2 # (C) Copyright 2000 - 2009
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@lists.denx.de>. There is also an archive of previous traffic
64 on the mailing list - please search the archive before asking FAQ's.
65 Please see http://lists.denx.de/pipermail/u-boot and
66 http://dir.gmane.org/gmane.comp.boot-loaders.u-boot
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. Official 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/U-Boot
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 - api Machine/arch independent API for external apps
142 - board Board dependent files
143 - common Misc architecture independent functions
144 - cpu CPU specific files
145 - 74xx_7xx Files specific to Freescale MPC74xx and 7xx CPUs
146 - arm720t Files specific to ARM 720 CPUs
147 - arm920t Files specific to ARM 920 CPUs
148 - at91rm9200 Files specific to Atmel AT91RM9200 CPU
149 - imx Files specific to Freescale MC9328 i.MX CPUs
150 - s3c24x0 Files specific to Samsung S3C24X0 CPUs
151 - arm925t Files specific to ARM 925 CPUs
152 - arm926ejs Files specific to ARM 926 CPUs
153 - arm1136 Files specific to ARM 1136 CPUs
154 - at32ap Files specific to Atmel AVR32 AP CPUs
155 - blackfin Files specific to Analog Devices Blackfin CPUs
156 - i386 Files specific to i386 CPUs
157 - ixp Files specific to Intel XScale IXP CPUs
158 - leon2 Files specific to Gaisler LEON2 SPARC CPU
159 - leon3 Files specific to Gaisler LEON3 SPARC CPU
160 - mcf52x2 Files specific to Freescale ColdFire MCF52x2 CPUs
161 - mcf5227x Files specific to Freescale ColdFire MCF5227x CPUs
162 - mcf532x Files specific to Freescale ColdFire MCF5329 CPUs
163 - mcf5445x Files specific to Freescale ColdFire MCF5445x CPUs
164 - mcf547x_8x Files specific to Freescale ColdFire MCF547x_8x CPUs
165 - mips Files specific to MIPS CPUs
166 - mpc5xx Files specific to Freescale MPC5xx CPUs
167 - mpc5xxx Files specific to Freescale MPC5xxx CPUs
168 - mpc8xx Files specific to Freescale MPC8xx CPUs
169 - mpc8220 Files specific to Freescale MPC8220 CPUs
170 - mpc824x Files specific to Freescale MPC824x CPUs
171 - mpc8260 Files specific to Freescale MPC8260 CPUs
172 - mpc85xx Files specific to Freescale MPC85xx CPUs
173 - nios Files specific to Altera NIOS CPUs
174 - nios2 Files specific to Altera Nios-II CPUs
175 - ppc4xx Files specific to AMCC PowerPC 4xx CPUs
176 - pxa Files specific to Intel XScale PXA CPUs
177 - s3c44b0 Files specific to Samsung S3C44B0 CPUs
178 - sa1100 Files specific to Intel StrongARM SA1100 CPUs
179 - disk Code for disk drive partition handling
180 - doc Documentation (don't expect too much)
181 - drivers Commonly used device drivers
182 - examples Example code for standalone applications, etc.
183 - fs Filesystem code (cramfs, ext2, jffs2, etc.)
184 - include Header Files
185 - lib_arm Files generic to ARM architecture
186 - lib_avr32 Files generic to AVR32 architecture
187 - lib_blackfin Files generic to Blackfin architecture
188 - lib_generic Files generic to all architectures
189 - lib_i386 Files generic to i386 architecture
190 - lib_m68k Files generic to m68k architecture
191 - lib_microblaze Files generic to microblaze architecture
192 - lib_mips Files generic to MIPS architecture
193 - lib_nios Files generic to NIOS architecture
194 - lib_nios2 Files generic to NIOS2 architecture
195 - lib_ppc Files generic to PowerPC architecture
196 - lib_sh Files generic to SH architecture
197 - lib_sparc Files generic to SPARC architecture
198 - libfdt Library files to support flattened device trees
199 - net Networking code
200 - post Power On Self Test
201 - rtc Real Time Clock drivers
202 - tools Tools to build S-Record or U-Boot images, etc.
204 Software Configuration:
205 =======================
207 Configuration is usually done using C preprocessor defines; the
208 rationale behind that is to avoid dead code whenever possible.
210 There are two classes of configuration variables:
212 * Configuration _OPTIONS_:
213 These are selectable by the user and have names beginning with
216 * Configuration _SETTINGS_:
217 These depend on the hardware etc. and should not be meddled with if
218 you don't know what you're doing; they have names beginning with
221 Later we will add a configuration tool - probably similar to or even
222 identical to what's used for the Linux kernel. Right now, we have to
223 do the configuration by hand, which means creating some symbolic
224 links and editing some configuration files. We use the TQM8xxL boards
228 Selection of Processor Architecture and Board Type:
229 ---------------------------------------------------
231 For all supported boards there are ready-to-use default
232 configurations available; just type "make <board_name>_config".
234 Example: For a TQM823L module type:
239 For the Cogent platform, you need to specify the CPU type as well;
240 e.g. "make cogent_mpc8xx_config". And also configure the cogent
241 directory according to the instructions in cogent/README.
244 Configuration Options:
245 ----------------------
247 Configuration depends on the combination of board and CPU type; all
248 such information is kept in a configuration file
249 "include/configs/<board_name>.h".
251 Example: For a TQM823L module, all configuration settings are in
252 "include/configs/TQM823L.h".
255 Many of the options are named exactly as the corresponding Linux
256 kernel configuration options. The intention is to make it easier to
257 build a config tool - later.
260 The following options need to be configured:
262 - CPU Type: Define exactly one, e.g. CONFIG_MPC85XX.
264 - Board Type: Define exactly one, e.g. CONFIG_MPC8540ADS.
266 - CPU Daughterboard Type: (if CONFIG_ATSTK1000 is defined)
267 Define exactly one, e.g. CONFIG_ATSTK1002
269 - CPU Module Type: (if CONFIG_COGENT is defined)
270 Define exactly one of
272 --- FIXME --- not tested yet:
273 CONFIG_CMA286_60, CONFIG_CMA286_21, CONFIG_CMA286_60P,
274 CONFIG_CMA287_23, CONFIG_CMA287_50
276 - Motherboard Type: (if CONFIG_COGENT is defined)
277 Define exactly one of
278 CONFIG_CMA101, CONFIG_CMA102
280 - Motherboard I/O Modules: (if CONFIG_COGENT is defined)
281 Define one or more of
284 - Motherboard Options: (if CONFIG_CMA101 or CONFIG_CMA102 are defined)
285 Define one or more of
286 CONFIG_LCD_HEARTBEAT - update a character position on
287 the LCD display every second with
290 - Board flavour: (if CONFIG_MPC8260ADS is defined)
293 CONFIG_SYS_8260ADS - original MPC8260ADS
294 CONFIG_SYS_8266ADS - MPC8266ADS
295 CONFIG_SYS_PQ2FADS - PQ2FADS-ZU or PQ2FADS-VR
296 CONFIG_SYS_8272ADS - MPC8272ADS
298 - MPC824X Family Member (if CONFIG_MPC824X is defined)
299 Define exactly one of
300 CONFIG_MPC8240, CONFIG_MPC8245
302 - 8xx CPU Options: (if using an MPC8xx CPU)
303 CONFIG_8xx_GCLK_FREQ - deprecated: CPU clock if
304 get_gclk_freq() cannot work
305 e.g. if there is no 32KHz
306 reference PIT/RTC clock
307 CONFIG_8xx_OSCLK - PLL input clock (either EXTCLK
310 - 859/866/885 CPU options: (if using a MPC859 or MPC866 or MPC885 CPU):
311 CONFIG_SYS_8xx_CPUCLK_MIN
312 CONFIG_SYS_8xx_CPUCLK_MAX
313 CONFIG_8xx_CPUCLK_DEFAULT
314 See doc/README.MPC866
316 CONFIG_SYS_MEASURE_CPUCLK
318 Define this to measure the actual CPU clock instead
319 of relying on the correctness of the configured
320 values. Mostly useful for board bringup to make sure
321 the PLL is locked at the intended frequency. Note
322 that this requires a (stable) reference clock (32 kHz
323 RTC clock or CONFIG_SYS_8XX_XIN)
325 CONFIG_SYS_DELAYED_ICACHE
327 Define this option if you want to enable the
328 ICache only when Code runs from RAM.
330 - Intel Monahans options:
331 CONFIG_SYS_MONAHANS_RUN_MODE_OSC_RATIO
333 Defines the Monahans run mode to oscillator
334 ratio. Valid values are 8, 16, 24, 31. The core
335 frequency is this value multiplied by 13 MHz.
337 CONFIG_SYS_MONAHANS_TURBO_RUN_MODE_RATIO
339 Defines the Monahans turbo mode to oscillator
340 ratio. Valid values are 1 (default if undefined) and
341 2. The core frequency as calculated above is multiplied
344 - Linux Kernel Interface:
347 U-Boot stores all clock information in Hz
348 internally. For binary compatibility with older Linux
349 kernels (which expect the clocks passed in the
350 bd_info data to be in MHz) the environment variable
351 "clocks_in_mhz" can be defined so that U-Boot
352 converts clock data to MHZ before passing it to the
354 When CONFIG_CLOCKS_IN_MHZ is defined, a definition of
355 "clocks_in_mhz=1" is automatically included in the
358 CONFIG_MEMSIZE_IN_BYTES [relevant for MIPS only]
360 When transferring memsize parameter to linux, some versions
361 expect it to be in bytes, others in MB.
362 Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes.
366 New kernel versions are expecting firmware settings to be
367 passed using flattened device trees (based on open firmware
371 * New libfdt-based support
372 * Adds the "fdt" command
373 * The bootm command automatically updates the fdt
375 OF_CPU - The proper name of the cpus node (only required for
376 MPC512X and MPC5xxx based boards).
377 OF_SOC - The proper name of the soc node (only required for
378 MPC512X and MPC5xxx based boards).
379 OF_TBCLK - The timebase frequency.
380 OF_STDOUT_PATH - The path to the console device
382 boards with QUICC Engines require OF_QE to set UCC MAC
385 CONFIG_OF_BOARD_SETUP
387 Board code has addition modification that it wants to make
388 to the flat device tree before handing it off to the kernel
392 This define fills in the correct boot CPU in the boot
393 param header, the default value is zero if undefined.
397 U-Boot can detect if an IDE device is present or not.
398 If not, and this new config option is activated, U-Boot
399 removes the ATA node from the DTS before booting Linux,
400 so the Linux IDE driver does not probe the device and
401 crash. This is needed for buggy hardware (uc101) where
402 no pull down resistor is connected to the signal IDE5V_DD7.
404 - vxWorks boot parameters:
406 bootvx constructs a valid bootline using the following
407 environments variables: bootfile, ipaddr, serverip, hostname.
408 It loads the vxWorks image pointed bootfile.
410 CONFIG_SYS_VXWORKS_BOOT_DEVICE - The vxworks device name
411 CONFIG_SYS_VXWORKS_MAC_PTR - Ethernet 6 byte MA -address
412 CONFIG_SYS_VXWORKS_SERVERNAME - Name of the server
413 CONFIG_SYS_VXWORKS_BOOT_ADDR - Address of boot parameters
415 CONFIG_SYS_VXWORKS_ADD_PARAMS
417 Add it at the end of the bootline. E.g "u=username pw=secret"
419 Note: If a "bootargs" environment is defined, it will overwride
420 the defaults discussed just above.
425 Define this if you want support for Amba PrimeCell PL010 UARTs.
429 Define this if you want support for Amba PrimeCell PL011 UARTs.
433 If you have Amba PrimeCell PL011 UARTs, set this variable to
434 the clock speed of the UARTs.
438 If you have Amba PrimeCell PL010 or PL011 UARTs on your board,
439 define this to a list of base addresses for each (supported)
440 port. See e.g. include/configs/versatile.h
444 Depending on board, define exactly one serial port
445 (like CONFIG_8xx_CONS_SMC1, CONFIG_8xx_CONS_SMC2,
446 CONFIG_8xx_CONS_SCC1, ...), or switch off the serial
447 console by defining CONFIG_8xx_CONS_NONE
449 Note: if CONFIG_8xx_CONS_NONE is defined, the serial
450 port routines must be defined elsewhere
451 (i.e. serial_init(), serial_getc(), ...)
454 Enables console device for a color framebuffer. Needs following
455 defines (cf. smiLynxEM, i8042, board/eltec/bab7xx)
456 VIDEO_FB_LITTLE_ENDIAN graphic memory organisation
458 VIDEO_HW_RECTFILL graphic chip supports
461 VIDEO_HW_BITBLT graphic chip supports
462 bit-blit (cf. smiLynxEM)
463 VIDEO_VISIBLE_COLS visible pixel columns
465 VIDEO_VISIBLE_ROWS visible pixel rows
466 VIDEO_PIXEL_SIZE bytes per pixel
467 VIDEO_DATA_FORMAT graphic data format
468 (0-5, cf. cfb_console.c)
469 VIDEO_FB_ADRS framebuffer address
470 VIDEO_KBD_INIT_FCT keyboard int fct
471 (i.e. i8042_kbd_init())
472 VIDEO_TSTC_FCT test char fct
474 VIDEO_GETC_FCT get char fct
476 CONFIG_CONSOLE_CURSOR cursor drawing on/off
477 (requires blink timer
479 CONFIG_SYS_CONSOLE_BLINK_COUNT blink interval (cf. i8042.c)
480 CONFIG_CONSOLE_TIME display time/date info in
482 (requires CONFIG_CMD_DATE)
483 CONFIG_VIDEO_LOGO display Linux logo in
485 CONFIG_VIDEO_BMP_LOGO use bmp_logo.h instead of
486 linux_logo.h for logo.
487 Requires CONFIG_VIDEO_LOGO
488 CONFIG_CONSOLE_EXTRA_INFO
489 additional board info beside
492 When CONFIG_CFB_CONSOLE is defined, video console is
493 default i/o. Serial console can be forced with
494 environment 'console=serial'.
496 When CONFIG_SILENT_CONSOLE is defined, all console
497 messages (by U-Boot and Linux!) can be silenced with
498 the "silent" environment variable. See
499 doc/README.silent for more information.
502 CONFIG_BAUDRATE - in bps
503 Select one of the baudrates listed in
504 CONFIG_SYS_BAUDRATE_TABLE, see below.
505 CONFIG_SYS_BRGCLK_PRESCALE, baudrate prescale
507 - Console Rx buffer length
508 With CONFIG_SYS_SMC_RXBUFLEN it is possible to define
509 the maximum receive buffer length for the SMC.
510 This option is actual only for 82xx and 8xx possible.
511 If using CONFIG_SYS_SMC_RXBUFLEN also CONFIG_SYS_MAXIDLE
512 must be defined, to setup the maximum idle timeout for
515 - Interrupt driven serial port input:
516 CONFIG_SERIAL_SOFTWARE_FIFO
519 Use an interrupt handler for receiving data on the
520 serial port. It also enables using hardware handshake
521 (RTS/CTS) and UART's built-in FIFO. Set the number of
522 bytes the interrupt driven input buffer should have.
524 Leave undefined to disable this feature, including
525 disable the buffer and hardware handshake.
527 - Console UART Number:
531 If defined internal UART1 (and not UART0) is used
532 as default U-Boot console.
534 - Boot Delay: CONFIG_BOOTDELAY - in seconds
535 Delay before automatically booting the default image;
536 set to -1 to disable autoboot.
538 See doc/README.autoboot for these options that
539 work with CONFIG_BOOTDELAY. None are required.
540 CONFIG_BOOT_RETRY_TIME
541 CONFIG_BOOT_RETRY_MIN
542 CONFIG_AUTOBOOT_KEYED
543 CONFIG_AUTOBOOT_PROMPT
544 CONFIG_AUTOBOOT_DELAY_STR
545 CONFIG_AUTOBOOT_STOP_STR
546 CONFIG_AUTOBOOT_DELAY_STR2
547 CONFIG_AUTOBOOT_STOP_STR2
548 CONFIG_ZERO_BOOTDELAY_CHECK
549 CONFIG_RESET_TO_RETRY
553 Only needed when CONFIG_BOOTDELAY is enabled;
554 define a command string that is automatically executed
555 when no character is read on the console interface
556 within "Boot Delay" after reset.
559 This can be used to pass arguments to the bootm
560 command. The value of CONFIG_BOOTARGS goes into the
561 environment value "bootargs".
563 CONFIG_RAMBOOT and CONFIG_NFSBOOT
564 The value of these goes into the environment as
565 "ramboot" and "nfsboot" respectively, and can be used
566 as a convenience, when switching between booting from
572 When this option is #defined, the existence of the
573 environment variable "preboot" will be checked
574 immediately before starting the CONFIG_BOOTDELAY
575 countdown and/or running the auto-boot command resp.
576 entering interactive mode.
578 This feature is especially useful when "preboot" is
579 automatically generated or modified. For an example
580 see the LWMON board specific code: here "preboot" is
581 modified when the user holds down a certain
582 combination of keys on the (special) keyboard when
585 - Serial Download Echo Mode:
587 If defined to 1, all characters received during a
588 serial download (using the "loads" command) are
589 echoed back. This might be needed by some terminal
590 emulations (like "cu"), but may as well just take
591 time on others. This setting #define's the initial
592 value of the "loads_echo" environment variable.
594 - Kgdb Serial Baudrate: (if CONFIG_CMD_KGDB is defined)
596 Select one of the baudrates listed in
597 CONFIG_SYS_BAUDRATE_TABLE, see below.
600 Monitor commands can be included or excluded
601 from the build by using the #include files
602 "config_cmd_all.h" and #undef'ing unwanted
603 commands, or using "config_cmd_default.h"
604 and augmenting with additional #define's
607 The default command configuration includes all commands
608 except those marked below with a "*".
610 CONFIG_CMD_ASKENV * ask for env variable
611 CONFIG_CMD_BDI bdinfo
612 CONFIG_CMD_BEDBUG * Include BedBug Debugger
613 CONFIG_CMD_BMP * BMP support
614 CONFIG_CMD_BSP * Board specific commands
615 CONFIG_CMD_BOOTD bootd
616 CONFIG_CMD_CACHE * icache, dcache
617 CONFIG_CMD_CONSOLE coninfo
618 CONFIG_CMD_DATE * support for RTC, date/time...
619 CONFIG_CMD_DHCP * DHCP support
620 CONFIG_CMD_DIAG * Diagnostics
621 CONFIG_CMD_DS4510 * ds4510 I2C gpio commands
622 CONFIG_CMD_DS4510_INFO * ds4510 I2C info command
623 CONFIG_CMD_DS4510_MEM * ds4510 I2C eeprom/sram commansd
624 CONFIG_CMD_DS4510_RST * ds4510 I2C rst command
625 CONFIG_CMD_DTT * Digital Therm and Thermostat
626 CONFIG_CMD_ECHO echo arguments
627 CONFIG_CMD_EDITENV edit env variable
628 CONFIG_CMD_EEPROM * EEPROM read/write support
629 CONFIG_CMD_ELF * bootelf, bootvx
630 CONFIG_CMD_SAVEENV saveenv
631 CONFIG_CMD_FDC * Floppy Disk Support
632 CONFIG_CMD_FAT * FAT partition support
633 CONFIG_CMD_FDOS * Dos diskette Support
634 CONFIG_CMD_FLASH flinfo, erase, protect
635 CONFIG_CMD_FPGA FPGA device initialization support
636 CONFIG_CMD_HWFLOW * RTS/CTS hw flow control
637 CONFIG_CMD_I2C * I2C serial bus support
638 CONFIG_CMD_IDE * IDE harddisk support
639 CONFIG_CMD_IMI iminfo
640 CONFIG_CMD_IMLS List all found images
641 CONFIG_CMD_IMMAP * IMMR dump support
642 CONFIG_CMD_IRQ * irqinfo
643 CONFIG_CMD_ITEST Integer/string test of 2 values
644 CONFIG_CMD_JFFS2 * JFFS2 Support
645 CONFIG_CMD_KGDB * kgdb
646 CONFIG_CMD_LOADB loadb
647 CONFIG_CMD_LOADS loads
648 CONFIG_CMD_MD5SUM print md5 message digest
649 (requires CONFIG_CMD_MEMORY and CONFIG_MD5)
650 CONFIG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base,
652 CONFIG_CMD_MISC Misc functions like sleep etc
653 CONFIG_CMD_MMC * MMC memory mapped support
654 CONFIG_CMD_MII * MII utility commands
655 CONFIG_CMD_MTDPARTS * MTD partition support
656 CONFIG_CMD_NAND * NAND support
657 CONFIG_CMD_NET bootp, tftpboot, rarpboot
658 CONFIG_CMD_PCA953X * PCA953x I2C gpio commands
659 CONFIG_CMD_PCA953X_INFO * PCA953x I2C gpio info command
660 CONFIG_CMD_PCI * pciinfo
661 CONFIG_CMD_PCMCIA * PCMCIA support
662 CONFIG_CMD_PING * send ICMP ECHO_REQUEST to network
664 CONFIG_CMD_PORTIO * Port I/O
665 CONFIG_CMD_REGINFO * Register dump
666 CONFIG_CMD_RUN run command in env variable
667 CONFIG_CMD_SAVES * save S record dump
668 CONFIG_CMD_SCSI * SCSI Support
669 CONFIG_CMD_SDRAM * print SDRAM configuration information
670 (requires CONFIG_CMD_I2C)
671 CONFIG_CMD_SETGETDCR Support for DCR Register access
673 CONFIG_CMD_SHA1 print sha1 memory digest
674 (requires CONFIG_CMD_MEMORY)
675 CONFIG_CMD_SOURCE "source" command Support
676 CONFIG_CMD_SPI * SPI serial bus support
677 CONFIG_CMD_USB * USB support
678 CONFIG_CMD_VFD * VFD support (TRAB)
679 CONFIG_CMD_CDP * Cisco Discover Protocol support
680 CONFIG_CMD_FSL * Microblaze FSL support
683 EXAMPLE: If you want all functions except of network
684 support you can write:
686 #include "config_cmd_all.h"
687 #undef CONFIG_CMD_NET
690 fdt (flattened device tree) command: CONFIG_OF_LIBFDT
692 Note: Don't enable the "icache" and "dcache" commands
693 (configuration option CONFIG_CMD_CACHE) unless you know
694 what you (and your U-Boot users) are doing. Data
695 cache cannot be enabled on systems like the 8xx or
696 8260 (where accesses to the IMMR region must be
697 uncached), and it cannot be disabled on all other
698 systems where we (mis-) use the data cache to hold an
699 initial stack and some data.
702 XXX - this list needs to get updated!
706 If this variable is defined, it enables watchdog
707 support. There must be support in the platform specific
708 code for a watchdog. For the 8xx and 8260 CPUs, the
709 SIU Watchdog feature is enabled in the SYPCR
713 CONFIG_VERSION_VARIABLE
714 If this variable is defined, an environment variable
715 named "ver" is created by U-Boot showing the U-Boot
716 version as printed by the "version" command.
717 This variable is readonly.
721 When CONFIG_CMD_DATE is selected, the type of the RTC
722 has to be selected, too. Define exactly one of the
725 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx
726 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC
727 CONFIG_RTC_MC13783 - use MC13783 RTC
728 CONFIG_RTC_MC146818 - use MC146818 RTC
729 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC
730 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC
731 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC
732 CONFIG_RTC_DS164x - use Dallas DS164x RTC
733 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC
734 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC
735 CONFIG_SYS_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337
737 Note that if the RTC uses I2C, then the I2C interface
738 must also be configured. See I2C Support, below.
741 CONFIG_PCA953X - use NXP's PCA953X series I2C GPIO
742 CONFIG_PCA953X_INFO - enable pca953x info command
744 Note that if the GPIO device uses I2C, then the I2C interface
745 must also be configured. See I2C Support, below.
749 When CONFIG_TIMESTAMP is selected, the timestamp
750 (date and time) of an image is printed by image
751 commands like bootm or iminfo. This option is
752 automatically enabled when you select CONFIG_CMD_DATE .
755 CONFIG_MAC_PARTITION and/or CONFIG_DOS_PARTITION
756 and/or CONFIG_ISO_PARTITION and/or CONFIG_EFI_PARTITION
758 If IDE or SCSI support is enabled (CONFIG_CMD_IDE or
759 CONFIG_CMD_SCSI) you must configure support for at
760 least one partition type as well.
763 CONFIG_IDE_RESET_ROUTINE - this is defined in several
764 board configurations files but used nowhere!
766 CONFIG_IDE_RESET - is this is defined, IDE Reset will
767 be performed by calling the function
768 ide_set_reset(int reset)
769 which has to be defined in a board specific file
774 Set this to enable ATAPI support.
779 Set this to enable support for disks larger than 137GB
780 Also look at CONFIG_SYS_64BIT_LBA.
781 Whithout these , LBA48 support uses 32bit variables and will 'only'
782 support disks up to 2.1TB.
784 CONFIG_SYS_64BIT_LBA:
785 When enabled, makes the IDE subsystem use 64bit sector addresses.
789 At the moment only there is only support for the
790 SYM53C8XX SCSI controller; define
791 CONFIG_SCSI_SYM53C8XX to enable it.
793 CONFIG_SYS_SCSI_MAX_LUN [8], CONFIG_SYS_SCSI_MAX_SCSI_ID [7] and
794 CONFIG_SYS_SCSI_MAX_DEVICE [CONFIG_SYS_SCSI_MAX_SCSI_ID *
795 CONFIG_SYS_SCSI_MAX_LUN] can be adjusted to define the
796 maximum numbers of LUNs, SCSI ID's and target
798 CONFIG_SYS_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz)
800 - NETWORK Support (PCI):
802 Support for Intel 8254x gigabit chips.
804 CONFIG_E1000_FALLBACK_MAC
805 default MAC for empty EEPROM after production.
808 Support for Intel 82557/82559/82559ER chips.
809 Optional CONFIG_EEPRO100_SROM_WRITE enables EEPROM
810 write routine for first time initialisation.
813 Support for Digital 2114x chips.
814 Optional CONFIG_TULIP_SELECT_MEDIA for board specific
815 modem chip initialisation (KS8761/QS6611).
818 Support for National dp83815 chips.
821 Support for National dp8382[01] gigabit chips.
823 - NETWORK Support (other):
825 CONFIG_DRIVER_LAN91C96
826 Support for SMSC's LAN91C96 chips.
829 Define this to hold the physical address
830 of the LAN91C96's I/O space
832 CONFIG_LAN91C96_USE_32_BIT
833 Define this to enable 32 bit addressing
835 CONFIG_DRIVER_SMC91111
836 Support for SMSC's LAN91C111 chip
839 Define this to hold the physical address
840 of the device (I/O space)
842 CONFIG_SMC_USE_32_BIT
843 Define this if data bus is 32 bits
845 CONFIG_SMC_USE_IOFUNCS
846 Define this to use i/o functions instead of macros
847 (some hardware wont work with macros)
850 Support for SMSC's LAN911x and LAN921x chips
853 Define this to hold the physical address
854 of the device (I/O space)
856 CONFIG_SMC911X_32_BIT
857 Define this if data bus is 32 bits
859 CONFIG_SMC911X_16_BIT
860 Define this if data bus is 16 bits. If your processor
861 automatically converts one 32 bit word to two 16 bit
862 words you may also try CONFIG_SMC911X_32_BIT.
865 At the moment only the UHCI host controller is
866 supported (PIP405, MIP405, MPC5200); define
867 CONFIG_USB_UHCI to enable it.
868 define CONFIG_USB_KEYBOARD to enable the USB Keyboard
869 and define CONFIG_USB_STORAGE to enable the USB
872 Supported are USB Keyboards and USB Floppy drives
874 MPC5200 USB requires additional defines:
876 for 528 MHz Clock: 0x0001bbbb
880 for differential drivers: 0x00001000
881 for single ended drivers: 0x00005000
882 for differential drivers on PSC3: 0x00000100
883 for single ended drivers on PSC3: 0x00004100
884 CONFIG_SYS_USB_EVENT_POLL
885 May be defined to allow interrupt polling
886 instead of using asynchronous interrupts
889 Define the below if you wish to use the USB console.
890 Once firmware is rebuilt from a serial console issue the
891 command "setenv stdin usbtty; setenv stdout usbtty" and
892 attach your USB cable. The Unix command "dmesg" should print
893 it has found a new device. The environment variable usbtty
894 can be set to gserial or cdc_acm to enable your device to
895 appear to a USB host as a Linux gserial device or a
896 Common Device Class Abstract Control Model serial device.
897 If you select usbtty = gserial you should be able to enumerate
899 # modprobe usbserial vendor=0xVendorID product=0xProductID
900 else if using cdc_acm, simply setting the environment
901 variable usbtty to be cdc_acm should suffice. The following
902 might be defined in YourBoardName.h
905 Define this to build a UDC device
908 Define this to have a tty type of device available to
909 talk to the UDC device
911 CONFIG_SYS_CONSOLE_IS_IN_ENV
912 Define this if you want stdin, stdout &/or stderr to
916 CONFIG_SYS_USB_EXTC_CLK 0xBLAH
917 Derive USB clock from external clock "blah"
918 - CONFIG_SYS_USB_EXTC_CLK 0x02
920 CONFIG_SYS_USB_BRG_CLK 0xBLAH
921 Derive USB clock from brgclk
922 - CONFIG_SYS_USB_BRG_CLK 0x04
924 If you have a USB-IF assigned VendorID then you may wish to
925 define your own vendor specific values either in BoardName.h
926 or directly in usbd_vendor_info.h. If you don't define
927 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME,
928 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot
929 should pretend to be a Linux device to it's target host.
931 CONFIG_USBD_MANUFACTURER
932 Define this string as the name of your company for
933 - CONFIG_USBD_MANUFACTURER "my company"
935 CONFIG_USBD_PRODUCT_NAME
936 Define this string as the name of your product
937 - CONFIG_USBD_PRODUCT_NAME "acme usb device"
940 Define this as your assigned Vendor ID from the USB
941 Implementors Forum. This *must* be a genuine Vendor ID
942 to avoid polluting the USB namespace.
943 - CONFIG_USBD_VENDORID 0xFFFF
945 CONFIG_USBD_PRODUCTID
946 Define this as the unique Product ID
948 - CONFIG_USBD_PRODUCTID 0xFFFF
952 The MMC controller on the Intel PXA is supported. To
953 enable this define CONFIG_MMC. The MMC can be
954 accessed from the boot prompt by mapping the device
955 to physical memory similar to flash. Command line is
956 enabled with CONFIG_CMD_MMC. The MMC driver also works with
957 the FAT fs. This is enabled with CONFIG_CMD_FAT.
959 - Journaling Flash filesystem support:
960 CONFIG_JFFS2_NAND, CONFIG_JFFS2_NAND_OFF, CONFIG_JFFS2_NAND_SIZE,
961 CONFIG_JFFS2_NAND_DEV
962 Define these for a default partition on a NAND device
964 CONFIG_SYS_JFFS2_FIRST_SECTOR,
965 CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS
966 Define these for a default partition on a NOR device
968 CONFIG_SYS_JFFS_CUSTOM_PART
969 Define this to create an own partition. You have to provide a
970 function struct part_info* jffs2_part_info(int part_num)
972 If you define only one JFFS2 partition you may also want to
973 #define CONFIG_SYS_JFFS_SINGLE_PART 1
974 to disable the command chpart. This is the default when you
975 have not defined a custom partition
980 Define this to enable standard (PC-Style) keyboard
984 Standard PC keyboard driver with US (is default) and
985 GERMAN key layout (switch via environment 'keymap=de') support.
986 Export function i8042_kbd_init, i8042_tstc and i8042_getc
987 for cfb_console. Supports cursor blinking.
992 Define this to enable video support (for output to
997 Enable Chips & Technologies 69000 Video chip
999 CONFIG_VIDEO_SMI_LYNXEM
1000 Enable Silicon Motion SMI 712/710/810 Video chip. The
1001 video output is selected via environment 'videoout'
1002 (1 = LCD and 2 = CRT). If videoout is undefined, CRT is
1005 For the CT69000 and SMI_LYNXEM drivers, videomode is
1006 selected via environment 'videomode'. Two different ways
1008 - "videomode=num" 'num' is a standard LiLo mode numbers.
1009 Following standard modes are supported (* is default):
1011 Colors 640x480 800x600 1024x768 1152x864 1280x1024
1012 -------------+---------------------------------------------
1013 8 bits | 0x301* 0x303 0x305 0x161 0x307
1014 15 bits | 0x310 0x313 0x316 0x162 0x319
1015 16 bits | 0x311 0x314 0x317 0x163 0x31A
1016 24 bits | 0x312 0x315 0x318 ? 0x31B
1017 -------------+---------------------------------------------
1018 (i.e. setenv videomode 317; saveenv; reset;)
1020 - "videomode=bootargs" all the video parameters are parsed
1021 from the bootargs. (See drivers/video/videomodes.c)
1024 CONFIG_VIDEO_SED13806
1025 Enable Epson SED13806 driver. This driver supports 8bpp
1026 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP
1027 or CONFIG_VIDEO_SED13806_16BPP
1032 Define this to enable a custom keyboard support.
1033 This simply calls drv_keyboard_init() which must be
1034 defined in your board-specific files.
1035 The only board using this so far is RBC823.
1037 - LCD Support: CONFIG_LCD
1039 Define this to enable LCD support (for output to LCD
1040 display); also select one of the supported displays
1041 by defining one of these:
1045 HITACHI TX09D70VM1CCA, 3.5", 240x320.
1047 CONFIG_NEC_NL6448AC33:
1049 NEC NL6448AC33-18. Active, color, single scan.
1051 CONFIG_NEC_NL6448BC20
1053 NEC NL6448BC20-08. 6.5", 640x480.
1054 Active, color, single scan.
1056 CONFIG_NEC_NL6448BC33_54
1058 NEC NL6448BC33-54. 10.4", 640x480.
1059 Active, color, single scan.
1063 Sharp 320x240. Active, color, single scan.
1064 It isn't 16x9, and I am not sure what it is.
1066 CONFIG_SHARP_LQ64D341
1068 Sharp LQ64D341 display, 640x480.
1069 Active, color, single scan.
1073 HLD1045 display, 640x480.
1074 Active, color, single scan.
1078 Optrex CBL50840-2 NF-FW 99 22 M5
1080 Hitachi LMG6912RPFC-00T
1084 320x240. Black & white.
1086 Normally display is black on white background; define
1087 CONFIG_SYS_WHITE_ON_BLACK to get it inverted.
1089 - Splash Screen Support: CONFIG_SPLASH_SCREEN
1091 If this option is set, the environment is checked for
1092 a variable "splashimage". If found, the usual display
1093 of logo, copyright and system information on the LCD
1094 is suppressed and the BMP image at the address
1095 specified in "splashimage" is loaded instead. The
1096 console is redirected to the "nulldev", too. This
1097 allows for a "silent" boot where a splash screen is
1098 loaded very quickly after power-on.
1100 CONFIG_SPLASH_SCREEN_ALIGN
1102 If this option is set the splash image can be freely positioned
1103 on the screen. Environment variable "splashpos" specifies the
1104 position as "x,y". If a positive number is given it is used as
1105 number of pixel from left/top. If a negative number is given it
1106 is used as number of pixel from right/bottom. You can also
1107 specify 'm' for centering the image.
1110 setenv splashpos m,m
1111 => image at center of screen
1113 setenv splashpos 30,20
1114 => image at x = 30 and y = 20
1116 setenv splashpos -10,m
1117 => vertically centered image
1118 at x = dspWidth - bmpWidth - 9
1120 - Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP
1122 If this option is set, additionally to standard BMP
1123 images, gzipped BMP images can be displayed via the
1124 splashscreen support or the bmp command.
1126 - Compression support:
1129 If this option is set, support for bzip2 compressed
1130 images is included. If not, only uncompressed and gzip
1131 compressed images are supported.
1133 NOTE: the bzip2 algorithm requires a lot of RAM, so
1134 the malloc area (as defined by CONFIG_SYS_MALLOC_LEN) should
1139 If this option is set, support for lzma compressed
1142 Note: The LZMA algorithm adds between 2 and 4KB of code and it
1143 requires an amount of dynamic memory that is given by the
1146 (1846 + 768 << (lc + lp)) * sizeof(uint16)
1148 Where lc and lp stand for, respectively, Literal context bits
1149 and Literal pos bits.
1151 This value is upper-bounded by 14MB in the worst case. Anyway,
1152 for a ~4MB large kernel image, we have lc=3 and lp=0 for a
1153 total amount of (1846 + 768 << (3 + 0)) * 2 = ~41KB... that is
1154 a very small buffer.
1156 Use the lzmainfo tool to determinate the lc and lp values and
1157 then calculate the amount of needed dynamic memory (ensuring
1158 the appropriate CONFIG_SYS_MALLOC_LEN value).
1163 The address of PHY on MII bus.
1165 CONFIG_PHY_CLOCK_FREQ (ppc4xx)
1167 The clock frequency of the MII bus
1171 If this option is set, support for speed/duplex
1172 detection of gigabit PHY is included.
1174 CONFIG_PHY_RESET_DELAY
1176 Some PHY like Intel LXT971A need extra delay after
1177 reset before any MII register access is possible.
1178 For such PHY, set this option to the usec delay
1179 required. (minimum 300usec for LXT971A)
1181 CONFIG_PHY_CMD_DELAY (ppc4xx)
1183 Some PHY like Intel LXT971A need extra delay after
1184 command issued before MII status register can be read
1194 Define a default value for Ethernet address to use
1195 for the respective Ethernet interface, in case this
1196 is not determined automatically.
1201 Define a default value for the IP address to use for
1202 the default Ethernet interface, in case this is not
1203 determined through e.g. bootp.
1205 - Server IP address:
1208 Defines a default value for the IP address of a TFTP
1209 server to contact when using the "tftboot" command.
1211 CONFIG_KEEP_SERVERADDR
1213 Keeps the server's MAC address, in the env 'serveraddr'
1214 for passing to bootargs (like Linux's netconsole option)
1216 - Multicast TFTP Mode:
1219 Defines whether you want to support multicast TFTP as per
1220 rfc-2090; for example to work with atftp. Lets lots of targets
1221 tftp down the same boot image concurrently. Note: the Ethernet
1222 driver in use must provide a function: mcast() to join/leave a
1225 CONFIG_BOOTP_RANDOM_DELAY
1226 - BOOTP Recovery Mode:
1227 CONFIG_BOOTP_RANDOM_DELAY
1229 If you have many targets in a network that try to
1230 boot using BOOTP, you may want to avoid that all
1231 systems send out BOOTP requests at precisely the same
1232 moment (which would happen for instance at recovery
1233 from a power failure, when all systems will try to
1234 boot, thus flooding the BOOTP server. Defining
1235 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
1236 inserted before sending out BOOTP requests. The
1237 following delays are inserted then:
1239 1st BOOTP request: delay 0 ... 1 sec
1240 2nd BOOTP request: delay 0 ... 2 sec
1241 3rd BOOTP request: delay 0 ... 4 sec
1243 BOOTP requests: delay 0 ... 8 sec
1245 - DHCP Advanced Options:
1246 You can fine tune the DHCP functionality by defining
1247 CONFIG_BOOTP_* symbols:
1249 CONFIG_BOOTP_SUBNETMASK
1250 CONFIG_BOOTP_GATEWAY
1251 CONFIG_BOOTP_HOSTNAME
1252 CONFIG_BOOTP_NISDOMAIN
1253 CONFIG_BOOTP_BOOTPATH
1254 CONFIG_BOOTP_BOOTFILESIZE
1257 CONFIG_BOOTP_SEND_HOSTNAME
1258 CONFIG_BOOTP_NTPSERVER
1259 CONFIG_BOOTP_TIMEOFFSET
1260 CONFIG_BOOTP_VENDOREX
1262 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip
1263 environment variable, not the BOOTP server.
1265 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS
1266 serverip from a DHCP server, it is possible that more
1267 than one DNS serverip is offered to the client.
1268 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS
1269 serverip will be stored in the additional environment
1270 variable "dnsip2". The first DNS serverip is always
1271 stored in the variable "dnsip", when CONFIG_BOOTP_DNS
1274 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable
1275 to do a dynamic update of a DNS server. To do this, they
1276 need the hostname of the DHCP requester.
1277 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content
1278 of the "hostname" environment variable is passed as
1279 option 12 to the DHCP server.
1281 CONFIG_BOOTP_DHCP_REQUEST_DELAY
1283 A 32bit value in microseconds for a delay between
1284 receiving a "DHCP Offer" and sending the "DHCP Request".
1285 This fixes a problem with certain DHCP servers that don't
1286 respond 100% of the time to a "DHCP request". E.g. On an
1287 AT91RM9200 processor running at 180MHz, this delay needed
1288 to be *at least* 15,000 usec before a Windows Server 2003
1289 DHCP server would reply 100% of the time. I recommend at
1290 least 50,000 usec to be safe. The alternative is to hope
1291 that one of the retries will be successful but note that
1292 the DHCP timeout and retry process takes a longer than
1296 CONFIG_CDP_DEVICE_ID
1298 The device id used in CDP trigger frames.
1300 CONFIG_CDP_DEVICE_ID_PREFIX
1302 A two character string which is prefixed to the MAC address
1307 A printf format string which contains the ascii name of
1308 the port. Normally is set to "eth%d" which sets
1309 eth0 for the first Ethernet, eth1 for the second etc.
1311 CONFIG_CDP_CAPABILITIES
1313 A 32bit integer which indicates the device capabilities;
1314 0x00000010 for a normal host which does not forwards.
1318 An ascii string containing the version of the software.
1322 An ascii string containing the name of the platform.
1326 A 32bit integer sent on the trigger.
1328 CONFIG_CDP_POWER_CONSUMPTION
1330 A 16bit integer containing the power consumption of the
1331 device in .1 of milliwatts.
1333 CONFIG_CDP_APPLIANCE_VLAN_TYPE
1335 A byte containing the id of the VLAN.
1337 - Status LED: CONFIG_STATUS_LED
1339 Several configurations allow to display the current
1340 status using a LED. For instance, the LED will blink
1341 fast while running U-Boot code, stop blinking as
1342 soon as a reply to a BOOTP request was received, and
1343 start blinking slow once the Linux kernel is running
1344 (supported by a status LED driver in the Linux
1345 kernel). Defining CONFIG_STATUS_LED enables this
1348 - CAN Support: CONFIG_CAN_DRIVER
1350 Defining CONFIG_CAN_DRIVER enables CAN driver support
1351 on those systems that support this (optional)
1352 feature, like the TQM8xxL modules.
1354 - I2C Support: CONFIG_HARD_I2C | CONFIG_SOFT_I2C
1356 These enable I2C serial bus commands. Defining either of
1357 (but not both of) CONFIG_HARD_I2C or CONFIG_SOFT_I2C will
1358 include the appropriate I2C driver for the selected CPU.
1360 This will allow you to use i2c commands at the u-boot
1361 command line (as long as you set CONFIG_CMD_I2C in
1362 CONFIG_COMMANDS) and communicate with i2c based realtime
1363 clock chips. See common/cmd_i2c.c for a description of the
1364 command line interface.
1366 CONFIG_HARD_I2C selects a hardware I2C controller.
1368 CONFIG_SOFT_I2C configures u-boot to use a software (aka
1369 bit-banging) driver instead of CPM or similar hardware
1372 There are several other quantities that must also be
1373 defined when you define CONFIG_HARD_I2C or CONFIG_SOFT_I2C.
1375 In both cases you will need to define CONFIG_SYS_I2C_SPEED
1376 to be the frequency (in Hz) at which you wish your i2c bus
1377 to run and CONFIG_SYS_I2C_SLAVE to be the address of this node (ie
1378 the CPU's i2c node address).
1380 Now, the u-boot i2c code for the mpc8xx (cpu/mpc8xx/i2c.c)
1381 sets the CPU up as a master node and so its address should
1382 therefore be cleared to 0 (See, eg, MPC823e User's Manual
1383 p.16-473). So, set CONFIG_SYS_I2C_SLAVE to 0.
1385 CONFIG_SYS_I2C_INIT_MPC5XXX
1387 When a board is reset during an i2c bus transfer
1388 chips might think that the current transfer is still
1389 in progress. Reset the slave devices by sending start
1390 commands until the slave device responds.
1392 That's all that's required for CONFIG_HARD_I2C.
1394 If you use the software i2c interface (CONFIG_SOFT_I2C)
1395 then the following macros need to be defined (examples are
1396 from include/configs/lwmon.h):
1400 (Optional). Any commands necessary to enable the I2C
1401 controller or configure ports.
1403 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
1407 (Only for MPC8260 CPU). The I/O port to use (the code
1408 assumes both bits are on the same port). Valid values
1409 are 0..3 for ports A..D.
1413 The code necessary to make the I2C data line active
1414 (driven). If the data line is open collector, this
1417 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
1421 The code necessary to make the I2C data line tri-stated
1422 (inactive). If the data line is open collector, this
1425 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
1429 Code that returns TRUE if the I2C data line is high,
1432 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
1436 If <bit> is TRUE, sets the I2C data line high. If it
1437 is FALSE, it clears it (low).
1439 eg: #define I2C_SDA(bit) \
1440 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
1441 else immr->im_cpm.cp_pbdat &= ~PB_SDA
1445 If <bit> is TRUE, sets the I2C clock line high. If it
1446 is FALSE, it clears it (low).
1448 eg: #define I2C_SCL(bit) \
1449 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
1450 else immr->im_cpm.cp_pbdat &= ~PB_SCL
1454 This delay is invoked four times per clock cycle so this
1455 controls the rate of data transfer. The data rate thus
1456 is 1 / (I2C_DELAY * 4). Often defined to be something
1459 #define I2C_DELAY udelay(2)
1461 CONFIG_SYS_I2C_INIT_BOARD
1463 When a board is reset during an i2c bus transfer
1464 chips might think that the current transfer is still
1465 in progress. On some boards it is possible to access
1466 the i2c SCLK line directly, either by using the
1467 processor pin as a GPIO or by having a second pin
1468 connected to the bus. If this option is defined a
1469 custom i2c_init_board() routine in boards/xxx/board.c
1470 is run early in the boot sequence.
1472 CONFIG_I2CFAST (PPC405GP|PPC405EP only)
1474 This option enables configuration of bi_iic_fast[] flags
1475 in u-boot bd_info structure based on u-boot environment
1476 variable "i2cfast". (see also i2cfast)
1478 CONFIG_I2C_MULTI_BUS
1480 This option allows the use of multiple I2C buses, each of which
1481 must have a controller. At any point in time, only one bus is
1482 active. To switch to a different bus, use the 'i2c dev' command.
1483 Note that bus numbering is zero-based.
1485 CONFIG_SYS_I2C_NOPROBES
1487 This option specifies a list of I2C devices that will be skipped
1488 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS
1489 is set, specify a list of bus-device pairs. Otherwise, specify
1490 a 1D array of device addresses
1493 #undef CONFIG_I2C_MULTI_BUS
1494 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68}
1496 will skip addresses 0x50 and 0x68 on a board with one I2C bus
1498 #define CONFIG_I2C_MULTI_BUS
1499 #define CONFIG_SYS_I2C_MULTI_NOPROBES {{0,0x50},{0,0x68},{1,0x54}}
1501 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1
1503 CONFIG_SYS_SPD_BUS_NUM
1505 If defined, then this indicates the I2C bus number for DDR SPD.
1506 If not defined, then U-Boot assumes that SPD is on I2C bus 0.
1508 CONFIG_SYS_RTC_BUS_NUM
1510 If defined, then this indicates the I2C bus number for the RTC.
1511 If not defined, then U-Boot assumes that RTC is on I2C bus 0.
1513 CONFIG_SYS_DTT_BUS_NUM
1515 If defined, then this indicates the I2C bus number for the DTT.
1516 If not defined, then U-Boot assumes that DTT is on I2C bus 0.
1518 CONFIG_SYS_I2C_DTT_ADDR:
1520 If defined, specifies the I2C address of the DTT device.
1521 If not defined, then U-Boot uses predefined value for
1522 specified DTT device.
1526 Define this option if you want to use Freescale's I2C driver in
1527 drivers/i2c/fsl_i2c.c.
1531 Define this option if you have I2C devices reached over 1 .. n
1532 I2C Muxes like the pca9544a. This option addes a new I2C
1533 Command "i2c bus [muxtype:muxaddr:muxchannel]" which adds a
1534 new I2C Bus to the existing I2C Busses. If you select the
1535 new Bus with "i2c dev", u-bbot sends first the commandos for
1536 the muxes to activate this new "bus".
1538 CONFIG_I2C_MULTI_BUS must be also defined, to use this
1542 Adding a new I2C Bus reached over 2 pca9544a muxes
1543 The First mux with address 70 and channel 6
1544 The Second mux with address 71 and channel 4
1546 => i2c bus pca9544a:70:6:pca9544a:71:4
1548 Use the "i2c bus" command without parameter, to get a list
1549 of I2C Busses with muxes:
1552 Busses reached over muxes:
1554 reached over Mux(es):
1557 reached over Mux(es):
1562 If you now switch to the new I2C Bus 3 with "i2c dev 3"
1563 u-boot sends First the Commando to the mux@70 to enable
1564 channel 6, and then the Commando to the mux@71 to enable
1567 After that, you can use the "normal" i2c commands as
1568 usual, to communicate with your I2C devices behind
1571 This option is actually implemented for the bitbanging
1572 algorithm in common/soft_i2c.c and for the Hardware I2C
1573 Bus on the MPC8260. But it should be not so difficult
1574 to add this option to other architectures.
1576 CONFIG_SOFT_I2C_READ_REPEATED_START
1578 defining this will force the i2c_read() function in
1579 the soft_i2c driver to perform an I2C repeated start
1580 between writing the address pointer and reading the
1581 data. If this define is omitted the default behaviour
1582 of doing a stop-start sequence will be used. Most I2C
1583 devices can use either method, but some require one or
1586 - SPI Support: CONFIG_SPI
1588 Enables SPI driver (so far only tested with
1589 SPI EEPROM, also an instance works with Crystal A/D and
1590 D/As on the SACSng board)
1594 Enables extended (16-bit) SPI EEPROM addressing.
1595 (symmetrical to CONFIG_I2C_X)
1599 Enables a software (bit-bang) SPI driver rather than
1600 using hardware support. This is a general purpose
1601 driver that only requires three general I/O port pins
1602 (two outputs, one input) to function. If this is
1603 defined, the board configuration must define several
1604 SPI configuration items (port pins to use, etc). For
1605 an example, see include/configs/sacsng.h.
1609 Enables a hardware SPI driver for general-purpose reads
1610 and writes. As with CONFIG_SOFT_SPI, the board configuration
1611 must define a list of chip-select function pointers.
1612 Currently supported on some MPC8xxx processors. For an
1613 example, see include/configs/mpc8349emds.h.
1617 Enables the driver for the SPI controllers on i.MX and MXC
1618 SoCs. Currently only i.MX31 is supported.
1620 - FPGA Support: CONFIG_FPGA
1622 Enables FPGA subsystem.
1624 CONFIG_FPGA_<vendor>
1626 Enables support for specific chip vendors.
1629 CONFIG_FPGA_<family>
1631 Enables support for FPGA family.
1632 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX)
1636 Specify the number of FPGA devices to support.
1638 CONFIG_SYS_FPGA_PROG_FEEDBACK
1640 Enable printing of hash marks during FPGA configuration.
1642 CONFIG_SYS_FPGA_CHECK_BUSY
1644 Enable checks on FPGA configuration interface busy
1645 status by the configuration function. This option
1646 will require a board or device specific function to
1651 If defined, a function that provides delays in the FPGA
1652 configuration driver.
1654 CONFIG_SYS_FPGA_CHECK_CTRLC
1655 Allow Control-C to interrupt FPGA configuration
1657 CONFIG_SYS_FPGA_CHECK_ERROR
1659 Check for configuration errors during FPGA bitfile
1660 loading. For example, abort during Virtex II
1661 configuration if the INIT_B line goes low (which
1662 indicated a CRC error).
1664 CONFIG_SYS_FPGA_WAIT_INIT
1666 Maximum time to wait for the INIT_B line to deassert
1667 after PROB_B has been deasserted during a Virtex II
1668 FPGA configuration sequence. The default time is 500
1671 CONFIG_SYS_FPGA_WAIT_BUSY
1673 Maximum time to wait for BUSY to deassert during
1674 Virtex II FPGA configuration. The default is 5 ms.
1676 CONFIG_SYS_FPGA_WAIT_CONFIG
1678 Time to wait after FPGA configuration. The default is
1681 - Configuration Management:
1684 If defined, this string will be added to the U-Boot
1685 version information (U_BOOT_VERSION)
1687 - Vendor Parameter Protection:
1689 U-Boot considers the values of the environment
1690 variables "serial#" (Board Serial Number) and
1691 "ethaddr" (Ethernet Address) to be parameters that
1692 are set once by the board vendor / manufacturer, and
1693 protects these variables from casual modification by
1694 the user. Once set, these variables are read-only,
1695 and write or delete attempts are rejected. You can
1696 change this behaviour:
1698 If CONFIG_ENV_OVERWRITE is #defined in your config
1699 file, the write protection for vendor parameters is
1700 completely disabled. Anybody can change or delete
1703 Alternatively, if you #define _both_ CONFIG_ETHADDR
1704 _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
1705 Ethernet address is installed in the environment,
1706 which can be changed exactly ONCE by the user. [The
1707 serial# is unaffected by this, i. e. it remains
1713 Define this variable to enable the reservation of
1714 "protected RAM", i. e. RAM which is not overwritten
1715 by U-Boot. Define CONFIG_PRAM to hold the number of
1716 kB you want to reserve for pRAM. You can overwrite
1717 this default value by defining an environment
1718 variable "pram" to the number of kB you want to
1719 reserve. Note that the board info structure will
1720 still show the full amount of RAM. If pRAM is
1721 reserved, a new environment variable "mem" will
1722 automatically be defined to hold the amount of
1723 remaining RAM in a form that can be passed as boot
1724 argument to Linux, for instance like that:
1726 setenv bootargs ... mem=\${mem}
1729 This way you can tell Linux not to use this memory,
1730 either, which results in a memory region that will
1731 not be affected by reboots.
1733 *WARNING* If your board configuration uses automatic
1734 detection of the RAM size, you must make sure that
1735 this memory test is non-destructive. So far, the
1736 following board configurations are known to be
1739 ETX094, IVMS8, IVML24, SPD8xx, TQM8xxL,
1740 HERMES, IP860, RPXlite, LWMON, LANTEC,
1741 PCU_E, FLAGADM, TQM8260
1746 Define this variable to stop the system in case of a
1747 fatal error, so that you have to reset it manually.
1748 This is probably NOT a good idea for an embedded
1749 system where you want the system to reboot
1750 automatically as fast as possible, but it may be
1751 useful during development since you can try to debug
1752 the conditions that lead to the situation.
1754 CONFIG_NET_RETRY_COUNT
1756 This variable defines the number of retries for
1757 network operations like ARP, RARP, TFTP, or BOOTP
1758 before giving up the operation. If not defined, a
1759 default value of 5 is used.
1763 Timeout waiting for an ARP reply in milliseconds.
1765 - Command Interpreter:
1766 CONFIG_AUTO_COMPLETE
1768 Enable auto completion of commands using TAB.
1770 Note that this feature has NOT been implemented yet
1771 for the "hush" shell.
1774 CONFIG_SYS_HUSH_PARSER
1776 Define this variable to enable the "hush" shell (from
1777 Busybox) as command line interpreter, thus enabling
1778 powerful command line syntax like
1779 if...then...else...fi conditionals or `&&' and '||'
1780 constructs ("shell scripts").
1782 If undefined, you get the old, much simpler behaviour
1783 with a somewhat smaller memory footprint.
1786 CONFIG_SYS_PROMPT_HUSH_PS2
1788 This defines the secondary prompt string, which is
1789 printed when the command interpreter needs more input
1790 to complete a command. Usually "> ".
1794 In the current implementation, the local variables
1795 space and global environment variables space are
1796 separated. Local variables are those you define by
1797 simply typing `name=value'. To access a local
1798 variable later on, you have write `$name' or
1799 `${name}'; to execute the contents of a variable
1800 directly type `$name' at the command prompt.
1802 Global environment variables are those you use
1803 setenv/printenv to work with. To run a command stored
1804 in such a variable, you need to use the run command,
1805 and you must not use the '$' sign to access them.
1807 To store commands and special characters in a
1808 variable, please use double quotation marks
1809 surrounding the whole text of the variable, instead
1810 of the backslashes before semicolons and special
1813 - Commandline Editing and History:
1814 CONFIG_CMDLINE_EDITING
1816 Enable editing and History functions for interactive
1817 commandline input operations
1819 - Default Environment:
1820 CONFIG_EXTRA_ENV_SETTINGS
1822 Define this to contain any number of null terminated
1823 strings (variable = value pairs) that will be part of
1824 the default environment compiled into the boot image.
1826 For example, place something like this in your
1827 board's config file:
1829 #define CONFIG_EXTRA_ENV_SETTINGS \
1833 Warning: This method is based on knowledge about the
1834 internal format how the environment is stored by the
1835 U-Boot code. This is NOT an official, exported
1836 interface! Although it is unlikely that this format
1837 will change soon, there is no guarantee either.
1838 You better know what you are doing here.
1840 Note: overly (ab)use of the default environment is
1841 discouraged. Make sure to check other ways to preset
1842 the environment like the "source" command or the
1845 - DataFlash Support:
1846 CONFIG_HAS_DATAFLASH
1848 Defining this option enables DataFlash features and
1849 allows to read/write in Dataflash via the standard
1852 - SystemACE Support:
1855 Adding this option adds support for Xilinx SystemACE
1856 chips attached via some sort of local bus. The address
1857 of the chip must also be defined in the
1858 CONFIG_SYS_SYSTEMACE_BASE macro. For example:
1860 #define CONFIG_SYSTEMACE
1861 #define CONFIG_SYS_SYSTEMACE_BASE 0xf0000000
1863 When SystemACE support is added, the "ace" device type
1864 becomes available to the fat commands, i.e. fatls.
1866 - TFTP Fixed UDP Port:
1869 If this is defined, the environment variable tftpsrcp
1870 is used to supply the TFTP UDP source port value.
1871 If tftpsrcp isn't defined, the normal pseudo-random port
1872 number generator is used.
1874 Also, the environment variable tftpdstp is used to supply
1875 the TFTP UDP destination port value. If tftpdstp isn't
1876 defined, the normal port 69 is used.
1878 The purpose for tftpsrcp is to allow a TFTP server to
1879 blindly start the TFTP transfer using the pre-configured
1880 target IP address and UDP port. This has the effect of
1881 "punching through" the (Windows XP) firewall, allowing
1882 the remainder of the TFTP transfer to proceed normally.
1883 A better solution is to properly configure the firewall,
1884 but sometimes that is not allowed.
1886 - Show boot progress:
1887 CONFIG_SHOW_BOOT_PROGRESS
1889 Defining this option allows to add some board-
1890 specific code (calling a user-provided function
1891 "show_boot_progress(int)") that enables you to show
1892 the system's boot progress on some display (for
1893 example, some LED's) on your board. At the moment,
1894 the following checkpoints are implemented:
1896 Legacy uImage format:
1899 1 common/cmd_bootm.c before attempting to boot an image
1900 -1 common/cmd_bootm.c Image header has bad magic number
1901 2 common/cmd_bootm.c Image header has correct magic number
1902 -2 common/cmd_bootm.c Image header has bad checksum
1903 3 common/cmd_bootm.c Image header has correct checksum
1904 -3 common/cmd_bootm.c Image data has bad checksum
1905 4 common/cmd_bootm.c Image data has correct checksum
1906 -4 common/cmd_bootm.c Image is for unsupported architecture
1907 5 common/cmd_bootm.c Architecture check OK
1908 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi)
1909 6 common/cmd_bootm.c Image Type check OK
1910 -6 common/cmd_bootm.c gunzip uncompression error
1911 -7 common/cmd_bootm.c Unimplemented compression type
1912 7 common/cmd_bootm.c Uncompression OK
1913 8 common/cmd_bootm.c No uncompress/copy overwrite error
1914 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX)
1916 9 common/image.c Start initial ramdisk verification
1917 -10 common/image.c Ramdisk header has bad magic number
1918 -11 common/image.c Ramdisk header has bad checksum
1919 10 common/image.c Ramdisk header is OK
1920 -12 common/image.c Ramdisk data has bad checksum
1921 11 common/image.c Ramdisk data has correct checksum
1922 12 common/image.c Ramdisk verification complete, start loading
1923 -13 common/image.c Wrong Image Type (not PPC Linux ramdisk)
1924 13 common/image.c Start multifile image verification
1925 14 common/image.c No initial ramdisk, no multifile, continue.
1927 15 lib_<arch>/bootm.c All preparation done, transferring control to OS
1929 -30 lib_ppc/board.c Fatal error, hang the system
1930 -31 post/post.c POST test failed, detected by post_output_backlog()
1931 -32 post/post.c POST test failed, detected by post_run_single()
1933 34 common/cmd_doc.c before loading a Image from a DOC device
1934 -35 common/cmd_doc.c Bad usage of "doc" command
1935 35 common/cmd_doc.c correct usage of "doc" command
1936 -36 common/cmd_doc.c No boot device
1937 36 common/cmd_doc.c correct boot device
1938 -37 common/cmd_doc.c Unknown Chip ID on boot device
1939 37 common/cmd_doc.c correct chip ID found, device available
1940 -38 common/cmd_doc.c Read Error on boot device
1941 38 common/cmd_doc.c reading Image header from DOC device OK
1942 -39 common/cmd_doc.c Image header has bad magic number
1943 39 common/cmd_doc.c Image header has correct magic number
1944 -40 common/cmd_doc.c Error reading Image from DOC device
1945 40 common/cmd_doc.c Image header has correct magic number
1946 41 common/cmd_ide.c before loading a Image from a IDE device
1947 -42 common/cmd_ide.c Bad usage of "ide" command
1948 42 common/cmd_ide.c correct usage of "ide" command
1949 -43 common/cmd_ide.c No boot device
1950 43 common/cmd_ide.c boot device found
1951 -44 common/cmd_ide.c Device not available
1952 44 common/cmd_ide.c Device available
1953 -45 common/cmd_ide.c wrong partition selected
1954 45 common/cmd_ide.c partition selected
1955 -46 common/cmd_ide.c Unknown partition table
1956 46 common/cmd_ide.c valid partition table found
1957 -47 common/cmd_ide.c Invalid partition type
1958 47 common/cmd_ide.c correct partition type
1959 -48 common/cmd_ide.c Error reading Image Header on boot device
1960 48 common/cmd_ide.c reading Image Header from IDE device OK
1961 -49 common/cmd_ide.c Image header has bad magic number
1962 49 common/cmd_ide.c Image header has correct magic number
1963 -50 common/cmd_ide.c Image header has bad checksum
1964 50 common/cmd_ide.c Image header has correct checksum
1965 -51 common/cmd_ide.c Error reading Image from IDE device
1966 51 common/cmd_ide.c reading Image from IDE device OK
1967 52 common/cmd_nand.c before loading a Image from a NAND device
1968 -53 common/cmd_nand.c Bad usage of "nand" command
1969 53 common/cmd_nand.c correct usage of "nand" command
1970 -54 common/cmd_nand.c No boot device
1971 54 common/cmd_nand.c boot device found
1972 -55 common/cmd_nand.c Unknown Chip ID on boot device
1973 55 common/cmd_nand.c correct chip ID found, device available
1974 -56 common/cmd_nand.c Error reading Image Header on boot device
1975 56 common/cmd_nand.c reading Image Header from NAND device OK
1976 -57 common/cmd_nand.c Image header has bad magic number
1977 57 common/cmd_nand.c Image header has correct magic number
1978 -58 common/cmd_nand.c Error reading Image from NAND device
1979 58 common/cmd_nand.c reading Image from NAND device OK
1981 -60 common/env_common.c Environment has a bad CRC, using default
1983 64 net/eth.c starting with Ethernet configuration.
1984 -64 net/eth.c no Ethernet found.
1985 65 net/eth.c Ethernet found.
1987 -80 common/cmd_net.c usage wrong
1988 80 common/cmd_net.c before calling NetLoop()
1989 -81 common/cmd_net.c some error in NetLoop() occurred
1990 81 common/cmd_net.c NetLoop() back without error
1991 -82 common/cmd_net.c size == 0 (File with size 0 loaded)
1992 82 common/cmd_net.c trying automatic boot
1993 83 common/cmd_net.c running "source" command
1994 -83 common/cmd_net.c some error in automatic boot or "source" command
1995 84 common/cmd_net.c end without errors
2000 100 common/cmd_bootm.c Kernel FIT Image has correct format
2001 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format
2002 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration
2003 -101 common/cmd_bootm.c Can't get configuration for kernel subimage
2004 102 common/cmd_bootm.c Kernel unit name specified
2005 -103 common/cmd_bootm.c Can't get kernel subimage node offset
2006 103 common/cmd_bootm.c Found configuration node
2007 104 common/cmd_bootm.c Got kernel subimage node offset
2008 -104 common/cmd_bootm.c Kernel subimage hash verification failed
2009 105 common/cmd_bootm.c Kernel subimage hash verification OK
2010 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture
2011 106 common/cmd_bootm.c Architecture check OK
2012 -106 common/cmd_bootm.c Kernel subimage has wrong type
2013 107 common/cmd_bootm.c Kernel subimage type OK
2014 -107 common/cmd_bootm.c Can't get kernel subimage data/size
2015 108 common/cmd_bootm.c Got kernel subimage data/size
2016 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT)
2017 -109 common/cmd_bootm.c Can't get kernel subimage type
2018 -110 common/cmd_bootm.c Can't get kernel subimage comp
2019 -111 common/cmd_bootm.c Can't get kernel subimage os
2020 -112 common/cmd_bootm.c Can't get kernel subimage load address
2021 -113 common/cmd_bootm.c Image uncompress/copy overwrite error
2023 120 common/image.c Start initial ramdisk verification
2024 -120 common/image.c Ramdisk FIT image has incorrect format
2025 121 common/image.c Ramdisk FIT image has correct format
2026 122 common/image.c No ramdisk subimage unit name, using configuration
2027 -122 common/image.c Can't get configuration for ramdisk subimage
2028 123 common/image.c Ramdisk unit name specified
2029 -124 common/image.c Can't get ramdisk subimage node offset
2030 125 common/image.c Got ramdisk subimage node offset
2031 -125 common/image.c Ramdisk subimage hash verification failed
2032 126 common/image.c Ramdisk subimage hash verification OK
2033 -126 common/image.c Ramdisk subimage for unsupported architecture
2034 127 common/image.c Architecture check OK
2035 -127 common/image.c Can't get ramdisk subimage data/size
2036 128 common/image.c Got ramdisk subimage data/size
2037 129 common/image.c Can't get ramdisk load address
2038 -129 common/image.c Got ramdisk load address
2040 -130 common/cmd_doc.c Incorrect FIT image format
2041 131 common/cmd_doc.c FIT image format OK
2043 -140 common/cmd_ide.c Incorrect FIT image format
2044 141 common/cmd_ide.c FIT image format OK
2046 -150 common/cmd_nand.c Incorrect FIT image format
2047 151 common/cmd_nand.c FIT image format OK
2049 - Automatic software updates via TFTP server
2051 CONFIG_UPDATE_TFTP_CNT_MAX
2052 CONFIG_UPDATE_TFTP_MSEC_MAX
2054 These options enable and control the auto-update feature;
2055 for a more detailed description refer to doc/README.update.
2057 - MTD Support (mtdparts command, UBI support)
2060 Adds the MTD device infrastructure from the Linux kernel.
2061 Needed for mtdparts command support.
2063 CONFIG_MTD_PARTITIONS
2065 Adds the MTD partitioning infrastructure from the Linux
2066 kernel. Needed for UBI support.
2072 [so far only for SMDK2400 and TRAB boards]
2074 - Modem support enable:
2075 CONFIG_MODEM_SUPPORT
2077 - RTS/CTS Flow control enable:
2080 - Modem debug support:
2081 CONFIG_MODEM_SUPPORT_DEBUG
2083 Enables debugging stuff (char screen[1024], dbg())
2084 for modem support. Useful only with BDI2000.
2086 - Interrupt support (PPC):
2088 There are common interrupt_init() and timer_interrupt()
2089 for all PPC archs. interrupt_init() calls interrupt_init_cpu()
2090 for CPU specific initialization. interrupt_init_cpu()
2091 should set decrementer_count to appropriate value. If
2092 CPU resets decrementer automatically after interrupt
2093 (ppc4xx) it should set decrementer_count to zero.
2094 timer_interrupt() calls timer_interrupt_cpu() for CPU
2095 specific handling. If board has watchdog / status_led
2096 / other_activity_monitor it works automatically from
2097 general timer_interrupt().
2101 In the target system modem support is enabled when a
2102 specific key (key combination) is pressed during
2103 power-on. Otherwise U-Boot will boot normally
2104 (autoboot). The key_pressed() function is called from
2105 board_init(). Currently key_pressed() is a dummy
2106 function, returning 1 and thus enabling modem
2109 If there are no modem init strings in the
2110 environment, U-Boot proceed to autoboot; the
2111 previous output (banner, info printfs) will be
2114 See also: doc/README.Modem
2117 Configuration Settings:
2118 -----------------------
2120 - CONFIG_SYS_LONGHELP: Defined when you want long help messages included;
2121 undefine this when you're short of memory.
2123 - CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default
2124 width of the commands listed in the 'help' command output.
2126 - CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to
2127 prompt for user input.
2129 - CONFIG_SYS_CBSIZE: Buffer size for input from the Console
2131 - CONFIG_SYS_PBSIZE: Buffer size for Console output
2133 - CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands
2135 - CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to
2136 the application (usually a Linux kernel) when it is
2139 - CONFIG_SYS_BAUDRATE_TABLE:
2140 List of legal baudrate settings for this board.
2142 - CONFIG_SYS_CONSOLE_INFO_QUIET
2143 Suppress display of console information at boot.
2145 - CONFIG_SYS_CONSOLE_IS_IN_ENV
2146 If the board specific function
2147 extern int overwrite_console (void);
2148 returns 1, the stdin, stderr and stdout are switched to the
2149 serial port, else the settings in the environment are used.
2151 - CONFIG_SYS_CONSOLE_OVERWRITE_ROUTINE
2152 Enable the call to overwrite_console().
2154 - CONFIG_SYS_CONSOLE_ENV_OVERWRITE
2155 Enable overwrite of previous console environment settings.
2157 - CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END:
2158 Begin and End addresses of the area used by the
2161 - CONFIG_SYS_ALT_MEMTEST:
2162 Enable an alternate, more extensive memory test.
2164 - CONFIG_SYS_MEMTEST_SCRATCH:
2165 Scratch address used by the alternate memory test
2166 You only need to set this if address zero isn't writeable
2168 - CONFIG_SYS_MEM_TOP_HIDE (PPC only):
2169 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header,
2170 this specified memory area will get subtracted from the top
2171 (end) of RAM and won't get "touched" at all by U-Boot. By
2172 fixing up gd->ram_size the Linux kernel should gets passed
2173 the now "corrected" memory size and won't touch it either.
2174 This should work for arch/ppc and arch/powerpc. Only Linux
2175 board ports in arch/powerpc with bootwrapper support that
2176 recalculate the memory size from the SDRAM controller setup
2177 will have to get fixed in Linux additionally.
2179 This option can be used as a workaround for the 440EPx/GRx
2180 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't
2183 WARNING: Please make sure that this value is a multiple of
2184 the Linux page size (normally 4k). If this is not the case,
2185 then the end address of the Linux memory will be located at a
2186 non page size aligned address and this could cause major
2189 - CONFIG_SYS_TFTP_LOADADDR:
2190 Default load address for network file downloads
2192 - CONFIG_SYS_LOADS_BAUD_CHANGE:
2193 Enable temporary baudrate change while serial download
2195 - CONFIG_SYS_SDRAM_BASE:
2196 Physical start address of SDRAM. _Must_ be 0 here.
2198 - CONFIG_SYS_MBIO_BASE:
2199 Physical start address of Motherboard I/O (if using a
2202 - CONFIG_SYS_FLASH_BASE:
2203 Physical start address of Flash memory.
2205 - CONFIG_SYS_MONITOR_BASE:
2206 Physical start address of boot monitor code (set by
2207 make config files to be same as the text base address
2208 (TEXT_BASE) used when linking) - same as
2209 CONFIG_SYS_FLASH_BASE when booting from flash.
2211 - CONFIG_SYS_MONITOR_LEN:
2212 Size of memory reserved for monitor code, used to
2213 determine _at_compile_time_ (!) if the environment is
2214 embedded within the U-Boot image, or in a separate
2217 - CONFIG_SYS_MALLOC_LEN:
2218 Size of DRAM reserved for malloc() use.
2220 - CONFIG_SYS_BOOTM_LEN:
2221 Normally compressed uImages are limited to an
2222 uncompressed size of 8 MBytes. If this is not enough,
2223 you can define CONFIG_SYS_BOOTM_LEN in your board config file
2224 to adjust this setting to your needs.
2226 - CONFIG_SYS_BOOTMAPSZ:
2227 Maximum size of memory mapped by the startup code of
2228 the Linux kernel; all data that must be processed by
2229 the Linux kernel (bd_info, boot arguments, FDT blob if
2230 used) must be put below this limit, unless "bootm_low"
2231 enviroment variable is defined and non-zero. In such case
2232 all data for the Linux kernel must be between "bootm_low"
2233 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ.
2235 - CONFIG_SYS_MAX_FLASH_BANKS:
2236 Max number of Flash memory banks
2238 - CONFIG_SYS_MAX_FLASH_SECT:
2239 Max number of sectors on a Flash chip
2241 - CONFIG_SYS_FLASH_ERASE_TOUT:
2242 Timeout for Flash erase operations (in ms)
2244 - CONFIG_SYS_FLASH_WRITE_TOUT:
2245 Timeout for Flash write operations (in ms)
2247 - CONFIG_SYS_FLASH_LOCK_TOUT
2248 Timeout for Flash set sector lock bit operation (in ms)
2250 - CONFIG_SYS_FLASH_UNLOCK_TOUT
2251 Timeout for Flash clear lock bits operation (in ms)
2253 - CONFIG_SYS_FLASH_PROTECTION
2254 If defined, hardware flash sectors protection is used
2255 instead of U-Boot software protection.
2257 - CONFIG_SYS_DIRECT_FLASH_TFTP:
2259 Enable TFTP transfers directly to flash memory;
2260 without this option such a download has to be
2261 performed in two steps: (1) download to RAM, and (2)
2262 copy from RAM to flash.
2264 The two-step approach is usually more reliable, since
2265 you can check if the download worked before you erase
2266 the flash, but in some situations (when system RAM is
2267 too limited to allow for a temporary copy of the
2268 downloaded image) this option may be very useful.
2270 - CONFIG_SYS_FLASH_CFI:
2271 Define if the flash driver uses extra elements in the
2272 common flash structure for storing flash geometry.
2274 - CONFIG_FLASH_CFI_DRIVER
2275 This option also enables the building of the cfi_flash driver
2276 in the drivers directory
2278 - CONFIG_FLASH_CFI_MTD
2279 This option enables the building of the cfi_mtd driver
2280 in the drivers directory. The driver exports CFI flash
2283 - CONFIG_SYS_FLASH_USE_BUFFER_WRITE
2284 Use buffered writes to flash.
2286 - CONFIG_FLASH_SPANSION_S29WS_N
2287 s29ws-n MirrorBit flash has non-standard addresses for buffered
2290 - CONFIG_SYS_FLASH_QUIET_TEST
2291 If this option is defined, the common CFI flash doesn't
2292 print it's warning upon not recognized FLASH banks. This
2293 is useful, if some of the configured banks are only
2294 optionally available.
2296 - CONFIG_FLASH_SHOW_PROGRESS
2297 If defined (must be an integer), print out countdown
2298 digits and dots. Recommended value: 45 (9..1) for 80
2299 column displays, 15 (3..1) for 40 column displays.
2301 - CONFIG_SYS_RX_ETH_BUFFER:
2302 Defines the number of Ethernet receive buffers. On some
2303 Ethernet controllers it is recommended to set this value
2304 to 8 or even higher (EEPRO100 or 405 EMAC), since all
2305 buffers can be full shortly after enabling the interface
2306 on high Ethernet traffic.
2307 Defaults to 4 if not defined.
2309 The following definitions that deal with the placement and management
2310 of environment data (variable area); in general, we support the
2311 following configurations:
2313 - CONFIG_ENV_IS_IN_FLASH:
2315 Define this if the environment is in flash memory.
2317 a) The environment occupies one whole flash sector, which is
2318 "embedded" in the text segment with the U-Boot code. This
2319 happens usually with "bottom boot sector" or "top boot
2320 sector" type flash chips, which have several smaller
2321 sectors at the start or the end. For instance, such a
2322 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In
2323 such a case you would place the environment in one of the
2324 4 kB sectors - with U-Boot code before and after it. With
2325 "top boot sector" type flash chips, you would put the
2326 environment in one of the last sectors, leaving a gap
2327 between U-Boot and the environment.
2329 - CONFIG_ENV_OFFSET:
2331 Offset of environment data (variable area) to the
2332 beginning of flash memory; for instance, with bottom boot
2333 type flash chips the second sector can be used: the offset
2334 for this sector is given here.
2336 CONFIG_ENV_OFFSET is used relative to CONFIG_SYS_FLASH_BASE.
2340 This is just another way to specify the start address of
2341 the flash sector containing the environment (instead of
2344 - CONFIG_ENV_SECT_SIZE:
2346 Size of the sector containing the environment.
2349 b) Sometimes flash chips have few, equal sized, BIG sectors.
2350 In such a case you don't want to spend a whole sector for
2355 If you use this in combination with CONFIG_ENV_IS_IN_FLASH
2356 and CONFIG_ENV_SECT_SIZE, you can specify to use only a part
2357 of this flash sector for the environment. This saves
2358 memory for the RAM copy of the environment.
2360 It may also save flash memory if you decide to use this
2361 when your environment is "embedded" within U-Boot code,
2362 since then the remainder of the flash sector could be used
2363 for U-Boot code. It should be pointed out that this is
2364 STRONGLY DISCOURAGED from a robustness point of view:
2365 updating the environment in flash makes it always
2366 necessary to erase the WHOLE sector. If something goes
2367 wrong before the contents has been restored from a copy in
2368 RAM, your target system will be dead.
2370 - CONFIG_ENV_ADDR_REDUND
2371 CONFIG_ENV_SIZE_REDUND
2373 These settings describe a second storage area used to hold
2374 a redundant copy of the environment data, so that there is
2375 a valid backup copy in case there is a power failure during
2376 a "saveenv" operation.
2378 BE CAREFUL! Any changes to the flash layout, and some changes to the
2379 source code will make it necessary to adapt <board>/u-boot.lds*
2383 - CONFIG_ENV_IS_IN_NVRAM:
2385 Define this if you have some non-volatile memory device
2386 (NVRAM, battery buffered SRAM) which you want to use for the
2392 These two #defines are used to determine the memory area you
2393 want to use for environment. It is assumed that this memory
2394 can just be read and written to, without any special
2397 BE CAREFUL! The first access to the environment happens quite early
2398 in U-Boot initalization (when we try to get the setting of for the
2399 console baudrate). You *MUST* have mapped your NVRAM area then, or
2402 Please note that even with NVRAM we still use a copy of the
2403 environment in RAM: we could work on NVRAM directly, but we want to
2404 keep settings there always unmodified except somebody uses "saveenv"
2405 to save the current settings.
2408 - CONFIG_ENV_IS_IN_EEPROM:
2410 Use this if you have an EEPROM or similar serial access
2411 device and a driver for it.
2413 - CONFIG_ENV_OFFSET:
2416 These two #defines specify the offset and size of the
2417 environment area within the total memory of your EEPROM.
2419 - CONFIG_SYS_I2C_EEPROM_ADDR:
2420 If defined, specified the chip address of the EEPROM device.
2421 The default address is zero.
2423 - CONFIG_SYS_EEPROM_PAGE_WRITE_BITS:
2424 If defined, the number of bits used to address bytes in a
2425 single page in the EEPROM device. A 64 byte page, for example
2426 would require six bits.
2428 - CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS:
2429 If defined, the number of milliseconds to delay between
2430 page writes. The default is zero milliseconds.
2432 - CONFIG_SYS_I2C_EEPROM_ADDR_LEN:
2433 The length in bytes of the EEPROM memory array address. Note
2434 that this is NOT the chip address length!
2436 - CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW:
2437 EEPROM chips that implement "address overflow" are ones
2438 like Catalyst 24WC04/08/16 which has 9/10/11 bits of
2439 address and the extra bits end up in the "chip address" bit
2440 slots. This makes a 24WC08 (1Kbyte) chip look like four 256
2443 Note that we consider the length of the address field to
2444 still be one byte because the extra address bits are hidden
2445 in the chip address.
2447 - CONFIG_SYS_EEPROM_SIZE:
2448 The size in bytes of the EEPROM device.
2450 - CONFIG_ENV_EEPROM_IS_ON_I2C
2451 define this, if you have I2C and SPI activated, and your
2452 EEPROM, which holds the environment, is on the I2C bus.
2454 - CONFIG_I2C_ENV_EEPROM_BUS
2455 if you have an Environment on an EEPROM reached over
2456 I2C muxes, you can define here, how to reach this
2457 EEPROM. For example:
2459 #define CONFIG_I2C_ENV_EEPROM_BUS "pca9547:70:d\0"
2461 EEPROM which holds the environment, is reached over
2462 a pca9547 i2c mux with address 0x70, channel 3.
2464 - CONFIG_ENV_IS_IN_DATAFLASH:
2466 Define this if you have a DataFlash memory device which you
2467 want to use for the environment.
2469 - CONFIG_ENV_OFFSET:
2473 These three #defines specify the offset and size of the
2474 environment area within the total memory of your DataFlash placed
2475 at the specified address.
2477 - CONFIG_ENV_IS_IN_NAND:
2479 Define this if you have a NAND device which you want to use
2480 for the environment.
2482 - CONFIG_ENV_OFFSET:
2485 These two #defines specify the offset and size of the environment
2486 area within the first NAND device.
2488 - CONFIG_ENV_OFFSET_REDUND
2490 This setting describes a second storage area of CONFIG_ENV_SIZE
2491 size used to hold a redundant copy of the environment data,
2492 so that there is a valid backup copy in case there is a
2493 power failure during a "saveenv" operation.
2495 Note: CONFIG_ENV_OFFSET and CONFIG_ENV_OFFSET_REDUND must be aligned
2496 to a block boundary, and CONFIG_ENV_SIZE must be a multiple of
2497 the NAND devices block size.
2499 - CONFIG_NAND_ENV_DST
2501 Defines address in RAM to which the nand_spl code should copy the
2502 environment. If redundant environment is used, it will be copied to
2503 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE.
2505 - CONFIG_SYS_SPI_INIT_OFFSET
2507 Defines offset to the initial SPI buffer area in DPRAM. The
2508 area is used at an early stage (ROM part) if the environment
2509 is configured to reside in the SPI EEPROM: We need a 520 byte
2510 scratch DPRAM area. It is used between the two initialization
2511 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems
2512 to be a good choice since it makes it far enough from the
2513 start of the data area as well as from the stack pointer.
2515 Please note that the environment is read-only until the monitor
2516 has been relocated to RAM and a RAM copy of the environment has been
2517 created; also, when using EEPROM you will have to use getenv_r()
2518 until then to read environment variables.
2520 The environment is protected by a CRC32 checksum. Before the monitor
2521 is relocated into RAM, as a result of a bad CRC you will be working
2522 with the compiled-in default environment - *silently*!!! [This is
2523 necessary, because the first environment variable we need is the
2524 "baudrate" setting for the console - if we have a bad CRC, we don't
2525 have any device yet where we could complain.]
2527 Note: once the monitor has been relocated, then it will complain if
2528 the default environment is used; a new CRC is computed as soon as you
2529 use the "saveenv" command to store a valid environment.
2531 - CONFIG_SYS_FAULT_ECHO_LINK_DOWN:
2532 Echo the inverted Ethernet link state to the fault LED.
2534 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR
2535 also needs to be defined.
2537 - CONFIG_SYS_FAULT_MII_ADDR:
2538 MII address of the PHY to check for the Ethernet link state.
2540 - CONFIG_NS16550_MIN_FUNCTIONS:
2541 Define this if you desire to only have use of the NS16550_init
2542 and NS16550_putc functions for the serial driver located at
2543 drivers/serial/ns16550.c. This option is useful for saving
2544 space for already greatly restricted images, including but not
2545 limited to NAND_SPL configurations.
2547 Low Level (hardware related) configuration options:
2548 ---------------------------------------------------
2550 - CONFIG_SYS_CACHELINE_SIZE:
2551 Cache Line Size of the CPU.
2553 - CONFIG_SYS_DEFAULT_IMMR:
2554 Default address of the IMMR after system reset.
2556 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU,
2557 and RPXsuper) to be able to adjust the position of
2558 the IMMR register after a reset.
2560 - Floppy Disk Support:
2561 CONFIG_SYS_FDC_DRIVE_NUMBER
2563 the default drive number (default value 0)
2565 CONFIG_SYS_ISA_IO_STRIDE
2567 defines the spacing between FDC chipset registers
2570 CONFIG_SYS_ISA_IO_OFFSET
2572 defines the offset of register from address. It
2573 depends on which part of the data bus is connected to
2574 the FDC chipset. (default value 0)
2576 If CONFIG_SYS_ISA_IO_STRIDE CONFIG_SYS_ISA_IO_OFFSET and
2577 CONFIG_SYS_FDC_DRIVE_NUMBER are undefined, they take their
2580 if CONFIG_SYS_FDC_HW_INIT is defined, then the function
2581 fdc_hw_init() is called at the beginning of the FDC
2582 setup. fdc_hw_init() must be provided by the board
2583 source code. It is used to make hardware dependant
2586 - CONFIG_SYS_IMMR: Physical address of the Internal Memory.
2587 DO NOT CHANGE unless you know exactly what you're
2588 doing! (11-4) [MPC8xx/82xx systems only]
2590 - CONFIG_SYS_INIT_RAM_ADDR:
2592 Start address of memory area that can be used for
2593 initial data and stack; please note that this must be
2594 writable memory that is working WITHOUT special
2595 initialization, i. e. you CANNOT use normal RAM which
2596 will become available only after programming the
2597 memory controller and running certain initialization
2600 U-Boot uses the following memory types:
2601 - MPC8xx and MPC8260: IMMR (internal memory of the CPU)
2602 - MPC824X: data cache
2603 - PPC4xx: data cache
2605 - CONFIG_SYS_GBL_DATA_OFFSET:
2607 Offset of the initial data structure in the memory
2608 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually
2609 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial
2610 data is located at the end of the available space
2611 (sometimes written as (CONFIG_SYS_INIT_RAM_END -
2612 CONFIG_SYS_INIT_DATA_SIZE), and the initial stack is just
2613 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR +
2614 CONFIG_SYS_GBL_DATA_OFFSET) downward.
2617 On the MPC824X (or other systems that use the data
2618 cache for initial memory) the address chosen for
2619 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must
2620 point to an otherwise UNUSED address space between
2621 the top of RAM and the start of the PCI space.
2623 - CONFIG_SYS_SIUMCR: SIU Module Configuration (11-6)
2625 - CONFIG_SYS_SYPCR: System Protection Control (11-9)
2627 - CONFIG_SYS_TBSCR: Time Base Status and Control (11-26)
2629 - CONFIG_SYS_PISCR: Periodic Interrupt Status and Control (11-31)
2631 - CONFIG_SYS_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30)
2633 - CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27)
2635 - CONFIG_SYS_OR_TIMING_SDRAM:
2638 - CONFIG_SYS_MAMR_PTA:
2639 periodic timer for refresh
2641 - CONFIG_SYS_DER: Debug Event Register (37-47)
2643 - FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM,
2644 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP,
2645 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM,
2646 CONFIG_SYS_BR1_PRELIM:
2647 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
2649 - SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
2650 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM,
2651 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM:
2652 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
2654 - CONFIG_SYS_MAMR_PTA, CONFIG_SYS_MPTPR_2BK_4K, CONFIG_SYS_MPTPR_1BK_4K, CONFIG_SYS_MPTPR_2BK_8K,
2655 CONFIG_SYS_MPTPR_1BK_8K, CONFIG_SYS_MAMR_8COL, CONFIG_SYS_MAMR_9COL:
2656 Machine Mode Register and Memory Periodic Timer
2657 Prescaler definitions (SDRAM timing)
2659 - CONFIG_SYS_I2C_UCODE_PATCH, CONFIG_SYS_I2C_DPMEM_OFFSET [0x1FC0]:
2660 enable I2C microcode relocation patch (MPC8xx);
2661 define relocation offset in DPRAM [DSP2]
2663 - CONFIG_SYS_SMC_UCODE_PATCH, CONFIG_SYS_SMC_DPMEM_OFFSET [0x1FC0]:
2664 enable SMC microcode relocation patch (MPC8xx);
2665 define relocation offset in DPRAM [SMC1]
2667 - CONFIG_SYS_SPI_UCODE_PATCH, CONFIG_SYS_SPI_DPMEM_OFFSET [0x1FC0]:
2668 enable SPI microcode relocation patch (MPC8xx);
2669 define relocation offset in DPRAM [SCC4]
2671 - CONFIG_SYS_USE_OSCCLK:
2672 Use OSCM clock mode on MBX8xx board. Be careful,
2673 wrong setting might damage your board. Read
2674 doc/README.MBX before setting this variable!
2676 - CONFIG_SYS_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only)
2677 Offset of the bootmode word in DPRAM used by post
2678 (Power On Self Tests). This definition overrides
2679 #define'd default value in commproc.h resp.
2682 - CONFIG_SYS_PCI_SLV_MEM_LOCAL, CONFIG_SYS_PCI_SLV_MEM_BUS, CONFIG_SYS_PICMR0_MASK_ATTRIB,
2683 CONFIG_SYS_PCI_MSTR0_LOCAL, CONFIG_SYS_PCIMSK0_MASK, CONFIG_SYS_PCI_MSTR1_LOCAL,
2684 CONFIG_SYS_PCIMSK1_MASK, CONFIG_SYS_PCI_MSTR_MEM_LOCAL, CONFIG_SYS_PCI_MSTR_MEM_BUS,
2685 CONFIG_SYS_CPU_PCI_MEM_START, CONFIG_SYS_PCI_MSTR_MEM_SIZE, CONFIG_SYS_POCMR0_MASK_ATTRIB,
2686 CONFIG_SYS_PCI_MSTR_MEMIO_LOCAL, CONFIG_SYS_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START,
2687 CONFIG_SYS_PCI_MSTR_MEMIO_SIZE, CONFIG_SYS_POCMR1_MASK_ATTRIB, CONFIG_SYS_PCI_MSTR_IO_LOCAL,
2688 CONFIG_SYS_PCI_MSTR_IO_BUS, CONFIG_SYS_CPU_PCI_IO_START, CONFIG_SYS_PCI_MSTR_IO_SIZE,
2689 CONFIG_SYS_POCMR2_MASK_ATTRIB: (MPC826x only)
2690 Overrides the default PCI memory map in cpu/mpc8260/pci.c if set.
2692 - CONFIG_PCI_DISABLE_PCIE:
2693 Disable PCI-Express on systems where it is supported but not
2697 Get DDR timing information from an I2C EEPROM. Common
2698 with pluggable memory modules such as SODIMMs
2701 I2C address of the SPD EEPROM
2703 - CONFIG_SYS_SPD_BUS_NUM
2704 If SPD EEPROM is on an I2C bus other than the first
2705 one, specify here. Note that the value must resolve
2706 to something your driver can deal with.
2708 - CONFIG_SYS_83XX_DDR_USES_CS0
2709 Only for 83xx systems. If specified, then DDR should
2710 be configured using CS0 and CS1 instead of CS2 and CS3.
2712 - CONFIG_ETHER_ON_FEC[12]
2713 Define to enable FEC[12] on a 8xx series processor.
2715 - CONFIG_FEC[12]_PHY
2716 Define to the hardcoded PHY address which corresponds
2717 to the given FEC; i. e.
2718 #define CONFIG_FEC1_PHY 4
2719 means that the PHY with address 4 is connected to FEC1
2721 When set to -1, means to probe for first available.
2723 - CONFIG_FEC[12]_PHY_NORXERR
2724 The PHY does not have a RXERR line (RMII only).
2725 (so program the FEC to ignore it).
2728 Enable RMII mode for all FECs.
2729 Note that this is a global option, we can't
2730 have one FEC in standard MII mode and another in RMII mode.
2732 - CONFIG_CRC32_VERIFY
2733 Add a verify option to the crc32 command.
2736 => crc32 -v <address> <count> <crc32>
2738 Where address/count indicate a memory area
2739 and crc32 is the correct crc32 which the
2743 Add the "loopw" memory command. This only takes effect if
2744 the memory commands are activated globally (CONFIG_CMD_MEM).
2747 Add the "mdc" and "mwc" memory commands. These are cyclic
2752 This command will print 4 bytes (10,11,12,13) each 500 ms.
2754 => mwc.l 100 12345678 10
2755 This command will write 12345678 to address 100 all 10 ms.
2757 This only takes effect if the memory commands are activated
2758 globally (CONFIG_CMD_MEM).
2760 - CONFIG_SKIP_LOWLEVEL_INIT
2761 - CONFIG_SKIP_RELOCATE_UBOOT
2763 [ARM only] If these variables are defined, then
2764 certain low level initializations (like setting up
2765 the memory controller) are omitted and/or U-Boot does
2766 not relocate itself into RAM.
2767 Normally these variables MUST NOT be defined. The
2768 only exception is when U-Boot is loaded (to RAM) by
2769 some other boot loader or by a debugger which
2770 performs these initializations itself.
2774 Modifies the behaviour of start.S when compiling a loader
2775 that is executed before the actual U-Boot. E.g. when
2776 compiling a NAND SPL.
2778 Building the Software:
2779 ======================
2781 Building U-Boot has been tested in several native build environments
2782 and in many different cross environments. Of course we cannot support
2783 all possibly existing versions of cross development tools in all
2784 (potentially obsolete) versions. In case of tool chain problems we
2785 recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK)
2786 which is extensively used to build and test U-Boot.
2788 If you are not using a native environment, it is assumed that you
2789 have GNU cross compiling tools available in your path. In this case,
2790 you must set the environment variable CROSS_COMPILE in your shell.
2791 Note that no changes to the Makefile or any other source files are
2792 necessary. For example using the ELDK on a 4xx CPU, please enter:
2794 $ CROSS_COMPILE=ppc_4xx-
2795 $ export CROSS_COMPILE
2797 Note: If you wish to generate Windows versions of the utilities in
2798 the tools directory you can use the MinGW toolchain
2799 (http://www.mingw.org). Set your HOST tools to the MinGW
2800 toolchain and execute 'make tools'. For example:
2802 $ make HOSTCC=i586-mingw32msvc-gcc HOSTSTRIP=i586-mingw32msvc-strip tools
2804 Binaries such as tools/mkimage.exe will be created which can
2805 be executed on computers running Windows.
2807 U-Boot is intended to be simple to build. After installing the
2808 sources you must configure U-Boot for one specific board type. This
2813 where "NAME_config" is the name of one of the existing configu-
2814 rations; see the main Makefile for supported names.
2816 Note: for some board special configuration names may exist; check if
2817 additional information is available from the board vendor; for
2818 instance, the TQM823L systems are available without (standard)
2819 or with LCD support. You can select such additional "features"
2820 when choosing the configuration, i. e.
2823 - will configure for a plain TQM823L, i. e. no LCD support
2825 make TQM823L_LCD_config
2826 - will configure for a TQM823L with U-Boot console on LCD
2831 Finally, type "make all", and you should get some working U-Boot
2832 images ready for download to / installation on your system:
2834 - "u-boot.bin" is a raw binary image
2835 - "u-boot" is an image in ELF binary format
2836 - "u-boot.srec" is in Motorola S-Record format
2838 By default the build is performed locally and the objects are saved
2839 in the source directory. One of the two methods can be used to change
2840 this behavior and build U-Boot to some external directory:
2842 1. Add O= to the make command line invocations:
2844 make O=/tmp/build distclean
2845 make O=/tmp/build NAME_config
2846 make O=/tmp/build all
2848 2. Set environment variable BUILD_DIR to point to the desired location:
2850 export BUILD_DIR=/tmp/build
2855 Note that the command line "O=" setting overrides the BUILD_DIR environment
2859 Please be aware that the Makefiles assume you are using GNU make, so
2860 for instance on NetBSD you might need to use "gmake" instead of
2864 If the system board that you have is not listed, then you will need
2865 to port U-Boot to your hardware platform. To do this, follow these
2868 1. Add a new configuration option for your board to the toplevel
2869 "Makefile" and to the "MAKEALL" script, using the existing
2870 entries as examples. Note that here and at many other places
2871 boards and other names are listed in alphabetical sort order. Please
2873 2. Create a new directory to hold your board specific code. Add any
2874 files you need. In your board directory, you will need at least
2875 the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds".
2876 3. Create a new configuration file "include/configs/<board>.h" for
2878 3. If you're porting U-Boot to a new CPU, then also create a new
2879 directory to hold your CPU specific code. Add any files you need.
2880 4. Run "make <board>_config" with your new name.
2881 5. Type "make", and you should get a working "u-boot.srec" file
2882 to be installed on your target system.
2883 6. Debug and solve any problems that might arise.
2884 [Of course, this last step is much harder than it sounds.]
2887 Testing of U-Boot Modifications, Ports to New Hardware, etc.:
2888 ==============================================================
2890 If you have modified U-Boot sources (for instance added a new board
2891 or support for new devices, a new CPU, etc.) you are expected to
2892 provide feedback to the other developers. The feedback normally takes
2893 the form of a "patch", i. e. a context diff against a certain (latest
2894 official or latest in the git repository) version of U-Boot sources.
2896 But before you submit such a patch, please verify that your modifi-
2897 cation did not break existing code. At least make sure that *ALL* of
2898 the supported boards compile WITHOUT ANY compiler warnings. To do so,
2899 just run the "MAKEALL" script, which will configure and build U-Boot
2900 for ALL supported system. Be warned, this will take a while. You can
2901 select which (cross) compiler to use by passing a `CROSS_COMPILE'
2902 environment variable to the script, i. e. to use the ELDK cross tools
2905 CROSS_COMPILE=ppc_8xx- MAKEALL
2907 or to build on a native PowerPC system you can type
2909 CROSS_COMPILE=' ' MAKEALL
2911 When using the MAKEALL script, the default behaviour is to build
2912 U-Boot in the source directory. This location can be changed by
2913 setting the BUILD_DIR environment variable. Also, for each target
2914 built, the MAKEALL script saves two log files (<target>.ERR and
2915 <target>.MAKEALL) in the <source dir>/LOG directory. This default
2916 location can be changed by setting the MAKEALL_LOGDIR environment
2917 variable. For example:
2919 export BUILD_DIR=/tmp/build
2920 export MAKEALL_LOGDIR=/tmp/log
2921 CROSS_COMPILE=ppc_8xx- MAKEALL
2923 With the above settings build objects are saved in the /tmp/build,
2924 log files are saved in the /tmp/log and the source tree remains clean
2925 during the whole build process.
2928 See also "U-Boot Porting Guide" below.
2931 Monitor Commands - Overview:
2932 ============================
2934 go - start application at address 'addr'
2935 run - run commands in an environment variable
2936 bootm - boot application image from memory
2937 bootp - boot image via network using BootP/TFTP protocol
2938 tftpboot- boot image via network using TFTP protocol
2939 and env variables "ipaddr" and "serverip"
2940 (and eventually "gatewayip")
2941 rarpboot- boot image via network using RARP/TFTP protocol
2942 diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
2943 loads - load S-Record file over serial line
2944 loadb - load binary file over serial line (kermit mode)
2946 mm - memory modify (auto-incrementing)
2947 nm - memory modify (constant address)
2948 mw - memory write (fill)
2950 cmp - memory compare
2951 crc32 - checksum calculation
2952 i2c - I2C sub-system
2953 sspi - SPI utility commands
2954 base - print or set address offset
2955 printenv- print environment variables
2956 setenv - set environment variables
2957 saveenv - save environment variables to persistent storage
2958 protect - enable or disable FLASH write protection
2959 erase - erase FLASH memory
2960 flinfo - print FLASH memory information
2961 bdinfo - print Board Info structure
2962 iminfo - print header information for application image
2963 coninfo - print console devices and informations
2964 ide - IDE sub-system
2965 loop - infinite loop on address range
2966 loopw - infinite write loop on address range
2967 mtest - simple RAM test
2968 icache - enable or disable instruction cache
2969 dcache - enable or disable data cache
2970 reset - Perform RESET of the CPU
2971 echo - echo args to console
2972 version - print monitor version
2973 help - print online help
2974 ? - alias for 'help'
2977 Monitor Commands - Detailed Description:
2978 ========================================
2982 For now: just type "help <command>".
2985 Environment Variables:
2986 ======================
2988 U-Boot supports user configuration using Environment Variables which
2989 can be made persistent by saving to Flash memory.
2991 Environment Variables are set using "setenv", printed using
2992 "printenv", and saved to Flash using "saveenv". Using "setenv"
2993 without a value can be used to delete a variable from the
2994 environment. As long as you don't save the environment you are
2995 working with an in-memory copy. In case the Flash area containing the
2996 environment is erased by accident, a default environment is provided.
2998 Some configuration options can be set using Environment Variables:
3000 baudrate - see CONFIG_BAUDRATE
3002 bootdelay - see CONFIG_BOOTDELAY
3004 bootcmd - see CONFIG_BOOTCOMMAND
3006 bootargs - Boot arguments when booting an RTOS image
3008 bootfile - Name of the image to load with TFTP
3010 bootm_low - Memory range available for image processing in the bootm
3011 command can be restricted. This variable is given as
3012 a hexadecimal number and defines lowest address allowed
3013 for use by the bootm command. See also "bootm_size"
3014 environment variable. Address defined by "bootm_low" is
3015 also the base of the initial memory mapping for the Linux
3016 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ.
3018 bootm_size - Memory range available for image processing in the bootm
3019 command can be restricted. This variable is given as
3020 a hexadecimal number and defines the size of the region
3021 allowed for use by the bootm command. See also "bootm_low"
3022 environment variable.
3024 updatefile - Location of the software update file on a TFTP server, used
3025 by the automatic software update feature. Please refer to
3026 documentation in doc/README.update for more details.
3028 autoload - if set to "no" (any string beginning with 'n'),
3029 "bootp" will just load perform a lookup of the
3030 configuration from the BOOTP server, but not try to
3031 load any image using TFTP
3033 autostart - if set to "yes", an image loaded using the "bootp",
3034 "rarpboot", "tftpboot" or "diskboot" commands will
3035 be automatically started (by internally calling
3038 If set to "no", a standalone image passed to the
3039 "bootm" command will be copied to the load address
3040 (and eventually uncompressed), but NOT be started.
3041 This can be used to load and uncompress arbitrary
3044 i2cfast - (PPC405GP|PPC405EP only)
3045 if set to 'y' configures Linux I2C driver for fast
3046 mode (400kHZ). This environment variable is used in
3047 initialization code. So, for changes to be effective
3048 it must be saved and board must be reset.
3050 initrd_high - restrict positioning of initrd images:
3051 If this variable is not set, initrd images will be
3052 copied to the highest possible address in RAM; this
3053 is usually what you want since it allows for
3054 maximum initrd size. If for some reason you want to
3055 make sure that the initrd image is loaded below the
3056 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment
3057 variable to a value of "no" or "off" or "0".
3058 Alternatively, you can set it to a maximum upper
3059 address to use (U-Boot will still check that it
3060 does not overwrite the U-Boot stack and data).
3062 For instance, when you have a system with 16 MB
3063 RAM, and want to reserve 4 MB from use by Linux,
3064 you can do this by adding "mem=12M" to the value of
3065 the "bootargs" variable. However, now you must make
3066 sure that the initrd image is placed in the first
3067 12 MB as well - this can be done with
3069 setenv initrd_high 00c00000
3071 If you set initrd_high to 0xFFFFFFFF, this is an
3072 indication to U-Boot that all addresses are legal
3073 for the Linux kernel, including addresses in flash
3074 memory. In this case U-Boot will NOT COPY the
3075 ramdisk at all. This may be useful to reduce the
3076 boot time on your system, but requires that this
3077 feature is supported by your Linux kernel.
3079 ipaddr - IP address; needed for tftpboot command
3081 loadaddr - Default load address for commands like "bootp",
3082 "rarpboot", "tftpboot", "loadb" or "diskboot"
3084 loads_echo - see CONFIG_LOADS_ECHO
3086 serverip - TFTP server IP address; needed for tftpboot command
3088 bootretry - see CONFIG_BOOT_RETRY_TIME
3090 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
3092 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
3094 ethprime - When CONFIG_NET_MULTI is enabled controls which
3095 interface is used first.
3097 ethact - When CONFIG_NET_MULTI is enabled controls which
3098 interface is currently active. For example you
3099 can do the following
3101 => setenv ethact FEC ETHERNET
3102 => ping 192.168.0.1 # traffic sent on FEC ETHERNET
3103 => setenv ethact SCC ETHERNET
3104 => ping 10.0.0.1 # traffic sent on SCC ETHERNET
3106 ethrotate - When set to "no" U-Boot does not go through all
3107 available network interfaces.
3108 It just stays at the currently selected interface.
3110 netretry - When set to "no" each network operation will
3111 either succeed or fail without retrying.
3112 When set to "once" the network operation will
3113 fail when all the available network interfaces
3114 are tried once without success.
3115 Useful on scripts which control the retry operation
3118 npe_ucode - set load address for the NPE microcode
3120 tftpsrcport - If this is set, the value is used for TFTP's
3123 tftpdstport - If this is set, the value is used for TFTP's UDP
3124 destination port instead of the Well Know Port 69.
3126 vlan - When set to a value < 4095 the traffic over
3127 Ethernet is encapsulated/received over 802.1q
3130 The following environment variables may be used and automatically
3131 updated by the network boot commands ("bootp" and "rarpboot"),
3132 depending the information provided by your boot server:
3134 bootfile - see above
3135 dnsip - IP address of your Domain Name Server
3136 dnsip2 - IP address of your secondary Domain Name Server
3137 gatewayip - IP address of the Gateway (Router) to use
3138 hostname - Target hostname
3140 netmask - Subnet Mask
3141 rootpath - Pathname of the root filesystem on the NFS server
3142 serverip - see above
3145 There are two special Environment Variables:
3147 serial# - contains hardware identification information such
3148 as type string and/or serial number
3149 ethaddr - Ethernet address
3151 These variables can be set only once (usually during manufacturing of
3152 the board). U-Boot refuses to delete or overwrite these variables
3153 once they have been set once.
3156 Further special Environment Variables:
3158 ver - Contains the U-Boot version string as printed
3159 with the "version" command. This variable is
3160 readonly (see CONFIG_VERSION_VARIABLE).
3163 Please note that changes to some configuration parameters may take
3164 only effect after the next boot (yes, that's just like Windoze :-).
3167 Command Line Parsing:
3168 =====================
3170 There are two different command line parsers available with U-Boot:
3171 the old "simple" one, and the much more powerful "hush" shell:
3173 Old, simple command line parser:
3174 --------------------------------
3176 - supports environment variables (through setenv / saveenv commands)
3177 - several commands on one line, separated by ';'
3178 - variable substitution using "... ${name} ..." syntax
3179 - special characters ('$', ';') can be escaped by prefixing with '\',
3181 setenv bootcmd bootm \${address}
3182 - You can also escape text by enclosing in single apostrophes, for example:
3183 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
3188 - similar to Bourne shell, with control structures like
3189 if...then...else...fi, for...do...done; while...do...done,
3190 until...do...done, ...
3191 - supports environment ("global") variables (through setenv / saveenv
3192 commands) and local shell variables (through standard shell syntax
3193 "name=value"); only environment variables can be used with "run"
3199 (1) If a command line (or an environment variable executed by a "run"
3200 command) contains several commands separated by semicolon, and
3201 one of these commands fails, then the remaining commands will be
3204 (2) If you execute several variables with one call to run (i. e.
3205 calling run with a list of variables as arguments), any failing
3206 command will cause "run" to terminate, i. e. the remaining
3207 variables are not executed.
3209 Note for Redundant Ethernet Interfaces:
3210 =======================================
3212 Some boards come with redundant Ethernet interfaces; U-Boot supports
3213 such configurations and is capable of automatic selection of a
3214 "working" interface when needed. MAC assignment works as follows:
3216 Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
3217 MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
3218 "eth1addr" (=>eth1), "eth2addr", ...
3220 If the network interface stores some valid MAC address (for instance
3221 in SROM), this is used as default address if there is NO correspon-
3222 ding setting in the environment; if the corresponding environment
3223 variable is set, this overrides the settings in the card; that means:
3225 o If the SROM has a valid MAC address, and there is no address in the
3226 environment, the SROM's address is used.
3228 o If there is no valid address in the SROM, and a definition in the
3229 environment exists, then the value from the environment variable is
3232 o If both the SROM and the environment contain a MAC address, and
3233 both addresses are the same, this MAC address is used.
3235 o If both the SROM and the environment contain a MAC address, and the
3236 addresses differ, the value from the environment is used and a
3239 o If neither SROM nor the environment contain a MAC address, an error
3246 U-Boot is capable of booting (and performing other auxiliary operations on)
3247 images in two formats:
3249 New uImage format (FIT)
3250 -----------------------
3252 Flexible and powerful format based on Flattened Image Tree -- FIT (similar
3253 to Flattened Device Tree). It allows the use of images with multiple
3254 components (several kernels, ramdisks, etc.), with contents protected by
3255 SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory.
3261 Old image format is based on binary files which can be basically anything,
3262 preceded by a special header; see the definitions in include/image.h for
3263 details; basically, the header defines the following image properties:
3265 * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
3266 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
3267 LynxOS, pSOS, QNX, RTEMS, INTEGRITY;
3268 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS,
3270 * Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86,
3271 IA64, MIPS, NIOS, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
3272 Currently supported: ARM, AVR32, Intel x86, MIPS, NIOS, PowerPC).
3273 * Compression Type (uncompressed, gzip, bzip2)
3279 The header is marked by a special Magic Number, and both the header
3280 and the data portions of the image are secured against corruption by
3287 Although U-Boot should support any OS or standalone application
3288 easily, the main focus has always been on Linux during the design of
3291 U-Boot includes many features that so far have been part of some
3292 special "boot loader" code within the Linux kernel. Also, any
3293 "initrd" images to be used are no longer part of one big Linux image;
3294 instead, kernel and "initrd" are separate images. This implementation
3295 serves several purposes:
3297 - the same features can be used for other OS or standalone
3298 applications (for instance: using compressed images to reduce the
3299 Flash memory footprint)
3301 - it becomes much easier to port new Linux kernel versions because
3302 lots of low-level, hardware dependent stuff are done by U-Boot
3304 - the same Linux kernel image can now be used with different "initrd"
3305 images; of course this also means that different kernel images can
3306 be run with the same "initrd". This makes testing easier (you don't
3307 have to build a new "zImage.initrd" Linux image when you just
3308 change a file in your "initrd"). Also, a field-upgrade of the
3309 software is easier now.
3315 Porting Linux to U-Boot based systems:
3316 ---------------------------------------
3318 U-Boot cannot save you from doing all the necessary modifications to
3319 configure the Linux device drivers for use with your target hardware
3320 (no, we don't intend to provide a full virtual machine interface to
3323 But now you can ignore ALL boot loader code (in arch/ppc/mbxboot).
3325 Just make sure your machine specific header file (for instance
3326 include/asm-ppc/tqm8xx.h) includes the same definition of the Board
3327 Information structure as we define in include/asm-<arch>/u-boot.h,
3328 and make sure that your definition of IMAP_ADDR uses the same value
3329 as your U-Boot configuration in CONFIG_SYS_IMMR.
3332 Configuring the Linux kernel:
3333 -----------------------------
3335 No specific requirements for U-Boot. Make sure you have some root
3336 device (initial ramdisk, NFS) for your target system.
3339 Building a Linux Image:
3340 -----------------------
3342 With U-Boot, "normal" build targets like "zImage" or "bzImage" are
3343 not used. If you use recent kernel source, a new build target
3344 "uImage" will exist which automatically builds an image usable by
3345 U-Boot. Most older kernels also have support for a "pImage" target,
3346 which was introduced for our predecessor project PPCBoot and uses a
3347 100% compatible format.
3356 The "uImage" build target uses a special tool (in 'tools/mkimage') to
3357 encapsulate a compressed Linux kernel image with header information,
3358 CRC32 checksum etc. for use with U-Boot. This is what we are doing:
3360 * build a standard "vmlinux" kernel image (in ELF binary format):
3362 * convert the kernel into a raw binary image:
3364 ${CROSS_COMPILE}-objcopy -O binary \
3365 -R .note -R .comment \
3366 -S vmlinux linux.bin
3368 * compress the binary image:
3372 * package compressed binary image for U-Boot:
3374 mkimage -A ppc -O linux -T kernel -C gzip \
3375 -a 0 -e 0 -n "Linux Kernel Image" \
3376 -d linux.bin.gz uImage
3379 The "mkimage" tool can also be used to create ramdisk images for use
3380 with U-Boot, either separated from the Linux kernel image, or
3381 combined into one file. "mkimage" encapsulates the images with a 64
3382 byte header containing information about target architecture,
3383 operating system, image type, compression method, entry points, time
3384 stamp, CRC32 checksums, etc.
3386 "mkimage" can be called in two ways: to verify existing images and
3387 print the header information, or to build new images.
3389 In the first form (with "-l" option) mkimage lists the information
3390 contained in the header of an existing U-Boot image; this includes
3391 checksum verification:
3393 tools/mkimage -l image
3394 -l ==> list image header information
3396 The second form (with "-d" option) is used to build a U-Boot image
3397 from a "data file" which is used as image payload:
3399 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
3400 -n name -d data_file image
3401 -A ==> set architecture to 'arch'
3402 -O ==> set operating system to 'os'
3403 -T ==> set image type to 'type'
3404 -C ==> set compression type 'comp'
3405 -a ==> set load address to 'addr' (hex)
3406 -e ==> set entry point to 'ep' (hex)
3407 -n ==> set image name to 'name'
3408 -d ==> use image data from 'datafile'
3410 Right now, all Linux kernels for PowerPC systems use the same load
3411 address (0x00000000), but the entry point address depends on the
3414 - 2.2.x kernels have the entry point at 0x0000000C,
3415 - 2.3.x and later kernels have the entry point at 0x00000000.
3417 So a typical call to build a U-Boot image would read:
3419 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
3420 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
3421 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux.gz \
3422 > examples/uImage.TQM850L
3423 Image Name: 2.4.4 kernel for TQM850L
3424 Created: Wed Jul 19 02:34:59 2000
3425 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3426 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
3427 Load Address: 0x00000000
3428 Entry Point: 0x00000000
3430 To verify the contents of the image (or check for corruption):
3432 -> tools/mkimage -l examples/uImage.TQM850L
3433 Image Name: 2.4.4 kernel for TQM850L
3434 Created: Wed Jul 19 02:34:59 2000
3435 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3436 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
3437 Load Address: 0x00000000
3438 Entry Point: 0x00000000
3440 NOTE: for embedded systems where boot time is critical you can trade
3441 speed for memory and install an UNCOMPRESSED image instead: this
3442 needs more space in Flash, but boots much faster since it does not
3443 need to be uncompressed:
3445 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux.gz
3446 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
3447 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
3448 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux \
3449 > examples/uImage.TQM850L-uncompressed
3450 Image Name: 2.4.4 kernel for TQM850L
3451 Created: Wed Jul 19 02:34:59 2000
3452 Image Type: PowerPC Linux Kernel Image (uncompressed)
3453 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
3454 Load Address: 0x00000000
3455 Entry Point: 0x00000000
3458 Similar you can build U-Boot images from a 'ramdisk.image.gz' file
3459 when your kernel is intended to use an initial ramdisk:
3461 -> tools/mkimage -n 'Simple Ramdisk Image' \
3462 > -A ppc -O linux -T ramdisk -C gzip \
3463 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
3464 Image Name: Simple Ramdisk Image
3465 Created: Wed Jan 12 14:01:50 2000
3466 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
3467 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
3468 Load Address: 0x00000000
3469 Entry Point: 0x00000000
3472 Installing a Linux Image:
3473 -------------------------
3475 To downloading a U-Boot image over the serial (console) interface,
3476 you must convert the image to S-Record format:
3478 objcopy -I binary -O srec examples/image examples/image.srec
3480 The 'objcopy' does not understand the information in the U-Boot
3481 image header, so the resulting S-Record file will be relative to
3482 address 0x00000000. To load it to a given address, you need to
3483 specify the target address as 'offset' parameter with the 'loads'
3486 Example: install the image to address 0x40100000 (which on the
3487 TQM8xxL is in the first Flash bank):
3489 => erase 40100000 401FFFFF
3495 ## Ready for S-Record download ...
3496 ~>examples/image.srec
3497 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
3499 15989 15990 15991 15992
3500 [file transfer complete]
3502 ## Start Addr = 0x00000000
3505 You can check the success of the download using the 'iminfo' command;
3506 this includes a checksum verification so you can be sure no data
3507 corruption happened:
3511 ## Checking Image at 40100000 ...
3512 Image Name: 2.2.13 for initrd on TQM850L
3513 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3514 Data Size: 335725 Bytes = 327 kB = 0 MB
3515 Load Address: 00000000
3516 Entry Point: 0000000c
3517 Verifying Checksum ... OK
3523 The "bootm" command is used to boot an application that is stored in
3524 memory (RAM or Flash). In case of a Linux kernel image, the contents
3525 of the "bootargs" environment variable is passed to the kernel as
3526 parameters. You can check and modify this variable using the
3527 "printenv" and "setenv" commands:
3530 => printenv bootargs
3531 bootargs=root=/dev/ram
3533 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
3535 => printenv bootargs
3536 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
3539 ## Booting Linux kernel at 40020000 ...
3540 Image Name: 2.2.13 for NFS on TQM850L
3541 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3542 Data Size: 381681 Bytes = 372 kB = 0 MB
3543 Load Address: 00000000
3544 Entry Point: 0000000c
3545 Verifying Checksum ... OK
3546 Uncompressing Kernel Image ... OK
3547 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
3548 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
3549 time_init: decrementer frequency = 187500000/60
3550 Calibrating delay loop... 49.77 BogoMIPS
3551 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
3554 If you want to boot a Linux kernel with initial RAM disk, you pass
3555 the memory addresses of both the kernel and the initrd image (PPBCOOT
3556 format!) to the "bootm" command:
3558 => imi 40100000 40200000
3560 ## Checking Image at 40100000 ...
3561 Image Name: 2.2.13 for initrd on TQM850L
3562 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3563 Data Size: 335725 Bytes = 327 kB = 0 MB
3564 Load Address: 00000000
3565 Entry Point: 0000000c
3566 Verifying Checksum ... OK
3568 ## Checking Image at 40200000 ...
3569 Image Name: Simple Ramdisk Image
3570 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
3571 Data Size: 566530 Bytes = 553 kB = 0 MB
3572 Load Address: 00000000
3573 Entry Point: 00000000
3574 Verifying Checksum ... OK
3576 => bootm 40100000 40200000
3577 ## Booting Linux kernel at 40100000 ...
3578 Image Name: 2.2.13 for initrd on TQM850L
3579 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3580 Data Size: 335725 Bytes = 327 kB = 0 MB
3581 Load Address: 00000000
3582 Entry Point: 0000000c
3583 Verifying Checksum ... OK
3584 Uncompressing Kernel Image ... OK
3585 ## Loading RAMDisk Image at 40200000 ...
3586 Image Name: Simple Ramdisk Image
3587 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
3588 Data Size: 566530 Bytes = 553 kB = 0 MB
3589 Load Address: 00000000
3590 Entry Point: 00000000
3591 Verifying Checksum ... OK
3592 Loading Ramdisk ... OK
3593 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
3594 Boot arguments: root=/dev/ram
3595 time_init: decrementer frequency = 187500000/60
3596 Calibrating delay loop... 49.77 BogoMIPS
3598 RAMDISK: Compressed image found at block 0
3599 VFS: Mounted root (ext2 filesystem).
3603 Boot Linux and pass a flat device tree:
3606 First, U-Boot must be compiled with the appropriate defines. See the section
3607 titled "Linux Kernel Interface" above for a more in depth explanation. The
3608 following is an example of how to start a kernel and pass an updated
3614 oft=oftrees/mpc8540ads.dtb
3615 => tftp $oftaddr $oft
3616 Speed: 1000, full duplex
3618 TFTP from server 192.168.1.1; our IP address is 192.168.1.101
3619 Filename 'oftrees/mpc8540ads.dtb'.
3620 Load address: 0x300000
3623 Bytes transferred = 4106 (100a hex)
3624 => tftp $loadaddr $bootfile
3625 Speed: 1000, full duplex
3627 TFTP from server 192.168.1.1; our IP address is 192.168.1.2
3629 Load address: 0x200000
3630 Loading:############
3632 Bytes transferred = 1029407 (fb51f hex)
3637 => bootm $loadaddr - $oftaddr
3638 ## Booting image at 00200000 ...
3639 Image Name: Linux-2.6.17-dirty
3640 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3641 Data Size: 1029343 Bytes = 1005.2 kB
3642 Load Address: 00000000
3643 Entry Point: 00000000
3644 Verifying Checksum ... OK
3645 Uncompressing Kernel Image ... OK
3646 Booting using flat device tree at 0x300000
3647 Using MPC85xx ADS machine description
3648 Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb
3652 More About U-Boot Image Types:
3653 ------------------------------
3655 U-Boot supports the following image types:
3657 "Standalone Programs" are directly runnable in the environment
3658 provided by U-Boot; it is expected that (if they behave
3659 well) you can continue to work in U-Boot after return from
3660 the Standalone Program.
3661 "OS Kernel Images" are usually images of some Embedded OS which
3662 will take over control completely. Usually these programs
3663 will install their own set of exception handlers, device
3664 drivers, set up the MMU, etc. - this means, that you cannot
3665 expect to re-enter U-Boot except by resetting the CPU.
3666 "RAMDisk Images" are more or less just data blocks, and their
3667 parameters (address, size) are passed to an OS kernel that is
3669 "Multi-File Images" contain several images, typically an OS
3670 (Linux) kernel image and one or more data images like
3671 RAMDisks. This construct is useful for instance when you want
3672 to boot over the network using BOOTP etc., where the boot
3673 server provides just a single image file, but you want to get
3674 for instance an OS kernel and a RAMDisk image.
3676 "Multi-File Images" start with a list of image sizes, each
3677 image size (in bytes) specified by an "uint32_t" in network
3678 byte order. This list is terminated by an "(uint32_t)0".
3679 Immediately after the terminating 0 follow the images, one by
3680 one, all aligned on "uint32_t" boundaries (size rounded up to
3681 a multiple of 4 bytes).
3683 "Firmware Images" are binary images containing firmware (like
3684 U-Boot or FPGA images) which usually will be programmed to
3687 "Script files" are command sequences that will be executed by
3688 U-Boot's command interpreter; this feature is especially
3689 useful when you configure U-Boot to use a real shell (hush)
3690 as command interpreter.
3696 One of the features of U-Boot is that you can dynamically load and
3697 run "standalone" applications, which can use some resources of
3698 U-Boot like console I/O functions or interrupt services.
3700 Two simple examples are included with the sources:
3705 'examples/hello_world.c' contains a small "Hello World" Demo
3706 application; it is automatically compiled when you build U-Boot.
3707 It's configured to run at address 0x00040004, so you can play with it
3711 ## Ready for S-Record download ...
3712 ~>examples/hello_world.srec
3713 1 2 3 4 5 6 7 8 9 10 11 ...
3714 [file transfer complete]
3716 ## Start Addr = 0x00040004
3718 => go 40004 Hello World! This is a test.
3719 ## Starting application at 0x00040004 ...
3730 Hit any key to exit ...
3732 ## Application terminated, rc = 0x0
3734 Another example, which demonstrates how to register a CPM interrupt
3735 handler with the U-Boot code, can be found in 'examples/timer.c'.
3736 Here, a CPM timer is set up to generate an interrupt every second.
3737 The interrupt service routine is trivial, just printing a '.'
3738 character, but this is just a demo program. The application can be
3739 controlled by the following keys:
3741 ? - print current values og the CPM Timer registers
3742 b - enable interrupts and start timer
3743 e - stop timer and disable interrupts
3744 q - quit application
3747 ## Ready for S-Record download ...
3748 ~>examples/timer.srec
3749 1 2 3 4 5 6 7 8 9 10 11 ...
3750 [file transfer complete]
3752 ## Start Addr = 0x00040004
3755 ## Starting application at 0x00040004 ...
3758 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
3761 [q, b, e, ?] Set interval 1000000 us
3764 [q, b, e, ?] ........
3765 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
3768 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
3771 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
3774 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
3776 [q, b, e, ?] ...Stopping timer
3778 [q, b, e, ?] ## Application terminated, rc = 0x0
3784 Over time, many people have reported problems when trying to use the
3785 "minicom" terminal emulation program for serial download. I (wd)
3786 consider minicom to be broken, and recommend not to use it. Under
3787 Unix, I recommend to use C-Kermit for general purpose use (and
3788 especially for kermit binary protocol download ("loadb" command), and
3789 use "cu" for S-Record download ("loads" command).
3791 Nevertheless, if you absolutely want to use it try adding this
3792 configuration to your "File transfer protocols" section:
3794 Name Program Name U/D FullScr IO-Red. Multi
3795 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
3796 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
3802 Starting at version 0.9.2, U-Boot supports NetBSD both as host
3803 (build U-Boot) and target system (boots NetBSD/mpc8xx).
3805 Building requires a cross environment; it is known to work on
3806 NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
3807 need gmake since the Makefiles are not compatible with BSD make).
3808 Note that the cross-powerpc package does not install include files;
3809 attempting to build U-Boot will fail because <machine/ansi.h> is
3810 missing. This file has to be installed and patched manually:
3812 # cd /usr/pkg/cross/powerpc-netbsd/include
3814 # ln -s powerpc machine
3815 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
3816 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
3818 Native builds *don't* work due to incompatibilities between native
3819 and U-Boot include files.
3821 Booting assumes that (the first part of) the image booted is a
3822 stage-2 loader which in turn loads and then invokes the kernel
3823 proper. Loader sources will eventually appear in the NetBSD source
3824 tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
3825 meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz
3828 Implementation Internals:
3829 =========================
3831 The following is not intended to be a complete description of every
3832 implementation detail. However, it should help to understand the
3833 inner workings of U-Boot and make it easier to port it to custom
3837 Initial Stack, Global Data:
3838 ---------------------------
3840 The implementation of U-Boot is complicated by the fact that U-Boot
3841 starts running out of ROM (flash memory), usually without access to
3842 system RAM (because the memory controller is not initialized yet).
3843 This means that we don't have writable Data or BSS segments, and BSS
3844 is not initialized as zero. To be able to get a C environment working
3845 at all, we have to allocate at least a minimal stack. Implementation
3846 options for this are defined and restricted by the CPU used: Some CPU
3847 models provide on-chip memory (like the IMMR area on MPC8xx and
3848 MPC826x processors), on others (parts of) the data cache can be
3849 locked as (mis-) used as memory, etc.
3851 Chris Hallinan posted a good summary of these issues to the
3852 U-Boot mailing list:
3854 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
3855 From: "Chris Hallinan" <clh@net1plus.com>
3856 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
3859 Correct me if I'm wrong, folks, but the way I understand it
3860 is this: Using DCACHE as initial RAM for Stack, etc, does not
3861 require any physical RAM backing up the cache. The cleverness
3862 is that the cache is being used as a temporary supply of
3863 necessary storage before the SDRAM controller is setup. It's
3864 beyond the scope of this list to explain the details, but you
3865 can see how this works by studying the cache architecture and
3866 operation in the architecture and processor-specific manuals.
3868 OCM is On Chip Memory, which I believe the 405GP has 4K. It
3869 is another option for the system designer to use as an
3870 initial stack/RAM area prior to SDRAM being available. Either
3871 option should work for you. Using CS 4 should be fine if your
3872 board designers haven't used it for something that would
3873 cause you grief during the initial boot! It is frequently not
3876 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere
3877 with your processor/board/system design. The default value
3878 you will find in any recent u-boot distribution in
3879 walnut.h should work for you. I'd set it to a value larger
3880 than your SDRAM module. If you have a 64MB SDRAM module, set
3881 it above 400_0000. Just make sure your board has no resources
3882 that are supposed to respond to that address! That code in
3883 start.S has been around a while and should work as is when
3884 you get the config right.
3889 It is essential to remember this, since it has some impact on the C
3890 code for the initialization procedures:
3892 * Initialized global data (data segment) is read-only. Do not attempt
3895 * Do not use any uninitialized global data (or implicitely initialized
3896 as zero data - BSS segment) at all - this is undefined, initiali-
3897 zation is performed later (when relocating to RAM).
3899 * Stack space is very limited. Avoid big data buffers or things like
3902 Having only the stack as writable memory limits means we cannot use
3903 normal global data to share information beween the code. But it
3904 turned out that the implementation of U-Boot can be greatly
3905 simplified by making a global data structure (gd_t) available to all
3906 functions. We could pass a pointer to this data as argument to _all_
3907 functions, but this would bloat the code. Instead we use a feature of
3908 the GCC compiler (Global Register Variables) to share the data: we
3909 place a pointer (gd) to the global data into a register which we
3910 reserve for this purpose.
3912 When choosing a register for such a purpose we are restricted by the
3913 relevant (E)ABI specifications for the current architecture, and by
3914 GCC's implementation.
3916 For PowerPC, the following registers have specific use:
3918 R2: reserved for system use
3919 R3-R4: parameter passing and return values
3920 R5-R10: parameter passing
3921 R13: small data area pointer
3925 (U-Boot also uses R12 as internal GOT pointer. r12
3926 is a volatile register so r12 needs to be reset when
3927 going back and forth between asm and C)
3929 ==> U-Boot will use R2 to hold a pointer to the global data
3931 Note: on PPC, we could use a static initializer (since the
3932 address of the global data structure is known at compile time),
3933 but it turned out that reserving a register results in somewhat
3934 smaller code - although the code savings are not that big (on
3935 average for all boards 752 bytes for the whole U-Boot image,
3936 624 text + 127 data).
3938 On Blackfin, the normal C ABI (except for P3) is followed as documented here:
3939 http://docs.blackfin.uclinux.org/doku.php?id=application_binary_interface
3941 ==> U-Boot will use P3 to hold a pointer to the global data
3943 On ARM, the following registers are used:
3945 R0: function argument word/integer result
3946 R1-R3: function argument word
3948 R10: stack limit (used only if stack checking if enabled)
3949 R11: argument (frame) pointer
3950 R12: temporary workspace
3953 R15: program counter
3955 ==> U-Boot will use R8 to hold a pointer to the global data
3957 NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope,
3958 or current versions of GCC may "optimize" the code too much.
3963 U-Boot runs in system state and uses physical addresses, i.e. the
3964 MMU is not used either for address mapping nor for memory protection.
3966 The available memory is mapped to fixed addresses using the memory
3967 controller. In this process, a contiguous block is formed for each
3968 memory type (Flash, SDRAM, SRAM), even when it consists of several
3969 physical memory banks.
3971 U-Boot is installed in the first 128 kB of the first Flash bank (on
3972 TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
3973 booting and sizing and initializing DRAM, the code relocates itself
3974 to the upper end of DRAM. Immediately below the U-Boot code some
3975 memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN
3976 configuration setting]. Below that, a structure with global Board
3977 Info data is placed, followed by the stack (growing downward).
3979 Additionally, some exception handler code is copied to the low 8 kB
3980 of DRAM (0x00000000 ... 0x00001FFF).
3982 So a typical memory configuration with 16 MB of DRAM could look like
3985 0x0000 0000 Exception Vector code
3988 0x0000 2000 Free for Application Use
3994 0x00FB FF20 Monitor Stack (Growing downward)
3995 0x00FB FFAC Board Info Data and permanent copy of global data
3996 0x00FC 0000 Malloc Arena
3999 0x00FE 0000 RAM Copy of Monitor Code
4000 ... eventually: LCD or video framebuffer
4001 ... eventually: pRAM (Protected RAM - unchanged by reset)
4002 0x00FF FFFF [End of RAM]
4005 System Initialization:
4006 ----------------------
4008 In the reset configuration, U-Boot starts at the reset entry point
4009 (on most PowerPC systems at address 0x00000100). Because of the reset
4010 configuration for CS0# this is a mirror of the onboard Flash memory.
4011 To be able to re-map memory U-Boot then jumps to its link address.
4012 To be able to implement the initialization code in C, a (small!)
4013 initial stack is set up in the internal Dual Ported RAM (in case CPUs
4014 which provide such a feature like MPC8xx or MPC8260), or in a locked
4015 part of the data cache. After that, U-Boot initializes the CPU core,
4016 the caches and the SIU.
4018 Next, all (potentially) available memory banks are mapped using a
4019 preliminary mapping. For example, we put them on 512 MB boundaries
4020 (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
4021 on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
4022 programmed for SDRAM access. Using the temporary configuration, a
4023 simple memory test is run that determines the size of the SDRAM
4026 When there is more than one SDRAM bank, and the banks are of
4027 different size, the largest is mapped first. For equal size, the first
4028 bank (CS2#) is mapped first. The first mapping is always for address
4029 0x00000000, with any additional banks following immediately to create
4030 contiguous memory starting from 0.
4032 Then, the monitor installs itself at the upper end of the SDRAM area
4033 and allocates memory for use by malloc() and for the global Board
4034 Info data; also, the exception vector code is copied to the low RAM
4035 pages, and the final stack is set up.
4037 Only after this relocation will you have a "normal" C environment;
4038 until that you are restricted in several ways, mostly because you are
4039 running from ROM, and because the code will have to be relocated to a
4043 U-Boot Porting Guide:
4044 ----------------------
4046 [Based on messages by Jerry Van Baren in the U-Boot-Users mailing
4050 int main(int argc, char *argv[])
4052 sighandler_t no_more_time;
4054 signal(SIGALRM, no_more_time);
4055 alarm(PROJECT_DEADLINE - toSec (3 * WEEK));
4057 if (available_money > available_manpower) {
4058 Pay consultant to port U-Boot;
4062 Download latest U-Boot source;
4064 Subscribe to u-boot mailing list;
4067 email("Hi, I am new to U-Boot, how do I get started?");
4070 Read the README file in the top level directory;
4071 Read http://www.denx.de/twiki/bin/view/DULG/Manual;
4072 Read applicable doc/*.README;
4073 Read the source, Luke;
4074 /* find . -name "*.[chS]" | xargs grep -i <keyword> */
4077 if (available_money > toLocalCurrency ($2500))
4080 Add a lot of aggravation and time;
4082 if (a similar board exists) { /* hopefully... */
4083 cp -a board/<similar> board/<myboard>
4084 cp include/configs/<similar>.h include/configs/<myboard>.h
4086 Create your own board support subdirectory;
4087 Create your own board include/configs/<myboard>.h file;
4089 Edit new board/<myboard> files
4090 Edit new include/configs/<myboard>.h
4095 Add / modify source code;
4099 email("Hi, I am having problems...");
4101 Send patch file to the U-Boot email list;
4102 if (reasonable critiques)
4103 Incorporate improvements from email list code review;
4105 Defend code as written;
4111 void no_more_time (int sig)
4120 All contributions to U-Boot should conform to the Linux kernel
4121 coding style; see the file "Documentation/CodingStyle" and the script
4122 "scripts/Lindent" in your Linux kernel source directory. In sources
4123 originating from U-Boot a style corresponding to "Lindent -pcs" (adding
4124 spaces before parameters to function calls) is actually used.
4126 Source files originating from a different project (for example the
4127 MTD subsystem) are generally exempt from these guidelines and are not
4128 reformated to ease subsequent migration to newer versions of those
4131 Please note that U-Boot is implemented in C (and to some small parts in
4132 Assembler); no C++ is used, so please do not use C++ style comments (//)
4135 Please also stick to the following formatting rules:
4136 - remove any trailing white space
4137 - use TAB characters for indentation, not spaces
4138 - make sure NOT to use DOS '\r\n' line feeds
4139 - do not add more than 2 empty lines to source files
4140 - do not add trailing empty lines to source files
4142 Submissions which do not conform to the standards may be returned
4143 with a request to reformat the changes.
4149 Since the number of patches for U-Boot is growing, we need to
4150 establish some rules. Submissions which do not conform to these rules
4151 may be rejected, even when they contain important and valuable stuff.
4153 Please see http://www.denx.de/wiki/U-Boot/Patches for details.
4155 Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>;
4156 see http://lists.denx.de/mailman/listinfo/u-boot
4158 When you send a patch, please include the following information with
4161 * For bug fixes: a description of the bug and how your patch fixes
4162 this bug. Please try to include a way of demonstrating that the
4163 patch actually fixes something.
4165 * For new features: a description of the feature and your
4168 * A CHANGELOG entry as plaintext (separate from the patch)
4170 * For major contributions, your entry to the CREDITS file
4172 * When you add support for a new board, don't forget to add this
4173 board to the MAKEALL script, too.
4175 * If your patch adds new configuration options, don't forget to
4176 document these in the README file.
4178 * The patch itself. If you are using git (which is *strongly*
4179 recommended) you can easily generate the patch using the
4180 "git-format-patch". If you then use "git-send-email" to send it to
4181 the U-Boot mailing list, you will avoid most of the common problems
4182 with some other mail clients.
4184 If you cannot use git, use "diff -purN OLD NEW". If your version of
4185 diff does not support these options, then get the latest version of
4188 The current directory when running this command shall be the parent
4189 directory of the U-Boot source tree (i. e. please make sure that
4190 your patch includes sufficient directory information for the
4193 We prefer patches as plain text. MIME attachments are discouraged,
4194 and compressed attachments must not be used.
4196 * If one logical set of modifications affects or creates several
4197 files, all these changes shall be submitted in a SINGLE patch file.
4199 * Changesets that contain different, unrelated modifications shall be
4200 submitted as SEPARATE patches, one patch per changeset.
4205 * Before sending the patch, run the MAKEALL script on your patched
4206 source tree and make sure that no errors or warnings are reported
4207 for any of the boards.
4209 * Keep your modifications to the necessary minimum: A patch
4210 containing several unrelated changes or arbitrary reformats will be
4211 returned with a request to re-formatting / split it.
4213 * If you modify existing code, make sure that your new code does not
4214 add to the memory footprint of the code ;-) Small is beautiful!
4215 When adding new features, these should compile conditionally only
4216 (using #ifdef), and the resulting code with the new feature
4217 disabled must not need more memory than the old code without your
4220 * Remember that there is a size limit of 100 kB per message on the
4221 u-boot mailing list. Bigger patches will be moderated. If they are
4222 reasonable and not too big, they will be acknowledged. But patches
4223 bigger than the size limit should be avoided.
projects / people / ms / u-boot.git / blob