2 # (C) Copyright 2000 - 2002
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 and ARM processors, which can be
29 installed in a boot ROM and used to initialize and test the hardware
30 or to download and run application code.
32 The development of U-Boot is closely related to Linux: some parts of
33 the source code originate in the Linux source tree, we have some
34 header files in common, and special provision has been made to
35 support booting of Linux images.
37 Some attention has been paid to make this software easily
38 configurable and extendable. For instance, all monitor commands are
39 implemented with the same call interface, so that it's very easy to
40 add new commands. Also, instead of permanently adding rarely used
41 code (for instance hardware test utilities) to the monitor, you can
42 load and run it dynamically.
48 In general, all boards for which a configuration option exists in the
49 Makefile have been tested to some extent and can be considered
50 "working". In fact, many of them are used in production systems.
52 In case of problems see the CHANGELOG and CREDITS files to find out
53 who contributed the specific port.
59 In case you have questions about, problems with or contributions for
60 U-Boot you should send a message to the U-Boot mailing list at
61 <u-boot-users@lists.sourceforge.net>. There is also an archive of
62 previous traffic on the mailing list - please search the archive
63 before asking FAQ's. Please see
64 http://lists.sourceforge.net/lists/listinfo/u-boot-users/
70 - start from 8xxrom sources
71 - create PPCBoot project (http://sourceforge.net/projects/ppcboot)
73 - make it easier to add custom boards
74 - make it possible to add other [PowerPC] CPUs
75 - extend functions, especially:
76 * Provide extended interface to Linux boot loader
79 * PCMCIA / CompactFLash / ATA disk / SCSI ... boot
80 - create ARMBoot project (http://sourceforge.net/projects/armboot)
81 - add other CPU families (starting with ARM)
82 - create U-Boot project (http://sourceforge.net/projects/u-boot)
88 The "official" name of this project is "Das U-Boot". The spelling
89 "U-Boot" shall be used in all written text (documentation, comments
90 in source files etc.). Example:
92 This is the README file for the U-Boot project.
94 File names etc. shall be based on the string "u-boot". Examples:
96 include/asm-ppc/u-boot.h
98 #include <asm/u-boot.h>
100 Variable names, preprocessor constants etc. shall be either based on
101 the string "u_boot" or on "U_BOOT". Example:
103 U_BOOT_VERSION u_boot_logo
104 IH_OS_U_BOOT u_boot_hush_start
110 U-Boot uses a 3 level version number containing a version, a
111 sub-version, and a patchlevel: "U-Boot-2.34.5" means version "2",
112 sub-version "34", and patchlevel "4".
114 The patchlevel is used to indicate certain stages of development
115 between released versions, i. e. officially released versions of
116 U-Boot will always have a patchlevel of "0".
122 - board Board dependent files
123 - common Misc architecture independent functions
124 - cpu CPU specific files
125 - disk Code for disk drive partition handling
126 - doc Documentation (don't expect too much)
127 - drivers Commonly used device drivers
128 - dtt Digital Thermometer and Thermostat drivers
129 - examples Example code for standalone applications, etc.
130 - include Header Files
131 - disk Harddisk interface code
132 - net Networking code
133 - ppc Files generic to PowerPC architecture
134 - post Power On Self Test
135 - post/arch Symlink to architecture specific Power On Self Test
136 - post/arch-ppc PowerPC architecture specific Power On Self Test
137 - post/cpu/mpc8260 MPC8260 CPU specific Power On Self Test
138 - post/cpu/mpc8xx MPC8xx CPU specific Power On Self Test
139 - rtc Real Time Clock drivers
140 - tools Tools to build S-Record or U-Boot images, etc.
142 - cpu/74xx_7xx Files specific to Motorola MPC74xx and 7xx CPUs
143 - cpu/arm925t Files specific to ARM 925 CPUs
144 - cpu/arm926ejs Files specific to ARM 926 CPUs
145 - cpu/mpc5xx Files specific to Motorola MPC5xx CPUs
146 - cpu/mpc8xx Files specific to Motorola MPC8xx CPUs
147 - cpu/mpc824x Files specific to Motorola MPC824x CPUs
148 - cpu/mpc8260 Files specific to Motorola MPC8260 CPU
149 - cpu/ppc4xx Files specific to IBM 4xx CPUs
152 - board/LEOX/ Files specific to boards manufactured by The LEOX team
153 - board/LEOX/elpt860 Files specific to ELPT860 boards
155 Files specific to RPXClassic boards
156 - board/RPXlite Files specific to RPXlite boards
157 - board/at91rm9200dk Files specific to AT91RM9200DK boards
158 - board/c2mon Files specific to c2mon boards
159 - board/cmi Files specific to cmi boards
160 - board/cogent Files specific to Cogent boards
161 (need further configuration)
162 Files specific to CPCIISER4 boards
163 - board/cpu86 Files specific to CPU86 boards
164 - board/cray/ Files specific to boards manufactured by Cray
165 - board/cray/L1 Files specific to L1 boards
166 - board/cu824 Files specific to CU824 boards
167 - board/ebony Files specific to IBM Ebony board
168 - board/eric Files specific to ERIC boards
169 - board/esd/ Files specific to boards manufactured by ESD
170 - board/esd/adciop Files specific to ADCIOP boards
171 - board/esd/ar405 Files specific to AR405 boards
172 - board/esd/canbt Files specific to CANBT boards
173 - board/esd/cpci405 Files specific to CPCI405 boards
174 - board/esd/cpciiser4 Files specific to CPCIISER4 boards
175 - board/esd/common Common files for ESD boards
176 - board/esd/dasa_sim Files specific to DASA_SIM boards
177 - board/esd/du405 Files specific to DU405 boards
178 - board/esd/ocrtc Files specific to OCRTC boards
179 - board/esd/pci405 Files specific to PCI405 boards
181 Files specific to ESTEEM192E boards
182 - board/etx094 Files specific to ETX_094 boards
184 Files specific to EVB64260 boards
185 - board/fads Files specific to FADS boards
186 - board/flagadm Files specific to FLAGADM boards
187 - board/gen860t Files specific to GEN860T and GEN860T_SC boards
188 - board/genietv Files specific to GENIETV boards
189 - board/gth Files specific to GTH boards
190 - board/hermes Files specific to HERMES boards
191 - board/hymod Files specific to HYMOD boards
192 - board/icu862 Files specific to ICU862 boards
193 - board/ip860 Files specific to IP860 boards
195 Files specific to Interphase4539 boards
196 - board/ivm Files specific to IVMS8/IVML24 boards
197 - board/lantec Files specific to LANTEC boards
198 - board/lwmon Files specific to LWMON boards
199 - board/mbx8xx Files specific to MBX boards
201 Files specific to MPC8260ADS and PQ2FADS-ZU boards
202 - board/mpl/ Files specific to boards manufactured by MPL
203 - board/mpl/common Common files for MPL boards
204 - board/mpl/pip405 Files specific to PIP405 boards
205 - board/mpl/mip405 Files specific to MIP405 boards
206 - board/mpl/vcma9 Files specific to VCMA9 boards
207 - board/musenki Files specific to MUSEKNI boards
208 - board/mvs1 Files specific to MVS1 boards
209 - board/nx823 Files specific to NX823 boards
210 - board/oxc Files specific to OXC boards
212 Files specific to OMAP 1510 Innovator boards
214 Files specific to OMAP 1610 Innovator boards
215 - board/pcippc2 Files specific to PCIPPC2/PCIPPC6 boards
216 - board/pm826 Files specific to PM826 boards
218 Files specific to PPMC8260 boards
220 Files specific to RPXsuper boards
222 Files specific to RSDproto boards
224 Files specific to Sandpoint boards
225 - board/sbc8260 Files specific to SBC8260 boards
226 - board/sacsng Files specific to SACSng boards
227 - board/siemens Files specific to boards manufactured by Siemens AG
228 - board/siemens/CCM Files specific to CCM boards
229 - board/siemens/IAD210 Files specific to IAD210 boards
230 - board/siemens/SCM Files specific to SCM boards
231 - board/siemens/pcu_e Files specific to PCU_E boards
232 - board/sixnet Files specific to SIXNET boards
233 - board/spd8xx Files specific to SPD8xxTS boards
234 - board/tqm8260 Files specific to TQM8260 boards
235 - board/tqm8xx Files specific to TQM8xxL boards
236 - board/w7o Files specific to W7O boards
238 Files specific to Walnut405 boards
239 - board/westel/ Files specific to boards manufactured by Westel Wireless
240 - board/westel/amx860 Files specific to AMX860 boards
241 - board/utx8245 Files specific to UTX8245 boards
242 - board/zpc1900 Files specific to Zephyr Engineering ZPC.1900 board
244 Software Configuration:
245 =======================
247 Configuration is usually done using C preprocessor defines; the
248 rationale behind that is to avoid dead code whenever possible.
250 There are two classes of configuration variables:
252 * Configuration _OPTIONS_:
253 These are selectable by the user and have names beginning with
256 * Configuration _SETTINGS_:
257 These depend on the hardware etc. and should not be meddled with if
258 you don't know what you're doing; they have names beginning with
261 Later we will add a configuration tool - probably similar to or even
262 identical to what's used for the Linux kernel. Right now, we have to
263 do the configuration by hand, which means creating some symbolic
264 links and editing some configuration files. We use the TQM8xxL boards
268 Selection of Processor Architecture and Board Type:
269 ---------------------------------------------------
271 For all supported boards there are ready-to-use default
272 configurations available; just type "make <board_name>_config".
274 Example: For a TQM823L module type:
279 For the Cogent platform, you need to specify the cpu type as well;
280 e.g. "make cogent_mpc8xx_config". And also configure the cogent
281 directory according to the instructions in cogent/README.
284 Configuration Options:
285 ----------------------
287 Configuration depends on the combination of board and CPU type; all
288 such information is kept in a configuration file
289 "include/configs/<board_name>.h".
291 Example: For a TQM823L module, all configuration settings are in
292 "include/configs/TQM823L.h".
295 Many of the options are named exactly as the corresponding Linux
296 kernel configuration options. The intention is to make it easier to
297 build a config tool - later.
300 The following options need to be configured:
302 - CPU Type: Define exactly one of
306 CONFIG_MPC823, CONFIG_MPC850, CONFIG_MPC855, CONFIG_MPC860
308 or CONFIG_MPC824X, CONFIG_MPC8260
323 - Board Type: Define exactly one of
325 PowerPC based boards:
326 ---------------------
328 CONFIG_ADCIOP, CONFIG_ICU862 CONFIG_RPXsuper,
329 CONFIG_ADS860, CONFIG_IP860, CONFIG_SM850,
330 CONFIG_AMX860, CONFIG_IPHASE4539, CONFIG_SPD823TS,
331 CONFIG_AR405, CONFIG_IVML24, CONFIG_SXNI855T,
332 CONFIG_BAB7xx, CONFIG_IVML24_128, CONFIG_Sandpoint8240,
333 CONFIG_CANBT, CONFIG_IVML24_256, CONFIG_Sandpoint8245,
334 CONFIG_CCM, CONFIG_IVMS8, CONFIG_TQM823L,
335 CONFIG_CPCI405, CONFIG_IVMS8_128, CONFIG_TQM850L,
336 CONFIG_CPCI4052, CONFIG_IVMS8_256, CONFIG_TQM855L,
337 CONFIG_CPCIISER4, CONFIG_LANTEC, CONFIG_TQM860L,
338 CONFIG_CPU86, CONFIG_MBX, CONFIG_TQM8260,
339 CONFIG_CRAYL1, CONFIG_MBX860T, CONFIG_TTTech,
340 CONFIG_CU824, CONFIG_MHPC, CONFIG_UTX8245,
341 CONFIG_DASA_SIM, CONFIG_MIP405, CONFIG_W7OLMC,
342 CONFIG_DU405, CONFIG_MOUSSE, CONFIG_W7OLMG,
343 CONFIG_ELPPC, CONFIG_MPC8260ADS, CONFIG_WALNUT405,
344 CONFIG_ERIC, CONFIG_MUSENKI, CONFIG_ZUMA,
345 CONFIG_ESTEEM192E, CONFIG_MVS1, CONFIG_c2mon,
346 CONFIG_ETX094, CONFIG_NX823, CONFIG_cogent_mpc8260,
347 CONFIG_EVB64260, CONFIG_OCRTC, CONFIG_cogent_mpc8xx,
348 CONFIG_FADS823, CONFIG_ORSG, CONFIG_ep8260,
349 CONFIG_FADS850SAR, CONFIG_OXC, CONFIG_gw8260,
350 CONFIG_FADS860T, CONFIG_PCI405, CONFIG_hermes,
351 CONFIG_FLAGADM, CONFIG_PCIPPC2, CONFIG_hymod,
352 CONFIG_FPS850L, CONFIG_PCIPPC6, CONFIG_lwmon,
353 CONFIG_GEN860T, CONFIG_PIP405, CONFIG_pcu_e,
354 CONFIG_GENIETV, CONFIG_PM826, CONFIG_ppmc8260,
355 CONFIG_GTH, CONFIG_RPXClassic, CONFIG_rsdproto,
356 CONFIG_IAD210, CONFIG_RPXlite, CONFIG_sbc8260,
357 CONFIG_EBONY, CONFIG_sacsng, CONFIG_FPS860L,
358 CONFIG_V37, CONFIG_ELPT860, CONFIG_CMI,
359 CONFIG_NETVIA, CONFIG_RBC823, CONFIG_ZPC1900
364 CONFIG_HHP_CRADLE, CONFIG_DNP1110, CONFIG_EP7312,
365 CONFIG_IMPA7, CONFIG_LART, CONFIG_LUBBOCK,
366 CONFIG_INNOVATOROMAP1510, CONFIG_INNOVATOROMAP1610
367 CONFIG_SHANNON, CONFIG_SMDK2400, CONFIG_SMDK2410,
368 CONFIG_TRAB, CONFIG_VCMA9, CONFIG_AT91RM9200DK
371 - CPU Module Type: (if CONFIG_COGENT is defined)
372 Define exactly one of
374 --- FIXME --- not tested yet:
375 CONFIG_CMA286_60, CONFIG_CMA286_21, CONFIG_CMA286_60P,
376 CONFIG_CMA287_23, CONFIG_CMA287_50
378 - Motherboard Type: (if CONFIG_COGENT is defined)
379 Define exactly one of
380 CONFIG_CMA101, CONFIG_CMA102
382 - Motherboard I/O Modules: (if CONFIG_COGENT is defined)
383 Define one or more of
386 - Motherboard Options: (if CONFIG_CMA101 or CONFIG_CMA102 are defined)
387 Define one or more of
388 CONFIG_LCD_HEARTBEAT - update a character position on
389 the lcd display every second with
392 - Board flavour: (if CONFIG_MPC8260ADS is defined)
395 CFG_8260ADS - original MPC8260ADS
396 CFG_8266ADS - MPC8266ADS (untested)
397 CFG_PQ2FADS - PQ2FADS-ZU or PQ2FADS-VR
400 - MPC824X Family Member (if CONFIG_MPC824X is defined)
401 Define exactly one of
402 CONFIG_MPC8240, CONFIG_MPC8245
404 - 8xx CPU Options: (if using an 8xx cpu)
405 Define one or more of
406 CONFIG_8xx_GCLK_FREQ - if get_gclk_freq() can not work e.g.
407 no 32KHz reference PIT/RTC clock
412 U-Boot stores all clock information in Hz
413 internally. For binary compatibility with older Linux
414 kernels (which expect the clocks passed in the
415 bd_info data to be in MHz) the environment variable
416 "clocks_in_mhz" can be defined so that U-Boot
417 converts clock data to MHZ before passing it to the
420 When CONFIG_CLOCKS_IN_MHZ is defined, a definition of
421 "clocks_in_mhz=1" is automatically included in the
425 Depending on board, define exactly one serial port
426 (like CONFIG_8xx_CONS_SMC1, CONFIG_8xx_CONS_SMC2,
427 CONFIG_8xx_CONS_SCC1, ...), or switch off the serial
428 console by defining CONFIG_8xx_CONS_NONE
430 Note: if CONFIG_8xx_CONS_NONE is defined, the serial
431 port routines must be defined elsewhere
432 (i.e. serial_init(), serial_getc(), ...)
435 Enables console device for a color framebuffer. Needs following
436 defines (cf. smiLynxEM, i8042, board/eltec/bab7xx)
437 VIDEO_FB_LITTLE_ENDIAN graphic memory organisation
439 VIDEO_HW_RECTFILL graphic chip supports
442 VIDEO_HW_BITBLT graphic chip supports
443 bit-blit (cf. smiLynxEM)
444 VIDEO_VISIBLE_COLS visible pixel columns
446 VIDEO_VISIBLE_ROWS visible pixel rows
447 VIDEO_PIXEL_SIZE bytes per pixel
448 VIDEO_DATA_FORMAT graphic data format
449 (0-5, cf. cfb_console.c)
450 VIDEO_FB_ADRS framebuffer address
451 VIDEO_KBD_INIT_FCT keyboard int fct
452 (i.e. i8042_kbd_init())
453 VIDEO_TSTC_FCT test char fct
455 VIDEO_GETC_FCT get char fct
457 CONFIG_CONSOLE_CURSOR cursor drawing on/off
458 (requires blink timer
460 CFG_CONSOLE_BLINK_COUNT blink interval (cf. i8042.c)
461 CONFIG_CONSOLE_TIME display time/date info in
463 (requires CFG_CMD_DATE)
464 CONFIG_VIDEO_LOGO display Linux logo in
466 CONFIG_VIDEO_BMP_LOGO use bmp_logo.h instead of
467 linux_logo.h for logo.
468 Requires CONFIG_VIDEO_LOGO
469 CONFIG_CONSOLE_EXTRA_INFO
470 addional board info beside
473 When CONFIG_CFB_CONSOLE is defined, video console is
474 default i/o. Serial console can be forced with
475 environment 'console=serial'.
478 CONFIG_BAUDRATE - in bps
479 Select one of the baudrates listed in
480 CFG_BAUDRATE_TABLE, see below.
482 - Interrupt driven serial port input:
483 CONFIG_SERIAL_SOFTWARE_FIFO
486 Use an interrupt handler for receiving data on the
487 serial port. It also enables using hardware handshake
488 (RTS/CTS) and UART's built-in FIFO. Set the number of
489 bytes the interrupt driven input buffer should have.
491 Set to 0 to disable this feature (this is the default).
492 This will also disable hardware handshake.
494 - Console UART Number:
498 If defined internal UART1 (and not UART0) is used
499 as default U-Boot console.
501 - Boot Delay: CONFIG_BOOTDELAY - in seconds
502 Delay before automatically booting the default image;
503 set to -1 to disable autoboot.
505 See doc/README.autoboot for these options that
506 work with CONFIG_BOOTDELAY. None are required.
507 CONFIG_BOOT_RETRY_TIME
508 CONFIG_BOOT_RETRY_MIN
509 CONFIG_AUTOBOOT_KEYED
510 CONFIG_AUTOBOOT_PROMPT
511 CONFIG_AUTOBOOT_DELAY_STR
512 CONFIG_AUTOBOOT_STOP_STR
513 CONFIG_AUTOBOOT_DELAY_STR2
514 CONFIG_AUTOBOOT_STOP_STR2
515 CONFIG_ZERO_BOOTDELAY_CHECK
516 CONFIG_RESET_TO_RETRY
520 Only needed when CONFIG_BOOTDELAY is enabled;
521 define a command string that is automatically executed
522 when no character is read on the console interface
523 within "Boot Delay" after reset.
526 This can be used to pass arguments to the bootm
527 command. The value of CONFIG_BOOTARGS goes into the
528 environment value "bootargs".
530 CONFIG_RAMBOOT and CONFIG_NFSBOOT
531 The value of these goes into the environment as
532 "ramboot" and "nfsboot" respectively, and can be used
533 as a convenience, when switching between booting from
539 When this option is #defined, the existence of the
540 environment variable "preboot" will be checked
541 immediately before starting the CONFIG_BOOTDELAY
542 countdown and/or running the auto-boot command resp.
543 entering interactive mode.
545 This feature is especially useful when "preboot" is
546 automatically generated or modified. For an example
547 see the LWMON board specific code: here "preboot" is
548 modified when the user holds down a certain
549 combination of keys on the (special) keyboard when
552 - Serial Download Echo Mode:
554 If defined to 1, all characters received during a
555 serial download (using the "loads" command) are
556 echoed back. This might be needed by some terminal
557 emulations (like "cu"), but may as well just take
558 time on others. This setting #define's the initial
559 value of the "loads_echo" environment variable.
561 - Kgdb Serial Baudrate: (if CFG_CMD_KGDB is defined)
563 Select one of the baudrates listed in
564 CFG_BAUDRATE_TABLE, see below.
568 Most monitor functions can be selected (or
569 de-selected) by adjusting the definition of
570 CONFIG_COMMANDS; to select individual functions,
571 #define CONFIG_COMMANDS by "OR"ing any of the
574 #define enables commands:
575 -------------------------
576 CFG_CMD_ASKENV * ask for env variable
577 CFG_CMD_AUTOSCRIPT Autoscript Support
579 CFG_CMD_BEDBUG Include BedBug Debugger
580 CFG_CMD_BMP * BMP support
582 CFG_CMD_CACHE icache, dcache
583 CFG_CMD_CONSOLE coninfo
584 CFG_CMD_DATE * support for RTC, date/time...
585 CFG_CMD_DHCP DHCP support
586 CFG_CMD_DIAG * Diagnostics
587 CFG_CMD_DOC * Disk-On-Chip Support
588 CFG_CMD_DTT Digital Therm and Thermostat
589 CFG_CMD_ECHO * echo arguments
590 CFG_CMD_EEPROM * EEPROM read/write support
591 CFG_CMD_ELF bootelf, bootvx
593 CFG_CMD_FDC * Floppy Disk Support
594 CFG_CMD_FAT FAT partition support
595 CFG_CMD_FDOS * Dos diskette Support
596 CFG_CMD_FLASH flinfo, erase, protect
597 CFG_CMD_FPGA FPGA device initialization support
598 CFG_CMD_HWFLOW * RTS/CTS hw flow control
599 CFG_CMD_I2C * I2C serial bus support
600 CFG_CMD_IDE * IDE harddisk support
602 CFG_CMD_IMLS List all found images
603 CFG_CMD_IMMAP * IMMR dump support
604 CFG_CMD_IRQ * irqinfo
605 CFG_CMD_JFFS2 * JFFS2 Support
609 CFG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base,
611 CFG_CMD_MISC Misc functions like sleep etc
612 CFG_CMD_MMC MMC memory mapped support
613 CFG_CMD_MII MII utility commands
614 CFG_CMD_NAND * NAND support
615 CFG_CMD_NET bootp, tftpboot, rarpboot
616 CFG_CMD_PCI * pciinfo
617 CFG_CMD_PCMCIA * PCMCIA support
618 CFG_CMD_PING * send ICMP ECHO_REQUEST to network host
619 CFG_CMD_PORTIO Port I/O
620 CFG_CMD_REGINFO * Register dump
621 CFG_CMD_RUN run command in env variable
622 CFG_CMD_SAVES save S record dump
623 CFG_CMD_SCSI * SCSI Support
624 CFG_CMD_SDRAM * print SDRAM configuration information
625 CFG_CMD_SETGETDCR Support for DCR Register access (4xx only)
626 CFG_CMD_SPI * SPI serial bus support
627 CFG_CMD_USB * USB support
628 CFG_CMD_VFD * VFD support (TRAB)
629 CFG_CMD_BSP * Board SPecific functions
630 -----------------------------------------------
633 CFG_CMD_DFL Default configuration; at the moment
634 this is includes all commands, except
635 the ones marked with "*" in the list
638 If you don't define CONFIG_COMMANDS it defaults to
639 CFG_CMD_DFL in include/cmd_confdefs.h. A board can
640 override the default settings in the respective
643 EXAMPLE: If you want all functions except of network
644 support you can write:
646 #define CONFIG_COMMANDS (CFG_CMD_ALL & ~CFG_CMD_NET)
649 Note: Don't enable the "icache" and "dcache" commands
650 (configuration option CFG_CMD_CACHE) unless you know
651 what you (and your U-Boot users) are doing. Data
652 cache cannot be enabled on systems like the 8xx or
653 8260 (where accesses to the IMMR region must be
654 uncached), and it cannot be disabled on all other
655 systems where we (mis-) use the data cache to hold an
656 initial stack and some data.
659 XXX - this list needs to get updated!
663 If this variable is defined, it enables watchdog
664 support. There must be support in the platform specific
665 code for a watchdog. For the 8xx and 8260 CPUs, the
666 SIU Watchdog feature is enabled in the SYPCR
670 CONFIG_VERSION_VARIABLE
671 If this variable is defined, an environment variable
672 named "ver" is created by U-Boot showing the U-Boot
673 version as printed by the "version" command.
674 This variable is readonly.
678 When CFG_CMD_DATE is selected, the type of the RTC
679 has to be selected, too. Define exactly one of the
682 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx
683 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC
684 CONFIG_RTC_MC146818 - use MC146818 RTC
685 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC
686 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC
687 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC
688 CONFIG_RTC_DS164x - use Dallas DS164x RTC
690 Note that if the RTC uses I2C, then the I2C interface
691 must also be configured. See I2C Support, below.
695 When CONFIG_TIMESTAMP is selected, the timestamp
696 (date and time) of an image is printed by image
697 commands like bootm or iminfo. This option is
698 automatically enabled when you select CFG_CMD_DATE .
701 CONFIG_MAC_PARTITION and/or CONFIG_DOS_PARTITION
702 and/or CONFIG_ISO_PARTITION
704 If IDE or SCSI support is enabled (CFG_CMD_IDE or
705 CFG_CMD_SCSI) you must configure support for at least
706 one partition type as well.
709 CONFIG_IDE_RESET_ROUTINE
711 Set this to define that instead of a reset Pin, the
712 routine ide_set_reset(int idereset) will be used.
717 Set this to enable ATAPI support.
720 At the moment only there is only support for the
721 SYM53C8XX SCSI controller; define
722 CONFIG_SCSI_SYM53C8XX to enable it.
724 CFG_SCSI_MAX_LUN [8], CFG_SCSI_MAX_SCSI_ID [7] and
725 CFG_SCSI_MAX_DEVICE [CFG_SCSI_MAX_SCSI_ID *
726 CFG_SCSI_MAX_LUN] can be adjusted to define the
727 maximum numbers of LUNs, SCSI ID's and target
729 CFG_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz)
731 - NETWORK Support (PCI):
733 Support for Intel 8254x gigabit chips.
736 Support for Intel 82557/82559/82559ER chips.
737 Optional CONFIG_EEPRO100_SROM_WRITE enables eeprom
738 write routine for first time initialisation.
741 Support for Digital 2114x chips.
742 Optional CONFIG_TULIP_SELECT_MEDIA for board specific
743 modem chip initialisation (KS8761/QS6611).
746 Support for National dp83815 chips.
749 Support for National dp8382[01] gigabit chips.
751 - NETWORK Support (other):
753 CONFIG_DRIVER_LAN91C96
754 Support for SMSC's LAN91C96 chips.
757 Define this to hold the physical address
758 of the LAN91C96's I/O space
760 CONFIG_LAN91C96_USE_32_BIT
761 Define this to enable 32 bit addressing
764 At the moment only the UHCI host controller is
765 supported (PIP405, MIP405); define
766 CONFIG_USB_UHCI to enable it.
767 define CONFIG_USB_KEYBOARD to enable the USB Keyboard
768 end define CONFIG_USB_STORAGE to enable the USB
771 Supported are USB Keyboards and USB Floppy drives
775 The MMC controller on the Intel PXA is supported. To
776 enable this define CONFIG_MMC. The MMC can be
777 accessed from the boot prompt by mapping the device
778 to physical memory similar to flash. Command line is
779 enabled with CFG_CMD_MMC. The MMC driver also works with
780 the FAT fs. This is enabled with CFG_CMD_FAT.
785 Define this to enable standard (PC-Style) keyboard
789 Standard PC keyboard driver with US (is default) and
790 GERMAN key layout (switch via environment 'keymap=de') support.
791 Export function i8042_kbd_init, i8042_tstc and i8042_getc
792 for cfb_console. Supports cursor blinking.
797 Define this to enable video support (for output to
802 Enable Chips & Technologies 69000 Video chip
804 CONFIG_VIDEO_SMI_LYNXEM
805 Enable Silicon Motion SMI 712/710/810 Video chip
806 Videomode are selected via environment 'videomode' with
807 standard LiLo mode numbers.
808 Following modes are supported (* is default):
810 800x600 1024x768 1280x1024
811 256 (8bit) 303* 305 307
812 65536 (16bit) 314 317 31a
813 16,7 Mill (24bit) 315 318 31b
814 (i.e. setenv videomode 317; saveenv; reset;)
816 CONFIG_VIDEO_SED13806
817 Enable Epson SED13806 driver. This driver supports 8bpp
818 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP
819 or CONFIG_VIDEO_SED13806_16BPP
824 Define this to enable a custom keyboard support.
825 This simply calls drv_keyboard_init() which must be
826 defined in your board-specific files.
827 The only board using this so far is RBC823.
829 - LCD Support: CONFIG_LCD
831 Define this to enable LCD support (for output to LCD
832 display); also select one of the supported displays
833 by defining one of these:
835 CONFIG_NEC_NL6648AC33:
837 NEC NL6648AC33-18. Active, color, single scan.
839 CONFIG_NEC_NL6648BC20
841 NEC NL6648BC20-08. 6.5", 640x480.
842 Active, color, single scan.
846 Sharp 320x240. Active, color, single scan.
847 It isn't 16x9, and I am not sure what it is.
849 CONFIG_SHARP_LQ64D341
851 Sharp LQ64D341 display, 640x480.
852 Active, color, single scan.
856 HLD1045 display, 640x480.
857 Active, color, single scan.
861 Optrex CBL50840-2 NF-FW 99 22 M5
863 Hitachi LMG6912RPFC-00T
867 320x240. Black & white.
869 Normally display is black on white background; define
870 CFG_WHITE_ON_BLACK to get it inverted.
872 - Splash Screen Support: CONFIG_SPLASH_SCREEN
874 If this option is set, the environment is checked for
875 a variable "splashimage". If found, the usual display
876 of logo, copyright and system information on the LCD
877 is supressed and the BMP image at the address
878 specified in "splashimage" is loaded instead. The
879 console is redirected to the "nulldev", too. This
880 allows for a "silent" boot where a splash screen is
881 loaded very quickly after power-on.
883 - Compression support:
886 If this option is set, support for bzip2 compressed
887 images is included. If not, only uncompressed and gzip
888 compressed images are supported.
890 NOTE: the bzip2 algorithm requires a lot of RAM, so
891 the malloc area (as defined by CFG_MALLOC_LEN) should
899 Define a default value for ethernet address to use
900 for the respective ethernet interface, in case this
901 is not determined automatically.
906 Define a default value for the IP address to use for
907 the default ethernet interface, in case this is not
908 determined through e.g. bootp.
913 Defines a default value for theIP address of a TFTP
914 server to contact when using the "tftboot" command.
916 - BOOTP Recovery Mode:
917 CONFIG_BOOTP_RANDOM_DELAY
919 If you have many targets in a network that try to
920 boot using BOOTP, you may want to avoid that all
921 systems send out BOOTP requests at precisely the same
922 moment (which would happen for instance at recovery
923 from a power failure, when all systems will try to
924 boot, thus flooding the BOOTP server. Defining
925 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
926 inserted before sending out BOOTP requests. The
927 following delays are insterted then:
929 1st BOOTP request: delay 0 ... 1 sec
930 2nd BOOTP request: delay 0 ... 2 sec
931 3rd BOOTP request: delay 0 ... 4 sec
933 BOOTP requests: delay 0 ... 8 sec
935 - DHCP Advanced Options:
938 You can fine tune the DHCP functionality by adding
939 these flags to the CONFIG_BOOTP_MASK define:
941 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS
942 serverip from a DHCP server, it is possible that more
943 than one DNS serverip is offered to the client.
944 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS
945 serverip will be stored in the additional environment
946 variable "dnsip2". The first DNS serverip is always
947 stored in the variable "dnsip", when CONFIG_BOOTP_DNS
948 is added to the CONFIG_BOOTP_MASK.
950 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable
951 to do a dynamic update of a DNS server. To do this, they
952 need the hostname of the DHCP requester.
953 If CONFIG_BOOP_SEND_HOSTNAME is added to the
954 CONFIG_BOOTP_MASK, the content of the "hostname"
955 environment variable is passed as option 12 to
958 - Status LED: CONFIG_STATUS_LED
960 Several configurations allow to display the current
961 status using a LED. For instance, the LED will blink
962 fast while running U-Boot code, stop blinking as
963 soon as a reply to a BOOTP request was received, and
964 start blinking slow once the Linux kernel is running
965 (supported by a status LED driver in the Linux
966 kernel). Defining CONFIG_STATUS_LED enables this
969 - CAN Support: CONFIG_CAN_DRIVER
971 Defining CONFIG_CAN_DRIVER enables CAN driver support
972 on those systems that support this (optional)
973 feature, like the TQM8xxL modules.
975 - I2C Support: CONFIG_HARD_I2C | CONFIG_SOFT_I2C
977 These enable I2C serial bus commands. Defining either of
978 (but not both of) CONFIG_HARD_I2C or CONFIG_SOFT_I2C will
979 include the appropriate I2C driver for the selected cpu.
981 This will allow you to use i2c commands at the u-boot
982 command line (as long as you set CFG_CMD_I2C in
983 CONFIG_COMMANDS) and communicate with i2c based realtime
984 clock chips. See common/cmd_i2c.c for a description of the
985 command line interface.
987 CONFIG_HARD_I2C selects the CPM hardware driver for I2C.
989 CONFIG_SOFT_I2C configures u-boot to use a software (aka
990 bit-banging) driver instead of CPM or similar hardware
993 There are several other quantities that must also be
994 defined when you define CONFIG_HARD_I2C or CONFIG_SOFT_I2C.
996 In both cases you will need to define CFG_I2C_SPEED
997 to be the frequency (in Hz) at which you wish your i2c bus
998 to run and CFG_I2C_SLAVE to be the address of this node (ie
999 the cpu's i2c node address).
1001 Now, the u-boot i2c code for the mpc8xx (cpu/mpc8xx/i2c.c)
1002 sets the cpu up as a master node and so its address should
1003 therefore be cleared to 0 (See, eg, MPC823e User's Manual
1004 p.16-473). So, set CFG_I2C_SLAVE to 0.
1006 That's all that's required for CONFIG_HARD_I2C.
1008 If you use the software i2c interface (CONFIG_SOFT_I2C)
1009 then the following macros need to be defined (examples are
1010 from include/configs/lwmon.h):
1014 (Optional). Any commands necessary to enable the I2C
1015 controller or configure ports.
1017 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
1021 (Only for MPC8260 CPU). The I/O port to use (the code
1022 assumes both bits are on the same port). Valid values
1023 are 0..3 for ports A..D.
1027 The code necessary to make the I2C data line active
1028 (driven). If the data line is open collector, this
1031 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
1035 The code necessary to make the I2C data line tri-stated
1036 (inactive). If the data line is open collector, this
1039 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
1043 Code that returns TRUE if the I2C data line is high,
1046 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
1050 If <bit> is TRUE, sets the I2C data line high. If it
1051 is FALSE, it clears it (low).
1053 eg: #define I2C_SDA(bit) \
1054 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
1055 else immr->im_cpm.cp_pbdat &= ~PB_SDA
1059 If <bit> is TRUE, sets the I2C clock line high. If it
1060 is FALSE, it clears it (low).
1062 eg: #define I2C_SCL(bit) \
1063 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
1064 else immr->im_cpm.cp_pbdat &= ~PB_SCL
1068 This delay is invoked four times per clock cycle so this
1069 controls the rate of data transfer. The data rate thus
1070 is 1 / (I2C_DELAY * 4). Often defined to be something
1073 #define I2C_DELAY udelay(2)
1077 When a board is reset during an i2c bus transfer
1078 chips might think that the current transfer is still
1079 in progress. On some boards it is possible to access
1080 the i2c SCLK line directly, either by using the
1081 processor pin as a GPIO or by having a second pin
1082 connected to the bus. If this option is defined a
1083 custom i2c_init_board() routine in boards/xxx/board.c
1084 is run early in the boot sequence.
1086 - SPI Support: CONFIG_SPI
1088 Enables SPI driver (so far only tested with
1089 SPI EEPROM, also an instance works with Crystal A/D and
1090 D/As on the SACSng board)
1094 Enables extended (16-bit) SPI EEPROM addressing.
1095 (symmetrical to CONFIG_I2C_X)
1099 Enables a software (bit-bang) SPI driver rather than
1100 using hardware support. This is a general purpose
1101 driver that only requires three general I/O port pins
1102 (two outputs, one input) to function. If this is
1103 defined, the board configuration must define several
1104 SPI configuration items (port pins to use, etc). For
1105 an example, see include/configs/sacsng.h.
1107 - FPGA Support: CONFIG_FPGA_COUNT
1109 Specify the number of FPGA devices to support.
1113 Used to specify the types of FPGA devices. For
1115 #define CONFIG_FPGA CFG_XILINX_VIRTEX2
1117 CFG_FPGA_PROG_FEEDBACK
1119 Enable printing of hash marks during FPGA
1124 Enable checks on FPGA configuration interface busy
1125 status by the configuration function. This option
1126 will require a board or device specific function to
1131 If defined, a function that provides delays in the
1132 FPGA configuration driver.
1134 CFG_FPGA_CHECK_CTRLC
1136 Allow Control-C to interrupt FPGA configuration
1138 CFG_FPGA_CHECK_ERROR
1140 Check for configuration errors during FPGA bitfile
1141 loading. For example, abort during Virtex II
1142 configuration if the INIT_B line goes low (which
1143 indicated a CRC error).
1147 Maximum time to wait for the INIT_B line to deassert
1148 after PROB_B has been deasserted during a Virtex II
1149 FPGA configuration sequence. The default time is 500 mS.
1153 Maximum time to wait for BUSY to deassert during
1154 Virtex II FPGA configuration. The default is 5 mS.
1156 CFG_FPGA_WAIT_CONFIG
1158 Time to wait after FPGA configuration. The default is
1161 - FPGA Support: CONFIG_FPGA_COUNT
1163 Specify the number of FPGA devices to support.
1167 Used to specify the types of FPGA devices. For example,
1168 #define CONFIG_FPGA CFG_XILINX_VIRTEX2
1170 CFG_FPGA_PROG_FEEDBACK
1172 Enable printing of hash marks during FPGA configuration.
1176 Enable checks on FPGA configuration interface busy
1177 status by the configuration function. This option
1178 will require a board or device specific function to
1183 If defined, a function that provides delays in the FPGA
1184 configuration driver.
1186 CFG_FPGA_CHECK_CTRLC
1187 Allow Control-C to interrupt FPGA configuration
1189 CFG_FPGA_CHECK_ERROR
1191 Check for configuration errors during FPGA bitfile
1192 loading. For example, abort during Virtex II
1193 configuration if the INIT_B line goes low (which
1194 indicated a CRC error).
1198 Maximum time to wait for the INIT_B line to deassert
1199 after PROB_B has been deasserted during a Virtex II
1200 FPGA configuration sequence. The default time is 500
1205 Maximum time to wait for BUSY to deassert during
1206 Virtex II FPGA configuration. The default is 5 mS.
1208 CFG_FPGA_WAIT_CONFIG
1210 Time to wait after FPGA configuration. The default is
1213 - Configuration Management:
1216 If defined, this string will be added to the U-Boot
1217 version information (U_BOOT_VERSION)
1219 - Vendor Parameter Protection:
1221 U-Boot considers the values of the environment
1222 variables "serial#" (Board Serial Number) and
1223 "ethaddr" (Ethernet Address) to be parameters that
1224 are set once by the board vendor / manufacturer, and
1225 protects these variables from casual modification by
1226 the user. Once set, these variables are read-only,
1227 and write or delete attempts are rejected. You can
1228 change this behviour:
1230 If CONFIG_ENV_OVERWRITE is #defined in your config
1231 file, the write protection for vendor parameters is
1232 completely disabled. Anybody can change or delete
1235 Alternatively, if you #define _both_ CONFIG_ETHADDR
1236 _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
1237 ethernet address is installed in the environment,
1238 which can be changed exactly ONCE by the user. [The
1239 serial# is unaffected by this, i. e. it remains
1245 Define this variable to enable the reservation of
1246 "protected RAM", i. e. RAM which is not overwritten
1247 by U-Boot. Define CONFIG_PRAM to hold the number of
1248 kB you want to reserve for pRAM. You can overwrite
1249 this default value by defining an environment
1250 variable "pram" to the number of kB you want to
1251 reserve. Note that the board info structure will
1252 still show the full amount of RAM. If pRAM is
1253 reserved, a new environment variable "mem" will
1254 automatically be defined to hold the amount of
1255 remaining RAM in a form that can be passed as boot
1256 argument to Linux, for instance like that:
1258 setenv bootargs ... mem=\$(mem)
1261 This way you can tell Linux not to use this memory,
1262 either, which results in a memory region that will
1263 not be affected by reboots.
1265 *WARNING* If your board configuration uses automatic
1266 detection of the RAM size, you must make sure that
1267 this memory test is non-destructive. So far, the
1268 following board configurations are known to be
1271 ETX094, IVMS8, IVML24, SPD8xx, TQM8xxL,
1272 HERMES, IP860, RPXlite, LWMON, LANTEC,
1273 PCU_E, FLAGADM, TQM8260
1278 Define this variable to stop the system in case of a
1279 fatal error, so that you have to reset it manually.
1280 This is probably NOT a good idea for an embedded
1281 system where you want to system to reboot
1282 automatically as fast as possible, but it may be
1283 useful during development since you can try to debug
1284 the conditions that lead to the situation.
1286 CONFIG_NET_RETRY_COUNT
1288 This variable defines the number of retries for
1289 network operations like ARP, RARP, TFTP, or BOOTP
1290 before giving up the operation. If not defined, a
1291 default value of 5 is used.
1293 - Command Interpreter:
1296 Define this variable to enable the "hush" shell (from
1297 Busybox) as command line interpreter, thus enabling
1298 powerful command line syntax like
1299 if...then...else...fi conditionals or `&&' and '||'
1300 constructs ("shell scripts").
1302 If undefined, you get the old, much simpler behaviour
1303 with a somewhat smaller memory footprint.
1308 This defines the secondary prompt string, which is
1309 printed when the command interpreter needs more input
1310 to complete a command. Usually "> ".
1314 In the current implementation, the local variables
1315 space and global environment variables space are
1316 separated. Local variables are those you define by
1317 simply typing `name=value'. To access a local
1318 variable later on, you have write `$name' or
1319 `${name}'; to execute the contents of a variable
1320 directly type `$name' at the command prompt.
1322 Global environment variables are those you use
1323 setenv/printenv to work with. To run a command stored
1324 in such a variable, you need to use the run command,
1325 and you must not use the '$' sign to access them.
1327 To store commands and special characters in a
1328 variable, please use double quotation marks
1329 surrounding the whole text of the variable, instead
1330 of the backslashes before semicolons and special
1333 - Default Environment
1334 CONFIG_EXTRA_ENV_SETTINGS
1336 Define this to contain any number of null terminated
1337 strings (variable = value pairs) that will be part of
1338 the default environment compiled into the boot image.
1340 For example, place something like this in your
1341 board's config file:
1343 #define CONFIG_EXTRA_ENV_SETTINGS \
1347 Warning: This method is based on knowledge about the
1348 internal format how the environment is stored by the
1349 U-Boot code. This is NOT an official, exported
1350 interface! Although it is unlikely that this format
1351 will change soon, there is no guarantee either.
1352 You better know what you are doing here.
1354 Note: overly (ab)use of the default environment is
1355 discouraged. Make sure to check other ways to preset
1356 the environment like the autoscript function or the
1360 CONFIG_HAS_DATAFLASH
1362 Defining this option enables DataFlash features and
1363 allows to read/write in Dataflash via the standard
1366 - Show boot progress
1367 CONFIG_SHOW_BOOT_PROGRESS
1369 Defining this option allows to add some board-
1370 specific code (calling a user-provided function
1371 "show_boot_progress(int)") that enables you to show
1372 the system's boot progress on some display (for
1373 example, some LED's) on your board. At the moment,
1374 the following checkpoints are implemented:
1377 1 common/cmd_bootm.c before attempting to boot an image
1378 -1 common/cmd_bootm.c Image header has bad magic number
1379 2 common/cmd_bootm.c Image header has correct magic number
1380 -2 common/cmd_bootm.c Image header has bad checksum
1381 3 common/cmd_bootm.c Image header has correct checksum
1382 -3 common/cmd_bootm.c Image data has bad checksum
1383 4 common/cmd_bootm.c Image data has correct checksum
1384 -4 common/cmd_bootm.c Image is for unsupported architecture
1385 5 common/cmd_bootm.c Architecture check OK
1386 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi, standalone)
1387 6 common/cmd_bootm.c Image Type check OK
1388 -6 common/cmd_bootm.c gunzip uncompression error
1389 -7 common/cmd_bootm.c Unimplemented compression type
1390 7 common/cmd_bootm.c Uncompression OK
1391 -8 common/cmd_bootm.c Wrong Image Type (not kernel, multi, standalone)
1392 8 common/cmd_bootm.c Image Type check OK
1393 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX)
1394 9 common/cmd_bootm.c Start initial ramdisk verification
1395 -10 common/cmd_bootm.c Ramdisk header has bad magic number
1396 -11 common/cmd_bootm.c Ramdisk header has bad checksum
1397 10 common/cmd_bootm.c Ramdisk header is OK
1398 -12 common/cmd_bootm.c Ramdisk data has bad checksum
1399 11 common/cmd_bootm.c Ramdisk data has correct checksum
1400 12 common/cmd_bootm.c Ramdisk verification complete, start loading
1401 -13 common/cmd_bootm.c Wrong Image Type (not PPC Linux Ramdisk)
1402 13 common/cmd_bootm.c Start multifile image verification
1403 14 common/cmd_bootm.c No initial ramdisk, no multifile, continue.
1404 15 common/cmd_bootm.c All preparation done, transferring control to OS
1406 -1 common/cmd_doc.c Bad usage of "doc" command
1407 -1 common/cmd_doc.c No boot device
1408 -1 common/cmd_doc.c Unknown Chip ID on boot device
1409 -1 common/cmd_doc.c Read Error on boot device
1410 -1 common/cmd_doc.c Image header has bad magic number
1412 -1 common/cmd_ide.c Bad usage of "ide" command
1413 -1 common/cmd_ide.c No boot device
1414 -1 common/cmd_ide.c Unknown boot device
1415 -1 common/cmd_ide.c Unknown partition table
1416 -1 common/cmd_ide.c Invalid partition type
1417 -1 common/cmd_ide.c Read Error on boot device
1418 -1 common/cmd_ide.c Image header has bad magic number
1420 -1 common/cmd_nand.c Bad usage of "nand" command
1421 -1 common/cmd_nand.c No boot device
1422 -1 common/cmd_nand.c Unknown Chip ID on boot device
1423 -1 common/cmd_nand.c Read Error on boot device
1424 -1 common/cmd_nand.c Image header has bad magic number
1426 -1 common/env_common.c Environment has a bad CRC, using default
1432 [so far only for SMDK2400 and TRAB boards]
1434 - Modem support endable:
1435 CONFIG_MODEM_SUPPORT
1437 - RTS/CTS Flow control enable:
1440 - Modem debug support:
1441 CONFIG_MODEM_SUPPORT_DEBUG
1443 Enables debugging stuff (char screen[1024], dbg())
1444 for modem support. Useful only with BDI2000.
1448 In the target system modem support is enabled when a
1449 specific key (key combination) is pressed during
1450 power-on. Otherwise U-Boot will boot normally
1451 (autoboot). The key_pressed() fuction is called from
1452 board_init(). Currently key_pressed() is a dummy
1453 function, returning 1 and thus enabling modem
1456 If there are no modem init strings in the
1457 environment, U-Boot proceed to autoboot; the
1458 previous output (banner, info printfs) will be
1461 See also: doc/README.Modem
1464 Configuration Settings:
1465 -----------------------
1467 - CFG_LONGHELP: Defined when you want long help messages included;
1468 undefine this when you're short of memory.
1470 - CFG_PROMPT: This is what U-Boot prints on the console to
1471 prompt for user input.
1473 - CFG_CBSIZE: Buffer size for input from the Console
1475 - CFG_PBSIZE: Buffer size for Console output
1477 - CFG_MAXARGS: max. Number of arguments accepted for monitor commands
1479 - CFG_BARGSIZE: Buffer size for Boot Arguments which are passed to
1480 the application (usually a Linux kernel) when it is
1483 - CFG_BAUDRATE_TABLE:
1484 List of legal baudrate settings for this board.
1486 - CFG_CONSOLE_INFO_QUIET
1487 Suppress display of console information at boot.
1489 - CFG_CONSOLE_IS_IN_ENV
1490 If the board specific function
1491 extern int overwrite_console (void);
1492 returns 1, the stdin, stderr and stdout are switched to the
1493 serial port, else the settings in the environment are used.
1495 - CFG_CONSOLE_OVERWRITE_ROUTINE
1496 Enable the call to overwrite_console().
1498 - CFG_CONSOLE_ENV_OVERWRITE
1499 Enable overwrite of previous console environment settings.
1501 - CFG_MEMTEST_START, CFG_MEMTEST_END:
1502 Begin and End addresses of the area used by the
1506 Enable an alternate, more extensive memory test.
1508 - CFG_MEMTEST_SCRATCH:
1509 Scratch address used by the alternate memory test
1510 You only need to set this if address zero isn't writeable
1512 - CFG_TFTP_LOADADDR:
1513 Default load address for network file downloads
1515 - CFG_LOADS_BAUD_CHANGE:
1516 Enable temporary baudrate change while serial download
1519 Physical start address of SDRAM. _Must_ be 0 here.
1522 Physical start address of Motherboard I/O (if using a
1526 Physical start address of Flash memory.
1529 Physical start address of boot monitor code (set by
1530 make config files to be same as the text base address
1531 (TEXT_BASE) used when linking) - same as
1532 CFG_FLASH_BASE when booting from flash.
1535 Size of memory reserved for monitor code, used to
1536 determine _at_compile_time_ (!) if the environment is
1537 embedded within the U-Boot image, or in a separate
1541 Size of DRAM reserved for malloc() use.
1544 Maximum size of memory mapped by the startup code of
1545 the Linux kernel; all data that must be processed by
1546 the Linux kernel (bd_info, boot arguments, eventually
1547 initrd image) must be put below this limit.
1549 - CFG_MAX_FLASH_BANKS:
1550 Max number of Flash memory banks
1552 - CFG_MAX_FLASH_SECT:
1553 Max number of sectors on a Flash chip
1555 - CFG_FLASH_ERASE_TOUT:
1556 Timeout for Flash erase operations (in ms)
1558 - CFG_FLASH_WRITE_TOUT:
1559 Timeout for Flash write operations (in ms)
1561 - CFG_FLASH_LOCK_TOUT
1562 Timeout for Flash set sector lock bit operation (in ms)
1564 - CFG_FLASH_UNLOCK_TOUT
1565 Timeout for Flash clear lock bits operation (in ms)
1567 - CFG_FLASH_PROTECTION
1568 If defined, hardware flash sectors protection is used
1569 instead of U-Boot software protection.
1571 - CFG_DIRECT_FLASH_TFTP:
1573 Enable TFTP transfers directly to flash memory;
1574 without this option such a download has to be
1575 performed in two steps: (1) download to RAM, and (2)
1576 copy from RAM to flash.
1578 The two-step approach is usually more reliable, since
1579 you can check if the download worked before you erase
1580 the flash, but in some situations (when sytem RAM is
1581 too limited to allow for a tempory copy of the
1582 downloaded image) this option may be very useful.
1585 Define if the flash driver uses extra elements in the
1586 common flash structure for storing flash geometry
1588 - CFG_RX_ETH_BUFFER:
1589 Defines the number of ethernet receive buffers. On some
1590 ethernet controllers it is recommended to set this value
1591 to 8 or even higher (EEPRO100 or 405 EMAC), since all
1592 buffers can be full shortly after enabling the interface
1593 on high ethernet traffic.
1594 Defaults to 4 if not defined.
1596 The following definitions that deal with the placement and management
1597 of environment data (variable area); in general, we support the
1598 following configurations:
1600 - CFG_ENV_IS_IN_FLASH:
1602 Define this if the environment is in flash memory.
1604 a) The environment occupies one whole flash sector, which is
1605 "embedded" in the text segment with the U-Boot code. This
1606 happens usually with "bottom boot sector" or "top boot
1607 sector" type flash chips, which have several smaller
1608 sectors at the start or the end. For instance, such a
1609 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In
1610 such a case you would place the environment in one of the
1611 4 kB sectors - with U-Boot code before and after it. With
1612 "top boot sector" type flash chips, you would put the
1613 environment in one of the last sectors, leaving a gap
1614 between U-Boot and the environment.
1618 Offset of environment data (variable area) to the
1619 beginning of flash memory; for instance, with bottom boot
1620 type flash chips the second sector can be used: the offset
1621 for this sector is given here.
1623 CFG_ENV_OFFSET is used relative to CFG_FLASH_BASE.
1627 This is just another way to specify the start address of
1628 the flash sector containing the environment (instead of
1631 - CFG_ENV_SECT_SIZE:
1633 Size of the sector containing the environment.
1636 b) Sometimes flash chips have few, equal sized, BIG sectors.
1637 In such a case you don't want to spend a whole sector for
1642 If you use this in combination with CFG_ENV_IS_IN_FLASH
1643 and CFG_ENV_SECT_SIZE, you can specify to use only a part
1644 of this flash sector for the environment. This saves
1645 memory for the RAM copy of the environment.
1647 It may also save flash memory if you decide to use this
1648 when your environment is "embedded" within U-Boot code,
1649 since then the remainder of the flash sector could be used
1650 for U-Boot code. It should be pointed out that this is
1651 STRONGLY DISCOURAGED from a robustness point of view:
1652 updating the environment in flash makes it always
1653 necessary to erase the WHOLE sector. If something goes
1654 wrong before the contents has been restored from a copy in
1655 RAM, your target system will be dead.
1657 - CFG_ENV_ADDR_REDUND
1660 These settings describe a second storage area used to hold
1661 a redundand copy of the environment data, so that there is
1662 a valid backup copy in case there is a power failure during
1663 a "saveenv" operation.
1665 BE CAREFUL! Any changes to the flash layout, and some changes to the
1666 source code will make it necessary to adapt <board>/u-boot.lds*
1670 - CFG_ENV_IS_IN_NVRAM:
1672 Define this if you have some non-volatile memory device
1673 (NVRAM, battery buffered SRAM) which you want to use for the
1679 These two #defines are used to determin the memory area you
1680 want to use for environment. It is assumed that this memory
1681 can just be read and written to, without any special
1684 BE CAREFUL! The first access to the environment happens quite early
1685 in U-Boot initalization (when we try to get the setting of for the
1686 console baudrate). You *MUST* have mappend your NVRAM area then, or
1689 Please note that even with NVRAM we still use a copy of the
1690 environment in RAM: we could work on NVRAM directly, but we want to
1691 keep settings there always unmodified except somebody uses "saveenv"
1692 to save the current settings.
1695 - CFG_ENV_IS_IN_EEPROM:
1697 Use this if you have an EEPROM or similar serial access
1698 device and a driver for it.
1703 These two #defines specify the offset and size of the
1704 environment area within the total memory of your EEPROM.
1706 - CFG_I2C_EEPROM_ADDR:
1707 If defined, specified the chip address of the EEPROM device.
1708 The default address is zero.
1710 - CFG_EEPROM_PAGE_WRITE_BITS:
1711 If defined, the number of bits used to address bytes in a
1712 single page in the EEPROM device. A 64 byte page, for example
1713 would require six bits.
1715 - CFG_EEPROM_PAGE_WRITE_DELAY_MS:
1716 If defined, the number of milliseconds to delay between
1717 page writes. The default is zero milliseconds.
1719 - CFG_I2C_EEPROM_ADDR_LEN:
1720 The length in bytes of the EEPROM memory array address. Note
1721 that this is NOT the chip address length!
1724 The size in bytes of the EEPROM device.
1727 - CFG_SPI_INIT_OFFSET
1729 Defines offset to the initial SPI buffer area in DPRAM. The
1730 area is used at an early stage (ROM part) if the environment
1731 is configured to reside in the SPI EEPROM: We need a 520 byte
1732 scratch DPRAM area. It is used between the two initialization
1733 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems
1734 to be a good choice since it makes it far enough from the
1735 start of the data area as well as from the stack pointer.
1737 Please note that the environment is read-only as long as the monitor
1738 has been relocated to RAM and a RAM copy of the environment has been
1739 created; also, when using EEPROM you will have to use getenv_r()
1740 until then to read environment variables.
1742 The environment is protected by a CRC32 checksum. Before the monitor
1743 is relocated into RAM, as a result of a bad CRC you will be working
1744 with the compiled-in default environment - *silently*!!! [This is
1745 necessary, because the first environment variable we need is the
1746 "baudrate" setting for the console - if we have a bad CRC, we don't
1747 have any device yet where we could complain.]
1749 Note: once the monitor has been relocated, then it will complain if
1750 the default environment is used; a new CRC is computed as soon as you
1751 use the "saveenv" command to store a valid environment.
1753 - CFG_FAULT_ECHO_LINK_DOWN:
1754 Echo the inverted Ethernet link state to the fault LED.
1756 Note: If this option is active, then CFG_FAULT_MII_ADDR
1757 also needs to be defined.
1759 - CFG_FAULT_MII_ADDR:
1760 MII address of the PHY to check for the Ethernet link state.
1762 Low Level (hardware related) configuration options:
1763 ---------------------------------------------------
1765 - CFG_CACHELINE_SIZE:
1766 Cache Line Size of the CPU.
1769 Default address of the IMMR after system reset.
1771 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU,
1772 and RPXsuper) to be able to adjust the position of
1773 the IMMR register after a reset.
1775 - Floppy Disk Support:
1776 CFG_FDC_DRIVE_NUMBER
1778 the default drive number (default value 0)
1782 defines the spacing between fdc chipset registers
1787 defines the offset of register from address. It
1788 depends on which part of the data bus is connected to
1789 the fdc chipset. (default value 0)
1791 If CFG_ISA_IO_STRIDE CFG_ISA_IO_OFFSET and
1792 CFG_FDC_DRIVE_NUMBER are undefined, they take their
1795 if CFG_FDC_HW_INIT is defined, then the function
1796 fdc_hw_init() is called at the beginning of the FDC
1797 setup. fdc_hw_init() must be provided by the board
1798 source code. It is used to make hardware dependant
1801 - CFG_IMMR: Physical address of the Internal Memory Mapped
1802 Register; DO NOT CHANGE! (11-4)
1803 [MPC8xx systems only]
1805 - CFG_INIT_RAM_ADDR:
1807 Start address of memory area that can be used for
1808 initial data and stack; please note that this must be
1809 writable memory that is working WITHOUT special
1810 initialization, i. e. you CANNOT use normal RAM which
1811 will become available only after programming the
1812 memory controller and running certain initialization
1815 U-Boot uses the following memory types:
1816 - MPC8xx and MPC8260: IMMR (internal memory of the CPU)
1817 - MPC824X: data cache
1818 - PPC4xx: data cache
1820 - CFG_GBL_DATA_OFFSET:
1822 Offset of the initial data structure in the memory
1823 area defined by CFG_INIT_RAM_ADDR. Usually
1824 CFG_GBL_DATA_OFFSET is chosen such that the initial
1825 data is located at the end of the available space
1826 (sometimes written as (CFG_INIT_RAM_END -
1827 CFG_INIT_DATA_SIZE), and the initial stack is just
1828 below that area (growing from (CFG_INIT_RAM_ADDR +
1829 CFG_GBL_DATA_OFFSET) downward.
1832 On the MPC824X (or other systems that use the data
1833 cache for initial memory) the address chosen for
1834 CFG_INIT_RAM_ADDR is basically arbitrary - it must
1835 point to an otherwise UNUSED address space between
1836 the top of RAM and the start of the PCI space.
1838 - CFG_SIUMCR: SIU Module Configuration (11-6)
1840 - CFG_SYPCR: System Protection Control (11-9)
1842 - CFG_TBSCR: Time Base Status and Control (11-26)
1844 - CFG_PISCR: Periodic Interrupt Status and Control (11-31)
1846 - CFG_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30)
1848 - CFG_SCCR: System Clock and reset Control Register (15-27)
1850 - CFG_OR_TIMING_SDRAM:
1854 periodic timer for refresh
1856 - CFG_DER: Debug Event Register (37-47)
1858 - FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CFG_REMAP_OR_AM,
1859 CFG_PRELIM_OR_AM, CFG_OR_TIMING_FLASH, CFG_OR0_REMAP,
1860 CFG_OR0_PRELIM, CFG_BR0_PRELIM, CFG_OR1_REMAP, CFG_OR1_PRELIM,
1862 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
1864 - SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
1865 CFG_OR_TIMING_SDRAM, CFG_OR2_PRELIM, CFG_BR2_PRELIM,
1866 CFG_OR3_PRELIM, CFG_BR3_PRELIM:
1867 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
1869 - CFG_MAMR_PTA, CFG_MPTPR_2BK_4K, CFG_MPTPR_1BK_4K, CFG_MPTPR_2BK_8K,
1870 CFG_MPTPR_1BK_8K, CFG_MAMR_8COL, CFG_MAMR_9COL:
1871 Machine Mode Register and Memory Periodic Timer
1872 Prescaler definitions (SDRAM timing)
1874 - CFG_I2C_UCODE_PATCH, CFG_I2C_DPMEM_OFFSET [0x1FC0]:
1875 enable I2C microcode relocation patch (MPC8xx);
1876 define relocation offset in DPRAM [DSP2]
1878 - CFG_SPI_UCODE_PATCH, CFG_SPI_DPMEM_OFFSET [0x1FC0]:
1879 enable SPI microcode relocation patch (MPC8xx);
1880 define relocation offset in DPRAM [SCC4]
1883 Use OSCM clock mode on MBX8xx board. Be careful,
1884 wrong setting might damage your board. Read
1885 doc/README.MBX before setting this variable!
1887 - CFG_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only)
1888 Offset of the bootmode word in DPRAM used by post
1889 (Power On Self Tests). This definition overrides
1890 #define'd default value in commproc.h resp.
1893 - CFG_PCI_SLV_MEM_LOCAL, CFG_PCI_SLV_MEM_BUS, CFG_PICMR0_MASK_ATTRIB,
1894 CFG_PCI_MSTR0_LOCAL, CFG_PCIMSK0_MASK, CFG_PCI_MSTR1_LOCAL,
1895 CFG_PCIMSK1_MASK, CFG_PCI_MSTR_MEM_LOCAL, CFG_PCI_MSTR_MEM_BUS,
1896 CFG_CPU_PCI_MEM_START, CFG_PCI_MSTR_MEM_SIZE, CFG_POCMR0_MASK_ATTRIB,
1897 CFG_PCI_MSTR_MEMIO_LOCAL, CFG_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START,
1898 CFG_PCI_MSTR_MEMIO_SIZE, CFG_POCMR1_MASK_ATTRIB, CFG_PCI_MSTR_IO_LOCAL,
1899 CFG_PCI_MSTR_IO_BUS, CFG_CPU_PCI_IO_START, CFG_PCI_MSTR_IO_SIZE,
1900 CFG_POCMR2_MASK_ATTRIB: (MPC826x only)
1901 Overrides the default PCI memory map in cpu/mpc8260/pci.c if set.
1903 Building the Software:
1904 ======================
1906 Building U-Boot has been tested in native PPC environments (on a
1907 PowerBook G3 running LinuxPPC 2000) and in cross environments
1908 (running RedHat 6.x and 7.x Linux on x86, Solaris 2.6 on a SPARC, and
1911 If you are not using a native PPC environment, it is assumed that you
1912 have the GNU cross compiling tools available in your path and named
1913 with a prefix of "powerpc-linux-". If this is not the case, (e.g. if
1914 you are using Monta Vista's Hard Hat Linux CDK 1.2) you must change
1915 the definition of CROSS_COMPILE in Makefile. For HHL on a 4xx CPU,
1918 CROSS_COMPILE = ppc_4xx-
1921 U-Boot is intended to be simple to build. After installing the
1922 sources you must configure U-Boot for one specific board type. This
1927 where "NAME_config" is the name of one of the existing
1928 configurations; the following names are supported:
1930 ADCIOP_config GTH_config TQM850L_config
1931 ADS860_config IP860_config TQM855L_config
1932 AR405_config IVML24_config TQM860L_config
1933 CANBT_config IVMS8_config WALNUT405_config
1934 CPCI405_config LANTEC_config cogent_common_config
1935 CPCIISER4_config MBX_config cogent_mpc8260_config
1936 CU824_config MBX860T_config cogent_mpc8xx_config
1937 ESTEEM192E_config RPXlite_config hermes_config
1938 ETX094_config RPXsuper_config hymod_config
1939 FADS823_config SM850_config lwmon_config
1940 FADS850SAR_config SPD823TS_config pcu_e_config
1941 FADS860T_config SXNI855T_config rsdproto_config
1942 FPS850L_config Sandpoint8240_config sbc8260_config
1943 GENIETV_config TQM823L_config PIP405_config
1944 GEN860T_config EBONY_config FPS860L_config
1945 ELPT860_config cmi_mpc5xx_config NETVIA_config
1946 at91rm9200dk_config omap1510inn_config MPC8260ADS_config
1947 omap1610inn_config ZPC1900_config
1949 Note: for some board special configuration names may exist; check if
1950 additional information is available from the board vendor; for
1951 instance, the TQM8xxL systems run normally at 50 MHz and use a
1952 SCC for 10baseT ethernet; there are also systems with 80 MHz
1953 CPU clock, and an optional Fast Ethernet module is available
1954 for CPU's with FEC. You can select such additional "features"
1955 when chosing the configuration, i. e.
1958 - will configure for a plain TQM860L, i. e. 50MHz, no FEC
1960 make TQM860L_FEC_config
1961 - will configure for a TQM860L at 50MHz with FEC for ethernet
1963 make TQM860L_80MHz_config
1964 - will configure for a TQM860L at 80 MHz, with normal 10baseT
1967 make TQM860L_FEC_80MHz_config
1968 - will configure for a TQM860L at 80 MHz with FEC for ethernet
1970 make TQM823L_LCD_config
1971 - will configure for a TQM823L with U-Boot console on LCD
1973 make TQM823L_LCD_80MHz_config
1974 - will configure for a TQM823L at 80 MHz with U-Boot console on LCD
1979 Finally, type "make all", and you should get some working U-Boot
1980 images ready for download to / installation on your system:
1982 - "u-boot.bin" is a raw binary image
1983 - "u-boot" is an image in ELF binary format
1984 - "u-boot.srec" is in Motorola S-Record format
1987 Please be aware that the Makefiles assume you are using GNU make, so
1988 for instance on NetBSD you might need to use "gmake" instead of
1992 If the system board that you have is not listed, then you will need
1993 to port U-Boot to your hardware platform. To do this, follow these
1996 1. Add a new configuration option for your board to the toplevel
1997 "Makefile" and to the "MAKEALL" script, using the existing
1998 entries as examples. Note that here and at many other places
1999 boards and other names are listed in alphabetical sort order. Please
2001 2. Create a new directory to hold your board specific code. Add any
2002 files you need. In your board directory, you will need at least
2003 the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds".
2004 3. Create a new configuration file "include/configs/<board>.h" for
2006 3. If you're porting U-Boot to a new CPU, then also create a new
2007 directory to hold your CPU specific code. Add any files you need.
2008 4. Run "make <board>_config" with your new name.
2009 5. Type "make", and you should get a working "u-boot.srec" file
2010 to be installed on your target system.
2011 6. Debug and solve any problems that might arise.
2012 [Of course, this last step is much harder than it sounds.]
2015 Testing of U-Boot Modifications, Ports to New Hardware, etc.:
2016 ==============================================================
2018 If you have modified U-Boot sources (for instance added a new board
2019 or support for new devices, a new CPU, etc.) you are expected to
2020 provide feedback to the other developers. The feedback normally takes
2021 the form of a "patch", i. e. a context diff against a certain (latest
2022 official or latest in CVS) version of U-Boot sources.
2024 But before you submit such a patch, please verify that your modifi-
2025 cation did not break existing code. At least make sure that *ALL* of
2026 the supported boards compile WITHOUT ANY compiler warnings. To do so,
2027 just run the "MAKEALL" script, which will configure and build U-Boot
2028 for ALL supported system. Be warned, this will take a while. You can
2029 select which (cross) compiler to use by passing a `CROSS_COMPILE'
2030 environment variable to the script, i. e. to use the cross tools from
2031 MontaVista's Hard Hat Linux you can type
2033 CROSS_COMPILE=ppc_8xx- MAKEALL
2035 or to build on a native PowerPC system you can type
2037 CROSS_COMPILE=' ' MAKEALL
2039 See also "U-Boot Porting Guide" below.
2042 Monitor Commands - Overview:
2043 ============================
2045 go - start application at address 'addr'
2046 run - run commands in an environment variable
2047 bootm - boot application image from memory
2048 bootp - boot image via network using BootP/TFTP protocol
2049 tftpboot- boot image via network using TFTP protocol
2050 and env variables "ipaddr" and "serverip"
2051 (and eventually "gatewayip")
2052 rarpboot- boot image via network using RARP/TFTP protocol
2053 diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
2054 loads - load S-Record file over serial line
2055 loadb - load binary file over serial line (kermit mode)
2057 mm - memory modify (auto-incrementing)
2058 nm - memory modify (constant address)
2059 mw - memory write (fill)
2061 cmp - memory compare
2062 crc32 - checksum calculation
2063 imd - i2c memory display
2064 imm - i2c memory modify (auto-incrementing)
2065 inm - i2c memory modify (constant address)
2066 imw - i2c memory write (fill)
2067 icrc32 - i2c checksum calculation
2068 iprobe - probe to discover valid I2C chip addresses
2069 iloop - infinite loop on address range
2070 isdram - print SDRAM configuration information
2071 sspi - SPI utility commands
2072 base - print or set address offset
2073 printenv- print environment variables
2074 setenv - set environment variables
2075 saveenv - save environment variables to persistent storage
2076 protect - enable or disable FLASH write protection
2077 erase - erase FLASH memory
2078 flinfo - print FLASH memory information
2079 bdinfo - print Board Info structure
2080 iminfo - print header information for application image
2081 coninfo - print console devices and informations
2082 ide - IDE sub-system
2083 loop - infinite loop on address range
2084 mtest - simple RAM test
2085 icache - enable or disable instruction cache
2086 dcache - enable or disable data cache
2087 reset - Perform RESET of the CPU
2088 echo - echo args to console
2089 version - print monitor version
2090 help - print online help
2091 ? - alias for 'help'
2094 Monitor Commands - Detailed Description:
2095 ========================================
2099 For now: just type "help <command>".
2102 Environment Variables:
2103 ======================
2105 U-Boot supports user configuration using Environment Variables which
2106 can be made persistent by saving to Flash memory.
2108 Environment Variables are set using "setenv", printed using
2109 "printenv", and saved to Flash using "saveenv". Using "setenv"
2110 without a value can be used to delete a variable from the
2111 environment. As long as you don't save the environment you are
2112 working with an in-memory copy. In case the Flash area containing the
2113 environment is erased by accident, a default environment is provided.
2115 Some configuration options can be set using Environment Variables:
2117 baudrate - see CONFIG_BAUDRATE
2119 bootdelay - see CONFIG_BOOTDELAY
2121 bootcmd - see CONFIG_BOOTCOMMAND
2123 bootargs - Boot arguments when booting an RTOS image
2125 bootfile - Name of the image to load with TFTP
2127 autoload - if set to "no" (any string beginning with 'n'),
2128 "bootp" will just load perform a lookup of the
2129 configuration from the BOOTP server, but not try to
2130 load any image using TFTP
2132 autostart - if set to "yes", an image loaded using the "bootp",
2133 "rarpboot", "tftpboot" or "diskboot" commands will
2134 be automatically started (by internally calling
2137 If set to "no", a standalone image passed to the
2138 "bootm" command will be copied to the load address
2139 (and eventually uncompressed), but NOT be started.
2140 This can be used to load and uncompress arbitrary
2143 initrd_high - restrict positioning of initrd images:
2144 If this variable is not set, initrd images will be
2145 copied to the highest possible address in RAM; this
2146 is usually what you want since it allows for
2147 maximum initrd size. If for some reason you want to
2148 make sure that the initrd image is loaded below the
2149 CFG_BOOTMAPSZ limit, you can set this environment
2150 variable to a value of "no" or "off" or "0".
2151 Alternatively, you can set it to a maximum upper
2152 address to use (U-Boot will still check that it
2153 does not overwrite the U-Boot stack and data).
2155 For instance, when you have a system with 16 MB
2156 RAM, and want to reserve 4 MB from use by Linux,
2157 you can do this by adding "mem=12M" to the value of
2158 the "bootargs" variable. However, now you must make
2159 sure that the initrd image is placed in the first
2160 12 MB as well - this can be done with
2162 setenv initrd_high 00c00000
2164 If you set initrd_high to 0xFFFFFFFF, this is an
2165 indication to U-Boot that all addresses are legal
2166 for the Linux kernel, including addresses in flash
2167 memory. In this case U-Boot will NOT COPY the
2168 ramdisk at all. This may be useful to reduce the
2169 boot time on your system, but requires that this
2170 feature is supported by your Linux kernel.
2172 ipaddr - IP address; needed for tftpboot command
2174 loadaddr - Default load address for commands like "bootp",
2175 "rarpboot", "tftpboot", "loadb" or "diskboot"
2177 loads_echo - see CONFIG_LOADS_ECHO
2179 serverip - TFTP server IP address; needed for tftpboot command
2181 bootretry - see CONFIG_BOOT_RETRY_TIME
2183 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
2185 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
2188 The following environment variables may be used and automatically
2189 updated by the network boot commands ("bootp" and "rarpboot"),
2190 depending the information provided by your boot server:
2192 bootfile - see above
2193 dnsip - IP address of your Domain Name Server
2194 dnsip2 - IP address of your secondary Domain Name Server
2195 gatewayip - IP address of the Gateway (Router) to use
2196 hostname - Target hostname
2198 netmask - Subnet Mask
2199 rootpath - Pathname of the root filesystem on the NFS server
2200 serverip - see above
2203 There are two special Environment Variables:
2205 serial# - contains hardware identification information such
2206 as type string and/or serial number
2207 ethaddr - Ethernet address
2209 These variables can be set only once (usually during manufacturing of
2210 the board). U-Boot refuses to delete or overwrite these variables
2211 once they have been set once.
2214 Further special Environment Variables:
2216 ver - Contains the U-Boot version string as printed
2217 with the "version" command. This variable is
2218 readonly (see CONFIG_VERSION_VARIABLE).
2221 Please note that changes to some configuration parameters may take
2222 only effect after the next boot (yes, that's just like Windoze :-).
2225 Command Line Parsing:
2226 =====================
2228 There are two different command line parsers available with U-Boot:
2229 the old "simple" one, and the much more powerful "hush" shell:
2231 Old, simple command line parser:
2232 --------------------------------
2234 - supports environment variables (through setenv / saveenv commands)
2235 - several commands on one line, separated by ';'
2236 - variable substitution using "... $(name) ..." syntax
2237 - special characters ('$', ';') can be escaped by prefixing with '\',
2239 setenv bootcmd bootm \$(address)
2240 - You can also escape text by enclosing in single apostrophes, for example:
2241 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
2246 - similar to Bourne shell, with control structures like
2247 if...then...else...fi, for...do...done; while...do...done,
2248 until...do...done, ...
2249 - supports environment ("global") variables (through setenv / saveenv
2250 commands) and local shell variables (through standard shell syntax
2251 "name=value"); only environment variables can be used with "run"
2257 (1) If a command line (or an environment variable executed by a "run"
2258 command) contains several commands separated by semicolon, and
2259 one of these commands fails, then the remaining commands will be
2262 (2) If you execute several variables with one call to run (i. e.
2263 calling run with a list af variables as arguments), any failing
2264 command will cause "run" to terminate, i. e. the remaining
2265 variables are not executed.
2267 Note for Redundant Ethernet Interfaces:
2268 =======================================
2270 Some boards come with redundant ethernet interfaces; U-Boot supports
2271 such configurations and is capable of automatic selection of a
2272 "working" interface when needed. MAC assignment works as follows:
2274 Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
2275 MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
2276 "eth1addr" (=>eth1), "eth2addr", ...
2278 If the network interface stores some valid MAC address (for instance
2279 in SROM), this is used as default address if there is NO correspon-
2280 ding setting in the environment; if the corresponding environment
2281 variable is set, this overrides the settings in the card; that means:
2283 o If the SROM has a valid MAC address, and there is no address in the
2284 environment, the SROM's address is used.
2286 o If there is no valid address in the SROM, and a definition in the
2287 environment exists, then the value from the environment variable is
2290 o If both the SROM and the environment contain a MAC address, and
2291 both addresses are the same, this MAC address is used.
2293 o If both the SROM and the environment contain a MAC address, and the
2294 addresses differ, the value from the environment is used and a
2297 o If neither SROM nor the environment contain a MAC address, an error
2304 The "boot" commands of this monitor operate on "image" files which
2305 can be basicly anything, preceeded by a special header; see the
2306 definitions in include/image.h for details; basicly, the header
2307 defines the following image properties:
2309 * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
2310 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
2311 LynxOS, pSOS, QNX, RTEMS, ARTOS;
2312 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, ARTOS, LynxOS).
2313 * Target CPU Architecture (Provisions for Alpha, ARM, Intel x86,
2314 IA64, MIPS, MIPS, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
2315 Currently supported: PowerPC).
2316 * Compression Type (uncompressed, gzip, bzip2)
2322 The header is marked by a special Magic Number, and both the header
2323 and the data portions of the image are secured against corruption by
2330 Although U-Boot should support any OS or standalone application
2331 easily, the main focus has always been on Linux during the design of
2334 U-Boot includes many features that so far have been part of some
2335 special "boot loader" code within the Linux kernel. Also, any
2336 "initrd" images to be used are no longer part of one big Linux image;
2337 instead, kernel and "initrd" are separate images. This implementation
2338 serves several purposes:
2340 - the same features can be used for other OS or standalone
2341 applications (for instance: using compressed images to reduce the
2342 Flash memory footprint)
2344 - it becomes much easier to port new Linux kernel versions because
2345 lots of low-level, hardware dependent stuff are done by U-Boot
2347 - the same Linux kernel image can now be used with different "initrd"
2348 images; of course this also means that different kernel images can
2349 be run with the same "initrd". This makes testing easier (you don't
2350 have to build a new "zImage.initrd" Linux image when you just
2351 change a file in your "initrd"). Also, a field-upgrade of the
2352 software is easier now.
2358 Porting Linux to U-Boot based systems:
2359 ---------------------------------------
2361 U-Boot cannot save you from doing all the necessary modifications to
2362 configure the Linux device drivers for use with your target hardware
2363 (no, we don't intend to provide a full virtual machine interface to
2366 But now you can ignore ALL boot loader code (in arch/ppc/mbxboot).
2368 Just make sure your machine specific header file (for instance
2369 include/asm-ppc/tqm8xx.h) includes the same definition of the Board
2370 Information structure as we define in include/u-boot.h, and make
2371 sure that your definition of IMAP_ADDR uses the same value as your
2372 U-Boot configuration in CFG_IMMR.
2375 Configuring the Linux kernel:
2376 -----------------------------
2378 No specific requirements for U-Boot. Make sure you have some root
2379 device (initial ramdisk, NFS) for your target system.
2382 Building a Linux Image:
2383 -----------------------
2385 With U-Boot, "normal" build targets like "zImage" or "bzImage" are
2386 not used. If you use recent kernel source, a new build target
2387 "uImage" will exist which automatically builds an image usable by
2388 U-Boot. Most older kernels also have support for a "pImage" target,
2389 which was introduced for our predecessor project PPCBoot and uses a
2390 100% compatible format.
2399 The "uImage" build target uses a special tool (in 'tools/mkimage') to
2400 encapsulate a compressed Linux kernel image with header information,
2401 CRC32 checksum etc. for use with U-Boot. This is what we are doing:
2403 * build a standard "vmlinux" kernel image (in ELF binary format):
2405 * convert the kernel into a raw binary image:
2407 ${CROSS_COMPILE}-objcopy -O binary \
2408 -R .note -R .comment \
2409 -S vmlinux linux.bin
2411 * compress the binary image:
2415 * package compressed binary image for U-Boot:
2417 mkimage -A ppc -O linux -T kernel -C gzip \
2418 -a 0 -e 0 -n "Linux Kernel Image" \
2419 -d linux.bin.gz uImage
2422 The "mkimage" tool can also be used to create ramdisk images for use
2423 with U-Boot, either separated from the Linux kernel image, or
2424 combined into one file. "mkimage" encapsulates the images with a 64
2425 byte header containing information about target architecture,
2426 operating system, image type, compression method, entry points, time
2427 stamp, CRC32 checksums, etc.
2429 "mkimage" can be called in two ways: to verify existing images and
2430 print the header information, or to build new images.
2432 In the first form (with "-l" option) mkimage lists the information
2433 contained in the header of an existing U-Boot image; this includes
2434 checksum verification:
2436 tools/mkimage -l image
2437 -l ==> list image header information
2439 The second form (with "-d" option) is used to build a U-Boot image
2440 from a "data file" which is used as image payload:
2442 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
2443 -n name -d data_file image
2444 -A ==> set architecture to 'arch'
2445 -O ==> set operating system to 'os'
2446 -T ==> set image type to 'type'
2447 -C ==> set compression type 'comp'
2448 -a ==> set load address to 'addr' (hex)
2449 -e ==> set entry point to 'ep' (hex)
2450 -n ==> set image name to 'name'
2451 -d ==> use image data from 'datafile'
2453 Right now, all Linux kernels use the same load address (0x00000000),
2454 but the entry point address depends on the kernel version:
2456 - 2.2.x kernels have the entry point at 0x0000000C,
2457 - 2.3.x and later kernels have the entry point at 0x00000000.
2459 So a typical call to build a U-Boot image would read:
2461 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
2462 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
2463 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux.gz \
2464 > examples/uImage.TQM850L
2465 Image Name: 2.4.4 kernel for TQM850L
2466 Created: Wed Jul 19 02:34:59 2000
2467 Image Type: PowerPC Linux Kernel Image (gzip compressed)
2468 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
2469 Load Address: 0x00000000
2470 Entry Point: 0x00000000
2472 To verify the contents of the image (or check for corruption):
2474 -> tools/mkimage -l examples/uImage.TQM850L
2475 Image Name: 2.4.4 kernel for TQM850L
2476 Created: Wed Jul 19 02:34:59 2000
2477 Image Type: PowerPC Linux Kernel Image (gzip compressed)
2478 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
2479 Load Address: 0x00000000
2480 Entry Point: 0x00000000
2482 NOTE: for embedded systems where boot time is critical you can trade
2483 speed for memory and install an UNCOMPRESSED image instead: this
2484 needs more space in Flash, but boots much faster since it does not
2485 need to be uncompressed:
2487 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux.gz
2488 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
2489 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
2490 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux \
2491 > examples/uImage.TQM850L-uncompressed
2492 Image Name: 2.4.4 kernel for TQM850L
2493 Created: Wed Jul 19 02:34:59 2000
2494 Image Type: PowerPC Linux Kernel Image (uncompressed)
2495 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
2496 Load Address: 0x00000000
2497 Entry Point: 0x00000000
2500 Similar you can build U-Boot images from a 'ramdisk.image.gz' file
2501 when your kernel is intended to use an initial ramdisk:
2503 -> tools/mkimage -n 'Simple Ramdisk Image' \
2504 > -A ppc -O linux -T ramdisk -C gzip \
2505 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
2506 Image Name: Simple Ramdisk Image
2507 Created: Wed Jan 12 14:01:50 2000
2508 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
2509 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
2510 Load Address: 0x00000000
2511 Entry Point: 0x00000000
2514 Installing a Linux Image:
2515 -------------------------
2517 To downloading a U-Boot image over the serial (console) interface,
2518 you must convert the image to S-Record format:
2520 objcopy -I binary -O srec examples/image examples/image.srec
2522 The 'objcopy' does not understand the information in the U-Boot
2523 image header, so the resulting S-Record file will be relative to
2524 address 0x00000000. To load it to a given address, you need to
2525 specify the target address as 'offset' parameter with the 'loads'
2528 Example: install the image to address 0x40100000 (which on the
2529 TQM8xxL is in the first Flash bank):
2531 => erase 40100000 401FFFFF
2537 ## Ready for S-Record download ...
2538 ~>examples/image.srec
2539 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
2541 15989 15990 15991 15992
2542 [file transfer complete]
2544 ## Start Addr = 0x00000000
2547 You can check the success of the download using the 'iminfo' command;
2548 this includes a checksum verification so you can be sure no data
2549 corruption happened:
2553 ## Checking Image at 40100000 ...
2554 Image Name: 2.2.13 for initrd on TQM850L
2555 Image Type: PowerPC Linux Kernel Image (gzip compressed)
2556 Data Size: 335725 Bytes = 327 kB = 0 MB
2557 Load Address: 00000000
2558 Entry Point: 0000000c
2559 Verifying Checksum ... OK
2565 The "bootm" command is used to boot an application that is stored in
2566 memory (RAM or Flash). In case of a Linux kernel image, the contents
2567 of the "bootargs" environment variable is passed to the kernel as
2568 parameters. You can check and modify this variable using the
2569 "printenv" and "setenv" commands:
2572 => printenv bootargs
2573 bootargs=root=/dev/ram
2575 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
2577 => printenv bootargs
2578 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
2581 ## Booting Linux kernel at 40020000 ...
2582 Image Name: 2.2.13 for NFS on TQM850L
2583 Image Type: PowerPC Linux Kernel Image (gzip compressed)
2584 Data Size: 381681 Bytes = 372 kB = 0 MB
2585 Load Address: 00000000
2586 Entry Point: 0000000c
2587 Verifying Checksum ... OK
2588 Uncompressing Kernel Image ... OK
2589 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
2590 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
2591 time_init: decrementer frequency = 187500000/60
2592 Calibrating delay loop... 49.77 BogoMIPS
2593 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
2596 If you want to boot a Linux kernel with initial ram disk, you pass
2597 the memory addresses of both the kernel and the initrd image (PPBCOOT
2598 format!) to the "bootm" command:
2600 => imi 40100000 40200000
2602 ## Checking Image at 40100000 ...
2603 Image Name: 2.2.13 for initrd on TQM850L
2604 Image Type: PowerPC Linux Kernel Image (gzip compressed)
2605 Data Size: 335725 Bytes = 327 kB = 0 MB
2606 Load Address: 00000000
2607 Entry Point: 0000000c
2608 Verifying Checksum ... OK
2610 ## Checking Image at 40200000 ...
2611 Image Name: Simple Ramdisk Image
2612 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
2613 Data Size: 566530 Bytes = 553 kB = 0 MB
2614 Load Address: 00000000
2615 Entry Point: 00000000
2616 Verifying Checksum ... OK
2618 => bootm 40100000 40200000
2619 ## Booting Linux kernel at 40100000 ...
2620 Image Name: 2.2.13 for initrd on TQM850L
2621 Image Type: PowerPC Linux Kernel Image (gzip compressed)
2622 Data Size: 335725 Bytes = 327 kB = 0 MB
2623 Load Address: 00000000
2624 Entry Point: 0000000c
2625 Verifying Checksum ... OK
2626 Uncompressing Kernel Image ... OK
2627 ## Loading RAMDisk Image at 40200000 ...
2628 Image Name: Simple Ramdisk Image
2629 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
2630 Data Size: 566530 Bytes = 553 kB = 0 MB
2631 Load Address: 00000000
2632 Entry Point: 00000000
2633 Verifying Checksum ... OK
2634 Loading Ramdisk ... OK
2635 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
2636 Boot arguments: root=/dev/ram
2637 time_init: decrementer frequency = 187500000/60
2638 Calibrating delay loop... 49.77 BogoMIPS
2640 RAMDISK: Compressed image found at block 0
2641 VFS: Mounted root (ext2 filesystem).
2645 More About U-Boot Image Types:
2646 ------------------------------
2648 U-Boot supports the following image types:
2650 "Standalone Programs" are directly runnable in the environment
2651 provided by U-Boot; it is expected that (if they behave
2652 well) you can continue to work in U-Boot after return from
2653 the Standalone Program.
2654 "OS Kernel Images" are usually images of some Embedded OS which
2655 will take over control completely. Usually these programs
2656 will install their own set of exception handlers, device
2657 drivers, set up the MMU, etc. - this means, that you cannot
2658 expect to re-enter U-Boot except by resetting the CPU.
2659 "RAMDisk Images" are more or less just data blocks, and their
2660 parameters (address, size) are passed to an OS kernel that is
2662 "Multi-File Images" contain several images, typically an OS
2663 (Linux) kernel image and one or more data images like
2664 RAMDisks. This construct is useful for instance when you want
2665 to boot over the network using BOOTP etc., where the boot
2666 server provides just a single image file, but you want to get
2667 for instance an OS kernel and a RAMDisk image.
2669 "Multi-File Images" start with a list of image sizes, each
2670 image size (in bytes) specified by an "uint32_t" in network
2671 byte order. This list is terminated by an "(uint32_t)0".
2672 Immediately after the terminating 0 follow the images, one by
2673 one, all aligned on "uint32_t" boundaries (size rounded up to
2674 a multiple of 4 bytes).
2676 "Firmware Images" are binary images containing firmware (like
2677 U-Boot or FPGA images) which usually will be programmed to
2680 "Script files" are command sequences that will be executed by
2681 U-Boot's command interpreter; this feature is especially
2682 useful when you configure U-Boot to use a real shell (hush)
2683 as command interpreter.
2689 One of the features of U-Boot is that you can dynamically load and
2690 run "standalone" applications, which can use some resources of
2691 U-Boot like console I/O functions or interrupt services.
2693 Two simple examples are included with the sources:
2698 'examples/hello_world.c' contains a small "Hello World" Demo
2699 application; it is automatically compiled when you build U-Boot.
2700 It's configured to run at address 0x00040004, so you can play with it
2704 ## Ready for S-Record download ...
2705 ~>examples/hello_world.srec
2706 1 2 3 4 5 6 7 8 9 10 11 ...
2707 [file transfer complete]
2709 ## Start Addr = 0x00040004
2711 => go 40004 Hello World! This is a test.
2712 ## Starting application at 0x00040004 ...
2723 Hit any key to exit ...
2725 ## Application terminated, rc = 0x0
2727 Another example, which demonstrates how to register a CPM interrupt
2728 handler with the U-Boot code, can be found in 'examples/timer.c'.
2729 Here, a CPM timer is set up to generate an interrupt every second.
2730 The interrupt service routine is trivial, just printing a '.'
2731 character, but this is just a demo program. The application can be
2732 controlled by the following keys:
2734 ? - print current values og the CPM Timer registers
2735 b - enable interrupts and start timer
2736 e - stop timer and disable interrupts
2737 q - quit application
2740 ## Ready for S-Record download ...
2741 ~>examples/timer.srec
2742 1 2 3 4 5 6 7 8 9 10 11 ...
2743 [file transfer complete]
2745 ## Start Addr = 0x00040004
2748 ## Starting application at 0x00040004 ...
2751 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
2754 [q, b, e, ?] Set interval 1000000 us
2757 [q, b, e, ?] ........
2758 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
2761 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
2764 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
2767 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
2769 [q, b, e, ?] ...Stopping timer
2771 [q, b, e, ?] ## Application terminated, rc = 0x0
2777 Over time, many people have reported problems when trying to use the
2778 "minicom" terminal emulation program for serial download. I (wd)
2779 consider minicom to be broken, and recommend not to use it. Under
2780 Unix, I recommend to use C-Kermit for general purpose use (and
2781 especially for kermit binary protocol download ("loadb" command), and
2782 use "cu" for S-Record download ("loads" command).
2784 Nevertheless, if you absolutely want to use it try adding this
2785 configuration to your "File transfer protocols" section:
2787 Name Program Name U/D FullScr IO-Red. Multi
2788 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
2789 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
2795 Starting at version 0.9.2, U-Boot supports NetBSD both as host
2796 (build U-Boot) and target system (boots NetBSD/mpc8xx).
2798 Building requires a cross environment; it is known to work on
2799 NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
2800 need gmake since the Makefiles are not compatible with BSD make).
2801 Note that the cross-powerpc package does not install include files;
2802 attempting to build U-Boot will fail because <machine/ansi.h> is
2803 missing. This file has to be installed and patched manually:
2805 # cd /usr/pkg/cross/powerpc-netbsd/include
2807 # ln -s powerpc machine
2808 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
2809 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
2811 Native builds *don't* work due to incompatibilities between native
2812 and U-Boot include files.
2814 Booting assumes that (the first part of) the image booted is a
2815 stage-2 loader which in turn loads and then invokes the kernel
2816 proper. Loader sources will eventually appear in the NetBSD source
2817 tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
2818 meantime, send mail to bruno@exet-ag.de and/or wd@denx.de for
2822 Implementation Internals:
2823 =========================
2825 The following is not intended to be a complete description of every
2826 implementation detail. However, it should help to understand the
2827 inner workings of U-Boot and make it easier to port it to custom
2831 Initial Stack, Global Data:
2832 ---------------------------
2834 The implementation of U-Boot is complicated by the fact that U-Boot
2835 starts running out of ROM (flash memory), usually without access to
2836 system RAM (because the memory controller is not initialized yet).
2837 This means that we don't have writable Data or BSS segments, and BSS
2838 is not initialized as zero. To be able to get a C environment working
2839 at all, we have to allocate at least a minimal stack. Implementation
2840 options for this are defined and restricted by the CPU used: Some CPU
2841 models provide on-chip memory (like the IMMR area on MPC8xx and
2842 MPC826x processors), on others (parts of) the data cache can be
2843 locked as (mis-) used as memory, etc.
2845 Chris Hallinan posted a good summary of these issues to the
2846 u-boot-users mailing list:
2848 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
2849 From: "Chris Hallinan" <clh@net1plus.com>
2850 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
2853 Correct me if I'm wrong, folks, but the way I understand it
2854 is this: Using DCACHE as initial RAM for Stack, etc, does not
2855 require any physical RAM backing up the cache. The cleverness
2856 is that the cache is being used as a temporary supply of
2857 necessary storage before the SDRAM controller is setup. It's
2858 beyond the scope of this list to expain the details, but you
2859 can see how this works by studying the cache architecture and
2860 operation in the architecture and processor-specific manuals.
2862 OCM is On Chip Memory, which I believe the 405GP has 4K. It
2863 is another option for the system designer to use as an
2864 initial stack/ram area prior to SDRAM being available. Either
2865 option should work for you. Using CS 4 should be fine if your
2866 board designers haven't used it for something that would
2867 cause you grief during the initial boot! It is frequently not
2870 CFG_INIT_RAM_ADDR should be somewhere that won't interfere
2871 with your processor/board/system design. The default value
2872 you will find in any recent u-boot distribution in
2873 Walnut405.h should work for you. I'd set it to a value larger
2874 than your SDRAM module. If you have a 64MB SDRAM module, set
2875 it above 400_0000. Just make sure your board has no resources
2876 that are supposed to respond to that address! That code in
2877 start.S has been around a while and should work as is when
2878 you get the config right.
2883 It is essential to remember this, since it has some impact on the C
2884 code for the initialization procedures:
2886 * Initialized global data (data segment) is read-only. Do not attempt
2889 * Do not use any unitialized global data (or implicitely initialized
2890 as zero data - BSS segment) at all - this is undefined, initiali-
2891 zation is performed later (when relocating to RAM).
2893 * Stack space is very limited. Avoid big data buffers or things like
2896 Having only the stack as writable memory limits means we cannot use
2897 normal global data to share information beween the code. But it
2898 turned out that the implementation of U-Boot can be greatly
2899 simplified by making a global data structure (gd_t) available to all
2900 functions. We could pass a pointer to this data as argument to _all_
2901 functions, but this would bloat the code. Instead we use a feature of
2902 the GCC compiler (Global Register Variables) to share the data: we
2903 place a pointer (gd) to the global data into a register which we
2904 reserve for this purpose.
2906 When choosing a register for such a purpose we are restricted by the
2907 relevant (E)ABI specifications for the current architecture, and by
2908 GCC's implementation.
2910 For PowerPC, the following registers have specific use:
2913 R3-R4: parameter passing and return values
2914 R5-R10: parameter passing
2915 R13: small data area pointer
2919 (U-Boot also uses R14 as internal GOT pointer.)
2921 ==> U-Boot will use R29 to hold a pointer to the global data
2923 Note: on PPC, we could use a static initializer (since the
2924 address of the global data structure is known at compile time),
2925 but it turned out that reserving a register results in somewhat
2926 smaller code - although the code savings are not that big (on
2927 average for all boards 752 bytes for the whole U-Boot image,
2928 624 text + 127 data).
2930 On ARM, the following registers are used:
2932 R0: function argument word/integer result
2933 R1-R3: function argument word
2935 R10: stack limit (used only if stack checking if enabled)
2936 R11: argument (frame) pointer
2937 R12: temporary workspace
2940 R15: program counter
2942 ==> U-Boot will use R8 to hold a pointer to the global data
2948 U-Boot runs in system state and uses physical addresses, i.e. the
2949 MMU is not used either for address mapping nor for memory protection.
2951 The available memory is mapped to fixed addresses using the memory
2952 controller. In this process, a contiguous block is formed for each
2953 memory type (Flash, SDRAM, SRAM), even when it consists of several
2954 physical memory banks.
2956 U-Boot is installed in the first 128 kB of the first Flash bank (on
2957 TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
2958 booting and sizing and initializing DRAM, the code relocates itself
2959 to the upper end of DRAM. Immediately below the U-Boot code some
2960 memory is reserved for use by malloc() [see CFG_MALLOC_LEN
2961 configuration setting]. Below that, a structure with global Board
2962 Info data is placed, followed by the stack (growing downward).
2964 Additionally, some exception handler code is copied to the low 8 kB
2965 of DRAM (0x00000000 ... 0x00001FFF).
2967 So a typical memory configuration with 16 MB of DRAM could look like
2970 0x0000 0000 Exception Vector code
2973 0x0000 2000 Free for Application Use
2979 0x00FB FF20 Monitor Stack (Growing downward)
2980 0x00FB FFAC Board Info Data and permanent copy of global data
2981 0x00FC 0000 Malloc Arena
2984 0x00FE 0000 RAM Copy of Monitor Code
2985 ... eventually: LCD or video framebuffer
2986 ... eventually: pRAM (Protected RAM - unchanged by reset)
2987 0x00FF FFFF [End of RAM]
2990 System Initialization:
2991 ----------------------
2993 In the reset configuration, U-Boot starts at the reset entry point
2994 (on most PowerPC systens at address 0x00000100). Because of the reset
2995 configuration for CS0# this is a mirror of the onboard Flash memory.
2996 To be able to re-map memory U-Boot then jumps to its link address.
2997 To be able to implement the initialization code in C, a (small!)
2998 initial stack is set up in the internal Dual Ported RAM (in case CPUs
2999 which provide such a feature like MPC8xx or MPC8260), or in a locked
3000 part of the data cache. After that, U-Boot initializes the CPU core,
3001 the caches and the SIU.
3003 Next, all (potentially) available memory banks are mapped using a
3004 preliminary mapping. For example, we put them on 512 MB boundaries
3005 (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
3006 on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
3007 programmed for SDRAM access. Using the temporary configuration, a
3008 simple memory test is run that determines the size of the SDRAM
3011 When there is more than one SDRAM bank, and the banks are of
3012 different size, the largest is mapped first. For equal size, the first
3013 bank (CS2#) is mapped first. The first mapping is always for address
3014 0x00000000, with any additional banks following immediately to create
3015 contiguous memory starting from 0.
3017 Then, the monitor installs itself at the upper end of the SDRAM area
3018 and allocates memory for use by malloc() and for the global Board
3019 Info data; also, the exception vector code is copied to the low RAM
3020 pages, and the final stack is set up.
3022 Only after this relocation will you have a "normal" C environment;
3023 until that you are restricted in several ways, mostly because you are
3024 running from ROM, and because the code will have to be relocated to a
3028 U-Boot Porting Guide:
3029 ----------------------
3031 [Based on messages by Jerry Van Baren in the U-Boot-Users mailing
3035 int main (int argc, char *argv[])
3037 sighandler_t no_more_time;
3039 signal (SIGALRM, no_more_time);
3040 alarm (PROJECT_DEADLINE - toSec (3 * WEEK));
3042 if (available_money > available_manpower) {
3043 pay consultant to port U-Boot;
3047 Download latest U-Boot source;
3049 Subscribe to u-boot-users mailing list;
3052 email ("Hi, I am new to U-Boot, how do I get started?");
3056 Read the README file in the top level directory;
3057 Read http://www.denx.de/re/DPLG.html
3058 Read the source, Luke;
3061 if (available_money > toLocalCurrency ($2500)) {
3064 Add a lot of aggravation and time;
3067 Create your own board support subdirectory;
3069 Create your own board config file;
3073 Add / modify source code;
3077 email ("Hi, I am having problems...");
3079 Send patch file to Wolfgang;
3084 void no_more_time (int sig)
3093 All contributions to U-Boot should conform to the Linux kernel
3094 coding style; see the file "Documentation/CodingStyle" in your Linux
3095 kernel source directory.
3097 Please note that U-Boot is implemented in C (and to some small parts
3098 in Assembler); no C++ is used, so please do not use C++ style
3099 comments (//) in your code.
3101 Submissions which do not conform to the standards may be returned
3102 with a request to reformat the changes.
3108 Since the number of patches for U-Boot is growing, we need to
3109 establish some rules. Submissions which do not conform to these rules
3110 may be rejected, even when they contain important and valuable stuff.
3113 When you send a patch, please include the following information with
3116 * For bug fixes: a description of the bug and how your patch fixes
3117 this bug. Please try to include a way of demonstrating that the
3118 patch actually fixes something.
3120 * For new features: a description of the feature and your
3123 * A CHANGELOG entry as plaintext (separate from the patch)
3125 * For major contributions, your entry to the CREDITS file
3127 * When you add support for a new board, don't forget to add this
3128 board to the MAKEALL script, too.
3130 * If your patch adds new configuration options, don't forget to
3131 document these in the README file.
3133 * The patch itself. If you are accessing the CVS repository use "cvs
3134 update; cvs diff -puRN"; else, use "diff -purN OLD NEW". If your
3135 version of diff does not support these options, then get the latest
3136 version of GNU diff.
3138 The current directory when running this command shall be the top
3139 level directory of the U-Boot source tree, or it's parent directory
3140 (i. e. please make sure that your patch includes sufficient
3141 directory information for the affected files).
3143 We accept patches as plain text, MIME attachments or as uuencoded
3146 * If one logical set of modifications affects or creates several
3147 files, all these changes shall be submitted in a SINGLE patch file.
3149 * Changesets that contain different, unrelated modifications shall be
3150 submitted as SEPARATE patches, one patch per changeset.
3155 * Before sending the patch, run the MAKEALL script on your patched
3156 source tree and make sure that no errors or warnings are reported
3157 for any of the boards.
3159 * Keep your modifications to the necessary minimum: A patch
3160 containing several unrelated changes or arbitrary reformats will be
3161 returned with a request to re-formatting / split it.
3163 * If you modify existing code, make sure that your new code does not
3164 add to the memory footprint of the code ;-) Small is beautiful!
3165 When adding new features, these should compile conditionally only
3166 (using #ifdef), and the resulting code with the new feature
3167 disabled must not need more memory than the old code without your
projects / platform / kernel / u-boot.git / blob