2 # (C) Copyright 2000 - 2009
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
61 In case you have questions about, problems with or contributions for
62 U-Boot you should send a message to the U-Boot mailing list at
63 <u-boot@lists.denx.de>. There is also an archive of previous traffic
64 on the mailing list - please search the archive before asking FAQ's.
65 Please see http://lists.denx.de/pipermail/u-boot and
66 http://dir.gmane.org/gmane.comp.boot-loaders.u-boot
69 Where to get source code:
70 =========================
72 The U-Boot source code is maintained in the git repository at
73 git://www.denx.de/git/u-boot.git ; you can browse it online at
74 http://www.denx.de/cgi-bin/gitweb.cgi?p=u-boot.git;a=summary
76 The "snapshot" links on this page allow you to download tarballs of
77 any version you might be interested in. Official releases are also
78 available for FTP download from the ftp://ftp.denx.de/pub/u-boot/
81 Pre-built (and tested) images are available from
82 ftp://ftp.denx.de/pub/u-boot/images/
88 - start from 8xxrom sources
89 - create PPCBoot project (http://sourceforge.net/projects/ppcboot)
91 - make it easier to add custom boards
92 - make it possible to add other [PowerPC] CPUs
93 - extend functions, especially:
94 * Provide extended interface to Linux boot loader
97 * PCMCIA / CompactFlash / ATA disk / SCSI ... boot
98 - create ARMBoot project (http://sourceforge.net/projects/armboot)
99 - add other CPU families (starting with ARM)
100 - create U-Boot project (http://sourceforge.net/projects/u-boot)
101 - current project page: see http://www.denx.de/wiki/U-Boot
107 The "official" name of this project is "Das U-Boot". The spelling
108 "U-Boot" shall be used in all written text (documentation, comments
109 in source files etc.). Example:
111 This is the README file for the U-Boot project.
113 File names etc. shall be based on the string "u-boot". Examples:
115 include/asm-ppc/u-boot.h
117 #include <asm/u-boot.h>
119 Variable names, preprocessor constants etc. shall be either based on
120 the string "u_boot" or on "U_BOOT". Example:
122 U_BOOT_VERSION u_boot_logo
123 IH_OS_U_BOOT u_boot_hush_start
129 Starting with the release in October 2008, the names of the releases
130 were changed from numerical release numbers without deeper meaning
131 into a time stamp based numbering. Regular releases are identified by
132 names consisting of the calendar year and month of the release date.
133 Additional fields (if present) indicate release candidates or bug fix
134 releases in "stable" maintenance trees.
137 U-Boot v2009.11 - Release November 2009
138 U-Boot v2009.11.1 - Release 1 in version November 2009 stable tree
139 U-Boot v2010.09-rc1 - Release candiate 1 for September 2010 release
145 /arch Architecture specific files
146 /arm Files generic to ARM architecture
147 /cpu CPU specific files
148 /arm720t Files specific to ARM 720 CPUs
149 /arm920t Files specific to ARM 920 CPUs
150 /at91rm9200 Files specific to Atmel AT91RM9200 CPU
151 /imx Files specific to Freescale MC9328 i.MX CPUs
152 /s3c24x0 Files specific to Samsung S3C24X0 CPUs
153 /arm925t Files specific to ARM 925 CPUs
154 /arm926ejs Files specific to ARM 926 CPUs
155 /arm1136 Files specific to ARM 1136 CPUs
156 /ixp Files specific to Intel XScale IXP CPUs
157 /pxa Files specific to Intel XScale PXA CPUs
158 /s3c44b0 Files specific to Samsung S3C44B0 CPUs
159 /sa1100 Files specific to Intel StrongARM SA1100 CPUs
160 /lib Architecture specific library files
161 /avr32 Files generic to AVR32 architecture
162 /cpu CPU specific files
163 /lib Architecture specific library files
164 /blackfin Files generic to Analog Devices Blackfin architecture
165 /cpu CPU specific files
166 /lib Architecture specific library files
167 /i386 Files generic to i386 architecture
168 /cpu CPU specific files
169 /lib Architecture specific library files
170 /m68k Files generic to m68k architecture
171 /cpu CPU specific files
172 /mcf52x2 Files specific to Freescale ColdFire MCF52x2 CPUs
173 /mcf5227x Files specific to Freescale ColdFire MCF5227x CPUs
174 /mcf532x Files specific to Freescale ColdFire MCF5329 CPUs
175 /mcf5445x Files specific to Freescale ColdFire MCF5445x CPUs
176 /mcf547x_8x Files specific to Freescale ColdFire MCF547x_8x CPUs
177 /lib Architecture specific library files
178 /microblaze Files generic to microblaze architecture
179 /cpu CPU specific files
180 /lib Architecture specific library files
181 /mips Files generic to MIPS architecture
182 /cpu CPU specific files
183 /lib Architecture specific library files
184 /nios2 Files generic to Altera NIOS2 architecture
185 /cpu CPU specific files
186 /lib Architecture specific library files
187 /powerpc Files generic to PowerPC architecture
188 /cpu CPU specific files
189 /74xx_7xx Files specific to Freescale MPC74xx and 7xx CPUs
190 /mpc5xx Files specific to Freescale MPC5xx CPUs
191 /mpc5xxx Files specific to Freescale MPC5xxx CPUs
192 /mpc8xx Files specific to Freescale MPC8xx CPUs
193 /mpc8220 Files specific to Freescale MPC8220 CPUs
194 /mpc824x Files specific to Freescale MPC824x CPUs
195 /mpc8260 Files specific to Freescale MPC8260 CPUs
196 /mpc85xx Files specific to Freescale MPC85xx CPUs
197 /ppc4xx Files specific to AMCC PowerPC 4xx CPUs
198 /lib Architecture specific library files
199 /sh Files generic to SH architecture
200 /cpu CPU specific files
201 /sh2 Files specific to sh2 CPUs
202 /sh3 Files specific to sh3 CPUs
203 /sh4 Files specific to sh4 CPUs
204 /lib Architecture specific library files
205 /sparc Files generic to SPARC architecture
206 /cpu CPU specific files
207 /leon2 Files specific to Gaisler LEON2 SPARC CPU
208 /leon3 Files specific to Gaisler LEON3 SPARC CPU
209 /lib Architecture specific library files
210 /api Machine/arch independent API for external apps
211 /board Board dependent files
212 /common Misc architecture independent functions
213 /disk Code for disk drive partition handling
214 /doc Documentation (don't expect too much)
215 /drivers Commonly used device drivers
216 /examples Example code for standalone applications, etc.
217 /fs Filesystem code (cramfs, ext2, jffs2, etc.)
218 /include Header Files
219 /lib Files generic to all architectures
220 /libfdt Library files to support flattened device trees
221 /lzma Library files to support LZMA decompression
222 /lzo Library files to support LZO decompression
224 /post Power On Self Test
225 /rtc Real Time Clock drivers
226 /tools Tools to build S-Record or U-Boot images, etc.
228 Software Configuration:
229 =======================
231 Configuration is usually done using C preprocessor defines; the
232 rationale behind that is to avoid dead code whenever possible.
234 There are two classes of configuration variables:
236 * Configuration _OPTIONS_:
237 These are selectable by the user and have names beginning with
240 * Configuration _SETTINGS_:
241 These depend on the hardware etc. and should not be meddled with if
242 you don't know what you're doing; they have names beginning with
245 Later we will add a configuration tool - probably similar to or even
246 identical to what's used for the Linux kernel. Right now, we have to
247 do the configuration by hand, which means creating some symbolic
248 links and editing some configuration files. We use the TQM8xxL boards
252 Selection of Processor Architecture and Board Type:
253 ---------------------------------------------------
255 For all supported boards there are ready-to-use default
256 configurations available; just type "make <board_name>_config".
258 Example: For a TQM823L module type:
263 For the Cogent platform, you need to specify the CPU type as well;
264 e.g. "make cogent_mpc8xx_config". And also configure the cogent
265 directory according to the instructions in cogent/README.
268 Configuration Options:
269 ----------------------
271 Configuration depends on the combination of board and CPU type; all
272 such information is kept in a configuration file
273 "include/configs/<board_name>.h".
275 Example: For a TQM823L module, all configuration settings are in
276 "include/configs/TQM823L.h".
279 Many of the options are named exactly as the corresponding Linux
280 kernel configuration options. The intention is to make it easier to
281 build a config tool - later.
284 The following options need to be configured:
286 - CPU Type: Define exactly one, e.g. CONFIG_MPC85XX.
288 - Board Type: Define exactly one, e.g. CONFIG_MPC8540ADS.
290 - CPU Daughterboard Type: (if CONFIG_ATSTK1000 is defined)
291 Define exactly one, e.g. CONFIG_ATSTK1002
293 - CPU Module Type: (if CONFIG_COGENT is defined)
294 Define exactly one of
296 --- FIXME --- not tested yet:
297 CONFIG_CMA286_60, CONFIG_CMA286_21, CONFIG_CMA286_60P,
298 CONFIG_CMA287_23, CONFIG_CMA287_50
300 - Motherboard Type: (if CONFIG_COGENT is defined)
301 Define exactly one of
302 CONFIG_CMA101, CONFIG_CMA102
304 - Motherboard I/O Modules: (if CONFIG_COGENT is defined)
305 Define one or more of
308 - Motherboard Options: (if CONFIG_CMA101 or CONFIG_CMA102 are defined)
309 Define one or more of
310 CONFIG_LCD_HEARTBEAT - update a character position on
311 the LCD display every second with
314 - Board flavour: (if CONFIG_MPC8260ADS is defined)
317 CONFIG_SYS_8260ADS - original MPC8260ADS
318 CONFIG_SYS_8266ADS - MPC8266ADS
319 CONFIG_SYS_PQ2FADS - PQ2FADS-ZU or PQ2FADS-VR
320 CONFIG_SYS_8272ADS - MPC8272ADS
322 - MPC824X Family Member (if CONFIG_MPC824X is defined)
323 Define exactly one of
324 CONFIG_MPC8240, CONFIG_MPC8245
326 - 8xx CPU Options: (if using an MPC8xx CPU)
327 CONFIG_8xx_GCLK_FREQ - deprecated: CPU clock if
328 get_gclk_freq() cannot work
329 e.g. if there is no 32KHz
330 reference PIT/RTC clock
331 CONFIG_8xx_OSCLK - PLL input clock (either EXTCLK
334 - 859/866/885 CPU options: (if using a MPC859 or MPC866 or MPC885 CPU):
335 CONFIG_SYS_8xx_CPUCLK_MIN
336 CONFIG_SYS_8xx_CPUCLK_MAX
337 CONFIG_8xx_CPUCLK_DEFAULT
338 See doc/README.MPC866
340 CONFIG_SYS_MEASURE_CPUCLK
342 Define this to measure the actual CPU clock instead
343 of relying on the correctness of the configured
344 values. Mostly useful for board bringup to make sure
345 the PLL is locked at the intended frequency. Note
346 that this requires a (stable) reference clock (32 kHz
347 RTC clock or CONFIG_SYS_8XX_XIN)
349 CONFIG_SYS_DELAYED_ICACHE
351 Define this option if you want to enable the
352 ICache only when Code runs from RAM.
354 - Intel Monahans options:
355 CONFIG_SYS_MONAHANS_RUN_MODE_OSC_RATIO
357 Defines the Monahans run mode to oscillator
358 ratio. Valid values are 8, 16, 24, 31. The core
359 frequency is this value multiplied by 13 MHz.
361 CONFIG_SYS_MONAHANS_TURBO_RUN_MODE_RATIO
363 Defines the Monahans turbo mode to oscillator
364 ratio. Valid values are 1 (default if undefined) and
365 2. The core frequency as calculated above is multiplied
368 - Linux Kernel Interface:
371 U-Boot stores all clock information in Hz
372 internally. For binary compatibility with older Linux
373 kernels (which expect the clocks passed in the
374 bd_info data to be in MHz) the environment variable
375 "clocks_in_mhz" can be defined so that U-Boot
376 converts clock data to MHZ before passing it to the
378 When CONFIG_CLOCKS_IN_MHZ is defined, a definition of
379 "clocks_in_mhz=1" is automatically included in the
382 CONFIG_MEMSIZE_IN_BYTES [relevant for MIPS only]
384 When transferring memsize parameter to linux, some versions
385 expect it to be in bytes, others in MB.
386 Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes.
390 New kernel versions are expecting firmware settings to be
391 passed using flattened device trees (based on open firmware
395 * New libfdt-based support
396 * Adds the "fdt" command
397 * The bootm command automatically updates the fdt
399 OF_CPU - The proper name of the cpus node (only required for
400 MPC512X and MPC5xxx based boards).
401 OF_SOC - The proper name of the soc node (only required for
402 MPC512X and MPC5xxx based boards).
403 OF_TBCLK - The timebase frequency.
404 OF_STDOUT_PATH - The path to the console device
406 boards with QUICC Engines require OF_QE to set UCC MAC
409 CONFIG_OF_BOARD_SETUP
411 Board code has addition modification that it wants to make
412 to the flat device tree before handing it off to the kernel
416 This define fills in the correct boot CPU in the boot
417 param header, the default value is zero if undefined.
421 U-Boot can detect if an IDE device is present or not.
422 If not, and this new config option is activated, U-Boot
423 removes the ATA node from the DTS before booting Linux,
424 so the Linux IDE driver does not probe the device and
425 crash. This is needed for buggy hardware (uc101) where
426 no pull down resistor is connected to the signal IDE5V_DD7.
428 - vxWorks boot parameters:
430 bootvx constructs a valid bootline using the following
431 environments variables: bootfile, ipaddr, serverip, hostname.
432 It loads the vxWorks image pointed bootfile.
434 CONFIG_SYS_VXWORKS_BOOT_DEVICE - The vxworks device name
435 CONFIG_SYS_VXWORKS_MAC_PTR - Ethernet 6 byte MA -address
436 CONFIG_SYS_VXWORKS_SERVERNAME - Name of the server
437 CONFIG_SYS_VXWORKS_BOOT_ADDR - Address of boot parameters
439 CONFIG_SYS_VXWORKS_ADD_PARAMS
441 Add it at the end of the bootline. E.g "u=username pw=secret"
443 Note: If a "bootargs" environment is defined, it will overwride
444 the defaults discussed just above.
449 Define this if you want support for Amba PrimeCell PL010 UARTs.
453 Define this if you want support for Amba PrimeCell PL011 UARTs.
457 If you have Amba PrimeCell PL011 UARTs, set this variable to
458 the clock speed of the UARTs.
462 If you have Amba PrimeCell PL010 or PL011 UARTs on your board,
463 define this to a list of base addresses for each (supported)
464 port. See e.g. include/configs/versatile.h
468 Depending on board, define exactly one serial port
469 (like CONFIG_8xx_CONS_SMC1, CONFIG_8xx_CONS_SMC2,
470 CONFIG_8xx_CONS_SCC1, ...), or switch off the serial
471 console by defining CONFIG_8xx_CONS_NONE
473 Note: if CONFIG_8xx_CONS_NONE is defined, the serial
474 port routines must be defined elsewhere
475 (i.e. serial_init(), serial_getc(), ...)
478 Enables console device for a color framebuffer. Needs following
479 defines (cf. smiLynxEM, i8042, board/eltec/bab7xx)
480 VIDEO_FB_LITTLE_ENDIAN graphic memory organisation
482 VIDEO_HW_RECTFILL graphic chip supports
485 VIDEO_HW_BITBLT graphic chip supports
486 bit-blit (cf. smiLynxEM)
487 VIDEO_VISIBLE_COLS visible pixel columns
489 VIDEO_VISIBLE_ROWS visible pixel rows
490 VIDEO_PIXEL_SIZE bytes per pixel
491 VIDEO_DATA_FORMAT graphic data format
492 (0-5, cf. cfb_console.c)
493 VIDEO_FB_ADRS framebuffer address
494 VIDEO_KBD_INIT_FCT keyboard int fct
495 (i.e. i8042_kbd_init())
496 VIDEO_TSTC_FCT test char fct
498 VIDEO_GETC_FCT get char fct
500 CONFIG_CONSOLE_CURSOR cursor drawing on/off
501 (requires blink timer
503 CONFIG_SYS_CONSOLE_BLINK_COUNT blink interval (cf. i8042.c)
504 CONFIG_CONSOLE_TIME display time/date info in
506 (requires CONFIG_CMD_DATE)
507 CONFIG_VIDEO_LOGO display Linux logo in
509 CONFIG_VIDEO_BMP_LOGO use bmp_logo.h instead of
510 linux_logo.h for logo.
511 Requires CONFIG_VIDEO_LOGO
512 CONFIG_CONSOLE_EXTRA_INFO
513 additional board info beside
516 When CONFIG_CFB_CONSOLE is defined, video console is
517 default i/o. Serial console can be forced with
518 environment 'console=serial'.
520 When CONFIG_SILENT_CONSOLE is defined, all console
521 messages (by U-Boot and Linux!) can be silenced with
522 the "silent" environment variable. See
523 doc/README.silent for more information.
526 CONFIG_BAUDRATE - in bps
527 Select one of the baudrates listed in
528 CONFIG_SYS_BAUDRATE_TABLE, see below.
529 CONFIG_SYS_BRGCLK_PRESCALE, baudrate prescale
531 - Console Rx buffer length
532 With CONFIG_SYS_SMC_RXBUFLEN it is possible to define
533 the maximum receive buffer length for the SMC.
534 This option is actual only for 82xx and 8xx possible.
535 If using CONFIG_SYS_SMC_RXBUFLEN also CONFIG_SYS_MAXIDLE
536 must be defined, to setup the maximum idle timeout for
539 - Boot Delay: CONFIG_BOOTDELAY - in seconds
540 Delay before automatically booting the default image;
541 set to -1 to disable autoboot.
543 See doc/README.autoboot for these options that
544 work with CONFIG_BOOTDELAY. None are required.
545 CONFIG_BOOT_RETRY_TIME
546 CONFIG_BOOT_RETRY_MIN
547 CONFIG_AUTOBOOT_KEYED
548 CONFIG_AUTOBOOT_PROMPT
549 CONFIG_AUTOBOOT_DELAY_STR
550 CONFIG_AUTOBOOT_STOP_STR
551 CONFIG_AUTOBOOT_DELAY_STR2
552 CONFIG_AUTOBOOT_STOP_STR2
553 CONFIG_ZERO_BOOTDELAY_CHECK
554 CONFIG_RESET_TO_RETRY
558 Only needed when CONFIG_BOOTDELAY is enabled;
559 define a command string that is automatically executed
560 when no character is read on the console interface
561 within "Boot Delay" after reset.
564 This can be used to pass arguments to the bootm
565 command. The value of CONFIG_BOOTARGS goes into the
566 environment value "bootargs".
568 CONFIG_RAMBOOT and CONFIG_NFSBOOT
569 The value of these goes into the environment as
570 "ramboot" and "nfsboot" respectively, and can be used
571 as a convenience, when switching between booting from
577 When this option is #defined, the existence of the
578 environment variable "preboot" will be checked
579 immediately before starting the CONFIG_BOOTDELAY
580 countdown and/or running the auto-boot command resp.
581 entering interactive mode.
583 This feature is especially useful when "preboot" is
584 automatically generated or modified. For an example
585 see the LWMON board specific code: here "preboot" is
586 modified when the user holds down a certain
587 combination of keys on the (special) keyboard when
590 - Serial Download Echo Mode:
592 If defined to 1, all characters received during a
593 serial download (using the "loads" command) are
594 echoed back. This might be needed by some terminal
595 emulations (like "cu"), but may as well just take
596 time on others. This setting #define's the initial
597 value of the "loads_echo" environment variable.
599 - Kgdb Serial Baudrate: (if CONFIG_CMD_KGDB is defined)
601 Select one of the baudrates listed in
602 CONFIG_SYS_BAUDRATE_TABLE, see below.
605 Monitor commands can be included or excluded
606 from the build by using the #include files
607 "config_cmd_all.h" and #undef'ing unwanted
608 commands, or using "config_cmd_default.h"
609 and augmenting with additional #define's
612 The default command configuration includes all commands
613 except those marked below with a "*".
615 CONFIG_CMD_ASKENV * ask for env variable
616 CONFIG_CMD_BDI bdinfo
617 CONFIG_CMD_BEDBUG * Include BedBug Debugger
618 CONFIG_CMD_BMP * BMP support
619 CONFIG_CMD_BSP * Board specific commands
620 CONFIG_CMD_BOOTD bootd
621 CONFIG_CMD_CACHE * icache, dcache
622 CONFIG_CMD_CONSOLE coninfo
623 CONFIG_CMD_DATE * support for RTC, date/time...
624 CONFIG_CMD_DHCP * DHCP support
625 CONFIG_CMD_DIAG * Diagnostics
626 CONFIG_CMD_DS4510 * ds4510 I2C gpio commands
627 CONFIG_CMD_DS4510_INFO * ds4510 I2C info command
628 CONFIG_CMD_DS4510_MEM * ds4510 I2C eeprom/sram commansd
629 CONFIG_CMD_DS4510_RST * ds4510 I2C rst command
630 CONFIG_CMD_DTT * Digital Therm and Thermostat
631 CONFIG_CMD_ECHO echo arguments
632 CONFIG_CMD_EDITENV edit env variable
633 CONFIG_CMD_EEPROM * EEPROM read/write support
634 CONFIG_CMD_ELF * bootelf, bootvx
635 CONFIG_CMD_SAVEENV saveenv
636 CONFIG_CMD_FDC * Floppy Disk Support
637 CONFIG_CMD_FAT * FAT partition support
638 CONFIG_CMD_FDOS * Dos diskette Support
639 CONFIG_CMD_FLASH flinfo, erase, protect
640 CONFIG_CMD_FPGA FPGA device initialization support
641 CONFIG_CMD_HWFLOW * RTS/CTS hw flow control
642 CONFIG_CMD_I2C * I2C serial bus support
643 CONFIG_CMD_IDE * IDE harddisk support
644 CONFIG_CMD_IMI iminfo
645 CONFIG_CMD_IMLS List all found images
646 CONFIG_CMD_IMMAP * IMMR dump support
647 CONFIG_CMD_IRQ * irqinfo
648 CONFIG_CMD_ITEST Integer/string test of 2 values
649 CONFIG_CMD_JFFS2 * JFFS2 Support
650 CONFIG_CMD_KGDB * kgdb
651 CONFIG_CMD_LOADB loadb
652 CONFIG_CMD_LOADS loads
653 CONFIG_CMD_MD5SUM print md5 message digest
654 (requires CONFIG_CMD_MEMORY and CONFIG_MD5)
655 CONFIG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base,
657 CONFIG_CMD_MISC Misc functions like sleep etc
658 CONFIG_CMD_MMC * MMC memory mapped support
659 CONFIG_CMD_MII * MII utility commands
660 CONFIG_CMD_MTDPARTS * MTD partition support
661 CONFIG_CMD_NAND * NAND support
662 CONFIG_CMD_NET bootp, tftpboot, rarpboot
663 CONFIG_CMD_PCA953X * PCA953x I2C gpio commands
664 CONFIG_CMD_PCA953X_INFO * PCA953x I2C gpio info command
665 CONFIG_CMD_PCI * pciinfo
666 CONFIG_CMD_PCMCIA * PCMCIA support
667 CONFIG_CMD_PING * send ICMP ECHO_REQUEST to network
669 CONFIG_CMD_PORTIO * Port I/O
670 CONFIG_CMD_REGINFO * Register dump
671 CONFIG_CMD_RUN run command in env variable
672 CONFIG_CMD_SAVES * save S record dump
673 CONFIG_CMD_SCSI * SCSI Support
674 CONFIG_CMD_SDRAM * print SDRAM configuration information
675 (requires CONFIG_CMD_I2C)
676 CONFIG_CMD_SETGETDCR Support for DCR Register access
678 CONFIG_CMD_SHA1SUM print sha1 memory digest
679 (requires CONFIG_CMD_MEMORY)
680 CONFIG_CMD_SOURCE "source" command Support
681 CONFIG_CMD_SPI * SPI serial bus support
682 CONFIG_CMD_USB * USB support
683 CONFIG_CMD_VFD * VFD support (TRAB)
684 CONFIG_CMD_CDP * Cisco Discover Protocol support
685 CONFIG_CMD_FSL * Microblaze FSL support
688 EXAMPLE: If you want all functions except of network
689 support you can write:
691 #include "config_cmd_all.h"
692 #undef CONFIG_CMD_NET
695 fdt (flattened device tree) command: CONFIG_OF_LIBFDT
697 Note: Don't enable the "icache" and "dcache" commands
698 (configuration option CONFIG_CMD_CACHE) unless you know
699 what you (and your U-Boot users) are doing. Data
700 cache cannot be enabled on systems like the 8xx or
701 8260 (where accesses to the IMMR region must be
702 uncached), and it cannot be disabled on all other
703 systems where we (mis-) use the data cache to hold an
704 initial stack and some data.
707 XXX - this list needs to get updated!
711 If this variable is defined, it enables watchdog
712 support. There must be support in the platform specific
713 code for a watchdog. For the 8xx and 8260 CPUs, the
714 SIU Watchdog feature is enabled in the SYPCR
718 CONFIG_VERSION_VARIABLE
719 If this variable is defined, an environment variable
720 named "ver" is created by U-Boot showing the U-Boot
721 version as printed by the "version" command.
722 This variable is readonly.
726 When CONFIG_CMD_DATE is selected, the type of the RTC
727 has to be selected, too. Define exactly one of the
730 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx
731 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC
732 CONFIG_RTC_MC13783 - use MC13783 RTC
733 CONFIG_RTC_MC146818 - use MC146818 RTC
734 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC
735 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC
736 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC
737 CONFIG_RTC_DS164x - use Dallas DS164x RTC
738 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC
739 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC
740 CONFIG_SYS_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337
742 Note that if the RTC uses I2C, then the I2C interface
743 must also be configured. See I2C Support, below.
746 CONFIG_PCA953X - use NXP's PCA953X series I2C GPIO
747 CONFIG_PCA953X_INFO - enable pca953x info command
749 The CONFIG_SYS_I2C_PCA953X_WIDTH option specifies a list of
750 chip-ngpio pairs that tell the PCA953X driver the number of
751 pins supported by a particular chip.
753 Note that if the GPIO device uses I2C, then the I2C interface
754 must also be configured. See I2C Support, below.
758 When CONFIG_TIMESTAMP is selected, the timestamp
759 (date and time) of an image is printed by image
760 commands like bootm or iminfo. This option is
761 automatically enabled when you select CONFIG_CMD_DATE .
764 CONFIG_MAC_PARTITION and/or CONFIG_DOS_PARTITION
765 and/or CONFIG_ISO_PARTITION and/or CONFIG_EFI_PARTITION
767 If IDE or SCSI support is enabled (CONFIG_CMD_IDE or
768 CONFIG_CMD_SCSI) you must configure support for at
769 least one partition type as well.
772 CONFIG_IDE_RESET_ROUTINE - this is defined in several
773 board configurations files but used nowhere!
775 CONFIG_IDE_RESET - is this is defined, IDE Reset will
776 be performed by calling the function
777 ide_set_reset(int reset)
778 which has to be defined in a board specific file
783 Set this to enable ATAPI support.
788 Set this to enable support for disks larger than 137GB
789 Also look at CONFIG_SYS_64BIT_LBA.
790 Whithout these , LBA48 support uses 32bit variables and will 'only'
791 support disks up to 2.1TB.
793 CONFIG_SYS_64BIT_LBA:
794 When enabled, makes the IDE subsystem use 64bit sector addresses.
798 At the moment only there is only support for the
799 SYM53C8XX SCSI controller; define
800 CONFIG_SCSI_SYM53C8XX to enable it.
802 CONFIG_SYS_SCSI_MAX_LUN [8], CONFIG_SYS_SCSI_MAX_SCSI_ID [7] and
803 CONFIG_SYS_SCSI_MAX_DEVICE [CONFIG_SYS_SCSI_MAX_SCSI_ID *
804 CONFIG_SYS_SCSI_MAX_LUN] can be adjusted to define the
805 maximum numbers of LUNs, SCSI ID's and target
807 CONFIG_SYS_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz)
809 - NETWORK Support (PCI):
811 Support for Intel 8254x gigabit chips.
813 CONFIG_E1000_FALLBACK_MAC
814 default MAC for empty EEPROM after production.
817 Support for Intel 82557/82559/82559ER chips.
818 Optional CONFIG_EEPRO100_SROM_WRITE enables EEPROM
819 write routine for first time initialisation.
822 Support for Digital 2114x chips.
823 Optional CONFIG_TULIP_SELECT_MEDIA for board specific
824 modem chip initialisation (KS8761/QS6611).
827 Support for National dp83815 chips.
830 Support for National dp8382[01] gigabit chips.
832 - NETWORK Support (other):
834 CONFIG_DRIVER_AT91EMAC
835 Support for AT91RM9200 EMAC.
838 Define this to use reduced MII inteface
840 CONFIG_DRIVER_AT91EMAC_QUIET
841 If this defined, the driver is quiet.
842 The driver doen't show link status messages.
844 CONFIG_DRIVER_LAN91C96
845 Support for SMSC's LAN91C96 chips.
848 Define this to hold the physical address
849 of the LAN91C96's I/O space
851 CONFIG_LAN91C96_USE_32_BIT
852 Define this to enable 32 bit addressing
854 CONFIG_DRIVER_SMC91111
855 Support for SMSC's LAN91C111 chip
858 Define this to hold the physical address
859 of the device (I/O space)
861 CONFIG_SMC_USE_32_BIT
862 Define this if data bus is 32 bits
864 CONFIG_SMC_USE_IOFUNCS
865 Define this to use i/o functions instead of macros
866 (some hardware wont work with macros)
869 Support for Faraday's FTGMAC100 Gigabit SoC Ethernet
871 CONFIG_FTGMAC100_EGIGA
872 Define this to use GE link update with gigabit PHY.
873 Define this if FTGMAC100 is connected to gigabit PHY.
874 If your system has 10/100 PHY only, it might not occur
875 wrong behavior. Because PHY usually return timeout or
876 useless data when polling gigabit status and gigabit
877 control registers. This behavior won't affect the
878 correctnessof 10/100 link speed update.
881 Support for SMSC's LAN911x and LAN921x chips
884 Define this to hold the physical address
885 of the device (I/O space)
887 CONFIG_SMC911X_32_BIT
888 Define this if data bus is 32 bits
890 CONFIG_SMC911X_16_BIT
891 Define this if data bus is 16 bits. If your processor
892 automatically converts one 32 bit word to two 16 bit
893 words you may also try CONFIG_SMC911X_32_BIT.
896 Support for Renesas on-chip Ethernet controller
898 CONFIG_SH_ETHER_USE_PORT
899 Define the number of ports to be used
901 CONFIG_SH_ETHER_PHY_ADDR
902 Define the ETH PHY's address
905 At the moment only the UHCI host controller is
906 supported (PIP405, MIP405, MPC5200); define
907 CONFIG_USB_UHCI to enable it.
908 define CONFIG_USB_KEYBOARD to enable the USB Keyboard
909 and define CONFIG_USB_STORAGE to enable the USB
912 Supported are USB Keyboards and USB Floppy drives
914 MPC5200 USB requires additional defines:
916 for 528 MHz Clock: 0x0001bbbb
920 for differential drivers: 0x00001000
921 for single ended drivers: 0x00005000
922 for differential drivers on PSC3: 0x00000100
923 for single ended drivers on PSC3: 0x00004100
924 CONFIG_SYS_USB_EVENT_POLL
925 May be defined to allow interrupt polling
926 instead of using asynchronous interrupts
929 Define the below if you wish to use the USB console.
930 Once firmware is rebuilt from a serial console issue the
931 command "setenv stdin usbtty; setenv stdout usbtty" and
932 attach your USB cable. The Unix command "dmesg" should print
933 it has found a new device. The environment variable usbtty
934 can be set to gserial or cdc_acm to enable your device to
935 appear to a USB host as a Linux gserial device or a
936 Common Device Class Abstract Control Model serial device.
937 If you select usbtty = gserial you should be able to enumerate
939 # modprobe usbserial vendor=0xVendorID product=0xProductID
940 else if using cdc_acm, simply setting the environment
941 variable usbtty to be cdc_acm should suffice. The following
942 might be defined in YourBoardName.h
945 Define this to build a UDC device
948 Define this to have a tty type of device available to
949 talk to the UDC device
951 CONFIG_SYS_CONSOLE_IS_IN_ENV
952 Define this if you want stdin, stdout &/or stderr to
956 CONFIG_SYS_USB_EXTC_CLK 0xBLAH
957 Derive USB clock from external clock "blah"
958 - CONFIG_SYS_USB_EXTC_CLK 0x02
960 CONFIG_SYS_USB_BRG_CLK 0xBLAH
961 Derive USB clock from brgclk
962 - CONFIG_SYS_USB_BRG_CLK 0x04
964 If you have a USB-IF assigned VendorID then you may wish to
965 define your own vendor specific values either in BoardName.h
966 or directly in usbd_vendor_info.h. If you don't define
967 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME,
968 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot
969 should pretend to be a Linux device to it's target host.
971 CONFIG_USBD_MANUFACTURER
972 Define this string as the name of your company for
973 - CONFIG_USBD_MANUFACTURER "my company"
975 CONFIG_USBD_PRODUCT_NAME
976 Define this string as the name of your product
977 - CONFIG_USBD_PRODUCT_NAME "acme usb device"
980 Define this as your assigned Vendor ID from the USB
981 Implementors Forum. This *must* be a genuine Vendor ID
982 to avoid polluting the USB namespace.
983 - CONFIG_USBD_VENDORID 0xFFFF
985 CONFIG_USBD_PRODUCTID
986 Define this as the unique Product ID
988 - CONFIG_USBD_PRODUCTID 0xFFFF
992 The MMC controller on the Intel PXA is supported. To
993 enable this define CONFIG_MMC. The MMC can be
994 accessed from the boot prompt by mapping the device
995 to physical memory similar to flash. Command line is
996 enabled with CONFIG_CMD_MMC. The MMC driver also works with
997 the FAT fs. This is enabled with CONFIG_CMD_FAT.
999 - Journaling Flash filesystem support:
1000 CONFIG_JFFS2_NAND, CONFIG_JFFS2_NAND_OFF, CONFIG_JFFS2_NAND_SIZE,
1001 CONFIG_JFFS2_NAND_DEV
1002 Define these for a default partition on a NAND device
1004 CONFIG_SYS_JFFS2_FIRST_SECTOR,
1005 CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS
1006 Define these for a default partition on a NOR device
1008 CONFIG_SYS_JFFS_CUSTOM_PART
1009 Define this to create an own partition. You have to provide a
1010 function struct part_info* jffs2_part_info(int part_num)
1012 If you define only one JFFS2 partition you may also want to
1013 #define CONFIG_SYS_JFFS_SINGLE_PART 1
1014 to disable the command chpart. This is the default when you
1015 have not defined a custom partition
1020 Define this to enable standard (PC-Style) keyboard
1024 Standard PC keyboard driver with US (is default) and
1025 GERMAN key layout (switch via environment 'keymap=de') support.
1026 Export function i8042_kbd_init, i8042_tstc and i8042_getc
1027 for cfb_console. Supports cursor blinking.
1032 Define this to enable video support (for output to
1035 CONFIG_VIDEO_CT69000
1037 Enable Chips & Technologies 69000 Video chip
1039 CONFIG_VIDEO_SMI_LYNXEM
1040 Enable Silicon Motion SMI 712/710/810 Video chip. The
1041 video output is selected via environment 'videoout'
1042 (1 = LCD and 2 = CRT). If videoout is undefined, CRT is
1045 For the CT69000 and SMI_LYNXEM drivers, videomode is
1046 selected via environment 'videomode'. Two different ways
1048 - "videomode=num" 'num' is a standard LiLo mode numbers.
1049 Following standard modes are supported (* is default):
1051 Colors 640x480 800x600 1024x768 1152x864 1280x1024
1052 -------------+---------------------------------------------
1053 8 bits | 0x301* 0x303 0x305 0x161 0x307
1054 15 bits | 0x310 0x313 0x316 0x162 0x319
1055 16 bits | 0x311 0x314 0x317 0x163 0x31A
1056 24 bits | 0x312 0x315 0x318 ? 0x31B
1057 -------------+---------------------------------------------
1058 (i.e. setenv videomode 317; saveenv; reset;)
1060 - "videomode=bootargs" all the video parameters are parsed
1061 from the bootargs. (See drivers/video/videomodes.c)
1064 CONFIG_VIDEO_SED13806
1065 Enable Epson SED13806 driver. This driver supports 8bpp
1066 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP
1067 or CONFIG_VIDEO_SED13806_16BPP
1072 Define this to enable a custom keyboard support.
1073 This simply calls drv_keyboard_init() which must be
1074 defined in your board-specific files.
1075 The only board using this so far is RBC823.
1077 - LCD Support: CONFIG_LCD
1079 Define this to enable LCD support (for output to LCD
1080 display); also select one of the supported displays
1081 by defining one of these:
1085 HITACHI TX09D70VM1CCA, 3.5", 240x320.
1087 CONFIG_NEC_NL6448AC33:
1089 NEC NL6448AC33-18. Active, color, single scan.
1091 CONFIG_NEC_NL6448BC20
1093 NEC NL6448BC20-08. 6.5", 640x480.
1094 Active, color, single scan.
1096 CONFIG_NEC_NL6448BC33_54
1098 NEC NL6448BC33-54. 10.4", 640x480.
1099 Active, color, single scan.
1103 Sharp 320x240. Active, color, single scan.
1104 It isn't 16x9, and I am not sure what it is.
1106 CONFIG_SHARP_LQ64D341
1108 Sharp LQ64D341 display, 640x480.
1109 Active, color, single scan.
1113 HLD1045 display, 640x480.
1114 Active, color, single scan.
1118 Optrex CBL50840-2 NF-FW 99 22 M5
1120 Hitachi LMG6912RPFC-00T
1124 320x240. Black & white.
1126 Normally display is black on white background; define
1127 CONFIG_SYS_WHITE_ON_BLACK to get it inverted.
1129 - Splash Screen Support: CONFIG_SPLASH_SCREEN
1131 If this option is set, the environment is checked for
1132 a variable "splashimage". If found, the usual display
1133 of logo, copyright and system information on the LCD
1134 is suppressed and the BMP image at the address
1135 specified in "splashimage" is loaded instead. The
1136 console is redirected to the "nulldev", too. This
1137 allows for a "silent" boot where a splash screen is
1138 loaded very quickly after power-on.
1140 CONFIG_SPLASH_SCREEN_ALIGN
1142 If this option is set the splash image can be freely positioned
1143 on the screen. Environment variable "splashpos" specifies the
1144 position as "x,y". If a positive number is given it is used as
1145 number of pixel from left/top. If a negative number is given it
1146 is used as number of pixel from right/bottom. You can also
1147 specify 'm' for centering the image.
1150 setenv splashpos m,m
1151 => image at center of screen
1153 setenv splashpos 30,20
1154 => image at x = 30 and y = 20
1156 setenv splashpos -10,m
1157 => vertically centered image
1158 at x = dspWidth - bmpWidth - 9
1160 - Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP
1162 If this option is set, additionally to standard BMP
1163 images, gzipped BMP images can be displayed via the
1164 splashscreen support or the bmp command.
1166 - Run length encoded BMP image (RLE8) support: CONFIG_VIDEO_BMP_RLE8
1168 If this option is set, 8-bit RLE compressed BMP images
1169 can be displayed via the splashscreen support or the
1172 - Compression support:
1175 If this option is set, support for bzip2 compressed
1176 images is included. If not, only uncompressed and gzip
1177 compressed images are supported.
1179 NOTE: the bzip2 algorithm requires a lot of RAM, so
1180 the malloc area (as defined by CONFIG_SYS_MALLOC_LEN) should
1185 If this option is set, support for lzma compressed
1188 Note: The LZMA algorithm adds between 2 and 4KB of code and it
1189 requires an amount of dynamic memory that is given by the
1192 (1846 + 768 << (lc + lp)) * sizeof(uint16)
1194 Where lc and lp stand for, respectively, Literal context bits
1195 and Literal pos bits.
1197 This value is upper-bounded by 14MB in the worst case. Anyway,
1198 for a ~4MB large kernel image, we have lc=3 and lp=0 for a
1199 total amount of (1846 + 768 << (3 + 0)) * 2 = ~41KB... that is
1200 a very small buffer.
1202 Use the lzmainfo tool to determinate the lc and lp values and
1203 then calculate the amount of needed dynamic memory (ensuring
1204 the appropriate CONFIG_SYS_MALLOC_LEN value).
1209 The address of PHY on MII bus.
1211 CONFIG_PHY_CLOCK_FREQ (ppc4xx)
1213 The clock frequency of the MII bus
1217 If this option is set, support for speed/duplex
1218 detection of gigabit PHY is included.
1220 CONFIG_PHY_RESET_DELAY
1222 Some PHY like Intel LXT971A need extra delay after
1223 reset before any MII register access is possible.
1224 For such PHY, set this option to the usec delay
1225 required. (minimum 300usec for LXT971A)
1227 CONFIG_PHY_CMD_DELAY (ppc4xx)
1229 Some PHY like Intel LXT971A need extra delay after
1230 command issued before MII status register can be read
1240 Define a default value for Ethernet address to use
1241 for the respective Ethernet interface, in case this
1242 is not determined automatically.
1247 Define a default value for the IP address to use for
1248 the default Ethernet interface, in case this is not
1249 determined through e.g. bootp.
1251 - Server IP address:
1254 Defines a default value for the IP address of a TFTP
1255 server to contact when using the "tftboot" command.
1257 CONFIG_KEEP_SERVERADDR
1259 Keeps the server's MAC address, in the env 'serveraddr'
1260 for passing to bootargs (like Linux's netconsole option)
1262 - Multicast TFTP Mode:
1265 Defines whether you want to support multicast TFTP as per
1266 rfc-2090; for example to work with atftp. Lets lots of targets
1267 tftp down the same boot image concurrently. Note: the Ethernet
1268 driver in use must provide a function: mcast() to join/leave a
1271 CONFIG_BOOTP_RANDOM_DELAY
1272 - BOOTP Recovery Mode:
1273 CONFIG_BOOTP_RANDOM_DELAY
1275 If you have many targets in a network that try to
1276 boot using BOOTP, you may want to avoid that all
1277 systems send out BOOTP requests at precisely the same
1278 moment (which would happen for instance at recovery
1279 from a power failure, when all systems will try to
1280 boot, thus flooding the BOOTP server. Defining
1281 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
1282 inserted before sending out BOOTP requests. The
1283 following delays are inserted then:
1285 1st BOOTP request: delay 0 ... 1 sec
1286 2nd BOOTP request: delay 0 ... 2 sec
1287 3rd BOOTP request: delay 0 ... 4 sec
1289 BOOTP requests: delay 0 ... 8 sec
1291 - DHCP Advanced Options:
1292 You can fine tune the DHCP functionality by defining
1293 CONFIG_BOOTP_* symbols:
1295 CONFIG_BOOTP_SUBNETMASK
1296 CONFIG_BOOTP_GATEWAY
1297 CONFIG_BOOTP_HOSTNAME
1298 CONFIG_BOOTP_NISDOMAIN
1299 CONFIG_BOOTP_BOOTPATH
1300 CONFIG_BOOTP_BOOTFILESIZE
1303 CONFIG_BOOTP_SEND_HOSTNAME
1304 CONFIG_BOOTP_NTPSERVER
1305 CONFIG_BOOTP_TIMEOFFSET
1306 CONFIG_BOOTP_VENDOREX
1308 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip
1309 environment variable, not the BOOTP server.
1311 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS
1312 serverip from a DHCP server, it is possible that more
1313 than one DNS serverip is offered to the client.
1314 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS
1315 serverip will be stored in the additional environment
1316 variable "dnsip2". The first DNS serverip is always
1317 stored in the variable "dnsip", when CONFIG_BOOTP_DNS
1320 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable
1321 to do a dynamic update of a DNS server. To do this, they
1322 need the hostname of the DHCP requester.
1323 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content
1324 of the "hostname" environment variable is passed as
1325 option 12 to the DHCP server.
1327 CONFIG_BOOTP_DHCP_REQUEST_DELAY
1329 A 32bit value in microseconds for a delay between
1330 receiving a "DHCP Offer" and sending the "DHCP Request".
1331 This fixes a problem with certain DHCP servers that don't
1332 respond 100% of the time to a "DHCP request". E.g. On an
1333 AT91RM9200 processor running at 180MHz, this delay needed
1334 to be *at least* 15,000 usec before a Windows Server 2003
1335 DHCP server would reply 100% of the time. I recommend at
1336 least 50,000 usec to be safe. The alternative is to hope
1337 that one of the retries will be successful but note that
1338 the DHCP timeout and retry process takes a longer than
1342 CONFIG_CDP_DEVICE_ID
1344 The device id used in CDP trigger frames.
1346 CONFIG_CDP_DEVICE_ID_PREFIX
1348 A two character string which is prefixed to the MAC address
1353 A printf format string which contains the ascii name of
1354 the port. Normally is set to "eth%d" which sets
1355 eth0 for the first Ethernet, eth1 for the second etc.
1357 CONFIG_CDP_CAPABILITIES
1359 A 32bit integer which indicates the device capabilities;
1360 0x00000010 for a normal host which does not forwards.
1364 An ascii string containing the version of the software.
1368 An ascii string containing the name of the platform.
1372 A 32bit integer sent on the trigger.
1374 CONFIG_CDP_POWER_CONSUMPTION
1376 A 16bit integer containing the power consumption of the
1377 device in .1 of milliwatts.
1379 CONFIG_CDP_APPLIANCE_VLAN_TYPE
1381 A byte containing the id of the VLAN.
1383 - Status LED: CONFIG_STATUS_LED
1385 Several configurations allow to display the current
1386 status using a LED. For instance, the LED will blink
1387 fast while running U-Boot code, stop blinking as
1388 soon as a reply to a BOOTP request was received, and
1389 start blinking slow once the Linux kernel is running
1390 (supported by a status LED driver in the Linux
1391 kernel). Defining CONFIG_STATUS_LED enables this
1394 - CAN Support: CONFIG_CAN_DRIVER
1396 Defining CONFIG_CAN_DRIVER enables CAN driver support
1397 on those systems that support this (optional)
1398 feature, like the TQM8xxL modules.
1400 - I2C Support: CONFIG_HARD_I2C | CONFIG_SOFT_I2C
1402 These enable I2C serial bus commands. Defining either of
1403 (but not both of) CONFIG_HARD_I2C or CONFIG_SOFT_I2C will
1404 include the appropriate I2C driver for the selected CPU.
1406 This will allow you to use i2c commands at the u-boot
1407 command line (as long as you set CONFIG_CMD_I2C in
1408 CONFIG_COMMANDS) and communicate with i2c based realtime
1409 clock chips. See common/cmd_i2c.c for a description of the
1410 command line interface.
1412 CONFIG_HARD_I2C selects a hardware I2C controller.
1414 CONFIG_SOFT_I2C configures u-boot to use a software (aka
1415 bit-banging) driver instead of CPM or similar hardware
1418 There are several other quantities that must also be
1419 defined when you define CONFIG_HARD_I2C or CONFIG_SOFT_I2C.
1421 In both cases you will need to define CONFIG_SYS_I2C_SPEED
1422 to be the frequency (in Hz) at which you wish your i2c bus
1423 to run and CONFIG_SYS_I2C_SLAVE to be the address of this node (ie
1424 the CPU's i2c node address).
1426 Now, the u-boot i2c code for the mpc8xx
1427 (arch/powerpc/cpu/mpc8xx/i2c.c) sets the CPU up as a master node
1428 and so its address should therefore be cleared to 0 (See,
1429 eg, MPC823e User's Manual p.16-473). So, set
1430 CONFIG_SYS_I2C_SLAVE to 0.
1432 CONFIG_SYS_I2C_INIT_MPC5XXX
1434 When a board is reset during an i2c bus transfer
1435 chips might think that the current transfer is still
1436 in progress. Reset the slave devices by sending start
1437 commands until the slave device responds.
1439 That's all that's required for CONFIG_HARD_I2C.
1441 If you use the software i2c interface (CONFIG_SOFT_I2C)
1442 then the following macros need to be defined (examples are
1443 from include/configs/lwmon.h):
1447 (Optional). Any commands necessary to enable the I2C
1448 controller or configure ports.
1450 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
1454 (Only for MPC8260 CPU). The I/O port to use (the code
1455 assumes both bits are on the same port). Valid values
1456 are 0..3 for ports A..D.
1460 The code necessary to make the I2C data line active
1461 (driven). If the data line is open collector, this
1464 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
1468 The code necessary to make the I2C data line tri-stated
1469 (inactive). If the data line is open collector, this
1472 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
1476 Code that returns TRUE if the I2C data line is high,
1479 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
1483 If <bit> is TRUE, sets the I2C data line high. If it
1484 is FALSE, it clears it (low).
1486 eg: #define I2C_SDA(bit) \
1487 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
1488 else immr->im_cpm.cp_pbdat &= ~PB_SDA
1492 If <bit> is TRUE, sets the I2C clock line high. If it
1493 is FALSE, it clears it (low).
1495 eg: #define I2C_SCL(bit) \
1496 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
1497 else immr->im_cpm.cp_pbdat &= ~PB_SCL
1501 This delay is invoked four times per clock cycle so this
1502 controls the rate of data transfer. The data rate thus
1503 is 1 / (I2C_DELAY * 4). Often defined to be something
1506 #define I2C_DELAY udelay(2)
1508 CONFIG_SOFT_I2C_GPIO_SCL / CONFIG_SOFT_I2C_GPIO_SDA
1510 If your arch supports the generic GPIO framework (asm/gpio.h),
1511 then you may alternatively define the two GPIOs that are to be
1512 used as SCL / SDA. Any of the previous I2C_xxx macros will
1513 have GPIO-based defaults assigned to them as appropriate.
1515 You should define these to the GPIO value as given directly to
1516 the generic GPIO functions.
1518 CONFIG_SYS_I2C_INIT_BOARD
1520 When a board is reset during an i2c bus transfer
1521 chips might think that the current transfer is still
1522 in progress. On some boards it is possible to access
1523 the i2c SCLK line directly, either by using the
1524 processor pin as a GPIO or by having a second pin
1525 connected to the bus. If this option is defined a
1526 custom i2c_init_board() routine in boards/xxx/board.c
1527 is run early in the boot sequence.
1529 CONFIG_SYS_I2C_BOARD_LATE_INIT
1531 An alternative to CONFIG_SYS_I2C_INIT_BOARD. If this option is
1532 defined a custom i2c_board_late_init() routine in
1533 boards/xxx/board.c is run AFTER the operations in i2c_init()
1534 is completed. This callpoint can be used to unreset i2c bus
1535 using CPU i2c controller register accesses for CPUs whose i2c
1536 controller provide such a method. It is called at the end of
1537 i2c_init() to allow i2c_init operations to setup the i2c bus
1538 controller on the CPU (e.g. setting bus speed & slave address).
1540 CONFIG_I2CFAST (PPC405GP|PPC405EP only)
1542 This option enables configuration of bi_iic_fast[] flags
1543 in u-boot bd_info structure based on u-boot environment
1544 variable "i2cfast". (see also i2cfast)
1546 CONFIG_I2C_MULTI_BUS
1548 This option allows the use of multiple I2C buses, each of which
1549 must have a controller. At any point in time, only one bus is
1550 active. To switch to a different bus, use the 'i2c dev' command.
1551 Note that bus numbering is zero-based.
1553 CONFIG_SYS_I2C_NOPROBES
1555 This option specifies a list of I2C devices that will be skipped
1556 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS
1557 is set, specify a list of bus-device pairs. Otherwise, specify
1558 a 1D array of device addresses
1561 #undef CONFIG_I2C_MULTI_BUS
1562 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68}
1564 will skip addresses 0x50 and 0x68 on a board with one I2C bus
1566 #define CONFIG_I2C_MULTI_BUS
1567 #define CONFIG_SYS_I2C_MULTI_NOPROBES {{0,0x50},{0,0x68},{1,0x54}}
1569 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1
1571 CONFIG_SYS_SPD_BUS_NUM
1573 If defined, then this indicates the I2C bus number for DDR SPD.
1574 If not defined, then U-Boot assumes that SPD is on I2C bus 0.
1576 CONFIG_SYS_RTC_BUS_NUM
1578 If defined, then this indicates the I2C bus number for the RTC.
1579 If not defined, then U-Boot assumes that RTC is on I2C bus 0.
1581 CONFIG_SYS_DTT_BUS_NUM
1583 If defined, then this indicates the I2C bus number for the DTT.
1584 If not defined, then U-Boot assumes that DTT is on I2C bus 0.
1586 CONFIG_SYS_I2C_DTT_ADDR:
1588 If defined, specifies the I2C address of the DTT device.
1589 If not defined, then U-Boot uses predefined value for
1590 specified DTT device.
1594 Define this option if you want to use Freescale's I2C driver in
1595 drivers/i2c/fsl_i2c.c.
1599 Define this option if you have I2C devices reached over 1 .. n
1600 I2C Muxes like the pca9544a. This option addes a new I2C
1601 Command "i2c bus [muxtype:muxaddr:muxchannel]" which adds a
1602 new I2C Bus to the existing I2C Busses. If you select the
1603 new Bus with "i2c dev", u-bbot sends first the commandos for
1604 the muxes to activate this new "bus".
1606 CONFIG_I2C_MULTI_BUS must be also defined, to use this
1610 Adding a new I2C Bus reached over 2 pca9544a muxes
1611 The First mux with address 70 and channel 6
1612 The Second mux with address 71 and channel 4
1614 => i2c bus pca9544a:70:6:pca9544a:71:4
1616 Use the "i2c bus" command without parameter, to get a list
1617 of I2C Busses with muxes:
1620 Busses reached over muxes:
1622 reached over Mux(es):
1625 reached over Mux(es):
1630 If you now switch to the new I2C Bus 3 with "i2c dev 3"
1631 u-boot sends First the Commando to the mux@70 to enable
1632 channel 6, and then the Commando to the mux@71 to enable
1635 After that, you can use the "normal" i2c commands as
1636 usual, to communicate with your I2C devices behind
1639 This option is actually implemented for the bitbanging
1640 algorithm in common/soft_i2c.c and for the Hardware I2C
1641 Bus on the MPC8260. But it should be not so difficult
1642 to add this option to other architectures.
1644 CONFIG_SOFT_I2C_READ_REPEATED_START
1646 defining this will force the i2c_read() function in
1647 the soft_i2c driver to perform an I2C repeated start
1648 between writing the address pointer and reading the
1649 data. If this define is omitted the default behaviour
1650 of doing a stop-start sequence will be used. Most I2C
1651 devices can use either method, but some require one or
1654 - SPI Support: CONFIG_SPI
1656 Enables SPI driver (so far only tested with
1657 SPI EEPROM, also an instance works with Crystal A/D and
1658 D/As on the SACSng board)
1662 Enables extended (16-bit) SPI EEPROM addressing.
1663 (symmetrical to CONFIG_I2C_X)
1667 Enables a software (bit-bang) SPI driver rather than
1668 using hardware support. This is a general purpose
1669 driver that only requires three general I/O port pins
1670 (two outputs, one input) to function. If this is
1671 defined, the board configuration must define several
1672 SPI configuration items (port pins to use, etc). For
1673 an example, see include/configs/sacsng.h.
1677 Enables a hardware SPI driver for general-purpose reads
1678 and writes. As with CONFIG_SOFT_SPI, the board configuration
1679 must define a list of chip-select function pointers.
1680 Currently supported on some MPC8xxx processors. For an
1681 example, see include/configs/mpc8349emds.h.
1685 Enables the driver for the SPI controllers on i.MX and MXC
1686 SoCs. Currently only i.MX31 is supported.
1688 - FPGA Support: CONFIG_FPGA
1690 Enables FPGA subsystem.
1692 CONFIG_FPGA_<vendor>
1694 Enables support for specific chip vendors.
1697 CONFIG_FPGA_<family>
1699 Enables support for FPGA family.
1700 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX)
1704 Specify the number of FPGA devices to support.
1706 CONFIG_SYS_FPGA_PROG_FEEDBACK
1708 Enable printing of hash marks during FPGA configuration.
1710 CONFIG_SYS_FPGA_CHECK_BUSY
1712 Enable checks on FPGA configuration interface busy
1713 status by the configuration function. This option
1714 will require a board or device specific function to
1719 If defined, a function that provides delays in the FPGA
1720 configuration driver.
1722 CONFIG_SYS_FPGA_CHECK_CTRLC
1723 Allow Control-C to interrupt FPGA configuration
1725 CONFIG_SYS_FPGA_CHECK_ERROR
1727 Check for configuration errors during FPGA bitfile
1728 loading. For example, abort during Virtex II
1729 configuration if the INIT_B line goes low (which
1730 indicated a CRC error).
1732 CONFIG_SYS_FPGA_WAIT_INIT
1734 Maximum time to wait for the INIT_B line to deassert
1735 after PROB_B has been deasserted during a Virtex II
1736 FPGA configuration sequence. The default time is 500
1739 CONFIG_SYS_FPGA_WAIT_BUSY
1741 Maximum time to wait for BUSY to deassert during
1742 Virtex II FPGA configuration. The default is 5 ms.
1744 CONFIG_SYS_FPGA_WAIT_CONFIG
1746 Time to wait after FPGA configuration. The default is
1749 - Configuration Management:
1752 If defined, this string will be added to the U-Boot
1753 version information (U_BOOT_VERSION)
1755 - Vendor Parameter Protection:
1757 U-Boot considers the values of the environment
1758 variables "serial#" (Board Serial Number) and
1759 "ethaddr" (Ethernet Address) to be parameters that
1760 are set once by the board vendor / manufacturer, and
1761 protects these variables from casual modification by
1762 the user. Once set, these variables are read-only,
1763 and write or delete attempts are rejected. You can
1764 change this behaviour:
1766 If CONFIG_ENV_OVERWRITE is #defined in your config
1767 file, the write protection for vendor parameters is
1768 completely disabled. Anybody can change or delete
1771 Alternatively, if you #define _both_ CONFIG_ETHADDR
1772 _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
1773 Ethernet address is installed in the environment,
1774 which can be changed exactly ONCE by the user. [The
1775 serial# is unaffected by this, i. e. it remains
1781 Define this variable to enable the reservation of
1782 "protected RAM", i. e. RAM which is not overwritten
1783 by U-Boot. Define CONFIG_PRAM to hold the number of
1784 kB you want to reserve for pRAM. You can overwrite
1785 this default value by defining an environment
1786 variable "pram" to the number of kB you want to
1787 reserve. Note that the board info structure will
1788 still show the full amount of RAM. If pRAM is
1789 reserved, a new environment variable "mem" will
1790 automatically be defined to hold the amount of
1791 remaining RAM in a form that can be passed as boot
1792 argument to Linux, for instance like that:
1794 setenv bootargs ... mem=\${mem}
1797 This way you can tell Linux not to use this memory,
1798 either, which results in a memory region that will
1799 not be affected by reboots.
1801 *WARNING* If your board configuration uses automatic
1802 detection of the RAM size, you must make sure that
1803 this memory test is non-destructive. So far, the
1804 following board configurations are known to be
1807 ETX094, IVMS8, IVML24, SPD8xx, TQM8xxL,
1808 HERMES, IP860, RPXlite, LWMON, LANTEC,
1814 Define this variable to stop the system in case of a
1815 fatal error, so that you have to reset it manually.
1816 This is probably NOT a good idea for an embedded
1817 system where you want the system to reboot
1818 automatically as fast as possible, but it may be
1819 useful during development since you can try to debug
1820 the conditions that lead to the situation.
1822 CONFIG_NET_RETRY_COUNT
1824 This variable defines the number of retries for
1825 network operations like ARP, RARP, TFTP, or BOOTP
1826 before giving up the operation. If not defined, a
1827 default value of 5 is used.
1831 Timeout waiting for an ARP reply in milliseconds.
1833 - Command Interpreter:
1834 CONFIG_AUTO_COMPLETE
1836 Enable auto completion of commands using TAB.
1838 Note that this feature has NOT been implemented yet
1839 for the "hush" shell.
1842 CONFIG_SYS_HUSH_PARSER
1844 Define this variable to enable the "hush" shell (from
1845 Busybox) as command line interpreter, thus enabling
1846 powerful command line syntax like
1847 if...then...else...fi conditionals or `&&' and '||'
1848 constructs ("shell scripts").
1850 If undefined, you get the old, much simpler behaviour
1851 with a somewhat smaller memory footprint.
1854 CONFIG_SYS_PROMPT_HUSH_PS2
1856 This defines the secondary prompt string, which is
1857 printed when the command interpreter needs more input
1858 to complete a command. Usually "> ".
1862 In the current implementation, the local variables
1863 space and global environment variables space are
1864 separated. Local variables are those you define by
1865 simply typing `name=value'. To access a local
1866 variable later on, you have write `$name' or
1867 `${name}'; to execute the contents of a variable
1868 directly type `$name' at the command prompt.
1870 Global environment variables are those you use
1871 setenv/printenv to work with. To run a command stored
1872 in such a variable, you need to use the run command,
1873 and you must not use the '$' sign to access them.
1875 To store commands and special characters in a
1876 variable, please use double quotation marks
1877 surrounding the whole text of the variable, instead
1878 of the backslashes before semicolons and special
1881 - Commandline Editing and History:
1882 CONFIG_CMDLINE_EDITING
1884 Enable editing and History functions for interactive
1885 commandline input operations
1887 - Default Environment:
1888 CONFIG_EXTRA_ENV_SETTINGS
1890 Define this to contain any number of null terminated
1891 strings (variable = value pairs) that will be part of
1892 the default environment compiled into the boot image.
1894 For example, place something like this in your
1895 board's config file:
1897 #define CONFIG_EXTRA_ENV_SETTINGS \
1901 Warning: This method is based on knowledge about the
1902 internal format how the environment is stored by the
1903 U-Boot code. This is NOT an official, exported
1904 interface! Although it is unlikely that this format
1905 will change soon, there is no guarantee either.
1906 You better know what you are doing here.
1908 Note: overly (ab)use of the default environment is
1909 discouraged. Make sure to check other ways to preset
1910 the environment like the "source" command or the
1913 - DataFlash Support:
1914 CONFIG_HAS_DATAFLASH
1916 Defining this option enables DataFlash features and
1917 allows to read/write in Dataflash via the standard
1920 - SystemACE Support:
1923 Adding this option adds support for Xilinx SystemACE
1924 chips attached via some sort of local bus. The address
1925 of the chip must also be defined in the
1926 CONFIG_SYS_SYSTEMACE_BASE macro. For example:
1928 #define CONFIG_SYSTEMACE
1929 #define CONFIG_SYS_SYSTEMACE_BASE 0xf0000000
1931 When SystemACE support is added, the "ace" device type
1932 becomes available to the fat commands, i.e. fatls.
1934 - TFTP Fixed UDP Port:
1937 If this is defined, the environment variable tftpsrcp
1938 is used to supply the TFTP UDP source port value.
1939 If tftpsrcp isn't defined, the normal pseudo-random port
1940 number generator is used.
1942 Also, the environment variable tftpdstp is used to supply
1943 the TFTP UDP destination port value. If tftpdstp isn't
1944 defined, the normal port 69 is used.
1946 The purpose for tftpsrcp is to allow a TFTP server to
1947 blindly start the TFTP transfer using the pre-configured
1948 target IP address and UDP port. This has the effect of
1949 "punching through" the (Windows XP) firewall, allowing
1950 the remainder of the TFTP transfer to proceed normally.
1951 A better solution is to properly configure the firewall,
1952 but sometimes that is not allowed.
1954 - Show boot progress:
1955 CONFIG_SHOW_BOOT_PROGRESS
1957 Defining this option allows to add some board-
1958 specific code (calling a user-provided function
1959 "show_boot_progress(int)") that enables you to show
1960 the system's boot progress on some display (for
1961 example, some LED's) on your board. At the moment,
1962 the following checkpoints are implemented:
1964 Legacy uImage format:
1967 1 common/cmd_bootm.c before attempting to boot an image
1968 -1 common/cmd_bootm.c Image header has bad magic number
1969 2 common/cmd_bootm.c Image header has correct magic number
1970 -2 common/cmd_bootm.c Image header has bad checksum
1971 3 common/cmd_bootm.c Image header has correct checksum
1972 -3 common/cmd_bootm.c Image data has bad checksum
1973 4 common/cmd_bootm.c Image data has correct checksum
1974 -4 common/cmd_bootm.c Image is for unsupported architecture
1975 5 common/cmd_bootm.c Architecture check OK
1976 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi)
1977 6 common/cmd_bootm.c Image Type check OK
1978 -6 common/cmd_bootm.c gunzip uncompression error
1979 -7 common/cmd_bootm.c Unimplemented compression type
1980 7 common/cmd_bootm.c Uncompression OK
1981 8 common/cmd_bootm.c No uncompress/copy overwrite error
1982 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX)
1984 9 common/image.c Start initial ramdisk verification
1985 -10 common/image.c Ramdisk header has bad magic number
1986 -11 common/image.c Ramdisk header has bad checksum
1987 10 common/image.c Ramdisk header is OK
1988 -12 common/image.c Ramdisk data has bad checksum
1989 11 common/image.c Ramdisk data has correct checksum
1990 12 common/image.c Ramdisk verification complete, start loading
1991 -13 common/image.c Wrong Image Type (not PPC Linux ramdisk)
1992 13 common/image.c Start multifile image verification
1993 14 common/image.c No initial ramdisk, no multifile, continue.
1995 15 arch/<arch>/lib/bootm.c All preparation done, transferring control to OS
1997 -30 arch/powerpc/lib/board.c Fatal error, hang the system
1998 -31 post/post.c POST test failed, detected by post_output_backlog()
1999 -32 post/post.c POST test failed, detected by post_run_single()
2001 34 common/cmd_doc.c before loading a Image from a DOC device
2002 -35 common/cmd_doc.c Bad usage of "doc" command
2003 35 common/cmd_doc.c correct usage of "doc" command
2004 -36 common/cmd_doc.c No boot device
2005 36 common/cmd_doc.c correct boot device
2006 -37 common/cmd_doc.c Unknown Chip ID on boot device
2007 37 common/cmd_doc.c correct chip ID found, device available
2008 -38 common/cmd_doc.c Read Error on boot device
2009 38 common/cmd_doc.c reading Image header from DOC device OK
2010 -39 common/cmd_doc.c Image header has bad magic number
2011 39 common/cmd_doc.c Image header has correct magic number
2012 -40 common/cmd_doc.c Error reading Image from DOC device
2013 40 common/cmd_doc.c Image header has correct magic number
2014 41 common/cmd_ide.c before loading a Image from a IDE device
2015 -42 common/cmd_ide.c Bad usage of "ide" command
2016 42 common/cmd_ide.c correct usage of "ide" command
2017 -43 common/cmd_ide.c No boot device
2018 43 common/cmd_ide.c boot device found
2019 -44 common/cmd_ide.c Device not available
2020 44 common/cmd_ide.c Device available
2021 -45 common/cmd_ide.c wrong partition selected
2022 45 common/cmd_ide.c partition selected
2023 -46 common/cmd_ide.c Unknown partition table
2024 46 common/cmd_ide.c valid partition table found
2025 -47 common/cmd_ide.c Invalid partition type
2026 47 common/cmd_ide.c correct partition type
2027 -48 common/cmd_ide.c Error reading Image Header on boot device
2028 48 common/cmd_ide.c reading Image Header from IDE device OK
2029 -49 common/cmd_ide.c Image header has bad magic number
2030 49 common/cmd_ide.c Image header has correct magic number
2031 -50 common/cmd_ide.c Image header has bad checksum
2032 50 common/cmd_ide.c Image header has correct checksum
2033 -51 common/cmd_ide.c Error reading Image from IDE device
2034 51 common/cmd_ide.c reading Image from IDE device OK
2035 52 common/cmd_nand.c before loading a Image from a NAND device
2036 -53 common/cmd_nand.c Bad usage of "nand" command
2037 53 common/cmd_nand.c correct usage of "nand" command
2038 -54 common/cmd_nand.c No boot device
2039 54 common/cmd_nand.c boot device found
2040 -55 common/cmd_nand.c Unknown Chip ID on boot device
2041 55 common/cmd_nand.c correct chip ID found, device available
2042 -56 common/cmd_nand.c Error reading Image Header on boot device
2043 56 common/cmd_nand.c reading Image Header from NAND device OK
2044 -57 common/cmd_nand.c Image header has bad magic number
2045 57 common/cmd_nand.c Image header has correct magic number
2046 -58 common/cmd_nand.c Error reading Image from NAND device
2047 58 common/cmd_nand.c reading Image from NAND device OK
2049 -60 common/env_common.c Environment has a bad CRC, using default
2051 64 net/eth.c starting with Ethernet configuration.
2052 -64 net/eth.c no Ethernet found.
2053 65 net/eth.c Ethernet found.
2055 -80 common/cmd_net.c usage wrong
2056 80 common/cmd_net.c before calling NetLoop()
2057 -81 common/cmd_net.c some error in NetLoop() occurred
2058 81 common/cmd_net.c NetLoop() back without error
2059 -82 common/cmd_net.c size == 0 (File with size 0 loaded)
2060 82 common/cmd_net.c trying automatic boot
2061 83 common/cmd_net.c running "source" command
2062 -83 common/cmd_net.c some error in automatic boot or "source" command
2063 84 common/cmd_net.c end without errors
2068 100 common/cmd_bootm.c Kernel FIT Image has correct format
2069 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format
2070 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration
2071 -101 common/cmd_bootm.c Can't get configuration for kernel subimage
2072 102 common/cmd_bootm.c Kernel unit name specified
2073 -103 common/cmd_bootm.c Can't get kernel subimage node offset
2074 103 common/cmd_bootm.c Found configuration node
2075 104 common/cmd_bootm.c Got kernel subimage node offset
2076 -104 common/cmd_bootm.c Kernel subimage hash verification failed
2077 105 common/cmd_bootm.c Kernel subimage hash verification OK
2078 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture
2079 106 common/cmd_bootm.c Architecture check OK
2080 -106 common/cmd_bootm.c Kernel subimage has wrong type
2081 107 common/cmd_bootm.c Kernel subimage type OK
2082 -107 common/cmd_bootm.c Can't get kernel subimage data/size
2083 108 common/cmd_bootm.c Got kernel subimage data/size
2084 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT)
2085 -109 common/cmd_bootm.c Can't get kernel subimage type
2086 -110 common/cmd_bootm.c Can't get kernel subimage comp
2087 -111 common/cmd_bootm.c Can't get kernel subimage os
2088 -112 common/cmd_bootm.c Can't get kernel subimage load address
2089 -113 common/cmd_bootm.c Image uncompress/copy overwrite error
2091 120 common/image.c Start initial ramdisk verification
2092 -120 common/image.c Ramdisk FIT image has incorrect format
2093 121 common/image.c Ramdisk FIT image has correct format
2094 122 common/image.c No ramdisk subimage unit name, using configuration
2095 -122 common/image.c Can't get configuration for ramdisk subimage
2096 123 common/image.c Ramdisk unit name specified
2097 -124 common/image.c Can't get ramdisk subimage node offset
2098 125 common/image.c Got ramdisk subimage node offset
2099 -125 common/image.c Ramdisk subimage hash verification failed
2100 126 common/image.c Ramdisk subimage hash verification OK
2101 -126 common/image.c Ramdisk subimage for unsupported architecture
2102 127 common/image.c Architecture check OK
2103 -127 common/image.c Can't get ramdisk subimage data/size
2104 128 common/image.c Got ramdisk subimage data/size
2105 129 common/image.c Can't get ramdisk load address
2106 -129 common/image.c Got ramdisk load address
2108 -130 common/cmd_doc.c Incorrect FIT image format
2109 131 common/cmd_doc.c FIT image format OK
2111 -140 common/cmd_ide.c Incorrect FIT image format
2112 141 common/cmd_ide.c FIT image format OK
2114 -150 common/cmd_nand.c Incorrect FIT image format
2115 151 common/cmd_nand.c FIT image format OK
2117 - Automatic software updates via TFTP server
2119 CONFIG_UPDATE_TFTP_CNT_MAX
2120 CONFIG_UPDATE_TFTP_MSEC_MAX
2122 These options enable and control the auto-update feature;
2123 for a more detailed description refer to doc/README.update.
2125 - MTD Support (mtdparts command, UBI support)
2128 Adds the MTD device infrastructure from the Linux kernel.
2129 Needed for mtdparts command support.
2131 CONFIG_MTD_PARTITIONS
2133 Adds the MTD partitioning infrastructure from the Linux
2134 kernel. Needed for UBI support.
2140 [so far only for SMDK2400 and TRAB boards]
2142 - Modem support enable:
2143 CONFIG_MODEM_SUPPORT
2145 - RTS/CTS Flow control enable:
2148 - Modem debug support:
2149 CONFIG_MODEM_SUPPORT_DEBUG
2151 Enables debugging stuff (char screen[1024], dbg())
2152 for modem support. Useful only with BDI2000.
2154 - Interrupt support (PPC):
2156 There are common interrupt_init() and timer_interrupt()
2157 for all PPC archs. interrupt_init() calls interrupt_init_cpu()
2158 for CPU specific initialization. interrupt_init_cpu()
2159 should set decrementer_count to appropriate value. If
2160 CPU resets decrementer automatically after interrupt
2161 (ppc4xx) it should set decrementer_count to zero.
2162 timer_interrupt() calls timer_interrupt_cpu() for CPU
2163 specific handling. If board has watchdog / status_led
2164 / other_activity_monitor it works automatically from
2165 general timer_interrupt().
2169 In the target system modem support is enabled when a
2170 specific key (key combination) is pressed during
2171 power-on. Otherwise U-Boot will boot normally
2172 (autoboot). The key_pressed() function is called from
2173 board_init(). Currently key_pressed() is a dummy
2174 function, returning 1 and thus enabling modem
2177 If there are no modem init strings in the
2178 environment, U-Boot proceed to autoboot; the
2179 previous output (banner, info printfs) will be
2182 See also: doc/README.Modem
2185 Configuration Settings:
2186 -----------------------
2188 - CONFIG_SYS_LONGHELP: Defined when you want long help messages included;
2189 undefine this when you're short of memory.
2191 - CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default
2192 width of the commands listed in the 'help' command output.
2194 - CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to
2195 prompt for user input.
2197 - CONFIG_SYS_CBSIZE: Buffer size for input from the Console
2199 - CONFIG_SYS_PBSIZE: Buffer size for Console output
2201 - CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands
2203 - CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to
2204 the application (usually a Linux kernel) when it is
2207 - CONFIG_SYS_BAUDRATE_TABLE:
2208 List of legal baudrate settings for this board.
2210 - CONFIG_SYS_CONSOLE_INFO_QUIET
2211 Suppress display of console information at boot.
2213 - CONFIG_SYS_CONSOLE_IS_IN_ENV
2214 If the board specific function
2215 extern int overwrite_console (void);
2216 returns 1, the stdin, stderr and stdout are switched to the
2217 serial port, else the settings in the environment are used.
2219 - CONFIG_SYS_CONSOLE_OVERWRITE_ROUTINE
2220 Enable the call to overwrite_console().
2222 - CONFIG_SYS_CONSOLE_ENV_OVERWRITE
2223 Enable overwrite of previous console environment settings.
2225 - CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END:
2226 Begin and End addresses of the area used by the
2229 - CONFIG_SYS_ALT_MEMTEST:
2230 Enable an alternate, more extensive memory test.
2232 - CONFIG_SYS_MEMTEST_SCRATCH:
2233 Scratch address used by the alternate memory test
2234 You only need to set this if address zero isn't writeable
2236 - CONFIG_SYS_MEM_TOP_HIDE (PPC only):
2237 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header,
2238 this specified memory area will get subtracted from the top
2239 (end) of RAM and won't get "touched" at all by U-Boot. By
2240 fixing up gd->ram_size the Linux kernel should gets passed
2241 the now "corrected" memory size and won't touch it either.
2242 This should work for arch/ppc and arch/powerpc. Only Linux
2243 board ports in arch/powerpc with bootwrapper support that
2244 recalculate the memory size from the SDRAM controller setup
2245 will have to get fixed in Linux additionally.
2247 This option can be used as a workaround for the 440EPx/GRx
2248 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't
2251 WARNING: Please make sure that this value is a multiple of
2252 the Linux page size (normally 4k). If this is not the case,
2253 then the end address of the Linux memory will be located at a
2254 non page size aligned address and this could cause major
2257 - CONFIG_SYS_TFTP_LOADADDR:
2258 Default load address for network file downloads
2260 - CONFIG_SYS_LOADS_BAUD_CHANGE:
2261 Enable temporary baudrate change while serial download
2263 - CONFIG_SYS_SDRAM_BASE:
2264 Physical start address of SDRAM. _Must_ be 0 here.
2266 - CONFIG_SYS_MBIO_BASE:
2267 Physical start address of Motherboard I/O (if using a
2270 - CONFIG_SYS_FLASH_BASE:
2271 Physical start address of Flash memory.
2273 - CONFIG_SYS_MONITOR_BASE:
2274 Physical start address of boot monitor code (set by
2275 make config files to be same as the text base address
2276 (CONFIG_SYS_TEXT_BASE) used when linking) - same as
2277 CONFIG_SYS_FLASH_BASE when booting from flash.
2279 - CONFIG_SYS_MONITOR_LEN:
2280 Size of memory reserved for monitor code, used to
2281 determine _at_compile_time_ (!) if the environment is
2282 embedded within the U-Boot image, or in a separate
2285 - CONFIG_SYS_MALLOC_LEN:
2286 Size of DRAM reserved for malloc() use.
2288 - CONFIG_SYS_BOOTM_LEN:
2289 Normally compressed uImages are limited to an
2290 uncompressed size of 8 MBytes. If this is not enough,
2291 you can define CONFIG_SYS_BOOTM_LEN in your board config file
2292 to adjust this setting to your needs.
2294 - CONFIG_SYS_BOOTMAPSZ:
2295 Maximum size of memory mapped by the startup code of
2296 the Linux kernel; all data that must be processed by
2297 the Linux kernel (bd_info, boot arguments, FDT blob if
2298 used) must be put below this limit, unless "bootm_low"
2299 enviroment variable is defined and non-zero. In such case
2300 all data for the Linux kernel must be between "bootm_low"
2301 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ.
2303 - CONFIG_SYS_BOOT_RAMDISK_HIGH:
2304 Enable initrd_high functionality. If defined then the
2305 initrd_high feature is enabled and the bootm ramdisk subcommand
2308 - CONFIG_SYS_BOOT_GET_CMDLINE:
2309 Enables allocating and saving kernel cmdline in space between
2310 "bootm_low" and "bootm_low" + BOOTMAPSZ.
2312 - CONFIG_SYS_BOOT_GET_KBD:
2313 Enables allocating and saving a kernel copy of the bd_info in
2314 space between "bootm_low" and "bootm_low" + BOOTMAPSZ.
2316 - CONFIG_SYS_MAX_FLASH_BANKS:
2317 Max number of Flash memory banks
2319 - CONFIG_SYS_MAX_FLASH_SECT:
2320 Max number of sectors on a Flash chip
2322 - CONFIG_SYS_FLASH_ERASE_TOUT:
2323 Timeout for Flash erase operations (in ms)
2325 - CONFIG_SYS_FLASH_WRITE_TOUT:
2326 Timeout for Flash write operations (in ms)
2328 - CONFIG_SYS_FLASH_LOCK_TOUT
2329 Timeout for Flash set sector lock bit operation (in ms)
2331 - CONFIG_SYS_FLASH_UNLOCK_TOUT
2332 Timeout for Flash clear lock bits operation (in ms)
2334 - CONFIG_SYS_FLASH_PROTECTION
2335 If defined, hardware flash sectors protection is used
2336 instead of U-Boot software protection.
2338 - CONFIG_SYS_DIRECT_FLASH_TFTP:
2340 Enable TFTP transfers directly to flash memory;
2341 without this option such a download has to be
2342 performed in two steps: (1) download to RAM, and (2)
2343 copy from RAM to flash.
2345 The two-step approach is usually more reliable, since
2346 you can check if the download worked before you erase
2347 the flash, but in some situations (when system RAM is
2348 too limited to allow for a temporary copy of the
2349 downloaded image) this option may be very useful.
2351 - CONFIG_SYS_FLASH_CFI:
2352 Define if the flash driver uses extra elements in the
2353 common flash structure for storing flash geometry.
2355 - CONFIG_FLASH_CFI_DRIVER
2356 This option also enables the building of the cfi_flash driver
2357 in the drivers directory
2359 - CONFIG_FLASH_CFI_MTD
2360 This option enables the building of the cfi_mtd driver
2361 in the drivers directory. The driver exports CFI flash
2364 - CONFIG_SYS_FLASH_USE_BUFFER_WRITE
2365 Use buffered writes to flash.
2367 - CONFIG_FLASH_SPANSION_S29WS_N
2368 s29ws-n MirrorBit flash has non-standard addresses for buffered
2371 - CONFIG_SYS_FLASH_QUIET_TEST
2372 If this option is defined, the common CFI flash doesn't
2373 print it's warning upon not recognized FLASH banks. This
2374 is useful, if some of the configured banks are only
2375 optionally available.
2377 - CONFIG_FLASH_SHOW_PROGRESS
2378 If defined (must be an integer), print out countdown
2379 digits and dots. Recommended value: 45 (9..1) for 80
2380 column displays, 15 (3..1) for 40 column displays.
2382 - CONFIG_SYS_RX_ETH_BUFFER:
2383 Defines the number of Ethernet receive buffers. On some
2384 Ethernet controllers it is recommended to set this value
2385 to 8 or even higher (EEPRO100 or 405 EMAC), since all
2386 buffers can be full shortly after enabling the interface
2387 on high Ethernet traffic.
2388 Defaults to 4 if not defined.
2390 - CONFIG_ENV_MAX_ENTRIES
2392 Maximum number of entries in the hash table that is used
2393 internally to store the environment settings. The default
2394 setting is supposed to be generous and should work in most
2395 cases. This setting can be used to tune behaviour; see
2396 lib/hashtable.c for details.
2398 The following definitions that deal with the placement and management
2399 of environment data (variable area); in general, we support the
2400 following configurations:
2402 - CONFIG_ENV_IS_IN_FLASH:
2404 Define this if the environment is in flash memory.
2406 a) The environment occupies one whole flash sector, which is
2407 "embedded" in the text segment with the U-Boot code. This
2408 happens usually with "bottom boot sector" or "top boot
2409 sector" type flash chips, which have several smaller
2410 sectors at the start or the end. For instance, such a
2411 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In
2412 such a case you would place the environment in one of the
2413 4 kB sectors - with U-Boot code before and after it. With
2414 "top boot sector" type flash chips, you would put the
2415 environment in one of the last sectors, leaving a gap
2416 between U-Boot and the environment.
2418 - CONFIG_ENV_OFFSET:
2420 Offset of environment data (variable area) to the
2421 beginning of flash memory; for instance, with bottom boot
2422 type flash chips the second sector can be used: the offset
2423 for this sector is given here.
2425 CONFIG_ENV_OFFSET is used relative to CONFIG_SYS_FLASH_BASE.
2429 This is just another way to specify the start address of
2430 the flash sector containing the environment (instead of
2433 - CONFIG_ENV_SECT_SIZE:
2435 Size of the sector containing the environment.
2438 b) Sometimes flash chips have few, equal sized, BIG sectors.
2439 In such a case you don't want to spend a whole sector for
2444 If you use this in combination with CONFIG_ENV_IS_IN_FLASH
2445 and CONFIG_ENV_SECT_SIZE, you can specify to use only a part
2446 of this flash sector for the environment. This saves
2447 memory for the RAM copy of the environment.
2449 It may also save flash memory if you decide to use this
2450 when your environment is "embedded" within U-Boot code,
2451 since then the remainder of the flash sector could be used
2452 for U-Boot code. It should be pointed out that this is
2453 STRONGLY DISCOURAGED from a robustness point of view:
2454 updating the environment in flash makes it always
2455 necessary to erase the WHOLE sector. If something goes
2456 wrong before the contents has been restored from a copy in
2457 RAM, your target system will be dead.
2459 - CONFIG_ENV_ADDR_REDUND
2460 CONFIG_ENV_SIZE_REDUND
2462 These settings describe a second storage area used to hold
2463 a redundant copy of the environment data, so that there is
2464 a valid backup copy in case there is a power failure during
2465 a "saveenv" operation.
2467 BE CAREFUL! Any changes to the flash layout, and some changes to the
2468 source code will make it necessary to adapt <board>/u-boot.lds*
2472 - CONFIG_ENV_IS_IN_NVRAM:
2474 Define this if you have some non-volatile memory device
2475 (NVRAM, battery buffered SRAM) which you want to use for the
2481 These two #defines are used to determine the memory area you
2482 want to use for environment. It is assumed that this memory
2483 can just be read and written to, without any special
2486 BE CAREFUL! The first access to the environment happens quite early
2487 in U-Boot initalization (when we try to get the setting of for the
2488 console baudrate). You *MUST* have mapped your NVRAM area then, or
2491 Please note that even with NVRAM we still use a copy of the
2492 environment in RAM: we could work on NVRAM directly, but we want to
2493 keep settings there always unmodified except somebody uses "saveenv"
2494 to save the current settings.
2497 - CONFIG_ENV_IS_IN_EEPROM:
2499 Use this if you have an EEPROM or similar serial access
2500 device and a driver for it.
2502 - CONFIG_ENV_OFFSET:
2505 These two #defines specify the offset and size of the
2506 environment area within the total memory of your EEPROM.
2508 - CONFIG_SYS_I2C_EEPROM_ADDR:
2509 If defined, specified the chip address of the EEPROM device.
2510 The default address is zero.
2512 - CONFIG_SYS_EEPROM_PAGE_WRITE_BITS:
2513 If defined, the number of bits used to address bytes in a
2514 single page in the EEPROM device. A 64 byte page, for example
2515 would require six bits.
2517 - CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS:
2518 If defined, the number of milliseconds to delay between
2519 page writes. The default is zero milliseconds.
2521 - CONFIG_SYS_I2C_EEPROM_ADDR_LEN:
2522 The length in bytes of the EEPROM memory array address. Note
2523 that this is NOT the chip address length!
2525 - CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW:
2526 EEPROM chips that implement "address overflow" are ones
2527 like Catalyst 24WC04/08/16 which has 9/10/11 bits of
2528 address and the extra bits end up in the "chip address" bit
2529 slots. This makes a 24WC08 (1Kbyte) chip look like four 256
2532 Note that we consider the length of the address field to
2533 still be one byte because the extra address bits are hidden
2534 in the chip address.
2536 - CONFIG_SYS_EEPROM_SIZE:
2537 The size in bytes of the EEPROM device.
2539 - CONFIG_ENV_EEPROM_IS_ON_I2C
2540 define this, if you have I2C and SPI activated, and your
2541 EEPROM, which holds the environment, is on the I2C bus.
2543 - CONFIG_I2C_ENV_EEPROM_BUS
2544 if you have an Environment on an EEPROM reached over
2545 I2C muxes, you can define here, how to reach this
2546 EEPROM. For example:
2548 #define CONFIG_I2C_ENV_EEPROM_BUS "pca9547:70:d\0"
2550 EEPROM which holds the environment, is reached over
2551 a pca9547 i2c mux with address 0x70, channel 3.
2553 - CONFIG_ENV_IS_IN_DATAFLASH:
2555 Define this if you have a DataFlash memory device which you
2556 want to use for the environment.
2558 - CONFIG_ENV_OFFSET:
2562 These three #defines specify the offset and size of the
2563 environment area within the total memory of your DataFlash placed
2564 at the specified address.
2566 - CONFIG_ENV_IS_IN_NAND:
2568 Define this if you have a NAND device which you want to use
2569 for the environment.
2571 - CONFIG_ENV_OFFSET:
2574 These two #defines specify the offset and size of the environment
2575 area within the first NAND device. CONFIG_ENV_OFFSET must be
2576 aligned to an erase block boundary.
2578 - CONFIG_ENV_OFFSET_REDUND (optional):
2580 This setting describes a second storage area of CONFIG_ENV_SIZE
2581 size used to hold a redundant copy of the environment data, so
2582 that there is a valid backup copy in case there is a power failure
2583 during a "saveenv" operation. CONFIG_ENV_OFFSET_RENDUND must be
2584 aligned to an erase block boundary.
2586 - CONFIG_ENV_RANGE (optional):
2588 Specifies the length of the region in which the environment
2589 can be written. This should be a multiple of the NAND device's
2590 block size. Specifying a range with more erase blocks than
2591 are needed to hold CONFIG_ENV_SIZE allows bad blocks within
2592 the range to be avoided.
2594 - CONFIG_ENV_OFFSET_OOB (optional):
2596 Enables support for dynamically retrieving the offset of the
2597 environment from block zero's out-of-band data. The
2598 "nand env.oob" command can be used to record this offset.
2599 Currently, CONFIG_ENV_OFFSET_REDUND is not supported when
2600 using CONFIG_ENV_OFFSET_OOB.
2602 - CONFIG_NAND_ENV_DST
2604 Defines address in RAM to which the nand_spl code should copy the
2605 environment. If redundant environment is used, it will be copied to
2606 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE.
2608 - CONFIG_SYS_SPI_INIT_OFFSET
2610 Defines offset to the initial SPI buffer area in DPRAM. The
2611 area is used at an early stage (ROM part) if the environment
2612 is configured to reside in the SPI EEPROM: We need a 520 byte
2613 scratch DPRAM area. It is used between the two initialization
2614 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems
2615 to be a good choice since it makes it far enough from the
2616 start of the data area as well as from the stack pointer.
2618 Please note that the environment is read-only until the monitor
2619 has been relocated to RAM and a RAM copy of the environment has been
2620 created; also, when using EEPROM you will have to use getenv_f()
2621 until then to read environment variables.
2623 The environment is protected by a CRC32 checksum. Before the monitor
2624 is relocated into RAM, as a result of a bad CRC you will be working
2625 with the compiled-in default environment - *silently*!!! [This is
2626 necessary, because the first environment variable we need is the
2627 "baudrate" setting for the console - if we have a bad CRC, we don't
2628 have any device yet where we could complain.]
2630 Note: once the monitor has been relocated, then it will complain if
2631 the default environment is used; a new CRC is computed as soon as you
2632 use the "saveenv" command to store a valid environment.
2634 - CONFIG_SYS_FAULT_ECHO_LINK_DOWN:
2635 Echo the inverted Ethernet link state to the fault LED.
2637 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR
2638 also needs to be defined.
2640 - CONFIG_SYS_FAULT_MII_ADDR:
2641 MII address of the PHY to check for the Ethernet link state.
2643 - CONFIG_NS16550_MIN_FUNCTIONS:
2644 Define this if you desire to only have use of the NS16550_init
2645 and NS16550_putc functions for the serial driver located at
2646 drivers/serial/ns16550.c. This option is useful for saving
2647 space for already greatly restricted images, including but not
2648 limited to NAND_SPL configurations.
2650 Low Level (hardware related) configuration options:
2651 ---------------------------------------------------
2653 - CONFIG_SYS_CACHELINE_SIZE:
2654 Cache Line Size of the CPU.
2656 - CONFIG_SYS_DEFAULT_IMMR:
2657 Default address of the IMMR after system reset.
2659 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU,
2660 and RPXsuper) to be able to adjust the position of
2661 the IMMR register after a reset.
2663 - Floppy Disk Support:
2664 CONFIG_SYS_FDC_DRIVE_NUMBER
2666 the default drive number (default value 0)
2668 CONFIG_SYS_ISA_IO_STRIDE
2670 defines the spacing between FDC chipset registers
2673 CONFIG_SYS_ISA_IO_OFFSET
2675 defines the offset of register from address. It
2676 depends on which part of the data bus is connected to
2677 the FDC chipset. (default value 0)
2679 If CONFIG_SYS_ISA_IO_STRIDE CONFIG_SYS_ISA_IO_OFFSET and
2680 CONFIG_SYS_FDC_DRIVE_NUMBER are undefined, they take their
2683 if CONFIG_SYS_FDC_HW_INIT is defined, then the function
2684 fdc_hw_init() is called at the beginning of the FDC
2685 setup. fdc_hw_init() must be provided by the board
2686 source code. It is used to make hardware dependant
2689 - CONFIG_SYS_IMMR: Physical address of the Internal Memory.
2690 DO NOT CHANGE unless you know exactly what you're
2691 doing! (11-4) [MPC8xx/82xx systems only]
2693 - CONFIG_SYS_INIT_RAM_ADDR:
2695 Start address of memory area that can be used for
2696 initial data and stack; please note that this must be
2697 writable memory that is working WITHOUT special
2698 initialization, i. e. you CANNOT use normal RAM which
2699 will become available only after programming the
2700 memory controller and running certain initialization
2703 U-Boot uses the following memory types:
2704 - MPC8xx and MPC8260: IMMR (internal memory of the CPU)
2705 - MPC824X: data cache
2706 - PPC4xx: data cache
2708 - CONFIG_SYS_GBL_DATA_OFFSET:
2710 Offset of the initial data structure in the memory
2711 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually
2712 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial
2713 data is located at the end of the available space
2714 (sometimes written as (CONFIG_SYS_INIT_RAM_SIZE -
2715 CONFIG_SYS_INIT_DATA_SIZE), and the initial stack is just
2716 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR +
2717 CONFIG_SYS_GBL_DATA_OFFSET) downward.
2720 On the MPC824X (or other systems that use the data
2721 cache for initial memory) the address chosen for
2722 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must
2723 point to an otherwise UNUSED address space between
2724 the top of RAM and the start of the PCI space.
2726 - CONFIG_SYS_SIUMCR: SIU Module Configuration (11-6)
2728 - CONFIG_SYS_SYPCR: System Protection Control (11-9)
2730 - CONFIG_SYS_TBSCR: Time Base Status and Control (11-26)
2732 - CONFIG_SYS_PISCR: Periodic Interrupt Status and Control (11-31)
2734 - CONFIG_SYS_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30)
2736 - CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27)
2738 - CONFIG_SYS_OR_TIMING_SDRAM:
2741 - CONFIG_SYS_MAMR_PTA:
2742 periodic timer for refresh
2744 - CONFIG_SYS_DER: Debug Event Register (37-47)
2746 - FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM,
2747 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP,
2748 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM,
2749 CONFIG_SYS_BR1_PRELIM:
2750 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
2752 - SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
2753 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM,
2754 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM:
2755 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
2757 - CONFIG_SYS_MAMR_PTA, CONFIG_SYS_MPTPR_2BK_4K, CONFIG_SYS_MPTPR_1BK_4K, CONFIG_SYS_MPTPR_2BK_8K,
2758 CONFIG_SYS_MPTPR_1BK_8K, CONFIG_SYS_MAMR_8COL, CONFIG_SYS_MAMR_9COL:
2759 Machine Mode Register and Memory Periodic Timer
2760 Prescaler definitions (SDRAM timing)
2762 - CONFIG_SYS_I2C_UCODE_PATCH, CONFIG_SYS_I2C_DPMEM_OFFSET [0x1FC0]:
2763 enable I2C microcode relocation patch (MPC8xx);
2764 define relocation offset in DPRAM [DSP2]
2766 - CONFIG_SYS_SMC_UCODE_PATCH, CONFIG_SYS_SMC_DPMEM_OFFSET [0x1FC0]:
2767 enable SMC microcode relocation patch (MPC8xx);
2768 define relocation offset in DPRAM [SMC1]
2770 - CONFIG_SYS_SPI_UCODE_PATCH, CONFIG_SYS_SPI_DPMEM_OFFSET [0x1FC0]:
2771 enable SPI microcode relocation patch (MPC8xx);
2772 define relocation offset in DPRAM [SCC4]
2774 - CONFIG_SYS_USE_OSCCLK:
2775 Use OSCM clock mode on MBX8xx board. Be careful,
2776 wrong setting might damage your board. Read
2777 doc/README.MBX before setting this variable!
2779 - CONFIG_SYS_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only)
2780 Offset of the bootmode word in DPRAM used by post
2781 (Power On Self Tests). This definition overrides
2782 #define'd default value in commproc.h resp.
2785 - CONFIG_SYS_PCI_SLV_MEM_LOCAL, CONFIG_SYS_PCI_SLV_MEM_BUS, CONFIG_SYS_PICMR0_MASK_ATTRIB,
2786 CONFIG_SYS_PCI_MSTR0_LOCAL, CONFIG_SYS_PCIMSK0_MASK, CONFIG_SYS_PCI_MSTR1_LOCAL,
2787 CONFIG_SYS_PCIMSK1_MASK, CONFIG_SYS_PCI_MSTR_MEM_LOCAL, CONFIG_SYS_PCI_MSTR_MEM_BUS,
2788 CONFIG_SYS_CPU_PCI_MEM_START, CONFIG_SYS_PCI_MSTR_MEM_SIZE, CONFIG_SYS_POCMR0_MASK_ATTRIB,
2789 CONFIG_SYS_PCI_MSTR_MEMIO_LOCAL, CONFIG_SYS_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START,
2790 CONFIG_SYS_PCI_MSTR_MEMIO_SIZE, CONFIG_SYS_POCMR1_MASK_ATTRIB, CONFIG_SYS_PCI_MSTR_IO_LOCAL,
2791 CONFIG_SYS_PCI_MSTR_IO_BUS, CONFIG_SYS_CPU_PCI_IO_START, CONFIG_SYS_PCI_MSTR_IO_SIZE,
2792 CONFIG_SYS_POCMR2_MASK_ATTRIB: (MPC826x only)
2793 Overrides the default PCI memory map in arch/powerpc/cpu/mpc8260/pci.c if set.
2795 - CONFIG_PCI_DISABLE_PCIE:
2796 Disable PCI-Express on systems where it is supported but not
2800 Chip has SRIO or not
2803 Board has SRIO 1 port available
2806 Board has SRIO 2 port available
2808 - CONFIG_SYS_SRIOn_MEM_VIRT:
2809 Virtual Address of SRIO port 'n' memory region
2811 - CONFIG_SYS_SRIOn_MEM_PHYS:
2812 Physical Address of SRIO port 'n' memory region
2814 - CONFIG_SYS_SRIOn_MEM_SIZE:
2815 Size of SRIO port 'n' memory region
2818 Get DDR timing information from an I2C EEPROM. Common
2819 with pluggable memory modules such as SODIMMs
2822 I2C address of the SPD EEPROM
2824 - CONFIG_SYS_SPD_BUS_NUM
2825 If SPD EEPROM is on an I2C bus other than the first
2826 one, specify here. Note that the value must resolve
2827 to something your driver can deal with.
2829 - CONFIG_SYS_83XX_DDR_USES_CS0
2830 Only for 83xx systems. If specified, then DDR should
2831 be configured using CS0 and CS1 instead of CS2 and CS3.
2833 - CONFIG_ETHER_ON_FEC[12]
2834 Define to enable FEC[12] on a 8xx series processor.
2836 - CONFIG_FEC[12]_PHY
2837 Define to the hardcoded PHY address which corresponds
2838 to the given FEC; i. e.
2839 #define CONFIG_FEC1_PHY 4
2840 means that the PHY with address 4 is connected to FEC1
2842 When set to -1, means to probe for first available.
2844 - CONFIG_FEC[12]_PHY_NORXERR
2845 The PHY does not have a RXERR line (RMII only).
2846 (so program the FEC to ignore it).
2849 Enable RMII mode for all FECs.
2850 Note that this is a global option, we can't
2851 have one FEC in standard MII mode and another in RMII mode.
2853 - CONFIG_CRC32_VERIFY
2854 Add a verify option to the crc32 command.
2857 => crc32 -v <address> <count> <crc32>
2859 Where address/count indicate a memory area
2860 and crc32 is the correct crc32 which the
2864 Add the "loopw" memory command. This only takes effect if
2865 the memory commands are activated globally (CONFIG_CMD_MEM).
2868 Add the "mdc" and "mwc" memory commands. These are cyclic
2873 This command will print 4 bytes (10,11,12,13) each 500 ms.
2875 => mwc.l 100 12345678 10
2876 This command will write 12345678 to address 100 all 10 ms.
2878 This only takes effect if the memory commands are activated
2879 globally (CONFIG_CMD_MEM).
2881 - CONFIG_SKIP_LOWLEVEL_INIT
2882 [ARM only] If this variable is defined, then certain
2883 low level initializations (like setting up the memory
2884 controller) are omitted and/or U-Boot does not
2885 relocate itself into RAM.
2887 Normally this variable MUST NOT be defined. The only
2888 exception is when U-Boot is loaded (to RAM) by some
2889 other boot loader or by a debugger which performs
2890 these initializations itself.
2893 Modifies the behaviour of start.S when compiling a loader
2894 that is executed before the actual U-Boot. E.g. when
2895 compiling a NAND SPL.
2897 Building the Software:
2898 ======================
2900 Building U-Boot has been tested in several native build environments
2901 and in many different cross environments. Of course we cannot support
2902 all possibly existing versions of cross development tools in all
2903 (potentially obsolete) versions. In case of tool chain problems we
2904 recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK)
2905 which is extensively used to build and test U-Boot.
2907 If you are not using a native environment, it is assumed that you
2908 have GNU cross compiling tools available in your path. In this case,
2909 you must set the environment variable CROSS_COMPILE in your shell.
2910 Note that no changes to the Makefile or any other source files are
2911 necessary. For example using the ELDK on a 4xx CPU, please enter:
2913 $ CROSS_COMPILE=ppc_4xx-
2914 $ export CROSS_COMPILE
2916 Note: If you wish to generate Windows versions of the utilities in
2917 the tools directory you can use the MinGW toolchain
2918 (http://www.mingw.org). Set your HOST tools to the MinGW
2919 toolchain and execute 'make tools'. For example:
2921 $ make HOSTCC=i586-mingw32msvc-gcc HOSTSTRIP=i586-mingw32msvc-strip tools
2923 Binaries such as tools/mkimage.exe will be created which can
2924 be executed on computers running Windows.
2926 U-Boot is intended to be simple to build. After installing the
2927 sources you must configure U-Boot for one specific board type. This
2932 where "NAME_config" is the name of one of the existing configu-
2933 rations; see the main Makefile for supported names.
2935 Note: for some board special configuration names may exist; check if
2936 additional information is available from the board vendor; for
2937 instance, the TQM823L systems are available without (standard)
2938 or with LCD support. You can select such additional "features"
2939 when choosing the configuration, i. e.
2942 - will configure for a plain TQM823L, i. e. no LCD support
2944 make TQM823L_LCD_config
2945 - will configure for a TQM823L with U-Boot console on LCD
2950 Finally, type "make all", and you should get some working U-Boot
2951 images ready for download to / installation on your system:
2953 - "u-boot.bin" is a raw binary image
2954 - "u-boot" is an image in ELF binary format
2955 - "u-boot.srec" is in Motorola S-Record format
2957 By default the build is performed locally and the objects are saved
2958 in the source directory. One of the two methods can be used to change
2959 this behavior and build U-Boot to some external directory:
2961 1. Add O= to the make command line invocations:
2963 make O=/tmp/build distclean
2964 make O=/tmp/build NAME_config
2965 make O=/tmp/build all
2967 2. Set environment variable BUILD_DIR to point to the desired location:
2969 export BUILD_DIR=/tmp/build
2974 Note that the command line "O=" setting overrides the BUILD_DIR environment
2978 Please be aware that the Makefiles assume you are using GNU make, so
2979 for instance on NetBSD you might need to use "gmake" instead of
2983 If the system board that you have is not listed, then you will need
2984 to port U-Boot to your hardware platform. To do this, follow these
2987 1. Add a new configuration option for your board to the toplevel
2988 "Makefile" and to the "MAKEALL" script, using the existing
2989 entries as examples. Note that here and at many other places
2990 boards and other names are listed in alphabetical sort order. Please
2992 2. Create a new directory to hold your board specific code. Add any
2993 files you need. In your board directory, you will need at least
2994 the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds".
2995 3. Create a new configuration file "include/configs/<board>.h" for
2997 3. If you're porting U-Boot to a new CPU, then also create a new
2998 directory to hold your CPU specific code. Add any files you need.
2999 4. Run "make <board>_config" with your new name.
3000 5. Type "make", and you should get a working "u-boot.srec" file
3001 to be installed on your target system.
3002 6. Debug and solve any problems that might arise.
3003 [Of course, this last step is much harder than it sounds.]
3006 Testing of U-Boot Modifications, Ports to New Hardware, etc.:
3007 ==============================================================
3009 If you have modified U-Boot sources (for instance added a new board
3010 or support for new devices, a new CPU, etc.) you are expected to
3011 provide feedback to the other developers. The feedback normally takes
3012 the form of a "patch", i. e. a context diff against a certain (latest
3013 official or latest in the git repository) version of U-Boot sources.
3015 But before you submit such a patch, please verify that your modifi-
3016 cation did not break existing code. At least make sure that *ALL* of
3017 the supported boards compile WITHOUT ANY compiler warnings. To do so,
3018 just run the "MAKEALL" script, which will configure and build U-Boot
3019 for ALL supported system. Be warned, this will take a while. You can
3020 select which (cross) compiler to use by passing a `CROSS_COMPILE'
3021 environment variable to the script, i. e. to use the ELDK cross tools
3024 CROSS_COMPILE=ppc_8xx- MAKEALL
3026 or to build on a native PowerPC system you can type
3028 CROSS_COMPILE=' ' MAKEALL
3030 When using the MAKEALL script, the default behaviour is to build
3031 U-Boot in the source directory. This location can be changed by
3032 setting the BUILD_DIR environment variable. Also, for each target
3033 built, the MAKEALL script saves two log files (<target>.ERR and
3034 <target>.MAKEALL) in the <source dir>/LOG directory. This default
3035 location can be changed by setting the MAKEALL_LOGDIR environment
3036 variable. For example:
3038 export BUILD_DIR=/tmp/build
3039 export MAKEALL_LOGDIR=/tmp/log
3040 CROSS_COMPILE=ppc_8xx- MAKEALL
3042 With the above settings build objects are saved in the /tmp/build,
3043 log files are saved in the /tmp/log and the source tree remains clean
3044 during the whole build process.
3047 See also "U-Boot Porting Guide" below.
3050 Monitor Commands - Overview:
3051 ============================
3053 go - start application at address 'addr'
3054 run - run commands in an environment variable
3055 bootm - boot application image from memory
3056 bootp - boot image via network using BootP/TFTP protocol
3057 tftpboot- boot image via network using TFTP protocol
3058 and env variables "ipaddr" and "serverip"
3059 (and eventually "gatewayip")
3060 rarpboot- boot image via network using RARP/TFTP protocol
3061 diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
3062 loads - load S-Record file over serial line
3063 loadb - load binary file over serial line (kermit mode)
3065 mm - memory modify (auto-incrementing)
3066 nm - memory modify (constant address)
3067 mw - memory write (fill)
3069 cmp - memory compare
3070 crc32 - checksum calculation
3071 i2c - I2C sub-system
3072 sspi - SPI utility commands
3073 base - print or set address offset
3074 printenv- print environment variables
3075 setenv - set environment variables
3076 saveenv - save environment variables to persistent storage
3077 protect - enable or disable FLASH write protection
3078 erase - erase FLASH memory
3079 flinfo - print FLASH memory information
3080 bdinfo - print Board Info structure
3081 iminfo - print header information for application image
3082 coninfo - print console devices and informations
3083 ide - IDE sub-system
3084 loop - infinite loop on address range
3085 loopw - infinite write loop on address range
3086 mtest - simple RAM test
3087 icache - enable or disable instruction cache
3088 dcache - enable or disable data cache
3089 reset - Perform RESET of the CPU
3090 echo - echo args to console
3091 version - print monitor version
3092 help - print online help
3093 ? - alias for 'help'
3096 Monitor Commands - Detailed Description:
3097 ========================================
3101 For now: just type "help <command>".
3104 Environment Variables:
3105 ======================
3107 U-Boot supports user configuration using Environment Variables which
3108 can be made persistent by saving to Flash memory.
3110 Environment Variables are set using "setenv", printed using
3111 "printenv", and saved to Flash using "saveenv". Using "setenv"
3112 without a value can be used to delete a variable from the
3113 environment. As long as you don't save the environment you are
3114 working with an in-memory copy. In case the Flash area containing the
3115 environment is erased by accident, a default environment is provided.
3117 Some configuration options can be set using Environment Variables.
3119 List of environment variables (most likely not complete):
3121 baudrate - see CONFIG_BAUDRATE
3123 bootdelay - see CONFIG_BOOTDELAY
3125 bootcmd - see CONFIG_BOOTCOMMAND
3127 bootargs - Boot arguments when booting an RTOS image
3129 bootfile - Name of the image to load with TFTP
3131 bootm_low - Memory range available for image processing in the bootm
3132 command can be restricted. This variable is given as
3133 a hexadecimal number and defines lowest address allowed
3134 for use by the bootm command. See also "bootm_size"
3135 environment variable. Address defined by "bootm_low" is
3136 also the base of the initial memory mapping for the Linux
3137 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ.
3139 bootm_size - Memory range available for image processing in the bootm
3140 command can be restricted. This variable is given as
3141 a hexadecimal number and defines the size of the region
3142 allowed for use by the bootm command. See also "bootm_low"
3143 environment variable.
3145 updatefile - Location of the software update file on a TFTP server, used
3146 by the automatic software update feature. Please refer to
3147 documentation in doc/README.update for more details.
3149 autoload - if set to "no" (any string beginning with 'n'),
3150 "bootp" will just load perform a lookup of the
3151 configuration from the BOOTP server, but not try to
3152 load any image using TFTP
3154 autostart - if set to "yes", an image loaded using the "bootp",
3155 "rarpboot", "tftpboot" or "diskboot" commands will
3156 be automatically started (by internally calling
3159 If set to "no", a standalone image passed to the
3160 "bootm" command will be copied to the load address
3161 (and eventually uncompressed), but NOT be started.
3162 This can be used to load and uncompress arbitrary
3165 i2cfast - (PPC405GP|PPC405EP only)
3166 if set to 'y' configures Linux I2C driver for fast
3167 mode (400kHZ). This environment variable is used in
3168 initialization code. So, for changes to be effective
3169 it must be saved and board must be reset.
3171 initrd_high - restrict positioning of initrd images:
3172 If this variable is not set, initrd images will be
3173 copied to the highest possible address in RAM; this
3174 is usually what you want since it allows for
3175 maximum initrd size. If for some reason you want to
3176 make sure that the initrd image is loaded below the
3177 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment
3178 variable to a value of "no" or "off" or "0".
3179 Alternatively, you can set it to a maximum upper
3180 address to use (U-Boot will still check that it
3181 does not overwrite the U-Boot stack and data).
3183 For instance, when you have a system with 16 MB
3184 RAM, and want to reserve 4 MB from use by Linux,
3185 you can do this by adding "mem=12M" to the value of
3186 the "bootargs" variable. However, now you must make
3187 sure that the initrd image is placed in the first
3188 12 MB as well - this can be done with
3190 setenv initrd_high 00c00000
3192 If you set initrd_high to 0xFFFFFFFF, this is an
3193 indication to U-Boot that all addresses are legal
3194 for the Linux kernel, including addresses in flash
3195 memory. In this case U-Boot will NOT COPY the
3196 ramdisk at all. This may be useful to reduce the
3197 boot time on your system, but requires that this
3198 feature is supported by your Linux kernel.
3200 ipaddr - IP address; needed for tftpboot command
3202 loadaddr - Default load address for commands like "bootp",
3203 "rarpboot", "tftpboot", "loadb" or "diskboot"
3205 loads_echo - see CONFIG_LOADS_ECHO
3207 serverip - TFTP server IP address; needed for tftpboot command
3209 bootretry - see CONFIG_BOOT_RETRY_TIME
3211 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
3213 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
3215 ethprime - When CONFIG_NET_MULTI is enabled controls which
3216 interface is used first.
3218 ethact - When CONFIG_NET_MULTI is enabled controls which
3219 interface is currently active. For example you
3220 can do the following
3222 => setenv ethact FEC
3223 => ping 192.168.0.1 # traffic sent on FEC
3224 => setenv ethact SCC
3225 => ping 10.0.0.1 # traffic sent on SCC
3227 ethrotate - When set to "no" U-Boot does not go through all
3228 available network interfaces.
3229 It just stays at the currently selected interface.
3231 netretry - When set to "no" each network operation will
3232 either succeed or fail without retrying.
3233 When set to "once" the network operation will
3234 fail when all the available network interfaces
3235 are tried once without success.
3236 Useful on scripts which control the retry operation
3239 npe_ucode - set load address for the NPE microcode
3241 tftpsrcport - If this is set, the value is used for TFTP's
3244 tftpdstport - If this is set, the value is used for TFTP's UDP
3245 destination port instead of the Well Know Port 69.
3247 tftpblocksize - Block size to use for TFTP transfers; if not set,
3248 we use the TFTP server's default block size
3250 tftptimeout - Retransmission timeout for TFTP packets (in milli-
3251 seconds, minimum value is 1000 = 1 second). Defines
3252 when a packet is considered to be lost so it has to
3253 be retransmitted. The default is 5000 = 5 seconds.
3254 Lowering this value may make downloads succeed
3255 faster in networks with high packet loss rates or
3256 with unreliable TFTP servers.
3258 vlan - When set to a value < 4095 the traffic over
3259 Ethernet is encapsulated/received over 802.1q
3262 The following environment variables may be used and automatically
3263 updated by the network boot commands ("bootp" and "rarpboot"),
3264 depending the information provided by your boot server:
3266 bootfile - see above
3267 dnsip - IP address of your Domain Name Server
3268 dnsip2 - IP address of your secondary Domain Name Server
3269 gatewayip - IP address of the Gateway (Router) to use
3270 hostname - Target hostname
3272 netmask - Subnet Mask
3273 rootpath - Pathname of the root filesystem on the NFS server
3274 serverip - see above
3277 There are two special Environment Variables:
3279 serial# - contains hardware identification information such
3280 as type string and/or serial number
3281 ethaddr - Ethernet address
3283 These variables can be set only once (usually during manufacturing of
3284 the board). U-Boot refuses to delete or overwrite these variables
3285 once they have been set once.
3288 Further special Environment Variables:
3290 ver - Contains the U-Boot version string as printed
3291 with the "version" command. This variable is
3292 readonly (see CONFIG_VERSION_VARIABLE).
3295 Please note that changes to some configuration parameters may take
3296 only effect after the next boot (yes, that's just like Windoze :-).
3299 Command Line Parsing:
3300 =====================
3302 There are two different command line parsers available with U-Boot:
3303 the old "simple" one, and the much more powerful "hush" shell:
3305 Old, simple command line parser:
3306 --------------------------------
3308 - supports environment variables (through setenv / saveenv commands)
3309 - several commands on one line, separated by ';'
3310 - variable substitution using "... ${name} ..." syntax
3311 - special characters ('$', ';') can be escaped by prefixing with '\',
3313 setenv bootcmd bootm \${address}
3314 - You can also escape text by enclosing in single apostrophes, for example:
3315 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
3320 - similar to Bourne shell, with control structures like
3321 if...then...else...fi, for...do...done; while...do...done,
3322 until...do...done, ...
3323 - supports environment ("global") variables (through setenv / saveenv
3324 commands) and local shell variables (through standard shell syntax
3325 "name=value"); only environment variables can be used with "run"
3331 (1) If a command line (or an environment variable executed by a "run"
3332 command) contains several commands separated by semicolon, and
3333 one of these commands fails, then the remaining commands will be
3336 (2) If you execute several variables with one call to run (i. e.
3337 calling run with a list of variables as arguments), any failing
3338 command will cause "run" to terminate, i. e. the remaining
3339 variables are not executed.
3341 Note for Redundant Ethernet Interfaces:
3342 =======================================
3344 Some boards come with redundant Ethernet interfaces; U-Boot supports
3345 such configurations and is capable of automatic selection of a
3346 "working" interface when needed. MAC assignment works as follows:
3348 Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
3349 MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
3350 "eth1addr" (=>eth1), "eth2addr", ...
3352 If the network interface stores some valid MAC address (for instance
3353 in SROM), this is used as default address if there is NO correspon-
3354 ding setting in the environment; if the corresponding environment
3355 variable is set, this overrides the settings in the card; that means:
3357 o If the SROM has a valid MAC address, and there is no address in the
3358 environment, the SROM's address is used.
3360 o If there is no valid address in the SROM, and a definition in the
3361 environment exists, then the value from the environment variable is
3364 o If both the SROM and the environment contain a MAC address, and
3365 both addresses are the same, this MAC address is used.
3367 o If both the SROM and the environment contain a MAC address, and the
3368 addresses differ, the value from the environment is used and a
3371 o If neither SROM nor the environment contain a MAC address, an error
3374 If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses
3375 will be programmed into hardware as part of the initialization process. This
3376 may be skipped by setting the appropriate 'ethmacskip' environment variable.
3377 The naming convention is as follows:
3378 "ethmacskip" (=>eth0), "eth1macskip" (=>eth1) etc.
3383 U-Boot is capable of booting (and performing other auxiliary operations on)
3384 images in two formats:
3386 New uImage format (FIT)
3387 -----------------------
3389 Flexible and powerful format based on Flattened Image Tree -- FIT (similar
3390 to Flattened Device Tree). It allows the use of images with multiple
3391 components (several kernels, ramdisks, etc.), with contents protected by
3392 SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory.
3398 Old image format is based on binary files which can be basically anything,
3399 preceded by a special header; see the definitions in include/image.h for
3400 details; basically, the header defines the following image properties:
3402 * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
3403 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
3404 LynxOS, pSOS, QNX, RTEMS, INTEGRITY;
3405 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS,
3407 * Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86,
3408 IA64, MIPS, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
3409 Currently supported: ARM, AVR32, Intel x86, MIPS, Nios II, PowerPC).
3410 * Compression Type (uncompressed, gzip, bzip2)
3416 The header is marked by a special Magic Number, and both the header
3417 and the data portions of the image are secured against corruption by
3424 Although U-Boot should support any OS or standalone application
3425 easily, the main focus has always been on Linux during the design of
3428 U-Boot includes many features that so far have been part of some
3429 special "boot loader" code within the Linux kernel. Also, any
3430 "initrd" images to be used are no longer part of one big Linux image;
3431 instead, kernel and "initrd" are separate images. This implementation
3432 serves several purposes:
3434 - the same features can be used for other OS or standalone
3435 applications (for instance: using compressed images to reduce the
3436 Flash memory footprint)
3438 - it becomes much easier to port new Linux kernel versions because
3439 lots of low-level, hardware dependent stuff are done by U-Boot
3441 - the same Linux kernel image can now be used with different "initrd"
3442 images; of course this also means that different kernel images can
3443 be run with the same "initrd". This makes testing easier (you don't
3444 have to build a new "zImage.initrd" Linux image when you just
3445 change a file in your "initrd"). Also, a field-upgrade of the
3446 software is easier now.
3452 Porting Linux to U-Boot based systems:
3453 ---------------------------------------
3455 U-Boot cannot save you from doing all the necessary modifications to
3456 configure the Linux device drivers for use with your target hardware
3457 (no, we don't intend to provide a full virtual machine interface to
3460 But now you can ignore ALL boot loader code (in arch/powerpc/mbxboot).
3462 Just make sure your machine specific header file (for instance
3463 include/asm-ppc/tqm8xx.h) includes the same definition of the Board
3464 Information structure as we define in include/asm-<arch>/u-boot.h,
3465 and make sure that your definition of IMAP_ADDR uses the same value
3466 as your U-Boot configuration in CONFIG_SYS_IMMR.
3469 Configuring the Linux kernel:
3470 -----------------------------
3472 No specific requirements for U-Boot. Make sure you have some root
3473 device (initial ramdisk, NFS) for your target system.
3476 Building a Linux Image:
3477 -----------------------
3479 With U-Boot, "normal" build targets like "zImage" or "bzImage" are
3480 not used. If you use recent kernel source, a new build target
3481 "uImage" will exist which automatically builds an image usable by
3482 U-Boot. Most older kernels also have support for a "pImage" target,
3483 which was introduced for our predecessor project PPCBoot and uses a
3484 100% compatible format.
3493 The "uImage" build target uses a special tool (in 'tools/mkimage') to
3494 encapsulate a compressed Linux kernel image with header information,
3495 CRC32 checksum etc. for use with U-Boot. This is what we are doing:
3497 * build a standard "vmlinux" kernel image (in ELF binary format):
3499 * convert the kernel into a raw binary image:
3501 ${CROSS_COMPILE}-objcopy -O binary \
3502 -R .note -R .comment \
3503 -S vmlinux linux.bin
3505 * compress the binary image:
3509 * package compressed binary image for U-Boot:
3511 mkimage -A ppc -O linux -T kernel -C gzip \
3512 -a 0 -e 0 -n "Linux Kernel Image" \
3513 -d linux.bin.gz uImage
3516 The "mkimage" tool can also be used to create ramdisk images for use
3517 with U-Boot, either separated from the Linux kernel image, or
3518 combined into one file. "mkimage" encapsulates the images with a 64
3519 byte header containing information about target architecture,
3520 operating system, image type, compression method, entry points, time
3521 stamp, CRC32 checksums, etc.
3523 "mkimage" can be called in two ways: to verify existing images and
3524 print the header information, or to build new images.
3526 In the first form (with "-l" option) mkimage lists the information
3527 contained in the header of an existing U-Boot image; this includes
3528 checksum verification:
3530 tools/mkimage -l image
3531 -l ==> list image header information
3533 The second form (with "-d" option) is used to build a U-Boot image
3534 from a "data file" which is used as image payload:
3536 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
3537 -n name -d data_file image
3538 -A ==> set architecture to 'arch'
3539 -O ==> set operating system to 'os'
3540 -T ==> set image type to 'type'
3541 -C ==> set compression type 'comp'
3542 -a ==> set load address to 'addr' (hex)
3543 -e ==> set entry point to 'ep' (hex)
3544 -n ==> set image name to 'name'
3545 -d ==> use image data from 'datafile'
3547 Right now, all Linux kernels for PowerPC systems use the same load
3548 address (0x00000000), but the entry point address depends on the
3551 - 2.2.x kernels have the entry point at 0x0000000C,
3552 - 2.3.x and later kernels have the entry point at 0x00000000.
3554 So a typical call to build a U-Boot image would read:
3556 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
3557 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
3558 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz \
3559 > examples/uImage.TQM850L
3560 Image Name: 2.4.4 kernel for TQM850L
3561 Created: Wed Jul 19 02:34:59 2000
3562 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3563 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
3564 Load Address: 0x00000000
3565 Entry Point: 0x00000000
3567 To verify the contents of the image (or check for corruption):
3569 -> tools/mkimage -l examples/uImage.TQM850L
3570 Image Name: 2.4.4 kernel for TQM850L
3571 Created: Wed Jul 19 02:34:59 2000
3572 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3573 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
3574 Load Address: 0x00000000
3575 Entry Point: 0x00000000
3577 NOTE: for embedded systems where boot time is critical you can trade
3578 speed for memory and install an UNCOMPRESSED image instead: this
3579 needs more space in Flash, but boots much faster since it does not
3580 need to be uncompressed:
3582 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz
3583 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
3584 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
3585 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux \
3586 > examples/uImage.TQM850L-uncompressed
3587 Image Name: 2.4.4 kernel for TQM850L
3588 Created: Wed Jul 19 02:34:59 2000
3589 Image Type: PowerPC Linux Kernel Image (uncompressed)
3590 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
3591 Load Address: 0x00000000
3592 Entry Point: 0x00000000
3595 Similar you can build U-Boot images from a 'ramdisk.image.gz' file
3596 when your kernel is intended to use an initial ramdisk:
3598 -> tools/mkimage -n 'Simple Ramdisk Image' \
3599 > -A ppc -O linux -T ramdisk -C gzip \
3600 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
3601 Image Name: Simple Ramdisk Image
3602 Created: Wed Jan 12 14:01:50 2000
3603 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
3604 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
3605 Load Address: 0x00000000
3606 Entry Point: 0x00000000
3609 Installing a Linux Image:
3610 -------------------------
3612 To downloading a U-Boot image over the serial (console) interface,
3613 you must convert the image to S-Record format:
3615 objcopy -I binary -O srec examples/image examples/image.srec
3617 The 'objcopy' does not understand the information in the U-Boot
3618 image header, so the resulting S-Record file will be relative to
3619 address 0x00000000. To load it to a given address, you need to
3620 specify the target address as 'offset' parameter with the 'loads'
3623 Example: install the image to address 0x40100000 (which on the
3624 TQM8xxL is in the first Flash bank):
3626 => erase 40100000 401FFFFF
3632 ## Ready for S-Record download ...
3633 ~>examples/image.srec
3634 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
3636 15989 15990 15991 15992
3637 [file transfer complete]
3639 ## Start Addr = 0x00000000
3642 You can check the success of the download using the 'iminfo' command;
3643 this includes a checksum verification so you can be sure no data
3644 corruption happened:
3648 ## Checking Image at 40100000 ...
3649 Image Name: 2.2.13 for initrd on TQM850L
3650 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3651 Data Size: 335725 Bytes = 327 kB = 0 MB
3652 Load Address: 00000000
3653 Entry Point: 0000000c
3654 Verifying Checksum ... OK
3660 The "bootm" command is used to boot an application that is stored in
3661 memory (RAM or Flash). In case of a Linux kernel image, the contents
3662 of the "bootargs" environment variable is passed to the kernel as
3663 parameters. You can check and modify this variable using the
3664 "printenv" and "setenv" commands:
3667 => printenv bootargs
3668 bootargs=root=/dev/ram
3670 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
3672 => printenv bootargs
3673 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
3676 ## Booting Linux kernel at 40020000 ...
3677 Image Name: 2.2.13 for NFS on TQM850L
3678 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3679 Data Size: 381681 Bytes = 372 kB = 0 MB
3680 Load Address: 00000000
3681 Entry Point: 0000000c
3682 Verifying Checksum ... OK
3683 Uncompressing Kernel Image ... OK
3684 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
3685 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
3686 time_init: decrementer frequency = 187500000/60
3687 Calibrating delay loop... 49.77 BogoMIPS
3688 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
3691 If you want to boot a Linux kernel with initial RAM disk, you pass
3692 the memory addresses of both the kernel and the initrd image (PPBCOOT
3693 format!) to the "bootm" command:
3695 => imi 40100000 40200000
3697 ## Checking Image at 40100000 ...
3698 Image Name: 2.2.13 for initrd on TQM850L
3699 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3700 Data Size: 335725 Bytes = 327 kB = 0 MB
3701 Load Address: 00000000
3702 Entry Point: 0000000c
3703 Verifying Checksum ... OK
3705 ## Checking Image at 40200000 ...
3706 Image Name: Simple Ramdisk Image
3707 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
3708 Data Size: 566530 Bytes = 553 kB = 0 MB
3709 Load Address: 00000000
3710 Entry Point: 00000000
3711 Verifying Checksum ... OK
3713 => bootm 40100000 40200000
3714 ## Booting Linux kernel at 40100000 ...
3715 Image Name: 2.2.13 for initrd on TQM850L
3716 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3717 Data Size: 335725 Bytes = 327 kB = 0 MB
3718 Load Address: 00000000
3719 Entry Point: 0000000c
3720 Verifying Checksum ... OK
3721 Uncompressing Kernel Image ... OK
3722 ## Loading RAMDisk Image at 40200000 ...
3723 Image Name: Simple Ramdisk Image
3724 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
3725 Data Size: 566530 Bytes = 553 kB = 0 MB
3726 Load Address: 00000000
3727 Entry Point: 00000000
3728 Verifying Checksum ... OK
3729 Loading Ramdisk ... OK
3730 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
3731 Boot arguments: root=/dev/ram
3732 time_init: decrementer frequency = 187500000/60
3733 Calibrating delay loop... 49.77 BogoMIPS
3735 RAMDISK: Compressed image found at block 0
3736 VFS: Mounted root (ext2 filesystem).
3740 Boot Linux and pass a flat device tree:
3743 First, U-Boot must be compiled with the appropriate defines. See the section
3744 titled "Linux Kernel Interface" above for a more in depth explanation. The
3745 following is an example of how to start a kernel and pass an updated
3751 oft=oftrees/mpc8540ads.dtb
3752 => tftp $oftaddr $oft
3753 Speed: 1000, full duplex
3755 TFTP from server 192.168.1.1; our IP address is 192.168.1.101
3756 Filename 'oftrees/mpc8540ads.dtb'.
3757 Load address: 0x300000
3760 Bytes transferred = 4106 (100a hex)
3761 => tftp $loadaddr $bootfile
3762 Speed: 1000, full duplex
3764 TFTP from server 192.168.1.1; our IP address is 192.168.1.2
3766 Load address: 0x200000
3767 Loading:############
3769 Bytes transferred = 1029407 (fb51f hex)
3774 => bootm $loadaddr - $oftaddr
3775 ## Booting image at 00200000 ...
3776 Image Name: Linux-2.6.17-dirty
3777 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3778 Data Size: 1029343 Bytes = 1005.2 kB
3779 Load Address: 00000000
3780 Entry Point: 00000000
3781 Verifying Checksum ... OK
3782 Uncompressing Kernel Image ... OK
3783 Booting using flat device tree at 0x300000
3784 Using MPC85xx ADS machine description
3785 Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb
3789 More About U-Boot Image Types:
3790 ------------------------------
3792 U-Boot supports the following image types:
3794 "Standalone Programs" are directly runnable in the environment
3795 provided by U-Boot; it is expected that (if they behave
3796 well) you can continue to work in U-Boot after return from
3797 the Standalone Program.
3798 "OS Kernel Images" are usually images of some Embedded OS which
3799 will take over control completely. Usually these programs
3800 will install their own set of exception handlers, device
3801 drivers, set up the MMU, etc. - this means, that you cannot
3802 expect to re-enter U-Boot except by resetting the CPU.
3803 "RAMDisk Images" are more or less just data blocks, and their
3804 parameters (address, size) are passed to an OS kernel that is
3806 "Multi-File Images" contain several images, typically an OS
3807 (Linux) kernel image and one or more data images like
3808 RAMDisks. This construct is useful for instance when you want
3809 to boot over the network using BOOTP etc., where the boot
3810 server provides just a single image file, but you want to get
3811 for instance an OS kernel and a RAMDisk image.
3813 "Multi-File Images" start with a list of image sizes, each
3814 image size (in bytes) specified by an "uint32_t" in network
3815 byte order. This list is terminated by an "(uint32_t)0".
3816 Immediately after the terminating 0 follow the images, one by
3817 one, all aligned on "uint32_t" boundaries (size rounded up to
3818 a multiple of 4 bytes).
3820 "Firmware Images" are binary images containing firmware (like
3821 U-Boot or FPGA images) which usually will be programmed to
3824 "Script files" are command sequences that will be executed by
3825 U-Boot's command interpreter; this feature is especially
3826 useful when you configure U-Boot to use a real shell (hush)
3827 as command interpreter.
3833 One of the features of U-Boot is that you can dynamically load and
3834 run "standalone" applications, which can use some resources of
3835 U-Boot like console I/O functions or interrupt services.
3837 Two simple examples are included with the sources:
3842 'examples/hello_world.c' contains a small "Hello World" Demo
3843 application; it is automatically compiled when you build U-Boot.
3844 It's configured to run at address 0x00040004, so you can play with it
3848 ## Ready for S-Record download ...
3849 ~>examples/hello_world.srec
3850 1 2 3 4 5 6 7 8 9 10 11 ...
3851 [file transfer complete]
3853 ## Start Addr = 0x00040004
3855 => go 40004 Hello World! This is a test.
3856 ## Starting application at 0x00040004 ...
3867 Hit any key to exit ...
3869 ## Application terminated, rc = 0x0
3871 Another example, which demonstrates how to register a CPM interrupt
3872 handler with the U-Boot code, can be found in 'examples/timer.c'.
3873 Here, a CPM timer is set up to generate an interrupt every second.
3874 The interrupt service routine is trivial, just printing a '.'
3875 character, but this is just a demo program. The application can be
3876 controlled by the following keys:
3878 ? - print current values og the CPM Timer registers
3879 b - enable interrupts and start timer
3880 e - stop timer and disable interrupts
3881 q - quit application
3884 ## Ready for S-Record download ...
3885 ~>examples/timer.srec
3886 1 2 3 4 5 6 7 8 9 10 11 ...
3887 [file transfer complete]
3889 ## Start Addr = 0x00040004
3892 ## Starting application at 0x00040004 ...
3895 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
3898 [q, b, e, ?] Set interval 1000000 us
3901 [q, b, e, ?] ........
3902 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
3905 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
3908 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
3911 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
3913 [q, b, e, ?] ...Stopping timer
3915 [q, b, e, ?] ## Application terminated, rc = 0x0
3921 Over time, many people have reported problems when trying to use the
3922 "minicom" terminal emulation program for serial download. I (wd)
3923 consider minicom to be broken, and recommend not to use it. Under
3924 Unix, I recommend to use C-Kermit for general purpose use (and
3925 especially for kermit binary protocol download ("loadb" command), and
3926 use "cu" for S-Record download ("loads" command).
3928 Nevertheless, if you absolutely want to use it try adding this
3929 configuration to your "File transfer protocols" section:
3931 Name Program Name U/D FullScr IO-Red. Multi
3932 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
3933 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
3939 Starting at version 0.9.2, U-Boot supports NetBSD both as host
3940 (build U-Boot) and target system (boots NetBSD/mpc8xx).
3942 Building requires a cross environment; it is known to work on
3943 NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
3944 need gmake since the Makefiles are not compatible with BSD make).
3945 Note that the cross-powerpc package does not install include files;
3946 attempting to build U-Boot will fail because <machine/ansi.h> is
3947 missing. This file has to be installed and patched manually:
3949 # cd /usr/pkg/cross/powerpc-netbsd/include
3951 # ln -s powerpc machine
3952 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
3953 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
3955 Native builds *don't* work due to incompatibilities between native
3956 and U-Boot include files.
3958 Booting assumes that (the first part of) the image booted is a
3959 stage-2 loader which in turn loads and then invokes the kernel
3960 proper. Loader sources will eventually appear in the NetBSD source
3961 tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
3962 meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz
3965 Implementation Internals:
3966 =========================
3968 The following is not intended to be a complete description of every
3969 implementation detail. However, it should help to understand the
3970 inner workings of U-Boot and make it easier to port it to custom
3974 Initial Stack, Global Data:
3975 ---------------------------
3977 The implementation of U-Boot is complicated by the fact that U-Boot
3978 starts running out of ROM (flash memory), usually without access to
3979 system RAM (because the memory controller is not initialized yet).
3980 This means that we don't have writable Data or BSS segments, and BSS
3981 is not initialized as zero. To be able to get a C environment working
3982 at all, we have to allocate at least a minimal stack. Implementation
3983 options for this are defined and restricted by the CPU used: Some CPU
3984 models provide on-chip memory (like the IMMR area on MPC8xx and
3985 MPC826x processors), on others (parts of) the data cache can be
3986 locked as (mis-) used as memory, etc.
3988 Chris Hallinan posted a good summary of these issues to the
3989 U-Boot mailing list:
3991 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
3992 From: "Chris Hallinan" <clh@net1plus.com>
3993 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
3996 Correct me if I'm wrong, folks, but the way I understand it
3997 is this: Using DCACHE as initial RAM for Stack, etc, does not
3998 require any physical RAM backing up the cache. The cleverness
3999 is that the cache is being used as a temporary supply of
4000 necessary storage before the SDRAM controller is setup. It's
4001 beyond the scope of this list to explain the details, but you
4002 can see how this works by studying the cache architecture and
4003 operation in the architecture and processor-specific manuals.
4005 OCM is On Chip Memory, which I believe the 405GP has 4K. It
4006 is another option for the system designer to use as an
4007 initial stack/RAM area prior to SDRAM being available. Either
4008 option should work for you. Using CS 4 should be fine if your
4009 board designers haven't used it for something that would
4010 cause you grief during the initial boot! It is frequently not
4013 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere
4014 with your processor/board/system design. The default value
4015 you will find in any recent u-boot distribution in
4016 walnut.h should work for you. I'd set it to a value larger
4017 than your SDRAM module. If you have a 64MB SDRAM module, set
4018 it above 400_0000. Just make sure your board has no resources
4019 that are supposed to respond to that address! That code in
4020 start.S has been around a while and should work as is when
4021 you get the config right.
4026 It is essential to remember this, since it has some impact on the C
4027 code for the initialization procedures:
4029 * Initialized global data (data segment) is read-only. Do not attempt
4032 * Do not use any uninitialized global data (or implicitely initialized
4033 as zero data - BSS segment) at all - this is undefined, initiali-
4034 zation is performed later (when relocating to RAM).
4036 * Stack space is very limited. Avoid big data buffers or things like
4039 Having only the stack as writable memory limits means we cannot use
4040 normal global data to share information beween the code. But it
4041 turned out that the implementation of U-Boot can be greatly
4042 simplified by making a global data structure (gd_t) available to all
4043 functions. We could pass a pointer to this data as argument to _all_
4044 functions, but this would bloat the code. Instead we use a feature of
4045 the GCC compiler (Global Register Variables) to share the data: we
4046 place a pointer (gd) to the global data into a register which we
4047 reserve for this purpose.
4049 When choosing a register for such a purpose we are restricted by the
4050 relevant (E)ABI specifications for the current architecture, and by
4051 GCC's implementation.
4053 For PowerPC, the following registers have specific use:
4055 R2: reserved for system use
4056 R3-R4: parameter passing and return values
4057 R5-R10: parameter passing
4058 R13: small data area pointer
4062 (U-Boot also uses R12 as internal GOT pointer. r12
4063 is a volatile register so r12 needs to be reset when
4064 going back and forth between asm and C)
4066 ==> U-Boot will use R2 to hold a pointer to the global data
4068 Note: on PPC, we could use a static initializer (since the
4069 address of the global data structure is known at compile time),
4070 but it turned out that reserving a register results in somewhat
4071 smaller code - although the code savings are not that big (on
4072 average for all boards 752 bytes for the whole U-Boot image,
4073 624 text + 127 data).
4075 On Blackfin, the normal C ABI (except for P3) is followed as documented here:
4076 http://docs.blackfin.uclinux.org/doku.php?id=application_binary_interface
4078 ==> U-Boot will use P3 to hold a pointer to the global data
4080 On ARM, the following registers are used:
4082 R0: function argument word/integer result
4083 R1-R3: function argument word
4085 R10: stack limit (used only if stack checking if enabled)
4086 R11: argument (frame) pointer
4087 R12: temporary workspace
4090 R15: program counter
4092 ==> U-Boot will use R8 to hold a pointer to the global data
4094 On Nios II, the ABI is documented here:
4095 http://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf
4097 ==> U-Boot will use gp to hold a pointer to the global data
4099 Note: on Nios II, we give "-G0" option to gcc and don't use gp
4100 to access small data sections, so gp is free.
4102 NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope,
4103 or current versions of GCC may "optimize" the code too much.
4108 U-Boot runs in system state and uses physical addresses, i.e. the
4109 MMU is not used either for address mapping nor for memory protection.
4111 The available memory is mapped to fixed addresses using the memory
4112 controller. In this process, a contiguous block is formed for each
4113 memory type (Flash, SDRAM, SRAM), even when it consists of several
4114 physical memory banks.
4116 U-Boot is installed in the first 128 kB of the first Flash bank (on
4117 TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
4118 booting and sizing and initializing DRAM, the code relocates itself
4119 to the upper end of DRAM. Immediately below the U-Boot code some
4120 memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN
4121 configuration setting]. Below that, a structure with global Board
4122 Info data is placed, followed by the stack (growing downward).
4124 Additionally, some exception handler code is copied to the low 8 kB
4125 of DRAM (0x00000000 ... 0x00001FFF).
4127 So a typical memory configuration with 16 MB of DRAM could look like
4130 0x0000 0000 Exception Vector code
4133 0x0000 2000 Free for Application Use
4139 0x00FB FF20 Monitor Stack (Growing downward)
4140 0x00FB FFAC Board Info Data and permanent copy of global data
4141 0x00FC 0000 Malloc Arena
4144 0x00FE 0000 RAM Copy of Monitor Code
4145 ... eventually: LCD or video framebuffer
4146 ... eventually: pRAM (Protected RAM - unchanged by reset)
4147 0x00FF FFFF [End of RAM]
4150 System Initialization:
4151 ----------------------
4153 In the reset configuration, U-Boot starts at the reset entry point
4154 (on most PowerPC systems at address 0x00000100). Because of the reset
4155 configuration for CS0# this is a mirror of the onboard Flash memory.
4156 To be able to re-map memory U-Boot then jumps to its link address.
4157 To be able to implement the initialization code in C, a (small!)
4158 initial stack is set up in the internal Dual Ported RAM (in case CPUs
4159 which provide such a feature like MPC8xx or MPC8260), or in a locked
4160 part of the data cache. After that, U-Boot initializes the CPU core,
4161 the caches and the SIU.
4163 Next, all (potentially) available memory banks are mapped using a
4164 preliminary mapping. For example, we put them on 512 MB boundaries
4165 (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
4166 on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
4167 programmed for SDRAM access. Using the temporary configuration, a
4168 simple memory test is run that determines the size of the SDRAM
4171 When there is more than one SDRAM bank, and the banks are of
4172 different size, the largest is mapped first. For equal size, the first
4173 bank (CS2#) is mapped first. The first mapping is always for address
4174 0x00000000, with any additional banks following immediately to create
4175 contiguous memory starting from 0.
4177 Then, the monitor installs itself at the upper end of the SDRAM area
4178 and allocates memory for use by malloc() and for the global Board
4179 Info data; also, the exception vector code is copied to the low RAM
4180 pages, and the final stack is set up.
4182 Only after this relocation will you have a "normal" C environment;
4183 until that you are restricted in several ways, mostly because you are
4184 running from ROM, and because the code will have to be relocated to a
4188 U-Boot Porting Guide:
4189 ----------------------
4191 [Based on messages by Jerry Van Baren in the U-Boot-Users mailing
4195 int main(int argc, char *argv[])
4197 sighandler_t no_more_time;
4199 signal(SIGALRM, no_more_time);
4200 alarm(PROJECT_DEADLINE - toSec (3 * WEEK));
4202 if (available_money > available_manpower) {
4203 Pay consultant to port U-Boot;
4207 Download latest U-Boot source;
4209 Subscribe to u-boot mailing list;
4212 email("Hi, I am new to U-Boot, how do I get started?");
4215 Read the README file in the top level directory;
4216 Read http://www.denx.de/twiki/bin/view/DULG/Manual;
4217 Read applicable doc/*.README;
4218 Read the source, Luke;
4219 /* find . -name "*.[chS]" | xargs grep -i <keyword> */
4222 if (available_money > toLocalCurrency ($2500))
4225 Add a lot of aggravation and time;
4227 if (a similar board exists) { /* hopefully... */
4228 cp -a board/<similar> board/<myboard>
4229 cp include/configs/<similar>.h include/configs/<myboard>.h
4231 Create your own board support subdirectory;
4232 Create your own board include/configs/<myboard>.h file;
4234 Edit new board/<myboard> files
4235 Edit new include/configs/<myboard>.h
4240 Add / modify source code;
4244 email("Hi, I am having problems...");
4246 Send patch file to the U-Boot email list;
4247 if (reasonable critiques)
4248 Incorporate improvements from email list code review;
4250 Defend code as written;
4256 void no_more_time (int sig)
4265 All contributions to U-Boot should conform to the Linux kernel
4266 coding style; see the file "Documentation/CodingStyle" and the script
4267 "scripts/Lindent" in your Linux kernel source directory. In sources
4268 originating from U-Boot a style corresponding to "Lindent -pcs" (adding
4269 spaces before parameters to function calls) is actually used.
4271 Source files originating from a different project (for example the
4272 MTD subsystem) are generally exempt from these guidelines and are not
4273 reformated to ease subsequent migration to newer versions of those
4276 Please note that U-Boot is implemented in C (and to some small parts in
4277 Assembler); no C++ is used, so please do not use C++ style comments (//)
4280 Please also stick to the following formatting rules:
4281 - remove any trailing white space
4282 - use TAB characters for indentation, not spaces
4283 - make sure NOT to use DOS '\r\n' line feeds
4284 - do not add more than 2 empty lines to source files
4285 - do not add trailing empty lines to source files
4287 Submissions which do not conform to the standards may be returned
4288 with a request to reformat the changes.
4294 Since the number of patches for U-Boot is growing, we need to
4295 establish some rules. Submissions which do not conform to these rules
4296 may be rejected, even when they contain important and valuable stuff.
4298 Please see http://www.denx.de/wiki/U-Boot/Patches for details.
4300 Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>;
4301 see http://lists.denx.de/mailman/listinfo/u-boot
4303 When you send a patch, please include the following information with
4306 * For bug fixes: a description of the bug and how your patch fixes
4307 this bug. Please try to include a way of demonstrating that the
4308 patch actually fixes something.
4310 * For new features: a description of the feature and your
4313 * A CHANGELOG entry as plaintext (separate from the patch)
4315 * For major contributions, your entry to the CREDITS file
4317 * When you add support for a new board, don't forget to add this
4318 board to the MAKEALL script, too.
4320 * If your patch adds new configuration options, don't forget to
4321 document these in the README file.
4323 * The patch itself. If you are using git (which is *strongly*
4324 recommended) you can easily generate the patch using the
4325 "git-format-patch". If you then use "git-send-email" to send it to
4326 the U-Boot mailing list, you will avoid most of the common problems
4327 with some other mail clients.
4329 If you cannot use git, use "diff -purN OLD NEW". If your version of
4330 diff does not support these options, then get the latest version of
4333 The current directory when running this command shall be the parent
4334 directory of the U-Boot source tree (i. e. please make sure that
4335 your patch includes sufficient directory information for the
4338 We prefer patches as plain text. MIME attachments are discouraged,
4339 and compressed attachments must not be used.
4341 * If one logical set of modifications affects or creates several
4342 files, all these changes shall be submitted in a SINGLE patch file.
4344 * Changesets that contain different, unrelated modifications shall be
4345 submitted as SEPARATE patches, one patch per changeset.
4350 * Before sending the patch, run the MAKEALL script on your patched
4351 source tree and make sure that no errors or warnings are reported
4352 for any of the boards.
4354 * Keep your modifications to the necessary minimum: A patch
4355 containing several unrelated changes or arbitrary reformats will be
4356 returned with a request to re-formatting / split it.
4358 * If you modify existing code, make sure that your new code does not
4359 add to the memory footprint of the code ;-) Small is beautiful!
4360 When adding new features, these should compile conditionally only
4361 (using #ifdef), and the resulting code with the new feature
4362 disabled must not need more memory than the old code without your
4365 * Remember that there is a size limit of 100 kB per message on the
4366 u-boot mailing list. Bigger patches will be moderated. If they are
4367 reasonable and not too big, they will be acknowledged. But patches
4368 bigger than the size limit should be avoided.
projects / karo-tx-uboot.git / blob