2 # (C) Copyright 2000 - 2005
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.
60 In case you have questions about, problems with or contributions for
61 U-Boot you should send a message to the U-Boot mailing list at
63 previous traffic on the mailing list - please search the archive
64 before asking FAQ's. Please see
65 http://lists.sourceforge.net/lists/listinfo/u-boot-users/
71 - start from 8xxrom sources
72 - create PPCBoot project (http://sourceforge.net/projects/ppcboot)
74 - make it easier to add custom boards
75 - make it possible to add other [PowerPC] CPUs
76 - extend functions, especially:
77 * Provide extended interface to Linux boot loader
80 * PCMCIA / CompactFLash / ATA disk / SCSI ... boot
81 - create ARMBoot project (http://sourceforge.net/projects/armboot)
82 - add other CPU families (starting with ARM)
83 - create U-Boot project (http://sourceforge.net/projects/u-boot)
89 The "official" name of this project is "Das U-Boot". The spelling
90 "U-Boot" shall be used in all written text (documentation, comments
91 in source files etc.). Example:
93 This is the README file for the U-Boot project.
95 File names etc. shall be based on the string "u-boot". Examples:
97 include/asm-ppc/u-boot.h
99 #include <asm/u-boot.h>
101 Variable names, preprocessor constants etc. shall be either based on
102 the string "u_boot" or on "U_BOOT". Example:
104 U_BOOT_VERSION u_boot_logo
105 IH_OS_U_BOOT u_boot_hush_start
111 U-Boot uses a 3 level version number containing a version, a
112 sub-version, and a patchlevel: "U-Boot-2.34.5" means version "2",
113 sub-version "34", and patchlevel "4".
115 The patchlevel is used to indicate certain stages of development
116 between released versions, i. e. officially released versions of
117 U-Boot will always have a patchlevel of "0".
123 - board Board dependent files
124 - common Misc architecture independent functions
125 - cpu CPU specific files
126 - 74xx_7xx Files specific to Freescale MPC74xx and 7xx CPUs
127 - arm720t Files specific to ARM 720 CPUs
128 - arm920t Files specific to ARM 920 CPUs
129 - at91rm9200 Files specific to Atmel AT91RM9200 CPU
130 - imx Files specific to Freescale MC9328 i.MX CPUs
131 - s3c24x0 Files specific to Samsung S3C24X0 CPUs
132 - arm925t Files specific to ARM 925 CPUs
133 - arm926ejs Files specific to ARM 926 CPUs
134 - arm1136 Files specific to ARM 1136 CPUs
135 - at32ap Files specific to Atmel AVR32 AP CPUs
136 - i386 Files specific to i386 CPUs
137 - ixp Files specific to Intel XScale IXP CPUs
138 - mcf52x2 Files specific to Freescale ColdFire MCF52x2 CPUs
139 - mips Files specific to MIPS CPUs
140 - mpc5xx Files specific to Freescale MPC5xx CPUs
141 - mpc5xxx Files specific to Freescale MPC5xxx CPUs
142 - mpc8xx Files specific to Freescale MPC8xx CPUs
143 - mpc8220 Files specific to Freescale MPC8220 CPUs
144 - mpc824x Files specific to Freescale MPC824x CPUs
145 - mpc8260 Files specific to Freescale MPC8260 CPUs
146 - mpc85xx Files specific to Freescale MPC85xx CPUs
147 - nios Files specific to Altera NIOS CPUs
148 - nios2 Files specific to Altera Nios-II CPUs
149 - ppc4xx Files specific to AMCC PowerPC 4xx CPUs
150 - pxa Files specific to Intel XScale PXA CPUs
151 - s3c44b0 Files specific to Samsung S3C44B0 CPUs
152 - sa1100 Files specific to Intel StrongARM SA1100 CPUs
153 - disk Code for disk drive partition handling
154 - doc Documentation (don't expect too much)
155 - drivers Commonly used device drivers
156 - dtt Digital Thermometer and Thermostat drivers
157 - examples Example code for standalone applications, etc.
158 - include Header Files
159 - lib_arm Files generic to ARM architecture
160 - lib_avr32 Files generic to AVR32 architecture
161 - lib_generic Files generic to all architectures
162 - lib_i386 Files generic to i386 architecture
163 - lib_m68k Files generic to m68k architecture
164 - lib_mips Files generic to MIPS architecture
165 - lib_nios Files generic to NIOS architecture
166 - lib_ppc Files generic to PowerPC architecture
167 - net Networking code
168 - post Power On Self Test
169 - rtc Real Time Clock drivers
170 - tools Tools to build S-Record or U-Boot images, etc.
172 Software Configuration:
173 =======================
175 Configuration is usually done using C preprocessor defines; the
176 rationale behind that is to avoid dead code whenever possible.
178 There are two classes of configuration variables:
180 * Configuration _OPTIONS_:
181 These are selectable by the user and have names beginning with
184 * Configuration _SETTINGS_:
185 These depend on the hardware etc. and should not be meddled with if
186 you don't know what you're doing; they have names beginning with
189 Later we will add a configuration tool - probably similar to or even
190 identical to what's used for the Linux kernel. Right now, we have to
191 do the configuration by hand, which means creating some symbolic
192 links and editing some configuration files. We use the TQM8xxL boards
196 Selection of Processor Architecture and Board Type:
197 ---------------------------------------------------
199 For all supported boards there are ready-to-use default
200 configurations available; just type "make <board_name>_config".
202 Example: For a TQM823L module type:
207 For the Cogent platform, you need to specify the cpu type as well;
208 e.g. "make cogent_mpc8xx_config". And also configure the cogent
209 directory according to the instructions in cogent/README.
212 Configuration Options:
213 ----------------------
215 Configuration depends on the combination of board and CPU type; all
216 such information is kept in a configuration file
217 "include/configs/<board_name>.h".
219 Example: For a TQM823L module, all configuration settings are in
220 "include/configs/TQM823L.h".
223 Many of the options are named exactly as the corresponding Linux
224 kernel configuration options. The intention is to make it easier to
225 build a config tool - later.
228 The following options need to be configured:
230 - CPU Type: Define exactly one of
234 CONFIG_MPC823, CONFIG_MPC850, CONFIG_MPC855, CONFIG_MPC860
237 or CONFIG_MPC824X, CONFIG_MPC8260
253 MicroBlaze based CPUs:
254 ----------------------
258 ----------------------
262 ----------------------
265 - Board Type: Define exactly one of
267 PowerPC based boards:
268 ---------------------
270 CONFIG_ADCIOP CONFIG_FPS860L CONFIG_OXC
271 CONFIG_ADS860 CONFIG_GEN860T CONFIG_PCI405
272 CONFIG_AMX860 CONFIG_GENIETV CONFIG_PCIPPC2
273 CONFIG_AP1000 CONFIG_GTH CONFIG_PCIPPC6
274 CONFIG_AR405 CONFIG_gw8260 CONFIG_pcu_e
275 CONFIG_BAB7xx CONFIG_hermes CONFIG_PIP405
276 CONFIG_BC3450 CONFIG_hymod CONFIG_PM826
277 CONFIG_c2mon CONFIG_IAD210 CONFIG_ppmc8260
278 CONFIG_CANBT CONFIG_ICU862 CONFIG_QS823
279 CONFIG_CCM CONFIG_IP860 CONFIG_QS850
280 CONFIG_CMI CONFIG_IPHASE4539 CONFIG_QS860T
281 CONFIG_cogent_mpc8260 CONFIG_IVML24 CONFIG_RBC823
282 CONFIG_cogent_mpc8xx CONFIG_IVML24_128 CONFIG_RPXClassic
283 CONFIG_CPCI405 CONFIG_IVML24_256 CONFIG_RPXlite
284 CONFIG_CPCI4052 CONFIG_IVMS8 CONFIG_RPXsuper
285 CONFIG_CPCIISER4 CONFIG_IVMS8_128 CONFIG_rsdproto
286 CONFIG_CPU86 CONFIG_IVMS8_256 CONFIG_sacsng
287 CONFIG_CRAYL1 CONFIG_JSE CONFIG_Sandpoint8240
288 CONFIG_CSB272 CONFIG_LANTEC CONFIG_Sandpoint8245
289 CONFIG_CU824 CONFIG_LITE5200B CONFIG_sbc8260
290 CONFIG_DASA_SIM CONFIG_lwmon CONFIG_sbc8560
291 CONFIG_DB64360 CONFIG_MBX CONFIG_SM850
292 CONFIG_DB64460 CONFIG_MBX860T CONFIG_SPD823TS
293 CONFIG_DU405 CONFIG_MHPC CONFIG_STXGP3
294 CONFIG_DUET_ADS CONFIG_MIP405 CONFIG_SXNI855T
295 CONFIG_EBONY CONFIG_MOUSSE CONFIG_TQM823L
296 CONFIG_ELPPC CONFIG_MPC8260ADS CONFIG_TQM8260
297 CONFIG_ELPT860 CONFIG_MPC8540ADS CONFIG_TQM850L
298 CONFIG_ep8260 CONFIG_MPC8540EVAL CONFIG_TQM855L
299 CONFIG_ERIC CONFIG_MPC8560ADS CONFIG_TQM860L
300 CONFIG_ESTEEM192E CONFIG_MUSENKI CONFIG_TTTech
301 CONFIG_ETX094 CONFIG_MVS1 CONFIG_UTX8245
302 CONFIG_EVB64260 CONFIG_NETPHONE CONFIG_V37
303 CONFIG_FADS823 CONFIG_NETTA CONFIG_W7OLMC
304 CONFIG_FADS850SAR CONFIG_NETVIA CONFIG_W7OLMG
305 CONFIG_FADS860T CONFIG_NX823 CONFIG_WALNUT
306 CONFIG_FLAGADM CONFIG_OCRTC CONFIG_ZPC1900
307 CONFIG_FPS850L CONFIG_ORSG CONFIG_ZUMA
312 CONFIG_ARMADILLO, CONFIG_AT91RM9200DK, CONFIG_CERF250,
313 CONFIG_CSB637, CONFIG_DELTA, CONFIG_DNP1110,
314 CONFIG_EP7312, CONFIG_H2_OMAP1610, CONFIG_HHP_CRADLE,
315 CONFIG_IMPA7, CONFIG_INNOVATOROMAP1510, CONFIG_INNOVATOROMAP1610,
316 CONFIG_KB9202, CONFIG_LART, CONFIG_LPD7A400,
317 CONFIG_LUBBOCK, CONFIG_OSK_OMAP5912, CONFIG_OMAP2420H4,
318 CONFIG_PLEB2, CONFIG_SHANNON, CONFIG_P2_OMAP730,
319 CONFIG_SMDK2400, CONFIG_SMDK2410, CONFIG_TRAB,
322 MicroBlaze based boards:
323 ------------------------
328 ------------------------
330 CONFIG_PCI5441 CONFIG_PK1C20
331 CONFIG_EP1C20 CONFIG_EP1S10 CONFIG_EP1S40
334 - CPU Module Type: (if CONFIG_COGENT is defined)
335 Define exactly one of
337 --- FIXME --- not tested yet:
338 CONFIG_CMA286_60, CONFIG_CMA286_21, CONFIG_CMA286_60P,
339 CONFIG_CMA287_23, CONFIG_CMA287_50
341 - Motherboard Type: (if CONFIG_COGENT is defined)
342 Define exactly one of
343 CONFIG_CMA101, CONFIG_CMA102
345 - Motherboard I/O Modules: (if CONFIG_COGENT is defined)
346 Define one or more of
349 - Motherboard Options: (if CONFIG_CMA101 or CONFIG_CMA102 are defined)
350 Define one or more of
351 CONFIG_LCD_HEARTBEAT - update a character position on
352 the lcd display every second with
355 - Board flavour: (if CONFIG_MPC8260ADS is defined)
358 CFG_8260ADS - original MPC8260ADS
359 CFG_8266ADS - MPC8266ADS
360 CFG_PQ2FADS - PQ2FADS-ZU or PQ2FADS-VR
361 CFG_8272ADS - MPC8272ADS
363 - MPC824X Family Member (if CONFIG_MPC824X is defined)
364 Define exactly one of
365 CONFIG_MPC8240, CONFIG_MPC8245
367 - 8xx CPU Options: (if using an MPC8xx cpu)
368 CONFIG_8xx_GCLK_FREQ - deprecated: CPU clock if
369 get_gclk_freq() cannot work
370 e.g. if there is no 32KHz
371 reference PIT/RTC clock
372 CONFIG_8xx_OSCLK - PLL input clock (either EXTCLK
375 - 859/866/885 CPU options: (if using a MPC859 or MPC866 or MPC885 CPU):
378 CONFIG_8xx_CPUCLK_DEFAULT
379 See doc/README.MPC866
383 Define this to measure the actual CPU clock instead
384 of relying on the correctness of the configured
385 values. Mostly useful for board bringup to make sure
386 the PLL is locked at the intended frequency. Note
387 that this requires a (stable) reference clock (32 kHz
388 RTC clock or CFG_8XX_XIN)
390 - Intel Monahans options:
391 CFG_MONAHANS_RUN_MODE_OSC_RATIO
393 Defines the Monahans run mode to oscillator
394 ratio. Valid values are 8, 16, 24, 31. The core
395 frequency is this value multiplied by 13 MHz.
397 CFG_MONAHANS_TURBO_RUN_MODE_RATIO
399 Defines the Monahans turbo mode to oscillator
400 ratio. Valid values are 1 (default if undefined) and
401 2. The core frequency as calculated above is multiplied
404 - Linux Kernel Interface:
407 U-Boot stores all clock information in Hz
408 internally. For binary compatibility with older Linux
409 kernels (which expect the clocks passed in the
410 bd_info data to be in MHz) the environment variable
411 "clocks_in_mhz" can be defined so that U-Boot
412 converts clock data to MHZ before passing it to the
414 When CONFIG_CLOCKS_IN_MHZ is defined, a definition of
415 "clocks_in_mhz=1" is automatically included in the
418 CONFIG_MEMSIZE_IN_BYTES [relevant for MIPS only]
420 When transfering memsize parameter to linux, some versions
421 expect it to be in bytes, others in MB.
422 Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes.
426 New kernel versions are expecting firmware settings to be
427 passed using flat open firmware trees.
428 The environment variable "disable_of", when set, disables this
431 CONFIG_OF_FLAT_TREE_MAX_SIZE
433 The maximum size of the constructed OF tree.
435 OF_CPU - The proper name of the cpus node.
436 OF_SOC - The proper name of the soc node.
437 OF_TBCLK - The timebase frequency.
438 OF_STDOUT_PATH - The path to the console device
442 The resulting flat device tree will have a copy of the bd_t.
443 Space should be pre-allocated in the dts for the bd_t.
445 CONFIG_OF_HAS_UBOOT_ENV
447 The resulting flat device tree will have a copy of u-boot's
448 environment variables
450 CONFIG_OF_BOARD_SETUP
452 Board code has addition modification that it wants to make
453 to the flat device tree before handing it off to the kernel
458 Define this if you want support for Amba PrimeCell PL010 UARTs.
462 Define this if you want support for Amba PrimeCell PL011 UARTs.
466 If you have Amba PrimeCell PL011 UARTs, set this variable to
467 the clock speed of the UARTs.
471 If you have Amba PrimeCell PL010 or PL011 UARTs on your board,
472 define this to a list of base addresses for each (supported)
473 port. See e.g. include/configs/versatile.h
477 Depending on board, define exactly one serial port
478 (like CONFIG_8xx_CONS_SMC1, CONFIG_8xx_CONS_SMC2,
479 CONFIG_8xx_CONS_SCC1, ...), or switch off the serial
480 console by defining CONFIG_8xx_CONS_NONE
482 Note: if CONFIG_8xx_CONS_NONE is defined, the serial
483 port routines must be defined elsewhere
484 (i.e. serial_init(), serial_getc(), ...)
487 Enables console device for a color framebuffer. Needs following
488 defines (cf. smiLynxEM, i8042, board/eltec/bab7xx)
489 VIDEO_FB_LITTLE_ENDIAN graphic memory organisation
491 VIDEO_HW_RECTFILL graphic chip supports
494 VIDEO_HW_BITBLT graphic chip supports
495 bit-blit (cf. smiLynxEM)
496 VIDEO_VISIBLE_COLS visible pixel columns
498 VIDEO_VISIBLE_ROWS visible pixel rows
499 VIDEO_PIXEL_SIZE bytes per pixel
500 VIDEO_DATA_FORMAT graphic data format
501 (0-5, cf. cfb_console.c)
502 VIDEO_FB_ADRS framebuffer address
503 VIDEO_KBD_INIT_FCT keyboard int fct
504 (i.e. i8042_kbd_init())
505 VIDEO_TSTC_FCT test char fct
507 VIDEO_GETC_FCT get char fct
509 CONFIG_CONSOLE_CURSOR cursor drawing on/off
510 (requires blink timer
512 CFG_CONSOLE_BLINK_COUNT blink interval (cf. i8042.c)
513 CONFIG_CONSOLE_TIME display time/date info in
515 (requires CFG_CMD_DATE)
516 CONFIG_VIDEO_LOGO display Linux logo in
518 CONFIG_VIDEO_BMP_LOGO use bmp_logo.h instead of
519 linux_logo.h for logo.
520 Requires CONFIG_VIDEO_LOGO
521 CONFIG_CONSOLE_EXTRA_INFO
522 addional board info beside
525 When CONFIG_CFB_CONSOLE is defined, video console is
526 default i/o. Serial console can be forced with
527 environment 'console=serial'.
529 When CONFIG_SILENT_CONSOLE is defined, all console
530 messages (by U-Boot and Linux!) can be silenced with
531 the "silent" environment variable. See
532 doc/README.silent for more information.
535 CONFIG_BAUDRATE - in bps
536 Select one of the baudrates listed in
537 CFG_BAUDRATE_TABLE, see below.
538 CFG_BRGCLK_PRESCALE, baudrate prescale
540 - Interrupt driven serial port input:
541 CONFIG_SERIAL_SOFTWARE_FIFO
544 Use an interrupt handler for receiving data on the
545 serial port. It also enables using hardware handshake
546 (RTS/CTS) and UART's built-in FIFO. Set the number of
547 bytes the interrupt driven input buffer should have.
549 Leave undefined to disable this feature, including
550 disable the buffer and hardware handshake.
552 - Console UART Number:
556 If defined internal UART1 (and not UART0) is used
557 as default U-Boot console.
559 - Boot Delay: CONFIG_BOOTDELAY - in seconds
560 Delay before automatically booting the default image;
561 set to -1 to disable autoboot.
563 See doc/README.autoboot for these options that
564 work with CONFIG_BOOTDELAY. None are required.
565 CONFIG_BOOT_RETRY_TIME
566 CONFIG_BOOT_RETRY_MIN
567 CONFIG_AUTOBOOT_KEYED
568 CONFIG_AUTOBOOT_PROMPT
569 CONFIG_AUTOBOOT_DELAY_STR
570 CONFIG_AUTOBOOT_STOP_STR
571 CONFIG_AUTOBOOT_DELAY_STR2
572 CONFIG_AUTOBOOT_STOP_STR2
573 CONFIG_ZERO_BOOTDELAY_CHECK
574 CONFIG_RESET_TO_RETRY
578 Only needed when CONFIG_BOOTDELAY is enabled;
579 define a command string that is automatically executed
580 when no character is read on the console interface
581 within "Boot Delay" after reset.
584 This can be used to pass arguments to the bootm
585 command. The value of CONFIG_BOOTARGS goes into the
586 environment value "bootargs".
588 CONFIG_RAMBOOT and CONFIG_NFSBOOT
589 The value of these goes into the environment as
590 "ramboot" and "nfsboot" respectively, and can be used
591 as a convenience, when switching between booting from
597 When this option is #defined, the existence of the
598 environment variable "preboot" will be checked
599 immediately before starting the CONFIG_BOOTDELAY
600 countdown and/or running the auto-boot command resp.
601 entering interactive mode.
603 This feature is especially useful when "preboot" is
604 automatically generated or modified. For an example
605 see the LWMON board specific code: here "preboot" is
606 modified when the user holds down a certain
607 combination of keys on the (special) keyboard when
610 - Serial Download Echo Mode:
612 If defined to 1, all characters received during a
613 serial download (using the "loads" command) are
614 echoed back. This might be needed by some terminal
615 emulations (like "cu"), but may as well just take
616 time on others. This setting #define's the initial
617 value of the "loads_echo" environment variable.
619 - Kgdb Serial Baudrate: (if CFG_CMD_KGDB is defined)
621 Select one of the baudrates listed in
622 CFG_BAUDRATE_TABLE, see below.
626 Most monitor functions can be selected (or
627 de-selected) by adjusting the definition of
628 CONFIG_COMMANDS; to select individual functions,
629 #define CONFIG_COMMANDS by "OR"ing any of the
632 #define enables commands:
633 -------------------------
634 CFG_CMD_ASKENV * ask for env variable
635 CFG_CMD_AUTOSCRIPT Autoscript Support
637 CFG_CMD_BEDBUG * Include BedBug Debugger
638 CFG_CMD_BMP * BMP support
639 CFG_CMD_BSP * Board specific commands
641 CFG_CMD_CACHE * icache, dcache
642 CFG_CMD_CONSOLE coninfo
643 CFG_CMD_DATE * support for RTC, date/time...
644 CFG_CMD_DHCP * DHCP support
645 CFG_CMD_DIAG * Diagnostics
646 CFG_CMD_DOC * Disk-On-Chip Support
647 CFG_CMD_DTT * Digital Therm and Thermostat
648 CFG_CMD_ECHO echo arguments
649 CFG_CMD_EEPROM * EEPROM read/write support
650 CFG_CMD_ELF * bootelf, bootvx
652 CFG_CMD_FDC * Floppy Disk Support
653 CFG_CMD_FAT * FAT partition support
654 CFG_CMD_FDOS * Dos diskette Support
655 CFG_CMD_FLASH flinfo, erase, protect
656 CFG_CMD_FPGA FPGA device initialization support
657 CFG_CMD_HWFLOW * RTS/CTS hw flow control
658 CFG_CMD_I2C * I2C serial bus support
659 CFG_CMD_IDE * IDE harddisk support
661 CFG_CMD_IMLS List all found images
662 CFG_CMD_IMMAP * IMMR dump support
663 CFG_CMD_IRQ * irqinfo
664 CFG_CMD_ITEST Integer/string test of 2 values
665 CFG_CMD_JFFS2 * JFFS2 Support
669 CFG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base,
671 CFG_CMD_MISC Misc functions like sleep etc
672 CFG_CMD_MMC * MMC memory mapped support
673 CFG_CMD_MII * MII utility commands
674 CFG_CMD_NAND * NAND support
675 CFG_CMD_NET bootp, tftpboot, rarpboot
676 CFG_CMD_PCI * pciinfo
677 CFG_CMD_PCMCIA * PCMCIA support
678 CFG_CMD_PING * send ICMP ECHO_REQUEST to network host
679 CFG_CMD_PORTIO * Port I/O
680 CFG_CMD_REGINFO * Register dump
681 CFG_CMD_RUN run command in env variable
682 CFG_CMD_SAVES * save S record dump
683 CFG_CMD_SCSI * SCSI Support
684 CFG_CMD_SDRAM * print SDRAM configuration information
685 (requires CFG_CMD_I2C)
686 CFG_CMD_SETGETDCR Support for DCR Register access (4xx only)
687 CFG_CMD_SPI * SPI serial bus support
688 CFG_CMD_USB * USB support
689 CFG_CMD_VFD * VFD support (TRAB)
690 CFG_CMD_BSP * Board SPecific functions
691 CFG_CMD_CDP * Cisco Discover Protocol support
692 -----------------------------------------------
695 CONFIG_CMD_DFL Default configuration; at the moment
696 this is includes all commands, except
697 the ones marked with "*" in the list
700 If you don't define CONFIG_COMMANDS it defaults to
701 CONFIG_CMD_DFL in include/cmd_confdefs.h. A board can
702 override the default settings in the respective
705 EXAMPLE: If you want all functions except of network
706 support you can write:
708 #define CONFIG_COMMANDS (CFG_CMD_ALL & ~CFG_CMD_NET)
711 Note: Don't enable the "icache" and "dcache" commands
712 (configuration option CFG_CMD_CACHE) unless you know
713 what you (and your U-Boot users) are doing. Data
714 cache cannot be enabled on systems like the 8xx or
715 8260 (where accesses to the IMMR region must be
716 uncached), and it cannot be disabled on all other
717 systems where we (mis-) use the data cache to hold an
718 initial stack and some data.
721 XXX - this list needs to get updated!
725 If this variable is defined, it enables watchdog
726 support. There must be support in the platform specific
727 code for a watchdog. For the 8xx and 8260 CPUs, the
728 SIU Watchdog feature is enabled in the SYPCR
732 CONFIG_VERSION_VARIABLE
733 If this variable is defined, an environment variable
734 named "ver" is created by U-Boot showing the U-Boot
735 version as printed by the "version" command.
736 This variable is readonly.
740 When CFG_CMD_DATE is selected, the type of the RTC
741 has to be selected, too. Define exactly one of the
744 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx
745 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC
746 CONFIG_RTC_MC146818 - use MC146818 RTC
747 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC
748 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC
749 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC
750 CONFIG_RTC_DS164x - use Dallas DS164x RTC
751 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC
753 Note that if the RTC uses I2C, then the I2C interface
754 must also be configured. See I2C Support, below.
758 When CONFIG_TIMESTAMP is selected, the timestamp
759 (date and time) of an image is printed by image
760 commands like bootm or iminfo. This option is
761 automatically enabled when you select CFG_CMD_DATE .
764 CONFIG_MAC_PARTITION and/or CONFIG_DOS_PARTITION
765 and/or CONFIG_ISO_PARTITION
767 If IDE or SCSI support is enabled (CFG_CMD_IDE or
768 CFG_CMD_SCSI) you must configure support for at least
769 one partition type as well.
772 CONFIG_IDE_RESET_ROUTINE - this is defined in several
773 board configurations files but used nowhere!
775 CONFIG_IDE_RESET - is this is defined, IDE Reset will
776 be performed by calling the function
777 ide_set_reset(int reset)
778 which has to be defined in a board specific file
783 Set this to enable ATAPI support.
788 Set this to enable support for disks larger than 137GB
789 Also look at CFG_64BIT_LBA ,CFG_64BIT_VSPRINTF and CFG_64BIT_STRTOUL
790 Whithout these , LBA48 support uses 32bit variables and will 'only'
791 support disks up to 2.1TB.
794 When enabled, makes the IDE subsystem use 64bit sector addresses.
798 At the moment only there is only support for the
799 SYM53C8XX SCSI controller; define
800 CONFIG_SCSI_SYM53C8XX to enable it.
802 CFG_SCSI_MAX_LUN [8], CFG_SCSI_MAX_SCSI_ID [7] and
803 CFG_SCSI_MAX_DEVICE [CFG_SCSI_MAX_SCSI_ID *
804 CFG_SCSI_MAX_LUN] can be adjusted to define the
805 maximum numbers of LUNs, SCSI ID's and target
807 CFG_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz)
809 - NETWORK Support (PCI):
811 Support for Intel 8254x gigabit chips.
814 Support for Intel 82557/82559/82559ER chips.
815 Optional CONFIG_EEPRO100_SROM_WRITE enables eeprom
816 write routine for first time initialisation.
819 Support for Digital 2114x chips.
820 Optional CONFIG_TULIP_SELECT_MEDIA for board specific
821 modem chip initialisation (KS8761/QS6611).
824 Support for National dp83815 chips.
827 Support for National dp8382[01] gigabit chips.
829 - NETWORK Support (other):
831 CONFIG_DRIVER_LAN91C96
832 Support for SMSC's LAN91C96 chips.
835 Define this to hold the physical address
836 of the LAN91C96's I/O space
838 CONFIG_LAN91C96_USE_32_BIT
839 Define this to enable 32 bit addressing
841 CONFIG_DRIVER_SMC91111
842 Support for SMSC's LAN91C111 chip
845 Define this to hold the physical address
846 of the device (I/O space)
848 CONFIG_SMC_USE_32_BIT
849 Define this if data bus is 32 bits
851 CONFIG_SMC_USE_IOFUNCS
852 Define this to use i/o functions instead of macros
853 (some hardware wont work with macros)
856 At the moment only the UHCI host controller is
857 supported (PIP405, MIP405, MPC5200); define
858 CONFIG_USB_UHCI to enable it.
859 define CONFIG_USB_KEYBOARD to enable the USB Keyboard
860 and define CONFIG_USB_STORAGE to enable the USB
863 Supported are USB Keyboards and USB Floppy drives
865 MPC5200 USB requires additional defines:
867 for 528 MHz Clock: 0x0001bbbb
869 for differential drivers: 0x00001000
870 for single ended drivers: 0x00005000
874 The MMC controller on the Intel PXA is supported. To
875 enable this define CONFIG_MMC. The MMC can be
876 accessed from the boot prompt by mapping the device
877 to physical memory similar to flash. Command line is
878 enabled with CFG_CMD_MMC. The MMC driver also works with
879 the FAT fs. This is enabled with CFG_CMD_FAT.
881 - Journaling Flash filesystem support:
882 CONFIG_JFFS2_NAND, CONFIG_JFFS2_NAND_OFF, CONFIG_JFFS2_NAND_SIZE,
883 CONFIG_JFFS2_NAND_DEV
884 Define these for a default partition on a NAND device
886 CFG_JFFS2_FIRST_SECTOR,
887 CFG_JFFS2_FIRST_BANK, CFG_JFFS2_NUM_BANKS
888 Define these for a default partition on a NOR device
891 Define this to create an own partition. You have to provide a
892 function struct part_info* jffs2_part_info(int part_num)
894 If you define only one JFFS2 partition you may also want to
895 #define CFG_JFFS_SINGLE_PART 1
896 to disable the command chpart. This is the default when you
897 have not defined a custom partition
902 Define this to enable standard (PC-Style) keyboard
906 Standard PC keyboard driver with US (is default) and
907 GERMAN key layout (switch via environment 'keymap=de') support.
908 Export function i8042_kbd_init, i8042_tstc and i8042_getc
909 for cfb_console. Supports cursor blinking.
914 Define this to enable video support (for output to
919 Enable Chips & Technologies 69000 Video chip
921 CONFIG_VIDEO_SMI_LYNXEM
922 Enable Silicon Motion SMI 712/710/810 Video chip. The
923 video output is selected via environment 'videoout'
924 (1 = LCD and 2 = CRT). If videoout is undefined, CRT is
927 For the CT69000 and SMI_LYNXEM drivers, videomode is
928 selected via environment 'videomode'. Two diferent ways
930 - "videomode=num" 'num' is a standard LiLo mode numbers.
931 Following standard modes are supported (* is default):
933 Colors 640x480 800x600 1024x768 1152x864 1280x1024
934 -------------+---------------------------------------------
935 8 bits | 0x301* 0x303 0x305 0x161 0x307
936 15 bits | 0x310 0x313 0x316 0x162 0x319
937 16 bits | 0x311 0x314 0x317 0x163 0x31A
938 24 bits | 0x312 0x315 0x318 ? 0x31B
939 -------------+---------------------------------------------
940 (i.e. setenv videomode 317; saveenv; reset;)
942 - "videomode=bootargs" all the video parameters are parsed
943 from the bootargs. (See drivers/videomodes.c)
946 CONFIG_VIDEO_SED13806
947 Enable Epson SED13806 driver. This driver supports 8bpp
948 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP
949 or CONFIG_VIDEO_SED13806_16BPP
954 Define this to enable a custom keyboard support.
955 This simply calls drv_keyboard_init() which must be
956 defined in your board-specific files.
957 The only board using this so far is RBC823.
959 - LCD Support: CONFIG_LCD
961 Define this to enable LCD support (for output to LCD
962 display); also select one of the supported displays
963 by defining one of these:
965 CONFIG_NEC_NL6448AC33:
967 NEC NL6448AC33-18. Active, color, single scan.
969 CONFIG_NEC_NL6448BC20
971 NEC NL6448BC20-08. 6.5", 640x480.
972 Active, color, single scan.
974 CONFIG_NEC_NL6448BC33_54
976 NEC NL6448BC33-54. 10.4", 640x480.
977 Active, color, single scan.
981 Sharp 320x240. Active, color, single scan.
982 It isn't 16x9, and I am not sure what it is.
984 CONFIG_SHARP_LQ64D341
986 Sharp LQ64D341 display, 640x480.
987 Active, color, single scan.
991 HLD1045 display, 640x480.
992 Active, color, single scan.
996 Optrex CBL50840-2 NF-FW 99 22 M5
998 Hitachi LMG6912RPFC-00T
1002 320x240. Black & white.
1004 Normally display is black on white background; define
1005 CFG_WHITE_ON_BLACK to get it inverted.
1007 - Splash Screen Support: CONFIG_SPLASH_SCREEN
1009 If this option is set, the environment is checked for
1010 a variable "splashimage". If found, the usual display
1011 of logo, copyright and system information on the LCD
1012 is suppressed and the BMP image at the address
1013 specified in "splashimage" is loaded instead. The
1014 console is redirected to the "nulldev", too. This
1015 allows for a "silent" boot where a splash screen is
1016 loaded very quickly after power-on.
1018 - Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP
1020 If this option is set, additionally to standard BMP
1021 images, gzipped BMP images can be displayed via the
1022 splashscreen support or the bmp command.
1024 - Compression support:
1027 If this option is set, support for bzip2 compressed
1028 images is included. If not, only uncompressed and gzip
1029 compressed images are supported.
1031 NOTE: the bzip2 algorithm requires a lot of RAM, so
1032 the malloc area (as defined by CFG_MALLOC_LEN) should
1038 The address of PHY on MII bus.
1040 CONFIG_PHY_CLOCK_FREQ (ppc4xx)
1042 The clock frequency of the MII bus
1046 If this option is set, support for speed/duplex
1047 detection of Gigabit PHY is included.
1049 CONFIG_PHY_RESET_DELAY
1051 Some PHY like Intel LXT971A need extra delay after
1052 reset before any MII register access is possible.
1053 For such PHY, set this option to the usec delay
1054 required. (minimum 300usec for LXT971A)
1056 CONFIG_PHY_CMD_DELAY (ppc4xx)
1058 Some PHY like Intel LXT971A need extra delay after
1059 command issued before MII status register can be read
1066 Define a default value for ethernet address to use
1067 for the respective ethernet interface, in case this
1068 is not determined automatically.
1073 Define a default value for the IP address to use for
1074 the default ethernet interface, in case this is not
1075 determined through e.g. bootp.
1077 - Server IP address:
1080 Defines a default value for theIP address of a TFTP
1081 server to contact when using the "tftboot" command.
1083 - BOOTP Recovery Mode:
1084 CONFIG_BOOTP_RANDOM_DELAY
1086 If you have many targets in a network that try to
1087 boot using BOOTP, you may want to avoid that all
1088 systems send out BOOTP requests at precisely the same
1089 moment (which would happen for instance at recovery
1090 from a power failure, when all systems will try to
1091 boot, thus flooding the BOOTP server. Defining
1092 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
1093 inserted before sending out BOOTP requests. The
1094 following delays are insterted then:
1096 1st BOOTP request: delay 0 ... 1 sec
1097 2nd BOOTP request: delay 0 ... 2 sec
1098 3rd BOOTP request: delay 0 ... 4 sec
1100 BOOTP requests: delay 0 ... 8 sec
1102 - DHCP Advanced Options:
1105 You can fine tune the DHCP functionality by adding
1106 these flags to the CONFIG_BOOTP_MASK define:
1108 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS
1109 serverip from a DHCP server, it is possible that more
1110 than one DNS serverip is offered to the client.
1111 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS
1112 serverip will be stored in the additional environment
1113 variable "dnsip2". The first DNS serverip is always
1114 stored in the variable "dnsip", when CONFIG_BOOTP_DNS
1115 is added to the CONFIG_BOOTP_MASK.
1117 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable
1118 to do a dynamic update of a DNS server. To do this, they
1119 need the hostname of the DHCP requester.
1120 If CONFIG_BOOP_SEND_HOSTNAME is added to the
1121 CONFIG_BOOTP_MASK, the content of the "hostname"
1122 environment variable is passed as option 12 to
1126 CONFIG_CDP_DEVICE_ID
1128 The device id used in CDP trigger frames.
1130 CONFIG_CDP_DEVICE_ID_PREFIX
1132 A two character string which is prefixed to the MAC address
1137 A printf format string which contains the ascii name of
1138 the port. Normally is set to "eth%d" which sets
1139 eth0 for the first ethernet, eth1 for the second etc.
1141 CONFIG_CDP_CAPABILITIES
1143 A 32bit integer which indicates the device capabilities;
1144 0x00000010 for a normal host which does not forwards.
1148 An ascii string containing the version of the software.
1152 An ascii string containing the name of the platform.
1156 A 32bit integer sent on the trigger.
1158 CONFIG_CDP_POWER_CONSUMPTION
1160 A 16bit integer containing the power consumption of the
1161 device in .1 of milliwatts.
1163 CONFIG_CDP_APPLIANCE_VLAN_TYPE
1165 A byte containing the id of the VLAN.
1167 - Status LED: CONFIG_STATUS_LED
1169 Several configurations allow to display the current
1170 status using a LED. For instance, the LED will blink
1171 fast while running U-Boot code, stop blinking as
1172 soon as a reply to a BOOTP request was received, and
1173 start blinking slow once the Linux kernel is running
1174 (supported by a status LED driver in the Linux
1175 kernel). Defining CONFIG_STATUS_LED enables this
1178 - CAN Support: CONFIG_CAN_DRIVER
1180 Defining CONFIG_CAN_DRIVER enables CAN driver support
1181 on those systems that support this (optional)
1182 feature, like the TQM8xxL modules.
1184 - I2C Support: CONFIG_HARD_I2C | CONFIG_SOFT_I2C
1186 These enable I2C serial bus commands. Defining either of
1187 (but not both of) CONFIG_HARD_I2C or CONFIG_SOFT_I2C will
1188 include the appropriate I2C driver for the selected cpu.
1190 This will allow you to use i2c commands at the u-boot
1191 command line (as long as you set CFG_CMD_I2C in
1192 CONFIG_COMMANDS) and communicate with i2c based realtime
1193 clock chips. See common/cmd_i2c.c for a description of the
1194 command line interface.
1196 CONFIG_HARD_I2C selects the CPM hardware driver for I2C.
1198 CONFIG_SOFT_I2C configures u-boot to use a software (aka
1199 bit-banging) driver instead of CPM or similar hardware
1202 There are several other quantities that must also be
1203 defined when you define CONFIG_HARD_I2C or CONFIG_SOFT_I2C.
1205 In both cases you will need to define CFG_I2C_SPEED
1206 to be the frequency (in Hz) at which you wish your i2c bus
1207 to run and CFG_I2C_SLAVE to be the address of this node (ie
1208 the cpu's i2c node address).
1210 Now, the u-boot i2c code for the mpc8xx (cpu/mpc8xx/i2c.c)
1211 sets the cpu up as a master node and so its address should
1212 therefore be cleared to 0 (See, eg, MPC823e User's Manual
1213 p.16-473). So, set CFG_I2C_SLAVE to 0.
1215 That's all that's required for CONFIG_HARD_I2C.
1217 If you use the software i2c interface (CONFIG_SOFT_I2C)
1218 then the following macros need to be defined (examples are
1219 from include/configs/lwmon.h):
1223 (Optional). Any commands necessary to enable the I2C
1224 controller or configure ports.
1226 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
1230 (Only for MPC8260 CPU). The I/O port to use (the code
1231 assumes both bits are on the same port). Valid values
1232 are 0..3 for ports A..D.
1236 The code necessary to make the I2C data line active
1237 (driven). If the data line is open collector, this
1240 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
1244 The code necessary to make the I2C data line tri-stated
1245 (inactive). If the data line is open collector, this
1248 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
1252 Code that returns TRUE if the I2C data line is high,
1255 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
1259 If <bit> is TRUE, sets the I2C data line high. If it
1260 is FALSE, it clears it (low).
1262 eg: #define I2C_SDA(bit) \
1263 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
1264 else immr->im_cpm.cp_pbdat &= ~PB_SDA
1268 If <bit> is TRUE, sets the I2C clock line high. If it
1269 is FALSE, it clears it (low).
1271 eg: #define I2C_SCL(bit) \
1272 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
1273 else immr->im_cpm.cp_pbdat &= ~PB_SCL
1277 This delay is invoked four times per clock cycle so this
1278 controls the rate of data transfer. The data rate thus
1279 is 1 / (I2C_DELAY * 4). Often defined to be something
1282 #define I2C_DELAY udelay(2)
1286 When a board is reset during an i2c bus transfer
1287 chips might think that the current transfer is still
1288 in progress. On some boards it is possible to access
1289 the i2c SCLK line directly, either by using the
1290 processor pin as a GPIO or by having a second pin
1291 connected to the bus. If this option is defined a
1292 custom i2c_init_board() routine in boards/xxx/board.c
1293 is run early in the boot sequence.
1295 CONFIG_I2CFAST (PPC405GP|PPC405EP only)
1297 This option enables configuration of bi_iic_fast[] flags
1298 in u-boot bd_info structure based on u-boot environment
1299 variable "i2cfast". (see also i2cfast)
1301 - SPI Support: CONFIG_SPI
1303 Enables SPI driver (so far only tested with
1304 SPI EEPROM, also an instance works with Crystal A/D and
1305 D/As on the SACSng board)
1309 Enables extended (16-bit) SPI EEPROM addressing.
1310 (symmetrical to CONFIG_I2C_X)
1314 Enables a software (bit-bang) SPI driver rather than
1315 using hardware support. This is a general purpose
1316 driver that only requires three general I/O port pins
1317 (two outputs, one input) to function. If this is
1318 defined, the board configuration must define several
1319 SPI configuration items (port pins to use, etc). For
1320 an example, see include/configs/sacsng.h.
1322 - FPGA Support: CONFIG_FPGA_COUNT
1324 Specify the number of FPGA devices to support.
1328 Used to specify the types of FPGA devices. For example,
1329 #define CONFIG_FPGA CFG_XILINX_VIRTEX2
1331 CFG_FPGA_PROG_FEEDBACK
1333 Enable printing of hash marks during FPGA configuration.
1337 Enable checks on FPGA configuration interface busy
1338 status by the configuration function. This option
1339 will require a board or device specific function to
1344 If defined, a function that provides delays in the FPGA
1345 configuration driver.
1347 CFG_FPGA_CHECK_CTRLC
1348 Allow Control-C to interrupt FPGA configuration
1350 CFG_FPGA_CHECK_ERROR
1352 Check for configuration errors during FPGA bitfile
1353 loading. For example, abort during Virtex II
1354 configuration if the INIT_B line goes low (which
1355 indicated a CRC error).
1359 Maximum time to wait for the INIT_B line to deassert
1360 after PROB_B has been deasserted during a Virtex II
1361 FPGA configuration sequence. The default time is 500
1366 Maximum time to wait for BUSY to deassert during
1367 Virtex II FPGA configuration. The default is 5 mS.
1369 CFG_FPGA_WAIT_CONFIG
1371 Time to wait after FPGA configuration. The default is
1374 - Configuration Management:
1377 If defined, this string will be added to the U-Boot
1378 version information (U_BOOT_VERSION)
1380 - Vendor Parameter Protection:
1382 U-Boot considers the values of the environment
1383 variables "serial#" (Board Serial Number) and
1384 "ethaddr" (Ethernet Address) to be parameters that
1385 are set once by the board vendor / manufacturer, and
1386 protects these variables from casual modification by
1387 the user. Once set, these variables are read-only,
1388 and write or delete attempts are rejected. You can
1389 change this behviour:
1391 If CONFIG_ENV_OVERWRITE is #defined in your config
1392 file, the write protection for vendor parameters is
1393 completely disabled. Anybody can change or delete
1396 Alternatively, if you #define _both_ CONFIG_ETHADDR
1397 _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
1398 ethernet address is installed in the environment,
1399 which can be changed exactly ONCE by the user. [The
1400 serial# is unaffected by this, i. e. it remains
1406 Define this variable to enable the reservation of
1407 "protected RAM", i. e. RAM which is not overwritten
1408 by U-Boot. Define CONFIG_PRAM to hold the number of
1409 kB you want to reserve for pRAM. You can overwrite
1410 this default value by defining an environment
1411 variable "pram" to the number of kB you want to
1412 reserve. Note that the board info structure will
1413 still show the full amount of RAM. If pRAM is
1414 reserved, a new environment variable "mem" will
1415 automatically be defined to hold the amount of
1416 remaining RAM in a form that can be passed as boot
1417 argument to Linux, for instance like that:
1419 setenv bootargs ... mem=\${mem}
1422 This way you can tell Linux not to use this memory,
1423 either, which results in a memory region that will
1424 not be affected by reboots.
1426 *WARNING* If your board configuration uses automatic
1427 detection of the RAM size, you must make sure that
1428 this memory test is non-destructive. So far, the
1429 following board configurations are known to be
1432 ETX094, IVMS8, IVML24, SPD8xx, TQM8xxL,
1433 HERMES, IP860, RPXlite, LWMON, LANTEC,
1434 PCU_E, FLAGADM, TQM8260
1439 Define this variable to stop the system in case of a
1440 fatal error, so that you have to reset it manually.
1441 This is probably NOT a good idea for an embedded
1442 system where you want to system to reboot
1443 automatically as fast as possible, but it may be
1444 useful during development since you can try to debug
1445 the conditions that lead to the situation.
1447 CONFIG_NET_RETRY_COUNT
1449 This variable defines the number of retries for
1450 network operations like ARP, RARP, TFTP, or BOOTP
1451 before giving up the operation. If not defined, a
1452 default value of 5 is used.
1454 - Command Interpreter:
1457 Enable auto completion of commands using TAB.
1461 Define this variable to enable the "hush" shell (from
1462 Busybox) as command line interpreter, thus enabling
1463 powerful command line syntax like
1464 if...then...else...fi conditionals or `&&' and '||'
1465 constructs ("shell scripts").
1467 If undefined, you get the old, much simpler behaviour
1468 with a somewhat smaller memory footprint.
1473 This defines the secondary prompt string, which is
1474 printed when the command interpreter needs more input
1475 to complete a command. Usually "> ".
1479 In the current implementation, the local variables
1480 space and global environment variables space are
1481 separated. Local variables are those you define by
1482 simply typing `name=value'. To access a local
1483 variable later on, you have write `$name' or
1484 `${name}'; to execute the contents of a variable
1485 directly type `$name' at the command prompt.
1487 Global environment variables are those you use
1488 setenv/printenv to work with. To run a command stored
1489 in such a variable, you need to use the run command,
1490 and you must not use the '$' sign to access them.
1492 To store commands and special characters in a
1493 variable, please use double quotation marks
1494 surrounding the whole text of the variable, instead
1495 of the backslashes before semicolons and special
1498 - Commandline Editing and History:
1499 CONFIG_CMDLINE_EDITING
1501 Enable editiong and History functions for interactive
1502 commandline input operations
1504 - Default Environment:
1505 CONFIG_EXTRA_ENV_SETTINGS
1507 Define this to contain any number of null terminated
1508 strings (variable = value pairs) that will be part of
1509 the default environment compiled into the boot image.
1511 For example, place something like this in your
1512 board's config file:
1514 #define CONFIG_EXTRA_ENV_SETTINGS \
1518 Warning: This method is based on knowledge about the
1519 internal format how the environment is stored by the
1520 U-Boot code. This is NOT an official, exported
1521 interface! Although it is unlikely that this format
1522 will change soon, there is no guarantee either.
1523 You better know what you are doing here.
1525 Note: overly (ab)use of the default environment is
1526 discouraged. Make sure to check other ways to preset
1527 the environment like the autoscript function or the
1530 - DataFlash Support:
1531 CONFIG_HAS_DATAFLASH
1533 Defining this option enables DataFlash features and
1534 allows to read/write in Dataflash via the standard
1537 - SystemACE Support:
1540 Adding this option adds support for Xilinx SystemACE
1541 chips attached via some sort of local bus. The address
1542 of the chip must alsh be defined in the
1543 CFG_SYSTEMACE_BASE macro. For example:
1545 #define CONFIG_SYSTEMACE
1546 #define CFG_SYSTEMACE_BASE 0xf0000000
1548 When SystemACE support is added, the "ace" device type
1549 becomes available to the fat commands, i.e. fatls.
1551 - TFTP Fixed UDP Port:
1554 If this is defined, the environment variable tftpsrcp
1555 is used to supply the TFTP UDP source port value.
1556 If tftpsrcp isn't defined, the normal pseudo-random port
1557 number generator is used.
1559 Also, the environment variable tftpdstp is used to supply
1560 the TFTP UDP destination port value. If tftpdstp isn't
1561 defined, the normal port 69 is used.
1563 The purpose for tftpsrcp is to allow a TFTP server to
1564 blindly start the TFTP transfer using the pre-configured
1565 target IP address and UDP port. This has the effect of
1566 "punching through" the (Windows XP) firewall, allowing
1567 the remainder of the TFTP transfer to proceed normally.
1568 A better solution is to properly configure the firewall,
1569 but sometimes that is not allowed.
1571 - Show boot progress:
1572 CONFIG_SHOW_BOOT_PROGRESS
1574 Defining this option allows to add some board-
1575 specific code (calling a user-provided function
1576 "show_boot_progress(int)") that enables you to show
1577 the system's boot progress on some display (for
1578 example, some LED's) on your board. At the moment,
1579 the following checkpoints are implemented:
1582 1 common/cmd_bootm.c before attempting to boot an image
1583 -1 common/cmd_bootm.c Image header has bad magic number
1584 2 common/cmd_bootm.c Image header has correct magic number
1585 -2 common/cmd_bootm.c Image header has bad checksum
1586 3 common/cmd_bootm.c Image header has correct checksum
1587 -3 common/cmd_bootm.c Image data has bad checksum
1588 4 common/cmd_bootm.c Image data has correct checksum
1589 -4 common/cmd_bootm.c Image is for unsupported architecture
1590 5 common/cmd_bootm.c Architecture check OK
1591 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi, standalone)
1592 6 common/cmd_bootm.c Image Type check OK
1593 -6 common/cmd_bootm.c gunzip uncompression error
1594 -7 common/cmd_bootm.c Unimplemented compression type
1595 7 common/cmd_bootm.c Uncompression OK
1596 -8 common/cmd_bootm.c Wrong Image Type (not kernel, multi, standalone)
1597 8 common/cmd_bootm.c Image Type check OK
1598 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX)
1599 9 common/cmd_bootm.c Start initial ramdisk verification
1600 -10 common/cmd_bootm.c Ramdisk header has bad magic number
1601 -11 common/cmd_bootm.c Ramdisk header has bad checksum
1602 10 common/cmd_bootm.c Ramdisk header is OK
1603 -12 common/cmd_bootm.c Ramdisk data has bad checksum
1604 11 common/cmd_bootm.c Ramdisk data has correct checksum
1605 12 common/cmd_bootm.c Ramdisk verification complete, start loading
1606 -13 common/cmd_bootm.c Wrong Image Type (not PPC Linux Ramdisk)
1607 13 common/cmd_bootm.c Start multifile image verification
1608 14 common/cmd_bootm.c No initial ramdisk, no multifile, continue.
1609 15 common/cmd_bootm.c All preparation done, transferring control to OS
1611 -30 lib_ppc/board.c Fatal error, hang the system
1612 -31 post/post.c POST test failed, detected by post_output_backlog()
1613 -32 post/post.c POST test failed, detected by post_run_single()
1615 -1 common/cmd_doc.c Bad usage of "doc" command
1616 -1 common/cmd_doc.c No boot device
1617 -1 common/cmd_doc.c Unknown Chip ID on boot device
1618 -1 common/cmd_doc.c Read Error on boot device
1619 -1 common/cmd_doc.c Image header has bad magic number
1621 -1 common/cmd_ide.c Bad usage of "ide" command
1622 -1 common/cmd_ide.c No boot device
1623 -1 common/cmd_ide.c Unknown boot device
1624 -1 common/cmd_ide.c Unknown partition table
1625 -1 common/cmd_ide.c Invalid partition type
1626 -1 common/cmd_ide.c Read Error on boot device
1627 -1 common/cmd_ide.c Image header has bad magic number
1629 -1 common/cmd_nand.c Bad usage of "nand" command
1630 -1 common/cmd_nand.c No boot device
1631 -1 common/cmd_nand.c Unknown Chip ID on boot device
1632 -1 common/cmd_nand.c Read Error on boot device
1633 -1 common/cmd_nand.c Image header has bad magic number
1635 -1 common/env_common.c Environment has a bad CRC, using default
1641 [so far only for SMDK2400 and TRAB boards]
1643 - Modem support endable:
1644 CONFIG_MODEM_SUPPORT
1646 - RTS/CTS Flow control enable:
1649 - Modem debug support:
1650 CONFIG_MODEM_SUPPORT_DEBUG
1652 Enables debugging stuff (char screen[1024], dbg())
1653 for modem support. Useful only with BDI2000.
1655 - Interrupt support (PPC):
1657 There are common interrupt_init() and timer_interrupt()
1658 for all PPC archs. interrupt_init() calls interrupt_init_cpu()
1659 for cpu specific initialization. interrupt_init_cpu()
1660 should set decrementer_count to appropriate value. If
1661 cpu resets decrementer automatically after interrupt
1662 (ppc4xx) it should set decrementer_count to zero.
1663 timer_interrupt() calls timer_interrupt_cpu() for cpu
1664 specific handling. If board has watchdog / status_led
1665 / other_activity_monitor it works automatically from
1666 general timer_interrupt().
1670 In the target system modem support is enabled when a
1671 specific key (key combination) is pressed during
1672 power-on. Otherwise U-Boot will boot normally
1673 (autoboot). The key_pressed() fuction is called from
1674 board_init(). Currently key_pressed() is a dummy
1675 function, returning 1 and thus enabling modem
1678 If there are no modem init strings in the
1679 environment, U-Boot proceed to autoboot; the
1680 previous output (banner, info printfs) will be
1683 See also: doc/README.Modem
1686 Configuration Settings:
1687 -----------------------
1689 - CFG_LONGHELP: Defined when you want long help messages included;
1690 undefine this when you're short of memory.
1692 - CFG_PROMPT: This is what U-Boot prints on the console to
1693 prompt for user input.
1695 - CFG_CBSIZE: Buffer size for input from the Console
1697 - CFG_PBSIZE: Buffer size for Console output
1699 - CFG_MAXARGS: max. Number of arguments accepted for monitor commands
1701 - CFG_BARGSIZE: Buffer size for Boot Arguments which are passed to
1702 the application (usually a Linux kernel) when it is
1705 - CFG_BAUDRATE_TABLE:
1706 List of legal baudrate settings for this board.
1708 - CFG_CONSOLE_INFO_QUIET
1709 Suppress display of console information at boot.
1711 - CFG_CONSOLE_IS_IN_ENV
1712 If the board specific function
1713 extern int overwrite_console (void);
1714 returns 1, the stdin, stderr and stdout are switched to the
1715 serial port, else the settings in the environment are used.
1717 - CFG_CONSOLE_OVERWRITE_ROUTINE
1718 Enable the call to overwrite_console().
1720 - CFG_CONSOLE_ENV_OVERWRITE
1721 Enable overwrite of previous console environment settings.
1723 - CFG_MEMTEST_START, CFG_MEMTEST_END:
1724 Begin and End addresses of the area used by the
1728 Enable an alternate, more extensive memory test.
1730 - CFG_MEMTEST_SCRATCH:
1731 Scratch address used by the alternate memory test
1732 You only need to set this if address zero isn't writeable
1734 - CFG_TFTP_LOADADDR:
1735 Default load address for network file downloads
1737 - CFG_LOADS_BAUD_CHANGE:
1738 Enable temporary baudrate change while serial download
1741 Physical start address of SDRAM. _Must_ be 0 here.
1744 Physical start address of Motherboard I/O (if using a
1748 Physical start address of Flash memory.
1751 Physical start address of boot monitor code (set by
1752 make config files to be same as the text base address
1753 (TEXT_BASE) used when linking) - same as
1754 CFG_FLASH_BASE when booting from flash.
1757 Size of memory reserved for monitor code, used to
1758 determine _at_compile_time_ (!) if the environment is
1759 embedded within the U-Boot image, or in a separate
1763 Size of DRAM reserved for malloc() use.
1766 Normally compressed uImages are limited to an
1767 uncompressed size of 8 MBytes. If this is not enough,
1768 you can define CFG_BOOTM_LEN in your board config file
1769 to adjust this setting to your needs.
1772 Maximum size of memory mapped by the startup code of
1773 the Linux kernel; all data that must be processed by
1774 the Linux kernel (bd_info, boot arguments, eventually
1775 initrd image) must be put below this limit.
1777 - CFG_MAX_FLASH_BANKS:
1778 Max number of Flash memory banks
1780 - CFG_MAX_FLASH_SECT:
1781 Max number of sectors on a Flash chip
1783 - CFG_FLASH_ERASE_TOUT:
1784 Timeout for Flash erase operations (in ms)
1786 - CFG_FLASH_WRITE_TOUT:
1787 Timeout for Flash write operations (in ms)
1789 - CFG_FLASH_LOCK_TOUT
1790 Timeout for Flash set sector lock bit operation (in ms)
1792 - CFG_FLASH_UNLOCK_TOUT
1793 Timeout for Flash clear lock bits operation (in ms)
1795 - CFG_FLASH_PROTECTION
1796 If defined, hardware flash sectors protection is used
1797 instead of U-Boot software protection.
1799 - CFG_DIRECT_FLASH_TFTP:
1801 Enable TFTP transfers directly to flash memory;
1802 without this option such a download has to be
1803 performed in two steps: (1) download to RAM, and (2)
1804 copy from RAM to flash.
1806 The two-step approach is usually more reliable, since
1807 you can check if the download worked before you erase
1808 the flash, but in some situations (when sytem RAM is
1809 too limited to allow for a tempory copy of the
1810 downloaded image) this option may be very useful.
1813 Define if the flash driver uses extra elements in the
1814 common flash structure for storing flash geometry.
1816 - CFG_FLASH_CFI_DRIVER
1817 This option also enables the building of the cfi_flash driver
1818 in the drivers directory
1820 - CFG_FLASH_QUIET_TEST
1821 If this option is defined, the common CFI flash doesn't
1822 print it's warning upon not recognized FLASH banks. This
1823 is useful, if some of the configured banks are only
1824 optionally available.
1826 - CFG_RX_ETH_BUFFER:
1827 Defines the number of ethernet receive buffers. On some
1828 ethernet controllers it is recommended to set this value
1829 to 8 or even higher (EEPRO100 or 405 EMAC), since all
1830 buffers can be full shortly after enabling the interface
1831 on high ethernet traffic.
1832 Defaults to 4 if not defined.
1834 The following definitions that deal with the placement and management
1835 of environment data (variable area); in general, we support the
1836 following configurations:
1838 - CFG_ENV_IS_IN_FLASH:
1840 Define this if the environment is in flash memory.
1842 a) The environment occupies one whole flash sector, which is
1843 "embedded" in the text segment with the U-Boot code. This
1844 happens usually with "bottom boot sector" or "top boot
1845 sector" type flash chips, which have several smaller
1846 sectors at the start or the end. For instance, such a
1847 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In
1848 such a case you would place the environment in one of the
1849 4 kB sectors - with U-Boot code before and after it. With
1850 "top boot sector" type flash chips, you would put the
1851 environment in one of the last sectors, leaving a gap
1852 between U-Boot and the environment.
1856 Offset of environment data (variable area) to the
1857 beginning of flash memory; for instance, with bottom boot
1858 type flash chips the second sector can be used: the offset
1859 for this sector is given here.
1861 CFG_ENV_OFFSET is used relative to CFG_FLASH_BASE.
1865 This is just another way to specify the start address of
1866 the flash sector containing the environment (instead of
1869 - CFG_ENV_SECT_SIZE:
1871 Size of the sector containing the environment.
1874 b) Sometimes flash chips have few, equal sized, BIG sectors.
1875 In such a case you don't want to spend a whole sector for
1880 If you use this in combination with CFG_ENV_IS_IN_FLASH
1881 and CFG_ENV_SECT_SIZE, you can specify to use only a part
1882 of this flash sector for the environment. This saves
1883 memory for the RAM copy of the environment.
1885 It may also save flash memory if you decide to use this
1886 when your environment is "embedded" within U-Boot code,
1887 since then the remainder of the flash sector could be used
1888 for U-Boot code. It should be pointed out that this is
1889 STRONGLY DISCOURAGED from a robustness point of view:
1890 updating the environment in flash makes it always
1891 necessary to erase the WHOLE sector. If something goes
1892 wrong before the contents has been restored from a copy in
1893 RAM, your target system will be dead.
1895 - CFG_ENV_ADDR_REDUND
1898 These settings describe a second storage area used to hold
1899 a redundand copy of the environment data, so that there is
1900 a valid backup copy in case there is a power failure during
1901 a "saveenv" operation.
1903 BE CAREFUL! Any changes to the flash layout, and some changes to the
1904 source code will make it necessary to adapt <board>/u-boot.lds*
1908 - CFG_ENV_IS_IN_NVRAM:
1910 Define this if you have some non-volatile memory device
1911 (NVRAM, battery buffered SRAM) which you want to use for the
1917 These two #defines are used to determin the memory area you
1918 want to use for environment. It is assumed that this memory
1919 can just be read and written to, without any special
1922 BE CAREFUL! The first access to the environment happens quite early
1923 in U-Boot initalization (when we try to get the setting of for the
1924 console baudrate). You *MUST* have mappend your NVRAM area then, or
1927 Please note that even with NVRAM we still use a copy of the
1928 environment in RAM: we could work on NVRAM directly, but we want to
1929 keep settings there always unmodified except somebody uses "saveenv"
1930 to save the current settings.
1933 - CFG_ENV_IS_IN_EEPROM:
1935 Use this if you have an EEPROM or similar serial access
1936 device and a driver for it.
1941 These two #defines specify the offset and size of the
1942 environment area within the total memory of your EEPROM.
1944 - CFG_I2C_EEPROM_ADDR:
1945 If defined, specified the chip address of the EEPROM device.
1946 The default address is zero.
1948 - CFG_EEPROM_PAGE_WRITE_BITS:
1949 If defined, the number of bits used to address bytes in a
1950 single page in the EEPROM device. A 64 byte page, for example
1951 would require six bits.
1953 - CFG_EEPROM_PAGE_WRITE_DELAY_MS:
1954 If defined, the number of milliseconds to delay between
1955 page writes. The default is zero milliseconds.
1957 - CFG_I2C_EEPROM_ADDR_LEN:
1958 The length in bytes of the EEPROM memory array address. Note
1959 that this is NOT the chip address length!
1961 - CFG_I2C_EEPROM_ADDR_OVERFLOW:
1962 EEPROM chips that implement "address overflow" are ones
1963 like Catalyst 24WC04/08/16 which has 9/10/11 bits of
1964 address and the extra bits end up in the "chip address" bit
1965 slots. This makes a 24WC08 (1Kbyte) chip look like four 256
1968 Note that we consider the length of the address field to
1969 still be one byte because the extra address bits are hidden
1970 in the chip address.
1973 The size in bytes of the EEPROM device.
1976 - CFG_ENV_IS_IN_DATAFLASH:
1978 Define this if you have a DataFlash memory device which you
1979 want to use for the environment.
1985 These three #defines specify the offset and size of the
1986 environment area within the total memory of your DataFlash placed
1987 at the specified address.
1989 - CFG_ENV_IS_IN_NAND:
1991 Define this if you have a NAND device which you want to use
1992 for the environment.
1997 These two #defines specify the offset and size of the environment
1998 area within the first NAND device.
2000 - CFG_ENV_OFFSET_REDUND
2002 This setting describes a second storage area of CFG_ENV_SIZE
2003 size used to hold a redundant copy of the environment data,
2004 so that there is a valid backup copy in case there is a
2005 power failure during a "saveenv" operation.
2007 Note: CFG_ENV_OFFSET and CFG_ENV_OFFSET_REDUND must be aligned
2008 to a block boundary, and CFG_ENV_SIZE must be a multiple of
2009 the NAND devices block size.
2011 - CFG_SPI_INIT_OFFSET
2013 Defines offset to the initial SPI buffer area in DPRAM. The
2014 area is used at an early stage (ROM part) if the environment
2015 is configured to reside in the SPI EEPROM: We need a 520 byte
2016 scratch DPRAM area. It is used between the two initialization
2017 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems
2018 to be a good choice since it makes it far enough from the
2019 start of the data area as well as from the stack pointer.
2021 Please note that the environment is read-only as long as the monitor
2022 has been relocated to RAM and a RAM copy of the environment has been
2023 created; also, when using EEPROM you will have to use getenv_r()
2024 until then to read environment variables.
2026 The environment is protected by a CRC32 checksum. Before the monitor
2027 is relocated into RAM, as a result of a bad CRC you will be working
2028 with the compiled-in default environment - *silently*!!! [This is
2029 necessary, because the first environment variable we need is the
2030 "baudrate" setting for the console - if we have a bad CRC, we don't
2031 have any device yet where we could complain.]
2033 Note: once the monitor has been relocated, then it will complain if
2034 the default environment is used; a new CRC is computed as soon as you
2035 use the "saveenv" command to store a valid environment.
2037 - CFG_FAULT_ECHO_LINK_DOWN:
2038 Echo the inverted Ethernet link state to the fault LED.
2040 Note: If this option is active, then CFG_FAULT_MII_ADDR
2041 also needs to be defined.
2043 - CFG_FAULT_MII_ADDR:
2044 MII address of the PHY to check for the Ethernet link state.
2046 - CFG_64BIT_VSPRINTF:
2047 Makes vsprintf (and all *printf functions) support printing
2048 of 64bit values by using the L quantifier
2050 - CFG_64BIT_STRTOUL:
2051 Adds simple_strtoull that returns a 64bit value
2053 Low Level (hardware related) configuration options:
2054 ---------------------------------------------------
2056 - CFG_CACHELINE_SIZE:
2057 Cache Line Size of the CPU.
2060 Default address of the IMMR after system reset.
2062 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU,
2063 and RPXsuper) to be able to adjust the position of
2064 the IMMR register after a reset.
2066 - Floppy Disk Support:
2067 CFG_FDC_DRIVE_NUMBER
2069 the default drive number (default value 0)
2073 defines the spacing between fdc chipset registers
2078 defines the offset of register from address. It
2079 depends on which part of the data bus is connected to
2080 the fdc chipset. (default value 0)
2082 If CFG_ISA_IO_STRIDE CFG_ISA_IO_OFFSET and
2083 CFG_FDC_DRIVE_NUMBER are undefined, they take their
2086 if CFG_FDC_HW_INIT is defined, then the function
2087 fdc_hw_init() is called at the beginning of the FDC
2088 setup. fdc_hw_init() must be provided by the board
2089 source code. It is used to make hardware dependant
2092 - CFG_IMMR: Physical address of the Internal Memory.
2093 DO NOT CHANGE unless you know exactly what you're
2094 doing! (11-4) [MPC8xx/82xx systems only]
2096 - CFG_INIT_RAM_ADDR:
2098 Start address of memory area that can be used for
2099 initial data and stack; please note that this must be
2100 writable memory that is working WITHOUT special
2101 initialization, i. e. you CANNOT use normal RAM which
2102 will become available only after programming the
2103 memory controller and running certain initialization
2106 U-Boot uses the following memory types:
2107 - MPC8xx and MPC8260: IMMR (internal memory of the CPU)
2108 - MPC824X: data cache
2109 - PPC4xx: data cache
2111 - CFG_GBL_DATA_OFFSET:
2113 Offset of the initial data structure in the memory
2114 area defined by CFG_INIT_RAM_ADDR. Usually
2115 CFG_GBL_DATA_OFFSET is chosen such that the initial
2116 data is located at the end of the available space
2117 (sometimes written as (CFG_INIT_RAM_END -
2118 CFG_INIT_DATA_SIZE), and the initial stack is just
2119 below that area (growing from (CFG_INIT_RAM_ADDR +
2120 CFG_GBL_DATA_OFFSET) downward.
2123 On the MPC824X (or other systems that use the data
2124 cache for initial memory) the address chosen for
2125 CFG_INIT_RAM_ADDR is basically arbitrary - it must
2126 point to an otherwise UNUSED address space between
2127 the top of RAM and the start of the PCI space.
2129 - CFG_SIUMCR: SIU Module Configuration (11-6)
2131 - CFG_SYPCR: System Protection Control (11-9)
2133 - CFG_TBSCR: Time Base Status and Control (11-26)
2135 - CFG_PISCR: Periodic Interrupt Status and Control (11-31)
2137 - CFG_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30)
2139 - CFG_SCCR: System Clock and reset Control Register (15-27)
2141 - CFG_OR_TIMING_SDRAM:
2145 periodic timer for refresh
2147 - CFG_DER: Debug Event Register (37-47)
2149 - FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CFG_REMAP_OR_AM,
2150 CFG_PRELIM_OR_AM, CFG_OR_TIMING_FLASH, CFG_OR0_REMAP,
2151 CFG_OR0_PRELIM, CFG_BR0_PRELIM, CFG_OR1_REMAP, CFG_OR1_PRELIM,
2153 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
2155 - SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
2156 CFG_OR_TIMING_SDRAM, CFG_OR2_PRELIM, CFG_BR2_PRELIM,
2157 CFG_OR3_PRELIM, CFG_BR3_PRELIM:
2158 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
2160 - CFG_MAMR_PTA, CFG_MPTPR_2BK_4K, CFG_MPTPR_1BK_4K, CFG_MPTPR_2BK_8K,
2161 CFG_MPTPR_1BK_8K, CFG_MAMR_8COL, CFG_MAMR_9COL:
2162 Machine Mode Register and Memory Periodic Timer
2163 Prescaler definitions (SDRAM timing)
2165 - CFG_I2C_UCODE_PATCH, CFG_I2C_DPMEM_OFFSET [0x1FC0]:
2166 enable I2C microcode relocation patch (MPC8xx);
2167 define relocation offset in DPRAM [DSP2]
2169 - CFG_SPI_UCODE_PATCH, CFG_SPI_DPMEM_OFFSET [0x1FC0]:
2170 enable SPI microcode relocation patch (MPC8xx);
2171 define relocation offset in DPRAM [SCC4]
2174 Use OSCM clock mode on MBX8xx board. Be careful,
2175 wrong setting might damage your board. Read
2176 doc/README.MBX before setting this variable!
2178 - CFG_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only)
2179 Offset of the bootmode word in DPRAM used by post
2180 (Power On Self Tests). This definition overrides
2181 #define'd default value in commproc.h resp.
2184 - CFG_PCI_SLV_MEM_LOCAL, CFG_PCI_SLV_MEM_BUS, CFG_PICMR0_MASK_ATTRIB,
2185 CFG_PCI_MSTR0_LOCAL, CFG_PCIMSK0_MASK, CFG_PCI_MSTR1_LOCAL,
2186 CFG_PCIMSK1_MASK, CFG_PCI_MSTR_MEM_LOCAL, CFG_PCI_MSTR_MEM_BUS,
2187 CFG_CPU_PCI_MEM_START, CFG_PCI_MSTR_MEM_SIZE, CFG_POCMR0_MASK_ATTRIB,
2188 CFG_PCI_MSTR_MEMIO_LOCAL, CFG_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START,
2189 CFG_PCI_MSTR_MEMIO_SIZE, CFG_POCMR1_MASK_ATTRIB, CFG_PCI_MSTR_IO_LOCAL,
2190 CFG_PCI_MSTR_IO_BUS, CFG_CPU_PCI_IO_START, CFG_PCI_MSTR_IO_SIZE,
2191 CFG_POCMR2_MASK_ATTRIB: (MPC826x only)
2192 Overrides the default PCI memory map in cpu/mpc8260/pci.c if set.
2194 - CONFIG_ETHER_ON_FEC[12]
2195 Define to enable FEC[12] on a 8xx series processor.
2197 - CONFIG_FEC[12]_PHY
2198 Define to the hardcoded PHY address which corresponds
2199 to the given FEC; i. e.
2200 #define CONFIG_FEC1_PHY 4
2201 means that the PHY with address 4 is connected to FEC1
2203 When set to -1, means to probe for first available.
2205 - CONFIG_FEC[12]_PHY_NORXERR
2206 The PHY does not have a RXERR line (RMII only).
2207 (so program the FEC to ignore it).
2210 Enable RMII mode for all FECs.
2211 Note that this is a global option, we can't
2212 have one FEC in standard MII mode and another in RMII mode.
2214 - CONFIG_CRC32_VERIFY
2215 Add a verify option to the crc32 command.
2218 => crc32 -v <address> <count> <crc32>
2220 Where address/count indicate a memory area
2221 and crc32 is the correct crc32 which the
2225 Add the "loopw" memory command. This only takes effect if
2226 the memory commands are activated globally (CFG_CMD_MEM).
2229 Add the "mdc" and "mwc" memory commands. These are cyclic
2234 This command will print 4 bytes (10,11,12,13) each 500 ms.
2236 => mwc.l 100 12345678 10
2237 This command will write 12345678 to address 100 all 10 ms.
2239 This only takes effect if the memory commands are activated
2240 globally (CFG_CMD_MEM).
2242 - CONFIG_SKIP_LOWLEVEL_INIT
2243 - CONFIG_SKIP_RELOCATE_UBOOT
2245 [ARM only] If these variables are defined, then
2246 certain low level initializations (like setting up
2247 the memory controller) are omitted and/or U-Boot does
2248 not relocate itself into RAM.
2249 Normally these variables MUST NOT be defined. The
2250 only exception is when U-Boot is loaded (to RAM) by
2251 some other boot loader or by a debugger which
2252 performs these intializations itself.
2255 Building the Software:
2256 ======================
2258 Building U-Boot has been tested in native PPC environments (on a
2259 PowerBook G3 running LinuxPPC 2000) and in cross environments
2260 (running RedHat 6.x and 7.x Linux on x86, Solaris 2.6 on a SPARC, and
2263 If you are not using a native PPC environment, it is assumed that you
2264 have the GNU cross compiling tools available in your path and named
2265 with a prefix of "powerpc-linux-". If this is not the case, (e.g. if
2266 you are using Monta Vista's Hard Hat Linux CDK 1.2) you must change
2267 the definition of CROSS_COMPILE in Makefile. For HHL on a 4xx CPU,
2270 CROSS_COMPILE = ppc_4xx-
2273 U-Boot is intended to be simple to build. After installing the
2274 sources you must configure U-Boot for one specific board type. This
2279 where "NAME_config" is the name of one of the existing
2280 configurations; the following names are supported:
2282 ADCIOP_config FPS860L_config omap730p2_config
2283 ADS860_config GEN860T_config pcu_e_config
2285 AR405_config GENIETV_config PIP405_config
2286 at91rm9200dk_config GTH_config QS823_config
2287 CANBT_config hermes_config QS850_config
2288 cmi_mpc5xx_config hymod_config QS860T_config
2289 cogent_common_config IP860_config RPXlite_config
2290 cogent_mpc8260_config IVML24_config RPXlite_DW_config
2291 cogent_mpc8xx_config IVMS8_config RPXsuper_config
2292 CPCI405_config JSE_config rsdproto_config
2293 CPCIISER4_config LANTEC_config Sandpoint8240_config
2294 csb272_config lwmon_config sbc8260_config
2295 CU824_config MBX860T_config sbc8560_33_config
2296 DUET_ADS_config MBX_config sbc8560_66_config
2297 EBONY_config MPC8260ADS_config SM850_config
2298 ELPT860_config MPC8540ADS_config SPD823TS_config
2299 ESTEEM192E_config MPC8540EVAL_config stxgp3_config
2300 ETX094_config MPC8560ADS_config SXNI855T_config
2301 FADS823_config NETVIA_config TQM823L_config
2302 FADS850SAR_config omap1510inn_config TQM850L_config
2303 FADS860T_config omap1610h2_config TQM855L_config
2304 FPS850L_config omap1610inn_config TQM860L_config
2305 omap5912osk_config walnut_config
2306 omap2420h4_config Yukon8220_config
2309 Note: for some board special configuration names may exist; check if
2310 additional information is available from the board vendor; for
2311 instance, the TQM823L systems are available without (standard)
2312 or with LCD support. You can select such additional "features"
2313 when chosing the configuration, i. e.
2316 - will configure for a plain TQM823L, i. e. no LCD support
2318 make TQM823L_LCD_config
2319 - will configure for a TQM823L with U-Boot console on LCD
2324 Finally, type "make all", and you should get some working U-Boot
2325 images ready for download to / installation on your system:
2327 - "u-boot.bin" is a raw binary image
2328 - "u-boot" is an image in ELF binary format
2329 - "u-boot.srec" is in Motorola S-Record format
2331 By default the build is performed locally and the objects are saved
2332 in the source directory. One of the two methods can be used to change
2333 this behavior and build U-Boot to some external directory:
2335 1. Add O= to the make command line invocations:
2337 make O=/tmp/build distclean
2338 make O=/tmp/build NAME_config
2339 make O=/tmp/build all
2341 2. Set environment variable BUILD_DIR to point to the desired location:
2343 export BUILD_DIR=/tmp/build
2348 Note that the command line "O=" setting overrides the BUILD_DIR environment
2352 Please be aware that the Makefiles assume you are using GNU make, so
2353 for instance on NetBSD you might need to use "gmake" instead of
2357 If the system board that you have is not listed, then you will need
2358 to port U-Boot to your hardware platform. To do this, follow these
2361 1. Add a new configuration option for your board to the toplevel
2362 "Makefile" and to the "MAKEALL" script, using the existing
2363 entries as examples. Note that here and at many other places
2364 boards and other names are listed in alphabetical sort order. Please
2366 2. Create a new directory to hold your board specific code. Add any
2367 files you need. In your board directory, you will need at least
2368 the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds".
2369 3. Create a new configuration file "include/configs/<board>.h" for
2371 3. If you're porting U-Boot to a new CPU, then also create a new
2372 directory to hold your CPU specific code. Add any files you need.
2373 4. Run "make <board>_config" with your new name.
2374 5. Type "make", and you should get a working "u-boot.srec" file
2375 to be installed on your target system.
2376 6. Debug and solve any problems that might arise.
2377 [Of course, this last step is much harder than it sounds.]
2380 Testing of U-Boot Modifications, Ports to New Hardware, etc.:
2381 ==============================================================
2383 If you have modified U-Boot sources (for instance added a new board
2384 or support for new devices, a new CPU, etc.) you are expected to
2385 provide feedback to the other developers. The feedback normally takes
2386 the form of a "patch", i. e. a context diff against a certain (latest
2387 official or latest in CVS) version of U-Boot sources.
2389 But before you submit such a patch, please verify that your modifi-
2390 cation did not break existing code. At least make sure that *ALL* of
2391 the supported boards compile WITHOUT ANY compiler warnings. To do so,
2392 just run the "MAKEALL" script, which will configure and build U-Boot
2393 for ALL supported system. Be warned, this will take a while. You can
2394 select which (cross) compiler to use by passing a `CROSS_COMPILE'
2395 environment variable to the script, i. e. to use the cross tools from
2396 MontaVista's Hard Hat Linux you can type
2398 CROSS_COMPILE=ppc_8xx- MAKEALL
2400 or to build on a native PowerPC system you can type
2402 CROSS_COMPILE=' ' MAKEALL
2404 When using the MAKEALL script, the default behaviour is to build U-Boot
2405 in the source directory. This location can be changed by setting the
2406 BUILD_DIR environment variable. Also, for each target built, the MAKEALL
2407 script saves two log files (<target>.ERR and <target>.MAKEALL) in the
2408 <source dir>/LOG directory. This default location can be changed by
2409 setting the MAKEALL_LOGDIR environment variable. For example:
2411 export BUILD_DIR=/tmp/build
2412 export MAKEALL_LOGDIR=/tmp/log
2413 CROSS_COMPILE=ppc_8xx- MAKEALL
2415 With the above settings build objects are saved in the /tmp/build, log
2416 files are saved in the /tmp/log and the source tree remains clean during
2417 the whole build process.
2420 See also "U-Boot Porting Guide" below.
2423 Monitor Commands - Overview:
2424 ============================
2426 go - start application at address 'addr'
2427 run - run commands in an environment variable
2428 bootm - boot application image from memory
2429 bootp - boot image via network using BootP/TFTP protocol
2430 tftpboot- boot image via network using TFTP protocol
2431 and env variables "ipaddr" and "serverip"
2432 (and eventually "gatewayip")
2433 rarpboot- boot image via network using RARP/TFTP protocol
2434 diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
2435 loads - load S-Record file over serial line
2436 loadb - load binary file over serial line (kermit mode)
2438 mm - memory modify (auto-incrementing)
2439 nm - memory modify (constant address)
2440 mw - memory write (fill)
2442 cmp - memory compare
2443 crc32 - checksum calculation
2444 imd - i2c memory display
2445 imm - i2c memory modify (auto-incrementing)
2446 inm - i2c memory modify (constant address)
2447 imw - i2c memory write (fill)
2448 icrc32 - i2c checksum calculation
2449 iprobe - probe to discover valid I2C chip addresses
2450 iloop - infinite loop on address range
2451 isdram - print SDRAM configuration information
2452 sspi - SPI utility commands
2453 base - print or set address offset
2454 printenv- print environment variables
2455 setenv - set environment variables
2456 saveenv - save environment variables to persistent storage
2457 protect - enable or disable FLASH write protection
2458 erase - erase FLASH memory
2459 flinfo - print FLASH memory information
2460 bdinfo - print Board Info structure
2461 iminfo - print header information for application image
2462 coninfo - print console devices and informations
2463 ide - IDE sub-system
2464 loop - infinite loop on address range
2465 loopw - infinite write loop on address range
2466 mtest - simple RAM test
2467 icache - enable or disable instruction cache
2468 dcache - enable or disable data cache
2469 reset - Perform RESET of the CPU
2470 echo - echo args to console
2471 version - print monitor version
2472 help - print online help
2473 ? - alias for 'help'
2476 Monitor Commands - Detailed Description:
2477 ========================================
2481 For now: just type "help <command>".
2484 Environment Variables:
2485 ======================
2487 U-Boot supports user configuration using Environment Variables which
2488 can be made persistent by saving to Flash memory.
2490 Environment Variables are set using "setenv", printed using
2491 "printenv", and saved to Flash using "saveenv". Using "setenv"
2492 without a value can be used to delete a variable from the
2493 environment. As long as you don't save the environment you are
2494 working with an in-memory copy. In case the Flash area containing the
2495 environment is erased by accident, a default environment is provided.
2497 Some configuration options can be set using Environment Variables:
2499 baudrate - see CONFIG_BAUDRATE
2501 bootdelay - see CONFIG_BOOTDELAY
2503 bootcmd - see CONFIG_BOOTCOMMAND
2505 bootargs - Boot arguments when booting an RTOS image
2507 bootfile - Name of the image to load with TFTP
2509 autoload - if set to "no" (any string beginning with 'n'),
2510 "bootp" will just load perform a lookup of the
2511 configuration from the BOOTP server, but not try to
2512 load any image using TFTP
2514 autostart - if set to "yes", an image loaded using the "bootp",
2515 "rarpboot", "tftpboot" or "diskboot" commands will
2516 be automatically started (by internally calling
2519 If set to "no", a standalone image passed to the
2520 "bootm" command will be copied to the load address
2521 (and eventually uncompressed), but NOT be started.
2522 This can be used to load and uncompress arbitrary
2525 i2cfast - (PPC405GP|PPC405EP only)
2526 if set to 'y' configures Linux I2C driver for fast
2527 mode (400kHZ). This environment variable is used in
2528 initialization code. So, for changes to be effective
2529 it must be saved and board must be reset.
2531 initrd_high - restrict positioning of initrd images:
2532 If this variable is not set, initrd images will be
2533 copied to the highest possible address in RAM; this
2534 is usually what you want since it allows for
2535 maximum initrd size. If for some reason you want to
2536 make sure that the initrd image is loaded below the
2537 CFG_BOOTMAPSZ limit, you can set this environment
2538 variable to a value of "no" or "off" or "0".
2539 Alternatively, you can set it to a maximum upper
2540 address to use (U-Boot will still check that it
2541 does not overwrite the U-Boot stack and data).
2543 For instance, when you have a system with 16 MB
2544 RAM, and want to reserve 4 MB from use by Linux,
2545 you can do this by adding "mem=12M" to the value of
2546 the "bootargs" variable. However, now you must make
2547 sure that the initrd image is placed in the first
2548 12 MB as well - this can be done with
2550 setenv initrd_high 00c00000
2552 If you set initrd_high to 0xFFFFFFFF, this is an
2553 indication to U-Boot that all addresses are legal
2554 for the Linux kernel, including addresses in flash
2555 memory. In this case U-Boot will NOT COPY the
2556 ramdisk at all. This may be useful to reduce the
2557 boot time on your system, but requires that this
2558 feature is supported by your Linux kernel.
2560 ipaddr - IP address; needed for tftpboot command
2562 loadaddr - Default load address for commands like "bootp",
2563 "rarpboot", "tftpboot", "loadb" or "diskboot"
2565 loads_echo - see CONFIG_LOADS_ECHO
2567 serverip - TFTP server IP address; needed for tftpboot command
2569 bootretry - see CONFIG_BOOT_RETRY_TIME
2571 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
2573 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
2575 ethprime - When CONFIG_NET_MULTI is enabled controls which
2576 interface is used first.
2578 ethact - When CONFIG_NET_MULTI is enabled controls which
2579 interface is currently active. For example you
2580 can do the following
2582 => setenv ethact FEC ETHERNET
2583 => ping 192.168.0.1 # traffic sent on FEC ETHERNET
2584 => setenv ethact SCC ETHERNET
2585 => ping 10.0.0.1 # traffic sent on SCC ETHERNET
2587 netretry - When set to "no" each network operation will
2588 either succeed or fail without retrying.
2589 When set to "once" the network operation will
2590 fail when all the available network interfaces
2591 are tried once without success.
2592 Useful on scripts which control the retry operation
2595 tftpsrcport - If this is set, the value is used for TFTP's
2598 tftpdstport - If this is set, the value is used for TFTP's UDP
2599 destination port instead of the Well Know Port 69.
2601 vlan - When set to a value < 4095 the traffic over
2602 ethernet is encapsulated/received over 802.1q
2605 The following environment variables may be used and automatically
2606 updated by the network boot commands ("bootp" and "rarpboot"),
2607 depending the information provided by your boot server:
2609 bootfile - see above
2610 dnsip - IP address of your Domain Name Server
2611 dnsip2 - IP address of your secondary Domain Name Server
2612 gatewayip - IP address of the Gateway (Router) to use
2613 hostname - Target hostname
2615 netmask - Subnet Mask
2616 rootpath - Pathname of the root filesystem on the NFS server
2617 serverip - see above
2620 There are two special Environment Variables:
2622 serial# - contains hardware identification information such
2623 as type string and/or serial number
2624 ethaddr - Ethernet address
2626 These variables can be set only once (usually during manufacturing of
2627 the board). U-Boot refuses to delete or overwrite these variables
2628 once they have been set once.
2631 Further special Environment Variables:
2633 ver - Contains the U-Boot version string as printed
2634 with the "version" command. This variable is
2635 readonly (see CONFIG_VERSION_VARIABLE).
2638 Please note that changes to some configuration parameters may take
2639 only effect after the next boot (yes, that's just like Windoze :-).
2642 Command Line Parsing:
2643 =====================
2645 There are two different command line parsers available with U-Boot:
2646 the old "simple" one, and the much more powerful "hush" shell:
2648 Old, simple command line parser:
2649 --------------------------------
2651 - supports environment variables (through setenv / saveenv commands)
2652 - several commands on one line, separated by ';'
2653 - variable substitution using "... ${name} ..." syntax
2654 - special characters ('$', ';') can be escaped by prefixing with '\',
2656 setenv bootcmd bootm \${address}
2657 - You can also escape text by enclosing in single apostrophes, for example:
2658 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
2663 - similar to Bourne shell, with control structures like
2664 if...then...else...fi, for...do...done; while...do...done,
2665 until...do...done, ...
2666 - supports environment ("global") variables (through setenv / saveenv
2667 commands) and local shell variables (through standard shell syntax
2668 "name=value"); only environment variables can be used with "run"
2674 (1) If a command line (or an environment variable executed by a "run"
2675 command) contains several commands separated by semicolon, and
2676 one of these commands fails, then the remaining commands will be
2679 (2) If you execute several variables with one call to run (i. e.
2680 calling run with a list af variables as arguments), any failing
2681 command will cause "run" to terminate, i. e. the remaining
2682 variables are not executed.
2684 Note for Redundant Ethernet Interfaces:
2685 =======================================
2687 Some boards come with redundant ethernet interfaces; U-Boot supports
2688 such configurations and is capable of automatic selection of a
2689 "working" interface when needed. MAC assignment works as follows:
2691 Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
2692 MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
2693 "eth1addr" (=>eth1), "eth2addr", ...
2695 If the network interface stores some valid MAC address (for instance
2696 in SROM), this is used as default address if there is NO correspon-
2697 ding setting in the environment; if the corresponding environment
2698 variable is set, this overrides the settings in the card; that means:
2700 o If the SROM has a valid MAC address, and there is no address in the
2701 environment, the SROM's address is used.
2703 o If there is no valid address in the SROM, and a definition in the
2704 environment exists, then the value from the environment variable is
2707 o If both the SROM and the environment contain a MAC address, and
2708 both addresses are the same, this MAC address is used.
2710 o If both the SROM and the environment contain a MAC address, and the
2711 addresses differ, the value from the environment is used and a
2714 o If neither SROM nor the environment contain a MAC address, an error
2721 The "boot" commands of this monitor operate on "image" files which
2722 can be basicly anything, preceeded by a special header; see the
2723 definitions in include/image.h for details; basicly, the header
2724 defines the following image properties:
2726 * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
2727 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
2728 LynxOS, pSOS, QNX, RTEMS, ARTOS;
2729 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, ARTOS, LynxOS).
2730 * Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86,
2731 IA64, MIPS, NIOS, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
2732 Currently supported: ARM, AVR32, Intel x86, MIPS, NIOS, PowerPC).
2733 * Compression Type (uncompressed, gzip, bzip2)
2739 The header is marked by a special Magic Number, and both the header
2740 and the data portions of the image are secured against corruption by
2747 Although U-Boot should support any OS or standalone application
2748 easily, the main focus has always been on Linux during the design of
2751 U-Boot includes many features that so far have been part of some
2752 special "boot loader" code within the Linux kernel. Also, any
2753 "initrd" images to be used are no longer part of one big Linux image;
2754 instead, kernel and "initrd" are separate images. This implementation
2755 serves several purposes:
2757 - the same features can be used for other OS or standalone
2758 applications (for instance: using compressed images to reduce the
2759 Flash memory footprint)
2761 - it becomes much easier to port new Linux kernel versions because
2762 lots of low-level, hardware dependent stuff are done by U-Boot
2764 - the same Linux kernel image can now be used with different "initrd"
2765 images; of course this also means that different kernel images can
2766 be run with the same "initrd". This makes testing easier (you don't
2767 have to build a new "zImage.initrd" Linux image when you just
2768 change a file in your "initrd"). Also, a field-upgrade of the
2769 software is easier now.
2775 Porting Linux to U-Boot based systems:
2776 ---------------------------------------
2778 U-Boot cannot save you from doing all the necessary modifications to
2779 configure the Linux device drivers for use with your target hardware
2780 (no, we don't intend to provide a full virtual machine interface to
2783 But now you can ignore ALL boot loader code (in arch/ppc/mbxboot).
2785 Just make sure your machine specific header file (for instance
2786 include/asm-ppc/tqm8xx.h) includes the same definition of the Board
2787 Information structure as we define in include/u-boot.h, and make
2788 sure that your definition of IMAP_ADDR uses the same value as your
2789 U-Boot configuration in CFG_IMMR.
2792 Configuring the Linux kernel:
2793 -----------------------------
2795 No specific requirements for U-Boot. Make sure you have some root
2796 device (initial ramdisk, NFS) for your target system.
2799 Building a Linux Image:
2800 -----------------------
2802 With U-Boot, "normal" build targets like "zImage" or "bzImage" are
2803 not used. If you use recent kernel source, a new build target
2804 "uImage" will exist which automatically builds an image usable by
2805 U-Boot. Most older kernels also have support for a "pImage" target,
2806 which was introduced for our predecessor project PPCBoot and uses a
2807 100% compatible format.
2816 The "uImage" build target uses a special tool (in 'tools/mkimage') to
2817 encapsulate a compressed Linux kernel image with header information,
2818 CRC32 checksum etc. for use with U-Boot. This is what we are doing:
2820 * build a standard "vmlinux" kernel image (in ELF binary format):
2822 * convert the kernel into a raw binary image:
2824 ${CROSS_COMPILE}-objcopy -O binary \
2825 -R .note -R .comment \
2826 -S vmlinux linux.bin
2828 * compress the binary image:
2832 * package compressed binary image for U-Boot:
2834 mkimage -A ppc -O linux -T kernel -C gzip \
2835 -a 0 -e 0 -n "Linux Kernel Image" \
2836 -d linux.bin.gz uImage
2839 The "mkimage" tool can also be used to create ramdisk images for use
2840 with U-Boot, either separated from the Linux kernel image, or
2841 combined into one file. "mkimage" encapsulates the images with a 64
2842 byte header containing information about target architecture,
2843 operating system, image type, compression method, entry points, time
2844 stamp, CRC32 checksums, etc.
2846 "mkimage" can be called in two ways: to verify existing images and
2847 print the header information, or to build new images.
2849 In the first form (with "-l" option) mkimage lists the information
2850 contained in the header of an existing U-Boot image; this includes
2851 checksum verification:
2853 tools/mkimage -l image
2854 -l ==> list image header information
2856 The second form (with "-d" option) is used to build a U-Boot image
2857 from a "data file" which is used as image payload:
2859 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
2860 -n name -d data_file image
2861 -A ==> set architecture to 'arch'
2862 -O ==> set operating system to 'os'
2863 -T ==> set image type to 'type'
2864 -C ==> set compression type 'comp'
2865 -a ==> set load address to 'addr' (hex)
2866 -e ==> set entry point to 'ep' (hex)
2867 -n ==> set image name to 'name'
2868 -d ==> use image data from 'datafile'
2870 Right now, all Linux kernels for PowerPC systems use the same load
2871 address (0x00000000), but the entry point address depends on the
2874 - 2.2.x kernels have the entry point at 0x0000000C,
2875 - 2.3.x and later kernels have the entry point at 0x00000000.
2877 So a typical call to build a U-Boot image would read:
2879 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
2880 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
2881 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux.gz \
2882 > examples/uImage.TQM850L
2883 Image Name: 2.4.4 kernel for TQM850L
2884 Created: Wed Jul 19 02:34:59 2000
2885 Image Type: PowerPC Linux Kernel Image (gzip compressed)
2886 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
2887 Load Address: 0x00000000
2888 Entry Point: 0x00000000
2890 To verify the contents of the image (or check for corruption):
2892 -> tools/mkimage -l examples/uImage.TQM850L
2893 Image Name: 2.4.4 kernel for TQM850L
2894 Created: Wed Jul 19 02:34:59 2000
2895 Image Type: PowerPC Linux Kernel Image (gzip compressed)
2896 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
2897 Load Address: 0x00000000
2898 Entry Point: 0x00000000
2900 NOTE: for embedded systems where boot time is critical you can trade
2901 speed for memory and install an UNCOMPRESSED image instead: this
2902 needs more space in Flash, but boots much faster since it does not
2903 need to be uncompressed:
2905 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux.gz
2906 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
2907 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
2908 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux \
2909 > examples/uImage.TQM850L-uncompressed
2910 Image Name: 2.4.4 kernel for TQM850L
2911 Created: Wed Jul 19 02:34:59 2000
2912 Image Type: PowerPC Linux Kernel Image (uncompressed)
2913 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
2914 Load Address: 0x00000000
2915 Entry Point: 0x00000000
2918 Similar you can build U-Boot images from a 'ramdisk.image.gz' file
2919 when your kernel is intended to use an initial ramdisk:
2921 -> tools/mkimage -n 'Simple Ramdisk Image' \
2922 > -A ppc -O linux -T ramdisk -C gzip \
2923 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
2924 Image Name: Simple Ramdisk Image
2925 Created: Wed Jan 12 14:01:50 2000
2926 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
2927 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
2928 Load Address: 0x00000000
2929 Entry Point: 0x00000000
2932 Installing a Linux Image:
2933 -------------------------
2935 To downloading a U-Boot image over the serial (console) interface,
2936 you must convert the image to S-Record format:
2938 objcopy -I binary -O srec examples/image examples/image.srec
2940 The 'objcopy' does not understand the information in the U-Boot
2941 image header, so the resulting S-Record file will be relative to
2942 address 0x00000000. To load it to a given address, you need to
2943 specify the target address as 'offset' parameter with the 'loads'
2946 Example: install the image to address 0x40100000 (which on the
2947 TQM8xxL is in the first Flash bank):
2949 => erase 40100000 401FFFFF
2955 ## Ready for S-Record download ...
2956 ~>examples/image.srec
2957 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
2959 15989 15990 15991 15992
2960 [file transfer complete]
2962 ## Start Addr = 0x00000000
2965 You can check the success of the download using the 'iminfo' command;
2966 this includes a checksum verification so you can be sure no data
2967 corruption happened:
2971 ## Checking Image at 40100000 ...
2972 Image Name: 2.2.13 for initrd on TQM850L
2973 Image Type: PowerPC Linux Kernel Image (gzip compressed)
2974 Data Size: 335725 Bytes = 327 kB = 0 MB
2975 Load Address: 00000000
2976 Entry Point: 0000000c
2977 Verifying Checksum ... OK
2983 The "bootm" command is used to boot an application that is stored in
2984 memory (RAM or Flash). In case of a Linux kernel image, the contents
2985 of the "bootargs" environment variable is passed to the kernel as
2986 parameters. You can check and modify this variable using the
2987 "printenv" and "setenv" commands:
2990 => printenv bootargs
2991 bootargs=root=/dev/ram
2993 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
2995 => printenv bootargs
2996 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
2999 ## Booting Linux kernel at 40020000 ...
3000 Image Name: 2.2.13 for NFS on TQM850L
3001 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3002 Data Size: 381681 Bytes = 372 kB = 0 MB
3003 Load Address: 00000000
3004 Entry Point: 0000000c
3005 Verifying Checksum ... OK
3006 Uncompressing Kernel Image ... OK
3007 Linux version 2.2.13 (
[email protected]) (gcc version 2.95.2 19991024 (release)) #1 Wed Jul 19 02:35:17 MEST 2000
3008 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
3009 time_init: decrementer frequency = 187500000/60
3010 Calibrating delay loop... 49.77 BogoMIPS
3011 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
3014 If you want to boot a Linux kernel with initial ram disk, you pass
3015 the memory addresses of both the kernel and the initrd image (PPBCOOT
3016 format!) to the "bootm" command:
3018 => imi 40100000 40200000
3020 ## Checking Image at 40100000 ...
3021 Image Name: 2.2.13 for initrd on TQM850L
3022 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3023 Data Size: 335725 Bytes = 327 kB = 0 MB
3024 Load Address: 00000000
3025 Entry Point: 0000000c
3026 Verifying Checksum ... OK
3028 ## Checking Image at 40200000 ...
3029 Image Name: Simple Ramdisk Image
3030 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
3031 Data Size: 566530 Bytes = 553 kB = 0 MB
3032 Load Address: 00000000
3033 Entry Point: 00000000
3034 Verifying Checksum ... OK
3036 => bootm 40100000 40200000
3037 ## Booting Linux kernel at 40100000 ...
3038 Image Name: 2.2.13 for initrd on TQM850L
3039 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3040 Data Size: 335725 Bytes = 327 kB = 0 MB
3041 Load Address: 00000000
3042 Entry Point: 0000000c
3043 Verifying Checksum ... OK
3044 Uncompressing Kernel Image ... OK
3045 ## Loading RAMDisk Image at 40200000 ...
3046 Image Name: Simple Ramdisk Image
3047 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
3048 Data Size: 566530 Bytes = 553 kB = 0 MB
3049 Load Address: 00000000
3050 Entry Point: 00000000
3051 Verifying Checksum ... OK
3052 Loading Ramdisk ... OK
3053 Linux version 2.2.13 (
[email protected]) (gcc version 2.95.2 19991024 (release)) #1 Wed Jul 19 02:32:08 MEST 2000
3054 Boot arguments: root=/dev/ram
3055 time_init: decrementer frequency = 187500000/60
3056 Calibrating delay loop... 49.77 BogoMIPS
3058 RAMDISK: Compressed image found at block 0
3059 VFS: Mounted root (ext2 filesystem).
3063 More About U-Boot Image Types:
3064 ------------------------------
3066 U-Boot supports the following image types:
3068 "Standalone Programs" are directly runnable in the environment
3069 provided by U-Boot; it is expected that (if they behave
3070 well) you can continue to work in U-Boot after return from
3071 the Standalone Program.
3072 "OS Kernel Images" are usually images of some Embedded OS which
3073 will take over control completely. Usually these programs
3074 will install their own set of exception handlers, device
3075 drivers, set up the MMU, etc. - this means, that you cannot
3076 expect to re-enter U-Boot except by resetting the CPU.
3077 "RAMDisk Images" are more or less just data blocks, and their
3078 parameters (address, size) are passed to an OS kernel that is
3080 "Multi-File Images" contain several images, typically an OS
3081 (Linux) kernel image and one or more data images like
3082 RAMDisks. This construct is useful for instance when you want
3083 to boot over the network using BOOTP etc., where the boot
3084 server provides just a single image file, but you want to get
3085 for instance an OS kernel and a RAMDisk image.
3087 "Multi-File Images" start with a list of image sizes, each
3088 image size (in bytes) specified by an "uint32_t" in network
3089 byte order. This list is terminated by an "(uint32_t)0".
3090 Immediately after the terminating 0 follow the images, one by
3091 one, all aligned on "uint32_t" boundaries (size rounded up to
3092 a multiple of 4 bytes).
3094 "Firmware Images" are binary images containing firmware (like
3095 U-Boot or FPGA images) which usually will be programmed to
3098 "Script files" are command sequences that will be executed by
3099 U-Boot's command interpreter; this feature is especially
3100 useful when you configure U-Boot to use a real shell (hush)
3101 as command interpreter.
3107 One of the features of U-Boot is that you can dynamically load and
3108 run "standalone" applications, which can use some resources of
3109 U-Boot like console I/O functions or interrupt services.
3111 Two simple examples are included with the sources:
3116 'examples/hello_world.c' contains a small "Hello World" Demo
3117 application; it is automatically compiled when you build U-Boot.
3118 It's configured to run at address 0x00040004, so you can play with it
3122 ## Ready for S-Record download ...
3123 ~>examples/hello_world.srec
3124 1 2 3 4 5 6 7 8 9 10 11 ...
3125 [file transfer complete]
3127 ## Start Addr = 0x00040004
3129 => go 40004 Hello World! This is a test.
3130 ## Starting application at 0x00040004 ...
3141 Hit any key to exit ...
3143 ## Application terminated, rc = 0x0
3145 Another example, which demonstrates how to register a CPM interrupt
3146 handler with the U-Boot code, can be found in 'examples/timer.c'.
3147 Here, a CPM timer is set up to generate an interrupt every second.
3148 The interrupt service routine is trivial, just printing a '.'
3149 character, but this is just a demo program. The application can be
3150 controlled by the following keys:
3152 ? - print current values og the CPM Timer registers
3153 b - enable interrupts and start timer
3154 e - stop timer and disable interrupts
3155 q - quit application
3158 ## Ready for S-Record download ...
3159 ~>examples/timer.srec
3160 1 2 3 4 5 6 7 8 9 10 11 ...
3161 [file transfer complete]
3163 ## Start Addr = 0x00040004
3166 ## Starting application at 0x00040004 ...
3169 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
3172 [q, b, e, ?] Set interval 1000000 us
3175 [q, b, e, ?] ........
3176 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
3179 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
3182 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
3185 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
3187 [q, b, e, ?] ...Stopping timer
3189 [q, b, e, ?] ## Application terminated, rc = 0x0
3195 Over time, many people have reported problems when trying to use the
3196 "minicom" terminal emulation program for serial download. I (wd)
3197 consider minicom to be broken, and recommend not to use it. Under
3198 Unix, I recommend to use C-Kermit for general purpose use (and
3199 especially for kermit binary protocol download ("loadb" command), and
3200 use "cu" for S-Record download ("loads" command).
3202 Nevertheless, if you absolutely want to use it try adding this
3203 configuration to your "File transfer protocols" section:
3205 Name Program Name U/D FullScr IO-Red. Multi
3206 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
3207 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
3213 Starting at version 0.9.2, U-Boot supports NetBSD both as host
3214 (build U-Boot) and target system (boots NetBSD/mpc8xx).
3216 Building requires a cross environment; it is known to work on
3217 NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
3218 need gmake since the Makefiles are not compatible with BSD make).
3219 Note that the cross-powerpc package does not install include files;
3220 attempting to build U-Boot will fail because <machine/ansi.h> is
3221 missing. This file has to be installed and patched manually:
3223 # cd /usr/pkg/cross/powerpc-netbsd/include
3225 # ln -s powerpc machine
3226 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
3227 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
3229 Native builds *don't* work due to incompatibilities between native
3230 and U-Boot include files.
3232 Booting assumes that (the first part of) the image booted is a
3233 stage-2 loader which in turn loads and then invokes the kernel
3234 proper. Loader sources will eventually appear in the NetBSD source
3235 tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
3236 meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz
3239 Implementation Internals:
3240 =========================
3242 The following is not intended to be a complete description of every
3243 implementation detail. However, it should help to understand the
3244 inner workings of U-Boot and make it easier to port it to custom
3248 Initial Stack, Global Data:
3249 ---------------------------
3251 The implementation of U-Boot is complicated by the fact that U-Boot
3252 starts running out of ROM (flash memory), usually without access to
3253 system RAM (because the memory controller is not initialized yet).
3254 This means that we don't have writable Data or BSS segments, and BSS
3255 is not initialized as zero. To be able to get a C environment working
3256 at all, we have to allocate at least a minimal stack. Implementation
3257 options for this are defined and restricted by the CPU used: Some CPU
3258 models provide on-chip memory (like the IMMR area on MPC8xx and
3259 MPC826x processors), on others (parts of) the data cache can be
3260 locked as (mis-) used as memory, etc.
3262 Chris Hallinan posted a good summary of these issues to the
3263 u-boot-users mailing list:
3265 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
3267 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
3270 Correct me if I'm wrong, folks, but the way I understand it
3271 is this: Using DCACHE as initial RAM for Stack, etc, does not
3272 require any physical RAM backing up the cache. The cleverness
3273 is that the cache is being used as a temporary supply of
3274 necessary storage before the SDRAM controller is setup. It's
3275 beyond the scope of this list to expain the details, but you
3276 can see how this works by studying the cache architecture and
3277 operation in the architecture and processor-specific manuals.
3279 OCM is On Chip Memory, which I believe the 405GP has 4K. It
3280 is another option for the system designer to use as an
3281 initial stack/ram area prior to SDRAM being available. Either
3282 option should work for you. Using CS 4 should be fine if your
3283 board designers haven't used it for something that would
3284 cause you grief during the initial boot! It is frequently not
3287 CFG_INIT_RAM_ADDR should be somewhere that won't interfere
3288 with your processor/board/system design. The default value
3289 you will find in any recent u-boot distribution in
3290 walnut.h should work for you. I'd set it to a value larger
3291 than your SDRAM module. If you have a 64MB SDRAM module, set
3292 it above 400_0000. Just make sure your board has no resources
3293 that are supposed to respond to that address! That code in
3294 start.S has been around a while and should work as is when
3295 you get the config right.
3300 It is essential to remember this, since it has some impact on the C
3301 code for the initialization procedures:
3303 * Initialized global data (data segment) is read-only. Do not attempt
3306 * Do not use any unitialized global data (or implicitely initialized
3307 as zero data - BSS segment) at all - this is undefined, initiali-
3308 zation is performed later (when relocating to RAM).
3310 * Stack space is very limited. Avoid big data buffers or things like
3313 Having only the stack as writable memory limits means we cannot use
3314 normal global data to share information beween the code. But it
3315 turned out that the implementation of U-Boot can be greatly
3316 simplified by making a global data structure (gd_t) available to all
3317 functions. We could pass a pointer to this data as argument to _all_
3318 functions, but this would bloat the code. Instead we use a feature of
3319 the GCC compiler (Global Register Variables) to share the data: we
3320 place a pointer (gd) to the global data into a register which we
3321 reserve for this purpose.
3323 When choosing a register for such a purpose we are restricted by the
3324 relevant (E)ABI specifications for the current architecture, and by
3325 GCC's implementation.
3327 For PowerPC, the following registers have specific use:
3330 R3-R4: parameter passing and return values
3331 R5-R10: parameter passing
3332 R13: small data area pointer
3336 (U-Boot also uses R14 as internal GOT pointer.)
3338 ==> U-Boot will use R29 to hold a pointer to the global data
3340 Note: on PPC, we could use a static initializer (since the
3341 address of the global data structure is known at compile time),
3342 but it turned out that reserving a register results in somewhat
3343 smaller code - although the code savings are not that big (on
3344 average for all boards 752 bytes for the whole U-Boot image,
3345 624 text + 127 data).
3347 On ARM, the following registers are used:
3349 R0: function argument word/integer result
3350 R1-R3: function argument word
3352 R10: stack limit (used only if stack checking if enabled)
3353 R11: argument (frame) pointer
3354 R12: temporary workspace
3357 R15: program counter
3359 ==> U-Boot will use R8 to hold a pointer to the global data
3361 NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope,
3362 or current versions of GCC may "optimize" the code too much.
3367 U-Boot runs in system state and uses physical addresses, i.e. the
3368 MMU is not used either for address mapping nor for memory protection.
3370 The available memory is mapped to fixed addresses using the memory
3371 controller. In this process, a contiguous block is formed for each
3372 memory type (Flash, SDRAM, SRAM), even when it consists of several
3373 physical memory banks.
3375 U-Boot is installed in the first 128 kB of the first Flash bank (on
3376 TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
3377 booting and sizing and initializing DRAM, the code relocates itself
3378 to the upper end of DRAM. Immediately below the U-Boot code some
3379 memory is reserved for use by malloc() [see CFG_MALLOC_LEN
3380 configuration setting]. Below that, a structure with global Board
3381 Info data is placed, followed by the stack (growing downward).
3383 Additionally, some exception handler code is copied to the low 8 kB
3384 of DRAM (0x00000000 ... 0x00001FFF).
3386 So a typical memory configuration with 16 MB of DRAM could look like
3389 0x0000 0000 Exception Vector code
3392 0x0000 2000 Free for Application Use
3398 0x00FB FF20 Monitor Stack (Growing downward)
3399 0x00FB FFAC Board Info Data and permanent copy of global data
3400 0x00FC 0000 Malloc Arena
3403 0x00FE 0000 RAM Copy of Monitor Code
3404 ... eventually: LCD or video framebuffer
3405 ... eventually: pRAM (Protected RAM - unchanged by reset)
3406 0x00FF FFFF [End of RAM]
3409 System Initialization:
3410 ----------------------
3412 In the reset configuration, U-Boot starts at the reset entry point
3413 (on most PowerPC systens at address 0x00000100). Because of the reset
3414 configuration for CS0# this is a mirror of the onboard Flash memory.
3415 To be able to re-map memory U-Boot then jumps to its link address.
3416 To be able to implement the initialization code in C, a (small!)
3417 initial stack is set up in the internal Dual Ported RAM (in case CPUs
3418 which provide such a feature like MPC8xx or MPC8260), or in a locked
3419 part of the data cache. After that, U-Boot initializes the CPU core,
3420 the caches and the SIU.
3422 Next, all (potentially) available memory banks are mapped using a
3423 preliminary mapping. For example, we put them on 512 MB boundaries
3424 (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
3425 on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
3426 programmed for SDRAM access. Using the temporary configuration, a
3427 simple memory test is run that determines the size of the SDRAM
3430 When there is more than one SDRAM bank, and the banks are of
3431 different size, the largest is mapped first. For equal size, the first
3432 bank (CS2#) is mapped first. The first mapping is always for address
3433 0x00000000, with any additional banks following immediately to create
3434 contiguous memory starting from 0.
3436 Then, the monitor installs itself at the upper end of the SDRAM area
3437 and allocates memory for use by malloc() and for the global Board
3438 Info data; also, the exception vector code is copied to the low RAM
3439 pages, and the final stack is set up.
3441 Only after this relocation will you have a "normal" C environment;
3442 until that you are restricted in several ways, mostly because you are
3443 running from ROM, and because the code will have to be relocated to a
3447 U-Boot Porting Guide:
3448 ----------------------
3450 [Based on messages by Jerry Van Baren in the U-Boot-Users mailing
3454 int main (int argc, char *argv[])
3456 sighandler_t no_more_time;
3458 signal (SIGALRM, no_more_time);
3459 alarm (PROJECT_DEADLINE - toSec (3 * WEEK));
3461 if (available_money > available_manpower) {
3462 pay consultant to port U-Boot;
3466 Download latest U-Boot source;
3468 Subscribe to u-boot-users mailing list;
3471 email ("Hi, I am new to U-Boot, how do I get started?");
3475 Read the README file in the top level directory;
3476 Read http://www.denx.de/twiki/bin/view/DULG/Manual ;
3477 Read the source, Luke;
3480 if (available_money > toLocalCurrency ($2500)) {
3483 Add a lot of aggravation and time;
3486 Create your own board support subdirectory;
3488 Create your own board config file;
3492 Add / modify source code;
3496 email ("Hi, I am having problems...");
3498 Send patch file to Wolfgang;
3503 void no_more_time (int sig)
3512 All contributions to U-Boot should conform to the Linux kernel
3513 coding style; see the file "Documentation/CodingStyle" and the script
3514 "scripts/Lindent" in your Linux kernel source directory. In sources
3515 originating from U-Boot a style corresponding to "Lindent -pcs" (adding
3516 spaces before parameters to function calls) is actually used.
3518 Source files originating from a different project (for example the
3519 MTD subsystem) are generally exempt from these guidelines and are not
3520 reformated to ease subsequent migration to newer versions of those
3523 Please note that U-Boot is implemented in C (and to some small parts in
3524 Assembler); no C++ is used, so please do not use C++ style comments (//)
3527 Please also stick to the following formatting rules:
3528 - remove any trailing white space
3529 - use TAB characters for indentation, not spaces
3530 - make sure NOT to use DOS '\r\n' line feeds
3531 - do not add more than 2 empty lines to source files
3532 - do not add trailing empty lines to source files
3534 Submissions which do not conform to the standards may be returned
3535 with a request to reformat the changes.
3541 Since the number of patches for U-Boot is growing, we need to
3542 establish some rules. Submissions which do not conform to these rules
3543 may be rejected, even when they contain important and valuable stuff.
3545 Patches shall be sent to the u-boot-users mailing list.
3547 When you send a patch, please include the following information with
3550 * For bug fixes: a description of the bug and how your patch fixes
3551 this bug. Please try to include a way of demonstrating that the
3552 patch actually fixes something.
3554 * For new features: a description of the feature and your
3557 * A CHANGELOG entry as plaintext (separate from the patch)
3559 * For major contributions, your entry to the CREDITS file
3561 * When you add support for a new board, don't forget to add this
3562 board to the MAKEALL script, too.
3564 * If your patch adds new configuration options, don't forget to
3565 document these in the README file.
3567 * The patch itself. If you are accessing the CVS repository use "cvs
3568 update; cvs diff -puRN"; else, use "diff -purN OLD NEW". If your
3569 version of diff does not support these options, then get the latest
3570 version of GNU diff.
3572 The current directory when running this command shall be the top
3573 level directory of the U-Boot source tree, or it's parent directory
3574 (i. e. please make sure that your patch includes sufficient
3575 directory information for the affected files).
3577 We accept patches as plain text, MIME attachments or as uuencoded
3580 * If one logical set of modifications affects or creates several
3581 files, all these changes shall be submitted in a SINGLE patch file.
3583 * Changesets that contain different, unrelated modifications shall be
3584 submitted as SEPARATE patches, one patch per changeset.
3589 * Before sending the patch, run the MAKEALL script on your patched
3590 source tree and make sure that no errors or warnings are reported
3591 for any of the boards.
3593 * Keep your modifications to the necessary minimum: A patch
3594 containing several unrelated changes or arbitrary reformats will be
3595 returned with a request to re-formatting / split it.
3597 * If you modify existing code, make sure that your new code does not
3598 add to the memory footprint of the code ;-) Small is beautiful!
3599 When adding new features, these should compile conditionally only
3600 (using #ifdef), and the resulting code with the new feature
3601 disabled must not need more memory than the old code without your
3604 * Remember that there is a size limit of 40 kB per message on the
3605 u-boot-users mailing list. Compression may help.
projects / J-u-boot.git / blob