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_avr32 Files generic to AVR32 architecture
160 - lib_generic Files generic to all architectures
161 - lib_i386 Files generic to i386 architecture
162 - lib_m68k Files generic to m68k architecture
163 - lib_mips Files generic to MIPS architecture
164 - lib_nios Files generic to NIOS architecture
165 - lib_ppc Files generic to PowerPC architecture
166 - net Networking code
167 - post Power On Self Test
168 - rtc Real Time Clock drivers
169 - tools Tools to build S-Record or U-Boot images, etc.
171 Software Configuration:
172 =======================
174 Configuration is usually done using C preprocessor defines; the
175 rationale behind that is to avoid dead code whenever possible.
177 There are two classes of configuration variables:
179 * Configuration _OPTIONS_:
180 These are selectable by the user and have names beginning with
183 * Configuration _SETTINGS_:
184 These depend on the hardware etc. and should not be meddled with if
185 you don't know what you're doing; they have names beginning with
188 Later we will add a configuration tool - probably similar to or even
189 identical to what's used for the Linux kernel. Right now, we have to
190 do the configuration by hand, which means creating some symbolic
191 links and editing some configuration files. We use the TQM8xxL boards
195 Selection of Processor Architecture and Board Type:
196 ---------------------------------------------------
198 For all supported boards there are ready-to-use default
199 configurations available; just type "make <board_name>_config".
201 Example: For a TQM823L module type:
206 For the Cogent platform, you need to specify the cpu type as well;
207 e.g. "make cogent_mpc8xx_config". And also configure the cogent
208 directory according to the instructions in cogent/README.
211 Configuration Options:
212 ----------------------
214 Configuration depends on the combination of board and CPU type; all
215 such information is kept in a configuration file
216 "include/configs/<board_name>.h".
218 Example: For a TQM823L module, all configuration settings are in
219 "include/configs/TQM823L.h".
222 Many of the options are named exactly as the corresponding Linux
223 kernel configuration options. The intention is to make it easier to
224 build a config tool - later.
227 The following options need to be configured:
229 - CPU Type: Define exactly one of
233 CONFIG_MPC823, CONFIG_MPC850, CONFIG_MPC855, CONFIG_MPC860
236 or CONFIG_MPC824X, CONFIG_MPC8260
252 MicroBlaze based CPUs:
253 ----------------------
257 ----------------------
261 - Board Type: Define exactly one of
263 PowerPC based boards:
264 ---------------------
266 CONFIG_ADCIOP CONFIG_FPS860L CONFIG_OXC
267 CONFIG_ADS860 CONFIG_GEN860T CONFIG_PCI405
268 CONFIG_AMX860 CONFIG_GENIETV CONFIG_PCIPPC2
269 CONFIG_AP1000 CONFIG_GTH CONFIG_PCIPPC6
270 CONFIG_AR405 CONFIG_gw8260 CONFIG_pcu_e
271 CONFIG_BAB7xx CONFIG_hermes CONFIG_PIP405
272 CONFIG_BC3450 CONFIG_hymod CONFIG_PM826
273 CONFIG_c2mon CONFIG_IAD210 CONFIG_ppmc8260
274 CONFIG_CANBT CONFIG_ICU862 CONFIG_QS823
275 CONFIG_CCM CONFIG_IP860 CONFIG_QS850
276 CONFIG_CMI CONFIG_IPHASE4539 CONFIG_QS860T
277 CONFIG_cogent_mpc8260 CONFIG_IVML24 CONFIG_RBC823
278 CONFIG_cogent_mpc8xx CONFIG_IVML24_128 CONFIG_RPXClassic
279 CONFIG_CPCI405 CONFIG_IVML24_256 CONFIG_RPXlite
280 CONFIG_CPCI4052 CONFIG_IVMS8 CONFIG_RPXsuper
281 CONFIG_CPCIISER4 CONFIG_IVMS8_128 CONFIG_rsdproto
282 CONFIG_CPU86 CONFIG_IVMS8_256 CONFIG_sacsng
283 CONFIG_CRAYL1 CONFIG_JSE CONFIG_Sandpoint8240
284 CONFIG_CSB272 CONFIG_LANTEC CONFIG_Sandpoint8245
285 CONFIG_CU824 CONFIG_LITE5200B CONFIG_sbc8260
286 CONFIG_DASA_SIM CONFIG_lwmon CONFIG_sbc8560
287 CONFIG_DB64360 CONFIG_MBX CONFIG_SM850
288 CONFIG_DB64460 CONFIG_MBX860T CONFIG_SPD823TS
289 CONFIG_DU405 CONFIG_MHPC CONFIG_STXGP3
290 CONFIG_DUET_ADS CONFIG_MIP405 CONFIG_SXNI855T
291 CONFIG_EBONY CONFIG_MOUSSE CONFIG_TQM823L
292 CONFIG_ELPPC CONFIG_MPC8260ADS CONFIG_TQM8260
293 CONFIG_ELPT860 CONFIG_MPC8540ADS CONFIG_TQM850L
294 CONFIG_ep8260 CONFIG_MPC8540EVAL CONFIG_TQM855L
295 CONFIG_ERIC CONFIG_MPC8560ADS CONFIG_TQM860L
296 CONFIG_ESTEEM192E CONFIG_MUSENKI CONFIG_TTTech
297 CONFIG_ETX094 CONFIG_MVS1 CONFIG_UTX8245
298 CONFIG_EVB64260 CONFIG_NETPHONE CONFIG_V37
299 CONFIG_FADS823 CONFIG_NETTA CONFIG_W7OLMC
300 CONFIG_FADS850SAR CONFIG_NETVIA CONFIG_W7OLMG
301 CONFIG_FADS860T CONFIG_NX823 CONFIG_WALNUT
302 CONFIG_FLAGADM CONFIG_OCRTC CONFIG_ZPC1900
303 CONFIG_FPS850L CONFIG_ORSG CONFIG_ZUMA
308 CONFIG_ARMADILLO, CONFIG_AT91RM9200DK, CONFIG_CERF250,
309 CONFIG_CSB637, CONFIG_DELTA, CONFIG_DNP1110,
310 CONFIG_EP7312, CONFIG_H2_OMAP1610, CONFIG_HHP_CRADLE,
311 CONFIG_IMPA7, CONFIG_INNOVATOROMAP1510, CONFIG_INNOVATOROMAP1610,
312 CONFIG_KB9202, CONFIG_LART, CONFIG_LPD7A400,
313 CONFIG_LUBBOCK, CONFIG_OSK_OMAP5912, CONFIG_OMAP2420H4,
314 CONFIG_PLEB2, CONFIG_SHANNON, CONFIG_P2_OMAP730,
315 CONFIG_SMDK2400, CONFIG_SMDK2410, CONFIG_TRAB,
318 MicroBlaze based boards:
319 ------------------------
324 ------------------------
326 CONFIG_PCI5441 CONFIG_PK1C20
327 CONFIG_EP1C20 CONFIG_EP1S10 CONFIG_EP1S40
330 - CPU Module Type: (if CONFIG_COGENT is defined)
331 Define exactly one of
333 --- FIXME --- not tested yet:
334 CONFIG_CMA286_60, CONFIG_CMA286_21, CONFIG_CMA286_60P,
335 CONFIG_CMA287_23, CONFIG_CMA287_50
337 - Motherboard Type: (if CONFIG_COGENT is defined)
338 Define exactly one of
339 CONFIG_CMA101, CONFIG_CMA102
341 - Motherboard I/O Modules: (if CONFIG_COGENT is defined)
342 Define one or more of
345 - Motherboard Options: (if CONFIG_CMA101 or CONFIG_CMA102 are defined)
346 Define one or more of
347 CONFIG_LCD_HEARTBEAT - update a character position on
348 the lcd display every second with
351 - Board flavour: (if CONFIG_MPC8260ADS is defined)
354 CFG_8260ADS - original MPC8260ADS
355 CFG_8266ADS - MPC8266ADS
356 CFG_PQ2FADS - PQ2FADS-ZU or PQ2FADS-VR
357 CFG_8272ADS - MPC8272ADS
359 - MPC824X Family Member (if CONFIG_MPC824X is defined)
360 Define exactly one of
361 CONFIG_MPC8240, CONFIG_MPC8245
363 - 8xx CPU Options: (if using an MPC8xx cpu)
364 CONFIG_8xx_GCLK_FREQ - deprecated: CPU clock if
365 get_gclk_freq() cannot work
366 e.g. if there is no 32KHz
367 reference PIT/RTC clock
368 CONFIG_8xx_OSCLK - PLL input clock (either EXTCLK
371 - 859/866/885 CPU options: (if using a MPC859 or MPC866 or MPC885 CPU):
374 CONFIG_8xx_CPUCLK_DEFAULT
375 See doc/README.MPC866
379 Define this to measure the actual CPU clock instead
380 of relying on the correctness of the configured
381 values. Mostly useful for board bringup to make sure
382 the PLL is locked at the intended frequency. Note
383 that this requires a (stable) reference clock (32 kHz
384 RTC clock or CFG_8XX_XIN)
386 - Intel Monahans options:
387 CFG_MONAHANS_RUN_MODE_OSC_RATIO
389 Defines the Monahans run mode to oscillator
390 ratio. Valid values are 8, 16, 24, 31. The core
391 frequency is this value multiplied by 13 MHz.
393 CFG_MONAHANS_TURBO_RUN_MODE_RATIO
395 Defines the Monahans turbo mode to oscillator
396 ratio. Valid values are 1 (default if undefined) and
397 2. The core frequency as calculated above is multiplied
400 - Linux Kernel Interface:
403 U-Boot stores all clock information in Hz
404 internally. For binary compatibility with older Linux
405 kernels (which expect the clocks passed in the
406 bd_info data to be in MHz) the environment variable
407 "clocks_in_mhz" can be defined so that U-Boot
408 converts clock data to MHZ before passing it to the
410 When CONFIG_CLOCKS_IN_MHZ is defined, a definition of
411 "clocks_in_mhz=1" is automatically included in the
414 CONFIG_MEMSIZE_IN_BYTES [relevant for MIPS only]
416 When transfering memsize parameter to linux, some versions
417 expect it to be in bytes, others in MB.
418 Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes.
422 New kernel versions are expecting firmware settings to be
423 passed using flat open firmware trees.
424 The environment variable "disable_of", when set, disables this
427 CONFIG_OF_FLAT_TREE_MAX_SIZE
429 The maximum size of the constructed OF tree.
431 OF_CPU - The proper name of the cpus node.
432 OF_SOC - The proper name of the soc node.
433 OF_TBCLK - The timebase frequency.
434 OF_STDOUT_PATH - The path to the console device
438 The resulting flat device tree will have a copy of the bd_t.
439 Space should be pre-allocated in the dts for the bd_t.
441 CONFIG_OF_HAS_UBOOT_ENV
443 The resulting flat device tree will have a copy of u-boot's
444 environment variables
446 CONFIG_OF_BOARD_SETUP
448 Board code has addition modification that it wants to make
449 to the flat device tree before handing it off to the kernel
454 Define this if you want support for Amba PrimeCell PL010 UARTs.
458 Define this if you want support for Amba PrimeCell PL011 UARTs.
462 If you have Amba PrimeCell PL011 UARTs, set this variable to
463 the clock speed of the UARTs.
467 If you have Amba PrimeCell PL010 or PL011 UARTs on your board,
468 define this to a list of base addresses for each (supported)
469 port. See e.g. include/configs/versatile.h
473 Depending on board, define exactly one serial port
474 (like CONFIG_8xx_CONS_SMC1, CONFIG_8xx_CONS_SMC2,
475 CONFIG_8xx_CONS_SCC1, ...), or switch off the serial
476 console by defining CONFIG_8xx_CONS_NONE
478 Note: if CONFIG_8xx_CONS_NONE is defined, the serial
479 port routines must be defined elsewhere
480 (i.e. serial_init(), serial_getc(), ...)
483 Enables console device for a color framebuffer. Needs following
484 defines (cf. smiLynxEM, i8042, board/eltec/bab7xx)
485 VIDEO_FB_LITTLE_ENDIAN graphic memory organisation
487 VIDEO_HW_RECTFILL graphic chip supports
490 VIDEO_HW_BITBLT graphic chip supports
491 bit-blit (cf. smiLynxEM)
492 VIDEO_VISIBLE_COLS visible pixel columns
494 VIDEO_VISIBLE_ROWS visible pixel rows
495 VIDEO_PIXEL_SIZE bytes per pixel
496 VIDEO_DATA_FORMAT graphic data format
497 (0-5, cf. cfb_console.c)
498 VIDEO_FB_ADRS framebuffer address
499 VIDEO_KBD_INIT_FCT keyboard int fct
500 (i.e. i8042_kbd_init())
501 VIDEO_TSTC_FCT test char fct
503 VIDEO_GETC_FCT get char fct
505 CONFIG_CONSOLE_CURSOR cursor drawing on/off
506 (requires blink timer
508 CFG_CONSOLE_BLINK_COUNT blink interval (cf. i8042.c)
509 CONFIG_CONSOLE_TIME display time/date info in
511 (requires CFG_CMD_DATE)
512 CONFIG_VIDEO_LOGO display Linux logo in
514 CONFIG_VIDEO_BMP_LOGO use bmp_logo.h instead of
515 linux_logo.h for logo.
516 Requires CONFIG_VIDEO_LOGO
517 CONFIG_CONSOLE_EXTRA_INFO
518 addional board info beside
521 When CONFIG_CFB_CONSOLE is defined, video console is
522 default i/o. Serial console can be forced with
523 environment 'console=serial'.
525 When CONFIG_SILENT_CONSOLE is defined, all console
526 messages (by U-Boot and Linux!) can be silenced with
527 the "silent" environment variable. See
528 doc/README.silent for more information.
531 CONFIG_BAUDRATE - in bps
532 Select one of the baudrates listed in
533 CFG_BAUDRATE_TABLE, see below.
534 CFG_BRGCLK_PRESCALE, baudrate prescale
536 - Interrupt driven serial port input:
537 CONFIG_SERIAL_SOFTWARE_FIFO
540 Use an interrupt handler for receiving data on the
541 serial port. It also enables using hardware handshake
542 (RTS/CTS) and UART's built-in FIFO. Set the number of
543 bytes the interrupt driven input buffer should have.
545 Leave undefined to disable this feature, including
546 disable the buffer and hardware handshake.
548 - Console UART Number:
552 If defined internal UART1 (and not UART0) is used
553 as default U-Boot console.
555 - Boot Delay: CONFIG_BOOTDELAY - in seconds
556 Delay before automatically booting the default image;
557 set to -1 to disable autoboot.
559 See doc/README.autoboot for these options that
560 work with CONFIG_BOOTDELAY. None are required.
561 CONFIG_BOOT_RETRY_TIME
562 CONFIG_BOOT_RETRY_MIN
563 CONFIG_AUTOBOOT_KEYED
564 CONFIG_AUTOBOOT_PROMPT
565 CONFIG_AUTOBOOT_DELAY_STR
566 CONFIG_AUTOBOOT_STOP_STR
567 CONFIG_AUTOBOOT_DELAY_STR2
568 CONFIG_AUTOBOOT_STOP_STR2
569 CONFIG_ZERO_BOOTDELAY_CHECK
570 CONFIG_RESET_TO_RETRY
574 Only needed when CONFIG_BOOTDELAY is enabled;
575 define a command string that is automatically executed
576 when no character is read on the console interface
577 within "Boot Delay" after reset.
580 This can be used to pass arguments to the bootm
581 command. The value of CONFIG_BOOTARGS goes into the
582 environment value "bootargs".
584 CONFIG_RAMBOOT and CONFIG_NFSBOOT
585 The value of these goes into the environment as
586 "ramboot" and "nfsboot" respectively, and can be used
587 as a convenience, when switching between booting from
593 When this option is #defined, the existence of the
594 environment variable "preboot" will be checked
595 immediately before starting the CONFIG_BOOTDELAY
596 countdown and/or running the auto-boot command resp.
597 entering interactive mode.
599 This feature is especially useful when "preboot" is
600 automatically generated or modified. For an example
601 see the LWMON board specific code: here "preboot" is
602 modified when the user holds down a certain
603 combination of keys on the (special) keyboard when
606 - Serial Download Echo Mode:
608 If defined to 1, all characters received during a
609 serial download (using the "loads" command) are
610 echoed back. This might be needed by some terminal
611 emulations (like "cu"), but may as well just take
612 time on others. This setting #define's the initial
613 value of the "loads_echo" environment variable.
615 - Kgdb Serial Baudrate: (if CFG_CMD_KGDB is defined)
617 Select one of the baudrates listed in
618 CFG_BAUDRATE_TABLE, see below.
622 Most monitor functions can be selected (or
623 de-selected) by adjusting the definition of
624 CONFIG_COMMANDS; to select individual functions,
625 #define CONFIG_COMMANDS by "OR"ing any of the
628 #define enables commands:
629 -------------------------
630 CFG_CMD_ASKENV * ask for env variable
631 CFG_CMD_AUTOSCRIPT Autoscript Support
633 CFG_CMD_BEDBUG * Include BedBug Debugger
634 CFG_CMD_BMP * BMP support
635 CFG_CMD_BSP * Board specific commands
637 CFG_CMD_CACHE * icache, dcache
638 CFG_CMD_CONSOLE coninfo
639 CFG_CMD_DATE * support for RTC, date/time...
640 CFG_CMD_DHCP * DHCP support
641 CFG_CMD_DIAG * Diagnostics
642 CFG_CMD_DOC * Disk-On-Chip Support
643 CFG_CMD_DTT * Digital Therm and Thermostat
644 CFG_CMD_ECHO echo arguments
645 CFG_CMD_EEPROM * EEPROM read/write support
646 CFG_CMD_ELF * bootelf, bootvx
648 CFG_CMD_FDC * Floppy Disk Support
649 CFG_CMD_FAT * FAT partition support
650 CFG_CMD_FDOS * Dos diskette Support
651 CFG_CMD_FLASH flinfo, erase, protect
652 CFG_CMD_FPGA FPGA device initialization support
653 CFG_CMD_HWFLOW * RTS/CTS hw flow control
654 CFG_CMD_I2C * I2C serial bus support
655 CFG_CMD_IDE * IDE harddisk support
657 CFG_CMD_IMLS List all found images
658 CFG_CMD_IMMAP * IMMR dump support
659 CFG_CMD_IRQ * irqinfo
660 CFG_CMD_ITEST Integer/string test of 2 values
661 CFG_CMD_JFFS2 * JFFS2 Support
665 CFG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base,
667 CFG_CMD_MISC Misc functions like sleep etc
668 CFG_CMD_MMC * MMC memory mapped support
669 CFG_CMD_MII * MII utility commands
670 CFG_CMD_NAND * NAND support
671 CFG_CMD_NET bootp, tftpboot, rarpboot
672 CFG_CMD_PCI * pciinfo
673 CFG_CMD_PCMCIA * PCMCIA support
674 CFG_CMD_PING * send ICMP ECHO_REQUEST to network host
675 CFG_CMD_PORTIO * Port I/O
676 CFG_CMD_REGINFO * Register dump
677 CFG_CMD_RUN run command in env variable
678 CFG_CMD_SAVES * save S record dump
679 CFG_CMD_SCSI * SCSI Support
680 CFG_CMD_SDRAM * print SDRAM configuration information
681 (requires CFG_CMD_I2C)
682 CFG_CMD_SETGETDCR Support for DCR Register access (4xx only)
683 CFG_CMD_SPI * SPI serial bus support
684 CFG_CMD_USB * USB support
685 CFG_CMD_VFD * VFD support (TRAB)
686 CFG_CMD_BSP * Board SPecific functions
687 CFG_CMD_CDP * Cisco Discover Protocol support
688 -----------------------------------------------
691 CONFIG_CMD_DFL Default configuration; at the moment
692 this is includes all commands, except
693 the ones marked with "*" in the list
696 If you don't define CONFIG_COMMANDS it defaults to
697 CONFIG_CMD_DFL in include/cmd_confdefs.h. A board can
698 override the default settings in the respective
701 EXAMPLE: If you want all functions except of network
702 support you can write:
704 #define CONFIG_COMMANDS (CFG_CMD_ALL & ~CFG_CMD_NET)
707 Note: Don't enable the "icache" and "dcache" commands
708 (configuration option CFG_CMD_CACHE) unless you know
709 what you (and your U-Boot users) are doing. Data
710 cache cannot be enabled on systems like the 8xx or
711 8260 (where accesses to the IMMR region must be
712 uncached), and it cannot be disabled on all other
713 systems where we (mis-) use the data cache to hold an
714 initial stack and some data.
717 XXX - this list needs to get updated!
721 If this variable is defined, it enables watchdog
722 support. There must be support in the platform specific
723 code for a watchdog. For the 8xx and 8260 CPUs, the
724 SIU Watchdog feature is enabled in the SYPCR
728 CONFIG_VERSION_VARIABLE
729 If this variable is defined, an environment variable
730 named "ver" is created by U-Boot showing the U-Boot
731 version as printed by the "version" command.
732 This variable is readonly.
736 When CFG_CMD_DATE is selected, the type of the RTC
737 has to be selected, too. Define exactly one of the
740 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx
741 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC
742 CONFIG_RTC_MC146818 - use MC146818 RTC
743 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC
744 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC
745 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC
746 CONFIG_RTC_DS164x - use Dallas DS164x RTC
747 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC
749 Note that if the RTC uses I2C, then the I2C interface
750 must also be configured. See I2C Support, below.
754 When CONFIG_TIMESTAMP is selected, the timestamp
755 (date and time) of an image is printed by image
756 commands like bootm or iminfo. This option is
757 automatically enabled when you select CFG_CMD_DATE .
760 CONFIG_MAC_PARTITION and/or CONFIG_DOS_PARTITION
761 and/or CONFIG_ISO_PARTITION
763 If IDE or SCSI support is enabled (CFG_CMD_IDE or
764 CFG_CMD_SCSI) you must configure support for at least
765 one partition type as well.
768 CONFIG_IDE_RESET_ROUTINE - this is defined in several
769 board configurations files but used nowhere!
771 CONFIG_IDE_RESET - is this is defined, IDE Reset will
772 be performed by calling the function
773 ide_set_reset(int reset)
774 which has to be defined in a board specific file
779 Set this to enable ATAPI support.
784 Set this to enable support for disks larger than 137GB
785 Also look at CFG_64BIT_LBA ,CFG_64BIT_VSPRINTF and CFG_64BIT_STRTOUL
786 Whithout these , LBA48 support uses 32bit variables and will 'only'
787 support disks up to 2.1TB.
790 When enabled, makes the IDE subsystem use 64bit sector addresses.
794 At the moment only there is only support for the
795 SYM53C8XX SCSI controller; define
796 CONFIG_SCSI_SYM53C8XX to enable it.
798 CFG_SCSI_MAX_LUN [8], CFG_SCSI_MAX_SCSI_ID [7] and
799 CFG_SCSI_MAX_DEVICE [CFG_SCSI_MAX_SCSI_ID *
800 CFG_SCSI_MAX_LUN] can be adjusted to define the
801 maximum numbers of LUNs, SCSI ID's and target
803 CFG_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz)
805 - NETWORK Support (PCI):
807 Support for Intel 8254x gigabit chips.
810 Support for Intel 82557/82559/82559ER chips.
811 Optional CONFIG_EEPRO100_SROM_WRITE enables eeprom
812 write routine for first time initialisation.
815 Support for Digital 2114x chips.
816 Optional CONFIG_TULIP_SELECT_MEDIA for board specific
817 modem chip initialisation (KS8761/QS6611).
820 Support for National dp83815 chips.
823 Support for National dp8382[01] gigabit chips.
825 - NETWORK Support (other):
827 CONFIG_DRIVER_LAN91C96
828 Support for SMSC's LAN91C96 chips.
831 Define this to hold the physical address
832 of the LAN91C96's I/O space
834 CONFIG_LAN91C96_USE_32_BIT
835 Define this to enable 32 bit addressing
837 CONFIG_DRIVER_SMC91111
838 Support for SMSC's LAN91C111 chip
841 Define this to hold the physical address
842 of the device (I/O space)
844 CONFIG_SMC_USE_32_BIT
845 Define this if data bus is 32 bits
847 CONFIG_SMC_USE_IOFUNCS
848 Define this to use i/o functions instead of macros
849 (some hardware wont work with macros)
852 At the moment only the UHCI host controller is
853 supported (PIP405, MIP405, MPC5200); define
854 CONFIG_USB_UHCI to enable it.
855 define CONFIG_USB_KEYBOARD to enable the USB Keyboard
856 and define CONFIG_USB_STORAGE to enable the USB
859 Supported are USB Keyboards and USB Floppy drives
861 MPC5200 USB requires additional defines:
863 for 528 MHz Clock: 0x0001bbbb
865 for differential drivers: 0x00001000
866 for single ended drivers: 0x00005000
870 The MMC controller on the Intel PXA is supported. To
871 enable this define CONFIG_MMC. The MMC can be
872 accessed from the boot prompt by mapping the device
873 to physical memory similar to flash. Command line is
874 enabled with CFG_CMD_MMC. The MMC driver also works with
875 the FAT fs. This is enabled with CFG_CMD_FAT.
877 - Journaling Flash filesystem support:
878 CONFIG_JFFS2_NAND, CONFIG_JFFS2_NAND_OFF, CONFIG_JFFS2_NAND_SIZE,
879 CONFIG_JFFS2_NAND_DEV
880 Define these for a default partition on a NAND device
882 CFG_JFFS2_FIRST_SECTOR,
883 CFG_JFFS2_FIRST_BANK, CFG_JFFS2_NUM_BANKS
884 Define these for a default partition on a NOR device
887 Define this to create an own partition. You have to provide a
888 function struct part_info* jffs2_part_info(int part_num)
890 If you define only one JFFS2 partition you may also want to
891 #define CFG_JFFS_SINGLE_PART 1
892 to disable the command chpart. This is the default when you
893 have not defined a custom partition
898 Define this to enable standard (PC-Style) keyboard
902 Standard PC keyboard driver with US (is default) and
903 GERMAN key layout (switch via environment 'keymap=de') support.
904 Export function i8042_kbd_init, i8042_tstc and i8042_getc
905 for cfb_console. Supports cursor blinking.
910 Define this to enable video support (for output to
915 Enable Chips & Technologies 69000 Video chip
917 CONFIG_VIDEO_SMI_LYNXEM
918 Enable Silicon Motion SMI 712/710/810 Video chip. The
919 video output is selected via environment 'videoout'
920 (1 = LCD and 2 = CRT). If videoout is undefined, CRT is
923 For the CT69000 and SMI_LYNXEM drivers, videomode is
924 selected via environment 'videomode'. Two diferent ways
926 - "videomode=num" 'num' is a standard LiLo mode numbers.
927 Following standard modes are supported (* is default):
929 Colors 640x480 800x600 1024x768 1152x864 1280x1024
930 -------------+---------------------------------------------
931 8 bits | 0x301* 0x303 0x305 0x161 0x307
932 15 bits | 0x310 0x313 0x316 0x162 0x319
933 16 bits | 0x311 0x314 0x317 0x163 0x31A
934 24 bits | 0x312 0x315 0x318 ? 0x31B
935 -------------+---------------------------------------------
936 (i.e. setenv videomode 317; saveenv; reset;)
938 - "videomode=bootargs" all the video parameters are parsed
939 from the bootargs. (See drivers/videomodes.c)
942 CONFIG_VIDEO_SED13806
943 Enable Epson SED13806 driver. This driver supports 8bpp
944 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP
945 or CONFIG_VIDEO_SED13806_16BPP
950 Define this to enable a custom keyboard support.
951 This simply calls drv_keyboard_init() which must be
952 defined in your board-specific files.
953 The only board using this so far is RBC823.
955 - LCD Support: CONFIG_LCD
957 Define this to enable LCD support (for output to LCD
958 display); also select one of the supported displays
959 by defining one of these:
961 CONFIG_NEC_NL6448AC33:
963 NEC NL6448AC33-18. Active, color, single scan.
965 CONFIG_NEC_NL6448BC20
967 NEC NL6448BC20-08. 6.5", 640x480.
968 Active, color, single scan.
970 CONFIG_NEC_NL6448BC33_54
972 NEC NL6448BC33-54. 10.4", 640x480.
973 Active, color, single scan.
977 Sharp 320x240. Active, color, single scan.
978 It isn't 16x9, and I am not sure what it is.
980 CONFIG_SHARP_LQ64D341
982 Sharp LQ64D341 display, 640x480.
983 Active, color, single scan.
987 HLD1045 display, 640x480.
988 Active, color, single scan.
992 Optrex CBL50840-2 NF-FW 99 22 M5
994 Hitachi LMG6912RPFC-00T
998 320x240. Black & white.
1000 Normally display is black on white background; define
1001 CFG_WHITE_ON_BLACK to get it inverted.
1003 - Splash Screen Support: CONFIG_SPLASH_SCREEN
1005 If this option is set, the environment is checked for
1006 a variable "splashimage". If found, the usual display
1007 of logo, copyright and system information on the LCD
1008 is suppressed and the BMP image at the address
1009 specified in "splashimage" is loaded instead. The
1010 console is redirected to the "nulldev", too. This
1011 allows for a "silent" boot where a splash screen is
1012 loaded very quickly after power-on.
1014 - Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP
1016 If this option is set, additionally to standard BMP
1017 images, gzipped BMP images can be displayed via the
1018 splashscreen support or the bmp command.
1020 - Compression support:
1023 If this option is set, support for bzip2 compressed
1024 images is included. If not, only uncompressed and gzip
1025 compressed images are supported.
1027 NOTE: the bzip2 algorithm requires a lot of RAM, so
1028 the malloc area (as defined by CFG_MALLOC_LEN) should
1034 The address of PHY on MII bus.
1036 CONFIG_PHY_CLOCK_FREQ (ppc4xx)
1038 The clock frequency of the MII bus
1042 If this option is set, support for speed/duplex
1043 detection of Gigabit PHY is included.
1045 CONFIG_PHY_RESET_DELAY
1047 Some PHY like Intel LXT971A need extra delay after
1048 reset before any MII register access is possible.
1049 For such PHY, set this option to the usec delay
1050 required. (minimum 300usec for LXT971A)
1052 CONFIG_PHY_CMD_DELAY (ppc4xx)
1054 Some PHY like Intel LXT971A need extra delay after
1055 command issued before MII status register can be read
1062 Define a default value for ethernet address to use
1063 for the respective ethernet interface, in case this
1064 is not determined automatically.
1069 Define a default value for the IP address to use for
1070 the default ethernet interface, in case this is not
1071 determined through e.g. bootp.
1073 - Server IP address:
1076 Defines a default value for theIP address of a TFTP
1077 server to contact when using the "tftboot" command.
1079 - BOOTP Recovery Mode:
1080 CONFIG_BOOTP_RANDOM_DELAY
1082 If you have many targets in a network that try to
1083 boot using BOOTP, you may want to avoid that all
1084 systems send out BOOTP requests at precisely the same
1085 moment (which would happen for instance at recovery
1086 from a power failure, when all systems will try to
1087 boot, thus flooding the BOOTP server. Defining
1088 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
1089 inserted before sending out BOOTP requests. The
1090 following delays are insterted then:
1092 1st BOOTP request: delay 0 ... 1 sec
1093 2nd BOOTP request: delay 0 ... 2 sec
1094 3rd BOOTP request: delay 0 ... 4 sec
1096 BOOTP requests: delay 0 ... 8 sec
1098 - DHCP Advanced Options:
1101 You can fine tune the DHCP functionality by adding
1102 these flags to the CONFIG_BOOTP_MASK define:
1104 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS
1105 serverip from a DHCP server, it is possible that more
1106 than one DNS serverip is offered to the client.
1107 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS
1108 serverip will be stored in the additional environment
1109 variable "dnsip2". The first DNS serverip is always
1110 stored in the variable "dnsip", when CONFIG_BOOTP_DNS
1111 is added to the CONFIG_BOOTP_MASK.
1113 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable
1114 to do a dynamic update of a DNS server. To do this, they
1115 need the hostname of the DHCP requester.
1116 If CONFIG_BOOP_SEND_HOSTNAME is added to the
1117 CONFIG_BOOTP_MASK, the content of the "hostname"
1118 environment variable is passed as option 12 to
1122 CONFIG_CDP_DEVICE_ID
1124 The device id used in CDP trigger frames.
1126 CONFIG_CDP_DEVICE_ID_PREFIX
1128 A two character string which is prefixed to the MAC address
1133 A printf format string which contains the ascii name of
1134 the port. Normally is set to "eth%d" which sets
1135 eth0 for the first ethernet, eth1 for the second etc.
1137 CONFIG_CDP_CAPABILITIES
1139 A 32bit integer which indicates the device capabilities;
1140 0x00000010 for a normal host which does not forwards.
1144 An ascii string containing the version of the software.
1148 An ascii string containing the name of the platform.
1152 A 32bit integer sent on the trigger.
1154 CONFIG_CDP_POWER_CONSUMPTION
1156 A 16bit integer containing the power consumption of the
1157 device in .1 of milliwatts.
1159 CONFIG_CDP_APPLIANCE_VLAN_TYPE
1161 A byte containing the id of the VLAN.
1163 - Status LED: CONFIG_STATUS_LED
1165 Several configurations allow to display the current
1166 status using a LED. For instance, the LED will blink
1167 fast while running U-Boot code, stop blinking as
1168 soon as a reply to a BOOTP request was received, and
1169 start blinking slow once the Linux kernel is running
1170 (supported by a status LED driver in the Linux
1171 kernel). Defining CONFIG_STATUS_LED enables this
1174 - CAN Support: CONFIG_CAN_DRIVER
1176 Defining CONFIG_CAN_DRIVER enables CAN driver support
1177 on those systems that support this (optional)
1178 feature, like the TQM8xxL modules.
1180 - I2C Support: CONFIG_HARD_I2C | CONFIG_SOFT_I2C
1182 These enable I2C serial bus commands. Defining either of
1183 (but not both of) CONFIG_HARD_I2C or CONFIG_SOFT_I2C will
1184 include the appropriate I2C driver for the selected cpu.
1186 This will allow you to use i2c commands at the u-boot
1187 command line (as long as you set CFG_CMD_I2C in
1188 CONFIG_COMMANDS) and communicate with i2c based realtime
1189 clock chips. See common/cmd_i2c.c for a description of the
1190 command line interface.
1192 CONFIG_HARD_I2C selects the CPM hardware driver for I2C.
1194 CONFIG_SOFT_I2C configures u-boot to use a software (aka
1195 bit-banging) driver instead of CPM or similar hardware
1198 There are several other quantities that must also be
1199 defined when you define CONFIG_HARD_I2C or CONFIG_SOFT_I2C.
1201 In both cases you will need to define CFG_I2C_SPEED
1202 to be the frequency (in Hz) at which you wish your i2c bus
1203 to run and CFG_I2C_SLAVE to be the address of this node (ie
1204 the cpu's i2c node address).
1206 Now, the u-boot i2c code for the mpc8xx (cpu/mpc8xx/i2c.c)
1207 sets the cpu up as a master node and so its address should
1208 therefore be cleared to 0 (See, eg, MPC823e User's Manual
1209 p.16-473). So, set CFG_I2C_SLAVE to 0.
1211 That's all that's required for CONFIG_HARD_I2C.
1213 If you use the software i2c interface (CONFIG_SOFT_I2C)
1214 then the following macros need to be defined (examples are
1215 from include/configs/lwmon.h):
1219 (Optional). Any commands necessary to enable the I2C
1220 controller or configure ports.
1222 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
1226 (Only for MPC8260 CPU). The I/O port to use (the code
1227 assumes both bits are on the same port). Valid values
1228 are 0..3 for ports A..D.
1232 The code necessary to make the I2C data line active
1233 (driven). If the data line is open collector, this
1236 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
1240 The code necessary to make the I2C data line tri-stated
1241 (inactive). If the data line is open collector, this
1244 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
1248 Code that returns TRUE if the I2C data line is high,
1251 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
1255 If <bit> is TRUE, sets the I2C data line high. If it
1256 is FALSE, it clears it (low).
1258 eg: #define I2C_SDA(bit) \
1259 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
1260 else immr->im_cpm.cp_pbdat &= ~PB_SDA
1264 If <bit> is TRUE, sets the I2C clock line high. If it
1265 is FALSE, it clears it (low).
1267 eg: #define I2C_SCL(bit) \
1268 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
1269 else immr->im_cpm.cp_pbdat &= ~PB_SCL
1273 This delay is invoked four times per clock cycle so this
1274 controls the rate of data transfer. The data rate thus
1275 is 1 / (I2C_DELAY * 4). Often defined to be something
1278 #define I2C_DELAY udelay(2)
1282 When a board is reset during an i2c bus transfer
1283 chips might think that the current transfer is still
1284 in progress. On some boards it is possible to access
1285 the i2c SCLK line directly, either by using the
1286 processor pin as a GPIO or by having a second pin
1287 connected to the bus. If this option is defined a
1288 custom i2c_init_board() routine in boards/xxx/board.c
1289 is run early in the boot sequence.
1291 CONFIG_I2CFAST (PPC405GP|PPC405EP only)
1293 This option enables configuration of bi_iic_fast[] flags
1294 in u-boot bd_info structure based on u-boot environment
1295 variable "i2cfast". (see also i2cfast)
1297 - SPI Support: CONFIG_SPI
1299 Enables SPI driver (so far only tested with
1300 SPI EEPROM, also an instance works with Crystal A/D and
1301 D/As on the SACSng board)
1305 Enables extended (16-bit) SPI EEPROM addressing.
1306 (symmetrical to CONFIG_I2C_X)
1310 Enables a software (bit-bang) SPI driver rather than
1311 using hardware support. This is a general purpose
1312 driver that only requires three general I/O port pins
1313 (two outputs, one input) to function. If this is
1314 defined, the board configuration must define several
1315 SPI configuration items (port pins to use, etc). For
1316 an example, see include/configs/sacsng.h.
1318 - FPGA Support: CONFIG_FPGA_COUNT
1320 Specify the number of FPGA devices to support.
1324 Used to specify the types of FPGA devices. For example,
1325 #define CONFIG_FPGA CFG_XILINX_VIRTEX2
1327 CFG_FPGA_PROG_FEEDBACK
1329 Enable printing of hash marks during FPGA configuration.
1333 Enable checks on FPGA configuration interface busy
1334 status by the configuration function. This option
1335 will require a board or device specific function to
1340 If defined, a function that provides delays in the FPGA
1341 configuration driver.
1343 CFG_FPGA_CHECK_CTRLC
1344 Allow Control-C to interrupt FPGA configuration
1346 CFG_FPGA_CHECK_ERROR
1348 Check for configuration errors during FPGA bitfile
1349 loading. For example, abort during Virtex II
1350 configuration if the INIT_B line goes low (which
1351 indicated a CRC error).
1355 Maximum time to wait for the INIT_B line to deassert
1356 after PROB_B has been deasserted during a Virtex II
1357 FPGA configuration sequence. The default time is 500
1362 Maximum time to wait for BUSY to deassert during
1363 Virtex II FPGA configuration. The default is 5 mS.
1365 CFG_FPGA_WAIT_CONFIG
1367 Time to wait after FPGA configuration. The default is
1370 - Configuration Management:
1373 If defined, this string will be added to the U-Boot
1374 version information (U_BOOT_VERSION)
1376 - Vendor Parameter Protection:
1378 U-Boot considers the values of the environment
1379 variables "serial#" (Board Serial Number) and
1380 "ethaddr" (Ethernet Address) to be parameters that
1381 are set once by the board vendor / manufacturer, and
1382 protects these variables from casual modification by
1383 the user. Once set, these variables are read-only,
1384 and write or delete attempts are rejected. You can
1385 change this behviour:
1387 If CONFIG_ENV_OVERWRITE is #defined in your config
1388 file, the write protection for vendor parameters is
1389 completely disabled. Anybody can change or delete
1392 Alternatively, if you #define _both_ CONFIG_ETHADDR
1393 _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
1394 ethernet address is installed in the environment,
1395 which can be changed exactly ONCE by the user. [The
1396 serial# is unaffected by this, i. e. it remains
1402 Define this variable to enable the reservation of
1403 "protected RAM", i. e. RAM which is not overwritten
1404 by U-Boot. Define CONFIG_PRAM to hold the number of
1405 kB you want to reserve for pRAM. You can overwrite
1406 this default value by defining an environment
1407 variable "pram" to the number of kB you want to
1408 reserve. Note that the board info structure will
1409 still show the full amount of RAM. If pRAM is
1410 reserved, a new environment variable "mem" will
1411 automatically be defined to hold the amount of
1412 remaining RAM in a form that can be passed as boot
1413 argument to Linux, for instance like that:
1415 setenv bootargs ... mem=\${mem}
1418 This way you can tell Linux not to use this memory,
1419 either, which results in a memory region that will
1420 not be affected by reboots.
1422 *WARNING* If your board configuration uses automatic
1423 detection of the RAM size, you must make sure that
1424 this memory test is non-destructive. So far, the
1425 following board configurations are known to be
1428 ETX094, IVMS8, IVML24, SPD8xx, TQM8xxL,
1429 HERMES, IP860, RPXlite, LWMON, LANTEC,
1430 PCU_E, FLAGADM, TQM8260
1435 Define this variable to stop the system in case of a
1436 fatal error, so that you have to reset it manually.
1437 This is probably NOT a good idea for an embedded
1438 system where you want to system to reboot
1439 automatically as fast as possible, but it may be
1440 useful during development since you can try to debug
1441 the conditions that lead to the situation.
1443 CONFIG_NET_RETRY_COUNT
1445 This variable defines the number of retries for
1446 network operations like ARP, RARP, TFTP, or BOOTP
1447 before giving up the operation. If not defined, a
1448 default value of 5 is used.
1450 - Command Interpreter:
1453 Enable auto completion of commands using TAB.
1457 Define this variable to enable the "hush" shell (from
1458 Busybox) as command line interpreter, thus enabling
1459 powerful command line syntax like
1460 if...then...else...fi conditionals or `&&' and '||'
1461 constructs ("shell scripts").
1463 If undefined, you get the old, much simpler behaviour
1464 with a somewhat smaller memory footprint.
1469 This defines the secondary prompt string, which is
1470 printed when the command interpreter needs more input
1471 to complete a command. Usually "> ".
1475 In the current implementation, the local variables
1476 space and global environment variables space are
1477 separated. Local variables are those you define by
1478 simply typing `name=value'. To access a local
1479 variable later on, you have write `$name' or
1480 `${name}'; to execute the contents of a variable
1481 directly type `$name' at the command prompt.
1483 Global environment variables are those you use
1484 setenv/printenv to work with. To run a command stored
1485 in such a variable, you need to use the run command,
1486 and you must not use the '$' sign to access them.
1488 To store commands and special characters in a
1489 variable, please use double quotation marks
1490 surrounding the whole text of the variable, instead
1491 of the backslashes before semicolons and special
1494 - Commandline Editing and History:
1495 CONFIG_CMDLINE_EDITING
1497 Enable editiong and History functions for interactive
1498 commandline input operations
1500 - Default Environment:
1501 CONFIG_EXTRA_ENV_SETTINGS
1503 Define this to contain any number of null terminated
1504 strings (variable = value pairs) that will be part of
1505 the default environment compiled into the boot image.
1507 For example, place something like this in your
1508 board's config file:
1510 #define CONFIG_EXTRA_ENV_SETTINGS \
1514 Warning: This method is based on knowledge about the
1515 internal format how the environment is stored by the
1516 U-Boot code. This is NOT an official, exported
1517 interface! Although it is unlikely that this format
1518 will change soon, there is no guarantee either.
1519 You better know what you are doing here.
1521 Note: overly (ab)use of the default environment is
1522 discouraged. Make sure to check other ways to preset
1523 the environment like the autoscript function or the
1526 - DataFlash Support:
1527 CONFIG_HAS_DATAFLASH
1529 Defining this option enables DataFlash features and
1530 allows to read/write in Dataflash via the standard
1533 - SystemACE Support:
1536 Adding this option adds support for Xilinx SystemACE
1537 chips attached via some sort of local bus. The address
1538 of the chip must alsh be defined in the
1539 CFG_SYSTEMACE_BASE macro. For example:
1541 #define CONFIG_SYSTEMACE
1542 #define CFG_SYSTEMACE_BASE 0xf0000000
1544 When SystemACE support is added, the "ace" device type
1545 becomes available to the fat commands, i.e. fatls.
1547 - TFTP Fixed UDP Port:
1550 If this is defined, the environment variable tftpsrcp
1551 is used to supply the TFTP UDP source port value.
1552 If tftpsrcp isn't defined, the normal pseudo-random port
1553 number generator is used.
1555 Also, the environment variable tftpdstp is used to supply
1556 the TFTP UDP destination port value. If tftpdstp isn't
1557 defined, the normal port 69 is used.
1559 The purpose for tftpsrcp is to allow a TFTP server to
1560 blindly start the TFTP transfer using the pre-configured
1561 target IP address and UDP port. This has the effect of
1562 "punching through" the (Windows XP) firewall, allowing
1563 the remainder of the TFTP transfer to proceed normally.
1564 A better solution is to properly configure the firewall,
1565 but sometimes that is not allowed.
1567 - Show boot progress:
1568 CONFIG_SHOW_BOOT_PROGRESS
1570 Defining this option allows to add some board-
1571 specific code (calling a user-provided function
1572 "show_boot_progress(int)") that enables you to show
1573 the system's boot progress on some display (for
1574 example, some LED's) on your board. At the moment,
1575 the following checkpoints are implemented:
1578 1 common/cmd_bootm.c before attempting to boot an image
1579 -1 common/cmd_bootm.c Image header has bad magic number
1580 2 common/cmd_bootm.c Image header has correct magic number
1581 -2 common/cmd_bootm.c Image header has bad checksum
1582 3 common/cmd_bootm.c Image header has correct checksum
1583 -3 common/cmd_bootm.c Image data has bad checksum
1584 4 common/cmd_bootm.c Image data has correct checksum
1585 -4 common/cmd_bootm.c Image is for unsupported architecture
1586 5 common/cmd_bootm.c Architecture check OK
1587 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi, standalone)
1588 6 common/cmd_bootm.c Image Type check OK
1589 -6 common/cmd_bootm.c gunzip uncompression error
1590 -7 common/cmd_bootm.c Unimplemented compression type
1591 7 common/cmd_bootm.c Uncompression OK
1592 -8 common/cmd_bootm.c Wrong Image Type (not kernel, multi, standalone)
1593 8 common/cmd_bootm.c Image Type check OK
1594 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX)
1595 9 common/cmd_bootm.c Start initial ramdisk verification
1596 -10 common/cmd_bootm.c Ramdisk header has bad magic number
1597 -11 common/cmd_bootm.c Ramdisk header has bad checksum
1598 10 common/cmd_bootm.c Ramdisk header is OK
1599 -12 common/cmd_bootm.c Ramdisk data has bad checksum
1600 11 common/cmd_bootm.c Ramdisk data has correct checksum
1601 12 common/cmd_bootm.c Ramdisk verification complete, start loading
1602 -13 common/cmd_bootm.c Wrong Image Type (not PPC Linux Ramdisk)
1603 13 common/cmd_bootm.c Start multifile image verification
1604 14 common/cmd_bootm.c No initial ramdisk, no multifile, continue.
1605 15 common/cmd_bootm.c All preparation done, transferring control to OS
1607 -30 lib_ppc/board.c Fatal error, hang the system
1608 -31 post/post.c POST test failed, detected by post_output_backlog()
1609 -32 post/post.c POST test failed, detected by post_run_single()
1611 -1 common/cmd_doc.c Bad usage of "doc" command
1612 -1 common/cmd_doc.c No boot device
1613 -1 common/cmd_doc.c Unknown Chip ID on boot device
1614 -1 common/cmd_doc.c Read Error on boot device
1615 -1 common/cmd_doc.c Image header has bad magic number
1617 -1 common/cmd_ide.c Bad usage of "ide" command
1618 -1 common/cmd_ide.c No boot device
1619 -1 common/cmd_ide.c Unknown boot device
1620 -1 common/cmd_ide.c Unknown partition table
1621 -1 common/cmd_ide.c Invalid partition type
1622 -1 common/cmd_ide.c Read Error on boot device
1623 -1 common/cmd_ide.c Image header has bad magic number
1625 -1 common/cmd_nand.c Bad usage of "nand" command
1626 -1 common/cmd_nand.c No boot device
1627 -1 common/cmd_nand.c Unknown Chip ID on boot device
1628 -1 common/cmd_nand.c Read Error on boot device
1629 -1 common/cmd_nand.c Image header has bad magic number
1631 -1 common/env_common.c Environment has a bad CRC, using default
1637 [so far only for SMDK2400 and TRAB boards]
1639 - Modem support endable:
1640 CONFIG_MODEM_SUPPORT
1642 - RTS/CTS Flow control enable:
1645 - Modem debug support:
1646 CONFIG_MODEM_SUPPORT_DEBUG
1648 Enables debugging stuff (char screen[1024], dbg())
1649 for modem support. Useful only with BDI2000.
1651 - Interrupt support (PPC):
1653 There are common interrupt_init() and timer_interrupt()
1654 for all PPC archs. interrupt_init() calls interrupt_init_cpu()
1655 for cpu specific initialization. interrupt_init_cpu()
1656 should set decrementer_count to appropriate value. If
1657 cpu resets decrementer automatically after interrupt
1658 (ppc4xx) it should set decrementer_count to zero.
1659 timer_interrupt() calls timer_interrupt_cpu() for cpu
1660 specific handling. If board has watchdog / status_led
1661 / other_activity_monitor it works automatically from
1662 general timer_interrupt().
1666 In the target system modem support is enabled when a
1667 specific key (key combination) is pressed during
1668 power-on. Otherwise U-Boot will boot normally
1669 (autoboot). The key_pressed() fuction is called from
1670 board_init(). Currently key_pressed() is a dummy
1671 function, returning 1 and thus enabling modem
1674 If there are no modem init strings in the
1675 environment, U-Boot proceed to autoboot; the
1676 previous output (banner, info printfs) will be
1679 See also: doc/README.Modem
1682 Configuration Settings:
1683 -----------------------
1685 - CFG_LONGHELP: Defined when you want long help messages included;
1686 undefine this when you're short of memory.
1688 - CFG_PROMPT: This is what U-Boot prints on the console to
1689 prompt for user input.
1691 - CFG_CBSIZE: Buffer size for input from the Console
1693 - CFG_PBSIZE: Buffer size for Console output
1695 - CFG_MAXARGS: max. Number of arguments accepted for monitor commands
1697 - CFG_BARGSIZE: Buffer size for Boot Arguments which are passed to
1698 the application (usually a Linux kernel) when it is
1701 - CFG_BAUDRATE_TABLE:
1702 List of legal baudrate settings for this board.
1704 - CFG_CONSOLE_INFO_QUIET
1705 Suppress display of console information at boot.
1707 - CFG_CONSOLE_IS_IN_ENV
1708 If the board specific function
1709 extern int overwrite_console (void);
1710 returns 1, the stdin, stderr and stdout are switched to the
1711 serial port, else the settings in the environment are used.
1713 - CFG_CONSOLE_OVERWRITE_ROUTINE
1714 Enable the call to overwrite_console().
1716 - CFG_CONSOLE_ENV_OVERWRITE
1717 Enable overwrite of previous console environment settings.
1719 - CFG_MEMTEST_START, CFG_MEMTEST_END:
1720 Begin and End addresses of the area used by the
1724 Enable an alternate, more extensive memory test.
1726 - CFG_MEMTEST_SCRATCH:
1727 Scratch address used by the alternate memory test
1728 You only need to set this if address zero isn't writeable
1730 - CFG_TFTP_LOADADDR:
1731 Default load address for network file downloads
1733 - CFG_LOADS_BAUD_CHANGE:
1734 Enable temporary baudrate change while serial download
1737 Physical start address of SDRAM. _Must_ be 0 here.
1740 Physical start address of Motherboard I/O (if using a
1744 Physical start address of Flash memory.
1747 Physical start address of boot monitor code (set by
1748 make config files to be same as the text base address
1749 (TEXT_BASE) used when linking) - same as
1750 CFG_FLASH_BASE when booting from flash.
1753 Size of memory reserved for monitor code, used to
1754 determine _at_compile_time_ (!) if the environment is
1755 embedded within the U-Boot image, or in a separate
1759 Size of DRAM reserved for malloc() use.
1762 Normally compressed uImages are limited to an
1763 uncompressed size of 8 MBytes. If this is not enough,
1764 you can define CFG_BOOTM_LEN in your board config file
1765 to adjust this setting to your needs.
1768 Maximum size of memory mapped by the startup code of
1769 the Linux kernel; all data that must be processed by
1770 the Linux kernel (bd_info, boot arguments, eventually
1771 initrd image) must be put below this limit.
1773 - CFG_MAX_FLASH_BANKS:
1774 Max number of Flash memory banks
1776 - CFG_MAX_FLASH_SECT:
1777 Max number of sectors on a Flash chip
1779 - CFG_FLASH_ERASE_TOUT:
1780 Timeout for Flash erase operations (in ms)
1782 - CFG_FLASH_WRITE_TOUT:
1783 Timeout for Flash write operations (in ms)
1785 - CFG_FLASH_LOCK_TOUT
1786 Timeout for Flash set sector lock bit operation (in ms)
1788 - CFG_FLASH_UNLOCK_TOUT
1789 Timeout for Flash clear lock bits operation (in ms)
1791 - CFG_FLASH_PROTECTION
1792 If defined, hardware flash sectors protection is used
1793 instead of U-Boot software protection.
1795 - CFG_DIRECT_FLASH_TFTP:
1797 Enable TFTP transfers directly to flash memory;
1798 without this option such a download has to be
1799 performed in two steps: (1) download to RAM, and (2)
1800 copy from RAM to flash.
1802 The two-step approach is usually more reliable, since
1803 you can check if the download worked before you erase
1804 the flash, but in some situations (when sytem RAM is
1805 too limited to allow for a tempory copy of the
1806 downloaded image) this option may be very useful.
1809 Define if the flash driver uses extra elements in the
1810 common flash structure for storing flash geometry.
1812 - CFG_FLASH_CFI_DRIVER
1813 This option also enables the building of the cfi_flash driver
1814 in the drivers directory
1816 - CFG_FLASH_QUIET_TEST
1817 If this option is defined, the common CFI flash doesn't
1818 print it's warning upon not recognized FLASH banks. This
1819 is useful, if some of the configured banks are only
1820 optionally available.
1822 - CFG_RX_ETH_BUFFER:
1823 Defines the number of ethernet receive buffers. On some
1824 ethernet controllers it is recommended to set this value
1825 to 8 or even higher (EEPRO100 or 405 EMAC), since all
1826 buffers can be full shortly after enabling the interface
1827 on high ethernet traffic.
1828 Defaults to 4 if not defined.
1830 The following definitions that deal with the placement and management
1831 of environment data (variable area); in general, we support the
1832 following configurations:
1834 - CFG_ENV_IS_IN_FLASH:
1836 Define this if the environment is in flash memory.
1838 a) The environment occupies one whole flash sector, which is
1839 "embedded" in the text segment with the U-Boot code. This
1840 happens usually with "bottom boot sector" or "top boot
1841 sector" type flash chips, which have several smaller
1842 sectors at the start or the end. For instance, such a
1843 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In
1844 such a case you would place the environment in one of the
1845 4 kB sectors - with U-Boot code before and after it. With
1846 "top boot sector" type flash chips, you would put the
1847 environment in one of the last sectors, leaving a gap
1848 between U-Boot and the environment.
1852 Offset of environment data (variable area) to the
1853 beginning of flash memory; for instance, with bottom boot
1854 type flash chips the second sector can be used: the offset
1855 for this sector is given here.
1857 CFG_ENV_OFFSET is used relative to CFG_FLASH_BASE.
1861 This is just another way to specify the start address of
1862 the flash sector containing the environment (instead of
1865 - CFG_ENV_SECT_SIZE:
1867 Size of the sector containing the environment.
1870 b) Sometimes flash chips have few, equal sized, BIG sectors.
1871 In such a case you don't want to spend a whole sector for
1876 If you use this in combination with CFG_ENV_IS_IN_FLASH
1877 and CFG_ENV_SECT_SIZE, you can specify to use only a part
1878 of this flash sector for the environment. This saves
1879 memory for the RAM copy of the environment.
1881 It may also save flash memory if you decide to use this
1882 when your environment is "embedded" within U-Boot code,
1883 since then the remainder of the flash sector could be used
1884 for U-Boot code. It should be pointed out that this is
1885 STRONGLY DISCOURAGED from a robustness point of view:
1886 updating the environment in flash makes it always
1887 necessary to erase the WHOLE sector. If something goes
1888 wrong before the contents has been restored from a copy in
1889 RAM, your target system will be dead.
1891 - CFG_ENV_ADDR_REDUND
1894 These settings describe a second storage area used to hold
1895 a redundand copy of the environment data, so that there is
1896 a valid backup copy in case there is a power failure during
1897 a "saveenv" operation.
1899 BE CAREFUL! Any changes to the flash layout, and some changes to the
1900 source code will make it necessary to adapt <board>/u-boot.lds*
1904 - CFG_ENV_IS_IN_NVRAM:
1906 Define this if you have some non-volatile memory device
1907 (NVRAM, battery buffered SRAM) which you want to use for the
1913 These two #defines are used to determin the memory area you
1914 want to use for environment. It is assumed that this memory
1915 can just be read and written to, without any special
1918 BE CAREFUL! The first access to the environment happens quite early
1919 in U-Boot initalization (when we try to get the setting of for the
1920 console baudrate). You *MUST* have mappend your NVRAM area then, or
1923 Please note that even with NVRAM we still use a copy of the
1924 environment in RAM: we could work on NVRAM directly, but we want to
1925 keep settings there always unmodified except somebody uses "saveenv"
1926 to save the current settings.
1929 - CFG_ENV_IS_IN_EEPROM:
1931 Use this if you have an EEPROM or similar serial access
1932 device and a driver for it.
1937 These two #defines specify the offset and size of the
1938 environment area within the total memory of your EEPROM.
1940 - CFG_I2C_EEPROM_ADDR:
1941 If defined, specified the chip address of the EEPROM device.
1942 The default address is zero.
1944 - CFG_EEPROM_PAGE_WRITE_BITS:
1945 If defined, the number of bits used to address bytes in a
1946 single page in the EEPROM device. A 64 byte page, for example
1947 would require six bits.
1949 - CFG_EEPROM_PAGE_WRITE_DELAY_MS:
1950 If defined, the number of milliseconds to delay between
1951 page writes. The default is zero milliseconds.
1953 - CFG_I2C_EEPROM_ADDR_LEN:
1954 The length in bytes of the EEPROM memory array address. Note
1955 that this is NOT the chip address length!
1957 - CFG_I2C_EEPROM_ADDR_OVERFLOW:
1958 EEPROM chips that implement "address overflow" are ones
1959 like Catalyst 24WC04/08/16 which has 9/10/11 bits of
1960 address and the extra bits end up in the "chip address" bit
1961 slots. This makes a 24WC08 (1Kbyte) chip look like four 256
1964 Note that we consider the length of the address field to
1965 still be one byte because the extra address bits are hidden
1966 in the chip address.
1969 The size in bytes of the EEPROM device.
1972 - CFG_ENV_IS_IN_DATAFLASH:
1974 Define this if you have a DataFlash memory device which you
1975 want to use for the environment.
1981 These three #defines specify the offset and size of the
1982 environment area within the total memory of your DataFlash placed
1983 at the specified address.
1985 - CFG_ENV_IS_IN_NAND:
1987 Define this if you have a NAND device which you want to use
1988 for the environment.
1993 These two #defines specify the offset and size of the environment
1994 area within the first NAND device.
1996 - CFG_ENV_OFFSET_REDUND
1998 This setting describes a second storage area of CFG_ENV_SIZE
1999 size used to hold a redundant copy of the environment data,
2000 so that there is a valid backup copy in case there is a
2001 power failure during a "saveenv" operation.
2003 Note: CFG_ENV_OFFSET and CFG_ENV_OFFSET_REDUND must be aligned
2004 to a block boundary, and CFG_ENV_SIZE must be a multiple of
2005 the NAND devices block size.
2007 - CFG_SPI_INIT_OFFSET
2009 Defines offset to the initial SPI buffer area in DPRAM. The
2010 area is used at an early stage (ROM part) if the environment
2011 is configured to reside in the SPI EEPROM: We need a 520 byte
2012 scratch DPRAM area. It is used between the two initialization
2013 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems
2014 to be a good choice since it makes it far enough from the
2015 start of the data area as well as from the stack pointer.
2017 Please note that the environment is read-only as long as the monitor
2018 has been relocated to RAM and a RAM copy of the environment has been
2019 created; also, when using EEPROM you will have to use getenv_r()
2020 until then to read environment variables.
2022 The environment is protected by a CRC32 checksum. Before the monitor
2023 is relocated into RAM, as a result of a bad CRC you will be working
2024 with the compiled-in default environment - *silently*!!! [This is
2025 necessary, because the first environment variable we need is the
2026 "baudrate" setting for the console - if we have a bad CRC, we don't
2027 have any device yet where we could complain.]
2029 Note: once the monitor has been relocated, then it will complain if
2030 the default environment is used; a new CRC is computed as soon as you
2031 use the "saveenv" command to store a valid environment.
2033 - CFG_FAULT_ECHO_LINK_DOWN:
2034 Echo the inverted Ethernet link state to the fault LED.
2036 Note: If this option is active, then CFG_FAULT_MII_ADDR
2037 also needs to be defined.
2039 - CFG_FAULT_MII_ADDR:
2040 MII address of the PHY to check for the Ethernet link state.
2042 - CFG_64BIT_VSPRINTF:
2043 Makes vsprintf (and all *printf functions) support printing
2044 of 64bit values by using the L quantifier
2046 - CFG_64BIT_STRTOUL:
2047 Adds simple_strtoull that returns a 64bit value
2049 Low Level (hardware related) configuration options:
2050 ---------------------------------------------------
2052 - CFG_CACHELINE_SIZE:
2053 Cache Line Size of the CPU.
2056 Default address of the IMMR after system reset.
2058 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU,
2059 and RPXsuper) to be able to adjust the position of
2060 the IMMR register after a reset.
2062 - Floppy Disk Support:
2063 CFG_FDC_DRIVE_NUMBER
2065 the default drive number (default value 0)
2069 defines the spacing between fdc chipset registers
2074 defines the offset of register from address. It
2075 depends on which part of the data bus is connected to
2076 the fdc chipset. (default value 0)
2078 If CFG_ISA_IO_STRIDE CFG_ISA_IO_OFFSET and
2079 CFG_FDC_DRIVE_NUMBER are undefined, they take their
2082 if CFG_FDC_HW_INIT is defined, then the function
2083 fdc_hw_init() is called at the beginning of the FDC
2084 setup. fdc_hw_init() must be provided by the board
2085 source code. It is used to make hardware dependant
2088 - CFG_IMMR: Physical address of the Internal Memory.
2089 DO NOT CHANGE unless you know exactly what you're
2090 doing! (11-4) [MPC8xx/82xx systems only]
2092 - CFG_INIT_RAM_ADDR:
2094 Start address of memory area that can be used for
2095 initial data and stack; please note that this must be
2096 writable memory that is working WITHOUT special
2097 initialization, i. e. you CANNOT use normal RAM which
2098 will become available only after programming the
2099 memory controller and running certain initialization
2102 U-Boot uses the following memory types:
2103 - MPC8xx and MPC8260: IMMR (internal memory of the CPU)
2104 - MPC824X: data cache
2105 - PPC4xx: data cache
2107 - CFG_GBL_DATA_OFFSET:
2109 Offset of the initial data structure in the memory
2110 area defined by CFG_INIT_RAM_ADDR. Usually
2111 CFG_GBL_DATA_OFFSET is chosen such that the initial
2112 data is located at the end of the available space
2113 (sometimes written as (CFG_INIT_RAM_END -
2114 CFG_INIT_DATA_SIZE), and the initial stack is just
2115 below that area (growing from (CFG_INIT_RAM_ADDR +
2116 CFG_GBL_DATA_OFFSET) downward.
2119 On the MPC824X (or other systems that use the data
2120 cache for initial memory) the address chosen for
2121 CFG_INIT_RAM_ADDR is basically arbitrary - it must
2122 point to an otherwise UNUSED address space between
2123 the top of RAM and the start of the PCI space.
2125 - CFG_SIUMCR: SIU Module Configuration (11-6)
2127 - CFG_SYPCR: System Protection Control (11-9)
2129 - CFG_TBSCR: Time Base Status and Control (11-26)
2131 - CFG_PISCR: Periodic Interrupt Status and Control (11-31)
2133 - CFG_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30)
2135 - CFG_SCCR: System Clock and reset Control Register (15-27)
2137 - CFG_OR_TIMING_SDRAM:
2141 periodic timer for refresh
2143 - CFG_DER: Debug Event Register (37-47)
2145 - FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CFG_REMAP_OR_AM,
2146 CFG_PRELIM_OR_AM, CFG_OR_TIMING_FLASH, CFG_OR0_REMAP,
2147 CFG_OR0_PRELIM, CFG_BR0_PRELIM, CFG_OR1_REMAP, CFG_OR1_PRELIM,
2149 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
2151 - SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
2152 CFG_OR_TIMING_SDRAM, CFG_OR2_PRELIM, CFG_BR2_PRELIM,
2153 CFG_OR3_PRELIM, CFG_BR3_PRELIM:
2154 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
2156 - CFG_MAMR_PTA, CFG_MPTPR_2BK_4K, CFG_MPTPR_1BK_4K, CFG_MPTPR_2BK_8K,
2157 CFG_MPTPR_1BK_8K, CFG_MAMR_8COL, CFG_MAMR_9COL:
2158 Machine Mode Register and Memory Periodic Timer
2159 Prescaler definitions (SDRAM timing)
2161 - CFG_I2C_UCODE_PATCH, CFG_I2C_DPMEM_OFFSET [0x1FC0]:
2162 enable I2C microcode relocation patch (MPC8xx);
2163 define relocation offset in DPRAM [DSP2]
2165 - CFG_SPI_UCODE_PATCH, CFG_SPI_DPMEM_OFFSET [0x1FC0]:
2166 enable SPI microcode relocation patch (MPC8xx);
2167 define relocation offset in DPRAM [SCC4]
2170 Use OSCM clock mode on MBX8xx board. Be careful,
2171 wrong setting might damage your board. Read
2172 doc/README.MBX before setting this variable!
2174 - CFG_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only)
2175 Offset of the bootmode word in DPRAM used by post
2176 (Power On Self Tests). This definition overrides
2177 #define'd default value in commproc.h resp.
2180 - CFG_PCI_SLV_MEM_LOCAL, CFG_PCI_SLV_MEM_BUS, CFG_PICMR0_MASK_ATTRIB,
2181 CFG_PCI_MSTR0_LOCAL, CFG_PCIMSK0_MASK, CFG_PCI_MSTR1_LOCAL,
2182 CFG_PCIMSK1_MASK, CFG_PCI_MSTR_MEM_LOCAL, CFG_PCI_MSTR_MEM_BUS,
2183 CFG_CPU_PCI_MEM_START, CFG_PCI_MSTR_MEM_SIZE, CFG_POCMR0_MASK_ATTRIB,
2184 CFG_PCI_MSTR_MEMIO_LOCAL, CFG_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START,
2185 CFG_PCI_MSTR_MEMIO_SIZE, CFG_POCMR1_MASK_ATTRIB, CFG_PCI_MSTR_IO_LOCAL,
2186 CFG_PCI_MSTR_IO_BUS, CFG_CPU_PCI_IO_START, CFG_PCI_MSTR_IO_SIZE,
2187 CFG_POCMR2_MASK_ATTRIB: (MPC826x only)
2188 Overrides the default PCI memory map in cpu/mpc8260/pci.c if set.
2190 - CONFIG_ETHER_ON_FEC[12]
2191 Define to enable FEC[12] on a 8xx series processor.
2193 - CONFIG_FEC[12]_PHY
2194 Define to the hardcoded PHY address which corresponds
2195 to the given FEC; i. e.
2196 #define CONFIG_FEC1_PHY 4
2197 means that the PHY with address 4 is connected to FEC1
2199 When set to -1, means to probe for first available.
2201 - CONFIG_FEC[12]_PHY_NORXERR
2202 The PHY does not have a RXERR line (RMII only).
2203 (so program the FEC to ignore it).
2206 Enable RMII mode for all FECs.
2207 Note that this is a global option, we can't
2208 have one FEC in standard MII mode and another in RMII mode.
2210 - CONFIG_CRC32_VERIFY
2211 Add a verify option to the crc32 command.
2214 => crc32 -v <address> <count> <crc32>
2216 Where address/count indicate a memory area
2217 and crc32 is the correct crc32 which the
2221 Add the "loopw" memory command. This only takes effect if
2222 the memory commands are activated globally (CFG_CMD_MEM).
2225 Add the "mdc" and "mwc" memory commands. These are cyclic
2230 This command will print 4 bytes (10,11,12,13) each 500 ms.
2232 => mwc.l 100 12345678 10
2233 This command will write 12345678 to address 100 all 10 ms.
2235 This only takes effect if the memory commands are activated
2236 globally (CFG_CMD_MEM).
2238 - CONFIG_SKIP_LOWLEVEL_INIT
2239 - CONFIG_SKIP_RELOCATE_UBOOT
2241 [ARM only] If these variables are defined, then
2242 certain low level initializations (like setting up
2243 the memory controller) are omitted and/or U-Boot does
2244 not relocate itself into RAM.
2245 Normally these variables MUST NOT be defined. The
2246 only exception is when U-Boot is loaded (to RAM) by
2247 some other boot loader or by a debugger which
2248 performs these intializations itself.
2251 Building the Software:
2252 ======================
2254 Building U-Boot has been tested in native PPC environments (on a
2255 PowerBook G3 running LinuxPPC 2000) and in cross environments
2256 (running RedHat 6.x and 7.x Linux on x86, Solaris 2.6 on a SPARC, and
2259 If you are not using a native PPC environment, it is assumed that you
2260 have the GNU cross compiling tools available in your path and named
2261 with a prefix of "powerpc-linux-". If this is not the case, (e.g. if
2262 you are using Monta Vista's Hard Hat Linux CDK 1.2) you must change
2263 the definition of CROSS_COMPILE in Makefile. For HHL on a 4xx CPU,
2266 CROSS_COMPILE = ppc_4xx-
2269 U-Boot is intended to be simple to build. After installing the
2270 sources you must configure U-Boot for one specific board type. This
2275 where "NAME_config" is the name of one of the existing
2276 configurations; the following names are supported:
2278 ADCIOP_config FPS860L_config omap730p2_config
2279 ADS860_config GEN860T_config pcu_e_config
2281 AR405_config GENIETV_config PIP405_config
2282 at91rm9200dk_config GTH_config QS823_config
2283 CANBT_config hermes_config QS850_config
2284 cmi_mpc5xx_config hymod_config QS860T_config
2285 cogent_common_config IP860_config RPXlite_config
2286 cogent_mpc8260_config IVML24_config RPXlite_DW_config
2287 cogent_mpc8xx_config IVMS8_config RPXsuper_config
2288 CPCI405_config JSE_config rsdproto_config
2289 CPCIISER4_config LANTEC_config Sandpoint8240_config
2290 csb272_config lwmon_config sbc8260_config
2291 CU824_config MBX860T_config sbc8560_33_config
2292 DUET_ADS_config MBX_config sbc8560_66_config
2293 EBONY_config MPC8260ADS_config SM850_config
2294 ELPT860_config MPC8540ADS_config SPD823TS_config
2295 ESTEEM192E_config MPC8540EVAL_config stxgp3_config
2296 ETX094_config MPC8560ADS_config SXNI855T_config
2297 FADS823_config NETVIA_config TQM823L_config
2298 FADS850SAR_config omap1510inn_config TQM850L_config
2299 FADS860T_config omap1610h2_config TQM855L_config
2300 FPS850L_config omap1610inn_config TQM860L_config
2301 omap5912osk_config walnut_config
2302 omap2420h4_config Yukon8220_config
2305 Note: for some board special configuration names may exist; check if
2306 additional information is available from the board vendor; for
2307 instance, the TQM823L systems are available without (standard)
2308 or with LCD support. You can select such additional "features"
2309 when chosing the configuration, i. e.
2312 - will configure for a plain TQM823L, i. e. no LCD support
2314 make TQM823L_LCD_config
2315 - will configure for a TQM823L with U-Boot console on LCD
2320 Finally, type "make all", and you should get some working U-Boot
2321 images ready for download to / installation on your system:
2323 - "u-boot.bin" is a raw binary image
2324 - "u-boot" is an image in ELF binary format
2325 - "u-boot.srec" is in Motorola S-Record format
2327 By default the build is performed locally and the objects are saved
2328 in the source directory. One of the two methods can be used to change
2329 this behavior and build U-Boot to some external directory:
2331 1. Add O= to the make command line invocations:
2333 make O=/tmp/build distclean
2334 make O=/tmp/build NAME_config
2335 make O=/tmp/build all
2337 2. Set environment variable BUILD_DIR to point to the desired location:
2339 export BUILD_DIR=/tmp/build
2344 Note that the command line "O=" setting overrides the BUILD_DIR environment
2348 Please be aware that the Makefiles assume you are using GNU make, so
2349 for instance on NetBSD you might need to use "gmake" instead of
2353 If the system board that you have is not listed, then you will need
2354 to port U-Boot to your hardware platform. To do this, follow these
2357 1. Add a new configuration option for your board to the toplevel
2358 "Makefile" and to the "MAKEALL" script, using the existing
2359 entries as examples. Note that here and at many other places
2360 boards and other names are listed in alphabetical sort order. Please
2362 2. Create a new directory to hold your board specific code. Add any
2363 files you need. In your board directory, you will need at least
2364 the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds".
2365 3. Create a new configuration file "include/configs/<board>.h" for
2367 3. If you're porting U-Boot to a new CPU, then also create a new
2368 directory to hold your CPU specific code. Add any files you need.
2369 4. Run "make <board>_config" with your new name.
2370 5. Type "make", and you should get a working "u-boot.srec" file
2371 to be installed on your target system.
2372 6. Debug and solve any problems that might arise.
2373 [Of course, this last step is much harder than it sounds.]
2376 Testing of U-Boot Modifications, Ports to New Hardware, etc.:
2377 ==============================================================
2379 If you have modified U-Boot sources (for instance added a new board
2380 or support for new devices, a new CPU, etc.) you are expected to
2381 provide feedback to the other developers. The feedback normally takes
2382 the form of a "patch", i. e. a context diff against a certain (latest
2383 official or latest in CVS) version of U-Boot sources.
2385 But before you submit such a patch, please verify that your modifi-
2386 cation did not break existing code. At least make sure that *ALL* of
2387 the supported boards compile WITHOUT ANY compiler warnings. To do so,
2388 just run the "MAKEALL" script, which will configure and build U-Boot
2389 for ALL supported system. Be warned, this will take a while. You can
2390 select which (cross) compiler to use by passing a `CROSS_COMPILE'
2391 environment variable to the script, i. e. to use the cross tools from
2392 MontaVista's Hard Hat Linux you can type
2394 CROSS_COMPILE=ppc_8xx- MAKEALL
2396 or to build on a native PowerPC system you can type
2398 CROSS_COMPILE=' ' MAKEALL
2400 When using the MAKEALL script, the default behaviour is to build U-Boot
2401 in the source directory. This location can be changed by setting the
2402 BUILD_DIR environment variable. Also, for each target built, the MAKEALL
2403 script saves two log files (<target>.ERR and <target>.MAKEALL) in the
2404 <source dir>/LOG directory. This default location can be changed by
2405 setting the MAKEALL_LOGDIR environment variable. For example:
2407 export BUILD_DIR=/tmp/build
2408 export MAKEALL_LOGDIR=/tmp/log
2409 CROSS_COMPILE=ppc_8xx- MAKEALL
2411 With the above settings build objects are saved in the /tmp/build, log
2412 files are saved in the /tmp/log and the source tree remains clean during
2413 the whole build process.
2416 See also "U-Boot Porting Guide" below.
2419 Monitor Commands - Overview:
2420 ============================
2422 go - start application at address 'addr'
2423 run - run commands in an environment variable
2424 bootm - boot application image from memory
2425 bootp - boot image via network using BootP/TFTP protocol
2426 tftpboot- boot image via network using TFTP protocol
2427 and env variables "ipaddr" and "serverip"
2428 (and eventually "gatewayip")
2429 rarpboot- boot image via network using RARP/TFTP protocol
2430 diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
2431 loads - load S-Record file over serial line
2432 loadb - load binary file over serial line (kermit mode)
2434 mm - memory modify (auto-incrementing)
2435 nm - memory modify (constant address)
2436 mw - memory write (fill)
2438 cmp - memory compare
2439 crc32 - checksum calculation
2440 imd - i2c memory display
2441 imm - i2c memory modify (auto-incrementing)
2442 inm - i2c memory modify (constant address)
2443 imw - i2c memory write (fill)
2444 icrc32 - i2c checksum calculation
2445 iprobe - probe to discover valid I2C chip addresses
2446 iloop - infinite loop on address range
2447 isdram - print SDRAM configuration information
2448 sspi - SPI utility commands
2449 base - print or set address offset
2450 printenv- print environment variables
2451 setenv - set environment variables
2452 saveenv - save environment variables to persistent storage
2453 protect - enable or disable FLASH write protection
2454 erase - erase FLASH memory
2455 flinfo - print FLASH memory information
2456 bdinfo - print Board Info structure
2457 iminfo - print header information for application image
2458 coninfo - print console devices and informations
2459 ide - IDE sub-system
2460 loop - infinite loop on address range
2461 loopw - infinite write loop on address range
2462 mtest - simple RAM test
2463 icache - enable or disable instruction cache
2464 dcache - enable or disable data cache
2465 reset - Perform RESET of the CPU
2466 echo - echo args to console
2467 version - print monitor version
2468 help - print online help
2469 ? - alias for 'help'
2472 Monitor Commands - Detailed Description:
2473 ========================================
2477 For now: just type "help <command>".
2480 Environment Variables:
2481 ======================
2483 U-Boot supports user configuration using Environment Variables which
2484 can be made persistent by saving to Flash memory.
2486 Environment Variables are set using "setenv", printed using
2487 "printenv", and saved to Flash using "saveenv". Using "setenv"
2488 without a value can be used to delete a variable from the
2489 environment. As long as you don't save the environment you are
2490 working with an in-memory copy. In case the Flash area containing the
2491 environment is erased by accident, a default environment is provided.
2493 Some configuration options can be set using Environment Variables:
2495 baudrate - see CONFIG_BAUDRATE
2497 bootdelay - see CONFIG_BOOTDELAY
2499 bootcmd - see CONFIG_BOOTCOMMAND
2501 bootargs - Boot arguments when booting an RTOS image
2503 bootfile - Name of the image to load with TFTP
2505 autoload - if set to "no" (any string beginning with 'n'),
2506 "bootp" will just load perform a lookup of the
2507 configuration from the BOOTP server, but not try to
2508 load any image using TFTP
2510 autostart - if set to "yes", an image loaded using the "bootp",
2511 "rarpboot", "tftpboot" or "diskboot" commands will
2512 be automatically started (by internally calling
2515 If set to "no", a standalone image passed to the
2516 "bootm" command will be copied to the load address
2517 (and eventually uncompressed), but NOT be started.
2518 This can be used to load and uncompress arbitrary
2521 i2cfast - (PPC405GP|PPC405EP only)
2522 if set to 'y' configures Linux I2C driver for fast
2523 mode (400kHZ). This environment variable is used in
2524 initialization code. So, for changes to be effective
2525 it must be saved and board must be reset.
2527 initrd_high - restrict positioning of initrd images:
2528 If this variable is not set, initrd images will be
2529 copied to the highest possible address in RAM; this
2530 is usually what you want since it allows for
2531 maximum initrd size. If for some reason you want to
2532 make sure that the initrd image is loaded below the
2533 CFG_BOOTMAPSZ limit, you can set this environment
2534 variable to a value of "no" or "off" or "0".
2535 Alternatively, you can set it to a maximum upper
2536 address to use (U-Boot will still check that it
2537 does not overwrite the U-Boot stack and data).
2539 For instance, when you have a system with 16 MB
2540 RAM, and want to reserve 4 MB from use by Linux,
2541 you can do this by adding "mem=12M" to the value of
2542 the "bootargs" variable. However, now you must make
2543 sure that the initrd image is placed in the first
2544 12 MB as well - this can be done with
2546 setenv initrd_high 00c00000
2548 If you set initrd_high to 0xFFFFFFFF, this is an
2549 indication to U-Boot that all addresses are legal
2550 for the Linux kernel, including addresses in flash
2551 memory. In this case U-Boot will NOT COPY the
2552 ramdisk at all. This may be useful to reduce the
2553 boot time on your system, but requires that this
2554 feature is supported by your Linux kernel.
2556 ipaddr - IP address; needed for tftpboot command
2558 loadaddr - Default load address for commands like "bootp",
2559 "rarpboot", "tftpboot", "loadb" or "diskboot"
2561 loads_echo - see CONFIG_LOADS_ECHO
2563 serverip - TFTP server IP address; needed for tftpboot command
2565 bootretry - see CONFIG_BOOT_RETRY_TIME
2567 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
2569 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
2571 ethprime - When CONFIG_NET_MULTI is enabled controls which
2572 interface is used first.
2574 ethact - When CONFIG_NET_MULTI is enabled controls which
2575 interface is currently active. For example you
2576 can do the following
2578 => setenv ethact FEC ETHERNET
2579 => ping 192.168.0.1 # traffic sent on FEC ETHERNET
2580 => setenv ethact SCC ETHERNET
2581 => ping 10.0.0.1 # traffic sent on SCC ETHERNET
2583 netretry - When set to "no" each network operation will
2584 either succeed or fail without retrying.
2585 When set to "once" the network operation will
2586 fail when all the available network interfaces
2587 are tried once without success.
2588 Useful on scripts which control the retry operation
2591 tftpsrcport - If this is set, the value is used for TFTP's
2594 tftpdstport - If this is set, the value is used for TFTP's UDP
2595 destination port instead of the Well Know Port 69.
2597 vlan - When set to a value < 4095 the traffic over
2598 ethernet is encapsulated/received over 802.1q
2601 The following environment variables may be used and automatically
2602 updated by the network boot commands ("bootp" and "rarpboot"),
2603 depending the information provided by your boot server:
2605 bootfile - see above
2606 dnsip - IP address of your Domain Name Server
2607 dnsip2 - IP address of your secondary Domain Name Server
2608 gatewayip - IP address of the Gateway (Router) to use
2609 hostname - Target hostname
2611 netmask - Subnet Mask
2612 rootpath - Pathname of the root filesystem on the NFS server
2613 serverip - see above
2616 There are two special Environment Variables:
2618 serial# - contains hardware identification information such
2619 as type string and/or serial number
2620 ethaddr - Ethernet address
2622 These variables can be set only once (usually during manufacturing of
2623 the board). U-Boot refuses to delete or overwrite these variables
2624 once they have been set once.
2627 Further special Environment Variables:
2629 ver - Contains the U-Boot version string as printed
2630 with the "version" command. This variable is
2631 readonly (see CONFIG_VERSION_VARIABLE).
2634 Please note that changes to some configuration parameters may take
2635 only effect after the next boot (yes, that's just like Windoze :-).
2638 Command Line Parsing:
2639 =====================
2641 There are two different command line parsers available with U-Boot:
2642 the old "simple" one, and the much more powerful "hush" shell:
2644 Old, simple command line parser:
2645 --------------------------------
2647 - supports environment variables (through setenv / saveenv commands)
2648 - several commands on one line, separated by ';'
2649 - variable substitution using "... ${name} ..." syntax
2650 - special characters ('$', ';') can be escaped by prefixing with '\',
2652 setenv bootcmd bootm \${address}
2653 - You can also escape text by enclosing in single apostrophes, for example:
2654 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
2659 - similar to Bourne shell, with control structures like
2660 if...then...else...fi, for...do...done; while...do...done,
2661 until...do...done, ...
2662 - supports environment ("global") variables (through setenv / saveenv
2663 commands) and local shell variables (through standard shell syntax
2664 "name=value"); only environment variables can be used with "run"
2670 (1) If a command line (or an environment variable executed by a "run"
2671 command) contains several commands separated by semicolon, and
2672 one of these commands fails, then the remaining commands will be
2675 (2) If you execute several variables with one call to run (i. e.
2676 calling run with a list af variables as arguments), any failing
2677 command will cause "run" to terminate, i. e. the remaining
2678 variables are not executed.
2680 Note for Redundant Ethernet Interfaces:
2681 =======================================
2683 Some boards come with redundant ethernet interfaces; U-Boot supports
2684 such configurations and is capable of automatic selection of a
2685 "working" interface when needed. MAC assignment works as follows:
2687 Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
2688 MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
2689 "eth1addr" (=>eth1), "eth2addr", ...
2691 If the network interface stores some valid MAC address (for instance
2692 in SROM), this is used as default address if there is NO correspon-
2693 ding setting in the environment; if the corresponding environment
2694 variable is set, this overrides the settings in the card; that means:
2696 o If the SROM has a valid MAC address, and there is no address in the
2697 environment, the SROM's address is used.
2699 o If there is no valid address in the SROM, and a definition in the
2700 environment exists, then the value from the environment variable is
2703 o If both the SROM and the environment contain a MAC address, and
2704 both addresses are the same, this MAC address is used.
2706 o If both the SROM and the environment contain a MAC address, and the
2707 addresses differ, the value from the environment is used and a
2710 o If neither SROM nor the environment contain a MAC address, an error
2717 The "boot" commands of this monitor operate on "image" files which
2718 can be basicly anything, preceeded by a special header; see the
2719 definitions in include/image.h for details; basicly, the header
2720 defines the following image properties:
2722 * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
2723 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
2724 LynxOS, pSOS, QNX, RTEMS, ARTOS;
2725 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, ARTOS, LynxOS).
2726 * Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86,
2727 IA64, MIPS, NIOS, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
2728 Currently supported: ARM, AVR32, Intel x86, MIPS, NIOS, PowerPC).
2729 * Compression Type (uncompressed, gzip, bzip2)
2735 The header is marked by a special Magic Number, and both the header
2736 and the data portions of the image are secured against corruption by
2743 Although U-Boot should support any OS or standalone application
2744 easily, the main focus has always been on Linux during the design of
2747 U-Boot includes many features that so far have been part of some
2748 special "boot loader" code within the Linux kernel. Also, any
2749 "initrd" images to be used are no longer part of one big Linux image;
2750 instead, kernel and "initrd" are separate images. This implementation
2751 serves several purposes:
2753 - the same features can be used for other OS or standalone
2754 applications (for instance: using compressed images to reduce the
2755 Flash memory footprint)
2757 - it becomes much easier to port new Linux kernel versions because
2758 lots of low-level, hardware dependent stuff are done by U-Boot
2760 - the same Linux kernel image can now be used with different "initrd"
2761 images; of course this also means that different kernel images can
2762 be run with the same "initrd". This makes testing easier (you don't
2763 have to build a new "zImage.initrd" Linux image when you just
2764 change a file in your "initrd"). Also, a field-upgrade of the
2765 software is easier now.
2771 Porting Linux to U-Boot based systems:
2772 ---------------------------------------
2774 U-Boot cannot save you from doing all the necessary modifications to
2775 configure the Linux device drivers for use with your target hardware
2776 (no, we don't intend to provide a full virtual machine interface to
2779 But now you can ignore ALL boot loader code (in arch/ppc/mbxboot).
2781 Just make sure your machine specific header file (for instance
2782 include/asm-ppc/tqm8xx.h) includes the same definition of the Board
2783 Information structure as we define in include/u-boot.h, and make
2784 sure that your definition of IMAP_ADDR uses the same value as your
2785 U-Boot configuration in CFG_IMMR.
2788 Configuring the Linux kernel:
2789 -----------------------------
2791 No specific requirements for U-Boot. Make sure you have some root
2792 device (initial ramdisk, NFS) for your target system.
2795 Building a Linux Image:
2796 -----------------------
2798 With U-Boot, "normal" build targets like "zImage" or "bzImage" are
2799 not used. If you use recent kernel source, a new build target
2800 "uImage" will exist which automatically builds an image usable by
2801 U-Boot. Most older kernels also have support for a "pImage" target,
2802 which was introduced for our predecessor project PPCBoot and uses a
2803 100% compatible format.
2812 The "uImage" build target uses a special tool (in 'tools/mkimage') to
2813 encapsulate a compressed Linux kernel image with header information,
2814 CRC32 checksum etc. for use with U-Boot. This is what we are doing:
2816 * build a standard "vmlinux" kernel image (in ELF binary format):
2818 * convert the kernel into a raw binary image:
2820 ${CROSS_COMPILE}-objcopy -O binary \
2821 -R .note -R .comment \
2822 -S vmlinux linux.bin
2824 * compress the binary image:
2828 * package compressed binary image for U-Boot:
2830 mkimage -A ppc -O linux -T kernel -C gzip \
2831 -a 0 -e 0 -n "Linux Kernel Image" \
2832 -d linux.bin.gz uImage
2835 The "mkimage" tool can also be used to create ramdisk images for use
2836 with U-Boot, either separated from the Linux kernel image, or
2837 combined into one file. "mkimage" encapsulates the images with a 64
2838 byte header containing information about target architecture,
2839 operating system, image type, compression method, entry points, time
2840 stamp, CRC32 checksums, etc.
2842 "mkimage" can be called in two ways: to verify existing images and
2843 print the header information, or to build new images.
2845 In the first form (with "-l" option) mkimage lists the information
2846 contained in the header of an existing U-Boot image; this includes
2847 checksum verification:
2849 tools/mkimage -l image
2850 -l ==> list image header information
2852 The second form (with "-d" option) is used to build a U-Boot image
2853 from a "data file" which is used as image payload:
2855 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
2856 -n name -d data_file image
2857 -A ==> set architecture to 'arch'
2858 -O ==> set operating system to 'os'
2859 -T ==> set image type to 'type'
2860 -C ==> set compression type 'comp'
2861 -a ==> set load address to 'addr' (hex)
2862 -e ==> set entry point to 'ep' (hex)
2863 -n ==> set image name to 'name'
2864 -d ==> use image data from 'datafile'
2866 Right now, all Linux kernels for PowerPC systems use the same load
2867 address (0x00000000), but the entry point address depends on the
2870 - 2.2.x kernels have the entry point at 0x0000000C,
2871 - 2.3.x and later kernels have the entry point at 0x00000000.
2873 So a typical call to build a U-Boot image would read:
2875 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
2876 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
2877 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux.gz \
2878 > examples/uImage.TQM850L
2879 Image Name: 2.4.4 kernel for TQM850L
2880 Created: Wed Jul 19 02:34:59 2000
2881 Image Type: PowerPC Linux Kernel Image (gzip compressed)
2882 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
2883 Load Address: 0x00000000
2884 Entry Point: 0x00000000
2886 To verify the contents of the image (or check for corruption):
2888 -> tools/mkimage -l examples/uImage.TQM850L
2889 Image Name: 2.4.4 kernel for TQM850L
2890 Created: Wed Jul 19 02:34:59 2000
2891 Image Type: PowerPC Linux Kernel Image (gzip compressed)
2892 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
2893 Load Address: 0x00000000
2894 Entry Point: 0x00000000
2896 NOTE: for embedded systems where boot time is critical you can trade
2897 speed for memory and install an UNCOMPRESSED image instead: this
2898 needs more space in Flash, but boots much faster since it does not
2899 need to be uncompressed:
2901 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux.gz
2902 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
2903 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
2904 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux \
2905 > examples/uImage.TQM850L-uncompressed
2906 Image Name: 2.4.4 kernel for TQM850L
2907 Created: Wed Jul 19 02:34:59 2000
2908 Image Type: PowerPC Linux Kernel Image (uncompressed)
2909 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
2910 Load Address: 0x00000000
2911 Entry Point: 0x00000000
2914 Similar you can build U-Boot images from a 'ramdisk.image.gz' file
2915 when your kernel is intended to use an initial ramdisk:
2917 -> tools/mkimage -n 'Simple Ramdisk Image' \
2918 > -A ppc -O linux -T ramdisk -C gzip \
2919 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
2920 Image Name: Simple Ramdisk Image
2921 Created: Wed Jan 12 14:01:50 2000
2922 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
2923 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
2924 Load Address: 0x00000000
2925 Entry Point: 0x00000000
2928 Installing a Linux Image:
2929 -------------------------
2931 To downloading a U-Boot image over the serial (console) interface,
2932 you must convert the image to S-Record format:
2934 objcopy -I binary -O srec examples/image examples/image.srec
2936 The 'objcopy' does not understand the information in the U-Boot
2937 image header, so the resulting S-Record file will be relative to
2938 address 0x00000000. To load it to a given address, you need to
2939 specify the target address as 'offset' parameter with the 'loads'
2942 Example: install the image to address 0x40100000 (which on the
2943 TQM8xxL is in the first Flash bank):
2945 => erase 40100000 401FFFFF
2951 ## Ready for S-Record download ...
2952 ~>examples/image.srec
2953 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
2955 15989 15990 15991 15992
2956 [file transfer complete]
2958 ## Start Addr = 0x00000000
2961 You can check the success of the download using the 'iminfo' command;
2962 this includes a checksum verification so you can be sure no data
2963 corruption happened:
2967 ## Checking Image at 40100000 ...
2968 Image Name: 2.2.13 for initrd on TQM850L
2969 Image Type: PowerPC Linux Kernel Image (gzip compressed)
2970 Data Size: 335725 Bytes = 327 kB = 0 MB
2971 Load Address: 00000000
2972 Entry Point: 0000000c
2973 Verifying Checksum ... OK
2979 The "bootm" command is used to boot an application that is stored in
2980 memory (RAM or Flash). In case of a Linux kernel image, the contents
2981 of the "bootargs" environment variable is passed to the kernel as
2982 parameters. You can check and modify this variable using the
2983 "printenv" and "setenv" commands:
2986 => printenv bootargs
2987 bootargs=root=/dev/ram
2989 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
2991 => printenv bootargs
2992 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
2995 ## Booting Linux kernel at 40020000 ...
2996 Image Name: 2.2.13 for NFS on TQM850L
2997 Image Type: PowerPC Linux Kernel Image (gzip compressed)
2998 Data Size: 381681 Bytes = 372 kB = 0 MB
2999 Load Address: 00000000
3000 Entry Point: 0000000c
3001 Verifying Checksum ... OK
3002 Uncompressing Kernel Image ... OK
3003 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
3004 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
3005 time_init: decrementer frequency = 187500000/60
3006 Calibrating delay loop... 49.77 BogoMIPS
3007 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
3010 If you want to boot a Linux kernel with initial ram disk, you pass
3011 the memory addresses of both the kernel and the initrd image (PPBCOOT
3012 format!) to the "bootm" command:
3014 => imi 40100000 40200000
3016 ## Checking Image at 40100000 ...
3017 Image Name: 2.2.13 for initrd on TQM850L
3018 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3019 Data Size: 335725 Bytes = 327 kB = 0 MB
3020 Load Address: 00000000
3021 Entry Point: 0000000c
3022 Verifying Checksum ... OK
3024 ## Checking Image at 40200000 ...
3025 Image Name: Simple Ramdisk Image
3026 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
3027 Data Size: 566530 Bytes = 553 kB = 0 MB
3028 Load Address: 00000000
3029 Entry Point: 00000000
3030 Verifying Checksum ... OK
3032 => bootm 40100000 40200000
3033 ## Booting Linux kernel at 40100000 ...
3034 Image Name: 2.2.13 for initrd on TQM850L
3035 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3036 Data Size: 335725 Bytes = 327 kB = 0 MB
3037 Load Address: 00000000
3038 Entry Point: 0000000c
3039 Verifying Checksum ... OK
3040 Uncompressing Kernel Image ... OK
3041 ## Loading RAMDisk Image at 40200000 ...
3042 Image Name: Simple Ramdisk Image
3043 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
3044 Data Size: 566530 Bytes = 553 kB = 0 MB
3045 Load Address: 00000000
3046 Entry Point: 00000000
3047 Verifying Checksum ... OK
3048 Loading Ramdisk ... OK
3049 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
3050 Boot arguments: root=/dev/ram
3051 time_init: decrementer frequency = 187500000/60
3052 Calibrating delay loop... 49.77 BogoMIPS
3054 RAMDISK: Compressed image found at block 0
3055 VFS: Mounted root (ext2 filesystem).
3059 More About U-Boot Image Types:
3060 ------------------------------
3062 U-Boot supports the following image types:
3064 "Standalone Programs" are directly runnable in the environment
3065 provided by U-Boot; it is expected that (if they behave
3066 well) you can continue to work in U-Boot after return from
3067 the Standalone Program.
3068 "OS Kernel Images" are usually images of some Embedded OS which
3069 will take over control completely. Usually these programs
3070 will install their own set of exception handlers, device
3071 drivers, set up the MMU, etc. - this means, that you cannot
3072 expect to re-enter U-Boot except by resetting the CPU.
3073 "RAMDisk Images" are more or less just data blocks, and their
3074 parameters (address, size) are passed to an OS kernel that is
3076 "Multi-File Images" contain several images, typically an OS
3077 (Linux) kernel image and one or more data images like
3078 RAMDisks. This construct is useful for instance when you want
3079 to boot over the network using BOOTP etc., where the boot
3080 server provides just a single image file, but you want to get
3081 for instance an OS kernel and a RAMDisk image.
3083 "Multi-File Images" start with a list of image sizes, each
3084 image size (in bytes) specified by an "uint32_t" in network
3085 byte order. This list is terminated by an "(uint32_t)0".
3086 Immediately after the terminating 0 follow the images, one by
3087 one, all aligned on "uint32_t" boundaries (size rounded up to
3088 a multiple of 4 bytes).
3090 "Firmware Images" are binary images containing firmware (like
3091 U-Boot or FPGA images) which usually will be programmed to
3094 "Script files" are command sequences that will be executed by
3095 U-Boot's command interpreter; this feature is especially
3096 useful when you configure U-Boot to use a real shell (hush)
3097 as command interpreter.
3103 One of the features of U-Boot is that you can dynamically load and
3104 run "standalone" applications, which can use some resources of
3105 U-Boot like console I/O functions or interrupt services.
3107 Two simple examples are included with the sources:
3112 'examples/hello_world.c' contains a small "Hello World" Demo
3113 application; it is automatically compiled when you build U-Boot.
3114 It's configured to run at address 0x00040004, so you can play with it
3118 ## Ready for S-Record download ...
3119 ~>examples/hello_world.srec
3120 1 2 3 4 5 6 7 8 9 10 11 ...
3121 [file transfer complete]
3123 ## Start Addr = 0x00040004
3125 => go 40004 Hello World! This is a test.
3126 ## Starting application at 0x00040004 ...
3137 Hit any key to exit ...
3139 ## Application terminated, rc = 0x0
3141 Another example, which demonstrates how to register a CPM interrupt
3142 handler with the U-Boot code, can be found in 'examples/timer.c'.
3143 Here, a CPM timer is set up to generate an interrupt every second.
3144 The interrupt service routine is trivial, just printing a '.'
3145 character, but this is just a demo program. The application can be
3146 controlled by the following keys:
3148 ? - print current values og the CPM Timer registers
3149 b - enable interrupts and start timer
3150 e - stop timer and disable interrupts
3151 q - quit application
3154 ## Ready for S-Record download ...
3155 ~>examples/timer.srec
3156 1 2 3 4 5 6 7 8 9 10 11 ...
3157 [file transfer complete]
3159 ## Start Addr = 0x00040004
3162 ## Starting application at 0x00040004 ...
3165 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
3168 [q, b, e, ?] Set interval 1000000 us
3171 [q, b, e, ?] ........
3172 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
3175 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
3178 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
3181 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
3183 [q, b, e, ?] ...Stopping timer
3185 [q, b, e, ?] ## Application terminated, rc = 0x0
3191 Over time, many people have reported problems when trying to use the
3192 "minicom" terminal emulation program for serial download. I (wd)
3193 consider minicom to be broken, and recommend not to use it. Under
3194 Unix, I recommend to use C-Kermit for general purpose use (and
3195 especially for kermit binary protocol download ("loadb" command), and
3196 use "cu" for S-Record download ("loads" command).
3198 Nevertheless, if you absolutely want to use it try adding this
3199 configuration to your "File transfer protocols" section:
3201 Name Program Name U/D FullScr IO-Red. Multi
3202 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
3203 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
3209 Starting at version 0.9.2, U-Boot supports NetBSD both as host
3210 (build U-Boot) and target system (boots NetBSD/mpc8xx).
3212 Building requires a cross environment; it is known to work on
3213 NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
3214 need gmake since the Makefiles are not compatible with BSD make).
3215 Note that the cross-powerpc package does not install include files;
3216 attempting to build U-Boot will fail because <machine/ansi.h> is
3217 missing. This file has to be installed and patched manually:
3219 # cd /usr/pkg/cross/powerpc-netbsd/include
3221 # ln -s powerpc machine
3222 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
3223 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
3225 Native builds *don't* work due to incompatibilities between native
3226 and U-Boot include files.
3228 Booting assumes that (the first part of) the image booted is a
3229 stage-2 loader which in turn loads and then invokes the kernel
3230 proper. Loader sources will eventually appear in the NetBSD source
3231 tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
3232 meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz
3235 Implementation Internals:
3236 =========================
3238 The following is not intended to be a complete description of every
3239 implementation detail. However, it should help to understand the
3240 inner workings of U-Boot and make it easier to port it to custom
3244 Initial Stack, Global Data:
3245 ---------------------------
3247 The implementation of U-Boot is complicated by the fact that U-Boot
3248 starts running out of ROM (flash memory), usually without access to
3249 system RAM (because the memory controller is not initialized yet).
3250 This means that we don't have writable Data or BSS segments, and BSS
3251 is not initialized as zero. To be able to get a C environment working
3252 at all, we have to allocate at least a minimal stack. Implementation
3253 options for this are defined and restricted by the CPU used: Some CPU
3254 models provide on-chip memory (like the IMMR area on MPC8xx and
3255 MPC826x processors), on others (parts of) the data cache can be
3256 locked as (mis-) used as memory, etc.
3258 Chris Hallinan posted a good summary of these issues to the
3259 u-boot-users mailing list:
3261 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
3262 From: "Chris Hallinan" <clh@net1plus.com>
3263 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
3266 Correct me if I'm wrong, folks, but the way I understand it
3267 is this: Using DCACHE as initial RAM for Stack, etc, does not
3268 require any physical RAM backing up the cache. The cleverness
3269 is that the cache is being used as a temporary supply of
3270 necessary storage before the SDRAM controller is setup. It's
3271 beyond the scope of this list to expain the details, but you
3272 can see how this works by studying the cache architecture and
3273 operation in the architecture and processor-specific manuals.
3275 OCM is On Chip Memory, which I believe the 405GP has 4K. It
3276 is another option for the system designer to use as an
3277 initial stack/ram area prior to SDRAM being available. Either
3278 option should work for you. Using CS 4 should be fine if your
3279 board designers haven't used it for something that would
3280 cause you grief during the initial boot! It is frequently not
3283 CFG_INIT_RAM_ADDR should be somewhere that won't interfere
3284 with your processor/board/system design. The default value
3285 you will find in any recent u-boot distribution in
3286 walnut.h should work for you. I'd set it to a value larger
3287 than your SDRAM module. If you have a 64MB SDRAM module, set
3288 it above 400_0000. Just make sure your board has no resources
3289 that are supposed to respond to that address! That code in
3290 start.S has been around a while and should work as is when
3291 you get the config right.
3296 It is essential to remember this, since it has some impact on the C
3297 code for the initialization procedures:
3299 * Initialized global data (data segment) is read-only. Do not attempt
3302 * Do not use any unitialized global data (or implicitely initialized
3303 as zero data - BSS segment) at all - this is undefined, initiali-
3304 zation is performed later (when relocating to RAM).
3306 * Stack space is very limited. Avoid big data buffers or things like
3309 Having only the stack as writable memory limits means we cannot use
3310 normal global data to share information beween the code. But it
3311 turned out that the implementation of U-Boot can be greatly
3312 simplified by making a global data structure (gd_t) available to all
3313 functions. We could pass a pointer to this data as argument to _all_
3314 functions, but this would bloat the code. Instead we use a feature of
3315 the GCC compiler (Global Register Variables) to share the data: we
3316 place a pointer (gd) to the global data into a register which we
3317 reserve for this purpose.
3319 When choosing a register for such a purpose we are restricted by the
3320 relevant (E)ABI specifications for the current architecture, and by
3321 GCC's implementation.
3323 For PowerPC, the following registers have specific use:
3326 R3-R4: parameter passing and return values
3327 R5-R10: parameter passing
3328 R13: small data area pointer
3332 (U-Boot also uses R14 as internal GOT pointer.)
3334 ==> U-Boot will use R29 to hold a pointer to the global data
3336 Note: on PPC, we could use a static initializer (since the
3337 address of the global data structure is known at compile time),
3338 but it turned out that reserving a register results in somewhat
3339 smaller code - although the code savings are not that big (on
3340 average for all boards 752 bytes for the whole U-Boot image,
3341 624 text + 127 data).
3343 On ARM, the following registers are used:
3345 R0: function argument word/integer result
3346 R1-R3: function argument word
3348 R10: stack limit (used only if stack checking if enabled)
3349 R11: argument (frame) pointer
3350 R12: temporary workspace
3353 R15: program counter
3355 ==> U-Boot will use R8 to hold a pointer to the global data
3357 NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope,
3358 or current versions of GCC may "optimize" the code too much.
3363 U-Boot runs in system state and uses physical addresses, i.e. the
3364 MMU is not used either for address mapping nor for memory protection.
3366 The available memory is mapped to fixed addresses using the memory
3367 controller. In this process, a contiguous block is formed for each
3368 memory type (Flash, SDRAM, SRAM), even when it consists of several
3369 physical memory banks.
3371 U-Boot is installed in the first 128 kB of the first Flash bank (on
3372 TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
3373 booting and sizing and initializing DRAM, the code relocates itself
3374 to the upper end of DRAM. Immediately below the U-Boot code some
3375 memory is reserved for use by malloc() [see CFG_MALLOC_LEN
3376 configuration setting]. Below that, a structure with global Board
3377 Info data is placed, followed by the stack (growing downward).
3379 Additionally, some exception handler code is copied to the low 8 kB
3380 of DRAM (0x00000000 ... 0x00001FFF).
3382 So a typical memory configuration with 16 MB of DRAM could look like
3385 0x0000 0000 Exception Vector code
3388 0x0000 2000 Free for Application Use
3394 0x00FB FF20 Monitor Stack (Growing downward)
3395 0x00FB FFAC Board Info Data and permanent copy of global data
3396 0x00FC 0000 Malloc Arena
3399 0x00FE 0000 RAM Copy of Monitor Code
3400 ... eventually: LCD or video framebuffer
3401 ... eventually: pRAM (Protected RAM - unchanged by reset)
3402 0x00FF FFFF [End of RAM]
3405 System Initialization:
3406 ----------------------
3408 In the reset configuration, U-Boot starts at the reset entry point
3409 (on most PowerPC systens at address 0x00000100). Because of the reset
3410 configuration for CS0# this is a mirror of the onboard Flash memory.
3411 To be able to re-map memory U-Boot then jumps to its link address.
3412 To be able to implement the initialization code in C, a (small!)
3413 initial stack is set up in the internal Dual Ported RAM (in case CPUs
3414 which provide such a feature like MPC8xx or MPC8260), or in a locked
3415 part of the data cache. After that, U-Boot initializes the CPU core,
3416 the caches and the SIU.
3418 Next, all (potentially) available memory banks are mapped using a
3419 preliminary mapping. For example, we put them on 512 MB boundaries
3420 (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
3421 on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
3422 programmed for SDRAM access. Using the temporary configuration, a
3423 simple memory test is run that determines the size of the SDRAM
3426 When there is more than one SDRAM bank, and the banks are of
3427 different size, the largest is mapped first. For equal size, the first
3428 bank (CS2#) is mapped first. The first mapping is always for address
3429 0x00000000, with any additional banks following immediately to create
3430 contiguous memory starting from 0.
3432 Then, the monitor installs itself at the upper end of the SDRAM area
3433 and allocates memory for use by malloc() and for the global Board
3434 Info data; also, the exception vector code is copied to the low RAM
3435 pages, and the final stack is set up.
3437 Only after this relocation will you have a "normal" C environment;
3438 until that you are restricted in several ways, mostly because you are
3439 running from ROM, and because the code will have to be relocated to a
3443 U-Boot Porting Guide:
3444 ----------------------
3446 [Based on messages by Jerry Van Baren in the U-Boot-Users mailing
3450 int main (int argc, char *argv[])
3452 sighandler_t no_more_time;
3454 signal (SIGALRM, no_more_time);
3455 alarm (PROJECT_DEADLINE - toSec (3 * WEEK));
3457 if (available_money > available_manpower) {
3458 pay consultant to port U-Boot;
3462 Download latest U-Boot source;
3464 Subscribe to u-boot-users mailing list;
3467 email ("Hi, I am new to U-Boot, how do I get started?");
3471 Read the README file in the top level directory;
3472 Read http://www.denx.de/twiki/bin/view/DULG/Manual ;
3473 Read the source, Luke;
3476 if (available_money > toLocalCurrency ($2500)) {
3479 Add a lot of aggravation and time;
3482 Create your own board support subdirectory;
3484 Create your own board config file;
3488 Add / modify source code;
3492 email ("Hi, I am having problems...");
3494 Send patch file to Wolfgang;
3499 void no_more_time (int sig)
3508 All contributions to U-Boot should conform to the Linux kernel
3509 coding style; see the file "Documentation/CodingStyle" and the script
3510 "scripts/Lindent" in your Linux kernel source directory. In sources
3511 originating from U-Boot a style corresponding to "Lindent -pcs" (adding
3512 spaces before parameters to function calls) is actually used.
3514 Source files originating from a different project (for example the
3515 MTD subsystem) are generally exempt from these guidelines and are not
3516 reformated to ease subsequent migration to newer versions of those
3519 Please note that U-Boot is implemented in C (and to some small parts in
3520 Assembler); no C++ is used, so please do not use C++ style comments (//)
3523 Please also stick to the following formatting rules:
3524 - remove any trailing white space
3525 - use TAB characters for indentation, not spaces
3526 - make sure NOT to use DOS '\r\n' line feeds
3527 - do not add more than 2 empty lines to source files
3528 - do not add trailing empty lines to source files
3530 Submissions which do not conform to the standards may be returned
3531 with a request to reformat the changes.
3537 Since the number of patches for U-Boot is growing, we need to
3538 establish some rules. Submissions which do not conform to these rules
3539 may be rejected, even when they contain important and valuable stuff.
3541 Patches shall be sent to the u-boot-users mailing list.
3543 When you send a patch, please include the following information with
3546 * For bug fixes: a description of the bug and how your patch fixes
3547 this bug. Please try to include a way of demonstrating that the
3548 patch actually fixes something.
3550 * For new features: a description of the feature and your
3553 * A CHANGELOG entry as plaintext (separate from the patch)
3555 * For major contributions, your entry to the CREDITS file
3557 * When you add support for a new board, don't forget to add this
3558 board to the MAKEALL script, too.
3560 * If your patch adds new configuration options, don't forget to
3561 document these in the README file.
3563 * The patch itself. If you are accessing the CVS repository use "cvs
3564 update; cvs diff -puRN"; else, use "diff -purN OLD NEW". If your
3565 version of diff does not support these options, then get the latest
3566 version of GNU diff.
3568 The current directory when running this command shall be the top
3569 level directory of the U-Boot source tree, or it's parent directory
3570 (i. e. please make sure that your patch includes sufficient
3571 directory information for the affected files).
3573 We accept patches as plain text, MIME attachments or as uuencoded
3576 * If one logical set of modifications affects or creates several
3577 files, all these changes shall be submitted in a SINGLE patch file.
3579 * Changesets that contain different, unrelated modifications shall be
3580 submitted as SEPARATE patches, one patch per changeset.
3585 * Before sending the patch, run the MAKEALL script on your patched
3586 source tree and make sure that no errors or warnings are reported
3587 for any of the boards.
3589 * Keep your modifications to the necessary minimum: A patch
3590 containing several unrelated changes or arbitrary reformats will be
3591 returned with a request to re-formatting / split it.
3593 * If you modify existing code, make sure that your new code does not
3594 add to the memory footprint of the code ;-) Small is beautiful!
3595 When adding new features, these should compile conditionally only
3596 (using #ifdef), and the resulting code with the new feature
3597 disabled must not need more memory than the old code without your
3600 * Remember that there is a size limit of 40 kB per message on the
3601 u-boot-users mailing list. Compression may help.
projects / oweals / u-boot.git / blob