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 - net Networking code
168 - post Power On Self Test
169 - rtc Real Time Clock drivers
170 - tools Tools to build S-Record or U-Boot images, etc.
172 Software Configuration:
173 =======================
175 Configuration is usually done using C preprocessor defines; the
176 rationale behind that is to avoid dead code whenever possible.
178 There are two classes of configuration variables:
180 * Configuration _OPTIONS_:
181 These are selectable by the user and have names beginning with
184 * Configuration _SETTINGS_:
185 These depend on the hardware etc. and should not be meddled with if
186 you don't know what you're doing; they have names beginning with
189 Later we will add a configuration tool - probably similar to or even
190 identical to what's used for the Linux kernel. Right now, we have to
191 do the configuration by hand, which means creating some symbolic
192 links and editing some configuration files. We use the TQM8xxL boards
196 Selection of Processor Architecture and Board Type:
197 ---------------------------------------------------
199 For all supported boards there are ready-to-use default
200 configurations available; just type "make <board_name>_config".
202 Example: For a TQM823L module type:
207 For the Cogent platform, you need to specify the cpu type as well;
208 e.g. "make cogent_mpc8xx_config". And also configure the cogent
209 directory according to the instructions in cogent/README.
212 Configuration Options:
213 ----------------------
215 Configuration depends on the combination of board and CPU type; all
216 such information is kept in a configuration file
217 "include/configs/<board_name>.h".
219 Example: For a TQM823L module, all configuration settings are in
220 "include/configs/TQM823L.h".
223 Many of the options are named exactly as the corresponding Linux
224 kernel configuration options. The intention is to make it easier to
225 build a config tool - later.
228 The following options need to be configured:
230 - CPU Type: Define exactly one of
234 CONFIG_MPC823, CONFIG_MPC850, CONFIG_MPC855, CONFIG_MPC860
237 or CONFIG_MPC824X, CONFIG_MPC8260
253 MicroBlaze based CPUs:
254 ----------------------
258 ----------------------
262 ----------------------
265 - Board Type: Define exactly one of
267 PowerPC based boards:
268 ---------------------
270 CONFIG_ADCIOP CONFIG_FPS860L CONFIG_OXC
271 CONFIG_ADS860 CONFIG_GEN860T CONFIG_PCI405
272 CONFIG_AMX860 CONFIG_GENIETV CONFIG_PCIPPC2
273 CONFIG_AP1000 CONFIG_GTH CONFIG_PCIPPC6
274 CONFIG_AR405 CONFIG_gw8260 CONFIG_pcu_e
275 CONFIG_BAB7xx CONFIG_hermes CONFIG_PIP405
276 CONFIG_BC3450 CONFIG_hymod CONFIG_PM826
277 CONFIG_c2mon CONFIG_IAD210 CONFIG_ppmc8260
278 CONFIG_CANBT CONFIG_ICU862 CONFIG_QS823
279 CONFIG_CCM CONFIG_IP860 CONFIG_QS850
280 CONFIG_CMI CONFIG_IPHASE4539 CONFIG_QS860T
281 CONFIG_cogent_mpc8260 CONFIG_IVML24 CONFIG_RBC823
282 CONFIG_cogent_mpc8xx CONFIG_IVML24_128 CONFIG_RPXClassic
283 CONFIG_CPCI405 CONFIG_IVML24_256 CONFIG_RPXlite
284 CONFIG_CPCI4052 CONFIG_IVMS8 CONFIG_RPXsuper
285 CONFIG_CPCIISER4 CONFIG_IVMS8_128 CONFIG_rsdproto
286 CONFIG_CPU86 CONFIG_IVMS8_256 CONFIG_sacsng
287 CONFIG_CRAYL1 CONFIG_JSE CONFIG_Sandpoint8240
288 CONFIG_CSB272 CONFIG_LANTEC CONFIG_Sandpoint8245
289 CONFIG_CU824 CONFIG_LITE5200B CONFIG_sbc8260
290 CONFIG_DASA_SIM CONFIG_lwmon CONFIG_sbc8560
291 CONFIG_DB64360 CONFIG_MBX CONFIG_SM850
292 CONFIG_DB64460 CONFIG_MBX860T CONFIG_SPD823TS
293 CONFIG_DU405 CONFIG_MHPC CONFIG_STXGP3
294 CONFIG_DUET_ADS CONFIG_MIP405 CONFIG_SXNI855T
295 CONFIG_EBONY CONFIG_MOUSSE CONFIG_TQM823L
296 CONFIG_ELPPC CONFIG_MPC8260ADS CONFIG_TQM8260
297 CONFIG_ELPT860 CONFIG_MPC8540ADS CONFIG_TQM850L
298 CONFIG_ep8260 CONFIG_MPC8540EVAL CONFIG_TQM855L
299 CONFIG_ERIC CONFIG_MPC8560ADS CONFIG_TQM860L
300 CONFIG_ESTEEM192E CONFIG_MUSENKI CONFIG_TTTech
301 CONFIG_ETX094 CONFIG_MVS1 CONFIG_UTX8245
302 CONFIG_EVB64260 CONFIG_NETPHONE CONFIG_V37
303 CONFIG_FADS823 CONFIG_NETTA CONFIG_W7OLMC
304 CONFIG_FADS850SAR CONFIG_NETVIA CONFIG_W7OLMG
305 CONFIG_FADS860T CONFIG_NX823 CONFIG_WALNUT
306 CONFIG_FLAGADM CONFIG_OCRTC CONFIG_ZPC1900
307 CONFIG_FPS850L CONFIG_ORSG CONFIG_ZUMA
312 CONFIG_ARMADILLO, CONFIG_AT91RM9200DK, CONFIG_CERF250,
313 CONFIG_CSB637, CONFIG_DELTA, CONFIG_DNP1110,
314 CONFIG_EP7312, CONFIG_H2_OMAP1610, CONFIG_HHP_CRADLE,
315 CONFIG_IMPA7, CONFIG_INNOVATOROMAP1510, CONFIG_INNOVATOROMAP1610,
316 CONFIG_KB9202, CONFIG_LART, CONFIG_LPD7A400,
317 CONFIG_LUBBOCK, CONFIG_OSK_OMAP5912, CONFIG_OMAP2420H4,
318 CONFIG_PLEB2, CONFIG_SHANNON, CONFIG_P2_OMAP730,
319 CONFIG_SMDK2400, CONFIG_SMDK2410, CONFIG_TRAB,
322 MicroBlaze based boards:
323 ------------------------
328 ------------------------
330 CONFIG_PCI5441 CONFIG_PK1C20
331 CONFIG_EP1C20 CONFIG_EP1S10 CONFIG_EP1S40
338 - CPU Daughterboard Type: (if CONFIG_ATSTK1000 is defined)
339 Define exactly one of
343 - CPU Module Type: (if CONFIG_COGENT is defined)
344 Define exactly one of
346 --- FIXME --- not tested yet:
347 CONFIG_CMA286_60, CONFIG_CMA286_21, CONFIG_CMA286_60P,
348 CONFIG_CMA287_23, CONFIG_CMA287_50
350 - Motherboard Type: (if CONFIG_COGENT is defined)
351 Define exactly one of
352 CONFIG_CMA101, CONFIG_CMA102
354 - Motherboard I/O Modules: (if CONFIG_COGENT is defined)
355 Define one or more of
358 - Motherboard Options: (if CONFIG_CMA101 or CONFIG_CMA102 are defined)
359 Define one or more of
360 CONFIG_LCD_HEARTBEAT - update a character position on
361 the lcd display every second with
364 - Board flavour: (if CONFIG_MPC8260ADS is defined)
367 CFG_8260ADS - original MPC8260ADS
368 CFG_8266ADS - MPC8266ADS
369 CFG_PQ2FADS - PQ2FADS-ZU or PQ2FADS-VR
370 CFG_8272ADS - MPC8272ADS
372 - MPC824X Family Member (if CONFIG_MPC824X is defined)
373 Define exactly one of
374 CONFIG_MPC8240, CONFIG_MPC8245
376 - 8xx CPU Options: (if using an MPC8xx cpu)
377 CONFIG_8xx_GCLK_FREQ - deprecated: CPU clock if
378 get_gclk_freq() cannot work
379 e.g. if there is no 32KHz
380 reference PIT/RTC clock
381 CONFIG_8xx_OSCLK - PLL input clock (either EXTCLK
384 - 859/866/885 CPU options: (if using a MPC859 or MPC866 or MPC885 CPU):
387 CONFIG_8xx_CPUCLK_DEFAULT
388 See doc/README.MPC866
392 Define this to measure the actual CPU clock instead
393 of relying on the correctness of the configured
394 values. Mostly useful for board bringup to make sure
395 the PLL is locked at the intended frequency. Note
396 that this requires a (stable) reference clock (32 kHz
397 RTC clock or CFG_8XX_XIN)
399 - Intel Monahans options:
400 CFG_MONAHANS_RUN_MODE_OSC_RATIO
402 Defines the Monahans run mode to oscillator
403 ratio. Valid values are 8, 16, 24, 31. The core
404 frequency is this value multiplied by 13 MHz.
406 CFG_MONAHANS_TURBO_RUN_MODE_RATIO
408 Defines the Monahans turbo mode to oscillator
409 ratio. Valid values are 1 (default if undefined) and
410 2. The core frequency as calculated above is multiplied
413 - Linux Kernel Interface:
416 U-Boot stores all clock information in Hz
417 internally. For binary compatibility with older Linux
418 kernels (which expect the clocks passed in the
419 bd_info data to be in MHz) the environment variable
420 "clocks_in_mhz" can be defined so that U-Boot
421 converts clock data to MHZ before passing it to the
423 When CONFIG_CLOCKS_IN_MHZ is defined, a definition of
424 "clocks_in_mhz=1" is automatically included in the
427 CONFIG_MEMSIZE_IN_BYTES [relevant for MIPS only]
429 When transfering memsize parameter to linux, some versions
430 expect it to be in bytes, others in MB.
431 Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes.
435 New kernel versions are expecting firmware settings to be
436 passed using flat open firmware trees.
437 The environment variable "disable_of", when set, disables this
440 CONFIG_OF_FLAT_TREE_MAX_SIZE
442 The maximum size of the constructed OF tree.
444 OF_CPU - The proper name of the cpus node.
445 OF_SOC - The proper name of the soc node.
446 OF_TBCLK - The timebase frequency.
447 OF_STDOUT_PATH - The path to the console device
451 The resulting flat device tree will have a copy of the bd_t.
452 Space should be pre-allocated in the dts for the bd_t.
454 CONFIG_OF_HAS_UBOOT_ENV
456 The resulting flat device tree will have a copy of u-boot's
457 environment variables
459 CONFIG_OF_BOARD_SETUP
461 Board code has addition modification that it wants to make
462 to the flat device tree before handing it off to the kernel
466 This define fills in the correct boot cpu in the boot
467 param header, the default value is zero if undefined.
472 Define this if you want support for Amba PrimeCell PL010 UARTs.
476 Define this if you want support for Amba PrimeCell PL011 UARTs.
480 If you have Amba PrimeCell PL011 UARTs, set this variable to
481 the clock speed of the UARTs.
485 If you have Amba PrimeCell PL010 or PL011 UARTs on your board,
486 define this to a list of base addresses for each (supported)
487 port. See e.g. include/configs/versatile.h
491 Depending on board, define exactly one serial port
492 (like CONFIG_8xx_CONS_SMC1, CONFIG_8xx_CONS_SMC2,
493 CONFIG_8xx_CONS_SCC1, ...), or switch off the serial
494 console by defining CONFIG_8xx_CONS_NONE
496 Note: if CONFIG_8xx_CONS_NONE is defined, the serial
497 port routines must be defined elsewhere
498 (i.e. serial_init(), serial_getc(), ...)
501 Enables console device for a color framebuffer. Needs following
502 defines (cf. smiLynxEM, i8042, board/eltec/bab7xx)
503 VIDEO_FB_LITTLE_ENDIAN graphic memory organisation
505 VIDEO_HW_RECTFILL graphic chip supports
508 VIDEO_HW_BITBLT graphic chip supports
509 bit-blit (cf. smiLynxEM)
510 VIDEO_VISIBLE_COLS visible pixel columns
512 VIDEO_VISIBLE_ROWS visible pixel rows
513 VIDEO_PIXEL_SIZE bytes per pixel
514 VIDEO_DATA_FORMAT graphic data format
515 (0-5, cf. cfb_console.c)
516 VIDEO_FB_ADRS framebuffer address
517 VIDEO_KBD_INIT_FCT keyboard int fct
518 (i.e. i8042_kbd_init())
519 VIDEO_TSTC_FCT test char fct
521 VIDEO_GETC_FCT get char fct
523 CONFIG_CONSOLE_CURSOR cursor drawing on/off
524 (requires blink timer
526 CFG_CONSOLE_BLINK_COUNT blink interval (cf. i8042.c)
527 CONFIG_CONSOLE_TIME display time/date info in
529 (requires CFG_CMD_DATE)
530 CONFIG_VIDEO_LOGO display Linux logo in
532 CONFIG_VIDEO_BMP_LOGO use bmp_logo.h instead of
533 linux_logo.h for logo.
534 Requires CONFIG_VIDEO_LOGO
535 CONFIG_CONSOLE_EXTRA_INFO
536 addional board info beside
539 When CONFIG_CFB_CONSOLE is defined, video console is
540 default i/o. Serial console can be forced with
541 environment 'console=serial'.
543 When CONFIG_SILENT_CONSOLE is defined, all console
544 messages (by U-Boot and Linux!) can be silenced with
545 the "silent" environment variable. See
546 doc/README.silent for more information.
549 CONFIG_BAUDRATE - in bps
550 Select one of the baudrates listed in
551 CFG_BAUDRATE_TABLE, see below.
552 CFG_BRGCLK_PRESCALE, baudrate prescale
554 - Interrupt driven serial port input:
555 CONFIG_SERIAL_SOFTWARE_FIFO
558 Use an interrupt handler for receiving data on the
559 serial port. It also enables using hardware handshake
560 (RTS/CTS) and UART's built-in FIFO. Set the number of
561 bytes the interrupt driven input buffer should have.
563 Leave undefined to disable this feature, including
564 disable the buffer and hardware handshake.
566 - Console UART Number:
570 If defined internal UART1 (and not UART0) is used
571 as default U-Boot console.
573 - Boot Delay: CONFIG_BOOTDELAY - in seconds
574 Delay before automatically booting the default image;
575 set to -1 to disable autoboot.
577 See doc/README.autoboot for these options that
578 work with CONFIG_BOOTDELAY. None are required.
579 CONFIG_BOOT_RETRY_TIME
580 CONFIG_BOOT_RETRY_MIN
581 CONFIG_AUTOBOOT_KEYED
582 CONFIG_AUTOBOOT_PROMPT
583 CONFIG_AUTOBOOT_DELAY_STR
584 CONFIG_AUTOBOOT_STOP_STR
585 CONFIG_AUTOBOOT_DELAY_STR2
586 CONFIG_AUTOBOOT_STOP_STR2
587 CONFIG_ZERO_BOOTDELAY_CHECK
588 CONFIG_RESET_TO_RETRY
592 Only needed when CONFIG_BOOTDELAY is enabled;
593 define a command string that is automatically executed
594 when no character is read on the console interface
595 within "Boot Delay" after reset.
598 This can be used to pass arguments to the bootm
599 command. The value of CONFIG_BOOTARGS goes into the
600 environment value "bootargs".
602 CONFIG_RAMBOOT and CONFIG_NFSBOOT
603 The value of these goes into the environment as
604 "ramboot" and "nfsboot" respectively, and can be used
605 as a convenience, when switching between booting from
611 When this option is #defined, the existence of the
612 environment variable "preboot" will be checked
613 immediately before starting the CONFIG_BOOTDELAY
614 countdown and/or running the auto-boot command resp.
615 entering interactive mode.
617 This feature is especially useful when "preboot" is
618 automatically generated or modified. For an example
619 see the LWMON board specific code: here "preboot" is
620 modified when the user holds down a certain
621 combination of keys on the (special) keyboard when
624 - Serial Download Echo Mode:
626 If defined to 1, all characters received during a
627 serial download (using the "loads" command) are
628 echoed back. This might be needed by some terminal
629 emulations (like "cu"), but may as well just take
630 time on others. This setting #define's the initial
631 value of the "loads_echo" environment variable.
633 - Kgdb Serial Baudrate: (if CFG_CMD_KGDB is defined)
635 Select one of the baudrates listed in
636 CFG_BAUDRATE_TABLE, see below.
640 Most monitor functions can be selected (or
641 de-selected) by adjusting the definition of
642 CONFIG_COMMANDS; to select individual functions,
643 #define CONFIG_COMMANDS by "OR"ing any of the
646 #define enables commands:
647 -------------------------
648 CFG_CMD_ASKENV * ask for env variable
649 CFG_CMD_AUTOSCRIPT Autoscript Support
651 CFG_CMD_BEDBUG * Include BedBug Debugger
652 CFG_CMD_BMP * BMP support
653 CFG_CMD_BSP * Board specific commands
655 CFG_CMD_CACHE * icache, dcache
656 CFG_CMD_CONSOLE coninfo
657 CFG_CMD_DATE * support for RTC, date/time...
658 CFG_CMD_DHCP * DHCP support
659 CFG_CMD_DIAG * Diagnostics
660 CFG_CMD_DOC * Disk-On-Chip Support
661 CFG_CMD_DTT * Digital Therm and Thermostat
662 CFG_CMD_ECHO echo arguments
663 CFG_CMD_EEPROM * EEPROM read/write support
664 CFG_CMD_ELF * bootelf, bootvx
666 CFG_CMD_FDC * Floppy Disk Support
667 CFG_CMD_FAT * FAT partition support
668 CFG_CMD_FDOS * Dos diskette Support
669 CFG_CMD_FLASH flinfo, erase, protect
670 CFG_CMD_FPGA FPGA device initialization support
671 CFG_CMD_HWFLOW * RTS/CTS hw flow control
672 CFG_CMD_I2C * I2C serial bus support
673 CFG_CMD_IDE * IDE harddisk support
675 CFG_CMD_IMLS List all found images
676 CFG_CMD_IMMAP * IMMR dump support
677 CFG_CMD_IRQ * irqinfo
678 CFG_CMD_ITEST Integer/string test of 2 values
679 CFG_CMD_JFFS2 * JFFS2 Support
683 CFG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base,
685 CFG_CMD_MISC Misc functions like sleep etc
686 CFG_CMD_MMC * MMC memory mapped support
687 CFG_CMD_MII * MII utility commands
688 CFG_CMD_NAND * NAND support
689 CFG_CMD_NET bootp, tftpboot, rarpboot
690 CFG_CMD_PCI * pciinfo
691 CFG_CMD_PCMCIA * PCMCIA support
692 CFG_CMD_PING * send ICMP ECHO_REQUEST to network host
693 CFG_CMD_PORTIO * Port I/O
694 CFG_CMD_REGINFO * Register dump
695 CFG_CMD_RUN run command in env variable
696 CFG_CMD_SAVES * save S record dump
697 CFG_CMD_SCSI * SCSI Support
698 CFG_CMD_SDRAM * print SDRAM configuration information
699 (requires CFG_CMD_I2C)
700 CFG_CMD_SETGETDCR Support for DCR Register access (4xx only)
701 CFG_CMD_SPI * SPI serial bus support
702 CFG_CMD_USB * USB support
703 CFG_CMD_VFD * VFD support (TRAB)
704 CFG_CMD_BSP * Board SPecific functions
705 CFG_CMD_CDP * Cisco Discover Protocol support
706 -----------------------------------------------
709 CONFIG_CMD_DFL Default configuration; at the moment
710 this is includes all commands, except
711 the ones marked with "*" in the list
714 If you don't define CONFIG_COMMANDS it defaults to
715 CONFIG_CMD_DFL in include/cmd_confdefs.h. A board can
716 override the default settings in the respective
719 EXAMPLE: If you want all functions except of network
720 support you can write:
722 #define CONFIG_COMMANDS (CFG_CMD_ALL & ~CFG_CMD_NET)
725 Note: Don't enable the "icache" and "dcache" commands
726 (configuration option CFG_CMD_CACHE) unless you know
727 what you (and your U-Boot users) are doing. Data
728 cache cannot be enabled on systems like the 8xx or
729 8260 (where accesses to the IMMR region must be
730 uncached), and it cannot be disabled on all other
731 systems where we (mis-) use the data cache to hold an
732 initial stack and some data.
735 XXX - this list needs to get updated!
739 If this variable is defined, it enables watchdog
740 support. There must be support in the platform specific
741 code for a watchdog. For the 8xx and 8260 CPUs, the
742 SIU Watchdog feature is enabled in the SYPCR
746 CONFIG_VERSION_VARIABLE
747 If this variable is defined, an environment variable
748 named "ver" is created by U-Boot showing the U-Boot
749 version as printed by the "version" command.
750 This variable is readonly.
754 When CFG_CMD_DATE is selected, the type of the RTC
755 has to be selected, too. Define exactly one of the
758 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx
759 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC
760 CONFIG_RTC_MC146818 - use MC146818 RTC
761 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC
762 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC
763 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC
764 CONFIG_RTC_DS164x - use Dallas DS164x RTC
765 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC
767 Note that if the RTC uses I2C, then the I2C interface
768 must also be configured. See I2C Support, below.
772 When CONFIG_TIMESTAMP is selected, the timestamp
773 (date and time) of an image is printed by image
774 commands like bootm or iminfo. This option is
775 automatically enabled when you select CFG_CMD_DATE .
778 CONFIG_MAC_PARTITION and/or CONFIG_DOS_PARTITION
779 and/or CONFIG_ISO_PARTITION
781 If IDE or SCSI support is enabled (CFG_CMD_IDE or
782 CFG_CMD_SCSI) you must configure support for at least
783 one partition type as well.
786 CONFIG_IDE_RESET_ROUTINE - this is defined in several
787 board configurations files but used nowhere!
789 CONFIG_IDE_RESET - is this is defined, IDE Reset will
790 be performed by calling the function
791 ide_set_reset(int reset)
792 which has to be defined in a board specific file
797 Set this to enable ATAPI support.
802 Set this to enable support for disks larger than 137GB
803 Also look at CFG_64BIT_LBA ,CFG_64BIT_VSPRINTF and CFG_64BIT_STRTOUL
804 Whithout these , LBA48 support uses 32bit variables and will 'only'
805 support disks up to 2.1TB.
808 When enabled, makes the IDE subsystem use 64bit sector addresses.
812 At the moment only there is only support for the
813 SYM53C8XX SCSI controller; define
814 CONFIG_SCSI_SYM53C8XX to enable it.
816 CFG_SCSI_MAX_LUN [8], CFG_SCSI_MAX_SCSI_ID [7] and
817 CFG_SCSI_MAX_DEVICE [CFG_SCSI_MAX_SCSI_ID *
818 CFG_SCSI_MAX_LUN] can be adjusted to define the
819 maximum numbers of LUNs, SCSI ID's and target
821 CFG_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz)
823 - NETWORK Support (PCI):
825 Support for Intel 8254x gigabit chips.
828 Support for Intel 82557/82559/82559ER chips.
829 Optional CONFIG_EEPRO100_SROM_WRITE enables eeprom
830 write routine for first time initialisation.
833 Support for Digital 2114x chips.
834 Optional CONFIG_TULIP_SELECT_MEDIA for board specific
835 modem chip initialisation (KS8761/QS6611).
838 Support for National dp83815 chips.
841 Support for National dp8382[01] gigabit chips.
843 - NETWORK Support (other):
845 CONFIG_DRIVER_LAN91C96
846 Support for SMSC's LAN91C96 chips.
849 Define this to hold the physical address
850 of the LAN91C96's I/O space
852 CONFIG_LAN91C96_USE_32_BIT
853 Define this to enable 32 bit addressing
855 CONFIG_DRIVER_SMC91111
856 Support for SMSC's LAN91C111 chip
859 Define this to hold the physical address
860 of the device (I/O space)
862 CONFIG_SMC_USE_32_BIT
863 Define this if data bus is 32 bits
865 CONFIG_SMC_USE_IOFUNCS
866 Define this to use i/o functions instead of macros
867 (some hardware wont work with macros)
870 At the moment only the UHCI host controller is
871 supported (PIP405, MIP405, MPC5200); define
872 CONFIG_USB_UHCI to enable it.
873 define CONFIG_USB_KEYBOARD to enable the USB Keyboard
874 and define CONFIG_USB_STORAGE to enable the USB
877 Supported are USB Keyboards and USB Floppy drives
879 MPC5200 USB requires additional defines:
881 for 528 MHz Clock: 0x0001bbbb
883 for differential drivers: 0x00001000
884 for single ended drivers: 0x00005000
887 Define the below if you wish to use the USB console.
888 Once firmware is rebuilt from a serial console issue the
889 command "setenv stdin usbtty; setenv stdout usbtty" and
890 attach your usb cable. The Unix command "dmesg" should print
891 it has found a new device. The environment variable usbtty
892 can be set to gserial or cdc_acm to enable your device to
893 appear to a USB host as a Linux gserial device or a
894 Common Device Class Abstract Control Model serial device.
895 If you select usbtty = gserial you should be able to enumerate
897 # modprobe usbserial vendor=0xVendorID product=0xProductID
898 else if using cdc_acm, simply setting the environment
899 variable usbtty to be cdc_acm should suffice. The following
900 might be defined in YourBoardName.h
903 Define this to build a UDC device
906 Define this to have a tty type of device available to
907 talk to the UDC device
909 CFG_CONSOLE_IS_IN_ENV
910 Define this if you want stdin, stdout &/or stderr to
914 CFG_USB_EXTC_CLK 0xBLAH
915 Derive USB clock from external clock "blah"
916 - CFG_USB_EXTC_CLK 0x02
918 CFG_USB_BRG_CLK 0xBLAH
919 Derive USB clock from brgclk
920 - CFG_USB_BRG_CLK 0x04
922 If you have a USB-IF assigned VendorID then you may wish to
923 define your own vendor specific values either in BoardName.h
924 or directly in usbd_vendor_info.h. If you don't define
925 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME,
926 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot
927 should pretend to be a Linux device to it's target host.
929 CONFIG_USBD_MANUFACTURER
930 Define this string as the name of your company for
931 - CONFIG_USBD_MANUFACTURER "my company"
933 CONFIG_USBD_PRODUCT_NAME
934 Define this string as the name of your product
935 - CONFIG_USBD_PRODUCT_NAME "acme usb device"
938 Define this as your assigned Vendor ID from the USB
939 Implementors Forum. This *must* be a genuine Vendor ID
940 to avoid polluting the USB namespace.
941 - CONFIG_USBD_VENDORID 0xFFFF
943 CONFIG_USBD_PRODUCTID
944 Define this as the unique Product ID
946 - CONFIG_USBD_PRODUCTID 0xFFFF
950 The MMC controller on the Intel PXA is supported. To
951 enable this define CONFIG_MMC. The MMC can be
952 accessed from the boot prompt by mapping the device
953 to physical memory similar to flash. Command line is
954 enabled with CFG_CMD_MMC. The MMC driver also works with
955 the FAT fs. This is enabled with CFG_CMD_FAT.
957 - Journaling Flash filesystem support:
958 CONFIG_JFFS2_NAND, CONFIG_JFFS2_NAND_OFF, CONFIG_JFFS2_NAND_SIZE,
959 CONFIG_JFFS2_NAND_DEV
960 Define these for a default partition on a NAND device
962 CFG_JFFS2_FIRST_SECTOR,
963 CFG_JFFS2_FIRST_BANK, CFG_JFFS2_NUM_BANKS
964 Define these for a default partition on a NOR device
967 Define this to create an own partition. You have to provide a
968 function struct part_info* jffs2_part_info(int part_num)
970 If you define only one JFFS2 partition you may also want to
971 #define CFG_JFFS_SINGLE_PART 1
972 to disable the command chpart. This is the default when you
973 have not defined a custom partition
978 Define this to enable standard (PC-Style) keyboard
982 Standard PC keyboard driver with US (is default) and
983 GERMAN key layout (switch via environment 'keymap=de') support.
984 Export function i8042_kbd_init, i8042_tstc and i8042_getc
985 for cfb_console. Supports cursor blinking.
990 Define this to enable video support (for output to
995 Enable Chips & Technologies 69000 Video chip
997 CONFIG_VIDEO_SMI_LYNXEM
998 Enable Silicon Motion SMI 712/710/810 Video chip. The
999 video output is selected via environment 'videoout'
1000 (1 = LCD and 2 = CRT). If videoout is undefined, CRT is
1003 For the CT69000 and SMI_LYNXEM drivers, videomode is
1004 selected via environment 'videomode'. Two diferent ways
1006 - "videomode=num" 'num' is a standard LiLo mode numbers.
1007 Following standard modes are supported (* is default):
1009 Colors 640x480 800x600 1024x768 1152x864 1280x1024
1010 -------------+---------------------------------------------
1011 8 bits | 0x301* 0x303 0x305 0x161 0x307
1012 15 bits | 0x310 0x313 0x316 0x162 0x319
1013 16 bits | 0x311 0x314 0x317 0x163 0x31A
1014 24 bits | 0x312 0x315 0x318 ? 0x31B
1015 -------------+---------------------------------------------
1016 (i.e. setenv videomode 317; saveenv; reset;)
1018 - "videomode=bootargs" all the video parameters are parsed
1019 from the bootargs. (See drivers/videomodes.c)
1022 CONFIG_VIDEO_SED13806
1023 Enable Epson SED13806 driver. This driver supports 8bpp
1024 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP
1025 or CONFIG_VIDEO_SED13806_16BPP
1030 Define this to enable a custom keyboard support.
1031 This simply calls drv_keyboard_init() which must be
1032 defined in your board-specific files.
1033 The only board using this so far is RBC823.
1035 - LCD Support: CONFIG_LCD
1037 Define this to enable LCD support (for output to LCD
1038 display); also select one of the supported displays
1039 by defining one of these:
1041 CONFIG_NEC_NL6448AC33:
1043 NEC NL6448AC33-18. Active, color, single scan.
1045 CONFIG_NEC_NL6448BC20
1047 NEC NL6448BC20-08. 6.5", 640x480.
1048 Active, color, single scan.
1050 CONFIG_NEC_NL6448BC33_54
1052 NEC NL6448BC33-54. 10.4", 640x480.
1053 Active, color, single scan.
1057 Sharp 320x240. Active, color, single scan.
1058 It isn't 16x9, and I am not sure what it is.
1060 CONFIG_SHARP_LQ64D341
1062 Sharp LQ64D341 display, 640x480.
1063 Active, color, single scan.
1067 HLD1045 display, 640x480.
1068 Active, color, single scan.
1072 Optrex CBL50840-2 NF-FW 99 22 M5
1074 Hitachi LMG6912RPFC-00T
1078 320x240. Black & white.
1080 Normally display is black on white background; define
1081 CFG_WHITE_ON_BLACK to get it inverted.
1083 - Splash Screen Support: CONFIG_SPLASH_SCREEN
1085 If this option is set, the environment is checked for
1086 a variable "splashimage". If found, the usual display
1087 of logo, copyright and system information on the LCD
1088 is suppressed and the BMP image at the address
1089 specified in "splashimage" is loaded instead. The
1090 console is redirected to the "nulldev", too. This
1091 allows for a "silent" boot where a splash screen is
1092 loaded very quickly after power-on.
1094 - Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP
1096 If this option is set, additionally to standard BMP
1097 images, gzipped BMP images can be displayed via the
1098 splashscreen support or the bmp command.
1100 - Compression support:
1103 If this option is set, support for bzip2 compressed
1104 images is included. If not, only uncompressed and gzip
1105 compressed images are supported.
1107 NOTE: the bzip2 algorithm requires a lot of RAM, so
1108 the malloc area (as defined by CFG_MALLOC_LEN) should
1114 The address of PHY on MII bus.
1116 CONFIG_PHY_CLOCK_FREQ (ppc4xx)
1118 The clock frequency of the MII bus
1122 If this option is set, support for speed/duplex
1123 detection of Gigabit PHY is included.
1125 CONFIG_PHY_RESET_DELAY
1127 Some PHY like Intel LXT971A need extra delay after
1128 reset before any MII register access is possible.
1129 For such PHY, set this option to the usec delay
1130 required. (minimum 300usec for LXT971A)
1132 CONFIG_PHY_CMD_DELAY (ppc4xx)
1134 Some PHY like Intel LXT971A need extra delay after
1135 command issued before MII status register can be read
1142 Define a default value for ethernet address to use
1143 for the respective ethernet interface, in case this
1144 is not determined automatically.
1149 Define a default value for the IP address to use for
1150 the default ethernet interface, in case this is not
1151 determined through e.g. bootp.
1153 - Server IP address:
1156 Defines a default value for theIP address of a TFTP
1157 server to contact when using the "tftboot" command.
1159 - BOOTP Recovery Mode:
1160 CONFIG_BOOTP_RANDOM_DELAY
1162 If you have many targets in a network that try to
1163 boot using BOOTP, you may want to avoid that all
1164 systems send out BOOTP requests at precisely the same
1165 moment (which would happen for instance at recovery
1166 from a power failure, when all systems will try to
1167 boot, thus flooding the BOOTP server. Defining
1168 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
1169 inserted before sending out BOOTP requests. The
1170 following delays are insterted then:
1172 1st BOOTP request: delay 0 ... 1 sec
1173 2nd BOOTP request: delay 0 ... 2 sec
1174 3rd BOOTP request: delay 0 ... 4 sec
1176 BOOTP requests: delay 0 ... 8 sec
1178 - DHCP Advanced Options:
1181 You can fine tune the DHCP functionality by adding
1182 these flags to the CONFIG_BOOTP_MASK define:
1184 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS
1185 serverip from a DHCP server, it is possible that more
1186 than one DNS serverip is offered to the client.
1187 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS
1188 serverip will be stored in the additional environment
1189 variable "dnsip2". The first DNS serverip is always
1190 stored in the variable "dnsip", when CONFIG_BOOTP_DNS
1191 is added to the CONFIG_BOOTP_MASK.
1193 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable
1194 to do a dynamic update of a DNS server. To do this, they
1195 need the hostname of the DHCP requester.
1196 If CONFIG_BOOP_SEND_HOSTNAME is added to the
1197 CONFIG_BOOTP_MASK, the content of the "hostname"
1198 environment variable is passed as option 12 to
1202 CONFIG_CDP_DEVICE_ID
1204 The device id used in CDP trigger frames.
1206 CONFIG_CDP_DEVICE_ID_PREFIX
1208 A two character string which is prefixed to the MAC address
1213 A printf format string which contains the ascii name of
1214 the port. Normally is set to "eth%d" which sets
1215 eth0 for the first ethernet, eth1 for the second etc.
1217 CONFIG_CDP_CAPABILITIES
1219 A 32bit integer which indicates the device capabilities;
1220 0x00000010 for a normal host which does not forwards.
1224 An ascii string containing the version of the software.
1228 An ascii string containing the name of the platform.
1232 A 32bit integer sent on the trigger.
1234 CONFIG_CDP_POWER_CONSUMPTION
1236 A 16bit integer containing the power consumption of the
1237 device in .1 of milliwatts.
1239 CONFIG_CDP_APPLIANCE_VLAN_TYPE
1241 A byte containing the id of the VLAN.
1243 - Status LED: CONFIG_STATUS_LED
1245 Several configurations allow to display the current
1246 status using a LED. For instance, the LED will blink
1247 fast while running U-Boot code, stop blinking as
1248 soon as a reply to a BOOTP request was received, and
1249 start blinking slow once the Linux kernel is running
1250 (supported by a status LED driver in the Linux
1251 kernel). Defining CONFIG_STATUS_LED enables this
1254 - CAN Support: CONFIG_CAN_DRIVER
1256 Defining CONFIG_CAN_DRIVER enables CAN driver support
1257 on those systems that support this (optional)
1258 feature, like the TQM8xxL modules.
1260 - I2C Support: CONFIG_HARD_I2C | CONFIG_SOFT_I2C
1262 These enable I2C serial bus commands. Defining either of
1263 (but not both of) CONFIG_HARD_I2C or CONFIG_SOFT_I2C will
1264 include the appropriate I2C driver for the selected cpu.
1266 This will allow you to use i2c commands at the u-boot
1267 command line (as long as you set CFG_CMD_I2C in
1268 CONFIG_COMMANDS) and communicate with i2c based realtime
1269 clock chips. See common/cmd_i2c.c for a description of the
1270 command line interface.
1272 CONFIG_I2C_CMD_TREE is a recommended option that places
1273 all I2C commands under a single 'i2c' root command. The
1274 older 'imm', 'imd', 'iprobe' etc. commands are considered
1275 deprecated and may disappear in the future.
1277 CONFIG_HARD_I2C selects a hardware I2C controller.
1279 CONFIG_SOFT_I2C configures u-boot to use a software (aka
1280 bit-banging) driver instead of CPM or similar hardware
1283 There are several other quantities that must also be
1284 defined when you define CONFIG_HARD_I2C or CONFIG_SOFT_I2C.
1286 In both cases you will need to define CFG_I2C_SPEED
1287 to be the frequency (in Hz) at which you wish your i2c bus
1288 to run and CFG_I2C_SLAVE to be the address of this node (ie
1289 the cpu's i2c node address).
1291 Now, the u-boot i2c code for the mpc8xx (cpu/mpc8xx/i2c.c)
1292 sets the cpu up as a master node and so its address should
1293 therefore be cleared to 0 (See, eg, MPC823e User's Manual
1294 p.16-473). So, set CFG_I2C_SLAVE to 0.
1296 That's all that's required for CONFIG_HARD_I2C.
1298 If you use the software i2c interface (CONFIG_SOFT_I2C)
1299 then the following macros need to be defined (examples are
1300 from include/configs/lwmon.h):
1304 (Optional). Any commands necessary to enable the I2C
1305 controller or configure ports.
1307 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
1311 (Only for MPC8260 CPU). The I/O port to use (the code
1312 assumes both bits are on the same port). Valid values
1313 are 0..3 for ports A..D.
1317 The code necessary to make the I2C data line active
1318 (driven). If the data line is open collector, this
1321 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
1325 The code necessary to make the I2C data line tri-stated
1326 (inactive). If the data line is open collector, this
1329 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
1333 Code that returns TRUE if the I2C data line is high,
1336 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
1340 If <bit> is TRUE, sets the I2C data line high. If it
1341 is FALSE, it clears it (low).
1343 eg: #define I2C_SDA(bit) \
1344 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
1345 else immr->im_cpm.cp_pbdat &= ~PB_SDA
1349 If <bit> is TRUE, sets the I2C clock line high. If it
1350 is FALSE, it clears it (low).
1352 eg: #define I2C_SCL(bit) \
1353 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
1354 else immr->im_cpm.cp_pbdat &= ~PB_SCL
1358 This delay is invoked four times per clock cycle so this
1359 controls the rate of data transfer. The data rate thus
1360 is 1 / (I2C_DELAY * 4). Often defined to be something
1363 #define I2C_DELAY udelay(2)
1367 When a board is reset during an i2c bus transfer
1368 chips might think that the current transfer is still
1369 in progress. On some boards it is possible to access
1370 the i2c SCLK line directly, either by using the
1371 processor pin as a GPIO or by having a second pin
1372 connected to the bus. If this option is defined a
1373 custom i2c_init_board() routine in boards/xxx/board.c
1374 is run early in the boot sequence.
1376 CONFIG_I2CFAST (PPC405GP|PPC405EP only)
1378 This option enables configuration of bi_iic_fast[] flags
1379 in u-boot bd_info structure based on u-boot environment
1380 variable "i2cfast". (see also i2cfast)
1382 CONFIG_I2C_MULTI_BUS
1384 This option allows the use of multiple I2C buses, each of which
1385 must have a controller. At any point in time, only one bus is
1386 active. To switch to a different bus, use the 'i2c dev' command.
1387 Note that bus numbering is zero-based.
1391 This option specifies a list of I2C devices that will be skipped
1392 when the 'i2c probe' command is issued (or 'iprobe' using the legacy
1393 command). If CONFIG_I2C_MULTI_BUS is set, specify a list of bus-device
1394 pairs. Otherwise, specify a 1D array of device addresses
1397 #undef CONFIG_I2C_MULTI_BUS
1398 #define CFG_I2C_NOPROBES {0x50,0x68}
1400 will skip addresses 0x50 and 0x68 on a board with one I2C bus
1402 #define CONFIG_I2C_MULTI_BUS
1403 #define CFG_I2C_MULTI_NOPROBES {{0,0x50},{0,0x68},{1,0x54}}
1405 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1
1409 If defined, then this indicates the I2C bus number for DDR SPD.
1410 If not defined, then U-Boot assumes that SPD is on I2C bus 0.
1414 If defined, then this indicates the I2C bus number for the RTC.
1415 If not defined, then U-Boot assumes that RTC is on I2C bus 0.
1419 If defined, then this indicates the I2C bus number for the DTT.
1420 If not defined, then U-Boot assumes that DTT is on I2C bus 0.
1424 Define this option if you want to use Freescale's I2C driver in
1428 - SPI Support: CONFIG_SPI
1430 Enables SPI driver (so far only tested with
1431 SPI EEPROM, also an instance works with Crystal A/D and
1432 D/As on the SACSng board)
1436 Enables extended (16-bit) SPI EEPROM addressing.
1437 (symmetrical to CONFIG_I2C_X)
1441 Enables a software (bit-bang) SPI driver rather than
1442 using hardware support. This is a general purpose
1443 driver that only requires three general I/O port pins
1444 (two outputs, one input) to function. If this is
1445 defined, the board configuration must define several
1446 SPI configuration items (port pins to use, etc). For
1447 an example, see include/configs/sacsng.h.
1449 - FPGA Support: CONFIG_FPGA_COUNT
1451 Specify the number of FPGA devices to support.
1455 Used to specify the types of FPGA devices. For example,
1456 #define CONFIG_FPGA CFG_XILINX_VIRTEX2
1458 CFG_FPGA_PROG_FEEDBACK
1460 Enable printing of hash marks during FPGA configuration.
1464 Enable checks on FPGA configuration interface busy
1465 status by the configuration function. This option
1466 will require a board or device specific function to
1471 If defined, a function that provides delays in the FPGA
1472 configuration driver.
1474 CFG_FPGA_CHECK_CTRLC
1475 Allow Control-C to interrupt FPGA configuration
1477 CFG_FPGA_CHECK_ERROR
1479 Check for configuration errors during FPGA bitfile
1480 loading. For example, abort during Virtex II
1481 configuration if the INIT_B line goes low (which
1482 indicated a CRC error).
1486 Maximum time to wait for the INIT_B line to deassert
1487 after PROB_B has been deasserted during a Virtex II
1488 FPGA configuration sequence. The default time is 500
1493 Maximum time to wait for BUSY to deassert during
1494 Virtex II FPGA configuration. The default is 5 mS.
1496 CFG_FPGA_WAIT_CONFIG
1498 Time to wait after FPGA configuration. The default is
1501 - Configuration Management:
1504 If defined, this string will be added to the U-Boot
1505 version information (U_BOOT_VERSION)
1507 - Vendor Parameter Protection:
1509 U-Boot considers the values of the environment
1510 variables "serial#" (Board Serial Number) and
1511 "ethaddr" (Ethernet Address) to be parameters that
1512 are set once by the board vendor / manufacturer, and
1513 protects these variables from casual modification by
1514 the user. Once set, these variables are read-only,
1515 and write or delete attempts are rejected. You can
1516 change this behviour:
1518 If CONFIG_ENV_OVERWRITE is #defined in your config
1519 file, the write protection for vendor parameters is
1520 completely disabled. Anybody can change or delete
1523 Alternatively, if you #define _both_ CONFIG_ETHADDR
1524 _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
1525 ethernet address is installed in the environment,
1526 which can be changed exactly ONCE by the user. [The
1527 serial# is unaffected by this, i. e. it remains
1533 Define this variable to enable the reservation of
1534 "protected RAM", i. e. RAM which is not overwritten
1535 by U-Boot. Define CONFIG_PRAM to hold the number of
1536 kB you want to reserve for pRAM. You can overwrite
1537 this default value by defining an environment
1538 variable "pram" to the number of kB you want to
1539 reserve. Note that the board info structure will
1540 still show the full amount of RAM. If pRAM is
1541 reserved, a new environment variable "mem" will
1542 automatically be defined to hold the amount of
1543 remaining RAM in a form that can be passed as boot
1544 argument to Linux, for instance like that:
1546 setenv bootargs ... mem=\${mem}
1549 This way you can tell Linux not to use this memory,
1550 either, which results in a memory region that will
1551 not be affected by reboots.
1553 *WARNING* If your board configuration uses automatic
1554 detection of the RAM size, you must make sure that
1555 this memory test is non-destructive. So far, the
1556 following board configurations are known to be
1559 ETX094, IVMS8, IVML24, SPD8xx, TQM8xxL,
1560 HERMES, IP860, RPXlite, LWMON, LANTEC,
1561 PCU_E, FLAGADM, TQM8260
1566 Define this variable to stop the system in case of a
1567 fatal error, so that you have to reset it manually.
1568 This is probably NOT a good idea for an embedded
1569 system where you want to system to reboot
1570 automatically as fast as possible, but it may be
1571 useful during development since you can try to debug
1572 the conditions that lead to the situation.
1574 CONFIG_NET_RETRY_COUNT
1576 This variable defines the number of retries for
1577 network operations like ARP, RARP, TFTP, or BOOTP
1578 before giving up the operation. If not defined, a
1579 default value of 5 is used.
1581 - Command Interpreter:
1582 CONFIG_AUTO_COMPLETE
1584 Enable auto completion of commands using TAB.
1586 Note that this feature has NOT been implemented yet
1587 for the "hush" shell.
1592 Define this variable to enable the "hush" shell (from
1593 Busybox) as command line interpreter, thus enabling
1594 powerful command line syntax like
1595 if...then...else...fi conditionals or `&&' and '||'
1596 constructs ("shell scripts").
1598 If undefined, you get the old, much simpler behaviour
1599 with a somewhat smaller memory footprint.
1604 This defines the secondary prompt string, which is
1605 printed when the command interpreter needs more input
1606 to complete a command. Usually "> ".
1610 In the current implementation, the local variables
1611 space and global environment variables space are
1612 separated. Local variables are those you define by
1613 simply typing `name=value'. To access a local
1614 variable later on, you have write `$name' or
1615 `${name}'; to execute the contents of a variable
1616 directly type `$name' at the command prompt.
1618 Global environment variables are those you use
1619 setenv/printenv to work with. To run a command stored
1620 in such a variable, you need to use the run command,
1621 and you must not use the '$' sign to access them.
1623 To store commands and special characters in a
1624 variable, please use double quotation marks
1625 surrounding the whole text of the variable, instead
1626 of the backslashes before semicolons and special
1629 - Commandline Editing and History:
1630 CONFIG_CMDLINE_EDITING
1632 Enable editiong and History functions for interactive
1633 commandline input operations
1635 - Default Environment:
1636 CONFIG_EXTRA_ENV_SETTINGS
1638 Define this to contain any number of null terminated
1639 strings (variable = value pairs) that will be part of
1640 the default environment compiled into the boot image.
1642 For example, place something like this in your
1643 board's config file:
1645 #define CONFIG_EXTRA_ENV_SETTINGS \
1649 Warning: This method is based on knowledge about the
1650 internal format how the environment is stored by the
1651 U-Boot code. This is NOT an official, exported
1652 interface! Although it is unlikely that this format
1653 will change soon, there is no guarantee either.
1654 You better know what you are doing here.
1656 Note: overly (ab)use of the default environment is
1657 discouraged. Make sure to check other ways to preset
1658 the environment like the autoscript function or the
1661 - DataFlash Support:
1662 CONFIG_HAS_DATAFLASH
1664 Defining this option enables DataFlash features and
1665 allows to read/write in Dataflash via the standard
1668 - SystemACE Support:
1671 Adding this option adds support for Xilinx SystemACE
1672 chips attached via some sort of local bus. The address
1673 of the chip must alsh be defined in the
1674 CFG_SYSTEMACE_BASE macro. For example:
1676 #define CONFIG_SYSTEMACE
1677 #define CFG_SYSTEMACE_BASE 0xf0000000
1679 When SystemACE support is added, the "ace" device type
1680 becomes available to the fat commands, i.e. fatls.
1682 - TFTP Fixed UDP Port:
1685 If this is defined, the environment variable tftpsrcp
1686 is used to supply the TFTP UDP source port value.
1687 If tftpsrcp isn't defined, the normal pseudo-random port
1688 number generator is used.
1690 Also, the environment variable tftpdstp is used to supply
1691 the TFTP UDP destination port value. If tftpdstp isn't
1692 defined, the normal port 69 is used.
1694 The purpose for tftpsrcp is to allow a TFTP server to
1695 blindly start the TFTP transfer using the pre-configured
1696 target IP address and UDP port. This has the effect of
1697 "punching through" the (Windows XP) firewall, allowing
1698 the remainder of the TFTP transfer to proceed normally.
1699 A better solution is to properly configure the firewall,
1700 but sometimes that is not allowed.
1702 - Show boot progress:
1703 CONFIG_SHOW_BOOT_PROGRESS
1705 Defining this option allows to add some board-
1706 specific code (calling a user-provided function
1707 "show_boot_progress(int)") that enables you to show
1708 the system's boot progress on some display (for
1709 example, some LED's) on your board. At the moment,
1710 the following checkpoints are implemented:
1713 1 common/cmd_bootm.c before attempting to boot an image
1714 -1 common/cmd_bootm.c Image header has bad magic number
1715 2 common/cmd_bootm.c Image header has correct magic number
1716 -2 common/cmd_bootm.c Image header has bad checksum
1717 3 common/cmd_bootm.c Image header has correct checksum
1718 -3 common/cmd_bootm.c Image data has bad checksum
1719 4 common/cmd_bootm.c Image data has correct checksum
1720 -4 common/cmd_bootm.c Image is for unsupported architecture
1721 5 common/cmd_bootm.c Architecture check OK
1722 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi, standalone)
1723 6 common/cmd_bootm.c Image Type check OK
1724 -6 common/cmd_bootm.c gunzip uncompression error
1725 -7 common/cmd_bootm.c Unimplemented compression type
1726 7 common/cmd_bootm.c Uncompression OK
1727 -8 common/cmd_bootm.c Wrong Image Type (not kernel, multi, standalone)
1728 8 common/cmd_bootm.c Image Type check OK
1729 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX)
1730 9 common/cmd_bootm.c Start initial ramdisk verification
1731 -10 common/cmd_bootm.c Ramdisk header has bad magic number
1732 -11 common/cmd_bootm.c Ramdisk header has bad checksum
1733 10 common/cmd_bootm.c Ramdisk header is OK
1734 -12 common/cmd_bootm.c Ramdisk data has bad checksum
1735 11 common/cmd_bootm.c Ramdisk data has correct checksum
1736 12 common/cmd_bootm.c Ramdisk verification complete, start loading
1737 -13 common/cmd_bootm.c Wrong Image Type (not PPC Linux Ramdisk)
1738 13 common/cmd_bootm.c Start multifile image verification
1739 14 common/cmd_bootm.c No initial ramdisk, no multifile, continue.
1740 15 common/cmd_bootm.c All preparation done, transferring control to OS
1742 -30 lib_ppc/board.c Fatal error, hang the system
1743 -31 post/post.c POST test failed, detected by post_output_backlog()
1744 -32 post/post.c POST test failed, detected by post_run_single()
1746 -1 common/cmd_doc.c Bad usage of "doc" command
1747 -1 common/cmd_doc.c No boot device
1748 -1 common/cmd_doc.c Unknown Chip ID on boot device
1749 -1 common/cmd_doc.c Read Error on boot device
1750 -1 common/cmd_doc.c Image header has bad magic number
1752 -1 common/cmd_ide.c Bad usage of "ide" command
1753 -1 common/cmd_ide.c No boot device
1754 -1 common/cmd_ide.c Unknown boot device
1755 -1 common/cmd_ide.c Unknown partition table
1756 -1 common/cmd_ide.c Invalid partition type
1757 -1 common/cmd_ide.c Read Error on boot device
1758 -1 common/cmd_ide.c Image header has bad magic number
1760 -1 common/cmd_nand.c Bad usage of "nand" command
1761 -1 common/cmd_nand.c No boot device
1762 -1 common/cmd_nand.c Unknown Chip ID on boot device
1763 -1 common/cmd_nand.c Read Error on boot device
1764 -1 common/cmd_nand.c Image header has bad magic number
1766 -1 common/env_common.c Environment has a bad CRC, using default
1772 [so far only for SMDK2400 and TRAB boards]
1774 - Modem support endable:
1775 CONFIG_MODEM_SUPPORT
1777 - RTS/CTS Flow control enable:
1780 - Modem debug support:
1781 CONFIG_MODEM_SUPPORT_DEBUG
1783 Enables debugging stuff (char screen[1024], dbg())
1784 for modem support. Useful only with BDI2000.
1786 - Interrupt support (PPC):
1788 There are common interrupt_init() and timer_interrupt()
1789 for all PPC archs. interrupt_init() calls interrupt_init_cpu()
1790 for cpu specific initialization. interrupt_init_cpu()
1791 should set decrementer_count to appropriate value. If
1792 cpu resets decrementer automatically after interrupt
1793 (ppc4xx) it should set decrementer_count to zero.
1794 timer_interrupt() calls timer_interrupt_cpu() for cpu
1795 specific handling. If board has watchdog / status_led
1796 / other_activity_monitor it works automatically from
1797 general timer_interrupt().
1801 In the target system modem support is enabled when a
1802 specific key (key combination) is pressed during
1803 power-on. Otherwise U-Boot will boot normally
1804 (autoboot). The key_pressed() fuction is called from
1805 board_init(). Currently key_pressed() is a dummy
1806 function, returning 1 and thus enabling modem
1809 If there are no modem init strings in the
1810 environment, U-Boot proceed to autoboot; the
1811 previous output (banner, info printfs) will be
1814 See also: doc/README.Modem
1817 Configuration Settings:
1818 -----------------------
1820 - CFG_LONGHELP: Defined when you want long help messages included;
1821 undefine this when you're short of memory.
1823 - CFG_PROMPT: This is what U-Boot prints on the console to
1824 prompt for user input.
1826 - CFG_CBSIZE: Buffer size for input from the Console
1828 - CFG_PBSIZE: Buffer size for Console output
1830 - CFG_MAXARGS: max. Number of arguments accepted for monitor commands
1832 - CFG_BARGSIZE: Buffer size for Boot Arguments which are passed to
1833 the application (usually a Linux kernel) when it is
1836 - CFG_BAUDRATE_TABLE:
1837 List of legal baudrate settings for this board.
1839 - CFG_CONSOLE_INFO_QUIET
1840 Suppress display of console information at boot.
1842 - CFG_CONSOLE_IS_IN_ENV
1843 If the board specific function
1844 extern int overwrite_console (void);
1845 returns 1, the stdin, stderr and stdout are switched to the
1846 serial port, else the settings in the environment are used.
1848 - CFG_CONSOLE_OVERWRITE_ROUTINE
1849 Enable the call to overwrite_console().
1851 - CFG_CONSOLE_ENV_OVERWRITE
1852 Enable overwrite of previous console environment settings.
1854 - CFG_MEMTEST_START, CFG_MEMTEST_END:
1855 Begin and End addresses of the area used by the
1859 Enable an alternate, more extensive memory test.
1861 - CFG_MEMTEST_SCRATCH:
1862 Scratch address used by the alternate memory test
1863 You only need to set this if address zero isn't writeable
1865 - CFG_TFTP_LOADADDR:
1866 Default load address for network file downloads
1868 - CFG_LOADS_BAUD_CHANGE:
1869 Enable temporary baudrate change while serial download
1872 Physical start address of SDRAM. _Must_ be 0 here.
1875 Physical start address of Motherboard I/O (if using a
1879 Physical start address of Flash memory.
1882 Physical start address of boot monitor code (set by
1883 make config files to be same as the text base address
1884 (TEXT_BASE) used when linking) - same as
1885 CFG_FLASH_BASE when booting from flash.
1888 Size of memory reserved for monitor code, used to
1889 determine _at_compile_time_ (!) if the environment is
1890 embedded within the U-Boot image, or in a separate
1894 Size of DRAM reserved for malloc() use.
1897 Normally compressed uImages are limited to an
1898 uncompressed size of 8 MBytes. If this is not enough,
1899 you can define CFG_BOOTM_LEN in your board config file
1900 to adjust this setting to your needs.
1903 Maximum size of memory mapped by the startup code of
1904 the Linux kernel; all data that must be processed by
1905 the Linux kernel (bd_info, boot arguments, eventually
1906 initrd image) must be put below this limit.
1908 - CFG_MAX_FLASH_BANKS:
1909 Max number of Flash memory banks
1911 - CFG_MAX_FLASH_SECT:
1912 Max number of sectors on a Flash chip
1914 - CFG_FLASH_ERASE_TOUT:
1915 Timeout for Flash erase operations (in ms)
1917 - CFG_FLASH_WRITE_TOUT:
1918 Timeout for Flash write operations (in ms)
1920 - CFG_FLASH_LOCK_TOUT
1921 Timeout for Flash set sector lock bit operation (in ms)
1923 - CFG_FLASH_UNLOCK_TOUT
1924 Timeout for Flash clear lock bits operation (in ms)
1926 - CFG_FLASH_PROTECTION
1927 If defined, hardware flash sectors protection is used
1928 instead of U-Boot software protection.
1930 - CFG_DIRECT_FLASH_TFTP:
1932 Enable TFTP transfers directly to flash memory;
1933 without this option such a download has to be
1934 performed in two steps: (1) download to RAM, and (2)
1935 copy from RAM to flash.
1937 The two-step approach is usually more reliable, since
1938 you can check if the download worked before you erase
1939 the flash, but in some situations (when sytem RAM is
1940 too limited to allow for a tempory copy of the
1941 downloaded image) this option may be very useful.
1944 Define if the flash driver uses extra elements in the
1945 common flash structure for storing flash geometry.
1947 - CFG_FLASH_CFI_DRIVER
1948 This option also enables the building of the cfi_flash driver
1949 in the drivers directory
1951 - CFG_FLASH_QUIET_TEST
1952 If this option is defined, the common CFI flash doesn't
1953 print it's warning upon not recognized FLASH banks. This
1954 is useful, if some of the configured banks are only
1955 optionally available.
1957 - CFG_RX_ETH_BUFFER:
1958 Defines the number of ethernet receive buffers. On some
1959 ethernet controllers it is recommended to set this value
1960 to 8 or even higher (EEPRO100 or 405 EMAC), since all
1961 buffers can be full shortly after enabling the interface
1962 on high ethernet traffic.
1963 Defaults to 4 if not defined.
1965 The following definitions that deal with the placement and management
1966 of environment data (variable area); in general, we support the
1967 following configurations:
1969 - CFG_ENV_IS_IN_FLASH:
1971 Define this if the environment is in flash memory.
1973 a) The environment occupies one whole flash sector, which is
1974 "embedded" in the text segment with the U-Boot code. This
1975 happens usually with "bottom boot sector" or "top boot
1976 sector" type flash chips, which have several smaller
1977 sectors at the start or the end. For instance, such a
1978 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In
1979 such a case you would place the environment in one of the
1980 4 kB sectors - with U-Boot code before and after it. With
1981 "top boot sector" type flash chips, you would put the
1982 environment in one of the last sectors, leaving a gap
1983 between U-Boot and the environment.
1987 Offset of environment data (variable area) to the
1988 beginning of flash memory; for instance, with bottom boot
1989 type flash chips the second sector can be used: the offset
1990 for this sector is given here.
1992 CFG_ENV_OFFSET is used relative to CFG_FLASH_BASE.
1996 This is just another way to specify the start address of
1997 the flash sector containing the environment (instead of
2000 - CFG_ENV_SECT_SIZE:
2002 Size of the sector containing the environment.
2005 b) Sometimes flash chips have few, equal sized, BIG sectors.
2006 In such a case you don't want to spend a whole sector for
2011 If you use this in combination with CFG_ENV_IS_IN_FLASH
2012 and CFG_ENV_SECT_SIZE, you can specify to use only a part
2013 of this flash sector for the environment. This saves
2014 memory for the RAM copy of the environment.
2016 It may also save flash memory if you decide to use this
2017 when your environment is "embedded" within U-Boot code,
2018 since then the remainder of the flash sector could be used
2019 for U-Boot code. It should be pointed out that this is
2020 STRONGLY DISCOURAGED from a robustness point of view:
2021 updating the environment in flash makes it always
2022 necessary to erase the WHOLE sector. If something goes
2023 wrong before the contents has been restored from a copy in
2024 RAM, your target system will be dead.
2026 - CFG_ENV_ADDR_REDUND
2029 These settings describe a second storage area used to hold
2030 a redundand copy of the environment data, so that there is
2031 a valid backup copy in case there is a power failure during
2032 a "saveenv" operation.
2034 BE CAREFUL! Any changes to the flash layout, and some changes to the
2035 source code will make it necessary to adapt <board>/u-boot.lds*
2039 - CFG_ENV_IS_IN_NVRAM:
2041 Define this if you have some non-volatile memory device
2042 (NVRAM, battery buffered SRAM) which you want to use for the
2048 These two #defines are used to determin the memory area you
2049 want to use for environment. It is assumed that this memory
2050 can just be read and written to, without any special
2053 BE CAREFUL! The first access to the environment happens quite early
2054 in U-Boot initalization (when we try to get the setting of for the
2055 console baudrate). You *MUST* have mappend your NVRAM area then, or
2058 Please note that even with NVRAM we still use a copy of the
2059 environment in RAM: we could work on NVRAM directly, but we want to
2060 keep settings there always unmodified except somebody uses "saveenv"
2061 to save the current settings.
2064 - CFG_ENV_IS_IN_EEPROM:
2066 Use this if you have an EEPROM or similar serial access
2067 device and a driver for it.
2072 These two #defines specify the offset and size of the
2073 environment area within the total memory of your EEPROM.
2075 - CFG_I2C_EEPROM_ADDR:
2076 If defined, specified the chip address of the EEPROM device.
2077 The default address is zero.
2079 - CFG_EEPROM_PAGE_WRITE_BITS:
2080 If defined, the number of bits used to address bytes in a
2081 single page in the EEPROM device. A 64 byte page, for example
2082 would require six bits.
2084 - CFG_EEPROM_PAGE_WRITE_DELAY_MS:
2085 If defined, the number of milliseconds to delay between
2086 page writes. The default is zero milliseconds.
2088 - CFG_I2C_EEPROM_ADDR_LEN:
2089 The length in bytes of the EEPROM memory array address. Note
2090 that this is NOT the chip address length!
2092 - CFG_I2C_EEPROM_ADDR_OVERFLOW:
2093 EEPROM chips that implement "address overflow" are ones
2094 like Catalyst 24WC04/08/16 which has 9/10/11 bits of
2095 address and the extra bits end up in the "chip address" bit
2096 slots. This makes a 24WC08 (1Kbyte) chip look like four 256
2099 Note that we consider the length of the address field to
2100 still be one byte because the extra address bits are hidden
2101 in the chip address.
2104 The size in bytes of the EEPROM device.
2107 - CFG_ENV_IS_IN_DATAFLASH:
2109 Define this if you have a DataFlash memory device which you
2110 want to use for the environment.
2116 These three #defines specify the offset and size of the
2117 environment area within the total memory of your DataFlash placed
2118 at the specified address.
2120 - CFG_ENV_IS_IN_NAND:
2122 Define this if you have a NAND device which you want to use
2123 for the environment.
2128 These two #defines specify the offset and size of the environment
2129 area within the first NAND device.
2131 - CFG_ENV_OFFSET_REDUND
2133 This setting describes a second storage area of CFG_ENV_SIZE
2134 size used to hold a redundant copy of the environment data,
2135 so that there is a valid backup copy in case there is a
2136 power failure during a "saveenv" operation.
2138 Note: CFG_ENV_OFFSET and CFG_ENV_OFFSET_REDUND must be aligned
2139 to a block boundary, and CFG_ENV_SIZE must be a multiple of
2140 the NAND devices block size.
2142 - CFG_SPI_INIT_OFFSET
2144 Defines offset to the initial SPI buffer area in DPRAM. The
2145 area is used at an early stage (ROM part) if the environment
2146 is configured to reside in the SPI EEPROM: We need a 520 byte
2147 scratch DPRAM area. It is used between the two initialization
2148 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems
2149 to be a good choice since it makes it far enough from the
2150 start of the data area as well as from the stack pointer.
2152 Please note that the environment is read-only as long as the monitor
2153 has been relocated to RAM and a RAM copy of the environment has been
2154 created; also, when using EEPROM you will have to use getenv_r()
2155 until then to read environment variables.
2157 The environment is protected by a CRC32 checksum. Before the monitor
2158 is relocated into RAM, as a result of a bad CRC you will be working
2159 with the compiled-in default environment - *silently*!!! [This is
2160 necessary, because the first environment variable we need is the
2161 "baudrate" setting for the console - if we have a bad CRC, we don't
2162 have any device yet where we could complain.]
2164 Note: once the monitor has been relocated, then it will complain if
2165 the default environment is used; a new CRC is computed as soon as you
2166 use the "saveenv" command to store a valid environment.
2168 - CFG_FAULT_ECHO_LINK_DOWN:
2169 Echo the inverted Ethernet link state to the fault LED.
2171 Note: If this option is active, then CFG_FAULT_MII_ADDR
2172 also needs to be defined.
2174 - CFG_FAULT_MII_ADDR:
2175 MII address of the PHY to check for the Ethernet link state.
2177 - CFG_64BIT_VSPRINTF:
2178 Makes vsprintf (and all *printf functions) support printing
2179 of 64bit values by using the L quantifier
2181 - CFG_64BIT_STRTOUL:
2182 Adds simple_strtoull that returns a 64bit value
2184 Low Level (hardware related) configuration options:
2185 ---------------------------------------------------
2187 - CFG_CACHELINE_SIZE:
2188 Cache Line Size of the CPU.
2191 Default address of the IMMR after system reset.
2193 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU,
2194 and RPXsuper) to be able to adjust the position of
2195 the IMMR register after a reset.
2197 - Floppy Disk Support:
2198 CFG_FDC_DRIVE_NUMBER
2200 the default drive number (default value 0)
2204 defines the spacing between fdc chipset registers
2209 defines the offset of register from address. It
2210 depends on which part of the data bus is connected to
2211 the fdc chipset. (default value 0)
2213 If CFG_ISA_IO_STRIDE CFG_ISA_IO_OFFSET and
2214 CFG_FDC_DRIVE_NUMBER are undefined, they take their
2217 if CFG_FDC_HW_INIT is defined, then the function
2218 fdc_hw_init() is called at the beginning of the FDC
2219 setup. fdc_hw_init() must be provided by the board
2220 source code. It is used to make hardware dependant
2223 - CFG_IMMR: Physical address of the Internal Memory.
2224 DO NOT CHANGE unless you know exactly what you're
2225 doing! (11-4) [MPC8xx/82xx systems only]
2227 - CFG_INIT_RAM_ADDR:
2229 Start address of memory area that can be used for
2230 initial data and stack; please note that this must be
2231 writable memory that is working WITHOUT special
2232 initialization, i. e. you CANNOT use normal RAM which
2233 will become available only after programming the
2234 memory controller and running certain initialization
2237 U-Boot uses the following memory types:
2238 - MPC8xx and MPC8260: IMMR (internal memory of the CPU)
2239 - MPC824X: data cache
2240 - PPC4xx: data cache
2242 - CFG_GBL_DATA_OFFSET:
2244 Offset of the initial data structure in the memory
2245 area defined by CFG_INIT_RAM_ADDR. Usually
2246 CFG_GBL_DATA_OFFSET is chosen such that the initial
2247 data is located at the end of the available space
2248 (sometimes written as (CFG_INIT_RAM_END -
2249 CFG_INIT_DATA_SIZE), and the initial stack is just
2250 below that area (growing from (CFG_INIT_RAM_ADDR +
2251 CFG_GBL_DATA_OFFSET) downward.
2254 On the MPC824X (or other systems that use the data
2255 cache for initial memory) the address chosen for
2256 CFG_INIT_RAM_ADDR is basically arbitrary - it must
2257 point to an otherwise UNUSED address space between
2258 the top of RAM and the start of the PCI space.
2260 - CFG_SIUMCR: SIU Module Configuration (11-6)
2262 - CFG_SYPCR: System Protection Control (11-9)
2264 - CFG_TBSCR: Time Base Status and Control (11-26)
2266 - CFG_PISCR: Periodic Interrupt Status and Control (11-31)
2268 - CFG_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30)
2270 - CFG_SCCR: System Clock and reset Control Register (15-27)
2272 - CFG_OR_TIMING_SDRAM:
2276 periodic timer for refresh
2278 - CFG_DER: Debug Event Register (37-47)
2280 - FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CFG_REMAP_OR_AM,
2281 CFG_PRELIM_OR_AM, CFG_OR_TIMING_FLASH, CFG_OR0_REMAP,
2282 CFG_OR0_PRELIM, CFG_BR0_PRELIM, CFG_OR1_REMAP, CFG_OR1_PRELIM,
2284 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
2286 - SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
2287 CFG_OR_TIMING_SDRAM, CFG_OR2_PRELIM, CFG_BR2_PRELIM,
2288 CFG_OR3_PRELIM, CFG_BR3_PRELIM:
2289 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
2291 - CFG_MAMR_PTA, CFG_MPTPR_2BK_4K, CFG_MPTPR_1BK_4K, CFG_MPTPR_2BK_8K,
2292 CFG_MPTPR_1BK_8K, CFG_MAMR_8COL, CFG_MAMR_9COL:
2293 Machine Mode Register and Memory Periodic Timer
2294 Prescaler definitions (SDRAM timing)
2296 - CFG_I2C_UCODE_PATCH, CFG_I2C_DPMEM_OFFSET [0x1FC0]:
2297 enable I2C microcode relocation patch (MPC8xx);
2298 define relocation offset in DPRAM [DSP2]
2300 - CFG_SPI_UCODE_PATCH, CFG_SPI_DPMEM_OFFSET [0x1FC0]:
2301 enable SPI microcode relocation patch (MPC8xx);
2302 define relocation offset in DPRAM [SCC4]
2305 Use OSCM clock mode on MBX8xx board. Be careful,
2306 wrong setting might damage your board. Read
2307 doc/README.MBX before setting this variable!
2309 - CFG_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only)
2310 Offset of the bootmode word in DPRAM used by post
2311 (Power On Self Tests). This definition overrides
2312 #define'd default value in commproc.h resp.
2315 - CFG_PCI_SLV_MEM_LOCAL, CFG_PCI_SLV_MEM_BUS, CFG_PICMR0_MASK_ATTRIB,
2316 CFG_PCI_MSTR0_LOCAL, CFG_PCIMSK0_MASK, CFG_PCI_MSTR1_LOCAL,
2317 CFG_PCIMSK1_MASK, CFG_PCI_MSTR_MEM_LOCAL, CFG_PCI_MSTR_MEM_BUS,
2318 CFG_CPU_PCI_MEM_START, CFG_PCI_MSTR_MEM_SIZE, CFG_POCMR0_MASK_ATTRIB,
2319 CFG_PCI_MSTR_MEMIO_LOCAL, CFG_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START,
2320 CFG_PCI_MSTR_MEMIO_SIZE, CFG_POCMR1_MASK_ATTRIB, CFG_PCI_MSTR_IO_LOCAL,
2321 CFG_PCI_MSTR_IO_BUS, CFG_CPU_PCI_IO_START, CFG_PCI_MSTR_IO_SIZE,
2322 CFG_POCMR2_MASK_ATTRIB: (MPC826x only)
2323 Overrides the default PCI memory map in cpu/mpc8260/pci.c if set.
2326 Get DDR timing information from an I2C EEPROM. Common with pluggable
2327 memory modules such as SODIMMs
2329 I2C address of the SPD EEPROM
2332 If SPD EEPROM is on an I2C bus other than the first one, specify here.
2333 Note that the value must resolve to something your driver can deal with.
2335 - CFG_83XX_DDR_USES_CS0
2336 Only for 83xx systems. If specified, then DDR should be configured
2337 using CS0 and CS1 instead of CS2 and CS3.
2339 - CFG_83XX_DDR_USES_CS0
2340 Only for 83xx systems. If specified, then DDR should be configured
2341 using CS0 and CS1 instead of CS2 and CS3.
2343 - CONFIG_ETHER_ON_FEC[12]
2344 Define to enable FEC[12] on a 8xx series processor.
2346 - CONFIG_FEC[12]_PHY
2347 Define to the hardcoded PHY address which corresponds
2348 to the given FEC; i. e.
2349 #define CONFIG_FEC1_PHY 4
2350 means that the PHY with address 4 is connected to FEC1
2352 When set to -1, means to probe for first available.
2354 - CONFIG_FEC[12]_PHY_NORXERR
2355 The PHY does not have a RXERR line (RMII only).
2356 (so program the FEC to ignore it).
2359 Enable RMII mode for all FECs.
2360 Note that this is a global option, we can't
2361 have one FEC in standard MII mode and another in RMII mode.
2363 - CONFIG_CRC32_VERIFY
2364 Add a verify option to the crc32 command.
2367 => crc32 -v <address> <count> <crc32>
2369 Where address/count indicate a memory area
2370 and crc32 is the correct crc32 which the
2374 Add the "loopw" memory command. This only takes effect if
2375 the memory commands are activated globally (CFG_CMD_MEM).
2378 Add the "mdc" and "mwc" memory commands. These are cyclic
2383 This command will print 4 bytes (10,11,12,13) each 500 ms.
2385 => mwc.l 100 12345678 10
2386 This command will write 12345678 to address 100 all 10 ms.
2388 This only takes effect if the memory commands are activated
2389 globally (CFG_CMD_MEM).
2391 - CONFIG_SKIP_LOWLEVEL_INIT
2392 - CONFIG_SKIP_RELOCATE_UBOOT
2394 [ARM only] If these variables are defined, then
2395 certain low level initializations (like setting up
2396 the memory controller) are omitted and/or U-Boot does
2397 not relocate itself into RAM.
2398 Normally these variables MUST NOT be defined. The
2399 only exception is when U-Boot is loaded (to RAM) by
2400 some other boot loader or by a debugger which
2401 performs these intializations itself.
2404 Building the Software:
2405 ======================
2407 Building U-Boot has been tested in native PPC environments (on a
2408 PowerBook G3 running LinuxPPC 2000) and in cross environments
2409 (running RedHat 6.x and 7.x Linux on x86, Solaris 2.6 on a SPARC, and
2412 If you are not using a native PPC environment, it is assumed that you
2413 have the GNU cross compiling tools available in your path and named
2414 with a prefix of "powerpc-linux-". If this is not the case, (e.g. if
2415 you are using Monta Vista's Hard Hat Linux CDK 1.2) you must change
2416 the definition of CROSS_COMPILE in Makefile. For HHL on a 4xx CPU,
2419 CROSS_COMPILE = ppc_4xx-
2422 U-Boot is intended to be simple to build. After installing the
2423 sources you must configure U-Boot for one specific board type. This
2428 where "NAME_config" is the name of one of the existing
2429 configurations; the following names are supported:
2431 ADCIOP_config FPS860L_config omap730p2_config
2432 ADS860_config GEN860T_config pcu_e_config
2434 AR405_config GENIETV_config PIP405_config
2435 at91rm9200dk_config GTH_config QS823_config
2436 CANBT_config hermes_config QS850_config
2437 cmi_mpc5xx_config hymod_config QS860T_config
2438 cogent_common_config IP860_config RPXlite_config
2439 cogent_mpc8260_config IVML24_config RPXlite_DW_config
2440 cogent_mpc8xx_config IVMS8_config RPXsuper_config
2441 CPCI405_config JSE_config rsdproto_config
2442 CPCIISER4_config LANTEC_config Sandpoint8240_config
2443 csb272_config lwmon_config sbc8260_config
2444 CU824_config MBX860T_config sbc8560_33_config
2445 DUET_ADS_config MBX_config sbc8560_66_config
2446 EBONY_config MPC8260ADS_config SM850_config
2447 ELPT860_config MPC8540ADS_config SPD823TS_config
2448 ESTEEM192E_config MPC8540EVAL_config stxgp3_config
2449 ETX094_config MPC8560ADS_config SXNI855T_config
2450 FADS823_config NETVIA_config TQM823L_config
2451 FADS850SAR_config omap1510inn_config TQM850L_config
2452 FADS860T_config omap1610h2_config TQM855L_config
2453 FPS850L_config omap1610inn_config TQM860L_config
2454 omap5912osk_config walnut_config
2455 omap2420h4_config Yukon8220_config
2458 Note: for some board special configuration names may exist; check if
2459 additional information is available from the board vendor; for
2460 instance, the TQM823L systems are available without (standard)
2461 or with LCD support. You can select such additional "features"
2462 when chosing the configuration, i. e.
2465 - will configure for a plain TQM823L, i. e. no LCD support
2467 make TQM823L_LCD_config
2468 - will configure for a TQM823L with U-Boot console on LCD
2473 Finally, type "make all", and you should get some working U-Boot
2474 images ready for download to / installation on your system:
2476 - "u-boot.bin" is a raw binary image
2477 - "u-boot" is an image in ELF binary format
2478 - "u-boot.srec" is in Motorola S-Record format
2480 By default the build is performed locally and the objects are saved
2481 in the source directory. One of the two methods can be used to change
2482 this behavior and build U-Boot to some external directory:
2484 1. Add O= to the make command line invocations:
2486 make O=/tmp/build distclean
2487 make O=/tmp/build NAME_config
2488 make O=/tmp/build all
2490 2. Set environment variable BUILD_DIR to point to the desired location:
2492 export BUILD_DIR=/tmp/build
2497 Note that the command line "O=" setting overrides the BUILD_DIR environment
2501 Please be aware that the Makefiles assume you are using GNU make, so
2502 for instance on NetBSD you might need to use "gmake" instead of
2506 If the system board that you have is not listed, then you will need
2507 to port U-Boot to your hardware platform. To do this, follow these
2510 1. Add a new configuration option for your board to the toplevel
2511 "Makefile" and to the "MAKEALL" script, using the existing
2512 entries as examples. Note that here and at many other places
2513 boards and other names are listed in alphabetical sort order. Please
2515 2. Create a new directory to hold your board specific code. Add any
2516 files you need. In your board directory, you will need at least
2517 the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds".
2518 3. Create a new configuration file "include/configs/<board>.h" for
2520 3. If you're porting U-Boot to a new CPU, then also create a new
2521 directory to hold your CPU specific code. Add any files you need.
2522 4. Run "make <board>_config" with your new name.
2523 5. Type "make", and you should get a working "u-boot.srec" file
2524 to be installed on your target system.
2525 6. Debug and solve any problems that might arise.
2526 [Of course, this last step is much harder than it sounds.]
2529 Testing of U-Boot Modifications, Ports to New Hardware, etc.:
2530 ==============================================================
2532 If you have modified U-Boot sources (for instance added a new board
2533 or support for new devices, a new CPU, etc.) you are expected to
2534 provide feedback to the other developers. The feedback normally takes
2535 the form of a "patch", i. e. a context diff against a certain (latest
2536 official or latest in CVS) version of U-Boot sources.
2538 But before you submit such a patch, please verify that your modifi-
2539 cation did not break existing code. At least make sure that *ALL* of
2540 the supported boards compile WITHOUT ANY compiler warnings. To do so,
2541 just run the "MAKEALL" script, which will configure and build U-Boot
2542 for ALL supported system. Be warned, this will take a while. You can
2543 select which (cross) compiler to use by passing a `CROSS_COMPILE'
2544 environment variable to the script, i. e. to use the cross tools from
2545 MontaVista's Hard Hat Linux you can type
2547 CROSS_COMPILE=ppc_8xx- MAKEALL
2549 or to build on a native PowerPC system you can type
2551 CROSS_COMPILE=' ' MAKEALL
2553 When using the MAKEALL script, the default behaviour is to build U-Boot
2554 in the source directory. This location can be changed by setting the
2555 BUILD_DIR environment variable. Also, for each target built, the MAKEALL
2556 script saves two log files (<target>.ERR and <target>.MAKEALL) in the
2557 <source dir>/LOG directory. This default location can be changed by
2558 setting the MAKEALL_LOGDIR environment variable. For example:
2560 export BUILD_DIR=/tmp/build
2561 export MAKEALL_LOGDIR=/tmp/log
2562 CROSS_COMPILE=ppc_8xx- MAKEALL
2564 With the above settings build objects are saved in the /tmp/build, log
2565 files are saved in the /tmp/log and the source tree remains clean during
2566 the whole build process.
2569 See also "U-Boot Porting Guide" below.
2572 Monitor Commands - Overview:
2573 ============================
2575 go - start application at address 'addr'
2576 run - run commands in an environment variable
2577 bootm - boot application image from memory
2578 bootp - boot image via network using BootP/TFTP protocol
2579 tftpboot- boot image via network using TFTP protocol
2580 and env variables "ipaddr" and "serverip"
2581 (and eventually "gatewayip")
2582 rarpboot- boot image via network using RARP/TFTP protocol
2583 diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
2584 loads - load S-Record file over serial line
2585 loadb - load binary file over serial line (kermit mode)
2587 mm - memory modify (auto-incrementing)
2588 nm - memory modify (constant address)
2589 mw - memory write (fill)
2591 cmp - memory compare
2592 crc32 - checksum calculation
2593 imd - i2c memory display
2594 imm - i2c memory modify (auto-incrementing)
2595 inm - i2c memory modify (constant address)
2596 imw - i2c memory write (fill)
2597 icrc32 - i2c checksum calculation
2598 iprobe - probe to discover valid I2C chip addresses
2599 iloop - infinite loop on address range
2600 isdram - print SDRAM configuration information
2601 sspi - SPI utility commands
2602 base - print or set address offset
2603 printenv- print environment variables
2604 setenv - set environment variables
2605 saveenv - save environment variables to persistent storage
2606 protect - enable or disable FLASH write protection
2607 erase - erase FLASH memory
2608 flinfo - print FLASH memory information
2609 bdinfo - print Board Info structure
2610 iminfo - print header information for application image
2611 coninfo - print console devices and informations
2612 ide - IDE sub-system
2613 loop - infinite loop on address range
2614 loopw - infinite write loop on address range
2615 mtest - simple RAM test
2616 icache - enable or disable instruction cache
2617 dcache - enable or disable data cache
2618 reset - Perform RESET of the CPU
2619 echo - echo args to console
2620 version - print monitor version
2621 help - print online help
2622 ? - alias for 'help'
2625 Monitor Commands - Detailed Description:
2626 ========================================
2630 For now: just type "help <command>".
2633 Environment Variables:
2634 ======================
2636 U-Boot supports user configuration using Environment Variables which
2637 can be made persistent by saving to Flash memory.
2639 Environment Variables are set using "setenv", printed using
2640 "printenv", and saved to Flash using "saveenv". Using "setenv"
2641 without a value can be used to delete a variable from the
2642 environment. As long as you don't save the environment you are
2643 working with an in-memory copy. In case the Flash area containing the
2644 environment is erased by accident, a default environment is provided.
2646 Some configuration options can be set using Environment Variables:
2648 baudrate - see CONFIG_BAUDRATE
2650 bootdelay - see CONFIG_BOOTDELAY
2652 bootcmd - see CONFIG_BOOTCOMMAND
2654 bootargs - Boot arguments when booting an RTOS image
2656 bootfile - Name of the image to load with TFTP
2658 autoload - if set to "no" (any string beginning with 'n'),
2659 "bootp" will just load perform a lookup of the
2660 configuration from the BOOTP server, but not try to
2661 load any image using TFTP
2663 autostart - if set to "yes", an image loaded using the "bootp",
2664 "rarpboot", "tftpboot" or "diskboot" commands will
2665 be automatically started (by internally calling
2668 If set to "no", a standalone image passed to the
2669 "bootm" command will be copied to the load address
2670 (and eventually uncompressed), but NOT be started.
2671 This can be used to load and uncompress arbitrary
2674 i2cfast - (PPC405GP|PPC405EP only)
2675 if set to 'y' configures Linux I2C driver for fast
2676 mode (400kHZ). This environment variable is used in
2677 initialization code. So, for changes to be effective
2678 it must be saved and board must be reset.
2680 initrd_high - restrict positioning of initrd images:
2681 If this variable is not set, initrd images will be
2682 copied to the highest possible address in RAM; this
2683 is usually what you want since it allows for
2684 maximum initrd size. If for some reason you want to
2685 make sure that the initrd image is loaded below the
2686 CFG_BOOTMAPSZ limit, you can set this environment
2687 variable to a value of "no" or "off" or "0".
2688 Alternatively, you can set it to a maximum upper
2689 address to use (U-Boot will still check that it
2690 does not overwrite the U-Boot stack and data).
2692 For instance, when you have a system with 16 MB
2693 RAM, and want to reserve 4 MB from use by Linux,
2694 you can do this by adding "mem=12M" to the value of
2695 the "bootargs" variable. However, now you must make
2696 sure that the initrd image is placed in the first
2697 12 MB as well - this can be done with
2699 setenv initrd_high 00c00000
2701 If you set initrd_high to 0xFFFFFFFF, this is an
2702 indication to U-Boot that all addresses are legal
2703 for the Linux kernel, including addresses in flash
2704 memory. In this case U-Boot will NOT COPY the
2705 ramdisk at all. This may be useful to reduce the
2706 boot time on your system, but requires that this
2707 feature is supported by your Linux kernel.
2709 ipaddr - IP address; needed for tftpboot command
2711 loadaddr - Default load address for commands like "bootp",
2712 "rarpboot", "tftpboot", "loadb" or "diskboot"
2714 loads_echo - see CONFIG_LOADS_ECHO
2716 serverip - TFTP server IP address; needed for tftpboot command
2718 bootretry - see CONFIG_BOOT_RETRY_TIME
2720 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
2722 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
2724 ethprime - When CONFIG_NET_MULTI is enabled controls which
2725 interface is used first.
2727 ethact - When CONFIG_NET_MULTI is enabled controls which
2728 interface is currently active. For example you
2729 can do the following
2731 => setenv ethact FEC ETHERNET
2732 => ping 192.168.0.1 # traffic sent on FEC ETHERNET
2733 => setenv ethact SCC ETHERNET
2734 => ping 10.0.0.1 # traffic sent on SCC ETHERNET
2736 netretry - When set to "no" each network operation will
2737 either succeed or fail without retrying.
2738 When set to "once" the network operation will
2739 fail when all the available network interfaces
2740 are tried once without success.
2741 Useful on scripts which control the retry operation
2744 tftpsrcport - If this is set, the value is used for TFTP's
2747 tftpdstport - If this is set, the value is used for TFTP's UDP
2748 destination port instead of the Well Know Port 69.
2750 vlan - When set to a value < 4095 the traffic over
2751 ethernet is encapsulated/received over 802.1q
2754 The following environment variables may be used and automatically
2755 updated by the network boot commands ("bootp" and "rarpboot"),
2756 depending the information provided by your boot server:
2758 bootfile - see above
2759 dnsip - IP address of your Domain Name Server
2760 dnsip2 - IP address of your secondary Domain Name Server
2761 gatewayip - IP address of the Gateway (Router) to use
2762 hostname - Target hostname
2764 netmask - Subnet Mask
2765 rootpath - Pathname of the root filesystem on the NFS server
2766 serverip - see above
2769 There are two special Environment Variables:
2771 serial# - contains hardware identification information such
2772 as type string and/or serial number
2773 ethaddr - Ethernet address
2775 These variables can be set only once (usually during manufacturing of
2776 the board). U-Boot refuses to delete or overwrite these variables
2777 once they have been set once.
2780 Further special Environment Variables:
2782 ver - Contains the U-Boot version string as printed
2783 with the "version" command. This variable is
2784 readonly (see CONFIG_VERSION_VARIABLE).
2787 Please note that changes to some configuration parameters may take
2788 only effect after the next boot (yes, that's just like Windoze :-).
2791 Command Line Parsing:
2792 =====================
2794 There are two different command line parsers available with U-Boot:
2795 the old "simple" one, and the much more powerful "hush" shell:
2797 Old, simple command line parser:
2798 --------------------------------
2800 - supports environment variables (through setenv / saveenv commands)
2801 - several commands on one line, separated by ';'
2802 - variable substitution using "... ${name} ..." syntax
2803 - special characters ('$', ';') can be escaped by prefixing with '\',
2805 setenv bootcmd bootm \${address}
2806 - You can also escape text by enclosing in single apostrophes, for example:
2807 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
2812 - similar to Bourne shell, with control structures like
2813 if...then...else...fi, for...do...done; while...do...done,
2814 until...do...done, ...
2815 - supports environment ("global") variables (through setenv / saveenv
2816 commands) and local shell variables (through standard shell syntax
2817 "name=value"); only environment variables can be used with "run"
2823 (1) If a command line (or an environment variable executed by a "run"
2824 command) contains several commands separated by semicolon, and
2825 one of these commands fails, then the remaining commands will be
2828 (2) If you execute several variables with one call to run (i. e.
2829 calling run with a list af variables as arguments), any failing
2830 command will cause "run" to terminate, i. e. the remaining
2831 variables are not executed.
2833 Note for Redundant Ethernet Interfaces:
2834 =======================================
2836 Some boards come with redundant ethernet interfaces; U-Boot supports
2837 such configurations and is capable of automatic selection of a
2838 "working" interface when needed. MAC assignment works as follows:
2840 Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
2841 MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
2842 "eth1addr" (=>eth1), "eth2addr", ...
2844 If the network interface stores some valid MAC address (for instance
2845 in SROM), this is used as default address if there is NO correspon-
2846 ding setting in the environment; if the corresponding environment
2847 variable is set, this overrides the settings in the card; that means:
2849 o If the SROM has a valid MAC address, and there is no address in the
2850 environment, the SROM's address is used.
2852 o If there is no valid address in the SROM, and a definition in the
2853 environment exists, then the value from the environment variable is
2856 o If both the SROM and the environment contain a MAC address, and
2857 both addresses are the same, this MAC address is used.
2859 o If both the SROM and the environment contain a MAC address, and the
2860 addresses differ, the value from the environment is used and a
2863 o If neither SROM nor the environment contain a MAC address, an error
2870 The "boot" commands of this monitor operate on "image" files which
2871 can be basicly anything, preceeded by a special header; see the
2872 definitions in include/image.h for details; basicly, the header
2873 defines the following image properties:
2875 * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
2876 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
2877 LynxOS, pSOS, QNX, RTEMS, ARTOS;
2878 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, ARTOS, LynxOS).
2879 * Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86,
2880 IA64, MIPS, NIOS, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
2881 Currently supported: ARM, AVR32, Intel x86, MIPS, NIOS, PowerPC).
2882 * Compression Type (uncompressed, gzip, bzip2)
2888 The header is marked by a special Magic Number, and both the header
2889 and the data portions of the image are secured against corruption by
2896 Although U-Boot should support any OS or standalone application
2897 easily, the main focus has always been on Linux during the design of
2900 U-Boot includes many features that so far have been part of some
2901 special "boot loader" code within the Linux kernel. Also, any
2902 "initrd" images to be used are no longer part of one big Linux image;
2903 instead, kernel and "initrd" are separate images. This implementation
2904 serves several purposes:
2906 - the same features can be used for other OS or standalone
2907 applications (for instance: using compressed images to reduce the
2908 Flash memory footprint)
2910 - it becomes much easier to port new Linux kernel versions because
2911 lots of low-level, hardware dependent stuff are done by U-Boot
2913 - the same Linux kernel image can now be used with different "initrd"
2914 images; of course this also means that different kernel images can
2915 be run with the same "initrd". This makes testing easier (you don't
2916 have to build a new "zImage.initrd" Linux image when you just
2917 change a file in your "initrd"). Also, a field-upgrade of the
2918 software is easier now.
2924 Porting Linux to U-Boot based systems:
2925 ---------------------------------------
2927 U-Boot cannot save you from doing all the necessary modifications to
2928 configure the Linux device drivers for use with your target hardware
2929 (no, we don't intend to provide a full virtual machine interface to
2932 But now you can ignore ALL boot loader code (in arch/ppc/mbxboot).
2934 Just make sure your machine specific header file (for instance
2935 include/asm-ppc/tqm8xx.h) includes the same definition of the Board
2936 Information structure as we define in include/u-boot.h, and make
2937 sure that your definition of IMAP_ADDR uses the same value as your
2938 U-Boot configuration in CFG_IMMR.
2941 Configuring the Linux kernel:
2942 -----------------------------
2944 No specific requirements for U-Boot. Make sure you have some root
2945 device (initial ramdisk, NFS) for your target system.
2948 Building a Linux Image:
2949 -----------------------
2951 With U-Boot, "normal" build targets like "zImage" or "bzImage" are
2952 not used. If you use recent kernel source, a new build target
2953 "uImage" will exist which automatically builds an image usable by
2954 U-Boot. Most older kernels also have support for a "pImage" target,
2955 which was introduced for our predecessor project PPCBoot and uses a
2956 100% compatible format.
2965 The "uImage" build target uses a special tool (in 'tools/mkimage') to
2966 encapsulate a compressed Linux kernel image with header information,
2967 CRC32 checksum etc. for use with U-Boot. This is what we are doing:
2969 * build a standard "vmlinux" kernel image (in ELF binary format):
2971 * convert the kernel into a raw binary image:
2973 ${CROSS_COMPILE}-objcopy -O binary \
2974 -R .note -R .comment \
2975 -S vmlinux linux.bin
2977 * compress the binary image:
2981 * package compressed binary image for U-Boot:
2983 mkimage -A ppc -O linux -T kernel -C gzip \
2984 -a 0 -e 0 -n "Linux Kernel Image" \
2985 -d linux.bin.gz uImage
2988 The "mkimage" tool can also be used to create ramdisk images for use
2989 with U-Boot, either separated from the Linux kernel image, or
2990 combined into one file. "mkimage" encapsulates the images with a 64
2991 byte header containing information about target architecture,
2992 operating system, image type, compression method, entry points, time
2993 stamp, CRC32 checksums, etc.
2995 "mkimage" can be called in two ways: to verify existing images and
2996 print the header information, or to build new images.
2998 In the first form (with "-l" option) mkimage lists the information
2999 contained in the header of an existing U-Boot image; this includes
3000 checksum verification:
3002 tools/mkimage -l image
3003 -l ==> list image header information
3005 The second form (with "-d" option) is used to build a U-Boot image
3006 from a "data file" which is used as image payload:
3008 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
3009 -n name -d data_file image
3010 -A ==> set architecture to 'arch'
3011 -O ==> set operating system to 'os'
3012 -T ==> set image type to 'type'
3013 -C ==> set compression type 'comp'
3014 -a ==> set load address to 'addr' (hex)
3015 -e ==> set entry point to 'ep' (hex)
3016 -n ==> set image name to 'name'
3017 -d ==> use image data from 'datafile'
3019 Right now, all Linux kernels for PowerPC systems use the same load
3020 address (0x00000000), but the entry point address depends on the
3023 - 2.2.x kernels have the entry point at 0x0000000C,
3024 - 2.3.x and later kernels have the entry point at 0x00000000.
3026 So a typical call to build a U-Boot image would read:
3028 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
3029 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
3030 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux.gz \
3031 > examples/uImage.TQM850L
3032 Image Name: 2.4.4 kernel for TQM850L
3033 Created: Wed Jul 19 02:34:59 2000
3034 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3035 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
3036 Load Address: 0x00000000
3037 Entry Point: 0x00000000
3039 To verify the contents of the image (or check for corruption):
3041 -> tools/mkimage -l examples/uImage.TQM850L
3042 Image Name: 2.4.4 kernel for TQM850L
3043 Created: Wed Jul 19 02:34:59 2000
3044 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3045 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
3046 Load Address: 0x00000000
3047 Entry Point: 0x00000000
3049 NOTE: for embedded systems where boot time is critical you can trade
3050 speed for memory and install an UNCOMPRESSED image instead: this
3051 needs more space in Flash, but boots much faster since it does not
3052 need to be uncompressed:
3054 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux.gz
3055 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
3056 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
3057 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux \
3058 > examples/uImage.TQM850L-uncompressed
3059 Image Name: 2.4.4 kernel for TQM850L
3060 Created: Wed Jul 19 02:34:59 2000
3061 Image Type: PowerPC Linux Kernel Image (uncompressed)
3062 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
3063 Load Address: 0x00000000
3064 Entry Point: 0x00000000
3067 Similar you can build U-Boot images from a 'ramdisk.image.gz' file
3068 when your kernel is intended to use an initial ramdisk:
3070 -> tools/mkimage -n 'Simple Ramdisk Image' \
3071 > -A ppc -O linux -T ramdisk -C gzip \
3072 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
3073 Image Name: Simple Ramdisk Image
3074 Created: Wed Jan 12 14:01:50 2000
3075 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
3076 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
3077 Load Address: 0x00000000
3078 Entry Point: 0x00000000
3081 Installing a Linux Image:
3082 -------------------------
3084 To downloading a U-Boot image over the serial (console) interface,
3085 you must convert the image to S-Record format:
3087 objcopy -I binary -O srec examples/image examples/image.srec
3089 The 'objcopy' does not understand the information in the U-Boot
3090 image header, so the resulting S-Record file will be relative to
3091 address 0x00000000. To load it to a given address, you need to
3092 specify the target address as 'offset' parameter with the 'loads'
3095 Example: install the image to address 0x40100000 (which on the
3096 TQM8xxL is in the first Flash bank):
3098 => erase 40100000 401FFFFF
3104 ## Ready for S-Record download ...
3105 ~>examples/image.srec
3106 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
3108 15989 15990 15991 15992
3109 [file transfer complete]
3111 ## Start Addr = 0x00000000
3114 You can check the success of the download using the 'iminfo' command;
3115 this includes a checksum verification so you can be sure no data
3116 corruption happened:
3120 ## Checking Image at 40100000 ...
3121 Image Name: 2.2.13 for initrd on TQM850L
3122 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3123 Data Size: 335725 Bytes = 327 kB = 0 MB
3124 Load Address: 00000000
3125 Entry Point: 0000000c
3126 Verifying Checksum ... OK
3132 The "bootm" command is used to boot an application that is stored in
3133 memory (RAM or Flash). In case of a Linux kernel image, the contents
3134 of the "bootargs" environment variable is passed to the kernel as
3135 parameters. You can check and modify this variable using the
3136 "printenv" and "setenv" commands:
3139 => printenv bootargs
3140 bootargs=root=/dev/ram
3142 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
3144 => printenv bootargs
3145 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
3148 ## Booting Linux kernel at 40020000 ...
3149 Image Name: 2.2.13 for NFS on TQM850L
3150 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3151 Data Size: 381681 Bytes = 372 kB = 0 MB
3152 Load Address: 00000000
3153 Entry Point: 0000000c
3154 Verifying Checksum ... OK
3155 Uncompressing Kernel Image ... OK
3156 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
3157 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
3158 time_init: decrementer frequency = 187500000/60
3159 Calibrating delay loop... 49.77 BogoMIPS
3160 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
3163 If you want to boot a Linux kernel with initial ram disk, you pass
3164 the memory addresses of both the kernel and the initrd image (PPBCOOT
3165 format!) to the "bootm" command:
3167 => imi 40100000 40200000
3169 ## Checking Image at 40100000 ...
3170 Image Name: 2.2.13 for initrd on TQM850L
3171 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3172 Data Size: 335725 Bytes = 327 kB = 0 MB
3173 Load Address: 00000000
3174 Entry Point: 0000000c
3175 Verifying Checksum ... OK
3177 ## Checking Image at 40200000 ...
3178 Image Name: Simple Ramdisk Image
3179 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
3180 Data Size: 566530 Bytes = 553 kB = 0 MB
3181 Load Address: 00000000
3182 Entry Point: 00000000
3183 Verifying Checksum ... OK
3185 => bootm 40100000 40200000
3186 ## Booting Linux kernel 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
3193 Uncompressing Kernel Image ... OK
3194 ## Loading RAMDisk Image at 40200000 ...
3195 Image Name: Simple Ramdisk Image
3196 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
3197 Data Size: 566530 Bytes = 553 kB = 0 MB
3198 Load Address: 00000000
3199 Entry Point: 00000000
3200 Verifying Checksum ... OK
3201 Loading Ramdisk ... OK
3202 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
3203 Boot arguments: root=/dev/ram
3204 time_init: decrementer frequency = 187500000/60
3205 Calibrating delay loop... 49.77 BogoMIPS
3207 RAMDISK: Compressed image found at block 0
3208 VFS: Mounted root (ext2 filesystem).
3212 Boot Linux and pass a flat device tree:
3215 First, U-Boot must be compiled with the appropriate defines. See the section
3216 titled "Linux Kernel Interface" above for a more in depth explanation. The
3217 following is an example of how to start a kernel and pass an updated
3223 oft=oftrees/mpc8540ads.dtb
3224 => tftp $oftaddr $oft
3225 Speed: 1000, full duplex
3227 TFTP from server 192.168.1.1; our IP address is 192.168.1.101
3228 Filename 'oftrees/mpc8540ads.dtb'.
3229 Load address: 0x300000
3232 Bytes transferred = 4106 (100a hex)
3233 => tftp $loadaddr $bootfile
3234 Speed: 1000, full duplex
3236 TFTP from server 192.168.1.1; our IP address is 192.168.1.2
3238 Load address: 0x200000
3239 Loading:############
3241 Bytes transferred = 1029407 (fb51f hex)
3246 => bootm $loadaddr - $oftaddr
3247 ## Booting image at 00200000 ...
3248 Image Name: Linux-2.6.17-dirty
3249 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3250 Data Size: 1029343 Bytes = 1005.2 kB
3251 Load Address: 00000000
3252 Entry Point: 00000000
3253 Verifying Checksum ... OK
3254 Uncompressing Kernel Image ... OK
3255 Booting using flat device tree at 0x300000
3256 Using MPC85xx ADS machine description
3257 Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb
3261 More About U-Boot Image Types:
3262 ------------------------------
3264 U-Boot supports the following image types:
3266 "Standalone Programs" are directly runnable in the environment
3267 provided by U-Boot; it is expected that (if they behave
3268 well) you can continue to work in U-Boot after return from
3269 the Standalone Program.
3270 "OS Kernel Images" are usually images of some Embedded OS which
3271 will take over control completely. Usually these programs
3272 will install their own set of exception handlers, device
3273 drivers, set up the MMU, etc. - this means, that you cannot
3274 expect to re-enter U-Boot except by resetting the CPU.
3275 "RAMDisk Images" are more or less just data blocks, and their
3276 parameters (address, size) are passed to an OS kernel that is
3278 "Multi-File Images" contain several images, typically an OS
3279 (Linux) kernel image and one or more data images like
3280 RAMDisks. This construct is useful for instance when you want
3281 to boot over the network using BOOTP etc., where the boot
3282 server provides just a single image file, but you want to get
3283 for instance an OS kernel and a RAMDisk image.
3285 "Multi-File Images" start with a list of image sizes, each
3286 image size (in bytes) specified by an "uint32_t" in network
3287 byte order. This list is terminated by an "(uint32_t)0".
3288 Immediately after the terminating 0 follow the images, one by
3289 one, all aligned on "uint32_t" boundaries (size rounded up to
3290 a multiple of 4 bytes).
3292 "Firmware Images" are binary images containing firmware (like
3293 U-Boot or FPGA images) which usually will be programmed to
3296 "Script files" are command sequences that will be executed by
3297 U-Boot's command interpreter; this feature is especially
3298 useful when you configure U-Boot to use a real shell (hush)
3299 as command interpreter.
3305 One of the features of U-Boot is that you can dynamically load and
3306 run "standalone" applications, which can use some resources of
3307 U-Boot like console I/O functions or interrupt services.
3309 Two simple examples are included with the sources:
3314 'examples/hello_world.c' contains a small "Hello World" Demo
3315 application; it is automatically compiled when you build U-Boot.
3316 It's configured to run at address 0x00040004, so you can play with it
3320 ## Ready for S-Record download ...
3321 ~>examples/hello_world.srec
3322 1 2 3 4 5 6 7 8 9 10 11 ...
3323 [file transfer complete]
3325 ## Start Addr = 0x00040004
3327 => go 40004 Hello World! This is a test.
3328 ## Starting application at 0x00040004 ...
3339 Hit any key to exit ...
3341 ## Application terminated, rc = 0x0
3343 Another example, which demonstrates how to register a CPM interrupt
3344 handler with the U-Boot code, can be found in 'examples/timer.c'.
3345 Here, a CPM timer is set up to generate an interrupt every second.
3346 The interrupt service routine is trivial, just printing a '.'
3347 character, but this is just a demo program. The application can be
3348 controlled by the following keys:
3350 ? - print current values og the CPM Timer registers
3351 b - enable interrupts and start timer
3352 e - stop timer and disable interrupts
3353 q - quit application
3356 ## Ready for S-Record download ...
3357 ~>examples/timer.srec
3358 1 2 3 4 5 6 7 8 9 10 11 ...
3359 [file transfer complete]
3361 ## Start Addr = 0x00040004
3364 ## Starting application at 0x00040004 ...
3367 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
3370 [q, b, e, ?] Set interval 1000000 us
3373 [q, b, e, ?] ........
3374 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
3377 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
3380 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
3383 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
3385 [q, b, e, ?] ...Stopping timer
3387 [q, b, e, ?] ## Application terminated, rc = 0x0
3393 Over time, many people have reported problems when trying to use the
3394 "minicom" terminal emulation program for serial download. I (wd)
3395 consider minicom to be broken, and recommend not to use it. Under
3396 Unix, I recommend to use C-Kermit for general purpose use (and
3397 especially for kermit binary protocol download ("loadb" command), and
3398 use "cu" for S-Record download ("loads" command).
3400 Nevertheless, if you absolutely want to use it try adding this
3401 configuration to your "File transfer protocols" section:
3403 Name Program Name U/D FullScr IO-Red. Multi
3404 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
3405 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
3411 Starting at version 0.9.2, U-Boot supports NetBSD both as host
3412 (build U-Boot) and target system (boots NetBSD/mpc8xx).
3414 Building requires a cross environment; it is known to work on
3415 NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
3416 need gmake since the Makefiles are not compatible with BSD make).
3417 Note that the cross-powerpc package does not install include files;
3418 attempting to build U-Boot will fail because <machine/ansi.h> is
3419 missing. This file has to be installed and patched manually:
3421 # cd /usr/pkg/cross/powerpc-netbsd/include
3423 # ln -s powerpc machine
3424 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
3425 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
3427 Native builds *don't* work due to incompatibilities between native
3428 and U-Boot include files.
3430 Booting assumes that (the first part of) the image booted is a
3431 stage-2 loader which in turn loads and then invokes the kernel
3432 proper. Loader sources will eventually appear in the NetBSD source
3433 tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
3434 meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz
3437 Implementation Internals:
3438 =========================
3440 The following is not intended to be a complete description of every
3441 implementation detail. However, it should help to understand the
3442 inner workings of U-Boot and make it easier to port it to custom
3446 Initial Stack, Global Data:
3447 ---------------------------
3449 The implementation of U-Boot is complicated by the fact that U-Boot
3450 starts running out of ROM (flash memory), usually without access to
3451 system RAM (because the memory controller is not initialized yet).
3452 This means that we don't have writable Data or BSS segments, and BSS
3453 is not initialized as zero. To be able to get a C environment working
3454 at all, we have to allocate at least a minimal stack. Implementation
3455 options for this are defined and restricted by the CPU used: Some CPU
3456 models provide on-chip memory (like the IMMR area on MPC8xx and
3457 MPC826x processors), on others (parts of) the data cache can be
3458 locked as (mis-) used as memory, etc.
3460 Chris Hallinan posted a good summary of these issues to the
3461 u-boot-users mailing list:
3463 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
3464 From: "Chris Hallinan" <clh@net1plus.com>
3465 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
3468 Correct me if I'm wrong, folks, but the way I understand it
3469 is this: Using DCACHE as initial RAM for Stack, etc, does not
3470 require any physical RAM backing up the cache. The cleverness
3471 is that the cache is being used as a temporary supply of
3472 necessary storage before the SDRAM controller is setup. It's
3473 beyond the scope of this list to expain the details, but you
3474 can see how this works by studying the cache architecture and
3475 operation in the architecture and processor-specific manuals.
3477 OCM is On Chip Memory, which I believe the 405GP has 4K. It
3478 is another option for the system designer to use as an
3479 initial stack/ram area prior to SDRAM being available. Either
3480 option should work for you. Using CS 4 should be fine if your
3481 board designers haven't used it for something that would
3482 cause you grief during the initial boot! It is frequently not
3485 CFG_INIT_RAM_ADDR should be somewhere that won't interfere
3486 with your processor/board/system design. The default value
3487 you will find in any recent u-boot distribution in
3488 walnut.h should work for you. I'd set it to a value larger
3489 than your SDRAM module. If you have a 64MB SDRAM module, set
3490 it above 400_0000. Just make sure your board has no resources
3491 that are supposed to respond to that address! That code in
3492 start.S has been around a while and should work as is when
3493 you get the config right.
3498 It is essential to remember this, since it has some impact on the C
3499 code for the initialization procedures:
3501 * Initialized global data (data segment) is read-only. Do not attempt
3504 * Do not use any unitialized global data (or implicitely initialized
3505 as zero data - BSS segment) at all - this is undefined, initiali-
3506 zation is performed later (when relocating to RAM).
3508 * Stack space is very limited. Avoid big data buffers or things like
3511 Having only the stack as writable memory limits means we cannot use
3512 normal global data to share information beween the code. But it
3513 turned out that the implementation of U-Boot can be greatly
3514 simplified by making a global data structure (gd_t) available to all
3515 functions. We could pass a pointer to this data as argument to _all_
3516 functions, but this would bloat the code. Instead we use a feature of
3517 the GCC compiler (Global Register Variables) to share the data: we
3518 place a pointer (gd) to the global data into a register which we
3519 reserve for this purpose.
3521 When choosing a register for such a purpose we are restricted by the
3522 relevant (E)ABI specifications for the current architecture, and by
3523 GCC's implementation.
3525 For PowerPC, the following registers have specific use:
3528 R3-R4: parameter passing and return values
3529 R5-R10: parameter passing
3530 R13: small data area pointer
3534 (U-Boot also uses R14 as internal GOT pointer.)
3536 ==> U-Boot will use R29 to hold a pointer to the global data
3538 Note: on PPC, we could use a static initializer (since the
3539 address of the global data structure is known at compile time),
3540 but it turned out that reserving a register results in somewhat
3541 smaller code - although the code savings are not that big (on
3542 average for all boards 752 bytes for the whole U-Boot image,
3543 624 text + 127 data).
3545 On ARM, the following registers are used:
3547 R0: function argument word/integer result
3548 R1-R3: function argument word
3550 R10: stack limit (used only if stack checking if enabled)
3551 R11: argument (frame) pointer
3552 R12: temporary workspace
3555 R15: program counter
3557 ==> U-Boot will use R8 to hold a pointer to the global data
3559 NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope,
3560 or current versions of GCC may "optimize" the code too much.
3565 U-Boot runs in system state and uses physical addresses, i.e. the
3566 MMU is not used either for address mapping nor for memory protection.
3568 The available memory is mapped to fixed addresses using the memory
3569 controller. In this process, a contiguous block is formed for each
3570 memory type (Flash, SDRAM, SRAM), even when it consists of several
3571 physical memory banks.
3573 U-Boot is installed in the first 128 kB of the first Flash bank (on
3574 TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
3575 booting and sizing and initializing DRAM, the code relocates itself
3576 to the upper end of DRAM. Immediately below the U-Boot code some
3577 memory is reserved for use by malloc() [see CFG_MALLOC_LEN
3578 configuration setting]. Below that, a structure with global Board
3579 Info data is placed, followed by the stack (growing downward).
3581 Additionally, some exception handler code is copied to the low 8 kB
3582 of DRAM (0x00000000 ... 0x00001FFF).
3584 So a typical memory configuration with 16 MB of DRAM could look like
3587 0x0000 0000 Exception Vector code
3590 0x0000 2000 Free for Application Use
3596 0x00FB FF20 Monitor Stack (Growing downward)
3597 0x00FB FFAC Board Info Data and permanent copy of global data
3598 0x00FC 0000 Malloc Arena
3601 0x00FE 0000 RAM Copy of Monitor Code
3602 ... eventually: LCD or video framebuffer
3603 ... eventually: pRAM (Protected RAM - unchanged by reset)
3604 0x00FF FFFF [End of RAM]
3607 System Initialization:
3608 ----------------------
3610 In the reset configuration, U-Boot starts at the reset entry point
3611 (on most PowerPC systens at address 0x00000100). Because of the reset
3612 configuration for CS0# this is a mirror of the onboard Flash memory.
3613 To be able to re-map memory U-Boot then jumps to its link address.
3614 To be able to implement the initialization code in C, a (small!)
3615 initial stack is set up in the internal Dual Ported RAM (in case CPUs
3616 which provide such a feature like MPC8xx or MPC8260), or in a locked
3617 part of the data cache. After that, U-Boot initializes the CPU core,
3618 the caches and the SIU.
3620 Next, all (potentially) available memory banks are mapped using a
3621 preliminary mapping. For example, we put them on 512 MB boundaries
3622 (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
3623 on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
3624 programmed for SDRAM access. Using the temporary configuration, a
3625 simple memory test is run that determines the size of the SDRAM
3628 When there is more than one SDRAM bank, and the banks are of
3629 different size, the largest is mapped first. For equal size, the first
3630 bank (CS2#) is mapped first. The first mapping is always for address
3631 0x00000000, with any additional banks following immediately to create
3632 contiguous memory starting from 0.
3634 Then, the monitor installs itself at the upper end of the SDRAM area
3635 and allocates memory for use by malloc() and for the global Board
3636 Info data; also, the exception vector code is copied to the low RAM
3637 pages, and the final stack is set up.
3639 Only after this relocation will you have a "normal" C environment;
3640 until that you are restricted in several ways, mostly because you are
3641 running from ROM, and because the code will have to be relocated to a
3645 U-Boot Porting Guide:
3646 ----------------------
3648 [Based on messages by Jerry Van Baren in the U-Boot-Users mailing
3652 int main (int argc, char *argv[])
3654 sighandler_t no_more_time;
3656 signal (SIGALRM, no_more_time);
3657 alarm (PROJECT_DEADLINE - toSec (3 * WEEK));
3659 if (available_money > available_manpower) {
3660 pay consultant to port U-Boot;
3664 Download latest U-Boot source;
3666 Subscribe to u-boot-users mailing list;
3669 email ("Hi, I am new to U-Boot, how do I get started?");
3673 Read the README file in the top level directory;
3674 Read http://www.denx.de/twiki/bin/view/DULG/Manual ;
3675 Read the source, Luke;
3678 if (available_money > toLocalCurrency ($2500)) {
3681 Add a lot of aggravation and time;
3684 Create your own board support subdirectory;
3686 Create your own board config file;
3690 Add / modify source code;
3694 email ("Hi, I am having problems...");
3696 Send patch file to Wolfgang;
3701 void no_more_time (int sig)
3710 All contributions to U-Boot should conform to the Linux kernel
3711 coding style; see the file "Documentation/CodingStyle" and the script
3712 "scripts/Lindent" in your Linux kernel source directory. In sources
3713 originating from U-Boot a style corresponding to "Lindent -pcs" (adding
3714 spaces before parameters to function calls) is actually used.
3716 Source files originating from a different project (for example the
3717 MTD subsystem) are generally exempt from these guidelines and are not
3718 reformated to ease subsequent migration to newer versions of those
3721 Please note that U-Boot is implemented in C (and to some small parts in
3722 Assembler); no C++ is used, so please do not use C++ style comments (//)
3725 Please also stick to the following formatting rules:
3726 - remove any trailing white space
3727 - use TAB characters for indentation, not spaces
3728 - make sure NOT to use DOS '\r\n' line feeds
3729 - do not add more than 2 empty lines to source files
3730 - do not add trailing empty lines to source files
3732 Submissions which do not conform to the standards may be returned
3733 with a request to reformat the changes.
3739 Since the number of patches for U-Boot is growing, we need to
3740 establish some rules. Submissions which do not conform to these rules
3741 may be rejected, even when they contain important and valuable stuff.
3743 Patches shall be sent to the u-boot-users mailing list.
3745 When you send a patch, please include the following information with
3748 * For bug fixes: a description of the bug and how your patch fixes
3749 this bug. Please try to include a way of demonstrating that the
3750 patch actually fixes something.
3752 * For new features: a description of the feature and your
3755 * A CHANGELOG entry as plaintext (separate from the patch)
3757 * For major contributions, your entry to the CREDITS file
3759 * When you add support for a new board, don't forget to add this
3760 board to the MAKEALL script, too.
3762 * If your patch adds new configuration options, don't forget to
3763 document these in the README file.
3765 * The patch itself. If you are accessing the CVS repository use "cvs
3766 update; cvs diff -puRN"; else, use "diff -purN OLD NEW". If your
3767 version of diff does not support these options, then get the latest
3768 version of GNU diff.
3770 The current directory when running this command shall be the top
3771 level directory of the U-Boot source tree, or it's parent directory
3772 (i. e. please make sure that your patch includes sufficient
3773 directory information for the affected files).
3775 We accept patches as plain text, MIME attachments or as uuencoded
3778 * If one logical set of modifications affects or creates several
3779 files, all these changes shall be submitted in a SINGLE patch file.
3781 * Changesets that contain different, unrelated modifications shall be
3782 submitted as SEPARATE patches, one patch per changeset.
3787 * Before sending the patch, run the MAKEALL script on your patched
3788 source tree and make sure that no errors or warnings are reported
3789 for any of the boards.
3791 * Keep your modifications to the necessary minimum: A patch
3792 containing several unrelated changes or arbitrary reformats will be
3793 returned with a request to re-formatting / split it.
3795 * If you modify existing code, make sure that your new code does not
3796 add to the memory footprint of the code ;-) Small is beautiful!
3797 When adding new features, these should compile conditionally only
3798 (using #ifdef), and the resulting code with the new feature
3799 disabled must not need more memory than the old code without your
3802 * Remember that there is a size limit of 40 kB per message on the
3803 u-boot-users mailing list. Compression may help.
projects / platform / kernel / u-boot.git / blob