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 CONFIG_KEEP_SERVERADDR
1189 Keeps the server's MAC address, in the env 'serveraddr'
1190 for passing to bootargs (like Linux's netconsole option)
1192 - Multicast TFTP Mode:
1195 Defines whether you want to support multicast TFTP as per
1196 rfc-2090; for example to work with atftp. Lets lots of targets
1197 tftp down the same boot image concurrently. Note: the Ethernet
1198 driver in use must provide a function: mcast() to join/leave a
1201 CONFIG_BOOTP_RANDOM_DELAY
1202 - BOOTP Recovery Mode:
1203 CONFIG_BOOTP_RANDOM_DELAY
1205 If you have many targets in a network that try to
1206 boot using BOOTP, you may want to avoid that all
1207 systems send out BOOTP requests at precisely the same
1208 moment (which would happen for instance at recovery
1209 from a power failure, when all systems will try to
1210 boot, thus flooding the BOOTP server. Defining
1211 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
1212 inserted before sending out BOOTP requests. The
1213 following delays are inserted then:
1215 1st BOOTP request: delay 0 ... 1 sec
1216 2nd BOOTP request: delay 0 ... 2 sec
1217 3rd BOOTP request: delay 0 ... 4 sec
1219 BOOTP requests: delay 0 ... 8 sec
1221 - DHCP Advanced Options:
1222 You can fine tune the DHCP functionality by defining
1223 CONFIG_BOOTP_* symbols:
1225 CONFIG_BOOTP_SUBNETMASK
1226 CONFIG_BOOTP_GATEWAY
1227 CONFIG_BOOTP_HOSTNAME
1228 CONFIG_BOOTP_NISDOMAIN
1229 CONFIG_BOOTP_BOOTPATH
1230 CONFIG_BOOTP_BOOTFILESIZE
1233 CONFIG_BOOTP_SEND_HOSTNAME
1234 CONFIG_BOOTP_NTPSERVER
1235 CONFIG_BOOTP_TIMEOFFSET
1236 CONFIG_BOOTP_VENDOREX
1238 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip
1239 environment variable, not the BOOTP server.
1241 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS
1242 serverip from a DHCP server, it is possible that more
1243 than one DNS serverip is offered to the client.
1244 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS
1245 serverip will be stored in the additional environment
1246 variable "dnsip2". The first DNS serverip is always
1247 stored in the variable "dnsip", when CONFIG_BOOTP_DNS
1250 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable
1251 to do a dynamic update of a DNS server. To do this, they
1252 need the hostname of the DHCP requester.
1253 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content
1254 of the "hostname" environment variable is passed as
1255 option 12 to the DHCP server.
1257 CONFIG_BOOTP_DHCP_REQUEST_DELAY
1259 A 32bit value in microseconds for a delay between
1260 receiving a "DHCP Offer" and sending the "DHCP Request".
1261 This fixes a problem with certain DHCP servers that don't
1262 respond 100% of the time to a "DHCP request". E.g. On an
1263 AT91RM9200 processor running at 180MHz, this delay needed
1264 to be *at least* 15,000 usec before a Windows Server 2003
1265 DHCP server would reply 100% of the time. I recommend at
1266 least 50,000 usec to be safe. The alternative is to hope
1267 that one of the retries will be successful but note that
1268 the DHCP timeout and retry process takes a longer than
1272 CONFIG_CDP_DEVICE_ID
1274 The device id used in CDP trigger frames.
1276 CONFIG_CDP_DEVICE_ID_PREFIX
1278 A two character string which is prefixed to the MAC address
1283 A printf format string which contains the ascii name of
1284 the port. Normally is set to "eth%d" which sets
1285 eth0 for the first Ethernet, eth1 for the second etc.
1287 CONFIG_CDP_CAPABILITIES
1289 A 32bit integer which indicates the device capabilities;
1290 0x00000010 for a normal host which does not forwards.
1294 An ascii string containing the version of the software.
1298 An ascii string containing the name of the platform.
1302 A 32bit integer sent on the trigger.
1304 CONFIG_CDP_POWER_CONSUMPTION
1306 A 16bit integer containing the power consumption of the
1307 device in .1 of milliwatts.
1309 CONFIG_CDP_APPLIANCE_VLAN_TYPE
1311 A byte containing the id of the VLAN.
1313 - Status LED: CONFIG_STATUS_LED
1315 Several configurations allow to display the current
1316 status using a LED. For instance, the LED will blink
1317 fast while running U-Boot code, stop blinking as
1318 soon as a reply to a BOOTP request was received, and
1319 start blinking slow once the Linux kernel is running
1320 (supported by a status LED driver in the Linux
1321 kernel). Defining CONFIG_STATUS_LED enables this
1324 - CAN Support: CONFIG_CAN_DRIVER
1326 Defining CONFIG_CAN_DRIVER enables CAN driver support
1327 on those systems that support this (optional)
1328 feature, like the TQM8xxL modules.
1330 - I2C Support: CONFIG_HARD_I2C | CONFIG_SOFT_I2C
1332 These enable I2C serial bus commands. Defining either of
1333 (but not both of) CONFIG_HARD_I2C or CONFIG_SOFT_I2C will
1334 include the appropriate I2C driver for the selected CPU.
1336 This will allow you to use i2c commands at the u-boot
1337 command line (as long as you set CONFIG_CMD_I2C in
1338 CONFIG_COMMANDS) and communicate with i2c based realtime
1339 clock chips. See common/cmd_i2c.c for a description of the
1340 command line interface.
1342 CONFIG_HARD_I2C selects a hardware I2C controller.
1344 CONFIG_SOFT_I2C configures u-boot to use a software (aka
1345 bit-banging) driver instead of CPM or similar hardware
1348 There are several other quantities that must also be
1349 defined when you define CONFIG_HARD_I2C or CONFIG_SOFT_I2C.
1351 In both cases you will need to define CONFIG_SYS_I2C_SPEED
1352 to be the frequency (in Hz) at which you wish your i2c bus
1353 to run and CONFIG_SYS_I2C_SLAVE to be the address of this node (ie
1354 the CPU's i2c node address).
1356 Now, the u-boot i2c code for the mpc8xx (cpu/mpc8xx/i2c.c)
1357 sets the CPU up as a master node and so its address should
1358 therefore be cleared to 0 (See, eg, MPC823e User's Manual
1359 p.16-473). So, set CONFIG_SYS_I2C_SLAVE to 0.
1361 That's all that's required for CONFIG_HARD_I2C.
1363 If you use the software i2c interface (CONFIG_SOFT_I2C)
1364 then the following macros need to be defined (examples are
1365 from include/configs/lwmon.h):
1369 (Optional). Any commands necessary to enable the I2C
1370 controller or configure ports.
1372 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
1376 (Only for MPC8260 CPU). The I/O port to use (the code
1377 assumes both bits are on the same port). Valid values
1378 are 0..3 for ports A..D.
1382 The code necessary to make the I2C data line active
1383 (driven). If the data line is open collector, this
1386 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
1390 The code necessary to make the I2C data line tri-stated
1391 (inactive). If the data line is open collector, this
1394 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
1398 Code that returns TRUE if the I2C data line is high,
1401 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
1405 If <bit> is TRUE, sets the I2C data line high. If it
1406 is FALSE, it clears it (low).
1408 eg: #define I2C_SDA(bit) \
1409 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
1410 else immr->im_cpm.cp_pbdat &= ~PB_SDA
1414 If <bit> is TRUE, sets the I2C clock line high. If it
1415 is FALSE, it clears it (low).
1417 eg: #define I2C_SCL(bit) \
1418 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
1419 else immr->im_cpm.cp_pbdat &= ~PB_SCL
1423 This delay is invoked four times per clock cycle so this
1424 controls the rate of data transfer. The data rate thus
1425 is 1 / (I2C_DELAY * 4). Often defined to be something
1428 #define I2C_DELAY udelay(2)
1430 CONFIG_SYS_I2C_INIT_BOARD
1432 When a board is reset during an i2c bus transfer
1433 chips might think that the current transfer is still
1434 in progress. On some boards it is possible to access
1435 the i2c SCLK line directly, either by using the
1436 processor pin as a GPIO or by having a second pin
1437 connected to the bus. If this option is defined a
1438 custom i2c_init_board() routine in boards/xxx/board.c
1439 is run early in the boot sequence.
1441 CONFIG_I2CFAST (PPC405GP|PPC405EP only)
1443 This option enables configuration of bi_iic_fast[] flags
1444 in u-boot bd_info structure based on u-boot environment
1445 variable "i2cfast". (see also i2cfast)
1447 CONFIG_I2C_MULTI_BUS
1449 This option allows the use of multiple I2C buses, each of which
1450 must have a controller. At any point in time, only one bus is
1451 active. To switch to a different bus, use the 'i2c dev' command.
1452 Note that bus numbering is zero-based.
1454 CONFIG_SYS_I2C_NOPROBES
1456 This option specifies a list of I2C devices that will be skipped
1457 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS
1458 is set, specify a list of bus-device pairs. Otherwise, specify
1459 a 1D array of device addresses
1462 #undef CONFIG_I2C_MULTI_BUS
1463 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68}
1465 will skip addresses 0x50 and 0x68 on a board with one I2C bus
1467 #define CONFIG_I2C_MULTI_BUS
1468 #define CONFIG_SYS_I2C_MULTI_NOPROBES {{0,0x50},{0,0x68},{1,0x54}}
1470 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1
1472 CONFIG_SYS_SPD_BUS_NUM
1474 If defined, then this indicates the I2C bus number for DDR SPD.
1475 If not defined, then U-Boot assumes that SPD is on I2C bus 0.
1477 CONFIG_SYS_RTC_BUS_NUM
1479 If defined, then this indicates the I2C bus number for the RTC.
1480 If not defined, then U-Boot assumes that RTC is on I2C bus 0.
1482 CONFIG_SYS_DTT_BUS_NUM
1484 If defined, then this indicates the I2C bus number for the DTT.
1485 If not defined, then U-Boot assumes that DTT is on I2C bus 0.
1487 CONFIG_SYS_I2C_DTT_ADDR:
1489 If defined, specifies the I2C address of the DTT device.
1490 If not defined, then U-Boot uses predefined value for
1491 specified DTT device.
1495 Define this option if you want to use Freescale's I2C driver in
1496 drivers/i2c/fsl_i2c.c.
1500 Define this option if you have I2C devices reached over 1 .. n
1501 I2C Muxes like the pca9544a. This option addes a new I2C
1502 Command "i2c bus [muxtype:muxaddr:muxchannel]" which adds a
1503 new I2C Bus to the existing I2C Busses. If you select the
1504 new Bus with "i2c dev", u-bbot sends first the commandos for
1505 the muxes to activate this new "bus".
1507 CONFIG_I2C_MULTI_BUS must be also defined, to use this
1511 Adding a new I2C Bus reached over 2 pca9544a muxes
1512 The First mux with address 70 and channel 6
1513 The Second mux with address 71 and channel 4
1515 => i2c bus pca9544a:70:6:pca9544a:71:4
1517 Use the "i2c bus" command without parameter, to get a list
1518 of I2C Busses with muxes:
1521 Busses reached over muxes:
1523 reached over Mux(es):
1526 reached over Mux(es):
1531 If you now switch to the new I2C Bus 3 with "i2c dev 3"
1532 u-boot sends First the Commando to the mux@70 to enable
1533 channel 6, and then the Commando to the mux@71 to enable
1536 After that, you can use the "normal" i2c commands as
1537 usual, to communicate with your I2C devices behind
1540 This option is actually implemented for the bitbanging
1541 algorithm in common/soft_i2c.c and for the Hardware I2C
1542 Bus on the MPC8260. But it should be not so difficult
1543 to add this option to other architectures.
1545 CONFIG_SOFT_I2C_READ_REPEATED_START
1547 defining this will force the i2c_read() function in
1548 the soft_i2c driver to perform an I2C repeated start
1549 between writing the address pointer and reading the
1550 data. If this define is omitted the default behaviour
1551 of doing a stop-start sequence will be used. Most I2C
1552 devices can use either method, but some require one or
1555 - SPI Support: CONFIG_SPI
1557 Enables SPI driver (so far only tested with
1558 SPI EEPROM, also an instance works with Crystal A/D and
1559 D/As on the SACSng board)
1563 Enables extended (16-bit) SPI EEPROM addressing.
1564 (symmetrical to CONFIG_I2C_X)
1568 Enables a software (bit-bang) SPI driver rather than
1569 using hardware support. This is a general purpose
1570 driver that only requires three general I/O port pins
1571 (two outputs, one input) to function. If this is
1572 defined, the board configuration must define several
1573 SPI configuration items (port pins to use, etc). For
1574 an example, see include/configs/sacsng.h.
1578 Enables a hardware SPI driver for general-purpose reads
1579 and writes. As with CONFIG_SOFT_SPI, the board configuration
1580 must define a list of chip-select function pointers.
1581 Currently supported on some MPC8xxx processors. For an
1582 example, see include/configs/mpc8349emds.h.
1586 Enables the driver for the SPI controllers on i.MX and MXC
1587 SoCs. Currently only i.MX31 is supported.
1589 - FPGA Support: CONFIG_FPGA
1591 Enables FPGA subsystem.
1593 CONFIG_FPGA_<vendor>
1595 Enables support for specific chip vendors.
1598 CONFIG_FPGA_<family>
1600 Enables support for FPGA family.
1601 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX)
1605 Specify the number of FPGA devices to support.
1607 CONFIG_SYS_FPGA_PROG_FEEDBACK
1609 Enable printing of hash marks during FPGA configuration.
1611 CONFIG_SYS_FPGA_CHECK_BUSY
1613 Enable checks on FPGA configuration interface busy
1614 status by the configuration function. This option
1615 will require a board or device specific function to
1620 If defined, a function that provides delays in the FPGA
1621 configuration driver.
1623 CONFIG_SYS_FPGA_CHECK_CTRLC
1624 Allow Control-C to interrupt FPGA configuration
1626 CONFIG_SYS_FPGA_CHECK_ERROR
1628 Check for configuration errors during FPGA bitfile
1629 loading. For example, abort during Virtex II
1630 configuration if the INIT_B line goes low (which
1631 indicated a CRC error).
1633 CONFIG_SYS_FPGA_WAIT_INIT
1635 Maximum time to wait for the INIT_B line to deassert
1636 after PROB_B has been deasserted during a Virtex II
1637 FPGA configuration sequence. The default time is 500
1640 CONFIG_SYS_FPGA_WAIT_BUSY
1642 Maximum time to wait for BUSY to deassert during
1643 Virtex II FPGA configuration. The default is 5 ms.
1645 CONFIG_SYS_FPGA_WAIT_CONFIG
1647 Time to wait after FPGA configuration. The default is
1650 - Configuration Management:
1653 If defined, this string will be added to the U-Boot
1654 version information (U_BOOT_VERSION)
1656 - Vendor Parameter Protection:
1658 U-Boot considers the values of the environment
1659 variables "serial#" (Board Serial Number) and
1660 "ethaddr" (Ethernet Address) to be parameters that
1661 are set once by the board vendor / manufacturer, and
1662 protects these variables from casual modification by
1663 the user. Once set, these variables are read-only,
1664 and write or delete attempts are rejected. You can
1665 change this behaviour:
1667 If CONFIG_ENV_OVERWRITE is #defined in your config
1668 file, the write protection for vendor parameters is
1669 completely disabled. Anybody can change or delete
1672 Alternatively, if you #define _both_ CONFIG_ETHADDR
1673 _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
1674 Ethernet address is installed in the environment,
1675 which can be changed exactly ONCE by the user. [The
1676 serial# is unaffected by this, i. e. it remains
1682 Define this variable to enable the reservation of
1683 "protected RAM", i. e. RAM which is not overwritten
1684 by U-Boot. Define CONFIG_PRAM to hold the number of
1685 kB you want to reserve for pRAM. You can overwrite
1686 this default value by defining an environment
1687 variable "pram" to the number of kB you want to
1688 reserve. Note that the board info structure will
1689 still show the full amount of RAM. If pRAM is
1690 reserved, a new environment variable "mem" will
1691 automatically be defined to hold the amount of
1692 remaining RAM in a form that can be passed as boot
1693 argument to Linux, for instance like that:
1695 setenv bootargs ... mem=\${mem}
1698 This way you can tell Linux not to use this memory,
1699 either, which results in a memory region that will
1700 not be affected by reboots.
1702 *WARNING* If your board configuration uses automatic
1703 detection of the RAM size, you must make sure that
1704 this memory test is non-destructive. So far, the
1705 following board configurations are known to be
1708 ETX094, IVMS8, IVML24, SPD8xx, TQM8xxL,
1709 HERMES, IP860, RPXlite, LWMON, LANTEC,
1710 PCU_E, FLAGADM, TQM8260
1715 Define this variable to stop the system in case of a
1716 fatal error, so that you have to reset it manually.
1717 This is probably NOT a good idea for an embedded
1718 system where you want the system to reboot
1719 automatically as fast as possible, but it may be
1720 useful during development since you can try to debug
1721 the conditions that lead to the situation.
1723 CONFIG_NET_RETRY_COUNT
1725 This variable defines the number of retries for
1726 network operations like ARP, RARP, TFTP, or BOOTP
1727 before giving up the operation. If not defined, a
1728 default value of 5 is used.
1732 Timeout waiting for an ARP reply in milliseconds.
1734 - Command Interpreter:
1735 CONFIG_AUTO_COMPLETE
1737 Enable auto completion of commands using TAB.
1739 Note that this feature has NOT been implemented yet
1740 for the "hush" shell.
1743 CONFIG_SYS_HUSH_PARSER
1745 Define this variable to enable the "hush" shell (from
1746 Busybox) as command line interpreter, thus enabling
1747 powerful command line syntax like
1748 if...then...else...fi conditionals or `&&' and '||'
1749 constructs ("shell scripts").
1751 If undefined, you get the old, much simpler behaviour
1752 with a somewhat smaller memory footprint.
1755 CONFIG_SYS_PROMPT_HUSH_PS2
1757 This defines the secondary prompt string, which is
1758 printed when the command interpreter needs more input
1759 to complete a command. Usually "> ".
1763 In the current implementation, the local variables
1764 space and global environment variables space are
1765 separated. Local variables are those you define by
1766 simply typing `name=value'. To access a local
1767 variable later on, you have write `$name' or
1768 `${name}'; to execute the contents of a variable
1769 directly type `$name' at the command prompt.
1771 Global environment variables are those you use
1772 setenv/printenv to work with. To run a command stored
1773 in such a variable, you need to use the run command,
1774 and you must not use the '$' sign to access them.
1776 To store commands and special characters in a
1777 variable, please use double quotation marks
1778 surrounding the whole text of the variable, instead
1779 of the backslashes before semicolons and special
1782 - Commandline Editing and History:
1783 CONFIG_CMDLINE_EDITING
1785 Enable editing and History functions for interactive
1786 commandline input operations
1788 - Default Environment:
1789 CONFIG_EXTRA_ENV_SETTINGS
1791 Define this to contain any number of null terminated
1792 strings (variable = value pairs) that will be part of
1793 the default environment compiled into the boot image.
1795 For example, place something like this in your
1796 board's config file:
1798 #define CONFIG_EXTRA_ENV_SETTINGS \
1802 Warning: This method is based on knowledge about the
1803 internal format how the environment is stored by the
1804 U-Boot code. This is NOT an official, exported
1805 interface! Although it is unlikely that this format
1806 will change soon, there is no guarantee either.
1807 You better know what you are doing here.
1809 Note: overly (ab)use of the default environment is
1810 discouraged. Make sure to check other ways to preset
1811 the environment like the "source" command or the
1814 - DataFlash Support:
1815 CONFIG_HAS_DATAFLASH
1817 Defining this option enables DataFlash features and
1818 allows to read/write in Dataflash via the standard
1821 - SystemACE Support:
1824 Adding this option adds support for Xilinx SystemACE
1825 chips attached via some sort of local bus. The address
1826 of the chip must also be defined in the
1827 CONFIG_SYS_SYSTEMACE_BASE macro. For example:
1829 #define CONFIG_SYSTEMACE
1830 #define CONFIG_SYS_SYSTEMACE_BASE 0xf0000000
1832 When SystemACE support is added, the "ace" device type
1833 becomes available to the fat commands, i.e. fatls.
1835 - TFTP Fixed UDP Port:
1838 If this is defined, the environment variable tftpsrcp
1839 is used to supply the TFTP UDP source port value.
1840 If tftpsrcp isn't defined, the normal pseudo-random port
1841 number generator is used.
1843 Also, the environment variable tftpdstp is used to supply
1844 the TFTP UDP destination port value. If tftpdstp isn't
1845 defined, the normal port 69 is used.
1847 The purpose for tftpsrcp is to allow a TFTP server to
1848 blindly start the TFTP transfer using the pre-configured
1849 target IP address and UDP port. This has the effect of
1850 "punching through" the (Windows XP) firewall, allowing
1851 the remainder of the TFTP transfer to proceed normally.
1852 A better solution is to properly configure the firewall,
1853 but sometimes that is not allowed.
1855 - Show boot progress:
1856 CONFIG_SHOW_BOOT_PROGRESS
1858 Defining this option allows to add some board-
1859 specific code (calling a user-provided function
1860 "show_boot_progress(int)") that enables you to show
1861 the system's boot progress on some display (for
1862 example, some LED's) on your board. At the moment,
1863 the following checkpoints are implemented:
1865 - Automatic software updates via TFTP server
1867 CONFIG_UPDATE_TFTP_CNT_MAX
1868 CONFIG_UPDATE_TFTP_MSEC_MAX
1870 These options enable and control the auto-update feature;
1871 for a more detailed description refer to doc/README.update.
1873 - MTD Support (mtdparts command, UBI support)
1876 Adds the MTD device infrastructure from the Linux kernel.
1877 Needed for mtdparts command support.
1879 CONFIG_MTD_PARTITIONS
1881 Adds the MTD partitioning infrastructure from the Linux
1882 kernel. Needed for UBI support.
1884 Legacy uImage format:
1887 1 common/cmd_bootm.c before attempting to boot an image
1888 -1 common/cmd_bootm.c Image header has bad magic number
1889 2 common/cmd_bootm.c Image header has correct magic number
1890 -2 common/cmd_bootm.c Image header has bad checksum
1891 3 common/cmd_bootm.c Image header has correct checksum
1892 -3 common/cmd_bootm.c Image data has bad checksum
1893 4 common/cmd_bootm.c Image data has correct checksum
1894 -4 common/cmd_bootm.c Image is for unsupported architecture
1895 5 common/cmd_bootm.c Architecture check OK
1896 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi)
1897 6 common/cmd_bootm.c Image Type check OK
1898 -6 common/cmd_bootm.c gunzip uncompression error
1899 -7 common/cmd_bootm.c Unimplemented compression type
1900 7 common/cmd_bootm.c Uncompression OK
1901 8 common/cmd_bootm.c No uncompress/copy overwrite error
1902 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX)
1904 9 common/image.c Start initial ramdisk verification
1905 -10 common/image.c Ramdisk header has bad magic number
1906 -11 common/image.c Ramdisk header has bad checksum
1907 10 common/image.c Ramdisk header is OK
1908 -12 common/image.c Ramdisk data has bad checksum
1909 11 common/image.c Ramdisk data has correct checksum
1910 12 common/image.c Ramdisk verification complete, start loading
1911 -13 common/image.c Wrong Image Type (not PPC Linux ramdisk)
1912 13 common/image.c Start multifile image verification
1913 14 common/image.c No initial ramdisk, no multifile, continue.
1915 15 lib_<arch>/bootm.c All preparation done, transferring control to OS
1917 -30 lib_ppc/board.c Fatal error, hang the system
1918 -31 post/post.c POST test failed, detected by post_output_backlog()
1919 -32 post/post.c POST test failed, detected by post_run_single()
1921 34 common/cmd_doc.c before loading a Image from a DOC device
1922 -35 common/cmd_doc.c Bad usage of "doc" command
1923 35 common/cmd_doc.c correct usage of "doc" command
1924 -36 common/cmd_doc.c No boot device
1925 36 common/cmd_doc.c correct boot device
1926 -37 common/cmd_doc.c Unknown Chip ID on boot device
1927 37 common/cmd_doc.c correct chip ID found, device available
1928 -38 common/cmd_doc.c Read Error on boot device
1929 38 common/cmd_doc.c reading Image header from DOC device OK
1930 -39 common/cmd_doc.c Image header has bad magic number
1931 39 common/cmd_doc.c Image header has correct magic number
1932 -40 common/cmd_doc.c Error reading Image from DOC device
1933 40 common/cmd_doc.c Image header has correct magic number
1934 41 common/cmd_ide.c before loading a Image from a IDE device
1935 -42 common/cmd_ide.c Bad usage of "ide" command
1936 42 common/cmd_ide.c correct usage of "ide" command
1937 -43 common/cmd_ide.c No boot device
1938 43 common/cmd_ide.c boot device found
1939 -44 common/cmd_ide.c Device not available
1940 44 common/cmd_ide.c Device available
1941 -45 common/cmd_ide.c wrong partition selected
1942 45 common/cmd_ide.c partition selected
1943 -46 common/cmd_ide.c Unknown partition table
1944 46 common/cmd_ide.c valid partition table found
1945 -47 common/cmd_ide.c Invalid partition type
1946 47 common/cmd_ide.c correct partition type
1947 -48 common/cmd_ide.c Error reading Image Header on boot device
1948 48 common/cmd_ide.c reading Image Header from IDE device OK
1949 -49 common/cmd_ide.c Image header has bad magic number
1950 49 common/cmd_ide.c Image header has correct magic number
1951 -50 common/cmd_ide.c Image header has bad checksum
1952 50 common/cmd_ide.c Image header has correct checksum
1953 -51 common/cmd_ide.c Error reading Image from IDE device
1954 51 common/cmd_ide.c reading Image from IDE device OK
1955 52 common/cmd_nand.c before loading a Image from a NAND device
1956 -53 common/cmd_nand.c Bad usage of "nand" command
1957 53 common/cmd_nand.c correct usage of "nand" command
1958 -54 common/cmd_nand.c No boot device
1959 54 common/cmd_nand.c boot device found
1960 -55 common/cmd_nand.c Unknown Chip ID on boot device
1961 55 common/cmd_nand.c correct chip ID found, device available
1962 -56 common/cmd_nand.c Error reading Image Header on boot device
1963 56 common/cmd_nand.c reading Image Header from NAND device OK
1964 -57 common/cmd_nand.c Image header has bad magic number
1965 57 common/cmd_nand.c Image header has correct magic number
1966 -58 common/cmd_nand.c Error reading Image from NAND device
1967 58 common/cmd_nand.c reading Image from NAND device OK
1969 -60 common/env_common.c Environment has a bad CRC, using default
1971 64 net/eth.c starting with Ethernet configuration.
1972 -64 net/eth.c no Ethernet found.
1973 65 net/eth.c Ethernet found.
1975 -80 common/cmd_net.c usage wrong
1976 80 common/cmd_net.c before calling NetLoop()
1977 -81 common/cmd_net.c some error in NetLoop() occurred
1978 81 common/cmd_net.c NetLoop() back without error
1979 -82 common/cmd_net.c size == 0 (File with size 0 loaded)
1980 82 common/cmd_net.c trying automatic boot
1981 83 common/cmd_net.c running "source" command
1982 -83 common/cmd_net.c some error in automatic boot or "source" command
1983 84 common/cmd_net.c end without errors
1988 100 common/cmd_bootm.c Kernel FIT Image has correct format
1989 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format
1990 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration
1991 -101 common/cmd_bootm.c Can't get configuration for kernel subimage
1992 102 common/cmd_bootm.c Kernel unit name specified
1993 -103 common/cmd_bootm.c Can't get kernel subimage node offset
1994 103 common/cmd_bootm.c Found configuration node
1995 104 common/cmd_bootm.c Got kernel subimage node offset
1996 -104 common/cmd_bootm.c Kernel subimage hash verification failed
1997 105 common/cmd_bootm.c Kernel subimage hash verification OK
1998 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture
1999 106 common/cmd_bootm.c Architecture check OK
2000 -106 common/cmd_bootm.c Kernel subimage has wrong type
2001 107 common/cmd_bootm.c Kernel subimage type OK
2002 -107 common/cmd_bootm.c Can't get kernel subimage data/size
2003 108 common/cmd_bootm.c Got kernel subimage data/size
2004 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT)
2005 -109 common/cmd_bootm.c Can't get kernel subimage type
2006 -110 common/cmd_bootm.c Can't get kernel subimage comp
2007 -111 common/cmd_bootm.c Can't get kernel subimage os
2008 -112 common/cmd_bootm.c Can't get kernel subimage load address
2009 -113 common/cmd_bootm.c Image uncompress/copy overwrite error
2011 120 common/image.c Start initial ramdisk verification
2012 -120 common/image.c Ramdisk FIT image has incorrect format
2013 121 common/image.c Ramdisk FIT image has correct format
2014 122 common/image.c No ramdisk subimage unit name, using configuration
2015 -122 common/image.c Can't get configuration for ramdisk subimage
2016 123 common/image.c Ramdisk unit name specified
2017 -124 common/image.c Can't get ramdisk subimage node offset
2018 125 common/image.c Got ramdisk subimage node offset
2019 -125 common/image.c Ramdisk subimage hash verification failed
2020 126 common/image.c Ramdisk subimage hash verification OK
2021 -126 common/image.c Ramdisk subimage for unsupported architecture
2022 127 common/image.c Architecture check OK
2023 -127 common/image.c Can't get ramdisk subimage data/size
2024 128 common/image.c Got ramdisk subimage data/size
2025 129 common/image.c Can't get ramdisk load address
2026 -129 common/image.c Got ramdisk load address
2028 -130 common/cmd_doc.c Incorrect FIT image format
2029 131 common/cmd_doc.c FIT image format OK
2031 -140 common/cmd_ide.c Incorrect FIT image format
2032 141 common/cmd_ide.c FIT image format OK
2034 -150 common/cmd_nand.c Incorrect FIT image format
2035 151 common/cmd_nand.c FIT image format OK
2041 [so far only for SMDK2400 and TRAB boards]
2043 - Modem support enable:
2044 CONFIG_MODEM_SUPPORT
2046 - RTS/CTS Flow control enable:
2049 - Modem debug support:
2050 CONFIG_MODEM_SUPPORT_DEBUG
2052 Enables debugging stuff (char screen[1024], dbg())
2053 for modem support. Useful only with BDI2000.
2055 - Interrupt support (PPC):
2057 There are common interrupt_init() and timer_interrupt()
2058 for all PPC archs. interrupt_init() calls interrupt_init_cpu()
2059 for CPU specific initialization. interrupt_init_cpu()
2060 should set decrementer_count to appropriate value. If
2061 CPU resets decrementer automatically after interrupt
2062 (ppc4xx) it should set decrementer_count to zero.
2063 timer_interrupt() calls timer_interrupt_cpu() for CPU
2064 specific handling. If board has watchdog / status_led
2065 / other_activity_monitor it works automatically from
2066 general timer_interrupt().
2070 In the target system modem support is enabled when a
2071 specific key (key combination) is pressed during
2072 power-on. Otherwise U-Boot will boot normally
2073 (autoboot). The key_pressed() function is called from
2074 board_init(). Currently key_pressed() is a dummy
2075 function, returning 1 and thus enabling modem
2078 If there are no modem init strings in the
2079 environment, U-Boot proceed to autoboot; the
2080 previous output (banner, info printfs) will be
2083 See also: doc/README.Modem
2086 Configuration Settings:
2087 -----------------------
2089 - CONFIG_SYS_LONGHELP: Defined when you want long help messages included;
2090 undefine this when you're short of memory.
2092 - CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default
2093 width of the commands listed in the 'help' command output.
2095 - CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to
2096 prompt for user input.
2098 - CONFIG_SYS_CBSIZE: Buffer size for input from the Console
2100 - CONFIG_SYS_PBSIZE: Buffer size for Console output
2102 - CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands
2104 - CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to
2105 the application (usually a Linux kernel) when it is
2108 - CONFIG_SYS_BAUDRATE_TABLE:
2109 List of legal baudrate settings for this board.
2111 - CONFIG_SYS_CONSOLE_INFO_QUIET
2112 Suppress display of console information at boot.
2114 - CONFIG_SYS_CONSOLE_IS_IN_ENV
2115 If the board specific function
2116 extern int overwrite_console (void);
2117 returns 1, the stdin, stderr and stdout are switched to the
2118 serial port, else the settings in the environment are used.
2120 - CONFIG_SYS_CONSOLE_OVERWRITE_ROUTINE
2121 Enable the call to overwrite_console().
2123 - CONFIG_SYS_CONSOLE_ENV_OVERWRITE
2124 Enable overwrite of previous console environment settings.
2126 - CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END:
2127 Begin and End addresses of the area used by the
2130 - CONFIG_SYS_ALT_MEMTEST:
2131 Enable an alternate, more extensive memory test.
2133 - CONFIG_SYS_MEMTEST_SCRATCH:
2134 Scratch address used by the alternate memory test
2135 You only need to set this if address zero isn't writeable
2137 - CONFIG_SYS_MEM_TOP_HIDE (PPC only):
2138 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header,
2139 this specified memory area will get subtracted from the top
2140 (end) of RAM and won't get "touched" at all by U-Boot. By
2141 fixing up gd->ram_size the Linux kernel should gets passed
2142 the now "corrected" memory size and won't touch it either.
2143 This should work for arch/ppc and arch/powerpc. Only Linux
2144 board ports in arch/powerpc with bootwrapper support that
2145 recalculate the memory size from the SDRAM controller setup
2146 will have to get fixed in Linux additionally.
2148 This option can be used as a workaround for the 440EPx/GRx
2149 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't
2152 WARNING: Please make sure that this value is a multiple of
2153 the Linux page size (normally 4k). If this is not the case,
2154 then the end address of the Linux memory will be located at a
2155 non page size aligned address and this could cause major
2158 - CONFIG_SYS_TFTP_LOADADDR:
2159 Default load address for network file downloads
2161 - CONFIG_SYS_LOADS_BAUD_CHANGE:
2162 Enable temporary baudrate change while serial download
2164 - CONFIG_SYS_SDRAM_BASE:
2165 Physical start address of SDRAM. _Must_ be 0 here.
2167 - CONFIG_SYS_MBIO_BASE:
2168 Physical start address of Motherboard I/O (if using a
2171 - CONFIG_SYS_FLASH_BASE:
2172 Physical start address of Flash memory.
2174 - CONFIG_SYS_MONITOR_BASE:
2175 Physical start address of boot monitor code (set by
2176 make config files to be same as the text base address
2177 (TEXT_BASE) used when linking) - same as
2178 CONFIG_SYS_FLASH_BASE when booting from flash.
2180 - CONFIG_SYS_MONITOR_LEN:
2181 Size of memory reserved for monitor code, used to
2182 determine _at_compile_time_ (!) if the environment is
2183 embedded within the U-Boot image, or in a separate
2186 - CONFIG_SYS_MALLOC_LEN:
2187 Size of DRAM reserved for malloc() use.
2189 - CONFIG_SYS_BOOTM_LEN:
2190 Normally compressed uImages are limited to an
2191 uncompressed size of 8 MBytes. If this is not enough,
2192 you can define CONFIG_SYS_BOOTM_LEN in your board config file
2193 to adjust this setting to your needs.
2195 - CONFIG_SYS_BOOTMAPSZ:
2196 Maximum size of memory mapped by the startup code of
2197 the Linux kernel; all data that must be processed by
2198 the Linux kernel (bd_info, boot arguments, FDT blob if
2199 used) must be put below this limit, unless "bootm_low"
2200 enviroment variable is defined and non-zero. In such case
2201 all data for the Linux kernel must be between "bootm_low"
2202 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ.
2204 - CONFIG_SYS_MAX_FLASH_BANKS:
2205 Max number of Flash memory banks
2207 - CONFIG_SYS_MAX_FLASH_SECT:
2208 Max number of sectors on a Flash chip
2210 - CONFIG_SYS_FLASH_ERASE_TOUT:
2211 Timeout for Flash erase operations (in ms)
2213 - CONFIG_SYS_FLASH_WRITE_TOUT:
2214 Timeout for Flash write operations (in ms)
2216 - CONFIG_SYS_FLASH_LOCK_TOUT
2217 Timeout for Flash set sector lock bit operation (in ms)
2219 - CONFIG_SYS_FLASH_UNLOCK_TOUT
2220 Timeout for Flash clear lock bits operation (in ms)
2222 - CONFIG_SYS_FLASH_PROTECTION
2223 If defined, hardware flash sectors protection is used
2224 instead of U-Boot software protection.
2226 - CONFIG_SYS_DIRECT_FLASH_TFTP:
2228 Enable TFTP transfers directly to flash memory;
2229 without this option such a download has to be
2230 performed in two steps: (1) download to RAM, and (2)
2231 copy from RAM to flash.
2233 The two-step approach is usually more reliable, since
2234 you can check if the download worked before you erase
2235 the flash, but in some situations (when system RAM is
2236 too limited to allow for a temporary copy of the
2237 downloaded image) this option may be very useful.
2239 - CONFIG_SYS_FLASH_CFI:
2240 Define if the flash driver uses extra elements in the
2241 common flash structure for storing flash geometry.
2243 - CONFIG_FLASH_CFI_DRIVER
2244 This option also enables the building of the cfi_flash driver
2245 in the drivers directory
2247 - CONFIG_FLASH_CFI_MTD
2248 This option enables the building of the cfi_mtd driver
2249 in the drivers directory. The driver exports CFI flash
2252 - CONFIG_SYS_FLASH_USE_BUFFER_WRITE
2253 Use buffered writes to flash.
2255 - CONFIG_FLASH_SPANSION_S29WS_N
2256 s29ws-n MirrorBit flash has non-standard addresses for buffered
2259 - CONFIG_SYS_FLASH_QUIET_TEST
2260 If this option is defined, the common CFI flash doesn't
2261 print it's warning upon not recognized FLASH banks. This
2262 is useful, if some of the configured banks are only
2263 optionally available.
2265 - CONFIG_FLASH_SHOW_PROGRESS
2266 If defined (must be an integer), print out countdown
2267 digits and dots. Recommended value: 45 (9..1) for 80
2268 column displays, 15 (3..1) for 40 column displays.
2270 - CONFIG_SYS_RX_ETH_BUFFER:
2271 Defines the number of Ethernet receive buffers. On some
2272 Ethernet controllers it is recommended to set this value
2273 to 8 or even higher (EEPRO100 or 405 EMAC), since all
2274 buffers can be full shortly after enabling the interface
2275 on high Ethernet traffic.
2276 Defaults to 4 if not defined.
2278 The following definitions that deal with the placement and management
2279 of environment data (variable area); in general, we support the
2280 following configurations:
2282 - CONFIG_ENV_IS_IN_FLASH:
2284 Define this if the environment is in flash memory.
2286 a) The environment occupies one whole flash sector, which is
2287 "embedded" in the text segment with the U-Boot code. This
2288 happens usually with "bottom boot sector" or "top boot
2289 sector" type flash chips, which have several smaller
2290 sectors at the start or the end. For instance, such a
2291 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In
2292 such a case you would place the environment in one of the
2293 4 kB sectors - with U-Boot code before and after it. With
2294 "top boot sector" type flash chips, you would put the
2295 environment in one of the last sectors, leaving a gap
2296 between U-Boot and the environment.
2298 - CONFIG_ENV_OFFSET:
2300 Offset of environment data (variable area) to the
2301 beginning of flash memory; for instance, with bottom boot
2302 type flash chips the second sector can be used: the offset
2303 for this sector is given here.
2305 CONFIG_ENV_OFFSET is used relative to CONFIG_SYS_FLASH_BASE.
2309 This is just another way to specify the start address of
2310 the flash sector containing the environment (instead of
2313 - CONFIG_ENV_SECT_SIZE:
2315 Size of the sector containing the environment.
2318 b) Sometimes flash chips have few, equal sized, BIG sectors.
2319 In such a case you don't want to spend a whole sector for
2324 If you use this in combination with CONFIG_ENV_IS_IN_FLASH
2325 and CONFIG_ENV_SECT_SIZE, you can specify to use only a part
2326 of this flash sector for the environment. This saves
2327 memory for the RAM copy of the environment.
2329 It may also save flash memory if you decide to use this
2330 when your environment is "embedded" within U-Boot code,
2331 since then the remainder of the flash sector could be used
2332 for U-Boot code. It should be pointed out that this is
2333 STRONGLY DISCOURAGED from a robustness point of view:
2334 updating the environment in flash makes it always
2335 necessary to erase the WHOLE sector. If something goes
2336 wrong before the contents has been restored from a copy in
2337 RAM, your target system will be dead.
2339 - CONFIG_ENV_ADDR_REDUND
2340 CONFIG_ENV_SIZE_REDUND
2342 These settings describe a second storage area used to hold
2343 a redundant copy of the environment data, so that there is
2344 a valid backup copy in case there is a power failure during
2345 a "saveenv" operation.
2347 BE CAREFUL! Any changes to the flash layout, and some changes to the
2348 source code will make it necessary to adapt <board>/u-boot.lds*
2352 - CONFIG_ENV_IS_IN_NVRAM:
2354 Define this if you have some non-volatile memory device
2355 (NVRAM, battery buffered SRAM) which you want to use for the
2361 These two #defines are used to determine the memory area you
2362 want to use for environment. It is assumed that this memory
2363 can just be read and written to, without any special
2366 BE CAREFUL! The first access to the environment happens quite early
2367 in U-Boot initalization (when we try to get the setting of for the
2368 console baudrate). You *MUST* have mapped your NVRAM area then, or
2371 Please note that even with NVRAM we still use a copy of the
2372 environment in RAM: we could work on NVRAM directly, but we want to
2373 keep settings there always unmodified except somebody uses "saveenv"
2374 to save the current settings.
2377 - CONFIG_ENV_IS_IN_EEPROM:
2379 Use this if you have an EEPROM or similar serial access
2380 device and a driver for it.
2382 - CONFIG_ENV_OFFSET:
2385 These two #defines specify the offset and size of the
2386 environment area within the total memory of your EEPROM.
2388 - CONFIG_SYS_I2C_EEPROM_ADDR:
2389 If defined, specified the chip address of the EEPROM device.
2390 The default address is zero.
2392 - CONFIG_SYS_EEPROM_PAGE_WRITE_BITS:
2393 If defined, the number of bits used to address bytes in a
2394 single page in the EEPROM device. A 64 byte page, for example
2395 would require six bits.
2397 - CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS:
2398 If defined, the number of milliseconds to delay between
2399 page writes. The default is zero milliseconds.
2401 - CONFIG_SYS_I2C_EEPROM_ADDR_LEN:
2402 The length in bytes of the EEPROM memory array address. Note
2403 that this is NOT the chip address length!
2405 - CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW:
2406 EEPROM chips that implement "address overflow" are ones
2407 like Catalyst 24WC04/08/16 which has 9/10/11 bits of
2408 address and the extra bits end up in the "chip address" bit
2409 slots. This makes a 24WC08 (1Kbyte) chip look like four 256
2412 Note that we consider the length of the address field to
2413 still be one byte because the extra address bits are hidden
2414 in the chip address.
2416 - CONFIG_SYS_EEPROM_SIZE:
2417 The size in bytes of the EEPROM device.
2420 - CONFIG_ENV_IS_IN_DATAFLASH:
2422 Define this if you have a DataFlash memory device which you
2423 want to use for the environment.
2425 - CONFIG_ENV_OFFSET:
2429 These three #defines specify the offset and size of the
2430 environment area within the total memory of your DataFlash placed
2431 at the specified address.
2433 - CONFIG_ENV_IS_IN_NAND:
2435 Define this if you have a NAND device which you want to use
2436 for the environment.
2438 - CONFIG_ENV_OFFSET:
2441 These two #defines specify the offset and size of the environment
2442 area within the first NAND device.
2444 - CONFIG_ENV_OFFSET_REDUND
2446 This setting describes a second storage area of CONFIG_ENV_SIZE
2447 size used to hold a redundant copy of the environment data,
2448 so that there is a valid backup copy in case there is a
2449 power failure during a "saveenv" operation.
2451 Note: CONFIG_ENV_OFFSET and CONFIG_ENV_OFFSET_REDUND must be aligned
2452 to a block boundary, and CONFIG_ENV_SIZE must be a multiple of
2453 the NAND devices block size.
2455 - CONFIG_NAND_ENV_DST
2457 Defines address in RAM to which the nand_spl code should copy the
2458 environment. If redundant environment is used, it will be copied to
2459 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE.
2461 - CONFIG_SYS_SPI_INIT_OFFSET
2463 Defines offset to the initial SPI buffer area in DPRAM. The
2464 area is used at an early stage (ROM part) if the environment
2465 is configured to reside in the SPI EEPROM: We need a 520 byte
2466 scratch DPRAM area. It is used between the two initialization
2467 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems
2468 to be a good choice since it makes it far enough from the
2469 start of the data area as well as from the stack pointer.
2471 Please note that the environment is read-only until the monitor
2472 has been relocated to RAM and a RAM copy of the environment has been
2473 created; also, when using EEPROM you will have to use getenv_r()
2474 until then to read environment variables.
2476 The environment is protected by a CRC32 checksum. Before the monitor
2477 is relocated into RAM, as a result of a bad CRC you will be working
2478 with the compiled-in default environment - *silently*!!! [This is
2479 necessary, because the first environment variable we need is the
2480 "baudrate" setting for the console - if we have a bad CRC, we don't
2481 have any device yet where we could complain.]
2483 Note: once the monitor has been relocated, then it will complain if
2484 the default environment is used; a new CRC is computed as soon as you
2485 use the "saveenv" command to store a valid environment.
2487 - CONFIG_SYS_FAULT_ECHO_LINK_DOWN:
2488 Echo the inverted Ethernet link state to the fault LED.
2490 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR
2491 also needs to be defined.
2493 - CONFIG_SYS_FAULT_MII_ADDR:
2494 MII address of the PHY to check for the Ethernet link state.
2496 - CONFIG_SYS_64BIT_VSPRINTF:
2497 Makes vsprintf (and all *printf functions) support printing
2498 of 64bit values by using the L quantifier
2500 - CONFIG_SYS_64BIT_STRTOUL:
2501 Adds simple_strtoull that returns a 64bit value
2503 - CONFIG_NS16550_MIN_FUNCTIONS:
2504 Define this if you desire to only have use of the NS16550_init
2505 and NS16550_putc functions for the serial driver located at
2506 drivers/serial/ns16550.c. This option is useful for saving
2507 space for already greatly restricted images, including but not
2508 limited to NAND_SPL configurations.
2510 Low Level (hardware related) configuration options:
2511 ---------------------------------------------------
2513 - CONFIG_SYS_CACHELINE_SIZE:
2514 Cache Line Size of the CPU.
2516 - CONFIG_SYS_DEFAULT_IMMR:
2517 Default address of the IMMR after system reset.
2519 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU,
2520 and RPXsuper) to be able to adjust the position of
2521 the IMMR register after a reset.
2523 - Floppy Disk Support:
2524 CONFIG_SYS_FDC_DRIVE_NUMBER
2526 the default drive number (default value 0)
2528 CONFIG_SYS_ISA_IO_STRIDE
2530 defines the spacing between FDC chipset registers
2533 CONFIG_SYS_ISA_IO_OFFSET
2535 defines the offset of register from address. It
2536 depends on which part of the data bus is connected to
2537 the FDC chipset. (default value 0)
2539 If CONFIG_SYS_ISA_IO_STRIDE CONFIG_SYS_ISA_IO_OFFSET and
2540 CONFIG_SYS_FDC_DRIVE_NUMBER are undefined, they take their
2543 if CONFIG_SYS_FDC_HW_INIT is defined, then the function
2544 fdc_hw_init() is called at the beginning of the FDC
2545 setup. fdc_hw_init() must be provided by the board
2546 source code. It is used to make hardware dependant
2549 - CONFIG_SYS_IMMR: Physical address of the Internal Memory.
2550 DO NOT CHANGE unless you know exactly what you're
2551 doing! (11-4) [MPC8xx/82xx systems only]
2553 - CONFIG_SYS_INIT_RAM_ADDR:
2555 Start address of memory area that can be used for
2556 initial data and stack; please note that this must be
2557 writable memory that is working WITHOUT special
2558 initialization, i. e. you CANNOT use normal RAM which
2559 will become available only after programming the
2560 memory controller and running certain initialization
2563 U-Boot uses the following memory types:
2564 - MPC8xx and MPC8260: IMMR (internal memory of the CPU)
2565 - MPC824X: data cache
2566 - PPC4xx: data cache
2568 - CONFIG_SYS_GBL_DATA_OFFSET:
2570 Offset of the initial data structure in the memory
2571 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually
2572 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial
2573 data is located at the end of the available space
2574 (sometimes written as (CONFIG_SYS_INIT_RAM_END -
2575 CONFIG_SYS_INIT_DATA_SIZE), and the initial stack is just
2576 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR +
2577 CONFIG_SYS_GBL_DATA_OFFSET) downward.
2580 On the MPC824X (or other systems that use the data
2581 cache for initial memory) the address chosen for
2582 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must
2583 point to an otherwise UNUSED address space between
2584 the top of RAM and the start of the PCI space.
2586 - CONFIG_SYS_SIUMCR: SIU Module Configuration (11-6)
2588 - CONFIG_SYS_SYPCR: System Protection Control (11-9)
2590 - CONFIG_SYS_TBSCR: Time Base Status and Control (11-26)
2592 - CONFIG_SYS_PISCR: Periodic Interrupt Status and Control (11-31)
2594 - CONFIG_SYS_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30)
2596 - CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27)
2598 - CONFIG_SYS_OR_TIMING_SDRAM:
2601 - CONFIG_SYS_MAMR_PTA:
2602 periodic timer for refresh
2604 - CONFIG_SYS_DER: Debug Event Register (37-47)
2606 - FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM,
2607 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP,
2608 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM,
2609 CONFIG_SYS_BR1_PRELIM:
2610 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
2612 - SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
2613 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM,
2614 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM:
2615 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
2617 - CONFIG_SYS_MAMR_PTA, CONFIG_SYS_MPTPR_2BK_4K, CONFIG_SYS_MPTPR_1BK_4K, CONFIG_SYS_MPTPR_2BK_8K,
2618 CONFIG_SYS_MPTPR_1BK_8K, CONFIG_SYS_MAMR_8COL, CONFIG_SYS_MAMR_9COL:
2619 Machine Mode Register and Memory Periodic Timer
2620 Prescaler definitions (SDRAM timing)
2622 - CONFIG_SYS_I2C_UCODE_PATCH, CONFIG_SYS_I2C_DPMEM_OFFSET [0x1FC0]:
2623 enable I2C microcode relocation patch (MPC8xx);
2624 define relocation offset in DPRAM [DSP2]
2626 - CONFIG_SYS_SMC_UCODE_PATCH, CONFIG_SYS_SMC_DPMEM_OFFSET [0x1FC0]:
2627 enable SMC microcode relocation patch (MPC8xx);
2628 define relocation offset in DPRAM [SMC1]
2630 - CONFIG_SYS_SPI_UCODE_PATCH, CONFIG_SYS_SPI_DPMEM_OFFSET [0x1FC0]:
2631 enable SPI microcode relocation patch (MPC8xx);
2632 define relocation offset in DPRAM [SCC4]
2634 - CONFIG_SYS_USE_OSCCLK:
2635 Use OSCM clock mode on MBX8xx board. Be careful,
2636 wrong setting might damage your board. Read
2637 doc/README.MBX before setting this variable!
2639 - CONFIG_SYS_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only)
2640 Offset of the bootmode word in DPRAM used by post
2641 (Power On Self Tests). This definition overrides
2642 #define'd default value in commproc.h resp.
2645 - CONFIG_SYS_PCI_SLV_MEM_LOCAL, CONFIG_SYS_PCI_SLV_MEM_BUS, CONFIG_SYS_PICMR0_MASK_ATTRIB,
2646 CONFIG_SYS_PCI_MSTR0_LOCAL, CONFIG_SYS_PCIMSK0_MASK, CONFIG_SYS_PCI_MSTR1_LOCAL,
2647 CONFIG_SYS_PCIMSK1_MASK, CONFIG_SYS_PCI_MSTR_MEM_LOCAL, CONFIG_SYS_PCI_MSTR_MEM_BUS,
2648 CONFIG_SYS_CPU_PCI_MEM_START, CONFIG_SYS_PCI_MSTR_MEM_SIZE, CONFIG_SYS_POCMR0_MASK_ATTRIB,
2649 CONFIG_SYS_PCI_MSTR_MEMIO_LOCAL, CONFIG_SYS_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START,
2650 CONFIG_SYS_PCI_MSTR_MEMIO_SIZE, CONFIG_SYS_POCMR1_MASK_ATTRIB, CONFIG_SYS_PCI_MSTR_IO_LOCAL,
2651 CONFIG_SYS_PCI_MSTR_IO_BUS, CONFIG_SYS_CPU_PCI_IO_START, CONFIG_SYS_PCI_MSTR_IO_SIZE,
2652 CONFIG_SYS_POCMR2_MASK_ATTRIB: (MPC826x only)
2653 Overrides the default PCI memory map in cpu/mpc8260/pci.c if set.
2655 - CONFIG_PCI_DISABLE_PCIE:
2656 Disable PCI-Express on systems where it is supported but not
2660 Get DDR timing information from an I2C EEPROM. Common
2661 with pluggable memory modules such as SODIMMs
2664 I2C address of the SPD EEPROM
2666 - CONFIG_SYS_SPD_BUS_NUM
2667 If SPD EEPROM is on an I2C bus other than the first
2668 one, specify here. Note that the value must resolve
2669 to something your driver can deal with.
2671 - CONFIG_SYS_83XX_DDR_USES_CS0
2672 Only for 83xx systems. If specified, then DDR should
2673 be configured using CS0 and CS1 instead of CS2 and CS3.
2675 - CONFIG_ETHER_ON_FEC[12]
2676 Define to enable FEC[12] on a 8xx series processor.
2678 - CONFIG_FEC[12]_PHY
2679 Define to the hardcoded PHY address which corresponds
2680 to the given FEC; i. e.
2681 #define CONFIG_FEC1_PHY 4
2682 means that the PHY with address 4 is connected to FEC1
2684 When set to -1, means to probe for first available.
2686 - CONFIG_FEC[12]_PHY_NORXERR
2687 The PHY does not have a RXERR line (RMII only).
2688 (so program the FEC to ignore it).
2691 Enable RMII mode for all FECs.
2692 Note that this is a global option, we can't
2693 have one FEC in standard MII mode and another in RMII mode.
2695 - CONFIG_CRC32_VERIFY
2696 Add a verify option to the crc32 command.
2699 => crc32 -v <address> <count> <crc32>
2701 Where address/count indicate a memory area
2702 and crc32 is the correct crc32 which the
2706 Add the "loopw" memory command. This only takes effect if
2707 the memory commands are activated globally (CONFIG_CMD_MEM).
2710 Add the "mdc" and "mwc" memory commands. These are cyclic
2715 This command will print 4 bytes (10,11,12,13) each 500 ms.
2717 => mwc.l 100 12345678 10
2718 This command will write 12345678 to address 100 all 10 ms.
2720 This only takes effect if the memory commands are activated
2721 globally (CONFIG_CMD_MEM).
2723 - CONFIG_SKIP_LOWLEVEL_INIT
2724 - CONFIG_SKIP_RELOCATE_UBOOT
2726 [ARM only] If these variables are defined, then
2727 certain low level initializations (like setting up
2728 the memory controller) are omitted and/or U-Boot does
2729 not relocate itself into RAM.
2730 Normally these variables MUST NOT be defined. The
2731 only exception is when U-Boot is loaded (to RAM) by
2732 some other boot loader or by a debugger which
2733 performs these initializations itself.
2737 Modifies the behaviour of start.S when compiling a loader
2738 that is executed before the actual U-Boot. E.g. when
2739 compiling a NAND SPL.
2741 Building the Software:
2742 ======================
2744 Building U-Boot has been tested in several native build environments
2745 and in many different cross environments. Of course we cannot support
2746 all possibly existing versions of cross development tools in all
2747 (potentially obsolete) versions. In case of tool chain problems we
2748 recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK)
2749 which is extensively used to build and test U-Boot.
2751 If you are not using a native environment, it is assumed that you
2752 have GNU cross compiling tools available in your path. In this case,
2753 you must set the environment variable CROSS_COMPILE in your shell.
2754 Note that no changes to the Makefile or any other source files are
2755 necessary. For example using the ELDK on a 4xx CPU, please enter:
2757 $ CROSS_COMPILE=ppc_4xx-
2758 $ export CROSS_COMPILE
2760 Note: If you wish to generate Windows versions of the utilities in
2761 the tools directory you can use the MinGW toolchain
2762 (http://www.mingw.org). Set your HOST tools to the MinGW
2763 toolchain and execute 'make tools'. For example:
2765 $ make HOSTCC=i586-mingw32msvc-gcc HOSTSTRIP=i586-mingw32msvc-strip tools
2767 Binaries such as tools/mkimage.exe will be created which can
2768 be executed on computers running Windows.
2770 U-Boot is intended to be simple to build. After installing the
2771 sources you must configure U-Boot for one specific board type. This
2776 where "NAME_config" is the name of one of the existing configu-
2777 rations; see the main Makefile for supported names.
2779 Note: for some board special configuration names may exist; check if
2780 additional information is available from the board vendor; for
2781 instance, the TQM823L systems are available without (standard)
2782 or with LCD support. You can select such additional "features"
2783 when choosing the configuration, i. e.
2786 - will configure for a plain TQM823L, i. e. no LCD support
2788 make TQM823L_LCD_config
2789 - will configure for a TQM823L with U-Boot console on LCD
2794 Finally, type "make all", and you should get some working U-Boot
2795 images ready for download to / installation on your system:
2797 - "u-boot.bin" is a raw binary image
2798 - "u-boot" is an image in ELF binary format
2799 - "u-boot.srec" is in Motorola S-Record format
2801 By default the build is performed locally and the objects are saved
2802 in the source directory. One of the two methods can be used to change
2803 this behavior and build U-Boot to some external directory:
2805 1. Add O= to the make command line invocations:
2807 make O=/tmp/build distclean
2808 make O=/tmp/build NAME_config
2809 make O=/tmp/build all
2811 2. Set environment variable BUILD_DIR to point to the desired location:
2813 export BUILD_DIR=/tmp/build
2818 Note that the command line "O=" setting overrides the BUILD_DIR environment
2822 Please be aware that the Makefiles assume you are using GNU make, so
2823 for instance on NetBSD you might need to use "gmake" instead of
2827 If the system board that you have is not listed, then you will need
2828 to port U-Boot to your hardware platform. To do this, follow these
2831 1. Add a new configuration option for your board to the toplevel
2832 "Makefile" and to the "MAKEALL" script, using the existing
2833 entries as examples. Note that here and at many other places
2834 boards and other names are listed in alphabetical sort order. Please
2836 2. Create a new directory to hold your board specific code. Add any
2837 files you need. In your board directory, you will need at least
2838 the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds".
2839 3. Create a new configuration file "include/configs/<board>.h" for
2841 3. If you're porting U-Boot to a new CPU, then also create a new
2842 directory to hold your CPU specific code. Add any files you need.
2843 4. Run "make <board>_config" with your new name.
2844 5. Type "make", and you should get a working "u-boot.srec" file
2845 to be installed on your target system.
2846 6. Debug and solve any problems that might arise.
2847 [Of course, this last step is much harder than it sounds.]
2850 Testing of U-Boot Modifications, Ports to New Hardware, etc.:
2851 ==============================================================
2853 If you have modified U-Boot sources (for instance added a new board
2854 or support for new devices, a new CPU, etc.) you are expected to
2855 provide feedback to the other developers. The feedback normally takes
2856 the form of a "patch", i. e. a context diff against a certain (latest
2857 official or latest in the git repository) version of U-Boot sources.
2859 But before you submit such a patch, please verify that your modifi-
2860 cation did not break existing code. At least make sure that *ALL* of
2861 the supported boards compile WITHOUT ANY compiler warnings. To do so,
2862 just run the "MAKEALL" script, which will configure and build U-Boot
2863 for ALL supported system. Be warned, this will take a while. You can
2864 select which (cross) compiler to use by passing a `CROSS_COMPILE'
2865 environment variable to the script, i. e. to use the ELDK cross tools
2868 CROSS_COMPILE=ppc_8xx- MAKEALL
2870 or to build on a native PowerPC system you can type
2872 CROSS_COMPILE=' ' MAKEALL
2874 When using the MAKEALL script, the default behaviour is to build
2875 U-Boot in the source directory. This location can be changed by
2876 setting the BUILD_DIR environment variable. Also, for each target
2877 built, the MAKEALL script saves two log files (<target>.ERR and
2878 <target>.MAKEALL) in the <source dir>/LOG directory. This default
2879 location can be changed by setting the MAKEALL_LOGDIR environment
2880 variable. For example:
2882 export BUILD_DIR=/tmp/build
2883 export MAKEALL_LOGDIR=/tmp/log
2884 CROSS_COMPILE=ppc_8xx- MAKEALL
2886 With the above settings build objects are saved in the /tmp/build,
2887 log files are saved in the /tmp/log and the source tree remains clean
2888 during the whole build process.
2891 See also "U-Boot Porting Guide" below.
2894 Monitor Commands - Overview:
2895 ============================
2897 go - start application at address 'addr'
2898 run - run commands in an environment variable
2899 bootm - boot application image from memory
2900 bootp - boot image via network using BootP/TFTP protocol
2901 tftpboot- boot image via network using TFTP protocol
2902 and env variables "ipaddr" and "serverip"
2903 (and eventually "gatewayip")
2904 rarpboot- boot image via network using RARP/TFTP protocol
2905 diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
2906 loads - load S-Record file over serial line
2907 loadb - load binary file over serial line (kermit mode)
2909 mm - memory modify (auto-incrementing)
2910 nm - memory modify (constant address)
2911 mw - memory write (fill)
2913 cmp - memory compare
2914 crc32 - checksum calculation
2915 i2c - I2C sub-system
2916 sspi - SPI utility commands
2917 base - print or set address offset
2918 printenv- print environment variables
2919 setenv - set environment variables
2920 saveenv - save environment variables to persistent storage
2921 protect - enable or disable FLASH write protection
2922 erase - erase FLASH memory
2923 flinfo - print FLASH memory information
2924 bdinfo - print Board Info structure
2925 iminfo - print header information for application image
2926 coninfo - print console devices and informations
2927 ide - IDE sub-system
2928 loop - infinite loop on address range
2929 loopw - infinite write loop on address range
2930 mtest - simple RAM test
2931 icache - enable or disable instruction cache
2932 dcache - enable or disable data cache
2933 reset - Perform RESET of the CPU
2934 echo - echo args to console
2935 version - print monitor version
2936 help - print online help
2937 ? - alias for 'help'
2940 Monitor Commands - Detailed Description:
2941 ========================================
2945 For now: just type "help <command>".
2948 Environment Variables:
2949 ======================
2951 U-Boot supports user configuration using Environment Variables which
2952 can be made persistent by saving to Flash memory.
2954 Environment Variables are set using "setenv", printed using
2955 "printenv", and saved to Flash using "saveenv". Using "setenv"
2956 without a value can be used to delete a variable from the
2957 environment. As long as you don't save the environment you are
2958 working with an in-memory copy. In case the Flash area containing the
2959 environment is erased by accident, a default environment is provided.
2961 Some configuration options can be set using Environment Variables:
2963 baudrate - see CONFIG_BAUDRATE
2965 bootdelay - see CONFIG_BOOTDELAY
2967 bootcmd - see CONFIG_BOOTCOMMAND
2969 bootargs - Boot arguments when booting an RTOS image
2971 bootfile - Name of the image to load with TFTP
2973 bootm_low - Memory range available for image processing in the bootm
2974 command can be restricted. This variable is given as
2975 a hexadecimal number and defines lowest address allowed
2976 for use by the bootm command. See also "bootm_size"
2977 environment variable. Address defined by "bootm_low" is
2978 also the base of the initial memory mapping for the Linux
2979 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ.
2981 bootm_size - Memory range available for image processing in the bootm
2982 command can be restricted. This variable is given as
2983 a hexadecimal number and defines the size of the region
2984 allowed for use by the bootm command. See also "bootm_low"
2985 environment variable.
2987 updatefile - Location of the software update file on a TFTP server, used
2988 by the automatic software update feature. Please refer to
2989 documentation in doc/README.update for more details.
2991 autoload - if set to "no" (any string beginning with 'n'),
2992 "bootp" will just load perform a lookup of the
2993 configuration from the BOOTP server, but not try to
2994 load any image using TFTP
2996 autoscript - if set to "yes" commands like "loadb", "loady",
2997 "bootp", "tftpb", "rarpboot" and "nfs" will attempt
2998 to automatically run script images (by internally
3001 autoscript_uname - if script image is in a format (FIT) this
3002 variable is used to get script subimage unit name.
3004 autostart - if set to "yes", an image loaded using the "bootp",
3005 "rarpboot", "tftpboot" or "diskboot" commands will
3006 be automatically started (by internally calling
3009 If set to "no", a standalone image passed to the
3010 "bootm" command will be copied to the load address
3011 (and eventually uncompressed), but NOT be started.
3012 This can be used to load and uncompress arbitrary
3015 i2cfast - (PPC405GP|PPC405EP only)
3016 if set to 'y' configures Linux I2C driver for fast
3017 mode (400kHZ). This environment variable is used in
3018 initialization code. So, for changes to be effective
3019 it must be saved and board must be reset.
3021 initrd_high - restrict positioning of initrd images:
3022 If this variable is not set, initrd images will be
3023 copied to the highest possible address in RAM; this
3024 is usually what you want since it allows for
3025 maximum initrd size. If for some reason you want to
3026 make sure that the initrd image is loaded below the
3027 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment
3028 variable to a value of "no" or "off" or "0".
3029 Alternatively, you can set it to a maximum upper
3030 address to use (U-Boot will still check that it
3031 does not overwrite the U-Boot stack and data).
3033 For instance, when you have a system with 16 MB
3034 RAM, and want to reserve 4 MB from use by Linux,
3035 you can do this by adding "mem=12M" to the value of
3036 the "bootargs" variable. However, now you must make
3037 sure that the initrd image is placed in the first
3038 12 MB as well - this can be done with
3040 setenv initrd_high 00c00000
3042 If you set initrd_high to 0xFFFFFFFF, this is an
3043 indication to U-Boot that all addresses are legal
3044 for the Linux kernel, including addresses in flash
3045 memory. In this case U-Boot will NOT COPY the
3046 ramdisk at all. This may be useful to reduce the
3047 boot time on your system, but requires that this
3048 feature is supported by your Linux kernel.
3050 ipaddr - IP address; needed for tftpboot command
3052 loadaddr - Default load address for commands like "bootp",
3053 "rarpboot", "tftpboot", "loadb" or "diskboot"
3055 loads_echo - see CONFIG_LOADS_ECHO
3057 serverip - TFTP server IP address; needed for tftpboot command
3059 bootretry - see CONFIG_BOOT_RETRY_TIME
3061 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
3063 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
3065 ethprime - When CONFIG_NET_MULTI is enabled controls which
3066 interface is used first.
3068 ethact - When CONFIG_NET_MULTI is enabled controls which
3069 interface is currently active. For example you
3070 can do the following
3072 => setenv ethact FEC ETHERNET
3073 => ping 192.168.0.1 # traffic sent on FEC ETHERNET
3074 => setenv ethact SCC ETHERNET
3075 => ping 10.0.0.1 # traffic sent on SCC ETHERNET
3077 ethrotate - When set to "no" U-Boot does not go through all
3078 available network interfaces.
3079 It just stays at the currently selected interface.
3081 netretry - When set to "no" each network operation will
3082 either succeed or fail without retrying.
3083 When set to "once" the network operation will
3084 fail when all the available network interfaces
3085 are tried once without success.
3086 Useful on scripts which control the retry operation
3089 npe_ucode - set load address for the NPE microcode
3091 tftpsrcport - If this is set, the value is used for TFTP's
3094 tftpdstport - If this is set, the value is used for TFTP's UDP
3095 destination port instead of the Well Know Port 69.
3097 vlan - When set to a value < 4095 the traffic over
3098 Ethernet is encapsulated/received over 802.1q
3101 The following environment variables may be used and automatically
3102 updated by the network boot commands ("bootp" and "rarpboot"),
3103 depending the information provided by your boot server:
3105 bootfile - see above
3106 dnsip - IP address of your Domain Name Server
3107 dnsip2 - IP address of your secondary Domain Name Server
3108 gatewayip - IP address of the Gateway (Router) to use
3109 hostname - Target hostname
3111 netmask - Subnet Mask
3112 rootpath - Pathname of the root filesystem on the NFS server
3113 serverip - see above
3116 There are two special Environment Variables:
3118 serial# - contains hardware identification information such
3119 as type string and/or serial number
3120 ethaddr - Ethernet address
3122 These variables can be set only once (usually during manufacturing of
3123 the board). U-Boot refuses to delete or overwrite these variables
3124 once they have been set once.
3127 Further special Environment Variables:
3129 ver - Contains the U-Boot version string as printed
3130 with the "version" command. This variable is
3131 readonly (see CONFIG_VERSION_VARIABLE).
3134 Please note that changes to some configuration parameters may take
3135 only effect after the next boot (yes, that's just like Windoze :-).
3138 Command Line Parsing:
3139 =====================
3141 There are two different command line parsers available with U-Boot:
3142 the old "simple" one, and the much more powerful "hush" shell:
3144 Old, simple command line parser:
3145 --------------------------------
3147 - supports environment variables (through setenv / saveenv commands)
3148 - several commands on one line, separated by ';'
3149 - variable substitution using "... ${name} ..." syntax
3150 - special characters ('$', ';') can be escaped by prefixing with '\',
3152 setenv bootcmd bootm \${address}
3153 - You can also escape text by enclosing in single apostrophes, for example:
3154 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
3159 - similar to Bourne shell, with control structures like
3160 if...then...else...fi, for...do...done; while...do...done,
3161 until...do...done, ...
3162 - supports environment ("global") variables (through setenv / saveenv
3163 commands) and local shell variables (through standard shell syntax
3164 "name=value"); only environment variables can be used with "run"
3170 (1) If a command line (or an environment variable executed by a "run"
3171 command) contains several commands separated by semicolon, and
3172 one of these commands fails, then the remaining commands will be
3175 (2) If you execute several variables with one call to run (i. e.
3176 calling run with a list of variables as arguments), any failing
3177 command will cause "run" to terminate, i. e. the remaining
3178 variables are not executed.
3180 Note for Redundant Ethernet Interfaces:
3181 =======================================
3183 Some boards come with redundant Ethernet interfaces; U-Boot supports
3184 such configurations and is capable of automatic selection of a
3185 "working" interface when needed. MAC assignment works as follows:
3187 Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
3188 MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
3189 "eth1addr" (=>eth1), "eth2addr", ...
3191 If the network interface stores some valid MAC address (for instance
3192 in SROM), this is used as default address if there is NO correspon-
3193 ding setting in the environment; if the corresponding environment
3194 variable is set, this overrides the settings in the card; that means:
3196 o If the SROM has a valid MAC address, and there is no address in the
3197 environment, the SROM's address is used.
3199 o If there is no valid address in the SROM, and a definition in the
3200 environment exists, then the value from the environment variable is
3203 o If both the SROM and the environment contain a MAC address, and
3204 both addresses are the same, this MAC address is used.
3206 o If both the SROM and the environment contain a MAC address, and the
3207 addresses differ, the value from the environment is used and a
3210 o If neither SROM nor the environment contain a MAC address, an error
3217 U-Boot is capable of booting (and performing other auxiliary operations on)
3218 images in two formats:
3220 New uImage format (FIT)
3221 -----------------------
3223 Flexible and powerful format based on Flattened Image Tree -- FIT (similar
3224 to Flattened Device Tree). It allows the use of images with multiple
3225 components (several kernels, ramdisks, etc.), with contents protected by
3226 SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory.
3232 Old image format is based on binary files which can be basically anything,
3233 preceded by a special header; see the definitions in include/image.h for
3234 details; basically, the header defines the following image properties:
3236 * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
3237 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
3238 LynxOS, pSOS, QNX, RTEMS, INTEGRITY;
3239 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS,
3241 * Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86,
3242 IA64, MIPS, NIOS, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
3243 Currently supported: ARM, AVR32, Intel x86, MIPS, NIOS, PowerPC).
3244 * Compression Type (uncompressed, gzip, bzip2)
3250 The header is marked by a special Magic Number, and both the header
3251 and the data portions of the image are secured against corruption by
3258 Although U-Boot should support any OS or standalone application
3259 easily, the main focus has always been on Linux during the design of
3262 U-Boot includes many features that so far have been part of some
3263 special "boot loader" code within the Linux kernel. Also, any
3264 "initrd" images to be used are no longer part of one big Linux image;
3265 instead, kernel and "initrd" are separate images. This implementation
3266 serves several purposes:
3268 - the same features can be used for other OS or standalone
3269 applications (for instance: using compressed images to reduce the
3270 Flash memory footprint)
3272 - it becomes much easier to port new Linux kernel versions because
3273 lots of low-level, hardware dependent stuff are done by U-Boot
3275 - the same Linux kernel image can now be used with different "initrd"
3276 images; of course this also means that different kernel images can
3277 be run with the same "initrd". This makes testing easier (you don't
3278 have to build a new "zImage.initrd" Linux image when you just
3279 change a file in your "initrd"). Also, a field-upgrade of the
3280 software is easier now.
3286 Porting Linux to U-Boot based systems:
3287 ---------------------------------------
3289 U-Boot cannot save you from doing all the necessary modifications to
3290 configure the Linux device drivers for use with your target hardware
3291 (no, we don't intend to provide a full virtual machine interface to
3294 But now you can ignore ALL boot loader code (in arch/ppc/mbxboot).
3296 Just make sure your machine specific header file (for instance
3297 include/asm-ppc/tqm8xx.h) includes the same definition of the Board
3298 Information structure as we define in include/asm-<arch>/u-boot.h,
3299 and make sure that your definition of IMAP_ADDR uses the same value
3300 as your U-Boot configuration in CONFIG_SYS_IMMR.
3303 Configuring the Linux kernel:
3304 -----------------------------
3306 No specific requirements for U-Boot. Make sure you have some root
3307 device (initial ramdisk, NFS) for your target system.
3310 Building a Linux Image:
3311 -----------------------
3313 With U-Boot, "normal" build targets like "zImage" or "bzImage" are
3314 not used. If you use recent kernel source, a new build target
3315 "uImage" will exist which automatically builds an image usable by
3316 U-Boot. Most older kernels also have support for a "pImage" target,
3317 which was introduced for our predecessor project PPCBoot and uses a
3318 100% compatible format.
3327 The "uImage" build target uses a special tool (in 'tools/mkimage') to
3328 encapsulate a compressed Linux kernel image with header information,
3329 CRC32 checksum etc. for use with U-Boot. This is what we are doing:
3331 * build a standard "vmlinux" kernel image (in ELF binary format):
3333 * convert the kernel into a raw binary image:
3335 ${CROSS_COMPILE}-objcopy -O binary \
3336 -R .note -R .comment \
3337 -S vmlinux linux.bin
3339 * compress the binary image:
3343 * package compressed binary image for U-Boot:
3345 mkimage -A ppc -O linux -T kernel -C gzip \
3346 -a 0 -e 0 -n "Linux Kernel Image" \
3347 -d linux.bin.gz uImage
3350 The "mkimage" tool can also be used to create ramdisk images for use
3351 with U-Boot, either separated from the Linux kernel image, or
3352 combined into one file. "mkimage" encapsulates the images with a 64
3353 byte header containing information about target architecture,
3354 operating system, image type, compression method, entry points, time
3355 stamp, CRC32 checksums, etc.
3357 "mkimage" can be called in two ways: to verify existing images and
3358 print the header information, or to build new images.
3360 In the first form (with "-l" option) mkimage lists the information
3361 contained in the header of an existing U-Boot image; this includes
3362 checksum verification:
3364 tools/mkimage -l image
3365 -l ==> list image header information
3367 The second form (with "-d" option) is used to build a U-Boot image
3368 from a "data file" which is used as image payload:
3370 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
3371 -n name -d data_file image
3372 -A ==> set architecture to 'arch'
3373 -O ==> set operating system to 'os'
3374 -T ==> set image type to 'type'
3375 -C ==> set compression type 'comp'
3376 -a ==> set load address to 'addr' (hex)
3377 -e ==> set entry point to 'ep' (hex)
3378 -n ==> set image name to 'name'
3379 -d ==> use image data from 'datafile'
3381 Right now, all Linux kernels for PowerPC systems use the same load
3382 address (0x00000000), but the entry point address depends on the
3385 - 2.2.x kernels have the entry point at 0x0000000C,
3386 - 2.3.x and later kernels have the entry point at 0x00000000.
3388 So a typical call to build a U-Boot image would read:
3390 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
3391 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
3392 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux.gz \
3393 > examples/uImage.TQM850L
3394 Image Name: 2.4.4 kernel for TQM850L
3395 Created: Wed Jul 19 02:34:59 2000
3396 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3397 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
3398 Load Address: 0x00000000
3399 Entry Point: 0x00000000
3401 To verify the contents of the image (or check for corruption):
3403 -> tools/mkimage -l examples/uImage.TQM850L
3404 Image Name: 2.4.4 kernel for TQM850L
3405 Created: Wed Jul 19 02:34:59 2000
3406 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3407 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
3408 Load Address: 0x00000000
3409 Entry Point: 0x00000000
3411 NOTE: for embedded systems where boot time is critical you can trade
3412 speed for memory and install an UNCOMPRESSED image instead: this
3413 needs more space in Flash, but boots much faster since it does not
3414 need to be uncompressed:
3416 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux.gz
3417 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
3418 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
3419 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux \
3420 > examples/uImage.TQM850L-uncompressed
3421 Image Name: 2.4.4 kernel for TQM850L
3422 Created: Wed Jul 19 02:34:59 2000
3423 Image Type: PowerPC Linux Kernel Image (uncompressed)
3424 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
3425 Load Address: 0x00000000
3426 Entry Point: 0x00000000
3429 Similar you can build U-Boot images from a 'ramdisk.image.gz' file
3430 when your kernel is intended to use an initial ramdisk:
3432 -> tools/mkimage -n 'Simple Ramdisk Image' \
3433 > -A ppc -O linux -T ramdisk -C gzip \
3434 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
3435 Image Name: Simple Ramdisk Image
3436 Created: Wed Jan 12 14:01:50 2000
3437 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
3438 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
3439 Load Address: 0x00000000
3440 Entry Point: 0x00000000
3443 Installing a Linux Image:
3444 -------------------------
3446 To downloading a U-Boot image over the serial (console) interface,
3447 you must convert the image to S-Record format:
3449 objcopy -I binary -O srec examples/image examples/image.srec
3451 The 'objcopy' does not understand the information in the U-Boot
3452 image header, so the resulting S-Record file will be relative to
3453 address 0x00000000. To load it to a given address, you need to
3454 specify the target address as 'offset' parameter with the 'loads'
3457 Example: install the image to address 0x40100000 (which on the
3458 TQM8xxL is in the first Flash bank):
3460 => erase 40100000 401FFFFF
3466 ## Ready for S-Record download ...
3467 ~>examples/image.srec
3468 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
3470 15989 15990 15991 15992
3471 [file transfer complete]
3473 ## Start Addr = 0x00000000
3476 You can check the success of the download using the 'iminfo' command;
3477 this includes a checksum verification so you can be sure no data
3478 corruption happened:
3482 ## Checking Image at 40100000 ...
3483 Image Name: 2.2.13 for initrd on TQM850L
3484 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3485 Data Size: 335725 Bytes = 327 kB = 0 MB
3486 Load Address: 00000000
3487 Entry Point: 0000000c
3488 Verifying Checksum ... OK
3494 The "bootm" command is used to boot an application that is stored in
3495 memory (RAM or Flash). In case of a Linux kernel image, the contents
3496 of the "bootargs" environment variable is passed to the kernel as
3497 parameters. You can check and modify this variable using the
3498 "printenv" and "setenv" commands:
3501 => printenv bootargs
3502 bootargs=root=/dev/ram
3504 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
3506 => printenv bootargs
3507 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
3510 ## Booting Linux kernel at 40020000 ...
3511 Image Name: 2.2.13 for NFS on TQM850L
3512 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3513 Data Size: 381681 Bytes = 372 kB = 0 MB
3514 Load Address: 00000000
3515 Entry Point: 0000000c
3516 Verifying Checksum ... OK
3517 Uncompressing Kernel Image ... OK
3518 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
3519 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
3520 time_init: decrementer frequency = 187500000/60
3521 Calibrating delay loop... 49.77 BogoMIPS
3522 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
3525 If you want to boot a Linux kernel with initial RAM disk, you pass
3526 the memory addresses of both the kernel and the initrd image (PPBCOOT
3527 format!) to the "bootm" command:
3529 => imi 40100000 40200000
3531 ## Checking Image at 40100000 ...
3532 Image Name: 2.2.13 for initrd on TQM850L
3533 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3534 Data Size: 335725 Bytes = 327 kB = 0 MB
3535 Load Address: 00000000
3536 Entry Point: 0000000c
3537 Verifying Checksum ... OK
3539 ## Checking Image at 40200000 ...
3540 Image Name: Simple Ramdisk Image
3541 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
3542 Data Size: 566530 Bytes = 553 kB = 0 MB
3543 Load Address: 00000000
3544 Entry Point: 00000000
3545 Verifying Checksum ... OK
3547 => bootm 40100000 40200000
3548 ## Booting Linux kernel at 40100000 ...
3549 Image Name: 2.2.13 for initrd on TQM850L
3550 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3551 Data Size: 335725 Bytes = 327 kB = 0 MB
3552 Load Address: 00000000
3553 Entry Point: 0000000c
3554 Verifying Checksum ... OK
3555 Uncompressing Kernel Image ... OK
3556 ## Loading RAMDisk Image at 40200000 ...
3557 Image Name: Simple Ramdisk Image
3558 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
3559 Data Size: 566530 Bytes = 553 kB = 0 MB
3560 Load Address: 00000000
3561 Entry Point: 00000000
3562 Verifying Checksum ... OK
3563 Loading Ramdisk ... OK
3564 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
3565 Boot arguments: root=/dev/ram
3566 time_init: decrementer frequency = 187500000/60
3567 Calibrating delay loop... 49.77 BogoMIPS
3569 RAMDISK: Compressed image found at block 0
3570 VFS: Mounted root (ext2 filesystem).
3574 Boot Linux and pass a flat device tree:
3577 First, U-Boot must be compiled with the appropriate defines. See the section
3578 titled "Linux Kernel Interface" above for a more in depth explanation. The
3579 following is an example of how to start a kernel and pass an updated
3585 oft=oftrees/mpc8540ads.dtb
3586 => tftp $oftaddr $oft
3587 Speed: 1000, full duplex
3589 TFTP from server 192.168.1.1; our IP address is 192.168.1.101
3590 Filename 'oftrees/mpc8540ads.dtb'.
3591 Load address: 0x300000
3594 Bytes transferred = 4106 (100a hex)
3595 => tftp $loadaddr $bootfile
3596 Speed: 1000, full duplex
3598 TFTP from server 192.168.1.1; our IP address is 192.168.1.2
3600 Load address: 0x200000
3601 Loading:############
3603 Bytes transferred = 1029407 (fb51f hex)
3608 => bootm $loadaddr - $oftaddr
3609 ## Booting image at 00200000 ...
3610 Image Name: Linux-2.6.17-dirty
3611 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3612 Data Size: 1029343 Bytes = 1005.2 kB
3613 Load Address: 00000000
3614 Entry Point: 00000000
3615 Verifying Checksum ... OK
3616 Uncompressing Kernel Image ... OK
3617 Booting using flat device tree at 0x300000
3618 Using MPC85xx ADS machine description
3619 Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb
3623 More About U-Boot Image Types:
3624 ------------------------------
3626 U-Boot supports the following image types:
3628 "Standalone Programs" are directly runnable in the environment
3629 provided by U-Boot; it is expected that (if they behave
3630 well) you can continue to work in U-Boot after return from
3631 the Standalone Program.
3632 "OS Kernel Images" are usually images of some Embedded OS which
3633 will take over control completely. Usually these programs
3634 will install their own set of exception handlers, device
3635 drivers, set up the MMU, etc. - this means, that you cannot
3636 expect to re-enter U-Boot except by resetting the CPU.
3637 "RAMDisk Images" are more or less just data blocks, and their
3638 parameters (address, size) are passed to an OS kernel that is
3640 "Multi-File Images" contain several images, typically an OS
3641 (Linux) kernel image and one or more data images like
3642 RAMDisks. This construct is useful for instance when you want
3643 to boot over the network using BOOTP etc., where the boot
3644 server provides just a single image file, but you want to get
3645 for instance an OS kernel and a RAMDisk image.
3647 "Multi-File Images" start with a list of image sizes, each
3648 image size (in bytes) specified by an "uint32_t" in network
3649 byte order. This list is terminated by an "(uint32_t)0".
3650 Immediately after the terminating 0 follow the images, one by
3651 one, all aligned on "uint32_t" boundaries (size rounded up to
3652 a multiple of 4 bytes).
3654 "Firmware Images" are binary images containing firmware (like
3655 U-Boot or FPGA images) which usually will be programmed to
3658 "Script files" are command sequences that will be executed by
3659 U-Boot's command interpreter; this feature is especially
3660 useful when you configure U-Boot to use a real shell (hush)
3661 as command interpreter.
3667 One of the features of U-Boot is that you can dynamically load and
3668 run "standalone" applications, which can use some resources of
3669 U-Boot like console I/O functions or interrupt services.
3671 Two simple examples are included with the sources:
3676 'examples/hello_world.c' contains a small "Hello World" Demo
3677 application; it is automatically compiled when you build U-Boot.
3678 It's configured to run at address 0x00040004, so you can play with it
3682 ## Ready for S-Record download ...
3683 ~>examples/hello_world.srec
3684 1 2 3 4 5 6 7 8 9 10 11 ...
3685 [file transfer complete]
3687 ## Start Addr = 0x00040004
3689 => go 40004 Hello World! This is a test.
3690 ## Starting application at 0x00040004 ...
3701 Hit any key to exit ...
3703 ## Application terminated, rc = 0x0
3705 Another example, which demonstrates how to register a CPM interrupt
3706 handler with the U-Boot code, can be found in 'examples/timer.c'.
3707 Here, a CPM timer is set up to generate an interrupt every second.
3708 The interrupt service routine is trivial, just printing a '.'
3709 character, but this is just a demo program. The application can be
3710 controlled by the following keys:
3712 ? - print current values og the CPM Timer registers
3713 b - enable interrupts and start timer
3714 e - stop timer and disable interrupts
3715 q - quit application
3718 ## Ready for S-Record download ...
3719 ~>examples/timer.srec
3720 1 2 3 4 5 6 7 8 9 10 11 ...
3721 [file transfer complete]
3723 ## Start Addr = 0x00040004
3726 ## Starting application at 0x00040004 ...
3729 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
3732 [q, b, e, ?] Set interval 1000000 us
3735 [q, b, e, ?] ........
3736 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
3739 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
3742 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
3745 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
3747 [q, b, e, ?] ...Stopping timer
3749 [q, b, e, ?] ## Application terminated, rc = 0x0
3755 Over time, many people have reported problems when trying to use the
3756 "minicom" terminal emulation program for serial download. I (wd)
3757 consider minicom to be broken, and recommend not to use it. Under
3758 Unix, I recommend to use C-Kermit for general purpose use (and
3759 especially for kermit binary protocol download ("loadb" command), and
3760 use "cu" for S-Record download ("loads" command).
3762 Nevertheless, if you absolutely want to use it try adding this
3763 configuration to your "File transfer protocols" section:
3765 Name Program Name U/D FullScr IO-Red. Multi
3766 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
3767 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
3773 Starting at version 0.9.2, U-Boot supports NetBSD both as host
3774 (build U-Boot) and target system (boots NetBSD/mpc8xx).
3776 Building requires a cross environment; it is known to work on
3777 NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
3778 need gmake since the Makefiles are not compatible with BSD make).
3779 Note that the cross-powerpc package does not install include files;
3780 attempting to build U-Boot will fail because <machine/ansi.h> is
3781 missing. This file has to be installed and patched manually:
3783 # cd /usr/pkg/cross/powerpc-netbsd/include
3785 # ln -s powerpc machine
3786 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
3787 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
3789 Native builds *don't* work due to incompatibilities between native
3790 and U-Boot include files.
3792 Booting assumes that (the first part of) the image booted is a
3793 stage-2 loader which in turn loads and then invokes the kernel
3794 proper. Loader sources will eventually appear in the NetBSD source
3795 tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
3796 meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz
3799 Implementation Internals:
3800 =========================
3802 The following is not intended to be a complete description of every
3803 implementation detail. However, it should help to understand the
3804 inner workings of U-Boot and make it easier to port it to custom
3808 Initial Stack, Global Data:
3809 ---------------------------
3811 The implementation of U-Boot is complicated by the fact that U-Boot
3812 starts running out of ROM (flash memory), usually without access to
3813 system RAM (because the memory controller is not initialized yet).
3814 This means that we don't have writable Data or BSS segments, and BSS
3815 is not initialized as zero. To be able to get a C environment working
3816 at all, we have to allocate at least a minimal stack. Implementation
3817 options for this are defined and restricted by the CPU used: Some CPU
3818 models provide on-chip memory (like the IMMR area on MPC8xx and
3819 MPC826x processors), on others (parts of) the data cache can be
3820 locked as (mis-) used as memory, etc.
3822 Chris Hallinan posted a good summary of these issues to the
3823 U-Boot mailing list:
3825 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
3826 From: "Chris Hallinan" <clh@net1plus.com>
3827 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
3830 Correct me if I'm wrong, folks, but the way I understand it
3831 is this: Using DCACHE as initial RAM for Stack, etc, does not
3832 require any physical RAM backing up the cache. The cleverness
3833 is that the cache is being used as a temporary supply of
3834 necessary storage before the SDRAM controller is setup. It's
3835 beyond the scope of this list to explain the details, but you
3836 can see how this works by studying the cache architecture and
3837 operation in the architecture and processor-specific manuals.
3839 OCM is On Chip Memory, which I believe the 405GP has 4K. It
3840 is another option for the system designer to use as an
3841 initial stack/RAM area prior to SDRAM being available. Either
3842 option should work for you. Using CS 4 should be fine if your
3843 board designers haven't used it for something that would
3844 cause you grief during the initial boot! It is frequently not
3847 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere
3848 with your processor/board/system design. The default value
3849 you will find in any recent u-boot distribution in
3850 walnut.h should work for you. I'd set it to a value larger
3851 than your SDRAM module. If you have a 64MB SDRAM module, set
3852 it above 400_0000. Just make sure your board has no resources
3853 that are supposed to respond to that address! That code in
3854 start.S has been around a while and should work as is when
3855 you get the config right.
3860 It is essential to remember this, since it has some impact on the C
3861 code for the initialization procedures:
3863 * Initialized global data (data segment) is read-only. Do not attempt
3866 * Do not use any uninitialized global data (or implicitely initialized
3867 as zero data - BSS segment) at all - this is undefined, initiali-
3868 zation is performed later (when relocating to RAM).
3870 * Stack space is very limited. Avoid big data buffers or things like
3873 Having only the stack as writable memory limits means we cannot use
3874 normal global data to share information beween the code. But it
3875 turned out that the implementation of U-Boot can be greatly
3876 simplified by making a global data structure (gd_t) available to all
3877 functions. We could pass a pointer to this data as argument to _all_
3878 functions, but this would bloat the code. Instead we use a feature of
3879 the GCC compiler (Global Register Variables) to share the data: we
3880 place a pointer (gd) to the global data into a register which we
3881 reserve for this purpose.
3883 When choosing a register for such a purpose we are restricted by the
3884 relevant (E)ABI specifications for the current architecture, and by
3885 GCC's implementation.
3887 For PowerPC, the following registers have specific use:
3889 R2: reserved for system use
3890 R3-R4: parameter passing and return values
3891 R5-R10: parameter passing
3892 R13: small data area pointer
3896 (U-Boot also uses R14 as internal GOT pointer.)
3898 ==> U-Boot will use R2 to hold a pointer to the global data
3900 Note: on PPC, we could use a static initializer (since the
3901 address of the global data structure is known at compile time),
3902 but it turned out that reserving a register results in somewhat
3903 smaller code - although the code savings are not that big (on
3904 average for all boards 752 bytes for the whole U-Boot image,
3905 624 text + 127 data).
3907 On Blackfin, the normal C ABI (except for P5) is followed as documented here:
3908 http://docs.blackfin.uclinux.org/doku.php?id=application_binary_interface
3910 ==> U-Boot will use P5 to hold a pointer to the global data
3912 On ARM, the following registers are used:
3914 R0: function argument word/integer result
3915 R1-R3: function argument word
3917 R10: stack limit (used only if stack checking if enabled)
3918 R11: argument (frame) pointer
3919 R12: temporary workspace
3922 R15: program counter
3924 ==> U-Boot will use R8 to hold a pointer to the global data
3926 NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope,
3927 or current versions of GCC may "optimize" the code too much.
3932 U-Boot runs in system state and uses physical addresses, i.e. the
3933 MMU is not used either for address mapping nor for memory protection.
3935 The available memory is mapped to fixed addresses using the memory
3936 controller. In this process, a contiguous block is formed for each
3937 memory type (Flash, SDRAM, SRAM), even when it consists of several
3938 physical memory banks.
3940 U-Boot is installed in the first 128 kB of the first Flash bank (on
3941 TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
3942 booting and sizing and initializing DRAM, the code relocates itself
3943 to the upper end of DRAM. Immediately below the U-Boot code some
3944 memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN
3945 configuration setting]. Below that, a structure with global Board
3946 Info data is placed, followed by the stack (growing downward).
3948 Additionally, some exception handler code is copied to the low 8 kB
3949 of DRAM (0x00000000 ... 0x00001FFF).
3951 So a typical memory configuration with 16 MB of DRAM could look like
3954 0x0000 0000 Exception Vector code
3957 0x0000 2000 Free for Application Use
3963 0x00FB FF20 Monitor Stack (Growing downward)
3964 0x00FB FFAC Board Info Data and permanent copy of global data
3965 0x00FC 0000 Malloc Arena
3968 0x00FE 0000 RAM Copy of Monitor Code
3969 ... eventually: LCD or video framebuffer
3970 ... eventually: pRAM (Protected RAM - unchanged by reset)
3971 0x00FF FFFF [End of RAM]
3974 System Initialization:
3975 ----------------------
3977 In the reset configuration, U-Boot starts at the reset entry point
3978 (on most PowerPC systems at address 0x00000100). Because of the reset
3979 configuration for CS0# this is a mirror of the onboard Flash memory.
3980 To be able to re-map memory U-Boot then jumps to its link address.
3981 To be able to implement the initialization code in C, a (small!)
3982 initial stack is set up in the internal Dual Ported RAM (in case CPUs
3983 which provide such a feature like MPC8xx or MPC8260), or in a locked
3984 part of the data cache. After that, U-Boot initializes the CPU core,
3985 the caches and the SIU.
3987 Next, all (potentially) available memory banks are mapped using a
3988 preliminary mapping. For example, we put them on 512 MB boundaries
3989 (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
3990 on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
3991 programmed for SDRAM access. Using the temporary configuration, a
3992 simple memory test is run that determines the size of the SDRAM
3995 When there is more than one SDRAM bank, and the banks are of
3996 different size, the largest is mapped first. For equal size, the first
3997 bank (CS2#) is mapped first. The first mapping is always for address
3998 0x00000000, with any additional banks following immediately to create
3999 contiguous memory starting from 0.
4001 Then, the monitor installs itself at the upper end of the SDRAM area
4002 and allocates memory for use by malloc() and for the global Board
4003 Info data; also, the exception vector code is copied to the low RAM
4004 pages, and the final stack is set up.
4006 Only after this relocation will you have a "normal" C environment;
4007 until that you are restricted in several ways, mostly because you are
4008 running from ROM, and because the code will have to be relocated to a
4012 U-Boot Porting Guide:
4013 ----------------------
4015 [Based on messages by Jerry Van Baren in the U-Boot-Users mailing
4019 int main(int argc, char *argv[])
4021 sighandler_t no_more_time;
4023 signal(SIGALRM, no_more_time);
4024 alarm(PROJECT_DEADLINE - toSec (3 * WEEK));
4026 if (available_money > available_manpower) {
4027 Pay consultant to port U-Boot;
4031 Download latest U-Boot source;
4033 Subscribe to u-boot mailing list;
4036 email("Hi, I am new to U-Boot, how do I get started?");
4039 Read the README file in the top level directory;
4040 Read http://www.denx.de/twiki/bin/view/DULG/Manual;
4041 Read applicable doc/*.README;
4042 Read the source, Luke;
4043 /* find . -name "*.[chS]" | xargs grep -i <keyword> */
4046 if (available_money > toLocalCurrency ($2500))
4049 Add a lot of aggravation and time;
4051 if (a similar board exists) { /* hopefully... */
4052 cp -a board/<similar> board/<myboard>
4053 cp include/configs/<similar>.h include/configs/<myboard>.h
4055 Create your own board support subdirectory;
4056 Create your own board include/configs/<myboard>.h file;
4058 Edit new board/<myboard> files
4059 Edit new include/configs/<myboard>.h
4064 Add / modify source code;
4068 email("Hi, I am having problems...");
4070 Send patch file to the U-Boot email list;
4071 if (reasonable critiques)
4072 Incorporate improvements from email list code review;
4074 Defend code as written;
4080 void no_more_time (int sig)
4089 All contributions to U-Boot should conform to the Linux kernel
4090 coding style; see the file "Documentation/CodingStyle" and the script
4091 "scripts/Lindent" in your Linux kernel source directory. In sources
4092 originating from U-Boot a style corresponding to "Lindent -pcs" (adding
4093 spaces before parameters to function calls) is actually used.
4095 Source files originating from a different project (for example the
4096 MTD subsystem) are generally exempt from these guidelines and are not
4097 reformated to ease subsequent migration to newer versions of those
4100 Please note that U-Boot is implemented in C (and to some small parts in
4101 Assembler); no C++ is used, so please do not use C++ style comments (//)
4104 Please also stick to the following formatting rules:
4105 - remove any trailing white space
4106 - use TAB characters for indentation, not spaces
4107 - make sure NOT to use DOS '\r\n' line feeds
4108 - do not add more than 2 empty lines to source files
4109 - do not add trailing empty lines to source files
4111 Submissions which do not conform to the standards may be returned
4112 with a request to reformat the changes.
4118 Since the number of patches for U-Boot is growing, we need to
4119 establish some rules. Submissions which do not conform to these rules
4120 may be rejected, even when they contain important and valuable stuff.
4122 Please see http://www.denx.de/wiki/U-Boot/Patches for details.
4124 Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>;
4125 see http://lists.denx.de/mailman/listinfo/u-boot
4127 When you send a patch, please include the following information with
4130 * For bug fixes: a description of the bug and how your patch fixes
4131 this bug. Please try to include a way of demonstrating that the
4132 patch actually fixes something.
4134 * For new features: a description of the feature and your
4137 * A CHANGELOG entry as plaintext (separate from the patch)
4139 * For major contributions, your entry to the CREDITS file
4141 * When you add support for a new board, don't forget to add this
4142 board to the MAKEALL script, too.
4144 * If your patch adds new configuration options, don't forget to
4145 document these in the README file.
4147 * The patch itself. If you are using git (which is *strongly*
4148 recommended) you can easily generate the patch using the
4149 "git-format-patch". If you then use "git-send-email" to send it to
4150 the U-Boot mailing list, you will avoid most of the common problems
4151 with some other mail clients.
4153 If you cannot use git, use "diff -purN OLD NEW". If your version of
4154 diff does not support these options, then get the latest version of
4157 The current directory when running this command shall be the parent
4158 directory of the U-Boot source tree (i. e. please make sure that
4159 your patch includes sufficient directory information for the
4162 We prefer patches as plain text. MIME attachments are discouraged,
4163 and compressed attachments must not be used.
4165 * If one logical set of modifications affects or creates several
4166 files, all these changes shall be submitted in a SINGLE patch file.
4168 * Changesets that contain different, unrelated modifications shall be
4169 submitted as SEPARATE patches, one patch per changeset.
4174 * Before sending the patch, run the MAKEALL script on your patched
4175 source tree and make sure that no errors or warnings are reported
4176 for any of the boards.
4178 * Keep your modifications to the necessary minimum: A patch
4179 containing several unrelated changes or arbitrary reformats will be
4180 returned with a request to re-formatting / split it.
4182 * If you modify existing code, make sure that your new code does not
4183 add to the memory footprint of the code ;-) Small is beautiful!
4184 When adding new features, these should compile conditionally only
4185 (using #ifdef), and the resulting code with the new feature
4186 disabled must not need more memory than the old code without your
4189 * Remember that there is a size limit of 100 kB per message on the
4190 u-boot mailing list. Bigger patches will be moderated. If they are
4191 reasonable and not too big, they will be acknowledged. But patches
4192 bigger than the size limit should be avoided.
projects / kernel / u-boot.git / blob