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_EXPORTENV * export the environment
641 CONFIG_CMD_SAVEENV saveenv
642 CONFIG_CMD_FDC * Floppy Disk Support
643 CONFIG_CMD_FAT * FAT partition support
644 CONFIG_CMD_FDOS * Dos diskette Support
645 CONFIG_CMD_FLASH flinfo, erase, protect
646 CONFIG_CMD_FPGA FPGA device initialization support
647 CONFIG_CMD_HWFLOW * RTS/CTS hw flow control
648 CONFIG_CMD_I2C * I2C serial bus support
649 CONFIG_CMD_IDE * IDE harddisk support
650 CONFIG_CMD_IMI iminfo
651 CONFIG_CMD_IMLS List all found images
652 CONFIG_CMD_IMMAP * IMMR dump support
653 CONFIG_CMD_IMPORTENV * import an environment
654 CONFIG_CMD_IRQ * irqinfo
655 CONFIG_CMD_ITEST Integer/string test of 2 values
656 CONFIG_CMD_JFFS2 * JFFS2 Support
657 CONFIG_CMD_KGDB * kgdb
658 CONFIG_CMD_LDRINFO ldrinfo (display Blackfin loader)
659 CONFIG_CMD_LOADB loadb
660 CONFIG_CMD_LOADS loads
661 CONFIG_CMD_MD5SUM print md5 message digest
662 (requires CONFIG_CMD_MEMORY and CONFIG_MD5)
663 CONFIG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base,
665 CONFIG_CMD_MISC Misc functions like sleep etc
666 CONFIG_CMD_MMC * MMC memory mapped support
667 CONFIG_CMD_MII * MII utility commands
668 CONFIG_CMD_MTDPARTS * MTD partition support
669 CONFIG_CMD_NAND * NAND support
670 CONFIG_CMD_NET bootp, tftpboot, rarpboot
671 CONFIG_CMD_PCA953X * PCA953x I2C gpio commands
672 CONFIG_CMD_PCA953X_INFO * PCA953x I2C gpio info command
673 CONFIG_CMD_PCI * pciinfo
674 CONFIG_CMD_PCMCIA * PCMCIA support
675 CONFIG_CMD_PING * send ICMP ECHO_REQUEST to network
677 CONFIG_CMD_PORTIO * Port I/O
678 CONFIG_CMD_REGINFO * Register dump
679 CONFIG_CMD_RUN run command in env variable
680 CONFIG_CMD_SAVES * save S record dump
681 CONFIG_CMD_SCSI * SCSI Support
682 CONFIG_CMD_SDRAM * print SDRAM configuration information
683 (requires CONFIG_CMD_I2C)
684 CONFIG_CMD_SETGETDCR Support for DCR Register access
686 CONFIG_CMD_SHA1SUM print sha1 memory digest
687 (requires CONFIG_CMD_MEMORY)
688 CONFIG_CMD_SOURCE "source" command Support
689 CONFIG_CMD_SPI * SPI serial bus support
690 CONFIG_CMD_USB * USB support
691 CONFIG_CMD_VFD * VFD support (TRAB)
692 CONFIG_CMD_CDP * Cisco Discover Protocol support
693 CONFIG_CMD_FSL * Microblaze FSL support
696 EXAMPLE: If you want all functions except of network
697 support you can write:
699 #include "config_cmd_all.h"
700 #undef CONFIG_CMD_NET
703 fdt (flattened device tree) command: CONFIG_OF_LIBFDT
705 Note: Don't enable the "icache" and "dcache" commands
706 (configuration option CONFIG_CMD_CACHE) unless you know
707 what you (and your U-Boot users) are doing. Data
708 cache cannot be enabled on systems like the 8xx or
709 8260 (where accesses to the IMMR region must be
710 uncached), and it cannot be disabled on all other
711 systems where we (mis-) use the data cache to hold an
712 initial stack and some data.
715 XXX - this list needs to get updated!
719 If this variable is defined, it enables watchdog
720 support. There must be support in the platform specific
721 code for a watchdog. For the 8xx and 8260 CPUs, the
722 SIU Watchdog feature is enabled in the SYPCR
726 CONFIG_VERSION_VARIABLE
727 If this variable is defined, an environment variable
728 named "ver" is created by U-Boot showing the U-Boot
729 version as printed by the "version" command.
730 This variable is readonly.
734 When CONFIG_CMD_DATE is selected, the type of the RTC
735 has to be selected, too. Define exactly one of the
738 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx
739 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC
740 CONFIG_RTC_MC13783 - use MC13783 RTC
741 CONFIG_RTC_MC146818 - use MC146818 RTC
742 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC
743 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC
744 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC
745 CONFIG_RTC_DS164x - use Dallas DS164x RTC
746 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC
747 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC
748 CONFIG_SYS_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337
750 Note that if the RTC uses I2C, then the I2C interface
751 must also be configured. See I2C Support, below.
754 CONFIG_PCA953X - use NXP's PCA953X series I2C GPIO
755 CONFIG_PCA953X_INFO - enable pca953x info command
757 The CONFIG_SYS_I2C_PCA953X_WIDTH option specifies a list of
758 chip-ngpio pairs that tell the PCA953X driver the number of
759 pins supported by a particular chip.
761 Note that if the GPIO device uses I2C, then the I2C interface
762 must also be configured. See I2C Support, below.
766 When CONFIG_TIMESTAMP is selected, the timestamp
767 (date and time) of an image is printed by image
768 commands like bootm or iminfo. This option is
769 automatically enabled when you select CONFIG_CMD_DATE .
772 CONFIG_MAC_PARTITION and/or CONFIG_DOS_PARTITION
773 and/or CONFIG_ISO_PARTITION and/or CONFIG_EFI_PARTITION
775 If IDE or SCSI support is enabled (CONFIG_CMD_IDE or
776 CONFIG_CMD_SCSI) you must configure support for at
777 least one partition type as well.
780 CONFIG_IDE_RESET_ROUTINE - this is defined in several
781 board configurations files but used nowhere!
783 CONFIG_IDE_RESET - is this is defined, IDE Reset will
784 be performed by calling the function
785 ide_set_reset(int reset)
786 which has to be defined in a board specific file
791 Set this to enable ATAPI support.
796 Set this to enable support for disks larger than 137GB
797 Also look at CONFIG_SYS_64BIT_LBA.
798 Whithout these , LBA48 support uses 32bit variables and will 'only'
799 support disks up to 2.1TB.
801 CONFIG_SYS_64BIT_LBA:
802 When enabled, makes the IDE subsystem use 64bit sector addresses.
806 At the moment only there is only support for the
807 SYM53C8XX SCSI controller; define
808 CONFIG_SCSI_SYM53C8XX to enable it.
810 CONFIG_SYS_SCSI_MAX_LUN [8], CONFIG_SYS_SCSI_MAX_SCSI_ID [7] and
811 CONFIG_SYS_SCSI_MAX_DEVICE [CONFIG_SYS_SCSI_MAX_SCSI_ID *
812 CONFIG_SYS_SCSI_MAX_LUN] can be adjusted to define the
813 maximum numbers of LUNs, SCSI ID's and target
815 CONFIG_SYS_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz)
817 - NETWORK Support (PCI):
819 Support for Intel 8254x gigabit chips.
821 CONFIG_E1000_FALLBACK_MAC
822 default MAC for empty EEPROM after production.
825 Support for Intel 82557/82559/82559ER chips.
826 Optional CONFIG_EEPRO100_SROM_WRITE enables EEPROM
827 write routine for first time initialisation.
830 Support for Digital 2114x chips.
831 Optional CONFIG_TULIP_SELECT_MEDIA for board specific
832 modem chip initialisation (KS8761/QS6611).
835 Support for National dp83815 chips.
838 Support for National dp8382[01] gigabit chips.
840 - NETWORK Support (other):
842 CONFIG_DRIVER_AT91EMAC
843 Support for AT91RM9200 EMAC.
846 Define this to use reduced MII inteface
848 CONFIG_DRIVER_AT91EMAC_QUIET
849 If this defined, the driver is quiet.
850 The driver doen't show link status messages.
852 CONFIG_DRIVER_LAN91C96
853 Support for SMSC's LAN91C96 chips.
856 Define this to hold the physical address
857 of the LAN91C96's I/O space
859 CONFIG_LAN91C96_USE_32_BIT
860 Define this to enable 32 bit addressing
862 CONFIG_DRIVER_SMC91111
863 Support for SMSC's LAN91C111 chip
866 Define this to hold the physical address
867 of the device (I/O space)
869 CONFIG_SMC_USE_32_BIT
870 Define this if data bus is 32 bits
872 CONFIG_SMC_USE_IOFUNCS
873 Define this to use i/o functions instead of macros
874 (some hardware wont work with macros)
877 Support for Faraday's FTGMAC100 Gigabit SoC Ethernet
879 CONFIG_FTGMAC100_EGIGA
880 Define this to use GE link update with gigabit PHY.
881 Define this if FTGMAC100 is connected to gigabit PHY.
882 If your system has 10/100 PHY only, it might not occur
883 wrong behavior. Because PHY usually return timeout or
884 useless data when polling gigabit status and gigabit
885 control registers. This behavior won't affect the
886 correctnessof 10/100 link speed update.
889 Support for SMSC's LAN911x and LAN921x chips
892 Define this to hold the physical address
893 of the device (I/O space)
895 CONFIG_SMC911X_32_BIT
896 Define this if data bus is 32 bits
898 CONFIG_SMC911X_16_BIT
899 Define this if data bus is 16 bits. If your processor
900 automatically converts one 32 bit word to two 16 bit
901 words you may also try CONFIG_SMC911X_32_BIT.
904 Support for Renesas on-chip Ethernet controller
906 CONFIG_SH_ETHER_USE_PORT
907 Define the number of ports to be used
909 CONFIG_SH_ETHER_PHY_ADDR
910 Define the ETH PHY's address
912 CONFIG_SH_ETHER_CACHE_WRITEBACK
913 If this option is set, the driver enables cache flush.
916 At the moment only the UHCI host controller is
917 supported (PIP405, MIP405, MPC5200); define
918 CONFIG_USB_UHCI to enable it.
919 define CONFIG_USB_KEYBOARD to enable the USB Keyboard
920 and define CONFIG_USB_STORAGE to enable the USB
923 Supported are USB Keyboards and USB Floppy drives
925 MPC5200 USB requires additional defines:
927 for 528 MHz Clock: 0x0001bbbb
931 for differential drivers: 0x00001000
932 for single ended drivers: 0x00005000
933 for differential drivers on PSC3: 0x00000100
934 for single ended drivers on PSC3: 0x00004100
935 CONFIG_SYS_USB_EVENT_POLL
936 May be defined to allow interrupt polling
937 instead of using asynchronous interrupts
940 Define the below if you wish to use the USB console.
941 Once firmware is rebuilt from a serial console issue the
942 command "setenv stdin usbtty; setenv stdout usbtty" and
943 attach your USB cable. The Unix command "dmesg" should print
944 it has found a new device. The environment variable usbtty
945 can be set to gserial or cdc_acm to enable your device to
946 appear to a USB host as a Linux gserial device or a
947 Common Device Class Abstract Control Model serial device.
948 If you select usbtty = gserial you should be able to enumerate
950 # modprobe usbserial vendor=0xVendorID product=0xProductID
951 else if using cdc_acm, simply setting the environment
952 variable usbtty to be cdc_acm should suffice. The following
953 might be defined in YourBoardName.h
956 Define this to build a UDC device
959 Define this to have a tty type of device available to
960 talk to the UDC device
962 CONFIG_SYS_CONSOLE_IS_IN_ENV
963 Define this if you want stdin, stdout &/or stderr to
967 CONFIG_SYS_USB_EXTC_CLK 0xBLAH
968 Derive USB clock from external clock "blah"
969 - CONFIG_SYS_USB_EXTC_CLK 0x02
971 CONFIG_SYS_USB_BRG_CLK 0xBLAH
972 Derive USB clock from brgclk
973 - CONFIG_SYS_USB_BRG_CLK 0x04
975 If you have a USB-IF assigned VendorID then you may wish to
976 define your own vendor specific values either in BoardName.h
977 or directly in usbd_vendor_info.h. If you don't define
978 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME,
979 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot
980 should pretend to be a Linux device to it's target host.
982 CONFIG_USBD_MANUFACTURER
983 Define this string as the name of your company for
984 - CONFIG_USBD_MANUFACTURER "my company"
986 CONFIG_USBD_PRODUCT_NAME
987 Define this string as the name of your product
988 - CONFIG_USBD_PRODUCT_NAME "acme usb device"
991 Define this as your assigned Vendor ID from the USB
992 Implementors Forum. This *must* be a genuine Vendor ID
993 to avoid polluting the USB namespace.
994 - CONFIG_USBD_VENDORID 0xFFFF
996 CONFIG_USBD_PRODUCTID
997 Define this as the unique Product ID
999 - CONFIG_USBD_PRODUCTID 0xFFFF
1003 The MMC controller on the Intel PXA is supported. To
1004 enable this define CONFIG_MMC. The MMC can be
1005 accessed from the boot prompt by mapping the device
1006 to physical memory similar to flash. Command line is
1007 enabled with CONFIG_CMD_MMC. The MMC driver also works with
1008 the FAT fs. This is enabled with CONFIG_CMD_FAT.
1010 - Journaling Flash filesystem support:
1011 CONFIG_JFFS2_NAND, CONFIG_JFFS2_NAND_OFF, CONFIG_JFFS2_NAND_SIZE,
1012 CONFIG_JFFS2_NAND_DEV
1013 Define these for a default partition on a NAND device
1015 CONFIG_SYS_JFFS2_FIRST_SECTOR,
1016 CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS
1017 Define these for a default partition on a NOR device
1019 CONFIG_SYS_JFFS_CUSTOM_PART
1020 Define this to create an own partition. You have to provide a
1021 function struct part_info* jffs2_part_info(int part_num)
1023 If you define only one JFFS2 partition you may also want to
1024 #define CONFIG_SYS_JFFS_SINGLE_PART 1
1025 to disable the command chpart. This is the default when you
1026 have not defined a custom partition
1031 Define this to enable standard (PC-Style) keyboard
1035 Standard PC keyboard driver with US (is default) and
1036 GERMAN key layout (switch via environment 'keymap=de') support.
1037 Export function i8042_kbd_init, i8042_tstc and i8042_getc
1038 for cfb_console. Supports cursor blinking.
1043 Define this to enable video support (for output to
1046 CONFIG_VIDEO_CT69000
1048 Enable Chips & Technologies 69000 Video chip
1050 CONFIG_VIDEO_SMI_LYNXEM
1051 Enable Silicon Motion SMI 712/710/810 Video chip. The
1052 video output is selected via environment 'videoout'
1053 (1 = LCD and 2 = CRT). If videoout is undefined, CRT is
1056 For the CT69000 and SMI_LYNXEM drivers, videomode is
1057 selected via environment 'videomode'. Two different ways
1059 - "videomode=num" 'num' is a standard LiLo mode numbers.
1060 Following standard modes are supported (* is default):
1062 Colors 640x480 800x600 1024x768 1152x864 1280x1024
1063 -------------+---------------------------------------------
1064 8 bits | 0x301* 0x303 0x305 0x161 0x307
1065 15 bits | 0x310 0x313 0x316 0x162 0x319
1066 16 bits | 0x311 0x314 0x317 0x163 0x31A
1067 24 bits | 0x312 0x315 0x318 ? 0x31B
1068 -------------+---------------------------------------------
1069 (i.e. setenv videomode 317; saveenv; reset;)
1071 - "videomode=bootargs" all the video parameters are parsed
1072 from the bootargs. (See drivers/video/videomodes.c)
1075 CONFIG_VIDEO_SED13806
1076 Enable Epson SED13806 driver. This driver supports 8bpp
1077 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP
1078 or CONFIG_VIDEO_SED13806_16BPP
1081 Enable the Freescale DIU video driver. Reference boards for
1082 SOCs that have a DIU should define this macro to enable DIU
1083 support, and should also define these other macros:
1089 CONFIG_VIDEO_SW_CURSOR
1090 CONFIG_VGA_AS_SINGLE_DEVICE
1092 CONFIG_VIDEO_BMP_LOGO
1094 The DIU driver will look for the 'monitor' environment variable,
1095 and if defined, enable the DIU as a console during boot. This
1096 variable should be set to one of these values:
1098 '0' Output video to the DVI connector
1099 '1' Output video to the LVDS connector
1100 '2' Output video to the Dual-Link LVDS connector
1105 Define this to enable a custom keyboard support.
1106 This simply calls drv_keyboard_init() which must be
1107 defined in your board-specific files.
1108 The only board using this so far is RBC823.
1110 - LCD Support: CONFIG_LCD
1112 Define this to enable LCD support (for output to LCD
1113 display); also select one of the supported displays
1114 by defining one of these:
1118 HITACHI TX09D70VM1CCA, 3.5", 240x320.
1120 CONFIG_NEC_NL6448AC33:
1122 NEC NL6448AC33-18. Active, color, single scan.
1124 CONFIG_NEC_NL6448BC20
1126 NEC NL6448BC20-08. 6.5", 640x480.
1127 Active, color, single scan.
1129 CONFIG_NEC_NL6448BC33_54
1131 NEC NL6448BC33-54. 10.4", 640x480.
1132 Active, color, single scan.
1136 Sharp 320x240. Active, color, single scan.
1137 It isn't 16x9, and I am not sure what it is.
1139 CONFIG_SHARP_LQ64D341
1141 Sharp LQ64D341 display, 640x480.
1142 Active, color, single scan.
1146 HLD1045 display, 640x480.
1147 Active, color, single scan.
1151 Optrex CBL50840-2 NF-FW 99 22 M5
1153 Hitachi LMG6912RPFC-00T
1157 320x240. Black & white.
1159 Normally display is black on white background; define
1160 CONFIG_SYS_WHITE_ON_BLACK to get it inverted.
1162 - Splash Screen Support: CONFIG_SPLASH_SCREEN
1164 If this option is set, the environment is checked for
1165 a variable "splashimage". If found, the usual display
1166 of logo, copyright and system information on the LCD
1167 is suppressed and the BMP image at the address
1168 specified in "splashimage" is loaded instead. The
1169 console is redirected to the "nulldev", too. This
1170 allows for a "silent" boot where a splash screen is
1171 loaded very quickly after power-on.
1173 CONFIG_SPLASH_SCREEN_ALIGN
1175 If this option is set the splash image can be freely positioned
1176 on the screen. Environment variable "splashpos" specifies the
1177 position as "x,y". If a positive number is given it is used as
1178 number of pixel from left/top. If a negative number is given it
1179 is used as number of pixel from right/bottom. You can also
1180 specify 'm' for centering the image.
1183 setenv splashpos m,m
1184 => image at center of screen
1186 setenv splashpos 30,20
1187 => image at x = 30 and y = 20
1189 setenv splashpos -10,m
1190 => vertically centered image
1191 at x = dspWidth - bmpWidth - 9
1193 - Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP
1195 If this option is set, additionally to standard BMP
1196 images, gzipped BMP images can be displayed via the
1197 splashscreen support or the bmp command.
1199 - Run length encoded BMP image (RLE8) support: CONFIG_VIDEO_BMP_RLE8
1201 If this option is set, 8-bit RLE compressed BMP images
1202 can be displayed via the splashscreen support or the
1205 - Compression support:
1208 If this option is set, support for bzip2 compressed
1209 images is included. If not, only uncompressed and gzip
1210 compressed images are supported.
1212 NOTE: the bzip2 algorithm requires a lot of RAM, so
1213 the malloc area (as defined by CONFIG_SYS_MALLOC_LEN) should
1218 If this option is set, support for lzma compressed
1221 Note: The LZMA algorithm adds between 2 and 4KB of code and it
1222 requires an amount of dynamic memory that is given by the
1225 (1846 + 768 << (lc + lp)) * sizeof(uint16)
1227 Where lc and lp stand for, respectively, Literal context bits
1228 and Literal pos bits.
1230 This value is upper-bounded by 14MB in the worst case. Anyway,
1231 for a ~4MB large kernel image, we have lc=3 and lp=0 for a
1232 total amount of (1846 + 768 << (3 + 0)) * 2 = ~41KB... that is
1233 a very small buffer.
1235 Use the lzmainfo tool to determinate the lc and lp values and
1236 then calculate the amount of needed dynamic memory (ensuring
1237 the appropriate CONFIG_SYS_MALLOC_LEN value).
1242 The address of PHY on MII bus.
1244 CONFIG_PHY_CLOCK_FREQ (ppc4xx)
1246 The clock frequency of the MII bus
1250 If this option is set, support for speed/duplex
1251 detection of gigabit PHY is included.
1253 CONFIG_PHY_RESET_DELAY
1255 Some PHY like Intel LXT971A need extra delay after
1256 reset before any MII register access is possible.
1257 For such PHY, set this option to the usec delay
1258 required. (minimum 300usec for LXT971A)
1260 CONFIG_PHY_CMD_DELAY (ppc4xx)
1262 Some PHY like Intel LXT971A need extra delay after
1263 command issued before MII status register can be read
1273 Define a default value for Ethernet address to use
1274 for the respective Ethernet interface, in case this
1275 is not determined automatically.
1280 Define a default value for the IP address to use for
1281 the default Ethernet interface, in case this is not
1282 determined through e.g. bootp.
1284 - Server IP address:
1287 Defines a default value for the IP address of a TFTP
1288 server to contact when using the "tftboot" command.
1290 CONFIG_KEEP_SERVERADDR
1292 Keeps the server's MAC address, in the env 'serveraddr'
1293 for passing to bootargs (like Linux's netconsole option)
1295 - Multicast TFTP Mode:
1298 Defines whether you want to support multicast TFTP as per
1299 rfc-2090; for example to work with atftp. Lets lots of targets
1300 tftp down the same boot image concurrently. Note: the Ethernet
1301 driver in use must provide a function: mcast() to join/leave a
1304 CONFIG_BOOTP_RANDOM_DELAY
1305 - BOOTP Recovery Mode:
1306 CONFIG_BOOTP_RANDOM_DELAY
1308 If you have many targets in a network that try to
1309 boot using BOOTP, you may want to avoid that all
1310 systems send out BOOTP requests at precisely the same
1311 moment (which would happen for instance at recovery
1312 from a power failure, when all systems will try to
1313 boot, thus flooding the BOOTP server. Defining
1314 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
1315 inserted before sending out BOOTP requests. The
1316 following delays are inserted then:
1318 1st BOOTP request: delay 0 ... 1 sec
1319 2nd BOOTP request: delay 0 ... 2 sec
1320 3rd BOOTP request: delay 0 ... 4 sec
1322 BOOTP requests: delay 0 ... 8 sec
1324 - DHCP Advanced Options:
1325 You can fine tune the DHCP functionality by defining
1326 CONFIG_BOOTP_* symbols:
1328 CONFIG_BOOTP_SUBNETMASK
1329 CONFIG_BOOTP_GATEWAY
1330 CONFIG_BOOTP_HOSTNAME
1331 CONFIG_BOOTP_NISDOMAIN
1332 CONFIG_BOOTP_BOOTPATH
1333 CONFIG_BOOTP_BOOTFILESIZE
1336 CONFIG_BOOTP_SEND_HOSTNAME
1337 CONFIG_BOOTP_NTPSERVER
1338 CONFIG_BOOTP_TIMEOFFSET
1339 CONFIG_BOOTP_VENDOREX
1341 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip
1342 environment variable, not the BOOTP server.
1344 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS
1345 serverip from a DHCP server, it is possible that more
1346 than one DNS serverip is offered to the client.
1347 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS
1348 serverip will be stored in the additional environment
1349 variable "dnsip2". The first DNS serverip is always
1350 stored in the variable "dnsip", when CONFIG_BOOTP_DNS
1353 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable
1354 to do a dynamic update of a DNS server. To do this, they
1355 need the hostname of the DHCP requester.
1356 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content
1357 of the "hostname" environment variable is passed as
1358 option 12 to the DHCP server.
1360 CONFIG_BOOTP_DHCP_REQUEST_DELAY
1362 A 32bit value in microseconds for a delay between
1363 receiving a "DHCP Offer" and sending the "DHCP Request".
1364 This fixes a problem with certain DHCP servers that don't
1365 respond 100% of the time to a "DHCP request". E.g. On an
1366 AT91RM9200 processor running at 180MHz, this delay needed
1367 to be *at least* 15,000 usec before a Windows Server 2003
1368 DHCP server would reply 100% of the time. I recommend at
1369 least 50,000 usec to be safe. The alternative is to hope
1370 that one of the retries will be successful but note that
1371 the DHCP timeout and retry process takes a longer than
1375 CONFIG_CDP_DEVICE_ID
1377 The device id used in CDP trigger frames.
1379 CONFIG_CDP_DEVICE_ID_PREFIX
1381 A two character string which is prefixed to the MAC address
1386 A printf format string which contains the ascii name of
1387 the port. Normally is set to "eth%d" which sets
1388 eth0 for the first Ethernet, eth1 for the second etc.
1390 CONFIG_CDP_CAPABILITIES
1392 A 32bit integer which indicates the device capabilities;
1393 0x00000010 for a normal host which does not forwards.
1397 An ascii string containing the version of the software.
1401 An ascii string containing the name of the platform.
1405 A 32bit integer sent on the trigger.
1407 CONFIG_CDP_POWER_CONSUMPTION
1409 A 16bit integer containing the power consumption of the
1410 device in .1 of milliwatts.
1412 CONFIG_CDP_APPLIANCE_VLAN_TYPE
1414 A byte containing the id of the VLAN.
1416 - Status LED: CONFIG_STATUS_LED
1418 Several configurations allow to display the current
1419 status using a LED. For instance, the LED will blink
1420 fast while running U-Boot code, stop blinking as
1421 soon as a reply to a BOOTP request was received, and
1422 start blinking slow once the Linux kernel is running
1423 (supported by a status LED driver in the Linux
1424 kernel). Defining CONFIG_STATUS_LED enables this
1427 - CAN Support: CONFIG_CAN_DRIVER
1429 Defining CONFIG_CAN_DRIVER enables CAN driver support
1430 on those systems that support this (optional)
1431 feature, like the TQM8xxL modules.
1433 - I2C Support: CONFIG_HARD_I2C | CONFIG_SOFT_I2C
1435 These enable I2C serial bus commands. Defining either of
1436 (but not both of) CONFIG_HARD_I2C or CONFIG_SOFT_I2C will
1437 include the appropriate I2C driver for the selected CPU.
1439 This will allow you to use i2c commands at the u-boot
1440 command line (as long as you set CONFIG_CMD_I2C in
1441 CONFIG_COMMANDS) and communicate with i2c based realtime
1442 clock chips. See common/cmd_i2c.c for a description of the
1443 command line interface.
1445 CONFIG_HARD_I2C selects a hardware I2C controller.
1447 CONFIG_SOFT_I2C configures u-boot to use a software (aka
1448 bit-banging) driver instead of CPM or similar hardware
1451 There are several other quantities that must also be
1452 defined when you define CONFIG_HARD_I2C or CONFIG_SOFT_I2C.
1454 In both cases you will need to define CONFIG_SYS_I2C_SPEED
1455 to be the frequency (in Hz) at which you wish your i2c bus
1456 to run and CONFIG_SYS_I2C_SLAVE to be the address of this node (ie
1457 the CPU's i2c node address).
1459 Now, the u-boot i2c code for the mpc8xx
1460 (arch/powerpc/cpu/mpc8xx/i2c.c) sets the CPU up as a master node
1461 and so its address should therefore be cleared to 0 (See,
1462 eg, MPC823e User's Manual p.16-473). So, set
1463 CONFIG_SYS_I2C_SLAVE to 0.
1465 CONFIG_SYS_I2C_INIT_MPC5XXX
1467 When a board is reset during an i2c bus transfer
1468 chips might think that the current transfer is still
1469 in progress. Reset the slave devices by sending start
1470 commands until the slave device responds.
1472 That's all that's required for CONFIG_HARD_I2C.
1474 If you use the software i2c interface (CONFIG_SOFT_I2C)
1475 then the following macros need to be defined (examples are
1476 from include/configs/lwmon.h):
1480 (Optional). Any commands necessary to enable the I2C
1481 controller or configure ports.
1483 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
1487 (Only for MPC8260 CPU). The I/O port to use (the code
1488 assumes both bits are on the same port). Valid values
1489 are 0..3 for ports A..D.
1493 The code necessary to make the I2C data line active
1494 (driven). If the data line is open collector, this
1497 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
1501 The code necessary to make the I2C data line tri-stated
1502 (inactive). If the data line is open collector, this
1505 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
1509 Code that returns TRUE if the I2C data line is high,
1512 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
1516 If <bit> is TRUE, sets the I2C data line high. If it
1517 is FALSE, it clears it (low).
1519 eg: #define I2C_SDA(bit) \
1520 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
1521 else immr->im_cpm.cp_pbdat &= ~PB_SDA
1525 If <bit> is TRUE, sets the I2C clock line high. If it
1526 is FALSE, it clears it (low).
1528 eg: #define I2C_SCL(bit) \
1529 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
1530 else immr->im_cpm.cp_pbdat &= ~PB_SCL
1534 This delay is invoked four times per clock cycle so this
1535 controls the rate of data transfer. The data rate thus
1536 is 1 / (I2C_DELAY * 4). Often defined to be something
1539 #define I2C_DELAY udelay(2)
1541 CONFIG_SOFT_I2C_GPIO_SCL / CONFIG_SOFT_I2C_GPIO_SDA
1543 If your arch supports the generic GPIO framework (asm/gpio.h),
1544 then you may alternatively define the two GPIOs that are to be
1545 used as SCL / SDA. Any of the previous I2C_xxx macros will
1546 have GPIO-based defaults assigned to them as appropriate.
1548 You should define these to the GPIO value as given directly to
1549 the generic GPIO functions.
1551 CONFIG_SYS_I2C_INIT_BOARD
1553 When a board is reset during an i2c bus transfer
1554 chips might think that the current transfer is still
1555 in progress. On some boards it is possible to access
1556 the i2c SCLK line directly, either by using the
1557 processor pin as a GPIO or by having a second pin
1558 connected to the bus. If this option is defined a
1559 custom i2c_init_board() routine in boards/xxx/board.c
1560 is run early in the boot sequence.
1562 CONFIG_SYS_I2C_BOARD_LATE_INIT
1564 An alternative to CONFIG_SYS_I2C_INIT_BOARD. If this option is
1565 defined a custom i2c_board_late_init() routine in
1566 boards/xxx/board.c is run AFTER the operations in i2c_init()
1567 is completed. This callpoint can be used to unreset i2c bus
1568 using CPU i2c controller register accesses for CPUs whose i2c
1569 controller provide such a method. It is called at the end of
1570 i2c_init() to allow i2c_init operations to setup the i2c bus
1571 controller on the CPU (e.g. setting bus speed & slave address).
1573 CONFIG_I2CFAST (PPC405GP|PPC405EP only)
1575 This option enables configuration of bi_iic_fast[] flags
1576 in u-boot bd_info structure based on u-boot environment
1577 variable "i2cfast". (see also i2cfast)
1579 CONFIG_I2C_MULTI_BUS
1581 This option allows the use of multiple I2C buses, each of which
1582 must have a controller. At any point in time, only one bus is
1583 active. To switch to a different bus, use the 'i2c dev' command.
1584 Note that bus numbering is zero-based.
1586 CONFIG_SYS_I2C_NOPROBES
1588 This option specifies a list of I2C devices that will be skipped
1589 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS
1590 is set, specify a list of bus-device pairs. Otherwise, specify
1591 a 1D array of device addresses
1594 #undef CONFIG_I2C_MULTI_BUS
1595 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68}
1597 will skip addresses 0x50 and 0x68 on a board with one I2C bus
1599 #define CONFIG_I2C_MULTI_BUS
1600 #define CONFIG_SYS_I2C_MULTI_NOPROBES {{0,0x50},{0,0x68},{1,0x54}}
1602 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1
1604 CONFIG_SYS_SPD_BUS_NUM
1606 If defined, then this indicates the I2C bus number for DDR SPD.
1607 If not defined, then U-Boot assumes that SPD is on I2C bus 0.
1609 CONFIG_SYS_RTC_BUS_NUM
1611 If defined, then this indicates the I2C bus number for the RTC.
1612 If not defined, then U-Boot assumes that RTC is on I2C bus 0.
1614 CONFIG_SYS_DTT_BUS_NUM
1616 If defined, then this indicates the I2C bus number for the DTT.
1617 If not defined, then U-Boot assumes that DTT is on I2C bus 0.
1619 CONFIG_SYS_I2C_DTT_ADDR:
1621 If defined, specifies the I2C address of the DTT device.
1622 If not defined, then U-Boot uses predefined value for
1623 specified DTT device.
1627 Define this option if you want to use Freescale's I2C driver in
1628 drivers/i2c/fsl_i2c.c.
1632 Define this option if you have I2C devices reached over 1 .. n
1633 I2C Muxes like the pca9544a. This option addes a new I2C
1634 Command "i2c bus [muxtype:muxaddr:muxchannel]" which adds a
1635 new I2C Bus to the existing I2C Busses. If you select the
1636 new Bus with "i2c dev", u-bbot sends first the commandos for
1637 the muxes to activate this new "bus".
1639 CONFIG_I2C_MULTI_BUS must be also defined, to use this
1643 Adding a new I2C Bus reached over 2 pca9544a muxes
1644 The First mux with address 70 and channel 6
1645 The Second mux with address 71 and channel 4
1647 => i2c bus pca9544a:70:6:pca9544a:71:4
1649 Use the "i2c bus" command without parameter, to get a list
1650 of I2C Busses with muxes:
1653 Busses reached over muxes:
1655 reached over Mux(es):
1658 reached over Mux(es):
1663 If you now switch to the new I2C Bus 3 with "i2c dev 3"
1664 u-boot sends First the Commando to the mux@70 to enable
1665 channel 6, and then the Commando to the mux@71 to enable
1668 After that, you can use the "normal" i2c commands as
1669 usual, to communicate with your I2C devices behind
1672 This option is actually implemented for the bitbanging
1673 algorithm in common/soft_i2c.c and for the Hardware I2C
1674 Bus on the MPC8260. But it should be not so difficult
1675 to add this option to other architectures.
1677 CONFIG_SOFT_I2C_READ_REPEATED_START
1679 defining this will force the i2c_read() function in
1680 the soft_i2c driver to perform an I2C repeated start
1681 between writing the address pointer and reading the
1682 data. If this define is omitted the default behaviour
1683 of doing a stop-start sequence will be used. Most I2C
1684 devices can use either method, but some require one or
1687 - SPI Support: CONFIG_SPI
1689 Enables SPI driver (so far only tested with
1690 SPI EEPROM, also an instance works with Crystal A/D and
1691 D/As on the SACSng board)
1695 Enables the driver for SPI controller on SuperH. Currently
1696 only SH7757 is supported.
1700 Enables extended (16-bit) SPI EEPROM addressing.
1701 (symmetrical to CONFIG_I2C_X)
1705 Enables a software (bit-bang) SPI driver rather than
1706 using hardware support. This is a general purpose
1707 driver that only requires three general I/O port pins
1708 (two outputs, one input) to function. If this is
1709 defined, the board configuration must define several
1710 SPI configuration items (port pins to use, etc). For
1711 an example, see include/configs/sacsng.h.
1715 Enables a hardware SPI driver for general-purpose reads
1716 and writes. As with CONFIG_SOFT_SPI, the board configuration
1717 must define a list of chip-select function pointers.
1718 Currently supported on some MPC8xxx processors. For an
1719 example, see include/configs/mpc8349emds.h.
1723 Enables the driver for the SPI controllers on i.MX and MXC
1724 SoCs. Currently only i.MX31 is supported.
1726 - FPGA Support: CONFIG_FPGA
1728 Enables FPGA subsystem.
1730 CONFIG_FPGA_<vendor>
1732 Enables support for specific chip vendors.
1735 CONFIG_FPGA_<family>
1737 Enables support for FPGA family.
1738 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX)
1742 Specify the number of FPGA devices to support.
1744 CONFIG_SYS_FPGA_PROG_FEEDBACK
1746 Enable printing of hash marks during FPGA configuration.
1748 CONFIG_SYS_FPGA_CHECK_BUSY
1750 Enable checks on FPGA configuration interface busy
1751 status by the configuration function. This option
1752 will require a board or device specific function to
1757 If defined, a function that provides delays in the FPGA
1758 configuration driver.
1760 CONFIG_SYS_FPGA_CHECK_CTRLC
1761 Allow Control-C to interrupt FPGA configuration
1763 CONFIG_SYS_FPGA_CHECK_ERROR
1765 Check for configuration errors during FPGA bitfile
1766 loading. For example, abort during Virtex II
1767 configuration if the INIT_B line goes low (which
1768 indicated a CRC error).
1770 CONFIG_SYS_FPGA_WAIT_INIT
1772 Maximum time to wait for the INIT_B line to deassert
1773 after PROB_B has been deasserted during a Virtex II
1774 FPGA configuration sequence. The default time is 500
1777 CONFIG_SYS_FPGA_WAIT_BUSY
1779 Maximum time to wait for BUSY to deassert during
1780 Virtex II FPGA configuration. The default is 5 ms.
1782 CONFIG_SYS_FPGA_WAIT_CONFIG
1784 Time to wait after FPGA configuration. The default is
1787 - Configuration Management:
1790 If defined, this string will be added to the U-Boot
1791 version information (U_BOOT_VERSION)
1793 - Vendor Parameter Protection:
1795 U-Boot considers the values of the environment
1796 variables "serial#" (Board Serial Number) and
1797 "ethaddr" (Ethernet Address) to be parameters that
1798 are set once by the board vendor / manufacturer, and
1799 protects these variables from casual modification by
1800 the user. Once set, these variables are read-only,
1801 and write or delete attempts are rejected. You can
1802 change this behaviour:
1804 If CONFIG_ENV_OVERWRITE is #defined in your config
1805 file, the write protection for vendor parameters is
1806 completely disabled. Anybody can change or delete
1809 Alternatively, if you #define _both_ CONFIG_ETHADDR
1810 _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
1811 Ethernet address is installed in the environment,
1812 which can be changed exactly ONCE by the user. [The
1813 serial# is unaffected by this, i. e. it remains
1819 Define this variable to enable the reservation of
1820 "protected RAM", i. e. RAM which is not overwritten
1821 by U-Boot. Define CONFIG_PRAM to hold the number of
1822 kB you want to reserve for pRAM. You can overwrite
1823 this default value by defining an environment
1824 variable "pram" to the number of kB you want to
1825 reserve. Note that the board info structure will
1826 still show the full amount of RAM. If pRAM is
1827 reserved, a new environment variable "mem" will
1828 automatically be defined to hold the amount of
1829 remaining RAM in a form that can be passed as boot
1830 argument to Linux, for instance like that:
1832 setenv bootargs ... mem=\${mem}
1835 This way you can tell Linux not to use this memory,
1836 either, which results in a memory region that will
1837 not be affected by reboots.
1839 *WARNING* If your board configuration uses automatic
1840 detection of the RAM size, you must make sure that
1841 this memory test is non-destructive. So far, the
1842 following board configurations are known to be
1845 ETX094, IVMS8, IVML24, SPD8xx, TQM8xxL,
1846 HERMES, IP860, RPXlite, LWMON, LANTEC,
1852 Define this variable to stop the system in case of a
1853 fatal error, so that you have to reset it manually.
1854 This is probably NOT a good idea for an embedded
1855 system where you want the system to reboot
1856 automatically as fast as possible, but it may be
1857 useful during development since you can try to debug
1858 the conditions that lead to the situation.
1860 CONFIG_NET_RETRY_COUNT
1862 This variable defines the number of retries for
1863 network operations like ARP, RARP, TFTP, or BOOTP
1864 before giving up the operation. If not defined, a
1865 default value of 5 is used.
1869 Timeout waiting for an ARP reply in milliseconds.
1871 - Command Interpreter:
1872 CONFIG_AUTO_COMPLETE
1874 Enable auto completion of commands using TAB.
1876 Note that this feature has NOT been implemented yet
1877 for the "hush" shell.
1880 CONFIG_SYS_HUSH_PARSER
1882 Define this variable to enable the "hush" shell (from
1883 Busybox) as command line interpreter, thus enabling
1884 powerful command line syntax like
1885 if...then...else...fi conditionals or `&&' and '||'
1886 constructs ("shell scripts").
1888 If undefined, you get the old, much simpler behaviour
1889 with a somewhat smaller memory footprint.
1892 CONFIG_SYS_PROMPT_HUSH_PS2
1894 This defines the secondary prompt string, which is
1895 printed when the command interpreter needs more input
1896 to complete a command. Usually "> ".
1900 In the current implementation, the local variables
1901 space and global environment variables space are
1902 separated. Local variables are those you define by
1903 simply typing `name=value'. To access a local
1904 variable later on, you have write `$name' or
1905 `${name}'; to execute the contents of a variable
1906 directly type `$name' at the command prompt.
1908 Global environment variables are those you use
1909 setenv/printenv to work with. To run a command stored
1910 in such a variable, you need to use the run command,
1911 and you must not use the '$' sign to access them.
1913 To store commands and special characters in a
1914 variable, please use double quotation marks
1915 surrounding the whole text of the variable, instead
1916 of the backslashes before semicolons and special
1919 - Commandline Editing and History:
1920 CONFIG_CMDLINE_EDITING
1922 Enable editing and History functions for interactive
1923 commandline input operations
1925 - Default Environment:
1926 CONFIG_EXTRA_ENV_SETTINGS
1928 Define this to contain any number of null terminated
1929 strings (variable = value pairs) that will be part of
1930 the default environment compiled into the boot image.
1932 For example, place something like this in your
1933 board's config file:
1935 #define CONFIG_EXTRA_ENV_SETTINGS \
1939 Warning: This method is based on knowledge about the
1940 internal format how the environment is stored by the
1941 U-Boot code. This is NOT an official, exported
1942 interface! Although it is unlikely that this format
1943 will change soon, there is no guarantee either.
1944 You better know what you are doing here.
1946 Note: overly (ab)use of the default environment is
1947 discouraged. Make sure to check other ways to preset
1948 the environment like the "source" command or the
1951 - DataFlash Support:
1952 CONFIG_HAS_DATAFLASH
1954 Defining this option enables DataFlash features and
1955 allows to read/write in Dataflash via the standard
1958 - SystemACE Support:
1961 Adding this option adds support for Xilinx SystemACE
1962 chips attached via some sort of local bus. The address
1963 of the chip must also be defined in the
1964 CONFIG_SYS_SYSTEMACE_BASE macro. For example:
1966 #define CONFIG_SYSTEMACE
1967 #define CONFIG_SYS_SYSTEMACE_BASE 0xf0000000
1969 When SystemACE support is added, the "ace" device type
1970 becomes available to the fat commands, i.e. fatls.
1972 - TFTP Fixed UDP Port:
1975 If this is defined, the environment variable tftpsrcp
1976 is used to supply the TFTP UDP source port value.
1977 If tftpsrcp isn't defined, the normal pseudo-random port
1978 number generator is used.
1980 Also, the environment variable tftpdstp is used to supply
1981 the TFTP UDP destination port value. If tftpdstp isn't
1982 defined, the normal port 69 is used.
1984 The purpose for tftpsrcp is to allow a TFTP server to
1985 blindly start the TFTP transfer using the pre-configured
1986 target IP address and UDP port. This has the effect of
1987 "punching through" the (Windows XP) firewall, allowing
1988 the remainder of the TFTP transfer to proceed normally.
1989 A better solution is to properly configure the firewall,
1990 but sometimes that is not allowed.
1992 - Show boot progress:
1993 CONFIG_SHOW_BOOT_PROGRESS
1995 Defining this option allows to add some board-
1996 specific code (calling a user-provided function
1997 "show_boot_progress(int)") that enables you to show
1998 the system's boot progress on some display (for
1999 example, some LED's) on your board. At the moment,
2000 the following checkpoints are implemented:
2002 - Standalone program support:
2003 CONFIG_STANDALONE_LOAD_ADDR
2005 This option allows to define board specific values
2006 for the address where standalone program gets loaded,
2007 thus overwriting the architecutre dependent default
2010 Legacy uImage format:
2013 1 common/cmd_bootm.c before attempting to boot an image
2014 -1 common/cmd_bootm.c Image header has bad magic number
2015 2 common/cmd_bootm.c Image header has correct magic number
2016 -2 common/cmd_bootm.c Image header has bad checksum
2017 3 common/cmd_bootm.c Image header has correct checksum
2018 -3 common/cmd_bootm.c Image data has bad checksum
2019 4 common/cmd_bootm.c Image data has correct checksum
2020 -4 common/cmd_bootm.c Image is for unsupported architecture
2021 5 common/cmd_bootm.c Architecture check OK
2022 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi)
2023 6 common/cmd_bootm.c Image Type check OK
2024 -6 common/cmd_bootm.c gunzip uncompression error
2025 -7 common/cmd_bootm.c Unimplemented compression type
2026 7 common/cmd_bootm.c Uncompression OK
2027 8 common/cmd_bootm.c No uncompress/copy overwrite error
2028 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX)
2030 9 common/image.c Start initial ramdisk verification
2031 -10 common/image.c Ramdisk header has bad magic number
2032 -11 common/image.c Ramdisk header has bad checksum
2033 10 common/image.c Ramdisk header is OK
2034 -12 common/image.c Ramdisk data has bad checksum
2035 11 common/image.c Ramdisk data has correct checksum
2036 12 common/image.c Ramdisk verification complete, start loading
2037 -13 common/image.c Wrong Image Type (not PPC Linux ramdisk)
2038 13 common/image.c Start multifile image verification
2039 14 common/image.c No initial ramdisk, no multifile, continue.
2041 15 arch/<arch>/lib/bootm.c All preparation done, transferring control to OS
2043 -30 arch/powerpc/lib/board.c Fatal error, hang the system
2044 -31 post/post.c POST test failed, detected by post_output_backlog()
2045 -32 post/post.c POST test failed, detected by post_run_single()
2047 34 common/cmd_doc.c before loading a Image from a DOC device
2048 -35 common/cmd_doc.c Bad usage of "doc" command
2049 35 common/cmd_doc.c correct usage of "doc" command
2050 -36 common/cmd_doc.c No boot device
2051 36 common/cmd_doc.c correct boot device
2052 -37 common/cmd_doc.c Unknown Chip ID on boot device
2053 37 common/cmd_doc.c correct chip ID found, device available
2054 -38 common/cmd_doc.c Read Error on boot device
2055 38 common/cmd_doc.c reading Image header from DOC device OK
2056 -39 common/cmd_doc.c Image header has bad magic number
2057 39 common/cmd_doc.c Image header has correct magic number
2058 -40 common/cmd_doc.c Error reading Image from DOC device
2059 40 common/cmd_doc.c Image header has correct magic number
2060 41 common/cmd_ide.c before loading a Image from a IDE device
2061 -42 common/cmd_ide.c Bad usage of "ide" command
2062 42 common/cmd_ide.c correct usage of "ide" command
2063 -43 common/cmd_ide.c No boot device
2064 43 common/cmd_ide.c boot device found
2065 -44 common/cmd_ide.c Device not available
2066 44 common/cmd_ide.c Device available
2067 -45 common/cmd_ide.c wrong partition selected
2068 45 common/cmd_ide.c partition selected
2069 -46 common/cmd_ide.c Unknown partition table
2070 46 common/cmd_ide.c valid partition table found
2071 -47 common/cmd_ide.c Invalid partition type
2072 47 common/cmd_ide.c correct partition type
2073 -48 common/cmd_ide.c Error reading Image Header on boot device
2074 48 common/cmd_ide.c reading Image Header from IDE device OK
2075 -49 common/cmd_ide.c Image header has bad magic number
2076 49 common/cmd_ide.c Image header has correct magic number
2077 -50 common/cmd_ide.c Image header has bad checksum
2078 50 common/cmd_ide.c Image header has correct checksum
2079 -51 common/cmd_ide.c Error reading Image from IDE device
2080 51 common/cmd_ide.c reading Image from IDE device OK
2081 52 common/cmd_nand.c before loading a Image from a NAND device
2082 -53 common/cmd_nand.c Bad usage of "nand" command
2083 53 common/cmd_nand.c correct usage of "nand" command
2084 -54 common/cmd_nand.c No boot device
2085 54 common/cmd_nand.c boot device found
2086 -55 common/cmd_nand.c Unknown Chip ID on boot device
2087 55 common/cmd_nand.c correct chip ID found, device available
2088 -56 common/cmd_nand.c Error reading Image Header on boot device
2089 56 common/cmd_nand.c reading Image Header from NAND device OK
2090 -57 common/cmd_nand.c Image header has bad magic number
2091 57 common/cmd_nand.c Image header has correct magic number
2092 -58 common/cmd_nand.c Error reading Image from NAND device
2093 58 common/cmd_nand.c reading Image from NAND device OK
2095 -60 common/env_common.c Environment has a bad CRC, using default
2097 64 net/eth.c starting with Ethernet configuration.
2098 -64 net/eth.c no Ethernet found.
2099 65 net/eth.c Ethernet found.
2101 -80 common/cmd_net.c usage wrong
2102 80 common/cmd_net.c before calling NetLoop()
2103 -81 common/cmd_net.c some error in NetLoop() occurred
2104 81 common/cmd_net.c NetLoop() back without error
2105 -82 common/cmd_net.c size == 0 (File with size 0 loaded)
2106 82 common/cmd_net.c trying automatic boot
2107 83 common/cmd_net.c running "source" command
2108 -83 common/cmd_net.c some error in automatic boot or "source" command
2109 84 common/cmd_net.c end without errors
2114 100 common/cmd_bootm.c Kernel FIT Image has correct format
2115 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format
2116 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration
2117 -101 common/cmd_bootm.c Can't get configuration for kernel subimage
2118 102 common/cmd_bootm.c Kernel unit name specified
2119 -103 common/cmd_bootm.c Can't get kernel subimage node offset
2120 103 common/cmd_bootm.c Found configuration node
2121 104 common/cmd_bootm.c Got kernel subimage node offset
2122 -104 common/cmd_bootm.c Kernel subimage hash verification failed
2123 105 common/cmd_bootm.c Kernel subimage hash verification OK
2124 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture
2125 106 common/cmd_bootm.c Architecture check OK
2126 -106 common/cmd_bootm.c Kernel subimage has wrong type
2127 107 common/cmd_bootm.c Kernel subimage type OK
2128 -107 common/cmd_bootm.c Can't get kernel subimage data/size
2129 108 common/cmd_bootm.c Got kernel subimage data/size
2130 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT)
2131 -109 common/cmd_bootm.c Can't get kernel subimage type
2132 -110 common/cmd_bootm.c Can't get kernel subimage comp
2133 -111 common/cmd_bootm.c Can't get kernel subimage os
2134 -112 common/cmd_bootm.c Can't get kernel subimage load address
2135 -113 common/cmd_bootm.c Image uncompress/copy overwrite error
2137 120 common/image.c Start initial ramdisk verification
2138 -120 common/image.c Ramdisk FIT image has incorrect format
2139 121 common/image.c Ramdisk FIT image has correct format
2140 122 common/image.c No ramdisk subimage unit name, using configuration
2141 -122 common/image.c Can't get configuration for ramdisk subimage
2142 123 common/image.c Ramdisk unit name specified
2143 -124 common/image.c Can't get ramdisk subimage node offset
2144 125 common/image.c Got ramdisk subimage node offset
2145 -125 common/image.c Ramdisk subimage hash verification failed
2146 126 common/image.c Ramdisk subimage hash verification OK
2147 -126 common/image.c Ramdisk subimage for unsupported architecture
2148 127 common/image.c Architecture check OK
2149 -127 common/image.c Can't get ramdisk subimage data/size
2150 128 common/image.c Got ramdisk subimage data/size
2151 129 common/image.c Can't get ramdisk load address
2152 -129 common/image.c Got ramdisk load address
2154 -130 common/cmd_doc.c Incorrect FIT image format
2155 131 common/cmd_doc.c FIT image format OK
2157 -140 common/cmd_ide.c Incorrect FIT image format
2158 141 common/cmd_ide.c FIT image format OK
2160 -150 common/cmd_nand.c Incorrect FIT image format
2161 151 common/cmd_nand.c FIT image format OK
2163 - Automatic software updates via TFTP server
2165 CONFIG_UPDATE_TFTP_CNT_MAX
2166 CONFIG_UPDATE_TFTP_MSEC_MAX
2168 These options enable and control the auto-update feature;
2169 for a more detailed description refer to doc/README.update.
2171 - MTD Support (mtdparts command, UBI support)
2174 Adds the MTD device infrastructure from the Linux kernel.
2175 Needed for mtdparts command support.
2177 CONFIG_MTD_PARTITIONS
2179 Adds the MTD partitioning infrastructure from the Linux
2180 kernel. Needed for UBI support.
2186 [so far only for SMDK2400 and TRAB boards]
2188 - Modem support enable:
2189 CONFIG_MODEM_SUPPORT
2191 - RTS/CTS Flow control enable:
2194 - Modem debug support:
2195 CONFIG_MODEM_SUPPORT_DEBUG
2197 Enables debugging stuff (char screen[1024], dbg())
2198 for modem support. Useful only with BDI2000.
2200 - Interrupt support (PPC):
2202 There are common interrupt_init() and timer_interrupt()
2203 for all PPC archs. interrupt_init() calls interrupt_init_cpu()
2204 for CPU specific initialization. interrupt_init_cpu()
2205 should set decrementer_count to appropriate value. If
2206 CPU resets decrementer automatically after interrupt
2207 (ppc4xx) it should set decrementer_count to zero.
2208 timer_interrupt() calls timer_interrupt_cpu() for CPU
2209 specific handling. If board has watchdog / status_led
2210 / other_activity_monitor it works automatically from
2211 general timer_interrupt().
2215 In the target system modem support is enabled when a
2216 specific key (key combination) is pressed during
2217 power-on. Otherwise U-Boot will boot normally
2218 (autoboot). The key_pressed() function is called from
2219 board_init(). Currently key_pressed() is a dummy
2220 function, returning 1 and thus enabling modem
2223 If there are no modem init strings in the
2224 environment, U-Boot proceed to autoboot; the
2225 previous output (banner, info printfs) will be
2228 See also: doc/README.Modem
2231 Configuration Settings:
2232 -----------------------
2234 - CONFIG_SYS_LONGHELP: Defined when you want long help messages included;
2235 undefine this when you're short of memory.
2237 - CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default
2238 width of the commands listed in the 'help' command output.
2240 - CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to
2241 prompt for user input.
2243 - CONFIG_SYS_CBSIZE: Buffer size for input from the Console
2245 - CONFIG_SYS_PBSIZE: Buffer size for Console output
2247 - CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands
2249 - CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to
2250 the application (usually a Linux kernel) when it is
2253 - CONFIG_SYS_BAUDRATE_TABLE:
2254 List of legal baudrate settings for this board.
2256 - CONFIG_SYS_CONSOLE_INFO_QUIET
2257 Suppress display of console information at boot.
2259 - CONFIG_SYS_CONSOLE_IS_IN_ENV
2260 If the board specific function
2261 extern int overwrite_console (void);
2262 returns 1, the stdin, stderr and stdout are switched to the
2263 serial port, else the settings in the environment are used.
2265 - CONFIG_SYS_CONSOLE_OVERWRITE_ROUTINE
2266 Enable the call to overwrite_console().
2268 - CONFIG_SYS_CONSOLE_ENV_OVERWRITE
2269 Enable overwrite of previous console environment settings.
2271 - CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END:
2272 Begin and End addresses of the area used by the
2275 - CONFIG_SYS_ALT_MEMTEST:
2276 Enable an alternate, more extensive memory test.
2278 - CONFIG_SYS_MEMTEST_SCRATCH:
2279 Scratch address used by the alternate memory test
2280 You only need to set this if address zero isn't writeable
2282 - CONFIG_SYS_MEM_TOP_HIDE (PPC only):
2283 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header,
2284 this specified memory area will get subtracted from the top
2285 (end) of RAM and won't get "touched" at all by U-Boot. By
2286 fixing up gd->ram_size the Linux kernel should gets passed
2287 the now "corrected" memory size and won't touch it either.
2288 This should work for arch/ppc and arch/powerpc. Only Linux
2289 board ports in arch/powerpc with bootwrapper support that
2290 recalculate the memory size from the SDRAM controller setup
2291 will have to get fixed in Linux additionally.
2293 This option can be used as a workaround for the 440EPx/GRx
2294 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't
2297 WARNING: Please make sure that this value is a multiple of
2298 the Linux page size (normally 4k). If this is not the case,
2299 then the end address of the Linux memory will be located at a
2300 non page size aligned address and this could cause major
2303 - CONFIG_SYS_TFTP_LOADADDR:
2304 Default load address for network file downloads
2306 - CONFIG_SYS_LOADS_BAUD_CHANGE:
2307 Enable temporary baudrate change while serial download
2309 - CONFIG_SYS_SDRAM_BASE:
2310 Physical start address of SDRAM. _Must_ be 0 here.
2312 - CONFIG_SYS_MBIO_BASE:
2313 Physical start address of Motherboard I/O (if using a
2316 - CONFIG_SYS_FLASH_BASE:
2317 Physical start address of Flash memory.
2319 - CONFIG_SYS_MONITOR_BASE:
2320 Physical start address of boot monitor code (set by
2321 make config files to be same as the text base address
2322 (CONFIG_SYS_TEXT_BASE) used when linking) - same as
2323 CONFIG_SYS_FLASH_BASE when booting from flash.
2325 - CONFIG_SYS_MONITOR_LEN:
2326 Size of memory reserved for monitor code, used to
2327 determine _at_compile_time_ (!) if the environment is
2328 embedded within the U-Boot image, or in a separate
2331 - CONFIG_SYS_MALLOC_LEN:
2332 Size of DRAM reserved for malloc() use.
2334 - CONFIG_SYS_BOOTM_LEN:
2335 Normally compressed uImages are limited to an
2336 uncompressed size of 8 MBytes. If this is not enough,
2337 you can define CONFIG_SYS_BOOTM_LEN in your board config file
2338 to adjust this setting to your needs.
2340 - CONFIG_SYS_BOOTMAPSZ:
2341 Maximum size of memory mapped by the startup code of
2342 the Linux kernel; all data that must be processed by
2343 the Linux kernel (bd_info, boot arguments, FDT blob if
2344 used) must be put below this limit, unless "bootm_low"
2345 enviroment variable is defined and non-zero. In such case
2346 all data for the Linux kernel must be between "bootm_low"
2347 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ.
2349 - CONFIG_SYS_BOOT_RAMDISK_HIGH:
2350 Enable initrd_high functionality. If defined then the
2351 initrd_high feature is enabled and the bootm ramdisk subcommand
2354 - CONFIG_SYS_BOOT_GET_CMDLINE:
2355 Enables allocating and saving kernel cmdline in space between
2356 "bootm_low" and "bootm_low" + BOOTMAPSZ.
2358 - CONFIG_SYS_BOOT_GET_KBD:
2359 Enables allocating and saving a kernel copy of the bd_info in
2360 space between "bootm_low" and "bootm_low" + BOOTMAPSZ.
2362 - CONFIG_SYS_MAX_FLASH_BANKS:
2363 Max number of Flash memory banks
2365 - CONFIG_SYS_MAX_FLASH_SECT:
2366 Max number of sectors on a Flash chip
2368 - CONFIG_SYS_FLASH_ERASE_TOUT:
2369 Timeout for Flash erase operations (in ms)
2371 - CONFIG_SYS_FLASH_WRITE_TOUT:
2372 Timeout for Flash write operations (in ms)
2374 - CONFIG_SYS_FLASH_LOCK_TOUT
2375 Timeout for Flash set sector lock bit operation (in ms)
2377 - CONFIG_SYS_FLASH_UNLOCK_TOUT
2378 Timeout for Flash clear lock bits operation (in ms)
2380 - CONFIG_SYS_FLASH_PROTECTION
2381 If defined, hardware flash sectors protection is used
2382 instead of U-Boot software protection.
2384 - CONFIG_SYS_DIRECT_FLASH_TFTP:
2386 Enable TFTP transfers directly to flash memory;
2387 without this option such a download has to be
2388 performed in two steps: (1) download to RAM, and (2)
2389 copy from RAM to flash.
2391 The two-step approach is usually more reliable, since
2392 you can check if the download worked before you erase
2393 the flash, but in some situations (when system RAM is
2394 too limited to allow for a temporary copy of the
2395 downloaded image) this option may be very useful.
2397 - CONFIG_SYS_FLASH_CFI:
2398 Define if the flash driver uses extra elements in the
2399 common flash structure for storing flash geometry.
2401 - CONFIG_FLASH_CFI_DRIVER
2402 This option also enables the building of the cfi_flash driver
2403 in the drivers directory
2405 - CONFIG_FLASH_CFI_MTD
2406 This option enables the building of the cfi_mtd driver
2407 in the drivers directory. The driver exports CFI flash
2410 - CONFIG_SYS_FLASH_USE_BUFFER_WRITE
2411 Use buffered writes to flash.
2413 - CONFIG_FLASH_SPANSION_S29WS_N
2414 s29ws-n MirrorBit flash has non-standard addresses for buffered
2417 - CONFIG_SYS_FLASH_QUIET_TEST
2418 If this option is defined, the common CFI flash doesn't
2419 print it's warning upon not recognized FLASH banks. This
2420 is useful, if some of the configured banks are only
2421 optionally available.
2423 - CONFIG_FLASH_SHOW_PROGRESS
2424 If defined (must be an integer), print out countdown
2425 digits and dots. Recommended value: 45 (9..1) for 80
2426 column displays, 15 (3..1) for 40 column displays.
2428 - CONFIG_SYS_RX_ETH_BUFFER:
2429 Defines the number of Ethernet receive buffers. On some
2430 Ethernet controllers it is recommended to set this value
2431 to 8 or even higher (EEPRO100 or 405 EMAC), since all
2432 buffers can be full shortly after enabling the interface
2433 on high Ethernet traffic.
2434 Defaults to 4 if not defined.
2436 - CONFIG_ENV_MAX_ENTRIES
2438 Maximum number of entries in the hash table that is used
2439 internally to store the environment settings. The default
2440 setting is supposed to be generous and should work in most
2441 cases. This setting can be used to tune behaviour; see
2442 lib/hashtable.c for details.
2444 The following definitions that deal with the placement and management
2445 of environment data (variable area); in general, we support the
2446 following configurations:
2448 - CONFIG_ENV_IS_IN_FLASH:
2450 Define this if the environment is in flash memory.
2452 a) The environment occupies one whole flash sector, which is
2453 "embedded" in the text segment with the U-Boot code. This
2454 happens usually with "bottom boot sector" or "top boot
2455 sector" type flash chips, which have several smaller
2456 sectors at the start or the end. For instance, such a
2457 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In
2458 such a case you would place the environment in one of the
2459 4 kB sectors - with U-Boot code before and after it. With
2460 "top boot sector" type flash chips, you would put the
2461 environment in one of the last sectors, leaving a gap
2462 between U-Boot and the environment.
2464 - CONFIG_ENV_OFFSET:
2466 Offset of environment data (variable area) to the
2467 beginning of flash memory; for instance, with bottom boot
2468 type flash chips the second sector can be used: the offset
2469 for this sector is given here.
2471 CONFIG_ENV_OFFSET is used relative to CONFIG_SYS_FLASH_BASE.
2475 This is just another way to specify the start address of
2476 the flash sector containing the environment (instead of
2479 - CONFIG_ENV_SECT_SIZE:
2481 Size of the sector containing the environment.
2484 b) Sometimes flash chips have few, equal sized, BIG sectors.
2485 In such a case you don't want to spend a whole sector for
2490 If you use this in combination with CONFIG_ENV_IS_IN_FLASH
2491 and CONFIG_ENV_SECT_SIZE, you can specify to use only a part
2492 of this flash sector for the environment. This saves
2493 memory for the RAM copy of the environment.
2495 It may also save flash memory if you decide to use this
2496 when your environment is "embedded" within U-Boot code,
2497 since then the remainder of the flash sector could be used
2498 for U-Boot code. It should be pointed out that this is
2499 STRONGLY DISCOURAGED from a robustness point of view:
2500 updating the environment in flash makes it always
2501 necessary to erase the WHOLE sector. If something goes
2502 wrong before the contents has been restored from a copy in
2503 RAM, your target system will be dead.
2505 - CONFIG_ENV_ADDR_REDUND
2506 CONFIG_ENV_SIZE_REDUND
2508 These settings describe a second storage area used to hold
2509 a redundant copy of the environment data, so that there is
2510 a valid backup copy in case there is a power failure during
2511 a "saveenv" operation.
2513 BE CAREFUL! Any changes to the flash layout, and some changes to the
2514 source code will make it necessary to adapt <board>/u-boot.lds*
2518 - CONFIG_ENV_IS_IN_NVRAM:
2520 Define this if you have some non-volatile memory device
2521 (NVRAM, battery buffered SRAM) which you want to use for the
2527 These two #defines are used to determine the memory area you
2528 want to use for environment. It is assumed that this memory
2529 can just be read and written to, without any special
2532 BE CAREFUL! The first access to the environment happens quite early
2533 in U-Boot initalization (when we try to get the setting of for the
2534 console baudrate). You *MUST* have mapped your NVRAM area then, or
2537 Please note that even with NVRAM we still use a copy of the
2538 environment in RAM: we could work on NVRAM directly, but we want to
2539 keep settings there always unmodified except somebody uses "saveenv"
2540 to save the current settings.
2543 - CONFIG_ENV_IS_IN_EEPROM:
2545 Use this if you have an EEPROM or similar serial access
2546 device and a driver for it.
2548 - CONFIG_ENV_OFFSET:
2551 These two #defines specify the offset and size of the
2552 environment area within the total memory of your EEPROM.
2554 - CONFIG_SYS_I2C_EEPROM_ADDR:
2555 If defined, specified the chip address of the EEPROM device.
2556 The default address is zero.
2558 - CONFIG_SYS_EEPROM_PAGE_WRITE_BITS:
2559 If defined, the number of bits used to address bytes in a
2560 single page in the EEPROM device. A 64 byte page, for example
2561 would require six bits.
2563 - CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS:
2564 If defined, the number of milliseconds to delay between
2565 page writes. The default is zero milliseconds.
2567 - CONFIG_SYS_I2C_EEPROM_ADDR_LEN:
2568 The length in bytes of the EEPROM memory array address. Note
2569 that this is NOT the chip address length!
2571 - CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW:
2572 EEPROM chips that implement "address overflow" are ones
2573 like Catalyst 24WC04/08/16 which has 9/10/11 bits of
2574 address and the extra bits end up in the "chip address" bit
2575 slots. This makes a 24WC08 (1Kbyte) chip look like four 256
2578 Note that we consider the length of the address field to
2579 still be one byte because the extra address bits are hidden
2580 in the chip address.
2582 - CONFIG_SYS_EEPROM_SIZE:
2583 The size in bytes of the EEPROM device.
2585 - CONFIG_ENV_EEPROM_IS_ON_I2C
2586 define this, if you have I2C and SPI activated, and your
2587 EEPROM, which holds the environment, is on the I2C bus.
2589 - CONFIG_I2C_ENV_EEPROM_BUS
2590 if you have an Environment on an EEPROM reached over
2591 I2C muxes, you can define here, how to reach this
2592 EEPROM. For example:
2594 #define CONFIG_I2C_ENV_EEPROM_BUS "pca9547:70:d\0"
2596 EEPROM which holds the environment, is reached over
2597 a pca9547 i2c mux with address 0x70, channel 3.
2599 - CONFIG_ENV_IS_IN_DATAFLASH:
2601 Define this if you have a DataFlash memory device which you
2602 want to use for the environment.
2604 - CONFIG_ENV_OFFSET:
2608 These three #defines specify the offset and size of the
2609 environment area within the total memory of your DataFlash placed
2610 at the specified address.
2612 - CONFIG_ENV_IS_IN_NAND:
2614 Define this if you have a NAND device which you want to use
2615 for the environment.
2617 - CONFIG_ENV_OFFSET:
2620 These two #defines specify the offset and size of the environment
2621 area within the first NAND device. CONFIG_ENV_OFFSET must be
2622 aligned to an erase block boundary.
2624 - CONFIG_ENV_OFFSET_REDUND (optional):
2626 This setting describes a second storage area of CONFIG_ENV_SIZE
2627 size used to hold a redundant copy of the environment data, so
2628 that there is a valid backup copy in case there is a power failure
2629 during a "saveenv" operation. CONFIG_ENV_OFFSET_RENDUND must be
2630 aligned to an erase block boundary.
2632 - CONFIG_ENV_RANGE (optional):
2634 Specifies the length of the region in which the environment
2635 can be written. This should be a multiple of the NAND device's
2636 block size. Specifying a range with more erase blocks than
2637 are needed to hold CONFIG_ENV_SIZE allows bad blocks within
2638 the range to be avoided.
2640 - CONFIG_ENV_OFFSET_OOB (optional):
2642 Enables support for dynamically retrieving the offset of the
2643 environment from block zero's out-of-band data. The
2644 "nand env.oob" command can be used to record this offset.
2645 Currently, CONFIG_ENV_OFFSET_REDUND is not supported when
2646 using CONFIG_ENV_OFFSET_OOB.
2648 - CONFIG_NAND_ENV_DST
2650 Defines address in RAM to which the nand_spl code should copy the
2651 environment. If redundant environment is used, it will be copied to
2652 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE.
2654 - CONFIG_SYS_SPI_INIT_OFFSET
2656 Defines offset to the initial SPI buffer area in DPRAM. The
2657 area is used at an early stage (ROM part) if the environment
2658 is configured to reside in the SPI EEPROM: We need a 520 byte
2659 scratch DPRAM area. It is used between the two initialization
2660 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems
2661 to be a good choice since it makes it far enough from the
2662 start of the data area as well as from the stack pointer.
2664 Please note that the environment is read-only until the monitor
2665 has been relocated to RAM and a RAM copy of the environment has been
2666 created; also, when using EEPROM you will have to use getenv_f()
2667 until then to read environment variables.
2669 The environment is protected by a CRC32 checksum. Before the monitor
2670 is relocated into RAM, as a result of a bad CRC you will be working
2671 with the compiled-in default environment - *silently*!!! [This is
2672 necessary, because the first environment variable we need is the
2673 "baudrate" setting for the console - if we have a bad CRC, we don't
2674 have any device yet where we could complain.]
2676 Note: once the monitor has been relocated, then it will complain if
2677 the default environment is used; a new CRC is computed as soon as you
2678 use the "saveenv" command to store a valid environment.
2680 - CONFIG_SYS_FAULT_ECHO_LINK_DOWN:
2681 Echo the inverted Ethernet link state to the fault LED.
2683 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR
2684 also needs to be defined.
2686 - CONFIG_SYS_FAULT_MII_ADDR:
2687 MII address of the PHY to check for the Ethernet link state.
2689 - CONFIG_NS16550_MIN_FUNCTIONS:
2690 Define this if you desire to only have use of the NS16550_init
2691 and NS16550_putc functions for the serial driver located at
2692 drivers/serial/ns16550.c. This option is useful for saving
2693 space for already greatly restricted images, including but not
2694 limited to NAND_SPL configurations.
2696 Low Level (hardware related) configuration options:
2697 ---------------------------------------------------
2699 - CONFIG_SYS_CACHELINE_SIZE:
2700 Cache Line Size of the CPU.
2702 - CONFIG_SYS_DEFAULT_IMMR:
2703 Default address of the IMMR after system reset.
2705 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU,
2706 and RPXsuper) to be able to adjust the position of
2707 the IMMR register after a reset.
2709 - Floppy Disk Support:
2710 CONFIG_SYS_FDC_DRIVE_NUMBER
2712 the default drive number (default value 0)
2714 CONFIG_SYS_ISA_IO_STRIDE
2716 defines the spacing between FDC chipset registers
2719 CONFIG_SYS_ISA_IO_OFFSET
2721 defines the offset of register from address. It
2722 depends on which part of the data bus is connected to
2723 the FDC chipset. (default value 0)
2725 If CONFIG_SYS_ISA_IO_STRIDE CONFIG_SYS_ISA_IO_OFFSET and
2726 CONFIG_SYS_FDC_DRIVE_NUMBER are undefined, they take their
2729 if CONFIG_SYS_FDC_HW_INIT is defined, then the function
2730 fdc_hw_init() is called at the beginning of the FDC
2731 setup. fdc_hw_init() must be provided by the board
2732 source code. It is used to make hardware dependant
2735 - CONFIG_SYS_IMMR: Physical address of the Internal Memory.
2736 DO NOT CHANGE unless you know exactly what you're
2737 doing! (11-4) [MPC8xx/82xx systems only]
2739 - CONFIG_SYS_INIT_RAM_ADDR:
2741 Start address of memory area that can be used for
2742 initial data and stack; please note that this must be
2743 writable memory that is working WITHOUT special
2744 initialization, i. e. you CANNOT use normal RAM which
2745 will become available only after programming the
2746 memory controller and running certain initialization
2749 U-Boot uses the following memory types:
2750 - MPC8xx and MPC8260: IMMR (internal memory of the CPU)
2751 - MPC824X: data cache
2752 - PPC4xx: data cache
2754 - CONFIG_SYS_GBL_DATA_OFFSET:
2756 Offset of the initial data structure in the memory
2757 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually
2758 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial
2759 data is located at the end of the available space
2760 (sometimes written as (CONFIG_SYS_INIT_RAM_SIZE -
2761 CONFIG_SYS_INIT_DATA_SIZE), and the initial stack is just
2762 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR +
2763 CONFIG_SYS_GBL_DATA_OFFSET) downward.
2766 On the MPC824X (or other systems that use the data
2767 cache for initial memory) the address chosen for
2768 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must
2769 point to an otherwise UNUSED address space between
2770 the top of RAM and the start of the PCI space.
2772 - CONFIG_SYS_SIUMCR: SIU Module Configuration (11-6)
2774 - CONFIG_SYS_SYPCR: System Protection Control (11-9)
2776 - CONFIG_SYS_TBSCR: Time Base Status and Control (11-26)
2778 - CONFIG_SYS_PISCR: Periodic Interrupt Status and Control (11-31)
2780 - CONFIG_SYS_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30)
2782 - CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27)
2784 - CONFIG_SYS_OR_TIMING_SDRAM:
2787 - CONFIG_SYS_MAMR_PTA:
2788 periodic timer for refresh
2790 - CONFIG_SYS_DER: Debug Event Register (37-47)
2792 - FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM,
2793 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP,
2794 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM,
2795 CONFIG_SYS_BR1_PRELIM:
2796 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
2798 - SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
2799 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM,
2800 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM:
2801 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
2803 - CONFIG_SYS_MAMR_PTA, CONFIG_SYS_MPTPR_2BK_4K, CONFIG_SYS_MPTPR_1BK_4K, CONFIG_SYS_MPTPR_2BK_8K,
2804 CONFIG_SYS_MPTPR_1BK_8K, CONFIG_SYS_MAMR_8COL, CONFIG_SYS_MAMR_9COL:
2805 Machine Mode Register and Memory Periodic Timer
2806 Prescaler definitions (SDRAM timing)
2808 - CONFIG_SYS_I2C_UCODE_PATCH, CONFIG_SYS_I2C_DPMEM_OFFSET [0x1FC0]:
2809 enable I2C microcode relocation patch (MPC8xx);
2810 define relocation offset in DPRAM [DSP2]
2812 - CONFIG_SYS_SMC_UCODE_PATCH, CONFIG_SYS_SMC_DPMEM_OFFSET [0x1FC0]:
2813 enable SMC microcode relocation patch (MPC8xx);
2814 define relocation offset in DPRAM [SMC1]
2816 - CONFIG_SYS_SPI_UCODE_PATCH, CONFIG_SYS_SPI_DPMEM_OFFSET [0x1FC0]:
2817 enable SPI microcode relocation patch (MPC8xx);
2818 define relocation offset in DPRAM [SCC4]
2820 - CONFIG_SYS_USE_OSCCLK:
2821 Use OSCM clock mode on MBX8xx board. Be careful,
2822 wrong setting might damage your board. Read
2823 doc/README.MBX before setting this variable!
2825 - CONFIG_SYS_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only)
2826 Offset of the bootmode word in DPRAM used by post
2827 (Power On Self Tests). This definition overrides
2828 #define'd default value in commproc.h resp.
2831 - CONFIG_SYS_PCI_SLV_MEM_LOCAL, CONFIG_SYS_PCI_SLV_MEM_BUS, CONFIG_SYS_PICMR0_MASK_ATTRIB,
2832 CONFIG_SYS_PCI_MSTR0_LOCAL, CONFIG_SYS_PCIMSK0_MASK, CONFIG_SYS_PCI_MSTR1_LOCAL,
2833 CONFIG_SYS_PCIMSK1_MASK, CONFIG_SYS_PCI_MSTR_MEM_LOCAL, CONFIG_SYS_PCI_MSTR_MEM_BUS,
2834 CONFIG_SYS_CPU_PCI_MEM_START, CONFIG_SYS_PCI_MSTR_MEM_SIZE, CONFIG_SYS_POCMR0_MASK_ATTRIB,
2835 CONFIG_SYS_PCI_MSTR_MEMIO_LOCAL, CONFIG_SYS_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START,
2836 CONFIG_SYS_PCI_MSTR_MEMIO_SIZE, CONFIG_SYS_POCMR1_MASK_ATTRIB, CONFIG_SYS_PCI_MSTR_IO_LOCAL,
2837 CONFIG_SYS_PCI_MSTR_IO_BUS, CONFIG_SYS_CPU_PCI_IO_START, CONFIG_SYS_PCI_MSTR_IO_SIZE,
2838 CONFIG_SYS_POCMR2_MASK_ATTRIB: (MPC826x only)
2839 Overrides the default PCI memory map in arch/powerpc/cpu/mpc8260/pci.c if set.
2841 - CONFIG_PCI_DISABLE_PCIE:
2842 Disable PCI-Express on systems where it is supported but not
2846 Chip has SRIO or not
2849 Board has SRIO 1 port available
2852 Board has SRIO 2 port available
2854 - CONFIG_SYS_SRIOn_MEM_VIRT:
2855 Virtual Address of SRIO port 'n' memory region
2857 - CONFIG_SYS_SRIOn_MEM_PHYS:
2858 Physical Address of SRIO port 'n' memory region
2860 - CONFIG_SYS_SRIOn_MEM_SIZE:
2861 Size of SRIO port 'n' memory region
2864 Get DDR timing information from an I2C EEPROM. Common
2865 with pluggable memory modules such as SODIMMs
2868 I2C address of the SPD EEPROM
2870 - CONFIG_SYS_SPD_BUS_NUM
2871 If SPD EEPROM is on an I2C bus other than the first
2872 one, specify here. Note that the value must resolve
2873 to something your driver can deal with.
2875 - CONFIG_SYS_83XX_DDR_USES_CS0
2876 Only for 83xx systems. If specified, then DDR should
2877 be configured using CS0 and CS1 instead of CS2 and CS3.
2879 - CONFIG_ETHER_ON_FEC[12]
2880 Define to enable FEC[12] on a 8xx series processor.
2882 - CONFIG_FEC[12]_PHY
2883 Define to the hardcoded PHY address which corresponds
2884 to the given FEC; i. e.
2885 #define CONFIG_FEC1_PHY 4
2886 means that the PHY with address 4 is connected to FEC1
2888 When set to -1, means to probe for first available.
2890 - CONFIG_FEC[12]_PHY_NORXERR
2891 The PHY does not have a RXERR line (RMII only).
2892 (so program the FEC to ignore it).
2895 Enable RMII mode for all FECs.
2896 Note that this is a global option, we can't
2897 have one FEC in standard MII mode and another in RMII mode.
2899 - CONFIG_CRC32_VERIFY
2900 Add a verify option to the crc32 command.
2903 => crc32 -v <address> <count> <crc32>
2905 Where address/count indicate a memory area
2906 and crc32 is the correct crc32 which the
2910 Add the "loopw" memory command. This only takes effect if
2911 the memory commands are activated globally (CONFIG_CMD_MEM).
2914 Add the "mdc" and "mwc" memory commands. These are cyclic
2919 This command will print 4 bytes (10,11,12,13) each 500 ms.
2921 => mwc.l 100 12345678 10
2922 This command will write 12345678 to address 100 all 10 ms.
2924 This only takes effect if the memory commands are activated
2925 globally (CONFIG_CMD_MEM).
2927 - CONFIG_SKIP_LOWLEVEL_INIT
2928 [ARM only] If this variable is defined, then certain
2929 low level initializations (like setting up the memory
2930 controller) are omitted and/or U-Boot does not
2931 relocate itself into RAM.
2933 Normally this variable MUST NOT be defined. The only
2934 exception is when U-Boot is loaded (to RAM) by some
2935 other boot loader or by a debugger which performs
2936 these initializations itself.
2939 Modifies the behaviour of start.S when compiling a loader
2940 that is executed before the actual U-Boot. E.g. when
2941 compiling a NAND SPL.
2943 Building the Software:
2944 ======================
2946 Building U-Boot has been tested in several native build environments
2947 and in many different cross environments. Of course we cannot support
2948 all possibly existing versions of cross development tools in all
2949 (potentially obsolete) versions. In case of tool chain problems we
2950 recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK)
2951 which is extensively used to build and test U-Boot.
2953 If you are not using a native environment, it is assumed that you
2954 have GNU cross compiling tools available in your path. In this case,
2955 you must set the environment variable CROSS_COMPILE in your shell.
2956 Note that no changes to the Makefile or any other source files are
2957 necessary. For example using the ELDK on a 4xx CPU, please enter:
2959 $ CROSS_COMPILE=ppc_4xx-
2960 $ export CROSS_COMPILE
2962 Note: If you wish to generate Windows versions of the utilities in
2963 the tools directory you can use the MinGW toolchain
2964 (http://www.mingw.org). Set your HOST tools to the MinGW
2965 toolchain and execute 'make tools'. For example:
2967 $ make HOSTCC=i586-mingw32msvc-gcc HOSTSTRIP=i586-mingw32msvc-strip tools
2969 Binaries such as tools/mkimage.exe will be created which can
2970 be executed on computers running Windows.
2972 U-Boot is intended to be simple to build. After installing the
2973 sources you must configure U-Boot for one specific board type. This
2978 where "NAME_config" is the name of one of the existing configu-
2979 rations; see the main Makefile for supported names.
2981 Note: for some board special configuration names may exist; check if
2982 additional information is available from the board vendor; for
2983 instance, the TQM823L systems are available without (standard)
2984 or with LCD support. You can select such additional "features"
2985 when choosing the configuration, i. e.
2988 - will configure for a plain TQM823L, i. e. no LCD support
2990 make TQM823L_LCD_config
2991 - will configure for a TQM823L with U-Boot console on LCD
2996 Finally, type "make all", and you should get some working U-Boot
2997 images ready for download to / installation on your system:
2999 - "u-boot.bin" is a raw binary image
3000 - "u-boot" is an image in ELF binary format
3001 - "u-boot.srec" is in Motorola S-Record format
3003 By default the build is performed locally and the objects are saved
3004 in the source directory. One of the two methods can be used to change
3005 this behavior and build U-Boot to some external directory:
3007 1. Add O= to the make command line invocations:
3009 make O=/tmp/build distclean
3010 make O=/tmp/build NAME_config
3011 make O=/tmp/build all
3013 2. Set environment variable BUILD_DIR to point to the desired location:
3015 export BUILD_DIR=/tmp/build
3020 Note that the command line "O=" setting overrides the BUILD_DIR environment
3024 Please be aware that the Makefiles assume you are using GNU make, so
3025 for instance on NetBSD you might need to use "gmake" instead of
3029 If the system board that you have is not listed, then you will need
3030 to port U-Boot to your hardware platform. To do this, follow these
3033 1. Add a new configuration option for your board to the toplevel
3034 "Makefile" and to the "MAKEALL" script, using the existing
3035 entries as examples. Note that here and at many other places
3036 boards and other names are listed in alphabetical sort order. Please
3038 2. Create a new directory to hold your board specific code. Add any
3039 files you need. In your board directory, you will need at least
3040 the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds".
3041 3. Create a new configuration file "include/configs/<board>.h" for
3043 3. If you're porting U-Boot to a new CPU, then also create a new
3044 directory to hold your CPU specific code. Add any files you need.
3045 4. Run "make <board>_config" with your new name.
3046 5. Type "make", and you should get a working "u-boot.srec" file
3047 to be installed on your target system.
3048 6. Debug and solve any problems that might arise.
3049 [Of course, this last step is much harder than it sounds.]
3052 Testing of U-Boot Modifications, Ports to New Hardware, etc.:
3053 ==============================================================
3055 If you have modified U-Boot sources (for instance added a new board
3056 or support for new devices, a new CPU, etc.) you are expected to
3057 provide feedback to the other developers. The feedback normally takes
3058 the form of a "patch", i. e. a context diff against a certain (latest
3059 official or latest in the git repository) version of U-Boot sources.
3061 But before you submit such a patch, please verify that your modifi-
3062 cation did not break existing code. At least make sure that *ALL* of
3063 the supported boards compile WITHOUT ANY compiler warnings. To do so,
3064 just run the "MAKEALL" script, which will configure and build U-Boot
3065 for ALL supported system. Be warned, this will take a while. You can
3066 select which (cross) compiler to use by passing a `CROSS_COMPILE'
3067 environment variable to the script, i. e. to use the ELDK cross tools
3070 CROSS_COMPILE=ppc_8xx- MAKEALL
3072 or to build on a native PowerPC system you can type
3074 CROSS_COMPILE=' ' MAKEALL
3076 When using the MAKEALL script, the default behaviour is to build
3077 U-Boot in the source directory. This location can be changed by
3078 setting the BUILD_DIR environment variable. Also, for each target
3079 built, the MAKEALL script saves two log files (<target>.ERR and
3080 <target>.MAKEALL) in the <source dir>/LOG directory. This default
3081 location can be changed by setting the MAKEALL_LOGDIR environment
3082 variable. For example:
3084 export BUILD_DIR=/tmp/build
3085 export MAKEALL_LOGDIR=/tmp/log
3086 CROSS_COMPILE=ppc_8xx- MAKEALL
3088 With the above settings build objects are saved in the /tmp/build,
3089 log files are saved in the /tmp/log and the source tree remains clean
3090 during the whole build process.
3093 See also "U-Boot Porting Guide" below.
3096 Monitor Commands - Overview:
3097 ============================
3099 go - start application at address 'addr'
3100 run - run commands in an environment variable
3101 bootm - boot application image from memory
3102 bootp - boot image via network using BootP/TFTP protocol
3103 tftpboot- boot image via network using TFTP protocol
3104 and env variables "ipaddr" and "serverip"
3105 (and eventually "gatewayip")
3106 rarpboot- boot image via network using RARP/TFTP protocol
3107 diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
3108 loads - load S-Record file over serial line
3109 loadb - load binary file over serial line (kermit mode)
3111 mm - memory modify (auto-incrementing)
3112 nm - memory modify (constant address)
3113 mw - memory write (fill)
3115 cmp - memory compare
3116 crc32 - checksum calculation
3117 i2c - I2C sub-system
3118 sspi - SPI utility commands
3119 base - print or set address offset
3120 printenv- print environment variables
3121 setenv - set environment variables
3122 saveenv - save environment variables to persistent storage
3123 protect - enable or disable FLASH write protection
3124 erase - erase FLASH memory
3125 flinfo - print FLASH memory information
3126 bdinfo - print Board Info structure
3127 iminfo - print header information for application image
3128 coninfo - print console devices and informations
3129 ide - IDE sub-system
3130 loop - infinite loop on address range
3131 loopw - infinite write loop on address range
3132 mtest - simple RAM test
3133 icache - enable or disable instruction cache
3134 dcache - enable or disable data cache
3135 reset - Perform RESET of the CPU
3136 echo - echo args to console
3137 version - print monitor version
3138 help - print online help
3139 ? - alias for 'help'
3142 Monitor Commands - Detailed Description:
3143 ========================================
3147 For now: just type "help <command>".
3150 Environment Variables:
3151 ======================
3153 U-Boot supports user configuration using Environment Variables which
3154 can be made persistent by saving to Flash memory.
3156 Environment Variables are set using "setenv", printed using
3157 "printenv", and saved to Flash using "saveenv". Using "setenv"
3158 without a value can be used to delete a variable from the
3159 environment. As long as you don't save the environment you are
3160 working with an in-memory copy. In case the Flash area containing the
3161 environment is erased by accident, a default environment is provided.
3163 Some configuration options can be set using Environment Variables.
3165 List of environment variables (most likely not complete):
3167 baudrate - see CONFIG_BAUDRATE
3169 bootdelay - see CONFIG_BOOTDELAY
3171 bootcmd - see CONFIG_BOOTCOMMAND
3173 bootargs - Boot arguments when booting an RTOS image
3175 bootfile - Name of the image to load with TFTP
3177 bootm_low - Memory range available for image processing in the bootm
3178 command can be restricted. This variable is given as
3179 a hexadecimal number and defines lowest address allowed
3180 for use by the bootm command. See also "bootm_size"
3181 environment variable. Address defined by "bootm_low" is
3182 also the base of the initial memory mapping for the Linux
3183 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ.
3185 bootm_size - Memory range available for image processing in the bootm
3186 command can be restricted. This variable is given as
3187 a hexadecimal number and defines the size of the region
3188 allowed for use by the bootm command. See also "bootm_low"
3189 environment variable.
3191 updatefile - Location of the software update file on a TFTP server, used
3192 by the automatic software update feature. Please refer to
3193 documentation in doc/README.update for more details.
3195 autoload - if set to "no" (any string beginning with 'n'),
3196 "bootp" will just load perform a lookup of the
3197 configuration from the BOOTP server, but not try to
3198 load any image using TFTP
3200 autostart - if set to "yes", an image loaded using the "bootp",
3201 "rarpboot", "tftpboot" or "diskboot" commands will
3202 be automatically started (by internally calling
3205 If set to "no", a standalone image passed to the
3206 "bootm" command will be copied to the load address
3207 (and eventually uncompressed), but NOT be started.
3208 This can be used to load and uncompress arbitrary
3211 i2cfast - (PPC405GP|PPC405EP only)
3212 if set to 'y' configures Linux I2C driver for fast
3213 mode (400kHZ). This environment variable is used in
3214 initialization code. So, for changes to be effective
3215 it must be saved and board must be reset.
3217 initrd_high - restrict positioning of initrd images:
3218 If this variable is not set, initrd images will be
3219 copied to the highest possible address in RAM; this
3220 is usually what you want since it allows for
3221 maximum initrd size. If for some reason you want to
3222 make sure that the initrd image is loaded below the
3223 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment
3224 variable to a value of "no" or "off" or "0".
3225 Alternatively, you can set it to a maximum upper
3226 address to use (U-Boot will still check that it
3227 does not overwrite the U-Boot stack and data).
3229 For instance, when you have a system with 16 MB
3230 RAM, and want to reserve 4 MB from use by Linux,
3231 you can do this by adding "mem=12M" to the value of
3232 the "bootargs" variable. However, now you must make
3233 sure that the initrd image is placed in the first
3234 12 MB as well - this can be done with
3236 setenv initrd_high 00c00000
3238 If you set initrd_high to 0xFFFFFFFF, this is an
3239 indication to U-Boot that all addresses are legal
3240 for the Linux kernel, including addresses in flash
3241 memory. In this case U-Boot will NOT COPY the
3242 ramdisk at all. This may be useful to reduce the
3243 boot time on your system, but requires that this
3244 feature is supported by your Linux kernel.
3246 ipaddr - IP address; needed for tftpboot command
3248 loadaddr - Default load address for commands like "bootp",
3249 "rarpboot", "tftpboot", "loadb" or "diskboot"
3251 loads_echo - see CONFIG_LOADS_ECHO
3253 serverip - TFTP server IP address; needed for tftpboot command
3255 bootretry - see CONFIG_BOOT_RETRY_TIME
3257 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
3259 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
3261 ethprime - When CONFIG_NET_MULTI is enabled controls which
3262 interface is used first.
3264 ethact - When CONFIG_NET_MULTI is enabled controls which
3265 interface is currently active. For example you
3266 can do the following
3268 => setenv ethact FEC
3269 => ping 192.168.0.1 # traffic sent on FEC
3270 => setenv ethact SCC
3271 => ping 10.0.0.1 # traffic sent on SCC
3273 ethrotate - When set to "no" U-Boot does not go through all
3274 available network interfaces.
3275 It just stays at the currently selected interface.
3277 netretry - When set to "no" each network operation will
3278 either succeed or fail without retrying.
3279 When set to "once" the network operation will
3280 fail when all the available network interfaces
3281 are tried once without success.
3282 Useful on scripts which control the retry operation
3285 npe_ucode - set load address for the NPE microcode
3287 tftpsrcport - If this is set, the value is used for TFTP's
3290 tftpdstport - If this is set, the value is used for TFTP's UDP
3291 destination port instead of the Well Know Port 69.
3293 tftpblocksize - Block size to use for TFTP transfers; if not set,
3294 we use the TFTP server's default block size
3296 tftptimeout - Retransmission timeout for TFTP packets (in milli-
3297 seconds, minimum value is 1000 = 1 second). Defines
3298 when a packet is considered to be lost so it has to
3299 be retransmitted. The default is 5000 = 5 seconds.
3300 Lowering this value may make downloads succeed
3301 faster in networks with high packet loss rates or
3302 with unreliable TFTP servers.
3304 vlan - When set to a value < 4095 the traffic over
3305 Ethernet is encapsulated/received over 802.1q
3308 The following environment variables may be used and automatically
3309 updated by the network boot commands ("bootp" and "rarpboot"),
3310 depending the information provided by your boot server:
3312 bootfile - see above
3313 dnsip - IP address of your Domain Name Server
3314 dnsip2 - IP address of your secondary Domain Name Server
3315 gatewayip - IP address of the Gateway (Router) to use
3316 hostname - Target hostname
3318 netmask - Subnet Mask
3319 rootpath - Pathname of the root filesystem on the NFS server
3320 serverip - see above
3323 There are two special Environment Variables:
3325 serial# - contains hardware identification information such
3326 as type string and/or serial number
3327 ethaddr - Ethernet address
3329 These variables can be set only once (usually during manufacturing of
3330 the board). U-Boot refuses to delete or overwrite these variables
3331 once they have been set once.
3334 Further special Environment Variables:
3336 ver - Contains the U-Boot version string as printed
3337 with the "version" command. This variable is
3338 readonly (see CONFIG_VERSION_VARIABLE).
3341 Please note that changes to some configuration parameters may take
3342 only effect after the next boot (yes, that's just like Windoze :-).
3345 Command Line Parsing:
3346 =====================
3348 There are two different command line parsers available with U-Boot:
3349 the old "simple" one, and the much more powerful "hush" shell:
3351 Old, simple command line parser:
3352 --------------------------------
3354 - supports environment variables (through setenv / saveenv commands)
3355 - several commands on one line, separated by ';'
3356 - variable substitution using "... ${name} ..." syntax
3357 - special characters ('$', ';') can be escaped by prefixing with '\',
3359 setenv bootcmd bootm \${address}
3360 - You can also escape text by enclosing in single apostrophes, for example:
3361 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
3366 - similar to Bourne shell, with control structures like
3367 if...then...else...fi, for...do...done; while...do...done,
3368 until...do...done, ...
3369 - supports environment ("global") variables (through setenv / saveenv
3370 commands) and local shell variables (through standard shell syntax
3371 "name=value"); only environment variables can be used with "run"
3377 (1) If a command line (or an environment variable executed by a "run"
3378 command) contains several commands separated by semicolon, and
3379 one of these commands fails, then the remaining commands will be
3382 (2) If you execute several variables with one call to run (i. e.
3383 calling run with a list of variables as arguments), any failing
3384 command will cause "run" to terminate, i. e. the remaining
3385 variables are not executed.
3387 Note for Redundant Ethernet Interfaces:
3388 =======================================
3390 Some boards come with redundant Ethernet interfaces; U-Boot supports
3391 such configurations and is capable of automatic selection of a
3392 "working" interface when needed. MAC assignment works as follows:
3394 Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
3395 MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
3396 "eth1addr" (=>eth1), "eth2addr", ...
3398 If the network interface stores some valid MAC address (for instance
3399 in SROM), this is used as default address if there is NO correspon-
3400 ding setting in the environment; if the corresponding environment
3401 variable is set, this overrides the settings in the card; that means:
3403 o If the SROM has a valid MAC address, and there is no address in the
3404 environment, the SROM's address is used.
3406 o If there is no valid address in the SROM, and a definition in the
3407 environment exists, then the value from the environment variable is
3410 o If both the SROM and the environment contain a MAC address, and
3411 both addresses are the same, this MAC address is used.
3413 o If both the SROM and the environment contain a MAC address, and the
3414 addresses differ, the value from the environment is used and a
3417 o If neither SROM nor the environment contain a MAC address, an error
3420 If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses
3421 will be programmed into hardware as part of the initialization process. This
3422 may be skipped by setting the appropriate 'ethmacskip' environment variable.
3423 The naming convention is as follows:
3424 "ethmacskip" (=>eth0), "eth1macskip" (=>eth1) etc.
3429 U-Boot is capable of booting (and performing other auxiliary operations on)
3430 images in two formats:
3432 New uImage format (FIT)
3433 -----------------------
3435 Flexible and powerful format based on Flattened Image Tree -- FIT (similar
3436 to Flattened Device Tree). It allows the use of images with multiple
3437 components (several kernels, ramdisks, etc.), with contents protected by
3438 SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory.
3444 Old image format is based on binary files which can be basically anything,
3445 preceded by a special header; see the definitions in include/image.h for
3446 details; basically, the header defines the following image properties:
3448 * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
3449 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
3450 LynxOS, pSOS, QNX, RTEMS, INTEGRITY;
3451 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS,
3453 * Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86,
3454 IA64, MIPS, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
3455 Currently supported: ARM, AVR32, Intel x86, MIPS, Nios II, PowerPC).
3456 * Compression Type (uncompressed, gzip, bzip2)
3462 The header is marked by a special Magic Number, and both the header
3463 and the data portions of the image are secured against corruption by
3470 Although U-Boot should support any OS or standalone application
3471 easily, the main focus has always been on Linux during the design of
3474 U-Boot includes many features that so far have been part of some
3475 special "boot loader" code within the Linux kernel. Also, any
3476 "initrd" images to be used are no longer part of one big Linux image;
3477 instead, kernel and "initrd" are separate images. This implementation
3478 serves several purposes:
3480 - the same features can be used for other OS or standalone
3481 applications (for instance: using compressed images to reduce the
3482 Flash memory footprint)
3484 - it becomes much easier to port new Linux kernel versions because
3485 lots of low-level, hardware dependent stuff are done by U-Boot
3487 - the same Linux kernel image can now be used with different "initrd"
3488 images; of course this also means that different kernel images can
3489 be run with the same "initrd". This makes testing easier (you don't
3490 have to build a new "zImage.initrd" Linux image when you just
3491 change a file in your "initrd"). Also, a field-upgrade of the
3492 software is easier now.
3498 Porting Linux to U-Boot based systems:
3499 ---------------------------------------
3501 U-Boot cannot save you from doing all the necessary modifications to
3502 configure the Linux device drivers for use with your target hardware
3503 (no, we don't intend to provide a full virtual machine interface to
3506 But now you can ignore ALL boot loader code (in arch/powerpc/mbxboot).
3508 Just make sure your machine specific header file (for instance
3509 include/asm-ppc/tqm8xx.h) includes the same definition of the Board
3510 Information structure as we define in include/asm-<arch>/u-boot.h,
3511 and make sure that your definition of IMAP_ADDR uses the same value
3512 as your U-Boot configuration in CONFIG_SYS_IMMR.
3515 Configuring the Linux kernel:
3516 -----------------------------
3518 No specific requirements for U-Boot. Make sure you have some root
3519 device (initial ramdisk, NFS) for your target system.
3522 Building a Linux Image:
3523 -----------------------
3525 With U-Boot, "normal" build targets like "zImage" or "bzImage" are
3526 not used. If you use recent kernel source, a new build target
3527 "uImage" will exist which automatically builds an image usable by
3528 U-Boot. Most older kernels also have support for a "pImage" target,
3529 which was introduced for our predecessor project PPCBoot and uses a
3530 100% compatible format.
3539 The "uImage" build target uses a special tool (in 'tools/mkimage') to
3540 encapsulate a compressed Linux kernel image with header information,
3541 CRC32 checksum etc. for use with U-Boot. This is what we are doing:
3543 * build a standard "vmlinux" kernel image (in ELF binary format):
3545 * convert the kernel into a raw binary image:
3547 ${CROSS_COMPILE}-objcopy -O binary \
3548 -R .note -R .comment \
3549 -S vmlinux linux.bin
3551 * compress the binary image:
3555 * package compressed binary image for U-Boot:
3557 mkimage -A ppc -O linux -T kernel -C gzip \
3558 -a 0 -e 0 -n "Linux Kernel Image" \
3559 -d linux.bin.gz uImage
3562 The "mkimage" tool can also be used to create ramdisk images for use
3563 with U-Boot, either separated from the Linux kernel image, or
3564 combined into one file. "mkimage" encapsulates the images with a 64
3565 byte header containing information about target architecture,
3566 operating system, image type, compression method, entry points, time
3567 stamp, CRC32 checksums, etc.
3569 "mkimage" can be called in two ways: to verify existing images and
3570 print the header information, or to build new images.
3572 In the first form (with "-l" option) mkimage lists the information
3573 contained in the header of an existing U-Boot image; this includes
3574 checksum verification:
3576 tools/mkimage -l image
3577 -l ==> list image header information
3579 The second form (with "-d" option) is used to build a U-Boot image
3580 from a "data file" which is used as image payload:
3582 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
3583 -n name -d data_file image
3584 -A ==> set architecture to 'arch'
3585 -O ==> set operating system to 'os'
3586 -T ==> set image type to 'type'
3587 -C ==> set compression type 'comp'
3588 -a ==> set load address to 'addr' (hex)
3589 -e ==> set entry point to 'ep' (hex)
3590 -n ==> set image name to 'name'
3591 -d ==> use image data from 'datafile'
3593 Right now, all Linux kernels for PowerPC systems use the same load
3594 address (0x00000000), but the entry point address depends on the
3597 - 2.2.x kernels have the entry point at 0x0000000C,
3598 - 2.3.x and later kernels have the entry point at 0x00000000.
3600 So a typical call to build a U-Boot image would read:
3602 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
3603 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
3604 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz \
3605 > examples/uImage.TQM850L
3606 Image Name: 2.4.4 kernel for TQM850L
3607 Created: Wed Jul 19 02:34:59 2000
3608 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3609 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
3610 Load Address: 0x00000000
3611 Entry Point: 0x00000000
3613 To verify the contents of the image (or check for corruption):
3615 -> tools/mkimage -l examples/uImage.TQM850L
3616 Image Name: 2.4.4 kernel for TQM850L
3617 Created: Wed Jul 19 02:34:59 2000
3618 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3619 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
3620 Load Address: 0x00000000
3621 Entry Point: 0x00000000
3623 NOTE: for embedded systems where boot time is critical you can trade
3624 speed for memory and install an UNCOMPRESSED image instead: this
3625 needs more space in Flash, but boots much faster since it does not
3626 need to be uncompressed:
3628 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz
3629 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
3630 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
3631 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux \
3632 > examples/uImage.TQM850L-uncompressed
3633 Image Name: 2.4.4 kernel for TQM850L
3634 Created: Wed Jul 19 02:34:59 2000
3635 Image Type: PowerPC Linux Kernel Image (uncompressed)
3636 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
3637 Load Address: 0x00000000
3638 Entry Point: 0x00000000
3641 Similar you can build U-Boot images from a 'ramdisk.image.gz' file
3642 when your kernel is intended to use an initial ramdisk:
3644 -> tools/mkimage -n 'Simple Ramdisk Image' \
3645 > -A ppc -O linux -T ramdisk -C gzip \
3646 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
3647 Image Name: Simple Ramdisk Image
3648 Created: Wed Jan 12 14:01:50 2000
3649 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
3650 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
3651 Load Address: 0x00000000
3652 Entry Point: 0x00000000
3655 Installing a Linux Image:
3656 -------------------------
3658 To downloading a U-Boot image over the serial (console) interface,
3659 you must convert the image to S-Record format:
3661 objcopy -I binary -O srec examples/image examples/image.srec
3663 The 'objcopy' does not understand the information in the U-Boot
3664 image header, so the resulting S-Record file will be relative to
3665 address 0x00000000. To load it to a given address, you need to
3666 specify the target address as 'offset' parameter with the 'loads'
3669 Example: install the image to address 0x40100000 (which on the
3670 TQM8xxL is in the first Flash bank):
3672 => erase 40100000 401FFFFF
3678 ## Ready for S-Record download ...
3679 ~>examples/image.srec
3680 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
3682 15989 15990 15991 15992
3683 [file transfer complete]
3685 ## Start Addr = 0x00000000
3688 You can check the success of the download using the 'iminfo' command;
3689 this includes a checksum verification so you can be sure no data
3690 corruption happened:
3694 ## Checking Image at 40100000 ...
3695 Image Name: 2.2.13 for initrd on TQM850L
3696 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3697 Data Size: 335725 Bytes = 327 kB = 0 MB
3698 Load Address: 00000000
3699 Entry Point: 0000000c
3700 Verifying Checksum ... OK
3706 The "bootm" command is used to boot an application that is stored in
3707 memory (RAM or Flash). In case of a Linux kernel image, the contents
3708 of the "bootargs" environment variable is passed to the kernel as
3709 parameters. You can check and modify this variable using the
3710 "printenv" and "setenv" commands:
3713 => printenv bootargs
3714 bootargs=root=/dev/ram
3716 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
3718 => printenv bootargs
3719 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
3722 ## Booting Linux kernel at 40020000 ...
3723 Image Name: 2.2.13 for NFS on TQM850L
3724 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3725 Data Size: 381681 Bytes = 372 kB = 0 MB
3726 Load Address: 00000000
3727 Entry Point: 0000000c
3728 Verifying Checksum ... OK
3729 Uncompressing Kernel Image ... OK
3730 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
3731 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
3732 time_init: decrementer frequency = 187500000/60
3733 Calibrating delay loop... 49.77 BogoMIPS
3734 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
3737 If you want to boot a Linux kernel with initial RAM disk, you pass
3738 the memory addresses of both the kernel and the initrd image (PPBCOOT
3739 format!) to the "bootm" command:
3741 => imi 40100000 40200000
3743 ## Checking Image at 40100000 ...
3744 Image Name: 2.2.13 for initrd on TQM850L
3745 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3746 Data Size: 335725 Bytes = 327 kB = 0 MB
3747 Load Address: 00000000
3748 Entry Point: 0000000c
3749 Verifying Checksum ... OK
3751 ## Checking Image at 40200000 ...
3752 Image Name: Simple Ramdisk Image
3753 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
3754 Data Size: 566530 Bytes = 553 kB = 0 MB
3755 Load Address: 00000000
3756 Entry Point: 00000000
3757 Verifying Checksum ... OK
3759 => bootm 40100000 40200000
3760 ## Booting Linux kernel at 40100000 ...
3761 Image Name: 2.2.13 for initrd on TQM850L
3762 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3763 Data Size: 335725 Bytes = 327 kB = 0 MB
3764 Load Address: 00000000
3765 Entry Point: 0000000c
3766 Verifying Checksum ... OK
3767 Uncompressing Kernel Image ... OK
3768 ## Loading RAMDisk Image at 40200000 ...
3769 Image Name: Simple Ramdisk Image
3770 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
3771 Data Size: 566530 Bytes = 553 kB = 0 MB
3772 Load Address: 00000000
3773 Entry Point: 00000000
3774 Verifying Checksum ... OK
3775 Loading Ramdisk ... OK
3776 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
3777 Boot arguments: root=/dev/ram
3778 time_init: decrementer frequency = 187500000/60
3779 Calibrating delay loop... 49.77 BogoMIPS
3781 RAMDISK: Compressed image found at block 0
3782 VFS: Mounted root (ext2 filesystem).
3786 Boot Linux and pass a flat device tree:
3789 First, U-Boot must be compiled with the appropriate defines. See the section
3790 titled "Linux Kernel Interface" above for a more in depth explanation. The
3791 following is an example of how to start a kernel and pass an updated
3797 oft=oftrees/mpc8540ads.dtb
3798 => tftp $oftaddr $oft
3799 Speed: 1000, full duplex
3801 TFTP from server 192.168.1.1; our IP address is 192.168.1.101
3802 Filename 'oftrees/mpc8540ads.dtb'.
3803 Load address: 0x300000
3806 Bytes transferred = 4106 (100a hex)
3807 => tftp $loadaddr $bootfile
3808 Speed: 1000, full duplex
3810 TFTP from server 192.168.1.1; our IP address is 192.168.1.2
3812 Load address: 0x200000
3813 Loading:############
3815 Bytes transferred = 1029407 (fb51f hex)
3820 => bootm $loadaddr - $oftaddr
3821 ## Booting image at 00200000 ...
3822 Image Name: Linux-2.6.17-dirty
3823 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3824 Data Size: 1029343 Bytes = 1005.2 kB
3825 Load Address: 00000000
3826 Entry Point: 00000000
3827 Verifying Checksum ... OK
3828 Uncompressing Kernel Image ... OK
3829 Booting using flat device tree at 0x300000
3830 Using MPC85xx ADS machine description
3831 Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb
3835 More About U-Boot Image Types:
3836 ------------------------------
3838 U-Boot supports the following image types:
3840 "Standalone Programs" are directly runnable in the environment
3841 provided by U-Boot; it is expected that (if they behave
3842 well) you can continue to work in U-Boot after return from
3843 the Standalone Program.
3844 "OS Kernel Images" are usually images of some Embedded OS which
3845 will take over control completely. Usually these programs
3846 will install their own set of exception handlers, device
3847 drivers, set up the MMU, etc. - this means, that you cannot
3848 expect to re-enter U-Boot except by resetting the CPU.
3849 "RAMDisk Images" are more or less just data blocks, and their
3850 parameters (address, size) are passed to an OS kernel that is
3852 "Multi-File Images" contain several images, typically an OS
3853 (Linux) kernel image and one or more data images like
3854 RAMDisks. This construct is useful for instance when you want
3855 to boot over the network using BOOTP etc., where the boot
3856 server provides just a single image file, but you want to get
3857 for instance an OS kernel and a RAMDisk image.
3859 "Multi-File Images" start with a list of image sizes, each
3860 image size (in bytes) specified by an "uint32_t" in network
3861 byte order. This list is terminated by an "(uint32_t)0".
3862 Immediately after the terminating 0 follow the images, one by
3863 one, all aligned on "uint32_t" boundaries (size rounded up to
3864 a multiple of 4 bytes).
3866 "Firmware Images" are binary images containing firmware (like
3867 U-Boot or FPGA images) which usually will be programmed to
3870 "Script files" are command sequences that will be executed by
3871 U-Boot's command interpreter; this feature is especially
3872 useful when you configure U-Boot to use a real shell (hush)
3873 as command interpreter.
3879 One of the features of U-Boot is that you can dynamically load and
3880 run "standalone" applications, which can use some resources of
3881 U-Boot like console I/O functions or interrupt services.
3883 Two simple examples are included with the sources:
3888 'examples/hello_world.c' contains a small "Hello World" Demo
3889 application; it is automatically compiled when you build U-Boot.
3890 It's configured to run at address 0x00040004, so you can play with it
3894 ## Ready for S-Record download ...
3895 ~>examples/hello_world.srec
3896 1 2 3 4 5 6 7 8 9 10 11 ...
3897 [file transfer complete]
3899 ## Start Addr = 0x00040004
3901 => go 40004 Hello World! This is a test.
3902 ## Starting application at 0x00040004 ...
3913 Hit any key to exit ...
3915 ## Application terminated, rc = 0x0
3917 Another example, which demonstrates how to register a CPM interrupt
3918 handler with the U-Boot code, can be found in 'examples/timer.c'.
3919 Here, a CPM timer is set up to generate an interrupt every second.
3920 The interrupt service routine is trivial, just printing a '.'
3921 character, but this is just a demo program. The application can be
3922 controlled by the following keys:
3924 ? - print current values og the CPM Timer registers
3925 b - enable interrupts and start timer
3926 e - stop timer and disable interrupts
3927 q - quit application
3930 ## Ready for S-Record download ...
3931 ~>examples/timer.srec
3932 1 2 3 4 5 6 7 8 9 10 11 ...
3933 [file transfer complete]
3935 ## Start Addr = 0x00040004
3938 ## Starting application at 0x00040004 ...
3941 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
3944 [q, b, e, ?] Set interval 1000000 us
3947 [q, b, e, ?] ........
3948 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
3951 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
3954 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
3957 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
3959 [q, b, e, ?] ...Stopping timer
3961 [q, b, e, ?] ## Application terminated, rc = 0x0
3967 Over time, many people have reported problems when trying to use the
3968 "minicom" terminal emulation program for serial download. I (wd)
3969 consider minicom to be broken, and recommend not to use it. Under
3970 Unix, I recommend to use C-Kermit for general purpose use (and
3971 especially for kermit binary protocol download ("loadb" command), and
3972 use "cu" for S-Record download ("loads" command).
3974 Nevertheless, if you absolutely want to use it try adding this
3975 configuration to your "File transfer protocols" section:
3977 Name Program Name U/D FullScr IO-Red. Multi
3978 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
3979 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
3985 Starting at version 0.9.2, U-Boot supports NetBSD both as host
3986 (build U-Boot) and target system (boots NetBSD/mpc8xx).
3988 Building requires a cross environment; it is known to work on
3989 NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
3990 need gmake since the Makefiles are not compatible with BSD make).
3991 Note that the cross-powerpc package does not install include files;
3992 attempting to build U-Boot will fail because <machine/ansi.h> is
3993 missing. This file has to be installed and patched manually:
3995 # cd /usr/pkg/cross/powerpc-netbsd/include
3997 # ln -s powerpc machine
3998 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
3999 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
4001 Native builds *don't* work due to incompatibilities between native
4002 and U-Boot include files.
4004 Booting assumes that (the first part of) the image booted is a
4005 stage-2 loader which in turn loads and then invokes the kernel
4006 proper. Loader sources will eventually appear in the NetBSD source
4007 tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
4008 meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz
4011 Implementation Internals:
4012 =========================
4014 The following is not intended to be a complete description of every
4015 implementation detail. However, it should help to understand the
4016 inner workings of U-Boot and make it easier to port it to custom
4020 Initial Stack, Global Data:
4021 ---------------------------
4023 The implementation of U-Boot is complicated by the fact that U-Boot
4024 starts running out of ROM (flash memory), usually without access to
4025 system RAM (because the memory controller is not initialized yet).
4026 This means that we don't have writable Data or BSS segments, and BSS
4027 is not initialized as zero. To be able to get a C environment working
4028 at all, we have to allocate at least a minimal stack. Implementation
4029 options for this are defined and restricted by the CPU used: Some CPU
4030 models provide on-chip memory (like the IMMR area on MPC8xx and
4031 MPC826x processors), on others (parts of) the data cache can be
4032 locked as (mis-) used as memory, etc.
4034 Chris Hallinan posted a good summary of these issues to the
4035 U-Boot mailing list:
4037 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
4038 From: "Chris Hallinan" <clh@net1plus.com>
4039 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
4042 Correct me if I'm wrong, folks, but the way I understand it
4043 is this: Using DCACHE as initial RAM for Stack, etc, does not
4044 require any physical RAM backing up the cache. The cleverness
4045 is that the cache is being used as a temporary supply of
4046 necessary storage before the SDRAM controller is setup. It's
4047 beyond the scope of this list to explain the details, but you
4048 can see how this works by studying the cache architecture and
4049 operation in the architecture and processor-specific manuals.
4051 OCM is On Chip Memory, which I believe the 405GP has 4K. It
4052 is another option for the system designer to use as an
4053 initial stack/RAM area prior to SDRAM being available. Either
4054 option should work for you. Using CS 4 should be fine if your
4055 board designers haven't used it for something that would
4056 cause you grief during the initial boot! It is frequently not
4059 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere
4060 with your processor/board/system design. The default value
4061 you will find in any recent u-boot distribution in
4062 walnut.h should work for you. I'd set it to a value larger
4063 than your SDRAM module. If you have a 64MB SDRAM module, set
4064 it above 400_0000. Just make sure your board has no resources
4065 that are supposed to respond to that address! That code in
4066 start.S has been around a while and should work as is when
4067 you get the config right.
4072 It is essential to remember this, since it has some impact on the C
4073 code for the initialization procedures:
4075 * Initialized global data (data segment) is read-only. Do not attempt
4078 * Do not use any uninitialized global data (or implicitely initialized
4079 as zero data - BSS segment) at all - this is undefined, initiali-
4080 zation is performed later (when relocating to RAM).
4082 * Stack space is very limited. Avoid big data buffers or things like
4085 Having only the stack as writable memory limits means we cannot use
4086 normal global data to share information beween the code. But it
4087 turned out that the implementation of U-Boot can be greatly
4088 simplified by making a global data structure (gd_t) available to all
4089 functions. We could pass a pointer to this data as argument to _all_
4090 functions, but this would bloat the code. Instead we use a feature of
4091 the GCC compiler (Global Register Variables) to share the data: we
4092 place a pointer (gd) to the global data into a register which we
4093 reserve for this purpose.
4095 When choosing a register for such a purpose we are restricted by the
4096 relevant (E)ABI specifications for the current architecture, and by
4097 GCC's implementation.
4099 For PowerPC, the following registers have specific use:
4101 R2: reserved for system use
4102 R3-R4: parameter passing and return values
4103 R5-R10: parameter passing
4104 R13: small data area pointer
4108 (U-Boot also uses R12 as internal GOT pointer. r12
4109 is a volatile register so r12 needs to be reset when
4110 going back and forth between asm and C)
4112 ==> U-Boot will use R2 to hold a pointer to the global data
4114 Note: on PPC, we could use a static initializer (since the
4115 address of the global data structure is known at compile time),
4116 but it turned out that reserving a register results in somewhat
4117 smaller code - although the code savings are not that big (on
4118 average for all boards 752 bytes for the whole U-Boot image,
4119 624 text + 127 data).
4121 On Blackfin, the normal C ABI (except for P3) is followed as documented here:
4122 http://docs.blackfin.uclinux.org/doku.php?id=application_binary_interface
4124 ==> U-Boot will use P3 to hold a pointer to the global data
4126 On ARM, the following registers are used:
4128 R0: function argument word/integer result
4129 R1-R3: function argument word
4131 R10: stack limit (used only if stack checking if enabled)
4132 R11: argument (frame) pointer
4133 R12: temporary workspace
4136 R15: program counter
4138 ==> U-Boot will use R8 to hold a pointer to the global data
4140 On Nios II, the ABI is documented here:
4141 http://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf
4143 ==> U-Boot will use gp to hold a pointer to the global data
4145 Note: on Nios II, we give "-G0" option to gcc and don't use gp
4146 to access small data sections, so gp is free.
4148 NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope,
4149 or current versions of GCC may "optimize" the code too much.
4154 U-Boot runs in system state and uses physical addresses, i.e. the
4155 MMU is not used either for address mapping nor for memory protection.
4157 The available memory is mapped to fixed addresses using the memory
4158 controller. In this process, a contiguous block is formed for each
4159 memory type (Flash, SDRAM, SRAM), even when it consists of several
4160 physical memory banks.
4162 U-Boot is installed in the first 128 kB of the first Flash bank (on
4163 TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
4164 booting and sizing and initializing DRAM, the code relocates itself
4165 to the upper end of DRAM. Immediately below the U-Boot code some
4166 memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN
4167 configuration setting]. Below that, a structure with global Board
4168 Info data is placed, followed by the stack (growing downward).
4170 Additionally, some exception handler code is copied to the low 8 kB
4171 of DRAM (0x00000000 ... 0x00001FFF).
4173 So a typical memory configuration with 16 MB of DRAM could look like
4176 0x0000 0000 Exception Vector code
4179 0x0000 2000 Free for Application Use
4185 0x00FB FF20 Monitor Stack (Growing downward)
4186 0x00FB FFAC Board Info Data and permanent copy of global data
4187 0x00FC 0000 Malloc Arena
4190 0x00FE 0000 RAM Copy of Monitor Code
4191 ... eventually: LCD or video framebuffer
4192 ... eventually: pRAM (Protected RAM - unchanged by reset)
4193 0x00FF FFFF [End of RAM]
4196 System Initialization:
4197 ----------------------
4199 In the reset configuration, U-Boot starts at the reset entry point
4200 (on most PowerPC systems at address 0x00000100). Because of the reset
4201 configuration for CS0# this is a mirror of the onboard Flash memory.
4202 To be able to re-map memory U-Boot then jumps to its link address.
4203 To be able to implement the initialization code in C, a (small!)
4204 initial stack is set up in the internal Dual Ported RAM (in case CPUs
4205 which provide such a feature like MPC8xx or MPC8260), or in a locked
4206 part of the data cache. After that, U-Boot initializes the CPU core,
4207 the caches and the SIU.
4209 Next, all (potentially) available memory banks are mapped using a
4210 preliminary mapping. For example, we put them on 512 MB boundaries
4211 (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
4212 on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
4213 programmed for SDRAM access. Using the temporary configuration, a
4214 simple memory test is run that determines the size of the SDRAM
4217 When there is more than one SDRAM bank, and the banks are of
4218 different size, the largest is mapped first. For equal size, the first
4219 bank (CS2#) is mapped first. The first mapping is always for address
4220 0x00000000, with any additional banks following immediately to create
4221 contiguous memory starting from 0.
4223 Then, the monitor installs itself at the upper end of the SDRAM area
4224 and allocates memory for use by malloc() and for the global Board
4225 Info data; also, the exception vector code is copied to the low RAM
4226 pages, and the final stack is set up.
4228 Only after this relocation will you have a "normal" C environment;
4229 until that you are restricted in several ways, mostly because you are
4230 running from ROM, and because the code will have to be relocated to a
4234 U-Boot Porting Guide:
4235 ----------------------
4237 [Based on messages by Jerry Van Baren in the U-Boot-Users mailing
4241 int main(int argc, char *argv[])
4243 sighandler_t no_more_time;
4245 signal(SIGALRM, no_more_time);
4246 alarm(PROJECT_DEADLINE - toSec (3 * WEEK));
4248 if (available_money > available_manpower) {
4249 Pay consultant to port U-Boot;
4253 Download latest U-Boot source;
4255 Subscribe to u-boot mailing list;
4258 email("Hi, I am new to U-Boot, how do I get started?");
4261 Read the README file in the top level directory;
4262 Read http://www.denx.de/twiki/bin/view/DULG/Manual;
4263 Read applicable doc/*.README;
4264 Read the source, Luke;
4265 /* find . -name "*.[chS]" | xargs grep -i <keyword> */
4268 if (available_money > toLocalCurrency ($2500))
4271 Add a lot of aggravation and time;
4273 if (a similar board exists) { /* hopefully... */
4274 cp -a board/<similar> board/<myboard>
4275 cp include/configs/<similar>.h include/configs/<myboard>.h
4277 Create your own board support subdirectory;
4278 Create your own board include/configs/<myboard>.h file;
4280 Edit new board/<myboard> files
4281 Edit new include/configs/<myboard>.h
4286 Add / modify source code;
4290 email("Hi, I am having problems...");
4292 Send patch file to the U-Boot email list;
4293 if (reasonable critiques)
4294 Incorporate improvements from email list code review;
4296 Defend code as written;
4302 void no_more_time (int sig)
4311 All contributions to U-Boot should conform to the Linux kernel
4312 coding style; see the file "Documentation/CodingStyle" and the script
4313 "scripts/Lindent" in your Linux kernel source directory. In sources
4314 originating from U-Boot a style corresponding to "Lindent -pcs" (adding
4315 spaces before parameters to function calls) is actually used.
4317 Source files originating from a different project (for example the
4318 MTD subsystem) are generally exempt from these guidelines and are not
4319 reformated to ease subsequent migration to newer versions of those
4322 Please note that U-Boot is implemented in C (and to some small parts in
4323 Assembler); no C++ is used, so please do not use C++ style comments (//)
4326 Please also stick to the following formatting rules:
4327 - remove any trailing white space
4328 - use TAB characters for indentation, not spaces
4329 - make sure NOT to use DOS '\r\n' line feeds
4330 - do not add more than 2 empty lines to source files
4331 - do not add trailing empty lines to source files
4333 Submissions which do not conform to the standards may be returned
4334 with a request to reformat the changes.
4340 Since the number of patches for U-Boot is growing, we need to
4341 establish some rules. Submissions which do not conform to these rules
4342 may be rejected, even when they contain important and valuable stuff.
4344 Please see http://www.denx.de/wiki/U-Boot/Patches for details.
4346 Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>;
4347 see http://lists.denx.de/mailman/listinfo/u-boot
4349 When you send a patch, please include the following information with
4352 * For bug fixes: a description of the bug and how your patch fixes
4353 this bug. Please try to include a way of demonstrating that the
4354 patch actually fixes something.
4356 * For new features: a description of the feature and your
4359 * A CHANGELOG entry as plaintext (separate from the patch)
4361 * For major contributions, your entry to the CREDITS file
4363 * When you add support for a new board, don't forget to add this
4364 board to the MAKEALL script, too.
4366 * If your patch adds new configuration options, don't forget to
4367 document these in the README file.
4369 * The patch itself. If you are using git (which is *strongly*
4370 recommended) you can easily generate the patch using the
4371 "git-format-patch". If you then use "git-send-email" to send it to
4372 the U-Boot mailing list, you will avoid most of the common problems
4373 with some other mail clients.
4375 If you cannot use git, use "diff -purN OLD NEW". If your version of
4376 diff does not support these options, then get the latest version of
4379 The current directory when running this command shall be the parent
4380 directory of the U-Boot source tree (i. e. please make sure that
4381 your patch includes sufficient directory information for the
4384 We prefer patches as plain text. MIME attachments are discouraged,
4385 and compressed attachments must not be used.
4387 * If one logical set of modifications affects or creates several
4388 files, all these changes shall be submitted in a SINGLE patch file.
4390 * Changesets that contain different, unrelated modifications shall be
4391 submitted as SEPARATE patches, one patch per changeset.
4396 * Before sending the patch, run the MAKEALL script on your patched
4397 source tree and make sure that no errors or warnings are reported
4398 for any of the boards.
4400 * Keep your modifications to the necessary minimum: A patch
4401 containing several unrelated changes or arbitrary reformats will be
4402 returned with a request to re-formatting / split it.
4404 * If you modify existing code, make sure that your new code does not
4405 add to the memory footprint of the code ;-) Small is beautiful!
4406 When adding new features, these should compile conditionally only
4407 (using #ifdef), and the resulting code with the new feature
4408 disabled must not need more memory than the old code without your
4411 * Remember that there is a size limit of 100 kB per message on the
4412 u-boot mailing list. Bigger patches will be moderated. If they are
4413 reasonable and not too big, they will be acknowledged. But patches
4414 bigger than the size limit should be avoided.
projects / karo-tx-uboot.git / blob