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 - arch/arm/lib Files generic to ARM architecture
186 - arch/avr32/lib Files generic to AVR32 architecture
187 - arch/blackfin/lib Files generic to Blackfin architecture
188 - lib Files generic to all architectures
189 - arch/i386/lib Files generic to i386 architecture
190 - arch/m68k/lib Files generic to m68k architecture
191 - arch/microblaze/lib Files generic to microblaze architecture
192 - arch/mips/lib Files generic to MIPS architecture
193 - arch/nios/lib Files generic to NIOS architecture
194 - arch/nios/lib2 Files generic to NIOS2 architecture
195 - arch/ppc/lib Files generic to PowerPC architecture
196 - arch/sh/lib Files generic to SH architecture
197 - arch/sparc/lib 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 - Run length encoded BMP image (RLE8) support: CONFIG_VIDEO_BMP_RLE8
1138 If this option is set, 8-bit RLE compressed BMP images
1139 can be displayed via the splashscreen support or the
1142 - Compression support:
1145 If this option is set, support for bzip2 compressed
1146 images is included. If not, only uncompressed and gzip
1147 compressed images are supported.
1149 NOTE: the bzip2 algorithm requires a lot of RAM, so
1150 the malloc area (as defined by CONFIG_SYS_MALLOC_LEN) should
1155 If this option is set, support for lzma compressed
1158 Note: The LZMA algorithm adds between 2 and 4KB of code and it
1159 requires an amount of dynamic memory that is given by the
1162 (1846 + 768 << (lc + lp)) * sizeof(uint16)
1164 Where lc and lp stand for, respectively, Literal context bits
1165 and Literal pos bits.
1167 This value is upper-bounded by 14MB in the worst case. Anyway,
1168 for a ~4MB large kernel image, we have lc=3 and lp=0 for a
1169 total amount of (1846 + 768 << (3 + 0)) * 2 = ~41KB... that is
1170 a very small buffer.
1172 Use the lzmainfo tool to determinate the lc and lp values and
1173 then calculate the amount of needed dynamic memory (ensuring
1174 the appropriate CONFIG_SYS_MALLOC_LEN value).
1179 The address of PHY on MII bus.
1181 CONFIG_PHY_CLOCK_FREQ (ppc4xx)
1183 The clock frequency of the MII bus
1187 If this option is set, support for speed/duplex
1188 detection of gigabit PHY is included.
1190 CONFIG_PHY_RESET_DELAY
1192 Some PHY like Intel LXT971A need extra delay after
1193 reset before any MII register access is possible.
1194 For such PHY, set this option to the usec delay
1195 required. (minimum 300usec for LXT971A)
1197 CONFIG_PHY_CMD_DELAY (ppc4xx)
1199 Some PHY like Intel LXT971A need extra delay after
1200 command issued before MII status register can be read
1210 Define a default value for Ethernet address to use
1211 for the respective Ethernet interface, in case this
1212 is not determined automatically.
1217 Define a default value for the IP address to use for
1218 the default Ethernet interface, in case this is not
1219 determined through e.g. bootp.
1221 - Server IP address:
1224 Defines a default value for the IP address of a TFTP
1225 server to contact when using the "tftboot" command.
1227 CONFIG_KEEP_SERVERADDR
1229 Keeps the server's MAC address, in the env 'serveraddr'
1230 for passing to bootargs (like Linux's netconsole option)
1232 - Multicast TFTP Mode:
1235 Defines whether you want to support multicast TFTP as per
1236 rfc-2090; for example to work with atftp. Lets lots of targets
1237 tftp down the same boot image concurrently. Note: the Ethernet
1238 driver in use must provide a function: mcast() to join/leave a
1241 CONFIG_BOOTP_RANDOM_DELAY
1242 - BOOTP Recovery Mode:
1243 CONFIG_BOOTP_RANDOM_DELAY
1245 If you have many targets in a network that try to
1246 boot using BOOTP, you may want to avoid that all
1247 systems send out BOOTP requests at precisely the same
1248 moment (which would happen for instance at recovery
1249 from a power failure, when all systems will try to
1250 boot, thus flooding the BOOTP server. Defining
1251 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
1252 inserted before sending out BOOTP requests. The
1253 following delays are inserted then:
1255 1st BOOTP request: delay 0 ... 1 sec
1256 2nd BOOTP request: delay 0 ... 2 sec
1257 3rd BOOTP request: delay 0 ... 4 sec
1259 BOOTP requests: delay 0 ... 8 sec
1261 - DHCP Advanced Options:
1262 You can fine tune the DHCP functionality by defining
1263 CONFIG_BOOTP_* symbols:
1265 CONFIG_BOOTP_SUBNETMASK
1266 CONFIG_BOOTP_GATEWAY
1267 CONFIG_BOOTP_HOSTNAME
1268 CONFIG_BOOTP_NISDOMAIN
1269 CONFIG_BOOTP_BOOTPATH
1270 CONFIG_BOOTP_BOOTFILESIZE
1273 CONFIG_BOOTP_SEND_HOSTNAME
1274 CONFIG_BOOTP_NTPSERVER
1275 CONFIG_BOOTP_TIMEOFFSET
1276 CONFIG_BOOTP_VENDOREX
1278 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip
1279 environment variable, not the BOOTP server.
1281 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS
1282 serverip from a DHCP server, it is possible that more
1283 than one DNS serverip is offered to the client.
1284 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS
1285 serverip will be stored in the additional environment
1286 variable "dnsip2". The first DNS serverip is always
1287 stored in the variable "dnsip", when CONFIG_BOOTP_DNS
1290 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable
1291 to do a dynamic update of a DNS server. To do this, they
1292 need the hostname of the DHCP requester.
1293 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content
1294 of the "hostname" environment variable is passed as
1295 option 12 to the DHCP server.
1297 CONFIG_BOOTP_DHCP_REQUEST_DELAY
1299 A 32bit value in microseconds for a delay between
1300 receiving a "DHCP Offer" and sending the "DHCP Request".
1301 This fixes a problem with certain DHCP servers that don't
1302 respond 100% of the time to a "DHCP request". E.g. On an
1303 AT91RM9200 processor running at 180MHz, this delay needed
1304 to be *at least* 15,000 usec before a Windows Server 2003
1305 DHCP server would reply 100% of the time. I recommend at
1306 least 50,000 usec to be safe. The alternative is to hope
1307 that one of the retries will be successful but note that
1308 the DHCP timeout and retry process takes a longer than
1312 CONFIG_CDP_DEVICE_ID
1314 The device id used in CDP trigger frames.
1316 CONFIG_CDP_DEVICE_ID_PREFIX
1318 A two character string which is prefixed to the MAC address
1323 A printf format string which contains the ascii name of
1324 the port. Normally is set to "eth%d" which sets
1325 eth0 for the first Ethernet, eth1 for the second etc.
1327 CONFIG_CDP_CAPABILITIES
1329 A 32bit integer which indicates the device capabilities;
1330 0x00000010 for a normal host which does not forwards.
1334 An ascii string containing the version of the software.
1338 An ascii string containing the name of the platform.
1342 A 32bit integer sent on the trigger.
1344 CONFIG_CDP_POWER_CONSUMPTION
1346 A 16bit integer containing the power consumption of the
1347 device in .1 of milliwatts.
1349 CONFIG_CDP_APPLIANCE_VLAN_TYPE
1351 A byte containing the id of the VLAN.
1353 - Status LED: CONFIG_STATUS_LED
1355 Several configurations allow to display the current
1356 status using a LED. For instance, the LED will blink
1357 fast while running U-Boot code, stop blinking as
1358 soon as a reply to a BOOTP request was received, and
1359 start blinking slow once the Linux kernel is running
1360 (supported by a status LED driver in the Linux
1361 kernel). Defining CONFIG_STATUS_LED enables this
1364 - CAN Support: CONFIG_CAN_DRIVER
1366 Defining CONFIG_CAN_DRIVER enables CAN driver support
1367 on those systems that support this (optional)
1368 feature, like the TQM8xxL modules.
1370 - I2C Support: CONFIG_HARD_I2C | CONFIG_SOFT_I2C
1372 These enable I2C serial bus commands. Defining either of
1373 (but not both of) CONFIG_HARD_I2C or CONFIG_SOFT_I2C will
1374 include the appropriate I2C driver for the selected CPU.
1376 This will allow you to use i2c commands at the u-boot
1377 command line (as long as you set CONFIG_CMD_I2C in
1378 CONFIG_COMMANDS) and communicate with i2c based realtime
1379 clock chips. See common/cmd_i2c.c for a description of the
1380 command line interface.
1382 CONFIG_HARD_I2C selects a hardware I2C controller.
1384 CONFIG_SOFT_I2C configures u-boot to use a software (aka
1385 bit-banging) driver instead of CPM or similar hardware
1388 There are several other quantities that must also be
1389 defined when you define CONFIG_HARD_I2C or CONFIG_SOFT_I2C.
1391 In both cases you will need to define CONFIG_SYS_I2C_SPEED
1392 to be the frequency (in Hz) at which you wish your i2c bus
1393 to run and CONFIG_SYS_I2C_SLAVE to be the address of this node (ie
1394 the CPU's i2c node address).
1396 Now, the u-boot i2c code for the mpc8xx (cpu/mpc8xx/i2c.c)
1397 sets the CPU up as a master node and so its address should
1398 therefore be cleared to 0 (See, eg, MPC823e User's Manual
1399 p.16-473). So, set CONFIG_SYS_I2C_SLAVE to 0.
1401 CONFIG_SYS_I2C_INIT_MPC5XXX
1403 When a board is reset during an i2c bus transfer
1404 chips might think that the current transfer is still
1405 in progress. Reset the slave devices by sending start
1406 commands until the slave device responds.
1408 That's all that's required for CONFIG_HARD_I2C.
1410 If you use the software i2c interface (CONFIG_SOFT_I2C)
1411 then the following macros need to be defined (examples are
1412 from include/configs/lwmon.h):
1416 (Optional). Any commands necessary to enable the I2C
1417 controller or configure ports.
1419 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
1423 (Only for MPC8260 CPU). The I/O port to use (the code
1424 assumes both bits are on the same port). Valid values
1425 are 0..3 for ports A..D.
1429 The code necessary to make the I2C data line active
1430 (driven). If the data line is open collector, this
1433 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
1437 The code necessary to make the I2C data line tri-stated
1438 (inactive). If the data line is open collector, this
1441 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
1445 Code that returns TRUE if the I2C data line is high,
1448 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
1452 If <bit> is TRUE, sets the I2C data line high. If it
1453 is FALSE, it clears it (low).
1455 eg: #define I2C_SDA(bit) \
1456 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
1457 else immr->im_cpm.cp_pbdat &= ~PB_SDA
1461 If <bit> is TRUE, sets the I2C clock line high. If it
1462 is FALSE, it clears it (low).
1464 eg: #define I2C_SCL(bit) \
1465 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
1466 else immr->im_cpm.cp_pbdat &= ~PB_SCL
1470 This delay is invoked four times per clock cycle so this
1471 controls the rate of data transfer. The data rate thus
1472 is 1 / (I2C_DELAY * 4). Often defined to be something
1475 #define I2C_DELAY udelay(2)
1477 CONFIG_SYS_I2C_INIT_BOARD
1479 When a board is reset during an i2c bus transfer
1480 chips might think that the current transfer is still
1481 in progress. On some boards it is possible to access
1482 the i2c SCLK line directly, either by using the
1483 processor pin as a GPIO or by having a second pin
1484 connected to the bus. If this option is defined a
1485 custom i2c_init_board() routine in boards/xxx/board.c
1486 is run early in the boot sequence.
1488 CONFIG_I2CFAST (PPC405GP|PPC405EP only)
1490 This option enables configuration of bi_iic_fast[] flags
1491 in u-boot bd_info structure based on u-boot environment
1492 variable "i2cfast". (see also i2cfast)
1494 CONFIG_I2C_MULTI_BUS
1496 This option allows the use of multiple I2C buses, each of which
1497 must have a controller. At any point in time, only one bus is
1498 active. To switch to a different bus, use the 'i2c dev' command.
1499 Note that bus numbering is zero-based.
1501 CONFIG_SYS_I2C_NOPROBES
1503 This option specifies a list of I2C devices that will be skipped
1504 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS
1505 is set, specify a list of bus-device pairs. Otherwise, specify
1506 a 1D array of device addresses
1509 #undef CONFIG_I2C_MULTI_BUS
1510 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68}
1512 will skip addresses 0x50 and 0x68 on a board with one I2C bus
1514 #define CONFIG_I2C_MULTI_BUS
1515 #define CONFIG_SYS_I2C_MULTI_NOPROBES {{0,0x50},{0,0x68},{1,0x54}}
1517 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1
1519 CONFIG_SYS_SPD_BUS_NUM
1521 If defined, then this indicates the I2C bus number for DDR SPD.
1522 If not defined, then U-Boot assumes that SPD is on I2C bus 0.
1524 CONFIG_SYS_RTC_BUS_NUM
1526 If defined, then this indicates the I2C bus number for the RTC.
1527 If not defined, then U-Boot assumes that RTC is on I2C bus 0.
1529 CONFIG_SYS_DTT_BUS_NUM
1531 If defined, then this indicates the I2C bus number for the DTT.
1532 If not defined, then U-Boot assumes that DTT is on I2C bus 0.
1534 CONFIG_SYS_I2C_DTT_ADDR:
1536 If defined, specifies the I2C address of the DTT device.
1537 If not defined, then U-Boot uses predefined value for
1538 specified DTT device.
1542 Define this option if you want to use Freescale's I2C driver in
1543 drivers/i2c/fsl_i2c.c.
1547 Define this option if you have I2C devices reached over 1 .. n
1548 I2C Muxes like the pca9544a. This option addes a new I2C
1549 Command "i2c bus [muxtype:muxaddr:muxchannel]" which adds a
1550 new I2C Bus to the existing I2C Busses. If you select the
1551 new Bus with "i2c dev", u-bbot sends first the commandos for
1552 the muxes to activate this new "bus".
1554 CONFIG_I2C_MULTI_BUS must be also defined, to use this
1558 Adding a new I2C Bus reached over 2 pca9544a muxes
1559 The First mux with address 70 and channel 6
1560 The Second mux with address 71 and channel 4
1562 => i2c bus pca9544a:70:6:pca9544a:71:4
1564 Use the "i2c bus" command without parameter, to get a list
1565 of I2C Busses with muxes:
1568 Busses reached over muxes:
1570 reached over Mux(es):
1573 reached over Mux(es):
1578 If you now switch to the new I2C Bus 3 with "i2c dev 3"
1579 u-boot sends First the Commando to the mux@70 to enable
1580 channel 6, and then the Commando to the mux@71 to enable
1583 After that, you can use the "normal" i2c commands as
1584 usual, to communicate with your I2C devices behind
1587 This option is actually implemented for the bitbanging
1588 algorithm in common/soft_i2c.c and for the Hardware I2C
1589 Bus on the MPC8260. But it should be not so difficult
1590 to add this option to other architectures.
1592 CONFIG_SOFT_I2C_READ_REPEATED_START
1594 defining this will force the i2c_read() function in
1595 the soft_i2c driver to perform an I2C repeated start
1596 between writing the address pointer and reading the
1597 data. If this define is omitted the default behaviour
1598 of doing a stop-start sequence will be used. Most I2C
1599 devices can use either method, but some require one or
1602 - SPI Support: CONFIG_SPI
1604 Enables SPI driver (so far only tested with
1605 SPI EEPROM, also an instance works with Crystal A/D and
1606 D/As on the SACSng board)
1610 Enables extended (16-bit) SPI EEPROM addressing.
1611 (symmetrical to CONFIG_I2C_X)
1615 Enables a software (bit-bang) SPI driver rather than
1616 using hardware support. This is a general purpose
1617 driver that only requires three general I/O port pins
1618 (two outputs, one input) to function. If this is
1619 defined, the board configuration must define several
1620 SPI configuration items (port pins to use, etc). For
1621 an example, see include/configs/sacsng.h.
1625 Enables a hardware SPI driver for general-purpose reads
1626 and writes. As with CONFIG_SOFT_SPI, the board configuration
1627 must define a list of chip-select function pointers.
1628 Currently supported on some MPC8xxx processors. For an
1629 example, see include/configs/mpc8349emds.h.
1633 Enables the driver for the SPI controllers on i.MX and MXC
1634 SoCs. Currently only i.MX31 is supported.
1636 - FPGA Support: CONFIG_FPGA
1638 Enables FPGA subsystem.
1640 CONFIG_FPGA_<vendor>
1642 Enables support for specific chip vendors.
1645 CONFIG_FPGA_<family>
1647 Enables support for FPGA family.
1648 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX)
1652 Specify the number of FPGA devices to support.
1654 CONFIG_SYS_FPGA_PROG_FEEDBACK
1656 Enable printing of hash marks during FPGA configuration.
1658 CONFIG_SYS_FPGA_CHECK_BUSY
1660 Enable checks on FPGA configuration interface busy
1661 status by the configuration function. This option
1662 will require a board or device specific function to
1667 If defined, a function that provides delays in the FPGA
1668 configuration driver.
1670 CONFIG_SYS_FPGA_CHECK_CTRLC
1671 Allow Control-C to interrupt FPGA configuration
1673 CONFIG_SYS_FPGA_CHECK_ERROR
1675 Check for configuration errors during FPGA bitfile
1676 loading. For example, abort during Virtex II
1677 configuration if the INIT_B line goes low (which
1678 indicated a CRC error).
1680 CONFIG_SYS_FPGA_WAIT_INIT
1682 Maximum time to wait for the INIT_B line to deassert
1683 after PROB_B has been deasserted during a Virtex II
1684 FPGA configuration sequence. The default time is 500
1687 CONFIG_SYS_FPGA_WAIT_BUSY
1689 Maximum time to wait for BUSY to deassert during
1690 Virtex II FPGA configuration. The default is 5 ms.
1692 CONFIG_SYS_FPGA_WAIT_CONFIG
1694 Time to wait after FPGA configuration. The default is
1697 - Configuration Management:
1700 If defined, this string will be added to the U-Boot
1701 version information (U_BOOT_VERSION)
1703 - Vendor Parameter Protection:
1705 U-Boot considers the values of the environment
1706 variables "serial#" (Board Serial Number) and
1707 "ethaddr" (Ethernet Address) to be parameters that
1708 are set once by the board vendor / manufacturer, and
1709 protects these variables from casual modification by
1710 the user. Once set, these variables are read-only,
1711 and write or delete attempts are rejected. You can
1712 change this behaviour:
1714 If CONFIG_ENV_OVERWRITE is #defined in your config
1715 file, the write protection for vendor parameters is
1716 completely disabled. Anybody can change or delete
1719 Alternatively, if you #define _both_ CONFIG_ETHADDR
1720 _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
1721 Ethernet address is installed in the environment,
1722 which can be changed exactly ONCE by the user. [The
1723 serial# is unaffected by this, i. e. it remains
1729 Define this variable to enable the reservation of
1730 "protected RAM", i. e. RAM which is not overwritten
1731 by U-Boot. Define CONFIG_PRAM to hold the number of
1732 kB you want to reserve for pRAM. You can overwrite
1733 this default value by defining an environment
1734 variable "pram" to the number of kB you want to
1735 reserve. Note that the board info structure will
1736 still show the full amount of RAM. If pRAM is
1737 reserved, a new environment variable "mem" will
1738 automatically be defined to hold the amount of
1739 remaining RAM in a form that can be passed as boot
1740 argument to Linux, for instance like that:
1742 setenv bootargs ... mem=\${mem}
1745 This way you can tell Linux not to use this memory,
1746 either, which results in a memory region that will
1747 not be affected by reboots.
1749 *WARNING* If your board configuration uses automatic
1750 detection of the RAM size, you must make sure that
1751 this memory test is non-destructive. So far, the
1752 following board configurations are known to be
1755 ETX094, IVMS8, IVML24, SPD8xx, TQM8xxL,
1756 HERMES, IP860, RPXlite, LWMON, LANTEC,
1757 PCU_E, FLAGADM, TQM8260
1762 Define this variable to stop the system in case of a
1763 fatal error, so that you have to reset it manually.
1764 This is probably NOT a good idea for an embedded
1765 system where you want the system to reboot
1766 automatically as fast as possible, but it may be
1767 useful during development since you can try to debug
1768 the conditions that lead to the situation.
1770 CONFIG_NET_RETRY_COUNT
1772 This variable defines the number of retries for
1773 network operations like ARP, RARP, TFTP, or BOOTP
1774 before giving up the operation. If not defined, a
1775 default value of 5 is used.
1779 Timeout waiting for an ARP reply in milliseconds.
1781 - Command Interpreter:
1782 CONFIG_AUTO_COMPLETE
1784 Enable auto completion of commands using TAB.
1786 Note that this feature has NOT been implemented yet
1787 for the "hush" shell.
1790 CONFIG_SYS_HUSH_PARSER
1792 Define this variable to enable the "hush" shell (from
1793 Busybox) as command line interpreter, thus enabling
1794 powerful command line syntax like
1795 if...then...else...fi conditionals or `&&' and '||'
1796 constructs ("shell scripts").
1798 If undefined, you get the old, much simpler behaviour
1799 with a somewhat smaller memory footprint.
1802 CONFIG_SYS_PROMPT_HUSH_PS2
1804 This defines the secondary prompt string, which is
1805 printed when the command interpreter needs more input
1806 to complete a command. Usually "> ".
1810 In the current implementation, the local variables
1811 space and global environment variables space are
1812 separated. Local variables are those you define by
1813 simply typing `name=value'. To access a local
1814 variable later on, you have write `$name' or
1815 `${name}'; to execute the contents of a variable
1816 directly type `$name' at the command prompt.
1818 Global environment variables are those you use
1819 setenv/printenv to work with. To run a command stored
1820 in such a variable, you need to use the run command,
1821 and you must not use the '$' sign to access them.
1823 To store commands and special characters in a
1824 variable, please use double quotation marks
1825 surrounding the whole text of the variable, instead
1826 of the backslashes before semicolons and special
1829 - Commandline Editing and History:
1830 CONFIG_CMDLINE_EDITING
1832 Enable editing and History functions for interactive
1833 commandline input operations
1835 - Default Environment:
1836 CONFIG_EXTRA_ENV_SETTINGS
1838 Define this to contain any number of null terminated
1839 strings (variable = value pairs) that will be part of
1840 the default environment compiled into the boot image.
1842 For example, place something like this in your
1843 board's config file:
1845 #define CONFIG_EXTRA_ENV_SETTINGS \
1849 Warning: This method is based on knowledge about the
1850 internal format how the environment is stored by the
1851 U-Boot code. This is NOT an official, exported
1852 interface! Although it is unlikely that this format
1853 will change soon, there is no guarantee either.
1854 You better know what you are doing here.
1856 Note: overly (ab)use of the default environment is
1857 discouraged. Make sure to check other ways to preset
1858 the environment like the "source" command or the
1861 - DataFlash Support:
1862 CONFIG_HAS_DATAFLASH
1864 Defining this option enables DataFlash features and
1865 allows to read/write in Dataflash via the standard
1868 - SystemACE Support:
1871 Adding this option adds support for Xilinx SystemACE
1872 chips attached via some sort of local bus. The address
1873 of the chip must also be defined in the
1874 CONFIG_SYS_SYSTEMACE_BASE macro. For example:
1876 #define CONFIG_SYSTEMACE
1877 #define CONFIG_SYS_SYSTEMACE_BASE 0xf0000000
1879 When SystemACE support is added, the "ace" device type
1880 becomes available to the fat commands, i.e. fatls.
1882 - TFTP Fixed UDP Port:
1885 If this is defined, the environment variable tftpsrcp
1886 is used to supply the TFTP UDP source port value.
1887 If tftpsrcp isn't defined, the normal pseudo-random port
1888 number generator is used.
1890 Also, the environment variable tftpdstp is used to supply
1891 the TFTP UDP destination port value. If tftpdstp isn't
1892 defined, the normal port 69 is used.
1894 The purpose for tftpsrcp is to allow a TFTP server to
1895 blindly start the TFTP transfer using the pre-configured
1896 target IP address and UDP port. This has the effect of
1897 "punching through" the (Windows XP) firewall, allowing
1898 the remainder of the TFTP transfer to proceed normally.
1899 A better solution is to properly configure the firewall,
1900 but sometimes that is not allowed.
1902 - Show boot progress:
1903 CONFIG_SHOW_BOOT_PROGRESS
1905 Defining this option allows to add some board-
1906 specific code (calling a user-provided function
1907 "show_boot_progress(int)") that enables you to show
1908 the system's boot progress on some display (for
1909 example, some LED's) on your board. At the moment,
1910 the following checkpoints are implemented:
1912 Legacy uImage format:
1915 1 common/cmd_bootm.c before attempting to boot an image
1916 -1 common/cmd_bootm.c Image header has bad magic number
1917 2 common/cmd_bootm.c Image header has correct magic number
1918 -2 common/cmd_bootm.c Image header has bad checksum
1919 3 common/cmd_bootm.c Image header has correct checksum
1920 -3 common/cmd_bootm.c Image data has bad checksum
1921 4 common/cmd_bootm.c Image data has correct checksum
1922 -4 common/cmd_bootm.c Image is for unsupported architecture
1923 5 common/cmd_bootm.c Architecture check OK
1924 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi)
1925 6 common/cmd_bootm.c Image Type check OK
1926 -6 common/cmd_bootm.c gunzip uncompression error
1927 -7 common/cmd_bootm.c Unimplemented compression type
1928 7 common/cmd_bootm.c Uncompression OK
1929 8 common/cmd_bootm.c No uncompress/copy overwrite error
1930 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX)
1932 9 common/image.c Start initial ramdisk verification
1933 -10 common/image.c Ramdisk header has bad magic number
1934 -11 common/image.c Ramdisk header has bad checksum
1935 10 common/image.c Ramdisk header is OK
1936 -12 common/image.c Ramdisk data has bad checksum
1937 11 common/image.c Ramdisk data has correct checksum
1938 12 common/image.c Ramdisk verification complete, start loading
1939 -13 common/image.c Wrong Image Type (not PPC Linux ramdisk)
1940 13 common/image.c Start multifile image verification
1941 14 common/image.c No initial ramdisk, no multifile, continue.
1943 15 arch/<arch>/lib/bootm.c All preparation done, transferring control to OS
1945 -30 arch/ppc/lib/board.c Fatal error, hang the system
1946 -31 post/post.c POST test failed, detected by post_output_backlog()
1947 -32 post/post.c POST test failed, detected by post_run_single()
1949 34 common/cmd_doc.c before loading a Image from a DOC device
1950 -35 common/cmd_doc.c Bad usage of "doc" command
1951 35 common/cmd_doc.c correct usage of "doc" command
1952 -36 common/cmd_doc.c No boot device
1953 36 common/cmd_doc.c correct boot device
1954 -37 common/cmd_doc.c Unknown Chip ID on boot device
1955 37 common/cmd_doc.c correct chip ID found, device available
1956 -38 common/cmd_doc.c Read Error on boot device
1957 38 common/cmd_doc.c reading Image header from DOC device OK
1958 -39 common/cmd_doc.c Image header has bad magic number
1959 39 common/cmd_doc.c Image header has correct magic number
1960 -40 common/cmd_doc.c Error reading Image from DOC device
1961 40 common/cmd_doc.c Image header has correct magic number
1962 41 common/cmd_ide.c before loading a Image from a IDE device
1963 -42 common/cmd_ide.c Bad usage of "ide" command
1964 42 common/cmd_ide.c correct usage of "ide" command
1965 -43 common/cmd_ide.c No boot device
1966 43 common/cmd_ide.c boot device found
1967 -44 common/cmd_ide.c Device not available
1968 44 common/cmd_ide.c Device available
1969 -45 common/cmd_ide.c wrong partition selected
1970 45 common/cmd_ide.c partition selected
1971 -46 common/cmd_ide.c Unknown partition table
1972 46 common/cmd_ide.c valid partition table found
1973 -47 common/cmd_ide.c Invalid partition type
1974 47 common/cmd_ide.c correct partition type
1975 -48 common/cmd_ide.c Error reading Image Header on boot device
1976 48 common/cmd_ide.c reading Image Header from IDE device OK
1977 -49 common/cmd_ide.c Image header has bad magic number
1978 49 common/cmd_ide.c Image header has correct magic number
1979 -50 common/cmd_ide.c Image header has bad checksum
1980 50 common/cmd_ide.c Image header has correct checksum
1981 -51 common/cmd_ide.c Error reading Image from IDE device
1982 51 common/cmd_ide.c reading Image from IDE device OK
1983 52 common/cmd_nand.c before loading a Image from a NAND device
1984 -53 common/cmd_nand.c Bad usage of "nand" command
1985 53 common/cmd_nand.c correct usage of "nand" command
1986 -54 common/cmd_nand.c No boot device
1987 54 common/cmd_nand.c boot device found
1988 -55 common/cmd_nand.c Unknown Chip ID on boot device
1989 55 common/cmd_nand.c correct chip ID found, device available
1990 -56 common/cmd_nand.c Error reading Image Header on boot device
1991 56 common/cmd_nand.c reading Image Header from NAND device OK
1992 -57 common/cmd_nand.c Image header has bad magic number
1993 57 common/cmd_nand.c Image header has correct magic number
1994 -58 common/cmd_nand.c Error reading Image from NAND device
1995 58 common/cmd_nand.c reading Image from NAND device OK
1997 -60 common/env_common.c Environment has a bad CRC, using default
1999 64 net/eth.c starting with Ethernet configuration.
2000 -64 net/eth.c no Ethernet found.
2001 65 net/eth.c Ethernet found.
2003 -80 common/cmd_net.c usage wrong
2004 80 common/cmd_net.c before calling NetLoop()
2005 -81 common/cmd_net.c some error in NetLoop() occurred
2006 81 common/cmd_net.c NetLoop() back without error
2007 -82 common/cmd_net.c size == 0 (File with size 0 loaded)
2008 82 common/cmd_net.c trying automatic boot
2009 83 common/cmd_net.c running "source" command
2010 -83 common/cmd_net.c some error in automatic boot or "source" command
2011 84 common/cmd_net.c end without errors
2016 100 common/cmd_bootm.c Kernel FIT Image has correct format
2017 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format
2018 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration
2019 -101 common/cmd_bootm.c Can't get configuration for kernel subimage
2020 102 common/cmd_bootm.c Kernel unit name specified
2021 -103 common/cmd_bootm.c Can't get kernel subimage node offset
2022 103 common/cmd_bootm.c Found configuration node
2023 104 common/cmd_bootm.c Got kernel subimage node offset
2024 -104 common/cmd_bootm.c Kernel subimage hash verification failed
2025 105 common/cmd_bootm.c Kernel subimage hash verification OK
2026 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture
2027 106 common/cmd_bootm.c Architecture check OK
2028 -106 common/cmd_bootm.c Kernel subimage has wrong type
2029 107 common/cmd_bootm.c Kernel subimage type OK
2030 -107 common/cmd_bootm.c Can't get kernel subimage data/size
2031 108 common/cmd_bootm.c Got kernel subimage data/size
2032 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT)
2033 -109 common/cmd_bootm.c Can't get kernel subimage type
2034 -110 common/cmd_bootm.c Can't get kernel subimage comp
2035 -111 common/cmd_bootm.c Can't get kernel subimage os
2036 -112 common/cmd_bootm.c Can't get kernel subimage load address
2037 -113 common/cmd_bootm.c Image uncompress/copy overwrite error
2039 120 common/image.c Start initial ramdisk verification
2040 -120 common/image.c Ramdisk FIT image has incorrect format
2041 121 common/image.c Ramdisk FIT image has correct format
2042 122 common/image.c No ramdisk subimage unit name, using configuration
2043 -122 common/image.c Can't get configuration for ramdisk subimage
2044 123 common/image.c Ramdisk unit name specified
2045 -124 common/image.c Can't get ramdisk subimage node offset
2046 125 common/image.c Got ramdisk subimage node offset
2047 -125 common/image.c Ramdisk subimage hash verification failed
2048 126 common/image.c Ramdisk subimage hash verification OK
2049 -126 common/image.c Ramdisk subimage for unsupported architecture
2050 127 common/image.c Architecture check OK
2051 -127 common/image.c Can't get ramdisk subimage data/size
2052 128 common/image.c Got ramdisk subimage data/size
2053 129 common/image.c Can't get ramdisk load address
2054 -129 common/image.c Got ramdisk load address
2056 -130 common/cmd_doc.c Incorrect FIT image format
2057 131 common/cmd_doc.c FIT image format OK
2059 -140 common/cmd_ide.c Incorrect FIT image format
2060 141 common/cmd_ide.c FIT image format OK
2062 -150 common/cmd_nand.c Incorrect FIT image format
2063 151 common/cmd_nand.c FIT image format OK
2065 - Automatic software updates via TFTP server
2067 CONFIG_UPDATE_TFTP_CNT_MAX
2068 CONFIG_UPDATE_TFTP_MSEC_MAX
2070 These options enable and control the auto-update feature;
2071 for a more detailed description refer to doc/README.update.
2073 - MTD Support (mtdparts command, UBI support)
2076 Adds the MTD device infrastructure from the Linux kernel.
2077 Needed for mtdparts command support.
2079 CONFIG_MTD_PARTITIONS
2081 Adds the MTD partitioning infrastructure from the Linux
2082 kernel. Needed for UBI support.
2088 [so far only for SMDK2400 and TRAB boards]
2090 - Modem support enable:
2091 CONFIG_MODEM_SUPPORT
2093 - RTS/CTS Flow control enable:
2096 - Modem debug support:
2097 CONFIG_MODEM_SUPPORT_DEBUG
2099 Enables debugging stuff (char screen[1024], dbg())
2100 for modem support. Useful only with BDI2000.
2102 - Interrupt support (PPC):
2104 There are common interrupt_init() and timer_interrupt()
2105 for all PPC archs. interrupt_init() calls interrupt_init_cpu()
2106 for CPU specific initialization. interrupt_init_cpu()
2107 should set decrementer_count to appropriate value. If
2108 CPU resets decrementer automatically after interrupt
2109 (ppc4xx) it should set decrementer_count to zero.
2110 timer_interrupt() calls timer_interrupt_cpu() for CPU
2111 specific handling. If board has watchdog / status_led
2112 / other_activity_monitor it works automatically from
2113 general timer_interrupt().
2117 In the target system modem support is enabled when a
2118 specific key (key combination) is pressed during
2119 power-on. Otherwise U-Boot will boot normally
2120 (autoboot). The key_pressed() function is called from
2121 board_init(). Currently key_pressed() is a dummy
2122 function, returning 1 and thus enabling modem
2125 If there are no modem init strings in the
2126 environment, U-Boot proceed to autoboot; the
2127 previous output (banner, info printfs) will be
2130 See also: doc/README.Modem
2133 Configuration Settings:
2134 -----------------------
2136 - CONFIG_SYS_LONGHELP: Defined when you want long help messages included;
2137 undefine this when you're short of memory.
2139 - CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default
2140 width of the commands listed in the 'help' command output.
2142 - CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to
2143 prompt for user input.
2145 - CONFIG_SYS_CBSIZE: Buffer size for input from the Console
2147 - CONFIG_SYS_PBSIZE: Buffer size for Console output
2149 - CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands
2151 - CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to
2152 the application (usually a Linux kernel) when it is
2155 - CONFIG_SYS_BAUDRATE_TABLE:
2156 List of legal baudrate settings for this board.
2158 - CONFIG_SYS_CONSOLE_INFO_QUIET
2159 Suppress display of console information at boot.
2161 - CONFIG_SYS_CONSOLE_IS_IN_ENV
2162 If the board specific function
2163 extern int overwrite_console (void);
2164 returns 1, the stdin, stderr and stdout are switched to the
2165 serial port, else the settings in the environment are used.
2167 - CONFIG_SYS_CONSOLE_OVERWRITE_ROUTINE
2168 Enable the call to overwrite_console().
2170 - CONFIG_SYS_CONSOLE_ENV_OVERWRITE
2171 Enable overwrite of previous console environment settings.
2173 - CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END:
2174 Begin and End addresses of the area used by the
2177 - CONFIG_SYS_ALT_MEMTEST:
2178 Enable an alternate, more extensive memory test.
2180 - CONFIG_SYS_MEMTEST_SCRATCH:
2181 Scratch address used by the alternate memory test
2182 You only need to set this if address zero isn't writeable
2184 - CONFIG_SYS_MEM_TOP_HIDE (PPC only):
2185 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header,
2186 this specified memory area will get subtracted from the top
2187 (end) of RAM and won't get "touched" at all by U-Boot. By
2188 fixing up gd->ram_size the Linux kernel should gets passed
2189 the now "corrected" memory size and won't touch it either.
2190 This should work for arch/ppc and arch/powerpc. Only Linux
2191 board ports in arch/powerpc with bootwrapper support that
2192 recalculate the memory size from the SDRAM controller setup
2193 will have to get fixed in Linux additionally.
2195 This option can be used as a workaround for the 440EPx/GRx
2196 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't
2199 WARNING: Please make sure that this value is a multiple of
2200 the Linux page size (normally 4k). If this is not the case,
2201 then the end address of the Linux memory will be located at a
2202 non page size aligned address and this could cause major
2205 - CONFIG_SYS_TFTP_LOADADDR:
2206 Default load address for network file downloads
2208 - CONFIG_SYS_LOADS_BAUD_CHANGE:
2209 Enable temporary baudrate change while serial download
2211 - CONFIG_SYS_SDRAM_BASE:
2212 Physical start address of SDRAM. _Must_ be 0 here.
2214 - CONFIG_SYS_MBIO_BASE:
2215 Physical start address of Motherboard I/O (if using a
2218 - CONFIG_SYS_FLASH_BASE:
2219 Physical start address of Flash memory.
2221 - CONFIG_SYS_MONITOR_BASE:
2222 Physical start address of boot monitor code (set by
2223 make config files to be same as the text base address
2224 (TEXT_BASE) used when linking) - same as
2225 CONFIG_SYS_FLASH_BASE when booting from flash.
2227 - CONFIG_SYS_MONITOR_LEN:
2228 Size of memory reserved for monitor code, used to
2229 determine _at_compile_time_ (!) if the environment is
2230 embedded within the U-Boot image, or in a separate
2233 - CONFIG_SYS_MALLOC_LEN:
2234 Size of DRAM reserved for malloc() use.
2236 - CONFIG_SYS_BOOTM_LEN:
2237 Normally compressed uImages are limited to an
2238 uncompressed size of 8 MBytes. If this is not enough,
2239 you can define CONFIG_SYS_BOOTM_LEN in your board config file
2240 to adjust this setting to your needs.
2242 - CONFIG_SYS_BOOTMAPSZ:
2243 Maximum size of memory mapped by the startup code of
2244 the Linux kernel; all data that must be processed by
2245 the Linux kernel (bd_info, boot arguments, FDT blob if
2246 used) must be put below this limit, unless "bootm_low"
2247 enviroment variable is defined and non-zero. In such case
2248 all data for the Linux kernel must be between "bootm_low"
2249 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ.
2251 - CONFIG_SYS_MAX_FLASH_BANKS:
2252 Max number of Flash memory banks
2254 - CONFIG_SYS_MAX_FLASH_SECT:
2255 Max number of sectors on a Flash chip
2257 - CONFIG_SYS_FLASH_ERASE_TOUT:
2258 Timeout for Flash erase operations (in ms)
2260 - CONFIG_SYS_FLASH_WRITE_TOUT:
2261 Timeout for Flash write operations (in ms)
2263 - CONFIG_SYS_FLASH_LOCK_TOUT
2264 Timeout for Flash set sector lock bit operation (in ms)
2266 - CONFIG_SYS_FLASH_UNLOCK_TOUT
2267 Timeout for Flash clear lock bits operation (in ms)
2269 - CONFIG_SYS_FLASH_PROTECTION
2270 If defined, hardware flash sectors protection is used
2271 instead of U-Boot software protection.
2273 - CONFIG_SYS_DIRECT_FLASH_TFTP:
2275 Enable TFTP transfers directly to flash memory;
2276 without this option such a download has to be
2277 performed in two steps: (1) download to RAM, and (2)
2278 copy from RAM to flash.
2280 The two-step approach is usually more reliable, since
2281 you can check if the download worked before you erase
2282 the flash, but in some situations (when system RAM is
2283 too limited to allow for a temporary copy of the
2284 downloaded image) this option may be very useful.
2286 - CONFIG_SYS_FLASH_CFI:
2287 Define if the flash driver uses extra elements in the
2288 common flash structure for storing flash geometry.
2290 - CONFIG_FLASH_CFI_DRIVER
2291 This option also enables the building of the cfi_flash driver
2292 in the drivers directory
2294 - CONFIG_FLASH_CFI_MTD
2295 This option enables the building of the cfi_mtd driver
2296 in the drivers directory. The driver exports CFI flash
2299 - CONFIG_SYS_FLASH_USE_BUFFER_WRITE
2300 Use buffered writes to flash.
2302 - CONFIG_FLASH_SPANSION_S29WS_N
2303 s29ws-n MirrorBit flash has non-standard addresses for buffered
2306 - CONFIG_SYS_FLASH_QUIET_TEST
2307 If this option is defined, the common CFI flash doesn't
2308 print it's warning upon not recognized FLASH banks. This
2309 is useful, if some of the configured banks are only
2310 optionally available.
2312 - CONFIG_FLASH_SHOW_PROGRESS
2313 If defined (must be an integer), print out countdown
2314 digits and dots. Recommended value: 45 (9..1) for 80
2315 column displays, 15 (3..1) for 40 column displays.
2317 - CONFIG_SYS_RX_ETH_BUFFER:
2318 Defines the number of Ethernet receive buffers. On some
2319 Ethernet controllers it is recommended to set this value
2320 to 8 or even higher (EEPRO100 or 405 EMAC), since all
2321 buffers can be full shortly after enabling the interface
2322 on high Ethernet traffic.
2323 Defaults to 4 if not defined.
2325 The following definitions that deal with the placement and management
2326 of environment data (variable area); in general, we support the
2327 following configurations:
2329 - CONFIG_ENV_IS_IN_FLASH:
2331 Define this if the environment is in flash memory.
2333 a) The environment occupies one whole flash sector, which is
2334 "embedded" in the text segment with the U-Boot code. This
2335 happens usually with "bottom boot sector" or "top boot
2336 sector" type flash chips, which have several smaller
2337 sectors at the start or the end. For instance, such a
2338 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In
2339 such a case you would place the environment in one of the
2340 4 kB sectors - with U-Boot code before and after it. With
2341 "top boot sector" type flash chips, you would put the
2342 environment in one of the last sectors, leaving a gap
2343 between U-Boot and the environment.
2345 - CONFIG_ENV_OFFSET:
2347 Offset of environment data (variable area) to the
2348 beginning of flash memory; for instance, with bottom boot
2349 type flash chips the second sector can be used: the offset
2350 for this sector is given here.
2352 CONFIG_ENV_OFFSET is used relative to CONFIG_SYS_FLASH_BASE.
2356 This is just another way to specify the start address of
2357 the flash sector containing the environment (instead of
2360 - CONFIG_ENV_SECT_SIZE:
2362 Size of the sector containing the environment.
2365 b) Sometimes flash chips have few, equal sized, BIG sectors.
2366 In such a case you don't want to spend a whole sector for
2371 If you use this in combination with CONFIG_ENV_IS_IN_FLASH
2372 and CONFIG_ENV_SECT_SIZE, you can specify to use only a part
2373 of this flash sector for the environment. This saves
2374 memory for the RAM copy of the environment.
2376 It may also save flash memory if you decide to use this
2377 when your environment is "embedded" within U-Boot code,
2378 since then the remainder of the flash sector could be used
2379 for U-Boot code. It should be pointed out that this is
2380 STRONGLY DISCOURAGED from a robustness point of view:
2381 updating the environment in flash makes it always
2382 necessary to erase the WHOLE sector. If something goes
2383 wrong before the contents has been restored from a copy in
2384 RAM, your target system will be dead.
2386 - CONFIG_ENV_ADDR_REDUND
2387 CONFIG_ENV_SIZE_REDUND
2389 These settings describe a second storage area used to hold
2390 a redundant copy of the environment data, so that there is
2391 a valid backup copy in case there is a power failure during
2392 a "saveenv" operation.
2394 BE CAREFUL! Any changes to the flash layout, and some changes to the
2395 source code will make it necessary to adapt <board>/u-boot.lds*
2399 - CONFIG_ENV_IS_IN_NVRAM:
2401 Define this if you have some non-volatile memory device
2402 (NVRAM, battery buffered SRAM) which you want to use for the
2408 These two #defines are used to determine the memory area you
2409 want to use for environment. It is assumed that this memory
2410 can just be read and written to, without any special
2413 BE CAREFUL! The first access to the environment happens quite early
2414 in U-Boot initalization (when we try to get the setting of for the
2415 console baudrate). You *MUST* have mapped your NVRAM area then, or
2418 Please note that even with NVRAM we still use a copy of the
2419 environment in RAM: we could work on NVRAM directly, but we want to
2420 keep settings there always unmodified except somebody uses "saveenv"
2421 to save the current settings.
2424 - CONFIG_ENV_IS_IN_EEPROM:
2426 Use this if you have an EEPROM or similar serial access
2427 device and a driver for it.
2429 - CONFIG_ENV_OFFSET:
2432 These two #defines specify the offset and size of the
2433 environment area within the total memory of your EEPROM.
2435 - CONFIG_SYS_I2C_EEPROM_ADDR:
2436 If defined, specified the chip address of the EEPROM device.
2437 The default address is zero.
2439 - CONFIG_SYS_EEPROM_PAGE_WRITE_BITS:
2440 If defined, the number of bits used to address bytes in a
2441 single page in the EEPROM device. A 64 byte page, for example
2442 would require six bits.
2444 - CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS:
2445 If defined, the number of milliseconds to delay between
2446 page writes. The default is zero milliseconds.
2448 - CONFIG_SYS_I2C_EEPROM_ADDR_LEN:
2449 The length in bytes of the EEPROM memory array address. Note
2450 that this is NOT the chip address length!
2452 - CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW:
2453 EEPROM chips that implement "address overflow" are ones
2454 like Catalyst 24WC04/08/16 which has 9/10/11 bits of
2455 address and the extra bits end up in the "chip address" bit
2456 slots. This makes a 24WC08 (1Kbyte) chip look like four 256
2459 Note that we consider the length of the address field to
2460 still be one byte because the extra address bits are hidden
2461 in the chip address.
2463 - CONFIG_SYS_EEPROM_SIZE:
2464 The size in bytes of the EEPROM device.
2466 - CONFIG_ENV_EEPROM_IS_ON_I2C
2467 define this, if you have I2C and SPI activated, and your
2468 EEPROM, which holds the environment, is on the I2C bus.
2470 - CONFIG_I2C_ENV_EEPROM_BUS
2471 if you have an Environment on an EEPROM reached over
2472 I2C muxes, you can define here, how to reach this
2473 EEPROM. For example:
2475 #define CONFIG_I2C_ENV_EEPROM_BUS "pca9547:70:d\0"
2477 EEPROM which holds the environment, is reached over
2478 a pca9547 i2c mux with address 0x70, channel 3.
2480 - CONFIG_ENV_IS_IN_DATAFLASH:
2482 Define this if you have a DataFlash memory device which you
2483 want to use for the environment.
2485 - CONFIG_ENV_OFFSET:
2489 These three #defines specify the offset and size of the
2490 environment area within the total memory of your DataFlash placed
2491 at the specified address.
2493 - CONFIG_ENV_IS_IN_NAND:
2495 Define this if you have a NAND device which you want to use
2496 for the environment.
2498 - CONFIG_ENV_OFFSET:
2501 These two #defines specify the offset and size of the environment
2502 area within the first NAND device.
2504 - CONFIG_ENV_OFFSET_REDUND
2506 This setting describes a second storage area of CONFIG_ENV_SIZE
2507 size used to hold a redundant copy of the environment data,
2508 so that there is a valid backup copy in case there is a
2509 power failure during a "saveenv" operation.
2511 Note: CONFIG_ENV_OFFSET and CONFIG_ENV_OFFSET_REDUND must be aligned
2512 to a block boundary, and CONFIG_ENV_SIZE must be a multiple of
2513 the NAND devices block size.
2515 - CONFIG_NAND_ENV_DST
2517 Defines address in RAM to which the nand_spl code should copy the
2518 environment. If redundant environment is used, it will be copied to
2519 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE.
2521 - CONFIG_SYS_SPI_INIT_OFFSET
2523 Defines offset to the initial SPI buffer area in DPRAM. The
2524 area is used at an early stage (ROM part) if the environment
2525 is configured to reside in the SPI EEPROM: We need a 520 byte
2526 scratch DPRAM area. It is used between the two initialization
2527 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems
2528 to be a good choice since it makes it far enough from the
2529 start of the data area as well as from the stack pointer.
2531 Please note that the environment is read-only until the monitor
2532 has been relocated to RAM and a RAM copy of the environment has been
2533 created; also, when using EEPROM you will have to use getenv_r()
2534 until then to read environment variables.
2536 The environment is protected by a CRC32 checksum. Before the monitor
2537 is relocated into RAM, as a result of a bad CRC you will be working
2538 with the compiled-in default environment - *silently*!!! [This is
2539 necessary, because the first environment variable we need is the
2540 "baudrate" setting for the console - if we have a bad CRC, we don't
2541 have any device yet where we could complain.]
2543 Note: once the monitor has been relocated, then it will complain if
2544 the default environment is used; a new CRC is computed as soon as you
2545 use the "saveenv" command to store a valid environment.
2547 - CONFIG_SYS_FAULT_ECHO_LINK_DOWN:
2548 Echo the inverted Ethernet link state to the fault LED.
2550 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR
2551 also needs to be defined.
2553 - CONFIG_SYS_FAULT_MII_ADDR:
2554 MII address of the PHY to check for the Ethernet link state.
2556 - CONFIG_NS16550_MIN_FUNCTIONS:
2557 Define this if you desire to only have use of the NS16550_init
2558 and NS16550_putc functions for the serial driver located at
2559 drivers/serial/ns16550.c. This option is useful for saving
2560 space for already greatly restricted images, including but not
2561 limited to NAND_SPL configurations.
2563 Low Level (hardware related) configuration options:
2564 ---------------------------------------------------
2566 - CONFIG_SYS_CACHELINE_SIZE:
2567 Cache Line Size of the CPU.
2569 - CONFIG_SYS_DEFAULT_IMMR:
2570 Default address of the IMMR after system reset.
2572 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU,
2573 and RPXsuper) to be able to adjust the position of
2574 the IMMR register after a reset.
2576 - Floppy Disk Support:
2577 CONFIG_SYS_FDC_DRIVE_NUMBER
2579 the default drive number (default value 0)
2581 CONFIG_SYS_ISA_IO_STRIDE
2583 defines the spacing between FDC chipset registers
2586 CONFIG_SYS_ISA_IO_OFFSET
2588 defines the offset of register from address. It
2589 depends on which part of the data bus is connected to
2590 the FDC chipset. (default value 0)
2592 If CONFIG_SYS_ISA_IO_STRIDE CONFIG_SYS_ISA_IO_OFFSET and
2593 CONFIG_SYS_FDC_DRIVE_NUMBER are undefined, they take their
2596 if CONFIG_SYS_FDC_HW_INIT is defined, then the function
2597 fdc_hw_init() is called at the beginning of the FDC
2598 setup. fdc_hw_init() must be provided by the board
2599 source code. It is used to make hardware dependant
2602 - CONFIG_SYS_IMMR: Physical address of the Internal Memory.
2603 DO NOT CHANGE unless you know exactly what you're
2604 doing! (11-4) [MPC8xx/82xx systems only]
2606 - CONFIG_SYS_INIT_RAM_ADDR:
2608 Start address of memory area that can be used for
2609 initial data and stack; please note that this must be
2610 writable memory that is working WITHOUT special
2611 initialization, i. e. you CANNOT use normal RAM which
2612 will become available only after programming the
2613 memory controller and running certain initialization
2616 U-Boot uses the following memory types:
2617 - MPC8xx and MPC8260: IMMR (internal memory of the CPU)
2618 - MPC824X: data cache
2619 - PPC4xx: data cache
2621 - CONFIG_SYS_GBL_DATA_OFFSET:
2623 Offset of the initial data structure in the memory
2624 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually
2625 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial
2626 data is located at the end of the available space
2627 (sometimes written as (CONFIG_SYS_INIT_RAM_END -
2628 CONFIG_SYS_INIT_DATA_SIZE), and the initial stack is just
2629 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR +
2630 CONFIG_SYS_GBL_DATA_OFFSET) downward.
2633 On the MPC824X (or other systems that use the data
2634 cache for initial memory) the address chosen for
2635 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must
2636 point to an otherwise UNUSED address space between
2637 the top of RAM and the start of the PCI space.
2639 - CONFIG_SYS_SIUMCR: SIU Module Configuration (11-6)
2641 - CONFIG_SYS_SYPCR: System Protection Control (11-9)
2643 - CONFIG_SYS_TBSCR: Time Base Status and Control (11-26)
2645 - CONFIG_SYS_PISCR: Periodic Interrupt Status and Control (11-31)
2647 - CONFIG_SYS_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30)
2649 - CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27)
2651 - CONFIG_SYS_OR_TIMING_SDRAM:
2654 - CONFIG_SYS_MAMR_PTA:
2655 periodic timer for refresh
2657 - CONFIG_SYS_DER: Debug Event Register (37-47)
2659 - FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM,
2660 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP,
2661 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM,
2662 CONFIG_SYS_BR1_PRELIM:
2663 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
2665 - SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
2666 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM,
2667 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM:
2668 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
2670 - CONFIG_SYS_MAMR_PTA, CONFIG_SYS_MPTPR_2BK_4K, CONFIG_SYS_MPTPR_1BK_4K, CONFIG_SYS_MPTPR_2BK_8K,
2671 CONFIG_SYS_MPTPR_1BK_8K, CONFIG_SYS_MAMR_8COL, CONFIG_SYS_MAMR_9COL:
2672 Machine Mode Register and Memory Periodic Timer
2673 Prescaler definitions (SDRAM timing)
2675 - CONFIG_SYS_I2C_UCODE_PATCH, CONFIG_SYS_I2C_DPMEM_OFFSET [0x1FC0]:
2676 enable I2C microcode relocation patch (MPC8xx);
2677 define relocation offset in DPRAM [DSP2]
2679 - CONFIG_SYS_SMC_UCODE_PATCH, CONFIG_SYS_SMC_DPMEM_OFFSET [0x1FC0]:
2680 enable SMC microcode relocation patch (MPC8xx);
2681 define relocation offset in DPRAM [SMC1]
2683 - CONFIG_SYS_SPI_UCODE_PATCH, CONFIG_SYS_SPI_DPMEM_OFFSET [0x1FC0]:
2684 enable SPI microcode relocation patch (MPC8xx);
2685 define relocation offset in DPRAM [SCC4]
2687 - CONFIG_SYS_USE_OSCCLK:
2688 Use OSCM clock mode on MBX8xx board. Be careful,
2689 wrong setting might damage your board. Read
2690 doc/README.MBX before setting this variable!
2692 - CONFIG_SYS_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only)
2693 Offset of the bootmode word in DPRAM used by post
2694 (Power On Self Tests). This definition overrides
2695 #define'd default value in commproc.h resp.
2698 - CONFIG_SYS_PCI_SLV_MEM_LOCAL, CONFIG_SYS_PCI_SLV_MEM_BUS, CONFIG_SYS_PICMR0_MASK_ATTRIB,
2699 CONFIG_SYS_PCI_MSTR0_LOCAL, CONFIG_SYS_PCIMSK0_MASK, CONFIG_SYS_PCI_MSTR1_LOCAL,
2700 CONFIG_SYS_PCIMSK1_MASK, CONFIG_SYS_PCI_MSTR_MEM_LOCAL, CONFIG_SYS_PCI_MSTR_MEM_BUS,
2701 CONFIG_SYS_CPU_PCI_MEM_START, CONFIG_SYS_PCI_MSTR_MEM_SIZE, CONFIG_SYS_POCMR0_MASK_ATTRIB,
2702 CONFIG_SYS_PCI_MSTR_MEMIO_LOCAL, CONFIG_SYS_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START,
2703 CONFIG_SYS_PCI_MSTR_MEMIO_SIZE, CONFIG_SYS_POCMR1_MASK_ATTRIB, CONFIG_SYS_PCI_MSTR_IO_LOCAL,
2704 CONFIG_SYS_PCI_MSTR_IO_BUS, CONFIG_SYS_CPU_PCI_IO_START, CONFIG_SYS_PCI_MSTR_IO_SIZE,
2705 CONFIG_SYS_POCMR2_MASK_ATTRIB: (MPC826x only)
2706 Overrides the default PCI memory map in cpu/mpc8260/pci.c if set.
2708 - CONFIG_PCI_DISABLE_PCIE:
2709 Disable PCI-Express on systems where it is supported but not
2713 Get DDR timing information from an I2C EEPROM. Common
2714 with pluggable memory modules such as SODIMMs
2717 I2C address of the SPD EEPROM
2719 - CONFIG_SYS_SPD_BUS_NUM
2720 If SPD EEPROM is on an I2C bus other than the first
2721 one, specify here. Note that the value must resolve
2722 to something your driver can deal with.
2724 - CONFIG_SYS_83XX_DDR_USES_CS0
2725 Only for 83xx systems. If specified, then DDR should
2726 be configured using CS0 and CS1 instead of CS2 and CS3.
2728 - CONFIG_ETHER_ON_FEC[12]
2729 Define to enable FEC[12] on a 8xx series processor.
2731 - CONFIG_FEC[12]_PHY
2732 Define to the hardcoded PHY address which corresponds
2733 to the given FEC; i. e.
2734 #define CONFIG_FEC1_PHY 4
2735 means that the PHY with address 4 is connected to FEC1
2737 When set to -1, means to probe for first available.
2739 - CONFIG_FEC[12]_PHY_NORXERR
2740 The PHY does not have a RXERR line (RMII only).
2741 (so program the FEC to ignore it).
2744 Enable RMII mode for all FECs.
2745 Note that this is a global option, we can't
2746 have one FEC in standard MII mode and another in RMII mode.
2748 - CONFIG_CRC32_VERIFY
2749 Add a verify option to the crc32 command.
2752 => crc32 -v <address> <count> <crc32>
2754 Where address/count indicate a memory area
2755 and crc32 is the correct crc32 which the
2759 Add the "loopw" memory command. This only takes effect if
2760 the memory commands are activated globally (CONFIG_CMD_MEM).
2763 Add the "mdc" and "mwc" memory commands. These are cyclic
2768 This command will print 4 bytes (10,11,12,13) each 500 ms.
2770 => mwc.l 100 12345678 10
2771 This command will write 12345678 to address 100 all 10 ms.
2773 This only takes effect if the memory commands are activated
2774 globally (CONFIG_CMD_MEM).
2776 - CONFIG_SKIP_LOWLEVEL_INIT
2777 - CONFIG_SKIP_RELOCATE_UBOOT
2779 [ARM only] If these variables are defined, then
2780 certain low level initializations (like setting up
2781 the memory controller) are omitted and/or U-Boot does
2782 not relocate itself into RAM.
2783 Normally these variables MUST NOT be defined. The
2784 only exception is when U-Boot is loaded (to RAM) by
2785 some other boot loader or by a debugger which
2786 performs these initializations itself.
2790 Modifies the behaviour of start.S when compiling a loader
2791 that is executed before the actual U-Boot. E.g. when
2792 compiling a NAND SPL.
2794 Building the Software:
2795 ======================
2797 Building U-Boot has been tested in several native build environments
2798 and in many different cross environments. Of course we cannot support
2799 all possibly existing versions of cross development tools in all
2800 (potentially obsolete) versions. In case of tool chain problems we
2801 recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK)
2802 which is extensively used to build and test U-Boot.
2804 If you are not using a native environment, it is assumed that you
2805 have GNU cross compiling tools available in your path. In this case,
2806 you must set the environment variable CROSS_COMPILE in your shell.
2807 Note that no changes to the Makefile or any other source files are
2808 necessary. For example using the ELDK on a 4xx CPU, please enter:
2810 $ CROSS_COMPILE=ppc_4xx-
2811 $ export CROSS_COMPILE
2813 Note: If you wish to generate Windows versions of the utilities in
2814 the tools directory you can use the MinGW toolchain
2815 (http://www.mingw.org). Set your HOST tools to the MinGW
2816 toolchain and execute 'make tools'. For example:
2818 $ make HOSTCC=i586-mingw32msvc-gcc HOSTSTRIP=i586-mingw32msvc-strip tools
2820 Binaries such as tools/mkimage.exe will be created which can
2821 be executed on computers running Windows.
2823 U-Boot is intended to be simple to build. After installing the
2824 sources you must configure U-Boot for one specific board type. This
2829 where "NAME_config" is the name of one of the existing configu-
2830 rations; see the main Makefile for supported names.
2832 Note: for some board special configuration names may exist; check if
2833 additional information is available from the board vendor; for
2834 instance, the TQM823L systems are available without (standard)
2835 or with LCD support. You can select such additional "features"
2836 when choosing the configuration, i. e.
2839 - will configure for a plain TQM823L, i. e. no LCD support
2841 make TQM823L_LCD_config
2842 - will configure for a TQM823L with U-Boot console on LCD
2847 Finally, type "make all", and you should get some working U-Boot
2848 images ready for download to / installation on your system:
2850 - "u-boot.bin" is a raw binary image
2851 - "u-boot" is an image in ELF binary format
2852 - "u-boot.srec" is in Motorola S-Record format
2854 By default the build is performed locally and the objects are saved
2855 in the source directory. One of the two methods can be used to change
2856 this behavior and build U-Boot to some external directory:
2858 1. Add O= to the make command line invocations:
2860 make O=/tmp/build distclean
2861 make O=/tmp/build NAME_config
2862 make O=/tmp/build all
2864 2. Set environment variable BUILD_DIR to point to the desired location:
2866 export BUILD_DIR=/tmp/build
2871 Note that the command line "O=" setting overrides the BUILD_DIR environment
2875 Please be aware that the Makefiles assume you are using GNU make, so
2876 for instance on NetBSD you might need to use "gmake" instead of
2880 If the system board that you have is not listed, then you will need
2881 to port U-Boot to your hardware platform. To do this, follow these
2884 1. Add a new configuration option for your board to the toplevel
2885 "Makefile" and to the "MAKEALL" script, using the existing
2886 entries as examples. Note that here and at many other places
2887 boards and other names are listed in alphabetical sort order. Please
2889 2. Create a new directory to hold your board specific code. Add any
2890 files you need. In your board directory, you will need at least
2891 the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds".
2892 3. Create a new configuration file "include/configs/<board>.h" for
2894 3. If you're porting U-Boot to a new CPU, then also create a new
2895 directory to hold your CPU specific code. Add any files you need.
2896 4. Run "make <board>_config" with your new name.
2897 5. Type "make", and you should get a working "u-boot.srec" file
2898 to be installed on your target system.
2899 6. Debug and solve any problems that might arise.
2900 [Of course, this last step is much harder than it sounds.]
2903 Testing of U-Boot Modifications, Ports to New Hardware, etc.:
2904 ==============================================================
2906 If you have modified U-Boot sources (for instance added a new board
2907 or support for new devices, a new CPU, etc.) you are expected to
2908 provide feedback to the other developers. The feedback normally takes
2909 the form of a "patch", i. e. a context diff against a certain (latest
2910 official or latest in the git repository) version of U-Boot sources.
2912 But before you submit such a patch, please verify that your modifi-
2913 cation did not break existing code. At least make sure that *ALL* of
2914 the supported boards compile WITHOUT ANY compiler warnings. To do so,
2915 just run the "MAKEALL" script, which will configure and build U-Boot
2916 for ALL supported system. Be warned, this will take a while. You can
2917 select which (cross) compiler to use by passing a `CROSS_COMPILE'
2918 environment variable to the script, i. e. to use the ELDK cross tools
2921 CROSS_COMPILE=ppc_8xx- MAKEALL
2923 or to build on a native PowerPC system you can type
2925 CROSS_COMPILE=' ' MAKEALL
2927 When using the MAKEALL script, the default behaviour is to build
2928 U-Boot in the source directory. This location can be changed by
2929 setting the BUILD_DIR environment variable. Also, for each target
2930 built, the MAKEALL script saves two log files (<target>.ERR and
2931 <target>.MAKEALL) in the <source dir>/LOG directory. This default
2932 location can be changed by setting the MAKEALL_LOGDIR environment
2933 variable. For example:
2935 export BUILD_DIR=/tmp/build
2936 export MAKEALL_LOGDIR=/tmp/log
2937 CROSS_COMPILE=ppc_8xx- MAKEALL
2939 With the above settings build objects are saved in the /tmp/build,
2940 log files are saved in the /tmp/log and the source tree remains clean
2941 during the whole build process.
2944 See also "U-Boot Porting Guide" below.
2947 Monitor Commands - Overview:
2948 ============================
2950 go - start application at address 'addr'
2951 run - run commands in an environment variable
2952 bootm - boot application image from memory
2953 bootp - boot image via network using BootP/TFTP protocol
2954 tftpboot- boot image via network using TFTP protocol
2955 and env variables "ipaddr" and "serverip"
2956 (and eventually "gatewayip")
2957 rarpboot- boot image via network using RARP/TFTP protocol
2958 diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
2959 loads - load S-Record file over serial line
2960 loadb - load binary file over serial line (kermit mode)
2962 mm - memory modify (auto-incrementing)
2963 nm - memory modify (constant address)
2964 mw - memory write (fill)
2966 cmp - memory compare
2967 crc32 - checksum calculation
2968 i2c - I2C sub-system
2969 sspi - SPI utility commands
2970 base - print or set address offset
2971 printenv- print environment variables
2972 setenv - set environment variables
2973 saveenv - save environment variables to persistent storage
2974 protect - enable or disable FLASH write protection
2975 erase - erase FLASH memory
2976 flinfo - print FLASH memory information
2977 bdinfo - print Board Info structure
2978 iminfo - print header information for application image
2979 coninfo - print console devices and informations
2980 ide - IDE sub-system
2981 loop - infinite loop on address range
2982 loopw - infinite write loop on address range
2983 mtest - simple RAM test
2984 icache - enable or disable instruction cache
2985 dcache - enable or disable data cache
2986 reset - Perform RESET of the CPU
2987 echo - echo args to console
2988 version - print monitor version
2989 help - print online help
2990 ? - alias for 'help'
2993 Monitor Commands - Detailed Description:
2994 ========================================
2998 For now: just type "help <command>".
3001 Environment Variables:
3002 ======================
3004 U-Boot supports user configuration using Environment Variables which
3005 can be made persistent by saving to Flash memory.
3007 Environment Variables are set using "setenv", printed using
3008 "printenv", and saved to Flash using "saveenv". Using "setenv"
3009 without a value can be used to delete a variable from the
3010 environment. As long as you don't save the environment you are
3011 working with an in-memory copy. In case the Flash area containing the
3012 environment is erased by accident, a default environment is provided.
3014 Some configuration options can be set using Environment Variables.
3016 List of environment variables (most likely not complete):
3018 baudrate - see CONFIG_BAUDRATE
3020 bootdelay - see CONFIG_BOOTDELAY
3022 bootcmd - see CONFIG_BOOTCOMMAND
3024 bootargs - Boot arguments when booting an RTOS image
3026 bootfile - Name of the image to load with TFTP
3028 bootm_low - Memory range available for image processing in the bootm
3029 command can be restricted. This variable is given as
3030 a hexadecimal number and defines lowest address allowed
3031 for use by the bootm command. See also "bootm_size"
3032 environment variable. Address defined by "bootm_low" is
3033 also the base of the initial memory mapping for the Linux
3034 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ.
3036 bootm_size - Memory range available for image processing in the bootm
3037 command can be restricted. This variable is given as
3038 a hexadecimal number and defines the size of the region
3039 allowed for use by the bootm command. See also "bootm_low"
3040 environment variable.
3042 updatefile - Location of the software update file on a TFTP server, used
3043 by the automatic software update feature. Please refer to
3044 documentation in doc/README.update for more details.
3046 autoload - if set to "no" (any string beginning with 'n'),
3047 "bootp" will just load perform a lookup of the
3048 configuration from the BOOTP server, but not try to
3049 load any image using TFTP
3051 autostart - if set to "yes", an image loaded using the "bootp",
3052 "rarpboot", "tftpboot" or "diskboot" commands will
3053 be automatically started (by internally calling
3056 If set to "no", a standalone image passed to the
3057 "bootm" command will be copied to the load address
3058 (and eventually uncompressed), but NOT be started.
3059 This can be used to load and uncompress arbitrary
3062 i2cfast - (PPC405GP|PPC405EP only)
3063 if set to 'y' configures Linux I2C driver for fast
3064 mode (400kHZ). This environment variable is used in
3065 initialization code. So, for changes to be effective
3066 it must be saved and board must be reset.
3068 initrd_high - restrict positioning of initrd images:
3069 If this variable is not set, initrd images will be
3070 copied to the highest possible address in RAM; this
3071 is usually what you want since it allows for
3072 maximum initrd size. If for some reason you want to
3073 make sure that the initrd image is loaded below the
3074 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment
3075 variable to a value of "no" or "off" or "0".
3076 Alternatively, you can set it to a maximum upper
3077 address to use (U-Boot will still check that it
3078 does not overwrite the U-Boot stack and data).
3080 For instance, when you have a system with 16 MB
3081 RAM, and want to reserve 4 MB from use by Linux,
3082 you can do this by adding "mem=12M" to the value of
3083 the "bootargs" variable. However, now you must make
3084 sure that the initrd image is placed in the first
3085 12 MB as well - this can be done with
3087 setenv initrd_high 00c00000
3089 If you set initrd_high to 0xFFFFFFFF, this is an
3090 indication to U-Boot that all addresses are legal
3091 for the Linux kernel, including addresses in flash
3092 memory. In this case U-Boot will NOT COPY the
3093 ramdisk at all. This may be useful to reduce the
3094 boot time on your system, but requires that this
3095 feature is supported by your Linux kernel.
3097 ipaddr - IP address; needed for tftpboot command
3099 loadaddr - Default load address for commands like "bootp",
3100 "rarpboot", "tftpboot", "loadb" or "diskboot"
3102 loads_echo - see CONFIG_LOADS_ECHO
3104 serverip - TFTP server IP address; needed for tftpboot command
3106 bootretry - see CONFIG_BOOT_RETRY_TIME
3108 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
3110 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
3112 ethprime - When CONFIG_NET_MULTI is enabled controls which
3113 interface is used first.
3115 ethact - When CONFIG_NET_MULTI is enabled controls which
3116 interface is currently active. For example you
3117 can do the following
3119 => setenv ethact FEC ETHERNET
3120 => ping 192.168.0.1 # traffic sent on FEC ETHERNET
3121 => setenv ethact SCC ETHERNET
3122 => ping 10.0.0.1 # traffic sent on SCC ETHERNET
3124 ethrotate - When set to "no" U-Boot does not go through all
3125 available network interfaces.
3126 It just stays at the currently selected interface.
3128 netretry - When set to "no" each network operation will
3129 either succeed or fail without retrying.
3130 When set to "once" the network operation will
3131 fail when all the available network interfaces
3132 are tried once without success.
3133 Useful on scripts which control the retry operation
3136 npe_ucode - set load address for the NPE microcode
3138 tftpsrcport - If this is set, the value is used for TFTP's
3141 tftpdstport - If this is set, the value is used for TFTP's UDP
3142 destination port instead of the Well Know Port 69.
3144 tftpblocksize - Block size to use for TFTP transfers; if not set,
3145 we use the TFTP server's default block size
3147 tftptimeout - Retransmission timeout for TFTP packets (in milli-
3148 seconds, minimum value is 1000 = 1 second). Defines
3149 when a packet is considered to be lost so it has to
3150 be retransmitted. The default is 5000 = 5 seconds.
3151 Lowering this value may make downloads succeed
3152 faster in networks with high packet loss rates or
3153 with unreliable TFTP servers.
3155 vlan - When set to a value < 4095 the traffic over
3156 Ethernet is encapsulated/received over 802.1q
3159 The following environment variables may be used and automatically
3160 updated by the network boot commands ("bootp" and "rarpboot"),
3161 depending the information provided by your boot server:
3163 bootfile - see above
3164 dnsip - IP address of your Domain Name Server
3165 dnsip2 - IP address of your secondary Domain Name Server
3166 gatewayip - IP address of the Gateway (Router) to use
3167 hostname - Target hostname
3169 netmask - Subnet Mask
3170 rootpath - Pathname of the root filesystem on the NFS server
3171 serverip - see above
3174 There are two special Environment Variables:
3176 serial# - contains hardware identification information such
3177 as type string and/or serial number
3178 ethaddr - Ethernet address
3180 These variables can be set only once (usually during manufacturing of
3181 the board). U-Boot refuses to delete or overwrite these variables
3182 once they have been set once.
3185 Further special Environment Variables:
3187 ver - Contains the U-Boot version string as printed
3188 with the "version" command. This variable is
3189 readonly (see CONFIG_VERSION_VARIABLE).
3192 Please note that changes to some configuration parameters may take
3193 only effect after the next boot (yes, that's just like Windoze :-).
3196 Command Line Parsing:
3197 =====================
3199 There are two different command line parsers available with U-Boot:
3200 the old "simple" one, and the much more powerful "hush" shell:
3202 Old, simple command line parser:
3203 --------------------------------
3205 - supports environment variables (through setenv / saveenv commands)
3206 - several commands on one line, separated by ';'
3207 - variable substitution using "... ${name} ..." syntax
3208 - special characters ('$', ';') can be escaped by prefixing with '\',
3210 setenv bootcmd bootm \${address}
3211 - You can also escape text by enclosing in single apostrophes, for example:
3212 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
3217 - similar to Bourne shell, with control structures like
3218 if...then...else...fi, for...do...done; while...do...done,
3219 until...do...done, ...
3220 - supports environment ("global") variables (through setenv / saveenv
3221 commands) and local shell variables (through standard shell syntax
3222 "name=value"); only environment variables can be used with "run"
3228 (1) If a command line (or an environment variable executed by a "run"
3229 command) contains several commands separated by semicolon, and
3230 one of these commands fails, then the remaining commands will be
3233 (2) If you execute several variables with one call to run (i. e.
3234 calling run with a list of variables as arguments), any failing
3235 command will cause "run" to terminate, i. e. the remaining
3236 variables are not executed.
3238 Note for Redundant Ethernet Interfaces:
3239 =======================================
3241 Some boards come with redundant Ethernet interfaces; U-Boot supports
3242 such configurations and is capable of automatic selection of a
3243 "working" interface when needed. MAC assignment works as follows:
3245 Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
3246 MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
3247 "eth1addr" (=>eth1), "eth2addr", ...
3249 If the network interface stores some valid MAC address (for instance
3250 in SROM), this is used as default address if there is NO correspon-
3251 ding setting in the environment; if the corresponding environment
3252 variable is set, this overrides the settings in the card; that means:
3254 o If the SROM has a valid MAC address, and there is no address in the
3255 environment, the SROM's address is used.
3257 o If there is no valid address in the SROM, and a definition in the
3258 environment exists, then the value from the environment variable is
3261 o If both the SROM and the environment contain a MAC address, and
3262 both addresses are the same, this MAC address is used.
3264 o If both the SROM and the environment contain a MAC address, and the
3265 addresses differ, the value from the environment is used and a
3268 o If neither SROM nor the environment contain a MAC address, an error
3275 U-Boot is capable of booting (and performing other auxiliary operations on)
3276 images in two formats:
3278 New uImage format (FIT)
3279 -----------------------
3281 Flexible and powerful format based on Flattened Image Tree -- FIT (similar
3282 to Flattened Device Tree). It allows the use of images with multiple
3283 components (several kernels, ramdisks, etc.), with contents protected by
3284 SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory.
3290 Old image format is based on binary files which can be basically anything,
3291 preceded by a special header; see the definitions in include/image.h for
3292 details; basically, the header defines the following image properties:
3294 * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
3295 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
3296 LynxOS, pSOS, QNX, RTEMS, INTEGRITY;
3297 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS,
3299 * Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86,
3300 IA64, MIPS, NIOS, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
3301 Currently supported: ARM, AVR32, Intel x86, MIPS, NIOS, PowerPC).
3302 * Compression Type (uncompressed, gzip, bzip2)
3308 The header is marked by a special Magic Number, and both the header
3309 and the data portions of the image are secured against corruption by
3316 Although U-Boot should support any OS or standalone application
3317 easily, the main focus has always been on Linux during the design of
3320 U-Boot includes many features that so far have been part of some
3321 special "boot loader" code within the Linux kernel. Also, any
3322 "initrd" images to be used are no longer part of one big Linux image;
3323 instead, kernel and "initrd" are separate images. This implementation
3324 serves several purposes:
3326 - the same features can be used for other OS or standalone
3327 applications (for instance: using compressed images to reduce the
3328 Flash memory footprint)
3330 - it becomes much easier to port new Linux kernel versions because
3331 lots of low-level, hardware dependent stuff are done by U-Boot
3333 - the same Linux kernel image can now be used with different "initrd"
3334 images; of course this also means that different kernel images can
3335 be run with the same "initrd". This makes testing easier (you don't
3336 have to build a new "zImage.initrd" Linux image when you just
3337 change a file in your "initrd"). Also, a field-upgrade of the
3338 software is easier now.
3344 Porting Linux to U-Boot based systems:
3345 ---------------------------------------
3347 U-Boot cannot save you from doing all the necessary modifications to
3348 configure the Linux device drivers for use with your target hardware
3349 (no, we don't intend to provide a full virtual machine interface to
3352 But now you can ignore ALL boot loader code (in arch/ppc/mbxboot).
3354 Just make sure your machine specific header file (for instance
3355 include/asm-ppc/tqm8xx.h) includes the same definition of the Board
3356 Information structure as we define in include/asm-<arch>/u-boot.h,
3357 and make sure that your definition of IMAP_ADDR uses the same value
3358 as your U-Boot configuration in CONFIG_SYS_IMMR.
3361 Configuring the Linux kernel:
3362 -----------------------------
3364 No specific requirements for U-Boot. Make sure you have some root
3365 device (initial ramdisk, NFS) for your target system.
3368 Building a Linux Image:
3369 -----------------------
3371 With U-Boot, "normal" build targets like "zImage" or "bzImage" are
3372 not used. If you use recent kernel source, a new build target
3373 "uImage" will exist which automatically builds an image usable by
3374 U-Boot. Most older kernels also have support for a "pImage" target,
3375 which was introduced for our predecessor project PPCBoot and uses a
3376 100% compatible format.
3385 The "uImage" build target uses a special tool (in 'tools/mkimage') to
3386 encapsulate a compressed Linux kernel image with header information,
3387 CRC32 checksum etc. for use with U-Boot. This is what we are doing:
3389 * build a standard "vmlinux" kernel image (in ELF binary format):
3391 * convert the kernel into a raw binary image:
3393 ${CROSS_COMPILE}-objcopy -O binary \
3394 -R .note -R .comment \
3395 -S vmlinux linux.bin
3397 * compress the binary image:
3401 * package compressed binary image for U-Boot:
3403 mkimage -A ppc -O linux -T kernel -C gzip \
3404 -a 0 -e 0 -n "Linux Kernel Image" \
3405 -d linux.bin.gz uImage
3408 The "mkimage" tool can also be used to create ramdisk images for use
3409 with U-Boot, either separated from the Linux kernel image, or
3410 combined into one file. "mkimage" encapsulates the images with a 64
3411 byte header containing information about target architecture,
3412 operating system, image type, compression method, entry points, time
3413 stamp, CRC32 checksums, etc.
3415 "mkimage" can be called in two ways: to verify existing images and
3416 print the header information, or to build new images.
3418 In the first form (with "-l" option) mkimage lists the information
3419 contained in the header of an existing U-Boot image; this includes
3420 checksum verification:
3422 tools/mkimage -l image
3423 -l ==> list image header information
3425 The second form (with "-d" option) is used to build a U-Boot image
3426 from a "data file" which is used as image payload:
3428 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
3429 -n name -d data_file image
3430 -A ==> set architecture to 'arch'
3431 -O ==> set operating system to 'os'
3432 -T ==> set image type to 'type'
3433 -C ==> set compression type 'comp'
3434 -a ==> set load address to 'addr' (hex)
3435 -e ==> set entry point to 'ep' (hex)
3436 -n ==> set image name to 'name'
3437 -d ==> use image data from 'datafile'
3439 Right now, all Linux kernels for PowerPC systems use the same load
3440 address (0x00000000), but the entry point address depends on the
3443 - 2.2.x kernels have the entry point at 0x0000000C,
3444 - 2.3.x and later kernels have the entry point at 0x00000000.
3446 So a typical call to build a U-Boot image would read:
3448 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
3449 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
3450 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux.gz \
3451 > examples/uImage.TQM850L
3452 Image Name: 2.4.4 kernel for TQM850L
3453 Created: Wed Jul 19 02:34:59 2000
3454 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3455 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
3456 Load Address: 0x00000000
3457 Entry Point: 0x00000000
3459 To verify the contents of the image (or check for corruption):
3461 -> tools/mkimage -l examples/uImage.TQM850L
3462 Image Name: 2.4.4 kernel for TQM850L
3463 Created: Wed Jul 19 02:34:59 2000
3464 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3465 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
3466 Load Address: 0x00000000
3467 Entry Point: 0x00000000
3469 NOTE: for embedded systems where boot time is critical you can trade
3470 speed for memory and install an UNCOMPRESSED image instead: this
3471 needs more space in Flash, but boots much faster since it does not
3472 need to be uncompressed:
3474 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux.gz
3475 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
3476 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
3477 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux \
3478 > examples/uImage.TQM850L-uncompressed
3479 Image Name: 2.4.4 kernel for TQM850L
3480 Created: Wed Jul 19 02:34:59 2000
3481 Image Type: PowerPC Linux Kernel Image (uncompressed)
3482 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
3483 Load Address: 0x00000000
3484 Entry Point: 0x00000000
3487 Similar you can build U-Boot images from a 'ramdisk.image.gz' file
3488 when your kernel is intended to use an initial ramdisk:
3490 -> tools/mkimage -n 'Simple Ramdisk Image' \
3491 > -A ppc -O linux -T ramdisk -C gzip \
3492 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
3493 Image Name: Simple Ramdisk Image
3494 Created: Wed Jan 12 14:01:50 2000
3495 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
3496 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
3497 Load Address: 0x00000000
3498 Entry Point: 0x00000000
3501 Installing a Linux Image:
3502 -------------------------
3504 To downloading a U-Boot image over the serial (console) interface,
3505 you must convert the image to S-Record format:
3507 objcopy -I binary -O srec examples/image examples/image.srec
3509 The 'objcopy' does not understand the information in the U-Boot
3510 image header, so the resulting S-Record file will be relative to
3511 address 0x00000000. To load it to a given address, you need to
3512 specify the target address as 'offset' parameter with the 'loads'
3515 Example: install the image to address 0x40100000 (which on the
3516 TQM8xxL is in the first Flash bank):
3518 => erase 40100000 401FFFFF
3524 ## Ready for S-Record download ...
3525 ~>examples/image.srec
3526 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
3528 15989 15990 15991 15992
3529 [file transfer complete]
3531 ## Start Addr = 0x00000000
3534 You can check the success of the download using the 'iminfo' command;
3535 this includes a checksum verification so you can be sure no data
3536 corruption happened:
3540 ## Checking Image at 40100000 ...
3541 Image Name: 2.2.13 for initrd on TQM850L
3542 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3543 Data Size: 335725 Bytes = 327 kB = 0 MB
3544 Load Address: 00000000
3545 Entry Point: 0000000c
3546 Verifying Checksum ... OK
3552 The "bootm" command is used to boot an application that is stored in
3553 memory (RAM or Flash). In case of a Linux kernel image, the contents
3554 of the "bootargs" environment variable is passed to the kernel as
3555 parameters. You can check and modify this variable using the
3556 "printenv" and "setenv" commands:
3559 => printenv bootargs
3560 bootargs=root=/dev/ram
3562 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
3564 => printenv bootargs
3565 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
3568 ## Booting Linux kernel at 40020000 ...
3569 Image Name: 2.2.13 for NFS on TQM850L
3570 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3571 Data Size: 381681 Bytes = 372 kB = 0 MB
3572 Load Address: 00000000
3573 Entry Point: 0000000c
3574 Verifying Checksum ... OK
3575 Uncompressing Kernel Image ... OK
3576 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
3577 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
3578 time_init: decrementer frequency = 187500000/60
3579 Calibrating delay loop... 49.77 BogoMIPS
3580 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
3583 If you want to boot a Linux kernel with initial RAM disk, you pass
3584 the memory addresses of both the kernel and the initrd image (PPBCOOT
3585 format!) to the "bootm" command:
3587 => imi 40100000 40200000
3589 ## Checking Image at 40100000 ...
3590 Image Name: 2.2.13 for initrd on TQM850L
3591 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3592 Data Size: 335725 Bytes = 327 kB = 0 MB
3593 Load Address: 00000000
3594 Entry Point: 0000000c
3595 Verifying Checksum ... OK
3597 ## Checking Image at 40200000 ...
3598 Image Name: Simple Ramdisk Image
3599 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
3600 Data Size: 566530 Bytes = 553 kB = 0 MB
3601 Load Address: 00000000
3602 Entry Point: 00000000
3603 Verifying Checksum ... OK
3605 => bootm 40100000 40200000
3606 ## Booting Linux kernel at 40100000 ...
3607 Image Name: 2.2.13 for initrd on TQM850L
3608 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3609 Data Size: 335725 Bytes = 327 kB = 0 MB
3610 Load Address: 00000000
3611 Entry Point: 0000000c
3612 Verifying Checksum ... OK
3613 Uncompressing Kernel Image ... OK
3614 ## Loading RAMDisk Image at 40200000 ...
3615 Image Name: Simple Ramdisk Image
3616 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
3617 Data Size: 566530 Bytes = 553 kB = 0 MB
3618 Load Address: 00000000
3619 Entry Point: 00000000
3620 Verifying Checksum ... OK
3621 Loading Ramdisk ... OK
3622 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
3623 Boot arguments: root=/dev/ram
3624 time_init: decrementer frequency = 187500000/60
3625 Calibrating delay loop... 49.77 BogoMIPS
3627 RAMDISK: Compressed image found at block 0
3628 VFS: Mounted root (ext2 filesystem).
3632 Boot Linux and pass a flat device tree:
3635 First, U-Boot must be compiled with the appropriate defines. See the section
3636 titled "Linux Kernel Interface" above for a more in depth explanation. The
3637 following is an example of how to start a kernel and pass an updated
3643 oft=oftrees/mpc8540ads.dtb
3644 => tftp $oftaddr $oft
3645 Speed: 1000, full duplex
3647 TFTP from server 192.168.1.1; our IP address is 192.168.1.101
3648 Filename 'oftrees/mpc8540ads.dtb'.
3649 Load address: 0x300000
3652 Bytes transferred = 4106 (100a hex)
3653 => tftp $loadaddr $bootfile
3654 Speed: 1000, full duplex
3656 TFTP from server 192.168.1.1; our IP address is 192.168.1.2
3658 Load address: 0x200000
3659 Loading:############
3661 Bytes transferred = 1029407 (fb51f hex)
3666 => bootm $loadaddr - $oftaddr
3667 ## Booting image at 00200000 ...
3668 Image Name: Linux-2.6.17-dirty
3669 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3670 Data Size: 1029343 Bytes = 1005.2 kB
3671 Load Address: 00000000
3672 Entry Point: 00000000
3673 Verifying Checksum ... OK
3674 Uncompressing Kernel Image ... OK
3675 Booting using flat device tree at 0x300000
3676 Using MPC85xx ADS machine description
3677 Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb
3681 More About U-Boot Image Types:
3682 ------------------------------
3684 U-Boot supports the following image types:
3686 "Standalone Programs" are directly runnable in the environment
3687 provided by U-Boot; it is expected that (if they behave
3688 well) you can continue to work in U-Boot after return from
3689 the Standalone Program.
3690 "OS Kernel Images" are usually images of some Embedded OS which
3691 will take over control completely. Usually these programs
3692 will install their own set of exception handlers, device
3693 drivers, set up the MMU, etc. - this means, that you cannot
3694 expect to re-enter U-Boot except by resetting the CPU.
3695 "RAMDisk Images" are more or less just data blocks, and their
3696 parameters (address, size) are passed to an OS kernel that is
3698 "Multi-File Images" contain several images, typically an OS
3699 (Linux) kernel image and one or more data images like
3700 RAMDisks. This construct is useful for instance when you want
3701 to boot over the network using BOOTP etc., where the boot
3702 server provides just a single image file, but you want to get
3703 for instance an OS kernel and a RAMDisk image.
3705 "Multi-File Images" start with a list of image sizes, each
3706 image size (in bytes) specified by an "uint32_t" in network
3707 byte order. This list is terminated by an "(uint32_t)0".
3708 Immediately after the terminating 0 follow the images, one by
3709 one, all aligned on "uint32_t" boundaries (size rounded up to
3710 a multiple of 4 bytes).
3712 "Firmware Images" are binary images containing firmware (like
3713 U-Boot or FPGA images) which usually will be programmed to
3716 "Script files" are command sequences that will be executed by
3717 U-Boot's command interpreter; this feature is especially
3718 useful when you configure U-Boot to use a real shell (hush)
3719 as command interpreter.
3725 One of the features of U-Boot is that you can dynamically load and
3726 run "standalone" applications, which can use some resources of
3727 U-Boot like console I/O functions or interrupt services.
3729 Two simple examples are included with the sources:
3734 'examples/hello_world.c' contains a small "Hello World" Demo
3735 application; it is automatically compiled when you build U-Boot.
3736 It's configured to run at address 0x00040004, so you can play with it
3740 ## Ready for S-Record download ...
3741 ~>examples/hello_world.srec
3742 1 2 3 4 5 6 7 8 9 10 11 ...
3743 [file transfer complete]
3745 ## Start Addr = 0x00040004
3747 => go 40004 Hello World! This is a test.
3748 ## Starting application at 0x00040004 ...
3759 Hit any key to exit ...
3761 ## Application terminated, rc = 0x0
3763 Another example, which demonstrates how to register a CPM interrupt
3764 handler with the U-Boot code, can be found in 'examples/timer.c'.
3765 Here, a CPM timer is set up to generate an interrupt every second.
3766 The interrupt service routine is trivial, just printing a '.'
3767 character, but this is just a demo program. The application can be
3768 controlled by the following keys:
3770 ? - print current values og the CPM Timer registers
3771 b - enable interrupts and start timer
3772 e - stop timer and disable interrupts
3773 q - quit application
3776 ## Ready for S-Record download ...
3777 ~>examples/timer.srec
3778 1 2 3 4 5 6 7 8 9 10 11 ...
3779 [file transfer complete]
3781 ## Start Addr = 0x00040004
3784 ## Starting application at 0x00040004 ...
3787 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
3790 [q, b, e, ?] Set interval 1000000 us
3793 [q, b, e, ?] ........
3794 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
3797 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
3800 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
3803 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
3805 [q, b, e, ?] ...Stopping timer
3807 [q, b, e, ?] ## Application terminated, rc = 0x0
3813 Over time, many people have reported problems when trying to use the
3814 "minicom" terminal emulation program for serial download. I (wd)
3815 consider minicom to be broken, and recommend not to use it. Under
3816 Unix, I recommend to use C-Kermit for general purpose use (and
3817 especially for kermit binary protocol download ("loadb" command), and
3818 use "cu" for S-Record download ("loads" command).
3820 Nevertheless, if you absolutely want to use it try adding this
3821 configuration to your "File transfer protocols" section:
3823 Name Program Name U/D FullScr IO-Red. Multi
3824 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
3825 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
3831 Starting at version 0.9.2, U-Boot supports NetBSD both as host
3832 (build U-Boot) and target system (boots NetBSD/mpc8xx).
3834 Building requires a cross environment; it is known to work on
3835 NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
3836 need gmake since the Makefiles are not compatible with BSD make).
3837 Note that the cross-powerpc package does not install include files;
3838 attempting to build U-Boot will fail because <machine/ansi.h> is
3839 missing. This file has to be installed and patched manually:
3841 # cd /usr/pkg/cross/powerpc-netbsd/include
3843 # ln -s powerpc machine
3844 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
3845 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
3847 Native builds *don't* work due to incompatibilities between native
3848 and U-Boot include files.
3850 Booting assumes that (the first part of) the image booted is a
3851 stage-2 loader which in turn loads and then invokes the kernel
3852 proper. Loader sources will eventually appear in the NetBSD source
3853 tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
3854 meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz
3857 Implementation Internals:
3858 =========================
3860 The following is not intended to be a complete description of every
3861 implementation detail. However, it should help to understand the
3862 inner workings of U-Boot and make it easier to port it to custom
3866 Initial Stack, Global Data:
3867 ---------------------------
3869 The implementation of U-Boot is complicated by the fact that U-Boot
3870 starts running out of ROM (flash memory), usually without access to
3871 system RAM (because the memory controller is not initialized yet).
3872 This means that we don't have writable Data or BSS segments, and BSS
3873 is not initialized as zero. To be able to get a C environment working
3874 at all, we have to allocate at least a minimal stack. Implementation
3875 options for this are defined and restricted by the CPU used: Some CPU
3876 models provide on-chip memory (like the IMMR area on MPC8xx and
3877 MPC826x processors), on others (parts of) the data cache can be
3878 locked as (mis-) used as memory, etc.
3880 Chris Hallinan posted a good summary of these issues to the
3881 U-Boot mailing list:
3883 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
3884 From: "Chris Hallinan" <clh@net1plus.com>
3885 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
3888 Correct me if I'm wrong, folks, but the way I understand it
3889 is this: Using DCACHE as initial RAM for Stack, etc, does not
3890 require any physical RAM backing up the cache. The cleverness
3891 is that the cache is being used as a temporary supply of
3892 necessary storage before the SDRAM controller is setup. It's
3893 beyond the scope of this list to explain the details, but you
3894 can see how this works by studying the cache architecture and
3895 operation in the architecture and processor-specific manuals.
3897 OCM is On Chip Memory, which I believe the 405GP has 4K. It
3898 is another option for the system designer to use as an
3899 initial stack/RAM area prior to SDRAM being available. Either
3900 option should work for you. Using CS 4 should be fine if your
3901 board designers haven't used it for something that would
3902 cause you grief during the initial boot! It is frequently not
3905 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere
3906 with your processor/board/system design. The default value
3907 you will find in any recent u-boot distribution in
3908 walnut.h should work for you. I'd set it to a value larger
3909 than your SDRAM module. If you have a 64MB SDRAM module, set
3910 it above 400_0000. Just make sure your board has no resources
3911 that are supposed to respond to that address! That code in
3912 start.S has been around a while and should work as is when
3913 you get the config right.
3918 It is essential to remember this, since it has some impact on the C
3919 code for the initialization procedures:
3921 * Initialized global data (data segment) is read-only. Do not attempt
3924 * Do not use any uninitialized global data (or implicitely initialized
3925 as zero data - BSS segment) at all - this is undefined, initiali-
3926 zation is performed later (when relocating to RAM).
3928 * Stack space is very limited. Avoid big data buffers or things like
3931 Having only the stack as writable memory limits means we cannot use
3932 normal global data to share information beween the code. But it
3933 turned out that the implementation of U-Boot can be greatly
3934 simplified by making a global data structure (gd_t) available to all
3935 functions. We could pass a pointer to this data as argument to _all_
3936 functions, but this would bloat the code. Instead we use a feature of
3937 the GCC compiler (Global Register Variables) to share the data: we
3938 place a pointer (gd) to the global data into a register which we
3939 reserve for this purpose.
3941 When choosing a register for such a purpose we are restricted by the
3942 relevant (E)ABI specifications for the current architecture, and by
3943 GCC's implementation.
3945 For PowerPC, the following registers have specific use:
3947 R2: reserved for system use
3948 R3-R4: parameter passing and return values
3949 R5-R10: parameter passing
3950 R13: small data area pointer
3954 (U-Boot also uses R12 as internal GOT pointer. r12
3955 is a volatile register so r12 needs to be reset when
3956 going back and forth between asm and C)
3958 ==> U-Boot will use R2 to hold a pointer to the global data
3960 Note: on PPC, we could use a static initializer (since the
3961 address of the global data structure is known at compile time),
3962 but it turned out that reserving a register results in somewhat
3963 smaller code - although the code savings are not that big (on
3964 average for all boards 752 bytes for the whole U-Boot image,
3965 624 text + 127 data).
3967 On Blackfin, the normal C ABI (except for P3) is followed as documented here:
3968 http://docs.blackfin.uclinux.org/doku.php?id=application_binary_interface
3970 ==> U-Boot will use P3 to hold a pointer to the global data
3972 On ARM, the following registers are used:
3974 R0: function argument word/integer result
3975 R1-R3: function argument word
3977 R10: stack limit (used only if stack checking if enabled)
3978 R11: argument (frame) pointer
3979 R12: temporary workspace
3982 R15: program counter
3984 ==> U-Boot will use R8 to hold a pointer to the global data
3986 NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope,
3987 or current versions of GCC may "optimize" the code too much.
3992 U-Boot runs in system state and uses physical addresses, i.e. the
3993 MMU is not used either for address mapping nor for memory protection.
3995 The available memory is mapped to fixed addresses using the memory
3996 controller. In this process, a contiguous block is formed for each
3997 memory type (Flash, SDRAM, SRAM), even when it consists of several
3998 physical memory banks.
4000 U-Boot is installed in the first 128 kB of the first Flash bank (on
4001 TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
4002 booting and sizing and initializing DRAM, the code relocates itself
4003 to the upper end of DRAM. Immediately below the U-Boot code some
4004 memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN
4005 configuration setting]. Below that, a structure with global Board
4006 Info data is placed, followed by the stack (growing downward).
4008 Additionally, some exception handler code is copied to the low 8 kB
4009 of DRAM (0x00000000 ... 0x00001FFF).
4011 So a typical memory configuration with 16 MB of DRAM could look like
4014 0x0000 0000 Exception Vector code
4017 0x0000 2000 Free for Application Use
4023 0x00FB FF20 Monitor Stack (Growing downward)
4024 0x00FB FFAC Board Info Data and permanent copy of global data
4025 0x00FC 0000 Malloc Arena
4028 0x00FE 0000 RAM Copy of Monitor Code
4029 ... eventually: LCD or video framebuffer
4030 ... eventually: pRAM (Protected RAM - unchanged by reset)
4031 0x00FF FFFF [End of RAM]
4034 System Initialization:
4035 ----------------------
4037 In the reset configuration, U-Boot starts at the reset entry point
4038 (on most PowerPC systems at address 0x00000100). Because of the reset
4039 configuration for CS0# this is a mirror of the onboard Flash memory.
4040 To be able to re-map memory U-Boot then jumps to its link address.
4041 To be able to implement the initialization code in C, a (small!)
4042 initial stack is set up in the internal Dual Ported RAM (in case CPUs
4043 which provide such a feature like MPC8xx or MPC8260), or in a locked
4044 part of the data cache. After that, U-Boot initializes the CPU core,
4045 the caches and the SIU.
4047 Next, all (potentially) available memory banks are mapped using a
4048 preliminary mapping. For example, we put them on 512 MB boundaries
4049 (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
4050 on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
4051 programmed for SDRAM access. Using the temporary configuration, a
4052 simple memory test is run that determines the size of the SDRAM
4055 When there is more than one SDRAM bank, and the banks are of
4056 different size, the largest is mapped first. For equal size, the first
4057 bank (CS2#) is mapped first. The first mapping is always for address
4058 0x00000000, with any additional banks following immediately to create
4059 contiguous memory starting from 0.
4061 Then, the monitor installs itself at the upper end of the SDRAM area
4062 and allocates memory for use by malloc() and for the global Board
4063 Info data; also, the exception vector code is copied to the low RAM
4064 pages, and the final stack is set up.
4066 Only after this relocation will you have a "normal" C environment;
4067 until that you are restricted in several ways, mostly because you are
4068 running from ROM, and because the code will have to be relocated to a
4072 U-Boot Porting Guide:
4073 ----------------------
4075 [Based on messages by Jerry Van Baren in the U-Boot-Users mailing
4079 int main(int argc, char *argv[])
4081 sighandler_t no_more_time;
4083 signal(SIGALRM, no_more_time);
4084 alarm(PROJECT_DEADLINE - toSec (3 * WEEK));
4086 if (available_money > available_manpower) {
4087 Pay consultant to port U-Boot;
4091 Download latest U-Boot source;
4093 Subscribe to u-boot mailing list;
4096 email("Hi, I am new to U-Boot, how do I get started?");
4099 Read the README file in the top level directory;
4100 Read http://www.denx.de/twiki/bin/view/DULG/Manual;
4101 Read applicable doc/*.README;
4102 Read the source, Luke;
4103 /* find . -name "*.[chS]" | xargs grep -i <keyword> */
4106 if (available_money > toLocalCurrency ($2500))
4109 Add a lot of aggravation and time;
4111 if (a similar board exists) { /* hopefully... */
4112 cp -a board/<similar> board/<myboard>
4113 cp include/configs/<similar>.h include/configs/<myboard>.h
4115 Create your own board support subdirectory;
4116 Create your own board include/configs/<myboard>.h file;
4118 Edit new board/<myboard> files
4119 Edit new include/configs/<myboard>.h
4124 Add / modify source code;
4128 email("Hi, I am having problems...");
4130 Send patch file to the U-Boot email list;
4131 if (reasonable critiques)
4132 Incorporate improvements from email list code review;
4134 Defend code as written;
4140 void no_more_time (int sig)
4149 All contributions to U-Boot should conform to the Linux kernel
4150 coding style; see the file "Documentation/CodingStyle" and the script
4151 "scripts/Lindent" in your Linux kernel source directory. In sources
4152 originating from U-Boot a style corresponding to "Lindent -pcs" (adding
4153 spaces before parameters to function calls) is actually used.
4155 Source files originating from a different project (for example the
4156 MTD subsystem) are generally exempt from these guidelines and are not
4157 reformated to ease subsequent migration to newer versions of those
4160 Please note that U-Boot is implemented in C (and to some small parts in
4161 Assembler); no C++ is used, so please do not use C++ style comments (//)
4164 Please also stick to the following formatting rules:
4165 - remove any trailing white space
4166 - use TAB characters for indentation, not spaces
4167 - make sure NOT to use DOS '\r\n' line feeds
4168 - do not add more than 2 empty lines to source files
4169 - do not add trailing empty lines to source files
4171 Submissions which do not conform to the standards may be returned
4172 with a request to reformat the changes.
4178 Since the number of patches for U-Boot is growing, we need to
4179 establish some rules. Submissions which do not conform to these rules
4180 may be rejected, even when they contain important and valuable stuff.
4182 Please see http://www.denx.de/wiki/U-Boot/Patches for details.
4184 Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>;
4185 see http://lists.denx.de/mailman/listinfo/u-boot
4187 When you send a patch, please include the following information with
4190 * For bug fixes: a description of the bug and how your patch fixes
4191 this bug. Please try to include a way of demonstrating that the
4192 patch actually fixes something.
4194 * For new features: a description of the feature and your
4197 * A CHANGELOG entry as plaintext (separate from the patch)
4199 * For major contributions, your entry to the CREDITS file
4201 * When you add support for a new board, don't forget to add this
4202 board to the MAKEALL script, too.
4204 * If your patch adds new configuration options, don't forget to
4205 document these in the README file.
4207 * The patch itself. If you are using git (which is *strongly*
4208 recommended) you can easily generate the patch using the
4209 "git-format-patch". If you then use "git-send-email" to send it to
4210 the U-Boot mailing list, you will avoid most of the common problems
4211 with some other mail clients.
4213 If you cannot use git, use "diff -purN OLD NEW". If your version of
4214 diff does not support these options, then get the latest version of
4217 The current directory when running this command shall be the parent
4218 directory of the U-Boot source tree (i. e. please make sure that
4219 your patch includes sufficient directory information for the
4222 We prefer patches as plain text. MIME attachments are discouraged,
4223 and compressed attachments must not be used.
4225 * If one logical set of modifications affects or creates several
4226 files, all these changes shall be submitted in a SINGLE patch file.
4228 * Changesets that contain different, unrelated modifications shall be
4229 submitted as SEPARATE patches, one patch per changeset.
4234 * Before sending the patch, run the MAKEALL script on your patched
4235 source tree and make sure that no errors or warnings are reported
4236 for any of the boards.
4238 * Keep your modifications to the necessary minimum: A patch
4239 containing several unrelated changes or arbitrary reformats will be
4240 returned with a request to re-formatting / split it.
4242 * If you modify existing code, make sure that your new code does not
4243 add to the memory footprint of the code ;-) Small is beautiful!
4244 When adding new features, these should compile conditionally only
4245 (using #ifdef), and the resulting code with the new feature
4246 disabled must not need more memory than the old code without your
4249 * Remember that there is a size limit of 100 kB per message on the
4250 u-boot mailing list. Bigger patches will be moderated. If they are
4251 reasonable and not too big, they will be acknowledged. But patches
4252 bigger than the size limit should be avoided.
projects / kernel / u-boot.git / blob