The core
625 frequency is this value multiplied by 13 MHz.
627 CONFIG_SYS_MONAHANS_TURBO_RUN_MODE_RATIO
629 Defines the Monahans turbo mode to oscillator
630 ratio. Valid values are 1 (default if undefined) and
631 2. The core frequency as calculated above is multiplied
635 CONFIG_SYS_INIT_SP_OFFSET
637 Offset relative to CONFIG_SYS_SDRAM_BASE for initial stack
638 pointer. This is needed for the temporary stack before
641 CONFIG_SYS_MIPS_CACHE_MODE
643 Cache operation mode for the MIPS CPU.
644 See also arch/mips/include/asm/mipsregs.h.
646 CONF_CM_CACHABLE_NO_WA
649 CONF_CM_CACHABLE_NONCOHERENT
653 CONF_CM_CACHABLE_ACCELERATED
655 CONFIG_SYS_XWAY_EBU_BOOTCFG
657 Special option for Lantiq XWAY SoCs for booting from NOR flash.
658 See also arch/mips/cpu/mips32/start.S.
660 CONFIG_XWAY_SWAP_BYTES
662 Enable compilation of tools/xway-swap-bytes needed for Lantiq
663 XWAY SoCs for booting from NOR flash. The U-Boot image needs to
664 be swapped if a flash programmer is used.
667 CONFIG_SYS_EXCEPTION_VECTORS_HIGH
669 Select high exception vectors of the ARM core, e.g., do not
670 clear the V bit of the c1 register of CP15.
672 CONFIG_SYS_THUMB_BUILD
674 Use this flag to build U-Boot using the Thumb instruction
675 set for ARM architectures. Thumb instruction set provides
676 better code density. For ARM architectures that support
677 Thumb2 this flag will result in Thumb2 code generated by
680 CONFIG_ARM_ERRATA_716044
681 CONFIG_ARM_ERRATA_742230
682 CONFIG_ARM_ERRATA_743622
683 CONFIG_ARM_ERRATA_751472
684 CONFIG_ARM_ERRATA_794072
685 CONFIG_ARM_ERRATA_761320
687 If set, the workarounds for these ARM errata are applied early
688 during U-Boot startup. Note that these options force the
689 workarounds to be applied; no CPU-type/version detection
690 exists, unlike the similar options in the Linux kernel. Do not
691 set these options unless they apply!
694 Generic timer clock source frequency.
696 COUNTER_FREQUENCY_REAL
697 Generic timer clock source frequency if the real clock is
698 different from COUNTER_FREQUENCY, and can only be determined
701 NOTE: The following can be machine specific errata. These
702 do have ability to provide rudimentary version and machine
703 specific checks, but expect no product checks.
704 CONFIG_ARM_ERRATA_430973
705 CONFIG_ARM_ERRATA_454179
706 CONFIG_ARM_ERRATA_621766
707 CONFIG_ARM_ERRATA_798870
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.
1386 Support for Intel 82557/82559/82559ER chips.
1387 Optional CONFIG_EEPRO100_SROM_WRITE enables EEPROM
1388 write routine for first time initialisation.
1391 Support for Digital 2114x chips.
1392 Optional CONFIG_TULIP_SELECT_MEDIA for board specific
1393 modem chip initialisation (KS8761/QS6611).
1396 Support for National dp83815 chips.
1399 Support for National dp8382[01] gigabit chips.
1401 - NETWORK Support (other):
1403 CONFIG_DRIVER_AT91EMAC
1404 Support for AT91RM9200 EMAC.
1407 Define this to use reduced MII inteface
1409 CONFIG_DRIVER_AT91EMAC_QUIET
1410 If this defined, the driver is quiet.
1411 The driver doen't show link status messages.
1413 CONFIG_CALXEDA_XGMAC
1414 Support for the Calxeda XGMAC device
1417 Support for SMSC's LAN91C96 chips.
1419 CONFIG_LAN91C96_BASE
1420 Define this to hold the physical address
1421 of the LAN91C96's I/O space
1423 CONFIG_LAN91C96_USE_32_BIT
1424 Define this to enable 32 bit addressing
1427 Support for SMSC's LAN91C111 chip
1429 CONFIG_SMC91111_BASE
1430 Define this to hold the physical address
1431 of the device (I/O space)
1433 CONFIG_SMC_USE_32_BIT
1434 Define this if data bus is 32 bits
1436 CONFIG_SMC_USE_IOFUNCS
1437 Define this to use i/o functions instead of macros
1438 (some hardware wont work with macros)
1440 CONFIG_DRIVER_TI_EMAC
1441 Support for davinci emac
1443 CONFIG_SYS_DAVINCI_EMAC_PHY_COUNT
1444 Define this if you have more then 3 PHYs.
1447 Support for Faraday's FTGMAC100 Gigabit SoC Ethernet
1449 CONFIG_FTGMAC100_EGIGA
1450 Define this to use GE link update with gigabit PHY.
1451 Define this if FTGMAC100 is connected to gigabit PHY.
1452 If your system has 10/100 PHY only, it might not occur
1453 wrong behavior. Because PHY usually return timeout or
1454 useless data when polling gigabit status and gigabit
1455 control registers. This behavior won't affect the
1456 correctnessof 10/100 link speed update.
1459 Support for SMSC's LAN911x and LAN921x chips
1462 Define this to hold the physical address
1463 of the device (I/O space)
1465 CONFIG_SMC911X_32_BIT
1466 Define this if data bus is 32 bits
1468 CONFIG_SMC911X_16_BIT
1469 Define this if data bus is 16 bits. If your processor
1470 automatically converts one 32 bit word to two 16 bit
1471 words you may also try CONFIG_SMC911X_32_BIT.
1474 Support for Renesas on-chip Ethernet controller
1476 CONFIG_SH_ETHER_USE_PORT
1477 Define the number of ports to be used
1479 CONFIG_SH_ETHER_PHY_ADDR
1480 Define the ETH PHY's address
1482 CONFIG_SH_ETHER_CACHE_WRITEBACK
1483 If this option is set, the driver enables cache flush.
1487 Support for PWM modul on the imx6.
1491 Support TPM devices.
1494 Support for i2c bus TPM devices. Only one device
1495 per system is supported at this time.
1497 CONFIG_TPM_TIS_I2C_BUS_NUMBER
1498 Define the the i2c bus number for the TPM device
1500 CONFIG_TPM_TIS_I2C_SLAVE_ADDRESS
1501 Define the TPM's address on the i2c bus
1503 CONFIG_TPM_TIS_I2C_BURST_LIMITATION
1504 Define the burst count bytes upper limit
1506 CONFIG_TPM_ATMEL_TWI
1507 Support for Atmel TWI TPM device. Requires I2C support.
1510 Support for generic parallel port TPM devices. Only one device
1511 per system is supported at this time.
1513 CONFIG_TPM_TIS_BASE_ADDRESS
1514 Base address where the generic TPM device is mapped
1515 to. Contemporary x86 systems usually map it at
1519 Add tpm monitor functions.
1520 Requires CONFIG_TPM. If CONFIG_TPM_AUTH_SESSIONS is set, also
1521 provides monitor access to authorized functions.
1524 Define this to enable the TPM support library which provides
1525 functional interfaces to some TPM commands.
1526 Requires support for a TPM device.
1528 CONFIG_TPM_AUTH_SESSIONS
1529 Define this to enable authorized functions in the TPM library.
1530 Requires CONFIG_TPM and CONFIG_SHA1.
1533 At the moment only the UHCI host controller is
1534 supported (PIP405, MIP405, MPC5200); define
1535 CONFIG_USB_UHCI to enable it.
1536 define CONFIG_USB_KEYBOARD to enable the USB Keyboard
1537 and define CONFIG_USB_STORAGE to enable the USB
1540 Supported are USB Keyboards and USB Floppy drives
1542 MPC5200 USB requires additional defines:
1544 for 528 MHz Clock: 0x0001bbbb
1548 for differential drivers: 0x00001000
1549 for single ended drivers: 0x00005000
1550 for differential drivers on PSC3: 0x00000100
1551 for single ended drivers on PSC3: 0x00004100
1552 CONFIG_SYS_USB_EVENT_POLL
1553 May be defined to allow interrupt polling
1554 instead of using asynchronous interrupts
1556 CONFIG_USB_EHCI_TXFIFO_THRESH enables setting of the
1557 txfilltuning field in the EHCI controller on reset.
1559 CONFIG_USB_DWC2_REG_ADDR the physical CPU address of the DWC2
1560 HW module registers.
1563 Define the below if you wish to use the USB console.
1564 Once firmware is rebuilt from a serial console issue the
1565 command "setenv stdin usbtty; setenv stdout usbtty" and
1566 attach your USB cable. The Unix command "dmesg" should print
1567 it has found a new device. The environment variable usbtty
1568 can be set to gserial or cdc_acm to enable your device to
1569 appear to a USB host as a Linux gserial device or a
1570 Common Device Class Abstract Control Model serial device.
1571 If you select usbtty = gserial you should be able to enumerate
1573 # modprobe usbserial vendor=0xVendorID product=0xProductID
1574 else if using cdc_acm, simply setting the environment
1575 variable usbtty to be cdc_acm should suffice. The following
1576 might be defined in YourBoardName.h
1579 Define this to build a UDC device
1582 Define this to have a tty type of device available to
1583 talk to the UDC device
1586 Define this to enable the high speed support for usb
1587 device and usbtty. If this feature is enabled, a routine
1588 int is_usbd_high_speed(void)
1589 also needs to be defined by the driver to dynamically poll
1590 whether the enumeration has succeded at high speed or full
1593 CONFIG_SYS_CONSOLE_IS_IN_ENV
1594 Define this if you want stdin, stdout &/or stderr to
1598 CONFIG_SYS_USB_EXTC_CLK 0xBLAH
1599 Derive USB clock from external clock "blah"
1600 - CONFIG_SYS_USB_EXTC_CLK 0x02
1602 CONFIG_SYS_USB_BRG_CLK 0xBLAH
1603 Derive USB clock from brgclk
1604 - CONFIG_SYS_USB_BRG_CLK 0x04
1606 If you have a USB-IF assigned VendorID then you may wish to
1607 define your own vendor specific values either in BoardName.h
1608 or directly in usbd_vendor_info.h. If you don't define
1609 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME,
1610 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot
1611 should pretend to be a Linux device to it's target host.
1613 CONFIG_USBD_MANUFACTURER
1614 Define this string as the name of your company for
1615 - CONFIG_USBD_MANUFACTURER "my company"
1617 CONFIG_USBD_PRODUCT_NAME
1618 Define this string as the name of your product
1619 - CONFIG_USBD_PRODUCT_NAME "acme usb device"
1621 CONFIG_USBD_VENDORID
1622 Define this as your assigned Vendor ID from the USB
1623 Implementors Forum. This *must* be a genuine Vendor ID
1624 to avoid polluting the USB namespace.
1625 - CONFIG_USBD_VENDORID 0xFFFF
1627 CONFIG_USBD_PRODUCTID
1628 Define this as the unique Product ID
1630 - CONFIG_USBD_PRODUCTID 0xFFFF
1632 - ULPI Layer Support:
1633 The ULPI (UTMI Low Pin (count) Interface) PHYs are supported via
1634 the generic ULPI layer. The generic layer accesses the ULPI PHY
1635 via the platform viewport, so you need both the genric layer and
1636 the viewport enabled. Currently only Chipidea/ARC based
1637 viewport is supported.
1638 To enable the ULPI layer support, define CONFIG_USB_ULPI and
1639 CONFIG_USB_ULPI_VIEWPORT in your board configuration file.
1640 If your ULPI phy needs a different reference clock than the
1641 standard 24 MHz then you have to define CONFIG_ULPI_REF_CLK to
1642 the appropriate value in Hz.
1645 The MMC controller on the Intel PXA is supported. To
1646 enable this define CONFIG_MMC. The MMC can be
1647 accessed from the boot prompt by mapping the device
1648 to physical memory similar to flash. Command line is
1649 enabled with CONFIG_CMD_MMC. The MMC driver also works with
1650 the FAT fs. This is enabled with CONFIG_CMD_FAT.
1653 Support for Renesas on-chip MMCIF controller
1655 CONFIG_SH_MMCIF_ADDR
1656 Define the base address of MMCIF registers
1659 Define the clock frequency for MMCIF
1662 Enable the generic MMC driver
1664 CONFIG_SUPPORT_EMMC_BOOT
1665 Enable some additional features of the eMMC boot partitions.
1667 CONFIG_SUPPORT_EMMC_RPMB
1668 Enable the commands for reading, writing and programming the
1669 key for the Replay Protection Memory Block partition in eMMC.
1671 - USB Device Firmware Update (DFU) class support:
1672 CONFIG_USB_FUNCTION_DFU
1673 This enables the USB portion of the DFU USB class
1676 This enables the command "dfu" which is used to have
1677 U-Boot create a DFU class device via USB. This command
1678 requires that the "dfu_alt_info" environment variable be
1679 set and define the alt settings to expose to the host.
1682 This enables support for exposing (e)MMC devices via DFU.
1685 This enables support for exposing NAND devices via DFU.
1688 This enables support for exposing RAM via DFU.
1689 Note: DFU spec refer to non-volatile memory usage, but
1690 allow usages beyond the scope of spec - here RAM usage,
1691 one that would help mostly the developer.
1693 CONFIG_SYS_DFU_DATA_BUF_SIZE
1694 Dfu transfer uses a buffer before writing data to the
1695 raw storage device. Make the size (in bytes) of this buffer
1696 configurable. The size of this buffer is also configurable
1697 through the "dfu_bufsiz" environment variable.
1699 CONFIG_SYS_DFU_MAX_FILE_SIZE
1700 When updating files rather than the raw storage device,
1701 we use a static buffer to copy the file into and then write
1702 the buffer once we've been given the whole file. Define
1703 this to the maximum filesize (in bytes) for the buffer.
1704 Default is 4 MiB if undefined.
1706 DFU_DEFAULT_POLL_TIMEOUT
1707 Poll timeout [ms], is the timeout a device can send to the
1708 host. The host must wait for this timeout before sending
1709 a subsequent DFU_GET_STATUS request to the device.
1711 DFU_MANIFEST_POLL_TIMEOUT
1712 Poll timeout [ms], which the device sends to the host when
1713 entering dfuMANIFEST state. Host waits this timeout, before
1714 sending again an USB request to the device.
1716 - USB Device Android Fastboot support:
1717 CONFIG_USB_FUNCTION_FASTBOOT
1718 This enables the USB part of the fastboot gadget
1721 This enables the command "fastboot" which enables the Android
1722 fastboot mode for the platform's USB device. Fastboot is a USB
1723 protocol for downloading images, flashing and device control
1724 used on Android devices.
1725 See doc/README.android-fastboot for more information.
1727 CONFIG_ANDROID_BOOT_IMAGE
1728 This enables support for booting images which use the Android
1729 image format header.
1731 CONFIG_FASTBOOT_BUF_ADDR
1732 The fastboot protocol requires a large memory buffer for
1733 downloads. Define this to the starting RAM address to use for
1736 CONFIG_FASTBOOT_BUF_SIZE
1737 The fastboot protocol requires a large memory buffer for
1738 downloads. This buffer should be as large as possible for a
1739 platform. Define this to the size available RAM for fastboot.
1741 CONFIG_FASTBOOT_FLASH
1742 The fastboot protocol includes a "flash" command for writing
1743 the downloaded image to a non-volatile storage device. Define
1744 this to enable the "fastboot flash" command.
1746 CONFIG_FASTBOOT_FLASH_MMC_DEV
1747 The fastboot "flash" command requires additional information
1748 regarding the non-volatile storage device. Define this to
1749 the eMMC device that fastboot should use to store the image.
1751 CONFIG_FASTBOOT_GPT_NAME
1752 The fastboot "flash" command supports writing the downloaded
1753 image to the Protective MBR and the Primary GUID Partition
1754 Table. (Additionally, this downloaded image is post-processed
1755 to generate and write the Backup GUID Partition Table.)
1756 This occurs when the specified "partition name" on the
1757 "fastboot flash" command line matches this value.
1758 Default is GPT_ENTRY_NAME (currently "gpt") if undefined.
1760 - Journaling Flash filesystem support:
1761 CONFIG_JFFS2_NAND, CONFIG_JFFS2_NAND_OFF, CONFIG_JFFS2_NAND_SIZE,
1762 CONFIG_JFFS2_NAND_DEV
1763 Define these for a default partition on a NAND device
1765 CONFIG_SYS_JFFS2_FIRST_SECTOR,
1766 CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS
1767 Define these for a default partition on a NOR device
1769 CONFIG_SYS_JFFS_CUSTOM_PART
1770 Define this to create an own partition. You have to provide a
1771 function struct part_info* jffs2_part_info(int part_num)
1773 If you define only one JFFS2 partition you may also want to
1774 #define CONFIG_SYS_JFFS_SINGLE_PART 1
1775 to disable the command chpart. This is the default when you
1776 have not defined a custom partition
1778 - FAT(File Allocation Table) filesystem write function support:
1781 Define this to enable support for saving memory data as a
1782 file in FAT formatted partition.
1784 This will also enable the command "fatwrite" enabling the
1785 user to write files to FAT.
1787 CBFS (Coreboot Filesystem) support
1790 Define this to enable support for reading from a Coreboot
1791 filesystem. Available commands are cbfsinit, cbfsinfo, cbfsls
1794 - FAT(File Allocation Table) filesystem cluster size:
1795 CONFIG_FS_FAT_MAX_CLUSTSIZE
1797 Define the max cluster size for fat operations else
1798 a default value of 65536 will be defined.
1803 Define this to enable standard (PC-Style) keyboard
1807 Standard PC keyboard driver with US (is default) and
1808 GERMAN key layout (switch via environment 'keymap=de') support.
1809 Export function i8042_kbd_init, i8042_tstc and i8042_getc
1810 for cfb_console. Supports cursor blinking.
1813 Enables a Chrome OS keyboard using the CROS_EC interface.
1814 This uses CROS_EC to communicate with a second microcontroller
1815 which provides key scans on request.
1820 Define this to enable video support (for output to
1823 CONFIG_VIDEO_CT69000
1825 Enable Chips & Technologies 69000 Video chip
1827 CONFIG_VIDEO_SMI_LYNXEM
1828 Enable Silicon Motion SMI 712/710/810 Video chip. The
1829 video output is selected via environment 'videoout'
1830 (1 = LCD and 2 = CRT). If videoout is undefined, CRT is
1833 For the CT69000 and SMI_LYNXEM drivers, videomode is
1834 selected via environment 'videomode'. Two different ways
1836 - "videomode=num" 'num' is a standard LiLo mode numbers.
1837 Following standard modes are supported (* is default):
1839 Colors 640x480 800x600 1024x768 1152x864 1280x1024
1840 -------------+---------------------------------------------
1841 8 bits | 0x301* 0x303 0x305 0x161 0x307
1842 15 bits | 0x310 0x313 0x316 0x162 0x319
1843 16 bits | 0x311 0x314 0x317 0x163 0x31A
1844 24 bits | 0x312 0x315 0x318 ? 0x31B
1845 -------------+---------------------------------------------
1846 (i.e. setenv videomode 317; saveenv; reset;)
1848 - "videomode=bootargs" all the video parameters are parsed
1849 from the bootargs. (See drivers/video/videomodes.c)
1852 CONFIG_VIDEO_SED13806
1853 Enable Epson SED13806 driver. This driver supports 8bpp
1854 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP
1855 or CONFIG_VIDEO_SED13806_16BPP
1858 Enable the Freescale DIU video driver. Reference boards for
1859 SOCs that have a DIU should define this macro to enable DIU
1860 support, and should also define these other macros:
1866 CONFIG_VIDEO_SW_CURSOR
1867 CONFIG_VGA_AS_SINGLE_DEVICE
1869 CONFIG_VIDEO_BMP_LOGO
1871 The DIU driver will look for the 'video-mode' environment
1872 variable, and if defined, enable the DIU as a console during
1873 boot. See the documentation file README.video for a
1874 description of this variable.
1880 Define this to enable a custom keyboard support.
1881 This simply calls drv_keyboard_init() which must be
1882 defined in your board-specific files.
1883 The only board using this so far is RBC823.
1885 - LCD Support: CONFIG_LCD
1887 Define this to enable LCD support (for output to LCD
1888 display); also select one of the supported displays
1889 by defining one of these:
1893 HITACHI TX09D70VM1CCA, 3.5", 240x320.
1895 CONFIG_NEC_NL6448AC33:
1897 NEC NL6448AC33-18. Active, color, single scan.
1899 CONFIG_NEC_NL6448BC20
1901 NEC NL6448BC20-08. 6.5", 640x480.
1902 Active, color, single scan.
1904 CONFIG_NEC_NL6448BC33_54
1906 NEC NL6448BC33-54. 10.4", 640x480.
1907 Active, color, single scan.
1911 Sharp 320x240. Active, color, single scan.
1912 It isn't 16x9, and I am not sure what it is.
1914 CONFIG_SHARP_LQ64D341
1916 Sharp LQ64D341 display, 640x480.
1917 Active, color, single scan.
1921 HLD1045 display, 640x480.
1922 Active, color, single scan.
1926 Optrex CBL50840-2 NF-FW 99 22 M5
1928 Hitachi LMG6912RPFC-00T
1932 320x240. Black & white.
1934 Normally display is black on white background; define
1935 CONFIG_SYS_WHITE_ON_BLACK to get it inverted.
1937 CONFIG_LCD_ALIGNMENT
1939 Normally the LCD is page-aligned (typically 4KB). If this is
1940 defined then the LCD will be aligned to this value instead.
1941 For ARM it is sometimes useful to use MMU_SECTION_SIZE
1942 here, since it is cheaper to change data cache settings on
1943 a per-section basis.
1945 CONFIG_CONSOLE_SCROLL_LINES
1947 When the console need to be scrolled, this is the number of
1948 lines to scroll by. It defaults to 1. Increasing this makes
1949 the console jump but can help speed up operation when scrolling
1954 Sometimes, for example if the display is mounted in portrait
1955 mode or even if it's mounted landscape but rotated by 180degree,
1956 we need to rotate our content of the display relative to the
1957 framebuffer, so that user can read the messages which are
1959 Once CONFIG_LCD_ROTATION is defined, the lcd_console will be
1960 initialized with a given rotation from "vl_rot" out of
1961 "vidinfo_t" which is provided by the board specific code.
1962 The value for vl_rot is coded as following (matching to
1963 fbcon=rotate:<n> linux-kernel commandline):
1964 0 = no rotation respectively 0 degree
1965 1 = 90 degree rotation
1966 2 = 180 degree rotation
1967 3 = 270 degree rotation
1969 If CONFIG_LCD_ROTATION is not defined, the console will be
1970 initialized with 0degree rotation.
1974 Support drawing of RLE8-compressed bitmaps on the LCD.
1978 Enables an 'i2c edid' command which can read EDID
1979 information over I2C from an attached LCD display.
1981 - Splash Screen Support: CONFIG_SPLASH_SCREEN
1983 If this option is set, the environment is checked for
1984 a variable "splashimage". If found, the usual display
1985 of logo, copyright and system information on the LCD
1986 is suppressed and the BMP image at the address
1987 specified in "splashimage" is loaded instead. The
1988 console is redirected to the "nulldev", too. This
1989 allows for a "silent" boot where a splash screen is
1990 loaded very quickly after power-on.
1992 CONFIG_SPLASHIMAGE_GUARD
1994 If this option is set, then U-Boot will prevent the environment
1995 variable "splashimage" from being set to a problematic address
1996 (see README.displaying-bmps).
1997 This option is useful for targets where, due to alignment
1998 restrictions, an improperly aligned BMP image will cause a data
1999 abort. If you think you will not have problems with unaligned
2000 accesses (for example because your toolchain prevents them)
2001 there is no need to set this option.
2003 CONFIG_SPLASH_SCREEN_ALIGN
2005 If this option is set the splash image can be freely positioned
2006 on the screen. Environment variable "splashpos" specifies the
2007 position as "x,y". If a positive number is given it is used as
2008 number of pixel from left/top. If a negative number is given it
2009 is used as number of pixel from right/bottom. You can also
2010 specify 'm' for centering the image.
2013 setenv splashpos m,m
2014 => image at center of screen
2016 setenv splashpos 30,20
2017 => image at x = 30 and y = 20
2019 setenv splashpos -10,m
2020 => vertically centered image
2021 at x = dspWidth - bmpWidth - 9
2023 - Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP
2025 If this option is set, additionally to standard BMP
2026 images, gzipped BMP images can be displayed via the
2027 splashscreen support or the bmp command.
2029 - Run length encoded BMP image (RLE8) support: CONFIG_VIDEO_BMP_RLE8
2031 If this option is set, 8-bit RLE compressed BMP images
2032 can be displayed via the splashscreen support or the
2035 - Do compressing for memory range:
2038 If this option is set, it would use zlib deflate method
2039 to compress the specified memory at its best effort.
2041 - Compression support:
2044 Enabled by default to support gzip compressed images.
2048 If this option is set, support for bzip2 compressed
2049 images is included. If not, only uncompressed and gzip
2050 compressed images are supported.
2052 NOTE: the bzip2 algorithm requires a lot of RAM, so
2053 the malloc area (as defined by CONFIG_SYS_MALLOC_LEN) should
2058 If this option is set, support for lzma compressed
2061 Note: The LZMA algorithm adds between 2 and 4KB of code and it
2062 requires an amount of dynamic memory that is given by the
2065 (1846 + 768 << (lc + lp)) * sizeof(uint16)
2067 Where lc and lp stand for, respectively, Literal context bits
2068 and Literal pos bits.
2070 This value is upper-bounded by 14MB in the worst case. Anyway,
2071 for a ~4MB large kernel image, we have lc=3 and lp=0 for a
2072 total amount of (1846 + 768 << (3 + 0)) * 2 = ~41KB... that is
2073 a very small buffer.
2075 Use the lzmainfo tool to determinate the lc and lp values and
2076 then calculate the amount of needed dynamic memory (ensuring
2077 the appropriate CONFIG_SYS_MALLOC_LEN value).
2081 If this option is set, support for LZO compressed images
2087 The address of PHY on MII bus.
2089 CONFIG_PHY_CLOCK_FREQ (ppc4xx)
2091 The clock frequency of the MII bus
2095 If this option is set, support for speed/duplex
2096 detection of gigabit PHY is included.
2098 CONFIG_PHY_RESET_DELAY
2100 Some PHY like Intel LXT971A need extra delay after
2101 reset before any MII register access is possible.
2102 For such PHY, set this option to the usec delay
2103 required. (minimum 300usec for LXT971A)
2105 CONFIG_PHY_CMD_DELAY (ppc4xx)
2107 Some PHY like Intel LXT971A need extra delay after
2108 command issued before MII status register can be read
2113 Define a default value for the IP address to use for
2114 the default Ethernet interface, in case this is not
2115 determined through e.g. bootp.
2116 (Environment variable "ipaddr")
2118 - Server IP address:
2121 Defines a default value for the IP address of a TFTP
2122 server to contact when using the "tftboot" command.
2123 (Environment variable "serverip")
2125 CONFIG_KEEP_SERVERADDR
2127 Keeps the server's MAC address, in the env 'serveraddr'
2128 for passing to bootargs (like Linux's netconsole option)
2130 - Gateway IP address:
2133 Defines a default value for the IP address of the
2134 default router where packets to other networks are
2136 (Environment variable "gatewayip")
2141 Defines a default value for the subnet mask (or
2142 routing prefix) which is used to determine if an IP
2143 address belongs to the local subnet or needs to be
2144 forwarded through a router.
2145 (Environment variable "netmask")
2147 - Multicast TFTP Mode:
2150 Defines whether you want to support multicast TFTP as per
2151 rfc-2090; for example to work with atftp. Lets lots of targets
2152 tftp down the same boot image concurrently. Note: the Ethernet
2153 driver in use must provide a function: mcast() to join/leave a
2156 - BOOTP Recovery Mode:
2157 CONFIG_BOOTP_RANDOM_DELAY
2159 If you have many targets in a network that try to
2160 boot using BOOTP, you may want to avoid that all
2161 systems send out BOOTP requests at precisely the same
2162 moment (which would happen for instance at recovery
2163 from a power failure, when all systems will try to
2164 boot, thus flooding the BOOTP server. Defining
2165 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
2166 inserted before sending out BOOTP requests. The
2167 following delays are inserted then:
2169 1st BOOTP request: delay 0 ... 1 sec
2170 2nd BOOTP request: delay 0 ... 2 sec
2171 3rd BOOTP request: delay 0 ... 4 sec
2173 BOOTP requests: delay 0 ... 8 sec
2175 CONFIG_BOOTP_ID_CACHE_SIZE
2177 BOOTP packets are uniquely identified using a 32-bit ID. The
2178 server will copy the ID from client requests to responses and
2179 U-Boot will use this to determine if it is the destination of
2180 an incoming response. Some servers will check that addresses
2181 aren't in use before handing them out (usually using an ARP
2182 ping) and therefore take up to a few hundred milliseconds to
2183 respond. Network congestion may also influence the time it
2184 takes for a response to make it back to the client. If that
2185 time is too long, U-Boot will retransmit requests. In order
2186 to allow earlier responses to still be accepted after these
2187 retransmissions, U-Boot's BOOTP client keeps a small cache of
2188 IDs. The CONFIG_BOOTP_ID_CACHE_SIZE controls the size of this
2189 cache. The default is to keep IDs for up to four outstanding
2190 requests. Increasing this will allow U-Boot to accept offers
2191 from a BOOTP client in networks with unusually high latency.
2193 - DHCP Advanced Options:
2194 You can fine tune the DHCP functionality by defining
2195 CONFIG_BOOTP_* symbols:
2197 CONFIG_BOOTP_SUBNETMASK
2198 CONFIG_BOOTP_GATEWAY
2199 CONFIG_BOOTP_HOSTNAME
2200 CONFIG_BOOTP_NISDOMAIN
2201 CONFIG_BOOTP_BOOTPATH
2202 CONFIG_BOOTP_BOOTFILESIZE
2205 CONFIG_BOOTP_SEND_HOSTNAME
2206 CONFIG_BOOTP_NTPSERVER
2207 CONFIG_BOOTP_TIMEOFFSET
2208 CONFIG_BOOTP_VENDOREX
2209 CONFIG_BOOTP_MAY_FAIL
2211 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip
2212 environment variable, not the BOOTP server.
2214 CONFIG_BOOTP_MAY_FAIL - If the DHCP server is not found
2215 after the configured retry count, the call will fail
2216 instead of starting over. This can be used to fail over
2217 to Link-local IP address configuration if the DHCP server
2220 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS
2221 serverip from a DHCP server, it is possible that more
2222 than one DNS serverip is offered to the client.
2223 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS
2224 serverip will be stored in the additional environment
2225 variable "dnsip2". The first DNS serverip is always
2226 stored in the variable "dnsip", when CONFIG_BOOTP_DNS
2229 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable
2230 to do a dynamic update of a DNS server. To do this, they
2231 need the hostname of the DHCP requester.
2232 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content
2233 of the "hostname" environment variable is passed as
2234 option 12 to the DHCP server.
2236 CONFIG_BOOTP_DHCP_REQUEST_DELAY
2238 A 32bit value in microseconds for a delay between
2239 receiving a "DHCP Offer" and sending the "DHCP Request".
2240 This fixes a problem with certain DHCP servers that don't
2241 respond 100% of the time to a "DHCP request". E.g. On an
2242 AT91RM9200 processor running at 180MHz, this delay needed
2243 to be *at least* 15,000 usec before a Windows Server 2003
2244 DHCP server would reply 100% of the time. I recommend at
2245 least 50,000 usec to be safe. The alternative is to hope
2246 that one of the retries will be successful but note that
2247 the DHCP timeout and retry process takes a longer than
2250 - Link-local IP address negotiation:
2251 Negotiate with other link-local clients on the local network
2252 for an address that doesn't require explicit configuration.
2253 This is especially useful if a DHCP server cannot be guaranteed
2254 to exist in all environments that the device must operate.
2256 See doc/README.link-local for more information.
2259 CONFIG_CDP_DEVICE_ID
2261 The device id used in CDP trigger frames.
2263 CONFIG_CDP_DEVICE_ID_PREFIX
2265 A two character string which is prefixed to the MAC address
2270 A printf format string which contains the ascii name of
2271 the port. Normally is set to "eth%d" which sets
2272 eth0 for the first Ethernet, eth1 for the second etc.
2274 CONFIG_CDP_CAPABILITIES
2276 A 32bit integer which indicates the device capabilities;
2277 0x00000010 for a normal host which does not forwards.
2281 An ascii string containing the version of the software.
2285 An ascii string containing the name of the platform.
2289 A 32bit integer sent on the trigger.
2291 CONFIG_CDP_POWER_CONSUMPTION
2293 A 16bit integer containing the power consumption of the
2294 device in .1 of milliwatts.
2296 CONFIG_CDP_APPLIANCE_VLAN_TYPE
2298 A byte containing the id of the VLAN.
2300 - Status LED: CONFIG_STATUS_LED
2302 Several configurations allow to display the current
2303 status using a LED. For instance, the LED will blink
2304 fast while running U-Boot code, stop blinking as
2305 soon as a reply to a BOOTP request was received, and
2306 start blinking slow once the Linux kernel is running
2307 (supported by a status LED driver in the Linux
2308 kernel). Defining CONFIG_STATUS_LED enables this
2314 The status LED can be connected to a GPIO pin.
2315 In such cases, the gpio_led driver can be used as a
2316 status LED backend implementation. Define CONFIG_GPIO_LED
2317 to include the gpio_led driver in the U-Boot binary.
2319 CONFIG_GPIO_LED_INVERTED_TABLE
2320 Some GPIO connected LEDs may have inverted polarity in which
2321 case the GPIO high value corresponds to LED off state and
2322 GPIO low value corresponds to LED on state.
2323 In such cases CONFIG_GPIO_LED_INVERTED_TABLE may be defined
2324 with a list of GPIO LEDs that have inverted polarity.
2326 - CAN Support: CONFIG_CAN_DRIVER
2328 Defining CONFIG_CAN_DRIVER enables CAN driver support
2329 on those systems that support this (optional)
2330 feature, like the TQM8xxL modules.
2332 - I2C Support: CONFIG_SYS_I2C
2334 This enable the NEW i2c subsystem, and will allow you to use
2335 i2c commands at the u-boot command line (as long as you set
2336 CONFIG_CMD_I2C in CONFIG_COMMANDS) and communicate with i2c
2337 based realtime clock chips or other i2c devices. See
2338 common/cmd_i2c.c for a description of the command line
2341 ported i2c driver to the new framework:
2342 - drivers/i2c/soft_i2c.c:
2343 - activate first bus with CONFIG_SYS_I2C_SOFT define
2344 CONFIG_SYS_I2C_SOFT_SPEED and CONFIG_SYS_I2C_SOFT_SLAVE
2345 for defining speed and slave address
2346 - activate second bus with I2C_SOFT_DECLARATIONS2 define
2347 CONFIG_SYS_I2C_SOFT_SPEED_2 and CONFIG_SYS_I2C_SOFT_SLAVE_2
2348 for defining speed and slave address
2349 - activate third bus with I2C_SOFT_DECLARATIONS3 define
2350 CONFIG_SYS_I2C_SOFT_SPEED_3 and CONFIG_SYS_I2C_SOFT_SLAVE_3
2351 for defining speed and slave address
2352 - activate fourth bus with I2C_SOFT_DECLARATIONS4 define
2353 CONFIG_SYS_I2C_SOFT_SPEED_4 and CONFIG_SYS_I2C_SOFT_SLAVE_4
2354 for defining speed and slave address
2356 - drivers/i2c/fsl_i2c.c:
2357 - activate i2c driver with CONFIG_SYS_I2C_FSL
2358 define CONFIG_SYS_FSL_I2C_OFFSET for setting the register
2359 offset CONFIG_SYS_FSL_I2C_SPEED for the i2c speed and
2360 CONFIG_SYS_FSL_I2C_SLAVE for the slave addr of the first
2362 - If your board supports a second fsl i2c bus, define
2363 CONFIG_SYS_FSL_I2C2_OFFSET for the register offset
2364 CONFIG_SYS_FSL_I2C2_SPEED for the speed and
2365 CONFIG_SYS_FSL_I2C2_SLAVE for the slave address of the
2368 - drivers/i2c/tegra_i2c.c:
2369 - activate this driver with CONFIG_SYS_I2C_TEGRA
2370 - This driver adds 4 i2c buses with a fix speed from
2371 100000 and the slave addr 0!
2373 - drivers/i2c/ppc4xx_i2c.c
2374 - activate this driver with CONFIG_SYS_I2C_PPC4XX
2375 - CONFIG_SYS_I2C_PPC4XX_CH0 activate hardware channel 0
2376 - CONFIG_SYS_I2C_PPC4XX_CH1 activate hardware channel 1
2378 - drivers/i2c/i2c_mxc.c
2379 - activate this driver with CONFIG_SYS_I2C_MXC
2380 - define speed for bus 1 with CONFIG_SYS_MXC_I2C1_SPEED
2381 - define slave for bus 1 with CONFIG_SYS_MXC_I2C1_SLAVE
2382 - define speed for bus 2 with CONFIG_SYS_MXC_I2C2_SPEED
2383 - define slave for bus 2 with CONFIG_SYS_MXC_I2C2_SLAVE
2384 - define speed for bus 3 with CONFIG_SYS_MXC_I2C3_SPEED
2385 - define slave for bus 3 with CONFIG_SYS_MXC_I2C3_SLAVE
2386 If those defines are not set, default value is 100000
2387 for speed, and 0 for slave.
2388 - enable bus 3 with CONFIG_SYS_I2C_MXC_I2C3
2389 - enable bus 4 with CONFIG_SYS_I2C_MXC_I2C4
2391 - drivers/i2c/rcar_i2c.c:
2392 - activate this driver with CONFIG_SYS_I2C_RCAR
2393 - This driver adds 4 i2c buses
2395 - CONFIG_SYS_RCAR_I2C0_BASE for setting the register channel 0
2396 - CONFIG_SYS_RCAR_I2C0_SPEED for for the speed channel 0
2397 - CONFIG_SYS_RCAR_I2C1_BASE for setting the register channel 1
2398 - CONFIG_SYS_RCAR_I2C1_SPEED for for the speed channel 1
2399 - CONFIG_SYS_RCAR_I2C2_BASE for setting the register channel 2
2400 - CONFIG_SYS_RCAR_I2C2_SPEED for for the speed channel 2
2401 - CONFIG_SYS_RCAR_I2C3_BASE for setting the register channel 3
2402 - CONFIG_SYS_RCAR_I2C3_SPEED for for the speed channel 3
2403 - CONFIF_SYS_RCAR_I2C_NUM_CONTROLLERS for number of i2c buses
2405 - drivers/i2c/sh_i2c.c:
2406 - activate this driver with CONFIG_SYS_I2C_SH
2407 - This driver adds from 2 to 5 i2c buses
2409 - CONFIG_SYS_I2C_SH_BASE0 for setting the register channel 0
2410 - CONFIG_SYS_I2C_SH_SPEED0 for for the speed channel 0
2411 - CONFIG_SYS_I2C_SH_BASE1 for setting the register channel 1
2412 - CONFIG_SYS_I2C_SH_SPEED1 for for the speed channel 1
2413 - CONFIG_SYS_I2C_SH_BASE2 for setting the register channel 2
2414 - CONFIG_SYS_I2C_SH_SPEED2 for for the speed channel 2
2415 - CONFIG_SYS_I2C_SH_BASE3 for setting the register channel 3
2416 - CONFIG_SYS_I2C_SH_SPEED3 for for the speed channel 3
2417 - CONFIG_SYS_I2C_SH_BASE4 for setting the register channel 4
2418 - CONFIG_SYS_I2C_SH_SPEED4 for for the speed channel 4
2419 - CONFIG_SYS_I2C_SH_BASE5 for setting the register channel 5
2420 - CONFIG_SYS_I2C_SH_SPEED5 for for the speed channel 5
2421 - CONFIG_SYS_I2C_SH_NUM_CONTROLLERS for number of i2c buses
2423 - drivers/i2c/omap24xx_i2c.c
2424 - activate this driver with CONFIG_SYS_I2C_OMAP24XX
2425 - CONFIG_SYS_OMAP24_I2C_SPEED speed channel 0
2426 - CONFIG_SYS_OMAP24_I2C_SLAVE slave addr channel 0
2427 - CONFIG_SYS_OMAP24_I2C_SPEED1 speed channel 1
2428 - CONFIG_SYS_OMAP24_I2C_SLAVE1 slave addr channel 1
2429 - CONFIG_SYS_OMAP24_I2C_SPEED2 speed channel 2
2430 - CONFIG_SYS_OMAP24_I2C_SLAVE2 slave addr channel 2
2431 - CONFIG_SYS_OMAP24_I2C_SPEED3 speed channel 3
2432 - CONFIG_SYS_OMAP24_I2C_SLAVE3 slave addr channel 3
2433 - CONFIG_SYS_OMAP24_I2C_SPEED4 speed channel 4
2434 - CONFIG_SYS_OMAP24_I2C_SLAVE4 slave addr channel 4
2436 - drivers/i2c/zynq_i2c.c
2437 - activate this driver with CONFIG_SYS_I2C_ZYNQ
2438 - set CONFIG_SYS_I2C_ZYNQ_SPEED for speed setting
2439 - set CONFIG_SYS_I2C_ZYNQ_SLAVE for slave addr
2441 - drivers/i2c/s3c24x0_i2c.c:
2442 - activate this driver with CONFIG_SYS_I2C_S3C24X0
2443 - This driver adds i2c buses (11 for Exynos5250, Exynos5420
2444 9 i2c buses for Exynos4 and 1 for S3C24X0 SoCs from Samsung)
2445 with a fix speed from 100000 and the slave addr 0!
2447 - drivers/i2c/ihs_i2c.c
2448 - activate this driver with CONFIG_SYS_I2C_IHS
2449 - CONFIG_SYS_I2C_IHS_CH0 activate hardware channel 0
2450 - CONFIG_SYS_I2C_IHS_SPEED_0 speed channel 0
2451 - CONFIG_SYS_I2C_IHS_SLAVE_0 slave addr channel 0
2452 - CONFIG_SYS_I2C_IHS_CH1 activate hardware channel 1
2453 - CONFIG_SYS_I2C_IHS_SPEED_1 speed channel 1
2454 - CONFIG_SYS_I2C_IHS_SLAVE_1 slave addr channel 1
2455 - CONFIG_SYS_I2C_IHS_CH2 activate hardware channel 2
2456 - CONFIG_SYS_I2C_IHS_SPEED_2 speed channel 2
2457 - CONFIG_SYS_I2C_IHS_SLAVE_2 slave addr channel 2
2458 - CONFIG_SYS_I2C_IHS_CH3 activate hardware channel 3
2459 - CONFIG_SYS_I2C_IHS_SPEED_3 speed channel 3
2460 - CONFIG_SYS_I2C_IHS_SLAVE_3 slave addr channel 3
2464 CONFIG_SYS_NUM_I2C_BUSES
2465 Hold the number of i2c buses you want to use. If you
2466 don't use/have i2c muxes on your i2c bus, this
2467 is equal to CONFIG_SYS_NUM_I2C_ADAPTERS, and you can
2470 CONFIG_SYS_I2C_DIRECT_BUS
2471 define this, if you don't use i2c muxes on your hardware.
2472 if CONFIG_SYS_I2C_MAX_HOPS is not defined or == 0 you can
2475 CONFIG_SYS_I2C_MAX_HOPS
2476 define how many muxes are maximal consecutively connected
2477 on one i2c bus. If you not use i2c muxes, omit this
2480 CONFIG_SYS_I2C_BUSES
2481 hold a list of buses you want to use, only used if
2482 CONFIG_SYS_I2C_DIRECT_BUS is not defined, for example
2483 a board with CONFIG_SYS_I2C_MAX_HOPS = 1 and
2484 CONFIG_SYS_NUM_I2C_BUSES = 9:
2486 CONFIG_SYS_I2C_BUSES {{0, {I2C_NULL_HOP}}, \
2487 {0, {{I2C_MUX_PCA9547, 0x70, 1}}}, \
2488 {0, {{I2C_MUX_PCA9547, 0x70, 2}}}, \
2489 {0, {{I2C_MUX_PCA9547, 0x70, 3}}}, \
2490 {0, {{I2C_MUX_PCA9547, 0x70, 4}}}, \
2491 {0, {{I2C_MUX_PCA9547, 0x70, 5}}}, \
2492 {1, {I2C_NULL_HOP}}, \
2493 {1, {{I2C_MUX_PCA9544, 0x72, 1}}}, \
2494 {1, {{I2C_MUX_PCA9544, 0x72, 2}}}, \
2498 bus 0 on adapter 0 without a mux
2499 bus 1 on adapter 0 with a PCA9547 on address 0x70 port 1
2500 bus 2 on adapter 0 with a PCA9547 on address 0x70 port 2
2501 bus 3 on adapter 0 with a PCA9547 on address 0x70 port 3
2502 bus 4 on adapter 0 with a PCA9547 on address 0x70 port 4
2503 bus 5 on adapter 0 with a PCA9547 on address 0x70 port 5
2504 bus 6 on adapter 1 without a mux
2505 bus 7 on adapter 1 with a PCA9544 on address 0x72 port 1
2506 bus 8 on adapter 1 with a PCA9544 on address 0x72 port 2
2508 If you do not have i2c muxes on your board, omit this define.
2510 - Legacy I2C Support: CONFIG_HARD_I2C
2512 NOTE: It is intended to move drivers to CONFIG_SYS_I2C which
2513 provides the following compelling advantages:
2515 - more than one i2c adapter is usable
2516 - approved multibus support
2517 - better i2c mux support
2519 ** Please consider updating your I2C driver now. **
2521 These enable legacy I2C serial bus commands. Defining
2522 CONFIG_HARD_I2C will include the appropriate I2C driver
2523 for the selected CPU.
2525 This will allow you to use i2c commands at the u-boot
2526 command line (as long as you set CONFIG_CMD_I2C in
2527 CONFIG_COMMANDS) and communicate with i2c based realtime
2528 clock chips. See common/cmd_i2c.c for a description of the
2529 command line interface.
2531 CONFIG_HARD_I2C selects a hardware I2C controller.
2533 There are several other quantities that must also be
2534 defined when you define CONFIG_HARD_I2C.
2536 In both cases you will need to define CONFIG_SYS_I2C_SPEED
2537 to be the frequency (in Hz) at which you wish your i2c bus
2538 to run and CONFIG_SYS_I2C_SLAVE to be the address of this node (ie
2539 the CPU's i2c node address).
2541 Now, the u-boot i2c code for the mpc8xx
2542 (arch/powerpc/cpu/mpc8xx/i2c.c) sets the CPU up as a master node
2543 and so its address should therefore be cleared to 0 (See,
2544 eg, MPC823e User's Manual p.16-473). So, set
2545 CONFIG_SYS_I2C_SLAVE to 0.
2547 CONFIG_SYS_I2C_INIT_MPC5XXX
2549 When a board is reset during an i2c bus transfer
2550 chips might think that the current transfer is still
2551 in progress. Reset the slave devices by sending start
2552 commands until the slave device responds.
2554 That's all that's required for CONFIG_HARD_I2C.
2556 If you use the software i2c interface (CONFIG_SYS_I2C_SOFT)
2557 then the following macros need to be defined (examples are
2558 from include/configs/lwmon.h):
2562 (Optional). Any commands necessary to enable the I2C
2563 controller or configure ports.
2565 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
2569 (Only for MPC8260 CPU). The I/O port to use (the code
2570 assumes both bits are on the same port). Valid values
2571 are 0..3 for ports A..D.
2575 The code necessary to make the I2C data line active
2576 (driven). If the data line is open collector, this
2579 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
2583 The code necessary to make the I2C data line tri-stated
2584 (inactive). If the data line is open collector, this
2587 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
2591 Code that returns true if the I2C data line is high,
2594 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
2598 If <bit> is true, sets the I2C data line high. If it
2599 is false, it clears it (low).
2601 eg: #define I2C_SDA(bit) \
2602 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
2603 else immr->im_cpm.cp_pbdat &= ~PB_SDA
2607 If <bit> is true, sets the I2C clock line high. If it
2608 is false, it clears it (low).
2610 eg: #define I2C_SCL(bit) \
2611 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
2612 else immr->im_cpm.cp_pbdat &= ~PB_SCL
2616 This delay is invoked four times per clock cycle so this
2617 controls the rate of data transfer. The data rate thus
2618 is 1 / (I2C_DELAY * 4). Often defined to be something
2621 #define I2C_DELAY udelay(2)
2623 CONFIG_SOFT_I2C_GPIO_SCL / CONFIG_SOFT_I2C_GPIO_SDA
2625 If your arch supports the generic GPIO framework (asm/gpio.h),
2626 then you may alternatively define the two GPIOs that are to be
2627 used as SCL / SDA. Any of the previous I2C_xxx macros will
2628 have GPIO-based defaults assigned to them as appropriate.
2630 You should define these to the GPIO value as given directly to
2631 the generic GPIO functions.
2633 CONFIG_SYS_I2C_INIT_BOARD
2635 When a board is reset during an i2c bus transfer
2636 chips might think that the current transfer is still
2637 in progress. On some boards it is possible to access
2638 the i2c SCLK line directly, either by using the
2639 processor pin as a GPIO or by having a second pin
2640 connected to the bus. If this option is defined a
2641 custom i2c_init_board() routine in boards/xxx/board.c
2642 is run early in the boot sequence.
2644 CONFIG_SYS_I2C_BOARD_LATE_INIT
2646 An alternative to CONFIG_SYS_I2C_INIT_BOARD. If this option is
2647 defined a custom i2c_board_late_init() routine in
2648 boards/xxx/board.c is run AFTER the operations in i2c_init()
2649 is completed. This callpoint can be used to unreset i2c bus
2650 using CPU i2c controller register accesses for CPUs whose i2c
2651 controller provide such a method. It is called at the end of
2652 i2c_init() to allow i2c_init operations to setup the i2c bus
2653 controller on the CPU (e.g. setting bus speed & slave address).
2655 CONFIG_I2CFAST (PPC405GP|PPC405EP only)
2657 This option enables configuration of bi_iic_fast[] flags
2658 in u-boot bd_info structure based on u-boot environment
2659 variable "i2cfast". (see also i2cfast)
2661 CONFIG_I2C_MULTI_BUS
2663 This option allows the use of multiple I2C buses, each of which
2664 must have a controller. At any point in time, only one bus is
2665 active. To switch to a different bus, use the 'i2c dev' command.
2666 Note that bus numbering is zero-based.
2668 CONFIG_SYS_I2C_NOPROBES
2670 This option specifies a list of I2C devices that will be skipped
2671 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS
2672 is set, specify a list of bus-device pairs. Otherwise, specify
2673 a 1D array of device addresses
2676 #undef CONFIG_I2C_MULTI_BUS
2677 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68}
2679 will skip addresses 0x50 and 0x68 on a board with one I2C bus
2681 #define CONFIG_I2C_MULTI_BUS
2682 #define CONFIG_SYS_I2C_MULTI_NOPROBES {{0,0x50},{0,0x68},{1,0x54}}
2684 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1
2686 CONFIG_SYS_SPD_BUS_NUM
2688 If defined, then this indicates the I2C bus number for DDR SPD.
2689 If not defined, then U-Boot assumes that SPD is on I2C bus 0.
2691 CONFIG_SYS_RTC_BUS_NUM
2693 If defined, then this indicates the I2C bus number for the RTC.
2694 If not defined, then U-Boot assumes that RTC is on I2C bus 0.
2696 CONFIG_SYS_DTT_BUS_NUM
2698 If defined, then this indicates the I2C bus number for the DTT.
2699 If not defined, then U-Boot assumes that DTT is on I2C bus 0.
2701 CONFIG_SYS_I2C_DTT_ADDR:
2703 If defined, specifies the I2C address of the DTT device.
2704 If not defined, then U-Boot uses predefined value for
2705 specified DTT device.
2707 CONFIG_SOFT_I2C_READ_REPEATED_START
2709 defining this will force the i2c_read() function in
2710 the soft_i2c driver to perform an I2C repeated start
2711 between writing the address pointer and reading the
2712 data. If this define is omitted the default behaviour
2713 of doing a stop-start sequence will be used. Most I2C
2714 devices can use either method, but some require one or
2717 - SPI Support: CONFIG_SPI
2719 Enables SPI driver (so far only tested with
2720 SPI EEPROM, also an instance works with Crystal A/D and
2721 D/As on the SACSng board)
2725 Enables the driver for SPI controller on SuperH. Currently
2726 only SH7757 is supported.
2730 Enables extended (16-bit) SPI EEPROM addressing.
2731 (symmetrical to CONFIG_I2C_X)
2735 Enables a software (bit-bang) SPI driver rather than
2736 using hardware support. This is a general purpose
2737 driver that only requires three general I/O port pins
2738 (two outputs, one input) to function. If this is
2739 defined, the board configuration must define several
2740 SPI configuration items (port pins to use, etc). For
2741 an example, see include/configs/sacsng.h.
2745 Enables a hardware SPI driver for general-purpose reads
2746 and writes. As with CONFIG_SOFT_SPI, the board configuration
2747 must define a list of chip-select function pointers.
2748 Currently supported on some MPC8xxx processors. For an
2749 example, see include/configs/mpc8349emds.h.
2753 Enables the driver for the SPI controllers on i.MX and MXC
2754 SoCs. Currently i.MX31/35/51 are supported.
2756 CONFIG_SYS_SPI_MXC_WAIT
2757 Timeout for waiting until spi transfer completed.
2758 default: (CONFIG_SYS_HZ/100) /* 10 ms */
2760 - FPGA Support: CONFIG_FPGA
2762 Enables FPGA subsystem.
2764 CONFIG_FPGA_<vendor>
2766 Enables support for specific chip vendors.
2769 CONFIG_FPGA_<family>
2771 Enables support for FPGA family.
2772 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX)
2776 Specify the number of FPGA devices to support.
2778 CONFIG_CMD_FPGA_LOADMK
2780 Enable support for fpga loadmk command
2782 CONFIG_CMD_FPGA_LOADP
2784 Enable support for fpga loadp command - load partial bitstream
2786 CONFIG_CMD_FPGA_LOADBP
2788 Enable support for fpga loadbp command - load partial bitstream
2791 CONFIG_SYS_FPGA_PROG_FEEDBACK
2793 Enable printing of hash marks during FPGA configuration.
2795 CONFIG_SYS_FPGA_CHECK_BUSY
2797 Enable checks on FPGA configuration interface busy
2798 status by the configuration function. This option
2799 will require a board or device specific function to
2804 If defined, a function that provides delays in the FPGA
2805 configuration driver.
2807 CONFIG_SYS_FPGA_CHECK_CTRLC
2808 Allow Control-C to interrupt FPGA configuration
2810 CONFIG_SYS_FPGA_CHECK_ERROR
2812 Check for configuration errors during FPGA bitfile
2813 loading. For example, abort during Virtex II
2814 configuration if the INIT_B line goes low (which
2815 indicated a CRC error).
2817 CONFIG_SYS_FPGA_WAIT_INIT
2819 Maximum time to wait for the INIT_B line to de-assert
2820 after PROB_B has been de-asserted during a Virtex II
2821 FPGA configuration sequence. The default time is 500
2824 CONFIG_SYS_FPGA_WAIT_BUSY
2826 Maximum time to wait for BUSY to de-assert during
2827 Virtex II FPGA configuration. The default is 5 ms.
2829 CONFIG_SYS_FPGA_WAIT_CONFIG
2831 Time to wait after FPGA configuration. The default is
2834 - Configuration Management:
2837 Some SoCs need special image types (e.g. U-Boot binary
2838 with a special header) as build targets. By defining
2839 CONFIG_BUILD_TARGET in the SoC / board header, this
2840 special image will be automatically built upon calling
2845 If defined, this string will be added to the U-Boot
2846 version information (U_BOOT_VERSION)
2848 - Vendor Parameter Protection:
2850 U-Boot considers the values of the environment
2851 variables "serial#" (Board Serial Number) and
2852 "ethaddr" (Ethernet Address) to be parameters that
2853 are set once by the board vendor / manufacturer, and
2854 protects these variables from casual modification by
2855 the user. Once set, these variables are read-only,
2856 and write or delete attempts are rejected. You can
2857 change this behaviour:
2859 If CONFIG_ENV_OVERWRITE is #defined in your config
2860 file, the write protection for vendor parameters is
2861 completely disabled. Anybody can change or delete
2864 Alternatively, if you define _both_ an ethaddr in the
2865 default env _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
2866 Ethernet address is installed in the environment,
2867 which can be changed exactly ONCE by the user. [The
2868 serial# is unaffected by this, i. e. it remains
2871 The same can be accomplished in a more flexible way
2872 for any variable by configuring the type of access
2873 to allow for those variables in the ".flags" variable
2874 or define CONFIG_ENV_FLAGS_LIST_STATIC.
2879 Define this variable to enable the reservation of
2880 "protected RAM", i. e. RAM which is not overwritten
2881 by U-Boot. Define CONFIG_PRAM to hold the number of
2882 kB you want to reserve for pRAM. You can overwrite
2883 this default value by defining an environment
2884 variable "pram" to the number of kB you want to
2885 reserve. Note that the board info structure will
2886 still show the full amount of RAM. If pRAM is
2887 reserved, a new environment variable "mem" will
2888 automatically be defined to hold the amount of
2889 remaining RAM in a form that can be passed as boot
2890 argument to Linux, for instance like that:
2892 setenv bootargs ... mem=\${mem}
2895 This way you can tell Linux not to use this memory,
2896 either, which results in a memory region that will
2897 not be affected by reboots.
2899 *WARNING* If your board configuration uses automatic
2900 detection of the RAM size, you must make sure that
2901 this memory test is non-destructive. So far, the
2902 following board configurations are known to be
2905 IVMS8, IVML24, SPD8xx, TQM8xxL,
2906 HERMES, IP860, RPXlite, LWMON,
2909 - Access to physical memory region (> 4GB)
2910 Some basic support is provided for operations on memory not
2911 normally accessible to U-Boot - e.g. some architectures
2912 support access to more than 4GB of memory on 32-bit
2913 machines using physical address extension or similar.
2914 Define CONFIG_PHYSMEM to access this basic support, which
2915 currently only supports clearing the memory.
2920 Define this variable to stop the system in case of a
2921 fatal error, so that you have to reset it manually.
2922 This is probably NOT a good idea for an embedded
2923 system where you want the system to reboot
2924 automatically as fast as possible, but it may be
2925 useful during development since you can try to debug
2926 the conditions that lead to the situation.
2928 CONFIG_NET_RETRY_COUNT
2930 This variable defines the number of retries for
2931 network operations like ARP, RARP, TFTP, or BOOTP
2932 before giving up the operation. If not defined, a
2933 default value of 5 is used.
2937 Timeout waiting for an ARP reply in milliseconds.
2941 Timeout in milliseconds used in NFS protocol.
2942 If you encounter "ERROR: Cannot umount" in nfs command,
2943 try longer timeout such as
2944 #define CONFIG_NFS_TIMEOUT 10000UL
2946 - Command Interpreter:
2947 CONFIG_AUTO_COMPLETE
2949 Enable auto completion of commands using TAB.
2951 CONFIG_SYS_PROMPT_HUSH_PS2
2953 This defines the secondary prompt string, which is
2954 printed when the command interpreter needs more input
2955 to complete a command. Usually "> ".
2959 In the current implementation, the local variables
2960 space and global environment variables space are
2961 separated. Local variables are those you define by
2962 simply typing `name=value'. To access a local
2963 variable later on, you have write `$name' or
2964 `${name}'; to execute the contents of a variable
2965 directly type `$name' at the command prompt.
2967 Global environment variables are those you use
2968 setenv/printenv to work with. To run a command stored
2969 in such a variable, you need to use the run command,
2970 and you must not use the '$' sign to access them.
2972 To store commands and special characters in a
2973 variable, please use double quotation marks
2974 surrounding the whole text of the variable, instead
2975 of the backslashes before semicolons and special
2978 - Command Line Editing and History:
2979 CONFIG_CMDLINE_EDITING
2981 Enable editing and History functions for interactive
2982 command line input operations
2984 - Default Environment:
2985 CONFIG_EXTRA_ENV_SETTINGS
2987 Define this to contain any number of null terminated
2988 strings (variable = value pairs) that will be part of
2989 the default environment compiled into the boot image.
2991 For example, place something like this in your
2992 board's config file:
2994 #define CONFIG_EXTRA_ENV_SETTINGS \
2998 Warning: This method is based on knowledge about the
2999 internal format how the environment is stored by the
3000 U-Boot code. This is NOT an official, exported
3001 interface! Although it is unlikely that this format
3002 will change soon, there is no guarantee either.
3003 You better know what you are doing here.
3005 Note: overly (ab)use of the default environment is
3006 discouraged. Make sure to check other ways to preset
3007 the environment like the "source" command or the
3010 CONFIG_ENV_VARS_UBOOT_CONFIG
3012 Define this in order to add variables describing the
3013 U-Boot build configuration to the default environment.
3014 These will be named arch, cpu, board, vendor, and soc.
3016 Enabling this option will cause the following to be defined:
3024 CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG
3026 Define this in order to add variables describing certain
3027 run-time determined information about the hardware to the
3028 environment. These will be named board_name, board_rev.
3030 CONFIG_DELAY_ENVIRONMENT
3032 Normally the environment is loaded when the board is
3033 initialised so that it is available to U-Boot. This inhibits
3034 that so that the environment is not available until
3035 explicitly loaded later by U-Boot code. With CONFIG_OF_CONTROL
3036 this is instead controlled by the value of
3037 /config/load-environment.
3039 - Parallel Flash support:
3042 Traditionally U-boot was run on systems with parallel NOR
3043 flash. This option is used to disable support for parallel NOR
3044 flash. This option should be defined if the board does not have
3047 If this option is not defined one of the generic flash drivers
3048 (e.g. CONFIG_FLASH_CFI_DRIVER or CONFIG_ST_SMI) must be
3049 selected or the board must provide an implementation of the
3050 flash API (see include/flash.h).
3052 - DataFlash Support:
3053 CONFIG_HAS_DATAFLASH
3055 Defining this option enables DataFlash features and
3056 allows to read/write in Dataflash via the standard
3059 - Serial Flash support
3062 Defining this option enables SPI flash commands
3063 'sf probe/read/write/erase/update'.
3065 Usage requires an initial 'probe' to define the serial
3066 flash parameters, followed by read/write/erase/update
3069 The following defaults may be provided by the platform
3070 to handle the common case when only a single serial
3071 flash is present on the system.
3073 CONFIG_SF_DEFAULT_BUS Bus identifier
3074 CONFIG_SF_DEFAULT_CS Chip-select
3075 CONFIG_SF_DEFAULT_MODE (see include/spi.h)
3076 CONFIG_SF_DEFAULT_SPEED in Hz
3080 Define this option to include a destructive SPI flash
3083 CONFIG_SF_DUAL_FLASH Dual flash memories
3085 Define this option to use dual flash support where two flash
3086 memories can be connected with a given cs line.
3087 Currently Xilinx Zynq qspi supports these type of connections.
3089 - SystemACE Support:
3092 Adding this option adds support for Xilinx SystemACE
3093 chips attached via some sort of local bus. The address
3094 of the chip must also be defined in the
3095 CONFIG_SYS_SYSTEMACE_BASE macro. For example:
3097 #define CONFIG_SYSTEMACE
3098 #define CONFIG_SYS_SYSTEMACE_BASE 0xf0000000
3100 When SystemACE support is added, the "ace" device type
3101 becomes available to the fat commands, i.e. fatls.
3103 - TFTP Fixed UDP Port:
3106 If this is defined, the environment variable tftpsrcp
3107 is used to supply the TFTP UDP source port value.
3108 If tftpsrcp isn't defined, the normal pseudo-random port
3109 number generator is used.
3111 Also, the environment variable tftpdstp is used to supply
3112 the TFTP UDP destination port value. If tftpdstp isn't
3113 defined, the normal port 69 is used.
3115 The purpose for tftpsrcp is to allow a TFTP server to
3116 blindly start the TFTP transfer using the pre-configured
3117 target IP address and UDP port. This has the effect of
3118 "punching through" the (Windows XP) firewall, allowing
3119 the remainder of the TFTP transfer to proceed normally.
3120 A better solution is to properly configure the firewall,
3121 but sometimes that is not allowed.
3126 This enables a generic 'hash' command which can produce
3127 hashes / digests from a few algorithms (e.g. SHA1, SHA256).
3131 Enable the hash verify command (hash -v). This adds to code
3134 CONFIG_SHA1 - This option enables support of hashing using SHA1
3135 algorithm. The hash is calculated in software.
3136 CONFIG_SHA256 - This option enables support of hashing using
3137 SHA256 algorithm. The hash is calculated in software.
3138 CONFIG_SHA_HW_ACCEL - This option enables hardware acceleration
3139 for SHA1/SHA256 hashing.
3140 This affects the 'hash' command and also the
3141 hash_lookup_algo() function.
3142 CONFIG_SHA_PROG_HW_ACCEL - This option enables
3143 hardware-acceleration for SHA1/SHA256 progressive hashing.
3144 Data can be streamed in a block at a time and the hashing
3145 is performed in hardware.
3147 Note: There is also a sha1sum command, which should perhaps
3148 be deprecated in favour of 'hash sha1'.
3150 - Freescale i.MX specific commands:
3151 CONFIG_CMD_HDMIDETECT
3152 This enables 'hdmidet' command which returns true if an
3153 HDMI monitor is detected. This command is i.MX 6 specific.
3156 This enables the 'bmode' (bootmode) command for forcing
3157 a boot from specific media.
3159 This is useful for forcing the ROM's usb downloader to
3160 activate upon a watchdog reset which is nice when iterating
3161 on U-Boot. Using the reset button or running bmode normal
3162 will set it back to normal. This command currently
3163 supports i.MX53 and i.MX6.
3168 This enables the RSA algorithm used for FIT image verification
3169 in U-Boot. See doc/uImage.FIT/signature.txt for more information.
3171 The Modular Exponentiation algorithm in RSA is implemented using
3172 driver model. So CONFIG_DM needs to be enabled by default for this
3173 library to function.
3175 The signing part is build into mkimage regardless of this
3176 option. The software based modular exponentiation is built into
3177 mkimage irrespective of this option.
3179 - bootcount support:
3180 CONFIG_BOOTCOUNT_LIMIT
3182 This enables the bootcounter support, see:
3183 http://www.denx.de/wiki/DULG/UBootBootCountLimit
3186 enable special bootcounter support on at91sam9xe based boards.
3188 enable special bootcounter support on blackfin based boards.
3190 enable special bootcounter support on da850 based boards.
3191 CONFIG_BOOTCOUNT_RAM
3192 enable support for the bootcounter in RAM
3193 CONFIG_BOOTCOUNT_I2C
3194 enable support for the bootcounter on an i2c (like RTC) device.
3195 CONFIG_SYS_I2C_RTC_ADDR = i2c chip address
3196 CONFIG_SYS_BOOTCOUNT_ADDR = i2c addr which is used for
3198 CONFIG_BOOTCOUNT_ALEN = address len
3200 - Show boot progress:
3201 CONFIG_SHOW_BOOT_PROGRESS
3203 Defining this option allows to add some board-
3204 specific code (calling a user-provided function
3205 "show_boot_progress(int)") that enables you to show
3206 the system's boot progress on some display (for
3207 example, some LED's) on your board. At the moment,
3208 the following checkpoints are implemented:
3211 Legacy uImage format:
3214 1 common/cmd_bootm.c before attempting to boot an image
3215 -1 common/cmd_bootm.c Image header has bad magic number
3216 2 common/cmd_bootm.c Image header has correct magic number
3217 -2 common/cmd_bootm.c Image header has bad checksum
3218 3 common/cmd_bootm.c Image header has correct checksum
3219 -3 common/cmd_bootm.c Image data has bad checksum
3220 4 common/cmd_bootm.c Image data has correct checksum
3221 -4 common/cmd_bootm.c Image is for unsupported architecture
3222 5 common/cmd_bootm.c Architecture check OK
3223 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi)
3224 6 common/cmd_bootm.c Image Type check OK
3225 -6 common/cmd_bootm.c gunzip uncompression error
3226 -7 common/cmd_bootm.c Unimplemented compression type
3227 7 common/cmd_bootm.c Uncompression OK
3228 8 common/cmd_bootm.c No uncompress/copy overwrite error
3229 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX)
3231 9 common/image.c Start initial ramdisk verification
3232 -10 common/image.c Ramdisk header has bad magic number
3233 -11 common/image.c Ramdisk header has bad checksum
3234 10 common/image.c Ramdisk header is OK
3235 -12 common/image.c Ramdisk data has bad checksum
3236 11 common/image.c Ramdisk data has correct checksum
3237 12 common/image.c Ramdisk verification complete, start loading
3238 -13 common/image.c Wrong Image Type (not PPC Linux ramdisk)
3239 13 common/image.c Start multifile image verification
3240 14 common/image.c No initial ramdisk, no multifile, continue.
3242 15 arch/<arch>/lib/bootm.c All preparation done, transferring control to OS
3244 -30 arch/powerpc/lib/board.c Fatal error, hang the system
3245 -31 post/post.c POST test failed, detected by post_output_backlog()
3246 -32 post/post.c POST test failed, detected by post_run_single()
3248 34 common/cmd_doc.c before loading a Image from a DOC device
3249 -35 common/cmd_doc.c Bad usage of "doc" command
3250 35 common/cmd_doc.c correct usage of "doc" command
3251 -36 common/cmd_doc.c No boot device
3252 36 common/cmd_doc.c correct boot device
3253 -37 common/cmd_doc.c Unknown Chip ID on boot device
3254 37 common/cmd_doc.c correct chip ID found, device available
3255 -38 common/cmd_doc.c Read Error on boot device
3256 38 common/cmd_doc.c reading Image header from DOC device OK
3257 -39 common/cmd_doc.c Image header has bad magic number
3258 39 common/cmd_doc.c Image header has correct magic number
3259 -40 common/cmd_doc.c Error reading Image from DOC device
3260 40 common/cmd_doc.c Image header has correct magic number
3261 41 common/cmd_ide.c before loading a Image from a IDE device
3262 -42 common/cmd_ide.c Bad usage of "ide" command
3263 42 common/cmd_ide.c correct usage of "ide" command
3264 -43 common/cmd_ide.c No boot device
3265 43 common/cmd_ide.c boot device found
3266 -44 common/cmd_ide.c Device not available
3267 44 common/cmd_ide.c Device available
3268 -45 common/cmd_ide.c wrong partition selected
3269 45 common/cmd_ide.c partition selected
3270 -46 common/cmd_ide.c Unknown partition table
3271 46 common/cmd_ide.c valid partition table found
3272 -47 common/cmd_ide.c Invalid partition type
3273 47 common/cmd_ide.c correct partition type
3274 -48 common/cmd_ide.c Error reading Image Header on boot device
3275 48 common/cmd_ide.c reading Image Header from IDE device OK
3276 -49 common/cmd_ide.c Image header has bad magic number
3277 49 common/cmd_ide.c Image header has correct magic number
3278 -50 common/cmd_ide.c Image header has bad checksum
3279 50 common/cmd_ide.c Image header has correct checksum
3280 -51 common/cmd_ide.c Error reading Image from IDE device
3281 51 common/cmd_ide.c reading Image from IDE device OK
3282 52 common/cmd_nand.c before loading a Image from a NAND device
3283 -53 common/cmd_nand.c Bad usage of "nand" command
3284 53 common/cmd_nand.c correct usage of "nand" command
3285 -54 common/cmd_nand.c No boot device
3286 54 common/cmd_nand.c boot device found
3287 -55 common/cmd_nand.c Unknown Chip ID on boot device
3288 55 common/cmd_nand.c correct chip ID found, device available
3289 -56 common/cmd_nand.c Error reading Image Header on boot device
3290 56 common/cmd_nand.c reading Image Header from NAND device OK
3291 -57 common/cmd_nand.c Image header has bad magic number
3292 57 common/cmd_nand.c Image header has correct magic number
3293 -58 common/cmd_nand.c Error reading Image from NAND device
3294 58 common/cmd_nand.c reading Image from NAND device OK
3296 -60 common/env_common.c Environment has a bad CRC, using default
3298 64 net/eth.c starting with Ethernet configuration.
3299 -64 net/eth.c no Ethernet found.
3300 65 net/eth.c Ethernet found.
3302 -80 common/cmd_net.c usage wrong
3303 80 common/cmd_net.c before calling net_loop()
3304 -81 common/cmd_net.c some error in net_loop() occurred
3305 81 common/cmd_net.c net_loop() back without error
3306 -82 common/cmd_net.c size == 0 (File with size 0 loaded)
3307 82 common/cmd_net.c trying automatic boot
3308 83 common/cmd_net.c running "source" command
3309 -83 common/cmd_net.c some error in automatic boot or "source" command
3310 84 common/cmd_net.c end without errors
3315 100 common/cmd_bootm.c Kernel FIT Image has correct format
3316 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format
3317 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration
3318 -101 common/cmd_bootm.c Can't get configuration for kernel subimage
3319 102 common/cmd_bootm.c Kernel unit name specified
3320 -103 common/cmd_bootm.c Can't get kernel subimage node offset
3321 103 common/cmd_bootm.c Found configuration node
3322 104 common/cmd_bootm.c Got kernel subimage node offset
3323 -104 common/cmd_bootm.c Kernel subimage hash verification failed
3324 105 common/cmd_bootm.c Kernel subimage hash verification OK
3325 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture
3326 106 common/cmd_bootm.c Architecture check OK
3327 -106 common/cmd_bootm.c Kernel subimage has wrong type
3328 107 common/cmd_bootm.c Kernel subimage type OK
3329 -107 common/cmd_bootm.c Can't get kernel subimage data/size
3330 108 common/cmd_bootm.c Got kernel subimage data/size
3331 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT)
3332 -109 common/cmd_bootm.c Can't get kernel subimage type
3333 -110 common/cmd_bootm.c Can't get kernel subimage comp
3334 -111 common/cmd_bootm.c Can't get kernel subimage os
3335 -112 common/cmd_bootm.c Can't get kernel subimage load address
3336 -113 common/cmd_bootm.c Image uncompress/copy overwrite error
3338 120 common/image.c Start initial ramdisk verification
3339 -120 common/image.c Ramdisk FIT image has incorrect format
3340 121 common/image.c Ramdisk FIT image has correct format
3341 122 common/image.c No ramdisk subimage unit name, using configuration
3342 -122 common/image.c Can't get configuration for ramdisk subimage
3343 123 common/image.c Ramdisk unit name specified
3344 -124 common/image.c Can't get ramdisk subimage node offset
3345 125 common/image.c Got ramdisk subimage node offset
3346 -125 common/image.c Ramdisk subimage hash verification failed
3347 126 common/image.c Ramdisk subimage hash verification OK
3348 -126 common/image.c Ramdisk subimage for unsupported architecture
3349 127 common/image.c Architecture check OK
3350 -127 common/image.c Can't get ramdisk subimage data/size
3351 128 common/image.c Got ramdisk subimage data/size
3352 129 common/image.c Can't get ramdisk load address
3353 -129 common/image.c Got ramdisk load address
3355 -130 common/cmd_doc.c Incorrect FIT image format
3356 131 common/cmd_doc.c FIT image format OK
3358 -140 common/cmd_ide.c Incorrect FIT image format
3359 141 common/cmd_ide.c FIT image format OK
3361 -150 common/cmd_nand.c Incorrect FIT image format
3362 151 common/cmd_nand.c FIT image format OK
3364 - legacy image format:
3365 CONFIG_IMAGE_FORMAT_LEGACY
3366 enables the legacy image format support in U-Boot.
3369 enabled if CONFIG_FIT_SIGNATURE is not defined.
3371 CONFIG_DISABLE_IMAGE_LEGACY
3372 disable the legacy image format
3374 This define is introduced, as the legacy image format is
3375 enabled per default for backward compatibility.
3377 - FIT image support:
3379 Enable support for the FIT uImage format.
3381 CONFIG_FIT_BEST_MATCH
3382 When no configuration is explicitly selected, default to the
3383 one whose fdt's compatibility field best matches that of
3384 U-Boot itself. A match is considered "best" if it matches the
3385 most specific compatibility entry of U-Boot's fdt's root node.
3386 The order of entries in the configuration's fdt is ignored.
3388 CONFIG_FIT_SIGNATURE
3389 This option enables signature verification of FIT uImages,
3390 using a hash signed and verified using RSA. If
3391 CONFIG_SHA_PROG_HW_ACCEL is defined, i.e support for progressive
3392 hashing is available using hardware, RSA library will use it.
3393 See doc/uImage.FIT/signature.txt for more details.
3395 WARNING: When relying on signed FIT images with required
3396 signature check the legacy image format is default
3397 disabled. If a board need legacy image format support
3398 enable this through CONFIG_IMAGE_FORMAT_LEGACY
3400 CONFIG_FIT_DISABLE_SHA256
3401 Supporting SHA256 hashes has quite an impact on binary size.
3402 For constrained systems sha256 hash support can be disabled
3405 - Standalone program support:
3406 CONFIG_STANDALONE_LOAD_ADDR
3408 This option defines a board specific value for the
3409 address where standalone program gets loaded, thus
3410 overwriting the architecture dependent default
3413 - Frame Buffer Address:
3416 Define CONFIG_FB_ADDR if you want to use specific
3417 address for frame buffer. This is typically the case
3418 when using a graphics controller has separate video
3419 memory. U-Boot will then place the frame buffer at
3420 the given address instead of dynamically reserving it
3421 in system RAM by calling lcd_setmem(), which grabs
3422 the memory for the frame buffer depending on the
3423 configured panel size.
3425 Please see board_init_f function.
3427 - Automatic software updates via TFTP server
3429 CONFIG_UPDATE_TFTP_CNT_MAX
3430 CONFIG_UPDATE_TFTP_MSEC_MAX
3432 These options enable and control the auto-update feature;
3433 for a more detailed description refer to doc/README.update.
3435 - MTD Support (mtdparts command, UBI support)
3438 Adds the MTD device infrastructure from the Linux kernel.
3439 Needed for mtdparts command support.
3441 CONFIG_MTD_PARTITIONS
3443 Adds the MTD partitioning infrastructure from the Linux
3444 kernel. Needed for UBI support.
3449 Adds commands for interacting with MTD partitions formatted
3450 with the UBI flash translation layer
3452 Requires also defining CONFIG_RBTREE
3454 CONFIG_UBI_SILENCE_MSG
3456 Make the verbose messages from UBI stop printing. This leaves
3457 warnings and errors enabled.
3460 CONFIG_MTD_UBI_WL_THRESHOLD
3461 This parameter defines the maximum difference between the highest
3462 erase counter value and the lowest erase counter value of eraseblocks
3463 of UBI devices. When this threshold is exceeded, UBI starts performing
3464 wear leveling by means of moving data from eraseblock with low erase
3465 counter to eraseblocks with high erase counter.
3467 The default value should be OK for SLC NAND flashes, NOR flashes and
3468 other flashes which have eraseblock life-cycle 100000 or more.
3469 However, in case of MLC NAND flashes which typically have eraseblock
3470 life-cycle less than 10000, the threshold should be lessened (e.g.,
3471 to 128 or 256, although it does not have to be power of 2).
3475 CONFIG_MTD_UBI_BEB_LIMIT
3476 This option specifies the maximum bad physical eraseblocks UBI
3477 expects on the MTD device (per 1024 eraseblocks). If the
3478 underlying flash does not admit of bad eraseblocks (e.g. NOR
3479 flash), this value is ignored.
3481 NAND datasheets often specify the minimum and maximum NVM
3482 (Number of Valid Blocks) for the flashes' endurance lifetime.
3483 The maximum expected bad eraseblocks per 1024 eraseblocks
3484 then can be calculated as "1024 * (1 - MinNVB / MaxNVB)",
3485 which gives 20 for most NANDs (MaxNVB is basically the total
3486 count of eraseblocks on the chip).
3488 To put it differently, if this value is 20, UBI will try to
3489 reserve about 1.9% of physical eraseblocks for bad blocks
3490 handling. And that will be 1.9% of eraseblocks on the entire
3491 NAND chip, not just the MTD partition UBI attaches. This means
3492 that if you have, say, a NAND flash chip admits maximum 40 bad
3493 eraseblocks, and it is split on two MTD partitions of the same
3494 size, UBI will reserve 40 eraseblocks when attaching a
3499 CONFIG_MTD_UBI_FASTMAP
3500 Fastmap is a mechanism which allows attaching an UBI device
3501 in nearly constant time. Instead of scanning the whole MTD device it
3502 only has to locate a checkpoint (called fastmap) on the device.
3503 The on-flash fastmap contains all information needed to attach
3504 the device. Using fastmap makes only sense on large devices where
3505 attaching by scanning takes long. UBI will not automatically install
3506 a fastmap on old images, but you can set the UBI parameter
3507 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT to 1 if you want so. Please note
3508 that fastmap-enabled images are still usable with UBI implementations
3509 without fastmap support. On typical flash devices the whole fastmap
3510 fits into one PEB. UBI will reserve PEBs to hold two fastmaps.
3512 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT
3513 Set this parameter to enable fastmap automatically on images
3520 Adds commands for interacting with UBI volumes formatted as
3521 UBIFS. UBIFS is read-only in u-boot.
3523 Requires UBI support as well as CONFIG_LZO
3525 CONFIG_UBIFS_SILENCE_MSG
3527 Make the verbose messages from UBIFS stop printing. This leaves
3528 warnings and errors enabled.
3532 Enable building of SPL globally.
3535 LDSCRIPT for linking the SPL binary.
3537 CONFIG_SPL_MAX_FOOTPRINT
3538 Maximum size in memory allocated to the SPL, BSS included.
3539 When defined, the linker checks that the actual memory
3540 used by SPL from _start to __bss_end does not exceed it.
3541 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
3542 must not be both defined at the same time.
3545 Maximum size of the SPL image (text, data, rodata, and
3546 linker lists sections), BSS excluded.
3547 When defined, the linker checks that the actual size does
3550 CONFIG_SPL_TEXT_BASE
3551 TEXT_BASE for linking the SPL binary.
3553 CONFIG_SPL_RELOC_TEXT_BASE
3554 Address to relocate to. If unspecified, this is equal to
3555 CONFIG_SPL_TEXT_BASE (i.e. no relocation is done).
3557 CONFIG_SPL_BSS_START_ADDR
3558 Link address for the BSS within the SPL binary.
3560 CONFIG_SPL_BSS_MAX_SIZE
3561 Maximum size in memory allocated to the SPL BSS.
3562 When defined, the linker checks that the actual memory used
3563 by SPL from __bss_start to __bss_end does not exceed it.
3564 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
3565 must not be both defined at the same time.
3568 Adress of the start of the stack SPL will use
3570 CONFIG_SPL_PANIC_ON_RAW_IMAGE
3571 When defined, SPL will panic() if the image it has
3572 loaded does not have a signature.
3573 Defining this is useful when code which loads images
3574 in SPL cannot guarantee that absolutely all read errors
3576 An example is the LPC32XX MLC NAND driver, which will
3577 consider that a completely unreadable NAND block is bad,
3578 and thus should be skipped silently.
3580 CONFIG_SPL_RELOC_STACK
3581 Adress of the start of the stack SPL will use after
3582 relocation. If unspecified, this is equal to
3585 CONFIG_SYS_SPL_MALLOC_START
3586 Starting address of the malloc pool used in SPL.
3588 CONFIG_SYS_SPL_MALLOC_SIZE
3589 The size of the malloc pool used in SPL.
3591 CONFIG_SPL_FRAMEWORK
3592 Enable the SPL framework under common/. This framework
3593 supports MMC, NAND and YMODEM loading of U-Boot and NAND
3594 NAND loading of the Linux Kernel.
3597 Enable booting directly to an OS from SPL.
3598 See also: doc/README.falcon
3600 CONFIG_SPL_DISPLAY_PRINT
3601 For ARM, enable an optional function to print more information
3602 about the running system.
3604 CONFIG_SPL_INIT_MINIMAL
3605 Arch init code should be built for a very small image
3607 CONFIG_SPL_LIBCOMMON_SUPPORT
3608 Support for common/libcommon.o in SPL binary
3610 CONFIG_SPL_LIBDISK_SUPPORT
3611 Support for disk/libdisk.o in SPL binary
3613 CONFIG_SPL_I2C_SUPPORT
3614 Support for drivers/i2c/libi2c.o in SPL binary
3616 CONFIG_SPL_GPIO_SUPPORT
3617 Support for drivers/gpio/libgpio.o in SPL binary
3619 CONFIG_SPL_MMC_SUPPORT
3620 Support for drivers/mmc/libmmc.o in SPL binary
3622 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_SECTOR,
3623 CONFIG_SYS_U_BOOT_MAX_SIZE_SECTORS,
3624 Address and partition on the MMC to load U-Boot from
3625 when the MMC is being used in raw mode.
3627 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_PARTITION
3628 Partition on the MMC to load U-Boot from when the MMC is being
3631 CONFIG_SYS_MMCSD_RAW_MODE_KERNEL_SECTOR
3632 Sector to load kernel uImage from when MMC is being
3633 used in raw mode (for Falcon mode)
3635 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTOR,
3636 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTORS
3637 Sector and number of sectors to load kernel argument
3638 parameters from when MMC is being used in raw mode
3641 CONFIG_SYS_MMCSD_FS_BOOT_PARTITION
3642 Partition on the MMC to load U-Boot from when the MMC is being
3645 CONFIG_SPL_FAT_SUPPORT
3646 Support for fs/fat/libfat.o in SPL binary
3648 CONFIG_SPL_EXT_SUPPORT
3649 Support for EXT filesystem in SPL binary
3651 CONFIG_SPL_FS_LOAD_PAYLOAD_NAME
3652 Filename to read to load U-Boot when reading from filesystem
3654 CONFIG_SPL_FS_LOAD_KERNEL_NAME
3655 Filename to read to load kernel uImage when reading
3656 from filesystem (for Falcon mode)
3658 CONFIG_SPL_FS_LOAD_ARGS_NAME
3659 Filename to read to load kernel argument parameters
3660 when reading from filesystem (for Falcon mode)
3662 CONFIG_SPL_MPC83XX_WAIT_FOR_NAND
3663 Set this for NAND SPL on PPC mpc83xx targets, so that
3664 start.S waits for the rest of the SPL to load before
3665 continuing (the hardware starts execution after just
3666 loading the first page rather than the full 4K).
3668 CONFIG_SPL_SKIP_RELOCATE
3669 Avoid SPL relocation
3671 CONFIG_SPL_NAND_BASE
3672 Include nand_base.c in the SPL. Requires
3673 CONFIG_SPL_NAND_DRIVERS.
3675 CONFIG_SPL_NAND_DRIVERS
3676 SPL uses normal NAND drivers, not minimal drivers.
3679 Include standard software ECC in the SPL
3681 CONFIG_SPL_NAND_SIMPLE
3682 Support for NAND boot using simple NAND drivers that
3683 expose the cmd_ctrl() interface.
3685 CONFIG_SPL_MTD_SUPPORT
3686 Support for the MTD subsystem within SPL. Useful for
3687 environment on NAND support within SPL.
3689 CONFIG_SPL_NAND_RAW_ONLY
3690 Support to boot only raw u-boot.bin images. Use this only
3691 if you need to save space.
3693 CONFIG_SPL_MPC8XXX_INIT_DDR_SUPPORT
3694 Set for the SPL on PPC mpc8xxx targets, support for
3695 drivers/ddr/fsl/libddr.o in SPL binary.
3697 CONFIG_SPL_COMMON_INIT_DDR
3698 Set for common ddr init with serial presence detect in
3701 CONFIG_SYS_NAND_5_ADDR_CYCLE, CONFIG_SYS_NAND_PAGE_COUNT,
3702 CONFIG_SYS_NAND_PAGE_SIZE, CONFIG_SYS_NAND_OOBSIZE,
3703 CONFIG_SYS_NAND_BLOCK_SIZE, CONFIG_SYS_NAND_BAD_BLOCK_POS,
3704 CONFIG_SYS_NAND_ECCPOS, CONFIG_SYS_NAND_ECCSIZE,
3705 CONFIG_SYS_NAND_ECCBYTES
3706 Defines the size and behavior of the NAND that SPL uses
3709 CONFIG_SPL_NAND_BOOT
3710 Add support NAND boot
3712 CONFIG_SYS_NAND_U_BOOT_OFFS
3713 Location in NAND to read U-Boot from
3715 CONFIG_SYS_NAND_U_BOOT_DST
3716 Location in memory to load U-Boot to
3718 CONFIG_SYS_NAND_U_BOOT_SIZE
3719 Size of image to load
3721 CONFIG_SYS_NAND_U_BOOT_START
3722 Entry point in loaded image to jump to
3724 CONFIG_SYS_NAND_HW_ECC_OOBFIRST
3725 Define this if you need to first read the OOB and then the
3726 data. This is used, for example, on davinci platforms.
3728 CONFIG_SPL_OMAP3_ID_NAND
3729 Support for an OMAP3-specific set of functions to return the
3730 ID and MFR of the first attached NAND chip, if present.
3732 CONFIG_SPL_SERIAL_SUPPORT
3733 Support for drivers/serial/libserial.o in SPL binary
3735 CONFIG_SPL_SPI_FLASH_SUPPORT
3736 Support for drivers/mtd/spi/libspi_flash.o in SPL binary
3738 CONFIG_SPL_SPI_SUPPORT
3739 Support for drivers/spi/libspi.o in SPL binary
3741 CONFIG_SPL_RAM_DEVICE
3742 Support for running image already present in ram, in SPL binary
3744 CONFIG_SPL_LIBGENERIC_SUPPORT
3745 Support for lib/libgeneric.o in SPL binary
3747 CONFIG_SPL_ENV_SUPPORT
3748 Support for the environment operating in SPL binary
3750 CONFIG_SPL_NET_SUPPORT
3751 Support for the net/libnet.o in SPL binary.
3752 It conflicts with SPL env from storage medium specified by
3753 CONFIG_ENV_IS_xxx but CONFIG_ENV_IS_NOWHERE
3756 Image offset to which the SPL should be padded before appending
3757 the SPL payload. By default, this is defined as
3758 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3759 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3760 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3763 Final target image containing SPL and payload. Some SPLs
3764 use an arch-specific makefile fragment instead, for
3765 example if more than one image needs to be produced.
3767 CONFIG_FIT_SPL_PRINT
3768 Printing information about a FIT image adds quite a bit of
3769 code to SPL. So this is normally disabled in SPL. Use this
3770 option to re-enable it. This will affect the output of the
3771 bootm command when booting a FIT image.
3775 Enable building of TPL globally.
3778 Image offset to which the TPL should be padded before appending
3779 the TPL payload. By default, this is defined as
3780 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3781 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3782 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3787 [so far only for SMDK2400 boards]
3789 - Modem support enable:
3790 CONFIG_MODEM_SUPPORT
3792 - RTS/CTS Flow control enable:
3795 - Modem debug support:
3796 CONFIG_MODEM_SUPPORT_DEBUG
3798 Enables debugging stuff (char screen[1024], dbg())
3799 for modem support. Useful only with BDI2000.
3801 - Interrupt support (PPC):
3803 There are common interrupt_init() and timer_interrupt()
3804 for all PPC archs. interrupt_init() calls interrupt_init_cpu()
3805 for CPU specific initialization. interrupt_init_cpu()
3806 should set decrementer_count to appropriate value. If
3807 CPU resets decrementer automatically after interrupt
3808 (ppc4xx) it should set decrementer_count to zero.
3809 timer_interrupt() calls timer_interrupt_cpu() for CPU
3810 specific handling. If board has watchdog / status_led
3811 / other_activity_monitor it works automatically from
3812 general timer_interrupt().
3816 In the target system modem support is enabled when a
3817 specific key (key combination) is pressed during
3818 power-on. Otherwise U-Boot will boot normally
3819 (autoboot). The key_pressed() function is called from
3820 board_init(). Currently key_pressed() is a dummy
3821 function, returning 1 and thus enabling modem
3824 If there are no modem init strings in the
3825 environment, U-Boot proceed to autoboot; the
3826 previous output (banner, info printfs) will be
3829 See also: doc/README.Modem
3831 Board initialization settings:
3832 ------------------------------
3834 During Initialization u-boot calls a number of board specific functions
3835 to allow the preparation of board specific prerequisites, e.g. pin setup
3836 before drivers are initialized. To enable these callbacks the
3837 following configuration macros have to be defined. Currently this is
3838 architecture specific, so please check arch/your_architecture/lib/board.c
3839 typically in board_init_f() and board_init_r().
3841 - CONFIG_BOARD_EARLY_INIT_F: Call board_early_init_f()
3842 - CONFIG_BOARD_EARLY_INIT_R: Call board_early_init_r()
3843 - CONFIG_BOARD_LATE_INIT: Call board_late_init()
3844 - CONFIG_BOARD_POSTCLK_INIT: Call board_postclk_init()
3846 Configuration Settings:
3847 -----------------------
3849 - CONFIG_SYS_SUPPORT_64BIT_DATA: Defined automatically if compiled as 64-bit.
3850 Optionally it can be defined to support 64-bit memory commands.
3852 - CONFIG_SYS_LONGHELP: Defined when you want long help messages included;
3853 undefine this when you're short of memory.
3855 - CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default
3856 width of the commands listed in the 'help' command output.
3858 - CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to
3859 prompt for user input.
3861 - CONFIG_SYS_CBSIZE: Buffer size for input from the Console
3863 - CONFIG_SYS_PBSIZE: Buffer size for Console output
3865 - CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands
3867 - CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to
3868 the application (usually a Linux kernel) when it is
3871 - CONFIG_SYS_BAUDRATE_TABLE:
3872 List of legal baudrate settings for this board.
3874 - CONFIG_SYS_CONSOLE_INFO_QUIET
3875 Suppress display of console information at boot.
3877 - CONFIG_SYS_CONSOLE_IS_IN_ENV
3878 If the board specific function
3879 extern int overwrite_console (void);
3880 returns 1, the stdin, stderr and stdout are switched to the
3881 serial port, else the settings in the environment are used.
3883 - CONFIG_SYS_CONSOLE_OVERWRITE_ROUTINE
3884 Enable the call to overwrite_console().
3886 - CONFIG_SYS_CONSOLE_ENV_OVERWRITE
3887 Enable overwrite of previous console environment settings.
3889 - CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END:
3890 Begin and End addresses of the area used by the
3893 - CONFIG_SYS_ALT_MEMTEST:
3894 Enable an alternate, more extensive memory test.
3896 - CONFIG_SYS_MEMTEST_SCRATCH:
3897 Scratch address used by the alternate memory test
3898 You only need to set this if address zero isn't writeable
3900 - CONFIG_SYS_MEM_TOP_HIDE (PPC only):
3901 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header,
3902 this specified memory area will get subtracted from the top
3903 (end) of RAM and won't get "touched" at all by U-Boot. By
3904 fixing up gd->ram_size the Linux kernel should gets passed
3905 the now "corrected" memory size and won't touch it either.
3906 This should work for arch/ppc and arch/powerpc. Only Linux
3907 board ports in arch/powerpc with bootwrapper support that
3908 recalculate the memory size from the SDRAM controller setup
3909 will have to get fixed in Linux additionally.
3911 This option can be used as a workaround for the 440EPx/GRx
3912 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't
3915 WARNING: Please make sure that this value is a multiple of
3916 the Linux page size (normally 4k). If this is not the case,
3917 then the end address of the Linux memory will be located at a
3918 non page size aligned address and this could cause major
3921 - CONFIG_SYS_LOADS_BAUD_CHANGE:
3922 Enable temporary baudrate change while serial download
3924 - CONFIG_SYS_SDRAM_BASE:
3925 Physical start address of SDRAM. _Must_ be 0 here.
3927 - CONFIG_SYS_MBIO_BASE:
3928 Physical start address of Motherboard I/O (if using a
3931 - CONFIG_SYS_FLASH_BASE:
3932 Physical start address of Flash memory.
3934 - CONFIG_SYS_MONITOR_BASE:
3935 Physical start address of boot monitor code (set by
3936 make config files to be same as the text base address
3937 (CONFIG_SYS_TEXT_BASE) used when linking) - same as
3938 CONFIG_SYS_FLASH_BASE when booting from flash.
3940 - CONFIG_SYS_MONITOR_LEN:
3941 Size of memory reserved for monitor code, used to
3942 determine _at_compile_time_ (!) if the environment is
3943 embedded within the U-Boot image, or in a separate
3946 - CONFIG_SYS_MALLOC_LEN:
3947 Size of DRAM reserved for malloc() use.
3949 - CONFIG_SYS_MALLOC_F_LEN
3950 Size of the malloc() pool for use before relocation. If
3951 this is defined, then a very simple malloc() implementation
3952 will become available before relocation. The address is just
3953 below the global data, and the stack is moved down to make
3956 This feature allocates regions with increasing addresses
3957 within the region. calloc() is supported, but realloc()
3958 is not available. free() is supported but does nothing.
3959 The memory will be freed (or in fact just forgotten) when
3960 U-Boot relocates itself.
3962 Pre-relocation malloc() is only supported on ARM and sandbox
3963 at present but is fairly easy to enable for other archs.
3965 - CONFIG_SYS_MALLOC_SIMPLE
3966 Provides a simple and small malloc() and calloc() for those
3967 boards which do not use the full malloc in SPL (which is
3968 enabled with CONFIG_SYS_SPL_MALLOC_START).
3970 - CONFIG_SYS_NONCACHED_MEMORY:
3971 Size of non-cached memory area. This area of memory will be
3972 typically located right below the malloc() area and mapped
3973 uncached in the MMU. This is useful for drivers that would
3974 otherwise require a lot of explicit cache maintenance. For
3975 some drivers it's also impossible to properly maintain the
3976 cache. For example if the regions that need to be flushed
3977 are not a multiple of the cache-line size, *and* padding
3978 cannot be allocated between the regions to align them (i.e.
3979 if the HW requires a contiguous array of regions, and the
3980 size of each region is not cache-aligned), then a flush of
3981 one region may result in overwriting data that hardware has
3982 written to another region in the same cache-line. This can
3983 happen for example in network drivers where descriptors for
3984 buffers are typically smaller than the CPU cache-line (e.g.
3985 16 bytes vs. 32 or 64 bytes).
3987 Non-cached memory is only supported on 32-bit ARM at present.
3989 - CONFIG_SYS_BOOTM_LEN:
3990 Normally compressed uImages are limited to an
3991 uncompressed size of 8 MBytes. If this is not enough,
3992 you can define CONFIG_SYS_BOOTM_LEN in your board config file
3993 to adjust this setting to your needs.
3995 - CONFIG_SYS_BOOTMAPSZ:
3996 Maximum size of memory mapped by the startup code of
3997 the Linux kernel; all data that must be processed by
3998 the Linux kernel (bd_info, boot arguments, FDT blob if
3999 used) must be put below this limit, unless "bootm_low"
4000 environment variable is defined and non-zero. In such case
4001 all data for the Linux kernel must be between "bootm_low"
4002 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ. The environment
4003 variable "bootm_mapsize" will override the value of
4004 CONFIG_SYS_BOOTMAPSZ. If CONFIG_SYS_BOOTMAPSZ is undefined,
4005 then the value in "bootm_size" will be used instead.
4007 - CONFIG_SYS_BOOT_RAMDISK_HIGH:
4008 Enable initrd_high functionality. If defined then the
4009 initrd_high feature is enabled and the bootm ramdisk subcommand
4012 - CONFIG_SYS_BOOT_GET_CMDLINE:
4013 Enables allocating and saving kernel cmdline in space between
4014 "bootm_low" and "bootm_low" + BOOTMAPSZ.
4016 - CONFIG_SYS_BOOT_GET_KBD:
4017 Enables allocating and saving a kernel copy of the bd_info in
4018 space between "bootm_low" and "bootm_low" + BOOTMAPSZ.
4020 - CONFIG_SYS_MAX_FLASH_BANKS:
4021 Max number of Flash memory banks
4023 - CONFIG_SYS_MAX_FLASH_SECT:
4024 Max number of sectors on a Flash chip
4026 - CONFIG_SYS_FLASH_ERASE_TOUT:
4027 Timeout for Flash erase operations (in ms)
4029 - CONFIG_SYS_FLASH_WRITE_TOUT:
4030 Timeout for Flash write operations (in ms)
4032 - CONFIG_SYS_FLASH_LOCK_TOUT
4033 Timeout for Flash set sector lock bit operation (in ms)
4035 - CONFIG_SYS_FLASH_UNLOCK_TOUT
4036 Timeout for Flash clear lock bits operation (in ms)
4038 - CONFIG_SYS_FLASH_PROTECTION
4039 If defined, hardware flash sectors protection is used
4040 instead of U-Boot software protection.
4042 - CONFIG_SYS_DIRECT_FLASH_TFTP:
4044 Enable TFTP transfers directly to flash memory;
4045 without this option such a download has to be
4046 performed in two steps: (1) download to RAM, and (2)
4047 copy from RAM to flash.
4049 The two-step approach is usually more reliable, since
4050 you can check if the download worked before you erase
4051 the flash, but in some situations (when system RAM is
4052 too limited to allow for a temporary copy of the
4053 downloaded image) this option may be very useful.
4055 - CONFIG_SYS_FLASH_CFI:
4056 Define if the flash driver uses extra elements in the
4057 common flash structure for storing flash geometry.
4059 - CONFIG_FLASH_CFI_DRIVER
4060 This option also enables the building of the cfi_flash driver
4061 in the drivers directory
4063 - CONFIG_FLASH_CFI_MTD
4064 This option enables the building of the cfi_mtd driver
4065 in the drivers directory. The driver exports CFI flash
4068 - CONFIG_SYS_FLASH_USE_BUFFER_WRITE
4069 Use buffered writes to flash.
4071 - CONFIG_FLASH_SPANSION_S29WS_N
4072 s29ws-n MirrorBit flash has non-standard addresses for buffered
4075 - CONFIG_SYS_FLASH_QUIET_TEST
4076 If this option is defined, the common CFI flash doesn't
4077 print it's warning upon not recognized FLASH banks. This
4078 is useful, if some of the configured banks are only
4079 optionally available.
4081 - CONFIG_FLASH_SHOW_PROGRESS
4082 If defined (must be an integer), print out countdown
4083 digits and dots. Recommended value: 45 (9..1) for 80
4084 column displays, 15 (3..1) for 40 column displays.
4086 - CONFIG_FLASH_VERIFY
4087 If defined, the content of the flash (destination) is compared
4088 against the source after the write operation. An error message
4089 will be printed when the contents are not identical.
4090 Please note that this option is useless in nearly all cases,
4091 since such flash programming errors usually are detected earlier
4092 while unprotecting/erasing/programming. Please only enable
4093 this option if you really know what you are doing.
4095 - CONFIG_SYS_RX_ETH_BUFFER:
4096 Defines the number of Ethernet receive buffers. On some
4097 Ethernet controllers it is recommended to set this value
4098 to 8 or even higher (EEPRO100 or 405 EMAC), since all
4099 buffers can be full shortly after enabling the interface
4100 on high Ethernet traffic.
4101 Defaults to 4 if not defined.
4103 - CONFIG_ENV_MAX_ENTRIES
4105 Maximum number of entries in the hash table that is used
4106 internally to store the environment settings. The default
4107 setting is supposed to be generous and should work in most
4108 cases. This setting can be used to tune behaviour; see
4109 lib/hashtable.c for details.
4111 - CONFIG_ENV_FLAGS_LIST_DEFAULT
4112 - CONFIG_ENV_FLAGS_LIST_STATIC
4113 Enable validation of the values given to environment variables when
4114 calling env set. Variables can be restricted to only decimal,
4115 hexadecimal, or boolean. If CONFIG_CMD_NET is also defined,
4116 the variables can also be restricted to IP address or MAC address.
4118 The format of the list is:
4119 type_attribute = [s|d|x|b|i|m]
4120 access_attribute = [a|r|o|c]
4121 attributes = type_attribute[access_attribute]
4122 entry = variable_name[:attributes]
4125 The type attributes are:
4126 s - String (default)
4129 b - Boolean ([1yYtT|0nNfF])
4133 The access attributes are:
4139 - CONFIG_ENV_FLAGS_LIST_DEFAULT
4140 Define this to a list (string) to define the ".flags"
4141 environment variable in the default or embedded environment.
4143 - CONFIG_ENV_FLAGS_LIST_STATIC
4144 Define this to a list (string) to define validation that
4145 should be done if an entry is not found in the ".flags"
4146 environment variable. To override a setting in the static
4147 list, simply add an entry for the same variable name to the
4150 If CONFIG_REGEX is defined, the variable_name above is evaluated as a
4151 regular expression. This allows multiple variables to define the same
4152 flags without explicitly listing them for each variable.
4154 - CONFIG_ENV_ACCESS_IGNORE_FORCE
4155 If defined, don't allow the -f switch to env set override variable
4158 - CONFIG_SYS_GENERIC_BOARD
4159 This selects the architecture-generic board system instead of the
4160 architecture-specific board files. It is intended to move boards
4161 to this new framework over time. Defining this will disable the
4162 arch/foo/lib/board.c file and use common/board_f.c and
4163 common/board_r.c instead. To use this option your architecture
4164 must support it (i.e. must select HAVE_GENERIC_BOARD in arch/Kconfig).
4165 If you find problems enabling this option on your board please report
4166 the problem and send patches!
4168 - CONFIG_OMAP_PLATFORM_RESET_TIME_MAX_USEC (OMAP only)
4169 This is set by OMAP boards for the max time that reset should
4170 be asserted. See doc/README.omap-reset-time for details on how
4171 the value can be calculated on a given board.
4174 If stdint.h is available with your toolchain you can define this
4175 option to enable it. You can provide option 'USE_STDINT=1' when
4176 building U-Boot to enable this.
4178 The following definitions that deal with the placement and management
4179 of environment data (variable area); in general, we support the
4180 following configurations:
4182 - CONFIG_BUILD_ENVCRC:
4184 Builds up envcrc with the target environment so that external utils
4185 may easily extract it and embed it in final U-Boot images.
4187 - CONFIG_ENV_IS_IN_FLASH:
4189 Define this if the environment is in flash memory.
4191 a) The environment occupies one whole flash sector, which is
4192 "embedded" in the text segment with the U-Boot code. This
4193 happens usually with "bottom boot sector" or "top boot
4194 sector" type flash chips, which have several smaller
4195 sectors at the start or the end. For instance, such a
4196 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In
4197 such a case you would place the environment in one of the
4198 4 kB sectors - with U-Boot code before and after it. With
4199 "top boot sector" type flash chips, you would put the
4200 environment in one of the last sectors, leaving a gap
4201 between U-Boot and the environment.
4203 - CONFIG_ENV_OFFSET:
4205 Offset of environment data (variable area) to the
4206 beginning of flash memory; for instance, with bottom boot
4207 type flash chips the second sector can be used: the offset
4208 for this sector is given here.
4210 CONFIG_ENV_OFFSET is used relative to CONFIG_SYS_FLASH_BASE.
4214 This is just another way to specify the start address of
4215 the flash sector containing the environment (instead of
4218 - CONFIG_ENV_SECT_SIZE:
4220 Size of the sector containing the environment.
4223 b) Sometimes flash chips have few, equal sized, BIG sectors.
4224 In such a case you don't want to spend a whole sector for
4229 If you use this in combination with CONFIG_ENV_IS_IN_FLASH
4230 and CONFIG_ENV_SECT_SIZE, you can specify to use only a part
4231 of this flash sector for the environment. This saves
4232 memory for the RAM copy of the environment.
4234 It may also save flash memory if you decide to use this
4235 when your environment is "embedded" within U-Boot code,
4236 since then the remainder of the flash sector could be used
4237 for U-Boot code. It should be pointed out that this is
4238 STRONGLY DISCOURAGED from a robustness point of view:
4239 updating the environment in flash makes it always
4240 necessary to erase the WHOLE sector. If something goes
4241 wrong before the contents has been restored from a copy in
4242 RAM, your target system will be dead.
4244 - CONFIG_ENV_ADDR_REDUND
4245 CONFIG_ENV_SIZE_REDUND
4247 These settings describe a second storage area used to hold
4248 a redundant copy of the environment data, so that there is
4249 a valid backup copy in case there is a power failure during
4250 a "saveenv" operation.
4252 BE CAREFUL! Any changes to the flash layout, and some changes to the
4253 source code will make it necessary to adapt <board>/u-boot.lds*
4257 - CONFIG_ENV_IS_IN_NVRAM:
4259 Define this if you have some non-volatile memory device
4260 (NVRAM, battery buffered SRAM) which you want to use for the
4266 These two #defines are used to determine the memory area you
4267 want to use for environment. It is assumed that this memory
4268 can just be read and written to, without any special
4271 BE CAREFUL! The first access to the environment happens quite early
4272 in U-Boot initialization (when we try to get the setting of for the
4273 console baudrate). You *MUST* have mapped your NVRAM area then, or
4276 Please note that even with NVRAM we still use a copy of the
4277 environment in RAM: we could work on NVRAM directly, but we want to
4278 keep settings there always unmodified except somebody uses "saveenv"
4279 to save the current settings.
4282 - CONFIG_ENV_IS_IN_EEPROM:
4284 Use this if you have an EEPROM or similar serial access
4285 device and a driver for it.
4287 - CONFIG_ENV_OFFSET:
4290 These two #defines specify the offset and size of the
4291 environment area within the total memory of your EEPROM.
4293 - CONFIG_SYS_I2C_EEPROM_ADDR:
4294 If defined, specified the chip address of the EEPROM device.
4295 The default address is zero.
4297 - CONFIG_SYS_I2C_EEPROM_BUS:
4298 If defined, specified the i2c bus of the EEPROM device.
4300 - CONFIG_SYS_EEPROM_PAGE_WRITE_BITS:
4301 If defined, the number of bits used to address bytes in a
4302 single page in the EEPROM device. A 64 byte page, for example
4303 would require six bits.
4305 - CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS:
4306 If defined, the number of milliseconds to delay between
4307 page writes. The default is zero milliseconds.
4309 - CONFIG_SYS_I2C_EEPROM_ADDR_LEN:
4310 The length in bytes of the EEPROM memory array address. Note
4311 that this is NOT the chip address length!
4313 - CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW:
4314 EEPROM chips that implement "address overflow" are ones
4315 like Catalyst 24WC04/08/16 which has 9/10/11 bits of
4316 address and the extra bits end up in the "chip address" bit
4317 slots. This makes a 24WC08 (1Kbyte) chip look like four 256
4320 Note that we consider the length of the address field to
4321 still be one byte because the extra address bits are hidden
4322 in the chip address.
4324 - CONFIG_SYS_EEPROM_SIZE:
4325 The size in bytes of the EEPROM device.
4327 - CONFIG_ENV_EEPROM_IS_ON_I2C
4328 define this, if you have I2C and SPI activated, and your
4329 EEPROM, which holds the environment, is on the I2C bus.
4331 - CONFIG_I2C_ENV_EEPROM_BUS
4332 if you have an Environment on an EEPROM reached over
4333 I2C muxes, you can define here, how to reach this
4334 EEPROM. For example:
4336 #define CONFIG_I2C_ENV_EEPROM_BUS 1
4338 EEPROM which holds the environment, is reached over
4339 a pca9547 i2c mux with address 0x70, channel 3.
4341 - CONFIG_ENV_IS_IN_DATAFLASH:
4343 Define this if you have a DataFlash memory device which you
4344 want to use for the environment.
4346 - CONFIG_ENV_OFFSET:
4350 These three #defines specify the offset and size of the
4351 environment area within the total memory of your DataFlash placed
4352 at the specified address.
4354 - CONFIG_ENV_IS_IN_SPI_FLASH:
4356 Define this if you have a SPI Flash memory device which you
4357 want to use for the environment.
4359 - CONFIG_ENV_OFFSET:
4362 These two #defines specify the offset and size of the
4363 environment area within the SPI Flash. CONFIG_ENV_OFFSET must be
4364 aligned to an erase sector boundary.
4366 - CONFIG_ENV_SECT_SIZE:
4368 Define the SPI flash's sector size.
4370 - CONFIG_ENV_OFFSET_REDUND (optional):
4372 This setting describes a second storage area of CONFIG_ENV_SIZE
4373 size used to hold a redundant copy of the environment data, so
4374 that there is a valid backup copy in case there is a power failure
4375 during a "saveenv" operation. CONFIG_ENV_OFFSET_RENDUND must be
4376 aligned to an erase sector boundary.
4378 - CONFIG_ENV_SPI_BUS (optional):
4379 - CONFIG_ENV_SPI_CS (optional):
4381 Define the SPI bus and chip select. If not defined they will be 0.
4383 - CONFIG_ENV_SPI_MAX_HZ (optional):
4385 Define the SPI max work clock. If not defined then use 1MHz.
4387 - CONFIG_ENV_SPI_MODE (optional):
4389 Define the SPI work mode. If not defined then use SPI_MODE_3.
4391 - CONFIG_ENV_IS_IN_REMOTE:
4393 Define this if you have a remote memory space which you
4394 want to use for the local device's environment.
4399 These two #defines specify the address and size of the
4400 environment area within the remote memory space. The
4401 local device can get the environment from remote memory
4402 space by SRIO or PCIE links.
4404 BE CAREFUL! For some special cases, the local device can not use
4405 "saveenv" command. For example, the local device will get the
4406 environment stored in a remote NOR flash by SRIO or PCIE link,
4407 but it can not erase, write this NOR flash by SRIO or PCIE interface.
4409 - CONFIG_ENV_IS_IN_NAND:
4411 Define this if you have a NAND device which you want to use
4412 for the environment.
4414 - CONFIG_ENV_OFFSET:
4417 These two #defines specify the offset and size of the environment
4418 area within the first NAND device. CONFIG_ENV_OFFSET must be
4419 aligned to an erase block boundary.
4421 - CONFIG_ENV_OFFSET_REDUND (optional):
4423 This setting describes a second storage area of CONFIG_ENV_SIZE
4424 size used to hold a redundant copy of the environment data, so
4425 that there is a valid backup copy in case there is a power failure
4426 during a "saveenv" operation. CONFIG_ENV_OFFSET_RENDUND must be
4427 aligned to an erase block boundary.
4429 - CONFIG_ENV_RANGE (optional):
4431 Specifies the length of the region in which the environment
4432 can be written. This should be a multiple of the NAND device's
4433 block size. Specifying a range with more erase blocks than
4434 are needed to hold CONFIG_ENV_SIZE allows bad blocks within
4435 the range to be avoided.
4437 - CONFIG_ENV_OFFSET_OOB (optional):
4439 Enables support for dynamically retrieving the offset of the
4440 environment from block zero's out-of-band data. The
4441 "nand env.oob" command can be used to record this offset.
4442 Currently, CONFIG_ENV_OFFSET_REDUND is not supported when
4443 using CONFIG_ENV_OFFSET_OOB.
4445 - CONFIG_NAND_ENV_DST
4447 Defines address in RAM to which the nand_spl code should copy the
4448 environment. If redundant environment is used, it will be copied to
4449 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE.
4451 - CONFIG_ENV_IS_IN_UBI:
4453 Define this if you have an UBI volume that you want to use for the
4454 environment. This has the benefit of wear-leveling the environment
4455 accesses, which is important on NAND.
4457 - CONFIG_ENV_UBI_PART:
4459 Define this to a string that is the mtd partition containing the UBI.
4461 - CONFIG_ENV_UBI_VOLUME:
4463 Define this to the name of the volume that you want to store the
4466 - CONFIG_ENV_UBI_VOLUME_REDUND:
4468 Define this to the name of another volume to store a second copy of
4469 the environment in. This will enable redundant environments in UBI.
4470 It is assumed that both volumes are in the same MTD partition.
4472 - CONFIG_UBI_SILENCE_MSG
4473 - CONFIG_UBIFS_SILENCE_MSG
4475 You will probably want to define these to avoid a really noisy system
4476 when storing the env in UBI.
4478 - CONFIG_ENV_IS_IN_FAT:
4479 Define this if you want to use the FAT file system for the environment.
4481 - FAT_ENV_INTERFACE:
4483 Define this to a string that is the name of the block device.
4485 - FAT_ENV_DEV_AND_PART:
4487 Define this to a string to specify the partition of the device. It can
4490 "D:P", "D:0", "D", "D:" or "D:auto" (D, P are integers. And P >= 1)
4491 - "D:P": device D partition P. Error occurs if device D has no
4494 - "D" or "D:": device D partition 1 if device D has partition
4495 table, or the whole device D if has no partition
4497 - "D:auto": first partition in device D with bootable flag set.
4498 If none, first valid partition in device D. If no
4499 partition table then means device D.
4503 It's a string of the FAT file name. This file use to store the
4507 This should be defined. Otherwise it cannot save the environment file.
4509 - CONFIG_ENV_IS_IN_MMC:
4511 Define this if you have an MMC device which you want to use for the
4514 - CONFIG_SYS_MMC_ENV_DEV:
4516 Specifies which MMC device the environment is stored in.
4518 - CONFIG_SYS_MMC_ENV_PART (optional):
4520 Specifies which MMC partition the environment is stored in. If not
4521 set, defaults to partition 0, the user area. Common values might be
4522 1 (first MMC boot partition), 2 (second MMC boot partition).
4524 - CONFIG_ENV_OFFSET:
4527 These two #defines specify the offset and size of the environment
4528 area within the specified MMC device.
4530 If offset is positive (the usual case), it is treated as relative to
4531 the start of the MMC partition. If offset is negative, it is treated
4532 as relative to the end of the MMC partition. This can be useful if
4533 your board may be fitted with different MMC devices, which have
4534 different sizes for the MMC partitions, and you always want the
4535 environment placed at the very end of the partition, to leave the
4536 maximum possible space before it, to store other data.
4538 These two values are in units of bytes, but must be aligned to an
4539 MMC sector boundary.
4541 - CONFIG_ENV_OFFSET_REDUND (optional):
4543 Specifies a second storage area, of CONFIG_ENV_SIZE size, used to
4544 hold a redundant copy of the environment data. This provides a
4545 valid backup copy in case the other copy is corrupted, e.g. due
4546 to a power failure during a "saveenv" operation.
4548 This value may also be positive or negative; this is handled in the
4549 same way as CONFIG_ENV_OFFSET.
4551 This value is also in units of bytes, but must also be aligned to
4552 an MMC sector boundary.
4554 - CONFIG_ENV_SIZE_REDUND (optional):
4556 This value need not be set, even when CONFIG_ENV_OFFSET_REDUND is
4557 set. If this value is set, it must be set to the same value as
4560 - CONFIG_SYS_SPI_INIT_OFFSET
4562 Defines offset to the initial SPI buffer area in DPRAM. The
4563 area is used at an early stage (ROM part) if the environment
4564 is configured to reside in the SPI EEPROM: We need a 520 byte
4565 scratch DPRAM area. It is used between the two initialization
4566 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems
4567 to be a good choice since it makes it far enough from the
4568 start of the data area as well as from the stack pointer.
4570 Please note that the environment is read-only until the monitor
4571 has been relocated to RAM and a RAM copy of the environment has been
4572 created; also, when using EEPROM you will have to use getenv_f()
4573 until then to read environment variables.
4575 The environment is protected by a CRC32 checksum. Before the monitor
4576 is relocated into RAM, as a result of a bad CRC you will be working
4577 with the compiled-in default environment - *silently*!!! [This is
4578 necessary, because the first environment variable we need is the
4579 "baudrate" setting for the console - if we have a bad CRC, we don't
4580 have any device yet where we could complain.]
4582 Note: once the monitor has been relocated, then it will complain if
4583 the default environment is used; a new CRC is computed as soon as you
4584 use the "saveenv" command to store a valid environment.
4586 - CONFIG_SYS_FAULT_ECHO_LINK_DOWN:
4587 Echo the inverted Ethernet link state to the fault LED.
4589 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR
4590 also needs to be defined.
4592 - CONFIG_SYS_FAULT_MII_ADDR:
4593 MII address of the PHY to check for the Ethernet link state.
4595 - CONFIG_NS16550_MIN_FUNCTIONS:
4596 Define this if you desire to only have use of the NS16550_init
4597 and NS16550_putc functions for the serial driver located at
4598 drivers/serial/ns16550.c. This option is useful for saving
4599 space for already greatly restricted images, including but not
4600 limited to NAND_SPL configurations.
4602 - CONFIG_DISPLAY_BOARDINFO
4603 Display information about the board that U-Boot is running on
4604 when U-Boot starts up. The board function checkboard() is called
4607 - CONFIG_DISPLAY_BOARDINFO_LATE
4608 Similar to the previous option, but display this information
4609 later, once stdio is running and output goes to the LCD, if
4612 - CONFIG_BOARD_SIZE_LIMIT:
4613 Maximum size of the U-Boot image. When defined, the
4614 build system checks that the actual size does not
4617 Low Level (hardware related) configuration options:
4618 ---------------------------------------------------
4620 - CONFIG_SYS_CACHELINE_SIZE:
4621 Cache Line Size of the CPU.
4623 - CONFIG_SYS_DEFAULT_IMMR:
4624 Default address of the IMMR after system reset.
4626 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU,
4627 and RPXsuper) to be able to adjust the position of
4628 the IMMR register after a reset.
4630 - CONFIG_SYS_CCSRBAR_DEFAULT:
4631 Default (power-on reset) physical address of CCSR on Freescale
4634 - CONFIG_SYS_CCSRBAR:
4635 Virtual address of CCSR. On a 32-bit build, this is typically
4636 the same value as CONFIG_SYS_CCSRBAR_DEFAULT.
4638 CONFIG_SYS_DEFAULT_IMMR must also be set to this value,
4639 for cross-platform code that uses that macro instead.
4641 - CONFIG_SYS_CCSRBAR_PHYS:
4642 Physical address of CCSR. CCSR can be relocated to a new
4643 physical address, if desired. In this case, this macro should
4644 be set to that address. Otherwise, it should be set to the
4645 same value as CONFIG_SYS_CCSRBAR_DEFAULT. For example, CCSR
4646 is typically relocated on 36-bit builds. It is recommended
4647 that this macro be defined via the _HIGH and _LOW macros:
4649 #define CONFIG_SYS_CCSRBAR_PHYS ((CONFIG_SYS_CCSRBAR_PHYS_HIGH
4650 * 1ull) << 32 | CONFIG_SYS_CCSRBAR_PHYS_LOW)
4652 - CONFIG_SYS_CCSRBAR_PHYS_HIGH:
4653 Bits 33-36 of CONFIG_SYS_CCSRBAR_PHYS. This value is typically
4654 either 0 (32-bit build) or 0xF (36-bit build). This macro is
4655 used in assembly code, so it must not contain typecasts or
4656 integer size suffixes (e.g. "ULL").
4658 - CONFIG_SYS_CCSRBAR_PHYS_LOW:
4659 Lower 32-bits of CONFIG_SYS_CCSRBAR_PHYS. This macro is
4660 used in assembly code, so it must not contain typecasts or
4661 integer size suffixes (e.g. "ULL").
4663 - CONFIG_SYS_CCSR_DO_NOT_RELOCATE:
4664 If this macro is defined, then CONFIG_SYS_CCSRBAR_PHYS will be
4665 forced to a value that ensures that CCSR is not relocated.
4667 - Floppy Disk Support:
4668 CONFIG_SYS_FDC_DRIVE_NUMBER
4670 the default drive number (default value 0)
4672 CONFIG_SYS_ISA_IO_STRIDE
4674 defines the spacing between FDC chipset registers
4677 CONFIG_SYS_ISA_IO_OFFSET
4679 defines the offset of register from address. It
4680 depends on which part of the data bus is connected to
4681 the FDC chipset. (default value 0)
4683 If CONFIG_SYS_ISA_IO_STRIDE CONFIG_SYS_ISA_IO_OFFSET and
4684 CONFIG_SYS_FDC_DRIVE_NUMBER are undefined, they take their
4687 if CONFIG_SYS_FDC_HW_INIT is defined, then the function
4688 fdc_hw_init() is called at the beginning of the FDC
4689 setup. fdc_hw_init() must be provided by the board
4690 source code. It is used to make hardware-dependent
4694 Most IDE controllers were designed to be connected with PCI
4695 interface. Only few of them were designed for AHB interface.
4696 When software is doing ATA command and data transfer to
4697 IDE devices through IDE-AHB controller, some additional
4698 registers accessing to these kind of IDE-AHB controller
4701 - CONFIG_SYS_IMMR: Physical address of the Internal Memory.
4702 DO NOT CHANGE unless you know exactly what you're
4703 doing! (11-4) [MPC8xx/82xx systems only]
4705 - CONFIG_SYS_INIT_RAM_ADDR:
4707 Start address of memory area that can be used for
4708 initial data and stack; please note that this must be
4709 writable memory that is working WITHOUT special
4710 initialization, i. e. you CANNOT use normal RAM which
4711 will become available only after programming the
4712 memory controller and running certain initialization
4715 U-Boot uses the following memory types:
4716 - MPC8xx and MPC8260: IMMR (internal memory of the CPU)
4717 - MPC824X: data cache
4718 - PPC4xx: data cache
4720 - CONFIG_SYS_GBL_DATA_OFFSET:
4722 Offset of the initial data structure in the memory
4723 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually
4724 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial
4725 data is located at the end of the available space
4726 (sometimes written as (CONFIG_SYS_INIT_RAM_SIZE -
4727 CONFIG_SYS_INIT_DATA_SIZE), and the initial stack is just
4728 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR +
4729 CONFIG_SYS_GBL_DATA_OFFSET) downward.
4732 On the MPC824X (or other systems that use the data
4733 cache for initial memory) the address chosen for
4734 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must
4735 point to an otherwise UNUSED address space between
4736 the top of RAM and the start of the PCI space.
4738 - CONFIG_SYS_SIUMCR: SIU Module Configuration (11-6)
4740 - CONFIG_SYS_SYPCR: System Protection Control (11-9)
4742 - CONFIG_SYS_TBSCR: Time Base Status and Control (11-26)
4744 - CONFIG_SYS_PISCR: Periodic Interrupt Status and Control (11-31)
4746 - CONFIG_SYS_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30)
4748 - CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27)
4750 - CONFIG_SYS_OR_TIMING_SDRAM:
4753 - CONFIG_SYS_MAMR_PTA:
4754 periodic timer for refresh
4756 - CONFIG_SYS_DER: Debug Event Register (37-47)
4758 - FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM,
4759 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP,
4760 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM,
4761 CONFIG_SYS_BR1_PRELIM:
4762 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
4764 - SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
4765 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM,
4766 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM:
4767 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
4769 - CONFIG_SYS_MAMR_PTA, CONFIG_SYS_MPTPR_2BK_4K, CONFIG_SYS_MPTPR_1BK_4K, CONFIG_SYS_MPTPR_2BK_8K,
4770 CONFIG_SYS_MPTPR_1BK_8K, CONFIG_SYS_MAMR_8COL, CONFIG_SYS_MAMR_9COL:
4771 Machine Mode Register and Memory Periodic Timer
4772 Prescaler definitions (SDRAM timing)
4774 - CONFIG_SYS_I2C_UCODE_PATCH, CONFIG_SYS_I2C_DPMEM_OFFSET [0x1FC0]:
4775 enable I2C microcode relocation patch (MPC8xx);
4776 define relocation offset in DPRAM [DSP2]
4778 - CONFIG_SYS_SMC_UCODE_PATCH, CONFIG_SYS_SMC_DPMEM_OFFSET [0x1FC0]:
4779 enable SMC microcode relocation patch (MPC8xx);
4780 define relocation offset in DPRAM [SMC1]
4782 - CONFIG_SYS_SPI_UCODE_PATCH, CONFIG_SYS_SPI_DPMEM_OFFSET [0x1FC0]:
4783 enable SPI microcode relocation patch (MPC8xx);
4784 define relocation offset in DPRAM [SCC4]
4786 - CONFIG_SYS_USE_OSCCLK:
4787 Use OSCM clock mode on MBX8xx board. Be careful,
4788 wrong setting might damage your board. Read
4789 doc/README.MBX before setting this variable!
4791 - CONFIG_SYS_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only)
4792 Offset of the bootmode word in DPRAM used by post
4793 (Power On Self Tests). This definition overrides
4794 #define'd default value in commproc.h resp.
4797 - CONFIG_SYS_PCI_SLV_MEM_LOCAL, CONFIG_SYS_PCI_SLV_MEM_BUS, CONFIG_SYS_PICMR0_MASK_ATTRIB,
4798 CONFIG_SYS_PCI_MSTR0_LOCAL, CONFIG_SYS_PCIMSK0_MASK, CONFIG_SYS_PCI_MSTR1_LOCAL,
4799 CONFIG_SYS_PCIMSK1_MASK, CONFIG_SYS_PCI_MSTR_MEM_LOCAL, CONFIG_SYS_PCI_MSTR_MEM_BUS,
4800 CONFIG_SYS_CPU_PCI_MEM_START, CONFIG_SYS_PCI_MSTR_MEM_SIZE, CONFIG_SYS_POCMR0_MASK_ATTRIB,
4801 CONFIG_SYS_PCI_MSTR_MEMIO_LOCAL, CONFIG_SYS_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START,
4802 CONFIG_SYS_PCI_MSTR_MEMIO_SIZE, CONFIG_SYS_POCMR1_MASK_ATTRIB, CONFIG_SYS_PCI_MSTR_IO_LOCAL,
4803 CONFIG_SYS_PCI_MSTR_IO_BUS, CONFIG_SYS_CPU_PCI_IO_START, CONFIG_SYS_PCI_MSTR_IO_SIZE,
4804 CONFIG_SYS_POCMR2_MASK_ATTRIB: (MPC826x only)
4805 Overrides the default PCI memory map in arch/powerpc/cpu/mpc8260/pci.c if set.
4807 - CONFIG_PCI_DISABLE_PCIE:
4808 Disable PCI-Express on systems where it is supported but not
4811 - CONFIG_PCI_ENUM_ONLY
4812 Only scan through and get the devices on the buses.
4813 Don't do any setup work, presumably because someone or
4814 something has already done it, and we don't need to do it
4815 a second time. Useful for platforms that are pre-booted
4816 by coreboot or similar.
4818 - CONFIG_PCI_INDIRECT_BRIDGE:
4819 Enable support for indirect PCI bridges.
4822 Chip has SRIO or not
4825 Board has SRIO 1 port available
4828 Board has SRIO 2 port available
4830 - CONFIG_SRIO_PCIE_BOOT_MASTER
4831 Board can support master function for Boot from SRIO and PCIE
4833 - CONFIG_SYS_SRIOn_MEM_VIRT:
4834 Virtual Address of SRIO port 'n' memory region
4836 - CONFIG_SYS_SRIOn_MEM_PHYS:
4837 Physical Address of SRIO port 'n' memory region
4839 - CONFIG_SYS_SRIOn_MEM_SIZE:
4840 Size of SRIO port 'n' memory region
4842 - CONFIG_SYS_NAND_BUSWIDTH_16BIT
4843 Defined to tell the NAND controller that the NAND chip is using
4845 Not all NAND drivers use this symbol.
4846 Example of drivers that use it:
4847 - drivers/mtd/nand/ndfc.c
4848 - drivers/mtd/nand/mxc_nand.c
4850 - CONFIG_SYS_NDFC_EBC0_CFG
4851 Sets the EBC0_CFG register for the NDFC. If not defined
4852 a default value will be used.
4855 Get DDR timing information from an I2C EEPROM. Common
4856 with pluggable memory modules such as SODIMMs
4859 I2C address of the SPD EEPROM
4861 - CONFIG_SYS_SPD_BUS_NUM
4862 If SPD EEPROM is on an I2C bus other than the first
4863 one, specify here. Note that the value must resolve
4864 to something your driver can deal with.
4866 - CONFIG_SYS_DDR_RAW_TIMING
4867 Get DDR timing information from other than SPD. Common with
4868 soldered DDR chips onboard without SPD. DDR raw timing
4869 parameters are extracted from datasheet and hard-coded into
4870 header files or board specific files.
4872 - CONFIG_FSL_DDR_INTERACTIVE
4873 Enable interactive DDR debugging. See doc/README.fsl-ddr.
4875 - CONFIG_FSL_DDR_SYNC_REFRESH
4876 Enable sync of refresh for multiple controllers.
4878 - CONFIG_FSL_DDR_BIST
4879 Enable built-in memory test for Freescale DDR controllers.
4881 - CONFIG_SYS_83XX_DDR_USES_CS0
4882 Only for 83xx systems. If specified, then DDR should
4883 be configured using CS0 and CS1 instead of CS2 and CS3.
4885 - CONFIG_ETHER_ON_FEC[12]
4886 Define to enable FEC[12] on a 8xx series processor.
4888 - CONFIG_FEC[12]_PHY
4889 Define to the hardcoded PHY address which corresponds
4890 to the given FEC; i. e.
4891 #define CONFIG_FEC1_PHY 4
4892 means that the PHY with address 4 is connected to FEC1
4894 When set to -1, means to probe for first available.
4896 - CONFIG_FEC[12]_PHY_NORXERR
4897 The PHY does not have a RXERR line (RMII only).
4898 (so program the FEC to ignore it).
4901 Enable RMII mode for all FECs.
4902 Note that this is a global option, we can't
4903 have one FEC in standard MII mode and another in RMII mode.
4905 - CONFIG_CRC32_VERIFY
4906 Add a verify option to the crc32 command.
4909 => crc32 -v <address> <count> <crc32>
4911 Where address/count indicate a memory area
4912 and crc32 is the correct crc32 which the
4916 Add the "loopw" memory command. This only takes effect if
4917 the memory commands are activated globally (CONFIG_CMD_MEM).
4920 Add the "mdc" and "mwc" memory commands. These are cyclic
4925 This command will print 4 bytes (10,11,12,13) each 500 ms.
4927 => mwc.l 100 12345678 10
4928 This command will write 12345678 to address 100 all 10 ms.
4930 This only takes effect if the memory commands are activated
4931 globally (CONFIG_CMD_MEM).
4933 - CONFIG_SKIP_LOWLEVEL_INIT
4934 [ARM, NDS32, MIPS only] If this variable is defined, then certain
4935 low level initializations (like setting up the memory
4936 controller) are omitted and/or U-Boot does not
4937 relocate itself into RAM.
4939 Normally this variable MUST NOT be defined. The only
4940 exception is when U-Boot is loaded (to RAM) by some
4941 other boot loader or by a debugger which performs
4942 these initializations itself.
4945 Modifies the behaviour of start.S when compiling a loader
4946 that is executed before the actual U-Boot. E.g. when
4947 compiling a NAND SPL.
4950 Modifies the behaviour of start.S when compiling a loader
4951 that is executed after the SPL and before the actual U-Boot.
4952 It is loaded by the SPL.
4954 - CONFIG_SYS_MPC85XX_NO_RESETVEC
4955 Only for 85xx systems. If this variable is specified, the section
4956 .resetvec is not kept and the section .bootpg is placed in the
4957 previous 4k of the .text section.
4959 - CONFIG_ARCH_MAP_SYSMEM
4960 Generally U-Boot (and in particular the md command) uses
4961 effective address. It is therefore not necessary to regard
4962 U-Boot address as virtual addresses that need to be translated
4963 to physical addresses. However, sandbox requires this, since
4964 it maintains its own little RAM buffer which contains all
4965 addressable memory. This option causes some memory accesses
4966 to be mapped through map_sysmem() / unmap_sysmem().
4968 - CONFIG_USE_ARCH_MEMCPY
4969 CONFIG_USE_ARCH_MEMSET
4970 If these options are used a optimized version of memcpy/memset will
4971 be used if available. These functions may be faster under some
4972 conditions but may increase the binary size.
4974 - CONFIG_X86_RESET_VECTOR
4975 If defined, the x86 reset vector code is included. This is not
4976 needed when U-Boot is running from Coreboot.
4979 Defines the MPU clock speed (in MHz).
4981 NOTE : currently only supported on AM335x platforms.
4983 - CONFIG_SPL_AM33XX_ENABLE_RTC32K_OSC:
4984 Enables the RTC32K OSC on AM33xx based plattforms
4986 - CONFIG_SYS_NAND_NO_SUBPAGE_WRITE
4987 Option to disable subpage write in NAND driver
4988 driver that uses this:
4989 drivers/mtd/nand/davinci_nand.c
4991 Freescale QE/FMAN Firmware Support:
4992 -----------------------------------
4994 The Freescale QUICCEngine (QE) and Frame Manager (FMAN) both support the
4995 loading of "firmware", which is encoded in the QE firmware binary format.
4996 This firmware often needs to be loaded during U-Boot booting, so macros
4997 are used to identify the storage device (NOR flash, SPI, etc) and the address
5000 - CONFIG_SYS_FMAN_FW_ADDR
5001 The address in the storage device where the FMAN microcode is located. The
5002 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
5005 - CONFIG_SYS_QE_FW_ADDR
5006 The address in the storage device where the QE microcode is located. The
5007 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
5010 - CONFIG_SYS_QE_FMAN_FW_LENGTH
5011 The maximum possible size of the firmware. The firmware binary format
5012 has a field that specifies the actual size of the firmware, but it
5013 might not be possible to read any part of the firmware unless some
5014 local storage is allocated to hold the entire firmware first.
5016 - CONFIG_SYS_QE_FMAN_FW_IN_NOR
5017 Specifies that QE/FMAN firmware is located in NOR flash, mapped as
5018 normal addressable memory via the LBC. CONFIG_SYS_FMAN_FW_ADDR is the
5019 virtual address in NOR flash.
5021 - CONFIG_SYS_QE_FMAN_FW_IN_NAND
5022 Specifies that QE/FMAN firmware is located in NAND flash.
5023 CONFIG_SYS_FMAN_FW_ADDR is the offset within NAND flash.
5025 - CONFIG_SYS_QE_FMAN_FW_IN_MMC
5026 Specifies that QE/FMAN firmware is located on the primary SD/MMC
5027 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
5029 - CONFIG_SYS_QE_FMAN_FW_IN_SPIFLASH
5030 Specifies that QE/FMAN firmware is located on the primary SPI
5031 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
5033 - CONFIG_SYS_QE_FMAN_FW_IN_REMOTE
5034 Specifies that QE/FMAN firmware is located in the remote (master)
5035 memory space. CONFIG_SYS_FMAN_FW_ADDR is a virtual address which
5036 can be mapped from slave TLB->slave LAW->slave SRIO or PCIE outbound
5037 window->master inbound window->master LAW->the ucode address in
5038 master's memory space.
5040 Freescale Layerscape Management Complex Firmware Support:
5041 ---------------------------------------------------------
5042 The Freescale Layerscape Management Complex (MC) supports the loading of
5044 This firmware often needs to be loaded during U-Boot booting, so macros
5045 are used to identify the storage device (NOR flash, SPI, etc) and the address
5048 - CONFIG_FSL_MC_ENET
5049 Enable the MC driver for Layerscape SoCs.
5051 - CONFIG_SYS_LS_MC_FW_ADDR
5052 The address in the storage device where the firmware is located. The
5053 meaning of this address depends on which CONFIG_SYS_LS_MC_FW_IN_xxx macro
5056 - CONFIG_SYS_LS_MC_FW_LENGTH
5057 The maximum possible size of the firmware. The firmware binary format
5058 has a field that specifies the actual size of the firmware, but it
5059 might not be possible to read any part of the firmware unless some
5060 local storage is allocated to hold the entire firmware first.
5062 - CONFIG_SYS_LS_MC_FW_IN_NOR
5063 Specifies that MC firmware is located in NOR flash, mapped as
5064 normal addressable memory via the LBC. CONFIG_SYS_LS_MC_FW_ADDR is the
5065 virtual address in NOR flash.
5067 Freescale Layerscape Debug Server Support:
5068 -------------------------------------------
5069 The Freescale Layerscape Debug Server Support supports the loading of
5070 "Debug Server firmware" and triggering SP boot-rom.
5071 This firmware often needs to be loaded during U-Boot booting.
5073 - CONFIG_FSL_DEBUG_SERVER
5074 Enable the Debug Server for Layerscape SoCs.
5076 - CONFIG_SYS_DEBUG_SERVER_DRAM_BLOCK_MIN_SIZE
5077 Define minimum DDR size required for debug server image
5079 - CONFIG_SYS_MEM_TOP_HIDE_MIN
5080 Define minimum DDR size to be hided from top of the DDR memory
5085 In order to achieve reproducible builds, timestamps used in the U-Boot build
5086 process have to be set to a fixed value.
5088 This is done using the SOURCE_DATE_EPOCH environment variable.
5089 SOURCE_DATE_EPOCH is to be set on the build host's shell, not as a configuration
5090 option for U-Boot or an environment variable in U-Boot.
5092 SOURCE_DATE_EPOCH should be set to a number of seconds since the epoch, in UTC.
5094 Building the Software:
5095 ======================
5097 Building U-Boot has been tested in several native build environments
5098 and in many different cross environments. Of course we cannot support
5099 all possibly existing versions of cross development tools in all
5100 (potentially obsolete) versions. In case of tool chain problems we
5101 recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK)
5102 which is extensively used to build and test U-Boot.
5104 If you are not using a native environment, it is assumed that you
5105 have GNU cross compiling tools available in your path. In this case,
5106 you must set the environment variable CROSS_COMPILE in your shell.
5107 Note that no changes to the Makefile or any other source files are
5108 necessary. For example using the ELDK on a 4xx CPU, please enter:
5110 $ CROSS_COMPILE=ppc_4xx-
5111 $ export CROSS_COMPILE
5113 Note: If you wish to generate Windows versions of the utilities in
5114 the tools directory you can use the MinGW toolchain
5115 (http://www.mingw.org). Set your HOST tools to the MinGW
5116 toolchain and execute 'make tools'. For example:
5118 $ make HOSTCC=i586-mingw32msvc-gcc HOSTSTRIP=i586-mingw32msvc-strip tools
5120 Binaries such as tools/mkimage.exe will be created which can
5121 be executed on computers running Windows.
5123 U-Boot is intended to be simple to build. After installing the
5124 sources you must configure U-Boot for one specific board type. This
5129 where "NAME_defconfig" is the name of one of the existing configu-
5130 rations; see boards.cfg for supported names.
5132 Note: for some board special configuration names may exist; check if
5133 additional information is available from the board vendor; for
5134 instance, the TQM823L systems are available without (standard)
5135 or with LCD support. You can select such additional "features"
5136 when choosing the configuration, i. e.
5138 make TQM823L_defconfig
5139 - will configure for a plain TQM823L, i. e. no LCD support
5141 make TQM823L_LCD_defconfig
5142 - will configure for a TQM823L with U-Boot console on LCD
5147 Finally, type "make all", and you should get some working U-Boot
5148 images ready for download to / installation on your system:
5150 - "u-boot.bin" is a raw binary image
5151 - "u-boot" is an image in ELF binary format
5152 - "u-boot.srec" is in Motorola S-Record format
5154 By default the build is performed locally and the objects are saved
5155 in the source directory. One of the two methods can be used to change
5156 this behavior and build U-Boot to some external directory:
5158 1. Add O= to the make command line invocations:
5160 make O=/tmp/build distclean
5161 make O=/tmp/build NAME_defconfig
5162 make O=/tmp/build all
5164 2. Set environment variable KBUILD_OUTPUT to point to the desired location:
5166 export KBUILD_OUTPUT=/tmp/build
5171 Note that the command line "O=" setting overrides the KBUILD_OUTPUT environment
5175 Please be aware that the Makefiles assume you are using GNU make, so
5176 for instance on NetBSD you might need to use "gmake" instead of
5180 If the system board that you have is not listed, then you will need
5181 to port U-Boot to your hardware platform. To do this, follow these
5184 1. Add a new configuration option for your board to the toplevel
5185 "boards.cfg" file, using the existing entries as examples.
5186 Follow the instructions there to keep the boards in order.
5187 2. Create a new directory to hold your board specific code. Add any
5188 files you need. In your board directory, you will need at least
5189 the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds".
5190 3. Create a new configuration file "include/configs/<board>.h" for
5192 3. If you're porting U-Boot to a new CPU, then also create a new
5193 directory to hold your CPU specific code. Add any files you need.
5194 4. Run "make <board>_defconfig" with your new name.
5195 5. Type "make", and you should get a working "u-boot.srec" file
5196 to be installed on your target system.
5197 6. Debug and solve any problems that might arise.
5198 [Of course, this last step is much harder than it sounds.]
5201 Testing of U-Boot Modifications, Ports to New Hardware, etc.:
5202 ==============================================================
5204 If you have modified U-Boot sources (for instance added a new board
5205 or support for new devices, a new CPU, etc.) you are expected to
5206 provide feedback to the other developers. The feedback normally takes
5207 the form of a "patch", i. e. a context diff against a certain (latest
5208 official or latest in the git repository) version of U-Boot sources.
5210 But before you submit such a patch, please verify that your modifi-
5211 cation did not break existing code. At least make sure that *ALL* of
5212 the supported boards compile WITHOUT ANY compiler warnings. To do so,
5213 just run the "MAKEALL" script, which will configure and build U-Boot
5214 for ALL supported system. Be warned, this will take a while. You can
5215 select which (cross) compiler to use by passing a `CROSS_COMPILE'
5216 environment variable to the script, i. e. to use the ELDK cross tools
5219 CROSS_COMPILE=ppc_8xx- MAKEALL
5221 or to build on a native PowerPC system you can type
5223 CROSS_COMPILE=' ' MAKEALL
5225 When using the MAKEALL script, the default behaviour is to build
5226 U-Boot in the source directory. This location can be changed by
5227 setting the BUILD_DIR environment variable. Also, for each target
5228 built, the MAKEALL script saves two log files (<target>.ERR and
5229 <target>.MAKEALL) in the <source dir>/LOG directory. This default
5230 location can be changed by setting the MAKEALL_LOGDIR environment
5231 variable. For example:
5233 export BUILD_DIR=/tmp/build
5234 export MAKEALL_LOGDIR=/tmp/log
5235 CROSS_COMPILE=ppc_8xx- MAKEALL
5237 With the above settings build objects are saved in the /tmp/build,
5238 log files are saved in the /tmp/log and the source tree remains clean
5239 during the whole build process.
5242 See also "U-Boot Porting Guide" below.
5245 Monitor Commands - Overview:
5246 ============================
5248 go - start application at address 'addr'
5249 run - run commands in an environment variable
5250 bootm - boot application image from memory
5251 bootp - boot image via network using BootP/TFTP protocol
5252 bootz - boot zImage from memory
5253 tftpboot- boot image via network using TFTP protocol
5254 and env variables "ipaddr" and "serverip"
5255 (and eventually "gatewayip")
5256 tftpput - upload a file via network using TFTP protocol
5257 rarpboot- boot image via network using RARP/TFTP protocol
5258 diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
5259 loads - load S-Record file over serial line
5260 loadb - load binary file over serial line (kermit mode)
5262 mm - memory modify (auto-incrementing)
5263 nm - memory modify (constant address)
5264 mw - memory write (fill)
5266 cmp - memory compare
5267 crc32 - checksum calculation
5268 i2c - I2C sub-system
5269 sspi - SPI utility commands
5270 base - print or set address offset
5271 printenv- print environment variables
5272 setenv - set environment variables
5273 saveenv - save environment variables to persistent storage
5274 protect - enable or disable FLASH write protection
5275 erase - erase FLASH memory
5276 flinfo - print FLASH memory information
5277 nand - NAND memory operations (see doc/README.nand)
5278 bdinfo - print Board Info structure
5279 iminfo - print header information for application image
5280 coninfo - print console devices and informations
5281 ide - IDE sub-system
5282 loop - infinite loop on address range
5283 loopw - infinite write loop on address range
5284 mtest - simple RAM test
5285 icache - enable or disable instruction cache
5286 dcache - enable or disable data cache
5287 reset - Perform RESET of the CPU
5288 echo - echo args to console
5289 version - print monitor version
5290 help - print online help
5291 ? - alias for 'help'
5294 Monitor Commands - Detailed Description:
5295 ========================================
5299 For now: just type "help <command>".
5302 Environment Variables:
5303 ======================
5305 U-Boot supports user configuration using Environment Variables which
5306 can be made persistent by saving to Flash memory.
5308 Environment Variables are set using "setenv", printed using
5309 "printenv", and saved to Flash using "saveenv". Using "setenv"
5310 without a value can be used to delete a variable from the
5311 environment. As long as you don't save the environment you are
5312 working with an in-memory copy. In case the Flash area containing the
5313 environment is erased by accident, a default environment is provided.
5315 Some configuration options can be set using Environment Variables.
5317 List of environment variables (most likely not complete):
5319 baudrate - see CONFIG_BAUDRATE
5321 bootdelay - see CONFIG_BOOTDELAY
5323 bootcmd - see CONFIG_BOOTCOMMAND
5325 bootargs - Boot arguments when booting an RTOS image
5327 bootfile - Name of the image to load with TFTP
5329 bootm_low - Memory range available for image processing in the bootm
5330 command can be restricted. This variable is given as
5331 a hexadecimal number and defines lowest address allowed
5332 for use by the bootm command. See also "bootm_size"
5333 environment variable. Address defined by "bootm_low" is
5334 also the base of the initial memory mapping for the Linux
5335 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ and
5338 bootm_mapsize - Size of the initial memory mapping for the Linux kernel.
5339 This variable is given as a hexadecimal number and it
5340 defines the size of the memory region starting at base
5341 address bootm_low that is accessible by the Linux kernel
5342 during early boot. If unset, CONFIG_SYS_BOOTMAPSZ is used
5343 as the default value if it is defined, and bootm_size is
5346 bootm_size - Memory range available for image processing in the bootm
5347 command can be restricted. This variable is given as
5348 a hexadecimal number and defines the size of the region
5349 allowed for use by the bootm command. See also "bootm_low"
5350 environment variable.
5352 updatefile - Location of the software update file on a TFTP server, used
5353 by the automatic software update feature. Please refer to
5354 documentation in doc/README.update for more details.
5356 autoload - if set to "no" (any string beginning with 'n'),
5357 "bootp" will just load perform a lookup of the
5358 configuration from the BOOTP server, but not try to
5359 load any image using TFTP
5361 autostart - if set to "yes", an image loaded using the "bootp",
5362 "rarpboot", "tftpboot" or "diskboot" commands will
5363 be automatically started (by internally calling
5366 If set to "no", a standalone image passed to the
5367 "bootm" command will be copied to the load address
5368 (and eventually uncompressed), but NOT be started.
5369 This can be used to load and uncompress arbitrary
5372 fdt_high - if set this restricts the maximum address that the
5373 flattened device tree will be copied into upon boot.
5374 For example, if you have a system with 1 GB memory
5375 at physical address 0x10000000, while Linux kernel
5376 only recognizes the first 704 MB as low memory, you
5377 may need to set fdt_high as 0x3C000000 to have the
5378 device tree blob be copied to the maximum address
5379 of the 704 MB low memory, so that Linux kernel can
5380 access it during the boot procedure.
5382 If this is set to the special value 0xFFFFFFFF then
5383 the fdt will not be copied at all on boot. For this
5384 to work it must reside in writable memory, have
5385 sufficient padding on the end of it for u-boot to
5386 add the information it needs into it, and the memory
5387 must be accessible by the kernel.
5389 fdtcontroladdr- if set this is the address of the control flattened
5390 device tree used by U-Boot when CONFIG_OF_CONTROL is
5393 i2cfast - (PPC405GP|PPC405EP only)
5394 if set to 'y' configures Linux I2C driver for fast
5395 mode (400kHZ). This environment variable is used in
5396 initialization code. So, for changes to be effective
5397 it must be saved and board must be reset.
5399 initrd_high - restrict positioning of initrd images:
5400 If this variable is not set, initrd images will be
5401 copied to the highest possible address in RAM; this
5402 is usually what you want since it allows for
5403 maximum initrd size. If for some reason you want to
5404 make sure that the initrd image is loaded below the
5405 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment
5406 variable to a value of "no" or "off" or "0".
5407 Alternatively, you can set it to a maximum upper
5408 address to use (U-Boot will still check that it
5409 does not overwrite the U-Boot stack and data).
5411 For instance, when you have a system with 16 MB
5412 RAM, and want to reserve 4 MB from use by Linux,
5413 you can do this by adding "mem=12M" to the value of
5414 the "bootargs" variable. However, now you must make
5415 sure that the initrd image is placed in the first
5416 12 MB as well - this can be done with
5418 setenv initrd_high 00c00000
5420 If you set initrd_high to 0xFFFFFFFF, this is an
5421 indication to U-Boot that all addresses are legal
5422 for the Linux kernel, including addresses in flash
5423 memory. In this case U-Boot will NOT COPY the
5424 ramdisk at all. This may be useful to reduce the
5425 boot time on your system, but requires that this
5426 feature is supported by your Linux kernel.
5428 ipaddr - IP address; needed for tftpboot command
5430 loadaddr - Default load address for commands like "bootp",
5431 "rarpboot", "tftpboot", "loadb" or "diskboot"
5433 loads_echo - see CONFIG_LOADS_ECHO
5435 serverip - TFTP server IP address; needed for tftpboot command
5437 bootretry - see CONFIG_BOOT_RETRY_TIME
5439 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
5441 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
5443 ethprime - controls which interface is used first.
5445 ethact - controls which interface is currently active.
5446 For example you can do the following
5448 => setenv ethact FEC
5449 => ping 192.168.0.1 # traffic sent on FEC
5450 => setenv ethact SCC
5451 => ping 10.0.0.1 # traffic sent on SCC
5453 ethrotate - When set to "no" U-Boot does not go through all
5454 available network interfaces.
5455 It just stays at the currently selected interface.
5457 netretry - When set to "no" each network operation will
5458 either succeed or fail without retrying.
5459 When set to "once" the network operation will
5460 fail when all the available network interfaces
5461 are tried once without success.
5462 Useful on scripts which control the retry operation
5465 npe_ucode - set load address for the NPE microcode
5467 silent_linux - If set then Linux will be told to boot silently, by
5468 changing the console to be empty. If "yes" it will be
5469 made silent. If "no" it will not be made silent. If
5470 unset, then it will be made silent if the U-Boot console
5473 tftpsrcport - If this is set, the value is used for TFTP's
5476 tftpdstport - If this is set, the value is used for TFTP's UDP
5477 destination port instead of the Well Know Port 69.
5479 tftpblocksize - Block size to use for TFTP transfers; if not set,
5480 we use the TFTP server's default block size
5482 tftptimeout - Retransmission timeout for TFTP packets (in milli-
5483 seconds, minimum value is 1000 = 1 second). Defines
5484 when a packet is considered to be lost so it has to
5485 be retransmitted. The default is 5000 = 5 seconds.
5486 Lowering this value may make downloads succeed
5487 faster in networks with high packet loss rates or
5488 with unreliable TFTP servers.
5490 vlan - When set to a value < 4095 the traffic over
5491 Ethernet is encapsulated/received over 802.1q
5494 The following image location variables contain the location of images
5495 used in booting. The "Image" column gives the role of the image and is
5496 not an environment variable name. The other columns are environment
5497 variable names. "File Name" gives the name of the file on a TFTP
5498 server, "RAM Address" gives the location in RAM the image will be
5499 loaded to, and "Flash Location" gives the image's address in NOR
5500 flash or offset in NAND flash.
5502 *Note* - these variables don't have to be defined for all boards, some
5503 boards currently use other variables for these purposes, and some
5504 boards use these variables for other purposes.
5506 Image File Name RAM Address Flash Location
5507 ----- --------- ----------- --------------
5508 u-boot u-boot u-boot_addr_r u-boot_addr
5509 Linux kernel bootfile kernel_addr_r kernel_addr
5510 device tree blob fdtfile fdt_addr_r fdt_addr
5511 ramdisk ramdiskfile ramdisk_addr_r ramdisk_addr
5513 The following environment variables may be used and automatically
5514 updated by the network boot commands ("bootp" and "rarpboot"),
5515 depending the information provided by your boot server:
5517 bootfile - see above
5518 dnsip - IP address of your Domain Name Server
5519 dnsip2 - IP address of your secondary Domain Name Server
5520 gatewayip - IP address of the Gateway (Router) to use
5521 hostname - Target hostname
5523 netmask - Subnet Mask
5524 rootpath - Pathname of the root filesystem on the NFS server
5525 serverip - see above
5528 There are two special Environment Variables:
5530 serial# - contains hardware identification information such
5531 as type string and/or serial number
5532 ethaddr - Ethernet address
5534 These variables can be set only once (usually during manufacturing of
5535 the board). U-Boot refuses to delete or overwrite these variables
5536 once they have been set once.
5539 Further special Environment Variables:
5541 ver - Contains the U-Boot version string as printed
5542 with the "version" command. This variable is
5543 readonly (see CONFIG_VERSION_VARIABLE).
5546 Please note that changes to some configuration parameters may take
5547 only effect after the next boot (yes, that's just like Windoze :-).
5550 Callback functions for environment variables:
5551 ---------------------------------------------
5553 For some environment variables, the behavior of u-boot needs to change
5554 when their values are changed. This functionality allows functions to
5555 be associated with arbitrary variables. On creation, overwrite, or
5556 deletion, the callback will provide the opportunity for some side
5557 effect to happen or for the change to be rejected.
5559 The callbacks are named and associated with a function using the
5560 U_BOOT_ENV_CALLBACK macro in your board or driver code.
5562 These callbacks are associated with variables in one of two ways. The
5563 static list can be added to by defining CONFIG_ENV_CALLBACK_LIST_STATIC
5564 in the board configuration to a string that defines a list of
5565 associations. The list must be in the following format:
5567 entry = variable_name[:callback_name]
5570 If the callback name is not specified, then the callback is deleted.
5571 Spaces are also allowed anywhere in the list.
5573 Callbacks can also be associated by defining the ".callbacks" variable
5574 with the same list format above. Any association in ".callbacks" will
5575 override any association in the static list. You can define
5576 CONFIG_ENV_CALLBACK_LIST_DEFAULT to a list (string) to define the
5577 ".callbacks" environment variable in the default or embedded environment.
5579 If CONFIG_REGEX is defined, the variable_name above is evaluated as a
5580 regular expression. This allows multiple variables to be connected to
5581 the same callback without explicitly listing them all out.
5584 Command Line Parsing:
5585 =====================
5587 There are two different command line parsers available with U-Boot:
5588 the old "simple" one, and the much more powerful "hush" shell:
5590 Old, simple command line parser:
5591 --------------------------------
5593 - supports environment variables (through setenv / saveenv commands)
5594 - several commands on one line, separated by ';'
5595 - variable substitution using "... ${name} ..." syntax
5596 - special characters ('$', ';') can be escaped by prefixing with '\',
5598 setenv bootcmd bootm \${address}
5599 - You can also escape text by enclosing in single apostrophes, for example:
5600 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
5605 - similar to Bourne shell, with control structures like
5606 if...then...else...fi, for...do...done; while...do...done,
5607 until...do...done, ...
5608 - supports environment ("global") variables (through setenv / saveenv
5609 commands) and local shell variables (through standard shell syntax
5610 "name=value"); only environment variables can be used with "run"
5616 (1) If a command line (or an environment variable executed by a "run"
5617 command) contains several commands separated by semicolon, and
5618 one of these commands fails, then the remaining commands will be
5621 (2) If you execute several variables with one call to run (i. e.
5622 calling run with a list of variables as arguments), any failing
5623 command will cause "run" to terminate, i. e. the remaining
5624 variables are not executed.
5626 Note for Redundant Ethernet Interfaces:
5627 =======================================
5629 Some boards come with redundant Ethernet interfaces; U-Boot supports
5630 such configurations and is capable of automatic selection of a
5631 "working" interface when needed. MAC assignment works as follows:
5633 Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
5634 MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
5635 "eth1addr" (=>eth1), "eth2addr", ...
5637 If the network interface stores some valid MAC address (for instance
5638 in SROM), this is used as default address if there is NO correspon-
5639 ding setting in the environment; if the corresponding environment
5640 variable is set, this overrides the settings in the card; that means:
5642 o If the SROM has a valid MAC address, and there is no address in the
5643 environment, the SROM's address is used.
5645 o If there is no valid address in the SROM, and a definition in the
5646 environment exists, then the value from the environment variable is
5649 o If both the SROM and the environment contain a MAC address, and
5650 both addresses are the same, this MAC address is used.
5652 o If both the SROM and the environment contain a MAC address, and the
5653 addresses differ, the value from the environment is used and a
5656 o If neither SROM nor the environment contain a MAC address, an error
5657 is raised. If CONFIG_NET_RANDOM_ETHADDR is defined, then in this case
5658 a random, locally-assigned MAC is used.
5660 If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses
5661 will be programmed into hardware as part of the initialization process. This
5662 may be skipped by setting the appropriate 'ethmacskip' environment variable.
5663 The naming convention is as follows:
5664 "ethmacskip" (=>eth0), "eth1macskip" (=>eth1) etc.
5669 U-Boot is capable of booting (and performing other auxiliary operations on)
5670 images in two formats:
5672 New uImage format (FIT)
5673 -----------------------
5675 Flexible and powerful format based on Flattened Image Tree -- FIT (similar
5676 to Flattened Device Tree). It allows the use of images with multiple
5677 components (several kernels, ramdisks, etc.), with contents protected by
5678 SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory.
5684 Old image format is based on binary files which can be basically anything,
5685 preceded by a special header; see the definitions in include/image.h for
5686 details; basically, the header defines the following image properties:
5688 * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
5689 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
5690 LynxOS, pSOS, QNX, RTEMS, INTEGRITY;
5691 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS,
5693 * Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86,
5694 IA64, MIPS, NDS32, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
5695 Currently supported: ARM, AVR32, Intel x86, MIPS, NDS32, Nios II, PowerPC).
5696 * Compression Type (uncompressed, gzip, bzip2)
5702 The header is marked by a special Magic Number, and both the header
5703 and the data portions of the image are secured against corruption by
5710 Although U-Boot should support any OS or standalone application
5711 easily, the main focus has always been on Linux during the design of
5714 U-Boot includes many features that so far have been part of some
5715 special "boot loader" code within the Linux kernel. Also, any
5716 "initrd" images to be used are no longer part of one big Linux image;
5717 instead, kernel and "initrd" are separate images. This implementation
5718 serves several purposes:
5720 - the same features can be used for other OS or standalone
5721 applications (for instance: using compressed images to reduce the
5722 Flash memory footprint)
5724 - it becomes much easier to port new Linux kernel versions because
5725 lots of low-level, hardware dependent stuff are done by U-Boot
5727 - the same Linux kernel image can now be used with different "initrd"
5728 images; of course this also means that different kernel images can
5729 be run with the same "initrd". This makes testing easier (you don't
5730 have to build a new "zImage.initrd" Linux image when you just
5731 change a file in your "initrd"). Also, a field-upgrade of the
5732 software is easier now.
5738 Porting Linux to U-Boot based systems:
5739 ---------------------------------------
5741 U-Boot cannot save you from doing all the necessary modifications to
5742 configure the Linux device drivers for use with your target hardware
5743 (no, we don't intend to provide a full virtual machine interface to
5746 But now you can ignore ALL boot loader code (in arch/powerpc/mbxboot).
5748 Just make sure your machine specific header file (for instance
5749 include/asm-ppc/tqm8xx.h) includes the same definition of the Board
5750 Information structure as we define in include/asm-<arch>/u-boot.h,
5751 and make sure that your definition of IMAP_ADDR uses the same value
5752 as your U-Boot configuration in CONFIG_SYS_IMMR.
5754 Note that U-Boot now has a driver model, a unified model for drivers.
5755 If you are adding a new driver, plumb it into driver model. If there
5756 is no uclass available, you are encouraged to create one. See
5760 Configuring the Linux kernel:
5761 -----------------------------
5763 No specific requirements for U-Boot. Make sure you have some root
5764 device (initial ramdisk, NFS) for your target system.
5767 Building a Linux Image:
5768 -----------------------
5770 With U-Boot, "normal" build targets like "zImage" or "bzImage" are
5771 not used. If you use recent kernel source, a new build target
5772 "uImage" will exist which automatically builds an image usable by
5773 U-Boot. Most older kernels also have support for a "pImage" target,
5774 which was introduced for our predecessor project PPCBoot and uses a
5775 100% compatible format.
5779 make TQM850L_defconfig
5784 The "uImage" build target uses a special tool (in 'tools/mkimage') to
5785 encapsulate a compressed Linux kernel image with header information,
5786 CRC32 checksum etc. for use with U-Boot. This is what we are doing:
5788 * build a standard "vmlinux" kernel image (in ELF binary format):
5790 * convert the kernel into a raw binary image:
5792 ${CROSS_COMPILE}-objcopy -O binary \
5793 -R .note -R .comment \
5794 -S vmlinux linux.bin
5796 * compress the binary image:
5800 * package compressed binary image for U-Boot:
5802 mkimage -A ppc -O linux -T kernel -C gzip \
5803 -a 0 -e 0 -n "Linux Kernel Image" \
5804 -d linux.bin.gz uImage
5807 The "mkimage" tool can also be used to create ramdisk images for use
5808 with U-Boot, either separated from the Linux kernel image, or
5809 combined into one file. "mkimage" encapsulates the images with a 64
5810 byte header containing information about target architecture,
5811 operating system, image type, compression method, entry points, time
5812 stamp, CRC32 checksums, etc.
5814 "mkimage" can be called in two ways: to verify existing images and
5815 print the header information, or to build new images.
5817 In the first form (with "-l" option) mkimage lists the information
5818 contained in the header of an existing U-Boot image; this includes
5819 checksum verification:
5821 tools/mkimage -l image
5822 -l ==> list image header information
5824 The second form (with "-d" option) is used to build a U-Boot image
5825 from a "data file" which is used as image payload:
5827 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
5828 -n name -d data_file image
5829 -A ==> set architecture to 'arch'
5830 -O ==> set operating system to 'os'
5831 -T ==> set image type to 'type'
5832 -C ==> set compression type 'comp'
5833 -a ==> set load address to 'addr' (hex)
5834 -e ==> set entry point to 'ep' (hex)
5835 -n ==> set image name to 'name'
5836 -d ==> use image data from 'datafile'
5838 Right now, all Linux kernels for PowerPC systems use the same load
5839 address (0x00000000), but the entry point address depends on the
5842 - 2.2.x kernels have the entry point at 0x0000000C,
5843 - 2.3.x and later kernels have the entry point at 0x00000000.
5845 So a typical call to build a U-Boot image would read:
5847 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
5848 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
5849 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz \
5850 > examples/uImage.TQM850L
5851 Image Name: 2.4.4 kernel for TQM850L
5852 Created: Wed Jul 19 02:34:59 2000
5853 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5854 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
5855 Load Address: 0x00000000
5856 Entry Point: 0x00000000
5858 To verify the contents of the image (or check for corruption):
5860 -> tools/mkimage -l examples/uImage.TQM850L
5861 Image Name: 2.4.4 kernel for TQM850L
5862 Created: Wed Jul 19 02:34:59 2000
5863 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5864 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
5865 Load Address: 0x00000000
5866 Entry Point: 0x00000000
5868 NOTE: for embedded systems where boot time is critical you can trade
5869 speed for memory and install an UNCOMPRESSED image instead: this
5870 needs more space in Flash, but boots much faster since it does not
5871 need to be uncompressed:
5873 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz
5874 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
5875 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
5876 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux \
5877 > examples/uImage.TQM850L-uncompressed
5878 Image Name: 2.4.4 kernel for TQM850L
5879 Created: Wed Jul 19 02:34:59 2000
5880 Image Type: PowerPC Linux Kernel Image (uncompressed)
5881 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
5882 Load Address: 0x00000000
5883 Entry Point: 0x00000000
5886 Similar you can build U-Boot images from a 'ramdisk.image.gz' file
5887 when your kernel is intended to use an initial ramdisk:
5889 -> tools/mkimage -n 'Simple Ramdisk Image' \
5890 > -A ppc -O linux -T ramdisk -C gzip \
5891 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
5892 Image Name: Simple Ramdisk Image
5893 Created: Wed Jan 12 14:01:50 2000
5894 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5895 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
5896 Load Address: 0x00000000
5897 Entry Point: 0x00000000
5899 The "dumpimage" is a tool to disassemble images built by mkimage. Its "-i"
5900 option performs the converse operation of the mkimage's second form (the "-d"
5901 option). Given an image built by mkimage, the dumpimage extracts a "data file"
5904 tools/dumpimage -i image -T type -p position data_file
5905 -i ==> extract from the 'image' a specific 'data_file'
5906 -T ==> set image type to 'type'
5907 -p ==> 'position' (starting at 0) of the 'data_file' inside the 'image'
5910 Installing a Linux Image:
5911 -------------------------
5913 To downloading a U-Boot image over the serial (console) interface,
5914 you must convert the image to S-Record format:
5916 objcopy -I binary -O srec examples/image examples/image.srec
5918 The 'objcopy' does not understand the information in the U-Boot
5919 image header, so the resulting S-Record file will be relative to
5920 address 0x00000000. To load it to a given address, you need to
5921 specify the target address as 'offset' parameter with the 'loads'
5924 Example: install the image to address 0x40100000 (which on the
5925 TQM8xxL is in the first Flash bank):
5927 => erase 40100000 401FFFFF
5933 ## Ready for S-Record download ...
5934 ~>examples/image.srec
5935 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
5937 15989 15990 15991 15992
5938 [file transfer complete]
5940 ## Start Addr = 0x00000000
5943 You can check the success of the download using the 'iminfo' command;
5944 this includes a checksum verification so you can be sure no data
5945 corruption happened:
5949 ## Checking Image at 40100000 ...
5950 Image Name: 2.2.13 for initrd on TQM850L
5951 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5952 Data Size: 335725 Bytes = 327 kB = 0 MB
5953 Load Address: 00000000
5954 Entry Point: 0000000c
5955 Verifying Checksum ... OK
5961 The "bootm" command is used to boot an application that is stored in
5962 memory (RAM or Flash). In case of a Linux kernel image, the contents
5963 of the "bootargs" environment variable is passed to the kernel as
5964 parameters. You can check and modify this variable using the
5965 "printenv" and "setenv" commands:
5968 => printenv bootargs
5969 bootargs=root=/dev/ram
5971 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5973 => printenv bootargs
5974 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5977 ## Booting Linux kernel at 40020000 ...
5978 Image Name: 2.2.13 for NFS on TQM850L
5979 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5980 Data Size: 381681 Bytes = 372 kB = 0 MB
5981 Load Address: 00000000
5982 Entry Point: 0000000c
5983 Verifying Checksum ... OK
5984 Uncompressing Kernel Image ... OK
5985 Linux version 2.2.13 (wd@denx.local.net) (gcc version 2.95.2 19991024 (release)) #1 Wed Jul 19 02:35:17 MEST 2000
5986 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5987 time_init: decrementer frequency = 187500000/60
5988 Calibrating delay loop... 49.77 BogoMIPS
5989 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
5992 If you want to boot a Linux kernel with initial RAM disk, you pass
5993 the memory addresses of both the kernel and the initrd image (PPBCOOT
5994 format!) to the "bootm" command:
5996 => imi 40100000 40200000
5998 ## Checking Image at 40100000 ...
5999 Image Name: 2.2.13 for initrd on TQM850L
6000 Image Type: PowerPC Linux Kernel Image (gzip compressed)
6001 Data Size: 335725 Bytes = 327 kB = 0 MB
6002 Load Address: 00000000
6003 Entry Point: 0000000c
6004 Verifying Checksum ... OK
6006 ## Checking Image at 40200000 ...
6007 Image Name: Simple Ramdisk Image
6008 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
6009 Data Size: 566530 Bytes = 553 kB = 0 MB
6010 Load Address: 00000000
6011 Entry Point: 00000000
6012 Verifying Checksum ... OK
6014 => bootm 40100000 40200000
6015 ## Booting Linux kernel at 40100000 ...
6016 Image Name: 2.2.13 for initrd on TQM850L
6017 Image Type: PowerPC Linux Kernel Image (gzip compressed)
6018 Data Size: 335725 Bytes = 327 kB = 0 MB
6019 Load Address: 00000000
6020 Entry Point: 0000000c
6021 Verifying Checksum ... OK
6022 Uncompressing Kernel Image ... OK
6023 ## Loading RAMDisk Image at 40200000 ...
6024 Image Name: Simple Ramdisk Image
6025 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
6026 Data Size: 566530 Bytes = 553 kB = 0 MB
6027 Load Address: 00000000
6028 Entry Point: 00000000
6029 Verifying Checksum ... OK
6030 Loading Ramdisk ... OK
6031 Linux version 2.2.13 (wd@denx.local.net) (gcc version 2.95.2 19991024 (release)) #1 Wed Jul 19 02:32:08 MEST 2000
6032 Boot arguments: root=/dev/ram
6033 time_init: decrementer frequency = 187500000/60
6034 Calibrating delay loop... 49.77 BogoMIPS
6036 RAMDISK: Compressed image found at block 0
6037 VFS: Mounted root (ext2 filesystem).
6041 Boot Linux and pass a flat device tree:
6044 First, U-Boot must be compiled with the appropriate defines. See the section
6045 titled "Linux Kernel Interface" above for a more in depth explanation. The
6046 following is an example of how to start a kernel and pass an updated
6052 oft=oftrees/mpc8540ads.dtb
6053 => tftp $oftaddr $oft
6054 Speed: 1000, full duplex
6056 TFTP from server 192.168.1.1; our IP address is 192.168.1.101
6057 Filename 'oftrees/mpc8540ads.dtb'.
6058 Load address: 0x300000
6061 Bytes transferred = 4106 (100a hex)
6062 => tftp $loadaddr $bootfile
6063 Speed: 1000, full duplex
6065 TFTP from server 192.168.1.1; our IP address is 192.168.1.2
6067 Load address: 0x200000
6068 Loading:############
6070 Bytes transferred = 1029407 (fb51f hex)
6075 => bootm $loadaddr - $oftaddr
6076 ## Booting image at 00200000 ...
6077 Image Name: Linux-2.6.17-dirty
6078 Image Type: PowerPC Linux Kernel Image (gzip compressed)
6079 Data Size: 1029343 Bytes = 1005.2 kB
6080 Load Address: 00000000
6081 Entry Point: 00000000
6082 Verifying Checksum ... OK
6083 Uncompressing Kernel Image ... OK
6084 Booting using flat device tree at 0x300000
6085 Using MPC85xx ADS machine description
6086 Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb
6090 More About U-Boot Image Types:
6091 ------------------------------
6093 U-Boot supports the following image types:
6095 "Standalone Programs" are directly runnable in the environment
6096 provided by U-Boot; it is expected that (if they behave
6097 well) you can continue to work in U-Boot after return from
6098 the Standalone Program.
6099 "OS Kernel Images" are usually images of some Embedded OS which
6100 will take over control completely. Usually these programs
6101 will install their own set of exception handlers, device
6102 drivers, set up the MMU, etc. - this means, that you cannot
6103 expect to re-enter U-Boot except by resetting the CPU.
6104 "RAMDisk Images" are more or less just data blocks, and their
6105 parameters (address, size) are passed to an OS kernel that is
6107 "Multi-File Images" contain several images, typically an OS
6108 (Linux) kernel image and one or more data images like
6109 RAMDisks. This construct is useful for instance when you want
6110 to boot over the network using BOOTP etc., where the boot
6111 server provides just a single image file, but you want to get
6112 for instance an OS kernel and a RAMDisk image.
6114 "Multi-File Images" start with a list of image sizes, each
6115 image size (in bytes) specified by an "uint32_t" in network
6116 byte order. This list is terminated by an "(uint32_t)0".
6117 Immediately after the terminating 0 follow the images, one by
6118 one, all aligned on "uint32_t" boundaries (size rounded up to
6119 a multiple of 4 bytes).
6121 "Firmware Images" are binary images containing firmware (like
6122 U-Boot or FPGA images) which usually will be programmed to
6125 "Script files" are command sequences that will be executed by
6126 U-Boot's command interpreter; this feature is especially
6127 useful when you configure U-Boot to use a real shell (hush)
6128 as command interpreter.
6130 Booting the Linux zImage:
6131 -------------------------
6133 On some platforms, it's possible to boot Linux zImage. This is done
6134 using the "bootz" command. The syntax of "bootz" command is the same
6135 as the syntax of "bootm" command.
6137 Note, defining the CONFIG_SUPPORT_RAW_INITRD allows user to supply
6138 kernel with raw initrd images. The syntax is slightly different, the
6139 address of the initrd must be augmented by it's size, in the following
6140 format: "<initrd addres>:<initrd size>".
6146 One of the features of U-Boot is that you can dynamically load and
6147 run "standalone" applications, which can use some resources of
6148 U-Boot like console I/O functions or interrupt services.
6150 Two simple examples are included with the sources:
6155 'examples/hello_world.c' contains a small "Hello World" Demo
6156 application; it is automatically compiled when you build U-Boot.
6157 It's configured to run at address 0x00040004, so you can play with it
6161 ## Ready for S-Record download ...
6162 ~>examples/hello_world.srec
6163 1 2 3 4 5 6 7 8 9 10 11 ...
6164 [file transfer complete]
6166 ## Start Addr = 0x00040004
6168 => go 40004 Hello World! This is a test.
6169 ## Starting application at 0x00040004 ...
6180 Hit any key to exit ...
6182 ## Application terminated, rc = 0x0
6184 Another example, which demonstrates how to register a CPM interrupt
6185 handler with the U-Boot code, can be found in 'examples/timer.c'.
6186 Here, a CPM timer is set up to generate an interrupt every second.
6187 The interrupt service routine is trivial, just printing a '.'
6188 character, but this is just a demo program. The application can be
6189 controlled by the following keys:
6191 ? - print current values og the CPM Timer registers
6192 b - enable interrupts and start timer
6193 e - stop timer and disable interrupts
6194 q - quit application
6197 ## Ready for S-Record download ...
6198 ~>examples/timer.srec
6199 1 2 3 4 5 6 7 8 9 10 11 ...
6200 [file transfer complete]
6202 ## Start Addr = 0x00040004
6205 ## Starting application at 0x00040004 ...
6208 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
6211 [q, b, e, ?] Set interval 1000000 us
6214 [q, b, e, ?] ........
6215 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
6218 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
6221 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
6224 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
6226 [q, b, e, ?] ...Stopping timer
6228 [q, b, e, ?] ## Application terminated, rc = 0x0
6234 Over time, many people have reported problems when trying to use the
6235 "minicom" terminal emulation program for serial download. I (wd)
6236 consider minicom to be broken, and recommend not to use it. Under
6237 Unix, I recommend to use C-Kermit for general purpose use (and
6238 especially for kermit binary protocol download ("loadb" command), and
6239 use "cu" for S-Record download ("loads" command). See
6240 http://www.denx.de/wiki/view/DULG/SystemSetup#Section_4.3.
6241 for help with kermit.
6244 Nevertheless, if you absolutely want to use it try adding this
6245 configuration to your "File transfer protocols" section:
6247 Name Program Name U/D FullScr IO-Red. Multi
6248 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
6249 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
6255 Starting at version 0.9.2, U-Boot supports NetBSD both as host
6256 (build U-Boot) and target system (boots NetBSD/mpc8xx).
6258 Building requires a cross environment; it is known to work on
6259 NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
6260 need gmake since the Makefiles are not compatible with BSD make).
6261 Note that the cross-powerpc package does not install include files;
6262 attempting to build U-Boot will fail because <machine/ansi.h> is
6263 missing. This file has to be installed and patched manually:
6265 # cd /usr/pkg/cross/powerpc-netbsd/include
6267 # ln -s powerpc machine
6268 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
6269 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
6271 Native builds *don't* work due to incompatibilities between native
6272 and U-Boot include files.
6274 Booting assumes that (the first part of) the image booted is a
6275 stage-2 loader which in turn loads and then invokes the kernel
6276 proper. Loader sources will eventually appear in the NetBSD source
6277 tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
6278 meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz
6281 Implementation Internals:
6282 =========================
6284 The following is not intended to be a complete description of every
6285 implementation detail. However, it should help to understand the
6286 inner workings of U-Boot and make it easier to port it to custom
6290 Initial Stack, Global Data:
6291 ---------------------------
6293 The implementation of U-Boot is complicated by the fact that U-Boot
6294 starts running out of ROM (flash memory), usually without access to
6295 system RAM (because the memory controller is not initialized yet).
6296 This means that we don't have writable Data or BSS segments, and BSS
6297 is not initialized as zero. To be able to get a C environment working
6298 at all, we have to allocate at least a minimal stack. Implementation
6299 options for this are defined and restricted by the CPU used: Some CPU
6300 models provide on-chip memory (like the IMMR area on MPC8xx and
6301 MPC826x processors), on others (parts of) the data cache can be
6302 locked as (mis-) used as memory, etc.
6304 Chris Hallinan posted a good summary of these issues to the
6305 U-Boot mailing list:
6307 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
6308 From: "Chris Hallinan" <clh@net1plus.com>
6309 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
6312 Correct me if I'm wrong, folks, but the way I understand it
6313 is this: Using DCACHE as initial RAM for Stack, etc, does not
6314 require any physical RAM backing up the cache. The cleverness
6315 is that the cache is being used as a temporary supply of
6316 necessary storage before the SDRAM controller is setup. It's
6317 beyond the scope of this list to explain the details, but you
6318 can see how this works by studying the cache architecture and
6319 operation in the architecture and processor-specific manuals.
6321 OCM is On Chip Memory, which I believe the 405GP has 4K. It
6322 is another option for the system designer to use as an
6323 initial stack/RAM area prior to SDRAM being available. Either
6324 option should work for you. Using CS 4 should be fine if your
6325 board designers haven't used it for something that would
6326 cause you grief during the initial boot! It is frequently not
6329 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere
6330 with your processor/board/system design. The default value
6331 you will find in any recent u-boot distribution in
6332 walnut.h should work for you. I'd set it to a value larger
6333 than your SDRAM module. If you have a 64MB SDRAM module, set
6334 it above 400_0000. Just make sure your board has no resources
6335 that are supposed to respond to that address! That code in
6336 start.S has been around a while and should work as is when
6337 you get the config right.
6342 It is essential to remember this, since it has some impact on the C
6343 code for the initialization procedures:
6345 * Initialized global data (data segment) is read-only. Do not attempt
6348 * Do not use any uninitialized global data (or implicitly initialized
6349 as zero data - BSS segment) at all - this is undefined, initiali-
6350 zation is performed later (when relocating to RAM).
6352 * Stack space is very limited. Avoid big data buffers or things like
6355 Having only the stack as writable memory limits means we cannot use
6356 normal global data to share information between the code. But it
6357 turned out that the implementation of U-Boot can be greatly
6358 simplified by making a global data structure (gd_t) available to all
6359 functions. We could pass a pointer to this data as argument to _all_
6360 functions, but this would bloat the code. Instead we use a feature of
6361 the GCC compiler (Global Register Variables) to share the data: we
6362 place a pointer (gd) to the global data into a register which we
6363 reserve for this purpose.
6365 When choosing a register for such a purpose we are restricted by the
6366 relevant (E)ABI specifications for the current architecture, and by
6367 GCC's implementation.
6369 For PowerPC, the following registers have specific use:
6371 R2: reserved for system use
6372 R3-R4: parameter passing and return values
6373 R5-R10: parameter passing
6374 R13: small data area pointer
6378 (U-Boot also uses R12 as internal GOT pointer. r12
6379 is a volatile register so r12 needs to be reset when
6380 going back and forth between asm and C)
6382 ==> U-Boot will use R2 to hold a pointer to the global data
6384 Note: on PPC, we could use a static initializer (since the
6385 address of the global data structure is known at compile time),
6386 but it turned out that reserving a register results in somewhat
6387 smaller code - although the code savings are not that big (on
6388 average for all boards 752 bytes for the whole U-Boot image,
6389 624 text + 127 data).
6391 On Blackfin, the normal C ABI (except for P3) is followed as documented here:
6392 http://docs.blackfin.uclinux.org/doku.php?id=application_binary_interface
6394 ==> U-Boot will use P3 to hold a pointer to the global data
6396 On ARM, the following registers are used:
6398 R0: function argument word/integer result
6399 R1-R3: function argument word
6400 R9: platform specific
6401 R10: stack limit (used only if stack checking is enabled)
6402 R11: argument (frame) pointer
6403 R12: temporary workspace
6406 R15: program counter
6408 ==> U-Boot will use R9 to hold a pointer to the global data
6410 Note: on ARM, only R_ARM_RELATIVE relocations are supported.
6412 On Nios II, the ABI is documented here:
6413 http://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf
6415 ==> U-Boot will use gp to hold a pointer to the global data
6417 Note: on Nios II, we give "-G0" option to gcc and don't use gp
6418 to access small data sections, so gp is free.
6420 On NDS32, the following registers are used:
6422 R0-R1: argument/return
6424 R15: temporary register for assembler
6425 R16: trampoline register
6426 R28: frame pointer (FP)
6427 R29: global pointer (GP)
6428 R30: link register (LP)
6429 R31: stack pointer (SP)
6430 PC: program counter (PC)
6432 ==> U-Boot will use R10 to hold a pointer to the global data
6434 NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope,
6435 or current versions of GCC may "optimize" the code too much.
6440 U-Boot runs in system state and uses physical addresses, i.e. the
6441 MMU is not used either for address mapping nor for memory protection.
6443 The available memory is mapped to fixed addresses using the memory
6444 controller. In this process, a contiguous block is formed for each
6445 memory type (Flash, SDRAM, SRAM), even when it consists of several
6446 physical memory banks.
6448 U-Boot is installed in the first 128 kB of the first Flash bank (on
6449 TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
6450 booting and sizing and initializing DRAM, the code relocates itself
6451 to the upper end of DRAM. Immediately below the U-Boot code some
6452 memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN
6453 configuration setting]. Below that, a structure with global Board
6454 Info data is placed, followed by the stack (growing downward).
6456 Additionally, some exception handler code is copied to the low 8 kB
6457 of DRAM (0x00000000 ... 0x00001FFF).
6459 So a typical memory configuration with 16 MB of DRAM could look like
6462 0x0000 0000 Exception Vector code
6465 0x0000 2000 Free for Application Use
6471 0x00FB FF20 Monitor Stack (Growing downward)
6472 0x00FB FFAC Board Info Data and permanent copy of global data
6473 0x00FC 0000 Malloc Arena
6476 0x00FE 0000 RAM Copy of Monitor Code
6477 ... eventually: LCD or video framebuffer
6478 ... eventually: pRAM (Protected RAM - unchanged by reset)
6479 0x00FF FFFF [End of RAM]
6482 System Initialization:
6483 ----------------------
6485 In the reset configuration, U-Boot starts at the reset entry point
6486 (on most PowerPC systems at address 0x00000100). Because of the reset
6487 configuration for CS0# this is a mirror of the on board Flash memory.
6488 To be able to re-map memory U-Boot then jumps to its link address.
6489 To be able to implement the initialization code in C, a (small!)
6490 initial stack is set up in the internal Dual Ported RAM (in case CPUs
6491 which provide such a feature like MPC8xx or MPC8260), or in a locked
6492 part of the data cache. After that, U-Boot initializes the CPU core,
6493 the caches and the SIU.
6495 Next, all (potentially) available memory banks are mapped using a
6496 preliminary mapping. For example, we put them on 512 MB boundaries
6497 (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
6498 on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
6499 programmed for SDRAM access. Using the temporary configuration, a
6500 simple memory test is run that determines the size of the SDRAM
6503 When there is more than one SDRAM bank, and the banks are of
6504 different size, the largest is mapped first. For equal size, the first
6505 bank (CS2#) is mapped first. The first mapping is always for address
6506 0x00000000, with any additional banks following immediately to create
6507 contiguous memory starting from 0.
6509 Then, the monitor installs itself at the upper end of the SDRAM area
6510 and allocates memory for use by malloc() and for the global Board
6511 Info data; also, the exception vector code is copied to the low RAM
6512 pages, and the final stack is set up.
6514 Only after this relocation will you have a "normal" C environment;
6515 until that you are restricted in several ways, mostly because you are
6516 running from ROM, and because the code will have to be relocated to a
6520 U-Boot Porting Guide:
6521 ----------------------
6523 [Based on messages by Jerry Van Baren in the U-Boot-Users mailing
6527 int main(int argc, char *argv[])
6529 sighandler_t no_more_time;
6531 signal(SIGALRM, no_more_time);
6532 alarm(PROJECT_DEADLINE - toSec (3 * WEEK));
6534 if (available_money > available_manpower) {
6535 Pay consultant to port U-Boot;
6539 Download latest U-Boot source;
6541 Subscribe to u-boot mailing list;
6544 email("Hi, I am new to U-Boot, how do I get started?");
6547 Read the README file in the top level directory;
6548 Read http://www.denx.de/twiki/bin/view/DULG/Manual;
6549 Read applicable doc/*.README;
6550 Read the source, Luke;
6551 /* find . -name "*.[chS]" | xargs grep -i <keyword> */
6554 if (available_money > toLocalCurrency ($2500))
6557 Add a lot of aggravation and time;
6559 if (a similar board exists) { /* hopefully... */
6560 cp -a board/<similar> board/<myboard>
6561 cp include/configs/<similar>.h include/configs/<myboard>.h
6563 Create your own board support subdirectory;
6564 Create your own board include/configs/<myboard>.h file;
6566 Edit new board/<myboard> files
6567 Edit new include/configs/<myboard>.h
6572 Add / modify source code;
6576 email("Hi, I am having problems...");
6578 Send patch file to the U-Boot email list;
6579 if (reasonable critiques)
6580 Incorporate improvements from email list code review;
6582 Defend code as written;
6588 void no_more_time (int sig)
6597 All contributions to U-Boot should conform to the Linux kernel
6598 coding style; see the file "Documentation/CodingStyle" and the script
6599 "scripts/Lindent" in your Linux kernel source directory.
6601 Source files originating from a different project (for example the
6602 MTD subsystem) are generally exempt from these guidelines and are not
6603 reformatted to ease subsequent migration to newer versions of those
6606 Please note that U-Boot is implemented in C (and to some small parts in
6607 Assembler); no C++ is used, so please do not use C++ style comments (//)
6610 Please also stick to the following formatting rules:
6611 - remove any trailing white space
6612 - use TAB characters for indentation and vertical alignment, not spaces
6613 - make sure NOT to use DOS '\r\n' line feeds
6614 - do not add more than 2 consecutive empty lines to source files
6615 - do not add trailing empty lines to source files
6617 Submissions which do not conform to the standards may be returned
6618 with a request to reformat the changes.
6624 Since the number of patches for U-Boot is growing, we need to
6625 establish some rules. Submissions which do not conform to these rules
6626 may be rejected, even when they contain important and valuable stuff.
6628 Please see http://www.denx.de/wiki/U-Boot/Patches for details.
6630 Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>;
6631 see http://lists.denx.de/mailman/listinfo/u-boot
6633 When you send a patch, please include the following information with
6636 * For bug fixes: a description of the bug and how your patch fixes
6637 this bug. Please try to include a way of demonstrating that the
6638 patch actually fixes something.
6640 * For new features: a description of the feature and your
6643 * A CHANGELOG entry as plaintext (separate from the patch)
6645 * For major contributions, your entry to the CREDITS file
6647 * When you add support for a new board, don't forget to add a
6648 maintainer e-mail address to the boards.cfg file, too.
6650 * If your patch adds new configuration options, don't forget to
6651 document these in the README file.
6653 * The patch itself. If you are using git (which is *strongly*
6654 recommended) you can easily generate the patch using the
6655 "git format-patch". If you then use "git send-email" to send it to
6656 the U-Boot mailing list, you will avoid most of the common problems
6657 with some other mail clients.
6659 If you cannot use git, use "diff -purN OLD NEW". If your version of
6660 diff does not support these options, then get the latest version of
6663 The current directory when running this command shall be the parent
6664 directory of the U-Boot source tree (i. e. please make sure that
6665 your patch includes sufficient directory information for the
6668 We prefer patches as plain text. MIME attachments are discouraged,
6669 and compressed attachments must not be used.
6671 * If one logical set of modifications affects or creates several
6672 files, all these changes shall be submitted in a SINGLE patch file.
6674 * Changesets that contain different, unrelated modifications shall be
6675 submitted as SEPARATE patches, one patch per changeset.
6680 * Before sending the patch, run the MAKEALL script on your patched
6681 source tree and make sure that no errors or warnings are reported
6682 for any of the boards.
6684 * Keep your modifications to the necessary minimum: A patch
6685 containing several unrelated changes or arbitrary reformats will be
6686 returned with a request to re-formatting / split it.
6688 * If you modify existing code, make sure that your new code does not
6689 add to the memory footprint of the code ;-) Small is beautiful!
6690 When adding new features, these should compile conditionally only
6691 (using #ifdef), and the resulting code with the new feature
6692 disabled must not need more memory than the old code without your
6695 * Remember that there is a size limit of 100 kB per message on the
6696 u-boot mailing list. Bigger patches will be moderated. If they are
6697 reasonable and not too big, they will be acknowledged. But patches
6698 bigger than the size limit should be avoided.
projects / u-boot / blob