2 # (C) Copyright 2000 - 2009
3 # Wolfgang Denk, DENX Software Engineering, wd@denx.de.
5 # See file CREDITS for list of people who contributed to this
8 # This program is free software; you can redistribute it and/or
9 # modify it under the terms of the GNU General Public License as
10 # published by the Free Software Foundation; either version 2 of
11 # the License, or (at your option) any later version.
13 # This program is distributed in the hope that it will be useful,
14 # but WITHOUT ANY WARRANTY; without even the implied warranty of
15 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 # GNU General Public License for more details.
18 # You should have received a copy of the GNU General Public License
19 # along with this program; if not, write to the Free Software
20 # Foundation, Inc., 59 Temple Place, Suite 330, Boston,
27 This directory contains the source code for U-Boot, a boot loader for
28 Embedded boards based on PowerPC, ARM, MIPS and several other
29 processors, which can be installed in a boot ROM and used to
30 initialize and test the hardware or to download and run application
33 The development of U-Boot is closely related to Linux: some parts of
34 the source code originate in the Linux source tree, we have some
35 header files in common, and special provision has been made to
36 support booting of Linux images.
38 Some attention has been paid to make this software easily
39 configurable and extendable. For instance, all monitor commands are
40 implemented with the same call interface, so that it's very easy to
41 add new commands. Also, instead of permanently adding rarely used
42 code (for instance hardware test utilities) to the monitor, you can
43 load and run it dynamically.
49 In general, all boards for which a configuration option exists in the
50 Makefile have been tested to some extent and can be considered
51 "working". In fact, many of them are used in production systems.
53 In case of problems see the CHANGELOG and CREDITS files to find out
54 who contributed the specific port. The MAINTAINERS file lists board
61 In case you have questions about, problems with or contributions for
62 U-Boot you should send a message to the U-Boot mailing list at
63 <u-boot@lists.denx.de>. There is also an archive of previous traffic
64 on the mailing list - please search the archive before asking FAQ's.
65 Please see http://lists.denx.de/pipermail/u-boot and
66 http://dir.gmane.org/gmane.comp.boot-loaders.u-boot
69 Where to get source code:
70 =========================
72 The U-Boot source code is maintained in the git repository at
73 git://www.denx.de/git/u-boot.git ; you can browse it online at
74 http://www.denx.de/cgi-bin/gitweb.cgi?p=u-boot.git;a=summary
76 The "snapshot" links on this page allow you to download tarballs of
77 any version you might be interested in. Official releases are also
78 available for FTP download from the ftp://ftp.denx.de/pub/u-boot/
81 Pre-built (and tested) images are available from
82 ftp://ftp.denx.de/pub/u-boot/images/
88 - start from 8xxrom sources
89 - create PPCBoot project (http://sourceforge.net/projects/ppcboot)
91 - make it easier to add custom boards
92 - make it possible to add other [PowerPC] CPUs
93 - extend functions, especially:
94 * Provide extended interface to Linux boot loader
97 * PCMCIA / CompactFlash / ATA disk / SCSI ... boot
98 - create ARMBoot project (http://sourceforge.net/projects/armboot)
99 - add other CPU families (starting with ARM)
100 - create U-Boot project (http://sourceforge.net/projects/u-boot)
101 - current project page: see http://www.denx.de/wiki/U-Boot
107 The "official" name of this project is "Das U-Boot". The spelling
108 "U-Boot" shall be used in all written text (documentation, comments
109 in source files etc.). Example:
111 This is the README file for the U-Boot project.
113 File names etc. shall be based on the string "u-boot". Examples:
115 include/asm-ppc/u-boot.h
117 #include <asm/u-boot.h>
119 Variable names, preprocessor constants etc. shall be either based on
120 the string "u_boot" or on "U_BOOT". Example:
122 U_BOOT_VERSION u_boot_logo
123 IH_OS_U_BOOT u_boot_hush_start
129 Starting with the release in October 2008, the names of the releases
130 were changed from numerical release numbers without deeper meaning
131 into a time stamp based numbering. Regular releases are identified by
132 names consisting of the calendar year and month of the release date.
133 Additional fields (if present) indicate release candidates or bug fix
134 releases in "stable" maintenance trees.
137 U-Boot v2009.11 - Release November 2009
138 U-Boot v2009.11.1 - Release 1 in version November 2009 stable tree
139 U-Boot v2010.09-rc1 - Release candiate 1 for September 2010 release
145 /arch Architecture specific files
146 /arm Files generic to ARM architecture
147 /cpu CPU specific files
148 /arm720t Files specific to ARM 720 CPUs
149 /arm920t Files specific to ARM 920 CPUs
150 /at91rm9200 Files specific to Atmel AT91RM9200 CPU
151 /imx Files specific to Freescale MC9328 i.MX CPUs
152 /s3c24x0 Files specific to Samsung S3C24X0 CPUs
153 /arm925t Files specific to ARM 925 CPUs
154 /arm926ejs Files specific to ARM 926 CPUs
155 /arm1136 Files specific to ARM 1136 CPUs
156 /ixp Files specific to Intel XScale IXP CPUs
157 /pxa Files specific to Intel XScale PXA CPUs
158 /s3c44b0 Files specific to Samsung S3C44B0 CPUs
159 /sa1100 Files specific to Intel StrongARM SA1100 CPUs
160 /lib Architecture specific library files
161 /avr32 Files generic to AVR32 architecture
162 /cpu CPU specific files
163 /lib Architecture specific library files
164 /blackfin Files generic to Analog Devices Blackfin architecture
165 /cpu CPU specific files
166 /lib Architecture specific library files
167 /i386 Files generic to i386 architecture
168 /cpu CPU specific files
169 /lib Architecture specific library files
170 /m68k Files generic to m68k architecture
171 /cpu CPU specific files
172 /mcf52x2 Files specific to Freescale ColdFire MCF52x2 CPUs
173 /mcf5227x Files specific to Freescale ColdFire MCF5227x CPUs
174 /mcf532x Files specific to Freescale ColdFire MCF5329 CPUs
175 /mcf5445x Files specific to Freescale ColdFire MCF5445x CPUs
176 /mcf547x_8x Files specific to Freescale ColdFire MCF547x_8x CPUs
177 /lib Architecture specific library files
178 /microblaze Files generic to microblaze architecture
179 /cpu CPU specific files
180 /lib Architecture specific library files
181 /mips Files generic to MIPS architecture
182 /cpu CPU specific files
183 /lib Architecture specific library files
184 /nios2 Files generic to Altera NIOS2 architecture
185 /cpu CPU specific files
186 /lib Architecture specific library files
187 /powerpc Files generic to PowerPC architecture
188 /cpu CPU specific files
189 /74xx_7xx Files specific to Freescale MPC74xx and 7xx CPUs
190 /mpc5xx Files specific to Freescale MPC5xx CPUs
191 /mpc5xxx Files specific to Freescale MPC5xxx CPUs
192 /mpc8xx Files specific to Freescale MPC8xx CPUs
193 /mpc8220 Files specific to Freescale MPC8220 CPUs
194 /mpc824x Files specific to Freescale MPC824x CPUs
195 /mpc8260 Files specific to Freescale MPC8260 CPUs
196 /mpc85xx Files specific to Freescale MPC85xx CPUs
197 /ppc4xx Files specific to AMCC PowerPC 4xx CPUs
198 /lib Architecture specific library files
199 /sh Files generic to SH architecture
200 /cpu CPU specific files
201 /sh2 Files specific to sh2 CPUs
202 /sh3 Files specific to sh3 CPUs
203 /sh4 Files specific to sh4 CPUs
204 /lib Architecture specific library files
205 /sparc Files generic to SPARC architecture
206 /cpu CPU specific files
207 /leon2 Files specific to Gaisler LEON2 SPARC CPU
208 /leon3 Files specific to Gaisler LEON3 SPARC CPU
209 /lib Architecture specific library files
210 /api Machine/arch independent API for external apps
211 /board Board dependent files
212 /common Misc architecture independent functions
213 /disk Code for disk drive partition handling
214 /doc Documentation (don't expect too much)
215 /drivers Commonly used device drivers
216 /examples Example code for standalone applications, etc.
217 /fs Filesystem code (cramfs, ext2, jffs2, etc.)
218 /include Header Files
219 /lib Files generic to all architectures
220 /libfdt Library files to support flattened device trees
221 /lzma Library files to support LZMA decompression
222 /lzo Library files to support LZO decompression
224 /post Power On Self Test
225 /rtc Real Time Clock drivers
226 /tools Tools to build S-Record or U-Boot images, etc.
228 Software Configuration:
229 =======================
231 Configuration is usually done using C preprocessor defines; the
232 rationale behind that is to avoid dead code whenever possible.
234 There are two classes of configuration variables:
236 * Configuration _OPTIONS_:
237 These are selectable by the user and have names beginning with
240 * Configuration _SETTINGS_:
241 These depend on the hardware etc. and should not be meddled with if
242 you don't know what you're doing; they have names beginning with
245 Later we will add a configuration tool - probably similar to or even
246 identical to what's used for the Linux kernel. Right now, we have to
247 do the configuration by hand, which means creating some symbolic
248 links and editing some configuration files. We use the TQM8xxL boards
252 Selection of Processor Architecture and Board Type:
253 ---------------------------------------------------
255 For all supported boards there are ready-to-use default
256 configurations available; just type "make <board_name>_config".
258 Example: For a TQM823L module type:
263 For the Cogent platform, you need to specify the CPU type as well;
264 e.g. "make cogent_mpc8xx_config". And also configure the cogent
265 directory according to the instructions in cogent/README.
268 Configuration Options:
269 ----------------------
271 Configuration depends on the combination of board and CPU type; all
272 such information is kept in a configuration file
273 "include/configs/<board_name>.h".
275 Example: For a TQM823L module, all configuration settings are in
276 "include/configs/TQM823L.h".
279 Many of the options are named exactly as the corresponding Linux
280 kernel configuration options. The intention is to make it easier to
281 build a config tool - later.
284 The following options need to be configured:
286 - CPU Type: Define exactly one, e.g. CONFIG_MPC85XX.
288 - Board Type: Define exactly one, e.g. CONFIG_MPC8540ADS.
290 - CPU Daughterboard Type: (if CONFIG_ATSTK1000 is defined)
291 Define exactly one, e.g. CONFIG_ATSTK1002
293 - CPU Module Type: (if CONFIG_COGENT is defined)
294 Define exactly one of
296 --- FIXME --- not tested yet:
297 CONFIG_CMA286_60, CONFIG_CMA286_21, CONFIG_CMA286_60P,
298 CONFIG_CMA287_23, CONFIG_CMA287_50
300 - Motherboard Type: (if CONFIG_COGENT is defined)
301 Define exactly one of
302 CONFIG_CMA101, CONFIG_CMA102
304 - Motherboard I/O Modules: (if CONFIG_COGENT is defined)
305 Define one or more of
308 - Motherboard Options: (if CONFIG_CMA101 or CONFIG_CMA102 are defined)
309 Define one or more of
310 CONFIG_LCD_HEARTBEAT - update a character position on
311 the LCD display every second with
314 - Board flavour: (if CONFIG_MPC8260ADS is defined)
317 CONFIG_SYS_8260ADS - original MPC8260ADS
318 CONFIG_SYS_8266ADS - MPC8266ADS
319 CONFIG_SYS_PQ2FADS - PQ2FADS-ZU or PQ2FADS-VR
320 CONFIG_SYS_8272ADS - MPC8272ADS
322 - MPC824X Family Member (if CONFIG_MPC824X is defined)
323 Define exactly one of
324 CONFIG_MPC8240, CONFIG_MPC8245
326 - 8xx CPU Options: (if using an MPC8xx CPU)
327 CONFIG_8xx_GCLK_FREQ - deprecated: CPU clock if
328 get_gclk_freq() cannot work
329 e.g. if there is no 32KHz
330 reference PIT/RTC clock
331 CONFIG_8xx_OSCLK - PLL input clock (either EXTCLK
334 - 859/866/885 CPU options: (if using a MPC859 or MPC866 or MPC885 CPU):
335 CONFIG_SYS_8xx_CPUCLK_MIN
336 CONFIG_SYS_8xx_CPUCLK_MAX
337 CONFIG_8xx_CPUCLK_DEFAULT
338 See doc/README.MPC866
340 CONFIG_SYS_MEASURE_CPUCLK
342 Define this to measure the actual CPU clock instead
343 of relying on the correctness of the configured
344 values. Mostly useful for board bringup to make sure
345 the PLL is locked at the intended frequency. Note
346 that this requires a (stable) reference clock (32 kHz
347 RTC clock or CONFIG_SYS_8XX_XIN)
349 CONFIG_SYS_DELAYED_ICACHE
351 Define this option if you want to enable the
352 ICache only when Code runs from RAM.
354 - Intel Monahans options:
355 CONFIG_SYS_MONAHANS_RUN_MODE_OSC_RATIO
357 Defines the Monahans run mode to oscillator
358 ratio. Valid values are 8, 16, 24, 31. The core
359 frequency is this value multiplied by 13 MHz.
361 CONFIG_SYS_MONAHANS_TURBO_RUN_MODE_RATIO
363 Defines the Monahans turbo mode to oscillator
364 ratio. Valid values are 1 (default if undefined) and
365 2. The core frequency as calculated above is multiplied
368 - Linux Kernel Interface:
371 U-Boot stores all clock information in Hz
372 internally. For binary compatibility with older Linux
373 kernels (which expect the clocks passed in the
374 bd_info data to be in MHz) the environment variable
375 "clocks_in_mhz" can be defined so that U-Boot
376 converts clock data to MHZ before passing it to the
378 When CONFIG_CLOCKS_IN_MHZ is defined, a definition of
379 "clocks_in_mhz=1" is automatically included in the
382 CONFIG_MEMSIZE_IN_BYTES [relevant for MIPS only]
384 When transferring memsize parameter to linux, some versions
385 expect it to be in bytes, others in MB.
386 Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes.
390 New kernel versions are expecting firmware settings to be
391 passed using flattened device trees (based on open firmware
395 * New libfdt-based support
396 * Adds the "fdt" command
397 * The bootm command automatically updates the fdt
399 OF_CPU - The proper name of the cpus node (only required for
400 MPC512X and MPC5xxx based boards).
401 OF_SOC - The proper name of the soc node (only required for
402 MPC512X and MPC5xxx based boards).
403 OF_TBCLK - The timebase frequency.
404 OF_STDOUT_PATH - The path to the console device
406 boards with QUICC Engines require OF_QE to set UCC MAC
409 CONFIG_OF_BOARD_SETUP
411 Board code has addition modification that it wants to make
412 to the flat device tree before handing it off to the kernel
416 This define fills in the correct boot CPU in the boot
417 param header, the default value is zero if undefined.
421 U-Boot can detect if an IDE device is present or not.
422 If not, and this new config option is activated, U-Boot
423 removes the ATA node from the DTS before booting Linux,
424 so the Linux IDE driver does not probe the device and
425 crash. This is needed for buggy hardware (uc101) where
426 no pull down resistor is connected to the signal IDE5V_DD7.
428 - vxWorks boot parameters:
430 bootvx constructs a valid bootline using the following
431 environments variables: bootfile, ipaddr, serverip, hostname.
432 It loads the vxWorks image pointed bootfile.
434 CONFIG_SYS_VXWORKS_BOOT_DEVICE - The vxworks device name
435 CONFIG_SYS_VXWORKS_MAC_PTR - Ethernet 6 byte MA -address
436 CONFIG_SYS_VXWORKS_SERVERNAME - Name of the server
437 CONFIG_SYS_VXWORKS_BOOT_ADDR - Address of boot parameters
439 CONFIG_SYS_VXWORKS_ADD_PARAMS
441 Add it at the end of the bootline. E.g "u=username pw=secret"
443 Note: If a "bootargs" environment is defined, it will overwride
444 the defaults discussed just above.
449 Define this if you want support for Amba PrimeCell PL010 UARTs.
453 Define this if you want support for Amba PrimeCell PL011 UARTs.
457 If you have Amba PrimeCell PL011 UARTs, set this variable to
458 the clock speed of the UARTs.
462 If you have Amba PrimeCell PL010 or PL011 UARTs on your board,
463 define this to a list of base addresses for each (supported)
464 port. See e.g. include/configs/versatile.h
468 Depending on board, define exactly one serial port
469 (like CONFIG_8xx_CONS_SMC1, CONFIG_8xx_CONS_SMC2,
470 CONFIG_8xx_CONS_SCC1, ...), or switch off the serial
471 console by defining CONFIG_8xx_CONS_NONE
473 Note: if CONFIG_8xx_CONS_NONE is defined, the serial
474 port routines must be defined elsewhere
475 (i.e. serial_init(), serial_getc(), ...)
478 Enables console device for a color framebuffer. Needs following
479 defines (cf. smiLynxEM, i8042, board/eltec/bab7xx)
480 VIDEO_FB_LITTLE_ENDIAN graphic memory organisation
482 VIDEO_HW_RECTFILL graphic chip supports
485 VIDEO_HW_BITBLT graphic chip supports
486 bit-blit (cf. smiLynxEM)
487 VIDEO_VISIBLE_COLS visible pixel columns
489 VIDEO_VISIBLE_ROWS visible pixel rows
490 VIDEO_PIXEL_SIZE bytes per pixel
491 VIDEO_DATA_FORMAT graphic data format
492 (0-5, cf. cfb_console.c)
493 VIDEO_FB_ADRS framebuffer address
494 VIDEO_KBD_INIT_FCT keyboard int fct
495 (i.e. i8042_kbd_init())
496 VIDEO_TSTC_FCT test char fct
498 VIDEO_GETC_FCT get char fct
500 CONFIG_CONSOLE_CURSOR cursor drawing on/off
501 (requires blink timer
503 CONFIG_SYS_CONSOLE_BLINK_COUNT blink interval (cf. i8042.c)
504 CONFIG_CONSOLE_TIME display time/date info in
506 (requires CONFIG_CMD_DATE)
507 CONFIG_VIDEO_LOGO display Linux logo in
509 CONFIG_VIDEO_BMP_LOGO use bmp_logo.h instead of
510 linux_logo.h for logo.
511 Requires CONFIG_VIDEO_LOGO
512 CONFIG_CONSOLE_EXTRA_INFO
513 additional board info beside
516 When CONFIG_CFB_CONSOLE is defined, video console is
517 default i/o. Serial console can be forced with
518 environment 'console=serial'.
520 When CONFIG_SILENT_CONSOLE is defined, all console
521 messages (by U-Boot and Linux!) can be silenced with
522 the "silent" environment variable. See
523 doc/README.silent for more information.
526 CONFIG_BAUDRATE - in bps
527 Select one of the baudrates listed in
528 CONFIG_SYS_BAUDRATE_TABLE, see below.
529 CONFIG_SYS_BRGCLK_PRESCALE, baudrate prescale
531 - Console Rx buffer length
532 With CONFIG_SYS_SMC_RXBUFLEN it is possible to define
533 the maximum receive buffer length for the SMC.
534 This option is actual only for 82xx and 8xx possible.
535 If using CONFIG_SYS_SMC_RXBUFLEN also CONFIG_SYS_MAXIDLE
536 must be defined, to setup the maximum idle timeout for
539 - Boot Delay: CONFIG_BOOTDELAY - in seconds
540 Delay before automatically booting the default image;
541 set to -1 to disable autoboot.
543 See doc/README.autoboot for these options that
544 work with CONFIG_BOOTDELAY. None are required.
545 CONFIG_BOOT_RETRY_TIME
546 CONFIG_BOOT_RETRY_MIN
547 CONFIG_AUTOBOOT_KEYED
548 CONFIG_AUTOBOOT_PROMPT
549 CONFIG_AUTOBOOT_DELAY_STR
550 CONFIG_AUTOBOOT_STOP_STR
551 CONFIG_AUTOBOOT_DELAY_STR2
552 CONFIG_AUTOBOOT_STOP_STR2
553 CONFIG_ZERO_BOOTDELAY_CHECK
554 CONFIG_RESET_TO_RETRY
558 Only needed when CONFIG_BOOTDELAY is enabled;
559 define a command string that is automatically executed
560 when no character is read on the console interface
561 within "Boot Delay" after reset.
564 This can be used to pass arguments to the bootm
565 command. The value of CONFIG_BOOTARGS goes into the
566 environment value "bootargs".
568 CONFIG_RAMBOOT and CONFIG_NFSBOOT
569 The value of these goes into the environment as
570 "ramboot" and "nfsboot" respectively, and can be used
571 as a convenience, when switching between booting from
577 When this option is #defined, the existence of the
578 environment variable "preboot" will be checked
579 immediately before starting the CONFIG_BOOTDELAY
580 countdown and/or running the auto-boot command resp.
581 entering interactive mode.
583 This feature is especially useful when "preboot" is
584 automatically generated or modified. For an example
585 see the LWMON board specific code: here "preboot" is
586 modified when the user holds down a certain
587 combination of keys on the (special) keyboard when
590 - Serial Download Echo Mode:
592 If defined to 1, all characters received during a
593 serial download (using the "loads" command) are
594 echoed back. This might be needed by some terminal
595 emulations (like "cu"), but may as well just take
596 time on others. This setting #define's the initial
597 value of the "loads_echo" environment variable.
599 - Kgdb Serial Baudrate: (if CONFIG_CMD_KGDB is defined)
601 Select one of the baudrates listed in
602 CONFIG_SYS_BAUDRATE_TABLE, see below.
605 Monitor commands can be included or excluded
606 from the build by using the #include files
607 "config_cmd_all.h" and #undef'ing unwanted
608 commands, or using "config_cmd_default.h"
609 and augmenting with additional #define's
612 The default command configuration includes all commands
613 except those marked below with a "*".
615 CONFIG_CMD_ASKENV * ask for env variable
616 CONFIG_CMD_BDI bdinfo
617 CONFIG_CMD_BEDBUG * Include BedBug Debugger
618 CONFIG_CMD_BMP * BMP support
619 CONFIG_CMD_BSP * Board specific commands
620 CONFIG_CMD_BOOTD bootd
621 CONFIG_CMD_CACHE * icache, dcache
622 CONFIG_CMD_CONSOLE coninfo
623 CONFIG_CMD_DATE * support for RTC, date/time...
624 CONFIG_CMD_DHCP * DHCP support
625 CONFIG_CMD_DIAG * Diagnostics
626 CONFIG_CMD_DS4510 * ds4510 I2C gpio commands
627 CONFIG_CMD_DS4510_INFO * ds4510 I2C info command
628 CONFIG_CMD_DS4510_MEM * ds4510 I2C eeprom/sram commansd
629 CONFIG_CMD_DS4510_RST * ds4510 I2C rst command
630 CONFIG_CMD_DTT * Digital Therm and Thermostat
631 CONFIG_CMD_ECHO echo arguments
632 CONFIG_CMD_EDITENV edit env variable
633 CONFIG_CMD_EEPROM * EEPROM read/write support
634 CONFIG_CMD_ELF * bootelf, bootvx
635 CONFIG_CMD_SAVEENV saveenv
636 CONFIG_CMD_FDC * Floppy Disk Support
637 CONFIG_CMD_FAT * FAT partition support
638 CONFIG_CMD_FDOS * Dos diskette Support
639 CONFIG_CMD_FLASH flinfo, erase, protect
640 CONFIG_CMD_FPGA FPGA device initialization support
641 CONFIG_CMD_HWFLOW * RTS/CTS hw flow control
642 CONFIG_CMD_I2C * I2C serial bus support
643 CONFIG_CMD_IDE * IDE harddisk support
644 CONFIG_CMD_IMI iminfo
645 CONFIG_CMD_IMLS List all found images
646 CONFIG_CMD_IMMAP * IMMR dump support
647 CONFIG_CMD_IRQ * irqinfo
648 CONFIG_CMD_ITEST Integer/string test of 2 values
649 CONFIG_CMD_JFFS2 * JFFS2 Support
650 CONFIG_CMD_KGDB * kgdb
651 CONFIG_CMD_LOADB loadb
652 CONFIG_CMD_LOADS loads
653 CONFIG_CMD_MD5SUM print md5 message digest
654 (requires CONFIG_CMD_MEMORY and CONFIG_MD5)
655 CONFIG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base,
657 CONFIG_CMD_MISC Misc functions like sleep etc
658 CONFIG_CMD_MMC * MMC memory mapped support
659 CONFIG_CMD_MII * MII utility commands
660 CONFIG_CMD_MTDPARTS * MTD partition support
661 CONFIG_CMD_NAND * NAND support
662 CONFIG_CMD_NET bootp, tftpboot, rarpboot
663 CONFIG_CMD_PCA953X * PCA953x I2C gpio commands
664 CONFIG_CMD_PCA953X_INFO * PCA953x I2C gpio info command
665 CONFIG_CMD_PCI * pciinfo
666 CONFIG_CMD_PCMCIA * PCMCIA support
667 CONFIG_CMD_PING * send ICMP ECHO_REQUEST to network
669 CONFIG_CMD_PORTIO * Port I/O
670 CONFIG_CMD_REGINFO * Register dump
671 CONFIG_CMD_RUN run command in env variable
672 CONFIG_CMD_SAVES * save S record dump
673 CONFIG_CMD_SCSI * SCSI Support
674 CONFIG_CMD_SDRAM * print SDRAM configuration information
675 (requires CONFIG_CMD_I2C)
676 CONFIG_CMD_SETGETDCR Support for DCR Register access
678 CONFIG_CMD_SHA1SUM print sha1 memory digest
679 (requires CONFIG_CMD_MEMORY)
680 CONFIG_CMD_SOURCE "source" command Support
681 CONFIG_CMD_SPI * SPI serial bus support
682 CONFIG_CMD_USB * USB support
683 CONFIG_CMD_VFD * VFD support (TRAB)
684 CONFIG_CMD_CDP * Cisco Discover Protocol support
685 CONFIG_CMD_FSL * Microblaze FSL support
688 EXAMPLE: If you want all functions except of network
689 support you can write:
691 #include "config_cmd_all.h"
692 #undef CONFIG_CMD_NET
695 fdt (flattened device tree) command: CONFIG_OF_LIBFDT
697 Note: Don't enable the "icache" and "dcache" commands
698 (configuration option CONFIG_CMD_CACHE) unless you know
699 what you (and your U-Boot users) are doing. Data
700 cache cannot be enabled on systems like the 8xx or
701 8260 (where accesses to the IMMR region must be
702 uncached), and it cannot be disabled on all other
703 systems where we (mis-) use the data cache to hold an
704 initial stack and some data.
707 XXX - this list needs to get updated!
711 If this variable is defined, it enables watchdog
712 support. There must be support in the platform specific
713 code for a watchdog. For the 8xx and 8260 CPUs, the
714 SIU Watchdog feature is enabled in the SYPCR
718 CONFIG_VERSION_VARIABLE
719 If this variable is defined, an environment variable
720 named "ver" is created by U-Boot showing the U-Boot
721 version as printed by the "version" command.
722 This variable is readonly.
726 When CONFIG_CMD_DATE is selected, the type of the RTC
727 has to be selected, too. Define exactly one of the
730 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx
731 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC
732 CONFIG_RTC_MC13783 - use MC13783 RTC
733 CONFIG_RTC_MC146818 - use MC146818 RTC
734 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC
735 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC
736 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC
737 CONFIG_RTC_DS164x - use Dallas DS164x RTC
738 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC
739 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC
740 CONFIG_SYS_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337
742 Note that if the RTC uses I2C, then the I2C interface
743 must also be configured. See I2C Support, below.
746 CONFIG_PCA953X - use NXP's PCA953X series I2C GPIO
747 CONFIG_PCA953X_INFO - enable pca953x info command
749 The CONFIG_SYS_I2C_PCA953X_WIDTH option specifies a list of
750 chip-ngpio pairs that tell the PCA953X driver the number of
751 pins supported by a particular chip.
753 Note that if the GPIO device uses I2C, then the I2C interface
754 must also be configured. See I2C Support, below.
758 When CONFIG_TIMESTAMP is selected, the timestamp
759 (date and time) of an image is printed by image
760 commands like bootm or iminfo. This option is
761 automatically enabled when you select CONFIG_CMD_DATE .
764 CONFIG_MAC_PARTITION and/or CONFIG_DOS_PARTITION
765 and/or CONFIG_ISO_PARTITION and/or CONFIG_EFI_PARTITION
767 If IDE or SCSI support is enabled (CONFIG_CMD_IDE or
768 CONFIG_CMD_SCSI) you must configure support for at
769 least one partition type as well.
772 CONFIG_IDE_RESET_ROUTINE - this is defined in several
773 board configurations files but used nowhere!
775 CONFIG_IDE_RESET - is this is defined, IDE Reset will
776 be performed by calling the function
777 ide_set_reset(int reset)
778 which has to be defined in a board specific file
783 Set this to enable ATAPI support.
788 Set this to enable support for disks larger than 137GB
789 Also look at CONFIG_SYS_64BIT_LBA.
790 Whithout these , LBA48 support uses 32bit variables and will 'only'
791 support disks up to 2.1TB.
793 CONFIG_SYS_64BIT_LBA:
794 When enabled, makes the IDE subsystem use 64bit sector addresses.
798 At the moment only there is only support for the
799 SYM53C8XX SCSI controller; define
800 CONFIG_SCSI_SYM53C8XX to enable it.
802 CONFIG_SYS_SCSI_MAX_LUN [8], CONFIG_SYS_SCSI_MAX_SCSI_ID [7] and
803 CONFIG_SYS_SCSI_MAX_DEVICE [CONFIG_SYS_SCSI_MAX_SCSI_ID *
804 CONFIG_SYS_SCSI_MAX_LUN] can be adjusted to define the
805 maximum numbers of LUNs, SCSI ID's and target
807 CONFIG_SYS_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz)
809 - NETWORK Support (PCI):
811 Support for Intel 8254x gigabit chips.
813 CONFIG_E1000_FALLBACK_MAC
814 default MAC for empty EEPROM after production.
817 Support for Intel 82557/82559/82559ER chips.
818 Optional CONFIG_EEPRO100_SROM_WRITE enables EEPROM
819 write routine for first time initialisation.
822 Support for Digital 2114x chips.
823 Optional CONFIG_TULIP_SELECT_MEDIA for board specific
824 modem chip initialisation (KS8761/QS6611).
827 Support for National dp83815 chips.
830 Support for National dp8382[01] gigabit chips.
832 - NETWORK Support (other):
834 CONFIG_DRIVER_AT91EMAC
835 Support for AT91RM9200 EMAC.
838 Define this to use reduced MII inteface
840 CONFIG_DRIVER_AT91EMAC_QUIET
841 If this defined, the driver is quiet.
842 The driver doen't show link status messages.
844 CONFIG_DRIVER_LAN91C96
845 Support for SMSC's LAN91C96 chips.
848 Define this to hold the physical address
849 of the LAN91C96's I/O space
851 CONFIG_LAN91C96_USE_32_BIT
852 Define this to enable 32 bit addressing
854 CONFIG_DRIVER_SMC91111
855 Support for SMSC's LAN91C111 chip
858 Define this to hold the physical address
859 of the device (I/O space)
861 CONFIG_SMC_USE_32_BIT
862 Define this if data bus is 32 bits
864 CONFIG_SMC_USE_IOFUNCS
865 Define this to use i/o functions instead of macros
866 (some hardware wont work with macros)
869 Support for Faraday's FTGMAC100 Gigabit SoC Ethernet
871 CONFIG_FTGMAC100_EGIGA
872 Define this to use GE link update with gigabit PHY.
873 Define this if FTGMAC100 is connected to gigabit PHY.
874 If your system has 10/100 PHY only, it might not occur
875 wrong behavior. Because PHY usually return timeout or
876 useless data when polling gigabit status and gigabit
877 control registers. This behavior won't affect the
878 correctnessof 10/100 link speed update.
881 Support for SMSC's LAN911x and LAN921x chips
884 Define this to hold the physical address
885 of the device (I/O space)
887 CONFIG_SMC911X_32_BIT
888 Define this if data bus is 32 bits
890 CONFIG_SMC911X_16_BIT
891 Define this if data bus is 16 bits. If your processor
892 automatically converts one 32 bit word to two 16 bit
893 words you may also try CONFIG_SMC911X_32_BIT.
896 At the moment only the UHCI host controller is
897 supported (PIP405, MIP405, MPC5200); define
898 CONFIG_USB_UHCI to enable it.
899 define CONFIG_USB_KEYBOARD to enable the USB Keyboard
900 and define CONFIG_USB_STORAGE to enable the USB
903 Supported are USB Keyboards and USB Floppy drives
905 MPC5200 USB requires additional defines:
907 for 528 MHz Clock: 0x0001bbbb
911 for differential drivers: 0x00001000
912 for single ended drivers: 0x00005000
913 for differential drivers on PSC3: 0x00000100
914 for single ended drivers on PSC3: 0x00004100
915 CONFIG_SYS_USB_EVENT_POLL
916 May be defined to allow interrupt polling
917 instead of using asynchronous interrupts
920 Define the below if you wish to use the USB console.
921 Once firmware is rebuilt from a serial console issue the
922 command "setenv stdin usbtty; setenv stdout usbtty" and
923 attach your USB cable. The Unix command "dmesg" should print
924 it has found a new device. The environment variable usbtty
925 can be set to gserial or cdc_acm to enable your device to
926 appear to a USB host as a Linux gserial device or a
927 Common Device Class Abstract Control Model serial device.
928 If you select usbtty = gserial you should be able to enumerate
930 # modprobe usbserial vendor=0xVendorID product=0xProductID
931 else if using cdc_acm, simply setting the environment
932 variable usbtty to be cdc_acm should suffice. The following
933 might be defined in YourBoardName.h
936 Define this to build a UDC device
939 Define this to have a tty type of device available to
940 talk to the UDC device
942 CONFIG_SYS_CONSOLE_IS_IN_ENV
943 Define this if you want stdin, stdout &/or stderr to
947 CONFIG_SYS_USB_EXTC_CLK 0xBLAH
948 Derive USB clock from external clock "blah"
949 - CONFIG_SYS_USB_EXTC_CLK 0x02
951 CONFIG_SYS_USB_BRG_CLK 0xBLAH
952 Derive USB clock from brgclk
953 - CONFIG_SYS_USB_BRG_CLK 0x04
955 If you have a USB-IF assigned VendorID then you may wish to
956 define your own vendor specific values either in BoardName.h
957 or directly in usbd_vendor_info.h. If you don't define
958 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME,
959 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot
960 should pretend to be a Linux device to it's target host.
962 CONFIG_USBD_MANUFACTURER
963 Define this string as the name of your company for
964 - CONFIG_USBD_MANUFACTURER "my company"
966 CONFIG_USBD_PRODUCT_NAME
967 Define this string as the name of your product
968 - CONFIG_USBD_PRODUCT_NAME "acme usb device"
971 Define this as your assigned Vendor ID from the USB
972 Implementors Forum. This *must* be a genuine Vendor ID
973 to avoid polluting the USB namespace.
974 - CONFIG_USBD_VENDORID 0xFFFF
976 CONFIG_USBD_PRODUCTID
977 Define this as the unique Product ID
979 - CONFIG_USBD_PRODUCTID 0xFFFF
983 The MMC controller on the Intel PXA is supported. To
984 enable this define CONFIG_MMC. The MMC can be
985 accessed from the boot prompt by mapping the device
986 to physical memory similar to flash. Command line is
987 enabled with CONFIG_CMD_MMC. The MMC driver also works with
988 the FAT fs. This is enabled with CONFIG_CMD_FAT.
990 - Journaling Flash filesystem support:
991 CONFIG_JFFS2_NAND, CONFIG_JFFS2_NAND_OFF, CONFIG_JFFS2_NAND_SIZE,
992 CONFIG_JFFS2_NAND_DEV
993 Define these for a default partition on a NAND device
995 CONFIG_SYS_JFFS2_FIRST_SECTOR,
996 CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS
997 Define these for a default partition on a NOR device
999 CONFIG_SYS_JFFS_CUSTOM_PART
1000 Define this to create an own partition. You have to provide a
1001 function struct part_info* jffs2_part_info(int part_num)
1003 If you define only one JFFS2 partition you may also want to
1004 #define CONFIG_SYS_JFFS_SINGLE_PART 1
1005 to disable the command chpart. This is the default when you
1006 have not defined a custom partition
1011 Define this to enable standard (PC-Style) keyboard
1015 Standard PC keyboard driver with US (is default) and
1016 GERMAN key layout (switch via environment 'keymap=de') support.
1017 Export function i8042_kbd_init, i8042_tstc and i8042_getc
1018 for cfb_console. Supports cursor blinking.
1023 Define this to enable video support (for output to
1026 CONFIG_VIDEO_CT69000
1028 Enable Chips & Technologies 69000 Video chip
1030 CONFIG_VIDEO_SMI_LYNXEM
1031 Enable Silicon Motion SMI 712/710/810 Video chip. The
1032 video output is selected via environment 'videoout'
1033 (1 = LCD and 2 = CRT). If videoout is undefined, CRT is
1036 For the CT69000 and SMI_LYNXEM drivers, videomode is
1037 selected via environment 'videomode'. Two different ways
1039 - "videomode=num" 'num' is a standard LiLo mode numbers.
1040 Following standard modes are supported (* is default):
1042 Colors 640x480 800x600 1024x768 1152x864 1280x1024
1043 -------------+---------------------------------------------
1044 8 bits | 0x301* 0x303 0x305 0x161 0x307
1045 15 bits | 0x310 0x313 0x316 0x162 0x319
1046 16 bits | 0x311 0x314 0x317 0x163 0x31A
1047 24 bits | 0x312 0x315 0x318 ? 0x31B
1048 -------------+---------------------------------------------
1049 (i.e. setenv videomode 317; saveenv; reset;)
1051 - "videomode=bootargs" all the video parameters are parsed
1052 from the bootargs. (See drivers/video/videomodes.c)
1055 CONFIG_VIDEO_SED13806
1056 Enable Epson SED13806 driver. This driver supports 8bpp
1057 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP
1058 or CONFIG_VIDEO_SED13806_16BPP
1063 Define this to enable a custom keyboard support.
1064 This simply calls drv_keyboard_init() which must be
1065 defined in your board-specific files.
1066 The only board using this so far is RBC823.
1068 - LCD Support: CONFIG_LCD
1070 Define this to enable LCD support (for output to LCD
1071 display); also select one of the supported displays
1072 by defining one of these:
1076 HITACHI TX09D70VM1CCA, 3.5", 240x320.
1078 CONFIG_NEC_NL6448AC33:
1080 NEC NL6448AC33-18. Active, color, single scan.
1082 CONFIG_NEC_NL6448BC20
1084 NEC NL6448BC20-08. 6.5", 640x480.
1085 Active, color, single scan.
1087 CONFIG_NEC_NL6448BC33_54
1089 NEC NL6448BC33-54. 10.4", 640x480.
1090 Active, color, single scan.
1094 Sharp 320x240. Active, color, single scan.
1095 It isn't 16x9, and I am not sure what it is.
1097 CONFIG_SHARP_LQ64D341
1099 Sharp LQ64D341 display, 640x480.
1100 Active, color, single scan.
1104 HLD1045 display, 640x480.
1105 Active, color, single scan.
1109 Optrex CBL50840-2 NF-FW 99 22 M5
1111 Hitachi LMG6912RPFC-00T
1115 320x240. Black & white.
1117 Normally display is black on white background; define
1118 CONFIG_SYS_WHITE_ON_BLACK to get it inverted.
1120 - Splash Screen Support: CONFIG_SPLASH_SCREEN
1122 If this option is set, the environment is checked for
1123 a variable "splashimage". If found, the usual display
1124 of logo, copyright and system information on the LCD
1125 is suppressed and the BMP image at the address
1126 specified in "splashimage" is loaded instead. The
1127 console is redirected to the "nulldev", too. This
1128 allows for a "silent" boot where a splash screen is
1129 loaded very quickly after power-on.
1131 CONFIG_SPLASH_SCREEN_ALIGN
1133 If this option is set the splash image can be freely positioned
1134 on the screen. Environment variable "splashpos" specifies the
1135 position as "x,y". If a positive number is given it is used as
1136 number of pixel from left/top. If a negative number is given it
1137 is used as number of pixel from right/bottom. You can also
1138 specify 'm' for centering the image.
1141 setenv splashpos m,m
1142 => image at center of screen
1144 setenv splashpos 30,20
1145 => image at x = 30 and y = 20
1147 setenv splashpos -10,m
1148 => vertically centered image
1149 at x = dspWidth - bmpWidth - 9
1151 - Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP
1153 If this option is set, additionally to standard BMP
1154 images, gzipped BMP images can be displayed via the
1155 splashscreen support or the bmp command.
1157 - Run length encoded BMP image (RLE8) support: CONFIG_VIDEO_BMP_RLE8
1159 If this option is set, 8-bit RLE compressed BMP images
1160 can be displayed via the splashscreen support or the
1163 - Compression support:
1166 If this option is set, support for bzip2 compressed
1167 images is included. If not, only uncompressed and gzip
1168 compressed images are supported.
1170 NOTE: the bzip2 algorithm requires a lot of RAM, so
1171 the malloc area (as defined by CONFIG_SYS_MALLOC_LEN) should
1176 If this option is set, support for lzma compressed
1179 Note: The LZMA algorithm adds between 2 and 4KB of code and it
1180 requires an amount of dynamic memory that is given by the
1183 (1846 + 768 << (lc + lp)) * sizeof(uint16)
1185 Where lc and lp stand for, respectively, Literal context bits
1186 and Literal pos bits.
1188 This value is upper-bounded by 14MB in the worst case. Anyway,
1189 for a ~4MB large kernel image, we have lc=3 and lp=0 for a
1190 total amount of (1846 + 768 << (3 + 0)) * 2 = ~41KB... that is
1191 a very small buffer.
1193 Use the lzmainfo tool to determinate the lc and lp values and
1194 then calculate the amount of needed dynamic memory (ensuring
1195 the appropriate CONFIG_SYS_MALLOC_LEN value).
1200 The address of PHY on MII bus.
1202 CONFIG_PHY_CLOCK_FREQ (ppc4xx)
1204 The clock frequency of the MII bus
1208 If this option is set, support for speed/duplex
1209 detection of gigabit PHY is included.
1211 CONFIG_PHY_RESET_DELAY
1213 Some PHY like Intel LXT971A need extra delay after
1214 reset before any MII register access is possible.
1215 For such PHY, set this option to the usec delay
1216 required. (minimum 300usec for LXT971A)
1218 CONFIG_PHY_CMD_DELAY (ppc4xx)
1220 Some PHY like Intel LXT971A need extra delay after
1221 command issued before MII status register can be read
1231 Define a default value for Ethernet address to use
1232 for the respective Ethernet interface, in case this
1233 is not determined automatically.
1238 Define a default value for the IP address to use for
1239 the default Ethernet interface, in case this is not
1240 determined through e.g. bootp.
1242 - Server IP address:
1245 Defines a default value for the IP address of a TFTP
1246 server to contact when using the "tftboot" command.
1248 CONFIG_KEEP_SERVERADDR
1250 Keeps the server's MAC address, in the env 'serveraddr'
1251 for passing to bootargs (like Linux's netconsole option)
1253 - Multicast TFTP Mode:
1256 Defines whether you want to support multicast TFTP as per
1257 rfc-2090; for example to work with atftp. Lets lots of targets
1258 tftp down the same boot image concurrently. Note: the Ethernet
1259 driver in use must provide a function: mcast() to join/leave a
1262 CONFIG_BOOTP_RANDOM_DELAY
1263 - BOOTP Recovery Mode:
1264 CONFIG_BOOTP_RANDOM_DELAY
1266 If you have many targets in a network that try to
1267 boot using BOOTP, you may want to avoid that all
1268 systems send out BOOTP requests at precisely the same
1269 moment (which would happen for instance at recovery
1270 from a power failure, when all systems will try to
1271 boot, thus flooding the BOOTP server. Defining
1272 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
1273 inserted before sending out BOOTP requests. The
1274 following delays are inserted then:
1276 1st BOOTP request: delay 0 ... 1 sec
1277 2nd BOOTP request: delay 0 ... 2 sec
1278 3rd BOOTP request: delay 0 ... 4 sec
1280 BOOTP requests: delay 0 ... 8 sec
1282 - DHCP Advanced Options:
1283 You can fine tune the DHCP functionality by defining
1284 CONFIG_BOOTP_* symbols:
1286 CONFIG_BOOTP_SUBNETMASK
1287 CONFIG_BOOTP_GATEWAY
1288 CONFIG_BOOTP_HOSTNAME
1289 CONFIG_BOOTP_NISDOMAIN
1290 CONFIG_BOOTP_BOOTPATH
1291 CONFIG_BOOTP_BOOTFILESIZE
1294 CONFIG_BOOTP_SEND_HOSTNAME
1295 CONFIG_BOOTP_NTPSERVER
1296 CONFIG_BOOTP_TIMEOFFSET
1297 CONFIG_BOOTP_VENDOREX
1299 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip
1300 environment variable, not the BOOTP server.
1302 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS
1303 serverip from a DHCP server, it is possible that more
1304 than one DNS serverip is offered to the client.
1305 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS
1306 serverip will be stored in the additional environment
1307 variable "dnsip2". The first DNS serverip is always
1308 stored in the variable "dnsip", when CONFIG_BOOTP_DNS
1311 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable
1312 to do a dynamic update of a DNS server. To do this, they
1313 need the hostname of the DHCP requester.
1314 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content
1315 of the "hostname" environment variable is passed as
1316 option 12 to the DHCP server.
1318 CONFIG_BOOTP_DHCP_REQUEST_DELAY
1320 A 32bit value in microseconds for a delay between
1321 receiving a "DHCP Offer" and sending the "DHCP Request".
1322 This fixes a problem with certain DHCP servers that don't
1323 respond 100% of the time to a "DHCP request". E.g. On an
1324 AT91RM9200 processor running at 180MHz, this delay needed
1325 to be *at least* 15,000 usec before a Windows Server 2003
1326 DHCP server would reply 100% of the time. I recommend at
1327 least 50,000 usec to be safe. The alternative is to hope
1328 that one of the retries will be successful but note that
1329 the DHCP timeout and retry process takes a longer than
1333 CONFIG_CDP_DEVICE_ID
1335 The device id used in CDP trigger frames.
1337 CONFIG_CDP_DEVICE_ID_PREFIX
1339 A two character string which is prefixed to the MAC address
1344 A printf format string which contains the ascii name of
1345 the port. Normally is set to "eth%d" which sets
1346 eth0 for the first Ethernet, eth1 for the second etc.
1348 CONFIG_CDP_CAPABILITIES
1350 A 32bit integer which indicates the device capabilities;
1351 0x00000010 for a normal host which does not forwards.
1355 An ascii string containing the version of the software.
1359 An ascii string containing the name of the platform.
1363 A 32bit integer sent on the trigger.
1365 CONFIG_CDP_POWER_CONSUMPTION
1367 A 16bit integer containing the power consumption of the
1368 device in .1 of milliwatts.
1370 CONFIG_CDP_APPLIANCE_VLAN_TYPE
1372 A byte containing the id of the VLAN.
1374 - Status LED: CONFIG_STATUS_LED
1376 Several configurations allow to display the current
1377 status using a LED. For instance, the LED will blink
1378 fast while running U-Boot code, stop blinking as
1379 soon as a reply to a BOOTP request was received, and
1380 start blinking slow once the Linux kernel is running
1381 (supported by a status LED driver in the Linux
1382 kernel). Defining CONFIG_STATUS_LED enables this
1385 - CAN Support: CONFIG_CAN_DRIVER
1387 Defining CONFIG_CAN_DRIVER enables CAN driver support
1388 on those systems that support this (optional)
1389 feature, like the TQM8xxL modules.
1391 - I2C Support: CONFIG_HARD_I2C | CONFIG_SOFT_I2C
1393 These enable I2C serial bus commands. Defining either of
1394 (but not both of) CONFIG_HARD_I2C or CONFIG_SOFT_I2C will
1395 include the appropriate I2C driver for the selected CPU.
1397 This will allow you to use i2c commands at the u-boot
1398 command line (as long as you set CONFIG_CMD_I2C in
1399 CONFIG_COMMANDS) and communicate with i2c based realtime
1400 clock chips. See common/cmd_i2c.c for a description of the
1401 command line interface.
1403 CONFIG_HARD_I2C selects a hardware I2C controller.
1405 CONFIG_SOFT_I2C configures u-boot to use a software (aka
1406 bit-banging) driver instead of CPM or similar hardware
1409 There are several other quantities that must also be
1410 defined when you define CONFIG_HARD_I2C or CONFIG_SOFT_I2C.
1412 In both cases you will need to define CONFIG_SYS_I2C_SPEED
1413 to be the frequency (in Hz) at which you wish your i2c bus
1414 to run and CONFIG_SYS_I2C_SLAVE to be the address of this node (ie
1415 the CPU's i2c node address).
1417 Now, the u-boot i2c code for the mpc8xx
1418 (arch/powerpc/cpu/mpc8xx/i2c.c) sets the CPU up as a master node
1419 and so its address should therefore be cleared to 0 (See,
1420 eg, MPC823e User's Manual p.16-473). So, set
1421 CONFIG_SYS_I2C_SLAVE to 0.
1423 CONFIG_SYS_I2C_INIT_MPC5XXX
1425 When a board is reset during an i2c bus transfer
1426 chips might think that the current transfer is still
1427 in progress. Reset the slave devices by sending start
1428 commands until the slave device responds.
1430 That's all that's required for CONFIG_HARD_I2C.
1432 If you use the software i2c interface (CONFIG_SOFT_I2C)
1433 then the following macros need to be defined (examples are
1434 from include/configs/lwmon.h):
1438 (Optional). Any commands necessary to enable the I2C
1439 controller or configure ports.
1441 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
1445 (Only for MPC8260 CPU). The I/O port to use (the code
1446 assumes both bits are on the same port). Valid values
1447 are 0..3 for ports A..D.
1451 The code necessary to make the I2C data line active
1452 (driven). If the data line is open collector, this
1455 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
1459 The code necessary to make the I2C data line tri-stated
1460 (inactive). If the data line is open collector, this
1463 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
1467 Code that returns TRUE if the I2C data line is high,
1470 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
1474 If <bit> is TRUE, sets the I2C data line high. If it
1475 is FALSE, it clears it (low).
1477 eg: #define I2C_SDA(bit) \
1478 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
1479 else immr->im_cpm.cp_pbdat &= ~PB_SDA
1483 If <bit> is TRUE, sets the I2C clock line high. If it
1484 is FALSE, it clears it (low).
1486 eg: #define I2C_SCL(bit) \
1487 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
1488 else immr->im_cpm.cp_pbdat &= ~PB_SCL
1492 This delay is invoked four times per clock cycle so this
1493 controls the rate of data transfer. The data rate thus
1494 is 1 / (I2C_DELAY * 4). Often defined to be something
1497 #define I2C_DELAY udelay(2)
1499 CONFIG_SOFT_I2C_GPIO_SCL / CONFIG_SOFT_I2C_GPIO_SDA
1501 If your arch supports the generic GPIO framework (asm/gpio.h),
1502 then you may alternatively define the two GPIOs that are to be
1503 used as SCL / SDA. Any of the previous I2C_xxx macros will
1504 have GPIO-based defaults assigned to them as appropriate.
1506 You should define these to the GPIO value as given directly to
1507 the generic GPIO functions.
1509 CONFIG_SYS_I2C_INIT_BOARD
1511 When a board is reset during an i2c bus transfer
1512 chips might think that the current transfer is still
1513 in progress. On some boards it is possible to access
1514 the i2c SCLK line directly, either by using the
1515 processor pin as a GPIO or by having a second pin
1516 connected to the bus. If this option is defined a
1517 custom i2c_init_board() routine in boards/xxx/board.c
1518 is run early in the boot sequence.
1520 CONFIG_SYS_I2C_BOARD_LATE_INIT
1522 An alternative to CONFIG_SYS_I2C_INIT_BOARD. If this option is
1523 defined a custom i2c_board_late_init() routine in
1524 boards/xxx/board.c is run AFTER the operations in i2c_init()
1525 is completed. This callpoint can be used to unreset i2c bus
1526 using CPU i2c controller register accesses for CPUs whose i2c
1527 controller provide such a method. It is called at the end of
1528 i2c_init() to allow i2c_init operations to setup the i2c bus
1529 controller on the CPU (e.g. setting bus speed & slave address).
1531 CONFIG_I2CFAST (PPC405GP|PPC405EP only)
1533 This option enables configuration of bi_iic_fast[] flags
1534 in u-boot bd_info structure based on u-boot environment
1535 variable "i2cfast". (see also i2cfast)
1537 CONFIG_I2C_MULTI_BUS
1539 This option allows the use of multiple I2C buses, each of which
1540 must have a controller. At any point in time, only one bus is
1541 active. To switch to a different bus, use the 'i2c dev' command.
1542 Note that bus numbering is zero-based.
1544 CONFIG_SYS_I2C_NOPROBES
1546 This option specifies a list of I2C devices that will be skipped
1547 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS
1548 is set, specify a list of bus-device pairs. Otherwise, specify
1549 a 1D array of device addresses
1552 #undef CONFIG_I2C_MULTI_BUS
1553 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68}
1555 will skip addresses 0x50 and 0x68 on a board with one I2C bus
1557 #define CONFIG_I2C_MULTI_BUS
1558 #define CONFIG_SYS_I2C_MULTI_NOPROBES {{0,0x50},{0,0x68},{1,0x54}}
1560 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1
1562 CONFIG_SYS_SPD_BUS_NUM
1564 If defined, then this indicates the I2C bus number for DDR SPD.
1565 If not defined, then U-Boot assumes that SPD is on I2C bus 0.
1567 CONFIG_SYS_RTC_BUS_NUM
1569 If defined, then this indicates the I2C bus number for the RTC.
1570 If not defined, then U-Boot assumes that RTC is on I2C bus 0.
1572 CONFIG_SYS_DTT_BUS_NUM
1574 If defined, then this indicates the I2C bus number for the DTT.
1575 If not defined, then U-Boot assumes that DTT is on I2C bus 0.
1577 CONFIG_SYS_I2C_DTT_ADDR:
1579 If defined, specifies the I2C address of the DTT device.
1580 If not defined, then U-Boot uses predefined value for
1581 specified DTT device.
1585 Define this option if you want to use Freescale's I2C driver in
1586 drivers/i2c/fsl_i2c.c.
1590 Define this option if you have I2C devices reached over 1 .. n
1591 I2C Muxes like the pca9544a. This option addes a new I2C
1592 Command "i2c bus [muxtype:muxaddr:muxchannel]" which adds a
1593 new I2C Bus to the existing I2C Busses. If you select the
1594 new Bus with "i2c dev", u-bbot sends first the commandos for
1595 the muxes to activate this new "bus".
1597 CONFIG_I2C_MULTI_BUS must be also defined, to use this
1601 Adding a new I2C Bus reached over 2 pca9544a muxes
1602 The First mux with address 70 and channel 6
1603 The Second mux with address 71 and channel 4
1605 => i2c bus pca9544a:70:6:pca9544a:71:4
1607 Use the "i2c bus" command without parameter, to get a list
1608 of I2C Busses with muxes:
1611 Busses reached over muxes:
1613 reached over Mux(es):
1616 reached over Mux(es):
1621 If you now switch to the new I2C Bus 3 with "i2c dev 3"
1622 u-boot sends First the Commando to the mux@70 to enable
1623 channel 6, and then the Commando to the mux@71 to enable
1626 After that, you can use the "normal" i2c commands as
1627 usual, to communicate with your I2C devices behind
1630 This option is actually implemented for the bitbanging
1631 algorithm in common/soft_i2c.c and for the Hardware I2C
1632 Bus on the MPC8260. But it should be not so difficult
1633 to add this option to other architectures.
1635 CONFIG_SOFT_I2C_READ_REPEATED_START
1637 defining this will force the i2c_read() function in
1638 the soft_i2c driver to perform an I2C repeated start
1639 between writing the address pointer and reading the
1640 data. If this define is omitted the default behaviour
1641 of doing a stop-start sequence will be used. Most I2C
1642 devices can use either method, but some require one or
1645 - SPI Support: CONFIG_SPI
1647 Enables SPI driver (so far only tested with
1648 SPI EEPROM, also an instance works with Crystal A/D and
1649 D/As on the SACSng board)
1653 Enables extended (16-bit) SPI EEPROM addressing.
1654 (symmetrical to CONFIG_I2C_X)
1658 Enables a software (bit-bang) SPI driver rather than
1659 using hardware support. This is a general purpose
1660 driver that only requires three general I/O port pins
1661 (two outputs, one input) to function. If this is
1662 defined, the board configuration must define several
1663 SPI configuration items (port pins to use, etc). For
1664 an example, see include/configs/sacsng.h.
1668 Enables a hardware SPI driver for general-purpose reads
1669 and writes. As with CONFIG_SOFT_SPI, the board configuration
1670 must define a list of chip-select function pointers.
1671 Currently supported on some MPC8xxx processors. For an
1672 example, see include/configs/mpc8349emds.h.
1676 Enables the driver for the SPI controllers on i.MX and MXC
1677 SoCs. Currently only i.MX31 is supported.
1679 - FPGA Support: CONFIG_FPGA
1681 Enables FPGA subsystem.
1683 CONFIG_FPGA_<vendor>
1685 Enables support for specific chip vendors.
1688 CONFIG_FPGA_<family>
1690 Enables support for FPGA family.
1691 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX)
1695 Specify the number of FPGA devices to support.
1697 CONFIG_SYS_FPGA_PROG_FEEDBACK
1699 Enable printing of hash marks during FPGA configuration.
1701 CONFIG_SYS_FPGA_CHECK_BUSY
1703 Enable checks on FPGA configuration interface busy
1704 status by the configuration function. This option
1705 will require a board or device specific function to
1710 If defined, a function that provides delays in the FPGA
1711 configuration driver.
1713 CONFIG_SYS_FPGA_CHECK_CTRLC
1714 Allow Control-C to interrupt FPGA configuration
1716 CONFIG_SYS_FPGA_CHECK_ERROR
1718 Check for configuration errors during FPGA bitfile
1719 loading. For example, abort during Virtex II
1720 configuration if the INIT_B line goes low (which
1721 indicated a CRC error).
1723 CONFIG_SYS_FPGA_WAIT_INIT
1725 Maximum time to wait for the INIT_B line to deassert
1726 after PROB_B has been deasserted during a Virtex II
1727 FPGA configuration sequence. The default time is 500
1730 CONFIG_SYS_FPGA_WAIT_BUSY
1732 Maximum time to wait for BUSY to deassert during
1733 Virtex II FPGA configuration. The default is 5 ms.
1735 CONFIG_SYS_FPGA_WAIT_CONFIG
1737 Time to wait after FPGA configuration. The default is
1740 - Configuration Management:
1743 If defined, this string will be added to the U-Boot
1744 version information (U_BOOT_VERSION)
1746 - Vendor Parameter Protection:
1748 U-Boot considers the values of the environment
1749 variables "serial#" (Board Serial Number) and
1750 "ethaddr" (Ethernet Address) to be parameters that
1751 are set once by the board vendor / manufacturer, and
1752 protects these variables from casual modification by
1753 the user. Once set, these variables are read-only,
1754 and write or delete attempts are rejected. You can
1755 change this behaviour:
1757 If CONFIG_ENV_OVERWRITE is #defined in your config
1758 file, the write protection for vendor parameters is
1759 completely disabled. Anybody can change or delete
1762 Alternatively, if you #define _both_ CONFIG_ETHADDR
1763 _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
1764 Ethernet address is installed in the environment,
1765 which can be changed exactly ONCE by the user. [The
1766 serial# is unaffected by this, i. e. it remains
1772 Define this variable to enable the reservation of
1773 "protected RAM", i. e. RAM which is not overwritten
1774 by U-Boot. Define CONFIG_PRAM to hold the number of
1775 kB you want to reserve for pRAM. You can overwrite
1776 this default value by defining an environment
1777 variable "pram" to the number of kB you want to
1778 reserve. Note that the board info structure will
1779 still show the full amount of RAM. If pRAM is
1780 reserved, a new environment variable "mem" will
1781 automatically be defined to hold the amount of
1782 remaining RAM in a form that can be passed as boot
1783 argument to Linux, for instance like that:
1785 setenv bootargs ... mem=\${mem}
1788 This way you can tell Linux not to use this memory,
1789 either, which results in a memory region that will
1790 not be affected by reboots.
1792 *WARNING* If your board configuration uses automatic
1793 detection of the RAM size, you must make sure that
1794 this memory test is non-destructive. So far, the
1795 following board configurations are known to be
1798 ETX094, IVMS8, IVML24, SPD8xx, TQM8xxL,
1799 HERMES, IP860, RPXlite, LWMON, LANTEC,
1805 Define this variable to stop the system in case of a
1806 fatal error, so that you have to reset it manually.
1807 This is probably NOT a good idea for an embedded
1808 system where you want the system to reboot
1809 automatically as fast as possible, but it may be
1810 useful during development since you can try to debug
1811 the conditions that lead to the situation.
1813 CONFIG_NET_RETRY_COUNT
1815 This variable defines the number of retries for
1816 network operations like ARP, RARP, TFTP, or BOOTP
1817 before giving up the operation. If not defined, a
1818 default value of 5 is used.
1822 Timeout waiting for an ARP reply in milliseconds.
1824 - Command Interpreter:
1825 CONFIG_AUTO_COMPLETE
1827 Enable auto completion of commands using TAB.
1829 Note that this feature has NOT been implemented yet
1830 for the "hush" shell.
1833 CONFIG_SYS_HUSH_PARSER
1835 Define this variable to enable the "hush" shell (from
1836 Busybox) as command line interpreter, thus enabling
1837 powerful command line syntax like
1838 if...then...else...fi conditionals or `&&' and '||'
1839 constructs ("shell scripts").
1841 If undefined, you get the old, much simpler behaviour
1842 with a somewhat smaller memory footprint.
1845 CONFIG_SYS_PROMPT_HUSH_PS2
1847 This defines the secondary prompt string, which is
1848 printed when the command interpreter needs more input
1849 to complete a command. Usually "> ".
1853 In the current implementation, the local variables
1854 space and global environment variables space are
1855 separated. Local variables are those you define by
1856 simply typing `name=value'. To access a local
1857 variable later on, you have write `$name' or
1858 `${name}'; to execute the contents of a variable
1859 directly type `$name' at the command prompt.
1861 Global environment variables are those you use
1862 setenv/printenv to work with. To run a command stored
1863 in such a variable, you need to use the run command,
1864 and you must not use the '$' sign to access them.
1866 To store commands and special characters in a
1867 variable, please use double quotation marks
1868 surrounding the whole text of the variable, instead
1869 of the backslashes before semicolons and special
1872 - Commandline Editing and History:
1873 CONFIG_CMDLINE_EDITING
1875 Enable editing and History functions for interactive
1876 commandline input operations
1878 - Default Environment:
1879 CONFIG_EXTRA_ENV_SETTINGS
1881 Define this to contain any number of null terminated
1882 strings (variable = value pairs) that will be part of
1883 the default environment compiled into the boot image.
1885 For example, place something like this in your
1886 board's config file:
1888 #define CONFIG_EXTRA_ENV_SETTINGS \
1892 Warning: This method is based on knowledge about the
1893 internal format how the environment is stored by the
1894 U-Boot code. This is NOT an official, exported
1895 interface! Although it is unlikely that this format
1896 will change soon, there is no guarantee either.
1897 You better know what you are doing here.
1899 Note: overly (ab)use of the default environment is
1900 discouraged. Make sure to check other ways to preset
1901 the environment like the "source" command or the
1904 - DataFlash Support:
1905 CONFIG_HAS_DATAFLASH
1907 Defining this option enables DataFlash features and
1908 allows to read/write in Dataflash via the standard
1911 - SystemACE Support:
1914 Adding this option adds support for Xilinx SystemACE
1915 chips attached via some sort of local bus. The address
1916 of the chip must also be defined in the
1917 CONFIG_SYS_SYSTEMACE_BASE macro. For example:
1919 #define CONFIG_SYSTEMACE
1920 #define CONFIG_SYS_SYSTEMACE_BASE 0xf0000000
1922 When SystemACE support is added, the "ace" device type
1923 becomes available to the fat commands, i.e. fatls.
1925 - TFTP Fixed UDP Port:
1928 If this is defined, the environment variable tftpsrcp
1929 is used to supply the TFTP UDP source port value.
1930 If tftpsrcp isn't defined, the normal pseudo-random port
1931 number generator is used.
1933 Also, the environment variable tftpdstp is used to supply
1934 the TFTP UDP destination port value. If tftpdstp isn't
1935 defined, the normal port 69 is used.
1937 The purpose for tftpsrcp is to allow a TFTP server to
1938 blindly start the TFTP transfer using the pre-configured
1939 target IP address and UDP port. This has the effect of
1940 "punching through" the (Windows XP) firewall, allowing
1941 the remainder of the TFTP transfer to proceed normally.
1942 A better solution is to properly configure the firewall,
1943 but sometimes that is not allowed.
1945 - Show boot progress:
1946 CONFIG_SHOW_BOOT_PROGRESS
1948 Defining this option allows to add some board-
1949 specific code (calling a user-provided function
1950 "show_boot_progress(int)") that enables you to show
1951 the system's boot progress on some display (for
1952 example, some LED's) on your board. At the moment,
1953 the following checkpoints are implemented:
1955 Legacy uImage format:
1958 1 common/cmd_bootm.c before attempting to boot an image
1959 -1 common/cmd_bootm.c Image header has bad magic number
1960 2 common/cmd_bootm.c Image header has correct magic number
1961 -2 common/cmd_bootm.c Image header has bad checksum
1962 3 common/cmd_bootm.c Image header has correct checksum
1963 -3 common/cmd_bootm.c Image data has bad checksum
1964 4 common/cmd_bootm.c Image data has correct checksum
1965 -4 common/cmd_bootm.c Image is for unsupported architecture
1966 5 common/cmd_bootm.c Architecture check OK
1967 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi)
1968 6 common/cmd_bootm.c Image Type check OK
1969 -6 common/cmd_bootm.c gunzip uncompression error
1970 -7 common/cmd_bootm.c Unimplemented compression type
1971 7 common/cmd_bootm.c Uncompression OK
1972 8 common/cmd_bootm.c No uncompress/copy overwrite error
1973 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX)
1975 9 common/image.c Start initial ramdisk verification
1976 -10 common/image.c Ramdisk header has bad magic number
1977 -11 common/image.c Ramdisk header has bad checksum
1978 10 common/image.c Ramdisk header is OK
1979 -12 common/image.c Ramdisk data has bad checksum
1980 11 common/image.c Ramdisk data has correct checksum
1981 12 common/image.c Ramdisk verification complete, start loading
1982 -13 common/image.c Wrong Image Type (not PPC Linux ramdisk)
1983 13 common/image.c Start multifile image verification
1984 14 common/image.c No initial ramdisk, no multifile, continue.
1986 15 arch/<arch>/lib/bootm.c All preparation done, transferring control to OS
1988 -30 arch/powerpc/lib/board.c Fatal error, hang the system
1989 -31 post/post.c POST test failed, detected by post_output_backlog()
1990 -32 post/post.c POST test failed, detected by post_run_single()
1992 34 common/cmd_doc.c before loading a Image from a DOC device
1993 -35 common/cmd_doc.c Bad usage of "doc" command
1994 35 common/cmd_doc.c correct usage of "doc" command
1995 -36 common/cmd_doc.c No boot device
1996 36 common/cmd_doc.c correct boot device
1997 -37 common/cmd_doc.c Unknown Chip ID on boot device
1998 37 common/cmd_doc.c correct chip ID found, device available
1999 -38 common/cmd_doc.c Read Error on boot device
2000 38 common/cmd_doc.c reading Image header from DOC device OK
2001 -39 common/cmd_doc.c Image header has bad magic number
2002 39 common/cmd_doc.c Image header has correct magic number
2003 -40 common/cmd_doc.c Error reading Image from DOC device
2004 40 common/cmd_doc.c Image header has correct magic number
2005 41 common/cmd_ide.c before loading a Image from a IDE device
2006 -42 common/cmd_ide.c Bad usage of "ide" command
2007 42 common/cmd_ide.c correct usage of "ide" command
2008 -43 common/cmd_ide.c No boot device
2009 43 common/cmd_ide.c boot device found
2010 -44 common/cmd_ide.c Device not available
2011 44 common/cmd_ide.c Device available
2012 -45 common/cmd_ide.c wrong partition selected
2013 45 common/cmd_ide.c partition selected
2014 -46 common/cmd_ide.c Unknown partition table
2015 46 common/cmd_ide.c valid partition table found
2016 -47 common/cmd_ide.c Invalid partition type
2017 47 common/cmd_ide.c correct partition type
2018 -48 common/cmd_ide.c Error reading Image Header on boot device
2019 48 common/cmd_ide.c reading Image Header from IDE device OK
2020 -49 common/cmd_ide.c Image header has bad magic number
2021 49 common/cmd_ide.c Image header has correct magic number
2022 -50 common/cmd_ide.c Image header has bad checksum
2023 50 common/cmd_ide.c Image header has correct checksum
2024 -51 common/cmd_ide.c Error reading Image from IDE device
2025 51 common/cmd_ide.c reading Image from IDE device OK
2026 52 common/cmd_nand.c before loading a Image from a NAND device
2027 -53 common/cmd_nand.c Bad usage of "nand" command
2028 53 common/cmd_nand.c correct usage of "nand" command
2029 -54 common/cmd_nand.c No boot device
2030 54 common/cmd_nand.c boot device found
2031 -55 common/cmd_nand.c Unknown Chip ID on boot device
2032 55 common/cmd_nand.c correct chip ID found, device available
2033 -56 common/cmd_nand.c Error reading Image Header on boot device
2034 56 common/cmd_nand.c reading Image Header from NAND device OK
2035 -57 common/cmd_nand.c Image header has bad magic number
2036 57 common/cmd_nand.c Image header has correct magic number
2037 -58 common/cmd_nand.c Error reading Image from NAND device
2038 58 common/cmd_nand.c reading Image from NAND device OK
2040 -60 common/env_common.c Environment has a bad CRC, using default
2042 64 net/eth.c starting with Ethernet configuration.
2043 -64 net/eth.c no Ethernet found.
2044 65 net/eth.c Ethernet found.
2046 -80 common/cmd_net.c usage wrong
2047 80 common/cmd_net.c before calling NetLoop()
2048 -81 common/cmd_net.c some error in NetLoop() occurred
2049 81 common/cmd_net.c NetLoop() back without error
2050 -82 common/cmd_net.c size == 0 (File with size 0 loaded)
2051 82 common/cmd_net.c trying automatic boot
2052 83 common/cmd_net.c running "source" command
2053 -83 common/cmd_net.c some error in automatic boot or "source" command
2054 84 common/cmd_net.c end without errors
2059 100 common/cmd_bootm.c Kernel FIT Image has correct format
2060 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format
2061 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration
2062 -101 common/cmd_bootm.c Can't get configuration for kernel subimage
2063 102 common/cmd_bootm.c Kernel unit name specified
2064 -103 common/cmd_bootm.c Can't get kernel subimage node offset
2065 103 common/cmd_bootm.c Found configuration node
2066 104 common/cmd_bootm.c Got kernel subimage node offset
2067 -104 common/cmd_bootm.c Kernel subimage hash verification failed
2068 105 common/cmd_bootm.c Kernel subimage hash verification OK
2069 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture
2070 106 common/cmd_bootm.c Architecture check OK
2071 -106 common/cmd_bootm.c Kernel subimage has wrong type
2072 107 common/cmd_bootm.c Kernel subimage type OK
2073 -107 common/cmd_bootm.c Can't get kernel subimage data/size
2074 108 common/cmd_bootm.c Got kernel subimage data/size
2075 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT)
2076 -109 common/cmd_bootm.c Can't get kernel subimage type
2077 -110 common/cmd_bootm.c Can't get kernel subimage comp
2078 -111 common/cmd_bootm.c Can't get kernel subimage os
2079 -112 common/cmd_bootm.c Can't get kernel subimage load address
2080 -113 common/cmd_bootm.c Image uncompress/copy overwrite error
2082 120 common/image.c Start initial ramdisk verification
2083 -120 common/image.c Ramdisk FIT image has incorrect format
2084 121 common/image.c Ramdisk FIT image has correct format
2085 122 common/image.c No ramdisk subimage unit name, using configuration
2086 -122 common/image.c Can't get configuration for ramdisk subimage
2087 123 common/image.c Ramdisk unit name specified
2088 -124 common/image.c Can't get ramdisk subimage node offset
2089 125 common/image.c Got ramdisk subimage node offset
2090 -125 common/image.c Ramdisk subimage hash verification failed
2091 126 common/image.c Ramdisk subimage hash verification OK
2092 -126 common/image.c Ramdisk subimage for unsupported architecture
2093 127 common/image.c Architecture check OK
2094 -127 common/image.c Can't get ramdisk subimage data/size
2095 128 common/image.c Got ramdisk subimage data/size
2096 129 common/image.c Can't get ramdisk load address
2097 -129 common/image.c Got ramdisk load address
2099 -130 common/cmd_doc.c Incorrect FIT image format
2100 131 common/cmd_doc.c FIT image format OK
2102 -140 common/cmd_ide.c Incorrect FIT image format
2103 141 common/cmd_ide.c FIT image format OK
2105 -150 common/cmd_nand.c Incorrect FIT image format
2106 151 common/cmd_nand.c FIT image format OK
2108 - Automatic software updates via TFTP server
2110 CONFIG_UPDATE_TFTP_CNT_MAX
2111 CONFIG_UPDATE_TFTP_MSEC_MAX
2113 These options enable and control the auto-update feature;
2114 for a more detailed description refer to doc/README.update.
2116 - MTD Support (mtdparts command, UBI support)
2119 Adds the MTD device infrastructure from the Linux kernel.
2120 Needed for mtdparts command support.
2122 CONFIG_MTD_PARTITIONS
2124 Adds the MTD partitioning infrastructure from the Linux
2125 kernel. Needed for UBI support.
2131 [so far only for SMDK2400 and TRAB boards]
2133 - Modem support enable:
2134 CONFIG_MODEM_SUPPORT
2136 - RTS/CTS Flow control enable:
2139 - Modem debug support:
2140 CONFIG_MODEM_SUPPORT_DEBUG
2142 Enables debugging stuff (char screen[1024], dbg())
2143 for modem support. Useful only with BDI2000.
2145 - Interrupt support (PPC):
2147 There are common interrupt_init() and timer_interrupt()
2148 for all PPC archs. interrupt_init() calls interrupt_init_cpu()
2149 for CPU specific initialization. interrupt_init_cpu()
2150 should set decrementer_count to appropriate value. If
2151 CPU resets decrementer automatically after interrupt
2152 (ppc4xx) it should set decrementer_count to zero.
2153 timer_interrupt() calls timer_interrupt_cpu() for CPU
2154 specific handling. If board has watchdog / status_led
2155 / other_activity_monitor it works automatically from
2156 general timer_interrupt().
2160 In the target system modem support is enabled when a
2161 specific key (key combination) is pressed during
2162 power-on. Otherwise U-Boot will boot normally
2163 (autoboot). The key_pressed() function is called from
2164 board_init(). Currently key_pressed() is a dummy
2165 function, returning 1 and thus enabling modem
2168 If there are no modem init strings in the
2169 environment, U-Boot proceed to autoboot; the
2170 previous output (banner, info printfs) will be
2173 See also: doc/README.Modem
2176 Configuration Settings:
2177 -----------------------
2179 - CONFIG_SYS_LONGHELP: Defined when you want long help messages included;
2180 undefine this when you're short of memory.
2182 - CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default
2183 width of the commands listed in the 'help' command output.
2185 - CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to
2186 prompt for user input.
2188 - CONFIG_SYS_CBSIZE: Buffer size for input from the Console
2190 - CONFIG_SYS_PBSIZE: Buffer size for Console output
2192 - CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands
2194 - CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to
2195 the application (usually a Linux kernel) when it is
2198 - CONFIG_SYS_BAUDRATE_TABLE:
2199 List of legal baudrate settings for this board.
2201 - CONFIG_SYS_CONSOLE_INFO_QUIET
2202 Suppress display of console information at boot.
2204 - CONFIG_SYS_CONSOLE_IS_IN_ENV
2205 If the board specific function
2206 extern int overwrite_console (void);
2207 returns 1, the stdin, stderr and stdout are switched to the
2208 serial port, else the settings in the environment are used.
2210 - CONFIG_SYS_CONSOLE_OVERWRITE_ROUTINE
2211 Enable the call to overwrite_console().
2213 - CONFIG_SYS_CONSOLE_ENV_OVERWRITE
2214 Enable overwrite of previous console environment settings.
2216 - CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END:
2217 Begin and End addresses of the area used by the
2220 - CONFIG_SYS_ALT_MEMTEST:
2221 Enable an alternate, more extensive memory test.
2223 - CONFIG_SYS_MEMTEST_SCRATCH:
2224 Scratch address used by the alternate memory test
2225 You only need to set this if address zero isn't writeable
2227 - CONFIG_SYS_MEM_TOP_HIDE (PPC only):
2228 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header,
2229 this specified memory area will get subtracted from the top
2230 (end) of RAM and won't get "touched" at all by U-Boot. By
2231 fixing up gd->ram_size the Linux kernel should gets passed
2232 the now "corrected" memory size and won't touch it either.
2233 This should work for arch/ppc and arch/powerpc. Only Linux
2234 board ports in arch/powerpc with bootwrapper support that
2235 recalculate the memory size from the SDRAM controller setup
2236 will have to get fixed in Linux additionally.
2238 This option can be used as a workaround for the 440EPx/GRx
2239 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't
2242 WARNING: Please make sure that this value is a multiple of
2243 the Linux page size (normally 4k). If this is not the case,
2244 then the end address of the Linux memory will be located at a
2245 non page size aligned address and this could cause major
2248 - CONFIG_SYS_TFTP_LOADADDR:
2249 Default load address for network file downloads
2251 - CONFIG_SYS_LOADS_BAUD_CHANGE:
2252 Enable temporary baudrate change while serial download
2254 - CONFIG_SYS_SDRAM_BASE:
2255 Physical start address of SDRAM. _Must_ be 0 here.
2257 - CONFIG_SYS_MBIO_BASE:
2258 Physical start address of Motherboard I/O (if using a
2261 - CONFIG_SYS_FLASH_BASE:
2262 Physical start address of Flash memory.
2264 - CONFIG_SYS_MONITOR_BASE:
2265 Physical start address of boot monitor code (set by
2266 make config files to be same as the text base address
2267 (CONFIG_SYS_TEXT_BASE) used when linking) - same as
2268 CONFIG_SYS_FLASH_BASE when booting from flash.
2270 - CONFIG_SYS_MONITOR_LEN:
2271 Size of memory reserved for monitor code, used to
2272 determine _at_compile_time_ (!) if the environment is
2273 embedded within the U-Boot image, or in a separate
2276 - CONFIG_SYS_MALLOC_LEN:
2277 Size of DRAM reserved for malloc() use.
2279 - CONFIG_SYS_BOOTM_LEN:
2280 Normally compressed uImages are limited to an
2281 uncompressed size of 8 MBytes. If this is not enough,
2282 you can define CONFIG_SYS_BOOTM_LEN in your board config file
2283 to adjust this setting to your needs.
2285 - CONFIG_SYS_BOOTMAPSZ:
2286 Maximum size of memory mapped by the startup code of
2287 the Linux kernel; all data that must be processed by
2288 the Linux kernel (bd_info, boot arguments, FDT blob if
2289 used) must be put below this limit, unless "bootm_low"
2290 enviroment variable is defined and non-zero. In such case
2291 all data for the Linux kernel must be between "bootm_low"
2292 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ.
2294 - CONFIG_SYS_BOOT_RAMDISK_HIGH:
2295 Enable initrd_high functionality. If defined then the
2296 initrd_high feature is enabled and the bootm ramdisk subcommand
2299 - CONFIG_SYS_BOOT_GET_CMDLINE:
2300 Enables allocating and saving kernel cmdline in space between
2301 "bootm_low" and "bootm_low" + BOOTMAPSZ.
2303 - CONFIG_SYS_BOOT_GET_KBD:
2304 Enables allocating and saving a kernel copy of the bd_info in
2305 space between "bootm_low" and "bootm_low" + BOOTMAPSZ.
2307 - CONFIG_SYS_MAX_FLASH_BANKS:
2308 Max number of Flash memory banks
2310 - CONFIG_SYS_MAX_FLASH_SECT:
2311 Max number of sectors on a Flash chip
2313 - CONFIG_SYS_FLASH_ERASE_TOUT:
2314 Timeout for Flash erase operations (in ms)
2316 - CONFIG_SYS_FLASH_WRITE_TOUT:
2317 Timeout for Flash write operations (in ms)
2319 - CONFIG_SYS_FLASH_LOCK_TOUT
2320 Timeout for Flash set sector lock bit operation (in ms)
2322 - CONFIG_SYS_FLASH_UNLOCK_TOUT
2323 Timeout for Flash clear lock bits operation (in ms)
2325 - CONFIG_SYS_FLASH_PROTECTION
2326 If defined, hardware flash sectors protection is used
2327 instead of U-Boot software protection.
2329 - CONFIG_SYS_DIRECT_FLASH_TFTP:
2331 Enable TFTP transfers directly to flash memory;
2332 without this option such a download has to be
2333 performed in two steps: (1) download to RAM, and (2)
2334 copy from RAM to flash.
2336 The two-step approach is usually more reliable, since
2337 you can check if the download worked before you erase
2338 the flash, but in some situations (when system RAM is
2339 too limited to allow for a temporary copy of the
2340 downloaded image) this option may be very useful.
2342 - CONFIG_SYS_FLASH_CFI:
2343 Define if the flash driver uses extra elements in the
2344 common flash structure for storing flash geometry.
2346 - CONFIG_FLASH_CFI_DRIVER
2347 This option also enables the building of the cfi_flash driver
2348 in the drivers directory
2350 - CONFIG_FLASH_CFI_MTD
2351 This option enables the building of the cfi_mtd driver
2352 in the drivers directory. The driver exports CFI flash
2355 - CONFIG_SYS_FLASH_USE_BUFFER_WRITE
2356 Use buffered writes to flash.
2358 - CONFIG_FLASH_SPANSION_S29WS_N
2359 s29ws-n MirrorBit flash has non-standard addresses for buffered
2362 - CONFIG_SYS_FLASH_QUIET_TEST
2363 If this option is defined, the common CFI flash doesn't
2364 print it's warning upon not recognized FLASH banks. This
2365 is useful, if some of the configured banks are only
2366 optionally available.
2368 - CONFIG_FLASH_SHOW_PROGRESS
2369 If defined (must be an integer), print out countdown
2370 digits and dots. Recommended value: 45 (9..1) for 80
2371 column displays, 15 (3..1) for 40 column displays.
2373 - CONFIG_SYS_RX_ETH_BUFFER:
2374 Defines the number of Ethernet receive buffers. On some
2375 Ethernet controllers it is recommended to set this value
2376 to 8 or even higher (EEPRO100 or 405 EMAC), since all
2377 buffers can be full shortly after enabling the interface
2378 on high Ethernet traffic.
2379 Defaults to 4 if not defined.
2381 - CONFIG_ENV_MAX_ENTRIES
2383 Maximum number of entries in the hash table that is used
2384 internally to store the environment settings. The default
2385 setting is supposed to be generous and should work in most
2386 cases. This setting can be used to tune behaviour; see
2387 lib/hashtable.c for details.
2389 The following definitions that deal with the placement and management
2390 of environment data (variable area); in general, we support the
2391 following configurations:
2393 - CONFIG_ENV_IS_IN_FLASH:
2395 Define this if the environment is in flash memory.
2397 a) The environment occupies one whole flash sector, which is
2398 "embedded" in the text segment with the U-Boot code. This
2399 happens usually with "bottom boot sector" or "top boot
2400 sector" type flash chips, which have several smaller
2401 sectors at the start or the end. For instance, such a
2402 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In
2403 such a case you would place the environment in one of the
2404 4 kB sectors - with U-Boot code before and after it. With
2405 "top boot sector" type flash chips, you would put the
2406 environment in one of the last sectors, leaving a gap
2407 between U-Boot and the environment.
2409 - CONFIG_ENV_OFFSET:
2411 Offset of environment data (variable area) to the
2412 beginning of flash memory; for instance, with bottom boot
2413 type flash chips the second sector can be used: the offset
2414 for this sector is given here.
2416 CONFIG_ENV_OFFSET is used relative to CONFIG_SYS_FLASH_BASE.
2420 This is just another way to specify the start address of
2421 the flash sector containing the environment (instead of
2424 - CONFIG_ENV_SECT_SIZE:
2426 Size of the sector containing the environment.
2429 b) Sometimes flash chips have few, equal sized, BIG sectors.
2430 In such a case you don't want to spend a whole sector for
2435 If you use this in combination with CONFIG_ENV_IS_IN_FLASH
2436 and CONFIG_ENV_SECT_SIZE, you can specify to use only a part
2437 of this flash sector for the environment. This saves
2438 memory for the RAM copy of the environment.
2440 It may also save flash memory if you decide to use this
2441 when your environment is "embedded" within U-Boot code,
2442 since then the remainder of the flash sector could be used
2443 for U-Boot code. It should be pointed out that this is
2444 STRONGLY DISCOURAGED from a robustness point of view:
2445 updating the environment in flash makes it always
2446 necessary to erase the WHOLE sector. If something goes
2447 wrong before the contents has been restored from a copy in
2448 RAM, your target system will be dead.
2450 - CONFIG_ENV_ADDR_REDUND
2451 CONFIG_ENV_SIZE_REDUND
2453 These settings describe a second storage area used to hold
2454 a redundant copy of the environment data, so that there is
2455 a valid backup copy in case there is a power failure during
2456 a "saveenv" operation.
2458 BE CAREFUL! Any changes to the flash layout, and some changes to the
2459 source code will make it necessary to adapt <board>/u-boot.lds*
2463 - CONFIG_ENV_IS_IN_NVRAM:
2465 Define this if you have some non-volatile memory device
2466 (NVRAM, battery buffered SRAM) which you want to use for the
2472 These two #defines are used to determine the memory area you
2473 want to use for environment. It is assumed that this memory
2474 can just be read and written to, without any special
2477 BE CAREFUL! The first access to the environment happens quite early
2478 in U-Boot initalization (when we try to get the setting of for the
2479 console baudrate). You *MUST* have mapped your NVRAM area then, or
2482 Please note that even with NVRAM we still use a copy of the
2483 environment in RAM: we could work on NVRAM directly, but we want to
2484 keep settings there always unmodified except somebody uses "saveenv"
2485 to save the current settings.
2488 - CONFIG_ENV_IS_IN_EEPROM:
2490 Use this if you have an EEPROM or similar serial access
2491 device and a driver for it.
2493 - CONFIG_ENV_OFFSET:
2496 These two #defines specify the offset and size of the
2497 environment area within the total memory of your EEPROM.
2499 - CONFIG_SYS_I2C_EEPROM_ADDR:
2500 If defined, specified the chip address of the EEPROM device.
2501 The default address is zero.
2503 - CONFIG_SYS_EEPROM_PAGE_WRITE_BITS:
2504 If defined, the number of bits used to address bytes in a
2505 single page in the EEPROM device. A 64 byte page, for example
2506 would require six bits.
2508 - CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS:
2509 If defined, the number of milliseconds to delay between
2510 page writes. The default is zero milliseconds.
2512 - CONFIG_SYS_I2C_EEPROM_ADDR_LEN:
2513 The length in bytes of the EEPROM memory array address. Note
2514 that this is NOT the chip address length!
2516 - CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW:
2517 EEPROM chips that implement "address overflow" are ones
2518 like Catalyst 24WC04/08/16 which has 9/10/11 bits of
2519 address and the extra bits end up in the "chip address" bit
2520 slots. This makes a 24WC08 (1Kbyte) chip look like four 256
2523 Note that we consider the length of the address field to
2524 still be one byte because the extra address bits are hidden
2525 in the chip address.
2527 - CONFIG_SYS_EEPROM_SIZE:
2528 The size in bytes of the EEPROM device.
2530 - CONFIG_ENV_EEPROM_IS_ON_I2C
2531 define this, if you have I2C and SPI activated, and your
2532 EEPROM, which holds the environment, is on the I2C bus.
2534 - CONFIG_I2C_ENV_EEPROM_BUS
2535 if you have an Environment on an EEPROM reached over
2536 I2C muxes, you can define here, how to reach this
2537 EEPROM. For example:
2539 #define CONFIG_I2C_ENV_EEPROM_BUS "pca9547:70:d\0"
2541 EEPROM which holds the environment, is reached over
2542 a pca9547 i2c mux with address 0x70, channel 3.
2544 - CONFIG_ENV_IS_IN_DATAFLASH:
2546 Define this if you have a DataFlash memory device which you
2547 want to use for the environment.
2549 - CONFIG_ENV_OFFSET:
2553 These three #defines specify the offset and size of the
2554 environment area within the total memory of your DataFlash placed
2555 at the specified address.
2557 - CONFIG_ENV_IS_IN_NAND:
2559 Define this if you have a NAND device which you want to use
2560 for the environment.
2562 - CONFIG_ENV_OFFSET:
2565 These two #defines specify the offset and size of the environment
2566 area within the first NAND device. CONFIG_ENV_OFFSET must be
2567 aligned to an erase block boundary.
2569 - CONFIG_ENV_OFFSET_REDUND (optional):
2571 This setting describes a second storage area of CONFIG_ENV_SIZE
2572 size used to hold a redundant copy of the environment data, so
2573 that there is a valid backup copy in case there is a power failure
2574 during a "saveenv" operation. CONFIG_ENV_OFFSET_RENDUND must be
2575 aligned to an erase block boundary.
2577 - CONFIG_ENV_RANGE (optional):
2579 Specifies the length of the region in which the environment
2580 can be written. This should be a multiple of the NAND device's
2581 block size. Specifying a range with more erase blocks than
2582 are needed to hold CONFIG_ENV_SIZE allows bad blocks within
2583 the range to be avoided.
2585 - CONFIG_ENV_OFFSET_OOB (optional):
2587 Enables support for dynamically retrieving the offset of the
2588 environment from block zero's out-of-band data. The
2589 "nand env.oob" command can be used to record this offset.
2590 Currently, CONFIG_ENV_OFFSET_REDUND is not supported when
2591 using CONFIG_ENV_OFFSET_OOB.
2593 - CONFIG_NAND_ENV_DST
2595 Defines address in RAM to which the nand_spl code should copy the
2596 environment. If redundant environment is used, it will be copied to
2597 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE.
2599 - CONFIG_SYS_SPI_INIT_OFFSET
2601 Defines offset to the initial SPI buffer area in DPRAM. The
2602 area is used at an early stage (ROM part) if the environment
2603 is configured to reside in the SPI EEPROM: We need a 520 byte
2604 scratch DPRAM area. It is used between the two initialization
2605 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems
2606 to be a good choice since it makes it far enough from the
2607 start of the data area as well as from the stack pointer.
2609 Please note that the environment is read-only until the monitor
2610 has been relocated to RAM and a RAM copy of the environment has been
2611 created; also, when using EEPROM you will have to use getenv_f()
2612 until then to read environment variables.
2614 The environment is protected by a CRC32 checksum. Before the monitor
2615 is relocated into RAM, as a result of a bad CRC you will be working
2616 with the compiled-in default environment - *silently*!!! [This is
2617 necessary, because the first environment variable we need is the
2618 "baudrate" setting for the console - if we have a bad CRC, we don't
2619 have any device yet where we could complain.]
2621 Note: once the monitor has been relocated, then it will complain if
2622 the default environment is used; a new CRC is computed as soon as you
2623 use the "saveenv" command to store a valid environment.
2625 - CONFIG_SYS_FAULT_ECHO_LINK_DOWN:
2626 Echo the inverted Ethernet link state to the fault LED.
2628 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR
2629 also needs to be defined.
2631 - CONFIG_SYS_FAULT_MII_ADDR:
2632 MII address of the PHY to check for the Ethernet link state.
2634 - CONFIG_NS16550_MIN_FUNCTIONS:
2635 Define this if you desire to only have use of the NS16550_init
2636 and NS16550_putc functions for the serial driver located at
2637 drivers/serial/ns16550.c. This option is useful for saving
2638 space for already greatly restricted images, including but not
2639 limited to NAND_SPL configurations.
2641 Low Level (hardware related) configuration options:
2642 ---------------------------------------------------
2644 - CONFIG_SYS_CACHELINE_SIZE:
2645 Cache Line Size of the CPU.
2647 - CONFIG_SYS_DEFAULT_IMMR:
2648 Default address of the IMMR after system reset.
2650 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU,
2651 and RPXsuper) to be able to adjust the position of
2652 the IMMR register after a reset.
2654 - Floppy Disk Support:
2655 CONFIG_SYS_FDC_DRIVE_NUMBER
2657 the default drive number (default value 0)
2659 CONFIG_SYS_ISA_IO_STRIDE
2661 defines the spacing between FDC chipset registers
2664 CONFIG_SYS_ISA_IO_OFFSET
2666 defines the offset of register from address. It
2667 depends on which part of the data bus is connected to
2668 the FDC chipset. (default value 0)
2670 If CONFIG_SYS_ISA_IO_STRIDE CONFIG_SYS_ISA_IO_OFFSET and
2671 CONFIG_SYS_FDC_DRIVE_NUMBER are undefined, they take their
2674 if CONFIG_SYS_FDC_HW_INIT is defined, then the function
2675 fdc_hw_init() is called at the beginning of the FDC
2676 setup. fdc_hw_init() must be provided by the board
2677 source code. It is used to make hardware dependant
2680 - CONFIG_SYS_IMMR: Physical address of the Internal Memory.
2681 DO NOT CHANGE unless you know exactly what you're
2682 doing! (11-4) [MPC8xx/82xx systems only]
2684 - CONFIG_SYS_INIT_RAM_ADDR:
2686 Start address of memory area that can be used for
2687 initial data and stack; please note that this must be
2688 writable memory that is working WITHOUT special
2689 initialization, i. e. you CANNOT use normal RAM which
2690 will become available only after programming the
2691 memory controller and running certain initialization
2694 U-Boot uses the following memory types:
2695 - MPC8xx and MPC8260: IMMR (internal memory of the CPU)
2696 - MPC824X: data cache
2697 - PPC4xx: data cache
2699 - CONFIG_SYS_GBL_DATA_OFFSET:
2701 Offset of the initial data structure in the memory
2702 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually
2703 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial
2704 data is located at the end of the available space
2705 (sometimes written as (CONFIG_SYS_INIT_RAM_SIZE -
2706 CONFIG_SYS_INIT_DATA_SIZE), and the initial stack is just
2707 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR +
2708 CONFIG_SYS_GBL_DATA_OFFSET) downward.
2711 On the MPC824X (or other systems that use the data
2712 cache for initial memory) the address chosen for
2713 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must
2714 point to an otherwise UNUSED address space between
2715 the top of RAM and the start of the PCI space.
2717 - CONFIG_SYS_SIUMCR: SIU Module Configuration (11-6)
2719 - CONFIG_SYS_SYPCR: System Protection Control (11-9)
2721 - CONFIG_SYS_TBSCR: Time Base Status and Control (11-26)
2723 - CONFIG_SYS_PISCR: Periodic Interrupt Status and Control (11-31)
2725 - CONFIG_SYS_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30)
2727 - CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27)
2729 - CONFIG_SYS_OR_TIMING_SDRAM:
2732 - CONFIG_SYS_MAMR_PTA:
2733 periodic timer for refresh
2735 - CONFIG_SYS_DER: Debug Event Register (37-47)
2737 - FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM,
2738 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP,
2739 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM,
2740 CONFIG_SYS_BR1_PRELIM:
2741 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
2743 - SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
2744 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM,
2745 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM:
2746 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
2748 - CONFIG_SYS_MAMR_PTA, CONFIG_SYS_MPTPR_2BK_4K, CONFIG_SYS_MPTPR_1BK_4K, CONFIG_SYS_MPTPR_2BK_8K,
2749 CONFIG_SYS_MPTPR_1BK_8K, CONFIG_SYS_MAMR_8COL, CONFIG_SYS_MAMR_9COL:
2750 Machine Mode Register and Memory Periodic Timer
2751 Prescaler definitions (SDRAM timing)
2753 - CONFIG_SYS_I2C_UCODE_PATCH, CONFIG_SYS_I2C_DPMEM_OFFSET [0x1FC0]:
2754 enable I2C microcode relocation patch (MPC8xx);
2755 define relocation offset in DPRAM [DSP2]
2757 - CONFIG_SYS_SMC_UCODE_PATCH, CONFIG_SYS_SMC_DPMEM_OFFSET [0x1FC0]:
2758 enable SMC microcode relocation patch (MPC8xx);
2759 define relocation offset in DPRAM [SMC1]
2761 - CONFIG_SYS_SPI_UCODE_PATCH, CONFIG_SYS_SPI_DPMEM_OFFSET [0x1FC0]:
2762 enable SPI microcode relocation patch (MPC8xx);
2763 define relocation offset in DPRAM [SCC4]
2765 - CONFIG_SYS_USE_OSCCLK:
2766 Use OSCM clock mode on MBX8xx board. Be careful,
2767 wrong setting might damage your board. Read
2768 doc/README.MBX before setting this variable!
2770 - CONFIG_SYS_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only)
2771 Offset of the bootmode word in DPRAM used by post
2772 (Power On Self Tests). This definition overrides
2773 #define'd default value in commproc.h resp.
2776 - CONFIG_SYS_PCI_SLV_MEM_LOCAL, CONFIG_SYS_PCI_SLV_MEM_BUS, CONFIG_SYS_PICMR0_MASK_ATTRIB,
2777 CONFIG_SYS_PCI_MSTR0_LOCAL, CONFIG_SYS_PCIMSK0_MASK, CONFIG_SYS_PCI_MSTR1_LOCAL,
2778 CONFIG_SYS_PCIMSK1_MASK, CONFIG_SYS_PCI_MSTR_MEM_LOCAL, CONFIG_SYS_PCI_MSTR_MEM_BUS,
2779 CONFIG_SYS_CPU_PCI_MEM_START, CONFIG_SYS_PCI_MSTR_MEM_SIZE, CONFIG_SYS_POCMR0_MASK_ATTRIB,
2780 CONFIG_SYS_PCI_MSTR_MEMIO_LOCAL, CONFIG_SYS_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START,
2781 CONFIG_SYS_PCI_MSTR_MEMIO_SIZE, CONFIG_SYS_POCMR1_MASK_ATTRIB, CONFIG_SYS_PCI_MSTR_IO_LOCAL,
2782 CONFIG_SYS_PCI_MSTR_IO_BUS, CONFIG_SYS_CPU_PCI_IO_START, CONFIG_SYS_PCI_MSTR_IO_SIZE,
2783 CONFIG_SYS_POCMR2_MASK_ATTRIB: (MPC826x only)
2784 Overrides the default PCI memory map in arch/powerpc/cpu/mpc8260/pci.c if set.
2786 - CONFIG_PCI_DISABLE_PCIE:
2787 Disable PCI-Express on systems where it is supported but not
2791 Chip has SRIO or not
2794 Board has SRIO 1 port available
2797 Board has SRIO 2 port available
2799 - CONFIG_SYS_SRIOn_MEM_VIRT:
2800 Virtual Address of SRIO port 'n' memory region
2802 - CONFIG_SYS_SRIOn_MEM_PHYS:
2803 Physical Address of SRIO port 'n' memory region
2805 - CONFIG_SYS_SRIOn_MEM_SIZE:
2806 Size of SRIO port 'n' memory region
2809 Get DDR timing information from an I2C EEPROM. Common
2810 with pluggable memory modules such as SODIMMs
2813 I2C address of the SPD EEPROM
2815 - CONFIG_SYS_SPD_BUS_NUM
2816 If SPD EEPROM is on an I2C bus other than the first
2817 one, specify here. Note that the value must resolve
2818 to something your driver can deal with.
2820 - CONFIG_SYS_83XX_DDR_USES_CS0
2821 Only for 83xx systems. If specified, then DDR should
2822 be configured using CS0 and CS1 instead of CS2 and CS3.
2824 - CONFIG_ETHER_ON_FEC[12]
2825 Define to enable FEC[12] on a 8xx series processor.
2827 - CONFIG_FEC[12]_PHY
2828 Define to the hardcoded PHY address which corresponds
2829 to the given FEC; i. e.
2830 #define CONFIG_FEC1_PHY 4
2831 means that the PHY with address 4 is connected to FEC1
2833 When set to -1, means to probe for first available.
2835 - CONFIG_FEC[12]_PHY_NORXERR
2836 The PHY does not have a RXERR line (RMII only).
2837 (so program the FEC to ignore it).
2840 Enable RMII mode for all FECs.
2841 Note that this is a global option, we can't
2842 have one FEC in standard MII mode and another in RMII mode.
2844 - CONFIG_CRC32_VERIFY
2845 Add a verify option to the crc32 command.
2848 => crc32 -v <address> <count> <crc32>
2850 Where address/count indicate a memory area
2851 and crc32 is the correct crc32 which the
2855 Add the "loopw" memory command. This only takes effect if
2856 the memory commands are activated globally (CONFIG_CMD_MEM).
2859 Add the "mdc" and "mwc" memory commands. These are cyclic
2864 This command will print 4 bytes (10,11,12,13) each 500 ms.
2866 => mwc.l 100 12345678 10
2867 This command will write 12345678 to address 100 all 10 ms.
2869 This only takes effect if the memory commands are activated
2870 globally (CONFIG_CMD_MEM).
2872 - CONFIG_SKIP_LOWLEVEL_INIT
2873 [ARM only] If this variable is defined, then certain
2874 low level initializations (like setting up the memory
2875 controller) are omitted and/or U-Boot does not
2876 relocate itself into RAM.
2878 Normally this variable MUST NOT be defined. The only
2879 exception is when U-Boot is loaded (to RAM) by some
2880 other boot loader or by a debugger which performs
2881 these initializations itself.
2884 Modifies the behaviour of start.S when compiling a loader
2885 that is executed before the actual U-Boot. E.g. when
2886 compiling a NAND SPL.
2888 Building the Software:
2889 ======================
2891 Building U-Boot has been tested in several native build environments
2892 and in many different cross environments. Of course we cannot support
2893 all possibly existing versions of cross development tools in all
2894 (potentially obsolete) versions. In case of tool chain problems we
2895 recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK)
2896 which is extensively used to build and test U-Boot.
2898 If you are not using a native environment, it is assumed that you
2899 have GNU cross compiling tools available in your path. In this case,
2900 you must set the environment variable CROSS_COMPILE in your shell.
2901 Note that no changes to the Makefile or any other source files are
2902 necessary. For example using the ELDK on a 4xx CPU, please enter:
2904 $ CROSS_COMPILE=ppc_4xx-
2905 $ export CROSS_COMPILE
2907 Note: If you wish to generate Windows versions of the utilities in
2908 the tools directory you can use the MinGW toolchain
2909 (http://www.mingw.org). Set your HOST tools to the MinGW
2910 toolchain and execute 'make tools'. For example:
2912 $ make HOSTCC=i586-mingw32msvc-gcc HOSTSTRIP=i586-mingw32msvc-strip tools
2914 Binaries such as tools/mkimage.exe will be created which can
2915 be executed on computers running Windows.
2917 U-Boot is intended to be simple to build. After installing the
2918 sources you must configure U-Boot for one specific board type. This
2923 where "NAME_config" is the name of one of the existing configu-
2924 rations; see the main Makefile for supported names.
2926 Note: for some board special configuration names may exist; check if
2927 additional information is available from the board vendor; for
2928 instance, the TQM823L systems are available without (standard)
2929 or with LCD support. You can select such additional "features"
2930 when choosing the configuration, i. e.
2933 - will configure for a plain TQM823L, i. e. no LCD support
2935 make TQM823L_LCD_config
2936 - will configure for a TQM823L with U-Boot console on LCD
2941 Finally, type "make all", and you should get some working U-Boot
2942 images ready for download to / installation on your system:
2944 - "u-boot.bin" is a raw binary image
2945 - "u-boot" is an image in ELF binary format
2946 - "u-boot.srec" is in Motorola S-Record format
2948 By default the build is performed locally and the objects are saved
2949 in the source directory. One of the two methods can be used to change
2950 this behavior and build U-Boot to some external directory:
2952 1. Add O= to the make command line invocations:
2954 make O=/tmp/build distclean
2955 make O=/tmp/build NAME_config
2956 make O=/tmp/build all
2958 2. Set environment variable BUILD_DIR to point to the desired location:
2960 export BUILD_DIR=/tmp/build
2965 Note that the command line "O=" setting overrides the BUILD_DIR environment
2969 Please be aware that the Makefiles assume you are using GNU make, so
2970 for instance on NetBSD you might need to use "gmake" instead of
2974 If the system board that you have is not listed, then you will need
2975 to port U-Boot to your hardware platform. To do this, follow these
2978 1. Add a new configuration option for your board to the toplevel
2979 "Makefile" and to the "MAKEALL" script, using the existing
2980 entries as examples. Note that here and at many other places
2981 boards and other names are listed in alphabetical sort order. Please
2983 2. Create a new directory to hold your board specific code. Add any
2984 files you need. In your board directory, you will need at least
2985 the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds".
2986 3. Create a new configuration file "include/configs/<board>.h" for
2988 3. If you're porting U-Boot to a new CPU, then also create a new
2989 directory to hold your CPU specific code. Add any files you need.
2990 4. Run "make <board>_config" with your new name.
2991 5. Type "make", and you should get a working "u-boot.srec" file
2992 to be installed on your target system.
2993 6. Debug and solve any problems that might arise.
2994 [Of course, this last step is much harder than it sounds.]
2997 Testing of U-Boot Modifications, Ports to New Hardware, etc.:
2998 ==============================================================
3000 If you have modified U-Boot sources (for instance added a new board
3001 or support for new devices, a new CPU, etc.) you are expected to
3002 provide feedback to the other developers. The feedback normally takes
3003 the form of a "patch", i. e. a context diff against a certain (latest
3004 official or latest in the git repository) version of U-Boot sources.
3006 But before you submit such a patch, please verify that your modifi-
3007 cation did not break existing code. At least make sure that *ALL* of
3008 the supported boards compile WITHOUT ANY compiler warnings. To do so,
3009 just run the "MAKEALL" script, which will configure and build U-Boot
3010 for ALL supported system. Be warned, this will take a while. You can
3011 select which (cross) compiler to use by passing a `CROSS_COMPILE'
3012 environment variable to the script, i. e. to use the ELDK cross tools
3015 CROSS_COMPILE=ppc_8xx- MAKEALL
3017 or to build on a native PowerPC system you can type
3019 CROSS_COMPILE=' ' MAKEALL
3021 When using the MAKEALL script, the default behaviour is to build
3022 U-Boot in the source directory. This location can be changed by
3023 setting the BUILD_DIR environment variable. Also, for each target
3024 built, the MAKEALL script saves two log files (<target>.ERR and
3025 <target>.MAKEALL) in the <source dir>/LOG directory. This default
3026 location can be changed by setting the MAKEALL_LOGDIR environment
3027 variable. For example:
3029 export BUILD_DIR=/tmp/build
3030 export MAKEALL_LOGDIR=/tmp/log
3031 CROSS_COMPILE=ppc_8xx- MAKEALL
3033 With the above settings build objects are saved in the /tmp/build,
3034 log files are saved in the /tmp/log and the source tree remains clean
3035 during the whole build process.
3038 See also "U-Boot Porting Guide" below.
3041 Monitor Commands - Overview:
3042 ============================
3044 go - start application at address 'addr'
3045 run - run commands in an environment variable
3046 bootm - boot application image from memory
3047 bootp - boot image via network using BootP/TFTP protocol
3048 tftpboot- boot image via network using TFTP protocol
3049 and env variables "ipaddr" and "serverip"
3050 (and eventually "gatewayip")
3051 rarpboot- boot image via network using RARP/TFTP protocol
3052 diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
3053 loads - load S-Record file over serial line
3054 loadb - load binary file over serial line (kermit mode)
3056 mm - memory modify (auto-incrementing)
3057 nm - memory modify (constant address)
3058 mw - memory write (fill)
3060 cmp - memory compare
3061 crc32 - checksum calculation
3062 i2c - I2C sub-system
3063 sspi - SPI utility commands
3064 base - print or set address offset
3065 printenv- print environment variables
3066 setenv - set environment variables
3067 saveenv - save environment variables to persistent storage
3068 protect - enable or disable FLASH write protection
3069 erase - erase FLASH memory
3070 flinfo - print FLASH memory information
3071 bdinfo - print Board Info structure
3072 iminfo - print header information for application image
3073 coninfo - print console devices and informations
3074 ide - IDE sub-system
3075 loop - infinite loop on address range
3076 loopw - infinite write loop on address range
3077 mtest - simple RAM test
3078 icache - enable or disable instruction cache
3079 dcache - enable or disable data cache
3080 reset - Perform RESET of the CPU
3081 echo - echo args to console
3082 version - print monitor version
3083 help - print online help
3084 ? - alias for 'help'
3087 Monitor Commands - Detailed Description:
3088 ========================================
3092 For now: just type "help <command>".
3095 Environment Variables:
3096 ======================
3098 U-Boot supports user configuration using Environment Variables which
3099 can be made persistent by saving to Flash memory.
3101 Environment Variables are set using "setenv", printed using
3102 "printenv", and saved to Flash using "saveenv". Using "setenv"
3103 without a value can be used to delete a variable from the
3104 environment. As long as you don't save the environment you are
3105 working with an in-memory copy. In case the Flash area containing the
3106 environment is erased by accident, a default environment is provided.
3108 Some configuration options can be set using Environment Variables.
3110 List of environment variables (most likely not complete):
3112 baudrate - see CONFIG_BAUDRATE
3114 bootdelay - see CONFIG_BOOTDELAY
3116 bootcmd - see CONFIG_BOOTCOMMAND
3118 bootargs - Boot arguments when booting an RTOS image
3120 bootfile - Name of the image to load with TFTP
3122 bootm_low - Memory range available for image processing in the bootm
3123 command can be restricted. This variable is given as
3124 a hexadecimal number and defines lowest address allowed
3125 for use by the bootm command. See also "bootm_size"
3126 environment variable. Address defined by "bootm_low" is
3127 also the base of the initial memory mapping for the Linux
3128 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ.
3130 bootm_size - Memory range available for image processing in the bootm
3131 command can be restricted. This variable is given as
3132 a hexadecimal number and defines the size of the region
3133 allowed for use by the bootm command. See also "bootm_low"
3134 environment variable.
3136 updatefile - Location of the software update file on a TFTP server, used
3137 by the automatic software update feature. Please refer to
3138 documentation in doc/README.update for more details.
3140 autoload - if set to "no" (any string beginning with 'n'),
3141 "bootp" will just load perform a lookup of the
3142 configuration from the BOOTP server, but not try to
3143 load any image using TFTP
3145 autostart - if set to "yes", an image loaded using the "bootp",
3146 "rarpboot", "tftpboot" or "diskboot" commands will
3147 be automatically started (by internally calling
3150 If set to "no", a standalone image passed to the
3151 "bootm" command will be copied to the load address
3152 (and eventually uncompressed), but NOT be started.
3153 This can be used to load and uncompress arbitrary
3156 i2cfast - (PPC405GP|PPC405EP only)
3157 if set to 'y' configures Linux I2C driver for fast
3158 mode (400kHZ). This environment variable is used in
3159 initialization code. So, for changes to be effective
3160 it must be saved and board must be reset.
3162 initrd_high - restrict positioning of initrd images:
3163 If this variable is not set, initrd images will be
3164 copied to the highest possible address in RAM; this
3165 is usually what you want since it allows for
3166 maximum initrd size. If for some reason you want to
3167 make sure that the initrd image is loaded below the
3168 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment
3169 variable to a value of "no" or "off" or "0".
3170 Alternatively, you can set it to a maximum upper
3171 address to use (U-Boot will still check that it
3172 does not overwrite the U-Boot stack and data).
3174 For instance, when you have a system with 16 MB
3175 RAM, and want to reserve 4 MB from use by Linux,
3176 you can do this by adding "mem=12M" to the value of
3177 the "bootargs" variable. However, now you must make
3178 sure that the initrd image is placed in the first
3179 12 MB as well - this can be done with
3181 setenv initrd_high 00c00000
3183 If you set initrd_high to 0xFFFFFFFF, this is an
3184 indication to U-Boot that all addresses are legal
3185 for the Linux kernel, including addresses in flash
3186 memory. In this case U-Boot will NOT COPY the
3187 ramdisk at all. This may be useful to reduce the
3188 boot time on your system, but requires that this
3189 feature is supported by your Linux kernel.
3191 ipaddr - IP address; needed for tftpboot command
3193 loadaddr - Default load address for commands like "bootp",
3194 "rarpboot", "tftpboot", "loadb" or "diskboot"
3196 loads_echo - see CONFIG_LOADS_ECHO
3198 serverip - TFTP server IP address; needed for tftpboot command
3200 bootretry - see CONFIG_BOOT_RETRY_TIME
3202 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
3204 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
3206 ethprime - When CONFIG_NET_MULTI is enabled controls which
3207 interface is used first.
3209 ethact - When CONFIG_NET_MULTI is enabled controls which
3210 interface is currently active. For example you
3211 can do the following
3213 => setenv ethact FEC
3214 => ping 192.168.0.1 # traffic sent on FEC
3215 => setenv ethact SCC
3216 => ping 10.0.0.1 # traffic sent on SCC
3218 ethrotate - When set to "no" U-Boot does not go through all
3219 available network interfaces.
3220 It just stays at the currently selected interface.
3222 netretry - When set to "no" each network operation will
3223 either succeed or fail without retrying.
3224 When set to "once" the network operation will
3225 fail when all the available network interfaces
3226 are tried once without success.
3227 Useful on scripts which control the retry operation
3230 npe_ucode - set load address for the NPE microcode
3232 tftpsrcport - If this is set, the value is used for TFTP's
3235 tftpdstport - If this is set, the value is used for TFTP's UDP
3236 destination port instead of the Well Know Port 69.
3238 tftpblocksize - Block size to use for TFTP transfers; if not set,
3239 we use the TFTP server's default block size
3241 tftptimeout - Retransmission timeout for TFTP packets (in milli-
3242 seconds, minimum value is 1000 = 1 second). Defines
3243 when a packet is considered to be lost so it has to
3244 be retransmitted. The default is 5000 = 5 seconds.
3245 Lowering this value may make downloads succeed
3246 faster in networks with high packet loss rates or
3247 with unreliable TFTP servers.
3249 vlan - When set to a value < 4095 the traffic over
3250 Ethernet is encapsulated/received over 802.1q
3253 The following environment variables may be used and automatically
3254 updated by the network boot commands ("bootp" and "rarpboot"),
3255 depending the information provided by your boot server:
3257 bootfile - see above
3258 dnsip - IP address of your Domain Name Server
3259 dnsip2 - IP address of your secondary Domain Name Server
3260 gatewayip - IP address of the Gateway (Router) to use
3261 hostname - Target hostname
3263 netmask - Subnet Mask
3264 rootpath - Pathname of the root filesystem on the NFS server
3265 serverip - see above
3268 There are two special Environment Variables:
3270 serial# - contains hardware identification information such
3271 as type string and/or serial number
3272 ethaddr - Ethernet address
3274 These variables can be set only once (usually during manufacturing of
3275 the board). U-Boot refuses to delete or overwrite these variables
3276 once they have been set once.
3279 Further special Environment Variables:
3281 ver - Contains the U-Boot version string as printed
3282 with the "version" command. This variable is
3283 readonly (see CONFIG_VERSION_VARIABLE).
3286 Please note that changes to some configuration parameters may take
3287 only effect after the next boot (yes, that's just like Windoze :-).
3290 Command Line Parsing:
3291 =====================
3293 There are two different command line parsers available with U-Boot:
3294 the old "simple" one, and the much more powerful "hush" shell:
3296 Old, simple command line parser:
3297 --------------------------------
3299 - supports environment variables (through setenv / saveenv commands)
3300 - several commands on one line, separated by ';'
3301 - variable substitution using "... ${name} ..." syntax
3302 - special characters ('$', ';') can be escaped by prefixing with '\',
3304 setenv bootcmd bootm \${address}
3305 - You can also escape text by enclosing in single apostrophes, for example:
3306 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
3311 - similar to Bourne shell, with control structures like
3312 if...then...else...fi, for...do...done; while...do...done,
3313 until...do...done, ...
3314 - supports environment ("global") variables (through setenv / saveenv
3315 commands) and local shell variables (through standard shell syntax
3316 "name=value"); only environment variables can be used with "run"
3322 (1) If a command line (or an environment variable executed by a "run"
3323 command) contains several commands separated by semicolon, and
3324 one of these commands fails, then the remaining commands will be
3327 (2) If you execute several variables with one call to run (i. e.
3328 calling run with a list of variables as arguments), any failing
3329 command will cause "run" to terminate, i. e. the remaining
3330 variables are not executed.
3332 Note for Redundant Ethernet Interfaces:
3333 =======================================
3335 Some boards come with redundant Ethernet interfaces; U-Boot supports
3336 such configurations and is capable of automatic selection of a
3337 "working" interface when needed. MAC assignment works as follows:
3339 Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
3340 MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
3341 "eth1addr" (=>eth1), "eth2addr", ...
3343 If the network interface stores some valid MAC address (for instance
3344 in SROM), this is used as default address if there is NO correspon-
3345 ding setting in the environment; if the corresponding environment
3346 variable is set, this overrides the settings in the card; that means:
3348 o If the SROM has a valid MAC address, and there is no address in the
3349 environment, the SROM's address is used.
3351 o If there is no valid address in the SROM, and a definition in the
3352 environment exists, then the value from the environment variable is
3355 o If both the SROM and the environment contain a MAC address, and
3356 both addresses are the same, this MAC address is used.
3358 o If both the SROM and the environment contain a MAC address, and the
3359 addresses differ, the value from the environment is used and a
3362 o If neither SROM nor the environment contain a MAC address, an error
3365 If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses
3366 will be programmed into hardware as part of the initialization process. This
3367 may be skipped by setting the appropriate 'ethmacskip' environment variable.
3368 The naming convention is as follows:
3369 "ethmacskip" (=>eth0), "eth1macskip" (=>eth1) etc.
3374 U-Boot is capable of booting (and performing other auxiliary operations on)
3375 images in two formats:
3377 New uImage format (FIT)
3378 -----------------------
3380 Flexible and powerful format based on Flattened Image Tree -- FIT (similar
3381 to Flattened Device Tree). It allows the use of images with multiple
3382 components (several kernels, ramdisks, etc.), with contents protected by
3383 SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory.
3389 Old image format is based on binary files which can be basically anything,
3390 preceded by a special header; see the definitions in include/image.h for
3391 details; basically, the header defines the following image properties:
3393 * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
3394 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
3395 LynxOS, pSOS, QNX, RTEMS, INTEGRITY;
3396 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS,
3398 * Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86,
3399 IA64, MIPS, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
3400 Currently supported: ARM, AVR32, Intel x86, MIPS, Nios II, PowerPC).
3401 * Compression Type (uncompressed, gzip, bzip2)
3407 The header is marked by a special Magic Number, and both the header
3408 and the data portions of the image are secured against corruption by
3415 Although U-Boot should support any OS or standalone application
3416 easily, the main focus has always been on Linux during the design of
3419 U-Boot includes many features that so far have been part of some
3420 special "boot loader" code within the Linux kernel. Also, any
3421 "initrd" images to be used are no longer part of one big Linux image;
3422 instead, kernel and "initrd" are separate images. This implementation
3423 serves several purposes:
3425 - the same features can be used for other OS or standalone
3426 applications (for instance: using compressed images to reduce the
3427 Flash memory footprint)
3429 - it becomes much easier to port new Linux kernel versions because
3430 lots of low-level, hardware dependent stuff are done by U-Boot
3432 - the same Linux kernel image can now be used with different "initrd"
3433 images; of course this also means that different kernel images can
3434 be run with the same "initrd". This makes testing easier (you don't
3435 have to build a new "zImage.initrd" Linux image when you just
3436 change a file in your "initrd"). Also, a field-upgrade of the
3437 software is easier now.
3443 Porting Linux to U-Boot based systems:
3444 ---------------------------------------
3446 U-Boot cannot save you from doing all the necessary modifications to
3447 configure the Linux device drivers for use with your target hardware
3448 (no, we don't intend to provide a full virtual machine interface to
3451 But now you can ignore ALL boot loader code (in arch/powerpc/mbxboot).
3453 Just make sure your machine specific header file (for instance
3454 include/asm-ppc/tqm8xx.h) includes the same definition of the Board
3455 Information structure as we define in include/asm-<arch>/u-boot.h,
3456 and make sure that your definition of IMAP_ADDR uses the same value
3457 as your U-Boot configuration in CONFIG_SYS_IMMR.
3460 Configuring the Linux kernel:
3461 -----------------------------
3463 No specific requirements for U-Boot. Make sure you have some root
3464 device (initial ramdisk, NFS) for your target system.
3467 Building a Linux Image:
3468 -----------------------
3470 With U-Boot, "normal" build targets like "zImage" or "bzImage" are
3471 not used. If you use recent kernel source, a new build target
3472 "uImage" will exist which automatically builds an image usable by
3473 U-Boot. Most older kernels also have support for a "pImage" target,
3474 which was introduced for our predecessor project PPCBoot and uses a
3475 100% compatible format.
3484 The "uImage" build target uses a special tool (in 'tools/mkimage') to
3485 encapsulate a compressed Linux kernel image with header information,
3486 CRC32 checksum etc. for use with U-Boot. This is what we are doing:
3488 * build a standard "vmlinux" kernel image (in ELF binary format):
3490 * convert the kernel into a raw binary image:
3492 ${CROSS_COMPILE}-objcopy -O binary \
3493 -R .note -R .comment \
3494 -S vmlinux linux.bin
3496 * compress the binary image:
3500 * package compressed binary image for U-Boot:
3502 mkimage -A ppc -O linux -T kernel -C gzip \
3503 -a 0 -e 0 -n "Linux Kernel Image" \
3504 -d linux.bin.gz uImage
3507 The "mkimage" tool can also be used to create ramdisk images for use
3508 with U-Boot, either separated from the Linux kernel image, or
3509 combined into one file. "mkimage" encapsulates the images with a 64
3510 byte header containing information about target architecture,
3511 operating system, image type, compression method, entry points, time
3512 stamp, CRC32 checksums, etc.
3514 "mkimage" can be called in two ways: to verify existing images and
3515 print the header information, or to build new images.
3517 In the first form (with "-l" option) mkimage lists the information
3518 contained in the header of an existing U-Boot image; this includes
3519 checksum verification:
3521 tools/mkimage -l image
3522 -l ==> list image header information
3524 The second form (with "-d" option) is used to build a U-Boot image
3525 from a "data file" which is used as image payload:
3527 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
3528 -n name -d data_file image
3529 -A ==> set architecture to 'arch'
3530 -O ==> set operating system to 'os'
3531 -T ==> set image type to 'type'
3532 -C ==> set compression type 'comp'
3533 -a ==> set load address to 'addr' (hex)
3534 -e ==> set entry point to 'ep' (hex)
3535 -n ==> set image name to 'name'
3536 -d ==> use image data from 'datafile'
3538 Right now, all Linux kernels for PowerPC systems use the same load
3539 address (0x00000000), but the entry point address depends on the
3542 - 2.2.x kernels have the entry point at 0x0000000C,
3543 - 2.3.x and later kernels have the entry point at 0x00000000.
3545 So a typical call to build a U-Boot image would read:
3547 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
3548 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
3549 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz \
3550 > examples/uImage.TQM850L
3551 Image Name: 2.4.4 kernel for TQM850L
3552 Created: Wed Jul 19 02:34:59 2000
3553 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3554 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
3555 Load Address: 0x00000000
3556 Entry Point: 0x00000000
3558 To verify the contents of the image (or check for corruption):
3560 -> tools/mkimage -l examples/uImage.TQM850L
3561 Image Name: 2.4.4 kernel for TQM850L
3562 Created: Wed Jul 19 02:34:59 2000
3563 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3564 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
3565 Load Address: 0x00000000
3566 Entry Point: 0x00000000
3568 NOTE: for embedded systems where boot time is critical you can trade
3569 speed for memory and install an UNCOMPRESSED image instead: this
3570 needs more space in Flash, but boots much faster since it does not
3571 need to be uncompressed:
3573 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz
3574 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
3575 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
3576 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux \
3577 > examples/uImage.TQM850L-uncompressed
3578 Image Name: 2.4.4 kernel for TQM850L
3579 Created: Wed Jul 19 02:34:59 2000
3580 Image Type: PowerPC Linux Kernel Image (uncompressed)
3581 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
3582 Load Address: 0x00000000
3583 Entry Point: 0x00000000
3586 Similar you can build U-Boot images from a 'ramdisk.image.gz' file
3587 when your kernel is intended to use an initial ramdisk:
3589 -> tools/mkimage -n 'Simple Ramdisk Image' \
3590 > -A ppc -O linux -T ramdisk -C gzip \
3591 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
3592 Image Name: Simple Ramdisk Image
3593 Created: Wed Jan 12 14:01:50 2000
3594 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
3595 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
3596 Load Address: 0x00000000
3597 Entry Point: 0x00000000
3600 Installing a Linux Image:
3601 -------------------------
3603 To downloading a U-Boot image over the serial (console) interface,
3604 you must convert the image to S-Record format:
3606 objcopy -I binary -O srec examples/image examples/image.srec
3608 The 'objcopy' does not understand the information in the U-Boot
3609 image header, so the resulting S-Record file will be relative to
3610 address 0x00000000. To load it to a given address, you need to
3611 specify the target address as 'offset' parameter with the 'loads'
3614 Example: install the image to address 0x40100000 (which on the
3615 TQM8xxL is in the first Flash bank):
3617 => erase 40100000 401FFFFF
3623 ## Ready for S-Record download ...
3624 ~>examples/image.srec
3625 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
3627 15989 15990 15991 15992
3628 [file transfer complete]
3630 ## Start Addr = 0x00000000
3633 You can check the success of the download using the 'iminfo' command;
3634 this includes a checksum verification so you can be sure no data
3635 corruption happened:
3639 ## Checking Image at 40100000 ...
3640 Image Name: 2.2.13 for initrd on TQM850L
3641 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3642 Data Size: 335725 Bytes = 327 kB = 0 MB
3643 Load Address: 00000000
3644 Entry Point: 0000000c
3645 Verifying Checksum ... OK
3651 The "bootm" command is used to boot an application that is stored in
3652 memory (RAM or Flash). In case of a Linux kernel image, the contents
3653 of the "bootargs" environment variable is passed to the kernel as
3654 parameters. You can check and modify this variable using the
3655 "printenv" and "setenv" commands:
3658 => printenv bootargs
3659 bootargs=root=/dev/ram
3661 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
3663 => printenv bootargs
3664 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
3667 ## Booting Linux kernel at 40020000 ...
3668 Image Name: 2.2.13 for NFS on TQM850L
3669 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3670 Data Size: 381681 Bytes = 372 kB = 0 MB
3671 Load Address: 00000000
3672 Entry Point: 0000000c
3673 Verifying Checksum ... OK
3674 Uncompressing Kernel Image ... OK
3675 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
3676 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
3677 time_init: decrementer frequency = 187500000/60
3678 Calibrating delay loop... 49.77 BogoMIPS
3679 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
3682 If you want to boot a Linux kernel with initial RAM disk, you pass
3683 the memory addresses of both the kernel and the initrd image (PPBCOOT
3684 format!) to the "bootm" command:
3686 => imi 40100000 40200000
3688 ## Checking Image at 40100000 ...
3689 Image Name: 2.2.13 for initrd on TQM850L
3690 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3691 Data Size: 335725 Bytes = 327 kB = 0 MB
3692 Load Address: 00000000
3693 Entry Point: 0000000c
3694 Verifying Checksum ... OK
3696 ## Checking Image at 40200000 ...
3697 Image Name: Simple Ramdisk Image
3698 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
3699 Data Size: 566530 Bytes = 553 kB = 0 MB
3700 Load Address: 00000000
3701 Entry Point: 00000000
3702 Verifying Checksum ... OK
3704 => bootm 40100000 40200000
3705 ## Booting Linux kernel at 40100000 ...
3706 Image Name: 2.2.13 for initrd on TQM850L
3707 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3708 Data Size: 335725 Bytes = 327 kB = 0 MB
3709 Load Address: 00000000
3710 Entry Point: 0000000c
3711 Verifying Checksum ... OK
3712 Uncompressing Kernel Image ... OK
3713 ## Loading RAMDisk Image at 40200000 ...
3714 Image Name: Simple Ramdisk Image
3715 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
3716 Data Size: 566530 Bytes = 553 kB = 0 MB
3717 Load Address: 00000000
3718 Entry Point: 00000000
3719 Verifying Checksum ... OK
3720 Loading Ramdisk ... OK
3721 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
3722 Boot arguments: root=/dev/ram
3723 time_init: decrementer frequency = 187500000/60
3724 Calibrating delay loop... 49.77 BogoMIPS
3726 RAMDISK: Compressed image found at block 0
3727 VFS: Mounted root (ext2 filesystem).
3731 Boot Linux and pass a flat device tree:
3734 First, U-Boot must be compiled with the appropriate defines. See the section
3735 titled "Linux Kernel Interface" above for a more in depth explanation. The
3736 following is an example of how to start a kernel and pass an updated
3742 oft=oftrees/mpc8540ads.dtb
3743 => tftp $oftaddr $oft
3744 Speed: 1000, full duplex
3746 TFTP from server 192.168.1.1; our IP address is 192.168.1.101
3747 Filename 'oftrees/mpc8540ads.dtb'.
3748 Load address: 0x300000
3751 Bytes transferred = 4106 (100a hex)
3752 => tftp $loadaddr $bootfile
3753 Speed: 1000, full duplex
3755 TFTP from server 192.168.1.1; our IP address is 192.168.1.2
3757 Load address: 0x200000
3758 Loading:############
3760 Bytes transferred = 1029407 (fb51f hex)
3765 => bootm $loadaddr - $oftaddr
3766 ## Booting image at 00200000 ...
3767 Image Name: Linux-2.6.17-dirty
3768 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3769 Data Size: 1029343 Bytes = 1005.2 kB
3770 Load Address: 00000000
3771 Entry Point: 00000000
3772 Verifying Checksum ... OK
3773 Uncompressing Kernel Image ... OK
3774 Booting using flat device tree at 0x300000
3775 Using MPC85xx ADS machine description
3776 Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb
3780 More About U-Boot Image Types:
3781 ------------------------------
3783 U-Boot supports the following image types:
3785 "Standalone Programs" are directly runnable in the environment
3786 provided by U-Boot; it is expected that (if they behave
3787 well) you can continue to work in U-Boot after return from
3788 the Standalone Program.
3789 "OS Kernel Images" are usually images of some Embedded OS which
3790 will take over control completely. Usually these programs
3791 will install their own set of exception handlers, device
3792 drivers, set up the MMU, etc. - this means, that you cannot
3793 expect to re-enter U-Boot except by resetting the CPU.
3794 "RAMDisk Images" are more or less just data blocks, and their
3795 parameters (address, size) are passed to an OS kernel that is
3797 "Multi-File Images" contain several images, typically an OS
3798 (Linux) kernel image and one or more data images like
3799 RAMDisks. This construct is useful for instance when you want
3800 to boot over the network using BOOTP etc., where the boot
3801 server provides just a single image file, but you want to get
3802 for instance an OS kernel and a RAMDisk image.
3804 "Multi-File Images" start with a list of image sizes, each
3805 image size (in bytes) specified by an "uint32_t" in network
3806 byte order. This list is terminated by an "(uint32_t)0".
3807 Immediately after the terminating 0 follow the images, one by
3808 one, all aligned on "uint32_t" boundaries (size rounded up to
3809 a multiple of 4 bytes).
3811 "Firmware Images" are binary images containing firmware (like
3812 U-Boot or FPGA images) which usually will be programmed to
3815 "Script files" are command sequences that will be executed by
3816 U-Boot's command interpreter; this feature is especially
3817 useful when you configure U-Boot to use a real shell (hush)
3818 as command interpreter.
3824 One of the features of U-Boot is that you can dynamically load and
3825 run "standalone" applications, which can use some resources of
3826 U-Boot like console I/O functions or interrupt services.
3828 Two simple examples are included with the sources:
3833 'examples/hello_world.c' contains a small "Hello World" Demo
3834 application; it is automatically compiled when you build U-Boot.
3835 It's configured to run at address 0x00040004, so you can play with it
3839 ## Ready for S-Record download ...
3840 ~>examples/hello_world.srec
3841 1 2 3 4 5 6 7 8 9 10 11 ...
3842 [file transfer complete]
3844 ## Start Addr = 0x00040004
3846 => go 40004 Hello World! This is a test.
3847 ## Starting application at 0x00040004 ...
3858 Hit any key to exit ...
3860 ## Application terminated, rc = 0x0
3862 Another example, which demonstrates how to register a CPM interrupt
3863 handler with the U-Boot code, can be found in 'examples/timer.c'.
3864 Here, a CPM timer is set up to generate an interrupt every second.
3865 The interrupt service routine is trivial, just printing a '.'
3866 character, but this is just a demo program. The application can be
3867 controlled by the following keys:
3869 ? - print current values og the CPM Timer registers
3870 b - enable interrupts and start timer
3871 e - stop timer and disable interrupts
3872 q - quit application
3875 ## Ready for S-Record download ...
3876 ~>examples/timer.srec
3877 1 2 3 4 5 6 7 8 9 10 11 ...
3878 [file transfer complete]
3880 ## Start Addr = 0x00040004
3883 ## Starting application at 0x00040004 ...
3886 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
3889 [q, b, e, ?] Set interval 1000000 us
3892 [q, b, e, ?] ........
3893 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
3896 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
3899 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
3902 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
3904 [q, b, e, ?] ...Stopping timer
3906 [q, b, e, ?] ## Application terminated, rc = 0x0
3912 Over time, many people have reported problems when trying to use the
3913 "minicom" terminal emulation program for serial download. I (wd)
3914 consider minicom to be broken, and recommend not to use it. Under
3915 Unix, I recommend to use C-Kermit for general purpose use (and
3916 especially for kermit binary protocol download ("loadb" command), and
3917 use "cu" for S-Record download ("loads" command).
3919 Nevertheless, if you absolutely want to use it try adding this
3920 configuration to your "File transfer protocols" section:
3922 Name Program Name U/D FullScr IO-Red. Multi
3923 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
3924 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
3930 Starting at version 0.9.2, U-Boot supports NetBSD both as host
3931 (build U-Boot) and target system (boots NetBSD/mpc8xx).
3933 Building requires a cross environment; it is known to work on
3934 NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
3935 need gmake since the Makefiles are not compatible with BSD make).
3936 Note that the cross-powerpc package does not install include files;
3937 attempting to build U-Boot will fail because <machine/ansi.h> is
3938 missing. This file has to be installed and patched manually:
3940 # cd /usr/pkg/cross/powerpc-netbsd/include
3942 # ln -s powerpc machine
3943 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
3944 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
3946 Native builds *don't* work due to incompatibilities between native
3947 and U-Boot include files.
3949 Booting assumes that (the first part of) the image booted is a
3950 stage-2 loader which in turn loads and then invokes the kernel
3951 proper. Loader sources will eventually appear in the NetBSD source
3952 tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
3953 meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz
3956 Implementation Internals:
3957 =========================
3959 The following is not intended to be a complete description of every
3960 implementation detail. However, it should help to understand the
3961 inner workings of U-Boot and make it easier to port it to custom
3965 Initial Stack, Global Data:
3966 ---------------------------
3968 The implementation of U-Boot is complicated by the fact that U-Boot
3969 starts running out of ROM (flash memory), usually without access to
3970 system RAM (because the memory controller is not initialized yet).
3971 This means that we don't have writable Data or BSS segments, and BSS
3972 is not initialized as zero. To be able to get a C environment working
3973 at all, we have to allocate at least a minimal stack. Implementation
3974 options for this are defined and restricted by the CPU used: Some CPU
3975 models provide on-chip memory (like the IMMR area on MPC8xx and
3976 MPC826x processors), on others (parts of) the data cache can be
3977 locked as (mis-) used as memory, etc.
3979 Chris Hallinan posted a good summary of these issues to the
3980 U-Boot mailing list:
3982 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
3983 From: "Chris Hallinan" <clh@net1plus.com>
3984 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
3987 Correct me if I'm wrong, folks, but the way I understand it
3988 is this: Using DCACHE as initial RAM for Stack, etc, does not
3989 require any physical RAM backing up the cache. The cleverness
3990 is that the cache is being used as a temporary supply of
3991 necessary storage before the SDRAM controller is setup. It's
3992 beyond the scope of this list to explain the details, but you
3993 can see how this works by studying the cache architecture and
3994 operation in the architecture and processor-specific manuals.
3996 OCM is On Chip Memory, which I believe the 405GP has 4K. It
3997 is another option for the system designer to use as an
3998 initial stack/RAM area prior to SDRAM being available. Either
3999 option should work for you. Using CS 4 should be fine if your
4000 board designers haven't used it for something that would
4001 cause you grief during the initial boot! It is frequently not
4004 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere
4005 with your processor/board/system design. The default value
4006 you will find in any recent u-boot distribution in
4007 walnut.h should work for you. I'd set it to a value larger
4008 than your SDRAM module. If you have a 64MB SDRAM module, set
4009 it above 400_0000. Just make sure your board has no resources
4010 that are supposed to respond to that address! That code in
4011 start.S has been around a while and should work as is when
4012 you get the config right.
4017 It is essential to remember this, since it has some impact on the C
4018 code for the initialization procedures:
4020 * Initialized global data (data segment) is read-only. Do not attempt
4023 * Do not use any uninitialized global data (or implicitely initialized
4024 as zero data - BSS segment) at all - this is undefined, initiali-
4025 zation is performed later (when relocating to RAM).
4027 * Stack space is very limited. Avoid big data buffers or things like
4030 Having only the stack as writable memory limits means we cannot use
4031 normal global data to share information beween the code. But it
4032 turned out that the implementation of U-Boot can be greatly
4033 simplified by making a global data structure (gd_t) available to all
4034 functions. We could pass a pointer to this data as argument to _all_
4035 functions, but this would bloat the code. Instead we use a feature of
4036 the GCC compiler (Global Register Variables) to share the data: we
4037 place a pointer (gd) to the global data into a register which we
4038 reserve for this purpose.
4040 When choosing a register for such a purpose we are restricted by the
4041 relevant (E)ABI specifications for the current architecture, and by
4042 GCC's implementation.
4044 For PowerPC, the following registers have specific use:
4046 R2: reserved for system use
4047 R3-R4: parameter passing and return values
4048 R5-R10: parameter passing
4049 R13: small data area pointer
4053 (U-Boot also uses R12 as internal GOT pointer. r12
4054 is a volatile register so r12 needs to be reset when
4055 going back and forth between asm and C)
4057 ==> U-Boot will use R2 to hold a pointer to the global data
4059 Note: on PPC, we could use a static initializer (since the
4060 address of the global data structure is known at compile time),
4061 but it turned out that reserving a register results in somewhat
4062 smaller code - although the code savings are not that big (on
4063 average for all boards 752 bytes for the whole U-Boot image,
4064 624 text + 127 data).
4066 On Blackfin, the normal C ABI (except for P3) is followed as documented here:
4067 http://docs.blackfin.uclinux.org/doku.php?id=application_binary_interface
4069 ==> U-Boot will use P3 to hold a pointer to the global data
4071 On ARM, the following registers are used:
4073 R0: function argument word/integer result
4074 R1-R3: function argument word
4076 R10: stack limit (used only if stack checking if enabled)
4077 R11: argument (frame) pointer
4078 R12: temporary workspace
4081 R15: program counter
4083 ==> U-Boot will use R8 to hold a pointer to the global data
4085 On Nios II, the ABI is documented here:
4086 http://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf
4088 ==> U-Boot will use gp to hold a pointer to the global data
4090 Note: on Nios II, we give "-G0" option to gcc and don't use gp
4091 to access small data sections, so gp is free.
4093 NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope,
4094 or current versions of GCC may "optimize" the code too much.
4099 U-Boot runs in system state and uses physical addresses, i.e. the
4100 MMU is not used either for address mapping nor for memory protection.
4102 The available memory is mapped to fixed addresses using the memory
4103 controller. In this process, a contiguous block is formed for each
4104 memory type (Flash, SDRAM, SRAM), even when it consists of several
4105 physical memory banks.
4107 U-Boot is installed in the first 128 kB of the first Flash bank (on
4108 TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
4109 booting and sizing and initializing DRAM, the code relocates itself
4110 to the upper end of DRAM. Immediately below the U-Boot code some
4111 memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN
4112 configuration setting]. Below that, a structure with global Board
4113 Info data is placed, followed by the stack (growing downward).
4115 Additionally, some exception handler code is copied to the low 8 kB
4116 of DRAM (0x00000000 ... 0x00001FFF).
4118 So a typical memory configuration with 16 MB of DRAM could look like
4121 0x0000 0000 Exception Vector code
4124 0x0000 2000 Free for Application Use
4130 0x00FB FF20 Monitor Stack (Growing downward)
4131 0x00FB FFAC Board Info Data and permanent copy of global data
4132 0x00FC 0000 Malloc Arena
4135 0x00FE 0000 RAM Copy of Monitor Code
4136 ... eventually: LCD or video framebuffer
4137 ... eventually: pRAM (Protected RAM - unchanged by reset)
4138 0x00FF FFFF [End of RAM]
4141 System Initialization:
4142 ----------------------
4144 In the reset configuration, U-Boot starts at the reset entry point
4145 (on most PowerPC systems at address 0x00000100). Because of the reset
4146 configuration for CS0# this is a mirror of the onboard Flash memory.
4147 To be able to re-map memory U-Boot then jumps to its link address.
4148 To be able to implement the initialization code in C, a (small!)
4149 initial stack is set up in the internal Dual Ported RAM (in case CPUs
4150 which provide such a feature like MPC8xx or MPC8260), or in a locked
4151 part of the data cache. After that, U-Boot initializes the CPU core,
4152 the caches and the SIU.
4154 Next, all (potentially) available memory banks are mapped using a
4155 preliminary mapping. For example, we put them on 512 MB boundaries
4156 (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
4157 on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
4158 programmed for SDRAM access. Using the temporary configuration, a
4159 simple memory test is run that determines the size of the SDRAM
4162 When there is more than one SDRAM bank, and the banks are of
4163 different size, the largest is mapped first. For equal size, the first
4164 bank (CS2#) is mapped first. The first mapping is always for address
4165 0x00000000, with any additional banks following immediately to create
4166 contiguous memory starting from 0.
4168 Then, the monitor installs itself at the upper end of the SDRAM area
4169 and allocates memory for use by malloc() and for the global Board
4170 Info data; also, the exception vector code is copied to the low RAM
4171 pages, and the final stack is set up.
4173 Only after this relocation will you have a "normal" C environment;
4174 until that you are restricted in several ways, mostly because you are
4175 running from ROM, and because the code will have to be relocated to a
4179 U-Boot Porting Guide:
4180 ----------------------
4182 [Based on messages by Jerry Van Baren in the U-Boot-Users mailing
4186 int main(int argc, char *argv[])
4188 sighandler_t no_more_time;
4190 signal(SIGALRM, no_more_time);
4191 alarm(PROJECT_DEADLINE - toSec (3 * WEEK));
4193 if (available_money > available_manpower) {
4194 Pay consultant to port U-Boot;
4198 Download latest U-Boot source;
4200 Subscribe to u-boot mailing list;
4203 email("Hi, I am new to U-Boot, how do I get started?");
4206 Read the README file in the top level directory;
4207 Read http://www.denx.de/twiki/bin/view/DULG/Manual;
4208 Read applicable doc/*.README;
4209 Read the source, Luke;
4210 /* find . -name "*.[chS]" | xargs grep -i <keyword> */
4213 if (available_money > toLocalCurrency ($2500))
4216 Add a lot of aggravation and time;
4218 if (a similar board exists) { /* hopefully... */
4219 cp -a board/<similar> board/<myboard>
4220 cp include/configs/<similar>.h include/configs/<myboard>.h
4222 Create your own board support subdirectory;
4223 Create your own board include/configs/<myboard>.h file;
4225 Edit new board/<myboard> files
4226 Edit new include/configs/<myboard>.h
4231 Add / modify source code;
4235 email("Hi, I am having problems...");
4237 Send patch file to the U-Boot email list;
4238 if (reasonable critiques)
4239 Incorporate improvements from email list code review;
4241 Defend code as written;
4247 void no_more_time (int sig)
4256 All contributions to U-Boot should conform to the Linux kernel
4257 coding style; see the file "Documentation/CodingStyle" and the script
4258 "scripts/Lindent" in your Linux kernel source directory. In sources
4259 originating from U-Boot a style corresponding to "Lindent -pcs" (adding
4260 spaces before parameters to function calls) is actually used.
4262 Source files originating from a different project (for example the
4263 MTD subsystem) are generally exempt from these guidelines and are not
4264 reformated to ease subsequent migration to newer versions of those
4267 Please note that U-Boot is implemented in C (and to some small parts in
4268 Assembler); no C++ is used, so please do not use C++ style comments (//)
4271 Please also stick to the following formatting rules:
4272 - remove any trailing white space
4273 - use TAB characters for indentation, not spaces
4274 - make sure NOT to use DOS '\r\n' line feeds
4275 - do not add more than 2 empty lines to source files
4276 - do not add trailing empty lines to source files
4278 Submissions which do not conform to the standards may be returned
4279 with a request to reformat the changes.
4285 Since the number of patches for U-Boot is growing, we need to
4286 establish some rules. Submissions which do not conform to these rules
4287 may be rejected, even when they contain important and valuable stuff.
4289 Please see http://www.denx.de/wiki/U-Boot/Patches for details.
4291 Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>;
4292 see http://lists.denx.de/mailman/listinfo/u-boot
4294 When you send a patch, please include the following information with
4297 * For bug fixes: a description of the bug and how your patch fixes
4298 this bug. Please try to include a way of demonstrating that the
4299 patch actually fixes something.
4301 * For new features: a description of the feature and your
4304 * A CHANGELOG entry as plaintext (separate from the patch)
4306 * For major contributions, your entry to the CREDITS file
4308 * When you add support for a new board, don't forget to add this
4309 board to the MAKEALL script, too.
4311 * If your patch adds new configuration options, don't forget to
4312 document these in the README file.
4314 * The patch itself. If you are using git (which is *strongly*
4315 recommended) you can easily generate the patch using the
4316 "git-format-patch". If you then use "git-send-email" to send it to
4317 the U-Boot mailing list, you will avoid most of the common problems
4318 with some other mail clients.
4320 If you cannot use git, use "diff -purN OLD NEW". If your version of
4321 diff does not support these options, then get the latest version of
4324 The current directory when running this command shall be the parent
4325 directory of the U-Boot source tree (i. e. please make sure that
4326 your patch includes sufficient directory information for the
4329 We prefer patches as plain text. MIME attachments are discouraged,
4330 and compressed attachments must not be used.
4332 * If one logical set of modifications affects or creates several
4333 files, all these changes shall be submitted in a SINGLE patch file.
4335 * Changesets that contain different, unrelated modifications shall be
4336 submitted as SEPARATE patches, one patch per changeset.
4341 * Before sending the patch, run the MAKEALL script on your patched
4342 source tree and make sure that no errors or warnings are reported
4343 for any of the boards.
4345 * Keep your modifications to the necessary minimum: A patch
4346 containing several unrelated changes or arbitrary reformats will be
4347 returned with a request to re-formatting / split it.
4349 * If you modify existing code, make sure that your new code does not
4350 add to the memory footprint of the code ;-) Small is beautiful!
4351 When adding new features, these should compile conditionally only
4352 (using #ifdef), and the resulting code with the new feature
4353 disabled must not need more memory than the old code without your
4356 * Remember that there is a size limit of 100 kB per message on the
4357 u-boot mailing list. Bigger patches will be moderated. If they are
4358 reasonable and not too big, they will be acknowledged. But patches
4359 bigger than the size limit should be avoided.
projects / kernel / u-boot.git / blob