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
862 for differential drivers: 0x00001000
863 for single ended drivers: 0x00005000
864 CONFIG_SYS_USB_EVENT_POLL
865 May be defined to allow interrupt polling
866 instead of using asynchronous interrupts
869 Define the below if you wish to use the USB console.
870 Once firmware is rebuilt from a serial console issue the
871 command "setenv stdin usbtty; setenv stdout usbtty" and
872 attach your USB cable. The Unix command "dmesg" should print
873 it has found a new device. The environment variable usbtty
874 can be set to gserial or cdc_acm to enable your device to
875 appear to a USB host as a Linux gserial device or a
876 Common Device Class Abstract Control Model serial device.
877 If you select usbtty = gserial you should be able to enumerate
879 # modprobe usbserial vendor=0xVendorID product=0xProductID
880 else if using cdc_acm, simply setting the environment
881 variable usbtty to be cdc_acm should suffice. The following
882 might be defined in YourBoardName.h
885 Define this to build a UDC device
888 Define this to have a tty type of device available to
889 talk to the UDC device
891 CONFIG_SYS_CONSOLE_IS_IN_ENV
892 Define this if you want stdin, stdout &/or stderr to
896 CONFIG_SYS_USB_EXTC_CLK 0xBLAH
897 Derive USB clock from external clock "blah"
898 - CONFIG_SYS_USB_EXTC_CLK 0x02
900 CONFIG_SYS_USB_BRG_CLK 0xBLAH
901 Derive USB clock from brgclk
902 - CONFIG_SYS_USB_BRG_CLK 0x04
904 If you have a USB-IF assigned VendorID then you may wish to
905 define your own vendor specific values either in BoardName.h
906 or directly in usbd_vendor_info.h. If you don't define
907 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME,
908 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot
909 should pretend to be a Linux device to it's target host.
911 CONFIG_USBD_MANUFACTURER
912 Define this string as the name of your company for
913 - CONFIG_USBD_MANUFACTURER "my company"
915 CONFIG_USBD_PRODUCT_NAME
916 Define this string as the name of your product
917 - CONFIG_USBD_PRODUCT_NAME "acme usb device"
920 Define this as your assigned Vendor ID from the USB
921 Implementors Forum. This *must* be a genuine Vendor ID
922 to avoid polluting the USB namespace.
923 - CONFIG_USBD_VENDORID 0xFFFF
925 CONFIG_USBD_PRODUCTID
926 Define this as the unique Product ID
928 - CONFIG_USBD_PRODUCTID 0xFFFF
932 The MMC controller on the Intel PXA is supported. To
933 enable this define CONFIG_MMC. The MMC can be
934 accessed from the boot prompt by mapping the device
935 to physical memory similar to flash. Command line is
936 enabled with CONFIG_CMD_MMC. The MMC driver also works with
937 the FAT fs. This is enabled with CONFIG_CMD_FAT.
939 - Journaling Flash filesystem support:
940 CONFIG_JFFS2_NAND, CONFIG_JFFS2_NAND_OFF, CONFIG_JFFS2_NAND_SIZE,
941 CONFIG_JFFS2_NAND_DEV
942 Define these for a default partition on a NAND device
944 CONFIG_SYS_JFFS2_FIRST_SECTOR,
945 CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS
946 Define these for a default partition on a NOR device
948 CONFIG_SYS_JFFS_CUSTOM_PART
949 Define this to create an own partition. You have to provide a
950 function struct part_info* jffs2_part_info(int part_num)
952 If you define only one JFFS2 partition you may also want to
953 #define CONFIG_SYS_JFFS_SINGLE_PART 1
954 to disable the command chpart. This is the default when you
955 have not defined a custom partition
960 Define this to enable standard (PC-Style) keyboard
964 Standard PC keyboard driver with US (is default) and
965 GERMAN key layout (switch via environment 'keymap=de') support.
966 Export function i8042_kbd_init, i8042_tstc and i8042_getc
967 for cfb_console. Supports cursor blinking.
972 Define this to enable video support (for output to
977 Enable Chips & Technologies 69000 Video chip
979 CONFIG_VIDEO_SMI_LYNXEM
980 Enable Silicon Motion SMI 712/710/810 Video chip. The
981 video output is selected via environment 'videoout'
982 (1 = LCD and 2 = CRT). If videoout is undefined, CRT is
985 For the CT69000 and SMI_LYNXEM drivers, videomode is
986 selected via environment 'videomode'. Two different ways
988 - "videomode=num" 'num' is a standard LiLo mode numbers.
989 Following standard modes are supported (* is default):
991 Colors 640x480 800x600 1024x768 1152x864 1280x1024
992 -------------+---------------------------------------------
993 8 bits | 0x301* 0x303 0x305 0x161 0x307
994 15 bits | 0x310 0x313 0x316 0x162 0x319
995 16 bits | 0x311 0x314 0x317 0x163 0x31A
996 24 bits | 0x312 0x315 0x318 ? 0x31B
997 -------------+---------------------------------------------
998 (i.e. setenv videomode 317; saveenv; reset;)
1000 - "videomode=bootargs" all the video parameters are parsed
1001 from the bootargs. (See drivers/video/videomodes.c)
1004 CONFIG_VIDEO_SED13806
1005 Enable Epson SED13806 driver. This driver supports 8bpp
1006 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP
1007 or CONFIG_VIDEO_SED13806_16BPP
1012 Define this to enable a custom keyboard support.
1013 This simply calls drv_keyboard_init() which must be
1014 defined in your board-specific files.
1015 The only board using this so far is RBC823.
1017 - LCD Support: CONFIG_LCD
1019 Define this to enable LCD support (for output to LCD
1020 display); also select one of the supported displays
1021 by defining one of these:
1025 HITACHI TX09D70VM1CCA, 3.5", 240x320.
1027 CONFIG_NEC_NL6448AC33:
1029 NEC NL6448AC33-18. Active, color, single scan.
1031 CONFIG_NEC_NL6448BC20
1033 NEC NL6448BC20-08. 6.5", 640x480.
1034 Active, color, single scan.
1036 CONFIG_NEC_NL6448BC33_54
1038 NEC NL6448BC33-54. 10.4", 640x480.
1039 Active, color, single scan.
1043 Sharp 320x240. Active, color, single scan.
1044 It isn't 16x9, and I am not sure what it is.
1046 CONFIG_SHARP_LQ64D341
1048 Sharp LQ64D341 display, 640x480.
1049 Active, color, single scan.
1053 HLD1045 display, 640x480.
1054 Active, color, single scan.
1058 Optrex CBL50840-2 NF-FW 99 22 M5
1060 Hitachi LMG6912RPFC-00T
1064 320x240. Black & white.
1066 Normally display is black on white background; define
1067 CONFIG_SYS_WHITE_ON_BLACK to get it inverted.
1069 - Splash Screen Support: CONFIG_SPLASH_SCREEN
1071 If this option is set, the environment is checked for
1072 a variable "splashimage". If found, the usual display
1073 of logo, copyright and system information on the LCD
1074 is suppressed and the BMP image at the address
1075 specified in "splashimage" is loaded instead. The
1076 console is redirected to the "nulldev", too. This
1077 allows for a "silent" boot where a splash screen is
1078 loaded very quickly after power-on.
1080 CONFIG_SPLASH_SCREEN_ALIGN
1082 If this option is set the splash image can be freely positioned
1083 on the screen. Environment variable "splashpos" specifies the
1084 position as "x,y". If a positive number is given it is used as
1085 number of pixel from left/top. If a negative number is given it
1086 is used as number of pixel from right/bottom. You can also
1087 specify 'm' for centering the image.
1090 setenv splashpos m,m
1091 => image at center of screen
1093 setenv splashpos 30,20
1094 => image at x = 30 and y = 20
1096 setenv splashpos -10,m
1097 => vertically centered image
1098 at x = dspWidth - bmpWidth - 9
1100 - Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP
1102 If this option is set, additionally to standard BMP
1103 images, gzipped BMP images can be displayed via the
1104 splashscreen support or the bmp command.
1106 - Compression support:
1109 If this option is set, support for bzip2 compressed
1110 images is included. If not, only uncompressed and gzip
1111 compressed images are supported.
1113 NOTE: the bzip2 algorithm requires a lot of RAM, so
1114 the malloc area (as defined by CONFIG_SYS_MALLOC_LEN) should
1119 If this option is set, support for lzma compressed
1122 Note: The LZMA algorithm adds between 2 and 4KB of code and it
1123 requires an amount of dynamic memory that is given by the
1126 (1846 + 768 << (lc + lp)) * sizeof(uint16)
1128 Where lc and lp stand for, respectively, Literal context bits
1129 and Literal pos bits.
1131 This value is upper-bounded by 14MB in the worst case. Anyway,
1132 for a ~4MB large kernel image, we have lc=3 and lp=0 for a
1133 total amount of (1846 + 768 << (3 + 0)) * 2 = ~41KB... that is
1134 a very small buffer.
1136 Use the lzmainfo tool to determinate the lc and lp values and
1137 then calculate the amount of needed dynamic memory (ensuring
1138 the appropriate CONFIG_SYS_MALLOC_LEN value).
1143 The address of PHY on MII bus.
1145 CONFIG_PHY_CLOCK_FREQ (ppc4xx)
1147 The clock frequency of the MII bus
1151 If this option is set, support for speed/duplex
1152 detection of gigabit PHY is included.
1154 CONFIG_PHY_RESET_DELAY
1156 Some PHY like Intel LXT971A need extra delay after
1157 reset before any MII register access is possible.
1158 For such PHY, set this option to the usec delay
1159 required. (minimum 300usec for LXT971A)
1161 CONFIG_PHY_CMD_DELAY (ppc4xx)
1163 Some PHY like Intel LXT971A need extra delay after
1164 command issued before MII status register can be read
1174 Define a default value for Ethernet address to use
1175 for the respective Ethernet interface, in case this
1176 is not determined automatically.
1181 Define a default value for the IP address to use for
1182 the default Ethernet interface, in case this is not
1183 determined through e.g. bootp.
1185 - Server IP address:
1188 Defines a default value for the IP address of a TFTP
1189 server to contact when using the "tftboot" command.
1191 CONFIG_KEEP_SERVERADDR
1193 Keeps the server's MAC address, in the env 'serveraddr'
1194 for passing to bootargs (like Linux's netconsole option)
1196 - Multicast TFTP Mode:
1199 Defines whether you want to support multicast TFTP as per
1200 rfc-2090; for example to work with atftp. Lets lots of targets
1201 tftp down the same boot image concurrently. Note: the Ethernet
1202 driver in use must provide a function: mcast() to join/leave a
1205 CONFIG_BOOTP_RANDOM_DELAY
1206 - BOOTP Recovery Mode:
1207 CONFIG_BOOTP_RANDOM_DELAY
1209 If you have many targets in a network that try to
1210 boot using BOOTP, you may want to avoid that all
1211 systems send out BOOTP requests at precisely the same
1212 moment (which would happen for instance at recovery
1213 from a power failure, when all systems will try to
1214 boot, thus flooding the BOOTP server. Defining
1215 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
1216 inserted before sending out BOOTP requests. The
1217 following delays are inserted then:
1219 1st BOOTP request: delay 0 ... 1 sec
1220 2nd BOOTP request: delay 0 ... 2 sec
1221 3rd BOOTP request: delay 0 ... 4 sec
1223 BOOTP requests: delay 0 ... 8 sec
1225 - DHCP Advanced Options:
1226 You can fine tune the DHCP functionality by defining
1227 CONFIG_BOOTP_* symbols:
1229 CONFIG_BOOTP_SUBNETMASK
1230 CONFIG_BOOTP_GATEWAY
1231 CONFIG_BOOTP_HOSTNAME
1232 CONFIG_BOOTP_NISDOMAIN
1233 CONFIG_BOOTP_BOOTPATH
1234 CONFIG_BOOTP_BOOTFILESIZE
1237 CONFIG_BOOTP_SEND_HOSTNAME
1238 CONFIG_BOOTP_NTPSERVER
1239 CONFIG_BOOTP_TIMEOFFSET
1240 CONFIG_BOOTP_VENDOREX
1242 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip
1243 environment variable, not the BOOTP server.
1245 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS
1246 serverip from a DHCP server, it is possible that more
1247 than one DNS serverip is offered to the client.
1248 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS
1249 serverip will be stored in the additional environment
1250 variable "dnsip2". The first DNS serverip is always
1251 stored in the variable "dnsip", when CONFIG_BOOTP_DNS
1254 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable
1255 to do a dynamic update of a DNS server. To do this, they
1256 need the hostname of the DHCP requester.
1257 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content
1258 of the "hostname" environment variable is passed as
1259 option 12 to the DHCP server.
1261 CONFIG_BOOTP_DHCP_REQUEST_DELAY
1263 A 32bit value in microseconds for a delay between
1264 receiving a "DHCP Offer" and sending the "DHCP Request".
1265 This fixes a problem with certain DHCP servers that don't
1266 respond 100% of the time to a "DHCP request". E.g. On an
1267 AT91RM9200 processor running at 180MHz, this delay needed
1268 to be *at least* 15,000 usec before a Windows Server 2003
1269 DHCP server would reply 100% of the time. I recommend at
1270 least 50,000 usec to be safe. The alternative is to hope
1271 that one of the retries will be successful but note that
1272 the DHCP timeout and retry process takes a longer than
1276 CONFIG_CDP_DEVICE_ID
1278 The device id used in CDP trigger frames.
1280 CONFIG_CDP_DEVICE_ID_PREFIX
1282 A two character string which is prefixed to the MAC address
1287 A printf format string which contains the ascii name of
1288 the port. Normally is set to "eth%d" which sets
1289 eth0 for the first Ethernet, eth1 for the second etc.
1291 CONFIG_CDP_CAPABILITIES
1293 A 32bit integer which indicates the device capabilities;
1294 0x00000010 for a normal host which does not forwards.
1298 An ascii string containing the version of the software.
1302 An ascii string containing the name of the platform.
1306 A 32bit integer sent on the trigger.
1308 CONFIG_CDP_POWER_CONSUMPTION
1310 A 16bit integer containing the power consumption of the
1311 device in .1 of milliwatts.
1313 CONFIG_CDP_APPLIANCE_VLAN_TYPE
1315 A byte containing the id of the VLAN.
1317 - Status LED: CONFIG_STATUS_LED
1319 Several configurations allow to display the current
1320 status using a LED. For instance, the LED will blink
1321 fast while running U-Boot code, stop blinking as
1322 soon as a reply to a BOOTP request was received, and
1323 start blinking slow once the Linux kernel is running
1324 (supported by a status LED driver in the Linux
1325 kernel). Defining CONFIG_STATUS_LED enables this
1328 - CAN Support: CONFIG_CAN_DRIVER
1330 Defining CONFIG_CAN_DRIVER enables CAN driver support
1331 on those systems that support this (optional)
1332 feature, like the TQM8xxL modules.
1334 - I2C Support: CONFIG_HARD_I2C | CONFIG_SOFT_I2C
1336 These enable I2C serial bus commands. Defining either of
1337 (but not both of) CONFIG_HARD_I2C or CONFIG_SOFT_I2C will
1338 include the appropriate I2C driver for the selected CPU.
1340 This will allow you to use i2c commands at the u-boot
1341 command line (as long as you set CONFIG_CMD_I2C in
1342 CONFIG_COMMANDS) and communicate with i2c based realtime
1343 clock chips. See common/cmd_i2c.c for a description of the
1344 command line interface.
1346 CONFIG_HARD_I2C selects a hardware I2C controller.
1348 CONFIG_SOFT_I2C configures u-boot to use a software (aka
1349 bit-banging) driver instead of CPM or similar hardware
1352 There are several other quantities that must also be
1353 defined when you define CONFIG_HARD_I2C or CONFIG_SOFT_I2C.
1355 In both cases you will need to define CONFIG_SYS_I2C_SPEED
1356 to be the frequency (in Hz) at which you wish your i2c bus
1357 to run and CONFIG_SYS_I2C_SLAVE to be the address of this node (ie
1358 the CPU's i2c node address).
1360 Now, the u-boot i2c code for the mpc8xx (cpu/mpc8xx/i2c.c)
1361 sets the CPU up as a master node and so its address should
1362 therefore be cleared to 0 (See, eg, MPC823e User's Manual
1363 p.16-473). So, set CONFIG_SYS_I2C_SLAVE to 0.
1365 That's all that's required for CONFIG_HARD_I2C.
1367 If you use the software i2c interface (CONFIG_SOFT_I2C)
1368 then the following macros need to be defined (examples are
1369 from include/configs/lwmon.h):
1373 (Optional). Any commands necessary to enable the I2C
1374 controller or configure ports.
1376 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
1380 (Only for MPC8260 CPU). The I/O port to use (the code
1381 assumes both bits are on the same port). Valid values
1382 are 0..3 for ports A..D.
1386 The code necessary to make the I2C data line active
1387 (driven). If the data line is open collector, this
1390 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
1394 The code necessary to make the I2C data line tri-stated
1395 (inactive). If the data line is open collector, this
1398 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
1402 Code that returns TRUE if the I2C data line is high,
1405 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
1409 If <bit> is TRUE, sets the I2C data line high. If it
1410 is FALSE, it clears it (low).
1412 eg: #define I2C_SDA(bit) \
1413 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
1414 else immr->im_cpm.cp_pbdat &= ~PB_SDA
1418 If <bit> is TRUE, sets the I2C clock line high. If it
1419 is FALSE, it clears it (low).
1421 eg: #define I2C_SCL(bit) \
1422 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
1423 else immr->im_cpm.cp_pbdat &= ~PB_SCL
1427 This delay is invoked four times per clock cycle so this
1428 controls the rate of data transfer. The data rate thus
1429 is 1 / (I2C_DELAY * 4). Often defined to be something
1432 #define I2C_DELAY udelay(2)
1434 CONFIG_SYS_I2C_INIT_BOARD
1436 When a board is reset during an i2c bus transfer
1437 chips might think that the current transfer is still
1438 in progress. On some boards it is possible to access
1439 the i2c SCLK line directly, either by using the
1440 processor pin as a GPIO or by having a second pin
1441 connected to the bus. If this option is defined a
1442 custom i2c_init_board() routine in boards/xxx/board.c
1443 is run early in the boot sequence.
1445 CONFIG_I2CFAST (PPC405GP|PPC405EP only)
1447 This option enables configuration of bi_iic_fast[] flags
1448 in u-boot bd_info structure based on u-boot environment
1449 variable "i2cfast". (see also i2cfast)
1451 CONFIG_I2C_MULTI_BUS
1453 This option allows the use of multiple I2C buses, each of which
1454 must have a controller. At any point in time, only one bus is
1455 active. To switch to a different bus, use the 'i2c dev' command.
1456 Note that bus numbering is zero-based.
1458 CONFIG_SYS_I2C_NOPROBES
1460 This option specifies a list of I2C devices that will be skipped
1461 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS
1462 is set, specify a list of bus-device pairs. Otherwise, specify
1463 a 1D array of device addresses
1466 #undef CONFIG_I2C_MULTI_BUS
1467 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68}
1469 will skip addresses 0x50 and 0x68 on a board with one I2C bus
1471 #define CONFIG_I2C_MULTI_BUS
1472 #define CONFIG_SYS_I2C_MULTI_NOPROBES {{0,0x50},{0,0x68},{1,0x54}}
1474 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1
1476 CONFIG_SYS_SPD_BUS_NUM
1478 If defined, then this indicates the I2C bus number for DDR SPD.
1479 If not defined, then U-Boot assumes that SPD is on I2C bus 0.
1481 CONFIG_SYS_RTC_BUS_NUM
1483 If defined, then this indicates the I2C bus number for the RTC.
1484 If not defined, then U-Boot assumes that RTC is on I2C bus 0.
1486 CONFIG_SYS_DTT_BUS_NUM
1488 If defined, then this indicates the I2C bus number for the DTT.
1489 If not defined, then U-Boot assumes that DTT is on I2C bus 0.
1491 CONFIG_SYS_I2C_DTT_ADDR:
1493 If defined, specifies the I2C address of the DTT device.
1494 If not defined, then U-Boot uses predefined value for
1495 specified DTT device.
1499 Define this option if you want to use Freescale's I2C driver in
1500 drivers/i2c/fsl_i2c.c.
1504 Define this option if you have I2C devices reached over 1 .. n
1505 I2C Muxes like the pca9544a. This option addes a new I2C
1506 Command "i2c bus [muxtype:muxaddr:muxchannel]" which adds a
1507 new I2C Bus to the existing I2C Busses. If you select the
1508 new Bus with "i2c dev", u-bbot sends first the commandos for
1509 the muxes to activate this new "bus".
1511 CONFIG_I2C_MULTI_BUS must be also defined, to use this
1515 Adding a new I2C Bus reached over 2 pca9544a muxes
1516 The First mux with address 70 and channel 6
1517 The Second mux with address 71 and channel 4
1519 => i2c bus pca9544a:70:6:pca9544a:71:4
1521 Use the "i2c bus" command without parameter, to get a list
1522 of I2C Busses with muxes:
1525 Busses reached over muxes:
1527 reached over Mux(es):
1530 reached over Mux(es):
1535 If you now switch to the new I2C Bus 3 with "i2c dev 3"
1536 u-boot sends First the Commando to the mux@70 to enable
1537 channel 6, and then the Commando to the mux@71 to enable
1540 After that, you can use the "normal" i2c commands as
1541 usual, to communicate with your I2C devices behind
1544 This option is actually implemented for the bitbanging
1545 algorithm in common/soft_i2c.c and for the Hardware I2C
1546 Bus on the MPC8260. But it should be not so difficult
1547 to add this option to other architectures.
1549 CONFIG_SOFT_I2C_READ_REPEATED_START
1551 defining this will force the i2c_read() function in
1552 the soft_i2c driver to perform an I2C repeated start
1553 between writing the address pointer and reading the
1554 data. If this define is omitted the default behaviour
1555 of doing a stop-start sequence will be used. Most I2C
1556 devices can use either method, but some require one or
1559 - SPI Support: CONFIG_SPI
1561 Enables SPI driver (so far only tested with
1562 SPI EEPROM, also an instance works with Crystal A/D and
1563 D/As on the SACSng board)
1567 Enables extended (16-bit) SPI EEPROM addressing.
1568 (symmetrical to CONFIG_I2C_X)
1572 Enables a software (bit-bang) SPI driver rather than
1573 using hardware support. This is a general purpose
1574 driver that only requires three general I/O port pins
1575 (two outputs, one input) to function. If this is
1576 defined, the board configuration must define several
1577 SPI configuration items (port pins to use, etc). For
1578 an example, see include/configs/sacsng.h.
1582 Enables a hardware SPI driver for general-purpose reads
1583 and writes. As with CONFIG_SOFT_SPI, the board configuration
1584 must define a list of chip-select function pointers.
1585 Currently supported on some MPC8xxx processors. For an
1586 example, see include/configs/mpc8349emds.h.
1590 Enables the driver for the SPI controllers on i.MX and MXC
1591 SoCs. Currently only i.MX31 is supported.
1593 - FPGA Support: CONFIG_FPGA
1595 Enables FPGA subsystem.
1597 CONFIG_FPGA_<vendor>
1599 Enables support for specific chip vendors.
1602 CONFIG_FPGA_<family>
1604 Enables support for FPGA family.
1605 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX)
1609 Specify the number of FPGA devices to support.
1611 CONFIG_SYS_FPGA_PROG_FEEDBACK
1613 Enable printing of hash marks during FPGA configuration.
1615 CONFIG_SYS_FPGA_CHECK_BUSY
1617 Enable checks on FPGA configuration interface busy
1618 status by the configuration function. This option
1619 will require a board or device specific function to
1624 If defined, a function that provides delays in the FPGA
1625 configuration driver.
1627 CONFIG_SYS_FPGA_CHECK_CTRLC
1628 Allow Control-C to interrupt FPGA configuration
1630 CONFIG_SYS_FPGA_CHECK_ERROR
1632 Check for configuration errors during FPGA bitfile
1633 loading. For example, abort during Virtex II
1634 configuration if the INIT_B line goes low (which
1635 indicated a CRC error).
1637 CONFIG_SYS_FPGA_WAIT_INIT
1639 Maximum time to wait for the INIT_B line to deassert
1640 after PROB_B has been deasserted during a Virtex II
1641 FPGA configuration sequence. The default time is 500
1644 CONFIG_SYS_FPGA_WAIT_BUSY
1646 Maximum time to wait for BUSY to deassert during
1647 Virtex II FPGA configuration. The default is 5 ms.
1649 CONFIG_SYS_FPGA_WAIT_CONFIG
1651 Time to wait after FPGA configuration. The default is
1654 - Configuration Management:
1657 If defined, this string will be added to the U-Boot
1658 version information (U_BOOT_VERSION)
1660 - Vendor Parameter Protection:
1662 U-Boot considers the values of the environment
1663 variables "serial#" (Board Serial Number) and
1664 "ethaddr" (Ethernet Address) to be parameters that
1665 are set once by the board vendor / manufacturer, and
1666 protects these variables from casual modification by
1667 the user. Once set, these variables are read-only,
1668 and write or delete attempts are rejected. You can
1669 change this behaviour:
1671 If CONFIG_ENV_OVERWRITE is #defined in your config
1672 file, the write protection for vendor parameters is
1673 completely disabled. Anybody can change or delete
1676 Alternatively, if you #define _both_ CONFIG_ETHADDR
1677 _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
1678 Ethernet address is installed in the environment,
1679 which can be changed exactly ONCE by the user. [The
1680 serial# is unaffected by this, i. e. it remains
1686 Define this variable to enable the reservation of
1687 "protected RAM", i. e. RAM which is not overwritten
1688 by U-Boot. Define CONFIG_PRAM to hold the number of
1689 kB you want to reserve for pRAM. You can overwrite
1690 this default value by defining an environment
1691 variable "pram" to the number of kB you want to
1692 reserve. Note that the board info structure will
1693 still show the full amount of RAM. If pRAM is
1694 reserved, a new environment variable "mem" will
1695 automatically be defined to hold the amount of
1696 remaining RAM in a form that can be passed as boot
1697 argument to Linux, for instance like that:
1699 setenv bootargs ... mem=\${mem}
1702 This way you can tell Linux not to use this memory,
1703 either, which results in a memory region that will
1704 not be affected by reboots.
1706 *WARNING* If your board configuration uses automatic
1707 detection of the RAM size, you must make sure that
1708 this memory test is non-destructive. So far, the
1709 following board configurations are known to be
1712 ETX094, IVMS8, IVML24, SPD8xx, TQM8xxL,
1713 HERMES, IP860, RPXlite, LWMON, LANTEC,
1714 PCU_E, FLAGADM, TQM8260
1719 Define this variable to stop the system in case of a
1720 fatal error, so that you have to reset it manually.
1721 This is probably NOT a good idea for an embedded
1722 system where you want the system to reboot
1723 automatically as fast as possible, but it may be
1724 useful during development since you can try to debug
1725 the conditions that lead to the situation.
1727 CONFIG_NET_RETRY_COUNT
1729 This variable defines the number of retries for
1730 network operations like ARP, RARP, TFTP, or BOOTP
1731 before giving up the operation. If not defined, a
1732 default value of 5 is used.
1736 Timeout waiting for an ARP reply in milliseconds.
1738 - Command Interpreter:
1739 CONFIG_AUTO_COMPLETE
1741 Enable auto completion of commands using TAB.
1743 Note that this feature has NOT been implemented yet
1744 for the "hush" shell.
1747 CONFIG_SYS_HUSH_PARSER
1749 Define this variable to enable the "hush" shell (from
1750 Busybox) as command line interpreter, thus enabling
1751 powerful command line syntax like
1752 if...then...else...fi conditionals or `&&' and '||'
1753 constructs ("shell scripts").
1755 If undefined, you get the old, much simpler behaviour
1756 with a somewhat smaller memory footprint.
1759 CONFIG_SYS_PROMPT_HUSH_PS2
1761 This defines the secondary prompt string, which is
1762 printed when the command interpreter needs more input
1763 to complete a command. Usually "> ".
1767 In the current implementation, the local variables
1768 space and global environment variables space are
1769 separated. Local variables are those you define by
1770 simply typing `name=value'. To access a local
1771 variable later on, you have write `$name' or
1772 `${name}'; to execute the contents of a variable
1773 directly type `$name' at the command prompt.
1775 Global environment variables are those you use
1776 setenv/printenv to work with. To run a command stored
1777 in such a variable, you need to use the run command,
1778 and you must not use the '$' sign to access them.
1780 To store commands and special characters in a
1781 variable, please use double quotation marks
1782 surrounding the whole text of the variable, instead
1783 of the backslashes before semicolons and special
1786 - Commandline Editing and History:
1787 CONFIG_CMDLINE_EDITING
1789 Enable editing and History functions for interactive
1790 commandline input operations
1792 - Default Environment:
1793 CONFIG_EXTRA_ENV_SETTINGS
1795 Define this to contain any number of null terminated
1796 strings (variable = value pairs) that will be part of
1797 the default environment compiled into the boot image.
1799 For example, place something like this in your
1800 board's config file:
1802 #define CONFIG_EXTRA_ENV_SETTINGS \
1806 Warning: This method is based on knowledge about the
1807 internal format how the environment is stored by the
1808 U-Boot code. This is NOT an official, exported
1809 interface! Although it is unlikely that this format
1810 will change soon, there is no guarantee either.
1811 You better know what you are doing here.
1813 Note: overly (ab)use of the default environment is
1814 discouraged. Make sure to check other ways to preset
1815 the environment like the "source" command or the
1818 - DataFlash Support:
1819 CONFIG_HAS_DATAFLASH
1821 Defining this option enables DataFlash features and
1822 allows to read/write in Dataflash via the standard
1825 - SystemACE Support:
1828 Adding this option adds support for Xilinx SystemACE
1829 chips attached via some sort of local bus. The address
1830 of the chip must also be defined in the
1831 CONFIG_SYS_SYSTEMACE_BASE macro. For example:
1833 #define CONFIG_SYSTEMACE
1834 #define CONFIG_SYS_SYSTEMACE_BASE 0xf0000000
1836 When SystemACE support is added, the "ace" device type
1837 becomes available to the fat commands, i.e. fatls.
1839 - TFTP Fixed UDP Port:
1842 If this is defined, the environment variable tftpsrcp
1843 is used to supply the TFTP UDP source port value.
1844 If tftpsrcp isn't defined, the normal pseudo-random port
1845 number generator is used.
1847 Also, the environment variable tftpdstp is used to supply
1848 the TFTP UDP destination port value. If tftpdstp isn't
1849 defined, the normal port 69 is used.
1851 The purpose for tftpsrcp is to allow a TFTP server to
1852 blindly start the TFTP transfer using the pre-configured
1853 target IP address and UDP port. This has the effect of
1854 "punching through" the (Windows XP) firewall, allowing
1855 the remainder of the TFTP transfer to proceed normally.
1856 A better solution is to properly configure the firewall,
1857 but sometimes that is not allowed.
1859 - Show boot progress:
1860 CONFIG_SHOW_BOOT_PROGRESS
1862 Defining this option allows to add some board-
1863 specific code (calling a user-provided function
1864 "show_boot_progress(int)") that enables you to show
1865 the system's boot progress on some display (for
1866 example, some LED's) on your board. At the moment,
1867 the following checkpoints are implemented:
1869 - Automatic software updates via TFTP server
1871 CONFIG_UPDATE_TFTP_CNT_MAX
1872 CONFIG_UPDATE_TFTP_MSEC_MAX
1874 These options enable and control the auto-update feature;
1875 for a more detailed description refer to doc/README.update.
1877 - MTD Support (mtdparts command, UBI support)
1880 Adds the MTD device infrastructure from the Linux kernel.
1881 Needed for mtdparts command support.
1883 CONFIG_MTD_PARTITIONS
1885 Adds the MTD partitioning infrastructure from the Linux
1886 kernel. Needed for UBI support.
1888 Legacy uImage format:
1891 1 common/cmd_bootm.c before attempting to boot an image
1892 -1 common/cmd_bootm.c Image header has bad magic number
1893 2 common/cmd_bootm.c Image header has correct magic number
1894 -2 common/cmd_bootm.c Image header has bad checksum
1895 3 common/cmd_bootm.c Image header has correct checksum
1896 -3 common/cmd_bootm.c Image data has bad checksum
1897 4 common/cmd_bootm.c Image data has correct checksum
1898 -4 common/cmd_bootm.c Image is for unsupported architecture
1899 5 common/cmd_bootm.c Architecture check OK
1900 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi)
1901 6 common/cmd_bootm.c Image Type check OK
1902 -6 common/cmd_bootm.c gunzip uncompression error
1903 -7 common/cmd_bootm.c Unimplemented compression type
1904 7 common/cmd_bootm.c Uncompression OK
1905 8 common/cmd_bootm.c No uncompress/copy overwrite error
1906 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX)
1908 9 common/image.c Start initial ramdisk verification
1909 -10 common/image.c Ramdisk header has bad magic number
1910 -11 common/image.c Ramdisk header has bad checksum
1911 10 common/image.c Ramdisk header is OK
1912 -12 common/image.c Ramdisk data has bad checksum
1913 11 common/image.c Ramdisk data has correct checksum
1914 12 common/image.c Ramdisk verification complete, start loading
1915 -13 common/image.c Wrong Image Type (not PPC Linux ramdisk)
1916 13 common/image.c Start multifile image verification
1917 14 common/image.c No initial ramdisk, no multifile, continue.
1919 15 lib_<arch>/bootm.c All preparation done, transferring control to OS
1921 -30 lib_ppc/board.c Fatal error, hang the system
1922 -31 post/post.c POST test failed, detected by post_output_backlog()
1923 -32 post/post.c POST test failed, detected by post_run_single()
1925 34 common/cmd_doc.c before loading a Image from a DOC device
1926 -35 common/cmd_doc.c Bad usage of "doc" command
1927 35 common/cmd_doc.c correct usage of "doc" command
1928 -36 common/cmd_doc.c No boot device
1929 36 common/cmd_doc.c correct boot device
1930 -37 common/cmd_doc.c Unknown Chip ID on boot device
1931 37 common/cmd_doc.c correct chip ID found, device available
1932 -38 common/cmd_doc.c Read Error on boot device
1933 38 common/cmd_doc.c reading Image header from DOC device OK
1934 -39 common/cmd_doc.c Image header has bad magic number
1935 39 common/cmd_doc.c Image header has correct magic number
1936 -40 common/cmd_doc.c Error reading Image from DOC device
1937 40 common/cmd_doc.c Image header has correct magic number
1938 41 common/cmd_ide.c before loading a Image from a IDE device
1939 -42 common/cmd_ide.c Bad usage of "ide" command
1940 42 common/cmd_ide.c correct usage of "ide" command
1941 -43 common/cmd_ide.c No boot device
1942 43 common/cmd_ide.c boot device found
1943 -44 common/cmd_ide.c Device not available
1944 44 common/cmd_ide.c Device available
1945 -45 common/cmd_ide.c wrong partition selected
1946 45 common/cmd_ide.c partition selected
1947 -46 common/cmd_ide.c Unknown partition table
1948 46 common/cmd_ide.c valid partition table found
1949 -47 common/cmd_ide.c Invalid partition type
1950 47 common/cmd_ide.c correct partition type
1951 -48 common/cmd_ide.c Error reading Image Header on boot device
1952 48 common/cmd_ide.c reading Image Header from IDE device OK
1953 -49 common/cmd_ide.c Image header has bad magic number
1954 49 common/cmd_ide.c Image header has correct magic number
1955 -50 common/cmd_ide.c Image header has bad checksum
1956 50 common/cmd_ide.c Image header has correct checksum
1957 -51 common/cmd_ide.c Error reading Image from IDE device
1958 51 common/cmd_ide.c reading Image from IDE device OK
1959 52 common/cmd_nand.c before loading a Image from a NAND device
1960 -53 common/cmd_nand.c Bad usage of "nand" command
1961 53 common/cmd_nand.c correct usage of "nand" command
1962 -54 common/cmd_nand.c No boot device
1963 54 common/cmd_nand.c boot device found
1964 -55 common/cmd_nand.c Unknown Chip ID on boot device
1965 55 common/cmd_nand.c correct chip ID found, device available
1966 -56 common/cmd_nand.c Error reading Image Header on boot device
1967 56 common/cmd_nand.c reading Image Header from NAND device OK
1968 -57 common/cmd_nand.c Image header has bad magic number
1969 57 common/cmd_nand.c Image header has correct magic number
1970 -58 common/cmd_nand.c Error reading Image from NAND device
1971 58 common/cmd_nand.c reading Image from NAND device OK
1973 -60 common/env_common.c Environment has a bad CRC, using default
1975 64 net/eth.c starting with Ethernet configuration.
1976 -64 net/eth.c no Ethernet found.
1977 65 net/eth.c Ethernet found.
1979 -80 common/cmd_net.c usage wrong
1980 80 common/cmd_net.c before calling NetLoop()
1981 -81 common/cmd_net.c some error in NetLoop() occurred
1982 81 common/cmd_net.c NetLoop() back without error
1983 -82 common/cmd_net.c size == 0 (File with size 0 loaded)
1984 82 common/cmd_net.c trying automatic boot
1985 83 common/cmd_net.c running "source" command
1986 -83 common/cmd_net.c some error in automatic boot or "source" command
1987 84 common/cmd_net.c end without errors
1992 100 common/cmd_bootm.c Kernel FIT Image has correct format
1993 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format
1994 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration
1995 -101 common/cmd_bootm.c Can't get configuration for kernel subimage
1996 102 common/cmd_bootm.c Kernel unit name specified
1997 -103 common/cmd_bootm.c Can't get kernel subimage node offset
1998 103 common/cmd_bootm.c Found configuration node
1999 104 common/cmd_bootm.c Got kernel subimage node offset
2000 -104 common/cmd_bootm.c Kernel subimage hash verification failed
2001 105 common/cmd_bootm.c Kernel subimage hash verification OK
2002 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture
2003 106 common/cmd_bootm.c Architecture check OK
2004 -106 common/cmd_bootm.c Kernel subimage has wrong type
2005 107 common/cmd_bootm.c Kernel subimage type OK
2006 -107 common/cmd_bootm.c Can't get kernel subimage data/size
2007 108 common/cmd_bootm.c Got kernel subimage data/size
2008 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT)
2009 -109 common/cmd_bootm.c Can't get kernel subimage type
2010 -110 common/cmd_bootm.c Can't get kernel subimage comp
2011 -111 common/cmd_bootm.c Can't get kernel subimage os
2012 -112 common/cmd_bootm.c Can't get kernel subimage load address
2013 -113 common/cmd_bootm.c Image uncompress/copy overwrite error
2015 120 common/image.c Start initial ramdisk verification
2016 -120 common/image.c Ramdisk FIT image has incorrect format
2017 121 common/image.c Ramdisk FIT image has correct format
2018 122 common/image.c No ramdisk subimage unit name, using configuration
2019 -122 common/image.c Can't get configuration for ramdisk subimage
2020 123 common/image.c Ramdisk unit name specified
2021 -124 common/image.c Can't get ramdisk subimage node offset
2022 125 common/image.c Got ramdisk subimage node offset
2023 -125 common/image.c Ramdisk subimage hash verification failed
2024 126 common/image.c Ramdisk subimage hash verification OK
2025 -126 common/image.c Ramdisk subimage for unsupported architecture
2026 127 common/image.c Architecture check OK
2027 -127 common/image.c Can't get ramdisk subimage data/size
2028 128 common/image.c Got ramdisk subimage data/size
2029 129 common/image.c Can't get ramdisk load address
2030 -129 common/image.c Got ramdisk load address
2032 -130 common/cmd_doc.c Incorrect FIT image format
2033 131 common/cmd_doc.c FIT image format OK
2035 -140 common/cmd_ide.c Incorrect FIT image format
2036 141 common/cmd_ide.c FIT image format OK
2038 -150 common/cmd_nand.c Incorrect FIT image format
2039 151 common/cmd_nand.c FIT image format OK
2045 [so far only for SMDK2400 and TRAB boards]
2047 - Modem support enable:
2048 CONFIG_MODEM_SUPPORT
2050 - RTS/CTS Flow control enable:
2053 - Modem debug support:
2054 CONFIG_MODEM_SUPPORT_DEBUG
2056 Enables debugging stuff (char screen[1024], dbg())
2057 for modem support. Useful only with BDI2000.
2059 - Interrupt support (PPC):
2061 There are common interrupt_init() and timer_interrupt()
2062 for all PPC archs. interrupt_init() calls interrupt_init_cpu()
2063 for CPU specific initialization. interrupt_init_cpu()
2064 should set decrementer_count to appropriate value. If
2065 CPU resets decrementer automatically after interrupt
2066 (ppc4xx) it should set decrementer_count to zero.
2067 timer_interrupt() calls timer_interrupt_cpu() for CPU
2068 specific handling. If board has watchdog / status_led
2069 / other_activity_monitor it works automatically from
2070 general timer_interrupt().
2074 In the target system modem support is enabled when a
2075 specific key (key combination) is pressed during
2076 power-on. Otherwise U-Boot will boot normally
2077 (autoboot). The key_pressed() function is called from
2078 board_init(). Currently key_pressed() is a dummy
2079 function, returning 1 and thus enabling modem
2082 If there are no modem init strings in the
2083 environment, U-Boot proceed to autoboot; the
2084 previous output (banner, info printfs) will be
2087 See also: doc/README.Modem
2090 Configuration Settings:
2091 -----------------------
2093 - CONFIG_SYS_LONGHELP: Defined when you want long help messages included;
2094 undefine this when you're short of memory.
2096 - CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default
2097 width of the commands listed in the 'help' command output.
2099 - CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to
2100 prompt for user input.
2102 - CONFIG_SYS_CBSIZE: Buffer size for input from the Console
2104 - CONFIG_SYS_PBSIZE: Buffer size for Console output
2106 - CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands
2108 - CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to
2109 the application (usually a Linux kernel) when it is
2112 - CONFIG_SYS_BAUDRATE_TABLE:
2113 List of legal baudrate settings for this board.
2115 - CONFIG_SYS_CONSOLE_INFO_QUIET
2116 Suppress display of console information at boot.
2118 - CONFIG_SYS_CONSOLE_IS_IN_ENV
2119 If the board specific function
2120 extern int overwrite_console (void);
2121 returns 1, the stdin, stderr and stdout are switched to the
2122 serial port, else the settings in the environment are used.
2124 - CONFIG_SYS_CONSOLE_OVERWRITE_ROUTINE
2125 Enable the call to overwrite_console().
2127 - CONFIG_SYS_CONSOLE_ENV_OVERWRITE
2128 Enable overwrite of previous console environment settings.
2130 - CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END:
2131 Begin and End addresses of the area used by the
2134 - CONFIG_SYS_ALT_MEMTEST:
2135 Enable an alternate, more extensive memory test.
2137 - CONFIG_SYS_MEMTEST_SCRATCH:
2138 Scratch address used by the alternate memory test
2139 You only need to set this if address zero isn't writeable
2141 - CONFIG_SYS_MEM_TOP_HIDE (PPC only):
2142 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header,
2143 this specified memory area will get subtracted from the top
2144 (end) of RAM and won't get "touched" at all by U-Boot. By
2145 fixing up gd->ram_size the Linux kernel should gets passed
2146 the now "corrected" memory size and won't touch it either.
2147 This should work for arch/ppc and arch/powerpc. Only Linux
2148 board ports in arch/powerpc with bootwrapper support that
2149 recalculate the memory size from the SDRAM controller setup
2150 will have to get fixed in Linux additionally.
2152 This option can be used as a workaround for the 440EPx/GRx
2153 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't
2156 WARNING: Please make sure that this value is a multiple of
2157 the Linux page size (normally 4k). If this is not the case,
2158 then the end address of the Linux memory will be located at a
2159 non page size aligned address and this could cause major
2162 - CONFIG_SYS_TFTP_LOADADDR:
2163 Default load address for network file downloads
2165 - CONFIG_SYS_LOADS_BAUD_CHANGE:
2166 Enable temporary baudrate change while serial download
2168 - CONFIG_SYS_SDRAM_BASE:
2169 Physical start address of SDRAM. _Must_ be 0 here.
2171 - CONFIG_SYS_MBIO_BASE:
2172 Physical start address of Motherboard I/O (if using a
2175 - CONFIG_SYS_FLASH_BASE:
2176 Physical start address of Flash memory.
2178 - CONFIG_SYS_MONITOR_BASE:
2179 Physical start address of boot monitor code (set by
2180 make config files to be same as the text base address
2181 (TEXT_BASE) used when linking) - same as
2182 CONFIG_SYS_FLASH_BASE when booting from flash.
2184 - CONFIG_SYS_MONITOR_LEN:
2185 Size of memory reserved for monitor code, used to
2186 determine _at_compile_time_ (!) if the environment is
2187 embedded within the U-Boot image, or in a separate
2190 - CONFIG_SYS_MALLOC_LEN:
2191 Size of DRAM reserved for malloc() use.
2193 - CONFIG_SYS_BOOTM_LEN:
2194 Normally compressed uImages are limited to an
2195 uncompressed size of 8 MBytes. If this is not enough,
2196 you can define CONFIG_SYS_BOOTM_LEN in your board config file
2197 to adjust this setting to your needs.
2199 - CONFIG_SYS_BOOTMAPSZ:
2200 Maximum size of memory mapped by the startup code of
2201 the Linux kernel; all data that must be processed by
2202 the Linux kernel (bd_info, boot arguments, FDT blob if
2203 used) must be put below this limit, unless "bootm_low"
2204 enviroment variable is defined and non-zero. In such case
2205 all data for the Linux kernel must be between "bootm_low"
2206 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ.
2208 - CONFIG_SYS_MAX_FLASH_BANKS:
2209 Max number of Flash memory banks
2211 - CONFIG_SYS_MAX_FLASH_SECT:
2212 Max number of sectors on a Flash chip
2214 - CONFIG_SYS_FLASH_ERASE_TOUT:
2215 Timeout for Flash erase operations (in ms)
2217 - CONFIG_SYS_FLASH_WRITE_TOUT:
2218 Timeout for Flash write operations (in ms)
2220 - CONFIG_SYS_FLASH_LOCK_TOUT
2221 Timeout for Flash set sector lock bit operation (in ms)
2223 - CONFIG_SYS_FLASH_UNLOCK_TOUT
2224 Timeout for Flash clear lock bits operation (in ms)
2226 - CONFIG_SYS_FLASH_PROTECTION
2227 If defined, hardware flash sectors protection is used
2228 instead of U-Boot software protection.
2230 - CONFIG_SYS_DIRECT_FLASH_TFTP:
2232 Enable TFTP transfers directly to flash memory;
2233 without this option such a download has to be
2234 performed in two steps: (1) download to RAM, and (2)
2235 copy from RAM to flash.
2237 The two-step approach is usually more reliable, since
2238 you can check if the download worked before you erase
2239 the flash, but in some situations (when system RAM is
2240 too limited to allow for a temporary copy of the
2241 downloaded image) this option may be very useful.
2243 - CONFIG_SYS_FLASH_CFI:
2244 Define if the flash driver uses extra elements in the
2245 common flash structure for storing flash geometry.
2247 - CONFIG_FLASH_CFI_DRIVER
2248 This option also enables the building of the cfi_flash driver
2249 in the drivers directory
2251 - CONFIG_FLASH_CFI_MTD
2252 This option enables the building of the cfi_mtd driver
2253 in the drivers directory. The driver exports CFI flash
2256 - CONFIG_SYS_FLASH_USE_BUFFER_WRITE
2257 Use buffered writes to flash.
2259 - CONFIG_FLASH_SPANSION_S29WS_N
2260 s29ws-n MirrorBit flash has non-standard addresses for buffered
2263 - CONFIG_SYS_FLASH_QUIET_TEST
2264 If this option is defined, the common CFI flash doesn't
2265 print it's warning upon not recognized FLASH banks. This
2266 is useful, if some of the configured banks are only
2267 optionally available.
2269 - CONFIG_FLASH_SHOW_PROGRESS
2270 If defined (must be an integer), print out countdown
2271 digits and dots. Recommended value: 45 (9..1) for 80
2272 column displays, 15 (3..1) for 40 column displays.
2274 - CONFIG_SYS_RX_ETH_BUFFER:
2275 Defines the number of Ethernet receive buffers. On some
2276 Ethernet controllers it is recommended to set this value
2277 to 8 or even higher (EEPRO100 or 405 EMAC), since all
2278 buffers can be full shortly after enabling the interface
2279 on high Ethernet traffic.
2280 Defaults to 4 if not defined.
2282 The following definitions that deal with the placement and management
2283 of environment data (variable area); in general, we support the
2284 following configurations:
2286 - CONFIG_ENV_IS_IN_FLASH:
2288 Define this if the environment is in flash memory.
2290 a) The environment occupies one whole flash sector, which is
2291 "embedded" in the text segment with the U-Boot code. This
2292 happens usually with "bottom boot sector" or "top boot
2293 sector" type flash chips, which have several smaller
2294 sectors at the start or the end. For instance, such a
2295 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In
2296 such a case you would place the environment in one of the
2297 4 kB sectors - with U-Boot code before and after it. With
2298 "top boot sector" type flash chips, you would put the
2299 environment in one of the last sectors, leaving a gap
2300 between U-Boot and the environment.
2302 - CONFIG_ENV_OFFSET:
2304 Offset of environment data (variable area) to the
2305 beginning of flash memory; for instance, with bottom boot
2306 type flash chips the second sector can be used: the offset
2307 for this sector is given here.
2309 CONFIG_ENV_OFFSET is used relative to CONFIG_SYS_FLASH_BASE.
2313 This is just another way to specify the start address of
2314 the flash sector containing the environment (instead of
2317 - CONFIG_ENV_SECT_SIZE:
2319 Size of the sector containing the environment.
2322 b) Sometimes flash chips have few, equal sized, BIG sectors.
2323 In such a case you don't want to spend a whole sector for
2328 If you use this in combination with CONFIG_ENV_IS_IN_FLASH
2329 and CONFIG_ENV_SECT_SIZE, you can specify to use only a part
2330 of this flash sector for the environment. This saves
2331 memory for the RAM copy of the environment.
2333 It may also save flash memory if you decide to use this
2334 when your environment is "embedded" within U-Boot code,
2335 since then the remainder of the flash sector could be used
2336 for U-Boot code. It should be pointed out that this is
2337 STRONGLY DISCOURAGED from a robustness point of view:
2338 updating the environment in flash makes it always
2339 necessary to erase the WHOLE sector. If something goes
2340 wrong before the contents has been restored from a copy in
2341 RAM, your target system will be dead.
2343 - CONFIG_ENV_ADDR_REDUND
2344 CONFIG_ENV_SIZE_REDUND
2346 These settings describe a second storage area used to hold
2347 a redundant copy of the environment data, so that there is
2348 a valid backup copy in case there is a power failure during
2349 a "saveenv" operation.
2351 BE CAREFUL! Any changes to the flash layout, and some changes to the
2352 source code will make it necessary to adapt <board>/u-boot.lds*
2356 - CONFIG_ENV_IS_IN_NVRAM:
2358 Define this if you have some non-volatile memory device
2359 (NVRAM, battery buffered SRAM) which you want to use for the
2365 These two #defines are used to determine the memory area you
2366 want to use for environment. It is assumed that this memory
2367 can just be read and written to, without any special
2370 BE CAREFUL! The first access to the environment happens quite early
2371 in U-Boot initalization (when we try to get the setting of for the
2372 console baudrate). You *MUST* have mapped your NVRAM area then, or
2375 Please note that even with NVRAM we still use a copy of the
2376 environment in RAM: we could work on NVRAM directly, but we want to
2377 keep settings there always unmodified except somebody uses "saveenv"
2378 to save the current settings.
2381 - CONFIG_ENV_IS_IN_EEPROM:
2383 Use this if you have an EEPROM or similar serial access
2384 device and a driver for it.
2386 - CONFIG_ENV_OFFSET:
2389 These two #defines specify the offset and size of the
2390 environment area within the total memory of your EEPROM.
2392 - CONFIG_SYS_I2C_EEPROM_ADDR:
2393 If defined, specified the chip address of the EEPROM device.
2394 The default address is zero.
2396 - CONFIG_SYS_EEPROM_PAGE_WRITE_BITS:
2397 If defined, the number of bits used to address bytes in a
2398 single page in the EEPROM device. A 64 byte page, for example
2399 would require six bits.
2401 - CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS:
2402 If defined, the number of milliseconds to delay between
2403 page writes. The default is zero milliseconds.
2405 - CONFIG_SYS_I2C_EEPROM_ADDR_LEN:
2406 The length in bytes of the EEPROM memory array address. Note
2407 that this is NOT the chip address length!
2409 - CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW:
2410 EEPROM chips that implement "address overflow" are ones
2411 like Catalyst 24WC04/08/16 which has 9/10/11 bits of
2412 address and the extra bits end up in the "chip address" bit
2413 slots. This makes a 24WC08 (1Kbyte) chip look like four 256
2416 Note that we consider the length of the address field to
2417 still be one byte because the extra address bits are hidden
2418 in the chip address.
2420 - CONFIG_SYS_EEPROM_SIZE:
2421 The size in bytes of the EEPROM device.
2424 - CONFIG_ENV_IS_IN_DATAFLASH:
2426 Define this if you have a DataFlash memory device which you
2427 want to use for the environment.
2429 - CONFIG_ENV_OFFSET:
2433 These three #defines specify the offset and size of the
2434 environment area within the total memory of your DataFlash placed
2435 at the specified address.
2437 - CONFIG_ENV_IS_IN_NAND:
2439 Define this if you have a NAND device which you want to use
2440 for the environment.
2442 - CONFIG_ENV_OFFSET:
2445 These two #defines specify the offset and size of the environment
2446 area within the first NAND device.
2448 - CONFIG_ENV_OFFSET_REDUND
2450 This setting describes a second storage area of CONFIG_ENV_SIZE
2451 size used to hold a redundant copy of the environment data,
2452 so that there is a valid backup copy in case there is a
2453 power failure during a "saveenv" operation.
2455 Note: CONFIG_ENV_OFFSET and CONFIG_ENV_OFFSET_REDUND must be aligned
2456 to a block boundary, and CONFIG_ENV_SIZE must be a multiple of
2457 the NAND devices block size.
2459 - CONFIG_NAND_ENV_DST
2461 Defines address in RAM to which the nand_spl code should copy the
2462 environment. If redundant environment is used, it will be copied to
2463 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE.
2465 - CONFIG_SYS_SPI_INIT_OFFSET
2467 Defines offset to the initial SPI buffer area in DPRAM. The
2468 area is used at an early stage (ROM part) if the environment
2469 is configured to reside in the SPI EEPROM: We need a 520 byte
2470 scratch DPRAM area. It is used between the two initialization
2471 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems
2472 to be a good choice since it makes it far enough from the
2473 start of the data area as well as from the stack pointer.
2475 Please note that the environment is read-only until the monitor
2476 has been relocated to RAM and a RAM copy of the environment has been
2477 created; also, when using EEPROM you will have to use getenv_r()
2478 until then to read environment variables.
2480 The environment is protected by a CRC32 checksum. Before the monitor
2481 is relocated into RAM, as a result of a bad CRC you will be working
2482 with the compiled-in default environment - *silently*!!! [This is
2483 necessary, because the first environment variable we need is the
2484 "baudrate" setting for the console - if we have a bad CRC, we don't
2485 have any device yet where we could complain.]
2487 Note: once the monitor has been relocated, then it will complain if
2488 the default environment is used; a new CRC is computed as soon as you
2489 use the "saveenv" command to store a valid environment.
2491 - CONFIG_SYS_FAULT_ECHO_LINK_DOWN:
2492 Echo the inverted Ethernet link state to the fault LED.
2494 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR
2495 also needs to be defined.
2497 - CONFIG_SYS_FAULT_MII_ADDR:
2498 MII address of the PHY to check for the Ethernet link state.
2500 - CONFIG_SYS_64BIT_VSPRINTF:
2501 Makes vsprintf (and all *printf functions) support printing
2502 of 64bit values by using the L quantifier
2504 - CONFIG_SYS_64BIT_STRTOUL:
2505 Adds simple_strtoull that returns a 64bit value
2507 - CONFIG_NS16550_MIN_FUNCTIONS:
2508 Define this if you desire to only have use of the NS16550_init
2509 and NS16550_putc functions for the serial driver located at
2510 drivers/serial/ns16550.c. This option is useful for saving
2511 space for already greatly restricted images, including but not
2512 limited to NAND_SPL configurations.
2514 Low Level (hardware related) configuration options:
2515 ---------------------------------------------------
2517 - CONFIG_SYS_CACHELINE_SIZE:
2518 Cache Line Size of the CPU.
2520 - CONFIG_SYS_DEFAULT_IMMR:
2521 Default address of the IMMR after system reset.
2523 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU,
2524 and RPXsuper) to be able to adjust the position of
2525 the IMMR register after a reset.
2527 - Floppy Disk Support:
2528 CONFIG_SYS_FDC_DRIVE_NUMBER
2530 the default drive number (default value 0)
2532 CONFIG_SYS_ISA_IO_STRIDE
2534 defines the spacing between FDC chipset registers
2537 CONFIG_SYS_ISA_IO_OFFSET
2539 defines the offset of register from address. It
2540 depends on which part of the data bus is connected to
2541 the FDC chipset. (default value 0)
2543 If CONFIG_SYS_ISA_IO_STRIDE CONFIG_SYS_ISA_IO_OFFSET and
2544 CONFIG_SYS_FDC_DRIVE_NUMBER are undefined, they take their
2547 if CONFIG_SYS_FDC_HW_INIT is defined, then the function
2548 fdc_hw_init() is called at the beginning of the FDC
2549 setup. fdc_hw_init() must be provided by the board
2550 source code. It is used to make hardware dependant
2553 - CONFIG_SYS_IMMR: Physical address of the Internal Memory.
2554 DO NOT CHANGE unless you know exactly what you're
2555 doing! (11-4) [MPC8xx/82xx systems only]
2557 - CONFIG_SYS_INIT_RAM_ADDR:
2559 Start address of memory area that can be used for
2560 initial data and stack; please note that this must be
2561 writable memory that is working WITHOUT special
2562 initialization, i. e. you CANNOT use normal RAM which
2563 will become available only after programming the
2564 memory controller and running certain initialization
2567 U-Boot uses the following memory types:
2568 - MPC8xx and MPC8260: IMMR (internal memory of the CPU)
2569 - MPC824X: data cache
2570 - PPC4xx: data cache
2572 - CONFIG_SYS_GBL_DATA_OFFSET:
2574 Offset of the initial data structure in the memory
2575 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually
2576 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial
2577 data is located at the end of the available space
2578 (sometimes written as (CONFIG_SYS_INIT_RAM_END -
2579 CONFIG_SYS_INIT_DATA_SIZE), and the initial stack is just
2580 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR +
2581 CONFIG_SYS_GBL_DATA_OFFSET) downward.
2584 On the MPC824X (or other systems that use the data
2585 cache for initial memory) the address chosen for
2586 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must
2587 point to an otherwise UNUSED address space between
2588 the top of RAM and the start of the PCI space.
2590 - CONFIG_SYS_SIUMCR: SIU Module Configuration (11-6)
2592 - CONFIG_SYS_SYPCR: System Protection Control (11-9)
2594 - CONFIG_SYS_TBSCR: Time Base Status and Control (11-26)
2596 - CONFIG_SYS_PISCR: Periodic Interrupt Status and Control (11-31)
2598 - CONFIG_SYS_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30)
2600 - CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27)
2602 - CONFIG_SYS_OR_TIMING_SDRAM:
2605 - CONFIG_SYS_MAMR_PTA:
2606 periodic timer for refresh
2608 - CONFIG_SYS_DER: Debug Event Register (37-47)
2610 - FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM,
2611 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP,
2612 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM,
2613 CONFIG_SYS_BR1_PRELIM:
2614 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
2616 - SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
2617 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM,
2618 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM:
2619 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
2621 - CONFIG_SYS_MAMR_PTA, CONFIG_SYS_MPTPR_2BK_4K, CONFIG_SYS_MPTPR_1BK_4K, CONFIG_SYS_MPTPR_2BK_8K,
2622 CONFIG_SYS_MPTPR_1BK_8K, CONFIG_SYS_MAMR_8COL, CONFIG_SYS_MAMR_9COL:
2623 Machine Mode Register and Memory Periodic Timer
2624 Prescaler definitions (SDRAM timing)
2626 - CONFIG_SYS_I2C_UCODE_PATCH, CONFIG_SYS_I2C_DPMEM_OFFSET [0x1FC0]:
2627 enable I2C microcode relocation patch (MPC8xx);
2628 define relocation offset in DPRAM [DSP2]
2630 - CONFIG_SYS_SMC_UCODE_PATCH, CONFIG_SYS_SMC_DPMEM_OFFSET [0x1FC0]:
2631 enable SMC microcode relocation patch (MPC8xx);
2632 define relocation offset in DPRAM [SMC1]
2634 - CONFIG_SYS_SPI_UCODE_PATCH, CONFIG_SYS_SPI_DPMEM_OFFSET [0x1FC0]:
2635 enable SPI microcode relocation patch (MPC8xx);
2636 define relocation offset in DPRAM [SCC4]
2638 - CONFIG_SYS_USE_OSCCLK:
2639 Use OSCM clock mode on MBX8xx board. Be careful,
2640 wrong setting might damage your board. Read
2641 doc/README.MBX before setting this variable!
2643 - CONFIG_SYS_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only)
2644 Offset of the bootmode word in DPRAM used by post
2645 (Power On Self Tests). This definition overrides
2646 #define'd default value in commproc.h resp.
2649 - CONFIG_SYS_PCI_SLV_MEM_LOCAL, CONFIG_SYS_PCI_SLV_MEM_BUS, CONFIG_SYS_PICMR0_MASK_ATTRIB,
2650 CONFIG_SYS_PCI_MSTR0_LOCAL, CONFIG_SYS_PCIMSK0_MASK, CONFIG_SYS_PCI_MSTR1_LOCAL,
2651 CONFIG_SYS_PCIMSK1_MASK, CONFIG_SYS_PCI_MSTR_MEM_LOCAL, CONFIG_SYS_PCI_MSTR_MEM_BUS,
2652 CONFIG_SYS_CPU_PCI_MEM_START, CONFIG_SYS_PCI_MSTR_MEM_SIZE, CONFIG_SYS_POCMR0_MASK_ATTRIB,
2653 CONFIG_SYS_PCI_MSTR_MEMIO_LOCAL, CONFIG_SYS_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START,
2654 CONFIG_SYS_PCI_MSTR_MEMIO_SIZE, CONFIG_SYS_POCMR1_MASK_ATTRIB, CONFIG_SYS_PCI_MSTR_IO_LOCAL,
2655 CONFIG_SYS_PCI_MSTR_IO_BUS, CONFIG_SYS_CPU_PCI_IO_START, CONFIG_SYS_PCI_MSTR_IO_SIZE,
2656 CONFIG_SYS_POCMR2_MASK_ATTRIB: (MPC826x only)
2657 Overrides the default PCI memory map in cpu/mpc8260/pci.c if set.
2659 - CONFIG_PCI_DISABLE_PCIE:
2660 Disable PCI-Express on systems where it is supported but not
2664 Get DDR timing information from an I2C EEPROM. Common
2665 with pluggable memory modules such as SODIMMs
2668 I2C address of the SPD EEPROM
2670 - CONFIG_SYS_SPD_BUS_NUM
2671 If SPD EEPROM is on an I2C bus other than the first
2672 one, specify here. Note that the value must resolve
2673 to something your driver can deal with.
2675 - CONFIG_SYS_83XX_DDR_USES_CS0
2676 Only for 83xx systems. If specified, then DDR should
2677 be configured using CS0 and CS1 instead of CS2 and CS3.
2679 - CONFIG_ETHER_ON_FEC[12]
2680 Define to enable FEC[12] on a 8xx series processor.
2682 - CONFIG_FEC[12]_PHY
2683 Define to the hardcoded PHY address which corresponds
2684 to the given FEC; i. e.
2685 #define CONFIG_FEC1_PHY 4
2686 means that the PHY with address 4 is connected to FEC1
2688 When set to -1, means to probe for first available.
2690 - CONFIG_FEC[12]_PHY_NORXERR
2691 The PHY does not have a RXERR line (RMII only).
2692 (so program the FEC to ignore it).
2695 Enable RMII mode for all FECs.
2696 Note that this is a global option, we can't
2697 have one FEC in standard MII mode and another in RMII mode.
2699 - CONFIG_CRC32_VERIFY
2700 Add a verify option to the crc32 command.
2703 => crc32 -v <address> <count> <crc32>
2705 Where address/count indicate a memory area
2706 and crc32 is the correct crc32 which the
2710 Add the "loopw" memory command. This only takes effect if
2711 the memory commands are activated globally (CONFIG_CMD_MEM).
2714 Add the "mdc" and "mwc" memory commands. These are cyclic
2719 This command will print 4 bytes (10,11,12,13) each 500 ms.
2721 => mwc.l 100 12345678 10
2722 This command will write 12345678 to address 100 all 10 ms.
2724 This only takes effect if the memory commands are activated
2725 globally (CONFIG_CMD_MEM).
2727 - CONFIG_SKIP_LOWLEVEL_INIT
2728 - CONFIG_SKIP_RELOCATE_UBOOT
2730 [ARM only] If these variables are defined, then
2731 certain low level initializations (like setting up
2732 the memory controller) are omitted and/or U-Boot does
2733 not relocate itself into RAM.
2734 Normally these variables MUST NOT be defined. The
2735 only exception is when U-Boot is loaded (to RAM) by
2736 some other boot loader or by a debugger which
2737 performs these initializations itself.
2741 Modifies the behaviour of start.S when compiling a loader
2742 that is executed before the actual U-Boot. E.g. when
2743 compiling a NAND SPL.
2745 Building the Software:
2746 ======================
2748 Building U-Boot has been tested in several native build environments
2749 and in many different cross environments. Of course we cannot support
2750 all possibly existing versions of cross development tools in all
2751 (potentially obsolete) versions. In case of tool chain problems we
2752 recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK)
2753 which is extensively used to build and test U-Boot.
2755 If you are not using a native environment, it is assumed that you
2756 have GNU cross compiling tools available in your path. In this case,
2757 you must set the environment variable CROSS_COMPILE in your shell.
2758 Note that no changes to the Makefile or any other source files are
2759 necessary. For example using the ELDK on a 4xx CPU, please enter:
2761 $ CROSS_COMPILE=ppc_4xx-
2762 $ export CROSS_COMPILE
2764 Note: If you wish to generate Windows versions of the utilities in
2765 the tools directory you can use the MinGW toolchain
2766 (http://www.mingw.org). Set your HOST tools to the MinGW
2767 toolchain and execute 'make tools'. For example:
2769 $ make HOSTCC=i586-mingw32msvc-gcc HOSTSTRIP=i586-mingw32msvc-strip tools
2771 Binaries such as tools/mkimage.exe will be created which can
2772 be executed on computers running Windows.
2774 U-Boot is intended to be simple to build. After installing the
2775 sources you must configure U-Boot for one specific board type. This
2780 where "NAME_config" is the name of one of the existing configu-
2781 rations; see the main Makefile for supported names.
2783 Note: for some board special configuration names may exist; check if
2784 additional information is available from the board vendor; for
2785 instance, the TQM823L systems are available without (standard)
2786 or with LCD support. You can select such additional "features"
2787 when choosing the configuration, i. e.
2790 - will configure for a plain TQM823L, i. e. no LCD support
2792 make TQM823L_LCD_config
2793 - will configure for a TQM823L with U-Boot console on LCD
2798 Finally, type "make all", and you should get some working U-Boot
2799 images ready for download to / installation on your system:
2801 - "u-boot.bin" is a raw binary image
2802 - "u-boot" is an image in ELF binary format
2803 - "u-boot.srec" is in Motorola S-Record format
2805 By default the build is performed locally and the objects are saved
2806 in the source directory. One of the two methods can be used to change
2807 this behavior and build U-Boot to some external directory:
2809 1. Add O= to the make command line invocations:
2811 make O=/tmp/build distclean
2812 make O=/tmp/build NAME_config
2813 make O=/tmp/build all
2815 2. Set environment variable BUILD_DIR to point to the desired location:
2817 export BUILD_DIR=/tmp/build
2822 Note that the command line "O=" setting overrides the BUILD_DIR environment
2826 Please be aware that the Makefiles assume you are using GNU make, so
2827 for instance on NetBSD you might need to use "gmake" instead of
2831 If the system board that you have is not listed, then you will need
2832 to port U-Boot to your hardware platform. To do this, follow these
2835 1. Add a new configuration option for your board to the toplevel
2836 "Makefile" and to the "MAKEALL" script, using the existing
2837 entries as examples. Note that here and at many other places
2838 boards and other names are listed in alphabetical sort order. Please
2840 2. Create a new directory to hold your board specific code. Add any
2841 files you need. In your board directory, you will need at least
2842 the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds".
2843 3. Create a new configuration file "include/configs/<board>.h" for
2845 3. If you're porting U-Boot to a new CPU, then also create a new
2846 directory to hold your CPU specific code. Add any files you need.
2847 4. Run "make <board>_config" with your new name.
2848 5. Type "make", and you should get a working "u-boot.srec" file
2849 to be installed on your target system.
2850 6. Debug and solve any problems that might arise.
2851 [Of course, this last step is much harder than it sounds.]
2854 Testing of U-Boot Modifications, Ports to New Hardware, etc.:
2855 ==============================================================
2857 If you have modified U-Boot sources (for instance added a new board
2858 or support for new devices, a new CPU, etc.) you are expected to
2859 provide feedback to the other developers. The feedback normally takes
2860 the form of a "patch", i. e. a context diff against a certain (latest
2861 official or latest in the git repository) version of U-Boot sources.
2863 But before you submit such a patch, please verify that your modifi-
2864 cation did not break existing code. At least make sure that *ALL* of
2865 the supported boards compile WITHOUT ANY compiler warnings. To do so,
2866 just run the "MAKEALL" script, which will configure and build U-Boot
2867 for ALL supported system. Be warned, this will take a while. You can
2868 select which (cross) compiler to use by passing a `CROSS_COMPILE'
2869 environment variable to the script, i. e. to use the ELDK cross tools
2872 CROSS_COMPILE=ppc_8xx- MAKEALL
2874 or to build on a native PowerPC system you can type
2876 CROSS_COMPILE=' ' MAKEALL
2878 When using the MAKEALL script, the default behaviour is to build
2879 U-Boot in the source directory. This location can be changed by
2880 setting the BUILD_DIR environment variable. Also, for each target
2881 built, the MAKEALL script saves two log files (<target>.ERR and
2882 <target>.MAKEALL) in the <source dir>/LOG directory. This default
2883 location can be changed by setting the MAKEALL_LOGDIR environment
2884 variable. For example:
2886 export BUILD_DIR=/tmp/build
2887 export MAKEALL_LOGDIR=/tmp/log
2888 CROSS_COMPILE=ppc_8xx- MAKEALL
2890 With the above settings build objects are saved in the /tmp/build,
2891 log files are saved in the /tmp/log and the source tree remains clean
2892 during the whole build process.
2895 See also "U-Boot Porting Guide" below.
2898 Monitor Commands - Overview:
2899 ============================
2901 go - start application at address 'addr'
2902 run - run commands in an environment variable
2903 bootm - boot application image from memory
2904 bootp - boot image via network using BootP/TFTP protocol
2905 tftpboot- boot image via network using TFTP protocol
2906 and env variables "ipaddr" and "serverip"
2907 (and eventually "gatewayip")
2908 rarpboot- boot image via network using RARP/TFTP protocol
2909 diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
2910 loads - load S-Record file over serial line
2911 loadb - load binary file over serial line (kermit mode)
2913 mm - memory modify (auto-incrementing)
2914 nm - memory modify (constant address)
2915 mw - memory write (fill)
2917 cmp - memory compare
2918 crc32 - checksum calculation
2919 i2c - I2C sub-system
2920 sspi - SPI utility commands
2921 base - print or set address offset
2922 printenv- print environment variables
2923 setenv - set environment variables
2924 saveenv - save environment variables to persistent storage
2925 protect - enable or disable FLASH write protection
2926 erase - erase FLASH memory
2927 flinfo - print FLASH memory information
2928 bdinfo - print Board Info structure
2929 iminfo - print header information for application image
2930 coninfo - print console devices and informations
2931 ide - IDE sub-system
2932 loop - infinite loop on address range
2933 loopw - infinite write loop on address range
2934 mtest - simple RAM test
2935 icache - enable or disable instruction cache
2936 dcache - enable or disable data cache
2937 reset - Perform RESET of the CPU
2938 echo - echo args to console
2939 version - print monitor version
2940 help - print online help
2941 ? - alias for 'help'
2944 Monitor Commands - Detailed Description:
2945 ========================================
2949 For now: just type "help <command>".
2952 Environment Variables:
2953 ======================
2955 U-Boot supports user configuration using Environment Variables which
2956 can be made persistent by saving to Flash memory.
2958 Environment Variables are set using "setenv", printed using
2959 "printenv", and saved to Flash using "saveenv". Using "setenv"
2960 without a value can be used to delete a variable from the
2961 environment. As long as you don't save the environment you are
2962 working with an in-memory copy. In case the Flash area containing the
2963 environment is erased by accident, a default environment is provided.
2965 Some configuration options can be set using Environment Variables:
2967 baudrate - see CONFIG_BAUDRATE
2969 bootdelay - see CONFIG_BOOTDELAY
2971 bootcmd - see CONFIG_BOOTCOMMAND
2973 bootargs - Boot arguments when booting an RTOS image
2975 bootfile - Name of the image to load with TFTP
2977 bootm_low - Memory range available for image processing in the bootm
2978 command can be restricted. This variable is given as
2979 a hexadecimal number and defines lowest address allowed
2980 for use by the bootm command. See also "bootm_size"
2981 environment variable. Address defined by "bootm_low" is
2982 also the base of the initial memory mapping for the Linux
2983 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ.
2985 bootm_size - Memory range available for image processing in the bootm
2986 command can be restricted. This variable is given as
2987 a hexadecimal number and defines the size of the region
2988 allowed for use by the bootm command. See also "bootm_low"
2989 environment variable.
2991 updatefile - Location of the software update file on a TFTP server, used
2992 by the automatic software update feature. Please refer to
2993 documentation in doc/README.update for more details.
2995 autoload - if set to "no" (any string beginning with 'n'),
2996 "bootp" will just load perform a lookup of the
2997 configuration from the BOOTP server, but not try to
2998 load any image using TFTP
3000 autoscript - if set to "yes" commands like "loadb", "loady",
3001 "bootp", "tftpb", "rarpboot" and "nfs" will attempt
3002 to automatically run script images (by internally
3005 autoscript_uname - if script image is in a format (FIT) this
3006 variable is used to get script subimage unit name.
3008 autostart - if set to "yes", an image loaded using the "bootp",
3009 "rarpboot", "tftpboot" or "diskboot" commands will
3010 be automatically started (by internally calling
3013 If set to "no", a standalone image passed to the
3014 "bootm" command will be copied to the load address
3015 (and eventually uncompressed), but NOT be started.
3016 This can be used to load and uncompress arbitrary
3019 i2cfast - (PPC405GP|PPC405EP only)
3020 if set to 'y' configures Linux I2C driver for fast
3021 mode (400kHZ). This environment variable is used in
3022 initialization code. So, for changes to be effective
3023 it must be saved and board must be reset.
3025 initrd_high - restrict positioning of initrd images:
3026 If this variable is not set, initrd images will be
3027 copied to the highest possible address in RAM; this
3028 is usually what you want since it allows for
3029 maximum initrd size. If for some reason you want to
3030 make sure that the initrd image is loaded below the
3031 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment
3032 variable to a value of "no" or "off" or "0".
3033 Alternatively, you can set it to a maximum upper
3034 address to use (U-Boot will still check that it
3035 does not overwrite the U-Boot stack and data).
3037 For instance, when you have a system with 16 MB
3038 RAM, and want to reserve 4 MB from use by Linux,
3039 you can do this by adding "mem=12M" to the value of
3040 the "bootargs" variable. However, now you must make
3041 sure that the initrd image is placed in the first
3042 12 MB as well - this can be done with
3044 setenv initrd_high 00c00000
3046 If you set initrd_high to 0xFFFFFFFF, this is an
3047 indication to U-Boot that all addresses are legal
3048 for the Linux kernel, including addresses in flash
3049 memory. In this case U-Boot will NOT COPY the
3050 ramdisk at all. This may be useful to reduce the
3051 boot time on your system, but requires that this
3052 feature is supported by your Linux kernel.
3054 ipaddr - IP address; needed for tftpboot command
3056 loadaddr - Default load address for commands like "bootp",
3057 "rarpboot", "tftpboot", "loadb" or "diskboot"
3059 loads_echo - see CONFIG_LOADS_ECHO
3061 serverip - TFTP server IP address; needed for tftpboot command
3063 bootretry - see CONFIG_BOOT_RETRY_TIME
3065 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
3067 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
3069 ethprime - When CONFIG_NET_MULTI is enabled controls which
3070 interface is used first.
3072 ethact - When CONFIG_NET_MULTI is enabled controls which
3073 interface is currently active. For example you
3074 can do the following
3076 => setenv ethact FEC ETHERNET
3077 => ping 192.168.0.1 # traffic sent on FEC ETHERNET
3078 => setenv ethact SCC ETHERNET
3079 => ping 10.0.0.1 # traffic sent on SCC ETHERNET
3081 ethrotate - When set to "no" U-Boot does not go through all
3082 available network interfaces.
3083 It just stays at the currently selected interface.
3085 netretry - When set to "no" each network operation will
3086 either succeed or fail without retrying.
3087 When set to "once" the network operation will
3088 fail when all the available network interfaces
3089 are tried once without success.
3090 Useful on scripts which control the retry operation
3093 npe_ucode - set load address for the NPE microcode
3095 tftpsrcport - If this is set, the value is used for TFTP's
3098 tftpdstport - If this is set, the value is used for TFTP's UDP
3099 destination port instead of the Well Know Port 69.
3101 vlan - When set to a value < 4095 the traffic over
3102 Ethernet is encapsulated/received over 802.1q
3105 The following environment variables may be used and automatically
3106 updated by the network boot commands ("bootp" and "rarpboot"),
3107 depending the information provided by your boot server:
3109 bootfile - see above
3110 dnsip - IP address of your Domain Name Server
3111 dnsip2 - IP address of your secondary Domain Name Server
3112 gatewayip - IP address of the Gateway (Router) to use
3113 hostname - Target hostname
3115 netmask - Subnet Mask
3116 rootpath - Pathname of the root filesystem on the NFS server
3117 serverip - see above
3120 There are two special Environment Variables:
3122 serial# - contains hardware identification information such
3123 as type string and/or serial number
3124 ethaddr - Ethernet address
3126 These variables can be set only once (usually during manufacturing of
3127 the board). U-Boot refuses to delete or overwrite these variables
3128 once they have been set once.
3131 Further special Environment Variables:
3133 ver - Contains the U-Boot version string as printed
3134 with the "version" command. This variable is
3135 readonly (see CONFIG_VERSION_VARIABLE).
3138 Please note that changes to some configuration parameters may take
3139 only effect after the next boot (yes, that's just like Windoze :-).
3142 Command Line Parsing:
3143 =====================
3145 There are two different command line parsers available with U-Boot:
3146 the old "simple" one, and the much more powerful "hush" shell:
3148 Old, simple command line parser:
3149 --------------------------------
3151 - supports environment variables (through setenv / saveenv commands)
3152 - several commands on one line, separated by ';'
3153 - variable substitution using "... ${name} ..." syntax
3154 - special characters ('$', ';') can be escaped by prefixing with '\',
3156 setenv bootcmd bootm \${address}
3157 - You can also escape text by enclosing in single apostrophes, for example:
3158 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
3163 - similar to Bourne shell, with control structures like
3164 if...then...else...fi, for...do...done; while...do...done,
3165 until...do...done, ...
3166 - supports environment ("global") variables (through setenv / saveenv
3167 commands) and local shell variables (through standard shell syntax
3168 "name=value"); only environment variables can be used with "run"
3174 (1) If a command line (or an environment variable executed by a "run"
3175 command) contains several commands separated by semicolon, and
3176 one of these commands fails, then the remaining commands will be
3179 (2) If you execute several variables with one call to run (i. e.
3180 calling run with a list of variables as arguments), any failing
3181 command will cause "run" to terminate, i. e. the remaining
3182 variables are not executed.
3184 Note for Redundant Ethernet Interfaces:
3185 =======================================
3187 Some boards come with redundant Ethernet interfaces; U-Boot supports
3188 such configurations and is capable of automatic selection of a
3189 "working" interface when needed. MAC assignment works as follows:
3191 Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
3192 MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
3193 "eth1addr" (=>eth1), "eth2addr", ...
3195 If the network interface stores some valid MAC address (for instance
3196 in SROM), this is used as default address if there is NO correspon-
3197 ding setting in the environment; if the corresponding environment
3198 variable is set, this overrides the settings in the card; that means:
3200 o If the SROM has a valid MAC address, and there is no address in the
3201 environment, the SROM's address is used.
3203 o If there is no valid address in the SROM, and a definition in the
3204 environment exists, then the value from the environment variable is
3207 o If both the SROM and the environment contain a MAC address, and
3208 both addresses are the same, this MAC address is used.
3210 o If both the SROM and the environment contain a MAC address, and the
3211 addresses differ, the value from the environment is used and a
3214 o If neither SROM nor the environment contain a MAC address, an error
3221 U-Boot is capable of booting (and performing other auxiliary operations on)
3222 images in two formats:
3224 New uImage format (FIT)
3225 -----------------------
3227 Flexible and powerful format based on Flattened Image Tree -- FIT (similar
3228 to Flattened Device Tree). It allows the use of images with multiple
3229 components (several kernels, ramdisks, etc.), with contents protected by
3230 SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory.
3236 Old image format is based on binary files which can be basically anything,
3237 preceded by a special header; see the definitions in include/image.h for
3238 details; basically, the header defines the following image properties:
3240 * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
3241 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
3242 LynxOS, pSOS, QNX, RTEMS, INTEGRITY;
3243 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS,
3245 * Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86,
3246 IA64, MIPS, NIOS, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
3247 Currently supported: ARM, AVR32, Intel x86, MIPS, NIOS, PowerPC).
3248 * Compression Type (uncompressed, gzip, bzip2)
3254 The header is marked by a special Magic Number, and both the header
3255 and the data portions of the image are secured against corruption by
3262 Although U-Boot should support any OS or standalone application
3263 easily, the main focus has always been on Linux during the design of
3266 U-Boot includes many features that so far have been part of some
3267 special "boot loader" code within the Linux kernel. Also, any
3268 "initrd" images to be used are no longer part of one big Linux image;
3269 instead, kernel and "initrd" are separate images. This implementation
3270 serves several purposes:
3272 - the same features can be used for other OS or standalone
3273 applications (for instance: using compressed images to reduce the
3274 Flash memory footprint)
3276 - it becomes much easier to port new Linux kernel versions because
3277 lots of low-level, hardware dependent stuff are done by U-Boot
3279 - the same Linux kernel image can now be used with different "initrd"
3280 images; of course this also means that different kernel images can
3281 be run with the same "initrd". This makes testing easier (you don't
3282 have to build a new "zImage.initrd" Linux image when you just
3283 change a file in your "initrd"). Also, a field-upgrade of the
3284 software is easier now.
3290 Porting Linux to U-Boot based systems:
3291 ---------------------------------------
3293 U-Boot cannot save you from doing all the necessary modifications to
3294 configure the Linux device drivers for use with your target hardware
3295 (no, we don't intend to provide a full virtual machine interface to
3298 But now you can ignore ALL boot loader code (in arch/ppc/mbxboot).
3300 Just make sure your machine specific header file (for instance
3301 include/asm-ppc/tqm8xx.h) includes the same definition of the Board
3302 Information structure as we define in include/asm-<arch>/u-boot.h,
3303 and make sure that your definition of IMAP_ADDR uses the same value
3304 as your U-Boot configuration in CONFIG_SYS_IMMR.
3307 Configuring the Linux kernel:
3308 -----------------------------
3310 No specific requirements for U-Boot. Make sure you have some root
3311 device (initial ramdisk, NFS) for your target system.
3314 Building a Linux Image:
3315 -----------------------
3317 With U-Boot, "normal" build targets like "zImage" or "bzImage" are
3318 not used. If you use recent kernel source, a new build target
3319 "uImage" will exist which automatically builds an image usable by
3320 U-Boot. Most older kernels also have support for a "pImage" target,
3321 which was introduced for our predecessor project PPCBoot and uses a
3322 100% compatible format.
3331 The "uImage" build target uses a special tool (in 'tools/mkimage') to
3332 encapsulate a compressed Linux kernel image with header information,
3333 CRC32 checksum etc. for use with U-Boot. This is what we are doing:
3335 * build a standard "vmlinux" kernel image (in ELF binary format):
3337 * convert the kernel into a raw binary image:
3339 ${CROSS_COMPILE}-objcopy -O binary \
3340 -R .note -R .comment \
3341 -S vmlinux linux.bin
3343 * compress the binary image:
3347 * package compressed binary image for U-Boot:
3349 mkimage -A ppc -O linux -T kernel -C gzip \
3350 -a 0 -e 0 -n "Linux Kernel Image" \
3351 -d linux.bin.gz uImage
3354 The "mkimage" tool can also be used to create ramdisk images for use
3355 with U-Boot, either separated from the Linux kernel image, or
3356 combined into one file. "mkimage" encapsulates the images with a 64
3357 byte header containing information about target architecture,
3358 operating system, image type, compression method, entry points, time
3359 stamp, CRC32 checksums, etc.
3361 "mkimage" can be called in two ways: to verify existing images and
3362 print the header information, or to build new images.
3364 In the first form (with "-l" option) mkimage lists the information
3365 contained in the header of an existing U-Boot image; this includes
3366 checksum verification:
3368 tools/mkimage -l image
3369 -l ==> list image header information
3371 The second form (with "-d" option) is used to build a U-Boot image
3372 from a "data file" which is used as image payload:
3374 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
3375 -n name -d data_file image
3376 -A ==> set architecture to 'arch'
3377 -O ==> set operating system to 'os'
3378 -T ==> set image type to 'type'
3379 -C ==> set compression type 'comp'
3380 -a ==> set load address to 'addr' (hex)
3381 -e ==> set entry point to 'ep' (hex)
3382 -n ==> set image name to 'name'
3383 -d ==> use image data from 'datafile'
3385 Right now, all Linux kernels for PowerPC systems use the same load
3386 address (0x00000000), but the entry point address depends on the
3389 - 2.2.x kernels have the entry point at 0x0000000C,
3390 - 2.3.x and later kernels have the entry point at 0x00000000.
3392 So a typical call to build a U-Boot image would read:
3394 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
3395 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
3396 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux.gz \
3397 > examples/uImage.TQM850L
3398 Image Name: 2.4.4 kernel for TQM850L
3399 Created: Wed Jul 19 02:34:59 2000
3400 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3401 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
3402 Load Address: 0x00000000
3403 Entry Point: 0x00000000
3405 To verify the contents of the image (or check for corruption):
3407 -> tools/mkimage -l examples/uImage.TQM850L
3408 Image Name: 2.4.4 kernel for TQM850L
3409 Created: Wed Jul 19 02:34:59 2000
3410 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3411 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
3412 Load Address: 0x00000000
3413 Entry Point: 0x00000000
3415 NOTE: for embedded systems where boot time is critical you can trade
3416 speed for memory and install an UNCOMPRESSED image instead: this
3417 needs more space in Flash, but boots much faster since it does not
3418 need to be uncompressed:
3420 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux.gz
3421 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
3422 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
3423 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux \
3424 > examples/uImage.TQM850L-uncompressed
3425 Image Name: 2.4.4 kernel for TQM850L
3426 Created: Wed Jul 19 02:34:59 2000
3427 Image Type: PowerPC Linux Kernel Image (uncompressed)
3428 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
3429 Load Address: 0x00000000
3430 Entry Point: 0x00000000
3433 Similar you can build U-Boot images from a 'ramdisk.image.gz' file
3434 when your kernel is intended to use an initial ramdisk:
3436 -> tools/mkimage -n 'Simple Ramdisk Image' \
3437 > -A ppc -O linux -T ramdisk -C gzip \
3438 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
3439 Image Name: Simple Ramdisk Image
3440 Created: Wed Jan 12 14:01:50 2000
3441 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
3442 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
3443 Load Address: 0x00000000
3444 Entry Point: 0x00000000
3447 Installing a Linux Image:
3448 -------------------------
3450 To downloading a U-Boot image over the serial (console) interface,
3451 you must convert the image to S-Record format:
3453 objcopy -I binary -O srec examples/image examples/image.srec
3455 The 'objcopy' does not understand the information in the U-Boot
3456 image header, so the resulting S-Record file will be relative to
3457 address 0x00000000. To load it to a given address, you need to
3458 specify the target address as 'offset' parameter with the 'loads'
3461 Example: install the image to address 0x40100000 (which on the
3462 TQM8xxL is in the first Flash bank):
3464 => erase 40100000 401FFFFF
3470 ## Ready for S-Record download ...
3471 ~>examples/image.srec
3472 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
3474 15989 15990 15991 15992
3475 [file transfer complete]
3477 ## Start Addr = 0x00000000
3480 You can check the success of the download using the 'iminfo' command;
3481 this includes a checksum verification so you can be sure no data
3482 corruption happened:
3486 ## Checking Image at 40100000 ...
3487 Image Name: 2.2.13 for initrd on TQM850L
3488 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3489 Data Size: 335725 Bytes = 327 kB = 0 MB
3490 Load Address: 00000000
3491 Entry Point: 0000000c
3492 Verifying Checksum ... OK
3498 The "bootm" command is used to boot an application that is stored in
3499 memory (RAM or Flash). In case of a Linux kernel image, the contents
3500 of the "bootargs" environment variable is passed to the kernel as
3501 parameters. You can check and modify this variable using the
3502 "printenv" and "setenv" commands:
3505 => printenv bootargs
3506 bootargs=root=/dev/ram
3508 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
3510 => printenv bootargs
3511 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
3514 ## Booting Linux kernel at 40020000 ...
3515 Image Name: 2.2.13 for NFS on TQM850L
3516 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3517 Data Size: 381681 Bytes = 372 kB = 0 MB
3518 Load Address: 00000000
3519 Entry Point: 0000000c
3520 Verifying Checksum ... OK
3521 Uncompressing Kernel Image ... OK
3522 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
3523 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
3524 time_init: decrementer frequency = 187500000/60
3525 Calibrating delay loop... 49.77 BogoMIPS
3526 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
3529 If you want to boot a Linux kernel with initial RAM disk, you pass
3530 the memory addresses of both the kernel and the initrd image (PPBCOOT
3531 format!) to the "bootm" command:
3533 => imi 40100000 40200000
3535 ## Checking Image at 40100000 ...
3536 Image Name: 2.2.13 for initrd on TQM850L
3537 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3538 Data Size: 335725 Bytes = 327 kB = 0 MB
3539 Load Address: 00000000
3540 Entry Point: 0000000c
3541 Verifying Checksum ... OK
3543 ## Checking Image at 40200000 ...
3544 Image Name: Simple Ramdisk Image
3545 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
3546 Data Size: 566530 Bytes = 553 kB = 0 MB
3547 Load Address: 00000000
3548 Entry Point: 00000000
3549 Verifying Checksum ... OK
3551 => bootm 40100000 40200000
3552 ## Booting Linux kernel at 40100000 ...
3553 Image Name: 2.2.13 for initrd on TQM850L
3554 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3555 Data Size: 335725 Bytes = 327 kB = 0 MB
3556 Load Address: 00000000
3557 Entry Point: 0000000c
3558 Verifying Checksum ... OK
3559 Uncompressing Kernel Image ... OK
3560 ## Loading RAMDisk Image at 40200000 ...
3561 Image Name: Simple Ramdisk Image
3562 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
3563 Data Size: 566530 Bytes = 553 kB = 0 MB
3564 Load Address: 00000000
3565 Entry Point: 00000000
3566 Verifying Checksum ... OK
3567 Loading Ramdisk ... OK
3568 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
3569 Boot arguments: root=/dev/ram
3570 time_init: decrementer frequency = 187500000/60
3571 Calibrating delay loop... 49.77 BogoMIPS
3573 RAMDISK: Compressed image found at block 0
3574 VFS: Mounted root (ext2 filesystem).
3578 Boot Linux and pass a flat device tree:
3581 First, U-Boot must be compiled with the appropriate defines. See the section
3582 titled "Linux Kernel Interface" above for a more in depth explanation. The
3583 following is an example of how to start a kernel and pass an updated
3589 oft=oftrees/mpc8540ads.dtb
3590 => tftp $oftaddr $oft
3591 Speed: 1000, full duplex
3593 TFTP from server 192.168.1.1; our IP address is 192.168.1.101
3594 Filename 'oftrees/mpc8540ads.dtb'.
3595 Load address: 0x300000
3598 Bytes transferred = 4106 (100a hex)
3599 => tftp $loadaddr $bootfile
3600 Speed: 1000, full duplex
3602 TFTP from server 192.168.1.1; our IP address is 192.168.1.2
3604 Load address: 0x200000
3605 Loading:############
3607 Bytes transferred = 1029407 (fb51f hex)
3612 => bootm $loadaddr - $oftaddr
3613 ## Booting image at 00200000 ...
3614 Image Name: Linux-2.6.17-dirty
3615 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3616 Data Size: 1029343 Bytes = 1005.2 kB
3617 Load Address: 00000000
3618 Entry Point: 00000000
3619 Verifying Checksum ... OK
3620 Uncompressing Kernel Image ... OK
3621 Booting using flat device tree at 0x300000
3622 Using MPC85xx ADS machine description
3623 Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb
3627 More About U-Boot Image Types:
3628 ------------------------------
3630 U-Boot supports the following image types:
3632 "Standalone Programs" are directly runnable in the environment
3633 provided by U-Boot; it is expected that (if they behave
3634 well) you can continue to work in U-Boot after return from
3635 the Standalone Program.
3636 "OS Kernel Images" are usually images of some Embedded OS which
3637 will take over control completely. Usually these programs
3638 will install their own set of exception handlers, device
3639 drivers, set up the MMU, etc. - this means, that you cannot
3640 expect to re-enter U-Boot except by resetting the CPU.
3641 "RAMDisk Images" are more or less just data blocks, and their
3642 parameters (address, size) are passed to an OS kernel that is
3644 "Multi-File Images" contain several images, typically an OS
3645 (Linux) kernel image and one or more data images like
3646 RAMDisks. This construct is useful for instance when you want
3647 to boot over the network using BOOTP etc., where the boot
3648 server provides just a single image file, but you want to get
3649 for instance an OS kernel and a RAMDisk image.
3651 "Multi-File Images" start with a list of image sizes, each
3652 image size (in bytes) specified by an "uint32_t" in network
3653 byte order. This list is terminated by an "(uint32_t)0".
3654 Immediately after the terminating 0 follow the images, one by
3655 one, all aligned on "uint32_t" boundaries (size rounded up to
3656 a multiple of 4 bytes).
3658 "Firmware Images" are binary images containing firmware (like
3659 U-Boot or FPGA images) which usually will be programmed to
3662 "Script files" are command sequences that will be executed by
3663 U-Boot's command interpreter; this feature is especially
3664 useful when you configure U-Boot to use a real shell (hush)
3665 as command interpreter.
3671 One of the features of U-Boot is that you can dynamically load and
3672 run "standalone" applications, which can use some resources of
3673 U-Boot like console I/O functions or interrupt services.
3675 Two simple examples are included with the sources:
3680 'examples/hello_world.c' contains a small "Hello World" Demo
3681 application; it is automatically compiled when you build U-Boot.
3682 It's configured to run at address 0x00040004, so you can play with it
3686 ## Ready for S-Record download ...
3687 ~>examples/hello_world.srec
3688 1 2 3 4 5 6 7 8 9 10 11 ...
3689 [file transfer complete]
3691 ## Start Addr = 0x00040004
3693 => go 40004 Hello World! This is a test.
3694 ## Starting application at 0x00040004 ...
3705 Hit any key to exit ...
3707 ## Application terminated, rc = 0x0
3709 Another example, which demonstrates how to register a CPM interrupt
3710 handler with the U-Boot code, can be found in 'examples/timer.c'.
3711 Here, a CPM timer is set up to generate an interrupt every second.
3712 The interrupt service routine is trivial, just printing a '.'
3713 character, but this is just a demo program. The application can be
3714 controlled by the following keys:
3716 ? - print current values og the CPM Timer registers
3717 b - enable interrupts and start timer
3718 e - stop timer and disable interrupts
3719 q - quit application
3722 ## Ready for S-Record download ...
3723 ~>examples/timer.srec
3724 1 2 3 4 5 6 7 8 9 10 11 ...
3725 [file transfer complete]
3727 ## Start Addr = 0x00040004
3730 ## Starting application at 0x00040004 ...
3733 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
3736 [q, b, e, ?] Set interval 1000000 us
3739 [q, b, e, ?] ........
3740 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
3743 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
3746 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
3749 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
3751 [q, b, e, ?] ...Stopping timer
3753 [q, b, e, ?] ## Application terminated, rc = 0x0
3759 Over time, many people have reported problems when trying to use the
3760 "minicom" terminal emulation program for serial download. I (wd)
3761 consider minicom to be broken, and recommend not to use it. Under
3762 Unix, I recommend to use C-Kermit for general purpose use (and
3763 especially for kermit binary protocol download ("loadb" command), and
3764 use "cu" for S-Record download ("loads" command).
3766 Nevertheless, if you absolutely want to use it try adding this
3767 configuration to your "File transfer protocols" section:
3769 Name Program Name U/D FullScr IO-Red. Multi
3770 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
3771 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
3777 Starting at version 0.9.2, U-Boot supports NetBSD both as host
3778 (build U-Boot) and target system (boots NetBSD/mpc8xx).
3780 Building requires a cross environment; it is known to work on
3781 NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
3782 need gmake since the Makefiles are not compatible with BSD make).
3783 Note that the cross-powerpc package does not install include files;
3784 attempting to build U-Boot will fail because <machine/ansi.h> is
3785 missing. This file has to be installed and patched manually:
3787 # cd /usr/pkg/cross/powerpc-netbsd/include
3789 # ln -s powerpc machine
3790 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
3791 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
3793 Native builds *don't* work due to incompatibilities between native
3794 and U-Boot include files.
3796 Booting assumes that (the first part of) the image booted is a
3797 stage-2 loader which in turn loads and then invokes the kernel
3798 proper. Loader sources will eventually appear in the NetBSD source
3799 tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
3800 meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz
3803 Implementation Internals:
3804 =========================
3806 The following is not intended to be a complete description of every
3807 implementation detail. However, it should help to understand the
3808 inner workings of U-Boot and make it easier to port it to custom
3812 Initial Stack, Global Data:
3813 ---------------------------
3815 The implementation of U-Boot is complicated by the fact that U-Boot
3816 starts running out of ROM (flash memory), usually without access to
3817 system RAM (because the memory controller is not initialized yet).
3818 This means that we don't have writable Data or BSS segments, and BSS
3819 is not initialized as zero. To be able to get a C environment working
3820 at all, we have to allocate at least a minimal stack. Implementation
3821 options for this are defined and restricted by the CPU used: Some CPU
3822 models provide on-chip memory (like the IMMR area on MPC8xx and
3823 MPC826x processors), on others (parts of) the data cache can be
3824 locked as (mis-) used as memory, etc.
3826 Chris Hallinan posted a good summary of these issues to the
3827 U-Boot mailing list:
3829 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
3830 From: "Chris Hallinan" <clh@net1plus.com>
3831 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
3834 Correct me if I'm wrong, folks, but the way I understand it
3835 is this: Using DCACHE as initial RAM for Stack, etc, does not
3836 require any physical RAM backing up the cache. The cleverness
3837 is that the cache is being used as a temporary supply of
3838 necessary storage before the SDRAM controller is setup. It's
3839 beyond the scope of this list to explain the details, but you
3840 can see how this works by studying the cache architecture and
3841 operation in the architecture and processor-specific manuals.
3843 OCM is On Chip Memory, which I believe the 405GP has 4K. It
3844 is another option for the system designer to use as an
3845 initial stack/RAM area prior to SDRAM being available. Either
3846 option should work for you. Using CS 4 should be fine if your
3847 board designers haven't used it for something that would
3848 cause you grief during the initial boot! It is frequently not
3851 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere
3852 with your processor/board/system design. The default value
3853 you will find in any recent u-boot distribution in
3854 walnut.h should work for you. I'd set it to a value larger
3855 than your SDRAM module. If you have a 64MB SDRAM module, set
3856 it above 400_0000. Just make sure your board has no resources
3857 that are supposed to respond to that address! That code in
3858 start.S has been around a while and should work as is when
3859 you get the config right.
3864 It is essential to remember this, since it has some impact on the C
3865 code for the initialization procedures:
3867 * Initialized global data (data segment) is read-only. Do not attempt
3870 * Do not use any uninitialized global data (or implicitely initialized
3871 as zero data - BSS segment) at all - this is undefined, initiali-
3872 zation is performed later (when relocating to RAM).
3874 * Stack space is very limited. Avoid big data buffers or things like
3877 Having only the stack as writable memory limits means we cannot use
3878 normal global data to share information beween the code. But it
3879 turned out that the implementation of U-Boot can be greatly
3880 simplified by making a global data structure (gd_t) available to all
3881 functions. We could pass a pointer to this data as argument to _all_
3882 functions, but this would bloat the code. Instead we use a feature of
3883 the GCC compiler (Global Register Variables) to share the data: we
3884 place a pointer (gd) to the global data into a register which we
3885 reserve for this purpose.
3887 When choosing a register for such a purpose we are restricted by the
3888 relevant (E)ABI specifications for the current architecture, and by
3889 GCC's implementation.
3891 For PowerPC, the following registers have specific use:
3893 R2: reserved for system use
3894 R3-R4: parameter passing and return values
3895 R5-R10: parameter passing
3896 R13: small data area pointer
3900 (U-Boot also uses R14 as internal GOT pointer.)
3902 ==> U-Boot will use R2 to hold a pointer to the global data
3904 Note: on PPC, we could use a static initializer (since the
3905 address of the global data structure is known at compile time),
3906 but it turned out that reserving a register results in somewhat
3907 smaller code - although the code savings are not that big (on
3908 average for all boards 752 bytes for the whole U-Boot image,
3909 624 text + 127 data).
3911 On Blackfin, the normal C ABI (except for P5) is followed as documented here:
3912 http://docs.blackfin.uclinux.org/doku.php?id=application_binary_interface
3914 ==> U-Boot will use P5 to hold a pointer to the global data
3916 On ARM, the following registers are used:
3918 R0: function argument word/integer result
3919 R1-R3: function argument word
3921 R10: stack limit (used only if stack checking if enabled)
3922 R11: argument (frame) pointer
3923 R12: temporary workspace
3926 R15: program counter
3928 ==> U-Boot will use R8 to hold a pointer to the global data
3930 NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope,
3931 or current versions of GCC may "optimize" the code too much.
3936 U-Boot runs in system state and uses physical addresses, i.e. the
3937 MMU is not used either for address mapping nor for memory protection.
3939 The available memory is mapped to fixed addresses using the memory
3940 controller. In this process, a contiguous block is formed for each
3941 memory type (Flash, SDRAM, SRAM), even when it consists of several
3942 physical memory banks.
3944 U-Boot is installed in the first 128 kB of the first Flash bank (on
3945 TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
3946 booting and sizing and initializing DRAM, the code relocates itself
3947 to the upper end of DRAM. Immediately below the U-Boot code some
3948 memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN
3949 configuration setting]. Below that, a structure with global Board
3950 Info data is placed, followed by the stack (growing downward).
3952 Additionally, some exception handler code is copied to the low 8 kB
3953 of DRAM (0x00000000 ... 0x00001FFF).
3955 So a typical memory configuration with 16 MB of DRAM could look like
3958 0x0000 0000 Exception Vector code
3961 0x0000 2000 Free for Application Use
3967 0x00FB FF20 Monitor Stack (Growing downward)
3968 0x00FB FFAC Board Info Data and permanent copy of global data
3969 0x00FC 0000 Malloc Arena
3972 0x00FE 0000 RAM Copy of Monitor Code
3973 ... eventually: LCD or video framebuffer
3974 ... eventually: pRAM (Protected RAM - unchanged by reset)
3975 0x00FF FFFF [End of RAM]
3978 System Initialization:
3979 ----------------------
3981 In the reset configuration, U-Boot starts at the reset entry point
3982 (on most PowerPC systems at address 0x00000100). Because of the reset
3983 configuration for CS0# this is a mirror of the onboard Flash memory.
3984 To be able to re-map memory U-Boot then jumps to its link address.
3985 To be able to implement the initialization code in C, a (small!)
3986 initial stack is set up in the internal Dual Ported RAM (in case CPUs
3987 which provide such a feature like MPC8xx or MPC8260), or in a locked
3988 part of the data cache. After that, U-Boot initializes the CPU core,
3989 the caches and the SIU.
3991 Next, all (potentially) available memory banks are mapped using a
3992 preliminary mapping. For example, we put them on 512 MB boundaries
3993 (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
3994 on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
3995 programmed for SDRAM access. Using the temporary configuration, a
3996 simple memory test is run that determines the size of the SDRAM
3999 When there is more than one SDRAM bank, and the banks are of
4000 different size, the largest is mapped first. For equal size, the first
4001 bank (CS2#) is mapped first. The first mapping is always for address
4002 0x00000000, with any additional banks following immediately to create
4003 contiguous memory starting from 0.
4005 Then, the monitor installs itself at the upper end of the SDRAM area
4006 and allocates memory for use by malloc() and for the global Board
4007 Info data; also, the exception vector code is copied to the low RAM
4008 pages, and the final stack is set up.
4010 Only after this relocation will you have a "normal" C environment;
4011 until that you are restricted in several ways, mostly because you are
4012 running from ROM, and because the code will have to be relocated to a
4016 U-Boot Porting Guide:
4017 ----------------------
4019 [Based on messages by Jerry Van Baren in the U-Boot-Users mailing
4023 int main(int argc, char *argv[])
4025 sighandler_t no_more_time;
4027 signal(SIGALRM, no_more_time);
4028 alarm(PROJECT_DEADLINE - toSec (3 * WEEK));
4030 if (available_money > available_manpower) {
4031 Pay consultant to port U-Boot;
4035 Download latest U-Boot source;
4037 Subscribe to u-boot mailing list;
4040 email("Hi, I am new to U-Boot, how do I get started?");
4043 Read the README file in the top level directory;
4044 Read http://www.denx.de/twiki/bin/view/DULG/Manual;
4045 Read applicable doc/*.README;
4046 Read the source, Luke;
4047 /* find . -name "*.[chS]" | xargs grep -i <keyword> */
4050 if (available_money > toLocalCurrency ($2500))
4053 Add a lot of aggravation and time;
4055 if (a similar board exists) { /* hopefully... */
4056 cp -a board/<similar> board/<myboard>
4057 cp include/configs/<similar>.h include/configs/<myboard>.h
4059 Create your own board support subdirectory;
4060 Create your own board include/configs/<myboard>.h file;
4062 Edit new board/<myboard> files
4063 Edit new include/configs/<myboard>.h
4068 Add / modify source code;
4072 email("Hi, I am having problems...");
4074 Send patch file to the U-Boot email list;
4075 if (reasonable critiques)
4076 Incorporate improvements from email list code review;
4078 Defend code as written;
4084 void no_more_time (int sig)
4093 All contributions to U-Boot should conform to the Linux kernel
4094 coding style; see the file "Documentation/CodingStyle" and the script
4095 "scripts/Lindent" in your Linux kernel source directory. In sources
4096 originating from U-Boot a style corresponding to "Lindent -pcs" (adding
4097 spaces before parameters to function calls) is actually used.
4099 Source files originating from a different project (for example the
4100 MTD subsystem) are generally exempt from these guidelines and are not
4101 reformated to ease subsequent migration to newer versions of those
4104 Please note that U-Boot is implemented in C (and to some small parts in
4105 Assembler); no C++ is used, so please do not use C++ style comments (//)
4108 Please also stick to the following formatting rules:
4109 - remove any trailing white space
4110 - use TAB characters for indentation, not spaces
4111 - make sure NOT to use DOS '\r\n' line feeds
4112 - do not add more than 2 empty lines to source files
4113 - do not add trailing empty lines to source files
4115 Submissions which do not conform to the standards may be returned
4116 with a request to reformat the changes.
4122 Since the number of patches for U-Boot is growing, we need to
4123 establish some rules. Submissions which do not conform to these rules
4124 may be rejected, even when they contain important and valuable stuff.
4126 Please see http://www.denx.de/wiki/U-Boot/Patches for details.
4128 Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>;
4129 see http://lists.denx.de/mailman/listinfo/u-boot
4131 When you send a patch, please include the following information with
4134 * For bug fixes: a description of the bug and how your patch fixes
4135 this bug. Please try to include a way of demonstrating that the
4136 patch actually fixes something.
4138 * For new features: a description of the feature and your
4141 * A CHANGELOG entry as plaintext (separate from the patch)
4143 * For major contributions, your entry to the CREDITS file
4145 * When you add support for a new board, don't forget to add this
4146 board to the MAKEALL script, too.
4148 * If your patch adds new configuration options, don't forget to
4149 document these in the README file.
4151 * The patch itself. If you are using git (which is *strongly*
4152 recommended) you can easily generate the patch using the
4153 "git-format-patch". If you then use "git-send-email" to send it to
4154 the U-Boot mailing list, you will avoid most of the common problems
4155 with some other mail clients.
4157 If you cannot use git, use "diff -purN OLD NEW". If your version of
4158 diff does not support these options, then get the latest version of
4161 The current directory when running this command shall be the parent
4162 directory of the U-Boot source tree (i. e. please make sure that
4163 your patch includes sufficient directory information for the
4166 We prefer patches as plain text. MIME attachments are discouraged,
4167 and compressed attachments must not be used.
4169 * If one logical set of modifications affects or creates several
4170 files, all these changes shall be submitted in a SINGLE patch file.
4172 * Changesets that contain different, unrelated modifications shall be
4173 submitted as SEPARATE patches, one patch per changeset.
4178 * Before sending the patch, run the MAKEALL script on your patched
4179 source tree and make sure that no errors or warnings are reported
4180 for any of the boards.
4182 * Keep your modifications to the necessary minimum: A patch
4183 containing several unrelated changes or arbitrary reformats will be
4184 returned with a request to re-formatting / split it.
4186 * If you modify existing code, make sure that your new code does not
4187 add to the memory footprint of the code ;-) Small is beautiful!
4188 When adding new features, these should compile conditionally only
4189 (using #ifdef), and the resulting code with the new feature
4190 disabled must not need more memory than the old code without your
4193 * Remember that there is a size limit of 100 kB per message on the
4194 u-boot mailing list. Bigger patches will be moderated. If they are
4195 reasonable and not too big, they will be acknowledged. But patches
4196 bigger than the size limit should be avoided.
projects / u-boot / blob