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 - mcf52x2 Files specific to Freescale ColdFire MCF52x2 CPUs
157 - mcf5227x Files specific to Freescale ColdFire MCF5227x CPUs
158 - mcf532x Files specific to Freescale ColdFire MCF5329 CPUs
159 - mcf5445x Files specific to Freescale ColdFire MCF5445x CPUs
160 - mcf547x_8x Files specific to Freescale ColdFire MCF547x_8x CPUs
161 - mips Files specific to MIPS CPUs
162 - mpc5xx Files specific to Freescale MPC5xx CPUs
163 - mpc5xxx Files specific to Freescale MPC5xxx CPUs
164 - mpc8xx Files specific to Freescale MPC8xx CPUs
165 - mpc8220 Files specific to Freescale MPC8220 CPUs
166 - mpc824x Files specific to Freescale MPC824x CPUs
167 - mpc8260 Files specific to Freescale MPC8260 CPUs
168 - mpc85xx Files specific to Freescale MPC85xx CPUs
169 - nios Files specific to Altera NIOS CPUs
170 - nios2 Files specific to Altera Nios-II CPUs
171 - ppc4xx Files specific to AMCC PowerPC 4xx CPUs
172 - pxa Files specific to Intel XScale PXA CPUs
173 - s3c44b0 Files specific to Samsung S3C44B0 CPUs
174 - sa1100 Files specific to Intel StrongARM SA1100 CPUs
175 - disk Code for disk drive partition handling
176 - doc Documentation (don't expect too much)
177 - drivers Commonly used device drivers
178 - dtt Digital Thermometer and Thermostat drivers
179 - examples Example code for standalone applications, etc.
180 - include Header Files
181 - lib_arm Files generic to ARM architecture
182 - lib_avr32 Files generic to AVR32 architecture
183 - lib_generic Files generic to all architectures
184 - lib_i386 Files generic to i386 architecture
185 - lib_m68k Files generic to m68k architecture
186 - lib_mips Files generic to MIPS architecture
187 - lib_nios Files generic to NIOS architecture
188 - lib_ppc Files generic to PowerPC architecture
189 - lib_sparc Files generic to SPARC architecture
190 - libfdt Library files to support flattened device trees
191 - net Networking code
192 - post Power On Self Test
193 - rtc Real Time Clock drivers
194 - tools Tools to build S-Record or U-Boot images, etc.
196 Software Configuration:
197 =======================
199 Configuration is usually done using C preprocessor defines; the
200 rationale behind that is to avoid dead code whenever possible.
202 There are two classes of configuration variables:
204 * Configuration _OPTIONS_:
205 These are selectable by the user and have names beginning with
208 * Configuration _SETTINGS_:
209 These depend on the hardware etc. and should not be meddled with if
210 you don't know what you're doing; they have names beginning with
213 Later we will add a configuration tool - probably similar to or even
214 identical to what's used for the Linux kernel. Right now, we have to
215 do the configuration by hand, which means creating some symbolic
216 links and editing some configuration files. We use the TQM8xxL boards
220 Selection of Processor Architecture and Board Type:
221 ---------------------------------------------------
223 For all supported boards there are ready-to-use default
224 configurations available; just type "make <board_name>_config".
226 Example: For a TQM823L module type:
231 For the Cogent platform, you need to specify the cpu type as well;
232 e.g. "make cogent_mpc8xx_config". And also configure the cogent
233 directory according to the instructions in cogent/README.
236 Configuration Options:
237 ----------------------
239 Configuration depends on the combination of board and CPU type; all
240 such information is kept in a configuration file
241 "include/configs/<board_name>.h".
243 Example: For a TQM823L module, all configuration settings are in
244 "include/configs/TQM823L.h".
247 Many of the options are named exactly as the corresponding Linux
248 kernel configuration options. The intention is to make it easier to
249 build a config tool - later.
252 The following options need to be configured:
254 - CPU Type: Define exactly one, e.g. CONFIG_MPC85XX.
256 - Board Type: Define exactly one, e.g. CONFIG_MPC8540ADS.
258 - CPU Daughterboard Type: (if CONFIG_ATSTK1000 is defined)
259 Define exactly one, e.g. CONFIG_ATSTK1002
261 - CPU Module Type: (if CONFIG_COGENT is defined)
262 Define exactly one of
264 --- FIXME --- not tested yet:
265 CONFIG_CMA286_60, CONFIG_CMA286_21, CONFIG_CMA286_60P,
266 CONFIG_CMA287_23, CONFIG_CMA287_50
268 - Motherboard Type: (if CONFIG_COGENT is defined)
269 Define exactly one of
270 CONFIG_CMA101, CONFIG_CMA102
272 - Motherboard I/O Modules: (if CONFIG_COGENT is defined)
273 Define one or more of
276 - Motherboard Options: (if CONFIG_CMA101 or CONFIG_CMA102 are defined)
277 Define one or more of
278 CONFIG_LCD_HEARTBEAT - update a character position on
279 the lcd display every second with
282 - Board flavour: (if CONFIG_MPC8260ADS is defined)
285 CFG_8260ADS - original MPC8260ADS
286 CFG_8266ADS - MPC8266ADS
287 CFG_PQ2FADS - PQ2FADS-ZU or PQ2FADS-VR
288 CFG_8272ADS - MPC8272ADS
290 - MPC824X Family Member (if CONFIG_MPC824X is defined)
291 Define exactly one of
292 CONFIG_MPC8240, CONFIG_MPC8245
294 - 8xx CPU Options: (if using an MPC8xx cpu)
295 CONFIG_8xx_GCLK_FREQ - deprecated: CPU clock if
296 get_gclk_freq() cannot work
297 e.g. if there is no 32KHz
298 reference PIT/RTC clock
299 CONFIG_8xx_OSCLK - PLL input clock (either EXTCLK
302 - 859/866/885 CPU options: (if using a MPC859 or MPC866 or MPC885 CPU):
305 CONFIG_8xx_CPUCLK_DEFAULT
306 See doc/README.MPC866
310 Define this to measure the actual CPU clock instead
311 of relying on the correctness of the configured
312 values. Mostly useful for board bringup to make sure
313 the PLL is locked at the intended frequency. Note
314 that this requires a (stable) reference clock (32 kHz
315 RTC clock or CFG_8XX_XIN)
317 - Intel Monahans options:
318 CFG_MONAHANS_RUN_MODE_OSC_RATIO
320 Defines the Monahans run mode to oscillator
321 ratio. Valid values are 8, 16, 24, 31. The core
322 frequency is this value multiplied by 13 MHz.
324 CFG_MONAHANS_TURBO_RUN_MODE_RATIO
326 Defines the Monahans turbo mode to oscillator
327 ratio. Valid values are 1 (default if undefined) and
328 2. The core frequency as calculated above is multiplied
331 - Linux Kernel Interface:
334 U-Boot stores all clock information in Hz
335 internally. For binary compatibility with older Linux
336 kernels (which expect the clocks passed in the
337 bd_info data to be in MHz) the environment variable
338 "clocks_in_mhz" can be defined so that U-Boot
339 converts clock data to MHZ before passing it to the
341 When CONFIG_CLOCKS_IN_MHZ is defined, a definition of
342 "clocks_in_mhz=1" is automatically included in the
345 CONFIG_MEMSIZE_IN_BYTES [relevant for MIPS only]
347 When transfering memsize parameter to linux, some versions
348 expect it to be in bytes, others in MB.
349 Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes.
351 CONFIG_OF_LIBFDT / CONFIG_OF_FLAT_TREE
353 New kernel versions are expecting firmware settings to be
354 passed using flattened device trees (based on open firmware
358 * New libfdt-based support
359 * Adds the "fdt" command
360 * The bootm command automatically updates the fdt
363 * Deprecated, see CONFIG_OF_LIBFDT
364 * Original ft_build.c-based support
365 * Automatically modifies the dft as part of the bootm command
366 * The environment variable "disable_of", when set,
367 disables this functionality.
369 OF_CPU - The proper name of the cpus node.
370 OF_SOC - The proper name of the soc node.
371 OF_TBCLK - The timebase frequency.
372 OF_STDOUT_PATH - The path to the console device
374 boards with QUICC Engines require OF_QE to set UCC mac addresses
376 CONFIG_OF_BOARD_SETUP
378 Board code has addition modification that it wants to make
379 to the flat device tree before handing it off to the kernel
383 This define fills in the correct boot cpu in the boot
384 param header, the default value is zero if undefined.
389 Define this if you want support for Amba PrimeCell PL010 UARTs.
393 Define this if you want support for Amba PrimeCell PL011 UARTs.
397 If you have Amba PrimeCell PL011 UARTs, set this variable to
398 the clock speed of the UARTs.
402 If you have Amba PrimeCell PL010 or PL011 UARTs on your board,
403 define this to a list of base addresses for each (supported)
404 port. See e.g. include/configs/versatile.h
408 Depending on board, define exactly one serial port
409 (like CONFIG_8xx_CONS_SMC1, CONFIG_8xx_CONS_SMC2,
410 CONFIG_8xx_CONS_SCC1, ...), or switch off the serial
411 console by defining CONFIG_8xx_CONS_NONE
413 Note: if CONFIG_8xx_CONS_NONE is defined, the serial
414 port routines must be defined elsewhere
415 (i.e. serial_init(), serial_getc(), ...)
418 Enables console device for a color framebuffer. Needs following
419 defines (cf. smiLynxEM, i8042, board/eltec/bab7xx)
420 VIDEO_FB_LITTLE_ENDIAN graphic memory organisation
422 VIDEO_HW_RECTFILL graphic chip supports
425 VIDEO_HW_BITBLT graphic chip supports
426 bit-blit (cf. smiLynxEM)
427 VIDEO_VISIBLE_COLS visible pixel columns
429 VIDEO_VISIBLE_ROWS visible pixel rows
430 VIDEO_PIXEL_SIZE bytes per pixel
431 VIDEO_DATA_FORMAT graphic data format
432 (0-5, cf. cfb_console.c)
433 VIDEO_FB_ADRS framebuffer address
434 VIDEO_KBD_INIT_FCT keyboard int fct
435 (i.e. i8042_kbd_init())
436 VIDEO_TSTC_FCT test char fct
438 VIDEO_GETC_FCT get char fct
440 CONFIG_CONSOLE_CURSOR cursor drawing on/off
441 (requires blink timer
443 CFG_CONSOLE_BLINK_COUNT blink interval (cf. i8042.c)
444 CONFIG_CONSOLE_TIME display time/date info in
446 (requires CONFIG_CMD_DATE)
447 CONFIG_VIDEO_LOGO display Linux logo in
449 CONFIG_VIDEO_BMP_LOGO use bmp_logo.h instead of
450 linux_logo.h for logo.
451 Requires CONFIG_VIDEO_LOGO
452 CONFIG_CONSOLE_EXTRA_INFO
453 addional board info beside
456 When CONFIG_CFB_CONSOLE is defined, video console is
457 default i/o. Serial console can be forced with
458 environment 'console=serial'.
460 When CONFIG_SILENT_CONSOLE is defined, all console
461 messages (by U-Boot and Linux!) can be silenced with
462 the "silent" environment variable. See
463 doc/README.silent for more information.
466 CONFIG_BAUDRATE - in bps
467 Select one of the baudrates listed in
468 CFG_BAUDRATE_TABLE, see below.
469 CFG_BRGCLK_PRESCALE, baudrate prescale
471 - Interrupt driven serial port input:
472 CONFIG_SERIAL_SOFTWARE_FIFO
475 Use an interrupt handler for receiving data on the
476 serial port. It also enables using hardware handshake
477 (RTS/CTS) and UART's built-in FIFO. Set the number of
478 bytes the interrupt driven input buffer should have.
480 Leave undefined to disable this feature, including
481 disable the buffer and hardware handshake.
483 - Console UART Number:
487 If defined internal UART1 (and not UART0) is used
488 as default U-Boot console.
490 - Boot Delay: CONFIG_BOOTDELAY - in seconds
491 Delay before automatically booting the default image;
492 set to -1 to disable autoboot.
494 See doc/README.autoboot for these options that
495 work with CONFIG_BOOTDELAY. None are required.
496 CONFIG_BOOT_RETRY_TIME
497 CONFIG_BOOT_RETRY_MIN
498 CONFIG_AUTOBOOT_KEYED
499 CONFIG_AUTOBOOT_PROMPT
500 CONFIG_AUTOBOOT_DELAY_STR
501 CONFIG_AUTOBOOT_STOP_STR
502 CONFIG_AUTOBOOT_DELAY_STR2
503 CONFIG_AUTOBOOT_STOP_STR2
504 CONFIG_ZERO_BOOTDELAY_CHECK
505 CONFIG_RESET_TO_RETRY
509 Only needed when CONFIG_BOOTDELAY is enabled;
510 define a command string that is automatically executed
511 when no character is read on the console interface
512 within "Boot Delay" after reset.
515 This can be used to pass arguments to the bootm
516 command. The value of CONFIG_BOOTARGS goes into the
517 environment value "bootargs".
519 CONFIG_RAMBOOT and CONFIG_NFSBOOT
520 The value of these goes into the environment as
521 "ramboot" and "nfsboot" respectively, and can be used
522 as a convenience, when switching between booting from
528 When this option is #defined, the existence of the
529 environment variable "preboot" will be checked
530 immediately before starting the CONFIG_BOOTDELAY
531 countdown and/or running the auto-boot command resp.
532 entering interactive mode.
534 This feature is especially useful when "preboot" is
535 automatically generated or modified. For an example
536 see the LWMON board specific code: here "preboot" is
537 modified when the user holds down a certain
538 combination of keys on the (special) keyboard when
541 - Serial Download Echo Mode:
543 If defined to 1, all characters received during a
544 serial download (using the "loads" command) are
545 echoed back. This might be needed by some terminal
546 emulations (like "cu"), but may as well just take
547 time on others. This setting #define's the initial
548 value of the "loads_echo" environment variable.
550 - Kgdb Serial Baudrate: (if CONFIG_CMD_KGDB is defined)
552 Select one of the baudrates listed in
553 CFG_BAUDRATE_TABLE, see below.
556 Monitor commands can be included or excluded
557 from the build by using the #include files
558 "config_cmd_all.h" and #undef'ing unwanted
559 commands, or using "config_cmd_default.h"
560 and augmenting with additional #define's
563 The default command configuration includes all commands
564 except those marked below with a "*".
566 CONFIG_CMD_ASKENV * ask for env variable
567 CONFIG_CMD_AUTOSCRIPT Autoscript Support
568 CONFIG_CMD_BDI bdinfo
569 CONFIG_CMD_BEDBUG * Include BedBug Debugger
570 CONFIG_CMD_BMP * BMP support
571 CONFIG_CMD_BSP * Board specific commands
572 CONFIG_CMD_BOOTD bootd
573 CONFIG_CMD_CACHE * icache, dcache
574 CONFIG_CMD_CONSOLE coninfo
575 CONFIG_CMD_DATE * support for RTC, date/time...
576 CONFIG_CMD_DHCP * DHCP support
577 CONFIG_CMD_DIAG * Diagnostics
578 CONFIG_CMD_DOC * Disk-On-Chip Support
579 CONFIG_CMD_DTT * Digital Therm and Thermostat
580 CONFIG_CMD_ECHO echo arguments
581 CONFIG_CMD_EEPROM * EEPROM read/write support
582 CONFIG_CMD_ELF * bootelf, bootvx
583 CONFIG_CMD_ENV saveenv
584 CONFIG_CMD_FDC * Floppy Disk Support
585 CONFIG_CMD_FAT * FAT partition support
586 CONFIG_CMD_FDOS * Dos diskette Support
587 CONFIG_CMD_FLASH flinfo, erase, protect
588 CONFIG_CMD_FPGA FPGA device initialization support
589 CONFIG_CMD_HWFLOW * RTS/CTS hw flow control
590 CONFIG_CMD_I2C * I2C serial bus support
591 CONFIG_CMD_IDE * IDE harddisk support
592 CONFIG_CMD_IMI iminfo
593 CONFIG_CMD_IMLS List all found images
594 CONFIG_CMD_IMMAP * IMMR dump support
595 CONFIG_CMD_IRQ * irqinfo
596 CONFIG_CMD_ITEST Integer/string test of 2 values
597 CONFIG_CMD_JFFS2 * JFFS2 Support
598 CONFIG_CMD_KGDB * kgdb
599 CONFIG_CMD_LOADB loadb
600 CONFIG_CMD_LOADS loads
601 CONFIG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base,
603 CONFIG_CMD_MISC Misc functions like sleep etc
604 CONFIG_CMD_MMC * MMC memory mapped support
605 CONFIG_CMD_MII * MII utility commands
606 CONFIG_CMD_NAND * NAND support
607 CONFIG_CMD_NET bootp, tftpboot, rarpboot
608 CONFIG_CMD_PCI * pciinfo
609 CONFIG_CMD_PCMCIA * PCMCIA support
610 CONFIG_CMD_PING * send ICMP ECHO_REQUEST to network
612 CONFIG_CMD_PORTIO * Port I/O
613 CONFIG_CMD_REGINFO * Register dump
614 CONFIG_CMD_RUN run command in env variable
615 CONFIG_CMD_SAVES * save S record dump
616 CONFIG_CMD_SCSI * SCSI Support
617 CONFIG_CMD_SDRAM * print SDRAM configuration information
618 (requires CONFIG_CMD_I2C)
619 CONFIG_CMD_SETGETDCR Support for DCR Register access
621 CONFIG_CMD_SPI * SPI serial bus support
622 CONFIG_CMD_USB * USB support
623 CONFIG_CMD_VFD * VFD support (TRAB)
624 CONFIG_CMD_BSP * Board SPecific functions
625 CONFIG_CMD_CDP * Cisco Discover Protocol support
626 CONFIG_CMD_FSL * Microblaze FSL support
629 EXAMPLE: If you want all functions except of network
630 support you can write:
632 #include "config_cmd_all.h"
633 #undef CONFIG_CMD_NET
636 fdt (flattened device tree) command: CONFIG_OF_LIBFDT
638 Note: Don't enable the "icache" and "dcache" commands
639 (configuration option CONFIG_CMD_CACHE) unless you know
640 what you (and your U-Boot users) are doing. Data
641 cache cannot be enabled on systems like the 8xx or
642 8260 (where accesses to the IMMR region must be
643 uncached), and it cannot be disabled on all other
644 systems where we (mis-) use the data cache to hold an
645 initial stack and some data.
648 XXX - this list needs to get updated!
652 If this variable is defined, it enables watchdog
653 support. There must be support in the platform specific
654 code for a watchdog. For the 8xx and 8260 CPUs, the
655 SIU Watchdog feature is enabled in the SYPCR
659 CONFIG_VERSION_VARIABLE
660 If this variable is defined, an environment variable
661 named "ver" is created by U-Boot showing the U-Boot
662 version as printed by the "version" command.
663 This variable is readonly.
667 When CONFIG_CMD_DATE is selected, the type of the RTC
668 has to be selected, too. Define exactly one of the
671 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx
672 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC
673 CONFIG_RTC_MC146818 - use MC146818 RTC
674 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC
675 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC
676 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC
677 CONFIG_RTC_DS164x - use Dallas DS164x RTC
678 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC
679 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC
680 CFG_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337
682 Note that if the RTC uses I2C, then the I2C interface
683 must also be configured. See I2C Support, below.
687 When CONFIG_TIMESTAMP is selected, the timestamp
688 (date and time) of an image is printed by image
689 commands like bootm or iminfo. This option is
690 automatically enabled when you select CONFIG_CMD_DATE .
693 CONFIG_MAC_PARTITION and/or CONFIG_DOS_PARTITION
694 and/or CONFIG_ISO_PARTITION
696 If IDE or SCSI support is enabled (CONFIG_CMD_IDE or
697 CONFIG_CMD_SCSI) you must configure support for at
698 least one partition type as well.
701 CONFIG_IDE_RESET_ROUTINE - this is defined in several
702 board configurations files but used nowhere!
704 CONFIG_IDE_RESET - is this is defined, IDE Reset will
705 be performed by calling the function
706 ide_set_reset(int reset)
707 which has to be defined in a board specific file
712 Set this to enable ATAPI support.
717 Set this to enable support for disks larger than 137GB
718 Also look at CFG_64BIT_LBA ,CFG_64BIT_VSPRINTF and CFG_64BIT_STRTOUL
719 Whithout these , LBA48 support uses 32bit variables and will 'only'
720 support disks up to 2.1TB.
723 When enabled, makes the IDE subsystem use 64bit sector addresses.
727 At the moment only there is only support for the
728 SYM53C8XX SCSI controller; define
729 CONFIG_SCSI_SYM53C8XX to enable it.
731 CFG_SCSI_MAX_LUN [8], CFG_SCSI_MAX_SCSI_ID [7] and
732 CFG_SCSI_MAX_DEVICE [CFG_SCSI_MAX_SCSI_ID *
733 CFG_SCSI_MAX_LUN] can be adjusted to define the
734 maximum numbers of LUNs, SCSI ID's and target
736 CFG_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz)
738 - NETWORK Support (PCI):
740 Support for Intel 8254x gigabit chips.
742 CONFIG_E1000_FALLBACK_MAC
743 default MAC for empty eeprom after production.
746 Support for Intel 82557/82559/82559ER chips.
747 Optional CONFIG_EEPRO100_SROM_WRITE enables eeprom
748 write routine for first time initialisation.
751 Support for Digital 2114x chips.
752 Optional CONFIG_TULIP_SELECT_MEDIA for board specific
753 modem chip initialisation (KS8761/QS6611).
756 Support for National dp83815 chips.
759 Support for National dp8382[01] gigabit chips.
761 - NETWORK Support (other):
763 CONFIG_DRIVER_LAN91C96
764 Support for SMSC's LAN91C96 chips.
767 Define this to hold the physical address
768 of the LAN91C96's I/O space
770 CONFIG_LAN91C96_USE_32_BIT
771 Define this to enable 32 bit addressing
773 CONFIG_DRIVER_SMC91111
774 Support for SMSC's LAN91C111 chip
777 Define this to hold the physical address
778 of the device (I/O space)
780 CONFIG_SMC_USE_32_BIT
781 Define this if data bus is 32 bits
783 CONFIG_SMC_USE_IOFUNCS
784 Define this to use i/o functions instead of macros
785 (some hardware wont work with macros)
788 At the moment only the UHCI host controller is
789 supported (PIP405, MIP405, MPC5200); define
790 CONFIG_USB_UHCI to enable it.
791 define CONFIG_USB_KEYBOARD to enable the USB Keyboard
792 and define CONFIG_USB_STORAGE to enable the USB
795 Supported are USB Keyboards and USB Floppy drives
797 MPC5200 USB requires additional defines:
799 for 528 MHz Clock: 0x0001bbbb
801 for differential drivers: 0x00001000
802 for single ended drivers: 0x00005000
804 May be defined to allow interrupt polling
805 instead of using asynchronous interrupts
808 Define the below if you wish to use the USB console.
809 Once firmware is rebuilt from a serial console issue the
810 command "setenv stdin usbtty; setenv stdout usbtty" and
811 attach your usb cable. The Unix command "dmesg" should print
812 it has found a new device. The environment variable usbtty
813 can be set to gserial or cdc_acm to enable your device to
814 appear to a USB host as a Linux gserial device or a
815 Common Device Class Abstract Control Model serial device.
816 If you select usbtty = gserial you should be able to enumerate
818 # modprobe usbserial vendor=0xVendorID product=0xProductID
819 else if using cdc_acm, simply setting the environment
820 variable usbtty to be cdc_acm should suffice. The following
821 might be defined in YourBoardName.h
824 Define this to build a UDC device
827 Define this to have a tty type of device available to
828 talk to the UDC device
830 CFG_CONSOLE_IS_IN_ENV
831 Define this if you want stdin, stdout &/or stderr to
835 CFG_USB_EXTC_CLK 0xBLAH
836 Derive USB clock from external clock "blah"
837 - CFG_USB_EXTC_CLK 0x02
839 CFG_USB_BRG_CLK 0xBLAH
840 Derive USB clock from brgclk
841 - CFG_USB_BRG_CLK 0x04
843 If you have a USB-IF assigned VendorID then you may wish to
844 define your own vendor specific values either in BoardName.h
845 or directly in usbd_vendor_info.h. If you don't define
846 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME,
847 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot
848 should pretend to be a Linux device to it's target host.
850 CONFIG_USBD_MANUFACTURER
851 Define this string as the name of your company for
852 - CONFIG_USBD_MANUFACTURER "my company"
854 CONFIG_USBD_PRODUCT_NAME
855 Define this string as the name of your product
856 - CONFIG_USBD_PRODUCT_NAME "acme usb device"
859 Define this as your assigned Vendor ID from the USB
860 Implementors Forum. This *must* be a genuine Vendor ID
861 to avoid polluting the USB namespace.
862 - CONFIG_USBD_VENDORID 0xFFFF
864 CONFIG_USBD_PRODUCTID
865 Define this as the unique Product ID
867 - CONFIG_USBD_PRODUCTID 0xFFFF
871 The MMC controller on the Intel PXA is supported. To
872 enable this define CONFIG_MMC. The MMC can be
873 accessed from the boot prompt by mapping the device
874 to physical memory similar to flash. Command line is
875 enabled with CONFIG_CMD_MMC. The MMC driver also works with
876 the FAT fs. This is enabled with CONFIG_CMD_FAT.
878 - Journaling Flash filesystem support:
879 CONFIG_JFFS2_NAND, CONFIG_JFFS2_NAND_OFF, CONFIG_JFFS2_NAND_SIZE,
880 CONFIG_JFFS2_NAND_DEV
881 Define these for a default partition on a NAND device
883 CFG_JFFS2_FIRST_SECTOR,
884 CFG_JFFS2_FIRST_BANK, CFG_JFFS2_NUM_BANKS
885 Define these for a default partition on a NOR device
888 Define this to create an own partition. You have to provide a
889 function struct part_info* jffs2_part_info(int part_num)
891 If you define only one JFFS2 partition you may also want to
892 #define CFG_JFFS_SINGLE_PART 1
893 to disable the command chpart. This is the default when you
894 have not defined a custom partition
899 Define this to enable standard (PC-Style) keyboard
903 Standard PC keyboard driver with US (is default) and
904 GERMAN key layout (switch via environment 'keymap=de') support.
905 Export function i8042_kbd_init, i8042_tstc and i8042_getc
906 for cfb_console. Supports cursor blinking.
911 Define this to enable video support (for output to
916 Enable Chips & Technologies 69000 Video chip
918 CONFIG_VIDEO_SMI_LYNXEM
919 Enable Silicon Motion SMI 712/710/810 Video chip. The
920 video output is selected via environment 'videoout'
921 (1 = LCD and 2 = CRT). If videoout is undefined, CRT is
924 For the CT69000 and SMI_LYNXEM drivers, videomode is
925 selected via environment 'videomode'. Two diferent ways
927 - "videomode=num" 'num' is a standard LiLo mode numbers.
928 Following standard modes are supported (* is default):
930 Colors 640x480 800x600 1024x768 1152x864 1280x1024
931 -------------+---------------------------------------------
932 8 bits | 0x301* 0x303 0x305 0x161 0x307
933 15 bits | 0x310 0x313 0x316 0x162 0x319
934 16 bits | 0x311 0x314 0x317 0x163 0x31A
935 24 bits | 0x312 0x315 0x318 ? 0x31B
936 -------------+---------------------------------------------
937 (i.e. setenv videomode 317; saveenv; reset;)
939 - "videomode=bootargs" all the video parameters are parsed
940 from the bootargs. (See drivers/video/videomodes.c)
943 CONFIG_VIDEO_SED13806
944 Enable Epson SED13806 driver. This driver supports 8bpp
945 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP
946 or CONFIG_VIDEO_SED13806_16BPP
951 Define this to enable a custom keyboard support.
952 This simply calls drv_keyboard_init() which must be
953 defined in your board-specific files.
954 The only board using this so far is RBC823.
956 - LCD Support: CONFIG_LCD
958 Define this to enable LCD support (for output to LCD
959 display); also select one of the supported displays
960 by defining one of these:
962 CONFIG_NEC_NL6448AC33:
964 NEC NL6448AC33-18. Active, color, single scan.
966 CONFIG_NEC_NL6448BC20
968 NEC NL6448BC20-08. 6.5", 640x480.
969 Active, color, single scan.
971 CONFIG_NEC_NL6448BC33_54
973 NEC NL6448BC33-54. 10.4", 640x480.
974 Active, color, single scan.
978 Sharp 320x240. Active, color, single scan.
979 It isn't 16x9, and I am not sure what it is.
981 CONFIG_SHARP_LQ64D341
983 Sharp LQ64D341 display, 640x480.
984 Active, color, single scan.
988 HLD1045 display, 640x480.
989 Active, color, single scan.
993 Optrex CBL50840-2 NF-FW 99 22 M5
995 Hitachi LMG6912RPFC-00T
999 320x240. Black & white.
1001 Normally display is black on white background; define
1002 CFG_WHITE_ON_BLACK to get it inverted.
1004 - Splash Screen Support: CONFIG_SPLASH_SCREEN
1006 If this option is set, the environment is checked for
1007 a variable "splashimage". If found, the usual display
1008 of logo, copyright and system information on the LCD
1009 is suppressed and the BMP image at the address
1010 specified in "splashimage" is loaded instead. The
1011 console is redirected to the "nulldev", too. This
1012 allows for a "silent" boot where a splash screen is
1013 loaded very quickly after power-on.
1015 - Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP
1017 If this option is set, additionally to standard BMP
1018 images, gzipped BMP images can be displayed via the
1019 splashscreen support or the bmp command.
1021 - Compression support:
1024 If this option is set, support for bzip2 compressed
1025 images is included. If not, only uncompressed and gzip
1026 compressed images are supported.
1028 NOTE: the bzip2 algorithm requires a lot of RAM, so
1029 the malloc area (as defined by CFG_MALLOC_LEN) should
1035 The address of PHY on MII bus.
1037 CONFIG_PHY_CLOCK_FREQ (ppc4xx)
1039 The clock frequency of the MII bus
1043 If this option is set, support for speed/duplex
1044 detection of Gigabit PHY is included.
1046 CONFIG_PHY_RESET_DELAY
1048 Some PHY like Intel LXT971A need extra delay after
1049 reset before any MII register access is possible.
1050 For such PHY, set this option to the usec delay
1051 required. (minimum 300usec for LXT971A)
1053 CONFIG_PHY_CMD_DELAY (ppc4xx)
1055 Some PHY like Intel LXT971A need extra delay after
1056 command issued before MII status register can be read
1063 Define a default value for ethernet address to use
1064 for the respective ethernet interface, in case this
1065 is not determined automatically.
1070 Define a default value for the IP address to use for
1071 the default ethernet interface, in case this is not
1072 determined through e.g. bootp.
1074 - Server IP address:
1077 Defines a default value for theIP address of a TFTP
1078 server to contact when using the "tftboot" command.
1080 - Multicast TFTP Mode:
1083 Defines whether you want to support multicast TFTP as per
1084 rfc-2090; for example to work with atftp. Lets lots of targets
1085 tftp down the same boot image concurrently. Note: the ethernet
1086 driver in use must provide a function: mcast() to join/leave a
1089 CONFIG_BOOTP_RANDOM_DELAY
1090 - BOOTP Recovery Mode:
1091 CONFIG_BOOTP_RANDOM_DELAY
1093 If you have many targets in a network that try to
1094 boot using BOOTP, you may want to avoid that all
1095 systems send out BOOTP requests at precisely the same
1096 moment (which would happen for instance at recovery
1097 from a power failure, when all systems will try to
1098 boot, thus flooding the BOOTP server. Defining
1099 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
1100 inserted before sending out BOOTP requests. The
1101 following delays are inserted then:
1103 1st BOOTP request: delay 0 ... 1 sec
1104 2nd BOOTP request: delay 0 ... 2 sec
1105 3rd BOOTP request: delay 0 ... 4 sec
1107 BOOTP requests: delay 0 ... 8 sec
1109 - DHCP Advanced Options:
1110 You can fine tune the DHCP functionality by defining
1111 CONFIG_BOOTP_* symbols:
1113 CONFIG_BOOTP_SUBNETMASK
1114 CONFIG_BOOTP_GATEWAY
1115 CONFIG_BOOTP_HOSTNAME
1116 CONFIG_BOOTP_NISDOMAIN
1117 CONFIG_BOOTP_BOOTPATH
1118 CONFIG_BOOTP_BOOTFILESIZE
1121 CONFIG_BOOTP_SEND_HOSTNAME
1122 CONFIG_BOOTP_NTPSERVER
1123 CONFIG_BOOTP_TIMEOFFSET
1124 CONFIG_BOOTP_VENDOREX
1126 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip
1127 environment variable, not the BOOTP server.
1129 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS
1130 serverip from a DHCP server, it is possible that more
1131 than one DNS serverip is offered to the client.
1132 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS
1133 serverip will be stored in the additional environment
1134 variable "dnsip2". The first DNS serverip is always
1135 stored in the variable "dnsip", when CONFIG_BOOTP_DNS
1138 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable
1139 to do a dynamic update of a DNS server. To do this, they
1140 need the hostname of the DHCP requester.
1141 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content
1142 of the "hostname" environment variable is passed as
1143 option 12 to the DHCP server.
1145 CONFIG_BOOTP_DHCP_REQUEST_DELAY
1147 A 32bit value in microseconds for a delay between
1148 receiving a "DHCP Offer" and sending the "DHCP Request".
1149 This fixes a problem with certain DHCP servers that don't
1150 respond 100% of the time to a "DHCP request". E.g. On an
1151 AT91RM9200 processor running at 180MHz, this delay needed
1152 to be *at least* 15,000 usec before a Windows Server 2003
1153 DHCP server would reply 100% of the time. I recommend at
1154 least 50,000 usec to be safe. The alternative is to hope
1155 that one of the retries will be successful but note that
1156 the DHCP timeout and retry process takes a longer than
1160 CONFIG_CDP_DEVICE_ID
1162 The device id used in CDP trigger frames.
1164 CONFIG_CDP_DEVICE_ID_PREFIX
1166 A two character string which is prefixed to the MAC address
1171 A printf format string which contains the ascii name of
1172 the port. Normally is set to "eth%d" which sets
1173 eth0 for the first ethernet, eth1 for the second etc.
1175 CONFIG_CDP_CAPABILITIES
1177 A 32bit integer which indicates the device capabilities;
1178 0x00000010 for a normal host which does not forwards.
1182 An ascii string containing the version of the software.
1186 An ascii string containing the name of the platform.
1190 A 32bit integer sent on the trigger.
1192 CONFIG_CDP_POWER_CONSUMPTION
1194 A 16bit integer containing the power consumption of the
1195 device in .1 of milliwatts.
1197 CONFIG_CDP_APPLIANCE_VLAN_TYPE
1199 A byte containing the id of the VLAN.
1201 - Status LED: CONFIG_STATUS_LED
1203 Several configurations allow to display the current
1204 status using a LED. For instance, the LED will blink
1205 fast while running U-Boot code, stop blinking as
1206 soon as a reply to a BOOTP request was received, and
1207 start blinking slow once the Linux kernel is running
1208 (supported by a status LED driver in the Linux
1209 kernel). Defining CONFIG_STATUS_LED enables this
1212 - CAN Support: CONFIG_CAN_DRIVER
1214 Defining CONFIG_CAN_DRIVER enables CAN driver support
1215 on those systems that support this (optional)
1216 feature, like the TQM8xxL modules.
1218 - I2C Support: CONFIG_HARD_I2C | CONFIG_SOFT_I2C
1220 These enable I2C serial bus commands. Defining either of
1221 (but not both of) CONFIG_HARD_I2C or CONFIG_SOFT_I2C will
1222 include the appropriate I2C driver for the selected cpu.
1224 This will allow you to use i2c commands at the u-boot
1225 command line (as long as you set CONFIG_CMD_I2C in
1226 CONFIG_COMMANDS) and communicate with i2c based realtime
1227 clock chips. See common/cmd_i2c.c for a description of the
1228 command line interface.
1230 CONFIG_I2C_CMD_TREE is a recommended option that places
1231 all I2C commands under a single 'i2c' root command. The
1232 older 'imm', 'imd', 'iprobe' etc. commands are considered
1233 deprecated and may disappear in the future.
1235 CONFIG_HARD_I2C selects a hardware I2C controller.
1237 CONFIG_SOFT_I2C configures u-boot to use a software (aka
1238 bit-banging) driver instead of CPM or similar hardware
1241 There are several other quantities that must also be
1242 defined when you define CONFIG_HARD_I2C or CONFIG_SOFT_I2C.
1244 In both cases you will need to define CFG_I2C_SPEED
1245 to be the frequency (in Hz) at which you wish your i2c bus
1246 to run and CFG_I2C_SLAVE to be the address of this node (ie
1247 the cpu's i2c node address).
1249 Now, the u-boot i2c code for the mpc8xx (cpu/mpc8xx/i2c.c)
1250 sets the cpu up as a master node and so its address should
1251 therefore be cleared to 0 (See, eg, MPC823e User's Manual
1252 p.16-473). So, set CFG_I2C_SLAVE to 0.
1254 That's all that's required for CONFIG_HARD_I2C.
1256 If you use the software i2c interface (CONFIG_SOFT_I2C)
1257 then the following macros need to be defined (examples are
1258 from include/configs/lwmon.h):
1262 (Optional). Any commands necessary to enable the I2C
1263 controller or configure ports.
1265 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
1269 (Only for MPC8260 CPU). The I/O port to use (the code
1270 assumes both bits are on the same port). Valid values
1271 are 0..3 for ports A..D.
1275 The code necessary to make the I2C data line active
1276 (driven). If the data line is open collector, this
1279 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
1283 The code necessary to make the I2C data line tri-stated
1284 (inactive). If the data line is open collector, this
1287 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
1291 Code that returns TRUE if the I2C data line is high,
1294 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
1298 If <bit> is TRUE, sets the I2C data line high. If it
1299 is FALSE, it clears it (low).
1301 eg: #define I2C_SDA(bit) \
1302 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
1303 else immr->im_cpm.cp_pbdat &= ~PB_SDA
1307 If <bit> is TRUE, sets the I2C clock line high. If it
1308 is FALSE, it clears it (low).
1310 eg: #define I2C_SCL(bit) \
1311 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
1312 else immr->im_cpm.cp_pbdat &= ~PB_SCL
1316 This delay is invoked four times per clock cycle so this
1317 controls the rate of data transfer. The data rate thus
1318 is 1 / (I2C_DELAY * 4). Often defined to be something
1321 #define I2C_DELAY udelay(2)
1325 When a board is reset during an i2c bus transfer
1326 chips might think that the current transfer is still
1327 in progress. On some boards it is possible to access
1328 the i2c SCLK line directly, either by using the
1329 processor pin as a GPIO or by having a second pin
1330 connected to the bus. If this option is defined a
1331 custom i2c_init_board() routine in boards/xxx/board.c
1332 is run early in the boot sequence.
1334 CONFIG_I2CFAST (PPC405GP|PPC405EP only)
1336 This option enables configuration of bi_iic_fast[] flags
1337 in u-boot bd_info structure based on u-boot environment
1338 variable "i2cfast". (see also i2cfast)
1340 CONFIG_I2C_MULTI_BUS
1342 This option allows the use of multiple I2C buses, each of which
1343 must have a controller. At any point in time, only one bus is
1344 active. To switch to a different bus, use the 'i2c dev' command.
1345 Note that bus numbering is zero-based.
1349 This option specifies a list of I2C devices that will be skipped
1350 when the 'i2c probe' command is issued (or 'iprobe' using the legacy
1351 command). If CONFIG_I2C_MULTI_BUS is set, specify a list of bus-device
1352 pairs. Otherwise, specify a 1D array of device addresses
1355 #undef CONFIG_I2C_MULTI_BUS
1356 #define CFG_I2C_NOPROBES {0x50,0x68}
1358 will skip addresses 0x50 and 0x68 on a board with one I2C bus
1360 #define CONFIG_I2C_MULTI_BUS
1361 #define CFG_I2C_MULTI_NOPROBES {{0,0x50},{0,0x68},{1,0x54}}
1363 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1
1367 If defined, then this indicates the I2C bus number for DDR SPD.
1368 If not defined, then U-Boot assumes that SPD is on I2C bus 0.
1372 If defined, then this indicates the I2C bus number for the RTC.
1373 If not defined, then U-Boot assumes that RTC is on I2C bus 0.
1377 If defined, then this indicates the I2C bus number for the DTT.
1378 If not defined, then U-Boot assumes that DTT is on I2C bus 0.
1382 Define this option if you want to use Freescale's I2C driver in
1383 drivers/i2c/fsl_i2c.c.
1386 - SPI Support: CONFIG_SPI
1388 Enables SPI driver (so far only tested with
1389 SPI EEPROM, also an instance works with Crystal A/D and
1390 D/As on the SACSng board)
1394 Enables extended (16-bit) SPI EEPROM addressing.
1395 (symmetrical to CONFIG_I2C_X)
1399 Enables a software (bit-bang) SPI driver rather than
1400 using hardware support. This is a general purpose
1401 driver that only requires three general I/O port pins
1402 (two outputs, one input) to function. If this is
1403 defined, the board configuration must define several
1404 SPI configuration items (port pins to use, etc). For
1405 an example, see include/configs/sacsng.h.
1409 Enables a hardware SPI driver for general-purpose reads
1410 and writes. As with CONFIG_SOFT_SPI, the board configuration
1411 must define a list of chip-select function pointers.
1412 Currently supported on some MPC8xxx processors. For an
1413 example, see include/configs/mpc8349emds.h.
1415 - FPGA Support: CONFIG_FPGA
1417 Enables FPGA subsystem.
1419 CONFIG_FPGA_<vendor>
1421 Enables support for specific chip vendors.
1424 CONFIG_FPGA_<family>
1426 Enables support for FPGA family.
1427 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX)
1431 Specify the number of FPGA devices to support.
1433 CFG_FPGA_PROG_FEEDBACK
1435 Enable printing of hash marks during FPGA configuration.
1439 Enable checks on FPGA configuration interface busy
1440 status by the configuration function. This option
1441 will require a board or device specific function to
1446 If defined, a function that provides delays in the FPGA
1447 configuration driver.
1449 CFG_FPGA_CHECK_CTRLC
1450 Allow Control-C to interrupt FPGA configuration
1452 CFG_FPGA_CHECK_ERROR
1454 Check for configuration errors during FPGA bitfile
1455 loading. For example, abort during Virtex II
1456 configuration if the INIT_B line goes low (which
1457 indicated a CRC error).
1461 Maximum time to wait for the INIT_B line to deassert
1462 after PROB_B has been deasserted during a Virtex II
1463 FPGA configuration sequence. The default time is 500
1468 Maximum time to wait for BUSY to deassert during
1469 Virtex II FPGA configuration. The default is 5 mS.
1471 CFG_FPGA_WAIT_CONFIG
1473 Time to wait after FPGA configuration. The default is
1476 - Configuration Management:
1479 If defined, this string will be added to the U-Boot
1480 version information (U_BOOT_VERSION)
1482 - Vendor Parameter Protection:
1484 U-Boot considers the values of the environment
1485 variables "serial#" (Board Serial Number) and
1486 "ethaddr" (Ethernet Address) to be parameters that
1487 are set once by the board vendor / manufacturer, and
1488 protects these variables from casual modification by
1489 the user. Once set, these variables are read-only,
1490 and write or delete attempts are rejected. You can
1491 change this behviour:
1493 If CONFIG_ENV_OVERWRITE is #defined in your config
1494 file, the write protection for vendor parameters is
1495 completely disabled. Anybody can change or delete
1498 Alternatively, if you #define _both_ CONFIG_ETHADDR
1499 _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
1500 ethernet address is installed in the environment,
1501 which can be changed exactly ONCE by the user. [The
1502 serial# is unaffected by this, i. e. it remains
1508 Define this variable to enable the reservation of
1509 "protected RAM", i. e. RAM which is not overwritten
1510 by U-Boot. Define CONFIG_PRAM to hold the number of
1511 kB you want to reserve for pRAM. You can overwrite
1512 this default value by defining an environment
1513 variable "pram" to the number of kB you want to
1514 reserve. Note that the board info structure will
1515 still show the full amount of RAM. If pRAM is
1516 reserved, a new environment variable "mem" will
1517 automatically be defined to hold the amount of
1518 remaining RAM in a form that can be passed as boot
1519 argument to Linux, for instance like that:
1521 setenv bootargs ... mem=\${mem}
1524 This way you can tell Linux not to use this memory,
1525 either, which results in a memory region that will
1526 not be affected by reboots.
1528 *WARNING* If your board configuration uses automatic
1529 detection of the RAM size, you must make sure that
1530 this memory test is non-destructive. So far, the
1531 following board configurations are known to be
1534 ETX094, IVMS8, IVML24, SPD8xx, TQM8xxL,
1535 HERMES, IP860, RPXlite, LWMON, LANTEC,
1536 PCU_E, FLAGADM, TQM8260
1541 Define this variable to stop the system in case of a
1542 fatal error, so that you have to reset it manually.
1543 This is probably NOT a good idea for an embedded
1544 system where you want to system to reboot
1545 automatically as fast as possible, but it may be
1546 useful during development since you can try to debug
1547 the conditions that lead to the situation.
1549 CONFIG_NET_RETRY_COUNT
1551 This variable defines the number of retries for
1552 network operations like ARP, RARP, TFTP, or BOOTP
1553 before giving up the operation. If not defined, a
1554 default value of 5 is used.
1556 - Command Interpreter:
1557 CONFIG_AUTO_COMPLETE
1559 Enable auto completion of commands using TAB.
1561 Note that this feature has NOT been implemented yet
1562 for the "hush" shell.
1567 Define this variable to enable the "hush" shell (from
1568 Busybox) as command line interpreter, thus enabling
1569 powerful command line syntax like
1570 if...then...else...fi conditionals or `&&' and '||'
1571 constructs ("shell scripts").
1573 If undefined, you get the old, much simpler behaviour
1574 with a somewhat smaller memory footprint.
1579 This defines the secondary prompt string, which is
1580 printed when the command interpreter needs more input
1581 to complete a command. Usually "> ".
1585 In the current implementation, the local variables
1586 space and global environment variables space are
1587 separated. Local variables are those you define by
1588 simply typing `name=value'. To access a local
1589 variable later on, you have write `$name' or
1590 `${name}'; to execute the contents of a variable
1591 directly type `$name' at the command prompt.
1593 Global environment variables are those you use
1594 setenv/printenv to work with. To run a command stored
1595 in such a variable, you need to use the run command,
1596 and you must not use the '$' sign to access them.
1598 To store commands and special characters in a
1599 variable, please use double quotation marks
1600 surrounding the whole text of the variable, instead
1601 of the backslashes before semicolons and special
1604 - Commandline Editing and History:
1605 CONFIG_CMDLINE_EDITING
1607 Enable editiong and History functions for interactive
1608 commandline input operations
1610 - Default Environment:
1611 CONFIG_EXTRA_ENV_SETTINGS
1613 Define this to contain any number of null terminated
1614 strings (variable = value pairs) that will be part of
1615 the default environment compiled into the boot image.
1617 For example, place something like this in your
1618 board's config file:
1620 #define CONFIG_EXTRA_ENV_SETTINGS \
1624 Warning: This method is based on knowledge about the
1625 internal format how the environment is stored by the
1626 U-Boot code. This is NOT an official, exported
1627 interface! Although it is unlikely that this format
1628 will change soon, there is no guarantee either.
1629 You better know what you are doing here.
1631 Note: overly (ab)use of the default environment is
1632 discouraged. Make sure to check other ways to preset
1633 the environment like the autoscript function or the
1636 - DataFlash Support:
1637 CONFIG_HAS_DATAFLASH
1639 Defining this option enables DataFlash features and
1640 allows to read/write in Dataflash via the standard
1643 - SystemACE Support:
1646 Adding this option adds support for Xilinx SystemACE
1647 chips attached via some sort of local bus. The address
1648 of the chip must alsh be defined in the
1649 CFG_SYSTEMACE_BASE macro. For example:
1651 #define CONFIG_SYSTEMACE
1652 #define CFG_SYSTEMACE_BASE 0xf0000000
1654 When SystemACE support is added, the "ace" device type
1655 becomes available to the fat commands, i.e. fatls.
1657 - TFTP Fixed UDP Port:
1660 If this is defined, the environment variable tftpsrcp
1661 is used to supply the TFTP UDP source port value.
1662 If tftpsrcp isn't defined, the normal pseudo-random port
1663 number generator is used.
1665 Also, the environment variable tftpdstp is used to supply
1666 the TFTP UDP destination port value. If tftpdstp isn't
1667 defined, the normal port 69 is used.
1669 The purpose for tftpsrcp is to allow a TFTP server to
1670 blindly start the TFTP transfer using the pre-configured
1671 target IP address and UDP port. This has the effect of
1672 "punching through" the (Windows XP) firewall, allowing
1673 the remainder of the TFTP transfer to proceed normally.
1674 A better solution is to properly configure the firewall,
1675 but sometimes that is not allowed.
1677 - Show boot progress:
1678 CONFIG_SHOW_BOOT_PROGRESS
1680 Defining this option allows to add some board-
1681 specific code (calling a user-provided function
1682 "show_boot_progress(int)") that enables you to show
1683 the system's boot progress on some display (for
1684 example, some LED's) on your board. At the moment,
1685 the following checkpoints are implemented:
1687 Legacy uImage format:
1690 1 common/cmd_bootm.c before attempting to boot an image
1691 -1 common/cmd_bootm.c Image header has bad magic number
1692 2 common/cmd_bootm.c Image header has correct magic number
1693 -2 common/cmd_bootm.c Image header has bad checksum
1694 3 common/cmd_bootm.c Image header has correct checksum
1695 -3 common/cmd_bootm.c Image data has bad checksum
1696 4 common/cmd_bootm.c Image data has correct checksum
1697 -4 common/cmd_bootm.c Image is for unsupported architecture
1698 5 common/cmd_bootm.c Architecture check OK
1699 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi)
1700 6 common/cmd_bootm.c Image Type check OK
1701 -6 common/cmd_bootm.c gunzip uncompression error
1702 -7 common/cmd_bootm.c Unimplemented compression type
1703 7 common/cmd_bootm.c Uncompression OK
1704 8 common/cmd_bootm.c No uncompress/copy overwrite error
1705 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX)
1707 9 common/image.c Start initial ramdisk verification
1708 -10 common/image.c Ramdisk header has bad magic number
1709 -11 common/image.c Ramdisk header has bad checksum
1710 10 common/image.c Ramdisk header is OK
1711 -12 common/image.c Ramdisk data has bad checksum
1712 11 common/image.c Ramdisk data has correct checksum
1713 12 common/image.c Ramdisk verification complete, start loading
1714 -13 common/image.c Wrong Image Type (not PPC Linux Ramdisk)
1715 13 common/image.c Start multifile image verification
1716 14 common/image.c No initial ramdisk, no multifile, continue.
1718 15 lib_<arch>/bootm.c All preparation done, transferring control to OS
1720 -30 lib_ppc/board.c Fatal error, hang the system
1721 -31 post/post.c POST test failed, detected by post_output_backlog()
1722 -32 post/post.c POST test failed, detected by post_run_single()
1724 34 common/cmd_doc.c before loading a Image from a DOC device
1725 -35 common/cmd_doc.c Bad usage of "doc" command
1726 35 common/cmd_doc.c correct usage of "doc" command
1727 -36 common/cmd_doc.c No boot device
1728 36 common/cmd_doc.c correct boot device
1729 -37 common/cmd_doc.c Unknown Chip ID on boot device
1730 37 common/cmd_doc.c correct chip ID found, device available
1731 -38 common/cmd_doc.c Read Error on boot device
1732 38 common/cmd_doc.c reading Image header from DOC device OK
1733 -39 common/cmd_doc.c Image header has bad magic number
1734 39 common/cmd_doc.c Image header has correct magic number
1735 -40 common/cmd_doc.c Error reading Image from DOC device
1736 40 common/cmd_doc.c Image header has correct magic number
1737 41 common/cmd_ide.c before loading a Image from a IDE device
1738 -42 common/cmd_ide.c Bad usage of "ide" command
1739 42 common/cmd_ide.c correct usage of "ide" command
1740 -43 common/cmd_ide.c No boot device
1741 43 common/cmd_ide.c boot device found
1742 -44 common/cmd_ide.c Device not available
1743 44 common/cmd_ide.c Device available
1744 -45 common/cmd_ide.c wrong partition selected
1745 45 common/cmd_ide.c partition selected
1746 -46 common/cmd_ide.c Unknown partition table
1747 46 common/cmd_ide.c valid partition table found
1748 -47 common/cmd_ide.c Invalid partition type
1749 47 common/cmd_ide.c correct partition type
1750 -48 common/cmd_ide.c Error reading Image Header on boot device
1751 48 common/cmd_ide.c reading Image Header from IDE device OK
1752 -49 common/cmd_ide.c Image header has bad magic number
1753 49 common/cmd_ide.c Image header has correct magic number
1754 -50 common/cmd_ide.c Image header has bad checksum
1755 50 common/cmd_ide.c Image header has correct checksum
1756 -51 common/cmd_ide.c Error reading Image from IDE device
1757 51 common/cmd_ide.c reading Image from IDE device OK
1758 52 common/cmd_nand.c before loading a Image from a NAND device
1759 -53 common/cmd_nand.c Bad usage of "nand" command
1760 53 common/cmd_nand.c correct usage of "nand" command
1761 -54 common/cmd_nand.c No boot device
1762 54 common/cmd_nand.c boot device found
1763 -55 common/cmd_nand.c Unknown Chip ID on boot device
1764 55 common/cmd_nand.c correct chip ID found, device available
1765 -56 common/cmd_nand.c Error reading Image Header on boot device
1766 56 common/cmd_nand.c reading Image Header from NAND device OK
1767 -57 common/cmd_nand.c Image header has bad magic number
1768 57 common/cmd_nand.c Image header has correct magic number
1769 -58 common/cmd_nand.c Error reading Image from NAND device
1770 58 common/cmd_nand.c reading Image from NAND device OK
1772 -60 common/env_common.c Environment has a bad CRC, using default
1774 64 net/eth.c starting with Ethernetconfiguration.
1775 -64 net/eth.c no Ethernet found.
1776 65 net/eth.c Ethernet found.
1778 -80 common/cmd_net.c usage wrong
1779 80 common/cmd_net.c before calling NetLoop()
1780 -81 common/cmd_net.c some error in NetLoop() occured
1781 81 common/cmd_net.c NetLoop() back without error
1782 -82 common/cmd_net.c size == 0 (File with size 0 loaded)
1783 82 common/cmd_net.c trying automatic boot
1784 83 common/cmd_net.c running autoscript
1785 -83 common/cmd_net.c some error in automatic boot or autoscript
1786 84 common/cmd_net.c end without errors
1791 100 common/cmd_bootm.c Kernel FIT Image has correct format
1792 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format
1793 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration
1794 -101 common/cmd_bootm.c Can't get configuration for kernel subimage
1795 102 common/cmd_bootm.c Kernel unit name specified
1796 -103 common/cmd_bootm.c Can't get kernel subimage node offset
1797 103 common/cmd_bootm.c Found configuration node
1798 104 common/cmd_bootm.c Got kernel subimage node offset
1799 -104 common/cmd_bootm.c Kernel subimage hash verification failed
1800 105 common/cmd_bootm.c Kernel subimage hash verification OK
1801 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture
1802 106 common/cmd_bootm.c Architecture check OK
1803 -106 common/cmd_bootm.c Kernel subimage has wrong typea
1804 107 common/cmd_bootm.c Kernel subimge type OK
1805 -107 common/cmd_bootm.c Can't get kernel subimage data/size
1806 108 common/cmd_bootm.c Got kernel subimage data/size
1807 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT)
1808 -109 common/cmd_bootm.c Can't get kernel subimage type
1809 -110 common/cmd_bootm.c Can't get kernel subimage comp
1810 -111 common/cmd_bootm.c Can't get kernel subimage os
1811 -112 common/cmd_bootm.c Can't get kernel subimage load address
1812 -113 common/cmd_bootm.c Image uncompress/copy overwrite error
1814 120 common/image.c Start initial ramdisk verification
1815 -120 common/image.c Ramdisk FIT image has incorrect format
1816 121 common/image.c Ramdisk FIT image has correct format
1817 122 common/image.c No Ramdisk subimage unit name, using configuration
1818 -122 common/image.c Can't get configuration for ramdisk subimage
1819 123 common/image.c Ramdisk unit name specified
1820 -124 common/image.c Can't get ramdisk subimage node offset
1821 125 common/image.c Got ramdisk subimage node offset
1822 -125 common/image.c Ramdisk subimage hash verification failed
1823 126 common/image.c Ramdisk subimage hash verification OK
1824 -126 common/image.c Ramdisk subimage for unsupported architecture
1825 127 common/image.c Architecture check OK
1826 -127 common/image.c Can't get ramdisk subimage data/size
1827 128 common/image.c Got ramdisk subimage data/size
1828 129 common/image.c Can't get ramdisk load address
1829 -129 common/image.c Got ramdisk load address
1831 -130 common/cmd_doc.c Icorrect FIT image format
1832 131 common/cmd_doc.c FIT image format OK
1834 -140 common/cmd_ide.c Icorrect FIT image format
1835 141 common/cmd_ide.c FIT image format OK
1837 -150 common/cmd_nand.c Icorrect FIT image format
1838 151 common/cmd_nand.c FIT image format OK
1844 [so far only for SMDK2400 and TRAB boards]
1846 - Modem support endable:
1847 CONFIG_MODEM_SUPPORT
1849 - RTS/CTS Flow control enable:
1852 - Modem debug support:
1853 CONFIG_MODEM_SUPPORT_DEBUG
1855 Enables debugging stuff (char screen[1024], dbg())
1856 for modem support. Useful only with BDI2000.
1858 - Interrupt support (PPC):
1860 There are common interrupt_init() and timer_interrupt()
1861 for all PPC archs. interrupt_init() calls interrupt_init_cpu()
1862 for cpu specific initialization. interrupt_init_cpu()
1863 should set decrementer_count to appropriate value. If
1864 cpu resets decrementer automatically after interrupt
1865 (ppc4xx) it should set decrementer_count to zero.
1866 timer_interrupt() calls timer_interrupt_cpu() for cpu
1867 specific handling. If board has watchdog / status_led
1868 / other_activity_monitor it works automatically from
1869 general timer_interrupt().
1873 In the target system modem support is enabled when a
1874 specific key (key combination) is pressed during
1875 power-on. Otherwise U-Boot will boot normally
1876 (autoboot). The key_pressed() fuction is called from
1877 board_init(). Currently key_pressed() is a dummy
1878 function, returning 1 and thus enabling modem
1881 If there are no modem init strings in the
1882 environment, U-Boot proceed to autoboot; the
1883 previous output (banner, info printfs) will be
1886 See also: doc/README.Modem
1889 Configuration Settings:
1890 -----------------------
1892 - CFG_LONGHELP: Defined when you want long help messages included;
1893 undefine this when you're short of memory.
1895 - CFG_PROMPT: This is what U-Boot prints on the console to
1896 prompt for user input.
1898 - CFG_CBSIZE: Buffer size for input from the Console
1900 - CFG_PBSIZE: Buffer size for Console output
1902 - CFG_MAXARGS: max. Number of arguments accepted for monitor commands
1904 - CFG_BARGSIZE: Buffer size for Boot Arguments which are passed to
1905 the application (usually a Linux kernel) when it is
1908 - CFG_BAUDRATE_TABLE:
1909 List of legal baudrate settings for this board.
1911 - CFG_CONSOLE_INFO_QUIET
1912 Suppress display of console information at boot.
1914 - CFG_CONSOLE_IS_IN_ENV
1915 If the board specific function
1916 extern int overwrite_console (void);
1917 returns 1, the stdin, stderr and stdout are switched to the
1918 serial port, else the settings in the environment are used.
1920 - CFG_CONSOLE_OVERWRITE_ROUTINE
1921 Enable the call to overwrite_console().
1923 - CFG_CONSOLE_ENV_OVERWRITE
1924 Enable overwrite of previous console environment settings.
1926 - CFG_MEMTEST_START, CFG_MEMTEST_END:
1927 Begin and End addresses of the area used by the
1931 Enable an alternate, more extensive memory test.
1933 - CFG_MEMTEST_SCRATCH:
1934 Scratch address used by the alternate memory test
1935 You only need to set this if address zero isn't writeable
1937 - CFG_MEM_TOP_HIDE (PPC only):
1938 If CFG_MEM_TOP_HIDE is defined in the board config header,
1939 this specified memory area will get subtracted from the top
1940 (end) of ram and won't get "touched" at all by U-Boot. By
1941 fixing up gd->ram_size the Linux kernel should gets passed
1942 the now "corrected" memory size and won't touch it either.
1943 This should work for arch/ppc and arch/powerpc. Only Linux
1944 board ports in arch/powerpc with bootwrapper support that
1945 recalculate the memory size from the SDRAM controller setup
1946 will have to get fixed in Linux additionally.
1948 This option can be used as a workaround for the 440EPx/GRx
1949 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't
1952 WARNING: Please make sure that this value is a multiple of
1953 the Linux page size (normally 4k). If this is not the case,
1954 then the end address of the Linux memory will be located at a
1955 non page size aligned address and this could cause major
1958 - CFG_TFTP_LOADADDR:
1959 Default load address for network file downloads
1961 - CFG_LOADS_BAUD_CHANGE:
1962 Enable temporary baudrate change while serial download
1965 Physical start address of SDRAM. _Must_ be 0 here.
1968 Physical start address of Motherboard I/O (if using a
1972 Physical start address of Flash memory.
1975 Physical start address of boot monitor code (set by
1976 make config files to be same as the text base address
1977 (TEXT_BASE) used when linking) - same as
1978 CFG_FLASH_BASE when booting from flash.
1981 Size of memory reserved for monitor code, used to
1982 determine _at_compile_time_ (!) if the environment is
1983 embedded within the U-Boot image, or in a separate
1987 Size of DRAM reserved for malloc() use.
1990 Normally compressed uImages are limited to an
1991 uncompressed size of 8 MBytes. If this is not enough,
1992 you can define CFG_BOOTM_LEN in your board config file
1993 to adjust this setting to your needs.
1996 Maximum size of memory mapped by the startup code of
1997 the Linux kernel; all data that must be processed by
1998 the Linux kernel (bd_info, boot arguments, eventually
1999 initrd image) must be put below this limit.
2001 - CFG_MAX_FLASH_BANKS:
2002 Max number of Flash memory banks
2004 - CFG_MAX_FLASH_SECT:
2005 Max number of sectors on a Flash chip
2007 - CFG_FLASH_ERASE_TOUT:
2008 Timeout for Flash erase operations (in ms)
2010 - CFG_FLASH_WRITE_TOUT:
2011 Timeout for Flash write operations (in ms)
2013 - CFG_FLASH_LOCK_TOUT
2014 Timeout for Flash set sector lock bit operation (in ms)
2016 - CFG_FLASH_UNLOCK_TOUT
2017 Timeout for Flash clear lock bits operation (in ms)
2019 - CFG_FLASH_PROTECTION
2020 If defined, hardware flash sectors protection is used
2021 instead of U-Boot software protection.
2023 - CFG_DIRECT_FLASH_TFTP:
2025 Enable TFTP transfers directly to flash memory;
2026 without this option such a download has to be
2027 performed in two steps: (1) download to RAM, and (2)
2028 copy from RAM to flash.
2030 The two-step approach is usually more reliable, since
2031 you can check if the download worked before you erase
2032 the flash, but in some situations (when sytem RAM is
2033 too limited to allow for a tempory copy of the
2034 downloaded image) this option may be very useful.
2037 Define if the flash driver uses extra elements in the
2038 common flash structure for storing flash geometry.
2040 - CFG_FLASH_CFI_DRIVER
2041 This option also enables the building of the cfi_flash driver
2042 in the drivers directory
2044 - CFG_FLASH_QUIET_TEST
2045 If this option is defined, the common CFI flash doesn't
2046 print it's warning upon not recognized FLASH banks. This
2047 is useful, if some of the configured banks are only
2048 optionally available.
2050 - CONFIG_FLASH_SHOW_PROGRESS
2051 If defined (must be an integer), print out countdown
2052 digits and dots. Recommended value: 45 (9..1) for 80
2053 column displays, 15 (3..1) for 40 column displays.
2055 - CFG_RX_ETH_BUFFER:
2056 Defines the number of ethernet receive buffers. On some
2057 ethernet controllers it is recommended to set this value
2058 to 8 or even higher (EEPRO100 or 405 EMAC), since all
2059 buffers can be full shortly after enabling the interface
2060 on high ethernet traffic.
2061 Defaults to 4 if not defined.
2063 The following definitions that deal with the placement and management
2064 of environment data (variable area); in general, we support the
2065 following configurations:
2067 - CFG_ENV_IS_IN_FLASH:
2069 Define this if the environment is in flash memory.
2071 a) The environment occupies one whole flash sector, which is
2072 "embedded" in the text segment with the U-Boot code. This
2073 happens usually with "bottom boot sector" or "top boot
2074 sector" type flash chips, which have several smaller
2075 sectors at the start or the end. For instance, such a
2076 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In
2077 such a case you would place the environment in one of the
2078 4 kB sectors - with U-Boot code before and after it. With
2079 "top boot sector" type flash chips, you would put the
2080 environment in one of the last sectors, leaving a gap
2081 between U-Boot and the environment.
2085 Offset of environment data (variable area) to the
2086 beginning of flash memory; for instance, with bottom boot
2087 type flash chips the second sector can be used: the offset
2088 for this sector is given here.
2090 CFG_ENV_OFFSET is used relative to CFG_FLASH_BASE.
2094 This is just another way to specify the start address of
2095 the flash sector containing the environment (instead of
2098 - CFG_ENV_SECT_SIZE:
2100 Size of the sector containing the environment.
2103 b) Sometimes flash chips have few, equal sized, BIG sectors.
2104 In such a case you don't want to spend a whole sector for
2109 If you use this in combination with CFG_ENV_IS_IN_FLASH
2110 and CFG_ENV_SECT_SIZE, you can specify to use only a part
2111 of this flash sector for the environment. This saves
2112 memory for the RAM copy of the environment.
2114 It may also save flash memory if you decide to use this
2115 when your environment is "embedded" within U-Boot code,
2116 since then the remainder of the flash sector could be used
2117 for U-Boot code. It should be pointed out that this is
2118 STRONGLY DISCOURAGED from a robustness point of view:
2119 updating the environment in flash makes it always
2120 necessary to erase the WHOLE sector. If something goes
2121 wrong before the contents has been restored from a copy in
2122 RAM, your target system will be dead.
2124 - CFG_ENV_ADDR_REDUND
2127 These settings describe a second storage area used to hold
2128 a redundand copy of the environment data, so that there is
2129 a valid backup copy in case there is a power failure during
2130 a "saveenv" operation.
2132 BE CAREFUL! Any changes to the flash layout, and some changes to the
2133 source code will make it necessary to adapt <board>/u-boot.lds*
2137 - CFG_ENV_IS_IN_NVRAM:
2139 Define this if you have some non-volatile memory device
2140 (NVRAM, battery buffered SRAM) which you want to use for the
2146 These two #defines are used to determin the memory area you
2147 want to use for environment. It is assumed that this memory
2148 can just be read and written to, without any special
2151 BE CAREFUL! The first access to the environment happens quite early
2152 in U-Boot initalization (when we try to get the setting of for the
2153 console baudrate). You *MUST* have mappend your NVRAM area then, or
2156 Please note that even with NVRAM we still use a copy of the
2157 environment in RAM: we could work on NVRAM directly, but we want to
2158 keep settings there always unmodified except somebody uses "saveenv"
2159 to save the current settings.
2162 - CFG_ENV_IS_IN_EEPROM:
2164 Use this if you have an EEPROM or similar serial access
2165 device and a driver for it.
2170 These two #defines specify the offset and size of the
2171 environment area within the total memory of your EEPROM.
2173 - CFG_I2C_EEPROM_ADDR:
2174 If defined, specified the chip address of the EEPROM device.
2175 The default address is zero.
2177 - CFG_EEPROM_PAGE_WRITE_BITS:
2178 If defined, the number of bits used to address bytes in a
2179 single page in the EEPROM device. A 64 byte page, for example
2180 would require six bits.
2182 - CFG_EEPROM_PAGE_WRITE_DELAY_MS:
2183 If defined, the number of milliseconds to delay between
2184 page writes. The default is zero milliseconds.
2186 - CFG_I2C_EEPROM_ADDR_LEN:
2187 The length in bytes of the EEPROM memory array address. Note
2188 that this is NOT the chip address length!
2190 - CFG_I2C_EEPROM_ADDR_OVERFLOW:
2191 EEPROM chips that implement "address overflow" are ones
2192 like Catalyst 24WC04/08/16 which has 9/10/11 bits of
2193 address and the extra bits end up in the "chip address" bit
2194 slots. This makes a 24WC08 (1Kbyte) chip look like four 256
2197 Note that we consider the length of the address field to
2198 still be one byte because the extra address bits are hidden
2199 in the chip address.
2202 The size in bytes of the EEPROM device.
2205 - CFG_ENV_IS_IN_DATAFLASH:
2207 Define this if you have a DataFlash memory device which you
2208 want to use for the environment.
2214 These three #defines specify the offset and size of the
2215 environment area within the total memory of your DataFlash placed
2216 at the specified address.
2218 - CFG_ENV_IS_IN_NAND:
2220 Define this if you have a NAND device which you want to use
2221 for the environment.
2226 These two #defines specify the offset and size of the environment
2227 area within the first NAND device.
2229 - CFG_ENV_OFFSET_REDUND
2231 This setting describes a second storage area of CFG_ENV_SIZE
2232 size used to hold a redundant copy of the environment data,
2233 so that there is a valid backup copy in case there is a
2234 power failure during a "saveenv" operation.
2236 Note: CFG_ENV_OFFSET and CFG_ENV_OFFSET_REDUND must be aligned
2237 to a block boundary, and CFG_ENV_SIZE must be a multiple of
2238 the NAND devices block size.
2240 - CFG_SPI_INIT_OFFSET
2242 Defines offset to the initial SPI buffer area in DPRAM. The
2243 area is used at an early stage (ROM part) if the environment
2244 is configured to reside in the SPI EEPROM: We need a 520 byte
2245 scratch DPRAM area. It is used between the two initialization
2246 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems
2247 to be a good choice since it makes it far enough from the
2248 start of the data area as well as from the stack pointer.
2250 Please note that the environment is read-only until the monitor
2251 has been relocated to RAM and a RAM copy of the environment has been
2252 created; also, when using EEPROM you will have to use getenv_r()
2253 until then to read environment variables.
2255 The environment is protected by a CRC32 checksum. Before the monitor
2256 is relocated into RAM, as a result of a bad CRC you will be working
2257 with the compiled-in default environment - *silently*!!! [This is
2258 necessary, because the first environment variable we need is the
2259 "baudrate" setting for the console - if we have a bad CRC, we don't
2260 have any device yet where we could complain.]
2262 Note: once the monitor has been relocated, then it will complain if
2263 the default environment is used; a new CRC is computed as soon as you
2264 use the "saveenv" command to store a valid environment.
2266 - CFG_FAULT_ECHO_LINK_DOWN:
2267 Echo the inverted Ethernet link state to the fault LED.
2269 Note: If this option is active, then CFG_FAULT_MII_ADDR
2270 also needs to be defined.
2272 - CFG_FAULT_MII_ADDR:
2273 MII address of the PHY to check for the Ethernet link state.
2275 - CFG_64BIT_VSPRINTF:
2276 Makes vsprintf (and all *printf functions) support printing
2277 of 64bit values by using the L quantifier
2279 - CFG_64BIT_STRTOUL:
2280 Adds simple_strtoull that returns a 64bit value
2282 Low Level (hardware related) configuration options:
2283 ---------------------------------------------------
2285 - CFG_CACHELINE_SIZE:
2286 Cache Line Size of the CPU.
2289 Default address of the IMMR after system reset.
2291 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU,
2292 and RPXsuper) to be able to adjust the position of
2293 the IMMR register after a reset.
2295 - Floppy Disk Support:
2296 CFG_FDC_DRIVE_NUMBER
2298 the default drive number (default value 0)
2302 defines the spacing between fdc chipset registers
2307 defines the offset of register from address. It
2308 depends on which part of the data bus is connected to
2309 the fdc chipset. (default value 0)
2311 If CFG_ISA_IO_STRIDE CFG_ISA_IO_OFFSET and
2312 CFG_FDC_DRIVE_NUMBER are undefined, they take their
2315 if CFG_FDC_HW_INIT is defined, then the function
2316 fdc_hw_init() is called at the beginning of the FDC
2317 setup. fdc_hw_init() must be provided by the board
2318 source code. It is used to make hardware dependant
2321 - CFG_IMMR: Physical address of the Internal Memory.
2322 DO NOT CHANGE unless you know exactly what you're
2323 doing! (11-4) [MPC8xx/82xx systems only]
2325 - CFG_INIT_RAM_ADDR:
2327 Start address of memory area that can be used for
2328 initial data and stack; please note that this must be
2329 writable memory that is working WITHOUT special
2330 initialization, i. e. you CANNOT use normal RAM which
2331 will become available only after programming the
2332 memory controller and running certain initialization
2335 U-Boot uses the following memory types:
2336 - MPC8xx and MPC8260: IMMR (internal memory of the CPU)
2337 - MPC824X: data cache
2338 - PPC4xx: data cache
2340 - CFG_GBL_DATA_OFFSET:
2342 Offset of the initial data structure in the memory
2343 area defined by CFG_INIT_RAM_ADDR. Usually
2344 CFG_GBL_DATA_OFFSET is chosen such that the initial
2345 data is located at the end of the available space
2346 (sometimes written as (CFG_INIT_RAM_END -
2347 CFG_INIT_DATA_SIZE), and the initial stack is just
2348 below that area (growing from (CFG_INIT_RAM_ADDR +
2349 CFG_GBL_DATA_OFFSET) downward.
2352 On the MPC824X (or other systems that use the data
2353 cache for initial memory) the address chosen for
2354 CFG_INIT_RAM_ADDR is basically arbitrary - it must
2355 point to an otherwise UNUSED address space between
2356 the top of RAM and the start of the PCI space.
2358 - CFG_SIUMCR: SIU Module Configuration (11-6)
2360 - CFG_SYPCR: System Protection Control (11-9)
2362 - CFG_TBSCR: Time Base Status and Control (11-26)
2364 - CFG_PISCR: Periodic Interrupt Status and Control (11-31)
2366 - CFG_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30)
2368 - CFG_SCCR: System Clock and reset Control Register (15-27)
2370 - CFG_OR_TIMING_SDRAM:
2374 periodic timer for refresh
2376 - CFG_DER: Debug Event Register (37-47)
2378 - FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CFG_REMAP_OR_AM,
2379 CFG_PRELIM_OR_AM, CFG_OR_TIMING_FLASH, CFG_OR0_REMAP,
2380 CFG_OR0_PRELIM, CFG_BR0_PRELIM, CFG_OR1_REMAP, CFG_OR1_PRELIM,
2382 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
2384 - SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
2385 CFG_OR_TIMING_SDRAM, CFG_OR2_PRELIM, CFG_BR2_PRELIM,
2386 CFG_OR3_PRELIM, CFG_BR3_PRELIM:
2387 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
2389 - CFG_MAMR_PTA, CFG_MPTPR_2BK_4K, CFG_MPTPR_1BK_4K, CFG_MPTPR_2BK_8K,
2390 CFG_MPTPR_1BK_8K, CFG_MAMR_8COL, CFG_MAMR_9COL:
2391 Machine Mode Register and Memory Periodic Timer
2392 Prescaler definitions (SDRAM timing)
2394 - CFG_I2C_UCODE_PATCH, CFG_I2C_DPMEM_OFFSET [0x1FC0]:
2395 enable I2C microcode relocation patch (MPC8xx);
2396 define relocation offset in DPRAM [DSP2]
2398 - CFG_SMC_UCODE_PATCH, CFG_SMC_DPMEM_OFFSET [0x1FC0]:
2399 enable SMC microcode relocation patch (MPC8xx);
2400 define relocation offset in DPRAM [SMC1]
2402 - CFG_SPI_UCODE_PATCH, CFG_SPI_DPMEM_OFFSET [0x1FC0]:
2403 enable SPI microcode relocation patch (MPC8xx);
2404 define relocation offset in DPRAM [SCC4]
2407 Use OSCM clock mode on MBX8xx board. Be careful,
2408 wrong setting might damage your board. Read
2409 doc/README.MBX before setting this variable!
2411 - CFG_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only)
2412 Offset of the bootmode word in DPRAM used by post
2413 (Power On Self Tests). This definition overrides
2414 #define'd default value in commproc.h resp.
2417 - CFG_PCI_SLV_MEM_LOCAL, CFG_PCI_SLV_MEM_BUS, CFG_PICMR0_MASK_ATTRIB,
2418 CFG_PCI_MSTR0_LOCAL, CFG_PCIMSK0_MASK, CFG_PCI_MSTR1_LOCAL,
2419 CFG_PCIMSK1_MASK, CFG_PCI_MSTR_MEM_LOCAL, CFG_PCI_MSTR_MEM_BUS,
2420 CFG_CPU_PCI_MEM_START, CFG_PCI_MSTR_MEM_SIZE, CFG_POCMR0_MASK_ATTRIB,
2421 CFG_PCI_MSTR_MEMIO_LOCAL, CFG_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START,
2422 CFG_PCI_MSTR_MEMIO_SIZE, CFG_POCMR1_MASK_ATTRIB, CFG_PCI_MSTR_IO_LOCAL,
2423 CFG_PCI_MSTR_IO_BUS, CFG_CPU_PCI_IO_START, CFG_PCI_MSTR_IO_SIZE,
2424 CFG_POCMR2_MASK_ATTRIB: (MPC826x only)
2425 Overrides the default PCI memory map in cpu/mpc8260/pci.c if set.
2428 Get DDR timing information from an I2C EEPROM. Common
2429 with pluggable memory modules such as SODIMMs
2432 I2C address of the SPD EEPROM
2435 If SPD EEPROM is on an I2C bus other than the first
2436 one, specify here. Note that the value must resolve
2437 to something your driver can deal with.
2439 - CFG_83XX_DDR_USES_CS0
2440 Only for 83xx systems. If specified, then DDR should
2441 be configured using CS0 and CS1 instead of CS2 and CS3.
2443 - CFG_83XX_DDR_USES_CS0
2444 Only for 83xx systems. If specified, then DDR should
2445 be configured using CS0 and CS1 instead of CS2 and CS3.
2447 - CONFIG_ETHER_ON_FEC[12]
2448 Define to enable FEC[12] on a 8xx series processor.
2450 - CONFIG_FEC[12]_PHY
2451 Define to the hardcoded PHY address which corresponds
2452 to the given FEC; i. e.
2453 #define CONFIG_FEC1_PHY 4
2454 means that the PHY with address 4 is connected to FEC1
2456 When set to -1, means to probe for first available.
2458 - CONFIG_FEC[12]_PHY_NORXERR
2459 The PHY does not have a RXERR line (RMII only).
2460 (so program the FEC to ignore it).
2463 Enable RMII mode for all FECs.
2464 Note that this is a global option, we can't
2465 have one FEC in standard MII mode and another in RMII mode.
2467 - CONFIG_CRC32_VERIFY
2468 Add a verify option to the crc32 command.
2471 => crc32 -v <address> <count> <crc32>
2473 Where address/count indicate a memory area
2474 and crc32 is the correct crc32 which the
2478 Add the "loopw" memory command. This only takes effect if
2479 the memory commands are activated globally (CONFIG_CMD_MEM).
2482 Add the "mdc" and "mwc" memory commands. These are cyclic
2487 This command will print 4 bytes (10,11,12,13) each 500 ms.
2489 => mwc.l 100 12345678 10
2490 This command will write 12345678 to address 100 all 10 ms.
2492 This only takes effect if the memory commands are activated
2493 globally (CONFIG_CMD_MEM).
2495 - CONFIG_SKIP_LOWLEVEL_INIT
2496 - CONFIG_SKIP_RELOCATE_UBOOT
2498 [ARM only] If these variables are defined, then
2499 certain low level initializations (like setting up
2500 the memory controller) are omitted and/or U-Boot does
2501 not relocate itself into RAM.
2502 Normally these variables MUST NOT be defined. The
2503 only exception is when U-Boot is loaded (to RAM) by
2504 some other boot loader or by a debugger which
2505 performs these intializations itself.
2508 Building the Software:
2509 ======================
2511 Building U-Boot has been tested in several native build environments
2512 and in many different cross environments. Of course we cannot support
2513 all possibly existing versions of cross development tools in all
2514 (potentially obsolete) versions. In case of tool chain problems we
2515 recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK)
2516 which is extensively used to build and test U-Boot.
2518 If you are not using a native environment, it is assumed that you
2519 have GNU cross compiling tools available in your path. In this case,
2520 you must set the environment variable CROSS_COMPILE in your shell.
2521 Note that no changes to the Makefile or any other source files are
2522 necessary. For example using the ELDK on a 4xx CPU, please enter:
2524 $ CROSS_COMPILE=ppc_4xx-
2525 $ export CROSS_COMPILE
2527 U-Boot is intended to be simple to build. After installing the
2528 sources you must configure U-Boot for one specific board type. This
2533 where "NAME_config" is the name of one of the existing configu-
2534 rations; see the main Makefile for supported names.
2536 Note: for some board special configuration names may exist; check if
2537 additional information is available from the board vendor; for
2538 instance, the TQM823L systems are available without (standard)
2539 or with LCD support. You can select such additional "features"
2540 when chosing the configuration, i. e.
2543 - will configure for a plain TQM823L, i. e. no LCD support
2545 make TQM823L_LCD_config
2546 - will configure for a TQM823L with U-Boot console on LCD
2551 Finally, type "make all", and you should get some working U-Boot
2552 images ready for download to / installation on your system:
2554 - "u-boot.bin" is a raw binary image
2555 - "u-boot" is an image in ELF binary format
2556 - "u-boot.srec" is in Motorola S-Record format
2558 By default the build is performed locally and the objects are saved
2559 in the source directory. One of the two methods can be used to change
2560 this behavior and build U-Boot to some external directory:
2562 1. Add O= to the make command line invocations:
2564 make O=/tmp/build distclean
2565 make O=/tmp/build NAME_config
2566 make O=/tmp/build all
2568 2. Set environment variable BUILD_DIR to point to the desired location:
2570 export BUILD_DIR=/tmp/build
2575 Note that the command line "O=" setting overrides the BUILD_DIR environment
2579 Please be aware that the Makefiles assume you are using GNU make, so
2580 for instance on NetBSD you might need to use "gmake" instead of
2584 If the system board that you have is not listed, then you will need
2585 to port U-Boot to your hardware platform. To do this, follow these
2588 1. Add a new configuration option for your board to the toplevel
2589 "Makefile" and to the "MAKEALL" script, using the existing
2590 entries as examples. Note that here and at many other places
2591 boards and other names are listed in alphabetical sort order. Please
2593 2. Create a new directory to hold your board specific code. Add any
2594 files you need. In your board directory, you will need at least
2595 the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds".
2596 3. Create a new configuration file "include/configs/<board>.h" for
2598 3. If you're porting U-Boot to a new CPU, then also create a new
2599 directory to hold your CPU specific code. Add any files you need.
2600 4. Run "make <board>_config" with your new name.
2601 5. Type "make", and you should get a working "u-boot.srec" file
2602 to be installed on your target system.
2603 6. Debug and solve any problems that might arise.
2604 [Of course, this last step is much harder than it sounds.]
2607 Testing of U-Boot Modifications, Ports to New Hardware, etc.:
2608 ==============================================================
2610 If you have modified U-Boot sources (for instance added a new board
2611 or support for new devices, a new CPU, etc.) you are expected to
2612 provide feedback to the other developers. The feedback normally takes
2613 the form of a "patch", i. e. a context diff against a certain (latest
2614 official or latest in the git repository) version of U-Boot sources.
2616 But before you submit such a patch, please verify that your modifi-
2617 cation did not break existing code. At least make sure that *ALL* of
2618 the supported boards compile WITHOUT ANY compiler warnings. To do so,
2619 just run the "MAKEALL" script, which will configure and build U-Boot
2620 for ALL supported system. Be warned, this will take a while. You can
2621 select which (cross) compiler to use by passing a `CROSS_COMPILE'
2622 environment variable to the script, i. e. to use the ELDK cross tools
2625 CROSS_COMPILE=ppc_8xx- MAKEALL
2627 or to build on a native PowerPC system you can type
2629 CROSS_COMPILE=' ' MAKEALL
2631 When using the MAKEALL script, the default behaviour is to build
2632 U-Boot in the source directory. This location can be changed by
2633 setting the BUILD_DIR environment variable. Also, for each target
2634 built, the MAKEALL script saves two log files (<target>.ERR and
2635 <target>.MAKEALL) in the <source dir>/LOG directory. This default
2636 location can be changed by setting the MAKEALL_LOGDIR environment
2637 variable. For example:
2639 export BUILD_DIR=/tmp/build
2640 export MAKEALL_LOGDIR=/tmp/log
2641 CROSS_COMPILE=ppc_8xx- MAKEALL
2643 With the above settings build objects are saved in the /tmp/build,
2644 log files are saved in the /tmp/log and the source tree remains clean
2645 during the whole build process.
2648 See also "U-Boot Porting Guide" below.
2651 Monitor Commands - Overview:
2652 ============================
2654 go - start application at address 'addr'
2655 run - run commands in an environment variable
2656 bootm - boot application image from memory
2657 bootp - boot image via network using BootP/TFTP protocol
2658 tftpboot- boot image via network using TFTP protocol
2659 and env variables "ipaddr" and "serverip"
2660 (and eventually "gatewayip")
2661 rarpboot- boot image via network using RARP/TFTP protocol
2662 diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
2663 loads - load S-Record file over serial line
2664 loadb - load binary file over serial line (kermit mode)
2666 mm - memory modify (auto-incrementing)
2667 nm - memory modify (constant address)
2668 mw - memory write (fill)
2670 cmp - memory compare
2671 crc32 - checksum calculation
2672 imd - i2c memory display
2673 imm - i2c memory modify (auto-incrementing)
2674 inm - i2c memory modify (constant address)
2675 imw - i2c memory write (fill)
2676 icrc32 - i2c checksum calculation
2677 iprobe - probe to discover valid I2C chip addresses
2678 iloop - infinite loop on address range
2679 isdram - print SDRAM configuration information
2680 sspi - SPI utility commands
2681 base - print or set address offset
2682 printenv- print environment variables
2683 setenv - set environment variables
2684 saveenv - save environment variables to persistent storage
2685 protect - enable or disable FLASH write protection
2686 erase - erase FLASH memory
2687 flinfo - print FLASH memory information
2688 bdinfo - print Board Info structure
2689 iminfo - print header information for application image
2690 coninfo - print console devices and informations
2691 ide - IDE sub-system
2692 loop - infinite loop on address range
2693 loopw - infinite write loop on address range
2694 mtest - simple RAM test
2695 icache - enable or disable instruction cache
2696 dcache - enable or disable data cache
2697 reset - Perform RESET of the CPU
2698 echo - echo args to console
2699 version - print monitor version
2700 help - print online help
2701 ? - alias for 'help'
2704 Monitor Commands - Detailed Description:
2705 ========================================
2709 For now: just type "help <command>".
2712 Environment Variables:
2713 ======================
2715 U-Boot supports user configuration using Environment Variables which
2716 can be made persistent by saving to Flash memory.
2718 Environment Variables are set using "setenv", printed using
2719 "printenv", and saved to Flash using "saveenv". Using "setenv"
2720 without a value can be used to delete a variable from the
2721 environment. As long as you don't save the environment you are
2722 working with an in-memory copy. In case the Flash area containing the
2723 environment is erased by accident, a default environment is provided.
2725 Some configuration options can be set using Environment Variables:
2727 baudrate - see CONFIG_BAUDRATE
2729 bootdelay - see CONFIG_BOOTDELAY
2731 bootcmd - see CONFIG_BOOTCOMMAND
2733 bootargs - Boot arguments when booting an RTOS image
2735 bootfile - Name of the image to load with TFTP
2737 autoload - if set to "no" (any string beginning with 'n'),
2738 "bootp" will just load perform a lookup of the
2739 configuration from the BOOTP server, but not try to
2740 load any image using TFTP
2742 autoscript - if set to "yes" commands like "loadb", "loady",
2743 "bootp", "tftpb", "rarpboot" and "nfs" will attempt
2744 to automatically run script images (by internally
2745 calling "autoscript").
2747 autoscript_uname - if script image is in a format (FIT) this
2748 variable is used to get script subimage unit name.
2750 autostart - if set to "yes", an image loaded using the "bootp",
2751 "rarpboot", "tftpboot" or "diskboot" commands will
2752 be automatically started (by internally calling
2755 If set to "no", a standalone image passed to the
2756 "bootm" command will be copied to the load address
2757 (and eventually uncompressed), but NOT be started.
2758 This can be used to load and uncompress arbitrary
2761 i2cfast - (PPC405GP|PPC405EP only)
2762 if set to 'y' configures Linux I2C driver for fast
2763 mode (400kHZ). This environment variable is used in
2764 initialization code. So, for changes to be effective
2765 it must be saved and board must be reset.
2767 initrd_high - restrict positioning of initrd images:
2768 If this variable is not set, initrd images will be
2769 copied to the highest possible address in RAM; this
2770 is usually what you want since it allows for
2771 maximum initrd size. If for some reason you want to
2772 make sure that the initrd image is loaded below the
2773 CFG_BOOTMAPSZ limit, you can set this environment
2774 variable to a value of "no" or "off" or "0".
2775 Alternatively, you can set it to a maximum upper
2776 address to use (U-Boot will still check that it
2777 does not overwrite the U-Boot stack and data).
2779 For instance, when you have a system with 16 MB
2780 RAM, and want to reserve 4 MB from use by Linux,
2781 you can do this by adding "mem=12M" to the value of
2782 the "bootargs" variable. However, now you must make
2783 sure that the initrd image is placed in the first
2784 12 MB as well - this can be done with
2786 setenv initrd_high 00c00000
2788 If you set initrd_high to 0xFFFFFFFF, this is an
2789 indication to U-Boot that all addresses are legal
2790 for the Linux kernel, including addresses in flash
2791 memory. In this case U-Boot will NOT COPY the
2792 ramdisk at all. This may be useful to reduce the
2793 boot time on your system, but requires that this
2794 feature is supported by your Linux kernel.
2796 ipaddr - IP address; needed for tftpboot command
2798 loadaddr - Default load address for commands like "bootp",
2799 "rarpboot", "tftpboot", "loadb" or "diskboot"
2801 loads_echo - see CONFIG_LOADS_ECHO
2803 serverip - TFTP server IP address; needed for tftpboot command
2805 bootretry - see CONFIG_BOOT_RETRY_TIME
2807 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
2809 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
2811 ethprime - When CONFIG_NET_MULTI is enabled controls which
2812 interface is used first.
2814 ethact - When CONFIG_NET_MULTI is enabled controls which
2815 interface is currently active. For example you
2816 can do the following
2818 => setenv ethact FEC ETHERNET
2819 => ping 192.168.0.1 # traffic sent on FEC ETHERNET
2820 => setenv ethact SCC ETHERNET
2821 => ping 10.0.0.1 # traffic sent on SCC ETHERNET
2823 ethrotate - When set to "no" U-Boot does not go through all
2824 available network interfaces.
2825 It just stays at the currently selected interface.
2827 netretry - When set to "no" each network operation will
2828 either succeed or fail without retrying.
2829 When set to "once" the network operation will
2830 fail when all the available network interfaces
2831 are tried once without success.
2832 Useful on scripts which control the retry operation
2835 npe_ucode - see CONFIG_IXP4XX_NPE_EXT_UCOD
2836 if set load address for the npe microcode
2838 tftpsrcport - If this is set, the value is used for TFTP's
2841 tftpdstport - If this is set, the value is used for TFTP's UDP
2842 destination port instead of the Well Know Port 69.
2844 vlan - When set to a value < 4095 the traffic over
2845 ethernet is encapsulated/received over 802.1q
2848 The following environment variables may be used and automatically
2849 updated by the network boot commands ("bootp" and "rarpboot"),
2850 depending the information provided by your boot server:
2852 bootfile - see above
2853 dnsip - IP address of your Domain Name Server
2854 dnsip2 - IP address of your secondary Domain Name Server
2855 gatewayip - IP address of the Gateway (Router) to use
2856 hostname - Target hostname
2858 netmask - Subnet Mask
2859 rootpath - Pathname of the root filesystem on the NFS server
2860 serverip - see above
2863 There are two special Environment Variables:
2865 serial# - contains hardware identification information such
2866 as type string and/or serial number
2867 ethaddr - Ethernet address
2869 These variables can be set only once (usually during manufacturing of
2870 the board). U-Boot refuses to delete or overwrite these variables
2871 once they have been set once.
2874 Further special Environment Variables:
2876 ver - Contains the U-Boot version string as printed
2877 with the "version" command. This variable is
2878 readonly (see CONFIG_VERSION_VARIABLE).
2881 Please note that changes to some configuration parameters may take
2882 only effect after the next boot (yes, that's just like Windoze :-).
2885 Command Line Parsing:
2886 =====================
2888 There are two different command line parsers available with U-Boot:
2889 the old "simple" one, and the much more powerful "hush" shell:
2891 Old, simple command line parser:
2892 --------------------------------
2894 - supports environment variables (through setenv / saveenv commands)
2895 - several commands on one line, separated by ';'
2896 - variable substitution using "... ${name} ..." syntax
2897 - special characters ('$', ';') can be escaped by prefixing with '\',
2899 setenv bootcmd bootm \${address}
2900 - You can also escape text by enclosing in single apostrophes, for example:
2901 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
2906 - similar to Bourne shell, with control structures like
2907 if...then...else...fi, for...do...done; while...do...done,
2908 until...do...done, ...
2909 - supports environment ("global") variables (through setenv / saveenv
2910 commands) and local shell variables (through standard shell syntax
2911 "name=value"); only environment variables can be used with "run"
2917 (1) If a command line (or an environment variable executed by a "run"
2918 command) contains several commands separated by semicolon, and
2919 one of these commands fails, then the remaining commands will be
2922 (2) If you execute several variables with one call to run (i. e.
2923 calling run with a list af variables as arguments), any failing
2924 command will cause "run" to terminate, i. e. the remaining
2925 variables are not executed.
2927 Note for Redundant Ethernet Interfaces:
2928 =======================================
2930 Some boards come with redundant ethernet interfaces; U-Boot supports
2931 such configurations and is capable of automatic selection of a
2932 "working" interface when needed. MAC assignment works as follows:
2934 Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
2935 MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
2936 "eth1addr" (=>eth1), "eth2addr", ...
2938 If the network interface stores some valid MAC address (for instance
2939 in SROM), this is used as default address if there is NO correspon-
2940 ding setting in the environment; if the corresponding environment
2941 variable is set, this overrides the settings in the card; that means:
2943 o If the SROM has a valid MAC address, and there is no address in the
2944 environment, the SROM's address is used.
2946 o If there is no valid address in the SROM, and a definition in the
2947 environment exists, then the value from the environment variable is
2950 o If both the SROM and the environment contain a MAC address, and
2951 both addresses are the same, this MAC address is used.
2953 o If both the SROM and the environment contain a MAC address, and the
2954 addresses differ, the value from the environment is used and a
2957 o If neither SROM nor the environment contain a MAC address, an error
2964 U-Boot is capable of booting (and performing other auxiliary operations on)
2965 images in two formats:
2967 New uImage format (FIT)
2968 -----------------------
2970 Flexible and powerful format based on Flattened Image Tree -- FIT (similar
2971 to Flattened Device Tree). It allows the use of images with multiple
2972 components (several kernels, ramdisks, etc.), with contents protected by
2973 SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory.
2979 Old image format is based on binary files which can be basically anything,
2980 preceded by a special header; see the definitions in include/image.h for
2981 details; basically, the header defines the following image properties:
2983 * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
2984 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
2985 LynxOS, pSOS, QNX, RTEMS, ARTOS;
2986 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, ARTOS, LynxOS).
2987 * Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86,
2988 IA64, MIPS, NIOS, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
2989 Currently supported: ARM, AVR32, Intel x86, MIPS, NIOS, PowerPC).
2990 * Compression Type (uncompressed, gzip, bzip2)
2996 The header is marked by a special Magic Number, and both the header
2997 and the data portions of the image are secured against corruption by
3004 Although U-Boot should support any OS or standalone application
3005 easily, the main focus has always been on Linux during the design of
3008 U-Boot includes many features that so far have been part of some
3009 special "boot loader" code within the Linux kernel. Also, any
3010 "initrd" images to be used are no longer part of one big Linux image;
3011 instead, kernel and "initrd" are separate images. This implementation
3012 serves several purposes:
3014 - the same features can be used for other OS or standalone
3015 applications (for instance: using compressed images to reduce the
3016 Flash memory footprint)
3018 - it becomes much easier to port new Linux kernel versions because
3019 lots of low-level, hardware dependent stuff are done by U-Boot
3021 - the same Linux kernel image can now be used with different "initrd"
3022 images; of course this also means that different kernel images can
3023 be run with the same "initrd". This makes testing easier (you don't
3024 have to build a new "zImage.initrd" Linux image when you just
3025 change a file in your "initrd"). Also, a field-upgrade of the
3026 software is easier now.
3032 Porting Linux to U-Boot based systems:
3033 ---------------------------------------
3035 U-Boot cannot save you from doing all the necessary modifications to
3036 configure the Linux device drivers for use with your target hardware
3037 (no, we don't intend to provide a full virtual machine interface to
3040 But now you can ignore ALL boot loader code (in arch/ppc/mbxboot).
3042 Just make sure your machine specific header file (for instance
3043 include/asm-ppc/tqm8xx.h) includes the same definition of the Board
3044 Information structure as we define in include/u-boot.h, and make
3045 sure that your definition of IMAP_ADDR uses the same value as your
3046 U-Boot configuration in CFG_IMMR.
3049 Configuring the Linux kernel:
3050 -----------------------------
3052 No specific requirements for U-Boot. Make sure you have some root
3053 device (initial ramdisk, NFS) for your target system.
3056 Building a Linux Image:
3057 -----------------------
3059 With U-Boot, "normal" build targets like "zImage" or "bzImage" are
3060 not used. If you use recent kernel source, a new build target
3061 "uImage" will exist which automatically builds an image usable by
3062 U-Boot. Most older kernels also have support for a "pImage" target,
3063 which was introduced for our predecessor project PPCBoot and uses a
3064 100% compatible format.
3073 The "uImage" build target uses a special tool (in 'tools/mkimage') to
3074 encapsulate a compressed Linux kernel image with header information,
3075 CRC32 checksum etc. for use with U-Boot. This is what we are doing:
3077 * build a standard "vmlinux" kernel image (in ELF binary format):
3079 * convert the kernel into a raw binary image:
3081 ${CROSS_COMPILE}-objcopy -O binary \
3082 -R .note -R .comment \
3083 -S vmlinux linux.bin
3085 * compress the binary image:
3089 * package compressed binary image for U-Boot:
3091 mkimage -A ppc -O linux -T kernel -C gzip \
3092 -a 0 -e 0 -n "Linux Kernel Image" \
3093 -d linux.bin.gz uImage
3096 The "mkimage" tool can also be used to create ramdisk images for use
3097 with U-Boot, either separated from the Linux kernel image, or
3098 combined into one file. "mkimage" encapsulates the images with a 64
3099 byte header containing information about target architecture,
3100 operating system, image type, compression method, entry points, time
3101 stamp, CRC32 checksums, etc.
3103 "mkimage" can be called in two ways: to verify existing images and
3104 print the header information, or to build new images.
3106 In the first form (with "-l" option) mkimage lists the information
3107 contained in the header of an existing U-Boot image; this includes
3108 checksum verification:
3110 tools/mkimage -l image
3111 -l ==> list image header information
3113 The second form (with "-d" option) is used to build a U-Boot image
3114 from a "data file" which is used as image payload:
3116 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
3117 -n name -d data_file image
3118 -A ==> set architecture to 'arch'
3119 -O ==> set operating system to 'os'
3120 -T ==> set image type to 'type'
3121 -C ==> set compression type 'comp'
3122 -a ==> set load address to 'addr' (hex)
3123 -e ==> set entry point to 'ep' (hex)
3124 -n ==> set image name to 'name'
3125 -d ==> use image data from 'datafile'
3127 Right now, all Linux kernels for PowerPC systems use the same load
3128 address (0x00000000), but the entry point address depends on the
3131 - 2.2.x kernels have the entry point at 0x0000000C,
3132 - 2.3.x and later kernels have the entry point at 0x00000000.
3134 So a typical call to build a U-Boot image would read:
3136 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
3137 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
3138 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux.gz \
3139 > examples/uImage.TQM850L
3140 Image Name: 2.4.4 kernel for TQM850L
3141 Created: Wed Jul 19 02:34:59 2000
3142 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3143 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
3144 Load Address: 0x00000000
3145 Entry Point: 0x00000000
3147 To verify the contents of the image (or check for corruption):
3149 -> tools/mkimage -l examples/uImage.TQM850L
3150 Image Name: 2.4.4 kernel for TQM850L
3151 Created: Wed Jul 19 02:34:59 2000
3152 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3153 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
3154 Load Address: 0x00000000
3155 Entry Point: 0x00000000
3157 NOTE: for embedded systems where boot time is critical you can trade
3158 speed for memory and install an UNCOMPRESSED image instead: this
3159 needs more space in Flash, but boots much faster since it does not
3160 need to be uncompressed:
3162 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux.gz
3163 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
3164 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
3165 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux \
3166 > examples/uImage.TQM850L-uncompressed
3167 Image Name: 2.4.4 kernel for TQM850L
3168 Created: Wed Jul 19 02:34:59 2000
3169 Image Type: PowerPC Linux Kernel Image (uncompressed)
3170 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
3171 Load Address: 0x00000000
3172 Entry Point: 0x00000000
3175 Similar you can build U-Boot images from a 'ramdisk.image.gz' file
3176 when your kernel is intended to use an initial ramdisk:
3178 -> tools/mkimage -n 'Simple Ramdisk Image' \
3179 > -A ppc -O linux -T ramdisk -C gzip \
3180 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
3181 Image Name: Simple Ramdisk Image
3182 Created: Wed Jan 12 14:01:50 2000
3183 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
3184 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
3185 Load Address: 0x00000000
3186 Entry Point: 0x00000000
3189 Installing a Linux Image:
3190 -------------------------
3192 To downloading a U-Boot image over the serial (console) interface,
3193 you must convert the image to S-Record format:
3195 objcopy -I binary -O srec examples/image examples/image.srec
3197 The 'objcopy' does not understand the information in the U-Boot
3198 image header, so the resulting S-Record file will be relative to
3199 address 0x00000000. To load it to a given address, you need to
3200 specify the target address as 'offset' parameter with the 'loads'
3203 Example: install the image to address 0x40100000 (which on the
3204 TQM8xxL is in the first Flash bank):
3206 => erase 40100000 401FFFFF
3212 ## Ready for S-Record download ...
3213 ~>examples/image.srec
3214 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
3216 15989 15990 15991 15992
3217 [file transfer complete]
3219 ## Start Addr = 0x00000000
3222 You can check the success of the download using the 'iminfo' command;
3223 this includes a checksum verification so you can be sure no data
3224 corruption happened:
3228 ## Checking Image at 40100000 ...
3229 Image Name: 2.2.13 for initrd on TQM850L
3230 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3231 Data Size: 335725 Bytes = 327 kB = 0 MB
3232 Load Address: 00000000
3233 Entry Point: 0000000c
3234 Verifying Checksum ... OK
3240 The "bootm" command is used to boot an application that is stored in
3241 memory (RAM or Flash). In case of a Linux kernel image, the contents
3242 of the "bootargs" environment variable is passed to the kernel as
3243 parameters. You can check and modify this variable using the
3244 "printenv" and "setenv" commands:
3247 => printenv bootargs
3248 bootargs=root=/dev/ram
3250 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
3252 => printenv bootargs
3253 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
3256 ## Booting Linux kernel at 40020000 ...
3257 Image Name: 2.2.13 for NFS on TQM850L
3258 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3259 Data Size: 381681 Bytes = 372 kB = 0 MB
3260 Load Address: 00000000
3261 Entry Point: 0000000c
3262 Verifying Checksum ... OK
3263 Uncompressing Kernel Image ... OK
3264 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
3265 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
3266 time_init: decrementer frequency = 187500000/60
3267 Calibrating delay loop... 49.77 BogoMIPS
3268 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
3271 If you want to boot a Linux kernel with initial ram disk, you pass
3272 the memory addresses of both the kernel and the initrd image (PPBCOOT
3273 format!) to the "bootm" command:
3275 => imi 40100000 40200000
3277 ## Checking Image at 40100000 ...
3278 Image Name: 2.2.13 for initrd on TQM850L
3279 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3280 Data Size: 335725 Bytes = 327 kB = 0 MB
3281 Load Address: 00000000
3282 Entry Point: 0000000c
3283 Verifying Checksum ... OK
3285 ## Checking Image at 40200000 ...
3286 Image Name: Simple Ramdisk Image
3287 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
3288 Data Size: 566530 Bytes = 553 kB = 0 MB
3289 Load Address: 00000000
3290 Entry Point: 00000000
3291 Verifying Checksum ... OK
3293 => bootm 40100000 40200000
3294 ## Booting Linux kernel at 40100000 ...
3295 Image Name: 2.2.13 for initrd on TQM850L
3296 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3297 Data Size: 335725 Bytes = 327 kB = 0 MB
3298 Load Address: 00000000
3299 Entry Point: 0000000c
3300 Verifying Checksum ... OK
3301 Uncompressing Kernel Image ... OK
3302 ## Loading RAMDisk Image at 40200000 ...
3303 Image Name: Simple Ramdisk Image
3304 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
3305 Data Size: 566530 Bytes = 553 kB = 0 MB
3306 Load Address: 00000000
3307 Entry Point: 00000000
3308 Verifying Checksum ... OK
3309 Loading Ramdisk ... OK
3310 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
3311 Boot arguments: root=/dev/ram
3312 time_init: decrementer frequency = 187500000/60
3313 Calibrating delay loop... 49.77 BogoMIPS
3315 RAMDISK: Compressed image found at block 0
3316 VFS: Mounted root (ext2 filesystem).
3320 Boot Linux and pass a flat device tree:
3323 First, U-Boot must be compiled with the appropriate defines. See the section
3324 titled "Linux Kernel Interface" above for a more in depth explanation. The
3325 following is an example of how to start a kernel and pass an updated
3331 oft=oftrees/mpc8540ads.dtb
3332 => tftp $oftaddr $oft
3333 Speed: 1000, full duplex
3335 TFTP from server 192.168.1.1; our IP address is 192.168.1.101
3336 Filename 'oftrees/mpc8540ads.dtb'.
3337 Load address: 0x300000
3340 Bytes transferred = 4106 (100a hex)
3341 => tftp $loadaddr $bootfile
3342 Speed: 1000, full duplex
3344 TFTP from server 192.168.1.1; our IP address is 192.168.1.2
3346 Load address: 0x200000
3347 Loading:############
3349 Bytes transferred = 1029407 (fb51f hex)
3354 => bootm $loadaddr - $oftaddr
3355 ## Booting image at 00200000 ...
3356 Image Name: Linux-2.6.17-dirty
3357 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3358 Data Size: 1029343 Bytes = 1005.2 kB
3359 Load Address: 00000000
3360 Entry Point: 00000000
3361 Verifying Checksum ... OK
3362 Uncompressing Kernel Image ... OK
3363 Booting using flat device tree at 0x300000
3364 Using MPC85xx ADS machine description
3365 Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb
3369 More About U-Boot Image Types:
3370 ------------------------------
3372 U-Boot supports the following image types:
3374 "Standalone Programs" are directly runnable in the environment
3375 provided by U-Boot; it is expected that (if they behave
3376 well) you can continue to work in U-Boot after return from
3377 the Standalone Program.
3378 "OS Kernel Images" are usually images of some Embedded OS which
3379 will take over control completely. Usually these programs
3380 will install their own set of exception handlers, device
3381 drivers, set up the MMU, etc. - this means, that you cannot
3382 expect to re-enter U-Boot except by resetting the CPU.
3383 "RAMDisk Images" are more or less just data blocks, and their
3384 parameters (address, size) are passed to an OS kernel that is
3386 "Multi-File Images" contain several images, typically an OS
3387 (Linux) kernel image and one or more data images like
3388 RAMDisks. This construct is useful for instance when you want
3389 to boot over the network using BOOTP etc., where the boot
3390 server provides just a single image file, but you want to get
3391 for instance an OS kernel and a RAMDisk image.
3393 "Multi-File Images" start with a list of image sizes, each
3394 image size (in bytes) specified by an "uint32_t" in network
3395 byte order. This list is terminated by an "(uint32_t)0".
3396 Immediately after the terminating 0 follow the images, one by
3397 one, all aligned on "uint32_t" boundaries (size rounded up to
3398 a multiple of 4 bytes).
3400 "Firmware Images" are binary images containing firmware (like
3401 U-Boot or FPGA images) which usually will be programmed to
3404 "Script files" are command sequences that will be executed by
3405 U-Boot's command interpreter; this feature is especially
3406 useful when you configure U-Boot to use a real shell (hush)
3407 as command interpreter.
3413 One of the features of U-Boot is that you can dynamically load and
3414 run "standalone" applications, which can use some resources of
3415 U-Boot like console I/O functions or interrupt services.
3417 Two simple examples are included with the sources:
3422 'examples/hello_world.c' contains a small "Hello World" Demo
3423 application; it is automatically compiled when you build U-Boot.
3424 It's configured to run at address 0x00040004, so you can play with it
3428 ## Ready for S-Record download ...
3429 ~>examples/hello_world.srec
3430 1 2 3 4 5 6 7 8 9 10 11 ...
3431 [file transfer complete]
3433 ## Start Addr = 0x00040004
3435 => go 40004 Hello World! This is a test.
3436 ## Starting application at 0x00040004 ...
3447 Hit any key to exit ...
3449 ## Application terminated, rc = 0x0
3451 Another example, which demonstrates how to register a CPM interrupt
3452 handler with the U-Boot code, can be found in 'examples/timer.c'.
3453 Here, a CPM timer is set up to generate an interrupt every second.
3454 The interrupt service routine is trivial, just printing a '.'
3455 character, but this is just a demo program. The application can be
3456 controlled by the following keys:
3458 ? - print current values og the CPM Timer registers
3459 b - enable interrupts and start timer
3460 e - stop timer and disable interrupts
3461 q - quit application
3464 ## Ready for S-Record download ...
3465 ~>examples/timer.srec
3466 1 2 3 4 5 6 7 8 9 10 11 ...
3467 [file transfer complete]
3469 ## Start Addr = 0x00040004
3472 ## Starting application at 0x00040004 ...
3475 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
3478 [q, b, e, ?] Set interval 1000000 us
3481 [q, b, e, ?] ........
3482 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
3485 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
3488 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
3491 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
3493 [q, b, e, ?] ...Stopping timer
3495 [q, b, e, ?] ## Application terminated, rc = 0x0
3501 Over time, many people have reported problems when trying to use the
3502 "minicom" terminal emulation program for serial download. I (wd)
3503 consider minicom to be broken, and recommend not to use it. Under
3504 Unix, I recommend to use C-Kermit for general purpose use (and
3505 especially for kermit binary protocol download ("loadb" command), and
3506 use "cu" for S-Record download ("loads" command).
3508 Nevertheless, if you absolutely want to use it try adding this
3509 configuration to your "File transfer protocols" section:
3511 Name Program Name U/D FullScr IO-Red. Multi
3512 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
3513 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
3519 Starting at version 0.9.2, U-Boot supports NetBSD both as host
3520 (build U-Boot) and target system (boots NetBSD/mpc8xx).
3522 Building requires a cross environment; it is known to work on
3523 NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
3524 need gmake since the Makefiles are not compatible with BSD make).
3525 Note that the cross-powerpc package does not install include files;
3526 attempting to build U-Boot will fail because <machine/ansi.h> is
3527 missing. This file has to be installed and patched manually:
3529 # cd /usr/pkg/cross/powerpc-netbsd/include
3531 # ln -s powerpc machine
3532 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
3533 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
3535 Native builds *don't* work due to incompatibilities between native
3536 and U-Boot include files.
3538 Booting assumes that (the first part of) the image booted is a
3539 stage-2 loader which in turn loads and then invokes the kernel
3540 proper. Loader sources will eventually appear in the NetBSD source
3541 tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
3542 meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz
3545 Implementation Internals:
3546 =========================
3548 The following is not intended to be a complete description of every
3549 implementation detail. However, it should help to understand the
3550 inner workings of U-Boot and make it easier to port it to custom
3554 Initial Stack, Global Data:
3555 ---------------------------
3557 The implementation of U-Boot is complicated by the fact that U-Boot
3558 starts running out of ROM (flash memory), usually without access to
3559 system RAM (because the memory controller is not initialized yet).
3560 This means that we don't have writable Data or BSS segments, and BSS
3561 is not initialized as zero. To be able to get a C environment working
3562 at all, we have to allocate at least a minimal stack. Implementation
3563 options for this are defined and restricted by the CPU used: Some CPU
3564 models provide on-chip memory (like the IMMR area on MPC8xx and
3565 MPC826x processors), on others (parts of) the data cache can be
3566 locked as (mis-) used as memory, etc.
3568 Chris Hallinan posted a good summary of these issues to the
3569 u-boot-users mailing list:
3571 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
3572 From: "Chris Hallinan" <clh@net1plus.com>
3573 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
3576 Correct me if I'm wrong, folks, but the way I understand it
3577 is this: Using DCACHE as initial RAM for Stack, etc, does not
3578 require any physical RAM backing up the cache. The cleverness
3579 is that the cache is being used as a temporary supply of
3580 necessary storage before the SDRAM controller is setup. It's
3581 beyond the scope of this list to expain the details, but you
3582 can see how this works by studying the cache architecture and
3583 operation in the architecture and processor-specific manuals.
3585 OCM is On Chip Memory, which I believe the 405GP has 4K. It
3586 is another option for the system designer to use as an
3587 initial stack/ram area prior to SDRAM being available. Either
3588 option should work for you. Using CS 4 should be fine if your
3589 board designers haven't used it for something that would
3590 cause you grief during the initial boot! It is frequently not
3593 CFG_INIT_RAM_ADDR should be somewhere that won't interfere
3594 with your processor/board/system design. The default value
3595 you will find in any recent u-boot distribution in
3596 walnut.h should work for you. I'd set it to a value larger
3597 than your SDRAM module. If you have a 64MB SDRAM module, set
3598 it above 400_0000. Just make sure your board has no resources
3599 that are supposed to respond to that address! That code in
3600 start.S has been around a while and should work as is when
3601 you get the config right.
3606 It is essential to remember this, since it has some impact on the C
3607 code for the initialization procedures:
3609 * Initialized global data (data segment) is read-only. Do not attempt
3612 * Do not use any unitialized global data (or implicitely initialized
3613 as zero data - BSS segment) at all - this is undefined, initiali-
3614 zation is performed later (when relocating to RAM).
3616 * Stack space is very limited. Avoid big data buffers or things like
3619 Having only the stack as writable memory limits means we cannot use
3620 normal global data to share information beween the code. But it
3621 turned out that the implementation of U-Boot can be greatly
3622 simplified by making a global data structure (gd_t) available to all
3623 functions. We could pass a pointer to this data as argument to _all_
3624 functions, but this would bloat the code. Instead we use a feature of
3625 the GCC compiler (Global Register Variables) to share the data: we
3626 place a pointer (gd) to the global data into a register which we
3627 reserve for this purpose.
3629 When choosing a register for such a purpose we are restricted by the
3630 relevant (E)ABI specifications for the current architecture, and by
3631 GCC's implementation.
3633 For PowerPC, the following registers have specific use:
3635 R2: reserved for system use
3636 R3-R4: parameter passing and return values
3637 R5-R10: parameter passing
3638 R13: small data area pointer
3642 (U-Boot also uses R14 as internal GOT pointer.)
3644 ==> U-Boot will use R2 to hold a pointer to the global data
3646 Note: on PPC, we could use a static initializer (since the
3647 address of the global data structure is known at compile time),
3648 but it turned out that reserving a register results in somewhat
3649 smaller code - although the code savings are not that big (on
3650 average for all boards 752 bytes for the whole U-Boot image,
3651 624 text + 127 data).
3653 On Blackfin, the normal C ABI (except for P5) is followed as documented here:
3654 http://docs.blackfin.uclinux.org/doku.php?id=application_binary_interface
3656 ==> U-Boot will use P5 to hold a pointer to the global data
3658 On ARM, the following registers are used:
3660 R0: function argument word/integer result
3661 R1-R3: function argument word
3663 R10: stack limit (used only if stack checking if enabled)
3664 R11: argument (frame) pointer
3665 R12: temporary workspace
3668 R15: program counter
3670 ==> U-Boot will use R8 to hold a pointer to the global data
3672 NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope,
3673 or current versions of GCC may "optimize" the code too much.
3678 U-Boot runs in system state and uses physical addresses, i.e. the
3679 MMU is not used either for address mapping nor for memory protection.
3681 The available memory is mapped to fixed addresses using the memory
3682 controller. In this process, a contiguous block is formed for each
3683 memory type (Flash, SDRAM, SRAM), even when it consists of several
3684 physical memory banks.
3686 U-Boot is installed in the first 128 kB of the first Flash bank (on
3687 TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
3688 booting and sizing and initializing DRAM, the code relocates itself
3689 to the upper end of DRAM. Immediately below the U-Boot code some
3690 memory is reserved for use by malloc() [see CFG_MALLOC_LEN
3691 configuration setting]. Below that, a structure with global Board
3692 Info data is placed, followed by the stack (growing downward).
3694 Additionally, some exception handler code is copied to the low 8 kB
3695 of DRAM (0x00000000 ... 0x00001FFF).
3697 So a typical memory configuration with 16 MB of DRAM could look like
3700 0x0000 0000 Exception Vector code
3703 0x0000 2000 Free for Application Use
3709 0x00FB FF20 Monitor Stack (Growing downward)
3710 0x00FB FFAC Board Info Data and permanent copy of global data
3711 0x00FC 0000 Malloc Arena
3714 0x00FE 0000 RAM Copy of Monitor Code
3715 ... eventually: LCD or video framebuffer
3716 ... eventually: pRAM (Protected RAM - unchanged by reset)
3717 0x00FF FFFF [End of RAM]
3720 System Initialization:
3721 ----------------------
3723 In the reset configuration, U-Boot starts at the reset entry point
3724 (on most PowerPC systens at address 0x00000100). Because of the reset
3725 configuration for CS0# this is a mirror of the onboard Flash memory.
3726 To be able to re-map memory U-Boot then jumps to its link address.
3727 To be able to implement the initialization code in C, a (small!)
3728 initial stack is set up in the internal Dual Ported RAM (in case CPUs
3729 which provide such a feature like MPC8xx or MPC8260), or in a locked
3730 part of the data cache. After that, U-Boot initializes the CPU core,
3731 the caches and the SIU.
3733 Next, all (potentially) available memory banks are mapped using a
3734 preliminary mapping. For example, we put them on 512 MB boundaries
3735 (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
3736 on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
3737 programmed for SDRAM access. Using the temporary configuration, a
3738 simple memory test is run that determines the size of the SDRAM
3741 When there is more than one SDRAM bank, and the banks are of
3742 different size, the largest is mapped first. For equal size, the first
3743 bank (CS2#) is mapped first. The first mapping is always for address
3744 0x00000000, with any additional banks following immediately to create
3745 contiguous memory starting from 0.
3747 Then, the monitor installs itself at the upper end of the SDRAM area
3748 and allocates memory for use by malloc() and for the global Board
3749 Info data; also, the exception vector code is copied to the low RAM
3750 pages, and the final stack is set up.
3752 Only after this relocation will you have a "normal" C environment;
3753 until that you are restricted in several ways, mostly because you are
3754 running from ROM, and because the code will have to be relocated to a
3758 U-Boot Porting Guide:
3759 ----------------------
3761 [Based on messages by Jerry Van Baren in the U-Boot-Users mailing
3765 int main (int argc, char *argv[])
3767 sighandler_t no_more_time;
3769 signal (SIGALRM, no_more_time);
3770 alarm (PROJECT_DEADLINE - toSec (3 * WEEK));
3772 if (available_money > available_manpower) {
3773 pay consultant to port U-Boot;
3777 Download latest U-Boot source;
3779 Subscribe to u-boot-users mailing list;
3782 email ("Hi, I am new to U-Boot, how do I get started?");
3786 Read the README file in the top level directory;
3787 Read http://www.denx.de/twiki/bin/view/DULG/Manual ;
3788 Read the source, Luke;
3791 if (available_money > toLocalCurrency ($2500)) {
3794 Add a lot of aggravation and time;
3797 Create your own board support subdirectory;
3799 Create your own board config file;
3803 Add / modify source code;
3807 email ("Hi, I am having problems...");
3809 Send patch file to Wolfgang;
3814 void no_more_time (int sig)
3823 All contributions to U-Boot should conform to the Linux kernel
3824 coding style; see the file "Documentation/CodingStyle" and the script
3825 "scripts/Lindent" in your Linux kernel source directory. In sources
3826 originating from U-Boot a style corresponding to "Lindent -pcs" (adding
3827 spaces before parameters to function calls) is actually used.
3829 Source files originating from a different project (for example the
3830 MTD subsystem) are generally exempt from these guidelines and are not
3831 reformated to ease subsequent migration to newer versions of those
3834 Please note that U-Boot is implemented in C (and to some small parts in
3835 Assembler); no C++ is used, so please do not use C++ style comments (//)
3838 Please also stick to the following formatting rules:
3839 - remove any trailing white space
3840 - use TAB characters for indentation, not spaces
3841 - make sure NOT to use DOS '\r\n' line feeds
3842 - do not add more than 2 empty lines to source files
3843 - do not add trailing empty lines to source files
3845 Submissions which do not conform to the standards may be returned
3846 with a request to reformat the changes.
3852 Since the number of patches for U-Boot is growing, we need to
3853 establish some rules. Submissions which do not conform to these rules
3854 may be rejected, even when they contain important and valuable stuff.
3856 Patches shall be sent to the u-boot-users mailing list.
3858 Please see http://www.denx.de/wiki/UBoot/Patches for details.
3860 When you send a patch, please include the following information with
3863 * For bug fixes: a description of the bug and how your patch fixes
3864 this bug. Please try to include a way of demonstrating that the
3865 patch actually fixes something.
3867 * For new features: a description of the feature and your
3870 * A CHANGELOG entry as plaintext (separate from the patch)
3872 * For major contributions, your entry to the CREDITS file
3874 * When you add support for a new board, don't forget to add this
3875 board to the MAKEALL script, too.
3877 * If your patch adds new configuration options, don't forget to
3878 document these in the README file.
3880 * The patch itself. If you are using git (which is *strongly*
3881 recommended) you can easily generate the patch using the
3882 "git-format-patch". If you then use "git-send-email" to send it to
3883 the U-Boot mailing list, you will avoid most of the common problems
3884 with some other mail clients.
3886 If you cannot use git, use "diff -purN OLD NEW". If your version of
3887 diff does not support these options, then get the latest version of
3890 The current directory when running this command shall be the parent
3891 directory of the U-Boot source tree (i. e. please make sure that
3892 your patch includes sufficient directory information for the
3895 We prefer patches as plain text. MIME attachments are discouraged,
3896 and compressed attachments must not be used.
3898 * If one logical set of modifications affects or creates several
3899 files, all these changes shall be submitted in a SINGLE patch file.
3901 * Changesets that contain different, unrelated modifications shall be
3902 submitted as SEPARATE patches, one patch per changeset.
3907 * Before sending the patch, run the MAKEALL script on your patched
3908 source tree and make sure that no errors or warnings are reported
3909 for any of the boards.
3911 * Keep your modifications to the necessary minimum: A patch
3912 containing several unrelated changes or arbitrary reformats will be
3913 returned with a request to re-formatting / split it.
3915 * If you modify existing code, make sure that your new code does not
3916 add to the memory footprint of the code ;-) Small is beautiful!
3917 When adding new features, these should compile conditionally only
3918 (using #ifdef), and the resulting code with the new feature
3919 disabled must not need more memory than the old code without your
3922 * Remember that there is a size limit of 40 kB per message on the
3923 u-boot-users mailing list. Bigger patches will be moderated. If
3924 they are reasonable and not bigger than 100 kB, they will be
3925 acknowledged. Even bigger patches should be avoided.
projects / people / ms / u-boot.git / blob