2 # (C) Copyright 2000 - 2005
3 # Wolfgang Denk, DENX Software Engineering, wd@denx.de.
5 # See file CREDITS for list of people who contributed to this
8 # This program is free software; you can redistribute it and/or
9 # modify it under the terms of the GNU General Public License as
10 # published by the Free Software Foundation; either version 2 of
11 # the License, or (at your option) any later version.
13 # This program is distributed in the hope that it will be useful,
14 # but WITHOUT ANY WARRANTY; without even the implied warranty of
15 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 # GNU General Public License for more details.
18 # You should have received a copy of the GNU General Public License
19 # along with this program; if not, write to the Free Software
20 # Foundation, Inc., 59 Temple Place, Suite 330, Boston,
27 This directory contains the source code for U-Boot, a boot loader for
28 Embedded boards based on PowerPC, ARM, MIPS and several other
29 processors, which can be installed in a boot ROM and used to
30 initialize and test the hardware or to download and run application
33 The development of U-Boot is closely related to Linux: some parts of
34 the source code originate in the Linux source tree, we have some
35 header files in common, and special provision has been made to
36 support booting of Linux images.
38 Some attention has been paid to make this software easily
39 configurable and extendable. For instance, all monitor commands are
40 implemented with the same call interface, so that it's very easy to
41 add new commands. Also, instead of permanently adding rarely used
42 code (for instance hardware test utilities) to the monitor, you can
43 load and run it dynamically.
49 In general, all boards for which a configuration option exists in the
50 Makefile have been tested to some extent and can be considered
51 "working". In fact, many of them are used in production systems.
53 In case of problems see the CHANGELOG and CREDITS files to find out
54 who contributed the specific port.
60 In case you have questions about, problems with or contributions for
61 U-Boot you should send a message to the U-Boot mailing list at
62 <u-boot-users@lists.sourceforge.net>. There is also an archive of
63 previous traffic on the mailing list - please search the archive
64 before asking FAQ's. Please see
65 http://lists.sourceforge.net/lists/listinfo/u-boot-users/
71 - start from 8xxrom sources
72 - create PPCBoot project (http://sourceforge.net/projects/ppcboot)
74 - make it easier to add custom boards
75 - make it possible to add other [PowerPC] CPUs
76 - extend functions, especially:
77 * Provide extended interface to Linux boot loader
80 * PCMCIA / CompactFLash / ATA disk / SCSI ... boot
81 - create ARMBoot project (http://sourceforge.net/projects/armboot)
82 - add other CPU families (starting with ARM)
83 - create U-Boot project (http://sourceforge.net/projects/u-boot)
89 The "official" name of this project is "Das U-Boot". The spelling
90 "U-Boot" shall be used in all written text (documentation, comments
91 in source files etc.). Example:
93 This is the README file for the U-Boot project.
95 File names etc. shall be based on the string "u-boot". Examples:
97 include/asm-ppc/u-boot.h
99 #include <asm/u-boot.h>
101 Variable names, preprocessor constants etc. shall be either based on
102 the string "u_boot" or on "U_BOOT". Example:
104 U_BOOT_VERSION u_boot_logo
105 IH_OS_U_BOOT u_boot_hush_start
111 U-Boot uses a 3 level version number containing a version, a
112 sub-version, and a patchlevel: "U-Boot-2.34.5" means version "2",
113 sub-version "34", and patchlevel "4".
115 The patchlevel is used to indicate certain stages of development
116 between released versions, i. e. officially released versions of
117 U-Boot will always have a patchlevel of "0".
123 - board Board dependent files
124 - common Misc architecture independent functions
125 - cpu CPU specific files
126 - 74xx_7xx Files specific to Freescale MPC74xx and 7xx CPUs
127 - arm720t Files specific to ARM 720 CPUs
128 - arm920t Files specific to ARM 920 CPUs
129 - at91rm9200 Files specific to Atmel AT91RM9200 CPU
130 - imx Files specific to Freescale MC9328 i.MX CPUs
131 - s3c24x0 Files specific to Samsung S3C24X0 CPUs
132 - arm925t Files specific to ARM 925 CPUs
133 - arm926ejs Files specific to ARM 926 CPUs
134 - arm1136 Files specific to ARM 1136 CPUs
135 - at32ap Files specific to Atmel AVR32 AP CPUs
136 - i386 Files specific to i386 CPUs
137 - ixp Files specific to Intel XScale IXP CPUs
138 - mcf52x2 Files specific to Freescale ColdFire MCF52x2 CPUs
139 - mips Files specific to MIPS CPUs
140 - mpc5xx Files specific to Freescale MPC5xx CPUs
141 - mpc5xxx Files specific to Freescale MPC5xxx CPUs
142 - mpc8xx Files specific to Freescale MPC8xx CPUs
143 - mpc8220 Files specific to Freescale MPC8220 CPUs
144 - mpc824x Files specific to Freescale MPC824x CPUs
145 - mpc8260 Files specific to Freescale MPC8260 CPUs
146 - mpc85xx Files specific to Freescale MPC85xx CPUs
147 - nios Files specific to Altera NIOS CPUs
148 - nios2 Files specific to Altera Nios-II CPUs
149 - ppc4xx Files specific to AMCC PowerPC 4xx CPUs
150 - pxa Files specific to Intel XScale PXA CPUs
151 - s3c44b0 Files specific to Samsung S3C44B0 CPUs
152 - sa1100 Files specific to Intel StrongARM SA1100 CPUs
153 - disk Code for disk drive partition handling
154 - doc Documentation (don't expect too much)
155 - drivers Commonly used device drivers
156 - dtt Digital Thermometer and Thermostat drivers
157 - examples Example code for standalone applications, etc.
158 - include Header Files
159 - lib_arm Files generic to ARM architecture
160 - lib_avr32 Files generic to AVR32 architecture
161 - lib_generic Files generic to all architectures
162 - lib_i386 Files generic to i386 architecture
163 - lib_m68k Files generic to m68k architecture
164 - lib_mips Files generic to MIPS architecture
165 - lib_nios Files generic to NIOS architecture
166 - lib_ppc Files generic to PowerPC architecture
167 - libfdt Library files to support flattened device trees
168 - net Networking code
169 - post Power On Self Test
170 - rtc Real Time Clock drivers
171 - tools Tools to build S-Record or U-Boot images, etc.
173 Software Configuration:
174 =======================
176 Configuration is usually done using C preprocessor defines; the
177 rationale behind that is to avoid dead code whenever possible.
179 There are two classes of configuration variables:
181 * Configuration _OPTIONS_:
182 These are selectable by the user and have names beginning with
185 * Configuration _SETTINGS_:
186 These depend on the hardware etc. and should not be meddled with if
187 you don't know what you're doing; they have names beginning with
190 Later we will add a configuration tool - probably similar to or even
191 identical to what's used for the Linux kernel. Right now, we have to
192 do the configuration by hand, which means creating some symbolic
193 links and editing some configuration files. We use the TQM8xxL boards
197 Selection of Processor Architecture and Board Type:
198 ---------------------------------------------------
200 For all supported boards there are ready-to-use default
201 configurations available; just type "make <board_name>_config".
203 Example: For a TQM823L module type:
208 For the Cogent platform, you need to specify the cpu type as well;
209 e.g. "make cogent_mpc8xx_config". And also configure the cogent
210 directory according to the instructions in cogent/README.
213 Configuration Options:
214 ----------------------
216 Configuration depends on the combination of board and CPU type; all
217 such information is kept in a configuration file
218 "include/configs/<board_name>.h".
220 Example: For a TQM823L module, all configuration settings are in
221 "include/configs/TQM823L.h".
224 Many of the options are named exactly as the corresponding Linux
225 kernel configuration options. The intention is to make it easier to
226 build a config tool - later.
229 The following options need to be configured:
231 - CPU Type: Define exactly one of
235 CONFIG_MPC823, CONFIG_MPC850, CONFIG_MPC855, CONFIG_MPC860
238 or CONFIG_MPC824X, CONFIG_MPC8260
255 MicroBlaze based CPUs:
256 ----------------------
260 ----------------------
264 ----------------------
267 - Board Type: Define exactly one of
269 PowerPC based boards:
270 ---------------------
272 CONFIG_ADCIOP CONFIG_FPS860L CONFIG_OXC
273 CONFIG_ADS860 CONFIG_GEN860T CONFIG_PCI405
274 CONFIG_AMX860 CONFIG_GENIETV CONFIG_PCIPPC2
275 CONFIG_AP1000 CONFIG_GTH CONFIG_PCIPPC6
276 CONFIG_AR405 CONFIG_gw8260 CONFIG_pcu_e
277 CONFIG_BAB7xx CONFIG_hermes CONFIG_PIP405
278 CONFIG_BC3450 CONFIG_hymod CONFIG_PM826
279 CONFIG_c2mon CONFIG_IAD210 CONFIG_ppmc8260
280 CONFIG_CANBT CONFIG_ICU862 CONFIG_QS823
281 CONFIG_CCM CONFIG_IP860 CONFIG_QS850
282 CONFIG_CMI CONFIG_IPHASE4539 CONFIG_QS860T
283 CONFIG_cogent_mpc8260 CONFIG_IVML24 CONFIG_RBC823
284 CONFIG_cogent_mpc8xx CONFIG_IVML24_128 CONFIG_RPXClassic
285 CONFIG_CPCI405 CONFIG_IVML24_256 CONFIG_RPXlite
286 CONFIG_CPCI4052 CONFIG_IVMS8 CONFIG_RPXsuper
287 CONFIG_CPCIISER4 CONFIG_IVMS8_128 CONFIG_rsdproto
288 CONFIG_CPU86 CONFIG_IVMS8_256 CONFIG_sacsng
289 CONFIG_CRAYL1 CONFIG_JSE CONFIG_Sandpoint8240
290 CONFIG_CSB272 CONFIG_LANTEC CONFIG_Sandpoint8245
291 CONFIG_CU824 CONFIG_LITE5200B CONFIG_sbc8260
292 CONFIG_DASA_SIM CONFIG_lwmon CONFIG_sbc8560
293 CONFIG_DB64360 CONFIG_MBX CONFIG_SM850
294 CONFIG_DB64460 CONFIG_MBX860T CONFIG_SPD823TS
295 CONFIG_DU405 CONFIG_MHPC CONFIG_STXGP3
296 CONFIG_DUET_ADS CONFIG_MIP405 CONFIG_SXNI855T
297 CONFIG_EBONY CONFIG_MOUSSE CONFIG_TQM823L
298 CONFIG_ELPPC CONFIG_MPC8260ADS CONFIG_TQM8260
299 CONFIG_ELPT860 CONFIG_MPC8540ADS CONFIG_TQM850L
300 CONFIG_ep8260 CONFIG_MPC8540EVAL CONFIG_TQM855L
301 CONFIG_ERIC CONFIG_MPC8560ADS CONFIG_TQM860L
302 CONFIG_ESTEEM192E CONFIG_MUSENKI CONFIG_TTTech
303 CONFIG_ETX094 CONFIG_MVS1 CONFIG_UTX8245
304 CONFIG_EVB64260 CONFIG_NETPHONE CONFIG_V37
305 CONFIG_FADS823 CONFIG_NETTA CONFIG_W7OLMC
306 CONFIG_FADS850SAR CONFIG_NETVIA CONFIG_W7OLMG
307 CONFIG_FADS860T CONFIG_NX823 CONFIG_WALNUT
308 CONFIG_FLAGADM CONFIG_OCRTC CONFIG_ZPC1900
309 CONFIG_FPS850L CONFIG_ORSG CONFIG_ZUMA
314 CONFIG_ARMADILLO, CONFIG_AT91RM9200DK, CONFIG_CERF250,
315 CONFIG_CSB637, CONFIG_DELTA, CONFIG_DNP1110,
316 CONFIG_EP7312, CONFIG_H2_OMAP1610, CONFIG_HHP_CRADLE,
317 CONFIG_IMPA7, CONFIG_INNOVATOROMAP1510, CONFIG_INNOVATOROMAP1610,
318 CONFIG_KB9202, CONFIG_LART, CONFIG_LPD7A400,
319 CONFIG_LUBBOCK, CONFIG_OSK_OMAP5912, CONFIG_OMAP2420H4,
320 CONFIG_PLEB2, CONFIG_SHANNON, CONFIG_P2_OMAP730,
321 CONFIG_SMDK2400, CONFIG_SMDK2410, CONFIG_TRAB,
324 MicroBlaze based boards:
325 ------------------------
330 ------------------------
332 CONFIG_PCI5441 CONFIG_PK1C20
333 CONFIG_EP1C20 CONFIG_EP1S10 CONFIG_EP1S40
340 - CPU Daughterboard Type: (if CONFIG_ATSTK1000 is defined)
341 Define exactly one of
345 - CPU Module Type: (if CONFIG_COGENT is defined)
346 Define exactly one of
348 --- FIXME --- not tested yet:
349 CONFIG_CMA286_60, CONFIG_CMA286_21, CONFIG_CMA286_60P,
350 CONFIG_CMA287_23, CONFIG_CMA287_50
352 - Motherboard Type: (if CONFIG_COGENT is defined)
353 Define exactly one of
354 CONFIG_CMA101, CONFIG_CMA102
356 - Motherboard I/O Modules: (if CONFIG_COGENT is defined)
357 Define one or more of
360 - Motherboard Options: (if CONFIG_CMA101 or CONFIG_CMA102 are defined)
361 Define one or more of
362 CONFIG_LCD_HEARTBEAT - update a character position on
363 the lcd display every second with
366 - Board flavour: (if CONFIG_MPC8260ADS is defined)
369 CFG_8260ADS - original MPC8260ADS
370 CFG_8266ADS - MPC8266ADS
371 CFG_PQ2FADS - PQ2FADS-ZU or PQ2FADS-VR
372 CFG_8272ADS - MPC8272ADS
374 - MPC824X Family Member (if CONFIG_MPC824X is defined)
375 Define exactly one of
376 CONFIG_MPC8240, CONFIG_MPC8245
378 - 8xx CPU Options: (if using an MPC8xx cpu)
379 CONFIG_8xx_GCLK_FREQ - deprecated: CPU clock if
380 get_gclk_freq() cannot work
381 e.g. if there is no 32KHz
382 reference PIT/RTC clock
383 CONFIG_8xx_OSCLK - PLL input clock (either EXTCLK
386 - 859/866/885 CPU options: (if using a MPC859 or MPC866 or MPC885 CPU):
389 CONFIG_8xx_CPUCLK_DEFAULT
390 See doc/README.MPC866
394 Define this to measure the actual CPU clock instead
395 of relying on the correctness of the configured
396 values. Mostly useful for board bringup to make sure
397 the PLL is locked at the intended frequency. Note
398 that this requires a (stable) reference clock (32 kHz
399 RTC clock or CFG_8XX_XIN)
401 - Intel Monahans options:
402 CFG_MONAHANS_RUN_MODE_OSC_RATIO
404 Defines the Monahans run mode to oscillator
405 ratio. Valid values are 8, 16, 24, 31. The core
406 frequency is this value multiplied by 13 MHz.
408 CFG_MONAHANS_TURBO_RUN_MODE_RATIO
410 Defines the Monahans turbo mode to oscillator
411 ratio. Valid values are 1 (default if undefined) and
412 2. The core frequency as calculated above is multiplied
415 - Linux Kernel Interface:
418 U-Boot stores all clock information in Hz
419 internally. For binary compatibility with older Linux
420 kernels (which expect the clocks passed in the
421 bd_info data to be in MHz) the environment variable
422 "clocks_in_mhz" can be defined so that U-Boot
423 converts clock data to MHZ before passing it to the
425 When CONFIG_CLOCKS_IN_MHZ is defined, a definition of
426 "clocks_in_mhz=1" is automatically included in the
429 CONFIG_MEMSIZE_IN_BYTES [relevant for MIPS only]
431 When transfering memsize parameter to linux, some versions
432 expect it to be in bytes, others in MB.
433 Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes.
435 CONFIG_OF_LIBFDT / CONFIG_OF_FLAT_TREE
437 New kernel versions are expecting firmware settings to be
438 passed using flattened device trees (based on open firmware
442 * New libfdt-based support
443 * Adds the "fdt" command
444 * The bootm command does _not_ modify the fdt
447 * Deprecated, see CONFIG_OF_LIBFDT
448 * Original ft_build.c-based support
449 * Automatically modifies the dft as part of the bootm command
450 * The environment variable "disable_of", when set,
451 disables this functionality.
453 CONFIG_OF_FLAT_TREE_MAX_SIZE
455 The maximum size of the constructed OF tree.
457 OF_CPU - The proper name of the cpus node.
458 OF_SOC - The proper name of the soc node.
459 OF_TBCLK - The timebase frequency.
460 OF_STDOUT_PATH - The path to the console device
464 * CONFIG_OF_LIBFDT - enables the "fdt bd_t" command
465 * CONFIG_OF_FLAT_TREE - The resulting flat device tree
466 will have a copy of the bd_t. Space should be
467 pre-allocated in the dts for the bd_t.
469 CONFIG_OF_HAS_UBOOT_ENV
471 * CONFIG_OF_LIBFDT - enables the "fdt bd_t" command
472 * CONFIG_OF_FLAT_TREE - The resulting flat device tree
473 will have a copy of u-boot's environment variables
475 CONFIG_OF_BOARD_SETUP
477 Board code has addition modification that it wants to make
478 to the flat device tree before handing it off to the kernel
482 This define fills in the correct boot cpu in the boot
483 param header, the default value is zero if undefined.
488 Define this if you want support for Amba PrimeCell PL010 UARTs.
492 Define this if you want support for Amba PrimeCell PL011 UARTs.
496 If you have Amba PrimeCell PL011 UARTs, set this variable to
497 the clock speed of the UARTs.
501 If you have Amba PrimeCell PL010 or PL011 UARTs on your board,
502 define this to a list of base addresses for each (supported)
503 port. See e.g. include/configs/versatile.h
507 Depending on board, define exactly one serial port
508 (like CONFIG_8xx_CONS_SMC1, CONFIG_8xx_CONS_SMC2,
509 CONFIG_8xx_CONS_SCC1, ...), or switch off the serial
510 console by defining CONFIG_8xx_CONS_NONE
512 Note: if CONFIG_8xx_CONS_NONE is defined, the serial
513 port routines must be defined elsewhere
514 (i.e. serial_init(), serial_getc(), ...)
517 Enables console device for a color framebuffer. Needs following
518 defines (cf. smiLynxEM, i8042, board/eltec/bab7xx)
519 VIDEO_FB_LITTLE_ENDIAN graphic memory organisation
521 VIDEO_HW_RECTFILL graphic chip supports
524 VIDEO_HW_BITBLT graphic chip supports
525 bit-blit (cf. smiLynxEM)
526 VIDEO_VISIBLE_COLS visible pixel columns
528 VIDEO_VISIBLE_ROWS visible pixel rows
529 VIDEO_PIXEL_SIZE bytes per pixel
530 VIDEO_DATA_FORMAT graphic data format
531 (0-5, cf. cfb_console.c)
532 VIDEO_FB_ADRS framebuffer address
533 VIDEO_KBD_INIT_FCT keyboard int fct
534 (i.e. i8042_kbd_init())
535 VIDEO_TSTC_FCT test char fct
537 VIDEO_GETC_FCT get char fct
539 CONFIG_CONSOLE_CURSOR cursor drawing on/off
540 (requires blink timer
542 CFG_CONSOLE_BLINK_COUNT blink interval (cf. i8042.c)
543 CONFIG_CONSOLE_TIME display time/date info in
545 (requires CONFIG_CMD_DATE)
546 CONFIG_VIDEO_LOGO display Linux logo in
548 CONFIG_VIDEO_BMP_LOGO use bmp_logo.h instead of
549 linux_logo.h for logo.
550 Requires CONFIG_VIDEO_LOGO
551 CONFIG_CONSOLE_EXTRA_INFO
552 addional board info beside
555 When CONFIG_CFB_CONSOLE is defined, video console is
556 default i/o. Serial console can be forced with
557 environment 'console=serial'.
559 When CONFIG_SILENT_CONSOLE is defined, all console
560 messages (by U-Boot and Linux!) can be silenced with
561 the "silent" environment variable. See
562 doc/README.silent for more information.
565 CONFIG_BAUDRATE - in bps
566 Select one of the baudrates listed in
567 CFG_BAUDRATE_TABLE, see below.
568 CFG_BRGCLK_PRESCALE, baudrate prescale
570 - Interrupt driven serial port input:
571 CONFIG_SERIAL_SOFTWARE_FIFO
574 Use an interrupt handler for receiving data on the
575 serial port. It also enables using hardware handshake
576 (RTS/CTS) and UART's built-in FIFO. Set the number of
577 bytes the interrupt driven input buffer should have.
579 Leave undefined to disable this feature, including
580 disable the buffer and hardware handshake.
582 - Console UART Number:
586 If defined internal UART1 (and not UART0) is used
587 as default U-Boot console.
589 - Boot Delay: CONFIG_BOOTDELAY - in seconds
590 Delay before automatically booting the default image;
591 set to -1 to disable autoboot.
593 See doc/README.autoboot for these options that
594 work with CONFIG_BOOTDELAY. None are required.
595 CONFIG_BOOT_RETRY_TIME
596 CONFIG_BOOT_RETRY_MIN
597 CONFIG_AUTOBOOT_KEYED
598 CONFIG_AUTOBOOT_PROMPT
599 CONFIG_AUTOBOOT_DELAY_STR
600 CONFIG_AUTOBOOT_STOP_STR
601 CONFIG_AUTOBOOT_DELAY_STR2
602 CONFIG_AUTOBOOT_STOP_STR2
603 CONFIG_ZERO_BOOTDELAY_CHECK
604 CONFIG_RESET_TO_RETRY
608 Only needed when CONFIG_BOOTDELAY is enabled;
609 define a command string that is automatically executed
610 when no character is read on the console interface
611 within "Boot Delay" after reset.
614 This can be used to pass arguments to the bootm
615 command. The value of CONFIG_BOOTARGS goes into the
616 environment value "bootargs".
618 CONFIG_RAMBOOT and CONFIG_NFSBOOT
619 The value of these goes into the environment as
620 "ramboot" and "nfsboot" respectively, and can be used
621 as a convenience, when switching between booting from
627 When this option is #defined, the existence of the
628 environment variable "preboot" will be checked
629 immediately before starting the CONFIG_BOOTDELAY
630 countdown and/or running the auto-boot command resp.
631 entering interactive mode.
633 This feature is especially useful when "preboot" is
634 automatically generated or modified. For an example
635 see the LWMON board specific code: here "preboot" is
636 modified when the user holds down a certain
637 combination of keys on the (special) keyboard when
640 - Serial Download Echo Mode:
642 If defined to 1, all characters received during a
643 serial download (using the "loads" command) are
644 echoed back. This might be needed by some terminal
645 emulations (like "cu"), but may as well just take
646 time on others. This setting #define's the initial
647 value of the "loads_echo" environment variable.
649 - Kgdb Serial Baudrate: (if CONFIG_CMD_KGDB is defined)
651 Select one of the baudrates listed in
652 CFG_BAUDRATE_TABLE, see below.
655 Monitor commands can be included or excluded
656 from the build by using the #include files
657 "config_cmd_all.h" and #undef'ing unwanted
658 commands, or using "config_cmd_default.h"
659 and augmenting with additional #define's
662 The default command configuration includes all commands
663 except those marked below with a "*".
665 CONFIG_CMD_ASKENV * ask for env variable
666 CONFIG_CMD_AUTOSCRIPT Autoscript Support
667 CONFIG_CMD_BDI bdinfo
668 CONFIG_CMD_BEDBUG * Include BedBug Debugger
669 CONFIG_CMD_BMP * BMP support
670 CONFIG_CMD_BSP * Board specific commands
671 CONFIG_CMD_BOOTD bootd
672 CONFIG_CMD_CACHE * icache, dcache
673 CONFIG_CMD_CONSOLE coninfo
674 CONFIG_CMD_DATE * support for RTC, date/time...
675 CONFIG_CMD_DHCP * DHCP support
676 CONFIG_CMD_DIAG * Diagnostics
677 CONFIG_CMD_DOC * Disk-On-Chip Support
678 CONFIG_CMD_DTT * Digital Therm and Thermostat
679 CONFIG_CMD_ECHO echo arguments
680 CONFIG_CMD_EEPROM * EEPROM read/write support
681 CONFIG_CMD_ELF * bootelf, bootvx
682 CONFIG_CMD_ENV saveenv
683 CONFIG_CMD_FDC * Floppy Disk Support
684 CONFIG_CMD_FAT * FAT partition support
685 CONFIG_CMD_FDOS * Dos diskette Support
686 CONFIG_CMD_FLASH flinfo, erase, protect
687 CONFIG_CMD_FPGA FPGA device initialization support
688 CONFIG_CMD_HWFLOW * RTS/CTS hw flow control
689 CONFIG_CMD_I2C * I2C serial bus support
690 CONFIG_CMD_IDE * IDE harddisk support
691 CONFIG_CMD_IMI iminfo
692 CONFIG_CMD_IMLS List all found images
693 CONFIG_CMD_IMMAP * IMMR dump support
694 CONFIG_CMD_IRQ * irqinfo
695 CONFIG_CMD_ITEST Integer/string test of 2 values
696 CONFIG_CMD_JFFS2 * JFFS2 Support
697 CONFIG_CMD_KGDB * kgdb
698 CONFIG_CMD_LOADB loadb
699 CONFIG_CMD_LOADS loads
700 CONFIG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base,
702 CONFIG_CMD_MISC Misc functions like sleep etc
703 CONFIG_CMD_MMC * MMC memory mapped support
704 CONFIG_CMD_MII * MII utility commands
705 CONFIG_CMD_NAND * NAND support
706 CONFIG_CMD_NET bootp, tftpboot, rarpboot
707 CONFIG_CMD_PCI * pciinfo
708 CONFIG_CMD_PCMCIA * PCMCIA support
709 CONFIG_CMD_PING * send ICMP ECHO_REQUEST to network
711 CONFIG_CMD_PORTIO * Port I/O
712 CONFIG_CMD_REGINFO * Register dump
713 CONFIG_CMD_RUN run command in env variable
714 CONFIG_CMD_SAVES * save S record dump
715 CONFIG_CMD_SCSI * SCSI Support
716 CONFIG_CMD_SDRAM * print SDRAM configuration information
717 (requires CONFIG_CMD_I2C)
718 CONFIG_CMD_SETGETDCR Support for DCR Register access
720 CONFIG_CMD_SPI * SPI serial bus support
721 CONFIG_CMD_USB * USB support
722 CONFIG_CMD_VFD * VFD support (TRAB)
723 CONFIG_CMD_BSP * Board SPecific functions
724 CONFIG_CMD_CDP * Cisco Discover Protocol support
725 CONFIG_CMD_FSL * Microblaze FSL support
728 EXAMPLE: If you want all functions except of network
729 support you can write:
731 #include "config_cmd_all.h"
732 #undef CONFIG_CMD_NET
735 fdt (flattened device tree) command: CONFIG_OF_LIBFDT
737 Note: Don't enable the "icache" and "dcache" commands
738 (configuration option CONFIG_CMD_CACHE) unless you know
739 what you (and your U-Boot users) are doing. Data
740 cache cannot be enabled on systems like the 8xx or
741 8260 (where accesses to the IMMR region must be
742 uncached), and it cannot be disabled on all other
743 systems where we (mis-) use the data cache to hold an
744 initial stack and some data.
747 XXX - this list needs to get updated!
751 If this variable is defined, it enables watchdog
752 support. There must be support in the platform specific
753 code for a watchdog. For the 8xx and 8260 CPUs, the
754 SIU Watchdog feature is enabled in the SYPCR
758 CONFIG_VERSION_VARIABLE
759 If this variable is defined, an environment variable
760 named "ver" is created by U-Boot showing the U-Boot
761 version as printed by the "version" command.
762 This variable is readonly.
766 When CONFIG_CMD_DATE is selected, the type of the RTC
767 has to be selected, too. Define exactly one of the
770 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx
771 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC
772 CONFIG_RTC_MC146818 - use MC146818 RTC
773 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC
774 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC
775 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC
776 CONFIG_RTC_DS164x - use Dallas DS164x RTC
777 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC
779 Note that if the RTC uses I2C, then the I2C interface
780 must also be configured. See I2C Support, below.
784 When CONFIG_TIMESTAMP is selected, the timestamp
785 (date and time) of an image is printed by image
786 commands like bootm or iminfo. This option is
787 automatically enabled when you select CONFIG_CMD_DATE .
790 CONFIG_MAC_PARTITION and/or CONFIG_DOS_PARTITION
791 and/or CONFIG_ISO_PARTITION
793 If IDE or SCSI support is enabled (CONFIG_CMD_IDE or
794 CONFIG_CMD_SCSI) you must configure support for at least
795 one partition type as well.
798 CONFIG_IDE_RESET_ROUTINE - this is defined in several
799 board configurations files but used nowhere!
801 CONFIG_IDE_RESET - is this is defined, IDE Reset will
802 be performed by calling the function
803 ide_set_reset(int reset)
804 which has to be defined in a board specific file
809 Set this to enable ATAPI support.
814 Set this to enable support for disks larger than 137GB
815 Also look at CFG_64BIT_LBA ,CFG_64BIT_VSPRINTF and CFG_64BIT_STRTOUL
816 Whithout these , LBA48 support uses 32bit variables and will 'only'
817 support disks up to 2.1TB.
820 When enabled, makes the IDE subsystem use 64bit sector addresses.
824 At the moment only there is only support for the
825 SYM53C8XX SCSI controller; define
826 CONFIG_SCSI_SYM53C8XX to enable it.
828 CFG_SCSI_MAX_LUN [8], CFG_SCSI_MAX_SCSI_ID [7] and
829 CFG_SCSI_MAX_DEVICE [CFG_SCSI_MAX_SCSI_ID *
830 CFG_SCSI_MAX_LUN] can be adjusted to define the
831 maximum numbers of LUNs, SCSI ID's and target
833 CFG_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz)
835 - NETWORK Support (PCI):
837 Support for Intel 8254x gigabit chips.
840 Support for Intel 82557/82559/82559ER chips.
841 Optional CONFIG_EEPRO100_SROM_WRITE enables eeprom
842 write routine for first time initialisation.
845 Support for Digital 2114x chips.
846 Optional CONFIG_TULIP_SELECT_MEDIA for board specific
847 modem chip initialisation (KS8761/QS6611).
850 Support for National dp83815 chips.
853 Support for National dp8382[01] gigabit chips.
855 - NETWORK Support (other):
857 CONFIG_DRIVER_LAN91C96
858 Support for SMSC's LAN91C96 chips.
861 Define this to hold the physical address
862 of the LAN91C96's I/O space
864 CONFIG_LAN91C96_USE_32_BIT
865 Define this to enable 32 bit addressing
867 CONFIG_DRIVER_SMC91111
868 Support for SMSC's LAN91C111 chip
871 Define this to hold the physical address
872 of the device (I/O space)
874 CONFIG_SMC_USE_32_BIT
875 Define this if data bus is 32 bits
877 CONFIG_SMC_USE_IOFUNCS
878 Define this to use i/o functions instead of macros
879 (some hardware wont work with macros)
882 At the moment only the UHCI host controller is
883 supported (PIP405, MIP405, MPC5200); define
884 CONFIG_USB_UHCI to enable it.
885 define CONFIG_USB_KEYBOARD to enable the USB Keyboard
886 and define CONFIG_USB_STORAGE to enable the USB
889 Supported are USB Keyboards and USB Floppy drives
891 MPC5200 USB requires additional defines:
893 for 528 MHz Clock: 0x0001bbbb
895 for differential drivers: 0x00001000
896 for single ended drivers: 0x00005000
898 May be defined to allow interrupt polling
899 instead of using asynchronous interrupts
902 Define the below if you wish to use the USB console.
903 Once firmware is rebuilt from a serial console issue the
904 command "setenv stdin usbtty; setenv stdout usbtty" and
905 attach your usb cable. The Unix command "dmesg" should print
906 it has found a new device. The environment variable usbtty
907 can be set to gserial or cdc_acm to enable your device to
908 appear to a USB host as a Linux gserial device or a
909 Common Device Class Abstract Control Model serial device.
910 If you select usbtty = gserial you should be able to enumerate
912 # modprobe usbserial vendor=0xVendorID product=0xProductID
913 else if using cdc_acm, simply setting the environment
914 variable usbtty to be cdc_acm should suffice. The following
915 might be defined in YourBoardName.h
918 Define this to build a UDC device
921 Define this to have a tty type of device available to
922 talk to the UDC device
924 CFG_CONSOLE_IS_IN_ENV
925 Define this if you want stdin, stdout &/or stderr to
929 CFG_USB_EXTC_CLK 0xBLAH
930 Derive USB clock from external clock "blah"
931 - CFG_USB_EXTC_CLK 0x02
933 CFG_USB_BRG_CLK 0xBLAH
934 Derive USB clock from brgclk
935 - CFG_USB_BRG_CLK 0x04
937 If you have a USB-IF assigned VendorID then you may wish to
938 define your own vendor specific values either in BoardName.h
939 or directly in usbd_vendor_info.h. If you don't define
940 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME,
941 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot
942 should pretend to be a Linux device to it's target host.
944 CONFIG_USBD_MANUFACTURER
945 Define this string as the name of your company for
946 - CONFIG_USBD_MANUFACTURER "my company"
948 CONFIG_USBD_PRODUCT_NAME
949 Define this string as the name of your product
950 - CONFIG_USBD_PRODUCT_NAME "acme usb device"
953 Define this as your assigned Vendor ID from the USB
954 Implementors Forum. This *must* be a genuine Vendor ID
955 to avoid polluting the USB namespace.
956 - CONFIG_USBD_VENDORID 0xFFFF
958 CONFIG_USBD_PRODUCTID
959 Define this as the unique Product ID
961 - CONFIG_USBD_PRODUCTID 0xFFFF
965 The MMC controller on the Intel PXA is supported. To
966 enable this define CONFIG_MMC. The MMC can be
967 accessed from the boot prompt by mapping the device
968 to physical memory similar to flash. Command line is
969 enabled with CONFIG_CMD_MMC. The MMC driver also works with
970 the FAT fs. This is enabled with CONFIG_CMD_FAT.
972 - Journaling Flash filesystem support:
973 CONFIG_JFFS2_NAND, CONFIG_JFFS2_NAND_OFF, CONFIG_JFFS2_NAND_SIZE,
974 CONFIG_JFFS2_NAND_DEV
975 Define these for a default partition on a NAND device
977 CFG_JFFS2_FIRST_SECTOR,
978 CFG_JFFS2_FIRST_BANK, CFG_JFFS2_NUM_BANKS
979 Define these for a default partition on a NOR device
982 Define this to create an own partition. You have to provide a
983 function struct part_info* jffs2_part_info(int part_num)
985 If you define only one JFFS2 partition you may also want to
986 #define CFG_JFFS_SINGLE_PART 1
987 to disable the command chpart. This is the default when you
988 have not defined a custom partition
993 Define this to enable standard (PC-Style) keyboard
997 Standard PC keyboard driver with US (is default) and
998 GERMAN key layout (switch via environment 'keymap=de') support.
999 Export function i8042_kbd_init, i8042_tstc and i8042_getc
1000 for cfb_console. Supports cursor blinking.
1005 Define this to enable video support (for output to
1008 CONFIG_VIDEO_CT69000
1010 Enable Chips & Technologies 69000 Video chip
1012 CONFIG_VIDEO_SMI_LYNXEM
1013 Enable Silicon Motion SMI 712/710/810 Video chip. The
1014 video output is selected via environment 'videoout'
1015 (1 = LCD and 2 = CRT). If videoout is undefined, CRT is
1018 For the CT69000 and SMI_LYNXEM drivers, videomode is
1019 selected via environment 'videomode'. Two diferent ways
1021 - "videomode=num" 'num' is a standard LiLo mode numbers.
1022 Following standard modes are supported (* is default):
1024 Colors 640x480 800x600 1024x768 1152x864 1280x1024
1025 -------------+---------------------------------------------
1026 8 bits | 0x301* 0x303 0x305 0x161 0x307
1027 15 bits | 0x310 0x313 0x316 0x162 0x319
1028 16 bits | 0x311 0x314 0x317 0x163 0x31A
1029 24 bits | 0x312 0x315 0x318 ? 0x31B
1030 -------------+---------------------------------------------
1031 (i.e. setenv videomode 317; saveenv; reset;)
1033 - "videomode=bootargs" all the video parameters are parsed
1034 from the bootargs. (See drivers/videomodes.c)
1037 CONFIG_VIDEO_SED13806
1038 Enable Epson SED13806 driver. This driver supports 8bpp
1039 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP
1040 or CONFIG_VIDEO_SED13806_16BPP
1045 Define this to enable a custom keyboard support.
1046 This simply calls drv_keyboard_init() which must be
1047 defined in your board-specific files.
1048 The only board using this so far is RBC823.
1050 - LCD Support: CONFIG_LCD
1052 Define this to enable LCD support (for output to LCD
1053 display); also select one of the supported displays
1054 by defining one of these:
1056 CONFIG_NEC_NL6448AC33:
1058 NEC NL6448AC33-18. Active, color, single scan.
1060 CONFIG_NEC_NL6448BC20
1062 NEC NL6448BC20-08. 6.5", 640x480.
1063 Active, color, single scan.
1065 CONFIG_NEC_NL6448BC33_54
1067 NEC NL6448BC33-54. 10.4", 640x480.
1068 Active, color, single scan.
1072 Sharp 320x240. Active, color, single scan.
1073 It isn't 16x9, and I am not sure what it is.
1075 CONFIG_SHARP_LQ64D341
1077 Sharp LQ64D341 display, 640x480.
1078 Active, color, single scan.
1082 HLD1045 display, 640x480.
1083 Active, color, single scan.
1087 Optrex CBL50840-2 NF-FW 99 22 M5
1089 Hitachi LMG6912RPFC-00T
1093 320x240. Black & white.
1095 Normally display is black on white background; define
1096 CFG_WHITE_ON_BLACK to get it inverted.
1098 - Splash Screen Support: CONFIG_SPLASH_SCREEN
1100 If this option is set, the environment is checked for
1101 a variable "splashimage". If found, the usual display
1102 of logo, copyright and system information on the LCD
1103 is suppressed and the BMP image at the address
1104 specified in "splashimage" is loaded instead. The
1105 console is redirected to the "nulldev", too. This
1106 allows for a "silent" boot where a splash screen is
1107 loaded very quickly after power-on.
1109 - Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP
1111 If this option is set, additionally to standard BMP
1112 images, gzipped BMP images can be displayed via the
1113 splashscreen support or the bmp command.
1115 - Compression support:
1118 If this option is set, support for bzip2 compressed
1119 images is included. If not, only uncompressed and gzip
1120 compressed images are supported.
1122 NOTE: the bzip2 algorithm requires a lot of RAM, so
1123 the malloc area (as defined by CFG_MALLOC_LEN) should
1129 The address of PHY on MII bus.
1131 CONFIG_PHY_CLOCK_FREQ (ppc4xx)
1133 The clock frequency of the MII bus
1137 If this option is set, support for speed/duplex
1138 detection of Gigabit PHY is included.
1140 CONFIG_PHY_RESET_DELAY
1142 Some PHY like Intel LXT971A need extra delay after
1143 reset before any MII register access is possible.
1144 For such PHY, set this option to the usec delay
1145 required. (minimum 300usec for LXT971A)
1147 CONFIG_PHY_CMD_DELAY (ppc4xx)
1149 Some PHY like Intel LXT971A need extra delay after
1150 command issued before MII status register can be read
1157 Define a default value for ethernet address to use
1158 for the respective ethernet interface, in case this
1159 is not determined automatically.
1164 Define a default value for the IP address to use for
1165 the default ethernet interface, in case this is not
1166 determined through e.g. bootp.
1168 - Server IP address:
1171 Defines a default value for theIP address of a TFTP
1172 server to contact when using the "tftboot" command.
1174 - BOOTP Recovery Mode:
1175 CONFIG_BOOTP_RANDOM_DELAY
1177 If you have many targets in a network that try to
1178 boot using BOOTP, you may want to avoid that all
1179 systems send out BOOTP requests at precisely the same
1180 moment (which would happen for instance at recovery
1181 from a power failure, when all systems will try to
1182 boot, thus flooding the BOOTP server. Defining
1183 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
1184 inserted before sending out BOOTP requests. The
1185 following delays are inserted then:
1187 1st BOOTP request: delay 0 ... 1 sec
1188 2nd BOOTP request: delay 0 ... 2 sec
1189 3rd BOOTP request: delay 0 ... 4 sec
1191 BOOTP requests: delay 0 ... 8 sec
1193 - DHCP Advanced Options:
1194 You can fine tune the DHCP functionality by defining
1195 CONFIG_BOOTP_* symbols:
1197 CONFIG_BOOTP_SUBNETMASK
1198 CONFIG_BOOTP_GATEWAY
1199 CONFIG_BOOTP_HOSTNAME
1200 CONFIG_BOOTP_NISDOMAIN
1201 CONFIG_BOOTP_BOOTPATH
1202 CONFIG_BOOTP_BOOTFILESIZE
1205 CONFIG_BOOTP_SEND_HOSTNAME
1206 CONFIG_BOOTP_NTPSERVER
1207 CONFIG_BOOTP_TIMEOFFSET
1208 CONFIG_BOOTP_VENDOREX
1210 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS
1211 serverip from a DHCP server, it is possible that more
1212 than one DNS serverip is offered to the client.
1213 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS
1214 serverip will be stored in the additional environment
1215 variable "dnsip2". The first DNS serverip is always
1216 stored in the variable "dnsip", when CONFIG_BOOTP_DNS
1219 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable
1220 to do a dynamic update of a DNS server. To do this, they
1221 need the hostname of the DHCP requester.
1222 If CONFIG_BOOP_SEND_HOSTNAME is defined, the content
1223 of the "hostname" environment variable is passed as
1224 option 12 to the DHCP server.
1227 CONFIG_CDP_DEVICE_ID
1229 The device id used in CDP trigger frames.
1231 CONFIG_CDP_DEVICE_ID_PREFIX
1233 A two character string which is prefixed to the MAC address
1238 A printf format string which contains the ascii name of
1239 the port. Normally is set to "eth%d" which sets
1240 eth0 for the first ethernet, eth1 for the second etc.
1242 CONFIG_CDP_CAPABILITIES
1244 A 32bit integer which indicates the device capabilities;
1245 0x00000010 for a normal host which does not forwards.
1249 An ascii string containing the version of the software.
1253 An ascii string containing the name of the platform.
1257 A 32bit integer sent on the trigger.
1259 CONFIG_CDP_POWER_CONSUMPTION
1261 A 16bit integer containing the power consumption of the
1262 device in .1 of milliwatts.
1264 CONFIG_CDP_APPLIANCE_VLAN_TYPE
1266 A byte containing the id of the VLAN.
1268 - Status LED: CONFIG_STATUS_LED
1270 Several configurations allow to display the current
1271 status using a LED. For instance, the LED will blink
1272 fast while running U-Boot code, stop blinking as
1273 soon as a reply to a BOOTP request was received, and
1274 start blinking slow once the Linux kernel is running
1275 (supported by a status LED driver in the Linux
1276 kernel). Defining CONFIG_STATUS_LED enables this
1279 - CAN Support: CONFIG_CAN_DRIVER
1281 Defining CONFIG_CAN_DRIVER enables CAN driver support
1282 on those systems that support this (optional)
1283 feature, like the TQM8xxL modules.
1285 - I2C Support: CONFIG_HARD_I2C | CONFIG_SOFT_I2C
1287 These enable I2C serial bus commands. Defining either of
1288 (but not both of) CONFIG_HARD_I2C or CONFIG_SOFT_I2C will
1289 include the appropriate I2C driver for the selected cpu.
1291 This will allow you to use i2c commands at the u-boot
1292 command line (as long as you set CONFIG_CMD_I2C in
1293 CONFIG_COMMANDS) and communicate with i2c based realtime
1294 clock chips. See common/cmd_i2c.c for a description of the
1295 command line interface.
1297 CONFIG_I2C_CMD_TREE is a recommended option that places
1298 all I2C commands under a single 'i2c' root command. The
1299 older 'imm', 'imd', 'iprobe' etc. commands are considered
1300 deprecated and may disappear in the future.
1302 CONFIG_HARD_I2C selects a hardware I2C controller.
1304 CONFIG_SOFT_I2C configures u-boot to use a software (aka
1305 bit-banging) driver instead of CPM or similar hardware
1308 There are several other quantities that must also be
1309 defined when you define CONFIG_HARD_I2C or CONFIG_SOFT_I2C.
1311 In both cases you will need to define CFG_I2C_SPEED
1312 to be the frequency (in Hz) at which you wish your i2c bus
1313 to run and CFG_I2C_SLAVE to be the address of this node (ie
1314 the cpu's i2c node address).
1316 Now, the u-boot i2c code for the mpc8xx (cpu/mpc8xx/i2c.c)
1317 sets the cpu up as a master node and so its address should
1318 therefore be cleared to 0 (See, eg, MPC823e User's Manual
1319 p.16-473). So, set CFG_I2C_SLAVE to 0.
1321 That's all that's required for CONFIG_HARD_I2C.
1323 If you use the software i2c interface (CONFIG_SOFT_I2C)
1324 then the following macros need to be defined (examples are
1325 from include/configs/lwmon.h):
1329 (Optional). Any commands necessary to enable the I2C
1330 controller or configure ports.
1332 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
1336 (Only for MPC8260 CPU). The I/O port to use (the code
1337 assumes both bits are on the same port). Valid values
1338 are 0..3 for ports A..D.
1342 The code necessary to make the I2C data line active
1343 (driven). If the data line is open collector, this
1346 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
1350 The code necessary to make the I2C data line tri-stated
1351 (inactive). If the data line is open collector, this
1354 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
1358 Code that returns TRUE if the I2C data line is high,
1361 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
1365 If <bit> is TRUE, sets the I2C data line high. If it
1366 is FALSE, it clears it (low).
1368 eg: #define I2C_SDA(bit) \
1369 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
1370 else immr->im_cpm.cp_pbdat &= ~PB_SDA
1374 If <bit> is TRUE, sets the I2C clock line high. If it
1375 is FALSE, it clears it (low).
1377 eg: #define I2C_SCL(bit) \
1378 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
1379 else immr->im_cpm.cp_pbdat &= ~PB_SCL
1383 This delay is invoked four times per clock cycle so this
1384 controls the rate of data transfer. The data rate thus
1385 is 1 / (I2C_DELAY * 4). Often defined to be something
1388 #define I2C_DELAY udelay(2)
1392 When a board is reset during an i2c bus transfer
1393 chips might think that the current transfer is still
1394 in progress. On some boards it is possible to access
1395 the i2c SCLK line directly, either by using the
1396 processor pin as a GPIO or by having a second pin
1397 connected to the bus. If this option is defined a
1398 custom i2c_init_board() routine in boards/xxx/board.c
1399 is run early in the boot sequence.
1401 CONFIG_I2CFAST (PPC405GP|PPC405EP only)
1403 This option enables configuration of bi_iic_fast[] flags
1404 in u-boot bd_info structure based on u-boot environment
1405 variable "i2cfast". (see also i2cfast)
1407 CONFIG_I2C_MULTI_BUS
1409 This option allows the use of multiple I2C buses, each of which
1410 must have a controller. At any point in time, only one bus is
1411 active. To switch to a different bus, use the 'i2c dev' command.
1412 Note that bus numbering is zero-based.
1416 This option specifies a list of I2C devices that will be skipped
1417 when the 'i2c probe' command is issued (or 'iprobe' using the legacy
1418 command). If CONFIG_I2C_MULTI_BUS is set, specify a list of bus-device
1419 pairs. Otherwise, specify a 1D array of device addresses
1422 #undef CONFIG_I2C_MULTI_BUS
1423 #define CFG_I2C_NOPROBES {0x50,0x68}
1425 will skip addresses 0x50 and 0x68 on a board with one I2C bus
1427 #define CONFIG_I2C_MULTI_BUS
1428 #define CFG_I2C_MULTI_NOPROBES {{0,0x50},{0,0x68},{1,0x54}}
1430 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1
1434 If defined, then this indicates the I2C bus number for DDR SPD.
1435 If not defined, then U-Boot assumes that SPD is on I2C bus 0.
1439 If defined, then this indicates the I2C bus number for the RTC.
1440 If not defined, then U-Boot assumes that RTC is on I2C bus 0.
1444 If defined, then this indicates the I2C bus number for the DTT.
1445 If not defined, then U-Boot assumes that DTT is on I2C bus 0.
1449 Define this option if you want to use Freescale's I2C driver in
1453 - SPI Support: CONFIG_SPI
1455 Enables SPI driver (so far only tested with
1456 SPI EEPROM, also an instance works with Crystal A/D and
1457 D/As on the SACSng board)
1461 Enables extended (16-bit) SPI EEPROM addressing.
1462 (symmetrical to CONFIG_I2C_X)
1466 Enables a software (bit-bang) SPI driver rather than
1467 using hardware support. This is a general purpose
1468 driver that only requires three general I/O port pins
1469 (two outputs, one input) to function. If this is
1470 defined, the board configuration must define several
1471 SPI configuration items (port pins to use, etc). For
1472 an example, see include/configs/sacsng.h.
1474 - FPGA Support: CONFIG_FPGA_COUNT
1476 Specify the number of FPGA devices to support.
1480 Used to specify the types of FPGA devices. For example,
1481 #define CONFIG_FPGA CFG_XILINX_VIRTEX2
1483 CFG_FPGA_PROG_FEEDBACK
1485 Enable printing of hash marks during FPGA configuration.
1489 Enable checks on FPGA configuration interface busy
1490 status by the configuration function. This option
1491 will require a board or device specific function to
1496 If defined, a function that provides delays in the FPGA
1497 configuration driver.
1499 CFG_FPGA_CHECK_CTRLC
1500 Allow Control-C to interrupt FPGA configuration
1502 CFG_FPGA_CHECK_ERROR
1504 Check for configuration errors during FPGA bitfile
1505 loading. For example, abort during Virtex II
1506 configuration if the INIT_B line goes low (which
1507 indicated a CRC error).
1511 Maximum time to wait for the INIT_B line to deassert
1512 after PROB_B has been deasserted during a Virtex II
1513 FPGA configuration sequence. The default time is 500
1518 Maximum time to wait for BUSY to deassert during
1519 Virtex II FPGA configuration. The default is 5 mS.
1521 CFG_FPGA_WAIT_CONFIG
1523 Time to wait after FPGA configuration. The default is
1526 - Configuration Management:
1529 If defined, this string will be added to the U-Boot
1530 version information (U_BOOT_VERSION)
1532 - Vendor Parameter Protection:
1534 U-Boot considers the values of the environment
1535 variables "serial#" (Board Serial Number) and
1536 "ethaddr" (Ethernet Address) to be parameters that
1537 are set once by the board vendor / manufacturer, and
1538 protects these variables from casual modification by
1539 the user. Once set, these variables are read-only,
1540 and write or delete attempts are rejected. You can
1541 change this behviour:
1543 If CONFIG_ENV_OVERWRITE is #defined in your config
1544 file, the write protection for vendor parameters is
1545 completely disabled. Anybody can change or delete
1548 Alternatively, if you #define _both_ CONFIG_ETHADDR
1549 _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
1550 ethernet address is installed in the environment,
1551 which can be changed exactly ONCE by the user. [The
1552 serial# is unaffected by this, i. e. it remains
1558 Define this variable to enable the reservation of
1559 "protected RAM", i. e. RAM which is not overwritten
1560 by U-Boot. Define CONFIG_PRAM to hold the number of
1561 kB you want to reserve for pRAM. You can overwrite
1562 this default value by defining an environment
1563 variable "pram" to the number of kB you want to
1564 reserve. Note that the board info structure will
1565 still show the full amount of RAM. If pRAM is
1566 reserved, a new environment variable "mem" will
1567 automatically be defined to hold the amount of
1568 remaining RAM in a form that can be passed as boot
1569 argument to Linux, for instance like that:
1571 setenv bootargs ... mem=\${mem}
1574 This way you can tell Linux not to use this memory,
1575 either, which results in a memory region that will
1576 not be affected by reboots.
1578 *WARNING* If your board configuration uses automatic
1579 detection of the RAM size, you must make sure that
1580 this memory test is non-destructive. So far, the
1581 following board configurations are known to be
1584 ETX094, IVMS8, IVML24, SPD8xx, TQM8xxL,
1585 HERMES, IP860, RPXlite, LWMON, LANTEC,
1586 PCU_E, FLAGADM, TQM8260
1591 Define this variable to stop the system in case of a
1592 fatal error, so that you have to reset it manually.
1593 This is probably NOT a good idea for an embedded
1594 system where you want to system to reboot
1595 automatically as fast as possible, but it may be
1596 useful during development since you can try to debug
1597 the conditions that lead to the situation.
1599 CONFIG_NET_RETRY_COUNT
1601 This variable defines the number of retries for
1602 network operations like ARP, RARP, TFTP, or BOOTP
1603 before giving up the operation. If not defined, a
1604 default value of 5 is used.
1606 - Command Interpreter:
1607 CONFIG_AUTO_COMPLETE
1609 Enable auto completion of commands using TAB.
1611 Note that this feature has NOT been implemented yet
1612 for the "hush" shell.
1617 Define this variable to enable the "hush" shell (from
1618 Busybox) as command line interpreter, thus enabling
1619 powerful command line syntax like
1620 if...then...else...fi conditionals or `&&' and '||'
1621 constructs ("shell scripts").
1623 If undefined, you get the old, much simpler behaviour
1624 with a somewhat smaller memory footprint.
1629 This defines the secondary prompt string, which is
1630 printed when the command interpreter needs more input
1631 to complete a command. Usually "> ".
1635 In the current implementation, the local variables
1636 space and global environment variables space are
1637 separated. Local variables are those you define by
1638 simply typing `name=value'. To access a local
1639 variable later on, you have write `$name' or
1640 `${name}'; to execute the contents of a variable
1641 directly type `$name' at the command prompt.
1643 Global environment variables are those you use
1644 setenv/printenv to work with. To run a command stored
1645 in such a variable, you need to use the run command,
1646 and you must not use the '$' sign to access them.
1648 To store commands and special characters in a
1649 variable, please use double quotation marks
1650 surrounding the whole text of the variable, instead
1651 of the backslashes before semicolons and special
1654 - Commandline Editing and History:
1655 CONFIG_CMDLINE_EDITING
1657 Enable editiong and History functions for interactive
1658 commandline input operations
1660 - Default Environment:
1661 CONFIG_EXTRA_ENV_SETTINGS
1663 Define this to contain any number of null terminated
1664 strings (variable = value pairs) that will be part of
1665 the default environment compiled into the boot image.
1667 For example, place something like this in your
1668 board's config file:
1670 #define CONFIG_EXTRA_ENV_SETTINGS \
1674 Warning: This method is based on knowledge about the
1675 internal format how the environment is stored by the
1676 U-Boot code. This is NOT an official, exported
1677 interface! Although it is unlikely that this format
1678 will change soon, there is no guarantee either.
1679 You better know what you are doing here.
1681 Note: overly (ab)use of the default environment is
1682 discouraged. Make sure to check other ways to preset
1683 the environment like the autoscript function or the
1686 - DataFlash Support:
1687 CONFIG_HAS_DATAFLASH
1689 Defining this option enables DataFlash features and
1690 allows to read/write in Dataflash via the standard
1693 - SystemACE Support:
1696 Adding this option adds support for Xilinx SystemACE
1697 chips attached via some sort of local bus. The address
1698 of the chip must alsh be defined in the
1699 CFG_SYSTEMACE_BASE macro. For example:
1701 #define CONFIG_SYSTEMACE
1702 #define CFG_SYSTEMACE_BASE 0xf0000000
1704 When SystemACE support is added, the "ace" device type
1705 becomes available to the fat commands, i.e. fatls.
1707 - TFTP Fixed UDP Port:
1710 If this is defined, the environment variable tftpsrcp
1711 is used to supply the TFTP UDP source port value.
1712 If tftpsrcp isn't defined, the normal pseudo-random port
1713 number generator is used.
1715 Also, the environment variable tftpdstp is used to supply
1716 the TFTP UDP destination port value. If tftpdstp isn't
1717 defined, the normal port 69 is used.
1719 The purpose for tftpsrcp is to allow a TFTP server to
1720 blindly start the TFTP transfer using the pre-configured
1721 target IP address and UDP port. This has the effect of
1722 "punching through" the (Windows XP) firewall, allowing
1723 the remainder of the TFTP transfer to proceed normally.
1724 A better solution is to properly configure the firewall,
1725 but sometimes that is not allowed.
1727 - Show boot progress:
1728 CONFIG_SHOW_BOOT_PROGRESS
1730 Defining this option allows to add some board-
1731 specific code (calling a user-provided function
1732 "show_boot_progress(int)") that enables you to show
1733 the system's boot progress on some display (for
1734 example, some LED's) on your board. At the moment,
1735 the following checkpoints are implemented:
1738 1 common/cmd_bootm.c before attempting to boot an image
1739 -1 common/cmd_bootm.c Image header has bad magic number
1740 2 common/cmd_bootm.c Image header has correct magic number
1741 -2 common/cmd_bootm.c Image header has bad checksum
1742 3 common/cmd_bootm.c Image header has correct checksum
1743 -3 common/cmd_bootm.c Image data has bad checksum
1744 4 common/cmd_bootm.c Image data has correct checksum
1745 -4 common/cmd_bootm.c Image is for unsupported architecture
1746 5 common/cmd_bootm.c Architecture check OK
1747 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi, standalone)
1748 6 common/cmd_bootm.c Image Type check OK
1749 -6 common/cmd_bootm.c gunzip uncompression error
1750 -7 common/cmd_bootm.c Unimplemented compression type
1751 7 common/cmd_bootm.c Uncompression OK
1752 -8 common/cmd_bootm.c Wrong Image Type (not kernel, multi, standalone)
1753 8 common/cmd_bootm.c Image Type check OK
1754 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX)
1755 9 common/cmd_bootm.c Start initial ramdisk verification
1756 -10 common/cmd_bootm.c Ramdisk header has bad magic number
1757 -11 common/cmd_bootm.c Ramdisk header has bad checksum
1758 10 common/cmd_bootm.c Ramdisk header is OK
1759 -12 common/cmd_bootm.c Ramdisk data has bad checksum
1760 11 common/cmd_bootm.c Ramdisk data has correct checksum
1761 12 common/cmd_bootm.c Ramdisk verification complete, start loading
1762 -13 common/cmd_bootm.c Wrong Image Type (not PPC Linux Ramdisk)
1763 13 common/cmd_bootm.c Start multifile image verification
1764 14 common/cmd_bootm.c No initial ramdisk, no multifile, continue.
1765 15 common/cmd_bootm.c All preparation done, transferring control to OS
1767 -30 lib_ppc/board.c Fatal error, hang the system
1768 -31 post/post.c POST test failed, detected by post_output_backlog()
1769 -32 post/post.c POST test failed, detected by post_run_single()
1771 34 common/cmd_doc.c before loading a Image from a DOC device
1772 -35 common/cmd_doc.c Bad usage of "doc" command
1773 35 common/cmd_doc.c correct usage of "doc" command
1774 -36 common/cmd_doc.c No boot device
1775 36 common/cmd_doc.c correct boot device
1776 -37 common/cmd_doc.c Unknown Chip ID on boot device
1777 37 common/cmd_doc.c correct chip ID found, device available
1778 -38 common/cmd_doc.c Read Error on boot device
1779 38 common/cmd_doc.c reading Image header from DOC device OK
1780 -39 common/cmd_doc.c Image header has bad magic number
1781 39 common/cmd_doc.c Image header has correct magic number
1782 -40 common/cmd_doc.c Error reading Image from DOC device
1783 40 common/cmd_doc.c Image header has correct magic number
1784 41 common/cmd_ide.c before loading a Image from a IDE device
1785 -42 common/cmd_ide.c Bad usage of "ide" command
1786 42 common/cmd_ide.c correct usage of "ide" command
1787 -43 common/cmd_ide.c No boot device
1788 43 common/cmd_ide.c boot device found
1789 -44 common/cmd_ide.c Device not available
1790 44 common/cmd_ide.c Device available
1791 -45 common/cmd_ide.c wrong partition selected
1792 45 common/cmd_ide.c partition selected
1793 -46 common/cmd_ide.c Unknown partition table
1794 46 common/cmd_ide.c valid partition table found
1795 -47 common/cmd_ide.c Invalid partition type
1796 47 common/cmd_ide.c correct partition type
1797 -48 common/cmd_ide.c Error reading Image Header on boot device
1798 48 common/cmd_ide.c reading Image Header from IDE device OK
1799 -49 common/cmd_ide.c Image header has bad magic number
1800 49 common/cmd_ide.c Image header has correct magic number
1801 -50 common/cmd_ide.c Image header has bad checksum
1802 50 common/cmd_ide.c Image header has correct checksum
1803 -51 common/cmd_ide.c Error reading Image from IDE device
1804 51 common/cmd_ide.c reading Image from IDE device OK
1805 52 common/cmd_nand.c before loading a Image from a NAND device
1806 -53 common/cmd_nand.c Bad usage of "nand" command
1807 53 common/cmd_nand.c correct usage of "nand" command
1808 -54 common/cmd_nand.c No boot device
1809 54 common/cmd_nand.c boot device found
1810 -55 common/cmd_nand.c Unknown Chip ID on boot device
1811 55 common/cmd_nand.c correct chip ID found, device available
1812 -56 common/cmd_nand.c Error reading Image Header on boot device
1813 56 common/cmd_nand.c reading Image Header from NAND device OK
1814 -57 common/cmd_nand.c Image header has bad magic number
1815 57 common/cmd_nand.c Image header has correct magic number
1816 -58 common/cmd_nand.c Error reading Image from NAND device
1817 58 common/cmd_nand.c reading Image from NAND device OK
1819 -60 common/env_common.c Environment has a bad CRC, using default
1821 64 net/eth.c starting with Ethernetconfiguration.
1822 -64 net/eth.c no Ethernet found.
1823 65 net/eth.c Ethernet found.
1825 -80 common/cmd_net.c usage wrong
1826 80 common/cmd_net.c before calling NetLoop()
1827 -81 common/cmd_net.c some error in NetLoop() occured
1828 81 common/cmd_net.c NetLoop() back without error
1829 -82 common/cmd_net.c size == 0 (File with size 0 loaded)
1830 82 common/cmd_net.c trying automatic boot
1831 83 common/cmd_net.c running autoscript
1832 -83 common/cmd_net.c some error in automatic boot or autoscript
1833 84 common/cmd_net.c end without errors
1838 [so far only for SMDK2400 and TRAB boards]
1840 - Modem support endable:
1841 CONFIG_MODEM_SUPPORT
1843 - RTS/CTS Flow control enable:
1846 - Modem debug support:
1847 CONFIG_MODEM_SUPPORT_DEBUG
1849 Enables debugging stuff (char screen[1024], dbg())
1850 for modem support. Useful only with BDI2000.
1852 - Interrupt support (PPC):
1854 There are common interrupt_init() and timer_interrupt()
1855 for all PPC archs. interrupt_init() calls interrupt_init_cpu()
1856 for cpu specific initialization. interrupt_init_cpu()
1857 should set decrementer_count to appropriate value. If
1858 cpu resets decrementer automatically after interrupt
1859 (ppc4xx) it should set decrementer_count to zero.
1860 timer_interrupt() calls timer_interrupt_cpu() for cpu
1861 specific handling. If board has watchdog / status_led
1862 / other_activity_monitor it works automatically from
1863 general timer_interrupt().
1867 In the target system modem support is enabled when a
1868 specific key (key combination) is pressed during
1869 power-on. Otherwise U-Boot will boot normally
1870 (autoboot). The key_pressed() fuction is called from
1871 board_init(). Currently key_pressed() is a dummy
1872 function, returning 1 and thus enabling modem
1875 If there are no modem init strings in the
1876 environment, U-Boot proceed to autoboot; the
1877 previous output (banner, info printfs) will be
1880 See also: doc/README.Modem
1883 Configuration Settings:
1884 -----------------------
1886 - CFG_LONGHELP: Defined when you want long help messages included;
1887 undefine this when you're short of memory.
1889 - CFG_PROMPT: This is what U-Boot prints on the console to
1890 prompt for user input.
1892 - CFG_CBSIZE: Buffer size for input from the Console
1894 - CFG_PBSIZE: Buffer size for Console output
1896 - CFG_MAXARGS: max. Number of arguments accepted for monitor commands
1898 - CFG_BARGSIZE: Buffer size for Boot Arguments which are passed to
1899 the application (usually a Linux kernel) when it is
1902 - CFG_BAUDRATE_TABLE:
1903 List of legal baudrate settings for this board.
1905 - CFG_CONSOLE_INFO_QUIET
1906 Suppress display of console information at boot.
1908 - CFG_CONSOLE_IS_IN_ENV
1909 If the board specific function
1910 extern int overwrite_console (void);
1911 returns 1, the stdin, stderr and stdout are switched to the
1912 serial port, else the settings in the environment are used.
1914 - CFG_CONSOLE_OVERWRITE_ROUTINE
1915 Enable the call to overwrite_console().
1917 - CFG_CONSOLE_ENV_OVERWRITE
1918 Enable overwrite of previous console environment settings.
1920 - CFG_MEMTEST_START, CFG_MEMTEST_END:
1921 Begin and End addresses of the area used by the
1925 Enable an alternate, more extensive memory test.
1927 - CFG_MEMTEST_SCRATCH:
1928 Scratch address used by the alternate memory test
1929 You only need to set this if address zero isn't writeable
1931 - CFG_TFTP_LOADADDR:
1932 Default load address for network file downloads
1934 - CFG_LOADS_BAUD_CHANGE:
1935 Enable temporary baudrate change while serial download
1938 Physical start address of SDRAM. _Must_ be 0 here.
1941 Physical start address of Motherboard I/O (if using a
1945 Physical start address of Flash memory.
1948 Physical start address of boot monitor code (set by
1949 make config files to be same as the text base address
1950 (TEXT_BASE) used when linking) - same as
1951 CFG_FLASH_BASE when booting from flash.
1954 Size of memory reserved for monitor code, used to
1955 determine _at_compile_time_ (!) if the environment is
1956 embedded within the U-Boot image, or in a separate
1960 Size of DRAM reserved for malloc() use.
1963 Normally compressed uImages are limited to an
1964 uncompressed size of 8 MBytes. If this is not enough,
1965 you can define CFG_BOOTM_LEN in your board config file
1966 to adjust this setting to your needs.
1969 Maximum size of memory mapped by the startup code of
1970 the Linux kernel; all data that must be processed by
1971 the Linux kernel (bd_info, boot arguments, eventually
1972 initrd image) must be put below this limit.
1974 - CFG_MAX_FLASH_BANKS:
1975 Max number of Flash memory banks
1977 - CFG_MAX_FLASH_SECT:
1978 Max number of sectors on a Flash chip
1980 - CFG_FLASH_ERASE_TOUT:
1981 Timeout for Flash erase operations (in ms)
1983 - CFG_FLASH_WRITE_TOUT:
1984 Timeout for Flash write operations (in ms)
1986 - CFG_FLASH_LOCK_TOUT
1987 Timeout for Flash set sector lock bit operation (in ms)
1989 - CFG_FLASH_UNLOCK_TOUT
1990 Timeout for Flash clear lock bits operation (in ms)
1992 - CFG_FLASH_PROTECTION
1993 If defined, hardware flash sectors protection is used
1994 instead of U-Boot software protection.
1996 - CFG_DIRECT_FLASH_TFTP:
1998 Enable TFTP transfers directly to flash memory;
1999 without this option such a download has to be
2000 performed in two steps: (1) download to RAM, and (2)
2001 copy from RAM to flash.
2003 The two-step approach is usually more reliable, since
2004 you can check if the download worked before you erase
2005 the flash, but in some situations (when sytem RAM is
2006 too limited to allow for a tempory copy of the
2007 downloaded image) this option may be very useful.
2010 Define if the flash driver uses extra elements in the
2011 common flash structure for storing flash geometry.
2013 - CFG_FLASH_CFI_DRIVER
2014 This option also enables the building of the cfi_flash driver
2015 in the drivers directory
2017 - CFG_FLASH_QUIET_TEST
2018 If this option is defined, the common CFI flash doesn't
2019 print it's warning upon not recognized FLASH banks. This
2020 is useful, if some of the configured banks are only
2021 optionally available.
2023 - CFG_RX_ETH_BUFFER:
2024 Defines the number of ethernet receive buffers. On some
2025 ethernet controllers it is recommended to set this value
2026 to 8 or even higher (EEPRO100 or 405 EMAC), since all
2027 buffers can be full shortly after enabling the interface
2028 on high ethernet traffic.
2029 Defaults to 4 if not defined.
2031 The following definitions that deal with the placement and management
2032 of environment data (variable area); in general, we support the
2033 following configurations:
2035 - CFG_ENV_IS_IN_FLASH:
2037 Define this if the environment is in flash memory.
2039 a) The environment occupies one whole flash sector, which is
2040 "embedded" in the text segment with the U-Boot code. This
2041 happens usually with "bottom boot sector" or "top boot
2042 sector" type flash chips, which have several smaller
2043 sectors at the start or the end. For instance, such a
2044 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In
2045 such a case you would place the environment in one of the
2046 4 kB sectors - with U-Boot code before and after it. With
2047 "top boot sector" type flash chips, you would put the
2048 environment in one of the last sectors, leaving a gap
2049 between U-Boot and the environment.
2053 Offset of environment data (variable area) to the
2054 beginning of flash memory; for instance, with bottom boot
2055 type flash chips the second sector can be used: the offset
2056 for this sector is given here.
2058 CFG_ENV_OFFSET is used relative to CFG_FLASH_BASE.
2062 This is just another way to specify the start address of
2063 the flash sector containing the environment (instead of
2066 - CFG_ENV_SECT_SIZE:
2068 Size of the sector containing the environment.
2071 b) Sometimes flash chips have few, equal sized, BIG sectors.
2072 In such a case you don't want to spend a whole sector for
2077 If you use this in combination with CFG_ENV_IS_IN_FLASH
2078 and CFG_ENV_SECT_SIZE, you can specify to use only a part
2079 of this flash sector for the environment. This saves
2080 memory for the RAM copy of the environment.
2082 It may also save flash memory if you decide to use this
2083 when your environment is "embedded" within U-Boot code,
2084 since then the remainder of the flash sector could be used
2085 for U-Boot code. It should be pointed out that this is
2086 STRONGLY DISCOURAGED from a robustness point of view:
2087 updating the environment in flash makes it always
2088 necessary to erase the WHOLE sector. If something goes
2089 wrong before the contents has been restored from a copy in
2090 RAM, your target system will be dead.
2092 - CFG_ENV_ADDR_REDUND
2095 These settings describe a second storage area used to hold
2096 a redundand copy of the environment data, so that there is
2097 a valid backup copy in case there is a power failure during
2098 a "saveenv" operation.
2100 BE CAREFUL! Any changes to the flash layout, and some changes to the
2101 source code will make it necessary to adapt <board>/u-boot.lds*
2105 - CFG_ENV_IS_IN_NVRAM:
2107 Define this if you have some non-volatile memory device
2108 (NVRAM, battery buffered SRAM) which you want to use for the
2114 These two #defines are used to determin the memory area you
2115 want to use for environment. It is assumed that this memory
2116 can just be read and written to, without any special
2119 BE CAREFUL! The first access to the environment happens quite early
2120 in U-Boot initalization (when we try to get the setting of for the
2121 console baudrate). You *MUST* have mappend your NVRAM area then, or
2124 Please note that even with NVRAM we still use a copy of the
2125 environment in RAM: we could work on NVRAM directly, but we want to
2126 keep settings there always unmodified except somebody uses "saveenv"
2127 to save the current settings.
2130 - CFG_ENV_IS_IN_EEPROM:
2132 Use this if you have an EEPROM or similar serial access
2133 device and a driver for it.
2138 These two #defines specify the offset and size of the
2139 environment area within the total memory of your EEPROM.
2141 - CFG_I2C_EEPROM_ADDR:
2142 If defined, specified the chip address of the EEPROM device.
2143 The default address is zero.
2145 - CFG_EEPROM_PAGE_WRITE_BITS:
2146 If defined, the number of bits used to address bytes in a
2147 single page in the EEPROM device. A 64 byte page, for example
2148 would require six bits.
2150 - CFG_EEPROM_PAGE_WRITE_DELAY_MS:
2151 If defined, the number of milliseconds to delay between
2152 page writes. The default is zero milliseconds.
2154 - CFG_I2C_EEPROM_ADDR_LEN:
2155 The length in bytes of the EEPROM memory array address. Note
2156 that this is NOT the chip address length!
2158 - CFG_I2C_EEPROM_ADDR_OVERFLOW:
2159 EEPROM chips that implement "address overflow" are ones
2160 like Catalyst 24WC04/08/16 which has 9/10/11 bits of
2161 address and the extra bits end up in the "chip address" bit
2162 slots. This makes a 24WC08 (1Kbyte) chip look like four 256
2165 Note that we consider the length of the address field to
2166 still be one byte because the extra address bits are hidden
2167 in the chip address.
2170 The size in bytes of the EEPROM device.
2173 - CFG_ENV_IS_IN_DATAFLASH:
2175 Define this if you have a DataFlash memory device which you
2176 want to use for the environment.
2182 These three #defines specify the offset and size of the
2183 environment area within the total memory of your DataFlash placed
2184 at the specified address.
2186 - CFG_ENV_IS_IN_NAND:
2188 Define this if you have a NAND device which you want to use
2189 for the environment.
2194 These two #defines specify the offset and size of the environment
2195 area within the first NAND device.
2197 - CFG_ENV_OFFSET_REDUND
2199 This setting describes a second storage area of CFG_ENV_SIZE
2200 size used to hold a redundant copy of the environment data,
2201 so that there is a valid backup copy in case there is a
2202 power failure during a "saveenv" operation.
2204 Note: CFG_ENV_OFFSET and CFG_ENV_OFFSET_REDUND must be aligned
2205 to a block boundary, and CFG_ENV_SIZE must be a multiple of
2206 the NAND devices block size.
2208 - CFG_SPI_INIT_OFFSET
2210 Defines offset to the initial SPI buffer area in DPRAM. The
2211 area is used at an early stage (ROM part) if the environment
2212 is configured to reside in the SPI EEPROM: We need a 520 byte
2213 scratch DPRAM area. It is used between the two initialization
2214 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems
2215 to be a good choice since it makes it far enough from the
2216 start of the data area as well as from the stack pointer.
2218 Please note that the environment is read-only as long as the monitor
2219 has been relocated to RAM and a RAM copy of the environment has been
2220 created; also, when using EEPROM you will have to use getenv_r()
2221 until then to read environment variables.
2223 The environment is protected by a CRC32 checksum. Before the monitor
2224 is relocated into RAM, as a result of a bad CRC you will be working
2225 with the compiled-in default environment - *silently*!!! [This is
2226 necessary, because the first environment variable we need is the
2227 "baudrate" setting for the console - if we have a bad CRC, we don't
2228 have any device yet where we could complain.]
2230 Note: once the monitor has been relocated, then it will complain if
2231 the default environment is used; a new CRC is computed as soon as you
2232 use the "saveenv" command to store a valid environment.
2234 - CFG_FAULT_ECHO_LINK_DOWN:
2235 Echo the inverted Ethernet link state to the fault LED.
2237 Note: If this option is active, then CFG_FAULT_MII_ADDR
2238 also needs to be defined.
2240 - CFG_FAULT_MII_ADDR:
2241 MII address of the PHY to check for the Ethernet link state.
2243 - CFG_64BIT_VSPRINTF:
2244 Makes vsprintf (and all *printf functions) support printing
2245 of 64bit values by using the L quantifier
2247 - CFG_64BIT_STRTOUL:
2248 Adds simple_strtoull that returns a 64bit value
2250 Low Level (hardware related) configuration options:
2251 ---------------------------------------------------
2253 - CFG_CACHELINE_SIZE:
2254 Cache Line Size of the CPU.
2257 Default address of the IMMR after system reset.
2259 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU,
2260 and RPXsuper) to be able to adjust the position of
2261 the IMMR register after a reset.
2263 - Floppy Disk Support:
2264 CFG_FDC_DRIVE_NUMBER
2266 the default drive number (default value 0)
2270 defines the spacing between fdc chipset registers
2275 defines the offset of register from address. It
2276 depends on which part of the data bus is connected to
2277 the fdc chipset. (default value 0)
2279 If CFG_ISA_IO_STRIDE CFG_ISA_IO_OFFSET and
2280 CFG_FDC_DRIVE_NUMBER are undefined, they take their
2283 if CFG_FDC_HW_INIT is defined, then the function
2284 fdc_hw_init() is called at the beginning of the FDC
2285 setup. fdc_hw_init() must be provided by the board
2286 source code. It is used to make hardware dependant
2289 - CFG_IMMR: Physical address of the Internal Memory.
2290 DO NOT CHANGE unless you know exactly what you're
2291 doing! (11-4) [MPC8xx/82xx systems only]
2293 - CFG_INIT_RAM_ADDR:
2295 Start address of memory area that can be used for
2296 initial data and stack; please note that this must be
2297 writable memory that is working WITHOUT special
2298 initialization, i. e. you CANNOT use normal RAM which
2299 will become available only after programming the
2300 memory controller and running certain initialization
2303 U-Boot uses the following memory types:
2304 - MPC8xx and MPC8260: IMMR (internal memory of the CPU)
2305 - MPC824X: data cache
2306 - PPC4xx: data cache
2308 - CFG_GBL_DATA_OFFSET:
2310 Offset of the initial data structure in the memory
2311 area defined by CFG_INIT_RAM_ADDR. Usually
2312 CFG_GBL_DATA_OFFSET is chosen such that the initial
2313 data is located at the end of the available space
2314 (sometimes written as (CFG_INIT_RAM_END -
2315 CFG_INIT_DATA_SIZE), and the initial stack is just
2316 below that area (growing from (CFG_INIT_RAM_ADDR +
2317 CFG_GBL_DATA_OFFSET) downward.
2320 On the MPC824X (or other systems that use the data
2321 cache for initial memory) the address chosen for
2322 CFG_INIT_RAM_ADDR is basically arbitrary - it must
2323 point to an otherwise UNUSED address space between
2324 the top of RAM and the start of the PCI space.
2326 - CFG_SIUMCR: SIU Module Configuration (11-6)
2328 - CFG_SYPCR: System Protection Control (11-9)
2330 - CFG_TBSCR: Time Base Status and Control (11-26)
2332 - CFG_PISCR: Periodic Interrupt Status and Control (11-31)
2334 - CFG_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30)
2336 - CFG_SCCR: System Clock and reset Control Register (15-27)
2338 - CFG_OR_TIMING_SDRAM:
2342 periodic timer for refresh
2344 - CFG_DER: Debug Event Register (37-47)
2346 - FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CFG_REMAP_OR_AM,
2347 CFG_PRELIM_OR_AM, CFG_OR_TIMING_FLASH, CFG_OR0_REMAP,
2348 CFG_OR0_PRELIM, CFG_BR0_PRELIM, CFG_OR1_REMAP, CFG_OR1_PRELIM,
2350 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
2352 - SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
2353 CFG_OR_TIMING_SDRAM, CFG_OR2_PRELIM, CFG_BR2_PRELIM,
2354 CFG_OR3_PRELIM, CFG_BR3_PRELIM:
2355 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
2357 - CFG_MAMR_PTA, CFG_MPTPR_2BK_4K, CFG_MPTPR_1BK_4K, CFG_MPTPR_2BK_8K,
2358 CFG_MPTPR_1BK_8K, CFG_MAMR_8COL, CFG_MAMR_9COL:
2359 Machine Mode Register and Memory Periodic Timer
2360 Prescaler definitions (SDRAM timing)
2362 - CFG_I2C_UCODE_PATCH, CFG_I2C_DPMEM_OFFSET [0x1FC0]:
2363 enable I2C microcode relocation patch (MPC8xx);
2364 define relocation offset in DPRAM [DSP2]
2366 - CFG_SPI_UCODE_PATCH, CFG_SPI_DPMEM_OFFSET [0x1FC0]:
2367 enable SPI microcode relocation patch (MPC8xx);
2368 define relocation offset in DPRAM [SCC4]
2371 Use OSCM clock mode on MBX8xx board. Be careful,
2372 wrong setting might damage your board. Read
2373 doc/README.MBX before setting this variable!
2375 - CFG_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only)
2376 Offset of the bootmode word in DPRAM used by post
2377 (Power On Self Tests). This definition overrides
2378 #define'd default value in commproc.h resp.
2381 - CFG_PCI_SLV_MEM_LOCAL, CFG_PCI_SLV_MEM_BUS, CFG_PICMR0_MASK_ATTRIB,
2382 CFG_PCI_MSTR0_LOCAL, CFG_PCIMSK0_MASK, CFG_PCI_MSTR1_LOCAL,
2383 CFG_PCIMSK1_MASK, CFG_PCI_MSTR_MEM_LOCAL, CFG_PCI_MSTR_MEM_BUS,
2384 CFG_CPU_PCI_MEM_START, CFG_PCI_MSTR_MEM_SIZE, CFG_POCMR0_MASK_ATTRIB,
2385 CFG_PCI_MSTR_MEMIO_LOCAL, CFG_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START,
2386 CFG_PCI_MSTR_MEMIO_SIZE, CFG_POCMR1_MASK_ATTRIB, CFG_PCI_MSTR_IO_LOCAL,
2387 CFG_PCI_MSTR_IO_BUS, CFG_CPU_PCI_IO_START, CFG_PCI_MSTR_IO_SIZE,
2388 CFG_POCMR2_MASK_ATTRIB: (MPC826x only)
2389 Overrides the default PCI memory map in cpu/mpc8260/pci.c if set.
2392 Get DDR timing information from an I2C EEPROM. Common with pluggable
2393 memory modules such as SODIMMs
2395 I2C address of the SPD EEPROM
2398 If SPD EEPROM is on an I2C bus other than the first one, specify here.
2399 Note that the value must resolve to something your driver can deal with.
2401 - CFG_83XX_DDR_USES_CS0
2402 Only for 83xx systems. If specified, then DDR should be configured
2403 using CS0 and CS1 instead of CS2 and CS3.
2405 - CFG_83XX_DDR_USES_CS0
2406 Only for 83xx systems. If specified, then DDR should be configured
2407 using CS0 and CS1 instead of CS2 and CS3.
2409 - CONFIG_ETHER_ON_FEC[12]
2410 Define to enable FEC[12] on a 8xx series processor.
2412 - CONFIG_FEC[12]_PHY
2413 Define to the hardcoded PHY address which corresponds
2414 to the given FEC; i. e.
2415 #define CONFIG_FEC1_PHY 4
2416 means that the PHY with address 4 is connected to FEC1
2418 When set to -1, means to probe for first available.
2420 - CONFIG_FEC[12]_PHY_NORXERR
2421 The PHY does not have a RXERR line (RMII only).
2422 (so program the FEC to ignore it).
2425 Enable RMII mode for all FECs.
2426 Note that this is a global option, we can't
2427 have one FEC in standard MII mode and another in RMII mode.
2429 - CONFIG_CRC32_VERIFY
2430 Add a verify option to the crc32 command.
2433 => crc32 -v <address> <count> <crc32>
2435 Where address/count indicate a memory area
2436 and crc32 is the correct crc32 which the
2440 Add the "loopw" memory command. This only takes effect if
2441 the memory commands are activated globally (CONFIG_CMD_MEM).
2444 Add the "mdc" and "mwc" memory commands. These are cyclic
2449 This command will print 4 bytes (10,11,12,13) each 500 ms.
2451 => mwc.l 100 12345678 10
2452 This command will write 12345678 to address 100 all 10 ms.
2454 This only takes effect if the memory commands are activated
2455 globally (CONFIG_CMD_MEM).
2457 - CONFIG_SKIP_LOWLEVEL_INIT
2458 - CONFIG_SKIP_RELOCATE_UBOOT
2460 [ARM only] If these variables are defined, then
2461 certain low level initializations (like setting up
2462 the memory controller) are omitted and/or U-Boot does
2463 not relocate itself into RAM.
2464 Normally these variables MUST NOT be defined. The
2465 only exception is when U-Boot is loaded (to RAM) by
2466 some other boot loader or by a debugger which
2467 performs these intializations itself.
2470 Building the Software:
2471 ======================
2473 Building U-Boot has been tested in native PPC environments (on a
2474 PowerBook G3 running LinuxPPC 2000) and in cross environments
2475 (running RedHat 6.x and 7.x Linux on x86, Solaris 2.6 on a SPARC, and
2478 If you are not using a native PPC environment, it is assumed that you
2479 have the GNU cross compiling tools available in your path and named
2480 with a prefix of "powerpc-linux-". If this is not the case, (e.g. if
2481 you are using Monta Vista's Hard Hat Linux CDK 1.2) you must change
2482 the definition of CROSS_COMPILE in Makefile. For HHL on a 4xx CPU,
2485 CROSS_COMPILE = ppc_4xx-
2488 U-Boot is intended to be simple to build. After installing the
2489 sources you must configure U-Boot for one specific board type. This
2494 where "NAME_config" is the name of one of the existing
2495 configurations; the following names are supported:
2497 ADCIOP_config FPS860L_config omap730p2_config
2498 ADS860_config GEN860T_config pcu_e_config
2500 AR405_config GENIETV_config PIP405_config
2501 at91rm9200dk_config GTH_config QS823_config
2502 CANBT_config hermes_config QS850_config
2503 cmi_mpc5xx_config hymod_config QS860T_config
2504 cogent_common_config IP860_config RPXlite_config
2505 cogent_mpc8260_config IVML24_config RPXlite_DW_config
2506 cogent_mpc8xx_config IVMS8_config RPXsuper_config
2507 CPCI405_config JSE_config rsdproto_config
2508 CPCIISER4_config LANTEC_config Sandpoint8240_config
2509 csb272_config lwmon_config sbc8260_config
2510 CU824_config MBX860T_config sbc8560_33_config
2511 DUET_ADS_config MBX_config sbc8560_66_config
2512 EBONY_config mpc7448hpc2_config SM850_config
2513 ELPT860_config MPC8260ADS_config SPD823TS_config
2514 ESTEEM192E_config MPC8540ADS_config stxgp3_config
2515 ETX094_config MPC8540EVAL_config SXNI855T_config
2516 FADS823_config NMPC8560ADS_config TQM823L_config
2517 FADS850SAR_config NETVIA_config TQM850L_config
2518 FADS860T_config omap1510inn_config TQM855L_config
2519 FPS850L_config omap1610h2_config TQM860L_config
2520 omap1610inn_config walnut_config
2521 omap5912osk_config Yukon8220_config
2522 omap2420h4_config ZPC1900_config
2524 Note: for some board special configuration names may exist; check if
2525 additional information is available from the board vendor; for
2526 instance, the TQM823L systems are available without (standard)
2527 or with LCD support. You can select such additional "features"
2528 when chosing the configuration, i. e.
2531 - will configure for a plain TQM823L, i. e. no LCD support
2533 make TQM823L_LCD_config
2534 - will configure for a TQM823L with U-Boot console on LCD
2539 Finally, type "make all", and you should get some working U-Boot
2540 images ready for download to / installation on your system:
2542 - "u-boot.bin" is a raw binary image
2543 - "u-boot" is an image in ELF binary format
2544 - "u-boot.srec" is in Motorola S-Record format
2546 By default the build is performed locally and the objects are saved
2547 in the source directory. One of the two methods can be used to change
2548 this behavior and build U-Boot to some external directory:
2550 1. Add O= to the make command line invocations:
2552 make O=/tmp/build distclean
2553 make O=/tmp/build NAME_config
2554 make O=/tmp/build all
2556 2. Set environment variable BUILD_DIR to point to the desired location:
2558 export BUILD_DIR=/tmp/build
2563 Note that the command line "O=" setting overrides the BUILD_DIR environment
2567 Please be aware that the Makefiles assume you are using GNU make, so
2568 for instance on NetBSD you might need to use "gmake" instead of
2572 If the system board that you have is not listed, then you will need
2573 to port U-Boot to your hardware platform. To do this, follow these
2576 1. Add a new configuration option for your board to the toplevel
2577 "Makefile" and to the "MAKEALL" script, using the existing
2578 entries as examples. Note that here and at many other places
2579 boards and other names are listed in alphabetical sort order. Please
2581 2. Create a new directory to hold your board specific code. Add any
2582 files you need. In your board directory, you will need at least
2583 the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds".
2584 3. Create a new configuration file "include/configs/<board>.h" for
2586 3. If you're porting U-Boot to a new CPU, then also create a new
2587 directory to hold your CPU specific code. Add any files you need.
2588 4. Run "make <board>_config" with your new name.
2589 5. Type "make", and you should get a working "u-boot.srec" file
2590 to be installed on your target system.
2591 6. Debug and solve any problems that might arise.
2592 [Of course, this last step is much harder than it sounds.]
2595 Testing of U-Boot Modifications, Ports to New Hardware, etc.:
2596 ==============================================================
2598 If you have modified U-Boot sources (for instance added a new board
2599 or support for new devices, a new CPU, etc.) you are expected to
2600 provide feedback to the other developers. The feedback normally takes
2601 the form of a "patch", i. e. a context diff against a certain (latest
2602 official or latest in CVS) version of U-Boot sources.
2604 But before you submit such a patch, please verify that your modifi-
2605 cation did not break existing code. At least make sure that *ALL* of
2606 the supported boards compile WITHOUT ANY compiler warnings. To do so,
2607 just run the "MAKEALL" script, which will configure and build U-Boot
2608 for ALL supported system. Be warned, this will take a while. You can
2609 select which (cross) compiler to use by passing a `CROSS_COMPILE'
2610 environment variable to the script, i. e. to use the cross tools from
2611 MontaVista's Hard Hat Linux you can type
2613 CROSS_COMPILE=ppc_8xx- MAKEALL
2615 or to build on a native PowerPC system you can type
2617 CROSS_COMPILE=' ' MAKEALL
2619 When using the MAKEALL script, the default behaviour is to build U-Boot
2620 in the source directory. This location can be changed by setting the
2621 BUILD_DIR environment variable. Also, for each target built, the MAKEALL
2622 script saves two log files (<target>.ERR and <target>.MAKEALL) in the
2623 <source dir>/LOG directory. This default location can be changed by
2624 setting the MAKEALL_LOGDIR environment variable. For example:
2626 export BUILD_DIR=/tmp/build
2627 export MAKEALL_LOGDIR=/tmp/log
2628 CROSS_COMPILE=ppc_8xx- MAKEALL
2630 With the above settings build objects are saved in the /tmp/build, log
2631 files are saved in the /tmp/log and the source tree remains clean during
2632 the whole build process.
2635 See also "U-Boot Porting Guide" below.
2638 Monitor Commands - Overview:
2639 ============================
2641 go - start application at address 'addr'
2642 run - run commands in an environment variable
2643 bootm - boot application image from memory
2644 bootp - boot image via network using BootP/TFTP protocol
2645 tftpboot- boot image via network using TFTP protocol
2646 and env variables "ipaddr" and "serverip"
2647 (and eventually "gatewayip")
2648 rarpboot- boot image via network using RARP/TFTP protocol
2649 diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
2650 loads - load S-Record file over serial line
2651 loadb - load binary file over serial line (kermit mode)
2653 mm - memory modify (auto-incrementing)
2654 nm - memory modify (constant address)
2655 mw - memory write (fill)
2657 cmp - memory compare
2658 crc32 - checksum calculation
2659 imd - i2c memory display
2660 imm - i2c memory modify (auto-incrementing)
2661 inm - i2c memory modify (constant address)
2662 imw - i2c memory write (fill)
2663 icrc32 - i2c checksum calculation
2664 iprobe - probe to discover valid I2C chip addresses
2665 iloop - infinite loop on address range
2666 isdram - print SDRAM configuration information
2667 sspi - SPI utility commands
2668 base - print or set address offset
2669 printenv- print environment variables
2670 setenv - set environment variables
2671 saveenv - save environment variables to persistent storage
2672 protect - enable or disable FLASH write protection
2673 erase - erase FLASH memory
2674 flinfo - print FLASH memory information
2675 bdinfo - print Board Info structure
2676 iminfo - print header information for application image
2677 coninfo - print console devices and informations
2678 ide - IDE sub-system
2679 loop - infinite loop on address range
2680 loopw - infinite write loop on address range
2681 mtest - simple RAM test
2682 icache - enable or disable instruction cache
2683 dcache - enable or disable data cache
2684 reset - Perform RESET of the CPU
2685 echo - echo args to console
2686 version - print monitor version
2687 help - print online help
2688 ? - alias for 'help'
2691 Monitor Commands - Detailed Description:
2692 ========================================
2696 For now: just type "help <command>".
2699 Environment Variables:
2700 ======================
2702 U-Boot supports user configuration using Environment Variables which
2703 can be made persistent by saving to Flash memory.
2705 Environment Variables are set using "setenv", printed using
2706 "printenv", and saved to Flash using "saveenv". Using "setenv"
2707 without a value can be used to delete a variable from the
2708 environment. As long as you don't save the environment you are
2709 working with an in-memory copy. In case the Flash area containing the
2710 environment is erased by accident, a default environment is provided.
2712 Some configuration options can be set using Environment Variables:
2714 baudrate - see CONFIG_BAUDRATE
2716 bootdelay - see CONFIG_BOOTDELAY
2718 bootcmd - see CONFIG_BOOTCOMMAND
2720 bootargs - Boot arguments when booting an RTOS image
2722 bootfile - Name of the image to load with TFTP
2724 autoload - if set to "no" (any string beginning with 'n'),
2725 "bootp" will just load perform a lookup of the
2726 configuration from the BOOTP server, but not try to
2727 load any image using TFTP
2729 autostart - if set to "yes", an image loaded using the "bootp",
2730 "rarpboot", "tftpboot" or "diskboot" commands will
2731 be automatically started (by internally calling
2734 If set to "no", a standalone image passed to the
2735 "bootm" command will be copied to the load address
2736 (and eventually uncompressed), but NOT be started.
2737 This can be used to load and uncompress arbitrary
2740 i2cfast - (PPC405GP|PPC405EP only)
2741 if set to 'y' configures Linux I2C driver for fast
2742 mode (400kHZ). This environment variable is used in
2743 initialization code. So, for changes to be effective
2744 it must be saved and board must be reset.
2746 initrd_high - restrict positioning of initrd images:
2747 If this variable is not set, initrd images will be
2748 copied to the highest possible address in RAM; this
2749 is usually what you want since it allows for
2750 maximum initrd size. If for some reason you want to
2751 make sure that the initrd image is loaded below the
2752 CFG_BOOTMAPSZ limit, you can set this environment
2753 variable to a value of "no" or "off" or "0".
2754 Alternatively, you can set it to a maximum upper
2755 address to use (U-Boot will still check that it
2756 does not overwrite the U-Boot stack and data).
2758 For instance, when you have a system with 16 MB
2759 RAM, and want to reserve 4 MB from use by Linux,
2760 you can do this by adding "mem=12M" to the value of
2761 the "bootargs" variable. However, now you must make
2762 sure that the initrd image is placed in the first
2763 12 MB as well - this can be done with
2765 setenv initrd_high 00c00000
2767 If you set initrd_high to 0xFFFFFFFF, this is an
2768 indication to U-Boot that all addresses are legal
2769 for the Linux kernel, including addresses in flash
2770 memory. In this case U-Boot will NOT COPY the
2771 ramdisk at all. This may be useful to reduce the
2772 boot time on your system, but requires that this
2773 feature is supported by your Linux kernel.
2775 ipaddr - IP address; needed for tftpboot command
2777 loadaddr - Default load address for commands like "bootp",
2778 "rarpboot", "tftpboot", "loadb" or "diskboot"
2780 loads_echo - see CONFIG_LOADS_ECHO
2782 serverip - TFTP server IP address; needed for tftpboot command
2784 bootretry - see CONFIG_BOOT_RETRY_TIME
2786 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
2788 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
2790 ethprime - When CONFIG_NET_MULTI is enabled controls which
2791 interface is used first.
2793 ethact - When CONFIG_NET_MULTI is enabled controls which
2794 interface is currently active. For example you
2795 can do the following
2797 => setenv ethact FEC ETHERNET
2798 => ping 192.168.0.1 # traffic sent on FEC ETHERNET
2799 => setenv ethact SCC ETHERNET
2800 => ping 10.0.0.1 # traffic sent on SCC ETHERNET
2802 netretry - When set to "no" each network operation will
2803 either succeed or fail without retrying.
2804 When set to "once" the network operation will
2805 fail when all the available network interfaces
2806 are tried once without success.
2807 Useful on scripts which control the retry operation
2810 tftpsrcport - If this is set, the value is used for TFTP's
2813 tftpdstport - If this is set, the value is used for TFTP's UDP
2814 destination port instead of the Well Know Port 69.
2816 vlan - When set to a value < 4095 the traffic over
2817 ethernet is encapsulated/received over 802.1q
2820 The following environment variables may be used and automatically
2821 updated by the network boot commands ("bootp" and "rarpboot"),
2822 depending the information provided by your boot server:
2824 bootfile - see above
2825 dnsip - IP address of your Domain Name Server
2826 dnsip2 - IP address of your secondary Domain Name Server
2827 gatewayip - IP address of the Gateway (Router) to use
2828 hostname - Target hostname
2830 netmask - Subnet Mask
2831 rootpath - Pathname of the root filesystem on the NFS server
2832 serverip - see above
2835 There are two special Environment Variables:
2837 serial# - contains hardware identification information such
2838 as type string and/or serial number
2839 ethaddr - Ethernet address
2841 These variables can be set only once (usually during manufacturing of
2842 the board). U-Boot refuses to delete or overwrite these variables
2843 once they have been set once.
2846 Further special Environment Variables:
2848 ver - Contains the U-Boot version string as printed
2849 with the "version" command. This variable is
2850 readonly (see CONFIG_VERSION_VARIABLE).
2853 Please note that changes to some configuration parameters may take
2854 only effect after the next boot (yes, that's just like Windoze :-).
2857 Command Line Parsing:
2858 =====================
2860 There are two different command line parsers available with U-Boot:
2861 the old "simple" one, and the much more powerful "hush" shell:
2863 Old, simple command line parser:
2864 --------------------------------
2866 - supports environment variables (through setenv / saveenv commands)
2867 - several commands on one line, separated by ';'
2868 - variable substitution using "... ${name} ..." syntax
2869 - special characters ('$', ';') can be escaped by prefixing with '\',
2871 setenv bootcmd bootm \${address}
2872 - You can also escape text by enclosing in single apostrophes, for example:
2873 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
2878 - similar to Bourne shell, with control structures like
2879 if...then...else...fi, for...do...done; while...do...done,
2880 until...do...done, ...
2881 - supports environment ("global") variables (through setenv / saveenv
2882 commands) and local shell variables (through standard shell syntax
2883 "name=value"); only environment variables can be used with "run"
2889 (1) If a command line (or an environment variable executed by a "run"
2890 command) contains several commands separated by semicolon, and
2891 one of these commands fails, then the remaining commands will be
2894 (2) If you execute several variables with one call to run (i. e.
2895 calling run with a list af variables as arguments), any failing
2896 command will cause "run" to terminate, i. e. the remaining
2897 variables are not executed.
2899 Note for Redundant Ethernet Interfaces:
2900 =======================================
2902 Some boards come with redundant ethernet interfaces; U-Boot supports
2903 such configurations and is capable of automatic selection of a
2904 "working" interface when needed. MAC assignment works as follows:
2906 Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
2907 MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
2908 "eth1addr" (=>eth1), "eth2addr", ...
2910 If the network interface stores some valid MAC address (for instance
2911 in SROM), this is used as default address if there is NO correspon-
2912 ding setting in the environment; if the corresponding environment
2913 variable is set, this overrides the settings in the card; that means:
2915 o If the SROM has a valid MAC address, and there is no address in the
2916 environment, the SROM's address is used.
2918 o If there is no valid address in the SROM, and a definition in the
2919 environment exists, then the value from the environment variable is
2922 o If both the SROM and the environment contain a MAC address, and
2923 both addresses are the same, this MAC address is used.
2925 o If both the SROM and the environment contain a MAC address, and the
2926 addresses differ, the value from the environment is used and a
2929 o If neither SROM nor the environment contain a MAC address, an error
2936 The "boot" commands of this monitor operate on "image" files which
2937 can be basicly anything, preceeded by a special header; see the
2938 definitions in include/image.h for details; basicly, the header
2939 defines the following image properties:
2941 * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
2942 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
2943 LynxOS, pSOS, QNX, RTEMS, ARTOS;
2944 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, ARTOS, LynxOS).
2945 * Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86,
2946 IA64, MIPS, NIOS, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
2947 Currently supported: ARM, AVR32, Intel x86, MIPS, NIOS, PowerPC).
2948 * Compression Type (uncompressed, gzip, bzip2)
2954 The header is marked by a special Magic Number, and both the header
2955 and the data portions of the image are secured against corruption by
2962 Although U-Boot should support any OS or standalone application
2963 easily, the main focus has always been on Linux during the design of
2966 U-Boot includes many features that so far have been part of some
2967 special "boot loader" code within the Linux kernel. Also, any
2968 "initrd" images to be used are no longer part of one big Linux image;
2969 instead, kernel and "initrd" are separate images. This implementation
2970 serves several purposes:
2972 - the same features can be used for other OS or standalone
2973 applications (for instance: using compressed images to reduce the
2974 Flash memory footprint)
2976 - it becomes much easier to port new Linux kernel versions because
2977 lots of low-level, hardware dependent stuff are done by U-Boot
2979 - the same Linux kernel image can now be used with different "initrd"
2980 images; of course this also means that different kernel images can
2981 be run with the same "initrd". This makes testing easier (you don't
2982 have to build a new "zImage.initrd" Linux image when you just
2983 change a file in your "initrd"). Also, a field-upgrade of the
2984 software is easier now.
2990 Porting Linux to U-Boot based systems:
2991 ---------------------------------------
2993 U-Boot cannot save you from doing all the necessary modifications to
2994 configure the Linux device drivers for use with your target hardware
2995 (no, we don't intend to provide a full virtual machine interface to
2998 But now you can ignore ALL boot loader code (in arch/ppc/mbxboot).
3000 Just make sure your machine specific header file (for instance
3001 include/asm-ppc/tqm8xx.h) includes the same definition of the Board
3002 Information structure as we define in include/u-boot.h, and make
3003 sure that your definition of IMAP_ADDR uses the same value as your
3004 U-Boot configuration in CFG_IMMR.
3007 Configuring the Linux kernel:
3008 -----------------------------
3010 No specific requirements for U-Boot. Make sure you have some root
3011 device (initial ramdisk, NFS) for your target system.
3014 Building a Linux Image:
3015 -----------------------
3017 With U-Boot, "normal" build targets like "zImage" or "bzImage" are
3018 not used. If you use recent kernel source, a new build target
3019 "uImage" will exist which automatically builds an image usable by
3020 U-Boot. Most older kernels also have support for a "pImage" target,
3021 which was introduced for our predecessor project PPCBoot and uses a
3022 100% compatible format.
3031 The "uImage" build target uses a special tool (in 'tools/mkimage') to
3032 encapsulate a compressed Linux kernel image with header information,
3033 CRC32 checksum etc. for use with U-Boot. This is what we are doing:
3035 * build a standard "vmlinux" kernel image (in ELF binary format):
3037 * convert the kernel into a raw binary image:
3039 ${CROSS_COMPILE}-objcopy -O binary \
3040 -R .note -R .comment \
3041 -S vmlinux linux.bin
3043 * compress the binary image:
3047 * package compressed binary image for U-Boot:
3049 mkimage -A ppc -O linux -T kernel -C gzip \
3050 -a 0 -e 0 -n "Linux Kernel Image" \
3051 -d linux.bin.gz uImage
3054 The "mkimage" tool can also be used to create ramdisk images for use
3055 with U-Boot, either separated from the Linux kernel image, or
3056 combined into one file. "mkimage" encapsulates the images with a 64
3057 byte header containing information about target architecture,
3058 operating system, image type, compression method, entry points, time
3059 stamp, CRC32 checksums, etc.
3061 "mkimage" can be called in two ways: to verify existing images and
3062 print the header information, or to build new images.
3064 In the first form (with "-l" option) mkimage lists the information
3065 contained in the header of an existing U-Boot image; this includes
3066 checksum verification:
3068 tools/mkimage -l image
3069 -l ==> list image header information
3071 The second form (with "-d" option) is used to build a U-Boot image
3072 from a "data file" which is used as image payload:
3074 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
3075 -n name -d data_file image
3076 -A ==> set architecture to 'arch'
3077 -O ==> set operating system to 'os'
3078 -T ==> set image type to 'type'
3079 -C ==> set compression type 'comp'
3080 -a ==> set load address to 'addr' (hex)
3081 -e ==> set entry point to 'ep' (hex)
3082 -n ==> set image name to 'name'
3083 -d ==> use image data from 'datafile'
3085 Right now, all Linux kernels for PowerPC systems use the same load
3086 address (0x00000000), but the entry point address depends on the
3089 - 2.2.x kernels have the entry point at 0x0000000C,
3090 - 2.3.x and later kernels have the entry point at 0x00000000.
3092 So a typical call to build a U-Boot image would read:
3094 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
3095 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
3096 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux.gz \
3097 > examples/uImage.TQM850L
3098 Image Name: 2.4.4 kernel for TQM850L
3099 Created: Wed Jul 19 02:34:59 2000
3100 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3101 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
3102 Load Address: 0x00000000
3103 Entry Point: 0x00000000
3105 To verify the contents of the image (or check for corruption):
3107 -> tools/mkimage -l examples/uImage.TQM850L
3108 Image Name: 2.4.4 kernel for TQM850L
3109 Created: Wed Jul 19 02:34:59 2000
3110 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3111 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
3112 Load Address: 0x00000000
3113 Entry Point: 0x00000000
3115 NOTE: for embedded systems where boot time is critical you can trade
3116 speed for memory and install an UNCOMPRESSED image instead: this
3117 needs more space in Flash, but boots much faster since it does not
3118 need to be uncompressed:
3120 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux.gz
3121 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
3122 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
3123 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux \
3124 > examples/uImage.TQM850L-uncompressed
3125 Image Name: 2.4.4 kernel for TQM850L
3126 Created: Wed Jul 19 02:34:59 2000
3127 Image Type: PowerPC Linux Kernel Image (uncompressed)
3128 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
3129 Load Address: 0x00000000
3130 Entry Point: 0x00000000
3133 Similar you can build U-Boot images from a 'ramdisk.image.gz' file
3134 when your kernel is intended to use an initial ramdisk:
3136 -> tools/mkimage -n 'Simple Ramdisk Image' \
3137 > -A ppc -O linux -T ramdisk -C gzip \
3138 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
3139 Image Name: Simple Ramdisk Image
3140 Created: Wed Jan 12 14:01:50 2000
3141 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
3142 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
3143 Load Address: 0x00000000
3144 Entry Point: 0x00000000
3147 Installing a Linux Image:
3148 -------------------------
3150 To downloading a U-Boot image over the serial (console) interface,
3151 you must convert the image to S-Record format:
3153 objcopy -I binary -O srec examples/image examples/image.srec
3155 The 'objcopy' does not understand the information in the U-Boot
3156 image header, so the resulting S-Record file will be relative to
3157 address 0x00000000. To load it to a given address, you need to
3158 specify the target address as 'offset' parameter with the 'loads'
3161 Example: install the image to address 0x40100000 (which on the
3162 TQM8xxL is in the first Flash bank):
3164 => erase 40100000 401FFFFF
3170 ## Ready for S-Record download ...
3171 ~>examples/image.srec
3172 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
3174 15989 15990 15991 15992
3175 [file transfer complete]
3177 ## Start Addr = 0x00000000
3180 You can check the success of the download using the 'iminfo' command;
3181 this includes a checksum verification so you can be sure no data
3182 corruption happened:
3186 ## Checking Image at 40100000 ...
3187 Image Name: 2.2.13 for initrd on TQM850L
3188 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3189 Data Size: 335725 Bytes = 327 kB = 0 MB
3190 Load Address: 00000000
3191 Entry Point: 0000000c
3192 Verifying Checksum ... OK
3198 The "bootm" command is used to boot an application that is stored in
3199 memory (RAM or Flash). In case of a Linux kernel image, the contents
3200 of the "bootargs" environment variable is passed to the kernel as
3201 parameters. You can check and modify this variable using the
3202 "printenv" and "setenv" commands:
3205 => printenv bootargs
3206 bootargs=root=/dev/ram
3208 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
3210 => printenv bootargs
3211 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
3214 ## Booting Linux kernel at 40020000 ...
3215 Image Name: 2.2.13 for NFS on TQM850L
3216 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3217 Data Size: 381681 Bytes = 372 kB = 0 MB
3218 Load Address: 00000000
3219 Entry Point: 0000000c
3220 Verifying Checksum ... OK
3221 Uncompressing Kernel Image ... OK
3222 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
3223 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
3224 time_init: decrementer frequency = 187500000/60
3225 Calibrating delay loop... 49.77 BogoMIPS
3226 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
3229 If you want to boot a Linux kernel with initial ram disk, you pass
3230 the memory addresses of both the kernel and the initrd image (PPBCOOT
3231 format!) to the "bootm" command:
3233 => imi 40100000 40200000
3235 ## Checking Image at 40100000 ...
3236 Image Name: 2.2.13 for initrd on TQM850L
3237 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3238 Data Size: 335725 Bytes = 327 kB = 0 MB
3239 Load Address: 00000000
3240 Entry Point: 0000000c
3241 Verifying Checksum ... OK
3243 ## Checking Image at 40200000 ...
3244 Image Name: Simple Ramdisk Image
3245 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
3246 Data Size: 566530 Bytes = 553 kB = 0 MB
3247 Load Address: 00000000
3248 Entry Point: 00000000
3249 Verifying Checksum ... OK
3251 => bootm 40100000 40200000
3252 ## Booting Linux kernel at 40100000 ...
3253 Image Name: 2.2.13 for initrd on TQM850L
3254 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3255 Data Size: 335725 Bytes = 327 kB = 0 MB
3256 Load Address: 00000000
3257 Entry Point: 0000000c
3258 Verifying Checksum ... OK
3259 Uncompressing Kernel Image ... OK
3260 ## Loading RAMDisk Image at 40200000 ...
3261 Image Name: Simple Ramdisk Image
3262 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
3263 Data Size: 566530 Bytes = 553 kB = 0 MB
3264 Load Address: 00000000
3265 Entry Point: 00000000
3266 Verifying Checksum ... OK
3267 Loading Ramdisk ... OK
3268 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
3269 Boot arguments: root=/dev/ram
3270 time_init: decrementer frequency = 187500000/60
3271 Calibrating delay loop... 49.77 BogoMIPS
3273 RAMDISK: Compressed image found at block 0
3274 VFS: Mounted root (ext2 filesystem).
3278 Boot Linux and pass a flat device tree:
3281 First, U-Boot must be compiled with the appropriate defines. See the section
3282 titled "Linux Kernel Interface" above for a more in depth explanation. The
3283 following is an example of how to start a kernel and pass an updated
3289 oft=oftrees/mpc8540ads.dtb
3290 => tftp $oftaddr $oft
3291 Speed: 1000, full duplex
3293 TFTP from server 192.168.1.1; our IP address is 192.168.1.101
3294 Filename 'oftrees/mpc8540ads.dtb'.
3295 Load address: 0x300000
3298 Bytes transferred = 4106 (100a hex)
3299 => tftp $loadaddr $bootfile
3300 Speed: 1000, full duplex
3302 TFTP from server 192.168.1.1; our IP address is 192.168.1.2
3304 Load address: 0x200000
3305 Loading:############
3307 Bytes transferred = 1029407 (fb51f hex)
3312 => bootm $loadaddr - $oftaddr
3313 ## Booting image at 00200000 ...
3314 Image Name: Linux-2.6.17-dirty
3315 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3316 Data Size: 1029343 Bytes = 1005.2 kB
3317 Load Address: 00000000
3318 Entry Point: 00000000
3319 Verifying Checksum ... OK
3320 Uncompressing Kernel Image ... OK
3321 Booting using flat device tree at 0x300000
3322 Using MPC85xx ADS machine description
3323 Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb
3327 More About U-Boot Image Types:
3328 ------------------------------
3330 U-Boot supports the following image types:
3332 "Standalone Programs" are directly runnable in the environment
3333 provided by U-Boot; it is expected that (if they behave
3334 well) you can continue to work in U-Boot after return from
3335 the Standalone Program.
3336 "OS Kernel Images" are usually images of some Embedded OS which
3337 will take over control completely. Usually these programs
3338 will install their own set of exception handlers, device
3339 drivers, set up the MMU, etc. - this means, that you cannot
3340 expect to re-enter U-Boot except by resetting the CPU.
3341 "RAMDisk Images" are more or less just data blocks, and their
3342 parameters (address, size) are passed to an OS kernel that is
3344 "Multi-File Images" contain several images, typically an OS
3345 (Linux) kernel image and one or more data images like
3346 RAMDisks. This construct is useful for instance when you want
3347 to boot over the network using BOOTP etc., where the boot
3348 server provides just a single image file, but you want to get
3349 for instance an OS kernel and a RAMDisk image.
3351 "Multi-File Images" start with a list of image sizes, each
3352 image size (in bytes) specified by an "uint32_t" in network
3353 byte order. This list is terminated by an "(uint32_t)0".
3354 Immediately after the terminating 0 follow the images, one by
3355 one, all aligned on "uint32_t" boundaries (size rounded up to
3356 a multiple of 4 bytes).
3358 "Firmware Images" are binary images containing firmware (like
3359 U-Boot or FPGA images) which usually will be programmed to
3362 "Script files" are command sequences that will be executed by
3363 U-Boot's command interpreter; this feature is especially
3364 useful when you configure U-Boot to use a real shell (hush)
3365 as command interpreter.
3371 One of the features of U-Boot is that you can dynamically load and
3372 run "standalone" applications, which can use some resources of
3373 U-Boot like console I/O functions or interrupt services.
3375 Two simple examples are included with the sources:
3380 'examples/hello_world.c' contains a small "Hello World" Demo
3381 application; it is automatically compiled when you build U-Boot.
3382 It's configured to run at address 0x00040004, so you can play with it
3386 ## Ready for S-Record download ...
3387 ~>examples/hello_world.srec
3388 1 2 3 4 5 6 7 8 9 10 11 ...
3389 [file transfer complete]
3391 ## Start Addr = 0x00040004
3393 => go 40004 Hello World! This is a test.
3394 ## Starting application at 0x00040004 ...
3405 Hit any key to exit ...
3407 ## Application terminated, rc = 0x0
3409 Another example, which demonstrates how to register a CPM interrupt
3410 handler with the U-Boot code, can be found in 'examples/timer.c'.
3411 Here, a CPM timer is set up to generate an interrupt every second.
3412 The interrupt service routine is trivial, just printing a '.'
3413 character, but this is just a demo program. The application can be
3414 controlled by the following keys:
3416 ? - print current values og the CPM Timer registers
3417 b - enable interrupts and start timer
3418 e - stop timer and disable interrupts
3419 q - quit application
3422 ## Ready for S-Record download ...
3423 ~>examples/timer.srec
3424 1 2 3 4 5 6 7 8 9 10 11 ...
3425 [file transfer complete]
3427 ## Start Addr = 0x00040004
3430 ## Starting application at 0x00040004 ...
3433 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
3436 [q, b, e, ?] Set interval 1000000 us
3439 [q, b, e, ?] ........
3440 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
3443 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
3446 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
3449 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
3451 [q, b, e, ?] ...Stopping timer
3453 [q, b, e, ?] ## Application terminated, rc = 0x0
3459 Over time, many people have reported problems when trying to use the
3460 "minicom" terminal emulation program for serial download. I (wd)
3461 consider minicom to be broken, and recommend not to use it. Under
3462 Unix, I recommend to use C-Kermit for general purpose use (and
3463 especially for kermit binary protocol download ("loadb" command), and
3464 use "cu" for S-Record download ("loads" command).
3466 Nevertheless, if you absolutely want to use it try adding this
3467 configuration to your "File transfer protocols" section:
3469 Name Program Name U/D FullScr IO-Red. Multi
3470 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
3471 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
3477 Starting at version 0.9.2, U-Boot supports NetBSD both as host
3478 (build U-Boot) and target system (boots NetBSD/mpc8xx).
3480 Building requires a cross environment; it is known to work on
3481 NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
3482 need gmake since the Makefiles are not compatible with BSD make).
3483 Note that the cross-powerpc package does not install include files;
3484 attempting to build U-Boot will fail because <machine/ansi.h> is
3485 missing. This file has to be installed and patched manually:
3487 # cd /usr/pkg/cross/powerpc-netbsd/include
3489 # ln -s powerpc machine
3490 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
3491 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
3493 Native builds *don't* work due to incompatibilities between native
3494 and U-Boot include files.
3496 Booting assumes that (the first part of) the image booted is a
3497 stage-2 loader which in turn loads and then invokes the kernel
3498 proper. Loader sources will eventually appear in the NetBSD source
3499 tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
3500 meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz
3503 Implementation Internals:
3504 =========================
3506 The following is not intended to be a complete description of every
3507 implementation detail. However, it should help to understand the
3508 inner workings of U-Boot and make it easier to port it to custom
3512 Initial Stack, Global Data:
3513 ---------------------------
3515 The implementation of U-Boot is complicated by the fact that U-Boot
3516 starts running out of ROM (flash memory), usually without access to
3517 system RAM (because the memory controller is not initialized yet).
3518 This means that we don't have writable Data or BSS segments, and BSS
3519 is not initialized as zero. To be able to get a C environment working
3520 at all, we have to allocate at least a minimal stack. Implementation
3521 options for this are defined and restricted by the CPU used: Some CPU
3522 models provide on-chip memory (like the IMMR area on MPC8xx and
3523 MPC826x processors), on others (parts of) the data cache can be
3524 locked as (mis-) used as memory, etc.
3526 Chris Hallinan posted a good summary of these issues to the
3527 u-boot-users mailing list:
3529 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
3530 From: "Chris Hallinan" <clh@net1plus.com>
3531 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
3534 Correct me if I'm wrong, folks, but the way I understand it
3535 is this: Using DCACHE as initial RAM for Stack, etc, does not
3536 require any physical RAM backing up the cache. The cleverness
3537 is that the cache is being used as a temporary supply of
3538 necessary storage before the SDRAM controller is setup. It's
3539 beyond the scope of this list to expain the details, but you
3540 can see how this works by studying the cache architecture and
3541 operation in the architecture and processor-specific manuals.
3543 OCM is On Chip Memory, which I believe the 405GP has 4K. It
3544 is another option for the system designer to use as an
3545 initial stack/ram area prior to SDRAM being available. Either
3546 option should work for you. Using CS 4 should be fine if your
3547 board designers haven't used it for something that would
3548 cause you grief during the initial boot! It is frequently not
3551 CFG_INIT_RAM_ADDR should be somewhere that won't interfere
3552 with your processor/board/system design. The default value
3553 you will find in any recent u-boot distribution in
3554 walnut.h should work for you. I'd set it to a value larger
3555 than your SDRAM module. If you have a 64MB SDRAM module, set
3556 it above 400_0000. Just make sure your board has no resources
3557 that are supposed to respond to that address! That code in
3558 start.S has been around a while and should work as is when
3559 you get the config right.
3564 It is essential to remember this, since it has some impact on the C
3565 code for the initialization procedures:
3567 * Initialized global data (data segment) is read-only. Do not attempt
3570 * Do not use any unitialized global data (or implicitely initialized
3571 as zero data - BSS segment) at all - this is undefined, initiali-
3572 zation is performed later (when relocating to RAM).
3574 * Stack space is very limited. Avoid big data buffers or things like
3577 Having only the stack as writable memory limits means we cannot use
3578 normal global data to share information beween the code. But it
3579 turned out that the implementation of U-Boot can be greatly
3580 simplified by making a global data structure (gd_t) available to all
3581 functions. We could pass a pointer to this data as argument to _all_
3582 functions, but this would bloat the code. Instead we use a feature of
3583 the GCC compiler (Global Register Variables) to share the data: we
3584 place a pointer (gd) to the global data into a register which we
3585 reserve for this purpose.
3587 When choosing a register for such a purpose we are restricted by the
3588 relevant (E)ABI specifications for the current architecture, and by
3589 GCC's implementation.
3591 For PowerPC, the following registers have specific use:
3594 R3-R4: parameter passing and return values
3595 R5-R10: parameter passing
3596 R13: small data area pointer
3600 (U-Boot also uses R14 as internal GOT pointer.)
3602 ==> U-Boot will use R29 to hold a pointer to the global data
3604 Note: on PPC, we could use a static initializer (since the
3605 address of the global data structure is known at compile time),
3606 but it turned out that reserving a register results in somewhat
3607 smaller code - although the code savings are not that big (on
3608 average for all boards 752 bytes for the whole U-Boot image,
3609 624 text + 127 data).
3611 On ARM, the following registers are used:
3613 R0: function argument word/integer result
3614 R1-R3: function argument word
3616 R10: stack limit (used only if stack checking if enabled)
3617 R11: argument (frame) pointer
3618 R12: temporary workspace
3621 R15: program counter
3623 ==> U-Boot will use R8 to hold a pointer to the global data
3625 NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope,
3626 or current versions of GCC may "optimize" the code too much.
3631 U-Boot runs in system state and uses physical addresses, i.e. the
3632 MMU is not used either for address mapping nor for memory protection.
3634 The available memory is mapped to fixed addresses using the memory
3635 controller. In this process, a contiguous block is formed for each
3636 memory type (Flash, SDRAM, SRAM), even when it consists of several
3637 physical memory banks.
3639 U-Boot is installed in the first 128 kB of the first Flash bank (on
3640 TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
3641 booting and sizing and initializing DRAM, the code relocates itself
3642 to the upper end of DRAM. Immediately below the U-Boot code some
3643 memory is reserved for use by malloc() [see CFG_MALLOC_LEN
3644 configuration setting]. Below that, a structure with global Board
3645 Info data is placed, followed by the stack (growing downward).
3647 Additionally, some exception handler code is copied to the low 8 kB
3648 of DRAM (0x00000000 ... 0x00001FFF).
3650 So a typical memory configuration with 16 MB of DRAM could look like
3653 0x0000 0000 Exception Vector code
3656 0x0000 2000 Free for Application Use
3662 0x00FB FF20 Monitor Stack (Growing downward)
3663 0x00FB FFAC Board Info Data and permanent copy of global data
3664 0x00FC 0000 Malloc Arena
3667 0x00FE 0000 RAM Copy of Monitor Code
3668 ... eventually: LCD or video framebuffer
3669 ... eventually: pRAM (Protected RAM - unchanged by reset)
3670 0x00FF FFFF [End of RAM]
3673 System Initialization:
3674 ----------------------
3676 In the reset configuration, U-Boot starts at the reset entry point
3677 (on most PowerPC systens at address 0x00000100). Because of the reset
3678 configuration for CS0# this is a mirror of the onboard Flash memory.
3679 To be able to re-map memory U-Boot then jumps to its link address.
3680 To be able to implement the initialization code in C, a (small!)
3681 initial stack is set up in the internal Dual Ported RAM (in case CPUs
3682 which provide such a feature like MPC8xx or MPC8260), or in a locked
3683 part of the data cache. After that, U-Boot initializes the CPU core,
3684 the caches and the SIU.
3686 Next, all (potentially) available memory banks are mapped using a
3687 preliminary mapping. For example, we put them on 512 MB boundaries
3688 (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
3689 on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
3690 programmed for SDRAM access. Using the temporary configuration, a
3691 simple memory test is run that determines the size of the SDRAM
3694 When there is more than one SDRAM bank, and the banks are of
3695 different size, the largest is mapped first. For equal size, the first
3696 bank (CS2#) is mapped first. The first mapping is always for address
3697 0x00000000, with any additional banks following immediately to create
3698 contiguous memory starting from 0.
3700 Then, the monitor installs itself at the upper end of the SDRAM area
3701 and allocates memory for use by malloc() and for the global Board
3702 Info data; also, the exception vector code is copied to the low RAM
3703 pages, and the final stack is set up.
3705 Only after this relocation will you have a "normal" C environment;
3706 until that you are restricted in several ways, mostly because you are
3707 running from ROM, and because the code will have to be relocated to a
3711 U-Boot Porting Guide:
3712 ----------------------
3714 [Based on messages by Jerry Van Baren in the U-Boot-Users mailing
3718 int main (int argc, char *argv[])
3720 sighandler_t no_more_time;
3722 signal (SIGALRM, no_more_time);
3723 alarm (PROJECT_DEADLINE - toSec (3 * WEEK));
3725 if (available_money > available_manpower) {
3726 pay consultant to port U-Boot;
3730 Download latest U-Boot source;
3732 Subscribe to u-boot-users mailing list;
3735 email ("Hi, I am new to U-Boot, how do I get started?");
3739 Read the README file in the top level directory;
3740 Read http://www.denx.de/twiki/bin/view/DULG/Manual ;
3741 Read the source, Luke;
3744 if (available_money > toLocalCurrency ($2500)) {
3747 Add a lot of aggravation and time;
3750 Create your own board support subdirectory;
3752 Create your own board config file;
3756 Add / modify source code;
3760 email ("Hi, I am having problems...");
3762 Send patch file to Wolfgang;
3767 void no_more_time (int sig)
3776 All contributions to U-Boot should conform to the Linux kernel
3777 coding style; see the file "Documentation/CodingStyle" and the script
3778 "scripts/Lindent" in your Linux kernel source directory. In sources
3779 originating from U-Boot a style corresponding to "Lindent -pcs" (adding
3780 spaces before parameters to function calls) is actually used.
3782 Source files originating from a different project (for example the
3783 MTD subsystem) are generally exempt from these guidelines and are not
3784 reformated to ease subsequent migration to newer versions of those
3787 Please note that U-Boot is implemented in C (and to some small parts in
3788 Assembler); no C++ is used, so please do not use C++ style comments (//)
3791 Please also stick to the following formatting rules:
3792 - remove any trailing white space
3793 - use TAB characters for indentation, not spaces
3794 - make sure NOT to use DOS '\r\n' line feeds
3795 - do not add more than 2 empty lines to source files
3796 - do not add trailing empty lines to source files
3798 Submissions which do not conform to the standards may be returned
3799 with a request to reformat the changes.
3805 Since the number of patches for U-Boot is growing, we need to
3806 establish some rules. Submissions which do not conform to these rules
3807 may be rejected, even when they contain important and valuable stuff.
3809 Patches shall be sent to the u-boot-users mailing list.
3811 When you send a patch, please include the following information with
3814 * For bug fixes: a description of the bug and how your patch fixes
3815 this bug. Please try to include a way of demonstrating that the
3816 patch actually fixes something.
3818 * For new features: a description of the feature and your
3821 * A CHANGELOG entry as plaintext (separate from the patch)
3823 * For major contributions, your entry to the CREDITS file
3825 * When you add support for a new board, don't forget to add this
3826 board to the MAKEALL script, too.
3828 * If your patch adds new configuration options, don't forget to
3829 document these in the README file.
3831 * The patch itself. If you are accessing the CVS repository use "cvs
3832 update; cvs diff -puRN"; else, use "diff -purN OLD NEW". If your
3833 version of diff does not support these options, then get the latest
3834 version of GNU diff.
3836 The current directory when running this command shall be the top
3837 level directory of the U-Boot source tree, or it's parent directory
3838 (i. e. please make sure that your patch includes sufficient
3839 directory information for the affected files).
3841 We accept patches as plain text, MIME attachments or as uuencoded
3844 * If one logical set of modifications affects or creates several
3845 files, all these changes shall be submitted in a SINGLE patch file.
3847 * Changesets that contain different, unrelated modifications shall be
3848 submitted as SEPARATE patches, one patch per changeset.
3853 * Before sending the patch, run the MAKEALL script on your patched
3854 source tree and make sure that no errors or warnings are reported
3855 for any of the boards.
3857 * Keep your modifications to the necessary minimum: A patch
3858 containing several unrelated changes or arbitrary reformats will be
3859 returned with a request to re-formatting / split it.
3861 * If you modify existing code, make sure that your new code does not
3862 add to the memory footprint of the code ;-) Small is beautiful!
3863 When adding new features, these should compile conditionally only
3864 (using #ifdef), and the resulting code with the new feature
3865 disabled must not need more memory than the old code without your
3868 * Remember that there is a size limit of 40 kB per message on the
3869 u-boot-users mailing list. Compression may help.
projects / karo-tx-uboot.git / blob