2 # (C) Copyright 2000 - 2008
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 U-Boot uses a 3 level version number containing a version, a
130 sub-version, and a patchlevel: "U-Boot-2.34.5" means version "2",
131 sub-version "34", and patchlevel "4".
133 The patchlevel is used to indicate certain stages of development
134 between released versions, i. e. officially released versions of
135 U-Boot will always have a patchlevel of "0".
141 - board Board dependent files
142 - common Misc architecture independent functions
143 - cpu CPU specific files
144 - 74xx_7xx Files specific to Freescale MPC74xx and 7xx CPUs
145 - arm720t Files specific to ARM 720 CPUs
146 - arm920t Files specific to ARM 920 CPUs
147 - at91rm9200 Files specific to Atmel AT91RM9200 CPU
148 - imx Files specific to Freescale MC9328 i.MX CPUs
149 - s3c24x0 Files specific to Samsung S3C24X0 CPUs
150 - arm925t Files specific to ARM 925 CPUs
151 - arm926ejs Files specific to ARM 926 CPUs
152 - arm1136 Files specific to ARM 1136 CPUs
153 - at32ap Files specific to Atmel AVR32 AP CPUs
154 - blackfin Files specific to Analog Devices Blackfin CPUs
155 - i386 Files specific to i386 CPUs
156 - ixp Files specific to Intel XScale IXP CPUs
157 - leon2 Files specific to Gaisler LEON2 SPARC CPU
158 - leon3 Files specific to Gaisler LEON3 SPARC CPU
159 - mcf52x2 Files specific to Freescale ColdFire MCF52x2 CPUs
160 - mcf5227x Files specific to Freescale ColdFire MCF5227x CPUs
161 - mcf532x Files specific to Freescale ColdFire MCF5329 CPUs
162 - mcf5445x Files specific to Freescale ColdFire MCF5445x CPUs
163 - mcf547x_8x Files specific to Freescale ColdFire MCF547x_8x CPUs
164 - mips Files specific to MIPS CPUs
165 - mpc5xx Files specific to Freescale MPC5xx CPUs
166 - mpc5xxx Files specific to Freescale MPC5xxx CPUs
167 - mpc8xx Files specific to Freescale MPC8xx CPUs
168 - mpc8220 Files specific to Freescale MPC8220 CPUs
169 - mpc824x Files specific to Freescale MPC824x CPUs
170 - mpc8260 Files specific to Freescale MPC8260 CPUs
171 - mpc85xx Files specific to Freescale MPC85xx CPUs
172 - nios Files specific to Altera NIOS CPUs
173 - nios2 Files specific to Altera Nios-II CPUs
174 - ppc4xx Files specific to AMCC PowerPC 4xx CPUs
175 - pxa Files specific to Intel XScale PXA CPUs
176 - s3c44b0 Files specific to Samsung S3C44B0 CPUs
177 - sa1100 Files specific to Intel StrongARM SA1100 CPUs
178 - disk Code for disk drive partition handling
179 - doc Documentation (don't expect too much)
180 - drivers Commonly used device drivers
181 - dtt Digital Thermometer and Thermostat drivers
182 - examples Example code for standalone applications, etc.
183 - include Header Files
184 - lib_arm Files generic to ARM architecture
185 - lib_avr32 Files generic to AVR32 architecture
186 - lib_blackfin Files generic to Blackfin architecture
187 - lib_generic Files generic to all architectures
188 - lib_i386 Files generic to i386 architecture
189 - lib_m68k Files generic to m68k architecture
190 - lib_mips Files generic to MIPS architecture
191 - lib_nios Files generic to NIOS architecture
192 - lib_ppc Files generic to PowerPC architecture
193 - lib_sparc Files generic to SPARC architecture
194 - libfdt Library files to support flattened device trees
195 - net Networking code
196 - post Power On Self Test
197 - rtc Real Time Clock drivers
198 - tools Tools to build S-Record or U-Boot images, etc.
200 Software Configuration:
201 =======================
203 Configuration is usually done using C preprocessor defines; the
204 rationale behind that is to avoid dead code whenever possible.
206 There are two classes of configuration variables:
208 * Configuration _OPTIONS_:
209 These are selectable by the user and have names beginning with
212 * Configuration _SETTINGS_:
213 These depend on the hardware etc. and should not be meddled with if
214 you don't know what you're doing; they have names beginning with
217 Later we will add a configuration tool - probably similar to or even
218 identical to what's used for the Linux kernel. Right now, we have to
219 do the configuration by hand, which means creating some symbolic
220 links and editing some configuration files. We use the TQM8xxL boards
224 Selection of Processor Architecture and Board Type:
225 ---------------------------------------------------
227 For all supported boards there are ready-to-use default
228 configurations available; just type "make <board_name>_config".
230 Example: For a TQM823L module type:
235 For the Cogent platform, you need to specify the CPU type as well;
236 e.g. "make cogent_mpc8xx_config". And also configure the cogent
237 directory according to the instructions in cogent/README.
240 Configuration Options:
241 ----------------------
243 Configuration depends on the combination of board and CPU type; all
244 such information is kept in a configuration file
245 "include/configs/<board_name>.h".
247 Example: For a TQM823L module, all configuration settings are in
248 "include/configs/TQM823L.h".
251 Many of the options are named exactly as the corresponding Linux
252 kernel configuration options. The intention is to make it easier to
253 build a config tool - later.
256 The following options need to be configured:
258 - CPU Type: Define exactly one, e.g. CONFIG_MPC85XX.
260 - Board Type: Define exactly one, e.g. CONFIG_MPC8540ADS.
262 - CPU Daughterboard Type: (if CONFIG_ATSTK1000 is defined)
263 Define exactly one, e.g. CONFIG_ATSTK1002
265 - CPU Module Type: (if CONFIG_COGENT is defined)
266 Define exactly one of
268 --- FIXME --- not tested yet:
269 CONFIG_CMA286_60, CONFIG_CMA286_21, CONFIG_CMA286_60P,
270 CONFIG_CMA287_23, CONFIG_CMA287_50
272 - Motherboard Type: (if CONFIG_COGENT is defined)
273 Define exactly one of
274 CONFIG_CMA101, CONFIG_CMA102
276 - Motherboard I/O Modules: (if CONFIG_COGENT is defined)
277 Define one or more of
280 - Motherboard Options: (if CONFIG_CMA101 or CONFIG_CMA102 are defined)
281 Define one or more of
282 CONFIG_LCD_HEARTBEAT - update a character position on
283 the LCD display every second with
286 - Board flavour: (if CONFIG_MPC8260ADS is defined)
289 CONFIG_SYS_8260ADS - original MPC8260ADS
290 CONFIG_SYS_8266ADS - MPC8266ADS
291 CONFIG_SYS_PQ2FADS - PQ2FADS-ZU or PQ2FADS-VR
292 CONFIG_SYS_8272ADS - MPC8272ADS
294 - MPC824X Family Member (if CONFIG_MPC824X is defined)
295 Define exactly one of
296 CONFIG_MPC8240, CONFIG_MPC8245
298 - 8xx CPU Options: (if using an MPC8xx CPU)
299 CONFIG_8xx_GCLK_FREQ - deprecated: CPU clock if
300 get_gclk_freq() cannot work
301 e.g. if there is no 32KHz
302 reference PIT/RTC clock
303 CONFIG_8xx_OSCLK - PLL input clock (either EXTCLK
306 - 859/866/885 CPU options: (if using a MPC859 or MPC866 or MPC885 CPU):
307 CONFIG_SYS_8xx_CPUCLK_MIN
308 CONFIG_SYS_8xx_CPUCLK_MAX
309 CONFIG_8xx_CPUCLK_DEFAULT
310 See doc/README.MPC866
312 CONFIG_SYS_MEASURE_CPUCLK
314 Define this to measure the actual CPU clock instead
315 of relying on the correctness of the configured
316 values. Mostly useful for board bringup to make sure
317 the PLL is locked at the intended frequency. Note
318 that this requires a (stable) reference clock (32 kHz
319 RTC clock or CONFIG_SYS_8XX_XIN)
321 CONFIG_SYS_DELAYED_ICACHE
323 Define this option if you want to enable the
324 ICache only when Code runs from RAM.
326 - Intel Monahans options:
327 CONFIG_SYS_MONAHANS_RUN_MODE_OSC_RATIO
329 Defines the Monahans run mode to oscillator
330 ratio. Valid values are 8, 16, 24, 31. The core
331 frequency is this value multiplied by 13 MHz.
333 CONFIG_SYS_MONAHANS_TURBO_RUN_MODE_RATIO
335 Defines the Monahans turbo mode to oscillator
336 ratio. Valid values are 1 (default if undefined) and
337 2. The core frequency as calculated above is multiplied
340 - Linux Kernel Interface:
343 U-Boot stores all clock information in Hz
344 internally. For binary compatibility with older Linux
345 kernels (which expect the clocks passed in the
346 bd_info data to be in MHz) the environment variable
347 "clocks_in_mhz" can be defined so that U-Boot
348 converts clock data to MHZ before passing it to the
350 When CONFIG_CLOCKS_IN_MHZ is defined, a definition of
351 "clocks_in_mhz=1" is automatically included in the
354 CONFIG_MEMSIZE_IN_BYTES [relevant for MIPS only]
356 When transferring memsize parameter to linux, some versions
357 expect it to be in bytes, others in MB.
358 Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes.
362 New kernel versions are expecting firmware settings to be
363 passed using flattened device trees (based on open firmware
367 * New libfdt-based support
368 * Adds the "fdt" command
369 * The bootm command automatically updates the fdt
371 OF_CPU - The proper name of the cpus node.
372 OF_SOC - The proper name of the soc node.
373 OF_TBCLK - The timebase frequency.
374 OF_STDOUT_PATH - The path to the console device
376 boards with QUICC Engines require OF_QE to set UCC MAC
379 CONFIG_OF_BOARD_SETUP
381 Board code has addition modification that it wants to make
382 to the flat device tree before handing it off to the kernel
386 This define fills in the correct boot CPU in the boot
387 param header, the default value is zero if undefined.
389 - vxWorks boot parameters:
391 bootvx constructs a valid bootline using the following
392 environments variables: bootfile, ipaddr, serverip, hostname.
393 It loads the vxWorks image pointed bootfile.
395 CONFIG_SYS_VXWORKS_BOOT_DEVICE - The vxworks device name
396 CONFIG_SYS_VXWORKS_MAC_PTR - Ethernet 6 byte MA -address
397 CONFIG_SYS_VXWORKS_SERVERNAME - Name of the server
398 CONFIG_SYS_VXWORKS_BOOT_ADDR - Address of boot parameters
400 CONFIG_SYS_VXWORKS_ADD_PARAMS
402 Add it at the end of the bootline. E.g "u=username pw=secret"
404 Note: If a "bootargs" environment is defined, it will overwride
405 the defaults discussed just above.
410 Define this if you want support for Amba PrimeCell PL010 UARTs.
414 Define this if you want support for Amba PrimeCell PL011 UARTs.
418 If you have Amba PrimeCell PL011 UARTs, set this variable to
419 the clock speed of the UARTs.
423 If you have Amba PrimeCell PL010 or PL011 UARTs on your board,
424 define this to a list of base addresses for each (supported)
425 port. See e.g. include/configs/versatile.h
429 Depending on board, define exactly one serial port
430 (like CONFIG_8xx_CONS_SMC1, CONFIG_8xx_CONS_SMC2,
431 CONFIG_8xx_CONS_SCC1, ...), or switch off the serial
432 console by defining CONFIG_8xx_CONS_NONE
434 Note: if CONFIG_8xx_CONS_NONE is defined, the serial
435 port routines must be defined elsewhere
436 (i.e. serial_init(), serial_getc(), ...)
439 Enables console device for a color framebuffer. Needs following
440 defines (cf. smiLynxEM, i8042, board/eltec/bab7xx)
441 VIDEO_FB_LITTLE_ENDIAN graphic memory organisation
443 VIDEO_HW_RECTFILL graphic chip supports
446 VIDEO_HW_BITBLT graphic chip supports
447 bit-blit (cf. smiLynxEM)
448 VIDEO_VISIBLE_COLS visible pixel columns
450 VIDEO_VISIBLE_ROWS visible pixel rows
451 VIDEO_PIXEL_SIZE bytes per pixel
452 VIDEO_DATA_FORMAT graphic data format
453 (0-5, cf. cfb_console.c)
454 VIDEO_FB_ADRS framebuffer address
455 VIDEO_KBD_INIT_FCT keyboard int fct
456 (i.e. i8042_kbd_init())
457 VIDEO_TSTC_FCT test char fct
459 VIDEO_GETC_FCT get char fct
461 CONFIG_CONSOLE_CURSOR cursor drawing on/off
462 (requires blink timer
464 CONFIG_SYS_CONSOLE_BLINK_COUNT blink interval (cf. i8042.c)
465 CONFIG_CONSOLE_TIME display time/date info in
467 (requires CONFIG_CMD_DATE)
468 CONFIG_VIDEO_LOGO display Linux logo in
470 CONFIG_VIDEO_BMP_LOGO use bmp_logo.h instead of
471 linux_logo.h for logo.
472 Requires CONFIG_VIDEO_LOGO
473 CONFIG_CONSOLE_EXTRA_INFO
474 additional board info beside
477 When CONFIG_CFB_CONSOLE is defined, video console is
478 default i/o. Serial console can be forced with
479 environment 'console=serial'.
481 When CONFIG_SILENT_CONSOLE is defined, all console
482 messages (by U-Boot and Linux!) can be silenced with
483 the "silent" environment variable. See
484 doc/README.silent for more information.
487 CONFIG_BAUDRATE - in bps
488 Select one of the baudrates listed in
489 CONFIG_SYS_BAUDRATE_TABLE, see below.
490 CONFIG_SYS_BRGCLK_PRESCALE, baudrate prescale
492 - Console Rx buffer length
493 With CONFIG_SYS_SMC_RXBUFLEN it is possible to define
494 the maximum receive buffer length for the SMC.
495 This option is actual only for 82xx and 8xx possible.
496 If using CONFIG_SYS_SMC_RXBUFLEN also CONFIG_SYS_MAXIDLE
497 must be defined, to setup the maximum idle timeout for
500 - Interrupt driven serial port input:
501 CONFIG_SERIAL_SOFTWARE_FIFO
504 Use an interrupt handler for receiving data on the
505 serial port. It also enables using hardware handshake
506 (RTS/CTS) and UART's built-in FIFO. Set the number of
507 bytes the interrupt driven input buffer should have.
509 Leave undefined to disable this feature, including
510 disable the buffer and hardware handshake.
512 - Console UART Number:
516 If defined internal UART1 (and not UART0) is used
517 as default U-Boot console.
519 - Boot Delay: CONFIG_BOOTDELAY - in seconds
520 Delay before automatically booting the default image;
521 set to -1 to disable autoboot.
523 See doc/README.autoboot for these options that
524 work with CONFIG_BOOTDELAY. None are required.
525 CONFIG_BOOT_RETRY_TIME
526 CONFIG_BOOT_RETRY_MIN
527 CONFIG_AUTOBOOT_KEYED
528 CONFIG_AUTOBOOT_PROMPT
529 CONFIG_AUTOBOOT_DELAY_STR
530 CONFIG_AUTOBOOT_STOP_STR
531 CONFIG_AUTOBOOT_DELAY_STR2
532 CONFIG_AUTOBOOT_STOP_STR2
533 CONFIG_ZERO_BOOTDELAY_CHECK
534 CONFIG_RESET_TO_RETRY
538 Only needed when CONFIG_BOOTDELAY is enabled;
539 define a command string that is automatically executed
540 when no character is read on the console interface
541 within "Boot Delay" after reset.
544 This can be used to pass arguments to the bootm
545 command. The value of CONFIG_BOOTARGS goes into the
546 environment value "bootargs".
548 CONFIG_RAMBOOT and CONFIG_NFSBOOT
549 The value of these goes into the environment as
550 "ramboot" and "nfsboot" respectively, and can be used
551 as a convenience, when switching between booting from
557 When this option is #defined, the existence of the
558 environment variable "preboot" will be checked
559 immediately before starting the CONFIG_BOOTDELAY
560 countdown and/or running the auto-boot command resp.
561 entering interactive mode.
563 This feature is especially useful when "preboot" is
564 automatically generated or modified. For an example
565 see the LWMON board specific code: here "preboot" is
566 modified when the user holds down a certain
567 combination of keys on the (special) keyboard when
570 - Serial Download Echo Mode:
572 If defined to 1, all characters received during a
573 serial download (using the "loads" command) are
574 echoed back. This might be needed by some terminal
575 emulations (like "cu"), but may as well just take
576 time on others. This setting #define's the initial
577 value of the "loads_echo" environment variable.
579 - Kgdb Serial Baudrate: (if CONFIG_CMD_KGDB is defined)
581 Select one of the baudrates listed in
582 CONFIG_SYS_BAUDRATE_TABLE, see below.
585 Monitor commands can be included or excluded
586 from the build by using the #include files
587 "config_cmd_all.h" and #undef'ing unwanted
588 commands, or using "config_cmd_default.h"
589 and augmenting with additional #define's
592 The default command configuration includes all commands
593 except those marked below with a "*".
595 CONFIG_CMD_ASKENV * ask for env variable
596 CONFIG_CMD_BDI bdinfo
597 CONFIG_CMD_BEDBUG * Include BedBug Debugger
598 CONFIG_CMD_BMP * BMP support
599 CONFIG_CMD_BSP * Board specific commands
600 CONFIG_CMD_BOOTD bootd
601 CONFIG_CMD_CACHE * icache, dcache
602 CONFIG_CMD_CONSOLE coninfo
603 CONFIG_CMD_DATE * support for RTC, date/time...
604 CONFIG_CMD_DHCP * DHCP support
605 CONFIG_CMD_DIAG * Diagnostics
606 CONFIG_CMD_DS4510 * ds4510 I2C gpio commands
607 CONFIG_CMD_DS4510_INFO * ds4510 I2C info command
608 CONFIG_CMD_DS4510_MEM * ds4510 I2C eeprom/sram commansd
609 CONFIG_CMD_DS4510_RST * ds4510 I2C rst command
610 CONFIG_CMD_DTT * Digital Therm and Thermostat
611 CONFIG_CMD_ECHO echo arguments
612 CONFIG_CMD_EEPROM * EEPROM read/write support
613 CONFIG_CMD_ELF * bootelf, bootvx
614 CONFIG_CMD_SAVEENV saveenv
615 CONFIG_CMD_FDC * Floppy Disk Support
616 CONFIG_CMD_FAT * FAT partition support
617 CONFIG_CMD_FDOS * Dos diskette Support
618 CONFIG_CMD_FLASH flinfo, erase, protect
619 CONFIG_CMD_FPGA FPGA device initialization support
620 CONFIG_CMD_HWFLOW * RTS/CTS hw flow control
621 CONFIG_CMD_I2C * I2C serial bus support
622 CONFIG_CMD_IDE * IDE harddisk support
623 CONFIG_CMD_IMI iminfo
624 CONFIG_CMD_IMLS List all found images
625 CONFIG_CMD_IMMAP * IMMR dump support
626 CONFIG_CMD_IRQ * irqinfo
627 CONFIG_CMD_ITEST Integer/string test of 2 values
628 CONFIG_CMD_JFFS2 * JFFS2 Support
629 CONFIG_CMD_KGDB * kgdb
630 CONFIG_CMD_LOADB loadb
631 CONFIG_CMD_LOADS loads
632 CONFIG_CMD_MD5SUM print md5 message digest
633 (requires CONFIG_CMD_MEMORY and CONFIG_MD5)
634 CONFIG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base,
636 CONFIG_CMD_MISC Misc functions like sleep etc
637 CONFIG_CMD_MMC * MMC memory mapped support
638 CONFIG_CMD_MII * MII utility commands
639 CONFIG_CMD_MTDPARTS * MTD partition support
640 CONFIG_CMD_NAND * NAND support
641 CONFIG_CMD_NET bootp, tftpboot, rarpboot
642 CONFIG_CMD_PCA953X * PCA953x I2C gpio commands
643 CONFIG_CMD_PCA953X_INFO * PCA953x I2C gpio info command
644 CONFIG_CMD_PCI * pciinfo
645 CONFIG_CMD_PCMCIA * PCMCIA support
646 CONFIG_CMD_PING * send ICMP ECHO_REQUEST to network
648 CONFIG_CMD_PORTIO * Port I/O
649 CONFIG_CMD_REGINFO * Register dump
650 CONFIG_CMD_RUN run command in env variable
651 CONFIG_CMD_SAVES * save S record dump
652 CONFIG_CMD_SCSI * SCSI Support
653 CONFIG_CMD_SDRAM * print SDRAM configuration information
654 (requires CONFIG_CMD_I2C)
655 CONFIG_CMD_SETGETDCR Support for DCR Register access
657 CONFIG_CMD_SHA1 print sha1 memory digest
658 (requires CONFIG_CMD_MEMORY)
659 CONFIG_CMD_SOURCE "source" command Support
660 CONFIG_CMD_SPI * SPI serial bus support
661 CONFIG_CMD_USB * USB support
662 CONFIG_CMD_VFD * VFD support (TRAB)
663 CONFIG_CMD_CDP * Cisco Discover Protocol support
664 CONFIG_CMD_FSL * Microblaze FSL support
667 EXAMPLE: If you want all functions except of network
668 support you can write:
670 #include "config_cmd_all.h"
671 #undef CONFIG_CMD_NET
674 fdt (flattened device tree) command: CONFIG_OF_LIBFDT
676 Note: Don't enable the "icache" and "dcache" commands
677 (configuration option CONFIG_CMD_CACHE) unless you know
678 what you (and your U-Boot users) are doing. Data
679 cache cannot be enabled on systems like the 8xx or
680 8260 (where accesses to the IMMR region must be
681 uncached), and it cannot be disabled on all other
682 systems where we (mis-) use the data cache to hold an
683 initial stack and some data.
686 XXX - this list needs to get updated!
690 If this variable is defined, it enables watchdog
691 support. There must be support in the platform specific
692 code for a watchdog. For the 8xx and 8260 CPUs, the
693 SIU Watchdog feature is enabled in the SYPCR
697 CONFIG_VERSION_VARIABLE
698 If this variable is defined, an environment variable
699 named "ver" is created by U-Boot showing the U-Boot
700 version as printed by the "version" command.
701 This variable is readonly.
705 When CONFIG_CMD_DATE is selected, the type of the RTC
706 has to be selected, too. Define exactly one of the
709 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx
710 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC
711 CONFIG_RTC_MC13783 - use MC13783 RTC
712 CONFIG_RTC_MC146818 - use MC146818 RTC
713 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC
714 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC
715 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC
716 CONFIG_RTC_DS164x - use Dallas DS164x RTC
717 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC
718 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC
719 CONFIG_SYS_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337
721 Note that if the RTC uses I2C, then the I2C interface
722 must also be configured. See I2C Support, below.
725 CONFIG_PCA953X - use NXP's PCA953X series I2C GPIO
726 CONFIG_PCA953X_INFO - enable pca953x info command
728 Note that if the GPIO device uses I2C, then the I2C interface
729 must also be configured. See I2C Support, below.
733 When CONFIG_TIMESTAMP is selected, the timestamp
734 (date and time) of an image is printed by image
735 commands like bootm or iminfo. This option is
736 automatically enabled when you select CONFIG_CMD_DATE .
739 CONFIG_MAC_PARTITION and/or CONFIG_DOS_PARTITION
740 and/or CONFIG_ISO_PARTITION and/or CONFIG_EFI_PARTITION
742 If IDE or SCSI support is enabled (CONFIG_CMD_IDE or
743 CONFIG_CMD_SCSI) you must configure support for at
744 least one partition type as well.
747 CONFIG_IDE_RESET_ROUTINE - this is defined in several
748 board configurations files but used nowhere!
750 CONFIG_IDE_RESET - is this is defined, IDE Reset will
751 be performed by calling the function
752 ide_set_reset(int reset)
753 which has to be defined in a board specific file
758 Set this to enable ATAPI support.
763 Set this to enable support for disks larger than 137GB
764 Also look at CONFIG_SYS_64BIT_LBA ,CONFIG_SYS_64BIT_VSPRINTF and CONFIG_SYS_64BIT_STRTOUL
765 Whithout these , LBA48 support uses 32bit variables and will 'only'
766 support disks up to 2.1TB.
768 CONFIG_SYS_64BIT_LBA:
769 When enabled, makes the IDE subsystem use 64bit sector addresses.
773 At the moment only there is only support for the
774 SYM53C8XX SCSI controller; define
775 CONFIG_SCSI_SYM53C8XX to enable it.
777 CONFIG_SYS_SCSI_MAX_LUN [8], CONFIG_SYS_SCSI_MAX_SCSI_ID [7] and
778 CONFIG_SYS_SCSI_MAX_DEVICE [CONFIG_SYS_SCSI_MAX_SCSI_ID *
779 CONFIG_SYS_SCSI_MAX_LUN] can be adjusted to define the
780 maximum numbers of LUNs, SCSI ID's and target
782 CONFIG_SYS_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz)
784 - NETWORK Support (PCI):
786 Support for Intel 8254x gigabit chips.
788 CONFIG_E1000_FALLBACK_MAC
789 default MAC for empty EEPROM after production.
792 Support for Intel 82557/82559/82559ER chips.
793 Optional CONFIG_EEPRO100_SROM_WRITE enables EEPROM
794 write routine for first time initialisation.
797 Support for Digital 2114x chips.
798 Optional CONFIG_TULIP_SELECT_MEDIA for board specific
799 modem chip initialisation (KS8761/QS6611).
802 Support for National dp83815 chips.
805 Support for National dp8382[01] gigabit chips.
807 - NETWORK Support (other):
809 CONFIG_DRIVER_LAN91C96
810 Support for SMSC's LAN91C96 chips.
813 Define this to hold the physical address
814 of the LAN91C96's I/O space
816 CONFIG_LAN91C96_USE_32_BIT
817 Define this to enable 32 bit addressing
819 CONFIG_DRIVER_SMC91111
820 Support for SMSC's LAN91C111 chip
823 Define this to hold the physical address
824 of the device (I/O space)
826 CONFIG_SMC_USE_32_BIT
827 Define this if data bus is 32 bits
829 CONFIG_SMC_USE_IOFUNCS
830 Define this to use i/o functions instead of macros
831 (some hardware wont work with macros)
833 CONFIG_DRIVER_SMC911X
834 Support for SMSC's LAN911x and LAN921x chips
836 CONFIG_DRIVER_SMC911X_BASE
837 Define this to hold the physical address
838 of the device (I/O space)
840 CONFIG_DRIVER_SMC911X_32_BIT
841 Define this if data bus is 32 bits
843 CONFIG_DRIVER_SMC911X_16_BIT
844 Define this if data bus is 16 bits. If your processor
845 automatically converts one 32 bit word to two 16 bit
846 words you may also try CONFIG_DRIVER_SMC911X_32_BIT.
849 At the moment only the UHCI host controller is
850 supported (PIP405, MIP405, MPC5200); define
851 CONFIG_USB_UHCI to enable it.
852 define CONFIG_USB_KEYBOARD to enable the USB Keyboard
853 and define CONFIG_USB_STORAGE to enable the USB
856 Supported are USB Keyboards and USB Floppy drives
858 MPC5200 USB requires additional defines:
860 for 528 MHz Clock: 0x0001bbbb
864 for differential drivers: 0x00001000
865 for single ended drivers: 0x00005000
866 for differential drivers on PSC3: 0x00000100
867 for single ended drivers on PSC3: 0x00004100
868 CONFIG_SYS_USB_EVENT_POLL
869 May be defined to allow interrupt polling
870 instead of using asynchronous interrupts
873 Define the below if you wish to use the USB console.
874 Once firmware is rebuilt from a serial console issue the
875 command "setenv stdin usbtty; setenv stdout usbtty" and
876 attach your USB cable. The Unix command "dmesg" should print
877 it has found a new device. The environment variable usbtty
878 can be set to gserial or cdc_acm to enable your device to
879 appear to a USB host as a Linux gserial device or a
880 Common Device Class Abstract Control Model serial device.
881 If you select usbtty = gserial you should be able to enumerate
883 # modprobe usbserial vendor=0xVendorID product=0xProductID
884 else if using cdc_acm, simply setting the environment
885 variable usbtty to be cdc_acm should suffice. The following
886 might be defined in YourBoardName.h
889 Define this to build a UDC device
892 Define this to have a tty type of device available to
893 talk to the UDC device
895 CONFIG_SYS_CONSOLE_IS_IN_ENV
896 Define this if you want stdin, stdout &/or stderr to
900 CONFIG_SYS_USB_EXTC_CLK 0xBLAH
901 Derive USB clock from external clock "blah"
902 - CONFIG_SYS_USB_EXTC_CLK 0x02
904 CONFIG_SYS_USB_BRG_CLK 0xBLAH
905 Derive USB clock from brgclk
906 - CONFIG_SYS_USB_BRG_CLK 0x04
908 If you have a USB-IF assigned VendorID then you may wish to
909 define your own vendor specific values either in BoardName.h
910 or directly in usbd_vendor_info.h. If you don't define
911 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME,
912 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot
913 should pretend to be a Linux device to it's target host.
915 CONFIG_USBD_MANUFACTURER
916 Define this string as the name of your company for
917 - CONFIG_USBD_MANUFACTURER "my company"
919 CONFIG_USBD_PRODUCT_NAME
920 Define this string as the name of your product
921 - CONFIG_USBD_PRODUCT_NAME "acme usb device"
924 Define this as your assigned Vendor ID from the USB
925 Implementors Forum. This *must* be a genuine Vendor ID
926 to avoid polluting the USB namespace.
927 - CONFIG_USBD_VENDORID 0xFFFF
929 CONFIG_USBD_PRODUCTID
930 Define this as the unique Product ID
932 - CONFIG_USBD_PRODUCTID 0xFFFF
936 The MMC controller on the Intel PXA is supported. To
937 enable this define CONFIG_MMC. The MMC can be
938 accessed from the boot prompt by mapping the device
939 to physical memory similar to flash. Command line is
940 enabled with CONFIG_CMD_MMC. The MMC driver also works with
941 the FAT fs. This is enabled with CONFIG_CMD_FAT.
943 - Journaling Flash filesystem support:
944 CONFIG_JFFS2_NAND, CONFIG_JFFS2_NAND_OFF, CONFIG_JFFS2_NAND_SIZE,
945 CONFIG_JFFS2_NAND_DEV
946 Define these for a default partition on a NAND device
948 CONFIG_SYS_JFFS2_FIRST_SECTOR,
949 CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS
950 Define these for a default partition on a NOR device
952 CONFIG_SYS_JFFS_CUSTOM_PART
953 Define this to create an own partition. You have to provide a
954 function struct part_info* jffs2_part_info(int part_num)
956 If you define only one JFFS2 partition you may also want to
957 #define CONFIG_SYS_JFFS_SINGLE_PART 1
958 to disable the command chpart. This is the default when you
959 have not defined a custom partition
964 Define this to enable standard (PC-Style) keyboard
968 Standard PC keyboard driver with US (is default) and
969 GERMAN key layout (switch via environment 'keymap=de') support.
970 Export function i8042_kbd_init, i8042_tstc and i8042_getc
971 for cfb_console. Supports cursor blinking.
976 Define this to enable video support (for output to
981 Enable Chips & Technologies 69000 Video chip
983 CONFIG_VIDEO_SMI_LYNXEM
984 Enable Silicon Motion SMI 712/710/810 Video chip. The
985 video output is selected via environment 'videoout'
986 (1 = LCD and 2 = CRT). If videoout is undefined, CRT is
989 For the CT69000 and SMI_LYNXEM drivers, videomode is
990 selected via environment 'videomode'. Two different ways
992 - "videomode=num" 'num' is a standard LiLo mode numbers.
993 Following standard modes are supported (* is default):
995 Colors 640x480 800x600 1024x768 1152x864 1280x1024
996 -------------+---------------------------------------------
997 8 bits | 0x301* 0x303 0x305 0x161 0x307
998 15 bits | 0x310 0x313 0x316 0x162 0x319
999 16 bits | 0x311 0x314 0x317 0x163 0x31A
1000 24 bits | 0x312 0x315 0x318 ? 0x31B
1001 -------------+---------------------------------------------
1002 (i.e. setenv videomode 317; saveenv; reset;)
1004 - "videomode=bootargs" all the video parameters are parsed
1005 from the bootargs. (See drivers/video/videomodes.c)
1008 CONFIG_VIDEO_SED13806
1009 Enable Epson SED13806 driver. This driver supports 8bpp
1010 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP
1011 or CONFIG_VIDEO_SED13806_16BPP
1016 Define this to enable a custom keyboard support.
1017 This simply calls drv_keyboard_init() which must be
1018 defined in your board-specific files.
1019 The only board using this so far is RBC823.
1021 - LCD Support: CONFIG_LCD
1023 Define this to enable LCD support (for output to LCD
1024 display); also select one of the supported displays
1025 by defining one of these:
1029 HITACHI TX09D70VM1CCA, 3.5", 240x320.
1031 CONFIG_NEC_NL6448AC33:
1033 NEC NL6448AC33-18. Active, color, single scan.
1035 CONFIG_NEC_NL6448BC20
1037 NEC NL6448BC20-08. 6.5", 640x480.
1038 Active, color, single scan.
1040 CONFIG_NEC_NL6448BC33_54
1042 NEC NL6448BC33-54. 10.4", 640x480.
1043 Active, color, single scan.
1047 Sharp 320x240. Active, color, single scan.
1048 It isn't 16x9, and I am not sure what it is.
1050 CONFIG_SHARP_LQ64D341
1052 Sharp LQ64D341 display, 640x480.
1053 Active, color, single scan.
1057 HLD1045 display, 640x480.
1058 Active, color, single scan.
1062 Optrex CBL50840-2 NF-FW 99 22 M5
1064 Hitachi LMG6912RPFC-00T
1068 320x240. Black & white.
1070 Normally display is black on white background; define
1071 CONFIG_SYS_WHITE_ON_BLACK to get it inverted.
1073 - Splash Screen Support: CONFIG_SPLASH_SCREEN
1075 If this option is set, the environment is checked for
1076 a variable "splashimage". If found, the usual display
1077 of logo, copyright and system information on the LCD
1078 is suppressed and the BMP image at the address
1079 specified in "splashimage" is loaded instead. The
1080 console is redirected to the "nulldev", too. This
1081 allows for a "silent" boot where a splash screen is
1082 loaded very quickly after power-on.
1084 CONFIG_SPLASH_SCREEN_ALIGN
1086 If this option is set the splash image can be freely positioned
1087 on the screen. Environment variable "splashpos" specifies the
1088 position as "x,y". If a positive number is given it is used as
1089 number of pixel from left/top. If a negative number is given it
1090 is used as number of pixel from right/bottom. You can also
1091 specify 'm' for centering the image.
1094 setenv splashpos m,m
1095 => image at center of screen
1097 setenv splashpos 30,20
1098 => image at x = 30 and y = 20
1100 setenv splashpos -10,m
1101 => vertically centered image
1102 at x = dspWidth - bmpWidth - 9
1104 - Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP
1106 If this option is set, additionally to standard BMP
1107 images, gzipped BMP images can be displayed via the
1108 splashscreen support or the bmp command.
1110 - Compression support:
1113 If this option is set, support for bzip2 compressed
1114 images is included. If not, only uncompressed and gzip
1115 compressed images are supported.
1117 NOTE: the bzip2 algorithm requires a lot of RAM, so
1118 the malloc area (as defined by CONFIG_SYS_MALLOC_LEN) should
1123 If this option is set, support for lzma compressed
1126 Note: The LZMA algorithm adds between 2 and 4KB of code and it
1127 requires an amount of dynamic memory that is given by the
1130 (1846 + 768 << (lc + lp)) * sizeof(uint16)
1132 Where lc and lp stand for, respectively, Literal context bits
1133 and Literal pos bits.
1135 This value is upper-bounded by 14MB in the worst case. Anyway,
1136 for a ~4MB large kernel image, we have lc=3 and lp=0 for a
1137 total amount of (1846 + 768 << (3 + 0)) * 2 = ~41KB... that is
1138 a very small buffer.
1140 Use the lzmainfo tool to determinate the lc and lp values and
1141 then calculate the amount of needed dynamic memory (ensuring
1142 the appropriate CONFIG_SYS_MALLOC_LEN value).
1147 The address of PHY on MII bus.
1149 CONFIG_PHY_CLOCK_FREQ (ppc4xx)
1151 The clock frequency of the MII bus
1155 If this option is set, support for speed/duplex
1156 detection of gigabit PHY is included.
1158 CONFIG_PHY_RESET_DELAY
1160 Some PHY like Intel LXT971A need extra delay after
1161 reset before any MII register access is possible.
1162 For such PHY, set this option to the usec delay
1163 required. (minimum 300usec for LXT971A)
1165 CONFIG_PHY_CMD_DELAY (ppc4xx)
1167 Some PHY like Intel LXT971A need extra delay after
1168 command issued before MII status register can be read
1178 Define a default value for Ethernet address to use
1179 for the respective Ethernet interface, in case this
1180 is not determined automatically.
1185 Define a default value for the IP address to use for
1186 the default Ethernet interface, in case this is not
1187 determined through e.g. bootp.
1189 - Server IP address:
1192 Defines a default value for the IP address of a TFTP
1193 server to contact when using the "tftboot" command.
1195 CONFIG_KEEP_SERVERADDR
1197 Keeps the server's MAC address, in the env 'serveraddr'
1198 for passing to bootargs (like Linux's netconsole option)
1200 - Multicast TFTP Mode:
1203 Defines whether you want to support multicast TFTP as per
1204 rfc-2090; for example to work with atftp. Lets lots of targets
1205 tftp down the same boot image concurrently. Note: the Ethernet
1206 driver in use must provide a function: mcast() to join/leave a
1209 CONFIG_BOOTP_RANDOM_DELAY
1210 - BOOTP Recovery Mode:
1211 CONFIG_BOOTP_RANDOM_DELAY
1213 If you have many targets in a network that try to
1214 boot using BOOTP, you may want to avoid that all
1215 systems send out BOOTP requests at precisely the same
1216 moment (which would happen for instance at recovery
1217 from a power failure, when all systems will try to
1218 boot, thus flooding the BOOTP server. Defining
1219 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
1220 inserted before sending out BOOTP requests. The
1221 following delays are inserted then:
1223 1st BOOTP request: delay 0 ... 1 sec
1224 2nd BOOTP request: delay 0 ... 2 sec
1225 3rd BOOTP request: delay 0 ... 4 sec
1227 BOOTP requests: delay 0 ... 8 sec
1229 - DHCP Advanced Options:
1230 You can fine tune the DHCP functionality by defining
1231 CONFIG_BOOTP_* symbols:
1233 CONFIG_BOOTP_SUBNETMASK
1234 CONFIG_BOOTP_GATEWAY
1235 CONFIG_BOOTP_HOSTNAME
1236 CONFIG_BOOTP_NISDOMAIN
1237 CONFIG_BOOTP_BOOTPATH
1238 CONFIG_BOOTP_BOOTFILESIZE
1241 CONFIG_BOOTP_SEND_HOSTNAME
1242 CONFIG_BOOTP_NTPSERVER
1243 CONFIG_BOOTP_TIMEOFFSET
1244 CONFIG_BOOTP_VENDOREX
1246 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip
1247 environment variable, not the BOOTP server.
1249 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS
1250 serverip from a DHCP server, it is possible that more
1251 than one DNS serverip is offered to the client.
1252 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS
1253 serverip will be stored in the additional environment
1254 variable "dnsip2". The first DNS serverip is always
1255 stored in the variable "dnsip", when CONFIG_BOOTP_DNS
1258 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable
1259 to do a dynamic update of a DNS server. To do this, they
1260 need the hostname of the DHCP requester.
1261 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content
1262 of the "hostname" environment variable is passed as
1263 option 12 to the DHCP server.
1265 CONFIG_BOOTP_DHCP_REQUEST_DELAY
1267 A 32bit value in microseconds for a delay between
1268 receiving a "DHCP Offer" and sending the "DHCP Request".
1269 This fixes a problem with certain DHCP servers that don't
1270 respond 100% of the time to a "DHCP request". E.g. On an
1271 AT91RM9200 processor running at 180MHz, this delay needed
1272 to be *at least* 15,000 usec before a Windows Server 2003
1273 DHCP server would reply 100% of the time. I recommend at
1274 least 50,000 usec to be safe. The alternative is to hope
1275 that one of the retries will be successful but note that
1276 the DHCP timeout and retry process takes a longer than
1280 CONFIG_CDP_DEVICE_ID
1282 The device id used in CDP trigger frames.
1284 CONFIG_CDP_DEVICE_ID_PREFIX
1286 A two character string which is prefixed to the MAC address
1291 A printf format string which contains the ascii name of
1292 the port. Normally is set to "eth%d" which sets
1293 eth0 for the first Ethernet, eth1 for the second etc.
1295 CONFIG_CDP_CAPABILITIES
1297 A 32bit integer which indicates the device capabilities;
1298 0x00000010 for a normal host which does not forwards.
1302 An ascii string containing the version of the software.
1306 An ascii string containing the name of the platform.
1310 A 32bit integer sent on the trigger.
1312 CONFIG_CDP_POWER_CONSUMPTION
1314 A 16bit integer containing the power consumption of the
1315 device in .1 of milliwatts.
1317 CONFIG_CDP_APPLIANCE_VLAN_TYPE
1319 A byte containing the id of the VLAN.
1321 - Status LED: CONFIG_STATUS_LED
1323 Several configurations allow to display the current
1324 status using a LED. For instance, the LED will blink
1325 fast while running U-Boot code, stop blinking as
1326 soon as a reply to a BOOTP request was received, and
1327 start blinking slow once the Linux kernel is running
1328 (supported by a status LED driver in the Linux
1329 kernel). Defining CONFIG_STATUS_LED enables this
1332 - CAN Support: CONFIG_CAN_DRIVER
1334 Defining CONFIG_CAN_DRIVER enables CAN driver support
1335 on those systems that support this (optional)
1336 feature, like the TQM8xxL modules.
1338 - I2C Support: CONFIG_HARD_I2C | CONFIG_SOFT_I2C
1340 These enable I2C serial bus commands. Defining either of
1341 (but not both of) CONFIG_HARD_I2C or CONFIG_SOFT_I2C will
1342 include the appropriate I2C driver for the selected CPU.
1344 This will allow you to use i2c commands at the u-boot
1345 command line (as long as you set CONFIG_CMD_I2C in
1346 CONFIG_COMMANDS) and communicate with i2c based realtime
1347 clock chips. See common/cmd_i2c.c for a description of the
1348 command line interface.
1350 CONFIG_HARD_I2C selects a hardware I2C controller.
1352 CONFIG_SOFT_I2C configures u-boot to use a software (aka
1353 bit-banging) driver instead of CPM or similar hardware
1356 There are several other quantities that must also be
1357 defined when you define CONFIG_HARD_I2C or CONFIG_SOFT_I2C.
1359 In both cases you will need to define CONFIG_SYS_I2C_SPEED
1360 to be the frequency (in Hz) at which you wish your i2c bus
1361 to run and CONFIG_SYS_I2C_SLAVE to be the address of this node (ie
1362 the CPU's i2c node address).
1364 Now, the u-boot i2c code for the mpc8xx (cpu/mpc8xx/i2c.c)
1365 sets the CPU up as a master node and so its address should
1366 therefore be cleared to 0 (See, eg, MPC823e User's Manual
1367 p.16-473). So, set CONFIG_SYS_I2C_SLAVE to 0.
1369 That's all that's required for CONFIG_HARD_I2C.
1371 If you use the software i2c interface (CONFIG_SOFT_I2C)
1372 then the following macros need to be defined (examples are
1373 from include/configs/lwmon.h):
1377 (Optional). Any commands necessary to enable the I2C
1378 controller or configure ports.
1380 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
1384 (Only for MPC8260 CPU). The I/O port to use (the code
1385 assumes both bits are on the same port). Valid values
1386 are 0..3 for ports A..D.
1390 The code necessary to make the I2C data line active
1391 (driven). If the data line is open collector, this
1394 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
1398 The code necessary to make the I2C data line tri-stated
1399 (inactive). If the data line is open collector, this
1402 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
1406 Code that returns TRUE if the I2C data line is high,
1409 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
1413 If <bit> is TRUE, sets the I2C data line high. If it
1414 is FALSE, it clears it (low).
1416 eg: #define I2C_SDA(bit) \
1417 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
1418 else immr->im_cpm.cp_pbdat &= ~PB_SDA
1422 If <bit> is TRUE, sets the I2C clock line high. If it
1423 is FALSE, it clears it (low).
1425 eg: #define I2C_SCL(bit) \
1426 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
1427 else immr->im_cpm.cp_pbdat &= ~PB_SCL
1431 This delay is invoked four times per clock cycle so this
1432 controls the rate of data transfer. The data rate thus
1433 is 1 / (I2C_DELAY * 4). Often defined to be something
1436 #define I2C_DELAY udelay(2)
1438 CONFIG_SYS_I2C_INIT_BOARD
1440 When a board is reset during an i2c bus transfer
1441 chips might think that the current transfer is still
1442 in progress. On some boards it is possible to access
1443 the i2c SCLK line directly, either by using the
1444 processor pin as a GPIO or by having a second pin
1445 connected to the bus. If this option is defined a
1446 custom i2c_init_board() routine in boards/xxx/board.c
1447 is run early in the boot sequence.
1449 CONFIG_I2CFAST (PPC405GP|PPC405EP only)
1451 This option enables configuration of bi_iic_fast[] flags
1452 in u-boot bd_info structure based on u-boot environment
1453 variable "i2cfast". (see also i2cfast)
1455 CONFIG_I2C_MULTI_BUS
1457 This option allows the use of multiple I2C buses, each of which
1458 must have a controller. At any point in time, only one bus is
1459 active. To switch to a different bus, use the 'i2c dev' command.
1460 Note that bus numbering is zero-based.
1462 CONFIG_SYS_I2C_NOPROBES
1464 This option specifies a list of I2C devices that will be skipped
1465 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS
1466 is set, specify a list of bus-device pairs. Otherwise, specify
1467 a 1D array of device addresses
1470 #undef CONFIG_I2C_MULTI_BUS
1471 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68}
1473 will skip addresses 0x50 and 0x68 on a board with one I2C bus
1475 #define CONFIG_I2C_MULTI_BUS
1476 #define CONFIG_SYS_I2C_MULTI_NOPROBES {{0,0x50},{0,0x68},{1,0x54}}
1478 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1
1480 CONFIG_SYS_SPD_BUS_NUM
1482 If defined, then this indicates the I2C bus number for DDR SPD.
1483 If not defined, then U-Boot assumes that SPD is on I2C bus 0.
1485 CONFIG_SYS_RTC_BUS_NUM
1487 If defined, then this indicates the I2C bus number for the RTC.
1488 If not defined, then U-Boot assumes that RTC is on I2C bus 0.
1490 CONFIG_SYS_DTT_BUS_NUM
1492 If defined, then this indicates the I2C bus number for the DTT.
1493 If not defined, then U-Boot assumes that DTT is on I2C bus 0.
1495 CONFIG_SYS_I2C_DTT_ADDR:
1497 If defined, specifies the I2C address of the DTT device.
1498 If not defined, then U-Boot uses predefined value for
1499 specified DTT device.
1503 Define this option if you want to use Freescale's I2C driver in
1504 drivers/i2c/fsl_i2c.c.
1508 Define this option if you have I2C devices reached over 1 .. n
1509 I2C Muxes like the pca9544a. This option addes a new I2C
1510 Command "i2c bus [muxtype:muxaddr:muxchannel]" which adds a
1511 new I2C Bus to the existing I2C Busses. If you select the
1512 new Bus with "i2c dev", u-bbot sends first the commandos for
1513 the muxes to activate this new "bus".
1515 CONFIG_I2C_MULTI_BUS must be also defined, to use this
1519 Adding a new I2C Bus reached over 2 pca9544a muxes
1520 The First mux with address 70 and channel 6
1521 The Second mux with address 71 and channel 4
1523 => i2c bus pca9544a:70:6:pca9544a:71:4
1525 Use the "i2c bus" command without parameter, to get a list
1526 of I2C Busses with muxes:
1529 Busses reached over muxes:
1531 reached over Mux(es):
1534 reached over Mux(es):
1539 If you now switch to the new I2C Bus 3 with "i2c dev 3"
1540 u-boot sends First the Commando to the mux@70 to enable
1541 channel 6, and then the Commando to the mux@71 to enable
1544 After that, you can use the "normal" i2c commands as
1545 usual, to communicate with your I2C devices behind
1548 This option is actually implemented for the bitbanging
1549 algorithm in common/soft_i2c.c and for the Hardware I2C
1550 Bus on the MPC8260. But it should be not so difficult
1551 to add this option to other architectures.
1553 CONFIG_SOFT_I2C_READ_REPEATED_START
1555 defining this will force the i2c_read() function in
1556 the soft_i2c driver to perform an I2C repeated start
1557 between writing the address pointer and reading the
1558 data. If this define is omitted the default behaviour
1559 of doing a stop-start sequence will be used. Most I2C
1560 devices can use either method, but some require one or
1563 - SPI Support: CONFIG_SPI
1565 Enables SPI driver (so far only tested with
1566 SPI EEPROM, also an instance works with Crystal A/D and
1567 D/As on the SACSng board)
1571 Enables extended (16-bit) SPI EEPROM addressing.
1572 (symmetrical to CONFIG_I2C_X)
1576 Enables a software (bit-bang) SPI driver rather than
1577 using hardware support. This is a general purpose
1578 driver that only requires three general I/O port pins
1579 (two outputs, one input) to function. If this is
1580 defined, the board configuration must define several
1581 SPI configuration items (port pins to use, etc). For
1582 an example, see include/configs/sacsng.h.
1586 Enables a hardware SPI driver for general-purpose reads
1587 and writes. As with CONFIG_SOFT_SPI, the board configuration
1588 must define a list of chip-select function pointers.
1589 Currently supported on some MPC8xxx processors. For an
1590 example, see include/configs/mpc8349emds.h.
1594 Enables the driver for the SPI controllers on i.MX and MXC
1595 SoCs. Currently only i.MX31 is supported.
1597 - FPGA Support: CONFIG_FPGA
1599 Enables FPGA subsystem.
1601 CONFIG_FPGA_<vendor>
1603 Enables support for specific chip vendors.
1606 CONFIG_FPGA_<family>
1608 Enables support for FPGA family.
1609 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX)
1613 Specify the number of FPGA devices to support.
1615 CONFIG_SYS_FPGA_PROG_FEEDBACK
1617 Enable printing of hash marks during FPGA configuration.
1619 CONFIG_SYS_FPGA_CHECK_BUSY
1621 Enable checks on FPGA configuration interface busy
1622 status by the configuration function. This option
1623 will require a board or device specific function to
1628 If defined, a function that provides delays in the FPGA
1629 configuration driver.
1631 CONFIG_SYS_FPGA_CHECK_CTRLC
1632 Allow Control-C to interrupt FPGA configuration
1634 CONFIG_SYS_FPGA_CHECK_ERROR
1636 Check for configuration errors during FPGA bitfile
1637 loading. For example, abort during Virtex II
1638 configuration if the INIT_B line goes low (which
1639 indicated a CRC error).
1641 CONFIG_SYS_FPGA_WAIT_INIT
1643 Maximum time to wait for the INIT_B line to deassert
1644 after PROB_B has been deasserted during a Virtex II
1645 FPGA configuration sequence. The default time is 500
1648 CONFIG_SYS_FPGA_WAIT_BUSY
1650 Maximum time to wait for BUSY to deassert during
1651 Virtex II FPGA configuration. The default is 5 ms.
1653 CONFIG_SYS_FPGA_WAIT_CONFIG
1655 Time to wait after FPGA configuration. The default is
1658 - Configuration Management:
1661 If defined, this string will be added to the U-Boot
1662 version information (U_BOOT_VERSION)
1664 - Vendor Parameter Protection:
1666 U-Boot considers the values of the environment
1667 variables "serial#" (Board Serial Number) and
1668 "ethaddr" (Ethernet Address) to be parameters that
1669 are set once by the board vendor / manufacturer, and
1670 protects these variables from casual modification by
1671 the user. Once set, these variables are read-only,
1672 and write or delete attempts are rejected. You can
1673 change this behaviour:
1675 If CONFIG_ENV_OVERWRITE is #defined in your config
1676 file, the write protection for vendor parameters is
1677 completely disabled. Anybody can change or delete
1680 Alternatively, if you #define _both_ CONFIG_ETHADDR
1681 _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
1682 Ethernet address is installed in the environment,
1683 which can be changed exactly ONCE by the user. [The
1684 serial# is unaffected by this, i. e. it remains
1690 Define this variable to enable the reservation of
1691 "protected RAM", i. e. RAM which is not overwritten
1692 by U-Boot. Define CONFIG_PRAM to hold the number of
1693 kB you want to reserve for pRAM. You can overwrite
1694 this default value by defining an environment
1695 variable "pram" to the number of kB you want to
1696 reserve. Note that the board info structure will
1697 still show the full amount of RAM. If pRAM is
1698 reserved, a new environment variable "mem" will
1699 automatically be defined to hold the amount of
1700 remaining RAM in a form that can be passed as boot
1701 argument to Linux, for instance like that:
1703 setenv bootargs ... mem=\${mem}
1706 This way you can tell Linux not to use this memory,
1707 either, which results in a memory region that will
1708 not be affected by reboots.
1710 *WARNING* If your board configuration uses automatic
1711 detection of the RAM size, you must make sure that
1712 this memory test is non-destructive. So far, the
1713 following board configurations are known to be
1716 ETX094, IVMS8, IVML24, SPD8xx, TQM8xxL,
1717 HERMES, IP860, RPXlite, LWMON, LANTEC,
1718 PCU_E, FLAGADM, TQM8260
1723 Define this variable to stop the system in case of a
1724 fatal error, so that you have to reset it manually.
1725 This is probably NOT a good idea for an embedded
1726 system where you want the system to reboot
1727 automatically as fast as possible, but it may be
1728 useful during development since you can try to debug
1729 the conditions that lead to the situation.
1731 CONFIG_NET_RETRY_COUNT
1733 This variable defines the number of retries for
1734 network operations like ARP, RARP, TFTP, or BOOTP
1735 before giving up the operation. If not defined, a
1736 default value of 5 is used.
1740 Timeout waiting for an ARP reply in milliseconds.
1742 - Command Interpreter:
1743 CONFIG_AUTO_COMPLETE
1745 Enable auto completion of commands using TAB.
1747 Note that this feature has NOT been implemented yet
1748 for the "hush" shell.
1751 CONFIG_SYS_HUSH_PARSER
1753 Define this variable to enable the "hush" shell (from
1754 Busybox) as command line interpreter, thus enabling
1755 powerful command line syntax like
1756 if...then...else...fi conditionals or `&&' and '||'
1757 constructs ("shell scripts").
1759 If undefined, you get the old, much simpler behaviour
1760 with a somewhat smaller memory footprint.
1763 CONFIG_SYS_PROMPT_HUSH_PS2
1765 This defines the secondary prompt string, which is
1766 printed when the command interpreter needs more input
1767 to complete a command. Usually "> ".
1771 In the current implementation, the local variables
1772 space and global environment variables space are
1773 separated. Local variables are those you define by
1774 simply typing `name=value'. To access a local
1775 variable later on, you have write `$name' or
1776 `${name}'; to execute the contents of a variable
1777 directly type `$name' at the command prompt.
1779 Global environment variables are those you use
1780 setenv/printenv to work with. To run a command stored
1781 in such a variable, you need to use the run command,
1782 and you must not use the '$' sign to access them.
1784 To store commands and special characters in a
1785 variable, please use double quotation marks
1786 surrounding the whole text of the variable, instead
1787 of the backslashes before semicolons and special
1790 - Commandline Editing and History:
1791 CONFIG_CMDLINE_EDITING
1793 Enable editing and History functions for interactive
1794 commandline input operations
1796 - Default Environment:
1797 CONFIG_EXTRA_ENV_SETTINGS
1799 Define this to contain any number of null terminated
1800 strings (variable = value pairs) that will be part of
1801 the default environment compiled into the boot image.
1803 For example, place something like this in your
1804 board's config file:
1806 #define CONFIG_EXTRA_ENV_SETTINGS \
1810 Warning: This method is based on knowledge about the
1811 internal format how the environment is stored by the
1812 U-Boot code. This is NOT an official, exported
1813 interface! Although it is unlikely that this format
1814 will change soon, there is no guarantee either.
1815 You better know what you are doing here.
1817 Note: overly (ab)use of the default environment is
1818 discouraged. Make sure to check other ways to preset
1819 the environment like the "source" command or the
1822 - DataFlash Support:
1823 CONFIG_HAS_DATAFLASH
1825 Defining this option enables DataFlash features and
1826 allows to read/write in Dataflash via the standard
1829 - SystemACE Support:
1832 Adding this option adds support for Xilinx SystemACE
1833 chips attached via some sort of local bus. The address
1834 of the chip must also be defined in the
1835 CONFIG_SYS_SYSTEMACE_BASE macro. For example:
1837 #define CONFIG_SYSTEMACE
1838 #define CONFIG_SYS_SYSTEMACE_BASE 0xf0000000
1840 When SystemACE support is added, the "ace" device type
1841 becomes available to the fat commands, i.e. fatls.
1843 - TFTP Fixed UDP Port:
1846 If this is defined, the environment variable tftpsrcp
1847 is used to supply the TFTP UDP source port value.
1848 If tftpsrcp isn't defined, the normal pseudo-random port
1849 number generator is used.
1851 Also, the environment variable tftpdstp is used to supply
1852 the TFTP UDP destination port value. If tftpdstp isn't
1853 defined, the normal port 69 is used.
1855 The purpose for tftpsrcp is to allow a TFTP server to
1856 blindly start the TFTP transfer using the pre-configured
1857 target IP address and UDP port. This has the effect of
1858 "punching through" the (Windows XP) firewall, allowing
1859 the remainder of the TFTP transfer to proceed normally.
1860 A better solution is to properly configure the firewall,
1861 but sometimes that is not allowed.
1863 - Show boot progress:
1864 CONFIG_SHOW_BOOT_PROGRESS
1866 Defining this option allows to add some board-
1867 specific code (calling a user-provided function
1868 "show_boot_progress(int)") that enables you to show
1869 the system's boot progress on some display (for
1870 example, some LED's) on your board. At the moment,
1871 the following checkpoints are implemented:
1873 - Automatic software updates via TFTP server
1875 CONFIG_UPDATE_TFTP_CNT_MAX
1876 CONFIG_UPDATE_TFTP_MSEC_MAX
1878 These options enable and control the auto-update feature;
1879 for a more detailed description refer to doc/README.update.
1881 - MTD Support (mtdparts command, UBI support)
1884 Adds the MTD device infrastructure from the Linux kernel.
1885 Needed for mtdparts command support.
1887 CONFIG_MTD_PARTITIONS
1889 Adds the MTD partitioning infrastructure from the Linux
1890 kernel. Needed for UBI support.
1892 Legacy uImage format:
1895 1 common/cmd_bootm.c before attempting to boot an image
1896 -1 common/cmd_bootm.c Image header has bad magic number
1897 2 common/cmd_bootm.c Image header has correct magic number
1898 -2 common/cmd_bootm.c Image header has bad checksum
1899 3 common/cmd_bootm.c Image header has correct checksum
1900 -3 common/cmd_bootm.c Image data has bad checksum
1901 4 common/cmd_bootm.c Image data has correct checksum
1902 -4 common/cmd_bootm.c Image is for unsupported architecture
1903 5 common/cmd_bootm.c Architecture check OK
1904 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi)
1905 6 common/cmd_bootm.c Image Type check OK
1906 -6 common/cmd_bootm.c gunzip uncompression error
1907 -7 common/cmd_bootm.c Unimplemented compression type
1908 7 common/cmd_bootm.c Uncompression OK
1909 8 common/cmd_bootm.c No uncompress/copy overwrite error
1910 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX)
1912 9 common/image.c Start initial ramdisk verification
1913 -10 common/image.c Ramdisk header has bad magic number
1914 -11 common/image.c Ramdisk header has bad checksum
1915 10 common/image.c Ramdisk header is OK
1916 -12 common/image.c Ramdisk data has bad checksum
1917 11 common/image.c Ramdisk data has correct checksum
1918 12 common/image.c Ramdisk verification complete, start loading
1919 -13 common/image.c Wrong Image Type (not PPC Linux ramdisk)
1920 13 common/image.c Start multifile image verification
1921 14 common/image.c No initial ramdisk, no multifile, continue.
1923 15 lib_<arch>/bootm.c All preparation done, transferring control to OS
1925 -30 lib_ppc/board.c Fatal error, hang the system
1926 -31 post/post.c POST test failed, detected by post_output_backlog()
1927 -32 post/post.c POST test failed, detected by post_run_single()
1929 34 common/cmd_doc.c before loading a Image from a DOC device
1930 -35 common/cmd_doc.c Bad usage of "doc" command
1931 35 common/cmd_doc.c correct usage of "doc" command
1932 -36 common/cmd_doc.c No boot device
1933 36 common/cmd_doc.c correct boot device
1934 -37 common/cmd_doc.c Unknown Chip ID on boot device
1935 37 common/cmd_doc.c correct chip ID found, device available
1936 -38 common/cmd_doc.c Read Error on boot device
1937 38 common/cmd_doc.c reading Image header from DOC device OK
1938 -39 common/cmd_doc.c Image header has bad magic number
1939 39 common/cmd_doc.c Image header has correct magic number
1940 -40 common/cmd_doc.c Error reading Image from DOC device
1941 40 common/cmd_doc.c Image header has correct magic number
1942 41 common/cmd_ide.c before loading a Image from a IDE device
1943 -42 common/cmd_ide.c Bad usage of "ide" command
1944 42 common/cmd_ide.c correct usage of "ide" command
1945 -43 common/cmd_ide.c No boot device
1946 43 common/cmd_ide.c boot device found
1947 -44 common/cmd_ide.c Device not available
1948 44 common/cmd_ide.c Device available
1949 -45 common/cmd_ide.c wrong partition selected
1950 45 common/cmd_ide.c partition selected
1951 -46 common/cmd_ide.c Unknown partition table
1952 46 common/cmd_ide.c valid partition table found
1953 -47 common/cmd_ide.c Invalid partition type
1954 47 common/cmd_ide.c correct partition type
1955 -48 common/cmd_ide.c Error reading Image Header on boot device
1956 48 common/cmd_ide.c reading Image Header from IDE device OK
1957 -49 common/cmd_ide.c Image header has bad magic number
1958 49 common/cmd_ide.c Image header has correct magic number
1959 -50 common/cmd_ide.c Image header has bad checksum
1960 50 common/cmd_ide.c Image header has correct checksum
1961 -51 common/cmd_ide.c Error reading Image from IDE device
1962 51 common/cmd_ide.c reading Image from IDE device OK
1963 52 common/cmd_nand.c before loading a Image from a NAND device
1964 -53 common/cmd_nand.c Bad usage of "nand" command
1965 53 common/cmd_nand.c correct usage of "nand" command
1966 -54 common/cmd_nand.c No boot device
1967 54 common/cmd_nand.c boot device found
1968 -55 common/cmd_nand.c Unknown Chip ID on boot device
1969 55 common/cmd_nand.c correct chip ID found, device available
1970 -56 common/cmd_nand.c Error reading Image Header on boot device
1971 56 common/cmd_nand.c reading Image Header from NAND device OK
1972 -57 common/cmd_nand.c Image header has bad magic number
1973 57 common/cmd_nand.c Image header has correct magic number
1974 -58 common/cmd_nand.c Error reading Image from NAND device
1975 58 common/cmd_nand.c reading Image from NAND device OK
1977 -60 common/env_common.c Environment has a bad CRC, using default
1979 64 net/eth.c starting with Ethernet configuration.
1980 -64 net/eth.c no Ethernet found.
1981 65 net/eth.c Ethernet found.
1983 -80 common/cmd_net.c usage wrong
1984 80 common/cmd_net.c before calling NetLoop()
1985 -81 common/cmd_net.c some error in NetLoop() occurred
1986 81 common/cmd_net.c NetLoop() back without error
1987 -82 common/cmd_net.c size == 0 (File with size 0 loaded)
1988 82 common/cmd_net.c trying automatic boot
1989 83 common/cmd_net.c running "source" command
1990 -83 common/cmd_net.c some error in automatic boot or "source" command
1991 84 common/cmd_net.c end without errors
1996 100 common/cmd_bootm.c Kernel FIT Image has correct format
1997 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format
1998 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration
1999 -101 common/cmd_bootm.c Can't get configuration for kernel subimage
2000 102 common/cmd_bootm.c Kernel unit name specified
2001 -103 common/cmd_bootm.c Can't get kernel subimage node offset
2002 103 common/cmd_bootm.c Found configuration node
2003 104 common/cmd_bootm.c Got kernel subimage node offset
2004 -104 common/cmd_bootm.c Kernel subimage hash verification failed
2005 105 common/cmd_bootm.c Kernel subimage hash verification OK
2006 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture
2007 106 common/cmd_bootm.c Architecture check OK
2008 -106 common/cmd_bootm.c Kernel subimage has wrong type
2009 107 common/cmd_bootm.c Kernel subimage type OK
2010 -107 common/cmd_bootm.c Can't get kernel subimage data/size
2011 108 common/cmd_bootm.c Got kernel subimage data/size
2012 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT)
2013 -109 common/cmd_bootm.c Can't get kernel subimage type
2014 -110 common/cmd_bootm.c Can't get kernel subimage comp
2015 -111 common/cmd_bootm.c Can't get kernel subimage os
2016 -112 common/cmd_bootm.c Can't get kernel subimage load address
2017 -113 common/cmd_bootm.c Image uncompress/copy overwrite error
2019 120 common/image.c Start initial ramdisk verification
2020 -120 common/image.c Ramdisk FIT image has incorrect format
2021 121 common/image.c Ramdisk FIT image has correct format
2022 122 common/image.c No ramdisk subimage unit name, using configuration
2023 -122 common/image.c Can't get configuration for ramdisk subimage
2024 123 common/image.c Ramdisk unit name specified
2025 -124 common/image.c Can't get ramdisk subimage node offset
2026 125 common/image.c Got ramdisk subimage node offset
2027 -125 common/image.c Ramdisk subimage hash verification failed
2028 126 common/image.c Ramdisk subimage hash verification OK
2029 -126 common/image.c Ramdisk subimage for unsupported architecture
2030 127 common/image.c Architecture check OK
2031 -127 common/image.c Can't get ramdisk subimage data/size
2032 128 common/image.c Got ramdisk subimage data/size
2033 129 common/image.c Can't get ramdisk load address
2034 -129 common/image.c Got ramdisk load address
2036 -130 common/cmd_doc.c Incorrect FIT image format
2037 131 common/cmd_doc.c FIT image format OK
2039 -140 common/cmd_ide.c Incorrect FIT image format
2040 141 common/cmd_ide.c FIT image format OK
2042 -150 common/cmd_nand.c Incorrect FIT image format
2043 151 common/cmd_nand.c FIT image format OK
2049 [so far only for SMDK2400 and TRAB boards]
2051 - Modem support enable:
2052 CONFIG_MODEM_SUPPORT
2054 - RTS/CTS Flow control enable:
2057 - Modem debug support:
2058 CONFIG_MODEM_SUPPORT_DEBUG
2060 Enables debugging stuff (char screen[1024], dbg())
2061 for modem support. Useful only with BDI2000.
2063 - Interrupt support (PPC):
2065 There are common interrupt_init() and timer_interrupt()
2066 for all PPC archs. interrupt_init() calls interrupt_init_cpu()
2067 for CPU specific initialization. interrupt_init_cpu()
2068 should set decrementer_count to appropriate value. If
2069 CPU resets decrementer automatically after interrupt
2070 (ppc4xx) it should set decrementer_count to zero.
2071 timer_interrupt() calls timer_interrupt_cpu() for CPU
2072 specific handling. If board has watchdog / status_led
2073 / other_activity_monitor it works automatically from
2074 general timer_interrupt().
2078 In the target system modem support is enabled when a
2079 specific key (key combination) is pressed during
2080 power-on. Otherwise U-Boot will boot normally
2081 (autoboot). The key_pressed() function is called from
2082 board_init(). Currently key_pressed() is a dummy
2083 function, returning 1 and thus enabling modem
2086 If there are no modem init strings in the
2087 environment, U-Boot proceed to autoboot; the
2088 previous output (banner, info printfs) will be
2091 See also: doc/README.Modem
2094 Configuration Settings:
2095 -----------------------
2097 - CONFIG_SYS_LONGHELP: Defined when you want long help messages included;
2098 undefine this when you're short of memory.
2100 - CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default
2101 width of the commands listed in the 'help' command output.
2103 - CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to
2104 prompt for user input.
2106 - CONFIG_SYS_CBSIZE: Buffer size for input from the Console
2108 - CONFIG_SYS_PBSIZE: Buffer size for Console output
2110 - CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands
2112 - CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to
2113 the application (usually a Linux kernel) when it is
2116 - CONFIG_SYS_BAUDRATE_TABLE:
2117 List of legal baudrate settings for this board.
2119 - CONFIG_SYS_CONSOLE_INFO_QUIET
2120 Suppress display of console information at boot.
2122 - CONFIG_SYS_CONSOLE_IS_IN_ENV
2123 If the board specific function
2124 extern int overwrite_console (void);
2125 returns 1, the stdin, stderr and stdout are switched to the
2126 serial port, else the settings in the environment are used.
2128 - CONFIG_SYS_CONSOLE_OVERWRITE_ROUTINE
2129 Enable the call to overwrite_console().
2131 - CONFIG_SYS_CONSOLE_ENV_OVERWRITE
2132 Enable overwrite of previous console environment settings.
2134 - CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END:
2135 Begin and End addresses of the area used by the
2138 - CONFIG_SYS_ALT_MEMTEST:
2139 Enable an alternate, more extensive memory test.
2141 - CONFIG_SYS_MEMTEST_SCRATCH:
2142 Scratch address used by the alternate memory test
2143 You only need to set this if address zero isn't writeable
2145 - CONFIG_SYS_MEM_TOP_HIDE (PPC only):
2146 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header,
2147 this specified memory area will get subtracted from the top
2148 (end) of RAM and won't get "touched" at all by U-Boot. By
2149 fixing up gd->ram_size the Linux kernel should gets passed
2150 the now "corrected" memory size and won't touch it either.
2151 This should work for arch/ppc and arch/powerpc. Only Linux
2152 board ports in arch/powerpc with bootwrapper support that
2153 recalculate the memory size from the SDRAM controller setup
2154 will have to get fixed in Linux additionally.
2156 This option can be used as a workaround for the 440EPx/GRx
2157 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't
2160 WARNING: Please make sure that this value is a multiple of
2161 the Linux page size (normally 4k). If this is not the case,
2162 then the end address of the Linux memory will be located at a
2163 non page size aligned address and this could cause major
2166 - CONFIG_SYS_TFTP_LOADADDR:
2167 Default load address for network file downloads
2169 - CONFIG_SYS_LOADS_BAUD_CHANGE:
2170 Enable temporary baudrate change while serial download
2172 - CONFIG_SYS_SDRAM_BASE:
2173 Physical start address of SDRAM. _Must_ be 0 here.
2175 - CONFIG_SYS_MBIO_BASE:
2176 Physical start address of Motherboard I/O (if using a
2179 - CONFIG_SYS_FLASH_BASE:
2180 Physical start address of Flash memory.
2182 - CONFIG_SYS_MONITOR_BASE:
2183 Physical start address of boot monitor code (set by
2184 make config files to be same as the text base address
2185 (TEXT_BASE) used when linking) - same as
2186 CONFIG_SYS_FLASH_BASE when booting from flash.
2188 - CONFIG_SYS_MONITOR_LEN:
2189 Size of memory reserved for monitor code, used to
2190 determine _at_compile_time_ (!) if the environment is
2191 embedded within the U-Boot image, or in a separate
2194 - CONFIG_SYS_MALLOC_LEN:
2195 Size of DRAM reserved for malloc() use.
2197 - CONFIG_SYS_BOOTM_LEN:
2198 Normally compressed uImages are limited to an
2199 uncompressed size of 8 MBytes. If this is not enough,
2200 you can define CONFIG_SYS_BOOTM_LEN in your board config file
2201 to adjust this setting to your needs.
2203 - CONFIG_SYS_BOOTMAPSZ:
2204 Maximum size of memory mapped by the startup code of
2205 the Linux kernel; all data that must be processed by
2206 the Linux kernel (bd_info, boot arguments, FDT blob if
2207 used) must be put below this limit, unless "bootm_low"
2208 enviroment variable is defined and non-zero. In such case
2209 all data for the Linux kernel must be between "bootm_low"
2210 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ.
2212 - CONFIG_SYS_MAX_FLASH_BANKS:
2213 Max number of Flash memory banks
2215 - CONFIG_SYS_MAX_FLASH_SECT:
2216 Max number of sectors on a Flash chip
2218 - CONFIG_SYS_FLASH_ERASE_TOUT:
2219 Timeout for Flash erase operations (in ms)
2221 - CONFIG_SYS_FLASH_WRITE_TOUT:
2222 Timeout for Flash write operations (in ms)
2224 - CONFIG_SYS_FLASH_LOCK_TOUT
2225 Timeout for Flash set sector lock bit operation (in ms)
2227 - CONFIG_SYS_FLASH_UNLOCK_TOUT
2228 Timeout for Flash clear lock bits operation (in ms)
2230 - CONFIG_SYS_FLASH_PROTECTION
2231 If defined, hardware flash sectors protection is used
2232 instead of U-Boot software protection.
2234 - CONFIG_SYS_DIRECT_FLASH_TFTP:
2236 Enable TFTP transfers directly to flash memory;
2237 without this option such a download has to be
2238 performed in two steps: (1) download to RAM, and (2)
2239 copy from RAM to flash.
2241 The two-step approach is usually more reliable, since
2242 you can check if the download worked before you erase
2243 the flash, but in some situations (when system RAM is
2244 too limited to allow for a temporary copy of the
2245 downloaded image) this option may be very useful.
2247 - CONFIG_SYS_FLASH_CFI:
2248 Define if the flash driver uses extra elements in the
2249 common flash structure for storing flash geometry.
2251 - CONFIG_FLASH_CFI_DRIVER
2252 This option also enables the building of the cfi_flash driver
2253 in the drivers directory
2255 - CONFIG_FLASH_CFI_MTD
2256 This option enables the building of the cfi_mtd driver
2257 in the drivers directory. The driver exports CFI flash
2260 - CONFIG_SYS_FLASH_USE_BUFFER_WRITE
2261 Use buffered writes to flash.
2263 - CONFIG_FLASH_SPANSION_S29WS_N
2264 s29ws-n MirrorBit flash has non-standard addresses for buffered
2267 - CONFIG_SYS_FLASH_QUIET_TEST
2268 If this option is defined, the common CFI flash doesn't
2269 print it's warning upon not recognized FLASH banks. This
2270 is useful, if some of the configured banks are only
2271 optionally available.
2273 - CONFIG_FLASH_SHOW_PROGRESS
2274 If defined (must be an integer), print out countdown
2275 digits and dots. Recommended value: 45 (9..1) for 80
2276 column displays, 15 (3..1) for 40 column displays.
2278 - CONFIG_SYS_RX_ETH_BUFFER:
2279 Defines the number of Ethernet receive buffers. On some
2280 Ethernet controllers it is recommended to set this value
2281 to 8 or even higher (EEPRO100 or 405 EMAC), since all
2282 buffers can be full shortly after enabling the interface
2283 on high Ethernet traffic.
2284 Defaults to 4 if not defined.
2286 The following definitions that deal with the placement and management
2287 of environment data (variable area); in general, we support the
2288 following configurations:
2290 - CONFIG_ENV_IS_IN_FLASH:
2292 Define this if the environment is in flash memory.
2294 a) The environment occupies one whole flash sector, which is
2295 "embedded" in the text segment with the U-Boot code. This
2296 happens usually with "bottom boot sector" or "top boot
2297 sector" type flash chips, which have several smaller
2298 sectors at the start or the end. For instance, such a
2299 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In
2300 such a case you would place the environment in one of the
2301 4 kB sectors - with U-Boot code before and after it. With
2302 "top boot sector" type flash chips, you would put the
2303 environment in one of the last sectors, leaving a gap
2304 between U-Boot and the environment.
2306 - CONFIG_ENV_OFFSET:
2308 Offset of environment data (variable area) to the
2309 beginning of flash memory; for instance, with bottom boot
2310 type flash chips the second sector can be used: the offset
2311 for this sector is given here.
2313 CONFIG_ENV_OFFSET is used relative to CONFIG_SYS_FLASH_BASE.
2317 This is just another way to specify the start address of
2318 the flash sector containing the environment (instead of
2321 - CONFIG_ENV_SECT_SIZE:
2323 Size of the sector containing the environment.
2326 b) Sometimes flash chips have few, equal sized, BIG sectors.
2327 In such a case you don't want to spend a whole sector for
2332 If you use this in combination with CONFIG_ENV_IS_IN_FLASH
2333 and CONFIG_ENV_SECT_SIZE, you can specify to use only a part
2334 of this flash sector for the environment. This saves
2335 memory for the RAM copy of the environment.
2337 It may also save flash memory if you decide to use this
2338 when your environment is "embedded" within U-Boot code,
2339 since then the remainder of the flash sector could be used
2340 for U-Boot code. It should be pointed out that this is
2341 STRONGLY DISCOURAGED from a robustness point of view:
2342 updating the environment in flash makes it always
2343 necessary to erase the WHOLE sector. If something goes
2344 wrong before the contents has been restored from a copy in
2345 RAM, your target system will be dead.
2347 - CONFIG_ENV_ADDR_REDUND
2348 CONFIG_ENV_SIZE_REDUND
2350 These settings describe a second storage area used to hold
2351 a redundant copy of the environment data, so that there is
2352 a valid backup copy in case there is a power failure during
2353 a "saveenv" operation.
2355 BE CAREFUL! Any changes to the flash layout, and some changes to the
2356 source code will make it necessary to adapt <board>/u-boot.lds*
2360 - CONFIG_ENV_IS_IN_NVRAM:
2362 Define this if you have some non-volatile memory device
2363 (NVRAM, battery buffered SRAM) which you want to use for the
2369 These two #defines are used to determine the memory area you
2370 want to use for environment. It is assumed that this memory
2371 can just be read and written to, without any special
2374 BE CAREFUL! The first access to the environment happens quite early
2375 in U-Boot initalization (when we try to get the setting of for the
2376 console baudrate). You *MUST* have mapped your NVRAM area then, or
2379 Please note that even with NVRAM we still use a copy of the
2380 environment in RAM: we could work on NVRAM directly, but we want to
2381 keep settings there always unmodified except somebody uses "saveenv"
2382 to save the current settings.
2385 - CONFIG_ENV_IS_IN_EEPROM:
2387 Use this if you have an EEPROM or similar serial access
2388 device and a driver for it.
2390 - CONFIG_ENV_OFFSET:
2393 These two #defines specify the offset and size of the
2394 environment area within the total memory of your EEPROM.
2396 - CONFIG_SYS_I2C_EEPROM_ADDR:
2397 If defined, specified the chip address of the EEPROM device.
2398 The default address is zero.
2400 - CONFIG_SYS_EEPROM_PAGE_WRITE_BITS:
2401 If defined, the number of bits used to address bytes in a
2402 single page in the EEPROM device. A 64 byte page, for example
2403 would require six bits.
2405 - CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS:
2406 If defined, the number of milliseconds to delay between
2407 page writes. The default is zero milliseconds.
2409 - CONFIG_SYS_I2C_EEPROM_ADDR_LEN:
2410 The length in bytes of the EEPROM memory array address. Note
2411 that this is NOT the chip address length!
2413 - CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW:
2414 EEPROM chips that implement "address overflow" are ones
2415 like Catalyst 24WC04/08/16 which has 9/10/11 bits of
2416 address and the extra bits end up in the "chip address" bit
2417 slots. This makes a 24WC08 (1Kbyte) chip look like four 256
2420 Note that we consider the length of the address field to
2421 still be one byte because the extra address bits are hidden
2422 in the chip address.
2424 - CONFIG_SYS_EEPROM_SIZE:
2425 The size in bytes of the EEPROM device.
2428 - CONFIG_ENV_IS_IN_DATAFLASH:
2430 Define this if you have a DataFlash memory device which you
2431 want to use for the environment.
2433 - CONFIG_ENV_OFFSET:
2437 These three #defines specify the offset and size of the
2438 environment area within the total memory of your DataFlash placed
2439 at the specified address.
2441 - CONFIG_ENV_IS_IN_NAND:
2443 Define this if you have a NAND device which you want to use
2444 for the environment.
2446 - CONFIG_ENV_OFFSET:
2449 These two #defines specify the offset and size of the environment
2450 area within the first NAND device.
2452 - CONFIG_ENV_OFFSET_REDUND
2454 This setting describes a second storage area of CONFIG_ENV_SIZE
2455 size used to hold a redundant copy of the environment data,
2456 so that there is a valid backup copy in case there is a
2457 power failure during a "saveenv" operation.
2459 Note: CONFIG_ENV_OFFSET and CONFIG_ENV_OFFSET_REDUND must be aligned
2460 to a block boundary, and CONFIG_ENV_SIZE must be a multiple of
2461 the NAND devices block size.
2463 - CONFIG_NAND_ENV_DST
2465 Defines address in RAM to which the nand_spl code should copy the
2466 environment. If redundant environment is used, it will be copied to
2467 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE.
2469 - CONFIG_SYS_SPI_INIT_OFFSET
2471 Defines offset to the initial SPI buffer area in DPRAM. The
2472 area is used at an early stage (ROM part) if the environment
2473 is configured to reside in the SPI EEPROM: We need a 520 byte
2474 scratch DPRAM area. It is used between the two initialization
2475 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems
2476 to be a good choice since it makes it far enough from the
2477 start of the data area as well as from the stack pointer.
2479 Please note that the environment is read-only until the monitor
2480 has been relocated to RAM and a RAM copy of the environment has been
2481 created; also, when using EEPROM you will have to use getenv_r()
2482 until then to read environment variables.
2484 The environment is protected by a CRC32 checksum. Before the monitor
2485 is relocated into RAM, as a result of a bad CRC you will be working
2486 with the compiled-in default environment - *silently*!!! [This is
2487 necessary, because the first environment variable we need is the
2488 "baudrate" setting for the console - if we have a bad CRC, we don't
2489 have any device yet where we could complain.]
2491 Note: once the monitor has been relocated, then it will complain if
2492 the default environment is used; a new CRC is computed as soon as you
2493 use the "saveenv" command to store a valid environment.
2495 - CONFIG_SYS_FAULT_ECHO_LINK_DOWN:
2496 Echo the inverted Ethernet link state to the fault LED.
2498 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR
2499 also needs to be defined.
2501 - CONFIG_SYS_FAULT_MII_ADDR:
2502 MII address of the PHY to check for the Ethernet link state.
2504 - CONFIG_SYS_64BIT_VSPRINTF:
2505 Makes vsprintf (and all *printf functions) support printing
2506 of 64bit values by using the L quantifier
2508 - CONFIG_SYS_64BIT_STRTOUL:
2509 Adds simple_strtoull that returns a 64bit value
2511 - CONFIG_NS16550_MIN_FUNCTIONS:
2512 Define this if you desire to only have use of the NS16550_init
2513 and NS16550_putc functions for the serial driver located at
2514 drivers/serial/ns16550.c. This option is useful for saving
2515 space for already greatly restricted images, including but not
2516 limited to NAND_SPL configurations.
2518 Low Level (hardware related) configuration options:
2519 ---------------------------------------------------
2521 - CONFIG_SYS_CACHELINE_SIZE:
2522 Cache Line Size of the CPU.
2524 - CONFIG_SYS_DEFAULT_IMMR:
2525 Default address of the IMMR after system reset.
2527 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU,
2528 and RPXsuper) to be able to adjust the position of
2529 the IMMR register after a reset.
2531 - Floppy Disk Support:
2532 CONFIG_SYS_FDC_DRIVE_NUMBER
2534 the default drive number (default value 0)
2536 CONFIG_SYS_ISA_IO_STRIDE
2538 defines the spacing between FDC chipset registers
2541 CONFIG_SYS_ISA_IO_OFFSET
2543 defines the offset of register from address. It
2544 depends on which part of the data bus is connected to
2545 the FDC chipset. (default value 0)
2547 If CONFIG_SYS_ISA_IO_STRIDE CONFIG_SYS_ISA_IO_OFFSET and
2548 CONFIG_SYS_FDC_DRIVE_NUMBER are undefined, they take their
2551 if CONFIG_SYS_FDC_HW_INIT is defined, then the function
2552 fdc_hw_init() is called at the beginning of the FDC
2553 setup. fdc_hw_init() must be provided by the board
2554 source code. It is used to make hardware dependant
2557 - CONFIG_SYS_IMMR: Physical address of the Internal Memory.
2558 DO NOT CHANGE unless you know exactly what you're
2559 doing! (11-4) [MPC8xx/82xx systems only]
2561 - CONFIG_SYS_INIT_RAM_ADDR:
2563 Start address of memory area that can be used for
2564 initial data and stack; please note that this must be
2565 writable memory that is working WITHOUT special
2566 initialization, i. e. you CANNOT use normal RAM which
2567 will become available only after programming the
2568 memory controller and running certain initialization
2571 U-Boot uses the following memory types:
2572 - MPC8xx and MPC8260: IMMR (internal memory of the CPU)
2573 - MPC824X: data cache
2574 - PPC4xx: data cache
2576 - CONFIG_SYS_GBL_DATA_OFFSET:
2578 Offset of the initial data structure in the memory
2579 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually
2580 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial
2581 data is located at the end of the available space
2582 (sometimes written as (CONFIG_SYS_INIT_RAM_END -
2583 CONFIG_SYS_INIT_DATA_SIZE), and the initial stack is just
2584 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR +
2585 CONFIG_SYS_GBL_DATA_OFFSET) downward.
2588 On the MPC824X (or other systems that use the data
2589 cache for initial memory) the address chosen for
2590 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must
2591 point to an otherwise UNUSED address space between
2592 the top of RAM and the start of the PCI space.
2594 - CONFIG_SYS_SIUMCR: SIU Module Configuration (11-6)
2596 - CONFIG_SYS_SYPCR: System Protection Control (11-9)
2598 - CONFIG_SYS_TBSCR: Time Base Status and Control (11-26)
2600 - CONFIG_SYS_PISCR: Periodic Interrupt Status and Control (11-31)
2602 - CONFIG_SYS_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30)
2604 - CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27)
2606 - CONFIG_SYS_OR_TIMING_SDRAM:
2609 - CONFIG_SYS_MAMR_PTA:
2610 periodic timer for refresh
2612 - CONFIG_SYS_DER: Debug Event Register (37-47)
2614 - FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM,
2615 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP,
2616 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM,
2617 CONFIG_SYS_BR1_PRELIM:
2618 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
2620 - SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
2621 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM,
2622 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM:
2623 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
2625 - CONFIG_SYS_MAMR_PTA, CONFIG_SYS_MPTPR_2BK_4K, CONFIG_SYS_MPTPR_1BK_4K, CONFIG_SYS_MPTPR_2BK_8K,
2626 CONFIG_SYS_MPTPR_1BK_8K, CONFIG_SYS_MAMR_8COL, CONFIG_SYS_MAMR_9COL:
2627 Machine Mode Register and Memory Periodic Timer
2628 Prescaler definitions (SDRAM timing)
2630 - CONFIG_SYS_I2C_UCODE_PATCH, CONFIG_SYS_I2C_DPMEM_OFFSET [0x1FC0]:
2631 enable I2C microcode relocation patch (MPC8xx);
2632 define relocation offset in DPRAM [DSP2]
2634 - CONFIG_SYS_SMC_UCODE_PATCH, CONFIG_SYS_SMC_DPMEM_OFFSET [0x1FC0]:
2635 enable SMC microcode relocation patch (MPC8xx);
2636 define relocation offset in DPRAM [SMC1]
2638 - CONFIG_SYS_SPI_UCODE_PATCH, CONFIG_SYS_SPI_DPMEM_OFFSET [0x1FC0]:
2639 enable SPI microcode relocation patch (MPC8xx);
2640 define relocation offset in DPRAM [SCC4]
2642 - CONFIG_SYS_USE_OSCCLK:
2643 Use OSCM clock mode on MBX8xx board. Be careful,
2644 wrong setting might damage your board. Read
2645 doc/README.MBX before setting this variable!
2647 - CONFIG_SYS_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only)
2648 Offset of the bootmode word in DPRAM used by post
2649 (Power On Self Tests). This definition overrides
2650 #define'd default value in commproc.h resp.
2653 - CONFIG_SYS_PCI_SLV_MEM_LOCAL, CONFIG_SYS_PCI_SLV_MEM_BUS, CONFIG_SYS_PICMR0_MASK_ATTRIB,
2654 CONFIG_SYS_PCI_MSTR0_LOCAL, CONFIG_SYS_PCIMSK0_MASK, CONFIG_SYS_PCI_MSTR1_LOCAL,
2655 CONFIG_SYS_PCIMSK1_MASK, CONFIG_SYS_PCI_MSTR_MEM_LOCAL, CONFIG_SYS_PCI_MSTR_MEM_BUS,
2656 CONFIG_SYS_CPU_PCI_MEM_START, CONFIG_SYS_PCI_MSTR_MEM_SIZE, CONFIG_SYS_POCMR0_MASK_ATTRIB,
2657 CONFIG_SYS_PCI_MSTR_MEMIO_LOCAL, CONFIG_SYS_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START,
2658 CONFIG_SYS_PCI_MSTR_MEMIO_SIZE, CONFIG_SYS_POCMR1_MASK_ATTRIB, CONFIG_SYS_PCI_MSTR_IO_LOCAL,
2659 CONFIG_SYS_PCI_MSTR_IO_BUS, CONFIG_SYS_CPU_PCI_IO_START, CONFIG_SYS_PCI_MSTR_IO_SIZE,
2660 CONFIG_SYS_POCMR2_MASK_ATTRIB: (MPC826x only)
2661 Overrides the default PCI memory map in cpu/mpc8260/pci.c if set.
2663 - CONFIG_PCI_DISABLE_PCIE:
2664 Disable PCI-Express on systems where it is supported but not
2668 Get DDR timing information from an I2C EEPROM. Common
2669 with pluggable memory modules such as SODIMMs
2672 I2C address of the SPD EEPROM
2674 - CONFIG_SYS_SPD_BUS_NUM
2675 If SPD EEPROM is on an I2C bus other than the first
2676 one, specify here. Note that the value must resolve
2677 to something your driver can deal with.
2679 - CONFIG_SYS_83XX_DDR_USES_CS0
2680 Only for 83xx systems. If specified, then DDR should
2681 be configured using CS0 and CS1 instead of CS2 and CS3.
2683 - CONFIG_ETHER_ON_FEC[12]
2684 Define to enable FEC[12] on a 8xx series processor.
2686 - CONFIG_FEC[12]_PHY
2687 Define to the hardcoded PHY address which corresponds
2688 to the given FEC; i. e.
2689 #define CONFIG_FEC1_PHY 4
2690 means that the PHY with address 4 is connected to FEC1
2692 When set to -1, means to probe for first available.
2694 - CONFIG_FEC[12]_PHY_NORXERR
2695 The PHY does not have a RXERR line (RMII only).
2696 (so program the FEC to ignore it).
2699 Enable RMII mode for all FECs.
2700 Note that this is a global option, we can't
2701 have one FEC in standard MII mode and another in RMII mode.
2703 - CONFIG_CRC32_VERIFY
2704 Add a verify option to the crc32 command.
2707 => crc32 -v <address> <count> <crc32>
2709 Where address/count indicate a memory area
2710 and crc32 is the correct crc32 which the
2714 Add the "loopw" memory command. This only takes effect if
2715 the memory commands are activated globally (CONFIG_CMD_MEM).
2718 Add the "mdc" and "mwc" memory commands. These are cyclic
2723 This command will print 4 bytes (10,11,12,13) each 500 ms.
2725 => mwc.l 100 12345678 10
2726 This command will write 12345678 to address 100 all 10 ms.
2728 This only takes effect if the memory commands are activated
2729 globally (CONFIG_CMD_MEM).
2731 - CONFIG_SKIP_LOWLEVEL_INIT
2732 - CONFIG_SKIP_RELOCATE_UBOOT
2734 [ARM only] If these variables are defined, then
2735 certain low level initializations (like setting up
2736 the memory controller) are omitted and/or U-Boot does
2737 not relocate itself into RAM.
2738 Normally these variables MUST NOT be defined. The
2739 only exception is when U-Boot is loaded (to RAM) by
2740 some other boot loader or by a debugger which
2741 performs these initializations itself.
2745 Modifies the behaviour of start.S when compiling a loader
2746 that is executed before the actual U-Boot. E.g. when
2747 compiling a NAND SPL.
2749 Building the Software:
2750 ======================
2752 Building U-Boot has been tested in several native build environments
2753 and in many different cross environments. Of course we cannot support
2754 all possibly existing versions of cross development tools in all
2755 (potentially obsolete) versions. In case of tool chain problems we
2756 recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK)
2757 which is extensively used to build and test U-Boot.
2759 If you are not using a native environment, it is assumed that you
2760 have GNU cross compiling tools available in your path. In this case,
2761 you must set the environment variable CROSS_COMPILE in your shell.
2762 Note that no changes to the Makefile or any other source files are
2763 necessary. For example using the ELDK on a 4xx CPU, please enter:
2765 $ CROSS_COMPILE=ppc_4xx-
2766 $ export CROSS_COMPILE
2768 Note: If you wish to generate Windows versions of the utilities in
2769 the tools directory you can use the MinGW toolchain
2770 (http://www.mingw.org). Set your HOST tools to the MinGW
2771 toolchain and execute 'make tools'. For example:
2773 $ make HOSTCC=i586-mingw32msvc-gcc HOSTSTRIP=i586-mingw32msvc-strip tools
2775 Binaries such as tools/mkimage.exe will be created which can
2776 be executed on computers running Windows.
2778 U-Boot is intended to be simple to build. After installing the
2779 sources you must configure U-Boot for one specific board type. This
2784 where "NAME_config" is the name of one of the existing configu-
2785 rations; see the main Makefile for supported names.
2787 Note: for some board special configuration names may exist; check if
2788 additional information is available from the board vendor; for
2789 instance, the TQM823L systems are available without (standard)
2790 or with LCD support. You can select such additional "features"
2791 when choosing the configuration, i. e.
2794 - will configure for a plain TQM823L, i. e. no LCD support
2796 make TQM823L_LCD_config
2797 - will configure for a TQM823L with U-Boot console on LCD
2802 Finally, type "make all", and you should get some working U-Boot
2803 images ready for download to / installation on your system:
2805 - "u-boot.bin" is a raw binary image
2806 - "u-boot" is an image in ELF binary format
2807 - "u-boot.srec" is in Motorola S-Record format
2809 By default the build is performed locally and the objects are saved
2810 in the source directory. One of the two methods can be used to change
2811 this behavior and build U-Boot to some external directory:
2813 1. Add O= to the make command line invocations:
2815 make O=/tmp/build distclean
2816 make O=/tmp/build NAME_config
2817 make O=/tmp/build all
2819 2. Set environment variable BUILD_DIR to point to the desired location:
2821 export BUILD_DIR=/tmp/build
2826 Note that the command line "O=" setting overrides the BUILD_DIR environment
2830 Please be aware that the Makefiles assume you are using GNU make, so
2831 for instance on NetBSD you might need to use "gmake" instead of
2835 If the system board that you have is not listed, then you will need
2836 to port U-Boot to your hardware platform. To do this, follow these
2839 1. Add a new configuration option for your board to the toplevel
2840 "Makefile" and to the "MAKEALL" script, using the existing
2841 entries as examples. Note that here and at many other places
2842 boards and other names are listed in alphabetical sort order. Please
2844 2. Create a new directory to hold your board specific code. Add any
2845 files you need. In your board directory, you will need at least
2846 the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds".
2847 3. Create a new configuration file "include/configs/<board>.h" for
2849 3. If you're porting U-Boot to a new CPU, then also create a new
2850 directory to hold your CPU specific code. Add any files you need.
2851 4. Run "make <board>_config" with your new name.
2852 5. Type "make", and you should get a working "u-boot.srec" file
2853 to be installed on your target system.
2854 6. Debug and solve any problems that might arise.
2855 [Of course, this last step is much harder than it sounds.]
2858 Testing of U-Boot Modifications, Ports to New Hardware, etc.:
2859 ==============================================================
2861 If you have modified U-Boot sources (for instance added a new board
2862 or support for new devices, a new CPU, etc.) you are expected to
2863 provide feedback to the other developers. The feedback normally takes
2864 the form of a "patch", i. e. a context diff against a certain (latest
2865 official or latest in the git repository) version of U-Boot sources.
2867 But before you submit such a patch, please verify that your modifi-
2868 cation did not break existing code. At least make sure that *ALL* of
2869 the supported boards compile WITHOUT ANY compiler warnings. To do so,
2870 just run the "MAKEALL" script, which will configure and build U-Boot
2871 for ALL supported system. Be warned, this will take a while. You can
2872 select which (cross) compiler to use by passing a `CROSS_COMPILE'
2873 environment variable to the script, i. e. to use the ELDK cross tools
2876 CROSS_COMPILE=ppc_8xx- MAKEALL
2878 or to build on a native PowerPC system you can type
2880 CROSS_COMPILE=' ' MAKEALL
2882 When using the MAKEALL script, the default behaviour is to build
2883 U-Boot in the source directory. This location can be changed by
2884 setting the BUILD_DIR environment variable. Also, for each target
2885 built, the MAKEALL script saves two log files (<target>.ERR and
2886 <target>.MAKEALL) in the <source dir>/LOG directory. This default
2887 location can be changed by setting the MAKEALL_LOGDIR environment
2888 variable. For example:
2890 export BUILD_DIR=/tmp/build
2891 export MAKEALL_LOGDIR=/tmp/log
2892 CROSS_COMPILE=ppc_8xx- MAKEALL
2894 With the above settings build objects are saved in the /tmp/build,
2895 log files are saved in the /tmp/log and the source tree remains clean
2896 during the whole build process.
2899 See also "U-Boot Porting Guide" below.
2902 Monitor Commands - Overview:
2903 ============================
2905 go - start application at address 'addr'
2906 run - run commands in an environment variable
2907 bootm - boot application image from memory
2908 bootp - boot image via network using BootP/TFTP protocol
2909 tftpboot- boot image via network using TFTP protocol
2910 and env variables "ipaddr" and "serverip"
2911 (and eventually "gatewayip")
2912 rarpboot- boot image via network using RARP/TFTP protocol
2913 diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
2914 loads - load S-Record file over serial line
2915 loadb - load binary file over serial line (kermit mode)
2917 mm - memory modify (auto-incrementing)
2918 nm - memory modify (constant address)
2919 mw - memory write (fill)
2921 cmp - memory compare
2922 crc32 - checksum calculation
2923 i2c - I2C sub-system
2924 sspi - SPI utility commands
2925 base - print or set address offset
2926 printenv- print environment variables
2927 setenv - set environment variables
2928 saveenv - save environment variables to persistent storage
2929 protect - enable or disable FLASH write protection
2930 erase - erase FLASH memory
2931 flinfo - print FLASH memory information
2932 bdinfo - print Board Info structure
2933 iminfo - print header information for application image
2934 coninfo - print console devices and informations
2935 ide - IDE sub-system
2936 loop - infinite loop on address range
2937 loopw - infinite write loop on address range
2938 mtest - simple RAM test
2939 icache - enable or disable instruction cache
2940 dcache - enable or disable data cache
2941 reset - Perform RESET of the CPU
2942 echo - echo args to console
2943 version - print monitor version
2944 help - print online help
2945 ? - alias for 'help'
2948 Monitor Commands - Detailed Description:
2949 ========================================
2953 For now: just type "help <command>".
2956 Environment Variables:
2957 ======================
2959 U-Boot supports user configuration using Environment Variables which
2960 can be made persistent by saving to Flash memory.
2962 Environment Variables are set using "setenv", printed using
2963 "printenv", and saved to Flash using "saveenv". Using "setenv"
2964 without a value can be used to delete a variable from the
2965 environment. As long as you don't save the environment you are
2966 working with an in-memory copy. In case the Flash area containing the
2967 environment is erased by accident, a default environment is provided.
2969 Some configuration options can be set using Environment Variables:
2971 baudrate - see CONFIG_BAUDRATE
2973 bootdelay - see CONFIG_BOOTDELAY
2975 bootcmd - see CONFIG_BOOTCOMMAND
2977 bootargs - Boot arguments when booting an RTOS image
2979 bootfile - Name of the image to load with TFTP
2981 bootm_low - Memory range available for image processing in the bootm
2982 command can be restricted. This variable is given as
2983 a hexadecimal number and defines lowest address allowed
2984 for use by the bootm command. See also "bootm_size"
2985 environment variable. Address defined by "bootm_low" is
2986 also the base of the initial memory mapping for the Linux
2987 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ.
2989 bootm_size - Memory range available for image processing in the bootm
2990 command can be restricted. This variable is given as
2991 a hexadecimal number and defines the size of the region
2992 allowed for use by the bootm command. See also "bootm_low"
2993 environment variable.
2995 updatefile - Location of the software update file on a TFTP server, used
2996 by the automatic software update feature. Please refer to
2997 documentation in doc/README.update for more details.
2999 autoload - if set to "no" (any string beginning with 'n'),
3000 "bootp" will just load perform a lookup of the
3001 configuration from the BOOTP server, but not try to
3002 load any image using TFTP
3004 autoscript - if set to "yes" commands like "loadb", "loady",
3005 "bootp", "tftpb", "rarpboot" and "nfs" will attempt
3006 to automatically run script images (by internally
3009 autoscript_uname - if script image is in a format (FIT) this
3010 variable is used to get script subimage unit name.
3012 autostart - if set to "yes", an image loaded using the "bootp",
3013 "rarpboot", "tftpboot" or "diskboot" commands will
3014 be automatically started (by internally calling
3017 If set to "no", a standalone image passed to the
3018 "bootm" command will be copied to the load address
3019 (and eventually uncompressed), but NOT be started.
3020 This can be used to load and uncompress arbitrary
3023 i2cfast - (PPC405GP|PPC405EP only)
3024 if set to 'y' configures Linux I2C driver for fast
3025 mode (400kHZ). This environment variable is used in
3026 initialization code. So, for changes to be effective
3027 it must be saved and board must be reset.
3029 initrd_high - restrict positioning of initrd images:
3030 If this variable is not set, initrd images will be
3031 copied to the highest possible address in RAM; this
3032 is usually what you want since it allows for
3033 maximum initrd size. If for some reason you want to
3034 make sure that the initrd image is loaded below the
3035 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment
3036 variable to a value of "no" or "off" or "0".
3037 Alternatively, you can set it to a maximum upper
3038 address to use (U-Boot will still check that it
3039 does not overwrite the U-Boot stack and data).
3041 For instance, when you have a system with 16 MB
3042 RAM, and want to reserve 4 MB from use by Linux,
3043 you can do this by adding "mem=12M" to the value of
3044 the "bootargs" variable. However, now you must make
3045 sure that the initrd image is placed in the first
3046 12 MB as well - this can be done with
3048 setenv initrd_high 00c00000
3050 If you set initrd_high to 0xFFFFFFFF, this is an
3051 indication to U-Boot that all addresses are legal
3052 for the Linux kernel, including addresses in flash
3053 memory. In this case U-Boot will NOT COPY the
3054 ramdisk at all. This may be useful to reduce the
3055 boot time on your system, but requires that this
3056 feature is supported by your Linux kernel.
3058 ipaddr - IP address; needed for tftpboot command
3060 loadaddr - Default load address for commands like "bootp",
3061 "rarpboot", "tftpboot", "loadb" or "diskboot"
3063 loads_echo - see CONFIG_LOADS_ECHO
3065 serverip - TFTP server IP address; needed for tftpboot command
3067 bootretry - see CONFIG_BOOT_RETRY_TIME
3069 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
3071 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
3073 ethprime - When CONFIG_NET_MULTI is enabled controls which
3074 interface is used first.
3076 ethact - When CONFIG_NET_MULTI is enabled controls which
3077 interface is currently active. For example you
3078 can do the following
3080 => setenv ethact FEC ETHERNET
3081 => ping 192.168.0.1 # traffic sent on FEC ETHERNET
3082 => setenv ethact SCC ETHERNET
3083 => ping 10.0.0.1 # traffic sent on SCC ETHERNET
3085 ethrotate - When set to "no" U-Boot does not go through all
3086 available network interfaces.
3087 It just stays at the currently selected interface.
3089 netretry - When set to "no" each network operation will
3090 either succeed or fail without retrying.
3091 When set to "once" the network operation will
3092 fail when all the available network interfaces
3093 are tried once without success.
3094 Useful on scripts which control the retry operation
3097 npe_ucode - set load address for the NPE microcode
3099 tftpsrcport - If this is set, the value is used for TFTP's
3102 tftpdstport - If this is set, the value is used for TFTP's UDP
3103 destination port instead of the Well Know Port 69.
3105 vlan - When set to a value < 4095 the traffic over
3106 Ethernet is encapsulated/received over 802.1q
3109 The following environment variables may be used and automatically
3110 updated by the network boot commands ("bootp" and "rarpboot"),
3111 depending the information provided by your boot server:
3113 bootfile - see above
3114 dnsip - IP address of your Domain Name Server
3115 dnsip2 - IP address of your secondary Domain Name Server
3116 gatewayip - IP address of the Gateway (Router) to use
3117 hostname - Target hostname
3119 netmask - Subnet Mask
3120 rootpath - Pathname of the root filesystem on the NFS server
3121 serverip - see above
3124 There are two special Environment Variables:
3126 serial# - contains hardware identification information such
3127 as type string and/or serial number
3128 ethaddr - Ethernet address
3130 These variables can be set only once (usually during manufacturing of
3131 the board). U-Boot refuses to delete or overwrite these variables
3132 once they have been set once.
3135 Further special Environment Variables:
3137 ver - Contains the U-Boot version string as printed
3138 with the "version" command. This variable is
3139 readonly (see CONFIG_VERSION_VARIABLE).
3142 Please note that changes to some configuration parameters may take
3143 only effect after the next boot (yes, that's just like Windoze :-).
3146 Command Line Parsing:
3147 =====================
3149 There are two different command line parsers available with U-Boot:
3150 the old "simple" one, and the much more powerful "hush" shell:
3152 Old, simple command line parser:
3153 --------------------------------
3155 - supports environment variables (through setenv / saveenv commands)
3156 - several commands on one line, separated by ';'
3157 - variable substitution using "... ${name} ..." syntax
3158 - special characters ('$', ';') can be escaped by prefixing with '\',
3160 setenv bootcmd bootm \${address}
3161 - You can also escape text by enclosing in single apostrophes, for example:
3162 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
3167 - similar to Bourne shell, with control structures like
3168 if...then...else...fi, for...do...done; while...do...done,
3169 until...do...done, ...
3170 - supports environment ("global") variables (through setenv / saveenv
3171 commands) and local shell variables (through standard shell syntax
3172 "name=value"); only environment variables can be used with "run"
3178 (1) If a command line (or an environment variable executed by a "run"
3179 command) contains several commands separated by semicolon, and
3180 one of these commands fails, then the remaining commands will be
3183 (2) If you execute several variables with one call to run (i. e.
3184 calling run with a list of variables as arguments), any failing
3185 command will cause "run" to terminate, i. e. the remaining
3186 variables are not executed.
3188 Note for Redundant Ethernet Interfaces:
3189 =======================================
3191 Some boards come with redundant Ethernet interfaces; U-Boot supports
3192 such configurations and is capable of automatic selection of a
3193 "working" interface when needed. MAC assignment works as follows:
3195 Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
3196 MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
3197 "eth1addr" (=>eth1), "eth2addr", ...
3199 If the network interface stores some valid MAC address (for instance
3200 in SROM), this is used as default address if there is NO correspon-
3201 ding setting in the environment; if the corresponding environment
3202 variable is set, this overrides the settings in the card; that means:
3204 o If the SROM has a valid MAC address, and there is no address in the
3205 environment, the SROM's address is used.
3207 o If there is no valid address in the SROM, and a definition in the
3208 environment exists, then the value from the environment variable is
3211 o If both the SROM and the environment contain a MAC address, and
3212 both addresses are the same, this MAC address is used.
3214 o If both the SROM and the environment contain a MAC address, and the
3215 addresses differ, the value from the environment is used and a
3218 o If neither SROM nor the environment contain a MAC address, an error
3225 U-Boot is capable of booting (and performing other auxiliary operations on)
3226 images in two formats:
3228 New uImage format (FIT)
3229 -----------------------
3231 Flexible and powerful format based on Flattened Image Tree -- FIT (similar
3232 to Flattened Device Tree). It allows the use of images with multiple
3233 components (several kernels, ramdisks, etc.), with contents protected by
3234 SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory.
3240 Old image format is based on binary files which can be basically anything,
3241 preceded by a special header; see the definitions in include/image.h for
3242 details; basically, the header defines the following image properties:
3244 * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
3245 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
3246 LynxOS, pSOS, QNX, RTEMS, INTEGRITY;
3247 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS,
3249 * Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86,
3250 IA64, MIPS, NIOS, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
3251 Currently supported: ARM, AVR32, Intel x86, MIPS, NIOS, PowerPC).
3252 * Compression Type (uncompressed, gzip, bzip2)
3258 The header is marked by a special Magic Number, and both the header
3259 and the data portions of the image are secured against corruption by
3266 Although U-Boot should support any OS or standalone application
3267 easily, the main focus has always been on Linux during the design of
3270 U-Boot includes many features that so far have been part of some
3271 special "boot loader" code within the Linux kernel. Also, any
3272 "initrd" images to be used are no longer part of one big Linux image;
3273 instead, kernel and "initrd" are separate images. This implementation
3274 serves several purposes:
3276 - the same features can be used for other OS or standalone
3277 applications (for instance: using compressed images to reduce the
3278 Flash memory footprint)
3280 - it becomes much easier to port new Linux kernel versions because
3281 lots of low-level, hardware dependent stuff are done by U-Boot
3283 - the same Linux kernel image can now be used with different "initrd"
3284 images; of course this also means that different kernel images can
3285 be run with the same "initrd". This makes testing easier (you don't
3286 have to build a new "zImage.initrd" Linux image when you just
3287 change a file in your "initrd"). Also, a field-upgrade of the
3288 software is easier now.
3294 Porting Linux to U-Boot based systems:
3295 ---------------------------------------
3297 U-Boot cannot save you from doing all the necessary modifications to
3298 configure the Linux device drivers for use with your target hardware
3299 (no, we don't intend to provide a full virtual machine interface to
3302 But now you can ignore ALL boot loader code (in arch/ppc/mbxboot).
3304 Just make sure your machine specific header file (for instance
3305 include/asm-ppc/tqm8xx.h) includes the same definition of the Board
3306 Information structure as we define in include/asm-<arch>/u-boot.h,
3307 and make sure that your definition of IMAP_ADDR uses the same value
3308 as your U-Boot configuration in CONFIG_SYS_IMMR.
3311 Configuring the Linux kernel:
3312 -----------------------------
3314 No specific requirements for U-Boot. Make sure you have some root
3315 device (initial ramdisk, NFS) for your target system.
3318 Building a Linux Image:
3319 -----------------------
3321 With U-Boot, "normal" build targets like "zImage" or "bzImage" are
3322 not used. If you use recent kernel source, a new build target
3323 "uImage" will exist which automatically builds an image usable by
3324 U-Boot. Most older kernels also have support for a "pImage" target,
3325 which was introduced for our predecessor project PPCBoot and uses a
3326 100% compatible format.
3335 The "uImage" build target uses a special tool (in 'tools/mkimage') to
3336 encapsulate a compressed Linux kernel image with header information,
3337 CRC32 checksum etc. for use with U-Boot. This is what we are doing:
3339 * build a standard "vmlinux" kernel image (in ELF binary format):
3341 * convert the kernel into a raw binary image:
3343 ${CROSS_COMPILE}-objcopy -O binary \
3344 -R .note -R .comment \
3345 -S vmlinux linux.bin
3347 * compress the binary image:
3351 * package compressed binary image for U-Boot:
3353 mkimage -A ppc -O linux -T kernel -C gzip \
3354 -a 0 -e 0 -n "Linux Kernel Image" \
3355 -d linux.bin.gz uImage
3358 The "mkimage" tool can also be used to create ramdisk images for use
3359 with U-Boot, either separated from the Linux kernel image, or
3360 combined into one file. "mkimage" encapsulates the images with a 64
3361 byte header containing information about target architecture,
3362 operating system, image type, compression method, entry points, time
3363 stamp, CRC32 checksums, etc.
3365 "mkimage" can be called in two ways: to verify existing images and
3366 print the header information, or to build new images.
3368 In the first form (with "-l" option) mkimage lists the information
3369 contained in the header of an existing U-Boot image; this includes
3370 checksum verification:
3372 tools/mkimage -l image
3373 -l ==> list image header information
3375 The second form (with "-d" option) is used to build a U-Boot image
3376 from a "data file" which is used as image payload:
3378 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
3379 -n name -d data_file image
3380 -A ==> set architecture to 'arch'
3381 -O ==> set operating system to 'os'
3382 -T ==> set image type to 'type'
3383 -C ==> set compression type 'comp'
3384 -a ==> set load address to 'addr' (hex)
3385 -e ==> set entry point to 'ep' (hex)
3386 -n ==> set image name to 'name'
3387 -d ==> use image data from 'datafile'
3389 Right now, all Linux kernels for PowerPC systems use the same load
3390 address (0x00000000), but the entry point address depends on the
3393 - 2.2.x kernels have the entry point at 0x0000000C,
3394 - 2.3.x and later kernels have the entry point at 0x00000000.
3396 So a typical call to build a U-Boot image would read:
3398 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
3399 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
3400 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux.gz \
3401 > examples/uImage.TQM850L
3402 Image Name: 2.4.4 kernel for TQM850L
3403 Created: Wed Jul 19 02:34:59 2000
3404 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3405 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
3406 Load Address: 0x00000000
3407 Entry Point: 0x00000000
3409 To verify the contents of the image (or check for corruption):
3411 -> tools/mkimage -l examples/uImage.TQM850L
3412 Image Name: 2.4.4 kernel for TQM850L
3413 Created: Wed Jul 19 02:34:59 2000
3414 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3415 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
3416 Load Address: 0x00000000
3417 Entry Point: 0x00000000
3419 NOTE: for embedded systems where boot time is critical you can trade
3420 speed for memory and install an UNCOMPRESSED image instead: this
3421 needs more space in Flash, but boots much faster since it does not
3422 need to be uncompressed:
3424 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux.gz
3425 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
3426 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
3427 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux \
3428 > examples/uImage.TQM850L-uncompressed
3429 Image Name: 2.4.4 kernel for TQM850L
3430 Created: Wed Jul 19 02:34:59 2000
3431 Image Type: PowerPC Linux Kernel Image (uncompressed)
3432 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
3433 Load Address: 0x00000000
3434 Entry Point: 0x00000000
3437 Similar you can build U-Boot images from a 'ramdisk.image.gz' file
3438 when your kernel is intended to use an initial ramdisk:
3440 -> tools/mkimage -n 'Simple Ramdisk Image' \
3441 > -A ppc -O linux -T ramdisk -C gzip \
3442 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
3443 Image Name: Simple Ramdisk Image
3444 Created: Wed Jan 12 14:01:50 2000
3445 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
3446 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
3447 Load Address: 0x00000000
3448 Entry Point: 0x00000000
3451 Installing a Linux Image:
3452 -------------------------
3454 To downloading a U-Boot image over the serial (console) interface,
3455 you must convert the image to S-Record format:
3457 objcopy -I binary -O srec examples/image examples/image.srec
3459 The 'objcopy' does not understand the information in the U-Boot
3460 image header, so the resulting S-Record file will be relative to
3461 address 0x00000000. To load it to a given address, you need to
3462 specify the target address as 'offset' parameter with the 'loads'
3465 Example: install the image to address 0x40100000 (which on the
3466 TQM8xxL is in the first Flash bank):
3468 => erase 40100000 401FFFFF
3474 ## Ready for S-Record download ...
3475 ~>examples/image.srec
3476 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
3478 15989 15990 15991 15992
3479 [file transfer complete]
3481 ## Start Addr = 0x00000000
3484 You can check the success of the download using the 'iminfo' command;
3485 this includes a checksum verification so you can be sure no data
3486 corruption happened:
3490 ## Checking Image at 40100000 ...
3491 Image Name: 2.2.13 for initrd on TQM850L
3492 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3493 Data Size: 335725 Bytes = 327 kB = 0 MB
3494 Load Address: 00000000
3495 Entry Point: 0000000c
3496 Verifying Checksum ... OK
3502 The "bootm" command is used to boot an application that is stored in
3503 memory (RAM or Flash). In case of a Linux kernel image, the contents
3504 of the "bootargs" environment variable is passed to the kernel as
3505 parameters. You can check and modify this variable using the
3506 "printenv" and "setenv" commands:
3509 => printenv bootargs
3510 bootargs=root=/dev/ram
3512 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
3514 => printenv bootargs
3515 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
3518 ## Booting Linux kernel at 40020000 ...
3519 Image Name: 2.2.13 for NFS on TQM850L
3520 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3521 Data Size: 381681 Bytes = 372 kB = 0 MB
3522 Load Address: 00000000
3523 Entry Point: 0000000c
3524 Verifying Checksum ... OK
3525 Uncompressing Kernel Image ... OK
3526 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
3527 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
3528 time_init: decrementer frequency = 187500000/60
3529 Calibrating delay loop... 49.77 BogoMIPS
3530 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
3533 If you want to boot a Linux kernel with initial RAM disk, you pass
3534 the memory addresses of both the kernel and the initrd image (PPBCOOT
3535 format!) to the "bootm" command:
3537 => imi 40100000 40200000
3539 ## Checking Image at 40100000 ...
3540 Image Name: 2.2.13 for initrd on TQM850L
3541 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3542 Data Size: 335725 Bytes = 327 kB = 0 MB
3543 Load Address: 00000000
3544 Entry Point: 0000000c
3545 Verifying Checksum ... OK
3547 ## Checking Image at 40200000 ...
3548 Image Name: Simple Ramdisk Image
3549 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
3550 Data Size: 566530 Bytes = 553 kB = 0 MB
3551 Load Address: 00000000
3552 Entry Point: 00000000
3553 Verifying Checksum ... OK
3555 => bootm 40100000 40200000
3556 ## Booting Linux kernel at 40100000 ...
3557 Image Name: 2.2.13 for initrd on TQM850L
3558 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3559 Data Size: 335725 Bytes = 327 kB = 0 MB
3560 Load Address: 00000000
3561 Entry Point: 0000000c
3562 Verifying Checksum ... OK
3563 Uncompressing Kernel Image ... OK
3564 ## Loading RAMDisk Image at 40200000 ...
3565 Image Name: Simple Ramdisk Image
3566 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
3567 Data Size: 566530 Bytes = 553 kB = 0 MB
3568 Load Address: 00000000
3569 Entry Point: 00000000
3570 Verifying Checksum ... OK
3571 Loading Ramdisk ... OK
3572 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
3573 Boot arguments: root=/dev/ram
3574 time_init: decrementer frequency = 187500000/60
3575 Calibrating delay loop... 49.77 BogoMIPS
3577 RAMDISK: Compressed image found at block 0
3578 VFS: Mounted root (ext2 filesystem).
3582 Boot Linux and pass a flat device tree:
3585 First, U-Boot must be compiled with the appropriate defines. See the section
3586 titled "Linux Kernel Interface" above for a more in depth explanation. The
3587 following is an example of how to start a kernel and pass an updated
3593 oft=oftrees/mpc8540ads.dtb
3594 => tftp $oftaddr $oft
3595 Speed: 1000, full duplex
3597 TFTP from server 192.168.1.1; our IP address is 192.168.1.101
3598 Filename 'oftrees/mpc8540ads.dtb'.
3599 Load address: 0x300000
3602 Bytes transferred = 4106 (100a hex)
3603 => tftp $loadaddr $bootfile
3604 Speed: 1000, full duplex
3606 TFTP from server 192.168.1.1; our IP address is 192.168.1.2
3608 Load address: 0x200000
3609 Loading:############
3611 Bytes transferred = 1029407 (fb51f hex)
3616 => bootm $loadaddr - $oftaddr
3617 ## Booting image at 00200000 ...
3618 Image Name: Linux-2.6.17-dirty
3619 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3620 Data Size: 1029343 Bytes = 1005.2 kB
3621 Load Address: 00000000
3622 Entry Point: 00000000
3623 Verifying Checksum ... OK
3624 Uncompressing Kernel Image ... OK
3625 Booting using flat device tree at 0x300000
3626 Using MPC85xx ADS machine description
3627 Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb
3631 More About U-Boot Image Types:
3632 ------------------------------
3634 U-Boot supports the following image types:
3636 "Standalone Programs" are directly runnable in the environment
3637 provided by U-Boot; it is expected that (if they behave
3638 well) you can continue to work in U-Boot after return from
3639 the Standalone Program.
3640 "OS Kernel Images" are usually images of some Embedded OS which
3641 will take over control completely. Usually these programs
3642 will install their own set of exception handlers, device
3643 drivers, set up the MMU, etc. - this means, that you cannot
3644 expect to re-enter U-Boot except by resetting the CPU.
3645 "RAMDisk Images" are more or less just data blocks, and their
3646 parameters (address, size) are passed to an OS kernel that is
3648 "Multi-File Images" contain several images, typically an OS
3649 (Linux) kernel image and one or more data images like
3650 RAMDisks. This construct is useful for instance when you want
3651 to boot over the network using BOOTP etc., where the boot
3652 server provides just a single image file, but you want to get
3653 for instance an OS kernel and a RAMDisk image.
3655 "Multi-File Images" start with a list of image sizes, each
3656 image size (in bytes) specified by an "uint32_t" in network
3657 byte order. This list is terminated by an "(uint32_t)0".
3658 Immediately after the terminating 0 follow the images, one by
3659 one, all aligned on "uint32_t" boundaries (size rounded up to
3660 a multiple of 4 bytes).
3662 "Firmware Images" are binary images containing firmware (like
3663 U-Boot or FPGA images) which usually will be programmed to
3666 "Script files" are command sequences that will be executed by
3667 U-Boot's command interpreter; this feature is especially
3668 useful when you configure U-Boot to use a real shell (hush)
3669 as command interpreter.
3675 One of the features of U-Boot is that you can dynamically load and
3676 run "standalone" applications, which can use some resources of
3677 U-Boot like console I/O functions or interrupt services.
3679 Two simple examples are included with the sources:
3684 'examples/hello_world.c' contains a small "Hello World" Demo
3685 application; it is automatically compiled when you build U-Boot.
3686 It's configured to run at address 0x00040004, so you can play with it
3690 ## Ready for S-Record download ...
3691 ~>examples/hello_world.srec
3692 1 2 3 4 5 6 7 8 9 10 11 ...
3693 [file transfer complete]
3695 ## Start Addr = 0x00040004
3697 => go 40004 Hello World! This is a test.
3698 ## Starting application at 0x00040004 ...
3709 Hit any key to exit ...
3711 ## Application terminated, rc = 0x0
3713 Another example, which demonstrates how to register a CPM interrupt
3714 handler with the U-Boot code, can be found in 'examples/timer.c'.
3715 Here, a CPM timer is set up to generate an interrupt every second.
3716 The interrupt service routine is trivial, just printing a '.'
3717 character, but this is just a demo program. The application can be
3718 controlled by the following keys:
3720 ? - print current values og the CPM Timer registers
3721 b - enable interrupts and start timer
3722 e - stop timer and disable interrupts
3723 q - quit application
3726 ## Ready for S-Record download ...
3727 ~>examples/timer.srec
3728 1 2 3 4 5 6 7 8 9 10 11 ...
3729 [file transfer complete]
3731 ## Start Addr = 0x00040004
3734 ## Starting application at 0x00040004 ...
3737 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
3740 [q, b, e, ?] Set interval 1000000 us
3743 [q, b, e, ?] ........
3744 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
3747 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
3750 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
3753 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
3755 [q, b, e, ?] ...Stopping timer
3757 [q, b, e, ?] ## Application terminated, rc = 0x0
3763 Over time, many people have reported problems when trying to use the
3764 "minicom" terminal emulation program for serial download. I (wd)
3765 consider minicom to be broken, and recommend not to use it. Under
3766 Unix, I recommend to use C-Kermit for general purpose use (and
3767 especially for kermit binary protocol download ("loadb" command), and
3768 use "cu" for S-Record download ("loads" command).
3770 Nevertheless, if you absolutely want to use it try adding this
3771 configuration to your "File transfer protocols" section:
3773 Name Program Name U/D FullScr IO-Red. Multi
3774 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
3775 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
3781 Starting at version 0.9.2, U-Boot supports NetBSD both as host
3782 (build U-Boot) and target system (boots NetBSD/mpc8xx).
3784 Building requires a cross environment; it is known to work on
3785 NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
3786 need gmake since the Makefiles are not compatible with BSD make).
3787 Note that the cross-powerpc package does not install include files;
3788 attempting to build U-Boot will fail because <machine/ansi.h> is
3789 missing. This file has to be installed and patched manually:
3791 # cd /usr/pkg/cross/powerpc-netbsd/include
3793 # ln -s powerpc machine
3794 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
3795 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
3797 Native builds *don't* work due to incompatibilities between native
3798 and U-Boot include files.
3800 Booting assumes that (the first part of) the image booted is a
3801 stage-2 loader which in turn loads and then invokes the kernel
3802 proper. Loader sources will eventually appear in the NetBSD source
3803 tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
3804 meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz
3807 Implementation Internals:
3808 =========================
3810 The following is not intended to be a complete description of every
3811 implementation detail. However, it should help to understand the
3812 inner workings of U-Boot and make it easier to port it to custom
3816 Initial Stack, Global Data:
3817 ---------------------------
3819 The implementation of U-Boot is complicated by the fact that U-Boot
3820 starts running out of ROM (flash memory), usually without access to
3821 system RAM (because the memory controller is not initialized yet).
3822 This means that we don't have writable Data or BSS segments, and BSS
3823 is not initialized as zero. To be able to get a C environment working
3824 at all, we have to allocate at least a minimal stack. Implementation
3825 options for this are defined and restricted by the CPU used: Some CPU
3826 models provide on-chip memory (like the IMMR area on MPC8xx and
3827 MPC826x processors), on others (parts of) the data cache can be
3828 locked as (mis-) used as memory, etc.
3830 Chris Hallinan posted a good summary of these issues to the
3831 U-Boot mailing list:
3833 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
3834 From: "Chris Hallinan" <clh@net1plus.com>
3835 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
3838 Correct me if I'm wrong, folks, but the way I understand it
3839 is this: Using DCACHE as initial RAM for Stack, etc, does not
3840 require any physical RAM backing up the cache. The cleverness
3841 is that the cache is being used as a temporary supply of
3842 necessary storage before the SDRAM controller is setup. It's
3843 beyond the scope of this list to explain the details, but you
3844 can see how this works by studying the cache architecture and
3845 operation in the architecture and processor-specific manuals.
3847 OCM is On Chip Memory, which I believe the 405GP has 4K. It
3848 is another option for the system designer to use as an
3849 initial stack/RAM area prior to SDRAM being available. Either
3850 option should work for you. Using CS 4 should be fine if your
3851 board designers haven't used it for something that would
3852 cause you grief during the initial boot! It is frequently not
3855 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere
3856 with your processor/board/system design. The default value
3857 you will find in any recent u-boot distribution in
3858 walnut.h should work for you. I'd set it to a value larger
3859 than your SDRAM module. If you have a 64MB SDRAM module, set
3860 it above 400_0000. Just make sure your board has no resources
3861 that are supposed to respond to that address! That code in
3862 start.S has been around a while and should work as is when
3863 you get the config right.
3868 It is essential to remember this, since it has some impact on the C
3869 code for the initialization procedures:
3871 * Initialized global data (data segment) is read-only. Do not attempt
3874 * Do not use any uninitialized global data (or implicitely initialized
3875 as zero data - BSS segment) at all - this is undefined, initiali-
3876 zation is performed later (when relocating to RAM).
3878 * Stack space is very limited. Avoid big data buffers or things like
3881 Having only the stack as writable memory limits means we cannot use
3882 normal global data to share information beween the code. But it
3883 turned out that the implementation of U-Boot can be greatly
3884 simplified by making a global data structure (gd_t) available to all
3885 functions. We could pass a pointer to this data as argument to _all_
3886 functions, but this would bloat the code. Instead we use a feature of
3887 the GCC compiler (Global Register Variables) to share the data: we
3888 place a pointer (gd) to the global data into a register which we
3889 reserve for this purpose.
3891 When choosing a register for such a purpose we are restricted by the
3892 relevant (E)ABI specifications for the current architecture, and by
3893 GCC's implementation.
3895 For PowerPC, the following registers have specific use:
3897 R2: reserved for system use
3898 R3-R4: parameter passing and return values
3899 R5-R10: parameter passing
3900 R13: small data area pointer
3904 (U-Boot also uses R14 as internal GOT pointer.)
3906 ==> U-Boot will use R2 to hold a pointer to the global data
3908 Note: on PPC, we could use a static initializer (since the
3909 address of the global data structure is known at compile time),
3910 but it turned out that reserving a register results in somewhat
3911 smaller code - although the code savings are not that big (on
3912 average for all boards 752 bytes for the whole U-Boot image,
3913 624 text + 127 data).
3915 On Blackfin, the normal C ABI (except for P3) is followed as documented here:
3916 http://docs.blackfin.uclinux.org/doku.php?id=application_binary_interface
3918 ==> U-Boot will use P3 to hold a pointer to the global data
3920 On ARM, the following registers are used:
3922 R0: function argument word/integer result
3923 R1-R3: function argument word
3925 R10: stack limit (used only if stack checking if enabled)
3926 R11: argument (frame) pointer
3927 R12: temporary workspace
3930 R15: program counter
3932 ==> U-Boot will use R8 to hold a pointer to the global data
3934 NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope,
3935 or current versions of GCC may "optimize" the code too much.
3940 U-Boot runs in system state and uses physical addresses, i.e. the
3941 MMU is not used either for address mapping nor for memory protection.
3943 The available memory is mapped to fixed addresses using the memory
3944 controller. In this process, a contiguous block is formed for each
3945 memory type (Flash, SDRAM, SRAM), even when it consists of several
3946 physical memory banks.
3948 U-Boot is installed in the first 128 kB of the first Flash bank (on
3949 TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
3950 booting and sizing and initializing DRAM, the code relocates itself
3951 to the upper end of DRAM. Immediately below the U-Boot code some
3952 memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN
3953 configuration setting]. Below that, a structure with global Board
3954 Info data is placed, followed by the stack (growing downward).
3956 Additionally, some exception handler code is copied to the low 8 kB
3957 of DRAM (0x00000000 ... 0x00001FFF).
3959 So a typical memory configuration with 16 MB of DRAM could look like
3962 0x0000 0000 Exception Vector code
3965 0x0000 2000 Free for Application Use
3971 0x00FB FF20 Monitor Stack (Growing downward)
3972 0x00FB FFAC Board Info Data and permanent copy of global data
3973 0x00FC 0000 Malloc Arena
3976 0x00FE 0000 RAM Copy of Monitor Code
3977 ... eventually: LCD or video framebuffer
3978 ... eventually: pRAM (Protected RAM - unchanged by reset)
3979 0x00FF FFFF [End of RAM]
3982 System Initialization:
3983 ----------------------
3985 In the reset configuration, U-Boot starts at the reset entry point
3986 (on most PowerPC systems at address 0x00000100). Because of the reset
3987 configuration for CS0# this is a mirror of the onboard Flash memory.
3988 To be able to re-map memory U-Boot then jumps to its link address.
3989 To be able to implement the initialization code in C, a (small!)
3990 initial stack is set up in the internal Dual Ported RAM (in case CPUs
3991 which provide such a feature like MPC8xx or MPC8260), or in a locked
3992 part of the data cache. After that, U-Boot initializes the CPU core,
3993 the caches and the SIU.
3995 Next, all (potentially) available memory banks are mapped using a
3996 preliminary mapping. For example, we put them on 512 MB boundaries
3997 (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
3998 on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
3999 programmed for SDRAM access. Using the temporary configuration, a
4000 simple memory test is run that determines the size of the SDRAM
4003 When there is more than one SDRAM bank, and the banks are of
4004 different size, the largest is mapped first. For equal size, the first
4005 bank (CS2#) is mapped first. The first mapping is always for address
4006 0x00000000, with any additional banks following immediately to create
4007 contiguous memory starting from 0.
4009 Then, the monitor installs itself at the upper end of the SDRAM area
4010 and allocates memory for use by malloc() and for the global Board
4011 Info data; also, the exception vector code is copied to the low RAM
4012 pages, and the final stack is set up.
4014 Only after this relocation will you have a "normal" C environment;
4015 until that you are restricted in several ways, mostly because you are
4016 running from ROM, and because the code will have to be relocated to a
4020 U-Boot Porting Guide:
4021 ----------------------
4023 [Based on messages by Jerry Van Baren in the U-Boot-Users mailing
4027 int main(int argc, char *argv[])
4029 sighandler_t no_more_time;
4031 signal(SIGALRM, no_more_time);
4032 alarm(PROJECT_DEADLINE - toSec (3 * WEEK));
4034 if (available_money > available_manpower) {
4035 Pay consultant to port U-Boot;
4039 Download latest U-Boot source;
4041 Subscribe to u-boot mailing list;
4044 email("Hi, I am new to U-Boot, how do I get started?");
4047 Read the README file in the top level directory;
4048 Read http://www.denx.de/twiki/bin/view/DULG/Manual;
4049 Read applicable doc/*.README;
4050 Read the source, Luke;
4051 /* find . -name "*.[chS]" | xargs grep -i <keyword> */
4054 if (available_money > toLocalCurrency ($2500))
4057 Add a lot of aggravation and time;
4059 if (a similar board exists) { /* hopefully... */
4060 cp -a board/<similar> board/<myboard>
4061 cp include/configs/<similar>.h include/configs/<myboard>.h
4063 Create your own board support subdirectory;
4064 Create your own board include/configs/<myboard>.h file;
4066 Edit new board/<myboard> files
4067 Edit new include/configs/<myboard>.h
4072 Add / modify source code;
4076 email("Hi, I am having problems...");
4078 Send patch file to the U-Boot email list;
4079 if (reasonable critiques)
4080 Incorporate improvements from email list code review;
4082 Defend code as written;
4088 void no_more_time (int sig)
4097 All contributions to U-Boot should conform to the Linux kernel
4098 coding style; see the file "Documentation/CodingStyle" and the script
4099 "scripts/Lindent" in your Linux kernel source directory. In sources
4100 originating from U-Boot a style corresponding to "Lindent -pcs" (adding
4101 spaces before parameters to function calls) is actually used.
4103 Source files originating from a different project (for example the
4104 MTD subsystem) are generally exempt from these guidelines and are not
4105 reformated to ease subsequent migration to newer versions of those
4108 Please note that U-Boot is implemented in C (and to some small parts in
4109 Assembler); no C++ is used, so please do not use C++ style comments (//)
4112 Please also stick to the following formatting rules:
4113 - remove any trailing white space
4114 - use TAB characters for indentation, not spaces
4115 - make sure NOT to use DOS '\r\n' line feeds
4116 - do not add more than 2 empty lines to source files
4117 - do not add trailing empty lines to source files
4119 Submissions which do not conform to the standards may be returned
4120 with a request to reformat the changes.
4126 Since the number of patches for U-Boot is growing, we need to
4127 establish some rules. Submissions which do not conform to these rules
4128 may be rejected, even when they contain important and valuable stuff.
4130 Please see http://www.denx.de/wiki/U-Boot/Patches for details.
4132 Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>;
4133 see http://lists.denx.de/mailman/listinfo/u-boot
4135 When you send a patch, please include the following information with
4138 * For bug fixes: a description of the bug and how your patch fixes
4139 this bug. Please try to include a way of demonstrating that the
4140 patch actually fixes something.
4142 * For new features: a description of the feature and your
4145 * A CHANGELOG entry as plaintext (separate from the patch)
4147 * For major contributions, your entry to the CREDITS file
4149 * When you add support for a new board, don't forget to add this
4150 board to the MAKEALL script, too.
4152 * If your patch adds new configuration options, don't forget to
4153 document these in the README file.
4155 * The patch itself. If you are using git (which is *strongly*
4156 recommended) you can easily generate the patch using the
4157 "git-format-patch". If you then use "git-send-email" to send it to
4158 the U-Boot mailing list, you will avoid most of the common problems
4159 with some other mail clients.
4161 If you cannot use git, use "diff -purN OLD NEW". If your version of
4162 diff does not support these options, then get the latest version of
4165 The current directory when running this command shall be the parent
4166 directory of the U-Boot source tree (i. e. please make sure that
4167 your patch includes sufficient directory information for the
4170 We prefer patches as plain text. MIME attachments are discouraged,
4171 and compressed attachments must not be used.
4173 * If one logical set of modifications affects or creates several
4174 files, all these changes shall be submitted in a SINGLE patch file.
4176 * Changesets that contain different, unrelated modifications shall be
4177 submitted as SEPARATE patches, one patch per changeset.
4182 * Before sending the patch, run the MAKEALL script on your patched
4183 source tree and make sure that no errors or warnings are reported
4184 for any of the boards.
4186 * Keep your modifications to the necessary minimum: A patch
4187 containing several unrelated changes or arbitrary reformats will be
4188 returned with a request to re-formatting / split it.
4190 * If you modify existing code, make sure that your new code does not
4191 add to the memory footprint of the code ;-) Small is beautiful!
4192 When adding new features, these should compile conditionally only
4193 (using #ifdef), and the resulting code with the new feature
4194 disabled must not need more memory than the old code without your
4197 * Remember that there is a size limit of 100 kB per message on the
4198 u-boot mailing list. Bigger patches will be moderated. If they are
4199 reasonable and not too big, they will be acknowledged. But patches
4200 bigger than the size limit should be avoided.
projects / platform / kernel / u-boot.git / blob