2 # (C) Copyright 2000 - 2008
3 # Wolfgang Denk, DENX Software Engineering, wd@denx.de.
5 # See file CREDITS for list of people who contributed to this
8 # This program is free software; you can redistribute it and/or
9 # modify it under the terms of the GNU General Public License as
10 # published by the Free Software Foundation; either version 2 of
11 # the License, or (at your option) any later version.
13 # This program is distributed in the hope that it will be useful,
14 # but WITHOUT ANY WARRANTY; without even the implied warranty of
15 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 # GNU General Public License for more details.
18 # You should have received a copy of the GNU General Public License
19 # along with this program; if not, write to the Free Software
20 # Foundation, Inc., 59 Temple Place, Suite 330, Boston,
27 This directory contains the source code for U-Boot, a boot loader for
28 Embedded boards based on PowerPC, ARM, MIPS and several other
29 processors, which can be installed in a boot ROM and used to
30 initialize and test the hardware or to download and run application
33 The development of U-Boot is closely related to Linux: some parts of
34 the source code originate in the Linux source tree, we have some
35 header files in common, and special provision has been made to
36 support booting of Linux images.
38 Some attention has been paid to make this software easily
39 configurable and extendable. For instance, all monitor commands are
40 implemented with the same call interface, so that it's very easy to
41 add new commands. Also, instead of permanently adding rarely used
42 code (for instance hardware test utilities) to the monitor, you can
43 load and run it dynamically.
49 In general, all boards for which a configuration option exists in the
50 Makefile have been tested to some extent and can be considered
51 "working". In fact, many of them are used in production systems.
53 In case of problems see the CHANGELOG and CREDITS files to find out
54 who contributed the specific port. The MAINTAINERS file lists board
61 In case you have questions about, problems with or contributions for
62 U-Boot you should send a message to the U-Boot mailing list at
63 <u-boot-users@lists.sourceforge.net>. There is also an archive of
64 previous traffic on the mailing list - please search the archive
65 before asking FAQ's. Please see
66 http://lists.sourceforge.net/lists/listinfo/u-boot-users/
69 Where to get source code:
70 =========================
72 The U-Boot source code is maintained in the git repository at
73 git://www.denx.de/git/u-boot.git ; you can browse it online at
74 http://www.denx.de/cgi-bin/gitweb.cgi?p=u-boot.git;a=summary
76 The "snapshot" links on this page allow you to download tarballs of
77 any version you might be interested in. Ofifcial releases are also
78 available for FTP download from the ftp://ftp.denx.de/pub/u-boot/
81 Pre-built (and tested) images are available from
82 ftp://ftp.denx.de/pub/u-boot/images/
88 - start from 8xxrom sources
89 - create PPCBoot project (http://sourceforge.net/projects/ppcboot)
91 - make it easier to add custom boards
92 - make it possible to add other [PowerPC] CPUs
93 - extend functions, especially:
94 * Provide extended interface to Linux boot loader
97 * PCMCIA / CompactFLash / ATA disk / SCSI ... boot
98 - create ARMBoot project (http://sourceforge.net/projects/armboot)
99 - add other CPU families (starting with ARM)
100 - create U-Boot project (http://sourceforge.net/projects/u-boot)
101 - current project page: see http://www.denx.de/wiki/UBoot
107 The "official" name of this project is "Das U-Boot". The spelling
108 "U-Boot" shall be used in all written text (documentation, comments
109 in source files etc.). Example:
111 This is the README file for the U-Boot project.
113 File names etc. shall be based on the string "u-boot". Examples:
115 include/asm-ppc/u-boot.h
117 #include <asm/u-boot.h>
119 Variable names, preprocessor constants etc. shall be either based on
120 the string "u_boot" or on "U_BOOT". Example:
122 U_BOOT_VERSION u_boot_logo
123 IH_OS_U_BOOT u_boot_hush_start
129 U-Boot uses a 3 level version number containing a version, a
130 sub-version, and a patchlevel: "U-Boot-2.34.5" means version "2",
131 sub-version "34", and patchlevel "4".
133 The patchlevel is used to indicate certain stages of development
134 between released versions, i. e. officially released versions of
135 U-Boot will always have a patchlevel of "0".
141 - board Board dependent files
142 - common Misc architecture independent functions
143 - cpu CPU specific files
144 - 74xx_7xx Files specific to Freescale MPC74xx and 7xx CPUs
145 - arm720t Files specific to ARM 720 CPUs
146 - arm920t Files specific to ARM 920 CPUs
147 - at91rm9200 Files specific to Atmel AT91RM9200 CPU
148 - imx Files specific to Freescale MC9328 i.MX CPUs
149 - s3c24x0 Files specific to Samsung S3C24X0 CPUs
150 - arm925t Files specific to ARM 925 CPUs
151 - arm926ejs Files specific to ARM 926 CPUs
152 - arm1136 Files specific to ARM 1136 CPUs
153 - at32ap Files specific to Atmel AVR32 AP CPUs
154 - i386 Files specific to i386 CPUs
155 - ixp Files specific to Intel XScale IXP CPUs
156 - leon2 Files specific to Gaisler LEON2 SPARC CPU
157 - leon3 Files specific to Gaisler LEON3 SPARC CPU
158 - mcf52x2 Files specific to Freescale ColdFire MCF52x2 CPUs
159 - mcf5227x Files specific to Freescale ColdFire MCF5227x CPUs
160 - mcf532x Files specific to Freescale ColdFire MCF5329 CPUs
161 - mcf5445x Files specific to Freescale ColdFire MCF5445x CPUs
162 - mcf547x_8x Files specific to Freescale ColdFire MCF547x_8x CPUs
163 - mips Files specific to MIPS CPUs
164 - mpc5xx Files specific to Freescale MPC5xx CPUs
165 - mpc5xxx Files specific to Freescale MPC5xxx CPUs
166 - mpc8xx Files specific to Freescale MPC8xx CPUs
167 - mpc8220 Files specific to Freescale MPC8220 CPUs
168 - mpc824x Files specific to Freescale MPC824x CPUs
169 - mpc8260 Files specific to Freescale MPC8260 CPUs
170 - mpc85xx Files specific to Freescale MPC85xx CPUs
171 - nios Files specific to Altera NIOS CPUs
172 - nios2 Files specific to Altera Nios-II CPUs
173 - ppc4xx Files specific to AMCC PowerPC 4xx CPUs
174 - pxa Files specific to Intel XScale PXA CPUs
175 - s3c44b0 Files specific to Samsung S3C44B0 CPUs
176 - sa1100 Files specific to Intel StrongARM SA1100 CPUs
177 - disk Code for disk drive partition handling
178 - doc Documentation (don't expect too much)
179 - drivers Commonly used device drivers
180 - dtt Digital Thermometer and Thermostat drivers
181 - examples Example code for standalone applications, etc.
182 - include Header Files
183 - lib_arm Files generic to ARM architecture
184 - lib_avr32 Files generic to AVR32 architecture
185 - lib_generic Files generic to all architectures
186 - lib_i386 Files generic to i386 architecture
187 - lib_m68k Files generic to m68k architecture
188 - lib_mips Files generic to MIPS architecture
189 - lib_nios Files generic to NIOS architecture
190 - lib_ppc Files generic to PowerPC architecture
191 - lib_sparc Files generic to SPARC architecture
192 - libfdt Library files to support flattened device trees
193 - net Networking code
194 - post Power On Self Test
195 - rtc Real Time Clock drivers
196 - tools Tools to build S-Record or U-Boot images, etc.
198 Software Configuration:
199 =======================
201 Configuration is usually done using C preprocessor defines; the
202 rationale behind that is to avoid dead code whenever possible.
204 There are two classes of configuration variables:
206 * Configuration _OPTIONS_:
207 These are selectable by the user and have names beginning with
210 * Configuration _SETTINGS_:
211 These depend on the hardware etc. and should not be meddled with if
212 you don't know what you're doing; they have names beginning with
215 Later we will add a configuration tool - probably similar to or even
216 identical to what's used for the Linux kernel. Right now, we have to
217 do the configuration by hand, which means creating some symbolic
218 links and editing some configuration files. We use the TQM8xxL boards
222 Selection of Processor Architecture and Board Type:
223 ---------------------------------------------------
225 For all supported boards there are ready-to-use default
226 configurations available; just type "make <board_name>_config".
228 Example: For a TQM823L module type:
233 For the Cogent platform, you need to specify the cpu type as well;
234 e.g. "make cogent_mpc8xx_config". And also configure the cogent
235 directory according to the instructions in cogent/README.
238 Configuration Options:
239 ----------------------
241 Configuration depends on the combination of board and CPU type; all
242 such information is kept in a configuration file
243 "include/configs/<board_name>.h".
245 Example: For a TQM823L module, all configuration settings are in
246 "include/configs/TQM823L.h".
249 Many of the options are named exactly as the corresponding Linux
250 kernel configuration options. The intention is to make it easier to
251 build a config tool - later.
254 The following options need to be configured:
256 - CPU Type: Define exactly one, e.g. CONFIG_MPC85XX.
258 - Board Type: Define exactly one, e.g. CONFIG_MPC8540ADS.
260 - CPU Daughterboard Type: (if CONFIG_ATSTK1000 is defined)
261 Define exactly one, e.g. CONFIG_ATSTK1002
263 - CPU Module Type: (if CONFIG_COGENT is defined)
264 Define exactly one of
266 --- FIXME --- not tested yet:
267 CONFIG_CMA286_60, CONFIG_CMA286_21, CONFIG_CMA286_60P,
268 CONFIG_CMA287_23, CONFIG_CMA287_50
270 - Motherboard Type: (if CONFIG_COGENT is defined)
271 Define exactly one of
272 CONFIG_CMA101, CONFIG_CMA102
274 - Motherboard I/O Modules: (if CONFIG_COGENT is defined)
275 Define one or more of
278 - Motherboard Options: (if CONFIG_CMA101 or CONFIG_CMA102 are defined)
279 Define one or more of
280 CONFIG_LCD_HEARTBEAT - update a character position on
281 the lcd display every second with
284 - Board flavour: (if CONFIG_MPC8260ADS is defined)
287 CFG_8260ADS - original MPC8260ADS
288 CFG_8266ADS - MPC8266ADS
289 CFG_PQ2FADS - PQ2FADS-ZU or PQ2FADS-VR
290 CFG_8272ADS - MPC8272ADS
292 - MPC824X Family Member (if CONFIG_MPC824X is defined)
293 Define exactly one of
294 CONFIG_MPC8240, CONFIG_MPC8245
296 - 8xx CPU Options: (if using an MPC8xx cpu)
297 CONFIG_8xx_GCLK_FREQ - deprecated: CPU clock if
298 get_gclk_freq() cannot work
299 e.g. if there is no 32KHz
300 reference PIT/RTC clock
301 CONFIG_8xx_OSCLK - PLL input clock (either EXTCLK
304 - 859/866/885 CPU options: (if using a MPC859 or MPC866 or MPC885 CPU):
307 CONFIG_8xx_CPUCLK_DEFAULT
308 See doc/README.MPC866
312 Define this to measure the actual CPU clock instead
313 of relying on the correctness of the configured
314 values. Mostly useful for board bringup to make sure
315 the PLL is locked at the intended frequency. Note
316 that this requires a (stable) reference clock (32 kHz
317 RTC clock or CFG_8XX_XIN)
319 - Intel Monahans options:
320 CFG_MONAHANS_RUN_MODE_OSC_RATIO
322 Defines the Monahans run mode to oscillator
323 ratio. Valid values are 8, 16, 24, 31. The core
324 frequency is this value multiplied by 13 MHz.
326 CFG_MONAHANS_TURBO_RUN_MODE_RATIO
328 Defines the Monahans turbo mode to oscillator
329 ratio. Valid values are 1 (default if undefined) and
330 2. The core frequency as calculated above is multiplied
333 - Linux Kernel Interface:
336 U-Boot stores all clock information in Hz
337 internally. For binary compatibility with older Linux
338 kernels (which expect the clocks passed in the
339 bd_info data to be in MHz) the environment variable
340 "clocks_in_mhz" can be defined so that U-Boot
341 converts clock data to MHZ before passing it to the
343 When CONFIG_CLOCKS_IN_MHZ is defined, a definition of
344 "clocks_in_mhz=1" is automatically included in the
347 CONFIG_MEMSIZE_IN_BYTES [relevant for MIPS only]
349 When transfering memsize parameter to linux, some versions
350 expect it to be in bytes, others in MB.
351 Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes.
353 CONFIG_OF_LIBFDT / CONFIG_OF_FLAT_TREE
355 New kernel versions are expecting firmware settings to be
356 passed using flattened device trees (based on open firmware
360 * New libfdt-based support
361 * Adds the "fdt" command
362 * The bootm command automatically updates the fdt
365 * Deprecated, see CONFIG_OF_LIBFDT
366 * Original ft_build.c-based support
367 * Automatically modifies the dft as part of the bootm command
368 * The environment variable "disable_of", when set,
369 disables this functionality.
371 OF_CPU - The proper name of the cpus node.
372 OF_SOC - The proper name of the soc node.
373 OF_TBCLK - The timebase frequency.
374 OF_STDOUT_PATH - The path to the console device
376 boards with QUICC Engines require OF_QE to set UCC mac addresses
378 CONFIG_OF_BOARD_SETUP
380 Board code has addition modification that it wants to make
381 to the flat device tree before handing it off to the kernel
385 This define fills in the correct boot cpu in the boot
386 param header, the default value is zero if undefined.
391 Define this if you want support for Amba PrimeCell PL010 UARTs.
395 Define this if you want support for Amba PrimeCell PL011 UARTs.
399 If you have Amba PrimeCell PL011 UARTs, set this variable to
400 the clock speed of the UARTs.
404 If you have Amba PrimeCell PL010 or PL011 UARTs on your board,
405 define this to a list of base addresses for each (supported)
406 port. See e.g. include/configs/versatile.h
410 Depending on board, define exactly one serial port
411 (like CONFIG_8xx_CONS_SMC1, CONFIG_8xx_CONS_SMC2,
412 CONFIG_8xx_CONS_SCC1, ...), or switch off the serial
413 console by defining CONFIG_8xx_CONS_NONE
415 Note: if CONFIG_8xx_CONS_NONE is defined, the serial
416 port routines must be defined elsewhere
417 (i.e. serial_init(), serial_getc(), ...)
420 Enables console device for a color framebuffer. Needs following
421 defines (cf. smiLynxEM, i8042, board/eltec/bab7xx)
422 VIDEO_FB_LITTLE_ENDIAN graphic memory organisation
424 VIDEO_HW_RECTFILL graphic chip supports
427 VIDEO_HW_BITBLT graphic chip supports
428 bit-blit (cf. smiLynxEM)
429 VIDEO_VISIBLE_COLS visible pixel columns
431 VIDEO_VISIBLE_ROWS visible pixel rows
432 VIDEO_PIXEL_SIZE bytes per pixel
433 VIDEO_DATA_FORMAT graphic data format
434 (0-5, cf. cfb_console.c)
435 VIDEO_FB_ADRS framebuffer address
436 VIDEO_KBD_INIT_FCT keyboard int fct
437 (i.e. i8042_kbd_init())
438 VIDEO_TSTC_FCT test char fct
440 VIDEO_GETC_FCT get char fct
442 CONFIG_CONSOLE_CURSOR cursor drawing on/off
443 (requires blink timer
445 CFG_CONSOLE_BLINK_COUNT blink interval (cf. i8042.c)
446 CONFIG_CONSOLE_TIME display time/date info in
448 (requires CONFIG_CMD_DATE)
449 CONFIG_VIDEO_LOGO display Linux logo in
451 CONFIG_VIDEO_BMP_LOGO use bmp_logo.h instead of
452 linux_logo.h for logo.
453 Requires CONFIG_VIDEO_LOGO
454 CONFIG_CONSOLE_EXTRA_INFO
455 addional board info beside
458 When CONFIG_CFB_CONSOLE is defined, video console is
459 default i/o. Serial console can be forced with
460 environment 'console=serial'.
462 When CONFIG_SILENT_CONSOLE is defined, all console
463 messages (by U-Boot and Linux!) can be silenced with
464 the "silent" environment variable. See
465 doc/README.silent for more information.
468 CONFIG_BAUDRATE - in bps
469 Select one of the baudrates listed in
470 CFG_BAUDRATE_TABLE, see below.
471 CFG_BRGCLK_PRESCALE, baudrate prescale
473 - Interrupt driven serial port input:
474 CONFIG_SERIAL_SOFTWARE_FIFO
477 Use an interrupt handler for receiving data on the
478 serial port. It also enables using hardware handshake
479 (RTS/CTS) and UART's built-in FIFO. Set the number of
480 bytes the interrupt driven input buffer should have.
482 Leave undefined to disable this feature, including
483 disable the buffer and hardware handshake.
485 - Console UART Number:
489 If defined internal UART1 (and not UART0) is used
490 as default U-Boot console.
492 - Boot Delay: CONFIG_BOOTDELAY - in seconds
493 Delay before automatically booting the default image;
494 set to -1 to disable autoboot.
496 See doc/README.autoboot for these options that
497 work with CONFIG_BOOTDELAY. None are required.
498 CONFIG_BOOT_RETRY_TIME
499 CONFIG_BOOT_RETRY_MIN
500 CONFIG_AUTOBOOT_KEYED
501 CONFIG_AUTOBOOT_PROMPT
502 CONFIG_AUTOBOOT_DELAY_STR
503 CONFIG_AUTOBOOT_STOP_STR
504 CONFIG_AUTOBOOT_DELAY_STR2
505 CONFIG_AUTOBOOT_STOP_STR2
506 CONFIG_ZERO_BOOTDELAY_CHECK
507 CONFIG_RESET_TO_RETRY
511 Only needed when CONFIG_BOOTDELAY is enabled;
512 define a command string that is automatically executed
513 when no character is read on the console interface
514 within "Boot Delay" after reset.
517 This can be used to pass arguments to the bootm
518 command. The value of CONFIG_BOOTARGS goes into the
519 environment value "bootargs".
521 CONFIG_RAMBOOT and CONFIG_NFSBOOT
522 The value of these goes into the environment as
523 "ramboot" and "nfsboot" respectively, and can be used
524 as a convenience, when switching between booting from
530 When this option is #defined, the existence of the
531 environment variable "preboot" will be checked
532 immediately before starting the CONFIG_BOOTDELAY
533 countdown and/or running the auto-boot command resp.
534 entering interactive mode.
536 This feature is especially useful when "preboot" is
537 automatically generated or modified. For an example
538 see the LWMON board specific code: here "preboot" is
539 modified when the user holds down a certain
540 combination of keys on the (special) keyboard when
543 - Serial Download Echo Mode:
545 If defined to 1, all characters received during a
546 serial download (using the "loads" command) are
547 echoed back. This might be needed by some terminal
548 emulations (like "cu"), but may as well just take
549 time on others. This setting #define's the initial
550 value of the "loads_echo" environment variable.
552 - Kgdb Serial Baudrate: (if CONFIG_CMD_KGDB is defined)
554 Select one of the baudrates listed in
555 CFG_BAUDRATE_TABLE, see below.
558 Monitor commands can be included or excluded
559 from the build by using the #include files
560 "config_cmd_all.h" and #undef'ing unwanted
561 commands, or using "config_cmd_default.h"
562 and augmenting with additional #define's
565 The default command configuration includes all commands
566 except those marked below with a "*".
568 CONFIG_CMD_ASKENV * ask for env variable
569 CONFIG_CMD_AUTOSCRIPT Autoscript Support
570 CONFIG_CMD_BDI bdinfo
571 CONFIG_CMD_BEDBUG * Include BedBug Debugger
572 CONFIG_CMD_BMP * BMP support
573 CONFIG_CMD_BSP * Board specific commands
574 CONFIG_CMD_BOOTD bootd
575 CONFIG_CMD_CACHE * icache, dcache
576 CONFIG_CMD_CONSOLE coninfo
577 CONFIG_CMD_DATE * support for RTC, date/time...
578 CONFIG_CMD_DHCP * DHCP support
579 CONFIG_CMD_DIAG * Diagnostics
580 CONFIG_CMD_DOC * Disk-On-Chip Support
581 CONFIG_CMD_DTT * Digital Therm and Thermostat
582 CONFIG_CMD_ECHO echo arguments
583 CONFIG_CMD_EEPROM * EEPROM read/write support
584 CONFIG_CMD_ELF * bootelf, bootvx
585 CONFIG_CMD_ENV saveenv
586 CONFIG_CMD_FDC * Floppy Disk Support
587 CONFIG_CMD_FAT * FAT partition support
588 CONFIG_CMD_FDOS * Dos diskette Support
589 CONFIG_CMD_FLASH flinfo, erase, protect
590 CONFIG_CMD_FPGA FPGA device initialization support
591 CONFIG_CMD_HWFLOW * RTS/CTS hw flow control
592 CONFIG_CMD_I2C * I2C serial bus support
593 CONFIG_CMD_IDE * IDE harddisk support
594 CONFIG_CMD_IMI iminfo
595 CONFIG_CMD_IMLS List all found images
596 CONFIG_CMD_IMMAP * IMMR dump support
597 CONFIG_CMD_IRQ * irqinfo
598 CONFIG_CMD_ITEST Integer/string test of 2 values
599 CONFIG_CMD_JFFS2 * JFFS2 Support
600 CONFIG_CMD_KGDB * kgdb
601 CONFIG_CMD_LOADB loadb
602 CONFIG_CMD_LOADS loads
603 CONFIG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base,
605 CONFIG_CMD_MISC Misc functions like sleep etc
606 CONFIG_CMD_MMC * MMC memory mapped support
607 CONFIG_CMD_MII * MII utility commands
608 CONFIG_CMD_NAND * NAND support
609 CONFIG_CMD_NET bootp, tftpboot, rarpboot
610 CONFIG_CMD_PCI * pciinfo
611 CONFIG_CMD_PCMCIA * PCMCIA support
612 CONFIG_CMD_PING * send ICMP ECHO_REQUEST to network
614 CONFIG_CMD_PORTIO * Port I/O
615 CONFIG_CMD_REGINFO * Register dump
616 CONFIG_CMD_RUN run command in env variable
617 CONFIG_CMD_SAVES * save S record dump
618 CONFIG_CMD_SCSI * SCSI Support
619 CONFIG_CMD_SDRAM * print SDRAM configuration information
620 (requires CONFIG_CMD_I2C)
621 CONFIG_CMD_SETGETDCR Support for DCR Register access
623 CONFIG_CMD_SPI * SPI serial bus support
624 CONFIG_CMD_USB * USB support
625 CONFIG_CMD_VFD * VFD support (TRAB)
626 CONFIG_CMD_BSP * Board SPecific functions
627 CONFIG_CMD_CDP * Cisco Discover Protocol support
628 CONFIG_CMD_FSL * Microblaze FSL support
631 EXAMPLE: If you want all functions except of network
632 support you can write:
634 #include "config_cmd_all.h"
635 #undef CONFIG_CMD_NET
638 fdt (flattened device tree) command: CONFIG_OF_LIBFDT
640 Note: Don't enable the "icache" and "dcache" commands
641 (configuration option CONFIG_CMD_CACHE) unless you know
642 what you (and your U-Boot users) are doing. Data
643 cache cannot be enabled on systems like the 8xx or
644 8260 (where accesses to the IMMR region must be
645 uncached), and it cannot be disabled on all other
646 systems where we (mis-) use the data cache to hold an
647 initial stack and some data.
650 XXX - this list needs to get updated!
654 If this variable is defined, it enables watchdog
655 support. There must be support in the platform specific
656 code for a watchdog. For the 8xx and 8260 CPUs, the
657 SIU Watchdog feature is enabled in the SYPCR
661 CONFIG_VERSION_VARIABLE
662 If this variable is defined, an environment variable
663 named "ver" is created by U-Boot showing the U-Boot
664 version as printed by the "version" command.
665 This variable is readonly.
669 When CONFIG_CMD_DATE is selected, the type of the RTC
670 has to be selected, too. Define exactly one of the
673 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx
674 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC
675 CONFIG_RTC_MC146818 - use MC146818 RTC
676 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC
677 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC
678 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC
679 CONFIG_RTC_DS164x - use Dallas DS164x RTC
680 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC
681 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC
682 CFG_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337
684 Note that if the RTC uses I2C, then the I2C interface
685 must also be configured. See I2C Support, below.
689 When CONFIG_TIMESTAMP is selected, the timestamp
690 (date and time) of an image is printed by image
691 commands like bootm or iminfo. This option is
692 automatically enabled when you select CONFIG_CMD_DATE .
695 CONFIG_MAC_PARTITION and/or CONFIG_DOS_PARTITION
696 and/or CONFIG_ISO_PARTITION
698 If IDE or SCSI support is enabled (CONFIG_CMD_IDE or
699 CONFIG_CMD_SCSI) you must configure support for at
700 least one partition type as well.
703 CONFIG_IDE_RESET_ROUTINE - this is defined in several
704 board configurations files but used nowhere!
706 CONFIG_IDE_RESET - is this is defined, IDE Reset will
707 be performed by calling the function
708 ide_set_reset(int reset)
709 which has to be defined in a board specific file
714 Set this to enable ATAPI support.
719 Set this to enable support for disks larger than 137GB
720 Also look at CFG_64BIT_LBA ,CFG_64BIT_VSPRINTF and CFG_64BIT_STRTOUL
721 Whithout these , LBA48 support uses 32bit variables and will 'only'
722 support disks up to 2.1TB.
725 When enabled, makes the IDE subsystem use 64bit sector addresses.
729 At the moment only there is only support for the
730 SYM53C8XX SCSI controller; define
731 CONFIG_SCSI_SYM53C8XX to enable it.
733 CFG_SCSI_MAX_LUN [8], CFG_SCSI_MAX_SCSI_ID [7] and
734 CFG_SCSI_MAX_DEVICE [CFG_SCSI_MAX_SCSI_ID *
735 CFG_SCSI_MAX_LUN] can be adjusted to define the
736 maximum numbers of LUNs, SCSI ID's and target
738 CFG_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz)
740 - NETWORK Support (PCI):
742 Support for Intel 8254x gigabit chips.
744 CONFIG_E1000_FALLBACK_MAC
745 default MAC for empty eeprom after production.
748 Support for Intel 82557/82559/82559ER chips.
749 Optional CONFIG_EEPRO100_SROM_WRITE enables eeprom
750 write routine for first time initialisation.
753 Support for Digital 2114x chips.
754 Optional CONFIG_TULIP_SELECT_MEDIA for board specific
755 modem chip initialisation (KS8761/QS6611).
758 Support for National dp83815 chips.
761 Support for National dp8382[01] gigabit chips.
763 - NETWORK Support (other):
765 CONFIG_DRIVER_LAN91C96
766 Support for SMSC's LAN91C96 chips.
769 Define this to hold the physical address
770 of the LAN91C96's I/O space
772 CONFIG_LAN91C96_USE_32_BIT
773 Define this to enable 32 bit addressing
775 CONFIG_DRIVER_SMC91111
776 Support for SMSC's LAN91C111 chip
779 Define this to hold the physical address
780 of the device (I/O space)
782 CONFIG_SMC_USE_32_BIT
783 Define this if data bus is 32 bits
785 CONFIG_SMC_USE_IOFUNCS
786 Define this to use i/o functions instead of macros
787 (some hardware wont work with macros)
790 At the moment only the UHCI host controller is
791 supported (PIP405, MIP405, MPC5200); define
792 CONFIG_USB_UHCI to enable it.
793 define CONFIG_USB_KEYBOARD to enable the USB Keyboard
794 and define CONFIG_USB_STORAGE to enable the USB
797 Supported are USB Keyboards and USB Floppy drives
799 MPC5200 USB requires additional defines:
801 for 528 MHz Clock: 0x0001bbbb
803 for differential drivers: 0x00001000
804 for single ended drivers: 0x00005000
806 May be defined to allow interrupt polling
807 instead of using asynchronous interrupts
810 Define the below if you wish to use the USB console.
811 Once firmware is rebuilt from a serial console issue the
812 command "setenv stdin usbtty; setenv stdout usbtty" and
813 attach your usb cable. The Unix command "dmesg" should print
814 it has found a new device. The environment variable usbtty
815 can be set to gserial or cdc_acm to enable your device to
816 appear to a USB host as a Linux gserial device or a
817 Common Device Class Abstract Control Model serial device.
818 If you select usbtty = gserial you should be able to enumerate
820 # modprobe usbserial vendor=0xVendorID product=0xProductID
821 else if using cdc_acm, simply setting the environment
822 variable usbtty to be cdc_acm should suffice. The following
823 might be defined in YourBoardName.h
826 Define this to build a UDC device
829 Define this to have a tty type of device available to
830 talk to the UDC device
832 CFG_CONSOLE_IS_IN_ENV
833 Define this if you want stdin, stdout &/or stderr to
837 CFG_USB_EXTC_CLK 0xBLAH
838 Derive USB clock from external clock "blah"
839 - CFG_USB_EXTC_CLK 0x02
841 CFG_USB_BRG_CLK 0xBLAH
842 Derive USB clock from brgclk
843 - CFG_USB_BRG_CLK 0x04
845 If you have a USB-IF assigned VendorID then you may wish to
846 define your own vendor specific values either in BoardName.h
847 or directly in usbd_vendor_info.h. If you don't define
848 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME,
849 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot
850 should pretend to be a Linux device to it's target host.
852 CONFIG_USBD_MANUFACTURER
853 Define this string as the name of your company for
854 - CONFIG_USBD_MANUFACTURER "my company"
856 CONFIG_USBD_PRODUCT_NAME
857 Define this string as the name of your product
858 - CONFIG_USBD_PRODUCT_NAME "acme usb device"
861 Define this as your assigned Vendor ID from the USB
862 Implementors Forum. This *must* be a genuine Vendor ID
863 to avoid polluting the USB namespace.
864 - CONFIG_USBD_VENDORID 0xFFFF
866 CONFIG_USBD_PRODUCTID
867 Define this as the unique Product ID
869 - CONFIG_USBD_PRODUCTID 0xFFFF
873 The MMC controller on the Intel PXA is supported. To
874 enable this define CONFIG_MMC. The MMC can be
875 accessed from the boot prompt by mapping the device
876 to physical memory similar to flash. Command line is
877 enabled with CONFIG_CMD_MMC. The MMC driver also works with
878 the FAT fs. This is enabled with CONFIG_CMD_FAT.
880 - Journaling Flash filesystem support:
881 CONFIG_JFFS2_NAND, CONFIG_JFFS2_NAND_OFF, CONFIG_JFFS2_NAND_SIZE,
882 CONFIG_JFFS2_NAND_DEV
883 Define these for a default partition on a NAND device
885 CFG_JFFS2_FIRST_SECTOR,
886 CFG_JFFS2_FIRST_BANK, CFG_JFFS2_NUM_BANKS
887 Define these for a default partition on a NOR device
890 Define this to create an own partition. You have to provide a
891 function struct part_info* jffs2_part_info(int part_num)
893 If you define only one JFFS2 partition you may also want to
894 #define CFG_JFFS_SINGLE_PART 1
895 to disable the command chpart. This is the default when you
896 have not defined a custom partition
901 Define this to enable standard (PC-Style) keyboard
905 Standard PC keyboard driver with US (is default) and
906 GERMAN key layout (switch via environment 'keymap=de') support.
907 Export function i8042_kbd_init, i8042_tstc and i8042_getc
908 for cfb_console. Supports cursor blinking.
913 Define this to enable video support (for output to
918 Enable Chips & Technologies 69000 Video chip
920 CONFIG_VIDEO_SMI_LYNXEM
921 Enable Silicon Motion SMI 712/710/810 Video chip. The
922 video output is selected via environment 'videoout'
923 (1 = LCD and 2 = CRT). If videoout is undefined, CRT is
926 For the CT69000 and SMI_LYNXEM drivers, videomode is
927 selected via environment 'videomode'. Two diferent ways
929 - "videomode=num" 'num' is a standard LiLo mode numbers.
930 Following standard modes are supported (* is default):
932 Colors 640x480 800x600 1024x768 1152x864 1280x1024
933 -------------+---------------------------------------------
934 8 bits | 0x301* 0x303 0x305 0x161 0x307
935 15 bits | 0x310 0x313 0x316 0x162 0x319
936 16 bits | 0x311 0x314 0x317 0x163 0x31A
937 24 bits | 0x312 0x315 0x318 ? 0x31B
938 -------------+---------------------------------------------
939 (i.e. setenv videomode 317; saveenv; reset;)
941 - "videomode=bootargs" all the video parameters are parsed
942 from the bootargs. (See drivers/video/videomodes.c)
945 CONFIG_VIDEO_SED13806
946 Enable Epson SED13806 driver. This driver supports 8bpp
947 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP
948 or CONFIG_VIDEO_SED13806_16BPP
953 Define this to enable a custom keyboard support.
954 This simply calls drv_keyboard_init() which must be
955 defined in your board-specific files.
956 The only board using this so far is RBC823.
958 - LCD Support: CONFIG_LCD
960 Define this to enable LCD support (for output to LCD
961 display); also select one of the supported displays
962 by defining one of these:
964 CONFIG_NEC_NL6448AC33:
966 NEC NL6448AC33-18. Active, color, single scan.
968 CONFIG_NEC_NL6448BC20
970 NEC NL6448BC20-08. 6.5", 640x480.
971 Active, color, single scan.
973 CONFIG_NEC_NL6448BC33_54
975 NEC NL6448BC33-54. 10.4", 640x480.
976 Active, color, single scan.
980 Sharp 320x240. Active, color, single scan.
981 It isn't 16x9, and I am not sure what it is.
983 CONFIG_SHARP_LQ64D341
985 Sharp LQ64D341 display, 640x480.
986 Active, color, single scan.
990 HLD1045 display, 640x480.
991 Active, color, single scan.
995 Optrex CBL50840-2 NF-FW 99 22 M5
997 Hitachi LMG6912RPFC-00T
1001 320x240. Black & white.
1003 Normally display is black on white background; define
1004 CFG_WHITE_ON_BLACK to get it inverted.
1006 - Splash Screen Support: CONFIG_SPLASH_SCREEN
1008 If this option is set, the environment is checked for
1009 a variable "splashimage". If found, the usual display
1010 of logo, copyright and system information on the LCD
1011 is suppressed and the BMP image at the address
1012 specified in "splashimage" is loaded instead. The
1013 console is redirected to the "nulldev", too. This
1014 allows for a "silent" boot where a splash screen is
1015 loaded very quickly after power-on.
1017 - Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP
1019 If this option is set, additionally to standard BMP
1020 images, gzipped BMP images can be displayed via the
1021 splashscreen support or the bmp command.
1023 - Compression support:
1026 If this option is set, support for bzip2 compressed
1027 images is included. If not, only uncompressed and gzip
1028 compressed images are supported.
1030 NOTE: the bzip2 algorithm requires a lot of RAM, so
1031 the malloc area (as defined by CFG_MALLOC_LEN) should
1037 The address of PHY on MII bus.
1039 CONFIG_PHY_CLOCK_FREQ (ppc4xx)
1041 The clock frequency of the MII bus
1045 If this option is set, support for speed/duplex
1046 detection of Gigabit PHY is included.
1048 CONFIG_PHY_RESET_DELAY
1050 Some PHY like Intel LXT971A need extra delay after
1051 reset before any MII register access is possible.
1052 For such PHY, set this option to the usec delay
1053 required. (minimum 300usec for LXT971A)
1055 CONFIG_PHY_CMD_DELAY (ppc4xx)
1057 Some PHY like Intel LXT971A need extra delay after
1058 command issued before MII status register can be read
1065 Define a default value for ethernet address to use
1066 for the respective ethernet interface, in case this
1067 is not determined automatically.
1072 Define a default value for the IP address to use for
1073 the default ethernet interface, in case this is not
1074 determined through e.g. bootp.
1076 - Server IP address:
1079 Defines a default value for theIP address of a TFTP
1080 server to contact when using the "tftboot" command.
1082 - Multicast TFTP Mode:
1085 Defines whether you want to support multicast TFTP as per
1086 rfc-2090; for example to work with atftp. Lets lots of targets
1087 tftp down the same boot image concurrently. Note: the ethernet
1088 driver in use must provide a function: mcast() to join/leave a
1091 CONFIG_BOOTP_RANDOM_DELAY
1092 - BOOTP Recovery Mode:
1093 CONFIG_BOOTP_RANDOM_DELAY
1095 If you have many targets in a network that try to
1096 boot using BOOTP, you may want to avoid that all
1097 systems send out BOOTP requests at precisely the same
1098 moment (which would happen for instance at recovery
1099 from a power failure, when all systems will try to
1100 boot, thus flooding the BOOTP server. Defining
1101 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
1102 inserted before sending out BOOTP requests. The
1103 following delays are inserted then:
1105 1st BOOTP request: delay 0 ... 1 sec
1106 2nd BOOTP request: delay 0 ... 2 sec
1107 3rd BOOTP request: delay 0 ... 4 sec
1109 BOOTP requests: delay 0 ... 8 sec
1111 - DHCP Advanced Options:
1112 You can fine tune the DHCP functionality by defining
1113 CONFIG_BOOTP_* symbols:
1115 CONFIG_BOOTP_SUBNETMASK
1116 CONFIG_BOOTP_GATEWAY
1117 CONFIG_BOOTP_HOSTNAME
1118 CONFIG_BOOTP_NISDOMAIN
1119 CONFIG_BOOTP_BOOTPATH
1120 CONFIG_BOOTP_BOOTFILESIZE
1123 CONFIG_BOOTP_SEND_HOSTNAME
1124 CONFIG_BOOTP_NTPSERVER
1125 CONFIG_BOOTP_TIMEOFFSET
1126 CONFIG_BOOTP_VENDOREX
1128 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip
1129 environment variable, not the BOOTP server.
1131 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS
1132 serverip from a DHCP server, it is possible that more
1133 than one DNS serverip is offered to the client.
1134 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS
1135 serverip will be stored in the additional environment
1136 variable "dnsip2". The first DNS serverip is always
1137 stored in the variable "dnsip", when CONFIG_BOOTP_DNS
1140 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable
1141 to do a dynamic update of a DNS server. To do this, they
1142 need the hostname of the DHCP requester.
1143 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content
1144 of the "hostname" environment variable is passed as
1145 option 12 to the DHCP server.
1147 CONFIG_BOOTP_DHCP_REQUEST_DELAY
1149 A 32bit value in microseconds for a delay between
1150 receiving a "DHCP Offer" and sending the "DHCP Request".
1151 This fixes a problem with certain DHCP servers that don't
1152 respond 100% of the time to a "DHCP request". E.g. On an
1153 AT91RM9200 processor running at 180MHz, this delay needed
1154 to be *at least* 15,000 usec before a Windows Server 2003
1155 DHCP server would reply 100% of the time. I recommend at
1156 least 50,000 usec to be safe. The alternative is to hope
1157 that one of the retries will be successful but note that
1158 the DHCP timeout and retry process takes a longer than
1162 CONFIG_CDP_DEVICE_ID
1164 The device id used in CDP trigger frames.
1166 CONFIG_CDP_DEVICE_ID_PREFIX
1168 A two character string which is prefixed to the MAC address
1173 A printf format string which contains the ascii name of
1174 the port. Normally is set to "eth%d" which sets
1175 eth0 for the first ethernet, eth1 for the second etc.
1177 CONFIG_CDP_CAPABILITIES
1179 A 32bit integer which indicates the device capabilities;
1180 0x00000010 for a normal host which does not forwards.
1184 An ascii string containing the version of the software.
1188 An ascii string containing the name of the platform.
1192 A 32bit integer sent on the trigger.
1194 CONFIG_CDP_POWER_CONSUMPTION
1196 A 16bit integer containing the power consumption of the
1197 device in .1 of milliwatts.
1199 CONFIG_CDP_APPLIANCE_VLAN_TYPE
1201 A byte containing the id of the VLAN.
1203 - Status LED: CONFIG_STATUS_LED
1205 Several configurations allow to display the current
1206 status using a LED. For instance, the LED will blink
1207 fast while running U-Boot code, stop blinking as
1208 soon as a reply to a BOOTP request was received, and
1209 start blinking slow once the Linux kernel is running
1210 (supported by a status LED driver in the Linux
1211 kernel). Defining CONFIG_STATUS_LED enables this
1214 - CAN Support: CONFIG_CAN_DRIVER
1216 Defining CONFIG_CAN_DRIVER enables CAN driver support
1217 on those systems that support this (optional)
1218 feature, like the TQM8xxL modules.
1220 - I2C Support: CONFIG_HARD_I2C | CONFIG_SOFT_I2C
1222 These enable I2C serial bus commands. Defining either of
1223 (but not both of) CONFIG_HARD_I2C or CONFIG_SOFT_I2C will
1224 include the appropriate I2C driver for the selected cpu.
1226 This will allow you to use i2c commands at the u-boot
1227 command line (as long as you set CONFIG_CMD_I2C in
1228 CONFIG_COMMANDS) and communicate with i2c based realtime
1229 clock chips. See common/cmd_i2c.c for a description of the
1230 command line interface.
1232 CONFIG_I2C_CMD_TREE is a recommended option that places
1233 all I2C commands under a single 'i2c' root command. The
1234 older 'imm', 'imd', 'iprobe' etc. commands are considered
1235 deprecated and may disappear in the future.
1237 CONFIG_HARD_I2C selects a hardware I2C controller.
1239 CONFIG_SOFT_I2C configures u-boot to use a software (aka
1240 bit-banging) driver instead of CPM or similar hardware
1243 There are several other quantities that must also be
1244 defined when you define CONFIG_HARD_I2C or CONFIG_SOFT_I2C.
1246 In both cases you will need to define CFG_I2C_SPEED
1247 to be the frequency (in Hz) at which you wish your i2c bus
1248 to run and CFG_I2C_SLAVE to be the address of this node (ie
1249 the cpu's i2c node address).
1251 Now, the u-boot i2c code for the mpc8xx (cpu/mpc8xx/i2c.c)
1252 sets the cpu up as a master node and so its address should
1253 therefore be cleared to 0 (See, eg, MPC823e User's Manual
1254 p.16-473). So, set CFG_I2C_SLAVE to 0.
1256 That's all that's required for CONFIG_HARD_I2C.
1258 If you use the software i2c interface (CONFIG_SOFT_I2C)
1259 then the following macros need to be defined (examples are
1260 from include/configs/lwmon.h):
1264 (Optional). Any commands necessary to enable the I2C
1265 controller or configure ports.
1267 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
1271 (Only for MPC8260 CPU). The I/O port to use (the code
1272 assumes both bits are on the same port). Valid values
1273 are 0..3 for ports A..D.
1277 The code necessary to make the I2C data line active
1278 (driven). If the data line is open collector, this
1281 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
1285 The code necessary to make the I2C data line tri-stated
1286 (inactive). If the data line is open collector, this
1289 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
1293 Code that returns TRUE if the I2C data line is high,
1296 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
1300 If <bit> is TRUE, sets the I2C data line high. If it
1301 is FALSE, it clears it (low).
1303 eg: #define I2C_SDA(bit) \
1304 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
1305 else immr->im_cpm.cp_pbdat &= ~PB_SDA
1309 If <bit> is TRUE, sets the I2C clock line high. If it
1310 is FALSE, it clears it (low).
1312 eg: #define I2C_SCL(bit) \
1313 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
1314 else immr->im_cpm.cp_pbdat &= ~PB_SCL
1318 This delay is invoked four times per clock cycle so this
1319 controls the rate of data transfer. The data rate thus
1320 is 1 / (I2C_DELAY * 4). Often defined to be something
1323 #define I2C_DELAY udelay(2)
1327 When a board is reset during an i2c bus transfer
1328 chips might think that the current transfer is still
1329 in progress. On some boards it is possible to access
1330 the i2c SCLK line directly, either by using the
1331 processor pin as a GPIO or by having a second pin
1332 connected to the bus. If this option is defined a
1333 custom i2c_init_board() routine in boards/xxx/board.c
1334 is run early in the boot sequence.
1336 CONFIG_I2CFAST (PPC405GP|PPC405EP only)
1338 This option enables configuration of bi_iic_fast[] flags
1339 in u-boot bd_info structure based on u-boot environment
1340 variable "i2cfast". (see also i2cfast)
1342 CONFIG_I2C_MULTI_BUS
1344 This option allows the use of multiple I2C buses, each of which
1345 must have a controller. At any point in time, only one bus is
1346 active. To switch to a different bus, use the 'i2c dev' command.
1347 Note that bus numbering is zero-based.
1351 This option specifies a list of I2C devices that will be skipped
1352 when the 'i2c probe' command is issued (or 'iprobe' using the legacy
1353 command). If CONFIG_I2C_MULTI_BUS is set, specify a list of bus-device
1354 pairs. Otherwise, specify a 1D array of device addresses
1357 #undef CONFIG_I2C_MULTI_BUS
1358 #define CFG_I2C_NOPROBES {0x50,0x68}
1360 will skip addresses 0x50 and 0x68 on a board with one I2C bus
1362 #define CONFIG_I2C_MULTI_BUS
1363 #define CFG_I2C_MULTI_NOPROBES {{0,0x50},{0,0x68},{1,0x54}}
1365 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1
1369 If defined, then this indicates the I2C bus number for DDR SPD.
1370 If not defined, then U-Boot assumes that SPD is on I2C bus 0.
1374 If defined, then this indicates the I2C bus number for the RTC.
1375 If not defined, then U-Boot assumes that RTC is on I2C bus 0.
1379 If defined, then this indicates the I2C bus number for the DTT.
1380 If not defined, then U-Boot assumes that DTT is on I2C bus 0.
1384 Define this option if you want to use Freescale's I2C driver in
1385 drivers/i2c/fsl_i2c.c.
1388 - SPI Support: CONFIG_SPI
1390 Enables SPI driver (so far only tested with
1391 SPI EEPROM, also an instance works with Crystal A/D and
1392 D/As on the SACSng board)
1396 Enables extended (16-bit) SPI EEPROM addressing.
1397 (symmetrical to CONFIG_I2C_X)
1401 Enables a software (bit-bang) SPI driver rather than
1402 using hardware support. This is a general purpose
1403 driver that only requires three general I/O port pins
1404 (two outputs, one input) to function. If this is
1405 defined, the board configuration must define several
1406 SPI configuration items (port pins to use, etc). For
1407 an example, see include/configs/sacsng.h.
1411 Enables a hardware SPI driver for general-purpose reads
1412 and writes. As with CONFIG_SOFT_SPI, the board configuration
1413 must define a list of chip-select function pointers.
1414 Currently supported on some MPC8xxx processors. For an
1415 example, see include/configs/mpc8349emds.h.
1417 - FPGA Support: CONFIG_FPGA
1419 Enables FPGA subsystem.
1421 CONFIG_FPGA_<vendor>
1423 Enables support for specific chip vendors.
1426 CONFIG_FPGA_<family>
1428 Enables support for FPGA family.
1429 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX)
1433 Specify the number of FPGA devices to support.
1435 CFG_FPGA_PROG_FEEDBACK
1437 Enable printing of hash marks during FPGA configuration.
1441 Enable checks on FPGA configuration interface busy
1442 status by the configuration function. This option
1443 will require a board or device specific function to
1448 If defined, a function that provides delays in the FPGA
1449 configuration driver.
1451 CFG_FPGA_CHECK_CTRLC
1452 Allow Control-C to interrupt FPGA configuration
1454 CFG_FPGA_CHECK_ERROR
1456 Check for configuration errors during FPGA bitfile
1457 loading. For example, abort during Virtex II
1458 configuration if the INIT_B line goes low (which
1459 indicated a CRC error).
1463 Maximum time to wait for the INIT_B line to deassert
1464 after PROB_B has been deasserted during a Virtex II
1465 FPGA configuration sequence. The default time is 500
1470 Maximum time to wait for BUSY to deassert during
1471 Virtex II FPGA configuration. The default is 5 mS.
1473 CFG_FPGA_WAIT_CONFIG
1475 Time to wait after FPGA configuration. The default is
1478 - Configuration Management:
1481 If defined, this string will be added to the U-Boot
1482 version information (U_BOOT_VERSION)
1484 - Vendor Parameter Protection:
1486 U-Boot considers the values of the environment
1487 variables "serial#" (Board Serial Number) and
1488 "ethaddr" (Ethernet Address) to be parameters that
1489 are set once by the board vendor / manufacturer, and
1490 protects these variables from casual modification by
1491 the user. Once set, these variables are read-only,
1492 and write or delete attempts are rejected. You can
1493 change this behviour:
1495 If CONFIG_ENV_OVERWRITE is #defined in your config
1496 file, the write protection for vendor parameters is
1497 completely disabled. Anybody can change or delete
1500 Alternatively, if you #define _both_ CONFIG_ETHADDR
1501 _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
1502 ethernet address is installed in the environment,
1503 which can be changed exactly ONCE by the user. [The
1504 serial# is unaffected by this, i. e. it remains
1510 Define this variable to enable the reservation of
1511 "protected RAM", i. e. RAM which is not overwritten
1512 by U-Boot. Define CONFIG_PRAM to hold the number of
1513 kB you want to reserve for pRAM. You can overwrite
1514 this default value by defining an environment
1515 variable "pram" to the number of kB you want to
1516 reserve. Note that the board info structure will
1517 still show the full amount of RAM. If pRAM is
1518 reserved, a new environment variable "mem" will
1519 automatically be defined to hold the amount of
1520 remaining RAM in a form that can be passed as boot
1521 argument to Linux, for instance like that:
1523 setenv bootargs ... mem=\${mem}
1526 This way you can tell Linux not to use this memory,
1527 either, which results in a memory region that will
1528 not be affected by reboots.
1530 *WARNING* If your board configuration uses automatic
1531 detection of the RAM size, you must make sure that
1532 this memory test is non-destructive. So far, the
1533 following board configurations are known to be
1536 ETX094, IVMS8, IVML24, SPD8xx, TQM8xxL,
1537 HERMES, IP860, RPXlite, LWMON, LANTEC,
1538 PCU_E, FLAGADM, TQM8260
1543 Define this variable to stop the system in case of a
1544 fatal error, so that you have to reset it manually.
1545 This is probably NOT a good idea for an embedded
1546 system where you want to system to reboot
1547 automatically as fast as possible, but it may be
1548 useful during development since you can try to debug
1549 the conditions that lead to the situation.
1551 CONFIG_NET_RETRY_COUNT
1553 This variable defines the number of retries for
1554 network operations like ARP, RARP, TFTP, or BOOTP
1555 before giving up the operation. If not defined, a
1556 default value of 5 is used.
1558 - Command Interpreter:
1559 CONFIG_AUTO_COMPLETE
1561 Enable auto completion of commands using TAB.
1563 Note that this feature has NOT been implemented yet
1564 for the "hush" shell.
1569 Define this variable to enable the "hush" shell (from
1570 Busybox) as command line interpreter, thus enabling
1571 powerful command line syntax like
1572 if...then...else...fi conditionals or `&&' and '||'
1573 constructs ("shell scripts").
1575 If undefined, you get the old, much simpler behaviour
1576 with a somewhat smaller memory footprint.
1581 This defines the secondary prompt string, which is
1582 printed when the command interpreter needs more input
1583 to complete a command. Usually "> ".
1587 In the current implementation, the local variables
1588 space and global environment variables space are
1589 separated. Local variables are those you define by
1590 simply typing `name=value'. To access a local
1591 variable later on, you have write `$name' or
1592 `${name}'; to execute the contents of a variable
1593 directly type `$name' at the command prompt.
1595 Global environment variables are those you use
1596 setenv/printenv to work with. To run a command stored
1597 in such a variable, you need to use the run command,
1598 and you must not use the '$' sign to access them.
1600 To store commands and special characters in a
1601 variable, please use double quotation marks
1602 surrounding the whole text of the variable, instead
1603 of the backslashes before semicolons and special
1606 - Commandline Editing and History:
1607 CONFIG_CMDLINE_EDITING
1609 Enable editiong and History functions for interactive
1610 commandline input operations
1612 - Default Environment:
1613 CONFIG_EXTRA_ENV_SETTINGS
1615 Define this to contain any number of null terminated
1616 strings (variable = value pairs) that will be part of
1617 the default environment compiled into the boot image.
1619 For example, place something like this in your
1620 board's config file:
1622 #define CONFIG_EXTRA_ENV_SETTINGS \
1626 Warning: This method is based on knowledge about the
1627 internal format how the environment is stored by the
1628 U-Boot code. This is NOT an official, exported
1629 interface! Although it is unlikely that this format
1630 will change soon, there is no guarantee either.
1631 You better know what you are doing here.
1633 Note: overly (ab)use of the default environment is
1634 discouraged. Make sure to check other ways to preset
1635 the environment like the autoscript function or the
1638 - DataFlash Support:
1639 CONFIG_HAS_DATAFLASH
1641 Defining this option enables DataFlash features and
1642 allows to read/write in Dataflash via the standard
1645 - SystemACE Support:
1648 Adding this option adds support for Xilinx SystemACE
1649 chips attached via some sort of local bus. The address
1650 of the chip must alsh be defined in the
1651 CFG_SYSTEMACE_BASE macro. For example:
1653 #define CONFIG_SYSTEMACE
1654 #define CFG_SYSTEMACE_BASE 0xf0000000
1656 When SystemACE support is added, the "ace" device type
1657 becomes available to the fat commands, i.e. fatls.
1659 - TFTP Fixed UDP Port:
1662 If this is defined, the environment variable tftpsrcp
1663 is used to supply the TFTP UDP source port value.
1664 If tftpsrcp isn't defined, the normal pseudo-random port
1665 number generator is used.
1667 Also, the environment variable tftpdstp is used to supply
1668 the TFTP UDP destination port value. If tftpdstp isn't
1669 defined, the normal port 69 is used.
1671 The purpose for tftpsrcp is to allow a TFTP server to
1672 blindly start the TFTP transfer using the pre-configured
1673 target IP address and UDP port. This has the effect of
1674 "punching through" the (Windows XP) firewall, allowing
1675 the remainder of the TFTP transfer to proceed normally.
1676 A better solution is to properly configure the firewall,
1677 but sometimes that is not allowed.
1679 - Show boot progress:
1680 CONFIG_SHOW_BOOT_PROGRESS
1682 Defining this option allows to add some board-
1683 specific code (calling a user-provided function
1684 "show_boot_progress(int)") that enables you to show
1685 the system's boot progress on some display (for
1686 example, some LED's) on your board. At the moment,
1687 the following checkpoints are implemented:
1689 Legacy uImage format:
1692 1 common/cmd_bootm.c before attempting to boot an image
1693 -1 common/cmd_bootm.c Image header has bad magic number
1694 2 common/cmd_bootm.c Image header has correct magic number
1695 -2 common/cmd_bootm.c Image header has bad checksum
1696 3 common/cmd_bootm.c Image header has correct checksum
1697 -3 common/cmd_bootm.c Image data has bad checksum
1698 4 common/cmd_bootm.c Image data has correct checksum
1699 -4 common/cmd_bootm.c Image is for unsupported architecture
1700 5 common/cmd_bootm.c Architecture check OK
1701 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi)
1702 6 common/cmd_bootm.c Image Type check OK
1703 -6 common/cmd_bootm.c gunzip uncompression error
1704 -7 common/cmd_bootm.c Unimplemented compression type
1705 7 common/cmd_bootm.c Uncompression OK
1706 8 common/cmd_bootm.c No uncompress/copy overwrite error
1707 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX)
1709 9 common/image.c Start initial ramdisk verification
1710 -10 common/image.c Ramdisk header has bad magic number
1711 -11 common/image.c Ramdisk header has bad checksum
1712 10 common/image.c Ramdisk header is OK
1713 -12 common/image.c Ramdisk data has bad checksum
1714 11 common/image.c Ramdisk data has correct checksum
1715 12 common/image.c Ramdisk verification complete, start loading
1716 -13 common/image.c Wrong Image Type (not PPC Linux Ramdisk)
1717 13 common/image.c Start multifile image verification
1718 14 common/image.c No initial ramdisk, no multifile, continue.
1720 15 lib_<arch>/bootm.c All preparation done, transferring control to OS
1722 -30 lib_ppc/board.c Fatal error, hang the system
1723 -31 post/post.c POST test failed, detected by post_output_backlog()
1724 -32 post/post.c POST test failed, detected by post_run_single()
1726 34 common/cmd_doc.c before loading a Image from a DOC device
1727 -35 common/cmd_doc.c Bad usage of "doc" command
1728 35 common/cmd_doc.c correct usage of "doc" command
1729 -36 common/cmd_doc.c No boot device
1730 36 common/cmd_doc.c correct boot device
1731 -37 common/cmd_doc.c Unknown Chip ID on boot device
1732 37 common/cmd_doc.c correct chip ID found, device available
1733 -38 common/cmd_doc.c Read Error on boot device
1734 38 common/cmd_doc.c reading Image header from DOC device OK
1735 -39 common/cmd_doc.c Image header has bad magic number
1736 39 common/cmd_doc.c Image header has correct magic number
1737 -40 common/cmd_doc.c Error reading Image from DOC device
1738 40 common/cmd_doc.c Image header has correct magic number
1739 41 common/cmd_ide.c before loading a Image from a IDE device
1740 -42 common/cmd_ide.c Bad usage of "ide" command
1741 42 common/cmd_ide.c correct usage of "ide" command
1742 -43 common/cmd_ide.c No boot device
1743 43 common/cmd_ide.c boot device found
1744 -44 common/cmd_ide.c Device not available
1745 44 common/cmd_ide.c Device available
1746 -45 common/cmd_ide.c wrong partition selected
1747 45 common/cmd_ide.c partition selected
1748 -46 common/cmd_ide.c Unknown partition table
1749 46 common/cmd_ide.c valid partition table found
1750 -47 common/cmd_ide.c Invalid partition type
1751 47 common/cmd_ide.c correct partition type
1752 -48 common/cmd_ide.c Error reading Image Header on boot device
1753 48 common/cmd_ide.c reading Image Header from IDE device OK
1754 -49 common/cmd_ide.c Image header has bad magic number
1755 49 common/cmd_ide.c Image header has correct magic number
1756 -50 common/cmd_ide.c Image header has bad checksum
1757 50 common/cmd_ide.c Image header has correct checksum
1758 -51 common/cmd_ide.c Error reading Image from IDE device
1759 51 common/cmd_ide.c reading Image from IDE device OK
1760 52 common/cmd_nand.c before loading a Image from a NAND device
1761 -53 common/cmd_nand.c Bad usage of "nand" command
1762 53 common/cmd_nand.c correct usage of "nand" command
1763 -54 common/cmd_nand.c No boot device
1764 54 common/cmd_nand.c boot device found
1765 -55 common/cmd_nand.c Unknown Chip ID on boot device
1766 55 common/cmd_nand.c correct chip ID found, device available
1767 -56 common/cmd_nand.c Error reading Image Header on boot device
1768 56 common/cmd_nand.c reading Image Header from NAND device OK
1769 -57 common/cmd_nand.c Image header has bad magic number
1770 57 common/cmd_nand.c Image header has correct magic number
1771 -58 common/cmd_nand.c Error reading Image from NAND device
1772 58 common/cmd_nand.c reading Image from NAND device OK
1774 -60 common/env_common.c Environment has a bad CRC, using default
1776 64 net/eth.c starting with Ethernetconfiguration.
1777 -64 net/eth.c no Ethernet found.
1778 65 net/eth.c Ethernet found.
1780 -80 common/cmd_net.c usage wrong
1781 80 common/cmd_net.c before calling NetLoop()
1782 -81 common/cmd_net.c some error in NetLoop() occured
1783 81 common/cmd_net.c NetLoop() back without error
1784 -82 common/cmd_net.c size == 0 (File with size 0 loaded)
1785 82 common/cmd_net.c trying automatic boot
1786 83 common/cmd_net.c running autoscript
1787 -83 common/cmd_net.c some error in automatic boot or autoscript
1788 84 common/cmd_net.c end without errors
1793 100 common/cmd_bootm.c Kernel FIT Image has correct format
1794 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format
1795 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration
1796 -101 common/cmd_bootm.c Can't get configuration for kernel subimage
1797 102 common/cmd_bootm.c Kernel unit name specified
1798 -103 common/cmd_bootm.c Can't get kernel subimage node offset
1799 103 common/cmd_bootm.c Found configuration node
1800 104 common/cmd_bootm.c Got kernel subimage node offset
1801 -104 common/cmd_bootm.c Kernel subimage hash verification failed
1802 105 common/cmd_bootm.c Kernel subimage hash verification OK
1803 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture
1804 106 common/cmd_bootm.c Architecture check OK
1805 -106 common/cmd_bootm.c Kernel subimage has wrong typea
1806 107 common/cmd_bootm.c Kernel subimge type OK
1807 -107 common/cmd_bootm.c Can't get kernel subimage data/size
1808 108 common/cmd_bootm.c Got kernel subimage data/size
1809 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT)
1810 -109 common/cmd_bootm.c Can't get kernel subimage type
1811 -110 common/cmd_bootm.c Can't get kernel subimage comp
1812 -111 common/cmd_bootm.c Can't get kernel subimage os
1813 -112 common/cmd_bootm.c Can't get kernel subimage load address
1814 -113 common/cmd_bootm.c Image uncompress/copy overwrite error
1816 120 common/image.c Start initial ramdisk verification
1817 -120 common/image.c Ramdisk FIT image has incorrect format
1818 121 common/image.c Ramdisk FIT image has correct format
1819 122 common/image.c No Ramdisk subimage unit name, using configuration
1820 -122 common/image.c Can't get configuration for ramdisk subimage
1821 123 common/image.c Ramdisk unit name specified
1822 -124 common/image.c Can't get ramdisk subimage node offset
1823 125 common/image.c Got ramdisk subimage node offset
1824 -125 common/image.c Ramdisk subimage hash verification failed
1825 126 common/image.c Ramdisk subimage hash verification OK
1826 -126 common/image.c Ramdisk subimage for unsupported architecture
1827 127 common/image.c Architecture check OK
1828 -127 common/image.c Can't get ramdisk subimage data/size
1829 128 common/image.c Got ramdisk subimage data/size
1830 129 common/image.c Can't get ramdisk load address
1831 -129 common/image.c Got ramdisk load address
1833 -130 common/cmd_doc.c Icorrect FIT image format
1834 131 common/cmd_doc.c FIT image format OK
1836 -140 common/cmd_ide.c Icorrect FIT image format
1837 141 common/cmd_ide.c FIT image format OK
1839 -150 common/cmd_nand.c Icorrect FIT image format
1840 151 common/cmd_nand.c FIT image format OK
1846 [so far only for SMDK2400 and TRAB boards]
1848 - Modem support endable:
1849 CONFIG_MODEM_SUPPORT
1851 - RTS/CTS Flow control enable:
1854 - Modem debug support:
1855 CONFIG_MODEM_SUPPORT_DEBUG
1857 Enables debugging stuff (char screen[1024], dbg())
1858 for modem support. Useful only with BDI2000.
1860 - Interrupt support (PPC):
1862 There are common interrupt_init() and timer_interrupt()
1863 for all PPC archs. interrupt_init() calls interrupt_init_cpu()
1864 for cpu specific initialization. interrupt_init_cpu()
1865 should set decrementer_count to appropriate value. If
1866 cpu resets decrementer automatically after interrupt
1867 (ppc4xx) it should set decrementer_count to zero.
1868 timer_interrupt() calls timer_interrupt_cpu() for cpu
1869 specific handling. If board has watchdog / status_led
1870 / other_activity_monitor it works automatically from
1871 general timer_interrupt().
1875 In the target system modem support is enabled when a
1876 specific key (key combination) is pressed during
1877 power-on. Otherwise U-Boot will boot normally
1878 (autoboot). The key_pressed() fuction is called from
1879 board_init(). Currently key_pressed() is a dummy
1880 function, returning 1 and thus enabling modem
1883 If there are no modem init strings in the
1884 environment, U-Boot proceed to autoboot; the
1885 previous output (banner, info printfs) will be
1888 See also: doc/README.Modem
1891 Configuration Settings:
1892 -----------------------
1894 - CFG_LONGHELP: Defined when you want long help messages included;
1895 undefine this when you're short of memory.
1897 - CFG_PROMPT: This is what U-Boot prints on the console to
1898 prompt for user input.
1900 - CFG_CBSIZE: Buffer size for input from the Console
1902 - CFG_PBSIZE: Buffer size for Console output
1904 - CFG_MAXARGS: max. Number of arguments accepted for monitor commands
1906 - CFG_BARGSIZE: Buffer size for Boot Arguments which are passed to
1907 the application (usually a Linux kernel) when it is
1910 - CFG_BAUDRATE_TABLE:
1911 List of legal baudrate settings for this board.
1913 - CFG_CONSOLE_INFO_QUIET
1914 Suppress display of console information at boot.
1916 - CFG_CONSOLE_IS_IN_ENV
1917 If the board specific function
1918 extern int overwrite_console (void);
1919 returns 1, the stdin, stderr and stdout are switched to the
1920 serial port, else the settings in the environment are used.
1922 - CFG_CONSOLE_OVERWRITE_ROUTINE
1923 Enable the call to overwrite_console().
1925 - CFG_CONSOLE_ENV_OVERWRITE
1926 Enable overwrite of previous console environment settings.
1928 - CFG_MEMTEST_START, CFG_MEMTEST_END:
1929 Begin and End addresses of the area used by the
1933 Enable an alternate, more extensive memory test.
1935 - CFG_MEMTEST_SCRATCH:
1936 Scratch address used by the alternate memory test
1937 You only need to set this if address zero isn't writeable
1939 - CFG_MEM_TOP_HIDE (PPC only):
1940 If CFG_MEM_TOP_HIDE is defined in the board config header,
1941 this specified memory area will get subtracted from the top
1942 (end) of ram and won't get "touched" at all by U-Boot. By
1943 fixing up gd->ram_size the Linux kernel should gets passed
1944 the now "corrected" memory size and won't touch it either.
1945 This should work for arch/ppc and arch/powerpc. Only Linux
1946 board ports in arch/powerpc with bootwrapper support that
1947 recalculate the memory size from the SDRAM controller setup
1948 will have to get fixed in Linux additionally.
1950 This option can be used as a workaround for the 440EPx/GRx
1951 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't
1954 WARNING: Please make sure that this value is a multiple of
1955 the Linux page size (normally 4k). If this is not the case,
1956 then the end address of the Linux memory will be located at a
1957 non page size aligned address and this could cause major
1960 - CFG_TFTP_LOADADDR:
1961 Default load address for network file downloads
1963 - CFG_LOADS_BAUD_CHANGE:
1964 Enable temporary baudrate change while serial download
1967 Physical start address of SDRAM. _Must_ be 0 here.
1970 Physical start address of Motherboard I/O (if using a
1974 Physical start address of Flash memory.
1977 Physical start address of boot monitor code (set by
1978 make config files to be same as the text base address
1979 (TEXT_BASE) used when linking) - same as
1980 CFG_FLASH_BASE when booting from flash.
1983 Size of memory reserved for monitor code, used to
1984 determine _at_compile_time_ (!) if the environment is
1985 embedded within the U-Boot image, or in a separate
1989 Size of DRAM reserved for malloc() use.
1992 Normally compressed uImages are limited to an
1993 uncompressed size of 8 MBytes. If this is not enough,
1994 you can define CFG_BOOTM_LEN in your board config file
1995 to adjust this setting to your needs.
1998 Maximum size of memory mapped by the startup code of
1999 the Linux kernel; all data that must be processed by
2000 the Linux kernel (bd_info, boot arguments, eventually
2001 initrd image) must be put below this limit.
2003 - CFG_MAX_FLASH_BANKS:
2004 Max number of Flash memory banks
2006 - CFG_MAX_FLASH_SECT:
2007 Max number of sectors on a Flash chip
2009 - CFG_FLASH_ERASE_TOUT:
2010 Timeout for Flash erase operations (in ms)
2012 - CFG_FLASH_WRITE_TOUT:
2013 Timeout for Flash write operations (in ms)
2015 - CFG_FLASH_LOCK_TOUT
2016 Timeout for Flash set sector lock bit operation (in ms)
2018 - CFG_FLASH_UNLOCK_TOUT
2019 Timeout for Flash clear lock bits operation (in ms)
2021 - CFG_FLASH_PROTECTION
2022 If defined, hardware flash sectors protection is used
2023 instead of U-Boot software protection.
2025 - CFG_DIRECT_FLASH_TFTP:
2027 Enable TFTP transfers directly to flash memory;
2028 without this option such a download has to be
2029 performed in two steps: (1) download to RAM, and (2)
2030 copy from RAM to flash.
2032 The two-step approach is usually more reliable, since
2033 you can check if the download worked before you erase
2034 the flash, but in some situations (when sytem RAM is
2035 too limited to allow for a tempory copy of the
2036 downloaded image) this option may be very useful.
2039 Define if the flash driver uses extra elements in the
2040 common flash structure for storing flash geometry.
2042 - CFG_FLASH_CFI_DRIVER
2043 This option also enables the building of the cfi_flash driver
2044 in the drivers directory
2046 - CFG_FLASH_USE_BUFFER_WRITE
2047 Use buffered writes to flash.
2049 - CONFIG_FLASH_SPANSION_S29WS_N
2050 s29ws-n MirrorBit flash has non-standard addresses for buffered
2053 - CFG_FLASH_QUIET_TEST
2054 If this option is defined, the common CFI flash doesn't
2055 print it's warning upon not recognized FLASH banks. This
2056 is useful, if some of the configured banks are only
2057 optionally available.
2059 - CONFIG_FLASH_SHOW_PROGRESS
2060 If defined (must be an integer), print out countdown
2061 digits and dots. Recommended value: 45 (9..1) for 80
2062 column displays, 15 (3..1) for 40 column displays.
2064 - CFG_RX_ETH_BUFFER:
2065 Defines the number of ethernet receive buffers. On some
2066 ethernet controllers it is recommended to set this value
2067 to 8 or even higher (EEPRO100 or 405 EMAC), since all
2068 buffers can be full shortly after enabling the interface
2069 on high ethernet traffic.
2070 Defaults to 4 if not defined.
2072 The following definitions that deal with the placement and management
2073 of environment data (variable area); in general, we support the
2074 following configurations:
2076 - CFG_ENV_IS_IN_FLASH:
2078 Define this if the environment is in flash memory.
2080 a) The environment occupies one whole flash sector, which is
2081 "embedded" in the text segment with the U-Boot code. This
2082 happens usually with "bottom boot sector" or "top boot
2083 sector" type flash chips, which have several smaller
2084 sectors at the start or the end. For instance, such a
2085 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In
2086 such a case you would place the environment in one of the
2087 4 kB sectors - with U-Boot code before and after it. With
2088 "top boot sector" type flash chips, you would put the
2089 environment in one of the last sectors, leaving a gap
2090 between U-Boot and the environment.
2094 Offset of environment data (variable area) to the
2095 beginning of flash memory; for instance, with bottom boot
2096 type flash chips the second sector can be used: the offset
2097 for this sector is given here.
2099 CFG_ENV_OFFSET is used relative to CFG_FLASH_BASE.
2103 This is just another way to specify the start address of
2104 the flash sector containing the environment (instead of
2107 - CFG_ENV_SECT_SIZE:
2109 Size of the sector containing the environment.
2112 b) Sometimes flash chips have few, equal sized, BIG sectors.
2113 In such a case you don't want to spend a whole sector for
2118 If you use this in combination with CFG_ENV_IS_IN_FLASH
2119 and CFG_ENV_SECT_SIZE, you can specify to use only a part
2120 of this flash sector for the environment. This saves
2121 memory for the RAM copy of the environment.
2123 It may also save flash memory if you decide to use this
2124 when your environment is "embedded" within U-Boot code,
2125 since then the remainder of the flash sector could be used
2126 for U-Boot code. It should be pointed out that this is
2127 STRONGLY DISCOURAGED from a robustness point of view:
2128 updating the environment in flash makes it always
2129 necessary to erase the WHOLE sector. If something goes
2130 wrong before the contents has been restored from a copy in
2131 RAM, your target system will be dead.
2133 - CFG_ENV_ADDR_REDUND
2136 These settings describe a second storage area used to hold
2137 a redundand copy of the environment data, so that there is
2138 a valid backup copy in case there is a power failure during
2139 a "saveenv" operation.
2141 BE CAREFUL! Any changes to the flash layout, and some changes to the
2142 source code will make it necessary to adapt <board>/u-boot.lds*
2146 - CFG_ENV_IS_IN_NVRAM:
2148 Define this if you have some non-volatile memory device
2149 (NVRAM, battery buffered SRAM) which you want to use for the
2155 These two #defines are used to determin the memory area you
2156 want to use for environment. It is assumed that this memory
2157 can just be read and written to, without any special
2160 BE CAREFUL! The first access to the environment happens quite early
2161 in U-Boot initalization (when we try to get the setting of for the
2162 console baudrate). You *MUST* have mappend your NVRAM area then, or
2165 Please note that even with NVRAM we still use a copy of the
2166 environment in RAM: we could work on NVRAM directly, but we want to
2167 keep settings there always unmodified except somebody uses "saveenv"
2168 to save the current settings.
2171 - CFG_ENV_IS_IN_EEPROM:
2173 Use this if you have an EEPROM or similar serial access
2174 device and a driver for it.
2179 These two #defines specify the offset and size of the
2180 environment area within the total memory of your EEPROM.
2182 - CFG_I2C_EEPROM_ADDR:
2183 If defined, specified the chip address of the EEPROM device.
2184 The default address is zero.
2186 - CFG_EEPROM_PAGE_WRITE_BITS:
2187 If defined, the number of bits used to address bytes in a
2188 single page in the EEPROM device. A 64 byte page, for example
2189 would require six bits.
2191 - CFG_EEPROM_PAGE_WRITE_DELAY_MS:
2192 If defined, the number of milliseconds to delay between
2193 page writes. The default is zero milliseconds.
2195 - CFG_I2C_EEPROM_ADDR_LEN:
2196 The length in bytes of the EEPROM memory array address. Note
2197 that this is NOT the chip address length!
2199 - CFG_I2C_EEPROM_ADDR_OVERFLOW:
2200 EEPROM chips that implement "address overflow" are ones
2201 like Catalyst 24WC04/08/16 which has 9/10/11 bits of
2202 address and the extra bits end up in the "chip address" bit
2203 slots. This makes a 24WC08 (1Kbyte) chip look like four 256
2206 Note that we consider the length of the address field to
2207 still be one byte because the extra address bits are hidden
2208 in the chip address.
2211 The size in bytes of the EEPROM device.
2214 - CFG_ENV_IS_IN_DATAFLASH:
2216 Define this if you have a DataFlash memory device which you
2217 want to use for the environment.
2223 These three #defines specify the offset and size of the
2224 environment area within the total memory of your DataFlash placed
2225 at the specified address.
2227 - CFG_ENV_IS_IN_NAND:
2229 Define this if you have a NAND device which you want to use
2230 for the environment.
2235 These two #defines specify the offset and size of the environment
2236 area within the first NAND device.
2238 - CFG_ENV_OFFSET_REDUND
2240 This setting describes a second storage area of CFG_ENV_SIZE
2241 size used to hold a redundant copy of the environment data,
2242 so that there is a valid backup copy in case there is a
2243 power failure during a "saveenv" operation.
2245 Note: CFG_ENV_OFFSET and CFG_ENV_OFFSET_REDUND must be aligned
2246 to a block boundary, and CFG_ENV_SIZE must be a multiple of
2247 the NAND devices block size.
2249 - CFG_SPI_INIT_OFFSET
2251 Defines offset to the initial SPI buffer area in DPRAM. The
2252 area is used at an early stage (ROM part) if the environment
2253 is configured to reside in the SPI EEPROM: We need a 520 byte
2254 scratch DPRAM area. It is used between the two initialization
2255 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems
2256 to be a good choice since it makes it far enough from the
2257 start of the data area as well as from the stack pointer.
2259 Please note that the environment is read-only until the monitor
2260 has been relocated to RAM and a RAM copy of the environment has been
2261 created; also, when using EEPROM you will have to use getenv_r()
2262 until then to read environment variables.
2264 The environment is protected by a CRC32 checksum. Before the monitor
2265 is relocated into RAM, as a result of a bad CRC you will be working
2266 with the compiled-in default environment - *silently*!!! [This is
2267 necessary, because the first environment variable we need is the
2268 "baudrate" setting for the console - if we have a bad CRC, we don't
2269 have any device yet where we could complain.]
2271 Note: once the monitor has been relocated, then it will complain if
2272 the default environment is used; a new CRC is computed as soon as you
2273 use the "saveenv" command to store a valid environment.
2275 - CFG_FAULT_ECHO_LINK_DOWN:
2276 Echo the inverted Ethernet link state to the fault LED.
2278 Note: If this option is active, then CFG_FAULT_MII_ADDR
2279 also needs to be defined.
2281 - CFG_FAULT_MII_ADDR:
2282 MII address of the PHY to check for the Ethernet link state.
2284 - CFG_64BIT_VSPRINTF:
2285 Makes vsprintf (and all *printf functions) support printing
2286 of 64bit values by using the L quantifier
2288 - CFG_64BIT_STRTOUL:
2289 Adds simple_strtoull that returns a 64bit value
2291 Low Level (hardware related) configuration options:
2292 ---------------------------------------------------
2294 - CFG_CACHELINE_SIZE:
2295 Cache Line Size of the CPU.
2298 Default address of the IMMR after system reset.
2300 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU,
2301 and RPXsuper) to be able to adjust the position of
2302 the IMMR register after a reset.
2304 - Floppy Disk Support:
2305 CFG_FDC_DRIVE_NUMBER
2307 the default drive number (default value 0)
2311 defines the spacing between fdc chipset registers
2316 defines the offset of register from address. It
2317 depends on which part of the data bus is connected to
2318 the fdc chipset. (default value 0)
2320 If CFG_ISA_IO_STRIDE CFG_ISA_IO_OFFSET and
2321 CFG_FDC_DRIVE_NUMBER are undefined, they take their
2324 if CFG_FDC_HW_INIT is defined, then the function
2325 fdc_hw_init() is called at the beginning of the FDC
2326 setup. fdc_hw_init() must be provided by the board
2327 source code. It is used to make hardware dependant
2330 - CFG_IMMR: Physical address of the Internal Memory.
2331 DO NOT CHANGE unless you know exactly what you're
2332 doing! (11-4) [MPC8xx/82xx systems only]
2334 - CFG_INIT_RAM_ADDR:
2336 Start address of memory area that can be used for
2337 initial data and stack; please note that this must be
2338 writable memory that is working WITHOUT special
2339 initialization, i. e. you CANNOT use normal RAM which
2340 will become available only after programming the
2341 memory controller and running certain initialization
2344 U-Boot uses the following memory types:
2345 - MPC8xx and MPC8260: IMMR (internal memory of the CPU)
2346 - MPC824X: data cache
2347 - PPC4xx: data cache
2349 - CFG_GBL_DATA_OFFSET:
2351 Offset of the initial data structure in the memory
2352 area defined by CFG_INIT_RAM_ADDR. Usually
2353 CFG_GBL_DATA_OFFSET is chosen such that the initial
2354 data is located at the end of the available space
2355 (sometimes written as (CFG_INIT_RAM_END -
2356 CFG_INIT_DATA_SIZE), and the initial stack is just
2357 below that area (growing from (CFG_INIT_RAM_ADDR +
2358 CFG_GBL_DATA_OFFSET) downward.
2361 On the MPC824X (or other systems that use the data
2362 cache for initial memory) the address chosen for
2363 CFG_INIT_RAM_ADDR is basically arbitrary - it must
2364 point to an otherwise UNUSED address space between
2365 the top of RAM and the start of the PCI space.
2367 - CFG_SIUMCR: SIU Module Configuration (11-6)
2369 - CFG_SYPCR: System Protection Control (11-9)
2371 - CFG_TBSCR: Time Base Status and Control (11-26)
2373 - CFG_PISCR: Periodic Interrupt Status and Control (11-31)
2375 - CFG_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30)
2377 - CFG_SCCR: System Clock and reset Control Register (15-27)
2379 - CFG_OR_TIMING_SDRAM:
2383 periodic timer for refresh
2385 - CFG_DER: Debug Event Register (37-47)
2387 - FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CFG_REMAP_OR_AM,
2388 CFG_PRELIM_OR_AM, CFG_OR_TIMING_FLASH, CFG_OR0_REMAP,
2389 CFG_OR0_PRELIM, CFG_BR0_PRELIM, CFG_OR1_REMAP, CFG_OR1_PRELIM,
2391 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
2393 - SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
2394 CFG_OR_TIMING_SDRAM, CFG_OR2_PRELIM, CFG_BR2_PRELIM,
2395 CFG_OR3_PRELIM, CFG_BR3_PRELIM:
2396 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
2398 - CFG_MAMR_PTA, CFG_MPTPR_2BK_4K, CFG_MPTPR_1BK_4K, CFG_MPTPR_2BK_8K,
2399 CFG_MPTPR_1BK_8K, CFG_MAMR_8COL, CFG_MAMR_9COL:
2400 Machine Mode Register and Memory Periodic Timer
2401 Prescaler definitions (SDRAM timing)
2403 - CFG_I2C_UCODE_PATCH, CFG_I2C_DPMEM_OFFSET [0x1FC0]:
2404 enable I2C microcode relocation patch (MPC8xx);
2405 define relocation offset in DPRAM [DSP2]
2407 - CFG_SMC_UCODE_PATCH, CFG_SMC_DPMEM_OFFSET [0x1FC0]:
2408 enable SMC microcode relocation patch (MPC8xx);
2409 define relocation offset in DPRAM [SMC1]
2411 - CFG_SPI_UCODE_PATCH, CFG_SPI_DPMEM_OFFSET [0x1FC0]:
2412 enable SPI microcode relocation patch (MPC8xx);
2413 define relocation offset in DPRAM [SCC4]
2416 Use OSCM clock mode on MBX8xx board. Be careful,
2417 wrong setting might damage your board. Read
2418 doc/README.MBX before setting this variable!
2420 - CFG_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only)
2421 Offset of the bootmode word in DPRAM used by post
2422 (Power On Self Tests). This definition overrides
2423 #define'd default value in commproc.h resp.
2426 - CFG_PCI_SLV_MEM_LOCAL, CFG_PCI_SLV_MEM_BUS, CFG_PICMR0_MASK_ATTRIB,
2427 CFG_PCI_MSTR0_LOCAL, CFG_PCIMSK0_MASK, CFG_PCI_MSTR1_LOCAL,
2428 CFG_PCIMSK1_MASK, CFG_PCI_MSTR_MEM_LOCAL, CFG_PCI_MSTR_MEM_BUS,
2429 CFG_CPU_PCI_MEM_START, CFG_PCI_MSTR_MEM_SIZE, CFG_POCMR0_MASK_ATTRIB,
2430 CFG_PCI_MSTR_MEMIO_LOCAL, CFG_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START,
2431 CFG_PCI_MSTR_MEMIO_SIZE, CFG_POCMR1_MASK_ATTRIB, CFG_PCI_MSTR_IO_LOCAL,
2432 CFG_PCI_MSTR_IO_BUS, CFG_CPU_PCI_IO_START, CFG_PCI_MSTR_IO_SIZE,
2433 CFG_POCMR2_MASK_ATTRIB: (MPC826x only)
2434 Overrides the default PCI memory map in cpu/mpc8260/pci.c if set.
2437 Get DDR timing information from an I2C EEPROM. Common
2438 with pluggable memory modules such as SODIMMs
2441 I2C address of the SPD EEPROM
2444 If SPD EEPROM is on an I2C bus other than the first
2445 one, specify here. Note that the value must resolve
2446 to something your driver can deal with.
2448 - CFG_83XX_DDR_USES_CS0
2449 Only for 83xx systems. If specified, then DDR should
2450 be configured using CS0 and CS1 instead of CS2 and CS3.
2452 - CFG_83XX_DDR_USES_CS0
2453 Only for 83xx systems. If specified, then DDR should
2454 be configured using CS0 and CS1 instead of CS2 and CS3.
2456 - CONFIG_ETHER_ON_FEC[12]
2457 Define to enable FEC[12] on a 8xx series processor.
2459 - CONFIG_FEC[12]_PHY
2460 Define to the hardcoded PHY address which corresponds
2461 to the given FEC; i. e.
2462 #define CONFIG_FEC1_PHY 4
2463 means that the PHY with address 4 is connected to FEC1
2465 When set to -1, means to probe for first available.
2467 - CONFIG_FEC[12]_PHY_NORXERR
2468 The PHY does not have a RXERR line (RMII only).
2469 (so program the FEC to ignore it).
2472 Enable RMII mode for all FECs.
2473 Note that this is a global option, we can't
2474 have one FEC in standard MII mode and another in RMII mode.
2476 - CONFIG_CRC32_VERIFY
2477 Add a verify option to the crc32 command.
2480 => crc32 -v <address> <count> <crc32>
2482 Where address/count indicate a memory area
2483 and crc32 is the correct crc32 which the
2487 Add the "loopw" memory command. This only takes effect if
2488 the memory commands are activated globally (CONFIG_CMD_MEM).
2491 Add the "mdc" and "mwc" memory commands. These are cyclic
2496 This command will print 4 bytes (10,11,12,13) each 500 ms.
2498 => mwc.l 100 12345678 10
2499 This command will write 12345678 to address 100 all 10 ms.
2501 This only takes effect if the memory commands are activated
2502 globally (CONFIG_CMD_MEM).
2504 - CONFIG_SKIP_LOWLEVEL_INIT
2505 - CONFIG_SKIP_RELOCATE_UBOOT
2507 [ARM only] If these variables are defined, then
2508 certain low level initializations (like setting up
2509 the memory controller) are omitted and/or U-Boot does
2510 not relocate itself into RAM.
2511 Normally these variables MUST NOT be defined. The
2512 only exception is when U-Boot is loaded (to RAM) by
2513 some other boot loader or by a debugger which
2514 performs these intializations itself.
2517 Building the Software:
2518 ======================
2520 Building U-Boot has been tested in several native build environments
2521 and in many different cross environments. Of course we cannot support
2522 all possibly existing versions of cross development tools in all
2523 (potentially obsolete) versions. In case of tool chain problems we
2524 recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK)
2525 which is extensively used to build and test U-Boot.
2527 If you are not using a native environment, it is assumed that you
2528 have GNU cross compiling tools available in your path. In this case,
2529 you must set the environment variable CROSS_COMPILE in your shell.
2530 Note that no changes to the Makefile or any other source files are
2531 necessary. For example using the ELDK on a 4xx CPU, please enter:
2533 $ CROSS_COMPILE=ppc_4xx-
2534 $ export CROSS_COMPILE
2536 U-Boot is intended to be simple to build. After installing the
2537 sources you must configure U-Boot for one specific board type. This
2542 where "NAME_config" is the name of one of the existing configu-
2543 rations; see the main Makefile for supported names.
2545 Note: for some board special configuration names may exist; check if
2546 additional information is available from the board vendor; for
2547 instance, the TQM823L systems are available without (standard)
2548 or with LCD support. You can select such additional "features"
2549 when chosing the configuration, i. e.
2552 - will configure for a plain TQM823L, i. e. no LCD support
2554 make TQM823L_LCD_config
2555 - will configure for a TQM823L with U-Boot console on LCD
2560 Finally, type "make all", and you should get some working U-Boot
2561 images ready for download to / installation on your system:
2563 - "u-boot.bin" is a raw binary image
2564 - "u-boot" is an image in ELF binary format
2565 - "u-boot.srec" is in Motorola S-Record format
2567 By default the build is performed locally and the objects are saved
2568 in the source directory. One of the two methods can be used to change
2569 this behavior and build U-Boot to some external directory:
2571 1. Add O= to the make command line invocations:
2573 make O=/tmp/build distclean
2574 make O=/tmp/build NAME_config
2575 make O=/tmp/build all
2577 2. Set environment variable BUILD_DIR to point to the desired location:
2579 export BUILD_DIR=/tmp/build
2584 Note that the command line "O=" setting overrides the BUILD_DIR environment
2588 Please be aware that the Makefiles assume you are using GNU make, so
2589 for instance on NetBSD you might need to use "gmake" instead of
2593 If the system board that you have is not listed, then you will need
2594 to port U-Boot to your hardware platform. To do this, follow these
2597 1. Add a new configuration option for your board to the toplevel
2598 "Makefile" and to the "MAKEALL" script, using the existing
2599 entries as examples. Note that here and at many other places
2600 boards and other names are listed in alphabetical sort order. Please
2602 2. Create a new directory to hold your board specific code. Add any
2603 files you need. In your board directory, you will need at least
2604 the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds".
2605 3. Create a new configuration file "include/configs/<board>.h" for
2607 3. If you're porting U-Boot to a new CPU, then also create a new
2608 directory to hold your CPU specific code. Add any files you need.
2609 4. Run "make <board>_config" with your new name.
2610 5. Type "make", and you should get a working "u-boot.srec" file
2611 to be installed on your target system.
2612 6. Debug and solve any problems that might arise.
2613 [Of course, this last step is much harder than it sounds.]
2616 Testing of U-Boot Modifications, Ports to New Hardware, etc.:
2617 ==============================================================
2619 If you have modified U-Boot sources (for instance added a new board
2620 or support for new devices, a new CPU, etc.) you are expected to
2621 provide feedback to the other developers. The feedback normally takes
2622 the form of a "patch", i. e. a context diff against a certain (latest
2623 official or latest in the git repository) version of U-Boot sources.
2625 But before you submit such a patch, please verify that your modifi-
2626 cation did not break existing code. At least make sure that *ALL* of
2627 the supported boards compile WITHOUT ANY compiler warnings. To do so,
2628 just run the "MAKEALL" script, which will configure and build U-Boot
2629 for ALL supported system. Be warned, this will take a while. You can
2630 select which (cross) compiler to use by passing a `CROSS_COMPILE'
2631 environment variable to the script, i. e. to use the ELDK cross tools
2634 CROSS_COMPILE=ppc_8xx- MAKEALL
2636 or to build on a native PowerPC system you can type
2638 CROSS_COMPILE=' ' MAKEALL
2640 When using the MAKEALL script, the default behaviour is to build
2641 U-Boot in the source directory. This location can be changed by
2642 setting the BUILD_DIR environment variable. Also, for each target
2643 built, the MAKEALL script saves two log files (<target>.ERR and
2644 <target>.MAKEALL) in the <source dir>/LOG directory. This default
2645 location can be changed by setting the MAKEALL_LOGDIR environment
2646 variable. For example:
2648 export BUILD_DIR=/tmp/build
2649 export MAKEALL_LOGDIR=/tmp/log
2650 CROSS_COMPILE=ppc_8xx- MAKEALL
2652 With the above settings build objects are saved in the /tmp/build,
2653 log files are saved in the /tmp/log and the source tree remains clean
2654 during the whole build process.
2657 See also "U-Boot Porting Guide" below.
2660 Monitor Commands - Overview:
2661 ============================
2663 go - start application at address 'addr'
2664 run - run commands in an environment variable
2665 bootm - boot application image from memory
2666 bootp - boot image via network using BootP/TFTP protocol
2667 tftpboot- boot image via network using TFTP protocol
2668 and env variables "ipaddr" and "serverip"
2669 (and eventually "gatewayip")
2670 rarpboot- boot image via network using RARP/TFTP protocol
2671 diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
2672 loads - load S-Record file over serial line
2673 loadb - load binary file over serial line (kermit mode)
2675 mm - memory modify (auto-incrementing)
2676 nm - memory modify (constant address)
2677 mw - memory write (fill)
2679 cmp - memory compare
2680 crc32 - checksum calculation
2681 imd - i2c memory display
2682 imm - i2c memory modify (auto-incrementing)
2683 inm - i2c memory modify (constant address)
2684 imw - i2c memory write (fill)
2685 icrc32 - i2c checksum calculation
2686 iprobe - probe to discover valid I2C chip addresses
2687 iloop - infinite loop on address range
2688 isdram - print SDRAM configuration information
2689 sspi - SPI utility commands
2690 base - print or set address offset
2691 printenv- print environment variables
2692 setenv - set environment variables
2693 saveenv - save environment variables to persistent storage
2694 protect - enable or disable FLASH write protection
2695 erase - erase FLASH memory
2696 flinfo - print FLASH memory information
2697 bdinfo - print Board Info structure
2698 iminfo - print header information for application image
2699 coninfo - print console devices and informations
2700 ide - IDE sub-system
2701 loop - infinite loop on address range
2702 loopw - infinite write loop on address range
2703 mtest - simple RAM test
2704 icache - enable or disable instruction cache
2705 dcache - enable or disable data cache
2706 reset - Perform RESET of the CPU
2707 echo - echo args to console
2708 version - print monitor version
2709 help - print online help
2710 ? - alias for 'help'
2713 Monitor Commands - Detailed Description:
2714 ========================================
2718 For now: just type "help <command>".
2721 Environment Variables:
2722 ======================
2724 U-Boot supports user configuration using Environment Variables which
2725 can be made persistent by saving to Flash memory.
2727 Environment Variables are set using "setenv", printed using
2728 "printenv", and saved to Flash using "saveenv". Using "setenv"
2729 without a value can be used to delete a variable from the
2730 environment. As long as you don't save the environment you are
2731 working with an in-memory copy. In case the Flash area containing the
2732 environment is erased by accident, a default environment is provided.
2734 Some configuration options can be set using Environment Variables:
2736 baudrate - see CONFIG_BAUDRATE
2738 bootdelay - see CONFIG_BOOTDELAY
2740 bootcmd - see CONFIG_BOOTCOMMAND
2742 bootargs - Boot arguments when booting an RTOS image
2744 bootfile - Name of the image to load with TFTP
2746 autoload - if set to "no" (any string beginning with 'n'),
2747 "bootp" will just load perform a lookup of the
2748 configuration from the BOOTP server, but not try to
2749 load any image using TFTP
2751 autoscript - if set to "yes" commands like "loadb", "loady",
2752 "bootp", "tftpb", "rarpboot" and "nfs" will attempt
2753 to automatically run script images (by internally
2754 calling "autoscript").
2756 autoscript_uname - if script image is in a format (FIT) this
2757 variable is used to get script subimage unit name.
2759 autostart - if set to "yes", an image loaded using the "bootp",
2760 "rarpboot", "tftpboot" or "diskboot" commands will
2761 be automatically started (by internally calling
2764 If set to "no", a standalone image passed to the
2765 "bootm" command will be copied to the load address
2766 (and eventually uncompressed), but NOT be started.
2767 This can be used to load and uncompress arbitrary
2770 i2cfast - (PPC405GP|PPC405EP only)
2771 if set to 'y' configures Linux I2C driver for fast
2772 mode (400kHZ). This environment variable is used in
2773 initialization code. So, for changes to be effective
2774 it must be saved and board must be reset.
2776 initrd_high - restrict positioning of initrd images:
2777 If this variable is not set, initrd images will be
2778 copied to the highest possible address in RAM; this
2779 is usually what you want since it allows for
2780 maximum initrd size. If for some reason you want to
2781 make sure that the initrd image is loaded below the
2782 CFG_BOOTMAPSZ limit, you can set this environment
2783 variable to a value of "no" or "off" or "0".
2784 Alternatively, you can set it to a maximum upper
2785 address to use (U-Boot will still check that it
2786 does not overwrite the U-Boot stack and data).
2788 For instance, when you have a system with 16 MB
2789 RAM, and want to reserve 4 MB from use by Linux,
2790 you can do this by adding "mem=12M" to the value of
2791 the "bootargs" variable. However, now you must make
2792 sure that the initrd image is placed in the first
2793 12 MB as well - this can be done with
2795 setenv initrd_high 00c00000
2797 If you set initrd_high to 0xFFFFFFFF, this is an
2798 indication to U-Boot that all addresses are legal
2799 for the Linux kernel, including addresses in flash
2800 memory. In this case U-Boot will NOT COPY the
2801 ramdisk at all. This may be useful to reduce the
2802 boot time on your system, but requires that this
2803 feature is supported by your Linux kernel.
2805 ipaddr - IP address; needed for tftpboot command
2807 loadaddr - Default load address for commands like "bootp",
2808 "rarpboot", "tftpboot", "loadb" or "diskboot"
2810 loads_echo - see CONFIG_LOADS_ECHO
2812 serverip - TFTP server IP address; needed for tftpboot command
2814 bootretry - see CONFIG_BOOT_RETRY_TIME
2816 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
2818 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
2820 ethprime - When CONFIG_NET_MULTI is enabled controls which
2821 interface is used first.
2823 ethact - When CONFIG_NET_MULTI is enabled controls which
2824 interface is currently active. For example you
2825 can do the following
2827 => setenv ethact FEC ETHERNET
2828 => ping 192.168.0.1 # traffic sent on FEC ETHERNET
2829 => setenv ethact SCC ETHERNET
2830 => ping 10.0.0.1 # traffic sent on SCC ETHERNET
2832 ethrotate - When set to "no" U-Boot does not go through all
2833 available network interfaces.
2834 It just stays at the currently selected interface.
2836 netretry - When set to "no" each network operation will
2837 either succeed or fail without retrying.
2838 When set to "once" the network operation will
2839 fail when all the available network interfaces
2840 are tried once without success.
2841 Useful on scripts which control the retry operation
2844 npe_ucode - see CONFIG_IXP4XX_NPE_EXT_UCOD
2845 if set load address for the npe microcode
2847 tftpsrcport - If this is set, the value is used for TFTP's
2850 tftpdstport - If this is set, the value is used for TFTP's UDP
2851 destination port instead of the Well Know Port 69.
2853 vlan - When set to a value < 4095 the traffic over
2854 ethernet is encapsulated/received over 802.1q
2857 The following environment variables may be used and automatically
2858 updated by the network boot commands ("bootp" and "rarpboot"),
2859 depending the information provided by your boot server:
2861 bootfile - see above
2862 dnsip - IP address of your Domain Name Server
2863 dnsip2 - IP address of your secondary Domain Name Server
2864 gatewayip - IP address of the Gateway (Router) to use
2865 hostname - Target hostname
2867 netmask - Subnet Mask
2868 rootpath - Pathname of the root filesystem on the NFS server
2869 serverip - see above
2872 There are two special Environment Variables:
2874 serial# - contains hardware identification information such
2875 as type string and/or serial number
2876 ethaddr - Ethernet address
2878 These variables can be set only once (usually during manufacturing of
2879 the board). U-Boot refuses to delete or overwrite these variables
2880 once they have been set once.
2883 Further special Environment Variables:
2885 ver - Contains the U-Boot version string as printed
2886 with the "version" command. This variable is
2887 readonly (see CONFIG_VERSION_VARIABLE).
2890 Please note that changes to some configuration parameters may take
2891 only effect after the next boot (yes, that's just like Windoze :-).
2894 Command Line Parsing:
2895 =====================
2897 There are two different command line parsers available with U-Boot:
2898 the old "simple" one, and the much more powerful "hush" shell:
2900 Old, simple command line parser:
2901 --------------------------------
2903 - supports environment variables (through setenv / saveenv commands)
2904 - several commands on one line, separated by ';'
2905 - variable substitution using "... ${name} ..." syntax
2906 - special characters ('$', ';') can be escaped by prefixing with '\',
2908 setenv bootcmd bootm \${address}
2909 - You can also escape text by enclosing in single apostrophes, for example:
2910 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
2915 - similar to Bourne shell, with control structures like
2916 if...then...else...fi, for...do...done; while...do...done,
2917 until...do...done, ...
2918 - supports environment ("global") variables (through setenv / saveenv
2919 commands) and local shell variables (through standard shell syntax
2920 "name=value"); only environment variables can be used with "run"
2926 (1) If a command line (or an environment variable executed by a "run"
2927 command) contains several commands separated by semicolon, and
2928 one of these commands fails, then the remaining commands will be
2931 (2) If you execute several variables with one call to run (i. e.
2932 calling run with a list af variables as arguments), any failing
2933 command will cause "run" to terminate, i. e. the remaining
2934 variables are not executed.
2936 Note for Redundant Ethernet Interfaces:
2937 =======================================
2939 Some boards come with redundant ethernet interfaces; U-Boot supports
2940 such configurations and is capable of automatic selection of a
2941 "working" interface when needed. MAC assignment works as follows:
2943 Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
2944 MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
2945 "eth1addr" (=>eth1), "eth2addr", ...
2947 If the network interface stores some valid MAC address (for instance
2948 in SROM), this is used as default address if there is NO correspon-
2949 ding setting in the environment; if the corresponding environment
2950 variable is set, this overrides the settings in the card; that means:
2952 o If the SROM has a valid MAC address, and there is no address in the
2953 environment, the SROM's address is used.
2955 o If there is no valid address in the SROM, and a definition in the
2956 environment exists, then the value from the environment variable is
2959 o If both the SROM and the environment contain a MAC address, and
2960 both addresses are the same, this MAC address is used.
2962 o If both the SROM and the environment contain a MAC address, and the
2963 addresses differ, the value from the environment is used and a
2966 o If neither SROM nor the environment contain a MAC address, an error
2973 U-Boot is capable of booting (and performing other auxiliary operations on)
2974 images in two formats:
2976 New uImage format (FIT)
2977 -----------------------
2979 Flexible and powerful format based on Flattened Image Tree -- FIT (similar
2980 to Flattened Device Tree). It allows the use of images with multiple
2981 components (several kernels, ramdisks, etc.), with contents protected by
2982 SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory.
2988 Old image format is based on binary files which can be basically anything,
2989 preceded by a special header; see the definitions in include/image.h for
2990 details; basically, the header defines the following image properties:
2992 * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
2993 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
2994 LynxOS, pSOS, QNX, RTEMS, ARTOS;
2995 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, ARTOS, LynxOS).
2996 * Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86,
2997 IA64, MIPS, NIOS, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
2998 Currently supported: ARM, AVR32, Intel x86, MIPS, NIOS, PowerPC).
2999 * Compression Type (uncompressed, gzip, bzip2)
3005 The header is marked by a special Magic Number, and both the header
3006 and the data portions of the image are secured against corruption by
3013 Although U-Boot should support any OS or standalone application
3014 easily, the main focus has always been on Linux during the design of
3017 U-Boot includes many features that so far have been part of some
3018 special "boot loader" code within the Linux kernel. Also, any
3019 "initrd" images to be used are no longer part of one big Linux image;
3020 instead, kernel and "initrd" are separate images. This implementation
3021 serves several purposes:
3023 - the same features can be used for other OS or standalone
3024 applications (for instance: using compressed images to reduce the
3025 Flash memory footprint)
3027 - it becomes much easier to port new Linux kernel versions because
3028 lots of low-level, hardware dependent stuff are done by U-Boot
3030 - the same Linux kernel image can now be used with different "initrd"
3031 images; of course this also means that different kernel images can
3032 be run with the same "initrd". This makes testing easier (you don't
3033 have to build a new "zImage.initrd" Linux image when you just
3034 change a file in your "initrd"). Also, a field-upgrade of the
3035 software is easier now.
3041 Porting Linux to U-Boot based systems:
3042 ---------------------------------------
3044 U-Boot cannot save you from doing all the necessary modifications to
3045 configure the Linux device drivers for use with your target hardware
3046 (no, we don't intend to provide a full virtual machine interface to
3049 But now you can ignore ALL boot loader code (in arch/ppc/mbxboot).
3051 Just make sure your machine specific header file (for instance
3052 include/asm-ppc/tqm8xx.h) includes the same definition of the Board
3053 Information structure as we define in include/u-boot.h, and make
3054 sure that your definition of IMAP_ADDR uses the same value as your
3055 U-Boot configuration in CFG_IMMR.
3058 Configuring the Linux kernel:
3059 -----------------------------
3061 No specific requirements for U-Boot. Make sure you have some root
3062 device (initial ramdisk, NFS) for your target system.
3065 Building a Linux Image:
3066 -----------------------
3068 With U-Boot, "normal" build targets like "zImage" or "bzImage" are
3069 not used. If you use recent kernel source, a new build target
3070 "uImage" will exist which automatically builds an image usable by
3071 U-Boot. Most older kernels also have support for a "pImage" target,
3072 which was introduced for our predecessor project PPCBoot and uses a
3073 100% compatible format.
3082 The "uImage" build target uses a special tool (in 'tools/mkimage') to
3083 encapsulate a compressed Linux kernel image with header information,
3084 CRC32 checksum etc. for use with U-Boot. This is what we are doing:
3086 * build a standard "vmlinux" kernel image (in ELF binary format):
3088 * convert the kernel into a raw binary image:
3090 ${CROSS_COMPILE}-objcopy -O binary \
3091 -R .note -R .comment \
3092 -S vmlinux linux.bin
3094 * compress the binary image:
3098 * package compressed binary image for U-Boot:
3100 mkimage -A ppc -O linux -T kernel -C gzip \
3101 -a 0 -e 0 -n "Linux Kernel Image" \
3102 -d linux.bin.gz uImage
3105 The "mkimage" tool can also be used to create ramdisk images for use
3106 with U-Boot, either separated from the Linux kernel image, or
3107 combined into one file. "mkimage" encapsulates the images with a 64
3108 byte header containing information about target architecture,
3109 operating system, image type, compression method, entry points, time
3110 stamp, CRC32 checksums, etc.
3112 "mkimage" can be called in two ways: to verify existing images and
3113 print the header information, or to build new images.
3115 In the first form (with "-l" option) mkimage lists the information
3116 contained in the header of an existing U-Boot image; this includes
3117 checksum verification:
3119 tools/mkimage -l image
3120 -l ==> list image header information
3122 The second form (with "-d" option) is used to build a U-Boot image
3123 from a "data file" which is used as image payload:
3125 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
3126 -n name -d data_file image
3127 -A ==> set architecture to 'arch'
3128 -O ==> set operating system to 'os'
3129 -T ==> set image type to 'type'
3130 -C ==> set compression type 'comp'
3131 -a ==> set load address to 'addr' (hex)
3132 -e ==> set entry point to 'ep' (hex)
3133 -n ==> set image name to 'name'
3134 -d ==> use image data from 'datafile'
3136 Right now, all Linux kernels for PowerPC systems use the same load
3137 address (0x00000000), but the entry point address depends on the
3140 - 2.2.x kernels have the entry point at 0x0000000C,
3141 - 2.3.x and later kernels have the entry point at 0x00000000.
3143 So a typical call to build a U-Boot image would read:
3145 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
3146 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
3147 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux.gz \
3148 > examples/uImage.TQM850L
3149 Image Name: 2.4.4 kernel for TQM850L
3150 Created: Wed Jul 19 02:34:59 2000
3151 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3152 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
3153 Load Address: 0x00000000
3154 Entry Point: 0x00000000
3156 To verify the contents of the image (or check for corruption):
3158 -> tools/mkimage -l examples/uImage.TQM850L
3159 Image Name: 2.4.4 kernel for TQM850L
3160 Created: Wed Jul 19 02:34:59 2000
3161 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3162 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
3163 Load Address: 0x00000000
3164 Entry Point: 0x00000000
3166 NOTE: for embedded systems where boot time is critical you can trade
3167 speed for memory and install an UNCOMPRESSED image instead: this
3168 needs more space in Flash, but boots much faster since it does not
3169 need to be uncompressed:
3171 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux.gz
3172 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
3173 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
3174 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux \
3175 > examples/uImage.TQM850L-uncompressed
3176 Image Name: 2.4.4 kernel for TQM850L
3177 Created: Wed Jul 19 02:34:59 2000
3178 Image Type: PowerPC Linux Kernel Image (uncompressed)
3179 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
3180 Load Address: 0x00000000
3181 Entry Point: 0x00000000
3184 Similar you can build U-Boot images from a 'ramdisk.image.gz' file
3185 when your kernel is intended to use an initial ramdisk:
3187 -> tools/mkimage -n 'Simple Ramdisk Image' \
3188 > -A ppc -O linux -T ramdisk -C gzip \
3189 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
3190 Image Name: Simple Ramdisk Image
3191 Created: Wed Jan 12 14:01:50 2000
3192 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
3193 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
3194 Load Address: 0x00000000
3195 Entry Point: 0x00000000
3198 Installing a Linux Image:
3199 -------------------------
3201 To downloading a U-Boot image over the serial (console) interface,
3202 you must convert the image to S-Record format:
3204 objcopy -I binary -O srec examples/image examples/image.srec
3206 The 'objcopy' does not understand the information in the U-Boot
3207 image header, so the resulting S-Record file will be relative to
3208 address 0x00000000. To load it to a given address, you need to
3209 specify the target address as 'offset' parameter with the 'loads'
3212 Example: install the image to address 0x40100000 (which on the
3213 TQM8xxL is in the first Flash bank):
3215 => erase 40100000 401FFFFF
3221 ## Ready for S-Record download ...
3222 ~>examples/image.srec
3223 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
3225 15989 15990 15991 15992
3226 [file transfer complete]
3228 ## Start Addr = 0x00000000
3231 You can check the success of the download using the 'iminfo' command;
3232 this includes a checksum verification so you can be sure no data
3233 corruption happened:
3237 ## Checking Image at 40100000 ...
3238 Image Name: 2.2.13 for initrd on TQM850L
3239 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3240 Data Size: 335725 Bytes = 327 kB = 0 MB
3241 Load Address: 00000000
3242 Entry Point: 0000000c
3243 Verifying Checksum ... OK
3249 The "bootm" command is used to boot an application that is stored in
3250 memory (RAM or Flash). In case of a Linux kernel image, the contents
3251 of the "bootargs" environment variable is passed to the kernel as
3252 parameters. You can check and modify this variable using the
3253 "printenv" and "setenv" commands:
3256 => printenv bootargs
3257 bootargs=root=/dev/ram
3259 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
3261 => printenv bootargs
3262 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
3265 ## Booting Linux kernel at 40020000 ...
3266 Image Name: 2.2.13 for NFS on TQM850L
3267 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3268 Data Size: 381681 Bytes = 372 kB = 0 MB
3269 Load Address: 00000000
3270 Entry Point: 0000000c
3271 Verifying Checksum ... OK
3272 Uncompressing Kernel Image ... OK
3273 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
3274 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
3275 time_init: decrementer frequency = 187500000/60
3276 Calibrating delay loop... 49.77 BogoMIPS
3277 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
3280 If you want to boot a Linux kernel with initial ram disk, you pass
3281 the memory addresses of both the kernel and the initrd image (PPBCOOT
3282 format!) to the "bootm" command:
3284 => imi 40100000 40200000
3286 ## Checking Image at 40100000 ...
3287 Image Name: 2.2.13 for initrd on TQM850L
3288 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3289 Data Size: 335725 Bytes = 327 kB = 0 MB
3290 Load Address: 00000000
3291 Entry Point: 0000000c
3292 Verifying Checksum ... OK
3294 ## Checking Image at 40200000 ...
3295 Image Name: Simple Ramdisk Image
3296 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
3297 Data Size: 566530 Bytes = 553 kB = 0 MB
3298 Load Address: 00000000
3299 Entry Point: 00000000
3300 Verifying Checksum ... OK
3302 => bootm 40100000 40200000
3303 ## Booting Linux kernel at 40100000 ...
3304 Image Name: 2.2.13 for initrd on TQM850L
3305 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3306 Data Size: 335725 Bytes = 327 kB = 0 MB
3307 Load Address: 00000000
3308 Entry Point: 0000000c
3309 Verifying Checksum ... OK
3310 Uncompressing Kernel Image ... OK
3311 ## Loading RAMDisk Image at 40200000 ...
3312 Image Name: Simple Ramdisk Image
3313 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
3314 Data Size: 566530 Bytes = 553 kB = 0 MB
3315 Load Address: 00000000
3316 Entry Point: 00000000
3317 Verifying Checksum ... OK
3318 Loading Ramdisk ... OK
3319 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
3320 Boot arguments: root=/dev/ram
3321 time_init: decrementer frequency = 187500000/60
3322 Calibrating delay loop... 49.77 BogoMIPS
3324 RAMDISK: Compressed image found at block 0
3325 VFS: Mounted root (ext2 filesystem).
3329 Boot Linux and pass a flat device tree:
3332 First, U-Boot must be compiled with the appropriate defines. See the section
3333 titled "Linux Kernel Interface" above for a more in depth explanation. The
3334 following is an example of how to start a kernel and pass an updated
3340 oft=oftrees/mpc8540ads.dtb
3341 => tftp $oftaddr $oft
3342 Speed: 1000, full duplex
3344 TFTP from server 192.168.1.1; our IP address is 192.168.1.101
3345 Filename 'oftrees/mpc8540ads.dtb'.
3346 Load address: 0x300000
3349 Bytes transferred = 4106 (100a hex)
3350 => tftp $loadaddr $bootfile
3351 Speed: 1000, full duplex
3353 TFTP from server 192.168.1.1; our IP address is 192.168.1.2
3355 Load address: 0x200000
3356 Loading:############
3358 Bytes transferred = 1029407 (fb51f hex)
3363 => bootm $loadaddr - $oftaddr
3364 ## Booting image at 00200000 ...
3365 Image Name: Linux-2.6.17-dirty
3366 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3367 Data Size: 1029343 Bytes = 1005.2 kB
3368 Load Address: 00000000
3369 Entry Point: 00000000
3370 Verifying Checksum ... OK
3371 Uncompressing Kernel Image ... OK
3372 Booting using flat device tree at 0x300000
3373 Using MPC85xx ADS machine description
3374 Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb
3378 More About U-Boot Image Types:
3379 ------------------------------
3381 U-Boot supports the following image types:
3383 "Standalone Programs" are directly runnable in the environment
3384 provided by U-Boot; it is expected that (if they behave
3385 well) you can continue to work in U-Boot after return from
3386 the Standalone Program.
3387 "OS Kernel Images" are usually images of some Embedded OS which
3388 will take over control completely. Usually these programs
3389 will install their own set of exception handlers, device
3390 drivers, set up the MMU, etc. - this means, that you cannot
3391 expect to re-enter U-Boot except by resetting the CPU.
3392 "RAMDisk Images" are more or less just data blocks, and their
3393 parameters (address, size) are passed to an OS kernel that is
3395 "Multi-File Images" contain several images, typically an OS
3396 (Linux) kernel image and one or more data images like
3397 RAMDisks. This construct is useful for instance when you want
3398 to boot over the network using BOOTP etc., where the boot
3399 server provides just a single image file, but you want to get
3400 for instance an OS kernel and a RAMDisk image.
3402 "Multi-File Images" start with a list of image sizes, each
3403 image size (in bytes) specified by an "uint32_t" in network
3404 byte order. This list is terminated by an "(uint32_t)0".
3405 Immediately after the terminating 0 follow the images, one by
3406 one, all aligned on "uint32_t" boundaries (size rounded up to
3407 a multiple of 4 bytes).
3409 "Firmware Images" are binary images containing firmware (like
3410 U-Boot or FPGA images) which usually will be programmed to
3413 "Script files" are command sequences that will be executed by
3414 U-Boot's command interpreter; this feature is especially
3415 useful when you configure U-Boot to use a real shell (hush)
3416 as command interpreter.
3422 One of the features of U-Boot is that you can dynamically load and
3423 run "standalone" applications, which can use some resources of
3424 U-Boot like console I/O functions or interrupt services.
3426 Two simple examples are included with the sources:
3431 'examples/hello_world.c' contains a small "Hello World" Demo
3432 application; it is automatically compiled when you build U-Boot.
3433 It's configured to run at address 0x00040004, so you can play with it
3437 ## Ready for S-Record download ...
3438 ~>examples/hello_world.srec
3439 1 2 3 4 5 6 7 8 9 10 11 ...
3440 [file transfer complete]
3442 ## Start Addr = 0x00040004
3444 => go 40004 Hello World! This is a test.
3445 ## Starting application at 0x00040004 ...
3456 Hit any key to exit ...
3458 ## Application terminated, rc = 0x0
3460 Another example, which demonstrates how to register a CPM interrupt
3461 handler with the U-Boot code, can be found in 'examples/timer.c'.
3462 Here, a CPM timer is set up to generate an interrupt every second.
3463 The interrupt service routine is trivial, just printing a '.'
3464 character, but this is just a demo program. The application can be
3465 controlled by the following keys:
3467 ? - print current values og the CPM Timer registers
3468 b - enable interrupts and start timer
3469 e - stop timer and disable interrupts
3470 q - quit application
3473 ## Ready for S-Record download ...
3474 ~>examples/timer.srec
3475 1 2 3 4 5 6 7 8 9 10 11 ...
3476 [file transfer complete]
3478 ## Start Addr = 0x00040004
3481 ## Starting application at 0x00040004 ...
3484 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
3487 [q, b, e, ?] Set interval 1000000 us
3490 [q, b, e, ?] ........
3491 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
3494 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
3497 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
3500 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
3502 [q, b, e, ?] ...Stopping timer
3504 [q, b, e, ?] ## Application terminated, rc = 0x0
3510 Over time, many people have reported problems when trying to use the
3511 "minicom" terminal emulation program for serial download. I (wd)
3512 consider minicom to be broken, and recommend not to use it. Under
3513 Unix, I recommend to use C-Kermit for general purpose use (and
3514 especially for kermit binary protocol download ("loadb" command), and
3515 use "cu" for S-Record download ("loads" command).
3517 Nevertheless, if you absolutely want to use it try adding this
3518 configuration to your "File transfer protocols" section:
3520 Name Program Name U/D FullScr IO-Red. Multi
3521 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
3522 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
3528 Starting at version 0.9.2, U-Boot supports NetBSD both as host
3529 (build U-Boot) and target system (boots NetBSD/mpc8xx).
3531 Building requires a cross environment; it is known to work on
3532 NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
3533 need gmake since the Makefiles are not compatible with BSD make).
3534 Note that the cross-powerpc package does not install include files;
3535 attempting to build U-Boot will fail because <machine/ansi.h> is
3536 missing. This file has to be installed and patched manually:
3538 # cd /usr/pkg/cross/powerpc-netbsd/include
3540 # ln -s powerpc machine
3541 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
3542 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
3544 Native builds *don't* work due to incompatibilities between native
3545 and U-Boot include files.
3547 Booting assumes that (the first part of) the image booted is a
3548 stage-2 loader which in turn loads and then invokes the kernel
3549 proper. Loader sources will eventually appear in the NetBSD source
3550 tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
3551 meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz
3554 Implementation Internals:
3555 =========================
3557 The following is not intended to be a complete description of every
3558 implementation detail. However, it should help to understand the
3559 inner workings of U-Boot and make it easier to port it to custom
3563 Initial Stack, Global Data:
3564 ---------------------------
3566 The implementation of U-Boot is complicated by the fact that U-Boot
3567 starts running out of ROM (flash memory), usually without access to
3568 system RAM (because the memory controller is not initialized yet).
3569 This means that we don't have writable Data or BSS segments, and BSS
3570 is not initialized as zero. To be able to get a C environment working
3571 at all, we have to allocate at least a minimal stack. Implementation
3572 options for this are defined and restricted by the CPU used: Some CPU
3573 models provide on-chip memory (like the IMMR area on MPC8xx and
3574 MPC826x processors), on others (parts of) the data cache can be
3575 locked as (mis-) used as memory, etc.
3577 Chris Hallinan posted a good summary of these issues to the
3578 u-boot-users mailing list:
3580 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
3581 From: "Chris Hallinan" <clh@net1plus.com>
3582 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
3585 Correct me if I'm wrong, folks, but the way I understand it
3586 is this: Using DCACHE as initial RAM for Stack, etc, does not
3587 require any physical RAM backing up the cache. The cleverness
3588 is that the cache is being used as a temporary supply of
3589 necessary storage before the SDRAM controller is setup. It's
3590 beyond the scope of this list to expain the details, but you
3591 can see how this works by studying the cache architecture and
3592 operation in the architecture and processor-specific manuals.
3594 OCM is On Chip Memory, which I believe the 405GP has 4K. It
3595 is another option for the system designer to use as an
3596 initial stack/ram area prior to SDRAM being available. Either
3597 option should work for you. Using CS 4 should be fine if your
3598 board designers haven't used it for something that would
3599 cause you grief during the initial boot! It is frequently not
3602 CFG_INIT_RAM_ADDR should be somewhere that won't interfere
3603 with your processor/board/system design. The default value
3604 you will find in any recent u-boot distribution in
3605 walnut.h should work for you. I'd set it to a value larger
3606 than your SDRAM module. If you have a 64MB SDRAM module, set
3607 it above 400_0000. Just make sure your board has no resources
3608 that are supposed to respond to that address! That code in
3609 start.S has been around a while and should work as is when
3610 you get the config right.
3615 It is essential to remember this, since it has some impact on the C
3616 code for the initialization procedures:
3618 * Initialized global data (data segment) is read-only. Do not attempt
3621 * Do not use any unitialized global data (or implicitely initialized
3622 as zero data - BSS segment) at all - this is undefined, initiali-
3623 zation is performed later (when relocating to RAM).
3625 * Stack space is very limited. Avoid big data buffers or things like
3628 Having only the stack as writable memory limits means we cannot use
3629 normal global data to share information beween the code. But it
3630 turned out that the implementation of U-Boot can be greatly
3631 simplified by making a global data structure (gd_t) available to all
3632 functions. We could pass a pointer to this data as argument to _all_
3633 functions, but this would bloat the code. Instead we use a feature of
3634 the GCC compiler (Global Register Variables) to share the data: we
3635 place a pointer (gd) to the global data into a register which we
3636 reserve for this purpose.
3638 When choosing a register for such a purpose we are restricted by the
3639 relevant (E)ABI specifications for the current architecture, and by
3640 GCC's implementation.
3642 For PowerPC, the following registers have specific use:
3644 R2: reserved for system use
3645 R3-R4: parameter passing and return values
3646 R5-R10: parameter passing
3647 R13: small data area pointer
3651 (U-Boot also uses R14 as internal GOT pointer.)
3653 ==> U-Boot will use R2 to hold a pointer to the global data
3655 Note: on PPC, we could use a static initializer (since the
3656 address of the global data structure is known at compile time),
3657 but it turned out that reserving a register results in somewhat
3658 smaller code - although the code savings are not that big (on
3659 average for all boards 752 bytes for the whole U-Boot image,
3660 624 text + 127 data).
3662 On Blackfin, the normal C ABI (except for P5) is followed as documented here:
3663 http://docs.blackfin.uclinux.org/doku.php?id=application_binary_interface
3665 ==> U-Boot will use P5 to hold a pointer to the global data
3667 On ARM, the following registers are used:
3669 R0: function argument word/integer result
3670 R1-R3: function argument word
3672 R10: stack limit (used only if stack checking if enabled)
3673 R11: argument (frame) pointer
3674 R12: temporary workspace
3677 R15: program counter
3679 ==> U-Boot will use R8 to hold a pointer to the global data
3681 NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope,
3682 or current versions of GCC may "optimize" the code too much.
3687 U-Boot runs in system state and uses physical addresses, i.e. the
3688 MMU is not used either for address mapping nor for memory protection.
3690 The available memory is mapped to fixed addresses using the memory
3691 controller. In this process, a contiguous block is formed for each
3692 memory type (Flash, SDRAM, SRAM), even when it consists of several
3693 physical memory banks.
3695 U-Boot is installed in the first 128 kB of the first Flash bank (on
3696 TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
3697 booting and sizing and initializing DRAM, the code relocates itself
3698 to the upper end of DRAM. Immediately below the U-Boot code some
3699 memory is reserved for use by malloc() [see CFG_MALLOC_LEN
3700 configuration setting]. Below that, a structure with global Board
3701 Info data is placed, followed by the stack (growing downward).
3703 Additionally, some exception handler code is copied to the low 8 kB
3704 of DRAM (0x00000000 ... 0x00001FFF).
3706 So a typical memory configuration with 16 MB of DRAM could look like
3709 0x0000 0000 Exception Vector code
3712 0x0000 2000 Free for Application Use
3718 0x00FB FF20 Monitor Stack (Growing downward)
3719 0x00FB FFAC Board Info Data and permanent copy of global data
3720 0x00FC 0000 Malloc Arena
3723 0x00FE 0000 RAM Copy of Monitor Code
3724 ... eventually: LCD or video framebuffer
3725 ... eventually: pRAM (Protected RAM - unchanged by reset)
3726 0x00FF FFFF [End of RAM]
3729 System Initialization:
3730 ----------------------
3732 In the reset configuration, U-Boot starts at the reset entry point
3733 (on most PowerPC systens at address 0x00000100). Because of the reset
3734 configuration for CS0# this is a mirror of the onboard Flash memory.
3735 To be able to re-map memory U-Boot then jumps to its link address.
3736 To be able to implement the initialization code in C, a (small!)
3737 initial stack is set up in the internal Dual Ported RAM (in case CPUs
3738 which provide such a feature like MPC8xx or MPC8260), or in a locked
3739 part of the data cache. After that, U-Boot initializes the CPU core,
3740 the caches and the SIU.
3742 Next, all (potentially) available memory banks are mapped using a
3743 preliminary mapping. For example, we put them on 512 MB boundaries
3744 (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
3745 on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
3746 programmed for SDRAM access. Using the temporary configuration, a
3747 simple memory test is run that determines the size of the SDRAM
3750 When there is more than one SDRAM bank, and the banks are of
3751 different size, the largest is mapped first. For equal size, the first
3752 bank (CS2#) is mapped first. The first mapping is always for address
3753 0x00000000, with any additional banks following immediately to create
3754 contiguous memory starting from 0.
3756 Then, the monitor installs itself at the upper end of the SDRAM area
3757 and allocates memory for use by malloc() and for the global Board
3758 Info data; also, the exception vector code is copied to the low RAM
3759 pages, and the final stack is set up.
3761 Only after this relocation will you have a "normal" C environment;
3762 until that you are restricted in several ways, mostly because you are
3763 running from ROM, and because the code will have to be relocated to a
3767 U-Boot Porting Guide:
3768 ----------------------
3770 [Based on messages by Jerry Van Baren in the U-Boot-Users mailing
3774 int main (int argc, char *argv[])
3776 sighandler_t no_more_time;
3778 signal (SIGALRM, no_more_time);
3779 alarm (PROJECT_DEADLINE - toSec (3 * WEEK));
3781 if (available_money > available_manpower) {
3782 pay consultant to port U-Boot;
3786 Download latest U-Boot source;
3788 Subscribe to u-boot-users mailing list;
3791 email ("Hi, I am new to U-Boot, how do I get started?");
3795 Read the README file in the top level directory;
3796 Read http://www.denx.de/twiki/bin/view/DULG/Manual ;
3797 Read the source, Luke;
3800 if (available_money > toLocalCurrency ($2500)) {
3803 Add a lot of aggravation and time;
3806 Create your own board support subdirectory;
3808 Create your own board config file;
3812 Add / modify source code;
3816 email ("Hi, I am having problems...");
3818 Send patch file to Wolfgang;
3823 void no_more_time (int sig)
3832 All contributions to U-Boot should conform to the Linux kernel
3833 coding style; see the file "Documentation/CodingStyle" and the script
3834 "scripts/Lindent" in your Linux kernel source directory. In sources
3835 originating from U-Boot a style corresponding to "Lindent -pcs" (adding
3836 spaces before parameters to function calls) is actually used.
3838 Source files originating from a different project (for example the
3839 MTD subsystem) are generally exempt from these guidelines and are not
3840 reformated to ease subsequent migration to newer versions of those
3843 Please note that U-Boot is implemented in C (and to some small parts in
3844 Assembler); no C++ is used, so please do not use C++ style comments (//)
3847 Please also stick to the following formatting rules:
3848 - remove any trailing white space
3849 - use TAB characters for indentation, not spaces
3850 - make sure NOT to use DOS '\r\n' line feeds
3851 - do not add more than 2 empty lines to source files
3852 - do not add trailing empty lines to source files
3854 Submissions which do not conform to the standards may be returned
3855 with a request to reformat the changes.
3861 Since the number of patches for U-Boot is growing, we need to
3862 establish some rules. Submissions which do not conform to these rules
3863 may be rejected, even when they contain important and valuable stuff.
3865 Patches shall be sent to the u-boot-users mailing list.
3867 Please see http://www.denx.de/wiki/UBoot/Patches for details.
3869 When you send a patch, please include the following information with
3872 * For bug fixes: a description of the bug and how your patch fixes
3873 this bug. Please try to include a way of demonstrating that the
3874 patch actually fixes something.
3876 * For new features: a description of the feature and your
3879 * A CHANGELOG entry as plaintext (separate from the patch)
3881 * For major contributions, your entry to the CREDITS file
3883 * When you add support for a new board, don't forget to add this
3884 board to the MAKEALL script, too.
3886 * If your patch adds new configuration options, don't forget to
3887 document these in the README file.
3889 * The patch itself. If you are using git (which is *strongly*
3890 recommended) you can easily generate the patch using the
3891 "git-format-patch". If you then use "git-send-email" to send it to
3892 the U-Boot mailing list, you will avoid most of the common problems
3893 with some other mail clients.
3895 If you cannot use git, use "diff -purN OLD NEW". If your version of
3896 diff does not support these options, then get the latest version of
3899 The current directory when running this command shall be the parent
3900 directory of the U-Boot source tree (i. e. please make sure that
3901 your patch includes sufficient directory information for the
3904 We prefer patches as plain text. MIME attachments are discouraged,
3905 and compressed attachments must not be used.
3907 * If one logical set of modifications affects or creates several
3908 files, all these changes shall be submitted in a SINGLE patch file.
3910 * Changesets that contain different, unrelated modifications shall be
3911 submitted as SEPARATE patches, one patch per changeset.
3916 * Before sending the patch, run the MAKEALL script on your patched
3917 source tree and make sure that no errors or warnings are reported
3918 for any of the boards.
3920 * Keep your modifications to the necessary minimum: A patch
3921 containing several unrelated changes or arbitrary reformats will be
3922 returned with a request to re-formatting / split it.
3924 * If you modify existing code, make sure that your new code does not
3925 add to the memory footprint of the code ;-) Small is beautiful!
3926 When adding new features, these should compile conditionally only
3927 (using #ifdef), and the resulting code with the new feature
3928 disabled must not need more memory than the old code without your
3931 * Remember that there is a size limit of 40 kB per message on the
3932 u-boot-users mailing list. Bigger patches will be moderated. If
3933 they are reasonable and not bigger than 100 kB, they will be
3934 acknowledged. Even bigger patches should be avoided.
projects / people / ms / u-boot.git / blob