2 # (C) Copyright 2000 - 2005
3 # Wolfgang Denk, DENX Software Engineering, wd@denx.de.
5 # See file CREDITS for list of people who contributed to this
8 # This program is free software; you can redistribute it and/or
9 # modify it under the terms of the GNU General Public License as
10 # published by the Free Software Foundation; either version 2 of
11 # the License, or (at your option) any later version.
13 # This program is distributed in the hope that it will be useful,
14 # but WITHOUT ANY WARRANTY; without even the implied warranty of
15 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 # GNU General Public License for more details.
18 # You should have received a copy of the GNU General Public License
19 # along with this program; if not, write to the Free Software
20 # Foundation, Inc., 59 Temple Place, Suite 330, Boston,
27 This directory contains the source code for U-Boot, a boot loader for
28 Embedded boards based on PowerPC, ARM, MIPS and several other
29 processors, which can be installed in a boot ROM and used to
30 initialize and test the hardware or to download and run application
33 The development of U-Boot is closely related to Linux: some parts of
34 the source code originate in the Linux source tree, we have some
35 header files in common, and special provision has been made to
36 support booting of Linux images.
38 Some attention has been paid to make this software easily
39 configurable and extendable. For instance, all monitor commands are
40 implemented with the same call interface, so that it's very easy to
41 add new commands. Also, instead of permanently adding rarely used
42 code (for instance hardware test utilities) to the monitor, you can
43 load and run it dynamically.
49 In general, all boards for which a configuration option exists in the
50 Makefile have been tested to some extent and can be considered
51 "working". In fact, many of them are used in production systems.
53 In case of problems see the CHANGELOG and CREDITS files to find out
54 who contributed the specific port.
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
62 <u-boot-users@lists.sourceforge.net>. There is also an archive of
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 - i386 Files specific to i386 CPUs
136 - ixp Files specific to Intel XScale IXP CPUs
137 - mcf52x2 Files specific to Freescale ColdFire MCF52x2 CPUs
138 - mips Files specific to MIPS CPUs
139 - mpc5xx Files specific to Freescale MPC5xx CPUs
140 - mpc5xxx Files specific to Freescale MPC5xxx CPUs
141 - mpc8xx Files specific to Freescale MPC8xx CPUs
142 - mpc8220 Files specific to Freescale MPC8220 CPUs
143 - mpc824x Files specific to Freescale MPC824x CPUs
144 - mpc8260 Files specific to Freescale MPC8260 CPUs
145 - mpc85xx Files specific to Freescale MPC85xx CPUs
146 - nios Files specific to Altera NIOS CPUs
147 - nios2 Files specific to Altera Nios-II CPUs
148 - ppc4xx Files specific to AMCC PowerPC 4xx CPUs
149 - pxa Files specific to Intel XScale PXA CPUs
150 - s3c44b0 Files specific to Samsung S3C44B0 CPUs
151 - sa1100 Files specific to Intel StrongARM SA1100 CPUs
152 - disk Code for disk drive partition handling
153 - doc Documentation (don't expect too much)
154 - drivers Commonly used device drivers
155 - dtt Digital Thermometer and Thermostat drivers
156 - examples Example code for standalone applications, etc.
157 - include Header Files
158 - lib_arm Files generic to ARM architecture
159 - lib_generic Files generic to all architectures
160 - lib_i386 Files generic to i386 architecture
161 - lib_m68k Files generic to m68k architecture
162 - lib_mips Files generic to MIPS architecture
163 - lib_nios Files generic to NIOS architecture
164 - lib_ppc Files generic to PowerPC architecture
165 - net Networking code
166 - post Power On Self Test
167 - rtc Real Time Clock drivers
168 - tools Tools to build S-Record or U-Boot images, etc.
170 Software Configuration:
171 =======================
173 Configuration is usually done using C preprocessor defines; the
174 rationale behind that is to avoid dead code whenever possible.
176 There are two classes of configuration variables:
178 * Configuration _OPTIONS_:
179 These are selectable by the user and have names beginning with
182 * Configuration _SETTINGS_:
183 These depend on the hardware etc. and should not be meddled with if
184 you don't know what you're doing; they have names beginning with
187 Later we will add a configuration tool - probably similar to or even
188 identical to what's used for the Linux kernel. Right now, we have to
189 do the configuration by hand, which means creating some symbolic
190 links and editing some configuration files. We use the TQM8xxL boards
194 Selection of Processor Architecture and Board Type:
195 ---------------------------------------------------
197 For all supported boards there are ready-to-use default
198 configurations available; just type "make <board_name>_config".
200 Example: For a TQM823L module type:
205 For the Cogent platform, you need to specify the cpu type as well;
206 e.g. "make cogent_mpc8xx_config". And also configure the cogent
207 directory according to the instructions in cogent/README.
210 Configuration Options:
211 ----------------------
213 Configuration depends on the combination of board and CPU type; all
214 such information is kept in a configuration file
215 "include/configs/<board_name>.h".
217 Example: For a TQM823L module, all configuration settings are in
218 "include/configs/TQM823L.h".
221 Many of the options are named exactly as the corresponding Linux
222 kernel configuration options. The intention is to make it easier to
223 build a config tool - later.
226 The following options need to be configured:
228 - CPU Type: Define exactly one of
232 CONFIG_MPC823, CONFIG_MPC850, CONFIG_MPC855, CONFIG_MPC860
235 or CONFIG_MPC824X, CONFIG_MPC8260
251 MicroBlaze based CPUs:
252 ----------------------
256 ----------------------
260 - Board Type: Define exactly one of
262 PowerPC based boards:
263 ---------------------
265 CONFIG_ADCIOP CONFIG_FPS860L CONFIG_OXC
266 CONFIG_ADS860 CONFIG_GEN860T CONFIG_PCI405
267 CONFIG_AMX860 CONFIG_GENIETV CONFIG_PCIPPC2
268 CONFIG_AP1000 CONFIG_GTH CONFIG_PCIPPC6
269 CONFIG_AR405 CONFIG_gw8260 CONFIG_pcu_e
270 CONFIG_BAB7xx CONFIG_hermes CONFIG_PIP405
271 CONFIG_BC3450 CONFIG_hymod CONFIG_PM826
272 CONFIG_c2mon CONFIG_IAD210 CONFIG_ppmc8260
273 CONFIG_CANBT CONFIG_ICU862 CONFIG_QS823
274 CONFIG_CCM CONFIG_IP860 CONFIG_QS850
275 CONFIG_CMI CONFIG_IPHASE4539 CONFIG_QS860T
276 CONFIG_cogent_mpc8260 CONFIG_IVML24 CONFIG_RBC823
277 CONFIG_cogent_mpc8xx CONFIG_IVML24_128 CONFIG_RPXClassic
278 CONFIG_CPCI405 CONFIG_IVML24_256 CONFIG_RPXlite
279 CONFIG_CPCI4052 CONFIG_IVMS8 CONFIG_RPXsuper
280 CONFIG_CPCIISER4 CONFIG_IVMS8_128 CONFIG_rsdproto
281 CONFIG_CPU86 CONFIG_IVMS8_256 CONFIG_sacsng
282 CONFIG_CRAYL1 CONFIG_JSE CONFIG_Sandpoint8240
283 CONFIG_CSB272 CONFIG_LANTEC CONFIG_Sandpoint8245
284 CONFIG_CU824 CONFIG_LITE5200B CONFIG_sbc8260
285 CONFIG_DASA_SIM CONFIG_lwmon CONFIG_sbc8560
286 CONFIG_DB64360 CONFIG_MBX CONFIG_SM850
287 CONFIG_DB64460 CONFIG_MBX860T CONFIG_SPD823TS
288 CONFIG_DU405 CONFIG_MHPC CONFIG_STXGP3
289 CONFIG_DUET_ADS CONFIG_MIP405 CONFIG_SXNI855T
290 CONFIG_EBONY CONFIG_MOUSSE CONFIG_TQM823L
291 CONFIG_ELPPC CONFIG_MPC8260ADS CONFIG_TQM8260
292 CONFIG_ELPT860 CONFIG_MPC8540ADS CONFIG_TQM850L
293 CONFIG_ep8260 CONFIG_MPC8540EVAL CONFIG_TQM855L
294 CONFIG_ERIC CONFIG_MPC8560ADS CONFIG_TQM860L
295 CONFIG_ESTEEM192E CONFIG_MUSENKI CONFIG_TTTech
296 CONFIG_ETX094 CONFIG_MVS1 CONFIG_UTX8245
297 CONFIG_EVB64260 CONFIG_NETPHONE CONFIG_V37
298 CONFIG_FADS823 CONFIG_NETTA CONFIG_W7OLMC
299 CONFIG_FADS850SAR CONFIG_NETVIA CONFIG_W7OLMG
300 CONFIG_FADS860T CONFIG_NX823 CONFIG_WALNUT
301 CONFIG_FLAGADM CONFIG_OCRTC CONFIG_ZPC1900
302 CONFIG_FPS850L CONFIG_ORSG CONFIG_ZUMA
307 CONFIG_ARMADILLO, CONFIG_AT91RM9200DK, CONFIG_CERF250,
308 CONFIG_CSB637, CONFIG_DELTA, CONFIG_DNP1110,
309 CONFIG_EP7312, CONFIG_H2_OMAP1610, CONFIG_HHP_CRADLE,
310 CONFIG_IMPA7, CONFIG_INNOVATOROMAP1510, CONFIG_INNOVATOROMAP1610,
311 CONFIG_KB9202, CONFIG_LART, CONFIG_LPD7A400,
312 CONFIG_LUBBOCK, CONFIG_OSK_OMAP5912, CONFIG_OMAP2420H4,
313 CONFIG_SHANNON, CONFIG_P2_OMAP730, CONFIG_SMDK2400,
314 CONFIG_SMDK2410, CONFIG_TRAB, CONFIG_VCMA9
316 MicroBlaze based boards:
317 ------------------------
322 ------------------------
324 CONFIG_PCI5441 CONFIG_PK1C20
325 CONFIG_EP1C20 CONFIG_EP1S10 CONFIG_EP1S40
328 - CPU Module Type: (if CONFIG_COGENT is defined)
329 Define exactly one of
331 --- FIXME --- not tested yet:
332 CONFIG_CMA286_60, CONFIG_CMA286_21, CONFIG_CMA286_60P,
333 CONFIG_CMA287_23, CONFIG_CMA287_50
335 - Motherboard Type: (if CONFIG_COGENT is defined)
336 Define exactly one of
337 CONFIG_CMA101, CONFIG_CMA102
339 - Motherboard I/O Modules: (if CONFIG_COGENT is defined)
340 Define one or more of
343 - Motherboard Options: (if CONFIG_CMA101 or CONFIG_CMA102 are defined)
344 Define one or more of
345 CONFIG_LCD_HEARTBEAT - update a character position on
346 the lcd display every second with
349 - Board flavour: (if CONFIG_MPC8260ADS is defined)
352 CFG_8260ADS - original MPC8260ADS
353 CFG_8266ADS - MPC8266ADS
354 CFG_PQ2FADS - PQ2FADS-ZU or PQ2FADS-VR
355 CFG_8272ADS - MPC8272ADS
357 - MPC824X Family Member (if CONFIG_MPC824X is defined)
358 Define exactly one of
359 CONFIG_MPC8240, CONFIG_MPC8245
361 - 8xx CPU Options: (if using an MPC8xx cpu)
362 CONFIG_8xx_GCLK_FREQ - deprecated: CPU clock if
363 get_gclk_freq() cannot work
364 e.g. if there is no 32KHz
365 reference PIT/RTC clock
366 CONFIG_8xx_OSCLK - PLL input clock (either EXTCLK
369 - 859/866/885 CPU options: (if using a MPC859 or MPC866 or MPC885 CPU):
372 CONFIG_8xx_CPUCLK_DEFAULT
373 See doc/README.MPC866
377 Define this to measure the actual CPU clock instead
378 of relying on the correctness of the configured
379 values. Mostly useful for board bringup to make sure
380 the PLL is locked at the intended frequency. Note
381 that this requires a (stable) reference clock (32 kHz
382 RTC clock or CFG_8XX_XIN)
384 - Intel Monahans options:
385 CFG_MONAHANS_RUN_MODE_OSC_RATIO
387 Defines the Monahans run mode to oscillator
388 ratio. Valid values are 8, 16, 24, 31. The core
389 frequency is this value multiplied by 13 MHz.
391 CFG_MONAHANS_TURBO_RUN_MODE_RATIO
393 Defines the Monahans turbo mode to oscillator
394 ratio. Valid values are 1 (default if undefined) and
395 2. The core frequency as calculated above is multiplied
398 - Linux Kernel Interface:
401 U-Boot stores all clock information in Hz
402 internally. For binary compatibility with older Linux
403 kernels (which expect the clocks passed in the
404 bd_info data to be in MHz) the environment variable
405 "clocks_in_mhz" can be defined so that U-Boot
406 converts clock data to MHZ before passing it to the
408 When CONFIG_CLOCKS_IN_MHZ is defined, a definition of
409 "clocks_in_mhz=1" is automatically included in the
412 CONFIG_MEMSIZE_IN_BYTES [relevant for MIPS only]
414 When transfering memsize parameter to linux, some versions
415 expect it to be in bytes, others in MB.
416 Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes.
420 New kernel versions are expecting firmware settings to be
421 passed using flat open firmware trees.
422 The environment variable "disable_of", when set, disables this
425 CONFIG_OF_FLAT_TREE_MAX_SIZE
427 The maximum size of the constructed OF tree.
429 OF_CPU - The proper name of the cpus node.
430 OF_SOC - The proper name of the soc node.
431 OF_TBCLK - The timebase frequency.
432 OF_STDOUT_PATH - The path to the console device
436 The resulting flat device tree will have a copy of the bd_t.
437 Space should be pre-allocated in the dts for the bd_t.
439 CONFIG_OF_HAS_UBOOT_ENV
441 The resulting flat device tree will have a copy of u-boot's
442 environment variables
444 CONFIG_OF_BOARD_SETUP
446 Board code has addition modification that it wants to make
447 to the flat device tree before handing it off to the kernel
452 Define this if you want support for Amba PrimeCell PL010 UARTs.
456 Define this if you want support for Amba PrimeCell PL011 UARTs.
460 If you have Amba PrimeCell PL011 UARTs, set this variable to
461 the clock speed of the UARTs.
465 If you have Amba PrimeCell PL010 or PL011 UARTs on your board,
466 define this to a list of base addresses for each (supported)
467 port. See e.g. include/configs/versatile.h
471 Depending on board, define exactly one serial port
472 (like CONFIG_8xx_CONS_SMC1, CONFIG_8xx_CONS_SMC2,
473 CONFIG_8xx_CONS_SCC1, ...), or switch off the serial
474 console by defining CONFIG_8xx_CONS_NONE
476 Note: if CONFIG_8xx_CONS_NONE is defined, the serial
477 port routines must be defined elsewhere
478 (i.e. serial_init(), serial_getc(), ...)
481 Enables console device for a color framebuffer. Needs following
482 defines (cf. smiLynxEM, i8042, board/eltec/bab7xx)
483 VIDEO_FB_LITTLE_ENDIAN graphic memory organisation
485 VIDEO_HW_RECTFILL graphic chip supports
488 VIDEO_HW_BITBLT graphic chip supports
489 bit-blit (cf. smiLynxEM)
490 VIDEO_VISIBLE_COLS visible pixel columns
492 VIDEO_VISIBLE_ROWS visible pixel rows
493 VIDEO_PIXEL_SIZE bytes per pixel
494 VIDEO_DATA_FORMAT graphic data format
495 (0-5, cf. cfb_console.c)
496 VIDEO_FB_ADRS framebuffer address
497 VIDEO_KBD_INIT_FCT keyboard int fct
498 (i.e. i8042_kbd_init())
499 VIDEO_TSTC_FCT test char fct
501 VIDEO_GETC_FCT get char fct
503 CONFIG_CONSOLE_CURSOR cursor drawing on/off
504 (requires blink timer
506 CFG_CONSOLE_BLINK_COUNT blink interval (cf. i8042.c)
507 CONFIG_CONSOLE_TIME display time/date info in
509 (requires CFG_CMD_DATE)
510 CONFIG_VIDEO_LOGO display Linux logo in
512 CONFIG_VIDEO_BMP_LOGO use bmp_logo.h instead of
513 linux_logo.h for logo.
514 Requires CONFIG_VIDEO_LOGO
515 CONFIG_CONSOLE_EXTRA_INFO
516 addional board info beside
519 When CONFIG_CFB_CONSOLE is defined, video console is
520 default i/o. Serial console can be forced with
521 environment 'console=serial'.
523 When CONFIG_SILENT_CONSOLE is defined, all console
524 messages (by U-Boot and Linux!) can be silenced with
525 the "silent" environment variable. See
526 doc/README.silent for more information.
529 CONFIG_BAUDRATE - in bps
530 Select one of the baudrates listed in
531 CFG_BAUDRATE_TABLE, see below.
532 CFG_BRGCLK_PRESCALE, baudrate prescale
534 - Interrupt driven serial port input:
535 CONFIG_SERIAL_SOFTWARE_FIFO
538 Use an interrupt handler for receiving data on the
539 serial port. It also enables using hardware handshake
540 (RTS/CTS) and UART's built-in FIFO. Set the number of
541 bytes the interrupt driven input buffer should have.
543 Leave undefined to disable this feature, including
544 disable the buffer and hardware handshake.
546 - Console UART Number:
550 If defined internal UART1 (and not UART0) is used
551 as default U-Boot console.
553 - Boot Delay: CONFIG_BOOTDELAY - in seconds
554 Delay before automatically booting the default image;
555 set to -1 to disable autoboot.
557 See doc/README.autoboot for these options that
558 work with CONFIG_BOOTDELAY. None are required.
559 CONFIG_BOOT_RETRY_TIME
560 CONFIG_BOOT_RETRY_MIN
561 CONFIG_AUTOBOOT_KEYED
562 CONFIG_AUTOBOOT_PROMPT
563 CONFIG_AUTOBOOT_DELAY_STR
564 CONFIG_AUTOBOOT_STOP_STR
565 CONFIG_AUTOBOOT_DELAY_STR2
566 CONFIG_AUTOBOOT_STOP_STR2
567 CONFIG_ZERO_BOOTDELAY_CHECK
568 CONFIG_RESET_TO_RETRY
572 Only needed when CONFIG_BOOTDELAY is enabled;
573 define a command string that is automatically executed
574 when no character is read on the console interface
575 within "Boot Delay" after reset.
578 This can be used to pass arguments to the bootm
579 command. The value of CONFIG_BOOTARGS goes into the
580 environment value "bootargs".
582 CONFIG_RAMBOOT and CONFIG_NFSBOOT
583 The value of these goes into the environment as
584 "ramboot" and "nfsboot" respectively, and can be used
585 as a convenience, when switching between booting from
591 When this option is #defined, the existence of the
592 environment variable "preboot" will be checked
593 immediately before starting the CONFIG_BOOTDELAY
594 countdown and/or running the auto-boot command resp.
595 entering interactive mode.
597 This feature is especially useful when "preboot" is
598 automatically generated or modified. For an example
599 see the LWMON board specific code: here "preboot" is
600 modified when the user holds down a certain
601 combination of keys on the (special) keyboard when
604 - Serial Download Echo Mode:
606 If defined to 1, all characters received during a
607 serial download (using the "loads" command) are
608 echoed back. This might be needed by some terminal
609 emulations (like "cu"), but may as well just take
610 time on others. This setting #define's the initial
611 value of the "loads_echo" environment variable.
613 - Kgdb Serial Baudrate: (if CFG_CMD_KGDB is defined)
615 Select one of the baudrates listed in
616 CFG_BAUDRATE_TABLE, see below.
620 Most monitor functions can be selected (or
621 de-selected) by adjusting the definition of
622 CONFIG_COMMANDS; to select individual functions,
623 #define CONFIG_COMMANDS by "OR"ing any of the
626 #define enables commands:
627 -------------------------
628 CFG_CMD_ASKENV * ask for env variable
629 CFG_CMD_AUTOSCRIPT Autoscript Support
631 CFG_CMD_BEDBUG * Include BedBug Debugger
632 CFG_CMD_BMP * BMP support
633 CFG_CMD_BSP * Board specific commands
635 CFG_CMD_CACHE * icache, dcache
636 CFG_CMD_CONSOLE coninfo
637 CFG_CMD_DATE * support for RTC, date/time...
638 CFG_CMD_DHCP * DHCP support
639 CFG_CMD_DIAG * Diagnostics
640 CFG_CMD_DOC * Disk-On-Chip Support
641 CFG_CMD_DTT * Digital Therm and Thermostat
642 CFG_CMD_ECHO echo arguments
643 CFG_CMD_EEPROM * EEPROM read/write support
644 CFG_CMD_ELF * bootelf, bootvx
646 CFG_CMD_FDC * Floppy Disk Support
647 CFG_CMD_FAT * FAT partition support
648 CFG_CMD_FDOS * Dos diskette Support
649 CFG_CMD_FLASH flinfo, erase, protect
650 CFG_CMD_FPGA FPGA device initialization support
651 CFG_CMD_HWFLOW * RTS/CTS hw flow control
652 CFG_CMD_I2C * I2C serial bus support
653 CFG_CMD_IDE * IDE harddisk support
655 CFG_CMD_IMLS List all found images
656 CFG_CMD_IMMAP * IMMR dump support
657 CFG_CMD_IRQ * irqinfo
658 CFG_CMD_ITEST Integer/string test of 2 values
659 CFG_CMD_JFFS2 * JFFS2 Support
663 CFG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base,
665 CFG_CMD_MISC Misc functions like sleep etc
666 CFG_CMD_MMC * MMC memory mapped support
667 CFG_CMD_MII * MII utility commands
668 CFG_CMD_NAND * NAND support
669 CFG_CMD_NET bootp, tftpboot, rarpboot
670 CFG_CMD_PCI * pciinfo
671 CFG_CMD_PCMCIA * PCMCIA support
672 CFG_CMD_PING * send ICMP ECHO_REQUEST to network host
673 CFG_CMD_PORTIO * Port I/O
674 CFG_CMD_REGINFO * Register dump
675 CFG_CMD_RUN run command in env variable
676 CFG_CMD_SAVES * save S record dump
677 CFG_CMD_SCSI * SCSI Support
678 CFG_CMD_SDRAM * print SDRAM configuration information
679 (requires CFG_CMD_I2C)
680 CFG_CMD_SETGETDCR Support for DCR Register access (4xx only)
681 CFG_CMD_SPI * SPI serial bus support
682 CFG_CMD_USB * USB support
683 CFG_CMD_VFD * VFD support (TRAB)
684 CFG_CMD_BSP * Board SPecific functions
685 CFG_CMD_CDP * Cisco Discover Protocol support
686 -----------------------------------------------
689 CONFIG_CMD_DFL Default configuration; at the moment
690 this is includes all commands, except
691 the ones marked with "*" in the list
694 If you don't define CONFIG_COMMANDS it defaults to
695 CONFIG_CMD_DFL in include/cmd_confdefs.h. A board can
696 override the default settings in the respective
699 EXAMPLE: If you want all functions except of network
700 support you can write:
702 #define CONFIG_COMMANDS (CFG_CMD_ALL & ~CFG_CMD_NET)
705 Note: Don't enable the "icache" and "dcache" commands
706 (configuration option CFG_CMD_CACHE) unless you know
707 what you (and your U-Boot users) are doing. Data
708 cache cannot be enabled on systems like the 8xx or
709 8260 (where accesses to the IMMR region must be
710 uncached), and it cannot be disabled on all other
711 systems where we (mis-) use the data cache to hold an
712 initial stack and some data.
715 XXX - this list needs to get updated!
719 If this variable is defined, it enables watchdog
720 support. There must be support in the platform specific
721 code for a watchdog. For the 8xx and 8260 CPUs, the
722 SIU Watchdog feature is enabled in the SYPCR
726 CONFIG_VERSION_VARIABLE
727 If this variable is defined, an environment variable
728 named "ver" is created by U-Boot showing the U-Boot
729 version as printed by the "version" command.
730 This variable is readonly.
734 When CFG_CMD_DATE is selected, the type of the RTC
735 has to be selected, too. Define exactly one of the
738 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx
739 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC
740 CONFIG_RTC_MC146818 - use MC146818 RTC
741 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC
742 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC
743 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC
744 CONFIG_RTC_DS164x - use Dallas DS164x RTC
745 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC
747 Note that if the RTC uses I2C, then the I2C interface
748 must also be configured. See I2C Support, below.
752 When CONFIG_TIMESTAMP is selected, the timestamp
753 (date and time) of an image is printed by image
754 commands like bootm or iminfo. This option is
755 automatically enabled when you select CFG_CMD_DATE .
758 CONFIG_MAC_PARTITION and/or CONFIG_DOS_PARTITION
759 and/or CONFIG_ISO_PARTITION
761 If IDE or SCSI support is enabled (CFG_CMD_IDE or
762 CFG_CMD_SCSI) you must configure support for at least
763 one partition type as well.
766 CONFIG_IDE_RESET_ROUTINE - this is defined in several
767 board configurations files but used nowhere!
769 CONFIG_IDE_RESET - is this is defined, IDE Reset will
770 be performed by calling the function
771 ide_set_reset(int reset)
772 which has to be defined in a board specific file
777 Set this to enable ATAPI support.
782 Set this to enable support for disks larger than 137GB
783 Also look at CFG_64BIT_LBA ,CFG_64BIT_VSPRINTF and CFG_64BIT_STRTOUL
784 Whithout these , LBA48 support uses 32bit variables and will 'only'
785 support disks up to 2.1TB.
788 When enabled, makes the IDE subsystem use 64bit sector addresses.
792 At the moment only there is only support for the
793 SYM53C8XX SCSI controller; define
794 CONFIG_SCSI_SYM53C8XX to enable it.
796 CFG_SCSI_MAX_LUN [8], CFG_SCSI_MAX_SCSI_ID [7] and
797 CFG_SCSI_MAX_DEVICE [CFG_SCSI_MAX_SCSI_ID *
798 CFG_SCSI_MAX_LUN] can be adjusted to define the
799 maximum numbers of LUNs, SCSI ID's and target
801 CFG_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz)
803 - NETWORK Support (PCI):
805 Support for Intel 8254x gigabit chips.
808 Support for Intel 82557/82559/82559ER chips.
809 Optional CONFIG_EEPRO100_SROM_WRITE enables eeprom
810 write routine for first time initialisation.
813 Support for Digital 2114x chips.
814 Optional CONFIG_TULIP_SELECT_MEDIA for board specific
815 modem chip initialisation (KS8761/QS6611).
818 Support for National dp83815 chips.
821 Support for National dp8382[01] gigabit chips.
823 - NETWORK Support (other):
825 CONFIG_DRIVER_LAN91C96
826 Support for SMSC's LAN91C96 chips.
829 Define this to hold the physical address
830 of the LAN91C96's I/O space
832 CONFIG_LAN91C96_USE_32_BIT
833 Define this to enable 32 bit addressing
835 CONFIG_DRIVER_SMC91111
836 Support for SMSC's LAN91C111 chip
839 Define this to hold the physical address
840 of the device (I/O space)
842 CONFIG_SMC_USE_32_BIT
843 Define this if data bus is 32 bits
845 CONFIG_SMC_USE_IOFUNCS
846 Define this to use i/o functions instead of macros
847 (some hardware wont work with macros)
850 At the moment only the UHCI host controller is
851 supported (PIP405, MIP405, MPC5200); define
852 CONFIG_USB_UHCI to enable it.
853 define CONFIG_USB_KEYBOARD to enable the USB Keyboard
854 and define CONFIG_USB_STORAGE to enable the USB
857 Supported are USB Keyboards and USB Floppy drives
859 MPC5200 USB requires additional defines:
861 for 528 MHz Clock: 0x0001bbbb
863 for differential drivers: 0x00001000
864 for single ended drivers: 0x00005000
868 The MMC controller on the Intel PXA is supported. To
869 enable this define CONFIG_MMC. The MMC can be
870 accessed from the boot prompt by mapping the device
871 to physical memory similar to flash. Command line is
872 enabled with CFG_CMD_MMC. The MMC driver also works with
873 the FAT fs. This is enabled with CFG_CMD_FAT.
875 - Journaling Flash filesystem support:
876 CONFIG_JFFS2_NAND, CONFIG_JFFS2_NAND_OFF, CONFIG_JFFS2_NAND_SIZE,
877 CONFIG_JFFS2_NAND_DEV
878 Define these for a default partition on a NAND device
880 CFG_JFFS2_FIRST_SECTOR,
881 CFG_JFFS2_FIRST_BANK, CFG_JFFS2_NUM_BANKS
882 Define these for a default partition on a NOR device
885 Define this to create an own partition. You have to provide a
886 function struct part_info* jffs2_part_info(int part_num)
888 If you define only one JFFS2 partition you may also want to
889 #define CFG_JFFS_SINGLE_PART 1
890 to disable the command chpart. This is the default when you
891 have not defined a custom partition
896 Define this to enable standard (PC-Style) keyboard
900 Standard PC keyboard driver with US (is default) and
901 GERMAN key layout (switch via environment 'keymap=de') support.
902 Export function i8042_kbd_init, i8042_tstc and i8042_getc
903 for cfb_console. Supports cursor blinking.
908 Define this to enable video support (for output to
913 Enable Chips & Technologies 69000 Video chip
915 CONFIG_VIDEO_SMI_LYNXEM
916 Enable Silicon Motion SMI 712/710/810 Video chip. The
917 video output is selected via environment 'videoout'
918 (1 = LCD and 2 = CRT). If videoout is undefined, CRT is
921 For the CT69000 and SMI_LYNXEM drivers, videomode is
922 selected via environment 'videomode'. Two diferent ways
924 - "videomode=num" 'num' is a standard LiLo mode numbers.
925 Following standard modes are supported (* is default):
927 Colors 640x480 800x600 1024x768 1152x864 1280x1024
928 -------------+---------------------------------------------
929 8 bits | 0x301* 0x303 0x305 0x161 0x307
930 15 bits | 0x310 0x313 0x316 0x162 0x319
931 16 bits | 0x311 0x314 0x317 0x163 0x31A
932 24 bits | 0x312 0x315 0x318 ? 0x31B
933 -------------+---------------------------------------------
934 (i.e. setenv videomode 317; saveenv; reset;)
936 - "videomode=bootargs" all the video parameters are parsed
937 from the bootargs. (See drivers/videomodes.c)
940 CONFIG_VIDEO_SED13806
941 Enable Epson SED13806 driver. This driver supports 8bpp
942 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP
943 or CONFIG_VIDEO_SED13806_16BPP
948 Define this to enable a custom keyboard support.
949 This simply calls drv_keyboard_init() which must be
950 defined in your board-specific files.
951 The only board using this so far is RBC823.
953 - LCD Support: CONFIG_LCD
955 Define this to enable LCD support (for output to LCD
956 display); also select one of the supported displays
957 by defining one of these:
959 CONFIG_NEC_NL6448AC33:
961 NEC NL6448AC33-18. Active, color, single scan.
963 CONFIG_NEC_NL6448BC20
965 NEC NL6448BC20-08. 6.5", 640x480.
966 Active, color, single scan.
968 CONFIG_NEC_NL6448BC33_54
970 NEC NL6448BC33-54. 10.4", 640x480.
971 Active, color, single scan.
975 Sharp 320x240. Active, color, single scan.
976 It isn't 16x9, and I am not sure what it is.
978 CONFIG_SHARP_LQ64D341
980 Sharp LQ64D341 display, 640x480.
981 Active, color, single scan.
985 HLD1045 display, 640x480.
986 Active, color, single scan.
990 Optrex CBL50840-2 NF-FW 99 22 M5
992 Hitachi LMG6912RPFC-00T
996 320x240. Black & white.
998 Normally display is black on white background; define
999 CFG_WHITE_ON_BLACK to get it inverted.
1001 - Splash Screen Support: CONFIG_SPLASH_SCREEN
1003 If this option is set, the environment is checked for
1004 a variable "splashimage". If found, the usual display
1005 of logo, copyright and system information on the LCD
1006 is suppressed and the BMP image at the address
1007 specified in "splashimage" is loaded instead. The
1008 console is redirected to the "nulldev", too. This
1009 allows for a "silent" boot where a splash screen is
1010 loaded very quickly after power-on.
1012 - Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP
1014 If this option is set, additionally to standard BMP
1015 images, gzipped BMP images can be displayed via the
1016 splashscreen support or the bmp command.
1018 - Compression support:
1021 If this option is set, support for bzip2 compressed
1022 images is included. If not, only uncompressed and gzip
1023 compressed images are supported.
1025 NOTE: the bzip2 algorithm requires a lot of RAM, so
1026 the malloc area (as defined by CFG_MALLOC_LEN) should
1032 The address of PHY on MII bus.
1034 CONFIG_PHY_CLOCK_FREQ (ppc4xx)
1036 The clock frequency of the MII bus
1040 If this option is set, support for speed/duplex
1041 detection of Gigabit PHY is included.
1043 CONFIG_PHY_RESET_DELAY
1045 Some PHY like Intel LXT971A need extra delay after
1046 reset before any MII register access is possible.
1047 For such PHY, set this option to the usec delay
1048 required. (minimum 300usec for LXT971A)
1050 CONFIG_PHY_CMD_DELAY (ppc4xx)
1052 Some PHY like Intel LXT971A need extra delay after
1053 command issued before MII status register can be read
1060 Define a default value for ethernet address to use
1061 for the respective ethernet interface, in case this
1062 is not determined automatically.
1067 Define a default value for the IP address to use for
1068 the default ethernet interface, in case this is not
1069 determined through e.g. bootp.
1071 - Server IP address:
1074 Defines a default value for theIP address of a TFTP
1075 server to contact when using the "tftboot" command.
1077 - BOOTP Recovery Mode:
1078 CONFIG_BOOTP_RANDOM_DELAY
1080 If you have many targets in a network that try to
1081 boot using BOOTP, you may want to avoid that all
1082 systems send out BOOTP requests at precisely the same
1083 moment (which would happen for instance at recovery
1084 from a power failure, when all systems will try to
1085 boot, thus flooding the BOOTP server. Defining
1086 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
1087 inserted before sending out BOOTP requests. The
1088 following delays are insterted then:
1090 1st BOOTP request: delay 0 ... 1 sec
1091 2nd BOOTP request: delay 0 ... 2 sec
1092 3rd BOOTP request: delay 0 ... 4 sec
1094 BOOTP requests: delay 0 ... 8 sec
1096 - DHCP Advanced Options:
1099 You can fine tune the DHCP functionality by adding
1100 these flags to the CONFIG_BOOTP_MASK define:
1102 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS
1103 serverip from a DHCP server, it is possible that more
1104 than one DNS serverip is offered to the client.
1105 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS
1106 serverip will be stored in the additional environment
1107 variable "dnsip2". The first DNS serverip is always
1108 stored in the variable "dnsip", when CONFIG_BOOTP_DNS
1109 is added to the CONFIG_BOOTP_MASK.
1111 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable
1112 to do a dynamic update of a DNS server. To do this, they
1113 need the hostname of the DHCP requester.
1114 If CONFIG_BOOP_SEND_HOSTNAME is added to the
1115 CONFIG_BOOTP_MASK, the content of the "hostname"
1116 environment variable is passed as option 12 to
1120 CONFIG_CDP_DEVICE_ID
1122 The device id used in CDP trigger frames.
1124 CONFIG_CDP_DEVICE_ID_PREFIX
1126 A two character string which is prefixed to the MAC address
1131 A printf format string which contains the ascii name of
1132 the port. Normally is set to "eth%d" which sets
1133 eth0 for the first ethernet, eth1 for the second etc.
1135 CONFIG_CDP_CAPABILITIES
1137 A 32bit integer which indicates the device capabilities;
1138 0x00000010 for a normal host which does not forwards.
1142 An ascii string containing the version of the software.
1146 An ascii string containing the name of the platform.
1150 A 32bit integer sent on the trigger.
1152 CONFIG_CDP_POWER_CONSUMPTION
1154 A 16bit integer containing the power consumption of the
1155 device in .1 of milliwatts.
1157 CONFIG_CDP_APPLIANCE_VLAN_TYPE
1159 A byte containing the id of the VLAN.
1161 - Status LED: CONFIG_STATUS_LED
1163 Several configurations allow to display the current
1164 status using a LED. For instance, the LED will blink
1165 fast while running U-Boot code, stop blinking as
1166 soon as a reply to a BOOTP request was received, and
1167 start blinking slow once the Linux kernel is running
1168 (supported by a status LED driver in the Linux
1169 kernel). Defining CONFIG_STATUS_LED enables this
1172 - CAN Support: CONFIG_CAN_DRIVER
1174 Defining CONFIG_CAN_DRIVER enables CAN driver support
1175 on those systems that support this (optional)
1176 feature, like the TQM8xxL modules.
1178 - I2C Support: CONFIG_HARD_I2C | CONFIG_SOFT_I2C
1180 These enable I2C serial bus commands. Defining either of
1181 (but not both of) CONFIG_HARD_I2C or CONFIG_SOFT_I2C will
1182 include the appropriate I2C driver for the selected cpu.
1184 This will allow you to use i2c commands at the u-boot
1185 command line (as long as you set CFG_CMD_I2C in
1186 CONFIG_COMMANDS) and communicate with i2c based realtime
1187 clock chips. See common/cmd_i2c.c for a description of the
1188 command line interface.
1190 CONFIG_HARD_I2C selects the CPM hardware driver for I2C.
1192 CONFIG_SOFT_I2C configures u-boot to use a software (aka
1193 bit-banging) driver instead of CPM or similar hardware
1196 There are several other quantities that must also be
1197 defined when you define CONFIG_HARD_I2C or CONFIG_SOFT_I2C.
1199 In both cases you will need to define CFG_I2C_SPEED
1200 to be the frequency (in Hz) at which you wish your i2c bus
1201 to run and CFG_I2C_SLAVE to be the address of this node (ie
1202 the cpu's i2c node address).
1204 Now, the u-boot i2c code for the mpc8xx (cpu/mpc8xx/i2c.c)
1205 sets the cpu up as a master node and so its address should
1206 therefore be cleared to 0 (See, eg, MPC823e User's Manual
1207 p.16-473). So, set CFG_I2C_SLAVE to 0.
1209 That's all that's required for CONFIG_HARD_I2C.
1211 If you use the software i2c interface (CONFIG_SOFT_I2C)
1212 then the following macros need to be defined (examples are
1213 from include/configs/lwmon.h):
1217 (Optional). Any commands necessary to enable the I2C
1218 controller or configure ports.
1220 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
1224 (Only for MPC8260 CPU). The I/O port to use (the code
1225 assumes both bits are on the same port). Valid values
1226 are 0..3 for ports A..D.
1230 The code necessary to make the I2C data line active
1231 (driven). If the data line is open collector, this
1234 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
1238 The code necessary to make the I2C data line tri-stated
1239 (inactive). If the data line is open collector, this
1242 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
1246 Code that returns TRUE if the I2C data line is high,
1249 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
1253 If <bit> is TRUE, sets the I2C data line high. If it
1254 is FALSE, it clears it (low).
1256 eg: #define I2C_SDA(bit) \
1257 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
1258 else immr->im_cpm.cp_pbdat &= ~PB_SDA
1262 If <bit> is TRUE, sets the I2C clock line high. If it
1263 is FALSE, it clears it (low).
1265 eg: #define I2C_SCL(bit) \
1266 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
1267 else immr->im_cpm.cp_pbdat &= ~PB_SCL
1271 This delay is invoked four times per clock cycle so this
1272 controls the rate of data transfer. The data rate thus
1273 is 1 / (I2C_DELAY * 4). Often defined to be something
1276 #define I2C_DELAY udelay(2)
1280 When a board is reset during an i2c bus transfer
1281 chips might think that the current transfer is still
1282 in progress. On some boards it is possible to access
1283 the i2c SCLK line directly, either by using the
1284 processor pin as a GPIO or by having a second pin
1285 connected to the bus. If this option is defined a
1286 custom i2c_init_board() routine in boards/xxx/board.c
1287 is run early in the boot sequence.
1289 CONFIG_I2CFAST (PPC405GP|PPC405EP only)
1291 This option enables configuration of bi_iic_fast[] flags
1292 in u-boot bd_info structure based on u-boot environment
1293 variable "i2cfast". (see also i2cfast)
1295 - SPI Support: CONFIG_SPI
1297 Enables SPI driver (so far only tested with
1298 SPI EEPROM, also an instance works with Crystal A/D and
1299 D/As on the SACSng board)
1303 Enables extended (16-bit) SPI EEPROM addressing.
1304 (symmetrical to CONFIG_I2C_X)
1308 Enables a software (bit-bang) SPI driver rather than
1309 using hardware support. This is a general purpose
1310 driver that only requires three general I/O port pins
1311 (two outputs, one input) to function. If this is
1312 defined, the board configuration must define several
1313 SPI configuration items (port pins to use, etc). For
1314 an example, see include/configs/sacsng.h.
1316 - FPGA Support: CONFIG_FPGA_COUNT
1318 Specify the number of FPGA devices to support.
1322 Used to specify the types of FPGA devices. For example,
1323 #define CONFIG_FPGA CFG_XILINX_VIRTEX2
1325 CFG_FPGA_PROG_FEEDBACK
1327 Enable printing of hash marks during FPGA configuration.
1331 Enable checks on FPGA configuration interface busy
1332 status by the configuration function. This option
1333 will require a board or device specific function to
1338 If defined, a function that provides delays in the FPGA
1339 configuration driver.
1341 CFG_FPGA_CHECK_CTRLC
1342 Allow Control-C to interrupt FPGA configuration
1344 CFG_FPGA_CHECK_ERROR
1346 Check for configuration errors during FPGA bitfile
1347 loading. For example, abort during Virtex II
1348 configuration if the INIT_B line goes low (which
1349 indicated a CRC error).
1353 Maximum time to wait for the INIT_B line to deassert
1354 after PROB_B has been deasserted during a Virtex II
1355 FPGA configuration sequence. The default time is 500
1360 Maximum time to wait for BUSY to deassert during
1361 Virtex II FPGA configuration. The default is 5 mS.
1363 CFG_FPGA_WAIT_CONFIG
1365 Time to wait after FPGA configuration. The default is
1368 - Configuration Management:
1371 If defined, this string will be added to the U-Boot
1372 version information (U_BOOT_VERSION)
1374 - Vendor Parameter Protection:
1376 U-Boot considers the values of the environment
1377 variables "serial#" (Board Serial Number) and
1378 "ethaddr" (Ethernet Address) to be parameters that
1379 are set once by the board vendor / manufacturer, and
1380 protects these variables from casual modification by
1381 the user. Once set, these variables are read-only,
1382 and write or delete attempts are rejected. You can
1383 change this behviour:
1385 If CONFIG_ENV_OVERWRITE is #defined in your config
1386 file, the write protection for vendor parameters is
1387 completely disabled. Anybody can change or delete
1390 Alternatively, if you #define _both_ CONFIG_ETHADDR
1391 _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
1392 ethernet address is installed in the environment,
1393 which can be changed exactly ONCE by the user. [The
1394 serial# is unaffected by this, i. e. it remains
1400 Define this variable to enable the reservation of
1401 "protected RAM", i. e. RAM which is not overwritten
1402 by U-Boot. Define CONFIG_PRAM to hold the number of
1403 kB you want to reserve for pRAM. You can overwrite
1404 this default value by defining an environment
1405 variable "pram" to the number of kB you want to
1406 reserve. Note that the board info structure will
1407 still show the full amount of RAM. If pRAM is
1408 reserved, a new environment variable "mem" will
1409 automatically be defined to hold the amount of
1410 remaining RAM in a form that can be passed as boot
1411 argument to Linux, for instance like that:
1413 setenv bootargs ... mem=\${mem}
1416 This way you can tell Linux not to use this memory,
1417 either, which results in a memory region that will
1418 not be affected by reboots.
1420 *WARNING* If your board configuration uses automatic
1421 detection of the RAM size, you must make sure that
1422 this memory test is non-destructive. So far, the
1423 following board configurations are known to be
1426 ETX094, IVMS8, IVML24, SPD8xx, TQM8xxL,
1427 HERMES, IP860, RPXlite, LWMON, LANTEC,
1428 PCU_E, FLAGADM, TQM8260
1433 Define this variable to stop the system in case of a
1434 fatal error, so that you have to reset it manually.
1435 This is probably NOT a good idea for an embedded
1436 system where you want to system to reboot
1437 automatically as fast as possible, but it may be
1438 useful during development since you can try to debug
1439 the conditions that lead to the situation.
1441 CONFIG_NET_RETRY_COUNT
1443 This variable defines the number of retries for
1444 network operations like ARP, RARP, TFTP, or BOOTP
1445 before giving up the operation. If not defined, a
1446 default value of 5 is used.
1448 - Command Interpreter:
1451 Enable auto completion of commands using TAB.
1455 Define this variable to enable the "hush" shell (from
1456 Busybox) as command line interpreter, thus enabling
1457 powerful command line syntax like
1458 if...then...else...fi conditionals or `&&' and '||'
1459 constructs ("shell scripts").
1461 If undefined, you get the old, much simpler behaviour
1462 with a somewhat smaller memory footprint.
1467 This defines the secondary prompt string, which is
1468 printed when the command interpreter needs more input
1469 to complete a command. Usually "> ".
1473 In the current implementation, the local variables
1474 space and global environment variables space are
1475 separated. Local variables are those you define by
1476 simply typing `name=value'. To access a local
1477 variable later on, you have write `$name' or
1478 `${name}'; to execute the contents of a variable
1479 directly type `$name' at the command prompt.
1481 Global environment variables are those you use
1482 setenv/printenv to work with. To run a command stored
1483 in such a variable, you need to use the run command,
1484 and you must not use the '$' sign to access them.
1486 To store commands and special characters in a
1487 variable, please use double quotation marks
1488 surrounding the whole text of the variable, instead
1489 of the backslashes before semicolons and special
1492 - Default Environment:
1493 CONFIG_EXTRA_ENV_SETTINGS
1495 Define this to contain any number of null terminated
1496 strings (variable = value pairs) that will be part of
1497 the default environment compiled into the boot image.
1499 For example, place something like this in your
1500 board's config file:
1502 #define CONFIG_EXTRA_ENV_SETTINGS \
1506 Warning: This method is based on knowledge about the
1507 internal format how the environment is stored by the
1508 U-Boot code. This is NOT an official, exported
1509 interface! Although it is unlikely that this format
1510 will change soon, there is no guarantee either.
1511 You better know what you are doing here.
1513 Note: overly (ab)use of the default environment is
1514 discouraged. Make sure to check other ways to preset
1515 the environment like the autoscript function or the
1518 - DataFlash Support:
1519 CONFIG_HAS_DATAFLASH
1521 Defining this option enables DataFlash features and
1522 allows to read/write in Dataflash via the standard
1525 - SystemACE Support:
1528 Adding this option adds support for Xilinx SystemACE
1529 chips attached via some sort of local bus. The address
1530 of the chip must alsh be defined in the
1531 CFG_SYSTEMACE_BASE macro. For example:
1533 #define CONFIG_SYSTEMACE
1534 #define CFG_SYSTEMACE_BASE 0xf0000000
1536 When SystemACE support is added, the "ace" device type
1537 becomes available to the fat commands, i.e. fatls.
1539 - TFTP Fixed UDP Port:
1542 If this is defined, the environment variable tftpsrcp
1543 is used to supply the TFTP UDP source port value.
1544 If tftpsrcp isn't defined, the normal pseudo-random port
1545 number generator is used.
1547 Also, the environment variable tftpdstp is used to supply
1548 the TFTP UDP destination port value. If tftpdstp isn't
1549 defined, the normal port 69 is used.
1551 The purpose for tftpsrcp is to allow a TFTP server to
1552 blindly start the TFTP transfer using the pre-configured
1553 target IP address and UDP port. This has the effect of
1554 "punching through" the (Windows XP) firewall, allowing
1555 the remainder of the TFTP transfer to proceed normally.
1556 A better solution is to properly configure the firewall,
1557 but sometimes that is not allowed.
1559 - Show boot progress:
1560 CONFIG_SHOW_BOOT_PROGRESS
1562 Defining this option allows to add some board-
1563 specific code (calling a user-provided function
1564 "show_boot_progress(int)") that enables you to show
1565 the system's boot progress on some display (for
1566 example, some LED's) on your board. At the moment,
1567 the following checkpoints are implemented:
1570 1 common/cmd_bootm.c before attempting to boot an image
1571 -1 common/cmd_bootm.c Image header has bad magic number
1572 2 common/cmd_bootm.c Image header has correct magic number
1573 -2 common/cmd_bootm.c Image header has bad checksum
1574 3 common/cmd_bootm.c Image header has correct checksum
1575 -3 common/cmd_bootm.c Image data has bad checksum
1576 4 common/cmd_bootm.c Image data has correct checksum
1577 -4 common/cmd_bootm.c Image is for unsupported architecture
1578 5 common/cmd_bootm.c Architecture check OK
1579 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi, standalone)
1580 6 common/cmd_bootm.c Image Type check OK
1581 -6 common/cmd_bootm.c gunzip uncompression error
1582 -7 common/cmd_bootm.c Unimplemented compression type
1583 7 common/cmd_bootm.c Uncompression OK
1584 -8 common/cmd_bootm.c Wrong Image Type (not kernel, multi, standalone)
1585 8 common/cmd_bootm.c Image Type check OK
1586 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX)
1587 9 common/cmd_bootm.c Start initial ramdisk verification
1588 -10 common/cmd_bootm.c Ramdisk header has bad magic number
1589 -11 common/cmd_bootm.c Ramdisk header has bad checksum
1590 10 common/cmd_bootm.c Ramdisk header is OK
1591 -12 common/cmd_bootm.c Ramdisk data has bad checksum
1592 11 common/cmd_bootm.c Ramdisk data has correct checksum
1593 12 common/cmd_bootm.c Ramdisk verification complete, start loading
1594 -13 common/cmd_bootm.c Wrong Image Type (not PPC Linux Ramdisk)
1595 13 common/cmd_bootm.c Start multifile image verification
1596 14 common/cmd_bootm.c No initial ramdisk, no multifile, continue.
1597 15 common/cmd_bootm.c All preparation done, transferring control to OS
1599 -30 lib_ppc/board.c Fatal error, hang the system
1600 -31 post/post.c POST test failed, detected by post_output_backlog()
1601 -32 post/post.c POST test failed, detected by post_run_single()
1603 -1 common/cmd_doc.c Bad usage of "doc" command
1604 -1 common/cmd_doc.c No boot device
1605 -1 common/cmd_doc.c Unknown Chip ID on boot device
1606 -1 common/cmd_doc.c Read Error on boot device
1607 -1 common/cmd_doc.c Image header has bad magic number
1609 -1 common/cmd_ide.c Bad usage of "ide" command
1610 -1 common/cmd_ide.c No boot device
1611 -1 common/cmd_ide.c Unknown boot device
1612 -1 common/cmd_ide.c Unknown partition table
1613 -1 common/cmd_ide.c Invalid partition type
1614 -1 common/cmd_ide.c Read Error on boot device
1615 -1 common/cmd_ide.c Image header has bad magic number
1617 -1 common/cmd_nand.c Bad usage of "nand" command
1618 -1 common/cmd_nand.c No boot device
1619 -1 common/cmd_nand.c Unknown Chip ID on boot device
1620 -1 common/cmd_nand.c Read Error on boot device
1621 -1 common/cmd_nand.c Image header has bad magic number
1623 -1 common/env_common.c Environment has a bad CRC, using default
1629 [so far only for SMDK2400 and TRAB boards]
1631 - Modem support endable:
1632 CONFIG_MODEM_SUPPORT
1634 - RTS/CTS Flow control enable:
1637 - Modem debug support:
1638 CONFIG_MODEM_SUPPORT_DEBUG
1640 Enables debugging stuff (char screen[1024], dbg())
1641 for modem support. Useful only with BDI2000.
1643 - Interrupt support (PPC):
1645 There are common interrupt_init() and timer_interrupt()
1646 for all PPC archs. interrupt_init() calls interrupt_init_cpu()
1647 for cpu specific initialization. interrupt_init_cpu()
1648 should set decrementer_count to appropriate value. If
1649 cpu resets decrementer automatically after interrupt
1650 (ppc4xx) it should set decrementer_count to zero.
1651 timer_interrupt() calls timer_interrupt_cpu() for cpu
1652 specific handling. If board has watchdog / status_led
1653 / other_activity_monitor it works automatically from
1654 general timer_interrupt().
1658 In the target system modem support is enabled when a
1659 specific key (key combination) is pressed during
1660 power-on. Otherwise U-Boot will boot normally
1661 (autoboot). The key_pressed() fuction is called from
1662 board_init(). Currently key_pressed() is a dummy
1663 function, returning 1 and thus enabling modem
1666 If there are no modem init strings in the
1667 environment, U-Boot proceed to autoboot; the
1668 previous output (banner, info printfs) will be
1671 See also: doc/README.Modem
1674 Configuration Settings:
1675 -----------------------
1677 - CFG_LONGHELP: Defined when you want long help messages included;
1678 undefine this when you're short of memory.
1680 - CFG_PROMPT: This is what U-Boot prints on the console to
1681 prompt for user input.
1683 - CFG_CBSIZE: Buffer size for input from the Console
1685 - CFG_PBSIZE: Buffer size for Console output
1687 - CFG_MAXARGS: max. Number of arguments accepted for monitor commands
1689 - CFG_BARGSIZE: Buffer size for Boot Arguments which are passed to
1690 the application (usually a Linux kernel) when it is
1693 - CFG_BAUDRATE_TABLE:
1694 List of legal baudrate settings for this board.
1696 - CFG_CONSOLE_INFO_QUIET
1697 Suppress display of console information at boot.
1699 - CFG_CONSOLE_IS_IN_ENV
1700 If the board specific function
1701 extern int overwrite_console (void);
1702 returns 1, the stdin, stderr and stdout are switched to the
1703 serial port, else the settings in the environment are used.
1705 - CFG_CONSOLE_OVERWRITE_ROUTINE
1706 Enable the call to overwrite_console().
1708 - CFG_CONSOLE_ENV_OVERWRITE
1709 Enable overwrite of previous console environment settings.
1711 - CFG_MEMTEST_START, CFG_MEMTEST_END:
1712 Begin and End addresses of the area used by the
1716 Enable an alternate, more extensive memory test.
1718 - CFG_MEMTEST_SCRATCH:
1719 Scratch address used by the alternate memory test
1720 You only need to set this if address zero isn't writeable
1722 - CFG_TFTP_LOADADDR:
1723 Default load address for network file downloads
1725 - CFG_LOADS_BAUD_CHANGE:
1726 Enable temporary baudrate change while serial download
1729 Physical start address of SDRAM. _Must_ be 0 here.
1732 Physical start address of Motherboard I/O (if using a
1736 Physical start address of Flash memory.
1739 Physical start address of boot monitor code (set by
1740 make config files to be same as the text base address
1741 (TEXT_BASE) used when linking) - same as
1742 CFG_FLASH_BASE when booting from flash.
1745 Size of memory reserved for monitor code, used to
1746 determine _at_compile_time_ (!) if the environment is
1747 embedded within the U-Boot image, or in a separate
1751 Size of DRAM reserved for malloc() use.
1754 Normally compressed uImages are limited to an
1755 uncompressed size of 8 MBytes. If this is not enough,
1756 you can define CFG_BOOTM_LEN in your board config file
1757 to adjust this setting to your needs.
1760 Maximum size of memory mapped by the startup code of
1761 the Linux kernel; all data that must be processed by
1762 the Linux kernel (bd_info, boot arguments, eventually
1763 initrd image) must be put below this limit.
1765 - CFG_MAX_FLASH_BANKS:
1766 Max number of Flash memory banks
1768 - CFG_MAX_FLASH_SECT:
1769 Max number of sectors on a Flash chip
1771 - CFG_FLASH_ERASE_TOUT:
1772 Timeout for Flash erase operations (in ms)
1774 - CFG_FLASH_WRITE_TOUT:
1775 Timeout for Flash write operations (in ms)
1777 - CFG_FLASH_LOCK_TOUT
1778 Timeout for Flash set sector lock bit operation (in ms)
1780 - CFG_FLASH_UNLOCK_TOUT
1781 Timeout for Flash clear lock bits operation (in ms)
1783 - CFG_FLASH_PROTECTION
1784 If defined, hardware flash sectors protection is used
1785 instead of U-Boot software protection.
1787 - CFG_DIRECT_FLASH_TFTP:
1789 Enable TFTP transfers directly to flash memory;
1790 without this option such a download has to be
1791 performed in two steps: (1) download to RAM, and (2)
1792 copy from RAM to flash.
1794 The two-step approach is usually more reliable, since
1795 you can check if the download worked before you erase
1796 the flash, but in some situations (when sytem RAM is
1797 too limited to allow for a tempory copy of the
1798 downloaded image) this option may be very useful.
1801 Define if the flash driver uses extra elements in the
1802 common flash structure for storing flash geometry.
1804 - CFG_FLASH_CFI_DRIVER
1805 This option also enables the building of the cfi_flash driver
1806 in the drivers directory
1808 - CFG_FLASH_QUIET_TEST
1809 If this option is defined, the common CFI flash doesn't
1810 print it's warning upon not recognized FLASH banks. This
1811 is useful, if some of the configured banks are only
1812 optionally available.
1814 - CFG_RX_ETH_BUFFER:
1815 Defines the number of ethernet receive buffers. On some
1816 ethernet controllers it is recommended to set this value
1817 to 8 or even higher (EEPRO100 or 405 EMAC), since all
1818 buffers can be full shortly after enabling the interface
1819 on high ethernet traffic.
1820 Defaults to 4 if not defined.
1822 The following definitions that deal with the placement and management
1823 of environment data (variable area); in general, we support the
1824 following configurations:
1826 - CFG_ENV_IS_IN_FLASH:
1828 Define this if the environment is in flash memory.
1830 a) The environment occupies one whole flash sector, which is
1831 "embedded" in the text segment with the U-Boot code. This
1832 happens usually with "bottom boot sector" or "top boot
1833 sector" type flash chips, which have several smaller
1834 sectors at the start or the end. For instance, such a
1835 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In
1836 such a case you would place the environment in one of the
1837 4 kB sectors - with U-Boot code before and after it. With
1838 "top boot sector" type flash chips, you would put the
1839 environment in one of the last sectors, leaving a gap
1840 between U-Boot and the environment.
1844 Offset of environment data (variable area) to the
1845 beginning of flash memory; for instance, with bottom boot
1846 type flash chips the second sector can be used: the offset
1847 for this sector is given here.
1849 CFG_ENV_OFFSET is used relative to CFG_FLASH_BASE.
1853 This is just another way to specify the start address of
1854 the flash sector containing the environment (instead of
1857 - CFG_ENV_SECT_SIZE:
1859 Size of the sector containing the environment.
1862 b) Sometimes flash chips have few, equal sized, BIG sectors.
1863 In such a case you don't want to spend a whole sector for
1868 If you use this in combination with CFG_ENV_IS_IN_FLASH
1869 and CFG_ENV_SECT_SIZE, you can specify to use only a part
1870 of this flash sector for the environment. This saves
1871 memory for the RAM copy of the environment.
1873 It may also save flash memory if you decide to use this
1874 when your environment is "embedded" within U-Boot code,
1875 since then the remainder of the flash sector could be used
1876 for U-Boot code. It should be pointed out that this is
1877 STRONGLY DISCOURAGED from a robustness point of view:
1878 updating the environment in flash makes it always
1879 necessary to erase the WHOLE sector. If something goes
1880 wrong before the contents has been restored from a copy in
1881 RAM, your target system will be dead.
1883 - CFG_ENV_ADDR_REDUND
1886 These settings describe a second storage area used to hold
1887 a redundand copy of the environment data, so that there is
1888 a valid backup copy in case there is a power failure during
1889 a "saveenv" operation.
1891 BE CAREFUL! Any changes to the flash layout, and some changes to the
1892 source code will make it necessary to adapt <board>/u-boot.lds*
1896 - CFG_ENV_IS_IN_NVRAM:
1898 Define this if you have some non-volatile memory device
1899 (NVRAM, battery buffered SRAM) which you want to use for the
1905 These two #defines are used to determin the memory area you
1906 want to use for environment. It is assumed that this memory
1907 can just be read and written to, without any special
1910 BE CAREFUL! The first access to the environment happens quite early
1911 in U-Boot initalization (when we try to get the setting of for the
1912 console baudrate). You *MUST* have mappend your NVRAM area then, or
1915 Please note that even with NVRAM we still use a copy of the
1916 environment in RAM: we could work on NVRAM directly, but we want to
1917 keep settings there always unmodified except somebody uses "saveenv"
1918 to save the current settings.
1921 - CFG_ENV_IS_IN_EEPROM:
1923 Use this if you have an EEPROM or similar serial access
1924 device and a driver for it.
1929 These two #defines specify the offset and size of the
1930 environment area within the total memory of your EEPROM.
1932 - CFG_I2C_EEPROM_ADDR:
1933 If defined, specified the chip address of the EEPROM device.
1934 The default address is zero.
1936 - CFG_EEPROM_PAGE_WRITE_BITS:
1937 If defined, the number of bits used to address bytes in a
1938 single page in the EEPROM device. A 64 byte page, for example
1939 would require six bits.
1941 - CFG_EEPROM_PAGE_WRITE_DELAY_MS:
1942 If defined, the number of milliseconds to delay between
1943 page writes. The default is zero milliseconds.
1945 - CFG_I2C_EEPROM_ADDR_LEN:
1946 The length in bytes of the EEPROM memory array address. Note
1947 that this is NOT the chip address length!
1949 - CFG_I2C_EEPROM_ADDR_OVERFLOW:
1950 EEPROM chips that implement "address overflow" are ones
1951 like Catalyst 24WC04/08/16 which has 9/10/11 bits of
1952 address and the extra bits end up in the "chip address" bit
1953 slots. This makes a 24WC08 (1Kbyte) chip look like four 256
1956 Note that we consider the length of the address field to
1957 still be one byte because the extra address bits are hidden
1958 in the chip address.
1961 The size in bytes of the EEPROM device.
1964 - CFG_ENV_IS_IN_DATAFLASH:
1966 Define this if you have a DataFlash memory device which you
1967 want to use for the environment.
1973 These three #defines specify the offset and size of the
1974 environment area within the total memory of your DataFlash placed
1975 at the specified address.
1977 - CFG_ENV_IS_IN_NAND:
1979 Define this if you have a NAND device which you want to use
1980 for the environment.
1985 These two #defines specify the offset and size of the environment
1986 area within the first NAND device.
1988 - CFG_ENV_OFFSET_REDUND
1990 This setting describes a second storage area of CFG_ENV_SIZE
1991 size used to hold a redundant copy of the environment data,
1992 so that there is a valid backup copy in case there is a
1993 power failure during a "saveenv" operation.
1995 Note: CFG_ENV_OFFSET and CFG_ENV_OFFSET_REDUND must be aligned
1996 to a block boundary, and CFG_ENV_SIZE must be a multiple of
1997 the NAND devices block size.
1999 - CFG_SPI_INIT_OFFSET
2001 Defines offset to the initial SPI buffer area in DPRAM. The
2002 area is used at an early stage (ROM part) if the environment
2003 is configured to reside in the SPI EEPROM: We need a 520 byte
2004 scratch DPRAM area. It is used between the two initialization
2005 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems
2006 to be a good choice since it makes it far enough from the
2007 start of the data area as well as from the stack pointer.
2009 Please note that the environment is read-only as long as the monitor
2010 has been relocated to RAM and a RAM copy of the environment has been
2011 created; also, when using EEPROM you will have to use getenv_r()
2012 until then to read environment variables.
2014 The environment is protected by a CRC32 checksum. Before the monitor
2015 is relocated into RAM, as a result of a bad CRC you will be working
2016 with the compiled-in default environment - *silently*!!! [This is
2017 necessary, because the first environment variable we need is the
2018 "baudrate" setting for the console - if we have a bad CRC, we don't
2019 have any device yet where we could complain.]
2021 Note: once the monitor has been relocated, then it will complain if
2022 the default environment is used; a new CRC is computed as soon as you
2023 use the "saveenv" command to store a valid environment.
2025 - CFG_FAULT_ECHO_LINK_DOWN:
2026 Echo the inverted Ethernet link state to the fault LED.
2028 Note: If this option is active, then CFG_FAULT_MII_ADDR
2029 also needs to be defined.
2031 - CFG_FAULT_MII_ADDR:
2032 MII address of the PHY to check for the Ethernet link state.
2034 - CFG_64BIT_VSPRINTF:
2035 Makes vsprintf (and all *printf functions) support printing
2036 of 64bit values by using the L quantifier
2038 - CFG_64BIT_STRTOUL:
2039 Adds simple_strtoull that returns a 64bit value
2041 Low Level (hardware related) configuration options:
2042 ---------------------------------------------------
2044 - CFG_CACHELINE_SIZE:
2045 Cache Line Size of the CPU.
2048 Default address of the IMMR after system reset.
2050 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU,
2051 and RPXsuper) to be able to adjust the position of
2052 the IMMR register after a reset.
2054 - Floppy Disk Support:
2055 CFG_FDC_DRIVE_NUMBER
2057 the default drive number (default value 0)
2061 defines the spacing between fdc chipset registers
2066 defines the offset of register from address. It
2067 depends on which part of the data bus is connected to
2068 the fdc chipset. (default value 0)
2070 If CFG_ISA_IO_STRIDE CFG_ISA_IO_OFFSET and
2071 CFG_FDC_DRIVE_NUMBER are undefined, they take their
2074 if CFG_FDC_HW_INIT is defined, then the function
2075 fdc_hw_init() is called at the beginning of the FDC
2076 setup. fdc_hw_init() must be provided by the board
2077 source code. It is used to make hardware dependant
2080 - CFG_IMMR: Physical address of the Internal Memory.
2081 DO NOT CHANGE unless you know exactly what you're
2082 doing! (11-4) [MPC8xx/82xx systems only]
2084 - CFG_INIT_RAM_ADDR:
2086 Start address of memory area that can be used for
2087 initial data and stack; please note that this must be
2088 writable memory that is working WITHOUT special
2089 initialization, i. e. you CANNOT use normal RAM which
2090 will become available only after programming the
2091 memory controller and running certain initialization
2094 U-Boot uses the following memory types:
2095 - MPC8xx and MPC8260: IMMR (internal memory of the CPU)
2096 - MPC824X: data cache
2097 - PPC4xx: data cache
2099 - CFG_GBL_DATA_OFFSET:
2101 Offset of the initial data structure in the memory
2102 area defined by CFG_INIT_RAM_ADDR. Usually
2103 CFG_GBL_DATA_OFFSET is chosen such that the initial
2104 data is located at the end of the available space
2105 (sometimes written as (CFG_INIT_RAM_END -
2106 CFG_INIT_DATA_SIZE), and the initial stack is just
2107 below that area (growing from (CFG_INIT_RAM_ADDR +
2108 CFG_GBL_DATA_OFFSET) downward.
2111 On the MPC824X (or other systems that use the data
2112 cache for initial memory) the address chosen for
2113 CFG_INIT_RAM_ADDR is basically arbitrary - it must
2114 point to an otherwise UNUSED address space between
2115 the top of RAM and the start of the PCI space.
2117 - CFG_SIUMCR: SIU Module Configuration (11-6)
2119 - CFG_SYPCR: System Protection Control (11-9)
2121 - CFG_TBSCR: Time Base Status and Control (11-26)
2123 - CFG_PISCR: Periodic Interrupt Status and Control (11-31)
2125 - CFG_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30)
2127 - CFG_SCCR: System Clock and reset Control Register (15-27)
2129 - CFG_OR_TIMING_SDRAM:
2133 periodic timer for refresh
2135 - CFG_DER: Debug Event Register (37-47)
2137 - FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CFG_REMAP_OR_AM,
2138 CFG_PRELIM_OR_AM, CFG_OR_TIMING_FLASH, CFG_OR0_REMAP,
2139 CFG_OR0_PRELIM, CFG_BR0_PRELIM, CFG_OR1_REMAP, CFG_OR1_PRELIM,
2141 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
2143 - SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
2144 CFG_OR_TIMING_SDRAM, CFG_OR2_PRELIM, CFG_BR2_PRELIM,
2145 CFG_OR3_PRELIM, CFG_BR3_PRELIM:
2146 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
2148 - CFG_MAMR_PTA, CFG_MPTPR_2BK_4K, CFG_MPTPR_1BK_4K, CFG_MPTPR_2BK_8K,
2149 CFG_MPTPR_1BK_8K, CFG_MAMR_8COL, CFG_MAMR_9COL:
2150 Machine Mode Register and Memory Periodic Timer
2151 Prescaler definitions (SDRAM timing)
2153 - CFG_I2C_UCODE_PATCH, CFG_I2C_DPMEM_OFFSET [0x1FC0]:
2154 enable I2C microcode relocation patch (MPC8xx);
2155 define relocation offset in DPRAM [DSP2]
2157 - CFG_SPI_UCODE_PATCH, CFG_SPI_DPMEM_OFFSET [0x1FC0]:
2158 enable SPI microcode relocation patch (MPC8xx);
2159 define relocation offset in DPRAM [SCC4]
2162 Use OSCM clock mode on MBX8xx board. Be careful,
2163 wrong setting might damage your board. Read
2164 doc/README.MBX before setting this variable!
2166 - CFG_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only)
2167 Offset of the bootmode word in DPRAM used by post
2168 (Power On Self Tests). This definition overrides
2169 #define'd default value in commproc.h resp.
2172 - CFG_PCI_SLV_MEM_LOCAL, CFG_PCI_SLV_MEM_BUS, CFG_PICMR0_MASK_ATTRIB,
2173 CFG_PCI_MSTR0_LOCAL, CFG_PCIMSK0_MASK, CFG_PCI_MSTR1_LOCAL,
2174 CFG_PCIMSK1_MASK, CFG_PCI_MSTR_MEM_LOCAL, CFG_PCI_MSTR_MEM_BUS,
2175 CFG_CPU_PCI_MEM_START, CFG_PCI_MSTR_MEM_SIZE, CFG_POCMR0_MASK_ATTRIB,
2176 CFG_PCI_MSTR_MEMIO_LOCAL, CFG_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START,
2177 CFG_PCI_MSTR_MEMIO_SIZE, CFG_POCMR1_MASK_ATTRIB, CFG_PCI_MSTR_IO_LOCAL,
2178 CFG_PCI_MSTR_IO_BUS, CFG_CPU_PCI_IO_START, CFG_PCI_MSTR_IO_SIZE,
2179 CFG_POCMR2_MASK_ATTRIB: (MPC826x only)
2180 Overrides the default PCI memory map in cpu/mpc8260/pci.c if set.
2182 - CONFIG_ETHER_ON_FEC[12]
2183 Define to enable FEC[12] on a 8xx series processor.
2185 - CONFIG_FEC[12]_PHY
2186 Define to the hardcoded PHY address which corresponds
2187 to the given FEC; i. e.
2188 #define CONFIG_FEC1_PHY 4
2189 means that the PHY with address 4 is connected to FEC1
2191 When set to -1, means to probe for first available.
2193 - CONFIG_FEC[12]_PHY_NORXERR
2194 The PHY does not have a RXERR line (RMII only).
2195 (so program the FEC to ignore it).
2198 Enable RMII mode for all FECs.
2199 Note that this is a global option, we can't
2200 have one FEC in standard MII mode and another in RMII mode.
2202 - CONFIG_CRC32_VERIFY
2203 Add a verify option to the crc32 command.
2206 => crc32 -v <address> <count> <crc32>
2208 Where address/count indicate a memory area
2209 and crc32 is the correct crc32 which the
2213 Add the "loopw" memory command. This only takes effect if
2214 the memory commands are activated globally (CFG_CMD_MEM).
2217 Add the "mdc" and "mwc" memory commands. These are cyclic
2222 This command will print 4 bytes (10,11,12,13) each 500 ms.
2224 => mwc.l 100 12345678 10
2225 This command will write 12345678 to address 100 all 10 ms.
2227 This only takes effect if the memory commands are activated
2228 globally (CFG_CMD_MEM).
2230 - CONFIG_SKIP_LOWLEVEL_INIT
2231 - CONFIG_SKIP_RELOCATE_UBOOT
2233 [ARM only] If these variables are defined, then
2234 certain low level initializations (like setting up
2235 the memory controller) are omitted and/or U-Boot does
2236 not relocate itself into RAM.
2237 Normally these variables MUST NOT be defined. The
2238 only exception is when U-Boot is loaded (to RAM) by
2239 some other boot loader or by a debugger which
2240 performs these intializations itself.
2243 Building the Software:
2244 ======================
2246 Building U-Boot has been tested in native PPC environments (on a
2247 PowerBook G3 running LinuxPPC 2000) and in cross environments
2248 (running RedHat 6.x and 7.x Linux on x86, Solaris 2.6 on a SPARC, and
2251 If you are not using a native PPC environment, it is assumed that you
2252 have the GNU cross compiling tools available in your path and named
2253 with a prefix of "powerpc-linux-". If this is not the case, (e.g. if
2254 you are using Monta Vista's Hard Hat Linux CDK 1.2) you must change
2255 the definition of CROSS_COMPILE in Makefile. For HHL on a 4xx CPU,
2258 CROSS_COMPILE = ppc_4xx-
2261 U-Boot is intended to be simple to build. After installing the
2262 sources you must configure U-Boot for one specific board type. This
2267 where "NAME_config" is the name of one of the existing
2268 configurations; the following names are supported:
2270 ADCIOP_config FPS860L_config omap730p2_config
2271 ADS860_config GEN860T_config pcu_e_config
2273 AR405_config GENIETV_config PIP405_config
2274 at91rm9200dk_config GTH_config QS823_config
2275 CANBT_config hermes_config QS850_config
2276 cmi_mpc5xx_config hymod_config QS860T_config
2277 cogent_common_config IP860_config RPXlite_config
2278 cogent_mpc8260_config IVML24_config RPXlite_DW_config
2279 cogent_mpc8xx_config IVMS8_config RPXsuper_config
2280 CPCI405_config JSE_config rsdproto_config
2281 CPCIISER4_config LANTEC_config Sandpoint8240_config
2282 csb272_config lwmon_config sbc8260_config
2283 CU824_config MBX860T_config sbc8560_33_config
2284 DUET_ADS_config MBX_config sbc8560_66_config
2285 EBONY_config MPC8260ADS_config SM850_config
2286 ELPT860_config MPC8540ADS_config SPD823TS_config
2287 ESTEEM192E_config MPC8540EVAL_config stxgp3_config
2288 ETX094_config MPC8560ADS_config SXNI855T_config
2289 FADS823_config NETVIA_config TQM823L_config
2290 FADS850SAR_config omap1510inn_config TQM850L_config
2291 FADS860T_config omap1610h2_config TQM855L_config
2292 FPS850L_config omap1610inn_config TQM860L_config
2293 omap5912osk_config walnut_config
2294 omap2420h4_config Yukon8220_config
2297 Note: for some board special configuration names may exist; check if
2298 additional information is available from the board vendor; for
2299 instance, the TQM823L systems are available without (standard)
2300 or with LCD support. You can select such additional "features"
2301 when chosing the configuration, i. e.
2304 - will configure for a plain TQM823L, i. e. no LCD support
2306 make TQM823L_LCD_config
2307 - will configure for a TQM823L with U-Boot console on LCD
2312 Finally, type "make all", and you should get some working U-Boot
2313 images ready for download to / installation on your system:
2315 - "u-boot.bin" is a raw binary image
2316 - "u-boot" is an image in ELF binary format
2317 - "u-boot.srec" is in Motorola S-Record format
2320 Please be aware that the Makefiles assume you are using GNU make, so
2321 for instance on NetBSD you might need to use "gmake" instead of
2325 If the system board that you have is not listed, then you will need
2326 to port U-Boot to your hardware platform. To do this, follow these
2329 1. Add a new configuration option for your board to the toplevel
2330 "Makefile" and to the "MAKEALL" script, using the existing
2331 entries as examples. Note that here and at many other places
2332 boards and other names are listed in alphabetical sort order. Please
2334 2. Create a new directory to hold your board specific code. Add any
2335 files you need. In your board directory, you will need at least
2336 the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds".
2337 3. Create a new configuration file "include/configs/<board>.h" for
2339 3. If you're porting U-Boot to a new CPU, then also create a new
2340 directory to hold your CPU specific code. Add any files you need.
2341 4. Run "make <board>_config" with your new name.
2342 5. Type "make", and you should get a working "u-boot.srec" file
2343 to be installed on your target system.
2344 6. Debug and solve any problems that might arise.
2345 [Of course, this last step is much harder than it sounds.]
2348 Testing of U-Boot Modifications, Ports to New Hardware, etc.:
2349 ==============================================================
2351 If you have modified U-Boot sources (for instance added a new board
2352 or support for new devices, a new CPU, etc.) you are expected to
2353 provide feedback to the other developers. The feedback normally takes
2354 the form of a "patch", i. e. a context diff against a certain (latest
2355 official or latest in CVS) version of U-Boot sources.
2357 But before you submit such a patch, please verify that your modifi-
2358 cation did not break existing code. At least make sure that *ALL* of
2359 the supported boards compile WITHOUT ANY compiler warnings. To do so,
2360 just run the "MAKEALL" script, which will configure and build U-Boot
2361 for ALL supported system. Be warned, this will take a while. You can
2362 select which (cross) compiler to use by passing a `CROSS_COMPILE'
2363 environment variable to the script, i. e. to use the cross tools from
2364 MontaVista's Hard Hat Linux you can type
2366 CROSS_COMPILE=ppc_8xx- MAKEALL
2368 or to build on a native PowerPC system you can type
2370 CROSS_COMPILE=' ' MAKEALL
2372 See also "U-Boot Porting Guide" below.
2375 Monitor Commands - Overview:
2376 ============================
2378 go - start application at address 'addr'
2379 run - run commands in an environment variable
2380 bootm - boot application image from memory
2381 bootp - boot image via network using BootP/TFTP protocol
2382 tftpboot- boot image via network using TFTP protocol
2383 and env variables "ipaddr" and "serverip"
2384 (and eventually "gatewayip")
2385 rarpboot- boot image via network using RARP/TFTP protocol
2386 diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
2387 loads - load S-Record file over serial line
2388 loadb - load binary file over serial line (kermit mode)
2390 mm - memory modify (auto-incrementing)
2391 nm - memory modify (constant address)
2392 mw - memory write (fill)
2394 cmp - memory compare
2395 crc32 - checksum calculation
2396 imd - i2c memory display
2397 imm - i2c memory modify (auto-incrementing)
2398 inm - i2c memory modify (constant address)
2399 imw - i2c memory write (fill)
2400 icrc32 - i2c checksum calculation
2401 iprobe - probe to discover valid I2C chip addresses
2402 iloop - infinite loop on address range
2403 isdram - print SDRAM configuration information
2404 sspi - SPI utility commands
2405 base - print or set address offset
2406 printenv- print environment variables
2407 setenv - set environment variables
2408 saveenv - save environment variables to persistent storage
2409 protect - enable or disable FLASH write protection
2410 erase - erase FLASH memory
2411 flinfo - print FLASH memory information
2412 bdinfo - print Board Info structure
2413 iminfo - print header information for application image
2414 coninfo - print console devices and informations
2415 ide - IDE sub-system
2416 loop - infinite loop on address range
2417 loopw - infinite write loop on address range
2418 mtest - simple RAM test
2419 icache - enable or disable instruction cache
2420 dcache - enable or disable data cache
2421 reset - Perform RESET of the CPU
2422 echo - echo args to console
2423 version - print monitor version
2424 help - print online help
2425 ? - alias for 'help'
2428 Monitor Commands - Detailed Description:
2429 ========================================
2433 For now: just type "help <command>".
2436 Environment Variables:
2437 ======================
2439 U-Boot supports user configuration using Environment Variables which
2440 can be made persistent by saving to Flash memory.
2442 Environment Variables are set using "setenv", printed using
2443 "printenv", and saved to Flash using "saveenv". Using "setenv"
2444 without a value can be used to delete a variable from the
2445 environment. As long as you don't save the environment you are
2446 working with an in-memory copy. In case the Flash area containing the
2447 environment is erased by accident, a default environment is provided.
2449 Some configuration options can be set using Environment Variables:
2451 baudrate - see CONFIG_BAUDRATE
2453 bootdelay - see CONFIG_BOOTDELAY
2455 bootcmd - see CONFIG_BOOTCOMMAND
2457 bootargs - Boot arguments when booting an RTOS image
2459 bootfile - Name of the image to load with TFTP
2461 autoload - if set to "no" (any string beginning with 'n'),
2462 "bootp" will just load perform a lookup of the
2463 configuration from the BOOTP server, but not try to
2464 load any image using TFTP
2466 autostart - if set to "yes", an image loaded using the "bootp",
2467 "rarpboot", "tftpboot" or "diskboot" commands will
2468 be automatically started (by internally calling
2471 If set to "no", a standalone image passed to the
2472 "bootm" command will be copied to the load address
2473 (and eventually uncompressed), but NOT be started.
2474 This can be used to load and uncompress arbitrary
2477 i2cfast - (PPC405GP|PPC405EP only)
2478 if set to 'y' configures Linux I2C driver for fast
2479 mode (400kHZ). This environment variable is used in
2480 initialization code. So, for changes to be effective
2481 it must be saved and board must be reset.
2483 initrd_high - restrict positioning of initrd images:
2484 If this variable is not set, initrd images will be
2485 copied to the highest possible address in RAM; this
2486 is usually what you want since it allows for
2487 maximum initrd size. If for some reason you want to
2488 make sure that the initrd image is loaded below the
2489 CFG_BOOTMAPSZ limit, you can set this environment
2490 variable to a value of "no" or "off" or "0".
2491 Alternatively, you can set it to a maximum upper
2492 address to use (U-Boot will still check that it
2493 does not overwrite the U-Boot stack and data).
2495 For instance, when you have a system with 16 MB
2496 RAM, and want to reserve 4 MB from use by Linux,
2497 you can do this by adding "mem=12M" to the value of
2498 the "bootargs" variable. However, now you must make
2499 sure that the initrd image is placed in the first
2500 12 MB as well - this can be done with
2502 setenv initrd_high 00c00000
2504 If you set initrd_high to 0xFFFFFFFF, this is an
2505 indication to U-Boot that all addresses are legal
2506 for the Linux kernel, including addresses in flash
2507 memory. In this case U-Boot will NOT COPY the
2508 ramdisk at all. This may be useful to reduce the
2509 boot time on your system, but requires that this
2510 feature is supported by your Linux kernel.
2512 ipaddr - IP address; needed for tftpboot command
2514 loadaddr - Default load address for commands like "bootp",
2515 "rarpboot", "tftpboot", "loadb" or "diskboot"
2517 loads_echo - see CONFIG_LOADS_ECHO
2519 serverip - TFTP server IP address; needed for tftpboot command
2521 bootretry - see CONFIG_BOOT_RETRY_TIME
2523 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
2525 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
2527 ethprime - When CONFIG_NET_MULTI is enabled controls which
2528 interface is used first.
2530 ethact - When CONFIG_NET_MULTI is enabled controls which
2531 interface is currently active. For example you
2532 can do the following
2534 => setenv ethact FEC ETHERNET
2535 => ping 192.168.0.1 # traffic sent on FEC ETHERNET
2536 => setenv ethact SCC ETHERNET
2537 => ping 10.0.0.1 # traffic sent on SCC ETHERNET
2539 netretry - When set to "no" each network operation will
2540 either succeed or fail without retrying.
2541 When set to "once" the network operation will
2542 fail when all the available network interfaces
2543 are tried once without success.
2544 Useful on scripts which control the retry operation
2547 tftpsrcport - If this is set, the value is used for TFTP's
2550 tftpdstport - If this is set, the value is used for TFTP's UDP
2551 destination port instead of the Well Know Port 69.
2553 vlan - When set to a value < 4095 the traffic over
2554 ethernet is encapsulated/received over 802.1q
2557 The following environment variables may be used and automatically
2558 updated by the network boot commands ("bootp" and "rarpboot"),
2559 depending the information provided by your boot server:
2561 bootfile - see above
2562 dnsip - IP address of your Domain Name Server
2563 dnsip2 - IP address of your secondary Domain Name Server
2564 gatewayip - IP address of the Gateway (Router) to use
2565 hostname - Target hostname
2567 netmask - Subnet Mask
2568 rootpath - Pathname of the root filesystem on the NFS server
2569 serverip - see above
2572 There are two special Environment Variables:
2574 serial# - contains hardware identification information such
2575 as type string and/or serial number
2576 ethaddr - Ethernet address
2578 These variables can be set only once (usually during manufacturing of
2579 the board). U-Boot refuses to delete or overwrite these variables
2580 once they have been set once.
2583 Further special Environment Variables:
2585 ver - Contains the U-Boot version string as printed
2586 with the "version" command. This variable is
2587 readonly (see CONFIG_VERSION_VARIABLE).
2590 Please note that changes to some configuration parameters may take
2591 only effect after the next boot (yes, that's just like Windoze :-).
2594 Command Line Parsing:
2595 =====================
2597 There are two different command line parsers available with U-Boot:
2598 the old "simple" one, and the much more powerful "hush" shell:
2600 Old, simple command line parser:
2601 --------------------------------
2603 - supports environment variables (through setenv / saveenv commands)
2604 - several commands on one line, separated by ';'
2605 - variable substitution using "... ${name} ..." syntax
2606 - special characters ('$', ';') can be escaped by prefixing with '\',
2608 setenv bootcmd bootm \${address}
2609 - You can also escape text by enclosing in single apostrophes, for example:
2610 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
2615 - similar to Bourne shell, with control structures like
2616 if...then...else...fi, for...do...done; while...do...done,
2617 until...do...done, ...
2618 - supports environment ("global") variables (through setenv / saveenv
2619 commands) and local shell variables (through standard shell syntax
2620 "name=value"); only environment variables can be used with "run"
2626 (1) If a command line (or an environment variable executed by a "run"
2627 command) contains several commands separated by semicolon, and
2628 one of these commands fails, then the remaining commands will be
2631 (2) If you execute several variables with one call to run (i. e.
2632 calling run with a list af variables as arguments), any failing
2633 command will cause "run" to terminate, i. e. the remaining
2634 variables are not executed.
2636 Note for Redundant Ethernet Interfaces:
2637 =======================================
2639 Some boards come with redundant ethernet interfaces; U-Boot supports
2640 such configurations and is capable of automatic selection of a
2641 "working" interface when needed. MAC assignment works as follows:
2643 Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
2644 MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
2645 "eth1addr" (=>eth1), "eth2addr", ...
2647 If the network interface stores some valid MAC address (for instance
2648 in SROM), this is used as default address if there is NO correspon-
2649 ding setting in the environment; if the corresponding environment
2650 variable is set, this overrides the settings in the card; that means:
2652 o If the SROM has a valid MAC address, and there is no address in the
2653 environment, the SROM's address is used.
2655 o If there is no valid address in the SROM, and a definition in the
2656 environment exists, then the value from the environment variable is
2659 o If both the SROM and the environment contain a MAC address, and
2660 both addresses are the same, this MAC address is used.
2662 o If both the SROM and the environment contain a MAC address, and the
2663 addresses differ, the value from the environment is used and a
2666 o If neither SROM nor the environment contain a MAC address, an error
2673 The "boot" commands of this monitor operate on "image" files which
2674 can be basicly anything, preceeded by a special header; see the
2675 definitions in include/image.h for details; basicly, the header
2676 defines the following image properties:
2678 * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
2679 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
2680 LynxOS, pSOS, QNX, RTEMS, ARTOS;
2681 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, ARTOS, LynxOS).
2682 * Target CPU Architecture (Provisions for Alpha, ARM, Intel x86,
2683 IA64, MIPS, NIOS, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
2684 Currently supported: ARM, Intel x86, MIPS, NIOS, PowerPC).
2685 * Compression Type (uncompressed, gzip, bzip2)
2691 The header is marked by a special Magic Number, and both the header
2692 and the data portions of the image are secured against corruption by
2699 Although U-Boot should support any OS or standalone application
2700 easily, the main focus has always been on Linux during the design of
2703 U-Boot includes many features that so far have been part of some
2704 special "boot loader" code within the Linux kernel. Also, any
2705 "initrd" images to be used are no longer part of one big Linux image;
2706 instead, kernel and "initrd" are separate images. This implementation
2707 serves several purposes:
2709 - the same features can be used for other OS or standalone
2710 applications (for instance: using compressed images to reduce the
2711 Flash memory footprint)
2713 - it becomes much easier to port new Linux kernel versions because
2714 lots of low-level, hardware dependent stuff are done by U-Boot
2716 - the same Linux kernel image can now be used with different "initrd"
2717 images; of course this also means that different kernel images can
2718 be run with the same "initrd". This makes testing easier (you don't
2719 have to build a new "zImage.initrd" Linux image when you just
2720 change a file in your "initrd"). Also, a field-upgrade of the
2721 software is easier now.
2727 Porting Linux to U-Boot based systems:
2728 ---------------------------------------
2730 U-Boot cannot save you from doing all the necessary modifications to
2731 configure the Linux device drivers for use with your target hardware
2732 (no, we don't intend to provide a full virtual machine interface to
2735 But now you can ignore ALL boot loader code (in arch/ppc/mbxboot).
2737 Just make sure your machine specific header file (for instance
2738 include/asm-ppc/tqm8xx.h) includes the same definition of the Board
2739 Information structure as we define in include/u-boot.h, and make
2740 sure that your definition of IMAP_ADDR uses the same value as your
2741 U-Boot configuration in CFG_IMMR.
2744 Configuring the Linux kernel:
2745 -----------------------------
2747 No specific requirements for U-Boot. Make sure you have some root
2748 device (initial ramdisk, NFS) for your target system.
2751 Building a Linux Image:
2752 -----------------------
2754 With U-Boot, "normal" build targets like "zImage" or "bzImage" are
2755 not used. If you use recent kernel source, a new build target
2756 "uImage" will exist which automatically builds an image usable by
2757 U-Boot. Most older kernels also have support for a "pImage" target,
2758 which was introduced for our predecessor project PPCBoot and uses a
2759 100% compatible format.
2768 The "uImage" build target uses a special tool (in 'tools/mkimage') to
2769 encapsulate a compressed Linux kernel image with header information,
2770 CRC32 checksum etc. for use with U-Boot. This is what we are doing:
2772 * build a standard "vmlinux" kernel image (in ELF binary format):
2774 * convert the kernel into a raw binary image:
2776 ${CROSS_COMPILE}-objcopy -O binary \
2777 -R .note -R .comment \
2778 -S vmlinux linux.bin
2780 * compress the binary image:
2784 * package compressed binary image for U-Boot:
2786 mkimage -A ppc -O linux -T kernel -C gzip \
2787 -a 0 -e 0 -n "Linux Kernel Image" \
2788 -d linux.bin.gz uImage
2791 The "mkimage" tool can also be used to create ramdisk images for use
2792 with U-Boot, either separated from the Linux kernel image, or
2793 combined into one file. "mkimage" encapsulates the images with a 64
2794 byte header containing information about target architecture,
2795 operating system, image type, compression method, entry points, time
2796 stamp, CRC32 checksums, etc.
2798 "mkimage" can be called in two ways: to verify existing images and
2799 print the header information, or to build new images.
2801 In the first form (with "-l" option) mkimage lists the information
2802 contained in the header of an existing U-Boot image; this includes
2803 checksum verification:
2805 tools/mkimage -l image
2806 -l ==> list image header information
2808 The second form (with "-d" option) is used to build a U-Boot image
2809 from a "data file" which is used as image payload:
2811 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
2812 -n name -d data_file image
2813 -A ==> set architecture to 'arch'
2814 -O ==> set operating system to 'os'
2815 -T ==> set image type to 'type'
2816 -C ==> set compression type 'comp'
2817 -a ==> set load address to 'addr' (hex)
2818 -e ==> set entry point to 'ep' (hex)
2819 -n ==> set image name to 'name'
2820 -d ==> use image data from 'datafile'
2822 Right now, all Linux kernels for PowerPC systems use the same load
2823 address (0x00000000), but the entry point address depends on the
2826 - 2.2.x kernels have the entry point at 0x0000000C,
2827 - 2.3.x and later kernels have the entry point at 0x00000000.
2829 So a typical call to build a U-Boot image would read:
2831 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
2832 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
2833 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux.gz \
2834 > examples/uImage.TQM850L
2835 Image Name: 2.4.4 kernel for TQM850L
2836 Created: Wed Jul 19 02:34:59 2000
2837 Image Type: PowerPC Linux Kernel Image (gzip compressed)
2838 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
2839 Load Address: 0x00000000
2840 Entry Point: 0x00000000
2842 To verify the contents of the image (or check for corruption):
2844 -> tools/mkimage -l examples/uImage.TQM850L
2845 Image Name: 2.4.4 kernel for TQM850L
2846 Created: Wed Jul 19 02:34:59 2000
2847 Image Type: PowerPC Linux Kernel Image (gzip compressed)
2848 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
2849 Load Address: 0x00000000
2850 Entry Point: 0x00000000
2852 NOTE: for embedded systems where boot time is critical you can trade
2853 speed for memory and install an UNCOMPRESSED image instead: this
2854 needs more space in Flash, but boots much faster since it does not
2855 need to be uncompressed:
2857 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux.gz
2858 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
2859 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
2860 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux \
2861 > examples/uImage.TQM850L-uncompressed
2862 Image Name: 2.4.4 kernel for TQM850L
2863 Created: Wed Jul 19 02:34:59 2000
2864 Image Type: PowerPC Linux Kernel Image (uncompressed)
2865 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
2866 Load Address: 0x00000000
2867 Entry Point: 0x00000000
2870 Similar you can build U-Boot images from a 'ramdisk.image.gz' file
2871 when your kernel is intended to use an initial ramdisk:
2873 -> tools/mkimage -n 'Simple Ramdisk Image' \
2874 > -A ppc -O linux -T ramdisk -C gzip \
2875 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
2876 Image Name: Simple Ramdisk Image
2877 Created: Wed Jan 12 14:01:50 2000
2878 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
2879 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
2880 Load Address: 0x00000000
2881 Entry Point: 0x00000000
2884 Installing a Linux Image:
2885 -------------------------
2887 To downloading a U-Boot image over the serial (console) interface,
2888 you must convert the image to S-Record format:
2890 objcopy -I binary -O srec examples/image examples/image.srec
2892 The 'objcopy' does not understand the information in the U-Boot
2893 image header, so the resulting S-Record file will be relative to
2894 address 0x00000000. To load it to a given address, you need to
2895 specify the target address as 'offset' parameter with the 'loads'
2898 Example: install the image to address 0x40100000 (which on the
2899 TQM8xxL is in the first Flash bank):
2901 => erase 40100000 401FFFFF
2907 ## Ready for S-Record download ...
2908 ~>examples/image.srec
2909 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
2911 15989 15990 15991 15992
2912 [file transfer complete]
2914 ## Start Addr = 0x00000000
2917 You can check the success of the download using the 'iminfo' command;
2918 this includes a checksum verification so you can be sure no data
2919 corruption happened:
2923 ## Checking Image at 40100000 ...
2924 Image Name: 2.2.13 for initrd on TQM850L
2925 Image Type: PowerPC Linux Kernel Image (gzip compressed)
2926 Data Size: 335725 Bytes = 327 kB = 0 MB
2927 Load Address: 00000000
2928 Entry Point: 0000000c
2929 Verifying Checksum ... OK
2935 The "bootm" command is used to boot an application that is stored in
2936 memory (RAM or Flash). In case of a Linux kernel image, the contents
2937 of the "bootargs" environment variable is passed to the kernel as
2938 parameters. You can check and modify this variable using the
2939 "printenv" and "setenv" commands:
2942 => printenv bootargs
2943 bootargs=root=/dev/ram
2945 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
2947 => printenv bootargs
2948 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
2951 ## Booting Linux kernel at 40020000 ...
2952 Image Name: 2.2.13 for NFS on TQM850L
2953 Image Type: PowerPC Linux Kernel Image (gzip compressed)
2954 Data Size: 381681 Bytes = 372 kB = 0 MB
2955 Load Address: 00000000
2956 Entry Point: 0000000c
2957 Verifying Checksum ... OK
2958 Uncompressing Kernel Image ... OK
2959 Linux version 2.2.13 (wd@denx.local.net) (gcc version 2.95.2 19991024 (release)) #1 Wed Jul 19 02:35:17 MEST 2000
2960 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
2961 time_init: decrementer frequency = 187500000/60
2962 Calibrating delay loop... 49.77 BogoMIPS
2963 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
2966 If you want to boot a Linux kernel with initial ram disk, you pass
2967 the memory addresses of both the kernel and the initrd image (PPBCOOT
2968 format!) to the "bootm" command:
2970 => imi 40100000 40200000
2972 ## Checking Image at 40100000 ...
2973 Image Name: 2.2.13 for initrd on TQM850L
2974 Image Type: PowerPC Linux Kernel Image (gzip compressed)
2975 Data Size: 335725 Bytes = 327 kB = 0 MB
2976 Load Address: 00000000
2977 Entry Point: 0000000c
2978 Verifying Checksum ... OK
2980 ## Checking Image at 40200000 ...
2981 Image Name: Simple Ramdisk Image
2982 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
2983 Data Size: 566530 Bytes = 553 kB = 0 MB
2984 Load Address: 00000000
2985 Entry Point: 00000000
2986 Verifying Checksum ... OK
2988 => bootm 40100000 40200000
2989 ## Booting Linux kernel at 40100000 ...
2990 Image Name: 2.2.13 for initrd on TQM850L
2991 Image Type: PowerPC Linux Kernel Image (gzip compressed)
2992 Data Size: 335725 Bytes = 327 kB = 0 MB
2993 Load Address: 00000000
2994 Entry Point: 0000000c
2995 Verifying Checksum ... OK
2996 Uncompressing Kernel Image ... OK
2997 ## Loading RAMDisk Image at 40200000 ...
2998 Image Name: Simple Ramdisk Image
2999 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
3000 Data Size: 566530 Bytes = 553 kB = 0 MB
3001 Load Address: 00000000
3002 Entry Point: 00000000
3003 Verifying Checksum ... OK
3004 Loading Ramdisk ... OK
3005 Linux version 2.2.13 (wd@denx.local.net) (gcc version 2.95.2 19991024 (release)) #1 Wed Jul 19 02:32:08 MEST 2000
3006 Boot arguments: root=/dev/ram
3007 time_init: decrementer frequency = 187500000/60
3008 Calibrating delay loop... 49.77 BogoMIPS
3010 RAMDISK: Compressed image found at block 0
3011 VFS: Mounted root (ext2 filesystem).
3015 More About U-Boot Image Types:
3016 ------------------------------
3018 U-Boot supports the following image types:
3020 "Standalone Programs" are directly runnable in the environment
3021 provided by U-Boot; it is expected that (if they behave
3022 well) you can continue to work in U-Boot after return from
3023 the Standalone Program.
3024 "OS Kernel Images" are usually images of some Embedded OS which
3025 will take over control completely. Usually these programs
3026 will install their own set of exception handlers, device
3027 drivers, set up the MMU, etc. - this means, that you cannot
3028 expect to re-enter U-Boot except by resetting the CPU.
3029 "RAMDisk Images" are more or less just data blocks, and their
3030 parameters (address, size) are passed to an OS kernel that is
3032 "Multi-File Images" contain several images, typically an OS
3033 (Linux) kernel image and one or more data images like
3034 RAMDisks. This construct is useful for instance when you want
3035 to boot over the network using BOOTP etc., where the boot
3036 server provides just a single image file, but you want to get
3037 for instance an OS kernel and a RAMDisk image.
3039 "Multi-File Images" start with a list of image sizes, each
3040 image size (in bytes) specified by an "uint32_t" in network
3041 byte order. This list is terminated by an "(uint32_t)0".
3042 Immediately after the terminating 0 follow the images, one by
3043 one, all aligned on "uint32_t" boundaries (size rounded up to
3044 a multiple of 4 bytes).
3046 "Firmware Images" are binary images containing firmware (like
3047 U-Boot or FPGA images) which usually will be programmed to
3050 "Script files" are command sequences that will be executed by
3051 U-Boot's command interpreter; this feature is especially
3052 useful when you configure U-Boot to use a real shell (hush)
3053 as command interpreter.
3059 One of the features of U-Boot is that you can dynamically load and
3060 run "standalone" applications, which can use some resources of
3061 U-Boot like console I/O functions or interrupt services.
3063 Two simple examples are included with the sources:
3068 'examples/hello_world.c' contains a small "Hello World" Demo
3069 application; it is automatically compiled when you build U-Boot.
3070 It's configured to run at address 0x00040004, so you can play with it
3074 ## Ready for S-Record download ...
3075 ~>examples/hello_world.srec
3076 1 2 3 4 5 6 7 8 9 10 11 ...
3077 [file transfer complete]
3079 ## Start Addr = 0x00040004
3081 => go 40004 Hello World! This is a test.
3082 ## Starting application at 0x00040004 ...
3093 Hit any key to exit ...
3095 ## Application terminated, rc = 0x0
3097 Another example, which demonstrates how to register a CPM interrupt
3098 handler with the U-Boot code, can be found in 'examples/timer.c'.
3099 Here, a CPM timer is set up to generate an interrupt every second.
3100 The interrupt service routine is trivial, just printing a '.'
3101 character, but this is just a demo program. The application can be
3102 controlled by the following keys:
3104 ? - print current values og the CPM Timer registers
3105 b - enable interrupts and start timer
3106 e - stop timer and disable interrupts
3107 q - quit application
3110 ## Ready for S-Record download ...
3111 ~>examples/timer.srec
3112 1 2 3 4 5 6 7 8 9 10 11 ...
3113 [file transfer complete]
3115 ## Start Addr = 0x00040004
3118 ## Starting application at 0x00040004 ...
3121 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
3124 [q, b, e, ?] Set interval 1000000 us
3127 [q, b, e, ?] ........
3128 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
3131 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
3134 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
3137 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
3139 [q, b, e, ?] ...Stopping timer
3141 [q, b, e, ?] ## Application terminated, rc = 0x0
3147 Over time, many people have reported problems when trying to use the
3148 "minicom" terminal emulation program for serial download. I (wd)
3149 consider minicom to be broken, and recommend not to use it. Under
3150 Unix, I recommend to use C-Kermit for general purpose use (and
3151 especially for kermit binary protocol download ("loadb" command), and
3152 use "cu" for S-Record download ("loads" command).
3154 Nevertheless, if you absolutely want to use it try adding this
3155 configuration to your "File transfer protocols" section:
3157 Name Program Name U/D FullScr IO-Red. Multi
3158 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
3159 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
3165 Starting at version 0.9.2, U-Boot supports NetBSD both as host
3166 (build U-Boot) and target system (boots NetBSD/mpc8xx).
3168 Building requires a cross environment; it is known to work on
3169 NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
3170 need gmake since the Makefiles are not compatible with BSD make).
3171 Note that the cross-powerpc package does not install include files;
3172 attempting to build U-Boot will fail because <machine/ansi.h> is
3173 missing. This file has to be installed and patched manually:
3175 # cd /usr/pkg/cross/powerpc-netbsd/include
3177 # ln -s powerpc machine
3178 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
3179 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
3181 Native builds *don't* work due to incompatibilities between native
3182 and U-Boot include files.
3184 Booting assumes that (the first part of) the image booted is a
3185 stage-2 loader which in turn loads and then invokes the kernel
3186 proper. Loader sources will eventually appear in the NetBSD source
3187 tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
3188 meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz
3191 Implementation Internals:
3192 =========================
3194 The following is not intended to be a complete description of every
3195 implementation detail. However, it should help to understand the
3196 inner workings of U-Boot and make it easier to port it to custom
3200 Initial Stack, Global Data:
3201 ---------------------------
3203 The implementation of U-Boot is complicated by the fact that U-Boot
3204 starts running out of ROM (flash memory), usually without access to
3205 system RAM (because the memory controller is not initialized yet).
3206 This means that we don't have writable Data or BSS segments, and BSS
3207 is not initialized as zero. To be able to get a C environment working
3208 at all, we have to allocate at least a minimal stack. Implementation
3209 options for this are defined and restricted by the CPU used: Some CPU
3210 models provide on-chip memory (like the IMMR area on MPC8xx and
3211 MPC826x processors), on others (parts of) the data cache can be
3212 locked as (mis-) used as memory, etc.
3214 Chris Hallinan posted a good summary of these issues to the
3215 u-boot-users mailing list:
3217 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
3218 From: "Chris Hallinan" <clh@net1plus.com>
3219 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
3222 Correct me if I'm wrong, folks, but the way I understand it
3223 is this: Using DCACHE as initial RAM for Stack, etc, does not
3224 require any physical RAM backing up the cache. The cleverness
3225 is that the cache is being used as a temporary supply of
3226 necessary storage before the SDRAM controller is setup. It's
3227 beyond the scope of this list to expain the details, but you
3228 can see how this works by studying the cache architecture and
3229 operation in the architecture and processor-specific manuals.
3231 OCM is On Chip Memory, which I believe the 405GP has 4K. It
3232 is another option for the system designer to use as an
3233 initial stack/ram area prior to SDRAM being available. Either
3234 option should work for you. Using CS 4 should be fine if your
3235 board designers haven't used it for something that would
3236 cause you grief during the initial boot! It is frequently not
3239 CFG_INIT_RAM_ADDR should be somewhere that won't interfere
3240 with your processor/board/system design. The default value
3241 you will find in any recent u-boot distribution in
3242 walnut.h should work for you. I'd set it to a value larger
3243 than your SDRAM module. If you have a 64MB SDRAM module, set
3244 it above 400_0000. Just make sure your board has no resources
3245 that are supposed to respond to that address! That code in
3246 start.S has been around a while and should work as is when
3247 you get the config right.
3252 It is essential to remember this, since it has some impact on the C
3253 code for the initialization procedures:
3255 * Initialized global data (data segment) is read-only. Do not attempt
3258 * Do not use any unitialized global data (or implicitely initialized
3259 as zero data - BSS segment) at all - this is undefined, initiali-
3260 zation is performed later (when relocating to RAM).
3262 * Stack space is very limited. Avoid big data buffers or things like
3265 Having only the stack as writable memory limits means we cannot use
3266 normal global data to share information beween the code. But it
3267 turned out that the implementation of U-Boot can be greatly
3268 simplified by making a global data structure (gd_t) available to all
3269 functions. We could pass a pointer to this data as argument to _all_
3270 functions, but this would bloat the code. Instead we use a feature of
3271 the GCC compiler (Global Register Variables) to share the data: we
3272 place a pointer (gd) to the global data into a register which we
3273 reserve for this purpose.
3275 When choosing a register for such a purpose we are restricted by the
3276 relevant (E)ABI specifications for the current architecture, and by
3277 GCC's implementation.
3279 For PowerPC, the following registers have specific use:
3282 R3-R4: parameter passing and return values
3283 R5-R10: parameter passing
3284 R13: small data area pointer
3288 (U-Boot also uses R14 as internal GOT pointer.)
3290 ==> U-Boot will use R29 to hold a pointer to the global data
3292 Note: on PPC, we could use a static initializer (since the
3293 address of the global data structure is known at compile time),
3294 but it turned out that reserving a register results in somewhat
3295 smaller code - although the code savings are not that big (on
3296 average for all boards 752 bytes for the whole U-Boot image,
3297 624 text + 127 data).
3299 On ARM, the following registers are used:
3301 R0: function argument word/integer result
3302 R1-R3: function argument word
3304 R10: stack limit (used only if stack checking if enabled)
3305 R11: argument (frame) pointer
3306 R12: temporary workspace
3309 R15: program counter
3311 ==> U-Boot will use R8 to hold a pointer to the global data
3313 NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope,
3314 or current versions of GCC may "optimize" the code too much.
3319 U-Boot runs in system state and uses physical addresses, i.e. the
3320 MMU is not used either for address mapping nor for memory protection.
3322 The available memory is mapped to fixed addresses using the memory
3323 controller. In this process, a contiguous block is formed for each
3324 memory type (Flash, SDRAM, SRAM), even when it consists of several
3325 physical memory banks.
3327 U-Boot is installed in the first 128 kB of the first Flash bank (on
3328 TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
3329 booting and sizing and initializing DRAM, the code relocates itself
3330 to the upper end of DRAM. Immediately below the U-Boot code some
3331 memory is reserved for use by malloc() [see CFG_MALLOC_LEN
3332 configuration setting]. Below that, a structure with global Board
3333 Info data is placed, followed by the stack (growing downward).
3335 Additionally, some exception handler code is copied to the low 8 kB
3336 of DRAM (0x00000000 ... 0x00001FFF).
3338 So a typical memory configuration with 16 MB of DRAM could look like
3341 0x0000 0000 Exception Vector code
3344 0x0000 2000 Free for Application Use
3350 0x00FB FF20 Monitor Stack (Growing downward)
3351 0x00FB FFAC Board Info Data and permanent copy of global data
3352 0x00FC 0000 Malloc Arena
3355 0x00FE 0000 RAM Copy of Monitor Code
3356 ... eventually: LCD or video framebuffer
3357 ... eventually: pRAM (Protected RAM - unchanged by reset)
3358 0x00FF FFFF [End of RAM]
3361 System Initialization:
3362 ----------------------
3364 In the reset configuration, U-Boot starts at the reset entry point
3365 (on most PowerPC systens at address 0x00000100). Because of the reset
3366 configuration for CS0# this is a mirror of the onboard Flash memory.
3367 To be able to re-map memory U-Boot then jumps to its link address.
3368 To be able to implement the initialization code in C, a (small!)
3369 initial stack is set up in the internal Dual Ported RAM (in case CPUs
3370 which provide such a feature like MPC8xx or MPC8260), or in a locked
3371 part of the data cache. After that, U-Boot initializes the CPU core,
3372 the caches and the SIU.
3374 Next, all (potentially) available memory banks are mapped using a
3375 preliminary mapping. For example, we put them on 512 MB boundaries
3376 (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
3377 on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
3378 programmed for SDRAM access. Using the temporary configuration, a
3379 simple memory test is run that determines the size of the SDRAM
3382 When there is more than one SDRAM bank, and the banks are of
3383 different size, the largest is mapped first. For equal size, the first
3384 bank (CS2#) is mapped first. The first mapping is always for address
3385 0x00000000, with any additional banks following immediately to create
3386 contiguous memory starting from 0.
3388 Then, the monitor installs itself at the upper end of the SDRAM area
3389 and allocates memory for use by malloc() and for the global Board
3390 Info data; also, the exception vector code is copied to the low RAM
3391 pages, and the final stack is set up.
3393 Only after this relocation will you have a "normal" C environment;
3394 until that you are restricted in several ways, mostly because you are
3395 running from ROM, and because the code will have to be relocated to a
3399 U-Boot Porting Guide:
3400 ----------------------
3402 [Based on messages by Jerry Van Baren in the U-Boot-Users mailing
3406 int main (int argc, char *argv[])
3408 sighandler_t no_more_time;
3410 signal (SIGALRM, no_more_time);
3411 alarm (PROJECT_DEADLINE - toSec (3 * WEEK));
3413 if (available_money > available_manpower) {
3414 pay consultant to port U-Boot;
3418 Download latest U-Boot source;
3420 Subscribe to u-boot-users mailing list;
3423 email ("Hi, I am new to U-Boot, how do I get started?");
3427 Read the README file in the top level directory;
3428 Read http://www.denx.de/twiki/bin/view/DULG/Manual ;
3429 Read the source, Luke;
3432 if (available_money > toLocalCurrency ($2500)) {
3435 Add a lot of aggravation and time;
3438 Create your own board support subdirectory;
3440 Create your own board config file;
3444 Add / modify source code;
3448 email ("Hi, I am having problems...");
3450 Send patch file to Wolfgang;
3455 void no_more_time (int sig)
3464 All contributions to U-Boot should conform to the Linux kernel
3465 coding style; see the file "Documentation/CodingStyle" in your Linux
3466 kernel source directory.
3468 Please note that U-Boot is implemented in C (and to some small parts
3469 in Assembler); no C++ is used, so please do not use C++ style
3470 comments (//) in your code.
3472 Please also stick to the following formatting rules:
3473 - remove any trailing white space
3474 - use TAB characters for indentation, not spaces
3475 - make sure NOT to use DOS '\r\n' line feeds
3476 - do not add more than 2 empty lines to source files
3477 - do not add trailing empty lines to source files
3479 Submissions which do not conform to the standards may be returned
3480 with a request to reformat the changes.
3486 Since the number of patches for U-Boot is growing, we need to
3487 establish some rules. Submissions which do not conform to these rules
3488 may be rejected, even when they contain important and valuable stuff.
3490 Patches shall be sent to the u-boot-users mailing list.
3492 When you send a patch, please include the following information with
3495 * For bug fixes: a description of the bug and how your patch fixes
3496 this bug. Please try to include a way of demonstrating that the
3497 patch actually fixes something.
3499 * For new features: a description of the feature and your
3502 * A CHANGELOG entry as plaintext (separate from the patch)
3504 * For major contributions, your entry to the CREDITS file
3506 * When you add support for a new board, don't forget to add this
3507 board to the MAKEALL script, too.
3509 * If your patch adds new configuration options, don't forget to
3510 document these in the README file.
3512 * The patch itself. If you are accessing the CVS repository use "cvs
3513 update; cvs diff -puRN"; else, use "diff -purN OLD NEW". If your
3514 version of diff does not support these options, then get the latest
3515 version of GNU diff.
3517 The current directory when running this command shall be the top
3518 level directory of the U-Boot source tree, or it's parent directory
3519 (i. e. please make sure that your patch includes sufficient
3520 directory information for the affected files).
3522 We accept patches as plain text, MIME attachments or as uuencoded
3525 * If one logical set of modifications affects or creates several
3526 files, all these changes shall be submitted in a SINGLE patch file.
3528 * Changesets that contain different, unrelated modifications shall be
3529 submitted as SEPARATE patches, one patch per changeset.
3534 * Before sending the patch, run the MAKEALL script on your patched
3535 source tree and make sure that no errors or warnings are reported
3536 for any of the boards.
3538 * Keep your modifications to the necessary minimum: A patch
3539 containing several unrelated changes or arbitrary reformats will be
3540 returned with a request to re-formatting / split it.
3542 * If you modify existing code, make sure that your new code does not
3543 add to the memory footprint of the code ;-) Small is beautiful!
3544 When adding new features, these should compile conditionally only
3545 (using #ifdef), and the resulting code with the new feature
3546 disabled must not need more memory than the old code without your
3549 * Remember that there is a size limit of 40 kB per message on the
3550 u-boot-users mailing list. Compression may help.
projects / platform / kernel / u-boot.git / blob