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_MEMORY md, mm, nm, mw, cp, cmp, crc, base,
634 CONFIG_CMD_MISC Misc functions like sleep etc
635 CONFIG_CMD_MMC * MMC memory mapped support
636 CONFIG_CMD_MII * MII utility commands
637 CONFIG_CMD_MTDPARTS * MTD partition support
638 CONFIG_CMD_NAND * NAND support
639 CONFIG_CMD_NET bootp, tftpboot, rarpboot
640 CONFIG_CMD_PCA953X * PCA953x I2C gpio commands
641 CONFIG_CMD_PCA953X_INFO * PCA953x I2C gpio info command
642 CONFIG_CMD_PCI * pciinfo
643 CONFIG_CMD_PCMCIA * PCMCIA support
644 CONFIG_CMD_PING * send ICMP ECHO_REQUEST to network
646 CONFIG_CMD_PORTIO * Port I/O
647 CONFIG_CMD_REGINFO * Register dump
648 CONFIG_CMD_RUN run command in env variable
649 CONFIG_CMD_SAVES * save S record dump
650 CONFIG_CMD_SCSI * SCSI Support
651 CONFIG_CMD_SDRAM * print SDRAM configuration information
652 (requires CONFIG_CMD_I2C)
653 CONFIG_CMD_SETGETDCR Support for DCR Register access
655 CONFIG_CMD_SOURCE "source" command Support
656 CONFIG_CMD_SPI * SPI serial bus support
657 CONFIG_CMD_USB * USB support
658 CONFIG_CMD_VFD * VFD support (TRAB)
659 CONFIG_CMD_CDP * Cisco Discover Protocol support
660 CONFIG_CMD_FSL * Microblaze FSL support
663 EXAMPLE: If you want all functions except of network
664 support you can write:
666 #include "config_cmd_all.h"
667 #undef CONFIG_CMD_NET
670 fdt (flattened device tree) command: CONFIG_OF_LIBFDT
672 Note: Don't enable the "icache" and "dcache" commands
673 (configuration option CONFIG_CMD_CACHE) unless you know
674 what you (and your U-Boot users) are doing. Data
675 cache cannot be enabled on systems like the 8xx or
676 8260 (where accesses to the IMMR region must be
677 uncached), and it cannot be disabled on all other
678 systems where we (mis-) use the data cache to hold an
679 initial stack and some data.
682 XXX - this list needs to get updated!
686 If this variable is defined, it enables watchdog
687 support. There must be support in the platform specific
688 code for a watchdog. For the 8xx and 8260 CPUs, the
689 SIU Watchdog feature is enabled in the SYPCR
693 CONFIG_VERSION_VARIABLE
694 If this variable is defined, an environment variable
695 named "ver" is created by U-Boot showing the U-Boot
696 version as printed by the "version" command.
697 This variable is readonly.
701 When CONFIG_CMD_DATE is selected, the type of the RTC
702 has to be selected, too. Define exactly one of the
705 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx
706 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC
707 CONFIG_RTC_MC13783 - use MC13783 RTC
708 CONFIG_RTC_MC146818 - use MC146818 RTC
709 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC
710 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC
711 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC
712 CONFIG_RTC_DS164x - use Dallas DS164x RTC
713 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC
714 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC
715 CONFIG_SYS_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337
717 Note that if the RTC uses I2C, then the I2C interface
718 must also be configured. See I2C Support, below.
721 CONFIG_PCA953X - use NXP's PCA953X series I2C GPIO
722 CONFIG_PCA953X_INFO - enable pca953x info command
724 Note that if the GPIO device uses I2C, then the I2C interface
725 must also be configured. See I2C Support, below.
729 When CONFIG_TIMESTAMP is selected, the timestamp
730 (date and time) of an image is printed by image
731 commands like bootm or iminfo. This option is
732 automatically enabled when you select CONFIG_CMD_DATE .
735 CONFIG_MAC_PARTITION and/or CONFIG_DOS_PARTITION
736 and/or CONFIG_ISO_PARTITION and/or CONFIG_EFI_PARTITION
738 If IDE or SCSI support is enabled (CONFIG_CMD_IDE or
739 CONFIG_CMD_SCSI) you must configure support for at
740 least one partition type as well.
743 CONFIG_IDE_RESET_ROUTINE - this is defined in several
744 board configurations files but used nowhere!
746 CONFIG_IDE_RESET - is this is defined, IDE Reset will
747 be performed by calling the function
748 ide_set_reset(int reset)
749 which has to be defined in a board specific file
754 Set this to enable ATAPI support.
759 Set this to enable support for disks larger than 137GB
760 Also look at CONFIG_SYS_64BIT_LBA ,CONFIG_SYS_64BIT_VSPRINTF and CONFIG_SYS_64BIT_STRTOUL
761 Whithout these , LBA48 support uses 32bit variables and will 'only'
762 support disks up to 2.1TB.
764 CONFIG_SYS_64BIT_LBA:
765 When enabled, makes the IDE subsystem use 64bit sector addresses.
769 At the moment only there is only support for the
770 SYM53C8XX SCSI controller; define
771 CONFIG_SCSI_SYM53C8XX to enable it.
773 CONFIG_SYS_SCSI_MAX_LUN [8], CONFIG_SYS_SCSI_MAX_SCSI_ID [7] and
774 CONFIG_SYS_SCSI_MAX_DEVICE [CONFIG_SYS_SCSI_MAX_SCSI_ID *
775 CONFIG_SYS_SCSI_MAX_LUN] can be adjusted to define the
776 maximum numbers of LUNs, SCSI ID's and target
778 CONFIG_SYS_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz)
780 - NETWORK Support (PCI):
782 Support for Intel 8254x gigabit chips.
784 CONFIG_E1000_FALLBACK_MAC
785 default MAC for empty EEPROM after production.
788 Support for Intel 82557/82559/82559ER chips.
789 Optional CONFIG_EEPRO100_SROM_WRITE enables EEPROM
790 write routine for first time initialisation.
793 Support for Digital 2114x chips.
794 Optional CONFIG_TULIP_SELECT_MEDIA for board specific
795 modem chip initialisation (KS8761/QS6611).
798 Support for National dp83815 chips.
801 Support for National dp8382[01] gigabit chips.
803 - NETWORK Support (other):
805 CONFIG_DRIVER_LAN91C96
806 Support for SMSC's LAN91C96 chips.
809 Define this to hold the physical address
810 of the LAN91C96's I/O space
812 CONFIG_LAN91C96_USE_32_BIT
813 Define this to enable 32 bit addressing
815 CONFIG_DRIVER_SMC91111
816 Support for SMSC's LAN91C111 chip
819 Define this to hold the physical address
820 of the device (I/O space)
822 CONFIG_SMC_USE_32_BIT
823 Define this if data bus is 32 bits
825 CONFIG_SMC_USE_IOFUNCS
826 Define this to use i/o functions instead of macros
827 (some hardware wont work with macros)
829 CONFIG_DRIVER_SMC911X
830 Support for SMSC's LAN911x and LAN921x chips
832 CONFIG_DRIVER_SMC911X_BASE
833 Define this to hold the physical address
834 of the device (I/O space)
836 CONFIG_DRIVER_SMC911X_32_BIT
837 Define this if data bus is 32 bits
839 CONFIG_DRIVER_SMC911X_16_BIT
840 Define this if data bus is 16 bits. If your processor
841 automatically converts one 32 bit word to two 16 bit
842 words you may also try CONFIG_DRIVER_SMC911X_32_BIT.
845 At the moment only the UHCI host controller is
846 supported (PIP405, MIP405, MPC5200); define
847 CONFIG_USB_UHCI to enable it.
848 define CONFIG_USB_KEYBOARD to enable the USB Keyboard
849 and define CONFIG_USB_STORAGE to enable the USB
852 Supported are USB Keyboards and USB Floppy drives
854 MPC5200 USB requires additional defines:
856 for 528 MHz Clock: 0x0001bbbb
858 for differential drivers: 0x00001000
859 for single ended drivers: 0x00005000
860 CONFIG_SYS_USB_EVENT_POLL
861 May be defined to allow interrupt polling
862 instead of using asynchronous interrupts
865 Define the below if you wish to use the USB console.
866 Once firmware is rebuilt from a serial console issue the
867 command "setenv stdin usbtty; setenv stdout usbtty" and
868 attach your USB cable. The Unix command "dmesg" should print
869 it has found a new device. The environment variable usbtty
870 can be set to gserial or cdc_acm to enable your device to
871 appear to a USB host as a Linux gserial device or a
872 Common Device Class Abstract Control Model serial device.
873 If you select usbtty = gserial you should be able to enumerate
875 # modprobe usbserial vendor=0xVendorID product=0xProductID
876 else if using cdc_acm, simply setting the environment
877 variable usbtty to be cdc_acm should suffice. The following
878 might be defined in YourBoardName.h
881 Define this to build a UDC device
884 Define this to have a tty type of device available to
885 talk to the UDC device
887 CONFIG_SYS_CONSOLE_IS_IN_ENV
888 Define this if you want stdin, stdout &/or stderr to
892 CONFIG_SYS_USB_EXTC_CLK 0xBLAH
893 Derive USB clock from external clock "blah"
894 - CONFIG_SYS_USB_EXTC_CLK 0x02
896 CONFIG_SYS_USB_BRG_CLK 0xBLAH
897 Derive USB clock from brgclk
898 - CONFIG_SYS_USB_BRG_CLK 0x04
900 If you have a USB-IF assigned VendorID then you may wish to
901 define your own vendor specific values either in BoardName.h
902 or directly in usbd_vendor_info.h. If you don't define
903 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME,
904 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot
905 should pretend to be a Linux device to it's target host.
907 CONFIG_USBD_MANUFACTURER
908 Define this string as the name of your company for
909 - CONFIG_USBD_MANUFACTURER "my company"
911 CONFIG_USBD_PRODUCT_NAME
912 Define this string as the name of your product
913 - CONFIG_USBD_PRODUCT_NAME "acme usb device"
916 Define this as your assigned Vendor ID from the USB
917 Implementors Forum. This *must* be a genuine Vendor ID
918 to avoid polluting the USB namespace.
919 - CONFIG_USBD_VENDORID 0xFFFF
921 CONFIG_USBD_PRODUCTID
922 Define this as the unique Product ID
924 - CONFIG_USBD_PRODUCTID 0xFFFF
928 The MMC controller on the Intel PXA is supported. To
929 enable this define CONFIG_MMC. The MMC can be
930 accessed from the boot prompt by mapping the device
931 to physical memory similar to flash. Command line is
932 enabled with CONFIG_CMD_MMC. The MMC driver also works with
933 the FAT fs. This is enabled with CONFIG_CMD_FAT.
935 - Journaling Flash filesystem support:
936 CONFIG_JFFS2_NAND, CONFIG_JFFS2_NAND_OFF, CONFIG_JFFS2_NAND_SIZE,
937 CONFIG_JFFS2_NAND_DEV
938 Define these for a default partition on a NAND device
940 CONFIG_SYS_JFFS2_FIRST_SECTOR,
941 CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS
942 Define these for a default partition on a NOR device
944 CONFIG_SYS_JFFS_CUSTOM_PART
945 Define this to create an own partition. You have to provide a
946 function struct part_info* jffs2_part_info(int part_num)
948 If you define only one JFFS2 partition you may also want to
949 #define CONFIG_SYS_JFFS_SINGLE_PART 1
950 to disable the command chpart. This is the default when you
951 have not defined a custom partition
956 Define this to enable standard (PC-Style) keyboard
960 Standard PC keyboard driver with US (is default) and
961 GERMAN key layout (switch via environment 'keymap=de') support.
962 Export function i8042_kbd_init, i8042_tstc and i8042_getc
963 for cfb_console. Supports cursor blinking.
968 Define this to enable video support (for output to
973 Enable Chips & Technologies 69000 Video chip
975 CONFIG_VIDEO_SMI_LYNXEM
976 Enable Silicon Motion SMI 712/710/810 Video chip. The
977 video output is selected via environment 'videoout'
978 (1 = LCD and 2 = CRT). If videoout is undefined, CRT is
981 For the CT69000 and SMI_LYNXEM drivers, videomode is
982 selected via environment 'videomode'. Two different ways
984 - "videomode=num" 'num' is a standard LiLo mode numbers.
985 Following standard modes are supported (* is default):
987 Colors 640x480 800x600 1024x768 1152x864 1280x1024
988 -------------+---------------------------------------------
989 8 bits | 0x301* 0x303 0x305 0x161 0x307
990 15 bits | 0x310 0x313 0x316 0x162 0x319
991 16 bits | 0x311 0x314 0x317 0x163 0x31A
992 24 bits | 0x312 0x315 0x318 ? 0x31B
993 -------------+---------------------------------------------
994 (i.e. setenv videomode 317; saveenv; reset;)
996 - "videomode=bootargs" all the video parameters are parsed
997 from the bootargs. (See drivers/video/videomodes.c)
1000 CONFIG_VIDEO_SED13806
1001 Enable Epson SED13806 driver. This driver supports 8bpp
1002 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP
1003 or CONFIG_VIDEO_SED13806_16BPP
1008 Define this to enable a custom keyboard support.
1009 This simply calls drv_keyboard_init() which must be
1010 defined in your board-specific files.
1011 The only board using this so far is RBC823.
1013 - LCD Support: CONFIG_LCD
1015 Define this to enable LCD support (for output to LCD
1016 display); also select one of the supported displays
1017 by defining one of these:
1021 HITACHI TX09D70VM1CCA, 3.5", 240x320.
1023 CONFIG_NEC_NL6448AC33:
1025 NEC NL6448AC33-18. Active, color, single scan.
1027 CONFIG_NEC_NL6448BC20
1029 NEC NL6448BC20-08. 6.5", 640x480.
1030 Active, color, single scan.
1032 CONFIG_NEC_NL6448BC33_54
1034 NEC NL6448BC33-54. 10.4", 640x480.
1035 Active, color, single scan.
1039 Sharp 320x240. Active, color, single scan.
1040 It isn't 16x9, and I am not sure what it is.
1042 CONFIG_SHARP_LQ64D341
1044 Sharp LQ64D341 display, 640x480.
1045 Active, color, single scan.
1049 HLD1045 display, 640x480.
1050 Active, color, single scan.
1054 Optrex CBL50840-2 NF-FW 99 22 M5
1056 Hitachi LMG6912RPFC-00T
1060 320x240. Black & white.
1062 Normally display is black on white background; define
1063 CONFIG_SYS_WHITE_ON_BLACK to get it inverted.
1065 - Splash Screen Support: CONFIG_SPLASH_SCREEN
1067 If this option is set, the environment is checked for
1068 a variable "splashimage". If found, the usual display
1069 of logo, copyright and system information on the LCD
1070 is suppressed and the BMP image at the address
1071 specified in "splashimage" is loaded instead. The
1072 console is redirected to the "nulldev", too. This
1073 allows for a "silent" boot where a splash screen is
1074 loaded very quickly after power-on.
1076 CONFIG_SPLASH_SCREEN_ALIGN
1078 If this option is set the splash image can be freely positioned
1079 on the screen. Environment variable "splashpos" specifies the
1080 position as "x,y". If a positive number is given it is used as
1081 number of pixel from left/top. If a negative number is given it
1082 is used as number of pixel from right/bottom. You can also
1083 specify 'm' for centering the image.
1086 setenv splashpos m,m
1087 => image at center of screen
1089 setenv splashpos 30,20
1090 => image at x = 30 and y = 20
1092 setenv splashpos -10,m
1093 => vertically centered image
1094 at x = dspWidth - bmpWidth - 9
1096 - Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP
1098 If this option is set, additionally to standard BMP
1099 images, gzipped BMP images can be displayed via the
1100 splashscreen support or the bmp command.
1102 - Compression support:
1105 If this option is set, support for bzip2 compressed
1106 images is included. If not, only uncompressed and gzip
1107 compressed images are supported.
1109 NOTE: the bzip2 algorithm requires a lot of RAM, so
1110 the malloc area (as defined by CONFIG_SYS_MALLOC_LEN) should
1115 If this option is set, support for lzma compressed
1118 Note: The LZMA algorithm adds between 2 and 4KB of code and it
1119 requires an amount of dynamic memory that is given by the
1122 (1846 + 768 << (lc + lp)) * sizeof(uint16)
1124 Where lc and lp stand for, respectively, Literal context bits
1125 and Literal pos bits.
1127 This value is upper-bounded by 14MB in the worst case. Anyway,
1128 for a ~4MB large kernel image, we have lc=3 and lp=0 for a
1129 total amount of (1846 + 768 << (3 + 0)) * 2 = ~41KB... that is
1130 a very small buffer.
1132 Use the lzmainfo tool to determinate the lc and lp values and
1133 then calculate the amount of needed dynamic memory (ensuring
1134 the appropriate CONFIG_SYS_MALLOC_LEN value).
1139 The address of PHY on MII bus.
1141 CONFIG_PHY_CLOCK_FREQ (ppc4xx)
1143 The clock frequency of the MII bus
1147 If this option is set, support for speed/duplex
1148 detection of gigabit PHY is included.
1150 CONFIG_PHY_RESET_DELAY
1152 Some PHY like Intel LXT971A need extra delay after
1153 reset before any MII register access is possible.
1154 For such PHY, set this option to the usec delay
1155 required. (minimum 300usec for LXT971A)
1157 CONFIG_PHY_CMD_DELAY (ppc4xx)
1159 Some PHY like Intel LXT971A need extra delay after
1160 command issued before MII status register can be read
1170 Define a default value for Ethernet address to use
1171 for the respective Ethernet interface, in case this
1172 is not determined automatically.
1177 Define a default value for the IP address to use for
1178 the default Ethernet interface, in case this is not
1179 determined through e.g. bootp.
1181 - Server IP address:
1184 Defines a default value for the IP address of a TFTP
1185 server to contact when using the "tftboot" command.
1187 - Multicast TFTP Mode:
1190 Defines whether you want to support multicast TFTP as per
1191 rfc-2090; for example to work with atftp. Lets lots of targets
1192 tftp down the same boot image concurrently. Note: the Ethernet
1193 driver in use must provide a function: mcast() to join/leave a
1196 CONFIG_BOOTP_RANDOM_DELAY
1197 - BOOTP Recovery Mode:
1198 CONFIG_BOOTP_RANDOM_DELAY
1200 If you have many targets in a network that try to
1201 boot using BOOTP, you may want to avoid that all
1202 systems send out BOOTP requests at precisely the same
1203 moment (which would happen for instance at recovery
1204 from a power failure, when all systems will try to
1205 boot, thus flooding the BOOTP server. Defining
1206 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
1207 inserted before sending out BOOTP requests. The
1208 following delays are inserted then:
1210 1st BOOTP request: delay 0 ... 1 sec
1211 2nd BOOTP request: delay 0 ... 2 sec
1212 3rd BOOTP request: delay 0 ... 4 sec
1214 BOOTP requests: delay 0 ... 8 sec
1216 - DHCP Advanced Options:
1217 You can fine tune the DHCP functionality by defining
1218 CONFIG_BOOTP_* symbols:
1220 CONFIG_BOOTP_SUBNETMASK
1221 CONFIG_BOOTP_GATEWAY
1222 CONFIG_BOOTP_HOSTNAME
1223 CONFIG_BOOTP_NISDOMAIN
1224 CONFIG_BOOTP_BOOTPATH
1225 CONFIG_BOOTP_BOOTFILESIZE
1228 CONFIG_BOOTP_SEND_HOSTNAME
1229 CONFIG_BOOTP_NTPSERVER
1230 CONFIG_BOOTP_TIMEOFFSET
1231 CONFIG_BOOTP_VENDOREX
1233 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip
1234 environment variable, not the BOOTP server.
1236 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS
1237 serverip from a DHCP server, it is possible that more
1238 than one DNS serverip is offered to the client.
1239 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS
1240 serverip will be stored in the additional environment
1241 variable "dnsip2". The first DNS serverip is always
1242 stored in the variable "dnsip", when CONFIG_BOOTP_DNS
1245 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable
1246 to do a dynamic update of a DNS server. To do this, they
1247 need the hostname of the DHCP requester.
1248 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content
1249 of the "hostname" environment variable is passed as
1250 option 12 to the DHCP server.
1252 CONFIG_BOOTP_DHCP_REQUEST_DELAY
1254 A 32bit value in microseconds for a delay between
1255 receiving a "DHCP Offer" and sending the "DHCP Request".
1256 This fixes a problem with certain DHCP servers that don't
1257 respond 100% of the time to a "DHCP request". E.g. On an
1258 AT91RM9200 processor running at 180MHz, this delay needed
1259 to be *at least* 15,000 usec before a Windows Server 2003
1260 DHCP server would reply 100% of the time. I recommend at
1261 least 50,000 usec to be safe. The alternative is to hope
1262 that one of the retries will be successful but note that
1263 the DHCP timeout and retry process takes a longer than
1267 CONFIG_CDP_DEVICE_ID
1269 The device id used in CDP trigger frames.
1271 CONFIG_CDP_DEVICE_ID_PREFIX
1273 A two character string which is prefixed to the MAC address
1278 A printf format string which contains the ascii name of
1279 the port. Normally is set to "eth%d" which sets
1280 eth0 for the first Ethernet, eth1 for the second etc.
1282 CONFIG_CDP_CAPABILITIES
1284 A 32bit integer which indicates the device capabilities;
1285 0x00000010 for a normal host which does not forwards.
1289 An ascii string containing the version of the software.
1293 An ascii string containing the name of the platform.
1297 A 32bit integer sent on the trigger.
1299 CONFIG_CDP_POWER_CONSUMPTION
1301 A 16bit integer containing the power consumption of the
1302 device in .1 of milliwatts.
1304 CONFIG_CDP_APPLIANCE_VLAN_TYPE
1306 A byte containing the id of the VLAN.
1308 - Status LED: CONFIG_STATUS_LED
1310 Several configurations allow to display the current
1311 status using a LED. For instance, the LED will blink
1312 fast while running U-Boot code, stop blinking as
1313 soon as a reply to a BOOTP request was received, and
1314 start blinking slow once the Linux kernel is running
1315 (supported by a status LED driver in the Linux
1316 kernel). Defining CONFIG_STATUS_LED enables this
1319 - CAN Support: CONFIG_CAN_DRIVER
1321 Defining CONFIG_CAN_DRIVER enables CAN driver support
1322 on those systems that support this (optional)
1323 feature, like the TQM8xxL modules.
1325 - I2C Support: CONFIG_HARD_I2C | CONFIG_SOFT_I2C
1327 These enable I2C serial bus commands. Defining either of
1328 (but not both of) CONFIG_HARD_I2C or CONFIG_SOFT_I2C will
1329 include the appropriate I2C driver for the selected CPU.
1331 This will allow you to use i2c commands at the u-boot
1332 command line (as long as you set CONFIG_CMD_I2C in
1333 CONFIG_COMMANDS) and communicate with i2c based realtime
1334 clock chips. See common/cmd_i2c.c for a description of the
1335 command line interface.
1337 CONFIG_HARD_I2C selects a hardware I2C controller.
1339 CONFIG_SOFT_I2C configures u-boot to use a software (aka
1340 bit-banging) driver instead of CPM or similar hardware
1343 There are several other quantities that must also be
1344 defined when you define CONFIG_HARD_I2C or CONFIG_SOFT_I2C.
1346 In both cases you will need to define CONFIG_SYS_I2C_SPEED
1347 to be the frequency (in Hz) at which you wish your i2c bus
1348 to run and CONFIG_SYS_I2C_SLAVE to be the address of this node (ie
1349 the CPU's i2c node address).
1351 Now, the u-boot i2c code for the mpc8xx (cpu/mpc8xx/i2c.c)
1352 sets the CPU up as a master node and so its address should
1353 therefore be cleared to 0 (See, eg, MPC823e User's Manual
1354 p.16-473). So, set CONFIG_SYS_I2C_SLAVE to 0.
1356 That's all that's required for CONFIG_HARD_I2C.
1358 If you use the software i2c interface (CONFIG_SOFT_I2C)
1359 then the following macros need to be defined (examples are
1360 from include/configs/lwmon.h):
1364 (Optional). Any commands necessary to enable the I2C
1365 controller or configure ports.
1367 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
1371 (Only for MPC8260 CPU). The I/O port to use (the code
1372 assumes both bits are on the same port). Valid values
1373 are 0..3 for ports A..D.
1377 The code necessary to make the I2C data line active
1378 (driven). If the data line is open collector, this
1381 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
1385 The code necessary to make the I2C data line tri-stated
1386 (inactive). If the data line is open collector, this
1389 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
1393 Code that returns TRUE if the I2C data line is high,
1396 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
1400 If <bit> is TRUE, sets the I2C data line high. If it
1401 is FALSE, it clears it (low).
1403 eg: #define I2C_SDA(bit) \
1404 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
1405 else immr->im_cpm.cp_pbdat &= ~PB_SDA
1409 If <bit> is TRUE, sets the I2C clock line high. If it
1410 is FALSE, it clears it (low).
1412 eg: #define I2C_SCL(bit) \
1413 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
1414 else immr->im_cpm.cp_pbdat &= ~PB_SCL
1418 This delay is invoked four times per clock cycle so this
1419 controls the rate of data transfer. The data rate thus
1420 is 1 / (I2C_DELAY * 4). Often defined to be something
1423 #define I2C_DELAY udelay(2)
1425 CONFIG_SYS_I2C_INIT_BOARD
1427 When a board is reset during an i2c bus transfer
1428 chips might think that the current transfer is still
1429 in progress. On some boards it is possible to access
1430 the i2c SCLK line directly, either by using the
1431 processor pin as a GPIO or by having a second pin
1432 connected to the bus. If this option is defined a
1433 custom i2c_init_board() routine in boards/xxx/board.c
1434 is run early in the boot sequence.
1436 CONFIG_I2CFAST (PPC405GP|PPC405EP only)
1438 This option enables configuration of bi_iic_fast[] flags
1439 in u-boot bd_info structure based on u-boot environment
1440 variable "i2cfast". (see also i2cfast)
1442 CONFIG_I2C_MULTI_BUS
1444 This option allows the use of multiple I2C buses, each of which
1445 must have a controller. At any point in time, only one bus is
1446 active. To switch to a different bus, use the 'i2c dev' command.
1447 Note that bus numbering is zero-based.
1449 CONFIG_SYS_I2C_NOPROBES
1451 This option specifies a list of I2C devices that will be skipped
1452 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS
1453 is set, specify a list of bus-device pairs. Otherwise, specify
1454 a 1D array of device addresses
1457 #undef CONFIG_I2C_MULTI_BUS
1458 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68}
1460 will skip addresses 0x50 and 0x68 on a board with one I2C bus
1462 #define CONFIG_I2C_MULTI_BUS
1463 #define CONFIG_SYS_I2C_MULTI_NOPROBES {{0,0x50},{0,0x68},{1,0x54}}
1465 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1
1467 CONFIG_SYS_SPD_BUS_NUM
1469 If defined, then this indicates the I2C bus number for DDR SPD.
1470 If not defined, then U-Boot assumes that SPD is on I2C bus 0.
1472 CONFIG_SYS_RTC_BUS_NUM
1474 If defined, then this indicates the I2C bus number for the RTC.
1475 If not defined, then U-Boot assumes that RTC is on I2C bus 0.
1477 CONFIG_SYS_DTT_BUS_NUM
1479 If defined, then this indicates the I2C bus number for the DTT.
1480 If not defined, then U-Boot assumes that DTT is on I2C bus 0.
1482 CONFIG_SYS_I2C_DTT_ADDR:
1484 If defined, specifies the I2C address of the DTT device.
1485 If not defined, then U-Boot uses predefined value for
1486 specified DTT device.
1490 Define this option if you want to use Freescale's I2C driver in
1491 drivers/i2c/fsl_i2c.c.
1495 Define this option if you have I2C devices reached over 1 .. n
1496 I2C Muxes like the pca9544a. This option addes a new I2C
1497 Command "i2c bus [muxtype:muxaddr:muxchannel]" which adds a
1498 new I2C Bus to the existing I2C Busses. If you select the
1499 new Bus with "i2c dev", u-bbot sends first the commandos for
1500 the muxes to activate this new "bus".
1502 CONFIG_I2C_MULTI_BUS must be also defined, to use this
1506 Adding a new I2C Bus reached over 2 pca9544a muxes
1507 The First mux with address 70 and channel 6
1508 The Second mux with address 71 and channel 4
1510 => i2c bus pca9544a:70:6:pca9544a:71:4
1512 Use the "i2c bus" command without parameter, to get a list
1513 of I2C Busses with muxes:
1516 Busses reached over muxes:
1518 reached over Mux(es):
1521 reached over Mux(es):
1526 If you now switch to the new I2C Bus 3 with "i2c dev 3"
1527 u-boot sends First the Commando to the mux@70 to enable
1528 channel 6, and then the Commando to the mux@71 to enable
1531 After that, you can use the "normal" i2c commands as
1532 usual, to communicate with your I2C devices behind
1535 This option is actually implemented for the bitbanging
1536 algorithm in common/soft_i2c.c and for the Hardware I2C
1537 Bus on the MPC8260. But it should be not so difficult
1538 to add this option to other architectures.
1540 CONFIG_SOFT_I2C_READ_REPEATED_START
1542 defining this will force the i2c_read() function in
1543 the soft_i2c driver to perform an I2C repeated start
1544 between writing the address pointer and reading the
1545 data. If this define is omitted the default behaviour
1546 of doing a stop-start sequence will be used. Most I2C
1547 devices can use either method, but some require one or
1550 - SPI Support: CONFIG_SPI
1552 Enables SPI driver (so far only tested with
1553 SPI EEPROM, also an instance works with Crystal A/D and
1554 D/As on the SACSng board)
1558 Enables extended (16-bit) SPI EEPROM addressing.
1559 (symmetrical to CONFIG_I2C_X)
1563 Enables a software (bit-bang) SPI driver rather than
1564 using hardware support. This is a general purpose
1565 driver that only requires three general I/O port pins
1566 (two outputs, one input) to function. If this is
1567 defined, the board configuration must define several
1568 SPI configuration items (port pins to use, etc). For
1569 an example, see include/configs/sacsng.h.
1573 Enables a hardware SPI driver for general-purpose reads
1574 and writes. As with CONFIG_SOFT_SPI, the board configuration
1575 must define a list of chip-select function pointers.
1576 Currently supported on some MPC8xxx processors. For an
1577 example, see include/configs/mpc8349emds.h.
1581 Enables the driver for the SPI controllers on i.MX and MXC
1582 SoCs. Currently only i.MX31 is supported.
1584 - FPGA Support: CONFIG_FPGA
1586 Enables FPGA subsystem.
1588 CONFIG_FPGA_<vendor>
1590 Enables support for specific chip vendors.
1593 CONFIG_FPGA_<family>
1595 Enables support for FPGA family.
1596 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX)
1600 Specify the number of FPGA devices to support.
1602 CONFIG_SYS_FPGA_PROG_FEEDBACK
1604 Enable printing of hash marks during FPGA configuration.
1606 CONFIG_SYS_FPGA_CHECK_BUSY
1608 Enable checks on FPGA configuration interface busy
1609 status by the configuration function. This option
1610 will require a board or device specific function to
1615 If defined, a function that provides delays in the FPGA
1616 configuration driver.
1618 CONFIG_SYS_FPGA_CHECK_CTRLC
1619 Allow Control-C to interrupt FPGA configuration
1621 CONFIG_SYS_FPGA_CHECK_ERROR
1623 Check for configuration errors during FPGA bitfile
1624 loading. For example, abort during Virtex II
1625 configuration if the INIT_B line goes low (which
1626 indicated a CRC error).
1628 CONFIG_SYS_FPGA_WAIT_INIT
1630 Maximum time to wait for the INIT_B line to deassert
1631 after PROB_B has been deasserted during a Virtex II
1632 FPGA configuration sequence. The default time is 500
1635 CONFIG_SYS_FPGA_WAIT_BUSY
1637 Maximum time to wait for BUSY to deassert during
1638 Virtex II FPGA configuration. The default is 5 ms.
1640 CONFIG_SYS_FPGA_WAIT_CONFIG
1642 Time to wait after FPGA configuration. The default is
1645 - Configuration Management:
1648 If defined, this string will be added to the U-Boot
1649 version information (U_BOOT_VERSION)
1651 - Vendor Parameter Protection:
1653 U-Boot considers the values of the environment
1654 variables "serial#" (Board Serial Number) and
1655 "ethaddr" (Ethernet Address) to be parameters that
1656 are set once by the board vendor / manufacturer, and
1657 protects these variables from casual modification by
1658 the user. Once set, these variables are read-only,
1659 and write or delete attempts are rejected. You can
1660 change this behaviour:
1662 If CONFIG_ENV_OVERWRITE is #defined in your config
1663 file, the write protection for vendor parameters is
1664 completely disabled. Anybody can change or delete
1667 Alternatively, if you #define _both_ CONFIG_ETHADDR
1668 _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
1669 Ethernet address is installed in the environment,
1670 which can be changed exactly ONCE by the user. [The
1671 serial# is unaffected by this, i. e. it remains
1677 Define this variable to enable the reservation of
1678 "protected RAM", i. e. RAM which is not overwritten
1679 by U-Boot. Define CONFIG_PRAM to hold the number of
1680 kB you want to reserve for pRAM. You can overwrite
1681 this default value by defining an environment
1682 variable "pram" to the number of kB you want to
1683 reserve. Note that the board info structure will
1684 still show the full amount of RAM. If pRAM is
1685 reserved, a new environment variable "mem" will
1686 automatically be defined to hold the amount of
1687 remaining RAM in a form that can be passed as boot
1688 argument to Linux, for instance like that:
1690 setenv bootargs ... mem=\${mem}
1693 This way you can tell Linux not to use this memory,
1694 either, which results in a memory region that will
1695 not be affected by reboots.
1697 *WARNING* If your board configuration uses automatic
1698 detection of the RAM size, you must make sure that
1699 this memory test is non-destructive. So far, the
1700 following board configurations are known to be
1703 ETX094, IVMS8, IVML24, SPD8xx, TQM8xxL,
1704 HERMES, IP860, RPXlite, LWMON, LANTEC,
1705 PCU_E, FLAGADM, TQM8260
1710 Define this variable to stop the system in case of a
1711 fatal error, so that you have to reset it manually.
1712 This is probably NOT a good idea for an embedded
1713 system where you want the system to reboot
1714 automatically as fast as possible, but it may be
1715 useful during development since you can try to debug
1716 the conditions that lead to the situation.
1718 CONFIG_NET_RETRY_COUNT
1720 This variable defines the number of retries for
1721 network operations like ARP, RARP, TFTP, or BOOTP
1722 before giving up the operation. If not defined, a
1723 default value of 5 is used.
1727 Timeout waiting for an ARP reply in milliseconds.
1729 - Command Interpreter:
1730 CONFIG_AUTO_COMPLETE
1732 Enable auto completion of commands using TAB.
1734 Note that this feature has NOT been implemented yet
1735 for the "hush" shell.
1738 CONFIG_SYS_HUSH_PARSER
1740 Define this variable to enable the "hush" shell (from
1741 Busybox) as command line interpreter, thus enabling
1742 powerful command line syntax like
1743 if...then...else...fi conditionals or `&&' and '||'
1744 constructs ("shell scripts").
1746 If undefined, you get the old, much simpler behaviour
1747 with a somewhat smaller memory footprint.
1750 CONFIG_SYS_PROMPT_HUSH_PS2
1752 This defines the secondary prompt string, which is
1753 printed when the command interpreter needs more input
1754 to complete a command. Usually "> ".
1758 In the current implementation, the local variables
1759 space and global environment variables space are
1760 separated. Local variables are those you define by
1761 simply typing `name=value'. To access a local
1762 variable later on, you have write `$name' or
1763 `${name}'; to execute the contents of a variable
1764 directly type `$name' at the command prompt.
1766 Global environment variables are those you use
1767 setenv/printenv to work with. To run a command stored
1768 in such a variable, you need to use the run command,
1769 and you must not use the '$' sign to access them.
1771 To store commands and special characters in a
1772 variable, please use double quotation marks
1773 surrounding the whole text of the variable, instead
1774 of the backslashes before semicolons and special
1777 - Commandline Editing and History:
1778 CONFIG_CMDLINE_EDITING
1780 Enable editing and History functions for interactive
1781 commandline input operations
1783 - Default Environment:
1784 CONFIG_EXTRA_ENV_SETTINGS
1786 Define this to contain any number of null terminated
1787 strings (variable = value pairs) that will be part of
1788 the default environment compiled into the boot image.
1790 For example, place something like this in your
1791 board's config file:
1793 #define CONFIG_EXTRA_ENV_SETTINGS \
1797 Warning: This method is based on knowledge about the
1798 internal format how the environment is stored by the
1799 U-Boot code. This is NOT an official, exported
1800 interface! Although it is unlikely that this format
1801 will change soon, there is no guarantee either.
1802 You better know what you are doing here.
1804 Note: overly (ab)use of the default environment is
1805 discouraged. Make sure to check other ways to preset
1806 the environment like the "source" command or the
1809 - DataFlash Support:
1810 CONFIG_HAS_DATAFLASH
1812 Defining this option enables DataFlash features and
1813 allows to read/write in Dataflash via the standard
1816 - SystemACE Support:
1819 Adding this option adds support for Xilinx SystemACE
1820 chips attached via some sort of local bus. The address
1821 of the chip must also be defined in the
1822 CONFIG_SYS_SYSTEMACE_BASE macro. For example:
1824 #define CONFIG_SYSTEMACE
1825 #define CONFIG_SYS_SYSTEMACE_BASE 0xf0000000
1827 When SystemACE support is added, the "ace" device type
1828 becomes available to the fat commands, i.e. fatls.
1830 - TFTP Fixed UDP Port:
1833 If this is defined, the environment variable tftpsrcp
1834 is used to supply the TFTP UDP source port value.
1835 If tftpsrcp isn't defined, the normal pseudo-random port
1836 number generator is used.
1838 Also, the environment variable tftpdstp is used to supply
1839 the TFTP UDP destination port value. If tftpdstp isn't
1840 defined, the normal port 69 is used.
1842 The purpose for tftpsrcp is to allow a TFTP server to
1843 blindly start the TFTP transfer using the pre-configured
1844 target IP address and UDP port. This has the effect of
1845 "punching through" the (Windows XP) firewall, allowing
1846 the remainder of the TFTP transfer to proceed normally.
1847 A better solution is to properly configure the firewall,
1848 but sometimes that is not allowed.
1850 - Show boot progress:
1851 CONFIG_SHOW_BOOT_PROGRESS
1853 Defining this option allows to add some board-
1854 specific code (calling a user-provided function
1855 "show_boot_progress(int)") that enables you to show
1856 the system's boot progress on some display (for
1857 example, some LED's) on your board. At the moment,
1858 the following checkpoints are implemented:
1860 - Automatic software updates via TFTP server
1862 CONFIG_UPDATE_TFTP_CNT_MAX
1863 CONFIG_UPDATE_TFTP_MSEC_MAX
1865 These options enable and control the auto-update feature;
1866 for a more detailed description refer to doc/README.update.
1868 - MTD Support (mtdparts command, UBI support)
1871 Adds the MTD device infrastructure from the Linux kernel.
1872 Needed for mtdparts command support.
1874 CONFIG_MTD_PARTITIONS
1876 Adds the MTD partitioning infrastructure from the Linux
1877 kernel. Needed for UBI support.
1879 Legacy uImage format:
1882 1 common/cmd_bootm.c before attempting to boot an image
1883 -1 common/cmd_bootm.c Image header has bad magic number
1884 2 common/cmd_bootm.c Image header has correct magic number
1885 -2 common/cmd_bootm.c Image header has bad checksum
1886 3 common/cmd_bootm.c Image header has correct checksum
1887 -3 common/cmd_bootm.c Image data has bad checksum
1888 4 common/cmd_bootm.c Image data has correct checksum
1889 -4 common/cmd_bootm.c Image is for unsupported architecture
1890 5 common/cmd_bootm.c Architecture check OK
1891 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi)
1892 6 common/cmd_bootm.c Image Type check OK
1893 -6 common/cmd_bootm.c gunzip uncompression error
1894 -7 common/cmd_bootm.c Unimplemented compression type
1895 7 common/cmd_bootm.c Uncompression OK
1896 8 common/cmd_bootm.c No uncompress/copy overwrite error
1897 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX)
1899 9 common/image.c Start initial ramdisk verification
1900 -10 common/image.c Ramdisk header has bad magic number
1901 -11 common/image.c Ramdisk header has bad checksum
1902 10 common/image.c Ramdisk header is OK
1903 -12 common/image.c Ramdisk data has bad checksum
1904 11 common/image.c Ramdisk data has correct checksum
1905 12 common/image.c Ramdisk verification complete, start loading
1906 -13 common/image.c Wrong Image Type (not PPC Linux ramdisk)
1907 13 common/image.c Start multifile image verification
1908 14 common/image.c No initial ramdisk, no multifile, continue.
1910 15 lib_<arch>/bootm.c All preparation done, transferring control to OS
1912 -30 lib_ppc/board.c Fatal error, hang the system
1913 -31 post/post.c POST test failed, detected by post_output_backlog()
1914 -32 post/post.c POST test failed, detected by post_run_single()
1916 34 common/cmd_doc.c before loading a Image from a DOC device
1917 -35 common/cmd_doc.c Bad usage of "doc" command
1918 35 common/cmd_doc.c correct usage of "doc" command
1919 -36 common/cmd_doc.c No boot device
1920 36 common/cmd_doc.c correct boot device
1921 -37 common/cmd_doc.c Unknown Chip ID on boot device
1922 37 common/cmd_doc.c correct chip ID found, device available
1923 -38 common/cmd_doc.c Read Error on boot device
1924 38 common/cmd_doc.c reading Image header from DOC device OK
1925 -39 common/cmd_doc.c Image header has bad magic number
1926 39 common/cmd_doc.c Image header has correct magic number
1927 -40 common/cmd_doc.c Error reading Image from DOC device
1928 40 common/cmd_doc.c Image header has correct magic number
1929 41 common/cmd_ide.c before loading a Image from a IDE device
1930 -42 common/cmd_ide.c Bad usage of "ide" command
1931 42 common/cmd_ide.c correct usage of "ide" command
1932 -43 common/cmd_ide.c No boot device
1933 43 common/cmd_ide.c boot device found
1934 -44 common/cmd_ide.c Device not available
1935 44 common/cmd_ide.c Device available
1936 -45 common/cmd_ide.c wrong partition selected
1937 45 common/cmd_ide.c partition selected
1938 -46 common/cmd_ide.c Unknown partition table
1939 46 common/cmd_ide.c valid partition table found
1940 -47 common/cmd_ide.c Invalid partition type
1941 47 common/cmd_ide.c correct partition type
1942 -48 common/cmd_ide.c Error reading Image Header on boot device
1943 48 common/cmd_ide.c reading Image Header from IDE device OK
1944 -49 common/cmd_ide.c Image header has bad magic number
1945 49 common/cmd_ide.c Image header has correct magic number
1946 -50 common/cmd_ide.c Image header has bad checksum
1947 50 common/cmd_ide.c Image header has correct checksum
1948 -51 common/cmd_ide.c Error reading Image from IDE device
1949 51 common/cmd_ide.c reading Image from IDE device OK
1950 52 common/cmd_nand.c before loading a Image from a NAND device
1951 -53 common/cmd_nand.c Bad usage of "nand" command
1952 53 common/cmd_nand.c correct usage of "nand" command
1953 -54 common/cmd_nand.c No boot device
1954 54 common/cmd_nand.c boot device found
1955 -55 common/cmd_nand.c Unknown Chip ID on boot device
1956 55 common/cmd_nand.c correct chip ID found, device available
1957 -56 common/cmd_nand.c Error reading Image Header on boot device
1958 56 common/cmd_nand.c reading Image Header from NAND device OK
1959 -57 common/cmd_nand.c Image header has bad magic number
1960 57 common/cmd_nand.c Image header has correct magic number
1961 -58 common/cmd_nand.c Error reading Image from NAND device
1962 58 common/cmd_nand.c reading Image from NAND device OK
1964 -60 common/env_common.c Environment has a bad CRC, using default
1966 64 net/eth.c starting with Ethernet configuration.
1967 -64 net/eth.c no Ethernet found.
1968 65 net/eth.c Ethernet found.
1970 -80 common/cmd_net.c usage wrong
1971 80 common/cmd_net.c before calling NetLoop()
1972 -81 common/cmd_net.c some error in NetLoop() occurred
1973 81 common/cmd_net.c NetLoop() back without error
1974 -82 common/cmd_net.c size == 0 (File with size 0 loaded)
1975 82 common/cmd_net.c trying automatic boot
1976 83 common/cmd_net.c running "source" command
1977 -83 common/cmd_net.c some error in automatic boot or "source" command
1978 84 common/cmd_net.c end without errors
1983 100 common/cmd_bootm.c Kernel FIT Image has correct format
1984 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format
1985 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration
1986 -101 common/cmd_bootm.c Can't get configuration for kernel subimage
1987 102 common/cmd_bootm.c Kernel unit name specified
1988 -103 common/cmd_bootm.c Can't get kernel subimage node offset
1989 103 common/cmd_bootm.c Found configuration node
1990 104 common/cmd_bootm.c Got kernel subimage node offset
1991 -104 common/cmd_bootm.c Kernel subimage hash verification failed
1992 105 common/cmd_bootm.c Kernel subimage hash verification OK
1993 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture
1994 106 common/cmd_bootm.c Architecture check OK
1995 -106 common/cmd_bootm.c Kernel subimage has wrong type
1996 107 common/cmd_bootm.c Kernel subimage type OK
1997 -107 common/cmd_bootm.c Can't get kernel subimage data/size
1998 108 common/cmd_bootm.c Got kernel subimage data/size
1999 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT)
2000 -109 common/cmd_bootm.c Can't get kernel subimage type
2001 -110 common/cmd_bootm.c Can't get kernel subimage comp
2002 -111 common/cmd_bootm.c Can't get kernel subimage os
2003 -112 common/cmd_bootm.c Can't get kernel subimage load address
2004 -113 common/cmd_bootm.c Image uncompress/copy overwrite error
2006 120 common/image.c Start initial ramdisk verification
2007 -120 common/image.c Ramdisk FIT image has incorrect format
2008 121 common/image.c Ramdisk FIT image has correct format
2009 122 common/image.c No ramdisk subimage unit name, using configuration
2010 -122 common/image.c Can't get configuration for ramdisk subimage
2011 123 common/image.c Ramdisk unit name specified
2012 -124 common/image.c Can't get ramdisk subimage node offset
2013 125 common/image.c Got ramdisk subimage node offset
2014 -125 common/image.c Ramdisk subimage hash verification failed
2015 126 common/image.c Ramdisk subimage hash verification OK
2016 -126 common/image.c Ramdisk subimage for unsupported architecture
2017 127 common/image.c Architecture check OK
2018 -127 common/image.c Can't get ramdisk subimage data/size
2019 128 common/image.c Got ramdisk subimage data/size
2020 129 common/image.c Can't get ramdisk load address
2021 -129 common/image.c Got ramdisk load address
2023 -130 common/cmd_doc.c Incorrect FIT image format
2024 131 common/cmd_doc.c FIT image format OK
2026 -140 common/cmd_ide.c Incorrect FIT image format
2027 141 common/cmd_ide.c FIT image format OK
2029 -150 common/cmd_nand.c Incorrect FIT image format
2030 151 common/cmd_nand.c FIT image format OK
2036 [so far only for SMDK2400 and TRAB boards]
2038 - Modem support enable:
2039 CONFIG_MODEM_SUPPORT
2041 - RTS/CTS Flow control enable:
2044 - Modem debug support:
2045 CONFIG_MODEM_SUPPORT_DEBUG
2047 Enables debugging stuff (char screen[1024], dbg())
2048 for modem support. Useful only with BDI2000.
2050 - Interrupt support (PPC):
2052 There are common interrupt_init() and timer_interrupt()
2053 for all PPC archs. interrupt_init() calls interrupt_init_cpu()
2054 for CPU specific initialization. interrupt_init_cpu()
2055 should set decrementer_count to appropriate value. If
2056 CPU resets decrementer automatically after interrupt
2057 (ppc4xx) it should set decrementer_count to zero.
2058 timer_interrupt() calls timer_interrupt_cpu() for CPU
2059 specific handling. If board has watchdog / status_led
2060 / other_activity_monitor it works automatically from
2061 general timer_interrupt().
2065 In the target system modem support is enabled when a
2066 specific key (key combination) is pressed during
2067 power-on. Otherwise U-Boot will boot normally
2068 (autoboot). The key_pressed() function is called from
2069 board_init(). Currently key_pressed() is a dummy
2070 function, returning 1 and thus enabling modem
2073 If there are no modem init strings in the
2074 environment, U-Boot proceed to autoboot; the
2075 previous output (banner, info printfs) will be
2078 See also: doc/README.Modem
2081 Configuration Settings:
2082 -----------------------
2084 - CONFIG_SYS_LONGHELP: Defined when you want long help messages included;
2085 undefine this when you're short of memory.
2087 - CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default
2088 width of the commands listed in the 'help' command output.
2090 - CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to
2091 prompt for user input.
2093 - CONFIG_SYS_CBSIZE: Buffer size for input from the Console
2095 - CONFIG_SYS_PBSIZE: Buffer size for Console output
2097 - CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands
2099 - CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to
2100 the application (usually a Linux kernel) when it is
2103 - CONFIG_SYS_BAUDRATE_TABLE:
2104 List of legal baudrate settings for this board.
2106 - CONFIG_SYS_CONSOLE_INFO_QUIET
2107 Suppress display of console information at boot.
2109 - CONFIG_SYS_CONSOLE_IS_IN_ENV
2110 If the board specific function
2111 extern int overwrite_console (void);
2112 returns 1, the stdin, stderr and stdout are switched to the
2113 serial port, else the settings in the environment are used.
2115 - CONFIG_SYS_CONSOLE_OVERWRITE_ROUTINE
2116 Enable the call to overwrite_console().
2118 - CONFIG_SYS_CONSOLE_ENV_OVERWRITE
2119 Enable overwrite of previous console environment settings.
2121 - CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END:
2122 Begin and End addresses of the area used by the
2125 - CONFIG_SYS_ALT_MEMTEST:
2126 Enable an alternate, more extensive memory test.
2128 - CONFIG_SYS_MEMTEST_SCRATCH:
2129 Scratch address used by the alternate memory test
2130 You only need to set this if address zero isn't writeable
2132 - CONFIG_SYS_MEM_TOP_HIDE (PPC only):
2133 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header,
2134 this specified memory area will get subtracted from the top
2135 (end) of RAM and won't get "touched" at all by U-Boot. By
2136 fixing up gd->ram_size the Linux kernel should gets passed
2137 the now "corrected" memory size and won't touch it either.
2138 This should work for arch/ppc and arch/powerpc. Only Linux
2139 board ports in arch/powerpc with bootwrapper support that
2140 recalculate the memory size from the SDRAM controller setup
2141 will have to get fixed in Linux additionally.
2143 This option can be used as a workaround for the 440EPx/GRx
2144 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't
2147 WARNING: Please make sure that this value is a multiple of
2148 the Linux page size (normally 4k). If this is not the case,
2149 then the end address of the Linux memory will be located at a
2150 non page size aligned address and this could cause major
2153 - CONFIG_SYS_TFTP_LOADADDR:
2154 Default load address for network file downloads
2156 - CONFIG_SYS_LOADS_BAUD_CHANGE:
2157 Enable temporary baudrate change while serial download
2159 - CONFIG_SYS_SDRAM_BASE:
2160 Physical start address of SDRAM. _Must_ be 0 here.
2162 - CONFIG_SYS_MBIO_BASE:
2163 Physical start address of Motherboard I/O (if using a
2166 - CONFIG_SYS_FLASH_BASE:
2167 Physical start address of Flash memory.
2169 - CONFIG_SYS_MONITOR_BASE:
2170 Physical start address of boot monitor code (set by
2171 make config files to be same as the text base address
2172 (TEXT_BASE) used when linking) - same as
2173 CONFIG_SYS_FLASH_BASE when booting from flash.
2175 - CONFIG_SYS_MONITOR_LEN:
2176 Size of memory reserved for monitor code, used to
2177 determine _at_compile_time_ (!) if the environment is
2178 embedded within the U-Boot image, or in a separate
2181 - CONFIG_SYS_MALLOC_LEN:
2182 Size of DRAM reserved for malloc() use.
2184 - CONFIG_SYS_BOOTM_LEN:
2185 Normally compressed uImages are limited to an
2186 uncompressed size of 8 MBytes. If this is not enough,
2187 you can define CONFIG_SYS_BOOTM_LEN in your board config file
2188 to adjust this setting to your needs.
2190 - CONFIG_SYS_BOOTMAPSZ:
2191 Maximum size of memory mapped by the startup code of
2192 the Linux kernel; all data that must be processed by
2193 the Linux kernel (bd_info, boot arguments, FDT blob if
2194 used) must be put below this limit, unless "bootm_low"
2195 enviroment variable is defined and non-zero. In such case
2196 all data for the Linux kernel must be between "bootm_low"
2197 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ.
2199 - CONFIG_SYS_MAX_FLASH_BANKS:
2200 Max number of Flash memory banks
2202 - CONFIG_SYS_MAX_FLASH_SECT:
2203 Max number of sectors on a Flash chip
2205 - CONFIG_SYS_FLASH_ERASE_TOUT:
2206 Timeout for Flash erase operations (in ms)
2208 - CONFIG_SYS_FLASH_WRITE_TOUT:
2209 Timeout for Flash write operations (in ms)
2211 - CONFIG_SYS_FLASH_LOCK_TOUT
2212 Timeout for Flash set sector lock bit operation (in ms)
2214 - CONFIG_SYS_FLASH_UNLOCK_TOUT
2215 Timeout for Flash clear lock bits operation (in ms)
2217 - CONFIG_SYS_FLASH_PROTECTION
2218 If defined, hardware flash sectors protection is used
2219 instead of U-Boot software protection.
2221 - CONFIG_SYS_DIRECT_FLASH_TFTP:
2223 Enable TFTP transfers directly to flash memory;
2224 without this option such a download has to be
2225 performed in two steps: (1) download to RAM, and (2)
2226 copy from RAM to flash.
2228 The two-step approach is usually more reliable, since
2229 you can check if the download worked before you erase
2230 the flash, but in some situations (when system RAM is
2231 too limited to allow for a temporary copy of the
2232 downloaded image) this option may be very useful.
2234 - CONFIG_SYS_FLASH_CFI:
2235 Define if the flash driver uses extra elements in the
2236 common flash structure for storing flash geometry.
2238 - CONFIG_FLASH_CFI_DRIVER
2239 This option also enables the building of the cfi_flash driver
2240 in the drivers directory
2242 - CONFIG_FLASH_CFI_MTD
2243 This option enables the building of the cfi_mtd driver
2244 in the drivers directory. The driver exports CFI flash
2247 - CONFIG_SYS_FLASH_USE_BUFFER_WRITE
2248 Use buffered writes to flash.
2250 - CONFIG_FLASH_SPANSION_S29WS_N
2251 s29ws-n MirrorBit flash has non-standard addresses for buffered
2254 - CONFIG_SYS_FLASH_QUIET_TEST
2255 If this option is defined, the common CFI flash doesn't
2256 print it's warning upon not recognized FLASH banks. This
2257 is useful, if some of the configured banks are only
2258 optionally available.
2260 - CONFIG_FLASH_SHOW_PROGRESS
2261 If defined (must be an integer), print out countdown
2262 digits and dots. Recommended value: 45 (9..1) for 80
2263 column displays, 15 (3..1) for 40 column displays.
2265 - CONFIG_SYS_RX_ETH_BUFFER:
2266 Defines the number of Ethernet receive buffers. On some
2267 Ethernet controllers it is recommended to set this value
2268 to 8 or even higher (EEPRO100 or 405 EMAC), since all
2269 buffers can be full shortly after enabling the interface
2270 on high Ethernet traffic.
2271 Defaults to 4 if not defined.
2273 The following definitions that deal with the placement and management
2274 of environment data (variable area); in general, we support the
2275 following configurations:
2277 - CONFIG_ENV_IS_IN_FLASH:
2279 Define this if the environment is in flash memory.
2281 a) The environment occupies one whole flash sector, which is
2282 "embedded" in the text segment with the U-Boot code. This
2283 happens usually with "bottom boot sector" or "top boot
2284 sector" type flash chips, which have several smaller
2285 sectors at the start or the end. For instance, such a
2286 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In
2287 such a case you would place the environment in one of the
2288 4 kB sectors - with U-Boot code before and after it. With
2289 "top boot sector" type flash chips, you would put the
2290 environment in one of the last sectors, leaving a gap
2291 between U-Boot and the environment.
2293 - CONFIG_ENV_OFFSET:
2295 Offset of environment data (variable area) to the
2296 beginning of flash memory; for instance, with bottom boot
2297 type flash chips the second sector can be used: the offset
2298 for this sector is given here.
2300 CONFIG_ENV_OFFSET is used relative to CONFIG_SYS_FLASH_BASE.
2304 This is just another way to specify the start address of
2305 the flash sector containing the environment (instead of
2308 - CONFIG_ENV_SECT_SIZE:
2310 Size of the sector containing the environment.
2313 b) Sometimes flash chips have few, equal sized, BIG sectors.
2314 In such a case you don't want to spend a whole sector for
2319 If you use this in combination with CONFIG_ENV_IS_IN_FLASH
2320 and CONFIG_ENV_SECT_SIZE, you can specify to use only a part
2321 of this flash sector for the environment. This saves
2322 memory for the RAM copy of the environment.
2324 It may also save flash memory if you decide to use this
2325 when your environment is "embedded" within U-Boot code,
2326 since then the remainder of the flash sector could be used
2327 for U-Boot code. It should be pointed out that this is
2328 STRONGLY DISCOURAGED from a robustness point of view:
2329 updating the environment in flash makes it always
2330 necessary to erase the WHOLE sector. If something goes
2331 wrong before the contents has been restored from a copy in
2332 RAM, your target system will be dead.
2334 - CONFIG_ENV_ADDR_REDUND
2335 CONFIG_ENV_SIZE_REDUND
2337 These settings describe a second storage area used to hold
2338 a redundant copy of the environment data, so that there is
2339 a valid backup copy in case there is a power failure during
2340 a "saveenv" operation.
2342 BE CAREFUL! Any changes to the flash layout, and some changes to the
2343 source code will make it necessary to adapt <board>/u-boot.lds*
2347 - CONFIG_ENV_IS_IN_NVRAM:
2349 Define this if you have some non-volatile memory device
2350 (NVRAM, battery buffered SRAM) which you want to use for the
2356 These two #defines are used to determine the memory area you
2357 want to use for environment. It is assumed that this memory
2358 can just be read and written to, without any special
2361 BE CAREFUL! The first access to the environment happens quite early
2362 in U-Boot initalization (when we try to get the setting of for the
2363 console baudrate). You *MUST* have mapped your NVRAM area then, or
2366 Please note that even with NVRAM we still use a copy of the
2367 environment in RAM: we could work on NVRAM directly, but we want to
2368 keep settings there always unmodified except somebody uses "saveenv"
2369 to save the current settings.
2372 - CONFIG_ENV_IS_IN_EEPROM:
2374 Use this if you have an EEPROM or similar serial access
2375 device and a driver for it.
2377 - CONFIG_ENV_OFFSET:
2380 These two #defines specify the offset and size of the
2381 environment area within the total memory of your EEPROM.
2383 - CONFIG_SYS_I2C_EEPROM_ADDR:
2384 If defined, specified the chip address of the EEPROM device.
2385 The default address is zero.
2387 - CONFIG_SYS_EEPROM_PAGE_WRITE_BITS:
2388 If defined, the number of bits used to address bytes in a
2389 single page in the EEPROM device. A 64 byte page, for example
2390 would require six bits.
2392 - CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS:
2393 If defined, the number of milliseconds to delay between
2394 page writes. The default is zero milliseconds.
2396 - CONFIG_SYS_I2C_EEPROM_ADDR_LEN:
2397 The length in bytes of the EEPROM memory array address. Note
2398 that this is NOT the chip address length!
2400 - CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW:
2401 EEPROM chips that implement "address overflow" are ones
2402 like Catalyst 24WC04/08/16 which has 9/10/11 bits of
2403 address and the extra bits end up in the "chip address" bit
2404 slots. This makes a 24WC08 (1Kbyte) chip look like four 256
2407 Note that we consider the length of the address field to
2408 still be one byte because the extra address bits are hidden
2409 in the chip address.
2411 - CONFIG_SYS_EEPROM_SIZE:
2412 The size in bytes of the EEPROM device.
2415 - CONFIG_ENV_IS_IN_DATAFLASH:
2417 Define this if you have a DataFlash memory device which you
2418 want to use for the environment.
2420 - CONFIG_ENV_OFFSET:
2424 These three #defines specify the offset and size of the
2425 environment area within the total memory of your DataFlash placed
2426 at the specified address.
2428 - CONFIG_ENV_IS_IN_NAND:
2430 Define this if you have a NAND device which you want to use
2431 for the environment.
2433 - CONFIG_ENV_OFFSET:
2436 These two #defines specify the offset and size of the environment
2437 area within the first NAND device.
2439 - CONFIG_ENV_OFFSET_REDUND
2441 This setting describes a second storage area of CONFIG_ENV_SIZE
2442 size used to hold a redundant copy of the environment data,
2443 so that there is a valid backup copy in case there is a
2444 power failure during a "saveenv" operation.
2446 Note: CONFIG_ENV_OFFSET and CONFIG_ENV_OFFSET_REDUND must be aligned
2447 to a block boundary, and CONFIG_ENV_SIZE must be a multiple of
2448 the NAND devices block size.
2450 - CONFIG_NAND_ENV_DST
2452 Defines address in RAM to which the nand_spl code should copy the
2453 environment. If redundant environment is used, it will be copied to
2454 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE.
2456 - CONFIG_SYS_SPI_INIT_OFFSET
2458 Defines offset to the initial SPI buffer area in DPRAM. The
2459 area is used at an early stage (ROM part) if the environment
2460 is configured to reside in the SPI EEPROM: We need a 520 byte
2461 scratch DPRAM area. It is used between the two initialization
2462 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems
2463 to be a good choice since it makes it far enough from the
2464 start of the data area as well as from the stack pointer.
2466 Please note that the environment is read-only until the monitor
2467 has been relocated to RAM and a RAM copy of the environment has been
2468 created; also, when using EEPROM you will have to use getenv_r()
2469 until then to read environment variables.
2471 The environment is protected by a CRC32 checksum. Before the monitor
2472 is relocated into RAM, as a result of a bad CRC you will be working
2473 with the compiled-in default environment - *silently*!!! [This is
2474 necessary, because the first environment variable we need is the
2475 "baudrate" setting for the console - if we have a bad CRC, we don't
2476 have any device yet where we could complain.]
2478 Note: once the monitor has been relocated, then it will complain if
2479 the default environment is used; a new CRC is computed as soon as you
2480 use the "saveenv" command to store a valid environment.
2482 - CONFIG_SYS_FAULT_ECHO_LINK_DOWN:
2483 Echo the inverted Ethernet link state to the fault LED.
2485 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR
2486 also needs to be defined.
2488 - CONFIG_SYS_FAULT_MII_ADDR:
2489 MII address of the PHY to check for the Ethernet link state.
2491 - CONFIG_SYS_64BIT_VSPRINTF:
2492 Makes vsprintf (and all *printf functions) support printing
2493 of 64bit values by using the L quantifier
2495 - CONFIG_SYS_64BIT_STRTOUL:
2496 Adds simple_strtoull that returns a 64bit value
2498 - CONFIG_NS16550_MIN_FUNCTIONS:
2499 Define this if you desire to only have use of the NS16550_init
2500 and NS16550_putc functions for the serial driver located at
2501 drivers/serial/ns16550.c. This option is useful for saving
2502 space for already greatly restricted images, including but not
2503 limited to NAND_SPL configurations.
2505 Low Level (hardware related) configuration options:
2506 ---------------------------------------------------
2508 - CONFIG_SYS_CACHELINE_SIZE:
2509 Cache Line Size of the CPU.
2511 - CONFIG_SYS_DEFAULT_IMMR:
2512 Default address of the IMMR after system reset.
2514 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU,
2515 and RPXsuper) to be able to adjust the position of
2516 the IMMR register after a reset.
2518 - Floppy Disk Support:
2519 CONFIG_SYS_FDC_DRIVE_NUMBER
2521 the default drive number (default value 0)
2523 CONFIG_SYS_ISA_IO_STRIDE
2525 defines the spacing between FDC chipset registers
2528 CONFIG_SYS_ISA_IO_OFFSET
2530 defines the offset of register from address. It
2531 depends on which part of the data bus is connected to
2532 the FDC chipset. (default value 0)
2534 If CONFIG_SYS_ISA_IO_STRIDE CONFIG_SYS_ISA_IO_OFFSET and
2535 CONFIG_SYS_FDC_DRIVE_NUMBER are undefined, they take their
2538 if CONFIG_SYS_FDC_HW_INIT is defined, then the function
2539 fdc_hw_init() is called at the beginning of the FDC
2540 setup. fdc_hw_init() must be provided by the board
2541 source code. It is used to make hardware dependant
2544 - CONFIG_SYS_IMMR: Physical address of the Internal Memory.
2545 DO NOT CHANGE unless you know exactly what you're
2546 doing! (11-4) [MPC8xx/82xx systems only]
2548 - CONFIG_SYS_INIT_RAM_ADDR:
2550 Start address of memory area that can be used for
2551 initial data and stack; please note that this must be
2552 writable memory that is working WITHOUT special
2553 initialization, i. e. you CANNOT use normal RAM which
2554 will become available only after programming the
2555 memory controller and running certain initialization
2558 U-Boot uses the following memory types:
2559 - MPC8xx and MPC8260: IMMR (internal memory of the CPU)
2560 - MPC824X: data cache
2561 - PPC4xx: data cache
2563 - CONFIG_SYS_GBL_DATA_OFFSET:
2565 Offset of the initial data structure in the memory
2566 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually
2567 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial
2568 data is located at the end of the available space
2569 (sometimes written as (CONFIG_SYS_INIT_RAM_END -
2570 CONFIG_SYS_INIT_DATA_SIZE), and the initial stack is just
2571 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR +
2572 CONFIG_SYS_GBL_DATA_OFFSET) downward.
2575 On the MPC824X (or other systems that use the data
2576 cache for initial memory) the address chosen for
2577 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must
2578 point to an otherwise UNUSED address space between
2579 the top of RAM and the start of the PCI space.
2581 - CONFIG_SYS_SIUMCR: SIU Module Configuration (11-6)
2583 - CONFIG_SYS_SYPCR: System Protection Control (11-9)
2585 - CONFIG_SYS_TBSCR: Time Base Status and Control (11-26)
2587 - CONFIG_SYS_PISCR: Periodic Interrupt Status and Control (11-31)
2589 - CONFIG_SYS_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30)
2591 - CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27)
2593 - CONFIG_SYS_OR_TIMING_SDRAM:
2596 - CONFIG_SYS_MAMR_PTA:
2597 periodic timer for refresh
2599 - CONFIG_SYS_DER: Debug Event Register (37-47)
2601 - FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM,
2602 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP,
2603 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM,
2604 CONFIG_SYS_BR1_PRELIM:
2605 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
2607 - SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
2608 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM,
2609 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM:
2610 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
2612 - CONFIG_SYS_MAMR_PTA, CONFIG_SYS_MPTPR_2BK_4K, CONFIG_SYS_MPTPR_1BK_4K, CONFIG_SYS_MPTPR_2BK_8K,
2613 CONFIG_SYS_MPTPR_1BK_8K, CONFIG_SYS_MAMR_8COL, CONFIG_SYS_MAMR_9COL:
2614 Machine Mode Register and Memory Periodic Timer
2615 Prescaler definitions (SDRAM timing)
2617 - CONFIG_SYS_I2C_UCODE_PATCH, CONFIG_SYS_I2C_DPMEM_OFFSET [0x1FC0]:
2618 enable I2C microcode relocation patch (MPC8xx);
2619 define relocation offset in DPRAM [DSP2]
2621 - CONFIG_SYS_SMC_UCODE_PATCH, CONFIG_SYS_SMC_DPMEM_OFFSET [0x1FC0]:
2622 enable SMC microcode relocation patch (MPC8xx);
2623 define relocation offset in DPRAM [SMC1]
2625 - CONFIG_SYS_SPI_UCODE_PATCH, CONFIG_SYS_SPI_DPMEM_OFFSET [0x1FC0]:
2626 enable SPI microcode relocation patch (MPC8xx);
2627 define relocation offset in DPRAM [SCC4]
2629 - CONFIG_SYS_USE_OSCCLK:
2630 Use OSCM clock mode on MBX8xx board. Be careful,
2631 wrong setting might damage your board. Read
2632 doc/README.MBX before setting this variable!
2634 - CONFIG_SYS_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only)
2635 Offset of the bootmode word in DPRAM used by post
2636 (Power On Self Tests). This definition overrides
2637 #define'd default value in commproc.h resp.
2640 - CONFIG_SYS_PCI_SLV_MEM_LOCAL, CONFIG_SYS_PCI_SLV_MEM_BUS, CONFIG_SYS_PICMR0_MASK_ATTRIB,
2641 CONFIG_SYS_PCI_MSTR0_LOCAL, CONFIG_SYS_PCIMSK0_MASK, CONFIG_SYS_PCI_MSTR1_LOCAL,
2642 CONFIG_SYS_PCIMSK1_MASK, CONFIG_SYS_PCI_MSTR_MEM_LOCAL, CONFIG_SYS_PCI_MSTR_MEM_BUS,
2643 CONFIG_SYS_CPU_PCI_MEM_START, CONFIG_SYS_PCI_MSTR_MEM_SIZE, CONFIG_SYS_POCMR0_MASK_ATTRIB,
2644 CONFIG_SYS_PCI_MSTR_MEMIO_LOCAL, CONFIG_SYS_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START,
2645 CONFIG_SYS_PCI_MSTR_MEMIO_SIZE, CONFIG_SYS_POCMR1_MASK_ATTRIB, CONFIG_SYS_PCI_MSTR_IO_LOCAL,
2646 CONFIG_SYS_PCI_MSTR_IO_BUS, CONFIG_SYS_CPU_PCI_IO_START, CONFIG_SYS_PCI_MSTR_IO_SIZE,
2647 CONFIG_SYS_POCMR2_MASK_ATTRIB: (MPC826x only)
2648 Overrides the default PCI memory map in cpu/mpc8260/pci.c if set.
2650 - CONFIG_PCI_DISABLE_PCIE:
2651 Disable PCI-Express on systems where it is supported but not
2655 Get DDR timing information from an I2C EEPROM. Common
2656 with pluggable memory modules such as SODIMMs
2659 I2C address of the SPD EEPROM
2661 - CONFIG_SYS_SPD_BUS_NUM
2662 If SPD EEPROM is on an I2C bus other than the first
2663 one, specify here. Note that the value must resolve
2664 to something your driver can deal with.
2666 - CONFIG_SYS_83XX_DDR_USES_CS0
2667 Only for 83xx systems. If specified, then DDR should
2668 be configured using CS0 and CS1 instead of CS2 and CS3.
2670 - CONFIG_ETHER_ON_FEC[12]
2671 Define to enable FEC[12] on a 8xx series processor.
2673 - CONFIG_FEC[12]_PHY
2674 Define to the hardcoded PHY address which corresponds
2675 to the given FEC; i. e.
2676 #define CONFIG_FEC1_PHY 4
2677 means that the PHY with address 4 is connected to FEC1
2679 When set to -1, means to probe for first available.
2681 - CONFIG_FEC[12]_PHY_NORXERR
2682 The PHY does not have a RXERR line (RMII only).
2683 (so program the FEC to ignore it).
2686 Enable RMII mode for all FECs.
2687 Note that this is a global option, we can't
2688 have one FEC in standard MII mode and another in RMII mode.
2690 - CONFIG_CRC32_VERIFY
2691 Add a verify option to the crc32 command.
2694 => crc32 -v <address> <count> <crc32>
2696 Where address/count indicate a memory area
2697 and crc32 is the correct crc32 which the
2701 Add the "loopw" memory command. This only takes effect if
2702 the memory commands are activated globally (CONFIG_CMD_MEM).
2705 Add the "mdc" and "mwc" memory commands. These are cyclic
2710 This command will print 4 bytes (10,11,12,13) each 500 ms.
2712 => mwc.l 100 12345678 10
2713 This command will write 12345678 to address 100 all 10 ms.
2715 This only takes effect if the memory commands are activated
2716 globally (CONFIG_CMD_MEM).
2718 - CONFIG_SKIP_LOWLEVEL_INIT
2719 - CONFIG_SKIP_RELOCATE_UBOOT
2721 [ARM only] If these variables are defined, then
2722 certain low level initializations (like setting up
2723 the memory controller) are omitted and/or U-Boot does
2724 not relocate itself into RAM.
2725 Normally these variables MUST NOT be defined. The
2726 only exception is when U-Boot is loaded (to RAM) by
2727 some other boot loader or by a debugger which
2728 performs these initializations itself.
2732 Modifies the behaviour of start.S when compiling a loader
2733 that is executed before the actual U-Boot. E.g. when
2734 compiling a NAND SPL.
2736 Building the Software:
2737 ======================
2739 Building U-Boot has been tested in several native build environments
2740 and in many different cross environments. Of course we cannot support
2741 all possibly existing versions of cross development tools in all
2742 (potentially obsolete) versions. In case of tool chain problems we
2743 recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK)
2744 which is extensively used to build and test U-Boot.
2746 If you are not using a native environment, it is assumed that you
2747 have GNU cross compiling tools available in your path. In this case,
2748 you must set the environment variable CROSS_COMPILE in your shell.
2749 Note that no changes to the Makefile or any other source files are
2750 necessary. For example using the ELDK on a 4xx CPU, please enter:
2752 $ CROSS_COMPILE=ppc_4xx-
2753 $ export CROSS_COMPILE
2755 Note: If you wish to generate Windows versions of the utilities in
2756 the tools directory you can use the MinGW toolchain
2757 (http://www.mingw.org). Set your HOST tools to the MinGW
2758 toolchain and execute 'make tools'. For example:
2760 $ make HOSTCC=i586-mingw32msvc-gcc HOSTSTRIP=i586-mingw32msvc-strip tools
2762 Binaries such as tools/mkimage.exe will be created which can
2763 be executed on computers running Windows.
2765 U-Boot is intended to be simple to build. After installing the
2766 sources you must configure U-Boot for one specific board type. This
2771 where "NAME_config" is the name of one of the existing configu-
2772 rations; see the main Makefile for supported names.
2774 Note: for some board special configuration names may exist; check if
2775 additional information is available from the board vendor; for
2776 instance, the TQM823L systems are available without (standard)
2777 or with LCD support. You can select such additional "features"
2778 when choosing the configuration, i. e.
2781 - will configure for a plain TQM823L, i. e. no LCD support
2783 make TQM823L_LCD_config
2784 - will configure for a TQM823L with U-Boot console on LCD
2789 Finally, type "make all", and you should get some working U-Boot
2790 images ready for download to / installation on your system:
2792 - "u-boot.bin" is a raw binary image
2793 - "u-boot" is an image in ELF binary format
2794 - "u-boot.srec" is in Motorola S-Record format
2796 By default the build is performed locally and the objects are saved
2797 in the source directory. One of the two methods can be used to change
2798 this behavior and build U-Boot to some external directory:
2800 1. Add O= to the make command line invocations:
2802 make O=/tmp/build distclean
2803 make O=/tmp/build NAME_config
2804 make O=/tmp/build all
2806 2. Set environment variable BUILD_DIR to point to the desired location:
2808 export BUILD_DIR=/tmp/build
2813 Note that the command line "O=" setting overrides the BUILD_DIR environment
2817 Please be aware that the Makefiles assume you are using GNU make, so
2818 for instance on NetBSD you might need to use "gmake" instead of
2822 If the system board that you have is not listed, then you will need
2823 to port U-Boot to your hardware platform. To do this, follow these
2826 1. Add a new configuration option for your board to the toplevel
2827 "Makefile" and to the "MAKEALL" script, using the existing
2828 entries as examples. Note that here and at many other places
2829 boards and other names are listed in alphabetical sort order. Please
2831 2. Create a new directory to hold your board specific code. Add any
2832 files you need. In your board directory, you will need at least
2833 the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds".
2834 3. Create a new configuration file "include/configs/<board>.h" for
2836 3. If you're porting U-Boot to a new CPU, then also create a new
2837 directory to hold your CPU specific code. Add any files you need.
2838 4. Run "make <board>_config" with your new name.
2839 5. Type "make", and you should get a working "u-boot.srec" file
2840 to be installed on your target system.
2841 6. Debug and solve any problems that might arise.
2842 [Of course, this last step is much harder than it sounds.]
2845 Testing of U-Boot Modifications, Ports to New Hardware, etc.:
2846 ==============================================================
2848 If you have modified U-Boot sources (for instance added a new board
2849 or support for new devices, a new CPU, etc.) you are expected to
2850 provide feedback to the other developers. The feedback normally takes
2851 the form of a "patch", i. e. a context diff against a certain (latest
2852 official or latest in the git repository) version of U-Boot sources.
2854 But before you submit such a patch, please verify that your modifi-
2855 cation did not break existing code. At least make sure that *ALL* of
2856 the supported boards compile WITHOUT ANY compiler warnings. To do so,
2857 just run the "MAKEALL" script, which will configure and build U-Boot
2858 for ALL supported system. Be warned, this will take a while. You can
2859 select which (cross) compiler to use by passing a `CROSS_COMPILE'
2860 environment variable to the script, i. e. to use the ELDK cross tools
2863 CROSS_COMPILE=ppc_8xx- MAKEALL
2865 or to build on a native PowerPC system you can type
2867 CROSS_COMPILE=' ' MAKEALL
2869 When using the MAKEALL script, the default behaviour is to build
2870 U-Boot in the source directory. This location can be changed by
2871 setting the BUILD_DIR environment variable. Also, for each target
2872 built, the MAKEALL script saves two log files (<target>.ERR and
2873 <target>.MAKEALL) in the <source dir>/LOG directory. This default
2874 location can be changed by setting the MAKEALL_LOGDIR environment
2875 variable. For example:
2877 export BUILD_DIR=/tmp/build
2878 export MAKEALL_LOGDIR=/tmp/log
2879 CROSS_COMPILE=ppc_8xx- MAKEALL
2881 With the above settings build objects are saved in the /tmp/build,
2882 log files are saved in the /tmp/log and the source tree remains clean
2883 during the whole build process.
2886 See also "U-Boot Porting Guide" below.
2889 Monitor Commands - Overview:
2890 ============================
2892 go - start application at address 'addr'
2893 run - run commands in an environment variable
2894 bootm - boot application image from memory
2895 bootp - boot image via network using BootP/TFTP protocol
2896 tftpboot- boot image via network using TFTP protocol
2897 and env variables "ipaddr" and "serverip"
2898 (and eventually "gatewayip")
2899 rarpboot- boot image via network using RARP/TFTP protocol
2900 diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
2901 loads - load S-Record file over serial line
2902 loadb - load binary file over serial line (kermit mode)
2904 mm - memory modify (auto-incrementing)
2905 nm - memory modify (constant address)
2906 mw - memory write (fill)
2908 cmp - memory compare
2909 crc32 - checksum calculation
2910 i2c - I2C sub-system
2911 sspi - SPI utility commands
2912 base - print or set address offset
2913 printenv- print environment variables
2914 setenv - set environment variables
2915 saveenv - save environment variables to persistent storage
2916 protect - enable or disable FLASH write protection
2917 erase - erase FLASH memory
2918 flinfo - print FLASH memory information
2919 bdinfo - print Board Info structure
2920 iminfo - print header information for application image
2921 coninfo - print console devices and informations
2922 ide - IDE sub-system
2923 loop - infinite loop on address range
2924 loopw - infinite write loop on address range
2925 mtest - simple RAM test
2926 icache - enable or disable instruction cache
2927 dcache - enable or disable data cache
2928 reset - Perform RESET of the CPU
2929 echo - echo args to console
2930 version - print monitor version
2931 help - print online help
2932 ? - alias for 'help'
2935 Monitor Commands - Detailed Description:
2936 ========================================
2940 For now: just type "help <command>".
2943 Environment Variables:
2944 ======================
2946 U-Boot supports user configuration using Environment Variables which
2947 can be made persistent by saving to Flash memory.
2949 Environment Variables are set using "setenv", printed using
2950 "printenv", and saved to Flash using "saveenv". Using "setenv"
2951 without a value can be used to delete a variable from the
2952 environment. As long as you don't save the environment you are
2953 working with an in-memory copy. In case the Flash area containing the
2954 environment is erased by accident, a default environment is provided.
2956 Some configuration options can be set using Environment Variables:
2958 baudrate - see CONFIG_BAUDRATE
2960 bootdelay - see CONFIG_BOOTDELAY
2962 bootcmd - see CONFIG_BOOTCOMMAND
2964 bootargs - Boot arguments when booting an RTOS image
2966 bootfile - Name of the image to load with TFTP
2968 bootm_low - Memory range available for image processing in the bootm
2969 command can be restricted. This variable is given as
2970 a hexadecimal number and defines lowest address allowed
2971 for use by the bootm command. See also "bootm_size"
2972 environment variable. Address defined by "bootm_low" is
2973 also the base of the initial memory mapping for the Linux
2974 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ.
2976 bootm_size - Memory range available for image processing in the bootm
2977 command can be restricted. This variable is given as
2978 a hexadecimal number and defines the size of the region
2979 allowed for use by the bootm command. See also "bootm_low"
2980 environment variable.
2982 updatefile - Location of the software update file on a TFTP server, used
2983 by the automatic software update feature. Please refer to
2984 documentation in doc/README.update for more details.
2986 autoload - if set to "no" (any string beginning with 'n'),
2987 "bootp" will just load perform a lookup of the
2988 configuration from the BOOTP server, but not try to
2989 load any image using TFTP
2991 autoscript - if set to "yes" commands like "loadb", "loady",
2992 "bootp", "tftpb", "rarpboot" and "nfs" will attempt
2993 to automatically run script images (by internally
2996 autoscript_uname - if script image is in a format (FIT) this
2997 variable is used to get script subimage unit name.
2999 autostart - if set to "yes", an image loaded using the "bootp",
3000 "rarpboot", "tftpboot" or "diskboot" commands will
3001 be automatically started (by internally calling
3004 If set to "no", a standalone image passed to the
3005 "bootm" command will be copied to the load address
3006 (and eventually uncompressed), but NOT be started.
3007 This can be used to load and uncompress arbitrary
3010 i2cfast - (PPC405GP|PPC405EP only)
3011 if set to 'y' configures Linux I2C driver for fast
3012 mode (400kHZ). This environment variable is used in
3013 initialization code. So, for changes to be effective
3014 it must be saved and board must be reset.
3016 initrd_high - restrict positioning of initrd images:
3017 If this variable is not set, initrd images will be
3018 copied to the highest possible address in RAM; this
3019 is usually what you want since it allows for
3020 maximum initrd size. If for some reason you want to
3021 make sure that the initrd image is loaded below the
3022 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment
3023 variable to a value of "no" or "off" or "0".
3024 Alternatively, you can set it to a maximum upper
3025 address to use (U-Boot will still check that it
3026 does not overwrite the U-Boot stack and data).
3028 For instance, when you have a system with 16 MB
3029 RAM, and want to reserve 4 MB from use by Linux,
3030 you can do this by adding "mem=12M" to the value of
3031 the "bootargs" variable. However, now you must make
3032 sure that the initrd image is placed in the first
3033 12 MB as well - this can be done with
3035 setenv initrd_high 00c00000
3037 If you set initrd_high to 0xFFFFFFFF, this is an
3038 indication to U-Boot that all addresses are legal
3039 for the Linux kernel, including addresses in flash
3040 memory. In this case U-Boot will NOT COPY the
3041 ramdisk at all. This may be useful to reduce the
3042 boot time on your system, but requires that this
3043 feature is supported by your Linux kernel.
3045 ipaddr - IP address; needed for tftpboot command
3047 loadaddr - Default load address for commands like "bootp",
3048 "rarpboot", "tftpboot", "loadb" or "diskboot"
3050 loads_echo - see CONFIG_LOADS_ECHO
3052 serverip - TFTP server IP address; needed for tftpboot command
3054 bootretry - see CONFIG_BOOT_RETRY_TIME
3056 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
3058 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
3060 ethprime - When CONFIG_NET_MULTI is enabled controls which
3061 interface is used first.
3063 ethact - When CONFIG_NET_MULTI is enabled controls which
3064 interface is currently active. For example you
3065 can do the following
3067 => setenv ethact FEC ETHERNET
3068 => ping 192.168.0.1 # traffic sent on FEC ETHERNET
3069 => setenv ethact SCC ETHERNET
3070 => ping 10.0.0.1 # traffic sent on SCC ETHERNET
3072 ethrotate - When set to "no" U-Boot does not go through all
3073 available network interfaces.
3074 It just stays at the currently selected interface.
3076 netretry - When set to "no" each network operation will
3077 either succeed or fail without retrying.
3078 When set to "once" the network operation will
3079 fail when all the available network interfaces
3080 are tried once without success.
3081 Useful on scripts which control the retry operation
3084 npe_ucode - set load address for the NPE microcode
3086 tftpsrcport - If this is set, the value is used for TFTP's
3089 tftpdstport - If this is set, the value is used for TFTP's UDP
3090 destination port instead of the Well Know Port 69.
3092 vlan - When set to a value < 4095 the traffic over
3093 Ethernet is encapsulated/received over 802.1q
3096 The following environment variables may be used and automatically
3097 updated by the network boot commands ("bootp" and "rarpboot"),
3098 depending the information provided by your boot server:
3100 bootfile - see above
3101 dnsip - IP address of your Domain Name Server
3102 dnsip2 - IP address of your secondary Domain Name Server
3103 gatewayip - IP address of the Gateway (Router) to use
3104 hostname - Target hostname
3106 netmask - Subnet Mask
3107 rootpath - Pathname of the root filesystem on the NFS server
3108 serverip - see above
3111 There are two special Environment Variables:
3113 serial# - contains hardware identification information such
3114 as type string and/or serial number
3115 ethaddr - Ethernet address
3117 These variables can be set only once (usually during manufacturing of
3118 the board). U-Boot refuses to delete or overwrite these variables
3119 once they have been set once.
3122 Further special Environment Variables:
3124 ver - Contains the U-Boot version string as printed
3125 with the "version" command. This variable is
3126 readonly (see CONFIG_VERSION_VARIABLE).
3129 Please note that changes to some configuration parameters may take
3130 only effect after the next boot (yes, that's just like Windoze :-).
3133 Command Line Parsing:
3134 =====================
3136 There are two different command line parsers available with U-Boot:
3137 the old "simple" one, and the much more powerful "hush" shell:
3139 Old, simple command line parser:
3140 --------------------------------
3142 - supports environment variables (through setenv / saveenv commands)
3143 - several commands on one line, separated by ';'
3144 - variable substitution using "... ${name} ..." syntax
3145 - special characters ('$', ';') can be escaped by prefixing with '\',
3147 setenv bootcmd bootm \${address}
3148 - You can also escape text by enclosing in single apostrophes, for example:
3149 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
3154 - similar to Bourne shell, with control structures like
3155 if...then...else...fi, for...do...done; while...do...done,
3156 until...do...done, ...
3157 - supports environment ("global") variables (through setenv / saveenv
3158 commands) and local shell variables (through standard shell syntax
3159 "name=value"); only environment variables can be used with "run"
3165 (1) If a command line (or an environment variable executed by a "run"
3166 command) contains several commands separated by semicolon, and
3167 one of these commands fails, then the remaining commands will be
3170 (2) If you execute several variables with one call to run (i. e.
3171 calling run with a list of variables as arguments), any failing
3172 command will cause "run" to terminate, i. e. the remaining
3173 variables are not executed.
3175 Note for Redundant Ethernet Interfaces:
3176 =======================================
3178 Some boards come with redundant Ethernet interfaces; U-Boot supports
3179 such configurations and is capable of automatic selection of a
3180 "working" interface when needed. MAC assignment works as follows:
3182 Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
3183 MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
3184 "eth1addr" (=>eth1), "eth2addr", ...
3186 If the network interface stores some valid MAC address (for instance
3187 in SROM), this is used as default address if there is NO correspon-
3188 ding setting in the environment; if the corresponding environment
3189 variable is set, this overrides the settings in the card; that means:
3191 o If the SROM has a valid MAC address, and there is no address in the
3192 environment, the SROM's address is used.
3194 o If there is no valid address in the SROM, and a definition in the
3195 environment exists, then the value from the environment variable is
3198 o If both the SROM and the environment contain a MAC address, and
3199 both addresses are the same, this MAC address is used.
3201 o If both the SROM and the environment contain a MAC address, and the
3202 addresses differ, the value from the environment is used and a
3205 o If neither SROM nor the environment contain a MAC address, an error
3212 U-Boot is capable of booting (and performing other auxiliary operations on)
3213 images in two formats:
3215 New uImage format (FIT)
3216 -----------------------
3218 Flexible and powerful format based on Flattened Image Tree -- FIT (similar
3219 to Flattened Device Tree). It allows the use of images with multiple
3220 components (several kernels, ramdisks, etc.), with contents protected by
3221 SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory.
3227 Old image format is based on binary files which can be basically anything,
3228 preceded by a special header; see the definitions in include/image.h for
3229 details; basically, the header defines the following image properties:
3231 * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
3232 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
3233 LynxOS, pSOS, QNX, RTEMS, INTEGRITY;
3234 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS,
3236 * Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86,
3237 IA64, MIPS, NIOS, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
3238 Currently supported: ARM, AVR32, Intel x86, MIPS, NIOS, PowerPC).
3239 * Compression Type (uncompressed, gzip, bzip2)
3245 The header is marked by a special Magic Number, and both the header
3246 and the data portions of the image are secured against corruption by
3253 Although U-Boot should support any OS or standalone application
3254 easily, the main focus has always been on Linux during the design of
3257 U-Boot includes many features that so far have been part of some
3258 special "boot loader" code within the Linux kernel. Also, any
3259 "initrd" images to be used are no longer part of one big Linux image;
3260 instead, kernel and "initrd" are separate images. This implementation
3261 serves several purposes:
3263 - the same features can be used for other OS or standalone
3264 applications (for instance: using compressed images to reduce the
3265 Flash memory footprint)
3267 - it becomes much easier to port new Linux kernel versions because
3268 lots of low-level, hardware dependent stuff are done by U-Boot
3270 - the same Linux kernel image can now be used with different "initrd"
3271 images; of course this also means that different kernel images can
3272 be run with the same "initrd". This makes testing easier (you don't
3273 have to build a new "zImage.initrd" Linux image when you just
3274 change a file in your "initrd"). Also, a field-upgrade of the
3275 software is easier now.
3281 Porting Linux to U-Boot based systems:
3282 ---------------------------------------
3284 U-Boot cannot save you from doing all the necessary modifications to
3285 configure the Linux device drivers for use with your target hardware
3286 (no, we don't intend to provide a full virtual machine interface to
3289 But now you can ignore ALL boot loader code (in arch/ppc/mbxboot).
3291 Just make sure your machine specific header file (for instance
3292 include/asm-ppc/tqm8xx.h) includes the same definition of the Board
3293 Information structure as we define in include/asm-<arch>/u-boot.h,
3294 and make sure that your definition of IMAP_ADDR uses the same value
3295 as your U-Boot configuration in CONFIG_SYS_IMMR.
3298 Configuring the Linux kernel:
3299 -----------------------------
3301 No specific requirements for U-Boot. Make sure you have some root
3302 device (initial ramdisk, NFS) for your target system.
3305 Building a Linux Image:
3306 -----------------------
3308 With U-Boot, "normal" build targets like "zImage" or "bzImage" are
3309 not used. If you use recent kernel source, a new build target
3310 "uImage" will exist which automatically builds an image usable by
3311 U-Boot. Most older kernels also have support for a "pImage" target,
3312 which was introduced for our predecessor project PPCBoot and uses a
3313 100% compatible format.
3322 The "uImage" build target uses a special tool (in 'tools/mkimage') to
3323 encapsulate a compressed Linux kernel image with header information,
3324 CRC32 checksum etc. for use with U-Boot. This is what we are doing:
3326 * build a standard "vmlinux" kernel image (in ELF binary format):
3328 * convert the kernel into a raw binary image:
3330 ${CROSS_COMPILE}-objcopy -O binary \
3331 -R .note -R .comment \
3332 -S vmlinux linux.bin
3334 * compress the binary image:
3338 * package compressed binary image for U-Boot:
3340 mkimage -A ppc -O linux -T kernel -C gzip \
3341 -a 0 -e 0 -n "Linux Kernel Image" \
3342 -d linux.bin.gz uImage
3345 The "mkimage" tool can also be used to create ramdisk images for use
3346 with U-Boot, either separated from the Linux kernel image, or
3347 combined into one file. "mkimage" encapsulates the images with a 64
3348 byte header containing information about target architecture,
3349 operating system, image type, compression method, entry points, time
3350 stamp, CRC32 checksums, etc.
3352 "mkimage" can be called in two ways: to verify existing images and
3353 print the header information, or to build new images.
3355 In the first form (with "-l" option) mkimage lists the information
3356 contained in the header of an existing U-Boot image; this includes
3357 checksum verification:
3359 tools/mkimage -l image
3360 -l ==> list image header information
3362 The second form (with "-d" option) is used to build a U-Boot image
3363 from a "data file" which is used as image payload:
3365 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
3366 -n name -d data_file image
3367 -A ==> set architecture to 'arch'
3368 -O ==> set operating system to 'os'
3369 -T ==> set image type to 'type'
3370 -C ==> set compression type 'comp'
3371 -a ==> set load address to 'addr' (hex)
3372 -e ==> set entry point to 'ep' (hex)
3373 -n ==> set image name to 'name'
3374 -d ==> use image data from 'datafile'
3376 Right now, all Linux kernels for PowerPC systems use the same load
3377 address (0x00000000), but the entry point address depends on the
3380 - 2.2.x kernels have the entry point at 0x0000000C,
3381 - 2.3.x and later kernels have the entry point at 0x00000000.
3383 So a typical call to build a U-Boot image would read:
3385 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
3386 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
3387 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux.gz \
3388 > examples/uImage.TQM850L
3389 Image Name: 2.4.4 kernel for TQM850L
3390 Created: Wed Jul 19 02:34:59 2000
3391 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3392 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
3393 Load Address: 0x00000000
3394 Entry Point: 0x00000000
3396 To verify the contents of the image (or check for corruption):
3398 -> tools/mkimage -l examples/uImage.TQM850L
3399 Image Name: 2.4.4 kernel for TQM850L
3400 Created: Wed Jul 19 02:34:59 2000
3401 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3402 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
3403 Load Address: 0x00000000
3404 Entry Point: 0x00000000
3406 NOTE: for embedded systems where boot time is critical you can trade
3407 speed for memory and install an UNCOMPRESSED image instead: this
3408 needs more space in Flash, but boots much faster since it does not
3409 need to be uncompressed:
3411 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux.gz
3412 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
3413 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
3414 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux \
3415 > examples/uImage.TQM850L-uncompressed
3416 Image Name: 2.4.4 kernel for TQM850L
3417 Created: Wed Jul 19 02:34:59 2000
3418 Image Type: PowerPC Linux Kernel Image (uncompressed)
3419 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
3420 Load Address: 0x00000000
3421 Entry Point: 0x00000000
3424 Similar you can build U-Boot images from a 'ramdisk.image.gz' file
3425 when your kernel is intended to use an initial ramdisk:
3427 -> tools/mkimage -n 'Simple Ramdisk Image' \
3428 > -A ppc -O linux -T ramdisk -C gzip \
3429 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
3430 Image Name: Simple Ramdisk Image
3431 Created: Wed Jan 12 14:01:50 2000
3432 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
3433 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
3434 Load Address: 0x00000000
3435 Entry Point: 0x00000000
3438 Installing a Linux Image:
3439 -------------------------
3441 To downloading a U-Boot image over the serial (console) interface,
3442 you must convert the image to S-Record format:
3444 objcopy -I binary -O srec examples/image examples/image.srec
3446 The 'objcopy' does not understand the information in the U-Boot
3447 image header, so the resulting S-Record file will be relative to
3448 address 0x00000000. To load it to a given address, you need to
3449 specify the target address as 'offset' parameter with the 'loads'
3452 Example: install the image to address 0x40100000 (which on the
3453 TQM8xxL is in the first Flash bank):
3455 => erase 40100000 401FFFFF
3461 ## Ready for S-Record download ...
3462 ~>examples/image.srec
3463 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
3465 15989 15990 15991 15992
3466 [file transfer complete]
3468 ## Start Addr = 0x00000000
3471 You can check the success of the download using the 'iminfo' command;
3472 this includes a checksum verification so you can be sure no data
3473 corruption happened:
3477 ## Checking Image at 40100000 ...
3478 Image Name: 2.2.13 for initrd on TQM850L
3479 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3480 Data Size: 335725 Bytes = 327 kB = 0 MB
3481 Load Address: 00000000
3482 Entry Point: 0000000c
3483 Verifying Checksum ... OK
3489 The "bootm" command is used to boot an application that is stored in
3490 memory (RAM or Flash). In case of a Linux kernel image, the contents
3491 of the "bootargs" environment variable is passed to the kernel as
3492 parameters. You can check and modify this variable using the
3493 "printenv" and "setenv" commands:
3496 => printenv bootargs
3497 bootargs=root=/dev/ram
3499 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
3501 => printenv bootargs
3502 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
3505 ## Booting Linux kernel at 40020000 ...
3506 Image Name: 2.2.13 for NFS on TQM850L
3507 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3508 Data Size: 381681 Bytes = 372 kB = 0 MB
3509 Load Address: 00000000
3510 Entry Point: 0000000c
3511 Verifying Checksum ... OK
3512 Uncompressing Kernel Image ... OK
3513 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
3514 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
3515 time_init: decrementer frequency = 187500000/60
3516 Calibrating delay loop... 49.77 BogoMIPS
3517 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
3520 If you want to boot a Linux kernel with initial RAM disk, you pass
3521 the memory addresses of both the kernel and the initrd image (PPBCOOT
3522 format!) to the "bootm" command:
3524 => imi 40100000 40200000
3526 ## Checking Image at 40100000 ...
3527 Image Name: 2.2.13 for initrd on TQM850L
3528 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3529 Data Size: 335725 Bytes = 327 kB = 0 MB
3530 Load Address: 00000000
3531 Entry Point: 0000000c
3532 Verifying Checksum ... OK
3534 ## Checking Image at 40200000 ...
3535 Image Name: Simple Ramdisk Image
3536 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
3537 Data Size: 566530 Bytes = 553 kB = 0 MB
3538 Load Address: 00000000
3539 Entry Point: 00000000
3540 Verifying Checksum ... OK
3542 => bootm 40100000 40200000
3543 ## Booting Linux kernel at 40100000 ...
3544 Image Name: 2.2.13 for initrd on TQM850L
3545 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3546 Data Size: 335725 Bytes = 327 kB = 0 MB
3547 Load Address: 00000000
3548 Entry Point: 0000000c
3549 Verifying Checksum ... OK
3550 Uncompressing Kernel Image ... OK
3551 ## Loading RAMDisk Image at 40200000 ...
3552 Image Name: Simple Ramdisk Image
3553 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
3554 Data Size: 566530 Bytes = 553 kB = 0 MB
3555 Load Address: 00000000
3556 Entry Point: 00000000
3557 Verifying Checksum ... OK
3558 Loading Ramdisk ... OK
3559 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
3560 Boot arguments: root=/dev/ram
3561 time_init: decrementer frequency = 187500000/60
3562 Calibrating delay loop... 49.77 BogoMIPS
3564 RAMDISK: Compressed image found at block 0
3565 VFS: Mounted root (ext2 filesystem).
3569 Boot Linux and pass a flat device tree:
3572 First, U-Boot must be compiled with the appropriate defines. See the section
3573 titled "Linux Kernel Interface" above for a more in depth explanation. The
3574 following is an example of how to start a kernel and pass an updated
3580 oft=oftrees/mpc8540ads.dtb
3581 => tftp $oftaddr $oft
3582 Speed: 1000, full duplex
3584 TFTP from server 192.168.1.1; our IP address is 192.168.1.101
3585 Filename 'oftrees/mpc8540ads.dtb'.
3586 Load address: 0x300000
3589 Bytes transferred = 4106 (100a hex)
3590 => tftp $loadaddr $bootfile
3591 Speed: 1000, full duplex
3593 TFTP from server 192.168.1.1; our IP address is 192.168.1.2
3595 Load address: 0x200000
3596 Loading:############
3598 Bytes transferred = 1029407 (fb51f hex)
3603 => bootm $loadaddr - $oftaddr
3604 ## Booting image at 00200000 ...
3605 Image Name: Linux-2.6.17-dirty
3606 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3607 Data Size: 1029343 Bytes = 1005.2 kB
3608 Load Address: 00000000
3609 Entry Point: 00000000
3610 Verifying Checksum ... OK
3611 Uncompressing Kernel Image ... OK
3612 Booting using flat device tree at 0x300000
3613 Using MPC85xx ADS machine description
3614 Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb
3618 More About U-Boot Image Types:
3619 ------------------------------
3621 U-Boot supports the following image types:
3623 "Standalone Programs" are directly runnable in the environment
3624 provided by U-Boot; it is expected that (if they behave
3625 well) you can continue to work in U-Boot after return from
3626 the Standalone Program.
3627 "OS Kernel Images" are usually images of some Embedded OS which
3628 will take over control completely. Usually these programs
3629 will install their own set of exception handlers, device
3630 drivers, set up the MMU, etc. - this means, that you cannot
3631 expect to re-enter U-Boot except by resetting the CPU.
3632 "RAMDisk Images" are more or less just data blocks, and their
3633 parameters (address, size) are passed to an OS kernel that is
3635 "Multi-File Images" contain several images, typically an OS
3636 (Linux) kernel image and one or more data images like
3637 RAMDisks. This construct is useful for instance when you want
3638 to boot over the network using BOOTP etc., where the boot
3639 server provides just a single image file, but you want to get
3640 for instance an OS kernel and a RAMDisk image.
3642 "Multi-File Images" start with a list of image sizes, each
3643 image size (in bytes) specified by an "uint32_t" in network
3644 byte order. This list is terminated by an "(uint32_t)0".
3645 Immediately after the terminating 0 follow the images, one by
3646 one, all aligned on "uint32_t" boundaries (size rounded up to
3647 a multiple of 4 bytes).
3649 "Firmware Images" are binary images containing firmware (like
3650 U-Boot or FPGA images) which usually will be programmed to
3653 "Script files" are command sequences that will be executed by
3654 U-Boot's command interpreter; this feature is especially
3655 useful when you configure U-Boot to use a real shell (hush)
3656 as command interpreter.
3662 One of the features of U-Boot is that you can dynamically load and
3663 run "standalone" applications, which can use some resources of
3664 U-Boot like console I/O functions or interrupt services.
3666 Two simple examples are included with the sources:
3671 'examples/hello_world.c' contains a small "Hello World" Demo
3672 application; it is automatically compiled when you build U-Boot.
3673 It's configured to run at address 0x00040004, so you can play with it
3677 ## Ready for S-Record download ...
3678 ~>examples/hello_world.srec
3679 1 2 3 4 5 6 7 8 9 10 11 ...
3680 [file transfer complete]
3682 ## Start Addr = 0x00040004
3684 => go 40004 Hello World! This is a test.
3685 ## Starting application at 0x00040004 ...
3696 Hit any key to exit ...
3698 ## Application terminated, rc = 0x0
3700 Another example, which demonstrates how to register a CPM interrupt
3701 handler with the U-Boot code, can be found in 'examples/timer.c'.
3702 Here, a CPM timer is set up to generate an interrupt every second.
3703 The interrupt service routine is trivial, just printing a '.'
3704 character, but this is just a demo program. The application can be
3705 controlled by the following keys:
3707 ? - print current values og the CPM Timer registers
3708 b - enable interrupts and start timer
3709 e - stop timer and disable interrupts
3710 q - quit application
3713 ## Ready for S-Record download ...
3714 ~>examples/timer.srec
3715 1 2 3 4 5 6 7 8 9 10 11 ...
3716 [file transfer complete]
3718 ## Start Addr = 0x00040004
3721 ## Starting application at 0x00040004 ...
3724 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
3727 [q, b, e, ?] Set interval 1000000 us
3730 [q, b, e, ?] ........
3731 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
3734 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
3737 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
3740 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
3742 [q, b, e, ?] ...Stopping timer
3744 [q, b, e, ?] ## Application terminated, rc = 0x0
3750 Over time, many people have reported problems when trying to use the
3751 "minicom" terminal emulation program for serial download. I (wd)
3752 consider minicom to be broken, and recommend not to use it. Under
3753 Unix, I recommend to use C-Kermit for general purpose use (and
3754 especially for kermit binary protocol download ("loadb" command), and
3755 use "cu" for S-Record download ("loads" command).
3757 Nevertheless, if you absolutely want to use it try adding this
3758 configuration to your "File transfer protocols" section:
3760 Name Program Name U/D FullScr IO-Red. Multi
3761 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
3762 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
3768 Starting at version 0.9.2, U-Boot supports NetBSD both as host
3769 (build U-Boot) and target system (boots NetBSD/mpc8xx).
3771 Building requires a cross environment; it is known to work on
3772 NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
3773 need gmake since the Makefiles are not compatible with BSD make).
3774 Note that the cross-powerpc package does not install include files;
3775 attempting to build U-Boot will fail because <machine/ansi.h> is
3776 missing. This file has to be installed and patched manually:
3778 # cd /usr/pkg/cross/powerpc-netbsd/include
3780 # ln -s powerpc machine
3781 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
3782 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
3784 Native builds *don't* work due to incompatibilities between native
3785 and U-Boot include files.
3787 Booting assumes that (the first part of) the image booted is a
3788 stage-2 loader which in turn loads and then invokes the kernel
3789 proper. Loader sources will eventually appear in the NetBSD source
3790 tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
3791 meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz
3794 Implementation Internals:
3795 =========================
3797 The following is not intended to be a complete description of every
3798 implementation detail. However, it should help to understand the
3799 inner workings of U-Boot and make it easier to port it to custom
3803 Initial Stack, Global Data:
3804 ---------------------------
3806 The implementation of U-Boot is complicated by the fact that U-Boot
3807 starts running out of ROM (flash memory), usually without access to
3808 system RAM (because the memory controller is not initialized yet).
3809 This means that we don't have writable Data or BSS segments, and BSS
3810 is not initialized as zero. To be able to get a C environment working
3811 at all, we have to allocate at least a minimal stack. Implementation
3812 options for this are defined and restricted by the CPU used: Some CPU
3813 models provide on-chip memory (like the IMMR area on MPC8xx and
3814 MPC826x processors), on others (parts of) the data cache can be
3815 locked as (mis-) used as memory, etc.
3817 Chris Hallinan posted a good summary of these issues to the
3818 U-Boot mailing list:
3820 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
3821 From: "Chris Hallinan" <clh@net1plus.com>
3822 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
3825 Correct me if I'm wrong, folks, but the way I understand it
3826 is this: Using DCACHE as initial RAM for Stack, etc, does not
3827 require any physical RAM backing up the cache. The cleverness
3828 is that the cache is being used as a temporary supply of
3829 necessary storage before the SDRAM controller is setup. It's
3830 beyond the scope of this list to explain the details, but you
3831 can see how this works by studying the cache architecture and
3832 operation in the architecture and processor-specific manuals.
3834 OCM is On Chip Memory, which I believe the 405GP has 4K. It
3835 is another option for the system designer to use as an
3836 initial stack/RAM area prior to SDRAM being available. Either
3837 option should work for you. Using CS 4 should be fine if your
3838 board designers haven't used it for something that would
3839 cause you grief during the initial boot! It is frequently not
3842 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere
3843 with your processor/board/system design. The default value
3844 you will find in any recent u-boot distribution in
3845 walnut.h should work for you. I'd set it to a value larger
3846 than your SDRAM module. If you have a 64MB SDRAM module, set
3847 it above 400_0000. Just make sure your board has no resources
3848 that are supposed to respond to that address! That code in
3849 start.S has been around a while and should work as is when
3850 you get the config right.
3855 It is essential to remember this, since it has some impact on the C
3856 code for the initialization procedures:
3858 * Initialized global data (data segment) is read-only. Do not attempt
3861 * Do not use any uninitialized global data (or implicitely initialized
3862 as zero data - BSS segment) at all - this is undefined, initiali-
3863 zation is performed later (when relocating to RAM).
3865 * Stack space is very limited. Avoid big data buffers or things like
3868 Having only the stack as writable memory limits means we cannot use
3869 normal global data to share information beween the code. But it
3870 turned out that the implementation of U-Boot can be greatly
3871 simplified by making a global data structure (gd_t) available to all
3872 functions. We could pass a pointer to this data as argument to _all_
3873 functions, but this would bloat the code. Instead we use a feature of
3874 the GCC compiler (Global Register Variables) to share the data: we
3875 place a pointer (gd) to the global data into a register which we
3876 reserve for this purpose.
3878 When choosing a register for such a purpose we are restricted by the
3879 relevant (E)ABI specifications for the current architecture, and by
3880 GCC's implementation.
3882 For PowerPC, the following registers have specific use:
3884 R2: reserved for system use
3885 R3-R4: parameter passing and return values
3886 R5-R10: parameter passing
3887 R13: small data area pointer
3891 (U-Boot also uses R14 as internal GOT pointer.)
3893 ==> U-Boot will use R2 to hold a pointer to the global data
3895 Note: on PPC, we could use a static initializer (since the
3896 address of the global data structure is known at compile time),
3897 but it turned out that reserving a register results in somewhat
3898 smaller code - although the code savings are not that big (on
3899 average for all boards 752 bytes for the whole U-Boot image,
3900 624 text + 127 data).
3902 On Blackfin, the normal C ABI (except for P5) is followed as documented here:
3903 http://docs.blackfin.uclinux.org/doku.php?id=application_binary_interface
3905 ==> U-Boot will use P5 to hold a pointer to the global data
3907 On ARM, the following registers are used:
3909 R0: function argument word/integer result
3910 R1-R3: function argument word
3912 R10: stack limit (used only if stack checking if enabled)
3913 R11: argument (frame) pointer
3914 R12: temporary workspace
3917 R15: program counter
3919 ==> U-Boot will use R8 to hold a pointer to the global data
3921 NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope,
3922 or current versions of GCC may "optimize" the code too much.
3927 U-Boot runs in system state and uses physical addresses, i.e. the
3928 MMU is not used either for address mapping nor for memory protection.
3930 The available memory is mapped to fixed addresses using the memory
3931 controller. In this process, a contiguous block is formed for each
3932 memory type (Flash, SDRAM, SRAM), even when it consists of several
3933 physical memory banks.
3935 U-Boot is installed in the first 128 kB of the first Flash bank (on
3936 TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
3937 booting and sizing and initializing DRAM, the code relocates itself
3938 to the upper end of DRAM. Immediately below the U-Boot code some
3939 memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN
3940 configuration setting]. Below that, a structure with global Board
3941 Info data is placed, followed by the stack (growing downward).
3943 Additionally, some exception handler code is copied to the low 8 kB
3944 of DRAM (0x00000000 ... 0x00001FFF).
3946 So a typical memory configuration with 16 MB of DRAM could look like
3949 0x0000 0000 Exception Vector code
3952 0x0000 2000 Free for Application Use
3958 0x00FB FF20 Monitor Stack (Growing downward)
3959 0x00FB FFAC Board Info Data and permanent copy of global data
3960 0x00FC 0000 Malloc Arena
3963 0x00FE 0000 RAM Copy of Monitor Code
3964 ... eventually: LCD or video framebuffer
3965 ... eventually: pRAM (Protected RAM - unchanged by reset)
3966 0x00FF FFFF [End of RAM]
3969 System Initialization:
3970 ----------------------
3972 In the reset configuration, U-Boot starts at the reset entry point
3973 (on most PowerPC systems at address 0x00000100). Because of the reset
3974 configuration for CS0# this is a mirror of the onboard Flash memory.
3975 To be able to re-map memory U-Boot then jumps to its link address.
3976 To be able to implement the initialization code in C, a (small!)
3977 initial stack is set up in the internal Dual Ported RAM (in case CPUs
3978 which provide such a feature like MPC8xx or MPC8260), or in a locked
3979 part of the data cache. After that, U-Boot initializes the CPU core,
3980 the caches and the SIU.
3982 Next, all (potentially) available memory banks are mapped using a
3983 preliminary mapping. For example, we put them on 512 MB boundaries
3984 (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
3985 on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
3986 programmed for SDRAM access. Using the temporary configuration, a
3987 simple memory test is run that determines the size of the SDRAM
3990 When there is more than one SDRAM bank, and the banks are of
3991 different size, the largest is mapped first. For equal size, the first
3992 bank (CS2#) is mapped first. The first mapping is always for address
3993 0x00000000, with any additional banks following immediately to create
3994 contiguous memory starting from 0.
3996 Then, the monitor installs itself at the upper end of the SDRAM area
3997 and allocates memory for use by malloc() and for the global Board
3998 Info data; also, the exception vector code is copied to the low RAM
3999 pages, and the final stack is set up.
4001 Only after this relocation will you have a "normal" C environment;
4002 until that you are restricted in several ways, mostly because you are
4003 running from ROM, and because the code will have to be relocated to a
4007 U-Boot Porting Guide:
4008 ----------------------
4010 [Based on messages by Jerry Van Baren in the U-Boot-Users mailing
4014 int main(int argc, char *argv[])
4016 sighandler_t no_more_time;
4018 signal(SIGALRM, no_more_time);
4019 alarm(PROJECT_DEADLINE - toSec (3 * WEEK));
4021 if (available_money > available_manpower) {
4022 Pay consultant to port U-Boot;
4026 Download latest U-Boot source;
4028 Subscribe to u-boot mailing list;
4031 email("Hi, I am new to U-Boot, how do I get started?");
4034 Read the README file in the top level directory;
4035 Read http://www.denx.de/twiki/bin/view/DULG/Manual;
4036 Read applicable doc/*.README;
4037 Read the source, Luke;
4038 /* find . -name "*.[chS]" | xargs grep -i <keyword> */
4041 if (available_money > toLocalCurrency ($2500))
4044 Add a lot of aggravation and time;
4046 if (a similar board exists) { /* hopefully... */
4047 cp -a board/<similar> board/<myboard>
4048 cp include/configs/<similar>.h include/configs/<myboard>.h
4050 Create your own board support subdirectory;
4051 Create your own board include/configs/<myboard>.h file;
4053 Edit new board/<myboard> files
4054 Edit new include/configs/<myboard>.h
4059 Add / modify source code;
4063 email("Hi, I am having problems...");
4065 Send patch file to the U-Boot email list;
4066 if (reasonable critiques)
4067 Incorporate improvements from email list code review;
4069 Defend code as written;
4075 void no_more_time (int sig)
4084 All contributions to U-Boot should conform to the Linux kernel
4085 coding style; see the file "Documentation/CodingStyle" and the script
4086 "scripts/Lindent" in your Linux kernel source directory. In sources
4087 originating from U-Boot a style corresponding to "Lindent -pcs" (adding
4088 spaces before parameters to function calls) is actually used.
4090 Source files originating from a different project (for example the
4091 MTD subsystem) are generally exempt from these guidelines and are not
4092 reformated to ease subsequent migration to newer versions of those
4095 Please note that U-Boot is implemented in C (and to some small parts in
4096 Assembler); no C++ is used, so please do not use C++ style comments (//)
4099 Please also stick to the following formatting rules:
4100 - remove any trailing white space
4101 - use TAB characters for indentation, not spaces
4102 - make sure NOT to use DOS '\r\n' line feeds
4103 - do not add more than 2 empty lines to source files
4104 - do not add trailing empty lines to source files
4106 Submissions which do not conform to the standards may be returned
4107 with a request to reformat the changes.
4113 Since the number of patches for U-Boot is growing, we need to
4114 establish some rules. Submissions which do not conform to these rules
4115 may be rejected, even when they contain important and valuable stuff.
4117 Please see http://www.denx.de/wiki/U-Boot/Patches for details.
4119 Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>;
4120 see http://lists.denx.de/mailman/listinfo/u-boot
4122 When you send a patch, please include the following information with
4125 * For bug fixes: a description of the bug and how your patch fixes
4126 this bug. Please try to include a way of demonstrating that the
4127 patch actually fixes something.
4129 * For new features: a description of the feature and your
4132 * A CHANGELOG entry as plaintext (separate from the patch)
4134 * For major contributions, your entry to the CREDITS file
4136 * When you add support for a new board, don't forget to add this
4137 board to the MAKEALL script, too.
4139 * If your patch adds new configuration options, don't forget to
4140 document these in the README file.
4142 * The patch itself. If you are using git (which is *strongly*
4143 recommended) you can easily generate the patch using the
4144 "git-format-patch". If you then use "git-send-email" to send it to
4145 the U-Boot mailing list, you will avoid most of the common problems
4146 with some other mail clients.
4148 If you cannot use git, use "diff -purN OLD NEW". If your version of
4149 diff does not support these options, then get the latest version of
4152 The current directory when running this command shall be the parent
4153 directory of the U-Boot source tree (i. e. please make sure that
4154 your patch includes sufficient directory information for the
4157 We prefer patches as plain text. MIME attachments are discouraged,
4158 and compressed attachments must not be used.
4160 * If one logical set of modifications affects or creates several
4161 files, all these changes shall be submitted in a SINGLE patch file.
4163 * Changesets that contain different, unrelated modifications shall be
4164 submitted as SEPARATE patches, one patch per changeset.
4169 * Before sending the patch, run the MAKEALL script on your patched
4170 source tree and make sure that no errors or warnings are reported
4171 for any of the boards.
4173 * Keep your modifications to the necessary minimum: A patch
4174 containing several unrelated changes or arbitrary reformats will be
4175 returned with a request to re-formatting / split it.
4177 * If you modify existing code, make sure that your new code does not
4178 add to the memory footprint of the code ;-) Small is beautiful!
4179 When adding new features, these should compile conditionally only
4180 (using #ifdef), and the resulting code with the new feature
4181 disabled must not need more memory than the old code without your
4184 * Remember that there is a size limit of 100 kB per message on the
4185 u-boot mailing list. Bigger patches will be moderated. If they are
4186 reasonable and not too big, they will be acknowledged. But patches
4187 bigger than the size limit should be avoided.
projects / people / ms / u-boot.git / blob