2 # (C) Copyright 2000 - 2008
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. The MAINTAINERS file lists board
61 In case you have questions about, problems with or contributions for
62 U-Boot you should send a message to the U-Boot mailing list at
63 <u-boot-users@lists.sourceforge.net>. There is also an archive of
64 previous traffic on the mailing list - please search the archive
65 before asking FAQ's. Please see
66 http://lists.sourceforge.net/lists/listinfo/u-boot-users/
69 Where to get source code:
70 =========================
72 The U-Boot source code is maintained in the git repository at
73 git://www.denx.de/git/u-boot.git ; you can browse it online at
74 http://www.denx.de/cgi-bin/gitweb.cgi?p=u-boot.git;a=summary
76 The "snapshot" links on this page allow you to download tarballs of
77 any version you might be interested in. Ofifcial releases are also
78 available for FTP download from the ftp://ftp.denx.de/pub/u-boot/
81 Pre-built (and tested) images are available from
82 ftp://ftp.denx.de/pub/u-boot/images/
88 - start from 8xxrom sources
89 - create PPCBoot project (http://sourceforge.net/projects/ppcboot)
91 - make it easier to add custom boards
92 - make it possible to add other [PowerPC] CPUs
93 - extend functions, especially:
94 * Provide extended interface to Linux boot loader
97 * PCMCIA / CompactFLash / ATA disk / SCSI ... boot
98 - create ARMBoot project (http://sourceforge.net/projects/armboot)
99 - add other CPU families (starting with ARM)
100 - create U-Boot project (http://sourceforge.net/projects/u-boot)
101 - current project page: see http://www.denx.de/wiki/UBoot
107 The "official" name of this project is "Das U-Boot". The spelling
108 "U-Boot" shall be used in all written text (documentation, comments
109 in source files etc.). Example:
111 This is the README file for the U-Boot project.
113 File names etc. shall be based on the string "u-boot". Examples:
115 include/asm-ppc/u-boot.h
117 #include <asm/u-boot.h>
119 Variable names, preprocessor constants etc. shall be either based on
120 the string "u_boot" or on "U_BOOT". Example:
122 U_BOOT_VERSION u_boot_logo
123 IH_OS_U_BOOT u_boot_hush_start
129 U-Boot uses a 3 level version number containing a version, a
130 sub-version, and a patchlevel: "U-Boot-2.34.5" means version "2",
131 sub-version "34", and patchlevel "4".
133 The patchlevel is used to indicate certain stages of development
134 between released versions, i. e. officially released versions of
135 U-Boot will always have a patchlevel of "0".
141 - board Board dependent files
142 - common Misc architecture independent functions
143 - cpu CPU specific files
144 - 74xx_7xx Files specific to Freescale MPC74xx and 7xx CPUs
145 - arm720t Files specific to ARM 720 CPUs
146 - arm920t Files specific to ARM 920 CPUs
147 - at91rm9200 Files specific to Atmel AT91RM9200 CPU
148 - imx Files specific to Freescale MC9328 i.MX CPUs
149 - s3c24x0 Files specific to Samsung S3C24X0 CPUs
150 - arm925t Files specific to ARM 925 CPUs
151 - arm926ejs Files specific to ARM 926 CPUs
152 - arm1136 Files specific to ARM 1136 CPUs
153 - at32ap Files specific to Atmel AVR32 AP CPUs
154 - i386 Files specific to i386 CPUs
155 - ixp Files specific to Intel XScale IXP CPUs
156 - leon2 Files specific to Gaisler LEON2 SPARC CPU
157 - leon3 Files specific to Gaisler LEON3 SPARC CPU
158 - mcf52x2 Files specific to Freescale ColdFire MCF52x2 CPUs
159 - mcf5227x Files specific to Freescale ColdFire MCF5227x CPUs
160 - mcf532x Files specific to Freescale ColdFire MCF5329 CPUs
161 - mcf5445x Files specific to Freescale ColdFire MCF5445x CPUs
162 - mcf547x_8x Files specific to Freescale ColdFire MCF547x_8x CPUs
163 - mips Files specific to MIPS CPUs
164 - mpc5xx Files specific to Freescale MPC5xx CPUs
165 - mpc5xxx Files specific to Freescale MPC5xxx CPUs
166 - mpc8xx Files specific to Freescale MPC8xx CPUs
167 - mpc8220 Files specific to Freescale MPC8220 CPUs
168 - mpc824x Files specific to Freescale MPC824x CPUs
169 - mpc8260 Files specific to Freescale MPC8260 CPUs
170 - mpc85xx Files specific to Freescale MPC85xx CPUs
171 - nios Files specific to Altera NIOS CPUs
172 - nios2 Files specific to Altera Nios-II CPUs
173 - ppc4xx Files specific to AMCC PowerPC 4xx CPUs
174 - pxa Files specific to Intel XScale PXA CPUs
175 - s3c44b0 Files specific to Samsung S3C44B0 CPUs
176 - sa1100 Files specific to Intel StrongARM SA1100 CPUs
177 - disk Code for disk drive partition handling
178 - doc Documentation (don't expect too much)
179 - drivers Commonly used device drivers
180 - dtt Digital Thermometer and Thermostat drivers
181 - examples Example code for standalone applications, etc.
182 - include Header Files
183 - lib_arm Files generic to ARM architecture
184 - lib_avr32 Files generic to AVR32 architecture
185 - lib_generic Files generic to all architectures
186 - lib_i386 Files generic to i386 architecture
187 - lib_m68k Files generic to m68k architecture
188 - lib_mips Files generic to MIPS architecture
189 - lib_nios Files generic to NIOS architecture
190 - lib_ppc Files generic to PowerPC architecture
191 - lib_sparc Files generic to SPARC architecture
192 - libfdt Library files to support flattened device trees
193 - net Networking code
194 - post Power On Self Test
195 - rtc Real Time Clock drivers
196 - tools Tools to build S-Record or U-Boot images, etc.
198 Software Configuration:
199 =======================
201 Configuration is usually done using C preprocessor defines; the
202 rationale behind that is to avoid dead code whenever possible.
204 There are two classes of configuration variables:
206 * Configuration _OPTIONS_:
207 These are selectable by the user and have names beginning with
210 * Configuration _SETTINGS_:
211 These depend on the hardware etc. and should not be meddled with if
212 you don't know what you're doing; they have names beginning with
215 Later we will add a configuration tool - probably similar to or even
216 identical to what's used for the Linux kernel. Right now, we have to
217 do the configuration by hand, which means creating some symbolic
218 links and editing some configuration files. We use the TQM8xxL boards
222 Selection of Processor Architecture and Board Type:
223 ---------------------------------------------------
225 For all supported boards there are ready-to-use default
226 configurations available; just type "make <board_name>_config".
228 Example: For a TQM823L module type:
233 For the Cogent platform, you need to specify the cpu type as well;
234 e.g. "make cogent_mpc8xx_config". And also configure the cogent
235 directory according to the instructions in cogent/README.
238 Configuration Options:
239 ----------------------
241 Configuration depends on the combination of board and CPU type; all
242 such information is kept in a configuration file
243 "include/configs/<board_name>.h".
245 Example: For a TQM823L module, all configuration settings are in
246 "include/configs/TQM823L.h".
249 Many of the options are named exactly as the corresponding Linux
250 kernel configuration options. The intention is to make it easier to
251 build a config tool - later.
254 The following options need to be configured:
256 - CPU Type: Define exactly one, e.g. CONFIG_MPC85XX.
258 - Board Type: Define exactly one, e.g. CONFIG_MPC8540ADS.
260 - CPU Daughterboard Type: (if CONFIG_ATSTK1000 is defined)
261 Define exactly one, e.g. CONFIG_ATSTK1002
263 - CPU Module Type: (if CONFIG_COGENT is defined)
264 Define exactly one of
266 --- FIXME --- not tested yet:
267 CONFIG_CMA286_60, CONFIG_CMA286_21, CONFIG_CMA286_60P,
268 CONFIG_CMA287_23, CONFIG_CMA287_50
270 - Motherboard Type: (if CONFIG_COGENT is defined)
271 Define exactly one of
272 CONFIG_CMA101, CONFIG_CMA102
274 - Motherboard I/O Modules: (if CONFIG_COGENT is defined)
275 Define one or more of
278 - Motherboard Options: (if CONFIG_CMA101 or CONFIG_CMA102 are defined)
279 Define one or more of
280 CONFIG_LCD_HEARTBEAT - update a character position on
281 the lcd display every second with
284 - Board flavour: (if CONFIG_MPC8260ADS is defined)
287 CFG_8260ADS - original MPC8260ADS
288 CFG_8266ADS - MPC8266ADS
289 CFG_PQ2FADS - PQ2FADS-ZU or PQ2FADS-VR
290 CFG_8272ADS - MPC8272ADS
292 - MPC824X Family Member (if CONFIG_MPC824X is defined)
293 Define exactly one of
294 CONFIG_MPC8240, CONFIG_MPC8245
296 - 8xx CPU Options: (if using an MPC8xx cpu)
297 CONFIG_8xx_GCLK_FREQ - deprecated: CPU clock if
298 get_gclk_freq() cannot work
299 e.g. if there is no 32KHz
300 reference PIT/RTC clock
301 CONFIG_8xx_OSCLK - PLL input clock (either EXTCLK
304 - 859/866/885 CPU options: (if using a MPC859 or MPC866 or MPC885 CPU):
307 CONFIG_8xx_CPUCLK_DEFAULT
308 See doc/README.MPC866
312 Define this to measure the actual CPU clock instead
313 of relying on the correctness of the configured
314 values. Mostly useful for board bringup to make sure
315 the PLL is locked at the intended frequency. Note
316 that this requires a (stable) reference clock (32 kHz
317 RTC clock or CFG_8XX_XIN)
319 - Intel Monahans options:
320 CFG_MONAHANS_RUN_MODE_OSC_RATIO
322 Defines the Monahans run mode to oscillator
323 ratio. Valid values are 8, 16, 24, 31. The core
324 frequency is this value multiplied by 13 MHz.
326 CFG_MONAHANS_TURBO_RUN_MODE_RATIO
328 Defines the Monahans turbo mode to oscillator
329 ratio. Valid values are 1 (default if undefined) and
330 2. The core frequency as calculated above is multiplied
333 - Linux Kernel Interface:
336 U-Boot stores all clock information in Hz
337 internally. For binary compatibility with older Linux
338 kernels (which expect the clocks passed in the
339 bd_info data to be in MHz) the environment variable
340 "clocks_in_mhz" can be defined so that U-Boot
341 converts clock data to MHZ before passing it to the
343 When CONFIG_CLOCKS_IN_MHZ is defined, a definition of
344 "clocks_in_mhz=1" is automatically included in the
347 CONFIG_MEMSIZE_IN_BYTES [relevant for MIPS only]
349 When transfering memsize parameter to linux, some versions
350 expect it to be in bytes, others in MB.
351 Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes.
353 CONFIG_OF_LIBFDT / CONFIG_OF_FLAT_TREE
355 New kernel versions are expecting firmware settings to be
356 passed using flattened device trees (based on open firmware
360 * New libfdt-based support
361 * Adds the "fdt" command
362 * The bootm command automatically updates the fdt
365 * Deprecated, see CONFIG_OF_LIBFDT
366 * Original ft_build.c-based support
367 * Automatically modifies the dft as part of the bootm command
368 * The environment variable "disable_of", when set,
369 disables this functionality.
371 OF_CPU - The proper name of the cpus node.
372 OF_SOC - The proper name of the soc node.
373 OF_TBCLK - The timebase frequency.
374 OF_STDOUT_PATH - The path to the console device
376 boards with QUICC Engines require OF_QE to set UCC mac addresses
378 CONFIG_OF_BOARD_SETUP
380 Board code has addition modification that it wants to make
381 to the flat device tree before handing it off to the kernel
385 This define fills in the correct boot cpu in the boot
386 param header, the default value is zero if undefined.
391 Define this if you want support for Amba PrimeCell PL010 UARTs.
395 Define this if you want support for Amba PrimeCell PL011 UARTs.
399 If you have Amba PrimeCell PL011 UARTs, set this variable to
400 the clock speed of the UARTs.
404 If you have Amba PrimeCell PL010 or PL011 UARTs on your board,
405 define this to a list of base addresses for each (supported)
406 port. See e.g. include/configs/versatile.h
410 Depending on board, define exactly one serial port
411 (like CONFIG_8xx_CONS_SMC1, CONFIG_8xx_CONS_SMC2,
412 CONFIG_8xx_CONS_SCC1, ...), or switch off the serial
413 console by defining CONFIG_8xx_CONS_NONE
415 Note: if CONFIG_8xx_CONS_NONE is defined, the serial
416 port routines must be defined elsewhere
417 (i.e. serial_init(), serial_getc(), ...)
420 Enables console device for a color framebuffer. Needs following
421 defines (cf. smiLynxEM, i8042, board/eltec/bab7xx)
422 VIDEO_FB_LITTLE_ENDIAN graphic memory organisation
424 VIDEO_HW_RECTFILL graphic chip supports
427 VIDEO_HW_BITBLT graphic chip supports
428 bit-blit (cf. smiLynxEM)
429 VIDEO_VISIBLE_COLS visible pixel columns
431 VIDEO_VISIBLE_ROWS visible pixel rows
432 VIDEO_PIXEL_SIZE bytes per pixel
433 VIDEO_DATA_FORMAT graphic data format
434 (0-5, cf. cfb_console.c)
435 VIDEO_FB_ADRS framebuffer address
436 VIDEO_KBD_INIT_FCT keyboard int fct
437 (i.e. i8042_kbd_init())
438 VIDEO_TSTC_FCT test char fct
440 VIDEO_GETC_FCT get char fct
442 CONFIG_CONSOLE_CURSOR cursor drawing on/off
443 (requires blink timer
445 CFG_CONSOLE_BLINK_COUNT blink interval (cf. i8042.c)
446 CONFIG_CONSOLE_TIME display time/date info in
448 (requires CONFIG_CMD_DATE)
449 CONFIG_VIDEO_LOGO display Linux logo in
451 CONFIG_VIDEO_BMP_LOGO use bmp_logo.h instead of
452 linux_logo.h for logo.
453 Requires CONFIG_VIDEO_LOGO
454 CONFIG_CONSOLE_EXTRA_INFO
455 addional board info beside
458 When CONFIG_CFB_CONSOLE is defined, video console is
459 default i/o. Serial console can be forced with
460 environment 'console=serial'.
462 When CONFIG_SILENT_CONSOLE is defined, all console
463 messages (by U-Boot and Linux!) can be silenced with
464 the "silent" environment variable. See
465 doc/README.silent for more information.
468 CONFIG_BAUDRATE - in bps
469 Select one of the baudrates listed in
470 CFG_BAUDRATE_TABLE, see below.
471 CFG_BRGCLK_PRESCALE, baudrate prescale
473 - Interrupt driven serial port input:
474 CONFIG_SERIAL_SOFTWARE_FIFO
477 Use an interrupt handler for receiving data on the
478 serial port. It also enables using hardware handshake
479 (RTS/CTS) and UART's built-in FIFO. Set the number of
480 bytes the interrupt driven input buffer should have.
482 Leave undefined to disable this feature, including
483 disable the buffer and hardware handshake.
485 - Console UART Number:
489 If defined internal UART1 (and not UART0) is used
490 as default U-Boot console.
492 - Boot Delay: CONFIG_BOOTDELAY - in seconds
493 Delay before automatically booting the default image;
494 set to -1 to disable autoboot.
496 See doc/README.autoboot for these options that
497 work with CONFIG_BOOTDELAY. None are required.
498 CONFIG_BOOT_RETRY_TIME
499 CONFIG_BOOT_RETRY_MIN
500 CONFIG_AUTOBOOT_KEYED
501 CONFIG_AUTOBOOT_PROMPT
502 CONFIG_AUTOBOOT_DELAY_STR
503 CONFIG_AUTOBOOT_STOP_STR
504 CONFIG_AUTOBOOT_DELAY_STR2
505 CONFIG_AUTOBOOT_STOP_STR2
506 CONFIG_ZERO_BOOTDELAY_CHECK
507 CONFIG_RESET_TO_RETRY
511 Only needed when CONFIG_BOOTDELAY is enabled;
512 define a command string that is automatically executed
513 when no character is read on the console interface
514 within "Boot Delay" after reset.
517 This can be used to pass arguments to the bootm
518 command. The value of CONFIG_BOOTARGS goes into the
519 environment value "bootargs".
521 CONFIG_RAMBOOT and CONFIG_NFSBOOT
522 The value of these goes into the environment as
523 "ramboot" and "nfsboot" respectively, and can be used
524 as a convenience, when switching between booting from
530 When this option is #defined, the existence of the
531 environment variable "preboot" will be checked
532 immediately before starting the CONFIG_BOOTDELAY
533 countdown and/or running the auto-boot command resp.
534 entering interactive mode.
536 This feature is especially useful when "preboot" is
537 automatically generated or modified. For an example
538 see the LWMON board specific code: here "preboot" is
539 modified when the user holds down a certain
540 combination of keys on the (special) keyboard when
543 - Serial Download Echo Mode:
545 If defined to 1, all characters received during a
546 serial download (using the "loads" command) are
547 echoed back. This might be needed by some terminal
548 emulations (like "cu"), but may as well just take
549 time on others. This setting #define's the initial
550 value of the "loads_echo" environment variable.
552 - Kgdb Serial Baudrate: (if CONFIG_CMD_KGDB is defined)
554 Select one of the baudrates listed in
555 CFG_BAUDRATE_TABLE, see below.
558 Monitor commands can be included or excluded
559 from the build by using the #include files
560 "config_cmd_all.h" and #undef'ing unwanted
561 commands, or using "config_cmd_default.h"
562 and augmenting with additional #define's
565 The default command configuration includes all commands
566 except those marked below with a "*".
568 CONFIG_CMD_ASKENV * ask for env variable
569 CONFIG_CMD_AUTOSCRIPT Autoscript Support
570 CONFIG_CMD_BDI bdinfo
571 CONFIG_CMD_BEDBUG * Include BedBug Debugger
572 CONFIG_CMD_BMP * BMP support
573 CONFIG_CMD_BSP * Board specific commands
574 CONFIG_CMD_BOOTD bootd
575 CONFIG_CMD_CACHE * icache, dcache
576 CONFIG_CMD_CONSOLE coninfo
577 CONFIG_CMD_DATE * support for RTC, date/time...
578 CONFIG_CMD_DHCP * DHCP support
579 CONFIG_CMD_DIAG * Diagnostics
580 CONFIG_CMD_DOC * Disk-On-Chip Support
581 CONFIG_CMD_DTT * Digital Therm and Thermostat
582 CONFIG_CMD_ECHO echo arguments
583 CONFIG_CMD_EEPROM * EEPROM read/write support
584 CONFIG_CMD_ELF * bootelf, bootvx
585 CONFIG_CMD_ENV saveenv
586 CONFIG_CMD_FDC * Floppy Disk Support
587 CONFIG_CMD_FAT * FAT partition support
588 CONFIG_CMD_FDOS * Dos diskette Support
589 CONFIG_CMD_FLASH flinfo, erase, protect
590 CONFIG_CMD_FPGA FPGA device initialization support
591 CONFIG_CMD_HWFLOW * RTS/CTS hw flow control
592 CONFIG_CMD_I2C * I2C serial bus support
593 CONFIG_CMD_IDE * IDE harddisk support
594 CONFIG_CMD_IMI iminfo
595 CONFIG_CMD_IMLS List all found images
596 CONFIG_CMD_IMMAP * IMMR dump support
597 CONFIG_CMD_IRQ * irqinfo
598 CONFIG_CMD_ITEST Integer/string test of 2 values
599 CONFIG_CMD_JFFS2 * JFFS2 Support
600 CONFIG_CMD_KGDB * kgdb
601 CONFIG_CMD_LOADB loadb
602 CONFIG_CMD_LOADS loads
603 CONFIG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base,
605 CONFIG_CMD_MISC Misc functions like sleep etc
606 CONFIG_CMD_MMC * MMC memory mapped support
607 CONFIG_CMD_MII * MII utility commands
608 CONFIG_CMD_NAND * NAND support
609 CONFIG_CMD_NET bootp, tftpboot, rarpboot
610 CONFIG_CMD_PCI * pciinfo
611 CONFIG_CMD_PCMCIA * PCMCIA support
612 CONFIG_CMD_PING * send ICMP ECHO_REQUEST to network
614 CONFIG_CMD_PORTIO * Port I/O
615 CONFIG_CMD_REGINFO * Register dump
616 CONFIG_CMD_RUN run command in env variable
617 CONFIG_CMD_SAVES * save S record dump
618 CONFIG_CMD_SCSI * SCSI Support
619 CONFIG_CMD_SDRAM * print SDRAM configuration information
620 (requires CONFIG_CMD_I2C)
621 CONFIG_CMD_SETGETDCR Support for DCR Register access
623 CONFIG_CMD_SPI * SPI serial bus support
624 CONFIG_CMD_USB * USB support
625 CONFIG_CMD_VFD * VFD support (TRAB)
626 CONFIG_CMD_BSP * Board SPecific functions
627 CONFIG_CMD_CDP * Cisco Discover Protocol support
628 CONFIG_CMD_FSL * Microblaze FSL support
631 EXAMPLE: If you want all functions except of network
632 support you can write:
634 #include "config_cmd_all.h"
635 #undef CONFIG_CMD_NET
638 fdt (flattened device tree) command: CONFIG_OF_LIBFDT
640 Note: Don't enable the "icache" and "dcache" commands
641 (configuration option CONFIG_CMD_CACHE) unless you know
642 what you (and your U-Boot users) are doing. Data
643 cache cannot be enabled on systems like the 8xx or
644 8260 (where accesses to the IMMR region must be
645 uncached), and it cannot be disabled on all other
646 systems where we (mis-) use the data cache to hold an
647 initial stack and some data.
650 XXX - this list needs to get updated!
654 If this variable is defined, it enables watchdog
655 support. There must be support in the platform specific
656 code for a watchdog. For the 8xx and 8260 CPUs, the
657 SIU Watchdog feature is enabled in the SYPCR
661 CONFIG_VERSION_VARIABLE
662 If this variable is defined, an environment variable
663 named "ver" is created by U-Boot showing the U-Boot
664 version as printed by the "version" command.
665 This variable is readonly.
669 When CONFIG_CMD_DATE is selected, the type of the RTC
670 has to be selected, too. Define exactly one of the
673 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx
674 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC
675 CONFIG_RTC_MC146818 - use MC146818 RTC
676 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC
677 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC
678 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC
679 CONFIG_RTC_DS164x - use Dallas DS164x RTC
680 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC
681 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC
682 CFG_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337
684 Note that if the RTC uses I2C, then the I2C interface
685 must also be configured. See I2C Support, below.
689 When CONFIG_TIMESTAMP is selected, the timestamp
690 (date and time) of an image is printed by image
691 commands like bootm or iminfo. This option is
692 automatically enabled when you select CONFIG_CMD_DATE .
695 CONFIG_MAC_PARTITION and/or CONFIG_DOS_PARTITION
696 and/or CONFIG_ISO_PARTITION
698 If IDE or SCSI support is enabled (CONFIG_CMD_IDE or
699 CONFIG_CMD_SCSI) you must configure support for at
700 least one partition type as well.
703 CONFIG_IDE_RESET_ROUTINE - this is defined in several
704 board configurations files but used nowhere!
706 CONFIG_IDE_RESET - is this is defined, IDE Reset will
707 be performed by calling the function
708 ide_set_reset(int reset)
709 which has to be defined in a board specific file
714 Set this to enable ATAPI support.
719 Set this to enable support for disks larger than 137GB
720 Also look at CFG_64BIT_LBA ,CFG_64BIT_VSPRINTF and CFG_64BIT_STRTOUL
721 Whithout these , LBA48 support uses 32bit variables and will 'only'
722 support disks up to 2.1TB.
725 When enabled, makes the IDE subsystem use 64bit sector addresses.
729 At the moment only there is only support for the
730 SYM53C8XX SCSI controller; define
731 CONFIG_SCSI_SYM53C8XX to enable it.
733 CFG_SCSI_MAX_LUN [8], CFG_SCSI_MAX_SCSI_ID [7] and
734 CFG_SCSI_MAX_DEVICE [CFG_SCSI_MAX_SCSI_ID *
735 CFG_SCSI_MAX_LUN] can be adjusted to define the
736 maximum numbers of LUNs, SCSI ID's and target
738 CFG_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz)
740 - NETWORK Support (PCI):
742 Support for Intel 8254x gigabit chips.
744 CONFIG_E1000_FALLBACK_MAC
745 default MAC for empty eeprom after production.
748 Support for Intel 82557/82559/82559ER chips.
749 Optional CONFIG_EEPRO100_SROM_WRITE enables eeprom
750 write routine for first time initialisation.
753 Support for Digital 2114x chips.
754 Optional CONFIG_TULIP_SELECT_MEDIA for board specific
755 modem chip initialisation (KS8761/QS6611).
758 Support for National dp83815 chips.
761 Support for National dp8382[01] gigabit chips.
763 - NETWORK Support (other):
765 CONFIG_DRIVER_LAN91C96
766 Support for SMSC's LAN91C96 chips.
769 Define this to hold the physical address
770 of the LAN91C96's I/O space
772 CONFIG_LAN91C96_USE_32_BIT
773 Define this to enable 32 bit addressing
775 CONFIG_DRIVER_SMC91111
776 Support for SMSC's LAN91C111 chip
779 Define this to hold the physical address
780 of the device (I/O space)
782 CONFIG_SMC_USE_32_BIT
783 Define this if data bus is 32 bits
785 CONFIG_SMC_USE_IOFUNCS
786 Define this to use i/o functions instead of macros
787 (some hardware wont work with macros)
790 At the moment only the UHCI host controller is
791 supported (PIP405, MIP405, MPC5200); define
792 CONFIG_USB_UHCI to enable it.
793 define CONFIG_USB_KEYBOARD to enable the USB Keyboard
794 and define CONFIG_USB_STORAGE to enable the USB
797 Supported are USB Keyboards and USB Floppy drives
799 MPC5200 USB requires additional defines:
801 for 528 MHz Clock: 0x0001bbbb
803 for differential drivers: 0x00001000
804 for single ended drivers: 0x00005000
806 May be defined to allow interrupt polling
807 instead of using asynchronous interrupts
810 Define the below if you wish to use the USB console.
811 Once firmware is rebuilt from a serial console issue the
812 command "setenv stdin usbtty; setenv stdout usbtty" and
813 attach your usb cable. The Unix command "dmesg" should print
814 it has found a new device. The environment variable usbtty
815 can be set to gserial or cdc_acm to enable your device to
816 appear to a USB host as a Linux gserial device or a
817 Common Device Class Abstract Control Model serial device.
818 If you select usbtty = gserial you should be able to enumerate
820 # modprobe usbserial vendor=0xVendorID product=0xProductID
821 else if using cdc_acm, simply setting the environment
822 variable usbtty to be cdc_acm should suffice. The following
823 might be defined in YourBoardName.h
826 Define this to build a UDC device
829 Define this to have a tty type of device available to
830 talk to the UDC device
832 CFG_CONSOLE_IS_IN_ENV
833 Define this if you want stdin, stdout &/or stderr to
837 CFG_USB_EXTC_CLK 0xBLAH
838 Derive USB clock from external clock "blah"
839 - CFG_USB_EXTC_CLK 0x02
841 CFG_USB_BRG_CLK 0xBLAH
842 Derive USB clock from brgclk
843 - CFG_USB_BRG_CLK 0x04
845 If you have a USB-IF assigned VendorID then you may wish to
846 define your own vendor specific values either in BoardName.h
847 or directly in usbd_vendor_info.h. If you don't define
848 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME,
849 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot
850 should pretend to be a Linux device to it's target host.
852 CONFIG_USBD_MANUFACTURER
853 Define this string as the name of your company for
854 - CONFIG_USBD_MANUFACTURER "my company"
856 CONFIG_USBD_PRODUCT_NAME
857 Define this string as the name of your product
858 - CONFIG_USBD_PRODUCT_NAME "acme usb device"
861 Define this as your assigned Vendor ID from the USB
862 Implementors Forum. This *must* be a genuine Vendor ID
863 to avoid polluting the USB namespace.
864 - CONFIG_USBD_VENDORID 0xFFFF
866 CONFIG_USBD_PRODUCTID
867 Define this as the unique Product ID
869 - CONFIG_USBD_PRODUCTID 0xFFFF
873 The MMC controller on the Intel PXA is supported. To
874 enable this define CONFIG_MMC. The MMC can be
875 accessed from the boot prompt by mapping the device
876 to physical memory similar to flash. Command line is
877 enabled with CONFIG_CMD_MMC. The MMC driver also works with
878 the FAT fs. This is enabled with CONFIG_CMD_FAT.
880 - Journaling Flash filesystem support:
881 CONFIG_JFFS2_NAND, CONFIG_JFFS2_NAND_OFF, CONFIG_JFFS2_NAND_SIZE,
882 CONFIG_JFFS2_NAND_DEV
883 Define these for a default partition on a NAND device
885 CFG_JFFS2_FIRST_SECTOR,
886 CFG_JFFS2_FIRST_BANK, CFG_JFFS2_NUM_BANKS
887 Define these for a default partition on a NOR device
890 Define this to create an own partition. You have to provide a
891 function struct part_info* jffs2_part_info(int part_num)
893 If you define only one JFFS2 partition you may also want to
894 #define CFG_JFFS_SINGLE_PART 1
895 to disable the command chpart. This is the default when you
896 have not defined a custom partition
901 Define this to enable standard (PC-Style) keyboard
905 Standard PC keyboard driver with US (is default) and
906 GERMAN key layout (switch via environment 'keymap=de') support.
907 Export function i8042_kbd_init, i8042_tstc and i8042_getc
908 for cfb_console. Supports cursor blinking.
913 Define this to enable video support (for output to
918 Enable Chips & Technologies 69000 Video chip
920 CONFIG_VIDEO_SMI_LYNXEM
921 Enable Silicon Motion SMI 712/710/810 Video chip. The
922 video output is selected via environment 'videoout'
923 (1 = LCD and 2 = CRT). If videoout is undefined, CRT is
926 For the CT69000 and SMI_LYNXEM drivers, videomode is
927 selected via environment 'videomode'. Two diferent ways
929 - "videomode=num" 'num' is a standard LiLo mode numbers.
930 Following standard modes are supported (* is default):
932 Colors 640x480 800x600 1024x768 1152x864 1280x1024
933 -------------+---------------------------------------------
934 8 bits | 0x301* 0x303 0x305 0x161 0x307
935 15 bits | 0x310 0x313 0x316 0x162 0x319
936 16 bits | 0x311 0x314 0x317 0x163 0x31A
937 24 bits | 0x312 0x315 0x318 ? 0x31B
938 -------------+---------------------------------------------
939 (i.e. setenv videomode 317; saveenv; reset;)
941 - "videomode=bootargs" all the video parameters are parsed
942 from the bootargs. (See drivers/video/videomodes.c)
945 CONFIG_VIDEO_SED13806
946 Enable Epson SED13806 driver. This driver supports 8bpp
947 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP
948 or CONFIG_VIDEO_SED13806_16BPP
953 Define this to enable a custom keyboard support.
954 This simply calls drv_keyboard_init() which must be
955 defined in your board-specific files.
956 The only board using this so far is RBC823.
958 - LCD Support: CONFIG_LCD
960 Define this to enable LCD support (for output to LCD
961 display); also select one of the supported displays
962 by defining one of these:
964 CONFIG_NEC_NL6448AC33:
966 NEC NL6448AC33-18. Active, color, single scan.
968 CONFIG_NEC_NL6448BC20
970 NEC NL6448BC20-08. 6.5", 640x480.
971 Active, color, single scan.
973 CONFIG_NEC_NL6448BC33_54
975 NEC NL6448BC33-54. 10.4", 640x480.
976 Active, color, single scan.
980 Sharp 320x240. Active, color, single scan.
981 It isn't 16x9, and I am not sure what it is.
983 CONFIG_SHARP_LQ64D341
985 Sharp LQ64D341 display, 640x480.
986 Active, color, single scan.
990 HLD1045 display, 640x480.
991 Active, color, single scan.
995 Optrex CBL50840-2 NF-FW 99 22 M5
997 Hitachi LMG6912RPFC-00T
1001 320x240. Black & white.
1003 Normally display is black on white background; define
1004 CFG_WHITE_ON_BLACK to get it inverted.
1006 - Splash Screen Support: CONFIG_SPLASH_SCREEN
1008 If this option is set, the environment is checked for
1009 a variable "splashimage". If found, the usual display
1010 of logo, copyright and system information on the LCD
1011 is suppressed and the BMP image at the address
1012 specified in "splashimage" is loaded instead. The
1013 console is redirected to the "nulldev", too. This
1014 allows for a "silent" boot where a splash screen is
1015 loaded very quickly after power-on.
1017 - Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP
1019 If this option is set, additionally to standard BMP
1020 images, gzipped BMP images can be displayed via the
1021 splashscreen support or the bmp command.
1023 - Compression support:
1026 If this option is set, support for bzip2 compressed
1027 images is included. If not, only uncompressed and gzip
1028 compressed images are supported.
1030 NOTE: the bzip2 algorithm requires a lot of RAM, so
1031 the malloc area (as defined by CFG_MALLOC_LEN) should
1037 The address of PHY on MII bus.
1039 CONFIG_PHY_CLOCK_FREQ (ppc4xx)
1041 The clock frequency of the MII bus
1045 If this option is set, support for speed/duplex
1046 detection of Gigabit PHY is included.
1048 CONFIG_PHY_RESET_DELAY
1050 Some PHY like Intel LXT971A need extra delay after
1051 reset before any MII register access is possible.
1052 For such PHY, set this option to the usec delay
1053 required. (minimum 300usec for LXT971A)
1055 CONFIG_PHY_CMD_DELAY (ppc4xx)
1057 Some PHY like Intel LXT971A need extra delay after
1058 command issued before MII status register can be read
1065 Define a default value for ethernet address to use
1066 for the respective ethernet interface, in case this
1067 is not determined automatically.
1072 Define a default value for the IP address to use for
1073 the default ethernet interface, in case this is not
1074 determined through e.g. bootp.
1076 - Server IP address:
1079 Defines a default value for theIP address of a TFTP
1080 server to contact when using the "tftboot" command.
1082 - Multicast TFTP Mode:
1085 Defines whether you want to support multicast TFTP as per
1086 rfc-2090; for example to work with atftp. Lets lots of targets
1087 tftp down the same boot image concurrently. Note: the ethernet
1088 driver in use must provide a function: mcast() to join/leave a
1091 CONFIG_BOOTP_RANDOM_DELAY
1092 - BOOTP Recovery Mode:
1093 CONFIG_BOOTP_RANDOM_DELAY
1095 If you have many targets in a network that try to
1096 boot using BOOTP, you may want to avoid that all
1097 systems send out BOOTP requests at precisely the same
1098 moment (which would happen for instance at recovery
1099 from a power failure, when all systems will try to
1100 boot, thus flooding the BOOTP server. Defining
1101 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
1102 inserted before sending out BOOTP requests. The
1103 following delays are inserted then:
1105 1st BOOTP request: delay 0 ... 1 sec
1106 2nd BOOTP request: delay 0 ... 2 sec
1107 3rd BOOTP request: delay 0 ... 4 sec
1109 BOOTP requests: delay 0 ... 8 sec
1111 - DHCP Advanced Options:
1112 You can fine tune the DHCP functionality by defining
1113 CONFIG_BOOTP_* symbols:
1115 CONFIG_BOOTP_SUBNETMASK
1116 CONFIG_BOOTP_GATEWAY
1117 CONFIG_BOOTP_HOSTNAME
1118 CONFIG_BOOTP_NISDOMAIN
1119 CONFIG_BOOTP_BOOTPATH
1120 CONFIG_BOOTP_BOOTFILESIZE
1123 CONFIG_BOOTP_SEND_HOSTNAME
1124 CONFIG_BOOTP_NTPSERVER
1125 CONFIG_BOOTP_TIMEOFFSET
1126 CONFIG_BOOTP_VENDOREX
1128 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip
1129 environment variable, not the BOOTP server.
1131 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS
1132 serverip from a DHCP server, it is possible that more
1133 than one DNS serverip is offered to the client.
1134 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS
1135 serverip will be stored in the additional environment
1136 variable "dnsip2". The first DNS serverip is always
1137 stored in the variable "dnsip", when CONFIG_BOOTP_DNS
1140 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable
1141 to do a dynamic update of a DNS server. To do this, they
1142 need the hostname of the DHCP requester.
1143 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content
1144 of the "hostname" environment variable is passed as
1145 option 12 to the DHCP server.
1147 CONFIG_BOOTP_DHCP_REQUEST_DELAY
1149 A 32bit value in microseconds for a delay between
1150 receiving a "DHCP Offer" and sending the "DHCP Request".
1151 This fixes a problem with certain DHCP servers that don't
1152 respond 100% of the time to a "DHCP request". E.g. On an
1153 AT91RM9200 processor running at 180MHz, this delay needed
1154 to be *at least* 15,000 usec before a Windows Server 2003
1155 DHCP server would reply 100% of the time. I recommend at
1156 least 50,000 usec to be safe. The alternative is to hope
1157 that one of the retries will be successful but note that
1158 the DHCP timeout and retry process takes a longer than
1162 CONFIG_CDP_DEVICE_ID
1164 The device id used in CDP trigger frames.
1166 CONFIG_CDP_DEVICE_ID_PREFIX
1168 A two character string which is prefixed to the MAC address
1173 A printf format string which contains the ascii name of
1174 the port. Normally is set to "eth%d" which sets
1175 eth0 for the first ethernet, eth1 for the second etc.
1177 CONFIG_CDP_CAPABILITIES
1179 A 32bit integer which indicates the device capabilities;
1180 0x00000010 for a normal host which does not forwards.
1184 An ascii string containing the version of the software.
1188 An ascii string containing the name of the platform.
1192 A 32bit integer sent on the trigger.
1194 CONFIG_CDP_POWER_CONSUMPTION
1196 A 16bit integer containing the power consumption of the
1197 device in .1 of milliwatts.
1199 CONFIG_CDP_APPLIANCE_VLAN_TYPE
1201 A byte containing the id of the VLAN.
1203 - Status LED: CONFIG_STATUS_LED
1205 Several configurations allow to display the current
1206 status using a LED. For instance, the LED will blink
1207 fast while running U-Boot code, stop blinking as
1208 soon as a reply to a BOOTP request was received, and
1209 start blinking slow once the Linux kernel is running
1210 (supported by a status LED driver in the Linux
1211 kernel). Defining CONFIG_STATUS_LED enables this
1214 - CAN Support: CONFIG_CAN_DRIVER
1216 Defining CONFIG_CAN_DRIVER enables CAN driver support
1217 on those systems that support this (optional)
1218 feature, like the TQM8xxL modules.
1220 - I2C Support: CONFIG_HARD_I2C | CONFIG_SOFT_I2C
1222 These enable I2C serial bus commands. Defining either of
1223 (but not both of) CONFIG_HARD_I2C or CONFIG_SOFT_I2C will
1224 include the appropriate I2C driver for the selected cpu.
1226 This will allow you to use i2c commands at the u-boot
1227 command line (as long as you set CONFIG_CMD_I2C in
1228 CONFIG_COMMANDS) and communicate with i2c based realtime
1229 clock chips. See common/cmd_i2c.c for a description of the
1230 command line interface.
1232 CONFIG_I2C_CMD_TREE is a recommended option that places
1233 all I2C commands under a single 'i2c' root command. The
1234 older 'imm', 'imd', 'iprobe' etc. commands are considered
1235 deprecated and may disappear in the future.
1237 CONFIG_HARD_I2C selects a hardware I2C controller.
1239 CONFIG_SOFT_I2C configures u-boot to use a software (aka
1240 bit-banging) driver instead of CPM or similar hardware
1243 There are several other quantities that must also be
1244 defined when you define CONFIG_HARD_I2C or CONFIG_SOFT_I2C.
1246 In both cases you will need to define CFG_I2C_SPEED
1247 to be the frequency (in Hz) at which you wish your i2c bus
1248 to run and CFG_I2C_SLAVE to be the address of this node (ie
1249 the cpu's i2c node address).
1251 Now, the u-boot i2c code for the mpc8xx (cpu/mpc8xx/i2c.c)
1252 sets the cpu up as a master node and so its address should
1253 therefore be cleared to 0 (See, eg, MPC823e User's Manual
1254 p.16-473). So, set CFG_I2C_SLAVE to 0.
1256 That's all that's required for CONFIG_HARD_I2C.
1258 If you use the software i2c interface (CONFIG_SOFT_I2C)
1259 then the following macros need to be defined (examples are
1260 from include/configs/lwmon.h):
1264 (Optional). Any commands necessary to enable the I2C
1265 controller or configure ports.
1267 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
1271 (Only for MPC8260 CPU). The I/O port to use (the code
1272 assumes both bits are on the same port). Valid values
1273 are 0..3 for ports A..D.
1277 The code necessary to make the I2C data line active
1278 (driven). If the data line is open collector, this
1281 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
1285 The code necessary to make the I2C data line tri-stated
1286 (inactive). If the data line is open collector, this
1289 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
1293 Code that returns TRUE if the I2C data line is high,
1296 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
1300 If <bit> is TRUE, sets the I2C data line high. If it
1301 is FALSE, it clears it (low).
1303 eg: #define I2C_SDA(bit) \
1304 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
1305 else immr->im_cpm.cp_pbdat &= ~PB_SDA
1309 If <bit> is TRUE, sets the I2C clock line high. If it
1310 is FALSE, it clears it (low).
1312 eg: #define I2C_SCL(bit) \
1313 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
1314 else immr->im_cpm.cp_pbdat &= ~PB_SCL
1318 This delay is invoked four times per clock cycle so this
1319 controls the rate of data transfer. The data rate thus
1320 is 1 / (I2C_DELAY * 4). Often defined to be something
1323 #define I2C_DELAY udelay(2)
1327 When a board is reset during an i2c bus transfer
1328 chips might think that the current transfer is still
1329 in progress. On some boards it is possible to access
1330 the i2c SCLK line directly, either by using the
1331 processor pin as a GPIO or by having a second pin
1332 connected to the bus. If this option is defined a
1333 custom i2c_init_board() routine in boards/xxx/board.c
1334 is run early in the boot sequence.
1336 CONFIG_I2CFAST (PPC405GP|PPC405EP only)
1338 This option enables configuration of bi_iic_fast[] flags
1339 in u-boot bd_info structure based on u-boot environment
1340 variable "i2cfast". (see also i2cfast)
1342 CONFIG_I2C_MULTI_BUS
1344 This option allows the use of multiple I2C buses, each of which
1345 must have a controller. At any point in time, only one bus is
1346 active. To switch to a different bus, use the 'i2c dev' command.
1347 Note that bus numbering is zero-based.
1351 This option specifies a list of I2C devices that will be skipped
1352 when the 'i2c probe' command is issued (or 'iprobe' using the legacy
1353 command). If CONFIG_I2C_MULTI_BUS is set, specify a list of bus-device
1354 pairs. Otherwise, specify a 1D array of device addresses
1357 #undef CONFIG_I2C_MULTI_BUS
1358 #define CFG_I2C_NOPROBES {0x50,0x68}
1360 will skip addresses 0x50 and 0x68 on a board with one I2C bus
1362 #define CONFIG_I2C_MULTI_BUS
1363 #define CFG_I2C_MULTI_NOPROBES {{0,0x50},{0,0x68},{1,0x54}}
1365 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1
1369 If defined, then this indicates the I2C bus number for DDR SPD.
1370 If not defined, then U-Boot assumes that SPD is on I2C bus 0.
1374 If defined, then this indicates the I2C bus number for the RTC.
1375 If not defined, then U-Boot assumes that RTC is on I2C bus 0.
1379 If defined, then this indicates the I2C bus number for the DTT.
1380 If not defined, then U-Boot assumes that DTT is on I2C bus 0.
1384 Define this option if you want to use Freescale's I2C driver in
1385 drivers/i2c/fsl_i2c.c.
1388 - SPI Support: CONFIG_SPI
1390 Enables SPI driver (so far only tested with
1391 SPI EEPROM, also an instance works with Crystal A/D and
1392 D/As on the SACSng board)
1396 Enables extended (16-bit) SPI EEPROM addressing.
1397 (symmetrical to CONFIG_I2C_X)
1401 Enables a software (bit-bang) SPI driver rather than
1402 using hardware support. This is a general purpose
1403 driver that only requires three general I/O port pins
1404 (two outputs, one input) to function. If this is
1405 defined, the board configuration must define several
1406 SPI configuration items (port pins to use, etc). For
1407 an example, see include/configs/sacsng.h.
1411 Enables a hardware SPI driver for general-purpose reads
1412 and writes. As with CONFIG_SOFT_SPI, the board configuration
1413 must define a list of chip-select function pointers.
1414 Currently supported on some MPC8xxx processors. For an
1415 example, see include/configs/mpc8349emds.h.
1417 - FPGA Support: CONFIG_FPGA
1419 Enables FPGA subsystem.
1421 CONFIG_FPGA_<vendor>
1423 Enables support for specific chip vendors.
1426 CONFIG_FPGA_<family>
1428 Enables support for FPGA family.
1429 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX)
1433 Specify the number of FPGA devices to support.
1435 CFG_FPGA_PROG_FEEDBACK
1437 Enable printing of hash marks during FPGA configuration.
1441 Enable checks on FPGA configuration interface busy
1442 status by the configuration function. This option
1443 will require a board or device specific function to
1448 If defined, a function that provides delays in the FPGA
1449 configuration driver.
1451 CFG_FPGA_CHECK_CTRLC
1452 Allow Control-C to interrupt FPGA configuration
1454 CFG_FPGA_CHECK_ERROR
1456 Check for configuration errors during FPGA bitfile
1457 loading. For example, abort during Virtex II
1458 configuration if the INIT_B line goes low (which
1459 indicated a CRC error).
1463 Maximum time to wait for the INIT_B line to deassert
1464 after PROB_B has been deasserted during a Virtex II
1465 FPGA configuration sequence. The default time is 500
1470 Maximum time to wait for BUSY to deassert during
1471 Virtex II FPGA configuration. The default is 5 mS.
1473 CFG_FPGA_WAIT_CONFIG
1475 Time to wait after FPGA configuration. The default is
1478 - Configuration Management:
1481 If defined, this string will be added to the U-Boot
1482 version information (U_BOOT_VERSION)
1484 - Vendor Parameter Protection:
1486 U-Boot considers the values of the environment
1487 variables "serial#" (Board Serial Number) and
1488 "ethaddr" (Ethernet Address) to be parameters that
1489 are set once by the board vendor / manufacturer, and
1490 protects these variables from casual modification by
1491 the user. Once set, these variables are read-only,
1492 and write or delete attempts are rejected. You can
1493 change this behviour:
1495 If CONFIG_ENV_OVERWRITE is #defined in your config
1496 file, the write protection for vendor parameters is
1497 completely disabled. Anybody can change or delete
1500 Alternatively, if you #define _both_ CONFIG_ETHADDR
1501 _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
1502 ethernet address is installed in the environment,
1503 which can be changed exactly ONCE by the user. [The
1504 serial# is unaffected by this, i. e. it remains
1510 Define this variable to enable the reservation of
1511 "protected RAM", i. e. RAM which is not overwritten
1512 by U-Boot. Define CONFIG_PRAM to hold the number of
1513 kB you want to reserve for pRAM. You can overwrite
1514 this default value by defining an environment
1515 variable "pram" to the number of kB you want to
1516 reserve. Note that the board info structure will
1517 still show the full amount of RAM. If pRAM is
1518 reserved, a new environment variable "mem" will
1519 automatically be defined to hold the amount of
1520 remaining RAM in a form that can be passed as boot
1521 argument to Linux, for instance like that:
1523 setenv bootargs ... mem=\${mem}
1526 This way you can tell Linux not to use this memory,
1527 either, which results in a memory region that will
1528 not be affected by reboots.
1530 *WARNING* If your board configuration uses automatic
1531 detection of the RAM size, you must make sure that
1532 this memory test is non-destructive. So far, the
1533 following board configurations are known to be
1536 ETX094, IVMS8, IVML24, SPD8xx, TQM8xxL,
1537 HERMES, IP860, RPXlite, LWMON, LANTEC,
1538 PCU_E, FLAGADM, TQM8260
1543 Define this variable to stop the system in case of a
1544 fatal error, so that you have to reset it manually.
1545 This is probably NOT a good idea for an embedded
1546 system where you want to system to reboot
1547 automatically as fast as possible, but it may be
1548 useful during development since you can try to debug
1549 the conditions that lead to the situation.
1551 CONFIG_NET_RETRY_COUNT
1553 This variable defines the number of retries for
1554 network operations like ARP, RARP, TFTP, or BOOTP
1555 before giving up the operation. If not defined, a
1556 default value of 5 is used.
1558 - Command Interpreter:
1559 CONFIG_AUTO_COMPLETE
1561 Enable auto completion of commands using TAB.
1563 Note that this feature has NOT been implemented yet
1564 for the "hush" shell.
1569 Define this variable to enable the "hush" shell (from
1570 Busybox) as command line interpreter, thus enabling
1571 powerful command line syntax like
1572 if...then...else...fi conditionals or `&&' and '||'
1573 constructs ("shell scripts").
1575 If undefined, you get the old, much simpler behaviour
1576 with a somewhat smaller memory footprint.
1581 This defines the secondary prompt string, which is
1582 printed when the command interpreter needs more input
1583 to complete a command. Usually "> ".
1587 In the current implementation, the local variables
1588 space and global environment variables space are
1589 separated. Local variables are those you define by
1590 simply typing `name=value'. To access a local
1591 variable later on, you have write `$name' or
1592 `${name}'; to execute the contents of a variable
1593 directly type `$name' at the command prompt.
1595 Global environment variables are those you use
1596 setenv/printenv to work with. To run a command stored
1597 in such a variable, you need to use the run command,
1598 and you must not use the '$' sign to access them.
1600 To store commands and special characters in a
1601 variable, please use double quotation marks
1602 surrounding the whole text of the variable, instead
1603 of the backslashes before semicolons and special
1606 - Commandline Editing and History:
1607 CONFIG_CMDLINE_EDITING
1609 Enable editiong and History functions for interactive
1610 commandline input operations
1612 - Default Environment:
1613 CONFIG_EXTRA_ENV_SETTINGS
1615 Define this to contain any number of null terminated
1616 strings (variable = value pairs) that will be part of
1617 the default environment compiled into the boot image.
1619 For example, place something like this in your
1620 board's config file:
1622 #define CONFIG_EXTRA_ENV_SETTINGS \
1626 Warning: This method is based on knowledge about the
1627 internal format how the environment is stored by the
1628 U-Boot code. This is NOT an official, exported
1629 interface! Although it is unlikely that this format
1630 will change soon, there is no guarantee either.
1631 You better know what you are doing here.
1633 Note: overly (ab)use of the default environment is
1634 discouraged. Make sure to check other ways to preset
1635 the environment like the autoscript function or the
1638 - DataFlash Support:
1639 CONFIG_HAS_DATAFLASH
1641 Defining this option enables DataFlash features and
1642 allows to read/write in Dataflash via the standard
1645 - SystemACE Support:
1648 Adding this option adds support for Xilinx SystemACE
1649 chips attached via some sort of local bus. The address
1650 of the chip must alsh be defined in the
1651 CFG_SYSTEMACE_BASE macro. For example:
1653 #define CONFIG_SYSTEMACE
1654 #define CFG_SYSTEMACE_BASE 0xf0000000
1656 When SystemACE support is added, the "ace" device type
1657 becomes available to the fat commands, i.e. fatls.
1659 - TFTP Fixed UDP Port:
1662 If this is defined, the environment variable tftpsrcp
1663 is used to supply the TFTP UDP source port value.
1664 If tftpsrcp isn't defined, the normal pseudo-random port
1665 number generator is used.
1667 Also, the environment variable tftpdstp is used to supply
1668 the TFTP UDP destination port value. If tftpdstp isn't
1669 defined, the normal port 69 is used.
1671 The purpose for tftpsrcp is to allow a TFTP server to
1672 blindly start the TFTP transfer using the pre-configured
1673 target IP address and UDP port. This has the effect of
1674 "punching through" the (Windows XP) firewall, allowing
1675 the remainder of the TFTP transfer to proceed normally.
1676 A better solution is to properly configure the firewall,
1677 but sometimes that is not allowed.
1679 - Show boot progress:
1680 CONFIG_SHOW_BOOT_PROGRESS
1682 Defining this option allows to add some board-
1683 specific code (calling a user-provided function
1684 "show_boot_progress(int)") that enables you to show
1685 the system's boot progress on some display (for
1686 example, some LED's) on your board. At the moment,
1687 the following checkpoints are implemented:
1689 Legacy uImage format:
1692 1 common/cmd_bootm.c before attempting to boot an image
1693 -1 common/cmd_bootm.c Image header has bad magic number
1694 2 common/cmd_bootm.c Image header has correct magic number
1695 -2 common/cmd_bootm.c Image header has bad checksum
1696 3 common/cmd_bootm.c Image header has correct checksum
1697 -3 common/cmd_bootm.c Image data has bad checksum
1698 4 common/cmd_bootm.c Image data has correct checksum
1699 -4 common/cmd_bootm.c Image is for unsupported architecture
1700 5 common/cmd_bootm.c Architecture check OK
1701 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi)
1702 6 common/cmd_bootm.c Image Type check OK
1703 -6 common/cmd_bootm.c gunzip uncompression error
1704 -7 common/cmd_bootm.c Unimplemented compression type
1705 7 common/cmd_bootm.c Uncompression OK
1706 8 common/cmd_bootm.c No uncompress/copy overwrite error
1707 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX)
1709 9 common/image.c Start initial ramdisk verification
1710 -10 common/image.c Ramdisk header has bad magic number
1711 -11 common/image.c Ramdisk header has bad checksum
1712 10 common/image.c Ramdisk header is OK
1713 -12 common/image.c Ramdisk data has bad checksum
1714 11 common/image.c Ramdisk data has correct checksum
1715 12 common/image.c Ramdisk verification complete, start loading
1716 -13 common/image.c Wrong Image Type (not PPC Linux Ramdisk)
1717 13 common/image.c Start multifile image verification
1718 14 common/image.c No initial ramdisk, no multifile, continue.
1720 15 lib_<arch>/bootm.c All preparation done, transferring control to OS
1722 -30 lib_ppc/board.c Fatal error, hang the system
1723 -31 post/post.c POST test failed, detected by post_output_backlog()
1724 -32 post/post.c POST test failed, detected by post_run_single()
1726 34 common/cmd_doc.c before loading a Image from a DOC device
1727 -35 common/cmd_doc.c Bad usage of "doc" command
1728 35 common/cmd_doc.c correct usage of "doc" command
1729 -36 common/cmd_doc.c No boot device
1730 36 common/cmd_doc.c correct boot device
1731 -37 common/cmd_doc.c Unknown Chip ID on boot device
1732 37 common/cmd_doc.c correct chip ID found, device available
1733 -38 common/cmd_doc.c Read Error on boot device
1734 38 common/cmd_doc.c reading Image header from DOC device OK
1735 -39 common/cmd_doc.c Image header has bad magic number
1736 39 common/cmd_doc.c Image header has correct magic number
1737 -40 common/cmd_doc.c Error reading Image from DOC device
1738 40 common/cmd_doc.c Image header has correct magic number
1739 41 common/cmd_ide.c before loading a Image from a IDE device
1740 -42 common/cmd_ide.c Bad usage of "ide" command
1741 42 common/cmd_ide.c correct usage of "ide" command
1742 -43 common/cmd_ide.c No boot device
1743 43 common/cmd_ide.c boot device found
1744 -44 common/cmd_ide.c Device not available
1745 44 common/cmd_ide.c Device available
1746 -45 common/cmd_ide.c wrong partition selected
1747 45 common/cmd_ide.c partition selected
1748 -46 common/cmd_ide.c Unknown partition table
1749 46 common/cmd_ide.c valid partition table found
1750 -47 common/cmd_ide.c Invalid partition type
1751 47 common/cmd_ide.c correct partition type
1752 -48 common/cmd_ide.c Error reading Image Header on boot device
1753 48 common/cmd_ide.c reading Image Header from IDE device OK
1754 -49 common/cmd_ide.c Image header has bad magic number
1755 49 common/cmd_ide.c Image header has correct magic number
1756 -50 common/cmd_ide.c Image header has bad checksum
1757 50 common/cmd_ide.c Image header has correct checksum
1758 -51 common/cmd_ide.c Error reading Image from IDE device
1759 51 common/cmd_ide.c reading Image from IDE device OK
1760 52 common/cmd_nand.c before loading a Image from a NAND device
1761 -53 common/cmd_nand.c Bad usage of "nand" command
1762 53 common/cmd_nand.c correct usage of "nand" command
1763 -54 common/cmd_nand.c No boot device
1764 54 common/cmd_nand.c boot device found
1765 -55 common/cmd_nand.c Unknown Chip ID on boot device
1766 55 common/cmd_nand.c correct chip ID found, device available
1767 -56 common/cmd_nand.c Error reading Image Header on boot device
1768 56 common/cmd_nand.c reading Image Header from NAND device OK
1769 -57 common/cmd_nand.c Image header has bad magic number
1770 57 common/cmd_nand.c Image header has correct magic number
1771 -58 common/cmd_nand.c Error reading Image from NAND device
1772 58 common/cmd_nand.c reading Image from NAND device OK
1774 -60 common/env_common.c Environment has a bad CRC, using default
1776 64 net/eth.c starting with Ethernetconfiguration.
1777 -64 net/eth.c no Ethernet found.
1778 65 net/eth.c Ethernet found.
1780 -80 common/cmd_net.c usage wrong
1781 80 common/cmd_net.c before calling NetLoop()
1782 -81 common/cmd_net.c some error in NetLoop() occured
1783 81 common/cmd_net.c NetLoop() back without error
1784 -82 common/cmd_net.c size == 0 (File with size 0 loaded)
1785 82 common/cmd_net.c trying automatic boot
1786 83 common/cmd_net.c running autoscript
1787 -83 common/cmd_net.c some error in automatic boot or autoscript
1788 84 common/cmd_net.c end without errors
1793 100 common/cmd_bootm.c Kernel FIT Image has correct format
1794 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format
1795 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration
1796 -101 common/cmd_bootm.c Can't get configuration for kernel subimage
1797 102 common/cmd_bootm.c Kernel unit name specified
1798 -103 common/cmd_bootm.c Can't get kernel subimage node offset
1799 103 common/cmd_bootm.c Found configuration node
1800 104 common/cmd_bootm.c Got kernel subimage node offset
1801 -104 common/cmd_bootm.c Kernel subimage hash verification failed
1802 105 common/cmd_bootm.c Kernel subimage hash verification OK
1803 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture
1804 106 common/cmd_bootm.c Architecture check OK
1805 -106 common/cmd_bootm.c Kernel subimage has wrong typea
1806 107 common/cmd_bootm.c Kernel subimge type OK
1807 -107 common/cmd_bootm.c Can't get kernel subimage data/size
1808 108 common/cmd_bootm.c Got kernel subimage data/size
1809 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT)
1810 -109 common/cmd_bootm.c Can't get kernel subimage type
1811 -110 common/cmd_bootm.c Can't get kernel subimage comp
1812 -111 common/cmd_bootm.c Can't get kernel subimage os
1813 -112 common/cmd_bootm.c Can't get kernel subimage load address
1814 -113 common/cmd_bootm.c Image uncompress/copy overwrite error
1816 120 common/image.c Start initial ramdisk verification
1817 -120 common/image.c Ramdisk FIT image has incorrect format
1818 121 common/image.c Ramdisk FIT image has correct format
1819 122 common/image.c No Ramdisk subimage unit name, using configuration
1820 -122 common/image.c Can't get configuration for ramdisk subimage
1821 123 common/image.c Ramdisk unit name specified
1822 -124 common/image.c Can't get ramdisk subimage node offset
1823 125 common/image.c Got ramdisk subimage node offset
1824 -125 common/image.c Ramdisk subimage hash verification failed
1825 126 common/image.c Ramdisk subimage hash verification OK
1826 -126 common/image.c Ramdisk subimage for unsupported architecture
1827 127 common/image.c Architecture check OK
1828 -127 common/image.c Can't get ramdisk subimage data/size
1829 128 common/image.c Got ramdisk subimage data/size
1830 129 common/image.c Can't get ramdisk load address
1831 -129 common/image.c Got ramdisk load address
1833 -130 common/cmd_doc.c Icorrect FIT image format
1834 131 common/cmd_doc.c FIT image format OK
1836 -140 common/cmd_ide.c Icorrect FIT image format
1837 141 common/cmd_ide.c FIT image format OK
1839 -150 common/cmd_nand.c Icorrect FIT image format
1840 151 common/cmd_nand.c FIT image format OK
1846 [so far only for SMDK2400 and TRAB boards]
1848 - Modem support endable:
1849 CONFIG_MODEM_SUPPORT
1851 - RTS/CTS Flow control enable:
1854 - Modem debug support:
1855 CONFIG_MODEM_SUPPORT_DEBUG
1857 Enables debugging stuff (char screen[1024], dbg())
1858 for modem support. Useful only with BDI2000.
1860 - Interrupt support (PPC):
1862 There are common interrupt_init() and timer_interrupt()
1863 for all PPC archs. interrupt_init() calls interrupt_init_cpu()
1864 for cpu specific initialization. interrupt_init_cpu()
1865 should set decrementer_count to appropriate value. If
1866 cpu resets decrementer automatically after interrupt
1867 (ppc4xx) it should set decrementer_count to zero.
1868 timer_interrupt() calls timer_interrupt_cpu() for cpu
1869 specific handling. If board has watchdog / status_led
1870 / other_activity_monitor it works automatically from
1871 general timer_interrupt().
1875 In the target system modem support is enabled when a
1876 specific key (key combination) is pressed during
1877 power-on. Otherwise U-Boot will boot normally
1878 (autoboot). The key_pressed() fuction is called from
1879 board_init(). Currently key_pressed() is a dummy
1880 function, returning 1 and thus enabling modem
1883 If there are no modem init strings in the
1884 environment, U-Boot proceed to autoboot; the
1885 previous output (banner, info printfs) will be
1888 See also: doc/README.Modem
1891 Configuration Settings:
1892 -----------------------
1894 - CFG_LONGHELP: Defined when you want long help messages included;
1895 undefine this when you're short of memory.
1897 - CFG_PROMPT: This is what U-Boot prints on the console to
1898 prompt for user input.
1900 - CFG_CBSIZE: Buffer size for input from the Console
1902 - CFG_PBSIZE: Buffer size for Console output
1904 - CFG_MAXARGS: max. Number of arguments accepted for monitor commands
1906 - CFG_BARGSIZE: Buffer size for Boot Arguments which are passed to
1907 the application (usually a Linux kernel) when it is
1910 - CFG_BAUDRATE_TABLE:
1911 List of legal baudrate settings for this board.
1913 - CFG_CONSOLE_INFO_QUIET
1914 Suppress display of console information at boot.
1916 - CFG_CONSOLE_IS_IN_ENV
1917 If the board specific function
1918 extern int overwrite_console (void);
1919 returns 1, the stdin, stderr and stdout are switched to the
1920 serial port, else the settings in the environment are used.
1922 - CFG_CONSOLE_OVERWRITE_ROUTINE
1923 Enable the call to overwrite_console().
1925 - CFG_CONSOLE_ENV_OVERWRITE
1926 Enable overwrite of previous console environment settings.
1928 - CFG_MEMTEST_START, CFG_MEMTEST_END:
1929 Begin and End addresses of the area used by the
1933 Enable an alternate, more extensive memory test.
1935 - CFG_MEMTEST_SCRATCH:
1936 Scratch address used by the alternate memory test
1937 You only need to set this if address zero isn't writeable
1939 - CFG_MEM_TOP_HIDE (PPC only):
1940 If CFG_MEM_TOP_HIDE is defined in the board config header,
1941 this specified memory area will get subtracted from the top
1942 (end) of ram and won't get "touched" at all by U-Boot. By
1943 fixing up gd->ram_size the Linux kernel should gets passed
1944 the now "corrected" memory size and won't touch it either.
1945 This should work for arch/ppc and arch/powerpc. Only Linux
1946 board ports in arch/powerpc with bootwrapper support that
1947 recalculate the memory size from the SDRAM controller setup
1948 will have to get fixed in Linux additionally.
1950 This option can be used as a workaround for the 440EPx/GRx
1951 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't
1954 WARNING: Please make sure that this value is a multiple of
1955 the Linux page size (normally 4k). If this is not the case,
1956 then the end address of the Linux memory will be located at a
1957 non page size aligned address and this could cause major
1960 - CFG_TFTP_LOADADDR:
1961 Default load address for network file downloads
1963 - CFG_LOADS_BAUD_CHANGE:
1964 Enable temporary baudrate change while serial download
1967 Physical start address of SDRAM. _Must_ be 0 here.
1970 Physical start address of Motherboard I/O (if using a
1974 Physical start address of Flash memory.
1977 Physical start address of boot monitor code (set by
1978 make config files to be same as the text base address
1979 (TEXT_BASE) used when linking) - same as
1980 CFG_FLASH_BASE when booting from flash.
1983 Size of memory reserved for monitor code, used to
1984 determine _at_compile_time_ (!) if the environment is
1985 embedded within the U-Boot image, or in a separate
1989 Size of DRAM reserved for malloc() use.
1992 Normally compressed uImages are limited to an
1993 uncompressed size of 8 MBytes. If this is not enough,
1994 you can define CFG_BOOTM_LEN in your board config file
1995 to adjust this setting to your needs.
1998 Maximum size of memory mapped by the startup code of
1999 the Linux kernel; all data that must be processed by
2000 the Linux kernel (bd_info, boot arguments, eventually
2001 initrd image) must be put below this limit.
2003 - CFG_MAX_FLASH_BANKS:
2004 Max number of Flash memory banks
2006 - CFG_MAX_FLASH_SECT:
2007 Max number of sectors on a Flash chip
2009 - CFG_FLASH_ERASE_TOUT:
2010 Timeout for Flash erase operations (in ms)
2012 - CFG_FLASH_WRITE_TOUT:
2013 Timeout for Flash write operations (in ms)
2015 - CFG_FLASH_LOCK_TOUT
2016 Timeout for Flash set sector lock bit operation (in ms)
2018 - CFG_FLASH_UNLOCK_TOUT
2019 Timeout for Flash clear lock bits operation (in ms)
2021 - CFG_FLASH_PROTECTION
2022 If defined, hardware flash sectors protection is used
2023 instead of U-Boot software protection.
2025 - CFG_DIRECT_FLASH_TFTP:
2027 Enable TFTP transfers directly to flash memory;
2028 without this option such a download has to be
2029 performed in two steps: (1) download to RAM, and (2)
2030 copy from RAM to flash.
2032 The two-step approach is usually more reliable, since
2033 you can check if the download worked before you erase
2034 the flash, but in some situations (when sytem RAM is
2035 too limited to allow for a tempory copy of the
2036 downloaded image) this option may be very useful.
2039 Define if the flash driver uses extra elements in the
2040 common flash structure for storing flash geometry.
2042 - CFG_FLASH_CFI_DRIVER
2043 This option also enables the building of the cfi_flash driver
2044 in the drivers directory
2046 - CFG_FLASH_QUIET_TEST
2047 If this option is defined, the common CFI flash doesn't
2048 print it's warning upon not recognized FLASH banks. This
2049 is useful, if some of the configured banks are only
2050 optionally available.
2052 - CONFIG_FLASH_SHOW_PROGRESS
2053 If defined (must be an integer), print out countdown
2054 digits and dots. Recommended value: 45 (9..1) for 80
2055 column displays, 15 (3..1) for 40 column displays.
2057 - CFG_RX_ETH_BUFFER:
2058 Defines the number of ethernet receive buffers. On some
2059 ethernet controllers it is recommended to set this value
2060 to 8 or even higher (EEPRO100 or 405 EMAC), since all
2061 buffers can be full shortly after enabling the interface
2062 on high ethernet traffic.
2063 Defaults to 4 if not defined.
2065 The following definitions that deal with the placement and management
2066 of environment data (variable area); in general, we support the
2067 following configurations:
2069 - CFG_ENV_IS_IN_FLASH:
2071 Define this if the environment is in flash memory.
2073 a) The environment occupies one whole flash sector, which is
2074 "embedded" in the text segment with the U-Boot code. This
2075 happens usually with "bottom boot sector" or "top boot
2076 sector" type flash chips, which have several smaller
2077 sectors at the start or the end. For instance, such a
2078 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In
2079 such a case you would place the environment in one of the
2080 4 kB sectors - with U-Boot code before and after it. With
2081 "top boot sector" type flash chips, you would put the
2082 environment in one of the last sectors, leaving a gap
2083 between U-Boot and the environment.
2087 Offset of environment data (variable area) to the
2088 beginning of flash memory; for instance, with bottom boot
2089 type flash chips the second sector can be used: the offset
2090 for this sector is given here.
2092 CFG_ENV_OFFSET is used relative to CFG_FLASH_BASE.
2096 This is just another way to specify the start address of
2097 the flash sector containing the environment (instead of
2100 - CFG_ENV_SECT_SIZE:
2102 Size of the sector containing the environment.
2105 b) Sometimes flash chips have few, equal sized, BIG sectors.
2106 In such a case you don't want to spend a whole sector for
2111 If you use this in combination with CFG_ENV_IS_IN_FLASH
2112 and CFG_ENV_SECT_SIZE, you can specify to use only a part
2113 of this flash sector for the environment. This saves
2114 memory for the RAM copy of the environment.
2116 It may also save flash memory if you decide to use this
2117 when your environment is "embedded" within U-Boot code,
2118 since then the remainder of the flash sector could be used
2119 for U-Boot code. It should be pointed out that this is
2120 STRONGLY DISCOURAGED from a robustness point of view:
2121 updating the environment in flash makes it always
2122 necessary to erase the WHOLE sector. If something goes
2123 wrong before the contents has been restored from a copy in
2124 RAM, your target system will be dead.
2126 - CFG_ENV_ADDR_REDUND
2129 These settings describe a second storage area used to hold
2130 a redundand copy of the environment data, so that there is
2131 a valid backup copy in case there is a power failure during
2132 a "saveenv" operation.
2134 BE CAREFUL! Any changes to the flash layout, and some changes to the
2135 source code will make it necessary to adapt <board>/u-boot.lds*
2139 - CFG_ENV_IS_IN_NVRAM:
2141 Define this if you have some non-volatile memory device
2142 (NVRAM, battery buffered SRAM) which you want to use for the
2148 These two #defines are used to determin the memory area you
2149 want to use for environment. It is assumed that this memory
2150 can just be read and written to, without any special
2153 BE CAREFUL! The first access to the environment happens quite early
2154 in U-Boot initalization (when we try to get the setting of for the
2155 console baudrate). You *MUST* have mappend your NVRAM area then, or
2158 Please note that even with NVRAM we still use a copy of the
2159 environment in RAM: we could work on NVRAM directly, but we want to
2160 keep settings there always unmodified except somebody uses "saveenv"
2161 to save the current settings.
2164 - CFG_ENV_IS_IN_EEPROM:
2166 Use this if you have an EEPROM or similar serial access
2167 device and a driver for it.
2172 These two #defines specify the offset and size of the
2173 environment area within the total memory of your EEPROM.
2175 - CFG_I2C_EEPROM_ADDR:
2176 If defined, specified the chip address of the EEPROM device.
2177 The default address is zero.
2179 - CFG_EEPROM_PAGE_WRITE_BITS:
2180 If defined, the number of bits used to address bytes in a
2181 single page in the EEPROM device. A 64 byte page, for example
2182 would require six bits.
2184 - CFG_EEPROM_PAGE_WRITE_DELAY_MS:
2185 If defined, the number of milliseconds to delay between
2186 page writes. The default is zero milliseconds.
2188 - CFG_I2C_EEPROM_ADDR_LEN:
2189 The length in bytes of the EEPROM memory array address. Note
2190 that this is NOT the chip address length!
2192 - CFG_I2C_EEPROM_ADDR_OVERFLOW:
2193 EEPROM chips that implement "address overflow" are ones
2194 like Catalyst 24WC04/08/16 which has 9/10/11 bits of
2195 address and the extra bits end up in the "chip address" bit
2196 slots. This makes a 24WC08 (1Kbyte) chip look like four 256
2199 Note that we consider the length of the address field to
2200 still be one byte because the extra address bits are hidden
2201 in the chip address.
2204 The size in bytes of the EEPROM device.
2207 - CFG_ENV_IS_IN_DATAFLASH:
2209 Define this if you have a DataFlash memory device which you
2210 want to use for the environment.
2216 These three #defines specify the offset and size of the
2217 environment area within the total memory of your DataFlash placed
2218 at the specified address.
2220 - CFG_ENV_IS_IN_NAND:
2222 Define this if you have a NAND device which you want to use
2223 for the environment.
2228 These two #defines specify the offset and size of the environment
2229 area within the first NAND device.
2231 - CFG_ENV_OFFSET_REDUND
2233 This setting describes a second storage area of CFG_ENV_SIZE
2234 size used to hold a redundant copy of the environment data,
2235 so that there is a valid backup copy in case there is a
2236 power failure during a "saveenv" operation.
2238 Note: CFG_ENV_OFFSET and CFG_ENV_OFFSET_REDUND must be aligned
2239 to a block boundary, and CFG_ENV_SIZE must be a multiple of
2240 the NAND devices block size.
2242 - CFG_SPI_INIT_OFFSET
2244 Defines offset to the initial SPI buffer area in DPRAM. The
2245 area is used at an early stage (ROM part) if the environment
2246 is configured to reside in the SPI EEPROM: We need a 520 byte
2247 scratch DPRAM area. It is used between the two initialization
2248 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems
2249 to be a good choice since it makes it far enough from the
2250 start of the data area as well as from the stack pointer.
2252 Please note that the environment is read-only until the monitor
2253 has been relocated to RAM and a RAM copy of the environment has been
2254 created; also, when using EEPROM you will have to use getenv_r()
2255 until then to read environment variables.
2257 The environment is protected by a CRC32 checksum. Before the monitor
2258 is relocated into RAM, as a result of a bad CRC you will be working
2259 with the compiled-in default environment - *silently*!!! [This is
2260 necessary, because the first environment variable we need is the
2261 "baudrate" setting for the console - if we have a bad CRC, we don't
2262 have any device yet where we could complain.]
2264 Note: once the monitor has been relocated, then it will complain if
2265 the default environment is used; a new CRC is computed as soon as you
2266 use the "saveenv" command to store a valid environment.
2268 - CFG_FAULT_ECHO_LINK_DOWN:
2269 Echo the inverted Ethernet link state to the fault LED.
2271 Note: If this option is active, then CFG_FAULT_MII_ADDR
2272 also needs to be defined.
2274 - CFG_FAULT_MII_ADDR:
2275 MII address of the PHY to check for the Ethernet link state.
2277 - CFG_64BIT_VSPRINTF:
2278 Makes vsprintf (and all *printf functions) support printing
2279 of 64bit values by using the L quantifier
2281 - CFG_64BIT_STRTOUL:
2282 Adds simple_strtoull that returns a 64bit value
2284 Low Level (hardware related) configuration options:
2285 ---------------------------------------------------
2287 - CFG_CACHELINE_SIZE:
2288 Cache Line Size of the CPU.
2291 Default address of the IMMR after system reset.
2293 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU,
2294 and RPXsuper) to be able to adjust the position of
2295 the IMMR register after a reset.
2297 - Floppy Disk Support:
2298 CFG_FDC_DRIVE_NUMBER
2300 the default drive number (default value 0)
2304 defines the spacing between fdc chipset registers
2309 defines the offset of register from address. It
2310 depends on which part of the data bus is connected to
2311 the fdc chipset. (default value 0)
2313 If CFG_ISA_IO_STRIDE CFG_ISA_IO_OFFSET and
2314 CFG_FDC_DRIVE_NUMBER are undefined, they take their
2317 if CFG_FDC_HW_INIT is defined, then the function
2318 fdc_hw_init() is called at the beginning of the FDC
2319 setup. fdc_hw_init() must be provided by the board
2320 source code. It is used to make hardware dependant
2323 - CFG_IMMR: Physical address of the Internal Memory.
2324 DO NOT CHANGE unless you know exactly what you're
2325 doing! (11-4) [MPC8xx/82xx systems only]
2327 - CFG_INIT_RAM_ADDR:
2329 Start address of memory area that can be used for
2330 initial data and stack; please note that this must be
2331 writable memory that is working WITHOUT special
2332 initialization, i. e. you CANNOT use normal RAM which
2333 will become available only after programming the
2334 memory controller and running certain initialization
2337 U-Boot uses the following memory types:
2338 - MPC8xx and MPC8260: IMMR (internal memory of the CPU)
2339 - MPC824X: data cache
2340 - PPC4xx: data cache
2342 - CFG_GBL_DATA_OFFSET:
2344 Offset of the initial data structure in the memory
2345 area defined by CFG_INIT_RAM_ADDR. Usually
2346 CFG_GBL_DATA_OFFSET is chosen such that the initial
2347 data is located at the end of the available space
2348 (sometimes written as (CFG_INIT_RAM_END -
2349 CFG_INIT_DATA_SIZE), and the initial stack is just
2350 below that area (growing from (CFG_INIT_RAM_ADDR +
2351 CFG_GBL_DATA_OFFSET) downward.
2354 On the MPC824X (or other systems that use the data
2355 cache for initial memory) the address chosen for
2356 CFG_INIT_RAM_ADDR is basically arbitrary - it must
2357 point to an otherwise UNUSED address space between
2358 the top of RAM and the start of the PCI space.
2360 - CFG_SIUMCR: SIU Module Configuration (11-6)
2362 - CFG_SYPCR: System Protection Control (11-9)
2364 - CFG_TBSCR: Time Base Status and Control (11-26)
2366 - CFG_PISCR: Periodic Interrupt Status and Control (11-31)
2368 - CFG_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30)
2370 - CFG_SCCR: System Clock and reset Control Register (15-27)
2372 - CFG_OR_TIMING_SDRAM:
2376 periodic timer for refresh
2378 - CFG_DER: Debug Event Register (37-47)
2380 - FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CFG_REMAP_OR_AM,
2381 CFG_PRELIM_OR_AM, CFG_OR_TIMING_FLASH, CFG_OR0_REMAP,
2382 CFG_OR0_PRELIM, CFG_BR0_PRELIM, CFG_OR1_REMAP, CFG_OR1_PRELIM,
2384 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
2386 - SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
2387 CFG_OR_TIMING_SDRAM, CFG_OR2_PRELIM, CFG_BR2_PRELIM,
2388 CFG_OR3_PRELIM, CFG_BR3_PRELIM:
2389 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
2391 - CFG_MAMR_PTA, CFG_MPTPR_2BK_4K, CFG_MPTPR_1BK_4K, CFG_MPTPR_2BK_8K,
2392 CFG_MPTPR_1BK_8K, CFG_MAMR_8COL, CFG_MAMR_9COL:
2393 Machine Mode Register and Memory Periodic Timer
2394 Prescaler definitions (SDRAM timing)
2396 - CFG_I2C_UCODE_PATCH, CFG_I2C_DPMEM_OFFSET [0x1FC0]:
2397 enable I2C microcode relocation patch (MPC8xx);
2398 define relocation offset in DPRAM [DSP2]
2400 - CFG_SMC_UCODE_PATCH, CFG_SMC_DPMEM_OFFSET [0x1FC0]:
2401 enable SMC microcode relocation patch (MPC8xx);
2402 define relocation offset in DPRAM [SMC1]
2404 - CFG_SPI_UCODE_PATCH, CFG_SPI_DPMEM_OFFSET [0x1FC0]:
2405 enable SPI microcode relocation patch (MPC8xx);
2406 define relocation offset in DPRAM [SCC4]
2409 Use OSCM clock mode on MBX8xx board. Be careful,
2410 wrong setting might damage your board. Read
2411 doc/README.MBX before setting this variable!
2413 - CFG_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only)
2414 Offset of the bootmode word in DPRAM used by post
2415 (Power On Self Tests). This definition overrides
2416 #define'd default value in commproc.h resp.
2419 - CFG_PCI_SLV_MEM_LOCAL, CFG_PCI_SLV_MEM_BUS, CFG_PICMR0_MASK_ATTRIB,
2420 CFG_PCI_MSTR0_LOCAL, CFG_PCIMSK0_MASK, CFG_PCI_MSTR1_LOCAL,
2421 CFG_PCIMSK1_MASK, CFG_PCI_MSTR_MEM_LOCAL, CFG_PCI_MSTR_MEM_BUS,
2422 CFG_CPU_PCI_MEM_START, CFG_PCI_MSTR_MEM_SIZE, CFG_POCMR0_MASK_ATTRIB,
2423 CFG_PCI_MSTR_MEMIO_LOCAL, CFG_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START,
2424 CFG_PCI_MSTR_MEMIO_SIZE, CFG_POCMR1_MASK_ATTRIB, CFG_PCI_MSTR_IO_LOCAL,
2425 CFG_PCI_MSTR_IO_BUS, CFG_CPU_PCI_IO_START, CFG_PCI_MSTR_IO_SIZE,
2426 CFG_POCMR2_MASK_ATTRIB: (MPC826x only)
2427 Overrides the default PCI memory map in cpu/mpc8260/pci.c if set.
2430 Get DDR timing information from an I2C EEPROM. Common
2431 with pluggable memory modules such as SODIMMs
2434 I2C address of the SPD EEPROM
2437 If SPD EEPROM is on an I2C bus other than the first
2438 one, specify here. Note that the value must resolve
2439 to something your driver can deal with.
2441 - CFG_83XX_DDR_USES_CS0
2442 Only for 83xx systems. If specified, then DDR should
2443 be configured using CS0 and CS1 instead of CS2 and CS3.
2445 - CFG_83XX_DDR_USES_CS0
2446 Only for 83xx systems. If specified, then DDR should
2447 be configured using CS0 and CS1 instead of CS2 and CS3.
2449 - CONFIG_ETHER_ON_FEC[12]
2450 Define to enable FEC[12] on a 8xx series processor.
2452 - CONFIG_FEC[12]_PHY
2453 Define to the hardcoded PHY address which corresponds
2454 to the given FEC; i. e.
2455 #define CONFIG_FEC1_PHY 4
2456 means that the PHY with address 4 is connected to FEC1
2458 When set to -1, means to probe for first available.
2460 - CONFIG_FEC[12]_PHY_NORXERR
2461 The PHY does not have a RXERR line (RMII only).
2462 (so program the FEC to ignore it).
2465 Enable RMII mode for all FECs.
2466 Note that this is a global option, we can't
2467 have one FEC in standard MII mode and another in RMII mode.
2469 - CONFIG_CRC32_VERIFY
2470 Add a verify option to the crc32 command.
2473 => crc32 -v <address> <count> <crc32>
2475 Where address/count indicate a memory area
2476 and crc32 is the correct crc32 which the
2480 Add the "loopw" memory command. This only takes effect if
2481 the memory commands are activated globally (CONFIG_CMD_MEM).
2484 Add the "mdc" and "mwc" memory commands. These are cyclic
2489 This command will print 4 bytes (10,11,12,13) each 500 ms.
2491 => mwc.l 100 12345678 10
2492 This command will write 12345678 to address 100 all 10 ms.
2494 This only takes effect if the memory commands are activated
2495 globally (CONFIG_CMD_MEM).
2497 - CONFIG_SKIP_LOWLEVEL_INIT
2498 - CONFIG_SKIP_RELOCATE_UBOOT
2500 [ARM only] If these variables are defined, then
2501 certain low level initializations (like setting up
2502 the memory controller) are omitted and/or U-Boot does
2503 not relocate itself into RAM.
2504 Normally these variables MUST NOT be defined. The
2505 only exception is when U-Boot is loaded (to RAM) by
2506 some other boot loader or by a debugger which
2507 performs these intializations itself.
2510 Building the Software:
2511 ======================
2513 Building U-Boot has been tested in several native build environments
2514 and in many different cross environments. Of course we cannot support
2515 all possibly existing versions of cross development tools in all
2516 (potentially obsolete) versions. In case of tool chain problems we
2517 recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK)
2518 which is extensively used to build and test U-Boot.
2520 If you are not using a native environment, it is assumed that you
2521 have GNU cross compiling tools available in your path. In this case,
2522 you must set the environment variable CROSS_COMPILE in your shell.
2523 Note that no changes to the Makefile or any other source files are
2524 necessary. For example using the ELDK on a 4xx CPU, please enter:
2526 $ CROSS_COMPILE=ppc_4xx-
2527 $ export CROSS_COMPILE
2529 U-Boot is intended to be simple to build. After installing the
2530 sources you must configure U-Boot for one specific board type. This
2535 where "NAME_config" is the name of one of the existing configu-
2536 rations; see the main Makefile for supported names.
2538 Note: for some board special configuration names may exist; check if
2539 additional information is available from the board vendor; for
2540 instance, the TQM823L systems are available without (standard)
2541 or with LCD support. You can select such additional "features"
2542 when chosing the configuration, i. e.
2545 - will configure for a plain TQM823L, i. e. no LCD support
2547 make TQM823L_LCD_config
2548 - will configure for a TQM823L with U-Boot console on LCD
2553 Finally, type "make all", and you should get some working U-Boot
2554 images ready for download to / installation on your system:
2556 - "u-boot.bin" is a raw binary image
2557 - "u-boot" is an image in ELF binary format
2558 - "u-boot.srec" is in Motorola S-Record format
2560 By default the build is performed locally and the objects are saved
2561 in the source directory. One of the two methods can be used to change
2562 this behavior and build U-Boot to some external directory:
2564 1. Add O= to the make command line invocations:
2566 make O=/tmp/build distclean
2567 make O=/tmp/build NAME_config
2568 make O=/tmp/build all
2570 2. Set environment variable BUILD_DIR to point to the desired location:
2572 export BUILD_DIR=/tmp/build
2577 Note that the command line "O=" setting overrides the BUILD_DIR environment
2581 Please be aware that the Makefiles assume you are using GNU make, so
2582 for instance on NetBSD you might need to use "gmake" instead of
2586 If the system board that you have is not listed, then you will need
2587 to port U-Boot to your hardware platform. To do this, follow these
2590 1. Add a new configuration option for your board to the toplevel
2591 "Makefile" and to the "MAKEALL" script, using the existing
2592 entries as examples. Note that here and at many other places
2593 boards and other names are listed in alphabetical sort order. Please
2595 2. Create a new directory to hold your board specific code. Add any
2596 files you need. In your board directory, you will need at least
2597 the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds".
2598 3. Create a new configuration file "include/configs/<board>.h" for
2600 3. If you're porting U-Boot to a new CPU, then also create a new
2601 directory to hold your CPU specific code. Add any files you need.
2602 4. Run "make <board>_config" with your new name.
2603 5. Type "make", and you should get a working "u-boot.srec" file
2604 to be installed on your target system.
2605 6. Debug and solve any problems that might arise.
2606 [Of course, this last step is much harder than it sounds.]
2609 Testing of U-Boot Modifications, Ports to New Hardware, etc.:
2610 ==============================================================
2612 If you have modified U-Boot sources (for instance added a new board
2613 or support for new devices, a new CPU, etc.) you are expected to
2614 provide feedback to the other developers. The feedback normally takes
2615 the form of a "patch", i. e. a context diff against a certain (latest
2616 official or latest in the git repository) version of U-Boot sources.
2618 But before you submit such a patch, please verify that your modifi-
2619 cation did not break existing code. At least make sure that *ALL* of
2620 the supported boards compile WITHOUT ANY compiler warnings. To do so,
2621 just run the "MAKEALL" script, which will configure and build U-Boot
2622 for ALL supported system. Be warned, this will take a while. You can
2623 select which (cross) compiler to use by passing a `CROSS_COMPILE'
2624 environment variable to the script, i. e. to use the ELDK cross tools
2627 CROSS_COMPILE=ppc_8xx- MAKEALL
2629 or to build on a native PowerPC system you can type
2631 CROSS_COMPILE=' ' MAKEALL
2633 When using the MAKEALL script, the default behaviour is to build
2634 U-Boot in the source directory. This location can be changed by
2635 setting the BUILD_DIR environment variable. Also, for each target
2636 built, the MAKEALL script saves two log files (<target>.ERR and
2637 <target>.MAKEALL) in the <source dir>/LOG directory. This default
2638 location can be changed by setting the MAKEALL_LOGDIR environment
2639 variable. For example:
2641 export BUILD_DIR=/tmp/build
2642 export MAKEALL_LOGDIR=/tmp/log
2643 CROSS_COMPILE=ppc_8xx- MAKEALL
2645 With the above settings build objects are saved in the /tmp/build,
2646 log files are saved in the /tmp/log and the source tree remains clean
2647 during the whole build process.
2650 See also "U-Boot Porting Guide" below.
2653 Monitor Commands - Overview:
2654 ============================
2656 go - start application at address 'addr'
2657 run - run commands in an environment variable
2658 bootm - boot application image from memory
2659 bootp - boot image via network using BootP/TFTP protocol
2660 tftpboot- boot image via network using TFTP protocol
2661 and env variables "ipaddr" and "serverip"
2662 (and eventually "gatewayip")
2663 rarpboot- boot image via network using RARP/TFTP protocol
2664 diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
2665 loads - load S-Record file over serial line
2666 loadb - load binary file over serial line (kermit mode)
2668 mm - memory modify (auto-incrementing)
2669 nm - memory modify (constant address)
2670 mw - memory write (fill)
2672 cmp - memory compare
2673 crc32 - checksum calculation
2674 imd - i2c memory display
2675 imm - i2c memory modify (auto-incrementing)
2676 inm - i2c memory modify (constant address)
2677 imw - i2c memory write (fill)
2678 icrc32 - i2c checksum calculation
2679 iprobe - probe to discover valid I2C chip addresses
2680 iloop - infinite loop on address range
2681 isdram - print SDRAM configuration information
2682 sspi - SPI utility commands
2683 base - print or set address offset
2684 printenv- print environment variables
2685 setenv - set environment variables
2686 saveenv - save environment variables to persistent storage
2687 protect - enable or disable FLASH write protection
2688 erase - erase FLASH memory
2689 flinfo - print FLASH memory information
2690 bdinfo - print Board Info structure
2691 iminfo - print header information for application image
2692 coninfo - print console devices and informations
2693 ide - IDE sub-system
2694 loop - infinite loop on address range
2695 loopw - infinite write loop on address range
2696 mtest - simple RAM test
2697 icache - enable or disable instruction cache
2698 dcache - enable or disable data cache
2699 reset - Perform RESET of the CPU
2700 echo - echo args to console
2701 version - print monitor version
2702 help - print online help
2703 ? - alias for 'help'
2706 Monitor Commands - Detailed Description:
2707 ========================================
2711 For now: just type "help <command>".
2714 Environment Variables:
2715 ======================
2717 U-Boot supports user configuration using Environment Variables which
2718 can be made persistent by saving to Flash memory.
2720 Environment Variables are set using "setenv", printed using
2721 "printenv", and saved to Flash using "saveenv". Using "setenv"
2722 without a value can be used to delete a variable from the
2723 environment. As long as you don't save the environment you are
2724 working with an in-memory copy. In case the Flash area containing the
2725 environment is erased by accident, a default environment is provided.
2727 Some configuration options can be set using Environment Variables:
2729 baudrate - see CONFIG_BAUDRATE
2731 bootdelay - see CONFIG_BOOTDELAY
2733 bootcmd - see CONFIG_BOOTCOMMAND
2735 bootargs - Boot arguments when booting an RTOS image
2737 bootfile - Name of the image to load with TFTP
2739 autoload - if set to "no" (any string beginning with 'n'),
2740 "bootp" will just load perform a lookup of the
2741 configuration from the BOOTP server, but not try to
2742 load any image using TFTP
2744 autoscript - if set to "yes" commands like "loadb", "loady",
2745 "bootp", "tftpb", "rarpboot" and "nfs" will attempt
2746 to automatically run script images (by internally
2747 calling "autoscript").
2749 autoscript_uname - if script image is in a format (FIT) this
2750 variable is used to get script subimage unit name.
2752 autostart - if set to "yes", an image loaded using the "bootp",
2753 "rarpboot", "tftpboot" or "diskboot" commands will
2754 be automatically started (by internally calling
2757 If set to "no", a standalone image passed to the
2758 "bootm" command will be copied to the load address
2759 (and eventually uncompressed), but NOT be started.
2760 This can be used to load and uncompress arbitrary
2763 i2cfast - (PPC405GP|PPC405EP only)
2764 if set to 'y' configures Linux I2C driver for fast
2765 mode (400kHZ). This environment variable is used in
2766 initialization code. So, for changes to be effective
2767 it must be saved and board must be reset.
2769 initrd_high - restrict positioning of initrd images:
2770 If this variable is not set, initrd images will be
2771 copied to the highest possible address in RAM; this
2772 is usually what you want since it allows for
2773 maximum initrd size. If for some reason you want to
2774 make sure that the initrd image is loaded below the
2775 CFG_BOOTMAPSZ limit, you can set this environment
2776 variable to a value of "no" or "off" or "0".
2777 Alternatively, you can set it to a maximum upper
2778 address to use (U-Boot will still check that it
2779 does not overwrite the U-Boot stack and data).
2781 For instance, when you have a system with 16 MB
2782 RAM, and want to reserve 4 MB from use by Linux,
2783 you can do this by adding "mem=12M" to the value of
2784 the "bootargs" variable. However, now you must make
2785 sure that the initrd image is placed in the first
2786 12 MB as well - this can be done with
2788 setenv initrd_high 00c00000
2790 If you set initrd_high to 0xFFFFFFFF, this is an
2791 indication to U-Boot that all addresses are legal
2792 for the Linux kernel, including addresses in flash
2793 memory. In this case U-Boot will NOT COPY the
2794 ramdisk at all. This may be useful to reduce the
2795 boot time on your system, but requires that this
2796 feature is supported by your Linux kernel.
2798 ipaddr - IP address; needed for tftpboot command
2800 loadaddr - Default load address for commands like "bootp",
2801 "rarpboot", "tftpboot", "loadb" or "diskboot"
2803 loads_echo - see CONFIG_LOADS_ECHO
2805 serverip - TFTP server IP address; needed for tftpboot command
2807 bootretry - see CONFIG_BOOT_RETRY_TIME
2809 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
2811 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
2813 ethprime - When CONFIG_NET_MULTI is enabled controls which
2814 interface is used first.
2816 ethact - When CONFIG_NET_MULTI is enabled controls which
2817 interface is currently active. For example you
2818 can do the following
2820 => setenv ethact FEC ETHERNET
2821 => ping 192.168.0.1 # traffic sent on FEC ETHERNET
2822 => setenv ethact SCC ETHERNET
2823 => ping 10.0.0.1 # traffic sent on SCC ETHERNET
2825 ethrotate - When set to "no" U-Boot does not go through all
2826 available network interfaces.
2827 It just stays at the currently selected interface.
2829 netretry - When set to "no" each network operation will
2830 either succeed or fail without retrying.
2831 When set to "once" the network operation will
2832 fail when all the available network interfaces
2833 are tried once without success.
2834 Useful on scripts which control the retry operation
2837 npe_ucode - see CONFIG_IXP4XX_NPE_EXT_UCOD
2838 if set load address for the npe microcode
2840 tftpsrcport - If this is set, the value is used for TFTP's
2843 tftpdstport - If this is set, the value is used for TFTP's UDP
2844 destination port instead of the Well Know Port 69.
2846 vlan - When set to a value < 4095 the traffic over
2847 ethernet is encapsulated/received over 802.1q
2850 The following environment variables may be used and automatically
2851 updated by the network boot commands ("bootp" and "rarpboot"),
2852 depending the information provided by your boot server:
2854 bootfile - see above
2855 dnsip - IP address of your Domain Name Server
2856 dnsip2 - IP address of your secondary Domain Name Server
2857 gatewayip - IP address of the Gateway (Router) to use
2858 hostname - Target hostname
2860 netmask - Subnet Mask
2861 rootpath - Pathname of the root filesystem on the NFS server
2862 serverip - see above
2865 There are two special Environment Variables:
2867 serial# - contains hardware identification information such
2868 as type string and/or serial number
2869 ethaddr - Ethernet address
2871 These variables can be set only once (usually during manufacturing of
2872 the board). U-Boot refuses to delete or overwrite these variables
2873 once they have been set once.
2876 Further special Environment Variables:
2878 ver - Contains the U-Boot version string as printed
2879 with the "version" command. This variable is
2880 readonly (see CONFIG_VERSION_VARIABLE).
2883 Please note that changes to some configuration parameters may take
2884 only effect after the next boot (yes, that's just like Windoze :-).
2887 Command Line Parsing:
2888 =====================
2890 There are two different command line parsers available with U-Boot:
2891 the old "simple" one, and the much more powerful "hush" shell:
2893 Old, simple command line parser:
2894 --------------------------------
2896 - supports environment variables (through setenv / saveenv commands)
2897 - several commands on one line, separated by ';'
2898 - variable substitution using "... ${name} ..." syntax
2899 - special characters ('$', ';') can be escaped by prefixing with '\',
2901 setenv bootcmd bootm \${address}
2902 - You can also escape text by enclosing in single apostrophes, for example:
2903 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
2908 - similar to Bourne shell, with control structures like
2909 if...then...else...fi, for...do...done; while...do...done,
2910 until...do...done, ...
2911 - supports environment ("global") variables (through setenv / saveenv
2912 commands) and local shell variables (through standard shell syntax
2913 "name=value"); only environment variables can be used with "run"
2919 (1) If a command line (or an environment variable executed by a "run"
2920 command) contains several commands separated by semicolon, and
2921 one of these commands fails, then the remaining commands will be
2924 (2) If you execute several variables with one call to run (i. e.
2925 calling run with a list af variables as arguments), any failing
2926 command will cause "run" to terminate, i. e. the remaining
2927 variables are not executed.
2929 Note for Redundant Ethernet Interfaces:
2930 =======================================
2932 Some boards come with redundant ethernet interfaces; U-Boot supports
2933 such configurations and is capable of automatic selection of a
2934 "working" interface when needed. MAC assignment works as follows:
2936 Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
2937 MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
2938 "eth1addr" (=>eth1), "eth2addr", ...
2940 If the network interface stores some valid MAC address (for instance
2941 in SROM), this is used as default address if there is NO correspon-
2942 ding setting in the environment; if the corresponding environment
2943 variable is set, this overrides the settings in the card; that means:
2945 o If the SROM has a valid MAC address, and there is no address in the
2946 environment, the SROM's address is used.
2948 o If there is no valid address in the SROM, and a definition in the
2949 environment exists, then the value from the environment variable is
2952 o If both the SROM and the environment contain a MAC address, and
2953 both addresses are the same, this MAC address is used.
2955 o If both the SROM and the environment contain a MAC address, and the
2956 addresses differ, the value from the environment is used and a
2959 o If neither SROM nor the environment contain a MAC address, an error
2966 U-Boot is capable of booting (and performing other auxiliary operations on)
2967 images in two formats:
2969 New uImage format (FIT)
2970 -----------------------
2972 Flexible and powerful format based on Flattened Image Tree -- FIT (similar
2973 to Flattened Device Tree). It allows the use of images with multiple
2974 components (several kernels, ramdisks, etc.), with contents protected by
2975 SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory.
2981 Old image format is based on binary files which can be basically anything,
2982 preceded by a special header; see the definitions in include/image.h for
2983 details; basically, the header defines the following image properties:
2985 * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
2986 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
2987 LynxOS, pSOS, QNX, RTEMS, ARTOS;
2988 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, ARTOS, LynxOS).
2989 * Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86,
2990 IA64, MIPS, NIOS, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
2991 Currently supported: ARM, AVR32, Intel x86, MIPS, NIOS, PowerPC).
2992 * Compression Type (uncompressed, gzip, bzip2)
2998 The header is marked by a special Magic Number, and both the header
2999 and the data portions of the image are secured against corruption by
3006 Although U-Boot should support any OS or standalone application
3007 easily, the main focus has always been on Linux during the design of
3010 U-Boot includes many features that so far have been part of some
3011 special "boot loader" code within the Linux kernel. Also, any
3012 "initrd" images to be used are no longer part of one big Linux image;
3013 instead, kernel and "initrd" are separate images. This implementation
3014 serves several purposes:
3016 - the same features can be used for other OS or standalone
3017 applications (for instance: using compressed images to reduce the
3018 Flash memory footprint)
3020 - it becomes much easier to port new Linux kernel versions because
3021 lots of low-level, hardware dependent stuff are done by U-Boot
3023 - the same Linux kernel image can now be used with different "initrd"
3024 images; of course this also means that different kernel images can
3025 be run with the same "initrd". This makes testing easier (you don't
3026 have to build a new "zImage.initrd" Linux image when you just
3027 change a file in your "initrd"). Also, a field-upgrade of the
3028 software is easier now.
3034 Porting Linux to U-Boot based systems:
3035 ---------------------------------------
3037 U-Boot cannot save you from doing all the necessary modifications to
3038 configure the Linux device drivers for use with your target hardware
3039 (no, we don't intend to provide a full virtual machine interface to
3042 But now you can ignore ALL boot loader code (in arch/ppc/mbxboot).
3044 Just make sure your machine specific header file (for instance
3045 include/asm-ppc/tqm8xx.h) includes the same definition of the Board
3046 Information structure as we define in include/u-boot.h, and make
3047 sure that your definition of IMAP_ADDR uses the same value as your
3048 U-Boot configuration in CFG_IMMR.
3051 Configuring the Linux kernel:
3052 -----------------------------
3054 No specific requirements for U-Boot. Make sure you have some root
3055 device (initial ramdisk, NFS) for your target system.
3058 Building a Linux Image:
3059 -----------------------
3061 With U-Boot, "normal" build targets like "zImage" or "bzImage" are
3062 not used. If you use recent kernel source, a new build target
3063 "uImage" will exist which automatically builds an image usable by
3064 U-Boot. Most older kernels also have support for a "pImage" target,
3065 which was introduced for our predecessor project PPCBoot and uses a
3066 100% compatible format.
3075 The "uImage" build target uses a special tool (in 'tools/mkimage') to
3076 encapsulate a compressed Linux kernel image with header information,
3077 CRC32 checksum etc. for use with U-Boot. This is what we are doing:
3079 * build a standard "vmlinux" kernel image (in ELF binary format):
3081 * convert the kernel into a raw binary image:
3083 ${CROSS_COMPILE}-objcopy -O binary \
3084 -R .note -R .comment \
3085 -S vmlinux linux.bin
3087 * compress the binary image:
3091 * package compressed binary image for U-Boot:
3093 mkimage -A ppc -O linux -T kernel -C gzip \
3094 -a 0 -e 0 -n "Linux Kernel Image" \
3095 -d linux.bin.gz uImage
3098 The "mkimage" tool can also be used to create ramdisk images for use
3099 with U-Boot, either separated from the Linux kernel image, or
3100 combined into one file. "mkimage" encapsulates the images with a 64
3101 byte header containing information about target architecture,
3102 operating system, image type, compression method, entry points, time
3103 stamp, CRC32 checksums, etc.
3105 "mkimage" can be called in two ways: to verify existing images and
3106 print the header information, or to build new images.
3108 In the first form (with "-l" option) mkimage lists the information
3109 contained in the header of an existing U-Boot image; this includes
3110 checksum verification:
3112 tools/mkimage -l image
3113 -l ==> list image header information
3115 The second form (with "-d" option) is used to build a U-Boot image
3116 from a "data file" which is used as image payload:
3118 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
3119 -n name -d data_file image
3120 -A ==> set architecture to 'arch'
3121 -O ==> set operating system to 'os'
3122 -T ==> set image type to 'type'
3123 -C ==> set compression type 'comp'
3124 -a ==> set load address to 'addr' (hex)
3125 -e ==> set entry point to 'ep' (hex)
3126 -n ==> set image name to 'name'
3127 -d ==> use image data from 'datafile'
3129 Right now, all Linux kernels for PowerPC systems use the same load
3130 address (0x00000000), but the entry point address depends on the
3133 - 2.2.x kernels have the entry point at 0x0000000C,
3134 - 2.3.x and later kernels have the entry point at 0x00000000.
3136 So a typical call to build a U-Boot image would read:
3138 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
3139 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
3140 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux.gz \
3141 > examples/uImage.TQM850L
3142 Image Name: 2.4.4 kernel for TQM850L
3143 Created: Wed Jul 19 02:34:59 2000
3144 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3145 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
3146 Load Address: 0x00000000
3147 Entry Point: 0x00000000
3149 To verify the contents of the image (or check for corruption):
3151 -> tools/mkimage -l examples/uImage.TQM850L
3152 Image Name: 2.4.4 kernel for TQM850L
3153 Created: Wed Jul 19 02:34:59 2000
3154 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3155 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
3156 Load Address: 0x00000000
3157 Entry Point: 0x00000000
3159 NOTE: for embedded systems where boot time is critical you can trade
3160 speed for memory and install an UNCOMPRESSED image instead: this
3161 needs more space in Flash, but boots much faster since it does not
3162 need to be uncompressed:
3164 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux.gz
3165 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
3166 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
3167 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux \
3168 > examples/uImage.TQM850L-uncompressed
3169 Image Name: 2.4.4 kernel for TQM850L
3170 Created: Wed Jul 19 02:34:59 2000
3171 Image Type: PowerPC Linux Kernel Image (uncompressed)
3172 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
3173 Load Address: 0x00000000
3174 Entry Point: 0x00000000
3177 Similar you can build U-Boot images from a 'ramdisk.image.gz' file
3178 when your kernel is intended to use an initial ramdisk:
3180 -> tools/mkimage -n 'Simple Ramdisk Image' \
3181 > -A ppc -O linux -T ramdisk -C gzip \
3182 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
3183 Image Name: Simple Ramdisk Image
3184 Created: Wed Jan 12 14:01:50 2000
3185 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
3186 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
3187 Load Address: 0x00000000
3188 Entry Point: 0x00000000
3191 Installing a Linux Image:
3192 -------------------------
3194 To downloading a U-Boot image over the serial (console) interface,
3195 you must convert the image to S-Record format:
3197 objcopy -I binary -O srec examples/image examples/image.srec
3199 The 'objcopy' does not understand the information in the U-Boot
3200 image header, so the resulting S-Record file will be relative to
3201 address 0x00000000. To load it to a given address, you need to
3202 specify the target address as 'offset' parameter with the 'loads'
3205 Example: install the image to address 0x40100000 (which on the
3206 TQM8xxL is in the first Flash bank):
3208 => erase 40100000 401FFFFF
3214 ## Ready for S-Record download ...
3215 ~>examples/image.srec
3216 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
3218 15989 15990 15991 15992
3219 [file transfer complete]
3221 ## Start Addr = 0x00000000
3224 You can check the success of the download using the 'iminfo' command;
3225 this includes a checksum verification so you can be sure no data
3226 corruption happened:
3230 ## Checking Image at 40100000 ...
3231 Image Name: 2.2.13 for initrd on TQM850L
3232 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3233 Data Size: 335725 Bytes = 327 kB = 0 MB
3234 Load Address: 00000000
3235 Entry Point: 0000000c
3236 Verifying Checksum ... OK
3242 The "bootm" command is used to boot an application that is stored in
3243 memory (RAM or Flash). In case of a Linux kernel image, the contents
3244 of the "bootargs" environment variable is passed to the kernel as
3245 parameters. You can check and modify this variable using the
3246 "printenv" and "setenv" commands:
3249 => printenv bootargs
3250 bootargs=root=/dev/ram
3252 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
3254 => printenv bootargs
3255 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
3258 ## Booting Linux kernel at 40020000 ...
3259 Image Name: 2.2.13 for NFS on TQM850L
3260 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3261 Data Size: 381681 Bytes = 372 kB = 0 MB
3262 Load Address: 00000000
3263 Entry Point: 0000000c
3264 Verifying Checksum ... OK
3265 Uncompressing Kernel Image ... OK
3266 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
3267 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
3268 time_init: decrementer frequency = 187500000/60
3269 Calibrating delay loop... 49.77 BogoMIPS
3270 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
3273 If you want to boot a Linux kernel with initial ram disk, you pass
3274 the memory addresses of both the kernel and the initrd image (PPBCOOT
3275 format!) to the "bootm" command:
3277 => imi 40100000 40200000
3279 ## Checking Image at 40100000 ...
3280 Image Name: 2.2.13 for initrd on TQM850L
3281 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3282 Data Size: 335725 Bytes = 327 kB = 0 MB
3283 Load Address: 00000000
3284 Entry Point: 0000000c
3285 Verifying Checksum ... OK
3287 ## Checking Image at 40200000 ...
3288 Image Name: Simple Ramdisk Image
3289 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
3290 Data Size: 566530 Bytes = 553 kB = 0 MB
3291 Load Address: 00000000
3292 Entry Point: 00000000
3293 Verifying Checksum ... OK
3295 => bootm 40100000 40200000
3296 ## Booting Linux kernel at 40100000 ...
3297 Image Name: 2.2.13 for initrd on TQM850L
3298 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3299 Data Size: 335725 Bytes = 327 kB = 0 MB
3300 Load Address: 00000000
3301 Entry Point: 0000000c
3302 Verifying Checksum ... OK
3303 Uncompressing Kernel Image ... OK
3304 ## Loading RAMDisk Image at 40200000 ...
3305 Image Name: Simple Ramdisk Image
3306 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
3307 Data Size: 566530 Bytes = 553 kB = 0 MB
3308 Load Address: 00000000
3309 Entry Point: 00000000
3310 Verifying Checksum ... OK
3311 Loading Ramdisk ... OK
3312 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
3313 Boot arguments: root=/dev/ram
3314 time_init: decrementer frequency = 187500000/60
3315 Calibrating delay loop... 49.77 BogoMIPS
3317 RAMDISK: Compressed image found at block 0
3318 VFS: Mounted root (ext2 filesystem).
3322 Boot Linux and pass a flat device tree:
3325 First, U-Boot must be compiled with the appropriate defines. See the section
3326 titled "Linux Kernel Interface" above for a more in depth explanation. The
3327 following is an example of how to start a kernel and pass an updated
3333 oft=oftrees/mpc8540ads.dtb
3334 => tftp $oftaddr $oft
3335 Speed: 1000, full duplex
3337 TFTP from server 192.168.1.1; our IP address is 192.168.1.101
3338 Filename 'oftrees/mpc8540ads.dtb'.
3339 Load address: 0x300000
3342 Bytes transferred = 4106 (100a hex)
3343 => tftp $loadaddr $bootfile
3344 Speed: 1000, full duplex
3346 TFTP from server 192.168.1.1; our IP address is 192.168.1.2
3348 Load address: 0x200000
3349 Loading:############
3351 Bytes transferred = 1029407 (fb51f hex)
3356 => bootm $loadaddr - $oftaddr
3357 ## Booting image at 00200000 ...
3358 Image Name: Linux-2.6.17-dirty
3359 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3360 Data Size: 1029343 Bytes = 1005.2 kB
3361 Load Address: 00000000
3362 Entry Point: 00000000
3363 Verifying Checksum ... OK
3364 Uncompressing Kernel Image ... OK
3365 Booting using flat device tree at 0x300000
3366 Using MPC85xx ADS machine description
3367 Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb
3371 More About U-Boot Image Types:
3372 ------------------------------
3374 U-Boot supports the following image types:
3376 "Standalone Programs" are directly runnable in the environment
3377 provided by U-Boot; it is expected that (if they behave
3378 well) you can continue to work in U-Boot after return from
3379 the Standalone Program.
3380 "OS Kernel Images" are usually images of some Embedded OS which
3381 will take over control completely. Usually these programs
3382 will install their own set of exception handlers, device
3383 drivers, set up the MMU, etc. - this means, that you cannot
3384 expect to re-enter U-Boot except by resetting the CPU.
3385 "RAMDisk Images" are more or less just data blocks, and their
3386 parameters (address, size) are passed to an OS kernel that is
3388 "Multi-File Images" contain several images, typically an OS
3389 (Linux) kernel image and one or more data images like
3390 RAMDisks. This construct is useful for instance when you want
3391 to boot over the network using BOOTP etc., where the boot
3392 server provides just a single image file, but you want to get
3393 for instance an OS kernel and a RAMDisk image.
3395 "Multi-File Images" start with a list of image sizes, each
3396 image size (in bytes) specified by an "uint32_t" in network
3397 byte order. This list is terminated by an "(uint32_t)0".
3398 Immediately after the terminating 0 follow the images, one by
3399 one, all aligned on "uint32_t" boundaries (size rounded up to
3400 a multiple of 4 bytes).
3402 "Firmware Images" are binary images containing firmware (like
3403 U-Boot or FPGA images) which usually will be programmed to
3406 "Script files" are command sequences that will be executed by
3407 U-Boot's command interpreter; this feature is especially
3408 useful when you configure U-Boot to use a real shell (hush)
3409 as command interpreter.
3415 One of the features of U-Boot is that you can dynamically load and
3416 run "standalone" applications, which can use some resources of
3417 U-Boot like console I/O functions or interrupt services.
3419 Two simple examples are included with the sources:
3424 'examples/hello_world.c' contains a small "Hello World" Demo
3425 application; it is automatically compiled when you build U-Boot.
3426 It's configured to run at address 0x00040004, so you can play with it
3430 ## Ready for S-Record download ...
3431 ~>examples/hello_world.srec
3432 1 2 3 4 5 6 7 8 9 10 11 ...
3433 [file transfer complete]
3435 ## Start Addr = 0x00040004
3437 => go 40004 Hello World! This is a test.
3438 ## Starting application at 0x00040004 ...
3449 Hit any key to exit ...
3451 ## Application terminated, rc = 0x0
3453 Another example, which demonstrates how to register a CPM interrupt
3454 handler with the U-Boot code, can be found in 'examples/timer.c'.
3455 Here, a CPM timer is set up to generate an interrupt every second.
3456 The interrupt service routine is trivial, just printing a '.'
3457 character, but this is just a demo program. The application can be
3458 controlled by the following keys:
3460 ? - print current values og the CPM Timer registers
3461 b - enable interrupts and start timer
3462 e - stop timer and disable interrupts
3463 q - quit application
3466 ## Ready for S-Record download ...
3467 ~>examples/timer.srec
3468 1 2 3 4 5 6 7 8 9 10 11 ...
3469 [file transfer complete]
3471 ## Start Addr = 0x00040004
3474 ## Starting application at 0x00040004 ...
3477 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
3480 [q, b, e, ?] Set interval 1000000 us
3483 [q, b, e, ?] ........
3484 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
3487 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
3490 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
3493 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
3495 [q, b, e, ?] ...Stopping timer
3497 [q, b, e, ?] ## Application terminated, rc = 0x0
3503 Over time, many people have reported problems when trying to use the
3504 "minicom" terminal emulation program for serial download. I (wd)
3505 consider minicom to be broken, and recommend not to use it. Under
3506 Unix, I recommend to use C-Kermit for general purpose use (and
3507 especially for kermit binary protocol download ("loadb" command), and
3508 use "cu" for S-Record download ("loads" command).
3510 Nevertheless, if you absolutely want to use it try adding this
3511 configuration to your "File transfer protocols" section:
3513 Name Program Name U/D FullScr IO-Red. Multi
3514 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
3515 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
3521 Starting at version 0.9.2, U-Boot supports NetBSD both as host
3522 (build U-Boot) and target system (boots NetBSD/mpc8xx).
3524 Building requires a cross environment; it is known to work on
3525 NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
3526 need gmake since the Makefiles are not compatible with BSD make).
3527 Note that the cross-powerpc package does not install include files;
3528 attempting to build U-Boot will fail because <machine/ansi.h> is
3529 missing. This file has to be installed and patched manually:
3531 # cd /usr/pkg/cross/powerpc-netbsd/include
3533 # ln -s powerpc machine
3534 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
3535 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
3537 Native builds *don't* work due to incompatibilities between native
3538 and U-Boot include files.
3540 Booting assumes that (the first part of) the image booted is a
3541 stage-2 loader which in turn loads and then invokes the kernel
3542 proper. Loader sources will eventually appear in the NetBSD source
3543 tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
3544 meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz
3547 Implementation Internals:
3548 =========================
3550 The following is not intended to be a complete description of every
3551 implementation detail. However, it should help to understand the
3552 inner workings of U-Boot and make it easier to port it to custom
3556 Initial Stack, Global Data:
3557 ---------------------------
3559 The implementation of U-Boot is complicated by the fact that U-Boot
3560 starts running out of ROM (flash memory), usually without access to
3561 system RAM (because the memory controller is not initialized yet).
3562 This means that we don't have writable Data or BSS segments, and BSS
3563 is not initialized as zero. To be able to get a C environment working
3564 at all, we have to allocate at least a minimal stack. Implementation
3565 options for this are defined and restricted by the CPU used: Some CPU
3566 models provide on-chip memory (like the IMMR area on MPC8xx and
3567 MPC826x processors), on others (parts of) the data cache can be
3568 locked as (mis-) used as memory, etc.
3570 Chris Hallinan posted a good summary of these issues to the
3571 u-boot-users mailing list:
3573 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
3574 From: "Chris Hallinan" <clh@net1plus.com>
3575 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
3578 Correct me if I'm wrong, folks, but the way I understand it
3579 is this: Using DCACHE as initial RAM for Stack, etc, does not
3580 require any physical RAM backing up the cache. The cleverness
3581 is that the cache is being used as a temporary supply of
3582 necessary storage before the SDRAM controller is setup. It's
3583 beyond the scope of this list to expain the details, but you
3584 can see how this works by studying the cache architecture and
3585 operation in the architecture and processor-specific manuals.
3587 OCM is On Chip Memory, which I believe the 405GP has 4K. It
3588 is another option for the system designer to use as an
3589 initial stack/ram area prior to SDRAM being available. Either
3590 option should work for you. Using CS 4 should be fine if your
3591 board designers haven't used it for something that would
3592 cause you grief during the initial boot! It is frequently not
3595 CFG_INIT_RAM_ADDR should be somewhere that won't interfere
3596 with your processor/board/system design. The default value
3597 you will find in any recent u-boot distribution in
3598 walnut.h should work for you. I'd set it to a value larger
3599 than your SDRAM module. If you have a 64MB SDRAM module, set
3600 it above 400_0000. Just make sure your board has no resources
3601 that are supposed to respond to that address! That code in
3602 start.S has been around a while and should work as is when
3603 you get the config right.
3608 It is essential to remember this, since it has some impact on the C
3609 code for the initialization procedures:
3611 * Initialized global data (data segment) is read-only. Do not attempt
3614 * Do not use any unitialized global data (or implicitely initialized
3615 as zero data - BSS segment) at all - this is undefined, initiali-
3616 zation is performed later (when relocating to RAM).
3618 * Stack space is very limited. Avoid big data buffers or things like
3621 Having only the stack as writable memory limits means we cannot use
3622 normal global data to share information beween the code. But it
3623 turned out that the implementation of U-Boot can be greatly
3624 simplified by making a global data structure (gd_t) available to all
3625 functions. We could pass a pointer to this data as argument to _all_
3626 functions, but this would bloat the code. Instead we use a feature of
3627 the GCC compiler (Global Register Variables) to share the data: we
3628 place a pointer (gd) to the global data into a register which we
3629 reserve for this purpose.
3631 When choosing a register for such a purpose we are restricted by the
3632 relevant (E)ABI specifications for the current architecture, and by
3633 GCC's implementation.
3635 For PowerPC, the following registers have specific use:
3637 R2: reserved for system use
3638 R3-R4: parameter passing and return values
3639 R5-R10: parameter passing
3640 R13: small data area pointer
3644 (U-Boot also uses R14 as internal GOT pointer.)
3646 ==> U-Boot will use R2 to hold a pointer to the global data
3648 Note: on PPC, we could use a static initializer (since the
3649 address of the global data structure is known at compile time),
3650 but it turned out that reserving a register results in somewhat
3651 smaller code - although the code savings are not that big (on
3652 average for all boards 752 bytes for the whole U-Boot image,
3653 624 text + 127 data).
3655 On Blackfin, the normal C ABI (except for P5) is followed as documented here:
3656 http://docs.blackfin.uclinux.org/doku.php?id=application_binary_interface
3658 ==> U-Boot will use P5 to hold a pointer to the global data
3660 On ARM, the following registers are used:
3662 R0: function argument word/integer result
3663 R1-R3: function argument word
3665 R10: stack limit (used only if stack checking if enabled)
3666 R11: argument (frame) pointer
3667 R12: temporary workspace
3670 R15: program counter
3672 ==> U-Boot will use R8 to hold a pointer to the global data
3674 NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope,
3675 or current versions of GCC may "optimize" the code too much.
3680 U-Boot runs in system state and uses physical addresses, i.e. the
3681 MMU is not used either for address mapping nor for memory protection.
3683 The available memory is mapped to fixed addresses using the memory
3684 controller. In this process, a contiguous block is formed for each
3685 memory type (Flash, SDRAM, SRAM), even when it consists of several
3686 physical memory banks.
3688 U-Boot is installed in the first 128 kB of the first Flash bank (on
3689 TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
3690 booting and sizing and initializing DRAM, the code relocates itself
3691 to the upper end of DRAM. Immediately below the U-Boot code some
3692 memory is reserved for use by malloc() [see CFG_MALLOC_LEN
3693 configuration setting]. Below that, a structure with global Board
3694 Info data is placed, followed by the stack (growing downward).
3696 Additionally, some exception handler code is copied to the low 8 kB
3697 of DRAM (0x00000000 ... 0x00001FFF).
3699 So a typical memory configuration with 16 MB of DRAM could look like
3702 0x0000 0000 Exception Vector code
3705 0x0000 2000 Free for Application Use
3711 0x00FB FF20 Monitor Stack (Growing downward)
3712 0x00FB FFAC Board Info Data and permanent copy of global data
3713 0x00FC 0000 Malloc Arena
3716 0x00FE 0000 RAM Copy of Monitor Code
3717 ... eventually: LCD or video framebuffer
3718 ... eventually: pRAM (Protected RAM - unchanged by reset)
3719 0x00FF FFFF [End of RAM]
3722 System Initialization:
3723 ----------------------
3725 In the reset configuration, U-Boot starts at the reset entry point
3726 (on most PowerPC systens at address 0x00000100). Because of the reset
3727 configuration for CS0# this is a mirror of the onboard Flash memory.
3728 To be able to re-map memory U-Boot then jumps to its link address.
3729 To be able to implement the initialization code in C, a (small!)
3730 initial stack is set up in the internal Dual Ported RAM (in case CPUs
3731 which provide such a feature like MPC8xx or MPC8260), or in a locked
3732 part of the data cache. After that, U-Boot initializes the CPU core,
3733 the caches and the SIU.
3735 Next, all (potentially) available memory banks are mapped using a
3736 preliminary mapping. For example, we put them on 512 MB boundaries
3737 (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
3738 on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
3739 programmed for SDRAM access. Using the temporary configuration, a
3740 simple memory test is run that determines the size of the SDRAM
3743 When there is more than one SDRAM bank, and the banks are of
3744 different size, the largest is mapped first. For equal size, the first
3745 bank (CS2#) is mapped first. The first mapping is always for address
3746 0x00000000, with any additional banks following immediately to create
3747 contiguous memory starting from 0.
3749 Then, the monitor installs itself at the upper end of the SDRAM area
3750 and allocates memory for use by malloc() and for the global Board
3751 Info data; also, the exception vector code is copied to the low RAM
3752 pages, and the final stack is set up.
3754 Only after this relocation will you have a "normal" C environment;
3755 until that you are restricted in several ways, mostly because you are
3756 running from ROM, and because the code will have to be relocated to a
3760 U-Boot Porting Guide:
3761 ----------------------
3763 [Based on messages by Jerry Van Baren in the U-Boot-Users mailing
3767 int main (int argc, char *argv[])
3769 sighandler_t no_more_time;
3771 signal (SIGALRM, no_more_time);
3772 alarm (PROJECT_DEADLINE - toSec (3 * WEEK));
3774 if (available_money > available_manpower) {
3775 pay consultant to port U-Boot;
3779 Download latest U-Boot source;
3781 Subscribe to u-boot-users mailing list;
3784 email ("Hi, I am new to U-Boot, how do I get started?");
3788 Read the README file in the top level directory;
3789 Read http://www.denx.de/twiki/bin/view/DULG/Manual ;
3790 Read the source, Luke;
3793 if (available_money > toLocalCurrency ($2500)) {
3796 Add a lot of aggravation and time;
3799 Create your own board support subdirectory;
3801 Create your own board config file;
3805 Add / modify source code;
3809 email ("Hi, I am having problems...");
3811 Send patch file to Wolfgang;
3816 void no_more_time (int sig)
3825 All contributions to U-Boot should conform to the Linux kernel
3826 coding style; see the file "Documentation/CodingStyle" and the script
3827 "scripts/Lindent" in your Linux kernel source directory. In sources
3828 originating from U-Boot a style corresponding to "Lindent -pcs" (adding
3829 spaces before parameters to function calls) is actually used.
3831 Source files originating from a different project (for example the
3832 MTD subsystem) are generally exempt from these guidelines and are not
3833 reformated to ease subsequent migration to newer versions of those
3836 Please note that U-Boot is implemented in C (and to some small parts in
3837 Assembler); no C++ is used, so please do not use C++ style comments (//)
3840 Please also stick to the following formatting rules:
3841 - remove any trailing white space
3842 - use TAB characters for indentation, not spaces
3843 - make sure NOT to use DOS '\r\n' line feeds
3844 - do not add more than 2 empty lines to source files
3845 - do not add trailing empty lines to source files
3847 Submissions which do not conform to the standards may be returned
3848 with a request to reformat the changes.
3854 Since the number of patches for U-Boot is growing, we need to
3855 establish some rules. Submissions which do not conform to these rules
3856 may be rejected, even when they contain important and valuable stuff.
3858 Patches shall be sent to the u-boot-users mailing list.
3860 Please see http://www.denx.de/wiki/UBoot/Patches for details.
3862 When you send a patch, please include the following information with
3865 * For bug fixes: a description of the bug and how your patch fixes
3866 this bug. Please try to include a way of demonstrating that the
3867 patch actually fixes something.
3869 * For new features: a description of the feature and your
3872 * A CHANGELOG entry as plaintext (separate from the patch)
3874 * For major contributions, your entry to the CREDITS file
3876 * When you add support for a new board, don't forget to add this
3877 board to the MAKEALL script, too.
3879 * If your patch adds new configuration options, don't forget to
3880 document these in the README file.
3882 * The patch itself. If you are using git (which is *strongly*
3883 recommended) you can easily generate the patch using the
3884 "git-format-patch". If you then use "git-send-email" to send it to
3885 the U-Boot mailing list, you will avoid most of the common problems
3886 with some other mail clients.
3888 If you cannot use git, use "diff -purN OLD NEW". If your version of
3889 diff does not support these options, then get the latest version of
3892 The current directory when running this command shall be the parent
3893 directory of the U-Boot source tree (i. e. please make sure that
3894 your patch includes sufficient directory information for the
3897 We prefer patches as plain text. MIME attachments are discouraged,
3898 and compressed attachments must not be used.
3900 * If one logical set of modifications affects or creates several
3901 files, all these changes shall be submitted in a SINGLE patch file.
3903 * Changesets that contain different, unrelated modifications shall be
3904 submitted as SEPARATE patches, one patch per changeset.
3909 * Before sending the patch, run the MAKEALL script on your patched
3910 source tree and make sure that no errors or warnings are reported
3911 for any of the boards.
3913 * Keep your modifications to the necessary minimum: A patch
3914 containing several unrelated changes or arbitrary reformats will be
3915 returned with a request to re-formatting / split it.
3917 * If you modify existing code, make sure that your new code does not
3918 add to the memory footprint of the code ;-) Small is beautiful!
3919 When adding new features, these should compile conditionally only
3920 (using #ifdef), and the resulting code with the new feature
3921 disabled must not need more memory than the old code without your
3924 * Remember that there is a size limit of 40 kB per message on the
3925 u-boot-users mailing list. Bigger patches will be moderated. If
3926 they are reasonable and not bigger than 100 kB, they will be
3927 acknowledged. Even bigger patches should be avoided.
projects / platform / kernel / u-boot.git / blob