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 - Marvell Family Member
323 CONFIG_SYS_MVFS - define it if you want to enable
324 multiple fs option at one time
325 for marvell soc family
327 - MPC824X Family Member (if CONFIG_MPC824X is defined)
328 Define exactly one of
329 CONFIG_MPC8240, CONFIG_MPC8245
331 - 8xx CPU Options: (if using an MPC8xx CPU)
332 CONFIG_8xx_GCLK_FREQ - deprecated: CPU clock if
333 get_gclk_freq() cannot work
334 e.g. if there is no 32KHz
335 reference PIT/RTC clock
336 CONFIG_8xx_OSCLK - PLL input clock (either EXTCLK
339 - 859/866/885 CPU options: (if using a MPC859 or MPC866 or MPC885 CPU):
340 CONFIG_SYS_8xx_CPUCLK_MIN
341 CONFIG_SYS_8xx_CPUCLK_MAX
342 CONFIG_8xx_CPUCLK_DEFAULT
343 See doc/README.MPC866
345 CONFIG_SYS_MEASURE_CPUCLK
347 Define this to measure the actual CPU clock instead
348 of relying on the correctness of the configured
349 values. Mostly useful for board bringup to make sure
350 the PLL is locked at the intended frequency. Note
351 that this requires a (stable) reference clock (32 kHz
352 RTC clock or CONFIG_SYS_8XX_XIN)
354 CONFIG_SYS_DELAYED_ICACHE
356 Define this option if you want to enable the
357 ICache only when Code runs from RAM.
359 - Intel Monahans options:
360 CONFIG_SYS_MONAHANS_RUN_MODE_OSC_RATIO
362 Defines the Monahans run mode to oscillator
363 ratio. Valid values are 8, 16, 24, 31. The core
364 frequency is this value multiplied by 13 MHz.
366 CONFIG_SYS_MONAHANS_TURBO_RUN_MODE_RATIO
368 Defines the Monahans turbo mode to oscillator
369 ratio. Valid values are 1 (default if undefined) and
370 2. The core frequency as calculated above is multiplied
373 - Linux Kernel Interface:
376 U-Boot stores all clock information in Hz
377 internally. For binary compatibility with older Linux
378 kernels (which expect the clocks passed in the
379 bd_info data to be in MHz) the environment variable
380 "clocks_in_mhz" can be defined so that U-Boot
381 converts clock data to MHZ before passing it to the
383 When CONFIG_CLOCKS_IN_MHZ is defined, a definition of
384 "clocks_in_mhz=1" is automatically included in the
387 CONFIG_MEMSIZE_IN_BYTES [relevant for MIPS only]
389 When transferring memsize parameter to linux, some versions
390 expect it to be in bytes, others in MB.
391 Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes.
395 New kernel versions are expecting firmware settings to be
396 passed using flattened device trees (based on open firmware
400 * New libfdt-based support
401 * Adds the "fdt" command
402 * The bootm command automatically updates the fdt
404 OF_CPU - The proper name of the cpus node (only required for
405 MPC512X and MPC5xxx based boards).
406 OF_SOC - The proper name of the soc node (only required for
407 MPC512X and MPC5xxx based boards).
408 OF_TBCLK - The timebase frequency.
409 OF_STDOUT_PATH - The path to the console device
411 boards with QUICC Engines require OF_QE to set UCC MAC
414 CONFIG_OF_BOARD_SETUP
416 Board code has addition modification that it wants to make
417 to the flat device tree before handing it off to the kernel
421 This define fills in the correct boot CPU in the boot
422 param header, the default value is zero if undefined.
426 U-Boot can detect if an IDE device is present or not.
427 If not, and this new config option is activated, U-Boot
428 removes the ATA node from the DTS before booting Linux,
429 so the Linux IDE driver does not probe the device and
430 crash. This is needed for buggy hardware (uc101) where
431 no pull down resistor is connected to the signal IDE5V_DD7.
433 - vxWorks boot parameters:
435 bootvx constructs a valid bootline using the following
436 environments variables: bootfile, ipaddr, serverip, hostname.
437 It loads the vxWorks image pointed bootfile.
439 CONFIG_SYS_VXWORKS_BOOT_DEVICE - The vxworks device name
440 CONFIG_SYS_VXWORKS_MAC_PTR - Ethernet 6 byte MA -address
441 CONFIG_SYS_VXWORKS_SERVERNAME - Name of the server
442 CONFIG_SYS_VXWORKS_BOOT_ADDR - Address of boot parameters
444 CONFIG_SYS_VXWORKS_ADD_PARAMS
446 Add it at the end of the bootline. E.g "u=username pw=secret"
448 Note: If a "bootargs" environment is defined, it will overwride
449 the defaults discussed just above.
454 Define this if you want support for Amba PrimeCell PL010 UARTs.
458 Define this if you want support for Amba PrimeCell PL011 UARTs.
462 If you have Amba PrimeCell PL011 UARTs, set this variable to
463 the clock speed of the UARTs.
467 If you have Amba PrimeCell PL010 or PL011 UARTs on your board,
468 define this to a list of base addresses for each (supported)
469 port. See e.g. include/configs/versatile.h
473 Depending on board, define exactly one serial port
474 (like CONFIG_8xx_CONS_SMC1, CONFIG_8xx_CONS_SMC2,
475 CONFIG_8xx_CONS_SCC1, ...), or switch off the serial
476 console by defining CONFIG_8xx_CONS_NONE
478 Note: if CONFIG_8xx_CONS_NONE is defined, the serial
479 port routines must be defined elsewhere
480 (i.e. serial_init(), serial_getc(), ...)
483 Enables console device for a color framebuffer. Needs following
484 defines (cf. smiLynxEM, i8042, board/eltec/bab7xx)
485 VIDEO_FB_LITTLE_ENDIAN graphic memory organisation
487 VIDEO_HW_RECTFILL graphic chip supports
490 VIDEO_HW_BITBLT graphic chip supports
491 bit-blit (cf. smiLynxEM)
492 VIDEO_VISIBLE_COLS visible pixel columns
494 VIDEO_VISIBLE_ROWS visible pixel rows
495 VIDEO_PIXEL_SIZE bytes per pixel
496 VIDEO_DATA_FORMAT graphic data format
497 (0-5, cf. cfb_console.c)
498 VIDEO_FB_ADRS framebuffer address
499 VIDEO_KBD_INIT_FCT keyboard int fct
500 (i.e. i8042_kbd_init())
501 VIDEO_TSTC_FCT test char fct
503 VIDEO_GETC_FCT get char fct
505 CONFIG_CONSOLE_CURSOR cursor drawing on/off
506 (requires blink timer
508 CONFIG_SYS_CONSOLE_BLINK_COUNT blink interval (cf. i8042.c)
509 CONFIG_CONSOLE_TIME display time/date info in
511 (requires CONFIG_CMD_DATE)
512 CONFIG_VIDEO_LOGO display Linux logo in
514 CONFIG_VIDEO_BMP_LOGO use bmp_logo.h instead of
515 linux_logo.h for logo.
516 Requires CONFIG_VIDEO_LOGO
517 CONFIG_CONSOLE_EXTRA_INFO
518 additional board info beside
521 When CONFIG_CFB_CONSOLE is defined, video console is
522 default i/o. Serial console can be forced with
523 environment 'console=serial'.
525 When CONFIG_SILENT_CONSOLE is defined, all console
526 messages (by U-Boot and Linux!) can be silenced with
527 the "silent" environment variable. See
528 doc/README.silent for more information.
531 CONFIG_BAUDRATE - in bps
532 Select one of the baudrates listed in
533 CONFIG_SYS_BAUDRATE_TABLE, see below.
534 CONFIG_SYS_BRGCLK_PRESCALE, baudrate prescale
536 - Console Rx buffer length
537 With CONFIG_SYS_SMC_RXBUFLEN it is possible to define
538 the maximum receive buffer length for the SMC.
539 This option is actual only for 82xx and 8xx possible.
540 If using CONFIG_SYS_SMC_RXBUFLEN also CONFIG_SYS_MAXIDLE
541 must be defined, to setup the maximum idle timeout for
544 - Boot Delay: CONFIG_BOOTDELAY - in seconds
545 Delay before automatically booting the default image;
546 set to -1 to disable autoboot.
548 See doc/README.autoboot for these options that
549 work with CONFIG_BOOTDELAY. None are required.
550 CONFIG_BOOT_RETRY_TIME
551 CONFIG_BOOT_RETRY_MIN
552 CONFIG_AUTOBOOT_KEYED
553 CONFIG_AUTOBOOT_PROMPT
554 CONFIG_AUTOBOOT_DELAY_STR
555 CONFIG_AUTOBOOT_STOP_STR
556 CONFIG_AUTOBOOT_DELAY_STR2
557 CONFIG_AUTOBOOT_STOP_STR2
558 CONFIG_ZERO_BOOTDELAY_CHECK
559 CONFIG_RESET_TO_RETRY
563 Only needed when CONFIG_BOOTDELAY is enabled;
564 define a command string that is automatically executed
565 when no character is read on the console interface
566 within "Boot Delay" after reset.
569 This can be used to pass arguments to the bootm
570 command. The value of CONFIG_BOOTARGS goes into the
571 environment value "bootargs".
573 CONFIG_RAMBOOT and CONFIG_NFSBOOT
574 The value of these goes into the environment as
575 "ramboot" and "nfsboot" respectively, and can be used
576 as a convenience, when switching between booting from
582 When this option is #defined, the existence of the
583 environment variable "preboot" will be checked
584 immediately before starting the CONFIG_BOOTDELAY
585 countdown and/or running the auto-boot command resp.
586 entering interactive mode.
588 This feature is especially useful when "preboot" is
589 automatically generated or modified. For an example
590 see the LWMON board specific code: here "preboot" is
591 modified when the user holds down a certain
592 combination of keys on the (special) keyboard when
595 - Serial Download Echo Mode:
597 If defined to 1, all characters received during a
598 serial download (using the "loads" command) are
599 echoed back. This might be needed by some terminal
600 emulations (like "cu"), but may as well just take
601 time on others. This setting #define's the initial
602 value of the "loads_echo" environment variable.
604 - Kgdb Serial Baudrate: (if CONFIG_CMD_KGDB is defined)
606 Select one of the baudrates listed in
607 CONFIG_SYS_BAUDRATE_TABLE, see below.
610 Monitor commands can be included or excluded
611 from the build by using the #include files
612 "config_cmd_all.h" and #undef'ing unwanted
613 commands, or using "config_cmd_default.h"
614 and augmenting with additional #define's
617 The default command configuration includes all commands
618 except those marked below with a "*".
620 CONFIG_CMD_ASKENV * ask for env variable
621 CONFIG_CMD_BDI bdinfo
622 CONFIG_CMD_BEDBUG * Include BedBug Debugger
623 CONFIG_CMD_BMP * BMP support
624 CONFIG_CMD_BSP * Board specific commands
625 CONFIG_CMD_BOOTD bootd
626 CONFIG_CMD_CACHE * icache, dcache
627 CONFIG_CMD_CONSOLE coninfo
628 CONFIG_CMD_DATE * support for RTC, date/time...
629 CONFIG_CMD_DHCP * DHCP support
630 CONFIG_CMD_DIAG * Diagnostics
631 CONFIG_CMD_DS4510 * ds4510 I2C gpio commands
632 CONFIG_CMD_DS4510_INFO * ds4510 I2C info command
633 CONFIG_CMD_DS4510_MEM * ds4510 I2C eeprom/sram commansd
634 CONFIG_CMD_DS4510_RST * ds4510 I2C rst command
635 CONFIG_CMD_DTT * Digital Therm and Thermostat
636 CONFIG_CMD_ECHO echo arguments
637 CONFIG_CMD_EDITENV edit env variable
638 CONFIG_CMD_EEPROM * EEPROM read/write support
639 CONFIG_CMD_ELF * bootelf, bootvx
640 CONFIG_CMD_SAVEENV saveenv
641 CONFIG_CMD_FDC * Floppy Disk Support
642 CONFIG_CMD_FAT * FAT partition support
643 CONFIG_CMD_FDOS * Dos diskette Support
644 CONFIG_CMD_FLASH flinfo, erase, protect
645 CONFIG_CMD_FPGA FPGA device initialization support
646 CONFIG_CMD_HWFLOW * RTS/CTS hw flow control
647 CONFIG_CMD_I2C * I2C serial bus support
648 CONFIG_CMD_IDE * IDE harddisk support
649 CONFIG_CMD_IMI iminfo
650 CONFIG_CMD_IMLS List all found images
651 CONFIG_CMD_IMMAP * IMMR dump support
652 CONFIG_CMD_IRQ * irqinfo
653 CONFIG_CMD_ITEST Integer/string test of 2 values
654 CONFIG_CMD_JFFS2 * JFFS2 Support
655 CONFIG_CMD_KGDB * kgdb
656 CONFIG_CMD_LOADB loadb
657 CONFIG_CMD_LOADS loads
658 CONFIG_CMD_MD5SUM print md5 message digest
659 (requires CONFIG_CMD_MEMORY and CONFIG_MD5)
660 CONFIG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base,
662 CONFIG_CMD_MISC Misc functions like sleep etc
663 CONFIG_CMD_MMC * MMC memory mapped support
664 CONFIG_CMD_MII * MII utility commands
665 CONFIG_CMD_MTDPARTS * MTD partition support
666 CONFIG_CMD_NAND * NAND support
667 CONFIG_CMD_NET bootp, tftpboot, rarpboot
668 CONFIG_CMD_PCA953X * PCA953x I2C gpio commands
669 CONFIG_CMD_PCA953X_INFO * PCA953x I2C gpio info command
670 CONFIG_CMD_PCI * pciinfo
671 CONFIG_CMD_PCMCIA * PCMCIA support
672 CONFIG_CMD_PING * send ICMP ECHO_REQUEST to network
674 CONFIG_CMD_PORTIO * Port I/O
675 CONFIG_CMD_REGINFO * Register dump
676 CONFIG_CMD_RUN run command in env variable
677 CONFIG_CMD_SAVES * save S record dump
678 CONFIG_CMD_SCSI * SCSI Support
679 CONFIG_CMD_SDRAM * print SDRAM configuration information
680 (requires CONFIG_CMD_I2C)
681 CONFIG_CMD_SETGETDCR Support for DCR Register access
683 CONFIG_CMD_SHA1SUM print sha1 memory digest
684 (requires CONFIG_CMD_MEMORY)
685 CONFIG_CMD_SOURCE "source" command Support
686 CONFIG_CMD_SPI * SPI serial bus support
687 CONFIG_CMD_USB * USB support
688 CONFIG_CMD_VFD * VFD support (TRAB)
689 CONFIG_CMD_CDP * Cisco Discover Protocol support
690 CONFIG_CMD_FSL * Microblaze FSL support
693 EXAMPLE: If you want all functions except of network
694 support you can write:
696 #include "config_cmd_all.h"
697 #undef CONFIG_CMD_NET
700 fdt (flattened device tree) command: CONFIG_OF_LIBFDT
702 Note: Don't enable the "icache" and "dcache" commands
703 (configuration option CONFIG_CMD_CACHE) unless you know
704 what you (and your U-Boot users) are doing. Data
705 cache cannot be enabled on systems like the 8xx or
706 8260 (where accesses to the IMMR region must be
707 uncached), and it cannot be disabled on all other
708 systems where we (mis-) use the data cache to hold an
709 initial stack and some data.
712 XXX - this list needs to get updated!
716 If this variable is defined, it enables watchdog
717 support. There must be support in the platform specific
718 code for a watchdog. For the 8xx and 8260 CPUs, the
719 SIU Watchdog feature is enabled in the SYPCR
723 CONFIG_VERSION_VARIABLE
724 If this variable is defined, an environment variable
725 named "ver" is created by U-Boot showing the U-Boot
726 version as printed by the "version" command.
727 This variable is readonly.
731 When CONFIG_CMD_DATE is selected, the type of the RTC
732 has to be selected, too. Define exactly one of the
735 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx
736 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC
737 CONFIG_RTC_MC13783 - use MC13783 RTC
738 CONFIG_RTC_MC146818 - use MC146818 RTC
739 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC
740 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC
741 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC
742 CONFIG_RTC_DS164x - use Dallas DS164x RTC
743 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC
744 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC
745 CONFIG_SYS_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337
747 Note that if the RTC uses I2C, then the I2C interface
748 must also be configured. See I2C Support, below.
751 CONFIG_PCA953X - use NXP's PCA953X series I2C GPIO
752 CONFIG_PCA953X_INFO - enable pca953x info command
754 The CONFIG_SYS_I2C_PCA953X_WIDTH option specifies a list of
755 chip-ngpio pairs that tell the PCA953X driver the number of
756 pins supported by a particular chip.
758 Note that if the GPIO device uses I2C, then the I2C interface
759 must also be configured. See I2C Support, below.
763 When CONFIG_TIMESTAMP is selected, the timestamp
764 (date and time) of an image is printed by image
765 commands like bootm or iminfo. This option is
766 automatically enabled when you select CONFIG_CMD_DATE .
769 CONFIG_MAC_PARTITION and/or CONFIG_DOS_PARTITION
770 and/or CONFIG_ISO_PARTITION and/or CONFIG_EFI_PARTITION
772 If IDE or SCSI support is enabled (CONFIG_CMD_IDE or
773 CONFIG_CMD_SCSI) you must configure support for at
774 least one partition type as well.
777 CONFIG_IDE_RESET_ROUTINE - this is defined in several
778 board configurations files but used nowhere!
780 CONFIG_IDE_RESET - is this is defined, IDE Reset will
781 be performed by calling the function
782 ide_set_reset(int reset)
783 which has to be defined in a board specific file
788 Set this to enable ATAPI support.
793 Set this to enable support for disks larger than 137GB
794 Also look at CONFIG_SYS_64BIT_LBA.
795 Whithout these , LBA48 support uses 32bit variables and will 'only'
796 support disks up to 2.1TB.
798 CONFIG_SYS_64BIT_LBA:
799 When enabled, makes the IDE subsystem use 64bit sector addresses.
803 At the moment only there is only support for the
804 SYM53C8XX SCSI controller; define
805 CONFIG_SCSI_SYM53C8XX to enable it.
807 CONFIG_SYS_SCSI_MAX_LUN [8], CONFIG_SYS_SCSI_MAX_SCSI_ID [7] and
808 CONFIG_SYS_SCSI_MAX_DEVICE [CONFIG_SYS_SCSI_MAX_SCSI_ID *
809 CONFIG_SYS_SCSI_MAX_LUN] can be adjusted to define the
810 maximum numbers of LUNs, SCSI ID's and target
812 CONFIG_SYS_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz)
814 - NETWORK Support (PCI):
816 Support for Intel 8254x gigabit chips.
818 CONFIG_E1000_FALLBACK_MAC
819 default MAC for empty EEPROM after production.
822 Support for Intel 82557/82559/82559ER chips.
823 Optional CONFIG_EEPRO100_SROM_WRITE enables EEPROM
824 write routine for first time initialisation.
827 Support for Digital 2114x chips.
828 Optional CONFIG_TULIP_SELECT_MEDIA for board specific
829 modem chip initialisation (KS8761/QS6611).
832 Support for National dp83815 chips.
835 Support for National dp8382[01] gigabit chips.
837 - NETWORK Support (other):
839 CONFIG_DRIVER_AT91EMAC
840 Support for AT91RM9200 EMAC.
843 Define this to use reduced MII inteface
845 CONFIG_DRIVER_AT91EMAC_QUIET
846 If this defined, the driver is quiet.
847 The driver doen't show link status messages.
849 CONFIG_DRIVER_LAN91C96
850 Support for SMSC's LAN91C96 chips.
853 Define this to hold the physical address
854 of the LAN91C96's I/O space
856 CONFIG_LAN91C96_USE_32_BIT
857 Define this to enable 32 bit addressing
859 CONFIG_DRIVER_SMC91111
860 Support for SMSC's LAN91C111 chip
863 Define this to hold the physical address
864 of the device (I/O space)
866 CONFIG_SMC_USE_32_BIT
867 Define this if data bus is 32 bits
869 CONFIG_SMC_USE_IOFUNCS
870 Define this to use i/o functions instead of macros
871 (some hardware wont work with macros)
874 Support for Faraday's FTGMAC100 Gigabit SoC Ethernet
876 CONFIG_FTGMAC100_EGIGA
877 Define this to use GE link update with gigabit PHY.
878 Define this if FTGMAC100 is connected to gigabit PHY.
879 If your system has 10/100 PHY only, it might not occur
880 wrong behavior. Because PHY usually return timeout or
881 useless data when polling gigabit status and gigabit
882 control registers. This behavior won't affect the
883 correctnessof 10/100 link speed update.
886 Support for SMSC's LAN911x and LAN921x chips
889 Define this to hold the physical address
890 of the device (I/O space)
892 CONFIG_SMC911X_32_BIT
893 Define this if data bus is 32 bits
895 CONFIG_SMC911X_16_BIT
896 Define this if data bus is 16 bits. If your processor
897 automatically converts one 32 bit word to two 16 bit
898 words you may also try CONFIG_SMC911X_32_BIT.
901 Support for Renesas on-chip Ethernet controller
903 CONFIG_SH_ETHER_USE_PORT
904 Define the number of ports to be used
906 CONFIG_SH_ETHER_PHY_ADDR
907 Define the ETH PHY's address
909 CONFIG_SH_ETHER_CACHE_WRITEBACK
910 If this option is set, the driver enables cache flush.
913 At the moment only the UHCI host controller is
914 supported (PIP405, MIP405, MPC5200); define
915 CONFIG_USB_UHCI to enable it.
916 define CONFIG_USB_KEYBOARD to enable the USB Keyboard
917 and define CONFIG_USB_STORAGE to enable the USB
920 Supported are USB Keyboards and USB Floppy drives
922 MPC5200 USB requires additional defines:
924 for 528 MHz Clock: 0x0001bbbb
928 for differential drivers: 0x00001000
929 for single ended drivers: 0x00005000
930 for differential drivers on PSC3: 0x00000100
931 for single ended drivers on PSC3: 0x00004100
932 CONFIG_SYS_USB_EVENT_POLL
933 May be defined to allow interrupt polling
934 instead of using asynchronous interrupts
937 Define the below if you wish to use the USB console.
938 Once firmware is rebuilt from a serial console issue the
939 command "setenv stdin usbtty; setenv stdout usbtty" and
940 attach your USB cable. The Unix command "dmesg" should print
941 it has found a new device. The environment variable usbtty
942 can be set to gserial or cdc_acm to enable your device to
943 appear to a USB host as a Linux gserial device or a
944 Common Device Class Abstract Control Model serial device.
945 If you select usbtty = gserial you should be able to enumerate
947 # modprobe usbserial vendor=0xVendorID product=0xProductID
948 else if using cdc_acm, simply setting the environment
949 variable usbtty to be cdc_acm should suffice. The following
950 might be defined in YourBoardName.h
953 Define this to build a UDC device
956 Define this to have a tty type of device available to
957 talk to the UDC device
959 CONFIG_SYS_CONSOLE_IS_IN_ENV
960 Define this if you want stdin, stdout &/or stderr to
964 CONFIG_SYS_USB_EXTC_CLK 0xBLAH
965 Derive USB clock from external clock "blah"
966 - CONFIG_SYS_USB_EXTC_CLK 0x02
968 CONFIG_SYS_USB_BRG_CLK 0xBLAH
969 Derive USB clock from brgclk
970 - CONFIG_SYS_USB_BRG_CLK 0x04
972 If you have a USB-IF assigned VendorID then you may wish to
973 define your own vendor specific values either in BoardName.h
974 or directly in usbd_vendor_info.h. If you don't define
975 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME,
976 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot
977 should pretend to be a Linux device to it's target host.
979 CONFIG_USBD_MANUFACTURER
980 Define this string as the name of your company for
981 - CONFIG_USBD_MANUFACTURER "my company"
983 CONFIG_USBD_PRODUCT_NAME
984 Define this string as the name of your product
985 - CONFIG_USBD_PRODUCT_NAME "acme usb device"
988 Define this as your assigned Vendor ID from the USB
989 Implementors Forum. This *must* be a genuine Vendor ID
990 to avoid polluting the USB namespace.
991 - CONFIG_USBD_VENDORID 0xFFFF
993 CONFIG_USBD_PRODUCTID
994 Define this as the unique Product ID
996 - CONFIG_USBD_PRODUCTID 0xFFFF
1000 The MMC controller on the Intel PXA is supported. To
1001 enable this define CONFIG_MMC. The MMC can be
1002 accessed from the boot prompt by mapping the device
1003 to physical memory similar to flash. Command line is
1004 enabled with CONFIG_CMD_MMC. The MMC driver also works with
1005 the FAT fs. This is enabled with CONFIG_CMD_FAT.
1007 - Journaling Flash filesystem support:
1008 CONFIG_JFFS2_NAND, CONFIG_JFFS2_NAND_OFF, CONFIG_JFFS2_NAND_SIZE,
1009 CONFIG_JFFS2_NAND_DEV
1010 Define these for a default partition on a NAND device
1012 CONFIG_SYS_JFFS2_FIRST_SECTOR,
1013 CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS
1014 Define these for a default partition on a NOR device
1016 CONFIG_SYS_JFFS_CUSTOM_PART
1017 Define this to create an own partition. You have to provide a
1018 function struct part_info* jffs2_part_info(int part_num)
1020 If you define only one JFFS2 partition you may also want to
1021 #define CONFIG_SYS_JFFS_SINGLE_PART 1
1022 to disable the command chpart. This is the default when you
1023 have not defined a custom partition
1028 Define this to enable standard (PC-Style) keyboard
1032 Standard PC keyboard driver with US (is default) and
1033 GERMAN key layout (switch via environment 'keymap=de') support.
1034 Export function i8042_kbd_init, i8042_tstc and i8042_getc
1035 for cfb_console. Supports cursor blinking.
1040 Define this to enable video support (for output to
1043 CONFIG_VIDEO_CT69000
1045 Enable Chips & Technologies 69000 Video chip
1047 CONFIG_VIDEO_SMI_LYNXEM
1048 Enable Silicon Motion SMI 712/710/810 Video chip. The
1049 video output is selected via environment 'videoout'
1050 (1 = LCD and 2 = CRT). If videoout is undefined, CRT is
1053 For the CT69000 and SMI_LYNXEM drivers, videomode is
1054 selected via environment 'videomode'. Two different ways
1056 - "videomode=num" 'num' is a standard LiLo mode numbers.
1057 Following standard modes are supported (* is default):
1059 Colors 640x480 800x600 1024x768 1152x864 1280x1024
1060 -------------+---------------------------------------------
1061 8 bits | 0x301* 0x303 0x305 0x161 0x307
1062 15 bits | 0x310 0x313 0x316 0x162 0x319
1063 16 bits | 0x311 0x314 0x317 0x163 0x31A
1064 24 bits | 0x312 0x315 0x318 ? 0x31B
1065 -------------+---------------------------------------------
1066 (i.e. setenv videomode 317; saveenv; reset;)
1068 - "videomode=bootargs" all the video parameters are parsed
1069 from the bootargs. (See drivers/video/videomodes.c)
1072 CONFIG_VIDEO_SED13806
1073 Enable Epson SED13806 driver. This driver supports 8bpp
1074 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP
1075 or CONFIG_VIDEO_SED13806_16BPP
1078 Enable the Freescale DIU video driver. Reference boards for
1079 SOCs that have a DIU should define this macro to enable DIU
1080 support, and should also define these other macros:
1086 CONFIG_VIDEO_SW_CURSOR
1087 CONFIG_VGA_AS_SINGLE_DEVICE
1089 CONFIG_VIDEO_BMP_LOGO
1091 The DIU driver will look for the 'monitor' environment variable,
1092 and if defined, enable the DIU as a console during boot. This
1093 variable should be set to one of these values:
1095 '0' Output video to the DVI connector
1096 '1' Output video to the LVDS connector
1097 '2' Output video to the Dual-Link LVDS connector
1102 Define this to enable a custom keyboard support.
1103 This simply calls drv_keyboard_init() which must be
1104 defined in your board-specific files.
1105 The only board using this so far is RBC823.
1107 - LCD Support: CONFIG_LCD
1109 Define this to enable LCD support (for output to LCD
1110 display); also select one of the supported displays
1111 by defining one of these:
1115 HITACHI TX09D70VM1CCA, 3.5", 240x320.
1117 CONFIG_NEC_NL6448AC33:
1119 NEC NL6448AC33-18. Active, color, single scan.
1121 CONFIG_NEC_NL6448BC20
1123 NEC NL6448BC20-08. 6.5", 640x480.
1124 Active, color, single scan.
1126 CONFIG_NEC_NL6448BC33_54
1128 NEC NL6448BC33-54. 10.4", 640x480.
1129 Active, color, single scan.
1133 Sharp 320x240. Active, color, single scan.
1134 It isn't 16x9, and I am not sure what it is.
1136 CONFIG_SHARP_LQ64D341
1138 Sharp LQ64D341 display, 640x480.
1139 Active, color, single scan.
1143 HLD1045 display, 640x480.
1144 Active, color, single scan.
1148 Optrex CBL50840-2 NF-FW 99 22 M5
1150 Hitachi LMG6912RPFC-00T
1154 320x240. Black & white.
1156 Normally display is black on white background; define
1157 CONFIG_SYS_WHITE_ON_BLACK to get it inverted.
1159 - Splash Screen Support: CONFIG_SPLASH_SCREEN
1161 If this option is set, the environment is checked for
1162 a variable "splashimage". If found, the usual display
1163 of logo, copyright and system information on the LCD
1164 is suppressed and the BMP image at the address
1165 specified in "splashimage" is loaded instead. The
1166 console is redirected to the "nulldev", too. This
1167 allows for a "silent" boot where a splash screen is
1168 loaded very quickly after power-on.
1170 CONFIG_SPLASH_SCREEN_ALIGN
1172 If this option is set the splash image can be freely positioned
1173 on the screen. Environment variable "splashpos" specifies the
1174 position as "x,y". If a positive number is given it is used as
1175 number of pixel from left/top. If a negative number is given it
1176 is used as number of pixel from right/bottom. You can also
1177 specify 'm' for centering the image.
1180 setenv splashpos m,m
1181 => image at center of screen
1183 setenv splashpos 30,20
1184 => image at x = 30 and y = 20
1186 setenv splashpos -10,m
1187 => vertically centered image
1188 at x = dspWidth - bmpWidth - 9
1190 - Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP
1192 If this option is set, additionally to standard BMP
1193 images, gzipped BMP images can be displayed via the
1194 splashscreen support or the bmp command.
1196 - Run length encoded BMP image (RLE8) support: CONFIG_VIDEO_BMP_RLE8
1198 If this option is set, 8-bit RLE compressed BMP images
1199 can be displayed via the splashscreen support or the
1202 - Compression support:
1205 If this option is set, support for bzip2 compressed
1206 images is included. If not, only uncompressed and gzip
1207 compressed images are supported.
1209 NOTE: the bzip2 algorithm requires a lot of RAM, so
1210 the malloc area (as defined by CONFIG_SYS_MALLOC_LEN) should
1215 If this option is set, support for lzma compressed
1218 Note: The LZMA algorithm adds between 2 and 4KB of code and it
1219 requires an amount of dynamic memory that is given by the
1222 (1846 + 768 << (lc + lp)) * sizeof(uint16)
1224 Where lc and lp stand for, respectively, Literal context bits
1225 and Literal pos bits.
1227 This value is upper-bounded by 14MB in the worst case. Anyway,
1228 for a ~4MB large kernel image, we have lc=3 and lp=0 for a
1229 total amount of (1846 + 768 << (3 + 0)) * 2 = ~41KB... that is
1230 a very small buffer.
1232 Use the lzmainfo tool to determinate the lc and lp values and
1233 then calculate the amount of needed dynamic memory (ensuring
1234 the appropriate CONFIG_SYS_MALLOC_LEN value).
1239 The address of PHY on MII bus.
1241 CONFIG_PHY_CLOCK_FREQ (ppc4xx)
1243 The clock frequency of the MII bus
1247 If this option is set, support for speed/duplex
1248 detection of gigabit PHY is included.
1250 CONFIG_PHY_RESET_DELAY
1252 Some PHY like Intel LXT971A need extra delay after
1253 reset before any MII register access is possible.
1254 For such PHY, set this option to the usec delay
1255 required. (minimum 300usec for LXT971A)
1257 CONFIG_PHY_CMD_DELAY (ppc4xx)
1259 Some PHY like Intel LXT971A need extra delay after
1260 command issued before MII status register can be read
1270 Define a default value for Ethernet address to use
1271 for the respective Ethernet interface, in case this
1272 is not determined automatically.
1277 Define a default value for the IP address to use for
1278 the default Ethernet interface, in case this is not
1279 determined through e.g. bootp.
1281 - Server IP address:
1284 Defines a default value for the IP address of a TFTP
1285 server to contact when using the "tftboot" command.
1287 CONFIG_KEEP_SERVERADDR
1289 Keeps the server's MAC address, in the env 'serveraddr'
1290 for passing to bootargs (like Linux's netconsole option)
1292 - Multicast TFTP Mode:
1295 Defines whether you want to support multicast TFTP as per
1296 rfc-2090; for example to work with atftp. Lets lots of targets
1297 tftp down the same boot image concurrently. Note: the Ethernet
1298 driver in use must provide a function: mcast() to join/leave a
1301 CONFIG_BOOTP_RANDOM_DELAY
1302 - BOOTP Recovery Mode:
1303 CONFIG_BOOTP_RANDOM_DELAY
1305 If you have many targets in a network that try to
1306 boot using BOOTP, you may want to avoid that all
1307 systems send out BOOTP requests at precisely the same
1308 moment (which would happen for instance at recovery
1309 from a power failure, when all systems will try to
1310 boot, thus flooding the BOOTP server. Defining
1311 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
1312 inserted before sending out BOOTP requests. The
1313 following delays are inserted then:
1315 1st BOOTP request: delay 0 ... 1 sec
1316 2nd BOOTP request: delay 0 ... 2 sec
1317 3rd BOOTP request: delay 0 ... 4 sec
1319 BOOTP requests: delay 0 ... 8 sec
1321 - DHCP Advanced Options:
1322 You can fine tune the DHCP functionality by defining
1323 CONFIG_BOOTP_* symbols:
1325 CONFIG_BOOTP_SUBNETMASK
1326 CONFIG_BOOTP_GATEWAY
1327 CONFIG_BOOTP_HOSTNAME
1328 CONFIG_BOOTP_NISDOMAIN
1329 CONFIG_BOOTP_BOOTPATH
1330 CONFIG_BOOTP_BOOTFILESIZE
1333 CONFIG_BOOTP_SEND_HOSTNAME
1334 CONFIG_BOOTP_NTPSERVER
1335 CONFIG_BOOTP_TIMEOFFSET
1336 CONFIG_BOOTP_VENDOREX
1338 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip
1339 environment variable, not the BOOTP server.
1341 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS
1342 serverip from a DHCP server, it is possible that more
1343 than one DNS serverip is offered to the client.
1344 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS
1345 serverip will be stored in the additional environment
1346 variable "dnsip2". The first DNS serverip is always
1347 stored in the variable "dnsip", when CONFIG_BOOTP_DNS
1350 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable
1351 to do a dynamic update of a DNS server. To do this, they
1352 need the hostname of the DHCP requester.
1353 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content
1354 of the "hostname" environment variable is passed as
1355 option 12 to the DHCP server.
1357 CONFIG_BOOTP_DHCP_REQUEST_DELAY
1359 A 32bit value in microseconds for a delay between
1360 receiving a "DHCP Offer" and sending the "DHCP Request".
1361 This fixes a problem with certain DHCP servers that don't
1362 respond 100% of the time to a "DHCP request". E.g. On an
1363 AT91RM9200 processor running at 180MHz, this delay needed
1364 to be *at least* 15,000 usec before a Windows Server 2003
1365 DHCP server would reply 100% of the time. I recommend at
1366 least 50,000 usec to be safe. The alternative is to hope
1367 that one of the retries will be successful but note that
1368 the DHCP timeout and retry process takes a longer than
1372 CONFIG_CDP_DEVICE_ID
1374 The device id used in CDP trigger frames.
1376 CONFIG_CDP_DEVICE_ID_PREFIX
1378 A two character string which is prefixed to the MAC address
1383 A printf format string which contains the ascii name of
1384 the port. Normally is set to "eth%d" which sets
1385 eth0 for the first Ethernet, eth1 for the second etc.
1387 CONFIG_CDP_CAPABILITIES
1389 A 32bit integer which indicates the device capabilities;
1390 0x00000010 for a normal host which does not forwards.
1394 An ascii string containing the version of the software.
1398 An ascii string containing the name of the platform.
1402 A 32bit integer sent on the trigger.
1404 CONFIG_CDP_POWER_CONSUMPTION
1406 A 16bit integer containing the power consumption of the
1407 device in .1 of milliwatts.
1409 CONFIG_CDP_APPLIANCE_VLAN_TYPE
1411 A byte containing the id of the VLAN.
1413 - Status LED: CONFIG_STATUS_LED
1415 Several configurations allow to display the current
1416 status using a LED. For instance, the LED will blink
1417 fast while running U-Boot code, stop blinking as
1418 soon as a reply to a BOOTP request was received, and
1419 start blinking slow once the Linux kernel is running
1420 (supported by a status LED driver in the Linux
1421 kernel). Defining CONFIG_STATUS_LED enables this
1424 - CAN Support: CONFIG_CAN_DRIVER
1426 Defining CONFIG_CAN_DRIVER enables CAN driver support
1427 on those systems that support this (optional)
1428 feature, like the TQM8xxL modules.
1430 - I2C Support: CONFIG_HARD_I2C | CONFIG_SOFT_I2C
1432 These enable I2C serial bus commands. Defining either of
1433 (but not both of) CONFIG_HARD_I2C or CONFIG_SOFT_I2C will
1434 include the appropriate I2C driver for the selected CPU.
1436 This will allow you to use i2c commands at the u-boot
1437 command line (as long as you set CONFIG_CMD_I2C in
1438 CONFIG_COMMANDS) and communicate with i2c based realtime
1439 clock chips. See common/cmd_i2c.c for a description of the
1440 command line interface.
1442 CONFIG_HARD_I2C selects a hardware I2C controller.
1444 CONFIG_SOFT_I2C configures u-boot to use a software (aka
1445 bit-banging) driver instead of CPM or similar hardware
1448 There are several other quantities that must also be
1449 defined when you define CONFIG_HARD_I2C or CONFIG_SOFT_I2C.
1451 In both cases you will need to define CONFIG_SYS_I2C_SPEED
1452 to be the frequency (in Hz) at which you wish your i2c bus
1453 to run and CONFIG_SYS_I2C_SLAVE to be the address of this node (ie
1454 the CPU's i2c node address).
1456 Now, the u-boot i2c code for the mpc8xx
1457 (arch/powerpc/cpu/mpc8xx/i2c.c) sets the CPU up as a master node
1458 and so its address should therefore be cleared to 0 (See,
1459 eg, MPC823e User's Manual p.16-473). So, set
1460 CONFIG_SYS_I2C_SLAVE to 0.
1462 CONFIG_SYS_I2C_INIT_MPC5XXX
1464 When a board is reset during an i2c bus transfer
1465 chips might think that the current transfer is still
1466 in progress. Reset the slave devices by sending start
1467 commands until the slave device responds.
1469 That's all that's required for CONFIG_HARD_I2C.
1471 If you use the software i2c interface (CONFIG_SOFT_I2C)
1472 then the following macros need to be defined (examples are
1473 from include/configs/lwmon.h):
1477 (Optional). Any commands necessary to enable the I2C
1478 controller or configure ports.
1480 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
1484 (Only for MPC8260 CPU). The I/O port to use (the code
1485 assumes both bits are on the same port). Valid values
1486 are 0..3 for ports A..D.
1490 The code necessary to make the I2C data line active
1491 (driven). If the data line is open collector, this
1494 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
1498 The code necessary to make the I2C data line tri-stated
1499 (inactive). If the data line is open collector, this
1502 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
1506 Code that returns TRUE if the I2C data line is high,
1509 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
1513 If <bit> is TRUE, sets the I2C data line high. If it
1514 is FALSE, it clears it (low).
1516 eg: #define I2C_SDA(bit) \
1517 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
1518 else immr->im_cpm.cp_pbdat &= ~PB_SDA
1522 If <bit> is TRUE, sets the I2C clock line high. If it
1523 is FALSE, it clears it (low).
1525 eg: #define I2C_SCL(bit) \
1526 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
1527 else immr->im_cpm.cp_pbdat &= ~PB_SCL
1531 This delay is invoked four times per clock cycle so this
1532 controls the rate of data transfer. The data rate thus
1533 is 1 / (I2C_DELAY * 4). Often defined to be something
1536 #define I2C_DELAY udelay(2)
1538 CONFIG_SOFT_I2C_GPIO_SCL / CONFIG_SOFT_I2C_GPIO_SDA
1540 If your arch supports the generic GPIO framework (asm/gpio.h),
1541 then you may alternatively define the two GPIOs that are to be
1542 used as SCL / SDA. Any of the previous I2C_xxx macros will
1543 have GPIO-based defaults assigned to them as appropriate.
1545 You should define these to the GPIO value as given directly to
1546 the generic GPIO functions.
1548 CONFIG_SYS_I2C_INIT_BOARD
1550 When a board is reset during an i2c bus transfer
1551 chips might think that the current transfer is still
1552 in progress. On some boards it is possible to access
1553 the i2c SCLK line directly, either by using the
1554 processor pin as a GPIO or by having a second pin
1555 connected to the bus. If this option is defined a
1556 custom i2c_init_board() routine in boards/xxx/board.c
1557 is run early in the boot sequence.
1559 CONFIG_SYS_I2C_BOARD_LATE_INIT
1561 An alternative to CONFIG_SYS_I2C_INIT_BOARD. If this option is
1562 defined a custom i2c_board_late_init() routine in
1563 boards/xxx/board.c is run AFTER the operations in i2c_init()
1564 is completed. This callpoint can be used to unreset i2c bus
1565 using CPU i2c controller register accesses for CPUs whose i2c
1566 controller provide such a method. It is called at the end of
1567 i2c_init() to allow i2c_init operations to setup the i2c bus
1568 controller on the CPU (e.g. setting bus speed & slave address).
1570 CONFIG_I2CFAST (PPC405GP|PPC405EP only)
1572 This option enables configuration of bi_iic_fast[] flags
1573 in u-boot bd_info structure based on u-boot environment
1574 variable "i2cfast". (see also i2cfast)
1576 CONFIG_I2C_MULTI_BUS
1578 This option allows the use of multiple I2C buses, each of which
1579 must have a controller. At any point in time, only one bus is
1580 active. To switch to a different bus, use the 'i2c dev' command.
1581 Note that bus numbering is zero-based.
1583 CONFIG_SYS_I2C_NOPROBES
1585 This option specifies a list of I2C devices that will be skipped
1586 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS
1587 is set, specify a list of bus-device pairs. Otherwise, specify
1588 a 1D array of device addresses
1591 #undef CONFIG_I2C_MULTI_BUS
1592 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68}
1594 will skip addresses 0x50 and 0x68 on a board with one I2C bus
1596 #define CONFIG_I2C_MULTI_BUS
1597 #define CONFIG_SYS_I2C_MULTI_NOPROBES {{0,0x50},{0,0x68},{1,0x54}}
1599 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1
1601 CONFIG_SYS_SPD_BUS_NUM
1603 If defined, then this indicates the I2C bus number for DDR SPD.
1604 If not defined, then U-Boot assumes that SPD is on I2C bus 0.
1606 CONFIG_SYS_RTC_BUS_NUM
1608 If defined, then this indicates the I2C bus number for the RTC.
1609 If not defined, then U-Boot assumes that RTC is on I2C bus 0.
1611 CONFIG_SYS_DTT_BUS_NUM
1613 If defined, then this indicates the I2C bus number for the DTT.
1614 If not defined, then U-Boot assumes that DTT is on I2C bus 0.
1616 CONFIG_SYS_I2C_DTT_ADDR:
1618 If defined, specifies the I2C address of the DTT device.
1619 If not defined, then U-Boot uses predefined value for
1620 specified DTT device.
1624 Define this option if you want to use Freescale's I2C driver in
1625 drivers/i2c/fsl_i2c.c.
1629 Define this option if you have I2C devices reached over 1 .. n
1630 I2C Muxes like the pca9544a. This option addes a new I2C
1631 Command "i2c bus [muxtype:muxaddr:muxchannel]" which adds a
1632 new I2C Bus to the existing I2C Busses. If you select the
1633 new Bus with "i2c dev", u-bbot sends first the commandos for
1634 the muxes to activate this new "bus".
1636 CONFIG_I2C_MULTI_BUS must be also defined, to use this
1640 Adding a new I2C Bus reached over 2 pca9544a muxes
1641 The First mux with address 70 and channel 6
1642 The Second mux with address 71 and channel 4
1644 => i2c bus pca9544a:70:6:pca9544a:71:4
1646 Use the "i2c bus" command without parameter, to get a list
1647 of I2C Busses with muxes:
1650 Busses reached over muxes:
1652 reached over Mux(es):
1655 reached over Mux(es):
1660 If you now switch to the new I2C Bus 3 with "i2c dev 3"
1661 u-boot sends First the Commando to the mux@70 to enable
1662 channel 6, and then the Commando to the mux@71 to enable
1665 After that, you can use the "normal" i2c commands as
1666 usual, to communicate with your I2C devices behind
1669 This option is actually implemented for the bitbanging
1670 algorithm in common/soft_i2c.c and for the Hardware I2C
1671 Bus on the MPC8260. But it should be not so difficult
1672 to add this option to other architectures.
1674 CONFIG_SOFT_I2C_READ_REPEATED_START
1676 defining this will force the i2c_read() function in
1677 the soft_i2c driver to perform an I2C repeated start
1678 between writing the address pointer and reading the
1679 data. If this define is omitted the default behaviour
1680 of doing a stop-start sequence will be used. Most I2C
1681 devices can use either method, but some require one or
1684 - SPI Support: CONFIG_SPI
1686 Enables SPI driver (so far only tested with
1687 SPI EEPROM, also an instance works with Crystal A/D and
1688 D/As on the SACSng board)
1692 Enables the driver for SPI controller on SuperH. Currently
1693 only SH7757 is supported.
1697 Enables extended (16-bit) SPI EEPROM addressing.
1698 (symmetrical to CONFIG_I2C_X)
1702 Enables a software (bit-bang) SPI driver rather than
1703 using hardware support. This is a general purpose
1704 driver that only requires three general I/O port pins
1705 (two outputs, one input) to function. If this is
1706 defined, the board configuration must define several
1707 SPI configuration items (port pins to use, etc). For
1708 an example, see include/configs/sacsng.h.
1712 Enables a hardware SPI driver for general-purpose reads
1713 and writes. As with CONFIG_SOFT_SPI, the board configuration
1714 must define a list of chip-select function pointers.
1715 Currently supported on some MPC8xxx processors. For an
1716 example, see include/configs/mpc8349emds.h.
1720 Enables the driver for the SPI controllers on i.MX and MXC
1721 SoCs. Currently only i.MX31 is supported.
1723 - FPGA Support: CONFIG_FPGA
1725 Enables FPGA subsystem.
1727 CONFIG_FPGA_<vendor>
1729 Enables support for specific chip vendors.
1732 CONFIG_FPGA_<family>
1734 Enables support for FPGA family.
1735 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX)
1739 Specify the number of FPGA devices to support.
1741 CONFIG_SYS_FPGA_PROG_FEEDBACK
1743 Enable printing of hash marks during FPGA configuration.
1745 CONFIG_SYS_FPGA_CHECK_BUSY
1747 Enable checks on FPGA configuration interface busy
1748 status by the configuration function. This option
1749 will require a board or device specific function to
1754 If defined, a function that provides delays in the FPGA
1755 configuration driver.
1757 CONFIG_SYS_FPGA_CHECK_CTRLC
1758 Allow Control-C to interrupt FPGA configuration
1760 CONFIG_SYS_FPGA_CHECK_ERROR
1762 Check for configuration errors during FPGA bitfile
1763 loading. For example, abort during Virtex II
1764 configuration if the INIT_B line goes low (which
1765 indicated a CRC error).
1767 CONFIG_SYS_FPGA_WAIT_INIT
1769 Maximum time to wait for the INIT_B line to deassert
1770 after PROB_B has been deasserted during a Virtex II
1771 FPGA configuration sequence. The default time is 500
1774 CONFIG_SYS_FPGA_WAIT_BUSY
1776 Maximum time to wait for BUSY to deassert during
1777 Virtex II FPGA configuration. The default is 5 ms.
1779 CONFIG_SYS_FPGA_WAIT_CONFIG
1781 Time to wait after FPGA configuration. The default is
1784 - Configuration Management:
1787 If defined, this string will be added to the U-Boot
1788 version information (U_BOOT_VERSION)
1790 - Vendor Parameter Protection:
1792 U-Boot considers the values of the environment
1793 variables "serial#" (Board Serial Number) and
1794 "ethaddr" (Ethernet Address) to be parameters that
1795 are set once by the board vendor / manufacturer, and
1796 protects these variables from casual modification by
1797 the user. Once set, these variables are read-only,
1798 and write or delete attempts are rejected. You can
1799 change this behaviour:
1801 If CONFIG_ENV_OVERWRITE is #defined in your config
1802 file, the write protection for vendor parameters is
1803 completely disabled. Anybody can change or delete
1806 Alternatively, if you #define _both_ CONFIG_ETHADDR
1807 _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
1808 Ethernet address is installed in the environment,
1809 which can be changed exactly ONCE by the user. [The
1810 serial# is unaffected by this, i. e. it remains
1816 Define this variable to enable the reservation of
1817 "protected RAM", i. e. RAM which is not overwritten
1818 by U-Boot. Define CONFIG_PRAM to hold the number of
1819 kB you want to reserve for pRAM. You can overwrite
1820 this default value by defining an environment
1821 variable "pram" to the number of kB you want to
1822 reserve. Note that the board info structure will
1823 still show the full amount of RAM. If pRAM is
1824 reserved, a new environment variable "mem" will
1825 automatically be defined to hold the amount of
1826 remaining RAM in a form that can be passed as boot
1827 argument to Linux, for instance like that:
1829 setenv bootargs ... mem=\${mem}
1832 This way you can tell Linux not to use this memory,
1833 either, which results in a memory region that will
1834 not be affected by reboots.
1836 *WARNING* If your board configuration uses automatic
1837 detection of the RAM size, you must make sure that
1838 this memory test is non-destructive. So far, the
1839 following board configurations are known to be
1842 ETX094, IVMS8, IVML24, SPD8xx, TQM8xxL,
1843 HERMES, IP860, RPXlite, LWMON, LANTEC,
1849 Define this variable to stop the system in case of a
1850 fatal error, so that you have to reset it manually.
1851 This is probably NOT a good idea for an embedded
1852 system where you want the system to reboot
1853 automatically as fast as possible, but it may be
1854 useful during development since you can try to debug
1855 the conditions that lead to the situation.
1857 CONFIG_NET_RETRY_COUNT
1859 This variable defines the number of retries for
1860 network operations like ARP, RARP, TFTP, or BOOTP
1861 before giving up the operation. If not defined, a
1862 default value of 5 is used.
1866 Timeout waiting for an ARP reply in milliseconds.
1868 - Command Interpreter:
1869 CONFIG_AUTO_COMPLETE
1871 Enable auto completion of commands using TAB.
1873 Note that this feature has NOT been implemented yet
1874 for the "hush" shell.
1877 CONFIG_SYS_HUSH_PARSER
1879 Define this variable to enable the "hush" shell (from
1880 Busybox) as command line interpreter, thus enabling
1881 powerful command line syntax like
1882 if...then...else...fi conditionals or `&&' and '||'
1883 constructs ("shell scripts").
1885 If undefined, you get the old, much simpler behaviour
1886 with a somewhat smaller memory footprint.
1889 CONFIG_SYS_PROMPT_HUSH_PS2
1891 This defines the secondary prompt string, which is
1892 printed when the command interpreter needs more input
1893 to complete a command. Usually "> ".
1897 In the current implementation, the local variables
1898 space and global environment variables space are
1899 separated. Local variables are those you define by
1900 simply typing `name=value'. To access a local
1901 variable later on, you have write `$name' or
1902 `${name}'; to execute the contents of a variable
1903 directly type `$name' at the command prompt.
1905 Global environment variables are those you use
1906 setenv/printenv to work with. To run a command stored
1907 in such a variable, you need to use the run command,
1908 and you must not use the '$' sign to access them.
1910 To store commands and special characters in a
1911 variable, please use double quotation marks
1912 surrounding the whole text of the variable, instead
1913 of the backslashes before semicolons and special
1916 - Commandline Editing and History:
1917 CONFIG_CMDLINE_EDITING
1919 Enable editing and History functions for interactive
1920 commandline input operations
1922 - Default Environment:
1923 CONFIG_EXTRA_ENV_SETTINGS
1925 Define this to contain any number of null terminated
1926 strings (variable = value pairs) that will be part of
1927 the default environment compiled into the boot image.
1929 For example, place something like this in your
1930 board's config file:
1932 #define CONFIG_EXTRA_ENV_SETTINGS \
1936 Warning: This method is based on knowledge about the
1937 internal format how the environment is stored by the
1938 U-Boot code. This is NOT an official, exported
1939 interface! Although it is unlikely that this format
1940 will change soon, there is no guarantee either.
1941 You better know what you are doing here.
1943 Note: overly (ab)use of the default environment is
1944 discouraged. Make sure to check other ways to preset
1945 the environment like the "source" command or the
1948 - DataFlash Support:
1949 CONFIG_HAS_DATAFLASH
1951 Defining this option enables DataFlash features and
1952 allows to read/write in Dataflash via the standard
1955 - SystemACE Support:
1958 Adding this option adds support for Xilinx SystemACE
1959 chips attached via some sort of local bus. The address
1960 of the chip must also be defined in the
1961 CONFIG_SYS_SYSTEMACE_BASE macro. For example:
1963 #define CONFIG_SYSTEMACE
1964 #define CONFIG_SYS_SYSTEMACE_BASE 0xf0000000
1966 When SystemACE support is added, the "ace" device type
1967 becomes available to the fat commands, i.e. fatls.
1969 - TFTP Fixed UDP Port:
1972 If this is defined, the environment variable tftpsrcp
1973 is used to supply the TFTP UDP source port value.
1974 If tftpsrcp isn't defined, the normal pseudo-random port
1975 number generator is used.
1977 Also, the environment variable tftpdstp is used to supply
1978 the TFTP UDP destination port value. If tftpdstp isn't
1979 defined, the normal port 69 is used.
1981 The purpose for tftpsrcp is to allow a TFTP server to
1982 blindly start the TFTP transfer using the pre-configured
1983 target IP address and UDP port. This has the effect of
1984 "punching through" the (Windows XP) firewall, allowing
1985 the remainder of the TFTP transfer to proceed normally.
1986 A better solution is to properly configure the firewall,
1987 but sometimes that is not allowed.
1989 - Show boot progress:
1990 CONFIG_SHOW_BOOT_PROGRESS
1992 Defining this option allows to add some board-
1993 specific code (calling a user-provided function
1994 "show_boot_progress(int)") that enables you to show
1995 the system's boot progress on some display (for
1996 example, some LED's) on your board. At the moment,
1997 the following checkpoints are implemented:
1999 Legacy uImage format:
2002 1 common/cmd_bootm.c before attempting to boot an image
2003 -1 common/cmd_bootm.c Image header has bad magic number
2004 2 common/cmd_bootm.c Image header has correct magic number
2005 -2 common/cmd_bootm.c Image header has bad checksum
2006 3 common/cmd_bootm.c Image header has correct checksum
2007 -3 common/cmd_bootm.c Image data has bad checksum
2008 4 common/cmd_bootm.c Image data has correct checksum
2009 -4 common/cmd_bootm.c Image is for unsupported architecture
2010 5 common/cmd_bootm.c Architecture check OK
2011 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi)
2012 6 common/cmd_bootm.c Image Type check OK
2013 -6 common/cmd_bootm.c gunzip uncompression error
2014 -7 common/cmd_bootm.c Unimplemented compression type
2015 7 common/cmd_bootm.c Uncompression OK
2016 8 common/cmd_bootm.c No uncompress/copy overwrite error
2017 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX)
2019 9 common/image.c Start initial ramdisk verification
2020 -10 common/image.c Ramdisk header has bad magic number
2021 -11 common/image.c Ramdisk header has bad checksum
2022 10 common/image.c Ramdisk header is OK
2023 -12 common/image.c Ramdisk data has bad checksum
2024 11 common/image.c Ramdisk data has correct checksum
2025 12 common/image.c Ramdisk verification complete, start loading
2026 -13 common/image.c Wrong Image Type (not PPC Linux ramdisk)
2027 13 common/image.c Start multifile image verification
2028 14 common/image.c No initial ramdisk, no multifile, continue.
2030 15 arch/<arch>/lib/bootm.c All preparation done, transferring control to OS
2032 -30 arch/powerpc/lib/board.c Fatal error, hang the system
2033 -31 post/post.c POST test failed, detected by post_output_backlog()
2034 -32 post/post.c POST test failed, detected by post_run_single()
2036 34 common/cmd_doc.c before loading a Image from a DOC device
2037 -35 common/cmd_doc.c Bad usage of "doc" command
2038 35 common/cmd_doc.c correct usage of "doc" command
2039 -36 common/cmd_doc.c No boot device
2040 36 common/cmd_doc.c correct boot device
2041 -37 common/cmd_doc.c Unknown Chip ID on boot device
2042 37 common/cmd_doc.c correct chip ID found, device available
2043 -38 common/cmd_doc.c Read Error on boot device
2044 38 common/cmd_doc.c reading Image header from DOC device OK
2045 -39 common/cmd_doc.c Image header has bad magic number
2046 39 common/cmd_doc.c Image header has correct magic number
2047 -40 common/cmd_doc.c Error reading Image from DOC device
2048 40 common/cmd_doc.c Image header has correct magic number
2049 41 common/cmd_ide.c before loading a Image from a IDE device
2050 -42 common/cmd_ide.c Bad usage of "ide" command
2051 42 common/cmd_ide.c correct usage of "ide" command
2052 -43 common/cmd_ide.c No boot device
2053 43 common/cmd_ide.c boot device found
2054 -44 common/cmd_ide.c Device not available
2055 44 common/cmd_ide.c Device available
2056 -45 common/cmd_ide.c wrong partition selected
2057 45 common/cmd_ide.c partition selected
2058 -46 common/cmd_ide.c Unknown partition table
2059 46 common/cmd_ide.c valid partition table found
2060 -47 common/cmd_ide.c Invalid partition type
2061 47 common/cmd_ide.c correct partition type
2062 -48 common/cmd_ide.c Error reading Image Header on boot device
2063 48 common/cmd_ide.c reading Image Header from IDE device OK
2064 -49 common/cmd_ide.c Image header has bad magic number
2065 49 common/cmd_ide.c Image header has correct magic number
2066 -50 common/cmd_ide.c Image header has bad checksum
2067 50 common/cmd_ide.c Image header has correct checksum
2068 -51 common/cmd_ide.c Error reading Image from IDE device
2069 51 common/cmd_ide.c reading Image from IDE device OK
2070 52 common/cmd_nand.c before loading a Image from a NAND device
2071 -53 common/cmd_nand.c Bad usage of "nand" command
2072 53 common/cmd_nand.c correct usage of "nand" command
2073 -54 common/cmd_nand.c No boot device
2074 54 common/cmd_nand.c boot device found
2075 -55 common/cmd_nand.c Unknown Chip ID on boot device
2076 55 common/cmd_nand.c correct chip ID found, device available
2077 -56 common/cmd_nand.c Error reading Image Header on boot device
2078 56 common/cmd_nand.c reading Image Header from NAND device OK
2079 -57 common/cmd_nand.c Image header has bad magic number
2080 57 common/cmd_nand.c Image header has correct magic number
2081 -58 common/cmd_nand.c Error reading Image from NAND device
2082 58 common/cmd_nand.c reading Image from NAND device OK
2084 -60 common/env_common.c Environment has a bad CRC, using default
2086 64 net/eth.c starting with Ethernet configuration.
2087 -64 net/eth.c no Ethernet found.
2088 65 net/eth.c Ethernet found.
2090 -80 common/cmd_net.c usage wrong
2091 80 common/cmd_net.c before calling NetLoop()
2092 -81 common/cmd_net.c some error in NetLoop() occurred
2093 81 common/cmd_net.c NetLoop() back without error
2094 -82 common/cmd_net.c size == 0 (File with size 0 loaded)
2095 82 common/cmd_net.c trying automatic boot
2096 83 common/cmd_net.c running "source" command
2097 -83 common/cmd_net.c some error in automatic boot or "source" command
2098 84 common/cmd_net.c end without errors
2103 100 common/cmd_bootm.c Kernel FIT Image has correct format
2104 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format
2105 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration
2106 -101 common/cmd_bootm.c Can't get configuration for kernel subimage
2107 102 common/cmd_bootm.c Kernel unit name specified
2108 -103 common/cmd_bootm.c Can't get kernel subimage node offset
2109 103 common/cmd_bootm.c Found configuration node
2110 104 common/cmd_bootm.c Got kernel subimage node offset
2111 -104 common/cmd_bootm.c Kernel subimage hash verification failed
2112 105 common/cmd_bootm.c Kernel subimage hash verification OK
2113 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture
2114 106 common/cmd_bootm.c Architecture check OK
2115 -106 common/cmd_bootm.c Kernel subimage has wrong type
2116 107 common/cmd_bootm.c Kernel subimage type OK
2117 -107 common/cmd_bootm.c Can't get kernel subimage data/size
2118 108 common/cmd_bootm.c Got kernel subimage data/size
2119 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT)
2120 -109 common/cmd_bootm.c Can't get kernel subimage type
2121 -110 common/cmd_bootm.c Can't get kernel subimage comp
2122 -111 common/cmd_bootm.c Can't get kernel subimage os
2123 -112 common/cmd_bootm.c Can't get kernel subimage load address
2124 -113 common/cmd_bootm.c Image uncompress/copy overwrite error
2126 120 common/image.c Start initial ramdisk verification
2127 -120 common/image.c Ramdisk FIT image has incorrect format
2128 121 common/image.c Ramdisk FIT image has correct format
2129 122 common/image.c No ramdisk subimage unit name, using configuration
2130 -122 common/image.c Can't get configuration for ramdisk subimage
2131 123 common/image.c Ramdisk unit name specified
2132 -124 common/image.c Can't get ramdisk subimage node offset
2133 125 common/image.c Got ramdisk subimage node offset
2134 -125 common/image.c Ramdisk subimage hash verification failed
2135 126 common/image.c Ramdisk subimage hash verification OK
2136 -126 common/image.c Ramdisk subimage for unsupported architecture
2137 127 common/image.c Architecture check OK
2138 -127 common/image.c Can't get ramdisk subimage data/size
2139 128 common/image.c Got ramdisk subimage data/size
2140 129 common/image.c Can't get ramdisk load address
2141 -129 common/image.c Got ramdisk load address
2143 -130 common/cmd_doc.c Incorrect FIT image format
2144 131 common/cmd_doc.c FIT image format OK
2146 -140 common/cmd_ide.c Incorrect FIT image format
2147 141 common/cmd_ide.c FIT image format OK
2149 -150 common/cmd_nand.c Incorrect FIT image format
2150 151 common/cmd_nand.c FIT image format OK
2152 - Automatic software updates via TFTP server
2154 CONFIG_UPDATE_TFTP_CNT_MAX
2155 CONFIG_UPDATE_TFTP_MSEC_MAX
2157 These options enable and control the auto-update feature;
2158 for a more detailed description refer to doc/README.update.
2160 - MTD Support (mtdparts command, UBI support)
2163 Adds the MTD device infrastructure from the Linux kernel.
2164 Needed for mtdparts command support.
2166 CONFIG_MTD_PARTITIONS
2168 Adds the MTD partitioning infrastructure from the Linux
2169 kernel. Needed for UBI support.
2175 [so far only for SMDK2400 and TRAB boards]
2177 - Modem support enable:
2178 CONFIG_MODEM_SUPPORT
2180 - RTS/CTS Flow control enable:
2183 - Modem debug support:
2184 CONFIG_MODEM_SUPPORT_DEBUG
2186 Enables debugging stuff (char screen[1024], dbg())
2187 for modem support. Useful only with BDI2000.
2189 - Interrupt support (PPC):
2191 There are common interrupt_init() and timer_interrupt()
2192 for all PPC archs. interrupt_init() calls interrupt_init_cpu()
2193 for CPU specific initialization. interrupt_init_cpu()
2194 should set decrementer_count to appropriate value. If
2195 CPU resets decrementer automatically after interrupt
2196 (ppc4xx) it should set decrementer_count to zero.
2197 timer_interrupt() calls timer_interrupt_cpu() for CPU
2198 specific handling. If board has watchdog / status_led
2199 / other_activity_monitor it works automatically from
2200 general timer_interrupt().
2204 In the target system modem support is enabled when a
2205 specific key (key combination) is pressed during
2206 power-on. Otherwise U-Boot will boot normally
2207 (autoboot). The key_pressed() function is called from
2208 board_init(). Currently key_pressed() is a dummy
2209 function, returning 1 and thus enabling modem
2212 If there are no modem init strings in the
2213 environment, U-Boot proceed to autoboot; the
2214 previous output (banner, info printfs) will be
2217 See also: doc/README.Modem
2220 Configuration Settings:
2221 -----------------------
2223 - CONFIG_SYS_LONGHELP: Defined when you want long help messages included;
2224 undefine this when you're short of memory.
2226 - CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default
2227 width of the commands listed in the 'help' command output.
2229 - CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to
2230 prompt for user input.
2232 - CONFIG_SYS_CBSIZE: Buffer size for input from the Console
2234 - CONFIG_SYS_PBSIZE: Buffer size for Console output
2236 - CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands
2238 - CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to
2239 the application (usually a Linux kernel) when it is
2242 - CONFIG_SYS_BAUDRATE_TABLE:
2243 List of legal baudrate settings for this board.
2245 - CONFIG_SYS_CONSOLE_INFO_QUIET
2246 Suppress display of console information at boot.
2248 - CONFIG_SYS_CONSOLE_IS_IN_ENV
2249 If the board specific function
2250 extern int overwrite_console (void);
2251 returns 1, the stdin, stderr and stdout are switched to the
2252 serial port, else the settings in the environment are used.
2254 - CONFIG_SYS_CONSOLE_OVERWRITE_ROUTINE
2255 Enable the call to overwrite_console().
2257 - CONFIG_SYS_CONSOLE_ENV_OVERWRITE
2258 Enable overwrite of previous console environment settings.
2260 - CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END:
2261 Begin and End addresses of the area used by the
2264 - CONFIG_SYS_ALT_MEMTEST:
2265 Enable an alternate, more extensive memory test.
2267 - CONFIG_SYS_MEMTEST_SCRATCH:
2268 Scratch address used by the alternate memory test
2269 You only need to set this if address zero isn't writeable
2271 - CONFIG_SYS_MEM_TOP_HIDE (PPC only):
2272 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header,
2273 this specified memory area will get subtracted from the top
2274 (end) of RAM and won't get "touched" at all by U-Boot. By
2275 fixing up gd->ram_size the Linux kernel should gets passed
2276 the now "corrected" memory size and won't touch it either.
2277 This should work for arch/ppc and arch/powerpc. Only Linux
2278 board ports in arch/powerpc with bootwrapper support that
2279 recalculate the memory size from the SDRAM controller setup
2280 will have to get fixed in Linux additionally.
2282 This option can be used as a workaround for the 440EPx/GRx
2283 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't
2286 WARNING: Please make sure that this value is a multiple of
2287 the Linux page size (normally 4k). If this is not the case,
2288 then the end address of the Linux memory will be located at a
2289 non page size aligned address and this could cause major
2292 - CONFIG_SYS_TFTP_LOADADDR:
2293 Default load address for network file downloads
2295 - CONFIG_SYS_LOADS_BAUD_CHANGE:
2296 Enable temporary baudrate change while serial download
2298 - CONFIG_SYS_SDRAM_BASE:
2299 Physical start address of SDRAM. _Must_ be 0 here.
2301 - CONFIG_SYS_MBIO_BASE:
2302 Physical start address of Motherboard I/O (if using a
2305 - CONFIG_SYS_FLASH_BASE:
2306 Physical start address of Flash memory.
2308 - CONFIG_SYS_MONITOR_BASE:
2309 Physical start address of boot monitor code (set by
2310 make config files to be same as the text base address
2311 (CONFIG_SYS_TEXT_BASE) used when linking) - same as
2312 CONFIG_SYS_FLASH_BASE when booting from flash.
2314 - CONFIG_SYS_MONITOR_LEN:
2315 Size of memory reserved for monitor code, used to
2316 determine _at_compile_time_ (!) if the environment is
2317 embedded within the U-Boot image, or in a separate
2320 - CONFIG_SYS_MALLOC_LEN:
2321 Size of DRAM reserved for malloc() use.
2323 - CONFIG_SYS_BOOTM_LEN:
2324 Normally compressed uImages are limited to an
2325 uncompressed size of 8 MBytes. If this is not enough,
2326 you can define CONFIG_SYS_BOOTM_LEN in your board config file
2327 to adjust this setting to your needs.
2329 - CONFIG_SYS_BOOTMAPSZ:
2330 Maximum size of memory mapped by the startup code of
2331 the Linux kernel; all data that must be processed by
2332 the Linux kernel (bd_info, boot arguments, FDT blob if
2333 used) must be put below this limit, unless "bootm_low"
2334 enviroment variable is defined and non-zero. In such case
2335 all data for the Linux kernel must be between "bootm_low"
2336 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ.
2338 - CONFIG_SYS_BOOT_RAMDISK_HIGH:
2339 Enable initrd_high functionality. If defined then the
2340 initrd_high feature is enabled and the bootm ramdisk subcommand
2343 - CONFIG_SYS_BOOT_GET_CMDLINE:
2344 Enables allocating and saving kernel cmdline in space between
2345 "bootm_low" and "bootm_low" + BOOTMAPSZ.
2347 - CONFIG_SYS_BOOT_GET_KBD:
2348 Enables allocating and saving a kernel copy of the bd_info in
2349 space between "bootm_low" and "bootm_low" + BOOTMAPSZ.
2351 - CONFIG_SYS_MAX_FLASH_BANKS:
2352 Max number of Flash memory banks
2354 - CONFIG_SYS_MAX_FLASH_SECT:
2355 Max number of sectors on a Flash chip
2357 - CONFIG_SYS_FLASH_ERASE_TOUT:
2358 Timeout for Flash erase operations (in ms)
2360 - CONFIG_SYS_FLASH_WRITE_TOUT:
2361 Timeout for Flash write operations (in ms)
2363 - CONFIG_SYS_FLASH_LOCK_TOUT
2364 Timeout for Flash set sector lock bit operation (in ms)
2366 - CONFIG_SYS_FLASH_UNLOCK_TOUT
2367 Timeout for Flash clear lock bits operation (in ms)
2369 - CONFIG_SYS_FLASH_PROTECTION
2370 If defined, hardware flash sectors protection is used
2371 instead of U-Boot software protection.
2373 - CONFIG_SYS_DIRECT_FLASH_TFTP:
2375 Enable TFTP transfers directly to flash memory;
2376 without this option such a download has to be
2377 performed in two steps: (1) download to RAM, and (2)
2378 copy from RAM to flash.
2380 The two-step approach is usually more reliable, since
2381 you can check if the download worked before you erase
2382 the flash, but in some situations (when system RAM is
2383 too limited to allow for a temporary copy of the
2384 downloaded image) this option may be very useful.
2386 - CONFIG_SYS_FLASH_CFI:
2387 Define if the flash driver uses extra elements in the
2388 common flash structure for storing flash geometry.
2390 - CONFIG_FLASH_CFI_DRIVER
2391 This option also enables the building of the cfi_flash driver
2392 in the drivers directory
2394 - CONFIG_FLASH_CFI_MTD
2395 This option enables the building of the cfi_mtd driver
2396 in the drivers directory. The driver exports CFI flash
2399 - CONFIG_SYS_FLASH_USE_BUFFER_WRITE
2400 Use buffered writes to flash.
2402 - CONFIG_FLASH_SPANSION_S29WS_N
2403 s29ws-n MirrorBit flash has non-standard addresses for buffered
2406 - CONFIG_SYS_FLASH_QUIET_TEST
2407 If this option is defined, the common CFI flash doesn't
2408 print it's warning upon not recognized FLASH banks. This
2409 is useful, if some of the configured banks are only
2410 optionally available.
2412 - CONFIG_FLASH_SHOW_PROGRESS
2413 If defined (must be an integer), print out countdown
2414 digits and dots. Recommended value: 45 (9..1) for 80
2415 column displays, 15 (3..1) for 40 column displays.
2417 - CONFIG_SYS_RX_ETH_BUFFER:
2418 Defines the number of Ethernet receive buffers. On some
2419 Ethernet controllers it is recommended to set this value
2420 to 8 or even higher (EEPRO100 or 405 EMAC), since all
2421 buffers can be full shortly after enabling the interface
2422 on high Ethernet traffic.
2423 Defaults to 4 if not defined.
2425 - CONFIG_ENV_MAX_ENTRIES
2427 Maximum number of entries in the hash table that is used
2428 internally to store the environment settings. The default
2429 setting is supposed to be generous and should work in most
2430 cases. This setting can be used to tune behaviour; see
2431 lib/hashtable.c for details.
2433 The following definitions that deal with the placement and management
2434 of environment data (variable area); in general, we support the
2435 following configurations:
2437 - CONFIG_ENV_IS_IN_FLASH:
2439 Define this if the environment is in flash memory.
2441 a) The environment occupies one whole flash sector, which is
2442 "embedded" in the text segment with the U-Boot code. This
2443 happens usually with "bottom boot sector" or "top boot
2444 sector" type flash chips, which have several smaller
2445 sectors at the start or the end. For instance, such a
2446 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In
2447 such a case you would place the environment in one of the
2448 4 kB sectors - with U-Boot code before and after it. With
2449 "top boot sector" type flash chips, you would put the
2450 environment in one of the last sectors, leaving a gap
2451 between U-Boot and the environment.
2453 - CONFIG_ENV_OFFSET:
2455 Offset of environment data (variable area) to the
2456 beginning of flash memory; for instance, with bottom boot
2457 type flash chips the second sector can be used: the offset
2458 for this sector is given here.
2460 CONFIG_ENV_OFFSET is used relative to CONFIG_SYS_FLASH_BASE.
2464 This is just another way to specify the start address of
2465 the flash sector containing the environment (instead of
2468 - CONFIG_ENV_SECT_SIZE:
2470 Size of the sector containing the environment.
2473 b) Sometimes flash chips have few, equal sized, BIG sectors.
2474 In such a case you don't want to spend a whole sector for
2479 If you use this in combination with CONFIG_ENV_IS_IN_FLASH
2480 and CONFIG_ENV_SECT_SIZE, you can specify to use only a part
2481 of this flash sector for the environment. This saves
2482 memory for the RAM copy of the environment.
2484 It may also save flash memory if you decide to use this
2485 when your environment is "embedded" within U-Boot code,
2486 since then the remainder of the flash sector could be used
2487 for U-Boot code. It should be pointed out that this is
2488 STRONGLY DISCOURAGED from a robustness point of view:
2489 updating the environment in flash makes it always
2490 necessary to erase the WHOLE sector. If something goes
2491 wrong before the contents has been restored from a copy in
2492 RAM, your target system will be dead.
2494 - CONFIG_ENV_ADDR_REDUND
2495 CONFIG_ENV_SIZE_REDUND
2497 These settings describe a second storage area used to hold
2498 a redundant copy of the environment data, so that there is
2499 a valid backup copy in case there is a power failure during
2500 a "saveenv" operation.
2502 BE CAREFUL! Any changes to the flash layout, and some changes to the
2503 source code will make it necessary to adapt <board>/u-boot.lds*
2507 - CONFIG_ENV_IS_IN_NVRAM:
2509 Define this if you have some non-volatile memory device
2510 (NVRAM, battery buffered SRAM) which you want to use for the
2516 These two #defines are used to determine the memory area you
2517 want to use for environment. It is assumed that this memory
2518 can just be read and written to, without any special
2521 BE CAREFUL! The first access to the environment happens quite early
2522 in U-Boot initalization (when we try to get the setting of for the
2523 console baudrate). You *MUST* have mapped your NVRAM area then, or
2526 Please note that even with NVRAM we still use a copy of the
2527 environment in RAM: we could work on NVRAM directly, but we want to
2528 keep settings there always unmodified except somebody uses "saveenv"
2529 to save the current settings.
2532 - CONFIG_ENV_IS_IN_EEPROM:
2534 Use this if you have an EEPROM or similar serial access
2535 device and a driver for it.
2537 - CONFIG_ENV_OFFSET:
2540 These two #defines specify the offset and size of the
2541 environment area within the total memory of your EEPROM.
2543 - CONFIG_SYS_I2C_EEPROM_ADDR:
2544 If defined, specified the chip address of the EEPROM device.
2545 The default address is zero.
2547 - CONFIG_SYS_EEPROM_PAGE_WRITE_BITS:
2548 If defined, the number of bits used to address bytes in a
2549 single page in the EEPROM device. A 64 byte page, for example
2550 would require six bits.
2552 - CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS:
2553 If defined, the number of milliseconds to delay between
2554 page writes. The default is zero milliseconds.
2556 - CONFIG_SYS_I2C_EEPROM_ADDR_LEN:
2557 The length in bytes of the EEPROM memory array address. Note
2558 that this is NOT the chip address length!
2560 - CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW:
2561 EEPROM chips that implement "address overflow" are ones
2562 like Catalyst 24WC04/08/16 which has 9/10/11 bits of
2563 address and the extra bits end up in the "chip address" bit
2564 slots. This makes a 24WC08 (1Kbyte) chip look like four 256
2567 Note that we consider the length of the address field to
2568 still be one byte because the extra address bits are hidden
2569 in the chip address.
2571 - CONFIG_SYS_EEPROM_SIZE:
2572 The size in bytes of the EEPROM device.
2574 - CONFIG_ENV_EEPROM_IS_ON_I2C
2575 define this, if you have I2C and SPI activated, and your
2576 EEPROM, which holds the environment, is on the I2C bus.
2578 - CONFIG_I2C_ENV_EEPROM_BUS
2579 if you have an Environment on an EEPROM reached over
2580 I2C muxes, you can define here, how to reach this
2581 EEPROM. For example:
2583 #define CONFIG_I2C_ENV_EEPROM_BUS "pca9547:70:d\0"
2585 EEPROM which holds the environment, is reached over
2586 a pca9547 i2c mux with address 0x70, channel 3.
2588 - CONFIG_ENV_IS_IN_DATAFLASH:
2590 Define this if you have a DataFlash memory device which you
2591 want to use for the environment.
2593 - CONFIG_ENV_OFFSET:
2597 These three #defines specify the offset and size of the
2598 environment area within the total memory of your DataFlash placed
2599 at the specified address.
2601 - CONFIG_ENV_IS_IN_NAND:
2603 Define this if you have a NAND device which you want to use
2604 for the environment.
2606 - CONFIG_ENV_OFFSET:
2609 These two #defines specify the offset and size of the environment
2610 area within the first NAND device. CONFIG_ENV_OFFSET must be
2611 aligned to an erase block boundary.
2613 - CONFIG_ENV_OFFSET_REDUND (optional):
2615 This setting describes a second storage area of CONFIG_ENV_SIZE
2616 size used to hold a redundant copy of the environment data, so
2617 that there is a valid backup copy in case there is a power failure
2618 during a "saveenv" operation. CONFIG_ENV_OFFSET_RENDUND must be
2619 aligned to an erase block boundary.
2621 - CONFIG_ENV_RANGE (optional):
2623 Specifies the length of the region in which the environment
2624 can be written. This should be a multiple of the NAND device's
2625 block size. Specifying a range with more erase blocks than
2626 are needed to hold CONFIG_ENV_SIZE allows bad blocks within
2627 the range to be avoided.
2629 - CONFIG_ENV_OFFSET_OOB (optional):
2631 Enables support for dynamically retrieving the offset of the
2632 environment from block zero's out-of-band data. The
2633 "nand env.oob" command can be used to record this offset.
2634 Currently, CONFIG_ENV_OFFSET_REDUND is not supported when
2635 using CONFIG_ENV_OFFSET_OOB.
2637 - CONFIG_NAND_ENV_DST
2639 Defines address in RAM to which the nand_spl code should copy the
2640 environment. If redundant environment is used, it will be copied to
2641 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE.
2643 - CONFIG_SYS_SPI_INIT_OFFSET
2645 Defines offset to the initial SPI buffer area in DPRAM. The
2646 area is used at an early stage (ROM part) if the environment
2647 is configured to reside in the SPI EEPROM: We need a 520 byte
2648 scratch DPRAM area. It is used between the two initialization
2649 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems
2650 to be a good choice since it makes it far enough from the
2651 start of the data area as well as from the stack pointer.
2653 Please note that the environment is read-only until the monitor
2654 has been relocated to RAM and a RAM copy of the environment has been
2655 created; also, when using EEPROM you will have to use getenv_f()
2656 until then to read environment variables.
2658 The environment is protected by a CRC32 checksum. Before the monitor
2659 is relocated into RAM, as a result of a bad CRC you will be working
2660 with the compiled-in default environment - *silently*!!! [This is
2661 necessary, because the first environment variable we need is the
2662 "baudrate" setting for the console - if we have a bad CRC, we don't
2663 have any device yet where we could complain.]
2665 Note: once the monitor has been relocated, then it will complain if
2666 the default environment is used; a new CRC is computed as soon as you
2667 use the "saveenv" command to store a valid environment.
2669 - CONFIG_SYS_FAULT_ECHO_LINK_DOWN:
2670 Echo the inverted Ethernet link state to the fault LED.
2672 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR
2673 also needs to be defined.
2675 - CONFIG_SYS_FAULT_MII_ADDR:
2676 MII address of the PHY to check for the Ethernet link state.
2678 - CONFIG_NS16550_MIN_FUNCTIONS:
2679 Define this if you desire to only have use of the NS16550_init
2680 and NS16550_putc functions for the serial driver located at
2681 drivers/serial/ns16550.c. This option is useful for saving
2682 space for already greatly restricted images, including but not
2683 limited to NAND_SPL configurations.
2685 Low Level (hardware related) configuration options:
2686 ---------------------------------------------------
2688 - CONFIG_SYS_CACHELINE_SIZE:
2689 Cache Line Size of the CPU.
2691 - CONFIG_SYS_DEFAULT_IMMR:
2692 Default address of the IMMR after system reset.
2694 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU,
2695 and RPXsuper) to be able to adjust the position of
2696 the IMMR register after a reset.
2698 - Floppy Disk Support:
2699 CONFIG_SYS_FDC_DRIVE_NUMBER
2701 the default drive number (default value 0)
2703 CONFIG_SYS_ISA_IO_STRIDE
2705 defines the spacing between FDC chipset registers
2708 CONFIG_SYS_ISA_IO_OFFSET
2710 defines the offset of register from address. It
2711 depends on which part of the data bus is connected to
2712 the FDC chipset. (default value 0)
2714 If CONFIG_SYS_ISA_IO_STRIDE CONFIG_SYS_ISA_IO_OFFSET and
2715 CONFIG_SYS_FDC_DRIVE_NUMBER are undefined, they take their
2718 if CONFIG_SYS_FDC_HW_INIT is defined, then the function
2719 fdc_hw_init() is called at the beginning of the FDC
2720 setup. fdc_hw_init() must be provided by the board
2721 source code. It is used to make hardware dependant
2724 - CONFIG_SYS_IMMR: Physical address of the Internal Memory.
2725 DO NOT CHANGE unless you know exactly what you're
2726 doing! (11-4) [MPC8xx/82xx systems only]
2728 - CONFIG_SYS_INIT_RAM_ADDR:
2730 Start address of memory area that can be used for
2731 initial data and stack; please note that this must be
2732 writable memory that is working WITHOUT special
2733 initialization, i. e. you CANNOT use normal RAM which
2734 will become available only after programming the
2735 memory controller and running certain initialization
2738 U-Boot uses the following memory types:
2739 - MPC8xx and MPC8260: IMMR (internal memory of the CPU)
2740 - MPC824X: data cache
2741 - PPC4xx: data cache
2743 - CONFIG_SYS_GBL_DATA_OFFSET:
2745 Offset of the initial data structure in the memory
2746 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually
2747 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial
2748 data is located at the end of the available space
2749 (sometimes written as (CONFIG_SYS_INIT_RAM_SIZE -
2750 CONFIG_SYS_INIT_DATA_SIZE), and the initial stack is just
2751 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR +
2752 CONFIG_SYS_GBL_DATA_OFFSET) downward.
2755 On the MPC824X (or other systems that use the data
2756 cache for initial memory) the address chosen for
2757 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must
2758 point to an otherwise UNUSED address space between
2759 the top of RAM and the start of the PCI space.
2761 - CONFIG_SYS_SIUMCR: SIU Module Configuration (11-6)
2763 - CONFIG_SYS_SYPCR: System Protection Control (11-9)
2765 - CONFIG_SYS_TBSCR: Time Base Status and Control (11-26)
2767 - CONFIG_SYS_PISCR: Periodic Interrupt Status and Control (11-31)
2769 - CONFIG_SYS_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30)
2771 - CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27)
2773 - CONFIG_SYS_OR_TIMING_SDRAM:
2776 - CONFIG_SYS_MAMR_PTA:
2777 periodic timer for refresh
2779 - CONFIG_SYS_DER: Debug Event Register (37-47)
2781 - FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM,
2782 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP,
2783 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM,
2784 CONFIG_SYS_BR1_PRELIM:
2785 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
2787 - SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
2788 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM,
2789 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM:
2790 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
2792 - CONFIG_SYS_MAMR_PTA, CONFIG_SYS_MPTPR_2BK_4K, CONFIG_SYS_MPTPR_1BK_4K, CONFIG_SYS_MPTPR_2BK_8K,
2793 CONFIG_SYS_MPTPR_1BK_8K, CONFIG_SYS_MAMR_8COL, CONFIG_SYS_MAMR_9COL:
2794 Machine Mode Register and Memory Periodic Timer
2795 Prescaler definitions (SDRAM timing)
2797 - CONFIG_SYS_I2C_UCODE_PATCH, CONFIG_SYS_I2C_DPMEM_OFFSET [0x1FC0]:
2798 enable I2C microcode relocation patch (MPC8xx);
2799 define relocation offset in DPRAM [DSP2]
2801 - CONFIG_SYS_SMC_UCODE_PATCH, CONFIG_SYS_SMC_DPMEM_OFFSET [0x1FC0]:
2802 enable SMC microcode relocation patch (MPC8xx);
2803 define relocation offset in DPRAM [SMC1]
2805 - CONFIG_SYS_SPI_UCODE_PATCH, CONFIG_SYS_SPI_DPMEM_OFFSET [0x1FC0]:
2806 enable SPI microcode relocation patch (MPC8xx);
2807 define relocation offset in DPRAM [SCC4]
2809 - CONFIG_SYS_USE_OSCCLK:
2810 Use OSCM clock mode on MBX8xx board. Be careful,
2811 wrong setting might damage your board. Read
2812 doc/README.MBX before setting this variable!
2814 - CONFIG_SYS_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only)
2815 Offset of the bootmode word in DPRAM used by post
2816 (Power On Self Tests). This definition overrides
2817 #define'd default value in commproc.h resp.
2820 - CONFIG_SYS_PCI_SLV_MEM_LOCAL, CONFIG_SYS_PCI_SLV_MEM_BUS, CONFIG_SYS_PICMR0_MASK_ATTRIB,
2821 CONFIG_SYS_PCI_MSTR0_LOCAL, CONFIG_SYS_PCIMSK0_MASK, CONFIG_SYS_PCI_MSTR1_LOCAL,
2822 CONFIG_SYS_PCIMSK1_MASK, CONFIG_SYS_PCI_MSTR_MEM_LOCAL, CONFIG_SYS_PCI_MSTR_MEM_BUS,
2823 CONFIG_SYS_CPU_PCI_MEM_START, CONFIG_SYS_PCI_MSTR_MEM_SIZE, CONFIG_SYS_POCMR0_MASK_ATTRIB,
2824 CONFIG_SYS_PCI_MSTR_MEMIO_LOCAL, CONFIG_SYS_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START,
2825 CONFIG_SYS_PCI_MSTR_MEMIO_SIZE, CONFIG_SYS_POCMR1_MASK_ATTRIB, CONFIG_SYS_PCI_MSTR_IO_LOCAL,
2826 CONFIG_SYS_PCI_MSTR_IO_BUS, CONFIG_SYS_CPU_PCI_IO_START, CONFIG_SYS_PCI_MSTR_IO_SIZE,
2827 CONFIG_SYS_POCMR2_MASK_ATTRIB: (MPC826x only)
2828 Overrides the default PCI memory map in arch/powerpc/cpu/mpc8260/pci.c if set.
2830 - CONFIG_PCI_DISABLE_PCIE:
2831 Disable PCI-Express on systems where it is supported but not
2835 Chip has SRIO or not
2838 Board has SRIO 1 port available
2841 Board has SRIO 2 port available
2843 - CONFIG_SYS_SRIOn_MEM_VIRT:
2844 Virtual Address of SRIO port 'n' memory region
2846 - CONFIG_SYS_SRIOn_MEM_PHYS:
2847 Physical Address of SRIO port 'n' memory region
2849 - CONFIG_SYS_SRIOn_MEM_SIZE:
2850 Size of SRIO port 'n' memory region
2853 Get DDR timing information from an I2C EEPROM. Common
2854 with pluggable memory modules such as SODIMMs
2857 I2C address of the SPD EEPROM
2859 - CONFIG_SYS_SPD_BUS_NUM
2860 If SPD EEPROM is on an I2C bus other than the first
2861 one, specify here. Note that the value must resolve
2862 to something your driver can deal with.
2864 - CONFIG_SYS_83XX_DDR_USES_CS0
2865 Only for 83xx systems. If specified, then DDR should
2866 be configured using CS0 and CS1 instead of CS2 and CS3.
2868 - CONFIG_ETHER_ON_FEC[12]
2869 Define to enable FEC[12] on a 8xx series processor.
2871 - CONFIG_FEC[12]_PHY
2872 Define to the hardcoded PHY address which corresponds
2873 to the given FEC; i. e.
2874 #define CONFIG_FEC1_PHY 4
2875 means that the PHY with address 4 is connected to FEC1
2877 When set to -1, means to probe for first available.
2879 - CONFIG_FEC[12]_PHY_NORXERR
2880 The PHY does not have a RXERR line (RMII only).
2881 (so program the FEC to ignore it).
2884 Enable RMII mode for all FECs.
2885 Note that this is a global option, we can't
2886 have one FEC in standard MII mode and another in RMII mode.
2888 - CONFIG_CRC32_VERIFY
2889 Add a verify option to the crc32 command.
2892 => crc32 -v <address> <count> <crc32>
2894 Where address/count indicate a memory area
2895 and crc32 is the correct crc32 which the
2899 Add the "loopw" memory command. This only takes effect if
2900 the memory commands are activated globally (CONFIG_CMD_MEM).
2903 Add the "mdc" and "mwc" memory commands. These are cyclic
2908 This command will print 4 bytes (10,11,12,13) each 500 ms.
2910 => mwc.l 100 12345678 10
2911 This command will write 12345678 to address 100 all 10 ms.
2913 This only takes effect if the memory commands are activated
2914 globally (CONFIG_CMD_MEM).
2916 - CONFIG_SKIP_LOWLEVEL_INIT
2917 [ARM only] If this variable is defined, then certain
2918 low level initializations (like setting up the memory
2919 controller) are omitted and/or U-Boot does not
2920 relocate itself into RAM.
2922 Normally this variable MUST NOT be defined. The only
2923 exception is when U-Boot is loaded (to RAM) by some
2924 other boot loader or by a debugger which performs
2925 these initializations itself.
2928 Modifies the behaviour of start.S when compiling a loader
2929 that is executed before the actual U-Boot. E.g. when
2930 compiling a NAND SPL.
2932 Building the Software:
2933 ======================
2935 Building U-Boot has been tested in several native build environments
2936 and in many different cross environments. Of course we cannot support
2937 all possibly existing versions of cross development tools in all
2938 (potentially obsolete) versions. In case of tool chain problems we
2939 recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK)
2940 which is extensively used to build and test U-Boot.
2942 If you are not using a native environment, it is assumed that you
2943 have GNU cross compiling tools available in your path. In this case,
2944 you must set the environment variable CROSS_COMPILE in your shell.
2945 Note that no changes to the Makefile or any other source files are
2946 necessary. For example using the ELDK on a 4xx CPU, please enter:
2948 $ CROSS_COMPILE=ppc_4xx-
2949 $ export CROSS_COMPILE
2951 Note: If you wish to generate Windows versions of the utilities in
2952 the tools directory you can use the MinGW toolchain
2953 (http://www.mingw.org). Set your HOST tools to the MinGW
2954 toolchain and execute 'make tools'. For example:
2956 $ make HOSTCC=i586-mingw32msvc-gcc HOSTSTRIP=i586-mingw32msvc-strip tools
2958 Binaries such as tools/mkimage.exe will be created which can
2959 be executed on computers running Windows.
2961 U-Boot is intended to be simple to build. After installing the
2962 sources you must configure U-Boot for one specific board type. This
2967 where "NAME_config" is the name of one of the existing configu-
2968 rations; see the main Makefile for supported names.
2970 Note: for some board special configuration names may exist; check if
2971 additional information is available from the board vendor; for
2972 instance, the TQM823L systems are available without (standard)
2973 or with LCD support. You can select such additional "features"
2974 when choosing the configuration, i. e.
2977 - will configure for a plain TQM823L, i. e. no LCD support
2979 make TQM823L_LCD_config
2980 - will configure for a TQM823L with U-Boot console on LCD
2985 Finally, type "make all", and you should get some working U-Boot
2986 images ready for download to / installation on your system:
2988 - "u-boot.bin" is a raw binary image
2989 - "u-boot" is an image in ELF binary format
2990 - "u-boot.srec" is in Motorola S-Record format
2992 By default the build is performed locally and the objects are saved
2993 in the source directory. One of the two methods can be used to change
2994 this behavior and build U-Boot to some external directory:
2996 1. Add O= to the make command line invocations:
2998 make O=/tmp/build distclean
2999 make O=/tmp/build NAME_config
3000 make O=/tmp/build all
3002 2. Set environment variable BUILD_DIR to point to the desired location:
3004 export BUILD_DIR=/tmp/build
3009 Note that the command line "O=" setting overrides the BUILD_DIR environment
3013 Please be aware that the Makefiles assume you are using GNU make, so
3014 for instance on NetBSD you might need to use "gmake" instead of
3018 If the system board that you have is not listed, then you will need
3019 to port U-Boot to your hardware platform. To do this, follow these
3022 1. Add a new configuration option for your board to the toplevel
3023 "Makefile" and to the "MAKEALL" script, using the existing
3024 entries as examples. Note that here and at many other places
3025 boards and other names are listed in alphabetical sort order. Please
3027 2. Create a new directory to hold your board specific code. Add any
3028 files you need. In your board directory, you will need at least
3029 the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds".
3030 3. Create a new configuration file "include/configs/<board>.h" for
3032 3. If you're porting U-Boot to a new CPU, then also create a new
3033 directory to hold your CPU specific code. Add any files you need.
3034 4. Run "make <board>_config" with your new name.
3035 5. Type "make", and you should get a working "u-boot.srec" file
3036 to be installed on your target system.
3037 6. Debug and solve any problems that might arise.
3038 [Of course, this last step is much harder than it sounds.]
3041 Testing of U-Boot Modifications, Ports to New Hardware, etc.:
3042 ==============================================================
3044 If you have modified U-Boot sources (for instance added a new board
3045 or support for new devices, a new CPU, etc.) you are expected to
3046 provide feedback to the other developers. The feedback normally takes
3047 the form of a "patch", i. e. a context diff against a certain (latest
3048 official or latest in the git repository) version of U-Boot sources.
3050 But before you submit such a patch, please verify that your modifi-
3051 cation did not break existing code. At least make sure that *ALL* of
3052 the supported boards compile WITHOUT ANY compiler warnings. To do so,
3053 just run the "MAKEALL" script, which will configure and build U-Boot
3054 for ALL supported system. Be warned, this will take a while. You can
3055 select which (cross) compiler to use by passing a `CROSS_COMPILE'
3056 environment variable to the script, i. e. to use the ELDK cross tools
3059 CROSS_COMPILE=ppc_8xx- MAKEALL
3061 or to build on a native PowerPC system you can type
3063 CROSS_COMPILE=' ' MAKEALL
3065 When using the MAKEALL script, the default behaviour is to build
3066 U-Boot in the source directory. This location can be changed by
3067 setting the BUILD_DIR environment variable. Also, for each target
3068 built, the MAKEALL script saves two log files (<target>.ERR and
3069 <target>.MAKEALL) in the <source dir>/LOG directory. This default
3070 location can be changed by setting the MAKEALL_LOGDIR environment
3071 variable. For example:
3073 export BUILD_DIR=/tmp/build
3074 export MAKEALL_LOGDIR=/tmp/log
3075 CROSS_COMPILE=ppc_8xx- MAKEALL
3077 With the above settings build objects are saved in the /tmp/build,
3078 log files are saved in the /tmp/log and the source tree remains clean
3079 during the whole build process.
3082 See also "U-Boot Porting Guide" below.
3085 Monitor Commands - Overview:
3086 ============================
3088 go - start application at address 'addr'
3089 run - run commands in an environment variable
3090 bootm - boot application image from memory
3091 bootp - boot image via network using BootP/TFTP protocol
3092 tftpboot- boot image via network using TFTP protocol
3093 and env variables "ipaddr" and "serverip"
3094 (and eventually "gatewayip")
3095 rarpboot- boot image via network using RARP/TFTP protocol
3096 diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
3097 loads - load S-Record file over serial line
3098 loadb - load binary file over serial line (kermit mode)
3100 mm - memory modify (auto-incrementing)
3101 nm - memory modify (constant address)
3102 mw - memory write (fill)
3104 cmp - memory compare
3105 crc32 - checksum calculation
3106 i2c - I2C sub-system
3107 sspi - SPI utility commands
3108 base - print or set address offset
3109 printenv- print environment variables
3110 setenv - set environment variables
3111 saveenv - save environment variables to persistent storage
3112 protect - enable or disable FLASH write protection
3113 erase - erase FLASH memory
3114 flinfo - print FLASH memory information
3115 bdinfo - print Board Info structure
3116 iminfo - print header information for application image
3117 coninfo - print console devices and informations
3118 ide - IDE sub-system
3119 loop - infinite loop on address range
3120 loopw - infinite write loop on address range
3121 mtest - simple RAM test
3122 icache - enable or disable instruction cache
3123 dcache - enable or disable data cache
3124 reset - Perform RESET of the CPU
3125 echo - echo args to console
3126 version - print monitor version
3127 help - print online help
3128 ? - alias for 'help'
3131 Monitor Commands - Detailed Description:
3132 ========================================
3136 For now: just type "help <command>".
3139 Environment Variables:
3140 ======================
3142 U-Boot supports user configuration using Environment Variables which
3143 can be made persistent by saving to Flash memory.
3145 Environment Variables are set using "setenv", printed using
3146 "printenv", and saved to Flash using "saveenv". Using "setenv"
3147 without a value can be used to delete a variable from the
3148 environment. As long as you don't save the environment you are
3149 working with an in-memory copy. In case the Flash area containing the
3150 environment is erased by accident, a default environment is provided.
3152 Some configuration options can be set using Environment Variables.
3154 List of environment variables (most likely not complete):
3156 baudrate - see CONFIG_BAUDRATE
3158 bootdelay - see CONFIG_BOOTDELAY
3160 bootcmd - see CONFIG_BOOTCOMMAND
3162 bootargs - Boot arguments when booting an RTOS image
3164 bootfile - Name of the image to load with TFTP
3166 bootm_low - Memory range available for image processing in the bootm
3167 command can be restricted. This variable is given as
3168 a hexadecimal number and defines lowest address allowed
3169 for use by the bootm command. See also "bootm_size"
3170 environment variable. Address defined by "bootm_low" is
3171 also the base of the initial memory mapping for the Linux
3172 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ.
3174 bootm_size - Memory range available for image processing in the bootm
3175 command can be restricted. This variable is given as
3176 a hexadecimal number and defines the size of the region
3177 allowed for use by the bootm command. See also "bootm_low"
3178 environment variable.
3180 updatefile - Location of the software update file on a TFTP server, used
3181 by the automatic software update feature. Please refer to
3182 documentation in doc/README.update for more details.
3184 autoload - if set to "no" (any string beginning with 'n'),
3185 "bootp" will just load perform a lookup of the
3186 configuration from the BOOTP server, but not try to
3187 load any image using TFTP
3189 autostart - if set to "yes", an image loaded using the "bootp",
3190 "rarpboot", "tftpboot" or "diskboot" commands will
3191 be automatically started (by internally calling
3194 If set to "no", a standalone image passed to the
3195 "bootm" command will be copied to the load address
3196 (and eventually uncompressed), but NOT be started.
3197 This can be used to load and uncompress arbitrary
3200 i2cfast - (PPC405GP|PPC405EP only)
3201 if set to 'y' configures Linux I2C driver for fast
3202 mode (400kHZ). This environment variable is used in
3203 initialization code. So, for changes to be effective
3204 it must be saved and board must be reset.
3206 initrd_high - restrict positioning of initrd images:
3207 If this variable is not set, initrd images will be
3208 copied to the highest possible address in RAM; this
3209 is usually what you want since it allows for
3210 maximum initrd size. If for some reason you want to
3211 make sure that the initrd image is loaded below the
3212 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment
3213 variable to a value of "no" or "off" or "0".
3214 Alternatively, you can set it to a maximum upper
3215 address to use (U-Boot will still check that it
3216 does not overwrite the U-Boot stack and data).
3218 For instance, when you have a system with 16 MB
3219 RAM, and want to reserve 4 MB from use by Linux,
3220 you can do this by adding "mem=12M" to the value of
3221 the "bootargs" variable. However, now you must make
3222 sure that the initrd image is placed in the first
3223 12 MB as well - this can be done with
3225 setenv initrd_high 00c00000
3227 If you set initrd_high to 0xFFFFFFFF, this is an
3228 indication to U-Boot that all addresses are legal
3229 for the Linux kernel, including addresses in flash
3230 memory. In this case U-Boot will NOT COPY the
3231 ramdisk at all. This may be useful to reduce the
3232 boot time on your system, but requires that this
3233 feature is supported by your Linux kernel.
3235 ipaddr - IP address; needed for tftpboot command
3237 loadaddr - Default load address for commands like "bootp",
3238 "rarpboot", "tftpboot", "loadb" or "diskboot"
3240 loads_echo - see CONFIG_LOADS_ECHO
3242 serverip - TFTP server IP address; needed for tftpboot command
3244 bootretry - see CONFIG_BOOT_RETRY_TIME
3246 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
3248 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
3250 ethprime - When CONFIG_NET_MULTI is enabled controls which
3251 interface is used first.
3253 ethact - When CONFIG_NET_MULTI is enabled controls which
3254 interface is currently active. For example you
3255 can do the following
3257 => setenv ethact FEC
3258 => ping 192.168.0.1 # traffic sent on FEC
3259 => setenv ethact SCC
3260 => ping 10.0.0.1 # traffic sent on SCC
3262 ethrotate - When set to "no" U-Boot does not go through all
3263 available network interfaces.
3264 It just stays at the currently selected interface.
3266 netretry - When set to "no" each network operation will
3267 either succeed or fail without retrying.
3268 When set to "once" the network operation will
3269 fail when all the available network interfaces
3270 are tried once without success.
3271 Useful on scripts which control the retry operation
3274 npe_ucode - set load address for the NPE microcode
3276 tftpsrcport - If this is set, the value is used for TFTP's
3279 tftpdstport - If this is set, the value is used for TFTP's UDP
3280 destination port instead of the Well Know Port 69.
3282 tftpblocksize - Block size to use for TFTP transfers; if not set,
3283 we use the TFTP server's default block size
3285 tftptimeout - Retransmission timeout for TFTP packets (in milli-
3286 seconds, minimum value is 1000 = 1 second). Defines
3287 when a packet is considered to be lost so it has to
3288 be retransmitted. The default is 5000 = 5 seconds.
3289 Lowering this value may make downloads succeed
3290 faster in networks with high packet loss rates or
3291 with unreliable TFTP servers.
3293 vlan - When set to a value < 4095 the traffic over
3294 Ethernet is encapsulated/received over 802.1q
3297 The following environment variables may be used and automatically
3298 updated by the network boot commands ("bootp" and "rarpboot"),
3299 depending the information provided by your boot server:
3301 bootfile - see above
3302 dnsip - IP address of your Domain Name Server
3303 dnsip2 - IP address of your secondary Domain Name Server
3304 gatewayip - IP address of the Gateway (Router) to use
3305 hostname - Target hostname
3307 netmask - Subnet Mask
3308 rootpath - Pathname of the root filesystem on the NFS server
3309 serverip - see above
3312 There are two special Environment Variables:
3314 serial# - contains hardware identification information such
3315 as type string and/or serial number
3316 ethaddr - Ethernet address
3318 These variables can be set only once (usually during manufacturing of
3319 the board). U-Boot refuses to delete or overwrite these variables
3320 once they have been set once.
3323 Further special Environment Variables:
3325 ver - Contains the U-Boot version string as printed
3326 with the "version" command. This variable is
3327 readonly (see CONFIG_VERSION_VARIABLE).
3330 Please note that changes to some configuration parameters may take
3331 only effect after the next boot (yes, that's just like Windoze :-).
3334 Command Line Parsing:
3335 =====================
3337 There are two different command line parsers available with U-Boot:
3338 the old "simple" one, and the much more powerful "hush" shell:
3340 Old, simple command line parser:
3341 --------------------------------
3343 - supports environment variables (through setenv / saveenv commands)
3344 - several commands on one line, separated by ';'
3345 - variable substitution using "... ${name} ..." syntax
3346 - special characters ('$', ';') can be escaped by prefixing with '\',
3348 setenv bootcmd bootm \${address}
3349 - You can also escape text by enclosing in single apostrophes, for example:
3350 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
3355 - similar to Bourne shell, with control structures like
3356 if...then...else...fi, for...do...done; while...do...done,
3357 until...do...done, ...
3358 - supports environment ("global") variables (through setenv / saveenv
3359 commands) and local shell variables (through standard shell syntax
3360 "name=value"); only environment variables can be used with "run"
3366 (1) If a command line (or an environment variable executed by a "run"
3367 command) contains several commands separated by semicolon, and
3368 one of these commands fails, then the remaining commands will be
3371 (2) If you execute several variables with one call to run (i. e.
3372 calling run with a list of variables as arguments), any failing
3373 command will cause "run" to terminate, i. e. the remaining
3374 variables are not executed.
3376 Note for Redundant Ethernet Interfaces:
3377 =======================================
3379 Some boards come with redundant Ethernet interfaces; U-Boot supports
3380 such configurations and is capable of automatic selection of a
3381 "working" interface when needed. MAC assignment works as follows:
3383 Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
3384 MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
3385 "eth1addr" (=>eth1), "eth2addr", ...
3387 If the network interface stores some valid MAC address (for instance
3388 in SROM), this is used as default address if there is NO correspon-
3389 ding setting in the environment; if the corresponding environment
3390 variable is set, this overrides the settings in the card; that means:
3392 o If the SROM has a valid MAC address, and there is no address in the
3393 environment, the SROM's address is used.
3395 o If there is no valid address in the SROM, and a definition in the
3396 environment exists, then the value from the environment variable is
3399 o If both the SROM and the environment contain a MAC address, and
3400 both addresses are the same, this MAC address is used.
3402 o If both the SROM and the environment contain a MAC address, and the
3403 addresses differ, the value from the environment is used and a
3406 o If neither SROM nor the environment contain a MAC address, an error
3409 If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses
3410 will be programmed into hardware as part of the initialization process. This
3411 may be skipped by setting the appropriate 'ethmacskip' environment variable.
3412 The naming convention is as follows:
3413 "ethmacskip" (=>eth0), "eth1macskip" (=>eth1) etc.
3418 U-Boot is capable of booting (and performing other auxiliary operations on)
3419 images in two formats:
3421 New uImage format (FIT)
3422 -----------------------
3424 Flexible and powerful format based on Flattened Image Tree -- FIT (similar
3425 to Flattened Device Tree). It allows the use of images with multiple
3426 components (several kernels, ramdisks, etc.), with contents protected by
3427 SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory.
3433 Old image format is based on binary files which can be basically anything,
3434 preceded by a special header; see the definitions in include/image.h for
3435 details; basically, the header defines the following image properties:
3437 * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
3438 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
3439 LynxOS, pSOS, QNX, RTEMS, INTEGRITY;
3440 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS,
3442 * Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86,
3443 IA64, MIPS, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
3444 Currently supported: ARM, AVR32, Intel x86, MIPS, Nios II, PowerPC).
3445 * Compression Type (uncompressed, gzip, bzip2)
3451 The header is marked by a special Magic Number, and both the header
3452 and the data portions of the image are secured against corruption by
3459 Although U-Boot should support any OS or standalone application
3460 easily, the main focus has always been on Linux during the design of
3463 U-Boot includes many features that so far have been part of some
3464 special "boot loader" code within the Linux kernel. Also, any
3465 "initrd" images to be used are no longer part of one big Linux image;
3466 instead, kernel and "initrd" are separate images. This implementation
3467 serves several purposes:
3469 - the same features can be used for other OS or standalone
3470 applications (for instance: using compressed images to reduce the
3471 Flash memory footprint)
3473 - it becomes much easier to port new Linux kernel versions because
3474 lots of low-level, hardware dependent stuff are done by U-Boot
3476 - the same Linux kernel image can now be used with different "initrd"
3477 images; of course this also means that different kernel images can
3478 be run with the same "initrd". This makes testing easier (you don't
3479 have to build a new "zImage.initrd" Linux image when you just
3480 change a file in your "initrd"). Also, a field-upgrade of the
3481 software is easier now.
3487 Porting Linux to U-Boot based systems:
3488 ---------------------------------------
3490 U-Boot cannot save you from doing all the necessary modifications to
3491 configure the Linux device drivers for use with your target hardware
3492 (no, we don't intend to provide a full virtual machine interface to
3495 But now you can ignore ALL boot loader code (in arch/powerpc/mbxboot).
3497 Just make sure your machine specific header file (for instance
3498 include/asm-ppc/tqm8xx.h) includes the same definition of the Board
3499 Information structure as we define in include/asm-<arch>/u-boot.h,
3500 and make sure that your definition of IMAP_ADDR uses the same value
3501 as your U-Boot configuration in CONFIG_SYS_IMMR.
3504 Configuring the Linux kernel:
3505 -----------------------------
3507 No specific requirements for U-Boot. Make sure you have some root
3508 device (initial ramdisk, NFS) for your target system.
3511 Building a Linux Image:
3512 -----------------------
3514 With U-Boot, "normal" build targets like "zImage" or "bzImage" are
3515 not used. If you use recent kernel source, a new build target
3516 "uImage" will exist which automatically builds an image usable by
3517 U-Boot. Most older kernels also have support for a "pImage" target,
3518 which was introduced for our predecessor project PPCBoot and uses a
3519 100% compatible format.
3528 The "uImage" build target uses a special tool (in 'tools/mkimage') to
3529 encapsulate a compressed Linux kernel image with header information,
3530 CRC32 checksum etc. for use with U-Boot. This is what we are doing:
3532 * build a standard "vmlinux" kernel image (in ELF binary format):
3534 * convert the kernel into a raw binary image:
3536 ${CROSS_COMPILE}-objcopy -O binary \
3537 -R .note -R .comment \
3538 -S vmlinux linux.bin
3540 * compress the binary image:
3544 * package compressed binary image for U-Boot:
3546 mkimage -A ppc -O linux -T kernel -C gzip \
3547 -a 0 -e 0 -n "Linux Kernel Image" \
3548 -d linux.bin.gz uImage
3551 The "mkimage" tool can also be used to create ramdisk images for use
3552 with U-Boot, either separated from the Linux kernel image, or
3553 combined into one file. "mkimage" encapsulates the images with a 64
3554 byte header containing information about target architecture,
3555 operating system, image type, compression method, entry points, time
3556 stamp, CRC32 checksums, etc.
3558 "mkimage" can be called in two ways: to verify existing images and
3559 print the header information, or to build new images.
3561 In the first form (with "-l" option) mkimage lists the information
3562 contained in the header of an existing U-Boot image; this includes
3563 checksum verification:
3565 tools/mkimage -l image
3566 -l ==> list image header information
3568 The second form (with "-d" option) is used to build a U-Boot image
3569 from a "data file" which is used as image payload:
3571 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
3572 -n name -d data_file image
3573 -A ==> set architecture to 'arch'
3574 -O ==> set operating system to 'os'
3575 -T ==> set image type to 'type'
3576 -C ==> set compression type 'comp'
3577 -a ==> set load address to 'addr' (hex)
3578 -e ==> set entry point to 'ep' (hex)
3579 -n ==> set image name to 'name'
3580 -d ==> use image data from 'datafile'
3582 Right now, all Linux kernels for PowerPC systems use the same load
3583 address (0x00000000), but the entry point address depends on the
3586 - 2.2.x kernels have the entry point at 0x0000000C,
3587 - 2.3.x and later kernels have the entry point at 0x00000000.
3589 So a typical call to build a U-Boot image would read:
3591 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
3592 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
3593 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz \
3594 > examples/uImage.TQM850L
3595 Image Name: 2.4.4 kernel for TQM850L
3596 Created: Wed Jul 19 02:34:59 2000
3597 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3598 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
3599 Load Address: 0x00000000
3600 Entry Point: 0x00000000
3602 To verify the contents of the image (or check for corruption):
3604 -> tools/mkimage -l examples/uImage.TQM850L
3605 Image Name: 2.4.4 kernel for TQM850L
3606 Created: Wed Jul 19 02:34:59 2000
3607 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3608 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
3609 Load Address: 0x00000000
3610 Entry Point: 0x00000000
3612 NOTE: for embedded systems where boot time is critical you can trade
3613 speed for memory and install an UNCOMPRESSED image instead: this
3614 needs more space in Flash, but boots much faster since it does not
3615 need to be uncompressed:
3617 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz
3618 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
3619 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
3620 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux \
3621 > examples/uImage.TQM850L-uncompressed
3622 Image Name: 2.4.4 kernel for TQM850L
3623 Created: Wed Jul 19 02:34:59 2000
3624 Image Type: PowerPC Linux Kernel Image (uncompressed)
3625 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
3626 Load Address: 0x00000000
3627 Entry Point: 0x00000000
3630 Similar you can build U-Boot images from a 'ramdisk.image.gz' file
3631 when your kernel is intended to use an initial ramdisk:
3633 -> tools/mkimage -n 'Simple Ramdisk Image' \
3634 > -A ppc -O linux -T ramdisk -C gzip \
3635 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
3636 Image Name: Simple Ramdisk Image
3637 Created: Wed Jan 12 14:01:50 2000
3638 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
3639 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
3640 Load Address: 0x00000000
3641 Entry Point: 0x00000000
3644 Installing a Linux Image:
3645 -------------------------
3647 To downloading a U-Boot image over the serial (console) interface,
3648 you must convert the image to S-Record format:
3650 objcopy -I binary -O srec examples/image examples/image.srec
3652 The 'objcopy' does not understand the information in the U-Boot
3653 image header, so the resulting S-Record file will be relative to
3654 address 0x00000000. To load it to a given address, you need to
3655 specify the target address as 'offset' parameter with the 'loads'
3658 Example: install the image to address 0x40100000 (which on the
3659 TQM8xxL is in the first Flash bank):
3661 => erase 40100000 401FFFFF
3667 ## Ready for S-Record download ...
3668 ~>examples/image.srec
3669 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
3671 15989 15990 15991 15992
3672 [file transfer complete]
3674 ## Start Addr = 0x00000000
3677 You can check the success of the download using the 'iminfo' command;
3678 this includes a checksum verification so you can be sure no data
3679 corruption happened:
3683 ## Checking Image at 40100000 ...
3684 Image Name: 2.2.13 for initrd on TQM850L
3685 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3686 Data Size: 335725 Bytes = 327 kB = 0 MB
3687 Load Address: 00000000
3688 Entry Point: 0000000c
3689 Verifying Checksum ... OK
3695 The "bootm" command is used to boot an application that is stored in
3696 memory (RAM or Flash). In case of a Linux kernel image, the contents
3697 of the "bootargs" environment variable is passed to the kernel as
3698 parameters. You can check and modify this variable using the
3699 "printenv" and "setenv" commands:
3702 => printenv bootargs
3703 bootargs=root=/dev/ram
3705 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
3707 => printenv bootargs
3708 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
3711 ## Booting Linux kernel at 40020000 ...
3712 Image Name: 2.2.13 for NFS on TQM850L
3713 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3714 Data Size: 381681 Bytes = 372 kB = 0 MB
3715 Load Address: 00000000
3716 Entry Point: 0000000c
3717 Verifying Checksum ... OK
3718 Uncompressing Kernel Image ... OK
3719 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
3720 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
3721 time_init: decrementer frequency = 187500000/60
3722 Calibrating delay loop... 49.77 BogoMIPS
3723 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
3726 If you want to boot a Linux kernel with initial RAM disk, you pass
3727 the memory addresses of both the kernel and the initrd image (PPBCOOT
3728 format!) to the "bootm" command:
3730 => imi 40100000 40200000
3732 ## Checking Image at 40100000 ...
3733 Image Name: 2.2.13 for initrd on TQM850L
3734 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3735 Data Size: 335725 Bytes = 327 kB = 0 MB
3736 Load Address: 00000000
3737 Entry Point: 0000000c
3738 Verifying Checksum ... OK
3740 ## Checking Image at 40200000 ...
3741 Image Name: Simple Ramdisk Image
3742 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
3743 Data Size: 566530 Bytes = 553 kB = 0 MB
3744 Load Address: 00000000
3745 Entry Point: 00000000
3746 Verifying Checksum ... OK
3748 => bootm 40100000 40200000
3749 ## Booting Linux kernel at 40100000 ...
3750 Image Name: 2.2.13 for initrd on TQM850L
3751 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3752 Data Size: 335725 Bytes = 327 kB = 0 MB
3753 Load Address: 00000000
3754 Entry Point: 0000000c
3755 Verifying Checksum ... OK
3756 Uncompressing Kernel Image ... OK
3757 ## Loading RAMDisk Image at 40200000 ...
3758 Image Name: Simple Ramdisk Image
3759 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
3760 Data Size: 566530 Bytes = 553 kB = 0 MB
3761 Load Address: 00000000
3762 Entry Point: 00000000
3763 Verifying Checksum ... OK
3764 Loading Ramdisk ... OK
3765 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
3766 Boot arguments: root=/dev/ram
3767 time_init: decrementer frequency = 187500000/60
3768 Calibrating delay loop... 49.77 BogoMIPS
3770 RAMDISK: Compressed image found at block 0
3771 VFS: Mounted root (ext2 filesystem).
3775 Boot Linux and pass a flat device tree:
3778 First, U-Boot must be compiled with the appropriate defines. See the section
3779 titled "Linux Kernel Interface" above for a more in depth explanation. The
3780 following is an example of how to start a kernel and pass an updated
3786 oft=oftrees/mpc8540ads.dtb
3787 => tftp $oftaddr $oft
3788 Speed: 1000, full duplex
3790 TFTP from server 192.168.1.1; our IP address is 192.168.1.101
3791 Filename 'oftrees/mpc8540ads.dtb'.
3792 Load address: 0x300000
3795 Bytes transferred = 4106 (100a hex)
3796 => tftp $loadaddr $bootfile
3797 Speed: 1000, full duplex
3799 TFTP from server 192.168.1.1; our IP address is 192.168.1.2
3801 Load address: 0x200000
3802 Loading:############
3804 Bytes transferred = 1029407 (fb51f hex)
3809 => bootm $loadaddr - $oftaddr
3810 ## Booting image at 00200000 ...
3811 Image Name: Linux-2.6.17-dirty
3812 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3813 Data Size: 1029343 Bytes = 1005.2 kB
3814 Load Address: 00000000
3815 Entry Point: 00000000
3816 Verifying Checksum ... OK
3817 Uncompressing Kernel Image ... OK
3818 Booting using flat device tree at 0x300000
3819 Using MPC85xx ADS machine description
3820 Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb
3824 More About U-Boot Image Types:
3825 ------------------------------
3827 U-Boot supports the following image types:
3829 "Standalone Programs" are directly runnable in the environment
3830 provided by U-Boot; it is expected that (if they behave
3831 well) you can continue to work in U-Boot after return from
3832 the Standalone Program.
3833 "OS Kernel Images" are usually images of some Embedded OS which
3834 will take over control completely. Usually these programs
3835 will install their own set of exception handlers, device
3836 drivers, set up the MMU, etc. - this means, that you cannot
3837 expect to re-enter U-Boot except by resetting the CPU.
3838 "RAMDisk Images" are more or less just data blocks, and their
3839 parameters (address, size) are passed to an OS kernel that is
3841 "Multi-File Images" contain several images, typically an OS
3842 (Linux) kernel image and one or more data images like
3843 RAMDisks. This construct is useful for instance when you want
3844 to boot over the network using BOOTP etc., where the boot
3845 server provides just a single image file, but you want to get
3846 for instance an OS kernel and a RAMDisk image.
3848 "Multi-File Images" start with a list of image sizes, each
3849 image size (in bytes) specified by an "uint32_t" in network
3850 byte order. This list is terminated by an "(uint32_t)0".
3851 Immediately after the terminating 0 follow the images, one by
3852 one, all aligned on "uint32_t" boundaries (size rounded up to
3853 a multiple of 4 bytes).
3855 "Firmware Images" are binary images containing firmware (like
3856 U-Boot or FPGA images) which usually will be programmed to
3859 "Script files" are command sequences that will be executed by
3860 U-Boot's command interpreter; this feature is especially
3861 useful when you configure U-Boot to use a real shell (hush)
3862 as command interpreter.
3868 One of the features of U-Boot is that you can dynamically load and
3869 run "standalone" applications, which can use some resources of
3870 U-Boot like console I/O functions or interrupt services.
3872 Two simple examples are included with the sources:
3877 'examples/hello_world.c' contains a small "Hello World" Demo
3878 application; it is automatically compiled when you build U-Boot.
3879 It's configured to run at address 0x00040004, so you can play with it
3883 ## Ready for S-Record download ...
3884 ~>examples/hello_world.srec
3885 1 2 3 4 5 6 7 8 9 10 11 ...
3886 [file transfer complete]
3888 ## Start Addr = 0x00040004
3890 => go 40004 Hello World! This is a test.
3891 ## Starting application at 0x00040004 ...
3902 Hit any key to exit ...
3904 ## Application terminated, rc = 0x0
3906 Another example, which demonstrates how to register a CPM interrupt
3907 handler with the U-Boot code, can be found in 'examples/timer.c'.
3908 Here, a CPM timer is set up to generate an interrupt every second.
3909 The interrupt service routine is trivial, just printing a '.'
3910 character, but this is just a demo program. The application can be
3911 controlled by the following keys:
3913 ? - print current values og the CPM Timer registers
3914 b - enable interrupts and start timer
3915 e - stop timer and disable interrupts
3916 q - quit application
3919 ## Ready for S-Record download ...
3920 ~>examples/timer.srec
3921 1 2 3 4 5 6 7 8 9 10 11 ...
3922 [file transfer complete]
3924 ## Start Addr = 0x00040004
3927 ## Starting application at 0x00040004 ...
3930 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
3933 [q, b, e, ?] Set interval 1000000 us
3936 [q, b, e, ?] ........
3937 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
3940 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
3943 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
3946 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
3948 [q, b, e, ?] ...Stopping timer
3950 [q, b, e, ?] ## Application terminated, rc = 0x0
3956 Over time, many people have reported problems when trying to use the
3957 "minicom" terminal emulation program for serial download. I (wd)
3958 consider minicom to be broken, and recommend not to use it. Under
3959 Unix, I recommend to use C-Kermit for general purpose use (and
3960 especially for kermit binary protocol download ("loadb" command), and
3961 use "cu" for S-Record download ("loads" command).
3963 Nevertheless, if you absolutely want to use it try adding this
3964 configuration to your "File transfer protocols" section:
3966 Name Program Name U/D FullScr IO-Red. Multi
3967 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
3968 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
3974 Starting at version 0.9.2, U-Boot supports NetBSD both as host
3975 (build U-Boot) and target system (boots NetBSD/mpc8xx).
3977 Building requires a cross environment; it is known to work on
3978 NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
3979 need gmake since the Makefiles are not compatible with BSD make).
3980 Note that the cross-powerpc package does not install include files;
3981 attempting to build U-Boot will fail because <machine/ansi.h> is
3982 missing. This file has to be installed and patched manually:
3984 # cd /usr/pkg/cross/powerpc-netbsd/include
3986 # ln -s powerpc machine
3987 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
3988 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
3990 Native builds *don't* work due to incompatibilities between native
3991 and U-Boot include files.
3993 Booting assumes that (the first part of) the image booted is a
3994 stage-2 loader which in turn loads and then invokes the kernel
3995 proper. Loader sources will eventually appear in the NetBSD source
3996 tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
3997 meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz
4000 Implementation Internals:
4001 =========================
4003 The following is not intended to be a complete description of every
4004 implementation detail. However, it should help to understand the
4005 inner workings of U-Boot and make it easier to port it to custom
4009 Initial Stack, Global Data:
4010 ---------------------------
4012 The implementation of U-Boot is complicated by the fact that U-Boot
4013 starts running out of ROM (flash memory), usually without access to
4014 system RAM (because the memory controller is not initialized yet).
4015 This means that we don't have writable Data or BSS segments, and BSS
4016 is not initialized as zero. To be able to get a C environment working
4017 at all, we have to allocate at least a minimal stack. Implementation
4018 options for this are defined and restricted by the CPU used: Some CPU
4019 models provide on-chip memory (like the IMMR area on MPC8xx and
4020 MPC826x processors), on others (parts of) the data cache can be
4021 locked as (mis-) used as memory, etc.
4023 Chris Hallinan posted a good summary of these issues to the
4024 U-Boot mailing list:
4026 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
4027 From: "Chris Hallinan" <clh@net1plus.com>
4028 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
4031 Correct me if I'm wrong, folks, but the way I understand it
4032 is this: Using DCACHE as initial RAM for Stack, etc, does not
4033 require any physical RAM backing up the cache. The cleverness
4034 is that the cache is being used as a temporary supply of
4035 necessary storage before the SDRAM controller is setup. It's
4036 beyond the scope of this list to explain the details, but you
4037 can see how this works by studying the cache architecture and
4038 operation in the architecture and processor-specific manuals.
4040 OCM is On Chip Memory, which I believe the 405GP has 4K. It
4041 is another option for the system designer to use as an
4042 initial stack/RAM area prior to SDRAM being available. Either
4043 option should work for you. Using CS 4 should be fine if your
4044 board designers haven't used it for something that would
4045 cause you grief during the initial boot! It is frequently not
4048 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere
4049 with your processor/board/system design. The default value
4050 you will find in any recent u-boot distribution in
4051 walnut.h should work for you. I'd set it to a value larger
4052 than your SDRAM module. If you have a 64MB SDRAM module, set
4053 it above 400_0000. Just make sure your board has no resources
4054 that are supposed to respond to that address! That code in
4055 start.S has been around a while and should work as is when
4056 you get the config right.
4061 It is essential to remember this, since it has some impact on the C
4062 code for the initialization procedures:
4064 * Initialized global data (data segment) is read-only. Do not attempt
4067 * Do not use any uninitialized global data (or implicitely initialized
4068 as zero data - BSS segment) at all - this is undefined, initiali-
4069 zation is performed later (when relocating to RAM).
4071 * Stack space is very limited. Avoid big data buffers or things like
4074 Having only the stack as writable memory limits means we cannot use
4075 normal global data to share information beween the code. But it
4076 turned out that the implementation of U-Boot can be greatly
4077 simplified by making a global data structure (gd_t) available to all
4078 functions. We could pass a pointer to this data as argument to _all_
4079 functions, but this would bloat the code. Instead we use a feature of
4080 the GCC compiler (Global Register Variables) to share the data: we
4081 place a pointer (gd) to the global data into a register which we
4082 reserve for this purpose.
4084 When choosing a register for such a purpose we are restricted by the
4085 relevant (E)ABI specifications for the current architecture, and by
4086 GCC's implementation.
4088 For PowerPC, the following registers have specific use:
4090 R2: reserved for system use
4091 R3-R4: parameter passing and return values
4092 R5-R10: parameter passing
4093 R13: small data area pointer
4097 (U-Boot also uses R12 as internal GOT pointer. r12
4098 is a volatile register so r12 needs to be reset when
4099 going back and forth between asm and C)
4101 ==> U-Boot will use R2 to hold a pointer to the global data
4103 Note: on PPC, we could use a static initializer (since the
4104 address of the global data structure is known at compile time),
4105 but it turned out that reserving a register results in somewhat
4106 smaller code - although the code savings are not that big (on
4107 average for all boards 752 bytes for the whole U-Boot image,
4108 624 text + 127 data).
4110 On Blackfin, the normal C ABI (except for P3) is followed as documented here:
4111 http://docs.blackfin.uclinux.org/doku.php?id=application_binary_interface
4113 ==> U-Boot will use P3 to hold a pointer to the global data
4115 On ARM, the following registers are used:
4117 R0: function argument word/integer result
4118 R1-R3: function argument word
4120 R10: stack limit (used only if stack checking if enabled)
4121 R11: argument (frame) pointer
4122 R12: temporary workspace
4125 R15: program counter
4127 ==> U-Boot will use R8 to hold a pointer to the global data
4129 On Nios II, the ABI is documented here:
4130 http://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf
4132 ==> U-Boot will use gp to hold a pointer to the global data
4134 Note: on Nios II, we give "-G0" option to gcc and don't use gp
4135 to access small data sections, so gp is free.
4137 NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope,
4138 or current versions of GCC may "optimize" the code too much.
4143 U-Boot runs in system state and uses physical addresses, i.e. the
4144 MMU is not used either for address mapping nor for memory protection.
4146 The available memory is mapped to fixed addresses using the memory
4147 controller. In this process, a contiguous block is formed for each
4148 memory type (Flash, SDRAM, SRAM), even when it consists of several
4149 physical memory banks.
4151 U-Boot is installed in the first 128 kB of the first Flash bank (on
4152 TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
4153 booting and sizing and initializing DRAM, the code relocates itself
4154 to the upper end of DRAM. Immediately below the U-Boot code some
4155 memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN
4156 configuration setting]. Below that, a structure with global Board
4157 Info data is placed, followed by the stack (growing downward).
4159 Additionally, some exception handler code is copied to the low 8 kB
4160 of DRAM (0x00000000 ... 0x00001FFF).
4162 So a typical memory configuration with 16 MB of DRAM could look like
4165 0x0000 0000 Exception Vector code
4168 0x0000 2000 Free for Application Use
4174 0x00FB FF20 Monitor Stack (Growing downward)
4175 0x00FB FFAC Board Info Data and permanent copy of global data
4176 0x00FC 0000 Malloc Arena
4179 0x00FE 0000 RAM Copy of Monitor Code
4180 ... eventually: LCD or video framebuffer
4181 ... eventually: pRAM (Protected RAM - unchanged by reset)
4182 0x00FF FFFF [End of RAM]
4185 System Initialization:
4186 ----------------------
4188 In the reset configuration, U-Boot starts at the reset entry point
4189 (on most PowerPC systems at address 0x00000100). Because of the reset
4190 configuration for CS0# this is a mirror of the onboard Flash memory.
4191 To be able to re-map memory U-Boot then jumps to its link address.
4192 To be able to implement the initialization code in C, a (small!)
4193 initial stack is set up in the internal Dual Ported RAM (in case CPUs
4194 which provide such a feature like MPC8xx or MPC8260), or in a locked
4195 part of the data cache. After that, U-Boot initializes the CPU core,
4196 the caches and the SIU.
4198 Next, all (potentially) available memory banks are mapped using a
4199 preliminary mapping. For example, we put them on 512 MB boundaries
4200 (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
4201 on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
4202 programmed for SDRAM access. Using the temporary configuration, a
4203 simple memory test is run that determines the size of the SDRAM
4206 When there is more than one SDRAM bank, and the banks are of
4207 different size, the largest is mapped first. For equal size, the first
4208 bank (CS2#) is mapped first. The first mapping is always for address
4209 0x00000000, with any additional banks following immediately to create
4210 contiguous memory starting from 0.
4212 Then, the monitor installs itself at the upper end of the SDRAM area
4213 and allocates memory for use by malloc() and for the global Board
4214 Info data; also, the exception vector code is copied to the low RAM
4215 pages, and the final stack is set up.
4217 Only after this relocation will you have a "normal" C environment;
4218 until that you are restricted in several ways, mostly because you are
4219 running from ROM, and because the code will have to be relocated to a
4223 U-Boot Porting Guide:
4224 ----------------------
4226 [Based on messages by Jerry Van Baren in the U-Boot-Users mailing
4230 int main(int argc, char *argv[])
4232 sighandler_t no_more_time;
4234 signal(SIGALRM, no_more_time);
4235 alarm(PROJECT_DEADLINE - toSec (3 * WEEK));
4237 if (available_money > available_manpower) {
4238 Pay consultant to port U-Boot;
4242 Download latest U-Boot source;
4244 Subscribe to u-boot mailing list;
4247 email("Hi, I am new to U-Boot, how do I get started?");
4250 Read the README file in the top level directory;
4251 Read http://www.denx.de/twiki/bin/view/DULG/Manual;
4252 Read applicable doc/*.README;
4253 Read the source, Luke;
4254 /* find . -name "*.[chS]" | xargs grep -i <keyword> */
4257 if (available_money > toLocalCurrency ($2500))
4260 Add a lot of aggravation and time;
4262 if (a similar board exists) { /* hopefully... */
4263 cp -a board/<similar> board/<myboard>
4264 cp include/configs/<similar>.h include/configs/<myboard>.h
4266 Create your own board support subdirectory;
4267 Create your own board include/configs/<myboard>.h file;
4269 Edit new board/<myboard> files
4270 Edit new include/configs/<myboard>.h
4275 Add / modify source code;
4279 email("Hi, I am having problems...");
4281 Send patch file to the U-Boot email list;
4282 if (reasonable critiques)
4283 Incorporate improvements from email list code review;
4285 Defend code as written;
4291 void no_more_time (int sig)
4300 All contributions to U-Boot should conform to the Linux kernel
4301 coding style; see the file "Documentation/CodingStyle" and the script
4302 "scripts/Lindent" in your Linux kernel source directory. In sources
4303 originating from U-Boot a style corresponding to "Lindent -pcs" (adding
4304 spaces before parameters to function calls) is actually used.
4306 Source files originating from a different project (for example the
4307 MTD subsystem) are generally exempt from these guidelines and are not
4308 reformated to ease subsequent migration to newer versions of those
4311 Please note that U-Boot is implemented in C (and to some small parts in
4312 Assembler); no C++ is used, so please do not use C++ style comments (//)
4315 Please also stick to the following formatting rules:
4316 - remove any trailing white space
4317 - use TAB characters for indentation, not spaces
4318 - make sure NOT to use DOS '\r\n' line feeds
4319 - do not add more than 2 empty lines to source files
4320 - do not add trailing empty lines to source files
4322 Submissions which do not conform to the standards may be returned
4323 with a request to reformat the changes.
4329 Since the number of patches for U-Boot is growing, we need to
4330 establish some rules. Submissions which do not conform to these rules
4331 may be rejected, even when they contain important and valuable stuff.
4333 Please see http://www.denx.de/wiki/U-Boot/Patches for details.
4335 Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>;
4336 see http://lists.denx.de/mailman/listinfo/u-boot
4338 When you send a patch, please include the following information with
4341 * For bug fixes: a description of the bug and how your patch fixes
4342 this bug. Please try to include a way of demonstrating that the
4343 patch actually fixes something.
4345 * For new features: a description of the feature and your
4348 * A CHANGELOG entry as plaintext (separate from the patch)
4350 * For major contributions, your entry to the CREDITS file
4352 * When you add support for a new board, don't forget to add this
4353 board to the MAKEALL script, too.
4355 * If your patch adds new configuration options, don't forget to
4356 document these in the README file.
4358 * The patch itself. If you are using git (which is *strongly*
4359 recommended) you can easily generate the patch using the
4360 "git-format-patch". If you then use "git-send-email" to send it to
4361 the U-Boot mailing list, you will avoid most of the common problems
4362 with some other mail clients.
4364 If you cannot use git, use "diff -purN OLD NEW". If your version of
4365 diff does not support these options, then get the latest version of
4368 The current directory when running this command shall be the parent
4369 directory of the U-Boot source tree (i. e. please make sure that
4370 your patch includes sufficient directory information for the
4373 We prefer patches as plain text. MIME attachments are discouraged,
4374 and compressed attachments must not be used.
4376 * If one logical set of modifications affects or creates several
4377 files, all these changes shall be submitted in a SINGLE patch file.
4379 * Changesets that contain different, unrelated modifications shall be
4380 submitted as SEPARATE patches, one patch per changeset.
4385 * Before sending the patch, run the MAKEALL script on your patched
4386 source tree and make sure that no errors or warnings are reported
4387 for any of the boards.
4389 * Keep your modifications to the necessary minimum: A patch
4390 containing several unrelated changes or arbitrary reformats will be
4391 returned with a request to re-formatting / split it.
4393 * If you modify existing code, make sure that your new code does not
4394 add to the memory footprint of the code ;-) Small is beautiful!
4395 When adding new features, these should compile conditionally only
4396 (using #ifdef), and the resulting code with the new feature
4397 disabled must not need more memory than the old code without your
4400 * Remember that there is a size limit of 100 kB per message on the
4401 u-boot mailing list. Bigger patches will be moderated. If they are
4402 reasonable and not too big, they will be acknowledged. But patches
4403 bigger than the size limit should be avoided.
projects / platform / kernel / u-boot.git / blob