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/mpc85xx Files specific to Motorola MPC85xx CPUs
150 - cpu/ppc4xx Files specific to IBM 4xx CPUs
153 - board/LEOX/ Files specific to boards manufactured by The LEOX team
154 - board/LEOX/elpt860 Files specific to ELPT860 boards
156 Files specific to RPXClassic boards
157 - board/RPXlite Files specific to RPXlite boards
158 - board/at91rm9200dk Files specific to AT91RM9200DK boards
159 - board/c2mon Files specific to c2mon boards
160 - board/cmi Files specific to cmi boards
161 - board/cogent Files specific to Cogent boards
162 (need further configuration)
163 Files specific to CPCIISER4 boards
164 - board/cpu86 Files specific to CPU86 boards
165 - board/cray/ Files specific to boards manufactured by Cray
166 - board/cray/L1 Files specific to L1 boards
167 - board/cu824 Files specific to CU824 boards
168 - board/ebony Files specific to IBM Ebony board
169 - board/eric Files specific to ERIC boards
170 - board/esd/ Files specific to boards manufactured by ESD
171 - board/esd/adciop Files specific to ADCIOP boards
172 - board/esd/ar405 Files specific to AR405 boards
173 - board/esd/canbt Files specific to CANBT boards
174 - board/esd/cpci405 Files specific to CPCI405 boards
175 - board/esd/cpciiser4 Files specific to CPCIISER4 boards
176 - board/esd/common Common files for ESD boards
177 - board/esd/dasa_sim Files specific to DASA_SIM boards
178 - board/esd/du405 Files specific to DU405 boards
179 - board/esd/ocrtc Files specific to OCRTC boards
180 - board/esd/pci405 Files specific to PCI405 boards
182 Files specific to ESTEEM192E boards
183 - board/etx094 Files specific to ETX_094 boards
185 Files specific to EVB64260 boards
186 - board/fads Files specific to FADS boards
187 - board/flagadm Files specific to FLAGADM boards
188 - board/gen860t Files specific to GEN860T and GEN860T_SC boards
189 - board/genietv Files specific to GENIETV boards
190 - board/gth Files specific to GTH boards
191 - board/hermes Files specific to HERMES boards
192 - board/hymod Files specific to HYMOD boards
193 - board/icu862 Files specific to ICU862 boards
194 - board/ip860 Files specific to IP860 boards
196 Files specific to Interphase4539 boards
197 - board/ivm Files specific to IVMS8/IVML24 boards
198 - board/lantec Files specific to LANTEC boards
199 - board/lwmon Files specific to LWMON boards
200 - board/mbx8xx Files specific to MBX boards
202 Files specific to MPC8260ADS and PQ2FADS-ZU boards
204 Files specific to MPC8540ADS boards
206 Files specific to MPC8560ADS boards
207 - board/mpl/ Files specific to boards manufactured by MPL
208 - board/mpl/common Common files for MPL boards
209 - board/mpl/pip405 Files specific to PIP405 boards
210 - board/mpl/mip405 Files specific to MIP405 boards
211 - board/mpl/vcma9 Files specific to VCMA9 boards
212 - board/musenki Files specific to MUSEKNI boards
213 - board/mvs1 Files specific to MVS1 boards
214 - board/nx823 Files specific to NX823 boards
215 - board/oxc Files specific to OXC boards
217 Files specific to OMAP 1510 Innovator boards
219 Files specific to OMAP 1610 Innovator boards
220 - board/pcippc2 Files specific to PCIPPC2/PCIPPC6 boards
221 - board/pm826 Files specific to PM826 boards
223 Files specific to PPMC8260 boards
225 Files specific to RPXsuper boards
227 Files specific to RSDproto boards
229 Files specific to Sandpoint boards
230 - board/sbc8260 Files specific to SBC8260 boards
231 - board/sacsng Files specific to SACSng boards
232 - board/siemens Files specific to boards manufactured by Siemens AG
233 - board/siemens/CCM Files specific to CCM boards
234 - board/siemens/IAD210 Files specific to IAD210 boards
235 - board/siemens/SCM Files specific to SCM boards
236 - board/siemens/pcu_e Files specific to PCU_E boards
237 - board/sixnet Files specific to SIXNET boards
238 - board/spd8xx Files specific to SPD8xxTS boards
239 - board/tqm8260 Files specific to TQM8260 boards
240 - board/tqm8xx Files specific to TQM8xxL boards
241 - board/w7o Files specific to W7O boards
243 Files specific to Walnut405 boards
244 - board/westel/ Files specific to boards manufactured by Westel Wireless
245 - board/westel/amx860 Files specific to AMX860 boards
246 - board/utx8245 Files specific to UTX8245 boards
247 - board/zpc1900 Files specific to Zephyr Engineering ZPC.1900 board
249 Software Configuration:
250 =======================
252 Configuration is usually done using C preprocessor defines; the
253 rationale behind that is to avoid dead code whenever possible.
255 There are two classes of configuration variables:
257 * Configuration _OPTIONS_:
258 These are selectable by the user and have names beginning with
261 * Configuration _SETTINGS_:
262 These depend on the hardware etc. and should not be meddled with if
263 you don't know what you're doing; they have names beginning with
266 Later we will add a configuration tool - probably similar to or even
267 identical to what's used for the Linux kernel. Right now, we have to
268 do the configuration by hand, which means creating some symbolic
269 links and editing some configuration files. We use the TQM8xxL boards
273 Selection of Processor Architecture and Board Type:
274 ---------------------------------------------------
276 For all supported boards there are ready-to-use default
277 configurations available; just type "make <board_name>_config".
279 Example: For a TQM823L module type:
284 For the Cogent platform, you need to specify the cpu type as well;
285 e.g. "make cogent_mpc8xx_config". And also configure the cogent
286 directory according to the instructions in cogent/README.
289 Configuration Options:
290 ----------------------
292 Configuration depends on the combination of board and CPU type; all
293 such information is kept in a configuration file
294 "include/configs/<board_name>.h".
296 Example: For a TQM823L module, all configuration settings are in
297 "include/configs/TQM823L.h".
300 Many of the options are named exactly as the corresponding Linux
301 kernel configuration options. The intention is to make it easier to
302 build a config tool - later.
305 The following options need to be configured:
307 - CPU Type: Define exactly one of
311 CONFIG_MPC823, CONFIG_MPC850, CONFIG_MPC855, CONFIG_MPC860
313 or CONFIG_MPC824X, CONFIG_MPC8260
329 - Board Type: Define exactly one of
331 PowerPC based boards:
332 ---------------------
334 CONFIG_ADCIOP, CONFIG_ICU862 CONFIG_RPXsuper,
335 CONFIG_ADS860, CONFIG_IP860, CONFIG_SM850,
336 CONFIG_AMX860, CONFIG_IPHASE4539, CONFIG_SPD823TS,
337 CONFIG_AR405, CONFIG_IVML24, CONFIG_SXNI855T,
338 CONFIG_BAB7xx, CONFIG_IVML24_128, CONFIG_Sandpoint8240,
339 CONFIG_CANBT, CONFIG_IVML24_256, CONFIG_Sandpoint8245,
340 CONFIG_CCM, CONFIG_IVMS8, CONFIG_TQM823L,
341 CONFIG_CPCI405, CONFIG_IVMS8_128, CONFIG_TQM850L,
342 CONFIG_CPCI4052, CONFIG_IVMS8_256, CONFIG_TQM855L,
343 CONFIG_CPCIISER4, CONFIG_LANTEC, CONFIG_TQM860L,
344 CONFIG_CPU86, CONFIG_MBX, CONFIG_TQM8260,
345 CONFIG_CRAYL1, CONFIG_MBX860T, CONFIG_TTTech,
346 CONFIG_CU824, CONFIG_MHPC, CONFIG_UTX8245,
347 CONFIG_DASA_SIM, CONFIG_MIP405, CONFIG_W7OLMC,
348 CONFIG_DU405, CONFIG_MOUSSE, CONFIG_W7OLMG,
349 CONFIG_ELPPC, CONFIG_MPC8260ADS, CONFIG_WALNUT405,
350 CONFIG_ERIC, CONFIG_MUSENKI, CONFIG_ZUMA,
351 CONFIG_ESTEEM192E, CONFIG_MVS1, CONFIG_c2mon,
352 CONFIG_ETX094, CONFIG_NX823, CONFIG_cogent_mpc8260,
353 CONFIG_EVB64260, CONFIG_OCRTC, CONFIG_cogent_mpc8xx,
354 CONFIG_FADS823, CONFIG_ORSG, CONFIG_ep8260,
355 CONFIG_FADS850SAR, CONFIG_OXC, CONFIG_gw8260,
356 CONFIG_FADS860T, CONFIG_PCI405, CONFIG_hermes,
357 CONFIG_FLAGADM, CONFIG_PCIPPC2, CONFIG_hymod,
358 CONFIG_FPS850L, CONFIG_PCIPPC6, CONFIG_lwmon,
359 CONFIG_GEN860T, CONFIG_PIP405, CONFIG_pcu_e,
360 CONFIG_GENIETV, CONFIG_PM826, CONFIG_ppmc8260,
361 CONFIG_GTH, CONFIG_RPXClassic, CONFIG_rsdproto,
362 CONFIG_IAD210, CONFIG_RPXlite, CONFIG_sbc8260,
363 CONFIG_EBONY, CONFIG_sacsng, CONFIG_FPS860L,
364 CONFIG_V37, CONFIG_ELPT860, CONFIG_CMI,
365 CONFIG_NETVIA, CONFIG_RBC823, CONFIG_ZPC1900,
366 CONFIG_MPC8540ADS, CONFIG_MPC8560ADS
371 CONFIG_HHP_CRADLE, CONFIG_DNP1110, CONFIG_EP7312,
372 CONFIG_IMPA7, CONFIG_LART, CONFIG_LUBBOCK,
373 CONFIG_INNOVATOROMAP1510, CONFIG_INNOVATOROMAP1610
374 CONFIG_SHANNON, CONFIG_SMDK2400, CONFIG_SMDK2410,
375 CONFIG_TRAB, CONFIG_VCMA9, CONFIG_AT91RM9200DK
378 - CPU Module Type: (if CONFIG_COGENT is defined)
379 Define exactly one of
381 --- FIXME --- not tested yet:
382 CONFIG_CMA286_60, CONFIG_CMA286_21, CONFIG_CMA286_60P,
383 CONFIG_CMA287_23, CONFIG_CMA287_50
385 - Motherboard Type: (if CONFIG_COGENT is defined)
386 Define exactly one of
387 CONFIG_CMA101, CONFIG_CMA102
389 - Motherboard I/O Modules: (if CONFIG_COGENT is defined)
390 Define one or more of
393 - Motherboard Options: (if CONFIG_CMA101 or CONFIG_CMA102 are defined)
394 Define one or more of
395 CONFIG_LCD_HEARTBEAT - update a character position on
396 the lcd display every second with
399 - Board flavour: (if CONFIG_MPC8260ADS is defined)
402 CFG_8260ADS - original MPC8260ADS
403 CFG_8266ADS - MPC8266ADS (untested)
404 CFG_PQ2FADS - PQ2FADS-ZU or PQ2FADS-VR
407 - MPC824X Family Member (if CONFIG_MPC824X is defined)
408 Define exactly one of
409 CONFIG_MPC8240, CONFIG_MPC8245
411 - 8xx CPU Options: (if using an 8xx cpu)
412 Define one or more of
413 CONFIG_8xx_GCLK_FREQ - if get_gclk_freq() cannot work
414 e.g. if there is no 32KHz
415 reference PIT/RTC clock
417 - Linux Kernel Interface:
420 U-Boot stores all clock information in Hz
421 internally. For binary compatibility with older Linux
422 kernels (which expect the clocks passed in the
423 bd_info data to be in MHz) the environment variable
424 "clocks_in_mhz" can be defined so that U-Boot
425 converts clock data to MHZ before passing it to the
427 When CONFIG_CLOCKS_IN_MHZ is defined, a definition of
428 "clocks_in_mhz=1" is automatically included in the
431 CONFIG_MEMSIZE_IN_BYTES [relevant for MIPS only]
433 When transfering memsize parameter to linux, some versions
434 expect it to be in bytes, others in MB.
435 Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes.
438 Depending on board, define exactly one serial port
439 (like CONFIG_8xx_CONS_SMC1, CONFIG_8xx_CONS_SMC2,
440 CONFIG_8xx_CONS_SCC1, ...), or switch off the serial
441 console by defining CONFIG_8xx_CONS_NONE
443 Note: if CONFIG_8xx_CONS_NONE is defined, the serial
444 port routines must be defined elsewhere
445 (i.e. serial_init(), serial_getc(), ...)
448 Enables console device for a color framebuffer. Needs following
449 defines (cf. smiLynxEM, i8042, board/eltec/bab7xx)
450 VIDEO_FB_LITTLE_ENDIAN graphic memory organisation
452 VIDEO_HW_RECTFILL graphic chip supports
455 VIDEO_HW_BITBLT graphic chip supports
456 bit-blit (cf. smiLynxEM)
457 VIDEO_VISIBLE_COLS visible pixel columns
459 VIDEO_VISIBLE_ROWS visible pixel rows
460 VIDEO_PIXEL_SIZE bytes per pixel
461 VIDEO_DATA_FORMAT graphic data format
462 (0-5, cf. cfb_console.c)
463 VIDEO_FB_ADRS framebuffer address
464 VIDEO_KBD_INIT_FCT keyboard int fct
465 (i.e. i8042_kbd_init())
466 VIDEO_TSTC_FCT test char fct
468 VIDEO_GETC_FCT get char fct
470 CONFIG_CONSOLE_CURSOR cursor drawing on/off
471 (requires blink timer
473 CFG_CONSOLE_BLINK_COUNT blink interval (cf. i8042.c)
474 CONFIG_CONSOLE_TIME display time/date info in
476 (requires CFG_CMD_DATE)
477 CONFIG_VIDEO_LOGO display Linux logo in
479 CONFIG_VIDEO_BMP_LOGO use bmp_logo.h instead of
480 linux_logo.h for logo.
481 Requires CONFIG_VIDEO_LOGO
482 CONFIG_CONSOLE_EXTRA_INFO
483 addional board info beside
486 When CONFIG_CFB_CONSOLE is defined, video console is
487 default i/o. Serial console can be forced with
488 environment 'console=serial'.
490 When CONFIG_SILENT_CONSOLE is defined, all console
491 messages (by U-Boot and Linux!) can be silenced with
492 the "silent" environment variable. See
493 doc/README.silent for more information.
496 CONFIG_BAUDRATE - in bps
497 Select one of the baudrates listed in
498 CFG_BAUDRATE_TABLE, see below.
500 - Interrupt driven serial port input:
501 CONFIG_SERIAL_SOFTWARE_FIFO
504 Use an interrupt handler for receiving data on the
505 serial port. It also enables using hardware handshake
506 (RTS/CTS) and UART's built-in FIFO. Set the number of
507 bytes the interrupt driven input buffer should have.
509 Set to 0 to disable this feature (this is the default).
510 This will also disable hardware handshake.
512 - Console UART Number:
516 If defined internal UART1 (and not UART0) is used
517 as default U-Boot console.
519 - Boot Delay: CONFIG_BOOTDELAY - in seconds
520 Delay before automatically booting the default image;
521 set to -1 to disable autoboot.
523 See doc/README.autoboot for these options that
524 work with CONFIG_BOOTDELAY. None are required.
525 CONFIG_BOOT_RETRY_TIME
526 CONFIG_BOOT_RETRY_MIN
527 CONFIG_AUTOBOOT_KEYED
528 CONFIG_AUTOBOOT_PROMPT
529 CONFIG_AUTOBOOT_DELAY_STR
530 CONFIG_AUTOBOOT_STOP_STR
531 CONFIG_AUTOBOOT_DELAY_STR2
532 CONFIG_AUTOBOOT_STOP_STR2
533 CONFIG_ZERO_BOOTDELAY_CHECK
534 CONFIG_RESET_TO_RETRY
538 Only needed when CONFIG_BOOTDELAY is enabled;
539 define a command string that is automatically executed
540 when no character is read on the console interface
541 within "Boot Delay" after reset.
544 This can be used to pass arguments to the bootm
545 command. The value of CONFIG_BOOTARGS goes into the
546 environment value "bootargs".
548 CONFIG_RAMBOOT and CONFIG_NFSBOOT
549 The value of these goes into the environment as
550 "ramboot" and "nfsboot" respectively, and can be used
551 as a convenience, when switching between booting from
557 When this option is #defined, the existence of the
558 environment variable "preboot" will be checked
559 immediately before starting the CONFIG_BOOTDELAY
560 countdown and/or running the auto-boot command resp.
561 entering interactive mode.
563 This feature is especially useful when "preboot" is
564 automatically generated or modified. For an example
565 see the LWMON board specific code: here "preboot" is
566 modified when the user holds down a certain
567 combination of keys on the (special) keyboard when
570 - Serial Download Echo Mode:
572 If defined to 1, all characters received during a
573 serial download (using the "loads" command) are
574 echoed back. This might be needed by some terminal
575 emulations (like "cu"), but may as well just take
576 time on others. This setting #define's the initial
577 value of the "loads_echo" environment variable.
579 - Kgdb Serial Baudrate: (if CFG_CMD_KGDB is defined)
581 Select one of the baudrates listed in
582 CFG_BAUDRATE_TABLE, see below.
586 Most monitor functions can be selected (or
587 de-selected) by adjusting the definition of
588 CONFIG_COMMANDS; to select individual functions,
589 #define CONFIG_COMMANDS by "OR"ing any of the
592 #define enables commands:
593 -------------------------
594 CFG_CMD_ASKENV * ask for env variable
595 CFG_CMD_AUTOSCRIPT Autoscript Support
597 CFG_CMD_BEDBUG Include BedBug Debugger
598 CFG_CMD_BMP * BMP support
600 CFG_CMD_CACHE icache, dcache
601 CFG_CMD_CONSOLE coninfo
602 CFG_CMD_DATE * support for RTC, date/time...
603 CFG_CMD_DHCP DHCP support
604 CFG_CMD_DIAG * Diagnostics
605 CFG_CMD_DOC * Disk-On-Chip Support
606 CFG_CMD_DTT Digital Therm and Thermostat
607 CFG_CMD_ECHO * echo arguments
608 CFG_CMD_EEPROM * EEPROM read/write support
609 CFG_CMD_ELF bootelf, bootvx
611 CFG_CMD_FDC * Floppy Disk Support
612 CFG_CMD_FAT FAT partition support
613 CFG_CMD_FDOS * Dos diskette Support
614 CFG_CMD_FLASH flinfo, erase, protect
615 CFG_CMD_FPGA FPGA device initialization support
616 CFG_CMD_HWFLOW * RTS/CTS hw flow control
617 CFG_CMD_I2C * I2C serial bus support
618 CFG_CMD_IDE * IDE harddisk support
620 CFG_CMD_IMLS List all found images
621 CFG_CMD_IMMAP * IMMR dump support
622 CFG_CMD_IRQ * irqinfo
623 CFG_CMD_JFFS2 * JFFS2 Support
627 CFG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base,
629 CFG_CMD_MISC Misc functions like sleep etc
630 CFG_CMD_MMC MMC memory mapped support
631 CFG_CMD_MII MII utility commands
632 CFG_CMD_NAND * NAND support
633 CFG_CMD_NET bootp, tftpboot, rarpboot
634 CFG_CMD_PCI * pciinfo
635 CFG_CMD_PCMCIA * PCMCIA support
636 CFG_CMD_PING * send ICMP ECHO_REQUEST to network host
637 CFG_CMD_PORTIO Port I/O
638 CFG_CMD_REGINFO * Register dump
639 CFG_CMD_RUN run command in env variable
640 CFG_CMD_SAVES save S record dump
641 CFG_CMD_SCSI * SCSI Support
642 CFG_CMD_SDRAM * print SDRAM configuration information
643 CFG_CMD_SETGETDCR Support for DCR Register access (4xx only)
644 CFG_CMD_SPI * SPI serial bus support
645 CFG_CMD_USB * USB support
646 CFG_CMD_VFD * VFD support (TRAB)
647 CFG_CMD_BSP * Board SPecific functions
648 -----------------------------------------------
651 CFG_CMD_DFL Default configuration; at the moment
652 this is includes all commands, except
653 the ones marked with "*" in the list
656 If you don't define CONFIG_COMMANDS it defaults to
657 CFG_CMD_DFL in include/cmd_confdefs.h. A board can
658 override the default settings in the respective
661 EXAMPLE: If you want all functions except of network
662 support you can write:
664 #define CONFIG_COMMANDS (CFG_CMD_ALL & ~CFG_CMD_NET)
667 Note: Don't enable the "icache" and "dcache" commands
668 (configuration option CFG_CMD_CACHE) unless you know
669 what you (and your U-Boot users) are doing. Data
670 cache cannot be enabled on systems like the 8xx or
671 8260 (where accesses to the IMMR region must be
672 uncached), and it cannot be disabled on all other
673 systems where we (mis-) use the data cache to hold an
674 initial stack and some data.
677 XXX - this list needs to get updated!
681 If this variable is defined, it enables watchdog
682 support. There must be support in the platform specific
683 code for a watchdog. For the 8xx and 8260 CPUs, the
684 SIU Watchdog feature is enabled in the SYPCR
688 CONFIG_VERSION_VARIABLE
689 If this variable is defined, an environment variable
690 named "ver" is created by U-Boot showing the U-Boot
691 version as printed by the "version" command.
692 This variable is readonly.
696 When CFG_CMD_DATE is selected, the type of the RTC
697 has to be selected, too. Define exactly one of the
700 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx
701 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC
702 CONFIG_RTC_MC146818 - use MC146818 RTC
703 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC
704 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC
705 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC
706 CONFIG_RTC_DS164x - use Dallas DS164x RTC
708 Note that if the RTC uses I2C, then the I2C interface
709 must also be configured. See I2C Support, below.
713 When CONFIG_TIMESTAMP is selected, the timestamp
714 (date and time) of an image is printed by image
715 commands like bootm or iminfo. This option is
716 automatically enabled when you select CFG_CMD_DATE .
719 CONFIG_MAC_PARTITION and/or CONFIG_DOS_PARTITION
720 and/or CONFIG_ISO_PARTITION
722 If IDE or SCSI support is enabled (CFG_CMD_IDE or
723 CFG_CMD_SCSI) you must configure support for at least
724 one partition type as well.
727 CONFIG_IDE_RESET_ROUTINE
729 Set this to define that instead of a reset Pin, the
730 routine ide_set_reset(int idereset) will be used.
735 Set this to enable ATAPI support.
738 At the moment only there is only support for the
739 SYM53C8XX SCSI controller; define
740 CONFIG_SCSI_SYM53C8XX to enable it.
742 CFG_SCSI_MAX_LUN [8], CFG_SCSI_MAX_SCSI_ID [7] and
743 CFG_SCSI_MAX_DEVICE [CFG_SCSI_MAX_SCSI_ID *
744 CFG_SCSI_MAX_LUN] can be adjusted to define the
745 maximum numbers of LUNs, SCSI ID's and target
747 CFG_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz)
749 - NETWORK Support (PCI):
751 Support for Intel 8254x gigabit chips.
754 Support for Intel 82557/82559/82559ER chips.
755 Optional CONFIG_EEPRO100_SROM_WRITE enables eeprom
756 write routine for first time initialisation.
759 Support for Digital 2114x chips.
760 Optional CONFIG_TULIP_SELECT_MEDIA for board specific
761 modem chip initialisation (KS8761/QS6611).
764 Support for National dp83815 chips.
767 Support for National dp8382[01] gigabit chips.
769 - NETWORK Support (other):
771 CONFIG_DRIVER_LAN91C96
772 Support for SMSC's LAN91C96 chips.
775 Define this to hold the physical address
776 of the LAN91C96's I/O space
778 CONFIG_LAN91C96_USE_32_BIT
779 Define this to enable 32 bit addressing
782 At the moment only the UHCI host controller is
783 supported (PIP405, MIP405); define
784 CONFIG_USB_UHCI to enable it.
785 define CONFIG_USB_KEYBOARD to enable the USB Keyboard
786 end define CONFIG_USB_STORAGE to enable the USB
789 Supported are USB Keyboards and USB Floppy drives
793 The MMC controller on the Intel PXA is supported. To
794 enable this define CONFIG_MMC. The MMC can be
795 accessed from the boot prompt by mapping the device
796 to physical memory similar to flash. Command line is
797 enabled with CFG_CMD_MMC. The MMC driver also works with
798 the FAT fs. This is enabled with CFG_CMD_FAT.
803 Define this to enable standard (PC-Style) keyboard
807 Standard PC keyboard driver with US (is default) and
808 GERMAN key layout (switch via environment 'keymap=de') support.
809 Export function i8042_kbd_init, i8042_tstc and i8042_getc
810 for cfb_console. Supports cursor blinking.
815 Define this to enable video support (for output to
820 Enable Chips & Technologies 69000 Video chip
822 CONFIG_VIDEO_SMI_LYNXEM
823 Enable Silicon Motion SMI 712/710/810 Video chip
824 Videomode are selected via environment 'videomode' with
825 standard LiLo mode numbers.
826 Following modes are supported (* is default):
828 800x600 1024x768 1280x1024
829 256 (8bit) 303* 305 307
830 65536 (16bit) 314 317 31a
831 16,7 Mill (24bit) 315 318 31b
832 (i.e. setenv videomode 317; saveenv; reset;)
834 CONFIG_VIDEO_SED13806
835 Enable Epson SED13806 driver. This driver supports 8bpp
836 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP
837 or CONFIG_VIDEO_SED13806_16BPP
842 Define this to enable a custom keyboard support.
843 This simply calls drv_keyboard_init() which must be
844 defined in your board-specific files.
845 The only board using this so far is RBC823.
847 - LCD Support: CONFIG_LCD
849 Define this to enable LCD support (for output to LCD
850 display); also select one of the supported displays
851 by defining one of these:
853 CONFIG_NEC_NL6448AC33:
855 NEC NL6448AC33-18. Active, color, single scan.
857 CONFIG_NEC_NL6448BC20
859 NEC NL6448BC20-08. 6.5", 640x480.
860 Active, color, single scan.
862 CONFIG_NEC_NL6448BC33_54
864 NEC NL6448BC33-54. 10.4", 640x480.
865 Active, color, single scan.
869 Sharp 320x240. Active, color, single scan.
870 It isn't 16x9, and I am not sure what it is.
872 CONFIG_SHARP_LQ64D341
874 Sharp LQ64D341 display, 640x480.
875 Active, color, single scan.
879 HLD1045 display, 640x480.
880 Active, color, single scan.
884 Optrex CBL50840-2 NF-FW 99 22 M5
886 Hitachi LMG6912RPFC-00T
890 320x240. Black & white.
892 Normally display is black on white background; define
893 CFG_WHITE_ON_BLACK to get it inverted.
895 - Splash Screen Support: CONFIG_SPLASH_SCREEN
897 If this option is set, the environment is checked for
898 a variable "splashimage". If found, the usual display
899 of logo, copyright and system information on the LCD
900 is supressed and the BMP image at the address
901 specified in "splashimage" is loaded instead. The
902 console is redirected to the "nulldev", too. This
903 allows for a "silent" boot where a splash screen is
904 loaded very quickly after power-on.
906 - Compression support:
909 If this option is set, support for bzip2 compressed
910 images is included. If not, only uncompressed and gzip
911 compressed images are supported.
913 NOTE: the bzip2 algorithm requires a lot of RAM, so
914 the malloc area (as defined by CFG_MALLOC_LEN) should
922 Define a default value for ethernet address to use
923 for the respective ethernet interface, in case this
924 is not determined automatically.
929 Define a default value for the IP address to use for
930 the default ethernet interface, in case this is not
931 determined through e.g. bootp.
936 Defines a default value for theIP address of a TFTP
937 server to contact when using the "tftboot" command.
939 - BOOTP Recovery Mode:
940 CONFIG_BOOTP_RANDOM_DELAY
942 If you have many targets in a network that try to
943 boot using BOOTP, you may want to avoid that all
944 systems send out BOOTP requests at precisely the same
945 moment (which would happen for instance at recovery
946 from a power failure, when all systems will try to
947 boot, thus flooding the BOOTP server. Defining
948 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
949 inserted before sending out BOOTP requests. The
950 following delays are insterted then:
952 1st BOOTP request: delay 0 ... 1 sec
953 2nd BOOTP request: delay 0 ... 2 sec
954 3rd BOOTP request: delay 0 ... 4 sec
956 BOOTP requests: delay 0 ... 8 sec
958 - DHCP Advanced Options:
961 You can fine tune the DHCP functionality by adding
962 these flags to the CONFIG_BOOTP_MASK define:
964 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS
965 serverip from a DHCP server, it is possible that more
966 than one DNS serverip is offered to the client.
967 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS
968 serverip will be stored in the additional environment
969 variable "dnsip2". The first DNS serverip is always
970 stored in the variable "dnsip", when CONFIG_BOOTP_DNS
971 is added to the CONFIG_BOOTP_MASK.
973 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable
974 to do a dynamic update of a DNS server. To do this, they
975 need the hostname of the DHCP requester.
976 If CONFIG_BOOP_SEND_HOSTNAME is added to the
977 CONFIG_BOOTP_MASK, the content of the "hostname"
978 environment variable is passed as option 12 to
981 - Status LED: CONFIG_STATUS_LED
983 Several configurations allow to display the current
984 status using a LED. For instance, the LED will blink
985 fast while running U-Boot code, stop blinking as
986 soon as a reply to a BOOTP request was received, and
987 start blinking slow once the Linux kernel is running
988 (supported by a status LED driver in the Linux
989 kernel). Defining CONFIG_STATUS_LED enables this
992 - CAN Support: CONFIG_CAN_DRIVER
994 Defining CONFIG_CAN_DRIVER enables CAN driver support
995 on those systems that support this (optional)
996 feature, like the TQM8xxL modules.
998 - I2C Support: CONFIG_HARD_I2C | CONFIG_SOFT_I2C
1000 These enable I2C serial bus commands. Defining either of
1001 (but not both of) CONFIG_HARD_I2C or CONFIG_SOFT_I2C will
1002 include the appropriate I2C driver for the selected cpu.
1004 This will allow you to use i2c commands at the u-boot
1005 command line (as long as you set CFG_CMD_I2C in
1006 CONFIG_COMMANDS) and communicate with i2c based realtime
1007 clock chips. See common/cmd_i2c.c for a description of the
1008 command line interface.
1010 CONFIG_HARD_I2C selects the CPM hardware driver for I2C.
1012 CONFIG_SOFT_I2C configures u-boot to use a software (aka
1013 bit-banging) driver instead of CPM or similar hardware
1016 There are several other quantities that must also be
1017 defined when you define CONFIG_HARD_I2C or CONFIG_SOFT_I2C.
1019 In both cases you will need to define CFG_I2C_SPEED
1020 to be the frequency (in Hz) at which you wish your i2c bus
1021 to run and CFG_I2C_SLAVE to be the address of this node (ie
1022 the cpu's i2c node address).
1024 Now, the u-boot i2c code for the mpc8xx (cpu/mpc8xx/i2c.c)
1025 sets the cpu up as a master node and so its address should
1026 therefore be cleared to 0 (See, eg, MPC823e User's Manual
1027 p.16-473). So, set CFG_I2C_SLAVE to 0.
1029 That's all that's required for CONFIG_HARD_I2C.
1031 If you use the software i2c interface (CONFIG_SOFT_I2C)
1032 then the following macros need to be defined (examples are
1033 from include/configs/lwmon.h):
1037 (Optional). Any commands necessary to enable the I2C
1038 controller or configure ports.
1040 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
1044 (Only for MPC8260 CPU). The I/O port to use (the code
1045 assumes both bits are on the same port). Valid values
1046 are 0..3 for ports A..D.
1050 The code necessary to make the I2C data line active
1051 (driven). If the data line is open collector, this
1054 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
1058 The code necessary to make the I2C data line tri-stated
1059 (inactive). If the data line is open collector, this
1062 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
1066 Code that returns TRUE if the I2C data line is high,
1069 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
1073 If <bit> is TRUE, sets the I2C data line high. If it
1074 is FALSE, it clears it (low).
1076 eg: #define I2C_SDA(bit) \
1077 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
1078 else immr->im_cpm.cp_pbdat &= ~PB_SDA
1082 If <bit> is TRUE, sets the I2C clock line high. If it
1083 is FALSE, it clears it (low).
1085 eg: #define I2C_SCL(bit) \
1086 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
1087 else immr->im_cpm.cp_pbdat &= ~PB_SCL
1091 This delay is invoked four times per clock cycle so this
1092 controls the rate of data transfer. The data rate thus
1093 is 1 / (I2C_DELAY * 4). Often defined to be something
1096 #define I2C_DELAY udelay(2)
1100 When a board is reset during an i2c bus transfer
1101 chips might think that the current transfer is still
1102 in progress. On some boards it is possible to access
1103 the i2c SCLK line directly, either by using the
1104 processor pin as a GPIO or by having a second pin
1105 connected to the bus. If this option is defined a
1106 custom i2c_init_board() routine in boards/xxx/board.c
1107 is run early in the boot sequence.
1109 - SPI Support: CONFIG_SPI
1111 Enables SPI driver (so far only tested with
1112 SPI EEPROM, also an instance works with Crystal A/D and
1113 D/As on the SACSng board)
1117 Enables extended (16-bit) SPI EEPROM addressing.
1118 (symmetrical to CONFIG_I2C_X)
1122 Enables a software (bit-bang) SPI driver rather than
1123 using hardware support. This is a general purpose
1124 driver that only requires three general I/O port pins
1125 (two outputs, one input) to function. If this is
1126 defined, the board configuration must define several
1127 SPI configuration items (port pins to use, etc). For
1128 an example, see include/configs/sacsng.h.
1130 - FPGA Support: CONFIG_FPGA_COUNT
1132 Specify the number of FPGA devices to support.
1136 Used to specify the types of FPGA devices. For
1138 #define CONFIG_FPGA CFG_XILINX_VIRTEX2
1140 CFG_FPGA_PROG_FEEDBACK
1142 Enable printing of hash marks during FPGA
1147 Enable checks on FPGA configuration interface busy
1148 status by the configuration function. This option
1149 will require a board or device specific function to
1154 If defined, a function that provides delays in the
1155 FPGA configuration driver.
1157 CFG_FPGA_CHECK_CTRLC
1159 Allow Control-C to interrupt FPGA configuration
1161 CFG_FPGA_CHECK_ERROR
1163 Check for configuration errors during FPGA bitfile
1164 loading. For example, abort during Virtex II
1165 configuration if the INIT_B line goes low (which
1166 indicated a CRC error).
1170 Maximum time to wait for the INIT_B line to deassert
1171 after PROB_B has been deasserted during a Virtex II
1172 FPGA configuration sequence. The default time is 500 mS.
1176 Maximum time to wait for BUSY to deassert during
1177 Virtex II FPGA configuration. The default is 5 mS.
1179 CFG_FPGA_WAIT_CONFIG
1181 Time to wait after FPGA configuration. The default is
1184 - FPGA Support: CONFIG_FPGA_COUNT
1186 Specify the number of FPGA devices to support.
1190 Used to specify the types of FPGA devices. For example,
1191 #define CONFIG_FPGA CFG_XILINX_VIRTEX2
1193 CFG_FPGA_PROG_FEEDBACK
1195 Enable printing of hash marks during FPGA configuration.
1199 Enable checks on FPGA configuration interface busy
1200 status by the configuration function. This option
1201 will require a board or device specific function to
1206 If defined, a function that provides delays in the FPGA
1207 configuration driver.
1209 CFG_FPGA_CHECK_CTRLC
1210 Allow Control-C to interrupt FPGA configuration
1212 CFG_FPGA_CHECK_ERROR
1214 Check for configuration errors during FPGA bitfile
1215 loading. For example, abort during Virtex II
1216 configuration if the INIT_B line goes low (which
1217 indicated a CRC error).
1221 Maximum time to wait for the INIT_B line to deassert
1222 after PROB_B has been deasserted during a Virtex II
1223 FPGA configuration sequence. The default time is 500
1228 Maximum time to wait for BUSY to deassert during
1229 Virtex II FPGA configuration. The default is 5 mS.
1231 CFG_FPGA_WAIT_CONFIG
1233 Time to wait after FPGA configuration. The default is
1236 - Configuration Management:
1239 If defined, this string will be added to the U-Boot
1240 version information (U_BOOT_VERSION)
1242 - Vendor Parameter Protection:
1244 U-Boot considers the values of the environment
1245 variables "serial#" (Board Serial Number) and
1246 "ethaddr" (Ethernet Address) to be parameters that
1247 are set once by the board vendor / manufacturer, and
1248 protects these variables from casual modification by
1249 the user. Once set, these variables are read-only,
1250 and write or delete attempts are rejected. You can
1251 change this behviour:
1253 If CONFIG_ENV_OVERWRITE is #defined in your config
1254 file, the write protection for vendor parameters is
1255 completely disabled. Anybody can change or delete
1258 Alternatively, if you #define _both_ CONFIG_ETHADDR
1259 _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
1260 ethernet address is installed in the environment,
1261 which can be changed exactly ONCE by the user. [The
1262 serial# is unaffected by this, i. e. it remains
1268 Define this variable to enable the reservation of
1269 "protected RAM", i. e. RAM which is not overwritten
1270 by U-Boot. Define CONFIG_PRAM to hold the number of
1271 kB you want to reserve for pRAM. You can overwrite
1272 this default value by defining an environment
1273 variable "pram" to the number of kB you want to
1274 reserve. Note that the board info structure will
1275 still show the full amount of RAM. If pRAM is
1276 reserved, a new environment variable "mem" will
1277 automatically be defined to hold the amount of
1278 remaining RAM in a form that can be passed as boot
1279 argument to Linux, for instance like that:
1281 setenv bootargs ... mem=\$(mem)
1284 This way you can tell Linux not to use this memory,
1285 either, which results in a memory region that will
1286 not be affected by reboots.
1288 *WARNING* If your board configuration uses automatic
1289 detection of the RAM size, you must make sure that
1290 this memory test is non-destructive. So far, the
1291 following board configurations are known to be
1294 ETX094, IVMS8, IVML24, SPD8xx, TQM8xxL,
1295 HERMES, IP860, RPXlite, LWMON, LANTEC,
1296 PCU_E, FLAGADM, TQM8260
1301 Define this variable to stop the system in case of a
1302 fatal error, so that you have to reset it manually.
1303 This is probably NOT a good idea for an embedded
1304 system where you want to system to reboot
1305 automatically as fast as possible, but it may be
1306 useful during development since you can try to debug
1307 the conditions that lead to the situation.
1309 CONFIG_NET_RETRY_COUNT
1311 This variable defines the number of retries for
1312 network operations like ARP, RARP, TFTP, or BOOTP
1313 before giving up the operation. If not defined, a
1314 default value of 5 is used.
1316 - Command Interpreter:
1319 Define this variable to enable the "hush" shell (from
1320 Busybox) as command line interpreter, thus enabling
1321 powerful command line syntax like
1322 if...then...else...fi conditionals or `&&' and '||'
1323 constructs ("shell scripts").
1325 If undefined, you get the old, much simpler behaviour
1326 with a somewhat smaller memory footprint.
1331 This defines the secondary prompt string, which is
1332 printed when the command interpreter needs more input
1333 to complete a command. Usually "> ".
1337 In the current implementation, the local variables
1338 space and global environment variables space are
1339 separated. Local variables are those you define by
1340 simply typing `name=value'. To access a local
1341 variable later on, you have write `$name' or
1342 `${name}'; to execute the contents of a variable
1343 directly type `$name' at the command prompt.
1345 Global environment variables are those you use
1346 setenv/printenv to work with. To run a command stored
1347 in such a variable, you need to use the run command,
1348 and you must not use the '$' sign to access them.
1350 To store commands and special characters in a
1351 variable, please use double quotation marks
1352 surrounding the whole text of the variable, instead
1353 of the backslashes before semicolons and special
1356 - Default Environment:
1357 CONFIG_EXTRA_ENV_SETTINGS
1359 Define this to contain any number of null terminated
1360 strings (variable = value pairs) that will be part of
1361 the default environment compiled into the boot image.
1363 For example, place something like this in your
1364 board's config file:
1366 #define CONFIG_EXTRA_ENV_SETTINGS \
1370 Warning: This method is based on knowledge about the
1371 internal format how the environment is stored by the
1372 U-Boot code. This is NOT an official, exported
1373 interface! Although it is unlikely that this format
1374 will change soon, there is no guarantee either.
1375 You better know what you are doing here.
1377 Note: overly (ab)use of the default environment is
1378 discouraged. Make sure to check other ways to preset
1379 the environment like the autoscript function or the
1382 - DataFlash Support:
1383 CONFIG_HAS_DATAFLASH
1385 Defining this option enables DataFlash features and
1386 allows to read/write in Dataflash via the standard
1389 - Show boot progress:
1390 CONFIG_SHOW_BOOT_PROGRESS
1392 Defining this option allows to add some board-
1393 specific code (calling a user-provided function
1394 "show_boot_progress(int)") that enables you to show
1395 the system's boot progress on some display (for
1396 example, some LED's) on your board. At the moment,
1397 the following checkpoints are implemented:
1400 1 common/cmd_bootm.c before attempting to boot an image
1401 -1 common/cmd_bootm.c Image header has bad magic number
1402 2 common/cmd_bootm.c Image header has correct magic number
1403 -2 common/cmd_bootm.c Image header has bad checksum
1404 3 common/cmd_bootm.c Image header has correct checksum
1405 -3 common/cmd_bootm.c Image data has bad checksum
1406 4 common/cmd_bootm.c Image data has correct checksum
1407 -4 common/cmd_bootm.c Image is for unsupported architecture
1408 5 common/cmd_bootm.c Architecture check OK
1409 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi, standalone)
1410 6 common/cmd_bootm.c Image Type check OK
1411 -6 common/cmd_bootm.c gunzip uncompression error
1412 -7 common/cmd_bootm.c Unimplemented compression type
1413 7 common/cmd_bootm.c Uncompression OK
1414 -8 common/cmd_bootm.c Wrong Image Type (not kernel, multi, standalone)
1415 8 common/cmd_bootm.c Image Type check OK
1416 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX)
1417 9 common/cmd_bootm.c Start initial ramdisk verification
1418 -10 common/cmd_bootm.c Ramdisk header has bad magic number
1419 -11 common/cmd_bootm.c Ramdisk header has bad checksum
1420 10 common/cmd_bootm.c Ramdisk header is OK
1421 -12 common/cmd_bootm.c Ramdisk data has bad checksum
1422 11 common/cmd_bootm.c Ramdisk data has correct checksum
1423 12 common/cmd_bootm.c Ramdisk verification complete, start loading
1424 -13 common/cmd_bootm.c Wrong Image Type (not PPC Linux Ramdisk)
1425 13 common/cmd_bootm.c Start multifile image verification
1426 14 common/cmd_bootm.c No initial ramdisk, no multifile, continue.
1427 15 common/cmd_bootm.c All preparation done, transferring control to OS
1429 -1 common/cmd_doc.c Bad usage of "doc" command
1430 -1 common/cmd_doc.c No boot device
1431 -1 common/cmd_doc.c Unknown Chip ID on boot device
1432 -1 common/cmd_doc.c Read Error on boot device
1433 -1 common/cmd_doc.c Image header has bad magic number
1435 -1 common/cmd_ide.c Bad usage of "ide" command
1436 -1 common/cmd_ide.c No boot device
1437 -1 common/cmd_ide.c Unknown boot device
1438 -1 common/cmd_ide.c Unknown partition table
1439 -1 common/cmd_ide.c Invalid partition type
1440 -1 common/cmd_ide.c Read Error on boot device
1441 -1 common/cmd_ide.c Image header has bad magic number
1443 -1 common/cmd_nand.c Bad usage of "nand" command
1444 -1 common/cmd_nand.c No boot device
1445 -1 common/cmd_nand.c Unknown Chip ID on boot device
1446 -1 common/cmd_nand.c Read Error on boot device
1447 -1 common/cmd_nand.c Image header has bad magic number
1449 -1 common/env_common.c Environment has a bad CRC, using default
1455 [so far only for SMDK2400 and TRAB boards]
1457 - Modem support endable:
1458 CONFIG_MODEM_SUPPORT
1460 - RTS/CTS Flow control enable:
1463 - Modem debug support:
1464 CONFIG_MODEM_SUPPORT_DEBUG
1466 Enables debugging stuff (char screen[1024], dbg())
1467 for modem support. Useful only with BDI2000.
1469 - Interrupt support (PPC):
1471 There are common interrupt_init() and timer_interrupt()
1472 for all PPC archs. interrupt_init() calls interrupt_init_cpu()
1473 for cpu specific initialization. interrupt_init_cpu()
1474 should set decrementer_count to appropriate value. If
1475 cpu resets decrementer automatically after interrupt
1476 (ppc4xx) it should set decrementer_count to zero.
1477 timer_interrupt() calls timer_interrupt_cpu() for cpu
1478 specific handling. If board has watchdog / status_led
1479 / other_activity_monitor it works automatically from
1480 general timer_interrupt().
1484 In the target system modem support is enabled when a
1485 specific key (key combination) is pressed during
1486 power-on. Otherwise U-Boot will boot normally
1487 (autoboot). The key_pressed() fuction is called from
1488 board_init(). Currently key_pressed() is a dummy
1489 function, returning 1 and thus enabling modem
1492 If there are no modem init strings in the
1493 environment, U-Boot proceed to autoboot; the
1494 previous output (banner, info printfs) will be
1497 See also: doc/README.Modem
1500 Configuration Settings:
1501 -----------------------
1503 - CFG_LONGHELP: Defined when you want long help messages included;
1504 undefine this when you're short of memory.
1506 - CFG_PROMPT: This is what U-Boot prints on the console to
1507 prompt for user input.
1509 - CFG_CBSIZE: Buffer size for input from the Console
1511 - CFG_PBSIZE: Buffer size for Console output
1513 - CFG_MAXARGS: max. Number of arguments accepted for monitor commands
1515 - CFG_BARGSIZE: Buffer size for Boot Arguments which are passed to
1516 the application (usually a Linux kernel) when it is
1519 - CFG_BAUDRATE_TABLE:
1520 List of legal baudrate settings for this board.
1522 - CFG_CONSOLE_INFO_QUIET
1523 Suppress display of console information at boot.
1525 - CFG_CONSOLE_IS_IN_ENV
1526 If the board specific function
1527 extern int overwrite_console (void);
1528 returns 1, the stdin, stderr and stdout are switched to the
1529 serial port, else the settings in the environment are used.
1531 - CFG_CONSOLE_OVERWRITE_ROUTINE
1532 Enable the call to overwrite_console().
1534 - CFG_CONSOLE_ENV_OVERWRITE
1535 Enable overwrite of previous console environment settings.
1537 - CFG_MEMTEST_START, CFG_MEMTEST_END:
1538 Begin and End addresses of the area used by the
1542 Enable an alternate, more extensive memory test.
1544 - CFG_MEMTEST_SCRATCH:
1545 Scratch address used by the alternate memory test
1546 You only need to set this if address zero isn't writeable
1548 - CFG_TFTP_LOADADDR:
1549 Default load address for network file downloads
1551 - CFG_LOADS_BAUD_CHANGE:
1552 Enable temporary baudrate change while serial download
1555 Physical start address of SDRAM. _Must_ be 0 here.
1558 Physical start address of Motherboard I/O (if using a
1562 Physical start address of Flash memory.
1565 Physical start address of boot monitor code (set by
1566 make config files to be same as the text base address
1567 (TEXT_BASE) used when linking) - same as
1568 CFG_FLASH_BASE when booting from flash.
1571 Size of memory reserved for monitor code, used to
1572 determine _at_compile_time_ (!) if the environment is
1573 embedded within the U-Boot image, or in a separate
1577 Size of DRAM reserved for malloc() use.
1580 Maximum size of memory mapped by the startup code of
1581 the Linux kernel; all data that must be processed by
1582 the Linux kernel (bd_info, boot arguments, eventually
1583 initrd image) must be put below this limit.
1585 - CFG_MAX_FLASH_BANKS:
1586 Max number of Flash memory banks
1588 - CFG_MAX_FLASH_SECT:
1589 Max number of sectors on a Flash chip
1591 - CFG_FLASH_ERASE_TOUT:
1592 Timeout for Flash erase operations (in ms)
1594 - CFG_FLASH_WRITE_TOUT:
1595 Timeout for Flash write operations (in ms)
1597 - CFG_FLASH_LOCK_TOUT
1598 Timeout for Flash set sector lock bit operation (in ms)
1600 - CFG_FLASH_UNLOCK_TOUT
1601 Timeout for Flash clear lock bits operation (in ms)
1603 - CFG_FLASH_PROTECTION
1604 If defined, hardware flash sectors protection is used
1605 instead of U-Boot software protection.
1607 - CFG_DIRECT_FLASH_TFTP:
1609 Enable TFTP transfers directly to flash memory;
1610 without this option such a download has to be
1611 performed in two steps: (1) download to RAM, and (2)
1612 copy from RAM to flash.
1614 The two-step approach is usually more reliable, since
1615 you can check if the download worked before you erase
1616 the flash, but in some situations (when sytem RAM is
1617 too limited to allow for a tempory copy of the
1618 downloaded image) this option may be very useful.
1621 Define if the flash driver uses extra elements in the
1622 common flash structure for storing flash geometry
1624 - CFG_RX_ETH_BUFFER:
1625 Defines the number of ethernet receive buffers. On some
1626 ethernet controllers it is recommended to set this value
1627 to 8 or even higher (EEPRO100 or 405 EMAC), since all
1628 buffers can be full shortly after enabling the interface
1629 on high ethernet traffic.
1630 Defaults to 4 if not defined.
1632 The following definitions that deal with the placement and management
1633 of environment data (variable area); in general, we support the
1634 following configurations:
1636 - CFG_ENV_IS_IN_FLASH:
1638 Define this if the environment is in flash memory.
1640 a) The environment occupies one whole flash sector, which is
1641 "embedded" in the text segment with the U-Boot code. This
1642 happens usually with "bottom boot sector" or "top boot
1643 sector" type flash chips, which have several smaller
1644 sectors at the start or the end. For instance, such a
1645 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In
1646 such a case you would place the environment in one of the
1647 4 kB sectors - with U-Boot code before and after it. With
1648 "top boot sector" type flash chips, you would put the
1649 environment in one of the last sectors, leaving a gap
1650 between U-Boot and the environment.
1654 Offset of environment data (variable area) to the
1655 beginning of flash memory; for instance, with bottom boot
1656 type flash chips the second sector can be used: the offset
1657 for this sector is given here.
1659 CFG_ENV_OFFSET is used relative to CFG_FLASH_BASE.
1663 This is just another way to specify the start address of
1664 the flash sector containing the environment (instead of
1667 - CFG_ENV_SECT_SIZE:
1669 Size of the sector containing the environment.
1672 b) Sometimes flash chips have few, equal sized, BIG sectors.
1673 In such a case you don't want to spend a whole sector for
1678 If you use this in combination with CFG_ENV_IS_IN_FLASH
1679 and CFG_ENV_SECT_SIZE, you can specify to use only a part
1680 of this flash sector for the environment. This saves
1681 memory for the RAM copy of the environment.
1683 It may also save flash memory if you decide to use this
1684 when your environment is "embedded" within U-Boot code,
1685 since then the remainder of the flash sector could be used
1686 for U-Boot code. It should be pointed out that this is
1687 STRONGLY DISCOURAGED from a robustness point of view:
1688 updating the environment in flash makes it always
1689 necessary to erase the WHOLE sector. If something goes
1690 wrong before the contents has been restored from a copy in
1691 RAM, your target system will be dead.
1693 - CFG_ENV_ADDR_REDUND
1696 These settings describe a second storage area used to hold
1697 a redundand copy of the environment data, so that there is
1698 a valid backup copy in case there is a power failure during
1699 a "saveenv" operation.
1701 BE CAREFUL! Any changes to the flash layout, and some changes to the
1702 source code will make it necessary to adapt <board>/u-boot.lds*
1706 - CFG_ENV_IS_IN_NVRAM:
1708 Define this if you have some non-volatile memory device
1709 (NVRAM, battery buffered SRAM) which you want to use for the
1715 These two #defines are used to determin the memory area you
1716 want to use for environment. It is assumed that this memory
1717 can just be read and written to, without any special
1720 BE CAREFUL! The first access to the environment happens quite early
1721 in U-Boot initalization (when we try to get the setting of for the
1722 console baudrate). You *MUST* have mappend your NVRAM area then, or
1725 Please note that even with NVRAM we still use a copy of the
1726 environment in RAM: we could work on NVRAM directly, but we want to
1727 keep settings there always unmodified except somebody uses "saveenv"
1728 to save the current settings.
1731 - CFG_ENV_IS_IN_EEPROM:
1733 Use this if you have an EEPROM or similar serial access
1734 device and a driver for it.
1739 These two #defines specify the offset and size of the
1740 environment area within the total memory of your EEPROM.
1742 - CFG_I2C_EEPROM_ADDR:
1743 If defined, specified the chip address of the EEPROM device.
1744 The default address is zero.
1746 - CFG_EEPROM_PAGE_WRITE_BITS:
1747 If defined, the number of bits used to address bytes in a
1748 single page in the EEPROM device. A 64 byte page, for example
1749 would require six bits.
1751 - CFG_EEPROM_PAGE_WRITE_DELAY_MS:
1752 If defined, the number of milliseconds to delay between
1753 page writes. The default is zero milliseconds.
1755 - CFG_I2C_EEPROM_ADDR_LEN:
1756 The length in bytes of the EEPROM memory array address. Note
1757 that this is NOT the chip address length!
1760 The size in bytes of the EEPROM device.
1763 - CFG_SPI_INIT_OFFSET
1765 Defines offset to the initial SPI buffer area in DPRAM. The
1766 area is used at an early stage (ROM part) if the environment
1767 is configured to reside in the SPI EEPROM: We need a 520 byte
1768 scratch DPRAM area. It is used between the two initialization
1769 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems
1770 to be a good choice since it makes it far enough from the
1771 start of the data area as well as from the stack pointer.
1773 Please note that the environment is read-only as long as the monitor
1774 has been relocated to RAM and a RAM copy of the environment has been
1775 created; also, when using EEPROM you will have to use getenv_r()
1776 until then to read environment variables.
1778 The environment is protected by a CRC32 checksum. Before the monitor
1779 is relocated into RAM, as a result of a bad CRC you will be working
1780 with the compiled-in default environment - *silently*!!! [This is
1781 necessary, because the first environment variable we need is the
1782 "baudrate" setting for the console - if we have a bad CRC, we don't
1783 have any device yet where we could complain.]
1785 Note: once the monitor has been relocated, then it will complain if
1786 the default environment is used; a new CRC is computed as soon as you
1787 use the "saveenv" command to store a valid environment.
1789 - CFG_FAULT_ECHO_LINK_DOWN:
1790 Echo the inverted Ethernet link state to the fault LED.
1792 Note: If this option is active, then CFG_FAULT_MII_ADDR
1793 also needs to be defined.
1795 - CFG_FAULT_MII_ADDR:
1796 MII address of the PHY to check for the Ethernet link state.
1798 Low Level (hardware related) configuration options:
1799 ---------------------------------------------------
1801 - CFG_CACHELINE_SIZE:
1802 Cache Line Size of the CPU.
1805 Default address of the IMMR after system reset.
1807 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU,
1808 and RPXsuper) to be able to adjust the position of
1809 the IMMR register after a reset.
1811 - Floppy Disk Support:
1812 CFG_FDC_DRIVE_NUMBER
1814 the default drive number (default value 0)
1818 defines the spacing between fdc chipset registers
1823 defines the offset of register from address. It
1824 depends on which part of the data bus is connected to
1825 the fdc chipset. (default value 0)
1827 If CFG_ISA_IO_STRIDE CFG_ISA_IO_OFFSET and
1828 CFG_FDC_DRIVE_NUMBER are undefined, they take their
1831 if CFG_FDC_HW_INIT is defined, then the function
1832 fdc_hw_init() is called at the beginning of the FDC
1833 setup. fdc_hw_init() must be provided by the board
1834 source code. It is used to make hardware dependant
1837 - CFG_IMMR: Physical address of the Internal Memory Mapped
1838 Register; DO NOT CHANGE! (11-4)
1839 [MPC8xx systems only]
1841 - CFG_INIT_RAM_ADDR:
1843 Start address of memory area that can be used for
1844 initial data and stack; please note that this must be
1845 writable memory that is working WITHOUT special
1846 initialization, i. e. you CANNOT use normal RAM which
1847 will become available only after programming the
1848 memory controller and running certain initialization
1851 U-Boot uses the following memory types:
1852 - MPC8xx and MPC8260: IMMR (internal memory of the CPU)
1853 - MPC824X: data cache
1854 - PPC4xx: data cache
1856 - CFG_GBL_DATA_OFFSET:
1858 Offset of the initial data structure in the memory
1859 area defined by CFG_INIT_RAM_ADDR. Usually
1860 CFG_GBL_DATA_OFFSET is chosen such that the initial
1861 data is located at the end of the available space
1862 (sometimes written as (CFG_INIT_RAM_END -
1863 CFG_INIT_DATA_SIZE), and the initial stack is just
1864 below that area (growing from (CFG_INIT_RAM_ADDR +
1865 CFG_GBL_DATA_OFFSET) downward.
1868 On the MPC824X (or other systems that use the data
1869 cache for initial memory) the address chosen for
1870 CFG_INIT_RAM_ADDR is basically arbitrary - it must
1871 point to an otherwise UNUSED address space between
1872 the top of RAM and the start of the PCI space.
1874 - CFG_SIUMCR: SIU Module Configuration (11-6)
1876 - CFG_SYPCR: System Protection Control (11-9)
1878 - CFG_TBSCR: Time Base Status and Control (11-26)
1880 - CFG_PISCR: Periodic Interrupt Status and Control (11-31)
1882 - CFG_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30)
1884 - CFG_SCCR: System Clock and reset Control Register (15-27)
1886 - CFG_OR_TIMING_SDRAM:
1890 periodic timer for refresh
1892 - CFG_DER: Debug Event Register (37-47)
1894 - FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CFG_REMAP_OR_AM,
1895 CFG_PRELIM_OR_AM, CFG_OR_TIMING_FLASH, CFG_OR0_REMAP,
1896 CFG_OR0_PRELIM, CFG_BR0_PRELIM, CFG_OR1_REMAP, CFG_OR1_PRELIM,
1898 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
1900 - SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
1901 CFG_OR_TIMING_SDRAM, CFG_OR2_PRELIM, CFG_BR2_PRELIM,
1902 CFG_OR3_PRELIM, CFG_BR3_PRELIM:
1903 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
1905 - CFG_MAMR_PTA, CFG_MPTPR_2BK_4K, CFG_MPTPR_1BK_4K, CFG_MPTPR_2BK_8K,
1906 CFG_MPTPR_1BK_8K, CFG_MAMR_8COL, CFG_MAMR_9COL:
1907 Machine Mode Register and Memory Periodic Timer
1908 Prescaler definitions (SDRAM timing)
1910 - CFG_I2C_UCODE_PATCH, CFG_I2C_DPMEM_OFFSET [0x1FC0]:
1911 enable I2C microcode relocation patch (MPC8xx);
1912 define relocation offset in DPRAM [DSP2]
1914 - CFG_SPI_UCODE_PATCH, CFG_SPI_DPMEM_OFFSET [0x1FC0]:
1915 enable SPI microcode relocation patch (MPC8xx);
1916 define relocation offset in DPRAM [SCC4]
1919 Use OSCM clock mode on MBX8xx board. Be careful,
1920 wrong setting might damage your board. Read
1921 doc/README.MBX before setting this variable!
1923 - CFG_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only)
1924 Offset of the bootmode word in DPRAM used by post
1925 (Power On Self Tests). This definition overrides
1926 #define'd default value in commproc.h resp.
1929 - CFG_PCI_SLV_MEM_LOCAL, CFG_PCI_SLV_MEM_BUS, CFG_PICMR0_MASK_ATTRIB,
1930 CFG_PCI_MSTR0_LOCAL, CFG_PCIMSK0_MASK, CFG_PCI_MSTR1_LOCAL,
1931 CFG_PCIMSK1_MASK, CFG_PCI_MSTR_MEM_LOCAL, CFG_PCI_MSTR_MEM_BUS,
1932 CFG_CPU_PCI_MEM_START, CFG_PCI_MSTR_MEM_SIZE, CFG_POCMR0_MASK_ATTRIB,
1933 CFG_PCI_MSTR_MEMIO_LOCAL, CFG_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START,
1934 CFG_PCI_MSTR_MEMIO_SIZE, CFG_POCMR1_MASK_ATTRIB, CFG_PCI_MSTR_IO_LOCAL,
1935 CFG_PCI_MSTR_IO_BUS, CFG_CPU_PCI_IO_START, CFG_PCI_MSTR_IO_SIZE,
1936 CFG_POCMR2_MASK_ATTRIB: (MPC826x only)
1937 Overrides the default PCI memory map in cpu/mpc8260/pci.c if set.
1939 Building the Software:
1940 ======================
1942 Building U-Boot has been tested in native PPC environments (on a
1943 PowerBook G3 running LinuxPPC 2000) and in cross environments
1944 (running RedHat 6.x and 7.x Linux on x86, Solaris 2.6 on a SPARC, and
1947 If you are not using a native PPC environment, it is assumed that you
1948 have the GNU cross compiling tools available in your path and named
1949 with a prefix of "powerpc-linux-". If this is not the case, (e.g. if
1950 you are using Monta Vista's Hard Hat Linux CDK 1.2) you must change
1951 the definition of CROSS_COMPILE in Makefile. For HHL on a 4xx CPU,
1954 CROSS_COMPILE = ppc_4xx-
1957 U-Boot is intended to be simple to build. After installing the
1958 sources you must configure U-Boot for one specific board type. This
1963 where "NAME_config" is the name of one of the existing
1964 configurations; the following names are supported:
1966 ADCIOP_config GTH_config TQM850L_config
1967 ADS860_config IP860_config TQM855L_config
1968 AR405_config IVML24_config TQM860L_config
1969 CANBT_config IVMS8_config WALNUT405_config
1970 CPCI405_config LANTEC_config cogent_common_config
1971 CPCIISER4_config MBX_config cogent_mpc8260_config
1972 CU824_config MBX860T_config cogent_mpc8xx_config
1973 ESTEEM192E_config RPXlite_config hermes_config
1974 ETX094_config RPXsuper_config hymod_config
1975 FADS823_config SM850_config lwmon_config
1976 FADS850SAR_config SPD823TS_config pcu_e_config
1977 FADS860T_config SXNI855T_config rsdproto_config
1978 FPS850L_config Sandpoint8240_config sbc8260_config
1979 GENIETV_config TQM823L_config PIP405_config
1980 GEN860T_config EBONY_config FPS860L_config
1981 ELPT860_config cmi_mpc5xx_config NETVIA_config
1982 at91rm9200dk_config omap1510inn_config MPC8260ADS_config
1983 omap1610inn_config ZPC1900_config MPC8540ADS_config
1986 Note: for some board special configuration names may exist; check if
1987 additional information is available from the board vendor; for
1988 instance, the TQM8xxL systems run normally at 50 MHz and use a
1989 SCC for 10baseT ethernet; there are also systems with 80 MHz
1990 CPU clock, and an optional Fast Ethernet module is available
1991 for CPU's with FEC. You can select such additional "features"
1992 when chosing the configuration, i. e.
1995 - will configure for a plain TQM860L, i. e. 50MHz, no FEC
1997 make TQM860L_FEC_config
1998 - will configure for a TQM860L at 50MHz with FEC for ethernet
2000 make TQM860L_80MHz_config
2001 - will configure for a TQM860L at 80 MHz, with normal 10baseT
2004 make TQM860L_FEC_80MHz_config
2005 - will configure for a TQM860L at 80 MHz with FEC for ethernet
2007 make TQM823L_LCD_config
2008 - will configure for a TQM823L with U-Boot console on LCD
2010 make TQM823L_LCD_80MHz_config
2011 - will configure for a TQM823L at 80 MHz with U-Boot console on LCD
2016 Finally, type "make all", and you should get some working U-Boot
2017 images ready for download to / installation on your system:
2019 - "u-boot.bin" is a raw binary image
2020 - "u-boot" is an image in ELF binary format
2021 - "u-boot.srec" is in Motorola S-Record format
2024 Please be aware that the Makefiles assume you are using GNU make, so
2025 for instance on NetBSD you might need to use "gmake" instead of
2029 If the system board that you have is not listed, then you will need
2030 to port U-Boot to your hardware platform. To do this, follow these
2033 1. Add a new configuration option for your board to the toplevel
2034 "Makefile" and to the "MAKEALL" script, using the existing
2035 entries as examples. Note that here and at many other places
2036 boards and other names are listed in alphabetical sort order. Please
2038 2. Create a new directory to hold your board specific code. Add any
2039 files you need. In your board directory, you will need at least
2040 the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds".
2041 3. Create a new configuration file "include/configs/<board>.h" for
2043 3. If you're porting U-Boot to a new CPU, then also create a new
2044 directory to hold your CPU specific code. Add any files you need.
2045 4. Run "make <board>_config" with your new name.
2046 5. Type "make", and you should get a working "u-boot.srec" file
2047 to be installed on your target system.
2048 6. Debug and solve any problems that might arise.
2049 [Of course, this last step is much harder than it sounds.]
2052 Testing of U-Boot Modifications, Ports to New Hardware, etc.:
2053 ==============================================================
2055 If you have modified U-Boot sources (for instance added a new board
2056 or support for new devices, a new CPU, etc.) you are expected to
2057 provide feedback to the other developers. The feedback normally takes
2058 the form of a "patch", i. e. a context diff against a certain (latest
2059 official or latest in CVS) version of U-Boot sources.
2061 But before you submit such a patch, please verify that your modifi-
2062 cation did not break existing code. At least make sure that *ALL* of
2063 the supported boards compile WITHOUT ANY compiler warnings. To do so,
2064 just run the "MAKEALL" script, which will configure and build U-Boot
2065 for ALL supported system. Be warned, this will take a while. You can
2066 select which (cross) compiler to use by passing a `CROSS_COMPILE'
2067 environment variable to the script, i. e. to use the cross tools from
2068 MontaVista's Hard Hat Linux you can type
2070 CROSS_COMPILE=ppc_8xx- MAKEALL
2072 or to build on a native PowerPC system you can type
2074 CROSS_COMPILE=' ' MAKEALL
2076 See also "U-Boot Porting Guide" below.
2079 Monitor Commands - Overview:
2080 ============================
2082 go - start application at address 'addr'
2083 run - run commands in an environment variable
2084 bootm - boot application image from memory
2085 bootp - boot image via network using BootP/TFTP protocol
2086 tftpboot- boot image via network using TFTP protocol
2087 and env variables "ipaddr" and "serverip"
2088 (and eventually "gatewayip")
2089 rarpboot- boot image via network using RARP/TFTP protocol
2090 diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
2091 loads - load S-Record file over serial line
2092 loadb - load binary file over serial line (kermit mode)
2094 mm - memory modify (auto-incrementing)
2095 nm - memory modify (constant address)
2096 mw - memory write (fill)
2098 cmp - memory compare
2099 crc32 - checksum calculation
2100 imd - i2c memory display
2101 imm - i2c memory modify (auto-incrementing)
2102 inm - i2c memory modify (constant address)
2103 imw - i2c memory write (fill)
2104 icrc32 - i2c checksum calculation
2105 iprobe - probe to discover valid I2C chip addresses
2106 iloop - infinite loop on address range
2107 isdram - print SDRAM configuration information
2108 sspi - SPI utility commands
2109 base - print or set address offset
2110 printenv- print environment variables
2111 setenv - set environment variables
2112 saveenv - save environment variables to persistent storage
2113 protect - enable or disable FLASH write protection
2114 erase - erase FLASH memory
2115 flinfo - print FLASH memory information
2116 bdinfo - print Board Info structure
2117 iminfo - print header information for application image
2118 coninfo - print console devices and informations
2119 ide - IDE sub-system
2120 loop - infinite loop on address range
2121 mtest - simple RAM test
2122 icache - enable or disable instruction cache
2123 dcache - enable or disable data cache
2124 reset - Perform RESET of the CPU
2125 echo - echo args to console
2126 version - print monitor version
2127 help - print online help
2128 ? - alias for 'help'
2131 Monitor Commands - Detailed Description:
2132 ========================================
2136 For now: just type "help <command>".
2139 Environment Variables:
2140 ======================
2142 U-Boot supports user configuration using Environment Variables which
2143 can be made persistent by saving to Flash memory.
2145 Environment Variables are set using "setenv", printed using
2146 "printenv", and saved to Flash using "saveenv". Using "setenv"
2147 without a value can be used to delete a variable from the
2148 environment. As long as you don't save the environment you are
2149 working with an in-memory copy. In case the Flash area containing the
2150 environment is erased by accident, a default environment is provided.
2152 Some configuration options can be set using Environment Variables:
2154 baudrate - see CONFIG_BAUDRATE
2156 bootdelay - see CONFIG_BOOTDELAY
2158 bootcmd - see CONFIG_BOOTCOMMAND
2160 bootargs - Boot arguments when booting an RTOS image
2162 bootfile - Name of the image to load with TFTP
2164 autoload - if set to "no" (any string beginning with 'n'),
2165 "bootp" will just load perform a lookup of the
2166 configuration from the BOOTP server, but not try to
2167 load any image using TFTP
2169 autostart - if set to "yes", an image loaded using the "bootp",
2170 "rarpboot", "tftpboot" or "diskboot" commands will
2171 be automatically started (by internally calling
2174 If set to "no", a standalone image passed to the
2175 "bootm" command will be copied to the load address
2176 (and eventually uncompressed), but NOT be started.
2177 This can be used to load and uncompress arbitrary
2180 initrd_high - restrict positioning of initrd images:
2181 If this variable is not set, initrd images will be
2182 copied to the highest possible address in RAM; this
2183 is usually what you want since it allows for
2184 maximum initrd size. If for some reason you want to
2185 make sure that the initrd image is loaded below the
2186 CFG_BOOTMAPSZ limit, you can set this environment
2187 variable to a value of "no" or "off" or "0".
2188 Alternatively, you can set it to a maximum upper
2189 address to use (U-Boot will still check that it
2190 does not overwrite the U-Boot stack and data).
2192 For instance, when you have a system with 16 MB
2193 RAM, and want to reserve 4 MB from use by Linux,
2194 you can do this by adding "mem=12M" to the value of
2195 the "bootargs" variable. However, now you must make
2196 sure that the initrd image is placed in the first
2197 12 MB as well - this can be done with
2199 setenv initrd_high 00c00000
2201 If you set initrd_high to 0xFFFFFFFF, this is an
2202 indication to U-Boot that all addresses are legal
2203 for the Linux kernel, including addresses in flash
2204 memory. In this case U-Boot will NOT COPY the
2205 ramdisk at all. This may be useful to reduce the
2206 boot time on your system, but requires that this
2207 feature is supported by your Linux kernel.
2209 ipaddr - IP address; needed for tftpboot command
2211 loadaddr - Default load address for commands like "bootp",
2212 "rarpboot", "tftpboot", "loadb" or "diskboot"
2214 loads_echo - see CONFIG_LOADS_ECHO
2216 serverip - TFTP server IP address; needed for tftpboot command
2218 bootretry - see CONFIG_BOOT_RETRY_TIME
2220 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
2222 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
2225 The following environment variables may be used and automatically
2226 updated by the network boot commands ("bootp" and "rarpboot"),
2227 depending the information provided by your boot server:
2229 bootfile - see above
2230 dnsip - IP address of your Domain Name Server
2231 dnsip2 - IP address of your secondary Domain Name Server
2232 gatewayip - IP address of the Gateway (Router) to use
2233 hostname - Target hostname
2235 netmask - Subnet Mask
2236 rootpath - Pathname of the root filesystem on the NFS server
2237 serverip - see above
2240 There are two special Environment Variables:
2242 serial# - contains hardware identification information such
2243 as type string and/or serial number
2244 ethaddr - Ethernet address
2246 These variables can be set only once (usually during manufacturing of
2247 the board). U-Boot refuses to delete or overwrite these variables
2248 once they have been set once.
2251 Further special Environment Variables:
2253 ver - Contains the U-Boot version string as printed
2254 with the "version" command. This variable is
2255 readonly (see CONFIG_VERSION_VARIABLE).
2258 Please note that changes to some configuration parameters may take
2259 only effect after the next boot (yes, that's just like Windoze :-).
2262 Command Line Parsing:
2263 =====================
2265 There are two different command line parsers available with U-Boot:
2266 the old "simple" one, and the much more powerful "hush" shell:
2268 Old, simple command line parser:
2269 --------------------------------
2271 - supports environment variables (through setenv / saveenv commands)
2272 - several commands on one line, separated by ';'
2273 - variable substitution using "... $(name) ..." syntax
2274 - special characters ('$', ';') can be escaped by prefixing with '\',
2276 setenv bootcmd bootm \$(address)
2277 - You can also escape text by enclosing in single apostrophes, for example:
2278 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
2283 - similar to Bourne shell, with control structures like
2284 if...then...else...fi, for...do...done; while...do...done,
2285 until...do...done, ...
2286 - supports environment ("global") variables (through setenv / saveenv
2287 commands) and local shell variables (through standard shell syntax
2288 "name=value"); only environment variables can be used with "run"
2294 (1) If a command line (or an environment variable executed by a "run"
2295 command) contains several commands separated by semicolon, and
2296 one of these commands fails, then the remaining commands will be
2299 (2) If you execute several variables with one call to run (i. e.
2300 calling run with a list af variables as arguments), any failing
2301 command will cause "run" to terminate, i. e. the remaining
2302 variables are not executed.
2304 Note for Redundant Ethernet Interfaces:
2305 =======================================
2307 Some boards come with redundant ethernet interfaces; U-Boot supports
2308 such configurations and is capable of automatic selection of a
2309 "working" interface when needed. MAC assignment works as follows:
2311 Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
2312 MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
2313 "eth1addr" (=>eth1), "eth2addr", ...
2315 If the network interface stores some valid MAC address (for instance
2316 in SROM), this is used as default address if there is NO correspon-
2317 ding setting in the environment; if the corresponding environment
2318 variable is set, this overrides the settings in the card; that means:
2320 o If the SROM has a valid MAC address, and there is no address in the
2321 environment, the SROM's address is used.
2323 o If there is no valid address in the SROM, and a definition in the
2324 environment exists, then the value from the environment variable is
2327 o If both the SROM and the environment contain a MAC address, and
2328 both addresses are the same, this MAC address is used.
2330 o If both the SROM and the environment contain a MAC address, and the
2331 addresses differ, the value from the environment is used and a
2334 o If neither SROM nor the environment contain a MAC address, an error
2341 The "boot" commands of this monitor operate on "image" files which
2342 can be basicly anything, preceeded by a special header; see the
2343 definitions in include/image.h for details; basicly, the header
2344 defines the following image properties:
2346 * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
2347 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
2348 LynxOS, pSOS, QNX, RTEMS, ARTOS;
2349 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, ARTOS, LynxOS).
2350 * Target CPU Architecture (Provisions for Alpha, ARM, Intel x86,
2351 IA64, MIPS, NIOS, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
2352 Currently supported: ARM, Intel x86, MIPS, NIOS, PowerPC).
2353 * Compression Type (uncompressed, gzip, bzip2)
2359 The header is marked by a special Magic Number, and both the header
2360 and the data portions of the image are secured against corruption by
2367 Although U-Boot should support any OS or standalone application
2368 easily, the main focus has always been on Linux during the design of
2371 U-Boot includes many features that so far have been part of some
2372 special "boot loader" code within the Linux kernel. Also, any
2373 "initrd" images to be used are no longer part of one big Linux image;
2374 instead, kernel and "initrd" are separate images. This implementation
2375 serves several purposes:
2377 - the same features can be used for other OS or standalone
2378 applications (for instance: using compressed images to reduce the
2379 Flash memory footprint)
2381 - it becomes much easier to port new Linux kernel versions because
2382 lots of low-level, hardware dependent stuff are done by U-Boot
2384 - the same Linux kernel image can now be used with different "initrd"
2385 images; of course this also means that different kernel images can
2386 be run with the same "initrd". This makes testing easier (you don't
2387 have to build a new "zImage.initrd" Linux image when you just
2388 change a file in your "initrd"). Also, a field-upgrade of the
2389 software is easier now.
2395 Porting Linux to U-Boot based systems:
2396 ---------------------------------------
2398 U-Boot cannot save you from doing all the necessary modifications to
2399 configure the Linux device drivers for use with your target hardware
2400 (no, we don't intend to provide a full virtual machine interface to
2403 But now you can ignore ALL boot loader code (in arch/ppc/mbxboot).
2405 Just make sure your machine specific header file (for instance
2406 include/asm-ppc/tqm8xx.h) includes the same definition of the Board
2407 Information structure as we define in include/u-boot.h, and make
2408 sure that your definition of IMAP_ADDR uses the same value as your
2409 U-Boot configuration in CFG_IMMR.
2412 Configuring the Linux kernel:
2413 -----------------------------
2415 No specific requirements for U-Boot. Make sure you have some root
2416 device (initial ramdisk, NFS) for your target system.
2419 Building a Linux Image:
2420 -----------------------
2422 With U-Boot, "normal" build targets like "zImage" or "bzImage" are
2423 not used. If you use recent kernel source, a new build target
2424 "uImage" will exist which automatically builds an image usable by
2425 U-Boot. Most older kernels also have support for a "pImage" target,
2426 which was introduced for our predecessor project PPCBoot and uses a
2427 100% compatible format.
2436 The "uImage" build target uses a special tool (in 'tools/mkimage') to
2437 encapsulate a compressed Linux kernel image with header information,
2438 CRC32 checksum etc. for use with U-Boot. This is what we are doing:
2440 * build a standard "vmlinux" kernel image (in ELF binary format):
2442 * convert the kernel into a raw binary image:
2444 ${CROSS_COMPILE}-objcopy -O binary \
2445 -R .note -R .comment \
2446 -S vmlinux linux.bin
2448 * compress the binary image:
2452 * package compressed binary image for U-Boot:
2454 mkimage -A ppc -O linux -T kernel -C gzip \
2455 -a 0 -e 0 -n "Linux Kernel Image" \
2456 -d linux.bin.gz uImage
2459 The "mkimage" tool can also be used to create ramdisk images for use
2460 with U-Boot, either separated from the Linux kernel image, or
2461 combined into one file. "mkimage" encapsulates the images with a 64
2462 byte header containing information about target architecture,
2463 operating system, image type, compression method, entry points, time
2464 stamp, CRC32 checksums, etc.
2466 "mkimage" can be called in two ways: to verify existing images and
2467 print the header information, or to build new images.
2469 In the first form (with "-l" option) mkimage lists the information
2470 contained in the header of an existing U-Boot image; this includes
2471 checksum verification:
2473 tools/mkimage -l image
2474 -l ==> list image header information
2476 The second form (with "-d" option) is used to build a U-Boot image
2477 from a "data file" which is used as image payload:
2479 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
2480 -n name -d data_file image
2481 -A ==> set architecture to 'arch'
2482 -O ==> set operating system to 'os'
2483 -T ==> set image type to 'type'
2484 -C ==> set compression type 'comp'
2485 -a ==> set load address to 'addr' (hex)
2486 -e ==> set entry point to 'ep' (hex)
2487 -n ==> set image name to 'name'
2488 -d ==> use image data from 'datafile'
2490 Right now, all Linux kernels use the same load address (0x00000000),
2491 but the entry point address depends on the kernel version:
2493 - 2.2.x kernels have the entry point at 0x0000000C,
2494 - 2.3.x and later kernels have the entry point at 0x00000000.
2496 So a typical call to build a U-Boot image would read:
2498 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
2499 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
2500 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux.gz \
2501 > examples/uImage.TQM850L
2502 Image Name: 2.4.4 kernel for TQM850L
2503 Created: Wed Jul 19 02:34:59 2000
2504 Image Type: PowerPC Linux Kernel Image (gzip compressed)
2505 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
2506 Load Address: 0x00000000
2507 Entry Point: 0x00000000
2509 To verify the contents of the image (or check for corruption):
2511 -> tools/mkimage -l examples/uImage.TQM850L
2512 Image Name: 2.4.4 kernel for TQM850L
2513 Created: Wed Jul 19 02:34:59 2000
2514 Image Type: PowerPC Linux Kernel Image (gzip compressed)
2515 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
2516 Load Address: 0x00000000
2517 Entry Point: 0x00000000
2519 NOTE: for embedded systems where boot time is critical you can trade
2520 speed for memory and install an UNCOMPRESSED image instead: this
2521 needs more space in Flash, but boots much faster since it does not
2522 need to be uncompressed:
2524 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux.gz
2525 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
2526 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
2527 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux \
2528 > examples/uImage.TQM850L-uncompressed
2529 Image Name: 2.4.4 kernel for TQM850L
2530 Created: Wed Jul 19 02:34:59 2000
2531 Image Type: PowerPC Linux Kernel Image (uncompressed)
2532 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
2533 Load Address: 0x00000000
2534 Entry Point: 0x00000000
2537 Similar you can build U-Boot images from a 'ramdisk.image.gz' file
2538 when your kernel is intended to use an initial ramdisk:
2540 -> tools/mkimage -n 'Simple Ramdisk Image' \
2541 > -A ppc -O linux -T ramdisk -C gzip \
2542 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
2543 Image Name: Simple Ramdisk Image
2544 Created: Wed Jan 12 14:01:50 2000
2545 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
2546 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
2547 Load Address: 0x00000000
2548 Entry Point: 0x00000000
2551 Installing a Linux Image:
2552 -------------------------
2554 To downloading a U-Boot image over the serial (console) interface,
2555 you must convert the image to S-Record format:
2557 objcopy -I binary -O srec examples/image examples/image.srec
2559 The 'objcopy' does not understand the information in the U-Boot
2560 image header, so the resulting S-Record file will be relative to
2561 address 0x00000000. To load it to a given address, you need to
2562 specify the target address as 'offset' parameter with the 'loads'
2565 Example: install the image to address 0x40100000 (which on the
2566 TQM8xxL is in the first Flash bank):
2568 => erase 40100000 401FFFFF
2574 ## Ready for S-Record download ...
2575 ~>examples/image.srec
2576 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
2578 15989 15990 15991 15992
2579 [file transfer complete]
2581 ## Start Addr = 0x00000000
2584 You can check the success of the download using the 'iminfo' command;
2585 this includes a checksum verification so you can be sure no data
2586 corruption happened:
2590 ## Checking Image at 40100000 ...
2591 Image Name: 2.2.13 for initrd on TQM850L
2592 Image Type: PowerPC Linux Kernel Image (gzip compressed)
2593 Data Size: 335725 Bytes = 327 kB = 0 MB
2594 Load Address: 00000000
2595 Entry Point: 0000000c
2596 Verifying Checksum ... OK
2602 The "bootm" command is used to boot an application that is stored in
2603 memory (RAM or Flash). In case of a Linux kernel image, the contents
2604 of the "bootargs" environment variable is passed to the kernel as
2605 parameters. You can check and modify this variable using the
2606 "printenv" and "setenv" commands:
2609 => printenv bootargs
2610 bootargs=root=/dev/ram
2612 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
2614 => printenv bootargs
2615 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
2618 ## Booting Linux kernel at 40020000 ...
2619 Image Name: 2.2.13 for NFS on TQM850L
2620 Image Type: PowerPC Linux Kernel Image (gzip compressed)
2621 Data Size: 381681 Bytes = 372 kB = 0 MB
2622 Load Address: 00000000
2623 Entry Point: 0000000c
2624 Verifying Checksum ... OK
2625 Uncompressing Kernel Image ... OK
2626 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
2627 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
2628 time_init: decrementer frequency = 187500000/60
2629 Calibrating delay loop... 49.77 BogoMIPS
2630 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
2633 If you want to boot a Linux kernel with initial ram disk, you pass
2634 the memory addresses of both the kernel and the initrd image (PPBCOOT
2635 format!) to the "bootm" command:
2637 => imi 40100000 40200000
2639 ## Checking Image at 40100000 ...
2640 Image Name: 2.2.13 for initrd on TQM850L
2641 Image Type: PowerPC Linux Kernel Image (gzip compressed)
2642 Data Size: 335725 Bytes = 327 kB = 0 MB
2643 Load Address: 00000000
2644 Entry Point: 0000000c
2645 Verifying Checksum ... OK
2647 ## Checking Image at 40200000 ...
2648 Image Name: Simple Ramdisk Image
2649 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
2650 Data Size: 566530 Bytes = 553 kB = 0 MB
2651 Load Address: 00000000
2652 Entry Point: 00000000
2653 Verifying Checksum ... OK
2655 => bootm 40100000 40200000
2656 ## Booting Linux kernel at 40100000 ...
2657 Image Name: 2.2.13 for initrd on TQM850L
2658 Image Type: PowerPC Linux Kernel Image (gzip compressed)
2659 Data Size: 335725 Bytes = 327 kB = 0 MB
2660 Load Address: 00000000
2661 Entry Point: 0000000c
2662 Verifying Checksum ... OK
2663 Uncompressing Kernel Image ... OK
2664 ## Loading RAMDisk Image at 40200000 ...
2665 Image Name: Simple Ramdisk Image
2666 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
2667 Data Size: 566530 Bytes = 553 kB = 0 MB
2668 Load Address: 00000000
2669 Entry Point: 00000000
2670 Verifying Checksum ... OK
2671 Loading Ramdisk ... OK
2672 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
2673 Boot arguments: root=/dev/ram
2674 time_init: decrementer frequency = 187500000/60
2675 Calibrating delay loop... 49.77 BogoMIPS
2677 RAMDISK: Compressed image found at block 0
2678 VFS: Mounted root (ext2 filesystem).
2682 More About U-Boot Image Types:
2683 ------------------------------
2685 U-Boot supports the following image types:
2687 "Standalone Programs" are directly runnable in the environment
2688 provided by U-Boot; it is expected that (if they behave
2689 well) you can continue to work in U-Boot after return from
2690 the Standalone Program.
2691 "OS Kernel Images" are usually images of some Embedded OS which
2692 will take over control completely. Usually these programs
2693 will install their own set of exception handlers, device
2694 drivers, set up the MMU, etc. - this means, that you cannot
2695 expect to re-enter U-Boot except by resetting the CPU.
2696 "RAMDisk Images" are more or less just data blocks, and their
2697 parameters (address, size) are passed to an OS kernel that is
2699 "Multi-File Images" contain several images, typically an OS
2700 (Linux) kernel image and one or more data images like
2701 RAMDisks. This construct is useful for instance when you want
2702 to boot over the network using BOOTP etc., where the boot
2703 server provides just a single image file, but you want to get
2704 for instance an OS kernel and a RAMDisk image.
2706 "Multi-File Images" start with a list of image sizes, each
2707 image size (in bytes) specified by an "uint32_t" in network
2708 byte order. This list is terminated by an "(uint32_t)0".
2709 Immediately after the terminating 0 follow the images, one by
2710 one, all aligned on "uint32_t" boundaries (size rounded up to
2711 a multiple of 4 bytes).
2713 "Firmware Images" are binary images containing firmware (like
2714 U-Boot or FPGA images) which usually will be programmed to
2717 "Script files" are command sequences that will be executed by
2718 U-Boot's command interpreter; this feature is especially
2719 useful when you configure U-Boot to use a real shell (hush)
2720 as command interpreter.
2726 One of the features of U-Boot is that you can dynamically load and
2727 run "standalone" applications, which can use some resources of
2728 U-Boot like console I/O functions or interrupt services.
2730 Two simple examples are included with the sources:
2735 'examples/hello_world.c' contains a small "Hello World" Demo
2736 application; it is automatically compiled when you build U-Boot.
2737 It's configured to run at address 0x00040004, so you can play with it
2741 ## Ready for S-Record download ...
2742 ~>examples/hello_world.srec
2743 1 2 3 4 5 6 7 8 9 10 11 ...
2744 [file transfer complete]
2746 ## Start Addr = 0x00040004
2748 => go 40004 Hello World! This is a test.
2749 ## Starting application at 0x00040004 ...
2760 Hit any key to exit ...
2762 ## Application terminated, rc = 0x0
2764 Another example, which demonstrates how to register a CPM interrupt
2765 handler with the U-Boot code, can be found in 'examples/timer.c'.
2766 Here, a CPM timer is set up to generate an interrupt every second.
2767 The interrupt service routine is trivial, just printing a '.'
2768 character, but this is just a demo program. The application can be
2769 controlled by the following keys:
2771 ? - print current values og the CPM Timer registers
2772 b - enable interrupts and start timer
2773 e - stop timer and disable interrupts
2774 q - quit application
2777 ## Ready for S-Record download ...
2778 ~>examples/timer.srec
2779 1 2 3 4 5 6 7 8 9 10 11 ...
2780 [file transfer complete]
2782 ## Start Addr = 0x00040004
2785 ## Starting application at 0x00040004 ...
2788 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
2791 [q, b, e, ?] Set interval 1000000 us
2794 [q, b, e, ?] ........
2795 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
2798 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
2801 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
2804 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
2806 [q, b, e, ?] ...Stopping timer
2808 [q, b, e, ?] ## Application terminated, rc = 0x0
2814 Over time, many people have reported problems when trying to use the
2815 "minicom" terminal emulation program for serial download. I (wd)
2816 consider minicom to be broken, and recommend not to use it. Under
2817 Unix, I recommend to use C-Kermit for general purpose use (and
2818 especially for kermit binary protocol download ("loadb" command), and
2819 use "cu" for S-Record download ("loads" command).
2821 Nevertheless, if you absolutely want to use it try adding this
2822 configuration to your "File transfer protocols" section:
2824 Name Program Name U/D FullScr IO-Red. Multi
2825 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
2826 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
2832 Starting at version 0.9.2, U-Boot supports NetBSD both as host
2833 (build U-Boot) and target system (boots NetBSD/mpc8xx).
2835 Building requires a cross environment; it is known to work on
2836 NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
2837 need gmake since the Makefiles are not compatible with BSD make).
2838 Note that the cross-powerpc package does not install include files;
2839 attempting to build U-Boot will fail because <machine/ansi.h> is
2840 missing. This file has to be installed and patched manually:
2842 # cd /usr/pkg/cross/powerpc-netbsd/include
2844 # ln -s powerpc machine
2845 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
2846 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
2848 Native builds *don't* work due to incompatibilities between native
2849 and U-Boot include files.
2851 Booting assumes that (the first part of) the image booted is a
2852 stage-2 loader which in turn loads and then invokes the kernel
2853 proper. Loader sources will eventually appear in the NetBSD source
2854 tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
2855 meantime, send mail to bruno@exet-ag.de and/or wd@denx.de for
2859 Implementation Internals:
2860 =========================
2862 The following is not intended to be a complete description of every
2863 implementation detail. However, it should help to understand the
2864 inner workings of U-Boot and make it easier to port it to custom
2868 Initial Stack, Global Data:
2869 ---------------------------
2871 The implementation of U-Boot is complicated by the fact that U-Boot
2872 starts running out of ROM (flash memory), usually without access to
2873 system RAM (because the memory controller is not initialized yet).
2874 This means that we don't have writable Data or BSS segments, and BSS
2875 is not initialized as zero. To be able to get a C environment working
2876 at all, we have to allocate at least a minimal stack. Implementation
2877 options for this are defined and restricted by the CPU used: Some CPU
2878 models provide on-chip memory (like the IMMR area on MPC8xx and
2879 MPC826x processors), on others (parts of) the data cache can be
2880 locked as (mis-) used as memory, etc.
2882 Chris Hallinan posted a good summary of these issues to the
2883 u-boot-users mailing list:
2885 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
2886 From: "Chris Hallinan" <clh@net1plus.com>
2887 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
2890 Correct me if I'm wrong, folks, but the way I understand it
2891 is this: Using DCACHE as initial RAM for Stack, etc, does not
2892 require any physical RAM backing up the cache. The cleverness
2893 is that the cache is being used as a temporary supply of
2894 necessary storage before the SDRAM controller is setup. It's
2895 beyond the scope of this list to expain the details, but you
2896 can see how this works by studying the cache architecture and
2897 operation in the architecture and processor-specific manuals.
2899 OCM is On Chip Memory, which I believe the 405GP has 4K. It
2900 is another option for the system designer to use as an
2901 initial stack/ram area prior to SDRAM being available. Either
2902 option should work for you. Using CS 4 should be fine if your
2903 board designers haven't used it for something that would
2904 cause you grief during the initial boot! It is frequently not
2907 CFG_INIT_RAM_ADDR should be somewhere that won't interfere
2908 with your processor/board/system design. The default value
2909 you will find in any recent u-boot distribution in
2910 Walnut405.h should work for you. I'd set it to a value larger
2911 than your SDRAM module. If you have a 64MB SDRAM module, set
2912 it above 400_0000. Just make sure your board has no resources
2913 that are supposed to respond to that address! That code in
2914 start.S has been around a while and should work as is when
2915 you get the config right.
2920 It is essential to remember this, since it has some impact on the C
2921 code for the initialization procedures:
2923 * Initialized global data (data segment) is read-only. Do not attempt
2926 * Do not use any unitialized global data (or implicitely initialized
2927 as zero data - BSS segment) at all - this is undefined, initiali-
2928 zation is performed later (when relocating to RAM).
2930 * Stack space is very limited. Avoid big data buffers or things like
2933 Having only the stack as writable memory limits means we cannot use
2934 normal global data to share information beween the code. But it
2935 turned out that the implementation of U-Boot can be greatly
2936 simplified by making a global data structure (gd_t) available to all
2937 functions. We could pass a pointer to this data as argument to _all_
2938 functions, but this would bloat the code. Instead we use a feature of
2939 the GCC compiler (Global Register Variables) to share the data: we
2940 place a pointer (gd) to the global data into a register which we
2941 reserve for this purpose.
2943 When choosing a register for such a purpose we are restricted by the
2944 relevant (E)ABI specifications for the current architecture, and by
2945 GCC's implementation.
2947 For PowerPC, the following registers have specific use:
2950 R3-R4: parameter passing and return values
2951 R5-R10: parameter passing
2952 R13: small data area pointer
2956 (U-Boot also uses R14 as internal GOT pointer.)
2958 ==> U-Boot will use R29 to hold a pointer to the global data
2960 Note: on PPC, we could use a static initializer (since the
2961 address of the global data structure is known at compile time),
2962 but it turned out that reserving a register results in somewhat
2963 smaller code - although the code savings are not that big (on
2964 average for all boards 752 bytes for the whole U-Boot image,
2965 624 text + 127 data).
2967 On ARM, the following registers are used:
2969 R0: function argument word/integer result
2970 R1-R3: function argument word
2972 R10: stack limit (used only if stack checking if enabled)
2973 R11: argument (frame) pointer
2974 R12: temporary workspace
2977 R15: program counter
2979 ==> U-Boot will use R8 to hold a pointer to the global data
2985 U-Boot runs in system state and uses physical addresses, i.e. the
2986 MMU is not used either for address mapping nor for memory protection.
2988 The available memory is mapped to fixed addresses using the memory
2989 controller. In this process, a contiguous block is formed for each
2990 memory type (Flash, SDRAM, SRAM), even when it consists of several
2991 physical memory banks.
2993 U-Boot is installed in the first 128 kB of the first Flash bank (on
2994 TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
2995 booting and sizing and initializing DRAM, the code relocates itself
2996 to the upper end of DRAM. Immediately below the U-Boot code some
2997 memory is reserved for use by malloc() [see CFG_MALLOC_LEN
2998 configuration setting]. Below that, a structure with global Board
2999 Info data is placed, followed by the stack (growing downward).
3001 Additionally, some exception handler code is copied to the low 8 kB
3002 of DRAM (0x00000000 ... 0x00001FFF).
3004 So a typical memory configuration with 16 MB of DRAM could look like
3007 0x0000 0000 Exception Vector code
3010 0x0000 2000 Free for Application Use
3016 0x00FB FF20 Monitor Stack (Growing downward)
3017 0x00FB FFAC Board Info Data and permanent copy of global data
3018 0x00FC 0000 Malloc Arena
3021 0x00FE 0000 RAM Copy of Monitor Code
3022 ... eventually: LCD or video framebuffer
3023 ... eventually: pRAM (Protected RAM - unchanged by reset)
3024 0x00FF FFFF [End of RAM]
3027 System Initialization:
3028 ----------------------
3030 In the reset configuration, U-Boot starts at the reset entry point
3031 (on most PowerPC systens at address 0x00000100). Because of the reset
3032 configuration for CS0# this is a mirror of the onboard Flash memory.
3033 To be able to re-map memory U-Boot then jumps to its link address.
3034 To be able to implement the initialization code in C, a (small!)
3035 initial stack is set up in the internal Dual Ported RAM (in case CPUs
3036 which provide such a feature like MPC8xx or MPC8260), or in a locked
3037 part of the data cache. After that, U-Boot initializes the CPU core,
3038 the caches and the SIU.
3040 Next, all (potentially) available memory banks are mapped using a
3041 preliminary mapping. For example, we put them on 512 MB boundaries
3042 (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
3043 on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
3044 programmed for SDRAM access. Using the temporary configuration, a
3045 simple memory test is run that determines the size of the SDRAM
3048 When there is more than one SDRAM bank, and the banks are of
3049 different size, the largest is mapped first. For equal size, the first
3050 bank (CS2#) is mapped first. The first mapping is always for address
3051 0x00000000, with any additional banks following immediately to create
3052 contiguous memory starting from 0.
3054 Then, the monitor installs itself at the upper end of the SDRAM area
3055 and allocates memory for use by malloc() and for the global Board
3056 Info data; also, the exception vector code is copied to the low RAM
3057 pages, and the final stack is set up.
3059 Only after this relocation will you have a "normal" C environment;
3060 until that you are restricted in several ways, mostly because you are
3061 running from ROM, and because the code will have to be relocated to a
3065 U-Boot Porting Guide:
3066 ----------------------
3068 [Based on messages by Jerry Van Baren in the U-Boot-Users mailing
3072 int main (int argc, char *argv[])
3074 sighandler_t no_more_time;
3076 signal (SIGALRM, no_more_time);
3077 alarm (PROJECT_DEADLINE - toSec (3 * WEEK));
3079 if (available_money > available_manpower) {
3080 pay consultant to port U-Boot;
3084 Download latest U-Boot source;
3086 Subscribe to u-boot-users mailing list;
3089 email ("Hi, I am new to U-Boot, how do I get started?");
3093 Read the README file in the top level directory;
3094 Read http://www.denx.de/re/DPLG.html
3095 Read the source, Luke;
3098 if (available_money > toLocalCurrency ($2500)) {
3101 Add a lot of aggravation and time;
3104 Create your own board support subdirectory;
3106 Create your own board config file;
3110 Add / modify source code;
3114 email ("Hi, I am having problems...");
3116 Send patch file to Wolfgang;
3121 void no_more_time (int sig)
3130 All contributions to U-Boot should conform to the Linux kernel
3131 coding style; see the file "Documentation/CodingStyle" in your Linux
3132 kernel source directory.
3134 Please note that U-Boot is implemented in C (and to some small parts
3135 in Assembler); no C++ is used, so please do not use C++ style
3136 comments (//) in your code.
3138 Submissions which do not conform to the standards may be returned
3139 with a request to reformat the changes.
3145 Since the number of patches for U-Boot is growing, we need to
3146 establish some rules. Submissions which do not conform to these rules
3147 may be rejected, even when they contain important and valuable stuff.
3150 When you send a patch, please include the following information with
3153 * For bug fixes: a description of the bug and how your patch fixes
3154 this bug. Please try to include a way of demonstrating that the
3155 patch actually fixes something.
3157 * For new features: a description of the feature and your
3160 * A CHANGELOG entry as plaintext (separate from the patch)
3162 * For major contributions, your entry to the CREDITS file
3164 * When you add support for a new board, don't forget to add this
3165 board to the MAKEALL script, too.
3167 * If your patch adds new configuration options, don't forget to
3168 document these in the README file.
3170 * The patch itself. If you are accessing the CVS repository use "cvs
3171 update; cvs diff -puRN"; else, use "diff -purN OLD NEW". If your
3172 version of diff does not support these options, then get the latest
3173 version of GNU diff.
3175 The current directory when running this command shall be the top
3176 level directory of the U-Boot source tree, or it's parent directory
3177 (i. e. please make sure that your patch includes sufficient
3178 directory information for the affected files).
3180 We accept patches as plain text, MIME attachments or as uuencoded
3183 * If one logical set of modifications affects or creates several
3184 files, all these changes shall be submitted in a SINGLE patch file.
3186 * Changesets that contain different, unrelated modifications shall be
3187 submitted as SEPARATE patches, one patch per changeset.
3192 * Before sending the patch, run the MAKEALL script on your patched
3193 source tree and make sure that no errors or warnings are reported
3194 for any of the boards.
3196 * Keep your modifications to the necessary minimum: A patch
3197 containing several unrelated changes or arbitrary reformats will be
3198 returned with a request to re-formatting / split it.
3200 * If you modify existing code, make sure that your new code does not
3201 add to the memory footprint of the code ;-) Small is beautiful!
3202 When adding new features, these should compile conditionally only
3203 (using #ifdef), and the resulting code with the new feature
3204 disabled must not need more memory than the old code without your
projects / platform / kernel / u-boot.git / blob