2 # (C) Copyright 2000 - 2012
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 Starting with the release in October 2008, the names of the releases
130 were changed from numerical release numbers without deeper meaning
131 into a time stamp based numbering. Regular releases are identified by
132 names consisting of the calendar year and month of the release date.
133 Additional fields (if present) indicate release candidates or bug fix
134 releases in "stable" maintenance trees.
137 U-Boot v2009.11 - Release November 2009
138 U-Boot v2009.11.1 - Release 1 in version November 2009 stable tree
139 U-Boot v2010.09-rc1 - Release candiate 1 for September 2010 release
145 /arch Architecture specific files
146 /arm Files generic to ARM architecture
147 /cpu CPU specific files
148 /arm720t Files specific to ARM 720 CPUs
149 /arm920t Files specific to ARM 920 CPUs
150 /at91 Files specific to Atmel AT91RM9200 CPU
151 /imx Files specific to Freescale MC9328 i.MX CPUs
152 /s3c24x0 Files specific to Samsung S3C24X0 CPUs
153 /arm925t Files specific to ARM 925 CPUs
154 /arm926ejs Files specific to ARM 926 CPUs
155 /arm1136 Files specific to ARM 1136 CPUs
156 /ixp Files specific to Intel XScale IXP CPUs
157 /pxa Files specific to Intel XScale PXA CPUs
158 /s3c44b0 Files specific to Samsung S3C44B0 CPUs
159 /sa1100 Files specific to Intel StrongARM SA1100 CPUs
160 /lib Architecture specific library files
161 /avr32 Files generic to AVR32 architecture
162 /cpu CPU specific files
163 /lib Architecture specific library files
164 /blackfin Files generic to Analog Devices Blackfin architecture
165 /cpu CPU specific files
166 /lib Architecture specific library files
167 /x86 Files generic to x86 architecture
168 /cpu CPU specific files
169 /lib Architecture specific library files
170 /m68k Files generic to m68k architecture
171 /cpu CPU specific files
172 /mcf52x2 Files specific to Freescale ColdFire MCF52x2 CPUs
173 /mcf5227x Files specific to Freescale ColdFire MCF5227x CPUs
174 /mcf532x Files specific to Freescale ColdFire MCF5329 CPUs
175 /mcf5445x Files specific to Freescale ColdFire MCF5445x CPUs
176 /mcf547x_8x Files specific to Freescale ColdFire MCF547x_8x CPUs
177 /lib Architecture specific library files
178 /microblaze Files generic to microblaze architecture
179 /cpu CPU specific files
180 /lib Architecture specific library files
181 /mips Files generic to MIPS architecture
182 /cpu CPU specific files
183 /mips32 Files specific to MIPS32 CPUs
184 /xburst Files specific to Ingenic XBurst CPUs
185 /lib Architecture specific library files
186 /nds32 Files generic to NDS32 architecture
187 /cpu CPU specific files
188 /n1213 Files specific to Andes Technology N1213 CPUs
189 /lib Architecture specific library files
190 /nios2 Files generic to Altera NIOS2 architecture
191 /cpu CPU specific files
192 /lib Architecture specific library files
193 /powerpc Files generic to PowerPC architecture
194 /cpu CPU specific files
195 /74xx_7xx Files specific to Freescale MPC74xx and 7xx CPUs
196 /mpc5xx Files specific to Freescale MPC5xx CPUs
197 /mpc5xxx Files specific to Freescale MPC5xxx CPUs
198 /mpc8xx Files specific to Freescale MPC8xx CPUs
199 /mpc8220 Files specific to Freescale MPC8220 CPUs
200 /mpc824x Files specific to Freescale MPC824x CPUs
201 /mpc8260 Files specific to Freescale MPC8260 CPUs
202 /mpc85xx Files specific to Freescale MPC85xx CPUs
203 /ppc4xx Files specific to AMCC PowerPC 4xx CPUs
204 /lib Architecture specific library files
205 /sh Files generic to SH architecture
206 /cpu CPU specific files
207 /sh2 Files specific to sh2 CPUs
208 /sh3 Files specific to sh3 CPUs
209 /sh4 Files specific to sh4 CPUs
210 /lib Architecture specific library files
211 /sparc Files generic to SPARC architecture
212 /cpu CPU specific files
213 /leon2 Files specific to Gaisler LEON2 SPARC CPU
214 /leon3 Files specific to Gaisler LEON3 SPARC CPU
215 /lib Architecture specific library files
216 /api Machine/arch independent API for external apps
217 /board Board dependent files
218 /common Misc architecture independent functions
219 /disk Code for disk drive partition handling
220 /doc Documentation (don't expect too much)
221 /drivers Commonly used device drivers
222 /examples Example code for standalone applications, etc.
223 /fs Filesystem code (cramfs, ext2, jffs2, etc.)
224 /include Header Files
225 /lib Files generic to all architectures
226 /libfdt Library files to support flattened device trees
227 /lzma Library files to support LZMA decompression
228 /lzo Library files to support LZO decompression
230 /post Power On Self Test
231 /rtc Real Time Clock drivers
232 /tools Tools to build S-Record or U-Boot images, etc.
234 Software Configuration:
235 =======================
237 Configuration is usually done using C preprocessor defines; the
238 rationale behind that is to avoid dead code whenever possible.
240 There are two classes of configuration variables:
242 * Configuration _OPTIONS_:
243 These are selectable by the user and have names beginning with
246 * Configuration _SETTINGS_:
247 These depend on the hardware etc. and should not be meddled with if
248 you don't know what you're doing; they have names beginning with
251 Later we will add a configuration tool - probably similar to or even
252 identical to what's used for the Linux kernel. Right now, we have to
253 do the configuration by hand, which means creating some symbolic
254 links and editing some configuration files. We use the TQM8xxL boards
258 Selection of Processor Architecture and Board Type:
259 ---------------------------------------------------
261 For all supported boards there are ready-to-use default
262 configurations available; just type "make <board_name>_config".
264 Example: For a TQM823L module type:
269 For the Cogent platform, you need to specify the CPU type as well;
270 e.g. "make cogent_mpc8xx_config". And also configure the cogent
271 directory according to the instructions in cogent/README.
274 Configuration Options:
275 ----------------------
277 Configuration depends on the combination of board and CPU type; all
278 such information is kept in a configuration file
279 "include/configs/<board_name>.h".
281 Example: For a TQM823L module, all configuration settings are in
282 "include/configs/TQM823L.h".
285 Many of the options are named exactly as the corresponding Linux
286 kernel configuration options. The intention is to make it easier to
287 build a config tool - later.
290 The following options need to be configured:
292 - CPU Type: Define exactly one, e.g. CONFIG_MPC85XX.
294 - Board Type: Define exactly one, e.g. CONFIG_MPC8540ADS.
296 - CPU Daughterboard Type: (if CONFIG_ATSTK1000 is defined)
297 Define exactly one, e.g. CONFIG_ATSTK1002
299 - CPU Module Type: (if CONFIG_COGENT is defined)
300 Define exactly one of
302 --- FIXME --- not tested yet:
303 CONFIG_CMA286_60, CONFIG_CMA286_21, CONFIG_CMA286_60P,
304 CONFIG_CMA287_23, CONFIG_CMA287_50
306 - Motherboard Type: (if CONFIG_COGENT is defined)
307 Define exactly one of
308 CONFIG_CMA101, CONFIG_CMA102
310 - Motherboard I/O Modules: (if CONFIG_COGENT is defined)
311 Define one or more of
314 - Motherboard Options: (if CONFIG_CMA101 or CONFIG_CMA102 are defined)
315 Define one or more of
316 CONFIG_LCD_HEARTBEAT - update a character position on
317 the LCD display every second with
320 - Board flavour: (if CONFIG_MPC8260ADS is defined)
323 CONFIG_SYS_8260ADS - original MPC8260ADS
324 CONFIG_SYS_8266ADS - MPC8266ADS
325 CONFIG_SYS_PQ2FADS - PQ2FADS-ZU or PQ2FADS-VR
326 CONFIG_SYS_8272ADS - MPC8272ADS
328 - Marvell Family Member
329 CONFIG_SYS_MVFS - define it if you want to enable
330 multiple fs option at one time
331 for marvell soc family
333 - MPC824X Family Member (if CONFIG_MPC824X is defined)
334 Define exactly one of
335 CONFIG_MPC8240, CONFIG_MPC8245
337 - 8xx CPU Options: (if using an MPC8xx CPU)
338 CONFIG_8xx_GCLK_FREQ - deprecated: CPU clock if
339 get_gclk_freq() cannot work
340 e.g. if there is no 32KHz
341 reference PIT/RTC clock
342 CONFIG_8xx_OSCLK - PLL input clock (either EXTCLK
345 - 859/866/885 CPU options: (if using a MPC859 or MPC866 or MPC885 CPU):
346 CONFIG_SYS_8xx_CPUCLK_MIN
347 CONFIG_SYS_8xx_CPUCLK_MAX
348 CONFIG_8xx_CPUCLK_DEFAULT
349 See doc/README.MPC866
351 CONFIG_SYS_MEASURE_CPUCLK
353 Define this to measure the actual CPU clock instead
354 of relying on the correctness of the configured
355 values. Mostly useful for board bringup to make sure
356 the PLL is locked at the intended frequency. Note
357 that this requires a (stable) reference clock (32 kHz
358 RTC clock or CONFIG_SYS_8XX_XIN)
360 CONFIG_SYS_DELAYED_ICACHE
362 Define this option if you want to enable the
363 ICache only when Code runs from RAM.
366 CONFIG_SYS_FSL_TBCLK_DIV
368 Defines the core time base clock divider ratio compared to the
369 system clock. On most PQ3 devices this is 8, on newer QorIQ
370 devices it can be 16 or 32. The ratio varies from SoC to Soc.
372 CONFIG_SYS_FSL_PCIE_COMPAT
374 Defines the string to utilize when trying to match PCIe device
375 tree nodes for the given platform.
377 CONFIG_SYS_PPC_E500_DEBUG_TLB
379 Enables a temporary TLB entry to be used during boot to work
380 around limitations in e500v1 and e500v2 external debugger
381 support. This reduces the portions of the boot code where
382 breakpoints and single stepping do not work. The value of this
383 symbol should be set to the TLB1 entry to be used for this
386 - Generic CPU options:
387 CONFIG_SYS_BIG_ENDIAN, CONFIG_SYS_LITTLE_ENDIAN
389 Defines the endianess of the CPU. Implementation of those
390 values is arch specific.
392 - Intel Monahans options:
393 CONFIG_SYS_MONAHANS_RUN_MODE_OSC_RATIO
395 Defines the Monahans run mode to oscillator
396 ratio. Valid values are 8, 16, 24, 31. The core
397 frequency is this value multiplied by 13 MHz.
399 CONFIG_SYS_MONAHANS_TURBO_RUN_MODE_RATIO
401 Defines the Monahans turbo mode to oscillator
402 ratio. Valid values are 1 (default if undefined) and
403 2. The core frequency as calculated above is multiplied
407 CONFIG_SYS_INIT_SP_OFFSET
409 Offset relative to CONFIG_SYS_SDRAM_BASE for initial stack
410 pointer. This is needed for the temporary stack before
413 CONFIG_SYS_MIPS_CACHE_MODE
415 Cache operation mode for the MIPS CPU.
416 See also arch/mips/include/asm/mipsregs.h.
418 CONF_CM_CACHABLE_NO_WA
421 CONF_CM_CACHABLE_NONCOHERENT
425 CONF_CM_CACHABLE_ACCELERATED
427 CONFIG_SYS_XWAY_EBU_BOOTCFG
429 Special option for Lantiq XWAY SoCs for booting from NOR flash.
430 See also arch/mips/cpu/mips32/start.S.
432 CONFIG_XWAY_SWAP_BYTES
434 Enable compilation of tools/xway-swap-bytes needed for Lantiq
435 XWAY SoCs for booting from NOR flash. The U-Boot image needs to
436 be swapped if a flash programmer is used.
439 CONFIG_SYS_EXCEPTION_VECTORS_HIGH
441 Select high exception vectors of the ARM core, e.g., do not
442 clear the V bit of the c1 register of CP15.
444 CONFIG_SYS_THUMB_BUILD
446 Use this flag to build U-Boot using the Thumb instruction
447 set for ARM architectures. Thumb instruction set provides
448 better code density. For ARM architectures that support
449 Thumb2 this flag will result in Thumb2 code generated by
452 - Linux Kernel Interface:
455 U-Boot stores all clock information in Hz
456 internally. For binary compatibility with older Linux
457 kernels (which expect the clocks passed in the
458 bd_info data to be in MHz) the environment variable
459 "clocks_in_mhz" can be defined so that U-Boot
460 converts clock data to MHZ before passing it to the
462 When CONFIG_CLOCKS_IN_MHZ is defined, a definition of
463 "clocks_in_mhz=1" is automatically included in the
466 CONFIG_MEMSIZE_IN_BYTES [relevant for MIPS only]
468 When transferring memsize parameter to linux, some versions
469 expect it to be in bytes, others in MB.
470 Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes.
474 New kernel versions are expecting firmware settings to be
475 passed using flattened device trees (based on open firmware
479 * New libfdt-based support
480 * Adds the "fdt" command
481 * The bootm command automatically updates the fdt
483 OF_CPU - The proper name of the cpus node (only required for
484 MPC512X and MPC5xxx based boards).
485 OF_SOC - The proper name of the soc node (only required for
486 MPC512X and MPC5xxx based boards).
487 OF_TBCLK - The timebase frequency.
488 OF_STDOUT_PATH - The path to the console device
490 boards with QUICC Engines require OF_QE to set UCC MAC
493 CONFIG_OF_BOARD_SETUP
495 Board code has addition modification that it wants to make
496 to the flat device tree before handing it off to the kernel
500 This define fills in the correct boot CPU in the boot
501 param header, the default value is zero if undefined.
505 U-Boot can detect if an IDE device is present or not.
506 If not, and this new config option is activated, U-Boot
507 removes the ATA node from the DTS before booting Linux,
508 so the Linux IDE driver does not probe the device and
509 crash. This is needed for buggy hardware (uc101) where
510 no pull down resistor is connected to the signal IDE5V_DD7.
512 CONFIG_MACH_TYPE [relevant for ARM only][mandatory]
514 This setting is mandatory for all boards that have only one
515 machine type and must be used to specify the machine type
516 number as it appears in the ARM machine registry
517 (see http://www.arm.linux.org.uk/developer/machines/).
518 Only boards that have multiple machine types supported
519 in a single configuration file and the machine type is
520 runtime discoverable, do not have to use this setting.
522 - vxWorks boot parameters:
524 bootvx constructs a valid bootline using the following
525 environments variables: bootfile, ipaddr, serverip, hostname.
526 It loads the vxWorks image pointed bootfile.
528 CONFIG_SYS_VXWORKS_BOOT_DEVICE - The vxworks device name
529 CONFIG_SYS_VXWORKS_MAC_PTR - Ethernet 6 byte MA -address
530 CONFIG_SYS_VXWORKS_SERVERNAME - Name of the server
531 CONFIG_SYS_VXWORKS_BOOT_ADDR - Address of boot parameters
533 CONFIG_SYS_VXWORKS_ADD_PARAMS
535 Add it at the end of the bootline. E.g "u=username pw=secret"
537 Note: If a "bootargs" environment is defined, it will overwride
538 the defaults discussed just above.
540 - Cache Configuration:
541 CONFIG_SYS_ICACHE_OFF - Do not enable instruction cache in U-Boot
542 CONFIG_SYS_DCACHE_OFF - Do not enable data cache in U-Boot
543 CONFIG_SYS_L2CACHE_OFF- Do not enable L2 cache in U-Boot
545 - Cache Configuration for ARM:
546 CONFIG_SYS_L2_PL310 - Enable support for ARM PL310 L2 cache
548 CONFIG_SYS_PL310_BASE - Physical base address of PL310
549 controller register space
554 Define this if you want support for Amba PrimeCell PL010 UARTs.
558 Define this if you want support for Amba PrimeCell PL011 UARTs.
562 If you have Amba PrimeCell PL011 UARTs, set this variable to
563 the clock speed of the UARTs.
567 If you have Amba PrimeCell PL010 or PL011 UARTs on your board,
568 define this to a list of base addresses for each (supported)
569 port. See e.g. include/configs/versatile.h
571 CONFIG_PL011_SERIAL_RLCR
573 Some vendor versions of PL011 serial ports (e.g. ST-Ericsson U8500)
574 have separate receive and transmit line control registers. Set
575 this variable to initialize the extra register.
577 CONFIG_PL011_SERIAL_FLUSH_ON_INIT
579 On some platforms (e.g. U8500) U-Boot is loaded by a second stage
580 boot loader that has already initialized the UART. Define this
581 variable to flush the UART at init time.
585 Depending on board, define exactly one serial port
586 (like CONFIG_8xx_CONS_SMC1, CONFIG_8xx_CONS_SMC2,
587 CONFIG_8xx_CONS_SCC1, ...), or switch off the serial
588 console by defining CONFIG_8xx_CONS_NONE
590 Note: if CONFIG_8xx_CONS_NONE is defined, the serial
591 port routines must be defined elsewhere
592 (i.e. serial_init(), serial_getc(), ...)
595 Enables console device for a color framebuffer. Needs following
596 defines (cf. smiLynxEM, i8042)
597 VIDEO_FB_LITTLE_ENDIAN graphic memory organisation
599 VIDEO_HW_RECTFILL graphic chip supports
602 VIDEO_HW_BITBLT graphic chip supports
603 bit-blit (cf. smiLynxEM)
604 VIDEO_VISIBLE_COLS visible pixel columns
606 VIDEO_VISIBLE_ROWS visible pixel rows
607 VIDEO_PIXEL_SIZE bytes per pixel
608 VIDEO_DATA_FORMAT graphic data format
609 (0-5, cf. cfb_console.c)
610 VIDEO_FB_ADRS framebuffer address
611 VIDEO_KBD_INIT_FCT keyboard int fct
612 (i.e. i8042_kbd_init())
613 VIDEO_TSTC_FCT test char fct
615 VIDEO_GETC_FCT get char fct
617 CONFIG_CONSOLE_CURSOR cursor drawing on/off
618 (requires blink timer
620 CONFIG_SYS_CONSOLE_BLINK_COUNT blink interval (cf. i8042.c)
621 CONFIG_CONSOLE_TIME display time/date info in
623 (requires CONFIG_CMD_DATE)
624 CONFIG_VIDEO_LOGO display Linux logo in
626 CONFIG_VIDEO_BMP_LOGO use bmp_logo.h instead of
627 linux_logo.h for logo.
628 Requires CONFIG_VIDEO_LOGO
629 CONFIG_CONSOLE_EXTRA_INFO
630 additional board info beside
633 When CONFIG_CFB_CONSOLE is defined, video console is
634 default i/o. Serial console can be forced with
635 environment 'console=serial'.
637 When CONFIG_SILENT_CONSOLE is defined, all console
638 messages (by U-Boot and Linux!) can be silenced with
639 the "silent" environment variable. See
640 doc/README.silent for more information.
643 CONFIG_BAUDRATE - in bps
644 Select one of the baudrates listed in
645 CONFIG_SYS_BAUDRATE_TABLE, see below.
646 CONFIG_SYS_BRGCLK_PRESCALE, baudrate prescale
648 - Console Rx buffer length
649 With CONFIG_SYS_SMC_RXBUFLEN it is possible to define
650 the maximum receive buffer length for the SMC.
651 This option is actual only for 82xx and 8xx possible.
652 If using CONFIG_SYS_SMC_RXBUFLEN also CONFIG_SYS_MAXIDLE
653 must be defined, to setup the maximum idle timeout for
656 - Pre-Console Buffer:
657 Prior to the console being initialised (i.e. serial UART
658 initialised etc) all console output is silently discarded.
659 Defining CONFIG_PRE_CONSOLE_BUFFER will cause U-Boot to
660 buffer any console messages prior to the console being
661 initialised to a buffer of size CONFIG_PRE_CON_BUF_SZ
662 bytes located at CONFIG_PRE_CON_BUF_ADDR. The buffer is
663 a circular buffer, so if more than CONFIG_PRE_CON_BUF_SZ
664 bytes are output before the console is initialised, the
665 earlier bytes are discarded.
667 'Sane' compilers will generate smaller code if
668 CONFIG_PRE_CON_BUF_SZ is a power of 2
670 - Safe printf() functions
671 Define CONFIG_SYS_VSNPRINTF to compile in safe versions of
672 the printf() functions. These are defined in
673 include/vsprintf.h and include snprintf(), vsnprintf() and
674 so on. Code size increase is approximately 300-500 bytes.
675 If this option is not given then these functions will
676 silently discard their buffer size argument - this means
677 you are not getting any overflow checking in this case.
679 - Boot Delay: CONFIG_BOOTDELAY - in seconds
680 Delay before automatically booting the default image;
681 set to -1 to disable autoboot.
683 See doc/README.autoboot for these options that
684 work with CONFIG_BOOTDELAY. None are required.
685 CONFIG_BOOT_RETRY_TIME
686 CONFIG_BOOT_RETRY_MIN
687 CONFIG_AUTOBOOT_KEYED
688 CONFIG_AUTOBOOT_PROMPT
689 CONFIG_AUTOBOOT_DELAY_STR
690 CONFIG_AUTOBOOT_STOP_STR
691 CONFIG_AUTOBOOT_DELAY_STR2
692 CONFIG_AUTOBOOT_STOP_STR2
693 CONFIG_ZERO_BOOTDELAY_CHECK
694 CONFIG_RESET_TO_RETRY
698 Only needed when CONFIG_BOOTDELAY is enabled;
699 define a command string that is automatically executed
700 when no character is read on the console interface
701 within "Boot Delay" after reset.
704 This can be used to pass arguments to the bootm
705 command. The value of CONFIG_BOOTARGS goes into the
706 environment value "bootargs".
708 CONFIG_RAMBOOT and CONFIG_NFSBOOT
709 The value of these goes into the environment as
710 "ramboot" and "nfsboot" respectively, and can be used
711 as a convenience, when switching between booting from
717 When this option is #defined, the existence of the
718 environment variable "preboot" will be checked
719 immediately before starting the CONFIG_BOOTDELAY
720 countdown and/or running the auto-boot command resp.
721 entering interactive mode.
723 This feature is especially useful when "preboot" is
724 automatically generated or modified. For an example
725 see the LWMON board specific code: here "preboot" is
726 modified when the user holds down a certain
727 combination of keys on the (special) keyboard when
730 - Serial Download Echo Mode:
732 If defined to 1, all characters received during a
733 serial download (using the "loads" command) are
734 echoed back. This might be needed by some terminal
735 emulations (like "cu"), but may as well just take
736 time on others. This setting #define's the initial
737 value of the "loads_echo" environment variable.
739 - Kgdb Serial Baudrate: (if CONFIG_CMD_KGDB is defined)
741 Select one of the baudrates listed in
742 CONFIG_SYS_BAUDRATE_TABLE, see below.
745 Monitor commands can be included or excluded
746 from the build by using the #include files
747 <config_cmd_all.h> and #undef'ing unwanted
748 commands, or using <config_cmd_default.h>
749 and augmenting with additional #define's
752 The default command configuration includes all commands
753 except those marked below with a "*".
755 CONFIG_CMD_ASKENV * ask for env variable
756 CONFIG_CMD_BDI bdinfo
757 CONFIG_CMD_BEDBUG * Include BedBug Debugger
758 CONFIG_CMD_BMP * BMP support
759 CONFIG_CMD_BSP * Board specific commands
760 CONFIG_CMD_BOOTD bootd
761 CONFIG_CMD_CACHE * icache, dcache
762 CONFIG_CMD_CONSOLE coninfo
763 CONFIG_CMD_CRC32 * crc32
764 CONFIG_CMD_DATE * support for RTC, date/time...
765 CONFIG_CMD_DHCP * DHCP support
766 CONFIG_CMD_DIAG * Diagnostics
767 CONFIG_CMD_DS4510 * ds4510 I2C gpio commands
768 CONFIG_CMD_DS4510_INFO * ds4510 I2C info command
769 CONFIG_CMD_DS4510_MEM * ds4510 I2C eeprom/sram commansd
770 CONFIG_CMD_DS4510_RST * ds4510 I2C rst command
771 CONFIG_CMD_DTT * Digital Therm and Thermostat
772 CONFIG_CMD_ECHO echo arguments
773 CONFIG_CMD_EDITENV edit env variable
774 CONFIG_CMD_EEPROM * EEPROM read/write support
775 CONFIG_CMD_ELF * bootelf, bootvx
776 CONFIG_CMD_EXPORTENV * export the environment
777 CONFIG_CMD_SAVEENV saveenv
778 CONFIG_CMD_FDC * Floppy Disk Support
779 CONFIG_CMD_FAT * FAT partition support
780 CONFIG_CMD_FDOS * Dos diskette Support
781 CONFIG_CMD_FLASH flinfo, erase, protect
782 CONFIG_CMD_FPGA FPGA device initialization support
783 CONFIG_CMD_GO * the 'go' command (exec code)
784 CONFIG_CMD_GREPENV * search environment
785 CONFIG_CMD_HWFLOW * RTS/CTS hw flow control
786 CONFIG_CMD_I2C * I2C serial bus support
787 CONFIG_CMD_IDE * IDE harddisk support
788 CONFIG_CMD_IMI iminfo
789 CONFIG_CMD_IMLS List all found images
790 CONFIG_CMD_IMMAP * IMMR dump support
791 CONFIG_CMD_IMPORTENV * import an environment
792 CONFIG_CMD_IRQ * irqinfo
793 CONFIG_CMD_ITEST Integer/string test of 2 values
794 CONFIG_CMD_JFFS2 * JFFS2 Support
795 CONFIG_CMD_KGDB * kgdb
796 CONFIG_CMD_LDRINFO ldrinfo (display Blackfin loader)
797 CONFIG_CMD_LINK_LOCAL * link-local IP address auto-configuration
799 CONFIG_CMD_LOADB loadb
800 CONFIG_CMD_LOADS loads
801 CONFIG_CMD_MD5SUM print md5 message digest
802 (requires CONFIG_CMD_MEMORY and CONFIG_MD5)
803 CONFIG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base,
805 CONFIG_CMD_MISC Misc functions like sleep etc
806 CONFIG_CMD_MMC * MMC memory mapped support
807 CONFIG_CMD_MII * MII utility commands
808 CONFIG_CMD_MTDPARTS * MTD partition support
809 CONFIG_CMD_NAND * NAND support
810 CONFIG_CMD_NET bootp, tftpboot, rarpboot
811 CONFIG_CMD_PCA953X * PCA953x I2C gpio commands
812 CONFIG_CMD_PCA953X_INFO * PCA953x I2C gpio info command
813 CONFIG_CMD_PCI * pciinfo
814 CONFIG_CMD_PCMCIA * PCMCIA support
815 CONFIG_CMD_PING * send ICMP ECHO_REQUEST to network
817 CONFIG_CMD_PORTIO * Port I/O
818 CONFIG_CMD_REGINFO * Register dump
819 CONFIG_CMD_RUN run command in env variable
820 CONFIG_CMD_SAVES * save S record dump
821 CONFIG_CMD_SCSI * SCSI Support
822 CONFIG_CMD_SDRAM * print SDRAM configuration information
823 (requires CONFIG_CMD_I2C)
824 CONFIG_CMD_SETGETDCR Support for DCR Register access
826 CONFIG_CMD_SF * Read/write/erase SPI NOR flash
827 CONFIG_CMD_SHA1SUM print sha1 memory digest
828 (requires CONFIG_CMD_MEMORY)
829 CONFIG_CMD_SOURCE "source" command Support
830 CONFIG_CMD_SPI * SPI serial bus support
831 CONFIG_CMD_TFTPSRV * TFTP transfer in server mode
832 CONFIG_CMD_TFTPPUT * TFTP put command (upload)
833 CONFIG_CMD_TIME * run command and report execution time
834 CONFIG_CMD_USB * USB support
835 CONFIG_CMD_CDP * Cisco Discover Protocol support
836 CONFIG_CMD_MFSL * Microblaze FSL support
839 EXAMPLE: If you want all functions except of network
840 support you can write:
842 #include "config_cmd_all.h"
843 #undef CONFIG_CMD_NET
846 fdt (flattened device tree) command: CONFIG_OF_LIBFDT
848 Note: Don't enable the "icache" and "dcache" commands
849 (configuration option CONFIG_CMD_CACHE) unless you know
850 what you (and your U-Boot users) are doing. Data
851 cache cannot be enabled on systems like the 8xx or
852 8260 (where accesses to the IMMR region must be
853 uncached), and it cannot be disabled on all other
854 systems where we (mis-) use the data cache to hold an
855 initial stack and some data.
858 XXX - this list needs to get updated!
862 If this variable is defined, U-Boot will use a device tree
863 to configure its devices, instead of relying on statically
864 compiled #defines in the board file. This option is
865 experimental and only available on a few boards. The device
866 tree is available in the global data as gd->fdt_blob.
868 U-Boot needs to get its device tree from somewhere. This can
869 be done using one of the two options below:
872 If this variable is defined, U-Boot will embed a device tree
873 binary in its image. This device tree file should be in the
874 board directory and called <soc>-<board>.dts. The binary file
875 is then picked up in board_init_f() and made available through
876 the global data structure as gd->blob.
879 If this variable is defined, U-Boot will build a device tree
880 binary. It will be called u-boot.dtb. Architecture-specific
881 code will locate it at run-time. Generally this works by:
883 cat u-boot.bin u-boot.dtb >image.bin
885 and in fact, U-Boot does this for you, creating a file called
886 u-boot-dtb.bin which is useful in the common case. You can
887 still use the individual files if you need something more
892 If this variable is defined, it enables watchdog
893 support for the SoC. There must be support in the SoC
894 specific code for a watchdog. For the 8xx and 8260
895 CPUs, the SIU Watchdog feature is enabled in the SYPCR
896 register. When supported for a specific SoC is
897 available, then no further board specific code should
901 When using a watchdog circuitry external to the used
902 SoC, then define this variable and provide board
903 specific code for the "hw_watchdog_reset" function.
906 CONFIG_VERSION_VARIABLE
907 If this variable is defined, an environment variable
908 named "ver" is created by U-Boot showing the U-Boot
909 version as printed by the "version" command.
910 Any change to this variable will be reverted at the
915 When CONFIG_CMD_DATE is selected, the type of the RTC
916 has to be selected, too. Define exactly one of the
919 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx
920 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC
921 CONFIG_RTC_MC13XXX - use MC13783 or MC13892 RTC
922 CONFIG_RTC_MC146818 - use MC146818 RTC
923 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC
924 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC
925 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC
926 CONFIG_RTC_DS164x - use Dallas DS164x RTC
927 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC
928 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC
929 CONFIG_SYS_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337
930 CONFIG_SYS_RV3029_TCR - enable trickle charger on
933 Note that if the RTC uses I2C, then the I2C interface
934 must also be configured. See I2C Support, below.
937 CONFIG_PCA953X - use NXP's PCA953X series I2C GPIO
938 CONFIG_PCA953X_INFO - enable pca953x info command
940 The CONFIG_SYS_I2C_PCA953X_WIDTH option specifies a list of
941 chip-ngpio pairs that tell the PCA953X driver the number of
942 pins supported by a particular chip.
944 Note that if the GPIO device uses I2C, then the I2C interface
945 must also be configured. See I2C Support, below.
949 When CONFIG_TIMESTAMP is selected, the timestamp
950 (date and time) of an image is printed by image
951 commands like bootm or iminfo. This option is
952 automatically enabled when you select CONFIG_CMD_DATE .
954 - Partition Labels (disklabels) Supported:
955 Zero or more of the following:
956 CONFIG_MAC_PARTITION Apple's MacOS partition table.
957 CONFIG_DOS_PARTITION MS Dos partition table, traditional on the
958 Intel architecture, USB sticks, etc.
959 CONFIG_ISO_PARTITION ISO partition table, used on CDROM etc.
960 CONFIG_EFI_PARTITION GPT partition table, common when EFI is the
961 bootloader. Note 2TB partition limit; see
963 CONFIG_MTD_PARTITIONS Memory Technology Device partition table.
965 If IDE or SCSI support is enabled (CONFIG_CMD_IDE or
966 CONFIG_CMD_SCSI) you must configure support for at
967 least one non-MTD partition type as well.
970 CONFIG_IDE_RESET_ROUTINE - this is defined in several
971 board configurations files but used nowhere!
973 CONFIG_IDE_RESET - is this is defined, IDE Reset will
974 be performed by calling the function
975 ide_set_reset(int reset)
976 which has to be defined in a board specific file
981 Set this to enable ATAPI support.
986 Set this to enable support for disks larger than 137GB
987 Also look at CONFIG_SYS_64BIT_LBA.
988 Whithout these , LBA48 support uses 32bit variables and will 'only'
989 support disks up to 2.1TB.
991 CONFIG_SYS_64BIT_LBA:
992 When enabled, makes the IDE subsystem use 64bit sector addresses.
996 At the moment only there is only support for the
997 SYM53C8XX SCSI controller; define
998 CONFIG_SCSI_SYM53C8XX to enable it.
1000 CONFIG_SYS_SCSI_MAX_LUN [8], CONFIG_SYS_SCSI_MAX_SCSI_ID [7] and
1001 CONFIG_SYS_SCSI_MAX_DEVICE [CONFIG_SYS_SCSI_MAX_SCSI_ID *
1002 CONFIG_SYS_SCSI_MAX_LUN] can be adjusted to define the
1003 maximum numbers of LUNs, SCSI ID's and target
1005 CONFIG_SYS_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz)
1007 - NETWORK Support (PCI):
1009 Support for Intel 8254x/8257x gigabit chips.
1012 Utility code for direct access to the SPI bus on Intel 8257x.
1013 This does not do anything useful unless you set at least one
1014 of CONFIG_CMD_E1000 or CONFIG_E1000_SPI_GENERIC.
1016 CONFIG_E1000_SPI_GENERIC
1017 Allow generic access to the SPI bus on the Intel 8257x, for
1018 example with the "sspi" command.
1021 Management command for E1000 devices. When used on devices
1022 with SPI support you can reprogram the EEPROM from U-Boot.
1024 CONFIG_E1000_FALLBACK_MAC
1025 default MAC for empty EEPROM after production.
1028 Support for Intel 82557/82559/82559ER chips.
1029 Optional CONFIG_EEPRO100_SROM_WRITE enables EEPROM
1030 write routine for first time initialisation.
1033 Support for Digital 2114x chips.
1034 Optional CONFIG_TULIP_SELECT_MEDIA for board specific
1035 modem chip initialisation (KS8761/QS6611).
1038 Support for National dp83815 chips.
1041 Support for National dp8382[01] gigabit chips.
1043 - NETWORK Support (other):
1045 CONFIG_DRIVER_AT91EMAC
1046 Support for AT91RM9200 EMAC.
1049 Define this to use reduced MII inteface
1051 CONFIG_DRIVER_AT91EMAC_QUIET
1052 If this defined, the driver is quiet.
1053 The driver doen't show link status messages.
1055 CONFIG_CALXEDA_XGMAC
1056 Support for the Calxeda XGMAC device
1058 CONFIG_DRIVER_LAN91C96
1059 Support for SMSC's LAN91C96 chips.
1061 CONFIG_LAN91C96_BASE
1062 Define this to hold the physical address
1063 of the LAN91C96's I/O space
1065 CONFIG_LAN91C96_USE_32_BIT
1066 Define this to enable 32 bit addressing
1068 CONFIG_DRIVER_SMC91111
1069 Support for SMSC's LAN91C111 chip
1071 CONFIG_SMC91111_BASE
1072 Define this to hold the physical address
1073 of the device (I/O space)
1075 CONFIG_SMC_USE_32_BIT
1076 Define this if data bus is 32 bits
1078 CONFIG_SMC_USE_IOFUNCS
1079 Define this to use i/o functions instead of macros
1080 (some hardware wont work with macros)
1082 CONFIG_DRIVER_TI_EMAC
1083 Support for davinci emac
1085 CONFIG_SYS_DAVINCI_EMAC_PHY_COUNT
1086 Define this if you have more then 3 PHYs.
1089 Support for Faraday's FTGMAC100 Gigabit SoC Ethernet
1091 CONFIG_FTGMAC100_EGIGA
1092 Define this to use GE link update with gigabit PHY.
1093 Define this if FTGMAC100 is connected to gigabit PHY.
1094 If your system has 10/100 PHY only, it might not occur
1095 wrong behavior. Because PHY usually return timeout or
1096 useless data when polling gigabit status and gigabit
1097 control registers. This behavior won't affect the
1098 correctnessof 10/100 link speed update.
1101 Support for SMSC's LAN911x and LAN921x chips
1104 Define this to hold the physical address
1105 of the device (I/O space)
1107 CONFIG_SMC911X_32_BIT
1108 Define this if data bus is 32 bits
1110 CONFIG_SMC911X_16_BIT
1111 Define this if data bus is 16 bits. If your processor
1112 automatically converts one 32 bit word to two 16 bit
1113 words you may also try CONFIG_SMC911X_32_BIT.
1116 Support for Renesas on-chip Ethernet controller
1118 CONFIG_SH_ETHER_USE_PORT
1119 Define the number of ports to be used
1121 CONFIG_SH_ETHER_PHY_ADDR
1122 Define the ETH PHY's address
1124 CONFIG_SH_ETHER_CACHE_WRITEBACK
1125 If this option is set, the driver enables cache flush.
1128 CONFIG_GENERIC_LPC_TPM
1129 Support for generic parallel port TPM devices. Only one device
1130 per system is supported at this time.
1132 CONFIG_TPM_TIS_BASE_ADDRESS
1133 Base address where the generic TPM device is mapped
1134 to. Contemporary x86 systems usually map it at
1138 At the moment only the UHCI host controller is
1139 supported (PIP405, MIP405, MPC5200); define
1140 CONFIG_USB_UHCI to enable it.
1141 define CONFIG_USB_KEYBOARD to enable the USB Keyboard
1142 and define CONFIG_USB_STORAGE to enable the USB
1145 Supported are USB Keyboards and USB Floppy drives
1147 MPC5200 USB requires additional defines:
1149 for 528 MHz Clock: 0x0001bbbb
1153 for differential drivers: 0x00001000
1154 for single ended drivers: 0x00005000
1155 for differential drivers on PSC3: 0x00000100
1156 for single ended drivers on PSC3: 0x00004100
1157 CONFIG_SYS_USB_EVENT_POLL
1158 May be defined to allow interrupt polling
1159 instead of using asynchronous interrupts
1161 CONFIG_USB_EHCI_TXFIFO_THRESH enables setting of the
1162 txfilltuning field in the EHCI controller on reset.
1165 Define the below if you wish to use the USB console.
1166 Once firmware is rebuilt from a serial console issue the
1167 command "setenv stdin usbtty; setenv stdout usbtty" and
1168 attach your USB cable. The Unix command "dmesg" should print
1169 it has found a new device. The environment variable usbtty
1170 can be set to gserial or cdc_acm to enable your device to
1171 appear to a USB host as a Linux gserial device or a
1172 Common Device Class Abstract Control Model serial device.
1173 If you select usbtty = gserial you should be able to enumerate
1175 # modprobe usbserial vendor=0xVendorID product=0xProductID
1176 else if using cdc_acm, simply setting the environment
1177 variable usbtty to be cdc_acm should suffice. The following
1178 might be defined in YourBoardName.h
1181 Define this to build a UDC device
1184 Define this to have a tty type of device available to
1185 talk to the UDC device
1188 Define this to enable the high speed support for usb
1189 device and usbtty. If this feature is enabled, a routine
1190 int is_usbd_high_speed(void)
1191 also needs to be defined by the driver to dynamically poll
1192 whether the enumeration has succeded at high speed or full
1195 CONFIG_SYS_CONSOLE_IS_IN_ENV
1196 Define this if you want stdin, stdout &/or stderr to
1200 CONFIG_SYS_USB_EXTC_CLK 0xBLAH
1201 Derive USB clock from external clock "blah"
1202 - CONFIG_SYS_USB_EXTC_CLK 0x02
1204 CONFIG_SYS_USB_BRG_CLK 0xBLAH
1205 Derive USB clock from brgclk
1206 - CONFIG_SYS_USB_BRG_CLK 0x04
1208 If you have a USB-IF assigned VendorID then you may wish to
1209 define your own vendor specific values either in BoardName.h
1210 or directly in usbd_vendor_info.h. If you don't define
1211 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME,
1212 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot
1213 should pretend to be a Linux device to it's target host.
1215 CONFIG_USBD_MANUFACTURER
1216 Define this string as the name of your company for
1217 - CONFIG_USBD_MANUFACTURER "my company"
1219 CONFIG_USBD_PRODUCT_NAME
1220 Define this string as the name of your product
1221 - CONFIG_USBD_PRODUCT_NAME "acme usb device"
1223 CONFIG_USBD_VENDORID
1224 Define this as your assigned Vendor ID from the USB
1225 Implementors Forum. This *must* be a genuine Vendor ID
1226 to avoid polluting the USB namespace.
1227 - CONFIG_USBD_VENDORID 0xFFFF
1229 CONFIG_USBD_PRODUCTID
1230 Define this as the unique Product ID
1232 - CONFIG_USBD_PRODUCTID 0xFFFF
1234 - ULPI Layer Support:
1235 The ULPI (UTMI Low Pin (count) Interface) PHYs are supported via
1236 the generic ULPI layer. The generic layer accesses the ULPI PHY
1237 via the platform viewport, so you need both the genric layer and
1238 the viewport enabled. Currently only Chipidea/ARC based
1239 viewport is supported.
1240 To enable the ULPI layer support, define CONFIG_USB_ULPI and
1241 CONFIG_USB_ULPI_VIEWPORT in your board configuration file.
1244 The MMC controller on the Intel PXA is supported. To
1245 enable this define CONFIG_MMC. The MMC can be
1246 accessed from the boot prompt by mapping the device
1247 to physical memory similar to flash. Command line is
1248 enabled with CONFIG_CMD_MMC. The MMC driver also works with
1249 the FAT fs. This is enabled with CONFIG_CMD_FAT.
1252 Support for Renesas on-chip MMCIF controller
1254 CONFIG_SH_MMCIF_ADDR
1255 Define the base address of MMCIF registers
1258 Define the clock frequency for MMCIF
1260 - Journaling Flash filesystem support:
1261 CONFIG_JFFS2_NAND, CONFIG_JFFS2_NAND_OFF, CONFIG_JFFS2_NAND_SIZE,
1262 CONFIG_JFFS2_NAND_DEV
1263 Define these for a default partition on a NAND device
1265 CONFIG_SYS_JFFS2_FIRST_SECTOR,
1266 CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS
1267 Define these for a default partition on a NOR device
1269 CONFIG_SYS_JFFS_CUSTOM_PART
1270 Define this to create an own partition. You have to provide a
1271 function struct part_info* jffs2_part_info(int part_num)
1273 If you define only one JFFS2 partition you may also want to
1274 #define CONFIG_SYS_JFFS_SINGLE_PART 1
1275 to disable the command chpart. This is the default when you
1276 have not defined a custom partition
1278 - FAT(File Allocation Table) filesystem write function support:
1281 Define this to enable support for saving memory data as a
1282 file in FAT formatted partition.
1284 This will also enable the command "fatwrite" enabling the
1285 user to write files to FAT.
1290 Define this to enable standard (PC-Style) keyboard
1294 Standard PC keyboard driver with US (is default) and
1295 GERMAN key layout (switch via environment 'keymap=de') support.
1296 Export function i8042_kbd_init, i8042_tstc and i8042_getc
1297 for cfb_console. Supports cursor blinking.
1302 Define this to enable video support (for output to
1305 CONFIG_VIDEO_CT69000
1307 Enable Chips & Technologies 69000 Video chip
1309 CONFIG_VIDEO_SMI_LYNXEM
1310 Enable Silicon Motion SMI 712/710/810 Video chip. The
1311 video output is selected via environment 'videoout'
1312 (1 = LCD and 2 = CRT). If videoout is undefined, CRT is
1315 For the CT69000 and SMI_LYNXEM drivers, videomode is
1316 selected via environment 'videomode'. Two different ways
1318 - "videomode=num" 'num' is a standard LiLo mode numbers.
1319 Following standard modes are supported (* is default):
1321 Colors 640x480 800x600 1024x768 1152x864 1280x1024
1322 -------------+---------------------------------------------
1323 8 bits | 0x301* 0x303 0x305 0x161 0x307
1324 15 bits | 0x310 0x313 0x316 0x162 0x319
1325 16 bits | 0x311 0x314 0x317 0x163 0x31A
1326 24 bits | 0x312 0x315 0x318 ? 0x31B
1327 -------------+---------------------------------------------
1328 (i.e. setenv videomode 317; saveenv; reset;)
1330 - "videomode=bootargs" all the video parameters are parsed
1331 from the bootargs. (See drivers/video/videomodes.c)
1334 CONFIG_VIDEO_SED13806
1335 Enable Epson SED13806 driver. This driver supports 8bpp
1336 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP
1337 or CONFIG_VIDEO_SED13806_16BPP
1340 Enable the Freescale DIU video driver. Reference boards for
1341 SOCs that have a DIU should define this macro to enable DIU
1342 support, and should also define these other macros:
1348 CONFIG_VIDEO_SW_CURSOR
1349 CONFIG_VGA_AS_SINGLE_DEVICE
1351 CONFIG_VIDEO_BMP_LOGO
1353 The DIU driver will look for the 'video-mode' environment
1354 variable, and if defined, enable the DIU as a console during
1355 boot. See the documentation file README.video for a
1356 description of this variable.
1361 Define this to enable a custom keyboard support.
1362 This simply calls drv_keyboard_init() which must be
1363 defined in your board-specific files.
1364 The only board using this so far is RBC823.
1366 - LCD Support: CONFIG_LCD
1368 Define this to enable LCD support (for output to LCD
1369 display); also select one of the supported displays
1370 by defining one of these:
1374 HITACHI TX09D70VM1CCA, 3.5", 240x320.
1376 CONFIG_NEC_NL6448AC33:
1378 NEC NL6448AC33-18. Active, color, single scan.
1380 CONFIG_NEC_NL6448BC20
1382 NEC NL6448BC20-08. 6.5", 640x480.
1383 Active, color, single scan.
1385 CONFIG_NEC_NL6448BC33_54
1387 NEC NL6448BC33-54. 10.4", 640x480.
1388 Active, color, single scan.
1392 Sharp 320x240. Active, color, single scan.
1393 It isn't 16x9, and I am not sure what it is.
1395 CONFIG_SHARP_LQ64D341
1397 Sharp LQ64D341 display, 640x480.
1398 Active, color, single scan.
1402 HLD1045 display, 640x480.
1403 Active, color, single scan.
1407 Optrex CBL50840-2 NF-FW 99 22 M5
1409 Hitachi LMG6912RPFC-00T
1413 320x240. Black & white.
1415 Normally display is black on white background; define
1416 CONFIG_SYS_WHITE_ON_BLACK to get it inverted.
1418 - Splash Screen Support: CONFIG_SPLASH_SCREEN
1420 If this option is set, the environment is checked for
1421 a variable "splashimage". If found, the usual display
1422 of logo, copyright and system information on the LCD
1423 is suppressed and the BMP image at the address
1424 specified in "splashimage" is loaded instead. The
1425 console is redirected to the "nulldev", too. This
1426 allows for a "silent" boot where a splash screen is
1427 loaded very quickly after power-on.
1429 CONFIG_SPLASH_SCREEN_ALIGN
1431 If this option is set the splash image can be freely positioned
1432 on the screen. Environment variable "splashpos" specifies the
1433 position as "x,y". If a positive number is given it is used as
1434 number of pixel from left/top. If a negative number is given it
1435 is used as number of pixel from right/bottom. You can also
1436 specify 'm' for centering the image.
1439 setenv splashpos m,m
1440 => image at center of screen
1442 setenv splashpos 30,20
1443 => image at x = 30 and y = 20
1445 setenv splashpos -10,m
1446 => vertically centered image
1447 at x = dspWidth - bmpWidth - 9
1449 - Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP
1451 If this option is set, additionally to standard BMP
1452 images, gzipped BMP images can be displayed via the
1453 splashscreen support or the bmp command.
1455 - Run length encoded BMP image (RLE8) support: CONFIG_VIDEO_BMP_RLE8
1457 If this option is set, 8-bit RLE compressed BMP images
1458 can be displayed via the splashscreen support or the
1461 - Compression support:
1464 If this option is set, support for bzip2 compressed
1465 images is included. If not, only uncompressed and gzip
1466 compressed images are supported.
1468 NOTE: the bzip2 algorithm requires a lot of RAM, so
1469 the malloc area (as defined by CONFIG_SYS_MALLOC_LEN) should
1474 If this option is set, support for lzma compressed
1477 Note: The LZMA algorithm adds between 2 and 4KB of code and it
1478 requires an amount of dynamic memory that is given by the
1481 (1846 + 768 << (lc + lp)) * sizeof(uint16)
1483 Where lc and lp stand for, respectively, Literal context bits
1484 and Literal pos bits.
1486 This value is upper-bounded by 14MB in the worst case. Anyway,
1487 for a ~4MB large kernel image, we have lc=3 and lp=0 for a
1488 total amount of (1846 + 768 << (3 + 0)) * 2 = ~41KB... that is
1489 a very small buffer.
1491 Use the lzmainfo tool to determinate the lc and lp values and
1492 then calculate the amount of needed dynamic memory (ensuring
1493 the appropriate CONFIG_SYS_MALLOC_LEN value).
1498 The address of PHY on MII bus.
1500 CONFIG_PHY_CLOCK_FREQ (ppc4xx)
1502 The clock frequency of the MII bus
1506 If this option is set, support for speed/duplex
1507 detection of gigabit PHY is included.
1509 CONFIG_PHY_RESET_DELAY
1511 Some PHY like Intel LXT971A need extra delay after
1512 reset before any MII register access is possible.
1513 For such PHY, set this option to the usec delay
1514 required. (minimum 300usec for LXT971A)
1516 CONFIG_PHY_CMD_DELAY (ppc4xx)
1518 Some PHY like Intel LXT971A need extra delay after
1519 command issued before MII status register can be read
1529 Define a default value for Ethernet address to use
1530 for the respective Ethernet interface, in case this
1531 is not determined automatically.
1536 Define a default value for the IP address to use for
1537 the default Ethernet interface, in case this is not
1538 determined through e.g. bootp.
1539 (Environment variable "ipaddr")
1541 - Server IP address:
1544 Defines a default value for the IP address of a TFTP
1545 server to contact when using the "tftboot" command.
1546 (Environment variable "serverip")
1548 CONFIG_KEEP_SERVERADDR
1550 Keeps the server's MAC address, in the env 'serveraddr'
1551 for passing to bootargs (like Linux's netconsole option)
1553 - Gateway IP address:
1556 Defines a default value for the IP address of the
1557 default router where packets to other networks are
1559 (Environment variable "gatewayip")
1564 Defines a default value for the subnet mask (or
1565 routing prefix) which is used to determine if an IP
1566 address belongs to the local subnet or needs to be
1567 forwarded through a router.
1568 (Environment variable "netmask")
1570 - Multicast TFTP Mode:
1573 Defines whether you want to support multicast TFTP as per
1574 rfc-2090; for example to work with atftp. Lets lots of targets
1575 tftp down the same boot image concurrently. Note: the Ethernet
1576 driver in use must provide a function: mcast() to join/leave a
1579 - BOOTP Recovery Mode:
1580 CONFIG_BOOTP_RANDOM_DELAY
1582 If you have many targets in a network that try to
1583 boot using BOOTP, you may want to avoid that all
1584 systems send out BOOTP requests at precisely the same
1585 moment (which would happen for instance at recovery
1586 from a power failure, when all systems will try to
1587 boot, thus flooding the BOOTP server. Defining
1588 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
1589 inserted before sending out BOOTP requests. The
1590 following delays are inserted then:
1592 1st BOOTP request: delay 0 ... 1 sec
1593 2nd BOOTP request: delay 0 ... 2 sec
1594 3rd BOOTP request: delay 0 ... 4 sec
1596 BOOTP requests: delay 0 ... 8 sec
1598 - DHCP Advanced Options:
1599 You can fine tune the DHCP functionality by defining
1600 CONFIG_BOOTP_* symbols:
1602 CONFIG_BOOTP_SUBNETMASK
1603 CONFIG_BOOTP_GATEWAY
1604 CONFIG_BOOTP_HOSTNAME
1605 CONFIG_BOOTP_NISDOMAIN
1606 CONFIG_BOOTP_BOOTPATH
1607 CONFIG_BOOTP_BOOTFILESIZE
1610 CONFIG_BOOTP_SEND_HOSTNAME
1611 CONFIG_BOOTP_NTPSERVER
1612 CONFIG_BOOTP_TIMEOFFSET
1613 CONFIG_BOOTP_VENDOREX
1614 CONFIG_BOOTP_MAY_FAIL
1616 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip
1617 environment variable, not the BOOTP server.
1619 CONFIG_BOOTP_MAY_FAIL - If the DHCP server is not found
1620 after the configured retry count, the call will fail
1621 instead of starting over. This can be used to fail over
1622 to Link-local IP address configuration if the DHCP server
1625 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS
1626 serverip from a DHCP server, it is possible that more
1627 than one DNS serverip is offered to the client.
1628 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS
1629 serverip will be stored in the additional environment
1630 variable "dnsip2". The first DNS serverip is always
1631 stored in the variable "dnsip", when CONFIG_BOOTP_DNS
1634 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable
1635 to do a dynamic update of a DNS server. To do this, they
1636 need the hostname of the DHCP requester.
1637 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content
1638 of the "hostname" environment variable is passed as
1639 option 12 to the DHCP server.
1641 CONFIG_BOOTP_DHCP_REQUEST_DELAY
1643 A 32bit value in microseconds for a delay between
1644 receiving a "DHCP Offer" and sending the "DHCP Request".
1645 This fixes a problem with certain DHCP servers that don't
1646 respond 100% of the time to a "DHCP request". E.g. On an
1647 AT91RM9200 processor running at 180MHz, this delay needed
1648 to be *at least* 15,000 usec before a Windows Server 2003
1649 DHCP server would reply 100% of the time. I recommend at
1650 least 50,000 usec to be safe. The alternative is to hope
1651 that one of the retries will be successful but note that
1652 the DHCP timeout and retry process takes a longer than
1655 - Link-local IP address negotiation:
1656 Negotiate with other link-local clients on the local network
1657 for an address that doesn't require explicit configuration.
1658 This is especially useful if a DHCP server cannot be guaranteed
1659 to exist in all environments that the device must operate.
1661 See doc/README.link-local for more information.
1664 CONFIG_CDP_DEVICE_ID
1666 The device id used in CDP trigger frames.
1668 CONFIG_CDP_DEVICE_ID_PREFIX
1670 A two character string which is prefixed to the MAC address
1675 A printf format string which contains the ascii name of
1676 the port. Normally is set to "eth%d" which sets
1677 eth0 for the first Ethernet, eth1 for the second etc.
1679 CONFIG_CDP_CAPABILITIES
1681 A 32bit integer which indicates the device capabilities;
1682 0x00000010 for a normal host which does not forwards.
1686 An ascii string containing the version of the software.
1690 An ascii string containing the name of the platform.
1694 A 32bit integer sent on the trigger.
1696 CONFIG_CDP_POWER_CONSUMPTION
1698 A 16bit integer containing the power consumption of the
1699 device in .1 of milliwatts.
1701 CONFIG_CDP_APPLIANCE_VLAN_TYPE
1703 A byte containing the id of the VLAN.
1705 - Status LED: CONFIG_STATUS_LED
1707 Several configurations allow to display the current
1708 status using a LED. For instance, the LED will blink
1709 fast while running U-Boot code, stop blinking as
1710 soon as a reply to a BOOTP request was received, and
1711 start blinking slow once the Linux kernel is running
1712 (supported by a status LED driver in the Linux
1713 kernel). Defining CONFIG_STATUS_LED enables this
1716 - CAN Support: CONFIG_CAN_DRIVER
1718 Defining CONFIG_CAN_DRIVER enables CAN driver support
1719 on those systems that support this (optional)
1720 feature, like the TQM8xxL modules.
1722 - I2C Support: CONFIG_HARD_I2C | CONFIG_SOFT_I2C
1724 These enable I2C serial bus commands. Defining either of
1725 (but not both of) CONFIG_HARD_I2C or CONFIG_SOFT_I2C will
1726 include the appropriate I2C driver for the selected CPU.
1728 This will allow you to use i2c commands at the u-boot
1729 command line (as long as you set CONFIG_CMD_I2C in
1730 CONFIG_COMMANDS) and communicate with i2c based realtime
1731 clock chips. See common/cmd_i2c.c for a description of the
1732 command line interface.
1734 CONFIG_HARD_I2C selects a hardware I2C controller.
1736 CONFIG_SOFT_I2C configures u-boot to use a software (aka
1737 bit-banging) driver instead of CPM or similar hardware
1740 There are several other quantities that must also be
1741 defined when you define CONFIG_HARD_I2C or CONFIG_SOFT_I2C.
1743 In both cases you will need to define CONFIG_SYS_I2C_SPEED
1744 to be the frequency (in Hz) at which you wish your i2c bus
1745 to run and CONFIG_SYS_I2C_SLAVE to be the address of this node (ie
1746 the CPU's i2c node address).
1748 Now, the u-boot i2c code for the mpc8xx
1749 (arch/powerpc/cpu/mpc8xx/i2c.c) sets the CPU up as a master node
1750 and so its address should therefore be cleared to 0 (See,
1751 eg, MPC823e User's Manual p.16-473). So, set
1752 CONFIG_SYS_I2C_SLAVE to 0.
1754 CONFIG_SYS_I2C_INIT_MPC5XXX
1756 When a board is reset during an i2c bus transfer
1757 chips might think that the current transfer is still
1758 in progress. Reset the slave devices by sending start
1759 commands until the slave device responds.
1761 That's all that's required for CONFIG_HARD_I2C.
1763 If you use the software i2c interface (CONFIG_SOFT_I2C)
1764 then the following macros need to be defined (examples are
1765 from include/configs/lwmon.h):
1769 (Optional). Any commands necessary to enable the I2C
1770 controller or configure ports.
1772 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
1776 (Only for MPC8260 CPU). The I/O port to use (the code
1777 assumes both bits are on the same port). Valid values
1778 are 0..3 for ports A..D.
1782 The code necessary to make the I2C data line active
1783 (driven). If the data line is open collector, this
1786 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
1790 The code necessary to make the I2C data line tri-stated
1791 (inactive). If the data line is open collector, this
1794 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
1798 Code that returns TRUE if the I2C data line is high,
1801 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
1805 If <bit> is TRUE, sets the I2C data line high. If it
1806 is FALSE, it clears it (low).
1808 eg: #define I2C_SDA(bit) \
1809 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
1810 else immr->im_cpm.cp_pbdat &= ~PB_SDA
1814 If <bit> is TRUE, sets the I2C clock line high. If it
1815 is FALSE, it clears it (low).
1817 eg: #define I2C_SCL(bit) \
1818 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
1819 else immr->im_cpm.cp_pbdat &= ~PB_SCL
1823 This delay is invoked four times per clock cycle so this
1824 controls the rate of data transfer. The data rate thus
1825 is 1 / (I2C_DELAY * 4). Often defined to be something
1828 #define I2C_DELAY udelay(2)
1830 CONFIG_SOFT_I2C_GPIO_SCL / CONFIG_SOFT_I2C_GPIO_SDA
1832 If your arch supports the generic GPIO framework (asm/gpio.h),
1833 then you may alternatively define the two GPIOs that are to be
1834 used as SCL / SDA. Any of the previous I2C_xxx macros will
1835 have GPIO-based defaults assigned to them as appropriate.
1837 You should define these to the GPIO value as given directly to
1838 the generic GPIO functions.
1840 CONFIG_SYS_I2C_INIT_BOARD
1842 When a board is reset during an i2c bus transfer
1843 chips might think that the current transfer is still
1844 in progress. On some boards it is possible to access
1845 the i2c SCLK line directly, either by using the
1846 processor pin as a GPIO or by having a second pin
1847 connected to the bus. If this option is defined a
1848 custom i2c_init_board() routine in boards/xxx/board.c
1849 is run early in the boot sequence.
1851 CONFIG_SYS_I2C_BOARD_LATE_INIT
1853 An alternative to CONFIG_SYS_I2C_INIT_BOARD. If this option is
1854 defined a custom i2c_board_late_init() routine in
1855 boards/xxx/board.c is run AFTER the operations in i2c_init()
1856 is completed. This callpoint can be used to unreset i2c bus
1857 using CPU i2c controller register accesses for CPUs whose i2c
1858 controller provide such a method. It is called at the end of
1859 i2c_init() to allow i2c_init operations to setup the i2c bus
1860 controller on the CPU (e.g. setting bus speed & slave address).
1862 CONFIG_I2CFAST (PPC405GP|PPC405EP only)
1864 This option enables configuration of bi_iic_fast[] flags
1865 in u-boot bd_info structure based on u-boot environment
1866 variable "i2cfast". (see also i2cfast)
1868 CONFIG_I2C_MULTI_BUS
1870 This option allows the use of multiple I2C buses, each of which
1871 must have a controller. At any point in time, only one bus is
1872 active. To switch to a different bus, use the 'i2c dev' command.
1873 Note that bus numbering is zero-based.
1875 CONFIG_SYS_I2C_NOPROBES
1877 This option specifies a list of I2C devices that will be skipped
1878 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS
1879 is set, specify a list of bus-device pairs. Otherwise, specify
1880 a 1D array of device addresses
1883 #undef CONFIG_I2C_MULTI_BUS
1884 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68}
1886 will skip addresses 0x50 and 0x68 on a board with one I2C bus
1888 #define CONFIG_I2C_MULTI_BUS
1889 #define CONFIG_SYS_I2C_MULTI_NOPROBES {{0,0x50},{0,0x68},{1,0x54}}
1891 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1
1893 CONFIG_SYS_SPD_BUS_NUM
1895 If defined, then this indicates the I2C bus number for DDR SPD.
1896 If not defined, then U-Boot assumes that SPD is on I2C bus 0.
1898 CONFIG_SYS_RTC_BUS_NUM
1900 If defined, then this indicates the I2C bus number for the RTC.
1901 If not defined, then U-Boot assumes that RTC is on I2C bus 0.
1903 CONFIG_SYS_DTT_BUS_NUM
1905 If defined, then this indicates the I2C bus number for the DTT.
1906 If not defined, then U-Boot assumes that DTT is on I2C bus 0.
1908 CONFIG_SYS_I2C_DTT_ADDR:
1910 If defined, specifies the I2C address of the DTT device.
1911 If not defined, then U-Boot uses predefined value for
1912 specified DTT device.
1916 Define this option if you want to use Freescale's I2C driver in
1917 drivers/i2c/fsl_i2c.c.
1921 Define this option if you have I2C devices reached over 1 .. n
1922 I2C Muxes like the pca9544a. This option addes a new I2C
1923 Command "i2c bus [muxtype:muxaddr:muxchannel]" which adds a
1924 new I2C Bus to the existing I2C Busses. If you select the
1925 new Bus with "i2c dev", u-bbot sends first the commandos for
1926 the muxes to activate this new "bus".
1928 CONFIG_I2C_MULTI_BUS must be also defined, to use this
1932 Adding a new I2C Bus reached over 2 pca9544a muxes
1933 The First mux with address 70 and channel 6
1934 The Second mux with address 71 and channel 4
1936 => i2c bus pca9544a:70:6:pca9544a:71:4
1938 Use the "i2c bus" command without parameter, to get a list
1939 of I2C Busses with muxes:
1942 Busses reached over muxes:
1944 reached over Mux(es):
1947 reached over Mux(es):
1952 If you now switch to the new I2C Bus 3 with "i2c dev 3"
1953 u-boot first sends the command to the mux@70 to enable
1954 channel 6, and then the command to the mux@71 to enable
1957 After that, you can use the "normal" i2c commands as
1958 usual to communicate with your I2C devices behind
1961 This option is actually implemented for the bitbanging
1962 algorithm in common/soft_i2c.c and for the Hardware I2C
1963 Bus on the MPC8260. But it should be not so difficult
1964 to add this option to other architectures.
1966 CONFIG_SOFT_I2C_READ_REPEATED_START
1968 defining this will force the i2c_read() function in
1969 the soft_i2c driver to perform an I2C repeated start
1970 between writing the address pointer and reading the
1971 data. If this define is omitted the default behaviour
1972 of doing a stop-start sequence will be used. Most I2C
1973 devices can use either method, but some require one or
1976 - SPI Support: CONFIG_SPI
1978 Enables SPI driver (so far only tested with
1979 SPI EEPROM, also an instance works with Crystal A/D and
1980 D/As on the SACSng board)
1984 Enables the driver for SPI controller on SuperH. Currently
1985 only SH7757 is supported.
1989 Enables extended (16-bit) SPI EEPROM addressing.
1990 (symmetrical to CONFIG_I2C_X)
1994 Enables a software (bit-bang) SPI driver rather than
1995 using hardware support. This is a general purpose
1996 driver that only requires three general I/O port pins
1997 (two outputs, one input) to function. If this is
1998 defined, the board configuration must define several
1999 SPI configuration items (port pins to use, etc). For
2000 an example, see include/configs/sacsng.h.
2004 Enables a hardware SPI driver for general-purpose reads
2005 and writes. As with CONFIG_SOFT_SPI, the board configuration
2006 must define a list of chip-select function pointers.
2007 Currently supported on some MPC8xxx processors. For an
2008 example, see include/configs/mpc8349emds.h.
2012 Enables the driver for the SPI controllers on i.MX and MXC
2013 SoCs. Currently i.MX31/35/51 are supported.
2015 - FPGA Support: CONFIG_FPGA
2017 Enables FPGA subsystem.
2019 CONFIG_FPGA_<vendor>
2021 Enables support for specific chip vendors.
2024 CONFIG_FPGA_<family>
2026 Enables support for FPGA family.
2027 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX)
2031 Specify the number of FPGA devices to support.
2033 CONFIG_SYS_FPGA_PROG_FEEDBACK
2035 Enable printing of hash marks during FPGA configuration.
2037 CONFIG_SYS_FPGA_CHECK_BUSY
2039 Enable checks on FPGA configuration interface busy
2040 status by the configuration function. This option
2041 will require a board or device specific function to
2046 If defined, a function that provides delays in the FPGA
2047 configuration driver.
2049 CONFIG_SYS_FPGA_CHECK_CTRLC
2050 Allow Control-C to interrupt FPGA configuration
2052 CONFIG_SYS_FPGA_CHECK_ERROR
2054 Check for configuration errors during FPGA bitfile
2055 loading. For example, abort during Virtex II
2056 configuration if the INIT_B line goes low (which
2057 indicated a CRC error).
2059 CONFIG_SYS_FPGA_WAIT_INIT
2061 Maximum time to wait for the INIT_B line to deassert
2062 after PROB_B has been deasserted during a Virtex II
2063 FPGA configuration sequence. The default time is 500
2066 CONFIG_SYS_FPGA_WAIT_BUSY
2068 Maximum time to wait for BUSY to deassert during
2069 Virtex II FPGA configuration. The default is 5 ms.
2071 CONFIG_SYS_FPGA_WAIT_CONFIG
2073 Time to wait after FPGA configuration. The default is
2076 - Configuration Management:
2079 If defined, this string will be added to the U-Boot
2080 version information (U_BOOT_VERSION)
2082 - Vendor Parameter Protection:
2084 U-Boot considers the values of the environment
2085 variables "serial#" (Board Serial Number) and
2086 "ethaddr" (Ethernet Address) to be parameters that
2087 are set once by the board vendor / manufacturer, and
2088 protects these variables from casual modification by
2089 the user. Once set, these variables are read-only,
2090 and write or delete attempts are rejected. You can
2091 change this behaviour:
2093 If CONFIG_ENV_OVERWRITE is #defined in your config
2094 file, the write protection for vendor parameters is
2095 completely disabled. Anybody can change or delete
2098 Alternatively, if you #define _both_ CONFIG_ETHADDR
2099 _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
2100 Ethernet address is installed in the environment,
2101 which can be changed exactly ONCE by the user. [The
2102 serial# is unaffected by this, i. e. it remains
2108 Define this variable to enable the reservation of
2109 "protected RAM", i. e. RAM which is not overwritten
2110 by U-Boot. Define CONFIG_PRAM to hold the number of
2111 kB you want to reserve for pRAM. You can overwrite
2112 this default value by defining an environment
2113 variable "pram" to the number of kB you want to
2114 reserve. Note that the board info structure will
2115 still show the full amount of RAM. If pRAM is
2116 reserved, a new environment variable "mem" will
2117 automatically be defined to hold the amount of
2118 remaining RAM in a form that can be passed as boot
2119 argument to Linux, for instance like that:
2121 setenv bootargs ... mem=\${mem}
2124 This way you can tell Linux not to use this memory,
2125 either, which results in a memory region that will
2126 not be affected by reboots.
2128 *WARNING* If your board configuration uses automatic
2129 detection of the RAM size, you must make sure that
2130 this memory test is non-destructive. So far, the
2131 following board configurations are known to be
2134 ETX094, IVMS8, IVML24, SPD8xx, TQM8xxL,
2135 HERMES, IP860, RPXlite, LWMON, LANTEC,
2141 Define this variable to stop the system in case of a
2142 fatal error, so that you have to reset it manually.
2143 This is probably NOT a good idea for an embedded
2144 system where you want the system to reboot
2145 automatically as fast as possible, but it may be
2146 useful during development since you can try to debug
2147 the conditions that lead to the situation.
2149 CONFIG_NET_RETRY_COUNT
2151 This variable defines the number of retries for
2152 network operations like ARP, RARP, TFTP, or BOOTP
2153 before giving up the operation. If not defined, a
2154 default value of 5 is used.
2158 Timeout waiting for an ARP reply in milliseconds.
2162 Timeout in milliseconds used in NFS protocol.
2163 If you encounter "ERROR: Cannot umount" in nfs command,
2164 try longer timeout such as
2165 #define CONFIG_NFS_TIMEOUT 10000UL
2167 - Command Interpreter:
2168 CONFIG_AUTO_COMPLETE
2170 Enable auto completion of commands using TAB.
2172 Note that this feature has NOT been implemented yet
2173 for the "hush" shell.
2176 CONFIG_SYS_HUSH_PARSER
2178 Define this variable to enable the "hush" shell (from
2179 Busybox) as command line interpreter, thus enabling
2180 powerful command line syntax like
2181 if...then...else...fi conditionals or `&&' and '||'
2182 constructs ("shell scripts").
2184 If undefined, you get the old, much simpler behaviour
2185 with a somewhat smaller memory footprint.
2188 CONFIG_SYS_PROMPT_HUSH_PS2
2190 This defines the secondary prompt string, which is
2191 printed when the command interpreter needs more input
2192 to complete a command. Usually "> ".
2196 In the current implementation, the local variables
2197 space and global environment variables space are
2198 separated. Local variables are those you define by
2199 simply typing `name=value'. To access a local
2200 variable later on, you have write `$name' or
2201 `${name}'; to execute the contents of a variable
2202 directly type `$name' at the command prompt.
2204 Global environment variables are those you use
2205 setenv/printenv to work with. To run a command stored
2206 in such a variable, you need to use the run command,
2207 and you must not use the '$' sign to access them.
2209 To store commands and special characters in a
2210 variable, please use double quotation marks
2211 surrounding the whole text of the variable, instead
2212 of the backslashes before semicolons and special
2215 - Commandline Editing and History:
2216 CONFIG_CMDLINE_EDITING
2218 Enable editing and History functions for interactive
2219 commandline input operations
2221 - Default Environment:
2222 CONFIG_EXTRA_ENV_SETTINGS
2224 Define this to contain any number of null terminated
2225 strings (variable = value pairs) that will be part of
2226 the default environment compiled into the boot image.
2228 For example, place something like this in your
2229 board's config file:
2231 #define CONFIG_EXTRA_ENV_SETTINGS \
2235 Warning: This method is based on knowledge about the
2236 internal format how the environment is stored by the
2237 U-Boot code. This is NOT an official, exported
2238 interface! Although it is unlikely that this format
2239 will change soon, there is no guarantee either.
2240 You better know what you are doing here.
2242 Note: overly (ab)use of the default environment is
2243 discouraged. Make sure to check other ways to preset
2244 the environment like the "source" command or the
2247 CONFIG_ENV_VARS_UBOOT_CONFIG
2249 Define this in order to add variables describing the
2250 U-Boot build configuration to the default environment.
2251 These will be named arch, cpu, board, vendor, and soc.
2253 Enabling this option will cause the following to be defined:
2261 - DataFlash Support:
2262 CONFIG_HAS_DATAFLASH
2264 Defining this option enables DataFlash features and
2265 allows to read/write in Dataflash via the standard
2268 - Serial Flash support
2271 Defining this option enables SPI flash commands
2272 'sf probe/read/write/erase/update'.
2274 Usage requires an initial 'probe' to define the serial
2275 flash parameters, followed by read/write/erase/update
2278 The following defaults may be provided by the platform
2279 to handle the common case when only a single serial
2280 flash is present on the system.
2282 CONFIG_SF_DEFAULT_BUS Bus identifier
2283 CONFIG_SF_DEFAULT_CS Chip-select
2284 CONFIG_SF_DEFAULT_MODE (see include/spi.h)
2285 CONFIG_SF_DEFAULT_SPEED in Hz
2287 - SystemACE Support:
2290 Adding this option adds support for Xilinx SystemACE
2291 chips attached via some sort of local bus. The address
2292 of the chip must also be defined in the
2293 CONFIG_SYS_SYSTEMACE_BASE macro. For example:
2295 #define CONFIG_SYSTEMACE
2296 #define CONFIG_SYS_SYSTEMACE_BASE 0xf0000000
2298 When SystemACE support is added, the "ace" device type
2299 becomes available to the fat commands, i.e. fatls.
2301 - TFTP Fixed UDP Port:
2304 If this is defined, the environment variable tftpsrcp
2305 is used to supply the TFTP UDP source port value.
2306 If tftpsrcp isn't defined, the normal pseudo-random port
2307 number generator is used.
2309 Also, the environment variable tftpdstp is used to supply
2310 the TFTP UDP destination port value. If tftpdstp isn't
2311 defined, the normal port 69 is used.
2313 The purpose for tftpsrcp is to allow a TFTP server to
2314 blindly start the TFTP transfer using the pre-configured
2315 target IP address and UDP port. This has the effect of
2316 "punching through" the (Windows XP) firewall, allowing
2317 the remainder of the TFTP transfer to proceed normally.
2318 A better solution is to properly configure the firewall,
2319 but sometimes that is not allowed.
2321 - Show boot progress:
2322 CONFIG_SHOW_BOOT_PROGRESS
2324 Defining this option allows to add some board-
2325 specific code (calling a user-provided function
2326 "show_boot_progress(int)") that enables you to show
2327 the system's boot progress on some display (for
2328 example, some LED's) on your board. At the moment,
2329 the following checkpoints are implemented:
2331 - Detailed boot stage timing
2333 Define this option to get detailed timing of each stage
2334 of the boot process.
2336 CONFIG_BOOTSTAGE_USER_COUNT
2337 This is the number of available user bootstage records.
2338 Each time you call bootstage_mark(BOOTSTAGE_ID_ALLOC, ...)
2339 a new ID will be allocated from this stash. If you exceed
2340 the limit, recording will stop.
2342 CONFIG_BOOTSTAGE_REPORT
2343 Define this to print a report before boot, similar to this:
2345 Timer summary in microseconds:
2348 3,575,678 3,575,678 board_init_f start
2349 3,575,695 17 arch_cpu_init A9
2350 3,575,777 82 arch_cpu_init done
2351 3,659,598 83,821 board_init_r start
2352 3,910,375 250,777 main_loop
2353 29,916,167 26,005,792 bootm_start
2354 30,361,327 445,160 start_kernel
2356 Legacy uImage format:
2359 1 common/cmd_bootm.c before attempting to boot an image
2360 -1 common/cmd_bootm.c Image header has bad magic number
2361 2 common/cmd_bootm.c Image header has correct magic number
2362 -2 common/cmd_bootm.c Image header has bad checksum
2363 3 common/cmd_bootm.c Image header has correct checksum
2364 -3 common/cmd_bootm.c Image data has bad checksum
2365 4 common/cmd_bootm.c Image data has correct checksum
2366 -4 common/cmd_bootm.c Image is for unsupported architecture
2367 5 common/cmd_bootm.c Architecture check OK
2368 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi)
2369 6 common/cmd_bootm.c Image Type check OK
2370 -6 common/cmd_bootm.c gunzip uncompression error
2371 -7 common/cmd_bootm.c Unimplemented compression type
2372 7 common/cmd_bootm.c Uncompression OK
2373 8 common/cmd_bootm.c No uncompress/copy overwrite error
2374 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX)
2376 9 common/image.c Start initial ramdisk verification
2377 -10 common/image.c Ramdisk header has bad magic number
2378 -11 common/image.c Ramdisk header has bad checksum
2379 10 common/image.c Ramdisk header is OK
2380 -12 common/image.c Ramdisk data has bad checksum
2381 11 common/image.c Ramdisk data has correct checksum
2382 12 common/image.c Ramdisk verification complete, start loading
2383 -13 common/image.c Wrong Image Type (not PPC Linux ramdisk)
2384 13 common/image.c Start multifile image verification
2385 14 common/image.c No initial ramdisk, no multifile, continue.
2387 15 arch/<arch>/lib/bootm.c All preparation done, transferring control to OS
2389 -30 arch/powerpc/lib/board.c Fatal error, hang the system
2390 -31 post/post.c POST test failed, detected by post_output_backlog()
2391 -32 post/post.c POST test failed, detected by post_run_single()
2393 34 common/cmd_doc.c before loading a Image from a DOC device
2394 -35 common/cmd_doc.c Bad usage of "doc" command
2395 35 common/cmd_doc.c correct usage of "doc" command
2396 -36 common/cmd_doc.c No boot device
2397 36 common/cmd_doc.c correct boot device
2398 -37 common/cmd_doc.c Unknown Chip ID on boot device
2399 37 common/cmd_doc.c correct chip ID found, device available
2400 -38 common/cmd_doc.c Read Error on boot device
2401 38 common/cmd_doc.c reading Image header from DOC device OK
2402 -39 common/cmd_doc.c Image header has bad magic number
2403 39 common/cmd_doc.c Image header has correct magic number
2404 -40 common/cmd_doc.c Error reading Image from DOC device
2405 40 common/cmd_doc.c Image header has correct magic number
2406 41 common/cmd_ide.c before loading a Image from a IDE device
2407 -42 common/cmd_ide.c Bad usage of "ide" command
2408 42 common/cmd_ide.c correct usage of "ide" command
2409 -43 common/cmd_ide.c No boot device
2410 43 common/cmd_ide.c boot device found
2411 -44 common/cmd_ide.c Device not available
2412 44 common/cmd_ide.c Device available
2413 -45 common/cmd_ide.c wrong partition selected
2414 45 common/cmd_ide.c partition selected
2415 -46 common/cmd_ide.c Unknown partition table
2416 46 common/cmd_ide.c valid partition table found
2417 -47 common/cmd_ide.c Invalid partition type
2418 47 common/cmd_ide.c correct partition type
2419 -48 common/cmd_ide.c Error reading Image Header on boot device
2420 48 common/cmd_ide.c reading Image Header from IDE device OK
2421 -49 common/cmd_ide.c Image header has bad magic number
2422 49 common/cmd_ide.c Image header has correct magic number
2423 -50 common/cmd_ide.c Image header has bad checksum
2424 50 common/cmd_ide.c Image header has correct checksum
2425 -51 common/cmd_ide.c Error reading Image from IDE device
2426 51 common/cmd_ide.c reading Image from IDE device OK
2427 52 common/cmd_nand.c before loading a Image from a NAND device
2428 -53 common/cmd_nand.c Bad usage of "nand" command
2429 53 common/cmd_nand.c correct usage of "nand" command
2430 -54 common/cmd_nand.c No boot device
2431 54 common/cmd_nand.c boot device found
2432 -55 common/cmd_nand.c Unknown Chip ID on boot device
2433 55 common/cmd_nand.c correct chip ID found, device available
2434 -56 common/cmd_nand.c Error reading Image Header on boot device
2435 56 common/cmd_nand.c reading Image Header from NAND device OK
2436 -57 common/cmd_nand.c Image header has bad magic number
2437 57 common/cmd_nand.c Image header has correct magic number
2438 -58 common/cmd_nand.c Error reading Image from NAND device
2439 58 common/cmd_nand.c reading Image from NAND device OK
2441 -60 common/env_common.c Environment has a bad CRC, using default
2443 64 net/eth.c starting with Ethernet configuration.
2444 -64 net/eth.c no Ethernet found.
2445 65 net/eth.c Ethernet found.
2447 -80 common/cmd_net.c usage wrong
2448 80 common/cmd_net.c before calling NetLoop()
2449 -81 common/cmd_net.c some error in NetLoop() occurred
2450 81 common/cmd_net.c NetLoop() back without error
2451 -82 common/cmd_net.c size == 0 (File with size 0 loaded)
2452 82 common/cmd_net.c trying automatic boot
2453 83 common/cmd_net.c running "source" command
2454 -83 common/cmd_net.c some error in automatic boot or "source" command
2455 84 common/cmd_net.c end without errors
2460 100 common/cmd_bootm.c Kernel FIT Image has correct format
2461 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format
2462 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration
2463 -101 common/cmd_bootm.c Can't get configuration for kernel subimage
2464 102 common/cmd_bootm.c Kernel unit name specified
2465 -103 common/cmd_bootm.c Can't get kernel subimage node offset
2466 103 common/cmd_bootm.c Found configuration node
2467 104 common/cmd_bootm.c Got kernel subimage node offset
2468 -104 common/cmd_bootm.c Kernel subimage hash verification failed
2469 105 common/cmd_bootm.c Kernel subimage hash verification OK
2470 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture
2471 106 common/cmd_bootm.c Architecture check OK
2472 -106 common/cmd_bootm.c Kernel subimage has wrong type
2473 107 common/cmd_bootm.c Kernel subimage type OK
2474 -107 common/cmd_bootm.c Can't get kernel subimage data/size
2475 108 common/cmd_bootm.c Got kernel subimage data/size
2476 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT)
2477 -109 common/cmd_bootm.c Can't get kernel subimage type
2478 -110 common/cmd_bootm.c Can't get kernel subimage comp
2479 -111 common/cmd_bootm.c Can't get kernel subimage os
2480 -112 common/cmd_bootm.c Can't get kernel subimage load address
2481 -113 common/cmd_bootm.c Image uncompress/copy overwrite error
2483 120 common/image.c Start initial ramdisk verification
2484 -120 common/image.c Ramdisk FIT image has incorrect format
2485 121 common/image.c Ramdisk FIT image has correct format
2486 122 common/image.c No ramdisk subimage unit name, using configuration
2487 -122 common/image.c Can't get configuration for ramdisk subimage
2488 123 common/image.c Ramdisk unit name specified
2489 -124 common/image.c Can't get ramdisk subimage node offset
2490 125 common/image.c Got ramdisk subimage node offset
2491 -125 common/image.c Ramdisk subimage hash verification failed
2492 126 common/image.c Ramdisk subimage hash verification OK
2493 -126 common/image.c Ramdisk subimage for unsupported architecture
2494 127 common/image.c Architecture check OK
2495 -127 common/image.c Can't get ramdisk subimage data/size
2496 128 common/image.c Got ramdisk subimage data/size
2497 129 common/image.c Can't get ramdisk load address
2498 -129 common/image.c Got ramdisk load address
2500 -130 common/cmd_doc.c Incorrect FIT image format
2501 131 common/cmd_doc.c FIT image format OK
2503 -140 common/cmd_ide.c Incorrect FIT image format
2504 141 common/cmd_ide.c FIT image format OK
2506 -150 common/cmd_nand.c Incorrect FIT image format
2507 151 common/cmd_nand.c FIT image format OK
2509 - Standalone program support:
2510 CONFIG_STANDALONE_LOAD_ADDR
2512 This option defines a board specific value for the
2513 address where standalone program gets loaded, thus
2514 overwriting the architecture dependent default
2517 - Frame Buffer Address:
2520 Define CONFIG_FB_ADDR if you want to use specific
2521 address for frame buffer.
2522 Then system will reserve the frame buffer address to
2523 defined address instead of lcd_setmem (this function
2524 grabs the memory for frame buffer by panel's size).
2526 Please see board_init_f function.
2528 - Automatic software updates via TFTP server
2530 CONFIG_UPDATE_TFTP_CNT_MAX
2531 CONFIG_UPDATE_TFTP_MSEC_MAX
2533 These options enable and control the auto-update feature;
2534 for a more detailed description refer to doc/README.update.
2536 - MTD Support (mtdparts command, UBI support)
2539 Adds the MTD device infrastructure from the Linux kernel.
2540 Needed for mtdparts command support.
2542 CONFIG_MTD_PARTITIONS
2544 Adds the MTD partitioning infrastructure from the Linux
2545 kernel. Needed for UBI support.
2549 Enable building of SPL globally.
2552 LDSCRIPT for linking the SPL binary.
2555 Maximum binary size (text, data and rodata) of the SPL binary.
2557 CONFIG_SPL_TEXT_BASE
2558 TEXT_BASE for linking the SPL binary.
2560 CONFIG_SPL_BSS_START_ADDR
2561 Link address for the BSS within the SPL binary.
2563 CONFIG_SPL_BSS_MAX_SIZE
2564 Maximum binary size of the BSS section of the SPL binary.
2567 Adress of the start of the stack SPL will use
2569 CONFIG_SYS_SPL_MALLOC_START
2570 Starting address of the malloc pool used in SPL.
2572 CONFIG_SYS_SPL_MALLOC_SIZE
2573 The size of the malloc pool used in SPL.
2575 CONFIG_SPL_LIBCOMMON_SUPPORT
2576 Support for common/libcommon.o in SPL binary
2578 CONFIG_SPL_LIBDISK_SUPPORT
2579 Support for disk/libdisk.o in SPL binary
2581 CONFIG_SPL_I2C_SUPPORT
2582 Support for drivers/i2c/libi2c.o in SPL binary
2584 CONFIG_SPL_GPIO_SUPPORT
2585 Support for drivers/gpio/libgpio.o in SPL binary
2587 CONFIG_SPL_MMC_SUPPORT
2588 Support for drivers/mmc/libmmc.o in SPL binary
2590 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_SECTOR,
2591 CONFIG_SYS_U_BOOT_MAX_SIZE_SECTORS,
2592 CONFIG_SYS_MMC_SD_FAT_BOOT_PARTITION
2593 Address, size and partition on the MMC to load U-Boot from
2594 when the MMC is being used in raw mode.
2596 CONFIG_SPL_FAT_SUPPORT
2597 Support for fs/fat/libfat.o in SPL binary
2599 CONFIG_SPL_FAT_LOAD_PAYLOAD_NAME
2600 Filename to read to load U-Boot when reading from FAT
2602 CONFIG_SPL_NAND_SIMPLE
2603 Support for drivers/mtd/nand/libnand.o in SPL binary
2605 CONFIG_SYS_NAND_5_ADDR_CYCLE, CONFIG_SYS_NAND_PAGE_COUNT,
2606 CONFIG_SYS_NAND_PAGE_SIZE, CONFIG_SYS_NAND_OOBSIZE,
2607 CONFIG_SYS_NAND_BLOCK_SIZE, CONFIG_SYS_NAND_BAD_BLOCK_POS,
2608 CONFIG_SYS_NAND_ECCPOS, CONFIG_SYS_NAND_ECCSIZE,
2609 CONFIG_SYS_NAND_ECCBYTES
2610 Defines the size and behavior of the NAND that SPL uses
2611 to read U-Boot with CONFIG_SPL_NAND_SIMPLE
2613 CONFIG_SYS_NAND_U_BOOT_OFFS
2614 Location in NAND for CONFIG_SPL_NAND_SIMPLE to read U-Boot
2617 CONFIG_SYS_NAND_U_BOOT_START
2618 Location in memory for CONFIG_SPL_NAND_SIMPLE to load U-Boot
2621 CONFIG_SYS_NAND_HW_ECC_OOBFIRST
2622 Define this if you need to first read the OOB and then the
2623 data. This is used for example on davinci plattforms.
2625 CONFIG_SPL_OMAP3_ID_NAND
2626 Support for an OMAP3-specific set of functions to return the
2627 ID and MFR of the first attached NAND chip, if present.
2629 CONFIG_SPL_SERIAL_SUPPORT
2630 Support for drivers/serial/libserial.o in SPL binary
2632 CONFIG_SPL_SPI_FLASH_SUPPORT
2633 Support for drivers/mtd/spi/libspi_flash.o in SPL binary
2635 CONFIG_SPL_SPI_SUPPORT
2636 Support for drivers/spi/libspi.o in SPL binary
2638 CONFIG_SPL_LIBGENERIC_SUPPORT
2639 Support for lib/libgeneric.o in SPL binary
2644 [so far only for SMDK2400 boards]
2646 - Modem support enable:
2647 CONFIG_MODEM_SUPPORT
2649 - RTS/CTS Flow control enable:
2652 - Modem debug support:
2653 CONFIG_MODEM_SUPPORT_DEBUG
2655 Enables debugging stuff (char screen[1024], dbg())
2656 for modem support. Useful only with BDI2000.
2658 - Interrupt support (PPC):
2660 There are common interrupt_init() and timer_interrupt()
2661 for all PPC archs. interrupt_init() calls interrupt_init_cpu()
2662 for CPU specific initialization. interrupt_init_cpu()
2663 should set decrementer_count to appropriate value. If
2664 CPU resets decrementer automatically after interrupt
2665 (ppc4xx) it should set decrementer_count to zero.
2666 timer_interrupt() calls timer_interrupt_cpu() for CPU
2667 specific handling. If board has watchdog / status_led
2668 / other_activity_monitor it works automatically from
2669 general timer_interrupt().
2673 In the target system modem support is enabled when a
2674 specific key (key combination) is pressed during
2675 power-on. Otherwise U-Boot will boot normally
2676 (autoboot). The key_pressed() function is called from
2677 board_init(). Currently key_pressed() is a dummy
2678 function, returning 1 and thus enabling modem
2681 If there are no modem init strings in the
2682 environment, U-Boot proceed to autoboot; the
2683 previous output (banner, info printfs) will be
2686 See also: doc/README.Modem
2688 Board initialization settings:
2689 ------------------------------
2691 During Initialization u-boot calls a number of board specific functions
2692 to allow the preparation of board specific prerequisites, e.g. pin setup
2693 before drivers are initialized. To enable these callbacks the
2694 following configuration macros have to be defined. Currently this is
2695 architecture specific, so please check arch/your_architecture/lib/board.c
2696 typically in board_init_f() and board_init_r().
2698 - CONFIG_BOARD_EARLY_INIT_F: Call board_early_init_f()
2699 - CONFIG_BOARD_EARLY_INIT_R: Call board_early_init_r()
2700 - CONFIG_BOARD_LATE_INIT: Call board_late_init()
2701 - CONFIG_BOARD_POSTCLK_INIT: Call board_postclk_init()
2703 Configuration Settings:
2704 -----------------------
2706 - CONFIG_SYS_LONGHELP: Defined when you want long help messages included;
2707 undefine this when you're short of memory.
2709 - CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default
2710 width of the commands listed in the 'help' command output.
2712 - CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to
2713 prompt for user input.
2715 - CONFIG_SYS_CBSIZE: Buffer size for input from the Console
2717 - CONFIG_SYS_PBSIZE: Buffer size for Console output
2719 - CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands
2721 - CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to
2722 the application (usually a Linux kernel) when it is
2725 - CONFIG_SYS_BAUDRATE_TABLE:
2726 List of legal baudrate settings for this board.
2728 - CONFIG_SYS_CONSOLE_INFO_QUIET
2729 Suppress display of console information at boot.
2731 - CONFIG_SYS_CONSOLE_IS_IN_ENV
2732 If the board specific function
2733 extern int overwrite_console (void);
2734 returns 1, the stdin, stderr and stdout are switched to the
2735 serial port, else the settings in the environment are used.
2737 - CONFIG_SYS_CONSOLE_OVERWRITE_ROUTINE
2738 Enable the call to overwrite_console().
2740 - CONFIG_SYS_CONSOLE_ENV_OVERWRITE
2741 Enable overwrite of previous console environment settings.
2743 - CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END:
2744 Begin and End addresses of the area used by the
2747 - CONFIG_SYS_ALT_MEMTEST:
2748 Enable an alternate, more extensive memory test.
2750 - CONFIG_SYS_MEMTEST_SCRATCH:
2751 Scratch address used by the alternate memory test
2752 You only need to set this if address zero isn't writeable
2754 - CONFIG_SYS_MEM_TOP_HIDE (PPC only):
2755 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header,
2756 this specified memory area will get subtracted from the top
2757 (end) of RAM and won't get "touched" at all by U-Boot. By
2758 fixing up gd->ram_size the Linux kernel should gets passed
2759 the now "corrected" memory size and won't touch it either.
2760 This should work for arch/ppc and arch/powerpc. Only Linux
2761 board ports in arch/powerpc with bootwrapper support that
2762 recalculate the memory size from the SDRAM controller setup
2763 will have to get fixed in Linux additionally.
2765 This option can be used as a workaround for the 440EPx/GRx
2766 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't
2769 WARNING: Please make sure that this value is a multiple of
2770 the Linux page size (normally 4k). If this is not the case,
2771 then the end address of the Linux memory will be located at a
2772 non page size aligned address and this could cause major
2775 - CONFIG_SYS_TFTP_LOADADDR:
2776 Default load address for network file downloads
2778 - CONFIG_SYS_LOADS_BAUD_CHANGE:
2779 Enable temporary baudrate change while serial download
2781 - CONFIG_SYS_SDRAM_BASE:
2782 Physical start address of SDRAM. _Must_ be 0 here.
2784 - CONFIG_SYS_MBIO_BASE:
2785 Physical start address of Motherboard I/O (if using a
2788 - CONFIG_SYS_FLASH_BASE:
2789 Physical start address of Flash memory.
2791 - CONFIG_SYS_MONITOR_BASE:
2792 Physical start address of boot monitor code (set by
2793 make config files to be same as the text base address
2794 (CONFIG_SYS_TEXT_BASE) used when linking) - same as
2795 CONFIG_SYS_FLASH_BASE when booting from flash.
2797 - CONFIG_SYS_MONITOR_LEN:
2798 Size of memory reserved for monitor code, used to
2799 determine _at_compile_time_ (!) if the environment is
2800 embedded within the U-Boot image, or in a separate
2803 - CONFIG_SYS_MALLOC_LEN:
2804 Size of DRAM reserved for malloc() use.
2806 - CONFIG_SYS_BOOTM_LEN:
2807 Normally compressed uImages are limited to an
2808 uncompressed size of 8 MBytes. If this is not enough,
2809 you can define CONFIG_SYS_BOOTM_LEN in your board config file
2810 to adjust this setting to your needs.
2812 - CONFIG_SYS_BOOTMAPSZ:
2813 Maximum size of memory mapped by the startup code of
2814 the Linux kernel; all data that must be processed by
2815 the Linux kernel (bd_info, boot arguments, FDT blob if
2816 used) must be put below this limit, unless "bootm_low"
2817 enviroment variable is defined and non-zero. In such case
2818 all data for the Linux kernel must be between "bootm_low"
2819 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ. The environment
2820 variable "bootm_mapsize" will override the value of
2821 CONFIG_SYS_BOOTMAPSZ. If CONFIG_SYS_BOOTMAPSZ is undefined,
2822 then the value in "bootm_size" will be used instead.
2824 - CONFIG_SYS_BOOT_RAMDISK_HIGH:
2825 Enable initrd_high functionality. If defined then the
2826 initrd_high feature is enabled and the bootm ramdisk subcommand
2829 - CONFIG_SYS_BOOT_GET_CMDLINE:
2830 Enables allocating and saving kernel cmdline in space between
2831 "bootm_low" and "bootm_low" + BOOTMAPSZ.
2833 - CONFIG_SYS_BOOT_GET_KBD:
2834 Enables allocating and saving a kernel copy of the bd_info in
2835 space between "bootm_low" and "bootm_low" + BOOTMAPSZ.
2837 - CONFIG_SYS_MAX_FLASH_BANKS:
2838 Max number of Flash memory banks
2840 - CONFIG_SYS_MAX_FLASH_SECT:
2841 Max number of sectors on a Flash chip
2843 - CONFIG_SYS_FLASH_ERASE_TOUT:
2844 Timeout for Flash erase operations (in ms)
2846 - CONFIG_SYS_FLASH_WRITE_TOUT:
2847 Timeout for Flash write operations (in ms)
2849 - CONFIG_SYS_FLASH_LOCK_TOUT
2850 Timeout for Flash set sector lock bit operation (in ms)
2852 - CONFIG_SYS_FLASH_UNLOCK_TOUT
2853 Timeout for Flash clear lock bits operation (in ms)
2855 - CONFIG_SYS_FLASH_PROTECTION
2856 If defined, hardware flash sectors protection is used
2857 instead of U-Boot software protection.
2859 - CONFIG_SYS_DIRECT_FLASH_TFTP:
2861 Enable TFTP transfers directly to flash memory;
2862 without this option such a download has to be
2863 performed in two steps: (1) download to RAM, and (2)
2864 copy from RAM to flash.
2866 The two-step approach is usually more reliable, since
2867 you can check if the download worked before you erase
2868 the flash, but in some situations (when system RAM is
2869 too limited to allow for a temporary copy of the
2870 downloaded image) this option may be very useful.
2872 - CONFIG_SYS_FLASH_CFI:
2873 Define if the flash driver uses extra elements in the
2874 common flash structure for storing flash geometry.
2876 - CONFIG_FLASH_CFI_DRIVER
2877 This option also enables the building of the cfi_flash driver
2878 in the drivers directory
2880 - CONFIG_FLASH_CFI_MTD
2881 This option enables the building of the cfi_mtd driver
2882 in the drivers directory. The driver exports CFI flash
2885 - CONFIG_SYS_FLASH_USE_BUFFER_WRITE
2886 Use buffered writes to flash.
2888 - CONFIG_FLASH_SPANSION_S29WS_N
2889 s29ws-n MirrorBit flash has non-standard addresses for buffered
2892 - CONFIG_SYS_FLASH_QUIET_TEST
2893 If this option is defined, the common CFI flash doesn't
2894 print it's warning upon not recognized FLASH banks. This
2895 is useful, if some of the configured banks are only
2896 optionally available.
2898 - CONFIG_FLASH_SHOW_PROGRESS
2899 If defined (must be an integer), print out countdown
2900 digits and dots. Recommended value: 45 (9..1) for 80
2901 column displays, 15 (3..1) for 40 column displays.
2903 - CONFIG_SYS_RX_ETH_BUFFER:
2904 Defines the number of Ethernet receive buffers. On some
2905 Ethernet controllers it is recommended to set this value
2906 to 8 or even higher (EEPRO100 or 405 EMAC), since all
2907 buffers can be full shortly after enabling the interface
2908 on high Ethernet traffic.
2909 Defaults to 4 if not defined.
2911 - CONFIG_ENV_MAX_ENTRIES
2913 Maximum number of entries in the hash table that is used
2914 internally to store the environment settings. The default
2915 setting is supposed to be generous and should work in most
2916 cases. This setting can be used to tune behaviour; see
2917 lib/hashtable.c for details.
2919 The following definitions that deal with the placement and management
2920 of environment data (variable area); in general, we support the
2921 following configurations:
2923 - CONFIG_BUILD_ENVCRC:
2925 Builds up envcrc with the target environment so that external utils
2926 may easily extract it and embed it in final U-Boot images.
2928 - CONFIG_ENV_IS_IN_FLASH:
2930 Define this if the environment is in flash memory.
2932 a) The environment occupies one whole flash sector, which is
2933 "embedded" in the text segment with the U-Boot code. This
2934 happens usually with "bottom boot sector" or "top boot
2935 sector" type flash chips, which have several smaller
2936 sectors at the start or the end. For instance, such a
2937 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In
2938 such a case you would place the environment in one of the
2939 4 kB sectors - with U-Boot code before and after it. With
2940 "top boot sector" type flash chips, you would put the
2941 environment in one of the last sectors, leaving a gap
2942 between U-Boot and the environment.
2944 - CONFIG_ENV_OFFSET:
2946 Offset of environment data (variable area) to the
2947 beginning of flash memory; for instance, with bottom boot
2948 type flash chips the second sector can be used: the offset
2949 for this sector is given here.
2951 CONFIG_ENV_OFFSET is used relative to CONFIG_SYS_FLASH_BASE.
2955 This is just another way to specify the start address of
2956 the flash sector containing the environment (instead of
2959 - CONFIG_ENV_SECT_SIZE:
2961 Size of the sector containing the environment.
2964 b) Sometimes flash chips have few, equal sized, BIG sectors.
2965 In such a case you don't want to spend a whole sector for
2970 If you use this in combination with CONFIG_ENV_IS_IN_FLASH
2971 and CONFIG_ENV_SECT_SIZE, you can specify to use only a part
2972 of this flash sector for the environment. This saves
2973 memory for the RAM copy of the environment.
2975 It may also save flash memory if you decide to use this
2976 when your environment is "embedded" within U-Boot code,
2977 since then the remainder of the flash sector could be used
2978 for U-Boot code. It should be pointed out that this is
2979 STRONGLY DISCOURAGED from a robustness point of view:
2980 updating the environment in flash makes it always
2981 necessary to erase the WHOLE sector. If something goes
2982 wrong before the contents has been restored from a copy in
2983 RAM, your target system will be dead.
2985 - CONFIG_ENV_ADDR_REDUND
2986 CONFIG_ENV_SIZE_REDUND
2988 These settings describe a second storage area used to hold
2989 a redundant copy of the environment data, so that there is
2990 a valid backup copy in case there is a power failure during
2991 a "saveenv" operation.
2993 BE CAREFUL! Any changes to the flash layout, and some changes to the
2994 source code will make it necessary to adapt <board>/u-boot.lds*
2998 - CONFIG_ENV_IS_IN_NVRAM:
3000 Define this if you have some non-volatile memory device
3001 (NVRAM, battery buffered SRAM) which you want to use for the
3007 These two #defines are used to determine the memory area you
3008 want to use for environment. It is assumed that this memory
3009 can just be read and written to, without any special
3012 BE CAREFUL! The first access to the environment happens quite early
3013 in U-Boot initalization (when we try to get the setting of for the
3014 console baudrate). You *MUST* have mapped your NVRAM area then, or
3017 Please note that even with NVRAM we still use a copy of the
3018 environment in RAM: we could work on NVRAM directly, but we want to
3019 keep settings there always unmodified except somebody uses "saveenv"
3020 to save the current settings.
3023 - CONFIG_ENV_IS_IN_EEPROM:
3025 Use this if you have an EEPROM or similar serial access
3026 device and a driver for it.
3028 - CONFIG_ENV_OFFSET:
3031 These two #defines specify the offset and size of the
3032 environment area within the total memory of your EEPROM.
3034 - CONFIG_SYS_I2C_EEPROM_ADDR:
3035 If defined, specified the chip address of the EEPROM device.
3036 The default address is zero.
3038 - CONFIG_SYS_EEPROM_PAGE_WRITE_BITS:
3039 If defined, the number of bits used to address bytes in a
3040 single page in the EEPROM device. A 64 byte page, for example
3041 would require six bits.
3043 - CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS:
3044 If defined, the number of milliseconds to delay between
3045 page writes. The default is zero milliseconds.
3047 - CONFIG_SYS_I2C_EEPROM_ADDR_LEN:
3048 The length in bytes of the EEPROM memory array address. Note
3049 that this is NOT the chip address length!
3051 - CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW:
3052 EEPROM chips that implement "address overflow" are ones
3053 like Catalyst 24WC04/08/16 which has 9/10/11 bits of
3054 address and the extra bits end up in the "chip address" bit
3055 slots. This makes a 24WC08 (1Kbyte) chip look like four 256
3058 Note that we consider the length of the address field to
3059 still be one byte because the extra address bits are hidden
3060 in the chip address.
3062 - CONFIG_SYS_EEPROM_SIZE:
3063 The size in bytes of the EEPROM device.
3065 - CONFIG_ENV_EEPROM_IS_ON_I2C
3066 define this, if you have I2C and SPI activated, and your
3067 EEPROM, which holds the environment, is on the I2C bus.
3069 - CONFIG_I2C_ENV_EEPROM_BUS
3070 if you have an Environment on an EEPROM reached over
3071 I2C muxes, you can define here, how to reach this
3072 EEPROM. For example:
3074 #define CONFIG_I2C_ENV_EEPROM_BUS "pca9547:70:d\0"
3076 EEPROM which holds the environment, is reached over
3077 a pca9547 i2c mux with address 0x70, channel 3.
3079 - CONFIG_ENV_IS_IN_DATAFLASH:
3081 Define this if you have a DataFlash memory device which you
3082 want to use for the environment.
3084 - CONFIG_ENV_OFFSET:
3088 These three #defines specify the offset and size of the
3089 environment area within the total memory of your DataFlash placed
3090 at the specified address.
3092 - CONFIG_ENV_IS_IN_REMOTE:
3094 Define this if you have a remote memory space which you
3095 want to use for the local device's environment.
3100 These two #defines specify the address and size of the
3101 environment area within the remote memory space. The
3102 local device can get the environment from remote memory
3103 space by SRIO or other links.
3105 BE CAREFUL! For some special cases, the local device can not use
3106 "saveenv" command. For example, the local device will get the
3107 environment stored in a remote NOR flash by SRIO link, but it can
3108 not erase, write this NOR flash by SRIO interface.
3110 - CONFIG_ENV_IS_IN_NAND:
3112 Define this if you have a NAND device which you want to use
3113 for the environment.
3115 - CONFIG_ENV_OFFSET:
3118 These two #defines specify the offset and size of the environment
3119 area within the first NAND device. CONFIG_ENV_OFFSET must be
3120 aligned to an erase block boundary.
3122 - CONFIG_ENV_OFFSET_REDUND (optional):
3124 This setting describes a second storage area of CONFIG_ENV_SIZE
3125 size used to hold a redundant copy of the environment data, so
3126 that there is a valid backup copy in case there is a power failure
3127 during a "saveenv" operation. CONFIG_ENV_OFFSET_RENDUND must be
3128 aligned to an erase block boundary.
3130 - CONFIG_ENV_RANGE (optional):
3132 Specifies the length of the region in which the environment
3133 can be written. This should be a multiple of the NAND device's
3134 block size. Specifying a range with more erase blocks than
3135 are needed to hold CONFIG_ENV_SIZE allows bad blocks within
3136 the range to be avoided.
3138 - CONFIG_ENV_OFFSET_OOB (optional):
3140 Enables support for dynamically retrieving the offset of the
3141 environment from block zero's out-of-band data. The
3142 "nand env.oob" command can be used to record this offset.
3143 Currently, CONFIG_ENV_OFFSET_REDUND is not supported when
3144 using CONFIG_ENV_OFFSET_OOB.
3146 - CONFIG_NAND_ENV_DST
3148 Defines address in RAM to which the nand_spl code should copy the
3149 environment. If redundant environment is used, it will be copied to
3150 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE.
3152 - CONFIG_SYS_SPI_INIT_OFFSET
3154 Defines offset to the initial SPI buffer area in DPRAM. The
3155 area is used at an early stage (ROM part) if the environment
3156 is configured to reside in the SPI EEPROM: We need a 520 byte
3157 scratch DPRAM area. It is used between the two initialization
3158 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems
3159 to be a good choice since it makes it far enough from the
3160 start of the data area as well as from the stack pointer.
3162 Please note that the environment is read-only until the monitor
3163 has been relocated to RAM and a RAM copy of the environment has been
3164 created; also, when using EEPROM you will have to use getenv_f()
3165 until then to read environment variables.
3167 The environment is protected by a CRC32 checksum. Before the monitor
3168 is relocated into RAM, as a result of a bad CRC you will be working
3169 with the compiled-in default environment - *silently*!!! [This is
3170 necessary, because the first environment variable we need is the
3171 "baudrate" setting for the console - if we have a bad CRC, we don't
3172 have any device yet where we could complain.]
3174 Note: once the monitor has been relocated, then it will complain if
3175 the default environment is used; a new CRC is computed as soon as you
3176 use the "saveenv" command to store a valid environment.
3178 - CONFIG_SYS_FAULT_ECHO_LINK_DOWN:
3179 Echo the inverted Ethernet link state to the fault LED.
3181 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR
3182 also needs to be defined.
3184 - CONFIG_SYS_FAULT_MII_ADDR:
3185 MII address of the PHY to check for the Ethernet link state.
3187 - CONFIG_NS16550_MIN_FUNCTIONS:
3188 Define this if you desire to only have use of the NS16550_init
3189 and NS16550_putc functions for the serial driver located at
3190 drivers/serial/ns16550.c. This option is useful for saving
3191 space for already greatly restricted images, including but not
3192 limited to NAND_SPL configurations.
3194 Low Level (hardware related) configuration options:
3195 ---------------------------------------------------
3197 - CONFIG_SYS_CACHELINE_SIZE:
3198 Cache Line Size of the CPU.
3200 - CONFIG_SYS_DEFAULT_IMMR:
3201 Default address of the IMMR after system reset.
3203 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU,
3204 and RPXsuper) to be able to adjust the position of
3205 the IMMR register after a reset.
3207 - CONFIG_SYS_CCSRBAR_DEFAULT:
3208 Default (power-on reset) physical address of CCSR on Freescale
3211 - CONFIG_SYS_CCSRBAR:
3212 Virtual address of CCSR. On a 32-bit build, this is typically
3213 the same value as CONFIG_SYS_CCSRBAR_DEFAULT.
3215 CONFIG_SYS_DEFAULT_IMMR must also be set to this value,
3216 for cross-platform code that uses that macro instead.
3218 - CONFIG_SYS_CCSRBAR_PHYS:
3219 Physical address of CCSR. CCSR can be relocated to a new
3220 physical address, if desired. In this case, this macro should
3221 be set to that address. Otherwise, it should be set to the
3222 same value as CONFIG_SYS_CCSRBAR_DEFAULT. For example, CCSR
3223 is typically relocated on 36-bit builds. It is recommended
3224 that this macro be defined via the _HIGH and _LOW macros:
3226 #define CONFIG_SYS_CCSRBAR_PHYS ((CONFIG_SYS_CCSRBAR_PHYS_HIGH
3227 * 1ull) << 32 | CONFIG_SYS_CCSRBAR_PHYS_LOW)
3229 - CONFIG_SYS_CCSRBAR_PHYS_HIGH:
3230 Bits 33-36 of CONFIG_SYS_CCSRBAR_PHYS. This value is typically
3231 either 0 (32-bit build) or 0xF (36-bit build). This macro is
3232 used in assembly code, so it must not contain typecasts or
3233 integer size suffixes (e.g. "ULL").
3235 - CONFIG_SYS_CCSRBAR_PHYS_LOW:
3236 Lower 32-bits of CONFIG_SYS_CCSRBAR_PHYS. This macro is
3237 used in assembly code, so it must not contain typecasts or
3238 integer size suffixes (e.g. "ULL").
3240 - CONFIG_SYS_CCSR_DO_NOT_RELOCATE:
3241 If this macro is defined, then CONFIG_SYS_CCSRBAR_PHYS will be
3242 forced to a value that ensures that CCSR is not relocated.
3244 - Floppy Disk Support:
3245 CONFIG_SYS_FDC_DRIVE_NUMBER
3247 the default drive number (default value 0)
3249 CONFIG_SYS_ISA_IO_STRIDE
3251 defines the spacing between FDC chipset registers
3254 CONFIG_SYS_ISA_IO_OFFSET
3256 defines the offset of register from address. It
3257 depends on which part of the data bus is connected to
3258 the FDC chipset. (default value 0)
3260 If CONFIG_SYS_ISA_IO_STRIDE CONFIG_SYS_ISA_IO_OFFSET and
3261 CONFIG_SYS_FDC_DRIVE_NUMBER are undefined, they take their
3264 if CONFIG_SYS_FDC_HW_INIT is defined, then the function
3265 fdc_hw_init() is called at the beginning of the FDC
3266 setup. fdc_hw_init() must be provided by the board
3267 source code. It is used to make hardware dependant
3271 Most IDE controllers were designed to be connected with PCI
3272 interface. Only few of them were designed for AHB interface.
3273 When software is doing ATA command and data transfer to
3274 IDE devices through IDE-AHB controller, some additional
3275 registers accessing to these kind of IDE-AHB controller
3278 - CONFIG_SYS_IMMR: Physical address of the Internal Memory.
3279 DO NOT CHANGE unless you know exactly what you're
3280 doing! (11-4) [MPC8xx/82xx systems only]
3282 - CONFIG_SYS_INIT_RAM_ADDR:
3284 Start address of memory area that can be used for
3285 initial data and stack; please note that this must be
3286 writable memory that is working WITHOUT special
3287 initialization, i. e. you CANNOT use normal RAM which
3288 will become available only after programming the
3289 memory controller and running certain initialization
3292 U-Boot uses the following memory types:
3293 - MPC8xx and MPC8260: IMMR (internal memory of the CPU)
3294 - MPC824X: data cache
3295 - PPC4xx: data cache
3297 - CONFIG_SYS_GBL_DATA_OFFSET:
3299 Offset of the initial data structure in the memory
3300 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually
3301 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial
3302 data is located at the end of the available space
3303 (sometimes written as (CONFIG_SYS_INIT_RAM_SIZE -
3304 CONFIG_SYS_INIT_DATA_SIZE), and the initial stack is just
3305 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR +
3306 CONFIG_SYS_GBL_DATA_OFFSET) downward.
3309 On the MPC824X (or other systems that use the data
3310 cache for initial memory) the address chosen for
3311 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must
3312 point to an otherwise UNUSED address space between
3313 the top of RAM and the start of the PCI space.
3315 - CONFIG_SYS_SIUMCR: SIU Module Configuration (11-6)
3317 - CONFIG_SYS_SYPCR: System Protection Control (11-9)
3319 - CONFIG_SYS_TBSCR: Time Base Status and Control (11-26)
3321 - CONFIG_SYS_PISCR: Periodic Interrupt Status and Control (11-31)
3323 - CONFIG_SYS_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30)
3325 - CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27)
3327 - CONFIG_SYS_OR_TIMING_SDRAM:
3330 - CONFIG_SYS_MAMR_PTA:
3331 periodic timer for refresh
3333 - CONFIG_SYS_DER: Debug Event Register (37-47)
3335 - FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM,
3336 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP,
3337 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM,
3338 CONFIG_SYS_BR1_PRELIM:
3339 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
3341 - SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
3342 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM,
3343 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM:
3344 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
3346 - CONFIG_SYS_MAMR_PTA, CONFIG_SYS_MPTPR_2BK_4K, CONFIG_SYS_MPTPR_1BK_4K, CONFIG_SYS_MPTPR_2BK_8K,
3347 CONFIG_SYS_MPTPR_1BK_8K, CONFIG_SYS_MAMR_8COL, CONFIG_SYS_MAMR_9COL:
3348 Machine Mode Register and Memory Periodic Timer
3349 Prescaler definitions (SDRAM timing)
3351 - CONFIG_SYS_I2C_UCODE_PATCH, CONFIG_SYS_I2C_DPMEM_OFFSET [0x1FC0]:
3352 enable I2C microcode relocation patch (MPC8xx);
3353 define relocation offset in DPRAM [DSP2]
3355 - CONFIG_SYS_SMC_UCODE_PATCH, CONFIG_SYS_SMC_DPMEM_OFFSET [0x1FC0]:
3356 enable SMC microcode relocation patch (MPC8xx);
3357 define relocation offset in DPRAM [SMC1]
3359 - CONFIG_SYS_SPI_UCODE_PATCH, CONFIG_SYS_SPI_DPMEM_OFFSET [0x1FC0]:
3360 enable SPI microcode relocation patch (MPC8xx);
3361 define relocation offset in DPRAM [SCC4]
3363 - CONFIG_SYS_USE_OSCCLK:
3364 Use OSCM clock mode on MBX8xx board. Be careful,
3365 wrong setting might damage your board. Read
3366 doc/README.MBX before setting this variable!
3368 - CONFIG_SYS_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only)
3369 Offset of the bootmode word in DPRAM used by post
3370 (Power On Self Tests). This definition overrides
3371 #define'd default value in commproc.h resp.
3374 - CONFIG_SYS_PCI_SLV_MEM_LOCAL, CONFIG_SYS_PCI_SLV_MEM_BUS, CONFIG_SYS_PICMR0_MASK_ATTRIB,
3375 CONFIG_SYS_PCI_MSTR0_LOCAL, CONFIG_SYS_PCIMSK0_MASK, CONFIG_SYS_PCI_MSTR1_LOCAL,
3376 CONFIG_SYS_PCIMSK1_MASK, CONFIG_SYS_PCI_MSTR_MEM_LOCAL, CONFIG_SYS_PCI_MSTR_MEM_BUS,
3377 CONFIG_SYS_CPU_PCI_MEM_START, CONFIG_SYS_PCI_MSTR_MEM_SIZE, CONFIG_SYS_POCMR0_MASK_ATTRIB,
3378 CONFIG_SYS_PCI_MSTR_MEMIO_LOCAL, CONFIG_SYS_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START,
3379 CONFIG_SYS_PCI_MSTR_MEMIO_SIZE, CONFIG_SYS_POCMR1_MASK_ATTRIB, CONFIG_SYS_PCI_MSTR_IO_LOCAL,
3380 CONFIG_SYS_PCI_MSTR_IO_BUS, CONFIG_SYS_CPU_PCI_IO_START, CONFIG_SYS_PCI_MSTR_IO_SIZE,
3381 CONFIG_SYS_POCMR2_MASK_ATTRIB: (MPC826x only)
3382 Overrides the default PCI memory map in arch/powerpc/cpu/mpc8260/pci.c if set.
3384 - CONFIG_PCI_DISABLE_PCIE:
3385 Disable PCI-Express on systems where it is supported but not
3388 - CONFIG_PCI_ENUM_ONLY
3389 Only scan through and get the devices on the busses.
3390 Don't do any setup work, presumably because someone or
3391 something has already done it, and we don't need to do it
3392 a second time. Useful for platforms that are pre-booted
3393 by coreboot or similar.
3396 Chip has SRIO or not
3399 Board has SRIO 1 port available
3402 Board has SRIO 2 port available
3404 - CONFIG_SYS_SRIOn_MEM_VIRT:
3405 Virtual Address of SRIO port 'n' memory region
3407 - CONFIG_SYS_SRIOn_MEM_PHYS:
3408 Physical Address of SRIO port 'n' memory region
3410 - CONFIG_SYS_SRIOn_MEM_SIZE:
3411 Size of SRIO port 'n' memory region
3413 - CONFIG_SYS_NDFC_16
3414 Defined to tell the NDFC that the NAND chip is using a
3417 - CONFIG_SYS_NDFC_EBC0_CFG
3418 Sets the EBC0_CFG register for the NDFC. If not defined
3419 a default value will be used.
3422 Get DDR timing information from an I2C EEPROM. Common
3423 with pluggable memory modules such as SODIMMs
3426 I2C address of the SPD EEPROM
3428 - CONFIG_SYS_SPD_BUS_NUM
3429 If SPD EEPROM is on an I2C bus other than the first
3430 one, specify here. Note that the value must resolve
3431 to something your driver can deal with.
3433 - CONFIG_SYS_DDR_RAW_TIMING
3434 Get DDR timing information from other than SPD. Common with
3435 soldered DDR chips onboard without SPD. DDR raw timing
3436 parameters are extracted from datasheet and hard-coded into
3437 header files or board specific files.
3439 - CONFIG_FSL_DDR_INTERACTIVE
3440 Enable interactive DDR debugging. See doc/README.fsl-ddr.
3442 - CONFIG_SYS_83XX_DDR_USES_CS0
3443 Only for 83xx systems. If specified, then DDR should
3444 be configured using CS0 and CS1 instead of CS2 and CS3.
3446 - CONFIG_ETHER_ON_FEC[12]
3447 Define to enable FEC[12] on a 8xx series processor.
3449 - CONFIG_FEC[12]_PHY
3450 Define to the hardcoded PHY address which corresponds
3451 to the given FEC; i. e.
3452 #define CONFIG_FEC1_PHY 4
3453 means that the PHY with address 4 is connected to FEC1
3455 When set to -1, means to probe for first available.
3457 - CONFIG_FEC[12]_PHY_NORXERR
3458 The PHY does not have a RXERR line (RMII only).
3459 (so program the FEC to ignore it).
3462 Enable RMII mode for all FECs.
3463 Note that this is a global option, we can't
3464 have one FEC in standard MII mode and another in RMII mode.
3466 - CONFIG_CRC32_VERIFY
3467 Add a verify option to the crc32 command.
3470 => crc32 -v <address> <count> <crc32>
3472 Where address/count indicate a memory area
3473 and crc32 is the correct crc32 which the
3477 Add the "loopw" memory command. This only takes effect if
3478 the memory commands are activated globally (CONFIG_CMD_MEM).
3481 Add the "mdc" and "mwc" memory commands. These are cyclic
3486 This command will print 4 bytes (10,11,12,13) each 500 ms.
3488 => mwc.l 100 12345678 10
3489 This command will write 12345678 to address 100 all 10 ms.
3491 This only takes effect if the memory commands are activated
3492 globally (CONFIG_CMD_MEM).
3494 - CONFIG_SKIP_LOWLEVEL_INIT
3495 [ARM, NDS32, MIPS only] If this variable is defined, then certain
3496 low level initializations (like setting up the memory
3497 controller) are omitted and/or U-Boot does not
3498 relocate itself into RAM.
3500 Normally this variable MUST NOT be defined. The only
3501 exception is when U-Boot is loaded (to RAM) by some
3502 other boot loader or by a debugger which performs
3503 these initializations itself.
3506 Modifies the behaviour of start.S when compiling a loader
3507 that is executed before the actual U-Boot. E.g. when
3508 compiling a NAND SPL.
3510 - CONFIG_USE_ARCH_MEMCPY
3511 CONFIG_USE_ARCH_MEMSET
3512 If these options are used a optimized version of memcpy/memset will
3513 be used if available. These functions may be faster under some
3514 conditions but may increase the binary size.
3516 Freescale QE/FMAN Firmware Support:
3517 -----------------------------------
3519 The Freescale QUICCEngine (QE) and Frame Manager (FMAN) both support the
3520 loading of "firmware", which is encoded in the QE firmware binary format.
3521 This firmware often needs to be loaded during U-Boot booting, so macros
3522 are used to identify the storage device (NOR flash, SPI, etc) and the address
3525 - CONFIG_SYS_QE_FMAN_FW_ADDR
3526 The address in the storage device where the firmware is located. The
3527 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
3530 - CONFIG_SYS_QE_FMAN_FW_LENGTH
3531 The maximum possible size of the firmware. The firmware binary format
3532 has a field that specifies the actual size of the firmware, but it
3533 might not be possible to read any part of the firmware unless some
3534 local storage is allocated to hold the entire firmware first.
3536 - CONFIG_SYS_QE_FMAN_FW_IN_NOR
3537 Specifies that QE/FMAN firmware is located in NOR flash, mapped as
3538 normal addressable memory via the LBC. CONFIG_SYS_FMAN_FW_ADDR is the
3539 virtual address in NOR flash.
3541 - CONFIG_SYS_QE_FMAN_FW_IN_NAND
3542 Specifies that QE/FMAN firmware is located in NAND flash.
3543 CONFIG_SYS_FMAN_FW_ADDR is the offset within NAND flash.
3545 - CONFIG_SYS_QE_FMAN_FW_IN_MMC
3546 Specifies that QE/FMAN firmware is located on the primary SD/MMC
3547 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
3549 - CONFIG_SYS_QE_FMAN_FW_IN_SPIFLASH
3550 Specifies that QE/FMAN firmware is located on the primary SPI
3551 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
3553 - CONFIG_SYS_QE_FMAN_FW_IN_REMOTE
3554 Specifies that QE/FMAN firmware is located in the remote (master)
3555 memory space. CONFIG_SYS_FMAN_FW_ADDR is a virtual address which
3556 can be mapped from slave TLB->slave LAW->slave SRIO outbound window
3557 ->master inbound window->master LAW->the ucode address in master's
3560 Building the Software:
3561 ======================
3563 Building U-Boot has been tested in several native build environments
3564 and in many different cross environments. Of course we cannot support
3565 all possibly existing versions of cross development tools in all
3566 (potentially obsolete) versions. In case of tool chain problems we
3567 recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK)
3568 which is extensively used to build and test U-Boot.
3570 If you are not using a native environment, it is assumed that you
3571 have GNU cross compiling tools available in your path. In this case,
3572 you must set the environment variable CROSS_COMPILE in your shell.
3573 Note that no changes to the Makefile or any other source files are
3574 necessary. For example using the ELDK on a 4xx CPU, please enter:
3576 $ CROSS_COMPILE=ppc_4xx-
3577 $ export CROSS_COMPILE
3579 Note: If you wish to generate Windows versions of the utilities in
3580 the tools directory you can use the MinGW toolchain
3581 (http://www.mingw.org). Set your HOST tools to the MinGW
3582 toolchain and execute 'make tools'. For example:
3584 $ make HOSTCC=i586-mingw32msvc-gcc HOSTSTRIP=i586-mingw32msvc-strip tools
3586 Binaries such as tools/mkimage.exe will be created which can
3587 be executed on computers running Windows.
3589 U-Boot is intended to be simple to build. After installing the
3590 sources you must configure U-Boot for one specific board type. This
3595 where "NAME_config" is the name of one of the existing configu-
3596 rations; see boards.cfg for supported names.
3598 Note: for some board special configuration names may exist; check if
3599 additional information is available from the board vendor; for
3600 instance, the TQM823L systems are available without (standard)
3601 or with LCD support. You can select such additional "features"
3602 when choosing the configuration, i. e.
3605 - will configure for a plain TQM823L, i. e. no LCD support
3607 make TQM823L_LCD_config
3608 - will configure for a TQM823L with U-Boot console on LCD
3613 Finally, type "make all", and you should get some working U-Boot
3614 images ready for download to / installation on your system:
3616 - "u-boot.bin" is a raw binary image
3617 - "u-boot" is an image in ELF binary format
3618 - "u-boot.srec" is in Motorola S-Record format
3620 By default the build is performed locally and the objects are saved
3621 in the source directory. One of the two methods can be used to change
3622 this behavior and build U-Boot to some external directory:
3624 1. Add O= to the make command line invocations:
3626 make O=/tmp/build distclean
3627 make O=/tmp/build NAME_config
3628 make O=/tmp/build all
3630 2. Set environment variable BUILD_DIR to point to the desired location:
3632 export BUILD_DIR=/tmp/build
3637 Note that the command line "O=" setting overrides the BUILD_DIR environment
3641 Please be aware that the Makefiles assume you are using GNU make, so
3642 for instance on NetBSD you might need to use "gmake" instead of
3646 If the system board that you have is not listed, then you will need
3647 to port U-Boot to your hardware platform. To do this, follow these
3650 1. Add a new configuration option for your board to the toplevel
3651 "boards.cfg" file, using the existing entries as examples.
3652 Follow the instructions there to keep the boards in order.
3653 2. Create a new directory to hold your board specific code. Add any
3654 files you need. In your board directory, you will need at least
3655 the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds".
3656 3. Create a new configuration file "include/configs/<board>.h" for
3658 3. If you're porting U-Boot to a new CPU, then also create a new
3659 directory to hold your CPU specific code. Add any files you need.
3660 4. Run "make <board>_config" with your new name.
3661 5. Type "make", and you should get a working "u-boot.srec" file
3662 to be installed on your target system.
3663 6. Debug and solve any problems that might arise.
3664 [Of course, this last step is much harder than it sounds.]
3667 Testing of U-Boot Modifications, Ports to New Hardware, etc.:
3668 ==============================================================
3670 If you have modified U-Boot sources (for instance added a new board
3671 or support for new devices, a new CPU, etc.) you are expected to
3672 provide feedback to the other developers. The feedback normally takes
3673 the form of a "patch", i. e. a context diff against a certain (latest
3674 official or latest in the git repository) version of U-Boot sources.
3676 But before you submit such a patch, please verify that your modifi-
3677 cation did not break existing code. At least make sure that *ALL* of
3678 the supported boards compile WITHOUT ANY compiler warnings. To do so,
3679 just run the "MAKEALL" script, which will configure and build U-Boot
3680 for ALL supported system. Be warned, this will take a while. You can
3681 select which (cross) compiler to use by passing a `CROSS_COMPILE'
3682 environment variable to the script, i. e. to use the ELDK cross tools
3685 CROSS_COMPILE=ppc_8xx- MAKEALL
3687 or to build on a native PowerPC system you can type
3689 CROSS_COMPILE=' ' MAKEALL
3691 When using the MAKEALL script, the default behaviour is to build
3692 U-Boot in the source directory. This location can be changed by
3693 setting the BUILD_DIR environment variable. Also, for each target
3694 built, the MAKEALL script saves two log files (<target>.ERR and
3695 <target>.MAKEALL) in the <source dir>/LOG directory. This default
3696 location can be changed by setting the MAKEALL_LOGDIR environment
3697 variable. For example:
3699 export BUILD_DIR=/tmp/build
3700 export MAKEALL_LOGDIR=/tmp/log
3701 CROSS_COMPILE=ppc_8xx- MAKEALL
3703 With the above settings build objects are saved in the /tmp/build,
3704 log files are saved in the /tmp/log and the source tree remains clean
3705 during the whole build process.
3708 See also "U-Boot Porting Guide" below.
3711 Monitor Commands - Overview:
3712 ============================
3714 go - start application at address 'addr'
3715 run - run commands in an environment variable
3716 bootm - boot application image from memory
3717 bootp - boot image via network using BootP/TFTP protocol
3718 bootz - boot zImage from memory
3719 tftpboot- boot image via network using TFTP protocol
3720 and env variables "ipaddr" and "serverip"
3721 (and eventually "gatewayip")
3722 tftpput - upload a file via network using TFTP protocol
3723 rarpboot- boot image via network using RARP/TFTP protocol
3724 diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
3725 loads - load S-Record file over serial line
3726 loadb - load binary file over serial line (kermit mode)
3728 mm - memory modify (auto-incrementing)
3729 nm - memory modify (constant address)
3730 mw - memory write (fill)
3732 cmp - memory compare
3733 crc32 - checksum calculation
3734 i2c - I2C sub-system
3735 sspi - SPI utility commands
3736 base - print or set address offset
3737 printenv- print environment variables
3738 setenv - set environment variables
3739 saveenv - save environment variables to persistent storage
3740 protect - enable or disable FLASH write protection
3741 erase - erase FLASH memory
3742 flinfo - print FLASH memory information
3743 bdinfo - print Board Info structure
3744 iminfo - print header information for application image
3745 coninfo - print console devices and informations
3746 ide - IDE sub-system
3747 loop - infinite loop on address range
3748 loopw - infinite write loop on address range
3749 mtest - simple RAM test
3750 icache - enable or disable instruction cache
3751 dcache - enable or disable data cache
3752 reset - Perform RESET of the CPU
3753 echo - echo args to console
3754 version - print monitor version
3755 help - print online help
3756 ? - alias for 'help'
3759 Monitor Commands - Detailed Description:
3760 ========================================
3764 For now: just type "help <command>".
3767 Environment Variables:
3768 ======================
3770 U-Boot supports user configuration using Environment Variables which
3771 can be made persistent by saving to Flash memory.
3773 Environment Variables are set using "setenv", printed using
3774 "printenv", and saved to Flash using "saveenv". Using "setenv"
3775 without a value can be used to delete a variable from the
3776 environment. As long as you don't save the environment you are
3777 working with an in-memory copy. In case the Flash area containing the
3778 environment is erased by accident, a default environment is provided.
3780 Some configuration options can be set using Environment Variables.
3782 List of environment variables (most likely not complete):
3784 baudrate - see CONFIG_BAUDRATE
3786 bootdelay - see CONFIG_BOOTDELAY
3788 bootcmd - see CONFIG_BOOTCOMMAND
3790 bootargs - Boot arguments when booting an RTOS image
3792 bootfile - Name of the image to load with TFTP
3794 bootm_low - Memory range available for image processing in the bootm
3795 command can be restricted. This variable is given as
3796 a hexadecimal number and defines lowest address allowed
3797 for use by the bootm command. See also "bootm_size"
3798 environment variable. Address defined by "bootm_low" is
3799 also the base of the initial memory mapping for the Linux
3800 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ and
3803 bootm_mapsize - Size of the initial memory mapping for the Linux kernel.
3804 This variable is given as a hexadecimal number and it
3805 defines the size of the memory region starting at base
3806 address bootm_low that is accessible by the Linux kernel
3807 during early boot. If unset, CONFIG_SYS_BOOTMAPSZ is used
3808 as the default value if it is defined, and bootm_size is
3811 bootm_size - Memory range available for image processing in the bootm
3812 command can be restricted. This variable is given as
3813 a hexadecimal number and defines the size of the region
3814 allowed for use by the bootm command. See also "bootm_low"
3815 environment variable.
3817 updatefile - Location of the software update file on a TFTP server, used
3818 by the automatic software update feature. Please refer to
3819 documentation in doc/README.update for more details.
3821 autoload - if set to "no" (any string beginning with 'n'),
3822 "bootp" will just load perform a lookup of the
3823 configuration from the BOOTP server, but not try to
3824 load any image using TFTP
3826 autostart - if set to "yes", an image loaded using the "bootp",
3827 "rarpboot", "tftpboot" or "diskboot" commands will
3828 be automatically started (by internally calling
3831 If set to "no", a standalone image passed to the
3832 "bootm" command will be copied to the load address
3833 (and eventually uncompressed), but NOT be started.
3834 This can be used to load and uncompress arbitrary
3837 fdt_high - if set this restricts the maximum address that the
3838 flattened device tree will be copied into upon boot.
3839 For example, if you have a system with 1 GB memory
3840 at physical address 0x10000000, while Linux kernel
3841 only recognizes the first 704 MB as low memory, you
3842 may need to set fdt_high as 0x3C000000 to have the
3843 device tree blob be copied to the maximum address
3844 of the 704 MB low memory, so that Linux kernel can
3845 access it during the boot procedure.
3847 If this is set to the special value 0xFFFFFFFF then
3848 the fdt will not be copied at all on boot. For this
3849 to work it must reside in writable memory, have
3850 sufficient padding on the end of it for u-boot to
3851 add the information it needs into it, and the memory
3852 must be accessible by the kernel.
3854 fdtcontroladdr- if set this is the address of the control flattened
3855 device tree used by U-Boot when CONFIG_OF_CONTROL is
3858 i2cfast - (PPC405GP|PPC405EP only)
3859 if set to 'y' configures Linux I2C driver for fast
3860 mode (400kHZ). This environment variable is used in
3861 initialization code. So, for changes to be effective
3862 it must be saved and board must be reset.
3864 initrd_high - restrict positioning of initrd images:
3865 If this variable is not set, initrd images will be
3866 copied to the highest possible address in RAM; this
3867 is usually what you want since it allows for
3868 maximum initrd size. If for some reason you want to
3869 make sure that the initrd image is loaded below the
3870 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment
3871 variable to a value of "no" or "off" or "0".
3872 Alternatively, you can set it to a maximum upper
3873 address to use (U-Boot will still check that it
3874 does not overwrite the U-Boot stack and data).
3876 For instance, when you have a system with 16 MB
3877 RAM, and want to reserve 4 MB from use by Linux,
3878 you can do this by adding "mem=12M" to the value of
3879 the "bootargs" variable. However, now you must make
3880 sure that the initrd image is placed in the first
3881 12 MB as well - this can be done with
3883 setenv initrd_high 00c00000
3885 If you set initrd_high to 0xFFFFFFFF, this is an
3886 indication to U-Boot that all addresses are legal
3887 for the Linux kernel, including addresses in flash
3888 memory. In this case U-Boot will NOT COPY the
3889 ramdisk at all. This may be useful to reduce the
3890 boot time on your system, but requires that this
3891 feature is supported by your Linux kernel.
3893 ipaddr - IP address; needed for tftpboot command
3895 loadaddr - Default load address for commands like "bootp",
3896 "rarpboot", "tftpboot", "loadb" or "diskboot"
3898 loads_echo - see CONFIG_LOADS_ECHO
3900 serverip - TFTP server IP address; needed for tftpboot command
3902 bootretry - see CONFIG_BOOT_RETRY_TIME
3904 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
3906 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
3908 ethprime - controls which interface is used first.
3910 ethact - controls which interface is currently active.
3911 For example you can do the following
3913 => setenv ethact FEC
3914 => ping 192.168.0.1 # traffic sent on FEC
3915 => setenv ethact SCC
3916 => ping 10.0.0.1 # traffic sent on SCC
3918 ethrotate - When set to "no" U-Boot does not go through all
3919 available network interfaces.
3920 It just stays at the currently selected interface.
3922 netretry - When set to "no" each network operation will
3923 either succeed or fail without retrying.
3924 When set to "once" the network operation will
3925 fail when all the available network interfaces
3926 are tried once without success.
3927 Useful on scripts which control the retry operation
3930 npe_ucode - set load address for the NPE microcode
3932 tftpsrcport - If this is set, the value is used for TFTP's
3935 tftpdstport - If this is set, the value is used for TFTP's UDP
3936 destination port instead of the Well Know Port 69.
3938 tftpblocksize - Block size to use for TFTP transfers; if not set,
3939 we use the TFTP server's default block size
3941 tftptimeout - Retransmission timeout for TFTP packets (in milli-
3942 seconds, minimum value is 1000 = 1 second). Defines
3943 when a packet is considered to be lost so it has to
3944 be retransmitted. The default is 5000 = 5 seconds.
3945 Lowering this value may make downloads succeed
3946 faster in networks with high packet loss rates or
3947 with unreliable TFTP servers.
3949 vlan - When set to a value < 4095 the traffic over
3950 Ethernet is encapsulated/received over 802.1q
3953 The following image location variables contain the location of images
3954 used in booting. The "Image" column gives the role of the image and is
3955 not an environment variable name. The other columns are environment
3956 variable names. "File Name" gives the name of the file on a TFTP
3957 server, "RAM Address" gives the location in RAM the image will be
3958 loaded to, and "Flash Location" gives the image's address in NOR
3959 flash or offset in NAND flash.
3961 *Note* - these variables don't have to be defined for all boards, some
3962 boards currenlty use other variables for these purposes, and some
3963 boards use these variables for other purposes.
3965 Image File Name RAM Address Flash Location
3966 ----- --------- ----------- --------------
3967 u-boot u-boot u-boot_addr_r u-boot_addr
3968 Linux kernel bootfile kernel_addr_r kernel_addr
3969 device tree blob fdtfile fdt_addr_r fdt_addr
3970 ramdisk ramdiskfile ramdisk_addr_r ramdisk_addr
3972 The following environment variables may be used and automatically
3973 updated by the network boot commands ("bootp" and "rarpboot"),
3974 depending the information provided by your boot server:
3976 bootfile - see above
3977 dnsip - IP address of your Domain Name Server
3978 dnsip2 - IP address of your secondary Domain Name Server
3979 gatewayip - IP address of the Gateway (Router) to use
3980 hostname - Target hostname
3982 netmask - Subnet Mask
3983 rootpath - Pathname of the root filesystem on the NFS server
3984 serverip - see above
3987 There are two special Environment Variables:
3989 serial# - contains hardware identification information such
3990 as type string and/or serial number
3991 ethaddr - Ethernet address
3993 These variables can be set only once (usually during manufacturing of
3994 the board). U-Boot refuses to delete or overwrite these variables
3995 once they have been set once.
3998 Further special Environment Variables:
4000 ver - Contains the U-Boot version string as printed
4001 with the "version" command. This variable is
4002 readonly (see CONFIG_VERSION_VARIABLE).
4005 Please note that changes to some configuration parameters may take
4006 only effect after the next boot (yes, that's just like Windoze :-).
4009 Command Line Parsing:
4010 =====================
4012 There are two different command line parsers available with U-Boot:
4013 the old "simple" one, and the much more powerful "hush" shell:
4015 Old, simple command line parser:
4016 --------------------------------
4018 - supports environment variables (through setenv / saveenv commands)
4019 - several commands on one line, separated by ';'
4020 - variable substitution using "... ${name} ..." syntax
4021 - special characters ('$', ';') can be escaped by prefixing with '\',
4023 setenv bootcmd bootm \${address}
4024 - You can also escape text by enclosing in single apostrophes, for example:
4025 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
4030 - similar to Bourne shell, with control structures like
4031 if...then...else...fi, for...do...done; while...do...done,
4032 until...do...done, ...
4033 - supports environment ("global") variables (through setenv / saveenv
4034 commands) and local shell variables (through standard shell syntax
4035 "name=value"); only environment variables can be used with "run"
4041 (1) If a command line (or an environment variable executed by a "run"
4042 command) contains several commands separated by semicolon, and
4043 one of these commands fails, then the remaining commands will be
4046 (2) If you execute several variables with one call to run (i. e.
4047 calling run with a list of variables as arguments), any failing
4048 command will cause "run" to terminate, i. e. the remaining
4049 variables are not executed.
4051 Note for Redundant Ethernet Interfaces:
4052 =======================================
4054 Some boards come with redundant Ethernet interfaces; U-Boot supports
4055 such configurations and is capable of automatic selection of a
4056 "working" interface when needed. MAC assignment works as follows:
4058 Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
4059 MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
4060 "eth1addr" (=>eth1), "eth2addr", ...
4062 If the network interface stores some valid MAC address (for instance
4063 in SROM), this is used as default address if there is NO correspon-
4064 ding setting in the environment; if the corresponding environment
4065 variable is set, this overrides the settings in the card; that means:
4067 o If the SROM has a valid MAC address, and there is no address in the
4068 environment, the SROM's address is used.
4070 o If there is no valid address in the SROM, and a definition in the
4071 environment exists, then the value from the environment variable is
4074 o If both the SROM and the environment contain a MAC address, and
4075 both addresses are the same, this MAC address is used.
4077 o If both the SROM and the environment contain a MAC address, and the
4078 addresses differ, the value from the environment is used and a
4081 o If neither SROM nor the environment contain a MAC address, an error
4084 If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses
4085 will be programmed into hardware as part of the initialization process. This
4086 may be skipped by setting the appropriate 'ethmacskip' environment variable.
4087 The naming convention is as follows:
4088 "ethmacskip" (=>eth0), "eth1macskip" (=>eth1) etc.
4093 U-Boot is capable of booting (and performing other auxiliary operations on)
4094 images in two formats:
4096 New uImage format (FIT)
4097 -----------------------
4099 Flexible and powerful format based on Flattened Image Tree -- FIT (similar
4100 to Flattened Device Tree). It allows the use of images with multiple
4101 components (several kernels, ramdisks, etc.), with contents protected by
4102 SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory.
4108 Old image format is based on binary files which can be basically anything,
4109 preceded by a special header; see the definitions in include/image.h for
4110 details; basically, the header defines the following image properties:
4112 * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
4113 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
4114 LynxOS, pSOS, QNX, RTEMS, INTEGRITY;
4115 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS,
4117 * Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86,
4118 IA64, MIPS, NDS32, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
4119 Currently supported: ARM, AVR32, Intel x86, MIPS, NDS32, Nios II, PowerPC).
4120 * Compression Type (uncompressed, gzip, bzip2)
4126 The header is marked by a special Magic Number, and both the header
4127 and the data portions of the image are secured against corruption by
4134 Although U-Boot should support any OS or standalone application
4135 easily, the main focus has always been on Linux during the design of
4138 U-Boot includes many features that so far have been part of some
4139 special "boot loader" code within the Linux kernel. Also, any
4140 "initrd" images to be used are no longer part of one big Linux image;
4141 instead, kernel and "initrd" are separate images. This implementation
4142 serves several purposes:
4144 - the same features can be used for other OS or standalone
4145 applications (for instance: using compressed images to reduce the
4146 Flash memory footprint)
4148 - it becomes much easier to port new Linux kernel versions because
4149 lots of low-level, hardware dependent stuff are done by U-Boot
4151 - the same Linux kernel image can now be used with different "initrd"
4152 images; of course this also means that different kernel images can
4153 be run with the same "initrd". This makes testing easier (you don't
4154 have to build a new "zImage.initrd" Linux image when you just
4155 change a file in your "initrd"). Also, a field-upgrade of the
4156 software is easier now.
4162 Porting Linux to U-Boot based systems:
4163 ---------------------------------------
4165 U-Boot cannot save you from doing all the necessary modifications to
4166 configure the Linux device drivers for use with your target hardware
4167 (no, we don't intend to provide a full virtual machine interface to
4170 But now you can ignore ALL boot loader code (in arch/powerpc/mbxboot).
4172 Just make sure your machine specific header file (for instance
4173 include/asm-ppc/tqm8xx.h) includes the same definition of the Board
4174 Information structure as we define in include/asm-<arch>/u-boot.h,
4175 and make sure that your definition of IMAP_ADDR uses the same value
4176 as your U-Boot configuration in CONFIG_SYS_IMMR.
4179 Configuring the Linux kernel:
4180 -----------------------------
4182 No specific requirements for U-Boot. Make sure you have some root
4183 device (initial ramdisk, NFS) for your target system.
4186 Building a Linux Image:
4187 -----------------------
4189 With U-Boot, "normal" build targets like "zImage" or "bzImage" are
4190 not used. If you use recent kernel source, a new build target
4191 "uImage" will exist which automatically builds an image usable by
4192 U-Boot. Most older kernels also have support for a "pImage" target,
4193 which was introduced for our predecessor project PPCBoot and uses a
4194 100% compatible format.
4203 The "uImage" build target uses a special tool (in 'tools/mkimage') to
4204 encapsulate a compressed Linux kernel image with header information,
4205 CRC32 checksum etc. for use with U-Boot. This is what we are doing:
4207 * build a standard "vmlinux" kernel image (in ELF binary format):
4209 * convert the kernel into a raw binary image:
4211 ${CROSS_COMPILE}-objcopy -O binary \
4212 -R .note -R .comment \
4213 -S vmlinux linux.bin
4215 * compress the binary image:
4219 * package compressed binary image for U-Boot:
4221 mkimage -A ppc -O linux -T kernel -C gzip \
4222 -a 0 -e 0 -n "Linux Kernel Image" \
4223 -d linux.bin.gz uImage
4226 The "mkimage" tool can also be used to create ramdisk images for use
4227 with U-Boot, either separated from the Linux kernel image, or
4228 combined into one file. "mkimage" encapsulates the images with a 64
4229 byte header containing information about target architecture,
4230 operating system, image type, compression method, entry points, time
4231 stamp, CRC32 checksums, etc.
4233 "mkimage" can be called in two ways: to verify existing images and
4234 print the header information, or to build new images.
4236 In the first form (with "-l" option) mkimage lists the information
4237 contained in the header of an existing U-Boot image; this includes
4238 checksum verification:
4240 tools/mkimage -l image
4241 -l ==> list image header information
4243 The second form (with "-d" option) is used to build a U-Boot image
4244 from a "data file" which is used as image payload:
4246 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
4247 -n name -d data_file image
4248 -A ==> set architecture to 'arch'
4249 -O ==> set operating system to 'os'
4250 -T ==> set image type to 'type'
4251 -C ==> set compression type 'comp'
4252 -a ==> set load address to 'addr' (hex)
4253 -e ==> set entry point to 'ep' (hex)
4254 -n ==> set image name to 'name'
4255 -d ==> use image data from 'datafile'
4257 Right now, all Linux kernels for PowerPC systems use the same load
4258 address (0x00000000), but the entry point address depends on the
4261 - 2.2.x kernels have the entry point at 0x0000000C,
4262 - 2.3.x and later kernels have the entry point at 0x00000000.
4264 So a typical call to build a U-Boot image would read:
4266 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
4267 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
4268 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz \
4269 > examples/uImage.TQM850L
4270 Image Name: 2.4.4 kernel for TQM850L
4271 Created: Wed Jul 19 02:34:59 2000
4272 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4273 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
4274 Load Address: 0x00000000
4275 Entry Point: 0x00000000
4277 To verify the contents of the image (or check for corruption):
4279 -> tools/mkimage -l examples/uImage.TQM850L
4280 Image Name: 2.4.4 kernel for TQM850L
4281 Created: Wed Jul 19 02:34:59 2000
4282 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4283 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
4284 Load Address: 0x00000000
4285 Entry Point: 0x00000000
4287 NOTE: for embedded systems where boot time is critical you can trade
4288 speed for memory and install an UNCOMPRESSED image instead: this
4289 needs more space in Flash, but boots much faster since it does not
4290 need to be uncompressed:
4292 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz
4293 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
4294 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
4295 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux \
4296 > examples/uImage.TQM850L-uncompressed
4297 Image Name: 2.4.4 kernel for TQM850L
4298 Created: Wed Jul 19 02:34:59 2000
4299 Image Type: PowerPC Linux Kernel Image (uncompressed)
4300 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
4301 Load Address: 0x00000000
4302 Entry Point: 0x00000000
4305 Similar you can build U-Boot images from a 'ramdisk.image.gz' file
4306 when your kernel is intended to use an initial ramdisk:
4308 -> tools/mkimage -n 'Simple Ramdisk Image' \
4309 > -A ppc -O linux -T ramdisk -C gzip \
4310 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
4311 Image Name: Simple Ramdisk Image
4312 Created: Wed Jan 12 14:01:50 2000
4313 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
4314 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
4315 Load Address: 0x00000000
4316 Entry Point: 0x00000000
4319 Installing a Linux Image:
4320 -------------------------
4322 To downloading a U-Boot image over the serial (console) interface,
4323 you must convert the image to S-Record format:
4325 objcopy -I binary -O srec examples/image examples/image.srec
4327 The 'objcopy' does not understand the information in the U-Boot
4328 image header, so the resulting S-Record file will be relative to
4329 address 0x00000000. To load it to a given address, you need to
4330 specify the target address as 'offset' parameter with the 'loads'
4333 Example: install the image to address 0x40100000 (which on the
4334 TQM8xxL is in the first Flash bank):
4336 => erase 40100000 401FFFFF
4342 ## Ready for S-Record download ...
4343 ~>examples/image.srec
4344 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
4346 15989 15990 15991 15992
4347 [file transfer complete]
4349 ## Start Addr = 0x00000000
4352 You can check the success of the download using the 'iminfo' command;
4353 this includes a checksum verification so you can be sure no data
4354 corruption happened:
4358 ## Checking Image at 40100000 ...
4359 Image Name: 2.2.13 for initrd on TQM850L
4360 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4361 Data Size: 335725 Bytes = 327 kB = 0 MB
4362 Load Address: 00000000
4363 Entry Point: 0000000c
4364 Verifying Checksum ... OK
4370 The "bootm" command is used to boot an application that is stored in
4371 memory (RAM or Flash). In case of a Linux kernel image, the contents
4372 of the "bootargs" environment variable is passed to the kernel as
4373 parameters. You can check and modify this variable using the
4374 "printenv" and "setenv" commands:
4377 => printenv bootargs
4378 bootargs=root=/dev/ram
4380 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
4382 => printenv bootargs
4383 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
4386 ## Booting Linux kernel at 40020000 ...
4387 Image Name: 2.2.13 for NFS on TQM850L
4388 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4389 Data Size: 381681 Bytes = 372 kB = 0 MB
4390 Load Address: 00000000
4391 Entry Point: 0000000c
4392 Verifying Checksum ... OK
4393 Uncompressing Kernel Image ... OK
4394 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
4395 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
4396 time_init: decrementer frequency = 187500000/60
4397 Calibrating delay loop... 49.77 BogoMIPS
4398 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
4401 If you want to boot a Linux kernel with initial RAM disk, you pass
4402 the memory addresses of both the kernel and the initrd image (PPBCOOT
4403 format!) to the "bootm" command:
4405 => imi 40100000 40200000
4407 ## Checking Image at 40100000 ...
4408 Image Name: 2.2.13 for initrd on TQM850L
4409 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4410 Data Size: 335725 Bytes = 327 kB = 0 MB
4411 Load Address: 00000000
4412 Entry Point: 0000000c
4413 Verifying Checksum ... OK
4415 ## Checking Image at 40200000 ...
4416 Image Name: Simple Ramdisk Image
4417 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
4418 Data Size: 566530 Bytes = 553 kB = 0 MB
4419 Load Address: 00000000
4420 Entry Point: 00000000
4421 Verifying Checksum ... OK
4423 => bootm 40100000 40200000
4424 ## Booting Linux kernel at 40100000 ...
4425 Image Name: 2.2.13 for initrd on TQM850L
4426 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4427 Data Size: 335725 Bytes = 327 kB = 0 MB
4428 Load Address: 00000000
4429 Entry Point: 0000000c
4430 Verifying Checksum ... OK
4431 Uncompressing Kernel Image ... OK
4432 ## Loading RAMDisk Image at 40200000 ...
4433 Image Name: Simple Ramdisk Image
4434 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
4435 Data Size: 566530 Bytes = 553 kB = 0 MB
4436 Load Address: 00000000
4437 Entry Point: 00000000
4438 Verifying Checksum ... OK
4439 Loading Ramdisk ... OK
4440 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
4441 Boot arguments: root=/dev/ram
4442 time_init: decrementer frequency = 187500000/60
4443 Calibrating delay loop... 49.77 BogoMIPS
4445 RAMDISK: Compressed image found at block 0
4446 VFS: Mounted root (ext2 filesystem).
4450 Boot Linux and pass a flat device tree:
4453 First, U-Boot must be compiled with the appropriate defines. See the section
4454 titled "Linux Kernel Interface" above for a more in depth explanation. The
4455 following is an example of how to start a kernel and pass an updated
4461 oft=oftrees/mpc8540ads.dtb
4462 => tftp $oftaddr $oft
4463 Speed: 1000, full duplex
4465 TFTP from server 192.168.1.1; our IP address is 192.168.1.101
4466 Filename 'oftrees/mpc8540ads.dtb'.
4467 Load address: 0x300000
4470 Bytes transferred = 4106 (100a hex)
4471 => tftp $loadaddr $bootfile
4472 Speed: 1000, full duplex
4474 TFTP from server 192.168.1.1; our IP address is 192.168.1.2
4476 Load address: 0x200000
4477 Loading:############
4479 Bytes transferred = 1029407 (fb51f hex)
4484 => bootm $loadaddr - $oftaddr
4485 ## Booting image at 00200000 ...
4486 Image Name: Linux-2.6.17-dirty
4487 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4488 Data Size: 1029343 Bytes = 1005.2 kB
4489 Load Address: 00000000
4490 Entry Point: 00000000
4491 Verifying Checksum ... OK
4492 Uncompressing Kernel Image ... OK
4493 Booting using flat device tree at 0x300000
4494 Using MPC85xx ADS machine description
4495 Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb
4499 More About U-Boot Image Types:
4500 ------------------------------
4502 U-Boot supports the following image types:
4504 "Standalone Programs" are directly runnable in the environment
4505 provided by U-Boot; it is expected that (if they behave
4506 well) you can continue to work in U-Boot after return from
4507 the Standalone Program.
4508 "OS Kernel Images" are usually images of some Embedded OS which
4509 will take over control completely. Usually these programs
4510 will install their own set of exception handlers, device
4511 drivers, set up the MMU, etc. - this means, that you cannot
4512 expect to re-enter U-Boot except by resetting the CPU.
4513 "RAMDisk Images" are more or less just data blocks, and their
4514 parameters (address, size) are passed to an OS kernel that is
4516 "Multi-File Images" contain several images, typically an OS
4517 (Linux) kernel image and one or more data images like
4518 RAMDisks. This construct is useful for instance when you want
4519 to boot over the network using BOOTP etc., where the boot
4520 server provides just a single image file, but you want to get
4521 for instance an OS kernel and a RAMDisk image.
4523 "Multi-File Images" start with a list of image sizes, each
4524 image size (in bytes) specified by an "uint32_t" in network
4525 byte order. This list is terminated by an "(uint32_t)0".
4526 Immediately after the terminating 0 follow the images, one by
4527 one, all aligned on "uint32_t" boundaries (size rounded up to
4528 a multiple of 4 bytes).
4530 "Firmware Images" are binary images containing firmware (like
4531 U-Boot or FPGA images) which usually will be programmed to
4534 "Script files" are command sequences that will be executed by
4535 U-Boot's command interpreter; this feature is especially
4536 useful when you configure U-Boot to use a real shell (hush)
4537 as command interpreter.
4539 Booting the Linux zImage:
4540 -------------------------
4542 On some platforms, it's possible to boot Linux zImage. This is done
4543 using the "bootz" command. The syntax of "bootz" command is the same
4544 as the syntax of "bootm" command.
4546 Note, defining the CONFIG_SUPPORT_INITRD_RAW allows user to supply
4547 kernel with raw initrd images. The syntax is slightly different, the
4548 address of the initrd must be augmented by it's size, in the following
4549 format: "<initrd addres>:<initrd size>".
4555 One of the features of U-Boot is that you can dynamically load and
4556 run "standalone" applications, which can use some resources of
4557 U-Boot like console I/O functions or interrupt services.
4559 Two simple examples are included with the sources:
4564 'examples/hello_world.c' contains a small "Hello World" Demo
4565 application; it is automatically compiled when you build U-Boot.
4566 It's configured to run at address 0x00040004, so you can play with it
4570 ## Ready for S-Record download ...
4571 ~>examples/hello_world.srec
4572 1 2 3 4 5 6 7 8 9 10 11 ...
4573 [file transfer complete]
4575 ## Start Addr = 0x00040004
4577 => go 40004 Hello World! This is a test.
4578 ## Starting application at 0x00040004 ...
4589 Hit any key to exit ...
4591 ## Application terminated, rc = 0x0
4593 Another example, which demonstrates how to register a CPM interrupt
4594 handler with the U-Boot code, can be found in 'examples/timer.c'.
4595 Here, a CPM timer is set up to generate an interrupt every second.
4596 The interrupt service routine is trivial, just printing a '.'
4597 character, but this is just a demo program. The application can be
4598 controlled by the following keys:
4600 ? - print current values og the CPM Timer registers
4601 b - enable interrupts and start timer
4602 e - stop timer and disable interrupts
4603 q - quit application
4606 ## Ready for S-Record download ...
4607 ~>examples/timer.srec
4608 1 2 3 4 5 6 7 8 9 10 11 ...
4609 [file transfer complete]
4611 ## Start Addr = 0x00040004
4614 ## Starting application at 0x00040004 ...
4617 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
4620 [q, b, e, ?] Set interval 1000000 us
4623 [q, b, e, ?] ........
4624 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
4627 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
4630 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
4633 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
4635 [q, b, e, ?] ...Stopping timer
4637 [q, b, e, ?] ## Application terminated, rc = 0x0
4643 Over time, many people have reported problems when trying to use the
4644 "minicom" terminal emulation program for serial download. I (wd)
4645 consider minicom to be broken, and recommend not to use it. Under
4646 Unix, I recommend to use C-Kermit for general purpose use (and
4647 especially for kermit binary protocol download ("loadb" command), and
4648 use "cu" for S-Record download ("loads" command).
4650 Nevertheless, if you absolutely want to use it try adding this
4651 configuration to your "File transfer protocols" section:
4653 Name Program Name U/D FullScr IO-Red. Multi
4654 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
4655 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
4661 Starting at version 0.9.2, U-Boot supports NetBSD both as host
4662 (build U-Boot) and target system (boots NetBSD/mpc8xx).
4664 Building requires a cross environment; it is known to work on
4665 NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
4666 need gmake since the Makefiles are not compatible with BSD make).
4667 Note that the cross-powerpc package does not install include files;
4668 attempting to build U-Boot will fail because <machine/ansi.h> is
4669 missing. This file has to be installed and patched manually:
4671 # cd /usr/pkg/cross/powerpc-netbsd/include
4673 # ln -s powerpc machine
4674 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
4675 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
4677 Native builds *don't* work due to incompatibilities between native
4678 and U-Boot include files.
4680 Booting assumes that (the first part of) the image booted is a
4681 stage-2 loader which in turn loads and then invokes the kernel
4682 proper. Loader sources will eventually appear in the NetBSD source
4683 tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
4684 meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz
4687 Implementation Internals:
4688 =========================
4690 The following is not intended to be a complete description of every
4691 implementation detail. However, it should help to understand the
4692 inner workings of U-Boot and make it easier to port it to custom
4696 Initial Stack, Global Data:
4697 ---------------------------
4699 The implementation of U-Boot is complicated by the fact that U-Boot
4700 starts running out of ROM (flash memory), usually without access to
4701 system RAM (because the memory controller is not initialized yet).
4702 This means that we don't have writable Data or BSS segments, and BSS
4703 is not initialized as zero. To be able to get a C environment working
4704 at all, we have to allocate at least a minimal stack. Implementation
4705 options for this are defined and restricted by the CPU used: Some CPU
4706 models provide on-chip memory (like the IMMR area on MPC8xx and
4707 MPC826x processors), on others (parts of) the data cache can be
4708 locked as (mis-) used as memory, etc.
4710 Chris Hallinan posted a good summary of these issues to the
4711 U-Boot mailing list:
4713 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
4714 From: "Chris Hallinan" <clh@net1plus.com>
4715 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
4718 Correct me if I'm wrong, folks, but the way I understand it
4719 is this: Using DCACHE as initial RAM for Stack, etc, does not
4720 require any physical RAM backing up the cache. The cleverness
4721 is that the cache is being used as a temporary supply of
4722 necessary storage before the SDRAM controller is setup. It's
4723 beyond the scope of this list to explain the details, but you
4724 can see how this works by studying the cache architecture and
4725 operation in the architecture and processor-specific manuals.
4727 OCM is On Chip Memory, which I believe the 405GP has 4K. It
4728 is another option for the system designer to use as an
4729 initial stack/RAM area prior to SDRAM being available. Either
4730 option should work for you. Using CS 4 should be fine if your
4731 board designers haven't used it for something that would
4732 cause you grief during the initial boot! It is frequently not
4735 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere
4736 with your processor/board/system design. The default value
4737 you will find in any recent u-boot distribution in
4738 walnut.h should work for you. I'd set it to a value larger
4739 than your SDRAM module. If you have a 64MB SDRAM module, set
4740 it above 400_0000. Just make sure your board has no resources
4741 that are supposed to respond to that address! That code in
4742 start.S has been around a while and should work as is when
4743 you get the config right.
4748 It is essential to remember this, since it has some impact on the C
4749 code for the initialization procedures:
4751 * Initialized global data (data segment) is read-only. Do not attempt
4754 * Do not use any uninitialized global data (or implicitely initialized
4755 as zero data - BSS segment) at all - this is undefined, initiali-
4756 zation is performed later (when relocating to RAM).
4758 * Stack space is very limited. Avoid big data buffers or things like
4761 Having only the stack as writable memory limits means we cannot use
4762 normal global data to share information beween the code. But it
4763 turned out that the implementation of U-Boot can be greatly
4764 simplified by making a global data structure (gd_t) available to all
4765 functions. We could pass a pointer to this data as argument to _all_
4766 functions, but this would bloat the code. Instead we use a feature of
4767 the GCC compiler (Global Register Variables) to share the data: we
4768 place a pointer (gd) to the global data into a register which we
4769 reserve for this purpose.
4771 When choosing a register for such a purpose we are restricted by the
4772 relevant (E)ABI specifications for the current architecture, and by
4773 GCC's implementation.
4775 For PowerPC, the following registers have specific use:
4777 R2: reserved for system use
4778 R3-R4: parameter passing and return values
4779 R5-R10: parameter passing
4780 R13: small data area pointer
4784 (U-Boot also uses R12 as internal GOT pointer. r12
4785 is a volatile register so r12 needs to be reset when
4786 going back and forth between asm and C)
4788 ==> U-Boot will use R2 to hold a pointer to the global data
4790 Note: on PPC, we could use a static initializer (since the
4791 address of the global data structure is known at compile time),
4792 but it turned out that reserving a register results in somewhat
4793 smaller code - although the code savings are not that big (on
4794 average for all boards 752 bytes for the whole U-Boot image,
4795 624 text + 127 data).
4797 On Blackfin, the normal C ABI (except for P3) is followed as documented here:
4798 http://docs.blackfin.uclinux.org/doku.php?id=application_binary_interface
4800 ==> U-Boot will use P3 to hold a pointer to the global data
4802 On ARM, the following registers are used:
4804 R0: function argument word/integer result
4805 R1-R3: function argument word
4807 R10: stack limit (used only if stack checking if enabled)
4808 R11: argument (frame) pointer
4809 R12: temporary workspace
4812 R15: program counter
4814 ==> U-Boot will use R8 to hold a pointer to the global data
4816 On Nios II, the ABI is documented here:
4817 http://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf
4819 ==> U-Boot will use gp to hold a pointer to the global data
4821 Note: on Nios II, we give "-G0" option to gcc and don't use gp
4822 to access small data sections, so gp is free.
4824 On NDS32, the following registers are used:
4826 R0-R1: argument/return
4828 R15: temporary register for assembler
4829 R16: trampoline register
4830 R28: frame pointer (FP)
4831 R29: global pointer (GP)
4832 R30: link register (LP)
4833 R31: stack pointer (SP)
4834 PC: program counter (PC)
4836 ==> U-Boot will use R10 to hold a pointer to the global data
4838 NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope,
4839 or current versions of GCC may "optimize" the code too much.
4844 U-Boot runs in system state and uses physical addresses, i.e. the
4845 MMU is not used either for address mapping nor for memory protection.
4847 The available memory is mapped to fixed addresses using the memory
4848 controller. In this process, a contiguous block is formed for each
4849 memory type (Flash, SDRAM, SRAM), even when it consists of several
4850 physical memory banks.
4852 U-Boot is installed in the first 128 kB of the first Flash bank (on
4853 TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
4854 booting and sizing and initializing DRAM, the code relocates itself
4855 to the upper end of DRAM. Immediately below the U-Boot code some
4856 memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN
4857 configuration setting]. Below that, a structure with global Board
4858 Info data is placed, followed by the stack (growing downward).
4860 Additionally, some exception handler code is copied to the low 8 kB
4861 of DRAM (0x00000000 ... 0x00001FFF).
4863 So a typical memory configuration with 16 MB of DRAM could look like
4866 0x0000 0000 Exception Vector code
4869 0x0000 2000 Free for Application Use
4875 0x00FB FF20 Monitor Stack (Growing downward)
4876 0x00FB FFAC Board Info Data and permanent copy of global data
4877 0x00FC 0000 Malloc Arena
4880 0x00FE 0000 RAM Copy of Monitor Code
4881 ... eventually: LCD or video framebuffer
4882 ... eventually: pRAM (Protected RAM - unchanged by reset)
4883 0x00FF FFFF [End of RAM]
4886 System Initialization:
4887 ----------------------
4889 In the reset configuration, U-Boot starts at the reset entry point
4890 (on most PowerPC systems at address 0x00000100). Because of the reset
4891 configuration for CS0# this is a mirror of the onboard Flash memory.
4892 To be able to re-map memory U-Boot then jumps to its link address.
4893 To be able to implement the initialization code in C, a (small!)
4894 initial stack is set up in the internal Dual Ported RAM (in case CPUs
4895 which provide such a feature like MPC8xx or MPC8260), or in a locked
4896 part of the data cache. After that, U-Boot initializes the CPU core,
4897 the caches and the SIU.
4899 Next, all (potentially) available memory banks are mapped using a
4900 preliminary mapping. For example, we put them on 512 MB boundaries
4901 (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
4902 on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
4903 programmed for SDRAM access. Using the temporary configuration, a
4904 simple memory test is run that determines the size of the SDRAM
4907 When there is more than one SDRAM bank, and the banks are of
4908 different size, the largest is mapped first. For equal size, the first
4909 bank (CS2#) is mapped first. The first mapping is always for address
4910 0x00000000, with any additional banks following immediately to create
4911 contiguous memory starting from 0.
4913 Then, the monitor installs itself at the upper end of the SDRAM area
4914 and allocates memory for use by malloc() and for the global Board
4915 Info data; also, the exception vector code is copied to the low RAM
4916 pages, and the final stack is set up.
4918 Only after this relocation will you have a "normal" C environment;
4919 until that you are restricted in several ways, mostly because you are
4920 running from ROM, and because the code will have to be relocated to a
4924 U-Boot Porting Guide:
4925 ----------------------
4927 [Based on messages by Jerry Van Baren in the U-Boot-Users mailing
4931 int main(int argc, char *argv[])
4933 sighandler_t no_more_time;
4935 signal(SIGALRM, no_more_time);
4936 alarm(PROJECT_DEADLINE - toSec (3 * WEEK));
4938 if (available_money > available_manpower) {
4939 Pay consultant to port U-Boot;
4943 Download latest U-Boot source;
4945 Subscribe to u-boot mailing list;
4948 email("Hi, I am new to U-Boot, how do I get started?");
4951 Read the README file in the top level directory;
4952 Read http://www.denx.de/twiki/bin/view/DULG/Manual;
4953 Read applicable doc/*.README;
4954 Read the source, Luke;
4955 /* find . -name "*.[chS]" | xargs grep -i <keyword> */
4958 if (available_money > toLocalCurrency ($2500))
4961 Add a lot of aggravation and time;
4963 if (a similar board exists) { /* hopefully... */
4964 cp -a board/<similar> board/<myboard>
4965 cp include/configs/<similar>.h include/configs/<myboard>.h
4967 Create your own board support subdirectory;
4968 Create your own board include/configs/<myboard>.h file;
4970 Edit new board/<myboard> files
4971 Edit new include/configs/<myboard>.h
4976 Add / modify source code;
4980 email("Hi, I am having problems...");
4982 Send patch file to the U-Boot email list;
4983 if (reasonable critiques)
4984 Incorporate improvements from email list code review;
4986 Defend code as written;
4992 void no_more_time (int sig)
5001 All contributions to U-Boot should conform to the Linux kernel
5002 coding style; see the file "Documentation/CodingStyle" and the script
5003 "scripts/Lindent" in your Linux kernel source directory.
5005 Source files originating from a different project (for example the
5006 MTD subsystem) are generally exempt from these guidelines and are not
5007 reformated to ease subsequent migration to newer versions of those
5010 Please note that U-Boot is implemented in C (and to some small parts in
5011 Assembler); no C++ is used, so please do not use C++ style comments (//)
5014 Please also stick to the following formatting rules:
5015 - remove any trailing white space
5016 - use TAB characters for indentation and vertical alignment, not spaces
5017 - make sure NOT to use DOS '\r\n' line feeds
5018 - do not add more than 2 consecutive empty lines to source files
5019 - do not add trailing empty lines to source files
5021 Submissions which do not conform to the standards may be returned
5022 with a request to reformat the changes.
5028 Since the number of patches for U-Boot is growing, we need to
5029 establish some rules. Submissions which do not conform to these rules
5030 may be rejected, even when they contain important and valuable stuff.
5032 Please see http://www.denx.de/wiki/U-Boot/Patches for details.
5034 Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>;
5035 see http://lists.denx.de/mailman/listinfo/u-boot
5037 When you send a patch, please include the following information with
5040 * For bug fixes: a description of the bug and how your patch fixes
5041 this bug. Please try to include a way of demonstrating that the
5042 patch actually fixes something.
5044 * For new features: a description of the feature and your
5047 * A CHANGELOG entry as plaintext (separate from the patch)
5049 * For major contributions, your entry to the CREDITS file
5051 * When you add support for a new board, don't forget to add this
5052 board to the MAINTAINERS file, too.
5054 * If your patch adds new configuration options, don't forget to
5055 document these in the README file.
5057 * The patch itself. If you are using git (which is *strongly*
5058 recommended) you can easily generate the patch using the
5059 "git format-patch". If you then use "git send-email" to send it to
5060 the U-Boot mailing list, you will avoid most of the common problems
5061 with some other mail clients.
5063 If you cannot use git, use "diff -purN OLD NEW". If your version of
5064 diff does not support these options, then get the latest version of
5067 The current directory when running this command shall be the parent
5068 directory of the U-Boot source tree (i. e. please make sure that
5069 your patch includes sufficient directory information for the
5072 We prefer patches as plain text. MIME attachments are discouraged,
5073 and compressed attachments must not be used.
5075 * If one logical set of modifications affects or creates several
5076 files, all these changes shall be submitted in a SINGLE patch file.
5078 * Changesets that contain different, unrelated modifications shall be
5079 submitted as SEPARATE patches, one patch per changeset.
5084 * Before sending the patch, run the MAKEALL script on your patched
5085 source tree and make sure that no errors or warnings are reported
5086 for any of the boards.
5088 * Keep your modifications to the necessary minimum: A patch
5089 containing several unrelated changes or arbitrary reformats will be
5090 returned with a request to re-formatting / split it.
5092 * If you modify existing code, make sure that your new code does not
5093 add to the memory footprint of the code ;-) Small is beautiful!
5094 When adding new features, these should compile conditionally only
5095 (using #ifdef), and the resulting code with the new feature
5096 disabled must not need more memory than the old code without your
5099 * Remember that there is a size limit of 100 kB per message on the
5100 u-boot mailing list. Bigger patches will be moderated. If they are
5101 reasonable and not too big, they will be acknowledged. But patches
5102 bigger than the size limit should be avoided.
projects / platform / kernel / u-boot.git / blob