2 # (C) Copyright 2000 - 2012
3 # Wolfgang Denk, DENX Software Engineering, wd@denx.de.
5 # See file CREDITS for list of people who contributed to this
8 # This program is free software; you can redistribute it and/or
9 # modify it under the terms of the GNU General Public License as
10 # published by the Free Software Foundation; either version 2 of
11 # the License, or (at your option) any later version.
13 # This program is distributed in the hope that it will be useful,
14 # but WITHOUT ANY WARRANTY; without even the implied warranty of
15 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 # GNU General Public License for more details.
18 # You should have received a copy of the GNU General Public License
19 # along with this program; if not, write to the Free Software
20 # Foundation, Inc., 59 Temple Place, Suite 330, Boston,
27 This directory contains the source code for U-Boot, a boot loader for
28 Embedded boards based on PowerPC, ARM, MIPS and several other
29 processors, which can be installed in a boot ROM and used to
30 initialize and test the hardware or to download and run application
33 The development of U-Boot is closely related to Linux: some parts of
34 the source code originate in the Linux source tree, we have some
35 header files in common, and special provision has been made to
36 support booting of Linux images.
38 Some attention has been paid to make this software easily
39 configurable and extendable. For instance, all monitor commands are
40 implemented with the same call interface, so that it's very easy to
41 add new commands. Also, instead of permanently adding rarely used
42 code (for instance hardware test utilities) to the monitor, you can
43 load and run it dynamically.
49 In general, all boards for which a configuration option exists in the
50 Makefile have been tested to some extent and can be considered
51 "working". In fact, many of them are used in production systems.
53 In case of problems see the CHANGELOG and CREDITS files to find out
54 who contributed the specific port. The MAINTAINERS file lists board
57 Note: There is no CHANGELOG file in the actual U-Boot source tree;
58 it can be created dynamically from the Git log using:
66 In case you have questions about, problems with or contributions for
67 U-Boot you should send a message to the U-Boot mailing list at
68 <u-boot@lists.denx.de>. There is also an archive of previous traffic
69 on the mailing list - please search the archive before asking FAQ's.
70 Please see http://lists.denx.de/pipermail/u-boot and
71 http://dir.gmane.org/gmane.comp.boot-loaders.u-boot
74 Where to get source code:
75 =========================
77 The U-Boot source code is maintained in the git repository at
78 git://www.denx.de/git/u-boot.git ; you can browse it online at
79 http://www.denx.de/cgi-bin/gitweb.cgi?p=u-boot.git;a=summary
81 The "snapshot" links on this page allow you to download tarballs of
82 any version you might be interested in. Official releases are also
83 available for FTP download from the ftp://ftp.denx.de/pub/u-boot/
86 Pre-built (and tested) images are available from
87 ftp://ftp.denx.de/pub/u-boot/images/
93 - start from 8xxrom sources
94 - create PPCBoot project (http://sourceforge.net/projects/ppcboot)
96 - make it easier to add custom boards
97 - make it possible to add other [PowerPC] CPUs
98 - extend functions, especially:
99 * Provide extended interface to Linux boot loader
102 * PCMCIA / CompactFlash / ATA disk / SCSI ... boot
103 - create ARMBoot project (http://sourceforge.net/projects/armboot)
104 - add other CPU families (starting with ARM)
105 - create U-Boot project (http://sourceforge.net/projects/u-boot)
106 - current project page: see http://www.denx.de/wiki/U-Boot
112 The "official" name of this project is "Das U-Boot". The spelling
113 "U-Boot" shall be used in all written text (documentation, comments
114 in source files etc.). Example:
116 This is the README file for the U-Boot project.
118 File names etc. shall be based on the string "u-boot". Examples:
120 include/asm-ppc/u-boot.h
122 #include <asm/u-boot.h>
124 Variable names, preprocessor constants etc. shall be either based on
125 the string "u_boot" or on "U_BOOT". Example:
127 U_BOOT_VERSION u_boot_logo
128 IH_OS_U_BOOT u_boot_hush_start
134 Starting with the release in October 2008, the names of the releases
135 were changed from numerical release numbers without deeper meaning
136 into a time stamp based numbering. Regular releases are identified by
137 names consisting of the calendar year and month of the release date.
138 Additional fields (if present) indicate release candidates or bug fix
139 releases in "stable" maintenance trees.
142 U-Boot v2009.11 - Release November 2009
143 U-Boot v2009.11.1 - Release 1 in version November 2009 stable tree
144 U-Boot v2010.09-rc1 - Release candiate 1 for September 2010 release
150 /arch Architecture specific files
151 /arm Files generic to ARM architecture
152 /cpu CPU specific files
153 /arm720t Files specific to ARM 720 CPUs
154 /arm920t Files specific to ARM 920 CPUs
155 /at91 Files specific to Atmel AT91RM9200 CPU
156 /imx Files specific to Freescale MC9328 i.MX CPUs
157 /s3c24x0 Files specific to Samsung S3C24X0 CPUs
158 /arm925t Files specific to ARM 925 CPUs
159 /arm926ejs Files specific to ARM 926 CPUs
160 /arm1136 Files specific to ARM 1136 CPUs
161 /ixp Files specific to Intel XScale IXP CPUs
162 /pxa Files specific to Intel XScale PXA CPUs
163 /s3c44b0 Files specific to Samsung S3C44B0 CPUs
164 /sa1100 Files specific to Intel StrongARM SA1100 CPUs
165 /lib Architecture specific library files
166 /avr32 Files generic to AVR32 architecture
167 /cpu CPU specific files
168 /lib Architecture specific library files
169 /blackfin Files generic to Analog Devices Blackfin architecture
170 /cpu CPU specific files
171 /lib Architecture specific library files
172 /x86 Files generic to x86 architecture
173 /cpu CPU specific files
174 /lib Architecture specific library files
175 /m68k Files generic to m68k architecture
176 /cpu CPU specific files
177 /mcf52x2 Files specific to Freescale ColdFire MCF52x2 CPUs
178 /mcf5227x Files specific to Freescale ColdFire MCF5227x CPUs
179 /mcf532x Files specific to Freescale ColdFire MCF5329 CPUs
180 /mcf5445x Files specific to Freescale ColdFire MCF5445x CPUs
181 /mcf547x_8x Files specific to Freescale ColdFire MCF547x_8x CPUs
182 /lib Architecture specific library files
183 /microblaze Files generic to microblaze architecture
184 /cpu CPU specific files
185 /lib Architecture specific library files
186 /mips Files generic to MIPS architecture
187 /cpu CPU specific files
188 /mips32 Files specific to MIPS32 CPUs
189 /xburst Files specific to Ingenic XBurst CPUs
190 /lib Architecture specific library files
191 /nds32 Files generic to NDS32 architecture
192 /cpu CPU specific files
193 /n1213 Files specific to Andes Technology N1213 CPUs
194 /lib Architecture specific library files
195 /nios2 Files generic to Altera NIOS2 architecture
196 /cpu CPU specific files
197 /lib Architecture specific library files
198 /powerpc Files generic to PowerPC architecture
199 /cpu CPU specific files
200 /74xx_7xx Files specific to Freescale MPC74xx and 7xx CPUs
201 /mpc5xx Files specific to Freescale MPC5xx CPUs
202 /mpc5xxx Files specific to Freescale MPC5xxx CPUs
203 /mpc8xx Files specific to Freescale MPC8xx CPUs
204 /mpc8220 Files specific to Freescale MPC8220 CPUs
205 /mpc824x Files specific to Freescale MPC824x CPUs
206 /mpc8260 Files specific to Freescale MPC8260 CPUs
207 /mpc85xx Files specific to Freescale MPC85xx CPUs
208 /ppc4xx Files specific to AMCC PowerPC 4xx CPUs
209 /lib Architecture specific library files
210 /sh Files generic to SH architecture
211 /cpu CPU specific files
212 /sh2 Files specific to sh2 CPUs
213 /sh3 Files specific to sh3 CPUs
214 /sh4 Files specific to sh4 CPUs
215 /lib Architecture specific library files
216 /sparc Files generic to SPARC architecture
217 /cpu CPU specific files
218 /leon2 Files specific to Gaisler LEON2 SPARC CPU
219 /leon3 Files specific to Gaisler LEON3 SPARC CPU
220 /lib Architecture specific library files
221 /api Machine/arch independent API for external apps
222 /board Board dependent files
223 /common Misc architecture independent functions
224 /disk Code for disk drive partition handling
225 /doc Documentation (don't expect too much)
226 /drivers Commonly used device drivers
227 /examples Example code for standalone applications, etc.
228 /fs Filesystem code (cramfs, ext2, jffs2, etc.)
229 /include Header Files
230 /lib Files generic to all architectures
231 /libfdt Library files to support flattened device trees
232 /lzma Library files to support LZMA decompression
233 /lzo Library files to support LZO decompression
235 /post Power On Self Test
236 /rtc Real Time Clock drivers
237 /tools Tools to build S-Record or U-Boot images, etc.
239 Software Configuration:
240 =======================
242 Configuration is usually done using C preprocessor defines; the
243 rationale behind that is to avoid dead code whenever possible.
245 There are two classes of configuration variables:
247 * Configuration _OPTIONS_:
248 These are selectable by the user and have names beginning with
251 * Configuration _SETTINGS_:
252 These depend on the hardware etc. and should not be meddled with if
253 you don't know what you're doing; they have names beginning with
256 Later we will add a configuration tool - probably similar to or even
257 identical to what's used for the Linux kernel. Right now, we have to
258 do the configuration by hand, which means creating some symbolic
259 links and editing some configuration files. We use the TQM8xxL boards
263 Selection of Processor Architecture and Board Type:
264 ---------------------------------------------------
266 For all supported boards there are ready-to-use default
267 configurations available; just type "make <board_name>_config".
269 Example: For a TQM823L module type:
274 For the Cogent platform, you need to specify the CPU type as well;
275 e.g. "make cogent_mpc8xx_config". And also configure the cogent
276 directory according to the instructions in cogent/README.
279 Configuration Options:
280 ----------------------
282 Configuration depends on the combination of board and CPU type; all
283 such information is kept in a configuration file
284 "include/configs/<board_name>.h".
286 Example: For a TQM823L module, all configuration settings are in
287 "include/configs/TQM823L.h".
290 Many of the options are named exactly as the corresponding Linux
291 kernel configuration options. The intention is to make it easier to
292 build a config tool - later.
295 The following options need to be configured:
297 - CPU Type: Define exactly one, e.g. CONFIG_MPC85XX.
299 - Board Type: Define exactly one, e.g. CONFIG_MPC8540ADS.
301 - CPU Daughterboard Type: (if CONFIG_ATSTK1000 is defined)
302 Define exactly one, e.g. CONFIG_ATSTK1002
304 - CPU Module Type: (if CONFIG_COGENT is defined)
305 Define exactly one of
307 --- FIXME --- not tested yet:
308 CONFIG_CMA286_60, CONFIG_CMA286_21, CONFIG_CMA286_60P,
309 CONFIG_CMA287_23, CONFIG_CMA287_50
311 - Motherboard Type: (if CONFIG_COGENT is defined)
312 Define exactly one of
313 CONFIG_CMA101, CONFIG_CMA102
315 - Motherboard I/O Modules: (if CONFIG_COGENT is defined)
316 Define one or more of
319 - Motherboard Options: (if CONFIG_CMA101 or CONFIG_CMA102 are defined)
320 Define one or more of
321 CONFIG_LCD_HEARTBEAT - update a character position on
322 the LCD display every second with
325 - Board flavour: (if CONFIG_MPC8260ADS is defined)
328 CONFIG_SYS_8260ADS - original MPC8260ADS
329 CONFIG_SYS_8266ADS - MPC8266ADS
330 CONFIG_SYS_PQ2FADS - PQ2FADS-ZU or PQ2FADS-VR
331 CONFIG_SYS_8272ADS - MPC8272ADS
333 - Marvell Family Member
334 CONFIG_SYS_MVFS - define it if you want to enable
335 multiple fs option at one time
336 for marvell soc family
338 - MPC824X Family Member (if CONFIG_MPC824X is defined)
339 Define exactly one of
340 CONFIG_MPC8240, CONFIG_MPC8245
342 - 8xx CPU Options: (if using an MPC8xx CPU)
343 CONFIG_8xx_GCLK_FREQ - deprecated: CPU clock if
344 get_gclk_freq() cannot work
345 e.g. if there is no 32KHz
346 reference PIT/RTC clock
347 CONFIG_8xx_OSCLK - PLL input clock (either EXTCLK
350 - 859/866/885 CPU options: (if using a MPC859 or MPC866 or MPC885 CPU):
351 CONFIG_SYS_8xx_CPUCLK_MIN
352 CONFIG_SYS_8xx_CPUCLK_MAX
353 CONFIG_8xx_CPUCLK_DEFAULT
354 See doc/README.MPC866
356 CONFIG_SYS_MEASURE_CPUCLK
358 Define this to measure the actual CPU clock instead
359 of relying on the correctness of the configured
360 values. Mostly useful for board bringup to make sure
361 the PLL is locked at the intended frequency. Note
362 that this requires a (stable) reference clock (32 kHz
363 RTC clock or CONFIG_SYS_8XX_XIN)
365 CONFIG_SYS_DELAYED_ICACHE
367 Define this option if you want to enable the
368 ICache only when Code runs from RAM.
373 Specifies that the core is a 64-bit PowerPC implementation (implements
374 the "64" category of the Power ISA). This is necessary for ePAPR
375 compliance, among other possible reasons.
377 CONFIG_SYS_FSL_TBCLK_DIV
379 Defines the core time base clock divider ratio compared to the
380 system clock. On most PQ3 devices this is 8, on newer QorIQ
381 devices it can be 16 or 32. The ratio varies from SoC to Soc.
383 CONFIG_SYS_FSL_PCIE_COMPAT
385 Defines the string to utilize when trying to match PCIe device
386 tree nodes for the given platform.
388 CONFIG_SYS_PPC_E500_DEBUG_TLB
390 Enables a temporary TLB entry to be used during boot to work
391 around limitations in e500v1 and e500v2 external debugger
392 support. This reduces the portions of the boot code where
393 breakpoints and single stepping do not work. The value of this
394 symbol should be set to the TLB1 entry to be used for this
397 CONFIG_SYS_FSL_ERRATUM_A004510
399 Enables a workaround for erratum A004510. If set,
400 then CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV and
401 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY must be set.
403 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV
404 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV2 (optional)
406 Defines one or two SoC revisions (low 8 bits of SVR)
407 for which the A004510 workaround should be applied.
409 The rest of SVR is either not relevant to the decision
410 of whether the erratum is present (e.g. p2040 versus
411 p2041) or is implied by the build target, which controls
412 whether CONFIG_SYS_FSL_ERRATUM_A004510 is set.
414 See Freescale App Note 4493 for more information about
417 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY
419 This is the value to write into CCSR offset 0x18600
420 according to the A004510 workaround.
422 - Generic CPU options:
423 CONFIG_SYS_BIG_ENDIAN, CONFIG_SYS_LITTLE_ENDIAN
425 Defines the endianess of the CPU. Implementation of those
426 values is arch specific.
428 - Intel Monahans options:
429 CONFIG_SYS_MONAHANS_RUN_MODE_OSC_RATIO
431 Defines the Monahans run mode to oscillator
432 ratio. Valid values are 8, 16, 24, 31. The core
433 frequency is this value multiplied by 13 MHz.
435 CONFIG_SYS_MONAHANS_TURBO_RUN_MODE_RATIO
437 Defines the Monahans turbo mode to oscillator
438 ratio. Valid values are 1 (default if undefined) and
439 2. The core frequency as calculated above is multiplied
443 CONFIG_SYS_INIT_SP_OFFSET
445 Offset relative to CONFIG_SYS_SDRAM_BASE for initial stack
446 pointer. This is needed for the temporary stack before
449 CONFIG_SYS_MIPS_CACHE_MODE
451 Cache operation mode for the MIPS CPU.
452 See also arch/mips/include/asm/mipsregs.h.
454 CONF_CM_CACHABLE_NO_WA
457 CONF_CM_CACHABLE_NONCOHERENT
461 CONF_CM_CACHABLE_ACCELERATED
463 CONFIG_SYS_XWAY_EBU_BOOTCFG
465 Special option for Lantiq XWAY SoCs for booting from NOR flash.
466 See also arch/mips/cpu/mips32/start.S.
468 CONFIG_XWAY_SWAP_BYTES
470 Enable compilation of tools/xway-swap-bytes needed for Lantiq
471 XWAY SoCs for booting from NOR flash. The U-Boot image needs to
472 be swapped if a flash programmer is used.
475 CONFIG_SYS_EXCEPTION_VECTORS_HIGH
477 Select high exception vectors of the ARM core, e.g., do not
478 clear the V bit of the c1 register of CP15.
480 CONFIG_SYS_THUMB_BUILD
482 Use this flag to build U-Boot using the Thumb instruction
483 set for ARM architectures. Thumb instruction set provides
484 better code density. For ARM architectures that support
485 Thumb2 this flag will result in Thumb2 code generated by
488 CONFIG_ARM_ERRATA_716044
489 CONFIG_ARM_ERRATA_742230
490 CONFIG_ARM_ERRATA_743622
491 CONFIG_ARM_ERRATA_751472
493 If set, the workarounds for these ARM errata are applied early
494 during U-Boot startup. Note that these options force the
495 workarounds to be applied; no CPU-type/version detection
496 exists, unlike the similar options in the Linux kernel. Do not
497 set these options unless they apply!
502 The frequency of the timer returned by get_timer().
503 get_timer() must operate in milliseconds and this CONFIG
504 option must be set to 1000.
506 - Linux Kernel Interface:
509 U-Boot stores all clock information in Hz
510 internally. For binary compatibility with older Linux
511 kernels (which expect the clocks passed in the
512 bd_info data to be in MHz) the environment variable
513 "clocks_in_mhz" can be defined so that U-Boot
514 converts clock data to MHZ before passing it to the
516 When CONFIG_CLOCKS_IN_MHZ is defined, a definition of
517 "clocks_in_mhz=1" is automatically included in the
520 CONFIG_MEMSIZE_IN_BYTES [relevant for MIPS only]
522 When transferring memsize parameter to linux, some versions
523 expect it to be in bytes, others in MB.
524 Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes.
528 New kernel versions are expecting firmware settings to be
529 passed using flattened device trees (based on open firmware
533 * New libfdt-based support
534 * Adds the "fdt" command
535 * The bootm command automatically updates the fdt
537 OF_CPU - The proper name of the cpus node (only required for
538 MPC512X and MPC5xxx based boards).
539 OF_SOC - The proper name of the soc node (only required for
540 MPC512X and MPC5xxx based boards).
541 OF_TBCLK - The timebase frequency.
542 OF_STDOUT_PATH - The path to the console device
544 boards with QUICC Engines require OF_QE to set UCC MAC
547 CONFIG_OF_BOARD_SETUP
549 Board code has addition modification that it wants to make
550 to the flat device tree before handing it off to the kernel
554 This define fills in the correct boot CPU in the boot
555 param header, the default value is zero if undefined.
559 U-Boot can detect if an IDE device is present or not.
560 If not, and this new config option is activated, U-Boot
561 removes the ATA node from the DTS before booting Linux,
562 so the Linux IDE driver does not probe the device and
563 crash. This is needed for buggy hardware (uc101) where
564 no pull down resistor is connected to the signal IDE5V_DD7.
566 CONFIG_MACH_TYPE [relevant for ARM only][mandatory]
568 This setting is mandatory for all boards that have only one
569 machine type and must be used to specify the machine type
570 number as it appears in the ARM machine registry
571 (see http://www.arm.linux.org.uk/developer/machines/).
572 Only boards that have multiple machine types supported
573 in a single configuration file and the machine type is
574 runtime discoverable, do not have to use this setting.
576 - vxWorks boot parameters:
578 bootvx constructs a valid bootline using the following
579 environments variables: bootfile, ipaddr, serverip, hostname.
580 It loads the vxWorks image pointed bootfile.
582 CONFIG_SYS_VXWORKS_BOOT_DEVICE - The vxworks device name
583 CONFIG_SYS_VXWORKS_MAC_PTR - Ethernet 6 byte MA -address
584 CONFIG_SYS_VXWORKS_SERVERNAME - Name of the server
585 CONFIG_SYS_VXWORKS_BOOT_ADDR - Address of boot parameters
587 CONFIG_SYS_VXWORKS_ADD_PARAMS
589 Add it at the end of the bootline. E.g "u=username pw=secret"
591 Note: If a "bootargs" environment is defined, it will overwride
592 the defaults discussed just above.
594 - Cache Configuration:
595 CONFIG_SYS_ICACHE_OFF - Do not enable instruction cache in U-Boot
596 CONFIG_SYS_DCACHE_OFF - Do not enable data cache in U-Boot
597 CONFIG_SYS_L2CACHE_OFF- Do not enable L2 cache in U-Boot
599 - Cache Configuration for ARM:
600 CONFIG_SYS_L2_PL310 - Enable support for ARM PL310 L2 cache
602 CONFIG_SYS_PL310_BASE - Physical base address of PL310
603 controller register space
608 Define this if you want support for Amba PrimeCell PL010 UARTs.
612 Define this if you want support for Amba PrimeCell PL011 UARTs.
616 If you have Amba PrimeCell PL011 UARTs, set this variable to
617 the clock speed of the UARTs.
621 If you have Amba PrimeCell PL010 or PL011 UARTs on your board,
622 define this to a list of base addresses for each (supported)
623 port. See e.g. include/configs/versatile.h
625 CONFIG_PL011_SERIAL_RLCR
627 Some vendor versions of PL011 serial ports (e.g. ST-Ericsson U8500)
628 have separate receive and transmit line control registers. Set
629 this variable to initialize the extra register.
631 CONFIG_PL011_SERIAL_FLUSH_ON_INIT
633 On some platforms (e.g. U8500) U-Boot is loaded by a second stage
634 boot loader that has already initialized the UART. Define this
635 variable to flush the UART at init time.
637 CONFIG_SYS_NS16550_BROKEN_TEMT
639 16550 UART set the Transmitter Empty (TEMT) Bit when all output
640 has finished and the transmitter is totally empty. U-Boot waits
641 for this bit to be set to initialize the serial console. On some
642 broken platforms this bit is not set in SPL making U-Boot to
643 hang while waiting for TEMT. Define this option to avoid it.
647 Depending on board, define exactly one serial port
648 (like CONFIG_8xx_CONS_SMC1, CONFIG_8xx_CONS_SMC2,
649 CONFIG_8xx_CONS_SCC1, ...), or switch off the serial
650 console by defining CONFIG_8xx_CONS_NONE
652 Note: if CONFIG_8xx_CONS_NONE is defined, the serial
653 port routines must be defined elsewhere
654 (i.e. serial_init(), serial_getc(), ...)
657 Enables console device for a color framebuffer. Needs following
658 defines (cf. smiLynxEM, i8042)
659 VIDEO_FB_LITTLE_ENDIAN graphic memory organisation
661 VIDEO_HW_RECTFILL graphic chip supports
664 VIDEO_HW_BITBLT graphic chip supports
665 bit-blit (cf. smiLynxEM)
666 VIDEO_VISIBLE_COLS visible pixel columns
668 VIDEO_VISIBLE_ROWS visible pixel rows
669 VIDEO_PIXEL_SIZE bytes per pixel
670 VIDEO_DATA_FORMAT graphic data format
671 (0-5, cf. cfb_console.c)
672 VIDEO_FB_ADRS framebuffer address
673 VIDEO_KBD_INIT_FCT keyboard int fct
674 (i.e. i8042_kbd_init())
675 VIDEO_TSTC_FCT test char fct
677 VIDEO_GETC_FCT get char fct
679 CONFIG_CONSOLE_CURSOR cursor drawing on/off
680 (requires blink timer
682 CONFIG_SYS_CONSOLE_BLINK_COUNT blink interval (cf. i8042.c)
683 CONFIG_CONSOLE_TIME display time/date info in
685 (requires CONFIG_CMD_DATE)
686 CONFIG_VIDEO_LOGO display Linux logo in
688 CONFIG_VIDEO_BMP_LOGO use bmp_logo.h instead of
689 linux_logo.h for logo.
690 Requires CONFIG_VIDEO_LOGO
691 CONFIG_CONSOLE_EXTRA_INFO
692 additional board info beside
695 When CONFIG_CFB_CONSOLE_ANSI is defined, console will support
696 a limited number of ANSI escape sequences (cursor control,
697 erase functions and limited graphics rendition control).
699 When CONFIG_CFB_CONSOLE is defined, video console is
700 default i/o. Serial console can be forced with
701 environment 'console=serial'.
703 When CONFIG_SILENT_CONSOLE is defined, all console
704 messages (by U-Boot and Linux!) can be silenced with
705 the "silent" environment variable. See
706 doc/README.silent for more information.
709 CONFIG_BAUDRATE - in bps
710 Select one of the baudrates listed in
711 CONFIG_SYS_BAUDRATE_TABLE, see below.
712 CONFIG_SYS_BRGCLK_PRESCALE, baudrate prescale
714 - Console Rx buffer length
715 With CONFIG_SYS_SMC_RXBUFLEN it is possible to define
716 the maximum receive buffer length for the SMC.
717 This option is actual only for 82xx and 8xx possible.
718 If using CONFIG_SYS_SMC_RXBUFLEN also CONFIG_SYS_MAXIDLE
719 must be defined, to setup the maximum idle timeout for
722 - Pre-Console Buffer:
723 Prior to the console being initialised (i.e. serial UART
724 initialised etc) all console output is silently discarded.
725 Defining CONFIG_PRE_CONSOLE_BUFFER will cause U-Boot to
726 buffer any console messages prior to the console being
727 initialised to a buffer of size CONFIG_PRE_CON_BUF_SZ
728 bytes located at CONFIG_PRE_CON_BUF_ADDR. The buffer is
729 a circular buffer, so if more than CONFIG_PRE_CON_BUF_SZ
730 bytes are output before the console is initialised, the
731 earlier bytes are discarded.
733 'Sane' compilers will generate smaller code if
734 CONFIG_PRE_CON_BUF_SZ is a power of 2
736 - Safe printf() functions
737 Define CONFIG_SYS_VSNPRINTF to compile in safe versions of
738 the printf() functions. These are defined in
739 include/vsprintf.h and include snprintf(), vsnprintf() and
740 so on. Code size increase is approximately 300-500 bytes.
741 If this option is not given then these functions will
742 silently discard their buffer size argument - this means
743 you are not getting any overflow checking in this case.
745 - Boot Delay: CONFIG_BOOTDELAY - in seconds
746 Delay before automatically booting the default image;
747 set to -1 to disable autoboot.
748 set to -2 to autoboot with no delay and not check for abort
749 (even when CONFIG_ZERO_BOOTDELAY_CHECK is defined).
751 See doc/README.autoboot for these options that
752 work with CONFIG_BOOTDELAY. None are required.
753 CONFIG_BOOT_RETRY_TIME
754 CONFIG_BOOT_RETRY_MIN
755 CONFIG_AUTOBOOT_KEYED
756 CONFIG_AUTOBOOT_PROMPT
757 CONFIG_AUTOBOOT_DELAY_STR
758 CONFIG_AUTOBOOT_STOP_STR
759 CONFIG_AUTOBOOT_DELAY_STR2
760 CONFIG_AUTOBOOT_STOP_STR2
761 CONFIG_ZERO_BOOTDELAY_CHECK
762 CONFIG_RESET_TO_RETRY
766 Only needed when CONFIG_BOOTDELAY is enabled;
767 define a command string that is automatically executed
768 when no character is read on the console interface
769 within "Boot Delay" after reset.
772 This can be used to pass arguments to the bootm
773 command. The value of CONFIG_BOOTARGS goes into the
774 environment value "bootargs".
776 CONFIG_RAMBOOT and CONFIG_NFSBOOT
777 The value of these goes into the environment as
778 "ramboot" and "nfsboot" respectively, and can be used
779 as a convenience, when switching between booting from
785 When this option is #defined, the existence of the
786 environment variable "preboot" will be checked
787 immediately before starting the CONFIG_BOOTDELAY
788 countdown and/or running the auto-boot command resp.
789 entering interactive mode.
791 This feature is especially useful when "preboot" is
792 automatically generated or modified. For an example
793 see the LWMON board specific code: here "preboot" is
794 modified when the user holds down a certain
795 combination of keys on the (special) keyboard when
798 - Serial Download Echo Mode:
800 If defined to 1, all characters received during a
801 serial download (using the "loads" command) are
802 echoed back. This might be needed by some terminal
803 emulations (like "cu"), but may as well just take
804 time on others. This setting #define's the initial
805 value of the "loads_echo" environment variable.
807 - Kgdb Serial Baudrate: (if CONFIG_CMD_KGDB is defined)
809 Select one of the baudrates listed in
810 CONFIG_SYS_BAUDRATE_TABLE, see below.
813 Monitor commands can be included or excluded
814 from the build by using the #include files
815 <config_cmd_all.h> and #undef'ing unwanted
816 commands, or using <config_cmd_default.h>
817 and augmenting with additional #define's
820 The default command configuration includes all commands
821 except those marked below with a "*".
823 CONFIG_CMD_ASKENV * ask for env variable
824 CONFIG_CMD_BDI bdinfo
825 CONFIG_CMD_BEDBUG * Include BedBug Debugger
826 CONFIG_CMD_BMP * BMP support
827 CONFIG_CMD_BSP * Board specific commands
828 CONFIG_CMD_BOOTD bootd
829 CONFIG_CMD_CACHE * icache, dcache
830 CONFIG_CMD_CONSOLE coninfo
831 CONFIG_CMD_CRC32 * crc32
832 CONFIG_CMD_DATE * support for RTC, date/time...
833 CONFIG_CMD_DHCP * DHCP support
834 CONFIG_CMD_DIAG * Diagnostics
835 CONFIG_CMD_DS4510 * ds4510 I2C gpio commands
836 CONFIG_CMD_DS4510_INFO * ds4510 I2C info command
837 CONFIG_CMD_DS4510_MEM * ds4510 I2C eeprom/sram commansd
838 CONFIG_CMD_DS4510_RST * ds4510 I2C rst command
839 CONFIG_CMD_DTT * Digital Therm and Thermostat
840 CONFIG_CMD_ECHO echo arguments
841 CONFIG_CMD_EDITENV edit env variable
842 CONFIG_CMD_EEPROM * EEPROM read/write support
843 CONFIG_CMD_ELF * bootelf, bootvx
844 CONFIG_CMD_ENV_CALLBACK * display details about env callbacks
845 CONFIG_CMD_ENV_FLAGS * display details about env flags
846 CONFIG_CMD_EXPORTENV * export the environment
847 CONFIG_CMD_EXT2 * ext2 command support
848 CONFIG_CMD_EXT4 * ext4 command support
849 CONFIG_CMD_SAVEENV saveenv
850 CONFIG_CMD_FDC * Floppy Disk Support
851 CONFIG_CMD_FAT * FAT command support
852 CONFIG_CMD_FDOS * Dos diskette Support
853 CONFIG_CMD_FLASH flinfo, erase, protect
854 CONFIG_CMD_FPGA FPGA device initialization support
855 CONFIG_CMD_GETTIME * Get time since boot
856 CONFIG_CMD_GO * the 'go' command (exec code)
857 CONFIG_CMD_GREPENV * search environment
858 CONFIG_CMD_HASH * calculate hash / digest
859 CONFIG_CMD_HWFLOW * RTS/CTS hw flow control
860 CONFIG_CMD_I2C * I2C serial bus support
861 CONFIG_CMD_IDE * IDE harddisk support
862 CONFIG_CMD_IMI iminfo
863 CONFIG_CMD_IMLS List all images found in NOR flash
864 CONFIG_CMD_IMLS_NAND List all images found in NAND flash
865 CONFIG_CMD_IMMAP * IMMR dump support
866 CONFIG_CMD_IMPORTENV * import an environment
867 CONFIG_CMD_INI * import data from an ini file into the env
868 CONFIG_CMD_IRQ * irqinfo
869 CONFIG_CMD_ITEST Integer/string test of 2 values
870 CONFIG_CMD_JFFS2 * JFFS2 Support
871 CONFIG_CMD_KGDB * kgdb
872 CONFIG_CMD_LDRINFO ldrinfo (display Blackfin loader)
873 CONFIG_CMD_LINK_LOCAL * link-local IP address auto-configuration
875 CONFIG_CMD_LOADB loadb
876 CONFIG_CMD_LOADS loads
877 CONFIG_CMD_MD5SUM print md5 message digest
878 (requires CONFIG_CMD_MEMORY and CONFIG_MD5)
879 CONFIG_CMD_MEMINFO * Display detailed memory information
880 CONFIG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base,
882 CONFIG_CMD_MEMTEST mtest
883 CONFIG_CMD_MISC Misc functions like sleep etc
884 CONFIG_CMD_MMC * MMC memory mapped support
885 CONFIG_CMD_MII * MII utility commands
886 CONFIG_CMD_MTDPARTS * MTD partition support
887 CONFIG_CMD_NAND * NAND support
888 CONFIG_CMD_NET bootp, tftpboot, rarpboot
889 CONFIG_CMD_PCA953X * PCA953x I2C gpio commands
890 CONFIG_CMD_PCA953X_INFO * PCA953x I2C gpio info command
891 CONFIG_CMD_PCI * pciinfo
892 CONFIG_CMD_PCMCIA * PCMCIA support
893 CONFIG_CMD_PING * send ICMP ECHO_REQUEST to network
895 CONFIG_CMD_PORTIO * Port I/O
896 CONFIG_CMD_READ * Read raw data from partition
897 CONFIG_CMD_REGINFO * Register dump
898 CONFIG_CMD_RUN run command in env variable
899 CONFIG_CMD_SANDBOX * sb command to access sandbox features
900 CONFIG_CMD_SAVES * save S record dump
901 CONFIG_CMD_SCSI * SCSI Support
902 CONFIG_CMD_SDRAM * print SDRAM configuration information
903 (requires CONFIG_CMD_I2C)
904 CONFIG_CMD_SETGETDCR Support for DCR Register access
906 CONFIG_CMD_SF * Read/write/erase SPI NOR flash
907 CONFIG_CMD_SHA1SUM print sha1 memory digest
908 (requires CONFIG_CMD_MEMORY)
909 CONFIG_CMD_SOURCE "source" command Support
910 CONFIG_CMD_SPI * SPI serial bus support
911 CONFIG_CMD_TFTPSRV * TFTP transfer in server mode
912 CONFIG_CMD_TFTPPUT * TFTP put command (upload)
913 CONFIG_CMD_TIME * run command and report execution time (ARM specific)
914 CONFIG_CMD_TIMER * access to the system tick timer
915 CONFIG_CMD_USB * USB support
916 CONFIG_CMD_CDP * Cisco Discover Protocol support
917 CONFIG_CMD_MFSL * Microblaze FSL support
920 EXAMPLE: If you want all functions except of network
921 support you can write:
923 #include "config_cmd_all.h"
924 #undef CONFIG_CMD_NET
927 fdt (flattened device tree) command: CONFIG_OF_LIBFDT
929 Note: Don't enable the "icache" and "dcache" commands
930 (configuration option CONFIG_CMD_CACHE) unless you know
931 what you (and your U-Boot users) are doing. Data
932 cache cannot be enabled on systems like the 8xx or
933 8260 (where accesses to the IMMR region must be
934 uncached), and it cannot be disabled on all other
935 systems where we (mis-) use the data cache to hold an
936 initial stack and some data.
939 XXX - this list needs to get updated!
943 If this variable is defined, U-Boot will use a device tree
944 to configure its devices, instead of relying on statically
945 compiled #defines in the board file. This option is
946 experimental and only available on a few boards. The device
947 tree is available in the global data as gd->fdt_blob.
949 U-Boot needs to get its device tree from somewhere. This can
950 be done using one of the two options below:
953 If this variable is defined, U-Boot will embed a device tree
954 binary in its image. This device tree file should be in the
955 board directory and called <soc>-<board>.dts. The binary file
956 is then picked up in board_init_f() and made available through
957 the global data structure as gd->blob.
960 If this variable is defined, U-Boot will build a device tree
961 binary. It will be called u-boot.dtb. Architecture-specific
962 code will locate it at run-time. Generally this works by:
964 cat u-boot.bin u-boot.dtb >image.bin
966 and in fact, U-Boot does this for you, creating a file called
967 u-boot-dtb.bin which is useful in the common case. You can
968 still use the individual files if you need something more
973 If this variable is defined, it enables watchdog
974 support for the SoC. There must be support in the SoC
975 specific code for a watchdog. For the 8xx and 8260
976 CPUs, the SIU Watchdog feature is enabled in the SYPCR
977 register. When supported for a specific SoC is
978 available, then no further board specific code should
982 When using a watchdog circuitry external to the used
983 SoC, then define this variable and provide board
984 specific code for the "hw_watchdog_reset" function.
987 CONFIG_VERSION_VARIABLE
988 If this variable is defined, an environment variable
989 named "ver" is created by U-Boot showing the U-Boot
990 version as printed by the "version" command.
991 Any change to this variable will be reverted at the
996 When CONFIG_CMD_DATE is selected, the type of the RTC
997 has to be selected, too. Define exactly one of the
1000 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx
1001 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC
1002 CONFIG_RTC_MC13XXX - use MC13783 or MC13892 RTC
1003 CONFIG_RTC_MC146818 - use MC146818 RTC
1004 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC
1005 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC
1006 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC
1007 CONFIG_RTC_DS164x - use Dallas DS164x RTC
1008 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC
1009 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC
1010 CONFIG_SYS_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337
1011 CONFIG_SYS_RV3029_TCR - enable trickle charger on
1014 Note that if the RTC uses I2C, then the I2C interface
1015 must also be configured. See I2C Support, below.
1018 CONFIG_PCA953X - use NXP's PCA953X series I2C GPIO
1019 CONFIG_PCA953X_INFO - enable pca953x info command
1021 The CONFIG_SYS_I2C_PCA953X_WIDTH option specifies a list of
1022 chip-ngpio pairs that tell the PCA953X driver the number of
1023 pins supported by a particular chip.
1025 Note that if the GPIO device uses I2C, then the I2C interface
1026 must also be configured. See I2C Support, below.
1028 - Timestamp Support:
1030 When CONFIG_TIMESTAMP is selected, the timestamp
1031 (date and time) of an image is printed by image
1032 commands like bootm or iminfo. This option is
1033 automatically enabled when you select CONFIG_CMD_DATE .
1035 - Partition Labels (disklabels) Supported:
1036 Zero or more of the following:
1037 CONFIG_MAC_PARTITION Apple's MacOS partition table.
1038 CONFIG_DOS_PARTITION MS Dos partition table, traditional on the
1039 Intel architecture, USB sticks, etc.
1040 CONFIG_ISO_PARTITION ISO partition table, used on CDROM etc.
1041 CONFIG_EFI_PARTITION GPT partition table, common when EFI is the
1042 bootloader. Note 2TB partition limit; see
1044 CONFIG_MTD_PARTITIONS Memory Technology Device partition table.
1046 If IDE or SCSI support is enabled (CONFIG_CMD_IDE or
1047 CONFIG_CMD_SCSI) you must configure support for at
1048 least one non-MTD partition type as well.
1051 CONFIG_IDE_RESET_ROUTINE - this is defined in several
1052 board configurations files but used nowhere!
1054 CONFIG_IDE_RESET - is this is defined, IDE Reset will
1055 be performed by calling the function
1056 ide_set_reset(int reset)
1057 which has to be defined in a board specific file
1062 Set this to enable ATAPI support.
1067 Set this to enable support for disks larger than 137GB
1068 Also look at CONFIG_SYS_64BIT_LBA.
1069 Whithout these , LBA48 support uses 32bit variables and will 'only'
1070 support disks up to 2.1TB.
1072 CONFIG_SYS_64BIT_LBA:
1073 When enabled, makes the IDE subsystem use 64bit sector addresses.
1077 At the moment only there is only support for the
1078 SYM53C8XX SCSI controller; define
1079 CONFIG_SCSI_SYM53C8XX to enable it.
1081 CONFIG_SYS_SCSI_MAX_LUN [8], CONFIG_SYS_SCSI_MAX_SCSI_ID [7] and
1082 CONFIG_SYS_SCSI_MAX_DEVICE [CONFIG_SYS_SCSI_MAX_SCSI_ID *
1083 CONFIG_SYS_SCSI_MAX_LUN] can be adjusted to define the
1084 maximum numbers of LUNs, SCSI ID's and target
1086 CONFIG_SYS_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz)
1088 The environment variable 'scsidevs' is set to the number of
1089 SCSI devices found during the last scan.
1091 - NETWORK Support (PCI):
1093 Support for Intel 8254x/8257x gigabit chips.
1096 Utility code for direct access to the SPI bus on Intel 8257x.
1097 This does not do anything useful unless you set at least one
1098 of CONFIG_CMD_E1000 or CONFIG_E1000_SPI_GENERIC.
1100 CONFIG_E1000_SPI_GENERIC
1101 Allow generic access to the SPI bus on the Intel 8257x, for
1102 example with the "sspi" command.
1105 Management command for E1000 devices. When used on devices
1106 with SPI support you can reprogram the EEPROM from U-Boot.
1108 CONFIG_E1000_FALLBACK_MAC
1109 default MAC for empty EEPROM after production.
1112 Support for Intel 82557/82559/82559ER chips.
1113 Optional CONFIG_EEPRO100_SROM_WRITE enables EEPROM
1114 write routine for first time initialisation.
1117 Support for Digital 2114x chips.
1118 Optional CONFIG_TULIP_SELECT_MEDIA for board specific
1119 modem chip initialisation (KS8761/QS6611).
1122 Support for National dp83815 chips.
1125 Support for National dp8382[01] gigabit chips.
1127 - NETWORK Support (other):
1129 CONFIG_DRIVER_AT91EMAC
1130 Support for AT91RM9200 EMAC.
1133 Define this to use reduced MII inteface
1135 CONFIG_DRIVER_AT91EMAC_QUIET
1136 If this defined, the driver is quiet.
1137 The driver doen't show link status messages.
1139 CONFIG_CALXEDA_XGMAC
1140 Support for the Calxeda XGMAC device
1143 Support for SMSC's LAN91C96 chips.
1145 CONFIG_LAN91C96_BASE
1146 Define this to hold the physical address
1147 of the LAN91C96's I/O space
1149 CONFIG_LAN91C96_USE_32_BIT
1150 Define this to enable 32 bit addressing
1153 Support for SMSC's LAN91C111 chip
1155 CONFIG_SMC91111_BASE
1156 Define this to hold the physical address
1157 of the device (I/O space)
1159 CONFIG_SMC_USE_32_BIT
1160 Define this if data bus is 32 bits
1162 CONFIG_SMC_USE_IOFUNCS
1163 Define this to use i/o functions instead of macros
1164 (some hardware wont work with macros)
1166 CONFIG_DRIVER_TI_EMAC
1167 Support for davinci emac
1169 CONFIG_SYS_DAVINCI_EMAC_PHY_COUNT
1170 Define this if you have more then 3 PHYs.
1173 Support for Faraday's FTGMAC100 Gigabit SoC Ethernet
1175 CONFIG_FTGMAC100_EGIGA
1176 Define this to use GE link update with gigabit PHY.
1177 Define this if FTGMAC100 is connected to gigabit PHY.
1178 If your system has 10/100 PHY only, it might not occur
1179 wrong behavior. Because PHY usually return timeout or
1180 useless data when polling gigabit status and gigabit
1181 control registers. This behavior won't affect the
1182 correctnessof 10/100 link speed update.
1185 Support for SMSC's LAN911x and LAN921x chips
1188 Define this to hold the physical address
1189 of the device (I/O space)
1191 CONFIG_SMC911X_32_BIT
1192 Define this if data bus is 32 bits
1194 CONFIG_SMC911X_16_BIT
1195 Define this if data bus is 16 bits. If your processor
1196 automatically converts one 32 bit word to two 16 bit
1197 words you may also try CONFIG_SMC911X_32_BIT.
1200 Support for Renesas on-chip Ethernet controller
1202 CONFIG_SH_ETHER_USE_PORT
1203 Define the number of ports to be used
1205 CONFIG_SH_ETHER_PHY_ADDR
1206 Define the ETH PHY's address
1208 CONFIG_SH_ETHER_CACHE_WRITEBACK
1209 If this option is set, the driver enables cache flush.
1212 CONFIG_GENERIC_LPC_TPM
1213 Support for generic parallel port TPM devices. Only one device
1214 per system is supported at this time.
1216 CONFIG_TPM_TIS_BASE_ADDRESS
1217 Base address where the generic TPM device is mapped
1218 to. Contemporary x86 systems usually map it at
1222 At the moment only the UHCI host controller is
1223 supported (PIP405, MIP405, MPC5200); define
1224 CONFIG_USB_UHCI to enable it.
1225 define CONFIG_USB_KEYBOARD to enable the USB Keyboard
1226 and define CONFIG_USB_STORAGE to enable the USB
1229 Supported are USB Keyboards and USB Floppy drives
1231 MPC5200 USB requires additional defines:
1233 for 528 MHz Clock: 0x0001bbbb
1237 for differential drivers: 0x00001000
1238 for single ended drivers: 0x00005000
1239 for differential drivers on PSC3: 0x00000100
1240 for single ended drivers on PSC3: 0x00004100
1241 CONFIG_SYS_USB_EVENT_POLL
1242 May be defined to allow interrupt polling
1243 instead of using asynchronous interrupts
1245 CONFIG_USB_EHCI_TXFIFO_THRESH enables setting of the
1246 txfilltuning field in the EHCI controller on reset.
1249 Define the below if you wish to use the USB console.
1250 Once firmware is rebuilt from a serial console issue the
1251 command "setenv stdin usbtty; setenv stdout usbtty" and
1252 attach your USB cable. The Unix command "dmesg" should print
1253 it has found a new device. The environment variable usbtty
1254 can be set to gserial or cdc_acm to enable your device to
1255 appear to a USB host as a Linux gserial device or a
1256 Common Device Class Abstract Control Model serial device.
1257 If you select usbtty = gserial you should be able to enumerate
1259 # modprobe usbserial vendor=0xVendorID product=0xProductID
1260 else if using cdc_acm, simply setting the environment
1261 variable usbtty to be cdc_acm should suffice. The following
1262 might be defined in YourBoardName.h
1265 Define this to build a UDC device
1268 Define this to have a tty type of device available to
1269 talk to the UDC device
1272 Define this to enable the high speed support for usb
1273 device and usbtty. If this feature is enabled, a routine
1274 int is_usbd_high_speed(void)
1275 also needs to be defined by the driver to dynamically poll
1276 whether the enumeration has succeded at high speed or full
1279 CONFIG_SYS_CONSOLE_IS_IN_ENV
1280 Define this if you want stdin, stdout &/or stderr to
1284 CONFIG_SYS_USB_EXTC_CLK 0xBLAH
1285 Derive USB clock from external clock "blah"
1286 - CONFIG_SYS_USB_EXTC_CLK 0x02
1288 CONFIG_SYS_USB_BRG_CLK 0xBLAH
1289 Derive USB clock from brgclk
1290 - CONFIG_SYS_USB_BRG_CLK 0x04
1292 If you have a USB-IF assigned VendorID then you may wish to
1293 define your own vendor specific values either in BoardName.h
1294 or directly in usbd_vendor_info.h. If you don't define
1295 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME,
1296 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot
1297 should pretend to be a Linux device to it's target host.
1299 CONFIG_USBD_MANUFACTURER
1300 Define this string as the name of your company for
1301 - CONFIG_USBD_MANUFACTURER "my company"
1303 CONFIG_USBD_PRODUCT_NAME
1304 Define this string as the name of your product
1305 - CONFIG_USBD_PRODUCT_NAME "acme usb device"
1307 CONFIG_USBD_VENDORID
1308 Define this as your assigned Vendor ID from the USB
1309 Implementors Forum. This *must* be a genuine Vendor ID
1310 to avoid polluting the USB namespace.
1311 - CONFIG_USBD_VENDORID 0xFFFF
1313 CONFIG_USBD_PRODUCTID
1314 Define this as the unique Product ID
1316 - CONFIG_USBD_PRODUCTID 0xFFFF
1318 - ULPI Layer Support:
1319 The ULPI (UTMI Low Pin (count) Interface) PHYs are supported via
1320 the generic ULPI layer. The generic layer accesses the ULPI PHY
1321 via the platform viewport, so you need both the genric layer and
1322 the viewport enabled. Currently only Chipidea/ARC based
1323 viewport is supported.
1324 To enable the ULPI layer support, define CONFIG_USB_ULPI and
1325 CONFIG_USB_ULPI_VIEWPORT in your board configuration file.
1326 If your ULPI phy needs a different reference clock than the
1327 standard 24 MHz then you have to define CONFIG_ULPI_REF_CLK to
1328 the appropriate value in Hz.
1331 The MMC controller on the Intel PXA is supported. To
1332 enable this define CONFIG_MMC. The MMC can be
1333 accessed from the boot prompt by mapping the device
1334 to physical memory similar to flash. Command line is
1335 enabled with CONFIG_CMD_MMC. The MMC driver also works with
1336 the FAT fs. This is enabled with CONFIG_CMD_FAT.
1339 Support for Renesas on-chip MMCIF controller
1341 CONFIG_SH_MMCIF_ADDR
1342 Define the base address of MMCIF registers
1345 Define the clock frequency for MMCIF
1347 - USB Device Firmware Update (DFU) class support:
1349 This enables the USB portion of the DFU USB class
1352 This enables the command "dfu" which is used to have
1353 U-Boot create a DFU class device via USB. This command
1354 requires that the "dfu_alt_info" environment variable be
1355 set and define the alt settings to expose to the host.
1358 This enables support for exposing (e)MMC devices via DFU.
1360 - Journaling Flash filesystem support:
1361 CONFIG_JFFS2_NAND, CONFIG_JFFS2_NAND_OFF, CONFIG_JFFS2_NAND_SIZE,
1362 CONFIG_JFFS2_NAND_DEV
1363 Define these for a default partition on a NAND device
1365 CONFIG_SYS_JFFS2_FIRST_SECTOR,
1366 CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS
1367 Define these for a default partition on a NOR device
1369 CONFIG_SYS_JFFS_CUSTOM_PART
1370 Define this to create an own partition. You have to provide a
1371 function struct part_info* jffs2_part_info(int part_num)
1373 If you define only one JFFS2 partition you may also want to
1374 #define CONFIG_SYS_JFFS_SINGLE_PART 1
1375 to disable the command chpart. This is the default when you
1376 have not defined a custom partition
1378 - FAT(File Allocation Table) filesystem write function support:
1381 Define this to enable support for saving memory data as a
1382 file in FAT formatted partition.
1384 This will also enable the command "fatwrite" enabling the
1385 user to write files to FAT.
1387 CBFS (Coreboot Filesystem) support
1390 Define this to enable support for reading from a Coreboot
1391 filesystem. Available commands are cbfsinit, cbfsinfo, cbfsls
1397 Define this to enable standard (PC-Style) keyboard
1401 Standard PC keyboard driver with US (is default) and
1402 GERMAN key layout (switch via environment 'keymap=de') support.
1403 Export function i8042_kbd_init, i8042_tstc and i8042_getc
1404 for cfb_console. Supports cursor blinking.
1409 Define this to enable video support (for output to
1412 CONFIG_VIDEO_CT69000
1414 Enable Chips & Technologies 69000 Video chip
1416 CONFIG_VIDEO_SMI_LYNXEM
1417 Enable Silicon Motion SMI 712/710/810 Video chip. The
1418 video output is selected via environment 'videoout'
1419 (1 = LCD and 2 = CRT). If videoout is undefined, CRT is
1422 For the CT69000 and SMI_LYNXEM drivers, videomode is
1423 selected via environment 'videomode'. Two different ways
1425 - "videomode=num" 'num' is a standard LiLo mode numbers.
1426 Following standard modes are supported (* is default):
1428 Colors 640x480 800x600 1024x768 1152x864 1280x1024
1429 -------------+---------------------------------------------
1430 8 bits | 0x301* 0x303 0x305 0x161 0x307
1431 15 bits | 0x310 0x313 0x316 0x162 0x319
1432 16 bits | 0x311 0x314 0x317 0x163 0x31A
1433 24 bits | 0x312 0x315 0x318 ? 0x31B
1434 -------------+---------------------------------------------
1435 (i.e. setenv videomode 317; saveenv; reset;)
1437 - "videomode=bootargs" all the video parameters are parsed
1438 from the bootargs. (See drivers/video/videomodes.c)
1441 CONFIG_VIDEO_SED13806
1442 Enable Epson SED13806 driver. This driver supports 8bpp
1443 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP
1444 or CONFIG_VIDEO_SED13806_16BPP
1447 Enable the Freescale DIU video driver. Reference boards for
1448 SOCs that have a DIU should define this macro to enable DIU
1449 support, and should also define these other macros:
1455 CONFIG_VIDEO_SW_CURSOR
1456 CONFIG_VGA_AS_SINGLE_DEVICE
1458 CONFIG_VIDEO_BMP_LOGO
1460 The DIU driver will look for the 'video-mode' environment
1461 variable, and if defined, enable the DIU as a console during
1462 boot. See the documentation file README.video for a
1463 description of this variable.
1467 Enable the VGA video / BIOS for x86. The alternative if you
1468 are using coreboot is to use the coreboot frame buffer
1475 Define this to enable a custom keyboard support.
1476 This simply calls drv_keyboard_init() which must be
1477 defined in your board-specific files.
1478 The only board using this so far is RBC823.
1480 - LCD Support: CONFIG_LCD
1482 Define this to enable LCD support (for output to LCD
1483 display); also select one of the supported displays
1484 by defining one of these:
1488 HITACHI TX09D70VM1CCA, 3.5", 240x320.
1490 CONFIG_NEC_NL6448AC33:
1492 NEC NL6448AC33-18. Active, color, single scan.
1494 CONFIG_NEC_NL6448BC20
1496 NEC NL6448BC20-08. 6.5", 640x480.
1497 Active, color, single scan.
1499 CONFIG_NEC_NL6448BC33_54
1501 NEC NL6448BC33-54. 10.4", 640x480.
1502 Active, color, single scan.
1506 Sharp 320x240. Active, color, single scan.
1507 It isn't 16x9, and I am not sure what it is.
1509 CONFIG_SHARP_LQ64D341
1511 Sharp LQ64D341 display, 640x480.
1512 Active, color, single scan.
1516 HLD1045 display, 640x480.
1517 Active, color, single scan.
1521 Optrex CBL50840-2 NF-FW 99 22 M5
1523 Hitachi LMG6912RPFC-00T
1527 320x240. Black & white.
1529 Normally display is black on white background; define
1530 CONFIG_SYS_WHITE_ON_BLACK to get it inverted.
1532 CONFIG_LCD_ALIGNMENT
1534 Normally the LCD is page-aligned (tyically 4KB). If this is
1535 defined then the LCD will be aligned to this value instead.
1536 For ARM it is sometimes useful to use MMU_SECTION_SIZE
1537 here, since it is cheaper to change data cache settings on
1538 a per-section basis.
1540 CONFIG_CONSOLE_SCROLL_LINES
1542 When the console need to be scrolled, this is the number of
1543 lines to scroll by. It defaults to 1. Increasing this makes
1544 the console jump but can help speed up operation when scrolling
1549 Support drawing of RLE8-compressed bitmaps on the LCD.
1553 Enables an 'i2c edid' command which can read EDID
1554 information over I2C from an attached LCD display.
1556 - Splash Screen Support: CONFIG_SPLASH_SCREEN
1558 If this option is set, the environment is checked for
1559 a variable "splashimage". If found, the usual display
1560 of logo, copyright and system information on the LCD
1561 is suppressed and the BMP image at the address
1562 specified in "splashimage" is loaded instead. The
1563 console is redirected to the "nulldev", too. This
1564 allows for a "silent" boot where a splash screen is
1565 loaded very quickly after power-on.
1567 CONFIG_SPLASHIMAGE_GUARD
1569 If this option is set, then U-Boot will prevent the environment
1570 variable "splashimage" from being set to a problematic address
1571 (see README.displaying-bmps and README.arm-unaligned-accesses).
1572 This option is useful for targets where, due to alignment
1573 restrictions, an improperly aligned BMP image will cause a data
1574 abort. If you think you will not have problems with unaligned
1575 accesses (for example because your toolchain prevents them)
1576 there is no need to set this option.
1578 CONFIG_SPLASH_SCREEN_ALIGN
1580 If this option is set the splash image can be freely positioned
1581 on the screen. Environment variable "splashpos" specifies the
1582 position as "x,y". If a positive number is given it is used as
1583 number of pixel from left/top. If a negative number is given it
1584 is used as number of pixel from right/bottom. You can also
1585 specify 'm' for centering the image.
1588 setenv splashpos m,m
1589 => image at center of screen
1591 setenv splashpos 30,20
1592 => image at x = 30 and y = 20
1594 setenv splashpos -10,m
1595 => vertically centered image
1596 at x = dspWidth - bmpWidth - 9
1598 CONFIG_SPLASH_SCREEN_PREPARE
1600 If this option is set then the board_splash_screen_prepare()
1601 function, which must be defined in your code, is called as part
1602 of the splash screen display sequence. It gives the board an
1603 opportunity to prepare the splash image data before it is
1604 processed and sent to the frame buffer by U-Boot.
1606 - Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP
1608 If this option is set, additionally to standard BMP
1609 images, gzipped BMP images can be displayed via the
1610 splashscreen support or the bmp command.
1612 - Run length encoded BMP image (RLE8) support: CONFIG_VIDEO_BMP_RLE8
1614 If this option is set, 8-bit RLE compressed BMP images
1615 can be displayed via the splashscreen support or the
1618 - Do compresssing for memory range:
1621 If this option is set, it would use zlib deflate method
1622 to compress the specified memory at its best effort.
1624 - Compression support:
1627 If this option is set, support for bzip2 compressed
1628 images is included. If not, only uncompressed and gzip
1629 compressed images are supported.
1631 NOTE: the bzip2 algorithm requires a lot of RAM, so
1632 the malloc area (as defined by CONFIG_SYS_MALLOC_LEN) should
1637 If this option is set, support for lzma compressed
1640 Note: The LZMA algorithm adds between 2 and 4KB of code and it
1641 requires an amount of dynamic memory that is given by the
1644 (1846 + 768 << (lc + lp)) * sizeof(uint16)
1646 Where lc and lp stand for, respectively, Literal context bits
1647 and Literal pos bits.
1649 This value is upper-bounded by 14MB in the worst case. Anyway,
1650 for a ~4MB large kernel image, we have lc=3 and lp=0 for a
1651 total amount of (1846 + 768 << (3 + 0)) * 2 = ~41KB... that is
1652 a very small buffer.
1654 Use the lzmainfo tool to determinate the lc and lp values and
1655 then calculate the amount of needed dynamic memory (ensuring
1656 the appropriate CONFIG_SYS_MALLOC_LEN value).
1661 The address of PHY on MII bus.
1663 CONFIG_PHY_CLOCK_FREQ (ppc4xx)
1665 The clock frequency of the MII bus
1669 If this option is set, support for speed/duplex
1670 detection of gigabit PHY is included.
1672 CONFIG_PHY_RESET_DELAY
1674 Some PHY like Intel LXT971A need extra delay after
1675 reset before any MII register access is possible.
1676 For such PHY, set this option to the usec delay
1677 required. (minimum 300usec for LXT971A)
1679 CONFIG_PHY_CMD_DELAY (ppc4xx)
1681 Some PHY like Intel LXT971A need extra delay after
1682 command issued before MII status register can be read
1692 Define a default value for Ethernet address to use
1693 for the respective Ethernet interface, in case this
1694 is not determined automatically.
1699 Define a default value for the IP address to use for
1700 the default Ethernet interface, in case this is not
1701 determined through e.g. bootp.
1702 (Environment variable "ipaddr")
1704 - Server IP address:
1707 Defines a default value for the IP address of a TFTP
1708 server to contact when using the "tftboot" command.
1709 (Environment variable "serverip")
1711 CONFIG_KEEP_SERVERADDR
1713 Keeps the server's MAC address, in the env 'serveraddr'
1714 for passing to bootargs (like Linux's netconsole option)
1716 - Gateway IP address:
1719 Defines a default value for the IP address of the
1720 default router where packets to other networks are
1722 (Environment variable "gatewayip")
1727 Defines a default value for the subnet mask (or
1728 routing prefix) which is used to determine if an IP
1729 address belongs to the local subnet or needs to be
1730 forwarded through a router.
1731 (Environment variable "netmask")
1733 - Multicast TFTP Mode:
1736 Defines whether you want to support multicast TFTP as per
1737 rfc-2090; for example to work with atftp. Lets lots of targets
1738 tftp down the same boot image concurrently. Note: the Ethernet
1739 driver in use must provide a function: mcast() to join/leave a
1742 - BOOTP Recovery Mode:
1743 CONFIG_BOOTP_RANDOM_DELAY
1745 If you have many targets in a network that try to
1746 boot using BOOTP, you may want to avoid that all
1747 systems send out BOOTP requests at precisely the same
1748 moment (which would happen for instance at recovery
1749 from a power failure, when all systems will try to
1750 boot, thus flooding the BOOTP server. Defining
1751 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
1752 inserted before sending out BOOTP requests. The
1753 following delays are inserted then:
1755 1st BOOTP request: delay 0 ... 1 sec
1756 2nd BOOTP request: delay 0 ... 2 sec
1757 3rd BOOTP request: delay 0 ... 4 sec
1759 BOOTP requests: delay 0 ... 8 sec
1761 - DHCP Advanced Options:
1762 You can fine tune the DHCP functionality by defining
1763 CONFIG_BOOTP_* symbols:
1765 CONFIG_BOOTP_SUBNETMASK
1766 CONFIG_BOOTP_GATEWAY
1767 CONFIG_BOOTP_HOSTNAME
1768 CONFIG_BOOTP_NISDOMAIN
1769 CONFIG_BOOTP_BOOTPATH
1770 CONFIG_BOOTP_BOOTFILESIZE
1773 CONFIG_BOOTP_SEND_HOSTNAME
1774 CONFIG_BOOTP_NTPSERVER
1775 CONFIG_BOOTP_TIMEOFFSET
1776 CONFIG_BOOTP_VENDOREX
1777 CONFIG_BOOTP_MAY_FAIL
1779 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip
1780 environment variable, not the BOOTP server.
1782 CONFIG_BOOTP_MAY_FAIL - If the DHCP server is not found
1783 after the configured retry count, the call will fail
1784 instead of starting over. This can be used to fail over
1785 to Link-local IP address configuration if the DHCP server
1788 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS
1789 serverip from a DHCP server, it is possible that more
1790 than one DNS serverip is offered to the client.
1791 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS
1792 serverip will be stored in the additional environment
1793 variable "dnsip2". The first DNS serverip is always
1794 stored in the variable "dnsip", when CONFIG_BOOTP_DNS
1797 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable
1798 to do a dynamic update of a DNS server. To do this, they
1799 need the hostname of the DHCP requester.
1800 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content
1801 of the "hostname" environment variable is passed as
1802 option 12 to the DHCP server.
1804 CONFIG_BOOTP_DHCP_REQUEST_DELAY
1806 A 32bit value in microseconds for a delay between
1807 receiving a "DHCP Offer" and sending the "DHCP Request".
1808 This fixes a problem with certain DHCP servers that don't
1809 respond 100% of the time to a "DHCP request". E.g. On an
1810 AT91RM9200 processor running at 180MHz, this delay needed
1811 to be *at least* 15,000 usec before a Windows Server 2003
1812 DHCP server would reply 100% of the time. I recommend at
1813 least 50,000 usec to be safe. The alternative is to hope
1814 that one of the retries will be successful but note that
1815 the DHCP timeout and retry process takes a longer than
1818 - Link-local IP address negotiation:
1819 Negotiate with other link-local clients on the local network
1820 for an address that doesn't require explicit configuration.
1821 This is especially useful if a DHCP server cannot be guaranteed
1822 to exist in all environments that the device must operate.
1824 See doc/README.link-local for more information.
1827 CONFIG_CDP_DEVICE_ID
1829 The device id used in CDP trigger frames.
1831 CONFIG_CDP_DEVICE_ID_PREFIX
1833 A two character string which is prefixed to the MAC address
1838 A printf format string which contains the ascii name of
1839 the port. Normally is set to "eth%d" which sets
1840 eth0 for the first Ethernet, eth1 for the second etc.
1842 CONFIG_CDP_CAPABILITIES
1844 A 32bit integer which indicates the device capabilities;
1845 0x00000010 for a normal host which does not forwards.
1849 An ascii string containing the version of the software.
1853 An ascii string containing the name of the platform.
1857 A 32bit integer sent on the trigger.
1859 CONFIG_CDP_POWER_CONSUMPTION
1861 A 16bit integer containing the power consumption of the
1862 device in .1 of milliwatts.
1864 CONFIG_CDP_APPLIANCE_VLAN_TYPE
1866 A byte containing the id of the VLAN.
1868 - Status LED: CONFIG_STATUS_LED
1870 Several configurations allow to display the current
1871 status using a LED. For instance, the LED will blink
1872 fast while running U-Boot code, stop blinking as
1873 soon as a reply to a BOOTP request was received, and
1874 start blinking slow once the Linux kernel is running
1875 (supported by a status LED driver in the Linux
1876 kernel). Defining CONFIG_STATUS_LED enables this
1879 - CAN Support: CONFIG_CAN_DRIVER
1881 Defining CONFIG_CAN_DRIVER enables CAN driver support
1882 on those systems that support this (optional)
1883 feature, like the TQM8xxL modules.
1885 - I2C Support: CONFIG_HARD_I2C | CONFIG_SOFT_I2C
1887 These enable I2C serial bus commands. Defining either of
1888 (but not both of) CONFIG_HARD_I2C or CONFIG_SOFT_I2C will
1889 include the appropriate I2C driver for the selected CPU.
1891 This will allow you to use i2c commands at the u-boot
1892 command line (as long as you set CONFIG_CMD_I2C in
1893 CONFIG_COMMANDS) and communicate with i2c based realtime
1894 clock chips. See common/cmd_i2c.c for a description of the
1895 command line interface.
1897 CONFIG_HARD_I2C selects a hardware I2C controller.
1899 CONFIG_SOFT_I2C configures u-boot to use a software (aka
1900 bit-banging) driver instead of CPM or similar hardware
1903 There are several other quantities that must also be
1904 defined when you define CONFIG_HARD_I2C or CONFIG_SOFT_I2C.
1906 In both cases you will need to define CONFIG_SYS_I2C_SPEED
1907 to be the frequency (in Hz) at which you wish your i2c bus
1908 to run and CONFIG_SYS_I2C_SLAVE to be the address of this node (ie
1909 the CPU's i2c node address).
1911 Now, the u-boot i2c code for the mpc8xx
1912 (arch/powerpc/cpu/mpc8xx/i2c.c) sets the CPU up as a master node
1913 and so its address should therefore be cleared to 0 (See,
1914 eg, MPC823e User's Manual p.16-473). So, set
1915 CONFIG_SYS_I2C_SLAVE to 0.
1917 CONFIG_SYS_I2C_INIT_MPC5XXX
1919 When a board is reset during an i2c bus transfer
1920 chips might think that the current transfer is still
1921 in progress. Reset the slave devices by sending start
1922 commands until the slave device responds.
1924 That's all that's required for CONFIG_HARD_I2C.
1926 If you use the software i2c interface (CONFIG_SOFT_I2C)
1927 then the following macros need to be defined (examples are
1928 from include/configs/lwmon.h):
1932 (Optional). Any commands necessary to enable the I2C
1933 controller or configure ports.
1935 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
1939 (Only for MPC8260 CPU). The I/O port to use (the code
1940 assumes both bits are on the same port). Valid values
1941 are 0..3 for ports A..D.
1945 The code necessary to make the I2C data line active
1946 (driven). If the data line is open collector, this
1949 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
1953 The code necessary to make the I2C data line tri-stated
1954 (inactive). If the data line is open collector, this
1957 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
1961 Code that returns true if the I2C data line is high,
1964 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
1968 If <bit> is true, sets the I2C data line high. If it
1969 is false, it clears it (low).
1971 eg: #define I2C_SDA(bit) \
1972 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
1973 else immr->im_cpm.cp_pbdat &= ~PB_SDA
1977 If <bit> is true, sets the I2C clock line high. If it
1978 is false, it clears it (low).
1980 eg: #define I2C_SCL(bit) \
1981 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
1982 else immr->im_cpm.cp_pbdat &= ~PB_SCL
1986 This delay is invoked four times per clock cycle so this
1987 controls the rate of data transfer. The data rate thus
1988 is 1 / (I2C_DELAY * 4). Often defined to be something
1991 #define I2C_DELAY udelay(2)
1993 CONFIG_SOFT_I2C_GPIO_SCL / CONFIG_SOFT_I2C_GPIO_SDA
1995 If your arch supports the generic GPIO framework (asm/gpio.h),
1996 then you may alternatively define the two GPIOs that are to be
1997 used as SCL / SDA. Any of the previous I2C_xxx macros will
1998 have GPIO-based defaults assigned to them as appropriate.
2000 You should define these to the GPIO value as given directly to
2001 the generic GPIO functions.
2003 CONFIG_SYS_I2C_INIT_BOARD
2005 When a board is reset during an i2c bus transfer
2006 chips might think that the current transfer is still
2007 in progress. On some boards it is possible to access
2008 the i2c SCLK line directly, either by using the
2009 processor pin as a GPIO or by having a second pin
2010 connected to the bus. If this option is defined a
2011 custom i2c_init_board() routine in boards/xxx/board.c
2012 is run early in the boot sequence.
2014 CONFIG_SYS_I2C_BOARD_LATE_INIT
2016 An alternative to CONFIG_SYS_I2C_INIT_BOARD. If this option is
2017 defined a custom i2c_board_late_init() routine in
2018 boards/xxx/board.c is run AFTER the operations in i2c_init()
2019 is completed. This callpoint can be used to unreset i2c bus
2020 using CPU i2c controller register accesses for CPUs whose i2c
2021 controller provide such a method. It is called at the end of
2022 i2c_init() to allow i2c_init operations to setup the i2c bus
2023 controller on the CPU (e.g. setting bus speed & slave address).
2025 CONFIG_I2CFAST (PPC405GP|PPC405EP only)
2027 This option enables configuration of bi_iic_fast[] flags
2028 in u-boot bd_info structure based on u-boot environment
2029 variable "i2cfast". (see also i2cfast)
2031 CONFIG_I2C_MULTI_BUS
2033 This option allows the use of multiple I2C buses, each of which
2034 must have a controller. At any point in time, only one bus is
2035 active. To switch to a different bus, use the 'i2c dev' command.
2036 Note that bus numbering is zero-based.
2038 CONFIG_SYS_I2C_NOPROBES
2040 This option specifies a list of I2C devices that will be skipped
2041 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS
2042 is set, specify a list of bus-device pairs. Otherwise, specify
2043 a 1D array of device addresses
2046 #undef CONFIG_I2C_MULTI_BUS
2047 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68}
2049 will skip addresses 0x50 and 0x68 on a board with one I2C bus
2051 #define CONFIG_I2C_MULTI_BUS
2052 #define CONFIG_SYS_I2C_MULTI_NOPROBES {{0,0x50},{0,0x68},{1,0x54}}
2054 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1
2056 CONFIG_SYS_SPD_BUS_NUM
2058 If defined, then this indicates the I2C bus number for DDR SPD.
2059 If not defined, then U-Boot assumes that SPD is on I2C bus 0.
2061 CONFIG_SYS_RTC_BUS_NUM
2063 If defined, then this indicates the I2C bus number for the RTC.
2064 If not defined, then U-Boot assumes that RTC is on I2C bus 0.
2066 CONFIG_SYS_DTT_BUS_NUM
2068 If defined, then this indicates the I2C bus number for the DTT.
2069 If not defined, then U-Boot assumes that DTT is on I2C bus 0.
2071 CONFIG_SYS_I2C_DTT_ADDR:
2073 If defined, specifies the I2C address of the DTT device.
2074 If not defined, then U-Boot uses predefined value for
2075 specified DTT device.
2079 Define this option if you want to use Freescale's I2C driver in
2080 drivers/i2c/fsl_i2c.c.
2084 Define this option if you have I2C devices reached over 1 .. n
2085 I2C Muxes like the pca9544a. This option addes a new I2C
2086 Command "i2c bus [muxtype:muxaddr:muxchannel]" which adds a
2087 new I2C Bus to the existing I2C Busses. If you select the
2088 new Bus with "i2c dev", u-bbot sends first the commandos for
2089 the muxes to activate this new "bus".
2091 CONFIG_I2C_MULTI_BUS must be also defined, to use this
2095 Adding a new I2C Bus reached over 2 pca9544a muxes
2096 The First mux with address 70 and channel 6
2097 The Second mux with address 71 and channel 4
2099 => i2c bus pca9544a:70:6:pca9544a:71:4
2101 Use the "i2c bus" command without parameter, to get a list
2102 of I2C Busses with muxes:
2105 Busses reached over muxes:
2107 reached over Mux(es):
2110 reached over Mux(es):
2115 If you now switch to the new I2C Bus 3 with "i2c dev 3"
2116 u-boot first sends the command to the mux@70 to enable
2117 channel 6, and then the command to the mux@71 to enable
2120 After that, you can use the "normal" i2c commands as
2121 usual to communicate with your I2C devices behind
2124 This option is actually implemented for the bitbanging
2125 algorithm in common/soft_i2c.c and for the Hardware I2C
2126 Bus on the MPC8260. But it should be not so difficult
2127 to add this option to other architectures.
2129 CONFIG_SOFT_I2C_READ_REPEATED_START
2131 defining this will force the i2c_read() function in
2132 the soft_i2c driver to perform an I2C repeated start
2133 between writing the address pointer and reading the
2134 data. If this define is omitted the default behaviour
2135 of doing a stop-start sequence will be used. Most I2C
2136 devices can use either method, but some require one or
2139 - SPI Support: CONFIG_SPI
2141 Enables SPI driver (so far only tested with
2142 SPI EEPROM, also an instance works with Crystal A/D and
2143 D/As on the SACSng board)
2147 Enables the driver for SPI controller on SuperH. Currently
2148 only SH7757 is supported.
2152 Enables extended (16-bit) SPI EEPROM addressing.
2153 (symmetrical to CONFIG_I2C_X)
2157 Enables a software (bit-bang) SPI driver rather than
2158 using hardware support. This is a general purpose
2159 driver that only requires three general I/O port pins
2160 (two outputs, one input) to function. If this is
2161 defined, the board configuration must define several
2162 SPI configuration items (port pins to use, etc). For
2163 an example, see include/configs/sacsng.h.
2167 Enables a hardware SPI driver for general-purpose reads
2168 and writes. As with CONFIG_SOFT_SPI, the board configuration
2169 must define a list of chip-select function pointers.
2170 Currently supported on some MPC8xxx processors. For an
2171 example, see include/configs/mpc8349emds.h.
2175 Enables the driver for the SPI controllers on i.MX and MXC
2176 SoCs. Currently i.MX31/35/51 are supported.
2178 - FPGA Support: CONFIG_FPGA
2180 Enables FPGA subsystem.
2182 CONFIG_FPGA_<vendor>
2184 Enables support for specific chip vendors.
2187 CONFIG_FPGA_<family>
2189 Enables support for FPGA family.
2190 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX)
2194 Specify the number of FPGA devices to support.
2196 CONFIG_SYS_FPGA_PROG_FEEDBACK
2198 Enable printing of hash marks during FPGA configuration.
2200 CONFIG_SYS_FPGA_CHECK_BUSY
2202 Enable checks on FPGA configuration interface busy
2203 status by the configuration function. This option
2204 will require a board or device specific function to
2209 If defined, a function that provides delays in the FPGA
2210 configuration driver.
2212 CONFIG_SYS_FPGA_CHECK_CTRLC
2213 Allow Control-C to interrupt FPGA configuration
2215 CONFIG_SYS_FPGA_CHECK_ERROR
2217 Check for configuration errors during FPGA bitfile
2218 loading. For example, abort during Virtex II
2219 configuration if the INIT_B line goes low (which
2220 indicated a CRC error).
2222 CONFIG_SYS_FPGA_WAIT_INIT
2224 Maximum time to wait for the INIT_B line to deassert
2225 after PROB_B has been deasserted during a Virtex II
2226 FPGA configuration sequence. The default time is 500
2229 CONFIG_SYS_FPGA_WAIT_BUSY
2231 Maximum time to wait for BUSY to deassert during
2232 Virtex II FPGA configuration. The default is 5 ms.
2234 CONFIG_SYS_FPGA_WAIT_CONFIG
2236 Time to wait after FPGA configuration. The default is
2239 - Configuration Management:
2242 If defined, this string will be added to the U-Boot
2243 version information (U_BOOT_VERSION)
2245 - Vendor Parameter Protection:
2247 U-Boot considers the values of the environment
2248 variables "serial#" (Board Serial Number) and
2249 "ethaddr" (Ethernet Address) to be parameters that
2250 are set once by the board vendor / manufacturer, and
2251 protects these variables from casual modification by
2252 the user. Once set, these variables are read-only,
2253 and write or delete attempts are rejected. You can
2254 change this behaviour:
2256 If CONFIG_ENV_OVERWRITE is #defined in your config
2257 file, the write protection for vendor parameters is
2258 completely disabled. Anybody can change or delete
2261 Alternatively, if you #define _both_ CONFIG_ETHADDR
2262 _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
2263 Ethernet address is installed in the environment,
2264 which can be changed exactly ONCE by the user. [The
2265 serial# is unaffected by this, i. e. it remains
2268 The same can be accomplished in a more flexible way
2269 for any variable by configuring the type of access
2270 to allow for those variables in the ".flags" variable
2271 or define CONFIG_ENV_FLAGS_LIST_STATIC.
2276 Define this variable to enable the reservation of
2277 "protected RAM", i. e. RAM which is not overwritten
2278 by U-Boot. Define CONFIG_PRAM to hold the number of
2279 kB you want to reserve for pRAM. You can overwrite
2280 this default value by defining an environment
2281 variable "pram" to the number of kB you want to
2282 reserve. Note that the board info structure will
2283 still show the full amount of RAM. If pRAM is
2284 reserved, a new environment variable "mem" will
2285 automatically be defined to hold the amount of
2286 remaining RAM in a form that can be passed as boot
2287 argument to Linux, for instance like that:
2289 setenv bootargs ... mem=\${mem}
2292 This way you can tell Linux not to use this memory,
2293 either, which results in a memory region that will
2294 not be affected by reboots.
2296 *WARNING* If your board configuration uses automatic
2297 detection of the RAM size, you must make sure that
2298 this memory test is non-destructive. So far, the
2299 following board configurations are known to be
2302 IVMS8, IVML24, SPD8xx, TQM8xxL,
2303 HERMES, IP860, RPXlite, LWMON,
2306 - Access to physical memory region (> 4GB)
2307 Some basic support is provided for operations on memory not
2308 normally accessible to U-Boot - e.g. some architectures
2309 support access to more than 4GB of memory on 32-bit
2310 machines using physical address extension or similar.
2311 Define CONFIG_PHYSMEM to access this basic support, which
2312 currently only supports clearing the memory.
2317 Define this variable to stop the system in case of a
2318 fatal error, so that you have to reset it manually.
2319 This is probably NOT a good idea for an embedded
2320 system where you want the system to reboot
2321 automatically as fast as possible, but it may be
2322 useful during development since you can try to debug
2323 the conditions that lead to the situation.
2325 CONFIG_NET_RETRY_COUNT
2327 This variable defines the number of retries for
2328 network operations like ARP, RARP, TFTP, or BOOTP
2329 before giving up the operation. If not defined, a
2330 default value of 5 is used.
2334 Timeout waiting for an ARP reply in milliseconds.
2338 Timeout in milliseconds used in NFS protocol.
2339 If you encounter "ERROR: Cannot umount" in nfs command,
2340 try longer timeout such as
2341 #define CONFIG_NFS_TIMEOUT 10000UL
2343 - Command Interpreter:
2344 CONFIG_AUTO_COMPLETE
2346 Enable auto completion of commands using TAB.
2348 Note that this feature has NOT been implemented yet
2349 for the "hush" shell.
2352 CONFIG_SYS_HUSH_PARSER
2354 Define this variable to enable the "hush" shell (from
2355 Busybox) as command line interpreter, thus enabling
2356 powerful command line syntax like
2357 if...then...else...fi conditionals or `&&' and '||'
2358 constructs ("shell scripts").
2360 If undefined, you get the old, much simpler behaviour
2361 with a somewhat smaller memory footprint.
2364 CONFIG_SYS_PROMPT_HUSH_PS2
2366 This defines the secondary prompt string, which is
2367 printed when the command interpreter needs more input
2368 to complete a command. Usually "> ".
2372 In the current implementation, the local variables
2373 space and global environment variables space are
2374 separated. Local variables are those you define by
2375 simply typing `name=value'. To access a local
2376 variable later on, you have write `$name' or
2377 `${name}'; to execute the contents of a variable
2378 directly type `$name' at the command prompt.
2380 Global environment variables are those you use
2381 setenv/printenv to work with. To run a command stored
2382 in such a variable, you need to use the run command,
2383 and you must not use the '$' sign to access them.
2385 To store commands and special characters in a
2386 variable, please use double quotation marks
2387 surrounding the whole text of the variable, instead
2388 of the backslashes before semicolons and special
2391 - Commandline Editing and History:
2392 CONFIG_CMDLINE_EDITING
2394 Enable editing and History functions for interactive
2395 commandline input operations
2397 - Default Environment:
2398 CONFIG_EXTRA_ENV_SETTINGS
2400 Define this to contain any number of null terminated
2401 strings (variable = value pairs) that will be part of
2402 the default environment compiled into the boot image.
2404 For example, place something like this in your
2405 board's config file:
2407 #define CONFIG_EXTRA_ENV_SETTINGS \
2411 Warning: This method is based on knowledge about the
2412 internal format how the environment is stored by the
2413 U-Boot code. This is NOT an official, exported
2414 interface! Although it is unlikely that this format
2415 will change soon, there is no guarantee either.
2416 You better know what you are doing here.
2418 Note: overly (ab)use of the default environment is
2419 discouraged. Make sure to check other ways to preset
2420 the environment like the "source" command or the
2423 CONFIG_ENV_VARS_UBOOT_CONFIG
2425 Define this in order to add variables describing the
2426 U-Boot build configuration to the default environment.
2427 These will be named arch, cpu, board, vendor, and soc.
2429 Enabling this option will cause the following to be defined:
2437 CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG
2439 Define this in order to add variables describing certain
2440 run-time determined information about the hardware to the
2441 environment. These will be named board_name, board_rev.
2443 CONFIG_DELAY_ENVIRONMENT
2445 Normally the environment is loaded when the board is
2446 intialised so that it is available to U-Boot. This inhibits
2447 that so that the environment is not available until
2448 explicitly loaded later by U-Boot code. With CONFIG_OF_CONTROL
2449 this is instead controlled by the value of
2450 /config/load-environment.
2452 - DataFlash Support:
2453 CONFIG_HAS_DATAFLASH
2455 Defining this option enables DataFlash features and
2456 allows to read/write in Dataflash via the standard
2459 - Serial Flash support
2462 Defining this option enables SPI flash commands
2463 'sf probe/read/write/erase/update'.
2465 Usage requires an initial 'probe' to define the serial
2466 flash parameters, followed by read/write/erase/update
2469 The following defaults may be provided by the platform
2470 to handle the common case when only a single serial
2471 flash is present on the system.
2473 CONFIG_SF_DEFAULT_BUS Bus identifier
2474 CONFIG_SF_DEFAULT_CS Chip-select
2475 CONFIG_SF_DEFAULT_MODE (see include/spi.h)
2476 CONFIG_SF_DEFAULT_SPEED in Hz
2480 Define this option to include a destructive SPI flash
2483 - SystemACE Support:
2486 Adding this option adds support for Xilinx SystemACE
2487 chips attached via some sort of local bus. The address
2488 of the chip must also be defined in the
2489 CONFIG_SYS_SYSTEMACE_BASE macro. For example:
2491 #define CONFIG_SYSTEMACE
2492 #define CONFIG_SYS_SYSTEMACE_BASE 0xf0000000
2494 When SystemACE support is added, the "ace" device type
2495 becomes available to the fat commands, i.e. fatls.
2497 - TFTP Fixed UDP Port:
2500 If this is defined, the environment variable tftpsrcp
2501 is used to supply the TFTP UDP source port value.
2502 If tftpsrcp isn't defined, the normal pseudo-random port
2503 number generator is used.
2505 Also, the environment variable tftpdstp is used to supply
2506 the TFTP UDP destination port value. If tftpdstp isn't
2507 defined, the normal port 69 is used.
2509 The purpose for tftpsrcp is to allow a TFTP server to
2510 blindly start the TFTP transfer using the pre-configured
2511 target IP address and UDP port. This has the effect of
2512 "punching through" the (Windows XP) firewall, allowing
2513 the remainder of the TFTP transfer to proceed normally.
2514 A better solution is to properly configure the firewall,
2515 but sometimes that is not allowed.
2520 This enables a generic 'hash' command which can produce
2521 hashes / digests from a few algorithms (e.g. SHA1, SHA256).
2525 Enable the hash verify command (hash -v). This adds to code
2528 CONFIG_SHA1 - support SHA1 hashing
2529 CONFIG_SHA256 - support SHA256 hashing
2531 Note: There is also a sha1sum command, which should perhaps
2532 be deprecated in favour of 'hash sha1'.
2534 - Show boot progress:
2535 CONFIG_SHOW_BOOT_PROGRESS
2537 Defining this option allows to add some board-
2538 specific code (calling a user-provided function
2539 "show_boot_progress(int)") that enables you to show
2540 the system's boot progress on some display (for
2541 example, some LED's) on your board. At the moment,
2542 the following checkpoints are implemented:
2544 - Detailed boot stage timing
2546 Define this option to get detailed timing of each stage
2547 of the boot process.
2549 CONFIG_BOOTSTAGE_USER_COUNT
2550 This is the number of available user bootstage records.
2551 Each time you call bootstage_mark(BOOTSTAGE_ID_ALLOC, ...)
2552 a new ID will be allocated from this stash. If you exceed
2553 the limit, recording will stop.
2555 CONFIG_BOOTSTAGE_REPORT
2556 Define this to print a report before boot, similar to this:
2558 Timer summary in microseconds:
2561 3,575,678 3,575,678 board_init_f start
2562 3,575,695 17 arch_cpu_init A9
2563 3,575,777 82 arch_cpu_init done
2564 3,659,598 83,821 board_init_r start
2565 3,910,375 250,777 main_loop
2566 29,916,167 26,005,792 bootm_start
2567 30,361,327 445,160 start_kernel
2569 CONFIG_CMD_BOOTSTAGE
2570 Add a 'bootstage' command which supports printing a report
2571 and un/stashing of bootstage data.
2573 CONFIG_BOOTSTAGE_FDT
2574 Stash the bootstage information in the FDT. A root 'bootstage'
2575 node is created with each bootstage id as a child. Each child
2576 has a 'name' property and either 'mark' containing the
2577 mark time in microsecond, or 'accum' containing the
2578 accumulated time for that bootstage id in microseconds.
2583 name = "board_init_f";
2592 Code in the Linux kernel can find this in /proc/devicetree.
2594 Legacy uImage format:
2597 1 common/cmd_bootm.c before attempting to boot an image
2598 -1 common/cmd_bootm.c Image header has bad magic number
2599 2 common/cmd_bootm.c Image header has correct magic number
2600 -2 common/cmd_bootm.c Image header has bad checksum
2601 3 common/cmd_bootm.c Image header has correct checksum
2602 -3 common/cmd_bootm.c Image data has bad checksum
2603 4 common/cmd_bootm.c Image data has correct checksum
2604 -4 common/cmd_bootm.c Image is for unsupported architecture
2605 5 common/cmd_bootm.c Architecture check OK
2606 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi)
2607 6 common/cmd_bootm.c Image Type check OK
2608 -6 common/cmd_bootm.c gunzip uncompression error
2609 -7 common/cmd_bootm.c Unimplemented compression type
2610 7 common/cmd_bootm.c Uncompression OK
2611 8 common/cmd_bootm.c No uncompress/copy overwrite error
2612 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX)
2614 9 common/image.c Start initial ramdisk verification
2615 -10 common/image.c Ramdisk header has bad magic number
2616 -11 common/image.c Ramdisk header has bad checksum
2617 10 common/image.c Ramdisk header is OK
2618 -12 common/image.c Ramdisk data has bad checksum
2619 11 common/image.c Ramdisk data has correct checksum
2620 12 common/image.c Ramdisk verification complete, start loading
2621 -13 common/image.c Wrong Image Type (not PPC Linux ramdisk)
2622 13 common/image.c Start multifile image verification
2623 14 common/image.c No initial ramdisk, no multifile, continue.
2625 15 arch/<arch>/lib/bootm.c All preparation done, transferring control to OS
2627 -30 arch/powerpc/lib/board.c Fatal error, hang the system
2628 -31 post/post.c POST test failed, detected by post_output_backlog()
2629 -32 post/post.c POST test failed, detected by post_run_single()
2631 34 common/cmd_doc.c before loading a Image from a DOC device
2632 -35 common/cmd_doc.c Bad usage of "doc" command
2633 35 common/cmd_doc.c correct usage of "doc" command
2634 -36 common/cmd_doc.c No boot device
2635 36 common/cmd_doc.c correct boot device
2636 -37 common/cmd_doc.c Unknown Chip ID on boot device
2637 37 common/cmd_doc.c correct chip ID found, device available
2638 -38 common/cmd_doc.c Read Error on boot device
2639 38 common/cmd_doc.c reading Image header from DOC device OK
2640 -39 common/cmd_doc.c Image header has bad magic number
2641 39 common/cmd_doc.c Image header has correct magic number
2642 -40 common/cmd_doc.c Error reading Image from DOC device
2643 40 common/cmd_doc.c Image header has correct magic number
2644 41 common/cmd_ide.c before loading a Image from a IDE device
2645 -42 common/cmd_ide.c Bad usage of "ide" command
2646 42 common/cmd_ide.c correct usage of "ide" command
2647 -43 common/cmd_ide.c No boot device
2648 43 common/cmd_ide.c boot device found
2649 -44 common/cmd_ide.c Device not available
2650 44 common/cmd_ide.c Device available
2651 -45 common/cmd_ide.c wrong partition selected
2652 45 common/cmd_ide.c partition selected
2653 -46 common/cmd_ide.c Unknown partition table
2654 46 common/cmd_ide.c valid partition table found
2655 -47 common/cmd_ide.c Invalid partition type
2656 47 common/cmd_ide.c correct partition type
2657 -48 common/cmd_ide.c Error reading Image Header on boot device
2658 48 common/cmd_ide.c reading Image Header from IDE device OK
2659 -49 common/cmd_ide.c Image header has bad magic number
2660 49 common/cmd_ide.c Image header has correct magic number
2661 -50 common/cmd_ide.c Image header has bad checksum
2662 50 common/cmd_ide.c Image header has correct checksum
2663 -51 common/cmd_ide.c Error reading Image from IDE device
2664 51 common/cmd_ide.c reading Image from IDE device OK
2665 52 common/cmd_nand.c before loading a Image from a NAND device
2666 -53 common/cmd_nand.c Bad usage of "nand" command
2667 53 common/cmd_nand.c correct usage of "nand" command
2668 -54 common/cmd_nand.c No boot device
2669 54 common/cmd_nand.c boot device found
2670 -55 common/cmd_nand.c Unknown Chip ID on boot device
2671 55 common/cmd_nand.c correct chip ID found, device available
2672 -56 common/cmd_nand.c Error reading Image Header on boot device
2673 56 common/cmd_nand.c reading Image Header from NAND device OK
2674 -57 common/cmd_nand.c Image header has bad magic number
2675 57 common/cmd_nand.c Image header has correct magic number
2676 -58 common/cmd_nand.c Error reading Image from NAND device
2677 58 common/cmd_nand.c reading Image from NAND device OK
2679 -60 common/env_common.c Environment has a bad CRC, using default
2681 64 net/eth.c starting with Ethernet configuration.
2682 -64 net/eth.c no Ethernet found.
2683 65 net/eth.c Ethernet found.
2685 -80 common/cmd_net.c usage wrong
2686 80 common/cmd_net.c before calling NetLoop()
2687 -81 common/cmd_net.c some error in NetLoop() occurred
2688 81 common/cmd_net.c NetLoop() back without error
2689 -82 common/cmd_net.c size == 0 (File with size 0 loaded)
2690 82 common/cmd_net.c trying automatic boot
2691 83 common/cmd_net.c running "source" command
2692 -83 common/cmd_net.c some error in automatic boot or "source" command
2693 84 common/cmd_net.c end without errors
2698 100 common/cmd_bootm.c Kernel FIT Image has correct format
2699 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format
2700 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration
2701 -101 common/cmd_bootm.c Can't get configuration for kernel subimage
2702 102 common/cmd_bootm.c Kernel unit name specified
2703 -103 common/cmd_bootm.c Can't get kernel subimage node offset
2704 103 common/cmd_bootm.c Found configuration node
2705 104 common/cmd_bootm.c Got kernel subimage node offset
2706 -104 common/cmd_bootm.c Kernel subimage hash verification failed
2707 105 common/cmd_bootm.c Kernel subimage hash verification OK
2708 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture
2709 106 common/cmd_bootm.c Architecture check OK
2710 -106 common/cmd_bootm.c Kernel subimage has wrong type
2711 107 common/cmd_bootm.c Kernel subimage type OK
2712 -107 common/cmd_bootm.c Can't get kernel subimage data/size
2713 108 common/cmd_bootm.c Got kernel subimage data/size
2714 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT)
2715 -109 common/cmd_bootm.c Can't get kernel subimage type
2716 -110 common/cmd_bootm.c Can't get kernel subimage comp
2717 -111 common/cmd_bootm.c Can't get kernel subimage os
2718 -112 common/cmd_bootm.c Can't get kernel subimage load address
2719 -113 common/cmd_bootm.c Image uncompress/copy overwrite error
2721 120 common/image.c Start initial ramdisk verification
2722 -120 common/image.c Ramdisk FIT image has incorrect format
2723 121 common/image.c Ramdisk FIT image has correct format
2724 122 common/image.c No ramdisk subimage unit name, using configuration
2725 -122 common/image.c Can't get configuration for ramdisk subimage
2726 123 common/image.c Ramdisk unit name specified
2727 -124 common/image.c Can't get ramdisk subimage node offset
2728 125 common/image.c Got ramdisk subimage node offset
2729 -125 common/image.c Ramdisk subimage hash verification failed
2730 126 common/image.c Ramdisk subimage hash verification OK
2731 -126 common/image.c Ramdisk subimage for unsupported architecture
2732 127 common/image.c Architecture check OK
2733 -127 common/image.c Can't get ramdisk subimage data/size
2734 128 common/image.c Got ramdisk subimage data/size
2735 129 common/image.c Can't get ramdisk load address
2736 -129 common/image.c Got ramdisk load address
2738 -130 common/cmd_doc.c Incorrect FIT image format
2739 131 common/cmd_doc.c FIT image format OK
2741 -140 common/cmd_ide.c Incorrect FIT image format
2742 141 common/cmd_ide.c FIT image format OK
2744 -150 common/cmd_nand.c Incorrect FIT image format
2745 151 common/cmd_nand.c FIT image format OK
2747 - FIT image support:
2749 Enable support for the FIT uImage format.
2751 CONFIG_FIT_BEST_MATCH
2752 When no configuration is explicitly selected, default to the
2753 one whose fdt's compatibility field best matches that of
2754 U-Boot itself. A match is considered "best" if it matches the
2755 most specific compatibility entry of U-Boot's fdt's root node.
2756 The order of entries in the configuration's fdt is ignored.
2758 - Standalone program support:
2759 CONFIG_STANDALONE_LOAD_ADDR
2761 This option defines a board specific value for the
2762 address where standalone program gets loaded, thus
2763 overwriting the architecture dependent default
2766 - Frame Buffer Address:
2769 Define CONFIG_FB_ADDR if you want to use specific
2770 address for frame buffer. This is typically the case
2771 when using a graphics controller has separate video
2772 memory. U-Boot will then place the frame buffer at
2773 the given address instead of dynamically reserving it
2774 in system RAM by calling lcd_setmem(), which grabs
2775 the memory for the frame buffer depending on the
2776 configured panel size.
2778 Please see board_init_f function.
2780 - Automatic software updates via TFTP server
2782 CONFIG_UPDATE_TFTP_CNT_MAX
2783 CONFIG_UPDATE_TFTP_MSEC_MAX
2785 These options enable and control the auto-update feature;
2786 for a more detailed description refer to doc/README.update.
2788 - MTD Support (mtdparts command, UBI support)
2791 Adds the MTD device infrastructure from the Linux kernel.
2792 Needed for mtdparts command support.
2794 CONFIG_MTD_PARTITIONS
2796 Adds the MTD partitioning infrastructure from the Linux
2797 kernel. Needed for UBI support.
2801 Enable building of SPL globally.
2804 LDSCRIPT for linking the SPL binary.
2807 Maximum binary size (text, data and rodata) of the SPL binary.
2809 CONFIG_SPL_TEXT_BASE
2810 TEXT_BASE for linking the SPL binary.
2812 CONFIG_SPL_RELOC_TEXT_BASE
2813 Address to relocate to. If unspecified, this is equal to
2814 CONFIG_SPL_TEXT_BASE (i.e. no relocation is done).
2816 CONFIG_SPL_BSS_START_ADDR
2817 Link address for the BSS within the SPL binary.
2819 CONFIG_SPL_BSS_MAX_SIZE
2820 Maximum binary size of the BSS section of the SPL binary.
2823 Adress of the start of the stack SPL will use
2825 CONFIG_SPL_RELOC_STACK
2826 Adress of the start of the stack SPL will use after
2827 relocation. If unspecified, this is equal to
2830 CONFIG_SYS_SPL_MALLOC_START
2831 Starting address of the malloc pool used in SPL.
2833 CONFIG_SYS_SPL_MALLOC_SIZE
2834 The size of the malloc pool used in SPL.
2836 CONFIG_SPL_FRAMEWORK
2837 Enable the SPL framework under common/. This framework
2838 supports MMC, NAND and YMODEM loading of U-Boot and NAND
2839 NAND loading of the Linux Kernel.
2841 CONFIG_SPL_DISPLAY_PRINT
2842 For ARM, enable an optional function to print more information
2843 about the running system.
2845 CONFIG_SPL_INIT_MINIMAL
2846 Arch init code should be built for a very small image
2848 CONFIG_SPL_LIBCOMMON_SUPPORT
2849 Support for common/libcommon.o in SPL binary
2851 CONFIG_SPL_LIBDISK_SUPPORT
2852 Support for disk/libdisk.o in SPL binary
2854 CONFIG_SPL_I2C_SUPPORT
2855 Support for drivers/i2c/libi2c.o in SPL binary
2857 CONFIG_SPL_GPIO_SUPPORT
2858 Support for drivers/gpio/libgpio.o in SPL binary
2860 CONFIG_SPL_MMC_SUPPORT
2861 Support for drivers/mmc/libmmc.o in SPL binary
2863 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_SECTOR,
2864 CONFIG_SYS_U_BOOT_MAX_SIZE_SECTORS,
2865 CONFIG_SYS_MMC_SD_FAT_BOOT_PARTITION
2866 Address, size and partition on the MMC to load U-Boot from
2867 when the MMC is being used in raw mode.
2869 CONFIG_SPL_FAT_SUPPORT
2870 Support for fs/fat/libfat.o in SPL binary
2872 CONFIG_SPL_FAT_LOAD_PAYLOAD_NAME
2873 Filename to read to load U-Boot when reading from FAT
2875 CONFIG_SPL_MPC83XX_WAIT_FOR_NAND
2876 Set this for NAND SPL on PPC mpc83xx targets, so that
2877 start.S waits for the rest of the SPL to load before
2878 continuing (the hardware starts execution after just
2879 loading the first page rather than the full 4K).
2881 CONFIG_SPL_NAND_BASE
2882 Include nand_base.c in the SPL. Requires
2883 CONFIG_SPL_NAND_DRIVERS.
2885 CONFIG_SPL_NAND_DRIVERS
2886 SPL uses normal NAND drivers, not minimal drivers.
2889 Include standard software ECC in the SPL
2891 CONFIG_SPL_NAND_SIMPLE
2892 Support for NAND boot using simple NAND drivers that
2893 expose the cmd_ctrl() interface.
2895 CONFIG_SYS_NAND_5_ADDR_CYCLE, CONFIG_SYS_NAND_PAGE_COUNT,
2896 CONFIG_SYS_NAND_PAGE_SIZE, CONFIG_SYS_NAND_OOBSIZE,
2897 CONFIG_SYS_NAND_BLOCK_SIZE, CONFIG_SYS_NAND_BAD_BLOCK_POS,
2898 CONFIG_SYS_NAND_ECCPOS, CONFIG_SYS_NAND_ECCSIZE,
2899 CONFIG_SYS_NAND_ECCBYTES
2900 Defines the size and behavior of the NAND that SPL uses
2903 CONFIG_SYS_NAND_U_BOOT_OFFS
2904 Location in NAND to read U-Boot from
2906 CONFIG_SYS_NAND_U_BOOT_DST
2907 Location in memory to load U-Boot to
2909 CONFIG_SYS_NAND_U_BOOT_SIZE
2910 Size of image to load
2912 CONFIG_SYS_NAND_U_BOOT_START
2913 Entry point in loaded image to jump to
2915 CONFIG_SYS_NAND_HW_ECC_OOBFIRST
2916 Define this if you need to first read the OOB and then the
2917 data. This is used for example on davinci plattforms.
2919 CONFIG_SPL_OMAP3_ID_NAND
2920 Support for an OMAP3-specific set of functions to return the
2921 ID and MFR of the first attached NAND chip, if present.
2923 CONFIG_SPL_SERIAL_SUPPORT
2924 Support for drivers/serial/libserial.o in SPL binary
2926 CONFIG_SPL_SPI_FLASH_SUPPORT
2927 Support for drivers/mtd/spi/libspi_flash.o in SPL binary
2929 CONFIG_SPL_SPI_SUPPORT
2930 Support for drivers/spi/libspi.o in SPL binary
2932 CONFIG_SPL_RAM_DEVICE
2933 Support for running image already present in ram, in SPL binary
2935 CONFIG_SPL_LIBGENERIC_SUPPORT
2936 Support for lib/libgeneric.o in SPL binary
2939 Linker address to which the SPL should be padded before
2940 appending the SPL payload.
2943 Final target image containing SPL and payload. Some SPLs
2944 use an arch-specific makefile fragment instead, for
2945 example if more than one image needs to be produced.
2950 [so far only for SMDK2400 boards]
2952 - Modem support enable:
2953 CONFIG_MODEM_SUPPORT
2955 - RTS/CTS Flow control enable:
2958 - Modem debug support:
2959 CONFIG_MODEM_SUPPORT_DEBUG
2961 Enables debugging stuff (char screen[1024], dbg())
2962 for modem support. Useful only with BDI2000.
2964 - Interrupt support (PPC):
2966 There are common interrupt_init() and timer_interrupt()
2967 for all PPC archs. interrupt_init() calls interrupt_init_cpu()
2968 for CPU specific initialization. interrupt_init_cpu()
2969 should set decrementer_count to appropriate value. If
2970 CPU resets decrementer automatically after interrupt
2971 (ppc4xx) it should set decrementer_count to zero.
2972 timer_interrupt() calls timer_interrupt_cpu() for CPU
2973 specific handling. If board has watchdog / status_led
2974 / other_activity_monitor it works automatically from
2975 general timer_interrupt().
2979 In the target system modem support is enabled when a
2980 specific key (key combination) is pressed during
2981 power-on. Otherwise U-Boot will boot normally
2982 (autoboot). The key_pressed() function is called from
2983 board_init(). Currently key_pressed() is a dummy
2984 function, returning 1 and thus enabling modem
2987 If there are no modem init strings in the
2988 environment, U-Boot proceed to autoboot; the
2989 previous output (banner, info printfs) will be
2992 See also: doc/README.Modem
2994 Board initialization settings:
2995 ------------------------------
2997 During Initialization u-boot calls a number of board specific functions
2998 to allow the preparation of board specific prerequisites, e.g. pin setup
2999 before drivers are initialized. To enable these callbacks the
3000 following configuration macros have to be defined. Currently this is
3001 architecture specific, so please check arch/your_architecture/lib/board.c
3002 typically in board_init_f() and board_init_r().
3004 - CONFIG_BOARD_EARLY_INIT_F: Call board_early_init_f()
3005 - CONFIG_BOARD_EARLY_INIT_R: Call board_early_init_r()
3006 - CONFIG_BOARD_LATE_INIT: Call board_late_init()
3007 - CONFIG_BOARD_POSTCLK_INIT: Call board_postclk_init()
3009 Configuration Settings:
3010 -----------------------
3012 - CONFIG_SYS_LONGHELP: Defined when you want long help messages included;
3013 undefine this when you're short of memory.
3015 - CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default
3016 width of the commands listed in the 'help' command output.
3018 - CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to
3019 prompt for user input.
3021 - CONFIG_SYS_CBSIZE: Buffer size for input from the Console
3023 - CONFIG_SYS_PBSIZE: Buffer size for Console output
3025 - CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands
3027 - CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to
3028 the application (usually a Linux kernel) when it is
3031 - CONFIG_SYS_BAUDRATE_TABLE:
3032 List of legal baudrate settings for this board.
3034 - CONFIG_SYS_CONSOLE_INFO_QUIET
3035 Suppress display of console information at boot.
3037 - CONFIG_SYS_CONSOLE_IS_IN_ENV
3038 If the board specific function
3039 extern int overwrite_console (void);
3040 returns 1, the stdin, stderr and stdout are switched to the
3041 serial port, else the settings in the environment are used.
3043 - CONFIG_SYS_CONSOLE_OVERWRITE_ROUTINE
3044 Enable the call to overwrite_console().
3046 - CONFIG_SYS_CONSOLE_ENV_OVERWRITE
3047 Enable overwrite of previous console environment settings.
3049 - CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END:
3050 Begin and End addresses of the area used by the
3053 - CONFIG_SYS_ALT_MEMTEST:
3054 Enable an alternate, more extensive memory test.
3056 - CONFIG_SYS_MEMTEST_SCRATCH:
3057 Scratch address used by the alternate memory test
3058 You only need to set this if address zero isn't writeable
3060 - CONFIG_SYS_MEM_TOP_HIDE (PPC only):
3061 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header,
3062 this specified memory area will get subtracted from the top
3063 (end) of RAM and won't get "touched" at all by U-Boot. By
3064 fixing up gd->ram_size the Linux kernel should gets passed
3065 the now "corrected" memory size and won't touch it either.
3066 This should work for arch/ppc and arch/powerpc. Only Linux
3067 board ports in arch/powerpc with bootwrapper support that
3068 recalculate the memory size from the SDRAM controller setup
3069 will have to get fixed in Linux additionally.
3071 This option can be used as a workaround for the 440EPx/GRx
3072 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't
3075 WARNING: Please make sure that this value is a multiple of
3076 the Linux page size (normally 4k). If this is not the case,
3077 then the end address of the Linux memory will be located at a
3078 non page size aligned address and this could cause major
3081 - CONFIG_SYS_LOADS_BAUD_CHANGE:
3082 Enable temporary baudrate change while serial download
3084 - CONFIG_SYS_SDRAM_BASE:
3085 Physical start address of SDRAM. _Must_ be 0 here.
3087 - CONFIG_SYS_MBIO_BASE:
3088 Physical start address of Motherboard I/O (if using a
3091 - CONFIG_SYS_FLASH_BASE:
3092 Physical start address of Flash memory.
3094 - CONFIG_SYS_MONITOR_BASE:
3095 Physical start address of boot monitor code (set by
3096 make config files to be same as the text base address
3097 (CONFIG_SYS_TEXT_BASE) used when linking) - same as
3098 CONFIG_SYS_FLASH_BASE when booting from flash.
3100 - CONFIG_SYS_MONITOR_LEN:
3101 Size of memory reserved for monitor code, used to
3102 determine _at_compile_time_ (!) if the environment is
3103 embedded within the U-Boot image, or in a separate
3106 - CONFIG_SYS_MALLOC_LEN:
3107 Size of DRAM reserved for malloc() use.
3109 - CONFIG_SYS_BOOTM_LEN:
3110 Normally compressed uImages are limited to an
3111 uncompressed size of 8 MBytes. If this is not enough,
3112 you can define CONFIG_SYS_BOOTM_LEN in your board config file
3113 to adjust this setting to your needs.
3115 - CONFIG_SYS_BOOTMAPSZ:
3116 Maximum size of memory mapped by the startup code of
3117 the Linux kernel; all data that must be processed by
3118 the Linux kernel (bd_info, boot arguments, FDT blob if
3119 used) must be put below this limit, unless "bootm_low"
3120 enviroment variable is defined and non-zero. In such case
3121 all data for the Linux kernel must be between "bootm_low"
3122 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ. The environment
3123 variable "bootm_mapsize" will override the value of
3124 CONFIG_SYS_BOOTMAPSZ. If CONFIG_SYS_BOOTMAPSZ is undefined,
3125 then the value in "bootm_size" will be used instead.
3127 - CONFIG_SYS_BOOT_RAMDISK_HIGH:
3128 Enable initrd_high functionality. If defined then the
3129 initrd_high feature is enabled and the bootm ramdisk subcommand
3132 - CONFIG_SYS_BOOT_GET_CMDLINE:
3133 Enables allocating and saving kernel cmdline in space between
3134 "bootm_low" and "bootm_low" + BOOTMAPSZ.
3136 - CONFIG_SYS_BOOT_GET_KBD:
3137 Enables allocating and saving a kernel copy of the bd_info in
3138 space between "bootm_low" and "bootm_low" + BOOTMAPSZ.
3140 - CONFIG_SYS_MAX_FLASH_BANKS:
3141 Max number of Flash memory banks
3143 - CONFIG_SYS_MAX_FLASH_SECT:
3144 Max number of sectors on a Flash chip
3146 - CONFIG_SYS_FLASH_ERASE_TOUT:
3147 Timeout for Flash erase operations (in ms)
3149 - CONFIG_SYS_FLASH_WRITE_TOUT:
3150 Timeout for Flash write operations (in ms)
3152 - CONFIG_SYS_FLASH_LOCK_TOUT
3153 Timeout for Flash set sector lock bit operation (in ms)
3155 - CONFIG_SYS_FLASH_UNLOCK_TOUT
3156 Timeout for Flash clear lock bits operation (in ms)
3158 - CONFIG_SYS_FLASH_PROTECTION
3159 If defined, hardware flash sectors protection is used
3160 instead of U-Boot software protection.
3162 - CONFIG_SYS_DIRECT_FLASH_TFTP:
3164 Enable TFTP transfers directly to flash memory;
3165 without this option such a download has to be
3166 performed in two steps: (1) download to RAM, and (2)
3167 copy from RAM to flash.
3169 The two-step approach is usually more reliable, since
3170 you can check if the download worked before you erase
3171 the flash, but in some situations (when system RAM is
3172 too limited to allow for a temporary copy of the
3173 downloaded image) this option may be very useful.
3175 - CONFIG_SYS_FLASH_CFI:
3176 Define if the flash driver uses extra elements in the
3177 common flash structure for storing flash geometry.
3179 - CONFIG_FLASH_CFI_DRIVER
3180 This option also enables the building of the cfi_flash driver
3181 in the drivers directory
3183 - CONFIG_FLASH_CFI_MTD
3184 This option enables the building of the cfi_mtd driver
3185 in the drivers directory. The driver exports CFI flash
3188 - CONFIG_SYS_FLASH_USE_BUFFER_WRITE
3189 Use buffered writes to flash.
3191 - CONFIG_FLASH_SPANSION_S29WS_N
3192 s29ws-n MirrorBit flash has non-standard addresses for buffered
3195 - CONFIG_SYS_FLASH_QUIET_TEST
3196 If this option is defined, the common CFI flash doesn't
3197 print it's warning upon not recognized FLASH banks. This
3198 is useful, if some of the configured banks are only
3199 optionally available.
3201 - CONFIG_FLASH_SHOW_PROGRESS
3202 If defined (must be an integer), print out countdown
3203 digits and dots. Recommended value: 45 (9..1) for 80
3204 column displays, 15 (3..1) for 40 column displays.
3206 - CONFIG_SYS_RX_ETH_BUFFER:
3207 Defines the number of Ethernet receive buffers. On some
3208 Ethernet controllers it is recommended to set this value
3209 to 8 or even higher (EEPRO100 or 405 EMAC), since all
3210 buffers can be full shortly after enabling the interface
3211 on high Ethernet traffic.
3212 Defaults to 4 if not defined.
3214 - CONFIG_ENV_MAX_ENTRIES
3216 Maximum number of entries in the hash table that is used
3217 internally to store the environment settings. The default
3218 setting is supposed to be generous and should work in most
3219 cases. This setting can be used to tune behaviour; see
3220 lib/hashtable.c for details.
3222 - CONFIG_ENV_FLAGS_LIST_DEFAULT
3223 - CONFIG_ENV_FLAGS_LIST_STATIC
3224 Enable validation of the values given to enviroment variables when
3225 calling env set. Variables can be restricted to only decimal,
3226 hexadecimal, or boolean. If CONFIG_CMD_NET is also defined,
3227 the variables can also be restricted to IP address or MAC address.
3229 The format of the list is:
3230 type_attribute = [s|d|x|b|i|m]
3231 access_atribute = [a|r|o|c]
3232 attributes = type_attribute[access_atribute]
3233 entry = variable_name[:attributes]
3236 The type attributes are:
3237 s - String (default)
3240 b - Boolean ([1yYtT|0nNfF])
3244 The access attributes are:
3250 - CONFIG_ENV_FLAGS_LIST_DEFAULT
3251 Define this to a list (string) to define the ".flags"
3252 envirnoment variable in the default or embedded environment.
3254 - CONFIG_ENV_FLAGS_LIST_STATIC
3255 Define this to a list (string) to define validation that
3256 should be done if an entry is not found in the ".flags"
3257 environment variable. To override a setting in the static
3258 list, simply add an entry for the same variable name to the
3261 - CONFIG_ENV_ACCESS_IGNORE_FORCE
3262 If defined, don't allow the -f switch to env set override variable
3265 - CONFIG_SYS_GENERIC_BOARD
3266 This selects the architecture-generic board system instead of the
3267 architecture-specific board files. It is intended to move boards
3268 to this new framework over time. Defining this will disable the
3269 arch/foo/lib/board.c file and use common/board_f.c and
3270 common/board_r.c instead. To use this option your architecture
3271 must support it (i.e. must define __HAVE_ARCH_GENERIC_BOARD in
3272 its config.mk file). If you find problems enabling this option on
3273 your board please report the problem and send patches!
3275 - CONFIG_SYS_SYM_OFFSETS
3276 This is set by architectures that use offsets for link symbols
3277 instead of absolute values. So bss_start is obtained using an
3278 offset _bss_start_ofs from CONFIG_SYS_TEXT_BASE, rather than
3279 directly. You should not need to touch this setting.
3282 The following definitions that deal with the placement and management
3283 of environment data (variable area); in general, we support the
3284 following configurations:
3286 - CONFIG_BUILD_ENVCRC:
3288 Builds up envcrc with the target environment so that external utils
3289 may easily extract it and embed it in final U-Boot images.
3291 - CONFIG_ENV_IS_IN_FLASH:
3293 Define this if the environment is in flash memory.
3295 a) The environment occupies one whole flash sector, which is
3296 "embedded" in the text segment with the U-Boot code. This
3297 happens usually with "bottom boot sector" or "top boot
3298 sector" type flash chips, which have several smaller
3299 sectors at the start or the end. For instance, such a
3300 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In
3301 such a case you would place the environment in one of the
3302 4 kB sectors - with U-Boot code before and after it. With
3303 "top boot sector" type flash chips, you would put the
3304 environment in one of the last sectors, leaving a gap
3305 between U-Boot and the environment.
3307 - CONFIG_ENV_OFFSET:
3309 Offset of environment data (variable area) to the
3310 beginning of flash memory; for instance, with bottom boot
3311 type flash chips the second sector can be used: the offset
3312 for this sector is given here.
3314 CONFIG_ENV_OFFSET is used relative to CONFIG_SYS_FLASH_BASE.
3318 This is just another way to specify the start address of
3319 the flash sector containing the environment (instead of
3322 - CONFIG_ENV_SECT_SIZE:
3324 Size of the sector containing the environment.
3327 b) Sometimes flash chips have few, equal sized, BIG sectors.
3328 In such a case you don't want to spend a whole sector for
3333 If you use this in combination with CONFIG_ENV_IS_IN_FLASH
3334 and CONFIG_ENV_SECT_SIZE, you can specify to use only a part
3335 of this flash sector for the environment. This saves
3336 memory for the RAM copy of the environment.
3338 It may also save flash memory if you decide to use this
3339 when your environment is "embedded" within U-Boot code,
3340 since then the remainder of the flash sector could be used
3341 for U-Boot code. It should be pointed out that this is
3342 STRONGLY DISCOURAGED from a robustness point of view:
3343 updating the environment in flash makes it always
3344 necessary to erase the WHOLE sector. If something goes
3345 wrong before the contents has been restored from a copy in
3346 RAM, your target system will be dead.
3348 - CONFIG_ENV_ADDR_REDUND
3349 CONFIG_ENV_SIZE_REDUND
3351 These settings describe a second storage area used to hold
3352 a redundant copy of the environment data, so that there is
3353 a valid backup copy in case there is a power failure during
3354 a "saveenv" operation.
3356 BE CAREFUL! Any changes to the flash layout, and some changes to the
3357 source code will make it necessary to adapt <board>/u-boot.lds*
3361 - CONFIG_ENV_IS_IN_NVRAM:
3363 Define this if you have some non-volatile memory device
3364 (NVRAM, battery buffered SRAM) which you want to use for the
3370 These two #defines are used to determine the memory area you
3371 want to use for environment. It is assumed that this memory
3372 can just be read and written to, without any special
3375 BE CAREFUL! The first access to the environment happens quite early
3376 in U-Boot initalization (when we try to get the setting of for the
3377 console baudrate). You *MUST* have mapped your NVRAM area then, or
3380 Please note that even with NVRAM we still use a copy of the
3381 environment in RAM: we could work on NVRAM directly, but we want to
3382 keep settings there always unmodified except somebody uses "saveenv"
3383 to save the current settings.
3386 - CONFIG_ENV_IS_IN_EEPROM:
3388 Use this if you have an EEPROM or similar serial access
3389 device and a driver for it.
3391 - CONFIG_ENV_OFFSET:
3394 These two #defines specify the offset and size of the
3395 environment area within the total memory of your EEPROM.
3397 - CONFIG_SYS_I2C_EEPROM_ADDR:
3398 If defined, specified the chip address of the EEPROM device.
3399 The default address is zero.
3401 - CONFIG_SYS_EEPROM_PAGE_WRITE_BITS:
3402 If defined, the number of bits used to address bytes in a
3403 single page in the EEPROM device. A 64 byte page, for example
3404 would require six bits.
3406 - CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS:
3407 If defined, the number of milliseconds to delay between
3408 page writes. The default is zero milliseconds.
3410 - CONFIG_SYS_I2C_EEPROM_ADDR_LEN:
3411 The length in bytes of the EEPROM memory array address. Note
3412 that this is NOT the chip address length!
3414 - CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW:
3415 EEPROM chips that implement "address overflow" are ones
3416 like Catalyst 24WC04/08/16 which has 9/10/11 bits of
3417 address and the extra bits end up in the "chip address" bit
3418 slots. This makes a 24WC08 (1Kbyte) chip look like four 256
3421 Note that we consider the length of the address field to
3422 still be one byte because the extra address bits are hidden
3423 in the chip address.
3425 - CONFIG_SYS_EEPROM_SIZE:
3426 The size in bytes of the EEPROM device.
3428 - CONFIG_ENV_EEPROM_IS_ON_I2C
3429 define this, if you have I2C and SPI activated, and your
3430 EEPROM, which holds the environment, is on the I2C bus.
3432 - CONFIG_I2C_ENV_EEPROM_BUS
3433 if you have an Environment on an EEPROM reached over
3434 I2C muxes, you can define here, how to reach this
3435 EEPROM. For example:
3437 #define CONFIG_I2C_ENV_EEPROM_BUS "pca9547:70:d\0"
3439 EEPROM which holds the environment, is reached over
3440 a pca9547 i2c mux with address 0x70, channel 3.
3442 - CONFIG_ENV_IS_IN_DATAFLASH:
3444 Define this if you have a DataFlash memory device which you
3445 want to use for the environment.
3447 - CONFIG_ENV_OFFSET:
3451 These three #defines specify the offset and size of the
3452 environment area within the total memory of your DataFlash placed
3453 at the specified address.
3455 - CONFIG_ENV_IS_IN_REMOTE:
3457 Define this if you have a remote memory space which you
3458 want to use for the local device's environment.
3463 These two #defines specify the address and size of the
3464 environment area within the remote memory space. The
3465 local device can get the environment from remote memory
3466 space by SRIO or PCIE links.
3468 BE CAREFUL! For some special cases, the local device can not use
3469 "saveenv" command. For example, the local device will get the
3470 environment stored in a remote NOR flash by SRIO or PCIE link,
3471 but it can not erase, write this NOR flash by SRIO or PCIE interface.
3473 - CONFIG_ENV_IS_IN_NAND:
3475 Define this if you have a NAND device which you want to use
3476 for the environment.
3478 - CONFIG_ENV_OFFSET:
3481 These two #defines specify the offset and size of the environment
3482 area within the first NAND device. CONFIG_ENV_OFFSET must be
3483 aligned to an erase block boundary.
3485 - CONFIG_ENV_OFFSET_REDUND (optional):
3487 This setting describes a second storage area of CONFIG_ENV_SIZE
3488 size used to hold a redundant copy of the environment data, so
3489 that there is a valid backup copy in case there is a power failure
3490 during a "saveenv" operation. CONFIG_ENV_OFFSET_RENDUND must be
3491 aligned to an erase block boundary.
3493 - CONFIG_ENV_RANGE (optional):
3495 Specifies the length of the region in which the environment
3496 can be written. This should be a multiple of the NAND device's
3497 block size. Specifying a range with more erase blocks than
3498 are needed to hold CONFIG_ENV_SIZE allows bad blocks within
3499 the range to be avoided.
3501 - CONFIG_ENV_OFFSET_OOB (optional):
3503 Enables support for dynamically retrieving the offset of the
3504 environment from block zero's out-of-band data. The
3505 "nand env.oob" command can be used to record this offset.
3506 Currently, CONFIG_ENV_OFFSET_REDUND is not supported when
3507 using CONFIG_ENV_OFFSET_OOB.
3509 - CONFIG_NAND_ENV_DST
3511 Defines address in RAM to which the nand_spl code should copy the
3512 environment. If redundant environment is used, it will be copied to
3513 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE.
3515 - CONFIG_SYS_SPI_INIT_OFFSET
3517 Defines offset to the initial SPI buffer area in DPRAM. The
3518 area is used at an early stage (ROM part) if the environment
3519 is configured to reside in the SPI EEPROM: We need a 520 byte
3520 scratch DPRAM area. It is used between the two initialization
3521 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems
3522 to be a good choice since it makes it far enough from the
3523 start of the data area as well as from the stack pointer.
3525 Please note that the environment is read-only until the monitor
3526 has been relocated to RAM and a RAM copy of the environment has been
3527 created; also, when using EEPROM you will have to use getenv_f()
3528 until then to read environment variables.
3530 The environment is protected by a CRC32 checksum. Before the monitor
3531 is relocated into RAM, as a result of a bad CRC you will be working
3532 with the compiled-in default environment - *silently*!!! [This is
3533 necessary, because the first environment variable we need is the
3534 "baudrate" setting for the console - if we have a bad CRC, we don't
3535 have any device yet where we could complain.]
3537 Note: once the monitor has been relocated, then it will complain if
3538 the default environment is used; a new CRC is computed as soon as you
3539 use the "saveenv" command to store a valid environment.
3541 - CONFIG_SYS_FAULT_ECHO_LINK_DOWN:
3542 Echo the inverted Ethernet link state to the fault LED.
3544 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR
3545 also needs to be defined.
3547 - CONFIG_SYS_FAULT_MII_ADDR:
3548 MII address of the PHY to check for the Ethernet link state.
3550 - CONFIG_NS16550_MIN_FUNCTIONS:
3551 Define this if you desire to only have use of the NS16550_init
3552 and NS16550_putc functions for the serial driver located at
3553 drivers/serial/ns16550.c. This option is useful for saving
3554 space for already greatly restricted images, including but not
3555 limited to NAND_SPL configurations.
3557 - CONFIG_DISPLAY_BOARDINFO
3558 Display information about the board that U-Boot is running on
3559 when U-Boot starts up. The board function checkboard() is called
3562 - CONFIG_DISPLAY_BOARDINFO_LATE
3563 Similar to the previous option, but display this information
3564 later, once stdio is running and output goes to the LCD, if
3567 Low Level (hardware related) configuration options:
3568 ---------------------------------------------------
3570 - CONFIG_SYS_CACHELINE_SIZE:
3571 Cache Line Size of the CPU.
3573 - CONFIG_SYS_DEFAULT_IMMR:
3574 Default address of the IMMR after system reset.
3576 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU,
3577 and RPXsuper) to be able to adjust the position of
3578 the IMMR register after a reset.
3580 - CONFIG_SYS_CCSRBAR_DEFAULT:
3581 Default (power-on reset) physical address of CCSR on Freescale
3584 - CONFIG_SYS_CCSRBAR:
3585 Virtual address of CCSR. On a 32-bit build, this is typically
3586 the same value as CONFIG_SYS_CCSRBAR_DEFAULT.
3588 CONFIG_SYS_DEFAULT_IMMR must also be set to this value,
3589 for cross-platform code that uses that macro instead.
3591 - CONFIG_SYS_CCSRBAR_PHYS:
3592 Physical address of CCSR. CCSR can be relocated to a new
3593 physical address, if desired. In this case, this macro should
3594 be set to that address. Otherwise, it should be set to the
3595 same value as CONFIG_SYS_CCSRBAR_DEFAULT. For example, CCSR
3596 is typically relocated on 36-bit builds. It is recommended
3597 that this macro be defined via the _HIGH and _LOW macros:
3599 #define CONFIG_SYS_CCSRBAR_PHYS ((CONFIG_SYS_CCSRBAR_PHYS_HIGH
3600 * 1ull) << 32 | CONFIG_SYS_CCSRBAR_PHYS_LOW)
3602 - CONFIG_SYS_CCSRBAR_PHYS_HIGH:
3603 Bits 33-36 of CONFIG_SYS_CCSRBAR_PHYS. This value is typically
3604 either 0 (32-bit build) or 0xF (36-bit build). This macro is
3605 used in assembly code, so it must not contain typecasts or
3606 integer size suffixes (e.g. "ULL").
3608 - CONFIG_SYS_CCSRBAR_PHYS_LOW:
3609 Lower 32-bits of CONFIG_SYS_CCSRBAR_PHYS. This macro is
3610 used in assembly code, so it must not contain typecasts or
3611 integer size suffixes (e.g. "ULL").
3613 - CONFIG_SYS_CCSR_DO_NOT_RELOCATE:
3614 If this macro is defined, then CONFIG_SYS_CCSRBAR_PHYS will be
3615 forced to a value that ensures that CCSR is not relocated.
3617 - Floppy Disk Support:
3618 CONFIG_SYS_FDC_DRIVE_NUMBER
3620 the default drive number (default value 0)
3622 CONFIG_SYS_ISA_IO_STRIDE
3624 defines the spacing between FDC chipset registers
3627 CONFIG_SYS_ISA_IO_OFFSET
3629 defines the offset of register from address. It
3630 depends on which part of the data bus is connected to
3631 the FDC chipset. (default value 0)
3633 If CONFIG_SYS_ISA_IO_STRIDE CONFIG_SYS_ISA_IO_OFFSET and
3634 CONFIG_SYS_FDC_DRIVE_NUMBER are undefined, they take their
3637 if CONFIG_SYS_FDC_HW_INIT is defined, then the function
3638 fdc_hw_init() is called at the beginning of the FDC
3639 setup. fdc_hw_init() must be provided by the board
3640 source code. It is used to make hardware dependant
3644 Most IDE controllers were designed to be connected with PCI
3645 interface. Only few of them were designed for AHB interface.
3646 When software is doing ATA command and data transfer to
3647 IDE devices through IDE-AHB controller, some additional
3648 registers accessing to these kind of IDE-AHB controller
3651 - CONFIG_SYS_IMMR: Physical address of the Internal Memory.
3652 DO NOT CHANGE unless you know exactly what you're
3653 doing! (11-4) [MPC8xx/82xx systems only]
3655 - CONFIG_SYS_INIT_RAM_ADDR:
3657 Start address of memory area that can be used for
3658 initial data and stack; please note that this must be
3659 writable memory that is working WITHOUT special
3660 initialization, i. e. you CANNOT use normal RAM which
3661 will become available only after programming the
3662 memory controller and running certain initialization
3665 U-Boot uses the following memory types:
3666 - MPC8xx and MPC8260: IMMR (internal memory of the CPU)
3667 - MPC824X: data cache
3668 - PPC4xx: data cache
3670 - CONFIG_SYS_GBL_DATA_OFFSET:
3672 Offset of the initial data structure in the memory
3673 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually
3674 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial
3675 data is located at the end of the available space
3676 (sometimes written as (CONFIG_SYS_INIT_RAM_SIZE -
3677 CONFIG_SYS_INIT_DATA_SIZE), and the initial stack is just
3678 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR +
3679 CONFIG_SYS_GBL_DATA_OFFSET) downward.
3682 On the MPC824X (or other systems that use the data
3683 cache for initial memory) the address chosen for
3684 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must
3685 point to an otherwise UNUSED address space between
3686 the top of RAM and the start of the PCI space.
3688 - CONFIG_SYS_SIUMCR: SIU Module Configuration (11-6)
3690 - CONFIG_SYS_SYPCR: System Protection Control (11-9)
3692 - CONFIG_SYS_TBSCR: Time Base Status and Control (11-26)
3694 - CONFIG_SYS_PISCR: Periodic Interrupt Status and Control (11-31)
3696 - CONFIG_SYS_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30)
3698 - CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27)
3700 - CONFIG_SYS_OR_TIMING_SDRAM:
3703 - CONFIG_SYS_MAMR_PTA:
3704 periodic timer for refresh
3706 - CONFIG_SYS_DER: Debug Event Register (37-47)
3708 - FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM,
3709 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP,
3710 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM,
3711 CONFIG_SYS_BR1_PRELIM:
3712 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
3714 - SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
3715 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM,
3716 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM:
3717 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
3719 - CONFIG_SYS_MAMR_PTA, CONFIG_SYS_MPTPR_2BK_4K, CONFIG_SYS_MPTPR_1BK_4K, CONFIG_SYS_MPTPR_2BK_8K,
3720 CONFIG_SYS_MPTPR_1BK_8K, CONFIG_SYS_MAMR_8COL, CONFIG_SYS_MAMR_9COL:
3721 Machine Mode Register and Memory Periodic Timer
3722 Prescaler definitions (SDRAM timing)
3724 - CONFIG_SYS_I2C_UCODE_PATCH, CONFIG_SYS_I2C_DPMEM_OFFSET [0x1FC0]:
3725 enable I2C microcode relocation patch (MPC8xx);
3726 define relocation offset in DPRAM [DSP2]
3728 - CONFIG_SYS_SMC_UCODE_PATCH, CONFIG_SYS_SMC_DPMEM_OFFSET [0x1FC0]:
3729 enable SMC microcode relocation patch (MPC8xx);
3730 define relocation offset in DPRAM [SMC1]
3732 - CONFIG_SYS_SPI_UCODE_PATCH, CONFIG_SYS_SPI_DPMEM_OFFSET [0x1FC0]:
3733 enable SPI microcode relocation patch (MPC8xx);
3734 define relocation offset in DPRAM [SCC4]
3736 - CONFIG_SYS_USE_OSCCLK:
3737 Use OSCM clock mode on MBX8xx board. Be careful,
3738 wrong setting might damage your board. Read
3739 doc/README.MBX before setting this variable!
3741 - CONFIG_SYS_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only)
3742 Offset of the bootmode word in DPRAM used by post
3743 (Power On Self Tests). This definition overrides
3744 #define'd default value in commproc.h resp.
3747 - CONFIG_SYS_PCI_SLV_MEM_LOCAL, CONFIG_SYS_PCI_SLV_MEM_BUS, CONFIG_SYS_PICMR0_MASK_ATTRIB,
3748 CONFIG_SYS_PCI_MSTR0_LOCAL, CONFIG_SYS_PCIMSK0_MASK, CONFIG_SYS_PCI_MSTR1_LOCAL,
3749 CONFIG_SYS_PCIMSK1_MASK, CONFIG_SYS_PCI_MSTR_MEM_LOCAL, CONFIG_SYS_PCI_MSTR_MEM_BUS,
3750 CONFIG_SYS_CPU_PCI_MEM_START, CONFIG_SYS_PCI_MSTR_MEM_SIZE, CONFIG_SYS_POCMR0_MASK_ATTRIB,
3751 CONFIG_SYS_PCI_MSTR_MEMIO_LOCAL, CONFIG_SYS_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START,
3752 CONFIG_SYS_PCI_MSTR_MEMIO_SIZE, CONFIG_SYS_POCMR1_MASK_ATTRIB, CONFIG_SYS_PCI_MSTR_IO_LOCAL,
3753 CONFIG_SYS_PCI_MSTR_IO_BUS, CONFIG_SYS_CPU_PCI_IO_START, CONFIG_SYS_PCI_MSTR_IO_SIZE,
3754 CONFIG_SYS_POCMR2_MASK_ATTRIB: (MPC826x only)
3755 Overrides the default PCI memory map in arch/powerpc/cpu/mpc8260/pci.c if set.
3757 - CONFIG_PCI_DISABLE_PCIE:
3758 Disable PCI-Express on systems where it is supported but not
3761 - CONFIG_PCI_ENUM_ONLY
3762 Only scan through and get the devices on the busses.
3763 Don't do any setup work, presumably because someone or
3764 something has already done it, and we don't need to do it
3765 a second time. Useful for platforms that are pre-booted
3766 by coreboot or similar.
3769 Chip has SRIO or not
3772 Board has SRIO 1 port available
3775 Board has SRIO 2 port available
3777 - CONFIG_SYS_SRIOn_MEM_VIRT:
3778 Virtual Address of SRIO port 'n' memory region
3780 - CONFIG_SYS_SRIOn_MEM_PHYS:
3781 Physical Address of SRIO port 'n' memory region
3783 - CONFIG_SYS_SRIOn_MEM_SIZE:
3784 Size of SRIO port 'n' memory region
3786 - CONFIG_SYS_NDFC_16
3787 Defined to tell the NDFC that the NAND chip is using a
3790 - CONFIG_SYS_NDFC_EBC0_CFG
3791 Sets the EBC0_CFG register for the NDFC. If not defined
3792 a default value will be used.
3795 Get DDR timing information from an I2C EEPROM. Common
3796 with pluggable memory modules such as SODIMMs
3799 I2C address of the SPD EEPROM
3801 - CONFIG_SYS_SPD_BUS_NUM
3802 If SPD EEPROM is on an I2C bus other than the first
3803 one, specify here. Note that the value must resolve
3804 to something your driver can deal with.
3806 - CONFIG_SYS_DDR_RAW_TIMING
3807 Get DDR timing information from other than SPD. Common with
3808 soldered DDR chips onboard without SPD. DDR raw timing
3809 parameters are extracted from datasheet and hard-coded into
3810 header files or board specific files.
3812 - CONFIG_FSL_DDR_INTERACTIVE
3813 Enable interactive DDR debugging. See doc/README.fsl-ddr.
3815 - CONFIG_SYS_83XX_DDR_USES_CS0
3816 Only for 83xx systems. If specified, then DDR should
3817 be configured using CS0 and CS1 instead of CS2 and CS3.
3819 - CONFIG_ETHER_ON_FEC[12]
3820 Define to enable FEC[12] on a 8xx series processor.
3822 - CONFIG_FEC[12]_PHY
3823 Define to the hardcoded PHY address which corresponds
3824 to the given FEC; i. e.
3825 #define CONFIG_FEC1_PHY 4
3826 means that the PHY with address 4 is connected to FEC1
3828 When set to -1, means to probe for first available.
3830 - CONFIG_FEC[12]_PHY_NORXERR
3831 The PHY does not have a RXERR line (RMII only).
3832 (so program the FEC to ignore it).
3835 Enable RMII mode for all FECs.
3836 Note that this is a global option, we can't
3837 have one FEC in standard MII mode and another in RMII mode.
3839 - CONFIG_CRC32_VERIFY
3840 Add a verify option to the crc32 command.
3843 => crc32 -v <address> <count> <crc32>
3845 Where address/count indicate a memory area
3846 and crc32 is the correct crc32 which the
3850 Add the "loopw" memory command. This only takes effect if
3851 the memory commands are activated globally (CONFIG_CMD_MEM).
3854 Add the "mdc" and "mwc" memory commands. These are cyclic
3859 This command will print 4 bytes (10,11,12,13) each 500 ms.
3861 => mwc.l 100 12345678 10
3862 This command will write 12345678 to address 100 all 10 ms.
3864 This only takes effect if the memory commands are activated
3865 globally (CONFIG_CMD_MEM).
3867 - CONFIG_SKIP_LOWLEVEL_INIT
3868 [ARM, NDS32, MIPS only] If this variable is defined, then certain
3869 low level initializations (like setting up the memory
3870 controller) are omitted and/or U-Boot does not
3871 relocate itself into RAM.
3873 Normally this variable MUST NOT be defined. The only
3874 exception is when U-Boot is loaded (to RAM) by some
3875 other boot loader or by a debugger which performs
3876 these initializations itself.
3879 Modifies the behaviour of start.S when compiling a loader
3880 that is executed before the actual U-Boot. E.g. when
3881 compiling a NAND SPL.
3883 - CONFIG_ARCH_MAP_SYSMEM
3884 Generally U-Boot (and in particular the md command) uses
3885 effective address. It is therefore not necessary to regard
3886 U-Boot address as virtual addresses that need to be translated
3887 to physical addresses. However, sandbox requires this, since
3888 it maintains its own little RAM buffer which contains all
3889 addressable memory. This option causes some memory accesses
3890 to be mapped through map_sysmem() / unmap_sysmem().
3892 - CONFIG_USE_ARCH_MEMCPY
3893 CONFIG_USE_ARCH_MEMSET
3894 If these options are used a optimized version of memcpy/memset will
3895 be used if available. These functions may be faster under some
3896 conditions but may increase the binary size.
3898 - CONFIG_X86_RESET_VECTOR
3899 If defined, the x86 reset vector code is included. This is not
3900 needed when U-Boot is running from Coreboot.
3903 Defines the MPU clock speed (in MHz).
3905 NOTE : currently only supported on AM335x platforms.
3907 Freescale QE/FMAN Firmware Support:
3908 -----------------------------------
3910 The Freescale QUICCEngine (QE) and Frame Manager (FMAN) both support the
3911 loading of "firmware", which is encoded in the QE firmware binary format.
3912 This firmware often needs to be loaded during U-Boot booting, so macros
3913 are used to identify the storage device (NOR flash, SPI, etc) and the address
3916 - CONFIG_SYS_QE_FMAN_FW_ADDR
3917 The address in the storage device where the firmware is located. The
3918 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
3921 - CONFIG_SYS_QE_FMAN_FW_LENGTH
3922 The maximum possible size of the firmware. The firmware binary format
3923 has a field that specifies the actual size of the firmware, but it
3924 might not be possible to read any part of the firmware unless some
3925 local storage is allocated to hold the entire firmware first.
3927 - CONFIG_SYS_QE_FMAN_FW_IN_NOR
3928 Specifies that QE/FMAN firmware is located in NOR flash, mapped as
3929 normal addressable memory via the LBC. CONFIG_SYS_FMAN_FW_ADDR is the
3930 virtual address in NOR flash.
3932 - CONFIG_SYS_QE_FMAN_FW_IN_NAND
3933 Specifies that QE/FMAN firmware is located in NAND flash.
3934 CONFIG_SYS_FMAN_FW_ADDR is the offset within NAND flash.
3936 - CONFIG_SYS_QE_FMAN_FW_IN_MMC
3937 Specifies that QE/FMAN firmware is located on the primary SD/MMC
3938 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
3940 - CONFIG_SYS_QE_FMAN_FW_IN_SPIFLASH
3941 Specifies that QE/FMAN firmware is located on the primary SPI
3942 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
3944 - CONFIG_SYS_QE_FMAN_FW_IN_REMOTE
3945 Specifies that QE/FMAN firmware is located in the remote (master)
3946 memory space. CONFIG_SYS_FMAN_FW_ADDR is a virtual address which
3947 can be mapped from slave TLB->slave LAW->slave SRIO or PCIE outbound
3948 window->master inbound window->master LAW->the ucode address in
3949 master's memory space.
3951 Building the Software:
3952 ======================
3954 Building U-Boot has been tested in several native build environments
3955 and in many different cross environments. Of course we cannot support
3956 all possibly existing versions of cross development tools in all
3957 (potentially obsolete) versions. In case of tool chain problems we
3958 recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK)
3959 which is extensively used to build and test U-Boot.
3961 If you are not using a native environment, it is assumed that you
3962 have GNU cross compiling tools available in your path. In this case,
3963 you must set the environment variable CROSS_COMPILE in your shell.
3964 Note that no changes to the Makefile or any other source files are
3965 necessary. For example using the ELDK on a 4xx CPU, please enter:
3967 $ CROSS_COMPILE=ppc_4xx-
3968 $ export CROSS_COMPILE
3970 Note: If you wish to generate Windows versions of the utilities in
3971 the tools directory you can use the MinGW toolchain
3972 (http://www.mingw.org). Set your HOST tools to the MinGW
3973 toolchain and execute 'make tools'. For example:
3975 $ make HOSTCC=i586-mingw32msvc-gcc HOSTSTRIP=i586-mingw32msvc-strip tools
3977 Binaries such as tools/mkimage.exe will be created which can
3978 be executed on computers running Windows.
3980 U-Boot is intended to be simple to build. After installing the
3981 sources you must configure U-Boot for one specific board type. This
3986 where "NAME_config" is the name of one of the existing configu-
3987 rations; see boards.cfg for supported names.
3989 Note: for some board special configuration names may exist; check if
3990 additional information is available from the board vendor; for
3991 instance, the TQM823L systems are available without (standard)
3992 or with LCD support. You can select such additional "features"
3993 when choosing the configuration, i. e.
3996 - will configure for a plain TQM823L, i. e. no LCD support
3998 make TQM823L_LCD_config
3999 - will configure for a TQM823L with U-Boot console on LCD
4004 Finally, type "make all", and you should get some working U-Boot
4005 images ready for download to / installation on your system:
4007 - "u-boot.bin" is a raw binary image
4008 - "u-boot" is an image in ELF binary format
4009 - "u-boot.srec" is in Motorola S-Record format
4011 By default the build is performed locally and the objects are saved
4012 in the source directory. One of the two methods can be used to change
4013 this behavior and build U-Boot to some external directory:
4015 1. Add O= to the make command line invocations:
4017 make O=/tmp/build distclean
4018 make O=/tmp/build NAME_config
4019 make O=/tmp/build all
4021 2. Set environment variable BUILD_DIR to point to the desired location:
4023 export BUILD_DIR=/tmp/build
4028 Note that the command line "O=" setting overrides the BUILD_DIR environment
4032 Please be aware that the Makefiles assume you are using GNU make, so
4033 for instance on NetBSD you might need to use "gmake" instead of
4037 If the system board that you have is not listed, then you will need
4038 to port U-Boot to your hardware platform. To do this, follow these
4041 1. Add a new configuration option for your board to the toplevel
4042 "boards.cfg" file, using the existing entries as examples.
4043 Follow the instructions there to keep the boards in order.
4044 2. Create a new directory to hold your board specific code. Add any
4045 files you need. In your board directory, you will need at least
4046 the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds".
4047 3. Create a new configuration file "include/configs/<board>.h" for
4049 3. If you're porting U-Boot to a new CPU, then also create a new
4050 directory to hold your CPU specific code. Add any files you need.
4051 4. Run "make <board>_config" with your new name.
4052 5. Type "make", and you should get a working "u-boot.srec" file
4053 to be installed on your target system.
4054 6. Debug and solve any problems that might arise.
4055 [Of course, this last step is much harder than it sounds.]
4058 Testing of U-Boot Modifications, Ports to New Hardware, etc.:
4059 ==============================================================
4061 If you have modified U-Boot sources (for instance added a new board
4062 or support for new devices, a new CPU, etc.) you are expected to
4063 provide feedback to the other developers. The feedback normally takes
4064 the form of a "patch", i. e. a context diff against a certain (latest
4065 official or latest in the git repository) version of U-Boot sources.
4067 But before you submit such a patch, please verify that your modifi-
4068 cation did not break existing code. At least make sure that *ALL* of
4069 the supported boards compile WITHOUT ANY compiler warnings. To do so,
4070 just run the "MAKEALL" script, which will configure and build U-Boot
4071 for ALL supported system. Be warned, this will take a while. You can
4072 select which (cross) compiler to use by passing a `CROSS_COMPILE'
4073 environment variable to the script, i. e. to use the ELDK cross tools
4076 CROSS_COMPILE=ppc_8xx- MAKEALL
4078 or to build on a native PowerPC system you can type
4080 CROSS_COMPILE=' ' MAKEALL
4082 When using the MAKEALL script, the default behaviour is to build
4083 U-Boot in the source directory. This location can be changed by
4084 setting the BUILD_DIR environment variable. Also, for each target
4085 built, the MAKEALL script saves two log files (<target>.ERR and
4086 <target>.MAKEALL) in the <source dir>/LOG directory. This default
4087 location can be changed by setting the MAKEALL_LOGDIR environment
4088 variable. For example:
4090 export BUILD_DIR=/tmp/build
4091 export MAKEALL_LOGDIR=/tmp/log
4092 CROSS_COMPILE=ppc_8xx- MAKEALL
4094 With the above settings build objects are saved in the /tmp/build,
4095 log files are saved in the /tmp/log and the source tree remains clean
4096 during the whole build process.
4099 See also "U-Boot Porting Guide" below.
4102 Monitor Commands - Overview:
4103 ============================
4105 go - start application at address 'addr'
4106 run - run commands in an environment variable
4107 bootm - boot application image from memory
4108 bootp - boot image via network using BootP/TFTP protocol
4109 bootz - boot zImage from memory
4110 tftpboot- boot image via network using TFTP protocol
4111 and env variables "ipaddr" and "serverip"
4112 (and eventually "gatewayip")
4113 tftpput - upload a file via network using TFTP protocol
4114 rarpboot- boot image via network using RARP/TFTP protocol
4115 diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
4116 loads - load S-Record file over serial line
4117 loadb - load binary file over serial line (kermit mode)
4119 mm - memory modify (auto-incrementing)
4120 nm - memory modify (constant address)
4121 mw - memory write (fill)
4123 cmp - memory compare
4124 crc32 - checksum calculation
4125 i2c - I2C sub-system
4126 sspi - SPI utility commands
4127 base - print or set address offset
4128 printenv- print environment variables
4129 setenv - set environment variables
4130 saveenv - save environment variables to persistent storage
4131 protect - enable or disable FLASH write protection
4132 erase - erase FLASH memory
4133 flinfo - print FLASH memory information
4134 nand - NAND memory operations (see doc/README.nand)
4135 bdinfo - print Board Info structure
4136 iminfo - print header information for application image
4137 coninfo - print console devices and informations
4138 ide - IDE sub-system
4139 loop - infinite loop on address range
4140 loopw - infinite write loop on address range
4141 mtest - simple RAM test
4142 icache - enable or disable instruction cache
4143 dcache - enable or disable data cache
4144 reset - Perform RESET of the CPU
4145 echo - echo args to console
4146 version - print monitor version
4147 help - print online help
4148 ? - alias for 'help'
4151 Monitor Commands - Detailed Description:
4152 ========================================
4156 For now: just type "help <command>".
4159 Environment Variables:
4160 ======================
4162 U-Boot supports user configuration using Environment Variables which
4163 can be made persistent by saving to Flash memory.
4165 Environment Variables are set using "setenv", printed using
4166 "printenv", and saved to Flash using "saveenv". Using "setenv"
4167 without a value can be used to delete a variable from the
4168 environment. As long as you don't save the environment you are
4169 working with an in-memory copy. In case the Flash area containing the
4170 environment is erased by accident, a default environment is provided.
4172 Some configuration options can be set using Environment Variables.
4174 List of environment variables (most likely not complete):
4176 baudrate - see CONFIG_BAUDRATE
4178 bootdelay - see CONFIG_BOOTDELAY
4180 bootcmd - see CONFIG_BOOTCOMMAND
4182 bootargs - Boot arguments when booting an RTOS image
4184 bootfile - Name of the image to load with TFTP
4186 bootm_low - Memory range available for image processing in the bootm
4187 command can be restricted. This variable is given as
4188 a hexadecimal number and defines lowest address allowed
4189 for use by the bootm command. See also "bootm_size"
4190 environment variable. Address defined by "bootm_low" is
4191 also the base of the initial memory mapping for the Linux
4192 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ and
4195 bootm_mapsize - Size of the initial memory mapping for the Linux kernel.
4196 This variable is given as a hexadecimal number and it
4197 defines the size of the memory region starting at base
4198 address bootm_low that is accessible by the Linux kernel
4199 during early boot. If unset, CONFIG_SYS_BOOTMAPSZ is used
4200 as the default value if it is defined, and bootm_size is
4203 bootm_size - Memory range available for image processing in the bootm
4204 command can be restricted. This variable is given as
4205 a hexadecimal number and defines the size of the region
4206 allowed for use by the bootm command. See also "bootm_low"
4207 environment variable.
4209 updatefile - Location of the software update file on a TFTP server, used
4210 by the automatic software update feature. Please refer to
4211 documentation in doc/README.update for more details.
4213 autoload - if set to "no" (any string beginning with 'n'),
4214 "bootp" will just load perform a lookup of the
4215 configuration from the BOOTP server, but not try to
4216 load any image using TFTP
4218 autostart - if set to "yes", an image loaded using the "bootp",
4219 "rarpboot", "tftpboot" or "diskboot" commands will
4220 be automatically started (by internally calling
4223 If set to "no", a standalone image passed to the
4224 "bootm" command will be copied to the load address
4225 (and eventually uncompressed), but NOT be started.
4226 This can be used to load and uncompress arbitrary
4229 fdt_high - if set this restricts the maximum address that the
4230 flattened device tree will be copied into upon boot.
4231 For example, if you have a system with 1 GB memory
4232 at physical address 0x10000000, while Linux kernel
4233 only recognizes the first 704 MB as low memory, you
4234 may need to set fdt_high as 0x3C000000 to have the
4235 device tree blob be copied to the maximum address
4236 of the 704 MB low memory, so that Linux kernel can
4237 access it during the boot procedure.
4239 If this is set to the special value 0xFFFFFFFF then
4240 the fdt will not be copied at all on boot. For this
4241 to work it must reside in writable memory, have
4242 sufficient padding on the end of it for u-boot to
4243 add the information it needs into it, and the memory
4244 must be accessible by the kernel.
4246 fdtcontroladdr- if set this is the address of the control flattened
4247 device tree used by U-Boot when CONFIG_OF_CONTROL is
4250 i2cfast - (PPC405GP|PPC405EP only)
4251 if set to 'y' configures Linux I2C driver for fast
4252 mode (400kHZ). This environment variable is used in
4253 initialization code. So, for changes to be effective
4254 it must be saved and board must be reset.
4256 initrd_high - restrict positioning of initrd images:
4257 If this variable is not set, initrd images will be
4258 copied to the highest possible address in RAM; this
4259 is usually what you want since it allows for
4260 maximum initrd size. If for some reason you want to
4261 make sure that the initrd image is loaded below the
4262 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment
4263 variable to a value of "no" or "off" or "0".
4264 Alternatively, you can set it to a maximum upper
4265 address to use (U-Boot will still check that it
4266 does not overwrite the U-Boot stack and data).
4268 For instance, when you have a system with 16 MB
4269 RAM, and want to reserve 4 MB from use by Linux,
4270 you can do this by adding "mem=12M" to the value of
4271 the "bootargs" variable. However, now you must make
4272 sure that the initrd image is placed in the first
4273 12 MB as well - this can be done with
4275 setenv initrd_high 00c00000
4277 If you set initrd_high to 0xFFFFFFFF, this is an
4278 indication to U-Boot that all addresses are legal
4279 for the Linux kernel, including addresses in flash
4280 memory. In this case U-Boot will NOT COPY the
4281 ramdisk at all. This may be useful to reduce the
4282 boot time on your system, but requires that this
4283 feature is supported by your Linux kernel.
4285 ipaddr - IP address; needed for tftpboot command
4287 loadaddr - Default load address for commands like "bootp",
4288 "rarpboot", "tftpboot", "loadb" or "diskboot"
4290 loads_echo - see CONFIG_LOADS_ECHO
4292 serverip - TFTP server IP address; needed for tftpboot command
4294 bootretry - see CONFIG_BOOT_RETRY_TIME
4296 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
4298 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
4300 ethprime - controls which interface is used first.
4302 ethact - controls which interface is currently active.
4303 For example you can do the following
4305 => setenv ethact FEC
4306 => ping 192.168.0.1 # traffic sent on FEC
4307 => setenv ethact SCC
4308 => ping 10.0.0.1 # traffic sent on SCC
4310 ethrotate - When set to "no" U-Boot does not go through all
4311 available network interfaces.
4312 It just stays at the currently selected interface.
4314 netretry - When set to "no" each network operation will
4315 either succeed or fail without retrying.
4316 When set to "once" the network operation will
4317 fail when all the available network interfaces
4318 are tried once without success.
4319 Useful on scripts which control the retry operation
4322 npe_ucode - set load address for the NPE microcode
4324 tftpsrcport - If this is set, the value is used for TFTP's
4327 tftpdstport - If this is set, the value is used for TFTP's UDP
4328 destination port instead of the Well Know Port 69.
4330 tftpblocksize - Block size to use for TFTP transfers; if not set,
4331 we use the TFTP server's default block size
4333 tftptimeout - Retransmission timeout for TFTP packets (in milli-
4334 seconds, minimum value is 1000 = 1 second). Defines
4335 when a packet is considered to be lost so it has to
4336 be retransmitted. The default is 5000 = 5 seconds.
4337 Lowering this value may make downloads succeed
4338 faster in networks with high packet loss rates or
4339 with unreliable TFTP servers.
4341 vlan - When set to a value < 4095 the traffic over
4342 Ethernet is encapsulated/received over 802.1q
4345 The following image location variables contain the location of images
4346 used in booting. The "Image" column gives the role of the image and is
4347 not an environment variable name. The other columns are environment
4348 variable names. "File Name" gives the name of the file on a TFTP
4349 server, "RAM Address" gives the location in RAM the image will be
4350 loaded to, and "Flash Location" gives the image's address in NOR
4351 flash or offset in NAND flash.
4353 *Note* - these variables don't have to be defined for all boards, some
4354 boards currenlty use other variables for these purposes, and some
4355 boards use these variables for other purposes.
4357 Image File Name RAM Address Flash Location
4358 ----- --------- ----------- --------------
4359 u-boot u-boot u-boot_addr_r u-boot_addr
4360 Linux kernel bootfile kernel_addr_r kernel_addr
4361 device tree blob fdtfile fdt_addr_r fdt_addr
4362 ramdisk ramdiskfile ramdisk_addr_r ramdisk_addr
4364 The following environment variables may be used and automatically
4365 updated by the network boot commands ("bootp" and "rarpboot"),
4366 depending the information provided by your boot server:
4368 bootfile - see above
4369 dnsip - IP address of your Domain Name Server
4370 dnsip2 - IP address of your secondary Domain Name Server
4371 gatewayip - IP address of the Gateway (Router) to use
4372 hostname - Target hostname
4374 netmask - Subnet Mask
4375 rootpath - Pathname of the root filesystem on the NFS server
4376 serverip - see above
4379 There are two special Environment Variables:
4381 serial# - contains hardware identification information such
4382 as type string and/or serial number
4383 ethaddr - Ethernet address
4385 These variables can be set only once (usually during manufacturing of
4386 the board). U-Boot refuses to delete or overwrite these variables
4387 once they have been set once.
4390 Further special Environment Variables:
4392 ver - Contains the U-Boot version string as printed
4393 with the "version" command. This variable is
4394 readonly (see CONFIG_VERSION_VARIABLE).
4397 Please note that changes to some configuration parameters may take
4398 only effect after the next boot (yes, that's just like Windoze :-).
4401 Callback functions for environment variables:
4402 ---------------------------------------------
4404 For some environment variables, the behavior of u-boot needs to change
4405 when their values are changed. This functionailty allows functions to
4406 be associated with arbitrary variables. On creation, overwrite, or
4407 deletion, the callback will provide the opportunity for some side
4408 effect to happen or for the change to be rejected.
4410 The callbacks are named and associated with a function using the
4411 U_BOOT_ENV_CALLBACK macro in your board or driver code.
4413 These callbacks are associated with variables in one of two ways. The
4414 static list can be added to by defining CONFIG_ENV_CALLBACK_LIST_STATIC
4415 in the board configuration to a string that defines a list of
4416 associations. The list must be in the following format:
4418 entry = variable_name[:callback_name]
4421 If the callback name is not specified, then the callback is deleted.
4422 Spaces are also allowed anywhere in the list.
4424 Callbacks can also be associated by defining the ".callbacks" variable
4425 with the same list format above. Any association in ".callbacks" will
4426 override any association in the static list. You can define
4427 CONFIG_ENV_CALLBACK_LIST_DEFAULT to a list (string) to define the
4428 ".callbacks" envirnoment variable in the default or embedded environment.
4431 Command Line Parsing:
4432 =====================
4434 There are two different command line parsers available with U-Boot:
4435 the old "simple" one, and the much more powerful "hush" shell:
4437 Old, simple command line parser:
4438 --------------------------------
4440 - supports environment variables (through setenv / saveenv commands)
4441 - several commands on one line, separated by ';'
4442 - variable substitution using "... ${name} ..." syntax
4443 - special characters ('$', ';') can be escaped by prefixing with '\',
4445 setenv bootcmd bootm \${address}
4446 - You can also escape text by enclosing in single apostrophes, for example:
4447 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
4452 - similar to Bourne shell, with control structures like
4453 if...then...else...fi, for...do...done; while...do...done,
4454 until...do...done, ...
4455 - supports environment ("global") variables (through setenv / saveenv
4456 commands) and local shell variables (through standard shell syntax
4457 "name=value"); only environment variables can be used with "run"
4463 (1) If a command line (or an environment variable executed by a "run"
4464 command) contains several commands separated by semicolon, and
4465 one of these commands fails, then the remaining commands will be
4468 (2) If you execute several variables with one call to run (i. e.
4469 calling run with a list of variables as arguments), any failing
4470 command will cause "run" to terminate, i. e. the remaining
4471 variables are not executed.
4473 Note for Redundant Ethernet Interfaces:
4474 =======================================
4476 Some boards come with redundant Ethernet interfaces; U-Boot supports
4477 such configurations and is capable of automatic selection of a
4478 "working" interface when needed. MAC assignment works as follows:
4480 Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
4481 MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
4482 "eth1addr" (=>eth1), "eth2addr", ...
4484 If the network interface stores some valid MAC address (for instance
4485 in SROM), this is used as default address if there is NO correspon-
4486 ding setting in the environment; if the corresponding environment
4487 variable is set, this overrides the settings in the card; that means:
4489 o If the SROM has a valid MAC address, and there is no address in the
4490 environment, the SROM's address is used.
4492 o If there is no valid address in the SROM, and a definition in the
4493 environment exists, then the value from the environment variable is
4496 o If both the SROM and the environment contain a MAC address, and
4497 both addresses are the same, this MAC address is used.
4499 o If both the SROM and the environment contain a MAC address, and the
4500 addresses differ, the value from the environment is used and a
4503 o If neither SROM nor the environment contain a MAC address, an error
4506 If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses
4507 will be programmed into hardware as part of the initialization process. This
4508 may be skipped by setting the appropriate 'ethmacskip' environment variable.
4509 The naming convention is as follows:
4510 "ethmacskip" (=>eth0), "eth1macskip" (=>eth1) etc.
4515 U-Boot is capable of booting (and performing other auxiliary operations on)
4516 images in two formats:
4518 New uImage format (FIT)
4519 -----------------------
4521 Flexible and powerful format based on Flattened Image Tree -- FIT (similar
4522 to Flattened Device Tree). It allows the use of images with multiple
4523 components (several kernels, ramdisks, etc.), with contents protected by
4524 SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory.
4530 Old image format is based on binary files which can be basically anything,
4531 preceded by a special header; see the definitions in include/image.h for
4532 details; basically, the header defines the following image properties:
4534 * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
4535 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
4536 LynxOS, pSOS, QNX, RTEMS, INTEGRITY;
4537 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS,
4539 * Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86,
4540 IA64, MIPS, NDS32, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
4541 Currently supported: ARM, AVR32, Intel x86, MIPS, NDS32, Nios II, PowerPC).
4542 * Compression Type (uncompressed, gzip, bzip2)
4548 The header is marked by a special Magic Number, and both the header
4549 and the data portions of the image are secured against corruption by
4556 Although U-Boot should support any OS or standalone application
4557 easily, the main focus has always been on Linux during the design of
4560 U-Boot includes many features that so far have been part of some
4561 special "boot loader" code within the Linux kernel. Also, any
4562 "initrd" images to be used are no longer part of one big Linux image;
4563 instead, kernel and "initrd" are separate images. This implementation
4564 serves several purposes:
4566 - the same features can be used for other OS or standalone
4567 applications (for instance: using compressed images to reduce the
4568 Flash memory footprint)
4570 - it becomes much easier to port new Linux kernel versions because
4571 lots of low-level, hardware dependent stuff are done by U-Boot
4573 - the same Linux kernel image can now be used with different "initrd"
4574 images; of course this also means that different kernel images can
4575 be run with the same "initrd". This makes testing easier (you don't
4576 have to build a new "zImage.initrd" Linux image when you just
4577 change a file in your "initrd"). Also, a field-upgrade of the
4578 software is easier now.
4584 Porting Linux to U-Boot based systems:
4585 ---------------------------------------
4587 U-Boot cannot save you from doing all the necessary modifications to
4588 configure the Linux device drivers for use with your target hardware
4589 (no, we don't intend to provide a full virtual machine interface to
4592 But now you can ignore ALL boot loader code (in arch/powerpc/mbxboot).
4594 Just make sure your machine specific header file (for instance
4595 include/asm-ppc/tqm8xx.h) includes the same definition of the Board
4596 Information structure as we define in include/asm-<arch>/u-boot.h,
4597 and make sure that your definition of IMAP_ADDR uses the same value
4598 as your U-Boot configuration in CONFIG_SYS_IMMR.
4601 Configuring the Linux kernel:
4602 -----------------------------
4604 No specific requirements for U-Boot. Make sure you have some root
4605 device (initial ramdisk, NFS) for your target system.
4608 Building a Linux Image:
4609 -----------------------
4611 With U-Boot, "normal" build targets like "zImage" or "bzImage" are
4612 not used. If you use recent kernel source, a new build target
4613 "uImage" will exist which automatically builds an image usable by
4614 U-Boot. Most older kernels also have support for a "pImage" target,
4615 which was introduced for our predecessor project PPCBoot and uses a
4616 100% compatible format.
4625 The "uImage" build target uses a special tool (in 'tools/mkimage') to
4626 encapsulate a compressed Linux kernel image with header information,
4627 CRC32 checksum etc. for use with U-Boot. This is what we are doing:
4629 * build a standard "vmlinux" kernel image (in ELF binary format):
4631 * convert the kernel into a raw binary image:
4633 ${CROSS_COMPILE}-objcopy -O binary \
4634 -R .note -R .comment \
4635 -S vmlinux linux.bin
4637 * compress the binary image:
4641 * package compressed binary image for U-Boot:
4643 mkimage -A ppc -O linux -T kernel -C gzip \
4644 -a 0 -e 0 -n "Linux Kernel Image" \
4645 -d linux.bin.gz uImage
4648 The "mkimage" tool can also be used to create ramdisk images for use
4649 with U-Boot, either separated from the Linux kernel image, or
4650 combined into one file. "mkimage" encapsulates the images with a 64
4651 byte header containing information about target architecture,
4652 operating system, image type, compression method, entry points, time
4653 stamp, CRC32 checksums, etc.
4655 "mkimage" can be called in two ways: to verify existing images and
4656 print the header information, or to build new images.
4658 In the first form (with "-l" option) mkimage lists the information
4659 contained in the header of an existing U-Boot image; this includes
4660 checksum verification:
4662 tools/mkimage -l image
4663 -l ==> list image header information
4665 The second form (with "-d" option) is used to build a U-Boot image
4666 from a "data file" which is used as image payload:
4668 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
4669 -n name -d data_file image
4670 -A ==> set architecture to 'arch'
4671 -O ==> set operating system to 'os'
4672 -T ==> set image type to 'type'
4673 -C ==> set compression type 'comp'
4674 -a ==> set load address to 'addr' (hex)
4675 -e ==> set entry point to 'ep' (hex)
4676 -n ==> set image name to 'name'
4677 -d ==> use image data from 'datafile'
4679 Right now, all Linux kernels for PowerPC systems use the same load
4680 address (0x00000000), but the entry point address depends on the
4683 - 2.2.x kernels have the entry point at 0x0000000C,
4684 - 2.3.x and later kernels have the entry point at 0x00000000.
4686 So a typical call to build a U-Boot image would read:
4688 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
4689 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
4690 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz \
4691 > examples/uImage.TQM850L
4692 Image Name: 2.4.4 kernel for TQM850L
4693 Created: Wed Jul 19 02:34:59 2000
4694 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4695 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
4696 Load Address: 0x00000000
4697 Entry Point: 0x00000000
4699 To verify the contents of the image (or check for corruption):
4701 -> tools/mkimage -l examples/uImage.TQM850L
4702 Image Name: 2.4.4 kernel for TQM850L
4703 Created: Wed Jul 19 02:34:59 2000
4704 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4705 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
4706 Load Address: 0x00000000
4707 Entry Point: 0x00000000
4709 NOTE: for embedded systems where boot time is critical you can trade
4710 speed for memory and install an UNCOMPRESSED image instead: this
4711 needs more space in Flash, but boots much faster since it does not
4712 need to be uncompressed:
4714 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz
4715 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
4716 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
4717 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux \
4718 > examples/uImage.TQM850L-uncompressed
4719 Image Name: 2.4.4 kernel for TQM850L
4720 Created: Wed Jul 19 02:34:59 2000
4721 Image Type: PowerPC Linux Kernel Image (uncompressed)
4722 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
4723 Load Address: 0x00000000
4724 Entry Point: 0x00000000
4727 Similar you can build U-Boot images from a 'ramdisk.image.gz' file
4728 when your kernel is intended to use an initial ramdisk:
4730 -> tools/mkimage -n 'Simple Ramdisk Image' \
4731 > -A ppc -O linux -T ramdisk -C gzip \
4732 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
4733 Image Name: Simple Ramdisk Image
4734 Created: Wed Jan 12 14:01:50 2000
4735 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
4736 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
4737 Load Address: 0x00000000
4738 Entry Point: 0x00000000
4741 Installing a Linux Image:
4742 -------------------------
4744 To downloading a U-Boot image over the serial (console) interface,
4745 you must convert the image to S-Record format:
4747 objcopy -I binary -O srec examples/image examples/image.srec
4749 The 'objcopy' does not understand the information in the U-Boot
4750 image header, so the resulting S-Record file will be relative to
4751 address 0x00000000. To load it to a given address, you need to
4752 specify the target address as 'offset' parameter with the 'loads'
4755 Example: install the image to address 0x40100000 (which on the
4756 TQM8xxL is in the first Flash bank):
4758 => erase 40100000 401FFFFF
4764 ## Ready for S-Record download ...
4765 ~>examples/image.srec
4766 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
4768 15989 15990 15991 15992
4769 [file transfer complete]
4771 ## Start Addr = 0x00000000
4774 You can check the success of the download using the 'iminfo' command;
4775 this includes a checksum verification so you can be sure no data
4776 corruption happened:
4780 ## Checking Image at 40100000 ...
4781 Image Name: 2.2.13 for initrd on TQM850L
4782 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4783 Data Size: 335725 Bytes = 327 kB = 0 MB
4784 Load Address: 00000000
4785 Entry Point: 0000000c
4786 Verifying Checksum ... OK
4792 The "bootm" command is used to boot an application that is stored in
4793 memory (RAM or Flash). In case of a Linux kernel image, the contents
4794 of the "bootargs" environment variable is passed to the kernel as
4795 parameters. You can check and modify this variable using the
4796 "printenv" and "setenv" commands:
4799 => printenv bootargs
4800 bootargs=root=/dev/ram
4802 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
4804 => printenv bootargs
4805 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
4808 ## Booting Linux kernel at 40020000 ...
4809 Image Name: 2.2.13 for NFS on TQM850L
4810 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4811 Data Size: 381681 Bytes = 372 kB = 0 MB
4812 Load Address: 00000000
4813 Entry Point: 0000000c
4814 Verifying Checksum ... OK
4815 Uncompressing Kernel Image ... OK
4816 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
4817 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
4818 time_init: decrementer frequency = 187500000/60
4819 Calibrating delay loop... 49.77 BogoMIPS
4820 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
4823 If you want to boot a Linux kernel with initial RAM disk, you pass
4824 the memory addresses of both the kernel and the initrd image (PPBCOOT
4825 format!) to the "bootm" command:
4827 => imi 40100000 40200000
4829 ## Checking Image at 40100000 ...
4830 Image Name: 2.2.13 for initrd on TQM850L
4831 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4832 Data Size: 335725 Bytes = 327 kB = 0 MB
4833 Load Address: 00000000
4834 Entry Point: 0000000c
4835 Verifying Checksum ... OK
4837 ## Checking Image at 40200000 ...
4838 Image Name: Simple Ramdisk Image
4839 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
4840 Data Size: 566530 Bytes = 553 kB = 0 MB
4841 Load Address: 00000000
4842 Entry Point: 00000000
4843 Verifying Checksum ... OK
4845 => bootm 40100000 40200000
4846 ## Booting Linux kernel at 40100000 ...
4847 Image Name: 2.2.13 for initrd on TQM850L
4848 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4849 Data Size: 335725 Bytes = 327 kB = 0 MB
4850 Load Address: 00000000
4851 Entry Point: 0000000c
4852 Verifying Checksum ... OK
4853 Uncompressing Kernel Image ... OK
4854 ## Loading RAMDisk Image at 40200000 ...
4855 Image Name: Simple Ramdisk Image
4856 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
4857 Data Size: 566530 Bytes = 553 kB = 0 MB
4858 Load Address: 00000000
4859 Entry Point: 00000000
4860 Verifying Checksum ... OK
4861 Loading Ramdisk ... OK
4862 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
4863 Boot arguments: root=/dev/ram
4864 time_init: decrementer frequency = 187500000/60
4865 Calibrating delay loop... 49.77 BogoMIPS
4867 RAMDISK: Compressed image found at block 0
4868 VFS: Mounted root (ext2 filesystem).
4872 Boot Linux and pass a flat device tree:
4875 First, U-Boot must be compiled with the appropriate defines. See the section
4876 titled "Linux Kernel Interface" above for a more in depth explanation. The
4877 following is an example of how to start a kernel and pass an updated
4883 oft=oftrees/mpc8540ads.dtb
4884 => tftp $oftaddr $oft
4885 Speed: 1000, full duplex
4887 TFTP from server 192.168.1.1; our IP address is 192.168.1.101
4888 Filename 'oftrees/mpc8540ads.dtb'.
4889 Load address: 0x300000
4892 Bytes transferred = 4106 (100a hex)
4893 => tftp $loadaddr $bootfile
4894 Speed: 1000, full duplex
4896 TFTP from server 192.168.1.1; our IP address is 192.168.1.2
4898 Load address: 0x200000
4899 Loading:############
4901 Bytes transferred = 1029407 (fb51f hex)
4906 => bootm $loadaddr - $oftaddr
4907 ## Booting image at 00200000 ...
4908 Image Name: Linux-2.6.17-dirty
4909 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4910 Data Size: 1029343 Bytes = 1005.2 kB
4911 Load Address: 00000000
4912 Entry Point: 00000000
4913 Verifying Checksum ... OK
4914 Uncompressing Kernel Image ... OK
4915 Booting using flat device tree at 0x300000
4916 Using MPC85xx ADS machine description
4917 Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb
4921 More About U-Boot Image Types:
4922 ------------------------------
4924 U-Boot supports the following image types:
4926 "Standalone Programs" are directly runnable in the environment
4927 provided by U-Boot; it is expected that (if they behave
4928 well) you can continue to work in U-Boot after return from
4929 the Standalone Program.
4930 "OS Kernel Images" are usually images of some Embedded OS which
4931 will take over control completely. Usually these programs
4932 will install their own set of exception handlers, device
4933 drivers, set up the MMU, etc. - this means, that you cannot
4934 expect to re-enter U-Boot except by resetting the CPU.
4935 "RAMDisk Images" are more or less just data blocks, and their
4936 parameters (address, size) are passed to an OS kernel that is
4938 "Multi-File Images" contain several images, typically an OS
4939 (Linux) kernel image and one or more data images like
4940 RAMDisks. This construct is useful for instance when you want
4941 to boot over the network using BOOTP etc., where the boot
4942 server provides just a single image file, but you want to get
4943 for instance an OS kernel and a RAMDisk image.
4945 "Multi-File Images" start with a list of image sizes, each
4946 image size (in bytes) specified by an "uint32_t" in network
4947 byte order. This list is terminated by an "(uint32_t)0".
4948 Immediately after the terminating 0 follow the images, one by
4949 one, all aligned on "uint32_t" boundaries (size rounded up to
4950 a multiple of 4 bytes).
4952 "Firmware Images" are binary images containing firmware (like
4953 U-Boot or FPGA images) which usually will be programmed to
4956 "Script files" are command sequences that will be executed by
4957 U-Boot's command interpreter; this feature is especially
4958 useful when you configure U-Boot to use a real shell (hush)
4959 as command interpreter.
4961 Booting the Linux zImage:
4962 -------------------------
4964 On some platforms, it's possible to boot Linux zImage. This is done
4965 using the "bootz" command. The syntax of "bootz" command is the same
4966 as the syntax of "bootm" command.
4968 Note, defining the CONFIG_SUPPORT_INITRD_RAW allows user to supply
4969 kernel with raw initrd images. The syntax is slightly different, the
4970 address of the initrd must be augmented by it's size, in the following
4971 format: "<initrd addres>:<initrd size>".
4977 One of the features of U-Boot is that you can dynamically load and
4978 run "standalone" applications, which can use some resources of
4979 U-Boot like console I/O functions or interrupt services.
4981 Two simple examples are included with the sources:
4986 'examples/hello_world.c' contains a small "Hello World" Demo
4987 application; it is automatically compiled when you build U-Boot.
4988 It's configured to run at address 0x00040004, so you can play with it
4992 ## Ready for S-Record download ...
4993 ~>examples/hello_world.srec
4994 1 2 3 4 5 6 7 8 9 10 11 ...
4995 [file transfer complete]
4997 ## Start Addr = 0x00040004
4999 => go 40004 Hello World! This is a test.
5000 ## Starting application at 0x00040004 ...
5011 Hit any key to exit ...
5013 ## Application terminated, rc = 0x0
5015 Another example, which demonstrates how to register a CPM interrupt
5016 handler with the U-Boot code, can be found in 'examples/timer.c'.
5017 Here, a CPM timer is set up to generate an interrupt every second.
5018 The interrupt service routine is trivial, just printing a '.'
5019 character, but this is just a demo program. The application can be
5020 controlled by the following keys:
5022 ? - print current values og the CPM Timer registers
5023 b - enable interrupts and start timer
5024 e - stop timer and disable interrupts
5025 q - quit application
5028 ## Ready for S-Record download ...
5029 ~>examples/timer.srec
5030 1 2 3 4 5 6 7 8 9 10 11 ...
5031 [file transfer complete]
5033 ## Start Addr = 0x00040004
5036 ## Starting application at 0x00040004 ...
5039 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
5042 [q, b, e, ?] Set interval 1000000 us
5045 [q, b, e, ?] ........
5046 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
5049 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
5052 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
5055 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
5057 [q, b, e, ?] ...Stopping timer
5059 [q, b, e, ?] ## Application terminated, rc = 0x0
5065 Over time, many people have reported problems when trying to use the
5066 "minicom" terminal emulation program for serial download. I (wd)
5067 consider minicom to be broken, and recommend not to use it. Under
5068 Unix, I recommend to use C-Kermit for general purpose use (and
5069 especially for kermit binary protocol download ("loadb" command), and
5070 use "cu" for S-Record download ("loads" command). See
5071 http://www.denx.de/wiki/view/DULG/SystemSetup#Section_4.3.
5072 for help with kermit.
5075 Nevertheless, if you absolutely want to use it try adding this
5076 configuration to your "File transfer protocols" section:
5078 Name Program Name U/D FullScr IO-Red. Multi
5079 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
5080 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
5086 Starting at version 0.9.2, U-Boot supports NetBSD both as host
5087 (build U-Boot) and target system (boots NetBSD/mpc8xx).
5089 Building requires a cross environment; it is known to work on
5090 NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
5091 need gmake since the Makefiles are not compatible with BSD make).
5092 Note that the cross-powerpc package does not install include files;
5093 attempting to build U-Boot will fail because <machine/ansi.h> is
5094 missing. This file has to be installed and patched manually:
5096 # cd /usr/pkg/cross/powerpc-netbsd/include
5098 # ln -s powerpc machine
5099 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
5100 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
5102 Native builds *don't* work due to incompatibilities between native
5103 and U-Boot include files.
5105 Booting assumes that (the first part of) the image booted is a
5106 stage-2 loader which in turn loads and then invokes the kernel
5107 proper. Loader sources will eventually appear in the NetBSD source
5108 tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
5109 meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz
5112 Implementation Internals:
5113 =========================
5115 The following is not intended to be a complete description of every
5116 implementation detail. However, it should help to understand the
5117 inner workings of U-Boot and make it easier to port it to custom
5121 Initial Stack, Global Data:
5122 ---------------------------
5124 The implementation of U-Boot is complicated by the fact that U-Boot
5125 starts running out of ROM (flash memory), usually without access to
5126 system RAM (because the memory controller is not initialized yet).
5127 This means that we don't have writable Data or BSS segments, and BSS
5128 is not initialized as zero. To be able to get a C environment working
5129 at all, we have to allocate at least a minimal stack. Implementation
5130 options for this are defined and restricted by the CPU used: Some CPU
5131 models provide on-chip memory (like the IMMR area on MPC8xx and
5132 MPC826x processors), on others (parts of) the data cache can be
5133 locked as (mis-) used as memory, etc.
5135 Chris Hallinan posted a good summary of these issues to the
5136 U-Boot mailing list:
5138 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
5139 From: "Chris Hallinan" <clh@net1plus.com>
5140 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
5143 Correct me if I'm wrong, folks, but the way I understand it
5144 is this: Using DCACHE as initial RAM for Stack, etc, does not
5145 require any physical RAM backing up the cache. The cleverness
5146 is that the cache is being used as a temporary supply of
5147 necessary storage before the SDRAM controller is setup. It's
5148 beyond the scope of this list to explain the details, but you
5149 can see how this works by studying the cache architecture and
5150 operation in the architecture and processor-specific manuals.
5152 OCM is On Chip Memory, which I believe the 405GP has 4K. It
5153 is another option for the system designer to use as an
5154 initial stack/RAM area prior to SDRAM being available. Either
5155 option should work for you. Using CS 4 should be fine if your
5156 board designers haven't used it for something that would
5157 cause you grief during the initial boot! It is frequently not
5160 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere
5161 with your processor/board/system design. The default value
5162 you will find in any recent u-boot distribution in
5163 walnut.h should work for you. I'd set it to a value larger
5164 than your SDRAM module. If you have a 64MB SDRAM module, set
5165 it above 400_0000. Just make sure your board has no resources
5166 that are supposed to respond to that address! That code in
5167 start.S has been around a while and should work as is when
5168 you get the config right.
5173 It is essential to remember this, since it has some impact on the C
5174 code for the initialization procedures:
5176 * Initialized global data (data segment) is read-only. Do not attempt
5179 * Do not use any uninitialized global data (or implicitely initialized
5180 as zero data - BSS segment) at all - this is undefined, initiali-
5181 zation is performed later (when relocating to RAM).
5183 * Stack space is very limited. Avoid big data buffers or things like
5186 Having only the stack as writable memory limits means we cannot use
5187 normal global data to share information beween the code. But it
5188 turned out that the implementation of U-Boot can be greatly
5189 simplified by making a global data structure (gd_t) available to all
5190 functions. We could pass a pointer to this data as argument to _all_
5191 functions, but this would bloat the code. Instead we use a feature of
5192 the GCC compiler (Global Register Variables) to share the data: we
5193 place a pointer (gd) to the global data into a register which we
5194 reserve for this purpose.
5196 When choosing a register for such a purpose we are restricted by the
5197 relevant (E)ABI specifications for the current architecture, and by
5198 GCC's implementation.
5200 For PowerPC, the following registers have specific use:
5202 R2: reserved for system use
5203 R3-R4: parameter passing and return values
5204 R5-R10: parameter passing
5205 R13: small data area pointer
5209 (U-Boot also uses R12 as internal GOT pointer. r12
5210 is a volatile register so r12 needs to be reset when
5211 going back and forth between asm and C)
5213 ==> U-Boot will use R2 to hold a pointer to the global data
5215 Note: on PPC, we could use a static initializer (since the
5216 address of the global data structure is known at compile time),
5217 but it turned out that reserving a register results in somewhat
5218 smaller code - although the code savings are not that big (on
5219 average for all boards 752 bytes for the whole U-Boot image,
5220 624 text + 127 data).
5222 On Blackfin, the normal C ABI (except for P3) is followed as documented here:
5223 http://docs.blackfin.uclinux.org/doku.php?id=application_binary_interface
5225 ==> U-Boot will use P3 to hold a pointer to the global data
5227 On ARM, the following registers are used:
5229 R0: function argument word/integer result
5230 R1-R3: function argument word
5232 R10: stack limit (used only if stack checking if enabled)
5233 R11: argument (frame) pointer
5234 R12: temporary workspace
5237 R15: program counter
5239 ==> U-Boot will use R8 to hold a pointer to the global data
5241 On Nios II, the ABI is documented here:
5242 http://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf
5244 ==> U-Boot will use gp to hold a pointer to the global data
5246 Note: on Nios II, we give "-G0" option to gcc and don't use gp
5247 to access small data sections, so gp is free.
5249 On NDS32, the following registers are used:
5251 R0-R1: argument/return
5253 R15: temporary register for assembler
5254 R16: trampoline register
5255 R28: frame pointer (FP)
5256 R29: global pointer (GP)
5257 R30: link register (LP)
5258 R31: stack pointer (SP)
5259 PC: program counter (PC)
5261 ==> U-Boot will use R10 to hold a pointer to the global data
5263 NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope,
5264 or current versions of GCC may "optimize" the code too much.
5269 U-Boot runs in system state and uses physical addresses, i.e. the
5270 MMU is not used either for address mapping nor for memory protection.
5272 The available memory is mapped to fixed addresses using the memory
5273 controller. In this process, a contiguous block is formed for each
5274 memory type (Flash, SDRAM, SRAM), even when it consists of several
5275 physical memory banks.
5277 U-Boot is installed in the first 128 kB of the first Flash bank (on
5278 TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
5279 booting and sizing and initializing DRAM, the code relocates itself
5280 to the upper end of DRAM. Immediately below the U-Boot code some
5281 memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN
5282 configuration setting]. Below that, a structure with global Board
5283 Info data is placed, followed by the stack (growing downward).
5285 Additionally, some exception handler code is copied to the low 8 kB
5286 of DRAM (0x00000000 ... 0x00001FFF).
5288 So a typical memory configuration with 16 MB of DRAM could look like
5291 0x0000 0000 Exception Vector code
5294 0x0000 2000 Free for Application Use
5300 0x00FB FF20 Monitor Stack (Growing downward)
5301 0x00FB FFAC Board Info Data and permanent copy of global data
5302 0x00FC 0000 Malloc Arena
5305 0x00FE 0000 RAM Copy of Monitor Code
5306 ... eventually: LCD or video framebuffer
5307 ... eventually: pRAM (Protected RAM - unchanged by reset)
5308 0x00FF FFFF [End of RAM]
5311 System Initialization:
5312 ----------------------
5314 In the reset configuration, U-Boot starts at the reset entry point
5315 (on most PowerPC systems at address 0x00000100). Because of the reset
5316 configuration for CS0# this is a mirror of the onboard Flash memory.
5317 To be able to re-map memory U-Boot then jumps to its link address.
5318 To be able to implement the initialization code in C, a (small!)
5319 initial stack is set up in the internal Dual Ported RAM (in case CPUs
5320 which provide such a feature like MPC8xx or MPC8260), or in a locked
5321 part of the data cache. After that, U-Boot initializes the CPU core,
5322 the caches and the SIU.
5324 Next, all (potentially) available memory banks are mapped using a
5325 preliminary mapping. For example, we put them on 512 MB boundaries
5326 (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
5327 on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
5328 programmed for SDRAM access. Using the temporary configuration, a
5329 simple memory test is run that determines the size of the SDRAM
5332 When there is more than one SDRAM bank, and the banks are of
5333 different size, the largest is mapped first. For equal size, the first
5334 bank (CS2#) is mapped first. The first mapping is always for address
5335 0x00000000, with any additional banks following immediately to create
5336 contiguous memory starting from 0.
5338 Then, the monitor installs itself at the upper end of the SDRAM area
5339 and allocates memory for use by malloc() and for the global Board
5340 Info data; also, the exception vector code is copied to the low RAM
5341 pages, and the final stack is set up.
5343 Only after this relocation will you have a "normal" C environment;
5344 until that you are restricted in several ways, mostly because you are
5345 running from ROM, and because the code will have to be relocated to a
5349 U-Boot Porting Guide:
5350 ----------------------
5352 [Based on messages by Jerry Van Baren in the U-Boot-Users mailing
5356 int main(int argc, char *argv[])
5358 sighandler_t no_more_time;
5360 signal(SIGALRM, no_more_time);
5361 alarm(PROJECT_DEADLINE - toSec (3 * WEEK));
5363 if (available_money > available_manpower) {
5364 Pay consultant to port U-Boot;
5368 Download latest U-Boot source;
5370 Subscribe to u-boot mailing list;
5373 email("Hi, I am new to U-Boot, how do I get started?");
5376 Read the README file in the top level directory;
5377 Read http://www.denx.de/twiki/bin/view/DULG/Manual;
5378 Read applicable doc/*.README;
5379 Read the source, Luke;
5380 /* find . -name "*.[chS]" | xargs grep -i <keyword> */
5383 if (available_money > toLocalCurrency ($2500))
5386 Add a lot of aggravation and time;
5388 if (a similar board exists) { /* hopefully... */
5389 cp -a board/<similar> board/<myboard>
5390 cp include/configs/<similar>.h include/configs/<myboard>.h
5392 Create your own board support subdirectory;
5393 Create your own board include/configs/<myboard>.h file;
5395 Edit new board/<myboard> files
5396 Edit new include/configs/<myboard>.h
5401 Add / modify source code;
5405 email("Hi, I am having problems...");
5407 Send patch file to the U-Boot email list;
5408 if (reasonable critiques)
5409 Incorporate improvements from email list code review;
5411 Defend code as written;
5417 void no_more_time (int sig)
5426 All contributions to U-Boot should conform to the Linux kernel
5427 coding style; see the file "Documentation/CodingStyle" and the script
5428 "scripts/Lindent" in your Linux kernel source directory.
5430 Source files originating from a different project (for example the
5431 MTD subsystem) are generally exempt from these guidelines and are not
5432 reformated to ease subsequent migration to newer versions of those
5435 Please note that U-Boot is implemented in C (and to some small parts in
5436 Assembler); no C++ is used, so please do not use C++ style comments (//)
5439 Please also stick to the following formatting rules:
5440 - remove any trailing white space
5441 - use TAB characters for indentation and vertical alignment, not spaces
5442 - make sure NOT to use DOS '\r\n' line feeds
5443 - do not add more than 2 consecutive empty lines to source files
5444 - do not add trailing empty lines to source files
5446 Submissions which do not conform to the standards may be returned
5447 with a request to reformat the changes.
5453 Since the number of patches for U-Boot is growing, we need to
5454 establish some rules. Submissions which do not conform to these rules
5455 may be rejected, even when they contain important and valuable stuff.
5457 Please see http://www.denx.de/wiki/U-Boot/Patches for details.
5459 Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>;
5460 see http://lists.denx.de/mailman/listinfo/u-boot
5462 When you send a patch, please include the following information with
5465 * For bug fixes: a description of the bug and how your patch fixes
5466 this bug. Please try to include a way of demonstrating that the
5467 patch actually fixes something.
5469 * For new features: a description of the feature and your
5472 * A CHANGELOG entry as plaintext (separate from the patch)
5474 * For major contributions, your entry to the CREDITS file
5476 * When you add support for a new board, don't forget to add this
5477 board to the MAINTAINERS file, too.
5479 * If your patch adds new configuration options, don't forget to
5480 document these in the README file.
5482 * The patch itself. If you are using git (which is *strongly*
5483 recommended) you can easily generate the patch using the
5484 "git format-patch". If you then use "git send-email" to send it to
5485 the U-Boot mailing list, you will avoid most of the common problems
5486 with some other mail clients.
5488 If you cannot use git, use "diff -purN OLD NEW". If your version of
5489 diff does not support these options, then get the latest version of
5492 The current directory when running this command shall be the parent
5493 directory of the U-Boot source tree (i. e. please make sure that
5494 your patch includes sufficient directory information for the
5497 We prefer patches as plain text. MIME attachments are discouraged,
5498 and compressed attachments must not be used.
5500 * If one logical set of modifications affects or creates several
5501 files, all these changes shall be submitted in a SINGLE patch file.
5503 * Changesets that contain different, unrelated modifications shall be
5504 submitted as SEPARATE patches, one patch per changeset.
5509 * Before sending the patch, run the MAKEALL script on your patched
5510 source tree and make sure that no errors or warnings are reported
5511 for any of the boards.
5513 * Keep your modifications to the necessary minimum: A patch
5514 containing several unrelated changes or arbitrary reformats will be
5515 returned with a request to re-formatting / split it.
5517 * If you modify existing code, make sure that your new code does not
5518 add to the memory footprint of the code ;-) Small is beautiful!
5519 When adding new features, these should compile conditionally only
5520 (using #ifdef), and the resulting code with the new feature
5521 disabled must not need more memory than the old code without your
5524 * Remember that there is a size limit of 100 kB per message on the
5525 u-boot mailing list. Bigger patches will be moderated. If they are
5526 reasonable and not too big, they will be acknowledged. But patches
5527 bigger than the size limit should be avoided.
projects / kernel / u-boot.git / blob