2 # (C) Copyright 2000 - 2008
3 # Wolfgang Denk, DENX Software Engineering, wd@denx.de.
5 # See file CREDITS for list of people who contributed to this
8 # This program is free software; you can redistribute it and/or
9 # modify it under the terms of the GNU General Public License as
10 # published by the Free Software Foundation; either version 2 of
11 # the License, or (at your option) any later version.
13 # This program is distributed in the hope that it will be useful,
14 # but WITHOUT ANY WARRANTY; without even the implied warranty of
15 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 # GNU General Public License for more details.
18 # You should have received a copy of the GNU General Public License
19 # along with this program; if not, write to the Free Software
20 # Foundation, Inc., 59 Temple Place, Suite 330, Boston,
27 This directory contains the source code for U-Boot, a boot loader for
28 Embedded boards based on PowerPC, ARM, MIPS and several other
29 processors, which can be installed in a boot ROM and used to
30 initialize and test the hardware or to download and run application
33 The development of U-Boot is closely related to Linux: some parts of
34 the source code originate in the Linux source tree, we have some
35 header files in common, and special provision has been made to
36 support booting of Linux images.
38 Some attention has been paid to make this software easily
39 configurable and extendable. For instance, all monitor commands are
40 implemented with the same call interface, so that it's very easy to
41 add new commands. Also, instead of permanently adding rarely used
42 code (for instance hardware test utilities) to the monitor, you can
43 load and run it dynamically.
49 In general, all boards for which a configuration option exists in the
50 Makefile have been tested to some extent and can be considered
51 "working". In fact, many of them are used in production systems.
53 In case of problems see the CHANGELOG and CREDITS files to find out
54 who contributed the specific port. The MAINTAINERS file lists board
61 In case you have questions about, problems with or contributions for
62 U-Boot you should send a message to the U-Boot mailing list at
63 <u-boot-users@lists.sourceforge.net>. There is also an archive of
64 previous traffic on the mailing list - please search the archive
65 before asking FAQ's. Please see
66 http://lists.sourceforge.net/lists/listinfo/u-boot-users/
69 Where to get source code:
70 =========================
72 The U-Boot source code is maintained in the git repository at
73 git://www.denx.de/git/u-boot.git ; you can browse it online at
74 http://www.denx.de/cgi-bin/gitweb.cgi?p=u-boot.git;a=summary
76 The "snapshot" links on this page allow you to download tarballs of
77 any version you might be interested in. Ofifcial releases are also
78 available for FTP download from the ftp://ftp.denx.de/pub/u-boot/
81 Pre-built (and tested) images are available from
82 ftp://ftp.denx.de/pub/u-boot/images/
88 - start from 8xxrom sources
89 - create PPCBoot project (http://sourceforge.net/projects/ppcboot)
91 - make it easier to add custom boards
92 - make it possible to add other [PowerPC] CPUs
93 - extend functions, especially:
94 * Provide extended interface to Linux boot loader
97 * PCMCIA / CompactFLash / ATA disk / SCSI ... boot
98 - create ARMBoot project (http://sourceforge.net/projects/armboot)
99 - add other CPU families (starting with ARM)
100 - create U-Boot project (http://sourceforge.net/projects/u-boot)
101 - current project page: see http://www.denx.de/wiki/UBoot
107 The "official" name of this project is "Das U-Boot". The spelling
108 "U-Boot" shall be used in all written text (documentation, comments
109 in source files etc.). Example:
111 This is the README file for the U-Boot project.
113 File names etc. shall be based on the string "u-boot". Examples:
115 include/asm-ppc/u-boot.h
117 #include <asm/u-boot.h>
119 Variable names, preprocessor constants etc. shall be either based on
120 the string "u_boot" or on "U_BOOT". Example:
122 U_BOOT_VERSION u_boot_logo
123 IH_OS_U_BOOT u_boot_hush_start
129 U-Boot uses a 3 level version number containing a version, a
130 sub-version, and a patchlevel: "U-Boot-2.34.5" means version "2",
131 sub-version "34", and patchlevel "4".
133 The patchlevel is used to indicate certain stages of development
134 between released versions, i. e. officially released versions of
135 U-Boot will always have a patchlevel of "0".
141 - board Board dependent files
142 - common Misc architecture independent functions
143 - cpu CPU specific files
144 - 74xx_7xx Files specific to Freescale MPC74xx and 7xx CPUs
145 - arm720t Files specific to ARM 720 CPUs
146 - arm920t Files specific to ARM 920 CPUs
147 - at91rm9200 Files specific to Atmel AT91RM9200 CPU
148 - imx Files specific to Freescale MC9328 i.MX CPUs
149 - s3c24x0 Files specific to Samsung S3C24X0 CPUs
150 - arm925t Files specific to ARM 925 CPUs
151 - arm926ejs Files specific to ARM 926 CPUs
152 - arm1136 Files specific to ARM 1136 CPUs
153 - at32ap Files specific to Atmel AVR32 AP CPUs
154 - i386 Files specific to i386 CPUs
155 - ixp Files specific to Intel XScale IXP CPUs
156 - mcf52x2 Files specific to Freescale ColdFire MCF52x2 CPUs
157 - mcf5227x Files specific to Freescale ColdFire MCF5227x CPUs
158 - mcf532x Files specific to Freescale ColdFire MCF5329 CPUs
159 - mcf5445x Files specific to Freescale ColdFire MCF5445x CPUs
160 - mcf547x_8x Files specific to Freescale ColdFire MCF547x_8x CPUs
161 - mips Files specific to MIPS CPUs
162 - mpc5xx Files specific to Freescale MPC5xx CPUs
163 - mpc5xxx Files specific to Freescale MPC5xxx CPUs
164 - mpc8xx Files specific to Freescale MPC8xx CPUs
165 - mpc8220 Files specific to Freescale MPC8220 CPUs
166 - mpc824x Files specific to Freescale MPC824x CPUs
167 - mpc8260 Files specific to Freescale MPC8260 CPUs
168 - mpc85xx Files specific to Freescale MPC85xx CPUs
169 - nios Files specific to Altera NIOS CPUs
170 - nios2 Files specific to Altera Nios-II CPUs
171 - ppc4xx Files specific to AMCC PowerPC 4xx CPUs
172 - pxa Files specific to Intel XScale PXA CPUs
173 - s3c44b0 Files specific to Samsung S3C44B0 CPUs
174 - sa1100 Files specific to Intel StrongARM SA1100 CPUs
175 - disk Code for disk drive partition handling
176 - doc Documentation (don't expect too much)
177 - drivers Commonly used device drivers
178 - dtt Digital Thermometer and Thermostat drivers
179 - examples Example code for standalone applications, etc.
180 - include Header Files
181 - lib_arm Files generic to ARM architecture
182 - lib_avr32 Files generic to AVR32 architecture
183 - lib_generic Files generic to all architectures
184 - lib_i386 Files generic to i386 architecture
185 - lib_m68k Files generic to m68k architecture
186 - lib_mips Files generic to MIPS architecture
187 - lib_nios Files generic to NIOS architecture
188 - lib_ppc Files generic to PowerPC architecture
189 - libfdt Library files to support flattened device trees
190 - net Networking code
191 - post Power On Self Test
192 - rtc Real Time Clock drivers
193 - tools Tools to build S-Record or U-Boot images, etc.
195 Software Configuration:
196 =======================
198 Configuration is usually done using C preprocessor defines; the
199 rationale behind that is to avoid dead code whenever possible.
201 There are two classes of configuration variables:
203 * Configuration _OPTIONS_:
204 These are selectable by the user and have names beginning with
207 * Configuration _SETTINGS_:
208 These depend on the hardware etc. and should not be meddled with if
209 you don't know what you're doing; they have names beginning with
212 Later we will add a configuration tool - probably similar to or even
213 identical to what's used for the Linux kernel. Right now, we have to
214 do the configuration by hand, which means creating some symbolic
215 links and editing some configuration files. We use the TQM8xxL boards
219 Selection of Processor Architecture and Board Type:
220 ---------------------------------------------------
222 For all supported boards there are ready-to-use default
223 configurations available; just type "make <board_name>_config".
225 Example: For a TQM823L module type:
230 For the Cogent platform, you need to specify the cpu type as well;
231 e.g. "make cogent_mpc8xx_config". And also configure the cogent
232 directory according to the instructions in cogent/README.
235 Configuration Options:
236 ----------------------
238 Configuration depends on the combination of board and CPU type; all
239 such information is kept in a configuration file
240 "include/configs/<board_name>.h".
242 Example: For a TQM823L module, all configuration settings are in
243 "include/configs/TQM823L.h".
246 Many of the options are named exactly as the corresponding Linux
247 kernel configuration options. The intention is to make it easier to
248 build a config tool - later.
251 The following options need to be configured:
253 - CPU Type: Define exactly one, e.g. CONFIG_MPC85XX.
255 - Board Type: Define exactly one, e.g. CONFIG_MPC8540ADS.
257 - CPU Daughterboard Type: (if CONFIG_ATSTK1000 is defined)
258 Define exactly one, e.g. CONFIG_ATSTK1002
260 - CPU Module Type: (if CONFIG_COGENT is defined)
261 Define exactly one of
263 --- FIXME --- not tested yet:
264 CONFIG_CMA286_60, CONFIG_CMA286_21, CONFIG_CMA286_60P,
265 CONFIG_CMA287_23, CONFIG_CMA287_50
267 - Motherboard Type: (if CONFIG_COGENT is defined)
268 Define exactly one of
269 CONFIG_CMA101, CONFIG_CMA102
271 - Motherboard I/O Modules: (if CONFIG_COGENT is defined)
272 Define one or more of
275 - Motherboard Options: (if CONFIG_CMA101 or CONFIG_CMA102 are defined)
276 Define one or more of
277 CONFIG_LCD_HEARTBEAT - update a character position on
278 the lcd display every second with
281 - Board flavour: (if CONFIG_MPC8260ADS is defined)
284 CFG_8260ADS - original MPC8260ADS
285 CFG_8266ADS - MPC8266ADS
286 CFG_PQ2FADS - PQ2FADS-ZU or PQ2FADS-VR
287 CFG_8272ADS - MPC8272ADS
289 - MPC824X Family Member (if CONFIG_MPC824X is defined)
290 Define exactly one of
291 CONFIG_MPC8240, CONFIG_MPC8245
293 - 8xx CPU Options: (if using an MPC8xx cpu)
294 CONFIG_8xx_GCLK_FREQ - deprecated: CPU clock if
295 get_gclk_freq() cannot work
296 e.g. if there is no 32KHz
297 reference PIT/RTC clock
298 CONFIG_8xx_OSCLK - PLL input clock (either EXTCLK
301 - 859/866/885 CPU options: (if using a MPC859 or MPC866 or MPC885 CPU):
304 CONFIG_8xx_CPUCLK_DEFAULT
305 See doc/README.MPC866
309 Define this to measure the actual CPU clock instead
310 of relying on the correctness of the configured
311 values. Mostly useful for board bringup to make sure
312 the PLL is locked at the intended frequency. Note
313 that this requires a (stable) reference clock (32 kHz
314 RTC clock or CFG_8XX_XIN)
316 - Intel Monahans options:
317 CFG_MONAHANS_RUN_MODE_OSC_RATIO
319 Defines the Monahans run mode to oscillator
320 ratio. Valid values are 8, 16, 24, 31. The core
321 frequency is this value multiplied by 13 MHz.
323 CFG_MONAHANS_TURBO_RUN_MODE_RATIO
325 Defines the Monahans turbo mode to oscillator
326 ratio. Valid values are 1 (default if undefined) and
327 2. The core frequency as calculated above is multiplied
330 - Linux Kernel Interface:
333 U-Boot stores all clock information in Hz
334 internally. For binary compatibility with older Linux
335 kernels (which expect the clocks passed in the
336 bd_info data to be in MHz) the environment variable
337 "clocks_in_mhz" can be defined so that U-Boot
338 converts clock data to MHZ before passing it to the
340 When CONFIG_CLOCKS_IN_MHZ is defined, a definition of
341 "clocks_in_mhz=1" is automatically included in the
344 CONFIG_MEMSIZE_IN_BYTES [relevant for MIPS only]
346 When transfering memsize parameter to linux, some versions
347 expect it to be in bytes, others in MB.
348 Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes.
350 CONFIG_OF_LIBFDT / CONFIG_OF_FLAT_TREE
352 New kernel versions are expecting firmware settings to be
353 passed using flattened device trees (based on open firmware
357 * New libfdt-based support
358 * Adds the "fdt" command
359 * The bootm command automatically updates the fdt
362 * Deprecated, see CONFIG_OF_LIBFDT
363 * Original ft_build.c-based support
364 * Automatically modifies the dft as part of the bootm command
365 * The environment variable "disable_of", when set,
366 disables this functionality.
368 OF_CPU - The proper name of the cpus node.
369 OF_SOC - The proper name of the soc node.
370 OF_TBCLK - The timebase frequency.
371 OF_STDOUT_PATH - The path to the console device
373 boards with QUICC Engines require OF_QE to set UCC mac addresses
377 * CONFIG_OF_LIBFDT - enables the "fdt bd_t" command
378 * CONFIG_OF_FLAT_TREE - The resulting flat device tree
379 will have a copy of the bd_t. Space should be
380 pre-allocated in the dts for the bd_t.
382 CONFIG_OF_HAS_UBOOT_ENV
384 * CONFIG_OF_LIBFDT - enables the "fdt env" command
385 * CONFIG_OF_FLAT_TREE - The resulting flat device tree
386 will have a copy of u-boot's environment variables
388 CONFIG_OF_BOARD_SETUP
390 Board code has addition modification that it wants to make
391 to the flat device tree before handing it off to the kernel
395 This define fills in the correct boot cpu in the boot
396 param header, the default value is zero if undefined.
401 Define this if you want support for Amba PrimeCell PL010 UARTs.
405 Define this if you want support for Amba PrimeCell PL011 UARTs.
409 If you have Amba PrimeCell PL011 UARTs, set this variable to
410 the clock speed of the UARTs.
414 If you have Amba PrimeCell PL010 or PL011 UARTs on your board,
415 define this to a list of base addresses for each (supported)
416 port. See e.g. include/configs/versatile.h
420 Depending on board, define exactly one serial port
421 (like CONFIG_8xx_CONS_SMC1, CONFIG_8xx_CONS_SMC2,
422 CONFIG_8xx_CONS_SCC1, ...), or switch off the serial
423 console by defining CONFIG_8xx_CONS_NONE
425 Note: if CONFIG_8xx_CONS_NONE is defined, the serial
426 port routines must be defined elsewhere
427 (i.e. serial_init(), serial_getc(), ...)
430 Enables console device for a color framebuffer. Needs following
431 defines (cf. smiLynxEM, i8042, board/eltec/bab7xx)
432 VIDEO_FB_LITTLE_ENDIAN graphic memory organisation
434 VIDEO_HW_RECTFILL graphic chip supports
437 VIDEO_HW_BITBLT graphic chip supports
438 bit-blit (cf. smiLynxEM)
439 VIDEO_VISIBLE_COLS visible pixel columns
441 VIDEO_VISIBLE_ROWS visible pixel rows
442 VIDEO_PIXEL_SIZE bytes per pixel
443 VIDEO_DATA_FORMAT graphic data format
444 (0-5, cf. cfb_console.c)
445 VIDEO_FB_ADRS framebuffer address
446 VIDEO_KBD_INIT_FCT keyboard int fct
447 (i.e. i8042_kbd_init())
448 VIDEO_TSTC_FCT test char fct
450 VIDEO_GETC_FCT get char fct
452 CONFIG_CONSOLE_CURSOR cursor drawing on/off
453 (requires blink timer
455 CFG_CONSOLE_BLINK_COUNT blink interval (cf. i8042.c)
456 CONFIG_CONSOLE_TIME display time/date info in
458 (requires CONFIG_CMD_DATE)
459 CONFIG_VIDEO_LOGO display Linux logo in
461 CONFIG_VIDEO_BMP_LOGO use bmp_logo.h instead of
462 linux_logo.h for logo.
463 Requires CONFIG_VIDEO_LOGO
464 CONFIG_CONSOLE_EXTRA_INFO
465 addional board info beside
468 When CONFIG_CFB_CONSOLE is defined, video console is
469 default i/o. Serial console can be forced with
470 environment 'console=serial'.
472 When CONFIG_SILENT_CONSOLE is defined, all console
473 messages (by U-Boot and Linux!) can be silenced with
474 the "silent" environment variable. See
475 doc/README.silent for more information.
478 CONFIG_BAUDRATE - in bps
479 Select one of the baudrates listed in
480 CFG_BAUDRATE_TABLE, see below.
481 CFG_BRGCLK_PRESCALE, baudrate prescale
483 - Interrupt driven serial port input:
484 CONFIG_SERIAL_SOFTWARE_FIFO
487 Use an interrupt handler for receiving data on the
488 serial port. It also enables using hardware handshake
489 (RTS/CTS) and UART's built-in FIFO. Set the number of
490 bytes the interrupt driven input buffer should have.
492 Leave undefined to disable this feature, including
493 disable the buffer and hardware handshake.
495 - Console UART Number:
499 If defined internal UART1 (and not UART0) is used
500 as default U-Boot console.
502 - Boot Delay: CONFIG_BOOTDELAY - in seconds
503 Delay before automatically booting the default image;
504 set to -1 to disable autoboot.
506 See doc/README.autoboot for these options that
507 work with CONFIG_BOOTDELAY. None are required.
508 CONFIG_BOOT_RETRY_TIME
509 CONFIG_BOOT_RETRY_MIN
510 CONFIG_AUTOBOOT_KEYED
511 CONFIG_AUTOBOOT_PROMPT
512 CONFIG_AUTOBOOT_DELAY_STR
513 CONFIG_AUTOBOOT_STOP_STR
514 CONFIG_AUTOBOOT_DELAY_STR2
515 CONFIG_AUTOBOOT_STOP_STR2
516 CONFIG_ZERO_BOOTDELAY_CHECK
517 CONFIG_RESET_TO_RETRY
521 Only needed when CONFIG_BOOTDELAY is enabled;
522 define a command string that is automatically executed
523 when no character is read on the console interface
524 within "Boot Delay" after reset.
527 This can be used to pass arguments to the bootm
528 command. The value of CONFIG_BOOTARGS goes into the
529 environment value "bootargs".
531 CONFIG_RAMBOOT and CONFIG_NFSBOOT
532 The value of these goes into the environment as
533 "ramboot" and "nfsboot" respectively, and can be used
534 as a convenience, when switching between booting from
540 When this option is #defined, the existence of the
541 environment variable "preboot" will be checked
542 immediately before starting the CONFIG_BOOTDELAY
543 countdown and/or running the auto-boot command resp.
544 entering interactive mode.
546 This feature is especially useful when "preboot" is
547 automatically generated or modified. For an example
548 see the LWMON board specific code: here "preboot" is
549 modified when the user holds down a certain
550 combination of keys on the (special) keyboard when
553 - Serial Download Echo Mode:
555 If defined to 1, all characters received during a
556 serial download (using the "loads" command) are
557 echoed back. This might be needed by some terminal
558 emulations (like "cu"), but may as well just take
559 time on others. This setting #define's the initial
560 value of the "loads_echo" environment variable.
562 - Kgdb Serial Baudrate: (if CONFIG_CMD_KGDB is defined)
564 Select one of the baudrates listed in
565 CFG_BAUDRATE_TABLE, see below.
568 Monitor commands can be included or excluded
569 from the build by using the #include files
570 "config_cmd_all.h" and #undef'ing unwanted
571 commands, or using "config_cmd_default.h"
572 and augmenting with additional #define's
575 The default command configuration includes all commands
576 except those marked below with a "*".
578 CONFIG_CMD_ASKENV * ask for env variable
579 CONFIG_CMD_AUTOSCRIPT Autoscript Support
580 CONFIG_CMD_BDI bdinfo
581 CONFIG_CMD_BEDBUG * Include BedBug Debugger
582 CONFIG_CMD_BMP * BMP support
583 CONFIG_CMD_BSP * Board specific commands
584 CONFIG_CMD_BOOTD bootd
585 CONFIG_CMD_CACHE * icache, dcache
586 CONFIG_CMD_CONSOLE coninfo
587 CONFIG_CMD_DATE * support for RTC, date/time...
588 CONFIG_CMD_DHCP * DHCP support
589 CONFIG_CMD_DIAG * Diagnostics
590 CONFIG_CMD_DOC * Disk-On-Chip Support
591 CONFIG_CMD_DTT * Digital Therm and Thermostat
592 CONFIG_CMD_ECHO echo arguments
593 CONFIG_CMD_EEPROM * EEPROM read/write support
594 CONFIG_CMD_ELF * bootelf, bootvx
595 CONFIG_CMD_ENV saveenv
596 CONFIG_CMD_FDC * Floppy Disk Support
597 CONFIG_CMD_FAT * FAT partition support
598 CONFIG_CMD_FDOS * Dos diskette Support
599 CONFIG_CMD_FLASH flinfo, erase, protect
600 CONFIG_CMD_FPGA FPGA device initialization support
601 CONFIG_CMD_HWFLOW * RTS/CTS hw flow control
602 CONFIG_CMD_I2C * I2C serial bus support
603 CONFIG_CMD_IDE * IDE harddisk support
604 CONFIG_CMD_IMI iminfo
605 CONFIG_CMD_IMLS List all found images
606 CONFIG_CMD_IMMAP * IMMR dump support
607 CONFIG_CMD_IRQ * irqinfo
608 CONFIG_CMD_ITEST Integer/string test of 2 values
609 CONFIG_CMD_JFFS2 * JFFS2 Support
610 CONFIG_CMD_KGDB * kgdb
611 CONFIG_CMD_LOADB loadb
612 CONFIG_CMD_LOADS loads
613 CONFIG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base,
615 CONFIG_CMD_MISC Misc functions like sleep etc
616 CONFIG_CMD_MMC * MMC memory mapped support
617 CONFIG_CMD_MII * MII utility commands
618 CONFIG_CMD_NAND * NAND support
619 CONFIG_CMD_NET bootp, tftpboot, rarpboot
620 CONFIG_CMD_PCI * pciinfo
621 CONFIG_CMD_PCMCIA * PCMCIA support
622 CONFIG_CMD_PING * send ICMP ECHO_REQUEST to network
624 CONFIG_CMD_PORTIO * Port I/O
625 CONFIG_CMD_REGINFO * Register dump
626 CONFIG_CMD_RUN run command in env variable
627 CONFIG_CMD_SAVES * save S record dump
628 CONFIG_CMD_SCSI * SCSI Support
629 CONFIG_CMD_SDRAM * print SDRAM configuration information
630 (requires CONFIG_CMD_I2C)
631 CONFIG_CMD_SETGETDCR Support for DCR Register access
633 CONFIG_CMD_SPI * SPI serial bus support
634 CONFIG_CMD_USB * USB support
635 CONFIG_CMD_VFD * VFD support (TRAB)
636 CONFIG_CMD_BSP * Board SPecific functions
637 CONFIG_CMD_CDP * Cisco Discover Protocol support
638 CONFIG_CMD_FSL * Microblaze FSL support
641 EXAMPLE: If you want all functions except of network
642 support you can write:
644 #include "config_cmd_all.h"
645 #undef CONFIG_CMD_NET
648 fdt (flattened device tree) command: CONFIG_OF_LIBFDT
650 Note: Don't enable the "icache" and "dcache" commands
651 (configuration option CONFIG_CMD_CACHE) unless you know
652 what you (and your U-Boot users) are doing. Data
653 cache cannot be enabled on systems like the 8xx or
654 8260 (where accesses to the IMMR region must be
655 uncached), and it cannot be disabled on all other
656 systems where we (mis-) use the data cache to hold an
657 initial stack and some data.
660 XXX - this list needs to get updated!
664 If this variable is defined, it enables watchdog
665 support. There must be support in the platform specific
666 code for a watchdog. For the 8xx and 8260 CPUs, the
667 SIU Watchdog feature is enabled in the SYPCR
671 CONFIG_VERSION_VARIABLE
672 If this variable is defined, an environment variable
673 named "ver" is created by U-Boot showing the U-Boot
674 version as printed by the "version" command.
675 This variable is readonly.
679 When CONFIG_CMD_DATE is selected, the type of the RTC
680 has to be selected, too. Define exactly one of the
683 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx
684 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC
685 CONFIG_RTC_MC146818 - use MC146818 RTC
686 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC
687 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC
688 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC
689 CONFIG_RTC_DS164x - use Dallas DS164x RTC
690 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC
691 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC
692 CFG_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337
694 Note that if the RTC uses I2C, then the I2C interface
695 must also be configured. See I2C Support, below.
699 When CONFIG_TIMESTAMP is selected, the timestamp
700 (date and time) of an image is printed by image
701 commands like bootm or iminfo. This option is
702 automatically enabled when you select CONFIG_CMD_DATE .
705 CONFIG_MAC_PARTITION and/or CONFIG_DOS_PARTITION
706 and/or CONFIG_ISO_PARTITION
708 If IDE or SCSI support is enabled (CONFIG_CMD_IDE or
709 CONFIG_CMD_SCSI) you must configure support for at
710 least one partition type as well.
713 CONFIG_IDE_RESET_ROUTINE - this is defined in several
714 board configurations files but used nowhere!
716 CONFIG_IDE_RESET - is this is defined, IDE Reset will
717 be performed by calling the function
718 ide_set_reset(int reset)
719 which has to be defined in a board specific file
724 Set this to enable ATAPI support.
729 Set this to enable support for disks larger than 137GB
730 Also look at CFG_64BIT_LBA ,CFG_64BIT_VSPRINTF and CFG_64BIT_STRTOUL
731 Whithout these , LBA48 support uses 32bit variables and will 'only'
732 support disks up to 2.1TB.
735 When enabled, makes the IDE subsystem use 64bit sector addresses.
739 At the moment only there is only support for the
740 SYM53C8XX SCSI controller; define
741 CONFIG_SCSI_SYM53C8XX to enable it.
743 CFG_SCSI_MAX_LUN [8], CFG_SCSI_MAX_SCSI_ID [7] and
744 CFG_SCSI_MAX_DEVICE [CFG_SCSI_MAX_SCSI_ID *
745 CFG_SCSI_MAX_LUN] can be adjusted to define the
746 maximum numbers of LUNs, SCSI ID's and target
748 CFG_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz)
750 - NETWORK Support (PCI):
752 Support for Intel 8254x gigabit chips.
755 Support for Intel 82557/82559/82559ER chips.
756 Optional CONFIG_EEPRO100_SROM_WRITE enables eeprom
757 write routine for first time initialisation.
760 Support for Digital 2114x chips.
761 Optional CONFIG_TULIP_SELECT_MEDIA for board specific
762 modem chip initialisation (KS8761/QS6611).
765 Support for National dp83815 chips.
768 Support for National dp8382[01] gigabit chips.
770 - NETWORK Support (other):
772 CONFIG_DRIVER_LAN91C96
773 Support for SMSC's LAN91C96 chips.
776 Define this to hold the physical address
777 of the LAN91C96's I/O space
779 CONFIG_LAN91C96_USE_32_BIT
780 Define this to enable 32 bit addressing
782 CONFIG_DRIVER_SMC91111
783 Support for SMSC's LAN91C111 chip
786 Define this to hold the physical address
787 of the device (I/O space)
789 CONFIG_SMC_USE_32_BIT
790 Define this if data bus is 32 bits
792 CONFIG_SMC_USE_IOFUNCS
793 Define this to use i/o functions instead of macros
794 (some hardware wont work with macros)
797 At the moment only the UHCI host controller is
798 supported (PIP405, MIP405, MPC5200); define
799 CONFIG_USB_UHCI to enable it.
800 define CONFIG_USB_KEYBOARD to enable the USB Keyboard
801 and define CONFIG_USB_STORAGE to enable the USB
804 Supported are USB Keyboards and USB Floppy drives
806 MPC5200 USB requires additional defines:
808 for 528 MHz Clock: 0x0001bbbb
810 for differential drivers: 0x00001000
811 for single ended drivers: 0x00005000
813 May be defined to allow interrupt polling
814 instead of using asynchronous interrupts
817 Define the below if you wish to use the USB console.
818 Once firmware is rebuilt from a serial console issue the
819 command "setenv stdin usbtty; setenv stdout usbtty" and
820 attach your usb cable. The Unix command "dmesg" should print
821 it has found a new device. The environment variable usbtty
822 can be set to gserial or cdc_acm to enable your device to
823 appear to a USB host as a Linux gserial device or a
824 Common Device Class Abstract Control Model serial device.
825 If you select usbtty = gserial you should be able to enumerate
827 # modprobe usbserial vendor=0xVendorID product=0xProductID
828 else if using cdc_acm, simply setting the environment
829 variable usbtty to be cdc_acm should suffice. The following
830 might be defined in YourBoardName.h
833 Define this to build a UDC device
836 Define this to have a tty type of device available to
837 talk to the UDC device
839 CFG_CONSOLE_IS_IN_ENV
840 Define this if you want stdin, stdout &/or stderr to
844 CFG_USB_EXTC_CLK 0xBLAH
845 Derive USB clock from external clock "blah"
846 - CFG_USB_EXTC_CLK 0x02
848 CFG_USB_BRG_CLK 0xBLAH
849 Derive USB clock from brgclk
850 - CFG_USB_BRG_CLK 0x04
852 If you have a USB-IF assigned VendorID then you may wish to
853 define your own vendor specific values either in BoardName.h
854 or directly in usbd_vendor_info.h. If you don't define
855 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME,
856 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot
857 should pretend to be a Linux device to it's target host.
859 CONFIG_USBD_MANUFACTURER
860 Define this string as the name of your company for
861 - CONFIG_USBD_MANUFACTURER "my company"
863 CONFIG_USBD_PRODUCT_NAME
864 Define this string as the name of your product
865 - CONFIG_USBD_PRODUCT_NAME "acme usb device"
868 Define this as your assigned Vendor ID from the USB
869 Implementors Forum. This *must* be a genuine Vendor ID
870 to avoid polluting the USB namespace.
871 - CONFIG_USBD_VENDORID 0xFFFF
873 CONFIG_USBD_PRODUCTID
874 Define this as the unique Product ID
876 - CONFIG_USBD_PRODUCTID 0xFFFF
880 The MMC controller on the Intel PXA is supported. To
881 enable this define CONFIG_MMC. The MMC can be
882 accessed from the boot prompt by mapping the device
883 to physical memory similar to flash. Command line is
884 enabled with CONFIG_CMD_MMC. The MMC driver also works with
885 the FAT fs. This is enabled with CONFIG_CMD_FAT.
887 - Journaling Flash filesystem support:
888 CONFIG_JFFS2_NAND, CONFIG_JFFS2_NAND_OFF, CONFIG_JFFS2_NAND_SIZE,
889 CONFIG_JFFS2_NAND_DEV
890 Define these for a default partition on a NAND device
892 CFG_JFFS2_FIRST_SECTOR,
893 CFG_JFFS2_FIRST_BANK, CFG_JFFS2_NUM_BANKS
894 Define these for a default partition on a NOR device
897 Define this to create an own partition. You have to provide a
898 function struct part_info* jffs2_part_info(int part_num)
900 If you define only one JFFS2 partition you may also want to
901 #define CFG_JFFS_SINGLE_PART 1
902 to disable the command chpart. This is the default when you
903 have not defined a custom partition
908 Define this to enable standard (PC-Style) keyboard
912 Standard PC keyboard driver with US (is default) and
913 GERMAN key layout (switch via environment 'keymap=de') support.
914 Export function i8042_kbd_init, i8042_tstc and i8042_getc
915 for cfb_console. Supports cursor blinking.
920 Define this to enable video support (for output to
925 Enable Chips & Technologies 69000 Video chip
927 CONFIG_VIDEO_SMI_LYNXEM
928 Enable Silicon Motion SMI 712/710/810 Video chip. The
929 video output is selected via environment 'videoout'
930 (1 = LCD and 2 = CRT). If videoout is undefined, CRT is
933 For the CT69000 and SMI_LYNXEM drivers, videomode is
934 selected via environment 'videomode'. Two diferent ways
936 - "videomode=num" 'num' is a standard LiLo mode numbers.
937 Following standard modes are supported (* is default):
939 Colors 640x480 800x600 1024x768 1152x864 1280x1024
940 -------------+---------------------------------------------
941 8 bits | 0x301* 0x303 0x305 0x161 0x307
942 15 bits | 0x310 0x313 0x316 0x162 0x319
943 16 bits | 0x311 0x314 0x317 0x163 0x31A
944 24 bits | 0x312 0x315 0x318 ? 0x31B
945 -------------+---------------------------------------------
946 (i.e. setenv videomode 317; saveenv; reset;)
948 - "videomode=bootargs" all the video parameters are parsed
949 from the bootargs. (See drivers/video/videomodes.c)
952 CONFIG_VIDEO_SED13806
953 Enable Epson SED13806 driver. This driver supports 8bpp
954 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP
955 or CONFIG_VIDEO_SED13806_16BPP
960 Define this to enable a custom keyboard support.
961 This simply calls drv_keyboard_init() which must be
962 defined in your board-specific files.
963 The only board using this so far is RBC823.
965 - LCD Support: CONFIG_LCD
967 Define this to enable LCD support (for output to LCD
968 display); also select one of the supported displays
969 by defining one of these:
971 CONFIG_NEC_NL6448AC33:
973 NEC NL6448AC33-18. Active, color, single scan.
975 CONFIG_NEC_NL6448BC20
977 NEC NL6448BC20-08. 6.5", 640x480.
978 Active, color, single scan.
980 CONFIG_NEC_NL6448BC33_54
982 NEC NL6448BC33-54. 10.4", 640x480.
983 Active, color, single scan.
987 Sharp 320x240. Active, color, single scan.
988 It isn't 16x9, and I am not sure what it is.
990 CONFIG_SHARP_LQ64D341
992 Sharp LQ64D341 display, 640x480.
993 Active, color, single scan.
997 HLD1045 display, 640x480.
998 Active, color, single scan.
1002 Optrex CBL50840-2 NF-FW 99 22 M5
1004 Hitachi LMG6912RPFC-00T
1008 320x240. Black & white.
1010 Normally display is black on white background; define
1011 CFG_WHITE_ON_BLACK to get it inverted.
1013 - Splash Screen Support: CONFIG_SPLASH_SCREEN
1015 If this option is set, the environment is checked for
1016 a variable "splashimage". If found, the usual display
1017 of logo, copyright and system information on the LCD
1018 is suppressed and the BMP image at the address
1019 specified in "splashimage" is loaded instead. The
1020 console is redirected to the "nulldev", too. This
1021 allows for a "silent" boot where a splash screen is
1022 loaded very quickly after power-on.
1024 - Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP
1026 If this option is set, additionally to standard BMP
1027 images, gzipped BMP images can be displayed via the
1028 splashscreen support or the bmp command.
1030 - Compression support:
1033 If this option is set, support for bzip2 compressed
1034 images is included. If not, only uncompressed and gzip
1035 compressed images are supported.
1037 NOTE: the bzip2 algorithm requires a lot of RAM, so
1038 the malloc area (as defined by CFG_MALLOC_LEN) should
1044 The address of PHY on MII bus.
1046 CONFIG_PHY_CLOCK_FREQ (ppc4xx)
1048 The clock frequency of the MII bus
1052 If this option is set, support for speed/duplex
1053 detection of Gigabit PHY is included.
1055 CONFIG_PHY_RESET_DELAY
1057 Some PHY like Intel LXT971A need extra delay after
1058 reset before any MII register access is possible.
1059 For such PHY, set this option to the usec delay
1060 required. (minimum 300usec for LXT971A)
1062 CONFIG_PHY_CMD_DELAY (ppc4xx)
1064 Some PHY like Intel LXT971A need extra delay after
1065 command issued before MII status register can be read
1072 Define a default value for ethernet address to use
1073 for the respective ethernet interface, in case this
1074 is not determined automatically.
1079 Define a default value for the IP address to use for
1080 the default ethernet interface, in case this is not
1081 determined through e.g. bootp.
1083 - Server IP address:
1086 Defines a default value for theIP address of a TFTP
1087 server to contact when using the "tftboot" command.
1089 - Multicast TFTP Mode:
1092 Defines whether you want to support multicast TFTP as per
1093 rfc-2090; for example to work with atftp. Lets lots of targets
1094 tftp down the same boot image concurrently. Note: the ethernet
1095 driver in use must provide a function: mcast() to join/leave a
1098 CONFIG_BOOTP_RANDOM_DELAY
1099 - BOOTP Recovery Mode:
1100 CONFIG_BOOTP_RANDOM_DELAY
1102 If you have many targets in a network that try to
1103 boot using BOOTP, you may want to avoid that all
1104 systems send out BOOTP requests at precisely the same
1105 moment (which would happen for instance at recovery
1106 from a power failure, when all systems will try to
1107 boot, thus flooding the BOOTP server. Defining
1108 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
1109 inserted before sending out BOOTP requests. The
1110 following delays are inserted then:
1112 1st BOOTP request: delay 0 ... 1 sec
1113 2nd BOOTP request: delay 0 ... 2 sec
1114 3rd BOOTP request: delay 0 ... 4 sec
1116 BOOTP requests: delay 0 ... 8 sec
1118 - DHCP Advanced Options:
1119 You can fine tune the DHCP functionality by defining
1120 CONFIG_BOOTP_* symbols:
1122 CONFIG_BOOTP_SUBNETMASK
1123 CONFIG_BOOTP_GATEWAY
1124 CONFIG_BOOTP_HOSTNAME
1125 CONFIG_BOOTP_NISDOMAIN
1126 CONFIG_BOOTP_BOOTPATH
1127 CONFIG_BOOTP_BOOTFILESIZE
1130 CONFIG_BOOTP_SEND_HOSTNAME
1131 CONFIG_BOOTP_NTPSERVER
1132 CONFIG_BOOTP_TIMEOFFSET
1133 CONFIG_BOOTP_VENDOREX
1135 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip
1136 environment variable, not the BOOTP server.
1138 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS
1139 serverip from a DHCP server, it is possible that more
1140 than one DNS serverip is offered to the client.
1141 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS
1142 serverip will be stored in the additional environment
1143 variable "dnsip2". The first DNS serverip is always
1144 stored in the variable "dnsip", when CONFIG_BOOTP_DNS
1147 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable
1148 to do a dynamic update of a DNS server. To do this, they
1149 need the hostname of the DHCP requester.
1150 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content
1151 of the "hostname" environment variable is passed as
1152 option 12 to the DHCP server.
1155 CONFIG_CDP_DEVICE_ID
1157 The device id used in CDP trigger frames.
1159 CONFIG_CDP_DEVICE_ID_PREFIX
1161 A two character string which is prefixed to the MAC address
1166 A printf format string which contains the ascii name of
1167 the port. Normally is set to "eth%d" which sets
1168 eth0 for the first ethernet, eth1 for the second etc.
1170 CONFIG_CDP_CAPABILITIES
1172 A 32bit integer which indicates the device capabilities;
1173 0x00000010 for a normal host which does not forwards.
1177 An ascii string containing the version of the software.
1181 An ascii string containing the name of the platform.
1185 A 32bit integer sent on the trigger.
1187 CONFIG_CDP_POWER_CONSUMPTION
1189 A 16bit integer containing the power consumption of the
1190 device in .1 of milliwatts.
1192 CONFIG_CDP_APPLIANCE_VLAN_TYPE
1194 A byte containing the id of the VLAN.
1196 - Status LED: CONFIG_STATUS_LED
1198 Several configurations allow to display the current
1199 status using a LED. For instance, the LED will blink
1200 fast while running U-Boot code, stop blinking as
1201 soon as a reply to a BOOTP request was received, and
1202 start blinking slow once the Linux kernel is running
1203 (supported by a status LED driver in the Linux
1204 kernel). Defining CONFIG_STATUS_LED enables this
1207 - CAN Support: CONFIG_CAN_DRIVER
1209 Defining CONFIG_CAN_DRIVER enables CAN driver support
1210 on those systems that support this (optional)
1211 feature, like the TQM8xxL modules.
1213 - I2C Support: CONFIG_HARD_I2C | CONFIG_SOFT_I2C
1215 These enable I2C serial bus commands. Defining either of
1216 (but not both of) CONFIG_HARD_I2C or CONFIG_SOFT_I2C will
1217 include the appropriate I2C driver for the selected cpu.
1219 This will allow you to use i2c commands at the u-boot
1220 command line (as long as you set CONFIG_CMD_I2C in
1221 CONFIG_COMMANDS) and communicate with i2c based realtime
1222 clock chips. See common/cmd_i2c.c for a description of the
1223 command line interface.
1225 CONFIG_I2C_CMD_TREE is a recommended option that places
1226 all I2C commands under a single 'i2c' root command. The
1227 older 'imm', 'imd', 'iprobe' etc. commands are considered
1228 deprecated and may disappear in the future.
1230 CONFIG_HARD_I2C selects a hardware I2C controller.
1232 CONFIG_SOFT_I2C configures u-boot to use a software (aka
1233 bit-banging) driver instead of CPM or similar hardware
1236 There are several other quantities that must also be
1237 defined when you define CONFIG_HARD_I2C or CONFIG_SOFT_I2C.
1239 In both cases you will need to define CFG_I2C_SPEED
1240 to be the frequency (in Hz) at which you wish your i2c bus
1241 to run and CFG_I2C_SLAVE to be the address of this node (ie
1242 the cpu's i2c node address).
1244 Now, the u-boot i2c code for the mpc8xx (cpu/mpc8xx/i2c.c)
1245 sets the cpu up as a master node and so its address should
1246 therefore be cleared to 0 (See, eg, MPC823e User's Manual
1247 p.16-473). So, set CFG_I2C_SLAVE to 0.
1249 That's all that's required for CONFIG_HARD_I2C.
1251 If you use the software i2c interface (CONFIG_SOFT_I2C)
1252 then the following macros need to be defined (examples are
1253 from include/configs/lwmon.h):
1257 (Optional). Any commands necessary to enable the I2C
1258 controller or configure ports.
1260 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
1264 (Only for MPC8260 CPU). The I/O port to use (the code
1265 assumes both bits are on the same port). Valid values
1266 are 0..3 for ports A..D.
1270 The code necessary to make the I2C data line active
1271 (driven). If the data line is open collector, this
1274 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
1278 The code necessary to make the I2C data line tri-stated
1279 (inactive). If the data line is open collector, this
1282 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
1286 Code that returns TRUE if the I2C data line is high,
1289 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
1293 If <bit> is TRUE, sets the I2C data line high. If it
1294 is FALSE, it clears it (low).
1296 eg: #define I2C_SDA(bit) \
1297 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
1298 else immr->im_cpm.cp_pbdat &= ~PB_SDA
1302 If <bit> is TRUE, sets the I2C clock line high. If it
1303 is FALSE, it clears it (low).
1305 eg: #define I2C_SCL(bit) \
1306 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
1307 else immr->im_cpm.cp_pbdat &= ~PB_SCL
1311 This delay is invoked four times per clock cycle so this
1312 controls the rate of data transfer. The data rate thus
1313 is 1 / (I2C_DELAY * 4). Often defined to be something
1316 #define I2C_DELAY udelay(2)
1320 When a board is reset during an i2c bus transfer
1321 chips might think that the current transfer is still
1322 in progress. On some boards it is possible to access
1323 the i2c SCLK line directly, either by using the
1324 processor pin as a GPIO or by having a second pin
1325 connected to the bus. If this option is defined a
1326 custom i2c_init_board() routine in boards/xxx/board.c
1327 is run early in the boot sequence.
1329 CONFIG_I2CFAST (PPC405GP|PPC405EP only)
1331 This option enables configuration of bi_iic_fast[] flags
1332 in u-boot bd_info structure based on u-boot environment
1333 variable "i2cfast". (see also i2cfast)
1335 CONFIG_I2C_MULTI_BUS
1337 This option allows the use of multiple I2C buses, each of which
1338 must have a controller. At any point in time, only one bus is
1339 active. To switch to a different bus, use the 'i2c dev' command.
1340 Note that bus numbering is zero-based.
1344 This option specifies a list of I2C devices that will be skipped
1345 when the 'i2c probe' command is issued (or 'iprobe' using the legacy
1346 command). If CONFIG_I2C_MULTI_BUS is set, specify a list of bus-device
1347 pairs. Otherwise, specify a 1D array of device addresses
1350 #undef CONFIG_I2C_MULTI_BUS
1351 #define CFG_I2C_NOPROBES {0x50,0x68}
1353 will skip addresses 0x50 and 0x68 on a board with one I2C bus
1355 #define CONFIG_I2C_MULTI_BUS
1356 #define CFG_I2C_MULTI_NOPROBES {{0,0x50},{0,0x68},{1,0x54}}
1358 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1
1362 If defined, then this indicates the I2C bus number for DDR SPD.
1363 If not defined, then U-Boot assumes that SPD is on I2C bus 0.
1367 If defined, then this indicates the I2C bus number for the RTC.
1368 If not defined, then U-Boot assumes that RTC is on I2C bus 0.
1372 If defined, then this indicates the I2C bus number for the DTT.
1373 If not defined, then U-Boot assumes that DTT is on I2C bus 0.
1377 Define this option if you want to use Freescale's I2C driver in
1378 drivers/i2c/fsl_i2c.c.
1381 - SPI Support: CONFIG_SPI
1383 Enables SPI driver (so far only tested with
1384 SPI EEPROM, also an instance works with Crystal A/D and
1385 D/As on the SACSng board)
1389 Enables extended (16-bit) SPI EEPROM addressing.
1390 (symmetrical to CONFIG_I2C_X)
1394 Enables a software (bit-bang) SPI driver rather than
1395 using hardware support. This is a general purpose
1396 driver that only requires three general I/O port pins
1397 (two outputs, one input) to function. If this is
1398 defined, the board configuration must define several
1399 SPI configuration items (port pins to use, etc). For
1400 an example, see include/configs/sacsng.h.
1404 Enables a hardware SPI driver for general-purpose reads
1405 and writes. As with CONFIG_SOFT_SPI, the board configuration
1406 must define a list of chip-select function pointers.
1407 Currently supported on some MPC8xxx processors. For an
1408 example, see include/configs/mpc8349emds.h.
1410 - FPGA Support: CONFIG_FPGA
1412 Enables FPGA subsystem.
1414 CONFIG_FPGA_<vendor>
1416 Enables support for specific chip vendors.
1419 CONFIG_FPGA_<family>
1421 Enables support for FPGA family.
1422 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX)
1426 Specify the number of FPGA devices to support.
1428 CFG_FPGA_PROG_FEEDBACK
1430 Enable printing of hash marks during FPGA configuration.
1434 Enable checks on FPGA configuration interface busy
1435 status by the configuration function. This option
1436 will require a board or device specific function to
1441 If defined, a function that provides delays in the FPGA
1442 configuration driver.
1444 CFG_FPGA_CHECK_CTRLC
1445 Allow Control-C to interrupt FPGA configuration
1447 CFG_FPGA_CHECK_ERROR
1449 Check for configuration errors during FPGA bitfile
1450 loading. For example, abort during Virtex II
1451 configuration if the INIT_B line goes low (which
1452 indicated a CRC error).
1456 Maximum time to wait for the INIT_B line to deassert
1457 after PROB_B has been deasserted during a Virtex II
1458 FPGA configuration sequence. The default time is 500
1463 Maximum time to wait for BUSY to deassert during
1464 Virtex II FPGA configuration. The default is 5 mS.
1466 CFG_FPGA_WAIT_CONFIG
1468 Time to wait after FPGA configuration. The default is
1471 - Configuration Management:
1474 If defined, this string will be added to the U-Boot
1475 version information (U_BOOT_VERSION)
1477 - Vendor Parameter Protection:
1479 U-Boot considers the values of the environment
1480 variables "serial#" (Board Serial Number) and
1481 "ethaddr" (Ethernet Address) to be parameters that
1482 are set once by the board vendor / manufacturer, and
1483 protects these variables from casual modification by
1484 the user. Once set, these variables are read-only,
1485 and write or delete attempts are rejected. You can
1486 change this behviour:
1488 If CONFIG_ENV_OVERWRITE is #defined in your config
1489 file, the write protection for vendor parameters is
1490 completely disabled. Anybody can change or delete
1493 Alternatively, if you #define _both_ CONFIG_ETHADDR
1494 _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
1495 ethernet address is installed in the environment,
1496 which can be changed exactly ONCE by the user. [The
1497 serial# is unaffected by this, i. e. it remains
1503 Define this variable to enable the reservation of
1504 "protected RAM", i. e. RAM which is not overwritten
1505 by U-Boot. Define CONFIG_PRAM to hold the number of
1506 kB you want to reserve for pRAM. You can overwrite
1507 this default value by defining an environment
1508 variable "pram" to the number of kB you want to
1509 reserve. Note that the board info structure will
1510 still show the full amount of RAM. If pRAM is
1511 reserved, a new environment variable "mem" will
1512 automatically be defined to hold the amount of
1513 remaining RAM in a form that can be passed as boot
1514 argument to Linux, for instance like that:
1516 setenv bootargs ... mem=\${mem}
1519 This way you can tell Linux not to use this memory,
1520 either, which results in a memory region that will
1521 not be affected by reboots.
1523 *WARNING* If your board configuration uses automatic
1524 detection of the RAM size, you must make sure that
1525 this memory test is non-destructive. So far, the
1526 following board configurations are known to be
1529 ETX094, IVMS8, IVML24, SPD8xx, TQM8xxL,
1530 HERMES, IP860, RPXlite, LWMON, LANTEC,
1531 PCU_E, FLAGADM, TQM8260
1536 Define this variable to stop the system in case of a
1537 fatal error, so that you have to reset it manually.
1538 This is probably NOT a good idea for an embedded
1539 system where you want to system to reboot
1540 automatically as fast as possible, but it may be
1541 useful during development since you can try to debug
1542 the conditions that lead to the situation.
1544 CONFIG_NET_RETRY_COUNT
1546 This variable defines the number of retries for
1547 network operations like ARP, RARP, TFTP, or BOOTP
1548 before giving up the operation. If not defined, a
1549 default value of 5 is used.
1551 - Command Interpreter:
1552 CONFIG_AUTO_COMPLETE
1554 Enable auto completion of commands using TAB.
1556 Note that this feature has NOT been implemented yet
1557 for the "hush" shell.
1562 Define this variable to enable the "hush" shell (from
1563 Busybox) as command line interpreter, thus enabling
1564 powerful command line syntax like
1565 if...then...else...fi conditionals or `&&' and '||'
1566 constructs ("shell scripts").
1568 If undefined, you get the old, much simpler behaviour
1569 with a somewhat smaller memory footprint.
1574 This defines the secondary prompt string, which is
1575 printed when the command interpreter needs more input
1576 to complete a command. Usually "> ".
1580 In the current implementation, the local variables
1581 space and global environment variables space are
1582 separated. Local variables are those you define by
1583 simply typing `name=value'. To access a local
1584 variable later on, you have write `$name' or
1585 `${name}'; to execute the contents of a variable
1586 directly type `$name' at the command prompt.
1588 Global environment variables are those you use
1589 setenv/printenv to work with. To run a command stored
1590 in such a variable, you need to use the run command,
1591 and you must not use the '$' sign to access them.
1593 To store commands and special characters in a
1594 variable, please use double quotation marks
1595 surrounding the whole text of the variable, instead
1596 of the backslashes before semicolons and special
1599 - Commandline Editing and History:
1600 CONFIG_CMDLINE_EDITING
1602 Enable editiong and History functions for interactive
1603 commandline input operations
1605 - Default Environment:
1606 CONFIG_EXTRA_ENV_SETTINGS
1608 Define this to contain any number of null terminated
1609 strings (variable = value pairs) that will be part of
1610 the default environment compiled into the boot image.
1612 For example, place something like this in your
1613 board's config file:
1615 #define CONFIG_EXTRA_ENV_SETTINGS \
1619 Warning: This method is based on knowledge about the
1620 internal format how the environment is stored by the
1621 U-Boot code. This is NOT an official, exported
1622 interface! Although it is unlikely that this format
1623 will change soon, there is no guarantee either.
1624 You better know what you are doing here.
1626 Note: overly (ab)use of the default environment is
1627 discouraged. Make sure to check other ways to preset
1628 the environment like the autoscript function or the
1631 - DataFlash Support:
1632 CONFIG_HAS_DATAFLASH
1634 Defining this option enables DataFlash features and
1635 allows to read/write in Dataflash via the standard
1638 - SystemACE Support:
1641 Adding this option adds support for Xilinx SystemACE
1642 chips attached via some sort of local bus. The address
1643 of the chip must alsh be defined in the
1644 CFG_SYSTEMACE_BASE macro. For example:
1646 #define CONFIG_SYSTEMACE
1647 #define CFG_SYSTEMACE_BASE 0xf0000000
1649 When SystemACE support is added, the "ace" device type
1650 becomes available to the fat commands, i.e. fatls.
1652 - TFTP Fixed UDP Port:
1655 If this is defined, the environment variable tftpsrcp
1656 is used to supply the TFTP UDP source port value.
1657 If tftpsrcp isn't defined, the normal pseudo-random port
1658 number generator is used.
1660 Also, the environment variable tftpdstp is used to supply
1661 the TFTP UDP destination port value. If tftpdstp isn't
1662 defined, the normal port 69 is used.
1664 The purpose for tftpsrcp is to allow a TFTP server to
1665 blindly start the TFTP transfer using the pre-configured
1666 target IP address and UDP port. This has the effect of
1667 "punching through" the (Windows XP) firewall, allowing
1668 the remainder of the TFTP transfer to proceed normally.
1669 A better solution is to properly configure the firewall,
1670 but sometimes that is not allowed.
1672 - Show boot progress:
1673 CONFIG_SHOW_BOOT_PROGRESS
1675 Defining this option allows to add some board-
1676 specific code (calling a user-provided function
1677 "show_boot_progress(int)") that enables you to show
1678 the system's boot progress on some display (for
1679 example, some LED's) on your board. At the moment,
1680 the following checkpoints are implemented:
1682 Legacy uImage format:
1685 1 common/cmd_bootm.c before attempting to boot an image
1686 -1 common/cmd_bootm.c Image header has bad magic number
1687 2 common/cmd_bootm.c Image header has correct magic number
1688 -2 common/cmd_bootm.c Image header has bad checksum
1689 3 common/cmd_bootm.c Image header has correct checksum
1690 -3 common/cmd_bootm.c Image data has bad checksum
1691 4 common/cmd_bootm.c Image data has correct checksum
1692 -4 common/cmd_bootm.c Image is for unsupported architecture
1693 5 common/cmd_bootm.c Architecture check OK
1694 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi)
1695 6 common/cmd_bootm.c Image Type check OK
1696 -6 common/cmd_bootm.c gunzip uncompression error
1697 -7 common/cmd_bootm.c Unimplemented compression type
1698 7 common/cmd_bootm.c Uncompression OK
1699 8 common/cmd_bootm.c No uncompress/copy overwrite error
1700 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX)
1702 9 common/image.c Start initial ramdisk verification
1703 -10 common/image.c Ramdisk header has bad magic number
1704 -11 common/image.c Ramdisk header has bad checksum
1705 10 common/image.c Ramdisk header is OK
1706 -12 common/image.c Ramdisk data has bad checksum
1707 11 common/image.c Ramdisk data has correct checksum
1708 12 common/image.c Ramdisk verification complete, start loading
1709 -13 common/image.c Wrong Image Type (not PPC Linux Ramdisk)
1710 13 common/image.c Start multifile image verification
1711 14 common/image.c No initial ramdisk, no multifile, continue.
1713 15 lib_<arch>/bootm.c All preparation done, transferring control to OS
1715 -30 lib_ppc/board.c Fatal error, hang the system
1716 -31 post/post.c POST test failed, detected by post_output_backlog()
1717 -32 post/post.c POST test failed, detected by post_run_single()
1719 34 common/cmd_doc.c before loading a Image from a DOC device
1720 -35 common/cmd_doc.c Bad usage of "doc" command
1721 35 common/cmd_doc.c correct usage of "doc" command
1722 -36 common/cmd_doc.c No boot device
1723 36 common/cmd_doc.c correct boot device
1724 -37 common/cmd_doc.c Unknown Chip ID on boot device
1725 37 common/cmd_doc.c correct chip ID found, device available
1726 -38 common/cmd_doc.c Read Error on boot device
1727 38 common/cmd_doc.c reading Image header from DOC device OK
1728 -39 common/cmd_doc.c Image header has bad magic number
1729 39 common/cmd_doc.c Image header has correct magic number
1730 -40 common/cmd_doc.c Error reading Image from DOC device
1731 40 common/cmd_doc.c Image header has correct magic number
1732 41 common/cmd_ide.c before loading a Image from a IDE device
1733 -42 common/cmd_ide.c Bad usage of "ide" command
1734 42 common/cmd_ide.c correct usage of "ide" command
1735 -43 common/cmd_ide.c No boot device
1736 43 common/cmd_ide.c boot device found
1737 -44 common/cmd_ide.c Device not available
1738 44 common/cmd_ide.c Device available
1739 -45 common/cmd_ide.c wrong partition selected
1740 45 common/cmd_ide.c partition selected
1741 -46 common/cmd_ide.c Unknown partition table
1742 46 common/cmd_ide.c valid partition table found
1743 -47 common/cmd_ide.c Invalid partition type
1744 47 common/cmd_ide.c correct partition type
1745 -48 common/cmd_ide.c Error reading Image Header on boot device
1746 48 common/cmd_ide.c reading Image Header from IDE device OK
1747 -49 common/cmd_ide.c Image header has bad magic number
1748 49 common/cmd_ide.c Image header has correct magic number
1749 -50 common/cmd_ide.c Image header has bad checksum
1750 50 common/cmd_ide.c Image header has correct checksum
1751 -51 common/cmd_ide.c Error reading Image from IDE device
1752 51 common/cmd_ide.c reading Image from IDE device OK
1753 52 common/cmd_nand.c before loading a Image from a NAND device
1754 -53 common/cmd_nand.c Bad usage of "nand" command
1755 53 common/cmd_nand.c correct usage of "nand" command
1756 -54 common/cmd_nand.c No boot device
1757 54 common/cmd_nand.c boot device found
1758 -55 common/cmd_nand.c Unknown Chip ID on boot device
1759 55 common/cmd_nand.c correct chip ID found, device available
1760 -56 common/cmd_nand.c Error reading Image Header on boot device
1761 56 common/cmd_nand.c reading Image Header from NAND device OK
1762 -57 common/cmd_nand.c Image header has bad magic number
1763 57 common/cmd_nand.c Image header has correct magic number
1764 -58 common/cmd_nand.c Error reading Image from NAND device
1765 58 common/cmd_nand.c reading Image from NAND device OK
1767 -60 common/env_common.c Environment has a bad CRC, using default
1769 64 net/eth.c starting with Ethernetconfiguration.
1770 -64 net/eth.c no Ethernet found.
1771 65 net/eth.c Ethernet found.
1773 -80 common/cmd_net.c usage wrong
1774 80 common/cmd_net.c before calling NetLoop()
1775 -81 common/cmd_net.c some error in NetLoop() occured
1776 81 common/cmd_net.c NetLoop() back without error
1777 -82 common/cmd_net.c size == 0 (File with size 0 loaded)
1778 82 common/cmd_net.c trying automatic boot
1779 83 common/cmd_net.c running autoscript
1780 -83 common/cmd_net.c some error in automatic boot or autoscript
1781 84 common/cmd_net.c end without errors
1786 100 common/cmd_bootm.c Kernel FIT Image has correct format
1787 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format
1788 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration
1789 -101 common/cmd_bootm.c Can't get configuration for kernel subimage
1790 102 common/cmd_bootm.c Kernel unit name specified
1791 -103 common/cmd_bootm.c Can't get kernel subimage node offset
1792 103 common/cmd_bootm.c Found configuration node
1793 104 common/cmd_bootm.c Got kernel subimage node offset
1794 -104 common/cmd_bootm.c Kernel subimage hash verification failed
1795 105 common/cmd_bootm.c Kernel subimage hash verification OK
1796 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture
1797 106 common/cmd_bootm.c Architecture check OK
1798 -106 common/cmd_bootm.c Kernel subimage has wrong typea
1799 107 common/cmd_bootm.c Kernel subimge type OK
1800 -107 common/cmd_bootm.c Can't get kernel subimage data/size
1801 108 common/cmd_bootm.c Got kernel subimage data/size
1802 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT)
1803 -109 common/cmd_bootm.c Can't get kernel subimage type
1804 -110 common/cmd_bootm.c Can't get kernel subimage comp
1805 -111 common/cmd_bootm.c Can't get kernel subimage os
1806 -112 common/cmd_bootm.c Can't get kernel subimage load address
1807 -113 common/cmd_bootm.c Image uncompress/copy overwrite error
1809 120 common/image.c Start initial ramdisk verification
1810 -120 common/image.c Ramdisk FIT image has incorrect format
1811 121 common/image.c Ramdisk FIT image has correct format
1812 122 common/image.c No Ramdisk subimage unit name, using configuration
1813 -122 common/image.c Can't get configuration for ramdisk subimage
1814 123 common/image.c Ramdisk unit name specified
1815 -124 common/image.c Can't get ramdisk subimage node offset
1816 125 common/image.c Got ramdisk subimage node offset
1817 -125 common/image.c Ramdisk subimage hash verification failed
1818 126 common/image.c Ramdisk subimage hash verification OK
1819 -126 common/image.c Ramdisk subimage for unsupported architecture
1820 127 common/image.c Architecture check OK
1821 -127 common/image.c Can't get ramdisk subimage data/size
1822 128 common/image.c Got ramdisk subimage data/size
1823 129 common/image.c Can't get ramdisk load address
1824 -129 common/image.c Got ramdisk load address
1826 -130 common/cmd_doc.c Icorrect FIT image format
1827 131 common/cmd_doc.c FIT image format OK
1829 -140 common/cmd_ide.c Icorrect FIT image format
1830 141 common/cmd_ide.c FIT image format OK
1832 -150 common/cmd_nand.c Icorrect FIT image format
1833 151 common/cmd_nand.c FIT image format OK
1839 [so far only for SMDK2400 and TRAB boards]
1841 - Modem support endable:
1842 CONFIG_MODEM_SUPPORT
1844 - RTS/CTS Flow control enable:
1847 - Modem debug support:
1848 CONFIG_MODEM_SUPPORT_DEBUG
1850 Enables debugging stuff (char screen[1024], dbg())
1851 for modem support. Useful only with BDI2000.
1853 - Interrupt support (PPC):
1855 There are common interrupt_init() and timer_interrupt()
1856 for all PPC archs. interrupt_init() calls interrupt_init_cpu()
1857 for cpu specific initialization. interrupt_init_cpu()
1858 should set decrementer_count to appropriate value. If
1859 cpu resets decrementer automatically after interrupt
1860 (ppc4xx) it should set decrementer_count to zero.
1861 timer_interrupt() calls timer_interrupt_cpu() for cpu
1862 specific handling. If board has watchdog / status_led
1863 / other_activity_monitor it works automatically from
1864 general timer_interrupt().
1868 In the target system modem support is enabled when a
1869 specific key (key combination) is pressed during
1870 power-on. Otherwise U-Boot will boot normally
1871 (autoboot). The key_pressed() fuction is called from
1872 board_init(). Currently key_pressed() is a dummy
1873 function, returning 1 and thus enabling modem
1876 If there are no modem init strings in the
1877 environment, U-Boot proceed to autoboot; the
1878 previous output (banner, info printfs) will be
1881 See also: doc/README.Modem
1884 Configuration Settings:
1885 -----------------------
1887 - CFG_LONGHELP: Defined when you want long help messages included;
1888 undefine this when you're short of memory.
1890 - CFG_PROMPT: This is what U-Boot prints on the console to
1891 prompt for user input.
1893 - CFG_CBSIZE: Buffer size for input from the Console
1895 - CFG_PBSIZE: Buffer size for Console output
1897 - CFG_MAXARGS: max. Number of arguments accepted for monitor commands
1899 - CFG_BARGSIZE: Buffer size for Boot Arguments which are passed to
1900 the application (usually a Linux kernel) when it is
1903 - CFG_BAUDRATE_TABLE:
1904 List of legal baudrate settings for this board.
1906 - CFG_CONSOLE_INFO_QUIET
1907 Suppress display of console information at boot.
1909 - CFG_CONSOLE_IS_IN_ENV
1910 If the board specific function
1911 extern int overwrite_console (void);
1912 returns 1, the stdin, stderr and stdout are switched to the
1913 serial port, else the settings in the environment are used.
1915 - CFG_CONSOLE_OVERWRITE_ROUTINE
1916 Enable the call to overwrite_console().
1918 - CFG_CONSOLE_ENV_OVERWRITE
1919 Enable overwrite of previous console environment settings.
1921 - CFG_MEMTEST_START, CFG_MEMTEST_END:
1922 Begin and End addresses of the area used by the
1926 Enable an alternate, more extensive memory test.
1928 - CFG_MEMTEST_SCRATCH:
1929 Scratch address used by the alternate memory test
1930 You only need to set this if address zero isn't writeable
1932 - CFG_TFTP_LOADADDR:
1933 Default load address for network file downloads
1935 - CFG_LOADS_BAUD_CHANGE:
1936 Enable temporary baudrate change while serial download
1939 Physical start address of SDRAM. _Must_ be 0 here.
1942 Physical start address of Motherboard I/O (if using a
1946 Physical start address of Flash memory.
1949 Physical start address of boot monitor code (set by
1950 make config files to be same as the text base address
1951 (TEXT_BASE) used when linking) - same as
1952 CFG_FLASH_BASE when booting from flash.
1955 Size of memory reserved for monitor code, used to
1956 determine _at_compile_time_ (!) if the environment is
1957 embedded within the U-Boot image, or in a separate
1961 Size of DRAM reserved for malloc() use.
1964 Normally compressed uImages are limited to an
1965 uncompressed size of 8 MBytes. If this is not enough,
1966 you can define CFG_BOOTM_LEN in your board config file
1967 to adjust this setting to your needs.
1970 Maximum size of memory mapped by the startup code of
1971 the Linux kernel; all data that must be processed by
1972 the Linux kernel (bd_info, boot arguments, eventually
1973 initrd image) must be put below this limit.
1975 - CFG_MAX_FLASH_BANKS:
1976 Max number of Flash memory banks
1978 - CFG_MAX_FLASH_SECT:
1979 Max number of sectors on a Flash chip
1981 - CFG_FLASH_ERASE_TOUT:
1982 Timeout for Flash erase operations (in ms)
1984 - CFG_FLASH_WRITE_TOUT:
1985 Timeout for Flash write operations (in ms)
1987 - CFG_FLASH_LOCK_TOUT
1988 Timeout for Flash set sector lock bit operation (in ms)
1990 - CFG_FLASH_UNLOCK_TOUT
1991 Timeout for Flash clear lock bits operation (in ms)
1993 - CFG_FLASH_PROTECTION
1994 If defined, hardware flash sectors protection is used
1995 instead of U-Boot software protection.
1997 - CFG_DIRECT_FLASH_TFTP:
1999 Enable TFTP transfers directly to flash memory;
2000 without this option such a download has to be
2001 performed in two steps: (1) download to RAM, and (2)
2002 copy from RAM to flash.
2004 The two-step approach is usually more reliable, since
2005 you can check if the download worked before you erase
2006 the flash, but in some situations (when sytem RAM is
2007 too limited to allow for a tempory copy of the
2008 downloaded image) this option may be very useful.
2011 Define if the flash driver uses extra elements in the
2012 common flash structure for storing flash geometry.
2014 - CFG_FLASH_CFI_DRIVER
2015 This option also enables the building of the cfi_flash driver
2016 in the drivers directory
2018 - CFG_FLASH_QUIET_TEST
2019 If this option is defined, the common CFI flash doesn't
2020 print it's warning upon not recognized FLASH banks. This
2021 is useful, if some of the configured banks are only
2022 optionally available.
2024 - CONFIG_FLASH_SHOW_PROGRESS
2025 If defined (must be an integer), print out countdown
2026 digits and dots. Recommended value: 45 (9..1) for 80
2027 column displays, 15 (3..1) for 40 column displays.
2029 - CFG_RX_ETH_BUFFER:
2030 Defines the number of ethernet receive buffers. On some
2031 ethernet controllers it is recommended to set this value
2032 to 8 or even higher (EEPRO100 or 405 EMAC), since all
2033 buffers can be full shortly after enabling the interface
2034 on high ethernet traffic.
2035 Defaults to 4 if not defined.
2037 The following definitions that deal with the placement and management
2038 of environment data (variable area); in general, we support the
2039 following configurations:
2041 - CFG_ENV_IS_IN_FLASH:
2043 Define this if the environment is in flash memory.
2045 a) The environment occupies one whole flash sector, which is
2046 "embedded" in the text segment with the U-Boot code. This
2047 happens usually with "bottom boot sector" or "top boot
2048 sector" type flash chips, which have several smaller
2049 sectors at the start or the end. For instance, such a
2050 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In
2051 such a case you would place the environment in one of the
2052 4 kB sectors - with U-Boot code before and after it. With
2053 "top boot sector" type flash chips, you would put the
2054 environment in one of the last sectors, leaving a gap
2055 between U-Boot and the environment.
2059 Offset of environment data (variable area) to the
2060 beginning of flash memory; for instance, with bottom boot
2061 type flash chips the second sector can be used: the offset
2062 for this sector is given here.
2064 CFG_ENV_OFFSET is used relative to CFG_FLASH_BASE.
2068 This is just another way to specify the start address of
2069 the flash sector containing the environment (instead of
2072 - CFG_ENV_SECT_SIZE:
2074 Size of the sector containing the environment.
2077 b) Sometimes flash chips have few, equal sized, BIG sectors.
2078 In such a case you don't want to spend a whole sector for
2083 If you use this in combination with CFG_ENV_IS_IN_FLASH
2084 and CFG_ENV_SECT_SIZE, you can specify to use only a part
2085 of this flash sector for the environment. This saves
2086 memory for the RAM copy of the environment.
2088 It may also save flash memory if you decide to use this
2089 when your environment is "embedded" within U-Boot code,
2090 since then the remainder of the flash sector could be used
2091 for U-Boot code. It should be pointed out that this is
2092 STRONGLY DISCOURAGED from a robustness point of view:
2093 updating the environment in flash makes it always
2094 necessary to erase the WHOLE sector. If something goes
2095 wrong before the contents has been restored from a copy in
2096 RAM, your target system will be dead.
2098 - CFG_ENV_ADDR_REDUND
2101 These settings describe a second storage area used to hold
2102 a redundand copy of the environment data, so that there is
2103 a valid backup copy in case there is a power failure during
2104 a "saveenv" operation.
2106 BE CAREFUL! Any changes to the flash layout, and some changes to the
2107 source code will make it necessary to adapt <board>/u-boot.lds*
2111 - CFG_ENV_IS_IN_NVRAM:
2113 Define this if you have some non-volatile memory device
2114 (NVRAM, battery buffered SRAM) which you want to use for the
2120 These two #defines are used to determin the memory area you
2121 want to use for environment. It is assumed that this memory
2122 can just be read and written to, without any special
2125 BE CAREFUL! The first access to the environment happens quite early
2126 in U-Boot initalization (when we try to get the setting of for the
2127 console baudrate). You *MUST* have mappend your NVRAM area then, or
2130 Please note that even with NVRAM we still use a copy of the
2131 environment in RAM: we could work on NVRAM directly, but we want to
2132 keep settings there always unmodified except somebody uses "saveenv"
2133 to save the current settings.
2136 - CFG_ENV_IS_IN_EEPROM:
2138 Use this if you have an EEPROM or similar serial access
2139 device and a driver for it.
2144 These two #defines specify the offset and size of the
2145 environment area within the total memory of your EEPROM.
2147 - CFG_I2C_EEPROM_ADDR:
2148 If defined, specified the chip address of the EEPROM device.
2149 The default address is zero.
2151 - CFG_EEPROM_PAGE_WRITE_BITS:
2152 If defined, the number of bits used to address bytes in a
2153 single page in the EEPROM device. A 64 byte page, for example
2154 would require six bits.
2156 - CFG_EEPROM_PAGE_WRITE_DELAY_MS:
2157 If defined, the number of milliseconds to delay between
2158 page writes. The default is zero milliseconds.
2160 - CFG_I2C_EEPROM_ADDR_LEN:
2161 The length in bytes of the EEPROM memory array address. Note
2162 that this is NOT the chip address length!
2164 - CFG_I2C_EEPROM_ADDR_OVERFLOW:
2165 EEPROM chips that implement "address overflow" are ones
2166 like Catalyst 24WC04/08/16 which has 9/10/11 bits of
2167 address and the extra bits end up in the "chip address" bit
2168 slots. This makes a 24WC08 (1Kbyte) chip look like four 256
2171 Note that we consider the length of the address field to
2172 still be one byte because the extra address bits are hidden
2173 in the chip address.
2176 The size in bytes of the EEPROM device.
2179 - CFG_ENV_IS_IN_DATAFLASH:
2181 Define this if you have a DataFlash memory device which you
2182 want to use for the environment.
2188 These three #defines specify the offset and size of the
2189 environment area within the total memory of your DataFlash placed
2190 at the specified address.
2192 - CFG_ENV_IS_IN_NAND:
2194 Define this if you have a NAND device which you want to use
2195 for the environment.
2200 These two #defines specify the offset and size of the environment
2201 area within the first NAND device.
2203 - CFG_ENV_OFFSET_REDUND
2205 This setting describes a second storage area of CFG_ENV_SIZE
2206 size used to hold a redundant copy of the environment data,
2207 so that there is a valid backup copy in case there is a
2208 power failure during a "saveenv" operation.
2210 Note: CFG_ENV_OFFSET and CFG_ENV_OFFSET_REDUND must be aligned
2211 to a block boundary, and CFG_ENV_SIZE must be a multiple of
2212 the NAND devices block size.
2214 - CFG_SPI_INIT_OFFSET
2216 Defines offset to the initial SPI buffer area in DPRAM. The
2217 area is used at an early stage (ROM part) if the environment
2218 is configured to reside in the SPI EEPROM: We need a 520 byte
2219 scratch DPRAM area. It is used between the two initialization
2220 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems
2221 to be a good choice since it makes it far enough from the
2222 start of the data area as well as from the stack pointer.
2224 Please note that the environment is read-only until the monitor
2225 has been relocated to RAM and a RAM copy of the environment has been
2226 created; also, when using EEPROM you will have to use getenv_r()
2227 until then to read environment variables.
2229 The environment is protected by a CRC32 checksum. Before the monitor
2230 is relocated into RAM, as a result of a bad CRC you will be working
2231 with the compiled-in default environment - *silently*!!! [This is
2232 necessary, because the first environment variable we need is the
2233 "baudrate" setting for the console - if we have a bad CRC, we don't
2234 have any device yet where we could complain.]
2236 Note: once the monitor has been relocated, then it will complain if
2237 the default environment is used; a new CRC is computed as soon as you
2238 use the "saveenv" command to store a valid environment.
2240 - CFG_FAULT_ECHO_LINK_DOWN:
2241 Echo the inverted Ethernet link state to the fault LED.
2243 Note: If this option is active, then CFG_FAULT_MII_ADDR
2244 also needs to be defined.
2246 - CFG_FAULT_MII_ADDR:
2247 MII address of the PHY to check for the Ethernet link state.
2249 - CFG_64BIT_VSPRINTF:
2250 Makes vsprintf (and all *printf functions) support printing
2251 of 64bit values by using the L quantifier
2253 - CFG_64BIT_STRTOUL:
2254 Adds simple_strtoull that returns a 64bit value
2256 Low Level (hardware related) configuration options:
2257 ---------------------------------------------------
2259 - CFG_CACHELINE_SIZE:
2260 Cache Line Size of the CPU.
2263 Default address of the IMMR after system reset.
2265 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU,
2266 and RPXsuper) to be able to adjust the position of
2267 the IMMR register after a reset.
2269 - Floppy Disk Support:
2270 CFG_FDC_DRIVE_NUMBER
2272 the default drive number (default value 0)
2276 defines the spacing between fdc chipset registers
2281 defines the offset of register from address. It
2282 depends on which part of the data bus is connected to
2283 the fdc chipset. (default value 0)
2285 If CFG_ISA_IO_STRIDE CFG_ISA_IO_OFFSET and
2286 CFG_FDC_DRIVE_NUMBER are undefined, they take their
2289 if CFG_FDC_HW_INIT is defined, then the function
2290 fdc_hw_init() is called at the beginning of the FDC
2291 setup. fdc_hw_init() must be provided by the board
2292 source code. It is used to make hardware dependant
2295 - CFG_IMMR: Physical address of the Internal Memory.
2296 DO NOT CHANGE unless you know exactly what you're
2297 doing! (11-4) [MPC8xx/82xx systems only]
2299 - CFG_INIT_RAM_ADDR:
2301 Start address of memory area that can be used for
2302 initial data and stack; please note that this must be
2303 writable memory that is working WITHOUT special
2304 initialization, i. e. you CANNOT use normal RAM which
2305 will become available only after programming the
2306 memory controller and running certain initialization
2309 U-Boot uses the following memory types:
2310 - MPC8xx and MPC8260: IMMR (internal memory of the CPU)
2311 - MPC824X: data cache
2312 - PPC4xx: data cache
2314 - CFG_GBL_DATA_OFFSET:
2316 Offset of the initial data structure in the memory
2317 area defined by CFG_INIT_RAM_ADDR. Usually
2318 CFG_GBL_DATA_OFFSET is chosen such that the initial
2319 data is located at the end of the available space
2320 (sometimes written as (CFG_INIT_RAM_END -
2321 CFG_INIT_DATA_SIZE), and the initial stack is just
2322 below that area (growing from (CFG_INIT_RAM_ADDR +
2323 CFG_GBL_DATA_OFFSET) downward.
2326 On the MPC824X (or other systems that use the data
2327 cache for initial memory) the address chosen for
2328 CFG_INIT_RAM_ADDR is basically arbitrary - it must
2329 point to an otherwise UNUSED address space between
2330 the top of RAM and the start of the PCI space.
2332 - CFG_SIUMCR: SIU Module Configuration (11-6)
2334 - CFG_SYPCR: System Protection Control (11-9)
2336 - CFG_TBSCR: Time Base Status and Control (11-26)
2338 - CFG_PISCR: Periodic Interrupt Status and Control (11-31)
2340 - CFG_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30)
2342 - CFG_SCCR: System Clock and reset Control Register (15-27)
2344 - CFG_OR_TIMING_SDRAM:
2348 periodic timer for refresh
2350 - CFG_DER: Debug Event Register (37-47)
2352 - FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CFG_REMAP_OR_AM,
2353 CFG_PRELIM_OR_AM, CFG_OR_TIMING_FLASH, CFG_OR0_REMAP,
2354 CFG_OR0_PRELIM, CFG_BR0_PRELIM, CFG_OR1_REMAP, CFG_OR1_PRELIM,
2356 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
2358 - SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
2359 CFG_OR_TIMING_SDRAM, CFG_OR2_PRELIM, CFG_BR2_PRELIM,
2360 CFG_OR3_PRELIM, CFG_BR3_PRELIM:
2361 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
2363 - CFG_MAMR_PTA, CFG_MPTPR_2BK_4K, CFG_MPTPR_1BK_4K, CFG_MPTPR_2BK_8K,
2364 CFG_MPTPR_1BK_8K, CFG_MAMR_8COL, CFG_MAMR_9COL:
2365 Machine Mode Register and Memory Periodic Timer
2366 Prescaler definitions (SDRAM timing)
2368 - CFG_I2C_UCODE_PATCH, CFG_I2C_DPMEM_OFFSET [0x1FC0]:
2369 enable I2C microcode relocation patch (MPC8xx);
2370 define relocation offset in DPRAM [DSP2]
2372 - CFG_SMC_UCODE_PATCH, CFG_SMC_DPMEM_OFFSET [0x1FC0]:
2373 enable SMC microcode relocation patch (MPC8xx);
2374 define relocation offset in DPRAM [SMC1]
2376 - CFG_SPI_UCODE_PATCH, CFG_SPI_DPMEM_OFFSET [0x1FC0]:
2377 enable SPI microcode relocation patch (MPC8xx);
2378 define relocation offset in DPRAM [SCC4]
2381 Use OSCM clock mode on MBX8xx board. Be careful,
2382 wrong setting might damage your board. Read
2383 doc/README.MBX before setting this variable!
2385 - CFG_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only)
2386 Offset of the bootmode word in DPRAM used by post
2387 (Power On Self Tests). This definition overrides
2388 #define'd default value in commproc.h resp.
2391 - CFG_PCI_SLV_MEM_LOCAL, CFG_PCI_SLV_MEM_BUS, CFG_PICMR0_MASK_ATTRIB,
2392 CFG_PCI_MSTR0_LOCAL, CFG_PCIMSK0_MASK, CFG_PCI_MSTR1_LOCAL,
2393 CFG_PCIMSK1_MASK, CFG_PCI_MSTR_MEM_LOCAL, CFG_PCI_MSTR_MEM_BUS,
2394 CFG_CPU_PCI_MEM_START, CFG_PCI_MSTR_MEM_SIZE, CFG_POCMR0_MASK_ATTRIB,
2395 CFG_PCI_MSTR_MEMIO_LOCAL, CFG_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START,
2396 CFG_PCI_MSTR_MEMIO_SIZE, CFG_POCMR1_MASK_ATTRIB, CFG_PCI_MSTR_IO_LOCAL,
2397 CFG_PCI_MSTR_IO_BUS, CFG_CPU_PCI_IO_START, CFG_PCI_MSTR_IO_SIZE,
2398 CFG_POCMR2_MASK_ATTRIB: (MPC826x only)
2399 Overrides the default PCI memory map in cpu/mpc8260/pci.c if set.
2402 Get DDR timing information from an I2C EEPROM. Common
2403 with pluggable memory modules such as SODIMMs
2406 I2C address of the SPD EEPROM
2409 If SPD EEPROM is on an I2C bus other than the first
2410 one, specify here. Note that the value must resolve
2411 to something your driver can deal with.
2413 - CFG_83XX_DDR_USES_CS0
2414 Only for 83xx systems. If specified, then DDR should
2415 be configured using CS0 and CS1 instead of CS2 and CS3.
2417 - CFG_83XX_DDR_USES_CS0
2418 Only for 83xx systems. If specified, then DDR should
2419 be configured using CS0 and CS1 instead of CS2 and CS3.
2421 - CONFIG_ETHER_ON_FEC[12]
2422 Define to enable FEC[12] on a 8xx series processor.
2424 - CONFIG_FEC[12]_PHY
2425 Define to the hardcoded PHY address which corresponds
2426 to the given FEC; i. e.
2427 #define CONFIG_FEC1_PHY 4
2428 means that the PHY with address 4 is connected to FEC1
2430 When set to -1, means to probe for first available.
2432 - CONFIG_FEC[12]_PHY_NORXERR
2433 The PHY does not have a RXERR line (RMII only).
2434 (so program the FEC to ignore it).
2437 Enable RMII mode for all FECs.
2438 Note that this is a global option, we can't
2439 have one FEC in standard MII mode and another in RMII mode.
2441 - CONFIG_CRC32_VERIFY
2442 Add a verify option to the crc32 command.
2445 => crc32 -v <address> <count> <crc32>
2447 Where address/count indicate a memory area
2448 and crc32 is the correct crc32 which the
2452 Add the "loopw" memory command. This only takes effect if
2453 the memory commands are activated globally (CONFIG_CMD_MEM).
2456 Add the "mdc" and "mwc" memory commands. These are cyclic
2461 This command will print 4 bytes (10,11,12,13) each 500 ms.
2463 => mwc.l 100 12345678 10
2464 This command will write 12345678 to address 100 all 10 ms.
2466 This only takes effect if the memory commands are activated
2467 globally (CONFIG_CMD_MEM).
2469 - CONFIG_SKIP_LOWLEVEL_INIT
2470 - CONFIG_SKIP_RELOCATE_UBOOT
2472 [ARM only] If these variables are defined, then
2473 certain low level initializations (like setting up
2474 the memory controller) are omitted and/or U-Boot does
2475 not relocate itself into RAM.
2476 Normally these variables MUST NOT be defined. The
2477 only exception is when U-Boot is loaded (to RAM) by
2478 some other boot loader or by a debugger which
2479 performs these intializations itself.
2482 Building the Software:
2483 ======================
2485 Building U-Boot has been tested in several native build environments
2486 and in many different cross environments. Of course we cannot support
2487 all possibly existing versions of cross development tools in all
2488 (potentially obsolete) versions. In case of tool chain problems we
2489 recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK)
2490 which is extensively used to build and test U-Boot.
2492 If you are not using a native environment, it is assumed that you
2493 have GNU cross compiling tools available in your path. In this case,
2494 you must set the environment variable CROSS_COMPILE in your shell.
2495 Note that no changes to the Makefile or any other source files are
2496 necessary. For example using the ELDK on a 4xx CPU, please enter:
2498 $ CROSS_COMPILE=ppc_4xx-
2499 $ export CROSS_COMPILE
2501 U-Boot is intended to be simple to build. After installing the
2502 sources you must configure U-Boot for one specific board type. This
2507 where "NAME_config" is the name of one of the existing configu-
2508 rations; see the main Makefile for supported names.
2510 Note: for some board special configuration names may exist; check if
2511 additional information is available from the board vendor; for
2512 instance, the TQM823L systems are available without (standard)
2513 or with LCD support. You can select such additional "features"
2514 when chosing the configuration, i. e.
2517 - will configure for a plain TQM823L, i. e. no LCD support
2519 make TQM823L_LCD_config
2520 - will configure for a TQM823L with U-Boot console on LCD
2525 Finally, type "make all", and you should get some working U-Boot
2526 images ready for download to / installation on your system:
2528 - "u-boot.bin" is a raw binary image
2529 - "u-boot" is an image in ELF binary format
2530 - "u-boot.srec" is in Motorola S-Record format
2532 By default the build is performed locally and the objects are saved
2533 in the source directory. One of the two methods can be used to change
2534 this behavior and build U-Boot to some external directory:
2536 1. Add O= to the make command line invocations:
2538 make O=/tmp/build distclean
2539 make O=/tmp/build NAME_config
2540 make O=/tmp/build all
2542 2. Set environment variable BUILD_DIR to point to the desired location:
2544 export BUILD_DIR=/tmp/build
2549 Note that the command line "O=" setting overrides the BUILD_DIR environment
2553 Please be aware that the Makefiles assume you are using GNU make, so
2554 for instance on NetBSD you might need to use "gmake" instead of
2558 If the system board that you have is not listed, then you will need
2559 to port U-Boot to your hardware platform. To do this, follow these
2562 1. Add a new configuration option for your board to the toplevel
2563 "Makefile" and to the "MAKEALL" script, using the existing
2564 entries as examples. Note that here and at many other places
2565 boards and other names are listed in alphabetical sort order. Please
2567 2. Create a new directory to hold your board specific code. Add any
2568 files you need. In your board directory, you will need at least
2569 the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds".
2570 3. Create a new configuration file "include/configs/<board>.h" for
2572 3. If you're porting U-Boot to a new CPU, then also create a new
2573 directory to hold your CPU specific code. Add any files you need.
2574 4. Run "make <board>_config" with your new name.
2575 5. Type "make", and you should get a working "u-boot.srec" file
2576 to be installed on your target system.
2577 6. Debug and solve any problems that might arise.
2578 [Of course, this last step is much harder than it sounds.]
2581 Testing of U-Boot Modifications, Ports to New Hardware, etc.:
2582 ==============================================================
2584 If you have modified U-Boot sources (for instance added a new board
2585 or support for new devices, a new CPU, etc.) you are expected to
2586 provide feedback to the other developers. The feedback normally takes
2587 the form of a "patch", i. e. a context diff against a certain (latest
2588 official or latest in the git repository) version of U-Boot sources.
2590 But before you submit such a patch, please verify that your modifi-
2591 cation did not break existing code. At least make sure that *ALL* of
2592 the supported boards compile WITHOUT ANY compiler warnings. To do so,
2593 just run the "MAKEALL" script, which will configure and build U-Boot
2594 for ALL supported system. Be warned, this will take a while. You can
2595 select which (cross) compiler to use by passing a `CROSS_COMPILE'
2596 environment variable to the script, i. e. to use the ELDK cross tools
2599 CROSS_COMPILE=ppc_8xx- MAKEALL
2601 or to build on a native PowerPC system you can type
2603 CROSS_COMPILE=' ' MAKEALL
2605 When using the MAKEALL script, the default behaviour is to build
2606 U-Boot in the source directory. This location can be changed by
2607 setting the BUILD_DIR environment variable. Also, for each target
2608 built, the MAKEALL script saves two log files (<target>.ERR and
2609 <target>.MAKEALL) in the <source dir>/LOG directory. This default
2610 location can be changed by setting the MAKEALL_LOGDIR environment
2611 variable. For example:
2613 export BUILD_DIR=/tmp/build
2614 export MAKEALL_LOGDIR=/tmp/log
2615 CROSS_COMPILE=ppc_8xx- MAKEALL
2617 With the above settings build objects are saved in the /tmp/build,
2618 log files are saved in the /tmp/log and the source tree remains clean
2619 during the whole build process.
2622 See also "U-Boot Porting Guide" below.
2625 Monitor Commands - Overview:
2626 ============================
2628 go - start application at address 'addr'
2629 run - run commands in an environment variable
2630 bootm - boot application image from memory
2631 bootp - boot image via network using BootP/TFTP protocol
2632 tftpboot- boot image via network using TFTP protocol
2633 and env variables "ipaddr" and "serverip"
2634 (and eventually "gatewayip")
2635 rarpboot- boot image via network using RARP/TFTP protocol
2636 diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
2637 loads - load S-Record file over serial line
2638 loadb - load binary file over serial line (kermit mode)
2640 mm - memory modify (auto-incrementing)
2641 nm - memory modify (constant address)
2642 mw - memory write (fill)
2644 cmp - memory compare
2645 crc32 - checksum calculation
2646 imd - i2c memory display
2647 imm - i2c memory modify (auto-incrementing)
2648 inm - i2c memory modify (constant address)
2649 imw - i2c memory write (fill)
2650 icrc32 - i2c checksum calculation
2651 iprobe - probe to discover valid I2C chip addresses
2652 iloop - infinite loop on address range
2653 isdram - print SDRAM configuration information
2654 sspi - SPI utility commands
2655 base - print or set address offset
2656 printenv- print environment variables
2657 setenv - set environment variables
2658 saveenv - save environment variables to persistent storage
2659 protect - enable or disable FLASH write protection
2660 erase - erase FLASH memory
2661 flinfo - print FLASH memory information
2662 bdinfo - print Board Info structure
2663 iminfo - print header information for application image
2664 coninfo - print console devices and informations
2665 ide - IDE sub-system
2666 loop - infinite loop on address range
2667 loopw - infinite write loop on address range
2668 mtest - simple RAM test
2669 icache - enable or disable instruction cache
2670 dcache - enable or disable data cache
2671 reset - Perform RESET of the CPU
2672 echo - echo args to console
2673 version - print monitor version
2674 help - print online help
2675 ? - alias for 'help'
2678 Monitor Commands - Detailed Description:
2679 ========================================
2683 For now: just type "help <command>".
2686 Environment Variables:
2687 ======================
2689 U-Boot supports user configuration using Environment Variables which
2690 can be made persistent by saving to Flash memory.
2692 Environment Variables are set using "setenv", printed using
2693 "printenv", and saved to Flash using "saveenv". Using "setenv"
2694 without a value can be used to delete a variable from the
2695 environment. As long as you don't save the environment you are
2696 working with an in-memory copy. In case the Flash area containing the
2697 environment is erased by accident, a default environment is provided.
2699 Some configuration options can be set using Environment Variables:
2701 baudrate - see CONFIG_BAUDRATE
2703 bootdelay - see CONFIG_BOOTDELAY
2705 bootcmd - see CONFIG_BOOTCOMMAND
2707 bootargs - Boot arguments when booting an RTOS image
2709 bootfile - Name of the image to load with TFTP
2711 autoload - if set to "no" (any string beginning with 'n'),
2712 "bootp" will just load perform a lookup of the
2713 configuration from the BOOTP server, but not try to
2714 load any image using TFTP
2716 autoscript - if set to "yes" commands like "loadb", "loady",
2717 "bootp", "tftpb", "rarpboot" and "nfs" will attempt
2718 to automatically run script images (by internally
2719 calling "autoscript").
2721 autoscript_uname - if script image is in a format (FIT) this
2722 variable is used to get script subimage unit name.
2724 autostart - if set to "yes", an image loaded using the "bootp",
2725 "rarpboot", "tftpboot" or "diskboot" commands will
2726 be automatically started (by internally calling
2729 If set to "no", a standalone image passed to the
2730 "bootm" command will be copied to the load address
2731 (and eventually uncompressed), but NOT be started.
2732 This can be used to load and uncompress arbitrary
2735 i2cfast - (PPC405GP|PPC405EP only)
2736 if set to 'y' configures Linux I2C driver for fast
2737 mode (400kHZ). This environment variable is used in
2738 initialization code. So, for changes to be effective
2739 it must be saved and board must be reset.
2741 initrd_high - restrict positioning of initrd images:
2742 If this variable is not set, initrd images will be
2743 copied to the highest possible address in RAM; this
2744 is usually what you want since it allows for
2745 maximum initrd size. If for some reason you want to
2746 make sure that the initrd image is loaded below the
2747 CFG_BOOTMAPSZ limit, you can set this environment
2748 variable to a value of "no" or "off" or "0".
2749 Alternatively, you can set it to a maximum upper
2750 address to use (U-Boot will still check that it
2751 does not overwrite the U-Boot stack and data).
2753 For instance, when you have a system with 16 MB
2754 RAM, and want to reserve 4 MB from use by Linux,
2755 you can do this by adding "mem=12M" to the value of
2756 the "bootargs" variable. However, now you must make
2757 sure that the initrd image is placed in the first
2758 12 MB as well - this can be done with
2760 setenv initrd_high 00c00000
2762 If you set initrd_high to 0xFFFFFFFF, this is an
2763 indication to U-Boot that all addresses are legal
2764 for the Linux kernel, including addresses in flash
2765 memory. In this case U-Boot will NOT COPY the
2766 ramdisk at all. This may be useful to reduce the
2767 boot time on your system, but requires that this
2768 feature is supported by your Linux kernel.
2770 ipaddr - IP address; needed for tftpboot command
2772 loadaddr - Default load address for commands like "bootp",
2773 "rarpboot", "tftpboot", "loadb" or "diskboot"
2775 loads_echo - see CONFIG_LOADS_ECHO
2777 serverip - TFTP server IP address; needed for tftpboot command
2779 bootretry - see CONFIG_BOOT_RETRY_TIME
2781 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
2783 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
2785 ethprime - When CONFIG_NET_MULTI is enabled controls which
2786 interface is used first.
2788 ethact - When CONFIG_NET_MULTI is enabled controls which
2789 interface is currently active. For example you
2790 can do the following
2792 => setenv ethact FEC ETHERNET
2793 => ping 192.168.0.1 # traffic sent on FEC ETHERNET
2794 => setenv ethact SCC ETHERNET
2795 => ping 10.0.0.1 # traffic sent on SCC ETHERNET
2797 ethrotate - When set to "no" U-Boot does not go through all
2798 available network interfaces.
2799 It just stays at the currently selected interface.
2801 netretry - When set to "no" each network operation will
2802 either succeed or fail without retrying.
2803 When set to "once" the network operation will
2804 fail when all the available network interfaces
2805 are tried once without success.
2806 Useful on scripts which control the retry operation
2809 npe_ucode - see CONFIG_IXP4XX_NPE_EXT_UCOD
2810 if set load address for the npe microcode
2812 tftpsrcport - If this is set, the value is used for TFTP's
2815 tftpdstport - If this is set, the value is used for TFTP's UDP
2816 destination port instead of the Well Know Port 69.
2818 vlan - When set to a value < 4095 the traffic over
2819 ethernet is encapsulated/received over 802.1q
2822 The following environment variables may be used and automatically
2823 updated by the network boot commands ("bootp" and "rarpboot"),
2824 depending the information provided by your boot server:
2826 bootfile - see above
2827 dnsip - IP address of your Domain Name Server
2828 dnsip2 - IP address of your secondary Domain Name Server
2829 gatewayip - IP address of the Gateway (Router) to use
2830 hostname - Target hostname
2832 netmask - Subnet Mask
2833 rootpath - Pathname of the root filesystem on the NFS server
2834 serverip - see above
2837 There are two special Environment Variables:
2839 serial# - contains hardware identification information such
2840 as type string and/or serial number
2841 ethaddr - Ethernet address
2843 These variables can be set only once (usually during manufacturing of
2844 the board). U-Boot refuses to delete or overwrite these variables
2845 once they have been set once.
2848 Further special Environment Variables:
2850 ver - Contains the U-Boot version string as printed
2851 with the "version" command. This variable is
2852 readonly (see CONFIG_VERSION_VARIABLE).
2855 Please note that changes to some configuration parameters may take
2856 only effect after the next boot (yes, that's just like Windoze :-).
2859 Command Line Parsing:
2860 =====================
2862 There are two different command line parsers available with U-Boot:
2863 the old "simple" one, and the much more powerful "hush" shell:
2865 Old, simple command line parser:
2866 --------------------------------
2868 - supports environment variables (through setenv / saveenv commands)
2869 - several commands on one line, separated by ';'
2870 - variable substitution using "... ${name} ..." syntax
2871 - special characters ('$', ';') can be escaped by prefixing with '\',
2873 setenv bootcmd bootm \${address}
2874 - You can also escape text by enclosing in single apostrophes, for example:
2875 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
2880 - similar to Bourne shell, with control structures like
2881 if...then...else...fi, for...do...done; while...do...done,
2882 until...do...done, ...
2883 - supports environment ("global") variables (through setenv / saveenv
2884 commands) and local shell variables (through standard shell syntax
2885 "name=value"); only environment variables can be used with "run"
2891 (1) If a command line (or an environment variable executed by a "run"
2892 command) contains several commands separated by semicolon, and
2893 one of these commands fails, then the remaining commands will be
2896 (2) If you execute several variables with one call to run (i. e.
2897 calling run with a list af variables as arguments), any failing
2898 command will cause "run" to terminate, i. e. the remaining
2899 variables are not executed.
2901 Note for Redundant Ethernet Interfaces:
2902 =======================================
2904 Some boards come with redundant ethernet interfaces; U-Boot supports
2905 such configurations and is capable of automatic selection of a
2906 "working" interface when needed. MAC assignment works as follows:
2908 Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
2909 MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
2910 "eth1addr" (=>eth1), "eth2addr", ...
2912 If the network interface stores some valid MAC address (for instance
2913 in SROM), this is used as default address if there is NO correspon-
2914 ding setting in the environment; if the corresponding environment
2915 variable is set, this overrides the settings in the card; that means:
2917 o If the SROM has a valid MAC address, and there is no address in the
2918 environment, the SROM's address is used.
2920 o If there is no valid address in the SROM, and a definition in the
2921 environment exists, then the value from the environment variable is
2924 o If both the SROM and the environment contain a MAC address, and
2925 both addresses are the same, this MAC address is used.
2927 o If both the SROM and the environment contain a MAC address, and the
2928 addresses differ, the value from the environment is used and a
2931 o If neither SROM nor the environment contain a MAC address, an error
2938 U-Boot is capable of booting (and performing other auxiliary operations on)
2939 images in two formats:
2941 New uImage format (FIT)
2942 -----------------------
2944 Flexible and powerful format based on Flattened Image Tree -- FIT (similar
2945 to Flattened Device Tree). It allows the use of images with multiple
2946 components (several kernels, ramdisks, etc.), with contents protected by
2947 SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory.
2953 Old image format is based on binary files which can be basically anything,
2954 preceded by a special header; see the definitions in include/image.h for
2955 details; basically, the header defines the following image properties:
2957 * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
2958 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
2959 LynxOS, pSOS, QNX, RTEMS, ARTOS;
2960 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, ARTOS, LynxOS).
2961 * Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86,
2962 IA64, MIPS, NIOS, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
2963 Currently supported: ARM, AVR32, Intel x86, MIPS, NIOS, PowerPC).
2964 * Compression Type (uncompressed, gzip, bzip2)
2970 The header is marked by a special Magic Number, and both the header
2971 and the data portions of the image are secured against corruption by
2978 Although U-Boot should support any OS or standalone application
2979 easily, the main focus has always been on Linux during the design of
2982 U-Boot includes many features that so far have been part of some
2983 special "boot loader" code within the Linux kernel. Also, any
2984 "initrd" images to be used are no longer part of one big Linux image;
2985 instead, kernel and "initrd" are separate images. This implementation
2986 serves several purposes:
2988 - the same features can be used for other OS or standalone
2989 applications (for instance: using compressed images to reduce the
2990 Flash memory footprint)
2992 - it becomes much easier to port new Linux kernel versions because
2993 lots of low-level, hardware dependent stuff are done by U-Boot
2995 - the same Linux kernel image can now be used with different "initrd"
2996 images; of course this also means that different kernel images can
2997 be run with the same "initrd". This makes testing easier (you don't
2998 have to build a new "zImage.initrd" Linux image when you just
2999 change a file in your "initrd"). Also, a field-upgrade of the
3000 software is easier now.
3006 Porting Linux to U-Boot based systems:
3007 ---------------------------------------
3009 U-Boot cannot save you from doing all the necessary modifications to
3010 configure the Linux device drivers for use with your target hardware
3011 (no, we don't intend to provide a full virtual machine interface to
3014 But now you can ignore ALL boot loader code (in arch/ppc/mbxboot).
3016 Just make sure your machine specific header file (for instance
3017 include/asm-ppc/tqm8xx.h) includes the same definition of the Board
3018 Information structure as we define in include/u-boot.h, and make
3019 sure that your definition of IMAP_ADDR uses the same value as your
3020 U-Boot configuration in CFG_IMMR.
3023 Configuring the Linux kernel:
3024 -----------------------------
3026 No specific requirements for U-Boot. Make sure you have some root
3027 device (initial ramdisk, NFS) for your target system.
3030 Building a Linux Image:
3031 -----------------------
3033 With U-Boot, "normal" build targets like "zImage" or "bzImage" are
3034 not used. If you use recent kernel source, a new build target
3035 "uImage" will exist which automatically builds an image usable by
3036 U-Boot. Most older kernels also have support for a "pImage" target,
3037 which was introduced for our predecessor project PPCBoot and uses a
3038 100% compatible format.
3047 The "uImage" build target uses a special tool (in 'tools/mkimage') to
3048 encapsulate a compressed Linux kernel image with header information,
3049 CRC32 checksum etc. for use with U-Boot. This is what we are doing:
3051 * build a standard "vmlinux" kernel image (in ELF binary format):
3053 * convert the kernel into a raw binary image:
3055 ${CROSS_COMPILE}-objcopy -O binary \
3056 -R .note -R .comment \
3057 -S vmlinux linux.bin
3059 * compress the binary image:
3063 * package compressed binary image for U-Boot:
3065 mkimage -A ppc -O linux -T kernel -C gzip \
3066 -a 0 -e 0 -n "Linux Kernel Image" \
3067 -d linux.bin.gz uImage
3070 The "mkimage" tool can also be used to create ramdisk images for use
3071 with U-Boot, either separated from the Linux kernel image, or
3072 combined into one file. "mkimage" encapsulates the images with a 64
3073 byte header containing information about target architecture,
3074 operating system, image type, compression method, entry points, time
3075 stamp, CRC32 checksums, etc.
3077 "mkimage" can be called in two ways: to verify existing images and
3078 print the header information, or to build new images.
3080 In the first form (with "-l" option) mkimage lists the information
3081 contained in the header of an existing U-Boot image; this includes
3082 checksum verification:
3084 tools/mkimage -l image
3085 -l ==> list image header information
3087 The second form (with "-d" option) is used to build a U-Boot image
3088 from a "data file" which is used as image payload:
3090 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
3091 -n name -d data_file image
3092 -A ==> set architecture to 'arch'
3093 -O ==> set operating system to 'os'
3094 -T ==> set image type to 'type'
3095 -C ==> set compression type 'comp'
3096 -a ==> set load address to 'addr' (hex)
3097 -e ==> set entry point to 'ep' (hex)
3098 -n ==> set image name to 'name'
3099 -d ==> use image data from 'datafile'
3101 Right now, all Linux kernels for PowerPC systems use the same load
3102 address (0x00000000), but the entry point address depends on the
3105 - 2.2.x kernels have the entry point at 0x0000000C,
3106 - 2.3.x and later kernels have the entry point at 0x00000000.
3108 So a typical call to build a U-Boot image would read:
3110 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
3111 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
3112 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux.gz \
3113 > examples/uImage.TQM850L
3114 Image Name: 2.4.4 kernel for TQM850L
3115 Created: Wed Jul 19 02:34:59 2000
3116 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3117 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
3118 Load Address: 0x00000000
3119 Entry Point: 0x00000000
3121 To verify the contents of the image (or check for corruption):
3123 -> tools/mkimage -l examples/uImage.TQM850L
3124 Image Name: 2.4.4 kernel for TQM850L
3125 Created: Wed Jul 19 02:34:59 2000
3126 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3127 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
3128 Load Address: 0x00000000
3129 Entry Point: 0x00000000
3131 NOTE: for embedded systems where boot time is critical you can trade
3132 speed for memory and install an UNCOMPRESSED image instead: this
3133 needs more space in Flash, but boots much faster since it does not
3134 need to be uncompressed:
3136 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux.gz
3137 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
3138 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
3139 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux \
3140 > examples/uImage.TQM850L-uncompressed
3141 Image Name: 2.4.4 kernel for TQM850L
3142 Created: Wed Jul 19 02:34:59 2000
3143 Image Type: PowerPC Linux Kernel Image (uncompressed)
3144 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
3145 Load Address: 0x00000000
3146 Entry Point: 0x00000000
3149 Similar you can build U-Boot images from a 'ramdisk.image.gz' file
3150 when your kernel is intended to use an initial ramdisk:
3152 -> tools/mkimage -n 'Simple Ramdisk Image' \
3153 > -A ppc -O linux -T ramdisk -C gzip \
3154 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
3155 Image Name: Simple Ramdisk Image
3156 Created: Wed Jan 12 14:01:50 2000
3157 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
3158 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
3159 Load Address: 0x00000000
3160 Entry Point: 0x00000000
3163 Installing a Linux Image:
3164 -------------------------
3166 To downloading a U-Boot image over the serial (console) interface,
3167 you must convert the image to S-Record format:
3169 objcopy -I binary -O srec examples/image examples/image.srec
3171 The 'objcopy' does not understand the information in the U-Boot
3172 image header, so the resulting S-Record file will be relative to
3173 address 0x00000000. To load it to a given address, you need to
3174 specify the target address as 'offset' parameter with the 'loads'
3177 Example: install the image to address 0x40100000 (which on the
3178 TQM8xxL is in the first Flash bank):
3180 => erase 40100000 401FFFFF
3186 ## Ready for S-Record download ...
3187 ~>examples/image.srec
3188 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
3190 15989 15990 15991 15992
3191 [file transfer complete]
3193 ## Start Addr = 0x00000000
3196 You can check the success of the download using the 'iminfo' command;
3197 this includes a checksum verification so you can be sure no data
3198 corruption happened:
3202 ## Checking Image at 40100000 ...
3203 Image Name: 2.2.13 for initrd on TQM850L
3204 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3205 Data Size: 335725 Bytes = 327 kB = 0 MB
3206 Load Address: 00000000
3207 Entry Point: 0000000c
3208 Verifying Checksum ... OK
3214 The "bootm" command is used to boot an application that is stored in
3215 memory (RAM or Flash). In case of a Linux kernel image, the contents
3216 of the "bootargs" environment variable is passed to the kernel as
3217 parameters. You can check and modify this variable using the
3218 "printenv" and "setenv" commands:
3221 => printenv bootargs
3222 bootargs=root=/dev/ram
3224 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
3226 => printenv bootargs
3227 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
3230 ## Booting Linux kernel at 40020000 ...
3231 Image Name: 2.2.13 for NFS on TQM850L
3232 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3233 Data Size: 381681 Bytes = 372 kB = 0 MB
3234 Load Address: 00000000
3235 Entry Point: 0000000c
3236 Verifying Checksum ... OK
3237 Uncompressing Kernel Image ... OK
3238 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
3239 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
3240 time_init: decrementer frequency = 187500000/60
3241 Calibrating delay loop... 49.77 BogoMIPS
3242 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
3245 If you want to boot a Linux kernel with initial ram disk, you pass
3246 the memory addresses of both the kernel and the initrd image (PPBCOOT
3247 format!) to the "bootm" command:
3249 => imi 40100000 40200000
3251 ## Checking Image at 40100000 ...
3252 Image Name: 2.2.13 for initrd on TQM850L
3253 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3254 Data Size: 335725 Bytes = 327 kB = 0 MB
3255 Load Address: 00000000
3256 Entry Point: 0000000c
3257 Verifying Checksum ... OK
3259 ## Checking Image at 40200000 ...
3260 Image Name: Simple Ramdisk Image
3261 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
3262 Data Size: 566530 Bytes = 553 kB = 0 MB
3263 Load Address: 00000000
3264 Entry Point: 00000000
3265 Verifying Checksum ... OK
3267 => bootm 40100000 40200000
3268 ## Booting Linux kernel at 40100000 ...
3269 Image Name: 2.2.13 for initrd on TQM850L
3270 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3271 Data Size: 335725 Bytes = 327 kB = 0 MB
3272 Load Address: 00000000
3273 Entry Point: 0000000c
3274 Verifying Checksum ... OK
3275 Uncompressing Kernel Image ... OK
3276 ## Loading RAMDisk Image at 40200000 ...
3277 Image Name: Simple Ramdisk Image
3278 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
3279 Data Size: 566530 Bytes = 553 kB = 0 MB
3280 Load Address: 00000000
3281 Entry Point: 00000000
3282 Verifying Checksum ... OK
3283 Loading Ramdisk ... OK
3284 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
3285 Boot arguments: root=/dev/ram
3286 time_init: decrementer frequency = 187500000/60
3287 Calibrating delay loop... 49.77 BogoMIPS
3289 RAMDISK: Compressed image found at block 0
3290 VFS: Mounted root (ext2 filesystem).
3294 Boot Linux and pass a flat device tree:
3297 First, U-Boot must be compiled with the appropriate defines. See the section
3298 titled "Linux Kernel Interface" above for a more in depth explanation. The
3299 following is an example of how to start a kernel and pass an updated
3305 oft=oftrees/mpc8540ads.dtb
3306 => tftp $oftaddr $oft
3307 Speed: 1000, full duplex
3309 TFTP from server 192.168.1.1; our IP address is 192.168.1.101
3310 Filename 'oftrees/mpc8540ads.dtb'.
3311 Load address: 0x300000
3314 Bytes transferred = 4106 (100a hex)
3315 => tftp $loadaddr $bootfile
3316 Speed: 1000, full duplex
3318 TFTP from server 192.168.1.1; our IP address is 192.168.1.2
3320 Load address: 0x200000
3321 Loading:############
3323 Bytes transferred = 1029407 (fb51f hex)
3328 => bootm $loadaddr - $oftaddr
3329 ## Booting image at 00200000 ...
3330 Image Name: Linux-2.6.17-dirty
3331 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3332 Data Size: 1029343 Bytes = 1005.2 kB
3333 Load Address: 00000000
3334 Entry Point: 00000000
3335 Verifying Checksum ... OK
3336 Uncompressing Kernel Image ... OK
3337 Booting using flat device tree at 0x300000
3338 Using MPC85xx ADS machine description
3339 Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb
3343 More About U-Boot Image Types:
3344 ------------------------------
3346 U-Boot supports the following image types:
3348 "Standalone Programs" are directly runnable in the environment
3349 provided by U-Boot; it is expected that (if they behave
3350 well) you can continue to work in U-Boot after return from
3351 the Standalone Program.
3352 "OS Kernel Images" are usually images of some Embedded OS which
3353 will take over control completely. Usually these programs
3354 will install their own set of exception handlers, device
3355 drivers, set up the MMU, etc. - this means, that you cannot
3356 expect to re-enter U-Boot except by resetting the CPU.
3357 "RAMDisk Images" are more or less just data blocks, and their
3358 parameters (address, size) are passed to an OS kernel that is
3360 "Multi-File Images" contain several images, typically an OS
3361 (Linux) kernel image and one or more data images like
3362 RAMDisks. This construct is useful for instance when you want
3363 to boot over the network using BOOTP etc., where the boot
3364 server provides just a single image file, but you want to get
3365 for instance an OS kernel and a RAMDisk image.
3367 "Multi-File Images" start with a list of image sizes, each
3368 image size (in bytes) specified by an "uint32_t" in network
3369 byte order. This list is terminated by an "(uint32_t)0".
3370 Immediately after the terminating 0 follow the images, one by
3371 one, all aligned on "uint32_t" boundaries (size rounded up to
3372 a multiple of 4 bytes).
3374 "Firmware Images" are binary images containing firmware (like
3375 U-Boot or FPGA images) which usually will be programmed to
3378 "Script files" are command sequences that will be executed by
3379 U-Boot's command interpreter; this feature is especially
3380 useful when you configure U-Boot to use a real shell (hush)
3381 as command interpreter.
3387 One of the features of U-Boot is that you can dynamically load and
3388 run "standalone" applications, which can use some resources of
3389 U-Boot like console I/O functions or interrupt services.
3391 Two simple examples are included with the sources:
3396 'examples/hello_world.c' contains a small "Hello World" Demo
3397 application; it is automatically compiled when you build U-Boot.
3398 It's configured to run at address 0x00040004, so you can play with it
3402 ## Ready for S-Record download ...
3403 ~>examples/hello_world.srec
3404 1 2 3 4 5 6 7 8 9 10 11 ...
3405 [file transfer complete]
3407 ## Start Addr = 0x00040004
3409 => go 40004 Hello World! This is a test.
3410 ## Starting application at 0x00040004 ...
3421 Hit any key to exit ...
3423 ## Application terminated, rc = 0x0
3425 Another example, which demonstrates how to register a CPM interrupt
3426 handler with the U-Boot code, can be found in 'examples/timer.c'.
3427 Here, a CPM timer is set up to generate an interrupt every second.
3428 The interrupt service routine is trivial, just printing a '.'
3429 character, but this is just a demo program. The application can be
3430 controlled by the following keys:
3432 ? - print current values og the CPM Timer registers
3433 b - enable interrupts and start timer
3434 e - stop timer and disable interrupts
3435 q - quit application
3438 ## Ready for S-Record download ...
3439 ~>examples/timer.srec
3440 1 2 3 4 5 6 7 8 9 10 11 ...
3441 [file transfer complete]
3443 ## Start Addr = 0x00040004
3446 ## Starting application at 0x00040004 ...
3449 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
3452 [q, b, e, ?] Set interval 1000000 us
3455 [q, b, e, ?] ........
3456 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
3459 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
3462 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
3465 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
3467 [q, b, e, ?] ...Stopping timer
3469 [q, b, e, ?] ## Application terminated, rc = 0x0
3475 Over time, many people have reported problems when trying to use the
3476 "minicom" terminal emulation program for serial download. I (wd)
3477 consider minicom to be broken, and recommend not to use it. Under
3478 Unix, I recommend to use C-Kermit for general purpose use (and
3479 especially for kermit binary protocol download ("loadb" command), and
3480 use "cu" for S-Record download ("loads" command).
3482 Nevertheless, if you absolutely want to use it try adding this
3483 configuration to your "File transfer protocols" section:
3485 Name Program Name U/D FullScr IO-Red. Multi
3486 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
3487 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
3493 Starting at version 0.9.2, U-Boot supports NetBSD both as host
3494 (build U-Boot) and target system (boots NetBSD/mpc8xx).
3496 Building requires a cross environment; it is known to work on
3497 NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
3498 need gmake since the Makefiles are not compatible with BSD make).
3499 Note that the cross-powerpc package does not install include files;
3500 attempting to build U-Boot will fail because <machine/ansi.h> is
3501 missing. This file has to be installed and patched manually:
3503 # cd /usr/pkg/cross/powerpc-netbsd/include
3505 # ln -s powerpc machine
3506 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
3507 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
3509 Native builds *don't* work due to incompatibilities between native
3510 and U-Boot include files.
3512 Booting assumes that (the first part of) the image booted is a
3513 stage-2 loader which in turn loads and then invokes the kernel
3514 proper. Loader sources will eventually appear in the NetBSD source
3515 tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
3516 meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz
3519 Implementation Internals:
3520 =========================
3522 The following is not intended to be a complete description of every
3523 implementation detail. However, it should help to understand the
3524 inner workings of U-Boot and make it easier to port it to custom
3528 Initial Stack, Global Data:
3529 ---------------------------
3531 The implementation of U-Boot is complicated by the fact that U-Boot
3532 starts running out of ROM (flash memory), usually without access to
3533 system RAM (because the memory controller is not initialized yet).
3534 This means that we don't have writable Data or BSS segments, and BSS
3535 is not initialized as zero. To be able to get a C environment working
3536 at all, we have to allocate at least a minimal stack. Implementation
3537 options for this are defined and restricted by the CPU used: Some CPU
3538 models provide on-chip memory (like the IMMR area on MPC8xx and
3539 MPC826x processors), on others (parts of) the data cache can be
3540 locked as (mis-) used as memory, etc.
3542 Chris Hallinan posted a good summary of these issues to the
3543 u-boot-users mailing list:
3545 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
3546 From: "Chris Hallinan" <clh@net1plus.com>
3547 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
3550 Correct me if I'm wrong, folks, but the way I understand it
3551 is this: Using DCACHE as initial RAM for Stack, etc, does not
3552 require any physical RAM backing up the cache. The cleverness
3553 is that the cache is being used as a temporary supply of
3554 necessary storage before the SDRAM controller is setup. It's
3555 beyond the scope of this list to expain the details, but you
3556 can see how this works by studying the cache architecture and
3557 operation in the architecture and processor-specific manuals.
3559 OCM is On Chip Memory, which I believe the 405GP has 4K. It
3560 is another option for the system designer to use as an
3561 initial stack/ram area prior to SDRAM being available. Either
3562 option should work for you. Using CS 4 should be fine if your
3563 board designers haven't used it for something that would
3564 cause you grief during the initial boot! It is frequently not
3567 CFG_INIT_RAM_ADDR should be somewhere that won't interfere
3568 with your processor/board/system design. The default value
3569 you will find in any recent u-boot distribution in
3570 walnut.h should work for you. I'd set it to a value larger
3571 than your SDRAM module. If you have a 64MB SDRAM module, set
3572 it above 400_0000. Just make sure your board has no resources
3573 that are supposed to respond to that address! That code in
3574 start.S has been around a while and should work as is when
3575 you get the config right.
3580 It is essential to remember this, since it has some impact on the C
3581 code for the initialization procedures:
3583 * Initialized global data (data segment) is read-only. Do not attempt
3586 * Do not use any unitialized global data (or implicitely initialized
3587 as zero data - BSS segment) at all - this is undefined, initiali-
3588 zation is performed later (when relocating to RAM).
3590 * Stack space is very limited. Avoid big data buffers or things like
3593 Having only the stack as writable memory limits means we cannot use
3594 normal global data to share information beween the code. But it
3595 turned out that the implementation of U-Boot can be greatly
3596 simplified by making a global data structure (gd_t) available to all
3597 functions. We could pass a pointer to this data as argument to _all_
3598 functions, but this would bloat the code. Instead we use a feature of
3599 the GCC compiler (Global Register Variables) to share the data: we
3600 place a pointer (gd) to the global data into a register which we
3601 reserve for this purpose.
3603 When choosing a register for such a purpose we are restricted by the
3604 relevant (E)ABI specifications for the current architecture, and by
3605 GCC's implementation.
3607 For PowerPC, the following registers have specific use:
3609 R2: reserved for system use
3610 R3-R4: parameter passing and return values
3611 R5-R10: parameter passing
3612 R13: small data area pointer
3616 (U-Boot also uses R14 as internal GOT pointer.)
3618 ==> U-Boot will use R2 to hold a pointer to the global data
3620 Note: on PPC, we could use a static initializer (since the
3621 address of the global data structure is known at compile time),
3622 but it turned out that reserving a register results in somewhat
3623 smaller code - although the code savings are not that big (on
3624 average for all boards 752 bytes for the whole U-Boot image,
3625 624 text + 127 data).
3627 On Blackfin, the normal C ABI (except for P5) is followed as documented here:
3628 http://docs.blackfin.uclinux.org/doku.php?id=application_binary_interface
3630 ==> U-Boot will use P5 to hold a pointer to the global data
3632 On ARM, the following registers are used:
3634 R0: function argument word/integer result
3635 R1-R3: function argument word
3637 R10: stack limit (used only if stack checking if enabled)
3638 R11: argument (frame) pointer
3639 R12: temporary workspace
3642 R15: program counter
3644 ==> U-Boot will use R8 to hold a pointer to the global data
3646 NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope,
3647 or current versions of GCC may "optimize" the code too much.
3652 U-Boot runs in system state and uses physical addresses, i.e. the
3653 MMU is not used either for address mapping nor for memory protection.
3655 The available memory is mapped to fixed addresses using the memory
3656 controller. In this process, a contiguous block is formed for each
3657 memory type (Flash, SDRAM, SRAM), even when it consists of several
3658 physical memory banks.
3660 U-Boot is installed in the first 128 kB of the first Flash bank (on
3661 TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
3662 booting and sizing and initializing DRAM, the code relocates itself
3663 to the upper end of DRAM. Immediately below the U-Boot code some
3664 memory is reserved for use by malloc() [see CFG_MALLOC_LEN
3665 configuration setting]. Below that, a structure with global Board
3666 Info data is placed, followed by the stack (growing downward).
3668 Additionally, some exception handler code is copied to the low 8 kB
3669 of DRAM (0x00000000 ... 0x00001FFF).
3671 So a typical memory configuration with 16 MB of DRAM could look like
3674 0x0000 0000 Exception Vector code
3677 0x0000 2000 Free for Application Use
3683 0x00FB FF20 Monitor Stack (Growing downward)
3684 0x00FB FFAC Board Info Data and permanent copy of global data
3685 0x00FC 0000 Malloc Arena
3688 0x00FE 0000 RAM Copy of Monitor Code
3689 ... eventually: LCD or video framebuffer
3690 ... eventually: pRAM (Protected RAM - unchanged by reset)
3691 0x00FF FFFF [End of RAM]
3694 System Initialization:
3695 ----------------------
3697 In the reset configuration, U-Boot starts at the reset entry point
3698 (on most PowerPC systens at address 0x00000100). Because of the reset
3699 configuration for CS0# this is a mirror of the onboard Flash memory.
3700 To be able to re-map memory U-Boot then jumps to its link address.
3701 To be able to implement the initialization code in C, a (small!)
3702 initial stack is set up in the internal Dual Ported RAM (in case CPUs
3703 which provide such a feature like MPC8xx or MPC8260), or in a locked
3704 part of the data cache. After that, U-Boot initializes the CPU core,
3705 the caches and the SIU.
3707 Next, all (potentially) available memory banks are mapped using a
3708 preliminary mapping. For example, we put them on 512 MB boundaries
3709 (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
3710 on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
3711 programmed for SDRAM access. Using the temporary configuration, a
3712 simple memory test is run that determines the size of the SDRAM
3715 When there is more than one SDRAM bank, and the banks are of
3716 different size, the largest is mapped first. For equal size, the first
3717 bank (CS2#) is mapped first. The first mapping is always for address
3718 0x00000000, with any additional banks following immediately to create
3719 contiguous memory starting from 0.
3721 Then, the monitor installs itself at the upper end of the SDRAM area
3722 and allocates memory for use by malloc() and for the global Board
3723 Info data; also, the exception vector code is copied to the low RAM
3724 pages, and the final stack is set up.
3726 Only after this relocation will you have a "normal" C environment;
3727 until that you are restricted in several ways, mostly because you are
3728 running from ROM, and because the code will have to be relocated to a
3732 U-Boot Porting Guide:
3733 ----------------------
3735 [Based on messages by Jerry Van Baren in the U-Boot-Users mailing
3739 int main (int argc, char *argv[])
3741 sighandler_t no_more_time;
3743 signal (SIGALRM, no_more_time);
3744 alarm (PROJECT_DEADLINE - toSec (3 * WEEK));
3746 if (available_money > available_manpower) {
3747 pay consultant to port U-Boot;
3751 Download latest U-Boot source;
3753 Subscribe to u-boot-users mailing list;
3756 email ("Hi, I am new to U-Boot, how do I get started?");
3760 Read the README file in the top level directory;
3761 Read http://www.denx.de/twiki/bin/view/DULG/Manual ;
3762 Read the source, Luke;
3765 if (available_money > toLocalCurrency ($2500)) {
3768 Add a lot of aggravation and time;
3771 Create your own board support subdirectory;
3773 Create your own board config file;
3777 Add / modify source code;
3781 email ("Hi, I am having problems...");
3783 Send patch file to Wolfgang;
3788 void no_more_time (int sig)
3797 All contributions to U-Boot should conform to the Linux kernel
3798 coding style; see the file "Documentation/CodingStyle" and the script
3799 "scripts/Lindent" in your Linux kernel source directory. In sources
3800 originating from U-Boot a style corresponding to "Lindent -pcs" (adding
3801 spaces before parameters to function calls) is actually used.
3803 Source files originating from a different project (for example the
3804 MTD subsystem) are generally exempt from these guidelines and are not
3805 reformated to ease subsequent migration to newer versions of those
3808 Please note that U-Boot is implemented in C (and to some small parts in
3809 Assembler); no C++ is used, so please do not use C++ style comments (//)
3812 Please also stick to the following formatting rules:
3813 - remove any trailing white space
3814 - use TAB characters for indentation, not spaces
3815 - make sure NOT to use DOS '\r\n' line feeds
3816 - do not add more than 2 empty lines to source files
3817 - do not add trailing empty lines to source files
3819 Submissions which do not conform to the standards may be returned
3820 with a request to reformat the changes.
3826 Since the number of patches for U-Boot is growing, we need to
3827 establish some rules. Submissions which do not conform to these rules
3828 may be rejected, even when they contain important and valuable stuff.
3830 Patches shall be sent to the u-boot-users mailing list.
3832 Please see http://www.denx.de/wiki/UBoot/Patches for details.
3834 When you send a patch, please include the following information with
3837 * For bug fixes: a description of the bug and how your patch fixes
3838 this bug. Please try to include a way of demonstrating that the
3839 patch actually fixes something.
3841 * For new features: a description of the feature and your
3844 * A CHANGELOG entry as plaintext (separate from the patch)
3846 * For major contributions, your entry to the CREDITS file
3848 * When you add support for a new board, don't forget to add this
3849 board to the MAKEALL script, too.
3851 * If your patch adds new configuration options, don't forget to
3852 document these in the README file.
3854 * The patch itself. If you are using git (which is *strongly*
3855 recommended) you can easily generate the patch using the
3856 "git-format-patch". If you then use "git-send-email" to send it to
3857 the U-Boot mailing list, you will avoid most of the common problems
3858 with some other mail clients.
3860 If you cannot use git, use "diff -purN OLD NEW". If your version of
3861 diff does not support these options, then get the latest version of
3864 The current directory when running this command shall be the parent
3865 directory of the U-Boot source tree (i. e. please make sure that
3866 your patch includes sufficient directory information for the
3869 We prefer patches as plain text. MIME attachments are discouraged,
3870 and compressed attachments must not be used.
3872 * If one logical set of modifications affects or creates several
3873 files, all these changes shall be submitted in a SINGLE patch file.
3875 * Changesets that contain different, unrelated modifications shall be
3876 submitted as SEPARATE patches, one patch per changeset.
3881 * Before sending the patch, run the MAKEALL script on your patched
3882 source tree and make sure that no errors or warnings are reported
3883 for any of the boards.
3885 * Keep your modifications to the necessary minimum: A patch
3886 containing several unrelated changes or arbitrary reformats will be
3887 returned with a request to re-formatting / split it.
3889 * If you modify existing code, make sure that your new code does not
3890 add to the memory footprint of the code ;-) Small is beautiful!
3891 When adding new features, these should compile conditionally only
3892 (using #ifdef), and the resulting code with the new feature
3893 disabled must not need more memory than the old code without your
3896 * Remember that there is a size limit of 40 kB per message on the
3897 u-boot-users mailing list. Bigger patches will be moderated. If
3898 they are reasonable and not bigger than 100 kB, they will be
3899 acknowledged. Even bigger patches should be avoided.
projects / platform / kernel / u-boot.git / blob