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_AT91EMAC
826 Support for AT91RM9200 EMAC.
829 Define this to use reduced MII inteface
831 CONFIG_DRIVER_AT91EMAC_QUIET
832 If this defined, the driver is quiet.
833 The driver doen't show link status messages.
835 CONFIG_DRIVER_LAN91C96
836 Support for SMSC's LAN91C96 chips.
839 Define this to hold the physical address
840 of the LAN91C96's I/O space
842 CONFIG_LAN91C96_USE_32_BIT
843 Define this to enable 32 bit addressing
845 CONFIG_DRIVER_SMC91111
846 Support for SMSC's LAN91C111 chip
849 Define this to hold the physical address
850 of the device (I/O space)
852 CONFIG_SMC_USE_32_BIT
853 Define this if data bus is 32 bits
855 CONFIG_SMC_USE_IOFUNCS
856 Define this to use i/o functions instead of macros
857 (some hardware wont work with macros)
860 Support for SMSC's LAN911x and LAN921x chips
863 Define this to hold the physical address
864 of the device (I/O space)
866 CONFIG_SMC911X_32_BIT
867 Define this if data bus is 32 bits
869 CONFIG_SMC911X_16_BIT
870 Define this if data bus is 16 bits. If your processor
871 automatically converts one 32 bit word to two 16 bit
872 words you may also try CONFIG_SMC911X_32_BIT.
875 At the moment only the UHCI host controller is
876 supported (PIP405, MIP405, MPC5200); define
877 CONFIG_USB_UHCI to enable it.
878 define CONFIG_USB_KEYBOARD to enable the USB Keyboard
879 and define CONFIG_USB_STORAGE to enable the USB
882 Supported are USB Keyboards and USB Floppy drives
884 MPC5200 USB requires additional defines:
886 for 528 MHz Clock: 0x0001bbbb
890 for differential drivers: 0x00001000
891 for single ended drivers: 0x00005000
892 for differential drivers on PSC3: 0x00000100
893 for single ended drivers on PSC3: 0x00004100
894 CONFIG_SYS_USB_EVENT_POLL
895 May be defined to allow interrupt polling
896 instead of using asynchronous interrupts
899 Define the below if you wish to use the USB console.
900 Once firmware is rebuilt from a serial console issue the
901 command "setenv stdin usbtty; setenv stdout usbtty" and
902 attach your USB cable. The Unix command "dmesg" should print
903 it has found a new device. The environment variable usbtty
904 can be set to gserial or cdc_acm to enable your device to
905 appear to a USB host as a Linux gserial device or a
906 Common Device Class Abstract Control Model serial device.
907 If you select usbtty = gserial you should be able to enumerate
909 # modprobe usbserial vendor=0xVendorID product=0xProductID
910 else if using cdc_acm, simply setting the environment
911 variable usbtty to be cdc_acm should suffice. The following
912 might be defined in YourBoardName.h
915 Define this to build a UDC device
918 Define this to have a tty type of device available to
919 talk to the UDC device
921 CONFIG_SYS_CONSOLE_IS_IN_ENV
922 Define this if you want stdin, stdout &/or stderr to
926 CONFIG_SYS_USB_EXTC_CLK 0xBLAH
927 Derive USB clock from external clock "blah"
928 - CONFIG_SYS_USB_EXTC_CLK 0x02
930 CONFIG_SYS_USB_BRG_CLK 0xBLAH
931 Derive USB clock from brgclk
932 - CONFIG_SYS_USB_BRG_CLK 0x04
934 If you have a USB-IF assigned VendorID then you may wish to
935 define your own vendor specific values either in BoardName.h
936 or directly in usbd_vendor_info.h. If you don't define
937 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME,
938 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot
939 should pretend to be a Linux device to it's target host.
941 CONFIG_USBD_MANUFACTURER
942 Define this string as the name of your company for
943 - CONFIG_USBD_MANUFACTURER "my company"
945 CONFIG_USBD_PRODUCT_NAME
946 Define this string as the name of your product
947 - CONFIG_USBD_PRODUCT_NAME "acme usb device"
950 Define this as your assigned Vendor ID from the USB
951 Implementors Forum. This *must* be a genuine Vendor ID
952 to avoid polluting the USB namespace.
953 - CONFIG_USBD_VENDORID 0xFFFF
955 CONFIG_USBD_PRODUCTID
956 Define this as the unique Product ID
958 - CONFIG_USBD_PRODUCTID 0xFFFF
962 The MMC controller on the Intel PXA is supported. To
963 enable this define CONFIG_MMC. The MMC can be
964 accessed from the boot prompt by mapping the device
965 to physical memory similar to flash. Command line is
966 enabled with CONFIG_CMD_MMC. The MMC driver also works with
967 the FAT fs. This is enabled with CONFIG_CMD_FAT.
969 - Journaling Flash filesystem support:
970 CONFIG_JFFS2_NAND, CONFIG_JFFS2_NAND_OFF, CONFIG_JFFS2_NAND_SIZE,
971 CONFIG_JFFS2_NAND_DEV
972 Define these for a default partition on a NAND device
974 CONFIG_SYS_JFFS2_FIRST_SECTOR,
975 CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS
976 Define these for a default partition on a NOR device
978 CONFIG_SYS_JFFS_CUSTOM_PART
979 Define this to create an own partition. You have to provide a
980 function struct part_info* jffs2_part_info(int part_num)
982 If you define only one JFFS2 partition you may also want to
983 #define CONFIG_SYS_JFFS_SINGLE_PART 1
984 to disable the command chpart. This is the default when you
985 have not defined a custom partition
990 Define this to enable standard (PC-Style) keyboard
994 Standard PC keyboard driver with US (is default) and
995 GERMAN key layout (switch via environment 'keymap=de') support.
996 Export function i8042_kbd_init, i8042_tstc and i8042_getc
997 for cfb_console. Supports cursor blinking.
1002 Define this to enable video support (for output to
1005 CONFIG_VIDEO_CT69000
1007 Enable Chips & Technologies 69000 Video chip
1009 CONFIG_VIDEO_SMI_LYNXEM
1010 Enable Silicon Motion SMI 712/710/810 Video chip. The
1011 video output is selected via environment 'videoout'
1012 (1 = LCD and 2 = CRT). If videoout is undefined, CRT is
1015 For the CT69000 and SMI_LYNXEM drivers, videomode is
1016 selected via environment 'videomode'. Two different ways
1018 - "videomode=num" 'num' is a standard LiLo mode numbers.
1019 Following standard modes are supported (* is default):
1021 Colors 640x480 800x600 1024x768 1152x864 1280x1024
1022 -------------+---------------------------------------------
1023 8 bits | 0x301* 0x303 0x305 0x161 0x307
1024 15 bits | 0x310 0x313 0x316 0x162 0x319
1025 16 bits | 0x311 0x314 0x317 0x163 0x31A
1026 24 bits | 0x312 0x315 0x318 ? 0x31B
1027 -------------+---------------------------------------------
1028 (i.e. setenv videomode 317; saveenv; reset;)
1030 - "videomode=bootargs" all the video parameters are parsed
1031 from the bootargs. (See drivers/video/videomodes.c)
1034 CONFIG_VIDEO_SED13806
1035 Enable Epson SED13806 driver. This driver supports 8bpp
1036 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP
1037 or CONFIG_VIDEO_SED13806_16BPP
1042 Define this to enable a custom keyboard support.
1043 This simply calls drv_keyboard_init() which must be
1044 defined in your board-specific files.
1045 The only board using this so far is RBC823.
1047 - LCD Support: CONFIG_LCD
1049 Define this to enable LCD support (for output to LCD
1050 display); also select one of the supported displays
1051 by defining one of these:
1055 HITACHI TX09D70VM1CCA, 3.5", 240x320.
1057 CONFIG_NEC_NL6448AC33:
1059 NEC NL6448AC33-18. Active, color, single scan.
1061 CONFIG_NEC_NL6448BC20
1063 NEC NL6448BC20-08. 6.5", 640x480.
1064 Active, color, single scan.
1066 CONFIG_NEC_NL6448BC33_54
1068 NEC NL6448BC33-54. 10.4", 640x480.
1069 Active, color, single scan.
1073 Sharp 320x240. Active, color, single scan.
1074 It isn't 16x9, and I am not sure what it is.
1076 CONFIG_SHARP_LQ64D341
1078 Sharp LQ64D341 display, 640x480.
1079 Active, color, single scan.
1083 HLD1045 display, 640x480.
1084 Active, color, single scan.
1088 Optrex CBL50840-2 NF-FW 99 22 M5
1090 Hitachi LMG6912RPFC-00T
1094 320x240. Black & white.
1096 Normally display is black on white background; define
1097 CONFIG_SYS_WHITE_ON_BLACK to get it inverted.
1099 - Splash Screen Support: CONFIG_SPLASH_SCREEN
1101 If this option is set, the environment is checked for
1102 a variable "splashimage". If found, the usual display
1103 of logo, copyright and system information on the LCD
1104 is suppressed and the BMP image at the address
1105 specified in "splashimage" is loaded instead. The
1106 console is redirected to the "nulldev", too. This
1107 allows for a "silent" boot where a splash screen is
1108 loaded very quickly after power-on.
1110 CONFIG_SPLASH_SCREEN_ALIGN
1112 If this option is set the splash image can be freely positioned
1113 on the screen. Environment variable "splashpos" specifies the
1114 position as "x,y". If a positive number is given it is used as
1115 number of pixel from left/top. If a negative number is given it
1116 is used as number of pixel from right/bottom. You can also
1117 specify 'm' for centering the image.
1120 setenv splashpos m,m
1121 => image at center of screen
1123 setenv splashpos 30,20
1124 => image at x = 30 and y = 20
1126 setenv splashpos -10,m
1127 => vertically centered image
1128 at x = dspWidth - bmpWidth - 9
1130 - Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP
1132 If this option is set, additionally to standard BMP
1133 images, gzipped BMP images can be displayed via the
1134 splashscreen support or the bmp command.
1136 - Compression support:
1139 If this option is set, support for bzip2 compressed
1140 images is included. If not, only uncompressed and gzip
1141 compressed images are supported.
1143 NOTE: the bzip2 algorithm requires a lot of RAM, so
1144 the malloc area (as defined by CONFIG_SYS_MALLOC_LEN) should
1149 If this option is set, support for lzma compressed
1152 Note: The LZMA algorithm adds between 2 and 4KB of code and it
1153 requires an amount of dynamic memory that is given by the
1156 (1846 + 768 << (lc + lp)) * sizeof(uint16)
1158 Where lc and lp stand for, respectively, Literal context bits
1159 and Literal pos bits.
1161 This value is upper-bounded by 14MB in the worst case. Anyway,
1162 for a ~4MB large kernel image, we have lc=3 and lp=0 for a
1163 total amount of (1846 + 768 << (3 + 0)) * 2 = ~41KB... that is
1164 a very small buffer.
1166 Use the lzmainfo tool to determinate the lc and lp values and
1167 then calculate the amount of needed dynamic memory (ensuring
1168 the appropriate CONFIG_SYS_MALLOC_LEN value).
1173 The address of PHY on MII bus.
1175 CONFIG_PHY_CLOCK_FREQ (ppc4xx)
1177 The clock frequency of the MII bus
1181 If this option is set, support for speed/duplex
1182 detection of gigabit PHY is included.
1184 CONFIG_PHY_RESET_DELAY
1186 Some PHY like Intel LXT971A need extra delay after
1187 reset before any MII register access is possible.
1188 For such PHY, set this option to the usec delay
1189 required. (minimum 300usec for LXT971A)
1191 CONFIG_PHY_CMD_DELAY (ppc4xx)
1193 Some PHY like Intel LXT971A need extra delay after
1194 command issued before MII status register can be read
1204 Define a default value for Ethernet address to use
1205 for the respective Ethernet interface, in case this
1206 is not determined automatically.
1211 Define a default value for the IP address to use for
1212 the default Ethernet interface, in case this is not
1213 determined through e.g. bootp.
1215 - Server IP address:
1218 Defines a default value for the IP address of a TFTP
1219 server to contact when using the "tftboot" command.
1221 CONFIG_KEEP_SERVERADDR
1223 Keeps the server's MAC address, in the env 'serveraddr'
1224 for passing to bootargs (like Linux's netconsole option)
1226 - Multicast TFTP Mode:
1229 Defines whether you want to support multicast TFTP as per
1230 rfc-2090; for example to work with atftp. Lets lots of targets
1231 tftp down the same boot image concurrently. Note: the Ethernet
1232 driver in use must provide a function: mcast() to join/leave a
1235 CONFIG_BOOTP_RANDOM_DELAY
1236 - BOOTP Recovery Mode:
1237 CONFIG_BOOTP_RANDOM_DELAY
1239 If you have many targets in a network that try to
1240 boot using BOOTP, you may want to avoid that all
1241 systems send out BOOTP requests at precisely the same
1242 moment (which would happen for instance at recovery
1243 from a power failure, when all systems will try to
1244 boot, thus flooding the BOOTP server. Defining
1245 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
1246 inserted before sending out BOOTP requests. The
1247 following delays are inserted then:
1249 1st BOOTP request: delay 0 ... 1 sec
1250 2nd BOOTP request: delay 0 ... 2 sec
1251 3rd BOOTP request: delay 0 ... 4 sec
1253 BOOTP requests: delay 0 ... 8 sec
1255 - DHCP Advanced Options:
1256 You can fine tune the DHCP functionality by defining
1257 CONFIG_BOOTP_* symbols:
1259 CONFIG_BOOTP_SUBNETMASK
1260 CONFIG_BOOTP_GATEWAY
1261 CONFIG_BOOTP_HOSTNAME
1262 CONFIG_BOOTP_NISDOMAIN
1263 CONFIG_BOOTP_BOOTPATH
1264 CONFIG_BOOTP_BOOTFILESIZE
1267 CONFIG_BOOTP_SEND_HOSTNAME
1268 CONFIG_BOOTP_NTPSERVER
1269 CONFIG_BOOTP_TIMEOFFSET
1270 CONFIG_BOOTP_VENDOREX
1272 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip
1273 environment variable, not the BOOTP server.
1275 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS
1276 serverip from a DHCP server, it is possible that more
1277 than one DNS serverip is offered to the client.
1278 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS
1279 serverip will be stored in the additional environment
1280 variable "dnsip2". The first DNS serverip is always
1281 stored in the variable "dnsip", when CONFIG_BOOTP_DNS
1284 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable
1285 to do a dynamic update of a DNS server. To do this, they
1286 need the hostname of the DHCP requester.
1287 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content
1288 of the "hostname" environment variable is passed as
1289 option 12 to the DHCP server.
1291 CONFIG_BOOTP_DHCP_REQUEST_DELAY
1293 A 32bit value in microseconds for a delay between
1294 receiving a "DHCP Offer" and sending the "DHCP Request".
1295 This fixes a problem with certain DHCP servers that don't
1296 respond 100% of the time to a "DHCP request". E.g. On an
1297 AT91RM9200 processor running at 180MHz, this delay needed
1298 to be *at least* 15,000 usec before a Windows Server 2003
1299 DHCP server would reply 100% of the time. I recommend at
1300 least 50,000 usec to be safe. The alternative is to hope
1301 that one of the retries will be successful but note that
1302 the DHCP timeout and retry process takes a longer than
1306 CONFIG_CDP_DEVICE_ID
1308 The device id used in CDP trigger frames.
1310 CONFIG_CDP_DEVICE_ID_PREFIX
1312 A two character string which is prefixed to the MAC address
1317 A printf format string which contains the ascii name of
1318 the port. Normally is set to "eth%d" which sets
1319 eth0 for the first Ethernet, eth1 for the second etc.
1321 CONFIG_CDP_CAPABILITIES
1323 A 32bit integer which indicates the device capabilities;
1324 0x00000010 for a normal host which does not forwards.
1328 An ascii string containing the version of the software.
1332 An ascii string containing the name of the platform.
1336 A 32bit integer sent on the trigger.
1338 CONFIG_CDP_POWER_CONSUMPTION
1340 A 16bit integer containing the power consumption of the
1341 device in .1 of milliwatts.
1343 CONFIG_CDP_APPLIANCE_VLAN_TYPE
1345 A byte containing the id of the VLAN.
1347 - Status LED: CONFIG_STATUS_LED
1349 Several configurations allow to display the current
1350 status using a LED. For instance, the LED will blink
1351 fast while running U-Boot code, stop blinking as
1352 soon as a reply to a BOOTP request was received, and
1353 start blinking slow once the Linux kernel is running
1354 (supported by a status LED driver in the Linux
1355 kernel). Defining CONFIG_STATUS_LED enables this
1358 - CAN Support: CONFIG_CAN_DRIVER
1360 Defining CONFIG_CAN_DRIVER enables CAN driver support
1361 on those systems that support this (optional)
1362 feature, like the TQM8xxL modules.
1364 - I2C Support: CONFIG_HARD_I2C | CONFIG_SOFT_I2C
1366 These enable I2C serial bus commands. Defining either of
1367 (but not both of) CONFIG_HARD_I2C or CONFIG_SOFT_I2C will
1368 include the appropriate I2C driver for the selected CPU.
1370 This will allow you to use i2c commands at the u-boot
1371 command line (as long as you set CONFIG_CMD_I2C in
1372 CONFIG_COMMANDS) and communicate with i2c based realtime
1373 clock chips. See common/cmd_i2c.c for a description of the
1374 command line interface.
1376 CONFIG_HARD_I2C selects a hardware I2C controller.
1378 CONFIG_SOFT_I2C configures u-boot to use a software (aka
1379 bit-banging) driver instead of CPM or similar hardware
1382 There are several other quantities that must also be
1383 defined when you define CONFIG_HARD_I2C or CONFIG_SOFT_I2C.
1385 In both cases you will need to define CONFIG_SYS_I2C_SPEED
1386 to be the frequency (in Hz) at which you wish your i2c bus
1387 to run and CONFIG_SYS_I2C_SLAVE to be the address of this node (ie
1388 the CPU's i2c node address).
1390 Now, the u-boot i2c code for the mpc8xx (cpu/mpc8xx/i2c.c)
1391 sets the CPU up as a master node and so its address should
1392 therefore be cleared to 0 (See, eg, MPC823e User's Manual
1393 p.16-473). So, set CONFIG_SYS_I2C_SLAVE to 0.
1395 CONFIG_SYS_I2C_INIT_MPC5XXX
1397 When a board is reset during an i2c bus transfer
1398 chips might think that the current transfer is still
1399 in progress. Reset the slave devices by sending start
1400 commands until the slave device responds.
1402 That's all that's required for CONFIG_HARD_I2C.
1404 If you use the software i2c interface (CONFIG_SOFT_I2C)
1405 then the following macros need to be defined (examples are
1406 from include/configs/lwmon.h):
1410 (Optional). Any commands necessary to enable the I2C
1411 controller or configure ports.
1413 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
1417 (Only for MPC8260 CPU). The I/O port to use (the code
1418 assumes both bits are on the same port). Valid values
1419 are 0..3 for ports A..D.
1423 The code necessary to make the I2C data line active
1424 (driven). If the data line is open collector, this
1427 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
1431 The code necessary to make the I2C data line tri-stated
1432 (inactive). If the data line is open collector, this
1435 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
1439 Code that returns TRUE if the I2C data line is high,
1442 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
1446 If <bit> is TRUE, sets the I2C data line high. If it
1447 is FALSE, it clears it (low).
1449 eg: #define I2C_SDA(bit) \
1450 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
1451 else immr->im_cpm.cp_pbdat &= ~PB_SDA
1455 If <bit> is TRUE, sets the I2C clock line high. If it
1456 is FALSE, it clears it (low).
1458 eg: #define I2C_SCL(bit) \
1459 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
1460 else immr->im_cpm.cp_pbdat &= ~PB_SCL
1464 This delay is invoked four times per clock cycle so this
1465 controls the rate of data transfer. The data rate thus
1466 is 1 / (I2C_DELAY * 4). Often defined to be something
1469 #define I2C_DELAY udelay(2)
1471 CONFIG_SYS_I2C_INIT_BOARD
1473 When a board is reset during an i2c bus transfer
1474 chips might think that the current transfer is still
1475 in progress. On some boards it is possible to access
1476 the i2c SCLK line directly, either by using the
1477 processor pin as a GPIO or by having a second pin
1478 connected to the bus. If this option is defined a
1479 custom i2c_init_board() routine in boards/xxx/board.c
1480 is run early in the boot sequence.
1482 CONFIG_I2CFAST (PPC405GP|PPC405EP only)
1484 This option enables configuration of bi_iic_fast[] flags
1485 in u-boot bd_info structure based on u-boot environment
1486 variable "i2cfast". (see also i2cfast)
1488 CONFIG_I2C_MULTI_BUS
1490 This option allows the use of multiple I2C buses, each of which
1491 must have a controller. At any point in time, only one bus is
1492 active. To switch to a different bus, use the 'i2c dev' command.
1493 Note that bus numbering is zero-based.
1495 CONFIG_SYS_I2C_NOPROBES
1497 This option specifies a list of I2C devices that will be skipped
1498 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS
1499 is set, specify a list of bus-device pairs. Otherwise, specify
1500 a 1D array of device addresses
1503 #undef CONFIG_I2C_MULTI_BUS
1504 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68}
1506 will skip addresses 0x50 and 0x68 on a board with one I2C bus
1508 #define CONFIG_I2C_MULTI_BUS
1509 #define CONFIG_SYS_I2C_MULTI_NOPROBES {{0,0x50},{0,0x68},{1,0x54}}
1511 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1
1513 CONFIG_SYS_SPD_BUS_NUM
1515 If defined, then this indicates the I2C bus number for DDR SPD.
1516 If not defined, then U-Boot assumes that SPD is on I2C bus 0.
1518 CONFIG_SYS_RTC_BUS_NUM
1520 If defined, then this indicates the I2C bus number for the RTC.
1521 If not defined, then U-Boot assumes that RTC is on I2C bus 0.
1523 CONFIG_SYS_DTT_BUS_NUM
1525 If defined, then this indicates the I2C bus number for the DTT.
1526 If not defined, then U-Boot assumes that DTT is on I2C bus 0.
1528 CONFIG_SYS_I2C_DTT_ADDR:
1530 If defined, specifies the I2C address of the DTT device.
1531 If not defined, then U-Boot uses predefined value for
1532 specified DTT device.
1536 Define this option if you want to use Freescale's I2C driver in
1537 drivers/i2c/fsl_i2c.c.
1541 Define this option if you have I2C devices reached over 1 .. n
1542 I2C Muxes like the pca9544a. This option addes a new I2C
1543 Command "i2c bus [muxtype:muxaddr:muxchannel]" which adds a
1544 new I2C Bus to the existing I2C Busses. If you select the
1545 new Bus with "i2c dev", u-bbot sends first the commandos for
1546 the muxes to activate this new "bus".
1548 CONFIG_I2C_MULTI_BUS must be also defined, to use this
1552 Adding a new I2C Bus reached over 2 pca9544a muxes
1553 The First mux with address 70 and channel 6
1554 The Second mux with address 71 and channel 4
1556 => i2c bus pca9544a:70:6:pca9544a:71:4
1558 Use the "i2c bus" command without parameter, to get a list
1559 of I2C Busses with muxes:
1562 Busses reached over muxes:
1564 reached over Mux(es):
1567 reached over Mux(es):
1572 If you now switch to the new I2C Bus 3 with "i2c dev 3"
1573 u-boot sends First the Commando to the mux@70 to enable
1574 channel 6, and then the Commando to the mux@71 to enable
1577 After that, you can use the "normal" i2c commands as
1578 usual, to communicate with your I2C devices behind
1581 This option is actually implemented for the bitbanging
1582 algorithm in common/soft_i2c.c and for the Hardware I2C
1583 Bus on the MPC8260. But it should be not so difficult
1584 to add this option to other architectures.
1586 CONFIG_SOFT_I2C_READ_REPEATED_START
1588 defining this will force the i2c_read() function in
1589 the soft_i2c driver to perform an I2C repeated start
1590 between writing the address pointer and reading the
1591 data. If this define is omitted the default behaviour
1592 of doing a stop-start sequence will be used. Most I2C
1593 devices can use either method, but some require one or
1596 - SPI Support: CONFIG_SPI
1598 Enables SPI driver (so far only tested with
1599 SPI EEPROM, also an instance works with Crystal A/D and
1600 D/As on the SACSng board)
1604 Enables extended (16-bit) SPI EEPROM addressing.
1605 (symmetrical to CONFIG_I2C_X)
1609 Enables a software (bit-bang) SPI driver rather than
1610 using hardware support. This is a general purpose
1611 driver that only requires three general I/O port pins
1612 (two outputs, one input) to function. If this is
1613 defined, the board configuration must define several
1614 SPI configuration items (port pins to use, etc). For
1615 an example, see include/configs/sacsng.h.
1619 Enables a hardware SPI driver for general-purpose reads
1620 and writes. As with CONFIG_SOFT_SPI, the board configuration
1621 must define a list of chip-select function pointers.
1622 Currently supported on some MPC8xxx processors. For an
1623 example, see include/configs/mpc8349emds.h.
1627 Enables the driver for the SPI controllers on i.MX and MXC
1628 SoCs. Currently only i.MX31 is supported.
1630 - FPGA Support: CONFIG_FPGA
1632 Enables FPGA subsystem.
1634 CONFIG_FPGA_<vendor>
1636 Enables support for specific chip vendors.
1639 CONFIG_FPGA_<family>
1641 Enables support for FPGA family.
1642 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX)
1646 Specify the number of FPGA devices to support.
1648 CONFIG_SYS_FPGA_PROG_FEEDBACK
1650 Enable printing of hash marks during FPGA configuration.
1652 CONFIG_SYS_FPGA_CHECK_BUSY
1654 Enable checks on FPGA configuration interface busy
1655 status by the configuration function. This option
1656 will require a board or device specific function to
1661 If defined, a function that provides delays in the FPGA
1662 configuration driver.
1664 CONFIG_SYS_FPGA_CHECK_CTRLC
1665 Allow Control-C to interrupt FPGA configuration
1667 CONFIG_SYS_FPGA_CHECK_ERROR
1669 Check for configuration errors during FPGA bitfile
1670 loading. For example, abort during Virtex II
1671 configuration if the INIT_B line goes low (which
1672 indicated a CRC error).
1674 CONFIG_SYS_FPGA_WAIT_INIT
1676 Maximum time to wait for the INIT_B line to deassert
1677 after PROB_B has been deasserted during a Virtex II
1678 FPGA configuration sequence. The default time is 500
1681 CONFIG_SYS_FPGA_WAIT_BUSY
1683 Maximum time to wait for BUSY to deassert during
1684 Virtex II FPGA configuration. The default is 5 ms.
1686 CONFIG_SYS_FPGA_WAIT_CONFIG
1688 Time to wait after FPGA configuration. The default is
1691 - Configuration Management:
1694 If defined, this string will be added to the U-Boot
1695 version information (U_BOOT_VERSION)
1697 - Vendor Parameter Protection:
1699 U-Boot considers the values of the environment
1700 variables "serial#" (Board Serial Number) and
1701 "ethaddr" (Ethernet Address) to be parameters that
1702 are set once by the board vendor / manufacturer, and
1703 protects these variables from casual modification by
1704 the user. Once set, these variables are read-only,
1705 and write or delete attempts are rejected. You can
1706 change this behaviour:
1708 If CONFIG_ENV_OVERWRITE is #defined in your config
1709 file, the write protection for vendor parameters is
1710 completely disabled. Anybody can change or delete
1713 Alternatively, if you #define _both_ CONFIG_ETHADDR
1714 _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
1715 Ethernet address is installed in the environment,
1716 which can be changed exactly ONCE by the user. [The
1717 serial# is unaffected by this, i. e. it remains
1723 Define this variable to enable the reservation of
1724 "protected RAM", i. e. RAM which is not overwritten
1725 by U-Boot. Define CONFIG_PRAM to hold the number of
1726 kB you want to reserve for pRAM. You can overwrite
1727 this default value by defining an environment
1728 variable "pram" to the number of kB you want to
1729 reserve. Note that the board info structure will
1730 still show the full amount of RAM. If pRAM is
1731 reserved, a new environment variable "mem" will
1732 automatically be defined to hold the amount of
1733 remaining RAM in a form that can be passed as boot
1734 argument to Linux, for instance like that:
1736 setenv bootargs ... mem=\${mem}
1739 This way you can tell Linux not to use this memory,
1740 either, which results in a memory region that will
1741 not be affected by reboots.
1743 *WARNING* If your board configuration uses automatic
1744 detection of the RAM size, you must make sure that
1745 this memory test is non-destructive. So far, the
1746 following board configurations are known to be
1749 ETX094, IVMS8, IVML24, SPD8xx, TQM8xxL,
1750 HERMES, IP860, RPXlite, LWMON, LANTEC,
1751 PCU_E, FLAGADM, TQM8260
1756 Define this variable to stop the system in case of a
1757 fatal error, so that you have to reset it manually.
1758 This is probably NOT a good idea for an embedded
1759 system where you want the system to reboot
1760 automatically as fast as possible, but it may be
1761 useful during development since you can try to debug
1762 the conditions that lead to the situation.
1764 CONFIG_NET_RETRY_COUNT
1766 This variable defines the number of retries for
1767 network operations like ARP, RARP, TFTP, or BOOTP
1768 before giving up the operation. If not defined, a
1769 default value of 5 is used.
1773 Timeout waiting for an ARP reply in milliseconds.
1775 - Command Interpreter:
1776 CONFIG_AUTO_COMPLETE
1778 Enable auto completion of commands using TAB.
1780 Note that this feature has NOT been implemented yet
1781 for the "hush" shell.
1784 CONFIG_SYS_HUSH_PARSER
1786 Define this variable to enable the "hush" shell (from
1787 Busybox) as command line interpreter, thus enabling
1788 powerful command line syntax like
1789 if...then...else...fi conditionals or `&&' and '||'
1790 constructs ("shell scripts").
1792 If undefined, you get the old, much simpler behaviour
1793 with a somewhat smaller memory footprint.
1796 CONFIG_SYS_PROMPT_HUSH_PS2
1798 This defines the secondary prompt string, which is
1799 printed when the command interpreter needs more input
1800 to complete a command. Usually "> ".
1804 In the current implementation, the local variables
1805 space and global environment variables space are
1806 separated. Local variables are those you define by
1807 simply typing `name=value'. To access a local
1808 variable later on, you have write `$name' or
1809 `${name}'; to execute the contents of a variable
1810 directly type `$name' at the command prompt.
1812 Global environment variables are those you use
1813 setenv/printenv to work with. To run a command stored
1814 in such a variable, you need to use the run command,
1815 and you must not use the '$' sign to access them.
1817 To store commands and special characters in a
1818 variable, please use double quotation marks
1819 surrounding the whole text of the variable, instead
1820 of the backslashes before semicolons and special
1823 - Commandline Editing and History:
1824 CONFIG_CMDLINE_EDITING
1826 Enable editing and History functions for interactive
1827 commandline input operations
1829 - Default Environment:
1830 CONFIG_EXTRA_ENV_SETTINGS
1832 Define this to contain any number of null terminated
1833 strings (variable = value pairs) that will be part of
1834 the default environment compiled into the boot image.
1836 For example, place something like this in your
1837 board's config file:
1839 #define CONFIG_EXTRA_ENV_SETTINGS \
1843 Warning: This method is based on knowledge about the
1844 internal format how the environment is stored by the
1845 U-Boot code. This is NOT an official, exported
1846 interface! Although it is unlikely that this format
1847 will change soon, there is no guarantee either.
1848 You better know what you are doing here.
1850 Note: overly (ab)use of the default environment is
1851 discouraged. Make sure to check other ways to preset
1852 the environment like the "source" command or the
1855 - DataFlash Support:
1856 CONFIG_HAS_DATAFLASH
1858 Defining this option enables DataFlash features and
1859 allows to read/write in Dataflash via the standard
1862 - SystemACE Support:
1865 Adding this option adds support for Xilinx SystemACE
1866 chips attached via some sort of local bus. The address
1867 of the chip must also be defined in the
1868 CONFIG_SYS_SYSTEMACE_BASE macro. For example:
1870 #define CONFIG_SYSTEMACE
1871 #define CONFIG_SYS_SYSTEMACE_BASE 0xf0000000
1873 When SystemACE support is added, the "ace" device type
1874 becomes available to the fat commands, i.e. fatls.
1876 - TFTP Fixed UDP Port:
1879 If this is defined, the environment variable tftpsrcp
1880 is used to supply the TFTP UDP source port value.
1881 If tftpsrcp isn't defined, the normal pseudo-random port
1882 number generator is used.
1884 Also, the environment variable tftpdstp is used to supply
1885 the TFTP UDP destination port value. If tftpdstp isn't
1886 defined, the normal port 69 is used.
1888 The purpose for tftpsrcp is to allow a TFTP server to
1889 blindly start the TFTP transfer using the pre-configured
1890 target IP address and UDP port. This has the effect of
1891 "punching through" the (Windows XP) firewall, allowing
1892 the remainder of the TFTP transfer to proceed normally.
1893 A better solution is to properly configure the firewall,
1894 but sometimes that is not allowed.
1896 - Show boot progress:
1897 CONFIG_SHOW_BOOT_PROGRESS
1899 Defining this option allows to add some board-
1900 specific code (calling a user-provided function
1901 "show_boot_progress(int)") that enables you to show
1902 the system's boot progress on some display (for
1903 example, some LED's) on your board. At the moment,
1904 the following checkpoints are implemented:
1906 Legacy uImage format:
1909 1 common/cmd_bootm.c before attempting to boot an image
1910 -1 common/cmd_bootm.c Image header has bad magic number
1911 2 common/cmd_bootm.c Image header has correct magic number
1912 -2 common/cmd_bootm.c Image header has bad checksum
1913 3 common/cmd_bootm.c Image header has correct checksum
1914 -3 common/cmd_bootm.c Image data has bad checksum
1915 4 common/cmd_bootm.c Image data has correct checksum
1916 -4 common/cmd_bootm.c Image is for unsupported architecture
1917 5 common/cmd_bootm.c Architecture check OK
1918 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi)
1919 6 common/cmd_bootm.c Image Type check OK
1920 -6 common/cmd_bootm.c gunzip uncompression error
1921 -7 common/cmd_bootm.c Unimplemented compression type
1922 7 common/cmd_bootm.c Uncompression OK
1923 8 common/cmd_bootm.c No uncompress/copy overwrite error
1924 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX)
1926 9 common/image.c Start initial ramdisk verification
1927 -10 common/image.c Ramdisk header has bad magic number
1928 -11 common/image.c Ramdisk header has bad checksum
1929 10 common/image.c Ramdisk header is OK
1930 -12 common/image.c Ramdisk data has bad checksum
1931 11 common/image.c Ramdisk data has correct checksum
1932 12 common/image.c Ramdisk verification complete, start loading
1933 -13 common/image.c Wrong Image Type (not PPC Linux ramdisk)
1934 13 common/image.c Start multifile image verification
1935 14 common/image.c No initial ramdisk, no multifile, continue.
1937 15 lib_<arch>/bootm.c All preparation done, transferring control to OS
1939 -30 lib_ppc/board.c Fatal error, hang the system
1940 -31 post/post.c POST test failed, detected by post_output_backlog()
1941 -32 post/post.c POST test failed, detected by post_run_single()
1943 34 common/cmd_doc.c before loading a Image from a DOC device
1944 -35 common/cmd_doc.c Bad usage of "doc" command
1945 35 common/cmd_doc.c correct usage of "doc" command
1946 -36 common/cmd_doc.c No boot device
1947 36 common/cmd_doc.c correct boot device
1948 -37 common/cmd_doc.c Unknown Chip ID on boot device
1949 37 common/cmd_doc.c correct chip ID found, device available
1950 -38 common/cmd_doc.c Read Error on boot device
1951 38 common/cmd_doc.c reading Image header from DOC device OK
1952 -39 common/cmd_doc.c Image header has bad magic number
1953 39 common/cmd_doc.c Image header has correct magic number
1954 -40 common/cmd_doc.c Error reading Image from DOC device
1955 40 common/cmd_doc.c Image header has correct magic number
1956 41 common/cmd_ide.c before loading a Image from a IDE device
1957 -42 common/cmd_ide.c Bad usage of "ide" command
1958 42 common/cmd_ide.c correct usage of "ide" command
1959 -43 common/cmd_ide.c No boot device
1960 43 common/cmd_ide.c boot device found
1961 -44 common/cmd_ide.c Device not available
1962 44 common/cmd_ide.c Device available
1963 -45 common/cmd_ide.c wrong partition selected
1964 45 common/cmd_ide.c partition selected
1965 -46 common/cmd_ide.c Unknown partition table
1966 46 common/cmd_ide.c valid partition table found
1967 -47 common/cmd_ide.c Invalid partition type
1968 47 common/cmd_ide.c correct partition type
1969 -48 common/cmd_ide.c Error reading Image Header on boot device
1970 48 common/cmd_ide.c reading Image Header from IDE device OK
1971 -49 common/cmd_ide.c Image header has bad magic number
1972 49 common/cmd_ide.c Image header has correct magic number
1973 -50 common/cmd_ide.c Image header has bad checksum
1974 50 common/cmd_ide.c Image header has correct checksum
1975 -51 common/cmd_ide.c Error reading Image from IDE device
1976 51 common/cmd_ide.c reading Image from IDE device OK
1977 52 common/cmd_nand.c before loading a Image from a NAND device
1978 -53 common/cmd_nand.c Bad usage of "nand" command
1979 53 common/cmd_nand.c correct usage of "nand" command
1980 -54 common/cmd_nand.c No boot device
1981 54 common/cmd_nand.c boot device found
1982 -55 common/cmd_nand.c Unknown Chip ID on boot device
1983 55 common/cmd_nand.c correct chip ID found, device available
1984 -56 common/cmd_nand.c Error reading Image Header on boot device
1985 56 common/cmd_nand.c reading Image Header from NAND device OK
1986 -57 common/cmd_nand.c Image header has bad magic number
1987 57 common/cmd_nand.c Image header has correct magic number
1988 -58 common/cmd_nand.c Error reading Image from NAND device
1989 58 common/cmd_nand.c reading Image from NAND device OK
1991 -60 common/env_common.c Environment has a bad CRC, using default
1993 64 net/eth.c starting with Ethernet configuration.
1994 -64 net/eth.c no Ethernet found.
1995 65 net/eth.c Ethernet found.
1997 -80 common/cmd_net.c usage wrong
1998 80 common/cmd_net.c before calling NetLoop()
1999 -81 common/cmd_net.c some error in NetLoop() occurred
2000 81 common/cmd_net.c NetLoop() back without error
2001 -82 common/cmd_net.c size == 0 (File with size 0 loaded)
2002 82 common/cmd_net.c trying automatic boot
2003 83 common/cmd_net.c running "source" command
2004 -83 common/cmd_net.c some error in automatic boot or "source" command
2005 84 common/cmd_net.c end without errors
2010 100 common/cmd_bootm.c Kernel FIT Image has correct format
2011 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format
2012 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration
2013 -101 common/cmd_bootm.c Can't get configuration for kernel subimage
2014 102 common/cmd_bootm.c Kernel unit name specified
2015 -103 common/cmd_bootm.c Can't get kernel subimage node offset
2016 103 common/cmd_bootm.c Found configuration node
2017 104 common/cmd_bootm.c Got kernel subimage node offset
2018 -104 common/cmd_bootm.c Kernel subimage hash verification failed
2019 105 common/cmd_bootm.c Kernel subimage hash verification OK
2020 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture
2021 106 common/cmd_bootm.c Architecture check OK
2022 -106 common/cmd_bootm.c Kernel subimage has wrong type
2023 107 common/cmd_bootm.c Kernel subimage type OK
2024 -107 common/cmd_bootm.c Can't get kernel subimage data/size
2025 108 common/cmd_bootm.c Got kernel subimage data/size
2026 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT)
2027 -109 common/cmd_bootm.c Can't get kernel subimage type
2028 -110 common/cmd_bootm.c Can't get kernel subimage comp
2029 -111 common/cmd_bootm.c Can't get kernel subimage os
2030 -112 common/cmd_bootm.c Can't get kernel subimage load address
2031 -113 common/cmd_bootm.c Image uncompress/copy overwrite error
2033 120 common/image.c Start initial ramdisk verification
2034 -120 common/image.c Ramdisk FIT image has incorrect format
2035 121 common/image.c Ramdisk FIT image has correct format
2036 122 common/image.c No ramdisk subimage unit name, using configuration
2037 -122 common/image.c Can't get configuration for ramdisk subimage
2038 123 common/image.c Ramdisk unit name specified
2039 -124 common/image.c Can't get ramdisk subimage node offset
2040 125 common/image.c Got ramdisk subimage node offset
2041 -125 common/image.c Ramdisk subimage hash verification failed
2042 126 common/image.c Ramdisk subimage hash verification OK
2043 -126 common/image.c Ramdisk subimage for unsupported architecture
2044 127 common/image.c Architecture check OK
2045 -127 common/image.c Can't get ramdisk subimage data/size
2046 128 common/image.c Got ramdisk subimage data/size
2047 129 common/image.c Can't get ramdisk load address
2048 -129 common/image.c Got ramdisk load address
2050 -130 common/cmd_doc.c Incorrect FIT image format
2051 131 common/cmd_doc.c FIT image format OK
2053 -140 common/cmd_ide.c Incorrect FIT image format
2054 141 common/cmd_ide.c FIT image format OK
2056 -150 common/cmd_nand.c Incorrect FIT image format
2057 151 common/cmd_nand.c FIT image format OK
2059 - Automatic software updates via TFTP server
2061 CONFIG_UPDATE_TFTP_CNT_MAX
2062 CONFIG_UPDATE_TFTP_MSEC_MAX
2064 These options enable and control the auto-update feature;
2065 for a more detailed description refer to doc/README.update.
2067 - MTD Support (mtdparts command, UBI support)
2070 Adds the MTD device infrastructure from the Linux kernel.
2071 Needed for mtdparts command support.
2073 CONFIG_MTD_PARTITIONS
2075 Adds the MTD partitioning infrastructure from the Linux
2076 kernel. Needed for UBI support.
2082 [so far only for SMDK2400 and TRAB boards]
2084 - Modem support enable:
2085 CONFIG_MODEM_SUPPORT
2087 - RTS/CTS Flow control enable:
2090 - Modem debug support:
2091 CONFIG_MODEM_SUPPORT_DEBUG
2093 Enables debugging stuff (char screen[1024], dbg())
2094 for modem support. Useful only with BDI2000.
2096 - Interrupt support (PPC):
2098 There are common interrupt_init() and timer_interrupt()
2099 for all PPC archs. interrupt_init() calls interrupt_init_cpu()
2100 for CPU specific initialization. interrupt_init_cpu()
2101 should set decrementer_count to appropriate value. If
2102 CPU resets decrementer automatically after interrupt
2103 (ppc4xx) it should set decrementer_count to zero.
2104 timer_interrupt() calls timer_interrupt_cpu() for CPU
2105 specific handling. If board has watchdog / status_led
2106 / other_activity_monitor it works automatically from
2107 general timer_interrupt().
2111 In the target system modem support is enabled when a
2112 specific key (key combination) is pressed during
2113 power-on. Otherwise U-Boot will boot normally
2114 (autoboot). The key_pressed() function is called from
2115 board_init(). Currently key_pressed() is a dummy
2116 function, returning 1 and thus enabling modem
2119 If there are no modem init strings in the
2120 environment, U-Boot proceed to autoboot; the
2121 previous output (banner, info printfs) will be
2124 See also: doc/README.Modem
2127 Configuration Settings:
2128 -----------------------
2130 - CONFIG_SYS_LONGHELP: Defined when you want long help messages included;
2131 undefine this when you're short of memory.
2133 - CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default
2134 width of the commands listed in the 'help' command output.
2136 - CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to
2137 prompt for user input.
2139 - CONFIG_SYS_CBSIZE: Buffer size for input from the Console
2141 - CONFIG_SYS_PBSIZE: Buffer size for Console output
2143 - CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands
2145 - CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to
2146 the application (usually a Linux kernel) when it is
2149 - CONFIG_SYS_BAUDRATE_TABLE:
2150 List of legal baudrate settings for this board.
2152 - CONFIG_SYS_CONSOLE_INFO_QUIET
2153 Suppress display of console information at boot.
2155 - CONFIG_SYS_CONSOLE_IS_IN_ENV
2156 If the board specific function
2157 extern int overwrite_console (void);
2158 returns 1, the stdin, stderr and stdout are switched to the
2159 serial port, else the settings in the environment are used.
2161 - CONFIG_SYS_CONSOLE_OVERWRITE_ROUTINE
2162 Enable the call to overwrite_console().
2164 - CONFIG_SYS_CONSOLE_ENV_OVERWRITE
2165 Enable overwrite of previous console environment settings.
2167 - CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END:
2168 Begin and End addresses of the area used by the
2171 - CONFIG_SYS_ALT_MEMTEST:
2172 Enable an alternate, more extensive memory test.
2174 - CONFIG_SYS_MEMTEST_SCRATCH:
2175 Scratch address used by the alternate memory test
2176 You only need to set this if address zero isn't writeable
2178 - CONFIG_SYS_MEM_TOP_HIDE (PPC only):
2179 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header,
2180 this specified memory area will get subtracted from the top
2181 (end) of RAM and won't get "touched" at all by U-Boot. By
2182 fixing up gd->ram_size the Linux kernel should gets passed
2183 the now "corrected" memory size and won't touch it either.
2184 This should work for arch/ppc and arch/powerpc. Only Linux
2185 board ports in arch/powerpc with bootwrapper support that
2186 recalculate the memory size from the SDRAM controller setup
2187 will have to get fixed in Linux additionally.
2189 This option can be used as a workaround for the 440EPx/GRx
2190 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't
2193 WARNING: Please make sure that this value is a multiple of
2194 the Linux page size (normally 4k). If this is not the case,
2195 then the end address of the Linux memory will be located at a
2196 non page size aligned address and this could cause major
2199 - CONFIG_SYS_TFTP_LOADADDR:
2200 Default load address for network file downloads
2202 - CONFIG_SYS_LOADS_BAUD_CHANGE:
2203 Enable temporary baudrate change while serial download
2205 - CONFIG_SYS_SDRAM_BASE:
2206 Physical start address of SDRAM. _Must_ be 0 here.
2208 - CONFIG_SYS_MBIO_BASE:
2209 Physical start address of Motherboard I/O (if using a
2212 - CONFIG_SYS_FLASH_BASE:
2213 Physical start address of Flash memory.
2215 - CONFIG_SYS_MONITOR_BASE:
2216 Physical start address of boot monitor code (set by
2217 make config files to be same as the text base address
2218 (TEXT_BASE) used when linking) - same as
2219 CONFIG_SYS_FLASH_BASE when booting from flash.
2221 - CONFIG_SYS_MONITOR_LEN:
2222 Size of memory reserved for monitor code, used to
2223 determine _at_compile_time_ (!) if the environment is
2224 embedded within the U-Boot image, or in a separate
2227 - CONFIG_SYS_MALLOC_LEN:
2228 Size of DRAM reserved for malloc() use.
2230 - CONFIG_SYS_BOOTM_LEN:
2231 Normally compressed uImages are limited to an
2232 uncompressed size of 8 MBytes. If this is not enough,
2233 you can define CONFIG_SYS_BOOTM_LEN in your board config file
2234 to adjust this setting to your needs.
2236 - CONFIG_SYS_BOOTMAPSZ:
2237 Maximum size of memory mapped by the startup code of
2238 the Linux kernel; all data that must be processed by
2239 the Linux kernel (bd_info, boot arguments, FDT blob if
2240 used) must be put below this limit, unless "bootm_low"
2241 enviroment variable is defined and non-zero. In such case
2242 all data for the Linux kernel must be between "bootm_low"
2243 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ.
2245 - CONFIG_SYS_MAX_FLASH_BANKS:
2246 Max number of Flash memory banks
2248 - CONFIG_SYS_MAX_FLASH_SECT:
2249 Max number of sectors on a Flash chip
2251 - CONFIG_SYS_FLASH_ERASE_TOUT:
2252 Timeout for Flash erase operations (in ms)
2254 - CONFIG_SYS_FLASH_WRITE_TOUT:
2255 Timeout for Flash write operations (in ms)
2257 - CONFIG_SYS_FLASH_LOCK_TOUT
2258 Timeout for Flash set sector lock bit operation (in ms)
2260 - CONFIG_SYS_FLASH_UNLOCK_TOUT
2261 Timeout for Flash clear lock bits operation (in ms)
2263 - CONFIG_SYS_FLASH_PROTECTION
2264 If defined, hardware flash sectors protection is used
2265 instead of U-Boot software protection.
2267 - CONFIG_SYS_DIRECT_FLASH_TFTP:
2269 Enable TFTP transfers directly to flash memory;
2270 without this option such a download has to be
2271 performed in two steps: (1) download to RAM, and (2)
2272 copy from RAM to flash.
2274 The two-step approach is usually more reliable, since
2275 you can check if the download worked before you erase
2276 the flash, but in some situations (when system RAM is
2277 too limited to allow for a temporary copy of the
2278 downloaded image) this option may be very useful.
2280 - CONFIG_SYS_FLASH_CFI:
2281 Define if the flash driver uses extra elements in the
2282 common flash structure for storing flash geometry.
2284 - CONFIG_FLASH_CFI_DRIVER
2285 This option also enables the building of the cfi_flash driver
2286 in the drivers directory
2288 - CONFIG_FLASH_CFI_MTD
2289 This option enables the building of the cfi_mtd driver
2290 in the drivers directory. The driver exports CFI flash
2293 - CONFIG_SYS_FLASH_USE_BUFFER_WRITE
2294 Use buffered writes to flash.
2296 - CONFIG_FLASH_SPANSION_S29WS_N
2297 s29ws-n MirrorBit flash has non-standard addresses for buffered
2300 - CONFIG_SYS_FLASH_QUIET_TEST
2301 If this option is defined, the common CFI flash doesn't
2302 print it's warning upon not recognized FLASH banks. This
2303 is useful, if some of the configured banks are only
2304 optionally available.
2306 - CONFIG_FLASH_SHOW_PROGRESS
2307 If defined (must be an integer), print out countdown
2308 digits and dots. Recommended value: 45 (9..1) for 80
2309 column displays, 15 (3..1) for 40 column displays.
2311 - CONFIG_SYS_RX_ETH_BUFFER:
2312 Defines the number of Ethernet receive buffers. On some
2313 Ethernet controllers it is recommended to set this value
2314 to 8 or even higher (EEPRO100 or 405 EMAC), since all
2315 buffers can be full shortly after enabling the interface
2316 on high Ethernet traffic.
2317 Defaults to 4 if not defined.
2319 The following definitions that deal with the placement and management
2320 of environment data (variable area); in general, we support the
2321 following configurations:
2323 - CONFIG_ENV_IS_IN_FLASH:
2325 Define this if the environment is in flash memory.
2327 a) The environment occupies one whole flash sector, which is
2328 "embedded" in the text segment with the U-Boot code. This
2329 happens usually with "bottom boot sector" or "top boot
2330 sector" type flash chips, which have several smaller
2331 sectors at the start or the end. For instance, such a
2332 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In
2333 such a case you would place the environment in one of the
2334 4 kB sectors - with U-Boot code before and after it. With
2335 "top boot sector" type flash chips, you would put the
2336 environment in one of the last sectors, leaving a gap
2337 between U-Boot and the environment.
2339 - CONFIG_ENV_OFFSET:
2341 Offset of environment data (variable area) to the
2342 beginning of flash memory; for instance, with bottom boot
2343 type flash chips the second sector can be used: the offset
2344 for this sector is given here.
2346 CONFIG_ENV_OFFSET is used relative to CONFIG_SYS_FLASH_BASE.
2350 This is just another way to specify the start address of
2351 the flash sector containing the environment (instead of
2354 - CONFIG_ENV_SECT_SIZE:
2356 Size of the sector containing the environment.
2359 b) Sometimes flash chips have few, equal sized, BIG sectors.
2360 In such a case you don't want to spend a whole sector for
2365 If you use this in combination with CONFIG_ENV_IS_IN_FLASH
2366 and CONFIG_ENV_SECT_SIZE, you can specify to use only a part
2367 of this flash sector for the environment. This saves
2368 memory for the RAM copy of the environment.
2370 It may also save flash memory if you decide to use this
2371 when your environment is "embedded" within U-Boot code,
2372 since then the remainder of the flash sector could be used
2373 for U-Boot code. It should be pointed out that this is
2374 STRONGLY DISCOURAGED from a robustness point of view:
2375 updating the environment in flash makes it always
2376 necessary to erase the WHOLE sector. If something goes
2377 wrong before the contents has been restored from a copy in
2378 RAM, your target system will be dead.
2380 - CONFIG_ENV_ADDR_REDUND
2381 CONFIG_ENV_SIZE_REDUND
2383 These settings describe a second storage area used to hold
2384 a redundant copy of the environment data, so that there is
2385 a valid backup copy in case there is a power failure during
2386 a "saveenv" operation.
2388 BE CAREFUL! Any changes to the flash layout, and some changes to the
2389 source code will make it necessary to adapt <board>/u-boot.lds*
2393 - CONFIG_ENV_IS_IN_NVRAM:
2395 Define this if you have some non-volatile memory device
2396 (NVRAM, battery buffered SRAM) which you want to use for the
2402 These two #defines are used to determine the memory area you
2403 want to use for environment. It is assumed that this memory
2404 can just be read and written to, without any special
2407 BE CAREFUL! The first access to the environment happens quite early
2408 in U-Boot initalization (when we try to get the setting of for the
2409 console baudrate). You *MUST* have mapped your NVRAM area then, or
2412 Please note that even with NVRAM we still use a copy of the
2413 environment in RAM: we could work on NVRAM directly, but we want to
2414 keep settings there always unmodified except somebody uses "saveenv"
2415 to save the current settings.
2418 - CONFIG_ENV_IS_IN_EEPROM:
2420 Use this if you have an EEPROM or similar serial access
2421 device and a driver for it.
2423 - CONFIG_ENV_OFFSET:
2426 These two #defines specify the offset and size of the
2427 environment area within the total memory of your EEPROM.
2429 - CONFIG_SYS_I2C_EEPROM_ADDR:
2430 If defined, specified the chip address of the EEPROM device.
2431 The default address is zero.
2433 - CONFIG_SYS_EEPROM_PAGE_WRITE_BITS:
2434 If defined, the number of bits used to address bytes in a
2435 single page in the EEPROM device. A 64 byte page, for example
2436 would require six bits.
2438 - CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS:
2439 If defined, the number of milliseconds to delay between
2440 page writes. The default is zero milliseconds.
2442 - CONFIG_SYS_I2C_EEPROM_ADDR_LEN:
2443 The length in bytes of the EEPROM memory array address. Note
2444 that this is NOT the chip address length!
2446 - CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW:
2447 EEPROM chips that implement "address overflow" are ones
2448 like Catalyst 24WC04/08/16 which has 9/10/11 bits of
2449 address and the extra bits end up in the "chip address" bit
2450 slots. This makes a 24WC08 (1Kbyte) chip look like four 256
2453 Note that we consider the length of the address field to
2454 still be one byte because the extra address bits are hidden
2455 in the chip address.
2457 - CONFIG_SYS_EEPROM_SIZE:
2458 The size in bytes of the EEPROM device.
2460 - CONFIG_ENV_EEPROM_IS_ON_I2C
2461 define this, if you have I2C and SPI activated, and your
2462 EEPROM, which holds the environment, is on the I2C bus.
2464 - CONFIG_I2C_ENV_EEPROM_BUS
2465 if you have an Environment on an EEPROM reached over
2466 I2C muxes, you can define here, how to reach this
2467 EEPROM. For example:
2469 #define CONFIG_I2C_ENV_EEPROM_BUS "pca9547:70:d\0"
2471 EEPROM which holds the environment, is reached over
2472 a pca9547 i2c mux with address 0x70, channel 3.
2474 - CONFIG_ENV_IS_IN_DATAFLASH:
2476 Define this if you have a DataFlash memory device which you
2477 want to use for the environment.
2479 - CONFIG_ENV_OFFSET:
2483 These three #defines specify the offset and size of the
2484 environment area within the total memory of your DataFlash placed
2485 at the specified address.
2487 - CONFIG_ENV_IS_IN_NAND:
2489 Define this if you have a NAND device which you want to use
2490 for the environment.
2492 - CONFIG_ENV_OFFSET:
2495 These two #defines specify the offset and size of the environment
2496 area within the first NAND device.
2498 - CONFIG_ENV_OFFSET_REDUND
2500 This setting describes a second storage area of CONFIG_ENV_SIZE
2501 size used to hold a redundant copy of the environment data,
2502 so that there is a valid backup copy in case there is a
2503 power failure during a "saveenv" operation.
2505 Note: CONFIG_ENV_OFFSET and CONFIG_ENV_OFFSET_REDUND must be aligned
2506 to a block boundary, and CONFIG_ENV_SIZE must be a multiple of
2507 the NAND devices block size.
2509 - CONFIG_NAND_ENV_DST
2511 Defines address in RAM to which the nand_spl code should copy the
2512 environment. If redundant environment is used, it will be copied to
2513 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE.
2515 - CONFIG_SYS_SPI_INIT_OFFSET
2517 Defines offset to the initial SPI buffer area in DPRAM. The
2518 area is used at an early stage (ROM part) if the environment
2519 is configured to reside in the SPI EEPROM: We need a 520 byte
2520 scratch DPRAM area. It is used between the two initialization
2521 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems
2522 to be a good choice since it makes it far enough from the
2523 start of the data area as well as from the stack pointer.
2525 Please note that the environment is read-only until the monitor
2526 has been relocated to RAM and a RAM copy of the environment has been
2527 created; also, when using EEPROM you will have to use getenv_r()
2528 until then to read environment variables.
2530 The environment is protected by a CRC32 checksum. Before the monitor
2531 is relocated into RAM, as a result of a bad CRC you will be working
2532 with the compiled-in default environment - *silently*!!! [This is
2533 necessary, because the first environment variable we need is the
2534 "baudrate" setting for the console - if we have a bad CRC, we don't
2535 have any device yet where we could complain.]
2537 Note: once the monitor has been relocated, then it will complain if
2538 the default environment is used; a new CRC is computed as soon as you
2539 use the "saveenv" command to store a valid environment.
2541 - CONFIG_SYS_FAULT_ECHO_LINK_DOWN:
2542 Echo the inverted Ethernet link state to the fault LED.
2544 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR
2545 also needs to be defined.
2547 - CONFIG_SYS_FAULT_MII_ADDR:
2548 MII address of the PHY to check for the Ethernet link state.
2550 - CONFIG_NS16550_MIN_FUNCTIONS:
2551 Define this if you desire to only have use of the NS16550_init
2552 and NS16550_putc functions for the serial driver located at
2553 drivers/serial/ns16550.c. This option is useful for saving
2554 space for already greatly restricted images, including but not
2555 limited to NAND_SPL configurations.
2557 Low Level (hardware related) configuration options:
2558 ---------------------------------------------------
2560 - CONFIG_SYS_CACHELINE_SIZE:
2561 Cache Line Size of the CPU.
2563 - CONFIG_SYS_DEFAULT_IMMR:
2564 Default address of the IMMR after system reset.
2566 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU,
2567 and RPXsuper) to be able to adjust the position of
2568 the IMMR register after a reset.
2570 - Floppy Disk Support:
2571 CONFIG_SYS_FDC_DRIVE_NUMBER
2573 the default drive number (default value 0)
2575 CONFIG_SYS_ISA_IO_STRIDE
2577 defines the spacing between FDC chipset registers
2580 CONFIG_SYS_ISA_IO_OFFSET
2582 defines the offset of register from address. It
2583 depends on which part of the data bus is connected to
2584 the FDC chipset. (default value 0)
2586 If CONFIG_SYS_ISA_IO_STRIDE CONFIG_SYS_ISA_IO_OFFSET and
2587 CONFIG_SYS_FDC_DRIVE_NUMBER are undefined, they take their
2590 if CONFIG_SYS_FDC_HW_INIT is defined, then the function
2591 fdc_hw_init() is called at the beginning of the FDC
2592 setup. fdc_hw_init() must be provided by the board
2593 source code. It is used to make hardware dependant
2596 - CONFIG_SYS_IMMR: Physical address of the Internal Memory.
2597 DO NOT CHANGE unless you know exactly what you're
2598 doing! (11-4) [MPC8xx/82xx systems only]
2600 - CONFIG_SYS_INIT_RAM_ADDR:
2602 Start address of memory area that can be used for
2603 initial data and stack; please note that this must be
2604 writable memory that is working WITHOUT special
2605 initialization, i. e. you CANNOT use normal RAM which
2606 will become available only after programming the
2607 memory controller and running certain initialization
2610 U-Boot uses the following memory types:
2611 - MPC8xx and MPC8260: IMMR (internal memory of the CPU)
2612 - MPC824X: data cache
2613 - PPC4xx: data cache
2615 - CONFIG_SYS_GBL_DATA_OFFSET:
2617 Offset of the initial data structure in the memory
2618 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually
2619 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial
2620 data is located at the end of the available space
2621 (sometimes written as (CONFIG_SYS_INIT_RAM_END -
2622 CONFIG_SYS_INIT_DATA_SIZE), and the initial stack is just
2623 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR +
2624 CONFIG_SYS_GBL_DATA_OFFSET) downward.
2627 On the MPC824X (or other systems that use the data
2628 cache for initial memory) the address chosen for
2629 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must
2630 point to an otherwise UNUSED address space between
2631 the top of RAM and the start of the PCI space.
2633 - CONFIG_SYS_SIUMCR: SIU Module Configuration (11-6)
2635 - CONFIG_SYS_SYPCR: System Protection Control (11-9)
2637 - CONFIG_SYS_TBSCR: Time Base Status and Control (11-26)
2639 - CONFIG_SYS_PISCR: Periodic Interrupt Status and Control (11-31)
2641 - CONFIG_SYS_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30)
2643 - CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27)
2645 - CONFIG_SYS_OR_TIMING_SDRAM:
2648 - CONFIG_SYS_MAMR_PTA:
2649 periodic timer for refresh
2651 - CONFIG_SYS_DER: Debug Event Register (37-47)
2653 - FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM,
2654 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP,
2655 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM,
2656 CONFIG_SYS_BR1_PRELIM:
2657 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
2659 - SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
2660 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM,
2661 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM:
2662 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
2664 - CONFIG_SYS_MAMR_PTA, CONFIG_SYS_MPTPR_2BK_4K, CONFIG_SYS_MPTPR_1BK_4K, CONFIG_SYS_MPTPR_2BK_8K,
2665 CONFIG_SYS_MPTPR_1BK_8K, CONFIG_SYS_MAMR_8COL, CONFIG_SYS_MAMR_9COL:
2666 Machine Mode Register and Memory Periodic Timer
2667 Prescaler definitions (SDRAM timing)
2669 - CONFIG_SYS_I2C_UCODE_PATCH, CONFIG_SYS_I2C_DPMEM_OFFSET [0x1FC0]:
2670 enable I2C microcode relocation patch (MPC8xx);
2671 define relocation offset in DPRAM [DSP2]
2673 - CONFIG_SYS_SMC_UCODE_PATCH, CONFIG_SYS_SMC_DPMEM_OFFSET [0x1FC0]:
2674 enable SMC microcode relocation patch (MPC8xx);
2675 define relocation offset in DPRAM [SMC1]
2677 - CONFIG_SYS_SPI_UCODE_PATCH, CONFIG_SYS_SPI_DPMEM_OFFSET [0x1FC0]:
2678 enable SPI microcode relocation patch (MPC8xx);
2679 define relocation offset in DPRAM [SCC4]
2681 - CONFIG_SYS_USE_OSCCLK:
2682 Use OSCM clock mode on MBX8xx board. Be careful,
2683 wrong setting might damage your board. Read
2684 doc/README.MBX before setting this variable!
2686 - CONFIG_SYS_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only)
2687 Offset of the bootmode word in DPRAM used by post
2688 (Power On Self Tests). This definition overrides
2689 #define'd default value in commproc.h resp.
2692 - CONFIG_SYS_PCI_SLV_MEM_LOCAL, CONFIG_SYS_PCI_SLV_MEM_BUS, CONFIG_SYS_PICMR0_MASK_ATTRIB,
2693 CONFIG_SYS_PCI_MSTR0_LOCAL, CONFIG_SYS_PCIMSK0_MASK, CONFIG_SYS_PCI_MSTR1_LOCAL,
2694 CONFIG_SYS_PCIMSK1_MASK, CONFIG_SYS_PCI_MSTR_MEM_LOCAL, CONFIG_SYS_PCI_MSTR_MEM_BUS,
2695 CONFIG_SYS_CPU_PCI_MEM_START, CONFIG_SYS_PCI_MSTR_MEM_SIZE, CONFIG_SYS_POCMR0_MASK_ATTRIB,
2696 CONFIG_SYS_PCI_MSTR_MEMIO_LOCAL, CONFIG_SYS_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START,
2697 CONFIG_SYS_PCI_MSTR_MEMIO_SIZE, CONFIG_SYS_POCMR1_MASK_ATTRIB, CONFIG_SYS_PCI_MSTR_IO_LOCAL,
2698 CONFIG_SYS_PCI_MSTR_IO_BUS, CONFIG_SYS_CPU_PCI_IO_START, CONFIG_SYS_PCI_MSTR_IO_SIZE,
2699 CONFIG_SYS_POCMR2_MASK_ATTRIB: (MPC826x only)
2700 Overrides the default PCI memory map in cpu/mpc8260/pci.c if set.
2702 - CONFIG_PCI_DISABLE_PCIE:
2703 Disable PCI-Express on systems where it is supported but not
2707 Get DDR timing information from an I2C EEPROM. Common
2708 with pluggable memory modules such as SODIMMs
2711 I2C address of the SPD EEPROM
2713 - CONFIG_SYS_SPD_BUS_NUM
2714 If SPD EEPROM is on an I2C bus other than the first
2715 one, specify here. Note that the value must resolve
2716 to something your driver can deal with.
2718 - CONFIG_SYS_83XX_DDR_USES_CS0
2719 Only for 83xx systems. If specified, then DDR should
2720 be configured using CS0 and CS1 instead of CS2 and CS3.
2722 - CONFIG_ETHER_ON_FEC[12]
2723 Define to enable FEC[12] on a 8xx series processor.
2725 - CONFIG_FEC[12]_PHY
2726 Define to the hardcoded PHY address which corresponds
2727 to the given FEC; i. e.
2728 #define CONFIG_FEC1_PHY 4
2729 means that the PHY with address 4 is connected to FEC1
2731 When set to -1, means to probe for first available.
2733 - CONFIG_FEC[12]_PHY_NORXERR
2734 The PHY does not have a RXERR line (RMII only).
2735 (so program the FEC to ignore it).
2738 Enable RMII mode for all FECs.
2739 Note that this is a global option, we can't
2740 have one FEC in standard MII mode and another in RMII mode.
2742 - CONFIG_CRC32_VERIFY
2743 Add a verify option to the crc32 command.
2746 => crc32 -v <address> <count> <crc32>
2748 Where address/count indicate a memory area
2749 and crc32 is the correct crc32 which the
2753 Add the "loopw" memory command. This only takes effect if
2754 the memory commands are activated globally (CONFIG_CMD_MEM).
2757 Add the "mdc" and "mwc" memory commands. These are cyclic
2762 This command will print 4 bytes (10,11,12,13) each 500 ms.
2764 => mwc.l 100 12345678 10
2765 This command will write 12345678 to address 100 all 10 ms.
2767 This only takes effect if the memory commands are activated
2768 globally (CONFIG_CMD_MEM).
2770 - CONFIG_SKIP_LOWLEVEL_INIT
2771 - CONFIG_SKIP_RELOCATE_UBOOT
2773 [ARM only] If these variables are defined, then
2774 certain low level initializations (like setting up
2775 the memory controller) are omitted and/or U-Boot does
2776 not relocate itself into RAM.
2777 Normally these variables MUST NOT be defined. The
2778 only exception is when U-Boot is loaded (to RAM) by
2779 some other boot loader or by a debugger which
2780 performs these initializations itself.
2784 Modifies the behaviour of start.S when compiling a loader
2785 that is executed before the actual U-Boot. E.g. when
2786 compiling a NAND SPL.
2788 Building the Software:
2789 ======================
2791 Building U-Boot has been tested in several native build environments
2792 and in many different cross environments. Of course we cannot support
2793 all possibly existing versions of cross development tools in all
2794 (potentially obsolete) versions. In case of tool chain problems we
2795 recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK)
2796 which is extensively used to build and test U-Boot.
2798 If you are not using a native environment, it is assumed that you
2799 have GNU cross compiling tools available in your path. In this case,
2800 you must set the environment variable CROSS_COMPILE in your shell.
2801 Note that no changes to the Makefile or any other source files are
2802 necessary. For example using the ELDK on a 4xx CPU, please enter:
2804 $ CROSS_COMPILE=ppc_4xx-
2805 $ export CROSS_COMPILE
2807 Note: If you wish to generate Windows versions of the utilities in
2808 the tools directory you can use the MinGW toolchain
2809 (http://www.mingw.org). Set your HOST tools to the MinGW
2810 toolchain and execute 'make tools'. For example:
2812 $ make HOSTCC=i586-mingw32msvc-gcc HOSTSTRIP=i586-mingw32msvc-strip tools
2814 Binaries such as tools/mkimage.exe will be created which can
2815 be executed on computers running Windows.
2817 U-Boot is intended to be simple to build. After installing the
2818 sources you must configure U-Boot for one specific board type. This
2823 where "NAME_config" is the name of one of the existing configu-
2824 rations; see the main Makefile for supported names.
2826 Note: for some board special configuration names may exist; check if
2827 additional information is available from the board vendor; for
2828 instance, the TQM823L systems are available without (standard)
2829 or with LCD support. You can select such additional "features"
2830 when choosing the configuration, i. e.
2833 - will configure for a plain TQM823L, i. e. no LCD support
2835 make TQM823L_LCD_config
2836 - will configure for a TQM823L with U-Boot console on LCD
2841 Finally, type "make all", and you should get some working U-Boot
2842 images ready for download to / installation on your system:
2844 - "u-boot.bin" is a raw binary image
2845 - "u-boot" is an image in ELF binary format
2846 - "u-boot.srec" is in Motorola S-Record format
2848 By default the build is performed locally and the objects are saved
2849 in the source directory. One of the two methods can be used to change
2850 this behavior and build U-Boot to some external directory:
2852 1. Add O= to the make command line invocations:
2854 make O=/tmp/build distclean
2855 make O=/tmp/build NAME_config
2856 make O=/tmp/build all
2858 2. Set environment variable BUILD_DIR to point to the desired location:
2860 export BUILD_DIR=/tmp/build
2865 Note that the command line "O=" setting overrides the BUILD_DIR environment
2869 Please be aware that the Makefiles assume you are using GNU make, so
2870 for instance on NetBSD you might need to use "gmake" instead of
2874 If the system board that you have is not listed, then you will need
2875 to port U-Boot to your hardware platform. To do this, follow these
2878 1. Add a new configuration option for your board to the toplevel
2879 "Makefile" and to the "MAKEALL" script, using the existing
2880 entries as examples. Note that here and at many other places
2881 boards and other names are listed in alphabetical sort order. Please
2883 2. Create a new directory to hold your board specific code. Add any
2884 files you need. In your board directory, you will need at least
2885 the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds".
2886 3. Create a new configuration file "include/configs/<board>.h" for
2888 3. If you're porting U-Boot to a new CPU, then also create a new
2889 directory to hold your CPU specific code. Add any files you need.
2890 4. Run "make <board>_config" with your new name.
2891 5. Type "make", and you should get a working "u-boot.srec" file
2892 to be installed on your target system.
2893 6. Debug and solve any problems that might arise.
2894 [Of course, this last step is much harder than it sounds.]
2897 Testing of U-Boot Modifications, Ports to New Hardware, etc.:
2898 ==============================================================
2900 If you have modified U-Boot sources (for instance added a new board
2901 or support for new devices, a new CPU, etc.) you are expected to
2902 provide feedback to the other developers. The feedback normally takes
2903 the form of a "patch", i. e. a context diff against a certain (latest
2904 official or latest in the git repository) version of U-Boot sources.
2906 But before you submit such a patch, please verify that your modifi-
2907 cation did not break existing code. At least make sure that *ALL* of
2908 the supported boards compile WITHOUT ANY compiler warnings. To do so,
2909 just run the "MAKEALL" script, which will configure and build U-Boot
2910 for ALL supported system. Be warned, this will take a while. You can
2911 select which (cross) compiler to use by passing a `CROSS_COMPILE'
2912 environment variable to the script, i. e. to use the ELDK cross tools
2915 CROSS_COMPILE=ppc_8xx- MAKEALL
2917 or to build on a native PowerPC system you can type
2919 CROSS_COMPILE=' ' MAKEALL
2921 When using the MAKEALL script, the default behaviour is to build
2922 U-Boot in the source directory. This location can be changed by
2923 setting the BUILD_DIR environment variable. Also, for each target
2924 built, the MAKEALL script saves two log files (<target>.ERR and
2925 <target>.MAKEALL) in the <source dir>/LOG directory. This default
2926 location can be changed by setting the MAKEALL_LOGDIR environment
2927 variable. For example:
2929 export BUILD_DIR=/tmp/build
2930 export MAKEALL_LOGDIR=/tmp/log
2931 CROSS_COMPILE=ppc_8xx- MAKEALL
2933 With the above settings build objects are saved in the /tmp/build,
2934 log files are saved in the /tmp/log and the source tree remains clean
2935 during the whole build process.
2938 See also "U-Boot Porting Guide" below.
2941 Monitor Commands - Overview:
2942 ============================
2944 go - start application at address 'addr'
2945 run - run commands in an environment variable
2946 bootm - boot application image from memory
2947 bootp - boot image via network using BootP/TFTP protocol
2948 tftpboot- boot image via network using TFTP protocol
2949 and env variables "ipaddr" and "serverip"
2950 (and eventually "gatewayip")
2951 rarpboot- boot image via network using RARP/TFTP protocol
2952 diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
2953 loads - load S-Record file over serial line
2954 loadb - load binary file over serial line (kermit mode)
2956 mm - memory modify (auto-incrementing)
2957 nm - memory modify (constant address)
2958 mw - memory write (fill)
2960 cmp - memory compare
2961 crc32 - checksum calculation
2962 i2c - I2C sub-system
2963 sspi - SPI utility commands
2964 base - print or set address offset
2965 printenv- print environment variables
2966 setenv - set environment variables
2967 saveenv - save environment variables to persistent storage
2968 protect - enable or disable FLASH write protection
2969 erase - erase FLASH memory
2970 flinfo - print FLASH memory information
2971 bdinfo - print Board Info structure
2972 iminfo - print header information for application image
2973 coninfo - print console devices and informations
2974 ide - IDE sub-system
2975 loop - infinite loop on address range
2976 loopw - infinite write loop on address range
2977 mtest - simple RAM test
2978 icache - enable or disable instruction cache
2979 dcache - enable or disable data cache
2980 reset - Perform RESET of the CPU
2981 echo - echo args to console
2982 version - print monitor version
2983 help - print online help
2984 ? - alias for 'help'
2987 Monitor Commands - Detailed Description:
2988 ========================================
2992 For now: just type "help <command>".
2995 Environment Variables:
2996 ======================
2998 U-Boot supports user configuration using Environment Variables which
2999 can be made persistent by saving to Flash memory.
3001 Environment Variables are set using "setenv", printed using
3002 "printenv", and saved to Flash using "saveenv". Using "setenv"
3003 without a value can be used to delete a variable from the
3004 environment. As long as you don't save the environment you are
3005 working with an in-memory copy. In case the Flash area containing the
3006 environment is erased by accident, a default environment is provided.
3008 Some configuration options can be set using Environment Variables.
3010 List of environment variables (most likely not complete):
3012 baudrate - see CONFIG_BAUDRATE
3014 bootdelay - see CONFIG_BOOTDELAY
3016 bootcmd - see CONFIG_BOOTCOMMAND
3018 bootargs - Boot arguments when booting an RTOS image
3020 bootfile - Name of the image to load with TFTP
3022 bootm_low - Memory range available for image processing in the bootm
3023 command can be restricted. This variable is given as
3024 a hexadecimal number and defines lowest address allowed
3025 for use by the bootm command. See also "bootm_size"
3026 environment variable. Address defined by "bootm_low" is
3027 also the base of the initial memory mapping for the Linux
3028 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ.
3030 bootm_size - Memory range available for image processing in the bootm
3031 command can be restricted. This variable is given as
3032 a hexadecimal number and defines the size of the region
3033 allowed for use by the bootm command. See also "bootm_low"
3034 environment variable.
3036 updatefile - Location of the software update file on a TFTP server, used
3037 by the automatic software update feature. Please refer to
3038 documentation in doc/README.update for more details.
3040 autoload - if set to "no" (any string beginning with 'n'),
3041 "bootp" will just load perform a lookup of the
3042 configuration from the BOOTP server, but not try to
3043 load any image using TFTP
3045 autostart - if set to "yes", an image loaded using the "bootp",
3046 "rarpboot", "tftpboot" or "diskboot" commands will
3047 be automatically started (by internally calling
3050 If set to "no", a standalone image passed to the
3051 "bootm" command will be copied to the load address
3052 (and eventually uncompressed), but NOT be started.
3053 This can be used to load and uncompress arbitrary
3056 i2cfast - (PPC405GP|PPC405EP only)
3057 if set to 'y' configures Linux I2C driver for fast
3058 mode (400kHZ). This environment variable is used in
3059 initialization code. So, for changes to be effective
3060 it must be saved and board must be reset.
3062 initrd_high - restrict positioning of initrd images:
3063 If this variable is not set, initrd images will be
3064 copied to the highest possible address in RAM; this
3065 is usually what you want since it allows for
3066 maximum initrd size. If for some reason you want to
3067 make sure that the initrd image is loaded below the
3068 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment
3069 variable to a value of "no" or "off" or "0".
3070 Alternatively, you can set it to a maximum upper
3071 address to use (U-Boot will still check that it
3072 does not overwrite the U-Boot stack and data).
3074 For instance, when you have a system with 16 MB
3075 RAM, and want to reserve 4 MB from use by Linux,
3076 you can do this by adding "mem=12M" to the value of
3077 the "bootargs" variable. However, now you must make
3078 sure that the initrd image is placed in the first
3079 12 MB as well - this can be done with
3081 setenv initrd_high 00c00000
3083 If you set initrd_high to 0xFFFFFFFF, this is an
3084 indication to U-Boot that all addresses are legal
3085 for the Linux kernel, including addresses in flash
3086 memory. In this case U-Boot will NOT COPY the
3087 ramdisk at all. This may be useful to reduce the
3088 boot time on your system, but requires that this
3089 feature is supported by your Linux kernel.
3091 ipaddr - IP address; needed for tftpboot command
3093 loadaddr - Default load address for commands like "bootp",
3094 "rarpboot", "tftpboot", "loadb" or "diskboot"
3096 loads_echo - see CONFIG_LOADS_ECHO
3098 serverip - TFTP server IP address; needed for tftpboot command
3100 bootretry - see CONFIG_BOOT_RETRY_TIME
3102 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
3104 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
3106 ethprime - When CONFIG_NET_MULTI is enabled controls which
3107 interface is used first.
3109 ethact - When CONFIG_NET_MULTI is enabled controls which
3110 interface is currently active. For example you
3111 can do the following
3113 => setenv ethact FEC ETHERNET
3114 => ping 192.168.0.1 # traffic sent on FEC ETHERNET
3115 => setenv ethact SCC ETHERNET
3116 => ping 10.0.0.1 # traffic sent on SCC ETHERNET
3118 ethrotate - When set to "no" U-Boot does not go through all
3119 available network interfaces.
3120 It just stays at the currently selected interface.
3122 netretry - When set to "no" each network operation will
3123 either succeed or fail without retrying.
3124 When set to "once" the network operation will
3125 fail when all the available network interfaces
3126 are tried once without success.
3127 Useful on scripts which control the retry operation
3130 npe_ucode - set load address for the NPE microcode
3132 tftpsrcport - If this is set, the value is used for TFTP's
3135 tftpdstport - If this is set, the value is used for TFTP's UDP
3136 destination port instead of the Well Know Port 69.
3138 tftpblocksize - Block size to use for TFTP transfers; if not set,
3139 we use the TFTP server's default block size
3141 tftptimeout - Retransmission timeout for TFTP packets (in milli-
3142 seconds, minimum value is 1000 = 1 second). Defines
3143 when a packet is considered to be lost so it has to
3144 be retransmitted. The default is 5000 = 5 seconds.
3145 Lowering this value may make downloads succeed
3146 faster in networks with high packet loss rates or
3147 with unreliable TFTP servers.
3149 vlan - When set to a value < 4095 the traffic over
3150 Ethernet is encapsulated/received over 802.1q
3153 The following environment variables may be used and automatically
3154 updated by the network boot commands ("bootp" and "rarpboot"),
3155 depending the information provided by your boot server:
3157 bootfile - see above
3158 dnsip - IP address of your Domain Name Server
3159 dnsip2 - IP address of your secondary Domain Name Server
3160 gatewayip - IP address of the Gateway (Router) to use
3161 hostname - Target hostname
3163 netmask - Subnet Mask
3164 rootpath - Pathname of the root filesystem on the NFS server
3165 serverip - see above
3168 There are two special Environment Variables:
3170 serial# - contains hardware identification information such
3171 as type string and/or serial number
3172 ethaddr - Ethernet address
3174 These variables can be set only once (usually during manufacturing of
3175 the board). U-Boot refuses to delete or overwrite these variables
3176 once they have been set once.
3179 Further special Environment Variables:
3181 ver - Contains the U-Boot version string as printed
3182 with the "version" command. This variable is
3183 readonly (see CONFIG_VERSION_VARIABLE).
3186 Please note that changes to some configuration parameters may take
3187 only effect after the next boot (yes, that's just like Windoze :-).
3190 Command Line Parsing:
3191 =====================
3193 There are two different command line parsers available with U-Boot:
3194 the old "simple" one, and the much more powerful "hush" shell:
3196 Old, simple command line parser:
3197 --------------------------------
3199 - supports environment variables (through setenv / saveenv commands)
3200 - several commands on one line, separated by ';'
3201 - variable substitution using "... ${name} ..." syntax
3202 - special characters ('$', ';') can be escaped by prefixing with '\',
3204 setenv bootcmd bootm \${address}
3205 - You can also escape text by enclosing in single apostrophes, for example:
3206 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
3211 - similar to Bourne shell, with control structures like
3212 if...then...else...fi, for...do...done; while...do...done,
3213 until...do...done, ...
3214 - supports environment ("global") variables (through setenv / saveenv
3215 commands) and local shell variables (through standard shell syntax
3216 "name=value"); only environment variables can be used with "run"
3222 (1) If a command line (or an environment variable executed by a "run"
3223 command) contains several commands separated by semicolon, and
3224 one of these commands fails, then the remaining commands will be
3227 (2) If you execute several variables with one call to run (i. e.
3228 calling run with a list of variables as arguments), any failing
3229 command will cause "run" to terminate, i. e. the remaining
3230 variables are not executed.
3232 Note for Redundant Ethernet Interfaces:
3233 =======================================
3235 Some boards come with redundant Ethernet interfaces; U-Boot supports
3236 such configurations and is capable of automatic selection of a
3237 "working" interface when needed. MAC assignment works as follows:
3239 Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
3240 MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
3241 "eth1addr" (=>eth1), "eth2addr", ...
3243 If the network interface stores some valid MAC address (for instance
3244 in SROM), this is used as default address if there is NO correspon-
3245 ding setting in the environment; if the corresponding environment
3246 variable is set, this overrides the settings in the card; that means:
3248 o If the SROM has a valid MAC address, and there is no address in the
3249 environment, the SROM's address is used.
3251 o If there is no valid address in the SROM, and a definition in the
3252 environment exists, then the value from the environment variable is
3255 o If both the SROM and the environment contain a MAC address, and
3256 both addresses are the same, this MAC address is used.
3258 o If both the SROM and the environment contain a MAC address, and the
3259 addresses differ, the value from the environment is used and a
3262 o If neither SROM nor the environment contain a MAC address, an error
3269 U-Boot is capable of booting (and performing other auxiliary operations on)
3270 images in two formats:
3272 New uImage format (FIT)
3273 -----------------------
3275 Flexible and powerful format based on Flattened Image Tree -- FIT (similar
3276 to Flattened Device Tree). It allows the use of images with multiple
3277 components (several kernels, ramdisks, etc.), with contents protected by
3278 SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory.
3284 Old image format is based on binary files which can be basically anything,
3285 preceded by a special header; see the definitions in include/image.h for
3286 details; basically, the header defines the following image properties:
3288 * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
3289 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
3290 LynxOS, pSOS, QNX, RTEMS, INTEGRITY;
3291 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS,
3293 * Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86,
3294 IA64, MIPS, NIOS, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
3295 Currently supported: ARM, AVR32, Intel x86, MIPS, NIOS, PowerPC).
3296 * Compression Type (uncompressed, gzip, bzip2)
3302 The header is marked by a special Magic Number, and both the header
3303 and the data portions of the image are secured against corruption by
3310 Although U-Boot should support any OS or standalone application
3311 easily, the main focus has always been on Linux during the design of
3314 U-Boot includes many features that so far have been part of some
3315 special "boot loader" code within the Linux kernel. Also, any
3316 "initrd" images to be used are no longer part of one big Linux image;
3317 instead, kernel and "initrd" are separate images. This implementation
3318 serves several purposes:
3320 - the same features can be used for other OS or standalone
3321 applications (for instance: using compressed images to reduce the
3322 Flash memory footprint)
3324 - it becomes much easier to port new Linux kernel versions because
3325 lots of low-level, hardware dependent stuff are done by U-Boot
3327 - the same Linux kernel image can now be used with different "initrd"
3328 images; of course this also means that different kernel images can
3329 be run with the same "initrd". This makes testing easier (you don't
3330 have to build a new "zImage.initrd" Linux image when you just
3331 change a file in your "initrd"). Also, a field-upgrade of the
3332 software is easier now.
3338 Porting Linux to U-Boot based systems:
3339 ---------------------------------------
3341 U-Boot cannot save you from doing all the necessary modifications to
3342 configure the Linux device drivers for use with your target hardware
3343 (no, we don't intend to provide a full virtual machine interface to
3346 But now you can ignore ALL boot loader code (in arch/ppc/mbxboot).
3348 Just make sure your machine specific header file (for instance
3349 include/asm-ppc/tqm8xx.h) includes the same definition of the Board
3350 Information structure as we define in include/asm-<arch>/u-boot.h,
3351 and make sure that your definition of IMAP_ADDR uses the same value
3352 as your U-Boot configuration in CONFIG_SYS_IMMR.
3355 Configuring the Linux kernel:
3356 -----------------------------
3358 No specific requirements for U-Boot. Make sure you have some root
3359 device (initial ramdisk, NFS) for your target system.
3362 Building a Linux Image:
3363 -----------------------
3365 With U-Boot, "normal" build targets like "zImage" or "bzImage" are
3366 not used. If you use recent kernel source, a new build target
3367 "uImage" will exist which automatically builds an image usable by
3368 U-Boot. Most older kernels also have support for a "pImage" target,
3369 which was introduced for our predecessor project PPCBoot and uses a
3370 100% compatible format.
3379 The "uImage" build target uses a special tool (in 'tools/mkimage') to
3380 encapsulate a compressed Linux kernel image with header information,
3381 CRC32 checksum etc. for use with U-Boot. This is what we are doing:
3383 * build a standard "vmlinux" kernel image (in ELF binary format):
3385 * convert the kernel into a raw binary image:
3387 ${CROSS_COMPILE}-objcopy -O binary \
3388 -R .note -R .comment \
3389 -S vmlinux linux.bin
3391 * compress the binary image:
3395 * package compressed binary image for U-Boot:
3397 mkimage -A ppc -O linux -T kernel -C gzip \
3398 -a 0 -e 0 -n "Linux Kernel Image" \
3399 -d linux.bin.gz uImage
3402 The "mkimage" tool can also be used to create ramdisk images for use
3403 with U-Boot, either separated from the Linux kernel image, or
3404 combined into one file. "mkimage" encapsulates the images with a 64
3405 byte header containing information about target architecture,
3406 operating system, image type, compression method, entry points, time
3407 stamp, CRC32 checksums, etc.
3409 "mkimage" can be called in two ways: to verify existing images and
3410 print the header information, or to build new images.
3412 In the first form (with "-l" option) mkimage lists the information
3413 contained in the header of an existing U-Boot image; this includes
3414 checksum verification:
3416 tools/mkimage -l image
3417 -l ==> list image header information
3419 The second form (with "-d" option) is used to build a U-Boot image
3420 from a "data file" which is used as image payload:
3422 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
3423 -n name -d data_file image
3424 -A ==> set architecture to 'arch'
3425 -O ==> set operating system to 'os'
3426 -T ==> set image type to 'type'
3427 -C ==> set compression type 'comp'
3428 -a ==> set load address to 'addr' (hex)
3429 -e ==> set entry point to 'ep' (hex)
3430 -n ==> set image name to 'name'
3431 -d ==> use image data from 'datafile'
3433 Right now, all Linux kernels for PowerPC systems use the same load
3434 address (0x00000000), but the entry point address depends on the
3437 - 2.2.x kernels have the entry point at 0x0000000C,
3438 - 2.3.x and later kernels have the entry point at 0x00000000.
3440 So a typical call to build a U-Boot image would read:
3442 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
3443 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
3444 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux.gz \
3445 > examples/uImage.TQM850L
3446 Image Name: 2.4.4 kernel for TQM850L
3447 Created: Wed Jul 19 02:34:59 2000
3448 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3449 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
3450 Load Address: 0x00000000
3451 Entry Point: 0x00000000
3453 To verify the contents of the image (or check for corruption):
3455 -> tools/mkimage -l examples/uImage.TQM850L
3456 Image Name: 2.4.4 kernel for TQM850L
3457 Created: Wed Jul 19 02:34:59 2000
3458 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3459 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
3460 Load Address: 0x00000000
3461 Entry Point: 0x00000000
3463 NOTE: for embedded systems where boot time is critical you can trade
3464 speed for memory and install an UNCOMPRESSED image instead: this
3465 needs more space in Flash, but boots much faster since it does not
3466 need to be uncompressed:
3468 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux.gz
3469 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
3470 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
3471 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux \
3472 > examples/uImage.TQM850L-uncompressed
3473 Image Name: 2.4.4 kernel for TQM850L
3474 Created: Wed Jul 19 02:34:59 2000
3475 Image Type: PowerPC Linux Kernel Image (uncompressed)
3476 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
3477 Load Address: 0x00000000
3478 Entry Point: 0x00000000
3481 Similar you can build U-Boot images from a 'ramdisk.image.gz' file
3482 when your kernel is intended to use an initial ramdisk:
3484 -> tools/mkimage -n 'Simple Ramdisk Image' \
3485 > -A ppc -O linux -T ramdisk -C gzip \
3486 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
3487 Image Name: Simple Ramdisk Image
3488 Created: Wed Jan 12 14:01:50 2000
3489 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
3490 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
3491 Load Address: 0x00000000
3492 Entry Point: 0x00000000
3495 Installing a Linux Image:
3496 -------------------------
3498 To downloading a U-Boot image over the serial (console) interface,
3499 you must convert the image to S-Record format:
3501 objcopy -I binary -O srec examples/image examples/image.srec
3503 The 'objcopy' does not understand the information in the U-Boot
3504 image header, so the resulting S-Record file will be relative to
3505 address 0x00000000. To load it to a given address, you need to
3506 specify the target address as 'offset' parameter with the 'loads'
3509 Example: install the image to address 0x40100000 (which on the
3510 TQM8xxL is in the first Flash bank):
3512 => erase 40100000 401FFFFF
3518 ## Ready for S-Record download ...
3519 ~>examples/image.srec
3520 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
3522 15989 15990 15991 15992
3523 [file transfer complete]
3525 ## Start Addr = 0x00000000
3528 You can check the success of the download using the 'iminfo' command;
3529 this includes a checksum verification so you can be sure no data
3530 corruption happened:
3534 ## Checking Image at 40100000 ...
3535 Image Name: 2.2.13 for initrd on TQM850L
3536 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3537 Data Size: 335725 Bytes = 327 kB = 0 MB
3538 Load Address: 00000000
3539 Entry Point: 0000000c
3540 Verifying Checksum ... OK
3546 The "bootm" command is used to boot an application that is stored in
3547 memory (RAM or Flash). In case of a Linux kernel image, the contents
3548 of the "bootargs" environment variable is passed to the kernel as
3549 parameters. You can check and modify this variable using the
3550 "printenv" and "setenv" commands:
3553 => printenv bootargs
3554 bootargs=root=/dev/ram
3556 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
3558 => printenv bootargs
3559 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
3562 ## Booting Linux kernel at 40020000 ...
3563 Image Name: 2.2.13 for NFS on TQM850L
3564 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3565 Data Size: 381681 Bytes = 372 kB = 0 MB
3566 Load Address: 00000000
3567 Entry Point: 0000000c
3568 Verifying Checksum ... OK
3569 Uncompressing Kernel Image ... OK
3570 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
3571 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
3572 time_init: decrementer frequency = 187500000/60
3573 Calibrating delay loop... 49.77 BogoMIPS
3574 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
3577 If you want to boot a Linux kernel with initial RAM disk, you pass
3578 the memory addresses of both the kernel and the initrd image (PPBCOOT
3579 format!) to the "bootm" command:
3581 => imi 40100000 40200000
3583 ## Checking Image at 40100000 ...
3584 Image Name: 2.2.13 for initrd on TQM850L
3585 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3586 Data Size: 335725 Bytes = 327 kB = 0 MB
3587 Load Address: 00000000
3588 Entry Point: 0000000c
3589 Verifying Checksum ... OK
3591 ## Checking Image at 40200000 ...
3592 Image Name: Simple Ramdisk Image
3593 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
3594 Data Size: 566530 Bytes = 553 kB = 0 MB
3595 Load Address: 00000000
3596 Entry Point: 00000000
3597 Verifying Checksum ... OK
3599 => bootm 40100000 40200000
3600 ## Booting Linux kernel at 40100000 ...
3601 Image Name: 2.2.13 for initrd on TQM850L
3602 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3603 Data Size: 335725 Bytes = 327 kB = 0 MB
3604 Load Address: 00000000
3605 Entry Point: 0000000c
3606 Verifying Checksum ... OK
3607 Uncompressing Kernel Image ... OK
3608 ## Loading RAMDisk Image at 40200000 ...
3609 Image Name: Simple Ramdisk Image
3610 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
3611 Data Size: 566530 Bytes = 553 kB = 0 MB
3612 Load Address: 00000000
3613 Entry Point: 00000000
3614 Verifying Checksum ... OK
3615 Loading Ramdisk ... OK
3616 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
3617 Boot arguments: root=/dev/ram
3618 time_init: decrementer frequency = 187500000/60
3619 Calibrating delay loop... 49.77 BogoMIPS
3621 RAMDISK: Compressed image found at block 0
3622 VFS: Mounted root (ext2 filesystem).
3626 Boot Linux and pass a flat device tree:
3629 First, U-Boot must be compiled with the appropriate defines. See the section
3630 titled "Linux Kernel Interface" above for a more in depth explanation. The
3631 following is an example of how to start a kernel and pass an updated
3637 oft=oftrees/mpc8540ads.dtb
3638 => tftp $oftaddr $oft
3639 Speed: 1000, full duplex
3641 TFTP from server 192.168.1.1; our IP address is 192.168.1.101
3642 Filename 'oftrees/mpc8540ads.dtb'.
3643 Load address: 0x300000
3646 Bytes transferred = 4106 (100a hex)
3647 => tftp $loadaddr $bootfile
3648 Speed: 1000, full duplex
3650 TFTP from server 192.168.1.1; our IP address is 192.168.1.2
3652 Load address: 0x200000
3653 Loading:############
3655 Bytes transferred = 1029407 (fb51f hex)
3660 => bootm $loadaddr - $oftaddr
3661 ## Booting image at 00200000 ...
3662 Image Name: Linux-2.6.17-dirty
3663 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3664 Data Size: 1029343 Bytes = 1005.2 kB
3665 Load Address: 00000000
3666 Entry Point: 00000000
3667 Verifying Checksum ... OK
3668 Uncompressing Kernel Image ... OK
3669 Booting using flat device tree at 0x300000
3670 Using MPC85xx ADS machine description
3671 Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb
3675 More About U-Boot Image Types:
3676 ------------------------------
3678 U-Boot supports the following image types:
3680 "Standalone Programs" are directly runnable in the environment
3681 provided by U-Boot; it is expected that (if they behave
3682 well) you can continue to work in U-Boot after return from
3683 the Standalone Program.
3684 "OS Kernel Images" are usually images of some Embedded OS which
3685 will take over control completely. Usually these programs
3686 will install their own set of exception handlers, device
3687 drivers, set up the MMU, etc. - this means, that you cannot
3688 expect to re-enter U-Boot except by resetting the CPU.
3689 "RAMDisk Images" are more or less just data blocks, and their
3690 parameters (address, size) are passed to an OS kernel that is
3692 "Multi-File Images" contain several images, typically an OS
3693 (Linux) kernel image and one or more data images like
3694 RAMDisks. This construct is useful for instance when you want
3695 to boot over the network using BOOTP etc., where the boot
3696 server provides just a single image file, but you want to get
3697 for instance an OS kernel and a RAMDisk image.
3699 "Multi-File Images" start with a list of image sizes, each
3700 image size (in bytes) specified by an "uint32_t" in network
3701 byte order. This list is terminated by an "(uint32_t)0".
3702 Immediately after the terminating 0 follow the images, one by
3703 one, all aligned on "uint32_t" boundaries (size rounded up to
3704 a multiple of 4 bytes).
3706 "Firmware Images" are binary images containing firmware (like
3707 U-Boot or FPGA images) which usually will be programmed to
3710 "Script files" are command sequences that will be executed by
3711 U-Boot's command interpreter; this feature is especially
3712 useful when you configure U-Boot to use a real shell (hush)
3713 as command interpreter.
3719 One of the features of U-Boot is that you can dynamically load and
3720 run "standalone" applications, which can use some resources of
3721 U-Boot like console I/O functions or interrupt services.
3723 Two simple examples are included with the sources:
3728 'examples/hello_world.c' contains a small "Hello World" Demo
3729 application; it is automatically compiled when you build U-Boot.
3730 It's configured to run at address 0x00040004, so you can play with it
3734 ## Ready for S-Record download ...
3735 ~>examples/hello_world.srec
3736 1 2 3 4 5 6 7 8 9 10 11 ...
3737 [file transfer complete]
3739 ## Start Addr = 0x00040004
3741 => go 40004 Hello World! This is a test.
3742 ## Starting application at 0x00040004 ...
3753 Hit any key to exit ...
3755 ## Application terminated, rc = 0x0
3757 Another example, which demonstrates how to register a CPM interrupt
3758 handler with the U-Boot code, can be found in 'examples/timer.c'.
3759 Here, a CPM timer is set up to generate an interrupt every second.
3760 The interrupt service routine is trivial, just printing a '.'
3761 character, but this is just a demo program. The application can be
3762 controlled by the following keys:
3764 ? - print current values og the CPM Timer registers
3765 b - enable interrupts and start timer
3766 e - stop timer and disable interrupts
3767 q - quit application
3770 ## Ready for S-Record download ...
3771 ~>examples/timer.srec
3772 1 2 3 4 5 6 7 8 9 10 11 ...
3773 [file transfer complete]
3775 ## Start Addr = 0x00040004
3778 ## Starting application at 0x00040004 ...
3781 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
3784 [q, b, e, ?] Set interval 1000000 us
3787 [q, b, e, ?] ........
3788 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
3791 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
3794 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
3797 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
3799 [q, b, e, ?] ...Stopping timer
3801 [q, b, e, ?] ## Application terminated, rc = 0x0
3807 Over time, many people have reported problems when trying to use the
3808 "minicom" terminal emulation program for serial download. I (wd)
3809 consider minicom to be broken, and recommend not to use it. Under
3810 Unix, I recommend to use C-Kermit for general purpose use (and
3811 especially for kermit binary protocol download ("loadb" command), and
3812 use "cu" for S-Record download ("loads" command).
3814 Nevertheless, if you absolutely want to use it try adding this
3815 configuration to your "File transfer protocols" section:
3817 Name Program Name U/D FullScr IO-Red. Multi
3818 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
3819 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
3825 Starting at version 0.9.2, U-Boot supports NetBSD both as host
3826 (build U-Boot) and target system (boots NetBSD/mpc8xx).
3828 Building requires a cross environment; it is known to work on
3829 NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
3830 need gmake since the Makefiles are not compatible with BSD make).
3831 Note that the cross-powerpc package does not install include files;
3832 attempting to build U-Boot will fail because <machine/ansi.h> is
3833 missing. This file has to be installed and patched manually:
3835 # cd /usr/pkg/cross/powerpc-netbsd/include
3837 # ln -s powerpc machine
3838 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
3839 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
3841 Native builds *don't* work due to incompatibilities between native
3842 and U-Boot include files.
3844 Booting assumes that (the first part of) the image booted is a
3845 stage-2 loader which in turn loads and then invokes the kernel
3846 proper. Loader sources will eventually appear in the NetBSD source
3847 tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
3848 meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz
3851 Implementation Internals:
3852 =========================
3854 The following is not intended to be a complete description of every
3855 implementation detail. However, it should help to understand the
3856 inner workings of U-Boot and make it easier to port it to custom
3860 Initial Stack, Global Data:
3861 ---------------------------
3863 The implementation of U-Boot is complicated by the fact that U-Boot
3864 starts running out of ROM (flash memory), usually without access to
3865 system RAM (because the memory controller is not initialized yet).
3866 This means that we don't have writable Data or BSS segments, and BSS
3867 is not initialized as zero. To be able to get a C environment working
3868 at all, we have to allocate at least a minimal stack. Implementation
3869 options for this are defined and restricted by the CPU used: Some CPU
3870 models provide on-chip memory (like the IMMR area on MPC8xx and
3871 MPC826x processors), on others (parts of) the data cache can be
3872 locked as (mis-) used as memory, etc.
3874 Chris Hallinan posted a good summary of these issues to the
3875 U-Boot mailing list:
3877 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
3878 From: "Chris Hallinan" <clh@net1plus.com>
3879 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
3882 Correct me if I'm wrong, folks, but the way I understand it
3883 is this: Using DCACHE as initial RAM for Stack, etc, does not
3884 require any physical RAM backing up the cache. The cleverness
3885 is that the cache is being used as a temporary supply of
3886 necessary storage before the SDRAM controller is setup. It's
3887 beyond the scope of this list to explain the details, but you
3888 can see how this works by studying the cache architecture and
3889 operation in the architecture and processor-specific manuals.
3891 OCM is On Chip Memory, which I believe the 405GP has 4K. It
3892 is another option for the system designer to use as an
3893 initial stack/RAM area prior to SDRAM being available. Either
3894 option should work for you. Using CS 4 should be fine if your
3895 board designers haven't used it for something that would
3896 cause you grief during the initial boot! It is frequently not
3899 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere
3900 with your processor/board/system design. The default value
3901 you will find in any recent u-boot distribution in
3902 walnut.h should work for you. I'd set it to a value larger
3903 than your SDRAM module. If you have a 64MB SDRAM module, set
3904 it above 400_0000. Just make sure your board has no resources
3905 that are supposed to respond to that address! That code in
3906 start.S has been around a while and should work as is when
3907 you get the config right.
3912 It is essential to remember this, since it has some impact on the C
3913 code for the initialization procedures:
3915 * Initialized global data (data segment) is read-only. Do not attempt
3918 * Do not use any uninitialized global data (or implicitely initialized
3919 as zero data - BSS segment) at all - this is undefined, initiali-
3920 zation is performed later (when relocating to RAM).
3922 * Stack space is very limited. Avoid big data buffers or things like
3925 Having only the stack as writable memory limits means we cannot use
3926 normal global data to share information beween the code. But it
3927 turned out that the implementation of U-Boot can be greatly
3928 simplified by making a global data structure (gd_t) available to all
3929 functions. We could pass a pointer to this data as argument to _all_
3930 functions, but this would bloat the code. Instead we use a feature of
3931 the GCC compiler (Global Register Variables) to share the data: we
3932 place a pointer (gd) to the global data into a register which we
3933 reserve for this purpose.
3935 When choosing a register for such a purpose we are restricted by the
3936 relevant (E)ABI specifications for the current architecture, and by
3937 GCC's implementation.
3939 For PowerPC, the following registers have specific use:
3941 R2: reserved for system use
3942 R3-R4: parameter passing and return values
3943 R5-R10: parameter passing
3944 R13: small data area pointer
3948 (U-Boot also uses R12 as internal GOT pointer. r12
3949 is a volatile register so r12 needs to be reset when
3950 going back and forth between asm and C)
3952 ==> U-Boot will use R2 to hold a pointer to the global data
3954 Note: on PPC, we could use a static initializer (since the
3955 address of the global data structure is known at compile time),
3956 but it turned out that reserving a register results in somewhat
3957 smaller code - although the code savings are not that big (on
3958 average for all boards 752 bytes for the whole U-Boot image,
3959 624 text + 127 data).
3961 On Blackfin, the normal C ABI (except for P3) is followed as documented here:
3962 http://docs.blackfin.uclinux.org/doku.php?id=application_binary_interface
3964 ==> U-Boot will use P3 to hold a pointer to the global data
3966 On ARM, the following registers are used:
3968 R0: function argument word/integer result
3969 R1-R3: function argument word
3971 R10: stack limit (used only if stack checking if enabled)
3972 R11: argument (frame) pointer
3973 R12: temporary workspace
3976 R15: program counter
3978 ==> U-Boot will use R8 to hold a pointer to the global data
3980 NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope,
3981 or current versions of GCC may "optimize" the code too much.
3986 U-Boot runs in system state and uses physical addresses, i.e. the
3987 MMU is not used either for address mapping nor for memory protection.
3989 The available memory is mapped to fixed addresses using the memory
3990 controller. In this process, a contiguous block is formed for each
3991 memory type (Flash, SDRAM, SRAM), even when it consists of several
3992 physical memory banks.
3994 U-Boot is installed in the first 128 kB of the first Flash bank (on
3995 TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
3996 booting and sizing and initializing DRAM, the code relocates itself
3997 to the upper end of DRAM. Immediately below the U-Boot code some
3998 memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN
3999 configuration setting]. Below that, a structure with global Board
4000 Info data is placed, followed by the stack (growing downward).
4002 Additionally, some exception handler code is copied to the low 8 kB
4003 of DRAM (0x00000000 ... 0x00001FFF).
4005 So a typical memory configuration with 16 MB of DRAM could look like
4008 0x0000 0000 Exception Vector code
4011 0x0000 2000 Free for Application Use
4017 0x00FB FF20 Monitor Stack (Growing downward)
4018 0x00FB FFAC Board Info Data and permanent copy of global data
4019 0x00FC 0000 Malloc Arena
4022 0x00FE 0000 RAM Copy of Monitor Code
4023 ... eventually: LCD or video framebuffer
4024 ... eventually: pRAM (Protected RAM - unchanged by reset)
4025 0x00FF FFFF [End of RAM]
4028 System Initialization:
4029 ----------------------
4031 In the reset configuration, U-Boot starts at the reset entry point
4032 (on most PowerPC systems at address 0x00000100). Because of the reset
4033 configuration for CS0# this is a mirror of the onboard Flash memory.
4034 To be able to re-map memory U-Boot then jumps to its link address.
4035 To be able to implement the initialization code in C, a (small!)
4036 initial stack is set up in the internal Dual Ported RAM (in case CPUs
4037 which provide such a feature like MPC8xx or MPC8260), or in a locked
4038 part of the data cache. After that, U-Boot initializes the CPU core,
4039 the caches and the SIU.
4041 Next, all (potentially) available memory banks are mapped using a
4042 preliminary mapping. For example, we put them on 512 MB boundaries
4043 (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
4044 on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
4045 programmed for SDRAM access. Using the temporary configuration, a
4046 simple memory test is run that determines the size of the SDRAM
4049 When there is more than one SDRAM bank, and the banks are of
4050 different size, the largest is mapped first. For equal size, the first
4051 bank (CS2#) is mapped first. The first mapping is always for address
4052 0x00000000, with any additional banks following immediately to create
4053 contiguous memory starting from 0.
4055 Then, the monitor installs itself at the upper end of the SDRAM area
4056 and allocates memory for use by malloc() and for the global Board
4057 Info data; also, the exception vector code is copied to the low RAM
4058 pages, and the final stack is set up.
4060 Only after this relocation will you have a "normal" C environment;
4061 until that you are restricted in several ways, mostly because you are
4062 running from ROM, and because the code will have to be relocated to a
4066 U-Boot Porting Guide:
4067 ----------------------
4069 [Based on messages by Jerry Van Baren in the U-Boot-Users mailing
4073 int main(int argc, char *argv[])
4075 sighandler_t no_more_time;
4077 signal(SIGALRM, no_more_time);
4078 alarm(PROJECT_DEADLINE - toSec (3 * WEEK));
4080 if (available_money > available_manpower) {
4081 Pay consultant to port U-Boot;
4085 Download latest U-Boot source;
4087 Subscribe to u-boot mailing list;
4090 email("Hi, I am new to U-Boot, how do I get started?");
4093 Read the README file in the top level directory;
4094 Read http://www.denx.de/twiki/bin/view/DULG/Manual;
4095 Read applicable doc/*.README;
4096 Read the source, Luke;
4097 /* find . -name "*.[chS]" | xargs grep -i <keyword> */
4100 if (available_money > toLocalCurrency ($2500))
4103 Add a lot of aggravation and time;
4105 if (a similar board exists) { /* hopefully... */
4106 cp -a board/<similar> board/<myboard>
4107 cp include/configs/<similar>.h include/configs/<myboard>.h
4109 Create your own board support subdirectory;
4110 Create your own board include/configs/<myboard>.h file;
4112 Edit new board/<myboard> files
4113 Edit new include/configs/<myboard>.h
4118 Add / modify source code;
4122 email("Hi, I am having problems...");
4124 Send patch file to the U-Boot email list;
4125 if (reasonable critiques)
4126 Incorporate improvements from email list code review;
4128 Defend code as written;
4134 void no_more_time (int sig)
4143 All contributions to U-Boot should conform to the Linux kernel
4144 coding style; see the file "Documentation/CodingStyle" and the script
4145 "scripts/Lindent" in your Linux kernel source directory. In sources
4146 originating from U-Boot a style corresponding to "Lindent -pcs" (adding
4147 spaces before parameters to function calls) is actually used.
4149 Source files originating from a different project (for example the
4150 MTD subsystem) are generally exempt from these guidelines and are not
4151 reformated to ease subsequent migration to newer versions of those
4154 Please note that U-Boot is implemented in C (and to some small parts in
4155 Assembler); no C++ is used, so please do not use C++ style comments (//)
4158 Please also stick to the following formatting rules:
4159 - remove any trailing white space
4160 - use TAB characters for indentation, not spaces
4161 - make sure NOT to use DOS '\r\n' line feeds
4162 - do not add more than 2 empty lines to source files
4163 - do not add trailing empty lines to source files
4165 Submissions which do not conform to the standards may be returned
4166 with a request to reformat the changes.
4172 Since the number of patches for U-Boot is growing, we need to
4173 establish some rules. Submissions which do not conform to these rules
4174 may be rejected, even when they contain important and valuable stuff.
4176 Please see http://www.denx.de/wiki/U-Boot/Patches for details.
4178 Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>;
4179 see http://lists.denx.de/mailman/listinfo/u-boot
4181 When you send a patch, please include the following information with
4184 * For bug fixes: a description of the bug and how your patch fixes
4185 this bug. Please try to include a way of demonstrating that the
4186 patch actually fixes something.
4188 * For new features: a description of the feature and your
4191 * A CHANGELOG entry as plaintext (separate from the patch)
4193 * For major contributions, your entry to the CREDITS file
4195 * When you add support for a new board, don't forget to add this
4196 board to the MAKEALL script, too.
4198 * If your patch adds new configuration options, don't forget to
4199 document these in the README file.
4201 * The patch itself. If you are using git (which is *strongly*
4202 recommended) you can easily generate the patch using the
4203 "git-format-patch". If you then use "git-send-email" to send it to
4204 the U-Boot mailing list, you will avoid most of the common problems
4205 with some other mail clients.
4207 If you cannot use git, use "diff -purN OLD NEW". If your version of
4208 diff does not support these options, then get the latest version of
4211 The current directory when running this command shall be the parent
4212 directory of the U-Boot source tree (i. e. please make sure that
4213 your patch includes sufficient directory information for the
4216 We prefer patches as plain text. MIME attachments are discouraged,
4217 and compressed attachments must not be used.
4219 * If one logical set of modifications affects or creates several
4220 files, all these changes shall be submitted in a SINGLE patch file.
4222 * Changesets that contain different, unrelated modifications shall be
4223 submitted as SEPARATE patches, one patch per changeset.
4228 * Before sending the patch, run the MAKEALL script on your patched
4229 source tree and make sure that no errors or warnings are reported
4230 for any of the boards.
4232 * Keep your modifications to the necessary minimum: A patch
4233 containing several unrelated changes or arbitrary reformats will be
4234 returned with a request to re-formatting / split it.
4236 * If you modify existing code, make sure that your new code does not
4237 add to the memory footprint of the code ;-) Small is beautiful!
4238 When adding new features, these should compile conditionally only
4239 (using #ifdef), and the resulting code with the new feature
4240 disabled must not need more memory than the old code without your
4243 * Remember that there is a size limit of 100 kB per message on the
4244 u-boot mailing list. Bigger patches will be moderated. If they are
4245 reasonable and not too big, they will be acknowledged. But patches
4246 bigger than the size limit should be avoided.
projects / u-boot / blob