2 # (C) Copyright 2000 - 2009
3 # Wolfgang Denk, DENX Software Engineering, wd@denx.de.
5 # See file CREDITS for list of people who contributed to this
8 # This program is free software; you can redistribute it and/or
9 # modify it under the terms of the GNU General Public License as
10 # published by the Free Software Foundation; either version 2 of
11 # the License, or (at your option) any later version.
13 # This program is distributed in the hope that it will be useful,
14 # but WITHOUT ANY WARRANTY; without even the implied warranty of
15 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 # GNU General Public License for more details.
18 # You should have received a copy of the GNU General Public License
19 # along with this program; if not, write to the Free Software
20 # Foundation, Inc., 59 Temple Place, Suite 330, Boston,
27 This directory contains the source code for U-Boot, a boot loader for
28 Embedded boards based on PowerPC, ARM, MIPS and several other
29 processors, which can be installed in a boot ROM and used to
30 initialize and test the hardware or to download and run application
33 The development of U-Boot is closely related to Linux: some parts of
34 the source code originate in the Linux source tree, we have some
35 header files in common, and special provision has been made to
36 support booting of Linux images.
38 Some attention has been paid to make this software easily
39 configurable and extendable. For instance, all monitor commands are
40 implemented with the same call interface, so that it's very easy to
41 add new commands. Also, instead of permanently adding rarely used
42 code (for instance hardware test utilities) to the monitor, you can
43 load and run it dynamically.
49 In general, all boards for which a configuration option exists in the
50 Makefile have been tested to some extent and can be considered
51 "working". In fact, many of them are used in production systems.
53 In case of problems see the CHANGELOG and CREDITS files to find out
54 who contributed the specific port. The MAINTAINERS file lists board
61 In case you have questions about, problems with or contributions for
62 U-Boot you should send a message to the U-Boot mailing list at
63 <u-boot@lists.denx.de>. There is also an archive of previous traffic
64 on the mailing list - please search the archive before asking FAQ's.
65 Please see http://lists.denx.de/pipermail/u-boot and
66 http://dir.gmane.org/gmane.comp.boot-loaders.u-boot
69 Where to get source code:
70 =========================
72 The U-Boot source code is maintained in the git repository at
73 git://www.denx.de/git/u-boot.git ; you can browse it online at
74 http://www.denx.de/cgi-bin/gitweb.cgi?p=u-boot.git;a=summary
76 The "snapshot" links on this page allow you to download tarballs of
77 any version you might be interested in. Official releases are also
78 available for FTP download from the ftp://ftp.denx.de/pub/u-boot/
81 Pre-built (and tested) images are available from
82 ftp://ftp.denx.de/pub/u-boot/images/
88 - start from 8xxrom sources
89 - create PPCBoot project (http://sourceforge.net/projects/ppcboot)
91 - make it easier to add custom boards
92 - make it possible to add other [PowerPC] CPUs
93 - extend functions, especially:
94 * Provide extended interface to Linux boot loader
97 * PCMCIA / CompactFlash / ATA disk / SCSI ... boot
98 - create ARMBoot project (http://sourceforge.net/projects/armboot)
99 - add other CPU families (starting with ARM)
100 - create U-Boot project (http://sourceforge.net/projects/u-boot)
101 - current project page: see http://www.denx.de/wiki/U-Boot
107 The "official" name of this project is "Das U-Boot". The spelling
108 "U-Boot" shall be used in all written text (documentation, comments
109 in source files etc.). Example:
111 This is the README file for the U-Boot project.
113 File names etc. shall be based on the string "u-boot". Examples:
115 include/asm-ppc/u-boot.h
117 #include <asm/u-boot.h>
119 Variable names, preprocessor constants etc. shall be either based on
120 the string "u_boot" or on "U_BOOT". Example:
122 U_BOOT_VERSION u_boot_logo
123 IH_OS_U_BOOT u_boot_hush_start
129 Starting with the release in October 2008, the names of the releases
130 were changed from numerical release numbers without deeper meaning
131 into a time stamp based numbering. Regular releases are identified by
132 names consisting of the calendar year and month of the release date.
133 Additional fields (if present) indicate release candidates or bug fix
134 releases in "stable" maintenance trees.
137 U-Boot v2009.11 - Release November 2009
138 U-Boot v2009.11.1 - Release 1 in version November 2009 stable tree
139 U-Boot v2010.09-rc1 - Release candiate 1 for September 2010 release
145 /arch Architecture specific files
146 /arm Files generic to ARM architecture
147 /cpu CPU specific files
148 /arm720t Files specific to ARM 720 CPUs
149 /arm920t Files specific to ARM 920 CPUs
150 /at91rm9200 Files specific to Atmel AT91RM9200 CPU
151 /imx Files specific to Freescale MC9328 i.MX CPUs
152 /s3c24x0 Files specific to Samsung S3C24X0 CPUs
153 /arm925t Files specific to ARM 925 CPUs
154 /arm926ejs Files specific to ARM 926 CPUs
155 /arm1136 Files specific to ARM 1136 CPUs
156 /ixp Files specific to Intel XScale IXP CPUs
157 /pxa Files specific to Intel XScale PXA CPUs
158 /s3c44b0 Files specific to Samsung S3C44B0 CPUs
159 /sa1100 Files specific to Intel StrongARM SA1100 CPUs
160 /lib Architecture specific library files
161 /avr32 Files generic to AVR32 architecture
162 /cpu CPU specific files
163 /lib Architecture specific library files
164 /blackfin Files generic to Analog Devices Blackfin architecture
165 /cpu CPU specific files
166 /lib Architecture specific library files
167 /i386 Files generic to i386 architecture
168 /cpu CPU specific files
169 /lib Architecture specific library files
170 /m68k Files generic to m68k architecture
171 /cpu CPU specific files
172 /mcf52x2 Files specific to Freescale ColdFire MCF52x2 CPUs
173 /mcf5227x Files specific to Freescale ColdFire MCF5227x CPUs
174 /mcf532x Files specific to Freescale ColdFire MCF5329 CPUs
175 /mcf5445x Files specific to Freescale ColdFire MCF5445x CPUs
176 /mcf547x_8x Files specific to Freescale ColdFire MCF547x_8x CPUs
177 /lib Architecture specific library files
178 /microblaze Files generic to microblaze architecture
179 /cpu CPU specific files
180 /lib Architecture specific library files
181 /mips Files generic to MIPS architecture
182 /cpu CPU specific files
183 /lib Architecture specific library files
184 /nios2 Files generic to Altera NIOS2 architecture
185 /cpu CPU specific files
186 /lib Architecture specific library files
187 /powerpc Files generic to PowerPC architecture
188 /cpu CPU specific files
189 /74xx_7xx Files specific to Freescale MPC74xx and 7xx CPUs
190 /mpc5xx Files specific to Freescale MPC5xx CPUs
191 /mpc5xxx Files specific to Freescale MPC5xxx CPUs
192 /mpc8xx Files specific to Freescale MPC8xx CPUs
193 /mpc8220 Files specific to Freescale MPC8220 CPUs
194 /mpc824x Files specific to Freescale MPC824x CPUs
195 /mpc8260 Files specific to Freescale MPC8260 CPUs
196 /mpc85xx Files specific to Freescale MPC85xx CPUs
197 /ppc4xx Files specific to AMCC PowerPC 4xx CPUs
198 /lib Architecture specific library files
199 /sh Files generic to SH architecture
200 /cpu CPU specific files
201 /sh2 Files specific to sh2 CPUs
202 /sh3 Files specific to sh3 CPUs
203 /sh4 Files specific to sh4 CPUs
204 /lib Architecture specific library files
205 /sparc Files generic to SPARC architecture
206 /cpu CPU specific files
207 /leon2 Files specific to Gaisler LEON2 SPARC CPU
208 /leon3 Files specific to Gaisler LEON3 SPARC CPU
209 /lib Architecture specific library files
210 /api Machine/arch independent API for external apps
211 /board Board dependent files
212 /common Misc architecture independent functions
213 /disk Code for disk drive partition handling
214 /doc Documentation (don't expect too much)
215 /drivers Commonly used device drivers
216 /examples Example code for standalone applications, etc.
217 /fs Filesystem code (cramfs, ext2, jffs2, etc.)
218 /include Header Files
219 /lib Files generic to all architectures
220 /libfdt Library files to support flattened device trees
221 /lzma Library files to support LZMA decompression
222 /lzo Library files to support LZO decompression
224 /post Power On Self Test
225 /rtc Real Time Clock drivers
226 /tools Tools to build S-Record or U-Boot images, etc.
228 Software Configuration:
229 =======================
231 Configuration is usually done using C preprocessor defines; the
232 rationale behind that is to avoid dead code whenever possible.
234 There are two classes of configuration variables:
236 * Configuration _OPTIONS_:
237 These are selectable by the user and have names beginning with
240 * Configuration _SETTINGS_:
241 These depend on the hardware etc. and should not be meddled with if
242 you don't know what you're doing; they have names beginning with
245 Later we will add a configuration tool - probably similar to or even
246 identical to what's used for the Linux kernel. Right now, we have to
247 do the configuration by hand, which means creating some symbolic
248 links and editing some configuration files. We use the TQM8xxL boards
252 Selection of Processor Architecture and Board Type:
253 ---------------------------------------------------
255 For all supported boards there are ready-to-use default
256 configurations available; just type "make <board_name>_config".
258 Example: For a TQM823L module type:
263 For the Cogent platform, you need to specify the CPU type as well;
264 e.g. "make cogent_mpc8xx_config". And also configure the cogent
265 directory according to the instructions in cogent/README.
268 Configuration Options:
269 ----------------------
271 Configuration depends on the combination of board and CPU type; all
272 such information is kept in a configuration file
273 "include/configs/<board_name>.h".
275 Example: For a TQM823L module, all configuration settings are in
276 "include/configs/TQM823L.h".
279 Many of the options are named exactly as the corresponding Linux
280 kernel configuration options. The intention is to make it easier to
281 build a config tool - later.
284 The following options need to be configured:
286 - CPU Type: Define exactly one, e.g. CONFIG_MPC85XX.
288 - Board Type: Define exactly one, e.g. CONFIG_MPC8540ADS.
290 - CPU Daughterboard Type: (if CONFIG_ATSTK1000 is defined)
291 Define exactly one, e.g. CONFIG_ATSTK1002
293 - CPU Module Type: (if CONFIG_COGENT is defined)
294 Define exactly one of
296 --- FIXME --- not tested yet:
297 CONFIG_CMA286_60, CONFIG_CMA286_21, CONFIG_CMA286_60P,
298 CONFIG_CMA287_23, CONFIG_CMA287_50
300 - Motherboard Type: (if CONFIG_COGENT is defined)
301 Define exactly one of
302 CONFIG_CMA101, CONFIG_CMA102
304 - Motherboard I/O Modules: (if CONFIG_COGENT is defined)
305 Define one or more of
308 - Motherboard Options: (if CONFIG_CMA101 or CONFIG_CMA102 are defined)
309 Define one or more of
310 CONFIG_LCD_HEARTBEAT - update a character position on
311 the LCD display every second with
314 - Board flavour: (if CONFIG_MPC8260ADS is defined)
317 CONFIG_SYS_8260ADS - original MPC8260ADS
318 CONFIG_SYS_8266ADS - MPC8266ADS
319 CONFIG_SYS_PQ2FADS - PQ2FADS-ZU or PQ2FADS-VR
320 CONFIG_SYS_8272ADS - MPC8272ADS
322 - MPC824X Family Member (if CONFIG_MPC824X is defined)
323 Define exactly one of
324 CONFIG_MPC8240, CONFIG_MPC8245
326 - 8xx CPU Options: (if using an MPC8xx CPU)
327 CONFIG_8xx_GCLK_FREQ - deprecated: CPU clock if
328 get_gclk_freq() cannot work
329 e.g. if there is no 32KHz
330 reference PIT/RTC clock
331 CONFIG_8xx_OSCLK - PLL input clock (either EXTCLK
334 - 859/866/885 CPU options: (if using a MPC859 or MPC866 or MPC885 CPU):
335 CONFIG_SYS_8xx_CPUCLK_MIN
336 CONFIG_SYS_8xx_CPUCLK_MAX
337 CONFIG_8xx_CPUCLK_DEFAULT
338 See doc/README.MPC866
340 CONFIG_SYS_MEASURE_CPUCLK
342 Define this to measure the actual CPU clock instead
343 of relying on the correctness of the configured
344 values. Mostly useful for board bringup to make sure
345 the PLL is locked at the intended frequency. Note
346 that this requires a (stable) reference clock (32 kHz
347 RTC clock or CONFIG_SYS_8XX_XIN)
349 CONFIG_SYS_DELAYED_ICACHE
351 Define this option if you want to enable the
352 ICache only when Code runs from RAM.
354 - Intel Monahans options:
355 CONFIG_SYS_MONAHANS_RUN_MODE_OSC_RATIO
357 Defines the Monahans run mode to oscillator
358 ratio. Valid values are 8, 16, 24, 31. The core
359 frequency is this value multiplied by 13 MHz.
361 CONFIG_SYS_MONAHANS_TURBO_RUN_MODE_RATIO
363 Defines the Monahans turbo mode to oscillator
364 ratio. Valid values are 1 (default if undefined) and
365 2. The core frequency as calculated above is multiplied
368 - Linux Kernel Interface:
371 U-Boot stores all clock information in Hz
372 internally. For binary compatibility with older Linux
373 kernels (which expect the clocks passed in the
374 bd_info data to be in MHz) the environment variable
375 "clocks_in_mhz" can be defined so that U-Boot
376 converts clock data to MHZ before passing it to the
378 When CONFIG_CLOCKS_IN_MHZ is defined, a definition of
379 "clocks_in_mhz=1" is automatically included in the
382 CONFIG_MEMSIZE_IN_BYTES [relevant for MIPS only]
384 When transferring memsize parameter to linux, some versions
385 expect it to be in bytes, others in MB.
386 Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes.
390 New kernel versions are expecting firmware settings to be
391 passed using flattened device trees (based on open firmware
395 * New libfdt-based support
396 * Adds the "fdt" command
397 * The bootm command automatically updates the fdt
399 OF_CPU - The proper name of the cpus node (only required for
400 MPC512X and MPC5xxx based boards).
401 OF_SOC - The proper name of the soc node (only required for
402 MPC512X and MPC5xxx based boards).
403 OF_TBCLK - The timebase frequency.
404 OF_STDOUT_PATH - The path to the console device
406 boards with QUICC Engines require OF_QE to set UCC MAC
409 CONFIG_OF_BOARD_SETUP
411 Board code has addition modification that it wants to make
412 to the flat device tree before handing it off to the kernel
416 This define fills in the correct boot CPU in the boot
417 param header, the default value is zero if undefined.
421 U-Boot can detect if an IDE device is present or not.
422 If not, and this new config option is activated, U-Boot
423 removes the ATA node from the DTS before booting Linux,
424 so the Linux IDE driver does not probe the device and
425 crash. This is needed for buggy hardware (uc101) where
426 no pull down resistor is connected to the signal IDE5V_DD7.
428 - vxWorks boot parameters:
430 bootvx constructs a valid bootline using the following
431 environments variables: bootfile, ipaddr, serverip, hostname.
432 It loads the vxWorks image pointed bootfile.
434 CONFIG_SYS_VXWORKS_BOOT_DEVICE - The vxworks device name
435 CONFIG_SYS_VXWORKS_MAC_PTR - Ethernet 6 byte MA -address
436 CONFIG_SYS_VXWORKS_SERVERNAME - Name of the server
437 CONFIG_SYS_VXWORKS_BOOT_ADDR - Address of boot parameters
439 CONFIG_SYS_VXWORKS_ADD_PARAMS
441 Add it at the end of the bootline. E.g "u=username pw=secret"
443 Note: If a "bootargs" environment is defined, it will overwride
444 the defaults discussed just above.
449 Define this if you want support for Amba PrimeCell PL010 UARTs.
453 Define this if you want support for Amba PrimeCell PL011 UARTs.
457 If you have Amba PrimeCell PL011 UARTs, set this variable to
458 the clock speed of the UARTs.
462 If you have Amba PrimeCell PL010 or PL011 UARTs on your board,
463 define this to a list of base addresses for each (supported)
464 port. See e.g. include/configs/versatile.h
468 Depending on board, define exactly one serial port
469 (like CONFIG_8xx_CONS_SMC1, CONFIG_8xx_CONS_SMC2,
470 CONFIG_8xx_CONS_SCC1, ...), or switch off the serial
471 console by defining CONFIG_8xx_CONS_NONE
473 Note: if CONFIG_8xx_CONS_NONE is defined, the serial
474 port routines must be defined elsewhere
475 (i.e. serial_init(), serial_getc(), ...)
478 Enables console device for a color framebuffer. Needs following
479 defines (cf. smiLynxEM, i8042, board/eltec/bab7xx)
480 VIDEO_FB_LITTLE_ENDIAN graphic memory organisation
482 VIDEO_HW_RECTFILL graphic chip supports
485 VIDEO_HW_BITBLT graphic chip supports
486 bit-blit (cf. smiLynxEM)
487 VIDEO_VISIBLE_COLS visible pixel columns
489 VIDEO_VISIBLE_ROWS visible pixel rows
490 VIDEO_PIXEL_SIZE bytes per pixel
491 VIDEO_DATA_FORMAT graphic data format
492 (0-5, cf. cfb_console.c)
493 VIDEO_FB_ADRS framebuffer address
494 VIDEO_KBD_INIT_FCT keyboard int fct
495 (i.e. i8042_kbd_init())
496 VIDEO_TSTC_FCT test char fct
498 VIDEO_GETC_FCT get char fct
500 CONFIG_CONSOLE_CURSOR cursor drawing on/off
501 (requires blink timer
503 CONFIG_SYS_CONSOLE_BLINK_COUNT blink interval (cf. i8042.c)
504 CONFIG_CONSOLE_TIME display time/date info in
506 (requires CONFIG_CMD_DATE)
507 CONFIG_VIDEO_LOGO display Linux logo in
509 CONFIG_VIDEO_BMP_LOGO use bmp_logo.h instead of
510 linux_logo.h for logo.
511 Requires CONFIG_VIDEO_LOGO
512 CONFIG_CONSOLE_EXTRA_INFO
513 additional board info beside
516 When CONFIG_CFB_CONSOLE is defined, video console is
517 default i/o. Serial console can be forced with
518 environment 'console=serial'.
520 When CONFIG_SILENT_CONSOLE is defined, all console
521 messages (by U-Boot and Linux!) can be silenced with
522 the "silent" environment variable. See
523 doc/README.silent for more information.
526 CONFIG_BAUDRATE - in bps
527 Select one of the baudrates listed in
528 CONFIG_SYS_BAUDRATE_TABLE, see below.
529 CONFIG_SYS_BRGCLK_PRESCALE, baudrate prescale
531 - Console Rx buffer length
532 With CONFIG_SYS_SMC_RXBUFLEN it is possible to define
533 the maximum receive buffer length for the SMC.
534 This option is actual only for 82xx and 8xx possible.
535 If using CONFIG_SYS_SMC_RXBUFLEN also CONFIG_SYS_MAXIDLE
536 must be defined, to setup the maximum idle timeout for
539 - Boot Delay: CONFIG_BOOTDELAY - in seconds
540 Delay before automatically booting the default image;
541 set to -1 to disable autoboot.
543 See doc/README.autoboot for these options that
544 work with CONFIG_BOOTDELAY. None are required.
545 CONFIG_BOOT_RETRY_TIME
546 CONFIG_BOOT_RETRY_MIN
547 CONFIG_AUTOBOOT_KEYED
548 CONFIG_AUTOBOOT_PROMPT
549 CONFIG_AUTOBOOT_DELAY_STR
550 CONFIG_AUTOBOOT_STOP_STR
551 CONFIG_AUTOBOOT_DELAY_STR2
552 CONFIG_AUTOBOOT_STOP_STR2
553 CONFIG_ZERO_BOOTDELAY_CHECK
554 CONFIG_RESET_TO_RETRY
558 Only needed when CONFIG_BOOTDELAY is enabled;
559 define a command string that is automatically executed
560 when no character is read on the console interface
561 within "Boot Delay" after reset.
564 This can be used to pass arguments to the bootm
565 command. The value of CONFIG_BOOTARGS goes into the
566 environment value "bootargs".
568 CONFIG_RAMBOOT and CONFIG_NFSBOOT
569 The value of these goes into the environment as
570 "ramboot" and "nfsboot" respectively, and can be used
571 as a convenience, when switching between booting from
577 When this option is #defined, the existence of the
578 environment variable "preboot" will be checked
579 immediately before starting the CONFIG_BOOTDELAY
580 countdown and/or running the auto-boot command resp.
581 entering interactive mode.
583 This feature is especially useful when "preboot" is
584 automatically generated or modified. For an example
585 see the LWMON board specific code: here "preboot" is
586 modified when the user holds down a certain
587 combination of keys on the (special) keyboard when
590 - Serial Download Echo Mode:
592 If defined to 1, all characters received during a
593 serial download (using the "loads" command) are
594 echoed back. This might be needed by some terminal
595 emulations (like "cu"), but may as well just take
596 time on others. This setting #define's the initial
597 value of the "loads_echo" environment variable.
599 - Kgdb Serial Baudrate: (if CONFIG_CMD_KGDB is defined)
601 Select one of the baudrates listed in
602 CONFIG_SYS_BAUDRATE_TABLE, see below.
605 Monitor commands can be included or excluded
606 from the build by using the #include files
607 "config_cmd_all.h" and #undef'ing unwanted
608 commands, or using "config_cmd_default.h"
609 and augmenting with additional #define's
612 The default command configuration includes all commands
613 except those marked below with a "*".
615 CONFIG_CMD_ASKENV * ask for env variable
616 CONFIG_CMD_BDI bdinfo
617 CONFIG_CMD_BEDBUG * Include BedBug Debugger
618 CONFIG_CMD_BMP * BMP support
619 CONFIG_CMD_BSP * Board specific commands
620 CONFIG_CMD_BOOTD bootd
621 CONFIG_CMD_CACHE * icache, dcache
622 CONFIG_CMD_CONSOLE coninfo
623 CONFIG_CMD_DATE * support for RTC, date/time...
624 CONFIG_CMD_DHCP * DHCP support
625 CONFIG_CMD_DIAG * Diagnostics
626 CONFIG_CMD_DS4510 * ds4510 I2C gpio commands
627 CONFIG_CMD_DS4510_INFO * ds4510 I2C info command
628 CONFIG_CMD_DS4510_MEM * ds4510 I2C eeprom/sram commansd
629 CONFIG_CMD_DS4510_RST * ds4510 I2C rst command
630 CONFIG_CMD_DTT * Digital Therm and Thermostat
631 CONFIG_CMD_ECHO echo arguments
632 CONFIG_CMD_EDITENV edit env variable
633 CONFIG_CMD_EEPROM * EEPROM read/write support
634 CONFIG_CMD_ELF * bootelf, bootvx
635 CONFIG_CMD_SAVEENV saveenv
636 CONFIG_CMD_FDC * Floppy Disk Support
637 CONFIG_CMD_FAT * FAT partition support
638 CONFIG_CMD_FDOS * Dos diskette Support
639 CONFIG_CMD_FLASH flinfo, erase, protect
640 CONFIG_CMD_FPGA FPGA device initialization support
641 CONFIG_CMD_HWFLOW * RTS/CTS hw flow control
642 CONFIG_CMD_I2C * I2C serial bus support
643 CONFIG_CMD_IDE * IDE harddisk support
644 CONFIG_CMD_IMI iminfo
645 CONFIG_CMD_IMLS List all found images
646 CONFIG_CMD_IMMAP * IMMR dump support
647 CONFIG_CMD_IRQ * irqinfo
648 CONFIG_CMD_ITEST Integer/string test of 2 values
649 CONFIG_CMD_JFFS2 * JFFS2 Support
650 CONFIG_CMD_KGDB * kgdb
651 CONFIG_CMD_LOADB loadb
652 CONFIG_CMD_LOADS loads
653 CONFIG_CMD_MD5SUM print md5 message digest
654 (requires CONFIG_CMD_MEMORY and CONFIG_MD5)
655 CONFIG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base,
657 CONFIG_CMD_MISC Misc functions like sleep etc
658 CONFIG_CMD_MMC * MMC memory mapped support
659 CONFIG_CMD_MII * MII utility commands
660 CONFIG_CMD_MTDPARTS * MTD partition support
661 CONFIG_CMD_NAND * NAND support
662 CONFIG_CMD_NET bootp, tftpboot, rarpboot
663 CONFIG_CMD_PCA953X * PCA953x I2C gpio commands
664 CONFIG_CMD_PCA953X_INFO * PCA953x I2C gpio info command
665 CONFIG_CMD_PCI * pciinfo
666 CONFIG_CMD_PCMCIA * PCMCIA support
667 CONFIG_CMD_PING * send ICMP ECHO_REQUEST to network
669 CONFIG_CMD_PORTIO * Port I/O
670 CONFIG_CMD_REGINFO * Register dump
671 CONFIG_CMD_RUN run command in env variable
672 CONFIG_CMD_SAVES * save S record dump
673 CONFIG_CMD_SCSI * SCSI Support
674 CONFIG_CMD_SDRAM * print SDRAM configuration information
675 (requires CONFIG_CMD_I2C)
676 CONFIG_CMD_SETGETDCR Support for DCR Register access
678 CONFIG_CMD_SHA1 print sha1 memory digest
679 (requires CONFIG_CMD_MEMORY)
680 CONFIG_CMD_SOURCE "source" command Support
681 CONFIG_CMD_SPI * SPI serial bus support
682 CONFIG_CMD_USB * USB support
683 CONFIG_CMD_VFD * VFD support (TRAB)
684 CONFIG_CMD_CDP * Cisco Discover Protocol support
685 CONFIG_CMD_FSL * Microblaze FSL support
688 EXAMPLE: If you want all functions except of network
689 support you can write:
691 #include "config_cmd_all.h"
692 #undef CONFIG_CMD_NET
695 fdt (flattened device tree) command: CONFIG_OF_LIBFDT
697 Note: Don't enable the "icache" and "dcache" commands
698 (configuration option CONFIG_CMD_CACHE) unless you know
699 what you (and your U-Boot users) are doing. Data
700 cache cannot be enabled on systems like the 8xx or
701 8260 (where accesses to the IMMR region must be
702 uncached), and it cannot be disabled on all other
703 systems where we (mis-) use the data cache to hold an
704 initial stack and some data.
707 XXX - this list needs to get updated!
711 If this variable is defined, it enables watchdog
712 support. There must be support in the platform specific
713 code for a watchdog. For the 8xx and 8260 CPUs, the
714 SIU Watchdog feature is enabled in the SYPCR
718 CONFIG_VERSION_VARIABLE
719 If this variable is defined, an environment variable
720 named "ver" is created by U-Boot showing the U-Boot
721 version as printed by the "version" command.
722 This variable is readonly.
726 When CONFIG_CMD_DATE is selected, the type of the RTC
727 has to be selected, too. Define exactly one of the
730 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx
731 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC
732 CONFIG_RTC_MC13783 - use MC13783 RTC
733 CONFIG_RTC_MC146818 - use MC146818 RTC
734 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC
735 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC
736 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC
737 CONFIG_RTC_DS164x - use Dallas DS164x RTC
738 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC
739 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC
740 CONFIG_SYS_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337
742 Note that if the RTC uses I2C, then the I2C interface
743 must also be configured. See I2C Support, below.
746 CONFIG_PCA953X - use NXP's PCA953X series I2C GPIO
747 CONFIG_PCA953X_INFO - enable pca953x info command
749 The CONFIG_SYS_I2C_PCA953X_WIDTH option specifies a list of
750 chip-ngpio pairs that tell the PCA953X driver the number of
751 pins supported by a particular chip.
753 Note that if the GPIO device uses I2C, then the I2C interface
754 must also be configured. See I2C Support, below.
758 When CONFIG_TIMESTAMP is selected, the timestamp
759 (date and time) of an image is printed by image
760 commands like bootm or iminfo. This option is
761 automatically enabled when you select CONFIG_CMD_DATE .
764 CONFIG_MAC_PARTITION and/or CONFIG_DOS_PARTITION
765 and/or CONFIG_ISO_PARTITION and/or CONFIG_EFI_PARTITION
767 If IDE or SCSI support is enabled (CONFIG_CMD_IDE or
768 CONFIG_CMD_SCSI) you must configure support for at
769 least one partition type as well.
772 CONFIG_IDE_RESET_ROUTINE - this is defined in several
773 board configurations files but used nowhere!
775 CONFIG_IDE_RESET - is this is defined, IDE Reset will
776 be performed by calling the function
777 ide_set_reset(int reset)
778 which has to be defined in a board specific file
783 Set this to enable ATAPI support.
788 Set this to enable support for disks larger than 137GB
789 Also look at CONFIG_SYS_64BIT_LBA.
790 Whithout these , LBA48 support uses 32bit variables and will 'only'
791 support disks up to 2.1TB.
793 CONFIG_SYS_64BIT_LBA:
794 When enabled, makes the IDE subsystem use 64bit sector addresses.
798 At the moment only there is only support for the
799 SYM53C8XX SCSI controller; define
800 CONFIG_SCSI_SYM53C8XX to enable it.
802 CONFIG_SYS_SCSI_MAX_LUN [8], CONFIG_SYS_SCSI_MAX_SCSI_ID [7] and
803 CONFIG_SYS_SCSI_MAX_DEVICE [CONFIG_SYS_SCSI_MAX_SCSI_ID *
804 CONFIG_SYS_SCSI_MAX_LUN] can be adjusted to define the
805 maximum numbers of LUNs, SCSI ID's and target
807 CONFIG_SYS_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz)
809 - NETWORK Support (PCI):
811 Support for Intel 8254x gigabit chips.
813 CONFIG_E1000_FALLBACK_MAC
814 default MAC for empty EEPROM after production.
817 Support for Intel 82557/82559/82559ER chips.
818 Optional CONFIG_EEPRO100_SROM_WRITE enables EEPROM
819 write routine for first time initialisation.
822 Support for Digital 2114x chips.
823 Optional CONFIG_TULIP_SELECT_MEDIA for board specific
824 modem chip initialisation (KS8761/QS6611).
827 Support for National dp83815 chips.
830 Support for National dp8382[01] gigabit chips.
832 - NETWORK Support (other):
834 CONFIG_DRIVER_AT91EMAC
835 Support for AT91RM9200 EMAC.
838 Define this to use reduced MII inteface
840 CONFIG_DRIVER_AT91EMAC_QUIET
841 If this defined, the driver is quiet.
842 The driver doen't show link status messages.
844 CONFIG_DRIVER_LAN91C96
845 Support for SMSC's LAN91C96 chips.
848 Define this to hold the physical address
849 of the LAN91C96's I/O space
851 CONFIG_LAN91C96_USE_32_BIT
852 Define this to enable 32 bit addressing
854 CONFIG_DRIVER_SMC91111
855 Support for SMSC's LAN91C111 chip
858 Define this to hold the physical address
859 of the device (I/O space)
861 CONFIG_SMC_USE_32_BIT
862 Define this if data bus is 32 bits
864 CONFIG_SMC_USE_IOFUNCS
865 Define this to use i/o functions instead of macros
866 (some hardware wont work with macros)
869 Support for SMSC's LAN911x and LAN921x chips
872 Define this to hold the physical address
873 of the device (I/O space)
875 CONFIG_SMC911X_32_BIT
876 Define this if data bus is 32 bits
878 CONFIG_SMC911X_16_BIT
879 Define this if data bus is 16 bits. If your processor
880 automatically converts one 32 bit word to two 16 bit
881 words you may also try CONFIG_SMC911X_32_BIT.
884 At the moment only the UHCI host controller is
885 supported (PIP405, MIP405, MPC5200); define
886 CONFIG_USB_UHCI to enable it.
887 define CONFIG_USB_KEYBOARD to enable the USB Keyboard
888 and define CONFIG_USB_STORAGE to enable the USB
891 Supported are USB Keyboards and USB Floppy drives
893 MPC5200 USB requires additional defines:
895 for 528 MHz Clock: 0x0001bbbb
899 for differential drivers: 0x00001000
900 for single ended drivers: 0x00005000
901 for differential drivers on PSC3: 0x00000100
902 for single ended drivers on PSC3: 0x00004100
903 CONFIG_SYS_USB_EVENT_POLL
904 May be defined to allow interrupt polling
905 instead of using asynchronous interrupts
908 Define the below if you wish to use the USB console.
909 Once firmware is rebuilt from a serial console issue the
910 command "setenv stdin usbtty; setenv stdout usbtty" and
911 attach your USB cable. The Unix command "dmesg" should print
912 it has found a new device. The environment variable usbtty
913 can be set to gserial or cdc_acm to enable your device to
914 appear to a USB host as a Linux gserial device or a
915 Common Device Class Abstract Control Model serial device.
916 If you select usbtty = gserial you should be able to enumerate
918 # modprobe usbserial vendor=0xVendorID product=0xProductID
919 else if using cdc_acm, simply setting the environment
920 variable usbtty to be cdc_acm should suffice. The following
921 might be defined in YourBoardName.h
924 Define this to build a UDC device
927 Define this to have a tty type of device available to
928 talk to the UDC device
930 CONFIG_SYS_CONSOLE_IS_IN_ENV
931 Define this if you want stdin, stdout &/or stderr to
935 CONFIG_SYS_USB_EXTC_CLK 0xBLAH
936 Derive USB clock from external clock "blah"
937 - CONFIG_SYS_USB_EXTC_CLK 0x02
939 CONFIG_SYS_USB_BRG_CLK 0xBLAH
940 Derive USB clock from brgclk
941 - CONFIG_SYS_USB_BRG_CLK 0x04
943 If you have a USB-IF assigned VendorID then you may wish to
944 define your own vendor specific values either in BoardName.h
945 or directly in usbd_vendor_info.h. If you don't define
946 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME,
947 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot
948 should pretend to be a Linux device to it's target host.
950 CONFIG_USBD_MANUFACTURER
951 Define this string as the name of your company for
952 - CONFIG_USBD_MANUFACTURER "my company"
954 CONFIG_USBD_PRODUCT_NAME
955 Define this string as the name of your product
956 - CONFIG_USBD_PRODUCT_NAME "acme usb device"
959 Define this as your assigned Vendor ID from the USB
960 Implementors Forum. This *must* be a genuine Vendor ID
961 to avoid polluting the USB namespace.
962 - CONFIG_USBD_VENDORID 0xFFFF
964 CONFIG_USBD_PRODUCTID
965 Define this as the unique Product ID
967 - CONFIG_USBD_PRODUCTID 0xFFFF
971 The MMC controller on the Intel PXA is supported. To
972 enable this define CONFIG_MMC. The MMC can be
973 accessed from the boot prompt by mapping the device
974 to physical memory similar to flash. Command line is
975 enabled with CONFIG_CMD_MMC. The MMC driver also works with
976 the FAT fs. This is enabled with CONFIG_CMD_FAT.
978 - Journaling Flash filesystem support:
979 CONFIG_JFFS2_NAND, CONFIG_JFFS2_NAND_OFF, CONFIG_JFFS2_NAND_SIZE,
980 CONFIG_JFFS2_NAND_DEV
981 Define these for a default partition on a NAND device
983 CONFIG_SYS_JFFS2_FIRST_SECTOR,
984 CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS
985 Define these for a default partition on a NOR device
987 CONFIG_SYS_JFFS_CUSTOM_PART
988 Define this to create an own partition. You have to provide a
989 function struct part_info* jffs2_part_info(int part_num)
991 If you define only one JFFS2 partition you may also want to
992 #define CONFIG_SYS_JFFS_SINGLE_PART 1
993 to disable the command chpart. This is the default when you
994 have not defined a custom partition
999 Define this to enable standard (PC-Style) keyboard
1003 Standard PC keyboard driver with US (is default) and
1004 GERMAN key layout (switch via environment 'keymap=de') support.
1005 Export function i8042_kbd_init, i8042_tstc and i8042_getc
1006 for cfb_console. Supports cursor blinking.
1011 Define this to enable video support (for output to
1014 CONFIG_VIDEO_CT69000
1016 Enable Chips & Technologies 69000 Video chip
1018 CONFIG_VIDEO_SMI_LYNXEM
1019 Enable Silicon Motion SMI 712/710/810 Video chip. The
1020 video output is selected via environment 'videoout'
1021 (1 = LCD and 2 = CRT). If videoout is undefined, CRT is
1024 For the CT69000 and SMI_LYNXEM drivers, videomode is
1025 selected via environment 'videomode'. Two different ways
1027 - "videomode=num" 'num' is a standard LiLo mode numbers.
1028 Following standard modes are supported (* is default):
1030 Colors 640x480 800x600 1024x768 1152x864 1280x1024
1031 -------------+---------------------------------------------
1032 8 bits | 0x301* 0x303 0x305 0x161 0x307
1033 15 bits | 0x310 0x313 0x316 0x162 0x319
1034 16 bits | 0x311 0x314 0x317 0x163 0x31A
1035 24 bits | 0x312 0x315 0x318 ? 0x31B
1036 -------------+---------------------------------------------
1037 (i.e. setenv videomode 317; saveenv; reset;)
1039 - "videomode=bootargs" all the video parameters are parsed
1040 from the bootargs. (See drivers/video/videomodes.c)
1043 CONFIG_VIDEO_SED13806
1044 Enable Epson SED13806 driver. This driver supports 8bpp
1045 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP
1046 or CONFIG_VIDEO_SED13806_16BPP
1051 Define this to enable a custom keyboard support.
1052 This simply calls drv_keyboard_init() which must be
1053 defined in your board-specific files.
1054 The only board using this so far is RBC823.
1056 - LCD Support: CONFIG_LCD
1058 Define this to enable LCD support (for output to LCD
1059 display); also select one of the supported displays
1060 by defining one of these:
1064 HITACHI TX09D70VM1CCA, 3.5", 240x320.
1066 CONFIG_NEC_NL6448AC33:
1068 NEC NL6448AC33-18. Active, color, single scan.
1070 CONFIG_NEC_NL6448BC20
1072 NEC NL6448BC20-08. 6.5", 640x480.
1073 Active, color, single scan.
1075 CONFIG_NEC_NL6448BC33_54
1077 NEC NL6448BC33-54. 10.4", 640x480.
1078 Active, color, single scan.
1082 Sharp 320x240. Active, color, single scan.
1083 It isn't 16x9, and I am not sure what it is.
1085 CONFIG_SHARP_LQ64D341
1087 Sharp LQ64D341 display, 640x480.
1088 Active, color, single scan.
1092 HLD1045 display, 640x480.
1093 Active, color, single scan.
1097 Optrex CBL50840-2 NF-FW 99 22 M5
1099 Hitachi LMG6912RPFC-00T
1103 320x240. Black & white.
1105 Normally display is black on white background; define
1106 CONFIG_SYS_WHITE_ON_BLACK to get it inverted.
1108 - Splash Screen Support: CONFIG_SPLASH_SCREEN
1110 If this option is set, the environment is checked for
1111 a variable "splashimage". If found, the usual display
1112 of logo, copyright and system information on the LCD
1113 is suppressed and the BMP image at the address
1114 specified in "splashimage" is loaded instead. The
1115 console is redirected to the "nulldev", too. This
1116 allows for a "silent" boot where a splash screen is
1117 loaded very quickly after power-on.
1119 CONFIG_SPLASH_SCREEN_ALIGN
1121 If this option is set the splash image can be freely positioned
1122 on the screen. Environment variable "splashpos" specifies the
1123 position as "x,y". If a positive number is given it is used as
1124 number of pixel from left/top. If a negative number is given it
1125 is used as number of pixel from right/bottom. You can also
1126 specify 'm' for centering the image.
1129 setenv splashpos m,m
1130 => image at center of screen
1132 setenv splashpos 30,20
1133 => image at x = 30 and y = 20
1135 setenv splashpos -10,m
1136 => vertically centered image
1137 at x = dspWidth - bmpWidth - 9
1139 - Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP
1141 If this option is set, additionally to standard BMP
1142 images, gzipped BMP images can be displayed via the
1143 splashscreen support or the bmp command.
1145 - Run length encoded BMP image (RLE8) support: CONFIG_VIDEO_BMP_RLE8
1147 If this option is set, 8-bit RLE compressed BMP images
1148 can be displayed via the splashscreen support or the
1151 - Compression support:
1154 If this option is set, support for bzip2 compressed
1155 images is included. If not, only uncompressed and gzip
1156 compressed images are supported.
1158 NOTE: the bzip2 algorithm requires a lot of RAM, so
1159 the malloc area (as defined by CONFIG_SYS_MALLOC_LEN) should
1164 If this option is set, support for lzma compressed
1167 Note: The LZMA algorithm adds between 2 and 4KB of code and it
1168 requires an amount of dynamic memory that is given by the
1171 (1846 + 768 << (lc + lp)) * sizeof(uint16)
1173 Where lc and lp stand for, respectively, Literal context bits
1174 and Literal pos bits.
1176 This value is upper-bounded by 14MB in the worst case. Anyway,
1177 for a ~4MB large kernel image, we have lc=3 and lp=0 for a
1178 total amount of (1846 + 768 << (3 + 0)) * 2 = ~41KB... that is
1179 a very small buffer.
1181 Use the lzmainfo tool to determinate the lc and lp values and
1182 then calculate the amount of needed dynamic memory (ensuring
1183 the appropriate CONFIG_SYS_MALLOC_LEN value).
1188 The address of PHY on MII bus.
1190 CONFIG_PHY_CLOCK_FREQ (ppc4xx)
1192 The clock frequency of the MII bus
1196 If this option is set, support for speed/duplex
1197 detection of gigabit PHY is included.
1199 CONFIG_PHY_RESET_DELAY
1201 Some PHY like Intel LXT971A need extra delay after
1202 reset before any MII register access is possible.
1203 For such PHY, set this option to the usec delay
1204 required. (minimum 300usec for LXT971A)
1206 CONFIG_PHY_CMD_DELAY (ppc4xx)
1208 Some PHY like Intel LXT971A need extra delay after
1209 command issued before MII status register can be read
1219 Define a default value for Ethernet address to use
1220 for the respective Ethernet interface, in case this
1221 is not determined automatically.
1226 Define a default value for the IP address to use for
1227 the default Ethernet interface, in case this is not
1228 determined through e.g. bootp.
1230 - Server IP address:
1233 Defines a default value for the IP address of a TFTP
1234 server to contact when using the "tftboot" command.
1236 CONFIG_KEEP_SERVERADDR
1238 Keeps the server's MAC address, in the env 'serveraddr'
1239 for passing to bootargs (like Linux's netconsole option)
1241 - Multicast TFTP Mode:
1244 Defines whether you want to support multicast TFTP as per
1245 rfc-2090; for example to work with atftp. Lets lots of targets
1246 tftp down the same boot image concurrently. Note: the Ethernet
1247 driver in use must provide a function: mcast() to join/leave a
1250 CONFIG_BOOTP_RANDOM_DELAY
1251 - BOOTP Recovery Mode:
1252 CONFIG_BOOTP_RANDOM_DELAY
1254 If you have many targets in a network that try to
1255 boot using BOOTP, you may want to avoid that all
1256 systems send out BOOTP requests at precisely the same
1257 moment (which would happen for instance at recovery
1258 from a power failure, when all systems will try to
1259 boot, thus flooding the BOOTP server. Defining
1260 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
1261 inserted before sending out BOOTP requests. The
1262 following delays are inserted then:
1264 1st BOOTP request: delay 0 ... 1 sec
1265 2nd BOOTP request: delay 0 ... 2 sec
1266 3rd BOOTP request: delay 0 ... 4 sec
1268 BOOTP requests: delay 0 ... 8 sec
1270 - DHCP Advanced Options:
1271 You can fine tune the DHCP functionality by defining
1272 CONFIG_BOOTP_* symbols:
1274 CONFIG_BOOTP_SUBNETMASK
1275 CONFIG_BOOTP_GATEWAY
1276 CONFIG_BOOTP_HOSTNAME
1277 CONFIG_BOOTP_NISDOMAIN
1278 CONFIG_BOOTP_BOOTPATH
1279 CONFIG_BOOTP_BOOTFILESIZE
1282 CONFIG_BOOTP_SEND_HOSTNAME
1283 CONFIG_BOOTP_NTPSERVER
1284 CONFIG_BOOTP_TIMEOFFSET
1285 CONFIG_BOOTP_VENDOREX
1287 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip
1288 environment variable, not the BOOTP server.
1290 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS
1291 serverip from a DHCP server, it is possible that more
1292 than one DNS serverip is offered to the client.
1293 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS
1294 serverip will be stored in the additional environment
1295 variable "dnsip2". The first DNS serverip is always
1296 stored in the variable "dnsip", when CONFIG_BOOTP_DNS
1299 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable
1300 to do a dynamic update of a DNS server. To do this, they
1301 need the hostname of the DHCP requester.
1302 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content
1303 of the "hostname" environment variable is passed as
1304 option 12 to the DHCP server.
1306 CONFIG_BOOTP_DHCP_REQUEST_DELAY
1308 A 32bit value in microseconds for a delay between
1309 receiving a "DHCP Offer" and sending the "DHCP Request".
1310 This fixes a problem with certain DHCP servers that don't
1311 respond 100% of the time to a "DHCP request". E.g. On an
1312 AT91RM9200 processor running at 180MHz, this delay needed
1313 to be *at least* 15,000 usec before a Windows Server 2003
1314 DHCP server would reply 100% of the time. I recommend at
1315 least 50,000 usec to be safe. The alternative is to hope
1316 that one of the retries will be successful but note that
1317 the DHCP timeout and retry process takes a longer than
1321 CONFIG_CDP_DEVICE_ID
1323 The device id used in CDP trigger frames.
1325 CONFIG_CDP_DEVICE_ID_PREFIX
1327 A two character string which is prefixed to the MAC address
1332 A printf format string which contains the ascii name of
1333 the port. Normally is set to "eth%d" which sets
1334 eth0 for the first Ethernet, eth1 for the second etc.
1336 CONFIG_CDP_CAPABILITIES
1338 A 32bit integer which indicates the device capabilities;
1339 0x00000010 for a normal host which does not forwards.
1343 An ascii string containing the version of the software.
1347 An ascii string containing the name of the platform.
1351 A 32bit integer sent on the trigger.
1353 CONFIG_CDP_POWER_CONSUMPTION
1355 A 16bit integer containing the power consumption of the
1356 device in .1 of milliwatts.
1358 CONFIG_CDP_APPLIANCE_VLAN_TYPE
1360 A byte containing the id of the VLAN.
1362 - Status LED: CONFIG_STATUS_LED
1364 Several configurations allow to display the current
1365 status using a LED. For instance, the LED will blink
1366 fast while running U-Boot code, stop blinking as
1367 soon as a reply to a BOOTP request was received, and
1368 start blinking slow once the Linux kernel is running
1369 (supported by a status LED driver in the Linux
1370 kernel). Defining CONFIG_STATUS_LED enables this
1373 - CAN Support: CONFIG_CAN_DRIVER
1375 Defining CONFIG_CAN_DRIVER enables CAN driver support
1376 on those systems that support this (optional)
1377 feature, like the TQM8xxL modules.
1379 - I2C Support: CONFIG_HARD_I2C | CONFIG_SOFT_I2C
1381 These enable I2C serial bus commands. Defining either of
1382 (but not both of) CONFIG_HARD_I2C or CONFIG_SOFT_I2C will
1383 include the appropriate I2C driver for the selected CPU.
1385 This will allow you to use i2c commands at the u-boot
1386 command line (as long as you set CONFIG_CMD_I2C in
1387 CONFIG_COMMANDS) and communicate with i2c based realtime
1388 clock chips. See common/cmd_i2c.c for a description of the
1389 command line interface.
1391 CONFIG_HARD_I2C selects a hardware I2C controller.
1393 CONFIG_SOFT_I2C configures u-boot to use a software (aka
1394 bit-banging) driver instead of CPM or similar hardware
1397 There are several other quantities that must also be
1398 defined when you define CONFIG_HARD_I2C or CONFIG_SOFT_I2C.
1400 In both cases you will need to define CONFIG_SYS_I2C_SPEED
1401 to be the frequency (in Hz) at which you wish your i2c bus
1402 to run and CONFIG_SYS_I2C_SLAVE to be the address of this node (ie
1403 the CPU's i2c node address).
1405 Now, the u-boot i2c code for the mpc8xx
1406 (arch/powerpc/cpu/mpc8xx/i2c.c) sets the CPU up as a master node
1407 and so its address should therefore be cleared to 0 (See,
1408 eg, MPC823e User's Manual p.16-473). So, set
1409 CONFIG_SYS_I2C_SLAVE to 0.
1411 CONFIG_SYS_I2C_INIT_MPC5XXX
1413 When a board is reset during an i2c bus transfer
1414 chips might think that the current transfer is still
1415 in progress. Reset the slave devices by sending start
1416 commands until the slave device responds.
1418 That's all that's required for CONFIG_HARD_I2C.
1420 If you use the software i2c interface (CONFIG_SOFT_I2C)
1421 then the following macros need to be defined (examples are
1422 from include/configs/lwmon.h):
1426 (Optional). Any commands necessary to enable the I2C
1427 controller or configure ports.
1429 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
1433 (Only for MPC8260 CPU). The I/O port to use (the code
1434 assumes both bits are on the same port). Valid values
1435 are 0..3 for ports A..D.
1439 The code necessary to make the I2C data line active
1440 (driven). If the data line is open collector, this
1443 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
1447 The code necessary to make the I2C data line tri-stated
1448 (inactive). If the data line is open collector, this
1451 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
1455 Code that returns TRUE if the I2C data line is high,
1458 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
1462 If <bit> is TRUE, sets the I2C data line high. If it
1463 is FALSE, it clears it (low).
1465 eg: #define I2C_SDA(bit) \
1466 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
1467 else immr->im_cpm.cp_pbdat &= ~PB_SDA
1471 If <bit> is TRUE, sets the I2C clock line high. If it
1472 is FALSE, it clears it (low).
1474 eg: #define I2C_SCL(bit) \
1475 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
1476 else immr->im_cpm.cp_pbdat &= ~PB_SCL
1480 This delay is invoked four times per clock cycle so this
1481 controls the rate of data transfer. The data rate thus
1482 is 1 / (I2C_DELAY * 4). Often defined to be something
1485 #define I2C_DELAY udelay(2)
1487 CONFIG_SOFT_I2C_GPIO_SCL / CONFIG_SOFT_I2C_GPIO_SDA
1489 If your arch supports the generic GPIO framework (asm/gpio.h),
1490 then you may alternatively define the two GPIOs that are to be
1491 used as SCL / SDA. Any of the previous I2C_xxx macros will
1492 have GPIO-based defaults assigned to them as appropriate.
1494 You should define these to the GPIO value as given directly to
1495 the generic GPIO functions.
1497 CONFIG_SYS_I2C_INIT_BOARD
1499 When a board is reset during an i2c bus transfer
1500 chips might think that the current transfer is still
1501 in progress. On some boards it is possible to access
1502 the i2c SCLK line directly, either by using the
1503 processor pin as a GPIO or by having a second pin
1504 connected to the bus. If this option is defined a
1505 custom i2c_init_board() routine in boards/xxx/board.c
1506 is run early in the boot sequence.
1508 CONFIG_SYS_I2C_BOARD_LATE_INIT
1510 An alternative to CONFIG_SYS_I2C_INIT_BOARD. If this option is
1511 defined a custom i2c_board_late_init() routine in
1512 boards/xxx/board.c is run AFTER the operations in i2c_init()
1513 is completed. This callpoint can be used to unreset i2c bus
1514 using CPU i2c controller register accesses for CPUs whose i2c
1515 controller provide such a method. It is called at the end of
1516 i2c_init() to allow i2c_init operations to setup the i2c bus
1517 controller on the CPU (e.g. setting bus speed & slave address).
1519 CONFIG_I2CFAST (PPC405GP|PPC405EP only)
1521 This option enables configuration of bi_iic_fast[] flags
1522 in u-boot bd_info structure based on u-boot environment
1523 variable "i2cfast". (see also i2cfast)
1525 CONFIG_I2C_MULTI_BUS
1527 This option allows the use of multiple I2C buses, each of which
1528 must have a controller. At any point in time, only one bus is
1529 active. To switch to a different bus, use the 'i2c dev' command.
1530 Note that bus numbering is zero-based.
1532 CONFIG_SYS_I2C_NOPROBES
1534 This option specifies a list of I2C devices that will be skipped
1535 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS
1536 is set, specify a list of bus-device pairs. Otherwise, specify
1537 a 1D array of device addresses
1540 #undef CONFIG_I2C_MULTI_BUS
1541 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68}
1543 will skip addresses 0x50 and 0x68 on a board with one I2C bus
1545 #define CONFIG_I2C_MULTI_BUS
1546 #define CONFIG_SYS_I2C_MULTI_NOPROBES {{0,0x50},{0,0x68},{1,0x54}}
1548 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1
1550 CONFIG_SYS_SPD_BUS_NUM
1552 If defined, then this indicates the I2C bus number for DDR SPD.
1553 If not defined, then U-Boot assumes that SPD is on I2C bus 0.
1555 CONFIG_SYS_RTC_BUS_NUM
1557 If defined, then this indicates the I2C bus number for the RTC.
1558 If not defined, then U-Boot assumes that RTC is on I2C bus 0.
1560 CONFIG_SYS_DTT_BUS_NUM
1562 If defined, then this indicates the I2C bus number for the DTT.
1563 If not defined, then U-Boot assumes that DTT is on I2C bus 0.
1565 CONFIG_SYS_I2C_DTT_ADDR:
1567 If defined, specifies the I2C address of the DTT device.
1568 If not defined, then U-Boot uses predefined value for
1569 specified DTT device.
1573 Define this option if you want to use Freescale's I2C driver in
1574 drivers/i2c/fsl_i2c.c.
1578 Define this option if you have I2C devices reached over 1 .. n
1579 I2C Muxes like the pca9544a. This option addes a new I2C
1580 Command "i2c bus [muxtype:muxaddr:muxchannel]" which adds a
1581 new I2C Bus to the existing I2C Busses. If you select the
1582 new Bus with "i2c dev", u-bbot sends first the commandos for
1583 the muxes to activate this new "bus".
1585 CONFIG_I2C_MULTI_BUS must be also defined, to use this
1589 Adding a new I2C Bus reached over 2 pca9544a muxes
1590 The First mux with address 70 and channel 6
1591 The Second mux with address 71 and channel 4
1593 => i2c bus pca9544a:70:6:pca9544a:71:4
1595 Use the "i2c bus" command without parameter, to get a list
1596 of I2C Busses with muxes:
1599 Busses reached over muxes:
1601 reached over Mux(es):
1604 reached over Mux(es):
1609 If you now switch to the new I2C Bus 3 with "i2c dev 3"
1610 u-boot sends First the Commando to the mux@70 to enable
1611 channel 6, and then the Commando to the mux@71 to enable
1614 After that, you can use the "normal" i2c commands as
1615 usual, to communicate with your I2C devices behind
1618 This option is actually implemented for the bitbanging
1619 algorithm in common/soft_i2c.c and for the Hardware I2C
1620 Bus on the MPC8260. But it should be not so difficult
1621 to add this option to other architectures.
1623 CONFIG_SOFT_I2C_READ_REPEATED_START
1625 defining this will force the i2c_read() function in
1626 the soft_i2c driver to perform an I2C repeated start
1627 between writing the address pointer and reading the
1628 data. If this define is omitted the default behaviour
1629 of doing a stop-start sequence will be used. Most I2C
1630 devices can use either method, but some require one or
1633 - SPI Support: CONFIG_SPI
1635 Enables SPI driver (so far only tested with
1636 SPI EEPROM, also an instance works with Crystal A/D and
1637 D/As on the SACSng board)
1641 Enables extended (16-bit) SPI EEPROM addressing.
1642 (symmetrical to CONFIG_I2C_X)
1646 Enables a software (bit-bang) SPI driver rather than
1647 using hardware support. This is a general purpose
1648 driver that only requires three general I/O port pins
1649 (two outputs, one input) to function. If this is
1650 defined, the board configuration must define several
1651 SPI configuration items (port pins to use, etc). For
1652 an example, see include/configs/sacsng.h.
1656 Enables a hardware SPI driver for general-purpose reads
1657 and writes. As with CONFIG_SOFT_SPI, the board configuration
1658 must define a list of chip-select function pointers.
1659 Currently supported on some MPC8xxx processors. For an
1660 example, see include/configs/mpc8349emds.h.
1664 Enables the driver for the SPI controllers on i.MX and MXC
1665 SoCs. Currently only i.MX31 is supported.
1667 - FPGA Support: CONFIG_FPGA
1669 Enables FPGA subsystem.
1671 CONFIG_FPGA_<vendor>
1673 Enables support for specific chip vendors.
1676 CONFIG_FPGA_<family>
1678 Enables support for FPGA family.
1679 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX)
1683 Specify the number of FPGA devices to support.
1685 CONFIG_SYS_FPGA_PROG_FEEDBACK
1687 Enable printing of hash marks during FPGA configuration.
1689 CONFIG_SYS_FPGA_CHECK_BUSY
1691 Enable checks on FPGA configuration interface busy
1692 status by the configuration function. This option
1693 will require a board or device specific function to
1698 If defined, a function that provides delays in the FPGA
1699 configuration driver.
1701 CONFIG_SYS_FPGA_CHECK_CTRLC
1702 Allow Control-C to interrupt FPGA configuration
1704 CONFIG_SYS_FPGA_CHECK_ERROR
1706 Check for configuration errors during FPGA bitfile
1707 loading. For example, abort during Virtex II
1708 configuration if the INIT_B line goes low (which
1709 indicated a CRC error).
1711 CONFIG_SYS_FPGA_WAIT_INIT
1713 Maximum time to wait for the INIT_B line to deassert
1714 after PROB_B has been deasserted during a Virtex II
1715 FPGA configuration sequence. The default time is 500
1718 CONFIG_SYS_FPGA_WAIT_BUSY
1720 Maximum time to wait for BUSY to deassert during
1721 Virtex II FPGA configuration. The default is 5 ms.
1723 CONFIG_SYS_FPGA_WAIT_CONFIG
1725 Time to wait after FPGA configuration. The default is
1728 - Configuration Management:
1731 If defined, this string will be added to the U-Boot
1732 version information (U_BOOT_VERSION)
1734 - Vendor Parameter Protection:
1736 U-Boot considers the values of the environment
1737 variables "serial#" (Board Serial Number) and
1738 "ethaddr" (Ethernet Address) to be parameters that
1739 are set once by the board vendor / manufacturer, and
1740 protects these variables from casual modification by
1741 the user. Once set, these variables are read-only,
1742 and write or delete attempts are rejected. You can
1743 change this behaviour:
1745 If CONFIG_ENV_OVERWRITE is #defined in your config
1746 file, the write protection for vendor parameters is
1747 completely disabled. Anybody can change or delete
1750 Alternatively, if you #define _both_ CONFIG_ETHADDR
1751 _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
1752 Ethernet address is installed in the environment,
1753 which can be changed exactly ONCE by the user. [The
1754 serial# is unaffected by this, i. e. it remains
1760 Define this variable to enable the reservation of
1761 "protected RAM", i. e. RAM which is not overwritten
1762 by U-Boot. Define CONFIG_PRAM to hold the number of
1763 kB you want to reserve for pRAM. You can overwrite
1764 this default value by defining an environment
1765 variable "pram" to the number of kB you want to
1766 reserve. Note that the board info structure will
1767 still show the full amount of RAM. If pRAM is
1768 reserved, a new environment variable "mem" will
1769 automatically be defined to hold the amount of
1770 remaining RAM in a form that can be passed as boot
1771 argument to Linux, for instance like that:
1773 setenv bootargs ... mem=\${mem}
1776 This way you can tell Linux not to use this memory,
1777 either, which results in a memory region that will
1778 not be affected by reboots.
1780 *WARNING* If your board configuration uses automatic
1781 detection of the RAM size, you must make sure that
1782 this memory test is non-destructive. So far, the
1783 following board configurations are known to be
1786 ETX094, IVMS8, IVML24, SPD8xx, TQM8xxL,
1787 HERMES, IP860, RPXlite, LWMON, LANTEC,
1793 Define this variable to stop the system in case of a
1794 fatal error, so that you have to reset it manually.
1795 This is probably NOT a good idea for an embedded
1796 system where you want the system to reboot
1797 automatically as fast as possible, but it may be
1798 useful during development since you can try to debug
1799 the conditions that lead to the situation.
1801 CONFIG_NET_RETRY_COUNT
1803 This variable defines the number of retries for
1804 network operations like ARP, RARP, TFTP, or BOOTP
1805 before giving up the operation. If not defined, a
1806 default value of 5 is used.
1810 Timeout waiting for an ARP reply in milliseconds.
1812 - Command Interpreter:
1813 CONFIG_AUTO_COMPLETE
1815 Enable auto completion of commands using TAB.
1817 Note that this feature has NOT been implemented yet
1818 for the "hush" shell.
1821 CONFIG_SYS_HUSH_PARSER
1823 Define this variable to enable the "hush" shell (from
1824 Busybox) as command line interpreter, thus enabling
1825 powerful command line syntax like
1826 if...then...else...fi conditionals or `&&' and '||'
1827 constructs ("shell scripts").
1829 If undefined, you get the old, much simpler behaviour
1830 with a somewhat smaller memory footprint.
1833 CONFIG_SYS_PROMPT_HUSH_PS2
1835 This defines the secondary prompt string, which is
1836 printed when the command interpreter needs more input
1837 to complete a command. Usually "> ".
1841 In the current implementation, the local variables
1842 space and global environment variables space are
1843 separated. Local variables are those you define by
1844 simply typing `name=value'. To access a local
1845 variable later on, you have write `$name' or
1846 `${name}'; to execute the contents of a variable
1847 directly type `$name' at the command prompt.
1849 Global environment variables are those you use
1850 setenv/printenv to work with. To run a command stored
1851 in such a variable, you need to use the run command,
1852 and you must not use the '$' sign to access them.
1854 To store commands and special characters in a
1855 variable, please use double quotation marks
1856 surrounding the whole text of the variable, instead
1857 of the backslashes before semicolons and special
1860 - Commandline Editing and History:
1861 CONFIG_CMDLINE_EDITING
1863 Enable editing and History functions for interactive
1864 commandline input operations
1866 - Default Environment:
1867 CONFIG_EXTRA_ENV_SETTINGS
1869 Define this to contain any number of null terminated
1870 strings (variable = value pairs) that will be part of
1871 the default environment compiled into the boot image.
1873 For example, place something like this in your
1874 board's config file:
1876 #define CONFIG_EXTRA_ENV_SETTINGS \
1880 Warning: This method is based on knowledge about the
1881 internal format how the environment is stored by the
1882 U-Boot code. This is NOT an official, exported
1883 interface! Although it is unlikely that this format
1884 will change soon, there is no guarantee either.
1885 You better know what you are doing here.
1887 Note: overly (ab)use of the default environment is
1888 discouraged. Make sure to check other ways to preset
1889 the environment like the "source" command or the
1892 - DataFlash Support:
1893 CONFIG_HAS_DATAFLASH
1895 Defining this option enables DataFlash features and
1896 allows to read/write in Dataflash via the standard
1899 - SystemACE Support:
1902 Adding this option adds support for Xilinx SystemACE
1903 chips attached via some sort of local bus. The address
1904 of the chip must also be defined in the
1905 CONFIG_SYS_SYSTEMACE_BASE macro. For example:
1907 #define CONFIG_SYSTEMACE
1908 #define CONFIG_SYS_SYSTEMACE_BASE 0xf0000000
1910 When SystemACE support is added, the "ace" device type
1911 becomes available to the fat commands, i.e. fatls.
1913 - TFTP Fixed UDP Port:
1916 If this is defined, the environment variable tftpsrcp
1917 is used to supply the TFTP UDP source port value.
1918 If tftpsrcp isn't defined, the normal pseudo-random port
1919 number generator is used.
1921 Also, the environment variable tftpdstp is used to supply
1922 the TFTP UDP destination port value. If tftpdstp isn't
1923 defined, the normal port 69 is used.
1925 The purpose for tftpsrcp is to allow a TFTP server to
1926 blindly start the TFTP transfer using the pre-configured
1927 target IP address and UDP port. This has the effect of
1928 "punching through" the (Windows XP) firewall, allowing
1929 the remainder of the TFTP transfer to proceed normally.
1930 A better solution is to properly configure the firewall,
1931 but sometimes that is not allowed.
1933 - Show boot progress:
1934 CONFIG_SHOW_BOOT_PROGRESS
1936 Defining this option allows to add some board-
1937 specific code (calling a user-provided function
1938 "show_boot_progress(int)") that enables you to show
1939 the system's boot progress on some display (for
1940 example, some LED's) on your board. At the moment,
1941 the following checkpoints are implemented:
1943 Legacy uImage format:
1946 1 common/cmd_bootm.c before attempting to boot an image
1947 -1 common/cmd_bootm.c Image header has bad magic number
1948 2 common/cmd_bootm.c Image header has correct magic number
1949 -2 common/cmd_bootm.c Image header has bad checksum
1950 3 common/cmd_bootm.c Image header has correct checksum
1951 -3 common/cmd_bootm.c Image data has bad checksum
1952 4 common/cmd_bootm.c Image data has correct checksum
1953 -4 common/cmd_bootm.c Image is for unsupported architecture
1954 5 common/cmd_bootm.c Architecture check OK
1955 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi)
1956 6 common/cmd_bootm.c Image Type check OK
1957 -6 common/cmd_bootm.c gunzip uncompression error
1958 -7 common/cmd_bootm.c Unimplemented compression type
1959 7 common/cmd_bootm.c Uncompression OK
1960 8 common/cmd_bootm.c No uncompress/copy overwrite error
1961 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX)
1963 9 common/image.c Start initial ramdisk verification
1964 -10 common/image.c Ramdisk header has bad magic number
1965 -11 common/image.c Ramdisk header has bad checksum
1966 10 common/image.c Ramdisk header is OK
1967 -12 common/image.c Ramdisk data has bad checksum
1968 11 common/image.c Ramdisk data has correct checksum
1969 12 common/image.c Ramdisk verification complete, start loading
1970 -13 common/image.c Wrong Image Type (not PPC Linux ramdisk)
1971 13 common/image.c Start multifile image verification
1972 14 common/image.c No initial ramdisk, no multifile, continue.
1974 15 arch/<arch>/lib/bootm.c All preparation done, transferring control to OS
1976 -30 arch/powerpc/lib/board.c Fatal error, hang the system
1977 -31 post/post.c POST test failed, detected by post_output_backlog()
1978 -32 post/post.c POST test failed, detected by post_run_single()
1980 34 common/cmd_doc.c before loading a Image from a DOC device
1981 -35 common/cmd_doc.c Bad usage of "doc" command
1982 35 common/cmd_doc.c correct usage of "doc" command
1983 -36 common/cmd_doc.c No boot device
1984 36 common/cmd_doc.c correct boot device
1985 -37 common/cmd_doc.c Unknown Chip ID on boot device
1986 37 common/cmd_doc.c correct chip ID found, device available
1987 -38 common/cmd_doc.c Read Error on boot device
1988 38 common/cmd_doc.c reading Image header from DOC device OK
1989 -39 common/cmd_doc.c Image header has bad magic number
1990 39 common/cmd_doc.c Image header has correct magic number
1991 -40 common/cmd_doc.c Error reading Image from DOC device
1992 40 common/cmd_doc.c Image header has correct magic number
1993 41 common/cmd_ide.c before loading a Image from a IDE device
1994 -42 common/cmd_ide.c Bad usage of "ide" command
1995 42 common/cmd_ide.c correct usage of "ide" command
1996 -43 common/cmd_ide.c No boot device
1997 43 common/cmd_ide.c boot device found
1998 -44 common/cmd_ide.c Device not available
1999 44 common/cmd_ide.c Device available
2000 -45 common/cmd_ide.c wrong partition selected
2001 45 common/cmd_ide.c partition selected
2002 -46 common/cmd_ide.c Unknown partition table
2003 46 common/cmd_ide.c valid partition table found
2004 -47 common/cmd_ide.c Invalid partition type
2005 47 common/cmd_ide.c correct partition type
2006 -48 common/cmd_ide.c Error reading Image Header on boot device
2007 48 common/cmd_ide.c reading Image Header from IDE device OK
2008 -49 common/cmd_ide.c Image header has bad magic number
2009 49 common/cmd_ide.c Image header has correct magic number
2010 -50 common/cmd_ide.c Image header has bad checksum
2011 50 common/cmd_ide.c Image header has correct checksum
2012 -51 common/cmd_ide.c Error reading Image from IDE device
2013 51 common/cmd_ide.c reading Image from IDE device OK
2014 52 common/cmd_nand.c before loading a Image from a NAND device
2015 -53 common/cmd_nand.c Bad usage of "nand" command
2016 53 common/cmd_nand.c correct usage of "nand" command
2017 -54 common/cmd_nand.c No boot device
2018 54 common/cmd_nand.c boot device found
2019 -55 common/cmd_nand.c Unknown Chip ID on boot device
2020 55 common/cmd_nand.c correct chip ID found, device available
2021 -56 common/cmd_nand.c Error reading Image Header on boot device
2022 56 common/cmd_nand.c reading Image Header from NAND device OK
2023 -57 common/cmd_nand.c Image header has bad magic number
2024 57 common/cmd_nand.c Image header has correct magic number
2025 -58 common/cmd_nand.c Error reading Image from NAND device
2026 58 common/cmd_nand.c reading Image from NAND device OK
2028 -60 common/env_common.c Environment has a bad CRC, using default
2030 64 net/eth.c starting with Ethernet configuration.
2031 -64 net/eth.c no Ethernet found.
2032 65 net/eth.c Ethernet found.
2034 -80 common/cmd_net.c usage wrong
2035 80 common/cmd_net.c before calling NetLoop()
2036 -81 common/cmd_net.c some error in NetLoop() occurred
2037 81 common/cmd_net.c NetLoop() back without error
2038 -82 common/cmd_net.c size == 0 (File with size 0 loaded)
2039 82 common/cmd_net.c trying automatic boot
2040 83 common/cmd_net.c running "source" command
2041 -83 common/cmd_net.c some error in automatic boot or "source" command
2042 84 common/cmd_net.c end without errors
2047 100 common/cmd_bootm.c Kernel FIT Image has correct format
2048 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format
2049 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration
2050 -101 common/cmd_bootm.c Can't get configuration for kernel subimage
2051 102 common/cmd_bootm.c Kernel unit name specified
2052 -103 common/cmd_bootm.c Can't get kernel subimage node offset
2053 103 common/cmd_bootm.c Found configuration node
2054 104 common/cmd_bootm.c Got kernel subimage node offset
2055 -104 common/cmd_bootm.c Kernel subimage hash verification failed
2056 105 common/cmd_bootm.c Kernel subimage hash verification OK
2057 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture
2058 106 common/cmd_bootm.c Architecture check OK
2059 -106 common/cmd_bootm.c Kernel subimage has wrong type
2060 107 common/cmd_bootm.c Kernel subimage type OK
2061 -107 common/cmd_bootm.c Can't get kernel subimage data/size
2062 108 common/cmd_bootm.c Got kernel subimage data/size
2063 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT)
2064 -109 common/cmd_bootm.c Can't get kernel subimage type
2065 -110 common/cmd_bootm.c Can't get kernel subimage comp
2066 -111 common/cmd_bootm.c Can't get kernel subimage os
2067 -112 common/cmd_bootm.c Can't get kernel subimage load address
2068 -113 common/cmd_bootm.c Image uncompress/copy overwrite error
2070 120 common/image.c Start initial ramdisk verification
2071 -120 common/image.c Ramdisk FIT image has incorrect format
2072 121 common/image.c Ramdisk FIT image has correct format
2073 122 common/image.c No ramdisk subimage unit name, using configuration
2074 -122 common/image.c Can't get configuration for ramdisk subimage
2075 123 common/image.c Ramdisk unit name specified
2076 -124 common/image.c Can't get ramdisk subimage node offset
2077 125 common/image.c Got ramdisk subimage node offset
2078 -125 common/image.c Ramdisk subimage hash verification failed
2079 126 common/image.c Ramdisk subimage hash verification OK
2080 -126 common/image.c Ramdisk subimage for unsupported architecture
2081 127 common/image.c Architecture check OK
2082 -127 common/image.c Can't get ramdisk subimage data/size
2083 128 common/image.c Got ramdisk subimage data/size
2084 129 common/image.c Can't get ramdisk load address
2085 -129 common/image.c Got ramdisk load address
2087 -130 common/cmd_doc.c Incorrect FIT image format
2088 131 common/cmd_doc.c FIT image format OK
2090 -140 common/cmd_ide.c Incorrect FIT image format
2091 141 common/cmd_ide.c FIT image format OK
2093 -150 common/cmd_nand.c Incorrect FIT image format
2094 151 common/cmd_nand.c FIT image format OK
2096 - Automatic software updates via TFTP server
2098 CONFIG_UPDATE_TFTP_CNT_MAX
2099 CONFIG_UPDATE_TFTP_MSEC_MAX
2101 These options enable and control the auto-update feature;
2102 for a more detailed description refer to doc/README.update.
2104 - MTD Support (mtdparts command, UBI support)
2107 Adds the MTD device infrastructure from the Linux kernel.
2108 Needed for mtdparts command support.
2110 CONFIG_MTD_PARTITIONS
2112 Adds the MTD partitioning infrastructure from the Linux
2113 kernel. Needed for UBI support.
2119 [so far only for SMDK2400 and TRAB boards]
2121 - Modem support enable:
2122 CONFIG_MODEM_SUPPORT
2124 - RTS/CTS Flow control enable:
2127 - Modem debug support:
2128 CONFIG_MODEM_SUPPORT_DEBUG
2130 Enables debugging stuff (char screen[1024], dbg())
2131 for modem support. Useful only with BDI2000.
2133 - Interrupt support (PPC):
2135 There are common interrupt_init() and timer_interrupt()
2136 for all PPC archs. interrupt_init() calls interrupt_init_cpu()
2137 for CPU specific initialization. interrupt_init_cpu()
2138 should set decrementer_count to appropriate value. If
2139 CPU resets decrementer automatically after interrupt
2140 (ppc4xx) it should set decrementer_count to zero.
2141 timer_interrupt() calls timer_interrupt_cpu() for CPU
2142 specific handling. If board has watchdog / status_led
2143 / other_activity_monitor it works automatically from
2144 general timer_interrupt().
2148 In the target system modem support is enabled when a
2149 specific key (key combination) is pressed during
2150 power-on. Otherwise U-Boot will boot normally
2151 (autoboot). The key_pressed() function is called from
2152 board_init(). Currently key_pressed() is a dummy
2153 function, returning 1 and thus enabling modem
2156 If there are no modem init strings in the
2157 environment, U-Boot proceed to autoboot; the
2158 previous output (banner, info printfs) will be
2161 See also: doc/README.Modem
2164 Configuration Settings:
2165 -----------------------
2167 - CONFIG_SYS_LONGHELP: Defined when you want long help messages included;
2168 undefine this when you're short of memory.
2170 - CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default
2171 width of the commands listed in the 'help' command output.
2173 - CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to
2174 prompt for user input.
2176 - CONFIG_SYS_CBSIZE: Buffer size for input from the Console
2178 - CONFIG_SYS_PBSIZE: Buffer size for Console output
2180 - CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands
2182 - CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to
2183 the application (usually a Linux kernel) when it is
2186 - CONFIG_SYS_BAUDRATE_TABLE:
2187 List of legal baudrate settings for this board.
2189 - CONFIG_SYS_CONSOLE_INFO_QUIET
2190 Suppress display of console information at boot.
2192 - CONFIG_SYS_CONSOLE_IS_IN_ENV
2193 If the board specific function
2194 extern int overwrite_console (void);
2195 returns 1, the stdin, stderr and stdout are switched to the
2196 serial port, else the settings in the environment are used.
2198 - CONFIG_SYS_CONSOLE_OVERWRITE_ROUTINE
2199 Enable the call to overwrite_console().
2201 - CONFIG_SYS_CONSOLE_ENV_OVERWRITE
2202 Enable overwrite of previous console environment settings.
2204 - CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END:
2205 Begin and End addresses of the area used by the
2208 - CONFIG_SYS_ALT_MEMTEST:
2209 Enable an alternate, more extensive memory test.
2211 - CONFIG_SYS_MEMTEST_SCRATCH:
2212 Scratch address used by the alternate memory test
2213 You only need to set this if address zero isn't writeable
2215 - CONFIG_SYS_MEM_TOP_HIDE (PPC only):
2216 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header,
2217 this specified memory area will get subtracted from the top
2218 (end) of RAM and won't get "touched" at all by U-Boot. By
2219 fixing up gd->ram_size the Linux kernel should gets passed
2220 the now "corrected" memory size and won't touch it either.
2221 This should work for arch/ppc and arch/powerpc. Only Linux
2222 board ports in arch/powerpc with bootwrapper support that
2223 recalculate the memory size from the SDRAM controller setup
2224 will have to get fixed in Linux additionally.
2226 This option can be used as a workaround for the 440EPx/GRx
2227 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't
2230 WARNING: Please make sure that this value is a multiple of
2231 the Linux page size (normally 4k). If this is not the case,
2232 then the end address of the Linux memory will be located at a
2233 non page size aligned address and this could cause major
2236 - CONFIG_SYS_TFTP_LOADADDR:
2237 Default load address for network file downloads
2239 - CONFIG_SYS_LOADS_BAUD_CHANGE:
2240 Enable temporary baudrate change while serial download
2242 - CONFIG_SYS_SDRAM_BASE:
2243 Physical start address of SDRAM. _Must_ be 0 here.
2245 - CONFIG_SYS_MBIO_BASE:
2246 Physical start address of Motherboard I/O (if using a
2249 - CONFIG_SYS_FLASH_BASE:
2250 Physical start address of Flash memory.
2252 - CONFIG_SYS_MONITOR_BASE:
2253 Physical start address of boot monitor code (set by
2254 make config files to be same as the text base address
2255 (CONFIG_SYS_TEXT_BASE) used when linking) - same as
2256 CONFIG_SYS_FLASH_BASE when booting from flash.
2258 - CONFIG_SYS_MONITOR_LEN:
2259 Size of memory reserved for monitor code, used to
2260 determine _at_compile_time_ (!) if the environment is
2261 embedded within the U-Boot image, or in a separate
2264 - CONFIG_SYS_MALLOC_LEN:
2265 Size of DRAM reserved for malloc() use.
2267 - CONFIG_SYS_BOOTM_LEN:
2268 Normally compressed uImages are limited to an
2269 uncompressed size of 8 MBytes. If this is not enough,
2270 you can define CONFIG_SYS_BOOTM_LEN in your board config file
2271 to adjust this setting to your needs.
2273 - CONFIG_SYS_BOOTMAPSZ:
2274 Maximum size of memory mapped by the startup code of
2275 the Linux kernel; all data that must be processed by
2276 the Linux kernel (bd_info, boot arguments, FDT blob if
2277 used) must be put below this limit, unless "bootm_low"
2278 enviroment variable is defined and non-zero. In such case
2279 all data for the Linux kernel must be between "bootm_low"
2280 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ.
2282 - CONFIG_SYS_BOOT_RAMDISK_HIGH:
2283 Enable initrd_high functionality. If defined then the
2284 initrd_high feature is enabled and the bootm ramdisk subcommand
2287 - CONFIG_SYS_BOOT_GET_CMDLINE:
2288 Enables allocating and saving kernel cmdline in space between
2289 "bootm_low" and "bootm_low" + BOOTMAPSZ.
2291 - CONFIG_SYS_BOOT_GET_KBD:
2292 Enables allocating and saving a kernel copy of the bd_info in
2293 space between "bootm_low" and "bootm_low" + BOOTMAPSZ.
2295 - CONFIG_SYS_MAX_FLASH_BANKS:
2296 Max number of Flash memory banks
2298 - CONFIG_SYS_MAX_FLASH_SECT:
2299 Max number of sectors on a Flash chip
2301 - CONFIG_SYS_FLASH_ERASE_TOUT:
2302 Timeout for Flash erase operations (in ms)
2304 - CONFIG_SYS_FLASH_WRITE_TOUT:
2305 Timeout for Flash write operations (in ms)
2307 - CONFIG_SYS_FLASH_LOCK_TOUT
2308 Timeout for Flash set sector lock bit operation (in ms)
2310 - CONFIG_SYS_FLASH_UNLOCK_TOUT
2311 Timeout for Flash clear lock bits operation (in ms)
2313 - CONFIG_SYS_FLASH_PROTECTION
2314 If defined, hardware flash sectors protection is used
2315 instead of U-Boot software protection.
2317 - CONFIG_SYS_DIRECT_FLASH_TFTP:
2319 Enable TFTP transfers directly to flash memory;
2320 without this option such a download has to be
2321 performed in two steps: (1) download to RAM, and (2)
2322 copy from RAM to flash.
2324 The two-step approach is usually more reliable, since
2325 you can check if the download worked before you erase
2326 the flash, but in some situations (when system RAM is
2327 too limited to allow for a temporary copy of the
2328 downloaded image) this option may be very useful.
2330 - CONFIG_SYS_FLASH_CFI:
2331 Define if the flash driver uses extra elements in the
2332 common flash structure for storing flash geometry.
2334 - CONFIG_FLASH_CFI_DRIVER
2335 This option also enables the building of the cfi_flash driver
2336 in the drivers directory
2338 - CONFIG_FLASH_CFI_MTD
2339 This option enables the building of the cfi_mtd driver
2340 in the drivers directory. The driver exports CFI flash
2343 - CONFIG_SYS_FLASH_USE_BUFFER_WRITE
2344 Use buffered writes to flash.
2346 - CONFIG_FLASH_SPANSION_S29WS_N
2347 s29ws-n MirrorBit flash has non-standard addresses for buffered
2350 - CONFIG_SYS_FLASH_QUIET_TEST
2351 If this option is defined, the common CFI flash doesn't
2352 print it's warning upon not recognized FLASH banks. This
2353 is useful, if some of the configured banks are only
2354 optionally available.
2356 - CONFIG_FLASH_SHOW_PROGRESS
2357 If defined (must be an integer), print out countdown
2358 digits and dots. Recommended value: 45 (9..1) for 80
2359 column displays, 15 (3..1) for 40 column displays.
2361 - CONFIG_SYS_RX_ETH_BUFFER:
2362 Defines the number of Ethernet receive buffers. On some
2363 Ethernet controllers it is recommended to set this value
2364 to 8 or even higher (EEPRO100 or 405 EMAC), since all
2365 buffers can be full shortly after enabling the interface
2366 on high Ethernet traffic.
2367 Defaults to 4 if not defined.
2369 - CONFIG_ENV_MAX_ENTRIES
2371 Maximum number of entries in the hash table that is used
2372 internally to store the environment settings. The default
2373 setting is supposed to be generous and should work in most
2374 cases. This setting can be used to tune behaviour; see
2375 lib/hashtable.c for details.
2377 The following definitions that deal with the placement and management
2378 of environment data (variable area); in general, we support the
2379 following configurations:
2381 - CONFIG_ENV_IS_IN_FLASH:
2383 Define this if the environment is in flash memory.
2385 a) The environment occupies one whole flash sector, which is
2386 "embedded" in the text segment with the U-Boot code. This
2387 happens usually with "bottom boot sector" or "top boot
2388 sector" type flash chips, which have several smaller
2389 sectors at the start or the end. For instance, such a
2390 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In
2391 such a case you would place the environment in one of the
2392 4 kB sectors - with U-Boot code before and after it. With
2393 "top boot sector" type flash chips, you would put the
2394 environment in one of the last sectors, leaving a gap
2395 between U-Boot and the environment.
2397 - CONFIG_ENV_OFFSET:
2399 Offset of environment data (variable area) to the
2400 beginning of flash memory; for instance, with bottom boot
2401 type flash chips the second sector can be used: the offset
2402 for this sector is given here.
2404 CONFIG_ENV_OFFSET is used relative to CONFIG_SYS_FLASH_BASE.
2408 This is just another way to specify the start address of
2409 the flash sector containing the environment (instead of
2412 - CONFIG_ENV_SECT_SIZE:
2414 Size of the sector containing the environment.
2417 b) Sometimes flash chips have few, equal sized, BIG sectors.
2418 In such a case you don't want to spend a whole sector for
2423 If you use this in combination with CONFIG_ENV_IS_IN_FLASH
2424 and CONFIG_ENV_SECT_SIZE, you can specify to use only a part
2425 of this flash sector for the environment. This saves
2426 memory for the RAM copy of the environment.
2428 It may also save flash memory if you decide to use this
2429 when your environment is "embedded" within U-Boot code,
2430 since then the remainder of the flash sector could be used
2431 for U-Boot code. It should be pointed out that this is
2432 STRONGLY DISCOURAGED from a robustness point of view:
2433 updating the environment in flash makes it always
2434 necessary to erase the WHOLE sector. If something goes
2435 wrong before the contents has been restored from a copy in
2436 RAM, your target system will be dead.
2438 - CONFIG_ENV_ADDR_REDUND
2439 CONFIG_ENV_SIZE_REDUND
2441 These settings describe a second storage area used to hold
2442 a redundant copy of the environment data, so that there is
2443 a valid backup copy in case there is a power failure during
2444 a "saveenv" operation.
2446 BE CAREFUL! Any changes to the flash layout, and some changes to the
2447 source code will make it necessary to adapt <board>/u-boot.lds*
2451 - CONFIG_ENV_IS_IN_NVRAM:
2453 Define this if you have some non-volatile memory device
2454 (NVRAM, battery buffered SRAM) which you want to use for the
2460 These two #defines are used to determine the memory area you
2461 want to use for environment. It is assumed that this memory
2462 can just be read and written to, without any special
2465 BE CAREFUL! The first access to the environment happens quite early
2466 in U-Boot initalization (when we try to get the setting of for the
2467 console baudrate). You *MUST* have mapped your NVRAM area then, or
2470 Please note that even with NVRAM we still use a copy of the
2471 environment in RAM: we could work on NVRAM directly, but we want to
2472 keep settings there always unmodified except somebody uses "saveenv"
2473 to save the current settings.
2476 - CONFIG_ENV_IS_IN_EEPROM:
2478 Use this if you have an EEPROM or similar serial access
2479 device and a driver for it.
2481 - CONFIG_ENV_OFFSET:
2484 These two #defines specify the offset and size of the
2485 environment area within the total memory of your EEPROM.
2487 - CONFIG_SYS_I2C_EEPROM_ADDR:
2488 If defined, specified the chip address of the EEPROM device.
2489 The default address is zero.
2491 - CONFIG_SYS_EEPROM_PAGE_WRITE_BITS:
2492 If defined, the number of bits used to address bytes in a
2493 single page in the EEPROM device. A 64 byte page, for example
2494 would require six bits.
2496 - CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS:
2497 If defined, the number of milliseconds to delay between
2498 page writes. The default is zero milliseconds.
2500 - CONFIG_SYS_I2C_EEPROM_ADDR_LEN:
2501 The length in bytes of the EEPROM memory array address. Note
2502 that this is NOT the chip address length!
2504 - CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW:
2505 EEPROM chips that implement "address overflow" are ones
2506 like Catalyst 24WC04/08/16 which has 9/10/11 bits of
2507 address and the extra bits end up in the "chip address" bit
2508 slots. This makes a 24WC08 (1Kbyte) chip look like four 256
2511 Note that we consider the length of the address field to
2512 still be one byte because the extra address bits are hidden
2513 in the chip address.
2515 - CONFIG_SYS_EEPROM_SIZE:
2516 The size in bytes of the EEPROM device.
2518 - CONFIG_ENV_EEPROM_IS_ON_I2C
2519 define this, if you have I2C and SPI activated, and your
2520 EEPROM, which holds the environment, is on the I2C bus.
2522 - CONFIG_I2C_ENV_EEPROM_BUS
2523 if you have an Environment on an EEPROM reached over
2524 I2C muxes, you can define here, how to reach this
2525 EEPROM. For example:
2527 #define CONFIG_I2C_ENV_EEPROM_BUS "pca9547:70:d\0"
2529 EEPROM which holds the environment, is reached over
2530 a pca9547 i2c mux with address 0x70, channel 3.
2532 - CONFIG_ENV_IS_IN_DATAFLASH:
2534 Define this if you have a DataFlash memory device which you
2535 want to use for the environment.
2537 - CONFIG_ENV_OFFSET:
2541 These three #defines specify the offset and size of the
2542 environment area within the total memory of your DataFlash placed
2543 at the specified address.
2545 - CONFIG_ENV_IS_IN_NAND:
2547 Define this if you have a NAND device which you want to use
2548 for the environment.
2550 - CONFIG_ENV_OFFSET:
2553 These two #defines specify the offset and size of the environment
2554 area within the first NAND device. CONFIG_ENV_OFFSET must be
2555 aligned to an erase block boundary.
2557 - CONFIG_ENV_OFFSET_REDUND (optional):
2559 This setting describes a second storage area of CONFIG_ENV_SIZE
2560 size used to hold a redundant copy of the environment data, so
2561 that there is a valid backup copy in case there is a power failure
2562 during a "saveenv" operation. CONFIG_ENV_OFFSET_RENDUND must be
2563 aligned to an erase block boundary.
2565 - CONFIG_ENV_RANGE (optional):
2567 Specifies the length of the region in which the environment
2568 can be written. This should be a multiple of the NAND device's
2569 block size. Specifying a range with more erase blocks than
2570 are needed to hold CONFIG_ENV_SIZE allows bad blocks within
2571 the range to be avoided.
2573 - CONFIG_ENV_OFFSET_OOB (optional):
2575 Enables support for dynamically retrieving the offset of the
2576 environment from block zero's out-of-band data. The
2577 "nand env.oob" command can be used to record this offset.
2578 Currently, CONFIG_ENV_OFFSET_REDUND is not supported when
2579 using CONFIG_ENV_OFFSET_OOB.
2581 - CONFIG_NAND_ENV_DST
2583 Defines address in RAM to which the nand_spl code should copy the
2584 environment. If redundant environment is used, it will be copied to
2585 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE.
2587 - CONFIG_SYS_SPI_INIT_OFFSET
2589 Defines offset to the initial SPI buffer area in DPRAM. The
2590 area is used at an early stage (ROM part) if the environment
2591 is configured to reside in the SPI EEPROM: We need a 520 byte
2592 scratch DPRAM area. It is used between the two initialization
2593 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems
2594 to be a good choice since it makes it far enough from the
2595 start of the data area as well as from the stack pointer.
2597 Please note that the environment is read-only until the monitor
2598 has been relocated to RAM and a RAM copy of the environment has been
2599 created; also, when using EEPROM you will have to use getenv_f()
2600 until then to read environment variables.
2602 The environment is protected by a CRC32 checksum. Before the monitor
2603 is relocated into RAM, as a result of a bad CRC you will be working
2604 with the compiled-in default environment - *silently*!!! [This is
2605 necessary, because the first environment variable we need is the
2606 "baudrate" setting for the console - if we have a bad CRC, we don't
2607 have any device yet where we could complain.]
2609 Note: once the monitor has been relocated, then it will complain if
2610 the default environment is used; a new CRC is computed as soon as you
2611 use the "saveenv" command to store a valid environment.
2613 - CONFIG_SYS_FAULT_ECHO_LINK_DOWN:
2614 Echo the inverted Ethernet link state to the fault LED.
2616 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR
2617 also needs to be defined.
2619 - CONFIG_SYS_FAULT_MII_ADDR:
2620 MII address of the PHY to check for the Ethernet link state.
2622 - CONFIG_NS16550_MIN_FUNCTIONS:
2623 Define this if you desire to only have use of the NS16550_init
2624 and NS16550_putc functions for the serial driver located at
2625 drivers/serial/ns16550.c. This option is useful for saving
2626 space for already greatly restricted images, including but not
2627 limited to NAND_SPL configurations.
2629 Low Level (hardware related) configuration options:
2630 ---------------------------------------------------
2632 - CONFIG_SYS_CACHELINE_SIZE:
2633 Cache Line Size of the CPU.
2635 - CONFIG_SYS_DEFAULT_IMMR:
2636 Default address of the IMMR after system reset.
2638 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU,
2639 and RPXsuper) to be able to adjust the position of
2640 the IMMR register after a reset.
2642 - Floppy Disk Support:
2643 CONFIG_SYS_FDC_DRIVE_NUMBER
2645 the default drive number (default value 0)
2647 CONFIG_SYS_ISA_IO_STRIDE
2649 defines the spacing between FDC chipset registers
2652 CONFIG_SYS_ISA_IO_OFFSET
2654 defines the offset of register from address. It
2655 depends on which part of the data bus is connected to
2656 the FDC chipset. (default value 0)
2658 If CONFIG_SYS_ISA_IO_STRIDE CONFIG_SYS_ISA_IO_OFFSET and
2659 CONFIG_SYS_FDC_DRIVE_NUMBER are undefined, they take their
2662 if CONFIG_SYS_FDC_HW_INIT is defined, then the function
2663 fdc_hw_init() is called at the beginning of the FDC
2664 setup. fdc_hw_init() must be provided by the board
2665 source code. It is used to make hardware dependant
2668 - CONFIG_SYS_IMMR: Physical address of the Internal Memory.
2669 DO NOT CHANGE unless you know exactly what you're
2670 doing! (11-4) [MPC8xx/82xx systems only]
2672 - CONFIG_SYS_INIT_RAM_ADDR:
2674 Start address of memory area that can be used for
2675 initial data and stack; please note that this must be
2676 writable memory that is working WITHOUT special
2677 initialization, i. e. you CANNOT use normal RAM which
2678 will become available only after programming the
2679 memory controller and running certain initialization
2682 U-Boot uses the following memory types:
2683 - MPC8xx and MPC8260: IMMR (internal memory of the CPU)
2684 - MPC824X: data cache
2685 - PPC4xx: data cache
2687 - CONFIG_SYS_GBL_DATA_OFFSET:
2689 Offset of the initial data structure in the memory
2690 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually
2691 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial
2692 data is located at the end of the available space
2693 (sometimes written as (CONFIG_SYS_INIT_RAM_SIZE -
2694 CONFIG_SYS_INIT_DATA_SIZE), and the initial stack is just
2695 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR +
2696 CONFIG_SYS_GBL_DATA_OFFSET) downward.
2699 On the MPC824X (or other systems that use the data
2700 cache for initial memory) the address chosen for
2701 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must
2702 point to an otherwise UNUSED address space between
2703 the top of RAM and the start of the PCI space.
2705 - CONFIG_SYS_SIUMCR: SIU Module Configuration (11-6)
2707 - CONFIG_SYS_SYPCR: System Protection Control (11-9)
2709 - CONFIG_SYS_TBSCR: Time Base Status and Control (11-26)
2711 - CONFIG_SYS_PISCR: Periodic Interrupt Status and Control (11-31)
2713 - CONFIG_SYS_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30)
2715 - CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27)
2717 - CONFIG_SYS_OR_TIMING_SDRAM:
2720 - CONFIG_SYS_MAMR_PTA:
2721 periodic timer for refresh
2723 - CONFIG_SYS_DER: Debug Event Register (37-47)
2725 - FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM,
2726 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP,
2727 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM,
2728 CONFIG_SYS_BR1_PRELIM:
2729 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
2731 - SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
2732 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM,
2733 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM:
2734 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
2736 - CONFIG_SYS_MAMR_PTA, CONFIG_SYS_MPTPR_2BK_4K, CONFIG_SYS_MPTPR_1BK_4K, CONFIG_SYS_MPTPR_2BK_8K,
2737 CONFIG_SYS_MPTPR_1BK_8K, CONFIG_SYS_MAMR_8COL, CONFIG_SYS_MAMR_9COL:
2738 Machine Mode Register and Memory Periodic Timer
2739 Prescaler definitions (SDRAM timing)
2741 - CONFIG_SYS_I2C_UCODE_PATCH, CONFIG_SYS_I2C_DPMEM_OFFSET [0x1FC0]:
2742 enable I2C microcode relocation patch (MPC8xx);
2743 define relocation offset in DPRAM [DSP2]
2745 - CONFIG_SYS_SMC_UCODE_PATCH, CONFIG_SYS_SMC_DPMEM_OFFSET [0x1FC0]:
2746 enable SMC microcode relocation patch (MPC8xx);
2747 define relocation offset in DPRAM [SMC1]
2749 - CONFIG_SYS_SPI_UCODE_PATCH, CONFIG_SYS_SPI_DPMEM_OFFSET [0x1FC0]:
2750 enable SPI microcode relocation patch (MPC8xx);
2751 define relocation offset in DPRAM [SCC4]
2753 - CONFIG_SYS_USE_OSCCLK:
2754 Use OSCM clock mode on MBX8xx board. Be careful,
2755 wrong setting might damage your board. Read
2756 doc/README.MBX before setting this variable!
2758 - CONFIG_SYS_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only)
2759 Offset of the bootmode word in DPRAM used by post
2760 (Power On Self Tests). This definition overrides
2761 #define'd default value in commproc.h resp.
2764 - CONFIG_SYS_PCI_SLV_MEM_LOCAL, CONFIG_SYS_PCI_SLV_MEM_BUS, CONFIG_SYS_PICMR0_MASK_ATTRIB,
2765 CONFIG_SYS_PCI_MSTR0_LOCAL, CONFIG_SYS_PCIMSK0_MASK, CONFIG_SYS_PCI_MSTR1_LOCAL,
2766 CONFIG_SYS_PCIMSK1_MASK, CONFIG_SYS_PCI_MSTR_MEM_LOCAL, CONFIG_SYS_PCI_MSTR_MEM_BUS,
2767 CONFIG_SYS_CPU_PCI_MEM_START, CONFIG_SYS_PCI_MSTR_MEM_SIZE, CONFIG_SYS_POCMR0_MASK_ATTRIB,
2768 CONFIG_SYS_PCI_MSTR_MEMIO_LOCAL, CONFIG_SYS_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START,
2769 CONFIG_SYS_PCI_MSTR_MEMIO_SIZE, CONFIG_SYS_POCMR1_MASK_ATTRIB, CONFIG_SYS_PCI_MSTR_IO_LOCAL,
2770 CONFIG_SYS_PCI_MSTR_IO_BUS, CONFIG_SYS_CPU_PCI_IO_START, CONFIG_SYS_PCI_MSTR_IO_SIZE,
2771 CONFIG_SYS_POCMR2_MASK_ATTRIB: (MPC826x only)
2772 Overrides the default PCI memory map in arch/powerpc/cpu/mpc8260/pci.c if set.
2774 - CONFIG_PCI_DISABLE_PCIE:
2775 Disable PCI-Express on systems where it is supported but not
2779 Get DDR timing information from an I2C EEPROM. Common
2780 with pluggable memory modules such as SODIMMs
2783 I2C address of the SPD EEPROM
2785 - CONFIG_SYS_SPD_BUS_NUM
2786 If SPD EEPROM is on an I2C bus other than the first
2787 one, specify here. Note that the value must resolve
2788 to something your driver can deal with.
2790 - CONFIG_SYS_83XX_DDR_USES_CS0
2791 Only for 83xx systems. If specified, then DDR should
2792 be configured using CS0 and CS1 instead of CS2 and CS3.
2794 - CONFIG_ETHER_ON_FEC[12]
2795 Define to enable FEC[12] on a 8xx series processor.
2797 - CONFIG_FEC[12]_PHY
2798 Define to the hardcoded PHY address which corresponds
2799 to the given FEC; i. e.
2800 #define CONFIG_FEC1_PHY 4
2801 means that the PHY with address 4 is connected to FEC1
2803 When set to -1, means to probe for first available.
2805 - CONFIG_FEC[12]_PHY_NORXERR
2806 The PHY does not have a RXERR line (RMII only).
2807 (so program the FEC to ignore it).
2810 Enable RMII mode for all FECs.
2811 Note that this is a global option, we can't
2812 have one FEC in standard MII mode and another in RMII mode.
2814 - CONFIG_CRC32_VERIFY
2815 Add a verify option to the crc32 command.
2818 => crc32 -v <address> <count> <crc32>
2820 Where address/count indicate a memory area
2821 and crc32 is the correct crc32 which the
2825 Add the "loopw" memory command. This only takes effect if
2826 the memory commands are activated globally (CONFIG_CMD_MEM).
2829 Add the "mdc" and "mwc" memory commands. These are cyclic
2834 This command will print 4 bytes (10,11,12,13) each 500 ms.
2836 => mwc.l 100 12345678 10
2837 This command will write 12345678 to address 100 all 10 ms.
2839 This only takes effect if the memory commands are activated
2840 globally (CONFIG_CMD_MEM).
2842 - CONFIG_SKIP_LOWLEVEL_INIT
2843 [ARM only] If this variable is defined, then certain
2844 low level initializations (like setting up the memory
2845 controller) are omitted and/or U-Boot does not
2846 relocate itself into RAM.
2848 Normally this variable MUST NOT be defined. The only
2849 exception is when U-Boot is loaded (to RAM) by some
2850 other boot loader or by a debugger which performs
2851 these initializations itself.
2854 Modifies the behaviour of start.S when compiling a loader
2855 that is executed before the actual U-Boot. E.g. when
2856 compiling a NAND SPL.
2858 Building the Software:
2859 ======================
2861 Building U-Boot has been tested in several native build environments
2862 and in many different cross environments. Of course we cannot support
2863 all possibly existing versions of cross development tools in all
2864 (potentially obsolete) versions. In case of tool chain problems we
2865 recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK)
2866 which is extensively used to build and test U-Boot.
2868 If you are not using a native environment, it is assumed that you
2869 have GNU cross compiling tools available in your path. In this case,
2870 you must set the environment variable CROSS_COMPILE in your shell.
2871 Note that no changes to the Makefile or any other source files are
2872 necessary. For example using the ELDK on a 4xx CPU, please enter:
2874 $ CROSS_COMPILE=ppc_4xx-
2875 $ export CROSS_COMPILE
2877 Note: If you wish to generate Windows versions of the utilities in
2878 the tools directory you can use the MinGW toolchain
2879 (http://www.mingw.org). Set your HOST tools to the MinGW
2880 toolchain and execute 'make tools'. For example:
2882 $ make HOSTCC=i586-mingw32msvc-gcc HOSTSTRIP=i586-mingw32msvc-strip tools
2884 Binaries such as tools/mkimage.exe will be created which can
2885 be executed on computers running Windows.
2887 U-Boot is intended to be simple to build. After installing the
2888 sources you must configure U-Boot for one specific board type. This
2893 where "NAME_config" is the name of one of the existing configu-
2894 rations; see the main Makefile for supported names.
2896 Note: for some board special configuration names may exist; check if
2897 additional information is available from the board vendor; for
2898 instance, the TQM823L systems are available without (standard)
2899 or with LCD support. You can select such additional "features"
2900 when choosing the configuration, i. e.
2903 - will configure for a plain TQM823L, i. e. no LCD support
2905 make TQM823L_LCD_config
2906 - will configure for a TQM823L with U-Boot console on LCD
2911 Finally, type "make all", and you should get some working U-Boot
2912 images ready for download to / installation on your system:
2914 - "u-boot.bin" is a raw binary image
2915 - "u-boot" is an image in ELF binary format
2916 - "u-boot.srec" is in Motorola S-Record format
2918 By default the build is performed locally and the objects are saved
2919 in the source directory. One of the two methods can be used to change
2920 this behavior and build U-Boot to some external directory:
2922 1. Add O= to the make command line invocations:
2924 make O=/tmp/build distclean
2925 make O=/tmp/build NAME_config
2926 make O=/tmp/build all
2928 2. Set environment variable BUILD_DIR to point to the desired location:
2930 export BUILD_DIR=/tmp/build
2935 Note that the command line "O=" setting overrides the BUILD_DIR environment
2939 Please be aware that the Makefiles assume you are using GNU make, so
2940 for instance on NetBSD you might need to use "gmake" instead of
2944 If the system board that you have is not listed, then you will need
2945 to port U-Boot to your hardware platform. To do this, follow these
2948 1. Add a new configuration option for your board to the toplevel
2949 "Makefile" and to the "MAKEALL" script, using the existing
2950 entries as examples. Note that here and at many other places
2951 boards and other names are listed in alphabetical sort order. Please
2953 2. Create a new directory to hold your board specific code. Add any
2954 files you need. In your board directory, you will need at least
2955 the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds".
2956 3. Create a new configuration file "include/configs/<board>.h" for
2958 3. If you're porting U-Boot to a new CPU, then also create a new
2959 directory to hold your CPU specific code. Add any files you need.
2960 4. Run "make <board>_config" with your new name.
2961 5. Type "make", and you should get a working "u-boot.srec" file
2962 to be installed on your target system.
2963 6. Debug and solve any problems that might arise.
2964 [Of course, this last step is much harder than it sounds.]
2967 Testing of U-Boot Modifications, Ports to New Hardware, etc.:
2968 ==============================================================
2970 If you have modified U-Boot sources (for instance added a new board
2971 or support for new devices, a new CPU, etc.) you are expected to
2972 provide feedback to the other developers. The feedback normally takes
2973 the form of a "patch", i. e. a context diff against a certain (latest
2974 official or latest in the git repository) version of U-Boot sources.
2976 But before you submit such a patch, please verify that your modifi-
2977 cation did not break existing code. At least make sure that *ALL* of
2978 the supported boards compile WITHOUT ANY compiler warnings. To do so,
2979 just run the "MAKEALL" script, which will configure and build U-Boot
2980 for ALL supported system. Be warned, this will take a while. You can
2981 select which (cross) compiler to use by passing a `CROSS_COMPILE'
2982 environment variable to the script, i. e. to use the ELDK cross tools
2985 CROSS_COMPILE=ppc_8xx- MAKEALL
2987 or to build on a native PowerPC system you can type
2989 CROSS_COMPILE=' ' MAKEALL
2991 When using the MAKEALL script, the default behaviour is to build
2992 U-Boot in the source directory. This location can be changed by
2993 setting the BUILD_DIR environment variable. Also, for each target
2994 built, the MAKEALL script saves two log files (<target>.ERR and
2995 <target>.MAKEALL) in the <source dir>/LOG directory. This default
2996 location can be changed by setting the MAKEALL_LOGDIR environment
2997 variable. For example:
2999 export BUILD_DIR=/tmp/build
3000 export MAKEALL_LOGDIR=/tmp/log
3001 CROSS_COMPILE=ppc_8xx- MAKEALL
3003 With the above settings build objects are saved in the /tmp/build,
3004 log files are saved in the /tmp/log and the source tree remains clean
3005 during the whole build process.
3008 See also "U-Boot Porting Guide" below.
3011 Monitor Commands - Overview:
3012 ============================
3014 go - start application at address 'addr'
3015 run - run commands in an environment variable
3016 bootm - boot application image from memory
3017 bootp - boot image via network using BootP/TFTP protocol
3018 tftpboot- boot image via network using TFTP protocol
3019 and env variables "ipaddr" and "serverip"
3020 (and eventually "gatewayip")
3021 rarpboot- boot image via network using RARP/TFTP protocol
3022 diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
3023 loads - load S-Record file over serial line
3024 loadb - load binary file over serial line (kermit mode)
3026 mm - memory modify (auto-incrementing)
3027 nm - memory modify (constant address)
3028 mw - memory write (fill)
3030 cmp - memory compare
3031 crc32 - checksum calculation
3032 i2c - I2C sub-system
3033 sspi - SPI utility commands
3034 base - print or set address offset
3035 printenv- print environment variables
3036 setenv - set environment variables
3037 saveenv - save environment variables to persistent storage
3038 protect - enable or disable FLASH write protection
3039 erase - erase FLASH memory
3040 flinfo - print FLASH memory information
3041 bdinfo - print Board Info structure
3042 iminfo - print header information for application image
3043 coninfo - print console devices and informations
3044 ide - IDE sub-system
3045 loop - infinite loop on address range
3046 loopw - infinite write loop on address range
3047 mtest - simple RAM test
3048 icache - enable or disable instruction cache
3049 dcache - enable or disable data cache
3050 reset - Perform RESET of the CPU
3051 echo - echo args to console
3052 version - print monitor version
3053 help - print online help
3054 ? - alias for 'help'
3057 Monitor Commands - Detailed Description:
3058 ========================================
3062 For now: just type "help <command>".
3065 Environment Variables:
3066 ======================
3068 U-Boot supports user configuration using Environment Variables which
3069 can be made persistent by saving to Flash memory.
3071 Environment Variables are set using "setenv", printed using
3072 "printenv", and saved to Flash using "saveenv". Using "setenv"
3073 without a value can be used to delete a variable from the
3074 environment. As long as you don't save the environment you are
3075 working with an in-memory copy. In case the Flash area containing the
3076 environment is erased by accident, a default environment is provided.
3078 Some configuration options can be set using Environment Variables.
3080 List of environment variables (most likely not complete):
3082 baudrate - see CONFIG_BAUDRATE
3084 bootdelay - see CONFIG_BOOTDELAY
3086 bootcmd - see CONFIG_BOOTCOMMAND
3088 bootargs - Boot arguments when booting an RTOS image
3090 bootfile - Name of the image to load with TFTP
3092 bootm_low - Memory range available for image processing in the bootm
3093 command can be restricted. This variable is given as
3094 a hexadecimal number and defines lowest address allowed
3095 for use by the bootm command. See also "bootm_size"
3096 environment variable. Address defined by "bootm_low" is
3097 also the base of the initial memory mapping for the Linux
3098 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ.
3100 bootm_size - Memory range available for image processing in the bootm
3101 command can be restricted. This variable is given as
3102 a hexadecimal number and defines the size of the region
3103 allowed for use by the bootm command. See also "bootm_low"
3104 environment variable.
3106 updatefile - Location of the software update file on a TFTP server, used
3107 by the automatic software update feature. Please refer to
3108 documentation in doc/README.update for more details.
3110 autoload - if set to "no" (any string beginning with 'n'),
3111 "bootp" will just load perform a lookup of the
3112 configuration from the BOOTP server, but not try to
3113 load any image using TFTP
3115 autostart - if set to "yes", an image loaded using the "bootp",
3116 "rarpboot", "tftpboot" or "diskboot" commands will
3117 be automatically started (by internally calling
3120 If set to "no", a standalone image passed to the
3121 "bootm" command will be copied to the load address
3122 (and eventually uncompressed), but NOT be started.
3123 This can be used to load and uncompress arbitrary
3126 i2cfast - (PPC405GP|PPC405EP only)
3127 if set to 'y' configures Linux I2C driver for fast
3128 mode (400kHZ). This environment variable is used in
3129 initialization code. So, for changes to be effective
3130 it must be saved and board must be reset.
3132 initrd_high - restrict positioning of initrd images:
3133 If this variable is not set, initrd images will be
3134 copied to the highest possible address in RAM; this
3135 is usually what you want since it allows for
3136 maximum initrd size. If for some reason you want to
3137 make sure that the initrd image is loaded below the
3138 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment
3139 variable to a value of "no" or "off" or "0".
3140 Alternatively, you can set it to a maximum upper
3141 address to use (U-Boot will still check that it
3142 does not overwrite the U-Boot stack and data).
3144 For instance, when you have a system with 16 MB
3145 RAM, and want to reserve 4 MB from use by Linux,
3146 you can do this by adding "mem=12M" to the value of
3147 the "bootargs" variable. However, now you must make
3148 sure that the initrd image is placed in the first
3149 12 MB as well - this can be done with
3151 setenv initrd_high 00c00000
3153 If you set initrd_high to 0xFFFFFFFF, this is an
3154 indication to U-Boot that all addresses are legal
3155 for the Linux kernel, including addresses in flash
3156 memory. In this case U-Boot will NOT COPY the
3157 ramdisk at all. This may be useful to reduce the
3158 boot time on your system, but requires that this
3159 feature is supported by your Linux kernel.
3161 ipaddr - IP address; needed for tftpboot command
3163 loadaddr - Default load address for commands like "bootp",
3164 "rarpboot", "tftpboot", "loadb" or "diskboot"
3166 loads_echo - see CONFIG_LOADS_ECHO
3168 serverip - TFTP server IP address; needed for tftpboot command
3170 bootretry - see CONFIG_BOOT_RETRY_TIME
3172 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
3174 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
3176 ethprime - When CONFIG_NET_MULTI is enabled controls which
3177 interface is used first.
3179 ethact - When CONFIG_NET_MULTI is enabled controls which
3180 interface is currently active. For example you
3181 can do the following
3183 => setenv ethact FEC
3184 => ping 192.168.0.1 # traffic sent on FEC
3185 => setenv ethact SCC
3186 => ping 10.0.0.1 # traffic sent on SCC
3188 ethrotate - When set to "no" U-Boot does not go through all
3189 available network interfaces.
3190 It just stays at the currently selected interface.
3192 netretry - When set to "no" each network operation will
3193 either succeed or fail without retrying.
3194 When set to "once" the network operation will
3195 fail when all the available network interfaces
3196 are tried once without success.
3197 Useful on scripts which control the retry operation
3200 npe_ucode - set load address for the NPE microcode
3202 tftpsrcport - If this is set, the value is used for TFTP's
3205 tftpdstport - If this is set, the value is used for TFTP's UDP
3206 destination port instead of the Well Know Port 69.
3208 tftpblocksize - Block size to use for TFTP transfers; if not set,
3209 we use the TFTP server's default block size
3211 tftptimeout - Retransmission timeout for TFTP packets (in milli-
3212 seconds, minimum value is 1000 = 1 second). Defines
3213 when a packet is considered to be lost so it has to
3214 be retransmitted. The default is 5000 = 5 seconds.
3215 Lowering this value may make downloads succeed
3216 faster in networks with high packet loss rates or
3217 with unreliable TFTP servers.
3219 vlan - When set to a value < 4095 the traffic over
3220 Ethernet is encapsulated/received over 802.1q
3223 The following environment variables may be used and automatically
3224 updated by the network boot commands ("bootp" and "rarpboot"),
3225 depending the information provided by your boot server:
3227 bootfile - see above
3228 dnsip - IP address of your Domain Name Server
3229 dnsip2 - IP address of your secondary Domain Name Server
3230 gatewayip - IP address of the Gateway (Router) to use
3231 hostname - Target hostname
3233 netmask - Subnet Mask
3234 rootpath - Pathname of the root filesystem on the NFS server
3235 serverip - see above
3238 There are two special Environment Variables:
3240 serial# - contains hardware identification information such
3241 as type string and/or serial number
3242 ethaddr - Ethernet address
3244 These variables can be set only once (usually during manufacturing of
3245 the board). U-Boot refuses to delete or overwrite these variables
3246 once they have been set once.
3249 Further special Environment Variables:
3251 ver - Contains the U-Boot version string as printed
3252 with the "version" command. This variable is
3253 readonly (see CONFIG_VERSION_VARIABLE).
3256 Please note that changes to some configuration parameters may take
3257 only effect after the next boot (yes, that's just like Windoze :-).
3260 Command Line Parsing:
3261 =====================
3263 There are two different command line parsers available with U-Boot:
3264 the old "simple" one, and the much more powerful "hush" shell:
3266 Old, simple command line parser:
3267 --------------------------------
3269 - supports environment variables (through setenv / saveenv commands)
3270 - several commands on one line, separated by ';'
3271 - variable substitution using "... ${name} ..." syntax
3272 - special characters ('$', ';') can be escaped by prefixing with '\',
3274 setenv bootcmd bootm \${address}
3275 - You can also escape text by enclosing in single apostrophes, for example:
3276 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
3281 - similar to Bourne shell, with control structures like
3282 if...then...else...fi, for...do...done; while...do...done,
3283 until...do...done, ...
3284 - supports environment ("global") variables (through setenv / saveenv
3285 commands) and local shell variables (through standard shell syntax
3286 "name=value"); only environment variables can be used with "run"
3292 (1) If a command line (or an environment variable executed by a "run"
3293 command) contains several commands separated by semicolon, and
3294 one of these commands fails, then the remaining commands will be
3297 (2) If you execute several variables with one call to run (i. e.
3298 calling run with a list of variables as arguments), any failing
3299 command will cause "run" to terminate, i. e. the remaining
3300 variables are not executed.
3302 Note for Redundant Ethernet Interfaces:
3303 =======================================
3305 Some boards come with redundant Ethernet interfaces; U-Boot supports
3306 such configurations and is capable of automatic selection of a
3307 "working" interface when needed. MAC assignment works as follows:
3309 Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
3310 MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
3311 "eth1addr" (=>eth1), "eth2addr", ...
3313 If the network interface stores some valid MAC address (for instance
3314 in SROM), this is used as default address if there is NO correspon-
3315 ding setting in the environment; if the corresponding environment
3316 variable is set, this overrides the settings in the card; that means:
3318 o If the SROM has a valid MAC address, and there is no address in the
3319 environment, the SROM's address is used.
3321 o If there is no valid address in the SROM, and a definition in the
3322 environment exists, then the value from the environment variable is
3325 o If both the SROM and the environment contain a MAC address, and
3326 both addresses are the same, this MAC address is used.
3328 o If both the SROM and the environment contain a MAC address, and the
3329 addresses differ, the value from the environment is used and a
3332 o If neither SROM nor the environment contain a MAC address, an error
3335 If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses
3336 will be programmed into hardware as part of the initialization process. This
3337 may be skipped by setting the appropriate 'ethmacskip' environment variable.
3338 The naming convention is as follows:
3339 "ethmacskip" (=>eth0), "eth1macskip" (=>eth1) etc.
3344 U-Boot is capable of booting (and performing other auxiliary operations on)
3345 images in two formats:
3347 New uImage format (FIT)
3348 -----------------------
3350 Flexible and powerful format based on Flattened Image Tree -- FIT (similar
3351 to Flattened Device Tree). It allows the use of images with multiple
3352 components (several kernels, ramdisks, etc.), with contents protected by
3353 SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory.
3359 Old image format is based on binary files which can be basically anything,
3360 preceded by a special header; see the definitions in include/image.h for
3361 details; basically, the header defines the following image properties:
3363 * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
3364 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
3365 LynxOS, pSOS, QNX, RTEMS, INTEGRITY;
3366 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS,
3368 * Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86,
3369 IA64, MIPS, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
3370 Currently supported: ARM, AVR32, Intel x86, MIPS, Nios II, PowerPC).
3371 * Compression Type (uncompressed, gzip, bzip2)
3377 The header is marked by a special Magic Number, and both the header
3378 and the data portions of the image are secured against corruption by
3385 Although U-Boot should support any OS or standalone application
3386 easily, the main focus has always been on Linux during the design of
3389 U-Boot includes many features that so far have been part of some
3390 special "boot loader" code within the Linux kernel. Also, any
3391 "initrd" images to be used are no longer part of one big Linux image;
3392 instead, kernel and "initrd" are separate images. This implementation
3393 serves several purposes:
3395 - the same features can be used for other OS or standalone
3396 applications (for instance: using compressed images to reduce the
3397 Flash memory footprint)
3399 - it becomes much easier to port new Linux kernel versions because
3400 lots of low-level, hardware dependent stuff are done by U-Boot
3402 - the same Linux kernel image can now be used with different "initrd"
3403 images; of course this also means that different kernel images can
3404 be run with the same "initrd". This makes testing easier (you don't
3405 have to build a new "zImage.initrd" Linux image when you just
3406 change a file in your "initrd"). Also, a field-upgrade of the
3407 software is easier now.
3413 Porting Linux to U-Boot based systems:
3414 ---------------------------------------
3416 U-Boot cannot save you from doing all the necessary modifications to
3417 configure the Linux device drivers for use with your target hardware
3418 (no, we don't intend to provide a full virtual machine interface to
3421 But now you can ignore ALL boot loader code (in arch/powerpc/mbxboot).
3423 Just make sure your machine specific header file (for instance
3424 include/asm-ppc/tqm8xx.h) includes the same definition of the Board
3425 Information structure as we define in include/asm-<arch>/u-boot.h,
3426 and make sure that your definition of IMAP_ADDR uses the same value
3427 as your U-Boot configuration in CONFIG_SYS_IMMR.
3430 Configuring the Linux kernel:
3431 -----------------------------
3433 No specific requirements for U-Boot. Make sure you have some root
3434 device (initial ramdisk, NFS) for your target system.
3437 Building a Linux Image:
3438 -----------------------
3440 With U-Boot, "normal" build targets like "zImage" or "bzImage" are
3441 not used. If you use recent kernel source, a new build target
3442 "uImage" will exist which automatically builds an image usable by
3443 U-Boot. Most older kernels also have support for a "pImage" target,
3444 which was introduced for our predecessor project PPCBoot and uses a
3445 100% compatible format.
3454 The "uImage" build target uses a special tool (in 'tools/mkimage') to
3455 encapsulate a compressed Linux kernel image with header information,
3456 CRC32 checksum etc. for use with U-Boot. This is what we are doing:
3458 * build a standard "vmlinux" kernel image (in ELF binary format):
3460 * convert the kernel into a raw binary image:
3462 ${CROSS_COMPILE}-objcopy -O binary \
3463 -R .note -R .comment \
3464 -S vmlinux linux.bin
3466 * compress the binary image:
3470 * package compressed binary image for U-Boot:
3472 mkimage -A ppc -O linux -T kernel -C gzip \
3473 -a 0 -e 0 -n "Linux Kernel Image" \
3474 -d linux.bin.gz uImage
3477 The "mkimage" tool can also be used to create ramdisk images for use
3478 with U-Boot, either separated from the Linux kernel image, or
3479 combined into one file. "mkimage" encapsulates the images with a 64
3480 byte header containing information about target architecture,
3481 operating system, image type, compression method, entry points, time
3482 stamp, CRC32 checksums, etc.
3484 "mkimage" can be called in two ways: to verify existing images and
3485 print the header information, or to build new images.
3487 In the first form (with "-l" option) mkimage lists the information
3488 contained in the header of an existing U-Boot image; this includes
3489 checksum verification:
3491 tools/mkimage -l image
3492 -l ==> list image header information
3494 The second form (with "-d" option) is used to build a U-Boot image
3495 from a "data file" which is used as image payload:
3497 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
3498 -n name -d data_file image
3499 -A ==> set architecture to 'arch'
3500 -O ==> set operating system to 'os'
3501 -T ==> set image type to 'type'
3502 -C ==> set compression type 'comp'
3503 -a ==> set load address to 'addr' (hex)
3504 -e ==> set entry point to 'ep' (hex)
3505 -n ==> set image name to 'name'
3506 -d ==> use image data from 'datafile'
3508 Right now, all Linux kernels for PowerPC systems use the same load
3509 address (0x00000000), but the entry point address depends on the
3512 - 2.2.x kernels have the entry point at 0x0000000C,
3513 - 2.3.x and later kernels have the entry point at 0x00000000.
3515 So a typical call to build a U-Boot image would read:
3517 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
3518 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
3519 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz \
3520 > examples/uImage.TQM850L
3521 Image Name: 2.4.4 kernel for TQM850L
3522 Created: Wed Jul 19 02:34:59 2000
3523 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3524 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
3525 Load Address: 0x00000000
3526 Entry Point: 0x00000000
3528 To verify the contents of the image (or check for corruption):
3530 -> tools/mkimage -l examples/uImage.TQM850L
3531 Image Name: 2.4.4 kernel for TQM850L
3532 Created: Wed Jul 19 02:34:59 2000
3533 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3534 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
3535 Load Address: 0x00000000
3536 Entry Point: 0x00000000
3538 NOTE: for embedded systems where boot time is critical you can trade
3539 speed for memory and install an UNCOMPRESSED image instead: this
3540 needs more space in Flash, but boots much faster since it does not
3541 need to be uncompressed:
3543 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz
3544 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
3545 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
3546 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux \
3547 > examples/uImage.TQM850L-uncompressed
3548 Image Name: 2.4.4 kernel for TQM850L
3549 Created: Wed Jul 19 02:34:59 2000
3550 Image Type: PowerPC Linux Kernel Image (uncompressed)
3551 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
3552 Load Address: 0x00000000
3553 Entry Point: 0x00000000
3556 Similar you can build U-Boot images from a 'ramdisk.image.gz' file
3557 when your kernel is intended to use an initial ramdisk:
3559 -> tools/mkimage -n 'Simple Ramdisk Image' \
3560 > -A ppc -O linux -T ramdisk -C gzip \
3561 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
3562 Image Name: Simple Ramdisk Image
3563 Created: Wed Jan 12 14:01:50 2000
3564 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
3565 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
3566 Load Address: 0x00000000
3567 Entry Point: 0x00000000
3570 Installing a Linux Image:
3571 -------------------------
3573 To downloading a U-Boot image over the serial (console) interface,
3574 you must convert the image to S-Record format:
3576 objcopy -I binary -O srec examples/image examples/image.srec
3578 The 'objcopy' does not understand the information in the U-Boot
3579 image header, so the resulting S-Record file will be relative to
3580 address 0x00000000. To load it to a given address, you need to
3581 specify the target address as 'offset' parameter with the 'loads'
3584 Example: install the image to address 0x40100000 (which on the
3585 TQM8xxL is in the first Flash bank):
3587 => erase 40100000 401FFFFF
3593 ## Ready for S-Record download ...
3594 ~>examples/image.srec
3595 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
3597 15989 15990 15991 15992
3598 [file transfer complete]
3600 ## Start Addr = 0x00000000
3603 You can check the success of the download using the 'iminfo' command;
3604 this includes a checksum verification so you can be sure no data
3605 corruption happened:
3609 ## Checking Image at 40100000 ...
3610 Image Name: 2.2.13 for initrd on TQM850L
3611 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3612 Data Size: 335725 Bytes = 327 kB = 0 MB
3613 Load Address: 00000000
3614 Entry Point: 0000000c
3615 Verifying Checksum ... OK
3621 The "bootm" command is used to boot an application that is stored in
3622 memory (RAM or Flash). In case of a Linux kernel image, the contents
3623 of the "bootargs" environment variable is passed to the kernel as
3624 parameters. You can check and modify this variable using the
3625 "printenv" and "setenv" commands:
3628 => printenv bootargs
3629 bootargs=root=/dev/ram
3631 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
3633 => printenv bootargs
3634 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
3637 ## Booting Linux kernel at 40020000 ...
3638 Image Name: 2.2.13 for NFS on TQM850L
3639 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3640 Data Size: 381681 Bytes = 372 kB = 0 MB
3641 Load Address: 00000000
3642 Entry Point: 0000000c
3643 Verifying Checksum ... OK
3644 Uncompressing Kernel Image ... OK
3645 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
3646 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
3647 time_init: decrementer frequency = 187500000/60
3648 Calibrating delay loop... 49.77 BogoMIPS
3649 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
3652 If you want to boot a Linux kernel with initial RAM disk, you pass
3653 the memory addresses of both the kernel and the initrd image (PPBCOOT
3654 format!) to the "bootm" command:
3656 => imi 40100000 40200000
3658 ## Checking Image at 40100000 ...
3659 Image Name: 2.2.13 for initrd on TQM850L
3660 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3661 Data Size: 335725 Bytes = 327 kB = 0 MB
3662 Load Address: 00000000
3663 Entry Point: 0000000c
3664 Verifying Checksum ... OK
3666 ## Checking Image at 40200000 ...
3667 Image Name: Simple Ramdisk Image
3668 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
3669 Data Size: 566530 Bytes = 553 kB = 0 MB
3670 Load Address: 00000000
3671 Entry Point: 00000000
3672 Verifying Checksum ... OK
3674 => bootm 40100000 40200000
3675 ## Booting Linux kernel at 40100000 ...
3676 Image Name: 2.2.13 for initrd on TQM850L
3677 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3678 Data Size: 335725 Bytes = 327 kB = 0 MB
3679 Load Address: 00000000
3680 Entry Point: 0000000c
3681 Verifying Checksum ... OK
3682 Uncompressing Kernel Image ... OK
3683 ## Loading RAMDisk Image at 40200000 ...
3684 Image Name: Simple Ramdisk Image
3685 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
3686 Data Size: 566530 Bytes = 553 kB = 0 MB
3687 Load Address: 00000000
3688 Entry Point: 00000000
3689 Verifying Checksum ... OK
3690 Loading Ramdisk ... OK
3691 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
3692 Boot arguments: root=/dev/ram
3693 time_init: decrementer frequency = 187500000/60
3694 Calibrating delay loop... 49.77 BogoMIPS
3696 RAMDISK: Compressed image found at block 0
3697 VFS: Mounted root (ext2 filesystem).
3701 Boot Linux and pass a flat device tree:
3704 First, U-Boot must be compiled with the appropriate defines. See the section
3705 titled "Linux Kernel Interface" above for a more in depth explanation. The
3706 following is an example of how to start a kernel and pass an updated
3712 oft=oftrees/mpc8540ads.dtb
3713 => tftp $oftaddr $oft
3714 Speed: 1000, full duplex
3716 TFTP from server 192.168.1.1; our IP address is 192.168.1.101
3717 Filename 'oftrees/mpc8540ads.dtb'.
3718 Load address: 0x300000
3721 Bytes transferred = 4106 (100a hex)
3722 => tftp $loadaddr $bootfile
3723 Speed: 1000, full duplex
3725 TFTP from server 192.168.1.1; our IP address is 192.168.1.2
3727 Load address: 0x200000
3728 Loading:############
3730 Bytes transferred = 1029407 (fb51f hex)
3735 => bootm $loadaddr - $oftaddr
3736 ## Booting image at 00200000 ...
3737 Image Name: Linux-2.6.17-dirty
3738 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3739 Data Size: 1029343 Bytes = 1005.2 kB
3740 Load Address: 00000000
3741 Entry Point: 00000000
3742 Verifying Checksum ... OK
3743 Uncompressing Kernel Image ... OK
3744 Booting using flat device tree at 0x300000
3745 Using MPC85xx ADS machine description
3746 Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb
3750 More About U-Boot Image Types:
3751 ------------------------------
3753 U-Boot supports the following image types:
3755 "Standalone Programs" are directly runnable in the environment
3756 provided by U-Boot; it is expected that (if they behave
3757 well) you can continue to work in U-Boot after return from
3758 the Standalone Program.
3759 "OS Kernel Images" are usually images of some Embedded OS which
3760 will take over control completely. Usually these programs
3761 will install their own set of exception handlers, device
3762 drivers, set up the MMU, etc. - this means, that you cannot
3763 expect to re-enter U-Boot except by resetting the CPU.
3764 "RAMDisk Images" are more or less just data blocks, and their
3765 parameters (address, size) are passed to an OS kernel that is
3767 "Multi-File Images" contain several images, typically an OS
3768 (Linux) kernel image and one or more data images like
3769 RAMDisks. This construct is useful for instance when you want
3770 to boot over the network using BOOTP etc., where the boot
3771 server provides just a single image file, but you want to get
3772 for instance an OS kernel and a RAMDisk image.
3774 "Multi-File Images" start with a list of image sizes, each
3775 image size (in bytes) specified by an "uint32_t" in network
3776 byte order. This list is terminated by an "(uint32_t)0".
3777 Immediately after the terminating 0 follow the images, one by
3778 one, all aligned on "uint32_t" boundaries (size rounded up to
3779 a multiple of 4 bytes).
3781 "Firmware Images" are binary images containing firmware (like
3782 U-Boot or FPGA images) which usually will be programmed to
3785 "Script files" are command sequences that will be executed by
3786 U-Boot's command interpreter; this feature is especially
3787 useful when you configure U-Boot to use a real shell (hush)
3788 as command interpreter.
3794 One of the features of U-Boot is that you can dynamically load and
3795 run "standalone" applications, which can use some resources of
3796 U-Boot like console I/O functions or interrupt services.
3798 Two simple examples are included with the sources:
3803 'examples/hello_world.c' contains a small "Hello World" Demo
3804 application; it is automatically compiled when you build U-Boot.
3805 It's configured to run at address 0x00040004, so you can play with it
3809 ## Ready for S-Record download ...
3810 ~>examples/hello_world.srec
3811 1 2 3 4 5 6 7 8 9 10 11 ...
3812 [file transfer complete]
3814 ## Start Addr = 0x00040004
3816 => go 40004 Hello World! This is a test.
3817 ## Starting application at 0x00040004 ...
3828 Hit any key to exit ...
3830 ## Application terminated, rc = 0x0
3832 Another example, which demonstrates how to register a CPM interrupt
3833 handler with the U-Boot code, can be found in 'examples/timer.c'.
3834 Here, a CPM timer is set up to generate an interrupt every second.
3835 The interrupt service routine is trivial, just printing a '.'
3836 character, but this is just a demo program. The application can be
3837 controlled by the following keys:
3839 ? - print current values og the CPM Timer registers
3840 b - enable interrupts and start timer
3841 e - stop timer and disable interrupts
3842 q - quit application
3845 ## Ready for S-Record download ...
3846 ~>examples/timer.srec
3847 1 2 3 4 5 6 7 8 9 10 11 ...
3848 [file transfer complete]
3850 ## Start Addr = 0x00040004
3853 ## Starting application at 0x00040004 ...
3856 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
3859 [q, b, e, ?] Set interval 1000000 us
3862 [q, b, e, ?] ........
3863 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
3866 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
3869 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
3872 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
3874 [q, b, e, ?] ...Stopping timer
3876 [q, b, e, ?] ## Application terminated, rc = 0x0
3882 Over time, many people have reported problems when trying to use the
3883 "minicom" terminal emulation program for serial download. I (wd)
3884 consider minicom to be broken, and recommend not to use it. Under
3885 Unix, I recommend to use C-Kermit for general purpose use (and
3886 especially for kermit binary protocol download ("loadb" command), and
3887 use "cu" for S-Record download ("loads" command).
3889 Nevertheless, if you absolutely want to use it try adding this
3890 configuration to your "File transfer protocols" section:
3892 Name Program Name U/D FullScr IO-Red. Multi
3893 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
3894 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
3900 Starting at version 0.9.2, U-Boot supports NetBSD both as host
3901 (build U-Boot) and target system (boots NetBSD/mpc8xx).
3903 Building requires a cross environment; it is known to work on
3904 NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
3905 need gmake since the Makefiles are not compatible with BSD make).
3906 Note that the cross-powerpc package does not install include files;
3907 attempting to build U-Boot will fail because <machine/ansi.h> is
3908 missing. This file has to be installed and patched manually:
3910 # cd /usr/pkg/cross/powerpc-netbsd/include
3912 # ln -s powerpc machine
3913 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
3914 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
3916 Native builds *don't* work due to incompatibilities between native
3917 and U-Boot include files.
3919 Booting assumes that (the first part of) the image booted is a
3920 stage-2 loader which in turn loads and then invokes the kernel
3921 proper. Loader sources will eventually appear in the NetBSD source
3922 tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
3923 meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz
3926 Implementation Internals:
3927 =========================
3929 The following is not intended to be a complete description of every
3930 implementation detail. However, it should help to understand the
3931 inner workings of U-Boot and make it easier to port it to custom
3935 Initial Stack, Global Data:
3936 ---------------------------
3938 The implementation of U-Boot is complicated by the fact that U-Boot
3939 starts running out of ROM (flash memory), usually without access to
3940 system RAM (because the memory controller is not initialized yet).
3941 This means that we don't have writable Data or BSS segments, and BSS
3942 is not initialized as zero. To be able to get a C environment working
3943 at all, we have to allocate at least a minimal stack. Implementation
3944 options for this are defined and restricted by the CPU used: Some CPU
3945 models provide on-chip memory (like the IMMR area on MPC8xx and
3946 MPC826x processors), on others (parts of) the data cache can be
3947 locked as (mis-) used as memory, etc.
3949 Chris Hallinan posted a good summary of these issues to the
3950 U-Boot mailing list:
3952 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
3953 From: "Chris Hallinan" <clh@net1plus.com>
3954 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
3957 Correct me if I'm wrong, folks, but the way I understand it
3958 is this: Using DCACHE as initial RAM for Stack, etc, does not
3959 require any physical RAM backing up the cache. The cleverness
3960 is that the cache is being used as a temporary supply of
3961 necessary storage before the SDRAM controller is setup. It's
3962 beyond the scope of this list to explain the details, but you
3963 can see how this works by studying the cache architecture and
3964 operation in the architecture and processor-specific manuals.
3966 OCM is On Chip Memory, which I believe the 405GP has 4K. It
3967 is another option for the system designer to use as an
3968 initial stack/RAM area prior to SDRAM being available. Either
3969 option should work for you. Using CS 4 should be fine if your
3970 board designers haven't used it for something that would
3971 cause you grief during the initial boot! It is frequently not
3974 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere
3975 with your processor/board/system design. The default value
3976 you will find in any recent u-boot distribution in
3977 walnut.h should work for you. I'd set it to a value larger
3978 than your SDRAM module. If you have a 64MB SDRAM module, set
3979 it above 400_0000. Just make sure your board has no resources
3980 that are supposed to respond to that address! That code in
3981 start.S has been around a while and should work as is when
3982 you get the config right.
3987 It is essential to remember this, since it has some impact on the C
3988 code for the initialization procedures:
3990 * Initialized global data (data segment) is read-only. Do not attempt
3993 * Do not use any uninitialized global data (or implicitely initialized
3994 as zero data - BSS segment) at all - this is undefined, initiali-
3995 zation is performed later (when relocating to RAM).
3997 * Stack space is very limited. Avoid big data buffers or things like
4000 Having only the stack as writable memory limits means we cannot use
4001 normal global data to share information beween the code. But it
4002 turned out that the implementation of U-Boot can be greatly
4003 simplified by making a global data structure (gd_t) available to all
4004 functions. We could pass a pointer to this data as argument to _all_
4005 functions, but this would bloat the code. Instead we use a feature of
4006 the GCC compiler (Global Register Variables) to share the data: we
4007 place a pointer (gd) to the global data into a register which we
4008 reserve for this purpose.
4010 When choosing a register for such a purpose we are restricted by the
4011 relevant (E)ABI specifications for the current architecture, and by
4012 GCC's implementation.
4014 For PowerPC, the following registers have specific use:
4016 R2: reserved for system use
4017 R3-R4: parameter passing and return values
4018 R5-R10: parameter passing
4019 R13: small data area pointer
4023 (U-Boot also uses R12 as internal GOT pointer. r12
4024 is a volatile register so r12 needs to be reset when
4025 going back and forth between asm and C)
4027 ==> U-Boot will use R2 to hold a pointer to the global data
4029 Note: on PPC, we could use a static initializer (since the
4030 address of the global data structure is known at compile time),
4031 but it turned out that reserving a register results in somewhat
4032 smaller code - although the code savings are not that big (on
4033 average for all boards 752 bytes for the whole U-Boot image,
4034 624 text + 127 data).
4036 On Blackfin, the normal C ABI (except for P3) is followed as documented here:
4037 http://docs.blackfin.uclinux.org/doku.php?id=application_binary_interface
4039 ==> U-Boot will use P3 to hold a pointer to the global data
4041 On ARM, the following registers are used:
4043 R0: function argument word/integer result
4044 R1-R3: function argument word
4046 R10: stack limit (used only if stack checking if enabled)
4047 R11: argument (frame) pointer
4048 R12: temporary workspace
4051 R15: program counter
4053 ==> U-Boot will use R8 to hold a pointer to the global data
4055 On Nios II, the ABI is documented here:
4056 http://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf
4058 ==> U-Boot will use gp to hold a pointer to the global data
4060 Note: on Nios II, we give "-G0" option to gcc and don't use gp
4061 to access small data sections, so gp is free.
4063 NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope,
4064 or current versions of GCC may "optimize" the code too much.
4069 U-Boot runs in system state and uses physical addresses, i.e. the
4070 MMU is not used either for address mapping nor for memory protection.
4072 The available memory is mapped to fixed addresses using the memory
4073 controller. In this process, a contiguous block is formed for each
4074 memory type (Flash, SDRAM, SRAM), even when it consists of several
4075 physical memory banks.
4077 U-Boot is installed in the first 128 kB of the first Flash bank (on
4078 TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
4079 booting and sizing and initializing DRAM, the code relocates itself
4080 to the upper end of DRAM. Immediately below the U-Boot code some
4081 memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN
4082 configuration setting]. Below that, a structure with global Board
4083 Info data is placed, followed by the stack (growing downward).
4085 Additionally, some exception handler code is copied to the low 8 kB
4086 of DRAM (0x00000000 ... 0x00001FFF).
4088 So a typical memory configuration with 16 MB of DRAM could look like
4091 0x0000 0000 Exception Vector code
4094 0x0000 2000 Free for Application Use
4100 0x00FB FF20 Monitor Stack (Growing downward)
4101 0x00FB FFAC Board Info Data and permanent copy of global data
4102 0x00FC 0000 Malloc Arena
4105 0x00FE 0000 RAM Copy of Monitor Code
4106 ... eventually: LCD or video framebuffer
4107 ... eventually: pRAM (Protected RAM - unchanged by reset)
4108 0x00FF FFFF [End of RAM]
4111 System Initialization:
4112 ----------------------
4114 In the reset configuration, U-Boot starts at the reset entry point
4115 (on most PowerPC systems at address 0x00000100). Because of the reset
4116 configuration for CS0# this is a mirror of the onboard Flash memory.
4117 To be able to re-map memory U-Boot then jumps to its link address.
4118 To be able to implement the initialization code in C, a (small!)
4119 initial stack is set up in the internal Dual Ported RAM (in case CPUs
4120 which provide such a feature like MPC8xx or MPC8260), or in a locked
4121 part of the data cache. After that, U-Boot initializes the CPU core,
4122 the caches and the SIU.
4124 Next, all (potentially) available memory banks are mapped using a
4125 preliminary mapping. For example, we put them on 512 MB boundaries
4126 (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
4127 on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
4128 programmed for SDRAM access. Using the temporary configuration, a
4129 simple memory test is run that determines the size of the SDRAM
4132 When there is more than one SDRAM bank, and the banks are of
4133 different size, the largest is mapped first. For equal size, the first
4134 bank (CS2#) is mapped first. The first mapping is always for address
4135 0x00000000, with any additional banks following immediately to create
4136 contiguous memory starting from 0.
4138 Then, the monitor installs itself at the upper end of the SDRAM area
4139 and allocates memory for use by malloc() and for the global Board
4140 Info data; also, the exception vector code is copied to the low RAM
4141 pages, and the final stack is set up.
4143 Only after this relocation will you have a "normal" C environment;
4144 until that you are restricted in several ways, mostly because you are
4145 running from ROM, and because the code will have to be relocated to a
4149 U-Boot Porting Guide:
4150 ----------------------
4152 [Based on messages by Jerry Van Baren in the U-Boot-Users mailing
4156 int main(int argc, char *argv[])
4158 sighandler_t no_more_time;
4160 signal(SIGALRM, no_more_time);
4161 alarm(PROJECT_DEADLINE - toSec (3 * WEEK));
4163 if (available_money > available_manpower) {
4164 Pay consultant to port U-Boot;
4168 Download latest U-Boot source;
4170 Subscribe to u-boot mailing list;
4173 email("Hi, I am new to U-Boot, how do I get started?");
4176 Read the README file in the top level directory;
4177 Read http://www.denx.de/twiki/bin/view/DULG/Manual;
4178 Read applicable doc/*.README;
4179 Read the source, Luke;
4180 /* find . -name "*.[chS]" | xargs grep -i <keyword> */
4183 if (available_money > toLocalCurrency ($2500))
4186 Add a lot of aggravation and time;
4188 if (a similar board exists) { /* hopefully... */
4189 cp -a board/<similar> board/<myboard>
4190 cp include/configs/<similar>.h include/configs/<myboard>.h
4192 Create your own board support subdirectory;
4193 Create your own board include/configs/<myboard>.h file;
4195 Edit new board/<myboard> files
4196 Edit new include/configs/<myboard>.h
4201 Add / modify source code;
4205 email("Hi, I am having problems...");
4207 Send patch file to the U-Boot email list;
4208 if (reasonable critiques)
4209 Incorporate improvements from email list code review;
4211 Defend code as written;
4217 void no_more_time (int sig)
4226 All contributions to U-Boot should conform to the Linux kernel
4227 coding style; see the file "Documentation/CodingStyle" and the script
4228 "scripts/Lindent" in your Linux kernel source directory. In sources
4229 originating from U-Boot a style corresponding to "Lindent -pcs" (adding
4230 spaces before parameters to function calls) is actually used.
4232 Source files originating from a different project (for example the
4233 MTD subsystem) are generally exempt from these guidelines and are not
4234 reformated to ease subsequent migration to newer versions of those
4237 Please note that U-Boot is implemented in C (and to some small parts in
4238 Assembler); no C++ is used, so please do not use C++ style comments (//)
4241 Please also stick to the following formatting rules:
4242 - remove any trailing white space
4243 - use TAB characters for indentation, not spaces
4244 - make sure NOT to use DOS '\r\n' line feeds
4245 - do not add more than 2 empty lines to source files
4246 - do not add trailing empty lines to source files
4248 Submissions which do not conform to the standards may be returned
4249 with a request to reformat the changes.
4255 Since the number of patches for U-Boot is growing, we need to
4256 establish some rules. Submissions which do not conform to these rules
4257 may be rejected, even when they contain important and valuable stuff.
4259 Please see http://www.denx.de/wiki/U-Boot/Patches for details.
4261 Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>;
4262 see http://lists.denx.de/mailman/listinfo/u-boot
4264 When you send a patch, please include the following information with
4267 * For bug fixes: a description of the bug and how your patch fixes
4268 this bug. Please try to include a way of demonstrating that the
4269 patch actually fixes something.
4271 * For new features: a description of the feature and your
4274 * A CHANGELOG entry as plaintext (separate from the patch)
4276 * For major contributions, your entry to the CREDITS file
4278 * When you add support for a new board, don't forget to add this
4279 board to the MAKEALL script, too.
4281 * If your patch adds new configuration options, don't forget to
4282 document these in the README file.
4284 * The patch itself. If you are using git (which is *strongly*
4285 recommended) you can easily generate the patch using the
4286 "git-format-patch". If you then use "git-send-email" to send it to
4287 the U-Boot mailing list, you will avoid most of the common problems
4288 with some other mail clients.
4290 If you cannot use git, use "diff -purN OLD NEW". If your version of
4291 diff does not support these options, then get the latest version of
4294 The current directory when running this command shall be the parent
4295 directory of the U-Boot source tree (i. e. please make sure that
4296 your patch includes sufficient directory information for the
4299 We prefer patches as plain text. MIME attachments are discouraged,
4300 and compressed attachments must not be used.
4302 * If one logical set of modifications affects or creates several
4303 files, all these changes shall be submitted in a SINGLE patch file.
4305 * Changesets that contain different, unrelated modifications shall be
4306 submitted as SEPARATE patches, one patch per changeset.
4311 * Before sending the patch, run the MAKEALL script on your patched
4312 source tree and make sure that no errors or warnings are reported
4313 for any of the boards.
4315 * Keep your modifications to the necessary minimum: A patch
4316 containing several unrelated changes or arbitrary reformats will be
4317 returned with a request to re-formatting / split it.
4319 * If you modify existing code, make sure that your new code does not
4320 add to the memory footprint of the code ;-) Small is beautiful!
4321 When adding new features, these should compile conditionally only
4322 (using #ifdef), and the resulting code with the new feature
4323 disabled must not need more memory than the old code without your
4326 * Remember that there is a size limit of 100 kB per message on the
4327 u-boot mailing list. Bigger patches will be moderated. If they are
4328 reasonable and not too big, they will be acknowledged. But patches
4329 bigger than the size limit should be avoided.
projects / karo-tx-uboot.git / blob