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.
754 CONFIG_E1000_FALLBACK_MAC
755 default MAC for empty eeprom after production.
758 Support for Intel 82557/82559/82559ER chips.
759 Optional CONFIG_EEPRO100_SROM_WRITE enables eeprom
760 write routine for first time initialisation.
763 Support for Digital 2114x chips.
764 Optional CONFIG_TULIP_SELECT_MEDIA for board specific
765 modem chip initialisation (KS8761/QS6611).
768 Support for National dp83815 chips.
771 Support for National dp8382[01] gigabit chips.
773 - NETWORK Support (other):
775 CONFIG_DRIVER_LAN91C96
776 Support for SMSC's LAN91C96 chips.
779 Define this to hold the physical address
780 of the LAN91C96's I/O space
782 CONFIG_LAN91C96_USE_32_BIT
783 Define this to enable 32 bit addressing
785 CONFIG_DRIVER_SMC91111
786 Support for SMSC's LAN91C111 chip
789 Define this to hold the physical address
790 of the device (I/O space)
792 CONFIG_SMC_USE_32_BIT
793 Define this if data bus is 32 bits
795 CONFIG_SMC_USE_IOFUNCS
796 Define this to use i/o functions instead of macros
797 (some hardware wont work with macros)
800 At the moment only the UHCI host controller is
801 supported (PIP405, MIP405, MPC5200); define
802 CONFIG_USB_UHCI to enable it.
803 define CONFIG_USB_KEYBOARD to enable the USB Keyboard
804 and define CONFIG_USB_STORAGE to enable the USB
807 Supported are USB Keyboards and USB Floppy drives
809 MPC5200 USB requires additional defines:
811 for 528 MHz Clock: 0x0001bbbb
813 for differential drivers: 0x00001000
814 for single ended drivers: 0x00005000
816 May be defined to allow interrupt polling
817 instead of using asynchronous interrupts
820 Define the below if you wish to use the USB console.
821 Once firmware is rebuilt from a serial console issue the
822 command "setenv stdin usbtty; setenv stdout usbtty" and
823 attach your usb cable. The Unix command "dmesg" should print
824 it has found a new device. The environment variable usbtty
825 can be set to gserial or cdc_acm to enable your device to
826 appear to a USB host as a Linux gserial device or a
827 Common Device Class Abstract Control Model serial device.
828 If you select usbtty = gserial you should be able to enumerate
830 # modprobe usbserial vendor=0xVendorID product=0xProductID
831 else if using cdc_acm, simply setting the environment
832 variable usbtty to be cdc_acm should suffice. The following
833 might be defined in YourBoardName.h
836 Define this to build a UDC device
839 Define this to have a tty type of device available to
840 talk to the UDC device
842 CFG_CONSOLE_IS_IN_ENV
843 Define this if you want stdin, stdout &/or stderr to
847 CFG_USB_EXTC_CLK 0xBLAH
848 Derive USB clock from external clock "blah"
849 - CFG_USB_EXTC_CLK 0x02
851 CFG_USB_BRG_CLK 0xBLAH
852 Derive USB clock from brgclk
853 - CFG_USB_BRG_CLK 0x04
855 If you have a USB-IF assigned VendorID then you may wish to
856 define your own vendor specific values either in BoardName.h
857 or directly in usbd_vendor_info.h. If you don't define
858 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME,
859 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot
860 should pretend to be a Linux device to it's target host.
862 CONFIG_USBD_MANUFACTURER
863 Define this string as the name of your company for
864 - CONFIG_USBD_MANUFACTURER "my company"
866 CONFIG_USBD_PRODUCT_NAME
867 Define this string as the name of your product
868 - CONFIG_USBD_PRODUCT_NAME "acme usb device"
871 Define this as your assigned Vendor ID from the USB
872 Implementors Forum. This *must* be a genuine Vendor ID
873 to avoid polluting the USB namespace.
874 - CONFIG_USBD_VENDORID 0xFFFF
876 CONFIG_USBD_PRODUCTID
877 Define this as the unique Product ID
879 - CONFIG_USBD_PRODUCTID 0xFFFF
883 The MMC controller on the Intel PXA is supported. To
884 enable this define CONFIG_MMC. The MMC can be
885 accessed from the boot prompt by mapping the device
886 to physical memory similar to flash. Command line is
887 enabled with CONFIG_CMD_MMC. The MMC driver also works with
888 the FAT fs. This is enabled with CONFIG_CMD_FAT.
890 - Journaling Flash filesystem support:
891 CONFIG_JFFS2_NAND, CONFIG_JFFS2_NAND_OFF, CONFIG_JFFS2_NAND_SIZE,
892 CONFIG_JFFS2_NAND_DEV
893 Define these for a default partition on a NAND device
895 CFG_JFFS2_FIRST_SECTOR,
896 CFG_JFFS2_FIRST_BANK, CFG_JFFS2_NUM_BANKS
897 Define these for a default partition on a NOR device
900 Define this to create an own partition. You have to provide a
901 function struct part_info* jffs2_part_info(int part_num)
903 If you define only one JFFS2 partition you may also want to
904 #define CFG_JFFS_SINGLE_PART 1
905 to disable the command chpart. This is the default when you
906 have not defined a custom partition
911 Define this to enable standard (PC-Style) keyboard
915 Standard PC keyboard driver with US (is default) and
916 GERMAN key layout (switch via environment 'keymap=de') support.
917 Export function i8042_kbd_init, i8042_tstc and i8042_getc
918 for cfb_console. Supports cursor blinking.
923 Define this to enable video support (for output to
928 Enable Chips & Technologies 69000 Video chip
930 CONFIG_VIDEO_SMI_LYNXEM
931 Enable Silicon Motion SMI 712/710/810 Video chip. The
932 video output is selected via environment 'videoout'
933 (1 = LCD and 2 = CRT). If videoout is undefined, CRT is
936 For the CT69000 and SMI_LYNXEM drivers, videomode is
937 selected via environment 'videomode'. Two diferent ways
939 - "videomode=num" 'num' is a standard LiLo mode numbers.
940 Following standard modes are supported (* is default):
942 Colors 640x480 800x600 1024x768 1152x864 1280x1024
943 -------------+---------------------------------------------
944 8 bits | 0x301* 0x303 0x305 0x161 0x307
945 15 bits | 0x310 0x313 0x316 0x162 0x319
946 16 bits | 0x311 0x314 0x317 0x163 0x31A
947 24 bits | 0x312 0x315 0x318 ? 0x31B
948 -------------+---------------------------------------------
949 (i.e. setenv videomode 317; saveenv; reset;)
951 - "videomode=bootargs" all the video parameters are parsed
952 from the bootargs. (See drivers/video/videomodes.c)
955 CONFIG_VIDEO_SED13806
956 Enable Epson SED13806 driver. This driver supports 8bpp
957 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP
958 or CONFIG_VIDEO_SED13806_16BPP
963 Define this to enable a custom keyboard support.
964 This simply calls drv_keyboard_init() which must be
965 defined in your board-specific files.
966 The only board using this so far is RBC823.
968 - LCD Support: CONFIG_LCD
970 Define this to enable LCD support (for output to LCD
971 display); also select one of the supported displays
972 by defining one of these:
974 CONFIG_NEC_NL6448AC33:
976 NEC NL6448AC33-18. Active, color, single scan.
978 CONFIG_NEC_NL6448BC20
980 NEC NL6448BC20-08. 6.5", 640x480.
981 Active, color, single scan.
983 CONFIG_NEC_NL6448BC33_54
985 NEC NL6448BC33-54. 10.4", 640x480.
986 Active, color, single scan.
990 Sharp 320x240. Active, color, single scan.
991 It isn't 16x9, and I am not sure what it is.
993 CONFIG_SHARP_LQ64D341
995 Sharp LQ64D341 display, 640x480.
996 Active, color, single scan.
1000 HLD1045 display, 640x480.
1001 Active, color, single scan.
1005 Optrex CBL50840-2 NF-FW 99 22 M5
1007 Hitachi LMG6912RPFC-00T
1011 320x240. Black & white.
1013 Normally display is black on white background; define
1014 CFG_WHITE_ON_BLACK to get it inverted.
1016 - Splash Screen Support: CONFIG_SPLASH_SCREEN
1018 If this option is set, the environment is checked for
1019 a variable "splashimage". If found, the usual display
1020 of logo, copyright and system information on the LCD
1021 is suppressed and the BMP image at the address
1022 specified in "splashimage" is loaded instead. The
1023 console is redirected to the "nulldev", too. This
1024 allows for a "silent" boot where a splash screen is
1025 loaded very quickly after power-on.
1027 - Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP
1029 If this option is set, additionally to standard BMP
1030 images, gzipped BMP images can be displayed via the
1031 splashscreen support or the bmp command.
1033 - Compression support:
1036 If this option is set, support for bzip2 compressed
1037 images is included. If not, only uncompressed and gzip
1038 compressed images are supported.
1040 NOTE: the bzip2 algorithm requires a lot of RAM, so
1041 the malloc area (as defined by CFG_MALLOC_LEN) should
1047 The address of PHY on MII bus.
1049 CONFIG_PHY_CLOCK_FREQ (ppc4xx)
1051 The clock frequency of the MII bus
1055 If this option is set, support for speed/duplex
1056 detection of Gigabit PHY is included.
1058 CONFIG_PHY_RESET_DELAY
1060 Some PHY like Intel LXT971A need extra delay after
1061 reset before any MII register access is possible.
1062 For such PHY, set this option to the usec delay
1063 required. (minimum 300usec for LXT971A)
1065 CONFIG_PHY_CMD_DELAY (ppc4xx)
1067 Some PHY like Intel LXT971A need extra delay after
1068 command issued before MII status register can be read
1075 Define a default value for ethernet address to use
1076 for the respective ethernet interface, in case this
1077 is not determined automatically.
1082 Define a default value for the IP address to use for
1083 the default ethernet interface, in case this is not
1084 determined through e.g. bootp.
1086 - Server IP address:
1089 Defines a default value for theIP address of a TFTP
1090 server to contact when using the "tftboot" command.
1092 - Multicast TFTP Mode:
1095 Defines whether you want to support multicast TFTP as per
1096 rfc-2090; for example to work with atftp. Lets lots of targets
1097 tftp down the same boot image concurrently. Note: the ethernet
1098 driver in use must provide a function: mcast() to join/leave a
1101 CONFIG_BOOTP_RANDOM_DELAY
1102 - BOOTP Recovery Mode:
1103 CONFIG_BOOTP_RANDOM_DELAY
1105 If you have many targets in a network that try to
1106 boot using BOOTP, you may want to avoid that all
1107 systems send out BOOTP requests at precisely the same
1108 moment (which would happen for instance at recovery
1109 from a power failure, when all systems will try to
1110 boot, thus flooding the BOOTP server. Defining
1111 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
1112 inserted before sending out BOOTP requests. The
1113 following delays are inserted then:
1115 1st BOOTP request: delay 0 ... 1 sec
1116 2nd BOOTP request: delay 0 ... 2 sec
1117 3rd BOOTP request: delay 0 ... 4 sec
1119 BOOTP requests: delay 0 ... 8 sec
1121 - DHCP Advanced Options:
1122 You can fine tune the DHCP functionality by defining
1123 CONFIG_BOOTP_* symbols:
1125 CONFIG_BOOTP_SUBNETMASK
1126 CONFIG_BOOTP_GATEWAY
1127 CONFIG_BOOTP_HOSTNAME
1128 CONFIG_BOOTP_NISDOMAIN
1129 CONFIG_BOOTP_BOOTPATH
1130 CONFIG_BOOTP_BOOTFILESIZE
1133 CONFIG_BOOTP_SEND_HOSTNAME
1134 CONFIG_BOOTP_NTPSERVER
1135 CONFIG_BOOTP_TIMEOFFSET
1136 CONFIG_BOOTP_VENDOREX
1138 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip
1139 environment variable, not the BOOTP server.
1141 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS
1142 serverip from a DHCP server, it is possible that more
1143 than one DNS serverip is offered to the client.
1144 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS
1145 serverip will be stored in the additional environment
1146 variable "dnsip2". The first DNS serverip is always
1147 stored in the variable "dnsip", when CONFIG_BOOTP_DNS
1150 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable
1151 to do a dynamic update of a DNS server. To do this, they
1152 need the hostname of the DHCP requester.
1153 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content
1154 of the "hostname" environment variable is passed as
1155 option 12 to the DHCP server.
1157 CONFIG_BOOTP_DHCP_REQUEST_DELAY
1159 A 32bit value in microseconds for a delay between
1160 receiving a "DHCP Offer" and sending the "DHCP Request".
1161 This fixes a problem with certain DHCP servers that don't
1162 respond 100% of the time to a "DHCP request". E.g. On an
1163 AT91RM9200 processor running at 180MHz, this delay needed
1164 to be *at least* 15,000 usec before a Windows Server 2003
1165 DHCP server would reply 100% of the time. I recommend at
1166 least 50,000 usec to be safe. The alternative is to hope
1167 that one of the retries will be successful but note that
1168 the DHCP timeout and retry process takes a longer than
1172 CONFIG_CDP_DEVICE_ID
1174 The device id used in CDP trigger frames.
1176 CONFIG_CDP_DEVICE_ID_PREFIX
1178 A two character string which is prefixed to the MAC address
1183 A printf format string which contains the ascii name of
1184 the port. Normally is set to "eth%d" which sets
1185 eth0 for the first ethernet, eth1 for the second etc.
1187 CONFIG_CDP_CAPABILITIES
1189 A 32bit integer which indicates the device capabilities;
1190 0x00000010 for a normal host which does not forwards.
1194 An ascii string containing the version of the software.
1198 An ascii string containing the name of the platform.
1202 A 32bit integer sent on the trigger.
1204 CONFIG_CDP_POWER_CONSUMPTION
1206 A 16bit integer containing the power consumption of the
1207 device in .1 of milliwatts.
1209 CONFIG_CDP_APPLIANCE_VLAN_TYPE
1211 A byte containing the id of the VLAN.
1213 - Status LED: CONFIG_STATUS_LED
1215 Several configurations allow to display the current
1216 status using a LED. For instance, the LED will blink
1217 fast while running U-Boot code, stop blinking as
1218 soon as a reply to a BOOTP request was received, and
1219 start blinking slow once the Linux kernel is running
1220 (supported by a status LED driver in the Linux
1221 kernel). Defining CONFIG_STATUS_LED enables this
1224 - CAN Support: CONFIG_CAN_DRIVER
1226 Defining CONFIG_CAN_DRIVER enables CAN driver support
1227 on those systems that support this (optional)
1228 feature, like the TQM8xxL modules.
1230 - I2C Support: CONFIG_HARD_I2C | CONFIG_SOFT_I2C
1232 These enable I2C serial bus commands. Defining either of
1233 (but not both of) CONFIG_HARD_I2C or CONFIG_SOFT_I2C will
1234 include the appropriate I2C driver for the selected cpu.
1236 This will allow you to use i2c commands at the u-boot
1237 command line (as long as you set CONFIG_CMD_I2C in
1238 CONFIG_COMMANDS) and communicate with i2c based realtime
1239 clock chips. See common/cmd_i2c.c for a description of the
1240 command line interface.
1242 CONFIG_I2C_CMD_TREE is a recommended option that places
1243 all I2C commands under a single 'i2c' root command. The
1244 older 'imm', 'imd', 'iprobe' etc. commands are considered
1245 deprecated and may disappear in the future.
1247 CONFIG_HARD_I2C selects a hardware I2C controller.
1249 CONFIG_SOFT_I2C configures u-boot to use a software (aka
1250 bit-banging) driver instead of CPM or similar hardware
1253 There are several other quantities that must also be
1254 defined when you define CONFIG_HARD_I2C or CONFIG_SOFT_I2C.
1256 In both cases you will need to define CFG_I2C_SPEED
1257 to be the frequency (in Hz) at which you wish your i2c bus
1258 to run and CFG_I2C_SLAVE to be the address of this node (ie
1259 the cpu's i2c node address).
1261 Now, the u-boot i2c code for the mpc8xx (cpu/mpc8xx/i2c.c)
1262 sets the cpu up as a master node and so its address should
1263 therefore be cleared to 0 (See, eg, MPC823e User's Manual
1264 p.16-473). So, set CFG_I2C_SLAVE to 0.
1266 That's all that's required for CONFIG_HARD_I2C.
1268 If you use the software i2c interface (CONFIG_SOFT_I2C)
1269 then the following macros need to be defined (examples are
1270 from include/configs/lwmon.h):
1274 (Optional). Any commands necessary to enable the I2C
1275 controller or configure ports.
1277 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
1281 (Only for MPC8260 CPU). The I/O port to use (the code
1282 assumes both bits are on the same port). Valid values
1283 are 0..3 for ports A..D.
1287 The code necessary to make the I2C data line active
1288 (driven). If the data line is open collector, this
1291 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
1295 The code necessary to make the I2C data line tri-stated
1296 (inactive). If the data line is open collector, this
1299 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
1303 Code that returns TRUE if the I2C data line is high,
1306 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
1310 If <bit> is TRUE, sets the I2C data line high. If it
1311 is FALSE, it clears it (low).
1313 eg: #define I2C_SDA(bit) \
1314 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
1315 else immr->im_cpm.cp_pbdat &= ~PB_SDA
1319 If <bit> is TRUE, sets the I2C clock line high. If it
1320 is FALSE, it clears it (low).
1322 eg: #define I2C_SCL(bit) \
1323 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
1324 else immr->im_cpm.cp_pbdat &= ~PB_SCL
1328 This delay is invoked four times per clock cycle so this
1329 controls the rate of data transfer. The data rate thus
1330 is 1 / (I2C_DELAY * 4). Often defined to be something
1333 #define I2C_DELAY udelay(2)
1337 When a board is reset during an i2c bus transfer
1338 chips might think that the current transfer is still
1339 in progress. On some boards it is possible to access
1340 the i2c SCLK line directly, either by using the
1341 processor pin as a GPIO or by having a second pin
1342 connected to the bus. If this option is defined a
1343 custom i2c_init_board() routine in boards/xxx/board.c
1344 is run early in the boot sequence.
1346 CONFIG_I2CFAST (PPC405GP|PPC405EP only)
1348 This option enables configuration of bi_iic_fast[] flags
1349 in u-boot bd_info structure based on u-boot environment
1350 variable "i2cfast". (see also i2cfast)
1352 CONFIG_I2C_MULTI_BUS
1354 This option allows the use of multiple I2C buses, each of which
1355 must have a controller. At any point in time, only one bus is
1356 active. To switch to a different bus, use the 'i2c dev' command.
1357 Note that bus numbering is zero-based.
1361 This option specifies a list of I2C devices that will be skipped
1362 when the 'i2c probe' command is issued (or 'iprobe' using the legacy
1363 command). If CONFIG_I2C_MULTI_BUS is set, specify a list of bus-device
1364 pairs. Otherwise, specify a 1D array of device addresses
1367 #undef CONFIG_I2C_MULTI_BUS
1368 #define CFG_I2C_NOPROBES {0x50,0x68}
1370 will skip addresses 0x50 and 0x68 on a board with one I2C bus
1372 #define CONFIG_I2C_MULTI_BUS
1373 #define CFG_I2C_MULTI_NOPROBES {{0,0x50},{0,0x68},{1,0x54}}
1375 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1
1379 If defined, then this indicates the I2C bus number for DDR SPD.
1380 If not defined, then U-Boot assumes that SPD is on I2C bus 0.
1384 If defined, then this indicates the I2C bus number for the RTC.
1385 If not defined, then U-Boot assumes that RTC is on I2C bus 0.
1389 If defined, then this indicates the I2C bus number for the DTT.
1390 If not defined, then U-Boot assumes that DTT is on I2C bus 0.
1394 Define this option if you want to use Freescale's I2C driver in
1395 drivers/i2c/fsl_i2c.c.
1398 - SPI Support: CONFIG_SPI
1400 Enables SPI driver (so far only tested with
1401 SPI EEPROM, also an instance works with Crystal A/D and
1402 D/As on the SACSng board)
1406 Enables extended (16-bit) SPI EEPROM addressing.
1407 (symmetrical to CONFIG_I2C_X)
1411 Enables a software (bit-bang) SPI driver rather than
1412 using hardware support. This is a general purpose
1413 driver that only requires three general I/O port pins
1414 (two outputs, one input) to function. If this is
1415 defined, the board configuration must define several
1416 SPI configuration items (port pins to use, etc). For
1417 an example, see include/configs/sacsng.h.
1421 Enables a hardware SPI driver for general-purpose reads
1422 and writes. As with CONFIG_SOFT_SPI, the board configuration
1423 must define a list of chip-select function pointers.
1424 Currently supported on some MPC8xxx processors. For an
1425 example, see include/configs/mpc8349emds.h.
1427 - FPGA Support: CONFIG_FPGA
1429 Enables FPGA subsystem.
1431 CONFIG_FPGA_<vendor>
1433 Enables support for specific chip vendors.
1436 CONFIG_FPGA_<family>
1438 Enables support for FPGA family.
1439 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX)
1443 Specify the number of FPGA devices to support.
1445 CFG_FPGA_PROG_FEEDBACK
1447 Enable printing of hash marks during FPGA configuration.
1451 Enable checks on FPGA configuration interface busy
1452 status by the configuration function. This option
1453 will require a board or device specific function to
1458 If defined, a function that provides delays in the FPGA
1459 configuration driver.
1461 CFG_FPGA_CHECK_CTRLC
1462 Allow Control-C to interrupt FPGA configuration
1464 CFG_FPGA_CHECK_ERROR
1466 Check for configuration errors during FPGA bitfile
1467 loading. For example, abort during Virtex II
1468 configuration if the INIT_B line goes low (which
1469 indicated a CRC error).
1473 Maximum time to wait for the INIT_B line to deassert
1474 after PROB_B has been deasserted during a Virtex II
1475 FPGA configuration sequence. The default time is 500
1480 Maximum time to wait for BUSY to deassert during
1481 Virtex II FPGA configuration. The default is 5 mS.
1483 CFG_FPGA_WAIT_CONFIG
1485 Time to wait after FPGA configuration. The default is
1488 - Configuration Management:
1491 If defined, this string will be added to the U-Boot
1492 version information (U_BOOT_VERSION)
1494 - Vendor Parameter Protection:
1496 U-Boot considers the values of the environment
1497 variables "serial#" (Board Serial Number) and
1498 "ethaddr" (Ethernet Address) to be parameters that
1499 are set once by the board vendor / manufacturer, and
1500 protects these variables from casual modification by
1501 the user. Once set, these variables are read-only,
1502 and write or delete attempts are rejected. You can
1503 change this behviour:
1505 If CONFIG_ENV_OVERWRITE is #defined in your config
1506 file, the write protection for vendor parameters is
1507 completely disabled. Anybody can change or delete
1510 Alternatively, if you #define _both_ CONFIG_ETHADDR
1511 _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
1512 ethernet address is installed in the environment,
1513 which can be changed exactly ONCE by the user. [The
1514 serial# is unaffected by this, i. e. it remains
1520 Define this variable to enable the reservation of
1521 "protected RAM", i. e. RAM which is not overwritten
1522 by U-Boot. Define CONFIG_PRAM to hold the number of
1523 kB you want to reserve for pRAM. You can overwrite
1524 this default value by defining an environment
1525 variable "pram" to the number of kB you want to
1526 reserve. Note that the board info structure will
1527 still show the full amount of RAM. If pRAM is
1528 reserved, a new environment variable "mem" will
1529 automatically be defined to hold the amount of
1530 remaining RAM in a form that can be passed as boot
1531 argument to Linux, for instance like that:
1533 setenv bootargs ... mem=\${mem}
1536 This way you can tell Linux not to use this memory,
1537 either, which results in a memory region that will
1538 not be affected by reboots.
1540 *WARNING* If your board configuration uses automatic
1541 detection of the RAM size, you must make sure that
1542 this memory test is non-destructive. So far, the
1543 following board configurations are known to be
1546 ETX094, IVMS8, IVML24, SPD8xx, TQM8xxL,
1547 HERMES, IP860, RPXlite, LWMON, LANTEC,
1548 PCU_E, FLAGADM, TQM8260
1553 Define this variable to stop the system in case of a
1554 fatal error, so that you have to reset it manually.
1555 This is probably NOT a good idea for an embedded
1556 system where you want to system to reboot
1557 automatically as fast as possible, but it may be
1558 useful during development since you can try to debug
1559 the conditions that lead to the situation.
1561 CONFIG_NET_RETRY_COUNT
1563 This variable defines the number of retries for
1564 network operations like ARP, RARP, TFTP, or BOOTP
1565 before giving up the operation. If not defined, a
1566 default value of 5 is used.
1568 - Command Interpreter:
1569 CONFIG_AUTO_COMPLETE
1571 Enable auto completion of commands using TAB.
1573 Note that this feature has NOT been implemented yet
1574 for the "hush" shell.
1579 Define this variable to enable the "hush" shell (from
1580 Busybox) as command line interpreter, thus enabling
1581 powerful command line syntax like
1582 if...then...else...fi conditionals or `&&' and '||'
1583 constructs ("shell scripts").
1585 If undefined, you get the old, much simpler behaviour
1586 with a somewhat smaller memory footprint.
1591 This defines the secondary prompt string, which is
1592 printed when the command interpreter needs more input
1593 to complete a command. Usually "> ".
1597 In the current implementation, the local variables
1598 space and global environment variables space are
1599 separated. Local variables are those you define by
1600 simply typing `name=value'. To access a local
1601 variable later on, you have write `$name' or
1602 `${name}'; to execute the contents of a variable
1603 directly type `$name' at the command prompt.
1605 Global environment variables are those you use
1606 setenv/printenv to work with. To run a command stored
1607 in such a variable, you need to use the run command,
1608 and you must not use the '$' sign to access them.
1610 To store commands and special characters in a
1611 variable, please use double quotation marks
1612 surrounding the whole text of the variable, instead
1613 of the backslashes before semicolons and special
1616 - Commandline Editing and History:
1617 CONFIG_CMDLINE_EDITING
1619 Enable editiong and History functions for interactive
1620 commandline input operations
1622 - Default Environment:
1623 CONFIG_EXTRA_ENV_SETTINGS
1625 Define this to contain any number of null terminated
1626 strings (variable = value pairs) that will be part of
1627 the default environment compiled into the boot image.
1629 For example, place something like this in your
1630 board's config file:
1632 #define CONFIG_EXTRA_ENV_SETTINGS \
1636 Warning: This method is based on knowledge about the
1637 internal format how the environment is stored by the
1638 U-Boot code. This is NOT an official, exported
1639 interface! Although it is unlikely that this format
1640 will change soon, there is no guarantee either.
1641 You better know what you are doing here.
1643 Note: overly (ab)use of the default environment is
1644 discouraged. Make sure to check other ways to preset
1645 the environment like the autoscript function or the
1648 - DataFlash Support:
1649 CONFIG_HAS_DATAFLASH
1651 Defining this option enables DataFlash features and
1652 allows to read/write in Dataflash via the standard
1655 - SystemACE Support:
1658 Adding this option adds support for Xilinx SystemACE
1659 chips attached via some sort of local bus. The address
1660 of the chip must alsh be defined in the
1661 CFG_SYSTEMACE_BASE macro. For example:
1663 #define CONFIG_SYSTEMACE
1664 #define CFG_SYSTEMACE_BASE 0xf0000000
1666 When SystemACE support is added, the "ace" device type
1667 becomes available to the fat commands, i.e. fatls.
1669 - TFTP Fixed UDP Port:
1672 If this is defined, the environment variable tftpsrcp
1673 is used to supply the TFTP UDP source port value.
1674 If tftpsrcp isn't defined, the normal pseudo-random port
1675 number generator is used.
1677 Also, the environment variable tftpdstp is used to supply
1678 the TFTP UDP destination port value. If tftpdstp isn't
1679 defined, the normal port 69 is used.
1681 The purpose for tftpsrcp is to allow a TFTP server to
1682 blindly start the TFTP transfer using the pre-configured
1683 target IP address and UDP port. This has the effect of
1684 "punching through" the (Windows XP) firewall, allowing
1685 the remainder of the TFTP transfer to proceed normally.
1686 A better solution is to properly configure the firewall,
1687 but sometimes that is not allowed.
1689 - Show boot progress:
1690 CONFIG_SHOW_BOOT_PROGRESS
1692 Defining this option allows to add some board-
1693 specific code (calling a user-provided function
1694 "show_boot_progress(int)") that enables you to show
1695 the system's boot progress on some display (for
1696 example, some LED's) on your board. At the moment,
1697 the following checkpoints are implemented:
1699 Legacy uImage format:
1702 1 common/cmd_bootm.c before attempting to boot an image
1703 -1 common/cmd_bootm.c Image header has bad magic number
1704 2 common/cmd_bootm.c Image header has correct magic number
1705 -2 common/cmd_bootm.c Image header has bad checksum
1706 3 common/cmd_bootm.c Image header has correct checksum
1707 -3 common/cmd_bootm.c Image data has bad checksum
1708 4 common/cmd_bootm.c Image data has correct checksum
1709 -4 common/cmd_bootm.c Image is for unsupported architecture
1710 5 common/cmd_bootm.c Architecture check OK
1711 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi)
1712 6 common/cmd_bootm.c Image Type check OK
1713 -6 common/cmd_bootm.c gunzip uncompression error
1714 -7 common/cmd_bootm.c Unimplemented compression type
1715 7 common/cmd_bootm.c Uncompression OK
1716 8 common/cmd_bootm.c No uncompress/copy overwrite error
1717 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX)
1719 9 common/image.c Start initial ramdisk verification
1720 -10 common/image.c Ramdisk header has bad magic number
1721 -11 common/image.c Ramdisk header has bad checksum
1722 10 common/image.c Ramdisk header is OK
1723 -12 common/image.c Ramdisk data has bad checksum
1724 11 common/image.c Ramdisk data has correct checksum
1725 12 common/image.c Ramdisk verification complete, start loading
1726 -13 common/image.c Wrong Image Type (not PPC Linux Ramdisk)
1727 13 common/image.c Start multifile image verification
1728 14 common/image.c No initial ramdisk, no multifile, continue.
1730 15 lib_<arch>/bootm.c All preparation done, transferring control to OS
1732 -30 lib_ppc/board.c Fatal error, hang the system
1733 -31 post/post.c POST test failed, detected by post_output_backlog()
1734 -32 post/post.c POST test failed, detected by post_run_single()
1736 34 common/cmd_doc.c before loading a Image from a DOC device
1737 -35 common/cmd_doc.c Bad usage of "doc" command
1738 35 common/cmd_doc.c correct usage of "doc" command
1739 -36 common/cmd_doc.c No boot device
1740 36 common/cmd_doc.c correct boot device
1741 -37 common/cmd_doc.c Unknown Chip ID on boot device
1742 37 common/cmd_doc.c correct chip ID found, device available
1743 -38 common/cmd_doc.c Read Error on boot device
1744 38 common/cmd_doc.c reading Image header from DOC device OK
1745 -39 common/cmd_doc.c Image header has bad magic number
1746 39 common/cmd_doc.c Image header has correct magic number
1747 -40 common/cmd_doc.c Error reading Image from DOC device
1748 40 common/cmd_doc.c Image header has correct magic number
1749 41 common/cmd_ide.c before loading a Image from a IDE device
1750 -42 common/cmd_ide.c Bad usage of "ide" command
1751 42 common/cmd_ide.c correct usage of "ide" command
1752 -43 common/cmd_ide.c No boot device
1753 43 common/cmd_ide.c boot device found
1754 -44 common/cmd_ide.c Device not available
1755 44 common/cmd_ide.c Device available
1756 -45 common/cmd_ide.c wrong partition selected
1757 45 common/cmd_ide.c partition selected
1758 -46 common/cmd_ide.c Unknown partition table
1759 46 common/cmd_ide.c valid partition table found
1760 -47 common/cmd_ide.c Invalid partition type
1761 47 common/cmd_ide.c correct partition type
1762 -48 common/cmd_ide.c Error reading Image Header on boot device
1763 48 common/cmd_ide.c reading Image Header from IDE device OK
1764 -49 common/cmd_ide.c Image header has bad magic number
1765 49 common/cmd_ide.c Image header has correct magic number
1766 -50 common/cmd_ide.c Image header has bad checksum
1767 50 common/cmd_ide.c Image header has correct checksum
1768 -51 common/cmd_ide.c Error reading Image from IDE device
1769 51 common/cmd_ide.c reading Image from IDE device OK
1770 52 common/cmd_nand.c before loading a Image from a NAND device
1771 -53 common/cmd_nand.c Bad usage of "nand" command
1772 53 common/cmd_nand.c correct usage of "nand" command
1773 -54 common/cmd_nand.c No boot device
1774 54 common/cmd_nand.c boot device found
1775 -55 common/cmd_nand.c Unknown Chip ID on boot device
1776 55 common/cmd_nand.c correct chip ID found, device available
1777 -56 common/cmd_nand.c Error reading Image Header on boot device
1778 56 common/cmd_nand.c reading Image Header from NAND device OK
1779 -57 common/cmd_nand.c Image header has bad magic number
1780 57 common/cmd_nand.c Image header has correct magic number
1781 -58 common/cmd_nand.c Error reading Image from NAND device
1782 58 common/cmd_nand.c reading Image from NAND device OK
1784 -60 common/env_common.c Environment has a bad CRC, using default
1786 64 net/eth.c starting with Ethernetconfiguration.
1787 -64 net/eth.c no Ethernet found.
1788 65 net/eth.c Ethernet found.
1790 -80 common/cmd_net.c usage wrong
1791 80 common/cmd_net.c before calling NetLoop()
1792 -81 common/cmd_net.c some error in NetLoop() occured
1793 81 common/cmd_net.c NetLoop() back without error
1794 -82 common/cmd_net.c size == 0 (File with size 0 loaded)
1795 82 common/cmd_net.c trying automatic boot
1796 83 common/cmd_net.c running autoscript
1797 -83 common/cmd_net.c some error in automatic boot or autoscript
1798 84 common/cmd_net.c end without errors
1803 100 common/cmd_bootm.c Kernel FIT Image has correct format
1804 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format
1805 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration
1806 -101 common/cmd_bootm.c Can't get configuration for kernel subimage
1807 102 common/cmd_bootm.c Kernel unit name specified
1808 -103 common/cmd_bootm.c Can't get kernel subimage node offset
1809 103 common/cmd_bootm.c Found configuration node
1810 104 common/cmd_bootm.c Got kernel subimage node offset
1811 -104 common/cmd_bootm.c Kernel subimage hash verification failed
1812 105 common/cmd_bootm.c Kernel subimage hash verification OK
1813 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture
1814 106 common/cmd_bootm.c Architecture check OK
1815 -106 common/cmd_bootm.c Kernel subimage has wrong typea
1816 107 common/cmd_bootm.c Kernel subimge type OK
1817 -107 common/cmd_bootm.c Can't get kernel subimage data/size
1818 108 common/cmd_bootm.c Got kernel subimage data/size
1819 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT)
1820 -109 common/cmd_bootm.c Can't get kernel subimage type
1821 -110 common/cmd_bootm.c Can't get kernel subimage comp
1822 -111 common/cmd_bootm.c Can't get kernel subimage os
1823 -112 common/cmd_bootm.c Can't get kernel subimage load address
1824 -113 common/cmd_bootm.c Image uncompress/copy overwrite error
1826 120 common/image.c Start initial ramdisk verification
1827 -120 common/image.c Ramdisk FIT image has incorrect format
1828 121 common/image.c Ramdisk FIT image has correct format
1829 122 common/image.c No Ramdisk subimage unit name, using configuration
1830 -122 common/image.c Can't get configuration for ramdisk subimage
1831 123 common/image.c Ramdisk unit name specified
1832 -124 common/image.c Can't get ramdisk subimage node offset
1833 125 common/image.c Got ramdisk subimage node offset
1834 -125 common/image.c Ramdisk subimage hash verification failed
1835 126 common/image.c Ramdisk subimage hash verification OK
1836 -126 common/image.c Ramdisk subimage for unsupported architecture
1837 127 common/image.c Architecture check OK
1838 -127 common/image.c Can't get ramdisk subimage data/size
1839 128 common/image.c Got ramdisk subimage data/size
1840 129 common/image.c Can't get ramdisk load address
1841 -129 common/image.c Got ramdisk load address
1843 -130 common/cmd_doc.c Icorrect FIT image format
1844 131 common/cmd_doc.c FIT image format OK
1846 -140 common/cmd_ide.c Icorrect FIT image format
1847 141 common/cmd_ide.c FIT image format OK
1849 -150 common/cmd_nand.c Icorrect FIT image format
1850 151 common/cmd_nand.c FIT image format OK
1856 [so far only for SMDK2400 and TRAB boards]
1858 - Modem support endable:
1859 CONFIG_MODEM_SUPPORT
1861 - RTS/CTS Flow control enable:
1864 - Modem debug support:
1865 CONFIG_MODEM_SUPPORT_DEBUG
1867 Enables debugging stuff (char screen[1024], dbg())
1868 for modem support. Useful only with BDI2000.
1870 - Interrupt support (PPC):
1872 There are common interrupt_init() and timer_interrupt()
1873 for all PPC archs. interrupt_init() calls interrupt_init_cpu()
1874 for cpu specific initialization. interrupt_init_cpu()
1875 should set decrementer_count to appropriate value. If
1876 cpu resets decrementer automatically after interrupt
1877 (ppc4xx) it should set decrementer_count to zero.
1878 timer_interrupt() calls timer_interrupt_cpu() for cpu
1879 specific handling. If board has watchdog / status_led
1880 / other_activity_monitor it works automatically from
1881 general timer_interrupt().
1885 In the target system modem support is enabled when a
1886 specific key (key combination) is pressed during
1887 power-on. Otherwise U-Boot will boot normally
1888 (autoboot). The key_pressed() fuction is called from
1889 board_init(). Currently key_pressed() is a dummy
1890 function, returning 1 and thus enabling modem
1893 If there are no modem init strings in the
1894 environment, U-Boot proceed to autoboot; the
1895 previous output (banner, info printfs) will be
1898 See also: doc/README.Modem
1901 Configuration Settings:
1902 -----------------------
1904 - CFG_LONGHELP: Defined when you want long help messages included;
1905 undefine this when you're short of memory.
1907 - CFG_PROMPT: This is what U-Boot prints on the console to
1908 prompt for user input.
1910 - CFG_CBSIZE: Buffer size for input from the Console
1912 - CFG_PBSIZE: Buffer size for Console output
1914 - CFG_MAXARGS: max. Number of arguments accepted for monitor commands
1916 - CFG_BARGSIZE: Buffer size for Boot Arguments which are passed to
1917 the application (usually a Linux kernel) when it is
1920 - CFG_BAUDRATE_TABLE:
1921 List of legal baudrate settings for this board.
1923 - CFG_CONSOLE_INFO_QUIET
1924 Suppress display of console information at boot.
1926 - CFG_CONSOLE_IS_IN_ENV
1927 If the board specific function
1928 extern int overwrite_console (void);
1929 returns 1, the stdin, stderr and stdout are switched to the
1930 serial port, else the settings in the environment are used.
1932 - CFG_CONSOLE_OVERWRITE_ROUTINE
1933 Enable the call to overwrite_console().
1935 - CFG_CONSOLE_ENV_OVERWRITE
1936 Enable overwrite of previous console environment settings.
1938 - CFG_MEMTEST_START, CFG_MEMTEST_END:
1939 Begin and End addresses of the area used by the
1943 Enable an alternate, more extensive memory test.
1945 - CFG_MEMTEST_SCRATCH:
1946 Scratch address used by the alternate memory test
1947 You only need to set this if address zero isn't writeable
1949 - CFG_MEM_TOP_HIDE (PPC only):
1950 If CFG_MEM_TOP_HIDE is defined in the board config header,
1951 this specified memory area will get subtracted from the top
1952 (end) of ram and won't get "touched" at all by U-Boot. By
1953 fixing up gd->ram_size the Linux kernel should gets passed
1954 the now "corrected" memory size and won't touch it either.
1955 This should work for arch/ppc and arch/powerpc. Only Linux
1956 board ports in arch/powerpc with bootwrapper support that
1957 recalculate the memory size from the SDRAM controller setup
1958 will have to get fixed in Linux additionally.
1960 This option can be used as a workaround for the 440EPx/GRx
1961 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't
1964 WARNING: Please make sure that this value is a multiple of
1965 the Linux page size (normally 4k). If this is not the case,
1966 then the end address of the Linux memory will be located at a
1967 non page size aligned address and this could cause major
1970 - CFG_TFTP_LOADADDR:
1971 Default load address for network file downloads
1973 - CFG_LOADS_BAUD_CHANGE:
1974 Enable temporary baudrate change while serial download
1977 Physical start address of SDRAM. _Must_ be 0 here.
1980 Physical start address of Motherboard I/O (if using a
1984 Physical start address of Flash memory.
1987 Physical start address of boot monitor code (set by
1988 make config files to be same as the text base address
1989 (TEXT_BASE) used when linking) - same as
1990 CFG_FLASH_BASE when booting from flash.
1993 Size of memory reserved for monitor code, used to
1994 determine _at_compile_time_ (!) if the environment is
1995 embedded within the U-Boot image, or in a separate
1999 Size of DRAM reserved for malloc() use.
2002 Normally compressed uImages are limited to an
2003 uncompressed size of 8 MBytes. If this is not enough,
2004 you can define CFG_BOOTM_LEN in your board config file
2005 to adjust this setting to your needs.
2008 Maximum size of memory mapped by the startup code of
2009 the Linux kernel; all data that must be processed by
2010 the Linux kernel (bd_info, boot arguments, eventually
2011 initrd image) must be put below this limit.
2013 - CFG_MAX_FLASH_BANKS:
2014 Max number of Flash memory banks
2016 - CFG_MAX_FLASH_SECT:
2017 Max number of sectors on a Flash chip
2019 - CFG_FLASH_ERASE_TOUT:
2020 Timeout for Flash erase operations (in ms)
2022 - CFG_FLASH_WRITE_TOUT:
2023 Timeout for Flash write operations (in ms)
2025 - CFG_FLASH_LOCK_TOUT
2026 Timeout for Flash set sector lock bit operation (in ms)
2028 - CFG_FLASH_UNLOCK_TOUT
2029 Timeout for Flash clear lock bits operation (in ms)
2031 - CFG_FLASH_PROTECTION
2032 If defined, hardware flash sectors protection is used
2033 instead of U-Boot software protection.
2035 - CFG_DIRECT_FLASH_TFTP:
2037 Enable TFTP transfers directly to flash memory;
2038 without this option such a download has to be
2039 performed in two steps: (1) download to RAM, and (2)
2040 copy from RAM to flash.
2042 The two-step approach is usually more reliable, since
2043 you can check if the download worked before you erase
2044 the flash, but in some situations (when sytem RAM is
2045 too limited to allow for a tempory copy of the
2046 downloaded image) this option may be very useful.
2049 Define if the flash driver uses extra elements in the
2050 common flash structure for storing flash geometry.
2052 - CFG_FLASH_CFI_DRIVER
2053 This option also enables the building of the cfi_flash driver
2054 in the drivers directory
2056 - CFG_FLASH_QUIET_TEST
2057 If this option is defined, the common CFI flash doesn't
2058 print it's warning upon not recognized FLASH banks. This
2059 is useful, if some of the configured banks are only
2060 optionally available.
2062 - CONFIG_FLASH_SHOW_PROGRESS
2063 If defined (must be an integer), print out countdown
2064 digits and dots. Recommended value: 45 (9..1) for 80
2065 column displays, 15 (3..1) for 40 column displays.
2067 - CFG_RX_ETH_BUFFER:
2068 Defines the number of ethernet receive buffers. On some
2069 ethernet controllers it is recommended to set this value
2070 to 8 or even higher (EEPRO100 or 405 EMAC), since all
2071 buffers can be full shortly after enabling the interface
2072 on high ethernet traffic.
2073 Defaults to 4 if not defined.
2075 The following definitions that deal with the placement and management
2076 of environment data (variable area); in general, we support the
2077 following configurations:
2079 - CFG_ENV_IS_IN_FLASH:
2081 Define this if the environment is in flash memory.
2083 a) The environment occupies one whole flash sector, which is
2084 "embedded" in the text segment with the U-Boot code. This
2085 happens usually with "bottom boot sector" or "top boot
2086 sector" type flash chips, which have several smaller
2087 sectors at the start or the end. For instance, such a
2088 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In
2089 such a case you would place the environment in one of the
2090 4 kB sectors - with U-Boot code before and after it. With
2091 "top boot sector" type flash chips, you would put the
2092 environment in one of the last sectors, leaving a gap
2093 between U-Boot and the environment.
2097 Offset of environment data (variable area) to the
2098 beginning of flash memory; for instance, with bottom boot
2099 type flash chips the second sector can be used: the offset
2100 for this sector is given here.
2102 CFG_ENV_OFFSET is used relative to CFG_FLASH_BASE.
2106 This is just another way to specify the start address of
2107 the flash sector containing the environment (instead of
2110 - CFG_ENV_SECT_SIZE:
2112 Size of the sector containing the environment.
2115 b) Sometimes flash chips have few, equal sized, BIG sectors.
2116 In such a case you don't want to spend a whole sector for
2121 If you use this in combination with CFG_ENV_IS_IN_FLASH
2122 and CFG_ENV_SECT_SIZE, you can specify to use only a part
2123 of this flash sector for the environment. This saves
2124 memory for the RAM copy of the environment.
2126 It may also save flash memory if you decide to use this
2127 when your environment is "embedded" within U-Boot code,
2128 since then the remainder of the flash sector could be used
2129 for U-Boot code. It should be pointed out that this is
2130 STRONGLY DISCOURAGED from a robustness point of view:
2131 updating the environment in flash makes it always
2132 necessary to erase the WHOLE sector. If something goes
2133 wrong before the contents has been restored from a copy in
2134 RAM, your target system will be dead.
2136 - CFG_ENV_ADDR_REDUND
2139 These settings describe a second storage area used to hold
2140 a redundand copy of the environment data, so that there is
2141 a valid backup copy in case there is a power failure during
2142 a "saveenv" operation.
2144 BE CAREFUL! Any changes to the flash layout, and some changes to the
2145 source code will make it necessary to adapt <board>/u-boot.lds*
2149 - CFG_ENV_IS_IN_NVRAM:
2151 Define this if you have some non-volatile memory device
2152 (NVRAM, battery buffered SRAM) which you want to use for the
2158 These two #defines are used to determin the memory area you
2159 want to use for environment. It is assumed that this memory
2160 can just be read and written to, without any special
2163 BE CAREFUL! The first access to the environment happens quite early
2164 in U-Boot initalization (when we try to get the setting of for the
2165 console baudrate). You *MUST* have mappend your NVRAM area then, or
2168 Please note that even with NVRAM we still use a copy of the
2169 environment in RAM: we could work on NVRAM directly, but we want to
2170 keep settings there always unmodified except somebody uses "saveenv"
2171 to save the current settings.
2174 - CFG_ENV_IS_IN_EEPROM:
2176 Use this if you have an EEPROM or similar serial access
2177 device and a driver for it.
2182 These two #defines specify the offset and size of the
2183 environment area within the total memory of your EEPROM.
2185 - CFG_I2C_EEPROM_ADDR:
2186 If defined, specified the chip address of the EEPROM device.
2187 The default address is zero.
2189 - CFG_EEPROM_PAGE_WRITE_BITS:
2190 If defined, the number of bits used to address bytes in a
2191 single page in the EEPROM device. A 64 byte page, for example
2192 would require six bits.
2194 - CFG_EEPROM_PAGE_WRITE_DELAY_MS:
2195 If defined, the number of milliseconds to delay between
2196 page writes. The default is zero milliseconds.
2198 - CFG_I2C_EEPROM_ADDR_LEN:
2199 The length in bytes of the EEPROM memory array address. Note
2200 that this is NOT the chip address length!
2202 - CFG_I2C_EEPROM_ADDR_OVERFLOW:
2203 EEPROM chips that implement "address overflow" are ones
2204 like Catalyst 24WC04/08/16 which has 9/10/11 bits of
2205 address and the extra bits end up in the "chip address" bit
2206 slots. This makes a 24WC08 (1Kbyte) chip look like four 256
2209 Note that we consider the length of the address field to
2210 still be one byte because the extra address bits are hidden
2211 in the chip address.
2214 The size in bytes of the EEPROM device.
2217 - CFG_ENV_IS_IN_DATAFLASH:
2219 Define this if you have a DataFlash memory device which you
2220 want to use for the environment.
2226 These three #defines specify the offset and size of the
2227 environment area within the total memory of your DataFlash placed
2228 at the specified address.
2230 - CFG_ENV_IS_IN_NAND:
2232 Define this if you have a NAND device which you want to use
2233 for the environment.
2238 These two #defines specify the offset and size of the environment
2239 area within the first NAND device.
2241 - CFG_ENV_OFFSET_REDUND
2243 This setting describes a second storage area of CFG_ENV_SIZE
2244 size used to hold a redundant copy of the environment data,
2245 so that there is a valid backup copy in case there is a
2246 power failure during a "saveenv" operation.
2248 Note: CFG_ENV_OFFSET and CFG_ENV_OFFSET_REDUND must be aligned
2249 to a block boundary, and CFG_ENV_SIZE must be a multiple of
2250 the NAND devices block size.
2252 - CFG_SPI_INIT_OFFSET
2254 Defines offset to the initial SPI buffer area in DPRAM. The
2255 area is used at an early stage (ROM part) if the environment
2256 is configured to reside in the SPI EEPROM: We need a 520 byte
2257 scratch DPRAM area. It is used between the two initialization
2258 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems
2259 to be a good choice since it makes it far enough from the
2260 start of the data area as well as from the stack pointer.
2262 Please note that the environment is read-only until the monitor
2263 has been relocated to RAM and a RAM copy of the environment has been
2264 created; also, when using EEPROM you will have to use getenv_r()
2265 until then to read environment variables.
2267 The environment is protected by a CRC32 checksum. Before the monitor
2268 is relocated into RAM, as a result of a bad CRC you will be working
2269 with the compiled-in default environment - *silently*!!! [This is
2270 necessary, because the first environment variable we need is the
2271 "baudrate" setting for the console - if we have a bad CRC, we don't
2272 have any device yet where we could complain.]
2274 Note: once the monitor has been relocated, then it will complain if
2275 the default environment is used; a new CRC is computed as soon as you
2276 use the "saveenv" command to store a valid environment.
2278 - CFG_FAULT_ECHO_LINK_DOWN:
2279 Echo the inverted Ethernet link state to the fault LED.
2281 Note: If this option is active, then CFG_FAULT_MII_ADDR
2282 also needs to be defined.
2284 - CFG_FAULT_MII_ADDR:
2285 MII address of the PHY to check for the Ethernet link state.
2287 - CFG_64BIT_VSPRINTF:
2288 Makes vsprintf (and all *printf functions) support printing
2289 of 64bit values by using the L quantifier
2291 - CFG_64BIT_STRTOUL:
2292 Adds simple_strtoull that returns a 64bit value
2294 Low Level (hardware related) configuration options:
2295 ---------------------------------------------------
2297 - CFG_CACHELINE_SIZE:
2298 Cache Line Size of the CPU.
2301 Default address of the IMMR after system reset.
2303 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU,
2304 and RPXsuper) to be able to adjust the position of
2305 the IMMR register after a reset.
2307 - Floppy Disk Support:
2308 CFG_FDC_DRIVE_NUMBER
2310 the default drive number (default value 0)
2314 defines the spacing between fdc chipset registers
2319 defines the offset of register from address. It
2320 depends on which part of the data bus is connected to
2321 the fdc chipset. (default value 0)
2323 If CFG_ISA_IO_STRIDE CFG_ISA_IO_OFFSET and
2324 CFG_FDC_DRIVE_NUMBER are undefined, they take their
2327 if CFG_FDC_HW_INIT is defined, then the function
2328 fdc_hw_init() is called at the beginning of the FDC
2329 setup. fdc_hw_init() must be provided by the board
2330 source code. It is used to make hardware dependant
2333 - CFG_IMMR: Physical address of the Internal Memory.
2334 DO NOT CHANGE unless you know exactly what you're
2335 doing! (11-4) [MPC8xx/82xx systems only]
2337 - CFG_INIT_RAM_ADDR:
2339 Start address of memory area that can be used for
2340 initial data and stack; please note that this must be
2341 writable memory that is working WITHOUT special
2342 initialization, i. e. you CANNOT use normal RAM which
2343 will become available only after programming the
2344 memory controller and running certain initialization
2347 U-Boot uses the following memory types:
2348 - MPC8xx and MPC8260: IMMR (internal memory of the CPU)
2349 - MPC824X: data cache
2350 - PPC4xx: data cache
2352 - CFG_GBL_DATA_OFFSET:
2354 Offset of the initial data structure in the memory
2355 area defined by CFG_INIT_RAM_ADDR. Usually
2356 CFG_GBL_DATA_OFFSET is chosen such that the initial
2357 data is located at the end of the available space
2358 (sometimes written as (CFG_INIT_RAM_END -
2359 CFG_INIT_DATA_SIZE), and the initial stack is just
2360 below that area (growing from (CFG_INIT_RAM_ADDR +
2361 CFG_GBL_DATA_OFFSET) downward.
2364 On the MPC824X (or other systems that use the data
2365 cache for initial memory) the address chosen for
2366 CFG_INIT_RAM_ADDR is basically arbitrary - it must
2367 point to an otherwise UNUSED address space between
2368 the top of RAM and the start of the PCI space.
2370 - CFG_SIUMCR: SIU Module Configuration (11-6)
2372 - CFG_SYPCR: System Protection Control (11-9)
2374 - CFG_TBSCR: Time Base Status and Control (11-26)
2376 - CFG_PISCR: Periodic Interrupt Status and Control (11-31)
2378 - CFG_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30)
2380 - CFG_SCCR: System Clock and reset Control Register (15-27)
2382 - CFG_OR_TIMING_SDRAM:
2386 periodic timer for refresh
2388 - CFG_DER: Debug Event Register (37-47)
2390 - FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CFG_REMAP_OR_AM,
2391 CFG_PRELIM_OR_AM, CFG_OR_TIMING_FLASH, CFG_OR0_REMAP,
2392 CFG_OR0_PRELIM, CFG_BR0_PRELIM, CFG_OR1_REMAP, CFG_OR1_PRELIM,
2394 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
2396 - SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
2397 CFG_OR_TIMING_SDRAM, CFG_OR2_PRELIM, CFG_BR2_PRELIM,
2398 CFG_OR3_PRELIM, CFG_BR3_PRELIM:
2399 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
2401 - CFG_MAMR_PTA, CFG_MPTPR_2BK_4K, CFG_MPTPR_1BK_4K, CFG_MPTPR_2BK_8K,
2402 CFG_MPTPR_1BK_8K, CFG_MAMR_8COL, CFG_MAMR_9COL:
2403 Machine Mode Register and Memory Periodic Timer
2404 Prescaler definitions (SDRAM timing)
2406 - CFG_I2C_UCODE_PATCH, CFG_I2C_DPMEM_OFFSET [0x1FC0]:
2407 enable I2C microcode relocation patch (MPC8xx);
2408 define relocation offset in DPRAM [DSP2]
2410 - CFG_SMC_UCODE_PATCH, CFG_SMC_DPMEM_OFFSET [0x1FC0]:
2411 enable SMC microcode relocation patch (MPC8xx);
2412 define relocation offset in DPRAM [SMC1]
2414 - CFG_SPI_UCODE_PATCH, CFG_SPI_DPMEM_OFFSET [0x1FC0]:
2415 enable SPI microcode relocation patch (MPC8xx);
2416 define relocation offset in DPRAM [SCC4]
2419 Use OSCM clock mode on MBX8xx board. Be careful,
2420 wrong setting might damage your board. Read
2421 doc/README.MBX before setting this variable!
2423 - CFG_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only)
2424 Offset of the bootmode word in DPRAM used by post
2425 (Power On Self Tests). This definition overrides
2426 #define'd default value in commproc.h resp.
2429 - CFG_PCI_SLV_MEM_LOCAL, CFG_PCI_SLV_MEM_BUS, CFG_PICMR0_MASK_ATTRIB,
2430 CFG_PCI_MSTR0_LOCAL, CFG_PCIMSK0_MASK, CFG_PCI_MSTR1_LOCAL,
2431 CFG_PCIMSK1_MASK, CFG_PCI_MSTR_MEM_LOCAL, CFG_PCI_MSTR_MEM_BUS,
2432 CFG_CPU_PCI_MEM_START, CFG_PCI_MSTR_MEM_SIZE, CFG_POCMR0_MASK_ATTRIB,
2433 CFG_PCI_MSTR_MEMIO_LOCAL, CFG_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START,
2434 CFG_PCI_MSTR_MEMIO_SIZE, CFG_POCMR1_MASK_ATTRIB, CFG_PCI_MSTR_IO_LOCAL,
2435 CFG_PCI_MSTR_IO_BUS, CFG_CPU_PCI_IO_START, CFG_PCI_MSTR_IO_SIZE,
2436 CFG_POCMR2_MASK_ATTRIB: (MPC826x only)
2437 Overrides the default PCI memory map in cpu/mpc8260/pci.c if set.
2440 Get DDR timing information from an I2C EEPROM. Common
2441 with pluggable memory modules such as SODIMMs
2444 I2C address of the SPD EEPROM
2447 If SPD EEPROM is on an I2C bus other than the first
2448 one, specify here. Note that the value must resolve
2449 to something your driver can deal with.
2451 - CFG_83XX_DDR_USES_CS0
2452 Only for 83xx systems. If specified, then DDR should
2453 be configured using CS0 and CS1 instead of CS2 and CS3.
2455 - CFG_83XX_DDR_USES_CS0
2456 Only for 83xx systems. If specified, then DDR should
2457 be configured using CS0 and CS1 instead of CS2 and CS3.
2459 - CONFIG_ETHER_ON_FEC[12]
2460 Define to enable FEC[12] on a 8xx series processor.
2462 - CONFIG_FEC[12]_PHY
2463 Define to the hardcoded PHY address which corresponds
2464 to the given FEC; i. e.
2465 #define CONFIG_FEC1_PHY 4
2466 means that the PHY with address 4 is connected to FEC1
2468 When set to -1, means to probe for first available.
2470 - CONFIG_FEC[12]_PHY_NORXERR
2471 The PHY does not have a RXERR line (RMII only).
2472 (so program the FEC to ignore it).
2475 Enable RMII mode for all FECs.
2476 Note that this is a global option, we can't
2477 have one FEC in standard MII mode and another in RMII mode.
2479 - CONFIG_CRC32_VERIFY
2480 Add a verify option to the crc32 command.
2483 => crc32 -v <address> <count> <crc32>
2485 Where address/count indicate a memory area
2486 and crc32 is the correct crc32 which the
2490 Add the "loopw" memory command. This only takes effect if
2491 the memory commands are activated globally (CONFIG_CMD_MEM).
2494 Add the "mdc" and "mwc" memory commands. These are cyclic
2499 This command will print 4 bytes (10,11,12,13) each 500 ms.
2501 => mwc.l 100 12345678 10
2502 This command will write 12345678 to address 100 all 10 ms.
2504 This only takes effect if the memory commands are activated
2505 globally (CONFIG_CMD_MEM).
2507 - CONFIG_SKIP_LOWLEVEL_INIT
2508 - CONFIG_SKIP_RELOCATE_UBOOT
2510 [ARM only] If these variables are defined, then
2511 certain low level initializations (like setting up
2512 the memory controller) are omitted and/or U-Boot does
2513 not relocate itself into RAM.
2514 Normally these variables MUST NOT be defined. The
2515 only exception is when U-Boot is loaded (to RAM) by
2516 some other boot loader or by a debugger which
2517 performs these intializations itself.
2520 Building the Software:
2521 ======================
2523 Building U-Boot has been tested in several native build environments
2524 and in many different cross environments. Of course we cannot support
2525 all possibly existing versions of cross development tools in all
2526 (potentially obsolete) versions. In case of tool chain problems we
2527 recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK)
2528 which is extensively used to build and test U-Boot.
2530 If you are not using a native environment, it is assumed that you
2531 have GNU cross compiling tools available in your path. In this case,
2532 you must set the environment variable CROSS_COMPILE in your shell.
2533 Note that no changes to the Makefile or any other source files are
2534 necessary. For example using the ELDK on a 4xx CPU, please enter:
2536 $ CROSS_COMPILE=ppc_4xx-
2537 $ export CROSS_COMPILE
2539 U-Boot is intended to be simple to build. After installing the
2540 sources you must configure U-Boot for one specific board type. This
2545 where "NAME_config" is the name of one of the existing configu-
2546 rations; see the main Makefile for supported names.
2548 Note: for some board special configuration names may exist; check if
2549 additional information is available from the board vendor; for
2550 instance, the TQM823L systems are available without (standard)
2551 or with LCD support. You can select such additional "features"
2552 when chosing the configuration, i. e.
2555 - will configure for a plain TQM823L, i. e. no LCD support
2557 make TQM823L_LCD_config
2558 - will configure for a TQM823L with U-Boot console on LCD
2563 Finally, type "make all", and you should get some working U-Boot
2564 images ready for download to / installation on your system:
2566 - "u-boot.bin" is a raw binary image
2567 - "u-boot" is an image in ELF binary format
2568 - "u-boot.srec" is in Motorola S-Record format
2570 By default the build is performed locally and the objects are saved
2571 in the source directory. One of the two methods can be used to change
2572 this behavior and build U-Boot to some external directory:
2574 1. Add O= to the make command line invocations:
2576 make O=/tmp/build distclean
2577 make O=/tmp/build NAME_config
2578 make O=/tmp/build all
2580 2. Set environment variable BUILD_DIR to point to the desired location:
2582 export BUILD_DIR=/tmp/build
2587 Note that the command line "O=" setting overrides the BUILD_DIR environment
2591 Please be aware that the Makefiles assume you are using GNU make, so
2592 for instance on NetBSD you might need to use "gmake" instead of
2596 If the system board that you have is not listed, then you will need
2597 to port U-Boot to your hardware platform. To do this, follow these
2600 1. Add a new configuration option for your board to the toplevel
2601 "Makefile" and to the "MAKEALL" script, using the existing
2602 entries as examples. Note that here and at many other places
2603 boards and other names are listed in alphabetical sort order. Please
2605 2. Create a new directory to hold your board specific code. Add any
2606 files you need. In your board directory, you will need at least
2607 the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds".
2608 3. Create a new configuration file "include/configs/<board>.h" for
2610 3. If you're porting U-Boot to a new CPU, then also create a new
2611 directory to hold your CPU specific code. Add any files you need.
2612 4. Run "make <board>_config" with your new name.
2613 5. Type "make", and you should get a working "u-boot.srec" file
2614 to be installed on your target system.
2615 6. Debug and solve any problems that might arise.
2616 [Of course, this last step is much harder than it sounds.]
2619 Testing of U-Boot Modifications, Ports to New Hardware, etc.:
2620 ==============================================================
2622 If you have modified U-Boot sources (for instance added a new board
2623 or support for new devices, a new CPU, etc.) you are expected to
2624 provide feedback to the other developers. The feedback normally takes
2625 the form of a "patch", i. e. a context diff against a certain (latest
2626 official or latest in the git repository) version of U-Boot sources.
2628 But before you submit such a patch, please verify that your modifi-
2629 cation did not break existing code. At least make sure that *ALL* of
2630 the supported boards compile WITHOUT ANY compiler warnings. To do so,
2631 just run the "MAKEALL" script, which will configure and build U-Boot
2632 for ALL supported system. Be warned, this will take a while. You can
2633 select which (cross) compiler to use by passing a `CROSS_COMPILE'
2634 environment variable to the script, i. e. to use the ELDK cross tools
2637 CROSS_COMPILE=ppc_8xx- MAKEALL
2639 or to build on a native PowerPC system you can type
2641 CROSS_COMPILE=' ' MAKEALL
2643 When using the MAKEALL script, the default behaviour is to build
2644 U-Boot in the source directory. This location can be changed by
2645 setting the BUILD_DIR environment variable. Also, for each target
2646 built, the MAKEALL script saves two log files (<target>.ERR and
2647 <target>.MAKEALL) in the <source dir>/LOG directory. This default
2648 location can be changed by setting the MAKEALL_LOGDIR environment
2649 variable. For example:
2651 export BUILD_DIR=/tmp/build
2652 export MAKEALL_LOGDIR=/tmp/log
2653 CROSS_COMPILE=ppc_8xx- MAKEALL
2655 With the above settings build objects are saved in the /tmp/build,
2656 log files are saved in the /tmp/log and the source tree remains clean
2657 during the whole build process.
2660 See also "U-Boot Porting Guide" below.
2663 Monitor Commands - Overview:
2664 ============================
2666 go - start application at address 'addr'
2667 run - run commands in an environment variable
2668 bootm - boot application image from memory
2669 bootp - boot image via network using BootP/TFTP protocol
2670 tftpboot- boot image via network using TFTP protocol
2671 and env variables "ipaddr" and "serverip"
2672 (and eventually "gatewayip")
2673 rarpboot- boot image via network using RARP/TFTP protocol
2674 diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
2675 loads - load S-Record file over serial line
2676 loadb - load binary file over serial line (kermit mode)
2678 mm - memory modify (auto-incrementing)
2679 nm - memory modify (constant address)
2680 mw - memory write (fill)
2682 cmp - memory compare
2683 crc32 - checksum calculation
2684 imd - i2c memory display
2685 imm - i2c memory modify (auto-incrementing)
2686 inm - i2c memory modify (constant address)
2687 imw - i2c memory write (fill)
2688 icrc32 - i2c checksum calculation
2689 iprobe - probe to discover valid I2C chip addresses
2690 iloop - infinite loop on address range
2691 isdram - print SDRAM configuration information
2692 sspi - SPI utility commands
2693 base - print or set address offset
2694 printenv- print environment variables
2695 setenv - set environment variables
2696 saveenv - save environment variables to persistent storage
2697 protect - enable or disable FLASH write protection
2698 erase - erase FLASH memory
2699 flinfo - print FLASH memory information
2700 bdinfo - print Board Info structure
2701 iminfo - print header information for application image
2702 coninfo - print console devices and informations
2703 ide - IDE sub-system
2704 loop - infinite loop on address range
2705 loopw - infinite write loop on address range
2706 mtest - simple RAM test
2707 icache - enable or disable instruction cache
2708 dcache - enable or disable data cache
2709 reset - Perform RESET of the CPU
2710 echo - echo args to console
2711 version - print monitor version
2712 help - print online help
2713 ? - alias for 'help'
2716 Monitor Commands - Detailed Description:
2717 ========================================
2721 For now: just type "help <command>".
2724 Environment Variables:
2725 ======================
2727 U-Boot supports user configuration using Environment Variables which
2728 can be made persistent by saving to Flash memory.
2730 Environment Variables are set using "setenv", printed using
2731 "printenv", and saved to Flash using "saveenv". Using "setenv"
2732 without a value can be used to delete a variable from the
2733 environment. As long as you don't save the environment you are
2734 working with an in-memory copy. In case the Flash area containing the
2735 environment is erased by accident, a default environment is provided.
2737 Some configuration options can be set using Environment Variables:
2739 baudrate - see CONFIG_BAUDRATE
2741 bootdelay - see CONFIG_BOOTDELAY
2743 bootcmd - see CONFIG_BOOTCOMMAND
2745 bootargs - Boot arguments when booting an RTOS image
2747 bootfile - Name of the image to load with TFTP
2749 autoload - if set to "no" (any string beginning with 'n'),
2750 "bootp" will just load perform a lookup of the
2751 configuration from the BOOTP server, but not try to
2752 load any image using TFTP
2754 autoscript - if set to "yes" commands like "loadb", "loady",
2755 "bootp", "tftpb", "rarpboot" and "nfs" will attempt
2756 to automatically run script images (by internally
2757 calling "autoscript").
2759 autoscript_uname - if script image is in a format (FIT) this
2760 variable is used to get script subimage unit name.
2762 autostart - if set to "yes", an image loaded using the "bootp",
2763 "rarpboot", "tftpboot" or "diskboot" commands will
2764 be automatically started (by internally calling
2767 If set to "no", a standalone image passed to the
2768 "bootm" command will be copied to the load address
2769 (and eventually uncompressed), but NOT be started.
2770 This can be used to load and uncompress arbitrary
2773 i2cfast - (PPC405GP|PPC405EP only)
2774 if set to 'y' configures Linux I2C driver for fast
2775 mode (400kHZ). This environment variable is used in
2776 initialization code. So, for changes to be effective
2777 it must be saved and board must be reset.
2779 initrd_high - restrict positioning of initrd images:
2780 If this variable is not set, initrd images will be
2781 copied to the highest possible address in RAM; this
2782 is usually what you want since it allows for
2783 maximum initrd size. If for some reason you want to
2784 make sure that the initrd image is loaded below the
2785 CFG_BOOTMAPSZ limit, you can set this environment
2786 variable to a value of "no" or "off" or "0".
2787 Alternatively, you can set it to a maximum upper
2788 address to use (U-Boot will still check that it
2789 does not overwrite the U-Boot stack and data).
2791 For instance, when you have a system with 16 MB
2792 RAM, and want to reserve 4 MB from use by Linux,
2793 you can do this by adding "mem=12M" to the value of
2794 the "bootargs" variable. However, now you must make
2795 sure that the initrd image is placed in the first
2796 12 MB as well - this can be done with
2798 setenv initrd_high 00c00000
2800 If you set initrd_high to 0xFFFFFFFF, this is an
2801 indication to U-Boot that all addresses are legal
2802 for the Linux kernel, including addresses in flash
2803 memory. In this case U-Boot will NOT COPY the
2804 ramdisk at all. This may be useful to reduce the
2805 boot time on your system, but requires that this
2806 feature is supported by your Linux kernel.
2808 ipaddr - IP address; needed for tftpboot command
2810 loadaddr - Default load address for commands like "bootp",
2811 "rarpboot", "tftpboot", "loadb" or "diskboot"
2813 loads_echo - see CONFIG_LOADS_ECHO
2815 serverip - TFTP server IP address; needed for tftpboot command
2817 bootretry - see CONFIG_BOOT_RETRY_TIME
2819 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
2821 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
2823 ethprime - When CONFIG_NET_MULTI is enabled controls which
2824 interface is used first.
2826 ethact - When CONFIG_NET_MULTI is enabled controls which
2827 interface is currently active. For example you
2828 can do the following
2830 => setenv ethact FEC ETHERNET
2831 => ping 192.168.0.1 # traffic sent on FEC ETHERNET
2832 => setenv ethact SCC ETHERNET
2833 => ping 10.0.0.1 # traffic sent on SCC ETHERNET
2835 ethrotate - When set to "no" U-Boot does not go through all
2836 available network interfaces.
2837 It just stays at the currently selected interface.
2839 netretry - When set to "no" each network operation will
2840 either succeed or fail without retrying.
2841 When set to "once" the network operation will
2842 fail when all the available network interfaces
2843 are tried once without success.
2844 Useful on scripts which control the retry operation
2847 npe_ucode - see CONFIG_IXP4XX_NPE_EXT_UCOD
2848 if set load address for the npe microcode
2850 tftpsrcport - If this is set, the value is used for TFTP's
2853 tftpdstport - If this is set, the value is used for TFTP's UDP
2854 destination port instead of the Well Know Port 69.
2856 vlan - When set to a value < 4095 the traffic over
2857 ethernet is encapsulated/received over 802.1q
2860 The following environment variables may be used and automatically
2861 updated by the network boot commands ("bootp" and "rarpboot"),
2862 depending the information provided by your boot server:
2864 bootfile - see above
2865 dnsip - IP address of your Domain Name Server
2866 dnsip2 - IP address of your secondary Domain Name Server
2867 gatewayip - IP address of the Gateway (Router) to use
2868 hostname - Target hostname
2870 netmask - Subnet Mask
2871 rootpath - Pathname of the root filesystem on the NFS server
2872 serverip - see above
2875 There are two special Environment Variables:
2877 serial# - contains hardware identification information such
2878 as type string and/or serial number
2879 ethaddr - Ethernet address
2881 These variables can be set only once (usually during manufacturing of
2882 the board). U-Boot refuses to delete or overwrite these variables
2883 once they have been set once.
2886 Further special Environment Variables:
2888 ver - Contains the U-Boot version string as printed
2889 with the "version" command. This variable is
2890 readonly (see CONFIG_VERSION_VARIABLE).
2893 Please note that changes to some configuration parameters may take
2894 only effect after the next boot (yes, that's just like Windoze :-).
2897 Command Line Parsing:
2898 =====================
2900 There are two different command line parsers available with U-Boot:
2901 the old "simple" one, and the much more powerful "hush" shell:
2903 Old, simple command line parser:
2904 --------------------------------
2906 - supports environment variables (through setenv / saveenv commands)
2907 - several commands on one line, separated by ';'
2908 - variable substitution using "... ${name} ..." syntax
2909 - special characters ('$', ';') can be escaped by prefixing with '\',
2911 setenv bootcmd bootm \${address}
2912 - You can also escape text by enclosing in single apostrophes, for example:
2913 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
2918 - similar to Bourne shell, with control structures like
2919 if...then...else...fi, for...do...done; while...do...done,
2920 until...do...done, ...
2921 - supports environment ("global") variables (through setenv / saveenv
2922 commands) and local shell variables (through standard shell syntax
2923 "name=value"); only environment variables can be used with "run"
2929 (1) If a command line (or an environment variable executed by a "run"
2930 command) contains several commands separated by semicolon, and
2931 one of these commands fails, then the remaining commands will be
2934 (2) If you execute several variables with one call to run (i. e.
2935 calling run with a list af variables as arguments), any failing
2936 command will cause "run" to terminate, i. e. the remaining
2937 variables are not executed.
2939 Note for Redundant Ethernet Interfaces:
2940 =======================================
2942 Some boards come with redundant ethernet interfaces; U-Boot supports
2943 such configurations and is capable of automatic selection of a
2944 "working" interface when needed. MAC assignment works as follows:
2946 Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
2947 MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
2948 "eth1addr" (=>eth1), "eth2addr", ...
2950 If the network interface stores some valid MAC address (for instance
2951 in SROM), this is used as default address if there is NO correspon-
2952 ding setting in the environment; if the corresponding environment
2953 variable is set, this overrides the settings in the card; that means:
2955 o If the SROM has a valid MAC address, and there is no address in the
2956 environment, the SROM's address is used.
2958 o If there is no valid address in the SROM, and a definition in the
2959 environment exists, then the value from the environment variable is
2962 o If both the SROM and the environment contain a MAC address, and
2963 both addresses are the same, this MAC address is used.
2965 o If both the SROM and the environment contain a MAC address, and the
2966 addresses differ, the value from the environment is used and a
2969 o If neither SROM nor the environment contain a MAC address, an error
2976 U-Boot is capable of booting (and performing other auxiliary operations on)
2977 images in two formats:
2979 New uImage format (FIT)
2980 -----------------------
2982 Flexible and powerful format based on Flattened Image Tree -- FIT (similar
2983 to Flattened Device Tree). It allows the use of images with multiple
2984 components (several kernels, ramdisks, etc.), with contents protected by
2985 SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory.
2991 Old image format is based on binary files which can be basically anything,
2992 preceded by a special header; see the definitions in include/image.h for
2993 details; basically, the header defines the following image properties:
2995 * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
2996 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
2997 LynxOS, pSOS, QNX, RTEMS, ARTOS;
2998 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, ARTOS, LynxOS).
2999 * Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86,
3000 IA64, MIPS, NIOS, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
3001 Currently supported: ARM, AVR32, Intel x86, MIPS, NIOS, PowerPC).
3002 * Compression Type (uncompressed, gzip, bzip2)
3008 The header is marked by a special Magic Number, and both the header
3009 and the data portions of the image are secured against corruption by
3016 Although U-Boot should support any OS or standalone application
3017 easily, the main focus has always been on Linux during the design of
3020 U-Boot includes many features that so far have been part of some
3021 special "boot loader" code within the Linux kernel. Also, any
3022 "initrd" images to be used are no longer part of one big Linux image;
3023 instead, kernel and "initrd" are separate images. This implementation
3024 serves several purposes:
3026 - the same features can be used for other OS or standalone
3027 applications (for instance: using compressed images to reduce the
3028 Flash memory footprint)
3030 - it becomes much easier to port new Linux kernel versions because
3031 lots of low-level, hardware dependent stuff are done by U-Boot
3033 - the same Linux kernel image can now be used with different "initrd"
3034 images; of course this also means that different kernel images can
3035 be run with the same "initrd". This makes testing easier (you don't
3036 have to build a new "zImage.initrd" Linux image when you just
3037 change a file in your "initrd"). Also, a field-upgrade of the
3038 software is easier now.
3044 Porting Linux to U-Boot based systems:
3045 ---------------------------------------
3047 U-Boot cannot save you from doing all the necessary modifications to
3048 configure the Linux device drivers for use with your target hardware
3049 (no, we don't intend to provide a full virtual machine interface to
3052 But now you can ignore ALL boot loader code (in arch/ppc/mbxboot).
3054 Just make sure your machine specific header file (for instance
3055 include/asm-ppc/tqm8xx.h) includes the same definition of the Board
3056 Information structure as we define in include/u-boot.h, and make
3057 sure that your definition of IMAP_ADDR uses the same value as your
3058 U-Boot configuration in CFG_IMMR.
3061 Configuring the Linux kernel:
3062 -----------------------------
3064 No specific requirements for U-Boot. Make sure you have some root
3065 device (initial ramdisk, NFS) for your target system.
3068 Building a Linux Image:
3069 -----------------------
3071 With U-Boot, "normal" build targets like "zImage" or "bzImage" are
3072 not used. If you use recent kernel source, a new build target
3073 "uImage" will exist which automatically builds an image usable by
3074 U-Boot. Most older kernels also have support for a "pImage" target,
3075 which was introduced for our predecessor project PPCBoot and uses a
3076 100% compatible format.
3085 The "uImage" build target uses a special tool (in 'tools/mkimage') to
3086 encapsulate a compressed Linux kernel image with header information,
3087 CRC32 checksum etc. for use with U-Boot. This is what we are doing:
3089 * build a standard "vmlinux" kernel image (in ELF binary format):
3091 * convert the kernel into a raw binary image:
3093 ${CROSS_COMPILE}-objcopy -O binary \
3094 -R .note -R .comment \
3095 -S vmlinux linux.bin
3097 * compress the binary image:
3101 * package compressed binary image for U-Boot:
3103 mkimage -A ppc -O linux -T kernel -C gzip \
3104 -a 0 -e 0 -n "Linux Kernel Image" \
3105 -d linux.bin.gz uImage
3108 The "mkimage" tool can also be used to create ramdisk images for use
3109 with U-Boot, either separated from the Linux kernel image, or
3110 combined into one file. "mkimage" encapsulates the images with a 64
3111 byte header containing information about target architecture,
3112 operating system, image type, compression method, entry points, time
3113 stamp, CRC32 checksums, etc.
3115 "mkimage" can be called in two ways: to verify existing images and
3116 print the header information, or to build new images.
3118 In the first form (with "-l" option) mkimage lists the information
3119 contained in the header of an existing U-Boot image; this includes
3120 checksum verification:
3122 tools/mkimage -l image
3123 -l ==> list image header information
3125 The second form (with "-d" option) is used to build a U-Boot image
3126 from a "data file" which is used as image payload:
3128 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
3129 -n name -d data_file image
3130 -A ==> set architecture to 'arch'
3131 -O ==> set operating system to 'os'
3132 -T ==> set image type to 'type'
3133 -C ==> set compression type 'comp'
3134 -a ==> set load address to 'addr' (hex)
3135 -e ==> set entry point to 'ep' (hex)
3136 -n ==> set image name to 'name'
3137 -d ==> use image data from 'datafile'
3139 Right now, all Linux kernels for PowerPC systems use the same load
3140 address (0x00000000), but the entry point address depends on the
3143 - 2.2.x kernels have the entry point at 0x0000000C,
3144 - 2.3.x and later kernels have the entry point at 0x00000000.
3146 So a typical call to build a U-Boot image would read:
3148 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
3149 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
3150 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux.gz \
3151 > examples/uImage.TQM850L
3152 Image Name: 2.4.4 kernel for TQM850L
3153 Created: Wed Jul 19 02:34:59 2000
3154 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3155 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
3156 Load Address: 0x00000000
3157 Entry Point: 0x00000000
3159 To verify the contents of the image (or check for corruption):
3161 -> tools/mkimage -l examples/uImage.TQM850L
3162 Image Name: 2.4.4 kernel for TQM850L
3163 Created: Wed Jul 19 02:34:59 2000
3164 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3165 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
3166 Load Address: 0x00000000
3167 Entry Point: 0x00000000
3169 NOTE: for embedded systems where boot time is critical you can trade
3170 speed for memory and install an UNCOMPRESSED image instead: this
3171 needs more space in Flash, but boots much faster since it does not
3172 need to be uncompressed:
3174 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux.gz
3175 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
3176 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
3177 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux \
3178 > examples/uImage.TQM850L-uncompressed
3179 Image Name: 2.4.4 kernel for TQM850L
3180 Created: Wed Jul 19 02:34:59 2000
3181 Image Type: PowerPC Linux Kernel Image (uncompressed)
3182 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
3183 Load Address: 0x00000000
3184 Entry Point: 0x00000000
3187 Similar you can build U-Boot images from a 'ramdisk.image.gz' file
3188 when your kernel is intended to use an initial ramdisk:
3190 -> tools/mkimage -n 'Simple Ramdisk Image' \
3191 > -A ppc -O linux -T ramdisk -C gzip \
3192 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
3193 Image Name: Simple Ramdisk Image
3194 Created: Wed Jan 12 14:01:50 2000
3195 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
3196 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
3197 Load Address: 0x00000000
3198 Entry Point: 0x00000000
3201 Installing a Linux Image:
3202 -------------------------
3204 To downloading a U-Boot image over the serial (console) interface,
3205 you must convert the image to S-Record format:
3207 objcopy -I binary -O srec examples/image examples/image.srec
3209 The 'objcopy' does not understand the information in the U-Boot
3210 image header, so the resulting S-Record file will be relative to
3211 address 0x00000000. To load it to a given address, you need to
3212 specify the target address as 'offset' parameter with the 'loads'
3215 Example: install the image to address 0x40100000 (which on the
3216 TQM8xxL is in the first Flash bank):
3218 => erase 40100000 401FFFFF
3224 ## Ready for S-Record download ...
3225 ~>examples/image.srec
3226 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
3228 15989 15990 15991 15992
3229 [file transfer complete]
3231 ## Start Addr = 0x00000000
3234 You can check the success of the download using the 'iminfo' command;
3235 this includes a checksum verification so you can be sure no data
3236 corruption happened:
3240 ## Checking Image at 40100000 ...
3241 Image Name: 2.2.13 for initrd on TQM850L
3242 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3243 Data Size: 335725 Bytes = 327 kB = 0 MB
3244 Load Address: 00000000
3245 Entry Point: 0000000c
3246 Verifying Checksum ... OK
3252 The "bootm" command is used to boot an application that is stored in
3253 memory (RAM or Flash). In case of a Linux kernel image, the contents
3254 of the "bootargs" environment variable is passed to the kernel as
3255 parameters. You can check and modify this variable using the
3256 "printenv" and "setenv" commands:
3259 => printenv bootargs
3260 bootargs=root=/dev/ram
3262 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
3264 => printenv bootargs
3265 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
3268 ## Booting Linux kernel at 40020000 ...
3269 Image Name: 2.2.13 for NFS on TQM850L
3270 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3271 Data Size: 381681 Bytes = 372 kB = 0 MB
3272 Load Address: 00000000
3273 Entry Point: 0000000c
3274 Verifying Checksum ... OK
3275 Uncompressing Kernel Image ... OK
3276 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
3277 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
3278 time_init: decrementer frequency = 187500000/60
3279 Calibrating delay loop... 49.77 BogoMIPS
3280 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
3283 If you want to boot a Linux kernel with initial ram disk, you pass
3284 the memory addresses of both the kernel and the initrd image (PPBCOOT
3285 format!) to the "bootm" command:
3287 => imi 40100000 40200000
3289 ## Checking Image at 40100000 ...
3290 Image Name: 2.2.13 for initrd on TQM850L
3291 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3292 Data Size: 335725 Bytes = 327 kB = 0 MB
3293 Load Address: 00000000
3294 Entry Point: 0000000c
3295 Verifying Checksum ... OK
3297 ## Checking Image at 40200000 ...
3298 Image Name: Simple Ramdisk Image
3299 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
3300 Data Size: 566530 Bytes = 553 kB = 0 MB
3301 Load Address: 00000000
3302 Entry Point: 00000000
3303 Verifying Checksum ... OK
3305 => bootm 40100000 40200000
3306 ## Booting Linux kernel at 40100000 ...
3307 Image Name: 2.2.13 for initrd on TQM850L
3308 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3309 Data Size: 335725 Bytes = 327 kB = 0 MB
3310 Load Address: 00000000
3311 Entry Point: 0000000c
3312 Verifying Checksum ... OK
3313 Uncompressing Kernel Image ... OK
3314 ## Loading RAMDisk Image at 40200000 ...
3315 Image Name: Simple Ramdisk Image
3316 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
3317 Data Size: 566530 Bytes = 553 kB = 0 MB
3318 Load Address: 00000000
3319 Entry Point: 00000000
3320 Verifying Checksum ... OK
3321 Loading Ramdisk ... OK
3322 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
3323 Boot arguments: root=/dev/ram
3324 time_init: decrementer frequency = 187500000/60
3325 Calibrating delay loop... 49.77 BogoMIPS
3327 RAMDISK: Compressed image found at block 0
3328 VFS: Mounted root (ext2 filesystem).
3332 Boot Linux and pass a flat device tree:
3335 First, U-Boot must be compiled with the appropriate defines. See the section
3336 titled "Linux Kernel Interface" above for a more in depth explanation. The
3337 following is an example of how to start a kernel and pass an updated
3343 oft=oftrees/mpc8540ads.dtb
3344 => tftp $oftaddr $oft
3345 Speed: 1000, full duplex
3347 TFTP from server 192.168.1.1; our IP address is 192.168.1.101
3348 Filename 'oftrees/mpc8540ads.dtb'.
3349 Load address: 0x300000
3352 Bytes transferred = 4106 (100a hex)
3353 => tftp $loadaddr $bootfile
3354 Speed: 1000, full duplex
3356 TFTP from server 192.168.1.1; our IP address is 192.168.1.2
3358 Load address: 0x200000
3359 Loading:############
3361 Bytes transferred = 1029407 (fb51f hex)
3366 => bootm $loadaddr - $oftaddr
3367 ## Booting image at 00200000 ...
3368 Image Name: Linux-2.6.17-dirty
3369 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3370 Data Size: 1029343 Bytes = 1005.2 kB
3371 Load Address: 00000000
3372 Entry Point: 00000000
3373 Verifying Checksum ... OK
3374 Uncompressing Kernel Image ... OK
3375 Booting using flat device tree at 0x300000
3376 Using MPC85xx ADS machine description
3377 Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb
3381 More About U-Boot Image Types:
3382 ------------------------------
3384 U-Boot supports the following image types:
3386 "Standalone Programs" are directly runnable in the environment
3387 provided by U-Boot; it is expected that (if they behave
3388 well) you can continue to work in U-Boot after return from
3389 the Standalone Program.
3390 "OS Kernel Images" are usually images of some Embedded OS which
3391 will take over control completely. Usually these programs
3392 will install their own set of exception handlers, device
3393 drivers, set up the MMU, etc. - this means, that you cannot
3394 expect to re-enter U-Boot except by resetting the CPU.
3395 "RAMDisk Images" are more or less just data blocks, and their
3396 parameters (address, size) are passed to an OS kernel that is
3398 "Multi-File Images" contain several images, typically an OS
3399 (Linux) kernel image and one or more data images like
3400 RAMDisks. This construct is useful for instance when you want
3401 to boot over the network using BOOTP etc., where the boot
3402 server provides just a single image file, but you want to get
3403 for instance an OS kernel and a RAMDisk image.
3405 "Multi-File Images" start with a list of image sizes, each
3406 image size (in bytes) specified by an "uint32_t" in network
3407 byte order. This list is terminated by an "(uint32_t)0".
3408 Immediately after the terminating 0 follow the images, one by
3409 one, all aligned on "uint32_t" boundaries (size rounded up to
3410 a multiple of 4 bytes).
3412 "Firmware Images" are binary images containing firmware (like
3413 U-Boot or FPGA images) which usually will be programmed to
3416 "Script files" are command sequences that will be executed by
3417 U-Boot's command interpreter; this feature is especially
3418 useful when you configure U-Boot to use a real shell (hush)
3419 as command interpreter.
3425 One of the features of U-Boot is that you can dynamically load and
3426 run "standalone" applications, which can use some resources of
3427 U-Boot like console I/O functions or interrupt services.
3429 Two simple examples are included with the sources:
3434 'examples/hello_world.c' contains a small "Hello World" Demo
3435 application; it is automatically compiled when you build U-Boot.
3436 It's configured to run at address 0x00040004, so you can play with it
3440 ## Ready for S-Record download ...
3441 ~>examples/hello_world.srec
3442 1 2 3 4 5 6 7 8 9 10 11 ...
3443 [file transfer complete]
3445 ## Start Addr = 0x00040004
3447 => go 40004 Hello World! This is a test.
3448 ## Starting application at 0x00040004 ...
3459 Hit any key to exit ...
3461 ## Application terminated, rc = 0x0
3463 Another example, which demonstrates how to register a CPM interrupt
3464 handler with the U-Boot code, can be found in 'examples/timer.c'.
3465 Here, a CPM timer is set up to generate an interrupt every second.
3466 The interrupt service routine is trivial, just printing a '.'
3467 character, but this is just a demo program. The application can be
3468 controlled by the following keys:
3470 ? - print current values og the CPM Timer registers
3471 b - enable interrupts and start timer
3472 e - stop timer and disable interrupts
3473 q - quit application
3476 ## Ready for S-Record download ...
3477 ~>examples/timer.srec
3478 1 2 3 4 5 6 7 8 9 10 11 ...
3479 [file transfer complete]
3481 ## Start Addr = 0x00040004
3484 ## Starting application at 0x00040004 ...
3487 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
3490 [q, b, e, ?] Set interval 1000000 us
3493 [q, b, e, ?] ........
3494 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
3497 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
3500 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
3503 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
3505 [q, b, e, ?] ...Stopping timer
3507 [q, b, e, ?] ## Application terminated, rc = 0x0
3513 Over time, many people have reported problems when trying to use the
3514 "minicom" terminal emulation program for serial download. I (wd)
3515 consider minicom to be broken, and recommend not to use it. Under
3516 Unix, I recommend to use C-Kermit for general purpose use (and
3517 especially for kermit binary protocol download ("loadb" command), and
3518 use "cu" for S-Record download ("loads" command).
3520 Nevertheless, if you absolutely want to use it try adding this
3521 configuration to your "File transfer protocols" section:
3523 Name Program Name U/D FullScr IO-Red. Multi
3524 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
3525 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
3531 Starting at version 0.9.2, U-Boot supports NetBSD both as host
3532 (build U-Boot) and target system (boots NetBSD/mpc8xx).
3534 Building requires a cross environment; it is known to work on
3535 NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
3536 need gmake since the Makefiles are not compatible with BSD make).
3537 Note that the cross-powerpc package does not install include files;
3538 attempting to build U-Boot will fail because <machine/ansi.h> is
3539 missing. This file has to be installed and patched manually:
3541 # cd /usr/pkg/cross/powerpc-netbsd/include
3543 # ln -s powerpc machine
3544 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
3545 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
3547 Native builds *don't* work due to incompatibilities between native
3548 and U-Boot include files.
3550 Booting assumes that (the first part of) the image booted is a
3551 stage-2 loader which in turn loads and then invokes the kernel
3552 proper. Loader sources will eventually appear in the NetBSD source
3553 tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
3554 meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz
3557 Implementation Internals:
3558 =========================
3560 The following is not intended to be a complete description of every
3561 implementation detail. However, it should help to understand the
3562 inner workings of U-Boot and make it easier to port it to custom
3566 Initial Stack, Global Data:
3567 ---------------------------
3569 The implementation of U-Boot is complicated by the fact that U-Boot
3570 starts running out of ROM (flash memory), usually without access to
3571 system RAM (because the memory controller is not initialized yet).
3572 This means that we don't have writable Data or BSS segments, and BSS
3573 is not initialized as zero. To be able to get a C environment working
3574 at all, we have to allocate at least a minimal stack. Implementation
3575 options for this are defined and restricted by the CPU used: Some CPU
3576 models provide on-chip memory (like the IMMR area on MPC8xx and
3577 MPC826x processors), on others (parts of) the data cache can be
3578 locked as (mis-) used as memory, etc.
3580 Chris Hallinan posted a good summary of these issues to the
3581 u-boot-users mailing list:
3583 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
3584 From: "Chris Hallinan" <clh@net1plus.com>
3585 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
3588 Correct me if I'm wrong, folks, but the way I understand it
3589 is this: Using DCACHE as initial RAM for Stack, etc, does not
3590 require any physical RAM backing up the cache. The cleverness
3591 is that the cache is being used as a temporary supply of
3592 necessary storage before the SDRAM controller is setup. It's
3593 beyond the scope of this list to expain the details, but you
3594 can see how this works by studying the cache architecture and
3595 operation in the architecture and processor-specific manuals.
3597 OCM is On Chip Memory, which I believe the 405GP has 4K. It
3598 is another option for the system designer to use as an
3599 initial stack/ram area prior to SDRAM being available. Either
3600 option should work for you. Using CS 4 should be fine if your
3601 board designers haven't used it for something that would
3602 cause you grief during the initial boot! It is frequently not
3605 CFG_INIT_RAM_ADDR should be somewhere that won't interfere
3606 with your processor/board/system design. The default value
3607 you will find in any recent u-boot distribution in
3608 walnut.h should work for you. I'd set it to a value larger
3609 than your SDRAM module. If you have a 64MB SDRAM module, set
3610 it above 400_0000. Just make sure your board has no resources
3611 that are supposed to respond to that address! That code in
3612 start.S has been around a while and should work as is when
3613 you get the config right.
3618 It is essential to remember this, since it has some impact on the C
3619 code for the initialization procedures:
3621 * Initialized global data (data segment) is read-only. Do not attempt
3624 * Do not use any unitialized global data (or implicitely initialized
3625 as zero data - BSS segment) at all - this is undefined, initiali-
3626 zation is performed later (when relocating to RAM).
3628 * Stack space is very limited. Avoid big data buffers or things like
3631 Having only the stack as writable memory limits means we cannot use
3632 normal global data to share information beween the code. But it
3633 turned out that the implementation of U-Boot can be greatly
3634 simplified by making a global data structure (gd_t) available to all
3635 functions. We could pass a pointer to this data as argument to _all_
3636 functions, but this would bloat the code. Instead we use a feature of
3637 the GCC compiler (Global Register Variables) to share the data: we
3638 place a pointer (gd) to the global data into a register which we
3639 reserve for this purpose.
3641 When choosing a register for such a purpose we are restricted by the
3642 relevant (E)ABI specifications for the current architecture, and by
3643 GCC's implementation.
3645 For PowerPC, the following registers have specific use:
3647 R2: reserved for system use
3648 R3-R4: parameter passing and return values
3649 R5-R10: parameter passing
3650 R13: small data area pointer
3654 (U-Boot also uses R14 as internal GOT pointer.)
3656 ==> U-Boot will use R2 to hold a pointer to the global data
3658 Note: on PPC, we could use a static initializer (since the
3659 address of the global data structure is known at compile time),
3660 but it turned out that reserving a register results in somewhat
3661 smaller code - although the code savings are not that big (on
3662 average for all boards 752 bytes for the whole U-Boot image,
3663 624 text + 127 data).
3665 On Blackfin, the normal C ABI (except for P5) is followed as documented here:
3666 http://docs.blackfin.uclinux.org/doku.php?id=application_binary_interface
3668 ==> U-Boot will use P5 to hold a pointer to the global data
3670 On ARM, the following registers are used:
3672 R0: function argument word/integer result
3673 R1-R3: function argument word
3675 R10: stack limit (used only if stack checking if enabled)
3676 R11: argument (frame) pointer
3677 R12: temporary workspace
3680 R15: program counter
3682 ==> U-Boot will use R8 to hold a pointer to the global data
3684 NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope,
3685 or current versions of GCC may "optimize" the code too much.
3690 U-Boot runs in system state and uses physical addresses, i.e. the
3691 MMU is not used either for address mapping nor for memory protection.
3693 The available memory is mapped to fixed addresses using the memory
3694 controller. In this process, a contiguous block is formed for each
3695 memory type (Flash, SDRAM, SRAM), even when it consists of several
3696 physical memory banks.
3698 U-Boot is installed in the first 128 kB of the first Flash bank (on
3699 TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
3700 booting and sizing and initializing DRAM, the code relocates itself
3701 to the upper end of DRAM. Immediately below the U-Boot code some
3702 memory is reserved for use by malloc() [see CFG_MALLOC_LEN
3703 configuration setting]. Below that, a structure with global Board
3704 Info data is placed, followed by the stack (growing downward).
3706 Additionally, some exception handler code is copied to the low 8 kB
3707 of DRAM (0x00000000 ... 0x00001FFF).
3709 So a typical memory configuration with 16 MB of DRAM could look like
3712 0x0000 0000 Exception Vector code
3715 0x0000 2000 Free for Application Use
3721 0x00FB FF20 Monitor Stack (Growing downward)
3722 0x00FB FFAC Board Info Data and permanent copy of global data
3723 0x00FC 0000 Malloc Arena
3726 0x00FE 0000 RAM Copy of Monitor Code
3727 ... eventually: LCD or video framebuffer
3728 ... eventually: pRAM (Protected RAM - unchanged by reset)
3729 0x00FF FFFF [End of RAM]
3732 System Initialization:
3733 ----------------------
3735 In the reset configuration, U-Boot starts at the reset entry point
3736 (on most PowerPC systens at address 0x00000100). Because of the reset
3737 configuration for CS0# this is a mirror of the onboard Flash memory.
3738 To be able to re-map memory U-Boot then jumps to its link address.
3739 To be able to implement the initialization code in C, a (small!)
3740 initial stack is set up in the internal Dual Ported RAM (in case CPUs
3741 which provide such a feature like MPC8xx or MPC8260), or in a locked
3742 part of the data cache. After that, U-Boot initializes the CPU core,
3743 the caches and the SIU.
3745 Next, all (potentially) available memory banks are mapped using a
3746 preliminary mapping. For example, we put them on 512 MB boundaries
3747 (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
3748 on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
3749 programmed for SDRAM access. Using the temporary configuration, a
3750 simple memory test is run that determines the size of the SDRAM
3753 When there is more than one SDRAM bank, and the banks are of
3754 different size, the largest is mapped first. For equal size, the first
3755 bank (CS2#) is mapped first. The first mapping is always for address
3756 0x00000000, with any additional banks following immediately to create
3757 contiguous memory starting from 0.
3759 Then, the monitor installs itself at the upper end of the SDRAM area
3760 and allocates memory for use by malloc() and for the global Board
3761 Info data; also, the exception vector code is copied to the low RAM
3762 pages, and the final stack is set up.
3764 Only after this relocation will you have a "normal" C environment;
3765 until that you are restricted in several ways, mostly because you are
3766 running from ROM, and because the code will have to be relocated to a
3770 U-Boot Porting Guide:
3771 ----------------------
3773 [Based on messages by Jerry Van Baren in the U-Boot-Users mailing
3777 int main (int argc, char *argv[])
3779 sighandler_t no_more_time;
3781 signal (SIGALRM, no_more_time);
3782 alarm (PROJECT_DEADLINE - toSec (3 * WEEK));
3784 if (available_money > available_manpower) {
3785 pay consultant to port U-Boot;
3789 Download latest U-Boot source;
3791 Subscribe to u-boot-users mailing list;
3794 email ("Hi, I am new to U-Boot, how do I get started?");
3798 Read the README file in the top level directory;
3799 Read http://www.denx.de/twiki/bin/view/DULG/Manual ;
3800 Read the source, Luke;
3803 if (available_money > toLocalCurrency ($2500)) {
3806 Add a lot of aggravation and time;
3809 Create your own board support subdirectory;
3811 Create your own board config file;
3815 Add / modify source code;
3819 email ("Hi, I am having problems...");
3821 Send patch file to Wolfgang;
3826 void no_more_time (int sig)
3835 All contributions to U-Boot should conform to the Linux kernel
3836 coding style; see the file "Documentation/CodingStyle" and the script
3837 "scripts/Lindent" in your Linux kernel source directory. In sources
3838 originating from U-Boot a style corresponding to "Lindent -pcs" (adding
3839 spaces before parameters to function calls) is actually used.
3841 Source files originating from a different project (for example the
3842 MTD subsystem) are generally exempt from these guidelines and are not
3843 reformated to ease subsequent migration to newer versions of those
3846 Please note that U-Boot is implemented in C (and to some small parts in
3847 Assembler); no C++ is used, so please do not use C++ style comments (//)
3850 Please also stick to the following formatting rules:
3851 - remove any trailing white space
3852 - use TAB characters for indentation, not spaces
3853 - make sure NOT to use DOS '\r\n' line feeds
3854 - do not add more than 2 empty lines to source files
3855 - do not add trailing empty lines to source files
3857 Submissions which do not conform to the standards may be returned
3858 with a request to reformat the changes.
3864 Since the number of patches for U-Boot is growing, we need to
3865 establish some rules. Submissions which do not conform to these rules
3866 may be rejected, even when they contain important and valuable stuff.
3868 Patches shall be sent to the u-boot-users mailing list.
3870 Please see http://www.denx.de/wiki/UBoot/Patches for details.
3872 When you send a patch, please include the following information with
3875 * For bug fixes: a description of the bug and how your patch fixes
3876 this bug. Please try to include a way of demonstrating that the
3877 patch actually fixes something.
3879 * For new features: a description of the feature and your
3882 * A CHANGELOG entry as plaintext (separate from the patch)
3884 * For major contributions, your entry to the CREDITS file
3886 * When you add support for a new board, don't forget to add this
3887 board to the MAKEALL script, too.
3889 * If your patch adds new configuration options, don't forget to
3890 document these in the README file.
3892 * The patch itself. If you are using git (which is *strongly*
3893 recommended) you can easily generate the patch using the
3894 "git-format-patch". If you then use "git-send-email" to send it to
3895 the U-Boot mailing list, you will avoid most of the common problems
3896 with some other mail clients.
3898 If you cannot use git, use "diff -purN OLD NEW". If your version of
3899 diff does not support these options, then get the latest version of
3902 The current directory when running this command shall be the parent
3903 directory of the U-Boot source tree (i. e. please make sure that
3904 your patch includes sufficient directory information for the
3907 We prefer patches as plain text. MIME attachments are discouraged,
3908 and compressed attachments must not be used.
3910 * If one logical set of modifications affects or creates several
3911 files, all these changes shall be submitted in a SINGLE patch file.
3913 * Changesets that contain different, unrelated modifications shall be
3914 submitted as SEPARATE patches, one patch per changeset.
3919 * Before sending the patch, run the MAKEALL script on your patched
3920 source tree and make sure that no errors or warnings are reported
3921 for any of the boards.
3923 * Keep your modifications to the necessary minimum: A patch
3924 containing several unrelated changes or arbitrary reformats will be
3925 returned with a request to re-formatting / split it.
3927 * If you modify existing code, make sure that your new code does not
3928 add to the memory footprint of the code ;-) Small is beautiful!
3929 When adding new features, these should compile conditionally only
3930 (using #ifdef), and the resulting code with the new feature
3931 disabled must not need more memory than the old code without your
3934 * Remember that there is a size limit of 40 kB per message on the
3935 u-boot-users mailing list. Bigger patches will be moderated. If
3936 they are reasonable and not bigger than 100 kB, they will be
3937 acknowledged. Even bigger patches should be avoided.
projects / u-boot / blob