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
57 Note: There is no CHANGELOG file in the actual U-Boot source tree;
58 it can be created dynamically from the Git log using:
66 In case you have questions about, problems with or contributions for
67 U-Boot you should send a message to the U-Boot mailing list at
68 <u-boot@lists.denx.de>. There is also an archive of previous traffic
69 on the mailing list - please search the archive before asking FAQ's.
70 Please see http://lists.denx.de/pipermail/u-boot and
71 http://dir.gmane.org/gmane.comp.boot-loaders.u-boot
74 Where to get source code:
75 =========================
77 The U-Boot source code is maintained in the git repository at
78 git://www.denx.de/git/u-boot.git ; you can browse it online at
79 http://www.denx.de/cgi-bin/gitweb.cgi?p=u-boot.git;a=summary
81 The "snapshot" links on this page allow you to download tarballs of
82 any version you might be interested in. Official releases are also
83 available for FTP download from the ftp://ftp.denx.de/pub/u-boot/
86 Pre-built (and tested) images are available from
87 ftp://ftp.denx.de/pub/u-boot/images/
93 - start from 8xxrom sources
94 - create PPCBoot project (http://sourceforge.net/projects/ppcboot)
96 - make it easier to add custom boards
97 - make it possible to add other [PowerPC] CPUs
98 - extend functions, especially:
99 * Provide extended interface to Linux boot loader
102 * PCMCIA / CompactFlash / ATA disk / SCSI ... boot
103 - create ARMBoot project (http://sourceforge.net/projects/armboot)
104 - add other CPU families (starting with ARM)
105 - create U-Boot project (http://sourceforge.net/projects/u-boot)
106 - current project page: see http://www.denx.de/wiki/U-Boot
112 The "official" name of this project is "Das U-Boot". The spelling
113 "U-Boot" shall be used in all written text (documentation, comments
114 in source files etc.). Example:
116 This is the README file for the U-Boot project.
118 File names etc. shall be based on the string "u-boot". Examples:
120 include/asm-ppc/u-boot.h
122 #include <asm/u-boot.h>
124 Variable names, preprocessor constants etc. shall be either based on
125 the string "u_boot" or on "U_BOOT". Example:
127 U_BOOT_VERSION u_boot_logo
128 IH_OS_U_BOOT u_boot_hush_start
134 Starting with the release in October 2008, the names of the releases
135 were changed from numerical release numbers without deeper meaning
136 into a time stamp based numbering. Regular releases are identified by
137 names consisting of the calendar year and month of the release date.
138 Additional fields (if present) indicate release candidates or bug fix
139 releases in "stable" maintenance trees.
142 U-Boot v2009.11 - Release November 2009
143 U-Boot v2009.11.1 - Release 1 in version November 2009 stable tree
144 U-Boot v2010.09-rc1 - Release candiate 1 for September 2010 release
150 /arch Architecture specific files
151 /arm Files generic to ARM architecture
152 /cpu CPU specific files
153 /arm720t Files specific to ARM 720 CPUs
154 /arm920t Files specific to ARM 920 CPUs
155 /at91 Files specific to Atmel AT91RM9200 CPU
156 /imx Files specific to Freescale MC9328 i.MX CPUs
157 /s3c24x0 Files specific to Samsung S3C24X0 CPUs
158 /arm925t Files specific to ARM 925 CPUs
159 /arm926ejs Files specific to ARM 926 CPUs
160 /arm1136 Files specific to ARM 1136 CPUs
161 /ixp Files specific to Intel XScale IXP CPUs
162 /pxa Files specific to Intel XScale PXA CPUs
163 /s3c44b0 Files specific to Samsung S3C44B0 CPUs
164 /sa1100 Files specific to Intel StrongARM SA1100 CPUs
165 /lib Architecture specific library files
166 /avr32 Files generic to AVR32 architecture
167 /cpu CPU specific files
168 /lib Architecture specific library files
169 /blackfin Files generic to Analog Devices Blackfin architecture
170 /cpu CPU specific files
171 /lib Architecture specific library files
172 /x86 Files generic to x86 architecture
173 /cpu CPU specific files
174 /lib Architecture specific library files
175 /m68k Files generic to m68k architecture
176 /cpu CPU specific files
177 /mcf52x2 Files specific to Freescale ColdFire MCF52x2 CPUs
178 /mcf5227x Files specific to Freescale ColdFire MCF5227x CPUs
179 /mcf532x Files specific to Freescale ColdFire MCF5329 CPUs
180 /mcf5445x Files specific to Freescale ColdFire MCF5445x CPUs
181 /mcf547x_8x Files specific to Freescale ColdFire MCF547x_8x CPUs
182 /lib Architecture specific library files
183 /microblaze Files generic to microblaze architecture
184 /cpu CPU specific files
185 /lib Architecture specific library files
186 /mips Files generic to MIPS architecture
187 /cpu CPU specific files
188 /mips32 Files specific to MIPS32 CPUs
189 /xburst Files specific to Ingenic XBurst CPUs
190 /lib Architecture specific library files
191 /nds32 Files generic to NDS32 architecture
192 /cpu CPU specific files
193 /n1213 Files specific to Andes Technology N1213 CPUs
194 /lib Architecture specific library files
195 /nios2 Files generic to Altera NIOS2 architecture
196 /cpu CPU specific files
197 /lib Architecture specific library files
198 /powerpc Files generic to PowerPC architecture
199 /cpu CPU specific files
200 /74xx_7xx Files specific to Freescale MPC74xx and 7xx CPUs
201 /mpc5xx Files specific to Freescale MPC5xx CPUs
202 /mpc5xxx Files specific to Freescale MPC5xxx CPUs
203 /mpc8xx Files specific to Freescale MPC8xx CPUs
204 /mpc8220 Files specific to Freescale MPC8220 CPUs
205 /mpc824x Files specific to Freescale MPC824x CPUs
206 /mpc8260 Files specific to Freescale MPC8260 CPUs
207 /mpc85xx Files specific to Freescale MPC85xx CPUs
208 /ppc4xx Files specific to AMCC PowerPC 4xx CPUs
209 /lib Architecture specific library files
210 /sh Files generic to SH architecture
211 /cpu CPU specific files
212 /sh2 Files specific to sh2 CPUs
213 /sh3 Files specific to sh3 CPUs
214 /sh4 Files specific to sh4 CPUs
215 /lib Architecture specific library files
216 /sparc Files generic to SPARC architecture
217 /cpu CPU specific files
218 /leon2 Files specific to Gaisler LEON2 SPARC CPU
219 /leon3 Files specific to Gaisler LEON3 SPARC CPU
220 /lib Architecture specific library files
221 /api Machine/arch independent API for external apps
222 /board Board dependent files
223 /common Misc architecture independent functions
224 /disk Code for disk drive partition handling
225 /doc Documentation (don't expect too much)
226 /drivers Commonly used device drivers
227 /examples Example code for standalone applications, etc.
228 /fs Filesystem code (cramfs, ext2, jffs2, etc.)
229 /include Header Files
230 /lib Files generic to all architectures
231 /libfdt Library files to support flattened device trees
232 /lzma Library files to support LZMA decompression
233 /lzo Library files to support LZO decompression
235 /post Power On Self Test
236 /rtc Real Time Clock drivers
237 /tools Tools to build S-Record or U-Boot images, etc.
239 Software Configuration:
240 =======================
242 Configuration is usually done using C preprocessor defines; the
243 rationale behind that is to avoid dead code whenever possible.
245 There are two classes of configuration variables:
247 * Configuration _OPTIONS_:
248 These are selectable by the user and have names beginning with
251 * Configuration _SETTINGS_:
252 These depend on the hardware etc. and should not be meddled with if
253 you don't know what you're doing; they have names beginning with
256 Later we will add a configuration tool - probably similar to or even
257 identical to what's used for the Linux kernel. Right now, we have to
258 do the configuration by hand, which means creating some symbolic
259 links and editing some configuration files. We use the TQM8xxL boards
263 Selection of Processor Architecture and Board Type:
264 ---------------------------------------------------
266 For all supported boards there are ready-to-use default
267 configurations available; just type "make <board_name>_config".
269 Example: For a TQM823L module type:
274 For the Cogent platform, you need to specify the CPU type as well;
275 e.g. "make cogent_mpc8xx_config". And also configure the cogent
276 directory according to the instructions in cogent/README.
279 Configuration Options:
280 ----------------------
282 Configuration depends on the combination of board and CPU type; all
283 such information is kept in a configuration file
284 "include/configs/<board_name>.h".
286 Example: For a TQM823L module, all configuration settings are in
287 "include/configs/TQM823L.h".
290 Many of the options are named exactly as the corresponding Linux
291 kernel configuration options. The intention is to make it easier to
292 build a config tool - later.
295 The following options need to be configured:
297 - CPU Type: Define exactly one, e.g. CONFIG_MPC85XX.
299 - Board Type: Define exactly one, e.g. CONFIG_MPC8540ADS.
301 - CPU Daughterboard Type: (if CONFIG_ATSTK1000 is defined)
302 Define exactly one, e.g. CONFIG_ATSTK1002
304 - CPU Module Type: (if CONFIG_COGENT is defined)
305 Define exactly one of
307 --- FIXME --- not tested yet:
308 CONFIG_CMA286_60, CONFIG_CMA286_21, CONFIG_CMA286_60P,
309 CONFIG_CMA287_23, CONFIG_CMA287_50
311 - Motherboard Type: (if CONFIG_COGENT is defined)
312 Define exactly one of
313 CONFIG_CMA101, CONFIG_CMA102
315 - Motherboard I/O Modules: (if CONFIG_COGENT is defined)
316 Define one or more of
319 - Motherboard Options: (if CONFIG_CMA101 or CONFIG_CMA102 are defined)
320 Define one or more of
321 CONFIG_LCD_HEARTBEAT - update a character position on
322 the LCD display every second with
325 - Board flavour: (if CONFIG_MPC8260ADS is defined)
328 CONFIG_SYS_8260ADS - original MPC8260ADS
329 CONFIG_SYS_8266ADS - MPC8266ADS
330 CONFIG_SYS_PQ2FADS - PQ2FADS-ZU or PQ2FADS-VR
331 CONFIG_SYS_8272ADS - MPC8272ADS
333 - Marvell Family Member
334 CONFIG_SYS_MVFS - define it if you want to enable
335 multiple fs option at one time
336 for marvell soc family
338 - MPC824X Family Member (if CONFIG_MPC824X is defined)
339 Define exactly one of
340 CONFIG_MPC8240, CONFIG_MPC8245
342 - 8xx CPU Options: (if using an MPC8xx CPU)
343 CONFIG_8xx_GCLK_FREQ - deprecated: CPU clock if
344 get_gclk_freq() cannot work
345 e.g. if there is no 32KHz
346 reference PIT/RTC clock
347 CONFIG_8xx_OSCLK - PLL input clock (either EXTCLK
350 - 859/866/885 CPU options: (if using a MPC859 or MPC866 or MPC885 CPU):
351 CONFIG_SYS_8xx_CPUCLK_MIN
352 CONFIG_SYS_8xx_CPUCLK_MAX
353 CONFIG_8xx_CPUCLK_DEFAULT
354 See doc/README.MPC866
356 CONFIG_SYS_MEASURE_CPUCLK
358 Define this to measure the actual CPU clock instead
359 of relying on the correctness of the configured
360 values. Mostly useful for board bringup to make sure
361 the PLL is locked at the intended frequency. Note
362 that this requires a (stable) reference clock (32 kHz
363 RTC clock or CONFIG_SYS_8XX_XIN)
365 CONFIG_SYS_DELAYED_ICACHE
367 Define this option if you want to enable the
368 ICache only when Code runs from RAM.
373 Specifies that the core is a 64-bit PowerPC implementation (implements
374 the "64" category of the Power ISA). This is necessary for ePAPR
375 compliance, among other possible reasons.
377 CONFIG_SYS_FSL_TBCLK_DIV
379 Defines the core time base clock divider ratio compared to the
380 system clock. On most PQ3 devices this is 8, on newer QorIQ
381 devices it can be 16 or 32. The ratio varies from SoC to Soc.
383 CONFIG_SYS_FSL_PCIE_COMPAT
385 Defines the string to utilize when trying to match PCIe device
386 tree nodes for the given platform.
388 CONFIG_SYS_PPC_E500_DEBUG_TLB
390 Enables a temporary TLB entry to be used during boot to work
391 around limitations in e500v1 and e500v2 external debugger
392 support. This reduces the portions of the boot code where
393 breakpoints and single stepping do not work. The value of this
394 symbol should be set to the TLB1 entry to be used for this
397 CONFIG_SYS_FSL_ERRATUM_A004510
399 Enables a workaround for erratum A004510. If set,
400 then CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV and
401 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY must be set.
403 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV
404 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV2 (optional)
406 Defines one or two SoC revisions (low 8 bits of SVR)
407 for which the A004510 workaround should be applied.
409 The rest of SVR is either not relevant to the decision
410 of whether the erratum is present (e.g. p2040 versus
411 p2041) or is implied by the build target, which controls
412 whether CONFIG_SYS_FSL_ERRATUM_A004510 is set.
414 See Freescale App Note 4493 for more information about
417 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY
419 This is the value to write into CCSR offset 0x18600
420 according to the A004510 workaround.
422 - Generic CPU options:
423 CONFIG_SYS_BIG_ENDIAN, CONFIG_SYS_LITTLE_ENDIAN
425 Defines the endianess of the CPU. Implementation of those
426 values is arch specific.
428 - Intel Monahans options:
429 CONFIG_SYS_MONAHANS_RUN_MODE_OSC_RATIO
431 Defines the Monahans run mode to oscillator
432 ratio. Valid values are 8, 16, 24, 31. The core
433 frequency is this value multiplied by 13 MHz.
435 CONFIG_SYS_MONAHANS_TURBO_RUN_MODE_RATIO
437 Defines the Monahans turbo mode to oscillator
438 ratio. Valid values are 1 (default if undefined) and
439 2. The core frequency as calculated above is multiplied
443 CONFIG_SYS_INIT_SP_OFFSET
445 Offset relative to CONFIG_SYS_SDRAM_BASE for initial stack
446 pointer. This is needed for the temporary stack before
449 CONFIG_SYS_MIPS_CACHE_MODE
451 Cache operation mode for the MIPS CPU.
452 See also arch/mips/include/asm/mipsregs.h.
454 CONF_CM_CACHABLE_NO_WA
457 CONF_CM_CACHABLE_NONCOHERENT
461 CONF_CM_CACHABLE_ACCELERATED
463 CONFIG_SYS_XWAY_EBU_BOOTCFG
465 Special option for Lantiq XWAY SoCs for booting from NOR flash.
466 See also arch/mips/cpu/mips32/start.S.
468 CONFIG_XWAY_SWAP_BYTES
470 Enable compilation of tools/xway-swap-bytes needed for Lantiq
471 XWAY SoCs for booting from NOR flash. The U-Boot image needs to
472 be swapped if a flash programmer is used.
475 CONFIG_SYS_EXCEPTION_VECTORS_HIGH
477 Select high exception vectors of the ARM core, e.g., do not
478 clear the V bit of the c1 register of CP15.
480 CONFIG_SYS_THUMB_BUILD
482 Use this flag to build U-Boot using the Thumb instruction
483 set for ARM architectures. Thumb instruction set provides
484 better code density. For ARM architectures that support
485 Thumb2 this flag will result in Thumb2 code generated by
488 - Linux Kernel Interface:
491 U-Boot stores all clock information in Hz
492 internally. For binary compatibility with older Linux
493 kernels (which expect the clocks passed in the
494 bd_info data to be in MHz) the environment variable
495 "clocks_in_mhz" can be defined so that U-Boot
496 converts clock data to MHZ before passing it to the
498 When CONFIG_CLOCKS_IN_MHZ is defined, a definition of
499 "clocks_in_mhz=1" is automatically included in the
502 CONFIG_MEMSIZE_IN_BYTES [relevant for MIPS only]
504 When transferring memsize parameter to linux, some versions
505 expect it to be in bytes, others in MB.
506 Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes.
510 New kernel versions are expecting firmware settings to be
511 passed using flattened device trees (based on open firmware
515 * New libfdt-based support
516 * Adds the "fdt" command
517 * The bootm command automatically updates the fdt
519 OF_CPU - The proper name of the cpus node (only required for
520 MPC512X and MPC5xxx based boards).
521 OF_SOC - The proper name of the soc node (only required for
522 MPC512X and MPC5xxx based boards).
523 OF_TBCLK - The timebase frequency.
524 OF_STDOUT_PATH - The path to the console device
526 boards with QUICC Engines require OF_QE to set UCC MAC
529 CONFIG_OF_BOARD_SETUP
531 Board code has addition modification that it wants to make
532 to the flat device tree before handing it off to the kernel
536 This define fills in the correct boot CPU in the boot
537 param header, the default value is zero if undefined.
541 U-Boot can detect if an IDE device is present or not.
542 If not, and this new config option is activated, U-Boot
543 removes the ATA node from the DTS before booting Linux,
544 so the Linux IDE driver does not probe the device and
545 crash. This is needed for buggy hardware (uc101) where
546 no pull down resistor is connected to the signal IDE5V_DD7.
548 CONFIG_MACH_TYPE [relevant for ARM only][mandatory]
550 This setting is mandatory for all boards that have only one
551 machine type and must be used to specify the machine type
552 number as it appears in the ARM machine registry
553 (see http://www.arm.linux.org.uk/developer/machines/).
554 Only boards that have multiple machine types supported
555 in a single configuration file and the machine type is
556 runtime discoverable, do not have to use this setting.
558 - vxWorks boot parameters:
560 bootvx constructs a valid bootline using the following
561 environments variables: bootfile, ipaddr, serverip, hostname.
562 It loads the vxWorks image pointed bootfile.
564 CONFIG_SYS_VXWORKS_BOOT_DEVICE - The vxworks device name
565 CONFIG_SYS_VXWORKS_MAC_PTR - Ethernet 6 byte MA -address
566 CONFIG_SYS_VXWORKS_SERVERNAME - Name of the server
567 CONFIG_SYS_VXWORKS_BOOT_ADDR - Address of boot parameters
569 CONFIG_SYS_VXWORKS_ADD_PARAMS
571 Add it at the end of the bootline. E.g "u=username pw=secret"
573 Note: If a "bootargs" environment is defined, it will overwride
574 the defaults discussed just above.
576 - Cache Configuration:
577 CONFIG_SYS_ICACHE_OFF - Do not enable instruction cache in U-Boot
578 CONFIG_SYS_DCACHE_OFF - Do not enable data cache in U-Boot
579 CONFIG_SYS_L2CACHE_OFF- Do not enable L2 cache in U-Boot
581 - Cache Configuration for ARM:
582 CONFIG_SYS_L2_PL310 - Enable support for ARM PL310 L2 cache
584 CONFIG_SYS_PL310_BASE - Physical base address of PL310
585 controller register space
590 Define this if you want support for Amba PrimeCell PL010 UARTs.
594 Define this if you want support for Amba PrimeCell PL011 UARTs.
598 If you have Amba PrimeCell PL011 UARTs, set this variable to
599 the clock speed of the UARTs.
603 If you have Amba PrimeCell PL010 or PL011 UARTs on your board,
604 define this to a list of base addresses for each (supported)
605 port. See e.g. include/configs/versatile.h
607 CONFIG_PL011_SERIAL_RLCR
609 Some vendor versions of PL011 serial ports (e.g. ST-Ericsson U8500)
610 have separate receive and transmit line control registers. Set
611 this variable to initialize the extra register.
613 CONFIG_PL011_SERIAL_FLUSH_ON_INIT
615 On some platforms (e.g. U8500) U-Boot is loaded by a second stage
616 boot loader that has already initialized the UART. Define this
617 variable to flush the UART at init time.
621 Depending on board, define exactly one serial port
622 (like CONFIG_8xx_CONS_SMC1, CONFIG_8xx_CONS_SMC2,
623 CONFIG_8xx_CONS_SCC1, ...), or switch off the serial
624 console by defining CONFIG_8xx_CONS_NONE
626 Note: if CONFIG_8xx_CONS_NONE is defined, the serial
627 port routines must be defined elsewhere
628 (i.e. serial_init(), serial_getc(), ...)
631 Enables console device for a color framebuffer. Needs following
632 defines (cf. smiLynxEM, i8042)
633 VIDEO_FB_LITTLE_ENDIAN graphic memory organisation
635 VIDEO_HW_RECTFILL graphic chip supports
638 VIDEO_HW_BITBLT graphic chip supports
639 bit-blit (cf. smiLynxEM)
640 VIDEO_VISIBLE_COLS visible pixel columns
642 VIDEO_VISIBLE_ROWS visible pixel rows
643 VIDEO_PIXEL_SIZE bytes per pixel
644 VIDEO_DATA_FORMAT graphic data format
645 (0-5, cf. cfb_console.c)
646 VIDEO_FB_ADRS framebuffer address
647 VIDEO_KBD_INIT_FCT keyboard int fct
648 (i.e. i8042_kbd_init())
649 VIDEO_TSTC_FCT test char fct
651 VIDEO_GETC_FCT get char fct
653 CONFIG_CONSOLE_CURSOR cursor drawing on/off
654 (requires blink timer
656 CONFIG_SYS_CONSOLE_BLINK_COUNT blink interval (cf. i8042.c)
657 CONFIG_CONSOLE_TIME display time/date info in
659 (requires CONFIG_CMD_DATE)
660 CONFIG_VIDEO_LOGO display Linux logo in
662 CONFIG_VIDEO_BMP_LOGO use bmp_logo.h instead of
663 linux_logo.h for logo.
664 Requires CONFIG_VIDEO_LOGO
665 CONFIG_CONSOLE_EXTRA_INFO
666 additional board info beside
669 When CONFIG_CFB_CONSOLE_ANSI is defined, console will support
670 a limited number of ANSI escape sequences (cursor control,
671 erase functions and limited graphics rendition control).
673 When CONFIG_CFB_CONSOLE is defined, video console is
674 default i/o. Serial console can be forced with
675 environment 'console=serial'.
677 When CONFIG_SILENT_CONSOLE is defined, all console
678 messages (by U-Boot and Linux!) can be silenced with
679 the "silent" environment variable. See
680 doc/README.silent for more information.
683 CONFIG_BAUDRATE - in bps
684 Select one of the baudrates listed in
685 CONFIG_SYS_BAUDRATE_TABLE, see below.
686 CONFIG_SYS_BRGCLK_PRESCALE, baudrate prescale
688 - Console Rx buffer length
689 With CONFIG_SYS_SMC_RXBUFLEN it is possible to define
690 the maximum receive buffer length for the SMC.
691 This option is actual only for 82xx and 8xx possible.
692 If using CONFIG_SYS_SMC_RXBUFLEN also CONFIG_SYS_MAXIDLE
693 must be defined, to setup the maximum idle timeout for
696 - Pre-Console Buffer:
697 Prior to the console being initialised (i.e. serial UART
698 initialised etc) all console output is silently discarded.
699 Defining CONFIG_PRE_CONSOLE_BUFFER will cause U-Boot to
700 buffer any console messages prior to the console being
701 initialised to a buffer of size CONFIG_PRE_CON_BUF_SZ
702 bytes located at CONFIG_PRE_CON_BUF_ADDR. The buffer is
703 a circular buffer, so if more than CONFIG_PRE_CON_BUF_SZ
704 bytes are output before the console is initialised, the
705 earlier bytes are discarded.
707 'Sane' compilers will generate smaller code if
708 CONFIG_PRE_CON_BUF_SZ is a power of 2
710 - Safe printf() functions
711 Define CONFIG_SYS_VSNPRINTF to compile in safe versions of
712 the printf() functions. These are defined in
713 include/vsprintf.h and include snprintf(), vsnprintf() and
714 so on. Code size increase is approximately 300-500 bytes.
715 If this option is not given then these functions will
716 silently discard their buffer size argument - this means
717 you are not getting any overflow checking in this case.
719 - Boot Delay: CONFIG_BOOTDELAY - in seconds
720 Delay before automatically booting the default image;
721 set to -1 to disable autoboot.
722 set to -2 to autoboot with no delay and not check for abort
723 (even when CONFIG_ZERO_BOOTDELAY_CHECK is defined).
725 See doc/README.autoboot for these options that
726 work with CONFIG_BOOTDELAY. None are required.
727 CONFIG_BOOT_RETRY_TIME
728 CONFIG_BOOT_RETRY_MIN
729 CONFIG_AUTOBOOT_KEYED
730 CONFIG_AUTOBOOT_PROMPT
731 CONFIG_AUTOBOOT_DELAY_STR
732 CONFIG_AUTOBOOT_STOP_STR
733 CONFIG_AUTOBOOT_DELAY_STR2
734 CONFIG_AUTOBOOT_STOP_STR2
735 CONFIG_ZERO_BOOTDELAY_CHECK
736 CONFIG_RESET_TO_RETRY
740 Only needed when CONFIG_BOOTDELAY is enabled;
741 define a command string that is automatically executed
742 when no character is read on the console interface
743 within "Boot Delay" after reset.
746 This can be used to pass arguments to the bootm
747 command. The value of CONFIG_BOOTARGS goes into the
748 environment value "bootargs".
750 CONFIG_RAMBOOT and CONFIG_NFSBOOT
751 The value of these goes into the environment as
752 "ramboot" and "nfsboot" respectively, and can be used
753 as a convenience, when switching between booting from
759 When this option is #defined, the existence of the
760 environment variable "preboot" will be checked
761 immediately before starting the CONFIG_BOOTDELAY
762 countdown and/or running the auto-boot command resp.
763 entering interactive mode.
765 This feature is especially useful when "preboot" is
766 automatically generated or modified. For an example
767 see the LWMON board specific code: here "preboot" is
768 modified when the user holds down a certain
769 combination of keys on the (special) keyboard when
772 - Serial Download Echo Mode:
774 If defined to 1, all characters received during a
775 serial download (using the "loads" command) are
776 echoed back. This might be needed by some terminal
777 emulations (like "cu"), but may as well just take
778 time on others. This setting #define's the initial
779 value of the "loads_echo" environment variable.
781 - Kgdb Serial Baudrate: (if CONFIG_CMD_KGDB is defined)
783 Select one of the baudrates listed in
784 CONFIG_SYS_BAUDRATE_TABLE, see below.
787 Monitor commands can be included or excluded
788 from the build by using the #include files
789 <config_cmd_all.h> and #undef'ing unwanted
790 commands, or using <config_cmd_default.h>
791 and augmenting with additional #define's
794 The default command configuration includes all commands
795 except those marked below with a "*".
797 CONFIG_CMD_ASKENV * ask for env variable
798 CONFIG_CMD_BDI bdinfo
799 CONFIG_CMD_BEDBUG * Include BedBug Debugger
800 CONFIG_CMD_BMP * BMP support
801 CONFIG_CMD_BSP * Board specific commands
802 CONFIG_CMD_BOOTD bootd
803 CONFIG_CMD_CACHE * icache, dcache
804 CONFIG_CMD_CONSOLE coninfo
805 CONFIG_CMD_CRC32 * crc32
806 CONFIG_CMD_DATE * support for RTC, date/time...
807 CONFIG_CMD_DHCP * DHCP support
808 CONFIG_CMD_DIAG * Diagnostics
809 CONFIG_CMD_DS4510 * ds4510 I2C gpio commands
810 CONFIG_CMD_DS4510_INFO * ds4510 I2C info command
811 CONFIG_CMD_DS4510_MEM * ds4510 I2C eeprom/sram commansd
812 CONFIG_CMD_DS4510_RST * ds4510 I2C rst command
813 CONFIG_CMD_DTT * Digital Therm and Thermostat
814 CONFIG_CMD_ECHO echo arguments
815 CONFIG_CMD_EDITENV edit env variable
816 CONFIG_CMD_EEPROM * EEPROM read/write support
817 CONFIG_CMD_ELF * bootelf, bootvx
818 CONFIG_CMD_EXPORTENV * export the environment
819 CONFIG_CMD_EXT2 * ext2 command support
820 CONFIG_CMD_EXT4 * ext4 command support
821 CONFIG_CMD_SAVEENV saveenv
822 CONFIG_CMD_FDC * Floppy Disk Support
823 CONFIG_CMD_FAT * FAT command support
824 CONFIG_CMD_FDOS * Dos diskette Support
825 CONFIG_CMD_FLASH flinfo, erase, protect
826 CONFIG_CMD_FPGA FPGA device initialization support
827 CONFIG_CMD_GO * the 'go' command (exec code)
828 CONFIG_CMD_GREPENV * search environment
829 CONFIG_CMD_HWFLOW * RTS/CTS hw flow control
830 CONFIG_CMD_I2C * I2C serial bus support
831 CONFIG_CMD_IDE * IDE harddisk support
832 CONFIG_CMD_IMI iminfo
833 CONFIG_CMD_IMLS List all found images
834 CONFIG_CMD_IMMAP * IMMR dump support
835 CONFIG_CMD_IMPORTENV * import an environment
836 CONFIG_CMD_INI * import data from an ini file into the env
837 CONFIG_CMD_IRQ * irqinfo
838 CONFIG_CMD_ITEST Integer/string test of 2 values
839 CONFIG_CMD_JFFS2 * JFFS2 Support
840 CONFIG_CMD_KGDB * kgdb
841 CONFIG_CMD_LDRINFO ldrinfo (display Blackfin loader)
842 CONFIG_CMD_LINK_LOCAL * link-local IP address auto-configuration
844 CONFIG_CMD_LOADB loadb
845 CONFIG_CMD_LOADS loads
846 CONFIG_CMD_MD5SUM print md5 message digest
847 (requires CONFIG_CMD_MEMORY and CONFIG_MD5)
848 CONFIG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base,
850 CONFIG_CMD_MISC Misc functions like sleep etc
851 CONFIG_CMD_MMC * MMC memory mapped support
852 CONFIG_CMD_MII * MII utility commands
853 CONFIG_CMD_MTDPARTS * MTD partition support
854 CONFIG_CMD_NAND * NAND support
855 CONFIG_CMD_NET bootp, tftpboot, rarpboot
856 CONFIG_CMD_PCA953X * PCA953x I2C gpio commands
857 CONFIG_CMD_PCA953X_INFO * PCA953x I2C gpio info command
858 CONFIG_CMD_PCI * pciinfo
859 CONFIG_CMD_PCMCIA * PCMCIA support
860 CONFIG_CMD_PING * send ICMP ECHO_REQUEST to network
862 CONFIG_CMD_PORTIO * Port I/O
863 CONFIG_CMD_REGINFO * Register dump
864 CONFIG_CMD_RUN run command in env variable
865 CONFIG_CMD_SAVES * save S record dump
866 CONFIG_CMD_SCSI * SCSI Support
867 CONFIG_CMD_SDRAM * print SDRAM configuration information
868 (requires CONFIG_CMD_I2C)
869 CONFIG_CMD_SETGETDCR Support for DCR Register access
871 CONFIG_CMD_SF * Read/write/erase SPI NOR flash
872 CONFIG_CMD_SHA1SUM print sha1 memory digest
873 (requires CONFIG_CMD_MEMORY)
874 CONFIG_CMD_SOURCE "source" command Support
875 CONFIG_CMD_SPI * SPI serial bus support
876 CONFIG_CMD_TFTPSRV * TFTP transfer in server mode
877 CONFIG_CMD_TFTPPUT * TFTP put command (upload)
878 CONFIG_CMD_TIME * run command and report execution time (ARM specific)
879 CONFIG_CMD_TIMER * access to the system tick timer
880 CONFIG_CMD_USB * USB support
881 CONFIG_CMD_CDP * Cisco Discover Protocol support
882 CONFIG_CMD_MFSL * Microblaze FSL support
885 EXAMPLE: If you want all functions except of network
886 support you can write:
888 #include "config_cmd_all.h"
889 #undef CONFIG_CMD_NET
892 fdt (flattened device tree) command: CONFIG_OF_LIBFDT
894 Note: Don't enable the "icache" and "dcache" commands
895 (configuration option CONFIG_CMD_CACHE) unless you know
896 what you (and your U-Boot users) are doing. Data
897 cache cannot be enabled on systems like the 8xx or
898 8260 (where accesses to the IMMR region must be
899 uncached), and it cannot be disabled on all other
900 systems where we (mis-) use the data cache to hold an
901 initial stack and some data.
904 XXX - this list needs to get updated!
908 If this variable is defined, U-Boot will use a device tree
909 to configure its devices, instead of relying on statically
910 compiled #defines in the board file. This option is
911 experimental and only available on a few boards. The device
912 tree is available in the global data as gd->fdt_blob.
914 U-Boot needs to get its device tree from somewhere. This can
915 be done using one of the two options below:
918 If this variable is defined, U-Boot will embed a device tree
919 binary in its image. This device tree file should be in the
920 board directory and called <soc>-<board>.dts. The binary file
921 is then picked up in board_init_f() and made available through
922 the global data structure as gd->blob.
925 If this variable is defined, U-Boot will build a device tree
926 binary. It will be called u-boot.dtb. Architecture-specific
927 code will locate it at run-time. Generally this works by:
929 cat u-boot.bin u-boot.dtb >image.bin
931 and in fact, U-Boot does this for you, creating a file called
932 u-boot-dtb.bin which is useful in the common case. You can
933 still use the individual files if you need something more
938 If this variable is defined, it enables watchdog
939 support for the SoC. There must be support in the SoC
940 specific code for a watchdog. For the 8xx and 8260
941 CPUs, the SIU Watchdog feature is enabled in the SYPCR
942 register. When supported for a specific SoC is
943 available, then no further board specific code should
947 When using a watchdog circuitry external to the used
948 SoC, then define this variable and provide board
949 specific code for the "hw_watchdog_reset" function.
952 CONFIG_VERSION_VARIABLE
953 If this variable is defined, an environment variable
954 named "ver" is created by U-Boot showing the U-Boot
955 version as printed by the "version" command.
956 Any change to this variable will be reverted at the
961 When CONFIG_CMD_DATE is selected, the type of the RTC
962 has to be selected, too. Define exactly one of the
965 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx
966 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC
967 CONFIG_RTC_MC13XXX - use MC13783 or MC13892 RTC
968 CONFIG_RTC_MC146818 - use MC146818 RTC
969 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC
970 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC
971 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC
972 CONFIG_RTC_DS164x - use Dallas DS164x RTC
973 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC
974 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC
975 CONFIG_SYS_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337
976 CONFIG_SYS_RV3029_TCR - enable trickle charger on
979 Note that if the RTC uses I2C, then the I2C interface
980 must also be configured. See I2C Support, below.
983 CONFIG_PCA953X - use NXP's PCA953X series I2C GPIO
984 CONFIG_PCA953X_INFO - enable pca953x info command
986 The CONFIG_SYS_I2C_PCA953X_WIDTH option specifies a list of
987 chip-ngpio pairs that tell the PCA953X driver the number of
988 pins supported by a particular chip.
990 Note that if the GPIO device uses I2C, then the I2C interface
991 must also be configured. See I2C Support, below.
995 When CONFIG_TIMESTAMP is selected, the timestamp
996 (date and time) of an image is printed by image
997 commands like bootm or iminfo. This option is
998 automatically enabled when you select CONFIG_CMD_DATE .
1000 - Partition Labels (disklabels) Supported:
1001 Zero or more of the following:
1002 CONFIG_MAC_PARTITION Apple's MacOS partition table.
1003 CONFIG_DOS_PARTITION MS Dos partition table, traditional on the
1004 Intel architecture, USB sticks, etc.
1005 CONFIG_ISO_PARTITION ISO partition table, used on CDROM etc.
1006 CONFIG_EFI_PARTITION GPT partition table, common when EFI is the
1007 bootloader. Note 2TB partition limit; see
1009 CONFIG_MTD_PARTITIONS Memory Technology Device partition table.
1011 If IDE or SCSI support is enabled (CONFIG_CMD_IDE or
1012 CONFIG_CMD_SCSI) you must configure support for at
1013 least one non-MTD partition type as well.
1016 CONFIG_IDE_RESET_ROUTINE - this is defined in several
1017 board configurations files but used nowhere!
1019 CONFIG_IDE_RESET - is this is defined, IDE Reset will
1020 be performed by calling the function
1021 ide_set_reset(int reset)
1022 which has to be defined in a board specific file
1027 Set this to enable ATAPI support.
1032 Set this to enable support for disks larger than 137GB
1033 Also look at CONFIG_SYS_64BIT_LBA.
1034 Whithout these , LBA48 support uses 32bit variables and will 'only'
1035 support disks up to 2.1TB.
1037 CONFIG_SYS_64BIT_LBA:
1038 When enabled, makes the IDE subsystem use 64bit sector addresses.
1042 At the moment only there is only support for the
1043 SYM53C8XX SCSI controller; define
1044 CONFIG_SCSI_SYM53C8XX to enable it.
1046 CONFIG_SYS_SCSI_MAX_LUN [8], CONFIG_SYS_SCSI_MAX_SCSI_ID [7] and
1047 CONFIG_SYS_SCSI_MAX_DEVICE [CONFIG_SYS_SCSI_MAX_SCSI_ID *
1048 CONFIG_SYS_SCSI_MAX_LUN] can be adjusted to define the
1049 maximum numbers of LUNs, SCSI ID's and target
1051 CONFIG_SYS_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz)
1053 The environment variable 'scsidevs' is set to the number of
1054 SCSI devices found during the last scan.
1056 - NETWORK Support (PCI):
1058 Support for Intel 8254x/8257x gigabit chips.
1061 Utility code for direct access to the SPI bus on Intel 8257x.
1062 This does not do anything useful unless you set at least one
1063 of CONFIG_CMD_E1000 or CONFIG_E1000_SPI_GENERIC.
1065 CONFIG_E1000_SPI_GENERIC
1066 Allow generic access to the SPI bus on the Intel 8257x, for
1067 example with the "sspi" command.
1070 Management command for E1000 devices. When used on devices
1071 with SPI support you can reprogram the EEPROM from U-Boot.
1073 CONFIG_E1000_FALLBACK_MAC
1074 default MAC for empty EEPROM after production.
1077 Support for Intel 82557/82559/82559ER chips.
1078 Optional CONFIG_EEPRO100_SROM_WRITE enables EEPROM
1079 write routine for first time initialisation.
1082 Support for Digital 2114x chips.
1083 Optional CONFIG_TULIP_SELECT_MEDIA for board specific
1084 modem chip initialisation (KS8761/QS6611).
1087 Support for National dp83815 chips.
1090 Support for National dp8382[01] gigabit chips.
1092 - NETWORK Support (other):
1094 CONFIG_DRIVER_AT91EMAC
1095 Support for AT91RM9200 EMAC.
1098 Define this to use reduced MII inteface
1100 CONFIG_DRIVER_AT91EMAC_QUIET
1101 If this defined, the driver is quiet.
1102 The driver doen't show link status messages.
1104 CONFIG_CALXEDA_XGMAC
1105 Support for the Calxeda XGMAC device
1108 Support for SMSC's LAN91C96 chips.
1110 CONFIG_LAN91C96_BASE
1111 Define this to hold the physical address
1112 of the LAN91C96's I/O space
1114 CONFIG_LAN91C96_USE_32_BIT
1115 Define this to enable 32 bit addressing
1118 Support for SMSC's LAN91C111 chip
1120 CONFIG_SMC91111_BASE
1121 Define this to hold the physical address
1122 of the device (I/O space)
1124 CONFIG_SMC_USE_32_BIT
1125 Define this if data bus is 32 bits
1127 CONFIG_SMC_USE_IOFUNCS
1128 Define this to use i/o functions instead of macros
1129 (some hardware wont work with macros)
1131 CONFIG_DRIVER_TI_EMAC
1132 Support for davinci emac
1134 CONFIG_SYS_DAVINCI_EMAC_PHY_COUNT
1135 Define this if you have more then 3 PHYs.
1138 Support for Faraday's FTGMAC100 Gigabit SoC Ethernet
1140 CONFIG_FTGMAC100_EGIGA
1141 Define this to use GE link update with gigabit PHY.
1142 Define this if FTGMAC100 is connected to gigabit PHY.
1143 If your system has 10/100 PHY only, it might not occur
1144 wrong behavior. Because PHY usually return timeout or
1145 useless data when polling gigabit status and gigabit
1146 control registers. This behavior won't affect the
1147 correctnessof 10/100 link speed update.
1150 Support for SMSC's LAN911x and LAN921x chips
1153 Define this to hold the physical address
1154 of the device (I/O space)
1156 CONFIG_SMC911X_32_BIT
1157 Define this if data bus is 32 bits
1159 CONFIG_SMC911X_16_BIT
1160 Define this if data bus is 16 bits. If your processor
1161 automatically converts one 32 bit word to two 16 bit
1162 words you may also try CONFIG_SMC911X_32_BIT.
1165 Support for Renesas on-chip Ethernet controller
1167 CONFIG_SH_ETHER_USE_PORT
1168 Define the number of ports to be used
1170 CONFIG_SH_ETHER_PHY_ADDR
1171 Define the ETH PHY's address
1173 CONFIG_SH_ETHER_CACHE_WRITEBACK
1174 If this option is set, the driver enables cache flush.
1177 CONFIG_GENERIC_LPC_TPM
1178 Support for generic parallel port TPM devices. Only one device
1179 per system is supported at this time.
1181 CONFIG_TPM_TIS_BASE_ADDRESS
1182 Base address where the generic TPM device is mapped
1183 to. Contemporary x86 systems usually map it at
1187 At the moment only the UHCI host controller is
1188 supported (PIP405, MIP405, MPC5200); define
1189 CONFIG_USB_UHCI to enable it.
1190 define CONFIG_USB_KEYBOARD to enable the USB Keyboard
1191 and define CONFIG_USB_STORAGE to enable the USB
1194 Supported are USB Keyboards and USB Floppy drives
1196 MPC5200 USB requires additional defines:
1198 for 528 MHz Clock: 0x0001bbbb
1202 for differential drivers: 0x00001000
1203 for single ended drivers: 0x00005000
1204 for differential drivers on PSC3: 0x00000100
1205 for single ended drivers on PSC3: 0x00004100
1206 CONFIG_SYS_USB_EVENT_POLL
1207 May be defined to allow interrupt polling
1208 instead of using asynchronous interrupts
1210 CONFIG_USB_EHCI_TXFIFO_THRESH enables setting of the
1211 txfilltuning field in the EHCI controller on reset.
1214 Define the below if you wish to use the USB console.
1215 Once firmware is rebuilt from a serial console issue the
1216 command "setenv stdin usbtty; setenv stdout usbtty" and
1217 attach your USB cable. The Unix command "dmesg" should print
1218 it has found a new device. The environment variable usbtty
1219 can be set to gserial or cdc_acm to enable your device to
1220 appear to a USB host as a Linux gserial device or a
1221 Common Device Class Abstract Control Model serial device.
1222 If you select usbtty = gserial you should be able to enumerate
1224 # modprobe usbserial vendor=0xVendorID product=0xProductID
1225 else if using cdc_acm, simply setting the environment
1226 variable usbtty to be cdc_acm should suffice. The following
1227 might be defined in YourBoardName.h
1230 Define this to build a UDC device
1233 Define this to have a tty type of device available to
1234 talk to the UDC device
1237 Define this to enable the high speed support for usb
1238 device and usbtty. If this feature is enabled, a routine
1239 int is_usbd_high_speed(void)
1240 also needs to be defined by the driver to dynamically poll
1241 whether the enumeration has succeded at high speed or full
1244 CONFIG_SYS_CONSOLE_IS_IN_ENV
1245 Define this if you want stdin, stdout &/or stderr to
1249 CONFIG_SYS_USB_EXTC_CLK 0xBLAH
1250 Derive USB clock from external clock "blah"
1251 - CONFIG_SYS_USB_EXTC_CLK 0x02
1253 CONFIG_SYS_USB_BRG_CLK 0xBLAH
1254 Derive USB clock from brgclk
1255 - CONFIG_SYS_USB_BRG_CLK 0x04
1257 If you have a USB-IF assigned VendorID then you may wish to
1258 define your own vendor specific values either in BoardName.h
1259 or directly in usbd_vendor_info.h. If you don't define
1260 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME,
1261 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot
1262 should pretend to be a Linux device to it's target host.
1264 CONFIG_USBD_MANUFACTURER
1265 Define this string as the name of your company for
1266 - CONFIG_USBD_MANUFACTURER "my company"
1268 CONFIG_USBD_PRODUCT_NAME
1269 Define this string as the name of your product
1270 - CONFIG_USBD_PRODUCT_NAME "acme usb device"
1272 CONFIG_USBD_VENDORID
1273 Define this as your assigned Vendor ID from the USB
1274 Implementors Forum. This *must* be a genuine Vendor ID
1275 to avoid polluting the USB namespace.
1276 - CONFIG_USBD_VENDORID 0xFFFF
1278 CONFIG_USBD_PRODUCTID
1279 Define this as the unique Product ID
1281 - CONFIG_USBD_PRODUCTID 0xFFFF
1283 - ULPI Layer Support:
1284 The ULPI (UTMI Low Pin (count) Interface) PHYs are supported via
1285 the generic ULPI layer. The generic layer accesses the ULPI PHY
1286 via the platform viewport, so you need both the genric layer and
1287 the viewport enabled. Currently only Chipidea/ARC based
1288 viewport is supported.
1289 To enable the ULPI layer support, define CONFIG_USB_ULPI and
1290 CONFIG_USB_ULPI_VIEWPORT in your board configuration file.
1291 If your ULPI phy needs a different reference clock than the
1292 standard 24 MHz then you have to define CONFIG_ULPI_REF_CLK to
1293 the appropriate value in Hz.
1296 The MMC controller on the Intel PXA is supported. To
1297 enable this define CONFIG_MMC. The MMC can be
1298 accessed from the boot prompt by mapping the device
1299 to physical memory similar to flash. Command line is
1300 enabled with CONFIG_CMD_MMC. The MMC driver also works with
1301 the FAT fs. This is enabled with CONFIG_CMD_FAT.
1304 Support for Renesas on-chip MMCIF controller
1306 CONFIG_SH_MMCIF_ADDR
1307 Define the base address of MMCIF registers
1310 Define the clock frequency for MMCIF
1312 - Journaling Flash filesystem support:
1313 CONFIG_JFFS2_NAND, CONFIG_JFFS2_NAND_OFF, CONFIG_JFFS2_NAND_SIZE,
1314 CONFIG_JFFS2_NAND_DEV
1315 Define these for a default partition on a NAND device
1317 CONFIG_SYS_JFFS2_FIRST_SECTOR,
1318 CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS
1319 Define these for a default partition on a NOR device
1321 CONFIG_SYS_JFFS_CUSTOM_PART
1322 Define this to create an own partition. You have to provide a
1323 function struct part_info* jffs2_part_info(int part_num)
1325 If you define only one JFFS2 partition you may also want to
1326 #define CONFIG_SYS_JFFS_SINGLE_PART 1
1327 to disable the command chpart. This is the default when you
1328 have not defined a custom partition
1330 - FAT(File Allocation Table) filesystem write function support:
1333 Define this to enable support for saving memory data as a
1334 file in FAT formatted partition.
1336 This will also enable the command "fatwrite" enabling the
1337 user to write files to FAT.
1339 CBFS (Coreboot Filesystem) support
1342 Define this to enable support for reading from a Coreboot
1343 filesystem. Available commands are cbfsinit, cbfsinfo, cbfsls
1349 Define this to enable standard (PC-Style) keyboard
1353 Standard PC keyboard driver with US (is default) and
1354 GERMAN key layout (switch via environment 'keymap=de') support.
1355 Export function i8042_kbd_init, i8042_tstc and i8042_getc
1356 for cfb_console. Supports cursor blinking.
1361 Define this to enable video support (for output to
1364 CONFIG_VIDEO_CT69000
1366 Enable Chips & Technologies 69000 Video chip
1368 CONFIG_VIDEO_SMI_LYNXEM
1369 Enable Silicon Motion SMI 712/710/810 Video chip. The
1370 video output is selected via environment 'videoout'
1371 (1 = LCD and 2 = CRT). If videoout is undefined, CRT is
1374 For the CT69000 and SMI_LYNXEM drivers, videomode is
1375 selected via environment 'videomode'. Two different ways
1377 - "videomode=num" 'num' is a standard LiLo mode numbers.
1378 Following standard modes are supported (* is default):
1380 Colors 640x480 800x600 1024x768 1152x864 1280x1024
1381 -------------+---------------------------------------------
1382 8 bits | 0x301* 0x303 0x305 0x161 0x307
1383 15 bits | 0x310 0x313 0x316 0x162 0x319
1384 16 bits | 0x311 0x314 0x317 0x163 0x31A
1385 24 bits | 0x312 0x315 0x318 ? 0x31B
1386 -------------+---------------------------------------------
1387 (i.e. setenv videomode 317; saveenv; reset;)
1389 - "videomode=bootargs" all the video parameters are parsed
1390 from the bootargs. (See drivers/video/videomodes.c)
1393 CONFIG_VIDEO_SED13806
1394 Enable Epson SED13806 driver. This driver supports 8bpp
1395 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP
1396 or CONFIG_VIDEO_SED13806_16BPP
1399 Enable the Freescale DIU video driver. Reference boards for
1400 SOCs that have a DIU should define this macro to enable DIU
1401 support, and should also define these other macros:
1407 CONFIG_VIDEO_SW_CURSOR
1408 CONFIG_VGA_AS_SINGLE_DEVICE
1410 CONFIG_VIDEO_BMP_LOGO
1412 The DIU driver will look for the 'video-mode' environment
1413 variable, and if defined, enable the DIU as a console during
1414 boot. See the documentation file README.video for a
1415 description of this variable.
1419 Enable the VGA video / BIOS for x86. The alternative if you
1420 are using coreboot is to use the coreboot frame buffer
1427 Define this to enable a custom keyboard support.
1428 This simply calls drv_keyboard_init() which must be
1429 defined in your board-specific files.
1430 The only board using this so far is RBC823.
1432 - LCD Support: CONFIG_LCD
1434 Define this to enable LCD support (for output to LCD
1435 display); also select one of the supported displays
1436 by defining one of these:
1440 HITACHI TX09D70VM1CCA, 3.5", 240x320.
1442 CONFIG_NEC_NL6448AC33:
1444 NEC NL6448AC33-18. Active, color, single scan.
1446 CONFIG_NEC_NL6448BC20
1448 NEC NL6448BC20-08. 6.5", 640x480.
1449 Active, color, single scan.
1451 CONFIG_NEC_NL6448BC33_54
1453 NEC NL6448BC33-54. 10.4", 640x480.
1454 Active, color, single scan.
1458 Sharp 320x240. Active, color, single scan.
1459 It isn't 16x9, and I am not sure what it is.
1461 CONFIG_SHARP_LQ64D341
1463 Sharp LQ64D341 display, 640x480.
1464 Active, color, single scan.
1468 HLD1045 display, 640x480.
1469 Active, color, single scan.
1473 Optrex CBL50840-2 NF-FW 99 22 M5
1475 Hitachi LMG6912RPFC-00T
1479 320x240. Black & white.
1481 Normally display is black on white background; define
1482 CONFIG_SYS_WHITE_ON_BLACK to get it inverted.
1486 Support drawing of RLE8-compressed bitmaps on the LCD.
1489 - Splash Screen Support: CONFIG_SPLASH_SCREEN
1491 If this option is set, the environment is checked for
1492 a variable "splashimage". If found, the usual display
1493 of logo, copyright and system information on the LCD
1494 is suppressed and the BMP image at the address
1495 specified in "splashimage" is loaded instead. The
1496 console is redirected to the "nulldev", too. This
1497 allows for a "silent" boot where a splash screen is
1498 loaded very quickly after power-on.
1500 CONFIG_SPLASH_SCREEN_ALIGN
1502 If this option is set the splash image can be freely positioned
1503 on the screen. Environment variable "splashpos" specifies the
1504 position as "x,y". If a positive number is given it is used as
1505 number of pixel from left/top. If a negative number is given it
1506 is used as number of pixel from right/bottom. You can also
1507 specify 'm' for centering the image.
1510 setenv splashpos m,m
1511 => image at center of screen
1513 setenv splashpos 30,20
1514 => image at x = 30 and y = 20
1516 setenv splashpos -10,m
1517 => vertically centered image
1518 at x = dspWidth - bmpWidth - 9
1520 - Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP
1522 If this option is set, additionally to standard BMP
1523 images, gzipped BMP images can be displayed via the
1524 splashscreen support or the bmp command.
1526 - Run length encoded BMP image (RLE8) support: CONFIG_VIDEO_BMP_RLE8
1528 If this option is set, 8-bit RLE compressed BMP images
1529 can be displayed via the splashscreen support or the
1532 - Do compresssing for memory range:
1535 If this option is set, it would use zlib deflate method
1536 to compress the specified memory at its best effort.
1538 - Compression support:
1541 If this option is set, support for bzip2 compressed
1542 images is included. If not, only uncompressed and gzip
1543 compressed images are supported.
1545 NOTE: the bzip2 algorithm requires a lot of RAM, so
1546 the malloc area (as defined by CONFIG_SYS_MALLOC_LEN) should
1551 If this option is set, support for lzma compressed
1554 Note: The LZMA algorithm adds between 2 and 4KB of code and it
1555 requires an amount of dynamic memory that is given by the
1558 (1846 + 768 << (lc + lp)) * sizeof(uint16)
1560 Where lc and lp stand for, respectively, Literal context bits
1561 and Literal pos bits.
1563 This value is upper-bounded by 14MB in the worst case. Anyway,
1564 for a ~4MB large kernel image, we have lc=3 and lp=0 for a
1565 total amount of (1846 + 768 << (3 + 0)) * 2 = ~41KB... that is
1566 a very small buffer.
1568 Use the lzmainfo tool to determinate the lc and lp values and
1569 then calculate the amount of needed dynamic memory (ensuring
1570 the appropriate CONFIG_SYS_MALLOC_LEN value).
1575 The address of PHY on MII bus.
1577 CONFIG_PHY_CLOCK_FREQ (ppc4xx)
1579 The clock frequency of the MII bus
1583 If this option is set, support for speed/duplex
1584 detection of gigabit PHY is included.
1586 CONFIG_PHY_RESET_DELAY
1588 Some PHY like Intel LXT971A need extra delay after
1589 reset before any MII register access is possible.
1590 For such PHY, set this option to the usec delay
1591 required. (minimum 300usec for LXT971A)
1593 CONFIG_PHY_CMD_DELAY (ppc4xx)
1595 Some PHY like Intel LXT971A need extra delay after
1596 command issued before MII status register can be read
1606 Define a default value for Ethernet address to use
1607 for the respective Ethernet interface, in case this
1608 is not determined automatically.
1613 Define a default value for the IP address to use for
1614 the default Ethernet interface, in case this is not
1615 determined through e.g. bootp.
1616 (Environment variable "ipaddr")
1618 - Server IP address:
1621 Defines a default value for the IP address of a TFTP
1622 server to contact when using the "tftboot" command.
1623 (Environment variable "serverip")
1625 CONFIG_KEEP_SERVERADDR
1627 Keeps the server's MAC address, in the env 'serveraddr'
1628 for passing to bootargs (like Linux's netconsole option)
1630 - Gateway IP address:
1633 Defines a default value for the IP address of the
1634 default router where packets to other networks are
1636 (Environment variable "gatewayip")
1641 Defines a default value for the subnet mask (or
1642 routing prefix) which is used to determine if an IP
1643 address belongs to the local subnet or needs to be
1644 forwarded through a router.
1645 (Environment variable "netmask")
1647 - Multicast TFTP Mode:
1650 Defines whether you want to support multicast TFTP as per
1651 rfc-2090; for example to work with atftp. Lets lots of targets
1652 tftp down the same boot image concurrently. Note: the Ethernet
1653 driver in use must provide a function: mcast() to join/leave a
1656 - BOOTP Recovery Mode:
1657 CONFIG_BOOTP_RANDOM_DELAY
1659 If you have many targets in a network that try to
1660 boot using BOOTP, you may want to avoid that all
1661 systems send out BOOTP requests at precisely the same
1662 moment (which would happen for instance at recovery
1663 from a power failure, when all systems will try to
1664 boot, thus flooding the BOOTP server. Defining
1665 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
1666 inserted before sending out BOOTP requests. The
1667 following delays are inserted then:
1669 1st BOOTP request: delay 0 ... 1 sec
1670 2nd BOOTP request: delay 0 ... 2 sec
1671 3rd BOOTP request: delay 0 ... 4 sec
1673 BOOTP requests: delay 0 ... 8 sec
1675 - DHCP Advanced Options:
1676 You can fine tune the DHCP functionality by defining
1677 CONFIG_BOOTP_* symbols:
1679 CONFIG_BOOTP_SUBNETMASK
1680 CONFIG_BOOTP_GATEWAY
1681 CONFIG_BOOTP_HOSTNAME
1682 CONFIG_BOOTP_NISDOMAIN
1683 CONFIG_BOOTP_BOOTPATH
1684 CONFIG_BOOTP_BOOTFILESIZE
1687 CONFIG_BOOTP_SEND_HOSTNAME
1688 CONFIG_BOOTP_NTPSERVER
1689 CONFIG_BOOTP_TIMEOFFSET
1690 CONFIG_BOOTP_VENDOREX
1691 CONFIG_BOOTP_MAY_FAIL
1693 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip
1694 environment variable, not the BOOTP server.
1696 CONFIG_BOOTP_MAY_FAIL - If the DHCP server is not found
1697 after the configured retry count, the call will fail
1698 instead of starting over. This can be used to fail over
1699 to Link-local IP address configuration if the DHCP server
1702 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS
1703 serverip from a DHCP server, it is possible that more
1704 than one DNS serverip is offered to the client.
1705 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS
1706 serverip will be stored in the additional environment
1707 variable "dnsip2". The first DNS serverip is always
1708 stored in the variable "dnsip", when CONFIG_BOOTP_DNS
1711 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable
1712 to do a dynamic update of a DNS server. To do this, they
1713 need the hostname of the DHCP requester.
1714 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content
1715 of the "hostname" environment variable is passed as
1716 option 12 to the DHCP server.
1718 CONFIG_BOOTP_DHCP_REQUEST_DELAY
1720 A 32bit value in microseconds for a delay between
1721 receiving a "DHCP Offer" and sending the "DHCP Request".
1722 This fixes a problem with certain DHCP servers that don't
1723 respond 100% of the time to a "DHCP request". E.g. On an
1724 AT91RM9200 processor running at 180MHz, this delay needed
1725 to be *at least* 15,000 usec before a Windows Server 2003
1726 DHCP server would reply 100% of the time. I recommend at
1727 least 50,000 usec to be safe. The alternative is to hope
1728 that one of the retries will be successful but note that
1729 the DHCP timeout and retry process takes a longer than
1732 - Link-local IP address negotiation:
1733 Negotiate with other link-local clients on the local network
1734 for an address that doesn't require explicit configuration.
1735 This is especially useful if a DHCP server cannot be guaranteed
1736 to exist in all environments that the device must operate.
1738 See doc/README.link-local for more information.
1741 CONFIG_CDP_DEVICE_ID
1743 The device id used in CDP trigger frames.
1745 CONFIG_CDP_DEVICE_ID_PREFIX
1747 A two character string which is prefixed to the MAC address
1752 A printf format string which contains the ascii name of
1753 the port. Normally is set to "eth%d" which sets
1754 eth0 for the first Ethernet, eth1 for the second etc.
1756 CONFIG_CDP_CAPABILITIES
1758 A 32bit integer which indicates the device capabilities;
1759 0x00000010 for a normal host which does not forwards.
1763 An ascii string containing the version of the software.
1767 An ascii string containing the name of the platform.
1771 A 32bit integer sent on the trigger.
1773 CONFIG_CDP_POWER_CONSUMPTION
1775 A 16bit integer containing the power consumption of the
1776 device in .1 of milliwatts.
1778 CONFIG_CDP_APPLIANCE_VLAN_TYPE
1780 A byte containing the id of the VLAN.
1782 - Status LED: CONFIG_STATUS_LED
1784 Several configurations allow to display the current
1785 status using a LED. For instance, the LED will blink
1786 fast while running U-Boot code, stop blinking as
1787 soon as a reply to a BOOTP request was received, and
1788 start blinking slow once the Linux kernel is running
1789 (supported by a status LED driver in the Linux
1790 kernel). Defining CONFIG_STATUS_LED enables this
1793 - CAN Support: CONFIG_CAN_DRIVER
1795 Defining CONFIG_CAN_DRIVER enables CAN driver support
1796 on those systems that support this (optional)
1797 feature, like the TQM8xxL modules.
1799 - I2C Support: CONFIG_HARD_I2C | CONFIG_SOFT_I2C
1801 These enable I2C serial bus commands. Defining either of
1802 (but not both of) CONFIG_HARD_I2C or CONFIG_SOFT_I2C will
1803 include the appropriate I2C driver for the selected CPU.
1805 This will allow you to use i2c commands at the u-boot
1806 command line (as long as you set CONFIG_CMD_I2C in
1807 CONFIG_COMMANDS) and communicate with i2c based realtime
1808 clock chips. See common/cmd_i2c.c for a description of the
1809 command line interface.
1811 CONFIG_HARD_I2C selects a hardware I2C controller.
1813 CONFIG_SOFT_I2C configures u-boot to use a software (aka
1814 bit-banging) driver instead of CPM or similar hardware
1817 There are several other quantities that must also be
1818 defined when you define CONFIG_HARD_I2C or CONFIG_SOFT_I2C.
1820 In both cases you will need to define CONFIG_SYS_I2C_SPEED
1821 to be the frequency (in Hz) at which you wish your i2c bus
1822 to run and CONFIG_SYS_I2C_SLAVE to be the address of this node (ie
1823 the CPU's i2c node address).
1825 Now, the u-boot i2c code for the mpc8xx
1826 (arch/powerpc/cpu/mpc8xx/i2c.c) sets the CPU up as a master node
1827 and so its address should therefore be cleared to 0 (See,
1828 eg, MPC823e User's Manual p.16-473). So, set
1829 CONFIG_SYS_I2C_SLAVE to 0.
1831 CONFIG_SYS_I2C_INIT_MPC5XXX
1833 When a board is reset during an i2c bus transfer
1834 chips might think that the current transfer is still
1835 in progress. Reset the slave devices by sending start
1836 commands until the slave device responds.
1838 That's all that's required for CONFIG_HARD_I2C.
1840 If you use the software i2c interface (CONFIG_SOFT_I2C)
1841 then the following macros need to be defined (examples are
1842 from include/configs/lwmon.h):
1846 (Optional). Any commands necessary to enable the I2C
1847 controller or configure ports.
1849 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
1853 (Only for MPC8260 CPU). The I/O port to use (the code
1854 assumes both bits are on the same port). Valid values
1855 are 0..3 for ports A..D.
1859 The code necessary to make the I2C data line active
1860 (driven). If the data line is open collector, this
1863 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
1867 The code necessary to make the I2C data line tri-stated
1868 (inactive). If the data line is open collector, this
1871 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
1875 Code that returns TRUE if the I2C data line is high,
1878 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
1882 If <bit> is TRUE, sets the I2C data line high. If it
1883 is FALSE, it clears it (low).
1885 eg: #define I2C_SDA(bit) \
1886 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
1887 else immr->im_cpm.cp_pbdat &= ~PB_SDA
1891 If <bit> is TRUE, sets the I2C clock line high. If it
1892 is FALSE, it clears it (low).
1894 eg: #define I2C_SCL(bit) \
1895 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
1896 else immr->im_cpm.cp_pbdat &= ~PB_SCL
1900 This delay is invoked four times per clock cycle so this
1901 controls the rate of data transfer. The data rate thus
1902 is 1 / (I2C_DELAY * 4). Often defined to be something
1905 #define I2C_DELAY udelay(2)
1907 CONFIG_SOFT_I2C_GPIO_SCL / CONFIG_SOFT_I2C_GPIO_SDA
1909 If your arch supports the generic GPIO framework (asm/gpio.h),
1910 then you may alternatively define the two GPIOs that are to be
1911 used as SCL / SDA. Any of the previous I2C_xxx macros will
1912 have GPIO-based defaults assigned to them as appropriate.
1914 You should define these to the GPIO value as given directly to
1915 the generic GPIO functions.
1917 CONFIG_SYS_I2C_INIT_BOARD
1919 When a board is reset during an i2c bus transfer
1920 chips might think that the current transfer is still
1921 in progress. On some boards it is possible to access
1922 the i2c SCLK line directly, either by using the
1923 processor pin as a GPIO or by having a second pin
1924 connected to the bus. If this option is defined a
1925 custom i2c_init_board() routine in boards/xxx/board.c
1926 is run early in the boot sequence.
1928 CONFIG_SYS_I2C_BOARD_LATE_INIT
1930 An alternative to CONFIG_SYS_I2C_INIT_BOARD. If this option is
1931 defined a custom i2c_board_late_init() routine in
1932 boards/xxx/board.c is run AFTER the operations in i2c_init()
1933 is completed. This callpoint can be used to unreset i2c bus
1934 using CPU i2c controller register accesses for CPUs whose i2c
1935 controller provide such a method. It is called at the end of
1936 i2c_init() to allow i2c_init operations to setup the i2c bus
1937 controller on the CPU (e.g. setting bus speed & slave address).
1939 CONFIG_I2CFAST (PPC405GP|PPC405EP only)
1941 This option enables configuration of bi_iic_fast[] flags
1942 in u-boot bd_info structure based on u-boot environment
1943 variable "i2cfast". (see also i2cfast)
1945 CONFIG_I2C_MULTI_BUS
1947 This option allows the use of multiple I2C buses, each of which
1948 must have a controller. At any point in time, only one bus is
1949 active. To switch to a different bus, use the 'i2c dev' command.
1950 Note that bus numbering is zero-based.
1952 CONFIG_SYS_I2C_NOPROBES
1954 This option specifies a list of I2C devices that will be skipped
1955 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS
1956 is set, specify a list of bus-device pairs. Otherwise, specify
1957 a 1D array of device addresses
1960 #undef CONFIG_I2C_MULTI_BUS
1961 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68}
1963 will skip addresses 0x50 and 0x68 on a board with one I2C bus
1965 #define CONFIG_I2C_MULTI_BUS
1966 #define CONFIG_SYS_I2C_MULTI_NOPROBES {{0,0x50},{0,0x68},{1,0x54}}
1968 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1
1970 CONFIG_SYS_SPD_BUS_NUM
1972 If defined, then this indicates the I2C bus number for DDR SPD.
1973 If not defined, then U-Boot assumes that SPD is on I2C bus 0.
1975 CONFIG_SYS_RTC_BUS_NUM
1977 If defined, then this indicates the I2C bus number for the RTC.
1978 If not defined, then U-Boot assumes that RTC is on I2C bus 0.
1980 CONFIG_SYS_DTT_BUS_NUM
1982 If defined, then this indicates the I2C bus number for the DTT.
1983 If not defined, then U-Boot assumes that DTT is on I2C bus 0.
1985 CONFIG_SYS_I2C_DTT_ADDR:
1987 If defined, specifies the I2C address of the DTT device.
1988 If not defined, then U-Boot uses predefined value for
1989 specified DTT device.
1993 Define this option if you want to use Freescale's I2C driver in
1994 drivers/i2c/fsl_i2c.c.
1998 Define this option if you have I2C devices reached over 1 .. n
1999 I2C Muxes like the pca9544a. This option addes a new I2C
2000 Command "i2c bus [muxtype:muxaddr:muxchannel]" which adds a
2001 new I2C Bus to the existing I2C Busses. If you select the
2002 new Bus with "i2c dev", u-bbot sends first the commandos for
2003 the muxes to activate this new "bus".
2005 CONFIG_I2C_MULTI_BUS must be also defined, to use this
2009 Adding a new I2C Bus reached over 2 pca9544a muxes
2010 The First mux with address 70 and channel 6
2011 The Second mux with address 71 and channel 4
2013 => i2c bus pca9544a:70:6:pca9544a:71:4
2015 Use the "i2c bus" command without parameter, to get a list
2016 of I2C Busses with muxes:
2019 Busses reached over muxes:
2021 reached over Mux(es):
2024 reached over Mux(es):
2029 If you now switch to the new I2C Bus 3 with "i2c dev 3"
2030 u-boot first sends the command to the mux@70 to enable
2031 channel 6, and then the command to the mux@71 to enable
2034 After that, you can use the "normal" i2c commands as
2035 usual to communicate with your I2C devices behind
2038 This option is actually implemented for the bitbanging
2039 algorithm in common/soft_i2c.c and for the Hardware I2C
2040 Bus on the MPC8260. But it should be not so difficult
2041 to add this option to other architectures.
2043 CONFIG_SOFT_I2C_READ_REPEATED_START
2045 defining this will force the i2c_read() function in
2046 the soft_i2c driver to perform an I2C repeated start
2047 between writing the address pointer and reading the
2048 data. If this define is omitted the default behaviour
2049 of doing a stop-start sequence will be used. Most I2C
2050 devices can use either method, but some require one or
2053 - SPI Support: CONFIG_SPI
2055 Enables SPI driver (so far only tested with
2056 SPI EEPROM, also an instance works with Crystal A/D and
2057 D/As on the SACSng board)
2061 Enables the driver for SPI controller on SuperH. Currently
2062 only SH7757 is supported.
2066 Enables extended (16-bit) SPI EEPROM addressing.
2067 (symmetrical to CONFIG_I2C_X)
2071 Enables a software (bit-bang) SPI driver rather than
2072 using hardware support. This is a general purpose
2073 driver that only requires three general I/O port pins
2074 (two outputs, one input) to function. If this is
2075 defined, the board configuration must define several
2076 SPI configuration items (port pins to use, etc). For
2077 an example, see include/configs/sacsng.h.
2081 Enables a hardware SPI driver for general-purpose reads
2082 and writes. As with CONFIG_SOFT_SPI, the board configuration
2083 must define a list of chip-select function pointers.
2084 Currently supported on some MPC8xxx processors. For an
2085 example, see include/configs/mpc8349emds.h.
2089 Enables the driver for the SPI controllers on i.MX and MXC
2090 SoCs. Currently i.MX31/35/51 are supported.
2092 - FPGA Support: CONFIG_FPGA
2094 Enables FPGA subsystem.
2096 CONFIG_FPGA_<vendor>
2098 Enables support for specific chip vendors.
2101 CONFIG_FPGA_<family>
2103 Enables support for FPGA family.
2104 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX)
2108 Specify the number of FPGA devices to support.
2110 CONFIG_SYS_FPGA_PROG_FEEDBACK
2112 Enable printing of hash marks during FPGA configuration.
2114 CONFIG_SYS_FPGA_CHECK_BUSY
2116 Enable checks on FPGA configuration interface busy
2117 status by the configuration function. This option
2118 will require a board or device specific function to
2123 If defined, a function that provides delays in the FPGA
2124 configuration driver.
2126 CONFIG_SYS_FPGA_CHECK_CTRLC
2127 Allow Control-C to interrupt FPGA configuration
2129 CONFIG_SYS_FPGA_CHECK_ERROR
2131 Check for configuration errors during FPGA bitfile
2132 loading. For example, abort during Virtex II
2133 configuration if the INIT_B line goes low (which
2134 indicated a CRC error).
2136 CONFIG_SYS_FPGA_WAIT_INIT
2138 Maximum time to wait for the INIT_B line to deassert
2139 after PROB_B has been deasserted during a Virtex II
2140 FPGA configuration sequence. The default time is 500
2143 CONFIG_SYS_FPGA_WAIT_BUSY
2145 Maximum time to wait for BUSY to deassert during
2146 Virtex II FPGA configuration. The default is 5 ms.
2148 CONFIG_SYS_FPGA_WAIT_CONFIG
2150 Time to wait after FPGA configuration. The default is
2153 - Configuration Management:
2156 If defined, this string will be added to the U-Boot
2157 version information (U_BOOT_VERSION)
2159 - Vendor Parameter Protection:
2161 U-Boot considers the values of the environment
2162 variables "serial#" (Board Serial Number) and
2163 "ethaddr" (Ethernet Address) to be parameters that
2164 are set once by the board vendor / manufacturer, and
2165 protects these variables from casual modification by
2166 the user. Once set, these variables are read-only,
2167 and write or delete attempts are rejected. You can
2168 change this behaviour:
2170 If CONFIG_ENV_OVERWRITE is #defined in your config
2171 file, the write protection for vendor parameters is
2172 completely disabled. Anybody can change or delete
2175 Alternatively, if you #define _both_ CONFIG_ETHADDR
2176 _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
2177 Ethernet address is installed in the environment,
2178 which can be changed exactly ONCE by the user. [The
2179 serial# is unaffected by this, i. e. it remains
2185 Define this variable to enable the reservation of
2186 "protected RAM", i. e. RAM which is not overwritten
2187 by U-Boot. Define CONFIG_PRAM to hold the number of
2188 kB you want to reserve for pRAM. You can overwrite
2189 this default value by defining an environment
2190 variable "pram" to the number of kB you want to
2191 reserve. Note that the board info structure will
2192 still show the full amount of RAM. If pRAM is
2193 reserved, a new environment variable "mem" will
2194 automatically be defined to hold the amount of
2195 remaining RAM in a form that can be passed as boot
2196 argument to Linux, for instance like that:
2198 setenv bootargs ... mem=\${mem}
2201 This way you can tell Linux not to use this memory,
2202 either, which results in a memory region that will
2203 not be affected by reboots.
2205 *WARNING* If your board configuration uses automatic
2206 detection of the RAM size, you must make sure that
2207 this memory test is non-destructive. So far, the
2208 following board configurations are known to be
2211 IVMS8, IVML24, SPD8xx, TQM8xxL,
2212 HERMES, IP860, RPXlite, LWMON,
2215 - Access to physical memory region (> 4GB)
2216 Some basic support is provided for operations on memory not
2217 normally accessible to U-Boot - e.g. some architectures
2218 support access to more than 4GB of memory on 32-bit
2219 machines using physical address extension or similar.
2220 Define CONFIG_PHYSMEM to access this basic support, which
2221 currently only supports clearing the memory.
2226 Define this variable to stop the system in case of a
2227 fatal error, so that you have to reset it manually.
2228 This is probably NOT a good idea for an embedded
2229 system where you want the system to reboot
2230 automatically as fast as possible, but it may be
2231 useful during development since you can try to debug
2232 the conditions that lead to the situation.
2234 CONFIG_NET_RETRY_COUNT
2236 This variable defines the number of retries for
2237 network operations like ARP, RARP, TFTP, or BOOTP
2238 before giving up the operation. If not defined, a
2239 default value of 5 is used.
2243 Timeout waiting for an ARP reply in milliseconds.
2247 Timeout in milliseconds used in NFS protocol.
2248 If you encounter "ERROR: Cannot umount" in nfs command,
2249 try longer timeout such as
2250 #define CONFIG_NFS_TIMEOUT 10000UL
2252 - Command Interpreter:
2253 CONFIG_AUTO_COMPLETE
2255 Enable auto completion of commands using TAB.
2257 Note that this feature has NOT been implemented yet
2258 for the "hush" shell.
2261 CONFIG_SYS_HUSH_PARSER
2263 Define this variable to enable the "hush" shell (from
2264 Busybox) as command line interpreter, thus enabling
2265 powerful command line syntax like
2266 if...then...else...fi conditionals or `&&' and '||'
2267 constructs ("shell scripts").
2269 If undefined, you get the old, much simpler behaviour
2270 with a somewhat smaller memory footprint.
2273 CONFIG_SYS_PROMPT_HUSH_PS2
2275 This defines the secondary prompt string, which is
2276 printed when the command interpreter needs more input
2277 to complete a command. Usually "> ".
2281 In the current implementation, the local variables
2282 space and global environment variables space are
2283 separated. Local variables are those you define by
2284 simply typing `name=value'. To access a local
2285 variable later on, you have write `$name' or
2286 `${name}'; to execute the contents of a variable
2287 directly type `$name' at the command prompt.
2289 Global environment variables are those you use
2290 setenv/printenv to work with. To run a command stored
2291 in such a variable, you need to use the run command,
2292 and you must not use the '$' sign to access them.
2294 To store commands and special characters in a
2295 variable, please use double quotation marks
2296 surrounding the whole text of the variable, instead
2297 of the backslashes before semicolons and special
2300 - Commandline Editing and History:
2301 CONFIG_CMDLINE_EDITING
2303 Enable editing and History functions for interactive
2304 commandline input operations
2306 - Default Environment:
2307 CONFIG_EXTRA_ENV_SETTINGS
2309 Define this to contain any number of null terminated
2310 strings (variable = value pairs) that will be part of
2311 the default environment compiled into the boot image.
2313 For example, place something like this in your
2314 board's config file:
2316 #define CONFIG_EXTRA_ENV_SETTINGS \
2320 Warning: This method is based on knowledge about the
2321 internal format how the environment is stored by the
2322 U-Boot code. This is NOT an official, exported
2323 interface! Although it is unlikely that this format
2324 will change soon, there is no guarantee either.
2325 You better know what you are doing here.
2327 Note: overly (ab)use of the default environment is
2328 discouraged. Make sure to check other ways to preset
2329 the environment like the "source" command or the
2332 CONFIG_ENV_VARS_UBOOT_CONFIG
2334 Define this in order to add variables describing the
2335 U-Boot build configuration to the default environment.
2336 These will be named arch, cpu, board, vendor, and soc.
2338 Enabling this option will cause the following to be defined:
2346 CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG
2348 Define this in order to add variables describing certain
2349 run-time determined information about the hardware to the
2350 environment. These will be named board_name, board_rev.
2352 - DataFlash Support:
2353 CONFIG_HAS_DATAFLASH
2355 Defining this option enables DataFlash features and
2356 allows to read/write in Dataflash via the standard
2359 - Serial Flash support
2362 Defining this option enables SPI flash commands
2363 'sf probe/read/write/erase/update'.
2365 Usage requires an initial 'probe' to define the serial
2366 flash parameters, followed by read/write/erase/update
2369 The following defaults may be provided by the platform
2370 to handle the common case when only a single serial
2371 flash is present on the system.
2373 CONFIG_SF_DEFAULT_BUS Bus identifier
2374 CONFIG_SF_DEFAULT_CS Chip-select
2375 CONFIG_SF_DEFAULT_MODE (see include/spi.h)
2376 CONFIG_SF_DEFAULT_SPEED in Hz
2378 - SystemACE Support:
2381 Adding this option adds support for Xilinx SystemACE
2382 chips attached via some sort of local bus. The address
2383 of the chip must also be defined in the
2384 CONFIG_SYS_SYSTEMACE_BASE macro. For example:
2386 #define CONFIG_SYSTEMACE
2387 #define CONFIG_SYS_SYSTEMACE_BASE 0xf0000000
2389 When SystemACE support is added, the "ace" device type
2390 becomes available to the fat commands, i.e. fatls.
2392 - TFTP Fixed UDP Port:
2395 If this is defined, the environment variable tftpsrcp
2396 is used to supply the TFTP UDP source port value.
2397 If tftpsrcp isn't defined, the normal pseudo-random port
2398 number generator is used.
2400 Also, the environment variable tftpdstp is used to supply
2401 the TFTP UDP destination port value. If tftpdstp isn't
2402 defined, the normal port 69 is used.
2404 The purpose for tftpsrcp is to allow a TFTP server to
2405 blindly start the TFTP transfer using the pre-configured
2406 target IP address and UDP port. This has the effect of
2407 "punching through" the (Windows XP) firewall, allowing
2408 the remainder of the TFTP transfer to proceed normally.
2409 A better solution is to properly configure the firewall,
2410 but sometimes that is not allowed.
2412 - Show boot progress:
2413 CONFIG_SHOW_BOOT_PROGRESS
2415 Defining this option allows to add some board-
2416 specific code (calling a user-provided function
2417 "show_boot_progress(int)") that enables you to show
2418 the system's boot progress on some display (for
2419 example, some LED's) on your board. At the moment,
2420 the following checkpoints are implemented:
2422 - Detailed boot stage timing
2424 Define this option to get detailed timing of each stage
2425 of the boot process.
2427 CONFIG_BOOTSTAGE_USER_COUNT
2428 This is the number of available user bootstage records.
2429 Each time you call bootstage_mark(BOOTSTAGE_ID_ALLOC, ...)
2430 a new ID will be allocated from this stash. If you exceed
2431 the limit, recording will stop.
2433 CONFIG_BOOTSTAGE_REPORT
2434 Define this to print a report before boot, similar to this:
2436 Timer summary in microseconds:
2439 3,575,678 3,575,678 board_init_f start
2440 3,575,695 17 arch_cpu_init A9
2441 3,575,777 82 arch_cpu_init done
2442 3,659,598 83,821 board_init_r start
2443 3,910,375 250,777 main_loop
2444 29,916,167 26,005,792 bootm_start
2445 30,361,327 445,160 start_kernel
2447 CONFIG_CMD_BOOTSTAGE
2448 Add a 'bootstage' command which supports printing a report
2449 and un/stashing of bootstage data.
2451 CONFIG_BOOTSTAGE_FDT
2452 Stash the bootstage information in the FDT. A root 'bootstage'
2453 node is created with each bootstage id as a child. Each child
2454 has a 'name' property and either 'mark' containing the
2455 mark time in microsecond, or 'accum' containing the
2456 accumulated time for that bootstage id in microseconds.
2461 name = "board_init_f";
2470 Code in the Linux kernel can find this in /proc/devicetree.
2472 Legacy uImage format:
2475 1 common/cmd_bootm.c before attempting to boot an image
2476 -1 common/cmd_bootm.c Image header has bad magic number
2477 2 common/cmd_bootm.c Image header has correct magic number
2478 -2 common/cmd_bootm.c Image header has bad checksum
2479 3 common/cmd_bootm.c Image header has correct checksum
2480 -3 common/cmd_bootm.c Image data has bad checksum
2481 4 common/cmd_bootm.c Image data has correct checksum
2482 -4 common/cmd_bootm.c Image is for unsupported architecture
2483 5 common/cmd_bootm.c Architecture check OK
2484 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi)
2485 6 common/cmd_bootm.c Image Type check OK
2486 -6 common/cmd_bootm.c gunzip uncompression error
2487 -7 common/cmd_bootm.c Unimplemented compression type
2488 7 common/cmd_bootm.c Uncompression OK
2489 8 common/cmd_bootm.c No uncompress/copy overwrite error
2490 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX)
2492 9 common/image.c Start initial ramdisk verification
2493 -10 common/image.c Ramdisk header has bad magic number
2494 -11 common/image.c Ramdisk header has bad checksum
2495 10 common/image.c Ramdisk header is OK
2496 -12 common/image.c Ramdisk data has bad checksum
2497 11 common/image.c Ramdisk data has correct checksum
2498 12 common/image.c Ramdisk verification complete, start loading
2499 -13 common/image.c Wrong Image Type (not PPC Linux ramdisk)
2500 13 common/image.c Start multifile image verification
2501 14 common/image.c No initial ramdisk, no multifile, continue.
2503 15 arch/<arch>/lib/bootm.c All preparation done, transferring control to OS
2505 -30 arch/powerpc/lib/board.c Fatal error, hang the system
2506 -31 post/post.c POST test failed, detected by post_output_backlog()
2507 -32 post/post.c POST test failed, detected by post_run_single()
2509 34 common/cmd_doc.c before loading a Image from a DOC device
2510 -35 common/cmd_doc.c Bad usage of "doc" command
2511 35 common/cmd_doc.c correct usage of "doc" command
2512 -36 common/cmd_doc.c No boot device
2513 36 common/cmd_doc.c correct boot device
2514 -37 common/cmd_doc.c Unknown Chip ID on boot device
2515 37 common/cmd_doc.c correct chip ID found, device available
2516 -38 common/cmd_doc.c Read Error on boot device
2517 38 common/cmd_doc.c reading Image header from DOC device OK
2518 -39 common/cmd_doc.c Image header has bad magic number
2519 39 common/cmd_doc.c Image header has correct magic number
2520 -40 common/cmd_doc.c Error reading Image from DOC device
2521 40 common/cmd_doc.c Image header has correct magic number
2522 41 common/cmd_ide.c before loading a Image from a IDE device
2523 -42 common/cmd_ide.c Bad usage of "ide" command
2524 42 common/cmd_ide.c correct usage of "ide" command
2525 -43 common/cmd_ide.c No boot device
2526 43 common/cmd_ide.c boot device found
2527 -44 common/cmd_ide.c Device not available
2528 44 common/cmd_ide.c Device available
2529 -45 common/cmd_ide.c wrong partition selected
2530 45 common/cmd_ide.c partition selected
2531 -46 common/cmd_ide.c Unknown partition table
2532 46 common/cmd_ide.c valid partition table found
2533 -47 common/cmd_ide.c Invalid partition type
2534 47 common/cmd_ide.c correct partition type
2535 -48 common/cmd_ide.c Error reading Image Header on boot device
2536 48 common/cmd_ide.c reading Image Header from IDE device OK
2537 -49 common/cmd_ide.c Image header has bad magic number
2538 49 common/cmd_ide.c Image header has correct magic number
2539 -50 common/cmd_ide.c Image header has bad checksum
2540 50 common/cmd_ide.c Image header has correct checksum
2541 -51 common/cmd_ide.c Error reading Image from IDE device
2542 51 common/cmd_ide.c reading Image from IDE device OK
2543 52 common/cmd_nand.c before loading a Image from a NAND device
2544 -53 common/cmd_nand.c Bad usage of "nand" command
2545 53 common/cmd_nand.c correct usage of "nand" command
2546 -54 common/cmd_nand.c No boot device
2547 54 common/cmd_nand.c boot device found
2548 -55 common/cmd_nand.c Unknown Chip ID on boot device
2549 55 common/cmd_nand.c correct chip ID found, device available
2550 -56 common/cmd_nand.c Error reading Image Header on boot device
2551 56 common/cmd_nand.c reading Image Header from NAND device OK
2552 -57 common/cmd_nand.c Image header has bad magic number
2553 57 common/cmd_nand.c Image header has correct magic number
2554 -58 common/cmd_nand.c Error reading Image from NAND device
2555 58 common/cmd_nand.c reading Image from NAND device OK
2557 -60 common/env_common.c Environment has a bad CRC, using default
2559 64 net/eth.c starting with Ethernet configuration.
2560 -64 net/eth.c no Ethernet found.
2561 65 net/eth.c Ethernet found.
2563 -80 common/cmd_net.c usage wrong
2564 80 common/cmd_net.c before calling NetLoop()
2565 -81 common/cmd_net.c some error in NetLoop() occurred
2566 81 common/cmd_net.c NetLoop() back without error
2567 -82 common/cmd_net.c size == 0 (File with size 0 loaded)
2568 82 common/cmd_net.c trying automatic boot
2569 83 common/cmd_net.c running "source" command
2570 -83 common/cmd_net.c some error in automatic boot or "source" command
2571 84 common/cmd_net.c end without errors
2576 100 common/cmd_bootm.c Kernel FIT Image has correct format
2577 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format
2578 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration
2579 -101 common/cmd_bootm.c Can't get configuration for kernel subimage
2580 102 common/cmd_bootm.c Kernel unit name specified
2581 -103 common/cmd_bootm.c Can't get kernel subimage node offset
2582 103 common/cmd_bootm.c Found configuration node
2583 104 common/cmd_bootm.c Got kernel subimage node offset
2584 -104 common/cmd_bootm.c Kernel subimage hash verification failed
2585 105 common/cmd_bootm.c Kernel subimage hash verification OK
2586 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture
2587 106 common/cmd_bootm.c Architecture check OK
2588 -106 common/cmd_bootm.c Kernel subimage has wrong type
2589 107 common/cmd_bootm.c Kernel subimage type OK
2590 -107 common/cmd_bootm.c Can't get kernel subimage data/size
2591 108 common/cmd_bootm.c Got kernel subimage data/size
2592 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT)
2593 -109 common/cmd_bootm.c Can't get kernel subimage type
2594 -110 common/cmd_bootm.c Can't get kernel subimage comp
2595 -111 common/cmd_bootm.c Can't get kernel subimage os
2596 -112 common/cmd_bootm.c Can't get kernel subimage load address
2597 -113 common/cmd_bootm.c Image uncompress/copy overwrite error
2599 120 common/image.c Start initial ramdisk verification
2600 -120 common/image.c Ramdisk FIT image has incorrect format
2601 121 common/image.c Ramdisk FIT image has correct format
2602 122 common/image.c No ramdisk subimage unit name, using configuration
2603 -122 common/image.c Can't get configuration for ramdisk subimage
2604 123 common/image.c Ramdisk unit name specified
2605 -124 common/image.c Can't get ramdisk subimage node offset
2606 125 common/image.c Got ramdisk subimage node offset
2607 -125 common/image.c Ramdisk subimage hash verification failed
2608 126 common/image.c Ramdisk subimage hash verification OK
2609 -126 common/image.c Ramdisk subimage for unsupported architecture
2610 127 common/image.c Architecture check OK
2611 -127 common/image.c Can't get ramdisk subimage data/size
2612 128 common/image.c Got ramdisk subimage data/size
2613 129 common/image.c Can't get ramdisk load address
2614 -129 common/image.c Got ramdisk load address
2616 -130 common/cmd_doc.c Incorrect FIT image format
2617 131 common/cmd_doc.c FIT image format OK
2619 -140 common/cmd_ide.c Incorrect FIT image format
2620 141 common/cmd_ide.c FIT image format OK
2622 -150 common/cmd_nand.c Incorrect FIT image format
2623 151 common/cmd_nand.c FIT image format OK
2625 - FIT image support:
2627 Enable support for the FIT uImage format.
2629 CONFIG_FIT_BEST_MATCH
2630 When no configuration is explicitly selected, default to the
2631 one whose fdt's compatibility field best matches that of
2632 U-Boot itself. A match is considered "best" if it matches the
2633 most specific compatibility entry of U-Boot's fdt's root node.
2634 The order of entries in the configuration's fdt is ignored.
2636 - Standalone program support:
2637 CONFIG_STANDALONE_LOAD_ADDR
2639 This option defines a board specific value for the
2640 address where standalone program gets loaded, thus
2641 overwriting the architecture dependent default
2644 - Frame Buffer Address:
2647 Define CONFIG_FB_ADDR if you want to use specific
2648 address for frame buffer.
2649 Then system will reserve the frame buffer address to
2650 defined address instead of lcd_setmem (this function
2651 grabs the memory for frame buffer by panel's size).
2653 Please see board_init_f function.
2655 - Automatic software updates via TFTP server
2657 CONFIG_UPDATE_TFTP_CNT_MAX
2658 CONFIG_UPDATE_TFTP_MSEC_MAX
2660 These options enable and control the auto-update feature;
2661 for a more detailed description refer to doc/README.update.
2663 - MTD Support (mtdparts command, UBI support)
2666 Adds the MTD device infrastructure from the Linux kernel.
2667 Needed for mtdparts command support.
2669 CONFIG_MTD_PARTITIONS
2671 Adds the MTD partitioning infrastructure from the Linux
2672 kernel. Needed for UBI support.
2676 Enable building of SPL globally.
2679 LDSCRIPT for linking the SPL binary.
2682 Maximum binary size (text, data and rodata) of the SPL binary.
2684 CONFIG_SPL_TEXT_BASE
2685 TEXT_BASE for linking the SPL binary.
2687 CONFIG_SPL_RELOC_TEXT_BASE
2688 Address to relocate to. If unspecified, this is equal to
2689 CONFIG_SPL_TEXT_BASE (i.e. no relocation is done).
2691 CONFIG_SPL_BSS_START_ADDR
2692 Link address for the BSS within the SPL binary.
2694 CONFIG_SPL_BSS_MAX_SIZE
2695 Maximum binary size of the BSS section of the SPL binary.
2698 Adress of the start of the stack SPL will use
2700 CONFIG_SPL_RELOC_STACK
2701 Adress of the start of the stack SPL will use after
2702 relocation. If unspecified, this is equal to
2705 CONFIG_SYS_SPL_MALLOC_START
2706 Starting address of the malloc pool used in SPL.
2708 CONFIG_SYS_SPL_MALLOC_SIZE
2709 The size of the malloc pool used in SPL.
2711 CONFIG_SPL_FRAMEWORK
2712 Enable the SPL framework under common/. This framework
2713 supports MMC, NAND and YMODEM loading of U-Boot and NAND
2714 NAND loading of the Linux Kernel.
2716 CONFIG_SPL_DISPLAY_PRINT
2717 For ARM, enable an optional function to print more information
2718 about the running system.
2720 CONFIG_SPL_INIT_MINIMAL
2721 Arch init code should be built for a very small image
2723 CONFIG_SPL_LIBCOMMON_SUPPORT
2724 Support for common/libcommon.o in SPL binary
2726 CONFIG_SPL_LIBDISK_SUPPORT
2727 Support for disk/libdisk.o in SPL binary
2729 CONFIG_SPL_I2C_SUPPORT
2730 Support for drivers/i2c/libi2c.o in SPL binary
2732 CONFIG_SPL_GPIO_SUPPORT
2733 Support for drivers/gpio/libgpio.o in SPL binary
2735 CONFIG_SPL_MMC_SUPPORT
2736 Support for drivers/mmc/libmmc.o in SPL binary
2738 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_SECTOR,
2739 CONFIG_SYS_U_BOOT_MAX_SIZE_SECTORS,
2740 CONFIG_SYS_MMC_SD_FAT_BOOT_PARTITION
2741 Address, size and partition on the MMC to load U-Boot from
2742 when the MMC is being used in raw mode.
2744 CONFIG_SPL_FAT_SUPPORT
2745 Support for fs/fat/libfat.o in SPL binary
2747 CONFIG_SPL_FAT_LOAD_PAYLOAD_NAME
2748 Filename to read to load U-Boot when reading from FAT
2750 CONFIG_SPL_NAND_BASE
2751 Include nand_base.c in the SPL. Requires
2752 CONFIG_SPL_NAND_DRIVERS.
2754 CONFIG_SPL_NAND_DRIVERS
2755 SPL uses normal NAND drivers, not minimal drivers.
2758 Include standard software ECC in the SPL
2760 CONFIG_SPL_NAND_SIMPLE
2761 Support for NAND boot using simple NAND drivers that
2762 expose the cmd_ctrl() interface.
2764 CONFIG_SYS_NAND_5_ADDR_CYCLE, CONFIG_SYS_NAND_PAGE_COUNT,
2765 CONFIG_SYS_NAND_PAGE_SIZE, CONFIG_SYS_NAND_OOBSIZE,
2766 CONFIG_SYS_NAND_BLOCK_SIZE, CONFIG_SYS_NAND_BAD_BLOCK_POS,
2767 CONFIG_SYS_NAND_ECCPOS, CONFIG_SYS_NAND_ECCSIZE,
2768 CONFIG_SYS_NAND_ECCBYTES
2769 Defines the size and behavior of the NAND that SPL uses
2772 CONFIG_SYS_NAND_U_BOOT_OFFS
2773 Location in NAND to read U-Boot from
2775 CONFIG_SYS_NAND_U_BOOT_DST
2776 Location in memory to load U-Boot to
2778 CONFIG_SYS_NAND_U_BOOT_SIZE
2779 Size of image to load
2781 CONFIG_SYS_NAND_U_BOOT_START
2782 Entry point in loaded image to jump to
2784 CONFIG_SYS_NAND_HW_ECC_OOBFIRST
2785 Define this if you need to first read the OOB and then the
2786 data. This is used for example on davinci plattforms.
2788 CONFIG_SPL_OMAP3_ID_NAND
2789 Support for an OMAP3-specific set of functions to return the
2790 ID and MFR of the first attached NAND chip, if present.
2792 CONFIG_SPL_SERIAL_SUPPORT
2793 Support for drivers/serial/libserial.o in SPL binary
2795 CONFIG_SPL_SPI_FLASH_SUPPORT
2796 Support for drivers/mtd/spi/libspi_flash.o in SPL binary
2798 CONFIG_SPL_SPI_SUPPORT
2799 Support for drivers/spi/libspi.o in SPL binary
2801 CONFIG_SPL_RAM_DEVICE
2802 Support for running image already present in ram, in SPL binary
2804 CONFIG_SPL_LIBGENERIC_SUPPORT
2805 Support for lib/libgeneric.o in SPL binary
2808 Final target image containing SPL and payload. Some SPLs
2809 use an arch-specific makefile fragment instead, for
2810 example if more than one image needs to be produced.
2815 [so far only for SMDK2400 boards]
2817 - Modem support enable:
2818 CONFIG_MODEM_SUPPORT
2820 - RTS/CTS Flow control enable:
2823 - Modem debug support:
2824 CONFIG_MODEM_SUPPORT_DEBUG
2826 Enables debugging stuff (char screen[1024], dbg())
2827 for modem support. Useful only with BDI2000.
2829 - Interrupt support (PPC):
2831 There are common interrupt_init() and timer_interrupt()
2832 for all PPC archs. interrupt_init() calls interrupt_init_cpu()
2833 for CPU specific initialization. interrupt_init_cpu()
2834 should set decrementer_count to appropriate value. If
2835 CPU resets decrementer automatically after interrupt
2836 (ppc4xx) it should set decrementer_count to zero.
2837 timer_interrupt() calls timer_interrupt_cpu() for CPU
2838 specific handling. If board has watchdog / status_led
2839 / other_activity_monitor it works automatically from
2840 general timer_interrupt().
2844 In the target system modem support is enabled when a
2845 specific key (key combination) is pressed during
2846 power-on. Otherwise U-Boot will boot normally
2847 (autoboot). The key_pressed() function is called from
2848 board_init(). Currently key_pressed() is a dummy
2849 function, returning 1 and thus enabling modem
2852 If there are no modem init strings in the
2853 environment, U-Boot proceed to autoboot; the
2854 previous output (banner, info printfs) will be
2857 See also: doc/README.Modem
2859 Board initialization settings:
2860 ------------------------------
2862 During Initialization u-boot calls a number of board specific functions
2863 to allow the preparation of board specific prerequisites, e.g. pin setup
2864 before drivers are initialized. To enable these callbacks the
2865 following configuration macros have to be defined. Currently this is
2866 architecture specific, so please check arch/your_architecture/lib/board.c
2867 typically in board_init_f() and board_init_r().
2869 - CONFIG_BOARD_EARLY_INIT_F: Call board_early_init_f()
2870 - CONFIG_BOARD_EARLY_INIT_R: Call board_early_init_r()
2871 - CONFIG_BOARD_LATE_INIT: Call board_late_init()
2872 - CONFIG_BOARD_POSTCLK_INIT: Call board_postclk_init()
2874 Configuration Settings:
2875 -----------------------
2877 - CONFIG_SYS_LONGHELP: Defined when you want long help messages included;
2878 undefine this when you're short of memory.
2880 - CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default
2881 width of the commands listed in the 'help' command output.
2883 - CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to
2884 prompt for user input.
2886 - CONFIG_SYS_CBSIZE: Buffer size for input from the Console
2888 - CONFIG_SYS_PBSIZE: Buffer size for Console output
2890 - CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands
2892 - CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to
2893 the application (usually a Linux kernel) when it is
2896 - CONFIG_SYS_BAUDRATE_TABLE:
2897 List of legal baudrate settings for this board.
2899 - CONFIG_SYS_CONSOLE_INFO_QUIET
2900 Suppress display of console information at boot.
2902 - CONFIG_SYS_CONSOLE_IS_IN_ENV
2903 If the board specific function
2904 extern int overwrite_console (void);
2905 returns 1, the stdin, stderr and stdout are switched to the
2906 serial port, else the settings in the environment are used.
2908 - CONFIG_SYS_CONSOLE_OVERWRITE_ROUTINE
2909 Enable the call to overwrite_console().
2911 - CONFIG_SYS_CONSOLE_ENV_OVERWRITE
2912 Enable overwrite of previous console environment settings.
2914 - CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END:
2915 Begin and End addresses of the area used by the
2918 - CONFIG_SYS_ALT_MEMTEST:
2919 Enable an alternate, more extensive memory test.
2921 - CONFIG_SYS_MEMTEST_SCRATCH:
2922 Scratch address used by the alternate memory test
2923 You only need to set this if address zero isn't writeable
2925 - CONFIG_SYS_MEM_TOP_HIDE (PPC only):
2926 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header,
2927 this specified memory area will get subtracted from the top
2928 (end) of RAM and won't get "touched" at all by U-Boot. By
2929 fixing up gd->ram_size the Linux kernel should gets passed
2930 the now "corrected" memory size and won't touch it either.
2931 This should work for arch/ppc and arch/powerpc. Only Linux
2932 board ports in arch/powerpc with bootwrapper support that
2933 recalculate the memory size from the SDRAM controller setup
2934 will have to get fixed in Linux additionally.
2936 This option can be used as a workaround for the 440EPx/GRx
2937 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't
2940 WARNING: Please make sure that this value is a multiple of
2941 the Linux page size (normally 4k). If this is not the case,
2942 then the end address of the Linux memory will be located at a
2943 non page size aligned address and this could cause major
2946 - CONFIG_SYS_TFTP_LOADADDR:
2947 Default load address for network file downloads
2949 - CONFIG_SYS_LOADS_BAUD_CHANGE:
2950 Enable temporary baudrate change while serial download
2952 - CONFIG_SYS_SDRAM_BASE:
2953 Physical start address of SDRAM. _Must_ be 0 here.
2955 - CONFIG_SYS_MBIO_BASE:
2956 Physical start address of Motherboard I/O (if using a
2959 - CONFIG_SYS_FLASH_BASE:
2960 Physical start address of Flash memory.
2962 - CONFIG_SYS_MONITOR_BASE:
2963 Physical start address of boot monitor code (set by
2964 make config files to be same as the text base address
2965 (CONFIG_SYS_TEXT_BASE) used when linking) - same as
2966 CONFIG_SYS_FLASH_BASE when booting from flash.
2968 - CONFIG_SYS_MONITOR_LEN:
2969 Size of memory reserved for monitor code, used to
2970 determine _at_compile_time_ (!) if the environment is
2971 embedded within the U-Boot image, or in a separate
2974 - CONFIG_SYS_MALLOC_LEN:
2975 Size of DRAM reserved for malloc() use.
2977 - CONFIG_SYS_BOOTM_LEN:
2978 Normally compressed uImages are limited to an
2979 uncompressed size of 8 MBytes. If this is not enough,
2980 you can define CONFIG_SYS_BOOTM_LEN in your board config file
2981 to adjust this setting to your needs.
2983 - CONFIG_SYS_BOOTMAPSZ:
2984 Maximum size of memory mapped by the startup code of
2985 the Linux kernel; all data that must be processed by
2986 the Linux kernel (bd_info, boot arguments, FDT blob if
2987 used) must be put below this limit, unless "bootm_low"
2988 enviroment variable is defined and non-zero. In such case
2989 all data for the Linux kernel must be between "bootm_low"
2990 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ. The environment
2991 variable "bootm_mapsize" will override the value of
2992 CONFIG_SYS_BOOTMAPSZ. If CONFIG_SYS_BOOTMAPSZ is undefined,
2993 then the value in "bootm_size" will be used instead.
2995 - CONFIG_SYS_BOOT_RAMDISK_HIGH:
2996 Enable initrd_high functionality. If defined then the
2997 initrd_high feature is enabled and the bootm ramdisk subcommand
3000 - CONFIG_SYS_BOOT_GET_CMDLINE:
3001 Enables allocating and saving kernel cmdline in space between
3002 "bootm_low" and "bootm_low" + BOOTMAPSZ.
3004 - CONFIG_SYS_BOOT_GET_KBD:
3005 Enables allocating and saving a kernel copy of the bd_info in
3006 space between "bootm_low" and "bootm_low" + BOOTMAPSZ.
3008 - CONFIG_SYS_MAX_FLASH_BANKS:
3009 Max number of Flash memory banks
3011 - CONFIG_SYS_MAX_FLASH_SECT:
3012 Max number of sectors on a Flash chip
3014 - CONFIG_SYS_FLASH_ERASE_TOUT:
3015 Timeout for Flash erase operations (in ms)
3017 - CONFIG_SYS_FLASH_WRITE_TOUT:
3018 Timeout for Flash write operations (in ms)
3020 - CONFIG_SYS_FLASH_LOCK_TOUT
3021 Timeout for Flash set sector lock bit operation (in ms)
3023 - CONFIG_SYS_FLASH_UNLOCK_TOUT
3024 Timeout for Flash clear lock bits operation (in ms)
3026 - CONFIG_SYS_FLASH_PROTECTION
3027 If defined, hardware flash sectors protection is used
3028 instead of U-Boot software protection.
3030 - CONFIG_SYS_DIRECT_FLASH_TFTP:
3032 Enable TFTP transfers directly to flash memory;
3033 without this option such a download has to be
3034 performed in two steps: (1) download to RAM, and (2)
3035 copy from RAM to flash.
3037 The two-step approach is usually more reliable, since
3038 you can check if the download worked before you erase
3039 the flash, but in some situations (when system RAM is
3040 too limited to allow for a temporary copy of the
3041 downloaded image) this option may be very useful.
3043 - CONFIG_SYS_FLASH_CFI:
3044 Define if the flash driver uses extra elements in the
3045 common flash structure for storing flash geometry.
3047 - CONFIG_FLASH_CFI_DRIVER
3048 This option also enables the building of the cfi_flash driver
3049 in the drivers directory
3051 - CONFIG_FLASH_CFI_MTD
3052 This option enables the building of the cfi_mtd driver
3053 in the drivers directory. The driver exports CFI flash
3056 - CONFIG_SYS_FLASH_USE_BUFFER_WRITE
3057 Use buffered writes to flash.
3059 - CONFIG_FLASH_SPANSION_S29WS_N
3060 s29ws-n MirrorBit flash has non-standard addresses for buffered
3063 - CONFIG_SYS_FLASH_QUIET_TEST
3064 If this option is defined, the common CFI flash doesn't
3065 print it's warning upon not recognized FLASH banks. This
3066 is useful, if some of the configured banks are only
3067 optionally available.
3069 - CONFIG_FLASH_SHOW_PROGRESS
3070 If defined (must be an integer), print out countdown
3071 digits and dots. Recommended value: 45 (9..1) for 80
3072 column displays, 15 (3..1) for 40 column displays.
3074 - CONFIG_SYS_RX_ETH_BUFFER:
3075 Defines the number of Ethernet receive buffers. On some
3076 Ethernet controllers it is recommended to set this value
3077 to 8 or even higher (EEPRO100 or 405 EMAC), since all
3078 buffers can be full shortly after enabling the interface
3079 on high Ethernet traffic.
3080 Defaults to 4 if not defined.
3082 - CONFIG_ENV_MAX_ENTRIES
3084 Maximum number of entries in the hash table that is used
3085 internally to store the environment settings. The default
3086 setting is supposed to be generous and should work in most
3087 cases. This setting can be used to tune behaviour; see
3088 lib/hashtable.c for details.
3090 The following definitions that deal with the placement and management
3091 of environment data (variable area); in general, we support the
3092 following configurations:
3094 - CONFIG_BUILD_ENVCRC:
3096 Builds up envcrc with the target environment so that external utils
3097 may easily extract it and embed it in final U-Boot images.
3099 - CONFIG_ENV_IS_IN_FLASH:
3101 Define this if the environment is in flash memory.
3103 a) The environment occupies one whole flash sector, which is
3104 "embedded" in the text segment with the U-Boot code. This
3105 happens usually with "bottom boot sector" or "top boot
3106 sector" type flash chips, which have several smaller
3107 sectors at the start or the end. For instance, such a
3108 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In
3109 such a case you would place the environment in one of the
3110 4 kB sectors - with U-Boot code before and after it. With
3111 "top boot sector" type flash chips, you would put the
3112 environment in one of the last sectors, leaving a gap
3113 between U-Boot and the environment.
3115 - CONFIG_ENV_OFFSET:
3117 Offset of environment data (variable area) to the
3118 beginning of flash memory; for instance, with bottom boot
3119 type flash chips the second sector can be used: the offset
3120 for this sector is given here.
3122 CONFIG_ENV_OFFSET is used relative to CONFIG_SYS_FLASH_BASE.
3126 This is just another way to specify the start address of
3127 the flash sector containing the environment (instead of
3130 - CONFIG_ENV_SECT_SIZE:
3132 Size of the sector containing the environment.
3135 b) Sometimes flash chips have few, equal sized, BIG sectors.
3136 In such a case you don't want to spend a whole sector for
3141 If you use this in combination with CONFIG_ENV_IS_IN_FLASH
3142 and CONFIG_ENV_SECT_SIZE, you can specify to use only a part
3143 of this flash sector for the environment. This saves
3144 memory for the RAM copy of the environment.
3146 It may also save flash memory if you decide to use this
3147 when your environment is "embedded" within U-Boot code,
3148 since then the remainder of the flash sector could be used
3149 for U-Boot code. It should be pointed out that this is
3150 STRONGLY DISCOURAGED from a robustness point of view:
3151 updating the environment in flash makes it always
3152 necessary to erase the WHOLE sector. If something goes
3153 wrong before the contents has been restored from a copy in
3154 RAM, your target system will be dead.
3156 - CONFIG_ENV_ADDR_REDUND
3157 CONFIG_ENV_SIZE_REDUND
3159 These settings describe a second storage area used to hold
3160 a redundant copy of the environment data, so that there is
3161 a valid backup copy in case there is a power failure during
3162 a "saveenv" operation.
3164 BE CAREFUL! Any changes to the flash layout, and some changes to the
3165 source code will make it necessary to adapt <board>/u-boot.lds*
3169 - CONFIG_ENV_IS_IN_NVRAM:
3171 Define this if you have some non-volatile memory device
3172 (NVRAM, battery buffered SRAM) which you want to use for the
3178 These two #defines are used to determine the memory area you
3179 want to use for environment. It is assumed that this memory
3180 can just be read and written to, without any special
3183 BE CAREFUL! The first access to the environment happens quite early
3184 in U-Boot initalization (when we try to get the setting of for the
3185 console baudrate). You *MUST* have mapped your NVRAM area then, or
3188 Please note that even with NVRAM we still use a copy of the
3189 environment in RAM: we could work on NVRAM directly, but we want to
3190 keep settings there always unmodified except somebody uses "saveenv"
3191 to save the current settings.
3194 - CONFIG_ENV_IS_IN_EEPROM:
3196 Use this if you have an EEPROM or similar serial access
3197 device and a driver for it.
3199 - CONFIG_ENV_OFFSET:
3202 These two #defines specify the offset and size of the
3203 environment area within the total memory of your EEPROM.
3205 - CONFIG_SYS_I2C_EEPROM_ADDR:
3206 If defined, specified the chip address of the EEPROM device.
3207 The default address is zero.
3209 - CONFIG_SYS_EEPROM_PAGE_WRITE_BITS:
3210 If defined, the number of bits used to address bytes in a
3211 single page in the EEPROM device. A 64 byte page, for example
3212 would require six bits.
3214 - CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS:
3215 If defined, the number of milliseconds to delay between
3216 page writes. The default is zero milliseconds.
3218 - CONFIG_SYS_I2C_EEPROM_ADDR_LEN:
3219 The length in bytes of the EEPROM memory array address. Note
3220 that this is NOT the chip address length!
3222 - CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW:
3223 EEPROM chips that implement "address overflow" are ones
3224 like Catalyst 24WC04/08/16 which has 9/10/11 bits of
3225 address and the extra bits end up in the "chip address" bit
3226 slots. This makes a 24WC08 (1Kbyte) chip look like four 256
3229 Note that we consider the length of the address field to
3230 still be one byte because the extra address bits are hidden
3231 in the chip address.
3233 - CONFIG_SYS_EEPROM_SIZE:
3234 The size in bytes of the EEPROM device.
3236 - CONFIG_ENV_EEPROM_IS_ON_I2C
3237 define this, if you have I2C and SPI activated, and your
3238 EEPROM, which holds the environment, is on the I2C bus.
3240 - CONFIG_I2C_ENV_EEPROM_BUS
3241 if you have an Environment on an EEPROM reached over
3242 I2C muxes, you can define here, how to reach this
3243 EEPROM. For example:
3245 #define CONFIG_I2C_ENV_EEPROM_BUS "pca9547:70:d\0"
3247 EEPROM which holds the environment, is reached over
3248 a pca9547 i2c mux with address 0x70, channel 3.
3250 - CONFIG_ENV_IS_IN_DATAFLASH:
3252 Define this if you have a DataFlash memory device which you
3253 want to use for the environment.
3255 - CONFIG_ENV_OFFSET:
3259 These three #defines specify the offset and size of the
3260 environment area within the total memory of your DataFlash placed
3261 at the specified address.
3263 - CONFIG_ENV_IS_IN_REMOTE:
3265 Define this if you have a remote memory space which you
3266 want to use for the local device's environment.
3271 These two #defines specify the address and size of the
3272 environment area within the remote memory space. The
3273 local device can get the environment from remote memory
3274 space by SRIO or PCIE links.
3276 BE CAREFUL! For some special cases, the local device can not use
3277 "saveenv" command. For example, the local device will get the
3278 environment stored in a remote NOR flash by SRIO or PCIE link,
3279 but it can not erase, write this NOR flash by SRIO or PCIE interface.
3281 - CONFIG_ENV_IS_IN_NAND:
3283 Define this if you have a NAND device which you want to use
3284 for the environment.
3286 - CONFIG_ENV_OFFSET:
3289 These two #defines specify the offset and size of the environment
3290 area within the first NAND device. CONFIG_ENV_OFFSET must be
3291 aligned to an erase block boundary.
3293 - CONFIG_ENV_OFFSET_REDUND (optional):
3295 This setting describes a second storage area of CONFIG_ENV_SIZE
3296 size used to hold a redundant copy of the environment data, so
3297 that there is a valid backup copy in case there is a power failure
3298 during a "saveenv" operation. CONFIG_ENV_OFFSET_RENDUND must be
3299 aligned to an erase block boundary.
3301 - CONFIG_ENV_RANGE (optional):
3303 Specifies the length of the region in which the environment
3304 can be written. This should be a multiple of the NAND device's
3305 block size. Specifying a range with more erase blocks than
3306 are needed to hold CONFIG_ENV_SIZE allows bad blocks within
3307 the range to be avoided.
3309 - CONFIG_ENV_OFFSET_OOB (optional):
3311 Enables support for dynamically retrieving the offset of the
3312 environment from block zero's out-of-band data. The
3313 "nand env.oob" command can be used to record this offset.
3314 Currently, CONFIG_ENV_OFFSET_REDUND is not supported when
3315 using CONFIG_ENV_OFFSET_OOB.
3317 - CONFIG_NAND_ENV_DST
3319 Defines address in RAM to which the nand_spl code should copy the
3320 environment. If redundant environment is used, it will be copied to
3321 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE.
3323 - CONFIG_SYS_SPI_INIT_OFFSET
3325 Defines offset to the initial SPI buffer area in DPRAM. The
3326 area is used at an early stage (ROM part) if the environment
3327 is configured to reside in the SPI EEPROM: We need a 520 byte
3328 scratch DPRAM area. It is used between the two initialization
3329 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems
3330 to be a good choice since it makes it far enough from the
3331 start of the data area as well as from the stack pointer.
3333 Please note that the environment is read-only until the monitor
3334 has been relocated to RAM and a RAM copy of the environment has been
3335 created; also, when using EEPROM you will have to use getenv_f()
3336 until then to read environment variables.
3338 The environment is protected by a CRC32 checksum. Before the monitor
3339 is relocated into RAM, as a result of a bad CRC you will be working
3340 with the compiled-in default environment - *silently*!!! [This is
3341 necessary, because the first environment variable we need is the
3342 "baudrate" setting for the console - if we have a bad CRC, we don't
3343 have any device yet where we could complain.]
3345 Note: once the monitor has been relocated, then it will complain if
3346 the default environment is used; a new CRC is computed as soon as you
3347 use the "saveenv" command to store a valid environment.
3349 - CONFIG_SYS_FAULT_ECHO_LINK_DOWN:
3350 Echo the inverted Ethernet link state to the fault LED.
3352 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR
3353 also needs to be defined.
3355 - CONFIG_SYS_FAULT_MII_ADDR:
3356 MII address of the PHY to check for the Ethernet link state.
3358 - CONFIG_NS16550_MIN_FUNCTIONS:
3359 Define this if you desire to only have use of the NS16550_init
3360 and NS16550_putc functions for the serial driver located at
3361 drivers/serial/ns16550.c. This option is useful for saving
3362 space for already greatly restricted images, including but not
3363 limited to NAND_SPL configurations.
3365 Low Level (hardware related) configuration options:
3366 ---------------------------------------------------
3368 - CONFIG_SYS_CACHELINE_SIZE:
3369 Cache Line Size of the CPU.
3371 - CONFIG_SYS_DEFAULT_IMMR:
3372 Default address of the IMMR after system reset.
3374 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU,
3375 and RPXsuper) to be able to adjust the position of
3376 the IMMR register after a reset.
3378 - CONFIG_SYS_CCSRBAR_DEFAULT:
3379 Default (power-on reset) physical address of CCSR on Freescale
3382 - CONFIG_SYS_CCSRBAR:
3383 Virtual address of CCSR. On a 32-bit build, this is typically
3384 the same value as CONFIG_SYS_CCSRBAR_DEFAULT.
3386 CONFIG_SYS_DEFAULT_IMMR must also be set to this value,
3387 for cross-platform code that uses that macro instead.
3389 - CONFIG_SYS_CCSRBAR_PHYS:
3390 Physical address of CCSR. CCSR can be relocated to a new
3391 physical address, if desired. In this case, this macro should
3392 be set to that address. Otherwise, it should be set to the
3393 same value as CONFIG_SYS_CCSRBAR_DEFAULT. For example, CCSR
3394 is typically relocated on 36-bit builds. It is recommended
3395 that this macro be defined via the _HIGH and _LOW macros:
3397 #define CONFIG_SYS_CCSRBAR_PHYS ((CONFIG_SYS_CCSRBAR_PHYS_HIGH
3398 * 1ull) << 32 | CONFIG_SYS_CCSRBAR_PHYS_LOW)
3400 - CONFIG_SYS_CCSRBAR_PHYS_HIGH:
3401 Bits 33-36 of CONFIG_SYS_CCSRBAR_PHYS. This value is typically
3402 either 0 (32-bit build) or 0xF (36-bit build). This macro is
3403 used in assembly code, so it must not contain typecasts or
3404 integer size suffixes (e.g. "ULL").
3406 - CONFIG_SYS_CCSRBAR_PHYS_LOW:
3407 Lower 32-bits of CONFIG_SYS_CCSRBAR_PHYS. This macro is
3408 used in assembly code, so it must not contain typecasts or
3409 integer size suffixes (e.g. "ULL").
3411 - CONFIG_SYS_CCSR_DO_NOT_RELOCATE:
3412 If this macro is defined, then CONFIG_SYS_CCSRBAR_PHYS will be
3413 forced to a value that ensures that CCSR is not relocated.
3415 - Floppy Disk Support:
3416 CONFIG_SYS_FDC_DRIVE_NUMBER
3418 the default drive number (default value 0)
3420 CONFIG_SYS_ISA_IO_STRIDE
3422 defines the spacing between FDC chipset registers
3425 CONFIG_SYS_ISA_IO_OFFSET
3427 defines the offset of register from address. It
3428 depends on which part of the data bus is connected to
3429 the FDC chipset. (default value 0)
3431 If CONFIG_SYS_ISA_IO_STRIDE CONFIG_SYS_ISA_IO_OFFSET and
3432 CONFIG_SYS_FDC_DRIVE_NUMBER are undefined, they take their
3435 if CONFIG_SYS_FDC_HW_INIT is defined, then the function
3436 fdc_hw_init() is called at the beginning of the FDC
3437 setup. fdc_hw_init() must be provided by the board
3438 source code. It is used to make hardware dependant
3442 Most IDE controllers were designed to be connected with PCI
3443 interface. Only few of them were designed for AHB interface.
3444 When software is doing ATA command and data transfer to
3445 IDE devices through IDE-AHB controller, some additional
3446 registers accessing to these kind of IDE-AHB controller
3449 - CONFIG_SYS_IMMR: Physical address of the Internal Memory.
3450 DO NOT CHANGE unless you know exactly what you're
3451 doing! (11-4) [MPC8xx/82xx systems only]
3453 - CONFIG_SYS_INIT_RAM_ADDR:
3455 Start address of memory area that can be used for
3456 initial data and stack; please note that this must be
3457 writable memory that is working WITHOUT special
3458 initialization, i. e. you CANNOT use normal RAM which
3459 will become available only after programming the
3460 memory controller and running certain initialization
3463 U-Boot uses the following memory types:
3464 - MPC8xx and MPC8260: IMMR (internal memory of the CPU)
3465 - MPC824X: data cache
3466 - PPC4xx: data cache
3468 - CONFIG_SYS_GBL_DATA_OFFSET:
3470 Offset of the initial data structure in the memory
3471 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually
3472 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial
3473 data is located at the end of the available space
3474 (sometimes written as (CONFIG_SYS_INIT_RAM_SIZE -
3475 CONFIG_SYS_INIT_DATA_SIZE), and the initial stack is just
3476 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR +
3477 CONFIG_SYS_GBL_DATA_OFFSET) downward.
3480 On the MPC824X (or other systems that use the data
3481 cache for initial memory) the address chosen for
3482 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must
3483 point to an otherwise UNUSED address space between
3484 the top of RAM and the start of the PCI space.
3486 - CONFIG_SYS_SIUMCR: SIU Module Configuration (11-6)
3488 - CONFIG_SYS_SYPCR: System Protection Control (11-9)
3490 - CONFIG_SYS_TBSCR: Time Base Status and Control (11-26)
3492 - CONFIG_SYS_PISCR: Periodic Interrupt Status and Control (11-31)
3494 - CONFIG_SYS_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30)
3496 - CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27)
3498 - CONFIG_SYS_OR_TIMING_SDRAM:
3501 - CONFIG_SYS_MAMR_PTA:
3502 periodic timer for refresh
3504 - CONFIG_SYS_DER: Debug Event Register (37-47)
3506 - FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM,
3507 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP,
3508 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM,
3509 CONFIG_SYS_BR1_PRELIM:
3510 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
3512 - SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
3513 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM,
3514 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM:
3515 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
3517 - CONFIG_SYS_MAMR_PTA, CONFIG_SYS_MPTPR_2BK_4K, CONFIG_SYS_MPTPR_1BK_4K, CONFIG_SYS_MPTPR_2BK_8K,
3518 CONFIG_SYS_MPTPR_1BK_8K, CONFIG_SYS_MAMR_8COL, CONFIG_SYS_MAMR_9COL:
3519 Machine Mode Register and Memory Periodic Timer
3520 Prescaler definitions (SDRAM timing)
3522 - CONFIG_SYS_I2C_UCODE_PATCH, CONFIG_SYS_I2C_DPMEM_OFFSET [0x1FC0]:
3523 enable I2C microcode relocation patch (MPC8xx);
3524 define relocation offset in DPRAM [DSP2]
3526 - CONFIG_SYS_SMC_UCODE_PATCH, CONFIG_SYS_SMC_DPMEM_OFFSET [0x1FC0]:
3527 enable SMC microcode relocation patch (MPC8xx);
3528 define relocation offset in DPRAM [SMC1]
3530 - CONFIG_SYS_SPI_UCODE_PATCH, CONFIG_SYS_SPI_DPMEM_OFFSET [0x1FC0]:
3531 enable SPI microcode relocation patch (MPC8xx);
3532 define relocation offset in DPRAM [SCC4]
3534 - CONFIG_SYS_USE_OSCCLK:
3535 Use OSCM clock mode on MBX8xx board. Be careful,
3536 wrong setting might damage your board. Read
3537 doc/README.MBX before setting this variable!
3539 - CONFIG_SYS_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only)
3540 Offset of the bootmode word in DPRAM used by post
3541 (Power On Self Tests). This definition overrides
3542 #define'd default value in commproc.h resp.
3545 - CONFIG_SYS_PCI_SLV_MEM_LOCAL, CONFIG_SYS_PCI_SLV_MEM_BUS, CONFIG_SYS_PICMR0_MASK_ATTRIB,
3546 CONFIG_SYS_PCI_MSTR0_LOCAL, CONFIG_SYS_PCIMSK0_MASK, CONFIG_SYS_PCI_MSTR1_LOCAL,
3547 CONFIG_SYS_PCIMSK1_MASK, CONFIG_SYS_PCI_MSTR_MEM_LOCAL, CONFIG_SYS_PCI_MSTR_MEM_BUS,
3548 CONFIG_SYS_CPU_PCI_MEM_START, CONFIG_SYS_PCI_MSTR_MEM_SIZE, CONFIG_SYS_POCMR0_MASK_ATTRIB,
3549 CONFIG_SYS_PCI_MSTR_MEMIO_LOCAL, CONFIG_SYS_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START,
3550 CONFIG_SYS_PCI_MSTR_MEMIO_SIZE, CONFIG_SYS_POCMR1_MASK_ATTRIB, CONFIG_SYS_PCI_MSTR_IO_LOCAL,
3551 CONFIG_SYS_PCI_MSTR_IO_BUS, CONFIG_SYS_CPU_PCI_IO_START, CONFIG_SYS_PCI_MSTR_IO_SIZE,
3552 CONFIG_SYS_POCMR2_MASK_ATTRIB: (MPC826x only)
3553 Overrides the default PCI memory map in arch/powerpc/cpu/mpc8260/pci.c if set.
3555 - CONFIG_PCI_DISABLE_PCIE:
3556 Disable PCI-Express on systems where it is supported but not
3559 - CONFIG_PCI_ENUM_ONLY
3560 Only scan through and get the devices on the busses.
3561 Don't do any setup work, presumably because someone or
3562 something has already done it, and we don't need to do it
3563 a second time. Useful for platforms that are pre-booted
3564 by coreboot or similar.
3567 Chip has SRIO or not
3570 Board has SRIO 1 port available
3573 Board has SRIO 2 port available
3575 - CONFIG_SYS_SRIOn_MEM_VIRT:
3576 Virtual Address of SRIO port 'n' memory region
3578 - CONFIG_SYS_SRIOn_MEM_PHYS:
3579 Physical Address of SRIO port 'n' memory region
3581 - CONFIG_SYS_SRIOn_MEM_SIZE:
3582 Size of SRIO port 'n' memory region
3584 - CONFIG_SYS_NDFC_16
3585 Defined to tell the NDFC that the NAND chip is using a
3588 - CONFIG_SYS_NDFC_EBC0_CFG
3589 Sets the EBC0_CFG register for the NDFC. If not defined
3590 a default value will be used.
3593 Get DDR timing information from an I2C EEPROM. Common
3594 with pluggable memory modules such as SODIMMs
3597 I2C address of the SPD EEPROM
3599 - CONFIG_SYS_SPD_BUS_NUM
3600 If SPD EEPROM is on an I2C bus other than the first
3601 one, specify here. Note that the value must resolve
3602 to something your driver can deal with.
3604 - CONFIG_SYS_DDR_RAW_TIMING
3605 Get DDR timing information from other than SPD. Common with
3606 soldered DDR chips onboard without SPD. DDR raw timing
3607 parameters are extracted from datasheet and hard-coded into
3608 header files or board specific files.
3610 - CONFIG_FSL_DDR_INTERACTIVE
3611 Enable interactive DDR debugging. See doc/README.fsl-ddr.
3613 - CONFIG_SYS_83XX_DDR_USES_CS0
3614 Only for 83xx systems. If specified, then DDR should
3615 be configured using CS0 and CS1 instead of CS2 and CS3.
3617 - CONFIG_ETHER_ON_FEC[12]
3618 Define to enable FEC[12] on a 8xx series processor.
3620 - CONFIG_FEC[12]_PHY
3621 Define to the hardcoded PHY address which corresponds
3622 to the given FEC; i. e.
3623 #define CONFIG_FEC1_PHY 4
3624 means that the PHY with address 4 is connected to FEC1
3626 When set to -1, means to probe for first available.
3628 - CONFIG_FEC[12]_PHY_NORXERR
3629 The PHY does not have a RXERR line (RMII only).
3630 (so program the FEC to ignore it).
3633 Enable RMII mode for all FECs.
3634 Note that this is a global option, we can't
3635 have one FEC in standard MII mode and another in RMII mode.
3637 - CONFIG_CRC32_VERIFY
3638 Add a verify option to the crc32 command.
3641 => crc32 -v <address> <count> <crc32>
3643 Where address/count indicate a memory area
3644 and crc32 is the correct crc32 which the
3648 Add the "loopw" memory command. This only takes effect if
3649 the memory commands are activated globally (CONFIG_CMD_MEM).
3652 Add the "mdc" and "mwc" memory commands. These are cyclic
3657 This command will print 4 bytes (10,11,12,13) each 500 ms.
3659 => mwc.l 100 12345678 10
3660 This command will write 12345678 to address 100 all 10 ms.
3662 This only takes effect if the memory commands are activated
3663 globally (CONFIG_CMD_MEM).
3665 - CONFIG_SKIP_LOWLEVEL_INIT
3666 [ARM, NDS32, MIPS only] If this variable is defined, then certain
3667 low level initializations (like setting up the memory
3668 controller) are omitted and/or U-Boot does not
3669 relocate itself into RAM.
3671 Normally this variable MUST NOT be defined. The only
3672 exception is when U-Boot is loaded (to RAM) by some
3673 other boot loader or by a debugger which performs
3674 these initializations itself.
3677 Modifies the behaviour of start.S when compiling a loader
3678 that is executed before the actual U-Boot. E.g. when
3679 compiling a NAND SPL.
3681 - CONFIG_USE_ARCH_MEMCPY
3682 CONFIG_USE_ARCH_MEMSET
3683 If these options are used a optimized version of memcpy/memset will
3684 be used if available. These functions may be faster under some
3685 conditions but may increase the binary size.
3687 - CONFIG_X86_NO_RESET_VECTOR
3688 If defined, the x86 reset vector code is excluded. You will need
3689 to do this when U-Boot is running from Coreboot.
3691 - CONFIG_X86_NO_REAL_MODE
3692 If defined, x86 real mode code is omitted. This assumes a
3693 32-bit environment where such code is not needed. You will
3694 need to do this when U-Boot is running from Coreboot.
3697 Freescale QE/FMAN Firmware Support:
3698 -----------------------------------
3700 The Freescale QUICCEngine (QE) and Frame Manager (FMAN) both support the
3701 loading of "firmware", which is encoded in the QE firmware binary format.
3702 This firmware often needs to be loaded during U-Boot booting, so macros
3703 are used to identify the storage device (NOR flash, SPI, etc) and the address
3706 - CONFIG_SYS_QE_FMAN_FW_ADDR
3707 The address in the storage device where the firmware is located. The
3708 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
3711 - CONFIG_SYS_QE_FMAN_FW_LENGTH
3712 The maximum possible size of the firmware. The firmware binary format
3713 has a field that specifies the actual size of the firmware, but it
3714 might not be possible to read any part of the firmware unless some
3715 local storage is allocated to hold the entire firmware first.
3717 - CONFIG_SYS_QE_FMAN_FW_IN_NOR
3718 Specifies that QE/FMAN firmware is located in NOR flash, mapped as
3719 normal addressable memory via the LBC. CONFIG_SYS_FMAN_FW_ADDR is the
3720 virtual address in NOR flash.
3722 - CONFIG_SYS_QE_FMAN_FW_IN_NAND
3723 Specifies that QE/FMAN firmware is located in NAND flash.
3724 CONFIG_SYS_FMAN_FW_ADDR is the offset within NAND flash.
3726 - CONFIG_SYS_QE_FMAN_FW_IN_MMC
3727 Specifies that QE/FMAN firmware is located on the primary SD/MMC
3728 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
3730 - CONFIG_SYS_QE_FMAN_FW_IN_SPIFLASH
3731 Specifies that QE/FMAN firmware is located on the primary SPI
3732 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
3734 - CONFIG_SYS_QE_FMAN_FW_IN_REMOTE
3735 Specifies that QE/FMAN firmware is located in the remote (master)
3736 memory space. CONFIG_SYS_FMAN_FW_ADDR is a virtual address which
3737 can be mapped from slave TLB->slave LAW->slave SRIO or PCIE outbound
3738 window->master inbound window->master LAW->the ucode address in
3739 master's memory space.
3741 Building the Software:
3742 ======================
3744 Building U-Boot has been tested in several native build environments
3745 and in many different cross environments. Of course we cannot support
3746 all possibly existing versions of cross development tools in all
3747 (potentially obsolete) versions. In case of tool chain problems we
3748 recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK)
3749 which is extensively used to build and test U-Boot.
3751 If you are not using a native environment, it is assumed that you
3752 have GNU cross compiling tools available in your path. In this case,
3753 you must set the environment variable CROSS_COMPILE in your shell.
3754 Note that no changes to the Makefile or any other source files are
3755 necessary. For example using the ELDK on a 4xx CPU, please enter:
3757 $ CROSS_COMPILE=ppc_4xx-
3758 $ export CROSS_COMPILE
3760 Note: If you wish to generate Windows versions of the utilities in
3761 the tools directory you can use the MinGW toolchain
3762 (http://www.mingw.org). Set your HOST tools to the MinGW
3763 toolchain and execute 'make tools'. For example:
3765 $ make HOSTCC=i586-mingw32msvc-gcc HOSTSTRIP=i586-mingw32msvc-strip tools
3767 Binaries such as tools/mkimage.exe will be created which can
3768 be executed on computers running Windows.
3770 U-Boot is intended to be simple to build. After installing the
3771 sources you must configure U-Boot for one specific board type. This
3776 where "NAME_config" is the name of one of the existing configu-
3777 rations; see boards.cfg for supported names.
3779 Note: for some board special configuration names may exist; check if
3780 additional information is available from the board vendor; for
3781 instance, the TQM823L systems are available without (standard)
3782 or with LCD support. You can select such additional "features"
3783 when choosing the configuration, i. e.
3786 - will configure for a plain TQM823L, i. e. no LCD support
3788 make TQM823L_LCD_config
3789 - will configure for a TQM823L with U-Boot console on LCD
3794 Finally, type "make all", and you should get some working U-Boot
3795 images ready for download to / installation on your system:
3797 - "u-boot.bin" is a raw binary image
3798 - "u-boot" is an image in ELF binary format
3799 - "u-boot.srec" is in Motorola S-Record format
3801 By default the build is performed locally and the objects are saved
3802 in the source directory. One of the two methods can be used to change
3803 this behavior and build U-Boot to some external directory:
3805 1. Add O= to the make command line invocations:
3807 make O=/tmp/build distclean
3808 make O=/tmp/build NAME_config
3809 make O=/tmp/build all
3811 2. Set environment variable BUILD_DIR to point to the desired location:
3813 export BUILD_DIR=/tmp/build
3818 Note that the command line "O=" setting overrides the BUILD_DIR environment
3822 Please be aware that the Makefiles assume you are using GNU make, so
3823 for instance on NetBSD you might need to use "gmake" instead of
3827 If the system board that you have is not listed, then you will need
3828 to port U-Boot to your hardware platform. To do this, follow these
3831 1. Add a new configuration option for your board to the toplevel
3832 "boards.cfg" file, using the existing entries as examples.
3833 Follow the instructions there to keep the boards in order.
3834 2. Create a new directory to hold your board specific code. Add any
3835 files you need. In your board directory, you will need at least
3836 the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds".
3837 3. Create a new configuration file "include/configs/<board>.h" for
3839 3. If you're porting U-Boot to a new CPU, then also create a new
3840 directory to hold your CPU specific code. Add any files you need.
3841 4. Run "make <board>_config" with your new name.
3842 5. Type "make", and you should get a working "u-boot.srec" file
3843 to be installed on your target system.
3844 6. Debug and solve any problems that might arise.
3845 [Of course, this last step is much harder than it sounds.]
3848 Testing of U-Boot Modifications, Ports to New Hardware, etc.:
3849 ==============================================================
3851 If you have modified U-Boot sources (for instance added a new board
3852 or support for new devices, a new CPU, etc.) you are expected to
3853 provide feedback to the other developers. The feedback normally takes
3854 the form of a "patch", i. e. a context diff against a certain (latest
3855 official or latest in the git repository) version of U-Boot sources.
3857 But before you submit such a patch, please verify that your modifi-
3858 cation did not break existing code. At least make sure that *ALL* of
3859 the supported boards compile WITHOUT ANY compiler warnings. To do so,
3860 just run the "MAKEALL" script, which will configure and build U-Boot
3861 for ALL supported system. Be warned, this will take a while. You can
3862 select which (cross) compiler to use by passing a `CROSS_COMPILE'
3863 environment variable to the script, i. e. to use the ELDK cross tools
3866 CROSS_COMPILE=ppc_8xx- MAKEALL
3868 or to build on a native PowerPC system you can type
3870 CROSS_COMPILE=' ' MAKEALL
3872 When using the MAKEALL script, the default behaviour is to build
3873 U-Boot in the source directory. This location can be changed by
3874 setting the BUILD_DIR environment variable. Also, for each target
3875 built, the MAKEALL script saves two log files (<target>.ERR and
3876 <target>.MAKEALL) in the <source dir>/LOG directory. This default
3877 location can be changed by setting the MAKEALL_LOGDIR environment
3878 variable. For example:
3880 export BUILD_DIR=/tmp/build
3881 export MAKEALL_LOGDIR=/tmp/log
3882 CROSS_COMPILE=ppc_8xx- MAKEALL
3884 With the above settings build objects are saved in the /tmp/build,
3885 log files are saved in the /tmp/log and the source tree remains clean
3886 during the whole build process.
3889 See also "U-Boot Porting Guide" below.
3892 Monitor Commands - Overview:
3893 ============================
3895 go - start application at address 'addr'
3896 run - run commands in an environment variable
3897 bootm - boot application image from memory
3898 bootp - boot image via network using BootP/TFTP protocol
3899 bootz - boot zImage from memory
3900 tftpboot- boot image via network using TFTP protocol
3901 and env variables "ipaddr" and "serverip"
3902 (and eventually "gatewayip")
3903 tftpput - upload a file via network using TFTP protocol
3904 rarpboot- boot image via network using RARP/TFTP protocol
3905 diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
3906 loads - load S-Record file over serial line
3907 loadb - load binary file over serial line (kermit mode)
3909 mm - memory modify (auto-incrementing)
3910 nm - memory modify (constant address)
3911 mw - memory write (fill)
3913 cmp - memory compare
3914 crc32 - checksum calculation
3915 i2c - I2C sub-system
3916 sspi - SPI utility commands
3917 base - print or set address offset
3918 printenv- print environment variables
3919 setenv - set environment variables
3920 saveenv - save environment variables to persistent storage
3921 protect - enable or disable FLASH write protection
3922 erase - erase FLASH memory
3923 flinfo - print FLASH memory information
3924 nand - NAND memory operations (see doc/README.nand)
3925 bdinfo - print Board Info structure
3926 iminfo - print header information for application image
3927 coninfo - print console devices and informations
3928 ide - IDE sub-system
3929 loop - infinite loop on address range
3930 loopw - infinite write loop on address range
3931 mtest - simple RAM test
3932 icache - enable or disable instruction cache
3933 dcache - enable or disable data cache
3934 reset - Perform RESET of the CPU
3935 echo - echo args to console
3936 version - print monitor version
3937 help - print online help
3938 ? - alias for 'help'
3941 Monitor Commands - Detailed Description:
3942 ========================================
3946 For now: just type "help <command>".
3949 Environment Variables:
3950 ======================
3952 U-Boot supports user configuration using Environment Variables which
3953 can be made persistent by saving to Flash memory.
3955 Environment Variables are set using "setenv", printed using
3956 "printenv", and saved to Flash using "saveenv". Using "setenv"
3957 without a value can be used to delete a variable from the
3958 environment. As long as you don't save the environment you are
3959 working with an in-memory copy. In case the Flash area containing the
3960 environment is erased by accident, a default environment is provided.
3962 Some configuration options can be set using Environment Variables.
3964 List of environment variables (most likely not complete):
3966 baudrate - see CONFIG_BAUDRATE
3968 bootdelay - see CONFIG_BOOTDELAY
3970 bootcmd - see CONFIG_BOOTCOMMAND
3972 bootargs - Boot arguments when booting an RTOS image
3974 bootfile - Name of the image to load with TFTP
3976 bootm_low - Memory range available for image processing in the bootm
3977 command can be restricted. This variable is given as
3978 a hexadecimal number and defines lowest address allowed
3979 for use by the bootm command. See also "bootm_size"
3980 environment variable. Address defined by "bootm_low" is
3981 also the base of the initial memory mapping for the Linux
3982 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ and
3985 bootm_mapsize - Size of the initial memory mapping for the Linux kernel.
3986 This variable is given as a hexadecimal number and it
3987 defines the size of the memory region starting at base
3988 address bootm_low that is accessible by the Linux kernel
3989 during early boot. If unset, CONFIG_SYS_BOOTMAPSZ is used
3990 as the default value if it is defined, and bootm_size is
3993 bootm_size - Memory range available for image processing in the bootm
3994 command can be restricted. This variable is given as
3995 a hexadecimal number and defines the size of the region
3996 allowed for use by the bootm command. See also "bootm_low"
3997 environment variable.
3999 updatefile - Location of the software update file on a TFTP server, used
4000 by the automatic software update feature. Please refer to
4001 documentation in doc/README.update for more details.
4003 autoload - if set to "no" (any string beginning with 'n'),
4004 "bootp" will just load perform a lookup of the
4005 configuration from the BOOTP server, but not try to
4006 load any image using TFTP
4008 autostart - if set to "yes", an image loaded using the "bootp",
4009 "rarpboot", "tftpboot" or "diskboot" commands will
4010 be automatically started (by internally calling
4013 If set to "no", a standalone image passed to the
4014 "bootm" command will be copied to the load address
4015 (and eventually uncompressed), but NOT be started.
4016 This can be used to load and uncompress arbitrary
4019 fdt_high - if set this restricts the maximum address that the
4020 flattened device tree will be copied into upon boot.
4021 For example, if you have a system with 1 GB memory
4022 at physical address 0x10000000, while Linux kernel
4023 only recognizes the first 704 MB as low memory, you
4024 may need to set fdt_high as 0x3C000000 to have the
4025 device tree blob be copied to the maximum address
4026 of the 704 MB low memory, so that Linux kernel can
4027 access it during the boot procedure.
4029 If this is set to the special value 0xFFFFFFFF then
4030 the fdt will not be copied at all on boot. For this
4031 to work it must reside in writable memory, have
4032 sufficient padding on the end of it for u-boot to
4033 add the information it needs into it, and the memory
4034 must be accessible by the kernel.
4036 fdtcontroladdr- if set this is the address of the control flattened
4037 device tree used by U-Boot when CONFIG_OF_CONTROL is
4040 i2cfast - (PPC405GP|PPC405EP only)
4041 if set to 'y' configures Linux I2C driver for fast
4042 mode (400kHZ). This environment variable is used in
4043 initialization code. So, for changes to be effective
4044 it must be saved and board must be reset.
4046 initrd_high - restrict positioning of initrd images:
4047 If this variable is not set, initrd images will be
4048 copied to the highest possible address in RAM; this
4049 is usually what you want since it allows for
4050 maximum initrd size. If for some reason you want to
4051 make sure that the initrd image is loaded below the
4052 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment
4053 variable to a value of "no" or "off" or "0".
4054 Alternatively, you can set it to a maximum upper
4055 address to use (U-Boot will still check that it
4056 does not overwrite the U-Boot stack and data).
4058 For instance, when you have a system with 16 MB
4059 RAM, and want to reserve 4 MB from use by Linux,
4060 you can do this by adding "mem=12M" to the value of
4061 the "bootargs" variable. However, now you must make
4062 sure that the initrd image is placed in the first
4063 12 MB as well - this can be done with
4065 setenv initrd_high 00c00000
4067 If you set initrd_high to 0xFFFFFFFF, this is an
4068 indication to U-Boot that all addresses are legal
4069 for the Linux kernel, including addresses in flash
4070 memory. In this case U-Boot will NOT COPY the
4071 ramdisk at all. This may be useful to reduce the
4072 boot time on your system, but requires that this
4073 feature is supported by your Linux kernel.
4075 ipaddr - IP address; needed for tftpboot command
4077 loadaddr - Default load address for commands like "bootp",
4078 "rarpboot", "tftpboot", "loadb" or "diskboot"
4080 loads_echo - see CONFIG_LOADS_ECHO
4082 serverip - TFTP server IP address; needed for tftpboot command
4084 bootretry - see CONFIG_BOOT_RETRY_TIME
4086 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
4088 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
4090 ethprime - controls which interface is used first.
4092 ethact - controls which interface is currently active.
4093 For example you can do the following
4095 => setenv ethact FEC
4096 => ping 192.168.0.1 # traffic sent on FEC
4097 => setenv ethact SCC
4098 => ping 10.0.0.1 # traffic sent on SCC
4100 ethrotate - When set to "no" U-Boot does not go through all
4101 available network interfaces.
4102 It just stays at the currently selected interface.
4104 netretry - When set to "no" each network operation will
4105 either succeed or fail without retrying.
4106 When set to "once" the network operation will
4107 fail when all the available network interfaces
4108 are tried once without success.
4109 Useful on scripts which control the retry operation
4112 npe_ucode - set load address for the NPE microcode
4114 tftpsrcport - If this is set, the value is used for TFTP's
4117 tftpdstport - If this is set, the value is used for TFTP's UDP
4118 destination port instead of the Well Know Port 69.
4120 tftpblocksize - Block size to use for TFTP transfers; if not set,
4121 we use the TFTP server's default block size
4123 tftptimeout - Retransmission timeout for TFTP packets (in milli-
4124 seconds, minimum value is 1000 = 1 second). Defines
4125 when a packet is considered to be lost so it has to
4126 be retransmitted. The default is 5000 = 5 seconds.
4127 Lowering this value may make downloads succeed
4128 faster in networks with high packet loss rates or
4129 with unreliable TFTP servers.
4131 vlan - When set to a value < 4095 the traffic over
4132 Ethernet is encapsulated/received over 802.1q
4135 The following image location variables contain the location of images
4136 used in booting. The "Image" column gives the role of the image and is
4137 not an environment variable name. The other columns are environment
4138 variable names. "File Name" gives the name of the file on a TFTP
4139 server, "RAM Address" gives the location in RAM the image will be
4140 loaded to, and "Flash Location" gives the image's address in NOR
4141 flash or offset in NAND flash.
4143 *Note* - these variables don't have to be defined for all boards, some
4144 boards currenlty use other variables for these purposes, and some
4145 boards use these variables for other purposes.
4147 Image File Name RAM Address Flash Location
4148 ----- --------- ----------- --------------
4149 u-boot u-boot u-boot_addr_r u-boot_addr
4150 Linux kernel bootfile kernel_addr_r kernel_addr
4151 device tree blob fdtfile fdt_addr_r fdt_addr
4152 ramdisk ramdiskfile ramdisk_addr_r ramdisk_addr
4154 The following environment variables may be used and automatically
4155 updated by the network boot commands ("bootp" and "rarpboot"),
4156 depending the information provided by your boot server:
4158 bootfile - see above
4159 dnsip - IP address of your Domain Name Server
4160 dnsip2 - IP address of your secondary Domain Name Server
4161 gatewayip - IP address of the Gateway (Router) to use
4162 hostname - Target hostname
4164 netmask - Subnet Mask
4165 rootpath - Pathname of the root filesystem on the NFS server
4166 serverip - see above
4169 There are two special Environment Variables:
4171 serial# - contains hardware identification information such
4172 as type string and/or serial number
4173 ethaddr - Ethernet address
4175 These variables can be set only once (usually during manufacturing of
4176 the board). U-Boot refuses to delete or overwrite these variables
4177 once they have been set once.
4180 Further special Environment Variables:
4182 ver - Contains the U-Boot version string as printed
4183 with the "version" command. This variable is
4184 readonly (see CONFIG_VERSION_VARIABLE).
4187 Please note that changes to some configuration parameters may take
4188 only effect after the next boot (yes, that's just like Windoze :-).
4191 Command Line Parsing:
4192 =====================
4194 There are two different command line parsers available with U-Boot:
4195 the old "simple" one, and the much more powerful "hush" shell:
4197 Old, simple command line parser:
4198 --------------------------------
4200 - supports environment variables (through setenv / saveenv commands)
4201 - several commands on one line, separated by ';'
4202 - variable substitution using "... ${name} ..." syntax
4203 - special characters ('$', ';') can be escaped by prefixing with '\',
4205 setenv bootcmd bootm \${address}
4206 - You can also escape text by enclosing in single apostrophes, for example:
4207 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
4212 - similar to Bourne shell, with control structures like
4213 if...then...else...fi, for...do...done; while...do...done,
4214 until...do...done, ...
4215 - supports environment ("global") variables (through setenv / saveenv
4216 commands) and local shell variables (through standard shell syntax
4217 "name=value"); only environment variables can be used with "run"
4223 (1) If a command line (or an environment variable executed by a "run"
4224 command) contains several commands separated by semicolon, and
4225 one of these commands fails, then the remaining commands will be
4228 (2) If you execute several variables with one call to run (i. e.
4229 calling run with a list of variables as arguments), any failing
4230 command will cause "run" to terminate, i. e. the remaining
4231 variables are not executed.
4233 Note for Redundant Ethernet Interfaces:
4234 =======================================
4236 Some boards come with redundant Ethernet interfaces; U-Boot supports
4237 such configurations and is capable of automatic selection of a
4238 "working" interface when needed. MAC assignment works as follows:
4240 Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
4241 MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
4242 "eth1addr" (=>eth1), "eth2addr", ...
4244 If the network interface stores some valid MAC address (for instance
4245 in SROM), this is used as default address if there is NO correspon-
4246 ding setting in the environment; if the corresponding environment
4247 variable is set, this overrides the settings in the card; that means:
4249 o If the SROM has a valid MAC address, and there is no address in the
4250 environment, the SROM's address is used.
4252 o If there is no valid address in the SROM, and a definition in the
4253 environment exists, then the value from the environment variable is
4256 o If both the SROM and the environment contain a MAC address, and
4257 both addresses are the same, this MAC address is used.
4259 o If both the SROM and the environment contain a MAC address, and the
4260 addresses differ, the value from the environment is used and a
4263 o If neither SROM nor the environment contain a MAC address, an error
4266 If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses
4267 will be programmed into hardware as part of the initialization process. This
4268 may be skipped by setting the appropriate 'ethmacskip' environment variable.
4269 The naming convention is as follows:
4270 "ethmacskip" (=>eth0), "eth1macskip" (=>eth1) etc.
4275 U-Boot is capable of booting (and performing other auxiliary operations on)
4276 images in two formats:
4278 New uImage format (FIT)
4279 -----------------------
4281 Flexible and powerful format based on Flattened Image Tree -- FIT (similar
4282 to Flattened Device Tree). It allows the use of images with multiple
4283 components (several kernels, ramdisks, etc.), with contents protected by
4284 SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory.
4290 Old image format is based on binary files which can be basically anything,
4291 preceded by a special header; see the definitions in include/image.h for
4292 details; basically, the header defines the following image properties:
4294 * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
4295 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
4296 LynxOS, pSOS, QNX, RTEMS, INTEGRITY;
4297 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS,
4299 * Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86,
4300 IA64, MIPS, NDS32, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
4301 Currently supported: ARM, AVR32, Intel x86, MIPS, NDS32, Nios II, PowerPC).
4302 * Compression Type (uncompressed, gzip, bzip2)
4308 The header is marked by a special Magic Number, and both the header
4309 and the data portions of the image are secured against corruption by
4316 Although U-Boot should support any OS or standalone application
4317 easily, the main focus has always been on Linux during the design of
4320 U-Boot includes many features that so far have been part of some
4321 special "boot loader" code within the Linux kernel. Also, any
4322 "initrd" images to be used are no longer part of one big Linux image;
4323 instead, kernel and "initrd" are separate images. This implementation
4324 serves several purposes:
4326 - the same features can be used for other OS or standalone
4327 applications (for instance: using compressed images to reduce the
4328 Flash memory footprint)
4330 - it becomes much easier to port new Linux kernel versions because
4331 lots of low-level, hardware dependent stuff are done by U-Boot
4333 - the same Linux kernel image can now be used with different "initrd"
4334 images; of course this also means that different kernel images can
4335 be run with the same "initrd". This makes testing easier (you don't
4336 have to build a new "zImage.initrd" Linux image when you just
4337 change a file in your "initrd"). Also, a field-upgrade of the
4338 software is easier now.
4344 Porting Linux to U-Boot based systems:
4345 ---------------------------------------
4347 U-Boot cannot save you from doing all the necessary modifications to
4348 configure the Linux device drivers for use with your target hardware
4349 (no, we don't intend to provide a full virtual machine interface to
4352 But now you can ignore ALL boot loader code (in arch/powerpc/mbxboot).
4354 Just make sure your machine specific header file (for instance
4355 include/asm-ppc/tqm8xx.h) includes the same definition of the Board
4356 Information structure as we define in include/asm-<arch>/u-boot.h,
4357 and make sure that your definition of IMAP_ADDR uses the same value
4358 as your U-Boot configuration in CONFIG_SYS_IMMR.
4361 Configuring the Linux kernel:
4362 -----------------------------
4364 No specific requirements for U-Boot. Make sure you have some root
4365 device (initial ramdisk, NFS) for your target system.
4368 Building a Linux Image:
4369 -----------------------
4371 With U-Boot, "normal" build targets like "zImage" or "bzImage" are
4372 not used. If you use recent kernel source, a new build target
4373 "uImage" will exist which automatically builds an image usable by
4374 U-Boot. Most older kernels also have support for a "pImage" target,
4375 which was introduced for our predecessor project PPCBoot and uses a
4376 100% compatible format.
4385 The "uImage" build target uses a special tool (in 'tools/mkimage') to
4386 encapsulate a compressed Linux kernel image with header information,
4387 CRC32 checksum etc. for use with U-Boot. This is what we are doing:
4389 * build a standard "vmlinux" kernel image (in ELF binary format):
4391 * convert the kernel into a raw binary image:
4393 ${CROSS_COMPILE}-objcopy -O binary \
4394 -R .note -R .comment \
4395 -S vmlinux linux.bin
4397 * compress the binary image:
4401 * package compressed binary image for U-Boot:
4403 mkimage -A ppc -O linux -T kernel -C gzip \
4404 -a 0 -e 0 -n "Linux Kernel Image" \
4405 -d linux.bin.gz uImage
4408 The "mkimage" tool can also be used to create ramdisk images for use
4409 with U-Boot, either separated from the Linux kernel image, or
4410 combined into one file. "mkimage" encapsulates the images with a 64
4411 byte header containing information about target architecture,
4412 operating system, image type, compression method, entry points, time
4413 stamp, CRC32 checksums, etc.
4415 "mkimage" can be called in two ways: to verify existing images and
4416 print the header information, or to build new images.
4418 In the first form (with "-l" option) mkimage lists the information
4419 contained in the header of an existing U-Boot image; this includes
4420 checksum verification:
4422 tools/mkimage -l image
4423 -l ==> list image header information
4425 The second form (with "-d" option) is used to build a U-Boot image
4426 from a "data file" which is used as image payload:
4428 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
4429 -n name -d data_file image
4430 -A ==> set architecture to 'arch'
4431 -O ==> set operating system to 'os'
4432 -T ==> set image type to 'type'
4433 -C ==> set compression type 'comp'
4434 -a ==> set load address to 'addr' (hex)
4435 -e ==> set entry point to 'ep' (hex)
4436 -n ==> set image name to 'name'
4437 -d ==> use image data from 'datafile'
4439 Right now, all Linux kernels for PowerPC systems use the same load
4440 address (0x00000000), but the entry point address depends on the
4443 - 2.2.x kernels have the entry point at 0x0000000C,
4444 - 2.3.x and later kernels have the entry point at 0x00000000.
4446 So a typical call to build a U-Boot image would read:
4448 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
4449 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
4450 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz \
4451 > examples/uImage.TQM850L
4452 Image Name: 2.4.4 kernel for TQM850L
4453 Created: Wed Jul 19 02:34:59 2000
4454 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4455 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
4456 Load Address: 0x00000000
4457 Entry Point: 0x00000000
4459 To verify the contents of the image (or check for corruption):
4461 -> tools/mkimage -l examples/uImage.TQM850L
4462 Image Name: 2.4.4 kernel for TQM850L
4463 Created: Wed Jul 19 02:34:59 2000
4464 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4465 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
4466 Load Address: 0x00000000
4467 Entry Point: 0x00000000
4469 NOTE: for embedded systems where boot time is critical you can trade
4470 speed for memory and install an UNCOMPRESSED image instead: this
4471 needs more space in Flash, but boots much faster since it does not
4472 need to be uncompressed:
4474 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz
4475 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
4476 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
4477 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux \
4478 > examples/uImage.TQM850L-uncompressed
4479 Image Name: 2.4.4 kernel for TQM850L
4480 Created: Wed Jul 19 02:34:59 2000
4481 Image Type: PowerPC Linux Kernel Image (uncompressed)
4482 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
4483 Load Address: 0x00000000
4484 Entry Point: 0x00000000
4487 Similar you can build U-Boot images from a 'ramdisk.image.gz' file
4488 when your kernel is intended to use an initial ramdisk:
4490 -> tools/mkimage -n 'Simple Ramdisk Image' \
4491 > -A ppc -O linux -T ramdisk -C gzip \
4492 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
4493 Image Name: Simple Ramdisk Image
4494 Created: Wed Jan 12 14:01:50 2000
4495 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
4496 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
4497 Load Address: 0x00000000
4498 Entry Point: 0x00000000
4501 Installing a Linux Image:
4502 -------------------------
4504 To downloading a U-Boot image over the serial (console) interface,
4505 you must convert the image to S-Record format:
4507 objcopy -I binary -O srec examples/image examples/image.srec
4509 The 'objcopy' does not understand the information in the U-Boot
4510 image header, so the resulting S-Record file will be relative to
4511 address 0x00000000. To load it to a given address, you need to
4512 specify the target address as 'offset' parameter with the 'loads'
4515 Example: install the image to address 0x40100000 (which on the
4516 TQM8xxL is in the first Flash bank):
4518 => erase 40100000 401FFFFF
4524 ## Ready for S-Record download ...
4525 ~>examples/image.srec
4526 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
4528 15989 15990 15991 15992
4529 [file transfer complete]
4531 ## Start Addr = 0x00000000
4534 You can check the success of the download using the 'iminfo' command;
4535 this includes a checksum verification so you can be sure no data
4536 corruption happened:
4540 ## Checking Image at 40100000 ...
4541 Image Name: 2.2.13 for initrd on TQM850L
4542 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4543 Data Size: 335725 Bytes = 327 kB = 0 MB
4544 Load Address: 00000000
4545 Entry Point: 0000000c
4546 Verifying Checksum ... OK
4552 The "bootm" command is used to boot an application that is stored in
4553 memory (RAM or Flash). In case of a Linux kernel image, the contents
4554 of the "bootargs" environment variable is passed to the kernel as
4555 parameters. You can check and modify this variable using the
4556 "printenv" and "setenv" commands:
4559 => printenv bootargs
4560 bootargs=root=/dev/ram
4562 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
4564 => printenv bootargs
4565 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
4568 ## Booting Linux kernel at 40020000 ...
4569 Image Name: 2.2.13 for NFS on TQM850L
4570 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4571 Data Size: 381681 Bytes = 372 kB = 0 MB
4572 Load Address: 00000000
4573 Entry Point: 0000000c
4574 Verifying Checksum ... OK
4575 Uncompressing Kernel Image ... OK
4576 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
4577 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
4578 time_init: decrementer frequency = 187500000/60
4579 Calibrating delay loop... 49.77 BogoMIPS
4580 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
4583 If you want to boot a Linux kernel with initial RAM disk, you pass
4584 the memory addresses of both the kernel and the initrd image (PPBCOOT
4585 format!) to the "bootm" command:
4587 => imi 40100000 40200000
4589 ## Checking Image at 40100000 ...
4590 Image Name: 2.2.13 for initrd on TQM850L
4591 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4592 Data Size: 335725 Bytes = 327 kB = 0 MB
4593 Load Address: 00000000
4594 Entry Point: 0000000c
4595 Verifying Checksum ... OK
4597 ## Checking Image at 40200000 ...
4598 Image Name: Simple Ramdisk Image
4599 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
4600 Data Size: 566530 Bytes = 553 kB = 0 MB
4601 Load Address: 00000000
4602 Entry Point: 00000000
4603 Verifying Checksum ... OK
4605 => bootm 40100000 40200000
4606 ## Booting Linux kernel at 40100000 ...
4607 Image Name: 2.2.13 for initrd on TQM850L
4608 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4609 Data Size: 335725 Bytes = 327 kB = 0 MB
4610 Load Address: 00000000
4611 Entry Point: 0000000c
4612 Verifying Checksum ... OK
4613 Uncompressing Kernel Image ... OK
4614 ## Loading RAMDisk Image at 40200000 ...
4615 Image Name: Simple Ramdisk Image
4616 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
4617 Data Size: 566530 Bytes = 553 kB = 0 MB
4618 Load Address: 00000000
4619 Entry Point: 00000000
4620 Verifying Checksum ... OK
4621 Loading Ramdisk ... OK
4622 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
4623 Boot arguments: root=/dev/ram
4624 time_init: decrementer frequency = 187500000/60
4625 Calibrating delay loop... 49.77 BogoMIPS
4627 RAMDISK: Compressed image found at block 0
4628 VFS: Mounted root (ext2 filesystem).
4632 Boot Linux and pass a flat device tree:
4635 First, U-Boot must be compiled with the appropriate defines. See the section
4636 titled "Linux Kernel Interface" above for a more in depth explanation. The
4637 following is an example of how to start a kernel and pass an updated
4643 oft=oftrees/mpc8540ads.dtb
4644 => tftp $oftaddr $oft
4645 Speed: 1000, full duplex
4647 TFTP from server 192.168.1.1; our IP address is 192.168.1.101
4648 Filename 'oftrees/mpc8540ads.dtb'.
4649 Load address: 0x300000
4652 Bytes transferred = 4106 (100a hex)
4653 => tftp $loadaddr $bootfile
4654 Speed: 1000, full duplex
4656 TFTP from server 192.168.1.1; our IP address is 192.168.1.2
4658 Load address: 0x200000
4659 Loading:############
4661 Bytes transferred = 1029407 (fb51f hex)
4666 => bootm $loadaddr - $oftaddr
4667 ## Booting image at 00200000 ...
4668 Image Name: Linux-2.6.17-dirty
4669 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4670 Data Size: 1029343 Bytes = 1005.2 kB
4671 Load Address: 00000000
4672 Entry Point: 00000000
4673 Verifying Checksum ... OK
4674 Uncompressing Kernel Image ... OK
4675 Booting using flat device tree at 0x300000
4676 Using MPC85xx ADS machine description
4677 Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb
4681 More About U-Boot Image Types:
4682 ------------------------------
4684 U-Boot supports the following image types:
4686 "Standalone Programs" are directly runnable in the environment
4687 provided by U-Boot; it is expected that (if they behave
4688 well) you can continue to work in U-Boot after return from
4689 the Standalone Program.
4690 "OS Kernel Images" are usually images of some Embedded OS which
4691 will take over control completely. Usually these programs
4692 will install their own set of exception handlers, device
4693 drivers, set up the MMU, etc. - this means, that you cannot
4694 expect to re-enter U-Boot except by resetting the CPU.
4695 "RAMDisk Images" are more or less just data blocks, and their
4696 parameters (address, size) are passed to an OS kernel that is
4698 "Multi-File Images" contain several images, typically an OS
4699 (Linux) kernel image and one or more data images like
4700 RAMDisks. This construct is useful for instance when you want
4701 to boot over the network using BOOTP etc., where the boot
4702 server provides just a single image file, but you want to get
4703 for instance an OS kernel and a RAMDisk image.
4705 "Multi-File Images" start with a list of image sizes, each
4706 image size (in bytes) specified by an "uint32_t" in network
4707 byte order. This list is terminated by an "(uint32_t)0".
4708 Immediately after the terminating 0 follow the images, one by
4709 one, all aligned on "uint32_t" boundaries (size rounded up to
4710 a multiple of 4 bytes).
4712 "Firmware Images" are binary images containing firmware (like
4713 U-Boot or FPGA images) which usually will be programmed to
4716 "Script files" are command sequences that will be executed by
4717 U-Boot's command interpreter; this feature is especially
4718 useful when you configure U-Boot to use a real shell (hush)
4719 as command interpreter.
4721 Booting the Linux zImage:
4722 -------------------------
4724 On some platforms, it's possible to boot Linux zImage. This is done
4725 using the "bootz" command. The syntax of "bootz" command is the same
4726 as the syntax of "bootm" command.
4728 Note, defining the CONFIG_SUPPORT_INITRD_RAW allows user to supply
4729 kernel with raw initrd images. The syntax is slightly different, the
4730 address of the initrd must be augmented by it's size, in the following
4731 format: "<initrd addres>:<initrd size>".
4737 One of the features of U-Boot is that you can dynamically load and
4738 run "standalone" applications, which can use some resources of
4739 U-Boot like console I/O functions or interrupt services.
4741 Two simple examples are included with the sources:
4746 'examples/hello_world.c' contains a small "Hello World" Demo
4747 application; it is automatically compiled when you build U-Boot.
4748 It's configured to run at address 0x00040004, so you can play with it
4752 ## Ready for S-Record download ...
4753 ~>examples/hello_world.srec
4754 1 2 3 4 5 6 7 8 9 10 11 ...
4755 [file transfer complete]
4757 ## Start Addr = 0x00040004
4759 => go 40004 Hello World! This is a test.
4760 ## Starting application at 0x00040004 ...
4771 Hit any key to exit ...
4773 ## Application terminated, rc = 0x0
4775 Another example, which demonstrates how to register a CPM interrupt
4776 handler with the U-Boot code, can be found in 'examples/timer.c'.
4777 Here, a CPM timer is set up to generate an interrupt every second.
4778 The interrupt service routine is trivial, just printing a '.'
4779 character, but this is just a demo program. The application can be
4780 controlled by the following keys:
4782 ? - print current values og the CPM Timer registers
4783 b - enable interrupts and start timer
4784 e - stop timer and disable interrupts
4785 q - quit application
4788 ## Ready for S-Record download ...
4789 ~>examples/timer.srec
4790 1 2 3 4 5 6 7 8 9 10 11 ...
4791 [file transfer complete]
4793 ## Start Addr = 0x00040004
4796 ## Starting application at 0x00040004 ...
4799 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
4802 [q, b, e, ?] Set interval 1000000 us
4805 [q, b, e, ?] ........
4806 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
4809 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
4812 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
4815 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
4817 [q, b, e, ?] ...Stopping timer
4819 [q, b, e, ?] ## Application terminated, rc = 0x0
4825 Over time, many people have reported problems when trying to use the
4826 "minicom" terminal emulation program for serial download. I (wd)
4827 consider minicom to be broken, and recommend not to use it. Under
4828 Unix, I recommend to use C-Kermit for general purpose use (and
4829 especially for kermit binary protocol download ("loadb" command), and
4830 use "cu" for S-Record download ("loads" command). See
4831 http://www.denx.de/wiki/view/DULG/SystemSetup#Section_4.3.
4832 for help with kermit.
4835 Nevertheless, if you absolutely want to use it try adding this
4836 configuration to your "File transfer protocols" section:
4838 Name Program Name U/D FullScr IO-Red. Multi
4839 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
4840 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
4846 Starting at version 0.9.2, U-Boot supports NetBSD both as host
4847 (build U-Boot) and target system (boots NetBSD/mpc8xx).
4849 Building requires a cross environment; it is known to work on
4850 NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
4851 need gmake since the Makefiles are not compatible with BSD make).
4852 Note that the cross-powerpc package does not install include files;
4853 attempting to build U-Boot will fail because <machine/ansi.h> is
4854 missing. This file has to be installed and patched manually:
4856 # cd /usr/pkg/cross/powerpc-netbsd/include
4858 # ln -s powerpc machine
4859 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
4860 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
4862 Native builds *don't* work due to incompatibilities between native
4863 and U-Boot include files.
4865 Booting assumes that (the first part of) the image booted is a
4866 stage-2 loader which in turn loads and then invokes the kernel
4867 proper. Loader sources will eventually appear in the NetBSD source
4868 tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
4869 meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz
4872 Implementation Internals:
4873 =========================
4875 The following is not intended to be a complete description of every
4876 implementation detail. However, it should help to understand the
4877 inner workings of U-Boot and make it easier to port it to custom
4881 Initial Stack, Global Data:
4882 ---------------------------
4884 The implementation of U-Boot is complicated by the fact that U-Boot
4885 starts running out of ROM (flash memory), usually without access to
4886 system RAM (because the memory controller is not initialized yet).
4887 This means that we don't have writable Data or BSS segments, and BSS
4888 is not initialized as zero. To be able to get a C environment working
4889 at all, we have to allocate at least a minimal stack. Implementation
4890 options for this are defined and restricted by the CPU used: Some CPU
4891 models provide on-chip memory (like the IMMR area on MPC8xx and
4892 MPC826x processors), on others (parts of) the data cache can be
4893 locked as (mis-) used as memory, etc.
4895 Chris Hallinan posted a good summary of these issues to the
4896 U-Boot mailing list:
4898 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
4899 From: "Chris Hallinan" <clh@net1plus.com>
4900 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
4903 Correct me if I'm wrong, folks, but the way I understand it
4904 is this: Using DCACHE as initial RAM for Stack, etc, does not
4905 require any physical RAM backing up the cache. The cleverness
4906 is that the cache is being used as a temporary supply of
4907 necessary storage before the SDRAM controller is setup. It's
4908 beyond the scope of this list to explain the details, but you
4909 can see how this works by studying the cache architecture and
4910 operation in the architecture and processor-specific manuals.
4912 OCM is On Chip Memory, which I believe the 405GP has 4K. It
4913 is another option for the system designer to use as an
4914 initial stack/RAM area prior to SDRAM being available. Either
4915 option should work for you. Using CS 4 should be fine if your
4916 board designers haven't used it for something that would
4917 cause you grief during the initial boot! It is frequently not
4920 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere
4921 with your processor/board/system design. The default value
4922 you will find in any recent u-boot distribution in
4923 walnut.h should work for you. I'd set it to a value larger
4924 than your SDRAM module. If you have a 64MB SDRAM module, set
4925 it above 400_0000. Just make sure your board has no resources
4926 that are supposed to respond to that address! That code in
4927 start.S has been around a while and should work as is when
4928 you get the config right.
4933 It is essential to remember this, since it has some impact on the C
4934 code for the initialization procedures:
4936 * Initialized global data (data segment) is read-only. Do not attempt
4939 * Do not use any uninitialized global data (or implicitely initialized
4940 as zero data - BSS segment) at all - this is undefined, initiali-
4941 zation is performed later (when relocating to RAM).
4943 * Stack space is very limited. Avoid big data buffers or things like
4946 Having only the stack as writable memory limits means we cannot use
4947 normal global data to share information beween the code. But it
4948 turned out that the implementation of U-Boot can be greatly
4949 simplified by making a global data structure (gd_t) available to all
4950 functions. We could pass a pointer to this data as argument to _all_
4951 functions, but this would bloat the code. Instead we use a feature of
4952 the GCC compiler (Global Register Variables) to share the data: we
4953 place a pointer (gd) to the global data into a register which we
4954 reserve for this purpose.
4956 When choosing a register for such a purpose we are restricted by the
4957 relevant (E)ABI specifications for the current architecture, and by
4958 GCC's implementation.
4960 For PowerPC, the following registers have specific use:
4962 R2: reserved for system use
4963 R3-R4: parameter passing and return values
4964 R5-R10: parameter passing
4965 R13: small data area pointer
4969 (U-Boot also uses R12 as internal GOT pointer. r12
4970 is a volatile register so r12 needs to be reset when
4971 going back and forth between asm and C)
4973 ==> U-Boot will use R2 to hold a pointer to the global data
4975 Note: on PPC, we could use a static initializer (since the
4976 address of the global data structure is known at compile time),
4977 but it turned out that reserving a register results in somewhat
4978 smaller code - although the code savings are not that big (on
4979 average for all boards 752 bytes for the whole U-Boot image,
4980 624 text + 127 data).
4982 On Blackfin, the normal C ABI (except for P3) is followed as documented here:
4983 http://docs.blackfin.uclinux.org/doku.php?id=application_binary_interface
4985 ==> U-Boot will use P3 to hold a pointer to the global data
4987 On ARM, the following registers are used:
4989 R0: function argument word/integer result
4990 R1-R3: function argument word
4992 R10: stack limit (used only if stack checking if enabled)
4993 R11: argument (frame) pointer
4994 R12: temporary workspace
4997 R15: program counter
4999 ==> U-Boot will use R8 to hold a pointer to the global data
5001 On Nios II, the ABI is documented here:
5002 http://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf
5004 ==> U-Boot will use gp to hold a pointer to the global data
5006 Note: on Nios II, we give "-G0" option to gcc and don't use gp
5007 to access small data sections, so gp is free.
5009 On NDS32, the following registers are used:
5011 R0-R1: argument/return
5013 R15: temporary register for assembler
5014 R16: trampoline register
5015 R28: frame pointer (FP)
5016 R29: global pointer (GP)
5017 R30: link register (LP)
5018 R31: stack pointer (SP)
5019 PC: program counter (PC)
5021 ==> U-Boot will use R10 to hold a pointer to the global data
5023 NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope,
5024 or current versions of GCC may "optimize" the code too much.
5029 U-Boot runs in system state and uses physical addresses, i.e. the
5030 MMU is not used either for address mapping nor for memory protection.
5032 The available memory is mapped to fixed addresses using the memory
5033 controller. In this process, a contiguous block is formed for each
5034 memory type (Flash, SDRAM, SRAM), even when it consists of several
5035 physical memory banks.
5037 U-Boot is installed in the first 128 kB of the first Flash bank (on
5038 TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
5039 booting and sizing and initializing DRAM, the code relocates itself
5040 to the upper end of DRAM. Immediately below the U-Boot code some
5041 memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN
5042 configuration setting]. Below that, a structure with global Board
5043 Info data is placed, followed by the stack (growing downward).
5045 Additionally, some exception handler code is copied to the low 8 kB
5046 of DRAM (0x00000000 ... 0x00001FFF).
5048 So a typical memory configuration with 16 MB of DRAM could look like
5051 0x0000 0000 Exception Vector code
5054 0x0000 2000 Free for Application Use
5060 0x00FB FF20 Monitor Stack (Growing downward)
5061 0x00FB FFAC Board Info Data and permanent copy of global data
5062 0x00FC 0000 Malloc Arena
5065 0x00FE 0000 RAM Copy of Monitor Code
5066 ... eventually: LCD or video framebuffer
5067 ... eventually: pRAM (Protected RAM - unchanged by reset)
5068 0x00FF FFFF [End of RAM]
5071 System Initialization:
5072 ----------------------
5074 In the reset configuration, U-Boot starts at the reset entry point
5075 (on most PowerPC systems at address 0x00000100). Because of the reset
5076 configuration for CS0# this is a mirror of the onboard Flash memory.
5077 To be able to re-map memory U-Boot then jumps to its link address.
5078 To be able to implement the initialization code in C, a (small!)
5079 initial stack is set up in the internal Dual Ported RAM (in case CPUs
5080 which provide such a feature like MPC8xx or MPC8260), or in a locked
5081 part of the data cache. After that, U-Boot initializes the CPU core,
5082 the caches and the SIU.
5084 Next, all (potentially) available memory banks are mapped using a
5085 preliminary mapping. For example, we put them on 512 MB boundaries
5086 (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
5087 on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
5088 programmed for SDRAM access. Using the temporary configuration, a
5089 simple memory test is run that determines the size of the SDRAM
5092 When there is more than one SDRAM bank, and the banks are of
5093 different size, the largest is mapped first. For equal size, the first
5094 bank (CS2#) is mapped first. The first mapping is always for address
5095 0x00000000, with any additional banks following immediately to create
5096 contiguous memory starting from 0.
5098 Then, the monitor installs itself at the upper end of the SDRAM area
5099 and allocates memory for use by malloc() and for the global Board
5100 Info data; also, the exception vector code is copied to the low RAM
5101 pages, and the final stack is set up.
5103 Only after this relocation will you have a "normal" C environment;
5104 until that you are restricted in several ways, mostly because you are
5105 running from ROM, and because the code will have to be relocated to a
5109 U-Boot Porting Guide:
5110 ----------------------
5112 [Based on messages by Jerry Van Baren in the U-Boot-Users mailing
5116 int main(int argc, char *argv[])
5118 sighandler_t no_more_time;
5120 signal(SIGALRM, no_more_time);
5121 alarm(PROJECT_DEADLINE - toSec (3 * WEEK));
5123 if (available_money > available_manpower) {
5124 Pay consultant to port U-Boot;
5128 Download latest U-Boot source;
5130 Subscribe to u-boot mailing list;
5133 email("Hi, I am new to U-Boot, how do I get started?");
5136 Read the README file in the top level directory;
5137 Read http://www.denx.de/twiki/bin/view/DULG/Manual;
5138 Read applicable doc/*.README;
5139 Read the source, Luke;
5140 /* find . -name "*.[chS]" | xargs grep -i <keyword> */
5143 if (available_money > toLocalCurrency ($2500))
5146 Add a lot of aggravation and time;
5148 if (a similar board exists) { /* hopefully... */
5149 cp -a board/<similar> board/<myboard>
5150 cp include/configs/<similar>.h include/configs/<myboard>.h
5152 Create your own board support subdirectory;
5153 Create your own board include/configs/<myboard>.h file;
5155 Edit new board/<myboard> files
5156 Edit new include/configs/<myboard>.h
5161 Add / modify source code;
5165 email("Hi, I am having problems...");
5167 Send patch file to the U-Boot email list;
5168 if (reasonable critiques)
5169 Incorporate improvements from email list code review;
5171 Defend code as written;
5177 void no_more_time (int sig)
5186 All contributions to U-Boot should conform to the Linux kernel
5187 coding style; see the file "Documentation/CodingStyle" and the script
5188 "scripts/Lindent" in your Linux kernel source directory.
5190 Source files originating from a different project (for example the
5191 MTD subsystem) are generally exempt from these guidelines and are not
5192 reformated to ease subsequent migration to newer versions of those
5195 Please note that U-Boot is implemented in C (and to some small parts in
5196 Assembler); no C++ is used, so please do not use C++ style comments (//)
5199 Please also stick to the following formatting rules:
5200 - remove any trailing white space
5201 - use TAB characters for indentation and vertical alignment, not spaces
5202 - make sure NOT to use DOS '\r\n' line feeds
5203 - do not add more than 2 consecutive empty lines to source files
5204 - do not add trailing empty lines to source files
5206 Submissions which do not conform to the standards may be returned
5207 with a request to reformat the changes.
5213 Since the number of patches for U-Boot is growing, we need to
5214 establish some rules. Submissions which do not conform to these rules
5215 may be rejected, even when they contain important and valuable stuff.
5217 Please see http://www.denx.de/wiki/U-Boot/Patches for details.
5219 Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>;
5220 see http://lists.denx.de/mailman/listinfo/u-boot
5222 When you send a patch, please include the following information with
5225 * For bug fixes: a description of the bug and how your patch fixes
5226 this bug. Please try to include a way of demonstrating that the
5227 patch actually fixes something.
5229 * For new features: a description of the feature and your
5232 * A CHANGELOG entry as plaintext (separate from the patch)
5234 * For major contributions, your entry to the CREDITS file
5236 * When you add support for a new board, don't forget to add this
5237 board to the MAINTAINERS file, too.
5239 * If your patch adds new configuration options, don't forget to
5240 document these in the README file.
5242 * The patch itself. If you are using git (which is *strongly*
5243 recommended) you can easily generate the patch using the
5244 "git format-patch". If you then use "git send-email" to send it to
5245 the U-Boot mailing list, you will avoid most of the common problems
5246 with some other mail clients.
5248 If you cannot use git, use "diff -purN OLD NEW". If your version of
5249 diff does not support these options, then get the latest version of
5252 The current directory when running this command shall be the parent
5253 directory of the U-Boot source tree (i. e. please make sure that
5254 your patch includes sufficient directory information for the
5257 We prefer patches as plain text. MIME attachments are discouraged,
5258 and compressed attachments must not be used.
5260 * If one logical set of modifications affects or creates several
5261 files, all these changes shall be submitted in a SINGLE patch file.
5263 * Changesets that contain different, unrelated modifications shall be
5264 submitted as SEPARATE patches, one patch per changeset.
5269 * Before sending the patch, run the MAKEALL script on your patched
5270 source tree and make sure that no errors or warnings are reported
5271 for any of the boards.
5273 * Keep your modifications to the necessary minimum: A patch
5274 containing several unrelated changes or arbitrary reformats will be
5275 returned with a request to re-formatting / split it.
5277 * If you modify existing code, make sure that your new code does not
5278 add to the memory footprint of the code ;-) Small is beautiful!
5279 When adding new features, these should compile conditionally only
5280 (using #ifdef), and the resulting code with the new feature
5281 disabled must not need more memory than the old code without your
5284 * Remember that there is a size limit of 100 kB per message on the
5285 u-boot mailing list. Bigger patches will be moderated. If they are
5286 reasonable and not too big, they will be acknowledged. But patches
5287 bigger than the size limit should be avoided.
projects / karo-tx-uboot.git / blob