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 /74xx_7xx Files specific to Freescale MPC74xx and 7xx CPUs
186 /mpc5xx Files specific to Freescale MPC5xx CPUs
187 /mpc5xxx Files specific to Freescale MPC5xxx CPUs
188 /mpc8xx Files specific to Freescale MPC8xx CPUs
189 /mpc824x Files specific to Freescale MPC824x CPUs
190 /mpc8260 Files specific to Freescale MPC8260 CPUs
191 /mpc85xx Files specific to Freescale MPC85xx CPUs
192 /ppc4xx Files specific to AMCC PowerPC 4xx CPUs
193 /lib Architecture specific library files
194 /sh Files generic to SH architecture
195 /cpu CPU specific files
196 /sh2 Files specific to sh2 CPUs
197 /sh3 Files specific to sh3 CPUs
198 /sh4 Files specific to sh4 CPUs
199 /lib Architecture specific library files
200 /sparc Files generic to SPARC architecture
201 /cpu CPU specific files
202 /leon2 Files specific to Gaisler LEON2 SPARC CPU
203 /leon3 Files specific to Gaisler LEON3 SPARC CPU
204 /lib Architecture specific library files
205 /x86 Files generic to x86 architecture
206 /cpu CPU specific files
207 /lib Architecture specific library files
208 /api Machine/arch independent API for external apps
209 /board Board dependent files
210 /common Misc architecture independent functions
211 /disk Code for disk drive partition handling
212 /doc Documentation (don't expect too much)
213 /drivers Commonly used device drivers
214 /dts Contains Makefile for building internal U-Boot fdt.
215 /examples Example code for standalone applications, etc.
216 /fs Filesystem code (cramfs, ext2, jffs2, etc.)
217 /include Header Files
218 /lib Files generic to all architectures
219 /libfdt Library files to support flattened device trees
220 /lzma Library files to support LZMA decompression
221 /lzo Library files to support LZO decompression
223 /post Power On Self Test
224 /spl Secondary Program Loader framework
225 /tools Tools to build S-Record or U-Boot images, etc.
227 Software Configuration:
228 =======================
230 Configuration is usually done using C preprocessor defines; the
231 rationale behind that is to avoid dead code whenever possible.
233 There are two classes of configuration variables:
235 * Configuration _OPTIONS_:
236 These are selectable by the user and have names beginning with
239 * Configuration _SETTINGS_:
240 These depend on the hardware etc. and should not be meddled with if
241 you don't know what you're doing; they have names beginning with
244 Later we will add a configuration tool - probably similar to or even
245 identical to what's used for the Linux kernel. Right now, we have to
246 do the configuration by hand, which means creating some symbolic
247 links and editing some configuration files. We use the TQM8xxL boards
251 Selection of Processor Architecture and Board Type:
252 ---------------------------------------------------
254 For all supported boards there are ready-to-use default
255 configurations available; just type "make <board_name>_defconfig".
257 Example: For a TQM823L module type:
260 make TQM823L_defconfig
262 For the Cogent platform, you need to specify the CPU type as well;
263 e.g. "make cogent_mpc8xx_defconfig". And also configure the cogent
264 directory according to the instructions in cogent/README.
270 U-Boot can be built natively to run on a Linux host using the 'sandbox'
271 board. This allows feature development which is not board- or architecture-
272 specific to be undertaken on a native platform. The sandbox is also used to
273 run some of U-Boot's tests.
275 See board/sandbox/README.sandbox for more details.
278 Configuration Options:
279 ----------------------
281 Configuration depends on the combination of board and CPU type; all
282 such information is kept in a configuration file
283 "include/configs/<board_name>.h".
285 Example: For a TQM823L module, all configuration settings are in
286 "include/configs/TQM823L.h".
289 Many of the options are named exactly as the corresponding Linux
290 kernel configuration options. The intention is to make it easier to
291 build a config tool - later.
294 The following options need to be configured:
296 - CPU Type: Define exactly one, e.g. CONFIG_MPC85XX.
298 - Board Type: Define exactly one, e.g. CONFIG_MPC8540ADS.
300 - CPU Daughterboard Type: (if CONFIG_ATSTK1000 is defined)
301 Define exactly one, e.g. CONFIG_ATSTK1002
303 - CPU Module Type: (if CONFIG_COGENT is defined)
304 Define exactly one of
306 --- FIXME --- not tested yet:
307 CONFIG_CMA286_60, CONFIG_CMA286_21, CONFIG_CMA286_60P,
308 CONFIG_CMA287_23, CONFIG_CMA287_50
310 - Motherboard Type: (if CONFIG_COGENT is defined)
311 Define exactly one of
312 CONFIG_CMA101, CONFIG_CMA102
314 - Motherboard I/O Modules: (if CONFIG_COGENT is defined)
315 Define one or more of
318 - Motherboard Options: (if CONFIG_CMA101 or CONFIG_CMA102 are defined)
319 Define one or more of
320 CONFIG_LCD_HEARTBEAT - update a character position on
321 the LCD display every second with
324 - Marvell Family Member
325 CONFIG_SYS_MVFS - define it if you want to enable
326 multiple fs option at one time
327 for marvell soc family
329 - MPC824X Family Member (if CONFIG_MPC824X is defined)
330 Define exactly one of
331 CONFIG_MPC8240, CONFIG_MPC8245
333 - 8xx CPU Options: (if using an MPC8xx CPU)
334 CONFIG_8xx_GCLK_FREQ - deprecated: CPU clock if
335 get_gclk_freq() cannot work
336 e.g. if there is no 32KHz
337 reference PIT/RTC clock
338 CONFIG_8xx_OSCLK - PLL input clock (either EXTCLK
341 - 859/866/885 CPU options: (if using a MPC859 or MPC866 or MPC885 CPU):
342 CONFIG_SYS_8xx_CPUCLK_MIN
343 CONFIG_SYS_8xx_CPUCLK_MAX
344 CONFIG_8xx_CPUCLK_DEFAULT
345 See doc/README.MPC866
347 CONFIG_SYS_MEASURE_CPUCLK
349 Define this to measure the actual CPU clock instead
350 of relying on the correctness of the configured
351 values. Mostly useful for board bringup to make sure
352 the PLL is locked at the intended frequency. Note
353 that this requires a (stable) reference clock (32 kHz
354 RTC clock or CONFIG_SYS_8XX_XIN)
356 CONFIG_SYS_DELAYED_ICACHE
358 Define this option if you want to enable the
359 ICache only when Code runs from RAM.
364 Specifies that the core is a 64-bit PowerPC implementation (implements
365 the "64" category of the Power ISA). This is necessary for ePAPR
366 compliance, among other possible reasons.
368 CONFIG_SYS_FSL_TBCLK_DIV
370 Defines the core time base clock divider ratio compared to the
371 system clock. On most PQ3 devices this is 8, on newer QorIQ
372 devices it can be 16 or 32. The ratio varies from SoC to Soc.
374 CONFIG_SYS_FSL_PCIE_COMPAT
376 Defines the string to utilize when trying to match PCIe device
377 tree nodes for the given platform.
379 CONFIG_SYS_PPC_E500_DEBUG_TLB
381 Enables a temporary TLB entry to be used during boot to work
382 around limitations in e500v1 and e500v2 external debugger
383 support. This reduces the portions of the boot code where
384 breakpoints and single stepping do not work. The value of this
385 symbol should be set to the TLB1 entry to be used for this
388 CONFIG_SYS_FSL_ERRATUM_A004510
390 Enables a workaround for erratum A004510. If set,
391 then CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV and
392 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY must be set.
394 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV
395 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV2 (optional)
397 Defines one or two SoC revisions (low 8 bits of SVR)
398 for which the A004510 workaround should be applied.
400 The rest of SVR is either not relevant to the decision
401 of whether the erratum is present (e.g. p2040 versus
402 p2041) or is implied by the build target, which controls
403 whether CONFIG_SYS_FSL_ERRATUM_A004510 is set.
405 See Freescale App Note 4493 for more information about
408 CONFIG_A003399_NOR_WORKAROUND
409 Enables a workaround for IFC erratum A003399. It is only
410 requred during NOR boot.
412 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY
414 This is the value to write into CCSR offset 0x18600
415 according to the A004510 workaround.
417 CONFIG_SYS_FSL_DSP_DDR_ADDR
418 This value denotes start offset of DDR memory which is
419 connected exclusively to the DSP cores.
421 CONFIG_SYS_FSL_DSP_M2_RAM_ADDR
422 This value denotes start offset of M2 memory
423 which is directly connected to the DSP core.
425 CONFIG_SYS_FSL_DSP_M3_RAM_ADDR
426 This value denotes start offset of M3 memory which is directly
427 connected to the DSP core.
429 CONFIG_SYS_FSL_DSP_CCSRBAR_DEFAULT
430 This value denotes start offset of DSP CCSR space.
432 CONFIG_SYS_FSL_SINGLE_SOURCE_CLK
433 Single Source Clock is clocking mode present in some of FSL SoC's.
434 In this mode, a single differential clock is used to supply
435 clocks to the sysclock, ddrclock and usbclock.
437 CONFIG_SYS_CPC_REINIT_F
438 This CONFIG is defined when the CPC is configured as SRAM at the
439 time of U-boot entry and is required to be re-initialized.
442 Inidcates this SoC supports deep sleep feature. If deep sleep is
443 supported, core will start to execute uboot when wakes up.
445 - Generic CPU options:
446 CONFIG_SYS_GENERIC_GLOBAL_DATA
447 Defines global data is initialized in generic board board_init_f().
448 If this macro is defined, global data is created and cleared in
449 generic board board_init_f(). Without this macro, architecture/board
450 should initialize global data before calling board_init_f().
452 CONFIG_SYS_BIG_ENDIAN, CONFIG_SYS_LITTLE_ENDIAN
454 Defines the endianess of the CPU. Implementation of those
455 values is arch specific.
458 Freescale DDR driver in use. This type of DDR controller is
459 found in mpc83xx, mpc85xx, mpc86xx as well as some ARM core
462 CONFIG_SYS_FSL_DDR_ADDR
463 Freescale DDR memory-mapped register base.
465 CONFIG_SYS_FSL_DDR_EMU
466 Specify emulator support for DDR. Some DDR features such as
467 deskew training are not available.
469 CONFIG_SYS_FSL_DDRC_GEN1
470 Freescale DDR1 controller.
472 CONFIG_SYS_FSL_DDRC_GEN2
473 Freescale DDR2 controller.
475 CONFIG_SYS_FSL_DDRC_GEN3
476 Freescale DDR3 controller.
478 CONFIG_SYS_FSL_DDRC_GEN4
479 Freescale DDR4 controller.
481 CONFIG_SYS_FSL_DDRC_ARM_GEN3
482 Freescale DDR3 controller for ARM-based SoCs.
485 Board config to use DDR1. It can be enabled for SoCs with
486 Freescale DDR1 or DDR2 controllers, depending on the board
490 Board config to use DDR2. It can be eanbeld for SoCs with
491 Freescale DDR2 or DDR3 controllers, depending on the board
495 Board config to use DDR3. It can be enabled for SoCs with
496 Freescale DDR3 or DDR3L controllers.
499 Board config to use DDR3L. It can be enabled for SoCs with
503 Board config to use DDR4. It can be enabled for SoCs with
506 CONFIG_SYS_FSL_IFC_BE
507 Defines the IFC controller register space as Big Endian
509 CONFIG_SYS_FSL_IFC_LE
510 Defines the IFC controller register space as Little Endian
512 CONFIG_SYS_FSL_PBL_PBI
513 It enables addition of RCW (Power on reset configuration) in built image.
514 Please refer doc/README.pblimage for more details
516 CONFIG_SYS_FSL_PBL_RCW
517 It adds PBI(pre-boot instructions) commands in u-boot build image.
518 PBI commands can be used to configure SoC before it starts the execution.
519 Please refer doc/README.pblimage for more details
522 It adds a target to create boot binary having SPL binary in PBI format
523 concatenated with u-boot binary.
525 CONFIG_SYS_FSL_DDR_BE
526 Defines the DDR controller register space as Big Endian
528 CONFIG_SYS_FSL_DDR_LE
529 Defines the DDR controller register space as Little Endian
531 CONFIG_SYS_FSL_DDR_SDRAM_BASE_PHY
532 Physical address from the view of DDR controllers. It is the
533 same as CONFIG_SYS_DDR_SDRAM_BASE for all Power SoCs. But
534 it could be different for ARM SoCs.
536 CONFIG_SYS_FSL_DDR_INTLV_256B
537 DDR controller interleaving on 256-byte. This is a special
538 interleaving mode, handled by Dickens for Freescale layerscape
541 CONFIG_SYS_FSL_DDR_MAIN_NUM_CTRLS
542 Number of controllers used as main memory.
544 CONFIG_SYS_FSL_OTHER_DDR_NUM_CTRLS
545 Number of controllers used for other than main memory.
547 - Intel Monahans options:
548 CONFIG_SYS_MONAHANS_RUN_MODE_OSC_RATIO
550 Defines the Monahans run mode to oscillator
551 ratio. Valid values are 8, 16, 24, 31. The core
552 frequency is this value multiplied by 13 MHz.
554 CONFIG_SYS_MONAHANS_TURBO_RUN_MODE_RATIO
556 Defines the Monahans turbo mode to oscillator
557 ratio. Valid values are 1 (default if undefined) and
558 2. The core frequency as calculated above is multiplied
562 CONFIG_SYS_INIT_SP_OFFSET
564 Offset relative to CONFIG_SYS_SDRAM_BASE for initial stack
565 pointer. This is needed for the temporary stack before
568 CONFIG_SYS_MIPS_CACHE_MODE
570 Cache operation mode for the MIPS CPU.
571 See also arch/mips/include/asm/mipsregs.h.
573 CONF_CM_CACHABLE_NO_WA
576 CONF_CM_CACHABLE_NONCOHERENT
580 CONF_CM_CACHABLE_ACCELERATED
582 CONFIG_SYS_XWAY_EBU_BOOTCFG
584 Special option for Lantiq XWAY SoCs for booting from NOR flash.
585 See also arch/mips/cpu/mips32/start.S.
587 CONFIG_XWAY_SWAP_BYTES
589 Enable compilation of tools/xway-swap-bytes needed for Lantiq
590 XWAY SoCs for booting from NOR flash. The U-Boot image needs to
591 be swapped if a flash programmer is used.
594 CONFIG_SYS_EXCEPTION_VECTORS_HIGH
596 Select high exception vectors of the ARM core, e.g., do not
597 clear the V bit of the c1 register of CP15.
599 CONFIG_SYS_THUMB_BUILD
601 Use this flag to build U-Boot using the Thumb instruction
602 set for ARM architectures. Thumb instruction set provides
603 better code density. For ARM architectures that support
604 Thumb2 this flag will result in Thumb2 code generated by
607 CONFIG_ARM_ERRATA_716044
608 CONFIG_ARM_ERRATA_742230
609 CONFIG_ARM_ERRATA_743622
610 CONFIG_ARM_ERRATA_751472
611 CONFIG_ARM_ERRATA_794072
612 CONFIG_ARM_ERRATA_761320
614 If set, the workarounds for these ARM errata are applied early
615 during U-Boot startup. Note that these options force the
616 workarounds to be applied; no CPU-type/version detection
617 exists, unlike the similar options in the Linux kernel. Do not
618 set these options unless they apply!
623 The frequency of the timer returned by get_timer().
624 get_timer() must operate in milliseconds and this CONFIG
625 option must be set to 1000.
627 - Linux Kernel Interface:
630 U-Boot stores all clock information in Hz
631 internally. For binary compatibility with older Linux
632 kernels (which expect the clocks passed in the
633 bd_info data to be in MHz) the environment variable
634 "clocks_in_mhz" can be defined so that U-Boot
635 converts clock data to MHZ before passing it to the
637 When CONFIG_CLOCKS_IN_MHZ is defined, a definition of
638 "clocks_in_mhz=1" is automatically included in the
641 CONFIG_MEMSIZE_IN_BYTES [relevant for MIPS only]
643 When transferring memsize parameter to linux, some versions
644 expect it to be in bytes, others in MB.
645 Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes.
649 New kernel versions are expecting firmware settings to be
650 passed using flattened device trees (based on open firmware
654 * New libfdt-based support
655 * Adds the "fdt" command
656 * The bootm command automatically updates the fdt
658 OF_CPU - The proper name of the cpus node (only required for
659 MPC512X and MPC5xxx based boards).
660 OF_SOC - The proper name of the soc node (only required for
661 MPC512X and MPC5xxx based boards).
662 OF_TBCLK - The timebase frequency.
663 OF_STDOUT_PATH - The path to the console device
665 boards with QUICC Engines require OF_QE to set UCC MAC
668 CONFIG_OF_BOARD_SETUP
670 Board code has addition modification that it wants to make
671 to the flat device tree before handing it off to the kernel
675 This define fills in the correct boot CPU in the boot
676 param header, the default value is zero if undefined.
680 U-Boot can detect if an IDE device is present or not.
681 If not, and this new config option is activated, U-Boot
682 removes the ATA node from the DTS before booting Linux,
683 so the Linux IDE driver does not probe the device and
684 crash. This is needed for buggy hardware (uc101) where
685 no pull down resistor is connected to the signal IDE5V_DD7.
687 CONFIG_MACH_TYPE [relevant for ARM only][mandatory]
689 This setting is mandatory for all boards that have only one
690 machine type and must be used to specify the machine type
691 number as it appears in the ARM machine registry
692 (see http://www.arm.linux.org.uk/developer/machines/).
693 Only boards that have multiple machine types supported
694 in a single configuration file and the machine type is
695 runtime discoverable, do not have to use this setting.
697 - vxWorks boot parameters:
699 bootvx constructs a valid bootline using the following
700 environments variables: bootfile, ipaddr, serverip, hostname.
701 It loads the vxWorks image pointed bootfile.
703 CONFIG_SYS_VXWORKS_BOOT_DEVICE - The vxworks device name
704 CONFIG_SYS_VXWORKS_MAC_PTR - Ethernet 6 byte MA -address
705 CONFIG_SYS_VXWORKS_SERVERNAME - Name of the server
706 CONFIG_SYS_VXWORKS_BOOT_ADDR - Address of boot parameters
708 CONFIG_SYS_VXWORKS_ADD_PARAMS
710 Add it at the end of the bootline. E.g "u=username pw=secret"
712 Note: If a "bootargs" environment is defined, it will overwride
713 the defaults discussed just above.
715 - Cache Configuration:
716 CONFIG_SYS_ICACHE_OFF - Do not enable instruction cache in U-Boot
717 CONFIG_SYS_DCACHE_OFF - Do not enable data cache in U-Boot
718 CONFIG_SYS_L2CACHE_OFF- Do not enable L2 cache in U-Boot
720 - Cache Configuration for ARM:
721 CONFIG_SYS_L2_PL310 - Enable support for ARM PL310 L2 cache
723 CONFIG_SYS_PL310_BASE - Physical base address of PL310
724 controller register space
729 Define this if you want support for Amba PrimeCell PL010 UARTs.
733 Define this if you want support for Amba PrimeCell PL011 UARTs.
737 If you have Amba PrimeCell PL011 UARTs, set this variable to
738 the clock speed of the UARTs.
742 If you have Amba PrimeCell PL010 or PL011 UARTs on your board,
743 define this to a list of base addresses for each (supported)
744 port. See e.g. include/configs/versatile.h
746 CONFIG_PL011_SERIAL_RLCR
748 Some vendor versions of PL011 serial ports (e.g. ST-Ericsson U8500)
749 have separate receive and transmit line control registers. Set
750 this variable to initialize the extra register.
752 CONFIG_PL011_SERIAL_FLUSH_ON_INIT
754 On some platforms (e.g. U8500) U-Boot is loaded by a second stage
755 boot loader that has already initialized the UART. Define this
756 variable to flush the UART at init time.
758 CONFIG_SERIAL_HW_FLOW_CONTROL
760 Define this variable to enable hw flow control in serial driver.
761 Current user of this option is drivers/serial/nsl16550.c driver
764 Depending on board, define exactly one serial port
765 (like CONFIG_8xx_CONS_SMC1, CONFIG_8xx_CONS_SMC2,
766 CONFIG_8xx_CONS_SCC1, ...), or switch off the serial
767 console by defining CONFIG_8xx_CONS_NONE
769 Note: if CONFIG_8xx_CONS_NONE is defined, the serial
770 port routines must be defined elsewhere
771 (i.e. serial_init(), serial_getc(), ...)
774 Enables console device for a color framebuffer. Needs following
775 defines (cf. smiLynxEM, i8042)
776 VIDEO_FB_LITTLE_ENDIAN graphic memory organisation
778 VIDEO_HW_RECTFILL graphic chip supports
781 VIDEO_HW_BITBLT graphic chip supports
782 bit-blit (cf. smiLynxEM)
783 VIDEO_VISIBLE_COLS visible pixel columns
785 VIDEO_VISIBLE_ROWS visible pixel rows
786 VIDEO_PIXEL_SIZE bytes per pixel
787 VIDEO_DATA_FORMAT graphic data format
788 (0-5, cf. cfb_console.c)
789 VIDEO_FB_ADRS framebuffer address
790 VIDEO_KBD_INIT_FCT keyboard int fct
791 (i.e. i8042_kbd_init())
792 VIDEO_TSTC_FCT test char fct
794 VIDEO_GETC_FCT get char fct
796 CONFIG_CONSOLE_CURSOR cursor drawing on/off
797 (requires blink timer
799 CONFIG_SYS_CONSOLE_BLINK_COUNT blink interval (cf. i8042.c)
800 CONFIG_CONSOLE_TIME display time/date info in
802 (requires CONFIG_CMD_DATE)
803 CONFIG_VIDEO_LOGO display Linux logo in
805 CONFIG_VIDEO_BMP_LOGO use bmp_logo.h instead of
806 linux_logo.h for logo.
807 Requires CONFIG_VIDEO_LOGO
808 CONFIG_CONSOLE_EXTRA_INFO
809 additional board info beside
812 When CONFIG_CFB_CONSOLE_ANSI is defined, console will support
813 a limited number of ANSI escape sequences (cursor control,
814 erase functions and limited graphics rendition control).
816 When CONFIG_CFB_CONSOLE is defined, video console is
817 default i/o. Serial console can be forced with
818 environment 'console=serial'.
820 When CONFIG_SILENT_CONSOLE is defined, all console
821 messages (by U-Boot and Linux!) can be silenced with
822 the "silent" environment variable. See
823 doc/README.silent for more information.
825 CONFIG_SYS_CONSOLE_BG_COL: define the backgroundcolor, default
827 CONFIG_SYS_CONSOLE_FG_COL: define the foregroundcolor, default
831 CONFIG_BAUDRATE - in bps
832 Select one of the baudrates listed in
833 CONFIG_SYS_BAUDRATE_TABLE, see below.
834 CONFIG_SYS_BRGCLK_PRESCALE, baudrate prescale
836 - Console Rx buffer length
837 With CONFIG_SYS_SMC_RXBUFLEN it is possible to define
838 the maximum receive buffer length for the SMC.
839 This option is actual only for 82xx and 8xx possible.
840 If using CONFIG_SYS_SMC_RXBUFLEN also CONFIG_SYS_MAXIDLE
841 must be defined, to setup the maximum idle timeout for
844 - Pre-Console Buffer:
845 Prior to the console being initialised (i.e. serial UART
846 initialised etc) all console output is silently discarded.
847 Defining CONFIG_PRE_CONSOLE_BUFFER will cause U-Boot to
848 buffer any console messages prior to the console being
849 initialised to a buffer of size CONFIG_PRE_CON_BUF_SZ
850 bytes located at CONFIG_PRE_CON_BUF_ADDR. The buffer is
851 a circular buffer, so if more than CONFIG_PRE_CON_BUF_SZ
852 bytes are output before the console is initialised, the
853 earlier bytes are discarded.
855 'Sane' compilers will generate smaller code if
856 CONFIG_PRE_CON_BUF_SZ is a power of 2
858 - Safe printf() functions
859 Define CONFIG_SYS_VSNPRINTF to compile in safe versions of
860 the printf() functions. These are defined in
861 include/vsprintf.h and include snprintf(), vsnprintf() and
862 so on. Code size increase is approximately 300-500 bytes.
863 If this option is not given then these functions will
864 silently discard their buffer size argument - this means
865 you are not getting any overflow checking in this case.
867 - Boot Delay: CONFIG_BOOTDELAY - in seconds
868 Delay before automatically booting the default image;
869 set to -1 to disable autoboot.
870 set to -2 to autoboot with no delay and not check for abort
871 (even when CONFIG_ZERO_BOOTDELAY_CHECK is defined).
873 See doc/README.autoboot for these options that
874 work with CONFIG_BOOTDELAY. None are required.
875 CONFIG_BOOT_RETRY_TIME
876 CONFIG_BOOT_RETRY_MIN
877 CONFIG_AUTOBOOT_KEYED
878 CONFIG_AUTOBOOT_PROMPT
879 CONFIG_AUTOBOOT_DELAY_STR
880 CONFIG_AUTOBOOT_STOP_STR
881 CONFIG_AUTOBOOT_DELAY_STR2
882 CONFIG_AUTOBOOT_STOP_STR2
883 CONFIG_ZERO_BOOTDELAY_CHECK
884 CONFIG_RESET_TO_RETRY
888 Only needed when CONFIG_BOOTDELAY is enabled;
889 define a command string that is automatically executed
890 when no character is read on the console interface
891 within "Boot Delay" after reset.
894 This can be used to pass arguments to the bootm
895 command. The value of CONFIG_BOOTARGS goes into the
896 environment value "bootargs".
898 CONFIG_RAMBOOT and CONFIG_NFSBOOT
899 The value of these goes into the environment as
900 "ramboot" and "nfsboot" respectively, and can be used
901 as a convenience, when switching between booting from
905 CONFIG_BOOTCOUNT_LIMIT
906 Implements a mechanism for detecting a repeating reboot
908 http://www.denx.de/wiki/view/DULG/UBootBootCountLimit
911 If no softreset save registers are found on the hardware
912 "bootcount" is stored in the environment. To prevent a
913 saveenv on all reboots, the environment variable
914 "upgrade_available" is used. If "upgrade_available" is
915 0, "bootcount" is always 0, if "upgrade_available" is
916 1 "bootcount" is incremented in the environment.
917 So the Userspace Applikation must set the "upgrade_available"
918 and "bootcount" variable to 0, if a boot was successfully.
923 When this option is #defined, the existence of the
924 environment variable "preboot" will be checked
925 immediately before starting the CONFIG_BOOTDELAY
926 countdown and/or running the auto-boot command resp.
927 entering interactive mode.
929 This feature is especially useful when "preboot" is
930 automatically generated or modified. For an example
931 see the LWMON board specific code: here "preboot" is
932 modified when the user holds down a certain
933 combination of keys on the (special) keyboard when
936 - Serial Download Echo Mode:
938 If defined to 1, all characters received during a
939 serial download (using the "loads" command) are
940 echoed back. This might be needed by some terminal
941 emulations (like "cu"), but may as well just take
942 time on others. This setting #define's the initial
943 value of the "loads_echo" environment variable.
945 - Kgdb Serial Baudrate: (if CONFIG_CMD_KGDB is defined)
947 Select one of the baudrates listed in
948 CONFIG_SYS_BAUDRATE_TABLE, see below.
951 Monitor commands can be included or excluded
952 from the build by using the #include files
953 <config_cmd_all.h> and #undef'ing unwanted
954 commands, or using <config_cmd_default.h>
955 and augmenting with additional #define's
958 The default command configuration includes all commands
959 except those marked below with a "*".
961 CONFIG_CMD_AES AES 128 CBC encrypt/decrypt
962 CONFIG_CMD_ASKENV * ask for env variable
963 CONFIG_CMD_BDI bdinfo
964 CONFIG_CMD_BEDBUG * Include BedBug Debugger
965 CONFIG_CMD_BMP * BMP support
966 CONFIG_CMD_BSP * Board specific commands
967 CONFIG_CMD_BOOTD bootd
968 CONFIG_CMD_BOOTI * ARM64 Linux kernel Image support
969 CONFIG_CMD_CACHE * icache, dcache
970 CONFIG_CMD_CLK * clock command support
971 CONFIG_CMD_CONSOLE coninfo
972 CONFIG_CMD_CRC32 * crc32
973 CONFIG_CMD_DATE * support for RTC, date/time...
974 CONFIG_CMD_DHCP * DHCP support
975 CONFIG_CMD_DIAG * Diagnostics
976 CONFIG_CMD_DS4510 * ds4510 I2C gpio commands
977 CONFIG_CMD_DS4510_INFO * ds4510 I2C info command
978 CONFIG_CMD_DS4510_MEM * ds4510 I2C eeprom/sram commansd
979 CONFIG_CMD_DS4510_RST * ds4510 I2C rst command
980 CONFIG_CMD_DTT * Digital Therm and Thermostat
981 CONFIG_CMD_ECHO echo arguments
982 CONFIG_CMD_EDITENV edit env variable
983 CONFIG_CMD_EEPROM * EEPROM read/write support
984 CONFIG_CMD_ELF * bootelf, bootvx
985 CONFIG_CMD_ENV_CALLBACK * display details about env callbacks
986 CONFIG_CMD_ENV_FLAGS * display details about env flags
987 CONFIG_CMD_ENV_EXISTS * check existence of env variable
988 CONFIG_CMD_EXPORTENV * export the environment
989 CONFIG_CMD_EXT2 * ext2 command support
990 CONFIG_CMD_EXT4 * ext4 command support
991 CONFIG_CMD_FS_GENERIC * filesystem commands (e.g. load, ls)
992 that work for multiple fs types
993 CONFIG_CMD_SAVEENV saveenv
994 CONFIG_CMD_FDC * Floppy Disk Support
995 CONFIG_CMD_FAT * FAT command support
996 CONFIG_CMD_FLASH flinfo, erase, protect
997 CONFIG_CMD_FPGA FPGA device initialization support
998 CONFIG_CMD_FUSE * Device fuse support
999 CONFIG_CMD_GETTIME * Get time since boot
1000 CONFIG_CMD_GO * the 'go' command (exec code)
1001 CONFIG_CMD_GREPENV * search environment
1002 CONFIG_CMD_HASH * calculate hash / digest
1003 CONFIG_CMD_HWFLOW * RTS/CTS hw flow control
1004 CONFIG_CMD_I2C * I2C serial bus support
1005 CONFIG_CMD_IDE * IDE harddisk support
1006 CONFIG_CMD_IMI iminfo
1007 CONFIG_CMD_IMLS List all images found in NOR flash
1008 CONFIG_CMD_IMLS_NAND * List all images found in NAND flash
1009 CONFIG_CMD_IMMAP * IMMR dump support
1010 CONFIG_CMD_IOTRACE * I/O tracing for debugging
1011 CONFIG_CMD_IMPORTENV * import an environment
1012 CONFIG_CMD_INI * import data from an ini file into the env
1013 CONFIG_CMD_IRQ * irqinfo
1014 CONFIG_CMD_ITEST Integer/string test of 2 values
1015 CONFIG_CMD_JFFS2 * JFFS2 Support
1016 CONFIG_CMD_KGDB * kgdb
1017 CONFIG_CMD_LDRINFO * ldrinfo (display Blackfin loader)
1018 CONFIG_CMD_LINK_LOCAL * link-local IP address auto-configuration
1020 CONFIG_CMD_LOADB loadb
1021 CONFIG_CMD_LOADS loads
1022 CONFIG_CMD_MD5SUM * print md5 message digest
1023 (requires CONFIG_CMD_MEMORY and CONFIG_MD5)
1024 CONFIG_CMD_MEMINFO * Display detailed memory information
1025 CONFIG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base,
1027 CONFIG_CMD_MEMTEST * mtest
1028 CONFIG_CMD_MISC Misc functions like sleep etc
1029 CONFIG_CMD_MMC * MMC memory mapped support
1030 CONFIG_CMD_MII * MII utility commands
1031 CONFIG_CMD_MTDPARTS * MTD partition support
1032 CONFIG_CMD_NAND * NAND support
1033 CONFIG_CMD_NET bootp, tftpboot, rarpboot
1034 CONFIG_CMD_NFS NFS support
1035 CONFIG_CMD_PCA953X * PCA953x I2C gpio commands
1036 CONFIG_CMD_PCA953X_INFO * PCA953x I2C gpio info command
1037 CONFIG_CMD_PCI * pciinfo
1038 CONFIG_CMD_PCMCIA * PCMCIA support
1039 CONFIG_CMD_PING * send ICMP ECHO_REQUEST to network
1041 CONFIG_CMD_PORTIO * Port I/O
1042 CONFIG_CMD_READ * Read raw data from partition
1043 CONFIG_CMD_REGINFO * Register dump
1044 CONFIG_CMD_RUN run command in env variable
1045 CONFIG_CMD_SANDBOX * sb command to access sandbox features
1046 CONFIG_CMD_SAVES * save S record dump
1047 CONFIG_CMD_SCSI * SCSI Support
1048 CONFIG_CMD_SDRAM * print SDRAM configuration information
1049 (requires CONFIG_CMD_I2C)
1050 CONFIG_CMD_SETGETDCR Support for DCR Register access
1052 CONFIG_CMD_SF * Read/write/erase SPI NOR flash
1053 CONFIG_CMD_SHA1SUM * print sha1 memory digest
1054 (requires CONFIG_CMD_MEMORY)
1055 CONFIG_CMD_SOFTSWITCH * Soft switch setting command for BF60x
1056 CONFIG_CMD_SOURCE "source" command Support
1057 CONFIG_CMD_SPI * SPI serial bus support
1058 CONFIG_CMD_TFTPSRV * TFTP transfer in server mode
1059 CONFIG_CMD_TFTPPUT * TFTP put command (upload)
1060 CONFIG_CMD_TIME * run command and report execution time (ARM specific)
1061 CONFIG_CMD_TIMER * access to the system tick timer
1062 CONFIG_CMD_USB * USB support
1063 CONFIG_CMD_CDP * Cisco Discover Protocol support
1064 CONFIG_CMD_MFSL * Microblaze FSL support
1065 CONFIG_CMD_XIMG Load part of Multi Image
1066 CONFIG_CMD_UUID * Generate random UUID or GUID string
1068 EXAMPLE: If you want all functions except of network
1069 support you can write:
1071 #include "config_cmd_all.h"
1072 #undef CONFIG_CMD_NET
1075 fdt (flattened device tree) command: CONFIG_OF_LIBFDT
1077 Note: Don't enable the "icache" and "dcache" commands
1078 (configuration option CONFIG_CMD_CACHE) unless you know
1079 what you (and your U-Boot users) are doing. Data
1080 cache cannot be enabled on systems like the 8xx or
1081 8260 (where accesses to the IMMR region must be
1082 uncached), and it cannot be disabled on all other
1083 systems where we (mis-) use the data cache to hold an
1084 initial stack and some data.
1087 XXX - this list needs to get updated!
1089 - Regular expression support:
1091 If this variable is defined, U-Boot is linked against
1092 the SLRE (Super Light Regular Expression) library,
1093 which adds regex support to some commands, as for
1094 example "env grep" and "setexpr".
1098 If this variable is defined, U-Boot will use a device tree
1099 to configure its devices, instead of relying on statically
1100 compiled #defines in the board file. This option is
1101 experimental and only available on a few boards. The device
1102 tree is available in the global data as gd->fdt_blob.
1104 U-Boot needs to get its device tree from somewhere. This can
1105 be done using one of the two options below:
1108 If this variable is defined, U-Boot will embed a device tree
1109 binary in its image. This device tree file should be in the
1110 board directory and called <soc>-<board>.dts. The binary file
1111 is then picked up in board_init_f() and made available through
1112 the global data structure as gd->blob.
1115 If this variable is defined, U-Boot will build a device tree
1116 binary. It will be called u-boot.dtb. Architecture-specific
1117 code will locate it at run-time. Generally this works by:
1119 cat u-boot.bin u-boot.dtb >image.bin
1121 and in fact, U-Boot does this for you, creating a file called
1122 u-boot-dtb.bin which is useful in the common case. You can
1123 still use the individual files if you need something more
1128 If this variable is defined, it enables watchdog
1129 support for the SoC. There must be support in the SoC
1130 specific code for a watchdog. For the 8xx and 8260
1131 CPUs, the SIU Watchdog feature is enabled in the SYPCR
1132 register. When supported for a specific SoC is
1133 available, then no further board specific code should
1134 be needed to use it.
1137 When using a watchdog circuitry external to the used
1138 SoC, then define this variable and provide board
1139 specific code for the "hw_watchdog_reset" function.
1142 CONFIG_VERSION_VARIABLE
1143 If this variable is defined, an environment variable
1144 named "ver" is created by U-Boot showing the U-Boot
1145 version as printed by the "version" command.
1146 Any change to this variable will be reverted at the
1151 When CONFIG_CMD_DATE is selected, the type of the RTC
1152 has to be selected, too. Define exactly one of the
1155 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx
1156 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC
1157 CONFIG_RTC_MC13XXX - use MC13783 or MC13892 RTC
1158 CONFIG_RTC_MC146818 - use MC146818 RTC
1159 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC
1160 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC
1161 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC
1162 CONFIG_RTC_DS1339 - use Maxim, Inc. DS1339 RTC
1163 CONFIG_RTC_DS164x - use Dallas DS164x RTC
1164 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC
1165 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC
1166 CONFIG_SYS_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337
1167 CONFIG_SYS_RV3029_TCR - enable trickle charger on
1170 Note that if the RTC uses I2C, then the I2C interface
1171 must also be configured. See I2C Support, below.
1174 CONFIG_PCA953X - use NXP's PCA953X series I2C GPIO
1176 The CONFIG_SYS_I2C_PCA953X_WIDTH option specifies a list of
1177 chip-ngpio pairs that tell the PCA953X driver the number of
1178 pins supported by a particular chip.
1180 Note that if the GPIO device uses I2C, then the I2C interface
1181 must also be configured. See I2C Support, below.
1184 When CONFIG_IO_TRACE is selected, U-Boot intercepts all I/O
1185 accesses and can checksum them or write a list of them out
1186 to memory. See the 'iotrace' command for details. This is
1187 useful for testing device drivers since it can confirm that
1188 the driver behaves the same way before and after a code
1189 change. Currently this is supported on sandbox and arm. To
1190 add support for your architecture, add '#include <iotrace.h>'
1191 to the bottom of arch/<arch>/include/asm/io.h and test.
1193 Example output from the 'iotrace stats' command is below.
1194 Note that if the trace buffer is exhausted, the checksum will
1195 still continue to operate.
1198 Start: 10000000 (buffer start address)
1199 Size: 00010000 (buffer size)
1200 Offset: 00000120 (current buffer offset)
1201 Output: 10000120 (start + offset)
1202 Count: 00000018 (number of trace records)
1203 CRC32: 9526fb66 (CRC32 of all trace records)
1205 - Timestamp Support:
1207 When CONFIG_TIMESTAMP is selected, the timestamp
1208 (date and time) of an image is printed by image
1209 commands like bootm or iminfo. This option is
1210 automatically enabled when you select CONFIG_CMD_DATE .
1212 - Partition Labels (disklabels) Supported:
1213 Zero or more of the following:
1214 CONFIG_MAC_PARTITION Apple's MacOS partition table.
1215 CONFIG_DOS_PARTITION MS Dos partition table, traditional on the
1216 Intel architecture, USB sticks, etc.
1217 CONFIG_ISO_PARTITION ISO partition table, used on CDROM etc.
1218 CONFIG_EFI_PARTITION GPT partition table, common when EFI is the
1219 bootloader. Note 2TB partition limit; see
1221 CONFIG_MTD_PARTITIONS Memory Technology Device partition table.
1223 If IDE or SCSI support is enabled (CONFIG_CMD_IDE or
1224 CONFIG_CMD_SCSI) you must configure support for at
1225 least one non-MTD partition type as well.
1228 CONFIG_IDE_RESET_ROUTINE - this is defined in several
1229 board configurations files but used nowhere!
1231 CONFIG_IDE_RESET - is this is defined, IDE Reset will
1232 be performed by calling the function
1233 ide_set_reset(int reset)
1234 which has to be defined in a board specific file
1239 Set this to enable ATAPI support.
1244 Set this to enable support for disks larger than 137GB
1245 Also look at CONFIG_SYS_64BIT_LBA.
1246 Whithout these , LBA48 support uses 32bit variables and will 'only'
1247 support disks up to 2.1TB.
1249 CONFIG_SYS_64BIT_LBA:
1250 When enabled, makes the IDE subsystem use 64bit sector addresses.
1254 At the moment only there is only support for the
1255 SYM53C8XX SCSI controller; define
1256 CONFIG_SCSI_SYM53C8XX to enable it.
1258 CONFIG_SYS_SCSI_MAX_LUN [8], CONFIG_SYS_SCSI_MAX_SCSI_ID [7] and
1259 CONFIG_SYS_SCSI_MAX_DEVICE [CONFIG_SYS_SCSI_MAX_SCSI_ID *
1260 CONFIG_SYS_SCSI_MAX_LUN] can be adjusted to define the
1261 maximum numbers of LUNs, SCSI ID's and target
1263 CONFIG_SYS_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz)
1265 The environment variable 'scsidevs' is set to the number of
1266 SCSI devices found during the last scan.
1268 - NETWORK Support (PCI):
1270 Support for Intel 8254x/8257x gigabit chips.
1273 Utility code for direct access to the SPI bus on Intel 8257x.
1274 This does not do anything useful unless you set at least one
1275 of CONFIG_CMD_E1000 or CONFIG_E1000_SPI_GENERIC.
1277 CONFIG_E1000_SPI_GENERIC
1278 Allow generic access to the SPI bus on the Intel 8257x, for
1279 example with the "sspi" command.
1282 Management command for E1000 devices. When used on devices
1283 with SPI support you can reprogram the EEPROM from U-Boot.
1285 CONFIG_E1000_FALLBACK_MAC
1286 default MAC for empty EEPROM after production.
1289 Support for Intel 82557/82559/82559ER chips.
1290 Optional CONFIG_EEPRO100_SROM_WRITE enables EEPROM
1291 write routine for first time initialisation.
1294 Support for Digital 2114x chips.
1295 Optional CONFIG_TULIP_SELECT_MEDIA for board specific
1296 modem chip initialisation (KS8761/QS6611).
1299 Support for National dp83815 chips.
1302 Support for National dp8382[01] gigabit chips.
1304 - NETWORK Support (other):
1306 CONFIG_DRIVER_AT91EMAC
1307 Support for AT91RM9200 EMAC.
1310 Define this to use reduced MII inteface
1312 CONFIG_DRIVER_AT91EMAC_QUIET
1313 If this defined, the driver is quiet.
1314 The driver doen't show link status messages.
1316 CONFIG_CALXEDA_XGMAC
1317 Support for the Calxeda XGMAC device
1320 Support for SMSC's LAN91C96 chips.
1322 CONFIG_LAN91C96_BASE
1323 Define this to hold the physical address
1324 of the LAN91C96's I/O space
1326 CONFIG_LAN91C96_USE_32_BIT
1327 Define this to enable 32 bit addressing
1330 Support for SMSC's LAN91C111 chip
1332 CONFIG_SMC91111_BASE
1333 Define this to hold the physical address
1334 of the device (I/O space)
1336 CONFIG_SMC_USE_32_BIT
1337 Define this if data bus is 32 bits
1339 CONFIG_SMC_USE_IOFUNCS
1340 Define this to use i/o functions instead of macros
1341 (some hardware wont work with macros)
1343 CONFIG_DRIVER_TI_EMAC
1344 Support for davinci emac
1346 CONFIG_SYS_DAVINCI_EMAC_PHY_COUNT
1347 Define this if you have more then 3 PHYs.
1350 Support for Faraday's FTGMAC100 Gigabit SoC Ethernet
1352 CONFIG_FTGMAC100_EGIGA
1353 Define this to use GE link update with gigabit PHY.
1354 Define this if FTGMAC100 is connected to gigabit PHY.
1355 If your system has 10/100 PHY only, it might not occur
1356 wrong behavior. Because PHY usually return timeout or
1357 useless data when polling gigabit status and gigabit
1358 control registers. This behavior won't affect the
1359 correctnessof 10/100 link speed update.
1362 Support for SMSC's LAN911x and LAN921x chips
1365 Define this to hold the physical address
1366 of the device (I/O space)
1368 CONFIG_SMC911X_32_BIT
1369 Define this if data bus is 32 bits
1371 CONFIG_SMC911X_16_BIT
1372 Define this if data bus is 16 bits. If your processor
1373 automatically converts one 32 bit word to two 16 bit
1374 words you may also try CONFIG_SMC911X_32_BIT.
1377 Support for Renesas on-chip Ethernet controller
1379 CONFIG_SH_ETHER_USE_PORT
1380 Define the number of ports to be used
1382 CONFIG_SH_ETHER_PHY_ADDR
1383 Define the ETH PHY's address
1385 CONFIG_SH_ETHER_CACHE_WRITEBACK
1386 If this option is set, the driver enables cache flush.
1390 Support for PWM modul on the imx6.
1394 Support TPM devices.
1397 Support for i2c bus TPM devices. Only one device
1398 per system is supported at this time.
1400 CONFIG_TPM_TIS_I2C_BUS_NUMBER
1401 Define the the i2c bus number for the TPM device
1403 CONFIG_TPM_TIS_I2C_SLAVE_ADDRESS
1404 Define the TPM's address on the i2c bus
1406 CONFIG_TPM_TIS_I2C_BURST_LIMITATION
1407 Define the burst count bytes upper limit
1409 CONFIG_TPM_ATMEL_TWI
1410 Support for Atmel TWI TPM device. Requires I2C support.
1413 Support for generic parallel port TPM devices. Only one device
1414 per system is supported at this time.
1416 CONFIG_TPM_TIS_BASE_ADDRESS
1417 Base address where the generic TPM device is mapped
1418 to. Contemporary x86 systems usually map it at
1422 Add tpm monitor functions.
1423 Requires CONFIG_TPM. If CONFIG_TPM_AUTH_SESSIONS is set, also
1424 provides monitor access to authorized functions.
1427 Define this to enable the TPM support library which provides
1428 functional interfaces to some TPM commands.
1429 Requires support for a TPM device.
1431 CONFIG_TPM_AUTH_SESSIONS
1432 Define this to enable authorized functions in the TPM library.
1433 Requires CONFIG_TPM and CONFIG_SHA1.
1436 At the moment only the UHCI host controller is
1437 supported (PIP405, MIP405, MPC5200); define
1438 CONFIG_USB_UHCI to enable it.
1439 define CONFIG_USB_KEYBOARD to enable the USB Keyboard
1440 and define CONFIG_USB_STORAGE to enable the USB
1443 Supported are USB Keyboards and USB Floppy drives
1445 MPC5200 USB requires additional defines:
1447 for 528 MHz Clock: 0x0001bbbb
1451 for differential drivers: 0x00001000
1452 for single ended drivers: 0x00005000
1453 for differential drivers on PSC3: 0x00000100
1454 for single ended drivers on PSC3: 0x00004100
1455 CONFIG_SYS_USB_EVENT_POLL
1456 May be defined to allow interrupt polling
1457 instead of using asynchronous interrupts
1459 CONFIG_USB_EHCI_TXFIFO_THRESH enables setting of the
1460 txfilltuning field in the EHCI controller on reset.
1463 Define the below if you wish to use the USB console.
1464 Once firmware is rebuilt from a serial console issue the
1465 command "setenv stdin usbtty; setenv stdout usbtty" and
1466 attach your USB cable. The Unix command "dmesg" should print
1467 it has found a new device. The environment variable usbtty
1468 can be set to gserial or cdc_acm to enable your device to
1469 appear to a USB host as a Linux gserial device or a
1470 Common Device Class Abstract Control Model serial device.
1471 If you select usbtty = gserial you should be able to enumerate
1473 # modprobe usbserial vendor=0xVendorID product=0xProductID
1474 else if using cdc_acm, simply setting the environment
1475 variable usbtty to be cdc_acm should suffice. The following
1476 might be defined in YourBoardName.h
1479 Define this to build a UDC device
1482 Define this to have a tty type of device available to
1483 talk to the UDC device
1486 Define this to enable the high speed support for usb
1487 device and usbtty. If this feature is enabled, a routine
1488 int is_usbd_high_speed(void)
1489 also needs to be defined by the driver to dynamically poll
1490 whether the enumeration has succeded at high speed or full
1493 CONFIG_SYS_CONSOLE_IS_IN_ENV
1494 Define this if you want stdin, stdout &/or stderr to
1498 CONFIG_SYS_USB_EXTC_CLK 0xBLAH
1499 Derive USB clock from external clock "blah"
1500 - CONFIG_SYS_USB_EXTC_CLK 0x02
1502 CONFIG_SYS_USB_BRG_CLK 0xBLAH
1503 Derive USB clock from brgclk
1504 - CONFIG_SYS_USB_BRG_CLK 0x04
1506 If you have a USB-IF assigned VendorID then you may wish to
1507 define your own vendor specific values either in BoardName.h
1508 or directly in usbd_vendor_info.h. If you don't define
1509 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME,
1510 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot
1511 should pretend to be a Linux device to it's target host.
1513 CONFIG_USBD_MANUFACTURER
1514 Define this string as the name of your company for
1515 - CONFIG_USBD_MANUFACTURER "my company"
1517 CONFIG_USBD_PRODUCT_NAME
1518 Define this string as the name of your product
1519 - CONFIG_USBD_PRODUCT_NAME "acme usb device"
1521 CONFIG_USBD_VENDORID
1522 Define this as your assigned Vendor ID from the USB
1523 Implementors Forum. This *must* be a genuine Vendor ID
1524 to avoid polluting the USB namespace.
1525 - CONFIG_USBD_VENDORID 0xFFFF
1527 CONFIG_USBD_PRODUCTID
1528 Define this as the unique Product ID
1530 - CONFIG_USBD_PRODUCTID 0xFFFF
1532 - ULPI Layer Support:
1533 The ULPI (UTMI Low Pin (count) Interface) PHYs are supported via
1534 the generic ULPI layer. The generic layer accesses the ULPI PHY
1535 via the platform viewport, so you need both the genric layer and
1536 the viewport enabled. Currently only Chipidea/ARC based
1537 viewport is supported.
1538 To enable the ULPI layer support, define CONFIG_USB_ULPI and
1539 CONFIG_USB_ULPI_VIEWPORT in your board configuration file.
1540 If your ULPI phy needs a different reference clock than the
1541 standard 24 MHz then you have to define CONFIG_ULPI_REF_CLK to
1542 the appropriate value in Hz.
1545 The MMC controller on the Intel PXA is supported. To
1546 enable this define CONFIG_MMC. The MMC can be
1547 accessed from the boot prompt by mapping the device
1548 to physical memory similar to flash. Command line is
1549 enabled with CONFIG_CMD_MMC. The MMC driver also works with
1550 the FAT fs. This is enabled with CONFIG_CMD_FAT.
1553 Support for Renesas on-chip MMCIF controller
1555 CONFIG_SH_MMCIF_ADDR
1556 Define the base address of MMCIF registers
1559 Define the clock frequency for MMCIF
1562 Enable the generic MMC driver
1564 CONFIG_SUPPORT_EMMC_BOOT
1565 Enable some additional features of the eMMC boot partitions.
1567 CONFIG_SUPPORT_EMMC_RPMB
1568 Enable the commands for reading, writing and programming the
1569 key for the Replay Protection Memory Block partition in eMMC.
1571 - USB Device Firmware Update (DFU) class support:
1573 This enables the USB portion of the DFU USB class
1576 This enables the command "dfu" which is used to have
1577 U-Boot create a DFU class device via USB. This command
1578 requires that the "dfu_alt_info" environment variable be
1579 set and define the alt settings to expose to the host.
1582 This enables support for exposing (e)MMC devices via DFU.
1585 This enables support for exposing NAND devices via DFU.
1588 This enables support for exposing RAM via DFU.
1589 Note: DFU spec refer to non-volatile memory usage, but
1590 allow usages beyond the scope of spec - here RAM usage,
1591 one that would help mostly the developer.
1593 CONFIG_SYS_DFU_DATA_BUF_SIZE
1594 Dfu transfer uses a buffer before writing data to the
1595 raw storage device. Make the size (in bytes) of this buffer
1596 configurable. The size of this buffer is also configurable
1597 through the "dfu_bufsiz" environment variable.
1599 CONFIG_SYS_DFU_MAX_FILE_SIZE
1600 When updating files rather than the raw storage device,
1601 we use a static buffer to copy the file into and then write
1602 the buffer once we've been given the whole file. Define
1603 this to the maximum filesize (in bytes) for the buffer.
1604 Default is 4 MiB if undefined.
1606 DFU_DEFAULT_POLL_TIMEOUT
1607 Poll timeout [ms], is the timeout a device can send to the
1608 host. The host must wait for this timeout before sending
1609 a subsequent DFU_GET_STATUS request to the device.
1611 DFU_MANIFEST_POLL_TIMEOUT
1612 Poll timeout [ms], which the device sends to the host when
1613 entering dfuMANIFEST state. Host waits this timeout, before
1614 sending again an USB request to the device.
1616 - USB Device Android Fastboot support:
1618 This enables the command "fastboot" which enables the Android
1619 fastboot mode for the platform's USB device. Fastboot is a USB
1620 protocol for downloading images, flashing and device control
1621 used on Android devices.
1622 See doc/README.android-fastboot for more information.
1624 CONFIG_ANDROID_BOOT_IMAGE
1625 This enables support for booting images which use the Android
1626 image format header.
1628 CONFIG_USB_FASTBOOT_BUF_ADDR
1629 The fastboot protocol requires a large memory buffer for
1630 downloads. Define this to the starting RAM address to use for
1633 CONFIG_USB_FASTBOOT_BUF_SIZE
1634 The fastboot protocol requires a large memory buffer for
1635 downloads. This buffer should be as large as possible for a
1636 platform. Define this to the size available RAM for fastboot.
1638 CONFIG_FASTBOOT_FLASH
1639 The fastboot protocol includes a "flash" command for writing
1640 the downloaded image to a non-volatile storage device. Define
1641 this to enable the "fastboot flash" command.
1643 CONFIG_FASTBOOT_FLASH_MMC_DEV
1644 The fastboot "flash" command requires additional information
1645 regarding the non-volatile storage device. Define this to
1646 the eMMC device that fastboot should use to store the image.
1648 - Journaling Flash filesystem support:
1649 CONFIG_JFFS2_NAND, CONFIG_JFFS2_NAND_OFF, CONFIG_JFFS2_NAND_SIZE,
1650 CONFIG_JFFS2_NAND_DEV
1651 Define these for a default partition on a NAND device
1653 CONFIG_SYS_JFFS2_FIRST_SECTOR,
1654 CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS
1655 Define these for a default partition on a NOR device
1657 CONFIG_SYS_JFFS_CUSTOM_PART
1658 Define this to create an own partition. You have to provide a
1659 function struct part_info* jffs2_part_info(int part_num)
1661 If you define only one JFFS2 partition you may also want to
1662 #define CONFIG_SYS_JFFS_SINGLE_PART 1
1663 to disable the command chpart. This is the default when you
1664 have not defined a custom partition
1666 - FAT(File Allocation Table) filesystem write function support:
1669 Define this to enable support for saving memory data as a
1670 file in FAT formatted partition.
1672 This will also enable the command "fatwrite" enabling the
1673 user to write files to FAT.
1675 CBFS (Coreboot Filesystem) support
1678 Define this to enable support for reading from a Coreboot
1679 filesystem. Available commands are cbfsinit, cbfsinfo, cbfsls
1682 - FAT(File Allocation Table) filesystem cluster size:
1683 CONFIG_FS_FAT_MAX_CLUSTSIZE
1685 Define the max cluster size for fat operations else
1686 a default value of 65536 will be defined.
1691 Define this to enable standard (PC-Style) keyboard
1695 Standard PC keyboard driver with US (is default) and
1696 GERMAN key layout (switch via environment 'keymap=de') support.
1697 Export function i8042_kbd_init, i8042_tstc and i8042_getc
1698 for cfb_console. Supports cursor blinking.
1701 Enables a Chrome OS keyboard using the CROS_EC interface.
1702 This uses CROS_EC to communicate with a second microcontroller
1703 which provides key scans on request.
1708 Define this to enable video support (for output to
1711 CONFIG_VIDEO_CT69000
1713 Enable Chips & Technologies 69000 Video chip
1715 CONFIG_VIDEO_SMI_LYNXEM
1716 Enable Silicon Motion SMI 712/710/810 Video chip. The
1717 video output is selected via environment 'videoout'
1718 (1 = LCD and 2 = CRT). If videoout is undefined, CRT is
1721 For the CT69000 and SMI_LYNXEM drivers, videomode is
1722 selected via environment 'videomode'. Two different ways
1724 - "videomode=num" 'num' is a standard LiLo mode numbers.
1725 Following standard modes are supported (* is default):
1727 Colors 640x480 800x600 1024x768 1152x864 1280x1024
1728 -------------+---------------------------------------------
1729 8 bits | 0x301* 0x303 0x305 0x161 0x307
1730 15 bits | 0x310 0x313 0x316 0x162 0x319
1731 16 bits | 0x311 0x314 0x317 0x163 0x31A
1732 24 bits | 0x312 0x315 0x318 ? 0x31B
1733 -------------+---------------------------------------------
1734 (i.e. setenv videomode 317; saveenv; reset;)
1736 - "videomode=bootargs" all the video parameters are parsed
1737 from the bootargs. (See drivers/video/videomodes.c)
1740 CONFIG_VIDEO_SED13806
1741 Enable Epson SED13806 driver. This driver supports 8bpp
1742 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP
1743 or CONFIG_VIDEO_SED13806_16BPP
1746 Enable the Freescale DIU video driver. Reference boards for
1747 SOCs that have a DIU should define this macro to enable DIU
1748 support, and should also define these other macros:
1754 CONFIG_VIDEO_SW_CURSOR
1755 CONFIG_VGA_AS_SINGLE_DEVICE
1757 CONFIG_VIDEO_BMP_LOGO
1759 The DIU driver will look for the 'video-mode' environment
1760 variable, and if defined, enable the DIU as a console during
1761 boot. See the documentation file README.video for a
1762 description of this variable.
1766 Enable the VGA video / BIOS for x86. The alternative if you
1767 are using coreboot is to use the coreboot frame buffer
1774 Define this to enable a custom keyboard support.
1775 This simply calls drv_keyboard_init() which must be
1776 defined in your board-specific files.
1777 The only board using this so far is RBC823.
1779 - LCD Support: CONFIG_LCD
1781 Define this to enable LCD support (for output to LCD
1782 display); also select one of the supported displays
1783 by defining one of these:
1787 HITACHI TX09D70VM1CCA, 3.5", 240x320.
1789 CONFIG_NEC_NL6448AC33:
1791 NEC NL6448AC33-18. Active, color, single scan.
1793 CONFIG_NEC_NL6448BC20
1795 NEC NL6448BC20-08. 6.5", 640x480.
1796 Active, color, single scan.
1798 CONFIG_NEC_NL6448BC33_54
1800 NEC NL6448BC33-54. 10.4", 640x480.
1801 Active, color, single scan.
1805 Sharp 320x240. Active, color, single scan.
1806 It isn't 16x9, and I am not sure what it is.
1808 CONFIG_SHARP_LQ64D341
1810 Sharp LQ64D341 display, 640x480.
1811 Active, color, single scan.
1815 HLD1045 display, 640x480.
1816 Active, color, single scan.
1820 Optrex CBL50840-2 NF-FW 99 22 M5
1822 Hitachi LMG6912RPFC-00T
1826 320x240. Black & white.
1828 Normally display is black on white background; define
1829 CONFIG_SYS_WHITE_ON_BLACK to get it inverted.
1831 CONFIG_LCD_ALIGNMENT
1833 Normally the LCD is page-aligned (tyically 4KB). If this is
1834 defined then the LCD will be aligned to this value instead.
1835 For ARM it is sometimes useful to use MMU_SECTION_SIZE
1836 here, since it is cheaper to change data cache settings on
1837 a per-section basis.
1839 CONFIG_CONSOLE_SCROLL_LINES
1841 When the console need to be scrolled, this is the number of
1842 lines to scroll by. It defaults to 1. Increasing this makes
1843 the console jump but can help speed up operation when scrolling
1848 Support drawing of RLE8-compressed bitmaps on the LCD.
1852 Enables an 'i2c edid' command which can read EDID
1853 information over I2C from an attached LCD display.
1855 - Splash Screen Support: CONFIG_SPLASH_SCREEN
1857 If this option is set, the environment is checked for
1858 a variable "splashimage". If found, the usual display
1859 of logo, copyright and system information on the LCD
1860 is suppressed and the BMP image at the address
1861 specified in "splashimage" is loaded instead. The
1862 console is redirected to the "nulldev", too. This
1863 allows for a "silent" boot where a splash screen is
1864 loaded very quickly after power-on.
1866 CONFIG_SPLASHIMAGE_GUARD
1868 If this option is set, then U-Boot will prevent the environment
1869 variable "splashimage" from being set to a problematic address
1870 (see README.displaying-bmps).
1871 This option is useful for targets where, due to alignment
1872 restrictions, an improperly aligned BMP image will cause a data
1873 abort. If you think you will not have problems with unaligned
1874 accesses (for example because your toolchain prevents them)
1875 there is no need to set this option.
1877 CONFIG_SPLASH_SCREEN_ALIGN
1879 If this option is set the splash image can be freely positioned
1880 on the screen. Environment variable "splashpos" specifies the
1881 position as "x,y". If a positive number is given it is used as
1882 number of pixel from left/top. If a negative number is given it
1883 is used as number of pixel from right/bottom. You can also
1884 specify 'm' for centering the image.
1887 setenv splashpos m,m
1888 => image at center of screen
1890 setenv splashpos 30,20
1891 => image at x = 30 and y = 20
1893 setenv splashpos -10,m
1894 => vertically centered image
1895 at x = dspWidth - bmpWidth - 9
1897 - Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP
1899 If this option is set, additionally to standard BMP
1900 images, gzipped BMP images can be displayed via the
1901 splashscreen support or the bmp command.
1903 - Run length encoded BMP image (RLE8) support: CONFIG_VIDEO_BMP_RLE8
1905 If this option is set, 8-bit RLE compressed BMP images
1906 can be displayed via the splashscreen support or the
1909 - Do compresssing for memory range:
1912 If this option is set, it would use zlib deflate method
1913 to compress the specified memory at its best effort.
1915 - Compression support:
1918 Enabled by default to support gzip compressed images.
1922 If this option is set, support for bzip2 compressed
1923 images is included. If not, only uncompressed and gzip
1924 compressed images are supported.
1926 NOTE: the bzip2 algorithm requires a lot of RAM, so
1927 the malloc area (as defined by CONFIG_SYS_MALLOC_LEN) should
1932 If this option is set, support for lzma compressed
1935 Note: The LZMA algorithm adds between 2 and 4KB of code and it
1936 requires an amount of dynamic memory that is given by the
1939 (1846 + 768 << (lc + lp)) * sizeof(uint16)
1941 Where lc and lp stand for, respectively, Literal context bits
1942 and Literal pos bits.
1944 This value is upper-bounded by 14MB in the worst case. Anyway,
1945 for a ~4MB large kernel image, we have lc=3 and lp=0 for a
1946 total amount of (1846 + 768 << (3 + 0)) * 2 = ~41KB... that is
1947 a very small buffer.
1949 Use the lzmainfo tool to determinate the lc and lp values and
1950 then calculate the amount of needed dynamic memory (ensuring
1951 the appropriate CONFIG_SYS_MALLOC_LEN value).
1955 If this option is set, support for LZO compressed images
1961 The address of PHY on MII bus.
1963 CONFIG_PHY_CLOCK_FREQ (ppc4xx)
1965 The clock frequency of the MII bus
1969 If this option is set, support for speed/duplex
1970 detection of gigabit PHY is included.
1972 CONFIG_PHY_RESET_DELAY
1974 Some PHY like Intel LXT971A need extra delay after
1975 reset before any MII register access is possible.
1976 For such PHY, set this option to the usec delay
1977 required. (minimum 300usec for LXT971A)
1979 CONFIG_PHY_CMD_DELAY (ppc4xx)
1981 Some PHY like Intel LXT971A need extra delay after
1982 command issued before MII status register can be read
1992 Define a default value for Ethernet address to use
1993 for the respective Ethernet interface, in case this
1994 is not determined automatically.
1999 Define a default value for the IP address to use for
2000 the default Ethernet interface, in case this is not
2001 determined through e.g. bootp.
2002 (Environment variable "ipaddr")
2004 - Server IP address:
2007 Defines a default value for the IP address of a TFTP
2008 server to contact when using the "tftboot" command.
2009 (Environment variable "serverip")
2011 CONFIG_KEEP_SERVERADDR
2013 Keeps the server's MAC address, in the env 'serveraddr'
2014 for passing to bootargs (like Linux's netconsole option)
2016 - Gateway IP address:
2019 Defines a default value for the IP address of the
2020 default router where packets to other networks are
2022 (Environment variable "gatewayip")
2027 Defines a default value for the subnet mask (or
2028 routing prefix) which is used to determine if an IP
2029 address belongs to the local subnet or needs to be
2030 forwarded through a router.
2031 (Environment variable "netmask")
2033 - Multicast TFTP Mode:
2036 Defines whether you want to support multicast TFTP as per
2037 rfc-2090; for example to work with atftp. Lets lots of targets
2038 tftp down the same boot image concurrently. Note: the Ethernet
2039 driver in use must provide a function: mcast() to join/leave a
2042 - BOOTP Recovery Mode:
2043 CONFIG_BOOTP_RANDOM_DELAY
2045 If you have many targets in a network that try to
2046 boot using BOOTP, you may want to avoid that all
2047 systems send out BOOTP requests at precisely the same
2048 moment (which would happen for instance at recovery
2049 from a power failure, when all systems will try to
2050 boot, thus flooding the BOOTP server. Defining
2051 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
2052 inserted before sending out BOOTP requests. The
2053 following delays are inserted then:
2055 1st BOOTP request: delay 0 ... 1 sec
2056 2nd BOOTP request: delay 0 ... 2 sec
2057 3rd BOOTP request: delay 0 ... 4 sec
2059 BOOTP requests: delay 0 ... 8 sec
2061 CONFIG_BOOTP_ID_CACHE_SIZE
2063 BOOTP packets are uniquely identified using a 32-bit ID. The
2064 server will copy the ID from client requests to responses and
2065 U-Boot will use this to determine if it is the destination of
2066 an incoming response. Some servers will check that addresses
2067 aren't in use before handing them out (usually using an ARP
2068 ping) and therefore take up to a few hundred milliseconds to
2069 respond. Network congestion may also influence the time it
2070 takes for a response to make it back to the client. If that
2071 time is too long, U-Boot will retransmit requests. In order
2072 to allow earlier responses to still be accepted after these
2073 retransmissions, U-Boot's BOOTP client keeps a small cache of
2074 IDs. The CONFIG_BOOTP_ID_CACHE_SIZE controls the size of this
2075 cache. The default is to keep IDs for up to four outstanding
2076 requests. Increasing this will allow U-Boot to accept offers
2077 from a BOOTP client in networks with unusually high latency.
2079 - DHCP Advanced Options:
2080 You can fine tune the DHCP functionality by defining
2081 CONFIG_BOOTP_* symbols:
2083 CONFIG_BOOTP_SUBNETMASK
2084 CONFIG_BOOTP_GATEWAY
2085 CONFIG_BOOTP_HOSTNAME
2086 CONFIG_BOOTP_NISDOMAIN
2087 CONFIG_BOOTP_BOOTPATH
2088 CONFIG_BOOTP_BOOTFILESIZE
2091 CONFIG_BOOTP_SEND_HOSTNAME
2092 CONFIG_BOOTP_NTPSERVER
2093 CONFIG_BOOTP_TIMEOFFSET
2094 CONFIG_BOOTP_VENDOREX
2095 CONFIG_BOOTP_MAY_FAIL
2097 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip
2098 environment variable, not the BOOTP server.
2100 CONFIG_BOOTP_MAY_FAIL - If the DHCP server is not found
2101 after the configured retry count, the call will fail
2102 instead of starting over. This can be used to fail over
2103 to Link-local IP address configuration if the DHCP server
2106 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS
2107 serverip from a DHCP server, it is possible that more
2108 than one DNS serverip is offered to the client.
2109 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS
2110 serverip will be stored in the additional environment
2111 variable "dnsip2". The first DNS serverip is always
2112 stored in the variable "dnsip", when CONFIG_BOOTP_DNS
2115 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable
2116 to do a dynamic update of a DNS server. To do this, they
2117 need the hostname of the DHCP requester.
2118 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content
2119 of the "hostname" environment variable is passed as
2120 option 12 to the DHCP server.
2122 CONFIG_BOOTP_DHCP_REQUEST_DELAY
2124 A 32bit value in microseconds for a delay between
2125 receiving a "DHCP Offer" and sending the "DHCP Request".
2126 This fixes a problem with certain DHCP servers that don't
2127 respond 100% of the time to a "DHCP request". E.g. On an
2128 AT91RM9200 processor running at 180MHz, this delay needed
2129 to be *at least* 15,000 usec before a Windows Server 2003
2130 DHCP server would reply 100% of the time. I recommend at
2131 least 50,000 usec to be safe. The alternative is to hope
2132 that one of the retries will be successful but note that
2133 the DHCP timeout and retry process takes a longer than
2136 - Link-local IP address negotiation:
2137 Negotiate with other link-local clients on the local network
2138 for an address that doesn't require explicit configuration.
2139 This is especially useful if a DHCP server cannot be guaranteed
2140 to exist in all environments that the device must operate.
2142 See doc/README.link-local for more information.
2145 CONFIG_CDP_DEVICE_ID
2147 The device id used in CDP trigger frames.
2149 CONFIG_CDP_DEVICE_ID_PREFIX
2151 A two character string which is prefixed to the MAC address
2156 A printf format string which contains the ascii name of
2157 the port. Normally is set to "eth%d" which sets
2158 eth0 for the first Ethernet, eth1 for the second etc.
2160 CONFIG_CDP_CAPABILITIES
2162 A 32bit integer which indicates the device capabilities;
2163 0x00000010 for a normal host which does not forwards.
2167 An ascii string containing the version of the software.
2171 An ascii string containing the name of the platform.
2175 A 32bit integer sent on the trigger.
2177 CONFIG_CDP_POWER_CONSUMPTION
2179 A 16bit integer containing the power consumption of the
2180 device in .1 of milliwatts.
2182 CONFIG_CDP_APPLIANCE_VLAN_TYPE
2184 A byte containing the id of the VLAN.
2186 - Status LED: CONFIG_STATUS_LED
2188 Several configurations allow to display the current
2189 status using a LED. For instance, the LED will blink
2190 fast while running U-Boot code, stop blinking as
2191 soon as a reply to a BOOTP request was received, and
2192 start blinking slow once the Linux kernel is running
2193 (supported by a status LED driver in the Linux
2194 kernel). Defining CONFIG_STATUS_LED enables this
2200 The status LED can be connected to a GPIO pin.
2201 In such cases, the gpio_led driver can be used as a
2202 status LED backend implementation. Define CONFIG_GPIO_LED
2203 to include the gpio_led driver in the U-Boot binary.
2205 CONFIG_GPIO_LED_INVERTED_TABLE
2206 Some GPIO connected LEDs may have inverted polarity in which
2207 case the GPIO high value corresponds to LED off state and
2208 GPIO low value corresponds to LED on state.
2209 In such cases CONFIG_GPIO_LED_INVERTED_TABLE may be defined
2210 with a list of GPIO LEDs that have inverted polarity.
2212 - CAN Support: CONFIG_CAN_DRIVER
2214 Defining CONFIG_CAN_DRIVER enables CAN driver support
2215 on those systems that support this (optional)
2216 feature, like the TQM8xxL modules.
2218 - I2C Support: CONFIG_SYS_I2C
2220 This enable the NEW i2c subsystem, and will allow you to use
2221 i2c commands at the u-boot command line (as long as you set
2222 CONFIG_CMD_I2C in CONFIG_COMMANDS) and communicate with i2c
2223 based realtime clock chips or other i2c devices. See
2224 common/cmd_i2c.c for a description of the command line
2227 ported i2c driver to the new framework:
2228 - drivers/i2c/soft_i2c.c:
2229 - activate first bus with CONFIG_SYS_I2C_SOFT define
2230 CONFIG_SYS_I2C_SOFT_SPEED and CONFIG_SYS_I2C_SOFT_SLAVE
2231 for defining speed and slave address
2232 - activate second bus with I2C_SOFT_DECLARATIONS2 define
2233 CONFIG_SYS_I2C_SOFT_SPEED_2 and CONFIG_SYS_I2C_SOFT_SLAVE_2
2234 for defining speed and slave address
2235 - activate third bus with I2C_SOFT_DECLARATIONS3 define
2236 CONFIG_SYS_I2C_SOFT_SPEED_3 and CONFIG_SYS_I2C_SOFT_SLAVE_3
2237 for defining speed and slave address
2238 - activate fourth bus with I2C_SOFT_DECLARATIONS4 define
2239 CONFIG_SYS_I2C_SOFT_SPEED_4 and CONFIG_SYS_I2C_SOFT_SLAVE_4
2240 for defining speed and slave address
2242 - drivers/i2c/fsl_i2c.c:
2243 - activate i2c driver with CONFIG_SYS_I2C_FSL
2244 define CONFIG_SYS_FSL_I2C_OFFSET for setting the register
2245 offset CONFIG_SYS_FSL_I2C_SPEED for the i2c speed and
2246 CONFIG_SYS_FSL_I2C_SLAVE for the slave addr of the first
2248 - If your board supports a second fsl i2c bus, define
2249 CONFIG_SYS_FSL_I2C2_OFFSET for the register offset
2250 CONFIG_SYS_FSL_I2C2_SPEED for the speed and
2251 CONFIG_SYS_FSL_I2C2_SLAVE for the slave address of the
2254 - drivers/i2c/tegra_i2c.c:
2255 - activate this driver with CONFIG_SYS_I2C_TEGRA
2256 - This driver adds 4 i2c buses with a fix speed from
2257 100000 and the slave addr 0!
2259 - drivers/i2c/ppc4xx_i2c.c
2260 - activate this driver with CONFIG_SYS_I2C_PPC4XX
2261 - CONFIG_SYS_I2C_PPC4XX_CH0 activate hardware channel 0
2262 - CONFIG_SYS_I2C_PPC4XX_CH1 activate hardware channel 1
2264 - drivers/i2c/i2c_mxc.c
2265 - activate this driver with CONFIG_SYS_I2C_MXC
2266 - define speed for bus 1 with CONFIG_SYS_MXC_I2C1_SPEED
2267 - define slave for bus 1 with CONFIG_SYS_MXC_I2C1_SLAVE
2268 - define speed for bus 2 with CONFIG_SYS_MXC_I2C2_SPEED
2269 - define slave for bus 2 with CONFIG_SYS_MXC_I2C2_SLAVE
2270 - define speed for bus 3 with CONFIG_SYS_MXC_I2C3_SPEED
2271 - define slave for bus 3 with CONFIG_SYS_MXC_I2C3_SLAVE
2272 If thoses defines are not set, default value is 100000
2273 for speed, and 0 for slave.
2275 - drivers/i2c/rcar_i2c.c:
2276 - activate this driver with CONFIG_SYS_I2C_RCAR
2277 - This driver adds 4 i2c buses
2279 - CONFIG_SYS_RCAR_I2C0_BASE for setting the register channel 0
2280 - CONFIG_SYS_RCAR_I2C0_SPEED for for the speed channel 0
2281 - CONFIG_SYS_RCAR_I2C1_BASE for setting the register channel 1
2282 - CONFIG_SYS_RCAR_I2C1_SPEED for for the speed channel 1
2283 - CONFIG_SYS_RCAR_I2C2_BASE for setting the register channel 2
2284 - CONFIG_SYS_RCAR_I2C2_SPEED for for the speed channel 2
2285 - CONFIG_SYS_RCAR_I2C3_BASE for setting the register channel 3
2286 - CONFIG_SYS_RCAR_I2C3_SPEED for for the speed channel 3
2287 - CONFIF_SYS_RCAR_I2C_NUM_CONTROLLERS for number of i2c buses
2289 - drivers/i2c/sh_i2c.c:
2290 - activate this driver with CONFIG_SYS_I2C_SH
2291 - This driver adds from 2 to 5 i2c buses
2293 - CONFIG_SYS_I2C_SH_BASE0 for setting the register channel 0
2294 - CONFIG_SYS_I2C_SH_SPEED0 for for the speed channel 0
2295 - CONFIG_SYS_I2C_SH_BASE1 for setting the register channel 1
2296 - CONFIG_SYS_I2C_SH_SPEED1 for for the speed channel 1
2297 - CONFIG_SYS_I2C_SH_BASE2 for setting the register channel 2
2298 - CONFIG_SYS_I2C_SH_SPEED2 for for the speed channel 2
2299 - CONFIG_SYS_I2C_SH_BASE3 for setting the register channel 3
2300 - CONFIG_SYS_I2C_SH_SPEED3 for for the speed channel 3
2301 - CONFIG_SYS_I2C_SH_BASE4 for setting the register channel 4
2302 - CONFIG_SYS_I2C_SH_SPEED4 for for the speed channel 4
2303 - CONFIG_SYS_I2C_SH_BASE5 for setting the register channel 5
2304 - CONFIG_SYS_I2C_SH_SPEED5 for for the speed channel 5
2305 - CONFIF_SYS_I2C_SH_NUM_CONTROLLERS for nummber of i2c buses
2307 - drivers/i2c/omap24xx_i2c.c
2308 - activate this driver with CONFIG_SYS_I2C_OMAP24XX
2309 - CONFIG_SYS_OMAP24_I2C_SPEED speed channel 0
2310 - CONFIG_SYS_OMAP24_I2C_SLAVE slave addr channel 0
2311 - CONFIG_SYS_OMAP24_I2C_SPEED1 speed channel 1
2312 - CONFIG_SYS_OMAP24_I2C_SLAVE1 slave addr channel 1
2313 - CONFIG_SYS_OMAP24_I2C_SPEED2 speed channel 2
2314 - CONFIG_SYS_OMAP24_I2C_SLAVE2 slave addr channel 2
2315 - CONFIG_SYS_OMAP24_I2C_SPEED3 speed channel 3
2316 - CONFIG_SYS_OMAP24_I2C_SLAVE3 slave addr channel 3
2317 - CONFIG_SYS_OMAP24_I2C_SPEED4 speed channel 4
2318 - CONFIG_SYS_OMAP24_I2C_SLAVE4 slave addr channel 4
2320 - drivers/i2c/zynq_i2c.c
2321 - activate this driver with CONFIG_SYS_I2C_ZYNQ
2322 - set CONFIG_SYS_I2C_ZYNQ_SPEED for speed setting
2323 - set CONFIG_SYS_I2C_ZYNQ_SLAVE for slave addr
2325 - drivers/i2c/s3c24x0_i2c.c:
2326 - activate this driver with CONFIG_SYS_I2C_S3C24X0
2327 - This driver adds i2c buses (11 for Exynos5250, Exynos5420
2328 9 i2c buses for Exynos4 and 1 for S3C24X0 SoCs from Samsung)
2329 with a fix speed from 100000 and the slave addr 0!
2331 - drivers/i2c/ihs_i2c.c
2332 - activate this driver with CONFIG_SYS_I2C_IHS
2333 - CONFIG_SYS_I2C_IHS_CH0 activate hardware channel 0
2334 - CONFIG_SYS_I2C_IHS_SPEED_0 speed channel 0
2335 - CONFIG_SYS_I2C_IHS_SLAVE_0 slave addr channel 0
2336 - CONFIG_SYS_I2C_IHS_CH1 activate hardware channel 1
2337 - CONFIG_SYS_I2C_IHS_SPEED_1 speed channel 1
2338 - CONFIG_SYS_I2C_IHS_SLAVE_1 slave addr channel 1
2339 - CONFIG_SYS_I2C_IHS_CH2 activate hardware channel 2
2340 - CONFIG_SYS_I2C_IHS_SPEED_2 speed channel 2
2341 - CONFIG_SYS_I2C_IHS_SLAVE_2 slave addr channel 2
2342 - CONFIG_SYS_I2C_IHS_CH3 activate hardware channel 3
2343 - CONFIG_SYS_I2C_IHS_SPEED_3 speed channel 3
2344 - CONFIG_SYS_I2C_IHS_SLAVE_3 slave addr channel 3
2348 CONFIG_SYS_NUM_I2C_BUSES
2349 Hold the number of i2c busses you want to use. If you
2350 don't use/have i2c muxes on your i2c bus, this
2351 is equal to CONFIG_SYS_NUM_I2C_ADAPTERS, and you can
2354 CONFIG_SYS_I2C_DIRECT_BUS
2355 define this, if you don't use i2c muxes on your hardware.
2356 if CONFIG_SYS_I2C_MAX_HOPS is not defined or == 0 you can
2359 CONFIG_SYS_I2C_MAX_HOPS
2360 define how many muxes are maximal consecutively connected
2361 on one i2c bus. If you not use i2c muxes, omit this
2364 CONFIG_SYS_I2C_BUSES
2365 hold a list of busses you want to use, only used if
2366 CONFIG_SYS_I2C_DIRECT_BUS is not defined, for example
2367 a board with CONFIG_SYS_I2C_MAX_HOPS = 1 and
2368 CONFIG_SYS_NUM_I2C_BUSES = 9:
2370 CONFIG_SYS_I2C_BUSES {{0, {I2C_NULL_HOP}}, \
2371 {0, {{I2C_MUX_PCA9547, 0x70, 1}}}, \
2372 {0, {{I2C_MUX_PCA9547, 0x70, 2}}}, \
2373 {0, {{I2C_MUX_PCA9547, 0x70, 3}}}, \
2374 {0, {{I2C_MUX_PCA9547, 0x70, 4}}}, \
2375 {0, {{I2C_MUX_PCA9547, 0x70, 5}}}, \
2376 {1, {I2C_NULL_HOP}}, \
2377 {1, {{I2C_MUX_PCA9544, 0x72, 1}}}, \
2378 {1, {{I2C_MUX_PCA9544, 0x72, 2}}}, \
2382 bus 0 on adapter 0 without a mux
2383 bus 1 on adapter 0 with a PCA9547 on address 0x70 port 1
2384 bus 2 on adapter 0 with a PCA9547 on address 0x70 port 2
2385 bus 3 on adapter 0 with a PCA9547 on address 0x70 port 3
2386 bus 4 on adapter 0 with a PCA9547 on address 0x70 port 4
2387 bus 5 on adapter 0 with a PCA9547 on address 0x70 port 5
2388 bus 6 on adapter 1 without a mux
2389 bus 7 on adapter 1 with a PCA9544 on address 0x72 port 1
2390 bus 8 on adapter 1 with a PCA9544 on address 0x72 port 2
2392 If you do not have i2c muxes on your board, omit this define.
2394 - Legacy I2C Support: CONFIG_HARD_I2C
2396 NOTE: It is intended to move drivers to CONFIG_SYS_I2C which
2397 provides the following compelling advantages:
2399 - more than one i2c adapter is usable
2400 - approved multibus support
2401 - better i2c mux support
2403 ** Please consider updating your I2C driver now. **
2405 These enable legacy I2C serial bus commands. Defining
2406 CONFIG_HARD_I2C will include the appropriate I2C driver
2407 for the selected CPU.
2409 This will allow you to use i2c commands at the u-boot
2410 command line (as long as you set CONFIG_CMD_I2C in
2411 CONFIG_COMMANDS) and communicate with i2c based realtime
2412 clock chips. See common/cmd_i2c.c for a description of the
2413 command line interface.
2415 CONFIG_HARD_I2C selects a hardware I2C controller.
2417 There are several other quantities that must also be
2418 defined when you define CONFIG_HARD_I2C.
2420 In both cases you will need to define CONFIG_SYS_I2C_SPEED
2421 to be the frequency (in Hz) at which you wish your i2c bus
2422 to run and CONFIG_SYS_I2C_SLAVE to be the address of this node (ie
2423 the CPU's i2c node address).
2425 Now, the u-boot i2c code for the mpc8xx
2426 (arch/powerpc/cpu/mpc8xx/i2c.c) sets the CPU up as a master node
2427 and so its address should therefore be cleared to 0 (See,
2428 eg, MPC823e User's Manual p.16-473). So, set
2429 CONFIG_SYS_I2C_SLAVE to 0.
2431 CONFIG_SYS_I2C_INIT_MPC5XXX
2433 When a board is reset during an i2c bus transfer
2434 chips might think that the current transfer is still
2435 in progress. Reset the slave devices by sending start
2436 commands until the slave device responds.
2438 That's all that's required for CONFIG_HARD_I2C.
2440 If you use the software i2c interface (CONFIG_SYS_I2C_SOFT)
2441 then the following macros need to be defined (examples are
2442 from include/configs/lwmon.h):
2446 (Optional). Any commands necessary to enable the I2C
2447 controller or configure ports.
2449 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
2453 (Only for MPC8260 CPU). The I/O port to use (the code
2454 assumes both bits are on the same port). Valid values
2455 are 0..3 for ports A..D.
2459 The code necessary to make the I2C data line active
2460 (driven). If the data line is open collector, this
2463 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
2467 The code necessary to make the I2C data line tri-stated
2468 (inactive). If the data line is open collector, this
2471 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
2475 Code that returns true if the I2C data line is high,
2478 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
2482 If <bit> is true, sets the I2C data line high. If it
2483 is false, it clears it (low).
2485 eg: #define I2C_SDA(bit) \
2486 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
2487 else immr->im_cpm.cp_pbdat &= ~PB_SDA
2491 If <bit> is true, sets the I2C clock line high. If it
2492 is false, it clears it (low).
2494 eg: #define I2C_SCL(bit) \
2495 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
2496 else immr->im_cpm.cp_pbdat &= ~PB_SCL
2500 This delay is invoked four times per clock cycle so this
2501 controls the rate of data transfer. The data rate thus
2502 is 1 / (I2C_DELAY * 4). Often defined to be something
2505 #define I2C_DELAY udelay(2)
2507 CONFIG_SOFT_I2C_GPIO_SCL / CONFIG_SOFT_I2C_GPIO_SDA
2509 If your arch supports the generic GPIO framework (asm/gpio.h),
2510 then you may alternatively define the two GPIOs that are to be
2511 used as SCL / SDA. Any of the previous I2C_xxx macros will
2512 have GPIO-based defaults assigned to them as appropriate.
2514 You should define these to the GPIO value as given directly to
2515 the generic GPIO functions.
2517 CONFIG_SYS_I2C_INIT_BOARD
2519 When a board is reset during an i2c bus transfer
2520 chips might think that the current transfer is still
2521 in progress. On some boards it is possible to access
2522 the i2c SCLK line directly, either by using the
2523 processor pin as a GPIO or by having a second pin
2524 connected to the bus. If this option is defined a
2525 custom i2c_init_board() routine in boards/xxx/board.c
2526 is run early in the boot sequence.
2528 CONFIG_SYS_I2C_BOARD_LATE_INIT
2530 An alternative to CONFIG_SYS_I2C_INIT_BOARD. If this option is
2531 defined a custom i2c_board_late_init() routine in
2532 boards/xxx/board.c is run AFTER the operations in i2c_init()
2533 is completed. This callpoint can be used to unreset i2c bus
2534 using CPU i2c controller register accesses for CPUs whose i2c
2535 controller provide such a method. It is called at the end of
2536 i2c_init() to allow i2c_init operations to setup the i2c bus
2537 controller on the CPU (e.g. setting bus speed & slave address).
2539 CONFIG_I2CFAST (PPC405GP|PPC405EP only)
2541 This option enables configuration of bi_iic_fast[] flags
2542 in u-boot bd_info structure based on u-boot environment
2543 variable "i2cfast". (see also i2cfast)
2545 CONFIG_I2C_MULTI_BUS
2547 This option allows the use of multiple I2C buses, each of which
2548 must have a controller. At any point in time, only one bus is
2549 active. To switch to a different bus, use the 'i2c dev' command.
2550 Note that bus numbering is zero-based.
2552 CONFIG_SYS_I2C_NOPROBES
2554 This option specifies a list of I2C devices that will be skipped
2555 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS
2556 is set, specify a list of bus-device pairs. Otherwise, specify
2557 a 1D array of device addresses
2560 #undef CONFIG_I2C_MULTI_BUS
2561 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68}
2563 will skip addresses 0x50 and 0x68 on a board with one I2C bus
2565 #define CONFIG_I2C_MULTI_BUS
2566 #define CONFIG_SYS_I2C_MULTI_NOPROBES {{0,0x50},{0,0x68},{1,0x54}}
2568 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1
2570 CONFIG_SYS_SPD_BUS_NUM
2572 If defined, then this indicates the I2C bus number for DDR SPD.
2573 If not defined, then U-Boot assumes that SPD is on I2C bus 0.
2575 CONFIG_SYS_RTC_BUS_NUM
2577 If defined, then this indicates the I2C bus number for the RTC.
2578 If not defined, then U-Boot assumes that RTC is on I2C bus 0.
2580 CONFIG_SYS_DTT_BUS_NUM
2582 If defined, then this indicates the I2C bus number for the DTT.
2583 If not defined, then U-Boot assumes that DTT is on I2C bus 0.
2585 CONFIG_SYS_I2C_DTT_ADDR:
2587 If defined, specifies the I2C address of the DTT device.
2588 If not defined, then U-Boot uses predefined value for
2589 specified DTT device.
2591 CONFIG_SOFT_I2C_READ_REPEATED_START
2593 defining this will force the i2c_read() function in
2594 the soft_i2c driver to perform an I2C repeated start
2595 between writing the address pointer and reading the
2596 data. If this define is omitted the default behaviour
2597 of doing a stop-start sequence will be used. Most I2C
2598 devices can use either method, but some require one or
2601 - SPI Support: CONFIG_SPI
2603 Enables SPI driver (so far only tested with
2604 SPI EEPROM, also an instance works with Crystal A/D and
2605 D/As on the SACSng board)
2609 Enables the driver for SPI controller on SuperH. Currently
2610 only SH7757 is supported.
2614 Enables extended (16-bit) SPI EEPROM addressing.
2615 (symmetrical to CONFIG_I2C_X)
2619 Enables a software (bit-bang) SPI driver rather than
2620 using hardware support. This is a general purpose
2621 driver that only requires three general I/O port pins
2622 (two outputs, one input) to function. If this is
2623 defined, the board configuration must define several
2624 SPI configuration items (port pins to use, etc). For
2625 an example, see include/configs/sacsng.h.
2629 Enables a hardware SPI driver for general-purpose reads
2630 and writes. As with CONFIG_SOFT_SPI, the board configuration
2631 must define a list of chip-select function pointers.
2632 Currently supported on some MPC8xxx processors. For an
2633 example, see include/configs/mpc8349emds.h.
2637 Enables the driver for the SPI controllers on i.MX and MXC
2638 SoCs. Currently i.MX31/35/51 are supported.
2640 CONFIG_SYS_SPI_MXC_WAIT
2641 Timeout for waiting until spi transfer completed.
2642 default: (CONFIG_SYS_HZ/100) /* 10 ms */
2644 - FPGA Support: CONFIG_FPGA
2646 Enables FPGA subsystem.
2648 CONFIG_FPGA_<vendor>
2650 Enables support for specific chip vendors.
2653 CONFIG_FPGA_<family>
2655 Enables support for FPGA family.
2656 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX)
2660 Specify the number of FPGA devices to support.
2662 CONFIG_CMD_FPGA_LOADMK
2664 Enable support for fpga loadmk command
2666 CONFIG_CMD_FPGA_LOADP
2668 Enable support for fpga loadp command - load partial bitstream
2670 CONFIG_CMD_FPGA_LOADBP
2672 Enable support for fpga loadbp command - load partial bitstream
2675 CONFIG_SYS_FPGA_PROG_FEEDBACK
2677 Enable printing of hash marks during FPGA configuration.
2679 CONFIG_SYS_FPGA_CHECK_BUSY
2681 Enable checks on FPGA configuration interface busy
2682 status by the configuration function. This option
2683 will require a board or device specific function to
2688 If defined, a function that provides delays in the FPGA
2689 configuration driver.
2691 CONFIG_SYS_FPGA_CHECK_CTRLC
2692 Allow Control-C to interrupt FPGA configuration
2694 CONFIG_SYS_FPGA_CHECK_ERROR
2696 Check for configuration errors during FPGA bitfile
2697 loading. For example, abort during Virtex II
2698 configuration if the INIT_B line goes low (which
2699 indicated a CRC error).
2701 CONFIG_SYS_FPGA_WAIT_INIT
2703 Maximum time to wait for the INIT_B line to deassert
2704 after PROB_B has been deasserted during a Virtex II
2705 FPGA configuration sequence. The default time is 500
2708 CONFIG_SYS_FPGA_WAIT_BUSY
2710 Maximum time to wait for BUSY to deassert during
2711 Virtex II FPGA configuration. The default is 5 ms.
2713 CONFIG_SYS_FPGA_WAIT_CONFIG
2715 Time to wait after FPGA configuration. The default is
2718 - Configuration Management:
2721 If defined, this string will be added to the U-Boot
2722 version information (U_BOOT_VERSION)
2724 - Vendor Parameter Protection:
2726 U-Boot considers the values of the environment
2727 variables "serial#" (Board Serial Number) and
2728 "ethaddr" (Ethernet Address) to be parameters that
2729 are set once by the board vendor / manufacturer, and
2730 protects these variables from casual modification by
2731 the user. Once set, these variables are read-only,
2732 and write or delete attempts are rejected. You can
2733 change this behaviour:
2735 If CONFIG_ENV_OVERWRITE is #defined in your config
2736 file, the write protection for vendor parameters is
2737 completely disabled. Anybody can change or delete
2740 Alternatively, if you #define _both_ CONFIG_ETHADDR
2741 _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
2742 Ethernet address is installed in the environment,
2743 which can be changed exactly ONCE by the user. [The
2744 serial# is unaffected by this, i. e. it remains
2747 The same can be accomplished in a more flexible way
2748 for any variable by configuring the type of access
2749 to allow for those variables in the ".flags" variable
2750 or define CONFIG_ENV_FLAGS_LIST_STATIC.
2755 Define this variable to enable the reservation of
2756 "protected RAM", i. e. RAM which is not overwritten
2757 by U-Boot. Define CONFIG_PRAM to hold the number of
2758 kB you want to reserve for pRAM. You can overwrite
2759 this default value by defining an environment
2760 variable "pram" to the number of kB you want to
2761 reserve. Note that the board info structure will
2762 still show the full amount of RAM. If pRAM is
2763 reserved, a new environment variable "mem" will
2764 automatically be defined to hold the amount of
2765 remaining RAM in a form that can be passed as boot
2766 argument to Linux, for instance like that:
2768 setenv bootargs ... mem=\${mem}
2771 This way you can tell Linux not to use this memory,
2772 either, which results in a memory region that will
2773 not be affected by reboots.
2775 *WARNING* If your board configuration uses automatic
2776 detection of the RAM size, you must make sure that
2777 this memory test is non-destructive. So far, the
2778 following board configurations are known to be
2781 IVMS8, IVML24, SPD8xx, TQM8xxL,
2782 HERMES, IP860, RPXlite, LWMON,
2785 - Access to physical memory region (> 4GB)
2786 Some basic support is provided for operations on memory not
2787 normally accessible to U-Boot - e.g. some architectures
2788 support access to more than 4GB of memory on 32-bit
2789 machines using physical address extension or similar.
2790 Define CONFIG_PHYSMEM to access this basic support, which
2791 currently only supports clearing the memory.
2796 Define this variable to stop the system in case of a
2797 fatal error, so that you have to reset it manually.
2798 This is probably NOT a good idea for an embedded
2799 system where you want the system to reboot
2800 automatically as fast as possible, but it may be
2801 useful during development since you can try to debug
2802 the conditions that lead to the situation.
2804 CONFIG_NET_RETRY_COUNT
2806 This variable defines the number of retries for
2807 network operations like ARP, RARP, TFTP, or BOOTP
2808 before giving up the operation. If not defined, a
2809 default value of 5 is used.
2813 Timeout waiting for an ARP reply in milliseconds.
2817 Timeout in milliseconds used in NFS protocol.
2818 If you encounter "ERROR: Cannot umount" in nfs command,
2819 try longer timeout such as
2820 #define CONFIG_NFS_TIMEOUT 10000UL
2822 - Command Interpreter:
2823 CONFIG_AUTO_COMPLETE
2825 Enable auto completion of commands using TAB.
2827 Note that this feature has NOT been implemented yet
2828 for the "hush" shell.
2831 CONFIG_SYS_HUSH_PARSER
2833 Define this variable to enable the "hush" shell (from
2834 Busybox) as command line interpreter, thus enabling
2835 powerful command line syntax like
2836 if...then...else...fi conditionals or `&&' and '||'
2837 constructs ("shell scripts").
2839 If undefined, you get the old, much simpler behaviour
2840 with a somewhat smaller memory footprint.
2843 CONFIG_SYS_PROMPT_HUSH_PS2
2845 This defines the secondary prompt string, which is
2846 printed when the command interpreter needs more input
2847 to complete a command. Usually "> ".
2851 In the current implementation, the local variables
2852 space and global environment variables space are
2853 separated. Local variables are those you define by
2854 simply typing `name=value'. To access a local
2855 variable later on, you have write `$name' or
2856 `${name}'; to execute the contents of a variable
2857 directly type `$name' at the command prompt.
2859 Global environment variables are those you use
2860 setenv/printenv to work with. To run a command stored
2861 in such a variable, you need to use the run command,
2862 and you must not use the '$' sign to access them.
2864 To store commands and special characters in a
2865 variable, please use double quotation marks
2866 surrounding the whole text of the variable, instead
2867 of the backslashes before semicolons and special
2870 - Commandline Editing and History:
2871 CONFIG_CMDLINE_EDITING
2873 Enable editing and History functions for interactive
2874 commandline input operations
2876 - Default Environment:
2877 CONFIG_EXTRA_ENV_SETTINGS
2879 Define this to contain any number of null terminated
2880 strings (variable = value pairs) that will be part of
2881 the default environment compiled into the boot image.
2883 For example, place something like this in your
2884 board's config file:
2886 #define CONFIG_EXTRA_ENV_SETTINGS \
2890 Warning: This method is based on knowledge about the
2891 internal format how the environment is stored by the
2892 U-Boot code. This is NOT an official, exported
2893 interface! Although it is unlikely that this format
2894 will change soon, there is no guarantee either.
2895 You better know what you are doing here.
2897 Note: overly (ab)use of the default environment is
2898 discouraged. Make sure to check other ways to preset
2899 the environment like the "source" command or the
2902 CONFIG_ENV_VARS_UBOOT_CONFIG
2904 Define this in order to add variables describing the
2905 U-Boot build configuration to the default environment.
2906 These will be named arch, cpu, board, vendor, and soc.
2908 Enabling this option will cause the following to be defined:
2916 CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG
2918 Define this in order to add variables describing certain
2919 run-time determined information about the hardware to the
2920 environment. These will be named board_name, board_rev.
2922 CONFIG_DELAY_ENVIRONMENT
2924 Normally the environment is loaded when the board is
2925 intialised so that it is available to U-Boot. This inhibits
2926 that so that the environment is not available until
2927 explicitly loaded later by U-Boot code. With CONFIG_OF_CONTROL
2928 this is instead controlled by the value of
2929 /config/load-environment.
2931 - DataFlash Support:
2932 CONFIG_HAS_DATAFLASH
2934 Defining this option enables DataFlash features and
2935 allows to read/write in Dataflash via the standard
2938 - Serial Flash support
2941 Defining this option enables SPI flash commands
2942 'sf probe/read/write/erase/update'.
2944 Usage requires an initial 'probe' to define the serial
2945 flash parameters, followed by read/write/erase/update
2948 The following defaults may be provided by the platform
2949 to handle the common case when only a single serial
2950 flash is present on the system.
2952 CONFIG_SF_DEFAULT_BUS Bus identifier
2953 CONFIG_SF_DEFAULT_CS Chip-select
2954 CONFIG_SF_DEFAULT_MODE (see include/spi.h)
2955 CONFIG_SF_DEFAULT_SPEED in Hz
2959 Define this option to include a destructive SPI flash
2962 CONFIG_SPI_FLASH_BAR Ban/Extended Addr Reg
2964 Define this option to use the Bank addr/Extended addr
2965 support on SPI flashes which has size > 16Mbytes.
2967 CONFIG_SF_DUAL_FLASH Dual flash memories
2969 Define this option to use dual flash support where two flash
2970 memories can be connected with a given cs line.
2971 currently Xilinx Zynq qspi support these type of connections.
2973 CONFIG_SYS_SPI_ST_ENABLE_WP_PIN
2974 enable the W#/Vpp signal to disable writing to the status
2975 register on ST MICRON flashes like the N25Q128.
2976 The status register write enable/disable bit, combined with
2977 the W#/VPP signal provides hardware data protection for the
2978 device as follows: When the enable/disable bit is set to 1,
2979 and the W#/VPP signal is driven LOW, the status register
2980 nonvolatile bits become read-only and the WRITE STATUS REGISTER
2981 operation will not execute. The only way to exit this
2982 hardware-protected mode is to drive W#/VPP HIGH.
2984 - SystemACE Support:
2987 Adding this option adds support for Xilinx SystemACE
2988 chips attached via some sort of local bus. The address
2989 of the chip must also be defined in the
2990 CONFIG_SYS_SYSTEMACE_BASE macro. For example:
2992 #define CONFIG_SYSTEMACE
2993 #define CONFIG_SYS_SYSTEMACE_BASE 0xf0000000
2995 When SystemACE support is added, the "ace" device type
2996 becomes available to the fat commands, i.e. fatls.
2998 - TFTP Fixed UDP Port:
3001 If this is defined, the environment variable tftpsrcp
3002 is used to supply the TFTP UDP source port value.
3003 If tftpsrcp isn't defined, the normal pseudo-random port
3004 number generator is used.
3006 Also, the environment variable tftpdstp is used to supply
3007 the TFTP UDP destination port value. If tftpdstp isn't
3008 defined, the normal port 69 is used.
3010 The purpose for tftpsrcp is to allow a TFTP server to
3011 blindly start the TFTP transfer using the pre-configured
3012 target IP address and UDP port. This has the effect of
3013 "punching through" the (Windows XP) firewall, allowing
3014 the remainder of the TFTP transfer to proceed normally.
3015 A better solution is to properly configure the firewall,
3016 but sometimes that is not allowed.
3021 This enables a generic 'hash' command which can produce
3022 hashes / digests from a few algorithms (e.g. SHA1, SHA256).
3026 Enable the hash verify command (hash -v). This adds to code
3029 CONFIG_SHA1 - support SHA1 hashing
3030 CONFIG_SHA256 - support SHA256 hashing
3032 Note: There is also a sha1sum command, which should perhaps
3033 be deprecated in favour of 'hash sha1'.
3035 - Freescale i.MX specific commands:
3036 CONFIG_CMD_HDMIDETECT
3037 This enables 'hdmidet' command which returns true if an
3038 HDMI monitor is detected. This command is i.MX 6 specific.
3041 This enables the 'bmode' (bootmode) command for forcing
3042 a boot from specific media.
3044 This is useful for forcing the ROM's usb downloader to
3045 activate upon a watchdog reset which is nice when iterating
3046 on U-Boot. Using the reset button or running bmode normal
3047 will set it back to normal. This command currently
3048 supports i.MX53 and i.MX6.
3053 This enables the RSA algorithm used for FIT image verification
3054 in U-Boot. See doc/uImage.FIT/signature.txt for more information.
3056 The signing part is build into mkimage regardless of this
3059 - bootcount support:
3060 CONFIG_BOOTCOUNT_LIMIT
3062 This enables the bootcounter support, see:
3063 http://www.denx.de/wiki/DULG/UBootBootCountLimit
3066 enable special bootcounter support on at91sam9xe based boards.
3068 enable special bootcounter support on blackfin based boards.
3070 enable special bootcounter support on da850 based boards.
3071 CONFIG_BOOTCOUNT_RAM
3072 enable support for the bootcounter in RAM
3073 CONFIG_BOOTCOUNT_I2C
3074 enable support for the bootcounter on an i2c (like RTC) device.
3075 CONFIG_SYS_I2C_RTC_ADDR = i2c chip address
3076 CONFIG_SYS_BOOTCOUNT_ADDR = i2c addr which is used for
3078 CONFIG_BOOTCOUNT_ALEN = address len
3080 - Show boot progress:
3081 CONFIG_SHOW_BOOT_PROGRESS
3083 Defining this option allows to add some board-
3084 specific code (calling a user-provided function
3085 "show_boot_progress(int)") that enables you to show
3086 the system's boot progress on some display (for
3087 example, some LED's) on your board. At the moment,
3088 the following checkpoints are implemented:
3090 - Detailed boot stage timing
3092 Define this option to get detailed timing of each stage
3093 of the boot process.
3095 CONFIG_BOOTSTAGE_USER_COUNT
3096 This is the number of available user bootstage records.
3097 Each time you call bootstage_mark(BOOTSTAGE_ID_ALLOC, ...)
3098 a new ID will be allocated from this stash. If you exceed
3099 the limit, recording will stop.
3101 CONFIG_BOOTSTAGE_REPORT
3102 Define this to print a report before boot, similar to this:
3104 Timer summary in microseconds:
3107 3,575,678 3,575,678 board_init_f start
3108 3,575,695 17 arch_cpu_init A9
3109 3,575,777 82 arch_cpu_init done
3110 3,659,598 83,821 board_init_r start
3111 3,910,375 250,777 main_loop
3112 29,916,167 26,005,792 bootm_start
3113 30,361,327 445,160 start_kernel
3115 CONFIG_CMD_BOOTSTAGE
3116 Add a 'bootstage' command which supports printing a report
3117 and un/stashing of bootstage data.
3119 CONFIG_BOOTSTAGE_FDT
3120 Stash the bootstage information in the FDT. A root 'bootstage'
3121 node is created with each bootstage id as a child. Each child
3122 has a 'name' property and either 'mark' containing the
3123 mark time in microsecond, or 'accum' containing the
3124 accumulated time for that bootstage id in microseconds.
3129 name = "board_init_f";
3138 Code in the Linux kernel can find this in /proc/devicetree.
3140 Legacy uImage format:
3143 1 common/cmd_bootm.c before attempting to boot an image
3144 -1 common/cmd_bootm.c Image header has bad magic number
3145 2 common/cmd_bootm.c Image header has correct magic number
3146 -2 common/cmd_bootm.c Image header has bad checksum
3147 3 common/cmd_bootm.c Image header has correct checksum
3148 -3 common/cmd_bootm.c Image data has bad checksum
3149 4 common/cmd_bootm.c Image data has correct checksum
3150 -4 common/cmd_bootm.c Image is for unsupported architecture
3151 5 common/cmd_bootm.c Architecture check OK
3152 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi)
3153 6 common/cmd_bootm.c Image Type check OK
3154 -6 common/cmd_bootm.c gunzip uncompression error
3155 -7 common/cmd_bootm.c Unimplemented compression type
3156 7 common/cmd_bootm.c Uncompression OK
3157 8 common/cmd_bootm.c No uncompress/copy overwrite error
3158 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX)
3160 9 common/image.c Start initial ramdisk verification
3161 -10 common/image.c Ramdisk header has bad magic number
3162 -11 common/image.c Ramdisk header has bad checksum
3163 10 common/image.c Ramdisk header is OK
3164 -12 common/image.c Ramdisk data has bad checksum
3165 11 common/image.c Ramdisk data has correct checksum
3166 12 common/image.c Ramdisk verification complete, start loading
3167 -13 common/image.c Wrong Image Type (not PPC Linux ramdisk)
3168 13 common/image.c Start multifile image verification
3169 14 common/image.c No initial ramdisk, no multifile, continue.
3171 15 arch/<arch>/lib/bootm.c All preparation done, transferring control to OS
3173 -30 arch/powerpc/lib/board.c Fatal error, hang the system
3174 -31 post/post.c POST test failed, detected by post_output_backlog()
3175 -32 post/post.c POST test failed, detected by post_run_single()
3177 34 common/cmd_doc.c before loading a Image from a DOC device
3178 -35 common/cmd_doc.c Bad usage of "doc" command
3179 35 common/cmd_doc.c correct usage of "doc" command
3180 -36 common/cmd_doc.c No boot device
3181 36 common/cmd_doc.c correct boot device
3182 -37 common/cmd_doc.c Unknown Chip ID on boot device
3183 37 common/cmd_doc.c correct chip ID found, device available
3184 -38 common/cmd_doc.c Read Error on boot device
3185 38 common/cmd_doc.c reading Image header from DOC device OK
3186 -39 common/cmd_doc.c Image header has bad magic number
3187 39 common/cmd_doc.c Image header has correct magic number
3188 -40 common/cmd_doc.c Error reading Image from DOC device
3189 40 common/cmd_doc.c Image header has correct magic number
3190 41 common/cmd_ide.c before loading a Image from a IDE device
3191 -42 common/cmd_ide.c Bad usage of "ide" command
3192 42 common/cmd_ide.c correct usage of "ide" command
3193 -43 common/cmd_ide.c No boot device
3194 43 common/cmd_ide.c boot device found
3195 -44 common/cmd_ide.c Device not available
3196 44 common/cmd_ide.c Device available
3197 -45 common/cmd_ide.c wrong partition selected
3198 45 common/cmd_ide.c partition selected
3199 -46 common/cmd_ide.c Unknown partition table
3200 46 common/cmd_ide.c valid partition table found
3201 -47 common/cmd_ide.c Invalid partition type
3202 47 common/cmd_ide.c correct partition type
3203 -48 common/cmd_ide.c Error reading Image Header on boot device
3204 48 common/cmd_ide.c reading Image Header from IDE device OK
3205 -49 common/cmd_ide.c Image header has bad magic number
3206 49 common/cmd_ide.c Image header has correct magic number
3207 -50 common/cmd_ide.c Image header has bad checksum
3208 50 common/cmd_ide.c Image header has correct checksum
3209 -51 common/cmd_ide.c Error reading Image from IDE device
3210 51 common/cmd_ide.c reading Image from IDE device OK
3211 52 common/cmd_nand.c before loading a Image from a NAND device
3212 -53 common/cmd_nand.c Bad usage of "nand" command
3213 53 common/cmd_nand.c correct usage of "nand" command
3214 -54 common/cmd_nand.c No boot device
3215 54 common/cmd_nand.c boot device found
3216 -55 common/cmd_nand.c Unknown Chip ID on boot device
3217 55 common/cmd_nand.c correct chip ID found, device available
3218 -56 common/cmd_nand.c Error reading Image Header on boot device
3219 56 common/cmd_nand.c reading Image Header from NAND device OK
3220 -57 common/cmd_nand.c Image header has bad magic number
3221 57 common/cmd_nand.c Image header has correct magic number
3222 -58 common/cmd_nand.c Error reading Image from NAND device
3223 58 common/cmd_nand.c reading Image from NAND device OK
3225 -60 common/env_common.c Environment has a bad CRC, using default
3227 64 net/eth.c starting with Ethernet configuration.
3228 -64 net/eth.c no Ethernet found.
3229 65 net/eth.c Ethernet found.
3231 -80 common/cmd_net.c usage wrong
3232 80 common/cmd_net.c before calling NetLoop()
3233 -81 common/cmd_net.c some error in NetLoop() occurred
3234 81 common/cmd_net.c NetLoop() back without error
3235 -82 common/cmd_net.c size == 0 (File with size 0 loaded)
3236 82 common/cmd_net.c trying automatic boot
3237 83 common/cmd_net.c running "source" command
3238 -83 common/cmd_net.c some error in automatic boot or "source" command
3239 84 common/cmd_net.c end without errors
3244 100 common/cmd_bootm.c Kernel FIT Image has correct format
3245 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format
3246 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration
3247 -101 common/cmd_bootm.c Can't get configuration for kernel subimage
3248 102 common/cmd_bootm.c Kernel unit name specified
3249 -103 common/cmd_bootm.c Can't get kernel subimage node offset
3250 103 common/cmd_bootm.c Found configuration node
3251 104 common/cmd_bootm.c Got kernel subimage node offset
3252 -104 common/cmd_bootm.c Kernel subimage hash verification failed
3253 105 common/cmd_bootm.c Kernel subimage hash verification OK
3254 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture
3255 106 common/cmd_bootm.c Architecture check OK
3256 -106 common/cmd_bootm.c Kernel subimage has wrong type
3257 107 common/cmd_bootm.c Kernel subimage type OK
3258 -107 common/cmd_bootm.c Can't get kernel subimage data/size
3259 108 common/cmd_bootm.c Got kernel subimage data/size
3260 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT)
3261 -109 common/cmd_bootm.c Can't get kernel subimage type
3262 -110 common/cmd_bootm.c Can't get kernel subimage comp
3263 -111 common/cmd_bootm.c Can't get kernel subimage os
3264 -112 common/cmd_bootm.c Can't get kernel subimage load address
3265 -113 common/cmd_bootm.c Image uncompress/copy overwrite error
3267 120 common/image.c Start initial ramdisk verification
3268 -120 common/image.c Ramdisk FIT image has incorrect format
3269 121 common/image.c Ramdisk FIT image has correct format
3270 122 common/image.c No ramdisk subimage unit name, using configuration
3271 -122 common/image.c Can't get configuration for ramdisk subimage
3272 123 common/image.c Ramdisk unit name specified
3273 -124 common/image.c Can't get ramdisk subimage node offset
3274 125 common/image.c Got ramdisk subimage node offset
3275 -125 common/image.c Ramdisk subimage hash verification failed
3276 126 common/image.c Ramdisk subimage hash verification OK
3277 -126 common/image.c Ramdisk subimage for unsupported architecture
3278 127 common/image.c Architecture check OK
3279 -127 common/image.c Can't get ramdisk subimage data/size
3280 128 common/image.c Got ramdisk subimage data/size
3281 129 common/image.c Can't get ramdisk load address
3282 -129 common/image.c Got ramdisk load address
3284 -130 common/cmd_doc.c Incorrect FIT image format
3285 131 common/cmd_doc.c FIT image format OK
3287 -140 common/cmd_ide.c Incorrect FIT image format
3288 141 common/cmd_ide.c FIT image format OK
3290 -150 common/cmd_nand.c Incorrect FIT image format
3291 151 common/cmd_nand.c FIT image format OK
3293 - legacy image format:
3294 CONFIG_IMAGE_FORMAT_LEGACY
3295 enables the legacy image format support in U-Boot.
3298 enabled if CONFIG_FIT_SIGNATURE is not defined.
3300 CONFIG_DISABLE_IMAGE_LEGACY
3301 disable the legacy image format
3303 This define is introduced, as the legacy image format is
3304 enabled per default for backward compatibility.
3306 - FIT image support:
3308 Enable support for the FIT uImage format.
3310 CONFIG_FIT_BEST_MATCH
3311 When no configuration is explicitly selected, default to the
3312 one whose fdt's compatibility field best matches that of
3313 U-Boot itself. A match is considered "best" if it matches the
3314 most specific compatibility entry of U-Boot's fdt's root node.
3315 The order of entries in the configuration's fdt is ignored.
3317 CONFIG_FIT_SIGNATURE
3318 This option enables signature verification of FIT uImages,
3319 using a hash signed and verified using RSA. See
3320 doc/uImage.FIT/signature.txt for more details.
3322 WARNING: When relying on signed FIT images with required
3323 signature check the legacy image format is default
3324 disabled. If a board need legacy image format support
3325 enable this through CONFIG_IMAGE_FORMAT_LEGACY
3327 CONFIG_FIT_DISABLE_SHA256
3328 Supporting SHA256 hashes has quite an impact on binary size.
3329 For constrained systems sha256 hash support can be disabled
3332 - Standalone program support:
3333 CONFIG_STANDALONE_LOAD_ADDR
3335 This option defines a board specific value for the
3336 address where standalone program gets loaded, thus
3337 overwriting the architecture dependent default
3340 - Frame Buffer Address:
3343 Define CONFIG_FB_ADDR if you want to use specific
3344 address for frame buffer. This is typically the case
3345 when using a graphics controller has separate video
3346 memory. U-Boot will then place the frame buffer at
3347 the given address instead of dynamically reserving it
3348 in system RAM by calling lcd_setmem(), which grabs
3349 the memory for the frame buffer depending on the
3350 configured panel size.
3352 Please see board_init_f function.
3354 - Automatic software updates via TFTP server
3356 CONFIG_UPDATE_TFTP_CNT_MAX
3357 CONFIG_UPDATE_TFTP_MSEC_MAX
3359 These options enable and control the auto-update feature;
3360 for a more detailed description refer to doc/README.update.
3362 - MTD Support (mtdparts command, UBI support)
3365 Adds the MTD device infrastructure from the Linux kernel.
3366 Needed for mtdparts command support.
3368 CONFIG_MTD_PARTITIONS
3370 Adds the MTD partitioning infrastructure from the Linux
3371 kernel. Needed for UBI support.
3373 CONFIG_MTD_NAND_VERIFY_WRITE
3374 verify if the written data is correct reread.
3379 Adds commands for interacting with MTD partitions formatted
3380 with the UBI flash translation layer
3382 Requires also defining CONFIG_RBTREE
3384 CONFIG_UBI_SILENCE_MSG
3386 Make the verbose messages from UBI stop printing. This leaves
3387 warnings and errors enabled.
3390 CONFIG_MTD_UBI_WL_THRESHOLD
3391 This parameter defines the maximum difference between the highest
3392 erase counter value and the lowest erase counter value of eraseblocks
3393 of UBI devices. When this threshold is exceeded, UBI starts performing
3394 wear leveling by means of moving data from eraseblock with low erase
3395 counter to eraseblocks with high erase counter.
3397 The default value should be OK for SLC NAND flashes, NOR flashes and
3398 other flashes which have eraseblock life-cycle 100000 or more.
3399 However, in case of MLC NAND flashes which typically have eraseblock
3400 life-cycle less than 10000, the threshold should be lessened (e.g.,
3401 to 128 or 256, although it does not have to be power of 2).
3405 CONFIG_MTD_UBI_BEB_LIMIT
3406 This option specifies the maximum bad physical eraseblocks UBI
3407 expects on the MTD device (per 1024 eraseblocks). If the
3408 underlying flash does not admit of bad eraseblocks (e.g. NOR
3409 flash), this value is ignored.
3411 NAND datasheets often specify the minimum and maximum NVM
3412 (Number of Valid Blocks) for the flashes' endurance lifetime.
3413 The maximum expected bad eraseblocks per 1024 eraseblocks
3414 then can be calculated as "1024 * (1 - MinNVB / MaxNVB)",
3415 which gives 20 for most NANDs (MaxNVB is basically the total
3416 count of eraseblocks on the chip).
3418 To put it differently, if this value is 20, UBI will try to
3419 reserve about 1.9% of physical eraseblocks for bad blocks
3420 handling. And that will be 1.9% of eraseblocks on the entire
3421 NAND chip, not just the MTD partition UBI attaches. This means
3422 that if you have, say, a NAND flash chip admits maximum 40 bad
3423 eraseblocks, and it is split on two MTD partitions of the same
3424 size, UBI will reserve 40 eraseblocks when attaching a
3429 CONFIG_MTD_UBI_FASTMAP
3430 Fastmap is a mechanism which allows attaching an UBI device
3431 in nearly constant time. Instead of scanning the whole MTD device it
3432 only has to locate a checkpoint (called fastmap) on the device.
3433 The on-flash fastmap contains all information needed to attach
3434 the device. Using fastmap makes only sense on large devices where
3435 attaching by scanning takes long. UBI will not automatically install
3436 a fastmap on old images, but you can set the UBI parameter
3437 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT to 1 if you want so. Please note
3438 that fastmap-enabled images are still usable with UBI implementations
3439 without fastmap support. On typical flash devices the whole fastmap
3440 fits into one PEB. UBI will reserve PEBs to hold two fastmaps.
3442 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT
3443 Set this parameter to enable fastmap automatically on images
3450 Adds commands for interacting with UBI volumes formatted as
3451 UBIFS. UBIFS is read-only in u-boot.
3453 Requires UBI support as well as CONFIG_LZO
3455 CONFIG_UBIFS_SILENCE_MSG
3457 Make the verbose messages from UBIFS stop printing. This leaves
3458 warnings and errors enabled.
3462 Enable building of SPL globally.
3465 LDSCRIPT for linking the SPL binary.
3467 CONFIG_SPL_MAX_FOOTPRINT
3468 Maximum size in memory allocated to the SPL, BSS included.
3469 When defined, the linker checks that the actual memory
3470 used by SPL from _start to __bss_end does not exceed it.
3471 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
3472 must not be both defined at the same time.
3475 Maximum size of the SPL image (text, data, rodata, and
3476 linker lists sections), BSS excluded.
3477 When defined, the linker checks that the actual size does
3480 CONFIG_SPL_TEXT_BASE
3481 TEXT_BASE for linking the SPL binary.
3483 CONFIG_SPL_RELOC_TEXT_BASE
3484 Address to relocate to. If unspecified, this is equal to
3485 CONFIG_SPL_TEXT_BASE (i.e. no relocation is done).
3487 CONFIG_SPL_BSS_START_ADDR
3488 Link address for the BSS within the SPL binary.
3490 CONFIG_SPL_BSS_MAX_SIZE
3491 Maximum size in memory allocated to the SPL BSS.
3492 When defined, the linker checks that the actual memory used
3493 by SPL from __bss_start to __bss_end does not exceed it.
3494 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
3495 must not be both defined at the same time.
3498 Adress of the start of the stack SPL will use
3500 CONFIG_SPL_RELOC_STACK
3501 Adress of the start of the stack SPL will use after
3502 relocation. If unspecified, this is equal to
3505 CONFIG_SYS_SPL_MALLOC_START
3506 Starting address of the malloc pool used in SPL.
3508 CONFIG_SYS_SPL_MALLOC_SIZE
3509 The size of the malloc pool used in SPL.
3511 CONFIG_SPL_FRAMEWORK
3512 Enable the SPL framework under common/. This framework
3513 supports MMC, NAND and YMODEM loading of U-Boot and NAND
3514 NAND loading of the Linux Kernel.
3517 Enable booting directly to an OS from SPL.
3518 See also: doc/README.falcon
3520 CONFIG_SPL_DISPLAY_PRINT
3521 For ARM, enable an optional function to print more information
3522 about the running system.
3524 CONFIG_SPL_INIT_MINIMAL
3525 Arch init code should be built for a very small image
3527 CONFIG_SPL_LIBCOMMON_SUPPORT
3528 Support for common/libcommon.o in SPL binary
3530 CONFIG_SPL_LIBDISK_SUPPORT
3531 Support for disk/libdisk.o in SPL binary
3533 CONFIG_SPL_I2C_SUPPORT
3534 Support for drivers/i2c/libi2c.o in SPL binary
3536 CONFIG_SPL_GPIO_SUPPORT
3537 Support for drivers/gpio/libgpio.o in SPL binary
3539 CONFIG_SPL_MMC_SUPPORT
3540 Support for drivers/mmc/libmmc.o in SPL binary
3542 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_SECTOR,
3543 CONFIG_SYS_U_BOOT_MAX_SIZE_SECTORS,
3544 CONFIG_SYS_MMC_SD_FAT_BOOT_PARTITION
3545 Address, size and partition on the MMC to load U-Boot from
3546 when the MMC is being used in raw mode.
3548 CONFIG_SYS_MMCSD_RAW_MODE_KERNEL_SECTOR
3549 Sector to load kernel uImage from when MMC is being
3550 used in raw mode (for Falcon mode)
3552 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTOR,
3553 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTORS
3554 Sector and number of sectors to load kernel argument
3555 parameters from when MMC is being used in raw mode
3558 CONFIG_SPL_FAT_SUPPORT
3559 Support for fs/fat/libfat.o in SPL binary
3561 CONFIG_SPL_FAT_LOAD_PAYLOAD_NAME
3562 Filename to read to load U-Boot when reading from FAT
3564 CONFIG_SPL_FAT_LOAD_KERNEL_NAME
3565 Filename to read to load kernel uImage when reading
3566 from FAT (for Falcon mode)
3568 CONFIG_SPL_FAT_LOAD_ARGS_NAME
3569 Filename to read to load kernel argument parameters
3570 when reading from FAT (for Falcon mode)
3572 CONFIG_SPL_MPC83XX_WAIT_FOR_NAND
3573 Set this for NAND SPL on PPC mpc83xx targets, so that
3574 start.S waits for the rest of the SPL to load before
3575 continuing (the hardware starts execution after just
3576 loading the first page rather than the full 4K).
3578 CONFIG_SPL_SKIP_RELOCATE
3579 Avoid SPL relocation
3581 CONFIG_SPL_NAND_BASE
3582 Include nand_base.c in the SPL. Requires
3583 CONFIG_SPL_NAND_DRIVERS.
3585 CONFIG_SPL_NAND_DRIVERS
3586 SPL uses normal NAND drivers, not minimal drivers.
3589 Include standard software ECC in the SPL
3591 CONFIG_SPL_NAND_SIMPLE
3592 Support for NAND boot using simple NAND drivers that
3593 expose the cmd_ctrl() interface.
3595 CONFIG_SPL_MTD_SUPPORT
3596 Support for the MTD subsystem within SPL. Useful for
3597 environment on NAND support within SPL.
3599 CONFIG_SPL_MPC8XXX_INIT_DDR_SUPPORT
3600 Set for the SPL on PPC mpc8xxx targets, support for
3601 drivers/ddr/fsl/libddr.o in SPL binary.
3603 CONFIG_SPL_COMMON_INIT_DDR
3604 Set for common ddr init with serial presence detect in
3607 CONFIG_SYS_NAND_5_ADDR_CYCLE, CONFIG_SYS_NAND_PAGE_COUNT,
3608 CONFIG_SYS_NAND_PAGE_SIZE, CONFIG_SYS_NAND_OOBSIZE,
3609 CONFIG_SYS_NAND_BLOCK_SIZE, CONFIG_SYS_NAND_BAD_BLOCK_POS,
3610 CONFIG_SYS_NAND_ECCPOS, CONFIG_SYS_NAND_ECCSIZE,
3611 CONFIG_SYS_NAND_ECCBYTES
3612 Defines the size and behavior of the NAND that SPL uses
3615 CONFIG_SPL_NAND_BOOT
3616 Add support NAND boot
3618 CONFIG_SYS_NAND_U_BOOT_OFFS
3619 Location in NAND to read U-Boot from
3621 CONFIG_SYS_NAND_U_BOOT_DST
3622 Location in memory to load U-Boot to
3624 CONFIG_SYS_NAND_U_BOOT_SIZE
3625 Size of image to load
3627 CONFIG_SYS_NAND_U_BOOT_START
3628 Entry point in loaded image to jump to
3630 CONFIG_SYS_NAND_HW_ECC_OOBFIRST
3631 Define this if you need to first read the OOB and then the
3632 data. This is used for example on davinci plattforms.
3634 CONFIG_SPL_OMAP3_ID_NAND
3635 Support for an OMAP3-specific set of functions to return the
3636 ID and MFR of the first attached NAND chip, if present.
3638 CONFIG_SPL_SERIAL_SUPPORT
3639 Support for drivers/serial/libserial.o in SPL binary
3641 CONFIG_SPL_SPI_FLASH_SUPPORT
3642 Support for drivers/mtd/spi/libspi_flash.o in SPL binary
3644 CONFIG_SPL_SPI_SUPPORT
3645 Support for drivers/spi/libspi.o in SPL binary
3647 CONFIG_SPL_RAM_DEVICE
3648 Support for running image already present in ram, in SPL binary
3650 CONFIG_SPL_LIBGENERIC_SUPPORT
3651 Support for lib/libgeneric.o in SPL binary
3653 CONFIG_SPL_ENV_SUPPORT
3654 Support for the environment operating in SPL binary
3656 CONFIG_SPL_NET_SUPPORT
3657 Support for the net/libnet.o in SPL binary.
3658 It conflicts with SPL env from storage medium specified by
3659 CONFIG_ENV_IS_xxx but CONFIG_ENV_IS_NOWHERE
3662 Image offset to which the SPL should be padded before appending
3663 the SPL payload. By default, this is defined as
3664 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3665 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3666 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3669 Final target image containing SPL and payload. Some SPLs
3670 use an arch-specific makefile fragment instead, for
3671 example if more than one image needs to be produced.
3673 CONFIG_FIT_SPL_PRINT
3674 Printing information about a FIT image adds quite a bit of
3675 code to SPL. So this is normally disabled in SPL. Use this
3676 option to re-enable it. This will affect the output of the
3677 bootm command when booting a FIT image.
3681 Enable building of TPL globally.
3684 Image offset to which the TPL should be padded before appending
3685 the TPL payload. By default, this is defined as
3686 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3687 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3688 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3693 [so far only for SMDK2400 boards]
3695 - Modem support enable:
3696 CONFIG_MODEM_SUPPORT
3698 - RTS/CTS Flow control enable:
3701 - Modem debug support:
3702 CONFIG_MODEM_SUPPORT_DEBUG
3704 Enables debugging stuff (char screen[1024], dbg())
3705 for modem support. Useful only with BDI2000.
3707 - Interrupt support (PPC):
3709 There are common interrupt_init() and timer_interrupt()
3710 for all PPC archs. interrupt_init() calls interrupt_init_cpu()
3711 for CPU specific initialization. interrupt_init_cpu()
3712 should set decrementer_count to appropriate value. If
3713 CPU resets decrementer automatically after interrupt
3714 (ppc4xx) it should set decrementer_count to zero.
3715 timer_interrupt() calls timer_interrupt_cpu() for CPU
3716 specific handling. If board has watchdog / status_led
3717 / other_activity_monitor it works automatically from
3718 general timer_interrupt().
3722 In the target system modem support is enabled when a
3723 specific key (key combination) is pressed during
3724 power-on. Otherwise U-Boot will boot normally
3725 (autoboot). The key_pressed() function is called from
3726 board_init(). Currently key_pressed() is a dummy
3727 function, returning 1 and thus enabling modem
3730 If there are no modem init strings in the
3731 environment, U-Boot proceed to autoboot; the
3732 previous output (banner, info printfs) will be
3735 See also: doc/README.Modem
3737 Board initialization settings:
3738 ------------------------------
3740 During Initialization u-boot calls a number of board specific functions
3741 to allow the preparation of board specific prerequisites, e.g. pin setup
3742 before drivers are initialized. To enable these callbacks the
3743 following configuration macros have to be defined. Currently this is
3744 architecture specific, so please check arch/your_architecture/lib/board.c
3745 typically in board_init_f() and board_init_r().
3747 - CONFIG_BOARD_EARLY_INIT_F: Call board_early_init_f()
3748 - CONFIG_BOARD_EARLY_INIT_R: Call board_early_init_r()
3749 - CONFIG_BOARD_LATE_INIT: Call board_late_init()
3750 - CONFIG_BOARD_POSTCLK_INIT: Call board_postclk_init()
3752 Configuration Settings:
3753 -----------------------
3755 - CONFIG_SYS_SUPPORT_64BIT_DATA: Defined automatically if compiled as 64-bit.
3756 Optionally it can be defined to support 64-bit memory commands.
3758 - CONFIG_SYS_LONGHELP: Defined when you want long help messages included;
3759 undefine this when you're short of memory.
3761 - CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default
3762 width of the commands listed in the 'help' command output.
3764 - CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to
3765 prompt for user input.
3767 - CONFIG_SYS_CBSIZE: Buffer size for input from the Console
3769 - CONFIG_SYS_PBSIZE: Buffer size for Console output
3771 - CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands
3773 - CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to
3774 the application (usually a Linux kernel) when it is
3777 - CONFIG_SYS_BAUDRATE_TABLE:
3778 List of legal baudrate settings for this board.
3780 - CONFIG_SYS_CONSOLE_INFO_QUIET
3781 Suppress display of console information at boot.
3783 - CONFIG_SYS_CONSOLE_IS_IN_ENV
3784 If the board specific function
3785 extern int overwrite_console (void);
3786 returns 1, the stdin, stderr and stdout are switched to the
3787 serial port, else the settings in the environment are used.
3789 - CONFIG_SYS_CONSOLE_OVERWRITE_ROUTINE
3790 Enable the call to overwrite_console().
3792 - CONFIG_SYS_CONSOLE_ENV_OVERWRITE
3793 Enable overwrite of previous console environment settings.
3795 - CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END:
3796 Begin and End addresses of the area used by the
3799 - CONFIG_SYS_ALT_MEMTEST:
3800 Enable an alternate, more extensive memory test.
3802 - CONFIG_SYS_MEMTEST_SCRATCH:
3803 Scratch address used by the alternate memory test
3804 You only need to set this if address zero isn't writeable
3806 - CONFIG_SYS_MEM_TOP_HIDE (PPC only):
3807 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header,
3808 this specified memory area will get subtracted from the top
3809 (end) of RAM and won't get "touched" at all by U-Boot. By
3810 fixing up gd->ram_size the Linux kernel should gets passed
3811 the now "corrected" memory size and won't touch it either.
3812 This should work for arch/ppc and arch/powerpc. Only Linux
3813 board ports in arch/powerpc with bootwrapper support that
3814 recalculate the memory size from the SDRAM controller setup
3815 will have to get fixed in Linux additionally.
3817 This option can be used as a workaround for the 440EPx/GRx
3818 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't
3821 WARNING: Please make sure that this value is a multiple of
3822 the Linux page size (normally 4k). If this is not the case,
3823 then the end address of the Linux memory will be located at a
3824 non page size aligned address and this could cause major
3827 - CONFIG_SYS_LOADS_BAUD_CHANGE:
3828 Enable temporary baudrate change while serial download
3830 - CONFIG_SYS_SDRAM_BASE:
3831 Physical start address of SDRAM. _Must_ be 0 here.
3833 - CONFIG_SYS_MBIO_BASE:
3834 Physical start address of Motherboard I/O (if using a
3837 - CONFIG_SYS_FLASH_BASE:
3838 Physical start address of Flash memory.
3840 - CONFIG_SYS_MONITOR_BASE:
3841 Physical start address of boot monitor code (set by
3842 make config files to be same as the text base address
3843 (CONFIG_SYS_TEXT_BASE) used when linking) - same as
3844 CONFIG_SYS_FLASH_BASE when booting from flash.
3846 - CONFIG_SYS_MONITOR_LEN:
3847 Size of memory reserved for monitor code, used to
3848 determine _at_compile_time_ (!) if the environment is
3849 embedded within the U-Boot image, or in a separate
3852 - CONFIG_SYS_MALLOC_LEN:
3853 Size of DRAM reserved for malloc() use.
3855 - CONFIG_SYS_MALLOC_F_LEN
3856 Size of the malloc() pool for use before relocation. If
3857 this is defined, then a very simple malloc() implementation
3858 will become available before relocation. The address is just
3859 below the global data, and the stack is moved down to make
3862 This feature allocates regions with increasing addresses
3863 within the region. calloc() is supported, but realloc()
3864 is not available. free() is supported but does nothing.
3865 The memory will be freed (or in fact just forgotton) when
3866 U-Boot relocates itself.
3868 Pre-relocation malloc() is only supported on ARM and sandbox
3869 at present but is fairly easy to enable for other archs.
3871 - CONFIG_SYS_BOOTM_LEN:
3872 Normally compressed uImages are limited to an
3873 uncompressed size of 8 MBytes. If this is not enough,
3874 you can define CONFIG_SYS_BOOTM_LEN in your board config file
3875 to adjust this setting to your needs.
3877 - CONFIG_SYS_BOOTMAPSZ:
3878 Maximum size of memory mapped by the startup code of
3879 the Linux kernel; all data that must be processed by
3880 the Linux kernel (bd_info, boot arguments, FDT blob if
3881 used) must be put below this limit, unless "bootm_low"
3882 environment variable is defined and non-zero. In such case
3883 all data for the Linux kernel must be between "bootm_low"
3884 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ. The environment
3885 variable "bootm_mapsize" will override the value of
3886 CONFIG_SYS_BOOTMAPSZ. If CONFIG_SYS_BOOTMAPSZ is undefined,
3887 then the value in "bootm_size" will be used instead.
3889 - CONFIG_SYS_BOOT_RAMDISK_HIGH:
3890 Enable initrd_high functionality. If defined then the
3891 initrd_high feature is enabled and the bootm ramdisk subcommand
3894 - CONFIG_SYS_BOOT_GET_CMDLINE:
3895 Enables allocating and saving kernel cmdline in space between
3896 "bootm_low" and "bootm_low" + BOOTMAPSZ.
3898 - CONFIG_SYS_BOOT_GET_KBD:
3899 Enables allocating and saving a kernel copy of the bd_info in
3900 space between "bootm_low" and "bootm_low" + BOOTMAPSZ.
3902 - CONFIG_SYS_MAX_FLASH_BANKS:
3903 Max number of Flash memory banks
3905 - CONFIG_SYS_MAX_FLASH_SECT:
3906 Max number of sectors on a Flash chip
3908 - CONFIG_SYS_FLASH_ERASE_TOUT:
3909 Timeout for Flash erase operations (in ms)
3911 - CONFIG_SYS_FLASH_WRITE_TOUT:
3912 Timeout for Flash write operations (in ms)
3914 - CONFIG_SYS_FLASH_LOCK_TOUT
3915 Timeout for Flash set sector lock bit operation (in ms)
3917 - CONFIG_SYS_FLASH_UNLOCK_TOUT
3918 Timeout for Flash clear lock bits operation (in ms)
3920 - CONFIG_SYS_FLASH_PROTECTION
3921 If defined, hardware flash sectors protection is used
3922 instead of U-Boot software protection.
3924 - CONFIG_SYS_DIRECT_FLASH_TFTP:
3926 Enable TFTP transfers directly to flash memory;
3927 without this option such a download has to be
3928 performed in two steps: (1) download to RAM, and (2)
3929 copy from RAM to flash.
3931 The two-step approach is usually more reliable, since
3932 you can check if the download worked before you erase
3933 the flash, but in some situations (when system RAM is
3934 too limited to allow for a temporary copy of the
3935 downloaded image) this option may be very useful.
3937 - CONFIG_SYS_FLASH_CFI:
3938 Define if the flash driver uses extra elements in the
3939 common flash structure for storing flash geometry.
3941 - CONFIG_FLASH_CFI_DRIVER
3942 This option also enables the building of the cfi_flash driver
3943 in the drivers directory
3945 - CONFIG_FLASH_CFI_MTD
3946 This option enables the building of the cfi_mtd driver
3947 in the drivers directory. The driver exports CFI flash
3950 - CONFIG_SYS_FLASH_USE_BUFFER_WRITE
3951 Use buffered writes to flash.
3953 - CONFIG_FLASH_SPANSION_S29WS_N
3954 s29ws-n MirrorBit flash has non-standard addresses for buffered
3957 - CONFIG_SYS_FLASH_QUIET_TEST
3958 If this option is defined, the common CFI flash doesn't
3959 print it's warning upon not recognized FLASH banks. This
3960 is useful, if some of the configured banks are only
3961 optionally available.
3963 - CONFIG_FLASH_SHOW_PROGRESS
3964 If defined (must be an integer), print out countdown
3965 digits and dots. Recommended value: 45 (9..1) for 80
3966 column displays, 15 (3..1) for 40 column displays.
3968 - CONFIG_FLASH_VERIFY
3969 If defined, the content of the flash (destination) is compared
3970 against the source after the write operation. An error message
3971 will be printed when the contents are not identical.
3972 Please note that this option is useless in nearly all cases,
3973 since such flash programming errors usually are detected earlier
3974 while unprotecting/erasing/programming. Please only enable
3975 this option if you really know what you are doing.
3977 - CONFIG_SYS_RX_ETH_BUFFER:
3978 Defines the number of Ethernet receive buffers. On some
3979 Ethernet controllers it is recommended to set this value
3980 to 8 or even higher (EEPRO100 or 405 EMAC), since all
3981 buffers can be full shortly after enabling the interface
3982 on high Ethernet traffic.
3983 Defaults to 4 if not defined.
3985 - CONFIG_ENV_MAX_ENTRIES
3987 Maximum number of entries in the hash table that is used
3988 internally to store the environment settings. The default
3989 setting is supposed to be generous and should work in most
3990 cases. This setting can be used to tune behaviour; see
3991 lib/hashtable.c for details.
3993 - CONFIG_ENV_FLAGS_LIST_DEFAULT
3994 - CONFIG_ENV_FLAGS_LIST_STATIC
3995 Enable validation of the values given to environment variables when
3996 calling env set. Variables can be restricted to only decimal,
3997 hexadecimal, or boolean. If CONFIG_CMD_NET is also defined,
3998 the variables can also be restricted to IP address or MAC address.
4000 The format of the list is:
4001 type_attribute = [s|d|x|b|i|m]
4002 access_atribute = [a|r|o|c]
4003 attributes = type_attribute[access_atribute]
4004 entry = variable_name[:attributes]
4007 The type attributes are:
4008 s - String (default)
4011 b - Boolean ([1yYtT|0nNfF])
4015 The access attributes are:
4021 - CONFIG_ENV_FLAGS_LIST_DEFAULT
4022 Define this to a list (string) to define the ".flags"
4023 envirnoment variable in the default or embedded environment.
4025 - CONFIG_ENV_FLAGS_LIST_STATIC
4026 Define this to a list (string) to define validation that
4027 should be done if an entry is not found in the ".flags"
4028 environment variable. To override a setting in the static
4029 list, simply add an entry for the same variable name to the
4032 - CONFIG_ENV_ACCESS_IGNORE_FORCE
4033 If defined, don't allow the -f switch to env set override variable
4036 - CONFIG_SYS_GENERIC_BOARD
4037 This selects the architecture-generic board system instead of the
4038 architecture-specific board files. It is intended to move boards
4039 to this new framework over time. Defining this will disable the
4040 arch/foo/lib/board.c file and use common/board_f.c and
4041 common/board_r.c instead. To use this option your architecture
4042 must support it (i.e. must define __HAVE_ARCH_GENERIC_BOARD in
4043 its config.mk file). If you find problems enabling this option on
4044 your board please report the problem and send patches!
4046 - CONFIG_OMAP_PLATFORM_RESET_TIME_MAX_USEC (OMAP only)
4047 This is set by OMAP boards for the max time that reset should
4048 be asserted. See doc/README.omap-reset-time for details on how
4049 the value can be calulated on a given board.
4051 The following definitions that deal with the placement and management
4052 of environment data (variable area); in general, we support the
4053 following configurations:
4055 - CONFIG_BUILD_ENVCRC:
4057 Builds up envcrc with the target environment so that external utils
4058 may easily extract it and embed it in final U-Boot images.
4060 - CONFIG_ENV_IS_IN_FLASH:
4062 Define this if the environment is in flash memory.
4064 a) The environment occupies one whole flash sector, which is
4065 "embedded" in the text segment with the U-Boot code. This
4066 happens usually with "bottom boot sector" or "top boot
4067 sector" type flash chips, which have several smaller
4068 sectors at the start or the end. For instance, such a
4069 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In
4070 such a case you would place the environment in one of the
4071 4 kB sectors - with U-Boot code before and after it. With
4072 "top boot sector" type flash chips, you would put the
4073 environment in one of the last sectors, leaving a gap
4074 between U-Boot and the environment.
4076 - CONFIG_ENV_OFFSET:
4078 Offset of environment data (variable area) to the
4079 beginning of flash memory; for instance, with bottom boot
4080 type flash chips the second sector can be used: the offset
4081 for this sector is given here.
4083 CONFIG_ENV_OFFSET is used relative to CONFIG_SYS_FLASH_BASE.
4087 This is just another way to specify the start address of
4088 the flash sector containing the environment (instead of
4091 - CONFIG_ENV_SECT_SIZE:
4093 Size of the sector containing the environment.
4096 b) Sometimes flash chips have few, equal sized, BIG sectors.
4097 In such a case you don't want to spend a whole sector for
4102 If you use this in combination with CONFIG_ENV_IS_IN_FLASH
4103 and CONFIG_ENV_SECT_SIZE, you can specify to use only a part
4104 of this flash sector for the environment. This saves
4105 memory for the RAM copy of the environment.
4107 It may also save flash memory if you decide to use this
4108 when your environment is "embedded" within U-Boot code,
4109 since then the remainder of the flash sector could be used
4110 for U-Boot code. It should be pointed out that this is
4111 STRONGLY DISCOURAGED from a robustness point of view:
4112 updating the environment in flash makes it always
4113 necessary to erase the WHOLE sector. If something goes
4114 wrong before the contents has been restored from a copy in
4115 RAM, your target system will be dead.
4117 - CONFIG_ENV_ADDR_REDUND
4118 CONFIG_ENV_SIZE_REDUND
4120 These settings describe a second storage area used to hold
4121 a redundant copy of the environment data, so that there is
4122 a valid backup copy in case there is a power failure during
4123 a "saveenv" operation.
4125 BE CAREFUL! Any changes to the flash layout, and some changes to the
4126 source code will make it necessary to adapt <board>/u-boot.lds*
4130 - CONFIG_ENV_IS_IN_NVRAM:
4132 Define this if you have some non-volatile memory device
4133 (NVRAM, battery buffered SRAM) which you want to use for the
4139 These two #defines are used to determine the memory area you
4140 want to use for environment. It is assumed that this memory
4141 can just be read and written to, without any special
4144 BE CAREFUL! The first access to the environment happens quite early
4145 in U-Boot initalization (when we try to get the setting of for the
4146 console baudrate). You *MUST* have mapped your NVRAM area then, or
4149 Please note that even with NVRAM we still use a copy of the
4150 environment in RAM: we could work on NVRAM directly, but we want to
4151 keep settings there always unmodified except somebody uses "saveenv"
4152 to save the current settings.
4155 - CONFIG_ENV_IS_IN_EEPROM:
4157 Use this if you have an EEPROM or similar serial access
4158 device and a driver for it.
4160 - CONFIG_ENV_OFFSET:
4163 These two #defines specify the offset and size of the
4164 environment area within the total memory of your EEPROM.
4166 - CONFIG_SYS_I2C_EEPROM_ADDR:
4167 If defined, specified the chip address of the EEPROM device.
4168 The default address is zero.
4170 - CONFIG_SYS_EEPROM_PAGE_WRITE_BITS:
4171 If defined, the number of bits used to address bytes in a
4172 single page in the EEPROM device. A 64 byte page, for example
4173 would require six bits.
4175 - CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS:
4176 If defined, the number of milliseconds to delay between
4177 page writes. The default is zero milliseconds.
4179 - CONFIG_SYS_I2C_EEPROM_ADDR_LEN:
4180 The length in bytes of the EEPROM memory array address. Note
4181 that this is NOT the chip address length!
4183 - CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW:
4184 EEPROM chips that implement "address overflow" are ones
4185 like Catalyst 24WC04/08/16 which has 9/10/11 bits of
4186 address and the extra bits end up in the "chip address" bit
4187 slots. This makes a 24WC08 (1Kbyte) chip look like four 256
4190 Note that we consider the length of the address field to
4191 still be one byte because the extra address bits are hidden
4192 in the chip address.
4194 - CONFIG_SYS_EEPROM_SIZE:
4195 The size in bytes of the EEPROM device.
4197 - CONFIG_ENV_EEPROM_IS_ON_I2C
4198 define this, if you have I2C and SPI activated, and your
4199 EEPROM, which holds the environment, is on the I2C bus.
4201 - CONFIG_I2C_ENV_EEPROM_BUS
4202 if you have an Environment on an EEPROM reached over
4203 I2C muxes, you can define here, how to reach this
4204 EEPROM. For example:
4206 #define CONFIG_I2C_ENV_EEPROM_BUS 1
4208 EEPROM which holds the environment, is reached over
4209 a pca9547 i2c mux with address 0x70, channel 3.
4211 - CONFIG_ENV_IS_IN_DATAFLASH:
4213 Define this if you have a DataFlash memory device which you
4214 want to use for the environment.
4216 - CONFIG_ENV_OFFSET:
4220 These three #defines specify the offset and size of the
4221 environment area within the total memory of your DataFlash placed
4222 at the specified address.
4224 - CONFIG_ENV_IS_IN_SPI_FLASH:
4226 Define this if you have a SPI Flash memory device which you
4227 want to use for the environment.
4229 - CONFIG_ENV_OFFSET:
4232 These two #defines specify the offset and size of the
4233 environment area within the SPI Flash. CONFIG_ENV_OFFSET must be
4234 aligned to an erase sector boundary.
4236 - CONFIG_ENV_SECT_SIZE:
4238 Define the SPI flash's sector size.
4240 - CONFIG_ENV_OFFSET_REDUND (optional):
4242 This setting describes a second storage area of CONFIG_ENV_SIZE
4243 size used to hold a redundant copy of the environment data, so
4244 that there is a valid backup copy in case there is a power failure
4245 during a "saveenv" operation. CONFIG_ENV_OFFSET_RENDUND must be
4246 aligned to an erase sector boundary.
4248 - CONFIG_ENV_SPI_BUS (optional):
4249 - CONFIG_ENV_SPI_CS (optional):
4251 Define the SPI bus and chip select. If not defined they will be 0.
4253 - CONFIG_ENV_SPI_MAX_HZ (optional):
4255 Define the SPI max work clock. If not defined then use 1MHz.
4257 - CONFIG_ENV_SPI_MODE (optional):
4259 Define the SPI work mode. If not defined then use SPI_MODE_3.
4261 - CONFIG_ENV_IS_IN_REMOTE:
4263 Define this if you have a remote memory space which you
4264 want to use for the local device's environment.
4269 These two #defines specify the address and size of the
4270 environment area within the remote memory space. The
4271 local device can get the environment from remote memory
4272 space by SRIO or PCIE links.
4274 BE CAREFUL! For some special cases, the local device can not use
4275 "saveenv" command. For example, the local device will get the
4276 environment stored in a remote NOR flash by SRIO or PCIE link,
4277 but it can not erase, write this NOR flash by SRIO or PCIE interface.
4279 - CONFIG_ENV_IS_IN_NAND:
4281 Define this if you have a NAND device which you want to use
4282 for the environment.
4284 - CONFIG_ENV_OFFSET:
4287 These two #defines specify the offset and size of the environment
4288 area within the first NAND device. CONFIG_ENV_OFFSET must be
4289 aligned to an erase block boundary.
4291 - CONFIG_ENV_OFFSET_REDUND (optional):
4293 This setting describes a second storage area of CONFIG_ENV_SIZE
4294 size used to hold a redundant copy of the environment data, so
4295 that there is a valid backup copy in case there is a power failure
4296 during a "saveenv" operation. CONFIG_ENV_OFFSET_RENDUND must be
4297 aligned to an erase block boundary.
4299 - CONFIG_ENV_RANGE (optional):
4301 Specifies the length of the region in which the environment
4302 can be written. This should be a multiple of the NAND device's
4303 block size. Specifying a range with more erase blocks than
4304 are needed to hold CONFIG_ENV_SIZE allows bad blocks within
4305 the range to be avoided.
4307 - CONFIG_ENV_OFFSET_OOB (optional):
4309 Enables support for dynamically retrieving the offset of the
4310 environment from block zero's out-of-band data. The
4311 "nand env.oob" command can be used to record this offset.
4312 Currently, CONFIG_ENV_OFFSET_REDUND is not supported when
4313 using CONFIG_ENV_OFFSET_OOB.
4315 - CONFIG_NAND_ENV_DST
4317 Defines address in RAM to which the nand_spl code should copy the
4318 environment. If redundant environment is used, it will be copied to
4319 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE.
4321 - CONFIG_ENV_IS_IN_UBI:
4323 Define this if you have an UBI volume that you want to use for the
4324 environment. This has the benefit of wear-leveling the environment
4325 accesses, which is important on NAND.
4327 - CONFIG_ENV_UBI_PART:
4329 Define this to a string that is the mtd partition containing the UBI.
4331 - CONFIG_ENV_UBI_VOLUME:
4333 Define this to the name of the volume that you want to store the
4336 - CONFIG_ENV_UBI_VOLUME_REDUND:
4338 Define this to the name of another volume to store a second copy of
4339 the environment in. This will enable redundant environments in UBI.
4340 It is assumed that both volumes are in the same MTD partition.
4342 - CONFIG_UBI_SILENCE_MSG
4343 - CONFIG_UBIFS_SILENCE_MSG
4345 You will probably want to define these to avoid a really noisy system
4346 when storing the env in UBI.
4348 - CONFIG_ENV_IS_IN_FAT:
4349 Define this if you want to use the FAT file system for the environment.
4351 - FAT_ENV_INTERFACE:
4353 Define this to a string that is the name of the block device.
4355 - FAT_ENV_DEV_AND_PART:
4357 Define this to a string to specify the partition of the device. It can
4360 "D:P", "D:0", "D", "D:" or "D:auto" (D, P are integers. And P >= 1)
4361 - "D:P": device D partition P. Error occurs if device D has no
4364 - "D" or "D:": device D partition 1 if device D has partition
4365 table, or the whole device D if has no partition
4367 - "D:auto": first partition in device D with bootable flag set.
4368 If none, first valid paratition in device D. If no
4369 partition table then means device D.
4373 It's a string of the FAT file name. This file use to store the
4377 This should be defined. Otherwise it cannot save the envrionment file.
4379 - CONFIG_ENV_IS_IN_MMC:
4381 Define this if you have an MMC device which you want to use for the
4384 - CONFIG_SYS_MMC_ENV_DEV:
4386 Specifies which MMC device the environment is stored in.
4388 - CONFIG_SYS_MMC_ENV_PART (optional):
4390 Specifies which MMC partition the environment is stored in. If not
4391 set, defaults to partition 0, the user area. Common values might be
4392 1 (first MMC boot partition), 2 (second MMC boot partition).
4394 - CONFIG_ENV_OFFSET:
4397 These two #defines specify the offset and size of the environment
4398 area within the specified MMC device.
4400 If offset is positive (the usual case), it is treated as relative to
4401 the start of the MMC partition. If offset is negative, it is treated
4402 as relative to the end of the MMC partition. This can be useful if
4403 your board may be fitted with different MMC devices, which have
4404 different sizes for the MMC partitions, and you always want the
4405 environment placed at the very end of the partition, to leave the
4406 maximum possible space before it, to store other data.
4408 These two values are in units of bytes, but must be aligned to an
4409 MMC sector boundary.
4411 - CONFIG_ENV_OFFSET_REDUND (optional):
4413 Specifies a second storage area, of CONFIG_ENV_SIZE size, used to
4414 hold a redundant copy of the environment data. This provides a
4415 valid backup copy in case the other copy is corrupted, e.g. due
4416 to a power failure during a "saveenv" operation.
4418 This value may also be positive or negative; this is handled in the
4419 same way as CONFIG_ENV_OFFSET.
4421 This value is also in units of bytes, but must also be aligned to
4422 an MMC sector boundary.
4424 - CONFIG_ENV_SIZE_REDUND (optional):
4426 This value need not be set, even when CONFIG_ENV_OFFSET_REDUND is
4427 set. If this value is set, it must be set to the same value as
4430 - CONFIG_SYS_SPI_INIT_OFFSET
4432 Defines offset to the initial SPI buffer area in DPRAM. The
4433 area is used at an early stage (ROM part) if the environment
4434 is configured to reside in the SPI EEPROM: We need a 520 byte
4435 scratch DPRAM area. It is used between the two initialization
4436 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems
4437 to be a good choice since it makes it far enough from the
4438 start of the data area as well as from the stack pointer.
4440 Please note that the environment is read-only until the monitor
4441 has been relocated to RAM and a RAM copy of the environment has been
4442 created; also, when using EEPROM you will have to use getenv_f()
4443 until then to read environment variables.
4445 The environment is protected by a CRC32 checksum. Before the monitor
4446 is relocated into RAM, as a result of a bad CRC you will be working
4447 with the compiled-in default environment - *silently*!!! [This is
4448 necessary, because the first environment variable we need is the
4449 "baudrate" setting for the console - if we have a bad CRC, we don't
4450 have any device yet where we could complain.]
4452 Note: once the monitor has been relocated, then it will complain if
4453 the default environment is used; a new CRC is computed as soon as you
4454 use the "saveenv" command to store a valid environment.
4456 - CONFIG_SYS_FAULT_ECHO_LINK_DOWN:
4457 Echo the inverted Ethernet link state to the fault LED.
4459 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR
4460 also needs to be defined.
4462 - CONFIG_SYS_FAULT_MII_ADDR:
4463 MII address of the PHY to check for the Ethernet link state.
4465 - CONFIG_NS16550_MIN_FUNCTIONS:
4466 Define this if you desire to only have use of the NS16550_init
4467 and NS16550_putc functions for the serial driver located at
4468 drivers/serial/ns16550.c. This option is useful for saving
4469 space for already greatly restricted images, including but not
4470 limited to NAND_SPL configurations.
4472 - CONFIG_DISPLAY_BOARDINFO
4473 Display information about the board that U-Boot is running on
4474 when U-Boot starts up. The board function checkboard() is called
4477 - CONFIG_DISPLAY_BOARDINFO_LATE
4478 Similar to the previous option, but display this information
4479 later, once stdio is running and output goes to the LCD, if
4482 - CONFIG_BOARD_SIZE_LIMIT:
4483 Maximum size of the U-Boot image. When defined, the
4484 build system checks that the actual size does not
4487 Low Level (hardware related) configuration options:
4488 ---------------------------------------------------
4490 - CONFIG_SYS_CACHELINE_SIZE:
4491 Cache Line Size of the CPU.
4493 - CONFIG_SYS_DEFAULT_IMMR:
4494 Default address of the IMMR after system reset.
4496 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU,
4497 and RPXsuper) to be able to adjust the position of
4498 the IMMR register after a reset.
4500 - CONFIG_SYS_CCSRBAR_DEFAULT:
4501 Default (power-on reset) physical address of CCSR on Freescale
4504 - CONFIG_SYS_CCSRBAR:
4505 Virtual address of CCSR. On a 32-bit build, this is typically
4506 the same value as CONFIG_SYS_CCSRBAR_DEFAULT.
4508 CONFIG_SYS_DEFAULT_IMMR must also be set to this value,
4509 for cross-platform code that uses that macro instead.
4511 - CONFIG_SYS_CCSRBAR_PHYS:
4512 Physical address of CCSR. CCSR can be relocated to a new
4513 physical address, if desired. In this case, this macro should
4514 be set to that address. Otherwise, it should be set to the
4515 same value as CONFIG_SYS_CCSRBAR_DEFAULT. For example, CCSR
4516 is typically relocated on 36-bit builds. It is recommended
4517 that this macro be defined via the _HIGH and _LOW macros:
4519 #define CONFIG_SYS_CCSRBAR_PHYS ((CONFIG_SYS_CCSRBAR_PHYS_HIGH
4520 * 1ull) << 32 | CONFIG_SYS_CCSRBAR_PHYS_LOW)
4522 - CONFIG_SYS_CCSRBAR_PHYS_HIGH:
4523 Bits 33-36 of CONFIG_SYS_CCSRBAR_PHYS. This value is typically
4524 either 0 (32-bit build) or 0xF (36-bit build). This macro is
4525 used in assembly code, so it must not contain typecasts or
4526 integer size suffixes (e.g. "ULL").
4528 - CONFIG_SYS_CCSRBAR_PHYS_LOW:
4529 Lower 32-bits of CONFIG_SYS_CCSRBAR_PHYS. This macro is
4530 used in assembly code, so it must not contain typecasts or
4531 integer size suffixes (e.g. "ULL").
4533 - CONFIG_SYS_CCSR_DO_NOT_RELOCATE:
4534 If this macro is defined, then CONFIG_SYS_CCSRBAR_PHYS will be
4535 forced to a value that ensures that CCSR is not relocated.
4537 - Floppy Disk Support:
4538 CONFIG_SYS_FDC_DRIVE_NUMBER
4540 the default drive number (default value 0)
4542 CONFIG_SYS_ISA_IO_STRIDE
4544 defines the spacing between FDC chipset registers
4547 CONFIG_SYS_ISA_IO_OFFSET
4549 defines the offset of register from address. It
4550 depends on which part of the data bus is connected to
4551 the FDC chipset. (default value 0)
4553 If CONFIG_SYS_ISA_IO_STRIDE CONFIG_SYS_ISA_IO_OFFSET and
4554 CONFIG_SYS_FDC_DRIVE_NUMBER are undefined, they take their
4557 if CONFIG_SYS_FDC_HW_INIT is defined, then the function
4558 fdc_hw_init() is called at the beginning of the FDC
4559 setup. fdc_hw_init() must be provided by the board
4560 source code. It is used to make hardware dependant
4564 Most IDE controllers were designed to be connected with PCI
4565 interface. Only few of them were designed for AHB interface.
4566 When software is doing ATA command and data transfer to
4567 IDE devices through IDE-AHB controller, some additional
4568 registers accessing to these kind of IDE-AHB controller
4571 - CONFIG_SYS_IMMR: Physical address of the Internal Memory.
4572 DO NOT CHANGE unless you know exactly what you're
4573 doing! (11-4) [MPC8xx/82xx systems only]
4575 - CONFIG_SYS_INIT_RAM_ADDR:
4577 Start address of memory area that can be used for
4578 initial data and stack; please note that this must be
4579 writable memory that is working WITHOUT special
4580 initialization, i. e. you CANNOT use normal RAM which
4581 will become available only after programming the
4582 memory controller and running certain initialization
4585 U-Boot uses the following memory types:
4586 - MPC8xx and MPC8260: IMMR (internal memory of the CPU)
4587 - MPC824X: data cache
4588 - PPC4xx: data cache
4590 - CONFIG_SYS_GBL_DATA_OFFSET:
4592 Offset of the initial data structure in the memory
4593 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually
4594 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial
4595 data is located at the end of the available space
4596 (sometimes written as (CONFIG_SYS_INIT_RAM_SIZE -
4597 CONFIG_SYS_INIT_DATA_SIZE), and the initial stack is just
4598 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR +
4599 CONFIG_SYS_GBL_DATA_OFFSET) downward.
4602 On the MPC824X (or other systems that use the data
4603 cache for initial memory) the address chosen for
4604 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must
4605 point to an otherwise UNUSED address space between
4606 the top of RAM and the start of the PCI space.
4608 - CONFIG_SYS_SIUMCR: SIU Module Configuration (11-6)
4610 - CONFIG_SYS_SYPCR: System Protection Control (11-9)
4612 - CONFIG_SYS_TBSCR: Time Base Status and Control (11-26)
4614 - CONFIG_SYS_PISCR: Periodic Interrupt Status and Control (11-31)
4616 - CONFIG_SYS_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30)
4618 - CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27)
4620 - CONFIG_SYS_OR_TIMING_SDRAM:
4623 - CONFIG_SYS_MAMR_PTA:
4624 periodic timer for refresh
4626 - CONFIG_SYS_DER: Debug Event Register (37-47)
4628 - FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM,
4629 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP,
4630 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM,
4631 CONFIG_SYS_BR1_PRELIM:
4632 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
4634 - SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
4635 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM,
4636 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM:
4637 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
4639 - CONFIG_SYS_MAMR_PTA, CONFIG_SYS_MPTPR_2BK_4K, CONFIG_SYS_MPTPR_1BK_4K, CONFIG_SYS_MPTPR_2BK_8K,
4640 CONFIG_SYS_MPTPR_1BK_8K, CONFIG_SYS_MAMR_8COL, CONFIG_SYS_MAMR_9COL:
4641 Machine Mode Register and Memory Periodic Timer
4642 Prescaler definitions (SDRAM timing)
4644 - CONFIG_SYS_I2C_UCODE_PATCH, CONFIG_SYS_I2C_DPMEM_OFFSET [0x1FC0]:
4645 enable I2C microcode relocation patch (MPC8xx);
4646 define relocation offset in DPRAM [DSP2]
4648 - CONFIG_SYS_SMC_UCODE_PATCH, CONFIG_SYS_SMC_DPMEM_OFFSET [0x1FC0]:
4649 enable SMC microcode relocation patch (MPC8xx);
4650 define relocation offset in DPRAM [SMC1]
4652 - CONFIG_SYS_SPI_UCODE_PATCH, CONFIG_SYS_SPI_DPMEM_OFFSET [0x1FC0]:
4653 enable SPI microcode relocation patch (MPC8xx);
4654 define relocation offset in DPRAM [SCC4]
4656 - CONFIG_SYS_USE_OSCCLK:
4657 Use OSCM clock mode on MBX8xx board. Be careful,
4658 wrong setting might damage your board. Read
4659 doc/README.MBX before setting this variable!
4661 - CONFIG_SYS_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only)
4662 Offset of the bootmode word in DPRAM used by post
4663 (Power On Self Tests). This definition overrides
4664 #define'd default value in commproc.h resp.
4667 - CONFIG_SYS_PCI_SLV_MEM_LOCAL, CONFIG_SYS_PCI_SLV_MEM_BUS, CONFIG_SYS_PICMR0_MASK_ATTRIB,
4668 CONFIG_SYS_PCI_MSTR0_LOCAL, CONFIG_SYS_PCIMSK0_MASK, CONFIG_SYS_PCI_MSTR1_LOCAL,
4669 CONFIG_SYS_PCIMSK1_MASK, CONFIG_SYS_PCI_MSTR_MEM_LOCAL, CONFIG_SYS_PCI_MSTR_MEM_BUS,
4670 CONFIG_SYS_CPU_PCI_MEM_START, CONFIG_SYS_PCI_MSTR_MEM_SIZE, CONFIG_SYS_POCMR0_MASK_ATTRIB,
4671 CONFIG_SYS_PCI_MSTR_MEMIO_LOCAL, CONFIG_SYS_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START,
4672 CONFIG_SYS_PCI_MSTR_MEMIO_SIZE, CONFIG_SYS_POCMR1_MASK_ATTRIB, CONFIG_SYS_PCI_MSTR_IO_LOCAL,
4673 CONFIG_SYS_PCI_MSTR_IO_BUS, CONFIG_SYS_CPU_PCI_IO_START, CONFIG_SYS_PCI_MSTR_IO_SIZE,
4674 CONFIG_SYS_POCMR2_MASK_ATTRIB: (MPC826x only)
4675 Overrides the default PCI memory map in arch/powerpc/cpu/mpc8260/pci.c if set.
4677 - CONFIG_PCI_DISABLE_PCIE:
4678 Disable PCI-Express on systems where it is supported but not
4681 - CONFIG_PCI_ENUM_ONLY
4682 Only scan through and get the devices on the busses.
4683 Don't do any setup work, presumably because someone or
4684 something has already done it, and we don't need to do it
4685 a second time. Useful for platforms that are pre-booted
4686 by coreboot or similar.
4688 - CONFIG_PCI_INDIRECT_BRIDGE:
4689 Enable support for indirect PCI bridges.
4692 Chip has SRIO or not
4695 Board has SRIO 1 port available
4698 Board has SRIO 2 port available
4700 - CONFIG_SRIO_PCIE_BOOT_MASTER
4701 Board can support master function for Boot from SRIO and PCIE
4703 - CONFIG_SYS_SRIOn_MEM_VIRT:
4704 Virtual Address of SRIO port 'n' memory region
4706 - CONFIG_SYS_SRIOn_MEM_PHYS:
4707 Physical Address of SRIO port 'n' memory region
4709 - CONFIG_SYS_SRIOn_MEM_SIZE:
4710 Size of SRIO port 'n' memory region
4712 - CONFIG_SYS_NAND_BUSWIDTH_16BIT
4713 Defined to tell the NAND controller that the NAND chip is using
4715 Not all NAND drivers use this symbol.
4716 Example of drivers that use it:
4717 - drivers/mtd/nand/ndfc.c
4718 - drivers/mtd/nand/mxc_nand.c
4720 - CONFIG_SYS_NDFC_EBC0_CFG
4721 Sets the EBC0_CFG register for the NDFC. If not defined
4722 a default value will be used.
4725 Get DDR timing information from an I2C EEPROM. Common
4726 with pluggable memory modules such as SODIMMs
4729 I2C address of the SPD EEPROM
4731 - CONFIG_SYS_SPD_BUS_NUM
4732 If SPD EEPROM is on an I2C bus other than the first
4733 one, specify here. Note that the value must resolve
4734 to something your driver can deal with.
4736 - CONFIG_SYS_DDR_RAW_TIMING
4737 Get DDR timing information from other than SPD. Common with
4738 soldered DDR chips onboard without SPD. DDR raw timing
4739 parameters are extracted from datasheet and hard-coded into
4740 header files or board specific files.
4742 - CONFIG_FSL_DDR_INTERACTIVE
4743 Enable interactive DDR debugging. See doc/README.fsl-ddr.
4745 - CONFIG_SYS_83XX_DDR_USES_CS0
4746 Only for 83xx systems. If specified, then DDR should
4747 be configured using CS0 and CS1 instead of CS2 and CS3.
4749 - CONFIG_ETHER_ON_FEC[12]
4750 Define to enable FEC[12] on a 8xx series processor.
4752 - CONFIG_FEC[12]_PHY
4753 Define to the hardcoded PHY address which corresponds
4754 to the given FEC; i. e.
4755 #define CONFIG_FEC1_PHY 4
4756 means that the PHY with address 4 is connected to FEC1
4758 When set to -1, means to probe for first available.
4760 - CONFIG_FEC[12]_PHY_NORXERR
4761 The PHY does not have a RXERR line (RMII only).
4762 (so program the FEC to ignore it).
4765 Enable RMII mode for all FECs.
4766 Note that this is a global option, we can't
4767 have one FEC in standard MII mode and another in RMII mode.
4769 - CONFIG_CRC32_VERIFY
4770 Add a verify option to the crc32 command.
4773 => crc32 -v <address> <count> <crc32>
4775 Where address/count indicate a memory area
4776 and crc32 is the correct crc32 which the
4780 Add the "loopw" memory command. This only takes effect if
4781 the memory commands are activated globally (CONFIG_CMD_MEM).
4784 Add the "mdc" and "mwc" memory commands. These are cyclic
4789 This command will print 4 bytes (10,11,12,13) each 500 ms.
4791 => mwc.l 100 12345678 10
4792 This command will write 12345678 to address 100 all 10 ms.
4794 This only takes effect if the memory commands are activated
4795 globally (CONFIG_CMD_MEM).
4797 - CONFIG_SKIP_LOWLEVEL_INIT
4798 [ARM, NDS32, MIPS only] If this variable is defined, then certain
4799 low level initializations (like setting up the memory
4800 controller) are omitted and/or U-Boot does not
4801 relocate itself into RAM.
4803 Normally this variable MUST NOT be defined. The only
4804 exception is when U-Boot is loaded (to RAM) by some
4805 other boot loader or by a debugger which performs
4806 these initializations itself.
4809 Modifies the behaviour of start.S when compiling a loader
4810 that is executed before the actual U-Boot. E.g. when
4811 compiling a NAND SPL.
4814 Modifies the behaviour of start.S when compiling a loader
4815 that is executed after the SPL and before the actual U-Boot.
4816 It is loaded by the SPL.
4818 - CONFIG_SYS_MPC85XX_NO_RESETVEC
4819 Only for 85xx systems. If this variable is specified, the section
4820 .resetvec is not kept and the section .bootpg is placed in the
4821 previous 4k of the .text section.
4823 - CONFIG_ARCH_MAP_SYSMEM
4824 Generally U-Boot (and in particular the md command) uses
4825 effective address. It is therefore not necessary to regard
4826 U-Boot address as virtual addresses that need to be translated
4827 to physical addresses. However, sandbox requires this, since
4828 it maintains its own little RAM buffer which contains all
4829 addressable memory. This option causes some memory accesses
4830 to be mapped through map_sysmem() / unmap_sysmem().
4832 - CONFIG_USE_ARCH_MEMCPY
4833 CONFIG_USE_ARCH_MEMSET
4834 If these options are used a optimized version of memcpy/memset will
4835 be used if available. These functions may be faster under some
4836 conditions but may increase the binary size.
4838 - CONFIG_X86_RESET_VECTOR
4839 If defined, the x86 reset vector code is included. This is not
4840 needed when U-Boot is running from Coreboot.
4843 Defines the MPU clock speed (in MHz).
4845 NOTE : currently only supported on AM335x platforms.
4847 - CONFIG_SPL_AM33XX_ENABLE_RTC32K_OSC:
4848 Enables the RTC32K OSC on AM33xx based plattforms
4850 - CONFIG_SYS_NAND_NO_SUBPAGE_WRITE
4851 Option to disable subpage write in NAND driver
4852 driver that uses this:
4853 drivers/mtd/nand/davinci_nand.c
4855 Freescale QE/FMAN Firmware Support:
4856 -----------------------------------
4858 The Freescale QUICCEngine (QE) and Frame Manager (FMAN) both support the
4859 loading of "firmware", which is encoded in the QE firmware binary format.
4860 This firmware often needs to be loaded during U-Boot booting, so macros
4861 are used to identify the storage device (NOR flash, SPI, etc) and the address
4864 - CONFIG_SYS_FMAN_FW_ADDR
4865 The address in the storage device where the FMAN microcode is located. The
4866 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
4869 - CONFIG_SYS_QE_FW_ADDR
4870 The address in the storage device where the QE microcode is located. The
4871 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
4874 - CONFIG_SYS_QE_FMAN_FW_LENGTH
4875 The maximum possible size of the firmware. The firmware binary format
4876 has a field that specifies the actual size of the firmware, but it
4877 might not be possible to read any part of the firmware unless some
4878 local storage is allocated to hold the entire firmware first.
4880 - CONFIG_SYS_QE_FMAN_FW_IN_NOR
4881 Specifies that QE/FMAN firmware is located in NOR flash, mapped as
4882 normal addressable memory via the LBC. CONFIG_SYS_FMAN_FW_ADDR is the
4883 virtual address in NOR flash.
4885 - CONFIG_SYS_QE_FMAN_FW_IN_NAND
4886 Specifies that QE/FMAN firmware is located in NAND flash.
4887 CONFIG_SYS_FMAN_FW_ADDR is the offset within NAND flash.
4889 - CONFIG_SYS_QE_FMAN_FW_IN_MMC
4890 Specifies that QE/FMAN firmware is located on the primary SD/MMC
4891 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
4893 - CONFIG_SYS_QE_FMAN_FW_IN_SPIFLASH
4894 Specifies that QE/FMAN firmware is located on the primary SPI
4895 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
4897 - CONFIG_SYS_QE_FMAN_FW_IN_REMOTE
4898 Specifies that QE/FMAN firmware is located in the remote (master)
4899 memory space. CONFIG_SYS_FMAN_FW_ADDR is a virtual address which
4900 can be mapped from slave TLB->slave LAW->slave SRIO or PCIE outbound
4901 window->master inbound window->master LAW->the ucode address in
4902 master's memory space.
4904 Freescale Layerscape Management Complex Firmware Support:
4905 ---------------------------------------------------------
4906 The Freescale Layerscape Management Complex (MC) supports the loading of
4908 This firmware often needs to be loaded during U-Boot booting, so macros
4909 are used to identify the storage device (NOR flash, SPI, etc) and the address
4912 - CONFIG_FSL_MC_ENET
4913 Enable the MC driver for Layerscape SoCs.
4915 - CONFIG_SYS_LS_MC_FW_ADDR
4916 The address in the storage device where the firmware is located. The
4917 meaning of this address depends on which CONFIG_SYS_LS_MC_FW_IN_xxx macro
4920 - CONFIG_SYS_LS_MC_FW_LENGTH
4921 The maximum possible size of the firmware. The firmware binary format
4922 has a field that specifies the actual size of the firmware, but it
4923 might not be possible to read any part of the firmware unless some
4924 local storage is allocated to hold the entire firmware first.
4926 - CONFIG_SYS_LS_MC_FW_IN_NOR
4927 Specifies that MC firmware is located in NOR flash, mapped as
4928 normal addressable memory via the LBC. CONFIG_SYS_LS_MC_FW_ADDR is the
4929 virtual address in NOR flash.
4931 Building the Software:
4932 ======================
4934 Building U-Boot has been tested in several native build environments
4935 and in many different cross environments. Of course we cannot support
4936 all possibly existing versions of cross development tools in all
4937 (potentially obsolete) versions. In case of tool chain problems we
4938 recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK)
4939 which is extensively used to build and test U-Boot.
4941 If you are not using a native environment, it is assumed that you
4942 have GNU cross compiling tools available in your path. In this case,
4943 you must set the environment variable CROSS_COMPILE in your shell.
4944 Note that no changes to the Makefile or any other source files are
4945 necessary. For example using the ELDK on a 4xx CPU, please enter:
4947 $ CROSS_COMPILE=ppc_4xx-
4948 $ export CROSS_COMPILE
4950 Note: If you wish to generate Windows versions of the utilities in
4951 the tools directory you can use the MinGW toolchain
4952 (http://www.mingw.org). Set your HOST tools to the MinGW
4953 toolchain and execute 'make tools'. For example:
4955 $ make HOSTCC=i586-mingw32msvc-gcc HOSTSTRIP=i586-mingw32msvc-strip tools
4957 Binaries such as tools/mkimage.exe will be created which can
4958 be executed on computers running Windows.
4960 U-Boot is intended to be simple to build. After installing the
4961 sources you must configure U-Boot for one specific board type. This
4966 where "NAME_defconfig" is the name of one of the existing configu-
4967 rations; see boards.cfg for supported names.
4969 Note: for some board special configuration names may exist; check if
4970 additional information is available from the board vendor; for
4971 instance, the TQM823L systems are available without (standard)
4972 or with LCD support. You can select such additional "features"
4973 when choosing the configuration, i. e.
4975 make TQM823L_defconfig
4976 - will configure for a plain TQM823L, i. e. no LCD support
4978 make TQM823L_LCD_defconfig
4979 - will configure for a TQM823L with U-Boot console on LCD
4984 Finally, type "make all", and you should get some working U-Boot
4985 images ready for download to / installation on your system:
4987 - "u-boot.bin" is a raw binary image
4988 - "u-boot" is an image in ELF binary format
4989 - "u-boot.srec" is in Motorola S-Record format
4991 By default the build is performed locally and the objects are saved
4992 in the source directory. One of the two methods can be used to change
4993 this behavior and build U-Boot to some external directory:
4995 1. Add O= to the make command line invocations:
4997 make O=/tmp/build distclean
4998 make O=/tmp/build NAME_defconfig
4999 make O=/tmp/build all
5001 2. Set environment variable BUILD_DIR to point to the desired location:
5003 export BUILD_DIR=/tmp/build
5008 Note that the command line "O=" setting overrides the BUILD_DIR environment
5012 Please be aware that the Makefiles assume you are using GNU make, so
5013 for instance on NetBSD you might need to use "gmake" instead of
5017 If the system board that you have is not listed, then you will need
5018 to port U-Boot to your hardware platform. To do this, follow these
5021 1. Add a new configuration option for your board to the toplevel
5022 "boards.cfg" file, using the existing entries as examples.
5023 Follow the instructions there to keep the boards in order.
5024 2. Create a new directory to hold your board specific code. Add any
5025 files you need. In your board directory, you will need at least
5026 the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds".
5027 3. Create a new configuration file "include/configs/<board>.h" for
5029 3. If you're porting U-Boot to a new CPU, then also create a new
5030 directory to hold your CPU specific code. Add any files you need.
5031 4. Run "make <board>_defconfig" with your new name.
5032 5. Type "make", and you should get a working "u-boot.srec" file
5033 to be installed on your target system.
5034 6. Debug and solve any problems that might arise.
5035 [Of course, this last step is much harder than it sounds.]
5038 Testing of U-Boot Modifications, Ports to New Hardware, etc.:
5039 ==============================================================
5041 If you have modified U-Boot sources (for instance added a new board
5042 or support for new devices, a new CPU, etc.) you are expected to
5043 provide feedback to the other developers. The feedback normally takes
5044 the form of a "patch", i. e. a context diff against a certain (latest
5045 official or latest in the git repository) version of U-Boot sources.
5047 But before you submit such a patch, please verify that your modifi-
5048 cation did not break existing code. At least make sure that *ALL* of
5049 the supported boards compile WITHOUT ANY compiler warnings. To do so,
5050 just run the "MAKEALL" script, which will configure and build U-Boot
5051 for ALL supported system. Be warned, this will take a while. You can
5052 select which (cross) compiler to use by passing a `CROSS_COMPILE'
5053 environment variable to the script, i. e. to use the ELDK cross tools
5056 CROSS_COMPILE=ppc_8xx- MAKEALL
5058 or to build on a native PowerPC system you can type
5060 CROSS_COMPILE=' ' MAKEALL
5062 When using the MAKEALL script, the default behaviour is to build
5063 U-Boot in the source directory. This location can be changed by
5064 setting the BUILD_DIR environment variable. Also, for each target
5065 built, the MAKEALL script saves two log files (<target>.ERR and
5066 <target>.MAKEALL) in the <source dir>/LOG directory. This default
5067 location can be changed by setting the MAKEALL_LOGDIR environment
5068 variable. For example:
5070 export BUILD_DIR=/tmp/build
5071 export MAKEALL_LOGDIR=/tmp/log
5072 CROSS_COMPILE=ppc_8xx- MAKEALL
5074 With the above settings build objects are saved in the /tmp/build,
5075 log files are saved in the /tmp/log and the source tree remains clean
5076 during the whole build process.
5079 See also "U-Boot Porting Guide" below.
5082 Monitor Commands - Overview:
5083 ============================
5085 go - start application at address 'addr'
5086 run - run commands in an environment variable
5087 bootm - boot application image from memory
5088 bootp - boot image via network using BootP/TFTP protocol
5089 bootz - boot zImage from memory
5090 tftpboot- boot image via network using TFTP protocol
5091 and env variables "ipaddr" and "serverip"
5092 (and eventually "gatewayip")
5093 tftpput - upload a file via network using TFTP protocol
5094 rarpboot- boot image via network using RARP/TFTP protocol
5095 diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
5096 loads - load S-Record file over serial line
5097 loadb - load binary file over serial line (kermit mode)
5099 mm - memory modify (auto-incrementing)
5100 nm - memory modify (constant address)
5101 mw - memory write (fill)
5103 cmp - memory compare
5104 crc32 - checksum calculation
5105 i2c - I2C sub-system
5106 sspi - SPI utility commands
5107 base - print or set address offset
5108 printenv- print environment variables
5109 setenv - set environment variables
5110 saveenv - save environment variables to persistent storage
5111 protect - enable or disable FLASH write protection
5112 erase - erase FLASH memory
5113 flinfo - print FLASH memory information
5114 nand - NAND memory operations (see doc/README.nand)
5115 bdinfo - print Board Info structure
5116 iminfo - print header information for application image
5117 coninfo - print console devices and informations
5118 ide - IDE sub-system
5119 loop - infinite loop on address range
5120 loopw - infinite write loop on address range
5121 mtest - simple RAM test
5122 icache - enable or disable instruction cache
5123 dcache - enable or disable data cache
5124 reset - Perform RESET of the CPU
5125 echo - echo args to console
5126 version - print monitor version
5127 help - print online help
5128 ? - alias for 'help'
5131 Monitor Commands - Detailed Description:
5132 ========================================
5136 For now: just type "help <command>".
5139 Environment Variables:
5140 ======================
5142 U-Boot supports user configuration using Environment Variables which
5143 can be made persistent by saving to Flash memory.
5145 Environment Variables are set using "setenv", printed using
5146 "printenv", and saved to Flash using "saveenv". Using "setenv"
5147 without a value can be used to delete a variable from the
5148 environment. As long as you don't save the environment you are
5149 working with an in-memory copy. In case the Flash area containing the
5150 environment is erased by accident, a default environment is provided.
5152 Some configuration options can be set using Environment Variables.
5154 List of environment variables (most likely not complete):
5156 baudrate - see CONFIG_BAUDRATE
5158 bootdelay - see CONFIG_BOOTDELAY
5160 bootcmd - see CONFIG_BOOTCOMMAND
5162 bootargs - Boot arguments when booting an RTOS image
5164 bootfile - Name of the image to load with TFTP
5166 bootm_low - Memory range available for image processing in the bootm
5167 command can be restricted. This variable is given as
5168 a hexadecimal number and defines lowest address allowed
5169 for use by the bootm command. See also "bootm_size"
5170 environment variable. Address defined by "bootm_low" is
5171 also the base of the initial memory mapping for the Linux
5172 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ and
5175 bootm_mapsize - Size of the initial memory mapping for the Linux kernel.
5176 This variable is given as a hexadecimal number and it
5177 defines the size of the memory region starting at base
5178 address bootm_low that is accessible by the Linux kernel
5179 during early boot. If unset, CONFIG_SYS_BOOTMAPSZ is used
5180 as the default value if it is defined, and bootm_size is
5183 bootm_size - Memory range available for image processing in the bootm
5184 command can be restricted. This variable is given as
5185 a hexadecimal number and defines the size of the region
5186 allowed for use by the bootm command. See also "bootm_low"
5187 environment variable.
5189 updatefile - Location of the software update file on a TFTP server, used
5190 by the automatic software update feature. Please refer to
5191 documentation in doc/README.update for more details.
5193 autoload - if set to "no" (any string beginning with 'n'),
5194 "bootp" will just load perform a lookup of the
5195 configuration from the BOOTP server, but not try to
5196 load any image using TFTP
5198 autostart - if set to "yes", an image loaded using the "bootp",
5199 "rarpboot", "tftpboot" or "diskboot" commands will
5200 be automatically started (by internally calling
5203 If set to "no", a standalone image passed to the
5204 "bootm" command will be copied to the load address
5205 (and eventually uncompressed), but NOT be started.
5206 This can be used to load and uncompress arbitrary
5209 fdt_high - if set this restricts the maximum address that the
5210 flattened device tree will be copied into upon boot.
5211 For example, if you have a system with 1 GB memory
5212 at physical address 0x10000000, while Linux kernel
5213 only recognizes the first 704 MB as low memory, you
5214 may need to set fdt_high as 0x3C000000 to have the
5215 device tree blob be copied to the maximum address
5216 of the 704 MB low memory, so that Linux kernel can
5217 access it during the boot procedure.
5219 If this is set to the special value 0xFFFFFFFF then
5220 the fdt will not be copied at all on boot. For this
5221 to work it must reside in writable memory, have
5222 sufficient padding on the end of it for u-boot to
5223 add the information it needs into it, and the memory
5224 must be accessible by the kernel.
5226 fdtcontroladdr- if set this is the address of the control flattened
5227 device tree used by U-Boot when CONFIG_OF_CONTROL is
5230 i2cfast - (PPC405GP|PPC405EP only)
5231 if set to 'y' configures Linux I2C driver for fast
5232 mode (400kHZ). This environment variable is used in
5233 initialization code. So, for changes to be effective
5234 it must be saved and board must be reset.
5236 initrd_high - restrict positioning of initrd images:
5237 If this variable is not set, initrd images will be
5238 copied to the highest possible address in RAM; this
5239 is usually what you want since it allows for
5240 maximum initrd size. If for some reason you want to
5241 make sure that the initrd image is loaded below the
5242 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment
5243 variable to a value of "no" or "off" or "0".
5244 Alternatively, you can set it to a maximum upper
5245 address to use (U-Boot will still check that it
5246 does not overwrite the U-Boot stack and data).
5248 For instance, when you have a system with 16 MB
5249 RAM, and want to reserve 4 MB from use by Linux,
5250 you can do this by adding "mem=12M" to the value of
5251 the "bootargs" variable. However, now you must make
5252 sure that the initrd image is placed in the first
5253 12 MB as well - this can be done with
5255 setenv initrd_high 00c00000
5257 If you set initrd_high to 0xFFFFFFFF, this is an
5258 indication to U-Boot that all addresses are legal
5259 for the Linux kernel, including addresses in flash
5260 memory. In this case U-Boot will NOT COPY the
5261 ramdisk at all. This may be useful to reduce the
5262 boot time on your system, but requires that this
5263 feature is supported by your Linux kernel.
5265 ipaddr - IP address; needed for tftpboot command
5267 loadaddr - Default load address for commands like "bootp",
5268 "rarpboot", "tftpboot", "loadb" or "diskboot"
5270 loads_echo - see CONFIG_LOADS_ECHO
5272 serverip - TFTP server IP address; needed for tftpboot command
5274 bootretry - see CONFIG_BOOT_RETRY_TIME
5276 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
5278 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
5280 ethprime - controls which interface is used first.
5282 ethact - controls which interface is currently active.
5283 For example you can do the following
5285 => setenv ethact FEC
5286 => ping 192.168.0.1 # traffic sent on FEC
5287 => setenv ethact SCC
5288 => ping 10.0.0.1 # traffic sent on SCC
5290 ethrotate - When set to "no" U-Boot does not go through all
5291 available network interfaces.
5292 It just stays at the currently selected interface.
5294 netretry - When set to "no" each network operation will
5295 either succeed or fail without retrying.
5296 When set to "once" the network operation will
5297 fail when all the available network interfaces
5298 are tried once without success.
5299 Useful on scripts which control the retry operation
5302 npe_ucode - set load address for the NPE microcode
5304 silent_linux - If set then linux will be told to boot silently, by
5305 changing the console to be empty. If "yes" it will be
5306 made silent. If "no" it will not be made silent. If
5307 unset, then it will be made silent if the U-Boot console
5310 tftpsrcport - If this is set, the value is used for TFTP's
5313 tftpdstport - If this is set, the value is used for TFTP's UDP
5314 destination port instead of the Well Know Port 69.
5316 tftpblocksize - Block size to use for TFTP transfers; if not set,
5317 we use the TFTP server's default block size
5319 tftptimeout - Retransmission timeout for TFTP packets (in milli-
5320 seconds, minimum value is 1000 = 1 second). Defines
5321 when a packet is considered to be lost so it has to
5322 be retransmitted. The default is 5000 = 5 seconds.
5323 Lowering this value may make downloads succeed
5324 faster in networks with high packet loss rates or
5325 with unreliable TFTP servers.
5327 vlan - When set to a value < 4095 the traffic over
5328 Ethernet is encapsulated/received over 802.1q
5331 The following image location variables contain the location of images
5332 used in booting. The "Image" column gives the role of the image and is
5333 not an environment variable name. The other columns are environment
5334 variable names. "File Name" gives the name of the file on a TFTP
5335 server, "RAM Address" gives the location in RAM the image will be
5336 loaded to, and "Flash Location" gives the image's address in NOR
5337 flash or offset in NAND flash.
5339 *Note* - these variables don't have to be defined for all boards, some
5340 boards currenlty use other variables for these purposes, and some
5341 boards use these variables for other purposes.
5343 Image File Name RAM Address Flash Location
5344 ----- --------- ----------- --------------
5345 u-boot u-boot u-boot_addr_r u-boot_addr
5346 Linux kernel bootfile kernel_addr_r kernel_addr
5347 device tree blob fdtfile fdt_addr_r fdt_addr
5348 ramdisk ramdiskfile ramdisk_addr_r ramdisk_addr
5350 The following environment variables may be used and automatically
5351 updated by the network boot commands ("bootp" and "rarpboot"),
5352 depending the information provided by your boot server:
5354 bootfile - see above
5355 dnsip - IP address of your Domain Name Server
5356 dnsip2 - IP address of your secondary Domain Name Server
5357 gatewayip - IP address of the Gateway (Router) to use
5358 hostname - Target hostname
5360 netmask - Subnet Mask
5361 rootpath - Pathname of the root filesystem on the NFS server
5362 serverip - see above
5365 There are two special Environment Variables:
5367 serial# - contains hardware identification information such
5368 as type string and/or serial number
5369 ethaddr - Ethernet address
5371 These variables can be set only once (usually during manufacturing of
5372 the board). U-Boot refuses to delete or overwrite these variables
5373 once they have been set once.
5376 Further special Environment Variables:
5378 ver - Contains the U-Boot version string as printed
5379 with the "version" command. This variable is
5380 readonly (see CONFIG_VERSION_VARIABLE).
5383 Please note that changes to some configuration parameters may take
5384 only effect after the next boot (yes, that's just like Windoze :-).
5387 Callback functions for environment variables:
5388 ---------------------------------------------
5390 For some environment variables, the behavior of u-boot needs to change
5391 when their values are changed. This functionailty allows functions to
5392 be associated with arbitrary variables. On creation, overwrite, or
5393 deletion, the callback will provide the opportunity for some side
5394 effect to happen or for the change to be rejected.
5396 The callbacks are named and associated with a function using the
5397 U_BOOT_ENV_CALLBACK macro in your board or driver code.
5399 These callbacks are associated with variables in one of two ways. The
5400 static list can be added to by defining CONFIG_ENV_CALLBACK_LIST_STATIC
5401 in the board configuration to a string that defines a list of
5402 associations. The list must be in the following format:
5404 entry = variable_name[:callback_name]
5407 If the callback name is not specified, then the callback is deleted.
5408 Spaces are also allowed anywhere in the list.
5410 Callbacks can also be associated by defining the ".callbacks" variable
5411 with the same list format above. Any association in ".callbacks" will
5412 override any association in the static list. You can define
5413 CONFIG_ENV_CALLBACK_LIST_DEFAULT to a list (string) to define the
5414 ".callbacks" envirnoment variable in the default or embedded environment.
5417 Command Line Parsing:
5418 =====================
5420 There are two different command line parsers available with U-Boot:
5421 the old "simple" one, and the much more powerful "hush" shell:
5423 Old, simple command line parser:
5424 --------------------------------
5426 - supports environment variables (through setenv / saveenv commands)
5427 - several commands on one line, separated by ';'
5428 - variable substitution using "... ${name} ..." syntax
5429 - special characters ('$', ';') can be escaped by prefixing with '\',
5431 setenv bootcmd bootm \${address}
5432 - You can also escape text by enclosing in single apostrophes, for example:
5433 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
5438 - similar to Bourne shell, with control structures like
5439 if...then...else...fi, for...do...done; while...do...done,
5440 until...do...done, ...
5441 - supports environment ("global") variables (through setenv / saveenv
5442 commands) and local shell variables (through standard shell syntax
5443 "name=value"); only environment variables can be used with "run"
5449 (1) If a command line (or an environment variable executed by a "run"
5450 command) contains several commands separated by semicolon, and
5451 one of these commands fails, then the remaining commands will be
5454 (2) If you execute several variables with one call to run (i. e.
5455 calling run with a list of variables as arguments), any failing
5456 command will cause "run" to terminate, i. e. the remaining
5457 variables are not executed.
5459 Note for Redundant Ethernet Interfaces:
5460 =======================================
5462 Some boards come with redundant Ethernet interfaces; U-Boot supports
5463 such configurations and is capable of automatic selection of a
5464 "working" interface when needed. MAC assignment works as follows:
5466 Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
5467 MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
5468 "eth1addr" (=>eth1), "eth2addr", ...
5470 If the network interface stores some valid MAC address (for instance
5471 in SROM), this is used as default address if there is NO correspon-
5472 ding setting in the environment; if the corresponding environment
5473 variable is set, this overrides the settings in the card; that means:
5475 o If the SROM has a valid MAC address, and there is no address in the
5476 environment, the SROM's address is used.
5478 o If there is no valid address in the SROM, and a definition in the
5479 environment exists, then the value from the environment variable is
5482 o If both the SROM and the environment contain a MAC address, and
5483 both addresses are the same, this MAC address is used.
5485 o If both the SROM and the environment contain a MAC address, and the
5486 addresses differ, the value from the environment is used and a
5489 o If neither SROM nor the environment contain a MAC address, an error
5492 If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses
5493 will be programmed into hardware as part of the initialization process. This
5494 may be skipped by setting the appropriate 'ethmacskip' environment variable.
5495 The naming convention is as follows:
5496 "ethmacskip" (=>eth0), "eth1macskip" (=>eth1) etc.
5501 U-Boot is capable of booting (and performing other auxiliary operations on)
5502 images in two formats:
5504 New uImage format (FIT)
5505 -----------------------
5507 Flexible and powerful format based on Flattened Image Tree -- FIT (similar
5508 to Flattened Device Tree). It allows the use of images with multiple
5509 components (several kernels, ramdisks, etc.), with contents protected by
5510 SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory.
5516 Old image format is based on binary files which can be basically anything,
5517 preceded by a special header; see the definitions in include/image.h for
5518 details; basically, the header defines the following image properties:
5520 * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
5521 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
5522 LynxOS, pSOS, QNX, RTEMS, INTEGRITY;
5523 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS,
5525 * Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86,
5526 IA64, MIPS, NDS32, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
5527 Currently supported: ARM, AVR32, Intel x86, MIPS, NDS32, Nios II, PowerPC).
5528 * Compression Type (uncompressed, gzip, bzip2)
5534 The header is marked by a special Magic Number, and both the header
5535 and the data portions of the image are secured against corruption by
5542 Although U-Boot should support any OS or standalone application
5543 easily, the main focus has always been on Linux during the design of
5546 U-Boot includes many features that so far have been part of some
5547 special "boot loader" code within the Linux kernel. Also, any
5548 "initrd" images to be used are no longer part of one big Linux image;
5549 instead, kernel and "initrd" are separate images. This implementation
5550 serves several purposes:
5552 - the same features can be used for other OS or standalone
5553 applications (for instance: using compressed images to reduce the
5554 Flash memory footprint)
5556 - it becomes much easier to port new Linux kernel versions because
5557 lots of low-level, hardware dependent stuff are done by U-Boot
5559 - the same Linux kernel image can now be used with different "initrd"
5560 images; of course this also means that different kernel images can
5561 be run with the same "initrd". This makes testing easier (you don't
5562 have to build a new "zImage.initrd" Linux image when you just
5563 change a file in your "initrd"). Also, a field-upgrade of the
5564 software is easier now.
5570 Porting Linux to U-Boot based systems:
5571 ---------------------------------------
5573 U-Boot cannot save you from doing all the necessary modifications to
5574 configure the Linux device drivers for use with your target hardware
5575 (no, we don't intend to provide a full virtual machine interface to
5578 But now you can ignore ALL boot loader code (in arch/powerpc/mbxboot).
5580 Just make sure your machine specific header file (for instance
5581 include/asm-ppc/tqm8xx.h) includes the same definition of the Board
5582 Information structure as we define in include/asm-<arch>/u-boot.h,
5583 and make sure that your definition of IMAP_ADDR uses the same value
5584 as your U-Boot configuration in CONFIG_SYS_IMMR.
5586 Note that U-Boot now has a driver model, a unified model for drivers.
5587 If you are adding a new driver, plumb it into driver model. If there
5588 is no uclass available, you are encouraged to create one. See
5592 Configuring the Linux kernel:
5593 -----------------------------
5595 No specific requirements for U-Boot. Make sure you have some root
5596 device (initial ramdisk, NFS) for your target system.
5599 Building a Linux Image:
5600 -----------------------
5602 With U-Boot, "normal" build targets like "zImage" or "bzImage" are
5603 not used. If you use recent kernel source, a new build target
5604 "uImage" will exist which automatically builds an image usable by
5605 U-Boot. Most older kernels also have support for a "pImage" target,
5606 which was introduced for our predecessor project PPCBoot and uses a
5607 100% compatible format.
5611 make TQM850L_defconfig
5616 The "uImage" build target uses a special tool (in 'tools/mkimage') to
5617 encapsulate a compressed Linux kernel image with header information,
5618 CRC32 checksum etc. for use with U-Boot. This is what we are doing:
5620 * build a standard "vmlinux" kernel image (in ELF binary format):
5622 * convert the kernel into a raw binary image:
5624 ${CROSS_COMPILE}-objcopy -O binary \
5625 -R .note -R .comment \
5626 -S vmlinux linux.bin
5628 * compress the binary image:
5632 * package compressed binary image for U-Boot:
5634 mkimage -A ppc -O linux -T kernel -C gzip \
5635 -a 0 -e 0 -n "Linux Kernel Image" \
5636 -d linux.bin.gz uImage
5639 The "mkimage" tool can also be used to create ramdisk images for use
5640 with U-Boot, either separated from the Linux kernel image, or
5641 combined into one file. "mkimage" encapsulates the images with a 64
5642 byte header containing information about target architecture,
5643 operating system, image type, compression method, entry points, time
5644 stamp, CRC32 checksums, etc.
5646 "mkimage" can be called in two ways: to verify existing images and
5647 print the header information, or to build new images.
5649 In the first form (with "-l" option) mkimage lists the information
5650 contained in the header of an existing U-Boot image; this includes
5651 checksum verification:
5653 tools/mkimage -l image
5654 -l ==> list image header information
5656 The second form (with "-d" option) is used to build a U-Boot image
5657 from a "data file" which is used as image payload:
5659 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
5660 -n name -d data_file image
5661 -A ==> set architecture to 'arch'
5662 -O ==> set operating system to 'os'
5663 -T ==> set image type to 'type'
5664 -C ==> set compression type 'comp'
5665 -a ==> set load address to 'addr' (hex)
5666 -e ==> set entry point to 'ep' (hex)
5667 -n ==> set image name to 'name'
5668 -d ==> use image data from 'datafile'
5670 Right now, all Linux kernels for PowerPC systems use the same load
5671 address (0x00000000), but the entry point address depends on the
5674 - 2.2.x kernels have the entry point at 0x0000000C,
5675 - 2.3.x and later kernels have the entry point at 0x00000000.
5677 So a typical call to build a U-Boot image would read:
5679 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
5680 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
5681 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz \
5682 > examples/uImage.TQM850L
5683 Image Name: 2.4.4 kernel for TQM850L
5684 Created: Wed Jul 19 02:34:59 2000
5685 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5686 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
5687 Load Address: 0x00000000
5688 Entry Point: 0x00000000
5690 To verify the contents of the image (or check for corruption):
5692 -> tools/mkimage -l examples/uImage.TQM850L
5693 Image Name: 2.4.4 kernel for TQM850L
5694 Created: Wed Jul 19 02:34:59 2000
5695 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5696 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
5697 Load Address: 0x00000000
5698 Entry Point: 0x00000000
5700 NOTE: for embedded systems where boot time is critical you can trade
5701 speed for memory and install an UNCOMPRESSED image instead: this
5702 needs more space in Flash, but boots much faster since it does not
5703 need to be uncompressed:
5705 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz
5706 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
5707 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
5708 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux \
5709 > examples/uImage.TQM850L-uncompressed
5710 Image Name: 2.4.4 kernel for TQM850L
5711 Created: Wed Jul 19 02:34:59 2000
5712 Image Type: PowerPC Linux Kernel Image (uncompressed)
5713 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
5714 Load Address: 0x00000000
5715 Entry Point: 0x00000000
5718 Similar you can build U-Boot images from a 'ramdisk.image.gz' file
5719 when your kernel is intended to use an initial ramdisk:
5721 -> tools/mkimage -n 'Simple Ramdisk Image' \
5722 > -A ppc -O linux -T ramdisk -C gzip \
5723 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
5724 Image Name: Simple Ramdisk Image
5725 Created: Wed Jan 12 14:01:50 2000
5726 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5727 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
5728 Load Address: 0x00000000
5729 Entry Point: 0x00000000
5731 The "dumpimage" is a tool to disassemble images built by mkimage. Its "-i"
5732 option performs the converse operation of the mkimage's second form (the "-d"
5733 option). Given an image built by mkimage, the dumpimage extracts a "data file"
5736 tools/dumpimage -i image -p position data_file
5737 -i ==> extract from the 'image' a specific 'data_file', \
5738 indexed by 'position'
5741 Installing a Linux Image:
5742 -------------------------
5744 To downloading a U-Boot image over the serial (console) interface,
5745 you must convert the image to S-Record format:
5747 objcopy -I binary -O srec examples/image examples/image.srec
5749 The 'objcopy' does not understand the information in the U-Boot
5750 image header, so the resulting S-Record file will be relative to
5751 address 0x00000000. To load it to a given address, you need to
5752 specify the target address as 'offset' parameter with the 'loads'
5755 Example: install the image to address 0x40100000 (which on the
5756 TQM8xxL is in the first Flash bank):
5758 => erase 40100000 401FFFFF
5764 ## Ready for S-Record download ...
5765 ~>examples/image.srec
5766 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
5768 15989 15990 15991 15992
5769 [file transfer complete]
5771 ## Start Addr = 0x00000000
5774 You can check the success of the download using the 'iminfo' command;
5775 this includes a checksum verification so you can be sure no data
5776 corruption happened:
5780 ## Checking Image at 40100000 ...
5781 Image Name: 2.2.13 for initrd on TQM850L
5782 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5783 Data Size: 335725 Bytes = 327 kB = 0 MB
5784 Load Address: 00000000
5785 Entry Point: 0000000c
5786 Verifying Checksum ... OK
5792 The "bootm" command is used to boot an application that is stored in
5793 memory (RAM or Flash). In case of a Linux kernel image, the contents
5794 of the "bootargs" environment variable is passed to the kernel as
5795 parameters. You can check and modify this variable using the
5796 "printenv" and "setenv" commands:
5799 => printenv bootargs
5800 bootargs=root=/dev/ram
5802 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5804 => printenv bootargs
5805 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5808 ## Booting Linux kernel at 40020000 ...
5809 Image Name: 2.2.13 for NFS on TQM850L
5810 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5811 Data Size: 381681 Bytes = 372 kB = 0 MB
5812 Load Address: 00000000
5813 Entry Point: 0000000c
5814 Verifying Checksum ... OK
5815 Uncompressing Kernel Image ... OK
5816 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
5817 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5818 time_init: decrementer frequency = 187500000/60
5819 Calibrating delay loop... 49.77 BogoMIPS
5820 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
5823 If you want to boot a Linux kernel with initial RAM disk, you pass
5824 the memory addresses of both the kernel and the initrd image (PPBCOOT
5825 format!) to the "bootm" command:
5827 => imi 40100000 40200000
5829 ## Checking Image at 40100000 ...
5830 Image Name: 2.2.13 for initrd on TQM850L
5831 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5832 Data Size: 335725 Bytes = 327 kB = 0 MB
5833 Load Address: 00000000
5834 Entry Point: 0000000c
5835 Verifying Checksum ... OK
5837 ## Checking Image at 40200000 ...
5838 Image Name: Simple Ramdisk Image
5839 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5840 Data Size: 566530 Bytes = 553 kB = 0 MB
5841 Load Address: 00000000
5842 Entry Point: 00000000
5843 Verifying Checksum ... OK
5845 => bootm 40100000 40200000
5846 ## Booting Linux kernel at 40100000 ...
5847 Image Name: 2.2.13 for initrd on TQM850L
5848 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5849 Data Size: 335725 Bytes = 327 kB = 0 MB
5850 Load Address: 00000000
5851 Entry Point: 0000000c
5852 Verifying Checksum ... OK
5853 Uncompressing Kernel Image ... OK
5854 ## Loading RAMDisk Image at 40200000 ...
5855 Image Name: Simple Ramdisk Image
5856 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5857 Data Size: 566530 Bytes = 553 kB = 0 MB
5858 Load Address: 00000000
5859 Entry Point: 00000000
5860 Verifying Checksum ... OK
5861 Loading Ramdisk ... OK
5862 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
5863 Boot arguments: root=/dev/ram
5864 time_init: decrementer frequency = 187500000/60
5865 Calibrating delay loop... 49.77 BogoMIPS
5867 RAMDISK: Compressed image found at block 0
5868 VFS: Mounted root (ext2 filesystem).
5872 Boot Linux and pass a flat device tree:
5875 First, U-Boot must be compiled with the appropriate defines. See the section
5876 titled "Linux Kernel Interface" above for a more in depth explanation. The
5877 following is an example of how to start a kernel and pass an updated
5883 oft=oftrees/mpc8540ads.dtb
5884 => tftp $oftaddr $oft
5885 Speed: 1000, full duplex
5887 TFTP from server 192.168.1.1; our IP address is 192.168.1.101
5888 Filename 'oftrees/mpc8540ads.dtb'.
5889 Load address: 0x300000
5892 Bytes transferred = 4106 (100a hex)
5893 => tftp $loadaddr $bootfile
5894 Speed: 1000, full duplex
5896 TFTP from server 192.168.1.1; our IP address is 192.168.1.2
5898 Load address: 0x200000
5899 Loading:############
5901 Bytes transferred = 1029407 (fb51f hex)
5906 => bootm $loadaddr - $oftaddr
5907 ## Booting image at 00200000 ...
5908 Image Name: Linux-2.6.17-dirty
5909 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5910 Data Size: 1029343 Bytes = 1005.2 kB
5911 Load Address: 00000000
5912 Entry Point: 00000000
5913 Verifying Checksum ... OK
5914 Uncompressing Kernel Image ... OK
5915 Booting using flat device tree at 0x300000
5916 Using MPC85xx ADS machine description
5917 Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb
5921 More About U-Boot Image Types:
5922 ------------------------------
5924 U-Boot supports the following image types:
5926 "Standalone Programs" are directly runnable in the environment
5927 provided by U-Boot; it is expected that (if they behave
5928 well) you can continue to work in U-Boot after return from
5929 the Standalone Program.
5930 "OS Kernel Images" are usually images of some Embedded OS which
5931 will take over control completely. Usually these programs
5932 will install their own set of exception handlers, device
5933 drivers, set up the MMU, etc. - this means, that you cannot
5934 expect to re-enter U-Boot except by resetting the CPU.
5935 "RAMDisk Images" are more or less just data blocks, and their
5936 parameters (address, size) are passed to an OS kernel that is
5938 "Multi-File Images" contain several images, typically an OS
5939 (Linux) kernel image and one or more data images like
5940 RAMDisks. This construct is useful for instance when you want
5941 to boot over the network using BOOTP etc., where the boot
5942 server provides just a single image file, but you want to get
5943 for instance an OS kernel and a RAMDisk image.
5945 "Multi-File Images" start with a list of image sizes, each
5946 image size (in bytes) specified by an "uint32_t" in network
5947 byte order. This list is terminated by an "(uint32_t)0".
5948 Immediately after the terminating 0 follow the images, one by
5949 one, all aligned on "uint32_t" boundaries (size rounded up to
5950 a multiple of 4 bytes).
5952 "Firmware Images" are binary images containing firmware (like
5953 U-Boot or FPGA images) which usually will be programmed to
5956 "Script files" are command sequences that will be executed by
5957 U-Boot's command interpreter; this feature is especially
5958 useful when you configure U-Boot to use a real shell (hush)
5959 as command interpreter.
5961 Booting the Linux zImage:
5962 -------------------------
5964 On some platforms, it's possible to boot Linux zImage. This is done
5965 using the "bootz" command. The syntax of "bootz" command is the same
5966 as the syntax of "bootm" command.
5968 Note, defining the CONFIG_SUPPORT_RAW_INITRD allows user to supply
5969 kernel with raw initrd images. The syntax is slightly different, the
5970 address of the initrd must be augmented by it's size, in the following
5971 format: "<initrd addres>:<initrd size>".
5977 One of the features of U-Boot is that you can dynamically load and
5978 run "standalone" applications, which can use some resources of
5979 U-Boot like console I/O functions or interrupt services.
5981 Two simple examples are included with the sources:
5986 'examples/hello_world.c' contains a small "Hello World" Demo
5987 application; it is automatically compiled when you build U-Boot.
5988 It's configured to run at address 0x00040004, so you can play with it
5992 ## Ready for S-Record download ...
5993 ~>examples/hello_world.srec
5994 1 2 3 4 5 6 7 8 9 10 11 ...
5995 [file transfer complete]
5997 ## Start Addr = 0x00040004
5999 => go 40004 Hello World! This is a test.
6000 ## Starting application at 0x00040004 ...
6011 Hit any key to exit ...
6013 ## Application terminated, rc = 0x0
6015 Another example, which demonstrates how to register a CPM interrupt
6016 handler with the U-Boot code, can be found in 'examples/timer.c'.
6017 Here, a CPM timer is set up to generate an interrupt every second.
6018 The interrupt service routine is trivial, just printing a '.'
6019 character, but this is just a demo program. The application can be
6020 controlled by the following keys:
6022 ? - print current values og the CPM Timer registers
6023 b - enable interrupts and start timer
6024 e - stop timer and disable interrupts
6025 q - quit application
6028 ## Ready for S-Record download ...
6029 ~>examples/timer.srec
6030 1 2 3 4 5 6 7 8 9 10 11 ...
6031 [file transfer complete]
6033 ## Start Addr = 0x00040004
6036 ## Starting application at 0x00040004 ...
6039 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
6042 [q, b, e, ?] Set interval 1000000 us
6045 [q, b, e, ?] ........
6046 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
6049 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
6052 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
6055 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
6057 [q, b, e, ?] ...Stopping timer
6059 [q, b, e, ?] ## Application terminated, rc = 0x0
6065 Over time, many people have reported problems when trying to use the
6066 "minicom" terminal emulation program for serial download. I (wd)
6067 consider minicom to be broken, and recommend not to use it. Under
6068 Unix, I recommend to use C-Kermit for general purpose use (and
6069 especially for kermit binary protocol download ("loadb" command), and
6070 use "cu" for S-Record download ("loads" command). See
6071 http://www.denx.de/wiki/view/DULG/SystemSetup#Section_4.3.
6072 for help with kermit.
6075 Nevertheless, if you absolutely want to use it try adding this
6076 configuration to your "File transfer protocols" section:
6078 Name Program Name U/D FullScr IO-Red. Multi
6079 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
6080 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
6086 Starting at version 0.9.2, U-Boot supports NetBSD both as host
6087 (build U-Boot) and target system (boots NetBSD/mpc8xx).
6089 Building requires a cross environment; it is known to work on
6090 NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
6091 need gmake since the Makefiles are not compatible with BSD make).
6092 Note that the cross-powerpc package does not install include files;
6093 attempting to build U-Boot will fail because <machine/ansi.h> is
6094 missing. This file has to be installed and patched manually:
6096 # cd /usr/pkg/cross/powerpc-netbsd/include
6098 # ln -s powerpc machine
6099 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
6100 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
6102 Native builds *don't* work due to incompatibilities between native
6103 and U-Boot include files.
6105 Booting assumes that (the first part of) the image booted is a
6106 stage-2 loader which in turn loads and then invokes the kernel
6107 proper. Loader sources will eventually appear in the NetBSD source
6108 tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
6109 meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz
6112 Implementation Internals:
6113 =========================
6115 The following is not intended to be a complete description of every
6116 implementation detail. However, it should help to understand the
6117 inner workings of U-Boot and make it easier to port it to custom
6121 Initial Stack, Global Data:
6122 ---------------------------
6124 The implementation of U-Boot is complicated by the fact that U-Boot
6125 starts running out of ROM (flash memory), usually without access to
6126 system RAM (because the memory controller is not initialized yet).
6127 This means that we don't have writable Data or BSS segments, and BSS
6128 is not initialized as zero. To be able to get a C environment working
6129 at all, we have to allocate at least a minimal stack. Implementation
6130 options for this are defined and restricted by the CPU used: Some CPU
6131 models provide on-chip memory (like the IMMR area on MPC8xx and
6132 MPC826x processors), on others (parts of) the data cache can be
6133 locked as (mis-) used as memory, etc.
6135 Chris Hallinan posted a good summary of these issues to the
6136 U-Boot mailing list:
6138 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
6139 From: "Chris Hallinan" <clh@net1plus.com>
6140 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
6143 Correct me if I'm wrong, folks, but the way I understand it
6144 is this: Using DCACHE as initial RAM for Stack, etc, does not
6145 require any physical RAM backing up the cache. The cleverness
6146 is that the cache is being used as a temporary supply of
6147 necessary storage before the SDRAM controller is setup. It's
6148 beyond the scope of this list to explain the details, but you
6149 can see how this works by studying the cache architecture and
6150 operation in the architecture and processor-specific manuals.
6152 OCM is On Chip Memory, which I believe the 405GP has 4K. It
6153 is another option for the system designer to use as an
6154 initial stack/RAM area prior to SDRAM being available. Either
6155 option should work for you. Using CS 4 should be fine if your
6156 board designers haven't used it for something that would
6157 cause you grief during the initial boot! It is frequently not
6160 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere
6161 with your processor/board/system design. The default value
6162 you will find in any recent u-boot distribution in
6163 walnut.h should work for you. I'd set it to a value larger
6164 than your SDRAM module. If you have a 64MB SDRAM module, set
6165 it above 400_0000. Just make sure your board has no resources
6166 that are supposed to respond to that address! That code in
6167 start.S has been around a while and should work as is when
6168 you get the config right.
6173 It is essential to remember this, since it has some impact on the C
6174 code for the initialization procedures:
6176 * Initialized global data (data segment) is read-only. Do not attempt
6179 * Do not use any uninitialized global data (or implicitely initialized
6180 as zero data - BSS segment) at all - this is undefined, initiali-
6181 zation is performed later (when relocating to RAM).
6183 * Stack space is very limited. Avoid big data buffers or things like
6186 Having only the stack as writable memory limits means we cannot use
6187 normal global data to share information beween the code. But it
6188 turned out that the implementation of U-Boot can be greatly
6189 simplified by making a global data structure (gd_t) available to all
6190 functions. We could pass a pointer to this data as argument to _all_
6191 functions, but this would bloat the code. Instead we use a feature of
6192 the GCC compiler (Global Register Variables) to share the data: we
6193 place a pointer (gd) to the global data into a register which we
6194 reserve for this purpose.
6196 When choosing a register for such a purpose we are restricted by the
6197 relevant (E)ABI specifications for the current architecture, and by
6198 GCC's implementation.
6200 For PowerPC, the following registers have specific use:
6202 R2: reserved for system use
6203 R3-R4: parameter passing and return values
6204 R5-R10: parameter passing
6205 R13: small data area pointer
6209 (U-Boot also uses R12 as internal GOT pointer. r12
6210 is a volatile register so r12 needs to be reset when
6211 going back and forth between asm and C)
6213 ==> U-Boot will use R2 to hold a pointer to the global data
6215 Note: on PPC, we could use a static initializer (since the
6216 address of the global data structure is known at compile time),
6217 but it turned out that reserving a register results in somewhat
6218 smaller code - although the code savings are not that big (on
6219 average for all boards 752 bytes for the whole U-Boot image,
6220 624 text + 127 data).
6222 On Blackfin, the normal C ABI (except for P3) is followed as documented here:
6223 http://docs.blackfin.uclinux.org/doku.php?id=application_binary_interface
6225 ==> U-Boot will use P3 to hold a pointer to the global data
6227 On ARM, the following registers are used:
6229 R0: function argument word/integer result
6230 R1-R3: function argument word
6231 R9: platform specific
6232 R10: stack limit (used only if stack checking is enabled)
6233 R11: argument (frame) pointer
6234 R12: temporary workspace
6237 R15: program counter
6239 ==> U-Boot will use R9 to hold a pointer to the global data
6241 Note: on ARM, only R_ARM_RELATIVE relocations are supported.
6243 On Nios II, the ABI is documented here:
6244 http://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf
6246 ==> U-Boot will use gp to hold a pointer to the global data
6248 Note: on Nios II, we give "-G0" option to gcc and don't use gp
6249 to access small data sections, so gp is free.
6251 On NDS32, the following registers are used:
6253 R0-R1: argument/return
6255 R15: temporary register for assembler
6256 R16: trampoline register
6257 R28: frame pointer (FP)
6258 R29: global pointer (GP)
6259 R30: link register (LP)
6260 R31: stack pointer (SP)
6261 PC: program counter (PC)
6263 ==> U-Boot will use R10 to hold a pointer to the global data
6265 NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope,
6266 or current versions of GCC may "optimize" the code too much.
6271 U-Boot runs in system state and uses physical addresses, i.e. the
6272 MMU is not used either for address mapping nor for memory protection.
6274 The available memory is mapped to fixed addresses using the memory
6275 controller. In this process, a contiguous block is formed for each
6276 memory type (Flash, SDRAM, SRAM), even when it consists of several
6277 physical memory banks.
6279 U-Boot is installed in the first 128 kB of the first Flash bank (on
6280 TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
6281 booting and sizing and initializing DRAM, the code relocates itself
6282 to the upper end of DRAM. Immediately below the U-Boot code some
6283 memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN
6284 configuration setting]. Below that, a structure with global Board
6285 Info data is placed, followed by the stack (growing downward).
6287 Additionally, some exception handler code is copied to the low 8 kB
6288 of DRAM (0x00000000 ... 0x00001FFF).
6290 So a typical memory configuration with 16 MB of DRAM could look like
6293 0x0000 0000 Exception Vector code
6296 0x0000 2000 Free for Application Use
6302 0x00FB FF20 Monitor Stack (Growing downward)
6303 0x00FB FFAC Board Info Data and permanent copy of global data
6304 0x00FC 0000 Malloc Arena
6307 0x00FE 0000 RAM Copy of Monitor Code
6308 ... eventually: LCD or video framebuffer
6309 ... eventually: pRAM (Protected RAM - unchanged by reset)
6310 0x00FF FFFF [End of RAM]
6313 System Initialization:
6314 ----------------------
6316 In the reset configuration, U-Boot starts at the reset entry point
6317 (on most PowerPC systems at address 0x00000100). Because of the reset
6318 configuration for CS0# this is a mirror of the onboard Flash memory.
6319 To be able to re-map memory U-Boot then jumps to its link address.
6320 To be able to implement the initialization code in C, a (small!)
6321 initial stack is set up in the internal Dual Ported RAM (in case CPUs
6322 which provide such a feature like MPC8xx or MPC8260), or in a locked
6323 part of the data cache. After that, U-Boot initializes the CPU core,
6324 the caches and the SIU.
6326 Next, all (potentially) available memory banks are mapped using a
6327 preliminary mapping. For example, we put them on 512 MB boundaries
6328 (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
6329 on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
6330 programmed for SDRAM access. Using the temporary configuration, a
6331 simple memory test is run that determines the size of the SDRAM
6334 When there is more than one SDRAM bank, and the banks are of
6335 different size, the largest is mapped first. For equal size, the first
6336 bank (CS2#) is mapped first. The first mapping is always for address
6337 0x00000000, with any additional banks following immediately to create
6338 contiguous memory starting from 0.
6340 Then, the monitor installs itself at the upper end of the SDRAM area
6341 and allocates memory for use by malloc() and for the global Board
6342 Info data; also, the exception vector code is copied to the low RAM
6343 pages, and the final stack is set up.
6345 Only after this relocation will you have a "normal" C environment;
6346 until that you are restricted in several ways, mostly because you are
6347 running from ROM, and because the code will have to be relocated to a
6351 U-Boot Porting Guide:
6352 ----------------------
6354 [Based on messages by Jerry Van Baren in the U-Boot-Users mailing
6358 int main(int argc, char *argv[])
6360 sighandler_t no_more_time;
6362 signal(SIGALRM, no_more_time);
6363 alarm(PROJECT_DEADLINE - toSec (3 * WEEK));
6365 if (available_money > available_manpower) {
6366 Pay consultant to port U-Boot;
6370 Download latest U-Boot source;
6372 Subscribe to u-boot mailing list;
6375 email("Hi, I am new to U-Boot, how do I get started?");
6378 Read the README file in the top level directory;
6379 Read http://www.denx.de/twiki/bin/view/DULG/Manual;
6380 Read applicable doc/*.README;
6381 Read the source, Luke;
6382 /* find . -name "*.[chS]" | xargs grep -i <keyword> */
6385 if (available_money > toLocalCurrency ($2500))
6388 Add a lot of aggravation and time;
6390 if (a similar board exists) { /* hopefully... */
6391 cp -a board/<similar> board/<myboard>
6392 cp include/configs/<similar>.h include/configs/<myboard>.h
6394 Create your own board support subdirectory;
6395 Create your own board include/configs/<myboard>.h file;
6397 Edit new board/<myboard> files
6398 Edit new include/configs/<myboard>.h
6403 Add / modify source code;
6407 email("Hi, I am having problems...");
6409 Send patch file to the U-Boot email list;
6410 if (reasonable critiques)
6411 Incorporate improvements from email list code review;
6413 Defend code as written;
6419 void no_more_time (int sig)
6428 All contributions to U-Boot should conform to the Linux kernel
6429 coding style; see the file "Documentation/CodingStyle" and the script
6430 "scripts/Lindent" in your Linux kernel source directory.
6432 Source files originating from a different project (for example the
6433 MTD subsystem) are generally exempt from these guidelines and are not
6434 reformated to ease subsequent migration to newer versions of those
6437 Please note that U-Boot is implemented in C (and to some small parts in
6438 Assembler); no C++ is used, so please do not use C++ style comments (//)
6441 Please also stick to the following formatting rules:
6442 - remove any trailing white space
6443 - use TAB characters for indentation and vertical alignment, not spaces
6444 - make sure NOT to use DOS '\r\n' line feeds
6445 - do not add more than 2 consecutive empty lines to source files
6446 - do not add trailing empty lines to source files
6448 Submissions which do not conform to the standards may be returned
6449 with a request to reformat the changes.
6455 Since the number of patches for U-Boot is growing, we need to
6456 establish some rules. Submissions which do not conform to these rules
6457 may be rejected, even when they contain important and valuable stuff.
6459 Please see http://www.denx.de/wiki/U-Boot/Patches for details.
6461 Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>;
6462 see http://lists.denx.de/mailman/listinfo/u-boot
6464 When you send a patch, please include the following information with
6467 * For bug fixes: a description of the bug and how your patch fixes
6468 this bug. Please try to include a way of demonstrating that the
6469 patch actually fixes something.
6471 * For new features: a description of the feature and your
6474 * A CHANGELOG entry as plaintext (separate from the patch)
6476 * For major contributions, your entry to the CREDITS file
6478 * When you add support for a new board, don't forget to add a
6479 maintainer e-mail address to the boards.cfg file, too.
6481 * If your patch adds new configuration options, don't forget to
6482 document these in the README file.
6484 * The patch itself. If you are using git (which is *strongly*
6485 recommended) you can easily generate the patch using the
6486 "git format-patch". If you then use "git send-email" to send it to
6487 the U-Boot mailing list, you will avoid most of the common problems
6488 with some other mail clients.
6490 If you cannot use git, use "diff -purN OLD NEW". If your version of
6491 diff does not support these options, then get the latest version of
6494 The current directory when running this command shall be the parent
6495 directory of the U-Boot source tree (i. e. please make sure that
6496 your patch includes sufficient directory information for the
6499 We prefer patches as plain text. MIME attachments are discouraged,
6500 and compressed attachments must not be used.
6502 * If one logical set of modifications affects or creates several
6503 files, all these changes shall be submitted in a SINGLE patch file.
6505 * Changesets that contain different, unrelated modifications shall be
6506 submitted as SEPARATE patches, one patch per changeset.
6511 * Before sending the patch, run the MAKEALL script on your patched
6512 source tree and make sure that no errors or warnings are reported
6513 for any of the boards.
6515 * Keep your modifications to the necessary minimum: A patch
6516 containing several unrelated changes or arbitrary reformats will be
6517 returned with a request to re-formatting / split it.
6519 * If you modify existing code, make sure that your new code does not
6520 add to the memory footprint of the code ;-) Small is beautiful!
6521 When adding new features, these should compile conditionally only
6522 (using #ifdef), and the resulting code with the new feature
6523 disabled must not need more memory than the old code without your
6526 * Remember that there is a size limit of 100 kB per message on the
6527 u-boot mailing list. Bigger patches will be moderated. If they are
6528 reasonable and not too big, they will be acknowledged. But patches
6529 bigger than the size limit should be avoided.
projects / karo-tx-uboot.git / blob