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 Note that if the GPIO device uses I2C, then the I2C interface
750 must also be configured. See I2C Support, below.
754 When CONFIG_TIMESTAMP is selected, the timestamp
755 (date and time) of an image is printed by image
756 commands like bootm or iminfo. This option is
757 automatically enabled when you select CONFIG_CMD_DATE .
760 CONFIG_MAC_PARTITION and/or CONFIG_DOS_PARTITION
761 and/or CONFIG_ISO_PARTITION and/or CONFIG_EFI_PARTITION
763 If IDE or SCSI support is enabled (CONFIG_CMD_IDE or
764 CONFIG_CMD_SCSI) you must configure support for at
765 least one partition type as well.
768 CONFIG_IDE_RESET_ROUTINE - this is defined in several
769 board configurations files but used nowhere!
771 CONFIG_IDE_RESET - is this is defined, IDE Reset will
772 be performed by calling the function
773 ide_set_reset(int reset)
774 which has to be defined in a board specific file
779 Set this to enable ATAPI support.
784 Set this to enable support for disks larger than 137GB
785 Also look at CONFIG_SYS_64BIT_LBA.
786 Whithout these , LBA48 support uses 32bit variables and will 'only'
787 support disks up to 2.1TB.
789 CONFIG_SYS_64BIT_LBA:
790 When enabled, makes the IDE subsystem use 64bit sector addresses.
794 At the moment only there is only support for the
795 SYM53C8XX SCSI controller; define
796 CONFIG_SCSI_SYM53C8XX to enable it.
798 CONFIG_SYS_SCSI_MAX_LUN [8], CONFIG_SYS_SCSI_MAX_SCSI_ID [7] and
799 CONFIG_SYS_SCSI_MAX_DEVICE [CONFIG_SYS_SCSI_MAX_SCSI_ID *
800 CONFIG_SYS_SCSI_MAX_LUN] can be adjusted to define the
801 maximum numbers of LUNs, SCSI ID's and target
803 CONFIG_SYS_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz)
805 - NETWORK Support (PCI):
807 Support for Intel 8254x gigabit chips.
809 CONFIG_E1000_FALLBACK_MAC
810 default MAC for empty EEPROM after production.
813 Support for Intel 82557/82559/82559ER chips.
814 Optional CONFIG_EEPRO100_SROM_WRITE enables EEPROM
815 write routine for first time initialisation.
818 Support for Digital 2114x chips.
819 Optional CONFIG_TULIP_SELECT_MEDIA for board specific
820 modem chip initialisation (KS8761/QS6611).
823 Support for National dp83815 chips.
826 Support for National dp8382[01] gigabit chips.
828 - NETWORK Support (other):
830 CONFIG_DRIVER_AT91EMAC
831 Support for AT91RM9200 EMAC.
834 Define this to use reduced MII inteface
836 CONFIG_DRIVER_AT91EMAC_QUIET
837 If this defined, the driver is quiet.
838 The driver doen't show link status messages.
840 CONFIG_DRIVER_LAN91C96
841 Support for SMSC's LAN91C96 chips.
844 Define this to hold the physical address
845 of the LAN91C96's I/O space
847 CONFIG_LAN91C96_USE_32_BIT
848 Define this to enable 32 bit addressing
850 CONFIG_DRIVER_SMC91111
851 Support for SMSC's LAN91C111 chip
854 Define this to hold the physical address
855 of the device (I/O space)
857 CONFIG_SMC_USE_32_BIT
858 Define this if data bus is 32 bits
860 CONFIG_SMC_USE_IOFUNCS
861 Define this to use i/o functions instead of macros
862 (some hardware wont work with macros)
865 Support for Faraday's FTGMAC100 Gigabit SoC Ethernet
867 CONFIG_FTGMAC100_EGIGA
868 Define this to use GE link update with gigabit PHY.
869 Define this if FTGMAC100 is connected to gigabit PHY.
870 If your system has 10/100 PHY only, it might not occur
871 wrong behavior. Because PHY usually return timeout or
872 useless data when polling gigabit status and gigabit
873 control registers. This behavior won't affect the
874 correctnessof 10/100 link speed update.
877 Support for SMSC's LAN911x and LAN921x chips
880 Define this to hold the physical address
881 of the device (I/O space)
883 CONFIG_SMC911X_32_BIT
884 Define this if data bus is 32 bits
886 CONFIG_SMC911X_16_BIT
887 Define this if data bus is 16 bits. If your processor
888 automatically converts one 32 bit word to two 16 bit
889 words you may also try CONFIG_SMC911X_32_BIT.
892 At the moment only the UHCI host controller is
893 supported (PIP405, MIP405, MPC5200); define
894 CONFIG_USB_UHCI to enable it.
895 define CONFIG_USB_KEYBOARD to enable the USB Keyboard
896 and define CONFIG_USB_STORAGE to enable the USB
899 Supported are USB Keyboards and USB Floppy drives
901 MPC5200 USB requires additional defines:
903 for 528 MHz Clock: 0x0001bbbb
907 for differential drivers: 0x00001000
908 for single ended drivers: 0x00005000
909 for differential drivers on PSC3: 0x00000100
910 for single ended drivers on PSC3: 0x00004100
911 CONFIG_SYS_USB_EVENT_POLL
912 May be defined to allow interrupt polling
913 instead of using asynchronous interrupts
916 Define the below if you wish to use the USB console.
917 Once firmware is rebuilt from a serial console issue the
918 command "setenv stdin usbtty; setenv stdout usbtty" and
919 attach your USB cable. The Unix command "dmesg" should print
920 it has found a new device. The environment variable usbtty
921 can be set to gserial or cdc_acm to enable your device to
922 appear to a USB host as a Linux gserial device or a
923 Common Device Class Abstract Control Model serial device.
924 If you select usbtty = gserial you should be able to enumerate
926 # modprobe usbserial vendor=0xVendorID product=0xProductID
927 else if using cdc_acm, simply setting the environment
928 variable usbtty to be cdc_acm should suffice. The following
929 might be defined in YourBoardName.h
932 Define this to build a UDC device
935 Define this to have a tty type of device available to
936 talk to the UDC device
938 CONFIG_SYS_CONSOLE_IS_IN_ENV
939 Define this if you want stdin, stdout &/or stderr to
943 CONFIG_SYS_USB_EXTC_CLK 0xBLAH
944 Derive USB clock from external clock "blah"
945 - CONFIG_SYS_USB_EXTC_CLK 0x02
947 CONFIG_SYS_USB_BRG_CLK 0xBLAH
948 Derive USB clock from brgclk
949 - CONFIG_SYS_USB_BRG_CLK 0x04
951 If you have a USB-IF assigned VendorID then you may wish to
952 define your own vendor specific values either in BoardName.h
953 or directly in usbd_vendor_info.h. If you don't define
954 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME,
955 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot
956 should pretend to be a Linux device to it's target host.
958 CONFIG_USBD_MANUFACTURER
959 Define this string as the name of your company for
960 - CONFIG_USBD_MANUFACTURER "my company"
962 CONFIG_USBD_PRODUCT_NAME
963 Define this string as the name of your product
964 - CONFIG_USBD_PRODUCT_NAME "acme usb device"
967 Define this as your assigned Vendor ID from the USB
968 Implementors Forum. This *must* be a genuine Vendor ID
969 to avoid polluting the USB namespace.
970 - CONFIG_USBD_VENDORID 0xFFFF
972 CONFIG_USBD_PRODUCTID
973 Define this as the unique Product ID
975 - CONFIG_USBD_PRODUCTID 0xFFFF
979 The MMC controller on the Intel PXA is supported. To
980 enable this define CONFIG_MMC. The MMC can be
981 accessed from the boot prompt by mapping the device
982 to physical memory similar to flash. Command line is
983 enabled with CONFIG_CMD_MMC. The MMC driver also works with
984 the FAT fs. This is enabled with CONFIG_CMD_FAT.
986 - Journaling Flash filesystem support:
987 CONFIG_JFFS2_NAND, CONFIG_JFFS2_NAND_OFF, CONFIG_JFFS2_NAND_SIZE,
988 CONFIG_JFFS2_NAND_DEV
989 Define these for a default partition on a NAND device
991 CONFIG_SYS_JFFS2_FIRST_SECTOR,
992 CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS
993 Define these for a default partition on a NOR device
995 CONFIG_SYS_JFFS_CUSTOM_PART
996 Define this to create an own partition. You have to provide a
997 function struct part_info* jffs2_part_info(int part_num)
999 If you define only one JFFS2 partition you may also want to
1000 #define CONFIG_SYS_JFFS_SINGLE_PART 1
1001 to disable the command chpart. This is the default when you
1002 have not defined a custom partition
1007 Define this to enable standard (PC-Style) keyboard
1011 Standard PC keyboard driver with US (is default) and
1012 GERMAN key layout (switch via environment 'keymap=de') support.
1013 Export function i8042_kbd_init, i8042_tstc and i8042_getc
1014 for cfb_console. Supports cursor blinking.
1019 Define this to enable video support (for output to
1022 CONFIG_VIDEO_CT69000
1024 Enable Chips & Technologies 69000 Video chip
1026 CONFIG_VIDEO_SMI_LYNXEM
1027 Enable Silicon Motion SMI 712/710/810 Video chip. The
1028 video output is selected via environment 'videoout'
1029 (1 = LCD and 2 = CRT). If videoout is undefined, CRT is
1032 For the CT69000 and SMI_LYNXEM drivers, videomode is
1033 selected via environment 'videomode'. Two different ways
1035 - "videomode=num" 'num' is a standard LiLo mode numbers.
1036 Following standard modes are supported (* is default):
1038 Colors 640x480 800x600 1024x768 1152x864 1280x1024
1039 -------------+---------------------------------------------
1040 8 bits | 0x301* 0x303 0x305 0x161 0x307
1041 15 bits | 0x310 0x313 0x316 0x162 0x319
1042 16 bits | 0x311 0x314 0x317 0x163 0x31A
1043 24 bits | 0x312 0x315 0x318 ? 0x31B
1044 -------------+---------------------------------------------
1045 (i.e. setenv videomode 317; saveenv; reset;)
1047 - "videomode=bootargs" all the video parameters are parsed
1048 from the bootargs. (See drivers/video/videomodes.c)
1051 CONFIG_VIDEO_SED13806
1052 Enable Epson SED13806 driver. This driver supports 8bpp
1053 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP
1054 or CONFIG_VIDEO_SED13806_16BPP
1059 Define this to enable a custom keyboard support.
1060 This simply calls drv_keyboard_init() which must be
1061 defined in your board-specific files.
1062 The only board using this so far is RBC823.
1064 - LCD Support: CONFIG_LCD
1066 Define this to enable LCD support (for output to LCD
1067 display); also select one of the supported displays
1068 by defining one of these:
1072 HITACHI TX09D70VM1CCA, 3.5", 240x320.
1074 CONFIG_NEC_NL6448AC33:
1076 NEC NL6448AC33-18. Active, color, single scan.
1078 CONFIG_NEC_NL6448BC20
1080 NEC NL6448BC20-08. 6.5", 640x480.
1081 Active, color, single scan.
1083 CONFIG_NEC_NL6448BC33_54
1085 NEC NL6448BC33-54. 10.4", 640x480.
1086 Active, color, single scan.
1090 Sharp 320x240. Active, color, single scan.
1091 It isn't 16x9, and I am not sure what it is.
1093 CONFIG_SHARP_LQ64D341
1095 Sharp LQ64D341 display, 640x480.
1096 Active, color, single scan.
1100 HLD1045 display, 640x480.
1101 Active, color, single scan.
1105 Optrex CBL50840-2 NF-FW 99 22 M5
1107 Hitachi LMG6912RPFC-00T
1111 320x240. Black & white.
1113 Normally display is black on white background; define
1114 CONFIG_SYS_WHITE_ON_BLACK to get it inverted.
1116 - Splash Screen Support: CONFIG_SPLASH_SCREEN
1118 If this option is set, the environment is checked for
1119 a variable "splashimage". If found, the usual display
1120 of logo, copyright and system information on the LCD
1121 is suppressed and the BMP image at the address
1122 specified in "splashimage" is loaded instead. The
1123 console is redirected to the "nulldev", too. This
1124 allows for a "silent" boot where a splash screen is
1125 loaded very quickly after power-on.
1127 CONFIG_SPLASH_SCREEN_ALIGN
1129 If this option is set the splash image can be freely positioned
1130 on the screen. Environment variable "splashpos" specifies the
1131 position as "x,y". If a positive number is given it is used as
1132 number of pixel from left/top. If a negative number is given it
1133 is used as number of pixel from right/bottom. You can also
1134 specify 'm' for centering the image.
1137 setenv splashpos m,m
1138 => image at center of screen
1140 setenv splashpos 30,20
1141 => image at x = 30 and y = 20
1143 setenv splashpos -10,m
1144 => vertically centered image
1145 at x = dspWidth - bmpWidth - 9
1147 - Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP
1149 If this option is set, additionally to standard BMP
1150 images, gzipped BMP images can be displayed via the
1151 splashscreen support or the bmp command.
1153 - Run length encoded BMP image (RLE8) support: CONFIG_VIDEO_BMP_RLE8
1155 If this option is set, 8-bit RLE compressed BMP images
1156 can be displayed via the splashscreen support or the
1159 - Compression support:
1162 If this option is set, support for bzip2 compressed
1163 images is included. If not, only uncompressed and gzip
1164 compressed images are supported.
1166 NOTE: the bzip2 algorithm requires a lot of RAM, so
1167 the malloc area (as defined by CONFIG_SYS_MALLOC_LEN) should
1172 If this option is set, support for lzma compressed
1175 Note: The LZMA algorithm adds between 2 and 4KB of code and it
1176 requires an amount of dynamic memory that is given by the
1179 (1846 + 768 << (lc + lp)) * sizeof(uint16)
1181 Where lc and lp stand for, respectively, Literal context bits
1182 and Literal pos bits.
1184 This value is upper-bounded by 14MB in the worst case. Anyway,
1185 for a ~4MB large kernel image, we have lc=3 and lp=0 for a
1186 total amount of (1846 + 768 << (3 + 0)) * 2 = ~41KB... that is
1187 a very small buffer.
1189 Use the lzmainfo tool to determinate the lc and lp values and
1190 then calculate the amount of needed dynamic memory (ensuring
1191 the appropriate CONFIG_SYS_MALLOC_LEN value).
1196 The address of PHY on MII bus.
1198 CONFIG_PHY_CLOCK_FREQ (ppc4xx)
1200 The clock frequency of the MII bus
1204 If this option is set, support for speed/duplex
1205 detection of gigabit PHY is included.
1207 CONFIG_PHY_RESET_DELAY
1209 Some PHY like Intel LXT971A need extra delay after
1210 reset before any MII register access is possible.
1211 For such PHY, set this option to the usec delay
1212 required. (minimum 300usec for LXT971A)
1214 CONFIG_PHY_CMD_DELAY (ppc4xx)
1216 Some PHY like Intel LXT971A need extra delay after
1217 command issued before MII status register can be read
1227 Define a default value for Ethernet address to use
1228 for the respective Ethernet interface, in case this
1229 is not determined automatically.
1234 Define a default value for the IP address to use for
1235 the default Ethernet interface, in case this is not
1236 determined through e.g. bootp.
1238 - Server IP address:
1241 Defines a default value for the IP address of a TFTP
1242 server to contact when using the "tftboot" command.
1244 CONFIG_KEEP_SERVERADDR
1246 Keeps the server's MAC address, in the env 'serveraddr'
1247 for passing to bootargs (like Linux's netconsole option)
1249 - Multicast TFTP Mode:
1252 Defines whether you want to support multicast TFTP as per
1253 rfc-2090; for example to work with atftp. Lets lots of targets
1254 tftp down the same boot image concurrently. Note: the Ethernet
1255 driver in use must provide a function: mcast() to join/leave a
1258 CONFIG_BOOTP_RANDOM_DELAY
1259 - BOOTP Recovery Mode:
1260 CONFIG_BOOTP_RANDOM_DELAY
1262 If you have many targets in a network that try to
1263 boot using BOOTP, you may want to avoid that all
1264 systems send out BOOTP requests at precisely the same
1265 moment (which would happen for instance at recovery
1266 from a power failure, when all systems will try to
1267 boot, thus flooding the BOOTP server. Defining
1268 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
1269 inserted before sending out BOOTP requests. The
1270 following delays are inserted then:
1272 1st BOOTP request: delay 0 ... 1 sec
1273 2nd BOOTP request: delay 0 ... 2 sec
1274 3rd BOOTP request: delay 0 ... 4 sec
1276 BOOTP requests: delay 0 ... 8 sec
1278 - DHCP Advanced Options:
1279 You can fine tune the DHCP functionality by defining
1280 CONFIG_BOOTP_* symbols:
1282 CONFIG_BOOTP_SUBNETMASK
1283 CONFIG_BOOTP_GATEWAY
1284 CONFIG_BOOTP_HOSTNAME
1285 CONFIG_BOOTP_NISDOMAIN
1286 CONFIG_BOOTP_BOOTPATH
1287 CONFIG_BOOTP_BOOTFILESIZE
1290 CONFIG_BOOTP_SEND_HOSTNAME
1291 CONFIG_BOOTP_NTPSERVER
1292 CONFIG_BOOTP_TIMEOFFSET
1293 CONFIG_BOOTP_VENDOREX
1295 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip
1296 environment variable, not the BOOTP server.
1298 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS
1299 serverip from a DHCP server, it is possible that more
1300 than one DNS serverip is offered to the client.
1301 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS
1302 serverip will be stored in the additional environment
1303 variable "dnsip2". The first DNS serverip is always
1304 stored in the variable "dnsip", when CONFIG_BOOTP_DNS
1307 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable
1308 to do a dynamic update of a DNS server. To do this, they
1309 need the hostname of the DHCP requester.
1310 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content
1311 of the "hostname" environment variable is passed as
1312 option 12 to the DHCP server.
1314 CONFIG_BOOTP_DHCP_REQUEST_DELAY
1316 A 32bit value in microseconds for a delay between
1317 receiving a "DHCP Offer" and sending the "DHCP Request".
1318 This fixes a problem with certain DHCP servers that don't
1319 respond 100% of the time to a "DHCP request". E.g. On an
1320 AT91RM9200 processor running at 180MHz, this delay needed
1321 to be *at least* 15,000 usec before a Windows Server 2003
1322 DHCP server would reply 100% of the time. I recommend at
1323 least 50,000 usec to be safe. The alternative is to hope
1324 that one of the retries will be successful but note that
1325 the DHCP timeout and retry process takes a longer than
1329 CONFIG_CDP_DEVICE_ID
1331 The device id used in CDP trigger frames.
1333 CONFIG_CDP_DEVICE_ID_PREFIX
1335 A two character string which is prefixed to the MAC address
1340 A printf format string which contains the ascii name of
1341 the port. Normally is set to "eth%d" which sets
1342 eth0 for the first Ethernet, eth1 for the second etc.
1344 CONFIG_CDP_CAPABILITIES
1346 A 32bit integer which indicates the device capabilities;
1347 0x00000010 for a normal host which does not forwards.
1351 An ascii string containing the version of the software.
1355 An ascii string containing the name of the platform.
1359 A 32bit integer sent on the trigger.
1361 CONFIG_CDP_POWER_CONSUMPTION
1363 A 16bit integer containing the power consumption of the
1364 device in .1 of milliwatts.
1366 CONFIG_CDP_APPLIANCE_VLAN_TYPE
1368 A byte containing the id of the VLAN.
1370 - Status LED: CONFIG_STATUS_LED
1372 Several configurations allow to display the current
1373 status using a LED. For instance, the LED will blink
1374 fast while running U-Boot code, stop blinking as
1375 soon as a reply to a BOOTP request was received, and
1376 start blinking slow once the Linux kernel is running
1377 (supported by a status LED driver in the Linux
1378 kernel). Defining CONFIG_STATUS_LED enables this
1381 - CAN Support: CONFIG_CAN_DRIVER
1383 Defining CONFIG_CAN_DRIVER enables CAN driver support
1384 on those systems that support this (optional)
1385 feature, like the TQM8xxL modules.
1387 - I2C Support: CONFIG_HARD_I2C | CONFIG_SOFT_I2C
1389 These enable I2C serial bus commands. Defining either of
1390 (but not both of) CONFIG_HARD_I2C or CONFIG_SOFT_I2C will
1391 include the appropriate I2C driver for the selected CPU.
1393 This will allow you to use i2c commands at the u-boot
1394 command line (as long as you set CONFIG_CMD_I2C in
1395 CONFIG_COMMANDS) and communicate with i2c based realtime
1396 clock chips. See common/cmd_i2c.c for a description of the
1397 command line interface.
1399 CONFIG_HARD_I2C selects a hardware I2C controller.
1401 CONFIG_SOFT_I2C configures u-boot to use a software (aka
1402 bit-banging) driver instead of CPM or similar hardware
1405 There are several other quantities that must also be
1406 defined when you define CONFIG_HARD_I2C or CONFIG_SOFT_I2C.
1408 In both cases you will need to define CONFIG_SYS_I2C_SPEED
1409 to be the frequency (in Hz) at which you wish your i2c bus
1410 to run and CONFIG_SYS_I2C_SLAVE to be the address of this node (ie
1411 the CPU's i2c node address).
1413 Now, the u-boot i2c code for the mpc8xx
1414 (arch/powerpc/cpu/mpc8xx/i2c.c) sets the CPU up as a master node
1415 and so its address should therefore be cleared to 0 (See,
1416 eg, MPC823e User's Manual p.16-473). So, set
1417 CONFIG_SYS_I2C_SLAVE to 0.
1419 CONFIG_SYS_I2C_INIT_MPC5XXX
1421 When a board is reset during an i2c bus transfer
1422 chips might think that the current transfer is still
1423 in progress. Reset the slave devices by sending start
1424 commands until the slave device responds.
1426 That's all that's required for CONFIG_HARD_I2C.
1428 If you use the software i2c interface (CONFIG_SOFT_I2C)
1429 then the following macros need to be defined (examples are
1430 from include/configs/lwmon.h):
1434 (Optional). Any commands necessary to enable the I2C
1435 controller or configure ports.
1437 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
1441 (Only for MPC8260 CPU). The I/O port to use (the code
1442 assumes both bits are on the same port). Valid values
1443 are 0..3 for ports A..D.
1447 The code necessary to make the I2C data line active
1448 (driven). If the data line is open collector, this
1451 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
1455 The code necessary to make the I2C data line tri-stated
1456 (inactive). If the data line is open collector, this
1459 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
1463 Code that returns TRUE if the I2C data line is high,
1466 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
1470 If <bit> is TRUE, sets the I2C data line high. If it
1471 is FALSE, it clears it (low).
1473 eg: #define I2C_SDA(bit) \
1474 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
1475 else immr->im_cpm.cp_pbdat &= ~PB_SDA
1479 If <bit> is TRUE, sets the I2C clock line high. If it
1480 is FALSE, it clears it (low).
1482 eg: #define I2C_SCL(bit) \
1483 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
1484 else immr->im_cpm.cp_pbdat &= ~PB_SCL
1488 This delay is invoked four times per clock cycle so this
1489 controls the rate of data transfer. The data rate thus
1490 is 1 / (I2C_DELAY * 4). Often defined to be something
1493 #define I2C_DELAY udelay(2)
1495 CONFIG_SOFT_I2C_GPIO_SCL / CONFIG_SOFT_I2C_GPIO_SDA
1497 If your arch supports the generic GPIO framework (asm/gpio.h),
1498 then you may alternatively define the two GPIOs that are to be
1499 used as SCL / SDA. Any of the previous I2C_xxx macros will
1500 have GPIO-based defaults assigned to them as appropriate.
1502 You should define these to the GPIO value as given directly to
1503 the generic GPIO functions.
1505 CONFIG_SYS_I2C_INIT_BOARD
1507 When a board is reset during an i2c bus transfer
1508 chips might think that the current transfer is still
1509 in progress. On some boards it is possible to access
1510 the i2c SCLK line directly, either by using the
1511 processor pin as a GPIO or by having a second pin
1512 connected to the bus. If this option is defined a
1513 custom i2c_init_board() routine in boards/xxx/board.c
1514 is run early in the boot sequence.
1516 CONFIG_SYS_I2C_BOARD_LATE_INIT
1518 An alternative to CONFIG_SYS_I2C_INIT_BOARD. If this option is
1519 defined a custom i2c_board_late_init() routine in
1520 boards/xxx/board.c is run AFTER the operations in i2c_init()
1521 is completed. This callpoint can be used to unreset i2c bus
1522 using CPU i2c controller register accesses for CPUs whose i2c
1523 controller provide such a method. It is called at the end of
1524 i2c_init() to allow i2c_init operations to setup the i2c bus
1525 controller on the CPU (e.g. setting bus speed & slave address).
1527 CONFIG_I2CFAST (PPC405GP|PPC405EP only)
1529 This option enables configuration of bi_iic_fast[] flags
1530 in u-boot bd_info structure based on u-boot environment
1531 variable "i2cfast". (see also i2cfast)
1533 CONFIG_I2C_MULTI_BUS
1535 This option allows the use of multiple I2C buses, each of which
1536 must have a controller. At any point in time, only one bus is
1537 active. To switch to a different bus, use the 'i2c dev' command.
1538 Note that bus numbering is zero-based.
1540 CONFIG_SYS_I2C_NOPROBES
1542 This option specifies a list of I2C devices that will be skipped
1543 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS
1544 is set, specify a list of bus-device pairs. Otherwise, specify
1545 a 1D array of device addresses
1548 #undef CONFIG_I2C_MULTI_BUS
1549 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68}
1551 will skip addresses 0x50 and 0x68 on a board with one I2C bus
1553 #define CONFIG_I2C_MULTI_BUS
1554 #define CONFIG_SYS_I2C_MULTI_NOPROBES {{0,0x50},{0,0x68},{1,0x54}}
1556 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1
1558 CONFIG_SYS_SPD_BUS_NUM
1560 If defined, then this indicates the I2C bus number for DDR SPD.
1561 If not defined, then U-Boot assumes that SPD is on I2C bus 0.
1563 CONFIG_SYS_RTC_BUS_NUM
1565 If defined, then this indicates the I2C bus number for the RTC.
1566 If not defined, then U-Boot assumes that RTC is on I2C bus 0.
1568 CONFIG_SYS_DTT_BUS_NUM
1570 If defined, then this indicates the I2C bus number for the DTT.
1571 If not defined, then U-Boot assumes that DTT is on I2C bus 0.
1573 CONFIG_SYS_I2C_DTT_ADDR:
1575 If defined, specifies the I2C address of the DTT device.
1576 If not defined, then U-Boot uses predefined value for
1577 specified DTT device.
1581 Define this option if you want to use Freescale's I2C driver in
1582 drivers/i2c/fsl_i2c.c.
1586 Define this option if you have I2C devices reached over 1 .. n
1587 I2C Muxes like the pca9544a. This option addes a new I2C
1588 Command "i2c bus [muxtype:muxaddr:muxchannel]" which adds a
1589 new I2C Bus to the existing I2C Busses. If you select the
1590 new Bus with "i2c dev", u-bbot sends first the commandos for
1591 the muxes to activate this new "bus".
1593 CONFIG_I2C_MULTI_BUS must be also defined, to use this
1597 Adding a new I2C Bus reached over 2 pca9544a muxes
1598 The First mux with address 70 and channel 6
1599 The Second mux with address 71 and channel 4
1601 => i2c bus pca9544a:70:6:pca9544a:71:4
1603 Use the "i2c bus" command without parameter, to get a list
1604 of I2C Busses with muxes:
1607 Busses reached over muxes:
1609 reached over Mux(es):
1612 reached over Mux(es):
1617 If you now switch to the new I2C Bus 3 with "i2c dev 3"
1618 u-boot sends First the Commando to the mux@70 to enable
1619 channel 6, and then the Commando to the mux@71 to enable
1622 After that, you can use the "normal" i2c commands as
1623 usual, to communicate with your I2C devices behind
1626 This option is actually implemented for the bitbanging
1627 algorithm in common/soft_i2c.c and for the Hardware I2C
1628 Bus on the MPC8260. But it should be not so difficult
1629 to add this option to other architectures.
1631 CONFIG_SOFT_I2C_READ_REPEATED_START
1633 defining this will force the i2c_read() function in
1634 the soft_i2c driver to perform an I2C repeated start
1635 between writing the address pointer and reading the
1636 data. If this define is omitted the default behaviour
1637 of doing a stop-start sequence will be used. Most I2C
1638 devices can use either method, but some require one or
1641 - SPI Support: CONFIG_SPI
1643 Enables SPI driver (so far only tested with
1644 SPI EEPROM, also an instance works with Crystal A/D and
1645 D/As on the SACSng board)
1649 Enables extended (16-bit) SPI EEPROM addressing.
1650 (symmetrical to CONFIG_I2C_X)
1654 Enables a software (bit-bang) SPI driver rather than
1655 using hardware support. This is a general purpose
1656 driver that only requires three general I/O port pins
1657 (two outputs, one input) to function. If this is
1658 defined, the board configuration must define several
1659 SPI configuration items (port pins to use, etc). For
1660 an example, see include/configs/sacsng.h.
1664 Enables a hardware SPI driver for general-purpose reads
1665 and writes. As with CONFIG_SOFT_SPI, the board configuration
1666 must define a list of chip-select function pointers.
1667 Currently supported on some MPC8xxx processors. For an
1668 example, see include/configs/mpc8349emds.h.
1672 Enables the driver for the SPI controllers on i.MX and MXC
1673 SoCs. Currently only i.MX31 is supported.
1675 - FPGA Support: CONFIG_FPGA
1677 Enables FPGA subsystem.
1679 CONFIG_FPGA_<vendor>
1681 Enables support for specific chip vendors.
1684 CONFIG_FPGA_<family>
1686 Enables support for FPGA family.
1687 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX)
1691 Specify the number of FPGA devices to support.
1693 CONFIG_SYS_FPGA_PROG_FEEDBACK
1695 Enable printing of hash marks during FPGA configuration.
1697 CONFIG_SYS_FPGA_CHECK_BUSY
1699 Enable checks on FPGA configuration interface busy
1700 status by the configuration function. This option
1701 will require a board or device specific function to
1706 If defined, a function that provides delays in the FPGA
1707 configuration driver.
1709 CONFIG_SYS_FPGA_CHECK_CTRLC
1710 Allow Control-C to interrupt FPGA configuration
1712 CONFIG_SYS_FPGA_CHECK_ERROR
1714 Check for configuration errors during FPGA bitfile
1715 loading. For example, abort during Virtex II
1716 configuration if the INIT_B line goes low (which
1717 indicated a CRC error).
1719 CONFIG_SYS_FPGA_WAIT_INIT
1721 Maximum time to wait for the INIT_B line to deassert
1722 after PROB_B has been deasserted during a Virtex II
1723 FPGA configuration sequence. The default time is 500
1726 CONFIG_SYS_FPGA_WAIT_BUSY
1728 Maximum time to wait for BUSY to deassert during
1729 Virtex II FPGA configuration. The default is 5 ms.
1731 CONFIG_SYS_FPGA_WAIT_CONFIG
1733 Time to wait after FPGA configuration. The default is
1736 - Configuration Management:
1739 If defined, this string will be added to the U-Boot
1740 version information (U_BOOT_VERSION)
1742 - Vendor Parameter Protection:
1744 U-Boot considers the values of the environment
1745 variables "serial#" (Board Serial Number) and
1746 "ethaddr" (Ethernet Address) to be parameters that
1747 are set once by the board vendor / manufacturer, and
1748 protects these variables from casual modification by
1749 the user. Once set, these variables are read-only,
1750 and write or delete attempts are rejected. You can
1751 change this behaviour:
1753 If CONFIG_ENV_OVERWRITE is #defined in your config
1754 file, the write protection for vendor parameters is
1755 completely disabled. Anybody can change or delete
1758 Alternatively, if you #define _both_ CONFIG_ETHADDR
1759 _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
1760 Ethernet address is installed in the environment,
1761 which can be changed exactly ONCE by the user. [The
1762 serial# is unaffected by this, i. e. it remains
1768 Define this variable to enable the reservation of
1769 "protected RAM", i. e. RAM which is not overwritten
1770 by U-Boot. Define CONFIG_PRAM to hold the number of
1771 kB you want to reserve for pRAM. You can overwrite
1772 this default value by defining an environment
1773 variable "pram" to the number of kB you want to
1774 reserve. Note that the board info structure will
1775 still show the full amount of RAM. If pRAM is
1776 reserved, a new environment variable "mem" will
1777 automatically be defined to hold the amount of
1778 remaining RAM in a form that can be passed as boot
1779 argument to Linux, for instance like that:
1781 setenv bootargs ... mem=\${mem}
1784 This way you can tell Linux not to use this memory,
1785 either, which results in a memory region that will
1786 not be affected by reboots.
1788 *WARNING* If your board configuration uses automatic
1789 detection of the RAM size, you must make sure that
1790 this memory test is non-destructive. So far, the
1791 following board configurations are known to be
1794 ETX094, IVMS8, IVML24, SPD8xx, TQM8xxL,
1795 HERMES, IP860, RPXlite, LWMON, LANTEC,
1801 Define this variable to stop the system in case of a
1802 fatal error, so that you have to reset it manually.
1803 This is probably NOT a good idea for an embedded
1804 system where you want the system to reboot
1805 automatically as fast as possible, but it may be
1806 useful during development since you can try to debug
1807 the conditions that lead to the situation.
1809 CONFIG_NET_RETRY_COUNT
1811 This variable defines the number of retries for
1812 network operations like ARP, RARP, TFTP, or BOOTP
1813 before giving up the operation. If not defined, a
1814 default value of 5 is used.
1818 Timeout waiting for an ARP reply in milliseconds.
1820 - Command Interpreter:
1821 CONFIG_AUTO_COMPLETE
1823 Enable auto completion of commands using TAB.
1825 Note that this feature has NOT been implemented yet
1826 for the "hush" shell.
1829 CONFIG_SYS_HUSH_PARSER
1831 Define this variable to enable the "hush" shell (from
1832 Busybox) as command line interpreter, thus enabling
1833 powerful command line syntax like
1834 if...then...else...fi conditionals or `&&' and '||'
1835 constructs ("shell scripts").
1837 If undefined, you get the old, much simpler behaviour
1838 with a somewhat smaller memory footprint.
1841 CONFIG_SYS_PROMPT_HUSH_PS2
1843 This defines the secondary prompt string, which is
1844 printed when the command interpreter needs more input
1845 to complete a command. Usually "> ".
1849 In the current implementation, the local variables
1850 space and global environment variables space are
1851 separated. Local variables are those you define by
1852 simply typing `name=value'. To access a local
1853 variable later on, you have write `$name' or
1854 `${name}'; to execute the contents of a variable
1855 directly type `$name' at the command prompt.
1857 Global environment variables are those you use
1858 setenv/printenv to work with. To run a command stored
1859 in such a variable, you need to use the run command,
1860 and you must not use the '$' sign to access them.
1862 To store commands and special characters in a
1863 variable, please use double quotation marks
1864 surrounding the whole text of the variable, instead
1865 of the backslashes before semicolons and special
1868 - Commandline Editing and History:
1869 CONFIG_CMDLINE_EDITING
1871 Enable editing and History functions for interactive
1872 commandline input operations
1874 - Default Environment:
1875 CONFIG_EXTRA_ENV_SETTINGS
1877 Define this to contain any number of null terminated
1878 strings (variable = value pairs) that will be part of
1879 the default environment compiled into the boot image.
1881 For example, place something like this in your
1882 board's config file:
1884 #define CONFIG_EXTRA_ENV_SETTINGS \
1888 Warning: This method is based on knowledge about the
1889 internal format how the environment is stored by the
1890 U-Boot code. This is NOT an official, exported
1891 interface! Although it is unlikely that this format
1892 will change soon, there is no guarantee either.
1893 You better know what you are doing here.
1895 Note: overly (ab)use of the default environment is
1896 discouraged. Make sure to check other ways to preset
1897 the environment like the "source" command or the
1900 - DataFlash Support:
1901 CONFIG_HAS_DATAFLASH
1903 Defining this option enables DataFlash features and
1904 allows to read/write in Dataflash via the standard
1907 - SystemACE Support:
1910 Adding this option adds support for Xilinx SystemACE
1911 chips attached via some sort of local bus. The address
1912 of the chip must also be defined in the
1913 CONFIG_SYS_SYSTEMACE_BASE macro. For example:
1915 #define CONFIG_SYSTEMACE
1916 #define CONFIG_SYS_SYSTEMACE_BASE 0xf0000000
1918 When SystemACE support is added, the "ace" device type
1919 becomes available to the fat commands, i.e. fatls.
1921 - TFTP Fixed UDP Port:
1924 If this is defined, the environment variable tftpsrcp
1925 is used to supply the TFTP UDP source port value.
1926 If tftpsrcp isn't defined, the normal pseudo-random port
1927 number generator is used.
1929 Also, the environment variable tftpdstp is used to supply
1930 the TFTP UDP destination port value. If tftpdstp isn't
1931 defined, the normal port 69 is used.
1933 The purpose for tftpsrcp is to allow a TFTP server to
1934 blindly start the TFTP transfer using the pre-configured
1935 target IP address and UDP port. This has the effect of
1936 "punching through" the (Windows XP) firewall, allowing
1937 the remainder of the TFTP transfer to proceed normally.
1938 A better solution is to properly configure the firewall,
1939 but sometimes that is not allowed.
1941 - Show boot progress:
1942 CONFIG_SHOW_BOOT_PROGRESS
1944 Defining this option allows to add some board-
1945 specific code (calling a user-provided function
1946 "show_boot_progress(int)") that enables you to show
1947 the system's boot progress on some display (for
1948 example, some LED's) on your board. At the moment,
1949 the following checkpoints are implemented:
1951 Legacy uImage format:
1954 1 common/cmd_bootm.c before attempting to boot an image
1955 -1 common/cmd_bootm.c Image header has bad magic number
1956 2 common/cmd_bootm.c Image header has correct magic number
1957 -2 common/cmd_bootm.c Image header has bad checksum
1958 3 common/cmd_bootm.c Image header has correct checksum
1959 -3 common/cmd_bootm.c Image data has bad checksum
1960 4 common/cmd_bootm.c Image data has correct checksum
1961 -4 common/cmd_bootm.c Image is for unsupported architecture
1962 5 common/cmd_bootm.c Architecture check OK
1963 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi)
1964 6 common/cmd_bootm.c Image Type check OK
1965 -6 common/cmd_bootm.c gunzip uncompression error
1966 -7 common/cmd_bootm.c Unimplemented compression type
1967 7 common/cmd_bootm.c Uncompression OK
1968 8 common/cmd_bootm.c No uncompress/copy overwrite error
1969 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX)
1971 9 common/image.c Start initial ramdisk verification
1972 -10 common/image.c Ramdisk header has bad magic number
1973 -11 common/image.c Ramdisk header has bad checksum
1974 10 common/image.c Ramdisk header is OK
1975 -12 common/image.c Ramdisk data has bad checksum
1976 11 common/image.c Ramdisk data has correct checksum
1977 12 common/image.c Ramdisk verification complete, start loading
1978 -13 common/image.c Wrong Image Type (not PPC Linux ramdisk)
1979 13 common/image.c Start multifile image verification
1980 14 common/image.c No initial ramdisk, no multifile, continue.
1982 15 arch/<arch>/lib/bootm.c All preparation done, transferring control to OS
1984 -30 arch/powerpc/lib/board.c Fatal error, hang the system
1985 -31 post/post.c POST test failed, detected by post_output_backlog()
1986 -32 post/post.c POST test failed, detected by post_run_single()
1988 34 common/cmd_doc.c before loading a Image from a DOC device
1989 -35 common/cmd_doc.c Bad usage of "doc" command
1990 35 common/cmd_doc.c correct usage of "doc" command
1991 -36 common/cmd_doc.c No boot device
1992 36 common/cmd_doc.c correct boot device
1993 -37 common/cmd_doc.c Unknown Chip ID on boot device
1994 37 common/cmd_doc.c correct chip ID found, device available
1995 -38 common/cmd_doc.c Read Error on boot device
1996 38 common/cmd_doc.c reading Image header from DOC device OK
1997 -39 common/cmd_doc.c Image header has bad magic number
1998 39 common/cmd_doc.c Image header has correct magic number
1999 -40 common/cmd_doc.c Error reading Image from DOC device
2000 40 common/cmd_doc.c Image header has correct magic number
2001 41 common/cmd_ide.c before loading a Image from a IDE device
2002 -42 common/cmd_ide.c Bad usage of "ide" command
2003 42 common/cmd_ide.c correct usage of "ide" command
2004 -43 common/cmd_ide.c No boot device
2005 43 common/cmd_ide.c boot device found
2006 -44 common/cmd_ide.c Device not available
2007 44 common/cmd_ide.c Device available
2008 -45 common/cmd_ide.c wrong partition selected
2009 45 common/cmd_ide.c partition selected
2010 -46 common/cmd_ide.c Unknown partition table
2011 46 common/cmd_ide.c valid partition table found
2012 -47 common/cmd_ide.c Invalid partition type
2013 47 common/cmd_ide.c correct partition type
2014 -48 common/cmd_ide.c Error reading Image Header on boot device
2015 48 common/cmd_ide.c reading Image Header from IDE device OK
2016 -49 common/cmd_ide.c Image header has bad magic number
2017 49 common/cmd_ide.c Image header has correct magic number
2018 -50 common/cmd_ide.c Image header has bad checksum
2019 50 common/cmd_ide.c Image header has correct checksum
2020 -51 common/cmd_ide.c Error reading Image from IDE device
2021 51 common/cmd_ide.c reading Image from IDE device OK
2022 52 common/cmd_nand.c before loading a Image from a NAND device
2023 -53 common/cmd_nand.c Bad usage of "nand" command
2024 53 common/cmd_nand.c correct usage of "nand" command
2025 -54 common/cmd_nand.c No boot device
2026 54 common/cmd_nand.c boot device found
2027 -55 common/cmd_nand.c Unknown Chip ID on boot device
2028 55 common/cmd_nand.c correct chip ID found, device available
2029 -56 common/cmd_nand.c Error reading Image Header on boot device
2030 56 common/cmd_nand.c reading Image Header from NAND device OK
2031 -57 common/cmd_nand.c Image header has bad magic number
2032 57 common/cmd_nand.c Image header has correct magic number
2033 -58 common/cmd_nand.c Error reading Image from NAND device
2034 58 common/cmd_nand.c reading Image from NAND device OK
2036 -60 common/env_common.c Environment has a bad CRC, using default
2038 64 net/eth.c starting with Ethernet configuration.
2039 -64 net/eth.c no Ethernet found.
2040 65 net/eth.c Ethernet found.
2042 -80 common/cmd_net.c usage wrong
2043 80 common/cmd_net.c before calling NetLoop()
2044 -81 common/cmd_net.c some error in NetLoop() occurred
2045 81 common/cmd_net.c NetLoop() back without error
2046 -82 common/cmd_net.c size == 0 (File with size 0 loaded)
2047 82 common/cmd_net.c trying automatic boot
2048 83 common/cmd_net.c running "source" command
2049 -83 common/cmd_net.c some error in automatic boot or "source" command
2050 84 common/cmd_net.c end without errors
2055 100 common/cmd_bootm.c Kernel FIT Image has correct format
2056 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format
2057 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration
2058 -101 common/cmd_bootm.c Can't get configuration for kernel subimage
2059 102 common/cmd_bootm.c Kernel unit name specified
2060 -103 common/cmd_bootm.c Can't get kernel subimage node offset
2061 103 common/cmd_bootm.c Found configuration node
2062 104 common/cmd_bootm.c Got kernel subimage node offset
2063 -104 common/cmd_bootm.c Kernel subimage hash verification failed
2064 105 common/cmd_bootm.c Kernel subimage hash verification OK
2065 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture
2066 106 common/cmd_bootm.c Architecture check OK
2067 -106 common/cmd_bootm.c Kernel subimage has wrong type
2068 107 common/cmd_bootm.c Kernel subimage type OK
2069 -107 common/cmd_bootm.c Can't get kernel subimage data/size
2070 108 common/cmd_bootm.c Got kernel subimage data/size
2071 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT)
2072 -109 common/cmd_bootm.c Can't get kernel subimage type
2073 -110 common/cmd_bootm.c Can't get kernel subimage comp
2074 -111 common/cmd_bootm.c Can't get kernel subimage os
2075 -112 common/cmd_bootm.c Can't get kernel subimage load address
2076 -113 common/cmd_bootm.c Image uncompress/copy overwrite error
2078 120 common/image.c Start initial ramdisk verification
2079 -120 common/image.c Ramdisk FIT image has incorrect format
2080 121 common/image.c Ramdisk FIT image has correct format
2081 122 common/image.c No ramdisk subimage unit name, using configuration
2082 -122 common/image.c Can't get configuration for ramdisk subimage
2083 123 common/image.c Ramdisk unit name specified
2084 -124 common/image.c Can't get ramdisk subimage node offset
2085 125 common/image.c Got ramdisk subimage node offset
2086 -125 common/image.c Ramdisk subimage hash verification failed
2087 126 common/image.c Ramdisk subimage hash verification OK
2088 -126 common/image.c Ramdisk subimage for unsupported architecture
2089 127 common/image.c Architecture check OK
2090 -127 common/image.c Can't get ramdisk subimage data/size
2091 128 common/image.c Got ramdisk subimage data/size
2092 129 common/image.c Can't get ramdisk load address
2093 -129 common/image.c Got ramdisk load address
2095 -130 common/cmd_doc.c Incorrect FIT image format
2096 131 common/cmd_doc.c FIT image format OK
2098 -140 common/cmd_ide.c Incorrect FIT image format
2099 141 common/cmd_ide.c FIT image format OK
2101 -150 common/cmd_nand.c Incorrect FIT image format
2102 151 common/cmd_nand.c FIT image format OK
2104 - Automatic software updates via TFTP server
2106 CONFIG_UPDATE_TFTP_CNT_MAX
2107 CONFIG_UPDATE_TFTP_MSEC_MAX
2109 These options enable and control the auto-update feature;
2110 for a more detailed description refer to doc/README.update.
2112 - MTD Support (mtdparts command, UBI support)
2115 Adds the MTD device infrastructure from the Linux kernel.
2116 Needed for mtdparts command support.
2118 CONFIG_MTD_PARTITIONS
2120 Adds the MTD partitioning infrastructure from the Linux
2121 kernel. Needed for UBI support.
2127 [so far only for SMDK2400 and TRAB boards]
2129 - Modem support enable:
2130 CONFIG_MODEM_SUPPORT
2132 - RTS/CTS Flow control enable:
2135 - Modem debug support:
2136 CONFIG_MODEM_SUPPORT_DEBUG
2138 Enables debugging stuff (char screen[1024], dbg())
2139 for modem support. Useful only with BDI2000.
2141 - Interrupt support (PPC):
2143 There are common interrupt_init() and timer_interrupt()
2144 for all PPC archs. interrupt_init() calls interrupt_init_cpu()
2145 for CPU specific initialization. interrupt_init_cpu()
2146 should set decrementer_count to appropriate value. If
2147 CPU resets decrementer automatically after interrupt
2148 (ppc4xx) it should set decrementer_count to zero.
2149 timer_interrupt() calls timer_interrupt_cpu() for CPU
2150 specific handling. If board has watchdog / status_led
2151 / other_activity_monitor it works automatically from
2152 general timer_interrupt().
2156 In the target system modem support is enabled when a
2157 specific key (key combination) is pressed during
2158 power-on. Otherwise U-Boot will boot normally
2159 (autoboot). The key_pressed() function is called from
2160 board_init(). Currently key_pressed() is a dummy
2161 function, returning 1 and thus enabling modem
2164 If there are no modem init strings in the
2165 environment, U-Boot proceed to autoboot; the
2166 previous output (banner, info printfs) will be
2169 See also: doc/README.Modem
2172 Configuration Settings:
2173 -----------------------
2175 - CONFIG_SYS_LONGHELP: Defined when you want long help messages included;
2176 undefine this when you're short of memory.
2178 - CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default
2179 width of the commands listed in the 'help' command output.
2181 - CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to
2182 prompt for user input.
2184 - CONFIG_SYS_CBSIZE: Buffer size for input from the Console
2186 - CONFIG_SYS_PBSIZE: Buffer size for Console output
2188 - CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands
2190 - CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to
2191 the application (usually a Linux kernel) when it is
2194 - CONFIG_SYS_BAUDRATE_TABLE:
2195 List of legal baudrate settings for this board.
2197 - CONFIG_SYS_CONSOLE_INFO_QUIET
2198 Suppress display of console information at boot.
2200 - CONFIG_SYS_CONSOLE_IS_IN_ENV
2201 If the board specific function
2202 extern int overwrite_console (void);
2203 returns 1, the stdin, stderr and stdout are switched to the
2204 serial port, else the settings in the environment are used.
2206 - CONFIG_SYS_CONSOLE_OVERWRITE_ROUTINE
2207 Enable the call to overwrite_console().
2209 - CONFIG_SYS_CONSOLE_ENV_OVERWRITE
2210 Enable overwrite of previous console environment settings.
2212 - CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END:
2213 Begin and End addresses of the area used by the
2216 - CONFIG_SYS_ALT_MEMTEST:
2217 Enable an alternate, more extensive memory test.
2219 - CONFIG_SYS_MEMTEST_SCRATCH:
2220 Scratch address used by the alternate memory test
2221 You only need to set this if address zero isn't writeable
2223 - CONFIG_SYS_MEM_TOP_HIDE (PPC only):
2224 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header,
2225 this specified memory area will get subtracted from the top
2226 (end) of RAM and won't get "touched" at all by U-Boot. By
2227 fixing up gd->ram_size the Linux kernel should gets passed
2228 the now "corrected" memory size and won't touch it either.
2229 This should work for arch/ppc and arch/powerpc. Only Linux
2230 board ports in arch/powerpc with bootwrapper support that
2231 recalculate the memory size from the SDRAM controller setup
2232 will have to get fixed in Linux additionally.
2234 This option can be used as a workaround for the 440EPx/GRx
2235 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't
2238 WARNING: Please make sure that this value is a multiple of
2239 the Linux page size (normally 4k). If this is not the case,
2240 then the end address of the Linux memory will be located at a
2241 non page size aligned address and this could cause major
2244 - CONFIG_SYS_TFTP_LOADADDR:
2245 Default load address for network file downloads
2247 - CONFIG_SYS_LOADS_BAUD_CHANGE:
2248 Enable temporary baudrate change while serial download
2250 - CONFIG_SYS_SDRAM_BASE:
2251 Physical start address of SDRAM. _Must_ be 0 here.
2253 - CONFIG_SYS_MBIO_BASE:
2254 Physical start address of Motherboard I/O (if using a
2257 - CONFIG_SYS_FLASH_BASE:
2258 Physical start address of Flash memory.
2260 - CONFIG_SYS_MONITOR_BASE:
2261 Physical start address of boot monitor code (set by
2262 make config files to be same as the text base address
2263 (CONFIG_SYS_TEXT_BASE) used when linking) - same as
2264 CONFIG_SYS_FLASH_BASE when booting from flash.
2266 - CONFIG_SYS_MONITOR_LEN:
2267 Size of memory reserved for monitor code, used to
2268 determine _at_compile_time_ (!) if the environment is
2269 embedded within the U-Boot image, or in a separate
2272 - CONFIG_SYS_MALLOC_LEN:
2273 Size of DRAM reserved for malloc() use.
2275 - CONFIG_SYS_BOOTM_LEN:
2276 Normally compressed uImages are limited to an
2277 uncompressed size of 8 MBytes. If this is not enough,
2278 you can define CONFIG_SYS_BOOTM_LEN in your board config file
2279 to adjust this setting to your needs.
2281 - CONFIG_SYS_BOOTMAPSZ:
2282 Maximum size of memory mapped by the startup code of
2283 the Linux kernel; all data that must be processed by
2284 the Linux kernel (bd_info, boot arguments, FDT blob if
2285 used) must be put below this limit, unless "bootm_low"
2286 enviroment variable is defined and non-zero. In such case
2287 all data for the Linux kernel must be between "bootm_low"
2288 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ.
2290 - CONFIG_SYS_BOOT_RAMDISK_HIGH:
2291 Enable initrd_high functionality. If defined then the
2292 initrd_high feature is enabled and the bootm ramdisk subcommand
2295 - CONFIG_SYS_BOOT_GET_CMDLINE:
2296 Enables allocating and saving kernel cmdline in space between
2297 "bootm_low" and "bootm_low" + BOOTMAPSZ.
2299 - CONFIG_SYS_BOOT_GET_KBD:
2300 Enables allocating and saving a kernel copy of the bd_info in
2301 space between "bootm_low" and "bootm_low" + BOOTMAPSZ.
2303 - CONFIG_SYS_MAX_FLASH_BANKS:
2304 Max number of Flash memory banks
2306 - CONFIG_SYS_MAX_FLASH_SECT:
2307 Max number of sectors on a Flash chip
2309 - CONFIG_SYS_FLASH_ERASE_TOUT:
2310 Timeout for Flash erase operations (in ms)
2312 - CONFIG_SYS_FLASH_WRITE_TOUT:
2313 Timeout for Flash write operations (in ms)
2315 - CONFIG_SYS_FLASH_LOCK_TOUT
2316 Timeout for Flash set sector lock bit operation (in ms)
2318 - CONFIG_SYS_FLASH_UNLOCK_TOUT
2319 Timeout for Flash clear lock bits operation (in ms)
2321 - CONFIG_SYS_FLASH_PROTECTION
2322 If defined, hardware flash sectors protection is used
2323 instead of U-Boot software protection.
2325 - CONFIG_SYS_DIRECT_FLASH_TFTP:
2327 Enable TFTP transfers directly to flash memory;
2328 without this option such a download has to be
2329 performed in two steps: (1) download to RAM, and (2)
2330 copy from RAM to flash.
2332 The two-step approach is usually more reliable, since
2333 you can check if the download worked before you erase
2334 the flash, but in some situations (when system RAM is
2335 too limited to allow for a temporary copy of the
2336 downloaded image) this option may be very useful.
2338 - CONFIG_SYS_FLASH_CFI:
2339 Define if the flash driver uses extra elements in the
2340 common flash structure for storing flash geometry.
2342 - CONFIG_FLASH_CFI_DRIVER
2343 This option also enables the building of the cfi_flash driver
2344 in the drivers directory
2346 - CONFIG_FLASH_CFI_MTD
2347 This option enables the building of the cfi_mtd driver
2348 in the drivers directory. The driver exports CFI flash
2351 - CONFIG_SYS_FLASH_USE_BUFFER_WRITE
2352 Use buffered writes to flash.
2354 - CONFIG_FLASH_SPANSION_S29WS_N
2355 s29ws-n MirrorBit flash has non-standard addresses for buffered
2358 - CONFIG_SYS_FLASH_QUIET_TEST
2359 If this option is defined, the common CFI flash doesn't
2360 print it's warning upon not recognized FLASH banks. This
2361 is useful, if some of the configured banks are only
2362 optionally available.
2364 - CONFIG_FLASH_SHOW_PROGRESS
2365 If defined (must be an integer), print out countdown
2366 digits and dots. Recommended value: 45 (9..1) for 80
2367 column displays, 15 (3..1) for 40 column displays.
2369 - CONFIG_SYS_RX_ETH_BUFFER:
2370 Defines the number of Ethernet receive buffers. On some
2371 Ethernet controllers it is recommended to set this value
2372 to 8 or even higher (EEPRO100 or 405 EMAC), since all
2373 buffers can be full shortly after enabling the interface
2374 on high Ethernet traffic.
2375 Defaults to 4 if not defined.
2377 - CONFIG_ENV_MAX_ENTRIES
2379 Maximum number of entries in the hash table that is used
2380 internally to store the environment settings. The default
2381 setting is supposed to be generous and should work in most
2382 cases. This setting can be used to tune behaviour; see
2383 lib/hashtable.c for details.
2385 The following definitions that deal with the placement and management
2386 of environment data (variable area); in general, we support the
2387 following configurations:
2389 - CONFIG_ENV_IS_IN_FLASH:
2391 Define this if the environment is in flash memory.
2393 a) The environment occupies one whole flash sector, which is
2394 "embedded" in the text segment with the U-Boot code. This
2395 happens usually with "bottom boot sector" or "top boot
2396 sector" type flash chips, which have several smaller
2397 sectors at the start or the end. For instance, such a
2398 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In
2399 such a case you would place the environment in one of the
2400 4 kB sectors - with U-Boot code before and after it. With
2401 "top boot sector" type flash chips, you would put the
2402 environment in one of the last sectors, leaving a gap
2403 between U-Boot and the environment.
2405 - CONFIG_ENV_OFFSET:
2407 Offset of environment data (variable area) to the
2408 beginning of flash memory; for instance, with bottom boot
2409 type flash chips the second sector can be used: the offset
2410 for this sector is given here.
2412 CONFIG_ENV_OFFSET is used relative to CONFIG_SYS_FLASH_BASE.
2416 This is just another way to specify the start address of
2417 the flash sector containing the environment (instead of
2420 - CONFIG_ENV_SECT_SIZE:
2422 Size of the sector containing the environment.
2425 b) Sometimes flash chips have few, equal sized, BIG sectors.
2426 In such a case you don't want to spend a whole sector for
2431 If you use this in combination with CONFIG_ENV_IS_IN_FLASH
2432 and CONFIG_ENV_SECT_SIZE, you can specify to use only a part
2433 of this flash sector for the environment. This saves
2434 memory for the RAM copy of the environment.
2436 It may also save flash memory if you decide to use this
2437 when your environment is "embedded" within U-Boot code,
2438 since then the remainder of the flash sector could be used
2439 for U-Boot code. It should be pointed out that this is
2440 STRONGLY DISCOURAGED from a robustness point of view:
2441 updating the environment in flash makes it always
2442 necessary to erase the WHOLE sector. If something goes
2443 wrong before the contents has been restored from a copy in
2444 RAM, your target system will be dead.
2446 - CONFIG_ENV_ADDR_REDUND
2447 CONFIG_ENV_SIZE_REDUND
2449 These settings describe a second storage area used to hold
2450 a redundant copy of the environment data, so that there is
2451 a valid backup copy in case there is a power failure during
2452 a "saveenv" operation.
2454 BE CAREFUL! Any changes to the flash layout, and some changes to the
2455 source code will make it necessary to adapt <board>/u-boot.lds*
2459 - CONFIG_ENV_IS_IN_NVRAM:
2461 Define this if you have some non-volatile memory device
2462 (NVRAM, battery buffered SRAM) which you want to use for the
2468 These two #defines are used to determine the memory area you
2469 want to use for environment. It is assumed that this memory
2470 can just be read and written to, without any special
2473 BE CAREFUL! The first access to the environment happens quite early
2474 in U-Boot initalization (when we try to get the setting of for the
2475 console baudrate). You *MUST* have mapped your NVRAM area then, or
2478 Please note that even with NVRAM we still use a copy of the
2479 environment in RAM: we could work on NVRAM directly, but we want to
2480 keep settings there always unmodified except somebody uses "saveenv"
2481 to save the current settings.
2484 - CONFIG_ENV_IS_IN_EEPROM:
2486 Use this if you have an EEPROM or similar serial access
2487 device and a driver for it.
2489 - CONFIG_ENV_OFFSET:
2492 These two #defines specify the offset and size of the
2493 environment area within the total memory of your EEPROM.
2495 - CONFIG_SYS_I2C_EEPROM_ADDR:
2496 If defined, specified the chip address of the EEPROM device.
2497 The default address is zero.
2499 - CONFIG_SYS_EEPROM_PAGE_WRITE_BITS:
2500 If defined, the number of bits used to address bytes in a
2501 single page in the EEPROM device. A 64 byte page, for example
2502 would require six bits.
2504 - CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS:
2505 If defined, the number of milliseconds to delay between
2506 page writes. The default is zero milliseconds.
2508 - CONFIG_SYS_I2C_EEPROM_ADDR_LEN:
2509 The length in bytes of the EEPROM memory array address. Note
2510 that this is NOT the chip address length!
2512 - CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW:
2513 EEPROM chips that implement "address overflow" are ones
2514 like Catalyst 24WC04/08/16 which has 9/10/11 bits of
2515 address and the extra bits end up in the "chip address" bit
2516 slots. This makes a 24WC08 (1Kbyte) chip look like four 256
2519 Note that we consider the length of the address field to
2520 still be one byte because the extra address bits are hidden
2521 in the chip address.
2523 - CONFIG_SYS_EEPROM_SIZE:
2524 The size in bytes of the EEPROM device.
2526 - CONFIG_ENV_EEPROM_IS_ON_I2C
2527 define this, if you have I2C and SPI activated, and your
2528 EEPROM, which holds the environment, is on the I2C bus.
2530 - CONFIG_I2C_ENV_EEPROM_BUS
2531 if you have an Environment on an EEPROM reached over
2532 I2C muxes, you can define here, how to reach this
2533 EEPROM. For example:
2535 #define CONFIG_I2C_ENV_EEPROM_BUS "pca9547:70:d\0"
2537 EEPROM which holds the environment, is reached over
2538 a pca9547 i2c mux with address 0x70, channel 3.
2540 - CONFIG_ENV_IS_IN_DATAFLASH:
2542 Define this if you have a DataFlash memory device which you
2543 want to use for the environment.
2545 - CONFIG_ENV_OFFSET:
2549 These three #defines specify the offset and size of the
2550 environment area within the total memory of your DataFlash placed
2551 at the specified address.
2553 - CONFIG_ENV_IS_IN_NAND:
2555 Define this if you have a NAND device which you want to use
2556 for the environment.
2558 - CONFIG_ENV_OFFSET:
2561 These two #defines specify the offset and size of the environment
2562 area within the first NAND device. CONFIG_ENV_OFFSET must be
2563 aligned to an erase block boundary.
2565 - CONFIG_ENV_OFFSET_REDUND (optional):
2567 This setting describes a second storage area of CONFIG_ENV_SIZE
2568 size used to hold a redundant copy of the environment data, so
2569 that there is a valid backup copy in case there is a power failure
2570 during a "saveenv" operation. CONFIG_ENV_OFFSET_RENDUND must be
2571 aligned to an erase block boundary.
2573 - CONFIG_ENV_RANGE (optional):
2575 Specifies the length of the region in which the environment
2576 can be written. This should be a multiple of the NAND device's
2577 block size. Specifying a range with more erase blocks than
2578 are needed to hold CONFIG_ENV_SIZE allows bad blocks within
2579 the range to be avoided.
2581 - CONFIG_ENV_OFFSET_OOB (optional):
2583 Enables support for dynamically retrieving the offset of the
2584 environment from block zero's out-of-band data. The
2585 "nand env.oob" command can be used to record this offset.
2586 Currently, CONFIG_ENV_OFFSET_REDUND is not supported when
2587 using CONFIG_ENV_OFFSET_OOB.
2589 - CONFIG_NAND_ENV_DST
2591 Defines address in RAM to which the nand_spl code should copy the
2592 environment. If redundant environment is used, it will be copied to
2593 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE.
2595 - CONFIG_SYS_SPI_INIT_OFFSET
2597 Defines offset to the initial SPI buffer area in DPRAM. The
2598 area is used at an early stage (ROM part) if the environment
2599 is configured to reside in the SPI EEPROM: We need a 520 byte
2600 scratch DPRAM area. It is used between the two initialization
2601 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems
2602 to be a good choice since it makes it far enough from the
2603 start of the data area as well as from the stack pointer.
2605 Please note that the environment is read-only until the monitor
2606 has been relocated to RAM and a RAM copy of the environment has been
2607 created; also, when using EEPROM you will have to use getenv_f()
2608 until then to read environment variables.
2610 The environment is protected by a CRC32 checksum. Before the monitor
2611 is relocated into RAM, as a result of a bad CRC you will be working
2612 with the compiled-in default environment - *silently*!!! [This is
2613 necessary, because the first environment variable we need is the
2614 "baudrate" setting for the console - if we have a bad CRC, we don't
2615 have any device yet where we could complain.]
2617 Note: once the monitor has been relocated, then it will complain if
2618 the default environment is used; a new CRC is computed as soon as you
2619 use the "saveenv" command to store a valid environment.
2621 - CONFIG_SYS_FAULT_ECHO_LINK_DOWN:
2622 Echo the inverted Ethernet link state to the fault LED.
2624 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR
2625 also needs to be defined.
2627 - CONFIG_SYS_FAULT_MII_ADDR:
2628 MII address of the PHY to check for the Ethernet link state.
2630 - CONFIG_NS16550_MIN_FUNCTIONS:
2631 Define this if you desire to only have use of the NS16550_init
2632 and NS16550_putc functions for the serial driver located at
2633 drivers/serial/ns16550.c. This option is useful for saving
2634 space for already greatly restricted images, including but not
2635 limited to NAND_SPL configurations.
2637 Low Level (hardware related) configuration options:
2638 ---------------------------------------------------
2640 - CONFIG_SYS_CACHELINE_SIZE:
2641 Cache Line Size of the CPU.
2643 - CONFIG_SYS_DEFAULT_IMMR:
2644 Default address of the IMMR after system reset.
2646 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU,
2647 and RPXsuper) to be able to adjust the position of
2648 the IMMR register after a reset.
2650 - Floppy Disk Support:
2651 CONFIG_SYS_FDC_DRIVE_NUMBER
2653 the default drive number (default value 0)
2655 CONFIG_SYS_ISA_IO_STRIDE
2657 defines the spacing between FDC chipset registers
2660 CONFIG_SYS_ISA_IO_OFFSET
2662 defines the offset of register from address. It
2663 depends on which part of the data bus is connected to
2664 the FDC chipset. (default value 0)
2666 If CONFIG_SYS_ISA_IO_STRIDE CONFIG_SYS_ISA_IO_OFFSET and
2667 CONFIG_SYS_FDC_DRIVE_NUMBER are undefined, they take their
2670 if CONFIG_SYS_FDC_HW_INIT is defined, then the function
2671 fdc_hw_init() is called at the beginning of the FDC
2672 setup. fdc_hw_init() must be provided by the board
2673 source code. It is used to make hardware dependant
2676 - CONFIG_SYS_IMMR: Physical address of the Internal Memory.
2677 DO NOT CHANGE unless you know exactly what you're
2678 doing! (11-4) [MPC8xx/82xx systems only]
2680 - CONFIG_SYS_INIT_RAM_ADDR:
2682 Start address of memory area that can be used for
2683 initial data and stack; please note that this must be
2684 writable memory that is working WITHOUT special
2685 initialization, i. e. you CANNOT use normal RAM which
2686 will become available only after programming the
2687 memory controller and running certain initialization
2690 U-Boot uses the following memory types:
2691 - MPC8xx and MPC8260: IMMR (internal memory of the CPU)
2692 - MPC824X: data cache
2693 - PPC4xx: data cache
2695 - CONFIG_SYS_GBL_DATA_OFFSET:
2697 Offset of the initial data structure in the memory
2698 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually
2699 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial
2700 data is located at the end of the available space
2701 (sometimes written as (CONFIG_SYS_INIT_RAM_SIZE -
2702 CONFIG_SYS_INIT_DATA_SIZE), and the initial stack is just
2703 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR +
2704 CONFIG_SYS_GBL_DATA_OFFSET) downward.
2707 On the MPC824X (or other systems that use the data
2708 cache for initial memory) the address chosen for
2709 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must
2710 point to an otherwise UNUSED address space between
2711 the top of RAM and the start of the PCI space.
2713 - CONFIG_SYS_SIUMCR: SIU Module Configuration (11-6)
2715 - CONFIG_SYS_SYPCR: System Protection Control (11-9)
2717 - CONFIG_SYS_TBSCR: Time Base Status and Control (11-26)
2719 - CONFIG_SYS_PISCR: Periodic Interrupt Status and Control (11-31)
2721 - CONFIG_SYS_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30)
2723 - CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27)
2725 - CONFIG_SYS_OR_TIMING_SDRAM:
2728 - CONFIG_SYS_MAMR_PTA:
2729 periodic timer for refresh
2731 - CONFIG_SYS_DER: Debug Event Register (37-47)
2733 - FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM,
2734 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP,
2735 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM,
2736 CONFIG_SYS_BR1_PRELIM:
2737 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
2739 - SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
2740 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM,
2741 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM:
2742 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
2744 - CONFIG_SYS_MAMR_PTA, CONFIG_SYS_MPTPR_2BK_4K, CONFIG_SYS_MPTPR_1BK_4K, CONFIG_SYS_MPTPR_2BK_8K,
2745 CONFIG_SYS_MPTPR_1BK_8K, CONFIG_SYS_MAMR_8COL, CONFIG_SYS_MAMR_9COL:
2746 Machine Mode Register and Memory Periodic Timer
2747 Prescaler definitions (SDRAM timing)
2749 - CONFIG_SYS_I2C_UCODE_PATCH, CONFIG_SYS_I2C_DPMEM_OFFSET [0x1FC0]:
2750 enable I2C microcode relocation patch (MPC8xx);
2751 define relocation offset in DPRAM [DSP2]
2753 - CONFIG_SYS_SMC_UCODE_PATCH, CONFIG_SYS_SMC_DPMEM_OFFSET [0x1FC0]:
2754 enable SMC microcode relocation patch (MPC8xx);
2755 define relocation offset in DPRAM [SMC1]
2757 - CONFIG_SYS_SPI_UCODE_PATCH, CONFIG_SYS_SPI_DPMEM_OFFSET [0x1FC0]:
2758 enable SPI microcode relocation patch (MPC8xx);
2759 define relocation offset in DPRAM [SCC4]
2761 - CONFIG_SYS_USE_OSCCLK:
2762 Use OSCM clock mode on MBX8xx board. Be careful,
2763 wrong setting might damage your board. Read
2764 doc/README.MBX before setting this variable!
2766 - CONFIG_SYS_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only)
2767 Offset of the bootmode word in DPRAM used by post
2768 (Power On Self Tests). This definition overrides
2769 #define'd default value in commproc.h resp.
2772 - CONFIG_SYS_PCI_SLV_MEM_LOCAL, CONFIG_SYS_PCI_SLV_MEM_BUS, CONFIG_SYS_PICMR0_MASK_ATTRIB,
2773 CONFIG_SYS_PCI_MSTR0_LOCAL, CONFIG_SYS_PCIMSK0_MASK, CONFIG_SYS_PCI_MSTR1_LOCAL,
2774 CONFIG_SYS_PCIMSK1_MASK, CONFIG_SYS_PCI_MSTR_MEM_LOCAL, CONFIG_SYS_PCI_MSTR_MEM_BUS,
2775 CONFIG_SYS_CPU_PCI_MEM_START, CONFIG_SYS_PCI_MSTR_MEM_SIZE, CONFIG_SYS_POCMR0_MASK_ATTRIB,
2776 CONFIG_SYS_PCI_MSTR_MEMIO_LOCAL, CONFIG_SYS_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START,
2777 CONFIG_SYS_PCI_MSTR_MEMIO_SIZE, CONFIG_SYS_POCMR1_MASK_ATTRIB, CONFIG_SYS_PCI_MSTR_IO_LOCAL,
2778 CONFIG_SYS_PCI_MSTR_IO_BUS, CONFIG_SYS_CPU_PCI_IO_START, CONFIG_SYS_PCI_MSTR_IO_SIZE,
2779 CONFIG_SYS_POCMR2_MASK_ATTRIB: (MPC826x only)
2780 Overrides the default PCI memory map in arch/powerpc/cpu/mpc8260/pci.c if set.
2782 - CONFIG_PCI_DISABLE_PCIE:
2783 Disable PCI-Express on systems where it is supported but not
2787 Get DDR timing information from an I2C EEPROM. Common
2788 with pluggable memory modules such as SODIMMs
2791 I2C address of the SPD EEPROM
2793 - CONFIG_SYS_SPD_BUS_NUM
2794 If SPD EEPROM is on an I2C bus other than the first
2795 one, specify here. Note that the value must resolve
2796 to something your driver can deal with.
2798 - CONFIG_SYS_83XX_DDR_USES_CS0
2799 Only for 83xx systems. If specified, then DDR should
2800 be configured using CS0 and CS1 instead of CS2 and CS3.
2802 - CONFIG_ETHER_ON_FEC[12]
2803 Define to enable FEC[12] on a 8xx series processor.
2805 - CONFIG_FEC[12]_PHY
2806 Define to the hardcoded PHY address which corresponds
2807 to the given FEC; i. e.
2808 #define CONFIG_FEC1_PHY 4
2809 means that the PHY with address 4 is connected to FEC1
2811 When set to -1, means to probe for first available.
2813 - CONFIG_FEC[12]_PHY_NORXERR
2814 The PHY does not have a RXERR line (RMII only).
2815 (so program the FEC to ignore it).
2818 Enable RMII mode for all FECs.
2819 Note that this is a global option, we can't
2820 have one FEC in standard MII mode and another in RMII mode.
2822 - CONFIG_CRC32_VERIFY
2823 Add a verify option to the crc32 command.
2826 => crc32 -v <address> <count> <crc32>
2828 Where address/count indicate a memory area
2829 and crc32 is the correct crc32 which the
2833 Add the "loopw" memory command. This only takes effect if
2834 the memory commands are activated globally (CONFIG_CMD_MEM).
2837 Add the "mdc" and "mwc" memory commands. These are cyclic
2842 This command will print 4 bytes (10,11,12,13) each 500 ms.
2844 => mwc.l 100 12345678 10
2845 This command will write 12345678 to address 100 all 10 ms.
2847 This only takes effect if the memory commands are activated
2848 globally (CONFIG_CMD_MEM).
2850 - CONFIG_SKIP_LOWLEVEL_INIT
2851 [ARM only] If this variable is defined, then certain
2852 low level initializations (like setting up the memory
2853 controller) are omitted and/or U-Boot does not
2854 relocate itself into RAM.
2856 Normally this variable MUST NOT be defined. The only
2857 exception is when U-Boot is loaded (to RAM) by some
2858 other boot loader or by a debugger which performs
2859 these initializations itself.
2862 Modifies the behaviour of start.S when compiling a loader
2863 that is executed before the actual U-Boot. E.g. when
2864 compiling a NAND SPL.
2866 Building the Software:
2867 ======================
2869 Building U-Boot has been tested in several native build environments
2870 and in many different cross environments. Of course we cannot support
2871 all possibly existing versions of cross development tools in all
2872 (potentially obsolete) versions. In case of tool chain problems we
2873 recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK)
2874 which is extensively used to build and test U-Boot.
2876 If you are not using a native environment, it is assumed that you
2877 have GNU cross compiling tools available in your path. In this case,
2878 you must set the environment variable CROSS_COMPILE in your shell.
2879 Note that no changes to the Makefile or any other source files are
2880 necessary. For example using the ELDK on a 4xx CPU, please enter:
2882 $ CROSS_COMPILE=ppc_4xx-
2883 $ export CROSS_COMPILE
2885 Note: If you wish to generate Windows versions of the utilities in
2886 the tools directory you can use the MinGW toolchain
2887 (http://www.mingw.org). Set your HOST tools to the MinGW
2888 toolchain and execute 'make tools'. For example:
2890 $ make HOSTCC=i586-mingw32msvc-gcc HOSTSTRIP=i586-mingw32msvc-strip tools
2892 Binaries such as tools/mkimage.exe will be created which can
2893 be executed on computers running Windows.
2895 U-Boot is intended to be simple to build. After installing the
2896 sources you must configure U-Boot for one specific board type. This
2901 where "NAME_config" is the name of one of the existing configu-
2902 rations; see the main Makefile for supported names.
2904 Note: for some board special configuration names may exist; check if
2905 additional information is available from the board vendor; for
2906 instance, the TQM823L systems are available without (standard)
2907 or with LCD support. You can select such additional "features"
2908 when choosing the configuration, i. e.
2911 - will configure for a plain TQM823L, i. e. no LCD support
2913 make TQM823L_LCD_config
2914 - will configure for a TQM823L with U-Boot console on LCD
2919 Finally, type "make all", and you should get some working U-Boot
2920 images ready for download to / installation on your system:
2922 - "u-boot.bin" is a raw binary image
2923 - "u-boot" is an image in ELF binary format
2924 - "u-boot.srec" is in Motorola S-Record format
2926 By default the build is performed locally and the objects are saved
2927 in the source directory. One of the two methods can be used to change
2928 this behavior and build U-Boot to some external directory:
2930 1. Add O= to the make command line invocations:
2932 make O=/tmp/build distclean
2933 make O=/tmp/build NAME_config
2934 make O=/tmp/build all
2936 2. Set environment variable BUILD_DIR to point to the desired location:
2938 export BUILD_DIR=/tmp/build
2943 Note that the command line "O=" setting overrides the BUILD_DIR environment
2947 Please be aware that the Makefiles assume you are using GNU make, so
2948 for instance on NetBSD you might need to use "gmake" instead of
2952 If the system board that you have is not listed, then you will need
2953 to port U-Boot to your hardware platform. To do this, follow these
2956 1. Add a new configuration option for your board to the toplevel
2957 "Makefile" and to the "MAKEALL" script, using the existing
2958 entries as examples. Note that here and at many other places
2959 boards and other names are listed in alphabetical sort order. Please
2961 2. Create a new directory to hold your board specific code. Add any
2962 files you need. In your board directory, you will need at least
2963 the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds".
2964 3. Create a new configuration file "include/configs/<board>.h" for
2966 3. If you're porting U-Boot to a new CPU, then also create a new
2967 directory to hold your CPU specific code. Add any files you need.
2968 4. Run "make <board>_config" with your new name.
2969 5. Type "make", and you should get a working "u-boot.srec" file
2970 to be installed on your target system.
2971 6. Debug and solve any problems that might arise.
2972 [Of course, this last step is much harder than it sounds.]
2975 Testing of U-Boot Modifications, Ports to New Hardware, etc.:
2976 ==============================================================
2978 If you have modified U-Boot sources (for instance added a new board
2979 or support for new devices, a new CPU, etc.) you are expected to
2980 provide feedback to the other developers. The feedback normally takes
2981 the form of a "patch", i. e. a context diff against a certain (latest
2982 official or latest in the git repository) version of U-Boot sources.
2984 But before you submit such a patch, please verify that your modifi-
2985 cation did not break existing code. At least make sure that *ALL* of
2986 the supported boards compile WITHOUT ANY compiler warnings. To do so,
2987 just run the "MAKEALL" script, which will configure and build U-Boot
2988 for ALL supported system. Be warned, this will take a while. You can
2989 select which (cross) compiler to use by passing a `CROSS_COMPILE'
2990 environment variable to the script, i. e. to use the ELDK cross tools
2993 CROSS_COMPILE=ppc_8xx- MAKEALL
2995 or to build on a native PowerPC system you can type
2997 CROSS_COMPILE=' ' MAKEALL
2999 When using the MAKEALL script, the default behaviour is to build
3000 U-Boot in the source directory. This location can be changed by
3001 setting the BUILD_DIR environment variable. Also, for each target
3002 built, the MAKEALL script saves two log files (<target>.ERR and
3003 <target>.MAKEALL) in the <source dir>/LOG directory. This default
3004 location can be changed by setting the MAKEALL_LOGDIR environment
3005 variable. For example:
3007 export BUILD_DIR=/tmp/build
3008 export MAKEALL_LOGDIR=/tmp/log
3009 CROSS_COMPILE=ppc_8xx- MAKEALL
3011 With the above settings build objects are saved in the /tmp/build,
3012 log files are saved in the /tmp/log and the source tree remains clean
3013 during the whole build process.
3016 See also "U-Boot Porting Guide" below.
3019 Monitor Commands - Overview:
3020 ============================
3022 go - start application at address 'addr'
3023 run - run commands in an environment variable
3024 bootm - boot application image from memory
3025 bootp - boot image via network using BootP/TFTP protocol
3026 tftpboot- boot image via network using TFTP protocol
3027 and env variables "ipaddr" and "serverip"
3028 (and eventually "gatewayip")
3029 rarpboot- boot image via network using RARP/TFTP protocol
3030 diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
3031 loads - load S-Record file over serial line
3032 loadb - load binary file over serial line (kermit mode)
3034 mm - memory modify (auto-incrementing)
3035 nm - memory modify (constant address)
3036 mw - memory write (fill)
3038 cmp - memory compare
3039 crc32 - checksum calculation
3040 i2c - I2C sub-system
3041 sspi - SPI utility commands
3042 base - print or set address offset
3043 printenv- print environment variables
3044 setenv - set environment variables
3045 saveenv - save environment variables to persistent storage
3046 protect - enable or disable FLASH write protection
3047 erase - erase FLASH memory
3048 flinfo - print FLASH memory information
3049 bdinfo - print Board Info structure
3050 iminfo - print header information for application image
3051 coninfo - print console devices and informations
3052 ide - IDE sub-system
3053 loop - infinite loop on address range
3054 loopw - infinite write loop on address range
3055 mtest - simple RAM test
3056 icache - enable or disable instruction cache
3057 dcache - enable or disable data cache
3058 reset - Perform RESET of the CPU
3059 echo - echo args to console
3060 version - print monitor version
3061 help - print online help
3062 ? - alias for 'help'
3065 Monitor Commands - Detailed Description:
3066 ========================================
3070 For now: just type "help <command>".
3073 Environment Variables:
3074 ======================
3076 U-Boot supports user configuration using Environment Variables which
3077 can be made persistent by saving to Flash memory.
3079 Environment Variables are set using "setenv", printed using
3080 "printenv", and saved to Flash using "saveenv". Using "setenv"
3081 without a value can be used to delete a variable from the
3082 environment. As long as you don't save the environment you are
3083 working with an in-memory copy. In case the Flash area containing the
3084 environment is erased by accident, a default environment is provided.
3086 Some configuration options can be set using Environment Variables.
3088 List of environment variables (most likely not complete):
3090 baudrate - see CONFIG_BAUDRATE
3092 bootdelay - see CONFIG_BOOTDELAY
3094 bootcmd - see CONFIG_BOOTCOMMAND
3096 bootargs - Boot arguments when booting an RTOS image
3098 bootfile - Name of the image to load with TFTP
3100 bootm_low - 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 lowest address allowed
3103 for use by the bootm command. See also "bootm_size"
3104 environment variable. Address defined by "bootm_low" is
3105 also the base of the initial memory mapping for the Linux
3106 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ.
3108 bootm_size - Memory range available for image processing in the bootm
3109 command can be restricted. This variable is given as
3110 a hexadecimal number and defines the size of the region
3111 allowed for use by the bootm command. See also "bootm_low"
3112 environment variable.
3114 updatefile - Location of the software update file on a TFTP server, used
3115 by the automatic software update feature. Please refer to
3116 documentation in doc/README.update for more details.
3118 autoload - if set to "no" (any string beginning with 'n'),
3119 "bootp" will just load perform a lookup of the
3120 configuration from the BOOTP server, but not try to
3121 load any image using TFTP
3123 autostart - if set to "yes", an image loaded using the "bootp",
3124 "rarpboot", "tftpboot" or "diskboot" commands will
3125 be automatically started (by internally calling
3128 If set to "no", a standalone image passed to the
3129 "bootm" command will be copied to the load address
3130 (and eventually uncompressed), but NOT be started.
3131 This can be used to load and uncompress arbitrary
3134 i2cfast - (PPC405GP|PPC405EP only)
3135 if set to 'y' configures Linux I2C driver for fast
3136 mode (400kHZ). This environment variable is used in
3137 initialization code. So, for changes to be effective
3138 it must be saved and board must be reset.
3140 initrd_high - restrict positioning of initrd images:
3141 If this variable is not set, initrd images will be
3142 copied to the highest possible address in RAM; this
3143 is usually what you want since it allows for
3144 maximum initrd size. If for some reason you want to
3145 make sure that the initrd image is loaded below the
3146 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment
3147 variable to a value of "no" or "off" or "0".
3148 Alternatively, you can set it to a maximum upper
3149 address to use (U-Boot will still check that it
3150 does not overwrite the U-Boot stack and data).
3152 For instance, when you have a system with 16 MB
3153 RAM, and want to reserve 4 MB from use by Linux,
3154 you can do this by adding "mem=12M" to the value of
3155 the "bootargs" variable. However, now you must make
3156 sure that the initrd image is placed in the first
3157 12 MB as well - this can be done with
3159 setenv initrd_high 00c00000
3161 If you set initrd_high to 0xFFFFFFFF, this is an
3162 indication to U-Boot that all addresses are legal
3163 for the Linux kernel, including addresses in flash
3164 memory. In this case U-Boot will NOT COPY the
3165 ramdisk at all. This may be useful to reduce the
3166 boot time on your system, but requires that this
3167 feature is supported by your Linux kernel.
3169 ipaddr - IP address; needed for tftpboot command
3171 loadaddr - Default load address for commands like "bootp",
3172 "rarpboot", "tftpboot", "loadb" or "diskboot"
3174 loads_echo - see CONFIG_LOADS_ECHO
3176 serverip - TFTP server IP address; needed for tftpboot command
3178 bootretry - see CONFIG_BOOT_RETRY_TIME
3180 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
3182 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
3184 ethprime - When CONFIG_NET_MULTI is enabled controls which
3185 interface is used first.
3187 ethact - When CONFIG_NET_MULTI is enabled controls which
3188 interface is currently active. For example you
3189 can do the following
3191 => setenv ethact FEC
3192 => ping 192.168.0.1 # traffic sent on FEC
3193 => setenv ethact SCC
3194 => ping 10.0.0.1 # traffic sent on SCC
3196 ethrotate - When set to "no" U-Boot does not go through all
3197 available network interfaces.
3198 It just stays at the currently selected interface.
3200 netretry - When set to "no" each network operation will
3201 either succeed or fail without retrying.
3202 When set to "once" the network operation will
3203 fail when all the available network interfaces
3204 are tried once without success.
3205 Useful on scripts which control the retry operation
3208 npe_ucode - set load address for the NPE microcode
3210 tftpsrcport - If this is set, the value is used for TFTP's
3213 tftpdstport - If this is set, the value is used for TFTP's UDP
3214 destination port instead of the Well Know Port 69.
3216 tftpblocksize - Block size to use for TFTP transfers; if not set,
3217 we use the TFTP server's default block size
3219 tftptimeout - Retransmission timeout for TFTP packets (in milli-
3220 seconds, minimum value is 1000 = 1 second). Defines
3221 when a packet is considered to be lost so it has to
3222 be retransmitted. The default is 5000 = 5 seconds.
3223 Lowering this value may make downloads succeed
3224 faster in networks with high packet loss rates or
3225 with unreliable TFTP servers.
3227 vlan - When set to a value < 4095 the traffic over
3228 Ethernet is encapsulated/received over 802.1q
3231 The following environment variables may be used and automatically
3232 updated by the network boot commands ("bootp" and "rarpboot"),
3233 depending the information provided by your boot server:
3235 bootfile - see above
3236 dnsip - IP address of your Domain Name Server
3237 dnsip2 - IP address of your secondary Domain Name Server
3238 gatewayip - IP address of the Gateway (Router) to use
3239 hostname - Target hostname
3241 netmask - Subnet Mask
3242 rootpath - Pathname of the root filesystem on the NFS server
3243 serverip - see above
3246 There are two special Environment Variables:
3248 serial# - contains hardware identification information such
3249 as type string and/or serial number
3250 ethaddr - Ethernet address
3252 These variables can be set only once (usually during manufacturing of
3253 the board). U-Boot refuses to delete or overwrite these variables
3254 once they have been set once.
3257 Further special Environment Variables:
3259 ver - Contains the U-Boot version string as printed
3260 with the "version" command. This variable is
3261 readonly (see CONFIG_VERSION_VARIABLE).
3264 Please note that changes to some configuration parameters may take
3265 only effect after the next boot (yes, that's just like Windoze :-).
3268 Command Line Parsing:
3269 =====================
3271 There are two different command line parsers available with U-Boot:
3272 the old "simple" one, and the much more powerful "hush" shell:
3274 Old, simple command line parser:
3275 --------------------------------
3277 - supports environment variables (through setenv / saveenv commands)
3278 - several commands on one line, separated by ';'
3279 - variable substitution using "... ${name} ..." syntax
3280 - special characters ('$', ';') can be escaped by prefixing with '\',
3282 setenv bootcmd bootm \${address}
3283 - You can also escape text by enclosing in single apostrophes, for example:
3284 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
3289 - similar to Bourne shell, with control structures like
3290 if...then...else...fi, for...do...done; while...do...done,
3291 until...do...done, ...
3292 - supports environment ("global") variables (through setenv / saveenv
3293 commands) and local shell variables (through standard shell syntax
3294 "name=value"); only environment variables can be used with "run"
3300 (1) If a command line (or an environment variable executed by a "run"
3301 command) contains several commands separated by semicolon, and
3302 one of these commands fails, then the remaining commands will be
3305 (2) If you execute several variables with one call to run (i. e.
3306 calling run with a list of variables as arguments), any failing
3307 command will cause "run" to terminate, i. e. the remaining
3308 variables are not executed.
3310 Note for Redundant Ethernet Interfaces:
3311 =======================================
3313 Some boards come with redundant Ethernet interfaces; U-Boot supports
3314 such configurations and is capable of automatic selection of a
3315 "working" interface when needed. MAC assignment works as follows:
3317 Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
3318 MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
3319 "eth1addr" (=>eth1), "eth2addr", ...
3321 If the network interface stores some valid MAC address (for instance
3322 in SROM), this is used as default address if there is NO correspon-
3323 ding setting in the environment; if the corresponding environment
3324 variable is set, this overrides the settings in the card; that means:
3326 o If the SROM has a valid MAC address, and there is no address in the
3327 environment, the SROM's address is used.
3329 o If there is no valid address in the SROM, and a definition in the
3330 environment exists, then the value from the environment variable is
3333 o If both the SROM and the environment contain a MAC address, and
3334 both addresses are the same, this MAC address is used.
3336 o If both the SROM and the environment contain a MAC address, and the
3337 addresses differ, the value from the environment is used and a
3340 o If neither SROM nor the environment contain a MAC address, an error
3343 If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses
3344 will be programmed into hardware as part of the initialization process. This
3345 may be skipped by setting the appropriate 'ethmacskip' environment variable.
3346 The naming convention is as follows:
3347 "ethmacskip" (=>eth0), "eth1macskip" (=>eth1) etc.
3352 U-Boot is capable of booting (and performing other auxiliary operations on)
3353 images in two formats:
3355 New uImage format (FIT)
3356 -----------------------
3358 Flexible and powerful format based on Flattened Image Tree -- FIT (similar
3359 to Flattened Device Tree). It allows the use of images with multiple
3360 components (several kernels, ramdisks, etc.), with contents protected by
3361 SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory.
3367 Old image format is based on binary files which can be basically anything,
3368 preceded by a special header; see the definitions in include/image.h for
3369 details; basically, the header defines the following image properties:
3371 * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
3372 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
3373 LynxOS, pSOS, QNX, RTEMS, INTEGRITY;
3374 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS,
3376 * Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86,
3377 IA64, MIPS, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
3378 Currently supported: ARM, AVR32, Intel x86, MIPS, Nios II, PowerPC).
3379 * Compression Type (uncompressed, gzip, bzip2)
3385 The header is marked by a special Magic Number, and both the header
3386 and the data portions of the image are secured against corruption by
3393 Although U-Boot should support any OS or standalone application
3394 easily, the main focus has always been on Linux during the design of
3397 U-Boot includes many features that so far have been part of some
3398 special "boot loader" code within the Linux kernel. Also, any
3399 "initrd" images to be used are no longer part of one big Linux image;
3400 instead, kernel and "initrd" are separate images. This implementation
3401 serves several purposes:
3403 - the same features can be used for other OS or standalone
3404 applications (for instance: using compressed images to reduce the
3405 Flash memory footprint)
3407 - it becomes much easier to port new Linux kernel versions because
3408 lots of low-level, hardware dependent stuff are done by U-Boot
3410 - the same Linux kernel image can now be used with different "initrd"
3411 images; of course this also means that different kernel images can
3412 be run with the same "initrd". This makes testing easier (you don't
3413 have to build a new "zImage.initrd" Linux image when you just
3414 change a file in your "initrd"). Also, a field-upgrade of the
3415 software is easier now.
3421 Porting Linux to U-Boot based systems:
3422 ---------------------------------------
3424 U-Boot cannot save you from doing all the necessary modifications to
3425 configure the Linux device drivers for use with your target hardware
3426 (no, we don't intend to provide a full virtual machine interface to
3429 But now you can ignore ALL boot loader code (in arch/powerpc/mbxboot).
3431 Just make sure your machine specific header file (for instance
3432 include/asm-ppc/tqm8xx.h) includes the same definition of the Board
3433 Information structure as we define in include/asm-<arch>/u-boot.h,
3434 and make sure that your definition of IMAP_ADDR uses the same value
3435 as your U-Boot configuration in CONFIG_SYS_IMMR.
3438 Configuring the Linux kernel:
3439 -----------------------------
3441 No specific requirements for U-Boot. Make sure you have some root
3442 device (initial ramdisk, NFS) for your target system.
3445 Building a Linux Image:
3446 -----------------------
3448 With U-Boot, "normal" build targets like "zImage" or "bzImage" are
3449 not used. If you use recent kernel source, a new build target
3450 "uImage" will exist which automatically builds an image usable by
3451 U-Boot. Most older kernels also have support for a "pImage" target,
3452 which was introduced for our predecessor project PPCBoot and uses a
3453 100% compatible format.
3462 The "uImage" build target uses a special tool (in 'tools/mkimage') to
3463 encapsulate a compressed Linux kernel image with header information,
3464 CRC32 checksum etc. for use with U-Boot. This is what we are doing:
3466 * build a standard "vmlinux" kernel image (in ELF binary format):
3468 * convert the kernel into a raw binary image:
3470 ${CROSS_COMPILE}-objcopy -O binary \
3471 -R .note -R .comment \
3472 -S vmlinux linux.bin
3474 * compress the binary image:
3478 * package compressed binary image for U-Boot:
3480 mkimage -A ppc -O linux -T kernel -C gzip \
3481 -a 0 -e 0 -n "Linux Kernel Image" \
3482 -d linux.bin.gz uImage
3485 The "mkimage" tool can also be used to create ramdisk images for use
3486 with U-Boot, either separated from the Linux kernel image, or
3487 combined into one file. "mkimage" encapsulates the images with a 64
3488 byte header containing information about target architecture,
3489 operating system, image type, compression method, entry points, time
3490 stamp, CRC32 checksums, etc.
3492 "mkimage" can be called in two ways: to verify existing images and
3493 print the header information, or to build new images.
3495 In the first form (with "-l" option) mkimage lists the information
3496 contained in the header of an existing U-Boot image; this includes
3497 checksum verification:
3499 tools/mkimage -l image
3500 -l ==> list image header information
3502 The second form (with "-d" option) is used to build a U-Boot image
3503 from a "data file" which is used as image payload:
3505 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
3506 -n name -d data_file image
3507 -A ==> set architecture to 'arch'
3508 -O ==> set operating system to 'os'
3509 -T ==> set image type to 'type'
3510 -C ==> set compression type 'comp'
3511 -a ==> set load address to 'addr' (hex)
3512 -e ==> set entry point to 'ep' (hex)
3513 -n ==> set image name to 'name'
3514 -d ==> use image data from 'datafile'
3516 Right now, all Linux kernels for PowerPC systems use the same load
3517 address (0x00000000), but the entry point address depends on the
3520 - 2.2.x kernels have the entry point at 0x0000000C,
3521 - 2.3.x and later kernels have the entry point at 0x00000000.
3523 So a typical call to build a U-Boot image would read:
3525 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
3526 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
3527 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz \
3528 > examples/uImage.TQM850L
3529 Image Name: 2.4.4 kernel for TQM850L
3530 Created: Wed Jul 19 02:34:59 2000
3531 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3532 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
3533 Load Address: 0x00000000
3534 Entry Point: 0x00000000
3536 To verify the contents of the image (or check for corruption):
3538 -> tools/mkimage -l examples/uImage.TQM850L
3539 Image Name: 2.4.4 kernel for TQM850L
3540 Created: Wed Jul 19 02:34:59 2000
3541 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3542 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
3543 Load Address: 0x00000000
3544 Entry Point: 0x00000000
3546 NOTE: for embedded systems where boot time is critical you can trade
3547 speed for memory and install an UNCOMPRESSED image instead: this
3548 needs more space in Flash, but boots much faster since it does not
3549 need to be uncompressed:
3551 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz
3552 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
3553 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
3554 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux \
3555 > examples/uImage.TQM850L-uncompressed
3556 Image Name: 2.4.4 kernel for TQM850L
3557 Created: Wed Jul 19 02:34:59 2000
3558 Image Type: PowerPC Linux Kernel Image (uncompressed)
3559 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
3560 Load Address: 0x00000000
3561 Entry Point: 0x00000000
3564 Similar you can build U-Boot images from a 'ramdisk.image.gz' file
3565 when your kernel is intended to use an initial ramdisk:
3567 -> tools/mkimage -n 'Simple Ramdisk Image' \
3568 > -A ppc -O linux -T ramdisk -C gzip \
3569 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
3570 Image Name: Simple Ramdisk Image
3571 Created: Wed Jan 12 14:01:50 2000
3572 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
3573 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
3574 Load Address: 0x00000000
3575 Entry Point: 0x00000000
3578 Installing a Linux Image:
3579 -------------------------
3581 To downloading a U-Boot image over the serial (console) interface,
3582 you must convert the image to S-Record format:
3584 objcopy -I binary -O srec examples/image examples/image.srec
3586 The 'objcopy' does not understand the information in the U-Boot
3587 image header, so the resulting S-Record file will be relative to
3588 address 0x00000000. To load it to a given address, you need to
3589 specify the target address as 'offset' parameter with the 'loads'
3592 Example: install the image to address 0x40100000 (which on the
3593 TQM8xxL is in the first Flash bank):
3595 => erase 40100000 401FFFFF
3601 ## Ready for S-Record download ...
3602 ~>examples/image.srec
3603 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
3605 15989 15990 15991 15992
3606 [file transfer complete]
3608 ## Start Addr = 0x00000000
3611 You can check the success of the download using the 'iminfo' command;
3612 this includes a checksum verification so you can be sure no data
3613 corruption happened:
3617 ## Checking Image at 40100000 ...
3618 Image Name: 2.2.13 for initrd on TQM850L
3619 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3620 Data Size: 335725 Bytes = 327 kB = 0 MB
3621 Load Address: 00000000
3622 Entry Point: 0000000c
3623 Verifying Checksum ... OK
3629 The "bootm" command is used to boot an application that is stored in
3630 memory (RAM or Flash). In case of a Linux kernel image, the contents
3631 of the "bootargs" environment variable is passed to the kernel as
3632 parameters. You can check and modify this variable using the
3633 "printenv" and "setenv" commands:
3636 => printenv bootargs
3637 bootargs=root=/dev/ram
3639 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
3641 => printenv bootargs
3642 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
3645 ## Booting Linux kernel at 40020000 ...
3646 Image Name: 2.2.13 for NFS on TQM850L
3647 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3648 Data Size: 381681 Bytes = 372 kB = 0 MB
3649 Load Address: 00000000
3650 Entry Point: 0000000c
3651 Verifying Checksum ... OK
3652 Uncompressing Kernel Image ... OK
3653 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
3654 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
3655 time_init: decrementer frequency = 187500000/60
3656 Calibrating delay loop... 49.77 BogoMIPS
3657 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
3660 If you want to boot a Linux kernel with initial RAM disk, you pass
3661 the memory addresses of both the kernel and the initrd image (PPBCOOT
3662 format!) to the "bootm" command:
3664 => imi 40100000 40200000
3666 ## Checking Image at 40100000 ...
3667 Image Name: 2.2.13 for initrd on TQM850L
3668 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3669 Data Size: 335725 Bytes = 327 kB = 0 MB
3670 Load Address: 00000000
3671 Entry Point: 0000000c
3672 Verifying Checksum ... OK
3674 ## Checking Image at 40200000 ...
3675 Image Name: Simple Ramdisk Image
3676 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
3677 Data Size: 566530 Bytes = 553 kB = 0 MB
3678 Load Address: 00000000
3679 Entry Point: 00000000
3680 Verifying Checksum ... OK
3682 => bootm 40100000 40200000
3683 ## Booting Linux kernel at 40100000 ...
3684 Image Name: 2.2.13 for initrd on TQM850L
3685 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3686 Data Size: 335725 Bytes = 327 kB = 0 MB
3687 Load Address: 00000000
3688 Entry Point: 0000000c
3689 Verifying Checksum ... OK
3690 Uncompressing Kernel Image ... OK
3691 ## Loading RAMDisk Image at 40200000 ...
3692 Image Name: Simple Ramdisk Image
3693 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
3694 Data Size: 566530 Bytes = 553 kB = 0 MB
3695 Load Address: 00000000
3696 Entry Point: 00000000
3697 Verifying Checksum ... OK
3698 Loading Ramdisk ... OK
3699 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
3700 Boot arguments: root=/dev/ram
3701 time_init: decrementer frequency = 187500000/60
3702 Calibrating delay loop... 49.77 BogoMIPS
3704 RAMDISK: Compressed image found at block 0
3705 VFS: Mounted root (ext2 filesystem).
3709 Boot Linux and pass a flat device tree:
3712 First, U-Boot must be compiled with the appropriate defines. See the section
3713 titled "Linux Kernel Interface" above for a more in depth explanation. The
3714 following is an example of how to start a kernel and pass an updated
3720 oft=oftrees/mpc8540ads.dtb
3721 => tftp $oftaddr $oft
3722 Speed: 1000, full duplex
3724 TFTP from server 192.168.1.1; our IP address is 192.168.1.101
3725 Filename 'oftrees/mpc8540ads.dtb'.
3726 Load address: 0x300000
3729 Bytes transferred = 4106 (100a hex)
3730 => tftp $loadaddr $bootfile
3731 Speed: 1000, full duplex
3733 TFTP from server 192.168.1.1; our IP address is 192.168.1.2
3735 Load address: 0x200000
3736 Loading:############
3738 Bytes transferred = 1029407 (fb51f hex)
3743 => bootm $loadaddr - $oftaddr
3744 ## Booting image at 00200000 ...
3745 Image Name: Linux-2.6.17-dirty
3746 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3747 Data Size: 1029343 Bytes = 1005.2 kB
3748 Load Address: 00000000
3749 Entry Point: 00000000
3750 Verifying Checksum ... OK
3751 Uncompressing Kernel Image ... OK
3752 Booting using flat device tree at 0x300000
3753 Using MPC85xx ADS machine description
3754 Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb
3758 More About U-Boot Image Types:
3759 ------------------------------
3761 U-Boot supports the following image types:
3763 "Standalone Programs" are directly runnable in the environment
3764 provided by U-Boot; it is expected that (if they behave
3765 well) you can continue to work in U-Boot after return from
3766 the Standalone Program.
3767 "OS Kernel Images" are usually images of some Embedded OS which
3768 will take over control completely. Usually these programs
3769 will install their own set of exception handlers, device
3770 drivers, set up the MMU, etc. - this means, that you cannot
3771 expect to re-enter U-Boot except by resetting the CPU.
3772 "RAMDisk Images" are more or less just data blocks, and their
3773 parameters (address, size) are passed to an OS kernel that is
3775 "Multi-File Images" contain several images, typically an OS
3776 (Linux) kernel image and one or more data images like
3777 RAMDisks. This construct is useful for instance when you want
3778 to boot over the network using BOOTP etc., where the boot
3779 server provides just a single image file, but you want to get
3780 for instance an OS kernel and a RAMDisk image.
3782 "Multi-File Images" start with a list of image sizes, each
3783 image size (in bytes) specified by an "uint32_t" in network
3784 byte order. This list is terminated by an "(uint32_t)0".
3785 Immediately after the terminating 0 follow the images, one by
3786 one, all aligned on "uint32_t" boundaries (size rounded up to
3787 a multiple of 4 bytes).
3789 "Firmware Images" are binary images containing firmware (like
3790 U-Boot or FPGA images) which usually will be programmed to
3793 "Script files" are command sequences that will be executed by
3794 U-Boot's command interpreter; this feature is especially
3795 useful when you configure U-Boot to use a real shell (hush)
3796 as command interpreter.
3802 One of the features of U-Boot is that you can dynamically load and
3803 run "standalone" applications, which can use some resources of
3804 U-Boot like console I/O functions or interrupt services.
3806 Two simple examples are included with the sources:
3811 'examples/hello_world.c' contains a small "Hello World" Demo
3812 application; it is automatically compiled when you build U-Boot.
3813 It's configured to run at address 0x00040004, so you can play with it
3817 ## Ready for S-Record download ...
3818 ~>examples/hello_world.srec
3819 1 2 3 4 5 6 7 8 9 10 11 ...
3820 [file transfer complete]
3822 ## Start Addr = 0x00040004
3824 => go 40004 Hello World! This is a test.
3825 ## Starting application at 0x00040004 ...
3836 Hit any key to exit ...
3838 ## Application terminated, rc = 0x0
3840 Another example, which demonstrates how to register a CPM interrupt
3841 handler with the U-Boot code, can be found in 'examples/timer.c'.
3842 Here, a CPM timer is set up to generate an interrupt every second.
3843 The interrupt service routine is trivial, just printing a '.'
3844 character, but this is just a demo program. The application can be
3845 controlled by the following keys:
3847 ? - print current values og the CPM Timer registers
3848 b - enable interrupts and start timer
3849 e - stop timer and disable interrupts
3850 q - quit application
3853 ## Ready for S-Record download ...
3854 ~>examples/timer.srec
3855 1 2 3 4 5 6 7 8 9 10 11 ...
3856 [file transfer complete]
3858 ## Start Addr = 0x00040004
3861 ## Starting application at 0x00040004 ...
3864 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
3867 [q, b, e, ?] Set interval 1000000 us
3870 [q, b, e, ?] ........
3871 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
3874 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
3877 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
3880 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
3882 [q, b, e, ?] ...Stopping timer
3884 [q, b, e, ?] ## Application terminated, rc = 0x0
3890 Over time, many people have reported problems when trying to use the
3891 "minicom" terminal emulation program for serial download. I (wd)
3892 consider minicom to be broken, and recommend not to use it. Under
3893 Unix, I recommend to use C-Kermit for general purpose use (and
3894 especially for kermit binary protocol download ("loadb" command), and
3895 use "cu" for S-Record download ("loads" command).
3897 Nevertheless, if you absolutely want to use it try adding this
3898 configuration to your "File transfer protocols" section:
3900 Name Program Name U/D FullScr IO-Red. Multi
3901 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
3902 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
3908 Starting at version 0.9.2, U-Boot supports NetBSD both as host
3909 (build U-Boot) and target system (boots NetBSD/mpc8xx).
3911 Building requires a cross environment; it is known to work on
3912 NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
3913 need gmake since the Makefiles are not compatible with BSD make).
3914 Note that the cross-powerpc package does not install include files;
3915 attempting to build U-Boot will fail because <machine/ansi.h> is
3916 missing. This file has to be installed and patched manually:
3918 # cd /usr/pkg/cross/powerpc-netbsd/include
3920 # ln -s powerpc machine
3921 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
3922 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
3924 Native builds *don't* work due to incompatibilities between native
3925 and U-Boot include files.
3927 Booting assumes that (the first part of) the image booted is a
3928 stage-2 loader which in turn loads and then invokes the kernel
3929 proper. Loader sources will eventually appear in the NetBSD source
3930 tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
3931 meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz
3934 Implementation Internals:
3935 =========================
3937 The following is not intended to be a complete description of every
3938 implementation detail. However, it should help to understand the
3939 inner workings of U-Boot and make it easier to port it to custom
3943 Initial Stack, Global Data:
3944 ---------------------------
3946 The implementation of U-Boot is complicated by the fact that U-Boot
3947 starts running out of ROM (flash memory), usually without access to
3948 system RAM (because the memory controller is not initialized yet).
3949 This means that we don't have writable Data or BSS segments, and BSS
3950 is not initialized as zero. To be able to get a C environment working
3951 at all, we have to allocate at least a minimal stack. Implementation
3952 options for this are defined and restricted by the CPU used: Some CPU
3953 models provide on-chip memory (like the IMMR area on MPC8xx and
3954 MPC826x processors), on others (parts of) the data cache can be
3955 locked as (mis-) used as memory, etc.
3957 Chris Hallinan posted a good summary of these issues to the
3958 U-Boot mailing list:
3960 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
3961 From: "Chris Hallinan" <clh@net1plus.com>
3962 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
3965 Correct me if I'm wrong, folks, but the way I understand it
3966 is this: Using DCACHE as initial RAM for Stack, etc, does not
3967 require any physical RAM backing up the cache. The cleverness
3968 is that the cache is being used as a temporary supply of
3969 necessary storage before the SDRAM controller is setup. It's
3970 beyond the scope of this list to explain the details, but you
3971 can see how this works by studying the cache architecture and
3972 operation in the architecture and processor-specific manuals.
3974 OCM is On Chip Memory, which I believe the 405GP has 4K. It
3975 is another option for the system designer to use as an
3976 initial stack/RAM area prior to SDRAM being available. Either
3977 option should work for you. Using CS 4 should be fine if your
3978 board designers haven't used it for something that would
3979 cause you grief during the initial boot! It is frequently not
3982 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere
3983 with your processor/board/system design. The default value
3984 you will find in any recent u-boot distribution in
3985 walnut.h should work for you. I'd set it to a value larger
3986 than your SDRAM module. If you have a 64MB SDRAM module, set
3987 it above 400_0000. Just make sure your board has no resources
3988 that are supposed to respond to that address! That code in
3989 start.S has been around a while and should work as is when
3990 you get the config right.
3995 It is essential to remember this, since it has some impact on the C
3996 code for the initialization procedures:
3998 * Initialized global data (data segment) is read-only. Do not attempt
4001 * Do not use any uninitialized global data (or implicitely initialized
4002 as zero data - BSS segment) at all - this is undefined, initiali-
4003 zation is performed later (when relocating to RAM).
4005 * Stack space is very limited. Avoid big data buffers or things like
4008 Having only the stack as writable memory limits means we cannot use
4009 normal global data to share information beween the code. But it
4010 turned out that the implementation of U-Boot can be greatly
4011 simplified by making a global data structure (gd_t) available to all
4012 functions. We could pass a pointer to this data as argument to _all_
4013 functions, but this would bloat the code. Instead we use a feature of
4014 the GCC compiler (Global Register Variables) to share the data: we
4015 place a pointer (gd) to the global data into a register which we
4016 reserve for this purpose.
4018 When choosing a register for such a purpose we are restricted by the
4019 relevant (E)ABI specifications for the current architecture, and by
4020 GCC's implementation.
4022 For PowerPC, the following registers have specific use:
4024 R2: reserved for system use
4025 R3-R4: parameter passing and return values
4026 R5-R10: parameter passing
4027 R13: small data area pointer
4031 (U-Boot also uses R12 as internal GOT pointer. r12
4032 is a volatile register so r12 needs to be reset when
4033 going back and forth between asm and C)
4035 ==> U-Boot will use R2 to hold a pointer to the global data
4037 Note: on PPC, we could use a static initializer (since the
4038 address of the global data structure is known at compile time),
4039 but it turned out that reserving a register results in somewhat
4040 smaller code - although the code savings are not that big (on
4041 average for all boards 752 bytes for the whole U-Boot image,
4042 624 text + 127 data).
4044 On Blackfin, the normal C ABI (except for P3) is followed as documented here:
4045 http://docs.blackfin.uclinux.org/doku.php?id=application_binary_interface
4047 ==> U-Boot will use P3 to hold a pointer to the global data
4049 On ARM, the following registers are used:
4051 R0: function argument word/integer result
4052 R1-R3: function argument word
4054 R10: stack limit (used only if stack checking if enabled)
4055 R11: argument (frame) pointer
4056 R12: temporary workspace
4059 R15: program counter
4061 ==> U-Boot will use R8 to hold a pointer to the global data
4063 On Nios II, the ABI is documented here:
4064 http://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf
4066 ==> U-Boot will use gp to hold a pointer to the global data
4068 Note: on Nios II, we give "-G0" option to gcc and don't use gp
4069 to access small data sections, so gp is free.
4071 NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope,
4072 or current versions of GCC may "optimize" the code too much.
4077 U-Boot runs in system state and uses physical addresses, i.e. the
4078 MMU is not used either for address mapping nor for memory protection.
4080 The available memory is mapped to fixed addresses using the memory
4081 controller. In this process, a contiguous block is formed for each
4082 memory type (Flash, SDRAM, SRAM), even when it consists of several
4083 physical memory banks.
4085 U-Boot is installed in the first 128 kB of the first Flash bank (on
4086 TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
4087 booting and sizing and initializing DRAM, the code relocates itself
4088 to the upper end of DRAM. Immediately below the U-Boot code some
4089 memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN
4090 configuration setting]. Below that, a structure with global Board
4091 Info data is placed, followed by the stack (growing downward).
4093 Additionally, some exception handler code is copied to the low 8 kB
4094 of DRAM (0x00000000 ... 0x00001FFF).
4096 So a typical memory configuration with 16 MB of DRAM could look like
4099 0x0000 0000 Exception Vector code
4102 0x0000 2000 Free for Application Use
4108 0x00FB FF20 Monitor Stack (Growing downward)
4109 0x00FB FFAC Board Info Data and permanent copy of global data
4110 0x00FC 0000 Malloc Arena
4113 0x00FE 0000 RAM Copy of Monitor Code
4114 ... eventually: LCD or video framebuffer
4115 ... eventually: pRAM (Protected RAM - unchanged by reset)
4116 0x00FF FFFF [End of RAM]
4119 System Initialization:
4120 ----------------------
4122 In the reset configuration, U-Boot starts at the reset entry point
4123 (on most PowerPC systems at address 0x00000100). Because of the reset
4124 configuration for CS0# this is a mirror of the onboard Flash memory.
4125 To be able to re-map memory U-Boot then jumps to its link address.
4126 To be able to implement the initialization code in C, a (small!)
4127 initial stack is set up in the internal Dual Ported RAM (in case CPUs
4128 which provide such a feature like MPC8xx or MPC8260), or in a locked
4129 part of the data cache. After that, U-Boot initializes the CPU core,
4130 the caches and the SIU.
4132 Next, all (potentially) available memory banks are mapped using a
4133 preliminary mapping. For example, we put them on 512 MB boundaries
4134 (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
4135 on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
4136 programmed for SDRAM access. Using the temporary configuration, a
4137 simple memory test is run that determines the size of the SDRAM
4140 When there is more than one SDRAM bank, and the banks are of
4141 different size, the largest is mapped first. For equal size, the first
4142 bank (CS2#) is mapped first. The first mapping is always for address
4143 0x00000000, with any additional banks following immediately to create
4144 contiguous memory starting from 0.
4146 Then, the monitor installs itself at the upper end of the SDRAM area
4147 and allocates memory for use by malloc() and for the global Board
4148 Info data; also, the exception vector code is copied to the low RAM
4149 pages, and the final stack is set up.
4151 Only after this relocation will you have a "normal" C environment;
4152 until that you are restricted in several ways, mostly because you are
4153 running from ROM, and because the code will have to be relocated to a
4157 U-Boot Porting Guide:
4158 ----------------------
4160 [Based on messages by Jerry Van Baren in the U-Boot-Users mailing
4164 int main(int argc, char *argv[])
4166 sighandler_t no_more_time;
4168 signal(SIGALRM, no_more_time);
4169 alarm(PROJECT_DEADLINE - toSec (3 * WEEK));
4171 if (available_money > available_manpower) {
4172 Pay consultant to port U-Boot;
4176 Download latest U-Boot source;
4178 Subscribe to u-boot mailing list;
4181 email("Hi, I am new to U-Boot, how do I get started?");
4184 Read the README file in the top level directory;
4185 Read http://www.denx.de/twiki/bin/view/DULG/Manual;
4186 Read applicable doc/*.README;
4187 Read the source, Luke;
4188 /* find . -name "*.[chS]" | xargs grep -i <keyword> */
4191 if (available_money > toLocalCurrency ($2500))
4194 Add a lot of aggravation and time;
4196 if (a similar board exists) { /* hopefully... */
4197 cp -a board/<similar> board/<myboard>
4198 cp include/configs/<similar>.h include/configs/<myboard>.h
4200 Create your own board support subdirectory;
4201 Create your own board include/configs/<myboard>.h file;
4203 Edit new board/<myboard> files
4204 Edit new include/configs/<myboard>.h
4209 Add / modify source code;
4213 email("Hi, I am having problems...");
4215 Send patch file to the U-Boot email list;
4216 if (reasonable critiques)
4217 Incorporate improvements from email list code review;
4219 Defend code as written;
4225 void no_more_time (int sig)
4234 All contributions to U-Boot should conform to the Linux kernel
4235 coding style; see the file "Documentation/CodingStyle" and the script
4236 "scripts/Lindent" in your Linux kernel source directory. In sources
4237 originating from U-Boot a style corresponding to "Lindent -pcs" (adding
4238 spaces before parameters to function calls) is actually used.
4240 Source files originating from a different project (for example the
4241 MTD subsystem) are generally exempt from these guidelines and are not
4242 reformated to ease subsequent migration to newer versions of those
4245 Please note that U-Boot is implemented in C (and to some small parts in
4246 Assembler); no C++ is used, so please do not use C++ style comments (//)
4249 Please also stick to the following formatting rules:
4250 - remove any trailing white space
4251 - use TAB characters for indentation, not spaces
4252 - make sure NOT to use DOS '\r\n' line feeds
4253 - do not add more than 2 empty lines to source files
4254 - do not add trailing empty lines to source files
4256 Submissions which do not conform to the standards may be returned
4257 with a request to reformat the changes.
4263 Since the number of patches for U-Boot is growing, we need to
4264 establish some rules. Submissions which do not conform to these rules
4265 may be rejected, even when they contain important and valuable stuff.
4267 Please see http://www.denx.de/wiki/U-Boot/Patches for details.
4269 Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>;
4270 see http://lists.denx.de/mailman/listinfo/u-boot
4272 When you send a patch, please include the following information with
4275 * For bug fixes: a description of the bug and how your patch fixes
4276 this bug. Please try to include a way of demonstrating that the
4277 patch actually fixes something.
4279 * For new features: a description of the feature and your
4282 * A CHANGELOG entry as plaintext (separate from the patch)
4284 * For major contributions, your entry to the CREDITS file
4286 * When you add support for a new board, don't forget to add this
4287 board to the MAKEALL script, too.
4289 * If your patch adds new configuration options, don't forget to
4290 document these in the README file.
4292 * The patch itself. If you are using git (which is *strongly*
4293 recommended) you can easily generate the patch using the
4294 "git-format-patch". If you then use "git-send-email" to send it to
4295 the U-Boot mailing list, you will avoid most of the common problems
4296 with some other mail clients.
4298 If you cannot use git, use "diff -purN OLD NEW". If your version of
4299 diff does not support these options, then get the latest version of
4302 The current directory when running this command shall be the parent
4303 directory of the U-Boot source tree (i. e. please make sure that
4304 your patch includes sufficient directory information for the
4307 We prefer patches as plain text. MIME attachments are discouraged,
4308 and compressed attachments must not be used.
4310 * If one logical set of modifications affects or creates several
4311 files, all these changes shall be submitted in a SINGLE patch file.
4313 * Changesets that contain different, unrelated modifications shall be
4314 submitted as SEPARATE patches, one patch per changeset.
4319 * Before sending the patch, run the MAKEALL script on your patched
4320 source tree and make sure that no errors or warnings are reported
4321 for any of the boards.
4323 * Keep your modifications to the necessary minimum: A patch
4324 containing several unrelated changes or arbitrary reformats will be
4325 returned with a request to re-formatting / split it.
4327 * If you modify existing code, make sure that your new code does not
4328 add to the memory footprint of the code ;-) Small is beautiful!
4329 When adding new features, these should compile conditionally only
4330 (using #ifdef), and the resulting code with the new feature
4331 disabled must not need more memory than the old code without your
4334 * Remember that there is a size limit of 100 kB per message on the
4335 u-boot mailing list. Bigger patches will be moderated. If they are
4336 reasonable and not too big, they will be acknowledged. But patches
4337 bigger than the size limit should be avoided.
projects / kernel / u-boot.git / blob