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 IBM PowerPC 4xx CPUs
149 - pxa Files specific to Intel XScale PXA CPUs
150 - s3c44b0 Files specific to Samsung S3C44B0 CPUs
151 - sa1100 Files specific to Intel StrongARM SA1100 CPUs
152 - disk Code for disk drive partition handling
153 - doc Documentation (don't expect too much)
154 - drivers Commonly used device drivers
155 - dtt Digital Thermometer and Thermostat drivers
156 - examples Example code for standalone applications, etc.
157 - include Header Files
158 - lib_arm Files generic to ARM architecture
159 - lib_generic Files generic to all architectures
160 - lib_i386 Files generic to i386 architecture
161 - lib_m68k Files generic to m68k architecture
162 - lib_mips Files generic to MIPS architecture
163 - lib_nios Files generic to NIOS architecture
164 - lib_ppc Files generic to PowerPC architecture
165 - net Networking code
166 - post Power On Self Test
167 - rtc Real Time Clock drivers
168 - tools Tools to build S-Record or U-Boot images, etc.
170 Software Configuration:
171 =======================
173 Configuration is usually done using C preprocessor defines; the
174 rationale behind that is to avoid dead code whenever possible.
176 There are two classes of configuration variables:
178 * Configuration _OPTIONS_:
179 These are selectable by the user and have names beginning with
182 * Configuration _SETTINGS_:
183 These depend on the hardware etc. and should not be meddled with if
184 you don't know what you're doing; they have names beginning with
187 Later we will add a configuration tool - probably similar to or even
188 identical to what's used for the Linux kernel. Right now, we have to
189 do the configuration by hand, which means creating some symbolic
190 links and editing some configuration files. We use the TQM8xxL boards
194 Selection of Processor Architecture and Board Type:
195 ---------------------------------------------------
197 For all supported boards there are ready-to-use default
198 configurations available; just type "make <board_name>_config".
200 Example: For a TQM823L module type:
205 For the Cogent platform, you need to specify the cpu type as well;
206 e.g. "make cogent_mpc8xx_config". And also configure the cogent
207 directory according to the instructions in cogent/README.
210 Configuration Options:
211 ----------------------
213 Configuration depends on the combination of board and CPU type; all
214 such information is kept in a configuration file
215 "include/configs/<board_name>.h".
217 Example: For a TQM823L module, all configuration settings are in
218 "include/configs/TQM823L.h".
221 Many of the options are named exactly as the corresponding Linux
222 kernel configuration options. The intention is to make it easier to
223 build a config tool - later.
226 The following options need to be configured:
228 - CPU Type: Define exactly one of
232 CONFIG_MPC823, CONFIG_MPC850, CONFIG_MPC855, CONFIG_MPC860
235 or CONFIG_MPC824X, CONFIG_MPC8260
250 MicroBlaze based CPUs:
251 ----------------------
255 ----------------------
259 - Board Type: Define exactly one of
261 PowerPC based boards:
262 ---------------------
264 CONFIG_ADCIOP CONFIG_GEN860T CONFIG_PCI405
265 CONFIG_ADS860 CONFIG_GENIETV CONFIG_PCIPPC2
266 CONFIG_AMX860 CONFIG_GTH CONFIG_PCIPPC6
267 CONFIG_AR405 CONFIG_gw8260 CONFIG_pcu_e
268 CONFIG_BAB7xx CONFIG_hermes CONFIG_PIP405
269 CONFIG_c2mon CONFIG_hymod CONFIG_PM826
270 CONFIG_CANBT CONFIG_IAD210 CONFIG_ppmc8260
271 CONFIG_CCM CONFIG_ICU862 CONFIG_QS823
272 CONFIG_CMI CONFIG_IP860 CONFIG_QS850
273 CONFIG_cogent_mpc8260 CONFIG_IPHASE4539 CONFIG_QS860T
274 CONFIG_cogent_mpc8xx CONFIG_IVML24 CONFIG_RBC823
275 CONFIG_CPCI405 CONFIG_IVML24_128 CONFIG_RPXClassic
276 CONFIG_CPCI4052 CONFIG_IVML24_256 CONFIG_RPXlite
277 CONFIG_CPCIISER4 CONFIG_IVMS8 CONFIG_RPXsuper
278 CONFIG_CPU86 CONFIG_IVMS8_128 CONFIG_rsdproto
279 CONFIG_CRAYL1 CONFIG_IVMS8_256 CONFIG_sacsng
280 CONFIG_CSB272 CONFIG_JSE CONFIG_Sandpoint8240
281 CONFIG_CU824 CONFIG_LANTEC CONFIG_Sandpoint8245
282 CONFIG_DASA_SIM CONFIG_lwmon CONFIG_sbc8260
283 CONFIG_DB64360 CONFIG_MBX CONFIG_sbc8560
284 CONFIG_DB64460 CONFIG_MBX860T CONFIG_SM850
285 CONFIG_DU405 CONFIG_MHPC CONFIG_SPD823TS
286 CONFIG_DUET_ADS CONFIG_MIP405 CONFIG_STXGP3
287 CONFIG_EBONY CONFIG_MOUSSE CONFIG_SXNI855T
288 CONFIG_ELPPC CONFIG_MPC8260ADS CONFIG_TQM823L
289 CONFIG_ELPT860 CONFIG_MPC8540ADS CONFIG_TQM8260
290 CONFIG_ep8260 CONFIG_MPC8560ADS CONFIG_TQM850L
291 CONFIG_ERIC CONFIG_MUSENKI CONFIG_TQM855L
292 CONFIG_ESTEEM192E CONFIG_MVS1 CONFIG_TQM860L
293 CONFIG_ETX094 CONFIG_NETPHONE CONFIG_TTTech
294 CONFIG_EVB64260 CONFIG_NETTA CONFIG_UTX8245
295 CONFIG_FADS823 CONFIG_NETVIA CONFIG_V37
296 CONFIG_FADS850SAR CONFIG_NX823 CONFIG_W7OLMC
297 CONFIG_FADS860T CONFIG_OCRTC CONFIG_W7OLMG
298 CONFIG_FLAGADM CONFIG_ORSG CONFIG_WALNUT
299 CONFIG_FPS850L CONFIG_OXC CONFIG_ZPC1900
300 CONFIG_FPS860L CONFIG_ZUMA
305 CONFIG_AT91RM9200DK, CONFIG_CERF250, CONFIG_DNP1110,
306 CONFIG_EP7312, CONFIG_H2_OMAP1610, CONFIG_HHP_CRADLE,
307 CONFIG_IMPA7, CONFIG_INNOVATOROMAP1510, CONFIG_INNOVATOROMAP1610,
308 CONFIG_LART, CONFIG_LPD7A400 CONFIG_LUBBOCK,
309 CONFIG_OSK_OMAP5912, CONFIG_OMAP2420H4, CONFIG_SHANNON,
310 CONFIG_P2_OMAP730, CONFIG_SMDK2400, CONFIG_SMDK2410,
311 CONFIG_TRAB, CONFIG_VCMA9
313 MicroBlaze based boards:
314 ------------------------
319 ------------------------
321 CONFIG_PCI5441 CONFIG_PK1C20
324 - CPU Module Type: (if CONFIG_COGENT is defined)
325 Define exactly one of
327 --- FIXME --- not tested yet:
328 CONFIG_CMA286_60, CONFIG_CMA286_21, CONFIG_CMA286_60P,
329 CONFIG_CMA287_23, CONFIG_CMA287_50
331 - Motherboard Type: (if CONFIG_COGENT is defined)
332 Define exactly one of
333 CONFIG_CMA101, CONFIG_CMA102
335 - Motherboard I/O Modules: (if CONFIG_COGENT is defined)
336 Define one or more of
339 - Motherboard Options: (if CONFIG_CMA101 or CONFIG_CMA102 are defined)
340 Define one or more of
341 CONFIG_LCD_HEARTBEAT - update a character position on
342 the lcd display every second with
345 - Board flavour: (if CONFIG_MPC8260ADS is defined)
348 CFG_8260ADS - original MPC8260ADS
349 CFG_8266ADS - MPC8266ADS
350 CFG_PQ2FADS - PQ2FADS-ZU or PQ2FADS-VR
351 CFG_8272ADS - MPC8272ADS
353 - MPC824X Family Member (if CONFIG_MPC824X is defined)
354 Define exactly one of
355 CONFIG_MPC8240, CONFIG_MPC8245
357 - 8xx CPU Options: (if using an MPC8xx cpu)
358 CONFIG_8xx_GCLK_FREQ - deprecated: CPU clock if
359 get_gclk_freq() cannot work
360 e.g. if there is no 32KHz
361 reference PIT/RTC clock
362 CONFIG_8xx_OSCLK - PLL input clock (either EXTCLK
365 - 859/866/885 CPU options: (if using a MPC859 or MPC866 or MPC885 CPU):
368 CONFIG_8xx_CPUCLK_DEFAULT
369 See doc/README.MPC866
373 Define this to measure the actual CPU clock instead
374 of relying on the correctness of the configured
375 values. Mostly useful for board bringup to make sure
376 the PLL is locked at the intended frequency. Note
377 that this requires a (stable) reference clock (32 kHz
378 RTC clock or CFG_8XX_XIN)
380 - Linux Kernel Interface:
383 U-Boot stores all clock information in Hz
384 internally. For binary compatibility with older Linux
385 kernels (which expect the clocks passed in the
386 bd_info data to be in MHz) the environment variable
387 "clocks_in_mhz" can be defined so that U-Boot
388 converts clock data to MHZ before passing it to the
390 When CONFIG_CLOCKS_IN_MHZ is defined, a definition of
391 "clocks_in_mhz=1" is automatically included in the
394 CONFIG_MEMSIZE_IN_BYTES [relevant for MIPS only]
396 When transfering memsize parameter to linux, some versions
397 expect it to be in bytes, others in MB.
398 Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes.
403 Define this if you want support for Amba PrimeCell PL010 UARTs.
407 Define this if you want support for Amba PrimeCell PL011 UARTs.
411 If you have Amba PrimeCell PL011 UARTs, set this variable to
412 the clock speed of the UARTs.
416 If you have Amba PrimeCell PL010 or PL011 UARTs on your board,
417 define this to a list of base addresses for each (supported)
418 port. See e.g. include/configs/versatile.h
422 Depending on board, define exactly one serial port
423 (like CONFIG_8xx_CONS_SMC1, CONFIG_8xx_CONS_SMC2,
424 CONFIG_8xx_CONS_SCC1, ...), or switch off the serial
425 console by defining CONFIG_8xx_CONS_NONE
427 Note: if CONFIG_8xx_CONS_NONE is defined, the serial
428 port routines must be defined elsewhere
429 (i.e. serial_init(), serial_getc(), ...)
432 Enables console device for a color framebuffer. Needs following
433 defines (cf. smiLynxEM, i8042, board/eltec/bab7xx)
434 VIDEO_FB_LITTLE_ENDIAN graphic memory organisation
436 VIDEO_HW_RECTFILL graphic chip supports
439 VIDEO_HW_BITBLT graphic chip supports
440 bit-blit (cf. smiLynxEM)
441 VIDEO_VISIBLE_COLS visible pixel columns
443 VIDEO_VISIBLE_ROWS visible pixel rows
444 VIDEO_PIXEL_SIZE bytes per pixel
445 VIDEO_DATA_FORMAT graphic data format
446 (0-5, cf. cfb_console.c)
447 VIDEO_FB_ADRS framebuffer address
448 VIDEO_KBD_INIT_FCT keyboard int fct
449 (i.e. i8042_kbd_init())
450 VIDEO_TSTC_FCT test char fct
452 VIDEO_GETC_FCT get char fct
454 CONFIG_CONSOLE_CURSOR cursor drawing on/off
455 (requires blink timer
457 CFG_CONSOLE_BLINK_COUNT blink interval (cf. i8042.c)
458 CONFIG_CONSOLE_TIME display time/date info in
460 (requires CFG_CMD_DATE)
461 CONFIG_VIDEO_LOGO display Linux logo in
463 CONFIG_VIDEO_BMP_LOGO use bmp_logo.h instead of
464 linux_logo.h for logo.
465 Requires CONFIG_VIDEO_LOGO
466 CONFIG_CONSOLE_EXTRA_INFO
467 addional board info beside
470 When CONFIG_CFB_CONSOLE is defined, video console is
471 default i/o. Serial console can be forced with
472 environment 'console=serial'.
474 When CONFIG_SILENT_CONSOLE is defined, all console
475 messages (by U-Boot and Linux!) can be silenced with
476 the "silent" environment variable. See
477 doc/README.silent for more information.
480 CONFIG_BAUDRATE - in bps
481 Select one of the baudrates listed in
482 CFG_BAUDRATE_TABLE, see below.
483 CFG_BRGCLK_PRESCALE, baudrate prescale
485 - Interrupt driven serial port input:
486 CONFIG_SERIAL_SOFTWARE_FIFO
489 Use an interrupt handler for receiving data on the
490 serial port. It also enables using hardware handshake
491 (RTS/CTS) and UART's built-in FIFO. Set the number of
492 bytes the interrupt driven input buffer should have.
494 Leave undefined to disable this feature, including
495 disable the buffer and hardware handshake.
497 - Console UART Number:
501 If defined internal UART1 (and not UART0) is used
502 as default U-Boot console.
504 - Boot Delay: CONFIG_BOOTDELAY - in seconds
505 Delay before automatically booting the default image;
506 set to -1 to disable autoboot.
508 See doc/README.autoboot for these options that
509 work with CONFIG_BOOTDELAY. None are required.
510 CONFIG_BOOT_RETRY_TIME
511 CONFIG_BOOT_RETRY_MIN
512 CONFIG_AUTOBOOT_KEYED
513 CONFIG_AUTOBOOT_PROMPT
514 CONFIG_AUTOBOOT_DELAY_STR
515 CONFIG_AUTOBOOT_STOP_STR
516 CONFIG_AUTOBOOT_DELAY_STR2
517 CONFIG_AUTOBOOT_STOP_STR2
518 CONFIG_ZERO_BOOTDELAY_CHECK
519 CONFIG_RESET_TO_RETRY
523 Only needed when CONFIG_BOOTDELAY is enabled;
524 define a command string that is automatically executed
525 when no character is read on the console interface
526 within "Boot Delay" after reset.
529 This can be used to pass arguments to the bootm
530 command. The value of CONFIG_BOOTARGS goes into the
531 environment value "bootargs".
533 CONFIG_RAMBOOT and CONFIG_NFSBOOT
534 The value of these goes into the environment as
535 "ramboot" and "nfsboot" respectively, and can be used
536 as a convenience, when switching between booting from
542 When this option is #defined, the existence of the
543 environment variable "preboot" will be checked
544 immediately before starting the CONFIG_BOOTDELAY
545 countdown and/or running the auto-boot command resp.
546 entering interactive mode.
548 This feature is especially useful when "preboot" is
549 automatically generated or modified. For an example
550 see the LWMON board specific code: here "preboot" is
551 modified when the user holds down a certain
552 combination of keys on the (special) keyboard when
555 - Serial Download Echo Mode:
557 If defined to 1, all characters received during a
558 serial download (using the "loads" command) are
559 echoed back. This might be needed by some terminal
560 emulations (like "cu"), but may as well just take
561 time on others. This setting #define's the initial
562 value of the "loads_echo" environment variable.
564 - Kgdb Serial Baudrate: (if CFG_CMD_KGDB is defined)
566 Select one of the baudrates listed in
567 CFG_BAUDRATE_TABLE, see below.
571 Most monitor functions can be selected (or
572 de-selected) by adjusting the definition of
573 CONFIG_COMMANDS; to select individual functions,
574 #define CONFIG_COMMANDS by "OR"ing any of the
577 #define enables commands:
578 -------------------------
579 CFG_CMD_ASKENV * ask for env variable
580 CFG_CMD_AUTOSCRIPT Autoscript Support
582 CFG_CMD_BEDBUG * Include BedBug Debugger
583 CFG_CMD_BMP * BMP support
584 CFG_CMD_BSP * Board specific commands
586 CFG_CMD_CACHE * icache, dcache
587 CFG_CMD_CONSOLE coninfo
588 CFG_CMD_DATE * support for RTC, date/time...
589 CFG_CMD_DHCP * DHCP support
590 CFG_CMD_DIAG * Diagnostics
591 CFG_CMD_DOC * Disk-On-Chip Support
592 CFG_CMD_DTT * Digital Therm and Thermostat
593 CFG_CMD_ECHO * echo arguments
594 CFG_CMD_EEPROM * EEPROM read/write support
595 CFG_CMD_ELF * bootelf, bootvx
597 CFG_CMD_FDC * Floppy Disk Support
598 CFG_CMD_FAT * FAT partition support
599 CFG_CMD_FDOS * Dos diskette Support
600 CFG_CMD_FLASH flinfo, erase, protect
601 CFG_CMD_FPGA FPGA device initialization support
602 CFG_CMD_HWFLOW * RTS/CTS hw flow control
603 CFG_CMD_I2C * I2C serial bus support
604 CFG_CMD_IDE * IDE harddisk support
606 CFG_CMD_IMLS List all found images
607 CFG_CMD_IMMAP * IMMR dump support
608 CFG_CMD_IRQ * irqinfo
609 CFG_CMD_ITEST Integer/string test of 2 values
610 CFG_CMD_JFFS2 * JFFS2 Support
614 CFG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base,
616 CFG_CMD_MISC Misc functions like sleep etc
617 CFG_CMD_MMC * MMC memory mapped support
618 CFG_CMD_MII * MII utility commands
619 CFG_CMD_NAND * NAND support
620 CFG_CMD_NET bootp, tftpboot, rarpboot
621 CFG_CMD_PCI * pciinfo
622 CFG_CMD_PCMCIA * PCMCIA support
623 CFG_CMD_PING * send ICMP ECHO_REQUEST to network host
624 CFG_CMD_PORTIO * Port I/O
625 CFG_CMD_REGINFO * Register dump
626 CFG_CMD_RUN run command in env variable
627 CFG_CMD_SAVES * save S record dump
628 CFG_CMD_SCSI * SCSI Support
629 CFG_CMD_SDRAM * print SDRAM configuration information
630 (requires CFG_CMD_I2C)
631 CFG_CMD_SETGETDCR Support for DCR Register access (4xx only)
632 CFG_CMD_SPI * SPI serial bus support
633 CFG_CMD_USB * USB support
634 CFG_CMD_VFD * VFD support (TRAB)
635 CFG_CMD_BSP * Board SPecific functions
636 CFG_CMD_CDP * Cisco Discover Protocol support
637 -----------------------------------------------
640 CONFIG_CMD_DFL Default configuration; at the moment
641 this is includes all commands, except
642 the ones marked with "*" in the list
645 If you don't define CONFIG_COMMANDS it defaults to
646 CONFIG_CMD_DFL in include/cmd_confdefs.h. A board can
647 override the default settings in the respective
650 EXAMPLE: If you want all functions except of network
651 support you can write:
653 #define CONFIG_COMMANDS (CFG_CMD_ALL & ~CFG_CMD_NET)
656 Note: Don't enable the "icache" and "dcache" commands
657 (configuration option CFG_CMD_CACHE) unless you know
658 what you (and your U-Boot users) are doing. Data
659 cache cannot be enabled on systems like the 8xx or
660 8260 (where accesses to the IMMR region must be
661 uncached), and it cannot be disabled on all other
662 systems where we (mis-) use the data cache to hold an
663 initial stack and some data.
666 XXX - this list needs to get updated!
670 If this variable is defined, it enables watchdog
671 support. There must be support in the platform specific
672 code for a watchdog. For the 8xx and 8260 CPUs, the
673 SIU Watchdog feature is enabled in the SYPCR
677 CONFIG_VERSION_VARIABLE
678 If this variable is defined, an environment variable
679 named "ver" is created by U-Boot showing the U-Boot
680 version as printed by the "version" command.
681 This variable is readonly.
685 When CFG_CMD_DATE is selected, the type of the RTC
686 has to be selected, too. Define exactly one of the
689 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx
690 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC
691 CONFIG_RTC_MC146818 - use MC146818 RTC
692 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC
693 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC
694 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC
695 CONFIG_RTC_DS164x - use Dallas DS164x RTC
696 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC
698 Note that if the RTC uses I2C, then the I2C interface
699 must also be configured. See I2C Support, below.
703 When CONFIG_TIMESTAMP is selected, the timestamp
704 (date and time) of an image is printed by image
705 commands like bootm or iminfo. This option is
706 automatically enabled when you select CFG_CMD_DATE .
709 CONFIG_MAC_PARTITION and/or CONFIG_DOS_PARTITION
710 and/or CONFIG_ISO_PARTITION
712 If IDE or SCSI support is enabled (CFG_CMD_IDE or
713 CFG_CMD_SCSI) you must configure support for at least
714 one partition type as well.
717 CONFIG_IDE_RESET_ROUTINE - this is defined in several
718 board configurations files but used nowhere!
720 CONFIG_IDE_RESET - is this is defined, IDE Reset will
721 be performed by calling the function
722 ide_set_reset(int reset)
723 which has to be defined in a board specific file
728 Set this to enable ATAPI support.
733 Set this to enable support for disks larger than 137GB
734 Also look at CFG_64BIT_LBA ,CFG_64BIT_VSPRINTF and CFG_64BIT_STRTOUL
735 Whithout these , LBA48 support uses 32bit variables and will 'only'
736 support disks up to 2.1TB.
739 When enabled, makes the IDE subsystem use 64bit sector addresses.
743 At the moment only there is only support for the
744 SYM53C8XX SCSI controller; define
745 CONFIG_SCSI_SYM53C8XX to enable it.
747 CFG_SCSI_MAX_LUN [8], CFG_SCSI_MAX_SCSI_ID [7] and
748 CFG_SCSI_MAX_DEVICE [CFG_SCSI_MAX_SCSI_ID *
749 CFG_SCSI_MAX_LUN] can be adjusted to define the
750 maximum numbers of LUNs, SCSI ID's and target
752 CFG_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz)
754 - NETWORK Support (PCI):
756 Support for Intel 8254x gigabit chips.
759 Support for Intel 82557/82559/82559ER chips.
760 Optional CONFIG_EEPRO100_SROM_WRITE enables eeprom
761 write routine for first time initialisation.
764 Support for Digital 2114x chips.
765 Optional CONFIG_TULIP_SELECT_MEDIA for board specific
766 modem chip initialisation (KS8761/QS6611).
769 Support for National dp83815 chips.
772 Support for National dp8382[01] gigabit chips.
774 - NETWORK Support (other):
776 CONFIG_DRIVER_LAN91C96
777 Support for SMSC's LAN91C96 chips.
780 Define this to hold the physical address
781 of the LAN91C96's I/O space
783 CONFIG_LAN91C96_USE_32_BIT
784 Define this to enable 32 bit addressing
786 CONFIG_DRIVER_SMC91111
787 Support for SMSC's LAN91C111 chip
790 Define this to hold the physical address
791 of the device (I/O space)
793 CONFIG_SMC_USE_32_BIT
794 Define this if data bus is 32 bits
796 CONFIG_SMC_USE_IOFUNCS
797 Define this to use i/o functions instead of macros
798 (some hardware wont work with macros)
801 At the moment only the UHCI host controller is
802 supported (PIP405, MIP405, MPC5200); define
803 CONFIG_USB_UHCI to enable it.
804 define CONFIG_USB_KEYBOARD to enable the USB Keyboard
805 and define CONFIG_USB_STORAGE to enable the USB
808 Supported are USB Keyboards and USB Floppy drives
810 MPC5200 USB requires additional defines:
812 for 528 MHz Clock: 0x0001bbbb
814 for differential drivers: 0x00001000
815 for single ended drivers: 0x00005000
819 The MMC controller on the Intel PXA is supported. To
820 enable this define CONFIG_MMC. The MMC can be
821 accessed from the boot prompt by mapping the device
822 to physical memory similar to flash. Command line is
823 enabled with CFG_CMD_MMC. The MMC driver also works with
824 the FAT fs. This is enabled with CFG_CMD_FAT.
826 - Journaling Flash filesystem support:
827 CONFIG_JFFS2_NAND, CONFIG_JFFS2_NAND_OFF, CONFIG_JFFS2_NAND_SIZE,
828 CONFIG_JFFS2_NAND_DEV
829 Define these for a default partition on a NAND device
831 CFG_JFFS2_FIRST_SECTOR,
832 CFG_JFFS2_FIRST_BANK, CFG_JFFS2_NUM_BANKS
833 Define these for a default partition on a NOR device
836 Define this to create an own partition. You have to provide a
837 function struct part_info* jffs2_part_info(int part_num)
839 If you define only one JFFS2 partition you may also want to
840 #define CFG_JFFS_SINGLE_PART 1
841 to disable the command chpart. This is the default when you
842 have not defined a custom partition
847 Define this to enable standard (PC-Style) keyboard
851 Standard PC keyboard driver with US (is default) and
852 GERMAN key layout (switch via environment 'keymap=de') support.
853 Export function i8042_kbd_init, i8042_tstc and i8042_getc
854 for cfb_console. Supports cursor blinking.
859 Define this to enable video support (for output to
864 Enable Chips & Technologies 69000 Video chip
866 CONFIG_VIDEO_SMI_LYNXEM
867 Enable Silicon Motion SMI 712/710/810 Video chip. The
868 video output is selected via environment 'videoout'
869 (1 = LCD and 2 = CRT). If videoout is undefined, CRT is
872 For the CT69000 and SMI_LYNXEM drivers, videomode is
873 selected via environment 'videomode'. Two diferent ways
875 - "videomode=num" 'num' is a standard LiLo mode numbers.
876 Following standard modes are supported (* is default):
878 Colors 640x480 800x600 1024x768 1152x864 1280x1024
879 -------------+---------------------------------------------
880 8 bits | 0x301* 0x303 0x305 0x161 0x307
881 15 bits | 0x310 0x313 0x316 0x162 0x319
882 16 bits | 0x311 0x314 0x317 0x163 0x31A
883 24 bits | 0x312 0x315 0x318 ? 0x31B
884 -------------+---------------------------------------------
885 (i.e. setenv videomode 317; saveenv; reset;)
887 - "videomode=bootargs" all the video parameters are parsed
888 from the bootargs. (See drivers/videomodes.c)
891 CONFIG_VIDEO_SED13806
892 Enable Epson SED13806 driver. This driver supports 8bpp
893 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP
894 or CONFIG_VIDEO_SED13806_16BPP
899 Define this to enable a custom keyboard support.
900 This simply calls drv_keyboard_init() which must be
901 defined in your board-specific files.
902 The only board using this so far is RBC823.
904 - LCD Support: CONFIG_LCD
906 Define this to enable LCD support (for output to LCD
907 display); also select one of the supported displays
908 by defining one of these:
910 CONFIG_NEC_NL6448AC33:
912 NEC NL6448AC33-18. Active, color, single scan.
914 CONFIG_NEC_NL6448BC20
916 NEC NL6448BC20-08. 6.5", 640x480.
917 Active, color, single scan.
919 CONFIG_NEC_NL6448BC33_54
921 NEC NL6448BC33-54. 10.4", 640x480.
922 Active, color, single scan.
926 Sharp 320x240. Active, color, single scan.
927 It isn't 16x9, and I am not sure what it is.
929 CONFIG_SHARP_LQ64D341
931 Sharp LQ64D341 display, 640x480.
932 Active, color, single scan.
936 HLD1045 display, 640x480.
937 Active, color, single scan.
941 Optrex CBL50840-2 NF-FW 99 22 M5
943 Hitachi LMG6912RPFC-00T
947 320x240. Black & white.
949 Normally display is black on white background; define
950 CFG_WHITE_ON_BLACK to get it inverted.
952 - Splash Screen Support: CONFIG_SPLASH_SCREEN
954 If this option is set, the environment is checked for
955 a variable "splashimage". If found, the usual display
956 of logo, copyright and system information on the LCD
957 is suppressed and the BMP image at the address
958 specified in "splashimage" is loaded instead. The
959 console is redirected to the "nulldev", too. This
960 allows for a "silent" boot where a splash screen is
961 loaded very quickly after power-on.
963 - Compression support:
966 If this option is set, support for bzip2 compressed
967 images is included. If not, only uncompressed and gzip
968 compressed images are supported.
970 NOTE: the bzip2 algorithm requires a lot of RAM, so
971 the malloc area (as defined by CFG_MALLOC_LEN) should
977 The address of PHY on MII bus.
979 CONFIG_PHY_CLOCK_FREQ (ppc4xx)
981 The clock frequency of the MII bus
985 If this option is set, support for speed/duplex
986 detection of Gigabit PHY is included.
988 CONFIG_PHY_RESET_DELAY
990 Some PHY like Intel LXT971A need extra delay after
991 reset before any MII register access is possible.
992 For such PHY, set this option to the usec delay
993 required. (minimum 300usec for LXT971A)
995 CONFIG_PHY_CMD_DELAY (ppc4xx)
997 Some PHY like Intel LXT971A need extra delay after
998 command issued before MII status register can be read
1005 Define a default value for ethernet address to use
1006 for the respective ethernet interface, in case this
1007 is not determined automatically.
1012 Define a default value for the IP address to use for
1013 the default ethernet interface, in case this is not
1014 determined through e.g. bootp.
1016 - Server IP address:
1019 Defines a default value for theIP address of a TFTP
1020 server to contact when using the "tftboot" command.
1022 - BOOTP Recovery Mode:
1023 CONFIG_BOOTP_RANDOM_DELAY
1025 If you have many targets in a network that try to
1026 boot using BOOTP, you may want to avoid that all
1027 systems send out BOOTP requests at precisely the same
1028 moment (which would happen for instance at recovery
1029 from a power failure, when all systems will try to
1030 boot, thus flooding the BOOTP server. Defining
1031 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
1032 inserted before sending out BOOTP requests. The
1033 following delays are insterted then:
1035 1st BOOTP request: delay 0 ... 1 sec
1036 2nd BOOTP request: delay 0 ... 2 sec
1037 3rd BOOTP request: delay 0 ... 4 sec
1039 BOOTP requests: delay 0 ... 8 sec
1041 - DHCP Advanced Options:
1044 You can fine tune the DHCP functionality by adding
1045 these flags to the CONFIG_BOOTP_MASK define:
1047 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS
1048 serverip from a DHCP server, it is possible that more
1049 than one DNS serverip is offered to the client.
1050 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS
1051 serverip will be stored in the additional environment
1052 variable "dnsip2". The first DNS serverip is always
1053 stored in the variable "dnsip", when CONFIG_BOOTP_DNS
1054 is added to the CONFIG_BOOTP_MASK.
1056 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable
1057 to do a dynamic update of a DNS server. To do this, they
1058 need the hostname of the DHCP requester.
1059 If CONFIG_BOOP_SEND_HOSTNAME is added to the
1060 CONFIG_BOOTP_MASK, the content of the "hostname"
1061 environment variable is passed as option 12 to
1065 CONFIG_CDP_DEVICE_ID
1067 The device id used in CDP trigger frames.
1069 CONFIG_CDP_DEVICE_ID_PREFIX
1071 A two character string which is prefixed to the MAC address
1076 A printf format string which contains the ascii name of
1077 the port. Normally is set to "eth%d" which sets
1078 eth0 for the first ethernet, eth1 for the second etc.
1080 CONFIG_CDP_CAPABILITIES
1082 A 32bit integer which indicates the device capabilities;
1083 0x00000010 for a normal host which does not forwards.
1087 An ascii string containing the version of the software.
1091 An ascii string containing the name of the platform.
1095 A 32bit integer sent on the trigger.
1097 CONFIG_CDP_POWER_CONSUMPTION
1099 A 16bit integer containing the power consumption of the
1100 device in .1 of milliwatts.
1102 CONFIG_CDP_APPLIANCE_VLAN_TYPE
1104 A byte containing the id of the VLAN.
1106 - Status LED: CONFIG_STATUS_LED
1108 Several configurations allow to display the current
1109 status using a LED. For instance, the LED will blink
1110 fast while running U-Boot code, stop blinking as
1111 soon as a reply to a BOOTP request was received, and
1112 start blinking slow once the Linux kernel is running
1113 (supported by a status LED driver in the Linux
1114 kernel). Defining CONFIG_STATUS_LED enables this
1117 - CAN Support: CONFIG_CAN_DRIVER
1119 Defining CONFIG_CAN_DRIVER enables CAN driver support
1120 on those systems that support this (optional)
1121 feature, like the TQM8xxL modules.
1123 - I2C Support: CONFIG_HARD_I2C | CONFIG_SOFT_I2C
1125 These enable I2C serial bus commands. Defining either of
1126 (but not both of) CONFIG_HARD_I2C or CONFIG_SOFT_I2C will
1127 include the appropriate I2C driver for the selected cpu.
1129 This will allow you to use i2c commands at the u-boot
1130 command line (as long as you set CFG_CMD_I2C in
1131 CONFIG_COMMANDS) and communicate with i2c based realtime
1132 clock chips. See common/cmd_i2c.c for a description of the
1133 command line interface.
1135 CONFIG_HARD_I2C selects the CPM hardware driver for I2C.
1137 CONFIG_SOFT_I2C configures u-boot to use a software (aka
1138 bit-banging) driver instead of CPM or similar hardware
1141 There are several other quantities that must also be
1142 defined when you define CONFIG_HARD_I2C or CONFIG_SOFT_I2C.
1144 In both cases you will need to define CFG_I2C_SPEED
1145 to be the frequency (in Hz) at which you wish your i2c bus
1146 to run and CFG_I2C_SLAVE to be the address of this node (ie
1147 the cpu's i2c node address).
1149 Now, the u-boot i2c code for the mpc8xx (cpu/mpc8xx/i2c.c)
1150 sets the cpu up as a master node and so its address should
1151 therefore be cleared to 0 (See, eg, MPC823e User's Manual
1152 p.16-473). So, set CFG_I2C_SLAVE to 0.
1154 That's all that's required for CONFIG_HARD_I2C.
1156 If you use the software i2c interface (CONFIG_SOFT_I2C)
1157 then the following macros need to be defined (examples are
1158 from include/configs/lwmon.h):
1162 (Optional). Any commands necessary to enable the I2C
1163 controller or configure ports.
1165 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
1169 (Only for MPC8260 CPU). The I/O port to use (the code
1170 assumes both bits are on the same port). Valid values
1171 are 0..3 for ports A..D.
1175 The code necessary to make the I2C data line active
1176 (driven). If the data line is open collector, this
1179 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
1183 The code necessary to make the I2C data line tri-stated
1184 (inactive). If the data line is open collector, this
1187 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
1191 Code that returns TRUE if the I2C data line is high,
1194 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
1198 If <bit> is TRUE, sets the I2C data line high. If it
1199 is FALSE, it clears it (low).
1201 eg: #define I2C_SDA(bit) \
1202 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
1203 else immr->im_cpm.cp_pbdat &= ~PB_SDA
1207 If <bit> is TRUE, sets the I2C clock line high. If it
1208 is FALSE, it clears it (low).
1210 eg: #define I2C_SCL(bit) \
1211 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
1212 else immr->im_cpm.cp_pbdat &= ~PB_SCL
1216 This delay is invoked four times per clock cycle so this
1217 controls the rate of data transfer. The data rate thus
1218 is 1 / (I2C_DELAY * 4). Often defined to be something
1221 #define I2C_DELAY udelay(2)
1225 When a board is reset during an i2c bus transfer
1226 chips might think that the current transfer is still
1227 in progress. On some boards it is possible to access
1228 the i2c SCLK line directly, either by using the
1229 processor pin as a GPIO or by having a second pin
1230 connected to the bus. If this option is defined a
1231 custom i2c_init_board() routine in boards/xxx/board.c
1232 is run early in the boot sequence.
1234 CONFIG_I2CFAST (PPC405GP|PPC405EP only)
1236 This option enables configuration of bi_iic_fast[] flags
1237 in u-boot bd_info structure based on u-boot environment
1238 variable "i2cfast". (see also i2cfast)
1240 - SPI Support: CONFIG_SPI
1242 Enables SPI driver (so far only tested with
1243 SPI EEPROM, also an instance works with Crystal A/D and
1244 D/As on the SACSng board)
1248 Enables extended (16-bit) SPI EEPROM addressing.
1249 (symmetrical to CONFIG_I2C_X)
1253 Enables a software (bit-bang) SPI driver rather than
1254 using hardware support. This is a general purpose
1255 driver that only requires three general I/O port pins
1256 (two outputs, one input) to function. If this is
1257 defined, the board configuration must define several
1258 SPI configuration items (port pins to use, etc). For
1259 an example, see include/configs/sacsng.h.
1261 - FPGA Support: CONFIG_FPGA_COUNT
1263 Specify the number of FPGA devices to support.
1267 Used to specify the types of FPGA devices. For example,
1268 #define CONFIG_FPGA CFG_XILINX_VIRTEX2
1270 CFG_FPGA_PROG_FEEDBACK
1272 Enable printing of hash marks during FPGA configuration.
1276 Enable checks on FPGA configuration interface busy
1277 status by the configuration function. This option
1278 will require a board or device specific function to
1283 If defined, a function that provides delays in the FPGA
1284 configuration driver.
1286 CFG_FPGA_CHECK_CTRLC
1287 Allow Control-C to interrupt FPGA configuration
1289 CFG_FPGA_CHECK_ERROR
1291 Check for configuration errors during FPGA bitfile
1292 loading. For example, abort during Virtex II
1293 configuration if the INIT_B line goes low (which
1294 indicated a CRC error).
1298 Maximum time to wait for the INIT_B line to deassert
1299 after PROB_B has been deasserted during a Virtex II
1300 FPGA configuration sequence. The default time is 500
1305 Maximum time to wait for BUSY to deassert during
1306 Virtex II FPGA configuration. The default is 5 mS.
1308 CFG_FPGA_WAIT_CONFIG
1310 Time to wait after FPGA configuration. The default is
1313 - Configuration Management:
1316 If defined, this string will be added to the U-Boot
1317 version information (U_BOOT_VERSION)
1319 - Vendor Parameter Protection:
1321 U-Boot considers the values of the environment
1322 variables "serial#" (Board Serial Number) and
1323 "ethaddr" (Ethernet Address) to be parameters that
1324 are set once by the board vendor / manufacturer, and
1325 protects these variables from casual modification by
1326 the user. Once set, these variables are read-only,
1327 and write or delete attempts are rejected. You can
1328 change this behviour:
1330 If CONFIG_ENV_OVERWRITE is #defined in your config
1331 file, the write protection for vendor parameters is
1332 completely disabled. Anybody can change or delete
1335 Alternatively, if you #define _both_ CONFIG_ETHADDR
1336 _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
1337 ethernet address is installed in the environment,
1338 which can be changed exactly ONCE by the user. [The
1339 serial# is unaffected by this, i. e. it remains
1345 Define this variable to enable the reservation of
1346 "protected RAM", i. e. RAM which is not overwritten
1347 by U-Boot. Define CONFIG_PRAM to hold the number of
1348 kB you want to reserve for pRAM. You can overwrite
1349 this default value by defining an environment
1350 variable "pram" to the number of kB you want to
1351 reserve. Note that the board info structure will
1352 still show the full amount of RAM. If pRAM is
1353 reserved, a new environment variable "mem" will
1354 automatically be defined to hold the amount of
1355 remaining RAM in a form that can be passed as boot
1356 argument to Linux, for instance like that:
1358 setenv bootargs ... mem=\$(mem)
1361 This way you can tell Linux not to use this memory,
1362 either, which results in a memory region that will
1363 not be affected by reboots.
1365 *WARNING* If your board configuration uses automatic
1366 detection of the RAM size, you must make sure that
1367 this memory test is non-destructive. So far, the
1368 following board configurations are known to be
1371 ETX094, IVMS8, IVML24, SPD8xx, TQM8xxL,
1372 HERMES, IP860, RPXlite, LWMON, LANTEC,
1373 PCU_E, FLAGADM, TQM8260
1378 Define this variable to stop the system in case of a
1379 fatal error, so that you have to reset it manually.
1380 This is probably NOT a good idea for an embedded
1381 system where you want to system to reboot
1382 automatically as fast as possible, but it may be
1383 useful during development since you can try to debug
1384 the conditions that lead to the situation.
1386 CONFIG_NET_RETRY_COUNT
1388 This variable defines the number of retries for
1389 network operations like ARP, RARP, TFTP, or BOOTP
1390 before giving up the operation. If not defined, a
1391 default value of 5 is used.
1393 - Command Interpreter:
1396 Enable auto completion of commands using TAB.
1400 Define this variable to enable the "hush" shell (from
1401 Busybox) as command line interpreter, thus enabling
1402 powerful command line syntax like
1403 if...then...else...fi conditionals or `&&' and '||'
1404 constructs ("shell scripts").
1406 If undefined, you get the old, much simpler behaviour
1407 with a somewhat smaller memory footprint.
1412 This defines the secondary prompt string, which is
1413 printed when the command interpreter needs more input
1414 to complete a command. Usually "> ".
1418 In the current implementation, the local variables
1419 space and global environment variables space are
1420 separated. Local variables are those you define by
1421 simply typing `name=value'. To access a local
1422 variable later on, you have write `$name' or
1423 `${name}'; to execute the contents of a variable
1424 directly type `$name' at the command prompt.
1426 Global environment variables are those you use
1427 setenv/printenv to work with. To run a command stored
1428 in such a variable, you need to use the run command,
1429 and you must not use the '$' sign to access them.
1431 To store commands and special characters in a
1432 variable, please use double quotation marks
1433 surrounding the whole text of the variable, instead
1434 of the backslashes before semicolons and special
1437 - Default Environment:
1438 CONFIG_EXTRA_ENV_SETTINGS
1440 Define this to contain any number of null terminated
1441 strings (variable = value pairs) that will be part of
1442 the default environment compiled into the boot image.
1444 For example, place something like this in your
1445 board's config file:
1447 #define CONFIG_EXTRA_ENV_SETTINGS \
1451 Warning: This method is based on knowledge about the
1452 internal format how the environment is stored by the
1453 U-Boot code. This is NOT an official, exported
1454 interface! Although it is unlikely that this format
1455 will change soon, there is no guarantee either.
1456 You better know what you are doing here.
1458 Note: overly (ab)use of the default environment is
1459 discouraged. Make sure to check other ways to preset
1460 the environment like the autoscript function or the
1463 - DataFlash Support:
1464 CONFIG_HAS_DATAFLASH
1466 Defining this option enables DataFlash features and
1467 allows to read/write in Dataflash via the standard
1470 - SystemACE Support:
1473 Adding this option adds support for Xilinx SystemACE
1474 chips attached via some sort of local bus. The address
1475 of the chip must alsh be defined in the
1476 CFG_SYSTEMACE_BASE macro. For example:
1478 #define CONFIG_SYSTEMACE
1479 #define CFG_SYSTEMACE_BASE 0xf0000000
1481 When SystemACE support is added, the "ace" device type
1482 becomes available to the fat commands, i.e. fatls.
1484 - Show boot progress:
1485 CONFIG_SHOW_BOOT_PROGRESS
1487 Defining this option allows to add some board-
1488 specific code (calling a user-provided function
1489 "show_boot_progress(int)") that enables you to show
1490 the system's boot progress on some display (for
1491 example, some LED's) on your board. At the moment,
1492 the following checkpoints are implemented:
1495 1 common/cmd_bootm.c before attempting to boot an image
1496 -1 common/cmd_bootm.c Image header has bad magic number
1497 2 common/cmd_bootm.c Image header has correct magic number
1498 -2 common/cmd_bootm.c Image header has bad checksum
1499 3 common/cmd_bootm.c Image header has correct checksum
1500 -3 common/cmd_bootm.c Image data has bad checksum
1501 4 common/cmd_bootm.c Image data has correct checksum
1502 -4 common/cmd_bootm.c Image is for unsupported architecture
1503 5 common/cmd_bootm.c Architecture check OK
1504 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi, standalone)
1505 6 common/cmd_bootm.c Image Type check OK
1506 -6 common/cmd_bootm.c gunzip uncompression error
1507 -7 common/cmd_bootm.c Unimplemented compression type
1508 7 common/cmd_bootm.c Uncompression OK
1509 -8 common/cmd_bootm.c Wrong Image Type (not kernel, multi, standalone)
1510 8 common/cmd_bootm.c Image Type check OK
1511 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX)
1512 9 common/cmd_bootm.c Start initial ramdisk verification
1513 -10 common/cmd_bootm.c Ramdisk header has bad magic number
1514 -11 common/cmd_bootm.c Ramdisk header has bad checksum
1515 10 common/cmd_bootm.c Ramdisk header is OK
1516 -12 common/cmd_bootm.c Ramdisk data has bad checksum
1517 11 common/cmd_bootm.c Ramdisk data has correct checksum
1518 12 common/cmd_bootm.c Ramdisk verification complete, start loading
1519 -13 common/cmd_bootm.c Wrong Image Type (not PPC Linux Ramdisk)
1520 13 common/cmd_bootm.c Start multifile image verification
1521 14 common/cmd_bootm.c No initial ramdisk, no multifile, continue.
1522 15 common/cmd_bootm.c All preparation done, transferring control to OS
1524 -30 lib_ppc/board.c Fatal error, hang the system
1525 -31 post/post.c POST test failed, detected by post_output_backlog()
1526 -32 post/post.c POST test failed, detected by post_run_single()
1528 -1 common/cmd_doc.c Bad usage of "doc" command
1529 -1 common/cmd_doc.c No boot device
1530 -1 common/cmd_doc.c Unknown Chip ID on boot device
1531 -1 common/cmd_doc.c Read Error on boot device
1532 -1 common/cmd_doc.c Image header has bad magic number
1534 -1 common/cmd_ide.c Bad usage of "ide" command
1535 -1 common/cmd_ide.c No boot device
1536 -1 common/cmd_ide.c Unknown boot device
1537 -1 common/cmd_ide.c Unknown partition table
1538 -1 common/cmd_ide.c Invalid partition type
1539 -1 common/cmd_ide.c Read Error on boot device
1540 -1 common/cmd_ide.c Image header has bad magic number
1542 -1 common/cmd_nand.c Bad usage of "nand" command
1543 -1 common/cmd_nand.c No boot device
1544 -1 common/cmd_nand.c Unknown Chip ID on boot device
1545 -1 common/cmd_nand.c Read Error on boot device
1546 -1 common/cmd_nand.c Image header has bad magic number
1548 -1 common/env_common.c Environment has a bad CRC, using default
1554 [so far only for SMDK2400 and TRAB boards]
1556 - Modem support endable:
1557 CONFIG_MODEM_SUPPORT
1559 - RTS/CTS Flow control enable:
1562 - Modem debug support:
1563 CONFIG_MODEM_SUPPORT_DEBUG
1565 Enables debugging stuff (char screen[1024], dbg())
1566 for modem support. Useful only with BDI2000.
1568 - Interrupt support (PPC):
1570 There are common interrupt_init() and timer_interrupt()
1571 for all PPC archs. interrupt_init() calls interrupt_init_cpu()
1572 for cpu specific initialization. interrupt_init_cpu()
1573 should set decrementer_count to appropriate value. If
1574 cpu resets decrementer automatically after interrupt
1575 (ppc4xx) it should set decrementer_count to zero.
1576 timer_interrupt() calls timer_interrupt_cpu() for cpu
1577 specific handling. If board has watchdog / status_led
1578 / other_activity_monitor it works automatically from
1579 general timer_interrupt().
1583 In the target system modem support is enabled when a
1584 specific key (key combination) is pressed during
1585 power-on. Otherwise U-Boot will boot normally
1586 (autoboot). The key_pressed() fuction is called from
1587 board_init(). Currently key_pressed() is a dummy
1588 function, returning 1 and thus enabling modem
1591 If there are no modem init strings in the
1592 environment, U-Boot proceed to autoboot; the
1593 previous output (banner, info printfs) will be
1596 See also: doc/README.Modem
1599 Configuration Settings:
1600 -----------------------
1602 - CFG_LONGHELP: Defined when you want long help messages included;
1603 undefine this when you're short of memory.
1605 - CFG_PROMPT: This is what U-Boot prints on the console to
1606 prompt for user input.
1608 - CFG_CBSIZE: Buffer size for input from the Console
1610 - CFG_PBSIZE: Buffer size for Console output
1612 - CFG_MAXARGS: max. Number of arguments accepted for monitor commands
1614 - CFG_BARGSIZE: Buffer size for Boot Arguments which are passed to
1615 the application (usually a Linux kernel) when it is
1618 - CFG_BAUDRATE_TABLE:
1619 List of legal baudrate settings for this board.
1621 - CFG_CONSOLE_INFO_QUIET
1622 Suppress display of console information at boot.
1624 - CFG_CONSOLE_IS_IN_ENV
1625 If the board specific function
1626 extern int overwrite_console (void);
1627 returns 1, the stdin, stderr and stdout are switched to the
1628 serial port, else the settings in the environment are used.
1630 - CFG_CONSOLE_OVERWRITE_ROUTINE
1631 Enable the call to overwrite_console().
1633 - CFG_CONSOLE_ENV_OVERWRITE
1634 Enable overwrite of previous console environment settings.
1636 - CFG_MEMTEST_START, CFG_MEMTEST_END:
1637 Begin and End addresses of the area used by the
1641 Enable an alternate, more extensive memory test.
1643 - CFG_MEMTEST_SCRATCH:
1644 Scratch address used by the alternate memory test
1645 You only need to set this if address zero isn't writeable
1647 - CFG_TFTP_LOADADDR:
1648 Default load address for network file downloads
1650 - CFG_LOADS_BAUD_CHANGE:
1651 Enable temporary baudrate change while serial download
1654 Physical start address of SDRAM. _Must_ be 0 here.
1657 Physical start address of Motherboard I/O (if using a
1661 Physical start address of Flash memory.
1664 Physical start address of boot monitor code (set by
1665 make config files to be same as the text base address
1666 (TEXT_BASE) used when linking) - same as
1667 CFG_FLASH_BASE when booting from flash.
1670 Size of memory reserved for monitor code, used to
1671 determine _at_compile_time_ (!) if the environment is
1672 embedded within the U-Boot image, or in a separate
1676 Size of DRAM reserved for malloc() use.
1679 Maximum size of memory mapped by the startup code of
1680 the Linux kernel; all data that must be processed by
1681 the Linux kernel (bd_info, boot arguments, eventually
1682 initrd image) must be put below this limit.
1684 - CFG_MAX_FLASH_BANKS:
1685 Max number of Flash memory banks
1687 - CFG_MAX_FLASH_SECT:
1688 Max number of sectors on a Flash chip
1690 - CFG_FLASH_ERASE_TOUT:
1691 Timeout for Flash erase operations (in ms)
1693 - CFG_FLASH_WRITE_TOUT:
1694 Timeout for Flash write operations (in ms)
1696 - CFG_FLASH_LOCK_TOUT
1697 Timeout for Flash set sector lock bit operation (in ms)
1699 - CFG_FLASH_UNLOCK_TOUT
1700 Timeout for Flash clear lock bits operation (in ms)
1702 - CFG_FLASH_PROTECTION
1703 If defined, hardware flash sectors protection is used
1704 instead of U-Boot software protection.
1706 - CFG_DIRECT_FLASH_TFTP:
1708 Enable TFTP transfers directly to flash memory;
1709 without this option such a download has to be
1710 performed in two steps: (1) download to RAM, and (2)
1711 copy from RAM to flash.
1713 The two-step approach is usually more reliable, since
1714 you can check if the download worked before you erase
1715 the flash, but in some situations (when sytem RAM is
1716 too limited to allow for a tempory copy of the
1717 downloaded image) this option may be very useful.
1720 Define if the flash driver uses extra elements in the
1721 common flash structure for storing flash geometry.
1723 - CFG_FLASH_CFI_DRIVER
1724 This option also enables the building of the cfi_flash driver
1725 in the drivers directory
1727 - CFG_RX_ETH_BUFFER:
1728 Defines the number of ethernet receive buffers. On some
1729 ethernet controllers it is recommended to set this value
1730 to 8 or even higher (EEPRO100 or 405 EMAC), since all
1731 buffers can be full shortly after enabling the interface
1732 on high ethernet traffic.
1733 Defaults to 4 if not defined.
1735 The following definitions that deal with the placement and management
1736 of environment data (variable area); in general, we support the
1737 following configurations:
1739 - CFG_ENV_IS_IN_FLASH:
1741 Define this if the environment is in flash memory.
1743 a) The environment occupies one whole flash sector, which is
1744 "embedded" in the text segment with the U-Boot code. This
1745 happens usually with "bottom boot sector" or "top boot
1746 sector" type flash chips, which have several smaller
1747 sectors at the start or the end. For instance, such a
1748 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In
1749 such a case you would place the environment in one of the
1750 4 kB sectors - with U-Boot code before and after it. With
1751 "top boot sector" type flash chips, you would put the
1752 environment in one of the last sectors, leaving a gap
1753 between U-Boot and the environment.
1757 Offset of environment data (variable area) to the
1758 beginning of flash memory; for instance, with bottom boot
1759 type flash chips the second sector can be used: the offset
1760 for this sector is given here.
1762 CFG_ENV_OFFSET is used relative to CFG_FLASH_BASE.
1766 This is just another way to specify the start address of
1767 the flash sector containing the environment (instead of
1770 - CFG_ENV_SECT_SIZE:
1772 Size of the sector containing the environment.
1775 b) Sometimes flash chips have few, equal sized, BIG sectors.
1776 In such a case you don't want to spend a whole sector for
1781 If you use this in combination with CFG_ENV_IS_IN_FLASH
1782 and CFG_ENV_SECT_SIZE, you can specify to use only a part
1783 of this flash sector for the environment. This saves
1784 memory for the RAM copy of the environment.
1786 It may also save flash memory if you decide to use this
1787 when your environment is "embedded" within U-Boot code,
1788 since then the remainder of the flash sector could be used
1789 for U-Boot code. It should be pointed out that this is
1790 STRONGLY DISCOURAGED from a robustness point of view:
1791 updating the environment in flash makes it always
1792 necessary to erase the WHOLE sector. If something goes
1793 wrong before the contents has been restored from a copy in
1794 RAM, your target system will be dead.
1796 - CFG_ENV_ADDR_REDUND
1799 These settings describe a second storage area used to hold
1800 a redundand copy of the environment data, so that there is
1801 a valid backup copy in case there is a power failure during
1802 a "saveenv" operation.
1804 BE CAREFUL! Any changes to the flash layout, and some changes to the
1805 source code will make it necessary to adapt <board>/u-boot.lds*
1809 - CFG_ENV_IS_IN_NVRAM:
1811 Define this if you have some non-volatile memory device
1812 (NVRAM, battery buffered SRAM) which you want to use for the
1818 These two #defines are used to determin the memory area you
1819 want to use for environment. It is assumed that this memory
1820 can just be read and written to, without any special
1823 BE CAREFUL! The first access to the environment happens quite early
1824 in U-Boot initalization (when we try to get the setting of for the
1825 console baudrate). You *MUST* have mappend your NVRAM area then, or
1828 Please note that even with NVRAM we still use a copy of the
1829 environment in RAM: we could work on NVRAM directly, but we want to
1830 keep settings there always unmodified except somebody uses "saveenv"
1831 to save the current settings.
1834 - CFG_ENV_IS_IN_EEPROM:
1836 Use this if you have an EEPROM or similar serial access
1837 device and a driver for it.
1842 These two #defines specify the offset and size of the
1843 environment area within the total memory of your EEPROM.
1845 - CFG_I2C_EEPROM_ADDR:
1846 If defined, specified the chip address of the EEPROM device.
1847 The default address is zero.
1849 - CFG_EEPROM_PAGE_WRITE_BITS:
1850 If defined, the number of bits used to address bytes in a
1851 single page in the EEPROM device. A 64 byte page, for example
1852 would require six bits.
1854 - CFG_EEPROM_PAGE_WRITE_DELAY_MS:
1855 If defined, the number of milliseconds to delay between
1856 page writes. The default is zero milliseconds.
1858 - CFG_I2C_EEPROM_ADDR_LEN:
1859 The length in bytes of the EEPROM memory array address. Note
1860 that this is NOT the chip address length!
1862 - CFG_I2C_EEPROM_ADDR_OVERFLOW:
1863 EEPROM chips that implement "address overflow" are ones
1864 like Catalyst 24WC04/08/16 which has 9/10/11 bits of
1865 address and the extra bits end up in the "chip address" bit
1866 slots. This makes a 24WC08 (1Kbyte) chip look like four 256
1869 Note that we consider the length of the address field to
1870 still be one byte because the extra address bits are hidden
1871 in the chip address.
1874 The size in bytes of the EEPROM device.
1877 - CFG_ENV_IS_IN_DATAFLASH:
1879 Define this if you have a DataFlash memory device which you
1880 want to use for the environment.
1886 These three #defines specify the offset and size of the
1887 environment area within the total memory of your DataFlash placed
1888 at the specified address.
1890 - CFG_ENV_IS_IN_NAND:
1892 Define this if you have a NAND device which you want to use
1893 for the environment.
1898 These two #defines specify the offset and size of the environment
1899 area within the first NAND device.
1901 - CFG_SPI_INIT_OFFSET
1903 Defines offset to the initial SPI buffer area in DPRAM. The
1904 area is used at an early stage (ROM part) if the environment
1905 is configured to reside in the SPI EEPROM: We need a 520 byte
1906 scratch DPRAM area. It is used between the two initialization
1907 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems
1908 to be a good choice since it makes it far enough from the
1909 start of the data area as well as from the stack pointer.
1911 Please note that the environment is read-only as long as the monitor
1912 has been relocated to RAM and a RAM copy of the environment has been
1913 created; also, when using EEPROM you will have to use getenv_r()
1914 until then to read environment variables.
1916 The environment is protected by a CRC32 checksum. Before the monitor
1917 is relocated into RAM, as a result of a bad CRC you will be working
1918 with the compiled-in default environment - *silently*!!! [This is
1919 necessary, because the first environment variable we need is the
1920 "baudrate" setting for the console - if we have a bad CRC, we don't
1921 have any device yet where we could complain.]
1923 Note: once the monitor has been relocated, then it will complain if
1924 the default environment is used; a new CRC is computed as soon as you
1925 use the "saveenv" command to store a valid environment.
1927 - CFG_FAULT_ECHO_LINK_DOWN:
1928 Echo the inverted Ethernet link state to the fault LED.
1930 Note: If this option is active, then CFG_FAULT_MII_ADDR
1931 also needs to be defined.
1933 - CFG_FAULT_MII_ADDR:
1934 MII address of the PHY to check for the Ethernet link state.
1936 - CFG_64BIT_VSPRINTF:
1937 Makes vsprintf (and all *printf functions) support printing
1938 of 64bit values by using the L quantifier
1940 - CFG_64BIT_STRTOUL:
1941 Adds simple_strtoull that returns a 64bit value
1943 Low Level (hardware related) configuration options:
1944 ---------------------------------------------------
1946 - CFG_CACHELINE_SIZE:
1947 Cache Line Size of the CPU.
1950 Default address of the IMMR after system reset.
1952 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU,
1953 and RPXsuper) to be able to adjust the position of
1954 the IMMR register after a reset.
1956 - Floppy Disk Support:
1957 CFG_FDC_DRIVE_NUMBER
1959 the default drive number (default value 0)
1963 defines the spacing between fdc chipset registers
1968 defines the offset of register from address. It
1969 depends on which part of the data bus is connected to
1970 the fdc chipset. (default value 0)
1972 If CFG_ISA_IO_STRIDE CFG_ISA_IO_OFFSET and
1973 CFG_FDC_DRIVE_NUMBER are undefined, they take their
1976 if CFG_FDC_HW_INIT is defined, then the function
1977 fdc_hw_init() is called at the beginning of the FDC
1978 setup. fdc_hw_init() must be provided by the board
1979 source code. It is used to make hardware dependant
1982 - CFG_IMMR: Physical address of the Internal Memory.
1983 DO NOT CHANGE unless you know exactly what you're
1984 doing! (11-4) [MPC8xx/82xx systems only]
1986 - CFG_INIT_RAM_ADDR:
1988 Start address of memory area that can be used for
1989 initial data and stack; please note that this must be
1990 writable memory that is working WITHOUT special
1991 initialization, i. e. you CANNOT use normal RAM which
1992 will become available only after programming the
1993 memory controller and running certain initialization
1996 U-Boot uses the following memory types:
1997 - MPC8xx and MPC8260: IMMR (internal memory of the CPU)
1998 - MPC824X: data cache
1999 - PPC4xx: data cache
2001 - CFG_GBL_DATA_OFFSET:
2003 Offset of the initial data structure in the memory
2004 area defined by CFG_INIT_RAM_ADDR. Usually
2005 CFG_GBL_DATA_OFFSET is chosen such that the initial
2006 data is located at the end of the available space
2007 (sometimes written as (CFG_INIT_RAM_END -
2008 CFG_INIT_DATA_SIZE), and the initial stack is just
2009 below that area (growing from (CFG_INIT_RAM_ADDR +
2010 CFG_GBL_DATA_OFFSET) downward.
2013 On the MPC824X (or other systems that use the data
2014 cache for initial memory) the address chosen for
2015 CFG_INIT_RAM_ADDR is basically arbitrary - it must
2016 point to an otherwise UNUSED address space between
2017 the top of RAM and the start of the PCI space.
2019 - CFG_SIUMCR: SIU Module Configuration (11-6)
2021 - CFG_SYPCR: System Protection Control (11-9)
2023 - CFG_TBSCR: Time Base Status and Control (11-26)
2025 - CFG_PISCR: Periodic Interrupt Status and Control (11-31)
2027 - CFG_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30)
2029 - CFG_SCCR: System Clock and reset Control Register (15-27)
2031 - CFG_OR_TIMING_SDRAM:
2035 periodic timer for refresh
2037 - CFG_DER: Debug Event Register (37-47)
2039 - FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CFG_REMAP_OR_AM,
2040 CFG_PRELIM_OR_AM, CFG_OR_TIMING_FLASH, CFG_OR0_REMAP,
2041 CFG_OR0_PRELIM, CFG_BR0_PRELIM, CFG_OR1_REMAP, CFG_OR1_PRELIM,
2043 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
2045 - SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
2046 CFG_OR_TIMING_SDRAM, CFG_OR2_PRELIM, CFG_BR2_PRELIM,
2047 CFG_OR3_PRELIM, CFG_BR3_PRELIM:
2048 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
2050 - CFG_MAMR_PTA, CFG_MPTPR_2BK_4K, CFG_MPTPR_1BK_4K, CFG_MPTPR_2BK_8K,
2051 CFG_MPTPR_1BK_8K, CFG_MAMR_8COL, CFG_MAMR_9COL:
2052 Machine Mode Register and Memory Periodic Timer
2053 Prescaler definitions (SDRAM timing)
2055 - CFG_I2C_UCODE_PATCH, CFG_I2C_DPMEM_OFFSET [0x1FC0]:
2056 enable I2C microcode relocation patch (MPC8xx);
2057 define relocation offset in DPRAM [DSP2]
2059 - CFG_SPI_UCODE_PATCH, CFG_SPI_DPMEM_OFFSET [0x1FC0]:
2060 enable SPI microcode relocation patch (MPC8xx);
2061 define relocation offset in DPRAM [SCC4]
2064 Use OSCM clock mode on MBX8xx board. Be careful,
2065 wrong setting might damage your board. Read
2066 doc/README.MBX before setting this variable!
2068 - CFG_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only)
2069 Offset of the bootmode word in DPRAM used by post
2070 (Power On Self Tests). This definition overrides
2071 #define'd default value in commproc.h resp.
2074 - CFG_PCI_SLV_MEM_LOCAL, CFG_PCI_SLV_MEM_BUS, CFG_PICMR0_MASK_ATTRIB,
2075 CFG_PCI_MSTR0_LOCAL, CFG_PCIMSK0_MASK, CFG_PCI_MSTR1_LOCAL,
2076 CFG_PCIMSK1_MASK, CFG_PCI_MSTR_MEM_LOCAL, CFG_PCI_MSTR_MEM_BUS,
2077 CFG_CPU_PCI_MEM_START, CFG_PCI_MSTR_MEM_SIZE, CFG_POCMR0_MASK_ATTRIB,
2078 CFG_PCI_MSTR_MEMIO_LOCAL, CFG_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START,
2079 CFG_PCI_MSTR_MEMIO_SIZE, CFG_POCMR1_MASK_ATTRIB, CFG_PCI_MSTR_IO_LOCAL,
2080 CFG_PCI_MSTR_IO_BUS, CFG_CPU_PCI_IO_START, CFG_PCI_MSTR_IO_SIZE,
2081 CFG_POCMR2_MASK_ATTRIB: (MPC826x only)
2082 Overrides the default PCI memory map in cpu/mpc8260/pci.c if set.
2084 - CONFIG_ETHER_ON_FEC[12]
2085 Define to enable FEC[12] on a 8xx series processor.
2087 - CONFIG_FEC[12]_PHY
2088 Define to the hardcoded PHY address which corresponds
2089 to the given FEC; i. e.
2090 #define CONFIG_FEC1_PHY 4
2091 means that the PHY with address 4 is connected to FEC1
2093 When set to -1, means to probe for first available.
2095 - CONFIG_FEC[12]_PHY_NORXERR
2096 The PHY does not have a RXERR line (RMII only).
2097 (so program the FEC to ignore it).
2100 Enable RMII mode for all FECs.
2101 Note that this is a global option, we can't
2102 have one FEC in standard MII mode and another in RMII mode.
2104 - CONFIG_CRC32_VERIFY
2105 Add a verify option to the crc32 command.
2108 => crc32 -v <address> <count> <crc32>
2110 Where address/count indicate a memory area
2111 and crc32 is the correct crc32 which the
2115 Add the "loopw" memory command. This only takes effect if
2116 the memory commands are activated globally (CFG_CMD_MEM).
2119 Add the "mdc" and "mwc" memory commands. These are cyclic
2124 This command will print 4 bytes (10,11,12,13) each 500 ms.
2126 => mwc.l 100 12345678 10
2127 This command will write 12345678 to address 100 all 10 ms.
2129 This only takes effect if the memory commands are activated
2130 globally (CFG_CMD_MEM).
2132 - CONFIG_SKIP_LOWLEVEL_INIT
2133 - CONFIG_SKIP_RELOCATE_UBOOT
2135 [ARM only] If these variables are defined, then
2136 certain low level initializations (like setting up
2137 the memory controller) are omitted and/or U-Boot does
2138 not relocate itself into RAM.
2139 Normally these variables MUST NOT be defined. The
2140 only exception is when U-Boot is loaded (to RAM) by
2141 some other boot loader or by a debugger which
2142 performs these intializations itself.
2145 Building the Software:
2146 ======================
2148 Building U-Boot has been tested in native PPC environments (on a
2149 PowerBook G3 running LinuxPPC 2000) and in cross environments
2150 (running RedHat 6.x and 7.x Linux on x86, Solaris 2.6 on a SPARC, and
2153 If you are not using a native PPC environment, it is assumed that you
2154 have the GNU cross compiling tools available in your path and named
2155 with a prefix of "powerpc-linux-". If this is not the case, (e.g. if
2156 you are using Monta Vista's Hard Hat Linux CDK 1.2) you must change
2157 the definition of CROSS_COMPILE in Makefile. For HHL on a 4xx CPU,
2160 CROSS_COMPILE = ppc_4xx-
2163 U-Boot is intended to be simple to build. After installing the
2164 sources you must configure U-Boot for one specific board type. This
2169 where "NAME_config" is the name of one of the existing
2170 configurations; the following names are supported:
2172 ADCIOP_config FPS860L_config omap730p2_config
2173 ADS860_config GEN860T_config pcu_e_config
2175 AR405_config GENIETV_config PIP405_config
2176 at91rm9200dk_config GTH_config QS823_config
2177 CANBT_config hermes_config QS850_config
2178 cmi_mpc5xx_config hymod_config QS860T_config
2179 cogent_common_config IP860_config RPXlite_config
2180 cogent_mpc8260_config IVML24_config RPXlite_DW_config
2181 cogent_mpc8xx_config IVMS8_config RPXsuper_config
2182 CPCI405_config JSE_config rsdproto_config
2183 CPCIISER4_config LANTEC_config Sandpoint8240_config
2184 csb272_config lwmon_config sbc8260_config
2185 CU824_config MBX860T_config sbc8560_33_config
2186 DUET_ADS_config MBX_config sbc8560_66_config
2187 EBONY_config MPC8260ADS_config SM850_config
2188 ELPT860_config MPC8540ADS_config SPD823TS_config
2189 ESTEEM192E_config MPC8560ADS_config stxgp3_config
2190 ETX094_config NETVIA_config SXNI855T_config
2191 FADS823_config omap1510inn_config TQM823L_config
2192 FADS850SAR_config omap1610h2_config TQM850L_config
2193 FADS860T_config omap1610inn_config TQM855L_config
2194 FPS850L_config omap5912osk_config TQM860L_config
2195 omap2420h4_config walnut_config
2199 Note: for some board special configuration names may exist; check if
2200 additional information is available from the board vendor; for
2201 instance, the TQM823L systems are available without (standard)
2202 or with LCD support. You can select such additional "features"
2203 when chosing the configuration, i. e.
2206 - will configure for a plain TQM823L, i. e. no LCD support
2208 make TQM823L_LCD_config
2209 - will configure for a TQM823L with U-Boot console on LCD
2214 Finally, type "make all", and you should get some working U-Boot
2215 images ready for download to / installation on your system:
2217 - "u-boot.bin" is a raw binary image
2218 - "u-boot" is an image in ELF binary format
2219 - "u-boot.srec" is in Motorola S-Record format
2222 Please be aware that the Makefiles assume you are using GNU make, so
2223 for instance on NetBSD you might need to use "gmake" instead of
2227 If the system board that you have is not listed, then you will need
2228 to port U-Boot to your hardware platform. To do this, follow these
2231 1. Add a new configuration option for your board to the toplevel
2232 "Makefile" and to the "MAKEALL" script, using the existing
2233 entries as examples. Note that here and at many other places
2234 boards and other names are listed in alphabetical sort order. Please
2236 2. Create a new directory to hold your board specific code. Add any
2237 files you need. In your board directory, you will need at least
2238 the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds".
2239 3. Create a new configuration file "include/configs/<board>.h" for
2241 3. If you're porting U-Boot to a new CPU, then also create a new
2242 directory to hold your CPU specific code. Add any files you need.
2243 4. Run "make <board>_config" with your new name.
2244 5. Type "make", and you should get a working "u-boot.srec" file
2245 to be installed on your target system.
2246 6. Debug and solve any problems that might arise.
2247 [Of course, this last step is much harder than it sounds.]
2250 Testing of U-Boot Modifications, Ports to New Hardware, etc.:
2251 ==============================================================
2253 If you have modified U-Boot sources (for instance added a new board
2254 or support for new devices, a new CPU, etc.) you are expected to
2255 provide feedback to the other developers. The feedback normally takes
2256 the form of a "patch", i. e. a context diff against a certain (latest
2257 official or latest in CVS) version of U-Boot sources.
2259 But before you submit such a patch, please verify that your modifi-
2260 cation did not break existing code. At least make sure that *ALL* of
2261 the supported boards compile WITHOUT ANY compiler warnings. To do so,
2262 just run the "MAKEALL" script, which will configure and build U-Boot
2263 for ALL supported system. Be warned, this will take a while. You can
2264 select which (cross) compiler to use by passing a `CROSS_COMPILE'
2265 environment variable to the script, i. e. to use the cross tools from
2266 MontaVista's Hard Hat Linux you can type
2268 CROSS_COMPILE=ppc_8xx- MAKEALL
2270 or to build on a native PowerPC system you can type
2272 CROSS_COMPILE=' ' MAKEALL
2274 See also "U-Boot Porting Guide" below.
2277 Monitor Commands - Overview:
2278 ============================
2280 go - start application at address 'addr'
2281 run - run commands in an environment variable
2282 bootm - boot application image from memory
2283 bootp - boot image via network using BootP/TFTP protocol
2284 tftpboot- boot image via network using TFTP protocol
2285 and env variables "ipaddr" and "serverip"
2286 (and eventually "gatewayip")
2287 rarpboot- boot image via network using RARP/TFTP protocol
2288 diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
2289 loads - load S-Record file over serial line
2290 loadb - load binary file over serial line (kermit mode)
2292 mm - memory modify (auto-incrementing)
2293 nm - memory modify (constant address)
2294 mw - memory write (fill)
2296 cmp - memory compare
2297 crc32 - checksum calculation
2298 imd - i2c memory display
2299 imm - i2c memory modify (auto-incrementing)
2300 inm - i2c memory modify (constant address)
2301 imw - i2c memory write (fill)
2302 icrc32 - i2c checksum calculation
2303 iprobe - probe to discover valid I2C chip addresses
2304 iloop - infinite loop on address range
2305 isdram - print SDRAM configuration information
2306 sspi - SPI utility commands
2307 base - print or set address offset
2308 printenv- print environment variables
2309 setenv - set environment variables
2310 saveenv - save environment variables to persistent storage
2311 protect - enable or disable FLASH write protection
2312 erase - erase FLASH memory
2313 flinfo - print FLASH memory information
2314 bdinfo - print Board Info structure
2315 iminfo - print header information for application image
2316 coninfo - print console devices and informations
2317 ide - IDE sub-system
2318 loop - infinite loop on address range
2319 loopw - infinite write loop on address range
2320 mtest - simple RAM test
2321 icache - enable or disable instruction cache
2322 dcache - enable or disable data cache
2323 reset - Perform RESET of the CPU
2324 echo - echo args to console
2325 version - print monitor version
2326 help - print online help
2327 ? - alias for 'help'
2330 Monitor Commands - Detailed Description:
2331 ========================================
2335 For now: just type "help <command>".
2338 Environment Variables:
2339 ======================
2341 U-Boot supports user configuration using Environment Variables which
2342 can be made persistent by saving to Flash memory.
2344 Environment Variables are set using "setenv", printed using
2345 "printenv", and saved to Flash using "saveenv". Using "setenv"
2346 without a value can be used to delete a variable from the
2347 environment. As long as you don't save the environment you are
2348 working with an in-memory copy. In case the Flash area containing the
2349 environment is erased by accident, a default environment is provided.
2351 Some configuration options can be set using Environment Variables:
2353 baudrate - see CONFIG_BAUDRATE
2355 bootdelay - see CONFIG_BOOTDELAY
2357 bootcmd - see CONFIG_BOOTCOMMAND
2359 bootargs - Boot arguments when booting an RTOS image
2361 bootfile - Name of the image to load with TFTP
2363 autoload - if set to "no" (any string beginning with 'n'),
2364 "bootp" will just load perform a lookup of the
2365 configuration from the BOOTP server, but not try to
2366 load any image using TFTP
2368 autostart - if set to "yes", an image loaded using the "bootp",
2369 "rarpboot", "tftpboot" or "diskboot" commands will
2370 be automatically started (by internally calling
2373 If set to "no", a standalone image passed to the
2374 "bootm" command will be copied to the load address
2375 (and eventually uncompressed), but NOT be started.
2376 This can be used to load and uncompress arbitrary
2379 i2cfast - (PPC405GP|PPC405EP only)
2380 if set to 'y' configures Linux I2C driver for fast
2381 mode (400kHZ). This environment variable is used in
2382 initialization code. So, for changes to be effective
2383 it must be saved and board must be reset.
2385 initrd_high - restrict positioning of initrd images:
2386 If this variable is not set, initrd images will be
2387 copied to the highest possible address in RAM; this
2388 is usually what you want since it allows for
2389 maximum initrd size. If for some reason you want to
2390 make sure that the initrd image is loaded below the
2391 CFG_BOOTMAPSZ limit, you can set this environment
2392 variable to a value of "no" or "off" or "0".
2393 Alternatively, you can set it to a maximum upper
2394 address to use (U-Boot will still check that it
2395 does not overwrite the U-Boot stack and data).
2397 For instance, when you have a system with 16 MB
2398 RAM, and want to reserve 4 MB from use by Linux,
2399 you can do this by adding "mem=12M" to the value of
2400 the "bootargs" variable. However, now you must make
2401 sure that the initrd image is placed in the first
2402 12 MB as well - this can be done with
2404 setenv initrd_high 00c00000
2406 If you set initrd_high to 0xFFFFFFFF, this is an
2407 indication to U-Boot that all addresses are legal
2408 for the Linux kernel, including addresses in flash
2409 memory. In this case U-Boot will NOT COPY the
2410 ramdisk at all. This may be useful to reduce the
2411 boot time on your system, but requires that this
2412 feature is supported by your Linux kernel.
2414 ipaddr - IP address; needed for tftpboot command
2416 loadaddr - Default load address for commands like "bootp",
2417 "rarpboot", "tftpboot", "loadb" or "diskboot"
2419 loads_echo - see CONFIG_LOADS_ECHO
2421 serverip - TFTP server IP address; needed for tftpboot command
2423 bootretry - see CONFIG_BOOT_RETRY_TIME
2425 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
2427 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
2429 ethprime - When CONFIG_NET_MULTI is enabled controls which
2430 interface is used first.
2432 ethact - When CONFIG_NET_MULTI is enabled controls which
2433 interface is currently active. For example you
2434 can do the following
2436 => setenv ethact FEC ETHERNET
2437 => ping 192.168.0.1 # traffic sent on FEC ETHERNET
2438 => setenv ethact SCC ETHERNET
2439 => ping 10.0.0.1 # traffic sent on SCC ETHERNET
2441 netretry - When set to "no" each network operation will
2442 either succeed or fail without retrying.
2443 When set to "once" the network operation will
2444 fail when all the available network interfaces
2445 are tried once without success.
2446 Useful on scripts which control the retry operation
2449 vlan - When set to a value < 4095 the traffic over
2450 ethernet is encapsulated/received over 802.1q
2453 The following environment variables may be used and automatically
2454 updated by the network boot commands ("bootp" and "rarpboot"),
2455 depending the information provided by your boot server:
2457 bootfile - see above
2458 dnsip - IP address of your Domain Name Server
2459 dnsip2 - IP address of your secondary Domain Name Server
2460 gatewayip - IP address of the Gateway (Router) to use
2461 hostname - Target hostname
2463 netmask - Subnet Mask
2464 rootpath - Pathname of the root filesystem on the NFS server
2465 serverip - see above
2468 There are two special Environment Variables:
2470 serial# - contains hardware identification information such
2471 as type string and/or serial number
2472 ethaddr - Ethernet address
2474 These variables can be set only once (usually during manufacturing of
2475 the board). U-Boot refuses to delete or overwrite these variables
2476 once they have been set once.
2479 Further special Environment Variables:
2481 ver - Contains the U-Boot version string as printed
2482 with the "version" command. This variable is
2483 readonly (see CONFIG_VERSION_VARIABLE).
2486 Please note that changes to some configuration parameters may take
2487 only effect after the next boot (yes, that's just like Windoze :-).
2490 Command Line Parsing:
2491 =====================
2493 There are two different command line parsers available with U-Boot:
2494 the old "simple" one, and the much more powerful "hush" shell:
2496 Old, simple command line parser:
2497 --------------------------------
2499 - supports environment variables (through setenv / saveenv commands)
2500 - several commands on one line, separated by ';'
2501 - variable substitution using "... $(name) ..." syntax
2502 - special characters ('$', ';') can be escaped by prefixing with '\',
2504 setenv bootcmd bootm \$(address)
2505 - You can also escape text by enclosing in single apostrophes, for example:
2506 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
2511 - similar to Bourne shell, with control structures like
2512 if...then...else...fi, for...do...done; while...do...done,
2513 until...do...done, ...
2514 - supports environment ("global") variables (through setenv / saveenv
2515 commands) and local shell variables (through standard shell syntax
2516 "name=value"); only environment variables can be used with "run"
2522 (1) If a command line (or an environment variable executed by a "run"
2523 command) contains several commands separated by semicolon, and
2524 one of these commands fails, then the remaining commands will be
2527 (2) If you execute several variables with one call to run (i. e.
2528 calling run with a list af variables as arguments), any failing
2529 command will cause "run" to terminate, i. e. the remaining
2530 variables are not executed.
2532 Note for Redundant Ethernet Interfaces:
2533 =======================================
2535 Some boards come with redundant ethernet interfaces; U-Boot supports
2536 such configurations and is capable of automatic selection of a
2537 "working" interface when needed. MAC assignment works as follows:
2539 Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
2540 MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
2541 "eth1addr" (=>eth1), "eth2addr", ...
2543 If the network interface stores some valid MAC address (for instance
2544 in SROM), this is used as default address if there is NO correspon-
2545 ding setting in the environment; if the corresponding environment
2546 variable is set, this overrides the settings in the card; that means:
2548 o If the SROM has a valid MAC address, and there is no address in the
2549 environment, the SROM's address is used.
2551 o If there is no valid address in the SROM, and a definition in the
2552 environment exists, then the value from the environment variable is
2555 o If both the SROM and the environment contain a MAC address, and
2556 both addresses are the same, this MAC address is used.
2558 o If both the SROM and the environment contain a MAC address, and the
2559 addresses differ, the value from the environment is used and a
2562 o If neither SROM nor the environment contain a MAC address, an error
2569 The "boot" commands of this monitor operate on "image" files which
2570 can be basicly anything, preceeded by a special header; see the
2571 definitions in include/image.h for details; basicly, the header
2572 defines the following image properties:
2574 * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
2575 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
2576 LynxOS, pSOS, QNX, RTEMS, ARTOS;
2577 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, ARTOS, LynxOS).
2578 * Target CPU Architecture (Provisions for Alpha, ARM, Intel x86,
2579 IA64, MIPS, NIOS, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
2580 Currently supported: ARM, Intel x86, MIPS, NIOS, PowerPC).
2581 * Compression Type (uncompressed, gzip, bzip2)
2587 The header is marked by a special Magic Number, and both the header
2588 and the data portions of the image are secured against corruption by
2595 Although U-Boot should support any OS or standalone application
2596 easily, the main focus has always been on Linux during the design of
2599 U-Boot includes many features that so far have been part of some
2600 special "boot loader" code within the Linux kernel. Also, any
2601 "initrd" images to be used are no longer part of one big Linux image;
2602 instead, kernel and "initrd" are separate images. This implementation
2603 serves several purposes:
2605 - the same features can be used for other OS or standalone
2606 applications (for instance: using compressed images to reduce the
2607 Flash memory footprint)
2609 - it becomes much easier to port new Linux kernel versions because
2610 lots of low-level, hardware dependent stuff are done by U-Boot
2612 - the same Linux kernel image can now be used with different "initrd"
2613 images; of course this also means that different kernel images can
2614 be run with the same "initrd". This makes testing easier (you don't
2615 have to build a new "zImage.initrd" Linux image when you just
2616 change a file in your "initrd"). Also, a field-upgrade of the
2617 software is easier now.
2623 Porting Linux to U-Boot based systems:
2624 ---------------------------------------
2626 U-Boot cannot save you from doing all the necessary modifications to
2627 configure the Linux device drivers for use with your target hardware
2628 (no, we don't intend to provide a full virtual machine interface to
2631 But now you can ignore ALL boot loader code (in arch/ppc/mbxboot).
2633 Just make sure your machine specific header file (for instance
2634 include/asm-ppc/tqm8xx.h) includes the same definition of the Board
2635 Information structure as we define in include/u-boot.h, and make
2636 sure that your definition of IMAP_ADDR uses the same value as your
2637 U-Boot configuration in CFG_IMMR.
2640 Configuring the Linux kernel:
2641 -----------------------------
2643 No specific requirements for U-Boot. Make sure you have some root
2644 device (initial ramdisk, NFS) for your target system.
2647 Building a Linux Image:
2648 -----------------------
2650 With U-Boot, "normal" build targets like "zImage" or "bzImage" are
2651 not used. If you use recent kernel source, a new build target
2652 "uImage" will exist which automatically builds an image usable by
2653 U-Boot. Most older kernels also have support for a "pImage" target,
2654 which was introduced for our predecessor project PPCBoot and uses a
2655 100% compatible format.
2664 The "uImage" build target uses a special tool (in 'tools/mkimage') to
2665 encapsulate a compressed Linux kernel image with header information,
2666 CRC32 checksum etc. for use with U-Boot. This is what we are doing:
2668 * build a standard "vmlinux" kernel image (in ELF binary format):
2670 * convert the kernel into a raw binary image:
2672 ${CROSS_COMPILE}-objcopy -O binary \
2673 -R .note -R .comment \
2674 -S vmlinux linux.bin
2676 * compress the binary image:
2680 * package compressed binary image for U-Boot:
2682 mkimage -A ppc -O linux -T kernel -C gzip \
2683 -a 0 -e 0 -n "Linux Kernel Image" \
2684 -d linux.bin.gz uImage
2687 The "mkimage" tool can also be used to create ramdisk images for use
2688 with U-Boot, either separated from the Linux kernel image, or
2689 combined into one file. "mkimage" encapsulates the images with a 64
2690 byte header containing information about target architecture,
2691 operating system, image type, compression method, entry points, time
2692 stamp, CRC32 checksums, etc.
2694 "mkimage" can be called in two ways: to verify existing images and
2695 print the header information, or to build new images.
2697 In the first form (with "-l" option) mkimage lists the information
2698 contained in the header of an existing U-Boot image; this includes
2699 checksum verification:
2701 tools/mkimage -l image
2702 -l ==> list image header information
2704 The second form (with "-d" option) is used to build a U-Boot image
2705 from a "data file" which is used as image payload:
2707 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
2708 -n name -d data_file image
2709 -A ==> set architecture to 'arch'
2710 -O ==> set operating system to 'os'
2711 -T ==> set image type to 'type'
2712 -C ==> set compression type 'comp'
2713 -a ==> set load address to 'addr' (hex)
2714 -e ==> set entry point to 'ep' (hex)
2715 -n ==> set image name to 'name'
2716 -d ==> use image data from 'datafile'
2718 Right now, all Linux kernels for PowerPC systems use the same load
2719 address (0x00000000), but the entry point address depends on the
2722 - 2.2.x kernels have the entry point at 0x0000000C,
2723 - 2.3.x and later kernels have the entry point at 0x00000000.
2725 So a typical call to build a U-Boot image would read:
2727 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
2728 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
2729 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux.gz \
2730 > examples/uImage.TQM850L
2731 Image Name: 2.4.4 kernel for TQM850L
2732 Created: Wed Jul 19 02:34:59 2000
2733 Image Type: PowerPC Linux Kernel Image (gzip compressed)
2734 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
2735 Load Address: 0x00000000
2736 Entry Point: 0x00000000
2738 To verify the contents of the image (or check for corruption):
2740 -> tools/mkimage -l examples/uImage.TQM850L
2741 Image Name: 2.4.4 kernel for TQM850L
2742 Created: Wed Jul 19 02:34:59 2000
2743 Image Type: PowerPC Linux Kernel Image (gzip compressed)
2744 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
2745 Load Address: 0x00000000
2746 Entry Point: 0x00000000
2748 NOTE: for embedded systems where boot time is critical you can trade
2749 speed for memory and install an UNCOMPRESSED image instead: this
2750 needs more space in Flash, but boots much faster since it does not
2751 need to be uncompressed:
2753 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux.gz
2754 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
2755 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
2756 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux \
2757 > examples/uImage.TQM850L-uncompressed
2758 Image Name: 2.4.4 kernel for TQM850L
2759 Created: Wed Jul 19 02:34:59 2000
2760 Image Type: PowerPC Linux Kernel Image (uncompressed)
2761 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
2762 Load Address: 0x00000000
2763 Entry Point: 0x00000000
2766 Similar you can build U-Boot images from a 'ramdisk.image.gz' file
2767 when your kernel is intended to use an initial ramdisk:
2769 -> tools/mkimage -n 'Simple Ramdisk Image' \
2770 > -A ppc -O linux -T ramdisk -C gzip \
2771 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
2772 Image Name: Simple Ramdisk Image
2773 Created: Wed Jan 12 14:01:50 2000
2774 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
2775 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
2776 Load Address: 0x00000000
2777 Entry Point: 0x00000000
2780 Installing a Linux Image:
2781 -------------------------
2783 To downloading a U-Boot image over the serial (console) interface,
2784 you must convert the image to S-Record format:
2786 objcopy -I binary -O srec examples/image examples/image.srec
2788 The 'objcopy' does not understand the information in the U-Boot
2789 image header, so the resulting S-Record file will be relative to
2790 address 0x00000000. To load it to a given address, you need to
2791 specify the target address as 'offset' parameter with the 'loads'
2794 Example: install the image to address 0x40100000 (which on the
2795 TQM8xxL is in the first Flash bank):
2797 => erase 40100000 401FFFFF
2803 ## Ready for S-Record download ...
2804 ~>examples/image.srec
2805 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
2807 15989 15990 15991 15992
2808 [file transfer complete]
2810 ## Start Addr = 0x00000000
2813 You can check the success of the download using the 'iminfo' command;
2814 this includes a checksum verification so you can be sure no data
2815 corruption happened:
2819 ## Checking Image at 40100000 ...
2820 Image Name: 2.2.13 for initrd on TQM850L
2821 Image Type: PowerPC Linux Kernel Image (gzip compressed)
2822 Data Size: 335725 Bytes = 327 kB = 0 MB
2823 Load Address: 00000000
2824 Entry Point: 0000000c
2825 Verifying Checksum ... OK
2831 The "bootm" command is used to boot an application that is stored in
2832 memory (RAM or Flash). In case of a Linux kernel image, the contents
2833 of the "bootargs" environment variable is passed to the kernel as
2834 parameters. You can check and modify this variable using the
2835 "printenv" and "setenv" commands:
2838 => printenv bootargs
2839 bootargs=root=/dev/ram
2841 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
2843 => printenv bootargs
2844 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
2847 ## Booting Linux kernel at 40020000 ...
2848 Image Name: 2.2.13 for NFS on TQM850L
2849 Image Type: PowerPC Linux Kernel Image (gzip compressed)
2850 Data Size: 381681 Bytes = 372 kB = 0 MB
2851 Load Address: 00000000
2852 Entry Point: 0000000c
2853 Verifying Checksum ... OK
2854 Uncompressing Kernel Image ... OK
2855 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
2856 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
2857 time_init: decrementer frequency = 187500000/60
2858 Calibrating delay loop... 49.77 BogoMIPS
2859 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
2862 If you want to boot a Linux kernel with initial ram disk, you pass
2863 the memory addresses of both the kernel and the initrd image (PPBCOOT
2864 format!) to the "bootm" command:
2866 => imi 40100000 40200000
2868 ## Checking Image at 40100000 ...
2869 Image Name: 2.2.13 for initrd on TQM850L
2870 Image Type: PowerPC Linux Kernel Image (gzip compressed)
2871 Data Size: 335725 Bytes = 327 kB = 0 MB
2872 Load Address: 00000000
2873 Entry Point: 0000000c
2874 Verifying Checksum ... OK
2876 ## Checking Image at 40200000 ...
2877 Image Name: Simple Ramdisk Image
2878 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
2879 Data Size: 566530 Bytes = 553 kB = 0 MB
2880 Load Address: 00000000
2881 Entry Point: 00000000
2882 Verifying Checksum ... OK
2884 => bootm 40100000 40200000
2885 ## Booting Linux kernel at 40100000 ...
2886 Image Name: 2.2.13 for initrd on TQM850L
2887 Image Type: PowerPC Linux Kernel Image (gzip compressed)
2888 Data Size: 335725 Bytes = 327 kB = 0 MB
2889 Load Address: 00000000
2890 Entry Point: 0000000c
2891 Verifying Checksum ... OK
2892 Uncompressing Kernel Image ... OK
2893 ## Loading RAMDisk Image at 40200000 ...
2894 Image Name: Simple Ramdisk Image
2895 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
2896 Data Size: 566530 Bytes = 553 kB = 0 MB
2897 Load Address: 00000000
2898 Entry Point: 00000000
2899 Verifying Checksum ... OK
2900 Loading Ramdisk ... OK
2901 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
2902 Boot arguments: root=/dev/ram
2903 time_init: decrementer frequency = 187500000/60
2904 Calibrating delay loop... 49.77 BogoMIPS
2906 RAMDISK: Compressed image found at block 0
2907 VFS: Mounted root (ext2 filesystem).
2911 More About U-Boot Image Types:
2912 ------------------------------
2914 U-Boot supports the following image types:
2916 "Standalone Programs" are directly runnable in the environment
2917 provided by U-Boot; it is expected that (if they behave
2918 well) you can continue to work in U-Boot after return from
2919 the Standalone Program.
2920 "OS Kernel Images" are usually images of some Embedded OS which
2921 will take over control completely. Usually these programs
2922 will install their own set of exception handlers, device
2923 drivers, set up the MMU, etc. - this means, that you cannot
2924 expect to re-enter U-Boot except by resetting the CPU.
2925 "RAMDisk Images" are more or less just data blocks, and their
2926 parameters (address, size) are passed to an OS kernel that is
2928 "Multi-File Images" contain several images, typically an OS
2929 (Linux) kernel image and one or more data images like
2930 RAMDisks. This construct is useful for instance when you want
2931 to boot over the network using BOOTP etc., where the boot
2932 server provides just a single image file, but you want to get
2933 for instance an OS kernel and a RAMDisk image.
2935 "Multi-File Images" start with a list of image sizes, each
2936 image size (in bytes) specified by an "uint32_t" in network
2937 byte order. This list is terminated by an "(uint32_t)0".
2938 Immediately after the terminating 0 follow the images, one by
2939 one, all aligned on "uint32_t" boundaries (size rounded up to
2940 a multiple of 4 bytes).
2942 "Firmware Images" are binary images containing firmware (like
2943 U-Boot or FPGA images) which usually will be programmed to
2946 "Script files" are command sequences that will be executed by
2947 U-Boot's command interpreter; this feature is especially
2948 useful when you configure U-Boot to use a real shell (hush)
2949 as command interpreter.
2955 One of the features of U-Boot is that you can dynamically load and
2956 run "standalone" applications, which can use some resources of
2957 U-Boot like console I/O functions or interrupt services.
2959 Two simple examples are included with the sources:
2964 'examples/hello_world.c' contains a small "Hello World" Demo
2965 application; it is automatically compiled when you build U-Boot.
2966 It's configured to run at address 0x00040004, so you can play with it
2970 ## Ready for S-Record download ...
2971 ~>examples/hello_world.srec
2972 1 2 3 4 5 6 7 8 9 10 11 ...
2973 [file transfer complete]
2975 ## Start Addr = 0x00040004
2977 => go 40004 Hello World! This is a test.
2978 ## Starting application at 0x00040004 ...
2989 Hit any key to exit ...
2991 ## Application terminated, rc = 0x0
2993 Another example, which demonstrates how to register a CPM interrupt
2994 handler with the U-Boot code, can be found in 'examples/timer.c'.
2995 Here, a CPM timer is set up to generate an interrupt every second.
2996 The interrupt service routine is trivial, just printing a '.'
2997 character, but this is just a demo program. The application can be
2998 controlled by the following keys:
3000 ? - print current values og the CPM Timer registers
3001 b - enable interrupts and start timer
3002 e - stop timer and disable interrupts
3003 q - quit application
3006 ## Ready for S-Record download ...
3007 ~>examples/timer.srec
3008 1 2 3 4 5 6 7 8 9 10 11 ...
3009 [file transfer complete]
3011 ## Start Addr = 0x00040004
3014 ## Starting application at 0x00040004 ...
3017 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
3020 [q, b, e, ?] Set interval 1000000 us
3023 [q, b, e, ?] ........
3024 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
3027 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
3030 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
3033 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
3035 [q, b, e, ?] ...Stopping timer
3037 [q, b, e, ?] ## Application terminated, rc = 0x0
3043 Over time, many people have reported problems when trying to use the
3044 "minicom" terminal emulation program for serial download. I (wd)
3045 consider minicom to be broken, and recommend not to use it. Under
3046 Unix, I recommend to use C-Kermit for general purpose use (and
3047 especially for kermit binary protocol download ("loadb" command), and
3048 use "cu" for S-Record download ("loads" command).
3050 Nevertheless, if you absolutely want to use it try adding this
3051 configuration to your "File transfer protocols" section:
3053 Name Program Name U/D FullScr IO-Red. Multi
3054 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
3055 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
3061 Starting at version 0.9.2, U-Boot supports NetBSD both as host
3062 (build U-Boot) and target system (boots NetBSD/mpc8xx).
3064 Building requires a cross environment; it is known to work on
3065 NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
3066 need gmake since the Makefiles are not compatible with BSD make).
3067 Note that the cross-powerpc package does not install include files;
3068 attempting to build U-Boot will fail because <machine/ansi.h> is
3069 missing. This file has to be installed and patched manually:
3071 # cd /usr/pkg/cross/powerpc-netbsd/include
3073 # ln -s powerpc machine
3074 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
3075 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
3077 Native builds *don't* work due to incompatibilities between native
3078 and U-Boot include files.
3080 Booting assumes that (the first part of) the image booted is a
3081 stage-2 loader which in turn loads and then invokes the kernel
3082 proper. Loader sources will eventually appear in the NetBSD source
3083 tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
3084 meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz
3087 Implementation Internals:
3088 =========================
3090 The following is not intended to be a complete description of every
3091 implementation detail. However, it should help to understand the
3092 inner workings of U-Boot and make it easier to port it to custom
3096 Initial Stack, Global Data:
3097 ---------------------------
3099 The implementation of U-Boot is complicated by the fact that U-Boot
3100 starts running out of ROM (flash memory), usually without access to
3101 system RAM (because the memory controller is not initialized yet).
3102 This means that we don't have writable Data or BSS segments, and BSS
3103 is not initialized as zero. To be able to get a C environment working
3104 at all, we have to allocate at least a minimal stack. Implementation
3105 options for this are defined and restricted by the CPU used: Some CPU
3106 models provide on-chip memory (like the IMMR area on MPC8xx and
3107 MPC826x processors), on others (parts of) the data cache can be
3108 locked as (mis-) used as memory, etc.
3110 Chris Hallinan posted a good summary of these issues to the
3111 u-boot-users mailing list:
3113 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
3114 From: "Chris Hallinan" <clh@net1plus.com>
3115 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
3118 Correct me if I'm wrong, folks, but the way I understand it
3119 is this: Using DCACHE as initial RAM for Stack, etc, does not
3120 require any physical RAM backing up the cache. The cleverness
3121 is that the cache is being used as a temporary supply of
3122 necessary storage before the SDRAM controller is setup. It's
3123 beyond the scope of this list to expain the details, but you
3124 can see how this works by studying the cache architecture and
3125 operation in the architecture and processor-specific manuals.
3127 OCM is On Chip Memory, which I believe the 405GP has 4K. It
3128 is another option for the system designer to use as an
3129 initial stack/ram area prior to SDRAM being available. Either
3130 option should work for you. Using CS 4 should be fine if your
3131 board designers haven't used it for something that would
3132 cause you grief during the initial boot! It is frequently not
3135 CFG_INIT_RAM_ADDR should be somewhere that won't interfere
3136 with your processor/board/system design. The default value
3137 you will find in any recent u-boot distribution in
3138 walnut.h should work for you. I'd set it to a value larger
3139 than your SDRAM module. If you have a 64MB SDRAM module, set
3140 it above 400_0000. Just make sure your board has no resources
3141 that are supposed to respond to that address! That code in
3142 start.S has been around a while and should work as is when
3143 you get the config right.
3148 It is essential to remember this, since it has some impact on the C
3149 code for the initialization procedures:
3151 * Initialized global data (data segment) is read-only. Do not attempt
3154 * Do not use any unitialized global data (or implicitely initialized
3155 as zero data - BSS segment) at all - this is undefined, initiali-
3156 zation is performed later (when relocating to RAM).
3158 * Stack space is very limited. Avoid big data buffers or things like
3161 Having only the stack as writable memory limits means we cannot use
3162 normal global data to share information beween the code. But it
3163 turned out that the implementation of U-Boot can be greatly
3164 simplified by making a global data structure (gd_t) available to all
3165 functions. We could pass a pointer to this data as argument to _all_
3166 functions, but this would bloat the code. Instead we use a feature of
3167 the GCC compiler (Global Register Variables) to share the data: we
3168 place a pointer (gd) to the global data into a register which we
3169 reserve for this purpose.
3171 When choosing a register for such a purpose we are restricted by the
3172 relevant (E)ABI specifications for the current architecture, and by
3173 GCC's implementation.
3175 For PowerPC, the following registers have specific use:
3178 R3-R4: parameter passing and return values
3179 R5-R10: parameter passing
3180 R13: small data area pointer
3184 (U-Boot also uses R14 as internal GOT pointer.)
3186 ==> U-Boot will use R29 to hold a pointer to the global data
3188 Note: on PPC, we could use a static initializer (since the
3189 address of the global data structure is known at compile time),
3190 but it turned out that reserving a register results in somewhat
3191 smaller code - although the code savings are not that big (on
3192 average for all boards 752 bytes for the whole U-Boot image,
3193 624 text + 127 data).
3195 On ARM, the following registers are used:
3197 R0: function argument word/integer result
3198 R1-R3: function argument word
3200 R10: stack limit (used only if stack checking if enabled)
3201 R11: argument (frame) pointer
3202 R12: temporary workspace
3205 R15: program counter
3207 ==> U-Boot will use R8 to hold a pointer to the global data
3213 U-Boot runs in system state and uses physical addresses, i.e. the
3214 MMU is not used either for address mapping nor for memory protection.
3216 The available memory is mapped to fixed addresses using the memory
3217 controller. In this process, a contiguous block is formed for each
3218 memory type (Flash, SDRAM, SRAM), even when it consists of several
3219 physical memory banks.
3221 U-Boot is installed in the first 128 kB of the first Flash bank (on
3222 TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
3223 booting and sizing and initializing DRAM, the code relocates itself
3224 to the upper end of DRAM. Immediately below the U-Boot code some
3225 memory is reserved for use by malloc() [see CFG_MALLOC_LEN
3226 configuration setting]. Below that, a structure with global Board
3227 Info data is placed, followed by the stack (growing downward).
3229 Additionally, some exception handler code is copied to the low 8 kB
3230 of DRAM (0x00000000 ... 0x00001FFF).
3232 So a typical memory configuration with 16 MB of DRAM could look like
3235 0x0000 0000 Exception Vector code
3238 0x0000 2000 Free for Application Use
3244 0x00FB FF20 Monitor Stack (Growing downward)
3245 0x00FB FFAC Board Info Data and permanent copy of global data
3246 0x00FC 0000 Malloc Arena
3249 0x00FE 0000 RAM Copy of Monitor Code
3250 ... eventually: LCD or video framebuffer
3251 ... eventually: pRAM (Protected RAM - unchanged by reset)
3252 0x00FF FFFF [End of RAM]
3255 System Initialization:
3256 ----------------------
3258 In the reset configuration, U-Boot starts at the reset entry point
3259 (on most PowerPC systens at address 0x00000100). Because of the reset
3260 configuration for CS0# this is a mirror of the onboard Flash memory.
3261 To be able to re-map memory U-Boot then jumps to its link address.
3262 To be able to implement the initialization code in C, a (small!)
3263 initial stack is set up in the internal Dual Ported RAM (in case CPUs
3264 which provide such a feature like MPC8xx or MPC8260), or in a locked
3265 part of the data cache. After that, U-Boot initializes the CPU core,
3266 the caches and the SIU.
3268 Next, all (potentially) available memory banks are mapped using a
3269 preliminary mapping. For example, we put them on 512 MB boundaries
3270 (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
3271 on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
3272 programmed for SDRAM access. Using the temporary configuration, a
3273 simple memory test is run that determines the size of the SDRAM
3276 When there is more than one SDRAM bank, and the banks are of
3277 different size, the largest is mapped first. For equal size, the first
3278 bank (CS2#) is mapped first. The first mapping is always for address
3279 0x00000000, with any additional banks following immediately to create
3280 contiguous memory starting from 0.
3282 Then, the monitor installs itself at the upper end of the SDRAM area
3283 and allocates memory for use by malloc() and for the global Board
3284 Info data; also, the exception vector code is copied to the low RAM
3285 pages, and the final stack is set up.
3287 Only after this relocation will you have a "normal" C environment;
3288 until that you are restricted in several ways, mostly because you are
3289 running from ROM, and because the code will have to be relocated to a
3293 U-Boot Porting Guide:
3294 ----------------------
3296 [Based on messages by Jerry Van Baren in the U-Boot-Users mailing
3300 int main (int argc, char *argv[])
3302 sighandler_t no_more_time;
3304 signal (SIGALRM, no_more_time);
3305 alarm (PROJECT_DEADLINE - toSec (3 * WEEK));
3307 if (available_money > available_manpower) {
3308 pay consultant to port U-Boot;
3312 Download latest U-Boot source;
3314 Subscribe to u-boot-users mailing list;
3317 email ("Hi, I am new to U-Boot, how do I get started?");
3321 Read the README file in the top level directory;
3322 Read http://www.denx.de/twiki/bin/view/DULG/Manual ;
3323 Read the source, Luke;
3326 if (available_money > toLocalCurrency ($2500)) {
3329 Add a lot of aggravation and time;
3332 Create your own board support subdirectory;
3334 Create your own board config file;
3338 Add / modify source code;
3342 email ("Hi, I am having problems...");
3344 Send patch file to Wolfgang;
3349 void no_more_time (int sig)
3358 All contributions to U-Boot should conform to the Linux kernel
3359 coding style; see the file "Documentation/CodingStyle" in your Linux
3360 kernel source directory.
3362 Please note that U-Boot is implemented in C (and to some small parts
3363 in Assembler); no C++ is used, so please do not use C++ style
3364 comments (//) in your code.
3366 Please also stick to the following formatting rules:
3367 - remove any trailing white space
3368 - use TAB characters for indentation, not spaces
3369 - make sure NOT to use DOS '\r\n' line feeds
3370 - do not add more than 2 empty lines to source files
3371 - do not add trailing empty lines to source files
3373 Submissions which do not conform to the standards may be returned
3374 with a request to reformat the changes.
3380 Since the number of patches for U-Boot is growing, we need to
3381 establish some rules. Submissions which do not conform to these rules
3382 may be rejected, even when they contain important and valuable stuff.
3384 Patches shall be sent to the u-boot-users mailing list.
3386 When you send a patch, please include the following information with
3389 * For bug fixes: a description of the bug and how your patch fixes
3390 this bug. Please try to include a way of demonstrating that the
3391 patch actually fixes something.
3393 * For new features: a description of the feature and your
3396 * A CHANGELOG entry as plaintext (separate from the patch)
3398 * For major contributions, your entry to the CREDITS file
3400 * When you add support for a new board, don't forget to add this
3401 board to the MAKEALL script, too.
3403 * If your patch adds new configuration options, don't forget to
3404 document these in the README file.
3406 * The patch itself. If you are accessing the CVS repository use "cvs
3407 update; cvs diff -puRN"; else, use "diff -purN OLD NEW". If your
3408 version of diff does not support these options, then get the latest
3409 version of GNU diff.
3411 The current directory when running this command shall be the top
3412 level directory of the U-Boot source tree, or it's parent directory
3413 (i. e. please make sure that your patch includes sufficient
3414 directory information for the affected files).
3416 We accept patches as plain text, MIME attachments or as uuencoded
3419 * If one logical set of modifications affects or creates several
3420 files, all these changes shall be submitted in a SINGLE patch file.
3422 * Changesets that contain different, unrelated modifications shall be
3423 submitted as SEPARATE patches, one patch per changeset.
3428 * Before sending the patch, run the MAKEALL script on your patched
3429 source tree and make sure that no errors or warnings are reported
3430 for any of the boards.
3432 * Keep your modifications to the necessary minimum: A patch
3433 containing several unrelated changes or arbitrary reformats will be
3434 returned with a request to re-formatting / split it.
3436 * If you modify existing code, make sure that your new code does not
3437 add to the memory footprint of the code ;-) Small is beautiful!
3438 When adding new features, these should compile conditionally only
3439 (using #ifdef), and the resulting code with the new feature
3440 disabled must not need more memory than the old code without your
3443 * Remember that there is a size limit of 40 kB per message on the
3444 u-boot-users mailing list. Compression may help.
projects / platform / kernel / u-boot.git / blob