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
904 CONFIG_SH_ETHER_CACHE_WRITEBACK
905 If this option is set, the driver enables cache flush.
908 At the moment only the UHCI host controller is
909 supported (PIP405, MIP405, MPC5200); define
910 CONFIG_USB_UHCI to enable it.
911 define CONFIG_USB_KEYBOARD to enable the USB Keyboard
912 and define CONFIG_USB_STORAGE to enable the USB
915 Supported are USB Keyboards and USB Floppy drives
917 MPC5200 USB requires additional defines:
919 for 528 MHz Clock: 0x0001bbbb
923 for differential drivers: 0x00001000
924 for single ended drivers: 0x00005000
925 for differential drivers on PSC3: 0x00000100
926 for single ended drivers on PSC3: 0x00004100
927 CONFIG_SYS_USB_EVENT_POLL
928 May be defined to allow interrupt polling
929 instead of using asynchronous interrupts
932 Define the below if you wish to use the USB console.
933 Once firmware is rebuilt from a serial console issue the
934 command "setenv stdin usbtty; setenv stdout usbtty" and
935 attach your USB cable. The Unix command "dmesg" should print
936 it has found a new device. The environment variable usbtty
937 can be set to gserial or cdc_acm to enable your device to
938 appear to a USB host as a Linux gserial device or a
939 Common Device Class Abstract Control Model serial device.
940 If you select usbtty = gserial you should be able to enumerate
942 # modprobe usbserial vendor=0xVendorID product=0xProductID
943 else if using cdc_acm, simply setting the environment
944 variable usbtty to be cdc_acm should suffice. The following
945 might be defined in YourBoardName.h
948 Define this to build a UDC device
951 Define this to have a tty type of device available to
952 talk to the UDC device
954 CONFIG_SYS_CONSOLE_IS_IN_ENV
955 Define this if you want stdin, stdout &/or stderr to
959 CONFIG_SYS_USB_EXTC_CLK 0xBLAH
960 Derive USB clock from external clock "blah"
961 - CONFIG_SYS_USB_EXTC_CLK 0x02
963 CONFIG_SYS_USB_BRG_CLK 0xBLAH
964 Derive USB clock from brgclk
965 - CONFIG_SYS_USB_BRG_CLK 0x04
967 If you have a USB-IF assigned VendorID then you may wish to
968 define your own vendor specific values either in BoardName.h
969 or directly in usbd_vendor_info.h. If you don't define
970 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME,
971 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot
972 should pretend to be a Linux device to it's target host.
974 CONFIG_USBD_MANUFACTURER
975 Define this string as the name of your company for
976 - CONFIG_USBD_MANUFACTURER "my company"
978 CONFIG_USBD_PRODUCT_NAME
979 Define this string as the name of your product
980 - CONFIG_USBD_PRODUCT_NAME "acme usb device"
983 Define this as your assigned Vendor ID from the USB
984 Implementors Forum. This *must* be a genuine Vendor ID
985 to avoid polluting the USB namespace.
986 - CONFIG_USBD_VENDORID 0xFFFF
988 CONFIG_USBD_PRODUCTID
989 Define this as the unique Product ID
991 - CONFIG_USBD_PRODUCTID 0xFFFF
995 The MMC controller on the Intel PXA is supported. To
996 enable this define CONFIG_MMC. The MMC can be
997 accessed from the boot prompt by mapping the device
998 to physical memory similar to flash. Command line is
999 enabled with CONFIG_CMD_MMC. The MMC driver also works with
1000 the FAT fs. This is enabled with CONFIG_CMD_FAT.
1002 - Journaling Flash filesystem support:
1003 CONFIG_JFFS2_NAND, CONFIG_JFFS2_NAND_OFF, CONFIG_JFFS2_NAND_SIZE,
1004 CONFIG_JFFS2_NAND_DEV
1005 Define these for a default partition on a NAND device
1007 CONFIG_SYS_JFFS2_FIRST_SECTOR,
1008 CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS
1009 Define these for a default partition on a NOR device
1011 CONFIG_SYS_JFFS_CUSTOM_PART
1012 Define this to create an own partition. You have to provide a
1013 function struct part_info* jffs2_part_info(int part_num)
1015 If you define only one JFFS2 partition you may also want to
1016 #define CONFIG_SYS_JFFS_SINGLE_PART 1
1017 to disable the command chpart. This is the default when you
1018 have not defined a custom partition
1023 Define this to enable standard (PC-Style) keyboard
1027 Standard PC keyboard driver with US (is default) and
1028 GERMAN key layout (switch via environment 'keymap=de') support.
1029 Export function i8042_kbd_init, i8042_tstc and i8042_getc
1030 for cfb_console. Supports cursor blinking.
1035 Define this to enable video support (for output to
1038 CONFIG_VIDEO_CT69000
1040 Enable Chips & Technologies 69000 Video chip
1042 CONFIG_VIDEO_SMI_LYNXEM
1043 Enable Silicon Motion SMI 712/710/810 Video chip. The
1044 video output is selected via environment 'videoout'
1045 (1 = LCD and 2 = CRT). If videoout is undefined, CRT is
1048 For the CT69000 and SMI_LYNXEM drivers, videomode is
1049 selected via environment 'videomode'. Two different ways
1051 - "videomode=num" 'num' is a standard LiLo mode numbers.
1052 Following standard modes are supported (* is default):
1054 Colors 640x480 800x600 1024x768 1152x864 1280x1024
1055 -------------+---------------------------------------------
1056 8 bits | 0x301* 0x303 0x305 0x161 0x307
1057 15 bits | 0x310 0x313 0x316 0x162 0x319
1058 16 bits | 0x311 0x314 0x317 0x163 0x31A
1059 24 bits | 0x312 0x315 0x318 ? 0x31B
1060 -------------+---------------------------------------------
1061 (i.e. setenv videomode 317; saveenv; reset;)
1063 - "videomode=bootargs" all the video parameters are parsed
1064 from the bootargs. (See drivers/video/videomodes.c)
1067 CONFIG_VIDEO_SED13806
1068 Enable Epson SED13806 driver. This driver supports 8bpp
1069 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP
1070 or CONFIG_VIDEO_SED13806_16BPP
1075 Define this to enable a custom keyboard support.
1076 This simply calls drv_keyboard_init() which must be
1077 defined in your board-specific files.
1078 The only board using this so far is RBC823.
1080 - LCD Support: CONFIG_LCD
1082 Define this to enable LCD support (for output to LCD
1083 display); also select one of the supported displays
1084 by defining one of these:
1088 HITACHI TX09D70VM1CCA, 3.5", 240x320.
1090 CONFIG_NEC_NL6448AC33:
1092 NEC NL6448AC33-18. Active, color, single scan.
1094 CONFIG_NEC_NL6448BC20
1096 NEC NL6448BC20-08. 6.5", 640x480.
1097 Active, color, single scan.
1099 CONFIG_NEC_NL6448BC33_54
1101 NEC NL6448BC33-54. 10.4", 640x480.
1102 Active, color, single scan.
1106 Sharp 320x240. Active, color, single scan.
1107 It isn't 16x9, and I am not sure what it is.
1109 CONFIG_SHARP_LQ64D341
1111 Sharp LQ64D341 display, 640x480.
1112 Active, color, single scan.
1116 HLD1045 display, 640x480.
1117 Active, color, single scan.
1121 Optrex CBL50840-2 NF-FW 99 22 M5
1123 Hitachi LMG6912RPFC-00T
1127 320x240. Black & white.
1129 Normally display is black on white background; define
1130 CONFIG_SYS_WHITE_ON_BLACK to get it inverted.
1132 - Splash Screen Support: CONFIG_SPLASH_SCREEN
1134 If this option is set, the environment is checked for
1135 a variable "splashimage". If found, the usual display
1136 of logo, copyright and system information on the LCD
1137 is suppressed and the BMP image at the address
1138 specified in "splashimage" is loaded instead. The
1139 console is redirected to the "nulldev", too. This
1140 allows for a "silent" boot where a splash screen is
1141 loaded very quickly after power-on.
1143 CONFIG_SPLASH_SCREEN_ALIGN
1145 If this option is set the splash image can be freely positioned
1146 on the screen. Environment variable "splashpos" specifies the
1147 position as "x,y". If a positive number is given it is used as
1148 number of pixel from left/top. If a negative number is given it
1149 is used as number of pixel from right/bottom. You can also
1150 specify 'm' for centering the image.
1153 setenv splashpos m,m
1154 => image at center of screen
1156 setenv splashpos 30,20
1157 => image at x = 30 and y = 20
1159 setenv splashpos -10,m
1160 => vertically centered image
1161 at x = dspWidth - bmpWidth - 9
1163 - Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP
1165 If this option is set, additionally to standard BMP
1166 images, gzipped BMP images can be displayed via the
1167 splashscreen support or the bmp command.
1169 - Run length encoded BMP image (RLE8) support: CONFIG_VIDEO_BMP_RLE8
1171 If this option is set, 8-bit RLE compressed BMP images
1172 can be displayed via the splashscreen support or the
1175 - Compression support:
1178 If this option is set, support for bzip2 compressed
1179 images is included. If not, only uncompressed and gzip
1180 compressed images are supported.
1182 NOTE: the bzip2 algorithm requires a lot of RAM, so
1183 the malloc area (as defined by CONFIG_SYS_MALLOC_LEN) should
1188 If this option is set, support for lzma compressed
1191 Note: The LZMA algorithm adds between 2 and 4KB of code and it
1192 requires an amount of dynamic memory that is given by the
1195 (1846 + 768 << (lc + lp)) * sizeof(uint16)
1197 Where lc and lp stand for, respectively, Literal context bits
1198 and Literal pos bits.
1200 This value is upper-bounded by 14MB in the worst case. Anyway,
1201 for a ~4MB large kernel image, we have lc=3 and lp=0 for a
1202 total amount of (1846 + 768 << (3 + 0)) * 2 = ~41KB... that is
1203 a very small buffer.
1205 Use the lzmainfo tool to determinate the lc and lp values and
1206 then calculate the amount of needed dynamic memory (ensuring
1207 the appropriate CONFIG_SYS_MALLOC_LEN value).
1212 The address of PHY on MII bus.
1214 CONFIG_PHY_CLOCK_FREQ (ppc4xx)
1216 The clock frequency of the MII bus
1220 If this option is set, support for speed/duplex
1221 detection of gigabit PHY is included.
1223 CONFIG_PHY_RESET_DELAY
1225 Some PHY like Intel LXT971A need extra delay after
1226 reset before any MII register access is possible.
1227 For such PHY, set this option to the usec delay
1228 required. (minimum 300usec for LXT971A)
1230 CONFIG_PHY_CMD_DELAY (ppc4xx)
1232 Some PHY like Intel LXT971A need extra delay after
1233 command issued before MII status register can be read
1243 Define a default value for Ethernet address to use
1244 for the respective Ethernet interface, in case this
1245 is not determined automatically.
1250 Define a default value for the IP address to use for
1251 the default Ethernet interface, in case this is not
1252 determined through e.g. bootp.
1254 - Server IP address:
1257 Defines a default value for the IP address of a TFTP
1258 server to contact when using the "tftboot" command.
1260 CONFIG_KEEP_SERVERADDR
1262 Keeps the server's MAC address, in the env 'serveraddr'
1263 for passing to bootargs (like Linux's netconsole option)
1265 - Multicast TFTP Mode:
1268 Defines whether you want to support multicast TFTP as per
1269 rfc-2090; for example to work with atftp. Lets lots of targets
1270 tftp down the same boot image concurrently. Note: the Ethernet
1271 driver in use must provide a function: mcast() to join/leave a
1274 CONFIG_BOOTP_RANDOM_DELAY
1275 - BOOTP Recovery Mode:
1276 CONFIG_BOOTP_RANDOM_DELAY
1278 If you have many targets in a network that try to
1279 boot using BOOTP, you may want to avoid that all
1280 systems send out BOOTP requests at precisely the same
1281 moment (which would happen for instance at recovery
1282 from a power failure, when all systems will try to
1283 boot, thus flooding the BOOTP server. Defining
1284 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
1285 inserted before sending out BOOTP requests. The
1286 following delays are inserted then:
1288 1st BOOTP request: delay 0 ... 1 sec
1289 2nd BOOTP request: delay 0 ... 2 sec
1290 3rd BOOTP request: delay 0 ... 4 sec
1292 BOOTP requests: delay 0 ... 8 sec
1294 - DHCP Advanced Options:
1295 You can fine tune the DHCP functionality by defining
1296 CONFIG_BOOTP_* symbols:
1298 CONFIG_BOOTP_SUBNETMASK
1299 CONFIG_BOOTP_GATEWAY
1300 CONFIG_BOOTP_HOSTNAME
1301 CONFIG_BOOTP_NISDOMAIN
1302 CONFIG_BOOTP_BOOTPATH
1303 CONFIG_BOOTP_BOOTFILESIZE
1306 CONFIG_BOOTP_SEND_HOSTNAME
1307 CONFIG_BOOTP_NTPSERVER
1308 CONFIG_BOOTP_TIMEOFFSET
1309 CONFIG_BOOTP_VENDOREX
1311 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip
1312 environment variable, not the BOOTP server.
1314 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS
1315 serverip from a DHCP server, it is possible that more
1316 than one DNS serverip is offered to the client.
1317 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS
1318 serverip will be stored in the additional environment
1319 variable "dnsip2". The first DNS serverip is always
1320 stored in the variable "dnsip", when CONFIG_BOOTP_DNS
1323 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable
1324 to do a dynamic update of a DNS server. To do this, they
1325 need the hostname of the DHCP requester.
1326 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content
1327 of the "hostname" environment variable is passed as
1328 option 12 to the DHCP server.
1330 CONFIG_BOOTP_DHCP_REQUEST_DELAY
1332 A 32bit value in microseconds for a delay between
1333 receiving a "DHCP Offer" and sending the "DHCP Request".
1334 This fixes a problem with certain DHCP servers that don't
1335 respond 100% of the time to a "DHCP request". E.g. On an
1336 AT91RM9200 processor running at 180MHz, this delay needed
1337 to be *at least* 15,000 usec before a Windows Server 2003
1338 DHCP server would reply 100% of the time. I recommend at
1339 least 50,000 usec to be safe. The alternative is to hope
1340 that one of the retries will be successful but note that
1341 the DHCP timeout and retry process takes a longer than
1345 CONFIG_CDP_DEVICE_ID
1347 The device id used in CDP trigger frames.
1349 CONFIG_CDP_DEVICE_ID_PREFIX
1351 A two character string which is prefixed to the MAC address
1356 A printf format string which contains the ascii name of
1357 the port. Normally is set to "eth%d" which sets
1358 eth0 for the first Ethernet, eth1 for the second etc.
1360 CONFIG_CDP_CAPABILITIES
1362 A 32bit integer which indicates the device capabilities;
1363 0x00000010 for a normal host which does not forwards.
1367 An ascii string containing the version of the software.
1371 An ascii string containing the name of the platform.
1375 A 32bit integer sent on the trigger.
1377 CONFIG_CDP_POWER_CONSUMPTION
1379 A 16bit integer containing the power consumption of the
1380 device in .1 of milliwatts.
1382 CONFIG_CDP_APPLIANCE_VLAN_TYPE
1384 A byte containing the id of the VLAN.
1386 - Status LED: CONFIG_STATUS_LED
1388 Several configurations allow to display the current
1389 status using a LED. For instance, the LED will blink
1390 fast while running U-Boot code, stop blinking as
1391 soon as a reply to a BOOTP request was received, and
1392 start blinking slow once the Linux kernel is running
1393 (supported by a status LED driver in the Linux
1394 kernel). Defining CONFIG_STATUS_LED enables this
1397 - CAN Support: CONFIG_CAN_DRIVER
1399 Defining CONFIG_CAN_DRIVER enables CAN driver support
1400 on those systems that support this (optional)
1401 feature, like the TQM8xxL modules.
1403 - I2C Support: CONFIG_HARD_I2C | CONFIG_SOFT_I2C
1405 These enable I2C serial bus commands. Defining either of
1406 (but not both of) CONFIG_HARD_I2C or CONFIG_SOFT_I2C will
1407 include the appropriate I2C driver for the selected CPU.
1409 This will allow you to use i2c commands at the u-boot
1410 command line (as long as you set CONFIG_CMD_I2C in
1411 CONFIG_COMMANDS) and communicate with i2c based realtime
1412 clock chips. See common/cmd_i2c.c for a description of the
1413 command line interface.
1415 CONFIG_HARD_I2C selects a hardware I2C controller.
1417 CONFIG_SOFT_I2C configures u-boot to use a software (aka
1418 bit-banging) driver instead of CPM or similar hardware
1421 There are several other quantities that must also be
1422 defined when you define CONFIG_HARD_I2C or CONFIG_SOFT_I2C.
1424 In both cases you will need to define CONFIG_SYS_I2C_SPEED
1425 to be the frequency (in Hz) at which you wish your i2c bus
1426 to run and CONFIG_SYS_I2C_SLAVE to be the address of this node (ie
1427 the CPU's i2c node address).
1429 Now, the u-boot i2c code for the mpc8xx
1430 (arch/powerpc/cpu/mpc8xx/i2c.c) sets the CPU up as a master node
1431 and so its address should therefore be cleared to 0 (See,
1432 eg, MPC823e User's Manual p.16-473). So, set
1433 CONFIG_SYS_I2C_SLAVE to 0.
1435 CONFIG_SYS_I2C_INIT_MPC5XXX
1437 When a board is reset during an i2c bus transfer
1438 chips might think that the current transfer is still
1439 in progress. Reset the slave devices by sending start
1440 commands until the slave device responds.
1442 That's all that's required for CONFIG_HARD_I2C.
1444 If you use the software i2c interface (CONFIG_SOFT_I2C)
1445 then the following macros need to be defined (examples are
1446 from include/configs/lwmon.h):
1450 (Optional). Any commands necessary to enable the I2C
1451 controller or configure ports.
1453 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
1457 (Only for MPC8260 CPU). The I/O port to use (the code
1458 assumes both bits are on the same port). Valid values
1459 are 0..3 for ports A..D.
1463 The code necessary to make the I2C data line active
1464 (driven). If the data line is open collector, this
1467 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
1471 The code necessary to make the I2C data line tri-stated
1472 (inactive). If the data line is open collector, this
1475 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
1479 Code that returns TRUE if the I2C data line is high,
1482 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
1486 If <bit> is TRUE, sets the I2C data line high. If it
1487 is FALSE, it clears it (low).
1489 eg: #define I2C_SDA(bit) \
1490 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
1491 else immr->im_cpm.cp_pbdat &= ~PB_SDA
1495 If <bit> is TRUE, sets the I2C clock line high. If it
1496 is FALSE, it clears it (low).
1498 eg: #define I2C_SCL(bit) \
1499 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
1500 else immr->im_cpm.cp_pbdat &= ~PB_SCL
1504 This delay is invoked four times per clock cycle so this
1505 controls the rate of data transfer. The data rate thus
1506 is 1 / (I2C_DELAY * 4). Often defined to be something
1509 #define I2C_DELAY udelay(2)
1511 CONFIG_SOFT_I2C_GPIO_SCL / CONFIG_SOFT_I2C_GPIO_SDA
1513 If your arch supports the generic GPIO framework (asm/gpio.h),
1514 then you may alternatively define the two GPIOs that are to be
1515 used as SCL / SDA. Any of the previous I2C_xxx macros will
1516 have GPIO-based defaults assigned to them as appropriate.
1518 You should define these to the GPIO value as given directly to
1519 the generic GPIO functions.
1521 CONFIG_SYS_I2C_INIT_BOARD
1523 When a board is reset during an i2c bus transfer
1524 chips might think that the current transfer is still
1525 in progress. On some boards it is possible to access
1526 the i2c SCLK line directly, either by using the
1527 processor pin as a GPIO or by having a second pin
1528 connected to the bus. If this option is defined a
1529 custom i2c_init_board() routine in boards/xxx/board.c
1530 is run early in the boot sequence.
1532 CONFIG_SYS_I2C_BOARD_LATE_INIT
1534 An alternative to CONFIG_SYS_I2C_INIT_BOARD. If this option is
1535 defined a custom i2c_board_late_init() routine in
1536 boards/xxx/board.c is run AFTER the operations in i2c_init()
1537 is completed. This callpoint can be used to unreset i2c bus
1538 using CPU i2c controller register accesses for CPUs whose i2c
1539 controller provide such a method. It is called at the end of
1540 i2c_init() to allow i2c_init operations to setup the i2c bus
1541 controller on the CPU (e.g. setting bus speed & slave address).
1543 CONFIG_I2CFAST (PPC405GP|PPC405EP only)
1545 This option enables configuration of bi_iic_fast[] flags
1546 in u-boot bd_info structure based on u-boot environment
1547 variable "i2cfast". (see also i2cfast)
1549 CONFIG_I2C_MULTI_BUS
1551 This option allows the use of multiple I2C buses, each of which
1552 must have a controller. At any point in time, only one bus is
1553 active. To switch to a different bus, use the 'i2c dev' command.
1554 Note that bus numbering is zero-based.
1556 CONFIG_SYS_I2C_NOPROBES
1558 This option specifies a list of I2C devices that will be skipped
1559 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS
1560 is set, specify a list of bus-device pairs. Otherwise, specify
1561 a 1D array of device addresses
1564 #undef CONFIG_I2C_MULTI_BUS
1565 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68}
1567 will skip addresses 0x50 and 0x68 on a board with one I2C bus
1569 #define CONFIG_I2C_MULTI_BUS
1570 #define CONFIG_SYS_I2C_MULTI_NOPROBES {{0,0x50},{0,0x68},{1,0x54}}
1572 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1
1574 CONFIG_SYS_SPD_BUS_NUM
1576 If defined, then this indicates the I2C bus number for DDR SPD.
1577 If not defined, then U-Boot assumes that SPD is on I2C bus 0.
1579 CONFIG_SYS_RTC_BUS_NUM
1581 If defined, then this indicates the I2C bus number for the RTC.
1582 If not defined, then U-Boot assumes that RTC is on I2C bus 0.
1584 CONFIG_SYS_DTT_BUS_NUM
1586 If defined, then this indicates the I2C bus number for the DTT.
1587 If not defined, then U-Boot assumes that DTT is on I2C bus 0.
1589 CONFIG_SYS_I2C_DTT_ADDR:
1591 If defined, specifies the I2C address of the DTT device.
1592 If not defined, then U-Boot uses predefined value for
1593 specified DTT device.
1597 Define this option if you want to use Freescale's I2C driver in
1598 drivers/i2c/fsl_i2c.c.
1602 Define this option if you have I2C devices reached over 1 .. n
1603 I2C Muxes like the pca9544a. This option addes a new I2C
1604 Command "i2c bus [muxtype:muxaddr:muxchannel]" which adds a
1605 new I2C Bus to the existing I2C Busses. If you select the
1606 new Bus with "i2c dev", u-bbot sends first the commandos for
1607 the muxes to activate this new "bus".
1609 CONFIG_I2C_MULTI_BUS must be also defined, to use this
1613 Adding a new I2C Bus reached over 2 pca9544a muxes
1614 The First mux with address 70 and channel 6
1615 The Second mux with address 71 and channel 4
1617 => i2c bus pca9544a:70:6:pca9544a:71:4
1619 Use the "i2c bus" command without parameter, to get a list
1620 of I2C Busses with muxes:
1623 Busses reached over muxes:
1625 reached over Mux(es):
1628 reached over Mux(es):
1633 If you now switch to the new I2C Bus 3 with "i2c dev 3"
1634 u-boot sends First the Commando to the mux@70 to enable
1635 channel 6, and then the Commando to the mux@71 to enable
1638 After that, you can use the "normal" i2c commands as
1639 usual, to communicate with your I2C devices behind
1642 This option is actually implemented for the bitbanging
1643 algorithm in common/soft_i2c.c and for the Hardware I2C
1644 Bus on the MPC8260. But it should be not so difficult
1645 to add this option to other architectures.
1647 CONFIG_SOFT_I2C_READ_REPEATED_START
1649 defining this will force the i2c_read() function in
1650 the soft_i2c driver to perform an I2C repeated start
1651 between writing the address pointer and reading the
1652 data. If this define is omitted the default behaviour
1653 of doing a stop-start sequence will be used. Most I2C
1654 devices can use either method, but some require one or
1657 - SPI Support: CONFIG_SPI
1659 Enables SPI driver (so far only tested with
1660 SPI EEPROM, also an instance works with Crystal A/D and
1661 D/As on the SACSng board)
1665 Enables extended (16-bit) SPI EEPROM addressing.
1666 (symmetrical to CONFIG_I2C_X)
1670 Enables a software (bit-bang) SPI driver rather than
1671 using hardware support. This is a general purpose
1672 driver that only requires three general I/O port pins
1673 (two outputs, one input) to function. If this is
1674 defined, the board configuration must define several
1675 SPI configuration items (port pins to use, etc). For
1676 an example, see include/configs/sacsng.h.
1680 Enables a hardware SPI driver for general-purpose reads
1681 and writes. As with CONFIG_SOFT_SPI, the board configuration
1682 must define a list of chip-select function pointers.
1683 Currently supported on some MPC8xxx processors. For an
1684 example, see include/configs/mpc8349emds.h.
1688 Enables the driver for the SPI controllers on i.MX and MXC
1689 SoCs. Currently only i.MX31 is supported.
1691 - FPGA Support: CONFIG_FPGA
1693 Enables FPGA subsystem.
1695 CONFIG_FPGA_<vendor>
1697 Enables support for specific chip vendors.
1700 CONFIG_FPGA_<family>
1702 Enables support for FPGA family.
1703 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX)
1707 Specify the number of FPGA devices to support.
1709 CONFIG_SYS_FPGA_PROG_FEEDBACK
1711 Enable printing of hash marks during FPGA configuration.
1713 CONFIG_SYS_FPGA_CHECK_BUSY
1715 Enable checks on FPGA configuration interface busy
1716 status by the configuration function. This option
1717 will require a board or device specific function to
1722 If defined, a function that provides delays in the FPGA
1723 configuration driver.
1725 CONFIG_SYS_FPGA_CHECK_CTRLC
1726 Allow Control-C to interrupt FPGA configuration
1728 CONFIG_SYS_FPGA_CHECK_ERROR
1730 Check for configuration errors during FPGA bitfile
1731 loading. For example, abort during Virtex II
1732 configuration if the INIT_B line goes low (which
1733 indicated a CRC error).
1735 CONFIG_SYS_FPGA_WAIT_INIT
1737 Maximum time to wait for the INIT_B line to deassert
1738 after PROB_B has been deasserted during a Virtex II
1739 FPGA configuration sequence. The default time is 500
1742 CONFIG_SYS_FPGA_WAIT_BUSY
1744 Maximum time to wait for BUSY to deassert during
1745 Virtex II FPGA configuration. The default is 5 ms.
1747 CONFIG_SYS_FPGA_WAIT_CONFIG
1749 Time to wait after FPGA configuration. The default is
1752 - Configuration Management:
1755 If defined, this string will be added to the U-Boot
1756 version information (U_BOOT_VERSION)
1758 - Vendor Parameter Protection:
1760 U-Boot considers the values of the environment
1761 variables "serial#" (Board Serial Number) and
1762 "ethaddr" (Ethernet Address) to be parameters that
1763 are set once by the board vendor / manufacturer, and
1764 protects these variables from casual modification by
1765 the user. Once set, these variables are read-only,
1766 and write or delete attempts are rejected. You can
1767 change this behaviour:
1769 If CONFIG_ENV_OVERWRITE is #defined in your config
1770 file, the write protection for vendor parameters is
1771 completely disabled. Anybody can change or delete
1774 Alternatively, if you #define _both_ CONFIG_ETHADDR
1775 _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
1776 Ethernet address is installed in the environment,
1777 which can be changed exactly ONCE by the user. [The
1778 serial# is unaffected by this, i. e. it remains
1784 Define this variable to enable the reservation of
1785 "protected RAM", i. e. RAM which is not overwritten
1786 by U-Boot. Define CONFIG_PRAM to hold the number of
1787 kB you want to reserve for pRAM. You can overwrite
1788 this default value by defining an environment
1789 variable "pram" to the number of kB you want to
1790 reserve. Note that the board info structure will
1791 still show the full amount of RAM. If pRAM is
1792 reserved, a new environment variable "mem" will
1793 automatically be defined to hold the amount of
1794 remaining RAM in a form that can be passed as boot
1795 argument to Linux, for instance like that:
1797 setenv bootargs ... mem=\${mem}
1800 This way you can tell Linux not to use this memory,
1801 either, which results in a memory region that will
1802 not be affected by reboots.
1804 *WARNING* If your board configuration uses automatic
1805 detection of the RAM size, you must make sure that
1806 this memory test is non-destructive. So far, the
1807 following board configurations are known to be
1810 ETX094, IVMS8, IVML24, SPD8xx, TQM8xxL,
1811 HERMES, IP860, RPXlite, LWMON, LANTEC,
1817 Define this variable to stop the system in case of a
1818 fatal error, so that you have to reset it manually.
1819 This is probably NOT a good idea for an embedded
1820 system where you want the system to reboot
1821 automatically as fast as possible, but it may be
1822 useful during development since you can try to debug
1823 the conditions that lead to the situation.
1825 CONFIG_NET_RETRY_COUNT
1827 This variable defines the number of retries for
1828 network operations like ARP, RARP, TFTP, or BOOTP
1829 before giving up the operation. If not defined, a
1830 default value of 5 is used.
1834 Timeout waiting for an ARP reply in milliseconds.
1836 - Command Interpreter:
1837 CONFIG_AUTO_COMPLETE
1839 Enable auto completion of commands using TAB.
1841 Note that this feature has NOT been implemented yet
1842 for the "hush" shell.
1845 CONFIG_SYS_HUSH_PARSER
1847 Define this variable to enable the "hush" shell (from
1848 Busybox) as command line interpreter, thus enabling
1849 powerful command line syntax like
1850 if...then...else...fi conditionals or `&&' and '||'
1851 constructs ("shell scripts").
1853 If undefined, you get the old, much simpler behaviour
1854 with a somewhat smaller memory footprint.
1857 CONFIG_SYS_PROMPT_HUSH_PS2
1859 This defines the secondary prompt string, which is
1860 printed when the command interpreter needs more input
1861 to complete a command. Usually "> ".
1865 In the current implementation, the local variables
1866 space and global environment variables space are
1867 separated. Local variables are those you define by
1868 simply typing `name=value'. To access a local
1869 variable later on, you have write `$name' or
1870 `${name}'; to execute the contents of a variable
1871 directly type `$name' at the command prompt.
1873 Global environment variables are those you use
1874 setenv/printenv to work with. To run a command stored
1875 in such a variable, you need to use the run command,
1876 and you must not use the '$' sign to access them.
1878 To store commands and special characters in a
1879 variable, please use double quotation marks
1880 surrounding the whole text of the variable, instead
1881 of the backslashes before semicolons and special
1884 - Commandline Editing and History:
1885 CONFIG_CMDLINE_EDITING
1887 Enable editing and History functions for interactive
1888 commandline input operations
1890 - Default Environment:
1891 CONFIG_EXTRA_ENV_SETTINGS
1893 Define this to contain any number of null terminated
1894 strings (variable = value pairs) that will be part of
1895 the default environment compiled into the boot image.
1897 For example, place something like this in your
1898 board's config file:
1900 #define CONFIG_EXTRA_ENV_SETTINGS \
1904 Warning: This method is based on knowledge about the
1905 internal format how the environment is stored by the
1906 U-Boot code. This is NOT an official, exported
1907 interface! Although it is unlikely that this format
1908 will change soon, there is no guarantee either.
1909 You better know what you are doing here.
1911 Note: overly (ab)use of the default environment is
1912 discouraged. Make sure to check other ways to preset
1913 the environment like the "source" command or the
1916 - DataFlash Support:
1917 CONFIG_HAS_DATAFLASH
1919 Defining this option enables DataFlash features and
1920 allows to read/write in Dataflash via the standard
1923 - SystemACE Support:
1926 Adding this option adds support for Xilinx SystemACE
1927 chips attached via some sort of local bus. The address
1928 of the chip must also be defined in the
1929 CONFIG_SYS_SYSTEMACE_BASE macro. For example:
1931 #define CONFIG_SYSTEMACE
1932 #define CONFIG_SYS_SYSTEMACE_BASE 0xf0000000
1934 When SystemACE support is added, the "ace" device type
1935 becomes available to the fat commands, i.e. fatls.
1937 - TFTP Fixed UDP Port:
1940 If this is defined, the environment variable tftpsrcp
1941 is used to supply the TFTP UDP source port value.
1942 If tftpsrcp isn't defined, the normal pseudo-random port
1943 number generator is used.
1945 Also, the environment variable tftpdstp is used to supply
1946 the TFTP UDP destination port value. If tftpdstp isn't
1947 defined, the normal port 69 is used.
1949 The purpose for tftpsrcp is to allow a TFTP server to
1950 blindly start the TFTP transfer using the pre-configured
1951 target IP address and UDP port. This has the effect of
1952 "punching through" the (Windows XP) firewall, allowing
1953 the remainder of the TFTP transfer to proceed normally.
1954 A better solution is to properly configure the firewall,
1955 but sometimes that is not allowed.
1957 - Show boot progress:
1958 CONFIG_SHOW_BOOT_PROGRESS
1960 Defining this option allows to add some board-
1961 specific code (calling a user-provided function
1962 "show_boot_progress(int)") that enables you to show
1963 the system's boot progress on some display (for
1964 example, some LED's) on your board. At the moment,
1965 the following checkpoints are implemented:
1967 Legacy uImage format:
1970 1 common/cmd_bootm.c before attempting to boot an image
1971 -1 common/cmd_bootm.c Image header has bad magic number
1972 2 common/cmd_bootm.c Image header has correct magic number
1973 -2 common/cmd_bootm.c Image header has bad checksum
1974 3 common/cmd_bootm.c Image header has correct checksum
1975 -3 common/cmd_bootm.c Image data has bad checksum
1976 4 common/cmd_bootm.c Image data has correct checksum
1977 -4 common/cmd_bootm.c Image is for unsupported architecture
1978 5 common/cmd_bootm.c Architecture check OK
1979 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi)
1980 6 common/cmd_bootm.c Image Type check OK
1981 -6 common/cmd_bootm.c gunzip uncompression error
1982 -7 common/cmd_bootm.c Unimplemented compression type
1983 7 common/cmd_bootm.c Uncompression OK
1984 8 common/cmd_bootm.c No uncompress/copy overwrite error
1985 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX)
1987 9 common/image.c Start initial ramdisk verification
1988 -10 common/image.c Ramdisk header has bad magic number
1989 -11 common/image.c Ramdisk header has bad checksum
1990 10 common/image.c Ramdisk header is OK
1991 -12 common/image.c Ramdisk data has bad checksum
1992 11 common/image.c Ramdisk data has correct checksum
1993 12 common/image.c Ramdisk verification complete, start loading
1994 -13 common/image.c Wrong Image Type (not PPC Linux ramdisk)
1995 13 common/image.c Start multifile image verification
1996 14 common/image.c No initial ramdisk, no multifile, continue.
1998 15 arch/<arch>/lib/bootm.c All preparation done, transferring control to OS
2000 -30 arch/powerpc/lib/board.c Fatal error, hang the system
2001 -31 post/post.c POST test failed, detected by post_output_backlog()
2002 -32 post/post.c POST test failed, detected by post_run_single()
2004 34 common/cmd_doc.c before loading a Image from a DOC device
2005 -35 common/cmd_doc.c Bad usage of "doc" command
2006 35 common/cmd_doc.c correct usage of "doc" command
2007 -36 common/cmd_doc.c No boot device
2008 36 common/cmd_doc.c correct boot device
2009 -37 common/cmd_doc.c Unknown Chip ID on boot device
2010 37 common/cmd_doc.c correct chip ID found, device available
2011 -38 common/cmd_doc.c Read Error on boot device
2012 38 common/cmd_doc.c reading Image header from DOC device OK
2013 -39 common/cmd_doc.c Image header has bad magic number
2014 39 common/cmd_doc.c Image header has correct magic number
2015 -40 common/cmd_doc.c Error reading Image from DOC device
2016 40 common/cmd_doc.c Image header has correct magic number
2017 41 common/cmd_ide.c before loading a Image from a IDE device
2018 -42 common/cmd_ide.c Bad usage of "ide" command
2019 42 common/cmd_ide.c correct usage of "ide" command
2020 -43 common/cmd_ide.c No boot device
2021 43 common/cmd_ide.c boot device found
2022 -44 common/cmd_ide.c Device not available
2023 44 common/cmd_ide.c Device available
2024 -45 common/cmd_ide.c wrong partition selected
2025 45 common/cmd_ide.c partition selected
2026 -46 common/cmd_ide.c Unknown partition table
2027 46 common/cmd_ide.c valid partition table found
2028 -47 common/cmd_ide.c Invalid partition type
2029 47 common/cmd_ide.c correct partition type
2030 -48 common/cmd_ide.c Error reading Image Header on boot device
2031 48 common/cmd_ide.c reading Image Header from IDE device OK
2032 -49 common/cmd_ide.c Image header has bad magic number
2033 49 common/cmd_ide.c Image header has correct magic number
2034 -50 common/cmd_ide.c Image header has bad checksum
2035 50 common/cmd_ide.c Image header has correct checksum
2036 -51 common/cmd_ide.c Error reading Image from IDE device
2037 51 common/cmd_ide.c reading Image from IDE device OK
2038 52 common/cmd_nand.c before loading a Image from a NAND device
2039 -53 common/cmd_nand.c Bad usage of "nand" command
2040 53 common/cmd_nand.c correct usage of "nand" command
2041 -54 common/cmd_nand.c No boot device
2042 54 common/cmd_nand.c boot device found
2043 -55 common/cmd_nand.c Unknown Chip ID on boot device
2044 55 common/cmd_nand.c correct chip ID found, device available
2045 -56 common/cmd_nand.c Error reading Image Header on boot device
2046 56 common/cmd_nand.c reading Image Header from NAND device OK
2047 -57 common/cmd_nand.c Image header has bad magic number
2048 57 common/cmd_nand.c Image header has correct magic number
2049 -58 common/cmd_nand.c Error reading Image from NAND device
2050 58 common/cmd_nand.c reading Image from NAND device OK
2052 -60 common/env_common.c Environment has a bad CRC, using default
2054 64 net/eth.c starting with Ethernet configuration.
2055 -64 net/eth.c no Ethernet found.
2056 65 net/eth.c Ethernet found.
2058 -80 common/cmd_net.c usage wrong
2059 80 common/cmd_net.c before calling NetLoop()
2060 -81 common/cmd_net.c some error in NetLoop() occurred
2061 81 common/cmd_net.c NetLoop() back without error
2062 -82 common/cmd_net.c size == 0 (File with size 0 loaded)
2063 82 common/cmd_net.c trying automatic boot
2064 83 common/cmd_net.c running "source" command
2065 -83 common/cmd_net.c some error in automatic boot or "source" command
2066 84 common/cmd_net.c end without errors
2071 100 common/cmd_bootm.c Kernel FIT Image has correct format
2072 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format
2073 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration
2074 -101 common/cmd_bootm.c Can't get configuration for kernel subimage
2075 102 common/cmd_bootm.c Kernel unit name specified
2076 -103 common/cmd_bootm.c Can't get kernel subimage node offset
2077 103 common/cmd_bootm.c Found configuration node
2078 104 common/cmd_bootm.c Got kernel subimage node offset
2079 -104 common/cmd_bootm.c Kernel subimage hash verification failed
2080 105 common/cmd_bootm.c Kernel subimage hash verification OK
2081 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture
2082 106 common/cmd_bootm.c Architecture check OK
2083 -106 common/cmd_bootm.c Kernel subimage has wrong type
2084 107 common/cmd_bootm.c Kernel subimage type OK
2085 -107 common/cmd_bootm.c Can't get kernel subimage data/size
2086 108 common/cmd_bootm.c Got kernel subimage data/size
2087 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT)
2088 -109 common/cmd_bootm.c Can't get kernel subimage type
2089 -110 common/cmd_bootm.c Can't get kernel subimage comp
2090 -111 common/cmd_bootm.c Can't get kernel subimage os
2091 -112 common/cmd_bootm.c Can't get kernel subimage load address
2092 -113 common/cmd_bootm.c Image uncompress/copy overwrite error
2094 120 common/image.c Start initial ramdisk verification
2095 -120 common/image.c Ramdisk FIT image has incorrect format
2096 121 common/image.c Ramdisk FIT image has correct format
2097 122 common/image.c No ramdisk subimage unit name, using configuration
2098 -122 common/image.c Can't get configuration for ramdisk subimage
2099 123 common/image.c Ramdisk unit name specified
2100 -124 common/image.c Can't get ramdisk subimage node offset
2101 125 common/image.c Got ramdisk subimage node offset
2102 -125 common/image.c Ramdisk subimage hash verification failed
2103 126 common/image.c Ramdisk subimage hash verification OK
2104 -126 common/image.c Ramdisk subimage for unsupported architecture
2105 127 common/image.c Architecture check OK
2106 -127 common/image.c Can't get ramdisk subimage data/size
2107 128 common/image.c Got ramdisk subimage data/size
2108 129 common/image.c Can't get ramdisk load address
2109 -129 common/image.c Got ramdisk load address
2111 -130 common/cmd_doc.c Incorrect FIT image format
2112 131 common/cmd_doc.c FIT image format OK
2114 -140 common/cmd_ide.c Incorrect FIT image format
2115 141 common/cmd_ide.c FIT image format OK
2117 -150 common/cmd_nand.c Incorrect FIT image format
2118 151 common/cmd_nand.c FIT image format OK
2120 - Automatic software updates via TFTP server
2122 CONFIG_UPDATE_TFTP_CNT_MAX
2123 CONFIG_UPDATE_TFTP_MSEC_MAX
2125 These options enable and control the auto-update feature;
2126 for a more detailed description refer to doc/README.update.
2128 - MTD Support (mtdparts command, UBI support)
2131 Adds the MTD device infrastructure from the Linux kernel.
2132 Needed for mtdparts command support.
2134 CONFIG_MTD_PARTITIONS
2136 Adds the MTD partitioning infrastructure from the Linux
2137 kernel. Needed for UBI support.
2143 [so far only for SMDK2400 and TRAB boards]
2145 - Modem support enable:
2146 CONFIG_MODEM_SUPPORT
2148 - RTS/CTS Flow control enable:
2151 - Modem debug support:
2152 CONFIG_MODEM_SUPPORT_DEBUG
2154 Enables debugging stuff (char screen[1024], dbg())
2155 for modem support. Useful only with BDI2000.
2157 - Interrupt support (PPC):
2159 There are common interrupt_init() and timer_interrupt()
2160 for all PPC archs. interrupt_init() calls interrupt_init_cpu()
2161 for CPU specific initialization. interrupt_init_cpu()
2162 should set decrementer_count to appropriate value. If
2163 CPU resets decrementer automatically after interrupt
2164 (ppc4xx) it should set decrementer_count to zero.
2165 timer_interrupt() calls timer_interrupt_cpu() for CPU
2166 specific handling. If board has watchdog / status_led
2167 / other_activity_monitor it works automatically from
2168 general timer_interrupt().
2172 In the target system modem support is enabled when a
2173 specific key (key combination) is pressed during
2174 power-on. Otherwise U-Boot will boot normally
2175 (autoboot). The key_pressed() function is called from
2176 board_init(). Currently key_pressed() is a dummy
2177 function, returning 1 and thus enabling modem
2180 If there are no modem init strings in the
2181 environment, U-Boot proceed to autoboot; the
2182 previous output (banner, info printfs) will be
2185 See also: doc/README.Modem
2188 Configuration Settings:
2189 -----------------------
2191 - CONFIG_SYS_LONGHELP: Defined when you want long help messages included;
2192 undefine this when you're short of memory.
2194 - CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default
2195 width of the commands listed in the 'help' command output.
2197 - CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to
2198 prompt for user input.
2200 - CONFIG_SYS_CBSIZE: Buffer size for input from the Console
2202 - CONFIG_SYS_PBSIZE: Buffer size for Console output
2204 - CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands
2206 - CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to
2207 the application (usually a Linux kernel) when it is
2210 - CONFIG_SYS_BAUDRATE_TABLE:
2211 List of legal baudrate settings for this board.
2213 - CONFIG_SYS_CONSOLE_INFO_QUIET
2214 Suppress display of console information at boot.
2216 - CONFIG_SYS_CONSOLE_IS_IN_ENV
2217 If the board specific function
2218 extern int overwrite_console (void);
2219 returns 1, the stdin, stderr and stdout are switched to the
2220 serial port, else the settings in the environment are used.
2222 - CONFIG_SYS_CONSOLE_OVERWRITE_ROUTINE
2223 Enable the call to overwrite_console().
2225 - CONFIG_SYS_CONSOLE_ENV_OVERWRITE
2226 Enable overwrite of previous console environment settings.
2228 - CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END:
2229 Begin and End addresses of the area used by the
2232 - CONFIG_SYS_ALT_MEMTEST:
2233 Enable an alternate, more extensive memory test.
2235 - CONFIG_SYS_MEMTEST_SCRATCH:
2236 Scratch address used by the alternate memory test
2237 You only need to set this if address zero isn't writeable
2239 - CONFIG_SYS_MEM_TOP_HIDE (PPC only):
2240 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header,
2241 this specified memory area will get subtracted from the top
2242 (end) of RAM and won't get "touched" at all by U-Boot. By
2243 fixing up gd->ram_size the Linux kernel should gets passed
2244 the now "corrected" memory size and won't touch it either.
2245 This should work for arch/ppc and arch/powerpc. Only Linux
2246 board ports in arch/powerpc with bootwrapper support that
2247 recalculate the memory size from the SDRAM controller setup
2248 will have to get fixed in Linux additionally.
2250 This option can be used as a workaround for the 440EPx/GRx
2251 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't
2254 WARNING: Please make sure that this value is a multiple of
2255 the Linux page size (normally 4k). If this is not the case,
2256 then the end address of the Linux memory will be located at a
2257 non page size aligned address and this could cause major
2260 - CONFIG_SYS_TFTP_LOADADDR:
2261 Default load address for network file downloads
2263 - CONFIG_SYS_LOADS_BAUD_CHANGE:
2264 Enable temporary baudrate change while serial download
2266 - CONFIG_SYS_SDRAM_BASE:
2267 Physical start address of SDRAM. _Must_ be 0 here.
2269 - CONFIG_SYS_MBIO_BASE:
2270 Physical start address of Motherboard I/O (if using a
2273 - CONFIG_SYS_FLASH_BASE:
2274 Physical start address of Flash memory.
2276 - CONFIG_SYS_MONITOR_BASE:
2277 Physical start address of boot monitor code (set by
2278 make config files to be same as the text base address
2279 (CONFIG_SYS_TEXT_BASE) used when linking) - same as
2280 CONFIG_SYS_FLASH_BASE when booting from flash.
2282 - CONFIG_SYS_MONITOR_LEN:
2283 Size of memory reserved for monitor code, used to
2284 determine _at_compile_time_ (!) if the environment is
2285 embedded within the U-Boot image, or in a separate
2288 - CONFIG_SYS_MALLOC_LEN:
2289 Size of DRAM reserved for malloc() use.
2291 - CONFIG_SYS_BOOTM_LEN:
2292 Normally compressed uImages are limited to an
2293 uncompressed size of 8 MBytes. If this is not enough,
2294 you can define CONFIG_SYS_BOOTM_LEN in your board config file
2295 to adjust this setting to your needs.
2297 - CONFIG_SYS_BOOTMAPSZ:
2298 Maximum size of memory mapped by the startup code of
2299 the Linux kernel; all data that must be processed by
2300 the Linux kernel (bd_info, boot arguments, FDT blob if
2301 used) must be put below this limit, unless "bootm_low"
2302 enviroment variable is defined and non-zero. In such case
2303 all data for the Linux kernel must be between "bootm_low"
2304 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ.
2306 - CONFIG_SYS_BOOT_RAMDISK_HIGH:
2307 Enable initrd_high functionality. If defined then the
2308 initrd_high feature is enabled and the bootm ramdisk subcommand
2311 - CONFIG_SYS_BOOT_GET_CMDLINE:
2312 Enables allocating and saving kernel cmdline in space between
2313 "bootm_low" and "bootm_low" + BOOTMAPSZ.
2315 - CONFIG_SYS_BOOT_GET_KBD:
2316 Enables allocating and saving a kernel copy of the bd_info in
2317 space between "bootm_low" and "bootm_low" + BOOTMAPSZ.
2319 - CONFIG_SYS_MAX_FLASH_BANKS:
2320 Max number of Flash memory banks
2322 - CONFIG_SYS_MAX_FLASH_SECT:
2323 Max number of sectors on a Flash chip
2325 - CONFIG_SYS_FLASH_ERASE_TOUT:
2326 Timeout for Flash erase operations (in ms)
2328 - CONFIG_SYS_FLASH_WRITE_TOUT:
2329 Timeout for Flash write operations (in ms)
2331 - CONFIG_SYS_FLASH_LOCK_TOUT
2332 Timeout for Flash set sector lock bit operation (in ms)
2334 - CONFIG_SYS_FLASH_UNLOCK_TOUT
2335 Timeout for Flash clear lock bits operation (in ms)
2337 - CONFIG_SYS_FLASH_PROTECTION
2338 If defined, hardware flash sectors protection is used
2339 instead of U-Boot software protection.
2341 - CONFIG_SYS_DIRECT_FLASH_TFTP:
2343 Enable TFTP transfers directly to flash memory;
2344 without this option such a download has to be
2345 performed in two steps: (1) download to RAM, and (2)
2346 copy from RAM to flash.
2348 The two-step approach is usually more reliable, since
2349 you can check if the download worked before you erase
2350 the flash, but in some situations (when system RAM is
2351 too limited to allow for a temporary copy of the
2352 downloaded image) this option may be very useful.
2354 - CONFIG_SYS_FLASH_CFI:
2355 Define if the flash driver uses extra elements in the
2356 common flash structure for storing flash geometry.
2358 - CONFIG_FLASH_CFI_DRIVER
2359 This option also enables the building of the cfi_flash driver
2360 in the drivers directory
2362 - CONFIG_FLASH_CFI_MTD
2363 This option enables the building of the cfi_mtd driver
2364 in the drivers directory. The driver exports CFI flash
2367 - CONFIG_SYS_FLASH_USE_BUFFER_WRITE
2368 Use buffered writes to flash.
2370 - CONFIG_FLASH_SPANSION_S29WS_N
2371 s29ws-n MirrorBit flash has non-standard addresses for buffered
2374 - CONFIG_SYS_FLASH_QUIET_TEST
2375 If this option is defined, the common CFI flash doesn't
2376 print it's warning upon not recognized FLASH banks. This
2377 is useful, if some of the configured banks are only
2378 optionally available.
2380 - CONFIG_FLASH_SHOW_PROGRESS
2381 If defined (must be an integer), print out countdown
2382 digits and dots. Recommended value: 45 (9..1) for 80
2383 column displays, 15 (3..1) for 40 column displays.
2385 - CONFIG_SYS_RX_ETH_BUFFER:
2386 Defines the number of Ethernet receive buffers. On some
2387 Ethernet controllers it is recommended to set this value
2388 to 8 or even higher (EEPRO100 or 405 EMAC), since all
2389 buffers can be full shortly after enabling the interface
2390 on high Ethernet traffic.
2391 Defaults to 4 if not defined.
2393 - CONFIG_ENV_MAX_ENTRIES
2395 Maximum number of entries in the hash table that is used
2396 internally to store the environment settings. The default
2397 setting is supposed to be generous and should work in most
2398 cases. This setting can be used to tune behaviour; see
2399 lib/hashtable.c for details.
2401 The following definitions that deal with the placement and management
2402 of environment data (variable area); in general, we support the
2403 following configurations:
2405 - CONFIG_ENV_IS_IN_FLASH:
2407 Define this if the environment is in flash memory.
2409 a) The environment occupies one whole flash sector, which is
2410 "embedded" in the text segment with the U-Boot code. This
2411 happens usually with "bottom boot sector" or "top boot
2412 sector" type flash chips, which have several smaller
2413 sectors at the start or the end. For instance, such a
2414 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In
2415 such a case you would place the environment in one of the
2416 4 kB sectors - with U-Boot code before and after it. With
2417 "top boot sector" type flash chips, you would put the
2418 environment in one of the last sectors, leaving a gap
2419 between U-Boot and the environment.
2421 - CONFIG_ENV_OFFSET:
2423 Offset of environment data (variable area) to the
2424 beginning of flash memory; for instance, with bottom boot
2425 type flash chips the second sector can be used: the offset
2426 for this sector is given here.
2428 CONFIG_ENV_OFFSET is used relative to CONFIG_SYS_FLASH_BASE.
2432 This is just another way to specify the start address of
2433 the flash sector containing the environment (instead of
2436 - CONFIG_ENV_SECT_SIZE:
2438 Size of the sector containing the environment.
2441 b) Sometimes flash chips have few, equal sized, BIG sectors.
2442 In such a case you don't want to spend a whole sector for
2447 If you use this in combination with CONFIG_ENV_IS_IN_FLASH
2448 and CONFIG_ENV_SECT_SIZE, you can specify to use only a part
2449 of this flash sector for the environment. This saves
2450 memory for the RAM copy of the environment.
2452 It may also save flash memory if you decide to use this
2453 when your environment is "embedded" within U-Boot code,
2454 since then the remainder of the flash sector could be used
2455 for U-Boot code. It should be pointed out that this is
2456 STRONGLY DISCOURAGED from a robustness point of view:
2457 updating the environment in flash makes it always
2458 necessary to erase the WHOLE sector. If something goes
2459 wrong before the contents has been restored from a copy in
2460 RAM, your target system will be dead.
2462 - CONFIG_ENV_ADDR_REDUND
2463 CONFIG_ENV_SIZE_REDUND
2465 These settings describe a second storage area used to hold
2466 a redundant copy of the environment data, so that there is
2467 a valid backup copy in case there is a power failure during
2468 a "saveenv" operation.
2470 BE CAREFUL! Any changes to the flash layout, and some changes to the
2471 source code will make it necessary to adapt <board>/u-boot.lds*
2475 - CONFIG_ENV_IS_IN_NVRAM:
2477 Define this if you have some non-volatile memory device
2478 (NVRAM, battery buffered SRAM) which you want to use for the
2484 These two #defines are used to determine the memory area you
2485 want to use for environment. It is assumed that this memory
2486 can just be read and written to, without any special
2489 BE CAREFUL! The first access to the environment happens quite early
2490 in U-Boot initalization (when we try to get the setting of for the
2491 console baudrate). You *MUST* have mapped your NVRAM area then, or
2494 Please note that even with NVRAM we still use a copy of the
2495 environment in RAM: we could work on NVRAM directly, but we want to
2496 keep settings there always unmodified except somebody uses "saveenv"
2497 to save the current settings.
2500 - CONFIG_ENV_IS_IN_EEPROM:
2502 Use this if you have an EEPROM or similar serial access
2503 device and a driver for it.
2505 - CONFIG_ENV_OFFSET:
2508 These two #defines specify the offset and size of the
2509 environment area within the total memory of your EEPROM.
2511 - CONFIG_SYS_I2C_EEPROM_ADDR:
2512 If defined, specified the chip address of the EEPROM device.
2513 The default address is zero.
2515 - CONFIG_SYS_EEPROM_PAGE_WRITE_BITS:
2516 If defined, the number of bits used to address bytes in a
2517 single page in the EEPROM device. A 64 byte page, for example
2518 would require six bits.
2520 - CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS:
2521 If defined, the number of milliseconds to delay between
2522 page writes. The default is zero milliseconds.
2524 - CONFIG_SYS_I2C_EEPROM_ADDR_LEN:
2525 The length in bytes of the EEPROM memory array address. Note
2526 that this is NOT the chip address length!
2528 - CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW:
2529 EEPROM chips that implement "address overflow" are ones
2530 like Catalyst 24WC04/08/16 which has 9/10/11 bits of
2531 address and the extra bits end up in the "chip address" bit
2532 slots. This makes a 24WC08 (1Kbyte) chip look like four 256
2535 Note that we consider the length of the address field to
2536 still be one byte because the extra address bits are hidden
2537 in the chip address.
2539 - CONFIG_SYS_EEPROM_SIZE:
2540 The size in bytes of the EEPROM device.
2542 - CONFIG_ENV_EEPROM_IS_ON_I2C
2543 define this, if you have I2C and SPI activated, and your
2544 EEPROM, which holds the environment, is on the I2C bus.
2546 - CONFIG_I2C_ENV_EEPROM_BUS
2547 if you have an Environment on an EEPROM reached over
2548 I2C muxes, you can define here, how to reach this
2549 EEPROM. For example:
2551 #define CONFIG_I2C_ENV_EEPROM_BUS "pca9547:70:d\0"
2553 EEPROM which holds the environment, is reached over
2554 a pca9547 i2c mux with address 0x70, channel 3.
2556 - CONFIG_ENV_IS_IN_DATAFLASH:
2558 Define this if you have a DataFlash memory device which you
2559 want to use for the environment.
2561 - CONFIG_ENV_OFFSET:
2565 These three #defines specify the offset and size of the
2566 environment area within the total memory of your DataFlash placed
2567 at the specified address.
2569 - CONFIG_ENV_IS_IN_NAND:
2571 Define this if you have a NAND device which you want to use
2572 for the environment.
2574 - CONFIG_ENV_OFFSET:
2577 These two #defines specify the offset and size of the environment
2578 area within the first NAND device. CONFIG_ENV_OFFSET must be
2579 aligned to an erase block boundary.
2581 - CONFIG_ENV_OFFSET_REDUND (optional):
2583 This setting describes a second storage area of CONFIG_ENV_SIZE
2584 size used to hold a redundant copy of the environment data, so
2585 that there is a valid backup copy in case there is a power failure
2586 during a "saveenv" operation. CONFIG_ENV_OFFSET_RENDUND must be
2587 aligned to an erase block boundary.
2589 - CONFIG_ENV_RANGE (optional):
2591 Specifies the length of the region in which the environment
2592 can be written. This should be a multiple of the NAND device's
2593 block size. Specifying a range with more erase blocks than
2594 are needed to hold CONFIG_ENV_SIZE allows bad blocks within
2595 the range to be avoided.
2597 - CONFIG_ENV_OFFSET_OOB (optional):
2599 Enables support for dynamically retrieving the offset of the
2600 environment from block zero's out-of-band data. The
2601 "nand env.oob" command can be used to record this offset.
2602 Currently, CONFIG_ENV_OFFSET_REDUND is not supported when
2603 using CONFIG_ENV_OFFSET_OOB.
2605 - CONFIG_NAND_ENV_DST
2607 Defines address in RAM to which the nand_spl code should copy the
2608 environment. If redundant environment is used, it will be copied to
2609 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE.
2611 - CONFIG_SYS_SPI_INIT_OFFSET
2613 Defines offset to the initial SPI buffer area in DPRAM. The
2614 area is used at an early stage (ROM part) if the environment
2615 is configured to reside in the SPI EEPROM: We need a 520 byte
2616 scratch DPRAM area. It is used between the two initialization
2617 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems
2618 to be a good choice since it makes it far enough from the
2619 start of the data area as well as from the stack pointer.
2621 Please note that the environment is read-only until the monitor
2622 has been relocated to RAM and a RAM copy of the environment has been
2623 created; also, when using EEPROM you will have to use getenv_f()
2624 until then to read environment variables.
2626 The environment is protected by a CRC32 checksum. Before the monitor
2627 is relocated into RAM, as a result of a bad CRC you will be working
2628 with the compiled-in default environment - *silently*!!! [This is
2629 necessary, because the first environment variable we need is the
2630 "baudrate" setting for the console - if we have a bad CRC, we don't
2631 have any device yet where we could complain.]
2633 Note: once the monitor has been relocated, then it will complain if
2634 the default environment is used; a new CRC is computed as soon as you
2635 use the "saveenv" command to store a valid environment.
2637 - CONFIG_SYS_FAULT_ECHO_LINK_DOWN:
2638 Echo the inverted Ethernet link state to the fault LED.
2640 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR
2641 also needs to be defined.
2643 - CONFIG_SYS_FAULT_MII_ADDR:
2644 MII address of the PHY to check for the Ethernet link state.
2646 - CONFIG_NS16550_MIN_FUNCTIONS:
2647 Define this if you desire to only have use of the NS16550_init
2648 and NS16550_putc functions for the serial driver located at
2649 drivers/serial/ns16550.c. This option is useful for saving
2650 space for already greatly restricted images, including but not
2651 limited to NAND_SPL configurations.
2653 Low Level (hardware related) configuration options:
2654 ---------------------------------------------------
2656 - CONFIG_SYS_CACHELINE_SIZE:
2657 Cache Line Size of the CPU.
2659 - CONFIG_SYS_DEFAULT_IMMR:
2660 Default address of the IMMR after system reset.
2662 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU,
2663 and RPXsuper) to be able to adjust the position of
2664 the IMMR register after a reset.
2666 - Floppy Disk Support:
2667 CONFIG_SYS_FDC_DRIVE_NUMBER
2669 the default drive number (default value 0)
2671 CONFIG_SYS_ISA_IO_STRIDE
2673 defines the spacing between FDC chipset registers
2676 CONFIG_SYS_ISA_IO_OFFSET
2678 defines the offset of register from address. It
2679 depends on which part of the data bus is connected to
2680 the FDC chipset. (default value 0)
2682 If CONFIG_SYS_ISA_IO_STRIDE CONFIG_SYS_ISA_IO_OFFSET and
2683 CONFIG_SYS_FDC_DRIVE_NUMBER are undefined, they take their
2686 if CONFIG_SYS_FDC_HW_INIT is defined, then the function
2687 fdc_hw_init() is called at the beginning of the FDC
2688 setup. fdc_hw_init() must be provided by the board
2689 source code. It is used to make hardware dependant
2692 - CONFIG_SYS_IMMR: Physical address of the Internal Memory.
2693 DO NOT CHANGE unless you know exactly what you're
2694 doing! (11-4) [MPC8xx/82xx systems only]
2696 - CONFIG_SYS_INIT_RAM_ADDR:
2698 Start address of memory area that can be used for
2699 initial data and stack; please note that this must be
2700 writable memory that is working WITHOUT special
2701 initialization, i. e. you CANNOT use normal RAM which
2702 will become available only after programming the
2703 memory controller and running certain initialization
2706 U-Boot uses the following memory types:
2707 - MPC8xx and MPC8260: IMMR (internal memory of the CPU)
2708 - MPC824X: data cache
2709 - PPC4xx: data cache
2711 - CONFIG_SYS_GBL_DATA_OFFSET:
2713 Offset of the initial data structure in the memory
2714 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually
2715 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial
2716 data is located at the end of the available space
2717 (sometimes written as (CONFIG_SYS_INIT_RAM_SIZE -
2718 CONFIG_SYS_INIT_DATA_SIZE), and the initial stack is just
2719 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR +
2720 CONFIG_SYS_GBL_DATA_OFFSET) downward.
2723 On the MPC824X (or other systems that use the data
2724 cache for initial memory) the address chosen for
2725 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must
2726 point to an otherwise UNUSED address space between
2727 the top of RAM and the start of the PCI space.
2729 - CONFIG_SYS_SIUMCR: SIU Module Configuration (11-6)
2731 - CONFIG_SYS_SYPCR: System Protection Control (11-9)
2733 - CONFIG_SYS_TBSCR: Time Base Status and Control (11-26)
2735 - CONFIG_SYS_PISCR: Periodic Interrupt Status and Control (11-31)
2737 - CONFIG_SYS_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30)
2739 - CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27)
2741 - CONFIG_SYS_OR_TIMING_SDRAM:
2744 - CONFIG_SYS_MAMR_PTA:
2745 periodic timer for refresh
2747 - CONFIG_SYS_DER: Debug Event Register (37-47)
2749 - FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM,
2750 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP,
2751 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM,
2752 CONFIG_SYS_BR1_PRELIM:
2753 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
2755 - SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
2756 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM,
2757 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM:
2758 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
2760 - CONFIG_SYS_MAMR_PTA, CONFIG_SYS_MPTPR_2BK_4K, CONFIG_SYS_MPTPR_1BK_4K, CONFIG_SYS_MPTPR_2BK_8K,
2761 CONFIG_SYS_MPTPR_1BK_8K, CONFIG_SYS_MAMR_8COL, CONFIG_SYS_MAMR_9COL:
2762 Machine Mode Register and Memory Periodic Timer
2763 Prescaler definitions (SDRAM timing)
2765 - CONFIG_SYS_I2C_UCODE_PATCH, CONFIG_SYS_I2C_DPMEM_OFFSET [0x1FC0]:
2766 enable I2C microcode relocation patch (MPC8xx);
2767 define relocation offset in DPRAM [DSP2]
2769 - CONFIG_SYS_SMC_UCODE_PATCH, CONFIG_SYS_SMC_DPMEM_OFFSET [0x1FC0]:
2770 enable SMC microcode relocation patch (MPC8xx);
2771 define relocation offset in DPRAM [SMC1]
2773 - CONFIG_SYS_SPI_UCODE_PATCH, CONFIG_SYS_SPI_DPMEM_OFFSET [0x1FC0]:
2774 enable SPI microcode relocation patch (MPC8xx);
2775 define relocation offset in DPRAM [SCC4]
2777 - CONFIG_SYS_USE_OSCCLK:
2778 Use OSCM clock mode on MBX8xx board. Be careful,
2779 wrong setting might damage your board. Read
2780 doc/README.MBX before setting this variable!
2782 - CONFIG_SYS_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only)
2783 Offset of the bootmode word in DPRAM used by post
2784 (Power On Self Tests). This definition overrides
2785 #define'd default value in commproc.h resp.
2788 - CONFIG_SYS_PCI_SLV_MEM_LOCAL, CONFIG_SYS_PCI_SLV_MEM_BUS, CONFIG_SYS_PICMR0_MASK_ATTRIB,
2789 CONFIG_SYS_PCI_MSTR0_LOCAL, CONFIG_SYS_PCIMSK0_MASK, CONFIG_SYS_PCI_MSTR1_LOCAL,
2790 CONFIG_SYS_PCIMSK1_MASK, CONFIG_SYS_PCI_MSTR_MEM_LOCAL, CONFIG_SYS_PCI_MSTR_MEM_BUS,
2791 CONFIG_SYS_CPU_PCI_MEM_START, CONFIG_SYS_PCI_MSTR_MEM_SIZE, CONFIG_SYS_POCMR0_MASK_ATTRIB,
2792 CONFIG_SYS_PCI_MSTR_MEMIO_LOCAL, CONFIG_SYS_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START,
2793 CONFIG_SYS_PCI_MSTR_MEMIO_SIZE, CONFIG_SYS_POCMR1_MASK_ATTRIB, CONFIG_SYS_PCI_MSTR_IO_LOCAL,
2794 CONFIG_SYS_PCI_MSTR_IO_BUS, CONFIG_SYS_CPU_PCI_IO_START, CONFIG_SYS_PCI_MSTR_IO_SIZE,
2795 CONFIG_SYS_POCMR2_MASK_ATTRIB: (MPC826x only)
2796 Overrides the default PCI memory map in arch/powerpc/cpu/mpc8260/pci.c if set.
2798 - CONFIG_PCI_DISABLE_PCIE:
2799 Disable PCI-Express on systems where it is supported but not
2803 Chip has SRIO or not
2806 Board has SRIO 1 port available
2809 Board has SRIO 2 port available
2811 - CONFIG_SYS_SRIOn_MEM_VIRT:
2812 Virtual Address of SRIO port 'n' memory region
2814 - CONFIG_SYS_SRIOn_MEM_PHYS:
2815 Physical Address of SRIO port 'n' memory region
2817 - CONFIG_SYS_SRIOn_MEM_SIZE:
2818 Size of SRIO port 'n' memory region
2821 Get DDR timing information from an I2C EEPROM. Common
2822 with pluggable memory modules such as SODIMMs
2825 I2C address of the SPD EEPROM
2827 - CONFIG_SYS_SPD_BUS_NUM
2828 If SPD EEPROM is on an I2C bus other than the first
2829 one, specify here. Note that the value must resolve
2830 to something your driver can deal with.
2832 - CONFIG_SYS_83XX_DDR_USES_CS0
2833 Only for 83xx systems. If specified, then DDR should
2834 be configured using CS0 and CS1 instead of CS2 and CS3.
2836 - CONFIG_ETHER_ON_FEC[12]
2837 Define to enable FEC[12] on a 8xx series processor.
2839 - CONFIG_FEC[12]_PHY
2840 Define to the hardcoded PHY address which corresponds
2841 to the given FEC; i. e.
2842 #define CONFIG_FEC1_PHY 4
2843 means that the PHY with address 4 is connected to FEC1
2845 When set to -1, means to probe for first available.
2847 - CONFIG_FEC[12]_PHY_NORXERR
2848 The PHY does not have a RXERR line (RMII only).
2849 (so program the FEC to ignore it).
2852 Enable RMII mode for all FECs.
2853 Note that this is a global option, we can't
2854 have one FEC in standard MII mode and another in RMII mode.
2856 - CONFIG_CRC32_VERIFY
2857 Add a verify option to the crc32 command.
2860 => crc32 -v <address> <count> <crc32>
2862 Where address/count indicate a memory area
2863 and crc32 is the correct crc32 which the
2867 Add the "loopw" memory command. This only takes effect if
2868 the memory commands are activated globally (CONFIG_CMD_MEM).
2871 Add the "mdc" and "mwc" memory commands. These are cyclic
2876 This command will print 4 bytes (10,11,12,13) each 500 ms.
2878 => mwc.l 100 12345678 10
2879 This command will write 12345678 to address 100 all 10 ms.
2881 This only takes effect if the memory commands are activated
2882 globally (CONFIG_CMD_MEM).
2884 - CONFIG_SKIP_LOWLEVEL_INIT
2885 [ARM only] If this variable is defined, then certain
2886 low level initializations (like setting up the memory
2887 controller) are omitted and/or U-Boot does not
2888 relocate itself into RAM.
2890 Normally this variable MUST NOT be defined. The only
2891 exception is when U-Boot is loaded (to RAM) by some
2892 other boot loader or by a debugger which performs
2893 these initializations itself.
2896 Modifies the behaviour of start.S when compiling a loader
2897 that is executed before the actual U-Boot. E.g. when
2898 compiling a NAND SPL.
2900 Building the Software:
2901 ======================
2903 Building U-Boot has been tested in several native build environments
2904 and in many different cross environments. Of course we cannot support
2905 all possibly existing versions of cross development tools in all
2906 (potentially obsolete) versions. In case of tool chain problems we
2907 recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK)
2908 which is extensively used to build and test U-Boot.
2910 If you are not using a native environment, it is assumed that you
2911 have GNU cross compiling tools available in your path. In this case,
2912 you must set the environment variable CROSS_COMPILE in your shell.
2913 Note that no changes to the Makefile or any other source files are
2914 necessary. For example using the ELDK on a 4xx CPU, please enter:
2916 $ CROSS_COMPILE=ppc_4xx-
2917 $ export CROSS_COMPILE
2919 Note: If you wish to generate Windows versions of the utilities in
2920 the tools directory you can use the MinGW toolchain
2921 (http://www.mingw.org). Set your HOST tools to the MinGW
2922 toolchain and execute 'make tools'. For example:
2924 $ make HOSTCC=i586-mingw32msvc-gcc HOSTSTRIP=i586-mingw32msvc-strip tools
2926 Binaries such as tools/mkimage.exe will be created which can
2927 be executed on computers running Windows.
2929 U-Boot is intended to be simple to build. After installing the
2930 sources you must configure U-Boot for one specific board type. This
2935 where "NAME_config" is the name of one of the existing configu-
2936 rations; see the main Makefile for supported names.
2938 Note: for some board special configuration names may exist; check if
2939 additional information is available from the board vendor; for
2940 instance, the TQM823L systems are available without (standard)
2941 or with LCD support. You can select such additional "features"
2942 when choosing the configuration, i. e.
2945 - will configure for a plain TQM823L, i. e. no LCD support
2947 make TQM823L_LCD_config
2948 - will configure for a TQM823L with U-Boot console on LCD
2953 Finally, type "make all", and you should get some working U-Boot
2954 images ready for download to / installation on your system:
2956 - "u-boot.bin" is a raw binary image
2957 - "u-boot" is an image in ELF binary format
2958 - "u-boot.srec" is in Motorola S-Record format
2960 By default the build is performed locally and the objects are saved
2961 in the source directory. One of the two methods can be used to change
2962 this behavior and build U-Boot to some external directory:
2964 1. Add O= to the make command line invocations:
2966 make O=/tmp/build distclean
2967 make O=/tmp/build NAME_config
2968 make O=/tmp/build all
2970 2. Set environment variable BUILD_DIR to point to the desired location:
2972 export BUILD_DIR=/tmp/build
2977 Note that the command line "O=" setting overrides the BUILD_DIR environment
2981 Please be aware that the Makefiles assume you are using GNU make, so
2982 for instance on NetBSD you might need to use "gmake" instead of
2986 If the system board that you have is not listed, then you will need
2987 to port U-Boot to your hardware platform. To do this, follow these
2990 1. Add a new configuration option for your board to the toplevel
2991 "Makefile" and to the "MAKEALL" script, using the existing
2992 entries as examples. Note that here and at many other places
2993 boards and other names are listed in alphabetical sort order. Please
2995 2. Create a new directory to hold your board specific code. Add any
2996 files you need. In your board directory, you will need at least
2997 the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds".
2998 3. Create a new configuration file "include/configs/<board>.h" for
3000 3. If you're porting U-Boot to a new CPU, then also create a new
3001 directory to hold your CPU specific code. Add any files you need.
3002 4. Run "make <board>_config" with your new name.
3003 5. Type "make", and you should get a working "u-boot.srec" file
3004 to be installed on your target system.
3005 6. Debug and solve any problems that might arise.
3006 [Of course, this last step is much harder than it sounds.]
3009 Testing of U-Boot Modifications, Ports to New Hardware, etc.:
3010 ==============================================================
3012 If you have modified U-Boot sources (for instance added a new board
3013 or support for new devices, a new CPU, etc.) you are expected to
3014 provide feedback to the other developers. The feedback normally takes
3015 the form of a "patch", i. e. a context diff against a certain (latest
3016 official or latest in the git repository) version of U-Boot sources.
3018 But before you submit such a patch, please verify that your modifi-
3019 cation did not break existing code. At least make sure that *ALL* of
3020 the supported boards compile WITHOUT ANY compiler warnings. To do so,
3021 just run the "MAKEALL" script, which will configure and build U-Boot
3022 for ALL supported system. Be warned, this will take a while. You can
3023 select which (cross) compiler to use by passing a `CROSS_COMPILE'
3024 environment variable to the script, i. e. to use the ELDK cross tools
3027 CROSS_COMPILE=ppc_8xx- MAKEALL
3029 or to build on a native PowerPC system you can type
3031 CROSS_COMPILE=' ' MAKEALL
3033 When using the MAKEALL script, the default behaviour is to build
3034 U-Boot in the source directory. This location can be changed by
3035 setting the BUILD_DIR environment variable. Also, for each target
3036 built, the MAKEALL script saves two log files (<target>.ERR and
3037 <target>.MAKEALL) in the <source dir>/LOG directory. This default
3038 location can be changed by setting the MAKEALL_LOGDIR environment
3039 variable. For example:
3041 export BUILD_DIR=/tmp/build
3042 export MAKEALL_LOGDIR=/tmp/log
3043 CROSS_COMPILE=ppc_8xx- MAKEALL
3045 With the above settings build objects are saved in the /tmp/build,
3046 log files are saved in the /tmp/log and the source tree remains clean
3047 during the whole build process.
3050 See also "U-Boot Porting Guide" below.
3053 Monitor Commands - Overview:
3054 ============================
3056 go - start application at address 'addr'
3057 run - run commands in an environment variable
3058 bootm - boot application image from memory
3059 bootp - boot image via network using BootP/TFTP protocol
3060 tftpboot- boot image via network using TFTP protocol
3061 and env variables "ipaddr" and "serverip"
3062 (and eventually "gatewayip")
3063 rarpboot- boot image via network using RARP/TFTP protocol
3064 diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
3065 loads - load S-Record file over serial line
3066 loadb - load binary file over serial line (kermit mode)
3068 mm - memory modify (auto-incrementing)
3069 nm - memory modify (constant address)
3070 mw - memory write (fill)
3072 cmp - memory compare
3073 crc32 - checksum calculation
3074 i2c - I2C sub-system
3075 sspi - SPI utility commands
3076 base - print or set address offset
3077 printenv- print environment variables
3078 setenv - set environment variables
3079 saveenv - save environment variables to persistent storage
3080 protect - enable or disable FLASH write protection
3081 erase - erase FLASH memory
3082 flinfo - print FLASH memory information
3083 bdinfo - print Board Info structure
3084 iminfo - print header information for application image
3085 coninfo - print console devices and informations
3086 ide - IDE sub-system
3087 loop - infinite loop on address range
3088 loopw - infinite write loop on address range
3089 mtest - simple RAM test
3090 icache - enable or disable instruction cache
3091 dcache - enable or disable data cache
3092 reset - Perform RESET of the CPU
3093 echo - echo args to console
3094 version - print monitor version
3095 help - print online help
3096 ? - alias for 'help'
3099 Monitor Commands - Detailed Description:
3100 ========================================
3104 For now: just type "help <command>".
3107 Environment Variables:
3108 ======================
3110 U-Boot supports user configuration using Environment Variables which
3111 can be made persistent by saving to Flash memory.
3113 Environment Variables are set using "setenv", printed using
3114 "printenv", and saved to Flash using "saveenv". Using "setenv"
3115 without a value can be used to delete a variable from the
3116 environment. As long as you don't save the environment you are
3117 working with an in-memory copy. In case the Flash area containing the
3118 environment is erased by accident, a default environment is provided.
3120 Some configuration options can be set using Environment Variables.
3122 List of environment variables (most likely not complete):
3124 baudrate - see CONFIG_BAUDRATE
3126 bootdelay - see CONFIG_BOOTDELAY
3128 bootcmd - see CONFIG_BOOTCOMMAND
3130 bootargs - Boot arguments when booting an RTOS image
3132 bootfile - Name of the image to load with TFTP
3134 bootm_low - Memory range available for image processing in the bootm
3135 command can be restricted. This variable is given as
3136 a hexadecimal number and defines lowest address allowed
3137 for use by the bootm command. See also "bootm_size"
3138 environment variable. Address defined by "bootm_low" is
3139 also the base of the initial memory mapping for the Linux
3140 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ.
3142 bootm_size - Memory range available for image processing in the bootm
3143 command can be restricted. This variable is given as
3144 a hexadecimal number and defines the size of the region
3145 allowed for use by the bootm command. See also "bootm_low"
3146 environment variable.
3148 updatefile - Location of the software update file on a TFTP server, used
3149 by the automatic software update feature. Please refer to
3150 documentation in doc/README.update for more details.
3152 autoload - if set to "no" (any string beginning with 'n'),
3153 "bootp" will just load perform a lookup of the
3154 configuration from the BOOTP server, but not try to
3155 load any image using TFTP
3157 autostart - if set to "yes", an image loaded using the "bootp",
3158 "rarpboot", "tftpboot" or "diskboot" commands will
3159 be automatically started (by internally calling
3162 If set to "no", a standalone image passed to the
3163 "bootm" command will be copied to the load address
3164 (and eventually uncompressed), but NOT be started.
3165 This can be used to load and uncompress arbitrary
3168 i2cfast - (PPC405GP|PPC405EP only)
3169 if set to 'y' configures Linux I2C driver for fast
3170 mode (400kHZ). This environment variable is used in
3171 initialization code. So, for changes to be effective
3172 it must be saved and board must be reset.
3174 initrd_high - restrict positioning of initrd images:
3175 If this variable is not set, initrd images will be
3176 copied to the highest possible address in RAM; this
3177 is usually what you want since it allows for
3178 maximum initrd size. If for some reason you want to
3179 make sure that the initrd image is loaded below the
3180 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment
3181 variable to a value of "no" or "off" or "0".
3182 Alternatively, you can set it to a maximum upper
3183 address to use (U-Boot will still check that it
3184 does not overwrite the U-Boot stack and data).
3186 For instance, when you have a system with 16 MB
3187 RAM, and want to reserve 4 MB from use by Linux,
3188 you can do this by adding "mem=12M" to the value of
3189 the "bootargs" variable. However, now you must make
3190 sure that the initrd image is placed in the first
3191 12 MB as well - this can be done with
3193 setenv initrd_high 00c00000
3195 If you set initrd_high to 0xFFFFFFFF, this is an
3196 indication to U-Boot that all addresses are legal
3197 for the Linux kernel, including addresses in flash
3198 memory. In this case U-Boot will NOT COPY the
3199 ramdisk at all. This may be useful to reduce the
3200 boot time on your system, but requires that this
3201 feature is supported by your Linux kernel.
3203 ipaddr - IP address; needed for tftpboot command
3205 loadaddr - Default load address for commands like "bootp",
3206 "rarpboot", "tftpboot", "loadb" or "diskboot"
3208 loads_echo - see CONFIG_LOADS_ECHO
3210 serverip - TFTP server IP address; needed for tftpboot command
3212 bootretry - see CONFIG_BOOT_RETRY_TIME
3214 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
3216 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
3218 ethprime - When CONFIG_NET_MULTI is enabled controls which
3219 interface is used first.
3221 ethact - When CONFIG_NET_MULTI is enabled controls which
3222 interface is currently active. For example you
3223 can do the following
3225 => setenv ethact FEC
3226 => ping 192.168.0.1 # traffic sent on FEC
3227 => setenv ethact SCC
3228 => ping 10.0.0.1 # traffic sent on SCC
3230 ethrotate - When set to "no" U-Boot does not go through all
3231 available network interfaces.
3232 It just stays at the currently selected interface.
3234 netretry - When set to "no" each network operation will
3235 either succeed or fail without retrying.
3236 When set to "once" the network operation will
3237 fail when all the available network interfaces
3238 are tried once without success.
3239 Useful on scripts which control the retry operation
3242 npe_ucode - set load address for the NPE microcode
3244 tftpsrcport - If this is set, the value is used for TFTP's
3247 tftpdstport - If this is set, the value is used for TFTP's UDP
3248 destination port instead of the Well Know Port 69.
3250 tftpblocksize - Block size to use for TFTP transfers; if not set,
3251 we use the TFTP server's default block size
3253 tftptimeout - Retransmission timeout for TFTP packets (in milli-
3254 seconds, minimum value is 1000 = 1 second). Defines
3255 when a packet is considered to be lost so it has to
3256 be retransmitted. The default is 5000 = 5 seconds.
3257 Lowering this value may make downloads succeed
3258 faster in networks with high packet loss rates or
3259 with unreliable TFTP servers.
3261 vlan - When set to a value < 4095 the traffic over
3262 Ethernet is encapsulated/received over 802.1q
3265 The following environment variables may be used and automatically
3266 updated by the network boot commands ("bootp" and "rarpboot"),
3267 depending the information provided by your boot server:
3269 bootfile - see above
3270 dnsip - IP address of your Domain Name Server
3271 dnsip2 - IP address of your secondary Domain Name Server
3272 gatewayip - IP address of the Gateway (Router) to use
3273 hostname - Target hostname
3275 netmask - Subnet Mask
3276 rootpath - Pathname of the root filesystem on the NFS server
3277 serverip - see above
3280 There are two special Environment Variables:
3282 serial# - contains hardware identification information such
3283 as type string and/or serial number
3284 ethaddr - Ethernet address
3286 These variables can be set only once (usually during manufacturing of
3287 the board). U-Boot refuses to delete or overwrite these variables
3288 once they have been set once.
3291 Further special Environment Variables:
3293 ver - Contains the U-Boot version string as printed
3294 with the "version" command. This variable is
3295 readonly (see CONFIG_VERSION_VARIABLE).
3298 Please note that changes to some configuration parameters may take
3299 only effect after the next boot (yes, that's just like Windoze :-).
3302 Command Line Parsing:
3303 =====================
3305 There are two different command line parsers available with U-Boot:
3306 the old "simple" one, and the much more powerful "hush" shell:
3308 Old, simple command line parser:
3309 --------------------------------
3311 - supports environment variables (through setenv / saveenv commands)
3312 - several commands on one line, separated by ';'
3313 - variable substitution using "... ${name} ..." syntax
3314 - special characters ('$', ';') can be escaped by prefixing with '\',
3316 setenv bootcmd bootm \${address}
3317 - You can also escape text by enclosing in single apostrophes, for example:
3318 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
3323 - similar to Bourne shell, with control structures like
3324 if...then...else...fi, for...do...done; while...do...done,
3325 until...do...done, ...
3326 - supports environment ("global") variables (through setenv / saveenv
3327 commands) and local shell variables (through standard shell syntax
3328 "name=value"); only environment variables can be used with "run"
3334 (1) If a command line (or an environment variable executed by a "run"
3335 command) contains several commands separated by semicolon, and
3336 one of these commands fails, then the remaining commands will be
3339 (2) If you execute several variables with one call to run (i. e.
3340 calling run with a list of variables as arguments), any failing
3341 command will cause "run" to terminate, i. e. the remaining
3342 variables are not executed.
3344 Note for Redundant Ethernet Interfaces:
3345 =======================================
3347 Some boards come with redundant Ethernet interfaces; U-Boot supports
3348 such configurations and is capable of automatic selection of a
3349 "working" interface when needed. MAC assignment works as follows:
3351 Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
3352 MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
3353 "eth1addr" (=>eth1), "eth2addr", ...
3355 If the network interface stores some valid MAC address (for instance
3356 in SROM), this is used as default address if there is NO correspon-
3357 ding setting in the environment; if the corresponding environment
3358 variable is set, this overrides the settings in the card; that means:
3360 o If the SROM has a valid MAC address, and there is no address in the
3361 environment, the SROM's address is used.
3363 o If there is no valid address in the SROM, and a definition in the
3364 environment exists, then the value from the environment variable is
3367 o If both the SROM and the environment contain a MAC address, and
3368 both addresses are the same, this MAC address is used.
3370 o If both the SROM and the environment contain a MAC address, and the
3371 addresses differ, the value from the environment is used and a
3374 o If neither SROM nor the environment contain a MAC address, an error
3377 If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses
3378 will be programmed into hardware as part of the initialization process. This
3379 may be skipped by setting the appropriate 'ethmacskip' environment variable.
3380 The naming convention is as follows:
3381 "ethmacskip" (=>eth0), "eth1macskip" (=>eth1) etc.
3386 U-Boot is capable of booting (and performing other auxiliary operations on)
3387 images in two formats:
3389 New uImage format (FIT)
3390 -----------------------
3392 Flexible and powerful format based on Flattened Image Tree -- FIT (similar
3393 to Flattened Device Tree). It allows the use of images with multiple
3394 components (several kernels, ramdisks, etc.), with contents protected by
3395 SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory.
3401 Old image format is based on binary files which can be basically anything,
3402 preceded by a special header; see the definitions in include/image.h for
3403 details; basically, the header defines the following image properties:
3405 * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
3406 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
3407 LynxOS, pSOS, QNX, RTEMS, INTEGRITY;
3408 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS,
3410 * Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86,
3411 IA64, MIPS, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
3412 Currently supported: ARM, AVR32, Intel x86, MIPS, Nios II, PowerPC).
3413 * Compression Type (uncompressed, gzip, bzip2)
3419 The header is marked by a special Magic Number, and both the header
3420 and the data portions of the image are secured against corruption by
3427 Although U-Boot should support any OS or standalone application
3428 easily, the main focus has always been on Linux during the design of
3431 U-Boot includes many features that so far have been part of some
3432 special "boot loader" code within the Linux kernel. Also, any
3433 "initrd" images to be used are no longer part of one big Linux image;
3434 instead, kernel and "initrd" are separate images. This implementation
3435 serves several purposes:
3437 - the same features can be used for other OS or standalone
3438 applications (for instance: using compressed images to reduce the
3439 Flash memory footprint)
3441 - it becomes much easier to port new Linux kernel versions because
3442 lots of low-level, hardware dependent stuff are done by U-Boot
3444 - the same Linux kernel image can now be used with different "initrd"
3445 images; of course this also means that different kernel images can
3446 be run with the same "initrd". This makes testing easier (you don't
3447 have to build a new "zImage.initrd" Linux image when you just
3448 change a file in your "initrd"). Also, a field-upgrade of the
3449 software is easier now.
3455 Porting Linux to U-Boot based systems:
3456 ---------------------------------------
3458 U-Boot cannot save you from doing all the necessary modifications to
3459 configure the Linux device drivers for use with your target hardware
3460 (no, we don't intend to provide a full virtual machine interface to
3463 But now you can ignore ALL boot loader code (in arch/powerpc/mbxboot).
3465 Just make sure your machine specific header file (for instance
3466 include/asm-ppc/tqm8xx.h) includes the same definition of the Board
3467 Information structure as we define in include/asm-<arch>/u-boot.h,
3468 and make sure that your definition of IMAP_ADDR uses the same value
3469 as your U-Boot configuration in CONFIG_SYS_IMMR.
3472 Configuring the Linux kernel:
3473 -----------------------------
3475 No specific requirements for U-Boot. Make sure you have some root
3476 device (initial ramdisk, NFS) for your target system.
3479 Building a Linux Image:
3480 -----------------------
3482 With U-Boot, "normal" build targets like "zImage" or "bzImage" are
3483 not used. If you use recent kernel source, a new build target
3484 "uImage" will exist which automatically builds an image usable by
3485 U-Boot. Most older kernels also have support for a "pImage" target,
3486 which was introduced for our predecessor project PPCBoot and uses a
3487 100% compatible format.
3496 The "uImage" build target uses a special tool (in 'tools/mkimage') to
3497 encapsulate a compressed Linux kernel image with header information,
3498 CRC32 checksum etc. for use with U-Boot. This is what we are doing:
3500 * build a standard "vmlinux" kernel image (in ELF binary format):
3502 * convert the kernel into a raw binary image:
3504 ${CROSS_COMPILE}-objcopy -O binary \
3505 -R .note -R .comment \
3506 -S vmlinux linux.bin
3508 * compress the binary image:
3512 * package compressed binary image for U-Boot:
3514 mkimage -A ppc -O linux -T kernel -C gzip \
3515 -a 0 -e 0 -n "Linux Kernel Image" \
3516 -d linux.bin.gz uImage
3519 The "mkimage" tool can also be used to create ramdisk images for use
3520 with U-Boot, either separated from the Linux kernel image, or
3521 combined into one file. "mkimage" encapsulates the images with a 64
3522 byte header containing information about target architecture,
3523 operating system, image type, compression method, entry points, time
3524 stamp, CRC32 checksums, etc.
3526 "mkimage" can be called in two ways: to verify existing images and
3527 print the header information, or to build new images.
3529 In the first form (with "-l" option) mkimage lists the information
3530 contained in the header of an existing U-Boot image; this includes
3531 checksum verification:
3533 tools/mkimage -l image
3534 -l ==> list image header information
3536 The second form (with "-d" option) is used to build a U-Boot image
3537 from a "data file" which is used as image payload:
3539 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
3540 -n name -d data_file image
3541 -A ==> set architecture to 'arch'
3542 -O ==> set operating system to 'os'
3543 -T ==> set image type to 'type'
3544 -C ==> set compression type 'comp'
3545 -a ==> set load address to 'addr' (hex)
3546 -e ==> set entry point to 'ep' (hex)
3547 -n ==> set image name to 'name'
3548 -d ==> use image data from 'datafile'
3550 Right now, all Linux kernels for PowerPC systems use the same load
3551 address (0x00000000), but the entry point address depends on the
3554 - 2.2.x kernels have the entry point at 0x0000000C,
3555 - 2.3.x and later kernels have the entry point at 0x00000000.
3557 So a typical call to build a U-Boot image would read:
3559 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
3560 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
3561 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz \
3562 > examples/uImage.TQM850L
3563 Image Name: 2.4.4 kernel for TQM850L
3564 Created: Wed Jul 19 02:34:59 2000
3565 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3566 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
3567 Load Address: 0x00000000
3568 Entry Point: 0x00000000
3570 To verify the contents of the image (or check for corruption):
3572 -> tools/mkimage -l examples/uImage.TQM850L
3573 Image Name: 2.4.4 kernel for TQM850L
3574 Created: Wed Jul 19 02:34:59 2000
3575 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3576 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
3577 Load Address: 0x00000000
3578 Entry Point: 0x00000000
3580 NOTE: for embedded systems where boot time is critical you can trade
3581 speed for memory and install an UNCOMPRESSED image instead: this
3582 needs more space in Flash, but boots much faster since it does not
3583 need to be uncompressed:
3585 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz
3586 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
3587 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
3588 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux \
3589 > examples/uImage.TQM850L-uncompressed
3590 Image Name: 2.4.4 kernel for TQM850L
3591 Created: Wed Jul 19 02:34:59 2000
3592 Image Type: PowerPC Linux Kernel Image (uncompressed)
3593 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
3594 Load Address: 0x00000000
3595 Entry Point: 0x00000000
3598 Similar you can build U-Boot images from a 'ramdisk.image.gz' file
3599 when your kernel is intended to use an initial ramdisk:
3601 -> tools/mkimage -n 'Simple Ramdisk Image' \
3602 > -A ppc -O linux -T ramdisk -C gzip \
3603 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
3604 Image Name: Simple Ramdisk Image
3605 Created: Wed Jan 12 14:01:50 2000
3606 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
3607 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
3608 Load Address: 0x00000000
3609 Entry Point: 0x00000000
3612 Installing a Linux Image:
3613 -------------------------
3615 To downloading a U-Boot image over the serial (console) interface,
3616 you must convert the image to S-Record format:
3618 objcopy -I binary -O srec examples/image examples/image.srec
3620 The 'objcopy' does not understand the information in the U-Boot
3621 image header, so the resulting S-Record file will be relative to
3622 address 0x00000000. To load it to a given address, you need to
3623 specify the target address as 'offset' parameter with the 'loads'
3626 Example: install the image to address 0x40100000 (which on the
3627 TQM8xxL is in the first Flash bank):
3629 => erase 40100000 401FFFFF
3635 ## Ready for S-Record download ...
3636 ~>examples/image.srec
3637 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
3639 15989 15990 15991 15992
3640 [file transfer complete]
3642 ## Start Addr = 0x00000000
3645 You can check the success of the download using the 'iminfo' command;
3646 this includes a checksum verification so you can be sure no data
3647 corruption happened:
3651 ## Checking Image at 40100000 ...
3652 Image Name: 2.2.13 for initrd on TQM850L
3653 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3654 Data Size: 335725 Bytes = 327 kB = 0 MB
3655 Load Address: 00000000
3656 Entry Point: 0000000c
3657 Verifying Checksum ... OK
3663 The "bootm" command is used to boot an application that is stored in
3664 memory (RAM or Flash). In case of a Linux kernel image, the contents
3665 of the "bootargs" environment variable is passed to the kernel as
3666 parameters. You can check and modify this variable using the
3667 "printenv" and "setenv" commands:
3670 => printenv bootargs
3671 bootargs=root=/dev/ram
3673 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
3675 => printenv bootargs
3676 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
3679 ## Booting Linux kernel at 40020000 ...
3680 Image Name: 2.2.13 for NFS on TQM850L
3681 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3682 Data Size: 381681 Bytes = 372 kB = 0 MB
3683 Load Address: 00000000
3684 Entry Point: 0000000c
3685 Verifying Checksum ... OK
3686 Uncompressing Kernel Image ... OK
3687 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
3688 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
3689 time_init: decrementer frequency = 187500000/60
3690 Calibrating delay loop... 49.77 BogoMIPS
3691 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
3694 If you want to boot a Linux kernel with initial RAM disk, you pass
3695 the memory addresses of both the kernel and the initrd image (PPBCOOT
3696 format!) to the "bootm" command:
3698 => imi 40100000 40200000
3700 ## Checking Image at 40100000 ...
3701 Image Name: 2.2.13 for initrd on TQM850L
3702 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3703 Data Size: 335725 Bytes = 327 kB = 0 MB
3704 Load Address: 00000000
3705 Entry Point: 0000000c
3706 Verifying Checksum ... OK
3708 ## Checking Image at 40200000 ...
3709 Image Name: Simple Ramdisk Image
3710 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
3711 Data Size: 566530 Bytes = 553 kB = 0 MB
3712 Load Address: 00000000
3713 Entry Point: 00000000
3714 Verifying Checksum ... OK
3716 => bootm 40100000 40200000
3717 ## Booting Linux kernel at 40100000 ...
3718 Image Name: 2.2.13 for initrd on TQM850L
3719 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3720 Data Size: 335725 Bytes = 327 kB = 0 MB
3721 Load Address: 00000000
3722 Entry Point: 0000000c
3723 Verifying Checksum ... OK
3724 Uncompressing Kernel Image ... OK
3725 ## Loading RAMDisk Image at 40200000 ...
3726 Image Name: Simple Ramdisk Image
3727 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
3728 Data Size: 566530 Bytes = 553 kB = 0 MB
3729 Load Address: 00000000
3730 Entry Point: 00000000
3731 Verifying Checksum ... OK
3732 Loading Ramdisk ... OK
3733 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
3734 Boot arguments: root=/dev/ram
3735 time_init: decrementer frequency = 187500000/60
3736 Calibrating delay loop... 49.77 BogoMIPS
3738 RAMDISK: Compressed image found at block 0
3739 VFS: Mounted root (ext2 filesystem).
3743 Boot Linux and pass a flat device tree:
3746 First, U-Boot must be compiled with the appropriate defines. See the section
3747 titled "Linux Kernel Interface" above for a more in depth explanation. The
3748 following is an example of how to start a kernel and pass an updated
3754 oft=oftrees/mpc8540ads.dtb
3755 => tftp $oftaddr $oft
3756 Speed: 1000, full duplex
3758 TFTP from server 192.168.1.1; our IP address is 192.168.1.101
3759 Filename 'oftrees/mpc8540ads.dtb'.
3760 Load address: 0x300000
3763 Bytes transferred = 4106 (100a hex)
3764 => tftp $loadaddr $bootfile
3765 Speed: 1000, full duplex
3767 TFTP from server 192.168.1.1; our IP address is 192.168.1.2
3769 Load address: 0x200000
3770 Loading:############
3772 Bytes transferred = 1029407 (fb51f hex)
3777 => bootm $loadaddr - $oftaddr
3778 ## Booting image at 00200000 ...
3779 Image Name: Linux-2.6.17-dirty
3780 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3781 Data Size: 1029343 Bytes = 1005.2 kB
3782 Load Address: 00000000
3783 Entry Point: 00000000
3784 Verifying Checksum ... OK
3785 Uncompressing Kernel Image ... OK
3786 Booting using flat device tree at 0x300000
3787 Using MPC85xx ADS machine description
3788 Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb
3792 More About U-Boot Image Types:
3793 ------------------------------
3795 U-Boot supports the following image types:
3797 "Standalone Programs" are directly runnable in the environment
3798 provided by U-Boot; it is expected that (if they behave
3799 well) you can continue to work in U-Boot after return from
3800 the Standalone Program.
3801 "OS Kernel Images" are usually images of some Embedded OS which
3802 will take over control completely. Usually these programs
3803 will install their own set of exception handlers, device
3804 drivers, set up the MMU, etc. - this means, that you cannot
3805 expect to re-enter U-Boot except by resetting the CPU.
3806 "RAMDisk Images" are more or less just data blocks, and their
3807 parameters (address, size) are passed to an OS kernel that is
3809 "Multi-File Images" contain several images, typically an OS
3810 (Linux) kernel image and one or more data images like
3811 RAMDisks. This construct is useful for instance when you want
3812 to boot over the network using BOOTP etc., where the boot
3813 server provides just a single image file, but you want to get
3814 for instance an OS kernel and a RAMDisk image.
3816 "Multi-File Images" start with a list of image sizes, each
3817 image size (in bytes) specified by an "uint32_t" in network
3818 byte order. This list is terminated by an "(uint32_t)0".
3819 Immediately after the terminating 0 follow the images, one by
3820 one, all aligned on "uint32_t" boundaries (size rounded up to
3821 a multiple of 4 bytes).
3823 "Firmware Images" are binary images containing firmware (like
3824 U-Boot or FPGA images) which usually will be programmed to
3827 "Script files" are command sequences that will be executed by
3828 U-Boot's command interpreter; this feature is especially
3829 useful when you configure U-Boot to use a real shell (hush)
3830 as command interpreter.
3836 One of the features of U-Boot is that you can dynamically load and
3837 run "standalone" applications, which can use some resources of
3838 U-Boot like console I/O functions or interrupt services.
3840 Two simple examples are included with the sources:
3845 'examples/hello_world.c' contains a small "Hello World" Demo
3846 application; it is automatically compiled when you build U-Boot.
3847 It's configured to run at address 0x00040004, so you can play with it
3851 ## Ready for S-Record download ...
3852 ~>examples/hello_world.srec
3853 1 2 3 4 5 6 7 8 9 10 11 ...
3854 [file transfer complete]
3856 ## Start Addr = 0x00040004
3858 => go 40004 Hello World! This is a test.
3859 ## Starting application at 0x00040004 ...
3870 Hit any key to exit ...
3872 ## Application terminated, rc = 0x0
3874 Another example, which demonstrates how to register a CPM interrupt
3875 handler with the U-Boot code, can be found in 'examples/timer.c'.
3876 Here, a CPM timer is set up to generate an interrupt every second.
3877 The interrupt service routine is trivial, just printing a '.'
3878 character, but this is just a demo program. The application can be
3879 controlled by the following keys:
3881 ? - print current values og the CPM Timer registers
3882 b - enable interrupts and start timer
3883 e - stop timer and disable interrupts
3884 q - quit application
3887 ## Ready for S-Record download ...
3888 ~>examples/timer.srec
3889 1 2 3 4 5 6 7 8 9 10 11 ...
3890 [file transfer complete]
3892 ## Start Addr = 0x00040004
3895 ## Starting application at 0x00040004 ...
3898 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
3901 [q, b, e, ?] Set interval 1000000 us
3904 [q, b, e, ?] ........
3905 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
3908 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
3911 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
3914 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
3916 [q, b, e, ?] ...Stopping timer
3918 [q, b, e, ?] ## Application terminated, rc = 0x0
3924 Over time, many people have reported problems when trying to use the
3925 "minicom" terminal emulation program for serial download. I (wd)
3926 consider minicom to be broken, and recommend not to use it. Under
3927 Unix, I recommend to use C-Kermit for general purpose use (and
3928 especially for kermit binary protocol download ("loadb" command), and
3929 use "cu" for S-Record download ("loads" command).
3931 Nevertheless, if you absolutely want to use it try adding this
3932 configuration to your "File transfer protocols" section:
3934 Name Program Name U/D FullScr IO-Red. Multi
3935 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
3936 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
3942 Starting at version 0.9.2, U-Boot supports NetBSD both as host
3943 (build U-Boot) and target system (boots NetBSD/mpc8xx).
3945 Building requires a cross environment; it is known to work on
3946 NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
3947 need gmake since the Makefiles are not compatible with BSD make).
3948 Note that the cross-powerpc package does not install include files;
3949 attempting to build U-Boot will fail because <machine/ansi.h> is
3950 missing. This file has to be installed and patched manually:
3952 # cd /usr/pkg/cross/powerpc-netbsd/include
3954 # ln -s powerpc machine
3955 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
3956 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
3958 Native builds *don't* work due to incompatibilities between native
3959 and U-Boot include files.
3961 Booting assumes that (the first part of) the image booted is a
3962 stage-2 loader which in turn loads and then invokes the kernel
3963 proper. Loader sources will eventually appear in the NetBSD source
3964 tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
3965 meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz
3968 Implementation Internals:
3969 =========================
3971 The following is not intended to be a complete description of every
3972 implementation detail. However, it should help to understand the
3973 inner workings of U-Boot and make it easier to port it to custom
3977 Initial Stack, Global Data:
3978 ---------------------------
3980 The implementation of U-Boot is complicated by the fact that U-Boot
3981 starts running out of ROM (flash memory), usually without access to
3982 system RAM (because the memory controller is not initialized yet).
3983 This means that we don't have writable Data or BSS segments, and BSS
3984 is not initialized as zero. To be able to get a C environment working
3985 at all, we have to allocate at least a minimal stack. Implementation
3986 options for this are defined and restricted by the CPU used: Some CPU
3987 models provide on-chip memory (like the IMMR area on MPC8xx and
3988 MPC826x processors), on others (parts of) the data cache can be
3989 locked as (mis-) used as memory, etc.
3991 Chris Hallinan posted a good summary of these issues to the
3992 U-Boot mailing list:
3994 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
3995 From: "Chris Hallinan" <clh@net1plus.com>
3996 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
3999 Correct me if I'm wrong, folks, but the way I understand it
4000 is this: Using DCACHE as initial RAM for Stack, etc, does not
4001 require any physical RAM backing up the cache. The cleverness
4002 is that the cache is being used as a temporary supply of
4003 necessary storage before the SDRAM controller is setup. It's
4004 beyond the scope of this list to explain the details, but you
4005 can see how this works by studying the cache architecture and
4006 operation in the architecture and processor-specific manuals.
4008 OCM is On Chip Memory, which I believe the 405GP has 4K. It
4009 is another option for the system designer to use as an
4010 initial stack/RAM area prior to SDRAM being available. Either
4011 option should work for you. Using CS 4 should be fine if your
4012 board designers haven't used it for something that would
4013 cause you grief during the initial boot! It is frequently not
4016 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere
4017 with your processor/board/system design. The default value
4018 you will find in any recent u-boot distribution in
4019 walnut.h should work for you. I'd set it to a value larger
4020 than your SDRAM module. If you have a 64MB SDRAM module, set
4021 it above 400_0000. Just make sure your board has no resources
4022 that are supposed to respond to that address! That code in
4023 start.S has been around a while and should work as is when
4024 you get the config right.
4029 It is essential to remember this, since it has some impact on the C
4030 code for the initialization procedures:
4032 * Initialized global data (data segment) is read-only. Do not attempt
4035 * Do not use any uninitialized global data (or implicitely initialized
4036 as zero data - BSS segment) at all - this is undefined, initiali-
4037 zation is performed later (when relocating to RAM).
4039 * Stack space is very limited. Avoid big data buffers or things like
4042 Having only the stack as writable memory limits means we cannot use
4043 normal global data to share information beween the code. But it
4044 turned out that the implementation of U-Boot can be greatly
4045 simplified by making a global data structure (gd_t) available to all
4046 functions. We could pass a pointer to this data as argument to _all_
4047 functions, but this would bloat the code. Instead we use a feature of
4048 the GCC compiler (Global Register Variables) to share the data: we
4049 place a pointer (gd) to the global data into a register which we
4050 reserve for this purpose.
4052 When choosing a register for such a purpose we are restricted by the
4053 relevant (E)ABI specifications for the current architecture, and by
4054 GCC's implementation.
4056 For PowerPC, the following registers have specific use:
4058 R2: reserved for system use
4059 R3-R4: parameter passing and return values
4060 R5-R10: parameter passing
4061 R13: small data area pointer
4065 (U-Boot also uses R12 as internal GOT pointer. r12
4066 is a volatile register so r12 needs to be reset when
4067 going back and forth between asm and C)
4069 ==> U-Boot will use R2 to hold a pointer to the global data
4071 Note: on PPC, we could use a static initializer (since the
4072 address of the global data structure is known at compile time),
4073 but it turned out that reserving a register results in somewhat
4074 smaller code - although the code savings are not that big (on
4075 average for all boards 752 bytes for the whole U-Boot image,
4076 624 text + 127 data).
4078 On Blackfin, the normal C ABI (except for P3) is followed as documented here:
4079 http://docs.blackfin.uclinux.org/doku.php?id=application_binary_interface
4081 ==> U-Boot will use P3 to hold a pointer to the global data
4083 On ARM, the following registers are used:
4085 R0: function argument word/integer result
4086 R1-R3: function argument word
4088 R10: stack limit (used only if stack checking if enabled)
4089 R11: argument (frame) pointer
4090 R12: temporary workspace
4093 R15: program counter
4095 ==> U-Boot will use R8 to hold a pointer to the global data
4097 On Nios II, the ABI is documented here:
4098 http://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf
4100 ==> U-Boot will use gp to hold a pointer to the global data
4102 Note: on Nios II, we give "-G0" option to gcc and don't use gp
4103 to access small data sections, so gp is free.
4105 NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope,
4106 or current versions of GCC may "optimize" the code too much.
4111 U-Boot runs in system state and uses physical addresses, i.e. the
4112 MMU is not used either for address mapping nor for memory protection.
4114 The available memory is mapped to fixed addresses using the memory
4115 controller. In this process, a contiguous block is formed for each
4116 memory type (Flash, SDRAM, SRAM), even when it consists of several
4117 physical memory banks.
4119 U-Boot is installed in the first 128 kB of the first Flash bank (on
4120 TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
4121 booting and sizing and initializing DRAM, the code relocates itself
4122 to the upper end of DRAM. Immediately below the U-Boot code some
4123 memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN
4124 configuration setting]. Below that, a structure with global Board
4125 Info data is placed, followed by the stack (growing downward).
4127 Additionally, some exception handler code is copied to the low 8 kB
4128 of DRAM (0x00000000 ... 0x00001FFF).
4130 So a typical memory configuration with 16 MB of DRAM could look like
4133 0x0000 0000 Exception Vector code
4136 0x0000 2000 Free for Application Use
4142 0x00FB FF20 Monitor Stack (Growing downward)
4143 0x00FB FFAC Board Info Data and permanent copy of global data
4144 0x00FC 0000 Malloc Arena
4147 0x00FE 0000 RAM Copy of Monitor Code
4148 ... eventually: LCD or video framebuffer
4149 ... eventually: pRAM (Protected RAM - unchanged by reset)
4150 0x00FF FFFF [End of RAM]
4153 System Initialization:
4154 ----------------------
4156 In the reset configuration, U-Boot starts at the reset entry point
4157 (on most PowerPC systems at address 0x00000100). Because of the reset
4158 configuration for CS0# this is a mirror of the onboard Flash memory.
4159 To be able to re-map memory U-Boot then jumps to its link address.
4160 To be able to implement the initialization code in C, a (small!)
4161 initial stack is set up in the internal Dual Ported RAM (in case CPUs
4162 which provide such a feature like MPC8xx or MPC8260), or in a locked
4163 part of the data cache. After that, U-Boot initializes the CPU core,
4164 the caches and the SIU.
4166 Next, all (potentially) available memory banks are mapped using a
4167 preliminary mapping. For example, we put them on 512 MB boundaries
4168 (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
4169 on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
4170 programmed for SDRAM access. Using the temporary configuration, a
4171 simple memory test is run that determines the size of the SDRAM
4174 When there is more than one SDRAM bank, and the banks are of
4175 different size, the largest is mapped first. For equal size, the first
4176 bank (CS2#) is mapped first. The first mapping is always for address
4177 0x00000000, with any additional banks following immediately to create
4178 contiguous memory starting from 0.
4180 Then, the monitor installs itself at the upper end of the SDRAM area
4181 and allocates memory for use by malloc() and for the global Board
4182 Info data; also, the exception vector code is copied to the low RAM
4183 pages, and the final stack is set up.
4185 Only after this relocation will you have a "normal" C environment;
4186 until that you are restricted in several ways, mostly because you are
4187 running from ROM, and because the code will have to be relocated to a
4191 U-Boot Porting Guide:
4192 ----------------------
4194 [Based on messages by Jerry Van Baren in the U-Boot-Users mailing
4198 int main(int argc, char *argv[])
4200 sighandler_t no_more_time;
4202 signal(SIGALRM, no_more_time);
4203 alarm(PROJECT_DEADLINE - toSec (3 * WEEK));
4205 if (available_money > available_manpower) {
4206 Pay consultant to port U-Boot;
4210 Download latest U-Boot source;
4212 Subscribe to u-boot mailing list;
4215 email("Hi, I am new to U-Boot, how do I get started?");
4218 Read the README file in the top level directory;
4219 Read http://www.denx.de/twiki/bin/view/DULG/Manual;
4220 Read applicable doc/*.README;
4221 Read the source, Luke;
4222 /* find . -name "*.[chS]" | xargs grep -i <keyword> */
4225 if (available_money > toLocalCurrency ($2500))
4228 Add a lot of aggravation and time;
4230 if (a similar board exists) { /* hopefully... */
4231 cp -a board/<similar> board/<myboard>
4232 cp include/configs/<similar>.h include/configs/<myboard>.h
4234 Create your own board support subdirectory;
4235 Create your own board include/configs/<myboard>.h file;
4237 Edit new board/<myboard> files
4238 Edit new include/configs/<myboard>.h
4243 Add / modify source code;
4247 email("Hi, I am having problems...");
4249 Send patch file to the U-Boot email list;
4250 if (reasonable critiques)
4251 Incorporate improvements from email list code review;
4253 Defend code as written;
4259 void no_more_time (int sig)
4268 All contributions to U-Boot should conform to the Linux kernel
4269 coding style; see the file "Documentation/CodingStyle" and the script
4270 "scripts/Lindent" in your Linux kernel source directory. In sources
4271 originating from U-Boot a style corresponding to "Lindent -pcs" (adding
4272 spaces before parameters to function calls) is actually used.
4274 Source files originating from a different project (for example the
4275 MTD subsystem) are generally exempt from these guidelines and are not
4276 reformated to ease subsequent migration to newer versions of those
4279 Please note that U-Boot is implemented in C (and to some small parts in
4280 Assembler); no C++ is used, so please do not use C++ style comments (//)
4283 Please also stick to the following formatting rules:
4284 - remove any trailing white space
4285 - use TAB characters for indentation, not spaces
4286 - make sure NOT to use DOS '\r\n' line feeds
4287 - do not add more than 2 empty lines to source files
4288 - do not add trailing empty lines to source files
4290 Submissions which do not conform to the standards may be returned
4291 with a request to reformat the changes.
4297 Since the number of patches for U-Boot is growing, we need to
4298 establish some rules. Submissions which do not conform to these rules
4299 may be rejected, even when they contain important and valuable stuff.
4301 Please see http://www.denx.de/wiki/U-Boot/Patches for details.
4303 Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>;
4304 see http://lists.denx.de/mailman/listinfo/u-boot
4306 When you send a patch, please include the following information with
4309 * For bug fixes: a description of the bug and how your patch fixes
4310 this bug. Please try to include a way of demonstrating that the
4311 patch actually fixes something.
4313 * For new features: a description of the feature and your
4316 * A CHANGELOG entry as plaintext (separate from the patch)
4318 * For major contributions, your entry to the CREDITS file
4320 * When you add support for a new board, don't forget to add this
4321 board to the MAKEALL script, too.
4323 * If your patch adds new configuration options, don't forget to
4324 document these in the README file.
4326 * The patch itself. If you are using git (which is *strongly*
4327 recommended) you can easily generate the patch using the
4328 "git-format-patch". If you then use "git-send-email" to send it to
4329 the U-Boot mailing list, you will avoid most of the common problems
4330 with some other mail clients.
4332 If you cannot use git, use "diff -purN OLD NEW". If your version of
4333 diff does not support these options, then get the latest version of
4336 The current directory when running this command shall be the parent
4337 directory of the U-Boot source tree (i. e. please make sure that
4338 your patch includes sufficient directory information for the
4341 We prefer patches as plain text. MIME attachments are discouraged,
4342 and compressed attachments must not be used.
4344 * If one logical set of modifications affects or creates several
4345 files, all these changes shall be submitted in a SINGLE patch file.
4347 * Changesets that contain different, unrelated modifications shall be
4348 submitted as SEPARATE patches, one patch per changeset.
4353 * Before sending the patch, run the MAKEALL script on your patched
4354 source tree and make sure that no errors or warnings are reported
4355 for any of the boards.
4357 * Keep your modifications to the necessary minimum: A patch
4358 containing several unrelated changes or arbitrary reformats will be
4359 returned with a request to re-formatting / split it.
4361 * If you modify existing code, make sure that your new code does not
4362 add to the memory footprint of the code ;-) Small is beautiful!
4363 When adding new features, these should compile conditionally only
4364 (using #ifdef), and the resulting code with the new feature
4365 disabled must not need more memory than the old code without your
4368 * Remember that there is a size limit of 100 kB per message on the
4369 u-boot mailing list. Bigger patches will be moderated. If they are
4370 reasonable and not too big, they will be acknowledged. But patches
4371 bigger than the size limit should be avoided.
projects / platform / kernel / u-boot.git / blob