2 # (C) Copyright 2000 - 2008
3 # Wolfgang Denk, DENX Software Engineering, wd@denx.de.
5 # See file CREDITS for list of people who contributed to this
8 # This program is free software; you can redistribute it and/or
9 # modify it under the terms of the GNU General Public License as
10 # published by the Free Software Foundation; either version 2 of
11 # the License, or (at your option) any later version.
13 # This program is distributed in the hope that it will be useful,
14 # but WITHOUT ANY WARRANTY; without even the implied warranty of
15 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 # GNU General Public License for more details.
18 # You should have received a copy of the GNU General Public License
19 # along with this program; if not, write to the Free Software
20 # Foundation, Inc., 59 Temple Place, Suite 330, Boston,
27 This directory contains the source code for U-Boot, a boot loader for
28 Embedded boards based on PowerPC, ARM, MIPS and several other
29 processors, which can be installed in a boot ROM and used to
30 initialize and test the hardware or to download and run application
33 The development of U-Boot is closely related to Linux: some parts of
34 the source code originate in the Linux source tree, we have some
35 header files in common, and special provision has been made to
36 support booting of Linux images.
38 Some attention has been paid to make this software easily
39 configurable and extendable. For instance, all monitor commands are
40 implemented with the same call interface, so that it's very easy to
41 add new commands. Also, instead of permanently adding rarely used
42 code (for instance hardware test utilities) to the monitor, you can
43 load and run it dynamically.
49 In general, all boards for which a configuration option exists in the
50 Makefile have been tested to some extent and can be considered
51 "working". In fact, many of them are used in production systems.
53 In case of problems see the CHANGELOG and CREDITS files to find out
54 who contributed the specific port. The MAINTAINERS file lists board
61 In case you have questions about, problems with or contributions for
62 U-Boot you should send a message to the U-Boot mailing list at
63 <u-boot-users@lists.sourceforge.net>. There is also an archive of
64 previous traffic on the mailing list - please search the archive
65 before asking FAQ's. Please see
66 http://lists.sourceforge.net/lists/listinfo/u-boot-users/
69 Where to get source code:
70 =========================
72 The U-Boot source code is maintained in the git repository at
73 git://www.denx.de/git/u-boot.git ; you can browse it online at
74 http://www.denx.de/cgi-bin/gitweb.cgi?p=u-boot.git;a=summary
76 The "snapshot" links on this page allow you to download tarballs of
77 any version you might be interested in. Ofifcial releases are also
78 available for FTP download from the ftp://ftp.denx.de/pub/u-boot/
81 Pre-built (and tested) images are available from
82 ftp://ftp.denx.de/pub/u-boot/images/
88 - start from 8xxrom sources
89 - create PPCBoot project (http://sourceforge.net/projects/ppcboot)
91 - make it easier to add custom boards
92 - make it possible to add other [PowerPC] CPUs
93 - extend functions, especially:
94 * Provide extended interface to Linux boot loader
97 * PCMCIA / CompactFLash / ATA disk / SCSI ... boot
98 - create ARMBoot project (http://sourceforge.net/projects/armboot)
99 - add other CPU families (starting with ARM)
100 - create U-Boot project (http://sourceforge.net/projects/u-boot)
101 - current project page: see http://www.denx.de/wiki/UBoot
107 The "official" name of this project is "Das U-Boot". The spelling
108 "U-Boot" shall be used in all written text (documentation, comments
109 in source files etc.). Example:
111 This is the README file for the U-Boot project.
113 File names etc. shall be based on the string "u-boot". Examples:
115 include/asm-ppc/u-boot.h
117 #include <asm/u-boot.h>
119 Variable names, preprocessor constants etc. shall be either based on
120 the string "u_boot" or on "U_BOOT". Example:
122 U_BOOT_VERSION u_boot_logo
123 IH_OS_U_BOOT u_boot_hush_start
129 U-Boot uses a 3 level version number containing a version, a
130 sub-version, and a patchlevel: "U-Boot-2.34.5" means version "2",
131 sub-version "34", and patchlevel "4".
133 The patchlevel is used to indicate certain stages of development
134 between released versions, i. e. officially released versions of
135 U-Boot will always have a patchlevel of "0".
141 - board Board dependent files
142 - common Misc architecture independent functions
143 - cpu CPU specific files
144 - 74xx_7xx Files specific to Freescale MPC74xx and 7xx CPUs
145 - arm720t Files specific to ARM 720 CPUs
146 - arm920t Files specific to ARM 920 CPUs
147 - at91rm9200 Files specific to Atmel AT91RM9200 CPU
148 - imx Files specific to Freescale MC9328 i.MX CPUs
149 - s3c24x0 Files specific to Samsung S3C24X0 CPUs
150 - arm925t Files specific to ARM 925 CPUs
151 - arm926ejs Files specific to ARM 926 CPUs
152 - arm1136 Files specific to ARM 1136 CPUs
153 - at32ap Files specific to Atmel AVR32 AP CPUs
154 - i386 Files specific to i386 CPUs
155 - ixp Files specific to Intel XScale IXP CPUs
156 - mcf52x2 Files specific to Freescale ColdFire MCF52x2 CPUs
157 - mcf5227x Files specific to Freescale ColdFire MCF5227x CPUs
158 - mcf532x Files specific to Freescale ColdFire MCF5329 CPUs
159 - mcf5445x Files specific to Freescale ColdFire MCF5445x CPUs
160 - mcf547x_8x Files specific to Freescale ColdFire MCF547x_8x CPUs
161 - mips Files specific to MIPS CPUs
162 - mpc5xx Files specific to Freescale MPC5xx CPUs
163 - mpc5xxx Files specific to Freescale MPC5xxx CPUs
164 - mpc8xx Files specific to Freescale MPC8xx CPUs
165 - mpc8220 Files specific to Freescale MPC8220 CPUs
166 - mpc824x Files specific to Freescale MPC824x CPUs
167 - mpc8260 Files specific to Freescale MPC8260 CPUs
168 - mpc85xx Files specific to Freescale MPC85xx CPUs
169 - nios Files specific to Altera NIOS CPUs
170 - nios2 Files specific to Altera Nios-II CPUs
171 - ppc4xx Files specific to AMCC PowerPC 4xx CPUs
172 - pxa Files specific to Intel XScale PXA CPUs
173 - s3c44b0 Files specific to Samsung S3C44B0 CPUs
174 - sa1100 Files specific to Intel StrongARM SA1100 CPUs
175 - disk Code for disk drive partition handling
176 - doc Documentation (don't expect too much)
177 - drivers Commonly used device drivers
178 - dtt Digital Thermometer and Thermostat drivers
179 - examples Example code for standalone applications, etc.
180 - include Header Files
181 - lib_arm Files generic to ARM architecture
182 - lib_avr32 Files generic to AVR32 architecture
183 - lib_generic Files generic to all architectures
184 - lib_i386 Files generic to i386 architecture
185 - lib_m68k Files generic to m68k architecture
186 - lib_mips Files generic to MIPS architecture
187 - lib_nios Files generic to NIOS architecture
188 - lib_ppc Files generic to PowerPC architecture
189 - libfdt Library files to support flattened device trees
190 - net Networking code
191 - post Power On Self Test
192 - rtc Real Time Clock drivers
193 - tools Tools to build S-Record or U-Boot images, etc.
195 Software Configuration:
196 =======================
198 Configuration is usually done using C preprocessor defines; the
199 rationale behind that is to avoid dead code whenever possible.
201 There are two classes of configuration variables:
203 * Configuration _OPTIONS_:
204 These are selectable by the user and have names beginning with
207 * Configuration _SETTINGS_:
208 These depend on the hardware etc. and should not be meddled with if
209 you don't know what you're doing; they have names beginning with
212 Later we will add a configuration tool - probably similar to or even
213 identical to what's used for the Linux kernel. Right now, we have to
214 do the configuration by hand, which means creating some symbolic
215 links and editing some configuration files. We use the TQM8xxL boards
219 Selection of Processor Architecture and Board Type:
220 ---------------------------------------------------
222 For all supported boards there are ready-to-use default
223 configurations available; just type "make <board_name>_config".
225 Example: For a TQM823L module type:
230 For the Cogent platform, you need to specify the cpu type as well;
231 e.g. "make cogent_mpc8xx_config". And also configure the cogent
232 directory according to the instructions in cogent/README.
235 Configuration Options:
236 ----------------------
238 Configuration depends on the combination of board and CPU type; all
239 such information is kept in a configuration file
240 "include/configs/<board_name>.h".
242 Example: For a TQM823L module, all configuration settings are in
243 "include/configs/TQM823L.h".
246 Many of the options are named exactly as the corresponding Linux
247 kernel configuration options. The intention is to make it easier to
248 build a config tool - later.
251 The following options need to be configured:
253 - CPU Type: Define exactly one, e.g. CONFIG_MPC85XX.
255 - Board Type: Define exactly one, e.g. CONFIG_MPC8540ADS.
257 - CPU Daughterboard Type: (if CONFIG_ATSTK1000 is defined)
258 Define exactly one, e.g. CONFIG_ATSTK1002
260 - CPU Module Type: (if CONFIG_COGENT is defined)
261 Define exactly one of
263 --- FIXME --- not tested yet:
264 CONFIG_CMA286_60, CONFIG_CMA286_21, CONFIG_CMA286_60P,
265 CONFIG_CMA287_23, CONFIG_CMA287_50
267 - Motherboard Type: (if CONFIG_COGENT is defined)
268 Define exactly one of
269 CONFIG_CMA101, CONFIG_CMA102
271 - Motherboard I/O Modules: (if CONFIG_COGENT is defined)
272 Define one or more of
275 - Motherboard Options: (if CONFIG_CMA101 or CONFIG_CMA102 are defined)
276 Define one or more of
277 CONFIG_LCD_HEARTBEAT - update a character position on
278 the lcd display every second with
281 - Board flavour: (if CONFIG_MPC8260ADS is defined)
284 CFG_8260ADS - original MPC8260ADS
285 CFG_8266ADS - MPC8266ADS
286 CFG_PQ2FADS - PQ2FADS-ZU or PQ2FADS-VR
287 CFG_8272ADS - MPC8272ADS
289 - MPC824X Family Member (if CONFIG_MPC824X is defined)
290 Define exactly one of
291 CONFIG_MPC8240, CONFIG_MPC8245
293 - 8xx CPU Options: (if using an MPC8xx cpu)
294 CONFIG_8xx_GCLK_FREQ - deprecated: CPU clock if
295 get_gclk_freq() cannot work
296 e.g. if there is no 32KHz
297 reference PIT/RTC clock
298 CONFIG_8xx_OSCLK - PLL input clock (either EXTCLK
301 - 859/866/885 CPU options: (if using a MPC859 or MPC866 or MPC885 CPU):
304 CONFIG_8xx_CPUCLK_DEFAULT
305 See doc/README.MPC866
309 Define this to measure the actual CPU clock instead
310 of relying on the correctness of the configured
311 values. Mostly useful for board bringup to make sure
312 the PLL is locked at the intended frequency. Note
313 that this requires a (stable) reference clock (32 kHz
314 RTC clock or CFG_8XX_XIN)
316 - Intel Monahans options:
317 CFG_MONAHANS_RUN_MODE_OSC_RATIO
319 Defines the Monahans run mode to oscillator
320 ratio. Valid values are 8, 16, 24, 31. The core
321 frequency is this value multiplied by 13 MHz.
323 CFG_MONAHANS_TURBO_RUN_MODE_RATIO
325 Defines the Monahans turbo mode to oscillator
326 ratio. Valid values are 1 (default if undefined) and
327 2. The core frequency as calculated above is multiplied
330 - Linux Kernel Interface:
333 U-Boot stores all clock information in Hz
334 internally. For binary compatibility with older Linux
335 kernels (which expect the clocks passed in the
336 bd_info data to be in MHz) the environment variable
337 "clocks_in_mhz" can be defined so that U-Boot
338 converts clock data to MHZ before passing it to the
340 When CONFIG_CLOCKS_IN_MHZ is defined, a definition of
341 "clocks_in_mhz=1" is automatically included in the
344 CONFIG_MEMSIZE_IN_BYTES [relevant for MIPS only]
346 When transfering memsize parameter to linux, some versions
347 expect it to be in bytes, others in MB.
348 Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes.
350 CONFIG_OF_LIBFDT / CONFIG_OF_FLAT_TREE
352 New kernel versions are expecting firmware settings to be
353 passed using flattened device trees (based on open firmware
357 * New libfdt-based support
358 * Adds the "fdt" command
359 * The bootm command automatically updates the fdt
362 * Deprecated, see CONFIG_OF_LIBFDT
363 * Original ft_build.c-based support
364 * Automatically modifies the dft as part of the bootm command
365 * The environment variable "disable_of", when set,
366 disables this functionality.
368 OF_CPU - The proper name of the cpus node.
369 OF_SOC - The proper name of the soc node.
370 OF_TBCLK - The timebase frequency.
371 OF_STDOUT_PATH - The path to the console device
373 boards with QUICC Engines require OF_QE to set UCC mac addresses
377 * CONFIG_OF_LIBFDT - enables the "fdt bd_t" command
378 * CONFIG_OF_FLAT_TREE - The resulting flat device tree
379 will have a copy of the bd_t. Space should be
380 pre-allocated in the dts for the bd_t.
382 CONFIG_OF_HAS_UBOOT_ENV
384 * CONFIG_OF_LIBFDT - enables the "fdt env" command
385 * CONFIG_OF_FLAT_TREE - The resulting flat device tree
386 will have a copy of u-boot's environment variables
388 CONFIG_OF_BOARD_SETUP
390 Board code has addition modification that it wants to make
391 to the flat device tree before handing it off to the kernel
395 This define fills in the correct boot cpu in the boot
396 param header, the default value is zero if undefined.
401 Define this if you want support for Amba PrimeCell PL010 UARTs.
405 Define this if you want support for Amba PrimeCell PL011 UARTs.
409 If you have Amba PrimeCell PL011 UARTs, set this variable to
410 the clock speed of the UARTs.
414 If you have Amba PrimeCell PL010 or PL011 UARTs on your board,
415 define this to a list of base addresses for each (supported)
416 port. See e.g. include/configs/versatile.h
420 Depending on board, define exactly one serial port
421 (like CONFIG_8xx_CONS_SMC1, CONFIG_8xx_CONS_SMC2,
422 CONFIG_8xx_CONS_SCC1, ...), or switch off the serial
423 console by defining CONFIG_8xx_CONS_NONE
425 Note: if CONFIG_8xx_CONS_NONE is defined, the serial
426 port routines must be defined elsewhere
427 (i.e. serial_init(), serial_getc(), ...)
430 Enables console device for a color framebuffer. Needs following
431 defines (cf. smiLynxEM, i8042, board/eltec/bab7xx)
432 VIDEO_FB_LITTLE_ENDIAN graphic memory organisation
434 VIDEO_HW_RECTFILL graphic chip supports
437 VIDEO_HW_BITBLT graphic chip supports
438 bit-blit (cf. smiLynxEM)
439 VIDEO_VISIBLE_COLS visible pixel columns
441 VIDEO_VISIBLE_ROWS visible pixel rows
442 VIDEO_PIXEL_SIZE bytes per pixel
443 VIDEO_DATA_FORMAT graphic data format
444 (0-5, cf. cfb_console.c)
445 VIDEO_FB_ADRS framebuffer address
446 VIDEO_KBD_INIT_FCT keyboard int fct
447 (i.e. i8042_kbd_init())
448 VIDEO_TSTC_FCT test char fct
450 VIDEO_GETC_FCT get char fct
452 CONFIG_CONSOLE_CURSOR cursor drawing on/off
453 (requires blink timer
455 CFG_CONSOLE_BLINK_COUNT blink interval (cf. i8042.c)
456 CONFIG_CONSOLE_TIME display time/date info in
458 (requires CONFIG_CMD_DATE)
459 CONFIG_VIDEO_LOGO display Linux logo in
461 CONFIG_VIDEO_BMP_LOGO use bmp_logo.h instead of
462 linux_logo.h for logo.
463 Requires CONFIG_VIDEO_LOGO
464 CONFIG_CONSOLE_EXTRA_INFO
465 addional board info beside
468 When CONFIG_CFB_CONSOLE is defined, video console is
469 default i/o. Serial console can be forced with
470 environment 'console=serial'.
472 When CONFIG_SILENT_CONSOLE is defined, all console
473 messages (by U-Boot and Linux!) can be silenced with
474 the "silent" environment variable. See
475 doc/README.silent for more information.
478 CONFIG_BAUDRATE - in bps
479 Select one of the baudrates listed in
480 CFG_BAUDRATE_TABLE, see below.
481 CFG_BRGCLK_PRESCALE, baudrate prescale
483 - Interrupt driven serial port input:
484 CONFIG_SERIAL_SOFTWARE_FIFO
487 Use an interrupt handler for receiving data on the
488 serial port. It also enables using hardware handshake
489 (RTS/CTS) and UART's built-in FIFO. Set the number of
490 bytes the interrupt driven input buffer should have.
492 Leave undefined to disable this feature, including
493 disable the buffer and hardware handshake.
495 - Console UART Number:
499 If defined internal UART1 (and not UART0) is used
500 as default U-Boot console.
502 - Boot Delay: CONFIG_BOOTDELAY - in seconds
503 Delay before automatically booting the default image;
504 set to -1 to disable autoboot.
506 See doc/README.autoboot for these options that
507 work with CONFIG_BOOTDELAY. None are required.
508 CONFIG_BOOT_RETRY_TIME
509 CONFIG_BOOT_RETRY_MIN
510 CONFIG_AUTOBOOT_KEYED
511 CONFIG_AUTOBOOT_PROMPT
512 CONFIG_AUTOBOOT_DELAY_STR
513 CONFIG_AUTOBOOT_STOP_STR
514 CONFIG_AUTOBOOT_DELAY_STR2
515 CONFIG_AUTOBOOT_STOP_STR2
516 CONFIG_ZERO_BOOTDELAY_CHECK
517 CONFIG_RESET_TO_RETRY
521 Only needed when CONFIG_BOOTDELAY is enabled;
522 define a command string that is automatically executed
523 when no character is read on the console interface
524 within "Boot Delay" after reset.
527 This can be used to pass arguments to the bootm
528 command. The value of CONFIG_BOOTARGS goes into the
529 environment value "bootargs".
531 CONFIG_RAMBOOT and CONFIG_NFSBOOT
532 The value of these goes into the environment as
533 "ramboot" and "nfsboot" respectively, and can be used
534 as a convenience, when switching between booting from
540 When this option is #defined, the existence of the
541 environment variable "preboot" will be checked
542 immediately before starting the CONFIG_BOOTDELAY
543 countdown and/or running the auto-boot command resp.
544 entering interactive mode.
546 This feature is especially useful when "preboot" is
547 automatically generated or modified. For an example
548 see the LWMON board specific code: here "preboot" is
549 modified when the user holds down a certain
550 combination of keys on the (special) keyboard when
553 - Serial Download Echo Mode:
555 If defined to 1, all characters received during a
556 serial download (using the "loads" command) are
557 echoed back. This might be needed by some terminal
558 emulations (like "cu"), but may as well just take
559 time on others. This setting #define's the initial
560 value of the "loads_echo" environment variable.
562 - Kgdb Serial Baudrate: (if CONFIG_CMD_KGDB is defined)
564 Select one of the baudrates listed in
565 CFG_BAUDRATE_TABLE, see below.
568 Monitor commands can be included or excluded
569 from the build by using the #include files
570 "config_cmd_all.h" and #undef'ing unwanted
571 commands, or using "config_cmd_default.h"
572 and augmenting with additional #define's
575 The default command configuration includes all commands
576 except those marked below with a "*".
578 CONFIG_CMD_ASKENV * ask for env variable
579 CONFIG_CMD_AUTOSCRIPT Autoscript Support
580 CONFIG_CMD_BDI bdinfo
581 CONFIG_CMD_BEDBUG * Include BedBug Debugger
582 CONFIG_CMD_BMP * BMP support
583 CONFIG_CMD_BSP * Board specific commands
584 CONFIG_CMD_BOOTD bootd
585 CONFIG_CMD_CACHE * icache, dcache
586 CONFIG_CMD_CONSOLE coninfo
587 CONFIG_CMD_DATE * support for RTC, date/time...
588 CONFIG_CMD_DHCP * DHCP support
589 CONFIG_CMD_DIAG * Diagnostics
590 CONFIG_CMD_DOC * Disk-On-Chip Support
591 CONFIG_CMD_DTT * Digital Therm and Thermostat
592 CONFIG_CMD_ECHO echo arguments
593 CONFIG_CMD_EEPROM * EEPROM read/write support
594 CONFIG_CMD_ELF * bootelf, bootvx
595 CONFIG_CMD_ENV saveenv
596 CONFIG_CMD_FDC * Floppy Disk Support
597 CONFIG_CMD_FAT * FAT partition support
598 CONFIG_CMD_FDOS * Dos diskette Support
599 CONFIG_CMD_FLASH flinfo, erase, protect
600 CONFIG_CMD_FPGA FPGA device initialization support
601 CONFIG_CMD_HWFLOW * RTS/CTS hw flow control
602 CONFIG_CMD_I2C * I2C serial bus support
603 CONFIG_CMD_IDE * IDE harddisk support
604 CONFIG_CMD_IMI iminfo
605 CONFIG_CMD_IMLS List all found images
606 CONFIG_CMD_IMMAP * IMMR dump support
607 CONFIG_CMD_IRQ * irqinfo
608 CONFIG_CMD_ITEST Integer/string test of 2 values
609 CONFIG_CMD_JFFS2 * JFFS2 Support
610 CONFIG_CMD_KGDB * kgdb
611 CONFIG_CMD_LOADB loadb
612 CONFIG_CMD_LOADS loads
613 CONFIG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base,
615 CONFIG_CMD_MISC Misc functions like sleep etc
616 CONFIG_CMD_MMC * MMC memory mapped support
617 CONFIG_CMD_MII * MII utility commands
618 CONFIG_CMD_NAND * NAND support
619 CONFIG_CMD_NET bootp, tftpboot, rarpboot
620 CONFIG_CMD_PCI * pciinfo
621 CONFIG_CMD_PCMCIA * PCMCIA support
622 CONFIG_CMD_PING * send ICMP ECHO_REQUEST to network
624 CONFIG_CMD_PORTIO * Port I/O
625 CONFIG_CMD_REGINFO * Register dump
626 CONFIG_CMD_RUN run command in env variable
627 CONFIG_CMD_SAVES * save S record dump
628 CONFIG_CMD_SCSI * SCSI Support
629 CONFIG_CMD_SDRAM * print SDRAM configuration information
630 (requires CONFIG_CMD_I2C)
631 CONFIG_CMD_SETGETDCR Support for DCR Register access
633 CONFIG_CMD_SPI * SPI serial bus support
634 CONFIG_CMD_USB * USB support
635 CONFIG_CMD_VFD * VFD support (TRAB)
636 CONFIG_CMD_BSP * Board SPecific functions
637 CONFIG_CMD_CDP * Cisco Discover Protocol support
638 CONFIG_CMD_FSL * Microblaze FSL support
641 EXAMPLE: If you want all functions except of network
642 support you can write:
644 #include "config_cmd_all.h"
645 #undef CONFIG_CMD_NET
648 fdt (flattened device tree) command: CONFIG_OF_LIBFDT
650 Note: Don't enable the "icache" and "dcache" commands
651 (configuration option CONFIG_CMD_CACHE) unless you know
652 what you (and your U-Boot users) are doing. Data
653 cache cannot be enabled on systems like the 8xx or
654 8260 (where accesses to the IMMR region must be
655 uncached), and it cannot be disabled on all other
656 systems where we (mis-) use the data cache to hold an
657 initial stack and some data.
660 XXX - this list needs to get updated!
664 If this variable is defined, it enables watchdog
665 support. There must be support in the platform specific
666 code for a watchdog. For the 8xx and 8260 CPUs, the
667 SIU Watchdog feature is enabled in the SYPCR
671 CONFIG_VERSION_VARIABLE
672 If this variable is defined, an environment variable
673 named "ver" is created by U-Boot showing the U-Boot
674 version as printed by the "version" command.
675 This variable is readonly.
679 When CONFIG_CMD_DATE is selected, the type of the RTC
680 has to be selected, too. Define exactly one of the
683 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx
684 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC
685 CONFIG_RTC_MC146818 - use MC146818 RTC
686 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC
687 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC
688 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC
689 CONFIG_RTC_DS164x - use Dallas DS164x RTC
690 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC
691 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC
692 CFG_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337
694 Note that if the RTC uses I2C, then the I2C interface
695 must also be configured. See I2C Support, below.
699 When CONFIG_TIMESTAMP is selected, the timestamp
700 (date and time) of an image is printed by image
701 commands like bootm or iminfo. This option is
702 automatically enabled when you select CONFIG_CMD_DATE .
705 CONFIG_MAC_PARTITION and/or CONFIG_DOS_PARTITION
706 and/or CONFIG_ISO_PARTITION
708 If IDE or SCSI support is enabled (CONFIG_CMD_IDE or
709 CONFIG_CMD_SCSI) you must configure support for at
710 least one partition type as well.
713 CONFIG_IDE_RESET_ROUTINE - this is defined in several
714 board configurations files but used nowhere!
716 CONFIG_IDE_RESET - is this is defined, IDE Reset will
717 be performed by calling the function
718 ide_set_reset(int reset)
719 which has to be defined in a board specific file
724 Set this to enable ATAPI support.
729 Set this to enable support for disks larger than 137GB
730 Also look at CFG_64BIT_LBA ,CFG_64BIT_VSPRINTF and CFG_64BIT_STRTOUL
731 Whithout these , LBA48 support uses 32bit variables and will 'only'
732 support disks up to 2.1TB.
735 When enabled, makes the IDE subsystem use 64bit sector addresses.
739 At the moment only there is only support for the
740 SYM53C8XX SCSI controller; define
741 CONFIG_SCSI_SYM53C8XX to enable it.
743 CFG_SCSI_MAX_LUN [8], CFG_SCSI_MAX_SCSI_ID [7] and
744 CFG_SCSI_MAX_DEVICE [CFG_SCSI_MAX_SCSI_ID *
745 CFG_SCSI_MAX_LUN] can be adjusted to define the
746 maximum numbers of LUNs, SCSI ID's and target
748 CFG_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz)
750 - NETWORK Support (PCI):
752 Support for Intel 8254x gigabit chips.
755 Support for Intel 82557/82559/82559ER chips.
756 Optional CONFIG_EEPRO100_SROM_WRITE enables eeprom
757 write routine for first time initialisation.
760 Support for Digital 2114x chips.
761 Optional CONFIG_TULIP_SELECT_MEDIA for board specific
762 modem chip initialisation (KS8761/QS6611).
765 Support for National dp83815 chips.
768 Support for National dp8382[01] gigabit chips.
770 - NETWORK Support (other):
772 CONFIG_DRIVER_LAN91C96
773 Support for SMSC's LAN91C96 chips.
776 Define this to hold the physical address
777 of the LAN91C96's I/O space
779 CONFIG_LAN91C96_USE_32_BIT
780 Define this to enable 32 bit addressing
782 CONFIG_DRIVER_SMC91111
783 Support for SMSC's LAN91C111 chip
786 Define this to hold the physical address
787 of the device (I/O space)
789 CONFIG_SMC_USE_32_BIT
790 Define this if data bus is 32 bits
792 CONFIG_SMC_USE_IOFUNCS
793 Define this to use i/o functions instead of macros
794 (some hardware wont work with macros)
797 At the moment only the UHCI host controller is
798 supported (PIP405, MIP405, MPC5200); define
799 CONFIG_USB_UHCI to enable it.
800 define CONFIG_USB_KEYBOARD to enable the USB Keyboard
801 and define CONFIG_USB_STORAGE to enable the USB
804 Supported are USB Keyboards and USB Floppy drives
806 MPC5200 USB requires additional defines:
808 for 528 MHz Clock: 0x0001bbbb
810 for differential drivers: 0x00001000
811 for single ended drivers: 0x00005000
813 May be defined to allow interrupt polling
814 instead of using asynchronous interrupts
817 Define the below if you wish to use the USB console.
818 Once firmware is rebuilt from a serial console issue the
819 command "setenv stdin usbtty; setenv stdout usbtty" and
820 attach your usb cable. The Unix command "dmesg" should print
821 it has found a new device. The environment variable usbtty
822 can be set to gserial or cdc_acm to enable your device to
823 appear to a USB host as a Linux gserial device or a
824 Common Device Class Abstract Control Model serial device.
825 If you select usbtty = gserial you should be able to enumerate
827 # modprobe usbserial vendor=0xVendorID product=0xProductID
828 else if using cdc_acm, simply setting the environment
829 variable usbtty to be cdc_acm should suffice. The following
830 might be defined in YourBoardName.h
833 Define this to build a UDC device
836 Define this to have a tty type of device available to
837 talk to the UDC device
839 CFG_CONSOLE_IS_IN_ENV
840 Define this if you want stdin, stdout &/or stderr to
844 CFG_USB_EXTC_CLK 0xBLAH
845 Derive USB clock from external clock "blah"
846 - CFG_USB_EXTC_CLK 0x02
848 CFG_USB_BRG_CLK 0xBLAH
849 Derive USB clock from brgclk
850 - CFG_USB_BRG_CLK 0x04
852 If you have a USB-IF assigned VendorID then you may wish to
853 define your own vendor specific values either in BoardName.h
854 or directly in usbd_vendor_info.h. If you don't define
855 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME,
856 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot
857 should pretend to be a Linux device to it's target host.
859 CONFIG_USBD_MANUFACTURER
860 Define this string as the name of your company for
861 - CONFIG_USBD_MANUFACTURER "my company"
863 CONFIG_USBD_PRODUCT_NAME
864 Define this string as the name of your product
865 - CONFIG_USBD_PRODUCT_NAME "acme usb device"
868 Define this as your assigned Vendor ID from the USB
869 Implementors Forum. This *must* be a genuine Vendor ID
870 to avoid polluting the USB namespace.
871 - CONFIG_USBD_VENDORID 0xFFFF
873 CONFIG_USBD_PRODUCTID
874 Define this as the unique Product ID
876 - CONFIG_USBD_PRODUCTID 0xFFFF
880 The MMC controller on the Intel PXA is supported. To
881 enable this define CONFIG_MMC. The MMC can be
882 accessed from the boot prompt by mapping the device
883 to physical memory similar to flash. Command line is
884 enabled with CONFIG_CMD_MMC. The MMC driver also works with
885 the FAT fs. This is enabled with CONFIG_CMD_FAT.
887 - Journaling Flash filesystem support:
888 CONFIG_JFFS2_NAND, CONFIG_JFFS2_NAND_OFF, CONFIG_JFFS2_NAND_SIZE,
889 CONFIG_JFFS2_NAND_DEV
890 Define these for a default partition on a NAND device
892 CFG_JFFS2_FIRST_SECTOR,
893 CFG_JFFS2_FIRST_BANK, CFG_JFFS2_NUM_BANKS
894 Define these for a default partition on a NOR device
897 Define this to create an own partition. You have to provide a
898 function struct part_info* jffs2_part_info(int part_num)
900 If you define only one JFFS2 partition you may also want to
901 #define CFG_JFFS_SINGLE_PART 1
902 to disable the command chpart. This is the default when you
903 have not defined a custom partition
908 Define this to enable standard (PC-Style) keyboard
912 Standard PC keyboard driver with US (is default) and
913 GERMAN key layout (switch via environment 'keymap=de') support.
914 Export function i8042_kbd_init, i8042_tstc and i8042_getc
915 for cfb_console. Supports cursor blinking.
920 Define this to enable video support (for output to
925 Enable Chips & Technologies 69000 Video chip
927 CONFIG_VIDEO_SMI_LYNXEM
928 Enable Silicon Motion SMI 712/710/810 Video chip. The
929 video output is selected via environment 'videoout'
930 (1 = LCD and 2 = CRT). If videoout is undefined, CRT is
933 For the CT69000 and SMI_LYNXEM drivers, videomode is
934 selected via environment 'videomode'. Two diferent ways
936 - "videomode=num" 'num' is a standard LiLo mode numbers.
937 Following standard modes are supported (* is default):
939 Colors 640x480 800x600 1024x768 1152x864 1280x1024
940 -------------+---------------------------------------------
941 8 bits | 0x301* 0x303 0x305 0x161 0x307
942 15 bits | 0x310 0x313 0x316 0x162 0x319
943 16 bits | 0x311 0x314 0x317 0x163 0x31A
944 24 bits | 0x312 0x315 0x318 ? 0x31B
945 -------------+---------------------------------------------
946 (i.e. setenv videomode 317; saveenv; reset;)
948 - "videomode=bootargs" all the video parameters are parsed
949 from the bootargs. (See drivers/video/videomodes.c)
952 CONFIG_VIDEO_SED13806
953 Enable Epson SED13806 driver. This driver supports 8bpp
954 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP
955 or CONFIG_VIDEO_SED13806_16BPP
960 Define this to enable a custom keyboard support.
961 This simply calls drv_keyboard_init() which must be
962 defined in your board-specific files.
963 The only board using this so far is RBC823.
965 - LCD Support: CONFIG_LCD
967 Define this to enable LCD support (for output to LCD
968 display); also select one of the supported displays
969 by defining one of these:
971 CONFIG_NEC_NL6448AC33:
973 NEC NL6448AC33-18. Active, color, single scan.
975 CONFIG_NEC_NL6448BC20
977 NEC NL6448BC20-08. 6.5", 640x480.
978 Active, color, single scan.
980 CONFIG_NEC_NL6448BC33_54
982 NEC NL6448BC33-54. 10.4", 640x480.
983 Active, color, single scan.
987 Sharp 320x240. Active, color, single scan.
988 It isn't 16x9, and I am not sure what it is.
990 CONFIG_SHARP_LQ64D341
992 Sharp LQ64D341 display, 640x480.
993 Active, color, single scan.
997 HLD1045 display, 640x480.
998 Active, color, single scan.
1002 Optrex CBL50840-2 NF-FW 99 22 M5
1004 Hitachi LMG6912RPFC-00T
1008 320x240. Black & white.
1010 Normally display is black on white background; define
1011 CFG_WHITE_ON_BLACK to get it inverted.
1013 - Splash Screen Support: CONFIG_SPLASH_SCREEN
1015 If this option is set, the environment is checked for
1016 a variable "splashimage". If found, the usual display
1017 of logo, copyright and system information on the LCD
1018 is suppressed and the BMP image at the address
1019 specified in "splashimage" is loaded instead. The
1020 console is redirected to the "nulldev", too. This
1021 allows for a "silent" boot where a splash screen is
1022 loaded very quickly after power-on.
1024 - Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP
1026 If this option is set, additionally to standard BMP
1027 images, gzipped BMP images can be displayed via the
1028 splashscreen support or the bmp command.
1030 - Compression support:
1033 If this option is set, support for bzip2 compressed
1034 images is included. If not, only uncompressed and gzip
1035 compressed images are supported.
1037 NOTE: the bzip2 algorithm requires a lot of RAM, so
1038 the malloc area (as defined by CFG_MALLOC_LEN) should
1044 The address of PHY on MII bus.
1046 CONFIG_PHY_CLOCK_FREQ (ppc4xx)
1048 The clock frequency of the MII bus
1052 If this option is set, support for speed/duplex
1053 detection of Gigabit PHY is included.
1055 CONFIG_PHY_RESET_DELAY
1057 Some PHY like Intel LXT971A need extra delay after
1058 reset before any MII register access is possible.
1059 For such PHY, set this option to the usec delay
1060 required. (minimum 300usec for LXT971A)
1062 CONFIG_PHY_CMD_DELAY (ppc4xx)
1064 Some PHY like Intel LXT971A need extra delay after
1065 command issued before MII status register can be read
1072 Define a default value for ethernet address to use
1073 for the respective ethernet interface, in case this
1074 is not determined automatically.
1079 Define a default value for the IP address to use for
1080 the default ethernet interface, in case this is not
1081 determined through e.g. bootp.
1083 - Server IP address:
1086 Defines a default value for theIP address of a TFTP
1087 server to contact when using the "tftboot" command.
1089 - Multicast TFTP Mode:
1092 Defines whether you want to support multicast TFTP as per
1093 rfc-2090; for example to work with atftp. Lets lots of targets
1094 tftp down the same boot image concurrently. Note: the ethernet
1095 driver in use must provide a function: mcast() to join/leave a
1098 CONFIG_BOOTP_RANDOM_DELAY
1099 - BOOTP Recovery Mode:
1100 CONFIG_BOOTP_RANDOM_DELAY
1102 If you have many targets in a network that try to
1103 boot using BOOTP, you may want to avoid that all
1104 systems send out BOOTP requests at precisely the same
1105 moment (which would happen for instance at recovery
1106 from a power failure, when all systems will try to
1107 boot, thus flooding the BOOTP server. Defining
1108 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
1109 inserted before sending out BOOTP requests. The
1110 following delays are inserted then:
1112 1st BOOTP request: delay 0 ... 1 sec
1113 2nd BOOTP request: delay 0 ... 2 sec
1114 3rd BOOTP request: delay 0 ... 4 sec
1116 BOOTP requests: delay 0 ... 8 sec
1118 - DHCP Advanced Options:
1119 You can fine tune the DHCP functionality by defining
1120 CONFIG_BOOTP_* symbols:
1122 CONFIG_BOOTP_SUBNETMASK
1123 CONFIG_BOOTP_GATEWAY
1124 CONFIG_BOOTP_HOSTNAME
1125 CONFIG_BOOTP_NISDOMAIN
1126 CONFIG_BOOTP_BOOTPATH
1127 CONFIG_BOOTP_BOOTFILESIZE
1130 CONFIG_BOOTP_SEND_HOSTNAME
1131 CONFIG_BOOTP_NTPSERVER
1132 CONFIG_BOOTP_TIMEOFFSET
1133 CONFIG_BOOTP_VENDOREX
1135 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip
1136 environment variable, not the BOOTP server.
1138 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS
1139 serverip from a DHCP server, it is possible that more
1140 than one DNS serverip is offered to the client.
1141 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS
1142 serverip will be stored in the additional environment
1143 variable "dnsip2". The first DNS serverip is always
1144 stored in the variable "dnsip", when CONFIG_BOOTP_DNS
1147 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable
1148 to do a dynamic update of a DNS server. To do this, they
1149 need the hostname of the DHCP requester.
1150 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content
1151 of the "hostname" environment variable is passed as
1152 option 12 to the DHCP server.
1154 CONFIG_BOOTP_DHCP_REQUEST_DELAY
1156 A 32bit value in microseconds for a delay between
1157 receiving a "DHCP Offer" and sending the "DHCP Request".
1158 This fixes a problem with certain DHCP servers that don't
1159 respond 100% of the time to a "DHCP request". E.g. On an
1160 AT91RM9200 processor running at 180MHz, this delay needed
1161 to be *at least* 15,000 usec before a Windows Server 2003
1162 DHCP server would reply 100% of the time. I recommend at
1163 least 50,000 usec to be safe. The alternative is to hope
1164 that one of the retries will be successful but note that
1165 the DHCP timeout and retry process takes a longer than
1169 CONFIG_CDP_DEVICE_ID
1171 The device id used in CDP trigger frames.
1173 CONFIG_CDP_DEVICE_ID_PREFIX
1175 A two character string which is prefixed to the MAC address
1180 A printf format string which contains the ascii name of
1181 the port. Normally is set to "eth%d" which sets
1182 eth0 for the first ethernet, eth1 for the second etc.
1184 CONFIG_CDP_CAPABILITIES
1186 A 32bit integer which indicates the device capabilities;
1187 0x00000010 for a normal host which does not forwards.
1191 An ascii string containing the version of the software.
1195 An ascii string containing the name of the platform.
1199 A 32bit integer sent on the trigger.
1201 CONFIG_CDP_POWER_CONSUMPTION
1203 A 16bit integer containing the power consumption of the
1204 device in .1 of milliwatts.
1206 CONFIG_CDP_APPLIANCE_VLAN_TYPE
1208 A byte containing the id of the VLAN.
1210 - Status LED: CONFIG_STATUS_LED
1212 Several configurations allow to display the current
1213 status using a LED. For instance, the LED will blink
1214 fast while running U-Boot code, stop blinking as
1215 soon as a reply to a BOOTP request was received, and
1216 start blinking slow once the Linux kernel is running
1217 (supported by a status LED driver in the Linux
1218 kernel). Defining CONFIG_STATUS_LED enables this
1221 - CAN Support: CONFIG_CAN_DRIVER
1223 Defining CONFIG_CAN_DRIVER enables CAN driver support
1224 on those systems that support this (optional)
1225 feature, like the TQM8xxL modules.
1227 - I2C Support: CONFIG_HARD_I2C | CONFIG_SOFT_I2C
1229 These enable I2C serial bus commands. Defining either of
1230 (but not both of) CONFIG_HARD_I2C or CONFIG_SOFT_I2C will
1231 include the appropriate I2C driver for the selected cpu.
1233 This will allow you to use i2c commands at the u-boot
1234 command line (as long as you set CONFIG_CMD_I2C in
1235 CONFIG_COMMANDS) and communicate with i2c based realtime
1236 clock chips. See common/cmd_i2c.c for a description of the
1237 command line interface.
1239 CONFIG_I2C_CMD_TREE is a recommended option that places
1240 all I2C commands under a single 'i2c' root command. The
1241 older 'imm', 'imd', 'iprobe' etc. commands are considered
1242 deprecated and may disappear in the future.
1244 CONFIG_HARD_I2C selects a hardware I2C controller.
1246 CONFIG_SOFT_I2C configures u-boot to use a software (aka
1247 bit-banging) driver instead of CPM or similar hardware
1250 There are several other quantities that must also be
1251 defined when you define CONFIG_HARD_I2C or CONFIG_SOFT_I2C.
1253 In both cases you will need to define CFG_I2C_SPEED
1254 to be the frequency (in Hz) at which you wish your i2c bus
1255 to run and CFG_I2C_SLAVE to be the address of this node (ie
1256 the cpu's i2c node address).
1258 Now, the u-boot i2c code for the mpc8xx (cpu/mpc8xx/i2c.c)
1259 sets the cpu up as a master node and so its address should
1260 therefore be cleared to 0 (See, eg, MPC823e User's Manual
1261 p.16-473). So, set CFG_I2C_SLAVE to 0.
1263 That's all that's required for CONFIG_HARD_I2C.
1265 If you use the software i2c interface (CONFIG_SOFT_I2C)
1266 then the following macros need to be defined (examples are
1267 from include/configs/lwmon.h):
1271 (Optional). Any commands necessary to enable the I2C
1272 controller or configure ports.
1274 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
1278 (Only for MPC8260 CPU). The I/O port to use (the code
1279 assumes both bits are on the same port). Valid values
1280 are 0..3 for ports A..D.
1284 The code necessary to make the I2C data line active
1285 (driven). If the data line is open collector, this
1288 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
1292 The code necessary to make the I2C data line tri-stated
1293 (inactive). If the data line is open collector, this
1296 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
1300 Code that returns TRUE if the I2C data line is high,
1303 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
1307 If <bit> is TRUE, sets the I2C data line high. If it
1308 is FALSE, it clears it (low).
1310 eg: #define I2C_SDA(bit) \
1311 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
1312 else immr->im_cpm.cp_pbdat &= ~PB_SDA
1316 If <bit> is TRUE, sets the I2C clock line high. If it
1317 is FALSE, it clears it (low).
1319 eg: #define I2C_SCL(bit) \
1320 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
1321 else immr->im_cpm.cp_pbdat &= ~PB_SCL
1325 This delay is invoked four times per clock cycle so this
1326 controls the rate of data transfer. The data rate thus
1327 is 1 / (I2C_DELAY * 4). Often defined to be something
1330 #define I2C_DELAY udelay(2)
1334 When a board is reset during an i2c bus transfer
1335 chips might think that the current transfer is still
1336 in progress. On some boards it is possible to access
1337 the i2c SCLK line directly, either by using the
1338 processor pin as a GPIO or by having a second pin
1339 connected to the bus. If this option is defined a
1340 custom i2c_init_board() routine in boards/xxx/board.c
1341 is run early in the boot sequence.
1343 CONFIG_I2CFAST (PPC405GP|PPC405EP only)
1345 This option enables configuration of bi_iic_fast[] flags
1346 in u-boot bd_info structure based on u-boot environment
1347 variable "i2cfast". (see also i2cfast)
1349 CONFIG_I2C_MULTI_BUS
1351 This option allows the use of multiple I2C buses, each of which
1352 must have a controller. At any point in time, only one bus is
1353 active. To switch to a different bus, use the 'i2c dev' command.
1354 Note that bus numbering is zero-based.
1358 This option specifies a list of I2C devices that will be skipped
1359 when the 'i2c probe' command is issued (or 'iprobe' using the legacy
1360 command). If CONFIG_I2C_MULTI_BUS is set, specify a list of bus-device
1361 pairs. Otherwise, specify a 1D array of device addresses
1364 #undef CONFIG_I2C_MULTI_BUS
1365 #define CFG_I2C_NOPROBES {0x50,0x68}
1367 will skip addresses 0x50 and 0x68 on a board with one I2C bus
1369 #define CONFIG_I2C_MULTI_BUS
1370 #define CFG_I2C_MULTI_NOPROBES {{0,0x50},{0,0x68},{1,0x54}}
1372 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1
1376 If defined, then this indicates the I2C bus number for DDR SPD.
1377 If not defined, then U-Boot assumes that SPD is on I2C bus 0.
1381 If defined, then this indicates the I2C bus number for the RTC.
1382 If not defined, then U-Boot assumes that RTC is on I2C bus 0.
1386 If defined, then this indicates the I2C bus number for the DTT.
1387 If not defined, then U-Boot assumes that DTT is on I2C bus 0.
1391 Define this option if you want to use Freescale's I2C driver in
1392 drivers/i2c/fsl_i2c.c.
1395 - SPI Support: CONFIG_SPI
1397 Enables SPI driver (so far only tested with
1398 SPI EEPROM, also an instance works with Crystal A/D and
1399 D/As on the SACSng board)
1403 Enables extended (16-bit) SPI EEPROM addressing.
1404 (symmetrical to CONFIG_I2C_X)
1408 Enables a software (bit-bang) SPI driver rather than
1409 using hardware support. This is a general purpose
1410 driver that only requires three general I/O port pins
1411 (two outputs, one input) to function. If this is
1412 defined, the board configuration must define several
1413 SPI configuration items (port pins to use, etc). For
1414 an example, see include/configs/sacsng.h.
1418 Enables a hardware SPI driver for general-purpose reads
1419 and writes. As with CONFIG_SOFT_SPI, the board configuration
1420 must define a list of chip-select function pointers.
1421 Currently supported on some MPC8xxx processors. For an
1422 example, see include/configs/mpc8349emds.h.
1424 - FPGA Support: CONFIG_FPGA
1426 Enables FPGA subsystem.
1428 CONFIG_FPGA_<vendor>
1430 Enables support for specific chip vendors.
1433 CONFIG_FPGA_<family>
1435 Enables support for FPGA family.
1436 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX)
1440 Specify the number of FPGA devices to support.
1442 CFG_FPGA_PROG_FEEDBACK
1444 Enable printing of hash marks during FPGA configuration.
1448 Enable checks on FPGA configuration interface busy
1449 status by the configuration function. This option
1450 will require a board or device specific function to
1455 If defined, a function that provides delays in the FPGA
1456 configuration driver.
1458 CFG_FPGA_CHECK_CTRLC
1459 Allow Control-C to interrupt FPGA configuration
1461 CFG_FPGA_CHECK_ERROR
1463 Check for configuration errors during FPGA bitfile
1464 loading. For example, abort during Virtex II
1465 configuration if the INIT_B line goes low (which
1466 indicated a CRC error).
1470 Maximum time to wait for the INIT_B line to deassert
1471 after PROB_B has been deasserted during a Virtex II
1472 FPGA configuration sequence. The default time is 500
1477 Maximum time to wait for BUSY to deassert during
1478 Virtex II FPGA configuration. The default is 5 mS.
1480 CFG_FPGA_WAIT_CONFIG
1482 Time to wait after FPGA configuration. The default is
1485 - Configuration Management:
1488 If defined, this string will be added to the U-Boot
1489 version information (U_BOOT_VERSION)
1491 - Vendor Parameter Protection:
1493 U-Boot considers the values of the environment
1494 variables "serial#" (Board Serial Number) and
1495 "ethaddr" (Ethernet Address) to be parameters that
1496 are set once by the board vendor / manufacturer, and
1497 protects these variables from casual modification by
1498 the user. Once set, these variables are read-only,
1499 and write or delete attempts are rejected. You can
1500 change this behviour:
1502 If CONFIG_ENV_OVERWRITE is #defined in your config
1503 file, the write protection for vendor parameters is
1504 completely disabled. Anybody can change or delete
1507 Alternatively, if you #define _both_ CONFIG_ETHADDR
1508 _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
1509 ethernet address is installed in the environment,
1510 which can be changed exactly ONCE by the user. [The
1511 serial# is unaffected by this, i. e. it remains
1517 Define this variable to enable the reservation of
1518 "protected RAM", i. e. RAM which is not overwritten
1519 by U-Boot. Define CONFIG_PRAM to hold the number of
1520 kB you want to reserve for pRAM. You can overwrite
1521 this default value by defining an environment
1522 variable "pram" to the number of kB you want to
1523 reserve. Note that the board info structure will
1524 still show the full amount of RAM. If pRAM is
1525 reserved, a new environment variable "mem" will
1526 automatically be defined to hold the amount of
1527 remaining RAM in a form that can be passed as boot
1528 argument to Linux, for instance like that:
1530 setenv bootargs ... mem=\${mem}
1533 This way you can tell Linux not to use this memory,
1534 either, which results in a memory region that will
1535 not be affected by reboots.
1537 *WARNING* If your board configuration uses automatic
1538 detection of the RAM size, you must make sure that
1539 this memory test is non-destructive. So far, the
1540 following board configurations are known to be
1543 ETX094, IVMS8, IVML24, SPD8xx, TQM8xxL,
1544 HERMES, IP860, RPXlite, LWMON, LANTEC,
1545 PCU_E, FLAGADM, TQM8260
1550 Define this variable to stop the system in case of a
1551 fatal error, so that you have to reset it manually.
1552 This is probably NOT a good idea for an embedded
1553 system where you want to system to reboot
1554 automatically as fast as possible, but it may be
1555 useful during development since you can try to debug
1556 the conditions that lead to the situation.
1558 CONFIG_NET_RETRY_COUNT
1560 This variable defines the number of retries for
1561 network operations like ARP, RARP, TFTP, or BOOTP
1562 before giving up the operation. If not defined, a
1563 default value of 5 is used.
1565 - Command Interpreter:
1566 CONFIG_AUTO_COMPLETE
1568 Enable auto completion of commands using TAB.
1570 Note that this feature has NOT been implemented yet
1571 for the "hush" shell.
1576 Define this variable to enable the "hush" shell (from
1577 Busybox) as command line interpreter, thus enabling
1578 powerful command line syntax like
1579 if...then...else...fi conditionals or `&&' and '||'
1580 constructs ("shell scripts").
1582 If undefined, you get the old, much simpler behaviour
1583 with a somewhat smaller memory footprint.
1588 This defines the secondary prompt string, which is
1589 printed when the command interpreter needs more input
1590 to complete a command. Usually "> ".
1594 In the current implementation, the local variables
1595 space and global environment variables space are
1596 separated. Local variables are those you define by
1597 simply typing `name=value'. To access a local
1598 variable later on, you have write `$name' or
1599 `${name}'; to execute the contents of a variable
1600 directly type `$name' at the command prompt.
1602 Global environment variables are those you use
1603 setenv/printenv to work with. To run a command stored
1604 in such a variable, you need to use the run command,
1605 and you must not use the '$' sign to access them.
1607 To store commands and special characters in a
1608 variable, please use double quotation marks
1609 surrounding the whole text of the variable, instead
1610 of the backslashes before semicolons and special
1613 - Commandline Editing and History:
1614 CONFIG_CMDLINE_EDITING
1616 Enable editiong and History functions for interactive
1617 commandline input operations
1619 - Default Environment:
1620 CONFIG_EXTRA_ENV_SETTINGS
1622 Define this to contain any number of null terminated
1623 strings (variable = value pairs) that will be part of
1624 the default environment compiled into the boot image.
1626 For example, place something like this in your
1627 board's config file:
1629 #define CONFIG_EXTRA_ENV_SETTINGS \
1633 Warning: This method is based on knowledge about the
1634 internal format how the environment is stored by the
1635 U-Boot code. This is NOT an official, exported
1636 interface! Although it is unlikely that this format
1637 will change soon, there is no guarantee either.
1638 You better know what you are doing here.
1640 Note: overly (ab)use of the default environment is
1641 discouraged. Make sure to check other ways to preset
1642 the environment like the autoscript function or the
1645 - DataFlash Support:
1646 CONFIG_HAS_DATAFLASH
1648 Defining this option enables DataFlash features and
1649 allows to read/write in Dataflash via the standard
1652 - SystemACE Support:
1655 Adding this option adds support for Xilinx SystemACE
1656 chips attached via some sort of local bus. The address
1657 of the chip must alsh be defined in the
1658 CFG_SYSTEMACE_BASE macro. For example:
1660 #define CONFIG_SYSTEMACE
1661 #define CFG_SYSTEMACE_BASE 0xf0000000
1663 When SystemACE support is added, the "ace" device type
1664 becomes available to the fat commands, i.e. fatls.
1666 - TFTP Fixed UDP Port:
1669 If this is defined, the environment variable tftpsrcp
1670 is used to supply the TFTP UDP source port value.
1671 If tftpsrcp isn't defined, the normal pseudo-random port
1672 number generator is used.
1674 Also, the environment variable tftpdstp is used to supply
1675 the TFTP UDP destination port value. If tftpdstp isn't
1676 defined, the normal port 69 is used.
1678 The purpose for tftpsrcp is to allow a TFTP server to
1679 blindly start the TFTP transfer using the pre-configured
1680 target IP address and UDP port. This has the effect of
1681 "punching through" the (Windows XP) firewall, allowing
1682 the remainder of the TFTP transfer to proceed normally.
1683 A better solution is to properly configure the firewall,
1684 but sometimes that is not allowed.
1686 - Show boot progress:
1687 CONFIG_SHOW_BOOT_PROGRESS
1689 Defining this option allows to add some board-
1690 specific code (calling a user-provided function
1691 "show_boot_progress(int)") that enables you to show
1692 the system's boot progress on some display (for
1693 example, some LED's) on your board. At the moment,
1694 the following checkpoints are implemented:
1696 Legacy uImage format:
1699 1 common/cmd_bootm.c before attempting to boot an image
1700 -1 common/cmd_bootm.c Image header has bad magic number
1701 2 common/cmd_bootm.c Image header has correct magic number
1702 -2 common/cmd_bootm.c Image header has bad checksum
1703 3 common/cmd_bootm.c Image header has correct checksum
1704 -3 common/cmd_bootm.c Image data has bad checksum
1705 4 common/cmd_bootm.c Image data has correct checksum
1706 -4 common/cmd_bootm.c Image is for unsupported architecture
1707 5 common/cmd_bootm.c Architecture check OK
1708 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi)
1709 6 common/cmd_bootm.c Image Type check OK
1710 -6 common/cmd_bootm.c gunzip uncompression error
1711 -7 common/cmd_bootm.c Unimplemented compression type
1712 7 common/cmd_bootm.c Uncompression OK
1713 8 common/cmd_bootm.c No uncompress/copy overwrite error
1714 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX)
1716 9 common/image.c Start initial ramdisk verification
1717 -10 common/image.c Ramdisk header has bad magic number
1718 -11 common/image.c Ramdisk header has bad checksum
1719 10 common/image.c Ramdisk header is OK
1720 -12 common/image.c Ramdisk data has bad checksum
1721 11 common/image.c Ramdisk data has correct checksum
1722 12 common/image.c Ramdisk verification complete, start loading
1723 -13 common/image.c Wrong Image Type (not PPC Linux Ramdisk)
1724 13 common/image.c Start multifile image verification
1725 14 common/image.c No initial ramdisk, no multifile, continue.
1727 15 lib_<arch>/bootm.c All preparation done, transferring control to OS
1729 -30 lib_ppc/board.c Fatal error, hang the system
1730 -31 post/post.c POST test failed, detected by post_output_backlog()
1731 -32 post/post.c POST test failed, detected by post_run_single()
1733 34 common/cmd_doc.c before loading a Image from a DOC device
1734 -35 common/cmd_doc.c Bad usage of "doc" command
1735 35 common/cmd_doc.c correct usage of "doc" command
1736 -36 common/cmd_doc.c No boot device
1737 36 common/cmd_doc.c correct boot device
1738 -37 common/cmd_doc.c Unknown Chip ID on boot device
1739 37 common/cmd_doc.c correct chip ID found, device available
1740 -38 common/cmd_doc.c Read Error on boot device
1741 38 common/cmd_doc.c reading Image header from DOC device OK
1742 -39 common/cmd_doc.c Image header has bad magic number
1743 39 common/cmd_doc.c Image header has correct magic number
1744 -40 common/cmd_doc.c Error reading Image from DOC device
1745 40 common/cmd_doc.c Image header has correct magic number
1746 41 common/cmd_ide.c before loading a Image from a IDE device
1747 -42 common/cmd_ide.c Bad usage of "ide" command
1748 42 common/cmd_ide.c correct usage of "ide" command
1749 -43 common/cmd_ide.c No boot device
1750 43 common/cmd_ide.c boot device found
1751 -44 common/cmd_ide.c Device not available
1752 44 common/cmd_ide.c Device available
1753 -45 common/cmd_ide.c wrong partition selected
1754 45 common/cmd_ide.c partition selected
1755 -46 common/cmd_ide.c Unknown partition table
1756 46 common/cmd_ide.c valid partition table found
1757 -47 common/cmd_ide.c Invalid partition type
1758 47 common/cmd_ide.c correct partition type
1759 -48 common/cmd_ide.c Error reading Image Header on boot device
1760 48 common/cmd_ide.c reading Image Header from IDE device OK
1761 -49 common/cmd_ide.c Image header has bad magic number
1762 49 common/cmd_ide.c Image header has correct magic number
1763 -50 common/cmd_ide.c Image header has bad checksum
1764 50 common/cmd_ide.c Image header has correct checksum
1765 -51 common/cmd_ide.c Error reading Image from IDE device
1766 51 common/cmd_ide.c reading Image from IDE device OK
1767 52 common/cmd_nand.c before loading a Image from a NAND device
1768 -53 common/cmd_nand.c Bad usage of "nand" command
1769 53 common/cmd_nand.c correct usage of "nand" command
1770 -54 common/cmd_nand.c No boot device
1771 54 common/cmd_nand.c boot device found
1772 -55 common/cmd_nand.c Unknown Chip ID on boot device
1773 55 common/cmd_nand.c correct chip ID found, device available
1774 -56 common/cmd_nand.c Error reading Image Header on boot device
1775 56 common/cmd_nand.c reading Image Header from NAND device OK
1776 -57 common/cmd_nand.c Image header has bad magic number
1777 57 common/cmd_nand.c Image header has correct magic number
1778 -58 common/cmd_nand.c Error reading Image from NAND device
1779 58 common/cmd_nand.c reading Image from NAND device OK
1781 -60 common/env_common.c Environment has a bad CRC, using default
1783 64 net/eth.c starting with Ethernetconfiguration.
1784 -64 net/eth.c no Ethernet found.
1785 65 net/eth.c Ethernet found.
1787 -80 common/cmd_net.c usage wrong
1788 80 common/cmd_net.c before calling NetLoop()
1789 -81 common/cmd_net.c some error in NetLoop() occured
1790 81 common/cmd_net.c NetLoop() back without error
1791 -82 common/cmd_net.c size == 0 (File with size 0 loaded)
1792 82 common/cmd_net.c trying automatic boot
1793 83 common/cmd_net.c running autoscript
1794 -83 common/cmd_net.c some error in automatic boot or autoscript
1795 84 common/cmd_net.c end without errors
1800 100 common/cmd_bootm.c Kernel FIT Image has correct format
1801 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format
1802 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration
1803 -101 common/cmd_bootm.c Can't get configuration for kernel subimage
1804 102 common/cmd_bootm.c Kernel unit name specified
1805 -103 common/cmd_bootm.c Can't get kernel subimage node offset
1806 103 common/cmd_bootm.c Found configuration node
1807 104 common/cmd_bootm.c Got kernel subimage node offset
1808 -104 common/cmd_bootm.c Kernel subimage hash verification failed
1809 105 common/cmd_bootm.c Kernel subimage hash verification OK
1810 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture
1811 106 common/cmd_bootm.c Architecture check OK
1812 -106 common/cmd_bootm.c Kernel subimage has wrong typea
1813 107 common/cmd_bootm.c Kernel subimge type OK
1814 -107 common/cmd_bootm.c Can't get kernel subimage data/size
1815 108 common/cmd_bootm.c Got kernel subimage data/size
1816 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT)
1817 -109 common/cmd_bootm.c Can't get kernel subimage type
1818 -110 common/cmd_bootm.c Can't get kernel subimage comp
1819 -111 common/cmd_bootm.c Can't get kernel subimage os
1820 -112 common/cmd_bootm.c Can't get kernel subimage load address
1821 -113 common/cmd_bootm.c Image uncompress/copy overwrite error
1823 120 common/image.c Start initial ramdisk verification
1824 -120 common/image.c Ramdisk FIT image has incorrect format
1825 121 common/image.c Ramdisk FIT image has correct format
1826 122 common/image.c No Ramdisk subimage unit name, using configuration
1827 -122 common/image.c Can't get configuration for ramdisk subimage
1828 123 common/image.c Ramdisk unit name specified
1829 -124 common/image.c Can't get ramdisk subimage node offset
1830 125 common/image.c Got ramdisk subimage node offset
1831 -125 common/image.c Ramdisk subimage hash verification failed
1832 126 common/image.c Ramdisk subimage hash verification OK
1833 -126 common/image.c Ramdisk subimage for unsupported architecture
1834 127 common/image.c Architecture check OK
1835 -127 common/image.c Can't get ramdisk subimage data/size
1836 128 common/image.c Got ramdisk subimage data/size
1837 129 common/image.c Can't get ramdisk load address
1838 -129 common/image.c Got ramdisk load address
1840 -130 common/cmd_doc.c Icorrect FIT image format
1841 131 common/cmd_doc.c FIT image format OK
1843 -140 common/cmd_ide.c Icorrect FIT image format
1844 141 common/cmd_ide.c FIT image format OK
1846 -150 common/cmd_nand.c Icorrect FIT image format
1847 151 common/cmd_nand.c FIT image format OK
1853 [so far only for SMDK2400 and TRAB boards]
1855 - Modem support endable:
1856 CONFIG_MODEM_SUPPORT
1858 - RTS/CTS Flow control enable:
1861 - Modem debug support:
1862 CONFIG_MODEM_SUPPORT_DEBUG
1864 Enables debugging stuff (char screen[1024], dbg())
1865 for modem support. Useful only with BDI2000.
1867 - Interrupt support (PPC):
1869 There are common interrupt_init() and timer_interrupt()
1870 for all PPC archs. interrupt_init() calls interrupt_init_cpu()
1871 for cpu specific initialization. interrupt_init_cpu()
1872 should set decrementer_count to appropriate value. If
1873 cpu resets decrementer automatically after interrupt
1874 (ppc4xx) it should set decrementer_count to zero.
1875 timer_interrupt() calls timer_interrupt_cpu() for cpu
1876 specific handling. If board has watchdog / status_led
1877 / other_activity_monitor it works automatically from
1878 general timer_interrupt().
1882 In the target system modem support is enabled when a
1883 specific key (key combination) is pressed during
1884 power-on. Otherwise U-Boot will boot normally
1885 (autoboot). The key_pressed() fuction is called from
1886 board_init(). Currently key_pressed() is a dummy
1887 function, returning 1 and thus enabling modem
1890 If there are no modem init strings in the
1891 environment, U-Boot proceed to autoboot; the
1892 previous output (banner, info printfs) will be
1895 See also: doc/README.Modem
1898 Configuration Settings:
1899 -----------------------
1901 - CFG_LONGHELP: Defined when you want long help messages included;
1902 undefine this when you're short of memory.
1904 - CFG_PROMPT: This is what U-Boot prints on the console to
1905 prompt for user input.
1907 - CFG_CBSIZE: Buffer size for input from the Console
1909 - CFG_PBSIZE: Buffer size for Console output
1911 - CFG_MAXARGS: max. Number of arguments accepted for monitor commands
1913 - CFG_BARGSIZE: Buffer size for Boot Arguments which are passed to
1914 the application (usually a Linux kernel) when it is
1917 - CFG_BAUDRATE_TABLE:
1918 List of legal baudrate settings for this board.
1920 - CFG_CONSOLE_INFO_QUIET
1921 Suppress display of console information at boot.
1923 - CFG_CONSOLE_IS_IN_ENV
1924 If the board specific function
1925 extern int overwrite_console (void);
1926 returns 1, the stdin, stderr and stdout are switched to the
1927 serial port, else the settings in the environment are used.
1929 - CFG_CONSOLE_OVERWRITE_ROUTINE
1930 Enable the call to overwrite_console().
1932 - CFG_CONSOLE_ENV_OVERWRITE
1933 Enable overwrite of previous console environment settings.
1935 - CFG_MEMTEST_START, CFG_MEMTEST_END:
1936 Begin and End addresses of the area used by the
1940 Enable an alternate, more extensive memory test.
1942 - CFG_MEMTEST_SCRATCH:
1943 Scratch address used by the alternate memory test
1944 You only need to set this if address zero isn't writeable
1946 - CFG_TFTP_LOADADDR:
1947 Default load address for network file downloads
1949 - CFG_LOADS_BAUD_CHANGE:
1950 Enable temporary baudrate change while serial download
1953 Physical start address of SDRAM. _Must_ be 0 here.
1956 Physical start address of Motherboard I/O (if using a
1960 Physical start address of Flash memory.
1963 Physical start address of boot monitor code (set by
1964 make config files to be same as the text base address
1965 (TEXT_BASE) used when linking) - same as
1966 CFG_FLASH_BASE when booting from flash.
1969 Size of memory reserved for monitor code, used to
1970 determine _at_compile_time_ (!) if the environment is
1971 embedded within the U-Boot image, or in a separate
1975 Size of DRAM reserved for malloc() use.
1978 Normally compressed uImages are limited to an
1979 uncompressed size of 8 MBytes. If this is not enough,
1980 you can define CFG_BOOTM_LEN in your board config file
1981 to adjust this setting to your needs.
1984 Maximum size of memory mapped by the startup code of
1985 the Linux kernel; all data that must be processed by
1986 the Linux kernel (bd_info, boot arguments, eventually
1987 initrd image) must be put below this limit.
1989 - CFG_MAX_FLASH_BANKS:
1990 Max number of Flash memory banks
1992 - CFG_MAX_FLASH_SECT:
1993 Max number of sectors on a Flash chip
1995 - CFG_FLASH_ERASE_TOUT:
1996 Timeout for Flash erase operations (in ms)
1998 - CFG_FLASH_WRITE_TOUT:
1999 Timeout for Flash write operations (in ms)
2001 - CFG_FLASH_LOCK_TOUT
2002 Timeout for Flash set sector lock bit operation (in ms)
2004 - CFG_FLASH_UNLOCK_TOUT
2005 Timeout for Flash clear lock bits operation (in ms)
2007 - CFG_FLASH_PROTECTION
2008 If defined, hardware flash sectors protection is used
2009 instead of U-Boot software protection.
2011 - CFG_DIRECT_FLASH_TFTP:
2013 Enable TFTP transfers directly to flash memory;
2014 without this option such a download has to be
2015 performed in two steps: (1) download to RAM, and (2)
2016 copy from RAM to flash.
2018 The two-step approach is usually more reliable, since
2019 you can check if the download worked before you erase
2020 the flash, but in some situations (when sytem RAM is
2021 too limited to allow for a tempory copy of the
2022 downloaded image) this option may be very useful.
2025 Define if the flash driver uses extra elements in the
2026 common flash structure for storing flash geometry.
2028 - CFG_FLASH_CFI_DRIVER
2029 This option also enables the building of the cfi_flash driver
2030 in the drivers directory
2032 - CFG_FLASH_QUIET_TEST
2033 If this option is defined, the common CFI flash doesn't
2034 print it's warning upon not recognized FLASH banks. This
2035 is useful, if some of the configured banks are only
2036 optionally available.
2038 - CONFIG_FLASH_SHOW_PROGRESS
2039 If defined (must be an integer), print out countdown
2040 digits and dots. Recommended value: 45 (9..1) for 80
2041 column displays, 15 (3..1) for 40 column displays.
2043 - CFG_RX_ETH_BUFFER:
2044 Defines the number of ethernet receive buffers. On some
2045 ethernet controllers it is recommended to set this value
2046 to 8 or even higher (EEPRO100 or 405 EMAC), since all
2047 buffers can be full shortly after enabling the interface
2048 on high ethernet traffic.
2049 Defaults to 4 if not defined.
2051 The following definitions that deal with the placement and management
2052 of environment data (variable area); in general, we support the
2053 following configurations:
2055 - CFG_ENV_IS_IN_FLASH:
2057 Define this if the environment is in flash memory.
2059 a) The environment occupies one whole flash sector, which is
2060 "embedded" in the text segment with the U-Boot code. This
2061 happens usually with "bottom boot sector" or "top boot
2062 sector" type flash chips, which have several smaller
2063 sectors at the start or the end. For instance, such a
2064 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In
2065 such a case you would place the environment in one of the
2066 4 kB sectors - with U-Boot code before and after it. With
2067 "top boot sector" type flash chips, you would put the
2068 environment in one of the last sectors, leaving a gap
2069 between U-Boot and the environment.
2073 Offset of environment data (variable area) to the
2074 beginning of flash memory; for instance, with bottom boot
2075 type flash chips the second sector can be used: the offset
2076 for this sector is given here.
2078 CFG_ENV_OFFSET is used relative to CFG_FLASH_BASE.
2082 This is just another way to specify the start address of
2083 the flash sector containing the environment (instead of
2086 - CFG_ENV_SECT_SIZE:
2088 Size of the sector containing the environment.
2091 b) Sometimes flash chips have few, equal sized, BIG sectors.
2092 In such a case you don't want to spend a whole sector for
2097 If you use this in combination with CFG_ENV_IS_IN_FLASH
2098 and CFG_ENV_SECT_SIZE, you can specify to use only a part
2099 of this flash sector for the environment. This saves
2100 memory for the RAM copy of the environment.
2102 It may also save flash memory if you decide to use this
2103 when your environment is "embedded" within U-Boot code,
2104 since then the remainder of the flash sector could be used
2105 for U-Boot code. It should be pointed out that this is
2106 STRONGLY DISCOURAGED from a robustness point of view:
2107 updating the environment in flash makes it always
2108 necessary to erase the WHOLE sector. If something goes
2109 wrong before the contents has been restored from a copy in
2110 RAM, your target system will be dead.
2112 - CFG_ENV_ADDR_REDUND
2115 These settings describe a second storage area used to hold
2116 a redundand copy of the environment data, so that there is
2117 a valid backup copy in case there is a power failure during
2118 a "saveenv" operation.
2120 BE CAREFUL! Any changes to the flash layout, and some changes to the
2121 source code will make it necessary to adapt <board>/u-boot.lds*
2125 - CFG_ENV_IS_IN_NVRAM:
2127 Define this if you have some non-volatile memory device
2128 (NVRAM, battery buffered SRAM) which you want to use for the
2134 These two #defines are used to determin the memory area you
2135 want to use for environment. It is assumed that this memory
2136 can just be read and written to, without any special
2139 BE CAREFUL! The first access to the environment happens quite early
2140 in U-Boot initalization (when we try to get the setting of for the
2141 console baudrate). You *MUST* have mappend your NVRAM area then, or
2144 Please note that even with NVRAM we still use a copy of the
2145 environment in RAM: we could work on NVRAM directly, but we want to
2146 keep settings there always unmodified except somebody uses "saveenv"
2147 to save the current settings.
2150 - CFG_ENV_IS_IN_EEPROM:
2152 Use this if you have an EEPROM or similar serial access
2153 device and a driver for it.
2158 These two #defines specify the offset and size of the
2159 environment area within the total memory of your EEPROM.
2161 - CFG_I2C_EEPROM_ADDR:
2162 If defined, specified the chip address of the EEPROM device.
2163 The default address is zero.
2165 - CFG_EEPROM_PAGE_WRITE_BITS:
2166 If defined, the number of bits used to address bytes in a
2167 single page in the EEPROM device. A 64 byte page, for example
2168 would require six bits.
2170 - CFG_EEPROM_PAGE_WRITE_DELAY_MS:
2171 If defined, the number of milliseconds to delay between
2172 page writes. The default is zero milliseconds.
2174 - CFG_I2C_EEPROM_ADDR_LEN:
2175 The length in bytes of the EEPROM memory array address. Note
2176 that this is NOT the chip address length!
2178 - CFG_I2C_EEPROM_ADDR_OVERFLOW:
2179 EEPROM chips that implement "address overflow" are ones
2180 like Catalyst 24WC04/08/16 which has 9/10/11 bits of
2181 address and the extra bits end up in the "chip address" bit
2182 slots. This makes a 24WC08 (1Kbyte) chip look like four 256
2185 Note that we consider the length of the address field to
2186 still be one byte because the extra address bits are hidden
2187 in the chip address.
2190 The size in bytes of the EEPROM device.
2193 - CFG_ENV_IS_IN_DATAFLASH:
2195 Define this if you have a DataFlash memory device which you
2196 want to use for the environment.
2202 These three #defines specify the offset and size of the
2203 environment area within the total memory of your DataFlash placed
2204 at the specified address.
2206 - CFG_ENV_IS_IN_NAND:
2208 Define this if you have a NAND device which you want to use
2209 for the environment.
2214 These two #defines specify the offset and size of the environment
2215 area within the first NAND device.
2217 - CFG_ENV_OFFSET_REDUND
2219 This setting describes a second storage area of CFG_ENV_SIZE
2220 size used to hold a redundant copy of the environment data,
2221 so that there is a valid backup copy in case there is a
2222 power failure during a "saveenv" operation.
2224 Note: CFG_ENV_OFFSET and CFG_ENV_OFFSET_REDUND must be aligned
2225 to a block boundary, and CFG_ENV_SIZE must be a multiple of
2226 the NAND devices block size.
2228 - CFG_SPI_INIT_OFFSET
2230 Defines offset to the initial SPI buffer area in DPRAM. The
2231 area is used at an early stage (ROM part) if the environment
2232 is configured to reside in the SPI EEPROM: We need a 520 byte
2233 scratch DPRAM area. It is used between the two initialization
2234 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems
2235 to be a good choice since it makes it far enough from the
2236 start of the data area as well as from the stack pointer.
2238 Please note that the environment is read-only until the monitor
2239 has been relocated to RAM and a RAM copy of the environment has been
2240 created; also, when using EEPROM you will have to use getenv_r()
2241 until then to read environment variables.
2243 The environment is protected by a CRC32 checksum. Before the monitor
2244 is relocated into RAM, as a result of a bad CRC you will be working
2245 with the compiled-in default environment - *silently*!!! [This is
2246 necessary, because the first environment variable we need is the
2247 "baudrate" setting for the console - if we have a bad CRC, we don't
2248 have any device yet where we could complain.]
2250 Note: once the monitor has been relocated, then it will complain if
2251 the default environment is used; a new CRC is computed as soon as you
2252 use the "saveenv" command to store a valid environment.
2254 - CFG_FAULT_ECHO_LINK_DOWN:
2255 Echo the inverted Ethernet link state to the fault LED.
2257 Note: If this option is active, then CFG_FAULT_MII_ADDR
2258 also needs to be defined.
2260 - CFG_FAULT_MII_ADDR:
2261 MII address of the PHY to check for the Ethernet link state.
2263 - CFG_64BIT_VSPRINTF:
2264 Makes vsprintf (and all *printf functions) support printing
2265 of 64bit values by using the L quantifier
2267 - CFG_64BIT_STRTOUL:
2268 Adds simple_strtoull that returns a 64bit value
2270 Low Level (hardware related) configuration options:
2271 ---------------------------------------------------
2273 - CFG_CACHELINE_SIZE:
2274 Cache Line Size of the CPU.
2277 Default address of the IMMR after system reset.
2279 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU,
2280 and RPXsuper) to be able to adjust the position of
2281 the IMMR register after a reset.
2283 - Floppy Disk Support:
2284 CFG_FDC_DRIVE_NUMBER
2286 the default drive number (default value 0)
2290 defines the spacing between fdc chipset registers
2295 defines the offset of register from address. It
2296 depends on which part of the data bus is connected to
2297 the fdc chipset. (default value 0)
2299 If CFG_ISA_IO_STRIDE CFG_ISA_IO_OFFSET and
2300 CFG_FDC_DRIVE_NUMBER are undefined, they take their
2303 if CFG_FDC_HW_INIT is defined, then the function
2304 fdc_hw_init() is called at the beginning of the FDC
2305 setup. fdc_hw_init() must be provided by the board
2306 source code. It is used to make hardware dependant
2309 - CFG_IMMR: Physical address of the Internal Memory.
2310 DO NOT CHANGE unless you know exactly what you're
2311 doing! (11-4) [MPC8xx/82xx systems only]
2313 - CFG_INIT_RAM_ADDR:
2315 Start address of memory area that can be used for
2316 initial data and stack; please note that this must be
2317 writable memory that is working WITHOUT special
2318 initialization, i. e. you CANNOT use normal RAM which
2319 will become available only after programming the
2320 memory controller and running certain initialization
2323 U-Boot uses the following memory types:
2324 - MPC8xx and MPC8260: IMMR (internal memory of the CPU)
2325 - MPC824X: data cache
2326 - PPC4xx: data cache
2328 - CFG_GBL_DATA_OFFSET:
2330 Offset of the initial data structure in the memory
2331 area defined by CFG_INIT_RAM_ADDR. Usually
2332 CFG_GBL_DATA_OFFSET is chosen such that the initial
2333 data is located at the end of the available space
2334 (sometimes written as (CFG_INIT_RAM_END -
2335 CFG_INIT_DATA_SIZE), and the initial stack is just
2336 below that area (growing from (CFG_INIT_RAM_ADDR +
2337 CFG_GBL_DATA_OFFSET) downward.
2340 On the MPC824X (or other systems that use the data
2341 cache for initial memory) the address chosen for
2342 CFG_INIT_RAM_ADDR is basically arbitrary - it must
2343 point to an otherwise UNUSED address space between
2344 the top of RAM and the start of the PCI space.
2346 - CFG_SIUMCR: SIU Module Configuration (11-6)
2348 - CFG_SYPCR: System Protection Control (11-9)
2350 - CFG_TBSCR: Time Base Status and Control (11-26)
2352 - CFG_PISCR: Periodic Interrupt Status and Control (11-31)
2354 - CFG_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30)
2356 - CFG_SCCR: System Clock and reset Control Register (15-27)
2358 - CFG_OR_TIMING_SDRAM:
2362 periodic timer for refresh
2364 - CFG_DER: Debug Event Register (37-47)
2366 - FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CFG_REMAP_OR_AM,
2367 CFG_PRELIM_OR_AM, CFG_OR_TIMING_FLASH, CFG_OR0_REMAP,
2368 CFG_OR0_PRELIM, CFG_BR0_PRELIM, CFG_OR1_REMAP, CFG_OR1_PRELIM,
2370 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
2372 - SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
2373 CFG_OR_TIMING_SDRAM, CFG_OR2_PRELIM, CFG_BR2_PRELIM,
2374 CFG_OR3_PRELIM, CFG_BR3_PRELIM:
2375 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
2377 - CFG_MAMR_PTA, CFG_MPTPR_2BK_4K, CFG_MPTPR_1BK_4K, CFG_MPTPR_2BK_8K,
2378 CFG_MPTPR_1BK_8K, CFG_MAMR_8COL, CFG_MAMR_9COL:
2379 Machine Mode Register and Memory Periodic Timer
2380 Prescaler definitions (SDRAM timing)
2382 - CFG_I2C_UCODE_PATCH, CFG_I2C_DPMEM_OFFSET [0x1FC0]:
2383 enable I2C microcode relocation patch (MPC8xx);
2384 define relocation offset in DPRAM [DSP2]
2386 - CFG_SMC_UCODE_PATCH, CFG_SMC_DPMEM_OFFSET [0x1FC0]:
2387 enable SMC microcode relocation patch (MPC8xx);
2388 define relocation offset in DPRAM [SMC1]
2390 - CFG_SPI_UCODE_PATCH, CFG_SPI_DPMEM_OFFSET [0x1FC0]:
2391 enable SPI microcode relocation patch (MPC8xx);
2392 define relocation offset in DPRAM [SCC4]
2395 Use OSCM clock mode on MBX8xx board. Be careful,
2396 wrong setting might damage your board. Read
2397 doc/README.MBX before setting this variable!
2399 - CFG_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only)
2400 Offset of the bootmode word in DPRAM used by post
2401 (Power On Self Tests). This definition overrides
2402 #define'd default value in commproc.h resp.
2405 - CFG_PCI_SLV_MEM_LOCAL, CFG_PCI_SLV_MEM_BUS, CFG_PICMR0_MASK_ATTRIB,
2406 CFG_PCI_MSTR0_LOCAL, CFG_PCIMSK0_MASK, CFG_PCI_MSTR1_LOCAL,
2407 CFG_PCIMSK1_MASK, CFG_PCI_MSTR_MEM_LOCAL, CFG_PCI_MSTR_MEM_BUS,
2408 CFG_CPU_PCI_MEM_START, CFG_PCI_MSTR_MEM_SIZE, CFG_POCMR0_MASK_ATTRIB,
2409 CFG_PCI_MSTR_MEMIO_LOCAL, CFG_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START,
2410 CFG_PCI_MSTR_MEMIO_SIZE, CFG_POCMR1_MASK_ATTRIB, CFG_PCI_MSTR_IO_LOCAL,
2411 CFG_PCI_MSTR_IO_BUS, CFG_CPU_PCI_IO_START, CFG_PCI_MSTR_IO_SIZE,
2412 CFG_POCMR2_MASK_ATTRIB: (MPC826x only)
2413 Overrides the default PCI memory map in cpu/mpc8260/pci.c if set.
2416 Get DDR timing information from an I2C EEPROM. Common
2417 with pluggable memory modules such as SODIMMs
2420 I2C address of the SPD EEPROM
2423 If SPD EEPROM is on an I2C bus other than the first
2424 one, specify here. Note that the value must resolve
2425 to something your driver can deal with.
2427 - CFG_83XX_DDR_USES_CS0
2428 Only for 83xx systems. If specified, then DDR should
2429 be configured using CS0 and CS1 instead of CS2 and CS3.
2431 - CFG_83XX_DDR_USES_CS0
2432 Only for 83xx systems. If specified, then DDR should
2433 be configured using CS0 and CS1 instead of CS2 and CS3.
2435 - CONFIG_ETHER_ON_FEC[12]
2436 Define to enable FEC[12] on a 8xx series processor.
2438 - CONFIG_FEC[12]_PHY
2439 Define to the hardcoded PHY address which corresponds
2440 to the given FEC; i. e.
2441 #define CONFIG_FEC1_PHY 4
2442 means that the PHY with address 4 is connected to FEC1
2444 When set to -1, means to probe for first available.
2446 - CONFIG_FEC[12]_PHY_NORXERR
2447 The PHY does not have a RXERR line (RMII only).
2448 (so program the FEC to ignore it).
2451 Enable RMII mode for all FECs.
2452 Note that this is a global option, we can't
2453 have one FEC in standard MII mode and another in RMII mode.
2455 - CONFIG_CRC32_VERIFY
2456 Add a verify option to the crc32 command.
2459 => crc32 -v <address> <count> <crc32>
2461 Where address/count indicate a memory area
2462 and crc32 is the correct crc32 which the
2466 Add the "loopw" memory command. This only takes effect if
2467 the memory commands are activated globally (CONFIG_CMD_MEM).
2470 Add the "mdc" and "mwc" memory commands. These are cyclic
2475 This command will print 4 bytes (10,11,12,13) each 500 ms.
2477 => mwc.l 100 12345678 10
2478 This command will write 12345678 to address 100 all 10 ms.
2480 This only takes effect if the memory commands are activated
2481 globally (CONFIG_CMD_MEM).
2483 - CONFIG_SKIP_LOWLEVEL_INIT
2484 - CONFIG_SKIP_RELOCATE_UBOOT
2486 [ARM only] If these variables are defined, then
2487 certain low level initializations (like setting up
2488 the memory controller) are omitted and/or U-Boot does
2489 not relocate itself into RAM.
2490 Normally these variables MUST NOT be defined. The
2491 only exception is when U-Boot is loaded (to RAM) by
2492 some other boot loader or by a debugger which
2493 performs these intializations itself.
2496 Building the Software:
2497 ======================
2499 Building U-Boot has been tested in several native build environments
2500 and in many different cross environments. Of course we cannot support
2501 all possibly existing versions of cross development tools in all
2502 (potentially obsolete) versions. In case of tool chain problems we
2503 recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK)
2504 which is extensively used to build and test U-Boot.
2506 If you are not using a native environment, it is assumed that you
2507 have GNU cross compiling tools available in your path. In this case,
2508 you must set the environment variable CROSS_COMPILE in your shell.
2509 Note that no changes to the Makefile or any other source files are
2510 necessary. For example using the ELDK on a 4xx CPU, please enter:
2512 $ CROSS_COMPILE=ppc_4xx-
2513 $ export CROSS_COMPILE
2515 U-Boot is intended to be simple to build. After installing the
2516 sources you must configure U-Boot for one specific board type. This
2521 where "NAME_config" is the name of one of the existing configu-
2522 rations; see the main Makefile for supported names.
2524 Note: for some board special configuration names may exist; check if
2525 additional information is available from the board vendor; for
2526 instance, the TQM823L systems are available without (standard)
2527 or with LCD support. You can select such additional "features"
2528 when chosing the configuration, i. e.
2531 - will configure for a plain TQM823L, i. e. no LCD support
2533 make TQM823L_LCD_config
2534 - will configure for a TQM823L with U-Boot console on LCD
2539 Finally, type "make all", and you should get some working U-Boot
2540 images ready for download to / installation on your system:
2542 - "u-boot.bin" is a raw binary image
2543 - "u-boot" is an image in ELF binary format
2544 - "u-boot.srec" is in Motorola S-Record format
2546 By default the build is performed locally and the objects are saved
2547 in the source directory. One of the two methods can be used to change
2548 this behavior and build U-Boot to some external directory:
2550 1. Add O= to the make command line invocations:
2552 make O=/tmp/build distclean
2553 make O=/tmp/build NAME_config
2554 make O=/tmp/build all
2556 2. Set environment variable BUILD_DIR to point to the desired location:
2558 export BUILD_DIR=/tmp/build
2563 Note that the command line "O=" setting overrides the BUILD_DIR environment
2567 Please be aware that the Makefiles assume you are using GNU make, so
2568 for instance on NetBSD you might need to use "gmake" instead of
2572 If the system board that you have is not listed, then you will need
2573 to port U-Boot to your hardware platform. To do this, follow these
2576 1. Add a new configuration option for your board to the toplevel
2577 "Makefile" and to the "MAKEALL" script, using the existing
2578 entries as examples. Note that here and at many other places
2579 boards and other names are listed in alphabetical sort order. Please
2581 2. Create a new directory to hold your board specific code. Add any
2582 files you need. In your board directory, you will need at least
2583 the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds".
2584 3. Create a new configuration file "include/configs/<board>.h" for
2586 3. If you're porting U-Boot to a new CPU, then also create a new
2587 directory to hold your CPU specific code. Add any files you need.
2588 4. Run "make <board>_config" with your new name.
2589 5. Type "make", and you should get a working "u-boot.srec" file
2590 to be installed on your target system.
2591 6. Debug and solve any problems that might arise.
2592 [Of course, this last step is much harder than it sounds.]
2595 Testing of U-Boot Modifications, Ports to New Hardware, etc.:
2596 ==============================================================
2598 If you have modified U-Boot sources (for instance added a new board
2599 or support for new devices, a new CPU, etc.) you are expected to
2600 provide feedback to the other developers. The feedback normally takes
2601 the form of a "patch", i. e. a context diff against a certain (latest
2602 official or latest in the git repository) version of U-Boot sources.
2604 But before you submit such a patch, please verify that your modifi-
2605 cation did not break existing code. At least make sure that *ALL* of
2606 the supported boards compile WITHOUT ANY compiler warnings. To do so,
2607 just run the "MAKEALL" script, which will configure and build U-Boot
2608 for ALL supported system. Be warned, this will take a while. You can
2609 select which (cross) compiler to use by passing a `CROSS_COMPILE'
2610 environment variable to the script, i. e. to use the ELDK cross tools
2613 CROSS_COMPILE=ppc_8xx- MAKEALL
2615 or to build on a native PowerPC system you can type
2617 CROSS_COMPILE=' ' MAKEALL
2619 When using the MAKEALL script, the default behaviour is to build
2620 U-Boot in the source directory. This location can be changed by
2621 setting the BUILD_DIR environment variable. Also, for each target
2622 built, the MAKEALL script saves two log files (<target>.ERR and
2623 <target>.MAKEALL) in the <source dir>/LOG directory. This default
2624 location can be changed by setting the MAKEALL_LOGDIR environment
2625 variable. For example:
2627 export BUILD_DIR=/tmp/build
2628 export MAKEALL_LOGDIR=/tmp/log
2629 CROSS_COMPILE=ppc_8xx- MAKEALL
2631 With the above settings build objects are saved in the /tmp/build,
2632 log files are saved in the /tmp/log and the source tree remains clean
2633 during the whole build process.
2636 See also "U-Boot Porting Guide" below.
2639 Monitor Commands - Overview:
2640 ============================
2642 go - start application at address 'addr'
2643 run - run commands in an environment variable
2644 bootm - boot application image from memory
2645 bootp - boot image via network using BootP/TFTP protocol
2646 tftpboot- boot image via network using TFTP protocol
2647 and env variables "ipaddr" and "serverip"
2648 (and eventually "gatewayip")
2649 rarpboot- boot image via network using RARP/TFTP protocol
2650 diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
2651 loads - load S-Record file over serial line
2652 loadb - load binary file over serial line (kermit mode)
2654 mm - memory modify (auto-incrementing)
2655 nm - memory modify (constant address)
2656 mw - memory write (fill)
2658 cmp - memory compare
2659 crc32 - checksum calculation
2660 imd - i2c memory display
2661 imm - i2c memory modify (auto-incrementing)
2662 inm - i2c memory modify (constant address)
2663 imw - i2c memory write (fill)
2664 icrc32 - i2c checksum calculation
2665 iprobe - probe to discover valid I2C chip addresses
2666 iloop - infinite loop on address range
2667 isdram - print SDRAM configuration information
2668 sspi - SPI utility commands
2669 base - print or set address offset
2670 printenv- print environment variables
2671 setenv - set environment variables
2672 saveenv - save environment variables to persistent storage
2673 protect - enable or disable FLASH write protection
2674 erase - erase FLASH memory
2675 flinfo - print FLASH memory information
2676 bdinfo - print Board Info structure
2677 iminfo - print header information for application image
2678 coninfo - print console devices and informations
2679 ide - IDE sub-system
2680 loop - infinite loop on address range
2681 loopw - infinite write loop on address range
2682 mtest - simple RAM test
2683 icache - enable or disable instruction cache
2684 dcache - enable or disable data cache
2685 reset - Perform RESET of the CPU
2686 echo - echo args to console
2687 version - print monitor version
2688 help - print online help
2689 ? - alias for 'help'
2692 Monitor Commands - Detailed Description:
2693 ========================================
2697 For now: just type "help <command>".
2700 Environment Variables:
2701 ======================
2703 U-Boot supports user configuration using Environment Variables which
2704 can be made persistent by saving to Flash memory.
2706 Environment Variables are set using "setenv", printed using
2707 "printenv", and saved to Flash using "saveenv". Using "setenv"
2708 without a value can be used to delete a variable from the
2709 environment. As long as you don't save the environment you are
2710 working with an in-memory copy. In case the Flash area containing the
2711 environment is erased by accident, a default environment is provided.
2713 Some configuration options can be set using Environment Variables:
2715 baudrate - see CONFIG_BAUDRATE
2717 bootdelay - see CONFIG_BOOTDELAY
2719 bootcmd - see CONFIG_BOOTCOMMAND
2721 bootargs - Boot arguments when booting an RTOS image
2723 bootfile - Name of the image to load with TFTP
2725 autoload - if set to "no" (any string beginning with 'n'),
2726 "bootp" will just load perform a lookup of the
2727 configuration from the BOOTP server, but not try to
2728 load any image using TFTP
2730 autoscript - if set to "yes" commands like "loadb", "loady",
2731 "bootp", "tftpb", "rarpboot" and "nfs" will attempt
2732 to automatically run script images (by internally
2733 calling "autoscript").
2735 autoscript_uname - if script image is in a format (FIT) this
2736 variable is used to get script subimage unit name.
2738 autostart - if set to "yes", an image loaded using the "bootp",
2739 "rarpboot", "tftpboot" or "diskboot" commands will
2740 be automatically started (by internally calling
2743 If set to "no", a standalone image passed to the
2744 "bootm" command will be copied to the load address
2745 (and eventually uncompressed), but NOT be started.
2746 This can be used to load and uncompress arbitrary
2749 i2cfast - (PPC405GP|PPC405EP only)
2750 if set to 'y' configures Linux I2C driver for fast
2751 mode (400kHZ). This environment variable is used in
2752 initialization code. So, for changes to be effective
2753 it must be saved and board must be reset.
2755 initrd_high - restrict positioning of initrd images:
2756 If this variable is not set, initrd images will be
2757 copied to the highest possible address in RAM; this
2758 is usually what you want since it allows for
2759 maximum initrd size. If for some reason you want to
2760 make sure that the initrd image is loaded below the
2761 CFG_BOOTMAPSZ limit, you can set this environment
2762 variable to a value of "no" or "off" or "0".
2763 Alternatively, you can set it to a maximum upper
2764 address to use (U-Boot will still check that it
2765 does not overwrite the U-Boot stack and data).
2767 For instance, when you have a system with 16 MB
2768 RAM, and want to reserve 4 MB from use by Linux,
2769 you can do this by adding "mem=12M" to the value of
2770 the "bootargs" variable. However, now you must make
2771 sure that the initrd image is placed in the first
2772 12 MB as well - this can be done with
2774 setenv initrd_high 00c00000
2776 If you set initrd_high to 0xFFFFFFFF, this is an
2777 indication to U-Boot that all addresses are legal
2778 for the Linux kernel, including addresses in flash
2779 memory. In this case U-Boot will NOT COPY the
2780 ramdisk at all. This may be useful to reduce the
2781 boot time on your system, but requires that this
2782 feature is supported by your Linux kernel.
2784 ipaddr - IP address; needed for tftpboot command
2786 loadaddr - Default load address for commands like "bootp",
2787 "rarpboot", "tftpboot", "loadb" or "diskboot"
2789 loads_echo - see CONFIG_LOADS_ECHO
2791 serverip - TFTP server IP address; needed for tftpboot command
2793 bootretry - see CONFIG_BOOT_RETRY_TIME
2795 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
2797 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
2799 ethprime - When CONFIG_NET_MULTI is enabled controls which
2800 interface is used first.
2802 ethact - When CONFIG_NET_MULTI is enabled controls which
2803 interface is currently active. For example you
2804 can do the following
2806 => setenv ethact FEC ETHERNET
2807 => ping 192.168.0.1 # traffic sent on FEC ETHERNET
2808 => setenv ethact SCC ETHERNET
2809 => ping 10.0.0.1 # traffic sent on SCC ETHERNET
2811 ethrotate - When set to "no" U-Boot does not go through all
2812 available network interfaces.
2813 It just stays at the currently selected interface.
2815 netretry - When set to "no" each network operation will
2816 either succeed or fail without retrying.
2817 When set to "once" the network operation will
2818 fail when all the available network interfaces
2819 are tried once without success.
2820 Useful on scripts which control the retry operation
2823 npe_ucode - see CONFIG_IXP4XX_NPE_EXT_UCOD
2824 if set load address for the npe microcode
2826 tftpsrcport - If this is set, the value is used for TFTP's
2829 tftpdstport - If this is set, the value is used for TFTP's UDP
2830 destination port instead of the Well Know Port 69.
2832 vlan - When set to a value < 4095 the traffic over
2833 ethernet is encapsulated/received over 802.1q
2836 The following environment variables may be used and automatically
2837 updated by the network boot commands ("bootp" and "rarpboot"),
2838 depending the information provided by your boot server:
2840 bootfile - see above
2841 dnsip - IP address of your Domain Name Server
2842 dnsip2 - IP address of your secondary Domain Name Server
2843 gatewayip - IP address of the Gateway (Router) to use
2844 hostname - Target hostname
2846 netmask - Subnet Mask
2847 rootpath - Pathname of the root filesystem on the NFS server
2848 serverip - see above
2851 There are two special Environment Variables:
2853 serial# - contains hardware identification information such
2854 as type string and/or serial number
2855 ethaddr - Ethernet address
2857 These variables can be set only once (usually during manufacturing of
2858 the board). U-Boot refuses to delete or overwrite these variables
2859 once they have been set once.
2862 Further special Environment Variables:
2864 ver - Contains the U-Boot version string as printed
2865 with the "version" command. This variable is
2866 readonly (see CONFIG_VERSION_VARIABLE).
2869 Please note that changes to some configuration parameters may take
2870 only effect after the next boot (yes, that's just like Windoze :-).
2873 Command Line Parsing:
2874 =====================
2876 There are two different command line parsers available with U-Boot:
2877 the old "simple" one, and the much more powerful "hush" shell:
2879 Old, simple command line parser:
2880 --------------------------------
2882 - supports environment variables (through setenv / saveenv commands)
2883 - several commands on one line, separated by ';'
2884 - variable substitution using "... ${name} ..." syntax
2885 - special characters ('$', ';') can be escaped by prefixing with '\',
2887 setenv bootcmd bootm \${address}
2888 - You can also escape text by enclosing in single apostrophes, for example:
2889 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
2894 - similar to Bourne shell, with control structures like
2895 if...then...else...fi, for...do...done; while...do...done,
2896 until...do...done, ...
2897 - supports environment ("global") variables (through setenv / saveenv
2898 commands) and local shell variables (through standard shell syntax
2899 "name=value"); only environment variables can be used with "run"
2905 (1) If a command line (or an environment variable executed by a "run"
2906 command) contains several commands separated by semicolon, and
2907 one of these commands fails, then the remaining commands will be
2910 (2) If you execute several variables with one call to run (i. e.
2911 calling run with a list af variables as arguments), any failing
2912 command will cause "run" to terminate, i. e. the remaining
2913 variables are not executed.
2915 Note for Redundant Ethernet Interfaces:
2916 =======================================
2918 Some boards come with redundant ethernet interfaces; U-Boot supports
2919 such configurations and is capable of automatic selection of a
2920 "working" interface when needed. MAC assignment works as follows:
2922 Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
2923 MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
2924 "eth1addr" (=>eth1), "eth2addr", ...
2926 If the network interface stores some valid MAC address (for instance
2927 in SROM), this is used as default address if there is NO correspon-
2928 ding setting in the environment; if the corresponding environment
2929 variable is set, this overrides the settings in the card; that means:
2931 o If the SROM has a valid MAC address, and there is no address in the
2932 environment, the SROM's address is used.
2934 o If there is no valid address in the SROM, and a definition in the
2935 environment exists, then the value from the environment variable is
2938 o If both the SROM and the environment contain a MAC address, and
2939 both addresses are the same, this MAC address is used.
2941 o If both the SROM and the environment contain a MAC address, and the
2942 addresses differ, the value from the environment is used and a
2945 o If neither SROM nor the environment contain a MAC address, an error
2952 U-Boot is capable of booting (and performing other auxiliary operations on)
2953 images in two formats:
2955 New uImage format (FIT)
2956 -----------------------
2958 Flexible and powerful format based on Flattened Image Tree -- FIT (similar
2959 to Flattened Device Tree). It allows the use of images with multiple
2960 components (several kernels, ramdisks, etc.), with contents protected by
2961 SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory.
2967 Old image format is based on binary files which can be basically anything,
2968 preceded by a special header; see the definitions in include/image.h for
2969 details; basically, the header defines the following image properties:
2971 * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
2972 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
2973 LynxOS, pSOS, QNX, RTEMS, ARTOS;
2974 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, ARTOS, LynxOS).
2975 * Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86,
2976 IA64, MIPS, NIOS, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
2977 Currently supported: ARM, AVR32, Intel x86, MIPS, NIOS, PowerPC).
2978 * Compression Type (uncompressed, gzip, bzip2)
2984 The header is marked by a special Magic Number, and both the header
2985 and the data portions of the image are secured against corruption by
2992 Although U-Boot should support any OS or standalone application
2993 easily, the main focus has always been on Linux during the design of
2996 U-Boot includes many features that so far have been part of some
2997 special "boot loader" code within the Linux kernel. Also, any
2998 "initrd" images to be used are no longer part of one big Linux image;
2999 instead, kernel and "initrd" are separate images. This implementation
3000 serves several purposes:
3002 - the same features can be used for other OS or standalone
3003 applications (for instance: using compressed images to reduce the
3004 Flash memory footprint)
3006 - it becomes much easier to port new Linux kernel versions because
3007 lots of low-level, hardware dependent stuff are done by U-Boot
3009 - the same Linux kernel image can now be used with different "initrd"
3010 images; of course this also means that different kernel images can
3011 be run with the same "initrd". This makes testing easier (you don't
3012 have to build a new "zImage.initrd" Linux image when you just
3013 change a file in your "initrd"). Also, a field-upgrade of the
3014 software is easier now.
3020 Porting Linux to U-Boot based systems:
3021 ---------------------------------------
3023 U-Boot cannot save you from doing all the necessary modifications to
3024 configure the Linux device drivers for use with your target hardware
3025 (no, we don't intend to provide a full virtual machine interface to
3028 But now you can ignore ALL boot loader code (in arch/ppc/mbxboot).
3030 Just make sure your machine specific header file (for instance
3031 include/asm-ppc/tqm8xx.h) includes the same definition of the Board
3032 Information structure as we define in include/u-boot.h, and make
3033 sure that your definition of IMAP_ADDR uses the same value as your
3034 U-Boot configuration in CFG_IMMR.
3037 Configuring the Linux kernel:
3038 -----------------------------
3040 No specific requirements for U-Boot. Make sure you have some root
3041 device (initial ramdisk, NFS) for your target system.
3044 Building a Linux Image:
3045 -----------------------
3047 With U-Boot, "normal" build targets like "zImage" or "bzImage" are
3048 not used. If you use recent kernel source, a new build target
3049 "uImage" will exist which automatically builds an image usable by
3050 U-Boot. Most older kernels also have support for a "pImage" target,
3051 which was introduced for our predecessor project PPCBoot and uses a
3052 100% compatible format.
3061 The "uImage" build target uses a special tool (in 'tools/mkimage') to
3062 encapsulate a compressed Linux kernel image with header information,
3063 CRC32 checksum etc. for use with U-Boot. This is what we are doing:
3065 * build a standard "vmlinux" kernel image (in ELF binary format):
3067 * convert the kernel into a raw binary image:
3069 ${CROSS_COMPILE}-objcopy -O binary \
3070 -R .note -R .comment \
3071 -S vmlinux linux.bin
3073 * compress the binary image:
3077 * package compressed binary image for U-Boot:
3079 mkimage -A ppc -O linux -T kernel -C gzip \
3080 -a 0 -e 0 -n "Linux Kernel Image" \
3081 -d linux.bin.gz uImage
3084 The "mkimage" tool can also be used to create ramdisk images for use
3085 with U-Boot, either separated from the Linux kernel image, or
3086 combined into one file. "mkimage" encapsulates the images with a 64
3087 byte header containing information about target architecture,
3088 operating system, image type, compression method, entry points, time
3089 stamp, CRC32 checksums, etc.
3091 "mkimage" can be called in two ways: to verify existing images and
3092 print the header information, or to build new images.
3094 In the first form (with "-l" option) mkimage lists the information
3095 contained in the header of an existing U-Boot image; this includes
3096 checksum verification:
3098 tools/mkimage -l image
3099 -l ==> list image header information
3101 The second form (with "-d" option) is used to build a U-Boot image
3102 from a "data file" which is used as image payload:
3104 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
3105 -n name -d data_file image
3106 -A ==> set architecture to 'arch'
3107 -O ==> set operating system to 'os'
3108 -T ==> set image type to 'type'
3109 -C ==> set compression type 'comp'
3110 -a ==> set load address to 'addr' (hex)
3111 -e ==> set entry point to 'ep' (hex)
3112 -n ==> set image name to 'name'
3113 -d ==> use image data from 'datafile'
3115 Right now, all Linux kernels for PowerPC systems use the same load
3116 address (0x00000000), but the entry point address depends on the
3119 - 2.2.x kernels have the entry point at 0x0000000C,
3120 - 2.3.x and later kernels have the entry point at 0x00000000.
3122 So a typical call to build a U-Boot image would read:
3124 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
3125 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
3126 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux.gz \
3127 > examples/uImage.TQM850L
3128 Image Name: 2.4.4 kernel for TQM850L
3129 Created: Wed Jul 19 02:34:59 2000
3130 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3131 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
3132 Load Address: 0x00000000
3133 Entry Point: 0x00000000
3135 To verify the contents of the image (or check for corruption):
3137 -> tools/mkimage -l examples/uImage.TQM850L
3138 Image Name: 2.4.4 kernel for TQM850L
3139 Created: Wed Jul 19 02:34:59 2000
3140 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3141 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
3142 Load Address: 0x00000000
3143 Entry Point: 0x00000000
3145 NOTE: for embedded systems where boot time is critical you can trade
3146 speed for memory and install an UNCOMPRESSED image instead: this
3147 needs more space in Flash, but boots much faster since it does not
3148 need to be uncompressed:
3150 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux.gz
3151 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
3152 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
3153 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux \
3154 > examples/uImage.TQM850L-uncompressed
3155 Image Name: 2.4.4 kernel for TQM850L
3156 Created: Wed Jul 19 02:34:59 2000
3157 Image Type: PowerPC Linux Kernel Image (uncompressed)
3158 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
3159 Load Address: 0x00000000
3160 Entry Point: 0x00000000
3163 Similar you can build U-Boot images from a 'ramdisk.image.gz' file
3164 when your kernel is intended to use an initial ramdisk:
3166 -> tools/mkimage -n 'Simple Ramdisk Image' \
3167 > -A ppc -O linux -T ramdisk -C gzip \
3168 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
3169 Image Name: Simple Ramdisk Image
3170 Created: Wed Jan 12 14:01:50 2000
3171 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
3172 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
3173 Load Address: 0x00000000
3174 Entry Point: 0x00000000
3177 Installing a Linux Image:
3178 -------------------------
3180 To downloading a U-Boot image over the serial (console) interface,
3181 you must convert the image to S-Record format:
3183 objcopy -I binary -O srec examples/image examples/image.srec
3185 The 'objcopy' does not understand the information in the U-Boot
3186 image header, so the resulting S-Record file will be relative to
3187 address 0x00000000. To load it to a given address, you need to
3188 specify the target address as 'offset' parameter with the 'loads'
3191 Example: install the image to address 0x40100000 (which on the
3192 TQM8xxL is in the first Flash bank):
3194 => erase 40100000 401FFFFF
3200 ## Ready for S-Record download ...
3201 ~>examples/image.srec
3202 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
3204 15989 15990 15991 15992
3205 [file transfer complete]
3207 ## Start Addr = 0x00000000
3210 You can check the success of the download using the 'iminfo' command;
3211 this includes a checksum verification so you can be sure no data
3212 corruption happened:
3216 ## Checking Image at 40100000 ...
3217 Image Name: 2.2.13 for initrd on TQM850L
3218 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3219 Data Size: 335725 Bytes = 327 kB = 0 MB
3220 Load Address: 00000000
3221 Entry Point: 0000000c
3222 Verifying Checksum ... OK
3228 The "bootm" command is used to boot an application that is stored in
3229 memory (RAM or Flash). In case of a Linux kernel image, the contents
3230 of the "bootargs" environment variable is passed to the kernel as
3231 parameters. You can check and modify this variable using the
3232 "printenv" and "setenv" commands:
3235 => printenv bootargs
3236 bootargs=root=/dev/ram
3238 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
3240 => printenv bootargs
3241 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
3244 ## Booting Linux kernel at 40020000 ...
3245 Image Name: 2.2.13 for NFS on TQM850L
3246 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3247 Data Size: 381681 Bytes = 372 kB = 0 MB
3248 Load Address: 00000000
3249 Entry Point: 0000000c
3250 Verifying Checksum ... OK
3251 Uncompressing Kernel Image ... OK
3252 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
3253 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
3254 time_init: decrementer frequency = 187500000/60
3255 Calibrating delay loop... 49.77 BogoMIPS
3256 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
3259 If you want to boot a Linux kernel with initial ram disk, you pass
3260 the memory addresses of both the kernel and the initrd image (PPBCOOT
3261 format!) to the "bootm" command:
3263 => imi 40100000 40200000
3265 ## Checking Image at 40100000 ...
3266 Image Name: 2.2.13 for initrd on TQM850L
3267 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3268 Data Size: 335725 Bytes = 327 kB = 0 MB
3269 Load Address: 00000000
3270 Entry Point: 0000000c
3271 Verifying Checksum ... OK
3273 ## Checking Image at 40200000 ...
3274 Image Name: Simple Ramdisk Image
3275 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
3276 Data Size: 566530 Bytes = 553 kB = 0 MB
3277 Load Address: 00000000
3278 Entry Point: 00000000
3279 Verifying Checksum ... OK
3281 => bootm 40100000 40200000
3282 ## Booting Linux kernel at 40100000 ...
3283 Image Name: 2.2.13 for initrd on TQM850L
3284 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3285 Data Size: 335725 Bytes = 327 kB = 0 MB
3286 Load Address: 00000000
3287 Entry Point: 0000000c
3288 Verifying Checksum ... OK
3289 Uncompressing Kernel Image ... OK
3290 ## Loading RAMDisk Image at 40200000 ...
3291 Image Name: Simple Ramdisk Image
3292 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
3293 Data Size: 566530 Bytes = 553 kB = 0 MB
3294 Load Address: 00000000
3295 Entry Point: 00000000
3296 Verifying Checksum ... OK
3297 Loading Ramdisk ... OK
3298 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
3299 Boot arguments: root=/dev/ram
3300 time_init: decrementer frequency = 187500000/60
3301 Calibrating delay loop... 49.77 BogoMIPS
3303 RAMDISK: Compressed image found at block 0
3304 VFS: Mounted root (ext2 filesystem).
3308 Boot Linux and pass a flat device tree:
3311 First, U-Boot must be compiled with the appropriate defines. See the section
3312 titled "Linux Kernel Interface" above for a more in depth explanation. The
3313 following is an example of how to start a kernel and pass an updated
3319 oft=oftrees/mpc8540ads.dtb
3320 => tftp $oftaddr $oft
3321 Speed: 1000, full duplex
3323 TFTP from server 192.168.1.1; our IP address is 192.168.1.101
3324 Filename 'oftrees/mpc8540ads.dtb'.
3325 Load address: 0x300000
3328 Bytes transferred = 4106 (100a hex)
3329 => tftp $loadaddr $bootfile
3330 Speed: 1000, full duplex
3332 TFTP from server 192.168.1.1; our IP address is 192.168.1.2
3334 Load address: 0x200000
3335 Loading:############
3337 Bytes transferred = 1029407 (fb51f hex)
3342 => bootm $loadaddr - $oftaddr
3343 ## Booting image at 00200000 ...
3344 Image Name: Linux-2.6.17-dirty
3345 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3346 Data Size: 1029343 Bytes = 1005.2 kB
3347 Load Address: 00000000
3348 Entry Point: 00000000
3349 Verifying Checksum ... OK
3350 Uncompressing Kernel Image ... OK
3351 Booting using flat device tree at 0x300000
3352 Using MPC85xx ADS machine description
3353 Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb
3357 More About U-Boot Image Types:
3358 ------------------------------
3360 U-Boot supports the following image types:
3362 "Standalone Programs" are directly runnable in the environment
3363 provided by U-Boot; it is expected that (if they behave
3364 well) you can continue to work in U-Boot after return from
3365 the Standalone Program.
3366 "OS Kernel Images" are usually images of some Embedded OS which
3367 will take over control completely. Usually these programs
3368 will install their own set of exception handlers, device
3369 drivers, set up the MMU, etc. - this means, that you cannot
3370 expect to re-enter U-Boot except by resetting the CPU.
3371 "RAMDisk Images" are more or less just data blocks, and their
3372 parameters (address, size) are passed to an OS kernel that is
3374 "Multi-File Images" contain several images, typically an OS
3375 (Linux) kernel image and one or more data images like
3376 RAMDisks. This construct is useful for instance when you want
3377 to boot over the network using BOOTP etc., where the boot
3378 server provides just a single image file, but you want to get
3379 for instance an OS kernel and a RAMDisk image.
3381 "Multi-File Images" start with a list of image sizes, each
3382 image size (in bytes) specified by an "uint32_t" in network
3383 byte order. This list is terminated by an "(uint32_t)0".
3384 Immediately after the terminating 0 follow the images, one by
3385 one, all aligned on "uint32_t" boundaries (size rounded up to
3386 a multiple of 4 bytes).
3388 "Firmware Images" are binary images containing firmware (like
3389 U-Boot or FPGA images) which usually will be programmed to
3392 "Script files" are command sequences that will be executed by
3393 U-Boot's command interpreter; this feature is especially
3394 useful when you configure U-Boot to use a real shell (hush)
3395 as command interpreter.
3401 One of the features of U-Boot is that you can dynamically load and
3402 run "standalone" applications, which can use some resources of
3403 U-Boot like console I/O functions or interrupt services.
3405 Two simple examples are included with the sources:
3410 'examples/hello_world.c' contains a small "Hello World" Demo
3411 application; it is automatically compiled when you build U-Boot.
3412 It's configured to run at address 0x00040004, so you can play with it
3416 ## Ready for S-Record download ...
3417 ~>examples/hello_world.srec
3418 1 2 3 4 5 6 7 8 9 10 11 ...
3419 [file transfer complete]
3421 ## Start Addr = 0x00040004
3423 => go 40004 Hello World! This is a test.
3424 ## Starting application at 0x00040004 ...
3435 Hit any key to exit ...
3437 ## Application terminated, rc = 0x0
3439 Another example, which demonstrates how to register a CPM interrupt
3440 handler with the U-Boot code, can be found in 'examples/timer.c'.
3441 Here, a CPM timer is set up to generate an interrupt every second.
3442 The interrupt service routine is trivial, just printing a '.'
3443 character, but this is just a demo program. The application can be
3444 controlled by the following keys:
3446 ? - print current values og the CPM Timer registers
3447 b - enable interrupts and start timer
3448 e - stop timer and disable interrupts
3449 q - quit application
3452 ## Ready for S-Record download ...
3453 ~>examples/timer.srec
3454 1 2 3 4 5 6 7 8 9 10 11 ...
3455 [file transfer complete]
3457 ## Start Addr = 0x00040004
3460 ## Starting application at 0x00040004 ...
3463 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
3466 [q, b, e, ?] Set interval 1000000 us
3469 [q, b, e, ?] ........
3470 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
3473 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
3476 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
3479 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
3481 [q, b, e, ?] ...Stopping timer
3483 [q, b, e, ?] ## Application terminated, rc = 0x0
3489 Over time, many people have reported problems when trying to use the
3490 "minicom" terminal emulation program for serial download. I (wd)
3491 consider minicom to be broken, and recommend not to use it. Under
3492 Unix, I recommend to use C-Kermit for general purpose use (and
3493 especially for kermit binary protocol download ("loadb" command), and
3494 use "cu" for S-Record download ("loads" command).
3496 Nevertheless, if you absolutely want to use it try adding this
3497 configuration to your "File transfer protocols" section:
3499 Name Program Name U/D FullScr IO-Red. Multi
3500 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
3501 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
3507 Starting at version 0.9.2, U-Boot supports NetBSD both as host
3508 (build U-Boot) and target system (boots NetBSD/mpc8xx).
3510 Building requires a cross environment; it is known to work on
3511 NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
3512 need gmake since the Makefiles are not compatible with BSD make).
3513 Note that the cross-powerpc package does not install include files;
3514 attempting to build U-Boot will fail because <machine/ansi.h> is
3515 missing. This file has to be installed and patched manually:
3517 # cd /usr/pkg/cross/powerpc-netbsd/include
3519 # ln -s powerpc machine
3520 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
3521 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
3523 Native builds *don't* work due to incompatibilities between native
3524 and U-Boot include files.
3526 Booting assumes that (the first part of) the image booted is a
3527 stage-2 loader which in turn loads and then invokes the kernel
3528 proper. Loader sources will eventually appear in the NetBSD source
3529 tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
3530 meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz
3533 Implementation Internals:
3534 =========================
3536 The following is not intended to be a complete description of every
3537 implementation detail. However, it should help to understand the
3538 inner workings of U-Boot and make it easier to port it to custom
3542 Initial Stack, Global Data:
3543 ---------------------------
3545 The implementation of U-Boot is complicated by the fact that U-Boot
3546 starts running out of ROM (flash memory), usually without access to
3547 system RAM (because the memory controller is not initialized yet).
3548 This means that we don't have writable Data or BSS segments, and BSS
3549 is not initialized as zero. To be able to get a C environment working
3550 at all, we have to allocate at least a minimal stack. Implementation
3551 options for this are defined and restricted by the CPU used: Some CPU
3552 models provide on-chip memory (like the IMMR area on MPC8xx and
3553 MPC826x processors), on others (parts of) the data cache can be
3554 locked as (mis-) used as memory, etc.
3556 Chris Hallinan posted a good summary of these issues to the
3557 u-boot-users mailing list:
3559 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
3560 From: "Chris Hallinan" <clh@net1plus.com>
3561 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
3564 Correct me if I'm wrong, folks, but the way I understand it
3565 is this: Using DCACHE as initial RAM for Stack, etc, does not
3566 require any physical RAM backing up the cache. The cleverness
3567 is that the cache is being used as a temporary supply of
3568 necessary storage before the SDRAM controller is setup. It's
3569 beyond the scope of this list to expain the details, but you
3570 can see how this works by studying the cache architecture and
3571 operation in the architecture and processor-specific manuals.
3573 OCM is On Chip Memory, which I believe the 405GP has 4K. It
3574 is another option for the system designer to use as an
3575 initial stack/ram area prior to SDRAM being available. Either
3576 option should work for you. Using CS 4 should be fine if your
3577 board designers haven't used it for something that would
3578 cause you grief during the initial boot! It is frequently not
3581 CFG_INIT_RAM_ADDR should be somewhere that won't interfere
3582 with your processor/board/system design. The default value
3583 you will find in any recent u-boot distribution in
3584 walnut.h should work for you. I'd set it to a value larger
3585 than your SDRAM module. If you have a 64MB SDRAM module, set
3586 it above 400_0000. Just make sure your board has no resources
3587 that are supposed to respond to that address! That code in
3588 start.S has been around a while and should work as is when
3589 you get the config right.
3594 It is essential to remember this, since it has some impact on the C
3595 code for the initialization procedures:
3597 * Initialized global data (data segment) is read-only. Do not attempt
3600 * Do not use any unitialized global data (or implicitely initialized
3601 as zero data - BSS segment) at all - this is undefined, initiali-
3602 zation is performed later (when relocating to RAM).
3604 * Stack space is very limited. Avoid big data buffers or things like
3607 Having only the stack as writable memory limits means we cannot use
3608 normal global data to share information beween the code. But it
3609 turned out that the implementation of U-Boot can be greatly
3610 simplified by making a global data structure (gd_t) available to all
3611 functions. We could pass a pointer to this data as argument to _all_
3612 functions, but this would bloat the code. Instead we use a feature of
3613 the GCC compiler (Global Register Variables) to share the data: we
3614 place a pointer (gd) to the global data into a register which we
3615 reserve for this purpose.
3617 When choosing a register for such a purpose we are restricted by the
3618 relevant (E)ABI specifications for the current architecture, and by
3619 GCC's implementation.
3621 For PowerPC, the following registers have specific use:
3623 R2: reserved for system use
3624 R3-R4: parameter passing and return values
3625 R5-R10: parameter passing
3626 R13: small data area pointer
3630 (U-Boot also uses R14 as internal GOT pointer.)
3632 ==> U-Boot will use R2 to hold a pointer to the global data
3634 Note: on PPC, we could use a static initializer (since the
3635 address of the global data structure is known at compile time),
3636 but it turned out that reserving a register results in somewhat
3637 smaller code - although the code savings are not that big (on
3638 average for all boards 752 bytes for the whole U-Boot image,
3639 624 text + 127 data).
3641 On Blackfin, the normal C ABI (except for P5) is followed as documented here:
3642 http://docs.blackfin.uclinux.org/doku.php?id=application_binary_interface
3644 ==> U-Boot will use P5 to hold a pointer to the global data
3646 On ARM, the following registers are used:
3648 R0: function argument word/integer result
3649 R1-R3: function argument word
3651 R10: stack limit (used only if stack checking if enabled)
3652 R11: argument (frame) pointer
3653 R12: temporary workspace
3656 R15: program counter
3658 ==> U-Boot will use R8 to hold a pointer to the global data
3660 NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope,
3661 or current versions of GCC may "optimize" the code too much.
3666 U-Boot runs in system state and uses physical addresses, i.e. the
3667 MMU is not used either for address mapping nor for memory protection.
3669 The available memory is mapped to fixed addresses using the memory
3670 controller. In this process, a contiguous block is formed for each
3671 memory type (Flash, SDRAM, SRAM), even when it consists of several
3672 physical memory banks.
3674 U-Boot is installed in the first 128 kB of the first Flash bank (on
3675 TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
3676 booting and sizing and initializing DRAM, the code relocates itself
3677 to the upper end of DRAM. Immediately below the U-Boot code some
3678 memory is reserved for use by malloc() [see CFG_MALLOC_LEN
3679 configuration setting]. Below that, a structure with global Board
3680 Info data is placed, followed by the stack (growing downward).
3682 Additionally, some exception handler code is copied to the low 8 kB
3683 of DRAM (0x00000000 ... 0x00001FFF).
3685 So a typical memory configuration with 16 MB of DRAM could look like
3688 0x0000 0000 Exception Vector code
3691 0x0000 2000 Free for Application Use
3697 0x00FB FF20 Monitor Stack (Growing downward)
3698 0x00FB FFAC Board Info Data and permanent copy of global data
3699 0x00FC 0000 Malloc Arena
3702 0x00FE 0000 RAM Copy of Monitor Code
3703 ... eventually: LCD or video framebuffer
3704 ... eventually: pRAM (Protected RAM - unchanged by reset)
3705 0x00FF FFFF [End of RAM]
3708 System Initialization:
3709 ----------------------
3711 In the reset configuration, U-Boot starts at the reset entry point
3712 (on most PowerPC systens at address 0x00000100). Because of the reset
3713 configuration for CS0# this is a mirror of the onboard Flash memory.
3714 To be able to re-map memory U-Boot then jumps to its link address.
3715 To be able to implement the initialization code in C, a (small!)
3716 initial stack is set up in the internal Dual Ported RAM (in case CPUs
3717 which provide such a feature like MPC8xx or MPC8260), or in a locked
3718 part of the data cache. After that, U-Boot initializes the CPU core,
3719 the caches and the SIU.
3721 Next, all (potentially) available memory banks are mapped using a
3722 preliminary mapping. For example, we put them on 512 MB boundaries
3723 (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
3724 on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
3725 programmed for SDRAM access. Using the temporary configuration, a
3726 simple memory test is run that determines the size of the SDRAM
3729 When there is more than one SDRAM bank, and the banks are of
3730 different size, the largest is mapped first. For equal size, the first
3731 bank (CS2#) is mapped first. The first mapping is always for address
3732 0x00000000, with any additional banks following immediately to create
3733 contiguous memory starting from 0.
3735 Then, the monitor installs itself at the upper end of the SDRAM area
3736 and allocates memory for use by malloc() and for the global Board
3737 Info data; also, the exception vector code is copied to the low RAM
3738 pages, and the final stack is set up.
3740 Only after this relocation will you have a "normal" C environment;
3741 until that you are restricted in several ways, mostly because you are
3742 running from ROM, and because the code will have to be relocated to a
3746 U-Boot Porting Guide:
3747 ----------------------
3749 [Based on messages by Jerry Van Baren in the U-Boot-Users mailing
3753 int main (int argc, char *argv[])
3755 sighandler_t no_more_time;
3757 signal (SIGALRM, no_more_time);
3758 alarm (PROJECT_DEADLINE - toSec (3 * WEEK));
3760 if (available_money > available_manpower) {
3761 pay consultant to port U-Boot;
3765 Download latest U-Boot source;
3767 Subscribe to u-boot-users mailing list;
3770 email ("Hi, I am new to U-Boot, how do I get started?");
3774 Read the README file in the top level directory;
3775 Read http://www.denx.de/twiki/bin/view/DULG/Manual ;
3776 Read the source, Luke;
3779 if (available_money > toLocalCurrency ($2500)) {
3782 Add a lot of aggravation and time;
3785 Create your own board support subdirectory;
3787 Create your own board config file;
3791 Add / modify source code;
3795 email ("Hi, I am having problems...");
3797 Send patch file to Wolfgang;
3802 void no_more_time (int sig)
3811 All contributions to U-Boot should conform to the Linux kernel
3812 coding style; see the file "Documentation/CodingStyle" and the script
3813 "scripts/Lindent" in your Linux kernel source directory. In sources
3814 originating from U-Boot a style corresponding to "Lindent -pcs" (adding
3815 spaces before parameters to function calls) is actually used.
3817 Source files originating from a different project (for example the
3818 MTD subsystem) are generally exempt from these guidelines and are not
3819 reformated to ease subsequent migration to newer versions of those
3822 Please note that U-Boot is implemented in C (and to some small parts in
3823 Assembler); no C++ is used, so please do not use C++ style comments (//)
3826 Please also stick to the following formatting rules:
3827 - remove any trailing white space
3828 - use TAB characters for indentation, not spaces
3829 - make sure NOT to use DOS '\r\n' line feeds
3830 - do not add more than 2 empty lines to source files
3831 - do not add trailing empty lines to source files
3833 Submissions which do not conform to the standards may be returned
3834 with a request to reformat the changes.
3840 Since the number of patches for U-Boot is growing, we need to
3841 establish some rules. Submissions which do not conform to these rules
3842 may be rejected, even when they contain important and valuable stuff.
3844 Patches shall be sent to the u-boot-users mailing list.
3846 Please see http://www.denx.de/wiki/UBoot/Patches for details.
3848 When you send a patch, please include the following information with
3851 * For bug fixes: a description of the bug and how your patch fixes
3852 this bug. Please try to include a way of demonstrating that the
3853 patch actually fixes something.
3855 * For new features: a description of the feature and your
3858 * A CHANGELOG entry as plaintext (separate from the patch)
3860 * For major contributions, your entry to the CREDITS file
3862 * When you add support for a new board, don't forget to add this
3863 board to the MAKEALL script, too.
3865 * If your patch adds new configuration options, don't forget to
3866 document these in the README file.
3868 * The patch itself. If you are using git (which is *strongly*
3869 recommended) you can easily generate the patch using the
3870 "git-format-patch". If you then use "git-send-email" to send it to
3871 the U-Boot mailing list, you will avoid most of the common problems
3872 with some other mail clients.
3874 If you cannot use git, use "diff -purN OLD NEW". If your version of
3875 diff does not support these options, then get the latest version of
3878 The current directory when running this command shall be the parent
3879 directory of the U-Boot source tree (i. e. please make sure that
3880 your patch includes sufficient directory information for the
3883 We prefer patches as plain text. MIME attachments are discouraged,
3884 and compressed attachments must not be used.
3886 * If one logical set of modifications affects or creates several
3887 files, all these changes shall be submitted in a SINGLE patch file.
3889 * Changesets that contain different, unrelated modifications shall be
3890 submitted as SEPARATE patches, one patch per changeset.
3895 * Before sending the patch, run the MAKEALL script on your patched
3896 source tree and make sure that no errors or warnings are reported
3897 for any of the boards.
3899 * Keep your modifications to the necessary minimum: A patch
3900 containing several unrelated changes or arbitrary reformats will be
3901 returned with a request to re-formatting / split it.
3903 * If you modify existing code, make sure that your new code does not
3904 add to the memory footprint of the code ;-) Small is beautiful!
3905 When adding new features, these should compile conditionally only
3906 (using #ifdef), and the resulting code with the new feature
3907 disabled must not need more memory than the old code without your
3910 * Remember that there is a size limit of 40 kB per message on the
3911 u-boot-users mailing list. Bigger patches will be moderated. If
3912 they are reasonable and not bigger than 100 kB, they will be
3913 acknowledged. Even bigger patches should be avoided.
projects / karo-tx-uboot.git / blob